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