1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH != "i386" 5 ---help--- 6 Say yes to build a 64-bit kernel - formerly known as x86_64 7 Say no to build a 32-bit kernel - formerly known as i386 8 9config X86_32 10 def_bool y 11 depends on !64BIT 12 select CLKSRC_I8253 13 select HAVE_UID16 14 15config X86_64 16 def_bool y 17 depends on 64BIT 18 select X86_DEV_DMA_OPS 19 select ARCH_USE_CMPXCHG_LOCKREF 20 21### Arch settings 22config X86 23 def_bool y 24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 25 select ARCH_MIGHT_HAVE_PC_PARPORT 26 select ARCH_MIGHT_HAVE_PC_SERIO 27 select HAVE_AOUT if X86_32 28 select HAVE_UNSTABLE_SCHED_CLOCK 29 select ARCH_SUPPORTS_NUMA_BALANCING 30 select ARCH_SUPPORTS_INT128 if X86_64 31 select ARCH_WANTS_PROT_NUMA_PROT_NONE 32 select HAVE_IDE 33 select HAVE_OPROFILE 34 select HAVE_PCSPKR_PLATFORM 35 select HAVE_PERF_EVENTS 36 select HAVE_IOREMAP_PROT 37 select HAVE_KPROBES 38 select HAVE_MEMBLOCK 39 select HAVE_MEMBLOCK_NODE_MAP 40 select ARCH_DISCARD_MEMBLOCK 41 select ARCH_WANT_OPTIONAL_GPIOLIB 42 select ARCH_WANT_FRAME_POINTERS 43 select HAVE_DMA_ATTRS 44 select HAVE_DMA_CONTIGUOUS if !SWIOTLB 45 select HAVE_KRETPROBES 46 select HAVE_OPTPROBES 47 select HAVE_KPROBES_ON_FTRACE 48 select HAVE_FTRACE_MCOUNT_RECORD 49 select HAVE_FENTRY if X86_64 50 select HAVE_C_RECORDMCOUNT 51 select HAVE_DYNAMIC_FTRACE 52 select HAVE_DYNAMIC_FTRACE_WITH_REGS 53 select HAVE_FUNCTION_TRACER 54 select HAVE_FUNCTION_GRAPH_TRACER 55 select HAVE_FUNCTION_GRAPH_FP_TEST 56 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 57 select HAVE_SYSCALL_TRACEPOINTS 58 select SYSCTL_EXCEPTION_TRACE 59 select HAVE_KVM 60 select HAVE_ARCH_KGDB 61 select HAVE_ARCH_TRACEHOOK 62 select HAVE_GENERIC_DMA_COHERENT if X86_32 63 select HAVE_EFFICIENT_UNALIGNED_ACCESS 64 select USER_STACKTRACE_SUPPORT 65 select HAVE_REGS_AND_STACK_ACCESS_API 66 select HAVE_DMA_API_DEBUG 67 select HAVE_KERNEL_GZIP 68 select HAVE_KERNEL_BZIP2 69 select HAVE_KERNEL_LZMA 70 select HAVE_KERNEL_XZ 71 select HAVE_KERNEL_LZO 72 select HAVE_KERNEL_LZ4 73 select HAVE_HW_BREAKPOINT 74 select HAVE_MIXED_BREAKPOINTS_REGS 75 select PERF_EVENTS 76 select HAVE_PERF_EVENTS_NMI 77 select HAVE_PERF_REGS 78 select HAVE_PERF_USER_STACK_DUMP 79 select HAVE_DEBUG_KMEMLEAK 80 select ANON_INODES 81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 82 select HAVE_CMPXCHG_LOCAL 83 select HAVE_CMPXCHG_DOUBLE 84 select HAVE_ARCH_KMEMCHECK 85 select HAVE_USER_RETURN_NOTIFIER 86 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 87 select HAVE_ARCH_JUMP_LABEL 88 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 89 select SPARSE_IRQ 90 select GENERIC_FIND_FIRST_BIT 91 select GENERIC_IRQ_PROBE 92 select GENERIC_PENDING_IRQ if SMP 93 select GENERIC_IRQ_SHOW 94 select GENERIC_CLOCKEVENTS_MIN_ADJUST 95 select IRQ_FORCED_THREADING 96 select HAVE_BPF_JIT if X86_64 97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 98 select CLKEVT_I8253 99 select ARCH_HAVE_NMI_SAFE_CMPXCHG 100 select GENERIC_IOMAP 101 select DCACHE_WORD_ACCESS 102 select GENERIC_SMP_IDLE_THREAD 103 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 104 select HAVE_ARCH_SECCOMP_FILTER 105 select BUILDTIME_EXTABLE_SORT 106 select GENERIC_CMOS_UPDATE 107 select HAVE_ARCH_SOFT_DIRTY 108 select CLOCKSOURCE_WATCHDOG 109 select GENERIC_CLOCKEVENTS 110 select ARCH_CLOCKSOURCE_DATA 111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 112 select GENERIC_TIME_VSYSCALL 113 select KTIME_SCALAR if X86_32 114 select GENERIC_STRNCPY_FROM_USER 115 select GENERIC_STRNLEN_USER 116 select HAVE_CONTEXT_TRACKING if X86_64 117 select HAVE_IRQ_TIME_ACCOUNTING 118 select VIRT_TO_BUS 119 select MODULES_USE_ELF_REL if X86_32 120 select MODULES_USE_ELF_RELA if X86_64 121 select CLONE_BACKWARDS if X86_32 122 select ARCH_USE_BUILTIN_BSWAP 123 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 124 select OLD_SIGACTION if X86_32 125 select COMPAT_OLD_SIGACTION if IA32_EMULATION 126 select RTC_LIB 127 select HAVE_DEBUG_STACKOVERFLOW 128 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 129 select HAVE_CC_STACKPROTECTOR 130 select GENERIC_CPU_AUTOPROBE 131 132config INSTRUCTION_DECODER 133 def_bool y 134 depends on KPROBES || PERF_EVENTS || UPROBES 135 136config OUTPUT_FORMAT 137 string 138 default "elf32-i386" if X86_32 139 default "elf64-x86-64" if X86_64 140 141config ARCH_DEFCONFIG 142 string 143 default "arch/x86/configs/i386_defconfig" if X86_32 144 default "arch/x86/configs/x86_64_defconfig" if X86_64 145 146config LOCKDEP_SUPPORT 147 def_bool y 148 149config STACKTRACE_SUPPORT 150 def_bool y 151 152config HAVE_LATENCYTOP_SUPPORT 153 def_bool y 154 155config MMU 156 def_bool y 157 158config SBUS 159 bool 160 161config NEED_DMA_MAP_STATE 162 def_bool y 163 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 164 165config NEED_SG_DMA_LENGTH 166 def_bool y 167 168config GENERIC_ISA_DMA 169 def_bool y 170 depends on ISA_DMA_API 171 172config GENERIC_BUG 173 def_bool y 174 depends on BUG 175 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 176 177config GENERIC_BUG_RELATIVE_POINTERS 178 bool 179 180config GENERIC_HWEIGHT 181 def_bool y 182 183config ARCH_MAY_HAVE_PC_FDC 184 def_bool y 185 depends on ISA_DMA_API 186 187config RWSEM_XCHGADD_ALGORITHM 188 def_bool y 189 190config GENERIC_CALIBRATE_DELAY 191 def_bool y 192 193config ARCH_HAS_CPU_RELAX 194 def_bool y 195 196config ARCH_HAS_CACHE_LINE_SIZE 197 def_bool y 198 199config HAVE_SETUP_PER_CPU_AREA 200 def_bool y 201 202config NEED_PER_CPU_EMBED_FIRST_CHUNK 203 def_bool y 204 205config NEED_PER_CPU_PAGE_FIRST_CHUNK 206 def_bool y 207 208config ARCH_HIBERNATION_POSSIBLE 209 def_bool y 210 211config ARCH_SUSPEND_POSSIBLE 212 def_bool y 213 214config ARCH_WANT_HUGE_PMD_SHARE 215 def_bool y 216 217config ARCH_WANT_GENERAL_HUGETLB 218 def_bool y 219 220config ZONE_DMA32 221 bool 222 default X86_64 223 224config AUDIT_ARCH 225 bool 226 default X86_64 227 228config ARCH_SUPPORTS_OPTIMIZED_INLINING 229 def_bool y 230 231config ARCH_SUPPORTS_DEBUG_PAGEALLOC 232 def_bool y 233 234config HAVE_INTEL_TXT 235 def_bool y 236 depends on INTEL_IOMMU && ACPI 237 238config X86_32_SMP 239 def_bool y 240 depends on X86_32 && SMP 241 242config X86_64_SMP 243 def_bool y 244 depends on X86_64 && SMP 245 246config X86_HT 247 def_bool y 248 depends on SMP 249 250config X86_32_LAZY_GS 251 def_bool y 252 depends on X86_32 && !CC_STACKPROTECTOR 253 254config ARCH_HWEIGHT_CFLAGS 255 string 256 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 257 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_64 258 259config ARCH_SUPPORTS_UPROBES 260 def_bool y 261 262source "init/Kconfig" 263source "kernel/Kconfig.freezer" 264 265menu "Processor type and features" 266 267config ZONE_DMA 268 bool "DMA memory allocation support" if EXPERT 269 default y 270 help 271 DMA memory allocation support allows devices with less than 32-bit 272 addressing to allocate within the first 16MB of address space. 273 Disable if no such devices will be used. 274 275 If unsure, say Y. 276 277config SMP 278 bool "Symmetric multi-processing support" 279 ---help--- 280 This enables support for systems with more than one CPU. If you have 281 a system with only one CPU, say N. If you have a system with more 282 than one CPU, say Y. 283 284 If you say N here, the kernel will run on uni- and multiprocessor 285 machines, but will use only one CPU of a multiprocessor machine. If 286 you say Y here, the kernel will run on many, but not all, 287 uniprocessor machines. On a uniprocessor machine, the kernel 288 will run faster if you say N here. 289 290 Note that if you say Y here and choose architecture "586" or 291 "Pentium" under "Processor family", the kernel will not work on 486 292 architectures. Similarly, multiprocessor kernels for the "PPro" 293 architecture may not work on all Pentium based boards. 294 295 People using multiprocessor machines who say Y here should also say 296 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 297 Management" code will be disabled if you say Y here. 298 299 See also <file:Documentation/x86/i386/IO-APIC.txt>, 300 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 301 <http://www.tldp.org/docs.html#howto>. 302 303 If you don't know what to do here, say N. 304 305config X86_X2APIC 306 bool "Support x2apic" 307 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 308 ---help--- 309 This enables x2apic support on CPUs that have this feature. 310 311 This allows 32-bit apic IDs (so it can support very large systems), 312 and accesses the local apic via MSRs not via mmio. 313 314 If you don't know what to do here, say N. 315 316config X86_MPPARSE 317 bool "Enable MPS table" if ACPI || SFI 318 default y 319 depends on X86_LOCAL_APIC 320 ---help--- 321 For old smp systems that do not have proper acpi support. Newer systems 322 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 323 324config X86_BIGSMP 325 bool "Support for big SMP systems with more than 8 CPUs" 326 depends on X86_32 && SMP 327 ---help--- 328 This option is needed for the systems that have more than 8 CPUs 329 330config GOLDFISH 331 def_bool y 332 depends on X86_GOLDFISH 333 334if X86_32 335config X86_EXTENDED_PLATFORM 336 bool "Support for extended (non-PC) x86 platforms" 337 default y 338 ---help--- 339 If you disable this option then the kernel will only support 340 standard PC platforms. (which covers the vast majority of 341 systems out there.) 342 343 If you enable this option then you'll be able to select support 344 for the following (non-PC) 32 bit x86 platforms: 345 Goldfish (Android emulator) 346 AMD Elan 347 RDC R-321x SoC 348 SGI 320/540 (Visual Workstation) 349 STA2X11-based (e.g. Northville) 350 Moorestown MID devices 351 352 If you have one of these systems, or if you want to build a 353 generic distribution kernel, say Y here - otherwise say N. 354endif 355 356if X86_64 357config X86_EXTENDED_PLATFORM 358 bool "Support for extended (non-PC) x86 platforms" 359 default y 360 ---help--- 361 If you disable this option then the kernel will only support 362 standard PC platforms. (which covers the vast majority of 363 systems out there.) 364 365 If you enable this option then you'll be able to select support 366 for the following (non-PC) 64 bit x86 platforms: 367 Numascale NumaChip 368 ScaleMP vSMP 369 SGI Ultraviolet 370 371 If you have one of these systems, or if you want to build a 372 generic distribution kernel, say Y here - otherwise say N. 373endif 374# This is an alphabetically sorted list of 64 bit extended platforms 375# Please maintain the alphabetic order if and when there are additions 376config X86_NUMACHIP 377 bool "Numascale NumaChip" 378 depends on X86_64 379 depends on X86_EXTENDED_PLATFORM 380 depends on NUMA 381 depends on SMP 382 depends on X86_X2APIC 383 depends on PCI_MMCONFIG 384 ---help--- 385 Adds support for Numascale NumaChip large-SMP systems. Needed to 386 enable more than ~168 cores. 387 If you don't have one of these, you should say N here. 388 389config X86_VSMP 390 bool "ScaleMP vSMP" 391 select HYPERVISOR_GUEST 392 select PARAVIRT 393 depends on X86_64 && PCI 394 depends on X86_EXTENDED_PLATFORM 395 depends on SMP 396 ---help--- 397 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 398 supposed to run on these EM64T-based machines. Only choose this option 399 if you have one of these machines. 400 401config X86_UV 402 bool "SGI Ultraviolet" 403 depends on X86_64 404 depends on X86_EXTENDED_PLATFORM 405 depends on NUMA 406 depends on X86_X2APIC 407 ---help--- 408 This option is needed in order to support SGI Ultraviolet systems. 409 If you don't have one of these, you should say N here. 410 411# Following is an alphabetically sorted list of 32 bit extended platforms 412# Please maintain the alphabetic order if and when there are additions 413 414config X86_GOLDFISH 415 bool "Goldfish (Virtual Platform)" 416 depends on X86_32 417 depends on X86_EXTENDED_PLATFORM 418 ---help--- 419 Enable support for the Goldfish virtual platform used primarily 420 for Android development. Unless you are building for the Android 421 Goldfish emulator say N here. 422 423config X86_INTEL_CE 424 bool "CE4100 TV platform" 425 depends on PCI 426 depends on PCI_GODIRECT 427 depends on X86_32 428 depends on X86_EXTENDED_PLATFORM 429 select X86_REBOOTFIXUPS 430 select OF 431 select OF_EARLY_FLATTREE 432 select IRQ_DOMAIN 433 ---help--- 434 Select for the Intel CE media processor (CE4100) SOC. 435 This option compiles in support for the CE4100 SOC for settop 436 boxes and media devices. 437 438config X86_INTEL_MID 439 bool "Intel MID platform support" 440 depends on X86_32 441 depends on X86_EXTENDED_PLATFORM 442 depends on X86_PLATFORM_DEVICES 443 depends on PCI 444 depends on PCI_GOANY 445 depends on X86_IO_APIC 446 select SFI 447 select I2C 448 select DW_APB_TIMER 449 select APB_TIMER 450 select INTEL_SCU_IPC 451 select MFD_INTEL_MSIC 452 ---help--- 453 Select to build a kernel capable of supporting Intel MID (Mobile 454 Internet Device) platform systems which do not have the PCI legacy 455 interfaces. If you are building for a PC class system say N here. 456 457 Intel MID platforms are based on an Intel processor and chipset which 458 consume less power than most of the x86 derivatives. 459 460config X86_INTEL_LPSS 461 bool "Intel Low Power Subsystem Support" 462 depends on ACPI 463 select COMMON_CLK 464 select PINCTRL 465 ---help--- 466 Select to build support for Intel Low Power Subsystem such as 467 found on Intel Lynxpoint PCH. Selecting this option enables 468 things like clock tree (common clock framework) and pincontrol 469 which are needed by the LPSS peripheral drivers. 470 471config X86_RDC321X 472 bool "RDC R-321x SoC" 473 depends on X86_32 474 depends on X86_EXTENDED_PLATFORM 475 select M486 476 select X86_REBOOTFIXUPS 477 ---help--- 478 This option is needed for RDC R-321x system-on-chip, also known 479 as R-8610-(G). 480 If you don't have one of these chips, you should say N here. 481 482config X86_32_NON_STANDARD 483 bool "Support non-standard 32-bit SMP architectures" 484 depends on X86_32 && SMP 485 depends on X86_EXTENDED_PLATFORM 486 ---help--- 487 This option compiles in the bigsmp and STA2X11 default 488 subarchitectures. It is intended for a generic binary 489 kernel. If you select them all, kernel will probe it one by 490 one and will fallback to default. 491 492# Alphabetically sorted list of Non standard 32 bit platforms 493 494config X86_SUPPORTS_MEMORY_FAILURE 495 def_bool y 496 # MCE code calls memory_failure(): 497 depends on X86_MCE 498 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 499 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 500 depends on X86_64 || !SPARSEMEM 501 select ARCH_SUPPORTS_MEMORY_FAILURE 502 503config STA2X11 504 bool "STA2X11 Companion Chip Support" 505 depends on X86_32_NON_STANDARD && PCI 506 select X86_DEV_DMA_OPS 507 select X86_DMA_REMAP 508 select SWIOTLB 509 select MFD_STA2X11 510 select ARCH_REQUIRE_GPIOLIB 511 default n 512 ---help--- 513 This adds support for boards based on the STA2X11 IO-Hub, 514 a.k.a. "ConneXt". The chip is used in place of the standard 515 PC chipset, so all "standard" peripherals are missing. If this 516 option is selected the kernel will still be able to boot on 517 standard PC machines. 518 519config X86_32_IRIS 520 tristate "Eurobraille/Iris poweroff module" 521 depends on X86_32 522 ---help--- 523 The Iris machines from EuroBraille do not have APM or ACPI support 524 to shut themselves down properly. A special I/O sequence is 525 needed to do so, which is what this module does at 526 kernel shutdown. 527 528 This is only for Iris machines from EuroBraille. 529 530 If unused, say N. 531 532config SCHED_OMIT_FRAME_POINTER 533 def_bool y 534 prompt "Single-depth WCHAN output" 535 depends on X86 536 ---help--- 537 Calculate simpler /proc/<PID>/wchan values. If this option 538 is disabled then wchan values will recurse back to the 539 caller function. This provides more accurate wchan values, 540 at the expense of slightly more scheduling overhead. 541 542 If in doubt, say "Y". 543 544menuconfig HYPERVISOR_GUEST 545 bool "Linux guest support" 546 ---help--- 547 Say Y here to enable options for running Linux under various hyper- 548 visors. This option enables basic hypervisor detection and platform 549 setup. 550 551 If you say N, all options in this submenu will be skipped and 552 disabled, and Linux guest support won't be built in. 553 554if HYPERVISOR_GUEST 555 556config PARAVIRT 557 bool "Enable paravirtualization code" 558 ---help--- 559 This changes the kernel so it can modify itself when it is run 560 under a hypervisor, potentially improving performance significantly 561 over full virtualization. However, when run without a hypervisor 562 the kernel is theoretically slower and slightly larger. 563 564config PARAVIRT_DEBUG 565 bool "paravirt-ops debugging" 566 depends on PARAVIRT && DEBUG_KERNEL 567 ---help--- 568 Enable to debug paravirt_ops internals. Specifically, BUG if 569 a paravirt_op is missing when it is called. 570 571config PARAVIRT_SPINLOCKS 572 bool "Paravirtualization layer for spinlocks" 573 depends on PARAVIRT && SMP 574 select UNINLINE_SPIN_UNLOCK 575 ---help--- 576 Paravirtualized spinlocks allow a pvops backend to replace the 577 spinlock implementation with something virtualization-friendly 578 (for example, block the virtual CPU rather than spinning). 579 580 It has a minimal impact on native kernels and gives a nice performance 581 benefit on paravirtualized KVM / Xen kernels. 582 583 If you are unsure how to answer this question, answer Y. 584 585source "arch/x86/xen/Kconfig" 586 587config KVM_GUEST 588 bool "KVM Guest support (including kvmclock)" 589 depends on PARAVIRT 590 select PARAVIRT_CLOCK 591 default y 592 ---help--- 593 This option enables various optimizations for running under the KVM 594 hypervisor. It includes a paravirtualized clock, so that instead 595 of relying on a PIT (or probably other) emulation by the 596 underlying device model, the host provides the guest with 597 timing infrastructure such as time of day, and system time 598 599config KVM_DEBUG_FS 600 bool "Enable debug information for KVM Guests in debugfs" 601 depends on KVM_GUEST && DEBUG_FS 602 default n 603 ---help--- 604 This option enables collection of various statistics for KVM guest. 605 Statistics are displayed in debugfs filesystem. Enabling this option 606 may incur significant overhead. 607 608source "arch/x86/lguest/Kconfig" 609 610config PARAVIRT_TIME_ACCOUNTING 611 bool "Paravirtual steal time accounting" 612 depends on PARAVIRT 613 default n 614 ---help--- 615 Select this option to enable fine granularity task steal time 616 accounting. Time spent executing other tasks in parallel with 617 the current vCPU is discounted from the vCPU power. To account for 618 that, there can be a small performance impact. 619 620 If in doubt, say N here. 621 622config PARAVIRT_CLOCK 623 bool 624 625endif #HYPERVISOR_GUEST 626 627config NO_BOOTMEM 628 def_bool y 629 630config MEMTEST 631 bool "Memtest" 632 ---help--- 633 This option adds a kernel parameter 'memtest', which allows memtest 634 to be set. 635 memtest=0, mean disabled; -- default 636 memtest=1, mean do 1 test pattern; 637 ... 638 memtest=4, mean do 4 test patterns. 639 If you are unsure how to answer this question, answer N. 640 641source "arch/x86/Kconfig.cpu" 642 643config HPET_TIMER 644 def_bool X86_64 645 prompt "HPET Timer Support" if X86_32 646 ---help--- 647 Use the IA-PC HPET (High Precision Event Timer) to manage 648 time in preference to the PIT and RTC, if a HPET is 649 present. 650 HPET is the next generation timer replacing legacy 8254s. 651 The HPET provides a stable time base on SMP 652 systems, unlike the TSC, but it is more expensive to access, 653 as it is off-chip. You can find the HPET spec at 654 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 655 656 You can safely choose Y here. However, HPET will only be 657 activated if the platform and the BIOS support this feature. 658 Otherwise the 8254 will be used for timing services. 659 660 Choose N to continue using the legacy 8254 timer. 661 662config HPET_EMULATE_RTC 663 def_bool y 664 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 665 666config APB_TIMER 667 def_bool y if X86_INTEL_MID 668 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 669 select DW_APB_TIMER 670 depends on X86_INTEL_MID && SFI 671 help 672 APB timer is the replacement for 8254, HPET on X86 MID platforms. 673 The APBT provides a stable time base on SMP 674 systems, unlike the TSC, but it is more expensive to access, 675 as it is off-chip. APB timers are always running regardless of CPU 676 C states, they are used as per CPU clockevent device when possible. 677 678# Mark as expert because too many people got it wrong. 679# The code disables itself when not needed. 680config DMI 681 default y 682 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 683 bool "Enable DMI scanning" if EXPERT 684 ---help--- 685 Enabled scanning of DMI to identify machine quirks. Say Y 686 here unless you have verified that your setup is not 687 affected by entries in the DMI blacklist. Required by PNP 688 BIOS code. 689 690config GART_IOMMU 691 bool "Old AMD GART IOMMU support" 692 select SWIOTLB 693 depends on X86_64 && PCI && AMD_NB 694 ---help--- 695 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 696 GART based hardware IOMMUs. 697 698 The GART supports full DMA access for devices with 32-bit access 699 limitations, on systems with more than 3 GB. This is usually needed 700 for USB, sound, many IDE/SATA chipsets and some other devices. 701 702 Newer systems typically have a modern AMD IOMMU, supported via 703 the CONFIG_AMD_IOMMU=y config option. 704 705 In normal configurations this driver is only active when needed: 706 there's more than 3 GB of memory and the system contains a 707 32-bit limited device. 708 709 If unsure, say Y. 710 711config CALGARY_IOMMU 712 bool "IBM Calgary IOMMU support" 713 select SWIOTLB 714 depends on X86_64 && PCI 715 ---help--- 716 Support for hardware IOMMUs in IBM's xSeries x366 and x460 717 systems. Needed to run systems with more than 3GB of memory 718 properly with 32-bit PCI devices that do not support DAC 719 (Double Address Cycle). Calgary also supports bus level 720 isolation, where all DMAs pass through the IOMMU. This 721 prevents them from going anywhere except their intended 722 destination. This catches hard-to-find kernel bugs and 723 mis-behaving drivers and devices that do not use the DMA-API 724 properly to set up their DMA buffers. The IOMMU can be 725 turned off at boot time with the iommu=off parameter. 726 Normally the kernel will make the right choice by itself. 727 If unsure, say Y. 728 729config CALGARY_IOMMU_ENABLED_BY_DEFAULT 730 def_bool y 731 prompt "Should Calgary be enabled by default?" 732 depends on CALGARY_IOMMU 733 ---help--- 734 Should Calgary be enabled by default? if you choose 'y', Calgary 735 will be used (if it exists). If you choose 'n', Calgary will not be 736 used even if it exists. If you choose 'n' and would like to use 737 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 738 If unsure, say Y. 739 740# need this always selected by IOMMU for the VIA workaround 741config SWIOTLB 742 def_bool y if X86_64 743 ---help--- 744 Support for software bounce buffers used on x86-64 systems 745 which don't have a hardware IOMMU. Using this PCI devices 746 which can only access 32-bits of memory can be used on systems 747 with more than 3 GB of memory. 748 If unsure, say Y. 749 750config IOMMU_HELPER 751 def_bool y 752 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 753 754config MAXSMP 755 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 756 depends on X86_64 && SMP && DEBUG_KERNEL 757 select CPUMASK_OFFSTACK 758 ---help--- 759 Enable maximum number of CPUS and NUMA Nodes for this architecture. 760 If unsure, say N. 761 762config NR_CPUS 763 int "Maximum number of CPUs" if SMP && !MAXSMP 764 range 2 8 if SMP && X86_32 && !X86_BIGSMP 765 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 766 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 767 default "1" if !SMP 768 default "8192" if MAXSMP 769 default "32" if SMP && X86_BIGSMP 770 default "8" if SMP 771 ---help--- 772 This allows you to specify the maximum number of CPUs which this 773 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 774 supported value is 4096, otherwise the maximum value is 512. The 775 minimum value which makes sense is 2. 776 777 This is purely to save memory - each supported CPU adds 778 approximately eight kilobytes to the kernel image. 779 780config SCHED_SMT 781 bool "SMT (Hyperthreading) scheduler support" 782 depends on X86_HT 783 ---help--- 784 SMT scheduler support improves the CPU scheduler's decision making 785 when dealing with Intel Pentium 4 chips with HyperThreading at a 786 cost of slightly increased overhead in some places. If unsure say 787 N here. 788 789config SCHED_MC 790 def_bool y 791 prompt "Multi-core scheduler support" 792 depends on X86_HT 793 ---help--- 794 Multi-core scheduler support improves the CPU scheduler's decision 795 making when dealing with multi-core CPU chips at a cost of slightly 796 increased overhead in some places. If unsure say N here. 797 798source "kernel/Kconfig.preempt" 799 800config X86_UP_APIC 801 bool "Local APIC support on uniprocessors" 802 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 803 ---help--- 804 A local APIC (Advanced Programmable Interrupt Controller) is an 805 integrated interrupt controller in the CPU. If you have a single-CPU 806 system which has a processor with a local APIC, you can say Y here to 807 enable and use it. If you say Y here even though your machine doesn't 808 have a local APIC, then the kernel will still run with no slowdown at 809 all. The local APIC supports CPU-generated self-interrupts (timer, 810 performance counters), and the NMI watchdog which detects hard 811 lockups. 812 813config X86_UP_IOAPIC 814 bool "IO-APIC support on uniprocessors" 815 depends on X86_UP_APIC 816 ---help--- 817 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 818 SMP-capable replacement for PC-style interrupt controllers. Most 819 SMP systems and many recent uniprocessor systems have one. 820 821 If you have a single-CPU system with an IO-APIC, you can say Y here 822 to use it. If you say Y here even though your machine doesn't have 823 an IO-APIC, then the kernel will still run with no slowdown at all. 824 825config X86_LOCAL_APIC 826 def_bool y 827 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 828 829config X86_IO_APIC 830 def_bool y 831 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 832 833config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 834 bool "Reroute for broken boot IRQs" 835 depends on X86_IO_APIC 836 ---help--- 837 This option enables a workaround that fixes a source of 838 spurious interrupts. This is recommended when threaded 839 interrupt handling is used on systems where the generation of 840 superfluous "boot interrupts" cannot be disabled. 841 842 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 843 entry in the chipset's IO-APIC is masked (as, e.g. the RT 844 kernel does during interrupt handling). On chipsets where this 845 boot IRQ generation cannot be disabled, this workaround keeps 846 the original IRQ line masked so that only the equivalent "boot 847 IRQ" is delivered to the CPUs. The workaround also tells the 848 kernel to set up the IRQ handler on the boot IRQ line. In this 849 way only one interrupt is delivered to the kernel. Otherwise 850 the spurious second interrupt may cause the kernel to bring 851 down (vital) interrupt lines. 852 853 Only affects "broken" chipsets. Interrupt sharing may be 854 increased on these systems. 855 856config X86_MCE 857 bool "Machine Check / overheating reporting" 858 default y 859 ---help--- 860 Machine Check support allows the processor to notify the 861 kernel if it detects a problem (e.g. overheating, data corruption). 862 The action the kernel takes depends on the severity of the problem, 863 ranging from warning messages to halting the machine. 864 865config X86_MCE_INTEL 866 def_bool y 867 prompt "Intel MCE features" 868 depends on X86_MCE && X86_LOCAL_APIC 869 ---help--- 870 Additional support for intel specific MCE features such as 871 the thermal monitor. 872 873config X86_MCE_AMD 874 def_bool y 875 prompt "AMD MCE features" 876 depends on X86_MCE && X86_LOCAL_APIC 877 ---help--- 878 Additional support for AMD specific MCE features such as 879 the DRAM Error Threshold. 880 881config X86_ANCIENT_MCE 882 bool "Support for old Pentium 5 / WinChip machine checks" 883 depends on X86_32 && X86_MCE 884 ---help--- 885 Include support for machine check handling on old Pentium 5 or WinChip 886 systems. These typically need to be enabled explicitly on the command 887 line. 888 889config X86_MCE_THRESHOLD 890 depends on X86_MCE_AMD || X86_MCE_INTEL 891 def_bool y 892 893config X86_MCE_INJECT 894 depends on X86_MCE 895 tristate "Machine check injector support" 896 ---help--- 897 Provide support for injecting machine checks for testing purposes. 898 If you don't know what a machine check is and you don't do kernel 899 QA it is safe to say n. 900 901config X86_THERMAL_VECTOR 902 def_bool y 903 depends on X86_MCE_INTEL 904 905config VM86 906 bool "Enable VM86 support" if EXPERT 907 default y 908 depends on X86_32 909 ---help--- 910 This option is required by programs like DOSEMU to run 16-bit legacy 911 code on X86 processors. It also may be needed by software like 912 XFree86 to initialize some video cards via BIOS. Disabling this 913 option saves about 6k. 914 915config TOSHIBA 916 tristate "Toshiba Laptop support" 917 depends on X86_32 918 ---help--- 919 This adds a driver to safely access the System Management Mode of 920 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 921 not work on models with a Phoenix BIOS. The System Management Mode 922 is used to set the BIOS and power saving options on Toshiba portables. 923 924 For information on utilities to make use of this driver see the 925 Toshiba Linux utilities web site at: 926 <http://www.buzzard.org.uk/toshiba/>. 927 928 Say Y if you intend to run this kernel on a Toshiba portable. 929 Say N otherwise. 930 931config I8K 932 tristate "Dell laptop support" 933 select HWMON 934 ---help--- 935 This adds a driver to safely access the System Management Mode 936 of the CPU on the Dell Inspiron 8000. The System Management Mode 937 is used to read cpu temperature and cooling fan status and to 938 control the fans on the I8K portables. 939 940 This driver has been tested only on the Inspiron 8000 but it may 941 also work with other Dell laptops. You can force loading on other 942 models by passing the parameter `force=1' to the module. Use at 943 your own risk. 944 945 For information on utilities to make use of this driver see the 946 I8K Linux utilities web site at: 947 <http://people.debian.org/~dz/i8k/> 948 949 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 950 Say N otherwise. 951 952config X86_REBOOTFIXUPS 953 bool "Enable X86 board specific fixups for reboot" 954 depends on X86_32 955 ---help--- 956 This enables chipset and/or board specific fixups to be done 957 in order to get reboot to work correctly. This is only needed on 958 some combinations of hardware and BIOS. The symptom, for which 959 this config is intended, is when reboot ends with a stalled/hung 960 system. 961 962 Currently, the only fixup is for the Geode machines using 963 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 964 965 Say Y if you want to enable the fixup. Currently, it's safe to 966 enable this option even if you don't need it. 967 Say N otherwise. 968 969config MICROCODE 970 tristate "CPU microcode loading support" 971 depends on CPU_SUP_AMD || CPU_SUP_INTEL 972 select FW_LOADER 973 ---help--- 974 975 If you say Y here, you will be able to update the microcode on 976 certain Intel and AMD processors. The Intel support is for the 977 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 978 Xeon etc. The AMD support is for families 0x10 and later. You will 979 obviously need the actual microcode binary data itself which is not 980 shipped with the Linux kernel. 981 982 This option selects the general module only, you need to select 983 at least one vendor specific module as well. 984 985 To compile this driver as a module, choose M here: the module 986 will be called microcode. 987 988config MICROCODE_INTEL 989 bool "Intel microcode loading support" 990 depends on MICROCODE 991 default MICROCODE 992 select FW_LOADER 993 ---help--- 994 This options enables microcode patch loading support for Intel 995 processors. 996 997 For the current Intel microcode data package go to 998 <https://downloadcenter.intel.com> and search for 999 'Linux Processor Microcode Data File'. 1000 1001config MICROCODE_AMD 1002 bool "AMD microcode loading support" 1003 depends on MICROCODE 1004 select FW_LOADER 1005 ---help--- 1006 If you select this option, microcode patch loading support for AMD 1007 processors will be enabled. 1008 1009config MICROCODE_OLD_INTERFACE 1010 def_bool y 1011 depends on MICROCODE 1012 1013config MICROCODE_INTEL_EARLY 1014 def_bool n 1015 1016config MICROCODE_AMD_EARLY 1017 def_bool n 1018 1019config MICROCODE_EARLY 1020 bool "Early load microcode" 1021 depends on MICROCODE=y && BLK_DEV_INITRD 1022 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1023 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1024 default y 1025 help 1026 This option provides functionality to read additional microcode data 1027 at the beginning of initrd image. The data tells kernel to load 1028 microcode to CPU's as early as possible. No functional change if no 1029 microcode data is glued to the initrd, therefore it's safe to say Y. 1030 1031config X86_MSR 1032 tristate "/dev/cpu/*/msr - Model-specific register support" 1033 ---help--- 1034 This device gives privileged processes access to the x86 1035 Model-Specific Registers (MSRs). It is a character device with 1036 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1037 MSR accesses are directed to a specific CPU on multi-processor 1038 systems. 1039 1040config X86_CPUID 1041 tristate "/dev/cpu/*/cpuid - CPU information support" 1042 ---help--- 1043 This device gives processes access to the x86 CPUID instruction to 1044 be executed on a specific processor. It is a character device 1045 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1046 /dev/cpu/31/cpuid. 1047 1048choice 1049 prompt "High Memory Support" 1050 default HIGHMEM4G 1051 depends on X86_32 1052 1053config NOHIGHMEM 1054 bool "off" 1055 ---help--- 1056 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1057 However, the address space of 32-bit x86 processors is only 4 1058 Gigabytes large. That means that, if you have a large amount of 1059 physical memory, not all of it can be "permanently mapped" by the 1060 kernel. The physical memory that's not permanently mapped is called 1061 "high memory". 1062 1063 If you are compiling a kernel which will never run on a machine with 1064 more than 1 Gigabyte total physical RAM, answer "off" here (default 1065 choice and suitable for most users). This will result in a "3GB/1GB" 1066 split: 3GB are mapped so that each process sees a 3GB virtual memory 1067 space and the remaining part of the 4GB virtual memory space is used 1068 by the kernel to permanently map as much physical memory as 1069 possible. 1070 1071 If the machine has between 1 and 4 Gigabytes physical RAM, then 1072 answer "4GB" here. 1073 1074 If more than 4 Gigabytes is used then answer "64GB" here. This 1075 selection turns Intel PAE (Physical Address Extension) mode on. 1076 PAE implements 3-level paging on IA32 processors. PAE is fully 1077 supported by Linux, PAE mode is implemented on all recent Intel 1078 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1079 then the kernel will not boot on CPUs that don't support PAE! 1080 1081 The actual amount of total physical memory will either be 1082 auto detected or can be forced by using a kernel command line option 1083 such as "mem=256M". (Try "man bootparam" or see the documentation of 1084 your boot loader (lilo or loadlin) about how to pass options to the 1085 kernel at boot time.) 1086 1087 If unsure, say "off". 1088 1089config HIGHMEM4G 1090 bool "4GB" 1091 ---help--- 1092 Select this if you have a 32-bit processor and between 1 and 4 1093 gigabytes of physical RAM. 1094 1095config HIGHMEM64G 1096 bool "64GB" 1097 depends on !M486 1098 select X86_PAE 1099 ---help--- 1100 Select this if you have a 32-bit processor and more than 4 1101 gigabytes of physical RAM. 1102 1103endchoice 1104 1105choice 1106 prompt "Memory split" if EXPERT 1107 default VMSPLIT_3G 1108 depends on X86_32 1109 ---help--- 1110 Select the desired split between kernel and user memory. 1111 1112 If the address range available to the kernel is less than the 1113 physical memory installed, the remaining memory will be available 1114 as "high memory". Accessing high memory is a little more costly 1115 than low memory, as it needs to be mapped into the kernel first. 1116 Note that increasing the kernel address space limits the range 1117 available to user programs, making the address space there 1118 tighter. Selecting anything other than the default 3G/1G split 1119 will also likely make your kernel incompatible with binary-only 1120 kernel modules. 1121 1122 If you are not absolutely sure what you are doing, leave this 1123 option alone! 1124 1125 config VMSPLIT_3G 1126 bool "3G/1G user/kernel split" 1127 config VMSPLIT_3G_OPT 1128 depends on !X86_PAE 1129 bool "3G/1G user/kernel split (for full 1G low memory)" 1130 config VMSPLIT_2G 1131 bool "2G/2G user/kernel split" 1132 config VMSPLIT_2G_OPT 1133 depends on !X86_PAE 1134 bool "2G/2G user/kernel split (for full 2G low memory)" 1135 config VMSPLIT_1G 1136 bool "1G/3G user/kernel split" 1137endchoice 1138 1139config PAGE_OFFSET 1140 hex 1141 default 0xB0000000 if VMSPLIT_3G_OPT 1142 default 0x80000000 if VMSPLIT_2G 1143 default 0x78000000 if VMSPLIT_2G_OPT 1144 default 0x40000000 if VMSPLIT_1G 1145 default 0xC0000000 1146 depends on X86_32 1147 1148config HIGHMEM 1149 def_bool y 1150 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1151 1152config X86_PAE 1153 bool "PAE (Physical Address Extension) Support" 1154 depends on X86_32 && !HIGHMEM4G 1155 ---help--- 1156 PAE is required for NX support, and furthermore enables 1157 larger swapspace support for non-overcommit purposes. It 1158 has the cost of more pagetable lookup overhead, and also 1159 consumes more pagetable space per process. 1160 1161config ARCH_PHYS_ADDR_T_64BIT 1162 def_bool y 1163 depends on X86_64 || X86_PAE 1164 1165config ARCH_DMA_ADDR_T_64BIT 1166 def_bool y 1167 depends on X86_64 || HIGHMEM64G 1168 1169config DIRECT_GBPAGES 1170 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1171 default y 1172 depends on X86_64 1173 ---help--- 1174 Allow the kernel linear mapping to use 1GB pages on CPUs that 1175 support it. This can improve the kernel's performance a tiny bit by 1176 reducing TLB pressure. If in doubt, say "Y". 1177 1178# Common NUMA Features 1179config NUMA 1180 bool "Numa Memory Allocation and Scheduler Support" 1181 depends on SMP 1182 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1183 default y if X86_BIGSMP 1184 ---help--- 1185 Enable NUMA (Non Uniform Memory Access) support. 1186 1187 The kernel will try to allocate memory used by a CPU on the 1188 local memory controller of the CPU and add some more 1189 NUMA awareness to the kernel. 1190 1191 For 64-bit this is recommended if the system is Intel Core i7 1192 (or later), AMD Opteron, or EM64T NUMA. 1193 1194 For 32-bit this is only needed if you boot a 32-bit 1195 kernel on a 64-bit NUMA platform. 1196 1197 Otherwise, you should say N. 1198 1199config AMD_NUMA 1200 def_bool y 1201 prompt "Old style AMD Opteron NUMA detection" 1202 depends on X86_64 && NUMA && PCI 1203 ---help--- 1204 Enable AMD NUMA node topology detection. You should say Y here if 1205 you have a multi processor AMD system. This uses an old method to 1206 read the NUMA configuration directly from the builtin Northbridge 1207 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1208 which also takes priority if both are compiled in. 1209 1210config X86_64_ACPI_NUMA 1211 def_bool y 1212 prompt "ACPI NUMA detection" 1213 depends on X86_64 && NUMA && ACPI && PCI 1214 select ACPI_NUMA 1215 ---help--- 1216 Enable ACPI SRAT based node topology detection. 1217 1218# Some NUMA nodes have memory ranges that span 1219# other nodes. Even though a pfn is valid and 1220# between a node's start and end pfns, it may not 1221# reside on that node. See memmap_init_zone() 1222# for details. 1223config NODES_SPAN_OTHER_NODES 1224 def_bool y 1225 depends on X86_64_ACPI_NUMA 1226 1227config NUMA_EMU 1228 bool "NUMA emulation" 1229 depends on NUMA 1230 ---help--- 1231 Enable NUMA emulation. A flat machine will be split 1232 into virtual nodes when booted with "numa=fake=N", where N is the 1233 number of nodes. This is only useful for debugging. 1234 1235config NODES_SHIFT 1236 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1237 range 1 10 1238 default "10" if MAXSMP 1239 default "6" if X86_64 1240 default "3" 1241 depends on NEED_MULTIPLE_NODES 1242 ---help--- 1243 Specify the maximum number of NUMA Nodes available on the target 1244 system. Increases memory reserved to accommodate various tables. 1245 1246config ARCH_HAVE_MEMORY_PRESENT 1247 def_bool y 1248 depends on X86_32 && DISCONTIGMEM 1249 1250config NEED_NODE_MEMMAP_SIZE 1251 def_bool y 1252 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1253 1254config ARCH_FLATMEM_ENABLE 1255 def_bool y 1256 depends on X86_32 && !NUMA 1257 1258config ARCH_DISCONTIGMEM_ENABLE 1259 def_bool y 1260 depends on NUMA && X86_32 1261 1262config ARCH_DISCONTIGMEM_DEFAULT 1263 def_bool y 1264 depends on NUMA && X86_32 1265 1266config ARCH_SPARSEMEM_ENABLE 1267 def_bool y 1268 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1269 select SPARSEMEM_STATIC if X86_32 1270 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1271 1272config ARCH_SPARSEMEM_DEFAULT 1273 def_bool y 1274 depends on X86_64 1275 1276config ARCH_SELECT_MEMORY_MODEL 1277 def_bool y 1278 depends on ARCH_SPARSEMEM_ENABLE 1279 1280config ARCH_MEMORY_PROBE 1281 bool "Enable sysfs memory/probe interface" 1282 depends on X86_64 && MEMORY_HOTPLUG 1283 help 1284 This option enables a sysfs memory/probe interface for testing. 1285 See Documentation/memory-hotplug.txt for more information. 1286 If you are unsure how to answer this question, answer N. 1287 1288config ARCH_PROC_KCORE_TEXT 1289 def_bool y 1290 depends on X86_64 && PROC_KCORE 1291 1292config ILLEGAL_POINTER_VALUE 1293 hex 1294 default 0 if X86_32 1295 default 0xdead000000000000 if X86_64 1296 1297source "mm/Kconfig" 1298 1299config HIGHPTE 1300 bool "Allocate 3rd-level pagetables from highmem" 1301 depends on HIGHMEM 1302 ---help--- 1303 The VM uses one page table entry for each page of physical memory. 1304 For systems with a lot of RAM, this can be wasteful of precious 1305 low memory. Setting this option will put user-space page table 1306 entries in high memory. 1307 1308config X86_CHECK_BIOS_CORRUPTION 1309 bool "Check for low memory corruption" 1310 ---help--- 1311 Periodically check for memory corruption in low memory, which 1312 is suspected to be caused by BIOS. Even when enabled in the 1313 configuration, it is disabled at runtime. Enable it by 1314 setting "memory_corruption_check=1" on the kernel command 1315 line. By default it scans the low 64k of memory every 60 1316 seconds; see the memory_corruption_check_size and 1317 memory_corruption_check_period parameters in 1318 Documentation/kernel-parameters.txt to adjust this. 1319 1320 When enabled with the default parameters, this option has 1321 almost no overhead, as it reserves a relatively small amount 1322 of memory and scans it infrequently. It both detects corruption 1323 and prevents it from affecting the running system. 1324 1325 It is, however, intended as a diagnostic tool; if repeatable 1326 BIOS-originated corruption always affects the same memory, 1327 you can use memmap= to prevent the kernel from using that 1328 memory. 1329 1330config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1331 bool "Set the default setting of memory_corruption_check" 1332 depends on X86_CHECK_BIOS_CORRUPTION 1333 default y 1334 ---help--- 1335 Set whether the default state of memory_corruption_check is 1336 on or off. 1337 1338config X86_RESERVE_LOW 1339 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1340 default 64 1341 range 4 640 1342 ---help--- 1343 Specify the amount of low memory to reserve for the BIOS. 1344 1345 The first page contains BIOS data structures that the kernel 1346 must not use, so that page must always be reserved. 1347 1348 By default we reserve the first 64K of physical RAM, as a 1349 number of BIOSes are known to corrupt that memory range 1350 during events such as suspend/resume or monitor cable 1351 insertion, so it must not be used by the kernel. 1352 1353 You can set this to 4 if you are absolutely sure that you 1354 trust the BIOS to get all its memory reservations and usages 1355 right. If you know your BIOS have problems beyond the 1356 default 64K area, you can set this to 640 to avoid using the 1357 entire low memory range. 1358 1359 If you have doubts about the BIOS (e.g. suspend/resume does 1360 not work or there's kernel crashes after certain hardware 1361 hotplug events) then you might want to enable 1362 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1363 typical corruption patterns. 1364 1365 Leave this to the default value of 64 if you are unsure. 1366 1367config MATH_EMULATION 1368 bool 1369 prompt "Math emulation" if X86_32 1370 ---help--- 1371 Linux can emulate a math coprocessor (used for floating point 1372 operations) if you don't have one. 486DX and Pentium processors have 1373 a math coprocessor built in, 486SX and 386 do not, unless you added 1374 a 487DX or 387, respectively. (The messages during boot time can 1375 give you some hints here ["man dmesg"].) Everyone needs either a 1376 coprocessor or this emulation. 1377 1378 If you don't have a math coprocessor, you need to say Y here; if you 1379 say Y here even though you have a coprocessor, the coprocessor will 1380 be used nevertheless. (This behavior can be changed with the kernel 1381 command line option "no387", which comes handy if your coprocessor 1382 is broken. Try "man bootparam" or see the documentation of your boot 1383 loader (lilo or loadlin) about how to pass options to the kernel at 1384 boot time.) This means that it is a good idea to say Y here if you 1385 intend to use this kernel on different machines. 1386 1387 More information about the internals of the Linux math coprocessor 1388 emulation can be found in <file:arch/x86/math-emu/README>. 1389 1390 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1391 kernel, it won't hurt. 1392 1393config MTRR 1394 def_bool y 1395 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1396 ---help--- 1397 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1398 the Memory Type Range Registers (MTRRs) may be used to control 1399 processor access to memory ranges. This is most useful if you have 1400 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1401 allows bus write transfers to be combined into a larger transfer 1402 before bursting over the PCI/AGP bus. This can increase performance 1403 of image write operations 2.5 times or more. Saying Y here creates a 1404 /proc/mtrr file which may be used to manipulate your processor's 1405 MTRRs. Typically the X server should use this. 1406 1407 This code has a reasonably generic interface so that similar 1408 control registers on other processors can be easily supported 1409 as well: 1410 1411 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1412 Registers (ARRs) which provide a similar functionality to MTRRs. For 1413 these, the ARRs are used to emulate the MTRRs. 1414 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1415 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1416 write-combining. All of these processors are supported by this code 1417 and it makes sense to say Y here if you have one of them. 1418 1419 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1420 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1421 can lead to all sorts of problems, so it's good to say Y here. 1422 1423 You can safely say Y even if your machine doesn't have MTRRs, you'll 1424 just add about 9 KB to your kernel. 1425 1426 See <file:Documentation/x86/mtrr.txt> for more information. 1427 1428config MTRR_SANITIZER 1429 def_bool y 1430 prompt "MTRR cleanup support" 1431 depends on MTRR 1432 ---help--- 1433 Convert MTRR layout from continuous to discrete, so X drivers can 1434 add writeback entries. 1435 1436 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1437 The largest mtrr entry size for a continuous block can be set with 1438 mtrr_chunk_size. 1439 1440 If unsure, say Y. 1441 1442config MTRR_SANITIZER_ENABLE_DEFAULT 1443 int "MTRR cleanup enable value (0-1)" 1444 range 0 1 1445 default "0" 1446 depends on MTRR_SANITIZER 1447 ---help--- 1448 Enable mtrr cleanup default value 1449 1450config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1451 int "MTRR cleanup spare reg num (0-7)" 1452 range 0 7 1453 default "1" 1454 depends on MTRR_SANITIZER 1455 ---help--- 1456 mtrr cleanup spare entries default, it can be changed via 1457 mtrr_spare_reg_nr=N on the kernel command line. 1458 1459config X86_PAT 1460 def_bool y 1461 prompt "x86 PAT support" if EXPERT 1462 depends on MTRR 1463 ---help--- 1464 Use PAT attributes to setup page level cache control. 1465 1466 PATs are the modern equivalents of MTRRs and are much more 1467 flexible than MTRRs. 1468 1469 Say N here if you see bootup problems (boot crash, boot hang, 1470 spontaneous reboots) or a non-working video driver. 1471 1472 If unsure, say Y. 1473 1474config ARCH_USES_PG_UNCACHED 1475 def_bool y 1476 depends on X86_PAT 1477 1478config ARCH_RANDOM 1479 def_bool y 1480 prompt "x86 architectural random number generator" if EXPERT 1481 ---help--- 1482 Enable the x86 architectural RDRAND instruction 1483 (Intel Bull Mountain technology) to generate random numbers. 1484 If supported, this is a high bandwidth, cryptographically 1485 secure hardware random number generator. 1486 1487config X86_SMAP 1488 def_bool y 1489 prompt "Supervisor Mode Access Prevention" if EXPERT 1490 ---help--- 1491 Supervisor Mode Access Prevention (SMAP) is a security 1492 feature in newer Intel processors. There is a small 1493 performance cost if this enabled and turned on; there is 1494 also a small increase in the kernel size if this is enabled. 1495 1496 If unsure, say Y. 1497 1498config EFI 1499 bool "EFI runtime service support" 1500 depends on ACPI 1501 select UCS2_STRING 1502 ---help--- 1503 This enables the kernel to use EFI runtime services that are 1504 available (such as the EFI variable services). 1505 1506 This option is only useful on systems that have EFI firmware. 1507 In addition, you should use the latest ELILO loader available 1508 at <http://elilo.sourceforge.net> in order to take advantage 1509 of EFI runtime services. However, even with this option, the 1510 resultant kernel should continue to boot on existing non-EFI 1511 platforms. 1512 1513config EFI_STUB 1514 bool "EFI stub support" 1515 depends on EFI 1516 ---help--- 1517 This kernel feature allows a bzImage to be loaded directly 1518 by EFI firmware without the use of a bootloader. 1519 1520 See Documentation/efi-stub.txt for more information. 1521 1522config EFI_MIXED 1523 bool "EFI mixed-mode support" 1524 depends on EFI_STUB && X86_64 1525 ---help--- 1526 Enabling this feature allows a 64-bit kernel to be booted 1527 on a 32-bit firmware, provided that your CPU supports 64-bit 1528 mode. 1529 1530 Note that it is not possible to boot a mixed-mode enabled 1531 kernel via the EFI boot stub - a bootloader that supports 1532 the EFI handover protocol must be used. 1533 1534 If unsure, say N. 1535 1536config SECCOMP 1537 def_bool y 1538 prompt "Enable seccomp to safely compute untrusted bytecode" 1539 ---help--- 1540 This kernel feature is useful for number crunching applications 1541 that may need to compute untrusted bytecode during their 1542 execution. By using pipes or other transports made available to 1543 the process as file descriptors supporting the read/write 1544 syscalls, it's possible to isolate those applications in 1545 their own address space using seccomp. Once seccomp is 1546 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1547 and the task is only allowed to execute a few safe syscalls 1548 defined by each seccomp mode. 1549 1550 If unsure, say Y. Only embedded should say N here. 1551 1552source kernel/Kconfig.hz 1553 1554config KEXEC 1555 bool "kexec system call" 1556 ---help--- 1557 kexec is a system call that implements the ability to shutdown your 1558 current kernel, and to start another kernel. It is like a reboot 1559 but it is independent of the system firmware. And like a reboot 1560 you can start any kernel with it, not just Linux. 1561 1562 The name comes from the similarity to the exec system call. 1563 1564 It is an ongoing process to be certain the hardware in a machine 1565 is properly shutdown, so do not be surprised if this code does not 1566 initially work for you. As of this writing the exact hardware 1567 interface is strongly in flux, so no good recommendation can be 1568 made. 1569 1570config CRASH_DUMP 1571 bool "kernel crash dumps" 1572 depends on X86_64 || (X86_32 && HIGHMEM) 1573 ---help--- 1574 Generate crash dump after being started by kexec. 1575 This should be normally only set in special crash dump kernels 1576 which are loaded in the main kernel with kexec-tools into 1577 a specially reserved region and then later executed after 1578 a crash by kdump/kexec. The crash dump kernel must be compiled 1579 to a memory address not used by the main kernel or BIOS using 1580 PHYSICAL_START, or it must be built as a relocatable image 1581 (CONFIG_RELOCATABLE=y). 1582 For more details see Documentation/kdump/kdump.txt 1583 1584config KEXEC_JUMP 1585 bool "kexec jump" 1586 depends on KEXEC && HIBERNATION 1587 ---help--- 1588 Jump between original kernel and kexeced kernel and invoke 1589 code in physical address mode via KEXEC 1590 1591config PHYSICAL_START 1592 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1593 default "0x1000000" 1594 ---help--- 1595 This gives the physical address where the kernel is loaded. 1596 1597 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1598 bzImage will decompress itself to above physical address and 1599 run from there. Otherwise, bzImage will run from the address where 1600 it has been loaded by the boot loader and will ignore above physical 1601 address. 1602 1603 In normal kdump cases one does not have to set/change this option 1604 as now bzImage can be compiled as a completely relocatable image 1605 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1606 address. This option is mainly useful for the folks who don't want 1607 to use a bzImage for capturing the crash dump and want to use a 1608 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1609 to be specifically compiled to run from a specific memory area 1610 (normally a reserved region) and this option comes handy. 1611 1612 So if you are using bzImage for capturing the crash dump, 1613 leave the value here unchanged to 0x1000000 and set 1614 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1615 for capturing the crash dump change this value to start of 1616 the reserved region. In other words, it can be set based on 1617 the "X" value as specified in the "crashkernel=YM@XM" 1618 command line boot parameter passed to the panic-ed 1619 kernel. Please take a look at Documentation/kdump/kdump.txt 1620 for more details about crash dumps. 1621 1622 Usage of bzImage for capturing the crash dump is recommended as 1623 one does not have to build two kernels. Same kernel can be used 1624 as production kernel and capture kernel. Above option should have 1625 gone away after relocatable bzImage support is introduced. But it 1626 is present because there are users out there who continue to use 1627 vmlinux for dump capture. This option should go away down the 1628 line. 1629 1630 Don't change this unless you know what you are doing. 1631 1632config RELOCATABLE 1633 bool "Build a relocatable kernel" 1634 default y 1635 ---help--- 1636 This builds a kernel image that retains relocation information 1637 so it can be loaded someplace besides the default 1MB. 1638 The relocations tend to make the kernel binary about 10% larger, 1639 but are discarded at runtime. 1640 1641 One use is for the kexec on panic case where the recovery kernel 1642 must live at a different physical address than the primary 1643 kernel. 1644 1645 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1646 it has been loaded at and the compile time physical address 1647 (CONFIG_PHYSICAL_START) is used as the minimum location. 1648 1649config RANDOMIZE_BASE 1650 bool "Randomize the address of the kernel image" 1651 depends on RELOCATABLE 1652 depends on !HIBERNATION 1653 default n 1654 ---help--- 1655 Randomizes the physical and virtual address at which the 1656 kernel image is decompressed, as a security feature that 1657 deters exploit attempts relying on knowledge of the location 1658 of kernel internals. 1659 1660 Entropy is generated using the RDRAND instruction if it is 1661 supported. If RDTSC is supported, it is used as well. If 1662 neither RDRAND nor RDTSC are supported, then randomness is 1663 read from the i8254 timer. 1664 1665 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1666 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1667 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1668 minimum of 2MiB, only 10 bits of entropy is theoretically 1669 possible. At best, due to page table layouts, 64-bit can use 1670 9 bits of entropy and 32-bit uses 8 bits. 1671 1672 If unsure, say N. 1673 1674config RANDOMIZE_BASE_MAX_OFFSET 1675 hex "Maximum kASLR offset allowed" if EXPERT 1676 depends on RANDOMIZE_BASE 1677 range 0x0 0x20000000 if X86_32 1678 default "0x20000000" if X86_32 1679 range 0x0 0x40000000 if X86_64 1680 default "0x40000000" if X86_64 1681 ---help--- 1682 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1683 memory is used to determine the maximal offset in bytes that will 1684 be applied to the kernel when kernel Address Space Layout 1685 Randomization (kASLR) is active. This must be a multiple of 1686 PHYSICAL_ALIGN. 1687 1688 On 32-bit this is limited to 512MiB by page table layouts. The 1689 default is 512MiB. 1690 1691 On 64-bit this is limited by how the kernel fixmap page table is 1692 positioned, so this cannot be larger than 1GiB currently. Without 1693 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1694 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1695 modules area will shrink to compensate, up to the current maximum 1696 1GiB to 1GiB split. The default is 1GiB. 1697 1698 If unsure, leave at the default value. 1699 1700# Relocation on x86 needs some additional build support 1701config X86_NEED_RELOCS 1702 def_bool y 1703 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1704 1705config PHYSICAL_ALIGN 1706 hex "Alignment value to which kernel should be aligned" 1707 default "0x200000" 1708 range 0x2000 0x1000000 if X86_32 1709 range 0x200000 0x1000000 if X86_64 1710 ---help--- 1711 This value puts the alignment restrictions on physical address 1712 where kernel is loaded and run from. Kernel is compiled for an 1713 address which meets above alignment restriction. 1714 1715 If bootloader loads the kernel at a non-aligned address and 1716 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1717 address aligned to above value and run from there. 1718 1719 If bootloader loads the kernel at a non-aligned address and 1720 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1721 load address and decompress itself to the address it has been 1722 compiled for and run from there. The address for which kernel is 1723 compiled already meets above alignment restrictions. Hence the 1724 end result is that kernel runs from a physical address meeting 1725 above alignment restrictions. 1726 1727 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1728 this value must be a multiple of 0x200000. 1729 1730 Don't change this unless you know what you are doing. 1731 1732config HOTPLUG_CPU 1733 bool "Support for hot-pluggable CPUs" 1734 depends on SMP 1735 ---help--- 1736 Say Y here to allow turning CPUs off and on. CPUs can be 1737 controlled through /sys/devices/system/cpu. 1738 ( Note: power management support will enable this option 1739 automatically on SMP systems. ) 1740 Say N if you want to disable CPU hotplug. 1741 1742config BOOTPARAM_HOTPLUG_CPU0 1743 bool "Set default setting of cpu0_hotpluggable" 1744 default n 1745 depends on HOTPLUG_CPU 1746 ---help--- 1747 Set whether default state of cpu0_hotpluggable is on or off. 1748 1749 Say Y here to enable CPU0 hotplug by default. If this switch 1750 is turned on, there is no need to give cpu0_hotplug kernel 1751 parameter and the CPU0 hotplug feature is enabled by default. 1752 1753 Please note: there are two known CPU0 dependencies if you want 1754 to enable the CPU0 hotplug feature either by this switch or by 1755 cpu0_hotplug kernel parameter. 1756 1757 First, resume from hibernate or suspend always starts from CPU0. 1758 So hibernate and suspend are prevented if CPU0 is offline. 1759 1760 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1761 offline if any interrupt can not migrate out of CPU0. There may 1762 be other CPU0 dependencies. 1763 1764 Please make sure the dependencies are under your control before 1765 you enable this feature. 1766 1767 Say N if you don't want to enable CPU0 hotplug feature by default. 1768 You still can enable the CPU0 hotplug feature at boot by kernel 1769 parameter cpu0_hotplug. 1770 1771config DEBUG_HOTPLUG_CPU0 1772 def_bool n 1773 prompt "Debug CPU0 hotplug" 1774 depends on HOTPLUG_CPU 1775 ---help--- 1776 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1777 soon as possible and boots up userspace with CPU0 offlined. User 1778 can online CPU0 back after boot time. 1779 1780 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1781 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1782 compilation or giving cpu0_hotplug kernel parameter at boot. 1783 1784 If unsure, say N. 1785 1786config COMPAT_VDSO 1787 def_bool n 1788 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 1789 depends on X86_32 || IA32_EMULATION 1790 ---help--- 1791 Certain buggy versions of glibc will crash if they are 1792 presented with a 32-bit vDSO that is not mapped at the address 1793 indicated in its segment table. 1794 1795 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 1796 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 1797 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 1798 the only released version with the bug, but OpenSUSE 9 1799 contains a buggy "glibc 2.3.2". 1800 1801 The symptom of the bug is that everything crashes on startup, saying: 1802 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 1803 1804 Saying Y here changes the default value of the vdso32 boot 1805 option from 1 to 0, which turns off the 32-bit vDSO entirely. 1806 This works around the glibc bug but hurts performance. 1807 1808 If unsure, say N: if you are compiling your own kernel, you 1809 are unlikely to be using a buggy version of glibc. 1810 1811config CMDLINE_BOOL 1812 bool "Built-in kernel command line" 1813 ---help--- 1814 Allow for specifying boot arguments to the kernel at 1815 build time. On some systems (e.g. embedded ones), it is 1816 necessary or convenient to provide some or all of the 1817 kernel boot arguments with the kernel itself (that is, 1818 to not rely on the boot loader to provide them.) 1819 1820 To compile command line arguments into the kernel, 1821 set this option to 'Y', then fill in the 1822 the boot arguments in CONFIG_CMDLINE. 1823 1824 Systems with fully functional boot loaders (i.e. non-embedded) 1825 should leave this option set to 'N'. 1826 1827config CMDLINE 1828 string "Built-in kernel command string" 1829 depends on CMDLINE_BOOL 1830 default "" 1831 ---help--- 1832 Enter arguments here that should be compiled into the kernel 1833 image and used at boot time. If the boot loader provides a 1834 command line at boot time, it is appended to this string to 1835 form the full kernel command line, when the system boots. 1836 1837 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1838 change this behavior. 1839 1840 In most cases, the command line (whether built-in or provided 1841 by the boot loader) should specify the device for the root 1842 file system. 1843 1844config CMDLINE_OVERRIDE 1845 bool "Built-in command line overrides boot loader arguments" 1846 depends on CMDLINE_BOOL 1847 ---help--- 1848 Set this option to 'Y' to have the kernel ignore the boot loader 1849 command line, and use ONLY the built-in command line. 1850 1851 This is used to work around broken boot loaders. This should 1852 be set to 'N' under normal conditions. 1853 1854endmenu 1855 1856config ARCH_ENABLE_MEMORY_HOTPLUG 1857 def_bool y 1858 depends on X86_64 || (X86_32 && HIGHMEM) 1859 1860config ARCH_ENABLE_MEMORY_HOTREMOVE 1861 def_bool y 1862 depends on MEMORY_HOTPLUG 1863 1864config USE_PERCPU_NUMA_NODE_ID 1865 def_bool y 1866 depends on NUMA 1867 1868config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1869 def_bool y 1870 depends on X86_64 || X86_PAE 1871 1872menu "Power management and ACPI options" 1873 1874config ARCH_HIBERNATION_HEADER 1875 def_bool y 1876 depends on X86_64 && HIBERNATION 1877 1878source "kernel/power/Kconfig" 1879 1880source "drivers/acpi/Kconfig" 1881 1882source "drivers/sfi/Kconfig" 1883 1884config X86_APM_BOOT 1885 def_bool y 1886 depends on APM 1887 1888menuconfig APM 1889 tristate "APM (Advanced Power Management) BIOS support" 1890 depends on X86_32 && PM_SLEEP 1891 ---help--- 1892 APM is a BIOS specification for saving power using several different 1893 techniques. This is mostly useful for battery powered laptops with 1894 APM compliant BIOSes. If you say Y here, the system time will be 1895 reset after a RESUME operation, the /proc/apm device will provide 1896 battery status information, and user-space programs will receive 1897 notification of APM "events" (e.g. battery status change). 1898 1899 If you select "Y" here, you can disable actual use of the APM 1900 BIOS by passing the "apm=off" option to the kernel at boot time. 1901 1902 Note that the APM support is almost completely disabled for 1903 machines with more than one CPU. 1904 1905 In order to use APM, you will need supporting software. For location 1906 and more information, read <file:Documentation/power/apm-acpi.txt> 1907 and the Battery Powered Linux mini-HOWTO, available from 1908 <http://www.tldp.org/docs.html#howto>. 1909 1910 This driver does not spin down disk drives (see the hdparm(8) 1911 manpage ("man 8 hdparm") for that), and it doesn't turn off 1912 VESA-compliant "green" monitors. 1913 1914 This driver does not support the TI 4000M TravelMate and the ACER 1915 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1916 desktop machines also don't have compliant BIOSes, and this driver 1917 may cause those machines to panic during the boot phase. 1918 1919 Generally, if you don't have a battery in your machine, there isn't 1920 much point in using this driver and you should say N. If you get 1921 random kernel OOPSes or reboots that don't seem to be related to 1922 anything, try disabling/enabling this option (or disabling/enabling 1923 APM in your BIOS). 1924 1925 Some other things you should try when experiencing seemingly random, 1926 "weird" problems: 1927 1928 1) make sure that you have enough swap space and that it is 1929 enabled. 1930 2) pass the "no-hlt" option to the kernel 1931 3) switch on floating point emulation in the kernel and pass 1932 the "no387" option to the kernel 1933 4) pass the "floppy=nodma" option to the kernel 1934 5) pass the "mem=4M" option to the kernel (thereby disabling 1935 all but the first 4 MB of RAM) 1936 6) make sure that the CPU is not over clocked. 1937 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1938 8) disable the cache from your BIOS settings 1939 9) install a fan for the video card or exchange video RAM 1940 10) install a better fan for the CPU 1941 11) exchange RAM chips 1942 12) exchange the motherboard. 1943 1944 To compile this driver as a module, choose M here: the 1945 module will be called apm. 1946 1947if APM 1948 1949config APM_IGNORE_USER_SUSPEND 1950 bool "Ignore USER SUSPEND" 1951 ---help--- 1952 This option will ignore USER SUSPEND requests. On machines with a 1953 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1954 series notebooks, it is necessary to say Y because of a BIOS bug. 1955 1956config APM_DO_ENABLE 1957 bool "Enable PM at boot time" 1958 ---help--- 1959 Enable APM features at boot time. From page 36 of the APM BIOS 1960 specification: "When disabled, the APM BIOS does not automatically 1961 power manage devices, enter the Standby State, enter the Suspend 1962 State, or take power saving steps in response to CPU Idle calls." 1963 This driver will make CPU Idle calls when Linux is idle (unless this 1964 feature is turned off -- see "Do CPU IDLE calls", below). This 1965 should always save battery power, but more complicated APM features 1966 will be dependent on your BIOS implementation. You may need to turn 1967 this option off if your computer hangs at boot time when using APM 1968 support, or if it beeps continuously instead of suspending. Turn 1969 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1970 T400CDT. This is off by default since most machines do fine without 1971 this feature. 1972 1973config APM_CPU_IDLE 1974 depends on CPU_IDLE 1975 bool "Make CPU Idle calls when idle" 1976 ---help--- 1977 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1978 On some machines, this can activate improved power savings, such as 1979 a slowed CPU clock rate, when the machine is idle. These idle calls 1980 are made after the idle loop has run for some length of time (e.g., 1981 333 mS). On some machines, this will cause a hang at boot time or 1982 whenever the CPU becomes idle. (On machines with more than one CPU, 1983 this option does nothing.) 1984 1985config APM_DISPLAY_BLANK 1986 bool "Enable console blanking using APM" 1987 ---help--- 1988 Enable console blanking using the APM. Some laptops can use this to 1989 turn off the LCD backlight when the screen blanker of the Linux 1990 virtual console blanks the screen. Note that this is only used by 1991 the virtual console screen blanker, and won't turn off the backlight 1992 when using the X Window system. This also doesn't have anything to 1993 do with your VESA-compliant power-saving monitor. Further, this 1994 option doesn't work for all laptops -- it might not turn off your 1995 backlight at all, or it might print a lot of errors to the console, 1996 especially if you are using gpm. 1997 1998config APM_ALLOW_INTS 1999 bool "Allow interrupts during APM BIOS calls" 2000 ---help--- 2001 Normally we disable external interrupts while we are making calls to 2002 the APM BIOS as a measure to lessen the effects of a badly behaving 2003 BIOS implementation. The BIOS should reenable interrupts if it 2004 needs to. Unfortunately, some BIOSes do not -- especially those in 2005 many of the newer IBM Thinkpads. If you experience hangs when you 2006 suspend, try setting this to Y. Otherwise, say N. 2007 2008endif # APM 2009 2010source "drivers/cpufreq/Kconfig" 2011 2012source "drivers/cpuidle/Kconfig" 2013 2014source "drivers/idle/Kconfig" 2015 2016endmenu 2017 2018 2019menu "Bus options (PCI etc.)" 2020 2021config PCI 2022 bool "PCI support" 2023 default y 2024 ---help--- 2025 Find out whether you have a PCI motherboard. PCI is the name of a 2026 bus system, i.e. the way the CPU talks to the other stuff inside 2027 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2028 VESA. If you have PCI, say Y, otherwise N. 2029 2030choice 2031 prompt "PCI access mode" 2032 depends on X86_32 && PCI 2033 default PCI_GOANY 2034 ---help--- 2035 On PCI systems, the BIOS can be used to detect the PCI devices and 2036 determine their configuration. However, some old PCI motherboards 2037 have BIOS bugs and may crash if this is done. Also, some embedded 2038 PCI-based systems don't have any BIOS at all. Linux can also try to 2039 detect the PCI hardware directly without using the BIOS. 2040 2041 With this option, you can specify how Linux should detect the 2042 PCI devices. If you choose "BIOS", the BIOS will be used, 2043 if you choose "Direct", the BIOS won't be used, and if you 2044 choose "MMConfig", then PCI Express MMCONFIG will be used. 2045 If you choose "Any", the kernel will try MMCONFIG, then the 2046 direct access method and falls back to the BIOS if that doesn't 2047 work. If unsure, go with the default, which is "Any". 2048 2049config PCI_GOBIOS 2050 bool "BIOS" 2051 2052config PCI_GOMMCONFIG 2053 bool "MMConfig" 2054 2055config PCI_GODIRECT 2056 bool "Direct" 2057 2058config PCI_GOOLPC 2059 bool "OLPC XO-1" 2060 depends on OLPC 2061 2062config PCI_GOANY 2063 bool "Any" 2064 2065endchoice 2066 2067config PCI_BIOS 2068 def_bool y 2069 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2070 2071# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2072config PCI_DIRECT 2073 def_bool y 2074 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2075 2076config PCI_MMCONFIG 2077 def_bool y 2078 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2079 2080config PCI_OLPC 2081 def_bool y 2082 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2083 2084config PCI_XEN 2085 def_bool y 2086 depends on PCI && XEN 2087 select SWIOTLB_XEN 2088 2089config PCI_DOMAINS 2090 def_bool y 2091 depends on PCI 2092 2093config PCI_MMCONFIG 2094 bool "Support mmconfig PCI config space access" 2095 depends on X86_64 && PCI && ACPI 2096 2097config PCI_CNB20LE_QUIRK 2098 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2099 depends on PCI 2100 help 2101 Read the PCI windows out of the CNB20LE host bridge. This allows 2102 PCI hotplug to work on systems with the CNB20LE chipset which do 2103 not have ACPI. 2104 2105 There's no public spec for this chipset, and this functionality 2106 is known to be incomplete. 2107 2108 You should say N unless you know you need this. 2109 2110source "drivers/pci/pcie/Kconfig" 2111 2112source "drivers/pci/Kconfig" 2113 2114# x86_64 have no ISA slots, but can have ISA-style DMA. 2115config ISA_DMA_API 2116 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2117 default y 2118 help 2119 Enables ISA-style DMA support for devices requiring such controllers. 2120 If unsure, say Y. 2121 2122if X86_32 2123 2124config ISA 2125 bool "ISA support" 2126 ---help--- 2127 Find out whether you have ISA slots on your motherboard. ISA is the 2128 name of a bus system, i.e. the way the CPU talks to the other stuff 2129 inside your box. Other bus systems are PCI, EISA, MicroChannel 2130 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2131 newer boards don't support it. If you have ISA, say Y, otherwise N. 2132 2133config EISA 2134 bool "EISA support" 2135 depends on ISA 2136 ---help--- 2137 The Extended Industry Standard Architecture (EISA) bus was 2138 developed as an open alternative to the IBM MicroChannel bus. 2139 2140 The EISA bus provided some of the features of the IBM MicroChannel 2141 bus while maintaining backward compatibility with cards made for 2142 the older ISA bus. The EISA bus saw limited use between 1988 and 2143 1995 when it was made obsolete by the PCI bus. 2144 2145 Say Y here if you are building a kernel for an EISA-based machine. 2146 2147 Otherwise, say N. 2148 2149source "drivers/eisa/Kconfig" 2150 2151config SCx200 2152 tristate "NatSemi SCx200 support" 2153 ---help--- 2154 This provides basic support for National Semiconductor's 2155 (now AMD's) Geode processors. The driver probes for the 2156 PCI-IDs of several on-chip devices, so its a good dependency 2157 for other scx200_* drivers. 2158 2159 If compiled as a module, the driver is named scx200. 2160 2161config SCx200HR_TIMER 2162 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2163 depends on SCx200 2164 default y 2165 ---help--- 2166 This driver provides a clocksource built upon the on-chip 2167 27MHz high-resolution timer. Its also a workaround for 2168 NSC Geode SC-1100's buggy TSC, which loses time when the 2169 processor goes idle (as is done by the scheduler). The 2170 other workaround is idle=poll boot option. 2171 2172config OLPC 2173 bool "One Laptop Per Child support" 2174 depends on !X86_PAE 2175 select GPIOLIB 2176 select OF 2177 select OF_PROMTREE 2178 select IRQ_DOMAIN 2179 ---help--- 2180 Add support for detecting the unique features of the OLPC 2181 XO hardware. 2182 2183config OLPC_XO1_PM 2184 bool "OLPC XO-1 Power Management" 2185 depends on OLPC && MFD_CS5535 && PM_SLEEP 2186 select MFD_CORE 2187 ---help--- 2188 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2189 2190config OLPC_XO1_RTC 2191 bool "OLPC XO-1 Real Time Clock" 2192 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2193 ---help--- 2194 Add support for the XO-1 real time clock, which can be used as a 2195 programmable wakeup source. 2196 2197config OLPC_XO1_SCI 2198 bool "OLPC XO-1 SCI extras" 2199 depends on OLPC && OLPC_XO1_PM 2200 depends on INPUT=y 2201 select POWER_SUPPLY 2202 select GPIO_CS5535 2203 select MFD_CORE 2204 ---help--- 2205 Add support for SCI-based features of the OLPC XO-1 laptop: 2206 - EC-driven system wakeups 2207 - Power button 2208 - Ebook switch 2209 - Lid switch 2210 - AC adapter status updates 2211 - Battery status updates 2212 2213config OLPC_XO15_SCI 2214 bool "OLPC XO-1.5 SCI extras" 2215 depends on OLPC && ACPI 2216 select POWER_SUPPLY 2217 ---help--- 2218 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2219 - EC-driven system wakeups 2220 - AC adapter status updates 2221 - Battery status updates 2222 2223config ALIX 2224 bool "PCEngines ALIX System Support (LED setup)" 2225 select GPIOLIB 2226 ---help--- 2227 This option enables system support for the PCEngines ALIX. 2228 At present this just sets up LEDs for GPIO control on 2229 ALIX2/3/6 boards. However, other system specific setup should 2230 get added here. 2231 2232 Note: You must still enable the drivers for GPIO and LED support 2233 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2234 2235 Note: You have to set alix.force=1 for boards with Award BIOS. 2236 2237config NET5501 2238 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2239 select GPIOLIB 2240 ---help--- 2241 This option enables system support for the Soekris Engineering net5501. 2242 2243config GEOS 2244 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2245 select GPIOLIB 2246 depends on DMI 2247 ---help--- 2248 This option enables system support for the Traverse Technologies GEOS. 2249 2250config TS5500 2251 bool "Technologic Systems TS-5500 platform support" 2252 depends on MELAN 2253 select CHECK_SIGNATURE 2254 select NEW_LEDS 2255 select LEDS_CLASS 2256 ---help--- 2257 This option enables system support for the Technologic Systems TS-5500. 2258 2259endif # X86_32 2260 2261config AMD_NB 2262 def_bool y 2263 depends on CPU_SUP_AMD && PCI 2264 2265source "drivers/pcmcia/Kconfig" 2266 2267source "drivers/pci/hotplug/Kconfig" 2268 2269config RAPIDIO 2270 tristate "RapidIO support" 2271 depends on PCI 2272 default n 2273 help 2274 If enabled this option will include drivers and the core 2275 infrastructure code to support RapidIO interconnect devices. 2276 2277source "drivers/rapidio/Kconfig" 2278 2279config X86_SYSFB 2280 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2281 help 2282 Firmwares often provide initial graphics framebuffers so the BIOS, 2283 bootloader or kernel can show basic video-output during boot for 2284 user-guidance and debugging. Historically, x86 used the VESA BIOS 2285 Extensions and EFI-framebuffers for this, which are mostly limited 2286 to x86. 2287 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2288 framebuffers so the new generic system-framebuffer drivers can be 2289 used on x86. If the framebuffer is not compatible with the generic 2290 modes, it is adverticed as fallback platform framebuffer so legacy 2291 drivers like efifb, vesafb and uvesafb can pick it up. 2292 If this option is not selected, all system framebuffers are always 2293 marked as fallback platform framebuffers as usual. 2294 2295 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2296 not be able to pick up generic system framebuffers if this option 2297 is selected. You are highly encouraged to enable simplefb as 2298 replacement if you select this option. simplefb can correctly deal 2299 with generic system framebuffers. But you should still keep vesafb 2300 and others enabled as fallback if a system framebuffer is 2301 incompatible with simplefb. 2302 2303 If unsure, say Y. 2304 2305endmenu 2306 2307 2308menu "Executable file formats / Emulations" 2309 2310source "fs/Kconfig.binfmt" 2311 2312config IA32_EMULATION 2313 bool "IA32 Emulation" 2314 depends on X86_64 2315 select BINFMT_ELF 2316 select COMPAT_BINFMT_ELF 2317 select HAVE_UID16 2318 ---help--- 2319 Include code to run legacy 32-bit programs under a 2320 64-bit kernel. You should likely turn this on, unless you're 2321 100% sure that you don't have any 32-bit programs left. 2322 2323config IA32_AOUT 2324 tristate "IA32 a.out support" 2325 depends on IA32_EMULATION 2326 ---help--- 2327 Support old a.out binaries in the 32bit emulation. 2328 2329config X86_X32 2330 bool "x32 ABI for 64-bit mode" 2331 depends on X86_64 && IA32_EMULATION 2332 ---help--- 2333 Include code to run binaries for the x32 native 32-bit ABI 2334 for 64-bit processors. An x32 process gets access to the 2335 full 64-bit register file and wide data path while leaving 2336 pointers at 32 bits for smaller memory footprint. 2337 2338 You will need a recent binutils (2.22 or later) with 2339 elf32_x86_64 support enabled to compile a kernel with this 2340 option set. 2341 2342config COMPAT 2343 def_bool y 2344 depends on IA32_EMULATION || X86_X32 2345 select ARCH_WANT_OLD_COMPAT_IPC 2346 2347if COMPAT 2348config COMPAT_FOR_U64_ALIGNMENT 2349 def_bool y 2350 2351config SYSVIPC_COMPAT 2352 def_bool y 2353 depends on SYSVIPC 2354 2355config KEYS_COMPAT 2356 def_bool y 2357 depends on KEYS 2358endif 2359 2360endmenu 2361 2362 2363config HAVE_ATOMIC_IOMAP 2364 def_bool y 2365 depends on X86_32 2366 2367config X86_DEV_DMA_OPS 2368 bool 2369 depends on X86_64 || STA2X11 2370 2371config X86_DMA_REMAP 2372 bool 2373 depends on STA2X11 2374 2375config IOSF_MBI 2376 bool 2377 depends on PCI 2378 ---help--- 2379 To be selected by modules requiring access to the Intel OnChip System 2380 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms 2381 enumerable by PCI. 2382 2383source "net/Kconfig" 2384 2385source "drivers/Kconfig" 2386 2387source "drivers/firmware/Kconfig" 2388 2389source "fs/Kconfig" 2390 2391source "arch/x86/Kconfig.debug" 2392 2393source "security/Kconfig" 2394 2395source "crypto/Kconfig" 2396 2397source "arch/x86/kvm/Kconfig" 2398 2399source "lib/Kconfig" 2400