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