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 GENERIC_EARLY_IOREMAP 47 select HAVE_OPTPROBES 48 select HAVE_KPROBES_ON_FTRACE 49 select HAVE_FTRACE_MCOUNT_RECORD 50 select HAVE_FENTRY if X86_64 51 select HAVE_C_RECORDMCOUNT 52 select HAVE_DYNAMIC_FTRACE 53 select HAVE_DYNAMIC_FTRACE_WITH_REGS 54 select HAVE_FUNCTION_TRACER 55 select HAVE_FUNCTION_GRAPH_TRACER 56 select HAVE_FUNCTION_GRAPH_FP_TEST 57 select HAVE_FUNCTION_TRACE_MCOUNT_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 CLKEVT_I8253 100 select ARCH_HAVE_NMI_SAFE_CMPXCHG 101 select GENERIC_IOMAP 102 select DCACHE_WORD_ACCESS 103 select GENERIC_SMP_IDLE_THREAD 104 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 105 select HAVE_ARCH_SECCOMP_FILTER 106 select BUILDTIME_EXTABLE_SORT 107 select GENERIC_CMOS_UPDATE 108 select HAVE_ARCH_SOFT_DIRTY 109 select CLOCKSOURCE_WATCHDOG 110 select GENERIC_CLOCKEVENTS 111 select ARCH_CLOCKSOURCE_DATA 112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 113 select GENERIC_TIME_VSYSCALL 114 select KTIME_SCALAR if X86_32 115 select GENERIC_STRNCPY_FROM_USER 116 select GENERIC_STRNLEN_USER 117 select HAVE_CONTEXT_TRACKING if X86_64 118 select HAVE_IRQ_TIME_ACCOUNTING 119 select VIRT_TO_BUS 120 select MODULES_USE_ELF_REL if X86_32 121 select MODULES_USE_ELF_RELA if X86_64 122 select CLONE_BACKWARDS if X86_32 123 select ARCH_USE_BUILTIN_BSWAP 124 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 125 select OLD_SIGACTION if X86_32 126 select COMPAT_OLD_SIGACTION if IA32_EMULATION 127 select RTC_LIB 128 select HAVE_DEBUG_STACKOVERFLOW 129 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 130 select HAVE_CC_STACKPROTECTOR 131 select GENERIC_CPU_AUTOPROBE 132 select HAVE_ARCH_AUDITSYSCALL 133 134config INSTRUCTION_DECODER 135 def_bool y 136 depends on KPROBES || PERF_EVENTS || UPROBES 137 138config OUTPUT_FORMAT 139 string 140 default "elf32-i386" if X86_32 141 default "elf64-x86-64" if X86_64 142 143config ARCH_DEFCONFIG 144 string 145 default "arch/x86/configs/i386_defconfig" if X86_32 146 default "arch/x86/configs/x86_64_defconfig" if X86_64 147 148config LOCKDEP_SUPPORT 149 def_bool y 150 151config STACKTRACE_SUPPORT 152 def_bool y 153 154config HAVE_LATENCYTOP_SUPPORT 155 def_bool y 156 157config MMU 158 def_bool y 159 160config SBUS 161 bool 162 163config NEED_DMA_MAP_STATE 164 def_bool y 165 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 166 167config NEED_SG_DMA_LENGTH 168 def_bool y 169 170config GENERIC_ISA_DMA 171 def_bool y 172 depends on ISA_DMA_API 173 174config GENERIC_BUG 175 def_bool y 176 depends on BUG 177 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 178 179config GENERIC_BUG_RELATIVE_POINTERS 180 bool 181 182config GENERIC_HWEIGHT 183 def_bool y 184 185config ARCH_MAY_HAVE_PC_FDC 186 def_bool y 187 depends on ISA_DMA_API 188 189config RWSEM_XCHGADD_ALGORITHM 190 def_bool y 191 192config GENERIC_CALIBRATE_DELAY 193 def_bool y 194 195config ARCH_HAS_CPU_RELAX 196 def_bool y 197 198config ARCH_HAS_CACHE_LINE_SIZE 199 def_bool y 200 201config HAVE_SETUP_PER_CPU_AREA 202 def_bool y 203 204config NEED_PER_CPU_EMBED_FIRST_CHUNK 205 def_bool y 206 207config NEED_PER_CPU_PAGE_FIRST_CHUNK 208 def_bool y 209 210config ARCH_HIBERNATION_POSSIBLE 211 def_bool y 212 213config ARCH_SUSPEND_POSSIBLE 214 def_bool y 215 216config ARCH_WANT_HUGE_PMD_SHARE 217 def_bool y 218 219config ARCH_WANT_GENERAL_HUGETLB 220 def_bool y 221 222config ZONE_DMA32 223 bool 224 default X86_64 225 226config AUDIT_ARCH 227 bool 228 default X86_64 229 230config ARCH_SUPPORTS_OPTIMIZED_INLINING 231 def_bool y 232 233config ARCH_SUPPORTS_DEBUG_PAGEALLOC 234 def_bool y 235 236config HAVE_INTEL_TXT 237 def_bool y 238 depends on INTEL_IOMMU && ACPI 239 240config X86_32_SMP 241 def_bool y 242 depends on X86_32 && SMP 243 244config X86_64_SMP 245 def_bool y 246 depends on X86_64 && SMP 247 248config X86_HT 249 def_bool y 250 depends on SMP 251 252config X86_32_LAZY_GS 253 def_bool y 254 depends on X86_32 && !CC_STACKPROTECTOR 255 256config ARCH_HWEIGHT_CFLAGS 257 string 258 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 259 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 260 261config ARCH_SUPPORTS_UPROBES 262 def_bool y 263 264source "init/Kconfig" 265source "kernel/Kconfig.freezer" 266 267menu "Processor type and features" 268 269config ZONE_DMA 270 bool "DMA memory allocation support" if EXPERT 271 default y 272 help 273 DMA memory allocation support allows devices with less than 32-bit 274 addressing to allocate within the first 16MB of address space. 275 Disable if no such devices will be used. 276 277 If unsure, say Y. 278 279config SMP 280 bool "Symmetric multi-processing support" 281 ---help--- 282 This enables support for systems with more than one CPU. If you have 283 a system with only one CPU, say N. If you have a system with more 284 than one CPU, say Y. 285 286 If you say N here, the kernel will run on uni- and multiprocessor 287 machines, but will use only one CPU of a multiprocessor machine. If 288 you say Y here, the kernel will run on many, but not all, 289 uniprocessor machines. On a uniprocessor machine, the kernel 290 will run faster if you say N here. 291 292 Note that if you say Y here and choose architecture "586" or 293 "Pentium" under "Processor family", the kernel will not work on 486 294 architectures. Similarly, multiprocessor kernels for the "PPro" 295 architecture may not work on all Pentium based boards. 296 297 People using multiprocessor machines who say Y here should also say 298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 299 Management" code will be disabled if you say Y here. 300 301 See also <file:Documentation/x86/i386/IO-APIC.txt>, 302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 303 <http://www.tldp.org/docs.html#howto>. 304 305 If you don't know what to do here, say N. 306 307config X86_X2APIC 308 bool "Support x2apic" 309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 310 ---help--- 311 This enables x2apic support on CPUs that have this feature. 312 313 This allows 32-bit apic IDs (so it can support very large systems), 314 and accesses the local apic via MSRs not via mmio. 315 316 If you don't know what to do here, say N. 317 318config X86_MPPARSE 319 bool "Enable MPS table" if ACPI || SFI 320 default y 321 depends on X86_LOCAL_APIC 322 ---help--- 323 For old smp systems that do not have proper acpi support. Newer systems 324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 325 326config X86_BIGSMP 327 bool "Support for big SMP systems with more than 8 CPUs" 328 depends on X86_32 && SMP 329 ---help--- 330 This option is needed for the systems that have more than 8 CPUs 331 332config GOLDFISH 333 def_bool y 334 depends on X86_GOLDFISH 335 336if X86_32 337config X86_EXTENDED_PLATFORM 338 bool "Support for extended (non-PC) x86 platforms" 339 default y 340 ---help--- 341 If you disable this option then the kernel will only support 342 standard PC platforms. (which covers the vast majority of 343 systems out there.) 344 345 If you enable this option then you'll be able to select support 346 for the following (non-PC) 32 bit x86 platforms: 347 Goldfish (Android emulator) 348 AMD Elan 349 RDC R-321x SoC 350 SGI 320/540 (Visual Workstation) 351 STA2X11-based (e.g. Northville) 352 Moorestown MID devices 353 354 If you have one of these systems, or if you want to build a 355 generic distribution kernel, say Y here - otherwise say N. 356endif 357 358if X86_64 359config X86_EXTENDED_PLATFORM 360 bool "Support for extended (non-PC) x86 platforms" 361 default y 362 ---help--- 363 If you disable this option then the kernel will only support 364 standard PC platforms. (which covers the vast majority of 365 systems out there.) 366 367 If you enable this option then you'll be able to select support 368 for the following (non-PC) 64 bit x86 platforms: 369 Numascale NumaChip 370 ScaleMP vSMP 371 SGI Ultraviolet 372 373 If you have one of these systems, or if you want to build a 374 generic distribution kernel, say Y here - otherwise say N. 375endif 376# This is an alphabetically sorted list of 64 bit extended platforms 377# Please maintain the alphabetic order if and when there are additions 378config X86_NUMACHIP 379 bool "Numascale NumaChip" 380 depends on X86_64 381 depends on X86_EXTENDED_PLATFORM 382 depends on NUMA 383 depends on SMP 384 depends on X86_X2APIC 385 depends on PCI_MMCONFIG 386 ---help--- 387 Adds support for Numascale NumaChip large-SMP systems. Needed to 388 enable more than ~168 cores. 389 If you don't have one of these, you should say N here. 390 391config X86_VSMP 392 bool "ScaleMP vSMP" 393 select HYPERVISOR_GUEST 394 select PARAVIRT 395 depends on X86_64 && PCI 396 depends on X86_EXTENDED_PLATFORM 397 depends on SMP 398 ---help--- 399 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 400 supposed to run on these EM64T-based machines. Only choose this option 401 if you have one of these machines. 402 403config X86_UV 404 bool "SGI Ultraviolet" 405 depends on X86_64 406 depends on X86_EXTENDED_PLATFORM 407 depends on NUMA 408 depends on X86_X2APIC 409 ---help--- 410 This option is needed in order to support SGI Ultraviolet systems. 411 If you don't have one of these, you should say N here. 412 413# Following is an alphabetically sorted list of 32 bit extended platforms 414# Please maintain the alphabetic order if and when there are additions 415 416config X86_GOLDFISH 417 bool "Goldfish (Virtual Platform)" 418 depends on X86_32 419 depends on X86_EXTENDED_PLATFORM 420 ---help--- 421 Enable support for the Goldfish virtual platform used primarily 422 for Android development. Unless you are building for the Android 423 Goldfish emulator say N here. 424 425config X86_INTEL_CE 426 bool "CE4100 TV platform" 427 depends on PCI 428 depends on PCI_GODIRECT 429 depends on X86_32 430 depends on X86_EXTENDED_PLATFORM 431 select X86_REBOOTFIXUPS 432 select OF 433 select OF_EARLY_FLATTREE 434 select IRQ_DOMAIN 435 ---help--- 436 Select for the Intel CE media processor (CE4100) SOC. 437 This option compiles in support for the CE4100 SOC for settop 438 boxes and media devices. 439 440config X86_INTEL_MID 441 bool "Intel MID platform support" 442 depends on X86_32 443 depends on X86_EXTENDED_PLATFORM 444 depends on X86_PLATFORM_DEVICES 445 depends on PCI 446 depends on PCI_GOANY 447 depends on X86_IO_APIC 448 select SFI 449 select I2C 450 select DW_APB_TIMER 451 select APB_TIMER 452 select INTEL_SCU_IPC 453 select MFD_INTEL_MSIC 454 ---help--- 455 Select to build a kernel capable of supporting Intel MID (Mobile 456 Internet Device) platform systems which do not have the PCI legacy 457 interfaces. If you are building for a PC class system say N here. 458 459 Intel MID platforms are based on an Intel processor and chipset which 460 consume less power than most of the x86 derivatives. 461 462config X86_INTEL_LPSS 463 bool "Intel Low Power Subsystem Support" 464 depends on ACPI 465 select COMMON_CLK 466 select PINCTRL 467 ---help--- 468 Select to build support for Intel Low Power Subsystem such as 469 found on Intel Lynxpoint PCH. Selecting this option enables 470 things like clock tree (common clock framework) and pincontrol 471 which are needed by the LPSS peripheral drivers. 472 473config X86_RDC321X 474 bool "RDC R-321x SoC" 475 depends on X86_32 476 depends on X86_EXTENDED_PLATFORM 477 select M486 478 select X86_REBOOTFIXUPS 479 ---help--- 480 This option is needed for RDC R-321x system-on-chip, also known 481 as R-8610-(G). 482 If you don't have one of these chips, you should say N here. 483 484config X86_32_NON_STANDARD 485 bool "Support non-standard 32-bit SMP architectures" 486 depends on X86_32 && SMP 487 depends on X86_EXTENDED_PLATFORM 488 ---help--- 489 This option compiles in the bigsmp and STA2X11 default 490 subarchitectures. It is intended for a generic binary 491 kernel. If you select them all, kernel will probe it one by 492 one and will fallback to default. 493 494# Alphabetically sorted list of Non standard 32 bit platforms 495 496config X86_SUPPORTS_MEMORY_FAILURE 497 def_bool y 498 # MCE code calls memory_failure(): 499 depends on X86_MCE 500 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 501 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 502 depends on X86_64 || !SPARSEMEM 503 select ARCH_SUPPORTS_MEMORY_FAILURE 504 505config STA2X11 506 bool "STA2X11 Companion Chip Support" 507 depends on X86_32_NON_STANDARD && PCI 508 select X86_DEV_DMA_OPS 509 select X86_DMA_REMAP 510 select SWIOTLB 511 select MFD_STA2X11 512 select ARCH_REQUIRE_GPIOLIB 513 default n 514 ---help--- 515 This adds support for boards based on the STA2X11 IO-Hub, 516 a.k.a. "ConneXt". The chip is used in place of the standard 517 PC chipset, so all "standard" peripherals are missing. If this 518 option is selected the kernel will still be able to boot on 519 standard PC machines. 520 521config X86_32_IRIS 522 tristate "Eurobraille/Iris poweroff module" 523 depends on X86_32 524 ---help--- 525 The Iris machines from EuroBraille do not have APM or ACPI support 526 to shut themselves down properly. A special I/O sequence is 527 needed to do so, which is what this module does at 528 kernel shutdown. 529 530 This is only for Iris machines from EuroBraille. 531 532 If unused, say N. 533 534config SCHED_OMIT_FRAME_POINTER 535 def_bool y 536 prompt "Single-depth WCHAN output" 537 depends on X86 538 ---help--- 539 Calculate simpler /proc/<PID>/wchan values. If this option 540 is disabled then wchan values will recurse back to the 541 caller function. This provides more accurate wchan values, 542 at the expense of slightly more scheduling overhead. 543 544 If in doubt, say "Y". 545 546menuconfig HYPERVISOR_GUEST 547 bool "Linux guest support" 548 ---help--- 549 Say Y here to enable options for running Linux under various hyper- 550 visors. This option enables basic hypervisor detection and platform 551 setup. 552 553 If you say N, all options in this submenu will be skipped and 554 disabled, and Linux guest support won't be built in. 555 556if HYPERVISOR_GUEST 557 558config PARAVIRT 559 bool "Enable paravirtualization code" 560 ---help--- 561 This changes the kernel so it can modify itself when it is run 562 under a hypervisor, potentially improving performance significantly 563 over full virtualization. However, when run without a hypervisor 564 the kernel is theoretically slower and slightly larger. 565 566config PARAVIRT_DEBUG 567 bool "paravirt-ops debugging" 568 depends on PARAVIRT && DEBUG_KERNEL 569 ---help--- 570 Enable to debug paravirt_ops internals. Specifically, BUG if 571 a paravirt_op is missing when it is called. 572 573config PARAVIRT_SPINLOCKS 574 bool "Paravirtualization layer for spinlocks" 575 depends on PARAVIRT && SMP 576 select UNINLINE_SPIN_UNLOCK 577 ---help--- 578 Paravirtualized spinlocks allow a pvops backend to replace the 579 spinlock implementation with something virtualization-friendly 580 (for example, block the virtual CPU rather than spinning). 581 582 It has a minimal impact on native kernels and gives a nice performance 583 benefit on paravirtualized KVM / Xen kernels. 584 585 If you are unsure how to answer this question, answer Y. 586 587source "arch/x86/xen/Kconfig" 588 589config KVM_GUEST 590 bool "KVM Guest support (including kvmclock)" 591 depends on PARAVIRT 592 select PARAVIRT_CLOCK 593 default y 594 ---help--- 595 This option enables various optimizations for running under the KVM 596 hypervisor. It includes a paravirtualized clock, so that instead 597 of relying on a PIT (or probably other) emulation by the 598 underlying device model, the host provides the guest with 599 timing infrastructure such as time of day, and system time 600 601config KVM_DEBUG_FS 602 bool "Enable debug information for KVM Guests in debugfs" 603 depends on KVM_GUEST && DEBUG_FS 604 default n 605 ---help--- 606 This option enables collection of various statistics for KVM guest. 607 Statistics are displayed in debugfs filesystem. Enabling this option 608 may incur significant overhead. 609 610source "arch/x86/lguest/Kconfig" 611 612config PARAVIRT_TIME_ACCOUNTING 613 bool "Paravirtual steal time accounting" 614 depends on PARAVIRT 615 default n 616 ---help--- 617 Select this option to enable fine granularity task steal time 618 accounting. Time spent executing other tasks in parallel with 619 the current vCPU is discounted from the vCPU power. To account for 620 that, there can be a small performance impact. 621 622 If in doubt, say N here. 623 624config PARAVIRT_CLOCK 625 bool 626 627endif #HYPERVISOR_GUEST 628 629config NO_BOOTMEM 630 def_bool y 631 632config MEMTEST 633 bool "Memtest" 634 ---help--- 635 This option adds a kernel parameter 'memtest', which allows memtest 636 to be set. 637 memtest=0, mean disabled; -- default 638 memtest=1, mean do 1 test pattern; 639 ... 640 memtest=4, mean do 4 test patterns. 641 If you are unsure how to answer this question, answer N. 642 643source "arch/x86/Kconfig.cpu" 644 645config HPET_TIMER 646 def_bool X86_64 647 prompt "HPET Timer Support" if X86_32 648 ---help--- 649 Use the IA-PC HPET (High Precision Event Timer) to manage 650 time in preference to the PIT and RTC, if a HPET is 651 present. 652 HPET is the next generation timer replacing legacy 8254s. 653 The HPET provides a stable time base on SMP 654 systems, unlike the TSC, but it is more expensive to access, 655 as it is off-chip. You can find the HPET spec at 656 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 657 658 You can safely choose Y here. However, HPET will only be 659 activated if the platform and the BIOS support this feature. 660 Otherwise the 8254 will be used for timing services. 661 662 Choose N to continue using the legacy 8254 timer. 663 664config HPET_EMULATE_RTC 665 def_bool y 666 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 667 668config APB_TIMER 669 def_bool y if X86_INTEL_MID 670 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 671 select DW_APB_TIMER 672 depends on X86_INTEL_MID && SFI 673 help 674 APB timer is the replacement for 8254, HPET on X86 MID platforms. 675 The APBT provides a stable time base on SMP 676 systems, unlike the TSC, but it is more expensive to access, 677 as it is off-chip. APB timers are always running regardless of CPU 678 C states, they are used as per CPU clockevent device when possible. 679 680# Mark as expert because too many people got it wrong. 681# The code disables itself when not needed. 682config DMI 683 default y 684 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 685 bool "Enable DMI scanning" if EXPERT 686 ---help--- 687 Enabled scanning of DMI to identify machine quirks. Say Y 688 here unless you have verified that your setup is not 689 affected by entries in the DMI blacklist. Required by PNP 690 BIOS code. 691 692config GART_IOMMU 693 bool "Old AMD GART IOMMU support" 694 select SWIOTLB 695 depends on X86_64 && PCI && AMD_NB 696 ---help--- 697 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 698 GART based hardware IOMMUs. 699 700 The GART supports full DMA access for devices with 32-bit access 701 limitations, on systems with more than 3 GB. This is usually needed 702 for USB, sound, many IDE/SATA chipsets and some other devices. 703 704 Newer systems typically have a modern AMD IOMMU, supported via 705 the CONFIG_AMD_IOMMU=y config option. 706 707 In normal configurations this driver is only active when needed: 708 there's more than 3 GB of memory and the system contains a 709 32-bit limited device. 710 711 If unsure, say Y. 712 713config CALGARY_IOMMU 714 bool "IBM Calgary IOMMU support" 715 select SWIOTLB 716 depends on X86_64 && PCI 717 ---help--- 718 Support for hardware IOMMUs in IBM's xSeries x366 and x460 719 systems. Needed to run systems with more than 3GB of memory 720 properly with 32-bit PCI devices that do not support DAC 721 (Double Address Cycle). Calgary also supports bus level 722 isolation, where all DMAs pass through the IOMMU. This 723 prevents them from going anywhere except their intended 724 destination. This catches hard-to-find kernel bugs and 725 mis-behaving drivers and devices that do not use the DMA-API 726 properly to set up their DMA buffers. The IOMMU can be 727 turned off at boot time with the iommu=off parameter. 728 Normally the kernel will make the right choice by itself. 729 If unsure, say Y. 730 731config CALGARY_IOMMU_ENABLED_BY_DEFAULT 732 def_bool y 733 prompt "Should Calgary be enabled by default?" 734 depends on CALGARY_IOMMU 735 ---help--- 736 Should Calgary be enabled by default? if you choose 'y', Calgary 737 will be used (if it exists). If you choose 'n', Calgary will not be 738 used even if it exists. If you choose 'n' and would like to use 739 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 740 If unsure, say Y. 741 742# need this always selected by IOMMU for the VIA workaround 743config SWIOTLB 744 def_bool y if X86_64 745 ---help--- 746 Support for software bounce buffers used on x86-64 systems 747 which don't have a hardware IOMMU. Using this PCI devices 748 which can only access 32-bits of memory can be used on systems 749 with more than 3 GB of memory. 750 If unsure, say Y. 751 752config IOMMU_HELPER 753 def_bool y 754 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 755 756config MAXSMP 757 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 758 depends on X86_64 && SMP && DEBUG_KERNEL 759 select CPUMASK_OFFSTACK 760 ---help--- 761 Enable maximum number of CPUS and NUMA Nodes for this architecture. 762 If unsure, say N. 763 764config NR_CPUS 765 int "Maximum number of CPUs" if SMP && !MAXSMP 766 range 2 8 if SMP && X86_32 && !X86_BIGSMP 767 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 768 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 769 default "1" if !SMP 770 default "8192" if MAXSMP 771 default "32" if SMP && X86_BIGSMP 772 default "8" if SMP 773 ---help--- 774 This allows you to specify the maximum number of CPUs which this 775 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 776 supported value is 4096, otherwise the maximum value is 512. The 777 minimum value which makes sense is 2. 778 779 This is purely to save memory - each supported CPU adds 780 approximately eight kilobytes to the kernel image. 781 782config SCHED_SMT 783 bool "SMT (Hyperthreading) scheduler support" 784 depends on X86_HT 785 ---help--- 786 SMT scheduler support improves the CPU scheduler's decision making 787 when dealing with Intel Pentium 4 chips with HyperThreading at a 788 cost of slightly increased overhead in some places. If unsure say 789 N here. 790 791config SCHED_MC 792 def_bool y 793 prompt "Multi-core scheduler support" 794 depends on X86_HT 795 ---help--- 796 Multi-core scheduler support improves the CPU scheduler's decision 797 making when dealing with multi-core CPU chips at a cost of slightly 798 increased overhead in some places. If unsure say N here. 799 800source "kernel/Kconfig.preempt" 801 802config X86_UP_APIC 803 bool "Local APIC support on uniprocessors" 804 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 805 ---help--- 806 A local APIC (Advanced Programmable Interrupt Controller) is an 807 integrated interrupt controller in the CPU. If you have a single-CPU 808 system which has a processor with a local APIC, you can say Y here to 809 enable and use it. If you say Y here even though your machine doesn't 810 have a local APIC, then the kernel will still run with no slowdown at 811 all. The local APIC supports CPU-generated self-interrupts (timer, 812 performance counters), and the NMI watchdog which detects hard 813 lockups. 814 815config X86_UP_IOAPIC 816 bool "IO-APIC support on uniprocessors" 817 depends on X86_UP_APIC 818 ---help--- 819 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 820 SMP-capable replacement for PC-style interrupt controllers. Most 821 SMP systems and many recent uniprocessor systems have one. 822 823 If you have a single-CPU system with an IO-APIC, you can say Y here 824 to use it. If you say Y here even though your machine doesn't have 825 an IO-APIC, then the kernel will still run with no slowdown at all. 826 827config X86_LOCAL_APIC 828 def_bool y 829 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 830 831config X86_IO_APIC 832 def_bool y 833 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 834 835config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 836 bool "Reroute for broken boot IRQs" 837 depends on X86_IO_APIC 838 ---help--- 839 This option enables a workaround that fixes a source of 840 spurious interrupts. This is recommended when threaded 841 interrupt handling is used on systems where the generation of 842 superfluous "boot interrupts" cannot be disabled. 843 844 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 845 entry in the chipset's IO-APIC is masked (as, e.g. the RT 846 kernel does during interrupt handling). On chipsets where this 847 boot IRQ generation cannot be disabled, this workaround keeps 848 the original IRQ line masked so that only the equivalent "boot 849 IRQ" is delivered to the CPUs. The workaround also tells the 850 kernel to set up the IRQ handler on the boot IRQ line. In this 851 way only one interrupt is delivered to the kernel. Otherwise 852 the spurious second interrupt may cause the kernel to bring 853 down (vital) interrupt lines. 854 855 Only affects "broken" chipsets. Interrupt sharing may be 856 increased on these systems. 857 858config X86_MCE 859 bool "Machine Check / overheating reporting" 860 default y 861 ---help--- 862 Machine Check support allows the processor to notify the 863 kernel if it detects a problem (e.g. overheating, data corruption). 864 The action the kernel takes depends on the severity of the problem, 865 ranging from warning messages to halting the machine. 866 867config X86_MCE_INTEL 868 def_bool y 869 prompt "Intel MCE features" 870 depends on X86_MCE && X86_LOCAL_APIC 871 ---help--- 872 Additional support for intel specific MCE features such as 873 the thermal monitor. 874 875config X86_MCE_AMD 876 def_bool y 877 prompt "AMD MCE features" 878 depends on X86_MCE && X86_LOCAL_APIC 879 ---help--- 880 Additional support for AMD specific MCE features such as 881 the DRAM Error Threshold. 882 883config X86_ANCIENT_MCE 884 bool "Support for old Pentium 5 / WinChip machine checks" 885 depends on X86_32 && X86_MCE 886 ---help--- 887 Include support for machine check handling on old Pentium 5 or WinChip 888 systems. These typically need to be enabled explicitly on the command 889 line. 890 891config X86_MCE_THRESHOLD 892 depends on X86_MCE_AMD || X86_MCE_INTEL 893 def_bool y 894 895config X86_MCE_INJECT 896 depends on X86_MCE 897 tristate "Machine check injector support" 898 ---help--- 899 Provide support for injecting machine checks for testing purposes. 900 If you don't know what a machine check is and you don't do kernel 901 QA it is safe to say n. 902 903config X86_THERMAL_VECTOR 904 def_bool y 905 depends on X86_MCE_INTEL 906 907config VM86 908 bool "Enable VM86 support" if EXPERT 909 default y 910 depends on X86_32 911 ---help--- 912 This option is required by programs like DOSEMU to run 16-bit legacy 913 code on X86 processors. It also may be needed by software like 914 XFree86 to initialize some video cards via BIOS. Disabling this 915 option saves about 6k. 916 917config TOSHIBA 918 tristate "Toshiba Laptop support" 919 depends on X86_32 920 ---help--- 921 This adds a driver to safely access the System Management Mode of 922 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 923 not work on models with a Phoenix BIOS. The System Management Mode 924 is used to set the BIOS and power saving options on Toshiba portables. 925 926 For information on utilities to make use of this driver see the 927 Toshiba Linux utilities web site at: 928 <http://www.buzzard.org.uk/toshiba/>. 929 930 Say Y if you intend to run this kernel on a Toshiba portable. 931 Say N otherwise. 932 933config I8K 934 tristate "Dell laptop support" 935 select HWMON 936 ---help--- 937 This adds a driver to safely access the System Management Mode 938 of the CPU on the Dell Inspiron 8000. The System Management Mode 939 is used to read cpu temperature and cooling fan status and to 940 control the fans on the I8K portables. 941 942 This driver has been tested only on the Inspiron 8000 but it may 943 also work with other Dell laptops. You can force loading on other 944 models by passing the parameter `force=1' to the module. Use at 945 your own risk. 946 947 For information on utilities to make use of this driver see the 948 I8K Linux utilities web site at: 949 <http://people.debian.org/~dz/i8k/> 950 951 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 952 Say N otherwise. 953 954config X86_REBOOTFIXUPS 955 bool "Enable X86 board specific fixups for reboot" 956 depends on X86_32 957 ---help--- 958 This enables chipset and/or board specific fixups to be done 959 in order to get reboot to work correctly. This is only needed on 960 some combinations of hardware and BIOS. The symptom, for which 961 this config is intended, is when reboot ends with a stalled/hung 962 system. 963 964 Currently, the only fixup is for the Geode machines using 965 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 966 967 Say Y if you want to enable the fixup. Currently, it's safe to 968 enable this option even if you don't need it. 969 Say N otherwise. 970 971config MICROCODE 972 tristate "CPU microcode loading support" 973 depends on CPU_SUP_AMD || CPU_SUP_INTEL 974 select FW_LOADER 975 ---help--- 976 977 If you say Y here, you will be able to update the microcode on 978 certain Intel and AMD processors. The Intel support is for the 979 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 980 Xeon etc. The AMD support is for families 0x10 and later. You will 981 obviously need the actual microcode binary data itself which is not 982 shipped with the Linux kernel. 983 984 This option selects the general module only, you need to select 985 at least one vendor specific module as well. 986 987 To compile this driver as a module, choose M here: the module 988 will be called microcode. 989 990config MICROCODE_INTEL 991 bool "Intel microcode loading support" 992 depends on MICROCODE 993 default MICROCODE 994 select FW_LOADER 995 ---help--- 996 This options enables microcode patch loading support for Intel 997 processors. 998 999 For the current Intel microcode data package go to 1000 <https://downloadcenter.intel.com> and search for 1001 'Linux Processor Microcode Data File'. 1002 1003config MICROCODE_AMD 1004 bool "AMD microcode loading support" 1005 depends on MICROCODE 1006 select FW_LOADER 1007 ---help--- 1008 If you select this option, microcode patch loading support for AMD 1009 processors will be enabled. 1010 1011config MICROCODE_OLD_INTERFACE 1012 def_bool y 1013 depends on MICROCODE 1014 1015config MICROCODE_INTEL_EARLY 1016 def_bool n 1017 1018config MICROCODE_AMD_EARLY 1019 def_bool n 1020 1021config MICROCODE_EARLY 1022 bool "Early load microcode" 1023 depends on MICROCODE=y && BLK_DEV_INITRD 1024 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1025 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1026 default y 1027 help 1028 This option provides functionality to read additional microcode data 1029 at the beginning of initrd image. The data tells kernel to load 1030 microcode to CPU's as early as possible. No functional change if no 1031 microcode data is glued to the initrd, therefore it's safe to say Y. 1032 1033config X86_MSR 1034 tristate "/dev/cpu/*/msr - Model-specific register support" 1035 ---help--- 1036 This device gives privileged processes access to the x86 1037 Model-Specific Registers (MSRs). It is a character device with 1038 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1039 MSR accesses are directed to a specific CPU on multi-processor 1040 systems. 1041 1042config X86_CPUID 1043 tristate "/dev/cpu/*/cpuid - CPU information support" 1044 ---help--- 1045 This device gives processes access to the x86 CPUID instruction to 1046 be executed on a specific processor. It is a character device 1047 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1048 /dev/cpu/31/cpuid. 1049 1050choice 1051 prompt "High Memory Support" 1052 default HIGHMEM4G 1053 depends on X86_32 1054 1055config NOHIGHMEM 1056 bool "off" 1057 ---help--- 1058 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1059 However, the address space of 32-bit x86 processors is only 4 1060 Gigabytes large. That means that, if you have a large amount of 1061 physical memory, not all of it can be "permanently mapped" by the 1062 kernel. The physical memory that's not permanently mapped is called 1063 "high memory". 1064 1065 If you are compiling a kernel which will never run on a machine with 1066 more than 1 Gigabyte total physical RAM, answer "off" here (default 1067 choice and suitable for most users). This will result in a "3GB/1GB" 1068 split: 3GB are mapped so that each process sees a 3GB virtual memory 1069 space and the remaining part of the 4GB virtual memory space is used 1070 by the kernel to permanently map as much physical memory as 1071 possible. 1072 1073 If the machine has between 1 and 4 Gigabytes physical RAM, then 1074 answer "4GB" here. 1075 1076 If more than 4 Gigabytes is used then answer "64GB" here. This 1077 selection turns Intel PAE (Physical Address Extension) mode on. 1078 PAE implements 3-level paging on IA32 processors. PAE is fully 1079 supported by Linux, PAE mode is implemented on all recent Intel 1080 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1081 then the kernel will not boot on CPUs that don't support PAE! 1082 1083 The actual amount of total physical memory will either be 1084 auto detected or can be forced by using a kernel command line option 1085 such as "mem=256M". (Try "man bootparam" or see the documentation of 1086 your boot loader (lilo or loadlin) about how to pass options to the 1087 kernel at boot time.) 1088 1089 If unsure, say "off". 1090 1091config HIGHMEM4G 1092 bool "4GB" 1093 ---help--- 1094 Select this if you have a 32-bit processor and between 1 and 4 1095 gigabytes of physical RAM. 1096 1097config HIGHMEM64G 1098 bool "64GB" 1099 depends on !M486 1100 select X86_PAE 1101 ---help--- 1102 Select this if you have a 32-bit processor and more than 4 1103 gigabytes of physical RAM. 1104 1105endchoice 1106 1107choice 1108 prompt "Memory split" if EXPERT 1109 default VMSPLIT_3G 1110 depends on X86_32 1111 ---help--- 1112 Select the desired split between kernel and user memory. 1113 1114 If the address range available to the kernel is less than the 1115 physical memory installed, the remaining memory will be available 1116 as "high memory". Accessing high memory is a little more costly 1117 than low memory, as it needs to be mapped into the kernel first. 1118 Note that increasing the kernel address space limits the range 1119 available to user programs, making the address space there 1120 tighter. Selecting anything other than the default 3G/1G split 1121 will also likely make your kernel incompatible with binary-only 1122 kernel modules. 1123 1124 If you are not absolutely sure what you are doing, leave this 1125 option alone! 1126 1127 config VMSPLIT_3G 1128 bool "3G/1G user/kernel split" 1129 config VMSPLIT_3G_OPT 1130 depends on !X86_PAE 1131 bool "3G/1G user/kernel split (for full 1G low memory)" 1132 config VMSPLIT_2G 1133 bool "2G/2G user/kernel split" 1134 config VMSPLIT_2G_OPT 1135 depends on !X86_PAE 1136 bool "2G/2G user/kernel split (for full 2G low memory)" 1137 config VMSPLIT_1G 1138 bool "1G/3G user/kernel split" 1139endchoice 1140 1141config PAGE_OFFSET 1142 hex 1143 default 0xB0000000 if VMSPLIT_3G_OPT 1144 default 0x80000000 if VMSPLIT_2G 1145 default 0x78000000 if VMSPLIT_2G_OPT 1146 default 0x40000000 if VMSPLIT_1G 1147 default 0xC0000000 1148 depends on X86_32 1149 1150config HIGHMEM 1151 def_bool y 1152 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1153 1154config X86_PAE 1155 bool "PAE (Physical Address Extension) Support" 1156 depends on X86_32 && !HIGHMEM4G 1157 ---help--- 1158 PAE is required for NX support, and furthermore enables 1159 larger swapspace support for non-overcommit purposes. It 1160 has the cost of more pagetable lookup overhead, and also 1161 consumes more pagetable space per process. 1162 1163config ARCH_PHYS_ADDR_T_64BIT 1164 def_bool y 1165 depends on X86_64 || X86_PAE 1166 1167config ARCH_DMA_ADDR_T_64BIT 1168 def_bool y 1169 depends on X86_64 || HIGHMEM64G 1170 1171config DIRECT_GBPAGES 1172 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1173 default y 1174 depends on X86_64 1175 ---help--- 1176 Allow the kernel linear mapping to use 1GB pages on CPUs that 1177 support it. This can improve the kernel's performance a tiny bit by 1178 reducing TLB pressure. If in doubt, say "Y". 1179 1180# Common NUMA Features 1181config NUMA 1182 bool "Numa Memory Allocation and Scheduler Support" 1183 depends on SMP 1184 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1185 default y if X86_BIGSMP 1186 ---help--- 1187 Enable NUMA (Non Uniform Memory Access) support. 1188 1189 The kernel will try to allocate memory used by a CPU on the 1190 local memory controller of the CPU and add some more 1191 NUMA awareness to the kernel. 1192 1193 For 64-bit this is recommended if the system is Intel Core i7 1194 (or later), AMD Opteron, or EM64T NUMA. 1195 1196 For 32-bit this is only needed if you boot a 32-bit 1197 kernel on a 64-bit NUMA platform. 1198 1199 Otherwise, you should say N. 1200 1201config AMD_NUMA 1202 def_bool y 1203 prompt "Old style AMD Opteron NUMA detection" 1204 depends on X86_64 && NUMA && PCI 1205 ---help--- 1206 Enable AMD NUMA node topology detection. You should say Y here if 1207 you have a multi processor AMD system. This uses an old method to 1208 read the NUMA configuration directly from the builtin Northbridge 1209 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1210 which also takes priority if both are compiled in. 1211 1212config X86_64_ACPI_NUMA 1213 def_bool y 1214 prompt "ACPI NUMA detection" 1215 depends on X86_64 && NUMA && ACPI && PCI 1216 select ACPI_NUMA 1217 ---help--- 1218 Enable ACPI SRAT based node topology detection. 1219 1220# Some NUMA nodes have memory ranges that span 1221# other nodes. Even though a pfn is valid and 1222# between a node's start and end pfns, it may not 1223# reside on that node. See memmap_init_zone() 1224# for details. 1225config NODES_SPAN_OTHER_NODES 1226 def_bool y 1227 depends on X86_64_ACPI_NUMA 1228 1229config NUMA_EMU 1230 bool "NUMA emulation" 1231 depends on NUMA 1232 ---help--- 1233 Enable NUMA emulation. A flat machine will be split 1234 into virtual nodes when booted with "numa=fake=N", where N is the 1235 number of nodes. This is only useful for debugging. 1236 1237config NODES_SHIFT 1238 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1239 range 1 10 1240 default "10" if MAXSMP 1241 default "6" if X86_64 1242 default "3" 1243 depends on NEED_MULTIPLE_NODES 1244 ---help--- 1245 Specify the maximum number of NUMA Nodes available on the target 1246 system. Increases memory reserved to accommodate various tables. 1247 1248config ARCH_HAVE_MEMORY_PRESENT 1249 def_bool y 1250 depends on X86_32 && DISCONTIGMEM 1251 1252config NEED_NODE_MEMMAP_SIZE 1253 def_bool y 1254 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1255 1256config ARCH_FLATMEM_ENABLE 1257 def_bool y 1258 depends on X86_32 && !NUMA 1259 1260config ARCH_DISCONTIGMEM_ENABLE 1261 def_bool y 1262 depends on NUMA && X86_32 1263 1264config ARCH_DISCONTIGMEM_DEFAULT 1265 def_bool y 1266 depends on NUMA && X86_32 1267 1268config ARCH_SPARSEMEM_ENABLE 1269 def_bool y 1270 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1271 select SPARSEMEM_STATIC if X86_32 1272 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1273 1274config ARCH_SPARSEMEM_DEFAULT 1275 def_bool y 1276 depends on X86_64 1277 1278config ARCH_SELECT_MEMORY_MODEL 1279 def_bool y 1280 depends on ARCH_SPARSEMEM_ENABLE 1281 1282config ARCH_MEMORY_PROBE 1283 bool "Enable sysfs memory/probe interface" 1284 depends on X86_64 && MEMORY_HOTPLUG 1285 help 1286 This option enables a sysfs memory/probe interface for testing. 1287 See Documentation/memory-hotplug.txt for more information. 1288 If you are unsure how to answer this question, answer N. 1289 1290config ARCH_PROC_KCORE_TEXT 1291 def_bool y 1292 depends on X86_64 && PROC_KCORE 1293 1294config ILLEGAL_POINTER_VALUE 1295 hex 1296 default 0 if X86_32 1297 default 0xdead000000000000 if X86_64 1298 1299source "mm/Kconfig" 1300 1301config HIGHPTE 1302 bool "Allocate 3rd-level pagetables from highmem" 1303 depends on HIGHMEM 1304 ---help--- 1305 The VM uses one page table entry for each page of physical memory. 1306 For systems with a lot of RAM, this can be wasteful of precious 1307 low memory. Setting this option will put user-space page table 1308 entries in high memory. 1309 1310config X86_CHECK_BIOS_CORRUPTION 1311 bool "Check for low memory corruption" 1312 ---help--- 1313 Periodically check for memory corruption in low memory, which 1314 is suspected to be caused by BIOS. Even when enabled in the 1315 configuration, it is disabled at runtime. Enable it by 1316 setting "memory_corruption_check=1" on the kernel command 1317 line. By default it scans the low 64k of memory every 60 1318 seconds; see the memory_corruption_check_size and 1319 memory_corruption_check_period parameters in 1320 Documentation/kernel-parameters.txt to adjust this. 1321 1322 When enabled with the default parameters, this option has 1323 almost no overhead, as it reserves a relatively small amount 1324 of memory and scans it infrequently. It both detects corruption 1325 and prevents it from affecting the running system. 1326 1327 It is, however, intended as a diagnostic tool; if repeatable 1328 BIOS-originated corruption always affects the same memory, 1329 you can use memmap= to prevent the kernel from using that 1330 memory. 1331 1332config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1333 bool "Set the default setting of memory_corruption_check" 1334 depends on X86_CHECK_BIOS_CORRUPTION 1335 default y 1336 ---help--- 1337 Set whether the default state of memory_corruption_check is 1338 on or off. 1339 1340config X86_RESERVE_LOW 1341 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1342 default 64 1343 range 4 640 1344 ---help--- 1345 Specify the amount of low memory to reserve for the BIOS. 1346 1347 The first page contains BIOS data structures that the kernel 1348 must not use, so that page must always be reserved. 1349 1350 By default we reserve the first 64K of physical RAM, as a 1351 number of BIOSes are known to corrupt that memory range 1352 during events such as suspend/resume or monitor cable 1353 insertion, so it must not be used by the kernel. 1354 1355 You can set this to 4 if you are absolutely sure that you 1356 trust the BIOS to get all its memory reservations and usages 1357 right. If you know your BIOS have problems beyond the 1358 default 64K area, you can set this to 640 to avoid using the 1359 entire low memory range. 1360 1361 If you have doubts about the BIOS (e.g. suspend/resume does 1362 not work or there's kernel crashes after certain hardware 1363 hotplug events) then you might want to enable 1364 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1365 typical corruption patterns. 1366 1367 Leave this to the default value of 64 if you are unsure. 1368 1369config MATH_EMULATION 1370 bool 1371 prompt "Math emulation" if X86_32 1372 ---help--- 1373 Linux can emulate a math coprocessor (used for floating point 1374 operations) if you don't have one. 486DX and Pentium processors have 1375 a math coprocessor built in, 486SX and 386 do not, unless you added 1376 a 487DX or 387, respectively. (The messages during boot time can 1377 give you some hints here ["man dmesg"].) Everyone needs either a 1378 coprocessor or this emulation. 1379 1380 If you don't have a math coprocessor, you need to say Y here; if you 1381 say Y here even though you have a coprocessor, the coprocessor will 1382 be used nevertheless. (This behavior can be changed with the kernel 1383 command line option "no387", which comes handy if your coprocessor 1384 is broken. Try "man bootparam" or see the documentation of your boot 1385 loader (lilo or loadlin) about how to pass options to the kernel at 1386 boot time.) This means that it is a good idea to say Y here if you 1387 intend to use this kernel on different machines. 1388 1389 More information about the internals of the Linux math coprocessor 1390 emulation can be found in <file:arch/x86/math-emu/README>. 1391 1392 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1393 kernel, it won't hurt. 1394 1395config MTRR 1396 def_bool y 1397 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1398 ---help--- 1399 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1400 the Memory Type Range Registers (MTRRs) may be used to control 1401 processor access to memory ranges. This is most useful if you have 1402 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1403 allows bus write transfers to be combined into a larger transfer 1404 before bursting over the PCI/AGP bus. This can increase performance 1405 of image write operations 2.5 times or more. Saying Y here creates a 1406 /proc/mtrr file which may be used to manipulate your processor's 1407 MTRRs. Typically the X server should use this. 1408 1409 This code has a reasonably generic interface so that similar 1410 control registers on other processors can be easily supported 1411 as well: 1412 1413 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1414 Registers (ARRs) which provide a similar functionality to MTRRs. For 1415 these, the ARRs are used to emulate the MTRRs. 1416 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1417 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1418 write-combining. All of these processors are supported by this code 1419 and it makes sense to say Y here if you have one of them. 1420 1421 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1422 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1423 can lead to all sorts of problems, so it's good to say Y here. 1424 1425 You can safely say Y even if your machine doesn't have MTRRs, you'll 1426 just add about 9 KB to your kernel. 1427 1428 See <file:Documentation/x86/mtrr.txt> for more information. 1429 1430config MTRR_SANITIZER 1431 def_bool y 1432 prompt "MTRR cleanup support" 1433 depends on MTRR 1434 ---help--- 1435 Convert MTRR layout from continuous to discrete, so X drivers can 1436 add writeback entries. 1437 1438 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1439 The largest mtrr entry size for a continuous block can be set with 1440 mtrr_chunk_size. 1441 1442 If unsure, say Y. 1443 1444config MTRR_SANITIZER_ENABLE_DEFAULT 1445 int "MTRR cleanup enable value (0-1)" 1446 range 0 1 1447 default "0" 1448 depends on MTRR_SANITIZER 1449 ---help--- 1450 Enable mtrr cleanup default value 1451 1452config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1453 int "MTRR cleanup spare reg num (0-7)" 1454 range 0 7 1455 default "1" 1456 depends on MTRR_SANITIZER 1457 ---help--- 1458 mtrr cleanup spare entries default, it can be changed via 1459 mtrr_spare_reg_nr=N on the kernel command line. 1460 1461config X86_PAT 1462 def_bool y 1463 prompt "x86 PAT support" if EXPERT 1464 depends on MTRR 1465 ---help--- 1466 Use PAT attributes to setup page level cache control. 1467 1468 PATs are the modern equivalents of MTRRs and are much more 1469 flexible than MTRRs. 1470 1471 Say N here if you see bootup problems (boot crash, boot hang, 1472 spontaneous reboots) or a non-working video driver. 1473 1474 If unsure, say Y. 1475 1476config ARCH_USES_PG_UNCACHED 1477 def_bool y 1478 depends on X86_PAT 1479 1480config ARCH_RANDOM 1481 def_bool y 1482 prompt "x86 architectural random number generator" if EXPERT 1483 ---help--- 1484 Enable the x86 architectural RDRAND instruction 1485 (Intel Bull Mountain technology) to generate random numbers. 1486 If supported, this is a high bandwidth, cryptographically 1487 secure hardware random number generator. 1488 1489config X86_SMAP 1490 def_bool y 1491 prompt "Supervisor Mode Access Prevention" if EXPERT 1492 ---help--- 1493 Supervisor Mode Access Prevention (SMAP) is a security 1494 feature in newer Intel processors. There is a small 1495 performance cost if this enabled and turned on; there is 1496 also a small increase in the kernel size if this is enabled. 1497 1498 If unsure, say Y. 1499 1500config EFI 1501 bool "EFI runtime service support" 1502 depends on ACPI 1503 select UCS2_STRING 1504 ---help--- 1505 This enables the kernel to use EFI runtime services that are 1506 available (such as the EFI variable services). 1507 1508 This option is only useful on systems that have EFI firmware. 1509 In addition, you should use the latest ELILO loader available 1510 at <http://elilo.sourceforge.net> in order to take advantage 1511 of EFI runtime services. However, even with this option, the 1512 resultant kernel should continue to boot on existing non-EFI 1513 platforms. 1514 1515config EFI_STUB 1516 bool "EFI stub support" 1517 depends on EFI 1518 ---help--- 1519 This kernel feature allows a bzImage to be loaded directly 1520 by EFI firmware without the use of a bootloader. 1521 1522 See Documentation/efi-stub.txt for more information. 1523 1524config EFI_MIXED 1525 bool "EFI mixed-mode support" 1526 depends on EFI_STUB && X86_64 1527 ---help--- 1528 Enabling this feature allows a 64-bit kernel to be booted 1529 on a 32-bit firmware, provided that your CPU supports 64-bit 1530 mode. 1531 1532 Note that it is not possible to boot a mixed-mode enabled 1533 kernel via the EFI boot stub - a bootloader that supports 1534 the EFI handover protocol must be used. 1535 1536 If unsure, say N. 1537 1538config SECCOMP 1539 def_bool y 1540 prompt "Enable seccomp to safely compute untrusted bytecode" 1541 ---help--- 1542 This kernel feature is useful for number crunching applications 1543 that may need to compute untrusted bytecode during their 1544 execution. By using pipes or other transports made available to 1545 the process as file descriptors supporting the read/write 1546 syscalls, it's possible to isolate those applications in 1547 their own address space using seccomp. Once seccomp is 1548 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1549 and the task is only allowed to execute a few safe syscalls 1550 defined by each seccomp mode. 1551 1552 If unsure, say Y. Only embedded should say N here. 1553 1554source kernel/Kconfig.hz 1555 1556config KEXEC 1557 bool "kexec system call" 1558 ---help--- 1559 kexec is a system call that implements the ability to shutdown your 1560 current kernel, and to start another kernel. It is like a reboot 1561 but it is independent of the system firmware. And like a reboot 1562 you can start any kernel with it, not just Linux. 1563 1564 The name comes from the similarity to the exec system call. 1565 1566 It is an ongoing process to be certain the hardware in a machine 1567 is properly shutdown, so do not be surprised if this code does not 1568 initially work for you. As of this writing the exact hardware 1569 interface is strongly in flux, so no good recommendation can be 1570 made. 1571 1572config CRASH_DUMP 1573 bool "kernel crash dumps" 1574 depends on X86_64 || (X86_32 && HIGHMEM) 1575 ---help--- 1576 Generate crash dump after being started by kexec. 1577 This should be normally only set in special crash dump kernels 1578 which are loaded in the main kernel with kexec-tools into 1579 a specially reserved region and then later executed after 1580 a crash by kdump/kexec. The crash dump kernel must be compiled 1581 to a memory address not used by the main kernel or BIOS using 1582 PHYSICAL_START, or it must be built as a relocatable image 1583 (CONFIG_RELOCATABLE=y). 1584 For more details see Documentation/kdump/kdump.txt 1585 1586config KEXEC_JUMP 1587 bool "kexec jump" 1588 depends on KEXEC && HIBERNATION 1589 ---help--- 1590 Jump between original kernel and kexeced kernel and invoke 1591 code in physical address mode via KEXEC 1592 1593config PHYSICAL_START 1594 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1595 default "0x1000000" 1596 ---help--- 1597 This gives the physical address where the kernel is loaded. 1598 1599 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1600 bzImage will decompress itself to above physical address and 1601 run from there. Otherwise, bzImage will run from the address where 1602 it has been loaded by the boot loader and will ignore above physical 1603 address. 1604 1605 In normal kdump cases one does not have to set/change this option 1606 as now bzImage can be compiled as a completely relocatable image 1607 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1608 address. This option is mainly useful for the folks who don't want 1609 to use a bzImage for capturing the crash dump and want to use a 1610 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1611 to be specifically compiled to run from a specific memory area 1612 (normally a reserved region) and this option comes handy. 1613 1614 So if you are using bzImage for capturing the crash dump, 1615 leave the value here unchanged to 0x1000000 and set 1616 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1617 for capturing the crash dump change this value to start of 1618 the reserved region. In other words, it can be set based on 1619 the "X" value as specified in the "crashkernel=YM@XM" 1620 command line boot parameter passed to the panic-ed 1621 kernel. Please take a look at Documentation/kdump/kdump.txt 1622 for more details about crash dumps. 1623 1624 Usage of bzImage for capturing the crash dump is recommended as 1625 one does not have to build two kernels. Same kernel can be used 1626 as production kernel and capture kernel. Above option should have 1627 gone away after relocatable bzImage support is introduced. But it 1628 is present because there are users out there who continue to use 1629 vmlinux for dump capture. This option should go away down the 1630 line. 1631 1632 Don't change this unless you know what you are doing. 1633 1634config RELOCATABLE 1635 bool "Build a relocatable kernel" 1636 default y 1637 ---help--- 1638 This builds a kernel image that retains relocation information 1639 so it can be loaded someplace besides the default 1MB. 1640 The relocations tend to make the kernel binary about 10% larger, 1641 but are discarded at runtime. 1642 1643 One use is for the kexec on panic case where the recovery kernel 1644 must live at a different physical address than the primary 1645 kernel. 1646 1647 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1648 it has been loaded at and the compile time physical address 1649 (CONFIG_PHYSICAL_START) is used as the minimum location. 1650 1651config RANDOMIZE_BASE 1652 bool "Randomize the address of the kernel image" 1653 depends on RELOCATABLE 1654 depends on !HIBERNATION 1655 default n 1656 ---help--- 1657 Randomizes the physical and virtual address at which the 1658 kernel image is decompressed, as a security feature that 1659 deters exploit attempts relying on knowledge of the location 1660 of kernel internals. 1661 1662 Entropy is generated using the RDRAND instruction if it is 1663 supported. If RDTSC is supported, it is used as well. If 1664 neither RDRAND nor RDTSC are supported, then randomness is 1665 read from the i8254 timer. 1666 1667 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1668 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1669 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1670 minimum of 2MiB, only 10 bits of entropy is theoretically 1671 possible. At best, due to page table layouts, 64-bit can use 1672 9 bits of entropy and 32-bit uses 8 bits. 1673 1674 If unsure, say N. 1675 1676config RANDOMIZE_BASE_MAX_OFFSET 1677 hex "Maximum kASLR offset allowed" if EXPERT 1678 depends on RANDOMIZE_BASE 1679 range 0x0 0x20000000 if X86_32 1680 default "0x20000000" if X86_32 1681 range 0x0 0x40000000 if X86_64 1682 default "0x40000000" if X86_64 1683 ---help--- 1684 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1685 memory is used to determine the maximal offset in bytes that will 1686 be applied to the kernel when kernel Address Space Layout 1687 Randomization (kASLR) is active. This must be a multiple of 1688 PHYSICAL_ALIGN. 1689 1690 On 32-bit this is limited to 512MiB by page table layouts. The 1691 default is 512MiB. 1692 1693 On 64-bit this is limited by how the kernel fixmap page table is 1694 positioned, so this cannot be larger than 1GiB currently. Without 1695 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1696 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1697 modules area will shrink to compensate, up to the current maximum 1698 1GiB to 1GiB split. The default is 1GiB. 1699 1700 If unsure, leave at the default value. 1701 1702# Relocation on x86 needs some additional build support 1703config X86_NEED_RELOCS 1704 def_bool y 1705 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1706 1707config PHYSICAL_ALIGN 1708 hex "Alignment value to which kernel should be aligned" 1709 default "0x200000" 1710 range 0x2000 0x1000000 if X86_32 1711 range 0x200000 0x1000000 if X86_64 1712 ---help--- 1713 This value puts the alignment restrictions on physical address 1714 where kernel is loaded and run from. Kernel is compiled for an 1715 address which meets above alignment restriction. 1716 1717 If bootloader loads the kernel at a non-aligned address and 1718 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1719 address aligned to above value and run from there. 1720 1721 If bootloader loads the kernel at a non-aligned address and 1722 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1723 load address and decompress itself to the address it has been 1724 compiled for and run from there. The address for which kernel is 1725 compiled already meets above alignment restrictions. Hence the 1726 end result is that kernel runs from a physical address meeting 1727 above alignment restrictions. 1728 1729 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1730 this value must be a multiple of 0x200000. 1731 1732 Don't change this unless you know what you are doing. 1733 1734config HOTPLUG_CPU 1735 bool "Support for hot-pluggable CPUs" 1736 depends on SMP 1737 ---help--- 1738 Say Y here to allow turning CPUs off and on. CPUs can be 1739 controlled through /sys/devices/system/cpu. 1740 ( Note: power management support will enable this option 1741 automatically on SMP systems. ) 1742 Say N if you want to disable CPU hotplug. 1743 1744config BOOTPARAM_HOTPLUG_CPU0 1745 bool "Set default setting of cpu0_hotpluggable" 1746 default n 1747 depends on HOTPLUG_CPU 1748 ---help--- 1749 Set whether default state of cpu0_hotpluggable is on or off. 1750 1751 Say Y here to enable CPU0 hotplug by default. If this switch 1752 is turned on, there is no need to give cpu0_hotplug kernel 1753 parameter and the CPU0 hotplug feature is enabled by default. 1754 1755 Please note: there are two known CPU0 dependencies if you want 1756 to enable the CPU0 hotplug feature either by this switch or by 1757 cpu0_hotplug kernel parameter. 1758 1759 First, resume from hibernate or suspend always starts from CPU0. 1760 So hibernate and suspend are prevented if CPU0 is offline. 1761 1762 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1763 offline if any interrupt can not migrate out of CPU0. There may 1764 be other CPU0 dependencies. 1765 1766 Please make sure the dependencies are under your control before 1767 you enable this feature. 1768 1769 Say N if you don't want to enable CPU0 hotplug feature by default. 1770 You still can enable the CPU0 hotplug feature at boot by kernel 1771 parameter cpu0_hotplug. 1772 1773config DEBUG_HOTPLUG_CPU0 1774 def_bool n 1775 prompt "Debug CPU0 hotplug" 1776 depends on HOTPLUG_CPU 1777 ---help--- 1778 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1779 soon as possible and boots up userspace with CPU0 offlined. User 1780 can online CPU0 back after boot time. 1781 1782 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1783 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1784 compilation or giving cpu0_hotplug kernel parameter at boot. 1785 1786 If unsure, say N. 1787 1788config COMPAT_VDSO 1789 def_bool n 1790 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 1791 depends on X86_32 || IA32_EMULATION 1792 ---help--- 1793 Certain buggy versions of glibc will crash if they are 1794 presented with a 32-bit vDSO that is not mapped at the address 1795 indicated in its segment table. 1796 1797 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 1798 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 1799 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 1800 the only released version with the bug, but OpenSUSE 9 1801 contains a buggy "glibc 2.3.2". 1802 1803 The symptom of the bug is that everything crashes on startup, saying: 1804 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 1805 1806 Saying Y here changes the default value of the vdso32 boot 1807 option from 1 to 0, which turns off the 32-bit vDSO entirely. 1808 This works around the glibc bug but hurts performance. 1809 1810 If unsure, say N: if you are compiling your own kernel, you 1811 are unlikely to be using a buggy version of glibc. 1812 1813config CMDLINE_BOOL 1814 bool "Built-in kernel command line" 1815 ---help--- 1816 Allow for specifying boot arguments to the kernel at 1817 build time. On some systems (e.g. embedded ones), it is 1818 necessary or convenient to provide some or all of the 1819 kernel boot arguments with the kernel itself (that is, 1820 to not rely on the boot loader to provide them.) 1821 1822 To compile command line arguments into the kernel, 1823 set this option to 'Y', then fill in the 1824 the boot arguments in CONFIG_CMDLINE. 1825 1826 Systems with fully functional boot loaders (i.e. non-embedded) 1827 should leave this option set to 'N'. 1828 1829config CMDLINE 1830 string "Built-in kernel command string" 1831 depends on CMDLINE_BOOL 1832 default "" 1833 ---help--- 1834 Enter arguments here that should be compiled into the kernel 1835 image and used at boot time. If the boot loader provides a 1836 command line at boot time, it is appended to this string to 1837 form the full kernel command line, when the system boots. 1838 1839 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1840 change this behavior. 1841 1842 In most cases, the command line (whether built-in or provided 1843 by the boot loader) should specify the device for the root 1844 file system. 1845 1846config CMDLINE_OVERRIDE 1847 bool "Built-in command line overrides boot loader arguments" 1848 depends on CMDLINE_BOOL 1849 ---help--- 1850 Set this option to 'Y' to have the kernel ignore the boot loader 1851 command line, and use ONLY the built-in command line. 1852 1853 This is used to work around broken boot loaders. This should 1854 be set to 'N' under normal conditions. 1855 1856endmenu 1857 1858config ARCH_ENABLE_MEMORY_HOTPLUG 1859 def_bool y 1860 depends on X86_64 || (X86_32 && HIGHMEM) 1861 1862config ARCH_ENABLE_MEMORY_HOTREMOVE 1863 def_bool y 1864 depends on MEMORY_HOTPLUG 1865 1866config USE_PERCPU_NUMA_NODE_ID 1867 def_bool y 1868 depends on NUMA 1869 1870config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1871 def_bool y 1872 depends on X86_64 || X86_PAE 1873 1874menu "Power management and ACPI options" 1875 1876config ARCH_HIBERNATION_HEADER 1877 def_bool y 1878 depends on X86_64 && HIBERNATION 1879 1880source "kernel/power/Kconfig" 1881 1882source "drivers/acpi/Kconfig" 1883 1884source "drivers/sfi/Kconfig" 1885 1886config X86_APM_BOOT 1887 def_bool y 1888 depends on APM 1889 1890menuconfig APM 1891 tristate "APM (Advanced Power Management) BIOS support" 1892 depends on X86_32 && PM_SLEEP 1893 ---help--- 1894 APM is a BIOS specification for saving power using several different 1895 techniques. This is mostly useful for battery powered laptops with 1896 APM compliant BIOSes. If you say Y here, the system time will be 1897 reset after a RESUME operation, the /proc/apm device will provide 1898 battery status information, and user-space programs will receive 1899 notification of APM "events" (e.g. battery status change). 1900 1901 If you select "Y" here, you can disable actual use of the APM 1902 BIOS by passing the "apm=off" option to the kernel at boot time. 1903 1904 Note that the APM support is almost completely disabled for 1905 machines with more than one CPU. 1906 1907 In order to use APM, you will need supporting software. For location 1908 and more information, read <file:Documentation/power/apm-acpi.txt> 1909 and the Battery Powered Linux mini-HOWTO, available from 1910 <http://www.tldp.org/docs.html#howto>. 1911 1912 This driver does not spin down disk drives (see the hdparm(8) 1913 manpage ("man 8 hdparm") for that), and it doesn't turn off 1914 VESA-compliant "green" monitors. 1915 1916 This driver does not support the TI 4000M TravelMate and the ACER 1917 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1918 desktop machines also don't have compliant BIOSes, and this driver 1919 may cause those machines to panic during the boot phase. 1920 1921 Generally, if you don't have a battery in your machine, there isn't 1922 much point in using this driver and you should say N. If you get 1923 random kernel OOPSes or reboots that don't seem to be related to 1924 anything, try disabling/enabling this option (or disabling/enabling 1925 APM in your BIOS). 1926 1927 Some other things you should try when experiencing seemingly random, 1928 "weird" problems: 1929 1930 1) make sure that you have enough swap space and that it is 1931 enabled. 1932 2) pass the "no-hlt" option to the kernel 1933 3) switch on floating point emulation in the kernel and pass 1934 the "no387" option to the kernel 1935 4) pass the "floppy=nodma" option to the kernel 1936 5) pass the "mem=4M" option to the kernel (thereby disabling 1937 all but the first 4 MB of RAM) 1938 6) make sure that the CPU is not over clocked. 1939 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1940 8) disable the cache from your BIOS settings 1941 9) install a fan for the video card or exchange video RAM 1942 10) install a better fan for the CPU 1943 11) exchange RAM chips 1944 12) exchange the motherboard. 1945 1946 To compile this driver as a module, choose M here: the 1947 module will be called apm. 1948 1949if APM 1950 1951config APM_IGNORE_USER_SUSPEND 1952 bool "Ignore USER SUSPEND" 1953 ---help--- 1954 This option will ignore USER SUSPEND requests. On machines with a 1955 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1956 series notebooks, it is necessary to say Y because of a BIOS bug. 1957 1958config APM_DO_ENABLE 1959 bool "Enable PM at boot time" 1960 ---help--- 1961 Enable APM features at boot time. From page 36 of the APM BIOS 1962 specification: "When disabled, the APM BIOS does not automatically 1963 power manage devices, enter the Standby State, enter the Suspend 1964 State, or take power saving steps in response to CPU Idle calls." 1965 This driver will make CPU Idle calls when Linux is idle (unless this 1966 feature is turned off -- see "Do CPU IDLE calls", below). This 1967 should always save battery power, but more complicated APM features 1968 will be dependent on your BIOS implementation. You may need to turn 1969 this option off if your computer hangs at boot time when using APM 1970 support, or if it beeps continuously instead of suspending. Turn 1971 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1972 T400CDT. This is off by default since most machines do fine without 1973 this feature. 1974 1975config APM_CPU_IDLE 1976 depends on CPU_IDLE 1977 bool "Make CPU Idle calls when idle" 1978 ---help--- 1979 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1980 On some machines, this can activate improved power savings, such as 1981 a slowed CPU clock rate, when the machine is idle. These idle calls 1982 are made after the idle loop has run for some length of time (e.g., 1983 333 mS). On some machines, this will cause a hang at boot time or 1984 whenever the CPU becomes idle. (On machines with more than one CPU, 1985 this option does nothing.) 1986 1987config APM_DISPLAY_BLANK 1988 bool "Enable console blanking using APM" 1989 ---help--- 1990 Enable console blanking using the APM. Some laptops can use this to 1991 turn off the LCD backlight when the screen blanker of the Linux 1992 virtual console blanks the screen. Note that this is only used by 1993 the virtual console screen blanker, and won't turn off the backlight 1994 when using the X Window system. This also doesn't have anything to 1995 do with your VESA-compliant power-saving monitor. Further, this 1996 option doesn't work for all laptops -- it might not turn off your 1997 backlight at all, or it might print a lot of errors to the console, 1998 especially if you are using gpm. 1999 2000config APM_ALLOW_INTS 2001 bool "Allow interrupts during APM BIOS calls" 2002 ---help--- 2003 Normally we disable external interrupts while we are making calls to 2004 the APM BIOS as a measure to lessen the effects of a badly behaving 2005 BIOS implementation. The BIOS should reenable interrupts if it 2006 needs to. Unfortunately, some BIOSes do not -- especially those in 2007 many of the newer IBM Thinkpads. If you experience hangs when you 2008 suspend, try setting this to Y. Otherwise, say N. 2009 2010endif # APM 2011 2012source "drivers/cpufreq/Kconfig" 2013 2014source "drivers/cpuidle/Kconfig" 2015 2016source "drivers/idle/Kconfig" 2017 2018endmenu 2019 2020 2021menu "Bus options (PCI etc.)" 2022 2023config PCI 2024 bool "PCI support" 2025 default y 2026 ---help--- 2027 Find out whether you have a PCI motherboard. PCI is the name of a 2028 bus system, i.e. the way the CPU talks to the other stuff inside 2029 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2030 VESA. If you have PCI, say Y, otherwise N. 2031 2032choice 2033 prompt "PCI access mode" 2034 depends on X86_32 && PCI 2035 default PCI_GOANY 2036 ---help--- 2037 On PCI systems, the BIOS can be used to detect the PCI devices and 2038 determine their configuration. However, some old PCI motherboards 2039 have BIOS bugs and may crash if this is done. Also, some embedded 2040 PCI-based systems don't have any BIOS at all. Linux can also try to 2041 detect the PCI hardware directly without using the BIOS. 2042 2043 With this option, you can specify how Linux should detect the 2044 PCI devices. If you choose "BIOS", the BIOS will be used, 2045 if you choose "Direct", the BIOS won't be used, and if you 2046 choose "MMConfig", then PCI Express MMCONFIG will be used. 2047 If you choose "Any", the kernel will try MMCONFIG, then the 2048 direct access method and falls back to the BIOS if that doesn't 2049 work. If unsure, go with the default, which is "Any". 2050 2051config PCI_GOBIOS 2052 bool "BIOS" 2053 2054config PCI_GOMMCONFIG 2055 bool "MMConfig" 2056 2057config PCI_GODIRECT 2058 bool "Direct" 2059 2060config PCI_GOOLPC 2061 bool "OLPC XO-1" 2062 depends on OLPC 2063 2064config PCI_GOANY 2065 bool "Any" 2066 2067endchoice 2068 2069config PCI_BIOS 2070 def_bool y 2071 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2072 2073# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2074config PCI_DIRECT 2075 def_bool y 2076 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2077 2078config PCI_MMCONFIG 2079 def_bool y 2080 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2081 2082config PCI_OLPC 2083 def_bool y 2084 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2085 2086config PCI_XEN 2087 def_bool y 2088 depends on PCI && XEN 2089 select SWIOTLB_XEN 2090 2091config PCI_DOMAINS 2092 def_bool y 2093 depends on PCI 2094 2095config PCI_MMCONFIG 2096 bool "Support mmconfig PCI config space access" 2097 depends on X86_64 && PCI && ACPI 2098 2099config PCI_CNB20LE_QUIRK 2100 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2101 depends on PCI 2102 help 2103 Read the PCI windows out of the CNB20LE host bridge. This allows 2104 PCI hotplug to work on systems with the CNB20LE chipset which do 2105 not have ACPI. 2106 2107 There's no public spec for this chipset, and this functionality 2108 is known to be incomplete. 2109 2110 You should say N unless you know you need this. 2111 2112source "drivers/pci/pcie/Kconfig" 2113 2114source "drivers/pci/Kconfig" 2115 2116# x86_64 have no ISA slots, but can have ISA-style DMA. 2117config ISA_DMA_API 2118 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2119 default y 2120 help 2121 Enables ISA-style DMA support for devices requiring such controllers. 2122 If unsure, say Y. 2123 2124if X86_32 2125 2126config ISA 2127 bool "ISA support" 2128 ---help--- 2129 Find out whether you have ISA slots on your motherboard. ISA is the 2130 name of a bus system, i.e. the way the CPU talks to the other stuff 2131 inside your box. Other bus systems are PCI, EISA, MicroChannel 2132 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2133 newer boards don't support it. If you have ISA, say Y, otherwise N. 2134 2135config EISA 2136 bool "EISA support" 2137 depends on ISA 2138 ---help--- 2139 The Extended Industry Standard Architecture (EISA) bus was 2140 developed as an open alternative to the IBM MicroChannel bus. 2141 2142 The EISA bus provided some of the features of the IBM MicroChannel 2143 bus while maintaining backward compatibility with cards made for 2144 the older ISA bus. The EISA bus saw limited use between 1988 and 2145 1995 when it was made obsolete by the PCI bus. 2146 2147 Say Y here if you are building a kernel for an EISA-based machine. 2148 2149 Otherwise, say N. 2150 2151source "drivers/eisa/Kconfig" 2152 2153config SCx200 2154 tristate "NatSemi SCx200 support" 2155 ---help--- 2156 This provides basic support for National Semiconductor's 2157 (now AMD's) Geode processors. The driver probes for the 2158 PCI-IDs of several on-chip devices, so its a good dependency 2159 for other scx200_* drivers. 2160 2161 If compiled as a module, the driver is named scx200. 2162 2163config SCx200HR_TIMER 2164 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2165 depends on SCx200 2166 default y 2167 ---help--- 2168 This driver provides a clocksource built upon the on-chip 2169 27MHz high-resolution timer. Its also a workaround for 2170 NSC Geode SC-1100's buggy TSC, which loses time when the 2171 processor goes idle (as is done by the scheduler). The 2172 other workaround is idle=poll boot option. 2173 2174config OLPC 2175 bool "One Laptop Per Child support" 2176 depends on !X86_PAE 2177 select GPIOLIB 2178 select OF 2179 select OF_PROMTREE 2180 select IRQ_DOMAIN 2181 ---help--- 2182 Add support for detecting the unique features of the OLPC 2183 XO hardware. 2184 2185config OLPC_XO1_PM 2186 bool "OLPC XO-1 Power Management" 2187 depends on OLPC && MFD_CS5535 && PM_SLEEP 2188 select MFD_CORE 2189 ---help--- 2190 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2191 2192config OLPC_XO1_RTC 2193 bool "OLPC XO-1 Real Time Clock" 2194 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2195 ---help--- 2196 Add support for the XO-1 real time clock, which can be used as a 2197 programmable wakeup source. 2198 2199config OLPC_XO1_SCI 2200 bool "OLPC XO-1 SCI extras" 2201 depends on OLPC && OLPC_XO1_PM 2202 depends on INPUT=y 2203 select POWER_SUPPLY 2204 select GPIO_CS5535 2205 select MFD_CORE 2206 ---help--- 2207 Add support for SCI-based features of the OLPC XO-1 laptop: 2208 - EC-driven system wakeups 2209 - Power button 2210 - Ebook switch 2211 - Lid switch 2212 - AC adapter status updates 2213 - Battery status updates 2214 2215config OLPC_XO15_SCI 2216 bool "OLPC XO-1.5 SCI extras" 2217 depends on OLPC && ACPI 2218 select POWER_SUPPLY 2219 ---help--- 2220 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2221 - EC-driven system wakeups 2222 - AC adapter status updates 2223 - Battery status updates 2224 2225config ALIX 2226 bool "PCEngines ALIX System Support (LED setup)" 2227 select GPIOLIB 2228 ---help--- 2229 This option enables system support for the PCEngines ALIX. 2230 At present this just sets up LEDs for GPIO control on 2231 ALIX2/3/6 boards. However, other system specific setup should 2232 get added here. 2233 2234 Note: You must still enable the drivers for GPIO and LED support 2235 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2236 2237 Note: You have to set alix.force=1 for boards with Award BIOS. 2238 2239config NET5501 2240 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2241 select GPIOLIB 2242 ---help--- 2243 This option enables system support for the Soekris Engineering net5501. 2244 2245config GEOS 2246 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2247 select GPIOLIB 2248 depends on DMI 2249 ---help--- 2250 This option enables system support for the Traverse Technologies GEOS. 2251 2252config TS5500 2253 bool "Technologic Systems TS-5500 platform support" 2254 depends on MELAN 2255 select CHECK_SIGNATURE 2256 select NEW_LEDS 2257 select LEDS_CLASS 2258 ---help--- 2259 This option enables system support for the Technologic Systems TS-5500. 2260 2261endif # X86_32 2262 2263config AMD_NB 2264 def_bool y 2265 depends on CPU_SUP_AMD && PCI 2266 2267source "drivers/pcmcia/Kconfig" 2268 2269source "drivers/pci/hotplug/Kconfig" 2270 2271config RAPIDIO 2272 tristate "RapidIO support" 2273 depends on PCI 2274 default n 2275 help 2276 If enabled this option will include drivers and the core 2277 infrastructure code to support RapidIO interconnect devices. 2278 2279source "drivers/rapidio/Kconfig" 2280 2281config X86_SYSFB 2282 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2283 help 2284 Firmwares often provide initial graphics framebuffers so the BIOS, 2285 bootloader or kernel can show basic video-output during boot for 2286 user-guidance and debugging. Historically, x86 used the VESA BIOS 2287 Extensions and EFI-framebuffers for this, which are mostly limited 2288 to x86. 2289 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2290 framebuffers so the new generic system-framebuffer drivers can be 2291 used on x86. If the framebuffer is not compatible with the generic 2292 modes, it is adverticed as fallback platform framebuffer so legacy 2293 drivers like efifb, vesafb and uvesafb can pick it up. 2294 If this option is not selected, all system framebuffers are always 2295 marked as fallback platform framebuffers as usual. 2296 2297 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2298 not be able to pick up generic system framebuffers if this option 2299 is selected. You are highly encouraged to enable simplefb as 2300 replacement if you select this option. simplefb can correctly deal 2301 with generic system framebuffers. But you should still keep vesafb 2302 and others enabled as fallback if a system framebuffer is 2303 incompatible with simplefb. 2304 2305 If unsure, say Y. 2306 2307endmenu 2308 2309 2310menu "Executable file formats / Emulations" 2311 2312source "fs/Kconfig.binfmt" 2313 2314config IA32_EMULATION 2315 bool "IA32 Emulation" 2316 depends on X86_64 2317 select BINFMT_ELF 2318 select COMPAT_BINFMT_ELF 2319 select HAVE_UID16 2320 ---help--- 2321 Include code to run legacy 32-bit programs under a 2322 64-bit kernel. You should likely turn this on, unless you're 2323 100% sure that you don't have any 32-bit programs left. 2324 2325config IA32_AOUT 2326 tristate "IA32 a.out support" 2327 depends on IA32_EMULATION 2328 ---help--- 2329 Support old a.out binaries in the 32bit emulation. 2330 2331config X86_X32 2332 bool "x32 ABI for 64-bit mode" 2333 depends on X86_64 && IA32_EMULATION 2334 ---help--- 2335 Include code to run binaries for the x32 native 32-bit ABI 2336 for 64-bit processors. An x32 process gets access to the 2337 full 64-bit register file and wide data path while leaving 2338 pointers at 32 bits for smaller memory footprint. 2339 2340 You will need a recent binutils (2.22 or later) with 2341 elf32_x86_64 support enabled to compile a kernel with this 2342 option set. 2343 2344config COMPAT 2345 def_bool y 2346 depends on IA32_EMULATION || X86_X32 2347 select ARCH_WANT_OLD_COMPAT_IPC 2348 2349if COMPAT 2350config COMPAT_FOR_U64_ALIGNMENT 2351 def_bool y 2352 2353config SYSVIPC_COMPAT 2354 def_bool y 2355 depends on SYSVIPC 2356 2357config KEYS_COMPAT 2358 def_bool y 2359 depends on KEYS 2360endif 2361 2362endmenu 2363 2364 2365config HAVE_ATOMIC_IOMAP 2366 def_bool y 2367 depends on X86_32 2368 2369config X86_DEV_DMA_OPS 2370 bool 2371 depends on X86_64 || STA2X11 2372 2373config X86_DMA_REMAP 2374 bool 2375 depends on STA2X11 2376 2377config IOSF_MBI 2378 bool 2379 depends on PCI 2380 ---help--- 2381 To be selected by modules requiring access to the Intel OnChip System 2382 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms 2383 enumerable by PCI. 2384 2385source "net/Kconfig" 2386 2387source "drivers/Kconfig" 2388 2389source "drivers/firmware/Kconfig" 2390 2391source "fs/Kconfig" 2392 2393source "arch/x86/Kconfig.debug" 2394 2395source "security/Kconfig" 2396 2397source "crypto/Kconfig" 2398 2399source "arch/x86/kvm/Kconfig" 2400 2401source "lib/Kconfig" 2402