1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH != "i386" 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 y 11 depends on !64BIT 12 select CLKSRC_I8253 13 select HAVE_UID16 14 15config X86_64 16 def_bool y 17 depends on 64BIT 18 select X86_DEV_DMA_OPS 19 select ARCH_USE_CMPXCHG_LOCKREF 20 21### Arch settings 22config X86 23 def_bool y 24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 25 select HAVE_AOUT if X86_32 26 select HAVE_UNSTABLE_SCHED_CLOCK 27 select ARCH_SUPPORTS_NUMA_BALANCING 28 select ARCH_WANTS_PROT_NUMA_PROT_NONE 29 select HAVE_IDE 30 select HAVE_OPROFILE 31 select HAVE_PCSPKR_PLATFORM 32 select HAVE_PERF_EVENTS 33 select HAVE_IOREMAP_PROT 34 select HAVE_KPROBES 35 select HAVE_MEMBLOCK 36 select HAVE_MEMBLOCK_NODE_MAP 37 select ARCH_DISCARD_MEMBLOCK 38 select ARCH_WANT_OPTIONAL_GPIOLIB 39 select ARCH_WANT_FRAME_POINTERS 40 select HAVE_DMA_ATTRS 41 select HAVE_DMA_CONTIGUOUS if !SWIOTLB 42 select HAVE_KRETPROBES 43 select HAVE_OPTPROBES 44 select HAVE_KPROBES_ON_FTRACE 45 select HAVE_FTRACE_MCOUNT_RECORD 46 select HAVE_FENTRY if X86_64 47 select HAVE_C_RECORDMCOUNT 48 select HAVE_DYNAMIC_FTRACE 49 select HAVE_DYNAMIC_FTRACE_WITH_REGS 50 select HAVE_FUNCTION_TRACER 51 select HAVE_FUNCTION_GRAPH_TRACER 52 select HAVE_FUNCTION_GRAPH_FP_TEST 53 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 54 select HAVE_SYSCALL_TRACEPOINTS 55 select SYSCTL_EXCEPTION_TRACE 56 select HAVE_KVM 57 select HAVE_ARCH_KGDB 58 select HAVE_ARCH_TRACEHOOK 59 select HAVE_GENERIC_DMA_COHERENT if X86_32 60 select HAVE_EFFICIENT_UNALIGNED_ACCESS 61 select USER_STACKTRACE_SUPPORT 62 select HAVE_REGS_AND_STACK_ACCESS_API 63 select HAVE_DMA_API_DEBUG 64 select HAVE_KERNEL_GZIP 65 select HAVE_KERNEL_BZIP2 66 select HAVE_KERNEL_LZMA 67 select HAVE_KERNEL_XZ 68 select HAVE_KERNEL_LZO 69 select HAVE_KERNEL_LZ4 70 select HAVE_HW_BREAKPOINT 71 select HAVE_MIXED_BREAKPOINTS_REGS 72 select PERF_EVENTS 73 select HAVE_PERF_EVENTS_NMI 74 select HAVE_PERF_REGS 75 select HAVE_PERF_USER_STACK_DUMP 76 select HAVE_DEBUG_KMEMLEAK 77 select ANON_INODES 78 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 79 select HAVE_CMPXCHG_LOCAL 80 select HAVE_CMPXCHG_DOUBLE 81 select HAVE_ARCH_KMEMCHECK 82 select HAVE_USER_RETURN_NOTIFIER 83 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 84 select HAVE_ARCH_JUMP_LABEL 85 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 86 select SPARSE_IRQ 87 select GENERIC_FIND_FIRST_BIT 88 select GENERIC_IRQ_PROBE 89 select GENERIC_PENDING_IRQ if SMP 90 select GENERIC_IRQ_SHOW 91 select GENERIC_CLOCKEVENTS_MIN_ADJUST 92 select IRQ_FORCED_THREADING 93 select USE_GENERIC_SMP_HELPERS if SMP 94 select HAVE_BPF_JIT if X86_64 95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 96 select CLKEVT_I8253 97 select ARCH_HAVE_NMI_SAFE_CMPXCHG 98 select GENERIC_IOMAP 99 select DCACHE_WORD_ACCESS 100 select GENERIC_SMP_IDLE_THREAD 101 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 102 select HAVE_ARCH_SECCOMP_FILTER 103 select BUILDTIME_EXTABLE_SORT 104 select GENERIC_CMOS_UPDATE 105 select HAVE_ARCH_SOFT_DIRTY 106 select CLOCKSOURCE_WATCHDOG 107 select GENERIC_CLOCKEVENTS 108 select ARCH_CLOCKSOURCE_DATA if X86_64 109 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 110 select GENERIC_TIME_VSYSCALL if X86_64 111 select KTIME_SCALAR if X86_32 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select HAVE_CONTEXT_TRACKING if X86_64 115 select HAVE_IRQ_TIME_ACCOUNTING 116 select VIRT_TO_BUS 117 select MODULES_USE_ELF_REL if X86_32 118 select MODULES_USE_ELF_RELA if X86_64 119 select CLONE_BACKWARDS if X86_32 120 select ARCH_USE_BUILTIN_BSWAP 121 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 122 select OLD_SIGACTION if X86_32 123 select COMPAT_OLD_SIGACTION if IA32_EMULATION 124 select RTC_LIB 125 select HAVE_DEBUG_STACKOVERFLOW 126 127config INSTRUCTION_DECODER 128 def_bool y 129 depends on KPROBES || PERF_EVENTS || UPROBES 130 131config OUTPUT_FORMAT 132 string 133 default "elf32-i386" if X86_32 134 default "elf64-x86-64" if X86_64 135 136config ARCH_DEFCONFIG 137 string 138 default "arch/x86/configs/i386_defconfig" if X86_32 139 default "arch/x86/configs/x86_64_defconfig" if X86_64 140 141config LOCKDEP_SUPPORT 142 def_bool y 143 144config STACKTRACE_SUPPORT 145 def_bool y 146 147config HAVE_LATENCYTOP_SUPPORT 148 def_bool y 149 150config MMU 151 def_bool y 152 153config SBUS 154 bool 155 156config NEED_DMA_MAP_STATE 157 def_bool y 158 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 159 160config NEED_SG_DMA_LENGTH 161 def_bool y 162 163config GENERIC_ISA_DMA 164 def_bool y 165 depends on ISA_DMA_API 166 167config GENERIC_BUG 168 def_bool y 169 depends on BUG 170 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 171 172config GENERIC_BUG_RELATIVE_POINTERS 173 bool 174 175config GENERIC_HWEIGHT 176 def_bool y 177 178config ARCH_MAY_HAVE_PC_FDC 179 def_bool y 180 depends on ISA_DMA_API 181 182config RWSEM_XCHGADD_ALGORITHM 183 def_bool y 184 185config GENERIC_CALIBRATE_DELAY 186 def_bool y 187 188config ARCH_HAS_CPU_RELAX 189 def_bool y 190 191config ARCH_HAS_CACHE_LINE_SIZE 192 def_bool y 193 194config ARCH_HAS_CPU_AUTOPROBE 195 def_bool y 196 197config HAVE_SETUP_PER_CPU_AREA 198 def_bool y 199 200config NEED_PER_CPU_EMBED_FIRST_CHUNK 201 def_bool y 202 203config NEED_PER_CPU_PAGE_FIRST_CHUNK 204 def_bool y 205 206config ARCH_HIBERNATION_POSSIBLE 207 def_bool y 208 209config ARCH_SUSPEND_POSSIBLE 210 def_bool y 211 212config ARCH_WANT_HUGE_PMD_SHARE 213 def_bool y 214 215config ARCH_WANT_GENERAL_HUGETLB 216 def_bool y 217 218config ZONE_DMA32 219 bool 220 default X86_64 221 222config AUDIT_ARCH 223 bool 224 default X86_64 225 226config ARCH_SUPPORTS_OPTIMIZED_INLINING 227 def_bool y 228 229config ARCH_SUPPORTS_DEBUG_PAGEALLOC 230 def_bool y 231 232config HAVE_INTEL_TXT 233 def_bool y 234 depends on INTEL_IOMMU && ACPI 235 236config X86_32_SMP 237 def_bool y 238 depends on X86_32 && SMP 239 240config X86_64_SMP 241 def_bool y 242 depends on X86_64 && SMP 243 244config X86_HT 245 def_bool y 246 depends on SMP 247 248config X86_32_LAZY_GS 249 def_bool y 250 depends on X86_32 && !CC_STACKPROTECTOR 251 252config ARCH_HWEIGHT_CFLAGS 253 string 254 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 255 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_64 256 257config ARCH_CPU_PROBE_RELEASE 258 def_bool y 259 depends on HOTPLUG_CPU 260 261config ARCH_SUPPORTS_UPROBES 262 def_bool y 263 264source "init/Kconfig" 265source "kernel/Kconfig.freezer" 266 267menu "Processor type and features" 268 269config ZONE_DMA 270 bool "DMA memory allocation support" if EXPERT 271 default y 272 help 273 DMA memory allocation support allows devices with less than 32-bit 274 addressing to allocate within the first 16MB of address space. 275 Disable if no such devices will be used. 276 277 If unsure, say Y. 278 279config SMP 280 bool "Symmetric multi-processing support" 281 ---help--- 282 This enables support for systems with more than one CPU. If you have 283 a system with only one CPU, like most personal computers, say N. If 284 you have a system with more than one CPU, say Y. 285 286 If you say N here, the kernel will run on single and multiprocessor 287 machines, but will use only one CPU of a multiprocessor machine. If 288 you say Y here, the kernel will run on many, but not all, 289 singleprocessor machines. On a singleprocessor machine, the kernel 290 will run faster if you say N here. 291 292 Note that if you say Y here and choose architecture "586" or 293 "Pentium" under "Processor family", the kernel will not work on 486 294 architectures. Similarly, multiprocessor kernels for the "PPro" 295 architecture may not work on all Pentium based boards. 296 297 People using multiprocessor machines who say Y here should also say 298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 299 Management" code will be disabled if you say Y here. 300 301 See also <file:Documentation/x86/i386/IO-APIC.txt>, 302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 303 <http://www.tldp.org/docs.html#howto>. 304 305 If you don't know what to do here, say N. 306 307config X86_X2APIC 308 bool "Support x2apic" 309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 310 ---help--- 311 This enables x2apic support on CPUs that have this feature. 312 313 This allows 32-bit apic IDs (so it can support very large systems), 314 and accesses the local apic via MSRs not via mmio. 315 316 If you don't know what to do here, say N. 317 318config X86_MPPARSE 319 bool "Enable MPS table" if ACPI || SFI 320 default y 321 depends on X86_LOCAL_APIC 322 ---help--- 323 For old smp systems that do not have proper acpi support. Newer systems 324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 325 326config X86_BIGSMP 327 bool "Support for big SMP systems with more than 8 CPUs" 328 depends on X86_32 && SMP 329 ---help--- 330 This option is needed for the systems that have more than 8 CPUs 331 332config GOLDFISH 333 def_bool y 334 depends on X86_GOLDFISH 335 336if X86_32 337config X86_EXTENDED_PLATFORM 338 bool "Support for extended (non-PC) x86 platforms" 339 default y 340 ---help--- 341 If you disable this option then the kernel will only support 342 standard PC platforms. (which covers the vast majority of 343 systems out there.) 344 345 If you enable this option then you'll be able to select support 346 for the following (non-PC) 32 bit x86 platforms: 347 Goldfish (Android emulator) 348 AMD Elan 349 NUMAQ (IBM/Sequent) 350 RDC R-321x SoC 351 SGI 320/540 (Visual Workstation) 352 STA2X11-based (e.g. Northville) 353 Summit/EXA (IBM x440) 354 Unisys ES7000 IA32 series 355 Moorestown MID devices 356 357 If you have one of these systems, or if you want to build a 358 generic distribution kernel, say Y here - otherwise say N. 359endif 360 361if X86_64 362config X86_EXTENDED_PLATFORM 363 bool "Support for extended (non-PC) x86 platforms" 364 default y 365 ---help--- 366 If you disable this option then the kernel will only support 367 standard PC platforms. (which covers the vast majority of 368 systems out there.) 369 370 If you enable this option then you'll be able to select support 371 for the following (non-PC) 64 bit x86 platforms: 372 Numascale NumaChip 373 ScaleMP vSMP 374 SGI Ultraviolet 375 376 If you have one of these systems, or if you want to build a 377 generic distribution kernel, say Y here - otherwise say N. 378endif 379# This is an alphabetically sorted list of 64 bit extended platforms 380# Please maintain the alphabetic order if and when there are additions 381config X86_NUMACHIP 382 bool "Numascale NumaChip" 383 depends on X86_64 384 depends on X86_EXTENDED_PLATFORM 385 depends on NUMA 386 depends on SMP 387 depends on X86_X2APIC 388 depends on PCI_MMCONFIG 389 ---help--- 390 Adds support for Numascale NumaChip large-SMP systems. Needed to 391 enable more than ~168 cores. 392 If you don't have one of these, you should say N here. 393 394config X86_VSMP 395 bool "ScaleMP vSMP" 396 select HYPERVISOR_GUEST 397 select PARAVIRT 398 depends on X86_64 && PCI 399 depends on X86_EXTENDED_PLATFORM 400 depends on SMP 401 ---help--- 402 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 403 supposed to run on these EM64T-based machines. Only choose this option 404 if you have one of these machines. 405 406config X86_UV 407 bool "SGI Ultraviolet" 408 depends on X86_64 409 depends on X86_EXTENDED_PLATFORM 410 depends on NUMA 411 depends on X86_X2APIC 412 ---help--- 413 This option is needed in order to support SGI Ultraviolet systems. 414 If you don't have one of these, you should say N here. 415 416# Following is an alphabetically sorted list of 32 bit extended platforms 417# Please maintain the alphabetic order if and when there are additions 418 419config X86_GOLDFISH 420 bool "Goldfish (Virtual Platform)" 421 depends on X86_32 422 depends on X86_EXTENDED_PLATFORM 423 ---help--- 424 Enable support for the Goldfish virtual platform used primarily 425 for Android development. Unless you are building for the Android 426 Goldfish emulator say N here. 427 428config X86_INTEL_CE 429 bool "CE4100 TV platform" 430 depends on PCI 431 depends on PCI_GODIRECT 432 depends on X86_32 433 depends on X86_EXTENDED_PLATFORM 434 select X86_REBOOTFIXUPS 435 select OF 436 select OF_EARLY_FLATTREE 437 select IRQ_DOMAIN 438 ---help--- 439 Select for the Intel CE media processor (CE4100) SOC. 440 This option compiles in support for the CE4100 SOC for settop 441 boxes and media devices. 442 443config X86_WANT_INTEL_MID 444 bool "Intel MID platform support" 445 depends on X86_32 446 depends on X86_EXTENDED_PLATFORM 447 ---help--- 448 Select to build a kernel capable of supporting Intel MID platform 449 systems which do not have the PCI legacy interfaces (Moorestown, 450 Medfield). If you are building for a PC class system say N here. 451 452if X86_WANT_INTEL_MID 453 454config X86_INTEL_MID 455 bool 456 457config X86_MDFLD 458 bool "Medfield MID platform" 459 depends on PCI 460 depends on PCI_GOANY 461 depends on X86_IO_APIC 462 select X86_INTEL_MID 463 select SFI 464 select DW_APB_TIMER 465 select APB_TIMER 466 select I2C 467 select SPI 468 select INTEL_SCU_IPC 469 select X86_PLATFORM_DEVICES 470 select MFD_INTEL_MSIC 471 ---help--- 472 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin 473 Internet Device(MID) platform. 474 Unlike standard x86 PCs, Medfield does not have many legacy devices 475 nor standard legacy replacement devices/features. e.g. Medfield does 476 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 477 478endif 479 480config X86_INTEL_LPSS 481 bool "Intel Low Power Subsystem Support" 482 depends on ACPI 483 select COMMON_CLK 484 select PINCTRL 485 ---help--- 486 Select to build support for Intel Low Power Subsystem such as 487 found on Intel Lynxpoint PCH. Selecting this option enables 488 things like clock tree (common clock framework) and pincontrol 489 which are needed by the LPSS peripheral drivers. 490 491config X86_RDC321X 492 bool "RDC R-321x SoC" 493 depends on X86_32 494 depends on X86_EXTENDED_PLATFORM 495 select M486 496 select X86_REBOOTFIXUPS 497 ---help--- 498 This option is needed for RDC R-321x system-on-chip, also known 499 as R-8610-(G). 500 If you don't have one of these chips, you should say N here. 501 502config X86_32_NON_STANDARD 503 bool "Support non-standard 32-bit SMP architectures" 504 depends on X86_32 && SMP 505 depends on X86_EXTENDED_PLATFORM 506 ---help--- 507 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, 508 STA2X11, default subarchitectures. It is intended for a generic 509 binary kernel. If you select them all, kernel will probe it 510 one by one and will fallback to default. 511 512# Alphabetically sorted list of Non standard 32 bit platforms 513 514config X86_NUMAQ 515 bool "NUMAQ (IBM/Sequent)" 516 depends on X86_32_NON_STANDARD 517 depends on PCI 518 select NUMA 519 select X86_MPPARSE 520 ---help--- 521 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 522 NUMA multiquad box. This changes the way that processors are 523 bootstrapped, and uses Clustered Logical APIC addressing mode instead 524 of Flat Logical. You will need a new lynxer.elf file to flash your 525 firmware with - send email to <Martin.Bligh@us.ibm.com>. 526 527config X86_SUPPORTS_MEMORY_FAILURE 528 def_bool y 529 # MCE code calls memory_failure(): 530 depends on X86_MCE 531 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 532 depends on !X86_NUMAQ 533 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 534 depends on X86_64 || !SPARSEMEM 535 select ARCH_SUPPORTS_MEMORY_FAILURE 536 537config X86_VISWS 538 bool "SGI 320/540 (Visual Workstation)" 539 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 540 depends on X86_32_NON_STANDARD 541 ---help--- 542 The SGI Visual Workstation series is an IA32-based workstation 543 based on SGI systems chips with some legacy PC hardware attached. 544 545 Say Y here to create a kernel to run on the SGI 320 or 540. 546 547 A kernel compiled for the Visual Workstation will run on general 548 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 549 550config STA2X11 551 bool "STA2X11 Companion Chip Support" 552 depends on X86_32_NON_STANDARD && PCI 553 select X86_DEV_DMA_OPS 554 select X86_DMA_REMAP 555 select SWIOTLB 556 select MFD_STA2X11 557 select ARCH_REQUIRE_GPIOLIB 558 default n 559 ---help--- 560 This adds support for boards based on the STA2X11 IO-Hub, 561 a.k.a. "ConneXt". The chip is used in place of the standard 562 PC chipset, so all "standard" peripherals are missing. If this 563 option is selected the kernel will still be able to boot on 564 standard PC machines. 565 566config X86_SUMMIT 567 bool "Summit/EXA (IBM x440)" 568 depends on X86_32_NON_STANDARD 569 ---help--- 570 This option is needed for IBM systems that use the Summit/EXA chipset. 571 In particular, it is needed for the x440. 572 573config X86_ES7000 574 bool "Unisys ES7000 IA32 series" 575 depends on X86_32_NON_STANDARD && X86_BIGSMP 576 ---help--- 577 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 578 supposed to run on an IA32-based Unisys ES7000 system. 579 580config X86_32_IRIS 581 tristate "Eurobraille/Iris poweroff module" 582 depends on X86_32 583 ---help--- 584 The Iris machines from EuroBraille do not have APM or ACPI support 585 to shut themselves down properly. A special I/O sequence is 586 needed to do so, which is what this module does at 587 kernel shutdown. 588 589 This is only for Iris machines from EuroBraille. 590 591 If unused, say N. 592 593config SCHED_OMIT_FRAME_POINTER 594 def_bool y 595 prompt "Single-depth WCHAN output" 596 depends on X86 597 ---help--- 598 Calculate simpler /proc/<PID>/wchan values. If this option 599 is disabled then wchan values will recurse back to the 600 caller function. This provides more accurate wchan values, 601 at the expense of slightly more scheduling overhead. 602 603 If in doubt, say "Y". 604 605menuconfig HYPERVISOR_GUEST 606 bool "Linux guest support" 607 ---help--- 608 Say Y here to enable options for running Linux under various hyper- 609 visors. This option enables basic hypervisor detection and platform 610 setup. 611 612 If you say N, all options in this submenu will be skipped and 613 disabled, and Linux guest support won't be built in. 614 615if HYPERVISOR_GUEST 616 617config PARAVIRT 618 bool "Enable paravirtualization code" 619 ---help--- 620 This changes the kernel so it can modify itself when it is run 621 under a hypervisor, potentially improving performance significantly 622 over full virtualization. However, when run without a hypervisor 623 the kernel is theoretically slower and slightly larger. 624 625config PARAVIRT_DEBUG 626 bool "paravirt-ops debugging" 627 depends on PARAVIRT && DEBUG_KERNEL 628 ---help--- 629 Enable to debug paravirt_ops internals. Specifically, BUG if 630 a paravirt_op is missing when it is called. 631 632config PARAVIRT_SPINLOCKS 633 bool "Paravirtualization layer for spinlocks" 634 depends on PARAVIRT && SMP 635 select UNINLINE_SPIN_UNLOCK 636 ---help--- 637 Paravirtualized spinlocks allow a pvops backend to replace the 638 spinlock implementation with something virtualization-friendly 639 (for example, block the virtual CPU rather than spinning). 640 641 Unfortunately the downside is an up to 5% performance hit on 642 native kernels, with various workloads. 643 644 If you are unsure how to answer this question, answer N. 645 646source "arch/x86/xen/Kconfig" 647 648config KVM_GUEST 649 bool "KVM Guest support (including kvmclock)" 650 depends on PARAVIRT 651 select PARAVIRT_CLOCK 652 default y 653 ---help--- 654 This option enables various optimizations for running under the KVM 655 hypervisor. It includes a paravirtualized clock, so that instead 656 of relying on a PIT (or probably other) emulation by the 657 underlying device model, the host provides the guest with 658 timing infrastructure such as time of day, and system time 659 660config KVM_DEBUG_FS 661 bool "Enable debug information for KVM Guests in debugfs" 662 depends on KVM_GUEST && DEBUG_FS 663 default n 664 ---help--- 665 This option enables collection of various statistics for KVM guest. 666 Statistics are displayed in debugfs filesystem. Enabling this option 667 may incur significant overhead. 668 669source "arch/x86/lguest/Kconfig" 670 671config PARAVIRT_TIME_ACCOUNTING 672 bool "Paravirtual steal time accounting" 673 depends on PARAVIRT 674 default n 675 ---help--- 676 Select this option to enable fine granularity task steal time 677 accounting. Time spent executing other tasks in parallel with 678 the current vCPU is discounted from the vCPU power. To account for 679 that, there can be a small performance impact. 680 681 If in doubt, say N here. 682 683config PARAVIRT_CLOCK 684 bool 685 686endif #HYPERVISOR_GUEST 687 688config NO_BOOTMEM 689 def_bool y 690 691config MEMTEST 692 bool "Memtest" 693 ---help--- 694 This option adds a kernel parameter 'memtest', which allows memtest 695 to be set. 696 memtest=0, mean disabled; -- default 697 memtest=1, mean do 1 test pattern; 698 ... 699 memtest=4, mean do 4 test patterns. 700 If you are unsure how to answer this question, answer N. 701 702config X86_SUMMIT_NUMA 703 def_bool y 704 depends on X86_32 && NUMA && X86_32_NON_STANDARD 705 706config X86_CYCLONE_TIMER 707 def_bool y 708 depends on X86_SUMMIT 709 710source "arch/x86/Kconfig.cpu" 711 712config HPET_TIMER 713 def_bool X86_64 714 prompt "HPET Timer Support" if X86_32 715 ---help--- 716 Use the IA-PC HPET (High Precision Event Timer) to manage 717 time in preference to the PIT and RTC, if a HPET is 718 present. 719 HPET is the next generation timer replacing legacy 8254s. 720 The HPET provides a stable time base on SMP 721 systems, unlike the TSC, but it is more expensive to access, 722 as it is off-chip. You can find the HPET spec at 723 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 724 725 You can safely choose Y here. However, HPET will only be 726 activated if the platform and the BIOS support this feature. 727 Otherwise the 8254 will be used for timing services. 728 729 Choose N to continue using the legacy 8254 timer. 730 731config HPET_EMULATE_RTC 732 def_bool y 733 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 734 735config APB_TIMER 736 def_bool y if X86_INTEL_MID 737 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 738 select DW_APB_TIMER 739 depends on X86_INTEL_MID && SFI 740 help 741 APB timer is the replacement for 8254, HPET on X86 MID platforms. 742 The APBT provides a stable time base on SMP 743 systems, unlike the TSC, but it is more expensive to access, 744 as it is off-chip. APB timers are always running regardless of CPU 745 C states, they are used as per CPU clockevent device when possible. 746 747# Mark as expert because too many people got it wrong. 748# The code disables itself when not needed. 749config DMI 750 default y 751 bool "Enable DMI scanning" if EXPERT 752 ---help--- 753 Enabled scanning of DMI to identify machine quirks. Say Y 754 here unless you have verified that your setup is not 755 affected by entries in the DMI blacklist. Required by PNP 756 BIOS code. 757 758config GART_IOMMU 759 bool "GART IOMMU support" if EXPERT 760 default y 761 select SWIOTLB 762 depends on X86_64 && PCI && AMD_NB 763 ---help--- 764 Support for full DMA access of devices with 32bit memory access only 765 on systems with more than 3GB. This is usually needed for USB, 766 sound, many IDE/SATA chipsets and some other devices. 767 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 768 based hardware IOMMU and a software bounce buffer based IOMMU used 769 on Intel systems and as fallback. 770 The code is only active when needed (enough memory and limited 771 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 772 too. 773 774config CALGARY_IOMMU 775 bool "IBM Calgary IOMMU support" 776 select SWIOTLB 777 depends on X86_64 && PCI 778 ---help--- 779 Support for hardware IOMMUs in IBM's xSeries x366 and x460 780 systems. Needed to run systems with more than 3GB of memory 781 properly with 32-bit PCI devices that do not support DAC 782 (Double Address Cycle). Calgary also supports bus level 783 isolation, where all DMAs pass through the IOMMU. This 784 prevents them from going anywhere except their intended 785 destination. This catches hard-to-find kernel bugs and 786 mis-behaving drivers and devices that do not use the DMA-API 787 properly to set up their DMA buffers. The IOMMU can be 788 turned off at boot time with the iommu=off parameter. 789 Normally the kernel will make the right choice by itself. 790 If unsure, say Y. 791 792config CALGARY_IOMMU_ENABLED_BY_DEFAULT 793 def_bool y 794 prompt "Should Calgary be enabled by default?" 795 depends on CALGARY_IOMMU 796 ---help--- 797 Should Calgary be enabled by default? if you choose 'y', Calgary 798 will be used (if it exists). If you choose 'n', Calgary will not be 799 used even if it exists. If you choose 'n' and would like to use 800 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 801 If unsure, say Y. 802 803# need this always selected by IOMMU for the VIA workaround 804config SWIOTLB 805 def_bool y if X86_64 806 ---help--- 807 Support for software bounce buffers used on x86-64 systems 808 which don't have a hardware IOMMU. Using this PCI devices 809 which can only access 32-bits of memory can be used on systems 810 with more than 3 GB of memory. 811 If unsure, say Y. 812 813config IOMMU_HELPER 814 def_bool y 815 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 816 817config MAXSMP 818 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 819 depends on X86_64 && SMP && DEBUG_KERNEL 820 select CPUMASK_OFFSTACK 821 ---help--- 822 Enable maximum number of CPUS and NUMA Nodes for this architecture. 823 If unsure, say N. 824 825config NR_CPUS 826 int "Maximum number of CPUs" if SMP && !MAXSMP 827 range 2 8 if SMP && X86_32 && !X86_BIGSMP 828 range 2 512 if SMP && !MAXSMP 829 default "1" if !SMP 830 default "4096" if MAXSMP 831 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 832 default "8" if SMP 833 ---help--- 834 This allows you to specify the maximum number of CPUs which this 835 kernel will support. The maximum supported value is 512 and the 836 minimum value which makes sense is 2. 837 838 This is purely to save memory - each supported CPU adds 839 approximately eight kilobytes to the kernel image. 840 841config SCHED_SMT 842 bool "SMT (Hyperthreading) scheduler support" 843 depends on X86_HT 844 ---help--- 845 SMT scheduler support improves the CPU scheduler's decision making 846 when dealing with Intel Pentium 4 chips with HyperThreading at a 847 cost of slightly increased overhead in some places. If unsure say 848 N here. 849 850config SCHED_MC 851 def_bool y 852 prompt "Multi-core scheduler support" 853 depends on X86_HT 854 ---help--- 855 Multi-core scheduler support improves the CPU scheduler's decision 856 making when dealing with multi-core CPU chips at a cost of slightly 857 increased overhead in some places. If unsure say N here. 858 859source "kernel/Kconfig.preempt" 860 861config X86_UP_APIC 862 bool "Local APIC support on uniprocessors" 863 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 864 ---help--- 865 A local APIC (Advanced Programmable Interrupt Controller) is an 866 integrated interrupt controller in the CPU. If you have a single-CPU 867 system which has a processor with a local APIC, you can say Y here to 868 enable and use it. If you say Y here even though your machine doesn't 869 have a local APIC, then the kernel will still run with no slowdown at 870 all. The local APIC supports CPU-generated self-interrupts (timer, 871 performance counters), and the NMI watchdog which detects hard 872 lockups. 873 874config X86_UP_IOAPIC 875 bool "IO-APIC support on uniprocessors" 876 depends on X86_UP_APIC 877 ---help--- 878 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 879 SMP-capable replacement for PC-style interrupt controllers. Most 880 SMP systems and many recent uniprocessor systems have one. 881 882 If you have a single-CPU system with an IO-APIC, you can say Y here 883 to use it. If you say Y here even though your machine doesn't have 884 an IO-APIC, then the kernel will still run with no slowdown at all. 885 886config X86_LOCAL_APIC 887 def_bool y 888 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 889 890config X86_IO_APIC 891 def_bool y 892 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC 893 894config X86_VISWS_APIC 895 def_bool y 896 depends on X86_32 && X86_VISWS 897 898config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 899 bool "Reroute for broken boot IRQs" 900 depends on X86_IO_APIC 901 ---help--- 902 This option enables a workaround that fixes a source of 903 spurious interrupts. This is recommended when threaded 904 interrupt handling is used on systems where the generation of 905 superfluous "boot interrupts" cannot be disabled. 906 907 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 908 entry in the chipset's IO-APIC is masked (as, e.g. the RT 909 kernel does during interrupt handling). On chipsets where this 910 boot IRQ generation cannot be disabled, this workaround keeps 911 the original IRQ line masked so that only the equivalent "boot 912 IRQ" is delivered to the CPUs. The workaround also tells the 913 kernel to set up the IRQ handler on the boot IRQ line. In this 914 way only one interrupt is delivered to the kernel. Otherwise 915 the spurious second interrupt may cause the kernel to bring 916 down (vital) interrupt lines. 917 918 Only affects "broken" chipsets. Interrupt sharing may be 919 increased on these systems. 920 921config X86_MCE 922 bool "Machine Check / overheating reporting" 923 default y 924 ---help--- 925 Machine Check support allows the processor to notify the 926 kernel if it detects a problem (e.g. overheating, data corruption). 927 The action the kernel takes depends on the severity of the problem, 928 ranging from warning messages to halting the machine. 929 930config X86_MCE_INTEL 931 def_bool y 932 prompt "Intel MCE features" 933 depends on X86_MCE && X86_LOCAL_APIC 934 ---help--- 935 Additional support for intel specific MCE features such as 936 the thermal monitor. 937 938config X86_MCE_AMD 939 def_bool y 940 prompt "AMD MCE features" 941 depends on X86_MCE && X86_LOCAL_APIC 942 ---help--- 943 Additional support for AMD specific MCE features such as 944 the DRAM Error Threshold. 945 946config X86_ANCIENT_MCE 947 bool "Support for old Pentium 5 / WinChip machine checks" 948 depends on X86_32 && X86_MCE 949 ---help--- 950 Include support for machine check handling on old Pentium 5 or WinChip 951 systems. These typically need to be enabled explicitely on the command 952 line. 953 954config X86_MCE_THRESHOLD 955 depends on X86_MCE_AMD || X86_MCE_INTEL 956 def_bool y 957 958config X86_MCE_INJECT 959 depends on X86_MCE 960 tristate "Machine check injector support" 961 ---help--- 962 Provide support for injecting machine checks for testing purposes. 963 If you don't know what a machine check is and you don't do kernel 964 QA it is safe to say n. 965 966config X86_THERMAL_VECTOR 967 def_bool y 968 depends on X86_MCE_INTEL 969 970config VM86 971 bool "Enable VM86 support" if EXPERT 972 default y 973 depends on X86_32 974 ---help--- 975 This option is required by programs like DOSEMU to run 16-bit legacy 976 code on X86 processors. It also may be needed by software like 977 XFree86 to initialize some video cards via BIOS. Disabling this 978 option saves about 6k. 979 980config TOSHIBA 981 tristate "Toshiba Laptop support" 982 depends on X86_32 983 ---help--- 984 This adds a driver to safely access the System Management Mode of 985 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 986 not work on models with a Phoenix BIOS. The System Management Mode 987 is used to set the BIOS and power saving options on Toshiba portables. 988 989 For information on utilities to make use of this driver see the 990 Toshiba Linux utilities web site at: 991 <http://www.buzzard.org.uk/toshiba/>. 992 993 Say Y if you intend to run this kernel on a Toshiba portable. 994 Say N otherwise. 995 996config I8K 997 tristate "Dell laptop support" 998 select HWMON 999 ---help--- 1000 This adds a driver to safely access the System Management Mode 1001 of the CPU on the Dell Inspiron 8000. The System Management Mode 1002 is used to read cpu temperature and cooling fan status and to 1003 control the fans on the I8K portables. 1004 1005 This driver has been tested only on the Inspiron 8000 but it may 1006 also work with other Dell laptops. You can force loading on other 1007 models by passing the parameter `force=1' to the module. Use at 1008 your own risk. 1009 1010 For information on utilities to make use of this driver see the 1011 I8K Linux utilities web site at: 1012 <http://people.debian.org/~dz/i8k/> 1013 1014 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1015 Say N otherwise. 1016 1017config X86_REBOOTFIXUPS 1018 bool "Enable X86 board specific fixups for reboot" 1019 depends on X86_32 1020 ---help--- 1021 This enables chipset and/or board specific fixups to be done 1022 in order to get reboot to work correctly. This is only needed on 1023 some combinations of hardware and BIOS. The symptom, for which 1024 this config is intended, is when reboot ends with a stalled/hung 1025 system. 1026 1027 Currently, the only fixup is for the Geode machines using 1028 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1029 1030 Say Y if you want to enable the fixup. Currently, it's safe to 1031 enable this option even if you don't need it. 1032 Say N otherwise. 1033 1034config MICROCODE 1035 tristate "CPU microcode loading support" 1036 select FW_LOADER 1037 ---help--- 1038 1039 If you say Y here, you will be able to update the microcode on 1040 certain Intel and AMD processors. The Intel support is for the 1041 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1042 Xeon etc. The AMD support is for families 0x10 and later. You will 1043 obviously need the actual microcode binary data itself which is not 1044 shipped with the Linux kernel. 1045 1046 This option selects the general module only, you need to select 1047 at least one vendor specific module as well. 1048 1049 To compile this driver as a module, choose M here: the module 1050 will be called microcode. 1051 1052config MICROCODE_INTEL 1053 bool "Intel microcode loading support" 1054 depends on MICROCODE 1055 default MICROCODE 1056 select FW_LOADER 1057 ---help--- 1058 This options enables microcode patch loading support for Intel 1059 processors. 1060 1061 For latest news and information on obtaining all the required 1062 Intel ingredients for this driver, check: 1063 <http://www.urbanmyth.org/microcode/>. 1064 1065config MICROCODE_AMD 1066 bool "AMD microcode loading support" 1067 depends on MICROCODE 1068 select FW_LOADER 1069 ---help--- 1070 If you select this option, microcode patch loading support for AMD 1071 processors will be enabled. 1072 1073config MICROCODE_OLD_INTERFACE 1074 def_bool y 1075 depends on MICROCODE 1076 1077config MICROCODE_INTEL_LIB 1078 def_bool y 1079 depends on MICROCODE_INTEL 1080 1081config MICROCODE_INTEL_EARLY 1082 def_bool n 1083 1084config MICROCODE_AMD_EARLY 1085 def_bool n 1086 1087config MICROCODE_EARLY 1088 bool "Early load microcode" 1089 depends on MICROCODE=y && BLK_DEV_INITRD 1090 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1091 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1092 default y 1093 help 1094 This option provides functionality to read additional microcode data 1095 at the beginning of initrd image. The data tells kernel to load 1096 microcode to CPU's as early as possible. No functional change if no 1097 microcode data is glued to the initrd, therefore it's safe to say Y. 1098 1099config X86_MSR 1100 tristate "/dev/cpu/*/msr - Model-specific register support" 1101 ---help--- 1102 This device gives privileged processes access to the x86 1103 Model-Specific Registers (MSRs). It is a character device with 1104 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1105 MSR accesses are directed to a specific CPU on multi-processor 1106 systems. 1107 1108config X86_CPUID 1109 tristate "/dev/cpu/*/cpuid - CPU information support" 1110 ---help--- 1111 This device gives processes access to the x86 CPUID instruction to 1112 be executed on a specific processor. It is a character device 1113 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1114 /dev/cpu/31/cpuid. 1115 1116choice 1117 prompt "High Memory Support" 1118 default HIGHMEM64G if X86_NUMAQ 1119 default HIGHMEM4G 1120 depends on X86_32 1121 1122config NOHIGHMEM 1123 bool "off" 1124 depends on !X86_NUMAQ 1125 ---help--- 1126 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1127 However, the address space of 32-bit x86 processors is only 4 1128 Gigabytes large. That means that, if you have a large amount of 1129 physical memory, not all of it can be "permanently mapped" by the 1130 kernel. The physical memory that's not permanently mapped is called 1131 "high memory". 1132 1133 If you are compiling a kernel which will never run on a machine with 1134 more than 1 Gigabyte total physical RAM, answer "off" here (default 1135 choice and suitable for most users). This will result in a "3GB/1GB" 1136 split: 3GB are mapped so that each process sees a 3GB virtual memory 1137 space and the remaining part of the 4GB virtual memory space is used 1138 by the kernel to permanently map as much physical memory as 1139 possible. 1140 1141 If the machine has between 1 and 4 Gigabytes physical RAM, then 1142 answer "4GB" here. 1143 1144 If more than 4 Gigabytes is used then answer "64GB" here. This 1145 selection turns Intel PAE (Physical Address Extension) mode on. 1146 PAE implements 3-level paging on IA32 processors. PAE is fully 1147 supported by Linux, PAE mode is implemented on all recent Intel 1148 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1149 then the kernel will not boot on CPUs that don't support PAE! 1150 1151 The actual amount of total physical memory will either be 1152 auto detected or can be forced by using a kernel command line option 1153 such as "mem=256M". (Try "man bootparam" or see the documentation of 1154 your boot loader (lilo or loadlin) about how to pass options to the 1155 kernel at boot time.) 1156 1157 If unsure, say "off". 1158 1159config HIGHMEM4G 1160 bool "4GB" 1161 depends on !X86_NUMAQ 1162 ---help--- 1163 Select this if you have a 32-bit processor and between 1 and 4 1164 gigabytes of physical RAM. 1165 1166config HIGHMEM64G 1167 bool "64GB" 1168 depends on !M486 1169 select X86_PAE 1170 ---help--- 1171 Select this if you have a 32-bit processor and more than 4 1172 gigabytes of physical RAM. 1173 1174endchoice 1175 1176choice 1177 prompt "Memory split" if EXPERT 1178 default VMSPLIT_3G 1179 depends on X86_32 1180 ---help--- 1181 Select the desired split between kernel and user memory. 1182 1183 If the address range available to the kernel is less than the 1184 physical memory installed, the remaining memory will be available 1185 as "high memory". Accessing high memory is a little more costly 1186 than low memory, as it needs to be mapped into the kernel first. 1187 Note that increasing the kernel address space limits the range 1188 available to user programs, making the address space there 1189 tighter. Selecting anything other than the default 3G/1G split 1190 will also likely make your kernel incompatible with binary-only 1191 kernel modules. 1192 1193 If you are not absolutely sure what you are doing, leave this 1194 option alone! 1195 1196 config VMSPLIT_3G 1197 bool "3G/1G user/kernel split" 1198 config VMSPLIT_3G_OPT 1199 depends on !X86_PAE 1200 bool "3G/1G user/kernel split (for full 1G low memory)" 1201 config VMSPLIT_2G 1202 bool "2G/2G user/kernel split" 1203 config VMSPLIT_2G_OPT 1204 depends on !X86_PAE 1205 bool "2G/2G user/kernel split (for full 2G low memory)" 1206 config VMSPLIT_1G 1207 bool "1G/3G user/kernel split" 1208endchoice 1209 1210config PAGE_OFFSET 1211 hex 1212 default 0xB0000000 if VMSPLIT_3G_OPT 1213 default 0x80000000 if VMSPLIT_2G 1214 default 0x78000000 if VMSPLIT_2G_OPT 1215 default 0x40000000 if VMSPLIT_1G 1216 default 0xC0000000 1217 depends on X86_32 1218 1219config HIGHMEM 1220 def_bool y 1221 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1222 1223config X86_PAE 1224 bool "PAE (Physical Address Extension) Support" 1225 depends on X86_32 && !HIGHMEM4G 1226 ---help--- 1227 PAE is required for NX support, and furthermore enables 1228 larger swapspace support for non-overcommit purposes. It 1229 has the cost of more pagetable lookup overhead, and also 1230 consumes more pagetable space per process. 1231 1232config ARCH_PHYS_ADDR_T_64BIT 1233 def_bool y 1234 depends on X86_64 || X86_PAE 1235 1236config ARCH_DMA_ADDR_T_64BIT 1237 def_bool y 1238 depends on X86_64 || HIGHMEM64G 1239 1240config DIRECT_GBPAGES 1241 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1242 default y 1243 depends on X86_64 1244 ---help--- 1245 Allow the kernel linear mapping to use 1GB pages on CPUs that 1246 support it. This can improve the kernel's performance a tiny bit by 1247 reducing TLB pressure. If in doubt, say "Y". 1248 1249# Common NUMA Features 1250config NUMA 1251 bool "Numa Memory Allocation and Scheduler Support" 1252 depends on SMP 1253 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI)) 1254 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1255 ---help--- 1256 Enable NUMA (Non Uniform Memory Access) support. 1257 1258 The kernel will try to allocate memory used by a CPU on the 1259 local memory controller of the CPU and add some more 1260 NUMA awareness to the kernel. 1261 1262 For 64-bit this is recommended if the system is Intel Core i7 1263 (or later), AMD Opteron, or EM64T NUMA. 1264 1265 For 32-bit this is only needed on (rare) 32-bit-only platforms 1266 that support NUMA topologies, such as NUMAQ / Summit, or if you 1267 boot a 32-bit kernel on a 64-bit NUMA platform. 1268 1269 Otherwise, you should say N. 1270 1271comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1272 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1273 1274config AMD_NUMA 1275 def_bool y 1276 prompt "Old style AMD Opteron NUMA detection" 1277 depends on X86_64 && NUMA && PCI 1278 ---help--- 1279 Enable AMD NUMA node topology detection. You should say Y here if 1280 you have a multi processor AMD system. This uses an old method to 1281 read the NUMA configuration directly from the builtin Northbridge 1282 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1283 which also takes priority if both are compiled in. 1284 1285config X86_64_ACPI_NUMA 1286 def_bool y 1287 prompt "ACPI NUMA detection" 1288 depends on X86_64 && NUMA && ACPI && PCI 1289 select ACPI_NUMA 1290 ---help--- 1291 Enable ACPI SRAT based node topology detection. 1292 1293# Some NUMA nodes have memory ranges that span 1294# other nodes. Even though a pfn is valid and 1295# between a node's start and end pfns, it may not 1296# reside on that node. See memmap_init_zone() 1297# for details. 1298config NODES_SPAN_OTHER_NODES 1299 def_bool y 1300 depends on X86_64_ACPI_NUMA 1301 1302config NUMA_EMU 1303 bool "NUMA emulation" 1304 depends on NUMA 1305 ---help--- 1306 Enable NUMA emulation. A flat machine will be split 1307 into virtual nodes when booted with "numa=fake=N", where N is the 1308 number of nodes. This is only useful for debugging. 1309 1310config NODES_SHIFT 1311 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1312 range 1 10 1313 default "10" if MAXSMP 1314 default "6" if X86_64 1315 default "4" if X86_NUMAQ 1316 default "3" 1317 depends on NEED_MULTIPLE_NODES 1318 ---help--- 1319 Specify the maximum number of NUMA Nodes available on the target 1320 system. Increases memory reserved to accommodate various tables. 1321 1322config ARCH_HAVE_MEMORY_PRESENT 1323 def_bool y 1324 depends on X86_32 && DISCONTIGMEM 1325 1326config NEED_NODE_MEMMAP_SIZE 1327 def_bool y 1328 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1329 1330config ARCH_FLATMEM_ENABLE 1331 def_bool y 1332 depends on X86_32 && !NUMA 1333 1334config ARCH_DISCONTIGMEM_ENABLE 1335 def_bool y 1336 depends on NUMA && X86_32 1337 1338config ARCH_DISCONTIGMEM_DEFAULT 1339 def_bool y 1340 depends on NUMA && X86_32 1341 1342config ARCH_SPARSEMEM_ENABLE 1343 def_bool y 1344 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1345 select SPARSEMEM_STATIC if X86_32 1346 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1347 1348config ARCH_SPARSEMEM_DEFAULT 1349 def_bool y 1350 depends on X86_64 1351 1352config ARCH_SELECT_MEMORY_MODEL 1353 def_bool y 1354 depends on ARCH_SPARSEMEM_ENABLE 1355 1356config ARCH_MEMORY_PROBE 1357 bool "Enable sysfs memory/probe interface" 1358 depends on X86_64 && MEMORY_HOTPLUG 1359 help 1360 This option enables a sysfs memory/probe interface for testing. 1361 See Documentation/memory-hotplug.txt for more information. 1362 If you are unsure how to answer this question, answer N. 1363 1364config ARCH_PROC_KCORE_TEXT 1365 def_bool y 1366 depends on X86_64 && PROC_KCORE 1367 1368config ILLEGAL_POINTER_VALUE 1369 hex 1370 default 0 if X86_32 1371 default 0xdead000000000000 if X86_64 1372 1373source "mm/Kconfig" 1374 1375config HIGHPTE 1376 bool "Allocate 3rd-level pagetables from highmem" 1377 depends on HIGHMEM 1378 ---help--- 1379 The VM uses one page table entry for each page of physical memory. 1380 For systems with a lot of RAM, this can be wasteful of precious 1381 low memory. Setting this option will put user-space page table 1382 entries in high memory. 1383 1384config X86_CHECK_BIOS_CORRUPTION 1385 bool "Check for low memory corruption" 1386 ---help--- 1387 Periodically check for memory corruption in low memory, which 1388 is suspected to be caused by BIOS. Even when enabled in the 1389 configuration, it is disabled at runtime. Enable it by 1390 setting "memory_corruption_check=1" on the kernel command 1391 line. By default it scans the low 64k of memory every 60 1392 seconds; see the memory_corruption_check_size and 1393 memory_corruption_check_period parameters in 1394 Documentation/kernel-parameters.txt to adjust this. 1395 1396 When enabled with the default parameters, this option has 1397 almost no overhead, as it reserves a relatively small amount 1398 of memory and scans it infrequently. It both detects corruption 1399 and prevents it from affecting the running system. 1400 1401 It is, however, intended as a diagnostic tool; if repeatable 1402 BIOS-originated corruption always affects the same memory, 1403 you can use memmap= to prevent the kernel from using that 1404 memory. 1405 1406config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1407 bool "Set the default setting of memory_corruption_check" 1408 depends on X86_CHECK_BIOS_CORRUPTION 1409 default y 1410 ---help--- 1411 Set whether the default state of memory_corruption_check is 1412 on or off. 1413 1414config X86_RESERVE_LOW 1415 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1416 default 64 1417 range 4 640 1418 ---help--- 1419 Specify the amount of low memory to reserve for the BIOS. 1420 1421 The first page contains BIOS data structures that the kernel 1422 must not use, so that page must always be reserved. 1423 1424 By default we reserve the first 64K of physical RAM, as a 1425 number of BIOSes are known to corrupt that memory range 1426 during events such as suspend/resume or monitor cable 1427 insertion, so it must not be used by the kernel. 1428 1429 You can set this to 4 if you are absolutely sure that you 1430 trust the BIOS to get all its memory reservations and usages 1431 right. If you know your BIOS have problems beyond the 1432 default 64K area, you can set this to 640 to avoid using the 1433 entire low memory range. 1434 1435 If you have doubts about the BIOS (e.g. suspend/resume does 1436 not work or there's kernel crashes after certain hardware 1437 hotplug events) then you might want to enable 1438 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1439 typical corruption patterns. 1440 1441 Leave this to the default value of 64 if you are unsure. 1442 1443config MATH_EMULATION 1444 bool 1445 prompt "Math emulation" if X86_32 1446 ---help--- 1447 Linux can emulate a math coprocessor (used for floating point 1448 operations) if you don't have one. 486DX and Pentium processors have 1449 a math coprocessor built in, 486SX and 386 do not, unless you added 1450 a 487DX or 387, respectively. (The messages during boot time can 1451 give you some hints here ["man dmesg"].) Everyone needs either a 1452 coprocessor or this emulation. 1453 1454 If you don't have a math coprocessor, you need to say Y here; if you 1455 say Y here even though you have a coprocessor, the coprocessor will 1456 be used nevertheless. (This behavior can be changed with the kernel 1457 command line option "no387", which comes handy if your coprocessor 1458 is broken. Try "man bootparam" or see the documentation of your boot 1459 loader (lilo or loadlin) about how to pass options to the kernel at 1460 boot time.) This means that it is a good idea to say Y here if you 1461 intend to use this kernel on different machines. 1462 1463 More information about the internals of the Linux math coprocessor 1464 emulation can be found in <file:arch/x86/math-emu/README>. 1465 1466 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1467 kernel, it won't hurt. 1468 1469config MTRR 1470 def_bool y 1471 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1472 ---help--- 1473 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1474 the Memory Type Range Registers (MTRRs) may be used to control 1475 processor access to memory ranges. This is most useful if you have 1476 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1477 allows bus write transfers to be combined into a larger transfer 1478 before bursting over the PCI/AGP bus. This can increase performance 1479 of image write operations 2.5 times or more. Saying Y here creates a 1480 /proc/mtrr file which may be used to manipulate your processor's 1481 MTRRs. Typically the X server should use this. 1482 1483 This code has a reasonably generic interface so that similar 1484 control registers on other processors can be easily supported 1485 as well: 1486 1487 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1488 Registers (ARRs) which provide a similar functionality to MTRRs. For 1489 these, the ARRs are used to emulate the MTRRs. 1490 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1491 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1492 write-combining. All of these processors are supported by this code 1493 and it makes sense to say Y here if you have one of them. 1494 1495 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1496 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1497 can lead to all sorts of problems, so it's good to say Y here. 1498 1499 You can safely say Y even if your machine doesn't have MTRRs, you'll 1500 just add about 9 KB to your kernel. 1501 1502 See <file:Documentation/x86/mtrr.txt> for more information. 1503 1504config MTRR_SANITIZER 1505 def_bool y 1506 prompt "MTRR cleanup support" 1507 depends on MTRR 1508 ---help--- 1509 Convert MTRR layout from continuous to discrete, so X drivers can 1510 add writeback entries. 1511 1512 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1513 The largest mtrr entry size for a continuous block can be set with 1514 mtrr_chunk_size. 1515 1516 If unsure, say Y. 1517 1518config MTRR_SANITIZER_ENABLE_DEFAULT 1519 int "MTRR cleanup enable value (0-1)" 1520 range 0 1 1521 default "0" 1522 depends on MTRR_SANITIZER 1523 ---help--- 1524 Enable mtrr cleanup default value 1525 1526config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1527 int "MTRR cleanup spare reg num (0-7)" 1528 range 0 7 1529 default "1" 1530 depends on MTRR_SANITIZER 1531 ---help--- 1532 mtrr cleanup spare entries default, it can be changed via 1533 mtrr_spare_reg_nr=N on the kernel command line. 1534 1535config X86_PAT 1536 def_bool y 1537 prompt "x86 PAT support" if EXPERT 1538 depends on MTRR 1539 ---help--- 1540 Use PAT attributes to setup page level cache control. 1541 1542 PATs are the modern equivalents of MTRRs and are much more 1543 flexible than MTRRs. 1544 1545 Say N here if you see bootup problems (boot crash, boot hang, 1546 spontaneous reboots) or a non-working video driver. 1547 1548 If unsure, say Y. 1549 1550config ARCH_USES_PG_UNCACHED 1551 def_bool y 1552 depends on X86_PAT 1553 1554config ARCH_RANDOM 1555 def_bool y 1556 prompt "x86 architectural random number generator" if EXPERT 1557 ---help--- 1558 Enable the x86 architectural RDRAND instruction 1559 (Intel Bull Mountain technology) to generate random numbers. 1560 If supported, this is a high bandwidth, cryptographically 1561 secure hardware random number generator. 1562 1563config X86_SMAP 1564 def_bool y 1565 prompt "Supervisor Mode Access Prevention" if EXPERT 1566 ---help--- 1567 Supervisor Mode Access Prevention (SMAP) is a security 1568 feature in newer Intel processors. There is a small 1569 performance cost if this enabled and turned on; there is 1570 also a small increase in the kernel size if this is enabled. 1571 1572 If unsure, say Y. 1573 1574config EFI 1575 bool "EFI runtime service support" 1576 depends on ACPI 1577 select UCS2_STRING 1578 ---help--- 1579 This enables the kernel to use EFI runtime services that are 1580 available (such as the EFI variable services). 1581 1582 This option is only useful on systems that have EFI firmware. 1583 In addition, you should use the latest ELILO loader available 1584 at <http://elilo.sourceforge.net> in order to take advantage 1585 of EFI runtime services. However, even with this option, the 1586 resultant kernel should continue to boot on existing non-EFI 1587 platforms. 1588 1589config EFI_STUB 1590 bool "EFI stub support" 1591 depends on EFI 1592 ---help--- 1593 This kernel feature allows a bzImage to be loaded directly 1594 by EFI firmware without the use of a bootloader. 1595 1596 See Documentation/x86/efi-stub.txt for more information. 1597 1598config SECCOMP 1599 def_bool y 1600 prompt "Enable seccomp to safely compute untrusted bytecode" 1601 ---help--- 1602 This kernel feature is useful for number crunching applications 1603 that may need to compute untrusted bytecode during their 1604 execution. By using pipes or other transports made available to 1605 the process as file descriptors supporting the read/write 1606 syscalls, it's possible to isolate those applications in 1607 their own address space using seccomp. Once seccomp is 1608 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1609 and the task is only allowed to execute a few safe syscalls 1610 defined by each seccomp mode. 1611 1612 If unsure, say Y. Only embedded should say N here. 1613 1614config CC_STACKPROTECTOR 1615 bool "Enable -fstack-protector buffer overflow detection" 1616 ---help--- 1617 This option turns on the -fstack-protector GCC feature. This 1618 feature puts, at the beginning of functions, a canary value on 1619 the stack just before the return address, and validates 1620 the value just before actually returning. Stack based buffer 1621 overflows (that need to overwrite this return address) now also 1622 overwrite the canary, which gets detected and the attack is then 1623 neutralized via a kernel panic. 1624 1625 This feature requires gcc version 4.2 or above, or a distribution 1626 gcc with the feature backported. Older versions are automatically 1627 detected and for those versions, this configuration option is 1628 ignored. (and a warning is printed during bootup) 1629 1630source kernel/Kconfig.hz 1631 1632config KEXEC 1633 bool "kexec system call" 1634 ---help--- 1635 kexec is a system call that implements the ability to shutdown your 1636 current kernel, and to start another kernel. It is like a reboot 1637 but it is independent of the system firmware. And like a reboot 1638 you can start any kernel with it, not just Linux. 1639 1640 The name comes from the similarity to the exec system call. 1641 1642 It is an ongoing process to be certain the hardware in a machine 1643 is properly shutdown, so do not be surprised if this code does not 1644 initially work for you. As of this writing the exact hardware 1645 interface is strongly in flux, so no good recommendation can be 1646 made. 1647 1648config CRASH_DUMP 1649 bool "kernel crash dumps" 1650 depends on X86_64 || (X86_32 && HIGHMEM) 1651 ---help--- 1652 Generate crash dump after being started by kexec. 1653 This should be normally only set in special crash dump kernels 1654 which are loaded in the main kernel with kexec-tools into 1655 a specially reserved region and then later executed after 1656 a crash by kdump/kexec. The crash dump kernel must be compiled 1657 to a memory address not used by the main kernel or BIOS using 1658 PHYSICAL_START, or it must be built as a relocatable image 1659 (CONFIG_RELOCATABLE=y). 1660 For more details see Documentation/kdump/kdump.txt 1661 1662config KEXEC_JUMP 1663 bool "kexec jump" 1664 depends on KEXEC && HIBERNATION 1665 ---help--- 1666 Jump between original kernel and kexeced kernel and invoke 1667 code in physical address mode via KEXEC 1668 1669config PHYSICAL_START 1670 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1671 default "0x1000000" 1672 ---help--- 1673 This gives the physical address where the kernel is loaded. 1674 1675 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1676 bzImage will decompress itself to above physical address and 1677 run from there. Otherwise, bzImage will run from the address where 1678 it has been loaded by the boot loader and will ignore above physical 1679 address. 1680 1681 In normal kdump cases one does not have to set/change this option 1682 as now bzImage can be compiled as a completely relocatable image 1683 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1684 address. This option is mainly useful for the folks who don't want 1685 to use a bzImage for capturing the crash dump and want to use a 1686 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1687 to be specifically compiled to run from a specific memory area 1688 (normally a reserved region) and this option comes handy. 1689 1690 So if you are using bzImage for capturing the crash dump, 1691 leave the value here unchanged to 0x1000000 and set 1692 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1693 for capturing the crash dump change this value to start of 1694 the reserved region. In other words, it can be set based on 1695 the "X" value as specified in the "crashkernel=YM@XM" 1696 command line boot parameter passed to the panic-ed 1697 kernel. Please take a look at Documentation/kdump/kdump.txt 1698 for more details about crash dumps. 1699 1700 Usage of bzImage for capturing the crash dump is recommended as 1701 one does not have to build two kernels. Same kernel can be used 1702 as production kernel and capture kernel. Above option should have 1703 gone away after relocatable bzImage support is introduced. But it 1704 is present because there are users out there who continue to use 1705 vmlinux for dump capture. This option should go away down the 1706 line. 1707 1708 Don't change this unless you know what you are doing. 1709 1710config RELOCATABLE 1711 bool "Build a relocatable kernel" 1712 default y 1713 ---help--- 1714 This builds a kernel image that retains relocation information 1715 so it can be loaded someplace besides the default 1MB. 1716 The relocations tend to make the kernel binary about 10% larger, 1717 but are discarded at runtime. 1718 1719 One use is for the kexec on panic case where the recovery kernel 1720 must live at a different physical address than the primary 1721 kernel. 1722 1723 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1724 it has been loaded at and the compile time physical address 1725 (CONFIG_PHYSICAL_START) is ignored. 1726 1727# Relocation on x86-32 needs some additional build support 1728config X86_NEED_RELOCS 1729 def_bool y 1730 depends on X86_32 && RELOCATABLE 1731 1732config PHYSICAL_ALIGN 1733 hex "Alignment value to which kernel should be aligned" 1734 default "0x1000000" 1735 range 0x2000 0x1000000 if X86_32 1736 range 0x200000 0x1000000 if X86_64 1737 ---help--- 1738 This value puts the alignment restrictions on physical address 1739 where kernel is loaded and run from. Kernel is compiled for an 1740 address which meets above alignment restriction. 1741 1742 If bootloader loads the kernel at a non-aligned address and 1743 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1744 address aligned to above value and run from there. 1745 1746 If bootloader loads the kernel at a non-aligned address and 1747 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1748 load address and decompress itself to the address it has been 1749 compiled for and run from there. The address for which kernel is 1750 compiled already meets above alignment restrictions. Hence the 1751 end result is that kernel runs from a physical address meeting 1752 above alignment restrictions. 1753 1754 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1755 this value must be a multiple of 0x200000. 1756 1757 Don't change this unless you know what you are doing. 1758 1759config HOTPLUG_CPU 1760 bool "Support for hot-pluggable CPUs" 1761 depends on SMP 1762 ---help--- 1763 Say Y here to allow turning CPUs off and on. CPUs can be 1764 controlled through /sys/devices/system/cpu. 1765 ( Note: power management support will enable this option 1766 automatically on SMP systems. ) 1767 Say N if you want to disable CPU hotplug. 1768 1769config BOOTPARAM_HOTPLUG_CPU0 1770 bool "Set default setting of cpu0_hotpluggable" 1771 default n 1772 depends on HOTPLUG_CPU 1773 ---help--- 1774 Set whether default state of cpu0_hotpluggable is on or off. 1775 1776 Say Y here to enable CPU0 hotplug by default. If this switch 1777 is turned on, there is no need to give cpu0_hotplug kernel 1778 parameter and the CPU0 hotplug feature is enabled by default. 1779 1780 Please note: there are two known CPU0 dependencies if you want 1781 to enable the CPU0 hotplug feature either by this switch or by 1782 cpu0_hotplug kernel parameter. 1783 1784 First, resume from hibernate or suspend always starts from CPU0. 1785 So hibernate and suspend are prevented if CPU0 is offline. 1786 1787 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1788 offline if any interrupt can not migrate out of CPU0. There may 1789 be other CPU0 dependencies. 1790 1791 Please make sure the dependencies are under your control before 1792 you enable this feature. 1793 1794 Say N if you don't want to enable CPU0 hotplug feature by default. 1795 You still can enable the CPU0 hotplug feature at boot by kernel 1796 parameter cpu0_hotplug. 1797 1798config DEBUG_HOTPLUG_CPU0 1799 def_bool n 1800 prompt "Debug CPU0 hotplug" 1801 depends on HOTPLUG_CPU 1802 ---help--- 1803 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1804 soon as possible and boots up userspace with CPU0 offlined. User 1805 can online CPU0 back after boot time. 1806 1807 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1808 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1809 compilation or giving cpu0_hotplug kernel parameter at boot. 1810 1811 If unsure, say N. 1812 1813config COMPAT_VDSO 1814 def_bool y 1815 prompt "Compat VDSO support" 1816 depends on X86_32 || IA32_EMULATION 1817 ---help--- 1818 Map the 32-bit VDSO to the predictable old-style address too. 1819 1820 Say N here if you are running a sufficiently recent glibc 1821 version (2.3.3 or later), to remove the high-mapped 1822 VDSO mapping and to exclusively use the randomized VDSO. 1823 1824 If unsure, say Y. 1825 1826config CMDLINE_BOOL 1827 bool "Built-in kernel command line" 1828 ---help--- 1829 Allow for specifying boot arguments to the kernel at 1830 build time. On some systems (e.g. embedded ones), it is 1831 necessary or convenient to provide some or all of the 1832 kernel boot arguments with the kernel itself (that is, 1833 to not rely on the boot loader to provide them.) 1834 1835 To compile command line arguments into the kernel, 1836 set this option to 'Y', then fill in the 1837 the boot arguments in CONFIG_CMDLINE. 1838 1839 Systems with fully functional boot loaders (i.e. non-embedded) 1840 should leave this option set to 'N'. 1841 1842config CMDLINE 1843 string "Built-in kernel command string" 1844 depends on CMDLINE_BOOL 1845 default "" 1846 ---help--- 1847 Enter arguments here that should be compiled into the kernel 1848 image and used at boot time. If the boot loader provides a 1849 command line at boot time, it is appended to this string to 1850 form the full kernel command line, when the system boots. 1851 1852 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1853 change this behavior. 1854 1855 In most cases, the command line (whether built-in or provided 1856 by the boot loader) should specify the device for the root 1857 file system. 1858 1859config CMDLINE_OVERRIDE 1860 bool "Built-in command line overrides boot loader arguments" 1861 depends on CMDLINE_BOOL 1862 ---help--- 1863 Set this option to 'Y' to have the kernel ignore the boot loader 1864 command line, and use ONLY the built-in command line. 1865 1866 This is used to work around broken boot loaders. This should 1867 be set to 'N' under normal conditions. 1868 1869endmenu 1870 1871config ARCH_ENABLE_MEMORY_HOTPLUG 1872 def_bool y 1873 depends on X86_64 || (X86_32 && HIGHMEM) 1874 1875config ARCH_ENABLE_MEMORY_HOTREMOVE 1876 def_bool y 1877 depends on MEMORY_HOTPLUG 1878 1879config USE_PERCPU_NUMA_NODE_ID 1880 def_bool y 1881 depends on NUMA 1882 1883menu "Power management and ACPI options" 1884 1885config ARCH_HIBERNATION_HEADER 1886 def_bool y 1887 depends on X86_64 && HIBERNATION 1888 1889source "kernel/power/Kconfig" 1890 1891source "drivers/acpi/Kconfig" 1892 1893source "drivers/sfi/Kconfig" 1894 1895config X86_APM_BOOT 1896 def_bool y 1897 depends on APM 1898 1899menuconfig APM 1900 tristate "APM (Advanced Power Management) BIOS support" 1901 depends on X86_32 && PM_SLEEP 1902 ---help--- 1903 APM is a BIOS specification for saving power using several different 1904 techniques. This is mostly useful for battery powered laptops with 1905 APM compliant BIOSes. If you say Y here, the system time will be 1906 reset after a RESUME operation, the /proc/apm device will provide 1907 battery status information, and user-space programs will receive 1908 notification of APM "events" (e.g. battery status change). 1909 1910 If you select "Y" here, you can disable actual use of the APM 1911 BIOS by passing the "apm=off" option to the kernel at boot time. 1912 1913 Note that the APM support is almost completely disabled for 1914 machines with more than one CPU. 1915 1916 In order to use APM, you will need supporting software. For location 1917 and more information, read <file:Documentation/power/apm-acpi.txt> 1918 and the Battery Powered Linux mini-HOWTO, available from 1919 <http://www.tldp.org/docs.html#howto>. 1920 1921 This driver does not spin down disk drives (see the hdparm(8) 1922 manpage ("man 8 hdparm") for that), and it doesn't turn off 1923 VESA-compliant "green" monitors. 1924 1925 This driver does not support the TI 4000M TravelMate and the ACER 1926 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1927 desktop machines also don't have compliant BIOSes, and this driver 1928 may cause those machines to panic during the boot phase. 1929 1930 Generally, if you don't have a battery in your machine, there isn't 1931 much point in using this driver and you should say N. If you get 1932 random kernel OOPSes or reboots that don't seem to be related to 1933 anything, try disabling/enabling this option (or disabling/enabling 1934 APM in your BIOS). 1935 1936 Some other things you should try when experiencing seemingly random, 1937 "weird" problems: 1938 1939 1) make sure that you have enough swap space and that it is 1940 enabled. 1941 2) pass the "no-hlt" option to the kernel 1942 3) switch on floating point emulation in the kernel and pass 1943 the "no387" option to the kernel 1944 4) pass the "floppy=nodma" option to the kernel 1945 5) pass the "mem=4M" option to the kernel (thereby disabling 1946 all but the first 4 MB of RAM) 1947 6) make sure that the CPU is not over clocked. 1948 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1949 8) disable the cache from your BIOS settings 1950 9) install a fan for the video card or exchange video RAM 1951 10) install a better fan for the CPU 1952 11) exchange RAM chips 1953 12) exchange the motherboard. 1954 1955 To compile this driver as a module, choose M here: the 1956 module will be called apm. 1957 1958if APM 1959 1960config APM_IGNORE_USER_SUSPEND 1961 bool "Ignore USER SUSPEND" 1962 ---help--- 1963 This option will ignore USER SUSPEND requests. On machines with a 1964 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1965 series notebooks, it is necessary to say Y because of a BIOS bug. 1966 1967config APM_DO_ENABLE 1968 bool "Enable PM at boot time" 1969 ---help--- 1970 Enable APM features at boot time. From page 36 of the APM BIOS 1971 specification: "When disabled, the APM BIOS does not automatically 1972 power manage devices, enter the Standby State, enter the Suspend 1973 State, or take power saving steps in response to CPU Idle calls." 1974 This driver will make CPU Idle calls when Linux is idle (unless this 1975 feature is turned off -- see "Do CPU IDLE calls", below). This 1976 should always save battery power, but more complicated APM features 1977 will be dependent on your BIOS implementation. You may need to turn 1978 this option off if your computer hangs at boot time when using APM 1979 support, or if it beeps continuously instead of suspending. Turn 1980 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1981 T400CDT. This is off by default since most machines do fine without 1982 this feature. 1983 1984config APM_CPU_IDLE 1985 depends on CPU_IDLE 1986 bool "Make CPU Idle calls when idle" 1987 ---help--- 1988 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1989 On some machines, this can activate improved power savings, such as 1990 a slowed CPU clock rate, when the machine is idle. These idle calls 1991 are made after the idle loop has run for some length of time (e.g., 1992 333 mS). On some machines, this will cause a hang at boot time or 1993 whenever the CPU becomes idle. (On machines with more than one CPU, 1994 this option does nothing.) 1995 1996config APM_DISPLAY_BLANK 1997 bool "Enable console blanking using APM" 1998 ---help--- 1999 Enable console blanking using the APM. Some laptops can use this to 2000 turn off the LCD backlight when the screen blanker of the Linux 2001 virtual console blanks the screen. Note that this is only used by 2002 the virtual console screen blanker, and won't turn off the backlight 2003 when using the X Window system. This also doesn't have anything to 2004 do with your VESA-compliant power-saving monitor. Further, this 2005 option doesn't work for all laptops -- it might not turn off your 2006 backlight at all, or it might print a lot of errors to the console, 2007 especially if you are using gpm. 2008 2009config APM_ALLOW_INTS 2010 bool "Allow interrupts during APM BIOS calls" 2011 ---help--- 2012 Normally we disable external interrupts while we are making calls to 2013 the APM BIOS as a measure to lessen the effects of a badly behaving 2014 BIOS implementation. The BIOS should reenable interrupts if it 2015 needs to. Unfortunately, some BIOSes do not -- especially those in 2016 many of the newer IBM Thinkpads. If you experience hangs when you 2017 suspend, try setting this to Y. Otherwise, say N. 2018 2019endif # APM 2020 2021source "drivers/cpufreq/Kconfig" 2022 2023source "drivers/cpuidle/Kconfig" 2024 2025source "drivers/idle/Kconfig" 2026 2027endmenu 2028 2029 2030menu "Bus options (PCI etc.)" 2031 2032config PCI 2033 bool "PCI support" 2034 default y 2035 ---help--- 2036 Find out whether you have a PCI motherboard. PCI is the name of a 2037 bus system, i.e. the way the CPU talks to the other stuff inside 2038 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2039 VESA. If you have PCI, say Y, otherwise N. 2040 2041choice 2042 prompt "PCI access mode" 2043 depends on X86_32 && PCI 2044 default PCI_GOANY 2045 ---help--- 2046 On PCI systems, the BIOS can be used to detect the PCI devices and 2047 determine their configuration. However, some old PCI motherboards 2048 have BIOS bugs and may crash if this is done. Also, some embedded 2049 PCI-based systems don't have any BIOS at all. Linux can also try to 2050 detect the PCI hardware directly without using the BIOS. 2051 2052 With this option, you can specify how Linux should detect the 2053 PCI devices. If you choose "BIOS", the BIOS will be used, 2054 if you choose "Direct", the BIOS won't be used, and if you 2055 choose "MMConfig", then PCI Express MMCONFIG will be used. 2056 If you choose "Any", the kernel will try MMCONFIG, then the 2057 direct access method and falls back to the BIOS if that doesn't 2058 work. If unsure, go with the default, which is "Any". 2059 2060config PCI_GOBIOS 2061 bool "BIOS" 2062 2063config PCI_GOMMCONFIG 2064 bool "MMConfig" 2065 2066config PCI_GODIRECT 2067 bool "Direct" 2068 2069config PCI_GOOLPC 2070 bool "OLPC XO-1" 2071 depends on OLPC 2072 2073config PCI_GOANY 2074 bool "Any" 2075 2076endchoice 2077 2078config PCI_BIOS 2079 def_bool y 2080 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2081 2082# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2083config PCI_DIRECT 2084 def_bool y 2085 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2086 2087config PCI_MMCONFIG 2088 def_bool y 2089 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2090 2091config PCI_OLPC 2092 def_bool y 2093 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2094 2095config PCI_XEN 2096 def_bool y 2097 depends on PCI && XEN 2098 select SWIOTLB_XEN 2099 2100config PCI_DOMAINS 2101 def_bool y 2102 depends on PCI 2103 2104config PCI_MMCONFIG 2105 bool "Support mmconfig PCI config space access" 2106 depends on X86_64 && PCI && ACPI 2107 2108config PCI_CNB20LE_QUIRK 2109 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2110 depends on PCI 2111 help 2112 Read the PCI windows out of the CNB20LE host bridge. This allows 2113 PCI hotplug to work on systems with the CNB20LE chipset which do 2114 not have ACPI. 2115 2116 There's no public spec for this chipset, and this functionality 2117 is known to be incomplete. 2118 2119 You should say N unless you know you need this. 2120 2121source "drivers/pci/pcie/Kconfig" 2122 2123source "drivers/pci/Kconfig" 2124 2125# x86_64 have no ISA slots, but can have ISA-style DMA. 2126config ISA_DMA_API 2127 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2128 default y 2129 help 2130 Enables ISA-style DMA support for devices requiring such controllers. 2131 If unsure, say Y. 2132 2133if X86_32 2134 2135config ISA 2136 bool "ISA support" 2137 ---help--- 2138 Find out whether you have ISA slots on your motherboard. ISA is the 2139 name of a bus system, i.e. the way the CPU talks to the other stuff 2140 inside your box. Other bus systems are PCI, EISA, MicroChannel 2141 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2142 newer boards don't support it. If you have ISA, say Y, otherwise N. 2143 2144config EISA 2145 bool "EISA support" 2146 depends on ISA 2147 ---help--- 2148 The Extended Industry Standard Architecture (EISA) bus was 2149 developed as an open alternative to the IBM MicroChannel bus. 2150 2151 The EISA bus provided some of the features of the IBM MicroChannel 2152 bus while maintaining backward compatibility with cards made for 2153 the older ISA bus. The EISA bus saw limited use between 1988 and 2154 1995 when it was made obsolete by the PCI bus. 2155 2156 Say Y here if you are building a kernel for an EISA-based machine. 2157 2158 Otherwise, say N. 2159 2160source "drivers/eisa/Kconfig" 2161 2162config SCx200 2163 tristate "NatSemi SCx200 support" 2164 ---help--- 2165 This provides basic support for National Semiconductor's 2166 (now AMD's) Geode processors. The driver probes for the 2167 PCI-IDs of several on-chip devices, so its a good dependency 2168 for other scx200_* drivers. 2169 2170 If compiled as a module, the driver is named scx200. 2171 2172config SCx200HR_TIMER 2173 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2174 depends on SCx200 2175 default y 2176 ---help--- 2177 This driver provides a clocksource built upon the on-chip 2178 27MHz high-resolution timer. Its also a workaround for 2179 NSC Geode SC-1100's buggy TSC, which loses time when the 2180 processor goes idle (as is done by the scheduler). The 2181 other workaround is idle=poll boot option. 2182 2183config OLPC 2184 bool "One Laptop Per Child support" 2185 depends on !X86_PAE 2186 select GPIOLIB 2187 select OF 2188 select OF_PROMTREE 2189 select IRQ_DOMAIN 2190 ---help--- 2191 Add support for detecting the unique features of the OLPC 2192 XO hardware. 2193 2194config OLPC_XO1_PM 2195 bool "OLPC XO-1 Power Management" 2196 depends on OLPC && MFD_CS5535 && PM_SLEEP 2197 select MFD_CORE 2198 ---help--- 2199 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2200 2201config OLPC_XO1_RTC 2202 bool "OLPC XO-1 Real Time Clock" 2203 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2204 ---help--- 2205 Add support for the XO-1 real time clock, which can be used as a 2206 programmable wakeup source. 2207 2208config OLPC_XO1_SCI 2209 bool "OLPC XO-1 SCI extras" 2210 depends on OLPC && OLPC_XO1_PM 2211 depends on INPUT=y 2212 select POWER_SUPPLY 2213 select GPIO_CS5535 2214 select MFD_CORE 2215 ---help--- 2216 Add support for SCI-based features of the OLPC XO-1 laptop: 2217 - EC-driven system wakeups 2218 - Power button 2219 - Ebook switch 2220 - Lid switch 2221 - AC adapter status updates 2222 - Battery status updates 2223 2224config OLPC_XO15_SCI 2225 bool "OLPC XO-1.5 SCI extras" 2226 depends on OLPC && ACPI 2227 select POWER_SUPPLY 2228 ---help--- 2229 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2230 - EC-driven system wakeups 2231 - AC adapter status updates 2232 - Battery status updates 2233 2234config ALIX 2235 bool "PCEngines ALIX System Support (LED setup)" 2236 select GPIOLIB 2237 ---help--- 2238 This option enables system support for the PCEngines ALIX. 2239 At present this just sets up LEDs for GPIO control on 2240 ALIX2/3/6 boards. However, other system specific setup should 2241 get added here. 2242 2243 Note: You must still enable the drivers for GPIO and LED support 2244 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2245 2246 Note: You have to set alix.force=1 for boards with Award BIOS. 2247 2248config NET5501 2249 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2250 select GPIOLIB 2251 ---help--- 2252 This option enables system support for the Soekris Engineering net5501. 2253 2254config GEOS 2255 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2256 select GPIOLIB 2257 depends on DMI 2258 ---help--- 2259 This option enables system support for the Traverse Technologies GEOS. 2260 2261config TS5500 2262 bool "Technologic Systems TS-5500 platform support" 2263 depends on MELAN 2264 select CHECK_SIGNATURE 2265 select NEW_LEDS 2266 select LEDS_CLASS 2267 ---help--- 2268 This option enables system support for the Technologic Systems TS-5500. 2269 2270endif # X86_32 2271 2272config AMD_NB 2273 def_bool y 2274 depends on CPU_SUP_AMD && PCI 2275 2276source "drivers/pcmcia/Kconfig" 2277 2278source "drivers/pci/hotplug/Kconfig" 2279 2280config RAPIDIO 2281 tristate "RapidIO support" 2282 depends on PCI 2283 default n 2284 help 2285 If enabled this option will include drivers and the core 2286 infrastructure code to support RapidIO interconnect devices. 2287 2288source "drivers/rapidio/Kconfig" 2289 2290config X86_SYSFB 2291 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2292 help 2293 Firmwares often provide initial graphics framebuffers so the BIOS, 2294 bootloader or kernel can show basic video-output during boot for 2295 user-guidance and debugging. Historically, x86 used the VESA BIOS 2296 Extensions and EFI-framebuffers for this, which are mostly limited 2297 to x86. 2298 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2299 framebuffers so the new generic system-framebuffer drivers can be 2300 used on x86. If the framebuffer is not compatible with the generic 2301 modes, it is adverticed as fallback platform framebuffer so legacy 2302 drivers like efifb, vesafb and uvesafb can pick it up. 2303 If this option is not selected, all system framebuffers are always 2304 marked as fallback platform framebuffers as usual. 2305 2306 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2307 not be able to pick up generic system framebuffers if this option 2308 is selected. You are highly encouraged to enable simplefb as 2309 replacement if you select this option. simplefb can correctly deal 2310 with generic system framebuffers. But you should still keep vesafb 2311 and others enabled as fallback if a system framebuffer is 2312 incompatible with simplefb. 2313 2314 If unsure, say Y. 2315 2316endmenu 2317 2318 2319menu "Executable file formats / Emulations" 2320 2321source "fs/Kconfig.binfmt" 2322 2323config IA32_EMULATION 2324 bool "IA32 Emulation" 2325 depends on X86_64 2326 select BINFMT_ELF 2327 select COMPAT_BINFMT_ELF 2328 select HAVE_UID16 2329 ---help--- 2330 Include code to run legacy 32-bit programs under a 2331 64-bit kernel. You should likely turn this on, unless you're 2332 100% sure that you don't have any 32-bit programs left. 2333 2334config IA32_AOUT 2335 tristate "IA32 a.out support" 2336 depends on IA32_EMULATION 2337 ---help--- 2338 Support old a.out binaries in the 32bit emulation. 2339 2340config X86_X32 2341 bool "x32 ABI for 64-bit mode" 2342 depends on X86_64 && IA32_EMULATION 2343 ---help--- 2344 Include code to run binaries for the x32 native 32-bit ABI 2345 for 64-bit processors. An x32 process gets access to the 2346 full 64-bit register file and wide data path while leaving 2347 pointers at 32 bits for smaller memory footprint. 2348 2349 You will need a recent binutils (2.22 or later) with 2350 elf32_x86_64 support enabled to compile a kernel with this 2351 option set. 2352 2353config COMPAT 2354 def_bool y 2355 depends on IA32_EMULATION || X86_X32 2356 select ARCH_WANT_OLD_COMPAT_IPC 2357 2358if COMPAT 2359config COMPAT_FOR_U64_ALIGNMENT 2360 def_bool y 2361 2362config SYSVIPC_COMPAT 2363 def_bool y 2364 depends on SYSVIPC 2365 2366config KEYS_COMPAT 2367 def_bool y 2368 depends on KEYS 2369endif 2370 2371endmenu 2372 2373 2374config HAVE_ATOMIC_IOMAP 2375 def_bool y 2376 depends on X86_32 2377 2378config X86_DEV_DMA_OPS 2379 bool 2380 depends on X86_64 || STA2X11 2381 2382config X86_DMA_REMAP 2383 bool 2384 depends on STA2X11 2385 2386source "net/Kconfig" 2387 2388source "drivers/Kconfig" 2389 2390source "drivers/firmware/Kconfig" 2391 2392source "fs/Kconfig" 2393 2394source "arch/x86/Kconfig.debug" 2395 2396source "security/Kconfig" 2397 2398source "crypto/Kconfig" 2399 2400source "arch/x86/kvm/Kconfig" 2401 2402source "lib/Kconfig" 2403