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 ARCH_MIGHT_HAVE_PC_PARPORT 26 select ARCH_MIGHT_HAVE_PC_SERIO 27 select HAVE_AOUT if X86_32 28 select HAVE_UNSTABLE_SCHED_CLOCK 29 select ARCH_SUPPORTS_NUMA_BALANCING 30 select ARCH_SUPPORTS_INT128 if X86_64 31 select ARCH_WANTS_PROT_NUMA_PROT_NONE 32 select HAVE_IDE 33 select HAVE_OPROFILE 34 select HAVE_PCSPKR_PLATFORM 35 select HAVE_PERF_EVENTS 36 select HAVE_IOREMAP_PROT 37 select HAVE_KPROBES 38 select HAVE_MEMBLOCK 39 select HAVE_MEMBLOCK_NODE_MAP 40 select ARCH_DISCARD_MEMBLOCK 41 select ARCH_WANT_OPTIONAL_GPIOLIB 42 select ARCH_WANT_FRAME_POINTERS 43 select HAVE_DMA_ATTRS 44 select HAVE_DMA_CONTIGUOUS if !SWIOTLB 45 select HAVE_KRETPROBES 46 select HAVE_OPTPROBES 47 select HAVE_KPROBES_ON_FTRACE 48 select HAVE_FTRACE_MCOUNT_RECORD 49 select HAVE_FENTRY if X86_64 50 select HAVE_C_RECORDMCOUNT 51 select HAVE_DYNAMIC_FTRACE 52 select HAVE_DYNAMIC_FTRACE_WITH_REGS 53 select HAVE_FUNCTION_TRACER 54 select HAVE_FUNCTION_GRAPH_TRACER 55 select HAVE_FUNCTION_GRAPH_FP_TEST 56 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 57 select HAVE_SYSCALL_TRACEPOINTS 58 select SYSCTL_EXCEPTION_TRACE 59 select HAVE_KVM 60 select HAVE_ARCH_KGDB 61 select HAVE_ARCH_TRACEHOOK 62 select HAVE_GENERIC_DMA_COHERENT if X86_32 63 select HAVE_EFFICIENT_UNALIGNED_ACCESS 64 select USER_STACKTRACE_SUPPORT 65 select HAVE_REGS_AND_STACK_ACCESS_API 66 select HAVE_DMA_API_DEBUG 67 select HAVE_KERNEL_GZIP 68 select HAVE_KERNEL_BZIP2 69 select HAVE_KERNEL_LZMA 70 select HAVE_KERNEL_XZ 71 select HAVE_KERNEL_LZO 72 select HAVE_KERNEL_LZ4 73 select HAVE_HW_BREAKPOINT 74 select HAVE_MIXED_BREAKPOINTS_REGS 75 select PERF_EVENTS 76 select HAVE_PERF_EVENTS_NMI 77 select HAVE_PERF_REGS 78 select HAVE_PERF_USER_STACK_DUMP 79 select HAVE_DEBUG_KMEMLEAK 80 select ANON_INODES 81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 82 select HAVE_CMPXCHG_LOCAL 83 select HAVE_CMPXCHG_DOUBLE 84 select HAVE_ARCH_KMEMCHECK 85 select HAVE_USER_RETURN_NOTIFIER 86 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 87 select HAVE_ARCH_JUMP_LABEL 88 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 89 select SPARSE_IRQ 90 select GENERIC_FIND_FIRST_BIT 91 select GENERIC_IRQ_PROBE 92 select GENERIC_PENDING_IRQ if SMP 93 select GENERIC_IRQ_SHOW 94 select GENERIC_CLOCKEVENTS_MIN_ADJUST 95 select IRQ_FORCED_THREADING 96 select HAVE_BPF_JIT if X86_64 97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 98 select CLKEVT_I8253 99 select ARCH_HAVE_NMI_SAFE_CMPXCHG 100 select GENERIC_IOMAP 101 select DCACHE_WORD_ACCESS 102 select GENERIC_SMP_IDLE_THREAD 103 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 104 select HAVE_ARCH_SECCOMP_FILTER 105 select BUILDTIME_EXTABLE_SORT 106 select GENERIC_CMOS_UPDATE 107 select HAVE_ARCH_SOFT_DIRTY 108 select CLOCKSOURCE_WATCHDOG 109 select GENERIC_CLOCKEVENTS 110 select ARCH_CLOCKSOURCE_DATA if X86_64 111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 112 select GENERIC_TIME_VSYSCALL if X86_64 113 select KTIME_SCALAR if X86_32 114 select GENERIC_STRNCPY_FROM_USER 115 select GENERIC_STRNLEN_USER 116 select HAVE_CONTEXT_TRACKING if X86_64 117 select HAVE_IRQ_TIME_ACCOUNTING 118 select VIRT_TO_BUS 119 select MODULES_USE_ELF_REL if X86_32 120 select MODULES_USE_ELF_RELA if X86_64 121 select CLONE_BACKWARDS if X86_32 122 select ARCH_USE_BUILTIN_BSWAP 123 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 124 select OLD_SIGACTION if X86_32 125 select COMPAT_OLD_SIGACTION if IA32_EMULATION 126 select RTC_LIB 127 select HAVE_DEBUG_STACKOVERFLOW 128 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 129 select HAVE_CC_STACKPROTECTOR 130 131config INSTRUCTION_DECODER 132 def_bool y 133 depends on KPROBES || PERF_EVENTS || UPROBES 134 135config OUTPUT_FORMAT 136 string 137 default "elf32-i386" if X86_32 138 default "elf64-x86-64" if X86_64 139 140config ARCH_DEFCONFIG 141 string 142 default "arch/x86/configs/i386_defconfig" if X86_32 143 default "arch/x86/configs/x86_64_defconfig" if X86_64 144 145config LOCKDEP_SUPPORT 146 def_bool y 147 148config STACKTRACE_SUPPORT 149 def_bool y 150 151config HAVE_LATENCYTOP_SUPPORT 152 def_bool y 153 154config MMU 155 def_bool y 156 157config SBUS 158 bool 159 160config NEED_DMA_MAP_STATE 161 def_bool y 162 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 163 164config NEED_SG_DMA_LENGTH 165 def_bool y 166 167config GENERIC_ISA_DMA 168 def_bool y 169 depends on ISA_DMA_API 170 171config GENERIC_BUG 172 def_bool y 173 depends on BUG 174 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 175 176config GENERIC_BUG_RELATIVE_POINTERS 177 bool 178 179config GENERIC_HWEIGHT 180 def_bool y 181 182config ARCH_MAY_HAVE_PC_FDC 183 def_bool y 184 depends on ISA_DMA_API 185 186config RWSEM_XCHGADD_ALGORITHM 187 def_bool y 188 189config GENERIC_CALIBRATE_DELAY 190 def_bool y 191 192config ARCH_HAS_CPU_RELAX 193 def_bool y 194 195config ARCH_HAS_CACHE_LINE_SIZE 196 def_bool y 197 198config ARCH_HAS_CPU_AUTOPROBE 199 def_bool y 200 201config HAVE_SETUP_PER_CPU_AREA 202 def_bool y 203 204config NEED_PER_CPU_EMBED_FIRST_CHUNK 205 def_bool y 206 207config NEED_PER_CPU_PAGE_FIRST_CHUNK 208 def_bool y 209 210config ARCH_HIBERNATION_POSSIBLE 211 def_bool y 212 213config ARCH_SUSPEND_POSSIBLE 214 def_bool y 215 216config ARCH_WANT_HUGE_PMD_SHARE 217 def_bool y 218 219config ARCH_WANT_GENERAL_HUGETLB 220 def_bool y 221 222config ZONE_DMA32 223 bool 224 default X86_64 225 226config AUDIT_ARCH 227 bool 228 default X86_64 229 230config ARCH_SUPPORTS_OPTIMIZED_INLINING 231 def_bool y 232 233config ARCH_SUPPORTS_DEBUG_PAGEALLOC 234 def_bool y 235 236config HAVE_INTEL_TXT 237 def_bool y 238 depends on INTEL_IOMMU && ACPI 239 240config X86_32_SMP 241 def_bool y 242 depends on X86_32 && SMP 243 244config X86_64_SMP 245 def_bool y 246 depends on X86_64 && SMP 247 248config X86_HT 249 def_bool y 250 depends on SMP 251 252config X86_32_LAZY_GS 253 def_bool y 254 depends on X86_32 && !CC_STACKPROTECTOR 255 256config ARCH_HWEIGHT_CFLAGS 257 string 258 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 259 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_64 260 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, say N. If you have a system with more 284 than one CPU, say Y. 285 286 If you say N here, the kernel will run on uni- 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 uniprocessor machines. On a uniprocessor 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_INTEL_MID 444 bool "Intel MID platform support" 445 depends on X86_32 446 depends on X86_EXTENDED_PLATFORM 447 depends on X86_PLATFORM_DEVICES 448 depends on PCI 449 depends on PCI_GOANY 450 depends on X86_IO_APIC 451 select SFI 452 select I2C 453 select DW_APB_TIMER 454 select APB_TIMER 455 select INTEL_SCU_IPC 456 select MFD_INTEL_MSIC 457 ---help--- 458 Select to build a kernel capable of supporting Intel MID (Mobile 459 Internet Device) platform systems which do not have the PCI legacy 460 interfaces. If you are building for a PC class system say N here. 461 462 Intel MID platforms are based on an Intel processor and chipset which 463 consume less power than most of the x86 derivatives. 464 465config X86_INTEL_LPSS 466 bool "Intel Low Power Subsystem Support" 467 depends on ACPI 468 select COMMON_CLK 469 select PINCTRL 470 ---help--- 471 Select to build support for Intel Low Power Subsystem such as 472 found on Intel Lynxpoint PCH. Selecting this option enables 473 things like clock tree (common clock framework) and pincontrol 474 which are needed by the LPSS peripheral drivers. 475 476config X86_RDC321X 477 bool "RDC R-321x SoC" 478 depends on X86_32 479 depends on X86_EXTENDED_PLATFORM 480 select M486 481 select X86_REBOOTFIXUPS 482 ---help--- 483 This option is needed for RDC R-321x system-on-chip, also known 484 as R-8610-(G). 485 If you don't have one of these chips, you should say N here. 486 487config X86_32_NON_STANDARD 488 bool "Support non-standard 32-bit SMP architectures" 489 depends on X86_32 && SMP 490 depends on X86_EXTENDED_PLATFORM 491 ---help--- 492 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, 493 STA2X11, default subarchitectures. It is intended for a generic 494 binary kernel. If you select them all, kernel will probe it 495 one by one and will fallback to default. 496 497# Alphabetically sorted list of Non standard 32 bit platforms 498 499config X86_NUMAQ 500 bool "NUMAQ (IBM/Sequent)" 501 depends on X86_32_NON_STANDARD 502 depends on PCI 503 select NUMA 504 select X86_MPPARSE 505 ---help--- 506 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 507 NUMA multiquad box. This changes the way that processors are 508 bootstrapped, and uses Clustered Logical APIC addressing mode instead 509 of Flat Logical. You will need a new lynxer.elf file to flash your 510 firmware with - send email to <Martin.Bligh@us.ibm.com>. 511 512config X86_SUPPORTS_MEMORY_FAILURE 513 def_bool y 514 # MCE code calls memory_failure(): 515 depends on X86_MCE 516 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 517 depends on !X86_NUMAQ 518 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 519 depends on X86_64 || !SPARSEMEM 520 select ARCH_SUPPORTS_MEMORY_FAILURE 521 522config X86_VISWS 523 bool "SGI 320/540 (Visual Workstation)" 524 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 525 depends on X86_32_NON_STANDARD 526 ---help--- 527 The SGI Visual Workstation series is an IA32-based workstation 528 based on SGI systems chips with some legacy PC hardware attached. 529 530 Say Y here to create a kernel to run on the SGI 320 or 540. 531 532 A kernel compiled for the Visual Workstation will run on general 533 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 534 535config STA2X11 536 bool "STA2X11 Companion Chip Support" 537 depends on X86_32_NON_STANDARD && PCI 538 select X86_DEV_DMA_OPS 539 select X86_DMA_REMAP 540 select SWIOTLB 541 select MFD_STA2X11 542 select ARCH_REQUIRE_GPIOLIB 543 default n 544 ---help--- 545 This adds support for boards based on the STA2X11 IO-Hub, 546 a.k.a. "ConneXt". The chip is used in place of the standard 547 PC chipset, so all "standard" peripherals are missing. If this 548 option is selected the kernel will still be able to boot on 549 standard PC machines. 550 551config X86_SUMMIT 552 bool "Summit/EXA (IBM x440)" 553 depends on X86_32_NON_STANDARD 554 ---help--- 555 This option is needed for IBM systems that use the Summit/EXA chipset. 556 In particular, it is needed for the x440. 557 558config X86_ES7000 559 bool "Unisys ES7000 IA32 series" 560 depends on X86_32_NON_STANDARD && X86_BIGSMP 561 ---help--- 562 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 563 supposed to run on an IA32-based Unisys ES7000 system. 564 565config X86_32_IRIS 566 tristate "Eurobraille/Iris poweroff module" 567 depends on X86_32 568 ---help--- 569 The Iris machines from EuroBraille do not have APM or ACPI support 570 to shut themselves down properly. A special I/O sequence is 571 needed to do so, which is what this module does at 572 kernel shutdown. 573 574 This is only for Iris machines from EuroBraille. 575 576 If unused, say N. 577 578config SCHED_OMIT_FRAME_POINTER 579 def_bool y 580 prompt "Single-depth WCHAN output" 581 depends on X86 582 ---help--- 583 Calculate simpler /proc/<PID>/wchan values. If this option 584 is disabled then wchan values will recurse back to the 585 caller function. This provides more accurate wchan values, 586 at the expense of slightly more scheduling overhead. 587 588 If in doubt, say "Y". 589 590menuconfig HYPERVISOR_GUEST 591 bool "Linux guest support" 592 ---help--- 593 Say Y here to enable options for running Linux under various hyper- 594 visors. This option enables basic hypervisor detection and platform 595 setup. 596 597 If you say N, all options in this submenu will be skipped and 598 disabled, and Linux guest support won't be built in. 599 600if HYPERVISOR_GUEST 601 602config PARAVIRT 603 bool "Enable paravirtualization code" 604 ---help--- 605 This changes the kernel so it can modify itself when it is run 606 under a hypervisor, potentially improving performance significantly 607 over full virtualization. However, when run without a hypervisor 608 the kernel is theoretically slower and slightly larger. 609 610config PARAVIRT_DEBUG 611 bool "paravirt-ops debugging" 612 depends on PARAVIRT && DEBUG_KERNEL 613 ---help--- 614 Enable to debug paravirt_ops internals. Specifically, BUG if 615 a paravirt_op is missing when it is called. 616 617config PARAVIRT_SPINLOCKS 618 bool "Paravirtualization layer for spinlocks" 619 depends on PARAVIRT && SMP 620 select UNINLINE_SPIN_UNLOCK 621 ---help--- 622 Paravirtualized spinlocks allow a pvops backend to replace the 623 spinlock implementation with something virtualization-friendly 624 (for example, block the virtual CPU rather than spinning). 625 626 It has a minimal impact on native kernels and gives a nice performance 627 benefit on paravirtualized KVM / Xen kernels. 628 629 If you are unsure how to answer this question, answer Y. 630 631source "arch/x86/xen/Kconfig" 632 633config KVM_GUEST 634 bool "KVM Guest support (including kvmclock)" 635 depends on PARAVIRT 636 select PARAVIRT_CLOCK 637 default y 638 ---help--- 639 This option enables various optimizations for running under the KVM 640 hypervisor. It includes a paravirtualized clock, so that instead 641 of relying on a PIT (or probably other) emulation by the 642 underlying device model, the host provides the guest with 643 timing infrastructure such as time of day, and system time 644 645config KVM_DEBUG_FS 646 bool "Enable debug information for KVM Guests in debugfs" 647 depends on KVM_GUEST && DEBUG_FS 648 default n 649 ---help--- 650 This option enables collection of various statistics for KVM guest. 651 Statistics are displayed in debugfs filesystem. Enabling this option 652 may incur significant overhead. 653 654source "arch/x86/lguest/Kconfig" 655 656config PARAVIRT_TIME_ACCOUNTING 657 bool "Paravirtual steal time accounting" 658 depends on PARAVIRT 659 default n 660 ---help--- 661 Select this option to enable fine granularity task steal time 662 accounting. Time spent executing other tasks in parallel with 663 the current vCPU is discounted from the vCPU power. To account for 664 that, there can be a small performance impact. 665 666 If in doubt, say N here. 667 668config PARAVIRT_CLOCK 669 bool 670 671endif #HYPERVISOR_GUEST 672 673config NO_BOOTMEM 674 def_bool y 675 676config MEMTEST 677 bool "Memtest" 678 ---help--- 679 This option adds a kernel parameter 'memtest', which allows memtest 680 to be set. 681 memtest=0, mean disabled; -- default 682 memtest=1, mean do 1 test pattern; 683 ... 684 memtest=4, mean do 4 test patterns. 685 If you are unsure how to answer this question, answer N. 686 687config X86_SUMMIT_NUMA 688 def_bool y 689 depends on X86_32 && NUMA && X86_32_NON_STANDARD 690 691config X86_CYCLONE_TIMER 692 def_bool y 693 depends on X86_SUMMIT 694 695source "arch/x86/Kconfig.cpu" 696 697config HPET_TIMER 698 def_bool X86_64 699 prompt "HPET Timer Support" if X86_32 700 ---help--- 701 Use the IA-PC HPET (High Precision Event Timer) to manage 702 time in preference to the PIT and RTC, if a HPET is 703 present. 704 HPET is the next generation timer replacing legacy 8254s. 705 The HPET provides a stable time base on SMP 706 systems, unlike the TSC, but it is more expensive to access, 707 as it is off-chip. You can find the HPET spec at 708 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 709 710 You can safely choose Y here. However, HPET will only be 711 activated if the platform and the BIOS support this feature. 712 Otherwise the 8254 will be used for timing services. 713 714 Choose N to continue using the legacy 8254 timer. 715 716config HPET_EMULATE_RTC 717 def_bool y 718 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 719 720config APB_TIMER 721 def_bool y if X86_INTEL_MID 722 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 723 select DW_APB_TIMER 724 depends on X86_INTEL_MID && SFI 725 help 726 APB timer is the replacement for 8254, HPET on X86 MID platforms. 727 The APBT provides a stable time base on SMP 728 systems, unlike the TSC, but it is more expensive to access, 729 as it is off-chip. APB timers are always running regardless of CPU 730 C states, they are used as per CPU clockevent device when possible. 731 732# Mark as expert because too many people got it wrong. 733# The code disables itself when not needed. 734config DMI 735 default y 736 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 737 bool "Enable DMI scanning" if EXPERT 738 ---help--- 739 Enabled scanning of DMI to identify machine quirks. Say Y 740 here unless you have verified that your setup is not 741 affected by entries in the DMI blacklist. Required by PNP 742 BIOS code. 743 744config GART_IOMMU 745 bool "Old AMD GART IOMMU support" 746 select SWIOTLB 747 depends on X86_64 && PCI && AMD_NB 748 ---help--- 749 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 750 GART based hardware IOMMUs. 751 752 The GART supports full DMA access for devices with 32-bit access 753 limitations, on systems with more than 3 GB. This is usually needed 754 for USB, sound, many IDE/SATA chipsets and some other devices. 755 756 Newer systems typically have a modern AMD IOMMU, supported via 757 the CONFIG_AMD_IOMMU=y config option. 758 759 In normal configurations this driver is only active when needed: 760 there's more than 3 GB of memory and the system contains a 761 32-bit limited device. 762 763 If unsure, say Y. 764 765config CALGARY_IOMMU 766 bool "IBM Calgary IOMMU support" 767 select SWIOTLB 768 depends on X86_64 && PCI 769 ---help--- 770 Support for hardware IOMMUs in IBM's xSeries x366 and x460 771 systems. Needed to run systems with more than 3GB of memory 772 properly with 32-bit PCI devices that do not support DAC 773 (Double Address Cycle). Calgary also supports bus level 774 isolation, where all DMAs pass through the IOMMU. This 775 prevents them from going anywhere except their intended 776 destination. This catches hard-to-find kernel bugs and 777 mis-behaving drivers and devices that do not use the DMA-API 778 properly to set up their DMA buffers. The IOMMU can be 779 turned off at boot time with the iommu=off parameter. 780 Normally the kernel will make the right choice by itself. 781 If unsure, say Y. 782 783config CALGARY_IOMMU_ENABLED_BY_DEFAULT 784 def_bool y 785 prompt "Should Calgary be enabled by default?" 786 depends on CALGARY_IOMMU 787 ---help--- 788 Should Calgary be enabled by default? if you choose 'y', Calgary 789 will be used (if it exists). If you choose 'n', Calgary will not be 790 used even if it exists. If you choose 'n' and would like to use 791 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 792 If unsure, say Y. 793 794# need this always selected by IOMMU for the VIA workaround 795config SWIOTLB 796 def_bool y if X86_64 797 ---help--- 798 Support for software bounce buffers used on x86-64 systems 799 which don't have a hardware IOMMU. Using this PCI devices 800 which can only access 32-bits of memory can be used on systems 801 with more than 3 GB of memory. 802 If unsure, say Y. 803 804config IOMMU_HELPER 805 def_bool y 806 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 807 808config MAXSMP 809 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 810 depends on X86_64 && SMP && DEBUG_KERNEL 811 select CPUMASK_OFFSTACK 812 ---help--- 813 Enable maximum number of CPUS and NUMA Nodes for this architecture. 814 If unsure, say N. 815 816config NR_CPUS 817 int "Maximum number of CPUs" if SMP && !MAXSMP 818 range 2 8 if SMP && X86_32 && !X86_BIGSMP 819 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 820 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 821 default "1" if !SMP 822 default "8192" if MAXSMP 823 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 824 default "8" if SMP 825 ---help--- 826 This allows you to specify the maximum number of CPUs which this 827 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 828 supported value is 4096, otherwise the maximum value is 512. The 829 minimum value which makes sense is 2. 830 831 This is purely to save memory - each supported CPU adds 832 approximately eight kilobytes to the kernel image. 833 834config SCHED_SMT 835 bool "SMT (Hyperthreading) scheduler support" 836 depends on X86_HT 837 ---help--- 838 SMT scheduler support improves the CPU scheduler's decision making 839 when dealing with Intel Pentium 4 chips with HyperThreading at a 840 cost of slightly increased overhead in some places. If unsure say 841 N here. 842 843config SCHED_MC 844 def_bool y 845 prompt "Multi-core scheduler support" 846 depends on X86_HT 847 ---help--- 848 Multi-core scheduler support improves the CPU scheduler's decision 849 making when dealing with multi-core CPU chips at a cost of slightly 850 increased overhead in some places. If unsure say N here. 851 852source "kernel/Kconfig.preempt" 853 854config X86_UP_APIC 855 bool "Local APIC support on uniprocessors" 856 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 857 ---help--- 858 A local APIC (Advanced Programmable Interrupt Controller) is an 859 integrated interrupt controller in the CPU. If you have a single-CPU 860 system which has a processor with a local APIC, you can say Y here to 861 enable and use it. If you say Y here even though your machine doesn't 862 have a local APIC, then the kernel will still run with no slowdown at 863 all. The local APIC supports CPU-generated self-interrupts (timer, 864 performance counters), and the NMI watchdog which detects hard 865 lockups. 866 867config X86_UP_IOAPIC 868 bool "IO-APIC support on uniprocessors" 869 depends on X86_UP_APIC 870 ---help--- 871 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 872 SMP-capable replacement for PC-style interrupt controllers. Most 873 SMP systems and many recent uniprocessor systems have one. 874 875 If you have a single-CPU system with an IO-APIC, you can say Y here 876 to use it. If you say Y here even though your machine doesn't have 877 an IO-APIC, then the kernel will still run with no slowdown at all. 878 879config X86_LOCAL_APIC 880 def_bool y 881 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 882 883config X86_IO_APIC 884 def_bool y 885 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 886 887config X86_VISWS_APIC 888 def_bool y 889 depends on X86_32 && X86_VISWS 890 891config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 892 bool "Reroute for broken boot IRQs" 893 depends on X86_IO_APIC 894 ---help--- 895 This option enables a workaround that fixes a source of 896 spurious interrupts. This is recommended when threaded 897 interrupt handling is used on systems where the generation of 898 superfluous "boot interrupts" cannot be disabled. 899 900 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 901 entry in the chipset's IO-APIC is masked (as, e.g. the RT 902 kernel does during interrupt handling). On chipsets where this 903 boot IRQ generation cannot be disabled, this workaround keeps 904 the original IRQ line masked so that only the equivalent "boot 905 IRQ" is delivered to the CPUs. The workaround also tells the 906 kernel to set up the IRQ handler on the boot IRQ line. In this 907 way only one interrupt is delivered to the kernel. Otherwise 908 the spurious second interrupt may cause the kernel to bring 909 down (vital) interrupt lines. 910 911 Only affects "broken" chipsets. Interrupt sharing may be 912 increased on these systems. 913 914config X86_MCE 915 bool "Machine Check / overheating reporting" 916 default y 917 ---help--- 918 Machine Check support allows the processor to notify the 919 kernel if it detects a problem (e.g. overheating, data corruption). 920 The action the kernel takes depends on the severity of the problem, 921 ranging from warning messages to halting the machine. 922 923config X86_MCE_INTEL 924 def_bool y 925 prompt "Intel MCE features" 926 depends on X86_MCE && X86_LOCAL_APIC 927 ---help--- 928 Additional support for intel specific MCE features such as 929 the thermal monitor. 930 931config X86_MCE_AMD 932 def_bool y 933 prompt "AMD MCE features" 934 depends on X86_MCE && X86_LOCAL_APIC 935 ---help--- 936 Additional support for AMD specific MCE features such as 937 the DRAM Error Threshold. 938 939config X86_ANCIENT_MCE 940 bool "Support for old Pentium 5 / WinChip machine checks" 941 depends on X86_32 && X86_MCE 942 ---help--- 943 Include support for machine check handling on old Pentium 5 or WinChip 944 systems. These typically need to be enabled explicitly on the command 945 line. 946 947config X86_MCE_THRESHOLD 948 depends on X86_MCE_AMD || X86_MCE_INTEL 949 def_bool y 950 951config X86_MCE_INJECT 952 depends on X86_MCE 953 tristate "Machine check injector support" 954 ---help--- 955 Provide support for injecting machine checks for testing purposes. 956 If you don't know what a machine check is and you don't do kernel 957 QA it is safe to say n. 958 959config X86_THERMAL_VECTOR 960 def_bool y 961 depends on X86_MCE_INTEL 962 963config VM86 964 bool "Enable VM86 support" if EXPERT 965 default y 966 depends on X86_32 967 ---help--- 968 This option is required by programs like DOSEMU to run 16-bit legacy 969 code on X86 processors. It also may be needed by software like 970 XFree86 to initialize some video cards via BIOS. Disabling this 971 option saves about 6k. 972 973config TOSHIBA 974 tristate "Toshiba Laptop support" 975 depends on X86_32 976 ---help--- 977 This adds a driver to safely access the System Management Mode of 978 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 979 not work on models with a Phoenix BIOS. The System Management Mode 980 is used to set the BIOS and power saving options on Toshiba portables. 981 982 For information on utilities to make use of this driver see the 983 Toshiba Linux utilities web site at: 984 <http://www.buzzard.org.uk/toshiba/>. 985 986 Say Y if you intend to run this kernel on a Toshiba portable. 987 Say N otherwise. 988 989config I8K 990 tristate "Dell laptop support" 991 select HWMON 992 ---help--- 993 This adds a driver to safely access the System Management Mode 994 of the CPU on the Dell Inspiron 8000. The System Management Mode 995 is used to read cpu temperature and cooling fan status and to 996 control the fans on the I8K portables. 997 998 This driver has been tested only on the Inspiron 8000 but it may 999 also work with other Dell laptops. You can force loading on other 1000 models by passing the parameter `force=1' to the module. Use at 1001 your own risk. 1002 1003 For information on utilities to make use of this driver see the 1004 I8K Linux utilities web site at: 1005 <http://people.debian.org/~dz/i8k/> 1006 1007 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1008 Say N otherwise. 1009 1010config X86_REBOOTFIXUPS 1011 bool "Enable X86 board specific fixups for reboot" 1012 depends on X86_32 1013 ---help--- 1014 This enables chipset and/or board specific fixups to be done 1015 in order to get reboot to work correctly. This is only needed on 1016 some combinations of hardware and BIOS. The symptom, for which 1017 this config is intended, is when reboot ends with a stalled/hung 1018 system. 1019 1020 Currently, the only fixup is for the Geode machines using 1021 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1022 1023 Say Y if you want to enable the fixup. Currently, it's safe to 1024 enable this option even if you don't need it. 1025 Say N otherwise. 1026 1027config MICROCODE 1028 tristate "CPU microcode loading support" 1029 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1030 select FW_LOADER 1031 ---help--- 1032 1033 If you say Y here, you will be able to update the microcode on 1034 certain Intel and AMD processors. The Intel support is for the 1035 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1036 Xeon etc. The AMD support is for families 0x10 and later. You will 1037 obviously need the actual microcode binary data itself which is not 1038 shipped with the Linux kernel. 1039 1040 This option selects the general module only, you need to select 1041 at least one vendor specific module as well. 1042 1043 To compile this driver as a module, choose M here: the module 1044 will be called microcode. 1045 1046config MICROCODE_INTEL 1047 bool "Intel microcode loading support" 1048 depends on MICROCODE 1049 default MICROCODE 1050 select FW_LOADER 1051 ---help--- 1052 This options enables microcode patch loading support for Intel 1053 processors. 1054 1055 For the current Intel microcode data package go to 1056 <https://downloadcenter.intel.com> and search for 1057 'Linux Processor Microcode Data File'. 1058 1059config MICROCODE_AMD 1060 bool "AMD microcode loading support" 1061 depends on MICROCODE 1062 select FW_LOADER 1063 ---help--- 1064 If you select this option, microcode patch loading support for AMD 1065 processors will be enabled. 1066 1067config MICROCODE_OLD_INTERFACE 1068 def_bool y 1069 depends on MICROCODE 1070 1071config MICROCODE_INTEL_EARLY 1072 def_bool n 1073 1074config MICROCODE_AMD_EARLY 1075 def_bool n 1076 1077config MICROCODE_EARLY 1078 bool "Early load microcode" 1079 depends on MICROCODE=y && BLK_DEV_INITRD 1080 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1081 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1082 default y 1083 help 1084 This option provides functionality to read additional microcode data 1085 at the beginning of initrd image. The data tells kernel to load 1086 microcode to CPU's as early as possible. No functional change if no 1087 microcode data is glued to the initrd, therefore it's safe to say Y. 1088 1089config X86_MSR 1090 tristate "/dev/cpu/*/msr - Model-specific register support" 1091 ---help--- 1092 This device gives privileged processes access to the x86 1093 Model-Specific Registers (MSRs). It is a character device with 1094 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1095 MSR accesses are directed to a specific CPU on multi-processor 1096 systems. 1097 1098config X86_CPUID 1099 tristate "/dev/cpu/*/cpuid - CPU information support" 1100 ---help--- 1101 This device gives processes access to the x86 CPUID instruction to 1102 be executed on a specific processor. It is a character device 1103 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1104 /dev/cpu/31/cpuid. 1105 1106choice 1107 prompt "High Memory Support" 1108 default HIGHMEM64G if X86_NUMAQ 1109 default HIGHMEM4G 1110 depends on X86_32 1111 1112config NOHIGHMEM 1113 bool "off" 1114 depends on !X86_NUMAQ 1115 ---help--- 1116 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1117 However, the address space of 32-bit x86 processors is only 4 1118 Gigabytes large. That means that, if you have a large amount of 1119 physical memory, not all of it can be "permanently mapped" by the 1120 kernel. The physical memory that's not permanently mapped is called 1121 "high memory". 1122 1123 If you are compiling a kernel which will never run on a machine with 1124 more than 1 Gigabyte total physical RAM, answer "off" here (default 1125 choice and suitable for most users). This will result in a "3GB/1GB" 1126 split: 3GB are mapped so that each process sees a 3GB virtual memory 1127 space and the remaining part of the 4GB virtual memory space is used 1128 by the kernel to permanently map as much physical memory as 1129 possible. 1130 1131 If the machine has between 1 and 4 Gigabytes physical RAM, then 1132 answer "4GB" here. 1133 1134 If more than 4 Gigabytes is used then answer "64GB" here. This 1135 selection turns Intel PAE (Physical Address Extension) mode on. 1136 PAE implements 3-level paging on IA32 processors. PAE is fully 1137 supported by Linux, PAE mode is implemented on all recent Intel 1138 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1139 then the kernel will not boot on CPUs that don't support PAE! 1140 1141 The actual amount of total physical memory will either be 1142 auto detected or can be forced by using a kernel command line option 1143 such as "mem=256M". (Try "man bootparam" or see the documentation of 1144 your boot loader (lilo or loadlin) about how to pass options to the 1145 kernel at boot time.) 1146 1147 If unsure, say "off". 1148 1149config HIGHMEM4G 1150 bool "4GB" 1151 depends on !X86_NUMAQ 1152 ---help--- 1153 Select this if you have a 32-bit processor and between 1 and 4 1154 gigabytes of physical RAM. 1155 1156config HIGHMEM64G 1157 bool "64GB" 1158 depends on !M486 1159 select X86_PAE 1160 ---help--- 1161 Select this if you have a 32-bit processor and more than 4 1162 gigabytes of physical RAM. 1163 1164endchoice 1165 1166choice 1167 prompt "Memory split" if EXPERT 1168 default VMSPLIT_3G 1169 depends on X86_32 1170 ---help--- 1171 Select the desired split between kernel and user memory. 1172 1173 If the address range available to the kernel is less than the 1174 physical memory installed, the remaining memory will be available 1175 as "high memory". Accessing high memory is a little more costly 1176 than low memory, as it needs to be mapped into the kernel first. 1177 Note that increasing the kernel address space limits the range 1178 available to user programs, making the address space there 1179 tighter. Selecting anything other than the default 3G/1G split 1180 will also likely make your kernel incompatible with binary-only 1181 kernel modules. 1182 1183 If you are not absolutely sure what you are doing, leave this 1184 option alone! 1185 1186 config VMSPLIT_3G 1187 bool "3G/1G user/kernel split" 1188 config VMSPLIT_3G_OPT 1189 depends on !X86_PAE 1190 bool "3G/1G user/kernel split (for full 1G low memory)" 1191 config VMSPLIT_2G 1192 bool "2G/2G user/kernel split" 1193 config VMSPLIT_2G_OPT 1194 depends on !X86_PAE 1195 bool "2G/2G user/kernel split (for full 2G low memory)" 1196 config VMSPLIT_1G 1197 bool "1G/3G user/kernel split" 1198endchoice 1199 1200config PAGE_OFFSET 1201 hex 1202 default 0xB0000000 if VMSPLIT_3G_OPT 1203 default 0x80000000 if VMSPLIT_2G 1204 default 0x78000000 if VMSPLIT_2G_OPT 1205 default 0x40000000 if VMSPLIT_1G 1206 default 0xC0000000 1207 depends on X86_32 1208 1209config HIGHMEM 1210 def_bool y 1211 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1212 1213config X86_PAE 1214 bool "PAE (Physical Address Extension) Support" 1215 depends on X86_32 && !HIGHMEM4G 1216 ---help--- 1217 PAE is required for NX support, and furthermore enables 1218 larger swapspace support for non-overcommit purposes. It 1219 has the cost of more pagetable lookup overhead, and also 1220 consumes more pagetable space per process. 1221 1222config ARCH_PHYS_ADDR_T_64BIT 1223 def_bool y 1224 depends on X86_64 || X86_PAE 1225 1226config ARCH_DMA_ADDR_T_64BIT 1227 def_bool y 1228 depends on X86_64 || HIGHMEM64G 1229 1230config DIRECT_GBPAGES 1231 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1232 default y 1233 depends on X86_64 1234 ---help--- 1235 Allow the kernel linear mapping to use 1GB pages on CPUs that 1236 support it. This can improve the kernel's performance a tiny bit by 1237 reducing TLB pressure. If in doubt, say "Y". 1238 1239# Common NUMA Features 1240config NUMA 1241 bool "Numa Memory Allocation and Scheduler Support" 1242 depends on SMP 1243 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI)) 1244 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1245 ---help--- 1246 Enable NUMA (Non Uniform Memory Access) support. 1247 1248 The kernel will try to allocate memory used by a CPU on the 1249 local memory controller of the CPU and add some more 1250 NUMA awareness to the kernel. 1251 1252 For 64-bit this is recommended if the system is Intel Core i7 1253 (or later), AMD Opteron, or EM64T NUMA. 1254 1255 For 32-bit this is only needed on (rare) 32-bit-only platforms 1256 that support NUMA topologies, such as NUMAQ / Summit, or if you 1257 boot a 32-bit kernel on a 64-bit NUMA platform. 1258 1259 Otherwise, you should say N. 1260 1261comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1262 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1263 1264config AMD_NUMA 1265 def_bool y 1266 prompt "Old style AMD Opteron NUMA detection" 1267 depends on X86_64 && NUMA && PCI 1268 ---help--- 1269 Enable AMD NUMA node topology detection. You should say Y here if 1270 you have a multi processor AMD system. This uses an old method to 1271 read the NUMA configuration directly from the builtin Northbridge 1272 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1273 which also takes priority if both are compiled in. 1274 1275config X86_64_ACPI_NUMA 1276 def_bool y 1277 prompt "ACPI NUMA detection" 1278 depends on X86_64 && NUMA && ACPI && PCI 1279 select ACPI_NUMA 1280 ---help--- 1281 Enable ACPI SRAT based node topology detection. 1282 1283# Some NUMA nodes have memory ranges that span 1284# other nodes. Even though a pfn is valid and 1285# between a node's start and end pfns, it may not 1286# reside on that node. See memmap_init_zone() 1287# for details. 1288config NODES_SPAN_OTHER_NODES 1289 def_bool y 1290 depends on X86_64_ACPI_NUMA 1291 1292config NUMA_EMU 1293 bool "NUMA emulation" 1294 depends on NUMA 1295 ---help--- 1296 Enable NUMA emulation. A flat machine will be split 1297 into virtual nodes when booted with "numa=fake=N", where N is the 1298 number of nodes. This is only useful for debugging. 1299 1300config NODES_SHIFT 1301 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1302 range 1 10 1303 default "10" if MAXSMP 1304 default "6" if X86_64 1305 default "4" if X86_NUMAQ 1306 default "3" 1307 depends on NEED_MULTIPLE_NODES 1308 ---help--- 1309 Specify the maximum number of NUMA Nodes available on the target 1310 system. Increases memory reserved to accommodate various tables. 1311 1312config ARCH_HAVE_MEMORY_PRESENT 1313 def_bool y 1314 depends on X86_32 && DISCONTIGMEM 1315 1316config NEED_NODE_MEMMAP_SIZE 1317 def_bool y 1318 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1319 1320config ARCH_FLATMEM_ENABLE 1321 def_bool y 1322 depends on X86_32 && !NUMA 1323 1324config ARCH_DISCONTIGMEM_ENABLE 1325 def_bool y 1326 depends on NUMA && X86_32 1327 1328config ARCH_DISCONTIGMEM_DEFAULT 1329 def_bool y 1330 depends on NUMA && X86_32 1331 1332config ARCH_SPARSEMEM_ENABLE 1333 def_bool y 1334 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1335 select SPARSEMEM_STATIC if X86_32 1336 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1337 1338config ARCH_SPARSEMEM_DEFAULT 1339 def_bool y 1340 depends on X86_64 1341 1342config ARCH_SELECT_MEMORY_MODEL 1343 def_bool y 1344 depends on ARCH_SPARSEMEM_ENABLE 1345 1346config ARCH_MEMORY_PROBE 1347 bool "Enable sysfs memory/probe interface" 1348 depends on X86_64 && MEMORY_HOTPLUG 1349 help 1350 This option enables a sysfs memory/probe interface for testing. 1351 See Documentation/memory-hotplug.txt for more information. 1352 If you are unsure how to answer this question, answer N. 1353 1354config ARCH_PROC_KCORE_TEXT 1355 def_bool y 1356 depends on X86_64 && PROC_KCORE 1357 1358config ILLEGAL_POINTER_VALUE 1359 hex 1360 default 0 if X86_32 1361 default 0xdead000000000000 if X86_64 1362 1363source "mm/Kconfig" 1364 1365config HIGHPTE 1366 bool "Allocate 3rd-level pagetables from highmem" 1367 depends on HIGHMEM 1368 ---help--- 1369 The VM uses one page table entry for each page of physical memory. 1370 For systems with a lot of RAM, this can be wasteful of precious 1371 low memory. Setting this option will put user-space page table 1372 entries in high memory. 1373 1374config X86_CHECK_BIOS_CORRUPTION 1375 bool "Check for low memory corruption" 1376 ---help--- 1377 Periodically check for memory corruption in low memory, which 1378 is suspected to be caused by BIOS. Even when enabled in the 1379 configuration, it is disabled at runtime. Enable it by 1380 setting "memory_corruption_check=1" on the kernel command 1381 line. By default it scans the low 64k of memory every 60 1382 seconds; see the memory_corruption_check_size and 1383 memory_corruption_check_period parameters in 1384 Documentation/kernel-parameters.txt to adjust this. 1385 1386 When enabled with the default parameters, this option has 1387 almost no overhead, as it reserves a relatively small amount 1388 of memory and scans it infrequently. It both detects corruption 1389 and prevents it from affecting the running system. 1390 1391 It is, however, intended as a diagnostic tool; if repeatable 1392 BIOS-originated corruption always affects the same memory, 1393 you can use memmap= to prevent the kernel from using that 1394 memory. 1395 1396config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1397 bool "Set the default setting of memory_corruption_check" 1398 depends on X86_CHECK_BIOS_CORRUPTION 1399 default y 1400 ---help--- 1401 Set whether the default state of memory_corruption_check is 1402 on or off. 1403 1404config X86_RESERVE_LOW 1405 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1406 default 64 1407 range 4 640 1408 ---help--- 1409 Specify the amount of low memory to reserve for the BIOS. 1410 1411 The first page contains BIOS data structures that the kernel 1412 must not use, so that page must always be reserved. 1413 1414 By default we reserve the first 64K of physical RAM, as a 1415 number of BIOSes are known to corrupt that memory range 1416 during events such as suspend/resume or monitor cable 1417 insertion, so it must not be used by the kernel. 1418 1419 You can set this to 4 if you are absolutely sure that you 1420 trust the BIOS to get all its memory reservations and usages 1421 right. If you know your BIOS have problems beyond the 1422 default 64K area, you can set this to 640 to avoid using the 1423 entire low memory range. 1424 1425 If you have doubts about the BIOS (e.g. suspend/resume does 1426 not work or there's kernel crashes after certain hardware 1427 hotplug events) then you might want to enable 1428 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1429 typical corruption patterns. 1430 1431 Leave this to the default value of 64 if you are unsure. 1432 1433config MATH_EMULATION 1434 bool 1435 prompt "Math emulation" if X86_32 1436 ---help--- 1437 Linux can emulate a math coprocessor (used for floating point 1438 operations) if you don't have one. 486DX and Pentium processors have 1439 a math coprocessor built in, 486SX and 386 do not, unless you added 1440 a 487DX or 387, respectively. (The messages during boot time can 1441 give you some hints here ["man dmesg"].) Everyone needs either a 1442 coprocessor or this emulation. 1443 1444 If you don't have a math coprocessor, you need to say Y here; if you 1445 say Y here even though you have a coprocessor, the coprocessor will 1446 be used nevertheless. (This behavior can be changed with the kernel 1447 command line option "no387", which comes handy if your coprocessor 1448 is broken. Try "man bootparam" or see the documentation of your boot 1449 loader (lilo or loadlin) about how to pass options to the kernel at 1450 boot time.) This means that it is a good idea to say Y here if you 1451 intend to use this kernel on different machines. 1452 1453 More information about the internals of the Linux math coprocessor 1454 emulation can be found in <file:arch/x86/math-emu/README>. 1455 1456 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1457 kernel, it won't hurt. 1458 1459config MTRR 1460 def_bool y 1461 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1462 ---help--- 1463 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1464 the Memory Type Range Registers (MTRRs) may be used to control 1465 processor access to memory ranges. This is most useful if you have 1466 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1467 allows bus write transfers to be combined into a larger transfer 1468 before bursting over the PCI/AGP bus. This can increase performance 1469 of image write operations 2.5 times or more. Saying Y here creates a 1470 /proc/mtrr file which may be used to manipulate your processor's 1471 MTRRs. Typically the X server should use this. 1472 1473 This code has a reasonably generic interface so that similar 1474 control registers on other processors can be easily supported 1475 as well: 1476 1477 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1478 Registers (ARRs) which provide a similar functionality to MTRRs. For 1479 these, the ARRs are used to emulate the MTRRs. 1480 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1481 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1482 write-combining. All of these processors are supported by this code 1483 and it makes sense to say Y here if you have one of them. 1484 1485 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1486 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1487 can lead to all sorts of problems, so it's good to say Y here. 1488 1489 You can safely say Y even if your machine doesn't have MTRRs, you'll 1490 just add about 9 KB to your kernel. 1491 1492 See <file:Documentation/x86/mtrr.txt> for more information. 1493 1494config MTRR_SANITIZER 1495 def_bool y 1496 prompt "MTRR cleanup support" 1497 depends on MTRR 1498 ---help--- 1499 Convert MTRR layout from continuous to discrete, so X drivers can 1500 add writeback entries. 1501 1502 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1503 The largest mtrr entry size for a continuous block can be set with 1504 mtrr_chunk_size. 1505 1506 If unsure, say Y. 1507 1508config MTRR_SANITIZER_ENABLE_DEFAULT 1509 int "MTRR cleanup enable value (0-1)" 1510 range 0 1 1511 default "0" 1512 depends on MTRR_SANITIZER 1513 ---help--- 1514 Enable mtrr cleanup default value 1515 1516config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1517 int "MTRR cleanup spare reg num (0-7)" 1518 range 0 7 1519 default "1" 1520 depends on MTRR_SANITIZER 1521 ---help--- 1522 mtrr cleanup spare entries default, it can be changed via 1523 mtrr_spare_reg_nr=N on the kernel command line. 1524 1525config X86_PAT 1526 def_bool y 1527 prompt "x86 PAT support" if EXPERT 1528 depends on MTRR 1529 ---help--- 1530 Use PAT attributes to setup page level cache control. 1531 1532 PATs are the modern equivalents of MTRRs and are much more 1533 flexible than MTRRs. 1534 1535 Say N here if you see bootup problems (boot crash, boot hang, 1536 spontaneous reboots) or a non-working video driver. 1537 1538 If unsure, say Y. 1539 1540config ARCH_USES_PG_UNCACHED 1541 def_bool y 1542 depends on X86_PAT 1543 1544config ARCH_RANDOM 1545 def_bool y 1546 prompt "x86 architectural random number generator" if EXPERT 1547 ---help--- 1548 Enable the x86 architectural RDRAND instruction 1549 (Intel Bull Mountain technology) to generate random numbers. 1550 If supported, this is a high bandwidth, cryptographically 1551 secure hardware random number generator. 1552 1553config X86_SMAP 1554 def_bool y 1555 prompt "Supervisor Mode Access Prevention" if EXPERT 1556 ---help--- 1557 Supervisor Mode Access Prevention (SMAP) is a security 1558 feature in newer Intel processors. There is a small 1559 performance cost if this enabled and turned on; there is 1560 also a small increase in the kernel size if this is enabled. 1561 1562 If unsure, say Y. 1563 1564config EFI 1565 bool "EFI runtime service support" 1566 depends on ACPI 1567 select UCS2_STRING 1568 ---help--- 1569 This enables the kernel to use EFI runtime services that are 1570 available (such as the EFI variable services). 1571 1572 This option is only useful on systems that have EFI firmware. 1573 In addition, you should use the latest ELILO loader available 1574 at <http://elilo.sourceforge.net> in order to take advantage 1575 of EFI runtime services. However, even with this option, the 1576 resultant kernel should continue to boot on existing non-EFI 1577 platforms. 1578 1579config EFI_STUB 1580 bool "EFI stub support" 1581 depends on EFI 1582 ---help--- 1583 This kernel feature allows a bzImage to be loaded directly 1584 by EFI firmware without the use of a bootloader. 1585 1586 See Documentation/efi-stub.txt for more information. 1587 1588config SECCOMP 1589 def_bool y 1590 prompt "Enable seccomp to safely compute untrusted bytecode" 1591 ---help--- 1592 This kernel feature is useful for number crunching applications 1593 that may need to compute untrusted bytecode during their 1594 execution. By using pipes or other transports made available to 1595 the process as file descriptors supporting the read/write 1596 syscalls, it's possible to isolate those applications in 1597 their own address space using seccomp. Once seccomp is 1598 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1599 and the task is only allowed to execute a few safe syscalls 1600 defined by each seccomp mode. 1601 1602 If unsure, say Y. Only embedded should say N here. 1603 1604source kernel/Kconfig.hz 1605 1606config KEXEC 1607 bool "kexec system call" 1608 ---help--- 1609 kexec is a system call that implements the ability to shutdown your 1610 current kernel, and to start another kernel. It is like a reboot 1611 but it is independent of the system firmware. And like a reboot 1612 you can start any kernel with it, not just Linux. 1613 1614 The name comes from the similarity to the exec system call. 1615 1616 It is an ongoing process to be certain the hardware in a machine 1617 is properly shutdown, so do not be surprised if this code does not 1618 initially work for you. As of this writing the exact hardware 1619 interface is strongly in flux, so no good recommendation can be 1620 made. 1621 1622config CRASH_DUMP 1623 bool "kernel crash dumps" 1624 depends on X86_64 || (X86_32 && HIGHMEM) 1625 ---help--- 1626 Generate crash dump after being started by kexec. 1627 This should be normally only set in special crash dump kernels 1628 which are loaded in the main kernel with kexec-tools into 1629 a specially reserved region and then later executed after 1630 a crash by kdump/kexec. The crash dump kernel must be compiled 1631 to a memory address not used by the main kernel or BIOS using 1632 PHYSICAL_START, or it must be built as a relocatable image 1633 (CONFIG_RELOCATABLE=y). 1634 For more details see Documentation/kdump/kdump.txt 1635 1636config KEXEC_JUMP 1637 bool "kexec jump" 1638 depends on KEXEC && HIBERNATION 1639 ---help--- 1640 Jump between original kernel and kexeced kernel and invoke 1641 code in physical address mode via KEXEC 1642 1643config PHYSICAL_START 1644 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1645 default "0x1000000" 1646 ---help--- 1647 This gives the physical address where the kernel is loaded. 1648 1649 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1650 bzImage will decompress itself to above physical address and 1651 run from there. Otherwise, bzImage will run from the address where 1652 it has been loaded by the boot loader and will ignore above physical 1653 address. 1654 1655 In normal kdump cases one does not have to set/change this option 1656 as now bzImage can be compiled as a completely relocatable image 1657 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1658 address. This option is mainly useful for the folks who don't want 1659 to use a bzImage for capturing the crash dump and want to use a 1660 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1661 to be specifically compiled to run from a specific memory area 1662 (normally a reserved region) and this option comes handy. 1663 1664 So if you are using bzImage for capturing the crash dump, 1665 leave the value here unchanged to 0x1000000 and set 1666 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1667 for capturing the crash dump change this value to start of 1668 the reserved region. In other words, it can be set based on 1669 the "X" value as specified in the "crashkernel=YM@XM" 1670 command line boot parameter passed to the panic-ed 1671 kernel. Please take a look at Documentation/kdump/kdump.txt 1672 for more details about crash dumps. 1673 1674 Usage of bzImage for capturing the crash dump is recommended as 1675 one does not have to build two kernels. Same kernel can be used 1676 as production kernel and capture kernel. Above option should have 1677 gone away after relocatable bzImage support is introduced. But it 1678 is present because there are users out there who continue to use 1679 vmlinux for dump capture. This option should go away down the 1680 line. 1681 1682 Don't change this unless you know what you are doing. 1683 1684config RELOCATABLE 1685 bool "Build a relocatable kernel" 1686 default y 1687 ---help--- 1688 This builds a kernel image that retains relocation information 1689 so it can be loaded someplace besides the default 1MB. 1690 The relocations tend to make the kernel binary about 10% larger, 1691 but are discarded at runtime. 1692 1693 One use is for the kexec on panic case where the recovery kernel 1694 must live at a different physical address than the primary 1695 kernel. 1696 1697 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1698 it has been loaded at and the compile time physical address 1699 (CONFIG_PHYSICAL_START) is used as the minimum location. 1700 1701config RANDOMIZE_BASE 1702 bool "Randomize the address of the kernel image" 1703 depends on RELOCATABLE 1704 depends on !HIBERNATION 1705 default n 1706 ---help--- 1707 Randomizes the physical and virtual address at which the 1708 kernel image is decompressed, as a security feature that 1709 deters exploit attempts relying on knowledge of the location 1710 of kernel internals. 1711 1712 Entropy is generated using the RDRAND instruction if it is 1713 supported. If RDTSC is supported, it is used as well. If 1714 neither RDRAND nor RDTSC are supported, then randomness is 1715 read from the i8254 timer. 1716 1717 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1718 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1719 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1720 minimum of 2MiB, only 10 bits of entropy is theoretically 1721 possible. At best, due to page table layouts, 64-bit can use 1722 9 bits of entropy and 32-bit uses 8 bits. 1723 1724 If unsure, say N. 1725 1726config RANDOMIZE_BASE_MAX_OFFSET 1727 hex "Maximum kASLR offset allowed" if EXPERT 1728 depends on RANDOMIZE_BASE 1729 range 0x0 0x20000000 if X86_32 1730 default "0x20000000" if X86_32 1731 range 0x0 0x40000000 if X86_64 1732 default "0x40000000" if X86_64 1733 ---help--- 1734 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1735 memory is used to determine the maximal offset in bytes that will 1736 be applied to the kernel when kernel Address Space Layout 1737 Randomization (kASLR) is active. This must be a multiple of 1738 PHYSICAL_ALIGN. 1739 1740 On 32-bit this is limited to 512MiB by page table layouts. The 1741 default is 512MiB. 1742 1743 On 64-bit this is limited by how the kernel fixmap page table is 1744 positioned, so this cannot be larger than 1GiB currently. Without 1745 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1746 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1747 modules area will shrink to compensate, up to the current maximum 1748 1GiB to 1GiB split. The default is 1GiB. 1749 1750 If unsure, leave at the default value. 1751 1752# Relocation on x86 needs some additional build support 1753config X86_NEED_RELOCS 1754 def_bool y 1755 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1756 1757config PHYSICAL_ALIGN 1758 hex "Alignment value to which kernel should be aligned" 1759 default "0x200000" 1760 range 0x2000 0x1000000 if X86_32 1761 range 0x200000 0x1000000 if X86_64 1762 ---help--- 1763 This value puts the alignment restrictions on physical address 1764 where kernel is loaded and run from. Kernel is compiled for an 1765 address which meets above alignment restriction. 1766 1767 If bootloader loads the kernel at a non-aligned address and 1768 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1769 address aligned to above value and run from there. 1770 1771 If bootloader loads the kernel at a non-aligned address and 1772 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1773 load address and decompress itself to the address it has been 1774 compiled for and run from there. The address for which kernel is 1775 compiled already meets above alignment restrictions. Hence the 1776 end result is that kernel runs from a physical address meeting 1777 above alignment restrictions. 1778 1779 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1780 this value must be a multiple of 0x200000. 1781 1782 Don't change this unless you know what you are doing. 1783 1784config HOTPLUG_CPU 1785 bool "Support for hot-pluggable CPUs" 1786 depends on SMP 1787 ---help--- 1788 Say Y here to allow turning CPUs off and on. CPUs can be 1789 controlled through /sys/devices/system/cpu. 1790 ( Note: power management support will enable this option 1791 automatically on SMP systems. ) 1792 Say N if you want to disable CPU hotplug. 1793 1794config BOOTPARAM_HOTPLUG_CPU0 1795 bool "Set default setting of cpu0_hotpluggable" 1796 default n 1797 depends on HOTPLUG_CPU 1798 ---help--- 1799 Set whether default state of cpu0_hotpluggable is on or off. 1800 1801 Say Y here to enable CPU0 hotplug by default. If this switch 1802 is turned on, there is no need to give cpu0_hotplug kernel 1803 parameter and the CPU0 hotplug feature is enabled by default. 1804 1805 Please note: there are two known CPU0 dependencies if you want 1806 to enable the CPU0 hotplug feature either by this switch or by 1807 cpu0_hotplug kernel parameter. 1808 1809 First, resume from hibernate or suspend always starts from CPU0. 1810 So hibernate and suspend are prevented if CPU0 is offline. 1811 1812 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1813 offline if any interrupt can not migrate out of CPU0. There may 1814 be other CPU0 dependencies. 1815 1816 Please make sure the dependencies are under your control before 1817 you enable this feature. 1818 1819 Say N if you don't want to enable CPU0 hotplug feature by default. 1820 You still can enable the CPU0 hotplug feature at boot by kernel 1821 parameter cpu0_hotplug. 1822 1823config DEBUG_HOTPLUG_CPU0 1824 def_bool n 1825 prompt "Debug CPU0 hotplug" 1826 depends on HOTPLUG_CPU 1827 ---help--- 1828 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1829 soon as possible and boots up userspace with CPU0 offlined. User 1830 can online CPU0 back after boot time. 1831 1832 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1833 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1834 compilation or giving cpu0_hotplug kernel parameter at boot. 1835 1836 If unsure, say N. 1837 1838config COMPAT_VDSO 1839 def_bool y 1840 prompt "Compat VDSO support" 1841 depends on X86_32 || IA32_EMULATION 1842 ---help--- 1843 Map the 32-bit VDSO to the predictable old-style address too. 1844 1845 Say N here if you are running a sufficiently recent glibc 1846 version (2.3.3 or later), to remove the high-mapped 1847 VDSO mapping and to exclusively use the randomized VDSO. 1848 1849 If unsure, say Y. 1850 1851config CMDLINE_BOOL 1852 bool "Built-in kernel command line" 1853 ---help--- 1854 Allow for specifying boot arguments to the kernel at 1855 build time. On some systems (e.g. embedded ones), it is 1856 necessary or convenient to provide some or all of the 1857 kernel boot arguments with the kernel itself (that is, 1858 to not rely on the boot loader to provide them.) 1859 1860 To compile command line arguments into the kernel, 1861 set this option to 'Y', then fill in the 1862 the boot arguments in CONFIG_CMDLINE. 1863 1864 Systems with fully functional boot loaders (i.e. non-embedded) 1865 should leave this option set to 'N'. 1866 1867config CMDLINE 1868 string "Built-in kernel command string" 1869 depends on CMDLINE_BOOL 1870 default "" 1871 ---help--- 1872 Enter arguments here that should be compiled into the kernel 1873 image and used at boot time. If the boot loader provides a 1874 command line at boot time, it is appended to this string to 1875 form the full kernel command line, when the system boots. 1876 1877 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1878 change this behavior. 1879 1880 In most cases, the command line (whether built-in or provided 1881 by the boot loader) should specify the device for the root 1882 file system. 1883 1884config CMDLINE_OVERRIDE 1885 bool "Built-in command line overrides boot loader arguments" 1886 depends on CMDLINE_BOOL 1887 ---help--- 1888 Set this option to 'Y' to have the kernel ignore the boot loader 1889 command line, and use ONLY the built-in command line. 1890 1891 This is used to work around broken boot loaders. This should 1892 be set to 'N' under normal conditions. 1893 1894endmenu 1895 1896config ARCH_ENABLE_MEMORY_HOTPLUG 1897 def_bool y 1898 depends on X86_64 || (X86_32 && HIGHMEM) 1899 1900config ARCH_ENABLE_MEMORY_HOTREMOVE 1901 def_bool y 1902 depends on MEMORY_HOTPLUG 1903 1904config USE_PERCPU_NUMA_NODE_ID 1905 def_bool y 1906 depends on NUMA 1907 1908config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1909 def_bool y 1910 depends on X86_64 || X86_PAE 1911 1912menu "Power management and ACPI options" 1913 1914config ARCH_HIBERNATION_HEADER 1915 def_bool y 1916 depends on X86_64 && HIBERNATION 1917 1918source "kernel/power/Kconfig" 1919 1920source "drivers/acpi/Kconfig" 1921 1922source "drivers/sfi/Kconfig" 1923 1924config X86_APM_BOOT 1925 def_bool y 1926 depends on APM 1927 1928menuconfig APM 1929 tristate "APM (Advanced Power Management) BIOS support" 1930 depends on X86_32 && PM_SLEEP 1931 ---help--- 1932 APM is a BIOS specification for saving power using several different 1933 techniques. This is mostly useful for battery powered laptops with 1934 APM compliant BIOSes. If you say Y here, the system time will be 1935 reset after a RESUME operation, the /proc/apm device will provide 1936 battery status information, and user-space programs will receive 1937 notification of APM "events" (e.g. battery status change). 1938 1939 If you select "Y" here, you can disable actual use of the APM 1940 BIOS by passing the "apm=off" option to the kernel at boot time. 1941 1942 Note that the APM support is almost completely disabled for 1943 machines with more than one CPU. 1944 1945 In order to use APM, you will need supporting software. For location 1946 and more information, read <file:Documentation/power/apm-acpi.txt> 1947 and the Battery Powered Linux mini-HOWTO, available from 1948 <http://www.tldp.org/docs.html#howto>. 1949 1950 This driver does not spin down disk drives (see the hdparm(8) 1951 manpage ("man 8 hdparm") for that), and it doesn't turn off 1952 VESA-compliant "green" monitors. 1953 1954 This driver does not support the TI 4000M TravelMate and the ACER 1955 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1956 desktop machines also don't have compliant BIOSes, and this driver 1957 may cause those machines to panic during the boot phase. 1958 1959 Generally, if you don't have a battery in your machine, there isn't 1960 much point in using this driver and you should say N. If you get 1961 random kernel OOPSes or reboots that don't seem to be related to 1962 anything, try disabling/enabling this option (or disabling/enabling 1963 APM in your BIOS). 1964 1965 Some other things you should try when experiencing seemingly random, 1966 "weird" problems: 1967 1968 1) make sure that you have enough swap space and that it is 1969 enabled. 1970 2) pass the "no-hlt" option to the kernel 1971 3) switch on floating point emulation in the kernel and pass 1972 the "no387" option to the kernel 1973 4) pass the "floppy=nodma" option to the kernel 1974 5) pass the "mem=4M" option to the kernel (thereby disabling 1975 all but the first 4 MB of RAM) 1976 6) make sure that the CPU is not over clocked. 1977 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1978 8) disable the cache from your BIOS settings 1979 9) install a fan for the video card or exchange video RAM 1980 10) install a better fan for the CPU 1981 11) exchange RAM chips 1982 12) exchange the motherboard. 1983 1984 To compile this driver as a module, choose M here: the 1985 module will be called apm. 1986 1987if APM 1988 1989config APM_IGNORE_USER_SUSPEND 1990 bool "Ignore USER SUSPEND" 1991 ---help--- 1992 This option will ignore USER SUSPEND requests. On machines with a 1993 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1994 series notebooks, it is necessary to say Y because of a BIOS bug. 1995 1996config APM_DO_ENABLE 1997 bool "Enable PM at boot time" 1998 ---help--- 1999 Enable APM features at boot time. From page 36 of the APM BIOS 2000 specification: "When disabled, the APM BIOS does not automatically 2001 power manage devices, enter the Standby State, enter the Suspend 2002 State, or take power saving steps in response to CPU Idle calls." 2003 This driver will make CPU Idle calls when Linux is idle (unless this 2004 feature is turned off -- see "Do CPU IDLE calls", below). This 2005 should always save battery power, but more complicated APM features 2006 will be dependent on your BIOS implementation. You may need to turn 2007 this option off if your computer hangs at boot time when using APM 2008 support, or if it beeps continuously instead of suspending. Turn 2009 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2010 T400CDT. This is off by default since most machines do fine without 2011 this feature. 2012 2013config APM_CPU_IDLE 2014 depends on CPU_IDLE 2015 bool "Make CPU Idle calls when idle" 2016 ---help--- 2017 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2018 On some machines, this can activate improved power savings, such as 2019 a slowed CPU clock rate, when the machine is idle. These idle calls 2020 are made after the idle loop has run for some length of time (e.g., 2021 333 mS). On some machines, this will cause a hang at boot time or 2022 whenever the CPU becomes idle. (On machines with more than one CPU, 2023 this option does nothing.) 2024 2025config APM_DISPLAY_BLANK 2026 bool "Enable console blanking using APM" 2027 ---help--- 2028 Enable console blanking using the APM. Some laptops can use this to 2029 turn off the LCD backlight when the screen blanker of the Linux 2030 virtual console blanks the screen. Note that this is only used by 2031 the virtual console screen blanker, and won't turn off the backlight 2032 when using the X Window system. This also doesn't have anything to 2033 do with your VESA-compliant power-saving monitor. Further, this 2034 option doesn't work for all laptops -- it might not turn off your 2035 backlight at all, or it might print a lot of errors to the console, 2036 especially if you are using gpm. 2037 2038config APM_ALLOW_INTS 2039 bool "Allow interrupts during APM BIOS calls" 2040 ---help--- 2041 Normally we disable external interrupts while we are making calls to 2042 the APM BIOS as a measure to lessen the effects of a badly behaving 2043 BIOS implementation. The BIOS should reenable interrupts if it 2044 needs to. Unfortunately, some BIOSes do not -- especially those in 2045 many of the newer IBM Thinkpads. If you experience hangs when you 2046 suspend, try setting this to Y. Otherwise, say N. 2047 2048endif # APM 2049 2050source "drivers/cpufreq/Kconfig" 2051 2052source "drivers/cpuidle/Kconfig" 2053 2054source "drivers/idle/Kconfig" 2055 2056endmenu 2057 2058 2059menu "Bus options (PCI etc.)" 2060 2061config PCI 2062 bool "PCI support" 2063 default y 2064 ---help--- 2065 Find out whether you have a PCI motherboard. PCI is the name of a 2066 bus system, i.e. the way the CPU talks to the other stuff inside 2067 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2068 VESA. If you have PCI, say Y, otherwise N. 2069 2070choice 2071 prompt "PCI access mode" 2072 depends on X86_32 && PCI 2073 default PCI_GOANY 2074 ---help--- 2075 On PCI systems, the BIOS can be used to detect the PCI devices and 2076 determine their configuration. However, some old PCI motherboards 2077 have BIOS bugs and may crash if this is done. Also, some embedded 2078 PCI-based systems don't have any BIOS at all. Linux can also try to 2079 detect the PCI hardware directly without using the BIOS. 2080 2081 With this option, you can specify how Linux should detect the 2082 PCI devices. If you choose "BIOS", the BIOS will be used, 2083 if you choose "Direct", the BIOS won't be used, and if you 2084 choose "MMConfig", then PCI Express MMCONFIG will be used. 2085 If you choose "Any", the kernel will try MMCONFIG, then the 2086 direct access method and falls back to the BIOS if that doesn't 2087 work. If unsure, go with the default, which is "Any". 2088 2089config PCI_GOBIOS 2090 bool "BIOS" 2091 2092config PCI_GOMMCONFIG 2093 bool "MMConfig" 2094 2095config PCI_GODIRECT 2096 bool "Direct" 2097 2098config PCI_GOOLPC 2099 bool "OLPC XO-1" 2100 depends on OLPC 2101 2102config PCI_GOANY 2103 bool "Any" 2104 2105endchoice 2106 2107config PCI_BIOS 2108 def_bool y 2109 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2110 2111# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2112config PCI_DIRECT 2113 def_bool y 2114 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2115 2116config PCI_MMCONFIG 2117 def_bool y 2118 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2119 2120config PCI_OLPC 2121 def_bool y 2122 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2123 2124config PCI_XEN 2125 def_bool y 2126 depends on PCI && XEN 2127 select SWIOTLB_XEN 2128 2129config PCI_DOMAINS 2130 def_bool y 2131 depends on PCI 2132 2133config PCI_MMCONFIG 2134 bool "Support mmconfig PCI config space access" 2135 depends on X86_64 && PCI && ACPI 2136 2137config PCI_CNB20LE_QUIRK 2138 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2139 depends on PCI 2140 help 2141 Read the PCI windows out of the CNB20LE host bridge. This allows 2142 PCI hotplug to work on systems with the CNB20LE chipset which do 2143 not have ACPI. 2144 2145 There's no public spec for this chipset, and this functionality 2146 is known to be incomplete. 2147 2148 You should say N unless you know you need this. 2149 2150source "drivers/pci/pcie/Kconfig" 2151 2152source "drivers/pci/Kconfig" 2153 2154# x86_64 have no ISA slots, but can have ISA-style DMA. 2155config ISA_DMA_API 2156 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2157 default y 2158 help 2159 Enables ISA-style DMA support for devices requiring such controllers. 2160 If unsure, say Y. 2161 2162if X86_32 2163 2164config ISA 2165 bool "ISA support" 2166 ---help--- 2167 Find out whether you have ISA slots on your motherboard. ISA is the 2168 name of a bus system, i.e. the way the CPU talks to the other stuff 2169 inside your box. Other bus systems are PCI, EISA, MicroChannel 2170 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2171 newer boards don't support it. If you have ISA, say Y, otherwise N. 2172 2173config EISA 2174 bool "EISA support" 2175 depends on ISA 2176 ---help--- 2177 The Extended Industry Standard Architecture (EISA) bus was 2178 developed as an open alternative to the IBM MicroChannel bus. 2179 2180 The EISA bus provided some of the features of the IBM MicroChannel 2181 bus while maintaining backward compatibility with cards made for 2182 the older ISA bus. The EISA bus saw limited use between 1988 and 2183 1995 when it was made obsolete by the PCI bus. 2184 2185 Say Y here if you are building a kernel for an EISA-based machine. 2186 2187 Otherwise, say N. 2188 2189source "drivers/eisa/Kconfig" 2190 2191config SCx200 2192 tristate "NatSemi SCx200 support" 2193 ---help--- 2194 This provides basic support for National Semiconductor's 2195 (now AMD's) Geode processors. The driver probes for the 2196 PCI-IDs of several on-chip devices, so its a good dependency 2197 for other scx200_* drivers. 2198 2199 If compiled as a module, the driver is named scx200. 2200 2201config SCx200HR_TIMER 2202 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2203 depends on SCx200 2204 default y 2205 ---help--- 2206 This driver provides a clocksource built upon the on-chip 2207 27MHz high-resolution timer. Its also a workaround for 2208 NSC Geode SC-1100's buggy TSC, which loses time when the 2209 processor goes idle (as is done by the scheduler). The 2210 other workaround is idle=poll boot option. 2211 2212config OLPC 2213 bool "One Laptop Per Child support" 2214 depends on !X86_PAE 2215 select GPIOLIB 2216 select OF 2217 select OF_PROMTREE 2218 select IRQ_DOMAIN 2219 ---help--- 2220 Add support for detecting the unique features of the OLPC 2221 XO hardware. 2222 2223config OLPC_XO1_PM 2224 bool "OLPC XO-1 Power Management" 2225 depends on OLPC && MFD_CS5535 && PM_SLEEP 2226 select MFD_CORE 2227 ---help--- 2228 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2229 2230config OLPC_XO1_RTC 2231 bool "OLPC XO-1 Real Time Clock" 2232 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2233 ---help--- 2234 Add support for the XO-1 real time clock, which can be used as a 2235 programmable wakeup source. 2236 2237config OLPC_XO1_SCI 2238 bool "OLPC XO-1 SCI extras" 2239 depends on OLPC && OLPC_XO1_PM 2240 depends on INPUT=y 2241 select POWER_SUPPLY 2242 select GPIO_CS5535 2243 select MFD_CORE 2244 ---help--- 2245 Add support for SCI-based features of the OLPC XO-1 laptop: 2246 - EC-driven system wakeups 2247 - Power button 2248 - Ebook switch 2249 - Lid switch 2250 - AC adapter status updates 2251 - Battery status updates 2252 2253config OLPC_XO15_SCI 2254 bool "OLPC XO-1.5 SCI extras" 2255 depends on OLPC && ACPI 2256 select POWER_SUPPLY 2257 ---help--- 2258 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2259 - EC-driven system wakeups 2260 - AC adapter status updates 2261 - Battery status updates 2262 2263config ALIX 2264 bool "PCEngines ALIX System Support (LED setup)" 2265 select GPIOLIB 2266 ---help--- 2267 This option enables system support for the PCEngines ALIX. 2268 At present this just sets up LEDs for GPIO control on 2269 ALIX2/3/6 boards. However, other system specific setup should 2270 get added here. 2271 2272 Note: You must still enable the drivers for GPIO and LED support 2273 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2274 2275 Note: You have to set alix.force=1 for boards with Award BIOS. 2276 2277config NET5501 2278 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2279 select GPIOLIB 2280 ---help--- 2281 This option enables system support for the Soekris Engineering net5501. 2282 2283config GEOS 2284 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2285 select GPIOLIB 2286 depends on DMI 2287 ---help--- 2288 This option enables system support for the Traverse Technologies GEOS. 2289 2290config TS5500 2291 bool "Technologic Systems TS-5500 platform support" 2292 depends on MELAN 2293 select CHECK_SIGNATURE 2294 select NEW_LEDS 2295 select LEDS_CLASS 2296 ---help--- 2297 This option enables system support for the Technologic Systems TS-5500. 2298 2299endif # X86_32 2300 2301config AMD_NB 2302 def_bool y 2303 depends on CPU_SUP_AMD && PCI 2304 2305source "drivers/pcmcia/Kconfig" 2306 2307source "drivers/pci/hotplug/Kconfig" 2308 2309config RAPIDIO 2310 tristate "RapidIO support" 2311 depends on PCI 2312 default n 2313 help 2314 If enabled this option will include drivers and the core 2315 infrastructure code to support RapidIO interconnect devices. 2316 2317source "drivers/rapidio/Kconfig" 2318 2319config X86_SYSFB 2320 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2321 help 2322 Firmwares often provide initial graphics framebuffers so the BIOS, 2323 bootloader or kernel can show basic video-output during boot for 2324 user-guidance and debugging. Historically, x86 used the VESA BIOS 2325 Extensions and EFI-framebuffers for this, which are mostly limited 2326 to x86. 2327 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2328 framebuffers so the new generic system-framebuffer drivers can be 2329 used on x86. If the framebuffer is not compatible with the generic 2330 modes, it is adverticed as fallback platform framebuffer so legacy 2331 drivers like efifb, vesafb and uvesafb can pick it up. 2332 If this option is not selected, all system framebuffers are always 2333 marked as fallback platform framebuffers as usual. 2334 2335 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2336 not be able to pick up generic system framebuffers if this option 2337 is selected. You are highly encouraged to enable simplefb as 2338 replacement if you select this option. simplefb can correctly deal 2339 with generic system framebuffers. But you should still keep vesafb 2340 and others enabled as fallback if a system framebuffer is 2341 incompatible with simplefb. 2342 2343 If unsure, say Y. 2344 2345endmenu 2346 2347 2348menu "Executable file formats / Emulations" 2349 2350source "fs/Kconfig.binfmt" 2351 2352config IA32_EMULATION 2353 bool "IA32 Emulation" 2354 depends on X86_64 2355 select BINFMT_ELF 2356 select COMPAT_BINFMT_ELF 2357 select HAVE_UID16 2358 ---help--- 2359 Include code to run legacy 32-bit programs under a 2360 64-bit kernel. You should likely turn this on, unless you're 2361 100% sure that you don't have any 32-bit programs left. 2362 2363config IA32_AOUT 2364 tristate "IA32 a.out support" 2365 depends on IA32_EMULATION 2366 ---help--- 2367 Support old a.out binaries in the 32bit emulation. 2368 2369config X86_X32 2370 bool "x32 ABI for 64-bit mode" 2371 depends on X86_64 && IA32_EMULATION 2372 ---help--- 2373 Include code to run binaries for the x32 native 32-bit ABI 2374 for 64-bit processors. An x32 process gets access to the 2375 full 64-bit register file and wide data path while leaving 2376 pointers at 32 bits for smaller memory footprint. 2377 2378 You will need a recent binutils (2.22 or later) with 2379 elf32_x86_64 support enabled to compile a kernel with this 2380 option set. 2381 2382config COMPAT 2383 def_bool y 2384 depends on IA32_EMULATION || X86_X32 2385 select ARCH_WANT_OLD_COMPAT_IPC 2386 2387if COMPAT 2388config COMPAT_FOR_U64_ALIGNMENT 2389 def_bool y 2390 2391config SYSVIPC_COMPAT 2392 def_bool y 2393 depends on SYSVIPC 2394 2395config KEYS_COMPAT 2396 def_bool y 2397 depends on KEYS 2398endif 2399 2400endmenu 2401 2402 2403config HAVE_ATOMIC_IOMAP 2404 def_bool y 2405 depends on X86_32 2406 2407config X86_DEV_DMA_OPS 2408 bool 2409 depends on X86_64 || STA2X11 2410 2411config X86_DMA_REMAP 2412 bool 2413 depends on STA2X11 2414 2415config IOSF_MBI 2416 bool 2417 depends on PCI 2418 ---help--- 2419 To be selected by modules requiring access to the Intel OnChip System 2420 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms 2421 enumerable by PCI. 2422 2423source "net/Kconfig" 2424 2425source "drivers/Kconfig" 2426 2427source "drivers/firmware/Kconfig" 2428 2429source "fs/Kconfig" 2430 2431source "arch/x86/Kconfig.debug" 2432 2433source "security/Kconfig" 2434 2435source "crypto/Kconfig" 2436 2437source "arch/x86/kvm/Kconfig" 2438 2439source "lib/Kconfig" 2440