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