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