1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH != "i386" 5 ---help--- 6 Say yes to build a 64-bit kernel - formerly known as x86_64 7 Say no to build a 32-bit kernel - formerly known as i386 8 9config X86_32 10 def_bool y 11 depends on !64BIT 12 select CLKSRC_I8253 13 select HAVE_UID16 14 15config X86_64 16 def_bool y 17 depends on 64BIT 18 select X86_DEV_DMA_OPS 19 select ARCH_USE_CMPXCHG_LOCKREF 20 21### Arch settings 22config X86 23 def_bool y 24 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 26 select ARCH_HAS_FAST_MULTIPLIER 27 select ARCH_HAS_GCOV_PROFILE_ALL 28 select ARCH_MIGHT_HAVE_PC_PARPORT 29 select ARCH_MIGHT_HAVE_PC_SERIO 30 select HAVE_AOUT if X86_32 31 select HAVE_UNSTABLE_SCHED_CLOCK 32 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 33 select ARCH_SUPPORTS_INT128 if X86_64 34 select HAVE_IDE 35 select HAVE_OPROFILE 36 select HAVE_PCSPKR_PLATFORM 37 select HAVE_PERF_EVENTS 38 select HAVE_IOREMAP_PROT 39 select HAVE_KPROBES 40 select HAVE_MEMBLOCK 41 select HAVE_MEMBLOCK_NODE_MAP 42 select ARCH_DISCARD_MEMBLOCK 43 select ARCH_WANT_OPTIONAL_GPIOLIB 44 select ARCH_WANT_FRAME_POINTERS 45 select HAVE_DMA_ATTRS 46 select HAVE_DMA_CONTIGUOUS 47 select HAVE_KRETPROBES 48 select GENERIC_EARLY_IOREMAP 49 select HAVE_OPTPROBES 50 select HAVE_KPROBES_ON_FTRACE 51 select HAVE_FTRACE_MCOUNT_RECORD 52 select HAVE_FENTRY if X86_64 53 select HAVE_C_RECORDMCOUNT 54 select HAVE_DYNAMIC_FTRACE 55 select HAVE_DYNAMIC_FTRACE_WITH_REGS 56 select HAVE_FUNCTION_TRACER 57 select HAVE_FUNCTION_GRAPH_TRACER 58 select HAVE_FUNCTION_GRAPH_FP_TEST 59 select HAVE_SYSCALL_TRACEPOINTS 60 select SYSCTL_EXCEPTION_TRACE 61 select HAVE_KVM 62 select HAVE_ARCH_KGDB 63 select HAVE_ARCH_TRACEHOOK 64 select HAVE_GENERIC_DMA_COHERENT if X86_32 65 select HAVE_EFFICIENT_UNALIGNED_ACCESS 66 select USER_STACKTRACE_SUPPORT 67 select HAVE_REGS_AND_STACK_ACCESS_API 68 select HAVE_DMA_API_DEBUG 69 select HAVE_KERNEL_GZIP 70 select HAVE_KERNEL_BZIP2 71 select HAVE_KERNEL_LZMA 72 select HAVE_KERNEL_XZ 73 select HAVE_KERNEL_LZO 74 select HAVE_KERNEL_LZ4 75 select HAVE_HW_BREAKPOINT 76 select HAVE_MIXED_BREAKPOINTS_REGS 77 select PERF_EVENTS 78 select HAVE_PERF_EVENTS_NMI 79 select HAVE_PERF_REGS 80 select HAVE_PERF_USER_STACK_DUMP 81 select HAVE_DEBUG_KMEMLEAK 82 select ANON_INODES 83 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 84 select HAVE_CMPXCHG_LOCAL 85 select HAVE_CMPXCHG_DOUBLE 86 select HAVE_ARCH_KMEMCHECK 87 select HAVE_USER_RETURN_NOTIFIER 88 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 89 select HAVE_ARCH_JUMP_LABEL 90 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 91 select SPARSE_IRQ 92 select GENERIC_FIND_FIRST_BIT 93 select GENERIC_IRQ_PROBE 94 select GENERIC_PENDING_IRQ if SMP 95 select GENERIC_IRQ_SHOW 96 select GENERIC_CLOCKEVENTS_MIN_ADJUST 97 select IRQ_FORCED_THREADING 98 select HAVE_BPF_JIT if X86_64 99 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 100 select ARCH_HAS_SG_CHAIN 101 select CLKEVT_I8253 102 select ARCH_HAVE_NMI_SAFE_CMPXCHG 103 select GENERIC_IOMAP 104 select DCACHE_WORD_ACCESS 105 select GENERIC_SMP_IDLE_THREAD 106 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 107 select HAVE_ARCH_SECCOMP_FILTER 108 select BUILDTIME_EXTABLE_SORT 109 select GENERIC_CMOS_UPDATE 110 select HAVE_ARCH_SOFT_DIRTY if X86_64 111 select CLOCKSOURCE_WATCHDOG 112 select GENERIC_CLOCKEVENTS 113 select ARCH_CLOCKSOURCE_DATA 114 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 115 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 116 select GENERIC_TIME_VSYSCALL 117 select GENERIC_STRNCPY_FROM_USER 118 select GENERIC_STRNLEN_USER 119 select HAVE_CONTEXT_TRACKING if X86_64 120 select HAVE_IRQ_TIME_ACCOUNTING 121 select VIRT_TO_BUS 122 select MODULES_USE_ELF_REL if X86_32 123 select MODULES_USE_ELF_RELA if X86_64 124 select CLONE_BACKWARDS if X86_32 125 select ARCH_USE_BUILTIN_BSWAP 126 select ARCH_USE_QUEUE_RWLOCK 127 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 128 select OLD_SIGACTION if X86_32 129 select COMPAT_OLD_SIGACTION if IA32_EMULATION 130 select RTC_LIB 131 select HAVE_DEBUG_STACKOVERFLOW 132 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 133 select HAVE_CC_STACKPROTECTOR 134 select GENERIC_CPU_AUTOPROBE 135 select HAVE_ARCH_AUDITSYSCALL 136 select ARCH_SUPPORTS_ATOMIC_RMW 137 select HAVE_ACPI_APEI if ACPI 138 select HAVE_ACPI_APEI_NMI if ACPI 139 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 140 select X86_FEATURE_NAMES if PROC_FS 141 142config INSTRUCTION_DECODER 143 def_bool y 144 depends on KPROBES || PERF_EVENTS || UPROBES 145 146config PERF_EVENTS_INTEL_UNCORE 147 def_bool y 148 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 149 150config OUTPUT_FORMAT 151 string 152 default "elf32-i386" if X86_32 153 default "elf64-x86-64" if X86_64 154 155config ARCH_DEFCONFIG 156 string 157 default "arch/x86/configs/i386_defconfig" if X86_32 158 default "arch/x86/configs/x86_64_defconfig" if X86_64 159 160config LOCKDEP_SUPPORT 161 def_bool y 162 163config STACKTRACE_SUPPORT 164 def_bool y 165 166config HAVE_LATENCYTOP_SUPPORT 167 def_bool y 168 169config MMU 170 def_bool y 171 172config SBUS 173 bool 174 175config NEED_DMA_MAP_STATE 176 def_bool y 177 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 178 179config NEED_SG_DMA_LENGTH 180 def_bool y 181 182config GENERIC_ISA_DMA 183 def_bool y 184 depends on ISA_DMA_API 185 186config GENERIC_BUG 187 def_bool y 188 depends on BUG 189 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 190 191config GENERIC_BUG_RELATIVE_POINTERS 192 bool 193 194config GENERIC_HWEIGHT 195 def_bool y 196 197config ARCH_MAY_HAVE_PC_FDC 198 def_bool y 199 depends on ISA_DMA_API 200 201config RWSEM_XCHGADD_ALGORITHM 202 def_bool y 203 204config GENERIC_CALIBRATE_DELAY 205 def_bool y 206 207config ARCH_HAS_CPU_RELAX 208 def_bool y 209 210config ARCH_HAS_CACHE_LINE_SIZE 211 def_bool y 212 213config HAVE_SETUP_PER_CPU_AREA 214 def_bool y 215 216config NEED_PER_CPU_EMBED_FIRST_CHUNK 217 def_bool y 218 219config NEED_PER_CPU_PAGE_FIRST_CHUNK 220 def_bool y 221 222config ARCH_HIBERNATION_POSSIBLE 223 def_bool y 224 225config ARCH_SUSPEND_POSSIBLE 226 def_bool y 227 228config ARCH_WANT_HUGE_PMD_SHARE 229 def_bool y 230 231config ARCH_WANT_GENERAL_HUGETLB 232 def_bool y 233 234config ZONE_DMA32 235 bool 236 default X86_64 237 238config AUDIT_ARCH 239 bool 240 default X86_64 241 242config ARCH_SUPPORTS_OPTIMIZED_INLINING 243 def_bool y 244 245config ARCH_SUPPORTS_DEBUG_PAGEALLOC 246 def_bool y 247 248config HAVE_INTEL_TXT 249 def_bool y 250 depends on INTEL_IOMMU && ACPI 251 252config X86_32_SMP 253 def_bool y 254 depends on X86_32 && SMP 255 256config X86_64_SMP 257 def_bool y 258 depends on X86_64 && SMP 259 260config X86_HT 261 def_bool y 262 depends on SMP 263 264config X86_32_LAZY_GS 265 def_bool y 266 depends on X86_32 && !CC_STACKPROTECTOR 267 268config ARCH_HWEIGHT_CFLAGS 269 string 270 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 271 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_64 272 273config ARCH_SUPPORTS_UPROBES 274 def_bool y 275 276config FIX_EARLYCON_MEM 277 def_bool y 278 279source "init/Kconfig" 280source "kernel/Kconfig.freezer" 281 282menu "Processor type and features" 283 284config ZONE_DMA 285 bool "DMA memory allocation support" if EXPERT 286 default y 287 help 288 DMA memory allocation support allows devices with less than 32-bit 289 addressing to allocate within the first 16MB of address space. 290 Disable if no such devices will be used. 291 292 If unsure, say Y. 293 294config SMP 295 bool "Symmetric multi-processing support" 296 ---help--- 297 This enables support for systems with more than one CPU. If you have 298 a system with only one CPU, say N. If you have a system with more 299 than one CPU, say Y. 300 301 If you say N here, the kernel will run on uni- and multiprocessor 302 machines, but will use only one CPU of a multiprocessor machine. If 303 you say Y here, the kernel will run on many, but not all, 304 uniprocessor machines. On a uniprocessor machine, the kernel 305 will run faster if you say N here. 306 307 Note that if you say Y here and choose architecture "586" or 308 "Pentium" under "Processor family", the kernel will not work on 486 309 architectures. Similarly, multiprocessor kernels for the "PPro" 310 architecture may not work on all Pentium based boards. 311 312 People using multiprocessor machines who say Y here should also say 313 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 314 Management" code will be disabled if you say Y here. 315 316 See also <file:Documentation/x86/i386/IO-APIC.txt>, 317 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 318 <http://www.tldp.org/docs.html#howto>. 319 320 If you don't know what to do here, say N. 321 322config X86_FEATURE_NAMES 323 bool "Processor feature human-readable names" if EMBEDDED 324 default y 325 ---help--- 326 This option compiles in a table of x86 feature bits and corresponding 327 names. This is required to support /proc/cpuinfo and a few kernel 328 messages. You can disable this to save space, at the expense of 329 making those few kernel messages show numeric feature bits instead. 330 331 If in doubt, say Y. 332 333config X86_X2APIC 334 bool "Support x2apic" 335 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 336 ---help--- 337 This enables x2apic support on CPUs that have this feature. 338 339 This allows 32-bit apic IDs (so it can support very large systems), 340 and accesses the local apic via MSRs not via mmio. 341 342 If you don't know what to do here, say N. 343 344config X86_MPPARSE 345 bool "Enable MPS table" if ACPI || SFI 346 default y 347 depends on X86_LOCAL_APIC 348 ---help--- 349 For old smp systems that do not have proper acpi support. Newer systems 350 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 351 352config X86_BIGSMP 353 bool "Support for big SMP systems with more than 8 CPUs" 354 depends on X86_32 && SMP 355 ---help--- 356 This option is needed for the systems that have more than 8 CPUs 357 358config GOLDFISH 359 def_bool y 360 depends on X86_GOLDFISH 361 362if X86_32 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) 32 bit x86 platforms: 373 Goldfish (Android emulator) 374 AMD Elan 375 RDC R-321x SoC 376 SGI 320/540 (Visual Workstation) 377 STA2X11-based (e.g. Northville) 378 Moorestown MID devices 379 380 If you have one of these systems, or if you want to build a 381 generic distribution kernel, say Y here - otherwise say N. 382endif 383 384if X86_64 385config X86_EXTENDED_PLATFORM 386 bool "Support for extended (non-PC) x86 platforms" 387 default y 388 ---help--- 389 If you disable this option then the kernel will only support 390 standard PC platforms. (which covers the vast majority of 391 systems out there.) 392 393 If you enable this option then you'll be able to select support 394 for the following (non-PC) 64 bit x86 platforms: 395 Numascale NumaChip 396 ScaleMP vSMP 397 SGI Ultraviolet 398 399 If you have one of these systems, or if you want to build a 400 generic distribution kernel, say Y here - otherwise say N. 401endif 402# This is an alphabetically sorted list of 64 bit extended platforms 403# Please maintain the alphabetic order if and when there are additions 404config X86_NUMACHIP 405 bool "Numascale NumaChip" 406 depends on X86_64 407 depends on X86_EXTENDED_PLATFORM 408 depends on NUMA 409 depends on SMP 410 depends on X86_X2APIC 411 depends on PCI_MMCONFIG 412 ---help--- 413 Adds support for Numascale NumaChip large-SMP systems. Needed to 414 enable more than ~168 cores. 415 If you don't have one of these, you should say N here. 416 417config X86_VSMP 418 bool "ScaleMP vSMP" 419 select HYPERVISOR_GUEST 420 select PARAVIRT 421 depends on X86_64 && PCI 422 depends on X86_EXTENDED_PLATFORM 423 depends on SMP 424 ---help--- 425 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 426 supposed to run on these EM64T-based machines. Only choose this option 427 if you have one of these machines. 428 429config X86_UV 430 bool "SGI Ultraviolet" 431 depends on X86_64 432 depends on X86_EXTENDED_PLATFORM 433 depends on NUMA 434 depends on X86_X2APIC 435 ---help--- 436 This option is needed in order to support SGI Ultraviolet systems. 437 If you don't have one of these, you should say N here. 438 439# Following is an alphabetically sorted list of 32 bit extended platforms 440# Please maintain the alphabetic order if and when there are additions 441 442config X86_GOLDFISH 443 bool "Goldfish (Virtual Platform)" 444 depends on X86_EXTENDED_PLATFORM 445 ---help--- 446 Enable support for the Goldfish virtual platform used primarily 447 for Android development. Unless you are building for the Android 448 Goldfish emulator say N here. 449 450config X86_INTEL_CE 451 bool "CE4100 TV platform" 452 depends on PCI 453 depends on PCI_GODIRECT 454 depends on X86_IO_APIC 455 depends on X86_32 456 depends on X86_EXTENDED_PLATFORM 457 select X86_REBOOTFIXUPS 458 select OF 459 select OF_EARLY_FLATTREE 460 select IRQ_DOMAIN 461 ---help--- 462 Select for the Intel CE media processor (CE4100) SOC. 463 This option compiles in support for the CE4100 SOC for settop 464 boxes and media devices. 465 466config X86_INTEL_MID 467 bool "Intel MID platform support" 468 depends on X86_32 469 depends on X86_EXTENDED_PLATFORM 470 depends on X86_PLATFORM_DEVICES 471 depends on PCI 472 depends on PCI_GOANY 473 depends on X86_IO_APIC 474 select SFI 475 select I2C 476 select DW_APB_TIMER 477 select APB_TIMER 478 select INTEL_SCU_IPC 479 select MFD_INTEL_MSIC 480 ---help--- 481 Select to build a kernel capable of supporting Intel MID (Mobile 482 Internet Device) platform systems which do not have the PCI legacy 483 interfaces. If you are building for a PC class system say N here. 484 485 Intel MID platforms are based on an Intel processor and chipset which 486 consume less power than most of the x86 derivatives. 487 488config X86_INTEL_LPSS 489 bool "Intel Low Power Subsystem Support" 490 depends on ACPI 491 select COMMON_CLK 492 select PINCTRL 493 ---help--- 494 Select to build support for Intel Low Power Subsystem such as 495 found on Intel Lynxpoint PCH. Selecting this option enables 496 things like clock tree (common clock framework) and pincontrol 497 which are needed by the LPSS peripheral drivers. 498 499config IOSF_MBI 500 tristate "Intel SoC IOSF Sideband support for SoC platforms" 501 depends on PCI 502 ---help--- 503 This option enables sideband register access support for Intel SoC 504 platforms. On these platforms the IOSF sideband is used in lieu of 505 MSR's for some register accesses, mostly but not limited to thermal 506 and power. Drivers may query the availability of this device to 507 determine if they need the sideband in order to work on these 508 platforms. The sideband is available on the following SoC products. 509 This list is not meant to be exclusive. 510 - BayTrail 511 - Braswell 512 - Quark 513 514 You should say Y if you are running a kernel on one of these SoC's. 515 516config IOSF_MBI_DEBUG 517 bool "Enable IOSF sideband access through debugfs" 518 depends on IOSF_MBI && DEBUG_FS 519 ---help--- 520 Select this option to expose the IOSF sideband access registers (MCR, 521 MDR, MCRX) through debugfs to write and read register information from 522 different units on the SoC. This is most useful for obtaining device 523 state information for debug and analysis. As this is a general access 524 mechanism, users of this option would have specific knowledge of the 525 device they want to access. 526 527 If you don't require the option or are in doubt, say N. 528 529config X86_RDC321X 530 bool "RDC R-321x SoC" 531 depends on X86_32 532 depends on X86_EXTENDED_PLATFORM 533 select M486 534 select X86_REBOOTFIXUPS 535 ---help--- 536 This option is needed for RDC R-321x system-on-chip, also known 537 as R-8610-(G). 538 If you don't have one of these chips, you should say N here. 539 540config X86_32_NON_STANDARD 541 bool "Support non-standard 32-bit SMP architectures" 542 depends on X86_32 && SMP 543 depends on X86_EXTENDED_PLATFORM 544 ---help--- 545 This option compiles in the bigsmp and STA2X11 default 546 subarchitectures. It is intended for a generic binary 547 kernel. If you select them all, kernel will probe it one by 548 one and will fallback to default. 549 550# Alphabetically sorted list of Non standard 32 bit platforms 551 552config X86_SUPPORTS_MEMORY_FAILURE 553 def_bool y 554 # MCE code calls memory_failure(): 555 depends on X86_MCE 556 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 557 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 558 depends on X86_64 || !SPARSEMEM 559 select ARCH_SUPPORTS_MEMORY_FAILURE 560 561config STA2X11 562 bool "STA2X11 Companion Chip Support" 563 depends on X86_32_NON_STANDARD && PCI 564 select X86_DEV_DMA_OPS 565 select X86_DMA_REMAP 566 select SWIOTLB 567 select MFD_STA2X11 568 select ARCH_REQUIRE_GPIOLIB 569 default n 570 ---help--- 571 This adds support for boards based on the STA2X11 IO-Hub, 572 a.k.a. "ConneXt". The chip is used in place of the standard 573 PC chipset, so all "standard" peripherals are missing. If this 574 option is selected the kernel will still be able to boot on 575 standard PC machines. 576 577config X86_32_IRIS 578 tristate "Eurobraille/Iris poweroff module" 579 depends on X86_32 580 ---help--- 581 The Iris machines from EuroBraille do not have APM or ACPI support 582 to shut themselves down properly. A special I/O sequence is 583 needed to do so, which is what this module does at 584 kernel shutdown. 585 586 This is only for Iris machines from EuroBraille. 587 588 If unused, say N. 589 590config SCHED_OMIT_FRAME_POINTER 591 def_bool y 592 prompt "Single-depth WCHAN output" 593 depends on X86 594 ---help--- 595 Calculate simpler /proc/<PID>/wchan values. If this option 596 is disabled then wchan values will recurse back to the 597 caller function. This provides more accurate wchan values, 598 at the expense of slightly more scheduling overhead. 599 600 If in doubt, say "Y". 601 602menuconfig HYPERVISOR_GUEST 603 bool "Linux guest support" 604 ---help--- 605 Say Y here to enable options for running Linux under various hyper- 606 visors. This option enables basic hypervisor detection and platform 607 setup. 608 609 If you say N, all options in this submenu will be skipped and 610 disabled, and Linux guest support won't be built in. 611 612if HYPERVISOR_GUEST 613 614config PARAVIRT 615 bool "Enable paravirtualization code" 616 ---help--- 617 This changes the kernel so it can modify itself when it is run 618 under a hypervisor, potentially improving performance significantly 619 over full virtualization. However, when run without a hypervisor 620 the kernel is theoretically slower and slightly larger. 621 622config PARAVIRT_DEBUG 623 bool "paravirt-ops debugging" 624 depends on PARAVIRT && DEBUG_KERNEL 625 ---help--- 626 Enable to debug paravirt_ops internals. Specifically, BUG if 627 a paravirt_op is missing when it is called. 628 629config PARAVIRT_SPINLOCKS 630 bool "Paravirtualization layer for spinlocks" 631 depends on PARAVIRT && SMP 632 select UNINLINE_SPIN_UNLOCK 633 ---help--- 634 Paravirtualized spinlocks allow a pvops backend to replace the 635 spinlock implementation with something virtualization-friendly 636 (for example, block the virtual CPU rather than spinning). 637 638 It has a minimal impact on native kernels and gives a nice performance 639 benefit on paravirtualized KVM / Xen kernels. 640 641 If you are unsure how to answer this question, answer Y. 642 643source "arch/x86/xen/Kconfig" 644 645config KVM_GUEST 646 bool "KVM Guest support (including kvmclock)" 647 depends on PARAVIRT 648 select PARAVIRT_CLOCK 649 default y 650 ---help--- 651 This option enables various optimizations for running under the KVM 652 hypervisor. It includes a paravirtualized clock, so that instead 653 of relying on a PIT (or probably other) emulation by the 654 underlying device model, the host provides the guest with 655 timing infrastructure such as time of day, and system time 656 657config KVM_DEBUG_FS 658 bool "Enable debug information for KVM Guests in debugfs" 659 depends on KVM_GUEST && DEBUG_FS 660 default n 661 ---help--- 662 This option enables collection of various statistics for KVM guest. 663 Statistics are displayed in debugfs filesystem. Enabling this option 664 may incur significant overhead. 665 666source "arch/x86/lguest/Kconfig" 667 668config PARAVIRT_TIME_ACCOUNTING 669 bool "Paravirtual steal time accounting" 670 depends on PARAVIRT 671 default n 672 ---help--- 673 Select this option to enable fine granularity task steal time 674 accounting. Time spent executing other tasks in parallel with 675 the current vCPU is discounted from the vCPU power. To account for 676 that, there can be a small performance impact. 677 678 If in doubt, say N here. 679 680config PARAVIRT_CLOCK 681 bool 682 683endif #HYPERVISOR_GUEST 684 685config NO_BOOTMEM 686 def_bool y 687 688config MEMTEST 689 bool "Memtest" 690 ---help--- 691 This option adds a kernel parameter 'memtest', which allows memtest 692 to be set. 693 memtest=0, mean disabled; -- default 694 memtest=1, mean do 1 test pattern; 695 ... 696 memtest=4, mean do 4 test patterns. 697 If you are unsure how to answer this question, answer N. 698 699source "arch/x86/Kconfig.cpu" 700 701config HPET_TIMER 702 def_bool X86_64 703 prompt "HPET Timer Support" if X86_32 704 ---help--- 705 Use the IA-PC HPET (High Precision Event Timer) to manage 706 time in preference to the PIT and RTC, if a HPET is 707 present. 708 HPET is the next generation timer replacing legacy 8254s. 709 The HPET provides a stable time base on SMP 710 systems, unlike the TSC, but it is more expensive to access, 711 as it is off-chip. You can find the HPET spec at 712 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 713 714 You can safely choose Y here. However, HPET will only be 715 activated if the platform and the BIOS support this feature. 716 Otherwise the 8254 will be used for timing services. 717 718 Choose N to continue using the legacy 8254 timer. 719 720config HPET_EMULATE_RTC 721 def_bool y 722 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 723 724config APB_TIMER 725 def_bool y if X86_INTEL_MID 726 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 727 select DW_APB_TIMER 728 depends on X86_INTEL_MID && SFI 729 help 730 APB timer is the replacement for 8254, HPET on X86 MID platforms. 731 The APBT provides a stable time base on SMP 732 systems, unlike the TSC, but it is more expensive to access, 733 as it is off-chip. APB timers are always running regardless of CPU 734 C states, they are used as per CPU clockevent device when possible. 735 736# Mark as expert because too many people got it wrong. 737# The code disables itself when not needed. 738config DMI 739 default y 740 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 741 bool "Enable DMI scanning" if EXPERT 742 ---help--- 743 Enabled scanning of DMI to identify machine quirks. Say Y 744 here unless you have verified that your setup is not 745 affected by entries in the DMI blacklist. Required by PNP 746 BIOS code. 747 748config GART_IOMMU 749 bool "Old AMD GART IOMMU support" 750 select SWIOTLB 751 depends on X86_64 && PCI && AMD_NB 752 ---help--- 753 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 754 GART based hardware IOMMUs. 755 756 The GART supports full DMA access for devices with 32-bit access 757 limitations, on systems with more than 3 GB. This is usually needed 758 for USB, sound, many IDE/SATA chipsets and some other devices. 759 760 Newer systems typically have a modern AMD IOMMU, supported via 761 the CONFIG_AMD_IOMMU=y config option. 762 763 In normal configurations this driver is only active when needed: 764 there's more than 3 GB of memory and the system contains a 765 32-bit limited device. 766 767 If unsure, say Y. 768 769config CALGARY_IOMMU 770 bool "IBM Calgary IOMMU support" 771 select SWIOTLB 772 depends on X86_64 && PCI 773 ---help--- 774 Support for hardware IOMMUs in IBM's xSeries x366 and x460 775 systems. Needed to run systems with more than 3GB of memory 776 properly with 32-bit PCI devices that do not support DAC 777 (Double Address Cycle). Calgary also supports bus level 778 isolation, where all DMAs pass through the IOMMU. This 779 prevents them from going anywhere except their intended 780 destination. This catches hard-to-find kernel bugs and 781 mis-behaving drivers and devices that do not use the DMA-API 782 properly to set up their DMA buffers. The IOMMU can be 783 turned off at boot time with the iommu=off parameter. 784 Normally the kernel will make the right choice by itself. 785 If unsure, say Y. 786 787config CALGARY_IOMMU_ENABLED_BY_DEFAULT 788 def_bool y 789 prompt "Should Calgary be enabled by default?" 790 depends on CALGARY_IOMMU 791 ---help--- 792 Should Calgary be enabled by default? if you choose 'y', Calgary 793 will be used (if it exists). If you choose 'n', Calgary will not be 794 used even if it exists. If you choose 'n' and would like to use 795 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 796 If unsure, say Y. 797 798# need this always selected by IOMMU for the VIA workaround 799config SWIOTLB 800 def_bool y if X86_64 801 ---help--- 802 Support for software bounce buffers used on x86-64 systems 803 which don't have a hardware IOMMU. Using this PCI devices 804 which can only access 32-bits of memory can be used on systems 805 with more than 3 GB of memory. 806 If unsure, say Y. 807 808config IOMMU_HELPER 809 def_bool y 810 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 811 812config MAXSMP 813 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 814 depends on X86_64 && SMP && DEBUG_KERNEL 815 select CPUMASK_OFFSTACK 816 ---help--- 817 Enable maximum number of CPUS and NUMA Nodes for this architecture. 818 If unsure, say N. 819 820config NR_CPUS 821 int "Maximum number of CPUs" if SMP && !MAXSMP 822 range 2 8 if SMP && X86_32 && !X86_BIGSMP 823 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 824 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 825 default "1" if !SMP 826 default "8192" if MAXSMP 827 default "32" if SMP && X86_BIGSMP 828 default "8" if SMP 829 ---help--- 830 This allows you to specify the maximum number of CPUs which this 831 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 832 supported value is 4096, otherwise the maximum value is 512. The 833 minimum value which makes sense is 2. 834 835 This is purely to save memory - each supported CPU adds 836 approximately eight kilobytes to the kernel image. 837 838config SCHED_SMT 839 bool "SMT (Hyperthreading) scheduler support" 840 depends on X86_HT 841 ---help--- 842 SMT scheduler support improves the CPU scheduler's decision making 843 when dealing with Intel Pentium 4 chips with HyperThreading at a 844 cost of slightly increased overhead in some places. If unsure say 845 N here. 846 847config SCHED_MC 848 def_bool y 849 prompt "Multi-core scheduler support" 850 depends on X86_HT 851 ---help--- 852 Multi-core scheduler support improves the CPU scheduler's decision 853 making when dealing with multi-core CPU chips at a cost of slightly 854 increased overhead in some places. If unsure say N here. 855 856source "kernel/Kconfig.preempt" 857 858config X86_UP_APIC 859 bool "Local APIC support on uniprocessors" 860 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 861 ---help--- 862 A local APIC (Advanced Programmable Interrupt Controller) is an 863 integrated interrupt controller in the CPU. If you have a single-CPU 864 system which has a processor with a local APIC, you can say Y here to 865 enable and use it. If you say Y here even though your machine doesn't 866 have a local APIC, then the kernel will still run with no slowdown at 867 all. The local APIC supports CPU-generated self-interrupts (timer, 868 performance counters), and the NMI watchdog which detects hard 869 lockups. 870 871config X86_UP_APIC_MSI 872 def_bool y 873 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI 874 875config X86_UP_IOAPIC 876 bool "IO-APIC support on uniprocessors" 877 depends on X86_UP_APIC 878 ---help--- 879 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 880 SMP-capable replacement for PC-style interrupt controllers. Most 881 SMP systems and many recent uniprocessor systems have one. 882 883 If you have a single-CPU system with an IO-APIC, you can say Y here 884 to use it. If you say Y here even though your machine doesn't have 885 an IO-APIC, then the kernel will still run with no slowdown at all. 886 887config X86_LOCAL_APIC 888 def_bool y 889 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 890 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ 891 892config X86_IO_APIC 893 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC 894 depends on X86_LOCAL_APIC 895 select IRQ_DOMAIN 896 897config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 898 bool "Reroute for broken boot IRQs" 899 depends on X86_IO_APIC 900 ---help--- 901 This option enables a workaround that fixes a source of 902 spurious interrupts. This is recommended when threaded 903 interrupt handling is used on systems where the generation of 904 superfluous "boot interrupts" cannot be disabled. 905 906 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 907 entry in the chipset's IO-APIC is masked (as, e.g. the RT 908 kernel does during interrupt handling). On chipsets where this 909 boot IRQ generation cannot be disabled, this workaround keeps 910 the original IRQ line masked so that only the equivalent "boot 911 IRQ" is delivered to the CPUs. The workaround also tells the 912 kernel to set up the IRQ handler on the boot IRQ line. In this 913 way only one interrupt is delivered to the kernel. Otherwise 914 the spurious second interrupt may cause the kernel to bring 915 down (vital) interrupt lines. 916 917 Only affects "broken" chipsets. Interrupt sharing may be 918 increased on these systems. 919 920config X86_MCE 921 bool "Machine Check / overheating reporting" 922 default y 923 ---help--- 924 Machine Check support allows the processor to notify the 925 kernel if it detects a problem (e.g. overheating, data corruption). 926 The action the kernel takes depends on the severity of the problem, 927 ranging from warning messages to halting the machine. 928 929config X86_MCE_INTEL 930 def_bool y 931 prompt "Intel MCE features" 932 depends on X86_MCE && X86_LOCAL_APIC 933 ---help--- 934 Additional support for intel specific MCE features such as 935 the thermal monitor. 936 937config X86_MCE_AMD 938 def_bool y 939 prompt "AMD MCE features" 940 depends on X86_MCE && X86_LOCAL_APIC 941 ---help--- 942 Additional support for AMD specific MCE features such as 943 the DRAM Error Threshold. 944 945config X86_ANCIENT_MCE 946 bool "Support for old Pentium 5 / WinChip machine checks" 947 depends on X86_32 && X86_MCE 948 ---help--- 949 Include support for machine check handling on old Pentium 5 or WinChip 950 systems. These typically need to be enabled explicitly on the command 951 line. 952 953config X86_MCE_THRESHOLD 954 depends on X86_MCE_AMD || X86_MCE_INTEL 955 def_bool y 956 957config X86_MCE_INJECT 958 depends on X86_MCE 959 tristate "Machine check injector support" 960 ---help--- 961 Provide support for injecting machine checks for testing purposes. 962 If you don't know what a machine check is and you don't do kernel 963 QA it is safe to say n. 964 965config X86_THERMAL_VECTOR 966 def_bool y 967 depends on X86_MCE_INTEL 968 969config VM86 970 bool "Enable VM86 support" if EXPERT 971 default y 972 depends on X86_32 973 ---help--- 974 This option is required by programs like DOSEMU to run 975 16-bit real mode legacy code on x86 processors. It also may 976 be needed by software like XFree86 to initialize some video 977 cards via BIOS. Disabling this option saves about 6K. 978 979config X86_16BIT 980 bool "Enable support for 16-bit segments" if EXPERT 981 default y 982 ---help--- 983 This option is required by programs like Wine to run 16-bit 984 protected mode legacy code on x86 processors. Disabling 985 this option saves about 300 bytes on i386, or around 6K text 986 plus 16K runtime memory on x86-64, 987 988config X86_ESPFIX32 989 def_bool y 990 depends on X86_16BIT && X86_32 991 992config X86_ESPFIX64 993 def_bool y 994 depends on X86_16BIT && X86_64 995 996config X86_VSYSCALL_EMULATION 997 bool "Enable vsyscall emulation" if EXPERT 998 default y 999 depends on X86_64 1000 ---help--- 1001 This enables emulation of the legacy vsyscall page. Disabling 1002 it is roughly equivalent to booting with vsyscall=none, except 1003 that it will also disable the helpful warning if a program 1004 tries to use a vsyscall. With this option set to N, offending 1005 programs will just segfault, citing addresses of the form 1006 0xffffffffff600?00. 1007 1008 This option is required by many programs built before 2013, and 1009 care should be used even with newer programs if set to N. 1010 1011 Disabling this option saves about 7K of kernel size and 1012 possibly 4K of additional runtime pagetable memory. 1013 1014config TOSHIBA 1015 tristate "Toshiba Laptop support" 1016 depends on X86_32 1017 ---help--- 1018 This adds a driver to safely access the System Management Mode of 1019 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1020 not work on models with a Phoenix BIOS. The System Management Mode 1021 is used to set the BIOS and power saving options on Toshiba portables. 1022 1023 For information on utilities to make use of this driver see the 1024 Toshiba Linux utilities web site at: 1025 <http://www.buzzard.org.uk/toshiba/>. 1026 1027 Say Y if you intend to run this kernel on a Toshiba portable. 1028 Say N otherwise. 1029 1030config I8K 1031 tristate "Dell laptop support" 1032 select HWMON 1033 ---help--- 1034 This adds a driver to safely access the System Management Mode 1035 of the CPU on the Dell Inspiron 8000. The System Management Mode 1036 is used to read cpu temperature and cooling fan status and to 1037 control the fans on the I8K portables. 1038 1039 This driver has been tested only on the Inspiron 8000 but it may 1040 also work with other Dell laptops. You can force loading on other 1041 models by passing the parameter `force=1' to the module. Use at 1042 your own risk. 1043 1044 For information on utilities to make use of this driver see the 1045 I8K Linux utilities web site at: 1046 <http://people.debian.org/~dz/i8k/> 1047 1048 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1049 Say N otherwise. 1050 1051config X86_REBOOTFIXUPS 1052 bool "Enable X86 board specific fixups for reboot" 1053 depends on X86_32 1054 ---help--- 1055 This enables chipset and/or board specific fixups to be done 1056 in order to get reboot to work correctly. This is only needed on 1057 some combinations of hardware and BIOS. The symptom, for which 1058 this config is intended, is when reboot ends with a stalled/hung 1059 system. 1060 1061 Currently, the only fixup is for the Geode machines using 1062 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1063 1064 Say Y if you want to enable the fixup. Currently, it's safe to 1065 enable this option even if you don't need it. 1066 Say N otherwise. 1067 1068config MICROCODE 1069 tristate "CPU microcode loading support" 1070 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1071 select FW_LOADER 1072 ---help--- 1073 1074 If you say Y here, you will be able to update the microcode on 1075 certain Intel and AMD processors. The Intel support is for the 1076 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1077 Xeon etc. The AMD support is for families 0x10 and later. You will 1078 obviously need the actual microcode binary data itself which is not 1079 shipped with the Linux kernel. 1080 1081 This option selects the general module only, you need to select 1082 at least one vendor specific module as well. 1083 1084 To compile this driver as a module, choose M here: the module 1085 will be called microcode. 1086 1087config MICROCODE_INTEL 1088 bool "Intel microcode loading support" 1089 depends on MICROCODE 1090 default MICROCODE 1091 select FW_LOADER 1092 ---help--- 1093 This options enables microcode patch loading support for Intel 1094 processors. 1095 1096 For the current Intel microcode data package go to 1097 <https://downloadcenter.intel.com> and search for 1098 'Linux Processor Microcode Data File'. 1099 1100config MICROCODE_AMD 1101 bool "AMD microcode loading support" 1102 depends on MICROCODE 1103 select FW_LOADER 1104 ---help--- 1105 If you select this option, microcode patch loading support for AMD 1106 processors will be enabled. 1107 1108config MICROCODE_OLD_INTERFACE 1109 def_bool y 1110 depends on MICROCODE 1111 1112config MICROCODE_INTEL_EARLY 1113 def_bool n 1114 1115config MICROCODE_AMD_EARLY 1116 def_bool n 1117 1118config MICROCODE_EARLY 1119 bool "Early load microcode" 1120 depends on MICROCODE=y && BLK_DEV_INITRD 1121 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1122 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1123 default y 1124 help 1125 This option provides functionality to read additional microcode data 1126 at the beginning of initrd image. The data tells kernel to load 1127 microcode to CPU's as early as possible. No functional change if no 1128 microcode data is glued to the initrd, therefore it's safe to say Y. 1129 1130config X86_MSR 1131 tristate "/dev/cpu/*/msr - Model-specific register support" 1132 ---help--- 1133 This device gives privileged processes access to the x86 1134 Model-Specific Registers (MSRs). It is a character device with 1135 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1136 MSR accesses are directed to a specific CPU on multi-processor 1137 systems. 1138 1139config X86_CPUID 1140 tristate "/dev/cpu/*/cpuid - CPU information support" 1141 ---help--- 1142 This device gives processes access to the x86 CPUID instruction to 1143 be executed on a specific processor. It is a character device 1144 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1145 /dev/cpu/31/cpuid. 1146 1147choice 1148 prompt "High Memory Support" 1149 default HIGHMEM4G 1150 depends on X86_32 1151 1152config NOHIGHMEM 1153 bool "off" 1154 ---help--- 1155 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1156 However, the address space of 32-bit x86 processors is only 4 1157 Gigabytes large. That means that, if you have a large amount of 1158 physical memory, not all of it can be "permanently mapped" by the 1159 kernel. The physical memory that's not permanently mapped is called 1160 "high memory". 1161 1162 If you are compiling a kernel which will never run on a machine with 1163 more than 1 Gigabyte total physical RAM, answer "off" here (default 1164 choice and suitable for most users). This will result in a "3GB/1GB" 1165 split: 3GB are mapped so that each process sees a 3GB virtual memory 1166 space and the remaining part of the 4GB virtual memory space is used 1167 by the kernel to permanently map as much physical memory as 1168 possible. 1169 1170 If the machine has between 1 and 4 Gigabytes physical RAM, then 1171 answer "4GB" here. 1172 1173 If more than 4 Gigabytes is used then answer "64GB" here. This 1174 selection turns Intel PAE (Physical Address Extension) mode on. 1175 PAE implements 3-level paging on IA32 processors. PAE is fully 1176 supported by Linux, PAE mode is implemented on all recent Intel 1177 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1178 then the kernel will not boot on CPUs that don't support PAE! 1179 1180 The actual amount of total physical memory will either be 1181 auto detected or can be forced by using a kernel command line option 1182 such as "mem=256M". (Try "man bootparam" or see the documentation of 1183 your boot loader (lilo or loadlin) about how to pass options to the 1184 kernel at boot time.) 1185 1186 If unsure, say "off". 1187 1188config HIGHMEM4G 1189 bool "4GB" 1190 ---help--- 1191 Select this if you have a 32-bit processor and between 1 and 4 1192 gigabytes of physical RAM. 1193 1194config HIGHMEM64G 1195 bool "64GB" 1196 depends on !M486 1197 select X86_PAE 1198 ---help--- 1199 Select this if you have a 32-bit processor and more than 4 1200 gigabytes of physical RAM. 1201 1202endchoice 1203 1204choice 1205 prompt "Memory split" if EXPERT 1206 default VMSPLIT_3G 1207 depends on X86_32 1208 ---help--- 1209 Select the desired split between kernel and user memory. 1210 1211 If the address range available to the kernel is less than the 1212 physical memory installed, the remaining memory will be available 1213 as "high memory". Accessing high memory is a little more costly 1214 than low memory, as it needs to be mapped into the kernel first. 1215 Note that increasing the kernel address space limits the range 1216 available to user programs, making the address space there 1217 tighter. Selecting anything other than the default 3G/1G split 1218 will also likely make your kernel incompatible with binary-only 1219 kernel modules. 1220 1221 If you are not absolutely sure what you are doing, leave this 1222 option alone! 1223 1224 config VMSPLIT_3G 1225 bool "3G/1G user/kernel split" 1226 config VMSPLIT_3G_OPT 1227 depends on !X86_PAE 1228 bool "3G/1G user/kernel split (for full 1G low memory)" 1229 config VMSPLIT_2G 1230 bool "2G/2G user/kernel split" 1231 config VMSPLIT_2G_OPT 1232 depends on !X86_PAE 1233 bool "2G/2G user/kernel split (for full 2G low memory)" 1234 config VMSPLIT_1G 1235 bool "1G/3G user/kernel split" 1236endchoice 1237 1238config PAGE_OFFSET 1239 hex 1240 default 0xB0000000 if VMSPLIT_3G_OPT 1241 default 0x80000000 if VMSPLIT_2G 1242 default 0x78000000 if VMSPLIT_2G_OPT 1243 default 0x40000000 if VMSPLIT_1G 1244 default 0xC0000000 1245 depends on X86_32 1246 1247config HIGHMEM 1248 def_bool y 1249 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1250 1251config X86_PAE 1252 bool "PAE (Physical Address Extension) Support" 1253 depends on X86_32 && !HIGHMEM4G 1254 ---help--- 1255 PAE is required for NX support, and furthermore enables 1256 larger swapspace support for non-overcommit purposes. It 1257 has the cost of more pagetable lookup overhead, and also 1258 consumes more pagetable space per process. 1259 1260config ARCH_PHYS_ADDR_T_64BIT 1261 def_bool y 1262 depends on X86_64 || X86_PAE 1263 1264config ARCH_DMA_ADDR_T_64BIT 1265 def_bool y 1266 depends on X86_64 || HIGHMEM64G 1267 1268config DIRECT_GBPAGES 1269 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1270 default y 1271 depends on X86_64 1272 ---help--- 1273 Allow the kernel linear mapping to use 1GB pages on CPUs that 1274 support it. This can improve the kernel's performance a tiny bit by 1275 reducing TLB pressure. If in doubt, say "Y". 1276 1277# Common NUMA Features 1278config NUMA 1279 bool "Numa Memory Allocation and Scheduler Support" 1280 depends on SMP 1281 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1282 default y if X86_BIGSMP 1283 ---help--- 1284 Enable NUMA (Non Uniform Memory Access) support. 1285 1286 The kernel will try to allocate memory used by a CPU on the 1287 local memory controller of the CPU and add some more 1288 NUMA awareness to the kernel. 1289 1290 For 64-bit this is recommended if the system is Intel Core i7 1291 (or later), AMD Opteron, or EM64T NUMA. 1292 1293 For 32-bit this is only needed if you boot a 32-bit 1294 kernel on a 64-bit NUMA platform. 1295 1296 Otherwise, you should say N. 1297 1298config AMD_NUMA 1299 def_bool y 1300 prompt "Old style AMD Opteron NUMA detection" 1301 depends on X86_64 && NUMA && PCI 1302 ---help--- 1303 Enable AMD NUMA node topology detection. You should say Y here if 1304 you have a multi processor AMD system. This uses an old method to 1305 read the NUMA configuration directly from the builtin Northbridge 1306 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1307 which also takes priority if both are compiled in. 1308 1309config X86_64_ACPI_NUMA 1310 def_bool y 1311 prompt "ACPI NUMA detection" 1312 depends on X86_64 && NUMA && ACPI && PCI 1313 select ACPI_NUMA 1314 ---help--- 1315 Enable ACPI SRAT based node topology detection. 1316 1317# Some NUMA nodes have memory ranges that span 1318# other nodes. Even though a pfn is valid and 1319# between a node's start and end pfns, it may not 1320# reside on that node. See memmap_init_zone() 1321# for details. 1322config NODES_SPAN_OTHER_NODES 1323 def_bool y 1324 depends on X86_64_ACPI_NUMA 1325 1326config NUMA_EMU 1327 bool "NUMA emulation" 1328 depends on NUMA 1329 ---help--- 1330 Enable NUMA emulation. A flat machine will be split 1331 into virtual nodes when booted with "numa=fake=N", where N is the 1332 number of nodes. This is only useful for debugging. 1333 1334config NODES_SHIFT 1335 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1336 range 1 10 1337 default "10" if MAXSMP 1338 default "6" if X86_64 1339 default "3" 1340 depends on NEED_MULTIPLE_NODES 1341 ---help--- 1342 Specify the maximum number of NUMA Nodes available on the target 1343 system. Increases memory reserved to accommodate various tables. 1344 1345config ARCH_HAVE_MEMORY_PRESENT 1346 def_bool y 1347 depends on X86_32 && DISCONTIGMEM 1348 1349config NEED_NODE_MEMMAP_SIZE 1350 def_bool y 1351 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1352 1353config ARCH_FLATMEM_ENABLE 1354 def_bool y 1355 depends on X86_32 && !NUMA 1356 1357config ARCH_DISCONTIGMEM_ENABLE 1358 def_bool y 1359 depends on NUMA && X86_32 1360 1361config ARCH_DISCONTIGMEM_DEFAULT 1362 def_bool y 1363 depends on NUMA && X86_32 1364 1365config ARCH_SPARSEMEM_ENABLE 1366 def_bool y 1367 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1368 select SPARSEMEM_STATIC if X86_32 1369 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1370 1371config ARCH_SPARSEMEM_DEFAULT 1372 def_bool y 1373 depends on X86_64 1374 1375config ARCH_SELECT_MEMORY_MODEL 1376 def_bool y 1377 depends on ARCH_SPARSEMEM_ENABLE 1378 1379config ARCH_MEMORY_PROBE 1380 bool "Enable sysfs memory/probe interface" 1381 depends on X86_64 && MEMORY_HOTPLUG 1382 help 1383 This option enables a sysfs memory/probe interface for testing. 1384 See Documentation/memory-hotplug.txt for more information. 1385 If you are unsure how to answer this question, answer N. 1386 1387config ARCH_PROC_KCORE_TEXT 1388 def_bool y 1389 depends on X86_64 && PROC_KCORE 1390 1391config ILLEGAL_POINTER_VALUE 1392 hex 1393 default 0 if X86_32 1394 default 0xdead000000000000 if X86_64 1395 1396source "mm/Kconfig" 1397 1398config HIGHPTE 1399 bool "Allocate 3rd-level pagetables from highmem" 1400 depends on HIGHMEM 1401 ---help--- 1402 The VM uses one page table entry for each page of physical memory. 1403 For systems with a lot of RAM, this can be wasteful of precious 1404 low memory. Setting this option will put user-space page table 1405 entries in high memory. 1406 1407config X86_CHECK_BIOS_CORRUPTION 1408 bool "Check for low memory corruption" 1409 ---help--- 1410 Periodically check for memory corruption in low memory, which 1411 is suspected to be caused by BIOS. Even when enabled in the 1412 configuration, it is disabled at runtime. Enable it by 1413 setting "memory_corruption_check=1" on the kernel command 1414 line. By default it scans the low 64k of memory every 60 1415 seconds; see the memory_corruption_check_size and 1416 memory_corruption_check_period parameters in 1417 Documentation/kernel-parameters.txt to adjust this. 1418 1419 When enabled with the default parameters, this option has 1420 almost no overhead, as it reserves a relatively small amount 1421 of memory and scans it infrequently. It both detects corruption 1422 and prevents it from affecting the running system. 1423 1424 It is, however, intended as a diagnostic tool; if repeatable 1425 BIOS-originated corruption always affects the same memory, 1426 you can use memmap= to prevent the kernel from using that 1427 memory. 1428 1429config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1430 bool "Set the default setting of memory_corruption_check" 1431 depends on X86_CHECK_BIOS_CORRUPTION 1432 default y 1433 ---help--- 1434 Set whether the default state of memory_corruption_check is 1435 on or off. 1436 1437config X86_RESERVE_LOW 1438 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1439 default 64 1440 range 4 640 1441 ---help--- 1442 Specify the amount of low memory to reserve for the BIOS. 1443 1444 The first page contains BIOS data structures that the kernel 1445 must not use, so that page must always be reserved. 1446 1447 By default we reserve the first 64K of physical RAM, as a 1448 number of BIOSes are known to corrupt that memory range 1449 during events such as suspend/resume or monitor cable 1450 insertion, so it must not be used by the kernel. 1451 1452 You can set this to 4 if you are absolutely sure that you 1453 trust the BIOS to get all its memory reservations and usages 1454 right. If you know your BIOS have problems beyond the 1455 default 64K area, you can set this to 640 to avoid using the 1456 entire low memory range. 1457 1458 If you have doubts about the BIOS (e.g. suspend/resume does 1459 not work or there's kernel crashes after certain hardware 1460 hotplug events) then you might want to enable 1461 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1462 typical corruption patterns. 1463 1464 Leave this to the default value of 64 if you are unsure. 1465 1466config MATH_EMULATION 1467 bool 1468 prompt "Math emulation" if X86_32 1469 ---help--- 1470 Linux can emulate a math coprocessor (used for floating point 1471 operations) if you don't have one. 486DX and Pentium processors have 1472 a math coprocessor built in, 486SX and 386 do not, unless you added 1473 a 487DX or 387, respectively. (The messages during boot time can 1474 give you some hints here ["man dmesg"].) Everyone needs either a 1475 coprocessor or this emulation. 1476 1477 If you don't have a math coprocessor, you need to say Y here; if you 1478 say Y here even though you have a coprocessor, the coprocessor will 1479 be used nevertheless. (This behavior can be changed with the kernel 1480 command line option "no387", which comes handy if your coprocessor 1481 is broken. Try "man bootparam" or see the documentation of your boot 1482 loader (lilo or loadlin) about how to pass options to the kernel at 1483 boot time.) This means that it is a good idea to say Y here if you 1484 intend to use this kernel on different machines. 1485 1486 More information about the internals of the Linux math coprocessor 1487 emulation can be found in <file:arch/x86/math-emu/README>. 1488 1489 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1490 kernel, it won't hurt. 1491 1492config MTRR 1493 def_bool y 1494 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1495 ---help--- 1496 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1497 the Memory Type Range Registers (MTRRs) may be used to control 1498 processor access to memory ranges. This is most useful if you have 1499 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1500 allows bus write transfers to be combined into a larger transfer 1501 before bursting over the PCI/AGP bus. This can increase performance 1502 of image write operations 2.5 times or more. Saying Y here creates a 1503 /proc/mtrr file which may be used to manipulate your processor's 1504 MTRRs. Typically the X server should use this. 1505 1506 This code has a reasonably generic interface so that similar 1507 control registers on other processors can be easily supported 1508 as well: 1509 1510 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1511 Registers (ARRs) which provide a similar functionality to MTRRs. For 1512 these, the ARRs are used to emulate the MTRRs. 1513 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1514 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1515 write-combining. All of these processors are supported by this code 1516 and it makes sense to say Y here if you have one of them. 1517 1518 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1519 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1520 can lead to all sorts of problems, so it's good to say Y here. 1521 1522 You can safely say Y even if your machine doesn't have MTRRs, you'll 1523 just add about 9 KB to your kernel. 1524 1525 See <file:Documentation/x86/mtrr.txt> for more information. 1526 1527config MTRR_SANITIZER 1528 def_bool y 1529 prompt "MTRR cleanup support" 1530 depends on MTRR 1531 ---help--- 1532 Convert MTRR layout from continuous to discrete, so X drivers can 1533 add writeback entries. 1534 1535 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1536 The largest mtrr entry size for a continuous block can be set with 1537 mtrr_chunk_size. 1538 1539 If unsure, say Y. 1540 1541config MTRR_SANITIZER_ENABLE_DEFAULT 1542 int "MTRR cleanup enable value (0-1)" 1543 range 0 1 1544 default "0" 1545 depends on MTRR_SANITIZER 1546 ---help--- 1547 Enable mtrr cleanup default value 1548 1549config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1550 int "MTRR cleanup spare reg num (0-7)" 1551 range 0 7 1552 default "1" 1553 depends on MTRR_SANITIZER 1554 ---help--- 1555 mtrr cleanup spare entries default, it can be changed via 1556 mtrr_spare_reg_nr=N on the kernel command line. 1557 1558config X86_PAT 1559 def_bool y 1560 prompt "x86 PAT support" if EXPERT 1561 depends on MTRR 1562 ---help--- 1563 Use PAT attributes to setup page level cache control. 1564 1565 PATs are the modern equivalents of MTRRs and are much more 1566 flexible than MTRRs. 1567 1568 Say N here if you see bootup problems (boot crash, boot hang, 1569 spontaneous reboots) or a non-working video driver. 1570 1571 If unsure, say Y. 1572 1573config ARCH_USES_PG_UNCACHED 1574 def_bool y 1575 depends on X86_PAT 1576 1577config ARCH_RANDOM 1578 def_bool y 1579 prompt "x86 architectural random number generator" if EXPERT 1580 ---help--- 1581 Enable the x86 architectural RDRAND instruction 1582 (Intel Bull Mountain technology) to generate random numbers. 1583 If supported, this is a high bandwidth, cryptographically 1584 secure hardware random number generator. 1585 1586config X86_SMAP 1587 def_bool y 1588 prompt "Supervisor Mode Access Prevention" if EXPERT 1589 ---help--- 1590 Supervisor Mode Access Prevention (SMAP) is a security 1591 feature in newer Intel processors. There is a small 1592 performance cost if this enabled and turned on; there is 1593 also a small increase in the kernel size if this is enabled. 1594 1595 If unsure, say Y. 1596 1597config X86_INTEL_MPX 1598 prompt "Intel MPX (Memory Protection Extensions)" 1599 def_bool n 1600 depends on CPU_SUP_INTEL 1601 ---help--- 1602 MPX provides hardware features that can be used in 1603 conjunction with compiler-instrumented code to check 1604 memory references. It is designed to detect buffer 1605 overflow or underflow bugs. 1606 1607 This option enables running applications which are 1608 instrumented or otherwise use MPX. It does not use MPX 1609 itself inside the kernel or to protect the kernel 1610 against bad memory references. 1611 1612 Enabling this option will make the kernel larger: 1613 ~8k of kernel text and 36 bytes of data on a 64-bit 1614 defconfig. It adds a long to the 'mm_struct' which 1615 will increase the kernel memory overhead of each 1616 process and adds some branches to paths used during 1617 exec() and munmap(). 1618 1619 For details, see Documentation/x86/intel_mpx.txt 1620 1621 If unsure, say N. 1622 1623config EFI 1624 bool "EFI runtime service support" 1625 depends on ACPI 1626 select UCS2_STRING 1627 select EFI_RUNTIME_WRAPPERS 1628 ---help--- 1629 This enables the kernel to use EFI runtime services that are 1630 available (such as the EFI variable services). 1631 1632 This option is only useful on systems that have EFI firmware. 1633 In addition, you should use the latest ELILO loader available 1634 at <http://elilo.sourceforge.net> in order to take advantage 1635 of EFI runtime services. However, even with this option, the 1636 resultant kernel should continue to boot on existing non-EFI 1637 platforms. 1638 1639config EFI_STUB 1640 bool "EFI stub support" 1641 depends on EFI && !X86_USE_3DNOW 1642 select RELOCATABLE 1643 ---help--- 1644 This kernel feature allows a bzImage to be loaded directly 1645 by EFI firmware without the use of a bootloader. 1646 1647 See Documentation/efi-stub.txt for more information. 1648 1649config EFI_MIXED 1650 bool "EFI mixed-mode support" 1651 depends on EFI_STUB && X86_64 1652 ---help--- 1653 Enabling this feature allows a 64-bit kernel to be booted 1654 on a 32-bit firmware, provided that your CPU supports 64-bit 1655 mode. 1656 1657 Note that it is not possible to boot a mixed-mode enabled 1658 kernel via the EFI boot stub - a bootloader that supports 1659 the EFI handover protocol must be used. 1660 1661 If unsure, say N. 1662 1663config SECCOMP 1664 def_bool y 1665 prompt "Enable seccomp to safely compute untrusted bytecode" 1666 ---help--- 1667 This kernel feature is useful for number crunching applications 1668 that may need to compute untrusted bytecode during their 1669 execution. By using pipes or other transports made available to 1670 the process as file descriptors supporting the read/write 1671 syscalls, it's possible to isolate those applications in 1672 their own address space using seccomp. Once seccomp is 1673 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1674 and the task is only allowed to execute a few safe syscalls 1675 defined by each seccomp mode. 1676 1677 If unsure, say Y. Only embedded should say N here. 1678 1679source kernel/Kconfig.hz 1680 1681config KEXEC 1682 bool "kexec system call" 1683 ---help--- 1684 kexec is a system call that implements the ability to shutdown your 1685 current kernel, and to start another kernel. It is like a reboot 1686 but it is independent of the system firmware. And like a reboot 1687 you can start any kernel with it, not just Linux. 1688 1689 The name comes from the similarity to the exec system call. 1690 1691 It is an ongoing process to be certain the hardware in a machine 1692 is properly shutdown, so do not be surprised if this code does not 1693 initially work for you. As of this writing the exact hardware 1694 interface is strongly in flux, so no good recommendation can be 1695 made. 1696 1697config KEXEC_FILE 1698 bool "kexec file based system call" 1699 select BUILD_BIN2C 1700 depends on KEXEC 1701 depends on X86_64 1702 depends on CRYPTO=y 1703 depends on CRYPTO_SHA256=y 1704 ---help--- 1705 This is new version of kexec system call. This system call is 1706 file based and takes file descriptors as system call argument 1707 for kernel and initramfs as opposed to list of segments as 1708 accepted by previous system call. 1709 1710config KEXEC_VERIFY_SIG 1711 bool "Verify kernel signature during kexec_file_load() syscall" 1712 depends on KEXEC_FILE 1713 ---help--- 1714 This option makes kernel signature verification mandatory for 1715 kexec_file_load() syscall. If kernel is signature can not be 1716 verified, kexec_file_load() will fail. 1717 1718 This option enforces signature verification at generic level. 1719 One needs to enable signature verification for type of kernel 1720 image being loaded to make sure it works. For example, enable 1721 bzImage signature verification option to be able to load and 1722 verify signatures of bzImage. Otherwise kernel loading will fail. 1723 1724config KEXEC_BZIMAGE_VERIFY_SIG 1725 bool "Enable bzImage signature verification support" 1726 depends on KEXEC_VERIFY_SIG 1727 depends on SIGNED_PE_FILE_VERIFICATION 1728 select SYSTEM_TRUSTED_KEYRING 1729 ---help--- 1730 Enable bzImage signature verification support. 1731 1732config CRASH_DUMP 1733 bool "kernel crash dumps" 1734 depends on X86_64 || (X86_32 && HIGHMEM) 1735 ---help--- 1736 Generate crash dump after being started by kexec. 1737 This should be normally only set in special crash dump kernels 1738 which are loaded in the main kernel with kexec-tools into 1739 a specially reserved region and then later executed after 1740 a crash by kdump/kexec. The crash dump kernel must be compiled 1741 to a memory address not used by the main kernel or BIOS using 1742 PHYSICAL_START, or it must be built as a relocatable image 1743 (CONFIG_RELOCATABLE=y). 1744 For more details see Documentation/kdump/kdump.txt 1745 1746config KEXEC_JUMP 1747 bool "kexec jump" 1748 depends on KEXEC && HIBERNATION 1749 ---help--- 1750 Jump between original kernel and kexeced kernel and invoke 1751 code in physical address mode via KEXEC 1752 1753config PHYSICAL_START 1754 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1755 default "0x1000000" 1756 ---help--- 1757 This gives the physical address where the kernel is loaded. 1758 1759 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1760 bzImage will decompress itself to above physical address and 1761 run from there. Otherwise, bzImage will run from the address where 1762 it has been loaded by the boot loader and will ignore above physical 1763 address. 1764 1765 In normal kdump cases one does not have to set/change this option 1766 as now bzImage can be compiled as a completely relocatable image 1767 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1768 address. This option is mainly useful for the folks who don't want 1769 to use a bzImage for capturing the crash dump and want to use a 1770 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1771 to be specifically compiled to run from a specific memory area 1772 (normally a reserved region) and this option comes handy. 1773 1774 So if you are using bzImage for capturing the crash dump, 1775 leave the value here unchanged to 0x1000000 and set 1776 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1777 for capturing the crash dump change this value to start of 1778 the reserved region. In other words, it can be set based on 1779 the "X" value as specified in the "crashkernel=YM@XM" 1780 command line boot parameter passed to the panic-ed 1781 kernel. Please take a look at Documentation/kdump/kdump.txt 1782 for more details about crash dumps. 1783 1784 Usage of bzImage for capturing the crash dump is recommended as 1785 one does not have to build two kernels. Same kernel can be used 1786 as production kernel and capture kernel. Above option should have 1787 gone away after relocatable bzImage support is introduced. But it 1788 is present because there are users out there who continue to use 1789 vmlinux for dump capture. This option should go away down the 1790 line. 1791 1792 Don't change this unless you know what you are doing. 1793 1794config RELOCATABLE 1795 bool "Build a relocatable kernel" 1796 default y 1797 ---help--- 1798 This builds a kernel image that retains relocation information 1799 so it can be loaded someplace besides the default 1MB. 1800 The relocations tend to make the kernel binary about 10% larger, 1801 but are discarded at runtime. 1802 1803 One use is for the kexec on panic case where the recovery kernel 1804 must live at a different physical address than the primary 1805 kernel. 1806 1807 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1808 it has been loaded at and the compile time physical address 1809 (CONFIG_PHYSICAL_START) is used as the minimum location. 1810 1811config RANDOMIZE_BASE 1812 bool "Randomize the address of the kernel image" 1813 depends on RELOCATABLE 1814 default n 1815 ---help--- 1816 Randomizes the physical and virtual address at which the 1817 kernel image is decompressed, as a security feature that 1818 deters exploit attempts relying on knowledge of the location 1819 of kernel internals. 1820 1821 Entropy is generated using the RDRAND instruction if it is 1822 supported. If RDTSC is supported, it is used as well. If 1823 neither RDRAND nor RDTSC are supported, then randomness is 1824 read from the i8254 timer. 1825 1826 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1827 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1828 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1829 minimum of 2MiB, only 10 bits of entropy is theoretically 1830 possible. At best, due to page table layouts, 64-bit can use 1831 9 bits of entropy and 32-bit uses 8 bits. 1832 1833 If unsure, say N. 1834 1835config RANDOMIZE_BASE_MAX_OFFSET 1836 hex "Maximum kASLR offset allowed" if EXPERT 1837 depends on RANDOMIZE_BASE 1838 range 0x0 0x20000000 if X86_32 1839 default "0x20000000" if X86_32 1840 range 0x0 0x40000000 if X86_64 1841 default "0x40000000" if X86_64 1842 ---help--- 1843 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1844 memory is used to determine the maximal offset in bytes that will 1845 be applied to the kernel when kernel Address Space Layout 1846 Randomization (kASLR) is active. This must be a multiple of 1847 PHYSICAL_ALIGN. 1848 1849 On 32-bit this is limited to 512MiB by page table layouts. The 1850 default is 512MiB. 1851 1852 On 64-bit this is limited by how the kernel fixmap page table is 1853 positioned, so this cannot be larger than 1GiB currently. Without 1854 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1855 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1856 modules area will shrink to compensate, up to the current maximum 1857 1GiB to 1GiB split. The default is 1GiB. 1858 1859 If unsure, leave at the default value. 1860 1861# Relocation on x86 needs some additional build support 1862config X86_NEED_RELOCS 1863 def_bool y 1864 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1865 1866config PHYSICAL_ALIGN 1867 hex "Alignment value to which kernel should be aligned" 1868 default "0x200000" 1869 range 0x2000 0x1000000 if X86_32 1870 range 0x200000 0x1000000 if X86_64 1871 ---help--- 1872 This value puts the alignment restrictions on physical address 1873 where kernel is loaded and run from. Kernel is compiled for an 1874 address which meets above alignment restriction. 1875 1876 If bootloader loads the kernel at a non-aligned address and 1877 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1878 address aligned to above value and run from there. 1879 1880 If bootloader loads the kernel at a non-aligned address and 1881 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1882 load address and decompress itself to the address it has been 1883 compiled for and run from there. The address for which kernel is 1884 compiled already meets above alignment restrictions. Hence the 1885 end result is that kernel runs from a physical address meeting 1886 above alignment restrictions. 1887 1888 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1889 this value must be a multiple of 0x200000. 1890 1891 Don't change this unless you know what you are doing. 1892 1893config HOTPLUG_CPU 1894 bool "Support for hot-pluggable CPUs" 1895 depends on SMP 1896 ---help--- 1897 Say Y here to allow turning CPUs off and on. CPUs can be 1898 controlled through /sys/devices/system/cpu. 1899 ( Note: power management support will enable this option 1900 automatically on SMP systems. ) 1901 Say N if you want to disable CPU hotplug. 1902 1903config BOOTPARAM_HOTPLUG_CPU0 1904 bool "Set default setting of cpu0_hotpluggable" 1905 default n 1906 depends on HOTPLUG_CPU 1907 ---help--- 1908 Set whether default state of cpu0_hotpluggable is on or off. 1909 1910 Say Y here to enable CPU0 hotplug by default. If this switch 1911 is turned on, there is no need to give cpu0_hotplug kernel 1912 parameter and the CPU0 hotplug feature is enabled by default. 1913 1914 Please note: there are two known CPU0 dependencies if you want 1915 to enable the CPU0 hotplug feature either by this switch or by 1916 cpu0_hotplug kernel parameter. 1917 1918 First, resume from hibernate or suspend always starts from CPU0. 1919 So hibernate and suspend are prevented if CPU0 is offline. 1920 1921 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1922 offline if any interrupt can not migrate out of CPU0. There may 1923 be other CPU0 dependencies. 1924 1925 Please make sure the dependencies are under your control before 1926 you enable this feature. 1927 1928 Say N if you don't want to enable CPU0 hotplug feature by default. 1929 You still can enable the CPU0 hotplug feature at boot by kernel 1930 parameter cpu0_hotplug. 1931 1932config DEBUG_HOTPLUG_CPU0 1933 def_bool n 1934 prompt "Debug CPU0 hotplug" 1935 depends on HOTPLUG_CPU 1936 ---help--- 1937 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1938 soon as possible and boots up userspace with CPU0 offlined. User 1939 can online CPU0 back after boot time. 1940 1941 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1942 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1943 compilation or giving cpu0_hotplug kernel parameter at boot. 1944 1945 If unsure, say N. 1946 1947config COMPAT_VDSO 1948 def_bool n 1949 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 1950 depends on X86_32 || IA32_EMULATION 1951 ---help--- 1952 Certain buggy versions of glibc will crash if they are 1953 presented with a 32-bit vDSO that is not mapped at the address 1954 indicated in its segment table. 1955 1956 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 1957 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 1958 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 1959 the only released version with the bug, but OpenSUSE 9 1960 contains a buggy "glibc 2.3.2". 1961 1962 The symptom of the bug is that everything crashes on startup, saying: 1963 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 1964 1965 Saying Y here changes the default value of the vdso32 boot 1966 option from 1 to 0, which turns off the 32-bit vDSO entirely. 1967 This works around the glibc bug but hurts performance. 1968 1969 If unsure, say N: if you are compiling your own kernel, you 1970 are unlikely to be using a buggy version of glibc. 1971 1972config CMDLINE_BOOL 1973 bool "Built-in kernel command line" 1974 ---help--- 1975 Allow for specifying boot arguments to the kernel at 1976 build time. On some systems (e.g. embedded ones), it is 1977 necessary or convenient to provide some or all of the 1978 kernel boot arguments with the kernel itself (that is, 1979 to not rely on the boot loader to provide them.) 1980 1981 To compile command line arguments into the kernel, 1982 set this option to 'Y', then fill in the 1983 the boot arguments in CONFIG_CMDLINE. 1984 1985 Systems with fully functional boot loaders (i.e. non-embedded) 1986 should leave this option set to 'N'. 1987 1988config CMDLINE 1989 string "Built-in kernel command string" 1990 depends on CMDLINE_BOOL 1991 default "" 1992 ---help--- 1993 Enter arguments here that should be compiled into the kernel 1994 image and used at boot time. If the boot loader provides a 1995 command line at boot time, it is appended to this string to 1996 form the full kernel command line, when the system boots. 1997 1998 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1999 change this behavior. 2000 2001 In most cases, the command line (whether built-in or provided 2002 by the boot loader) should specify the device for the root 2003 file system. 2004 2005config CMDLINE_OVERRIDE 2006 bool "Built-in command line overrides boot loader arguments" 2007 depends on CMDLINE_BOOL 2008 ---help--- 2009 Set this option to 'Y' to have the kernel ignore the boot loader 2010 command line, and use ONLY the built-in command line. 2011 2012 This is used to work around broken boot loaders. This should 2013 be set to 'N' under normal conditions. 2014 2015endmenu 2016 2017config ARCH_ENABLE_MEMORY_HOTPLUG 2018 def_bool y 2019 depends on X86_64 || (X86_32 && HIGHMEM) 2020 2021config ARCH_ENABLE_MEMORY_HOTREMOVE 2022 def_bool y 2023 depends on MEMORY_HOTPLUG 2024 2025config USE_PERCPU_NUMA_NODE_ID 2026 def_bool y 2027 depends on NUMA 2028 2029config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2030 def_bool y 2031 depends on X86_64 || X86_PAE 2032 2033config ARCH_ENABLE_HUGEPAGE_MIGRATION 2034 def_bool y 2035 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2036 2037menu "Power management and ACPI options" 2038 2039config ARCH_HIBERNATION_HEADER 2040 def_bool y 2041 depends on X86_64 && HIBERNATION 2042 2043source "kernel/power/Kconfig" 2044 2045source "drivers/acpi/Kconfig" 2046 2047source "drivers/sfi/Kconfig" 2048 2049config X86_APM_BOOT 2050 def_bool y 2051 depends on APM 2052 2053menuconfig APM 2054 tristate "APM (Advanced Power Management) BIOS support" 2055 depends on X86_32 && PM_SLEEP 2056 ---help--- 2057 APM is a BIOS specification for saving power using several different 2058 techniques. This is mostly useful for battery powered laptops with 2059 APM compliant BIOSes. If you say Y here, the system time will be 2060 reset after a RESUME operation, the /proc/apm device will provide 2061 battery status information, and user-space programs will receive 2062 notification of APM "events" (e.g. battery status change). 2063 2064 If you select "Y" here, you can disable actual use of the APM 2065 BIOS by passing the "apm=off" option to the kernel at boot time. 2066 2067 Note that the APM support is almost completely disabled for 2068 machines with more than one CPU. 2069 2070 In order to use APM, you will need supporting software. For location 2071 and more information, read <file:Documentation/power/apm-acpi.txt> 2072 and the Battery Powered Linux mini-HOWTO, available from 2073 <http://www.tldp.org/docs.html#howto>. 2074 2075 This driver does not spin down disk drives (see the hdparm(8) 2076 manpage ("man 8 hdparm") for that), and it doesn't turn off 2077 VESA-compliant "green" monitors. 2078 2079 This driver does not support the TI 4000M TravelMate and the ACER 2080 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2081 desktop machines also don't have compliant BIOSes, and this driver 2082 may cause those machines to panic during the boot phase. 2083 2084 Generally, if you don't have a battery in your machine, there isn't 2085 much point in using this driver and you should say N. If you get 2086 random kernel OOPSes or reboots that don't seem to be related to 2087 anything, try disabling/enabling this option (or disabling/enabling 2088 APM in your BIOS). 2089 2090 Some other things you should try when experiencing seemingly random, 2091 "weird" problems: 2092 2093 1) make sure that you have enough swap space and that it is 2094 enabled. 2095 2) pass the "no-hlt" option to the kernel 2096 3) switch on floating point emulation in the kernel and pass 2097 the "no387" option to the kernel 2098 4) pass the "floppy=nodma" option to the kernel 2099 5) pass the "mem=4M" option to the kernel (thereby disabling 2100 all but the first 4 MB of RAM) 2101 6) make sure that the CPU is not over clocked. 2102 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2103 8) disable the cache from your BIOS settings 2104 9) install a fan for the video card or exchange video RAM 2105 10) install a better fan for the CPU 2106 11) exchange RAM chips 2107 12) exchange the motherboard. 2108 2109 To compile this driver as a module, choose M here: the 2110 module will be called apm. 2111 2112if APM 2113 2114config APM_IGNORE_USER_SUSPEND 2115 bool "Ignore USER SUSPEND" 2116 ---help--- 2117 This option will ignore USER SUSPEND requests. On machines with a 2118 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2119 series notebooks, it is necessary to say Y because of a BIOS bug. 2120 2121config APM_DO_ENABLE 2122 bool "Enable PM at boot time" 2123 ---help--- 2124 Enable APM features at boot time. From page 36 of the APM BIOS 2125 specification: "When disabled, the APM BIOS does not automatically 2126 power manage devices, enter the Standby State, enter the Suspend 2127 State, or take power saving steps in response to CPU Idle calls." 2128 This driver will make CPU Idle calls when Linux is idle (unless this 2129 feature is turned off -- see "Do CPU IDLE calls", below). This 2130 should always save battery power, but more complicated APM features 2131 will be dependent on your BIOS implementation. You may need to turn 2132 this option off if your computer hangs at boot time when using APM 2133 support, or if it beeps continuously instead of suspending. Turn 2134 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2135 T400CDT. This is off by default since most machines do fine without 2136 this feature. 2137 2138config APM_CPU_IDLE 2139 depends on CPU_IDLE 2140 bool "Make CPU Idle calls when idle" 2141 ---help--- 2142 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2143 On some machines, this can activate improved power savings, such as 2144 a slowed CPU clock rate, when the machine is idle. These idle calls 2145 are made after the idle loop has run for some length of time (e.g., 2146 333 mS). On some machines, this will cause a hang at boot time or 2147 whenever the CPU becomes idle. (On machines with more than one CPU, 2148 this option does nothing.) 2149 2150config APM_DISPLAY_BLANK 2151 bool "Enable console blanking using APM" 2152 ---help--- 2153 Enable console blanking using the APM. Some laptops can use this to 2154 turn off the LCD backlight when the screen blanker of the Linux 2155 virtual console blanks the screen. Note that this is only used by 2156 the virtual console screen blanker, and won't turn off the backlight 2157 when using the X Window system. This also doesn't have anything to 2158 do with your VESA-compliant power-saving monitor. Further, this 2159 option doesn't work for all laptops -- it might not turn off your 2160 backlight at all, or it might print a lot of errors to the console, 2161 especially if you are using gpm. 2162 2163config APM_ALLOW_INTS 2164 bool "Allow interrupts during APM BIOS calls" 2165 ---help--- 2166 Normally we disable external interrupts while we are making calls to 2167 the APM BIOS as a measure to lessen the effects of a badly behaving 2168 BIOS implementation. The BIOS should reenable interrupts if it 2169 needs to. Unfortunately, some BIOSes do not -- especially those in 2170 many of the newer IBM Thinkpads. If you experience hangs when you 2171 suspend, try setting this to Y. Otherwise, say N. 2172 2173endif # APM 2174 2175source "drivers/cpufreq/Kconfig" 2176 2177source "drivers/cpuidle/Kconfig" 2178 2179source "drivers/idle/Kconfig" 2180 2181endmenu 2182 2183 2184menu "Bus options (PCI etc.)" 2185 2186config PCI 2187 bool "PCI support" 2188 default y 2189 ---help--- 2190 Find out whether you have a PCI motherboard. PCI is the name of a 2191 bus system, i.e. the way the CPU talks to the other stuff inside 2192 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2193 VESA. If you have PCI, say Y, otherwise N. 2194 2195choice 2196 prompt "PCI access mode" 2197 depends on X86_32 && PCI 2198 default PCI_GOANY 2199 ---help--- 2200 On PCI systems, the BIOS can be used to detect the PCI devices and 2201 determine their configuration. However, some old PCI motherboards 2202 have BIOS bugs and may crash if this is done. Also, some embedded 2203 PCI-based systems don't have any BIOS at all. Linux can also try to 2204 detect the PCI hardware directly without using the BIOS. 2205 2206 With this option, you can specify how Linux should detect the 2207 PCI devices. If you choose "BIOS", the BIOS will be used, 2208 if you choose "Direct", the BIOS won't be used, and if you 2209 choose "MMConfig", then PCI Express MMCONFIG will be used. 2210 If you choose "Any", the kernel will try MMCONFIG, then the 2211 direct access method and falls back to the BIOS if that doesn't 2212 work. If unsure, go with the default, which is "Any". 2213 2214config PCI_GOBIOS 2215 bool "BIOS" 2216 2217config PCI_GOMMCONFIG 2218 bool "MMConfig" 2219 2220config PCI_GODIRECT 2221 bool "Direct" 2222 2223config PCI_GOOLPC 2224 bool "OLPC XO-1" 2225 depends on OLPC 2226 2227config PCI_GOANY 2228 bool "Any" 2229 2230endchoice 2231 2232config PCI_BIOS 2233 def_bool y 2234 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2235 2236# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2237config PCI_DIRECT 2238 def_bool y 2239 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2240 2241config PCI_MMCONFIG 2242 def_bool y 2243 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2244 2245config PCI_OLPC 2246 def_bool y 2247 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2248 2249config PCI_XEN 2250 def_bool y 2251 depends on PCI && XEN 2252 select SWIOTLB_XEN 2253 2254config PCI_DOMAINS 2255 def_bool y 2256 depends on PCI 2257 2258config PCI_MMCONFIG 2259 bool "Support mmconfig PCI config space access" 2260 depends on X86_64 && PCI && ACPI 2261 2262config PCI_CNB20LE_QUIRK 2263 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2264 depends on PCI 2265 help 2266 Read the PCI windows out of the CNB20LE host bridge. This allows 2267 PCI hotplug to work on systems with the CNB20LE chipset which do 2268 not have ACPI. 2269 2270 There's no public spec for this chipset, and this functionality 2271 is known to be incomplete. 2272 2273 You should say N unless you know you need this. 2274 2275source "drivers/pci/pcie/Kconfig" 2276 2277source "drivers/pci/Kconfig" 2278 2279# x86_64 have no ISA slots, but can have ISA-style DMA. 2280config ISA_DMA_API 2281 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2282 default y 2283 help 2284 Enables ISA-style DMA support for devices requiring such controllers. 2285 If unsure, say Y. 2286 2287if X86_32 2288 2289config ISA 2290 bool "ISA support" 2291 ---help--- 2292 Find out whether you have ISA slots on your motherboard. ISA is the 2293 name of a bus system, i.e. the way the CPU talks to the other stuff 2294 inside your box. Other bus systems are PCI, EISA, MicroChannel 2295 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2296 newer boards don't support it. If you have ISA, say Y, otherwise N. 2297 2298config EISA 2299 bool "EISA support" 2300 depends on ISA 2301 ---help--- 2302 The Extended Industry Standard Architecture (EISA) bus was 2303 developed as an open alternative to the IBM MicroChannel bus. 2304 2305 The EISA bus provided some of the features of the IBM MicroChannel 2306 bus while maintaining backward compatibility with cards made for 2307 the older ISA bus. The EISA bus saw limited use between 1988 and 2308 1995 when it was made obsolete by the PCI bus. 2309 2310 Say Y here if you are building a kernel for an EISA-based machine. 2311 2312 Otherwise, say N. 2313 2314source "drivers/eisa/Kconfig" 2315 2316config SCx200 2317 tristate "NatSemi SCx200 support" 2318 ---help--- 2319 This provides basic support for National Semiconductor's 2320 (now AMD's) Geode processors. The driver probes for the 2321 PCI-IDs of several on-chip devices, so its a good dependency 2322 for other scx200_* drivers. 2323 2324 If compiled as a module, the driver is named scx200. 2325 2326config SCx200HR_TIMER 2327 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2328 depends on SCx200 2329 default y 2330 ---help--- 2331 This driver provides a clocksource built upon the on-chip 2332 27MHz high-resolution timer. Its also a workaround for 2333 NSC Geode SC-1100's buggy TSC, which loses time when the 2334 processor goes idle (as is done by the scheduler). The 2335 other workaround is idle=poll boot option. 2336 2337config OLPC 2338 bool "One Laptop Per Child support" 2339 depends on !X86_PAE 2340 select GPIOLIB 2341 select OF 2342 select OF_PROMTREE 2343 select IRQ_DOMAIN 2344 ---help--- 2345 Add support for detecting the unique features of the OLPC 2346 XO hardware. 2347 2348config OLPC_XO1_PM 2349 bool "OLPC XO-1 Power Management" 2350 depends on OLPC && MFD_CS5535 && PM_SLEEP 2351 select MFD_CORE 2352 ---help--- 2353 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2354 2355config OLPC_XO1_RTC 2356 bool "OLPC XO-1 Real Time Clock" 2357 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2358 ---help--- 2359 Add support for the XO-1 real time clock, which can be used as a 2360 programmable wakeup source. 2361 2362config OLPC_XO1_SCI 2363 bool "OLPC XO-1 SCI extras" 2364 depends on OLPC && OLPC_XO1_PM 2365 depends on INPUT=y 2366 select POWER_SUPPLY 2367 select GPIO_CS5535 2368 select MFD_CORE 2369 ---help--- 2370 Add support for SCI-based features of the OLPC XO-1 laptop: 2371 - EC-driven system wakeups 2372 - Power button 2373 - Ebook switch 2374 - Lid switch 2375 - AC adapter status updates 2376 - Battery status updates 2377 2378config OLPC_XO15_SCI 2379 bool "OLPC XO-1.5 SCI extras" 2380 depends on OLPC && ACPI 2381 select POWER_SUPPLY 2382 ---help--- 2383 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2384 - EC-driven system wakeups 2385 - AC adapter status updates 2386 - Battery status updates 2387 2388config ALIX 2389 bool "PCEngines ALIX System Support (LED setup)" 2390 select GPIOLIB 2391 ---help--- 2392 This option enables system support for the PCEngines ALIX. 2393 At present this just sets up LEDs for GPIO control on 2394 ALIX2/3/6 boards. However, other system specific setup should 2395 get added here. 2396 2397 Note: You must still enable the drivers for GPIO and LED support 2398 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2399 2400 Note: You have to set alix.force=1 for boards with Award BIOS. 2401 2402config NET5501 2403 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2404 select GPIOLIB 2405 ---help--- 2406 This option enables system support for the Soekris Engineering net5501. 2407 2408config GEOS 2409 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2410 select GPIOLIB 2411 depends on DMI 2412 ---help--- 2413 This option enables system support for the Traverse Technologies GEOS. 2414 2415config TS5500 2416 bool "Technologic Systems TS-5500 platform support" 2417 depends on MELAN 2418 select CHECK_SIGNATURE 2419 select NEW_LEDS 2420 select LEDS_CLASS 2421 ---help--- 2422 This option enables system support for the Technologic Systems TS-5500. 2423 2424endif # X86_32 2425 2426config AMD_NB 2427 def_bool y 2428 depends on CPU_SUP_AMD && PCI 2429 2430source "drivers/pcmcia/Kconfig" 2431 2432source "drivers/pci/hotplug/Kconfig" 2433 2434config RAPIDIO 2435 tristate "RapidIO support" 2436 depends on PCI 2437 default n 2438 help 2439 If enabled this option will include drivers and the core 2440 infrastructure code to support RapidIO interconnect devices. 2441 2442source "drivers/rapidio/Kconfig" 2443 2444config X86_SYSFB 2445 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2446 help 2447 Firmwares often provide initial graphics framebuffers so the BIOS, 2448 bootloader or kernel can show basic video-output during boot for 2449 user-guidance and debugging. Historically, x86 used the VESA BIOS 2450 Extensions and EFI-framebuffers for this, which are mostly limited 2451 to x86. 2452 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2453 framebuffers so the new generic system-framebuffer drivers can be 2454 used on x86. If the framebuffer is not compatible with the generic 2455 modes, it is adverticed as fallback platform framebuffer so legacy 2456 drivers like efifb, vesafb and uvesafb can pick it up. 2457 If this option is not selected, all system framebuffers are always 2458 marked as fallback platform framebuffers as usual. 2459 2460 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2461 not be able to pick up generic system framebuffers if this option 2462 is selected. You are highly encouraged to enable simplefb as 2463 replacement if you select this option. simplefb can correctly deal 2464 with generic system framebuffers. But you should still keep vesafb 2465 and others enabled as fallback if a system framebuffer is 2466 incompatible with simplefb. 2467 2468 If unsure, say Y. 2469 2470endmenu 2471 2472 2473menu "Executable file formats / Emulations" 2474 2475source "fs/Kconfig.binfmt" 2476 2477config IA32_EMULATION 2478 bool "IA32 Emulation" 2479 depends on X86_64 2480 select BINFMT_ELF 2481 select COMPAT_BINFMT_ELF 2482 select HAVE_UID16 2483 ---help--- 2484 Include code to run legacy 32-bit programs under a 2485 64-bit kernel. You should likely turn this on, unless you're 2486 100% sure that you don't have any 32-bit programs left. 2487 2488config IA32_AOUT 2489 tristate "IA32 a.out support" 2490 depends on IA32_EMULATION 2491 ---help--- 2492 Support old a.out binaries in the 32bit emulation. 2493 2494config X86_X32 2495 bool "x32 ABI for 64-bit mode" 2496 depends on X86_64 && IA32_EMULATION 2497 ---help--- 2498 Include code to run binaries for the x32 native 32-bit ABI 2499 for 64-bit processors. An x32 process gets access to the 2500 full 64-bit register file and wide data path while leaving 2501 pointers at 32 bits for smaller memory footprint. 2502 2503 You will need a recent binutils (2.22 or later) with 2504 elf32_x86_64 support enabled to compile a kernel with this 2505 option set. 2506 2507config COMPAT 2508 def_bool y 2509 depends on IA32_EMULATION || X86_X32 2510 select ARCH_WANT_OLD_COMPAT_IPC 2511 2512if COMPAT 2513config COMPAT_FOR_U64_ALIGNMENT 2514 def_bool y 2515 2516config SYSVIPC_COMPAT 2517 def_bool y 2518 depends on SYSVIPC 2519 2520config KEYS_COMPAT 2521 def_bool y 2522 depends on KEYS 2523endif 2524 2525endmenu 2526 2527 2528config HAVE_ATOMIC_IOMAP 2529 def_bool y 2530 depends on X86_32 2531 2532config X86_DEV_DMA_OPS 2533 bool 2534 depends on X86_64 || STA2X11 2535 2536config X86_DMA_REMAP 2537 bool 2538 depends on STA2X11 2539 2540config PMC_ATOM 2541 def_bool y 2542 depends on PCI 2543 2544source "net/Kconfig" 2545 2546source "drivers/Kconfig" 2547 2548source "drivers/firmware/Kconfig" 2549 2550source "fs/Kconfig" 2551 2552source "arch/x86/Kconfig.debug" 2553 2554source "security/Kconfig" 2555 2556source "crypto/Kconfig" 2557 2558source "arch/x86/kvm/Kconfig" 2559 2560source "lib/Kconfig" 2561