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_MIGHT_HAVE_ACPI_PDC if ACPI 25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 26 select ARCH_HAS_FAST_MULTIPLIER 27 select ARCH_HAS_GCOV_PROFILE_ALL 28 select ARCH_MIGHT_HAVE_PC_PARPORT 29 select ARCH_MIGHT_HAVE_PC_SERIO 30 select HAVE_AOUT if X86_32 31 select HAVE_UNSTABLE_SCHED_CLOCK 32 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 33 select ARCH_SUPPORTS_INT128 if X86_64 34 select HAVE_IDE 35 select HAVE_OPROFILE 36 select HAVE_PCSPKR_PLATFORM 37 select HAVE_PERF_EVENTS 38 select HAVE_IOREMAP_PROT 39 select HAVE_KPROBES 40 select HAVE_MEMBLOCK 41 select HAVE_MEMBLOCK_NODE_MAP 42 select ARCH_DISCARD_MEMBLOCK 43 select ARCH_WANT_OPTIONAL_GPIOLIB 44 select ARCH_WANT_FRAME_POINTERS 45 select HAVE_DMA_ATTRS 46 select HAVE_DMA_CONTIGUOUS 47 select HAVE_KRETPROBES 48 select GENERIC_EARLY_IOREMAP 49 select HAVE_OPTPROBES 50 select HAVE_KPROBES_ON_FTRACE 51 select HAVE_FTRACE_MCOUNT_RECORD 52 select HAVE_FENTRY if X86_64 53 select HAVE_C_RECORDMCOUNT 54 select HAVE_DYNAMIC_FTRACE 55 select HAVE_DYNAMIC_FTRACE_WITH_REGS 56 select HAVE_FUNCTION_TRACER 57 select HAVE_FUNCTION_GRAPH_TRACER 58 select HAVE_FUNCTION_GRAPH_FP_TEST 59 select HAVE_SYSCALL_TRACEPOINTS 60 select SYSCTL_EXCEPTION_TRACE 61 select HAVE_KVM 62 select HAVE_ARCH_KGDB 63 select HAVE_ARCH_TRACEHOOK 64 select HAVE_GENERIC_DMA_COHERENT if X86_32 65 select HAVE_EFFICIENT_UNALIGNED_ACCESS 66 select USER_STACKTRACE_SUPPORT 67 select HAVE_REGS_AND_STACK_ACCESS_API 68 select HAVE_DMA_API_DEBUG 69 select HAVE_KERNEL_GZIP 70 select HAVE_KERNEL_BZIP2 71 select HAVE_KERNEL_LZMA 72 select HAVE_KERNEL_XZ 73 select HAVE_KERNEL_LZO 74 select HAVE_KERNEL_LZ4 75 select HAVE_HW_BREAKPOINT 76 select HAVE_MIXED_BREAKPOINTS_REGS 77 select PERF_EVENTS 78 select HAVE_PERF_EVENTS_NMI 79 select HAVE_PERF_REGS 80 select HAVE_PERF_USER_STACK_DUMP 81 select HAVE_DEBUG_KMEMLEAK 82 select ANON_INODES 83 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 84 select HAVE_CMPXCHG_LOCAL 85 select HAVE_CMPXCHG_DOUBLE 86 select HAVE_ARCH_KMEMCHECK 87 select HAVE_USER_RETURN_NOTIFIER 88 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 89 select HAVE_ARCH_JUMP_LABEL 90 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 91 select SPARSE_IRQ 92 select GENERIC_FIND_FIRST_BIT 93 select GENERIC_IRQ_PROBE 94 select GENERIC_PENDING_IRQ if SMP 95 select GENERIC_IRQ_SHOW 96 select GENERIC_CLOCKEVENTS_MIN_ADJUST 97 select IRQ_FORCED_THREADING 98 select HAVE_BPF_JIT if X86_64 99 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 100 select ARCH_HAS_SG_CHAIN 101 select CLKEVT_I8253 102 select ARCH_HAVE_NMI_SAFE_CMPXCHG 103 select GENERIC_IOMAP 104 select DCACHE_WORD_ACCESS 105 select GENERIC_SMP_IDLE_THREAD 106 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 107 select HAVE_ARCH_SECCOMP_FILTER 108 select BUILDTIME_EXTABLE_SORT 109 select GENERIC_CMOS_UPDATE 110 select HAVE_ARCH_SOFT_DIRTY if X86_64 111 select CLOCKSOURCE_WATCHDOG 112 select GENERIC_CLOCKEVENTS 113 select ARCH_CLOCKSOURCE_DATA 114 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 115 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 116 select GENERIC_TIME_VSYSCALL 117 select GENERIC_STRNCPY_FROM_USER 118 select GENERIC_STRNLEN_USER 119 select HAVE_CONTEXT_TRACKING if X86_64 120 select HAVE_IRQ_TIME_ACCOUNTING 121 select VIRT_TO_BUS 122 select MODULES_USE_ELF_REL if X86_32 123 select MODULES_USE_ELF_RELA if X86_64 124 select CLONE_BACKWARDS if X86_32 125 select ARCH_USE_BUILTIN_BSWAP 126 select ARCH_USE_QUEUE_RWLOCK 127 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 128 select OLD_SIGACTION if X86_32 129 select COMPAT_OLD_SIGACTION if IA32_EMULATION 130 select RTC_LIB 131 select HAVE_DEBUG_STACKOVERFLOW 132 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 133 select HAVE_CC_STACKPROTECTOR 134 select GENERIC_CPU_AUTOPROBE 135 select HAVE_ARCH_AUDITSYSCALL 136 select ARCH_SUPPORTS_ATOMIC_RMW 137 select HAVE_ACPI_APEI if ACPI 138 select HAVE_ACPI_APEI_NMI if ACPI 139 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 140 select X86_FEATURE_NAMES if PROC_FS 141 142config INSTRUCTION_DECODER 143 def_bool y 144 depends on KPROBES || PERF_EVENTS || UPROBES 145 146config PERF_EVENTS_INTEL_UNCORE 147 def_bool y 148 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 149 150config OUTPUT_FORMAT 151 string 152 default "elf32-i386" if X86_32 153 default "elf64-x86-64" if X86_64 154 155config ARCH_DEFCONFIG 156 string 157 default "arch/x86/configs/i386_defconfig" if X86_32 158 default "arch/x86/configs/x86_64_defconfig" if X86_64 159 160config LOCKDEP_SUPPORT 161 def_bool y 162 163config STACKTRACE_SUPPORT 164 def_bool y 165 166config HAVE_LATENCYTOP_SUPPORT 167 def_bool y 168 169config MMU 170 def_bool y 171 172config SBUS 173 bool 174 175config NEED_DMA_MAP_STATE 176 def_bool y 177 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 178 179config NEED_SG_DMA_LENGTH 180 def_bool y 181 182config GENERIC_ISA_DMA 183 def_bool y 184 depends on ISA_DMA_API 185 186config GENERIC_BUG 187 def_bool y 188 depends on BUG 189 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 190 191config GENERIC_BUG_RELATIVE_POINTERS 192 bool 193 194config GENERIC_HWEIGHT 195 def_bool y 196 197config ARCH_MAY_HAVE_PC_FDC 198 def_bool y 199 depends on ISA_DMA_API 200 201config RWSEM_XCHGADD_ALGORITHM 202 def_bool y 203 204config GENERIC_CALIBRATE_DELAY 205 def_bool y 206 207config ARCH_HAS_CPU_RELAX 208 def_bool y 209 210config ARCH_HAS_CACHE_LINE_SIZE 211 def_bool y 212 213config HAVE_SETUP_PER_CPU_AREA 214 def_bool y 215 216config NEED_PER_CPU_EMBED_FIRST_CHUNK 217 def_bool y 218 219config NEED_PER_CPU_PAGE_FIRST_CHUNK 220 def_bool y 221 222config ARCH_HIBERNATION_POSSIBLE 223 def_bool y 224 225config ARCH_SUSPEND_POSSIBLE 226 def_bool y 227 228config ARCH_WANT_HUGE_PMD_SHARE 229 def_bool y 230 231config ARCH_WANT_GENERAL_HUGETLB 232 def_bool y 233 234config ZONE_DMA32 235 bool 236 default X86_64 237 238config AUDIT_ARCH 239 bool 240 default X86_64 241 242config ARCH_SUPPORTS_OPTIMIZED_INLINING 243 def_bool y 244 245config ARCH_SUPPORTS_DEBUG_PAGEALLOC 246 def_bool y 247 248config HAVE_INTEL_TXT 249 def_bool y 250 depends on INTEL_IOMMU && ACPI 251 252config X86_INTEL_MPX 253 def_bool y 254 depends on CPU_SUP_INTEL 255 256config X86_32_SMP 257 def_bool y 258 depends on X86_32 && SMP 259 260config X86_64_SMP 261 def_bool y 262 depends on X86_64 && SMP 263 264config X86_HT 265 def_bool y 266 depends on SMP 267 268config X86_32_LAZY_GS 269 def_bool y 270 depends on X86_32 && !CC_STACKPROTECTOR 271 272config ARCH_HWEIGHT_CFLAGS 273 string 274 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 275 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_64 276 277config ARCH_SUPPORTS_UPROBES 278 def_bool y 279 280config FIX_EARLYCON_MEM 281 def_bool y 282 283source "init/Kconfig" 284source "kernel/Kconfig.freezer" 285 286menu "Processor type and features" 287 288config ZONE_DMA 289 bool "DMA memory allocation support" if EXPERT 290 default y 291 help 292 DMA memory allocation support allows devices with less than 32-bit 293 addressing to allocate within the first 16MB of address space. 294 Disable if no such devices will be used. 295 296 If unsure, say Y. 297 298config SMP 299 bool "Symmetric multi-processing support" 300 ---help--- 301 This enables support for systems with more than one CPU. If you have 302 a system with only one CPU, say N. If you have a system with more 303 than one CPU, say Y. 304 305 If you say N here, the kernel will run on uni- and multiprocessor 306 machines, but will use only one CPU of a multiprocessor machine. If 307 you say Y here, the kernel will run on many, but not all, 308 uniprocessor machines. On a uniprocessor machine, the kernel 309 will run faster if you say N here. 310 311 Note that if you say Y here and choose architecture "586" or 312 "Pentium" under "Processor family", the kernel will not work on 486 313 architectures. Similarly, multiprocessor kernels for the "PPro" 314 architecture may not work on all Pentium based boards. 315 316 People using multiprocessor machines who say Y here should also say 317 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 318 Management" code will be disabled if you say Y here. 319 320 See also <file:Documentation/x86/i386/IO-APIC.txt>, 321 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 322 <http://www.tldp.org/docs.html#howto>. 323 324 If you don't know what to do here, say N. 325 326config X86_FEATURE_NAMES 327 bool "Processor feature human-readable names" if EMBEDDED 328 default y 329 ---help--- 330 This option compiles in a table of x86 feature bits and corresponding 331 names. This is required to support /proc/cpuinfo and a few kernel 332 messages. You can disable this to save space, at the expense of 333 making those few kernel messages show numeric feature bits instead. 334 335 If in doubt, say Y. 336 337config X86_X2APIC 338 bool "Support x2apic" 339 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 340 ---help--- 341 This enables x2apic support on CPUs that have this feature. 342 343 This allows 32-bit apic IDs (so it can support very large systems), 344 and accesses the local apic via MSRs not via mmio. 345 346 If you don't know what to do here, say N. 347 348config X86_MPPARSE 349 bool "Enable MPS table" if ACPI || SFI 350 default y 351 depends on X86_LOCAL_APIC 352 ---help--- 353 For old smp systems that do not have proper acpi support. Newer systems 354 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 355 356config X86_BIGSMP 357 bool "Support for big SMP systems with more than 8 CPUs" 358 depends on X86_32 && SMP 359 ---help--- 360 This option is needed for the systems that have more than 8 CPUs 361 362config GOLDFISH 363 def_bool y 364 depends on X86_GOLDFISH 365 366if X86_32 367config X86_EXTENDED_PLATFORM 368 bool "Support for extended (non-PC) x86 platforms" 369 default y 370 ---help--- 371 If you disable this option then the kernel will only support 372 standard PC platforms. (which covers the vast majority of 373 systems out there.) 374 375 If you enable this option then you'll be able to select support 376 for the following (non-PC) 32 bit x86 platforms: 377 Goldfish (Android emulator) 378 AMD Elan 379 RDC R-321x SoC 380 SGI 320/540 (Visual Workstation) 381 STA2X11-based (e.g. Northville) 382 Moorestown MID devices 383 384 If you have one of these systems, or if you want to build a 385 generic distribution kernel, say Y here - otherwise say N. 386endif 387 388if X86_64 389config X86_EXTENDED_PLATFORM 390 bool "Support for extended (non-PC) x86 platforms" 391 default y 392 ---help--- 393 If you disable this option then the kernel will only support 394 standard PC platforms. (which covers the vast majority of 395 systems out there.) 396 397 If you enable this option then you'll be able to select support 398 for the following (non-PC) 64 bit x86 platforms: 399 Numascale NumaChip 400 ScaleMP vSMP 401 SGI Ultraviolet 402 403 If you have one of these systems, or if you want to build a 404 generic distribution kernel, say Y here - otherwise say N. 405endif 406# This is an alphabetically sorted list of 64 bit extended platforms 407# Please maintain the alphabetic order if and when there are additions 408config X86_NUMACHIP 409 bool "Numascale NumaChip" 410 depends on X86_64 411 depends on X86_EXTENDED_PLATFORM 412 depends on NUMA 413 depends on SMP 414 depends on X86_X2APIC 415 depends on PCI_MMCONFIG 416 ---help--- 417 Adds support for Numascale NumaChip large-SMP systems. Needed to 418 enable more than ~168 cores. 419 If you don't have one of these, you should say N here. 420 421config X86_VSMP 422 bool "ScaleMP vSMP" 423 select HYPERVISOR_GUEST 424 select PARAVIRT 425 depends on X86_64 && PCI 426 depends on X86_EXTENDED_PLATFORM 427 depends on SMP 428 ---help--- 429 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 430 supposed to run on these EM64T-based machines. Only choose this option 431 if you have one of these machines. 432 433config X86_UV 434 bool "SGI Ultraviolet" 435 depends on X86_64 436 depends on X86_EXTENDED_PLATFORM 437 depends on NUMA 438 depends on X86_X2APIC 439 ---help--- 440 This option is needed in order to support SGI Ultraviolet systems. 441 If you don't have one of these, you should say N here. 442 443# Following is an alphabetically sorted list of 32 bit extended platforms 444# Please maintain the alphabetic order if and when there are additions 445 446config X86_GOLDFISH 447 bool "Goldfish (Virtual Platform)" 448 depends on X86_EXTENDED_PLATFORM 449 ---help--- 450 Enable support for the Goldfish virtual platform used primarily 451 for Android development. Unless you are building for the Android 452 Goldfish emulator say N here. 453 454config X86_INTEL_CE 455 bool "CE4100 TV platform" 456 depends on PCI 457 depends on PCI_GODIRECT 458 depends on X86_IO_APIC 459 depends on X86_32 460 depends on X86_EXTENDED_PLATFORM 461 select X86_REBOOTFIXUPS 462 select OF 463 select OF_EARLY_FLATTREE 464 select IRQ_DOMAIN 465 ---help--- 466 Select for the Intel CE media processor (CE4100) SOC. 467 This option compiles in support for the CE4100 SOC for settop 468 boxes and media devices. 469 470config X86_INTEL_MID 471 bool "Intel MID platform support" 472 depends on X86_32 473 depends on X86_EXTENDED_PLATFORM 474 depends on X86_PLATFORM_DEVICES 475 depends on PCI 476 depends on PCI_GOANY 477 depends on X86_IO_APIC 478 select SFI 479 select I2C 480 select DW_APB_TIMER 481 select APB_TIMER 482 select INTEL_SCU_IPC 483 select MFD_INTEL_MSIC 484 ---help--- 485 Select to build a kernel capable of supporting Intel MID (Mobile 486 Internet Device) platform systems which do not have the PCI legacy 487 interfaces. If you are building for a PC class system say N here. 488 489 Intel MID platforms are based on an Intel processor and chipset which 490 consume less power than most of the x86 derivatives. 491 492config X86_INTEL_LPSS 493 bool "Intel Low Power Subsystem Support" 494 depends on ACPI 495 select COMMON_CLK 496 select PINCTRL 497 ---help--- 498 Select to build support for Intel Low Power Subsystem such as 499 found on Intel Lynxpoint PCH. Selecting this option enables 500 things like clock tree (common clock framework) and pincontrol 501 which are needed by the LPSS peripheral drivers. 502 503config IOSF_MBI 504 tristate "Intel SoC IOSF Sideband support for SoC platforms" 505 depends on PCI 506 ---help--- 507 This option enables sideband register access support for Intel SoC 508 platforms. On these platforms the IOSF sideband is used in lieu of 509 MSR's for some register accesses, mostly but not limited to thermal 510 and power. Drivers may query the availability of this device to 511 determine if they need the sideband in order to work on these 512 platforms. The sideband is available on the following SoC products. 513 This list is not meant to be exclusive. 514 - BayTrail 515 - Braswell 516 - Quark 517 518 You should say Y if you are running a kernel on one of these SoC's. 519 520config IOSF_MBI_DEBUG 521 bool "Enable IOSF sideband access through debugfs" 522 depends on IOSF_MBI && DEBUG_FS 523 ---help--- 524 Select this option to expose the IOSF sideband access registers (MCR, 525 MDR, MCRX) through debugfs to write and read register information from 526 different units on the SoC. This is most useful for obtaining device 527 state information for debug and analysis. As this is a general access 528 mechanism, users of this option would have specific knowledge of the 529 device they want to access. 530 531 If you don't require the option or are in doubt, say N. 532 533config X86_RDC321X 534 bool "RDC R-321x SoC" 535 depends on X86_32 536 depends on X86_EXTENDED_PLATFORM 537 select M486 538 select X86_REBOOTFIXUPS 539 ---help--- 540 This option is needed for RDC R-321x system-on-chip, also known 541 as R-8610-(G). 542 If you don't have one of these chips, you should say N here. 543 544config X86_32_NON_STANDARD 545 bool "Support non-standard 32-bit SMP architectures" 546 depends on X86_32 && SMP 547 depends on X86_EXTENDED_PLATFORM 548 ---help--- 549 This option compiles in the bigsmp and STA2X11 default 550 subarchitectures. It is intended for a generic binary 551 kernel. If you select them all, kernel will probe it one by 552 one and will fallback to default. 553 554# Alphabetically sorted list of Non standard 32 bit platforms 555 556config X86_SUPPORTS_MEMORY_FAILURE 557 def_bool y 558 # MCE code calls memory_failure(): 559 depends on X86_MCE 560 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 561 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 562 depends on X86_64 || !SPARSEMEM 563 select ARCH_SUPPORTS_MEMORY_FAILURE 564 565config STA2X11 566 bool "STA2X11 Companion Chip Support" 567 depends on X86_32_NON_STANDARD && PCI 568 select X86_DEV_DMA_OPS 569 select X86_DMA_REMAP 570 select SWIOTLB 571 select MFD_STA2X11 572 select ARCH_REQUIRE_GPIOLIB 573 default n 574 ---help--- 575 This adds support for boards based on the STA2X11 IO-Hub, 576 a.k.a. "ConneXt". The chip is used in place of the standard 577 PC chipset, so all "standard" peripherals are missing. If this 578 option is selected the kernel will still be able to boot on 579 standard PC machines. 580 581config X86_32_IRIS 582 tristate "Eurobraille/Iris poweroff module" 583 depends on X86_32 584 ---help--- 585 The Iris machines from EuroBraille do not have APM or ACPI support 586 to shut themselves down properly. A special I/O sequence is 587 needed to do so, which is what this module does at 588 kernel shutdown. 589 590 This is only for Iris machines from EuroBraille. 591 592 If unused, say N. 593 594config SCHED_OMIT_FRAME_POINTER 595 def_bool y 596 prompt "Single-depth WCHAN output" 597 depends on X86 598 ---help--- 599 Calculate simpler /proc/<PID>/wchan values. If this option 600 is disabled then wchan values will recurse back to the 601 caller function. This provides more accurate wchan values, 602 at the expense of slightly more scheduling overhead. 603 604 If in doubt, say "Y". 605 606menuconfig HYPERVISOR_GUEST 607 bool "Linux guest support" 608 ---help--- 609 Say Y here to enable options for running Linux under various hyper- 610 visors. This option enables basic hypervisor detection and platform 611 setup. 612 613 If you say N, all options in this submenu will be skipped and 614 disabled, and Linux guest support won't be built in. 615 616if HYPERVISOR_GUEST 617 618config PARAVIRT 619 bool "Enable paravirtualization code" 620 ---help--- 621 This changes the kernel so it can modify itself when it is run 622 under a hypervisor, potentially improving performance significantly 623 over full virtualization. However, when run without a hypervisor 624 the kernel is theoretically slower and slightly larger. 625 626config PARAVIRT_DEBUG 627 bool "paravirt-ops debugging" 628 depends on PARAVIRT && DEBUG_KERNEL 629 ---help--- 630 Enable to debug paravirt_ops internals. Specifically, BUG if 631 a paravirt_op is missing when it is called. 632 633config PARAVIRT_SPINLOCKS 634 bool "Paravirtualization layer for spinlocks" 635 depends on PARAVIRT && SMP 636 select UNINLINE_SPIN_UNLOCK 637 ---help--- 638 Paravirtualized spinlocks allow a pvops backend to replace the 639 spinlock implementation with something virtualization-friendly 640 (for example, block the virtual CPU rather than spinning). 641 642 It has a minimal impact on native kernels and gives a nice performance 643 benefit on paravirtualized KVM / Xen kernels. 644 645 If you are unsure how to answer this question, answer Y. 646 647source "arch/x86/xen/Kconfig" 648 649config KVM_GUEST 650 bool "KVM Guest support (including kvmclock)" 651 depends on PARAVIRT 652 select PARAVIRT_CLOCK 653 default y 654 ---help--- 655 This option enables various optimizations for running under the KVM 656 hypervisor. It includes a paravirtualized clock, so that instead 657 of relying on a PIT (or probably other) emulation by the 658 underlying device model, the host provides the guest with 659 timing infrastructure such as time of day, and system time 660 661config KVM_DEBUG_FS 662 bool "Enable debug information for KVM Guests in debugfs" 663 depends on KVM_GUEST && DEBUG_FS 664 default n 665 ---help--- 666 This option enables collection of various statistics for KVM guest. 667 Statistics are displayed in debugfs filesystem. Enabling this option 668 may incur significant overhead. 669 670source "arch/x86/lguest/Kconfig" 671 672config PARAVIRT_TIME_ACCOUNTING 673 bool "Paravirtual steal time accounting" 674 depends on PARAVIRT 675 default n 676 ---help--- 677 Select this option to enable fine granularity task steal time 678 accounting. Time spent executing other tasks in parallel with 679 the current vCPU is discounted from the vCPU power. To account for 680 that, there can be a small performance impact. 681 682 If in doubt, say N here. 683 684config PARAVIRT_CLOCK 685 bool 686 687endif #HYPERVISOR_GUEST 688 689config NO_BOOTMEM 690 def_bool y 691 692config MEMTEST 693 bool "Memtest" 694 ---help--- 695 This option adds a kernel parameter 'memtest', which allows memtest 696 to be set. 697 memtest=0, mean disabled; -- default 698 memtest=1, mean do 1 test pattern; 699 ... 700 memtest=4, mean do 4 test patterns. 701 If you are unsure how to answer this question, answer N. 702 703source "arch/x86/Kconfig.cpu" 704 705config HPET_TIMER 706 def_bool X86_64 707 prompt "HPET Timer Support" if X86_32 708 ---help--- 709 Use the IA-PC HPET (High Precision Event Timer) to manage 710 time in preference to the PIT and RTC, if a HPET is 711 present. 712 HPET is the next generation timer replacing legacy 8254s. 713 The HPET provides a stable time base on SMP 714 systems, unlike the TSC, but it is more expensive to access, 715 as it is off-chip. You can find the HPET spec at 716 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 717 718 You can safely choose Y here. However, HPET will only be 719 activated if the platform and the BIOS support this feature. 720 Otherwise the 8254 will be used for timing services. 721 722 Choose N to continue using the legacy 8254 timer. 723 724config HPET_EMULATE_RTC 725 def_bool y 726 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 727 728config APB_TIMER 729 def_bool y if X86_INTEL_MID 730 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 731 select DW_APB_TIMER 732 depends on X86_INTEL_MID && SFI 733 help 734 APB timer is the replacement for 8254, HPET on X86 MID platforms. 735 The APBT provides a stable time base on SMP 736 systems, unlike the TSC, but it is more expensive to access, 737 as it is off-chip. APB timers are always running regardless of CPU 738 C states, they are used as per CPU clockevent device when possible. 739 740# Mark as expert because too many people got it wrong. 741# The code disables itself when not needed. 742config DMI 743 default y 744 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 745 bool "Enable DMI scanning" if EXPERT 746 ---help--- 747 Enabled scanning of DMI to identify machine quirks. Say Y 748 here unless you have verified that your setup is not 749 affected by entries in the DMI blacklist. Required by PNP 750 BIOS code. 751 752config GART_IOMMU 753 bool "Old AMD GART IOMMU support" 754 select SWIOTLB 755 depends on X86_64 && PCI && AMD_NB 756 ---help--- 757 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 758 GART based hardware IOMMUs. 759 760 The GART supports full DMA access for devices with 32-bit access 761 limitations, on systems with more than 3 GB. This is usually needed 762 for USB, sound, many IDE/SATA chipsets and some other devices. 763 764 Newer systems typically have a modern AMD IOMMU, supported via 765 the CONFIG_AMD_IOMMU=y config option. 766 767 In normal configurations this driver is only active when needed: 768 there's more than 3 GB of memory and the system contains a 769 32-bit limited device. 770 771 If unsure, say Y. 772 773config CALGARY_IOMMU 774 bool "IBM Calgary IOMMU support" 775 select SWIOTLB 776 depends on X86_64 && PCI 777 ---help--- 778 Support for hardware IOMMUs in IBM's xSeries x366 and x460 779 systems. Needed to run systems with more than 3GB of memory 780 properly with 32-bit PCI devices that do not support DAC 781 (Double Address Cycle). Calgary also supports bus level 782 isolation, where all DMAs pass through the IOMMU. This 783 prevents them from going anywhere except their intended 784 destination. This catches hard-to-find kernel bugs and 785 mis-behaving drivers and devices that do not use the DMA-API 786 properly to set up their DMA buffers. The IOMMU can be 787 turned off at boot time with the iommu=off parameter. 788 Normally the kernel will make the right choice by itself. 789 If unsure, say Y. 790 791config CALGARY_IOMMU_ENABLED_BY_DEFAULT 792 def_bool y 793 prompt "Should Calgary be enabled by default?" 794 depends on CALGARY_IOMMU 795 ---help--- 796 Should Calgary be enabled by default? if you choose 'y', Calgary 797 will be used (if it exists). If you choose 'n', Calgary will not be 798 used even if it exists. If you choose 'n' and would like to use 799 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 800 If unsure, say Y. 801 802# need this always selected by IOMMU for the VIA workaround 803config SWIOTLB 804 def_bool y if X86_64 805 ---help--- 806 Support for software bounce buffers used on x86-64 systems 807 which don't have a hardware IOMMU. Using this PCI devices 808 which can only access 32-bits of memory can be used on systems 809 with more than 3 GB of memory. 810 If unsure, say Y. 811 812config IOMMU_HELPER 813 def_bool y 814 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 815 816config MAXSMP 817 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 818 depends on X86_64 && SMP && DEBUG_KERNEL 819 select CPUMASK_OFFSTACK 820 ---help--- 821 Enable maximum number of CPUS and NUMA Nodes for this architecture. 822 If unsure, say N. 823 824config NR_CPUS 825 int "Maximum number of CPUs" if SMP && !MAXSMP 826 range 2 8 if SMP && X86_32 && !X86_BIGSMP 827 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 828 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 829 default "1" if !SMP 830 default "8192" if MAXSMP 831 default "32" if SMP && X86_BIGSMP 832 default "8" if SMP 833 ---help--- 834 This allows you to specify the maximum number of CPUs which this 835 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 836 supported value is 4096, otherwise the maximum value is 512. The 837 minimum value which makes sense is 2. 838 839 This is purely to save memory - each supported CPU adds 840 approximately eight kilobytes to the kernel image. 841 842config SCHED_SMT 843 bool "SMT (Hyperthreading) scheduler support" 844 depends on X86_HT 845 ---help--- 846 SMT scheduler support improves the CPU scheduler's decision making 847 when dealing with Intel Pentium 4 chips with HyperThreading at a 848 cost of slightly increased overhead in some places. If unsure say 849 N here. 850 851config SCHED_MC 852 def_bool y 853 prompt "Multi-core scheduler support" 854 depends on X86_HT 855 ---help--- 856 Multi-core scheduler support improves the CPU scheduler's decision 857 making when dealing with multi-core CPU chips at a cost of slightly 858 increased overhead in some places. If unsure say N here. 859 860source "kernel/Kconfig.preempt" 861 862config X86_UP_APIC 863 bool "Local APIC support on uniprocessors" 864 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 865 ---help--- 866 A local APIC (Advanced Programmable Interrupt Controller) is an 867 integrated interrupt controller in the CPU. If you have a single-CPU 868 system which has a processor with a local APIC, you can say Y here to 869 enable and use it. If you say Y here even though your machine doesn't 870 have a local APIC, then the kernel will still run with no slowdown at 871 all. The local APIC supports CPU-generated self-interrupts (timer, 872 performance counters), and the NMI watchdog which detects hard 873 lockups. 874 875config X86_UP_IOAPIC 876 bool "IO-APIC support on uniprocessors" 877 depends on X86_UP_APIC 878 ---help--- 879 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 880 SMP-capable replacement for PC-style interrupt controllers. Most 881 SMP systems and many recent uniprocessor systems have one. 882 883 If you have a single-CPU system with an IO-APIC, you can say Y here 884 to use it. If you say Y here even though your machine doesn't have 885 an IO-APIC, then the kernel will still run with no slowdown at all. 886 887config X86_LOCAL_APIC 888 def_bool y 889 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 890 891config X86_IO_APIC 892 def_bool y 893 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 894 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ 895 select IRQ_DOMAIN 896 897config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 898 bool "Reroute for broken boot IRQs" 899 depends on X86_IO_APIC 900 ---help--- 901 This option enables a workaround that fixes a source of 902 spurious interrupts. This is recommended when threaded 903 interrupt handling is used on systems where the generation of 904 superfluous "boot interrupts" cannot be disabled. 905 906 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 907 entry in the chipset's IO-APIC is masked (as, e.g. the RT 908 kernel does during interrupt handling). On chipsets where this 909 boot IRQ generation cannot be disabled, this workaround keeps 910 the original IRQ line masked so that only the equivalent "boot 911 IRQ" is delivered to the CPUs. The workaround also tells the 912 kernel to set up the IRQ handler on the boot IRQ line. In this 913 way only one interrupt is delivered to the kernel. Otherwise 914 the spurious second interrupt may cause the kernel to bring 915 down (vital) interrupt lines. 916 917 Only affects "broken" chipsets. Interrupt sharing may be 918 increased on these systems. 919 920config X86_MCE 921 bool "Machine Check / overheating reporting" 922 default y 923 ---help--- 924 Machine Check support allows the processor to notify the 925 kernel if it detects a problem (e.g. overheating, data corruption). 926 The action the kernel takes depends on the severity of the problem, 927 ranging from warning messages to halting the machine. 928 929config X86_MCE_INTEL 930 def_bool y 931 prompt "Intel MCE features" 932 depends on X86_MCE && X86_LOCAL_APIC 933 ---help--- 934 Additional support for intel specific MCE features such as 935 the thermal monitor. 936 937config X86_MCE_AMD 938 def_bool y 939 prompt "AMD MCE features" 940 depends on X86_MCE && X86_LOCAL_APIC 941 ---help--- 942 Additional support for AMD specific MCE features such as 943 the DRAM Error Threshold. 944 945config X86_ANCIENT_MCE 946 bool "Support for old Pentium 5 / WinChip machine checks" 947 depends on X86_32 && X86_MCE 948 ---help--- 949 Include support for machine check handling on old Pentium 5 or WinChip 950 systems. These typically need to be enabled explicitly on the command 951 line. 952 953config X86_MCE_THRESHOLD 954 depends on X86_MCE_AMD || X86_MCE_INTEL 955 def_bool y 956 957config X86_MCE_INJECT 958 depends on X86_MCE 959 tristate "Machine check injector support" 960 ---help--- 961 Provide support for injecting machine checks for testing purposes. 962 If you don't know what a machine check is and you don't do kernel 963 QA it is safe to say n. 964 965config X86_THERMAL_VECTOR 966 def_bool y 967 depends on X86_MCE_INTEL 968 969config VM86 970 bool "Enable VM86 support" if EXPERT 971 default y 972 depends on X86_32 973 ---help--- 974 This option is required by programs like DOSEMU to run 975 16-bit real mode legacy code on x86 processors. It also may 976 be needed by software like XFree86 to initialize some video 977 cards via BIOS. Disabling this option saves about 6K. 978 979config X86_16BIT 980 bool "Enable support for 16-bit segments" if EXPERT 981 default y 982 ---help--- 983 This option is required by programs like Wine to run 16-bit 984 protected mode legacy code on x86 processors. Disabling 985 this option saves about 300 bytes on i386, or around 6K text 986 plus 16K runtime memory on x86-64, 987 988config X86_ESPFIX32 989 def_bool y 990 depends on X86_16BIT && X86_32 991 992config X86_ESPFIX64 993 def_bool y 994 depends on X86_16BIT && X86_64 995 996config X86_VSYSCALL_EMULATION 997 bool "Enable vsyscall emulation" if EXPERT 998 default y 999 depends on X86_64 1000 ---help--- 1001 This enables emulation of the legacy vsyscall page. Disabling 1002 it is roughly equivalent to booting with vsyscall=none, except 1003 that it will also disable the helpful warning if a program 1004 tries to use a vsyscall. With this option set to N, offending 1005 programs will just segfault, citing addresses of the form 1006 0xffffffffff600?00. 1007 1008 This option is required by many programs built before 2013, and 1009 care should be used even with newer programs if set to N. 1010 1011 Disabling this option saves about 7K of kernel size and 1012 possibly 4K of additional runtime pagetable memory. 1013 1014config TOSHIBA 1015 tristate "Toshiba Laptop support" 1016 depends on X86_32 1017 ---help--- 1018 This adds a driver to safely access the System Management Mode of 1019 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1020 not work on models with a Phoenix BIOS. The System Management Mode 1021 is used to set the BIOS and power saving options on Toshiba portables. 1022 1023 For information on utilities to make use of this driver see the 1024 Toshiba Linux utilities web site at: 1025 <http://www.buzzard.org.uk/toshiba/>. 1026 1027 Say Y if you intend to run this kernel on a Toshiba portable. 1028 Say N otherwise. 1029 1030config I8K 1031 tristate "Dell laptop support" 1032 select HWMON 1033 ---help--- 1034 This adds a driver to safely access the System Management Mode 1035 of the CPU on the Dell Inspiron 8000. The System Management Mode 1036 is used to read cpu temperature and cooling fan status and to 1037 control the fans on the I8K portables. 1038 1039 This driver has been tested only on the Inspiron 8000 but it may 1040 also work with other Dell laptops. You can force loading on other 1041 models by passing the parameter `force=1' to the module. Use at 1042 your own risk. 1043 1044 For information on utilities to make use of this driver see the 1045 I8K Linux utilities web site at: 1046 <http://people.debian.org/~dz/i8k/> 1047 1048 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1049 Say N otherwise. 1050 1051config X86_REBOOTFIXUPS 1052 bool "Enable X86 board specific fixups for reboot" 1053 depends on X86_32 1054 ---help--- 1055 This enables chipset and/or board specific fixups to be done 1056 in order to get reboot to work correctly. This is only needed on 1057 some combinations of hardware and BIOS. The symptom, for which 1058 this config is intended, is when reboot ends with a stalled/hung 1059 system. 1060 1061 Currently, the only fixup is for the Geode machines using 1062 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1063 1064 Say Y if you want to enable the fixup. Currently, it's safe to 1065 enable this option even if you don't need it. 1066 Say N otherwise. 1067 1068config MICROCODE 1069 tristate "CPU microcode loading support" 1070 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1071 select FW_LOADER 1072 ---help--- 1073 1074 If you say Y here, you will be able to update the microcode on 1075 certain Intel and AMD processors. The Intel support is for the 1076 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1077 Xeon etc. The AMD support is for families 0x10 and later. You will 1078 obviously need the actual microcode binary data itself which is not 1079 shipped with the Linux kernel. 1080 1081 This option selects the general module only, you need to select 1082 at least one vendor specific module as well. 1083 1084 To compile this driver as a module, choose M here: the module 1085 will be called microcode. 1086 1087config MICROCODE_INTEL 1088 bool "Intel microcode loading support" 1089 depends on MICROCODE 1090 default MICROCODE 1091 select FW_LOADER 1092 ---help--- 1093 This options enables microcode patch loading support for Intel 1094 processors. 1095 1096 For the current Intel microcode data package go to 1097 <https://downloadcenter.intel.com> and search for 1098 'Linux Processor Microcode Data File'. 1099 1100config MICROCODE_AMD 1101 bool "AMD microcode loading support" 1102 depends on MICROCODE 1103 select FW_LOADER 1104 ---help--- 1105 If you select this option, microcode patch loading support for AMD 1106 processors will be enabled. 1107 1108config MICROCODE_OLD_INTERFACE 1109 def_bool y 1110 depends on MICROCODE 1111 1112config MICROCODE_INTEL_EARLY 1113 def_bool n 1114 1115config MICROCODE_AMD_EARLY 1116 def_bool n 1117 1118config MICROCODE_EARLY 1119 bool "Early load microcode" 1120 depends on MICROCODE=y && BLK_DEV_INITRD 1121 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1122 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1123 default y 1124 help 1125 This option provides functionality to read additional microcode data 1126 at the beginning of initrd image. The data tells kernel to load 1127 microcode to CPU's as early as possible. No functional change if no 1128 microcode data is glued to the initrd, therefore it's safe to say Y. 1129 1130config X86_MSR 1131 tristate "/dev/cpu/*/msr - Model-specific register support" 1132 ---help--- 1133 This device gives privileged processes access to the x86 1134 Model-Specific Registers (MSRs). It is a character device with 1135 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1136 MSR accesses are directed to a specific CPU on multi-processor 1137 systems. 1138 1139config X86_CPUID 1140 tristate "/dev/cpu/*/cpuid - CPU information support" 1141 ---help--- 1142 This device gives processes access to the x86 CPUID instruction to 1143 be executed on a specific processor. It is a character device 1144 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1145 /dev/cpu/31/cpuid. 1146 1147choice 1148 prompt "High Memory Support" 1149 default HIGHMEM4G 1150 depends on X86_32 1151 1152config NOHIGHMEM 1153 bool "off" 1154 ---help--- 1155 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1156 However, the address space of 32-bit x86 processors is only 4 1157 Gigabytes large. That means that, if you have a large amount of 1158 physical memory, not all of it can be "permanently mapped" by the 1159 kernel. The physical memory that's not permanently mapped is called 1160 "high memory". 1161 1162 If you are compiling a kernel which will never run on a machine with 1163 more than 1 Gigabyte total physical RAM, answer "off" here (default 1164 choice and suitable for most users). This will result in a "3GB/1GB" 1165 split: 3GB are mapped so that each process sees a 3GB virtual memory 1166 space and the remaining part of the 4GB virtual memory space is used 1167 by the kernel to permanently map as much physical memory as 1168 possible. 1169 1170 If the machine has between 1 and 4 Gigabytes physical RAM, then 1171 answer "4GB" here. 1172 1173 If more than 4 Gigabytes is used then answer "64GB" here. This 1174 selection turns Intel PAE (Physical Address Extension) mode on. 1175 PAE implements 3-level paging on IA32 processors. PAE is fully 1176 supported by Linux, PAE mode is implemented on all recent Intel 1177 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1178 then the kernel will not boot on CPUs that don't support PAE! 1179 1180 The actual amount of total physical memory will either be 1181 auto detected or can be forced by using a kernel command line option 1182 such as "mem=256M". (Try "man bootparam" or see the documentation of 1183 your boot loader (lilo or loadlin) about how to pass options to the 1184 kernel at boot time.) 1185 1186 If unsure, say "off". 1187 1188config HIGHMEM4G 1189 bool "4GB" 1190 ---help--- 1191 Select this if you have a 32-bit processor and between 1 and 4 1192 gigabytes of physical RAM. 1193 1194config HIGHMEM64G 1195 bool "64GB" 1196 depends on !M486 1197 select X86_PAE 1198 ---help--- 1199 Select this if you have a 32-bit processor and more than 4 1200 gigabytes of physical RAM. 1201 1202endchoice 1203 1204choice 1205 prompt "Memory split" if EXPERT 1206 default VMSPLIT_3G 1207 depends on X86_32 1208 ---help--- 1209 Select the desired split between kernel and user memory. 1210 1211 If the address range available to the kernel is less than the 1212 physical memory installed, the remaining memory will be available 1213 as "high memory". Accessing high memory is a little more costly 1214 than low memory, as it needs to be mapped into the kernel first. 1215 Note that increasing the kernel address space limits the range 1216 available to user programs, making the address space there 1217 tighter. Selecting anything other than the default 3G/1G split 1218 will also likely make your kernel incompatible with binary-only 1219 kernel modules. 1220 1221 If you are not absolutely sure what you are doing, leave this 1222 option alone! 1223 1224 config VMSPLIT_3G 1225 bool "3G/1G user/kernel split" 1226 config VMSPLIT_3G_OPT 1227 depends on !X86_PAE 1228 bool "3G/1G user/kernel split (for full 1G low memory)" 1229 config VMSPLIT_2G 1230 bool "2G/2G user/kernel split" 1231 config VMSPLIT_2G_OPT 1232 depends on !X86_PAE 1233 bool "2G/2G user/kernel split (for full 2G low memory)" 1234 config VMSPLIT_1G 1235 bool "1G/3G user/kernel split" 1236endchoice 1237 1238config PAGE_OFFSET 1239 hex 1240 default 0xB0000000 if VMSPLIT_3G_OPT 1241 default 0x80000000 if VMSPLIT_2G 1242 default 0x78000000 if VMSPLIT_2G_OPT 1243 default 0x40000000 if VMSPLIT_1G 1244 default 0xC0000000 1245 depends on X86_32 1246 1247config HIGHMEM 1248 def_bool y 1249 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1250 1251config X86_PAE 1252 bool "PAE (Physical Address Extension) Support" 1253 depends on X86_32 && !HIGHMEM4G 1254 ---help--- 1255 PAE is required for NX support, and furthermore enables 1256 larger swapspace support for non-overcommit purposes. It 1257 has the cost of more pagetable lookup overhead, and also 1258 consumes more pagetable space per process. 1259 1260config ARCH_PHYS_ADDR_T_64BIT 1261 def_bool y 1262 depends on X86_64 || X86_PAE 1263 1264config ARCH_DMA_ADDR_T_64BIT 1265 def_bool y 1266 depends on X86_64 || HIGHMEM64G 1267 1268config DIRECT_GBPAGES 1269 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1270 default y 1271 depends on X86_64 1272 ---help--- 1273 Allow the kernel linear mapping to use 1GB pages on CPUs that 1274 support it. This can improve the kernel's performance a tiny bit by 1275 reducing TLB pressure. If in doubt, say "Y". 1276 1277# Common NUMA Features 1278config NUMA 1279 bool "Numa Memory Allocation and Scheduler Support" 1280 depends on SMP 1281 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1282 default y if X86_BIGSMP 1283 ---help--- 1284 Enable NUMA (Non Uniform Memory Access) support. 1285 1286 The kernel will try to allocate memory used by a CPU on the 1287 local memory controller of the CPU and add some more 1288 NUMA awareness to the kernel. 1289 1290 For 64-bit this is recommended if the system is Intel Core i7 1291 (or later), AMD Opteron, or EM64T NUMA. 1292 1293 For 32-bit this is only needed if you boot a 32-bit 1294 kernel on a 64-bit NUMA platform. 1295 1296 Otherwise, you should say N. 1297 1298config AMD_NUMA 1299 def_bool y 1300 prompt "Old style AMD Opteron NUMA detection" 1301 depends on X86_64 && NUMA && PCI 1302 ---help--- 1303 Enable AMD NUMA node topology detection. You should say Y here if 1304 you have a multi processor AMD system. This uses an old method to 1305 read the NUMA configuration directly from the builtin Northbridge 1306 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1307 which also takes priority if both are compiled in. 1308 1309config X86_64_ACPI_NUMA 1310 def_bool y 1311 prompt "ACPI NUMA detection" 1312 depends on X86_64 && NUMA && ACPI && PCI 1313 select ACPI_NUMA 1314 ---help--- 1315 Enable ACPI SRAT based node topology detection. 1316 1317# Some NUMA nodes have memory ranges that span 1318# other nodes. Even though a pfn is valid and 1319# between a node's start and end pfns, it may not 1320# reside on that node. See memmap_init_zone() 1321# for details. 1322config NODES_SPAN_OTHER_NODES 1323 def_bool y 1324 depends on X86_64_ACPI_NUMA 1325 1326config NUMA_EMU 1327 bool "NUMA emulation" 1328 depends on NUMA 1329 ---help--- 1330 Enable NUMA emulation. A flat machine will be split 1331 into virtual nodes when booted with "numa=fake=N", where N is the 1332 number of nodes. This is only useful for debugging. 1333 1334config NODES_SHIFT 1335 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1336 range 1 10 1337 default "10" if MAXSMP 1338 default "6" if X86_64 1339 default "3" 1340 depends on NEED_MULTIPLE_NODES 1341 ---help--- 1342 Specify the maximum number of NUMA Nodes available on the target 1343 system. Increases memory reserved to accommodate various tables. 1344 1345config ARCH_HAVE_MEMORY_PRESENT 1346 def_bool y 1347 depends on X86_32 && DISCONTIGMEM 1348 1349config NEED_NODE_MEMMAP_SIZE 1350 def_bool y 1351 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1352 1353config ARCH_FLATMEM_ENABLE 1354 def_bool y 1355 depends on X86_32 && !NUMA 1356 1357config ARCH_DISCONTIGMEM_ENABLE 1358 def_bool y 1359 depends on NUMA && X86_32 1360 1361config ARCH_DISCONTIGMEM_DEFAULT 1362 def_bool y 1363 depends on NUMA && X86_32 1364 1365config ARCH_SPARSEMEM_ENABLE 1366 def_bool y 1367 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1368 select SPARSEMEM_STATIC if X86_32 1369 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1370 1371config ARCH_SPARSEMEM_DEFAULT 1372 def_bool y 1373 depends on X86_64 1374 1375config ARCH_SELECT_MEMORY_MODEL 1376 def_bool y 1377 depends on ARCH_SPARSEMEM_ENABLE 1378 1379config ARCH_MEMORY_PROBE 1380 bool "Enable sysfs memory/probe interface" 1381 depends on X86_64 && MEMORY_HOTPLUG 1382 help 1383 This option enables a sysfs memory/probe interface for testing. 1384 See Documentation/memory-hotplug.txt for more information. 1385 If you are unsure how to answer this question, answer N. 1386 1387config ARCH_PROC_KCORE_TEXT 1388 def_bool y 1389 depends on X86_64 && PROC_KCORE 1390 1391config ILLEGAL_POINTER_VALUE 1392 hex 1393 default 0 if X86_32 1394 default 0xdead000000000000 if X86_64 1395 1396source "mm/Kconfig" 1397 1398config HIGHPTE 1399 bool "Allocate 3rd-level pagetables from highmem" 1400 depends on HIGHMEM 1401 ---help--- 1402 The VM uses one page table entry for each page of physical memory. 1403 For systems with a lot of RAM, this can be wasteful of precious 1404 low memory. Setting this option will put user-space page table 1405 entries in high memory. 1406 1407config X86_CHECK_BIOS_CORRUPTION 1408 bool "Check for low memory corruption" 1409 ---help--- 1410 Periodically check for memory corruption in low memory, which 1411 is suspected to be caused by BIOS. Even when enabled in the 1412 configuration, it is disabled at runtime. Enable it by 1413 setting "memory_corruption_check=1" on the kernel command 1414 line. By default it scans the low 64k of memory every 60 1415 seconds; see the memory_corruption_check_size and 1416 memory_corruption_check_period parameters in 1417 Documentation/kernel-parameters.txt to adjust this. 1418 1419 When enabled with the default parameters, this option has 1420 almost no overhead, as it reserves a relatively small amount 1421 of memory and scans it infrequently. It both detects corruption 1422 and prevents it from affecting the running system. 1423 1424 It is, however, intended as a diagnostic tool; if repeatable 1425 BIOS-originated corruption always affects the same memory, 1426 you can use memmap= to prevent the kernel from using that 1427 memory. 1428 1429config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1430 bool "Set the default setting of memory_corruption_check" 1431 depends on X86_CHECK_BIOS_CORRUPTION 1432 default y 1433 ---help--- 1434 Set whether the default state of memory_corruption_check is 1435 on or off. 1436 1437config X86_RESERVE_LOW 1438 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1439 default 64 1440 range 4 640 1441 ---help--- 1442 Specify the amount of low memory to reserve for the BIOS. 1443 1444 The first page contains BIOS data structures that the kernel 1445 must not use, so that page must always be reserved. 1446 1447 By default we reserve the first 64K of physical RAM, as a 1448 number of BIOSes are known to corrupt that memory range 1449 during events such as suspend/resume or monitor cable 1450 insertion, so it must not be used by the kernel. 1451 1452 You can set this to 4 if you are absolutely sure that you 1453 trust the BIOS to get all its memory reservations and usages 1454 right. If you know your BIOS have problems beyond the 1455 default 64K area, you can set this to 640 to avoid using the 1456 entire low memory range. 1457 1458 If you have doubts about the BIOS (e.g. suspend/resume does 1459 not work or there's kernel crashes after certain hardware 1460 hotplug events) then you might want to enable 1461 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1462 typical corruption patterns. 1463 1464 Leave this to the default value of 64 if you are unsure. 1465 1466config MATH_EMULATION 1467 bool 1468 prompt "Math emulation" if X86_32 1469 ---help--- 1470 Linux can emulate a math coprocessor (used for floating point 1471 operations) if you don't have one. 486DX and Pentium processors have 1472 a math coprocessor built in, 486SX and 386 do not, unless you added 1473 a 487DX or 387, respectively. (The messages during boot time can 1474 give you some hints here ["man dmesg"].) Everyone needs either a 1475 coprocessor or this emulation. 1476 1477 If you don't have a math coprocessor, you need to say Y here; if you 1478 say Y here even though you have a coprocessor, the coprocessor will 1479 be used nevertheless. (This behavior can be changed with the kernel 1480 command line option "no387", which comes handy if your coprocessor 1481 is broken. Try "man bootparam" or see the documentation of your boot 1482 loader (lilo or loadlin) about how to pass options to the kernel at 1483 boot time.) This means that it is a good idea to say Y here if you 1484 intend to use this kernel on different machines. 1485 1486 More information about the internals of the Linux math coprocessor 1487 emulation can be found in <file:arch/x86/math-emu/README>. 1488 1489 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1490 kernel, it won't hurt. 1491 1492config MTRR 1493 def_bool y 1494 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1495 ---help--- 1496 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1497 the Memory Type Range Registers (MTRRs) may be used to control 1498 processor access to memory ranges. This is most useful if you have 1499 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1500 allows bus write transfers to be combined into a larger transfer 1501 before bursting over the PCI/AGP bus. This can increase performance 1502 of image write operations 2.5 times or more. Saying Y here creates a 1503 /proc/mtrr file which may be used to manipulate your processor's 1504 MTRRs. Typically the X server should use this. 1505 1506 This code has a reasonably generic interface so that similar 1507 control registers on other processors can be easily supported 1508 as well: 1509 1510 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1511 Registers (ARRs) which provide a similar functionality to MTRRs. For 1512 these, the ARRs are used to emulate the MTRRs. 1513 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1514 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1515 write-combining. All of these processors are supported by this code 1516 and it makes sense to say Y here if you have one of them. 1517 1518 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1519 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1520 can lead to all sorts of problems, so it's good to say Y here. 1521 1522 You can safely say Y even if your machine doesn't have MTRRs, you'll 1523 just add about 9 KB to your kernel. 1524 1525 See <file:Documentation/x86/mtrr.txt> for more information. 1526 1527config MTRR_SANITIZER 1528 def_bool y 1529 prompt "MTRR cleanup support" 1530 depends on MTRR 1531 ---help--- 1532 Convert MTRR layout from continuous to discrete, so X drivers can 1533 add writeback entries. 1534 1535 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1536 The largest mtrr entry size for a continuous block can be set with 1537 mtrr_chunk_size. 1538 1539 If unsure, say Y. 1540 1541config MTRR_SANITIZER_ENABLE_DEFAULT 1542 int "MTRR cleanup enable value (0-1)" 1543 range 0 1 1544 default "0" 1545 depends on MTRR_SANITIZER 1546 ---help--- 1547 Enable mtrr cleanup default value 1548 1549config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1550 int "MTRR cleanup spare reg num (0-7)" 1551 range 0 7 1552 default "1" 1553 depends on MTRR_SANITIZER 1554 ---help--- 1555 mtrr cleanup spare entries default, it can be changed via 1556 mtrr_spare_reg_nr=N on the kernel command line. 1557 1558config X86_PAT 1559 def_bool y 1560 prompt "x86 PAT support" if EXPERT 1561 depends on MTRR 1562 ---help--- 1563 Use PAT attributes to setup page level cache control. 1564 1565 PATs are the modern equivalents of MTRRs and are much more 1566 flexible than MTRRs. 1567 1568 Say N here if you see bootup problems (boot crash, boot hang, 1569 spontaneous reboots) or a non-working video driver. 1570 1571 If unsure, say Y. 1572 1573config ARCH_USES_PG_UNCACHED 1574 def_bool y 1575 depends on X86_PAT 1576 1577config ARCH_RANDOM 1578 def_bool y 1579 prompt "x86 architectural random number generator" if EXPERT 1580 ---help--- 1581 Enable the x86 architectural RDRAND instruction 1582 (Intel Bull Mountain technology) to generate random numbers. 1583 If supported, this is a high bandwidth, cryptographically 1584 secure hardware random number generator. 1585 1586config X86_SMAP 1587 def_bool y 1588 prompt "Supervisor Mode Access Prevention" if EXPERT 1589 ---help--- 1590 Supervisor Mode Access Prevention (SMAP) is a security 1591 feature in newer Intel processors. There is a small 1592 performance cost if this enabled and turned on; there is 1593 also a small increase in the kernel size if this is enabled. 1594 1595 If unsure, say Y. 1596 1597config EFI 1598 bool "EFI runtime service support" 1599 depends on ACPI 1600 select UCS2_STRING 1601 select EFI_RUNTIME_WRAPPERS 1602 ---help--- 1603 This enables the kernel to use EFI runtime services that are 1604 available (such as the EFI variable services). 1605 1606 This option is only useful on systems that have EFI firmware. 1607 In addition, you should use the latest ELILO loader available 1608 at <http://elilo.sourceforge.net> in order to take advantage 1609 of EFI runtime services. However, even with this option, the 1610 resultant kernel should continue to boot on existing non-EFI 1611 platforms. 1612 1613config EFI_STUB 1614 bool "EFI stub support" 1615 depends on EFI && !X86_USE_3DNOW 1616 select RELOCATABLE 1617 ---help--- 1618 This kernel feature allows a bzImage to be loaded directly 1619 by EFI firmware without the use of a bootloader. 1620 1621 See Documentation/efi-stub.txt for more information. 1622 1623config EFI_MIXED 1624 bool "EFI mixed-mode support" 1625 depends on EFI_STUB && X86_64 1626 ---help--- 1627 Enabling this feature allows a 64-bit kernel to be booted 1628 on a 32-bit firmware, provided that your CPU supports 64-bit 1629 mode. 1630 1631 Note that it is not possible to boot a mixed-mode enabled 1632 kernel via the EFI boot stub - a bootloader that supports 1633 the EFI handover protocol must be used. 1634 1635 If unsure, say N. 1636 1637config SECCOMP 1638 def_bool y 1639 prompt "Enable seccomp to safely compute untrusted bytecode" 1640 ---help--- 1641 This kernel feature is useful for number crunching applications 1642 that may need to compute untrusted bytecode during their 1643 execution. By using pipes or other transports made available to 1644 the process as file descriptors supporting the read/write 1645 syscalls, it's possible to isolate those applications in 1646 their own address space using seccomp. Once seccomp is 1647 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1648 and the task is only allowed to execute a few safe syscalls 1649 defined by each seccomp mode. 1650 1651 If unsure, say Y. Only embedded should say N here. 1652 1653source kernel/Kconfig.hz 1654 1655config KEXEC 1656 bool "kexec system call" 1657 ---help--- 1658 kexec is a system call that implements the ability to shutdown your 1659 current kernel, and to start another kernel. It is like a reboot 1660 but it is independent of the system firmware. And like a reboot 1661 you can start any kernel with it, not just Linux. 1662 1663 The name comes from the similarity to the exec system call. 1664 1665 It is an ongoing process to be certain the hardware in a machine 1666 is properly shutdown, so do not be surprised if this code does not 1667 initially work for you. As of this writing the exact hardware 1668 interface is strongly in flux, so no good recommendation can be 1669 made. 1670 1671config KEXEC_FILE 1672 bool "kexec file based system call" 1673 select BUILD_BIN2C 1674 depends on KEXEC 1675 depends on X86_64 1676 depends on CRYPTO=y 1677 depends on CRYPTO_SHA256=y 1678 ---help--- 1679 This is new version of kexec system call. This system call is 1680 file based and takes file descriptors as system call argument 1681 for kernel and initramfs as opposed to list of segments as 1682 accepted by previous system call. 1683 1684config KEXEC_VERIFY_SIG 1685 bool "Verify kernel signature during kexec_file_load() syscall" 1686 depends on KEXEC_FILE 1687 ---help--- 1688 This option makes kernel signature verification mandatory for 1689 kexec_file_load() syscall. If kernel is signature can not be 1690 verified, kexec_file_load() will fail. 1691 1692 This option enforces signature verification at generic level. 1693 One needs to enable signature verification for type of kernel 1694 image being loaded to make sure it works. For example, enable 1695 bzImage signature verification option to be able to load and 1696 verify signatures of bzImage. Otherwise kernel loading will fail. 1697 1698config KEXEC_BZIMAGE_VERIFY_SIG 1699 bool "Enable bzImage signature verification support" 1700 depends on KEXEC_VERIFY_SIG 1701 depends on SIGNED_PE_FILE_VERIFICATION 1702 select SYSTEM_TRUSTED_KEYRING 1703 ---help--- 1704 Enable bzImage signature verification support. 1705 1706config CRASH_DUMP 1707 bool "kernel crash dumps" 1708 depends on X86_64 || (X86_32 && HIGHMEM) 1709 ---help--- 1710 Generate crash dump after being started by kexec. 1711 This should be normally only set in special crash dump kernels 1712 which are loaded in the main kernel with kexec-tools into 1713 a specially reserved region and then later executed after 1714 a crash by kdump/kexec. The crash dump kernel must be compiled 1715 to a memory address not used by the main kernel or BIOS using 1716 PHYSICAL_START, or it must be built as a relocatable image 1717 (CONFIG_RELOCATABLE=y). 1718 For more details see Documentation/kdump/kdump.txt 1719 1720config KEXEC_JUMP 1721 bool "kexec jump" 1722 depends on KEXEC && HIBERNATION 1723 ---help--- 1724 Jump between original kernel and kexeced kernel and invoke 1725 code in physical address mode via KEXEC 1726 1727config PHYSICAL_START 1728 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1729 default "0x1000000" 1730 ---help--- 1731 This gives the physical address where the kernel is loaded. 1732 1733 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1734 bzImage will decompress itself to above physical address and 1735 run from there. Otherwise, bzImage will run from the address where 1736 it has been loaded by the boot loader and will ignore above physical 1737 address. 1738 1739 In normal kdump cases one does not have to set/change this option 1740 as now bzImage can be compiled as a completely relocatable image 1741 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1742 address. This option is mainly useful for the folks who don't want 1743 to use a bzImage for capturing the crash dump and want to use a 1744 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1745 to be specifically compiled to run from a specific memory area 1746 (normally a reserved region) and this option comes handy. 1747 1748 So if you are using bzImage for capturing the crash dump, 1749 leave the value here unchanged to 0x1000000 and set 1750 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1751 for capturing the crash dump change this value to start of 1752 the reserved region. In other words, it can be set based on 1753 the "X" value as specified in the "crashkernel=YM@XM" 1754 command line boot parameter passed to the panic-ed 1755 kernel. Please take a look at Documentation/kdump/kdump.txt 1756 for more details about crash dumps. 1757 1758 Usage of bzImage for capturing the crash dump is recommended as 1759 one does not have to build two kernels. Same kernel can be used 1760 as production kernel and capture kernel. Above option should have 1761 gone away after relocatable bzImage support is introduced. But it 1762 is present because there are users out there who continue to use 1763 vmlinux for dump capture. This option should go away down the 1764 line. 1765 1766 Don't change this unless you know what you are doing. 1767 1768config RELOCATABLE 1769 bool "Build a relocatable kernel" 1770 default y 1771 ---help--- 1772 This builds a kernel image that retains relocation information 1773 so it can be loaded someplace besides the default 1MB. 1774 The relocations tend to make the kernel binary about 10% larger, 1775 but are discarded at runtime. 1776 1777 One use is for the kexec on panic case where the recovery kernel 1778 must live at a different physical address than the primary 1779 kernel. 1780 1781 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1782 it has been loaded at and the compile time physical address 1783 (CONFIG_PHYSICAL_START) is used as the minimum location. 1784 1785config RANDOMIZE_BASE 1786 bool "Randomize the address of the kernel image" 1787 depends on RELOCATABLE 1788 default n 1789 ---help--- 1790 Randomizes the physical and virtual address at which the 1791 kernel image is decompressed, as a security feature that 1792 deters exploit attempts relying on knowledge of the location 1793 of kernel internals. 1794 1795 Entropy is generated using the RDRAND instruction if it is 1796 supported. If RDTSC is supported, it is used as well. If 1797 neither RDRAND nor RDTSC are supported, then randomness is 1798 read from the i8254 timer. 1799 1800 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1801 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1802 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1803 minimum of 2MiB, only 10 bits of entropy is theoretically 1804 possible. At best, due to page table layouts, 64-bit can use 1805 9 bits of entropy and 32-bit uses 8 bits. 1806 1807 If unsure, say N. 1808 1809config RANDOMIZE_BASE_MAX_OFFSET 1810 hex "Maximum kASLR offset allowed" if EXPERT 1811 depends on RANDOMIZE_BASE 1812 range 0x0 0x20000000 if X86_32 1813 default "0x20000000" if X86_32 1814 range 0x0 0x40000000 if X86_64 1815 default "0x40000000" if X86_64 1816 ---help--- 1817 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1818 memory is used to determine the maximal offset in bytes that will 1819 be applied to the kernel when kernel Address Space Layout 1820 Randomization (kASLR) is active. This must be a multiple of 1821 PHYSICAL_ALIGN. 1822 1823 On 32-bit this is limited to 512MiB by page table layouts. The 1824 default is 512MiB. 1825 1826 On 64-bit this is limited by how the kernel fixmap page table is 1827 positioned, so this cannot be larger than 1GiB currently. Without 1828 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1829 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1830 modules area will shrink to compensate, up to the current maximum 1831 1GiB to 1GiB split. The default is 1GiB. 1832 1833 If unsure, leave at the default value. 1834 1835# Relocation on x86 needs some additional build support 1836config X86_NEED_RELOCS 1837 def_bool y 1838 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1839 1840config PHYSICAL_ALIGN 1841 hex "Alignment value to which kernel should be aligned" 1842 default "0x200000" 1843 range 0x2000 0x1000000 if X86_32 1844 range 0x200000 0x1000000 if X86_64 1845 ---help--- 1846 This value puts the alignment restrictions on physical address 1847 where kernel is loaded and run from. Kernel is compiled for an 1848 address which meets above alignment restriction. 1849 1850 If bootloader loads the kernel at a non-aligned address and 1851 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1852 address aligned to above value and run from there. 1853 1854 If bootloader loads the kernel at a non-aligned address and 1855 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1856 load address and decompress itself to the address it has been 1857 compiled for and run from there. The address for which kernel is 1858 compiled already meets above alignment restrictions. Hence the 1859 end result is that kernel runs from a physical address meeting 1860 above alignment restrictions. 1861 1862 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1863 this value must be a multiple of 0x200000. 1864 1865 Don't change this unless you know what you are doing. 1866 1867config HOTPLUG_CPU 1868 bool "Support for hot-pluggable CPUs" 1869 depends on SMP 1870 ---help--- 1871 Say Y here to allow turning CPUs off and on. CPUs can be 1872 controlled through /sys/devices/system/cpu. 1873 ( Note: power management support will enable this option 1874 automatically on SMP systems. ) 1875 Say N if you want to disable CPU hotplug. 1876 1877config BOOTPARAM_HOTPLUG_CPU0 1878 bool "Set default setting of cpu0_hotpluggable" 1879 default n 1880 depends on HOTPLUG_CPU 1881 ---help--- 1882 Set whether default state of cpu0_hotpluggable is on or off. 1883 1884 Say Y here to enable CPU0 hotplug by default. If this switch 1885 is turned on, there is no need to give cpu0_hotplug kernel 1886 parameter and the CPU0 hotplug feature is enabled by default. 1887 1888 Please note: there are two known CPU0 dependencies if you want 1889 to enable the CPU0 hotplug feature either by this switch or by 1890 cpu0_hotplug kernel parameter. 1891 1892 First, resume from hibernate or suspend always starts from CPU0. 1893 So hibernate and suspend are prevented if CPU0 is offline. 1894 1895 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1896 offline if any interrupt can not migrate out of CPU0. There may 1897 be other CPU0 dependencies. 1898 1899 Please make sure the dependencies are under your control before 1900 you enable this feature. 1901 1902 Say N if you don't want to enable CPU0 hotplug feature by default. 1903 You still can enable the CPU0 hotplug feature at boot by kernel 1904 parameter cpu0_hotplug. 1905 1906config DEBUG_HOTPLUG_CPU0 1907 def_bool n 1908 prompt "Debug CPU0 hotplug" 1909 depends on HOTPLUG_CPU 1910 ---help--- 1911 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1912 soon as possible and boots up userspace with CPU0 offlined. User 1913 can online CPU0 back after boot time. 1914 1915 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1916 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1917 compilation or giving cpu0_hotplug kernel parameter at boot. 1918 1919 If unsure, say N. 1920 1921config COMPAT_VDSO 1922 def_bool n 1923 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 1924 depends on X86_32 || IA32_EMULATION 1925 ---help--- 1926 Certain buggy versions of glibc will crash if they are 1927 presented with a 32-bit vDSO that is not mapped at the address 1928 indicated in its segment table. 1929 1930 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 1931 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 1932 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 1933 the only released version with the bug, but OpenSUSE 9 1934 contains a buggy "glibc 2.3.2". 1935 1936 The symptom of the bug is that everything crashes on startup, saying: 1937 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 1938 1939 Saying Y here changes the default value of the vdso32 boot 1940 option from 1 to 0, which turns off the 32-bit vDSO entirely. 1941 This works around the glibc bug but hurts performance. 1942 1943 If unsure, say N: if you are compiling your own kernel, you 1944 are unlikely to be using a buggy version of glibc. 1945 1946config CMDLINE_BOOL 1947 bool "Built-in kernel command line" 1948 ---help--- 1949 Allow for specifying boot arguments to the kernel at 1950 build time. On some systems (e.g. embedded ones), it is 1951 necessary or convenient to provide some or all of the 1952 kernel boot arguments with the kernel itself (that is, 1953 to not rely on the boot loader to provide them.) 1954 1955 To compile command line arguments into the kernel, 1956 set this option to 'Y', then fill in the 1957 the boot arguments in CONFIG_CMDLINE. 1958 1959 Systems with fully functional boot loaders (i.e. non-embedded) 1960 should leave this option set to 'N'. 1961 1962config CMDLINE 1963 string "Built-in kernel command string" 1964 depends on CMDLINE_BOOL 1965 default "" 1966 ---help--- 1967 Enter arguments here that should be compiled into the kernel 1968 image and used at boot time. If the boot loader provides a 1969 command line at boot time, it is appended to this string to 1970 form the full kernel command line, when the system boots. 1971 1972 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1973 change this behavior. 1974 1975 In most cases, the command line (whether built-in or provided 1976 by the boot loader) should specify the device for the root 1977 file system. 1978 1979config CMDLINE_OVERRIDE 1980 bool "Built-in command line overrides boot loader arguments" 1981 depends on CMDLINE_BOOL 1982 ---help--- 1983 Set this option to 'Y' to have the kernel ignore the boot loader 1984 command line, and use ONLY the built-in command line. 1985 1986 This is used to work around broken boot loaders. This should 1987 be set to 'N' under normal conditions. 1988 1989endmenu 1990 1991config ARCH_ENABLE_MEMORY_HOTPLUG 1992 def_bool y 1993 depends on X86_64 || (X86_32 && HIGHMEM) 1994 1995config ARCH_ENABLE_MEMORY_HOTREMOVE 1996 def_bool y 1997 depends on MEMORY_HOTPLUG 1998 1999config USE_PERCPU_NUMA_NODE_ID 2000 def_bool y 2001 depends on NUMA 2002 2003config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2004 def_bool y 2005 depends on X86_64 || X86_PAE 2006 2007config ARCH_ENABLE_HUGEPAGE_MIGRATION 2008 def_bool y 2009 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2010 2011menu "Power management and ACPI options" 2012 2013config ARCH_HIBERNATION_HEADER 2014 def_bool y 2015 depends on X86_64 && HIBERNATION 2016 2017source "kernel/power/Kconfig" 2018 2019source "drivers/acpi/Kconfig" 2020 2021source "drivers/sfi/Kconfig" 2022 2023config X86_APM_BOOT 2024 def_bool y 2025 depends on APM 2026 2027menuconfig APM 2028 tristate "APM (Advanced Power Management) BIOS support" 2029 depends on X86_32 && PM_SLEEP 2030 ---help--- 2031 APM is a BIOS specification for saving power using several different 2032 techniques. This is mostly useful for battery powered laptops with 2033 APM compliant BIOSes. If you say Y here, the system time will be 2034 reset after a RESUME operation, the /proc/apm device will provide 2035 battery status information, and user-space programs will receive 2036 notification of APM "events" (e.g. battery status change). 2037 2038 If you select "Y" here, you can disable actual use of the APM 2039 BIOS by passing the "apm=off" option to the kernel at boot time. 2040 2041 Note that the APM support is almost completely disabled for 2042 machines with more than one CPU. 2043 2044 In order to use APM, you will need supporting software. For location 2045 and more information, read <file:Documentation/power/apm-acpi.txt> 2046 and the Battery Powered Linux mini-HOWTO, available from 2047 <http://www.tldp.org/docs.html#howto>. 2048 2049 This driver does not spin down disk drives (see the hdparm(8) 2050 manpage ("man 8 hdparm") for that), and it doesn't turn off 2051 VESA-compliant "green" monitors. 2052 2053 This driver does not support the TI 4000M TravelMate and the ACER 2054 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2055 desktop machines also don't have compliant BIOSes, and this driver 2056 may cause those machines to panic during the boot phase. 2057 2058 Generally, if you don't have a battery in your machine, there isn't 2059 much point in using this driver and you should say N. If you get 2060 random kernel OOPSes or reboots that don't seem to be related to 2061 anything, try disabling/enabling this option (or disabling/enabling 2062 APM in your BIOS). 2063 2064 Some other things you should try when experiencing seemingly random, 2065 "weird" problems: 2066 2067 1) make sure that you have enough swap space and that it is 2068 enabled. 2069 2) pass the "no-hlt" option to the kernel 2070 3) switch on floating point emulation in the kernel and pass 2071 the "no387" option to the kernel 2072 4) pass the "floppy=nodma" option to the kernel 2073 5) pass the "mem=4M" option to the kernel (thereby disabling 2074 all but the first 4 MB of RAM) 2075 6) make sure that the CPU is not over clocked. 2076 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2077 8) disable the cache from your BIOS settings 2078 9) install a fan for the video card or exchange video RAM 2079 10) install a better fan for the CPU 2080 11) exchange RAM chips 2081 12) exchange the motherboard. 2082 2083 To compile this driver as a module, choose M here: the 2084 module will be called apm. 2085 2086if APM 2087 2088config APM_IGNORE_USER_SUSPEND 2089 bool "Ignore USER SUSPEND" 2090 ---help--- 2091 This option will ignore USER SUSPEND requests. On machines with a 2092 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2093 series notebooks, it is necessary to say Y because of a BIOS bug. 2094 2095config APM_DO_ENABLE 2096 bool "Enable PM at boot time" 2097 ---help--- 2098 Enable APM features at boot time. From page 36 of the APM BIOS 2099 specification: "When disabled, the APM BIOS does not automatically 2100 power manage devices, enter the Standby State, enter the Suspend 2101 State, or take power saving steps in response to CPU Idle calls." 2102 This driver will make CPU Idle calls when Linux is idle (unless this 2103 feature is turned off -- see "Do CPU IDLE calls", below). This 2104 should always save battery power, but more complicated APM features 2105 will be dependent on your BIOS implementation. You may need to turn 2106 this option off if your computer hangs at boot time when using APM 2107 support, or if it beeps continuously instead of suspending. Turn 2108 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2109 T400CDT. This is off by default since most machines do fine without 2110 this feature. 2111 2112config APM_CPU_IDLE 2113 depends on CPU_IDLE 2114 bool "Make CPU Idle calls when idle" 2115 ---help--- 2116 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2117 On some machines, this can activate improved power savings, such as 2118 a slowed CPU clock rate, when the machine is idle. These idle calls 2119 are made after the idle loop has run for some length of time (e.g., 2120 333 mS). On some machines, this will cause a hang at boot time or 2121 whenever the CPU becomes idle. (On machines with more than one CPU, 2122 this option does nothing.) 2123 2124config APM_DISPLAY_BLANK 2125 bool "Enable console blanking using APM" 2126 ---help--- 2127 Enable console blanking using the APM. Some laptops can use this to 2128 turn off the LCD backlight when the screen blanker of the Linux 2129 virtual console blanks the screen. Note that this is only used by 2130 the virtual console screen blanker, and won't turn off the backlight 2131 when using the X Window system. This also doesn't have anything to 2132 do with your VESA-compliant power-saving monitor. Further, this 2133 option doesn't work for all laptops -- it might not turn off your 2134 backlight at all, or it might print a lot of errors to the console, 2135 especially if you are using gpm. 2136 2137config APM_ALLOW_INTS 2138 bool "Allow interrupts during APM BIOS calls" 2139 ---help--- 2140 Normally we disable external interrupts while we are making calls to 2141 the APM BIOS as a measure to lessen the effects of a badly behaving 2142 BIOS implementation. The BIOS should reenable interrupts if it 2143 needs to. Unfortunately, some BIOSes do not -- especially those in 2144 many of the newer IBM Thinkpads. If you experience hangs when you 2145 suspend, try setting this to Y. Otherwise, say N. 2146 2147endif # APM 2148 2149source "drivers/cpufreq/Kconfig" 2150 2151source "drivers/cpuidle/Kconfig" 2152 2153source "drivers/idle/Kconfig" 2154 2155endmenu 2156 2157 2158menu "Bus options (PCI etc.)" 2159 2160config PCI 2161 bool "PCI support" 2162 default y 2163 ---help--- 2164 Find out whether you have a PCI motherboard. PCI is the name of a 2165 bus system, i.e. the way the CPU talks to the other stuff inside 2166 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2167 VESA. If you have PCI, say Y, otherwise N. 2168 2169choice 2170 prompt "PCI access mode" 2171 depends on X86_32 && PCI 2172 default PCI_GOANY 2173 ---help--- 2174 On PCI systems, the BIOS can be used to detect the PCI devices and 2175 determine their configuration. However, some old PCI motherboards 2176 have BIOS bugs and may crash if this is done. Also, some embedded 2177 PCI-based systems don't have any BIOS at all. Linux can also try to 2178 detect the PCI hardware directly without using the BIOS. 2179 2180 With this option, you can specify how Linux should detect the 2181 PCI devices. If you choose "BIOS", the BIOS will be used, 2182 if you choose "Direct", the BIOS won't be used, and if you 2183 choose "MMConfig", then PCI Express MMCONFIG will be used. 2184 If you choose "Any", the kernel will try MMCONFIG, then the 2185 direct access method and falls back to the BIOS if that doesn't 2186 work. If unsure, go with the default, which is "Any". 2187 2188config PCI_GOBIOS 2189 bool "BIOS" 2190 2191config PCI_GOMMCONFIG 2192 bool "MMConfig" 2193 2194config PCI_GODIRECT 2195 bool "Direct" 2196 2197config PCI_GOOLPC 2198 bool "OLPC XO-1" 2199 depends on OLPC 2200 2201config PCI_GOANY 2202 bool "Any" 2203 2204endchoice 2205 2206config PCI_BIOS 2207 def_bool y 2208 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2209 2210# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2211config PCI_DIRECT 2212 def_bool y 2213 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2214 2215config PCI_MMCONFIG 2216 def_bool y 2217 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2218 2219config PCI_OLPC 2220 def_bool y 2221 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2222 2223config PCI_XEN 2224 def_bool y 2225 depends on PCI && XEN 2226 select SWIOTLB_XEN 2227 2228config PCI_DOMAINS 2229 def_bool y 2230 depends on PCI 2231 2232config PCI_MMCONFIG 2233 bool "Support mmconfig PCI config space access" 2234 depends on X86_64 && PCI && ACPI 2235 2236config PCI_CNB20LE_QUIRK 2237 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2238 depends on PCI 2239 help 2240 Read the PCI windows out of the CNB20LE host bridge. This allows 2241 PCI hotplug to work on systems with the CNB20LE chipset which do 2242 not have ACPI. 2243 2244 There's no public spec for this chipset, and this functionality 2245 is known to be incomplete. 2246 2247 You should say N unless you know you need this. 2248 2249source "drivers/pci/pcie/Kconfig" 2250 2251source "drivers/pci/Kconfig" 2252 2253# x86_64 have no ISA slots, but can have ISA-style DMA. 2254config ISA_DMA_API 2255 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2256 default y 2257 help 2258 Enables ISA-style DMA support for devices requiring such controllers. 2259 If unsure, say Y. 2260 2261if X86_32 2262 2263config ISA 2264 bool "ISA support" 2265 ---help--- 2266 Find out whether you have ISA slots on your motherboard. ISA is the 2267 name of a bus system, i.e. the way the CPU talks to the other stuff 2268 inside your box. Other bus systems are PCI, EISA, MicroChannel 2269 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2270 newer boards don't support it. If you have ISA, say Y, otherwise N. 2271 2272config EISA 2273 bool "EISA support" 2274 depends on ISA 2275 ---help--- 2276 The Extended Industry Standard Architecture (EISA) bus was 2277 developed as an open alternative to the IBM MicroChannel bus. 2278 2279 The EISA bus provided some of the features of the IBM MicroChannel 2280 bus while maintaining backward compatibility with cards made for 2281 the older ISA bus. The EISA bus saw limited use between 1988 and 2282 1995 when it was made obsolete by the PCI bus. 2283 2284 Say Y here if you are building a kernel for an EISA-based machine. 2285 2286 Otherwise, say N. 2287 2288source "drivers/eisa/Kconfig" 2289 2290config SCx200 2291 tristate "NatSemi SCx200 support" 2292 ---help--- 2293 This provides basic support for National Semiconductor's 2294 (now AMD's) Geode processors. The driver probes for the 2295 PCI-IDs of several on-chip devices, so its a good dependency 2296 for other scx200_* drivers. 2297 2298 If compiled as a module, the driver is named scx200. 2299 2300config SCx200HR_TIMER 2301 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2302 depends on SCx200 2303 default y 2304 ---help--- 2305 This driver provides a clocksource built upon the on-chip 2306 27MHz high-resolution timer. Its also a workaround for 2307 NSC Geode SC-1100's buggy TSC, which loses time when the 2308 processor goes idle (as is done by the scheduler). The 2309 other workaround is idle=poll boot option. 2310 2311config OLPC 2312 bool "One Laptop Per Child support" 2313 depends on !X86_PAE 2314 select GPIOLIB 2315 select OF 2316 select OF_PROMTREE 2317 select IRQ_DOMAIN 2318 ---help--- 2319 Add support for detecting the unique features of the OLPC 2320 XO hardware. 2321 2322config OLPC_XO1_PM 2323 bool "OLPC XO-1 Power Management" 2324 depends on OLPC && MFD_CS5535 && PM_SLEEP 2325 select MFD_CORE 2326 ---help--- 2327 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2328 2329config OLPC_XO1_RTC 2330 bool "OLPC XO-1 Real Time Clock" 2331 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2332 ---help--- 2333 Add support for the XO-1 real time clock, which can be used as a 2334 programmable wakeup source. 2335 2336config OLPC_XO1_SCI 2337 bool "OLPC XO-1 SCI extras" 2338 depends on OLPC && OLPC_XO1_PM 2339 depends on INPUT=y 2340 select POWER_SUPPLY 2341 select GPIO_CS5535 2342 select MFD_CORE 2343 ---help--- 2344 Add support for SCI-based features of the OLPC XO-1 laptop: 2345 - EC-driven system wakeups 2346 - Power button 2347 - Ebook switch 2348 - Lid switch 2349 - AC adapter status updates 2350 - Battery status updates 2351 2352config OLPC_XO15_SCI 2353 bool "OLPC XO-1.5 SCI extras" 2354 depends on OLPC && ACPI 2355 select POWER_SUPPLY 2356 ---help--- 2357 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2358 - EC-driven system wakeups 2359 - AC adapter status updates 2360 - Battery status updates 2361 2362config ALIX 2363 bool "PCEngines ALIX System Support (LED setup)" 2364 select GPIOLIB 2365 ---help--- 2366 This option enables system support for the PCEngines ALIX. 2367 At present this just sets up LEDs for GPIO control on 2368 ALIX2/3/6 boards. However, other system specific setup should 2369 get added here. 2370 2371 Note: You must still enable the drivers for GPIO and LED support 2372 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2373 2374 Note: You have to set alix.force=1 for boards with Award BIOS. 2375 2376config NET5501 2377 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2378 select GPIOLIB 2379 ---help--- 2380 This option enables system support for the Soekris Engineering net5501. 2381 2382config GEOS 2383 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2384 select GPIOLIB 2385 depends on DMI 2386 ---help--- 2387 This option enables system support for the Traverse Technologies GEOS. 2388 2389config TS5500 2390 bool "Technologic Systems TS-5500 platform support" 2391 depends on MELAN 2392 select CHECK_SIGNATURE 2393 select NEW_LEDS 2394 select LEDS_CLASS 2395 ---help--- 2396 This option enables system support for the Technologic Systems TS-5500. 2397 2398endif # X86_32 2399 2400config AMD_NB 2401 def_bool y 2402 depends on CPU_SUP_AMD && PCI 2403 2404source "drivers/pcmcia/Kconfig" 2405 2406source "drivers/pci/hotplug/Kconfig" 2407 2408config RAPIDIO 2409 tristate "RapidIO support" 2410 depends on PCI 2411 default n 2412 help 2413 If enabled this option will include drivers and the core 2414 infrastructure code to support RapidIO interconnect devices. 2415 2416source "drivers/rapidio/Kconfig" 2417 2418config X86_SYSFB 2419 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2420 help 2421 Firmwares often provide initial graphics framebuffers so the BIOS, 2422 bootloader or kernel can show basic video-output during boot for 2423 user-guidance and debugging. Historically, x86 used the VESA BIOS 2424 Extensions and EFI-framebuffers for this, which are mostly limited 2425 to x86. 2426 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2427 framebuffers so the new generic system-framebuffer drivers can be 2428 used on x86. If the framebuffer is not compatible with the generic 2429 modes, it is adverticed as fallback platform framebuffer so legacy 2430 drivers like efifb, vesafb and uvesafb can pick it up. 2431 If this option is not selected, all system framebuffers are always 2432 marked as fallback platform framebuffers as usual. 2433 2434 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2435 not be able to pick up generic system framebuffers if this option 2436 is selected. You are highly encouraged to enable simplefb as 2437 replacement if you select this option. simplefb can correctly deal 2438 with generic system framebuffers. But you should still keep vesafb 2439 and others enabled as fallback if a system framebuffer is 2440 incompatible with simplefb. 2441 2442 If unsure, say Y. 2443 2444endmenu 2445 2446 2447menu "Executable file formats / Emulations" 2448 2449source "fs/Kconfig.binfmt" 2450 2451config IA32_EMULATION 2452 bool "IA32 Emulation" 2453 depends on X86_64 2454 select BINFMT_ELF 2455 select COMPAT_BINFMT_ELF 2456 select HAVE_UID16 2457 ---help--- 2458 Include code to run legacy 32-bit programs under a 2459 64-bit kernel. You should likely turn this on, unless you're 2460 100% sure that you don't have any 32-bit programs left. 2461 2462config IA32_AOUT 2463 tristate "IA32 a.out support" 2464 depends on IA32_EMULATION 2465 ---help--- 2466 Support old a.out binaries in the 32bit emulation. 2467 2468config X86_X32 2469 bool "x32 ABI for 64-bit mode" 2470 depends on X86_64 && IA32_EMULATION 2471 ---help--- 2472 Include code to run binaries for the x32 native 32-bit ABI 2473 for 64-bit processors. An x32 process gets access to the 2474 full 64-bit register file and wide data path while leaving 2475 pointers at 32 bits for smaller memory footprint. 2476 2477 You will need a recent binutils (2.22 or later) with 2478 elf32_x86_64 support enabled to compile a kernel with this 2479 option set. 2480 2481config COMPAT 2482 def_bool y 2483 depends on IA32_EMULATION || X86_X32 2484 select ARCH_WANT_OLD_COMPAT_IPC 2485 2486if COMPAT 2487config COMPAT_FOR_U64_ALIGNMENT 2488 def_bool y 2489 2490config SYSVIPC_COMPAT 2491 def_bool y 2492 depends on SYSVIPC 2493 2494config KEYS_COMPAT 2495 def_bool y 2496 depends on KEYS 2497endif 2498 2499endmenu 2500 2501 2502config HAVE_ATOMIC_IOMAP 2503 def_bool y 2504 depends on X86_32 2505 2506config X86_DEV_DMA_OPS 2507 bool 2508 depends on X86_64 || STA2X11 2509 2510config X86_DMA_REMAP 2511 bool 2512 depends on STA2X11 2513 2514config PMC_ATOM 2515 def_bool y 2516 depends on PCI 2517 2518source "net/Kconfig" 2519 2520source "drivers/Kconfig" 2521 2522source "drivers/firmware/Kconfig" 2523 2524source "fs/Kconfig" 2525 2526source "arch/x86/Kconfig.debug" 2527 2528source "security/Kconfig" 2529 2530source "crypto/Kconfig" 2531 2532source "arch/x86/kvm/Kconfig" 2533 2534source "lib/Kconfig" 2535