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 HAVE_AOUT if X86_32 27 select HAVE_UNSTABLE_SCHED_CLOCK 28 select ARCH_SUPPORTS_NUMA_BALANCING 29 select ARCH_WANTS_PROT_NUMA_PROT_NONE 30 select HAVE_IDE 31 select HAVE_OPROFILE 32 select HAVE_PCSPKR_PLATFORM 33 select HAVE_PERF_EVENTS 34 select HAVE_IOREMAP_PROT 35 select HAVE_KPROBES 36 select HAVE_MEMBLOCK 37 select HAVE_MEMBLOCK_NODE_MAP 38 select ARCH_DISCARD_MEMBLOCK 39 select ARCH_WANT_OPTIONAL_GPIOLIB 40 select ARCH_WANT_FRAME_POINTERS 41 select HAVE_DMA_ATTRS 42 select HAVE_DMA_CONTIGUOUS if !SWIOTLB 43 select HAVE_KRETPROBES 44 select HAVE_OPTPROBES 45 select HAVE_KPROBES_ON_FTRACE 46 select HAVE_FTRACE_MCOUNT_RECORD 47 select HAVE_FENTRY if X86_64 48 select HAVE_C_RECORDMCOUNT 49 select HAVE_DYNAMIC_FTRACE 50 select HAVE_DYNAMIC_FTRACE_WITH_REGS 51 select HAVE_FUNCTION_TRACER 52 select HAVE_FUNCTION_GRAPH_TRACER 53 select HAVE_FUNCTION_GRAPH_FP_TEST 54 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 55 select HAVE_SYSCALL_TRACEPOINTS 56 select SYSCTL_EXCEPTION_TRACE 57 select HAVE_KVM 58 select HAVE_ARCH_KGDB 59 select HAVE_ARCH_TRACEHOOK 60 select HAVE_GENERIC_DMA_COHERENT if X86_32 61 select HAVE_EFFICIENT_UNALIGNED_ACCESS 62 select USER_STACKTRACE_SUPPORT 63 select HAVE_REGS_AND_STACK_ACCESS_API 64 select HAVE_DMA_API_DEBUG 65 select HAVE_KERNEL_GZIP 66 select HAVE_KERNEL_BZIP2 67 select HAVE_KERNEL_LZMA 68 select HAVE_KERNEL_XZ 69 select HAVE_KERNEL_LZO 70 select HAVE_KERNEL_LZ4 71 select HAVE_HW_BREAKPOINT 72 select HAVE_MIXED_BREAKPOINTS_REGS 73 select PERF_EVENTS 74 select HAVE_PERF_EVENTS_NMI 75 select HAVE_PERF_REGS 76 select HAVE_PERF_USER_STACK_DUMP 77 select HAVE_DEBUG_KMEMLEAK 78 select ANON_INODES 79 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 80 select HAVE_CMPXCHG_LOCAL 81 select HAVE_CMPXCHG_DOUBLE 82 select HAVE_ARCH_KMEMCHECK 83 select HAVE_USER_RETURN_NOTIFIER 84 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 85 select HAVE_ARCH_JUMP_LABEL 86 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 87 select SPARSE_IRQ 88 select GENERIC_FIND_FIRST_BIT 89 select GENERIC_IRQ_PROBE 90 select GENERIC_PENDING_IRQ if SMP 91 select GENERIC_IRQ_SHOW 92 select GENERIC_CLOCKEVENTS_MIN_ADJUST 93 select IRQ_FORCED_THREADING 94 select HAVE_BPF_JIT if X86_64 95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 96 select CLKEVT_I8253 97 select ARCH_HAVE_NMI_SAFE_CMPXCHG 98 select GENERIC_IOMAP 99 select DCACHE_WORD_ACCESS 100 select GENERIC_SMP_IDLE_THREAD 101 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 102 select HAVE_ARCH_SECCOMP_FILTER 103 select BUILDTIME_EXTABLE_SORT 104 select GENERIC_CMOS_UPDATE 105 select HAVE_ARCH_SOFT_DIRTY 106 select CLOCKSOURCE_WATCHDOG 107 select GENERIC_CLOCKEVENTS 108 select ARCH_CLOCKSOURCE_DATA if X86_64 109 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 110 select GENERIC_TIME_VSYSCALL if X86_64 111 select KTIME_SCALAR if X86_32 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select HAVE_CONTEXT_TRACKING if X86_64 115 select HAVE_IRQ_TIME_ACCOUNTING 116 select VIRT_TO_BUS 117 select MODULES_USE_ELF_REL if X86_32 118 select MODULES_USE_ELF_RELA if X86_64 119 select CLONE_BACKWARDS if X86_32 120 select ARCH_USE_BUILTIN_BSWAP 121 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 122 select OLD_SIGACTION if X86_32 123 select COMPAT_OLD_SIGACTION if IA32_EMULATION 124 select RTC_LIB 125 select HAVE_DEBUG_STACKOVERFLOW 126 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 127 128config INSTRUCTION_DECODER 129 def_bool y 130 depends on KPROBES || PERF_EVENTS || UPROBES 131 132config OUTPUT_FORMAT 133 string 134 default "elf32-i386" if X86_32 135 default "elf64-x86-64" if X86_64 136 137config ARCH_DEFCONFIG 138 string 139 default "arch/x86/configs/i386_defconfig" if X86_32 140 default "arch/x86/configs/x86_64_defconfig" if X86_64 141 142config LOCKDEP_SUPPORT 143 def_bool y 144 145config STACKTRACE_SUPPORT 146 def_bool y 147 148config HAVE_LATENCYTOP_SUPPORT 149 def_bool y 150 151config MMU 152 def_bool y 153 154config SBUS 155 bool 156 157config NEED_DMA_MAP_STATE 158 def_bool y 159 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 160 161config NEED_SG_DMA_LENGTH 162 def_bool y 163 164config GENERIC_ISA_DMA 165 def_bool y 166 depends on ISA_DMA_API 167 168config GENERIC_BUG 169 def_bool y 170 depends on BUG 171 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 172 173config GENERIC_BUG_RELATIVE_POINTERS 174 bool 175 176config GENERIC_HWEIGHT 177 def_bool y 178 179config ARCH_MAY_HAVE_PC_FDC 180 def_bool y 181 depends on ISA_DMA_API 182 183config RWSEM_XCHGADD_ALGORITHM 184 def_bool y 185 186config GENERIC_CALIBRATE_DELAY 187 def_bool y 188 189config ARCH_HAS_CPU_RELAX 190 def_bool y 191 192config ARCH_HAS_CACHE_LINE_SIZE 193 def_bool y 194 195config ARCH_HAS_CPU_AUTOPROBE 196 def_bool y 197 198config HAVE_SETUP_PER_CPU_AREA 199 def_bool y 200 201config NEED_PER_CPU_EMBED_FIRST_CHUNK 202 def_bool y 203 204config NEED_PER_CPU_PAGE_FIRST_CHUNK 205 def_bool y 206 207config ARCH_HIBERNATION_POSSIBLE 208 def_bool y 209 210config ARCH_SUSPEND_POSSIBLE 211 def_bool y 212 213config ARCH_WANT_HUGE_PMD_SHARE 214 def_bool y 215 216config ARCH_WANT_GENERAL_HUGETLB 217 def_bool y 218 219config ZONE_DMA32 220 bool 221 default X86_64 222 223config AUDIT_ARCH 224 bool 225 default X86_64 226 227config ARCH_SUPPORTS_OPTIMIZED_INLINING 228 def_bool y 229 230config ARCH_SUPPORTS_DEBUG_PAGEALLOC 231 def_bool y 232 233config HAVE_INTEL_TXT 234 def_bool y 235 depends on INTEL_IOMMU && ACPI 236 237config X86_32_SMP 238 def_bool y 239 depends on X86_32 && SMP 240 241config X86_64_SMP 242 def_bool y 243 depends on X86_64 && SMP 244 245config X86_HT 246 def_bool y 247 depends on SMP 248 249config X86_32_LAZY_GS 250 def_bool y 251 depends on X86_32 && !CC_STACKPROTECTOR 252 253config ARCH_HWEIGHT_CFLAGS 254 string 255 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 256 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_64 257 258config ARCH_SUPPORTS_UPROBES 259 def_bool y 260 261source "init/Kconfig" 262source "kernel/Kconfig.freezer" 263 264menu "Processor type and features" 265 266config ZONE_DMA 267 bool "DMA memory allocation support" if EXPERT 268 default y 269 help 270 DMA memory allocation support allows devices with less than 32-bit 271 addressing to allocate within the first 16MB of address space. 272 Disable if no such devices will be used. 273 274 If unsure, say Y. 275 276config SMP 277 bool "Symmetric multi-processing support" 278 ---help--- 279 This enables support for systems with more than one CPU. If you have 280 a system with only one CPU, like most personal computers, say N. If 281 you have a system with more than one CPU, say Y. 282 283 If you say N here, the kernel will run on single and multiprocessor 284 machines, but will use only one CPU of a multiprocessor machine. If 285 you say Y here, the kernel will run on many, but not all, 286 singleprocessor machines. On a singleprocessor machine, the kernel 287 will run faster if you say N here. 288 289 Note that if you say Y here and choose architecture "586" or 290 "Pentium" under "Processor family", the kernel will not work on 486 291 architectures. Similarly, multiprocessor kernels for the "PPro" 292 architecture may not work on all Pentium based boards. 293 294 People using multiprocessor machines who say Y here should also say 295 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 296 Management" code will be disabled if you say Y here. 297 298 See also <file:Documentation/x86/i386/IO-APIC.txt>, 299 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 300 <http://www.tldp.org/docs.html#howto>. 301 302 If you don't know what to do here, say N. 303 304config X86_X2APIC 305 bool "Support x2apic" 306 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 307 ---help--- 308 This enables x2apic support on CPUs that have this feature. 309 310 This allows 32-bit apic IDs (so it can support very large systems), 311 and accesses the local apic via MSRs not via mmio. 312 313 If you don't know what to do here, say N. 314 315config X86_MPPARSE 316 bool "Enable MPS table" if ACPI || SFI 317 default y 318 depends on X86_LOCAL_APIC 319 ---help--- 320 For old smp systems that do not have proper acpi support. Newer systems 321 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 322 323config X86_BIGSMP 324 bool "Support for big SMP systems with more than 8 CPUs" 325 depends on X86_32 && SMP 326 ---help--- 327 This option is needed for the systems that have more than 8 CPUs 328 329config GOLDFISH 330 def_bool y 331 depends on X86_GOLDFISH 332 333if X86_32 334config X86_EXTENDED_PLATFORM 335 bool "Support for extended (non-PC) x86 platforms" 336 default y 337 ---help--- 338 If you disable this option then the kernel will only support 339 standard PC platforms. (which covers the vast majority of 340 systems out there.) 341 342 If you enable this option then you'll be able to select support 343 for the following (non-PC) 32 bit x86 platforms: 344 Goldfish (Android emulator) 345 AMD Elan 346 NUMAQ (IBM/Sequent) 347 RDC R-321x SoC 348 SGI 320/540 (Visual Workstation) 349 STA2X11-based (e.g. Northville) 350 Summit/EXA (IBM x440) 351 Unisys ES7000 IA32 series 352 Moorestown MID devices 353 354 If you have one of these systems, or if you want to build a 355 generic distribution kernel, say Y here - otherwise say N. 356endif 357 358if X86_64 359config X86_EXTENDED_PLATFORM 360 bool "Support for extended (non-PC) x86 platforms" 361 default y 362 ---help--- 363 If you disable this option then the kernel will only support 364 standard PC platforms. (which covers the vast majority of 365 systems out there.) 366 367 If you enable this option then you'll be able to select support 368 for the following (non-PC) 64 bit x86 platforms: 369 Numascale NumaChip 370 ScaleMP vSMP 371 SGI Ultraviolet 372 373 If you have one of these systems, or if you want to build a 374 generic distribution kernel, say Y here - otherwise say N. 375endif 376# This is an alphabetically sorted list of 64 bit extended platforms 377# Please maintain the alphabetic order if and when there are additions 378config X86_NUMACHIP 379 bool "Numascale NumaChip" 380 depends on X86_64 381 depends on X86_EXTENDED_PLATFORM 382 depends on NUMA 383 depends on SMP 384 depends on X86_X2APIC 385 depends on PCI_MMCONFIG 386 ---help--- 387 Adds support for Numascale NumaChip large-SMP systems. Needed to 388 enable more than ~168 cores. 389 If you don't have one of these, you should say N here. 390 391config X86_VSMP 392 bool "ScaleMP vSMP" 393 select HYPERVISOR_GUEST 394 select PARAVIRT 395 depends on X86_64 && PCI 396 depends on X86_EXTENDED_PLATFORM 397 depends on SMP 398 ---help--- 399 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 400 supposed to run on these EM64T-based machines. Only choose this option 401 if you have one of these machines. 402 403config X86_UV 404 bool "SGI Ultraviolet" 405 depends on X86_64 406 depends on X86_EXTENDED_PLATFORM 407 depends on NUMA 408 depends on X86_X2APIC 409 ---help--- 410 This option is needed in order to support SGI Ultraviolet systems. 411 If you don't have one of these, you should say N here. 412 413# Following is an alphabetically sorted list of 32 bit extended platforms 414# Please maintain the alphabetic order if and when there are additions 415 416config X86_GOLDFISH 417 bool "Goldfish (Virtual Platform)" 418 depends on X86_32 419 depends on X86_EXTENDED_PLATFORM 420 ---help--- 421 Enable support for the Goldfish virtual platform used primarily 422 for Android development. Unless you are building for the Android 423 Goldfish emulator say N here. 424 425config X86_INTEL_CE 426 bool "CE4100 TV platform" 427 depends on PCI 428 depends on PCI_GODIRECT 429 depends on X86_32 430 depends on X86_EXTENDED_PLATFORM 431 select X86_REBOOTFIXUPS 432 select OF 433 select OF_EARLY_FLATTREE 434 select IRQ_DOMAIN 435 ---help--- 436 Select for the Intel CE media processor (CE4100) SOC. 437 This option compiles in support for the CE4100 SOC for settop 438 boxes and media devices. 439 440config X86_WANT_INTEL_MID 441 bool "Intel MID platform support" 442 depends on X86_32 443 depends on X86_EXTENDED_PLATFORM 444 ---help--- 445 Select to build a kernel capable of supporting Intel MID platform 446 systems which do not have the PCI legacy interfaces (Moorestown, 447 Medfield). If you are building for a PC class system say N here. 448 449if X86_WANT_INTEL_MID 450 451config X86_INTEL_MID 452 bool 453 454config X86_MDFLD 455 bool "Medfield MID platform" 456 depends on PCI 457 depends on PCI_GOANY 458 depends on X86_IO_APIC 459 select X86_INTEL_MID 460 select SFI 461 select DW_APB_TIMER 462 select APB_TIMER 463 select I2C 464 select SPI 465 select INTEL_SCU_IPC 466 select X86_PLATFORM_DEVICES 467 select MFD_INTEL_MSIC 468 ---help--- 469 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin 470 Internet Device(MID) platform. 471 Unlike standard x86 PCs, Medfield does not have many legacy devices 472 nor standard legacy replacement devices/features. e.g. Medfield does 473 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 474 475endif 476 477config X86_INTEL_LPSS 478 bool "Intel Low Power Subsystem Support" 479 depends on ACPI 480 select COMMON_CLK 481 select PINCTRL 482 ---help--- 483 Select to build support for Intel Low Power Subsystem such as 484 found on Intel Lynxpoint PCH. Selecting this option enables 485 things like clock tree (common clock framework) and pincontrol 486 which are needed by the LPSS peripheral drivers. 487 488config X86_RDC321X 489 bool "RDC R-321x SoC" 490 depends on X86_32 491 depends on X86_EXTENDED_PLATFORM 492 select M486 493 select X86_REBOOTFIXUPS 494 ---help--- 495 This option is needed for RDC R-321x system-on-chip, also known 496 as R-8610-(G). 497 If you don't have one of these chips, you should say N here. 498 499config X86_32_NON_STANDARD 500 bool "Support non-standard 32-bit SMP architectures" 501 depends on X86_32 && SMP 502 depends on X86_EXTENDED_PLATFORM 503 ---help--- 504 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, 505 STA2X11, default subarchitectures. It is intended for a generic 506 binary kernel. If you select them all, kernel will probe it 507 one by one and will fallback to default. 508 509# Alphabetically sorted list of Non standard 32 bit platforms 510 511config X86_NUMAQ 512 bool "NUMAQ (IBM/Sequent)" 513 depends on X86_32_NON_STANDARD 514 depends on PCI 515 select NUMA 516 select X86_MPPARSE 517 ---help--- 518 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 519 NUMA multiquad box. This changes the way that processors are 520 bootstrapped, and uses Clustered Logical APIC addressing mode instead 521 of Flat Logical. You will need a new lynxer.elf file to flash your 522 firmware with - send email to <Martin.Bligh@us.ibm.com>. 523 524config X86_SUPPORTS_MEMORY_FAILURE 525 def_bool y 526 # MCE code calls memory_failure(): 527 depends on X86_MCE 528 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 529 depends on !X86_NUMAQ 530 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 531 depends on X86_64 || !SPARSEMEM 532 select ARCH_SUPPORTS_MEMORY_FAILURE 533 534config X86_VISWS 535 bool "SGI 320/540 (Visual Workstation)" 536 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 537 depends on X86_32_NON_STANDARD 538 ---help--- 539 The SGI Visual Workstation series is an IA32-based workstation 540 based on SGI systems chips with some legacy PC hardware attached. 541 542 Say Y here to create a kernel to run on the SGI 320 or 540. 543 544 A kernel compiled for the Visual Workstation will run on general 545 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 546 547config STA2X11 548 bool "STA2X11 Companion Chip Support" 549 depends on X86_32_NON_STANDARD && PCI 550 select X86_DEV_DMA_OPS 551 select X86_DMA_REMAP 552 select SWIOTLB 553 select MFD_STA2X11 554 select ARCH_REQUIRE_GPIOLIB 555 default n 556 ---help--- 557 This adds support for boards based on the STA2X11 IO-Hub, 558 a.k.a. "ConneXt". The chip is used in place of the standard 559 PC chipset, so all "standard" peripherals are missing. If this 560 option is selected the kernel will still be able to boot on 561 standard PC machines. 562 563config X86_SUMMIT 564 bool "Summit/EXA (IBM x440)" 565 depends on X86_32_NON_STANDARD 566 ---help--- 567 This option is needed for IBM systems that use the Summit/EXA chipset. 568 In particular, it is needed for the x440. 569 570config X86_ES7000 571 bool "Unisys ES7000 IA32 series" 572 depends on X86_32_NON_STANDARD && X86_BIGSMP 573 ---help--- 574 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 575 supposed to run on an IA32-based Unisys ES7000 system. 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 699config X86_SUMMIT_NUMA 700 def_bool y 701 depends on X86_32 && NUMA && X86_32_NON_STANDARD 702 703config X86_CYCLONE_TIMER 704 def_bool y 705 depends on X86_SUMMIT 706 707source "arch/x86/Kconfig.cpu" 708 709config HPET_TIMER 710 def_bool X86_64 711 prompt "HPET Timer Support" if X86_32 712 ---help--- 713 Use the IA-PC HPET (High Precision Event Timer) to manage 714 time in preference to the PIT and RTC, if a HPET is 715 present. 716 HPET is the next generation timer replacing legacy 8254s. 717 The HPET provides a stable time base on SMP 718 systems, unlike the TSC, but it is more expensive to access, 719 as it is off-chip. You can find the HPET spec at 720 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 721 722 You can safely choose Y here. However, HPET will only be 723 activated if the platform and the BIOS support this feature. 724 Otherwise the 8254 will be used for timing services. 725 726 Choose N to continue using the legacy 8254 timer. 727 728config HPET_EMULATE_RTC 729 def_bool y 730 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 731 732config APB_TIMER 733 def_bool y if X86_INTEL_MID 734 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 735 select DW_APB_TIMER 736 depends on X86_INTEL_MID && SFI 737 help 738 APB timer is the replacement for 8254, HPET on X86 MID platforms. 739 The APBT provides a stable time base on SMP 740 systems, unlike the TSC, but it is more expensive to access, 741 as it is off-chip. APB timers are always running regardless of CPU 742 C states, they are used as per CPU clockevent device when possible. 743 744# Mark as expert because too many people got it wrong. 745# The code disables itself when not needed. 746config DMI 747 default y 748 bool "Enable DMI scanning" if EXPERT 749 ---help--- 750 Enabled scanning of DMI to identify machine quirks. Say Y 751 here unless you have verified that your setup is not 752 affected by entries in the DMI blacklist. Required by PNP 753 BIOS code. 754 755config GART_IOMMU 756 bool "Old AMD GART IOMMU support" 757 select SWIOTLB 758 depends on X86_64 && PCI && AMD_NB 759 ---help--- 760 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 761 GART based hardware IOMMUs. 762 763 The GART supports full DMA access for devices with 32-bit access 764 limitations, on systems with more than 3 GB. This is usually needed 765 for USB, sound, many IDE/SATA chipsets and some other devices. 766 767 Newer systems typically have a modern AMD IOMMU, supported via 768 the CONFIG_AMD_IOMMU=y config option. 769 770 In normal configurations this driver is only active when needed: 771 there's more than 3 GB of memory and the system contains a 772 32-bit limited device. 773 774 If unsure, say Y. 775 776config CALGARY_IOMMU 777 bool "IBM Calgary IOMMU support" 778 select SWIOTLB 779 depends on X86_64 && PCI 780 ---help--- 781 Support for hardware IOMMUs in IBM's xSeries x366 and x460 782 systems. Needed to run systems with more than 3GB of memory 783 properly with 32-bit PCI devices that do not support DAC 784 (Double Address Cycle). Calgary also supports bus level 785 isolation, where all DMAs pass through the IOMMU. This 786 prevents them from going anywhere except their intended 787 destination. This catches hard-to-find kernel bugs and 788 mis-behaving drivers and devices that do not use the DMA-API 789 properly to set up their DMA buffers. The IOMMU can be 790 turned off at boot time with the iommu=off parameter. 791 Normally the kernel will make the right choice by itself. 792 If unsure, say Y. 793 794config CALGARY_IOMMU_ENABLED_BY_DEFAULT 795 def_bool y 796 prompt "Should Calgary be enabled by default?" 797 depends on CALGARY_IOMMU 798 ---help--- 799 Should Calgary be enabled by default? if you choose 'y', Calgary 800 will be used (if it exists). If you choose 'n', Calgary will not be 801 used even if it exists. If you choose 'n' and would like to use 802 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 803 If unsure, say Y. 804 805# need this always selected by IOMMU for the VIA workaround 806config SWIOTLB 807 def_bool y if X86_64 808 ---help--- 809 Support for software bounce buffers used on x86-64 systems 810 which don't have a hardware IOMMU. Using this PCI devices 811 which can only access 32-bits of memory can be used on systems 812 with more than 3 GB of memory. 813 If unsure, say Y. 814 815config IOMMU_HELPER 816 def_bool y 817 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 818 819config MAXSMP 820 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 821 depends on X86_64 && SMP && DEBUG_KERNEL 822 select CPUMASK_OFFSTACK 823 ---help--- 824 Enable maximum number of CPUS and NUMA Nodes for this architecture. 825 If unsure, say N. 826 827config NR_CPUS 828 int "Maximum number of CPUs" if SMP && !MAXSMP 829 range 2 8 if SMP && X86_32 && !X86_BIGSMP 830 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 831 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 832 default "1" if !SMP 833 default "8192" if MAXSMP 834 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 835 default "8" if SMP 836 ---help--- 837 This allows you to specify the maximum number of CPUs which this 838 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 839 supported value is 4096, otherwise the maximum value is 512. The 840 minimum value which makes sense is 2. 841 842 This is purely to save memory - each supported CPU adds 843 approximately eight kilobytes to the kernel image. 844 845config SCHED_SMT 846 bool "SMT (Hyperthreading) scheduler support" 847 depends on X86_HT 848 ---help--- 849 SMT scheduler support improves the CPU scheduler's decision making 850 when dealing with Intel Pentium 4 chips with HyperThreading at a 851 cost of slightly increased overhead in some places. If unsure say 852 N here. 853 854config SCHED_MC 855 def_bool y 856 prompt "Multi-core scheduler support" 857 depends on X86_HT 858 ---help--- 859 Multi-core scheduler support improves the CPU scheduler's decision 860 making when dealing with multi-core CPU chips at a cost of slightly 861 increased overhead in some places. If unsure say N here. 862 863source "kernel/Kconfig.preempt" 864 865config X86_UP_APIC 866 bool "Local APIC support on uniprocessors" 867 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 868 ---help--- 869 A local APIC (Advanced Programmable Interrupt Controller) is an 870 integrated interrupt controller in the CPU. If you have a single-CPU 871 system which has a processor with a local APIC, you can say Y here to 872 enable and use it. If you say Y here even though your machine doesn't 873 have a local APIC, then the kernel will still run with no slowdown at 874 all. The local APIC supports CPU-generated self-interrupts (timer, 875 performance counters), and the NMI watchdog which detects hard 876 lockups. 877 878config X86_UP_IOAPIC 879 bool "IO-APIC support on uniprocessors" 880 depends on X86_UP_APIC 881 ---help--- 882 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 883 SMP-capable replacement for PC-style interrupt controllers. Most 884 SMP systems and many recent uniprocessor systems have one. 885 886 If you have a single-CPU system with an IO-APIC, you can say Y here 887 to use it. If you say Y here even though your machine doesn't have 888 an IO-APIC, then the kernel will still run with no slowdown at all. 889 890config X86_LOCAL_APIC 891 def_bool y 892 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 893 894config X86_IO_APIC 895 def_bool y 896 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 897 898config X86_VISWS_APIC 899 def_bool y 900 depends on X86_32 && X86_VISWS 901 902config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 903 bool "Reroute for broken boot IRQs" 904 depends on X86_IO_APIC 905 ---help--- 906 This option enables a workaround that fixes a source of 907 spurious interrupts. This is recommended when threaded 908 interrupt handling is used on systems where the generation of 909 superfluous "boot interrupts" cannot be disabled. 910 911 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 912 entry in the chipset's IO-APIC is masked (as, e.g. the RT 913 kernel does during interrupt handling). On chipsets where this 914 boot IRQ generation cannot be disabled, this workaround keeps 915 the original IRQ line masked so that only the equivalent "boot 916 IRQ" is delivered to the CPUs. The workaround also tells the 917 kernel to set up the IRQ handler on the boot IRQ line. In this 918 way only one interrupt is delivered to the kernel. Otherwise 919 the spurious second interrupt may cause the kernel to bring 920 down (vital) interrupt lines. 921 922 Only affects "broken" chipsets. Interrupt sharing may be 923 increased on these systems. 924 925config X86_MCE 926 bool "Machine Check / overheating reporting" 927 default y 928 ---help--- 929 Machine Check support allows the processor to notify the 930 kernel if it detects a problem (e.g. overheating, data corruption). 931 The action the kernel takes depends on the severity of the problem, 932 ranging from warning messages to halting the machine. 933 934config X86_MCE_INTEL 935 def_bool y 936 prompt "Intel MCE features" 937 depends on X86_MCE && X86_LOCAL_APIC 938 ---help--- 939 Additional support for intel specific MCE features such as 940 the thermal monitor. 941 942config X86_MCE_AMD 943 def_bool y 944 prompt "AMD MCE features" 945 depends on X86_MCE && X86_LOCAL_APIC 946 ---help--- 947 Additional support for AMD specific MCE features such as 948 the DRAM Error Threshold. 949 950config X86_ANCIENT_MCE 951 bool "Support for old Pentium 5 / WinChip machine checks" 952 depends on X86_32 && X86_MCE 953 ---help--- 954 Include support for machine check handling on old Pentium 5 or WinChip 955 systems. These typically need to be enabled explicitely on the command 956 line. 957 958config X86_MCE_THRESHOLD 959 depends on X86_MCE_AMD || X86_MCE_INTEL 960 def_bool y 961 962config X86_MCE_INJECT 963 depends on X86_MCE 964 tristate "Machine check injector support" 965 ---help--- 966 Provide support for injecting machine checks for testing purposes. 967 If you don't know what a machine check is and you don't do kernel 968 QA it is safe to say n. 969 970config X86_THERMAL_VECTOR 971 def_bool y 972 depends on X86_MCE_INTEL 973 974config VM86 975 bool "Enable VM86 support" if EXPERT 976 default y 977 depends on X86_32 978 ---help--- 979 This option is required by programs like DOSEMU to run 16-bit legacy 980 code on X86 processors. It also may be needed by software like 981 XFree86 to initialize some video cards via BIOS. Disabling this 982 option saves about 6k. 983 984config TOSHIBA 985 tristate "Toshiba Laptop support" 986 depends on X86_32 987 ---help--- 988 This adds a driver to safely access the System Management Mode of 989 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 990 not work on models with a Phoenix BIOS. The System Management Mode 991 is used to set the BIOS and power saving options on Toshiba portables. 992 993 For information on utilities to make use of this driver see the 994 Toshiba Linux utilities web site at: 995 <http://www.buzzard.org.uk/toshiba/>. 996 997 Say Y if you intend to run this kernel on a Toshiba portable. 998 Say N otherwise. 999 1000config I8K 1001 tristate "Dell laptop support" 1002 select HWMON 1003 ---help--- 1004 This adds a driver to safely access the System Management Mode 1005 of the CPU on the Dell Inspiron 8000. The System Management Mode 1006 is used to read cpu temperature and cooling fan status and to 1007 control the fans on the I8K portables. 1008 1009 This driver has been tested only on the Inspiron 8000 but it may 1010 also work with other Dell laptops. You can force loading on other 1011 models by passing the parameter `force=1' to the module. Use at 1012 your own risk. 1013 1014 For information on utilities to make use of this driver see the 1015 I8K Linux utilities web site at: 1016 <http://people.debian.org/~dz/i8k/> 1017 1018 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1019 Say N otherwise. 1020 1021config X86_REBOOTFIXUPS 1022 bool "Enable X86 board specific fixups for reboot" 1023 depends on X86_32 1024 ---help--- 1025 This enables chipset and/or board specific fixups to be done 1026 in order to get reboot to work correctly. This is only needed on 1027 some combinations of hardware and BIOS. The symptom, for which 1028 this config is intended, is when reboot ends with a stalled/hung 1029 system. 1030 1031 Currently, the only fixup is for the Geode machines using 1032 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1033 1034 Say Y if you want to enable the fixup. Currently, it's safe to 1035 enable this option even if you don't need it. 1036 Say N otherwise. 1037 1038config MICROCODE 1039 tristate "CPU microcode loading support" 1040 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1041 select FW_LOADER 1042 ---help--- 1043 1044 If you say Y here, you will be able to update the microcode on 1045 certain Intel and AMD processors. The Intel support is for the 1046 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1047 Xeon etc. The AMD support is for families 0x10 and later. You will 1048 obviously need the actual microcode binary data itself which is not 1049 shipped with the Linux kernel. 1050 1051 This option selects the general module only, you need to select 1052 at least one vendor specific module as well. 1053 1054 To compile this driver as a module, choose M here: the module 1055 will be called microcode. 1056 1057config MICROCODE_INTEL 1058 bool "Intel microcode loading support" 1059 depends on MICROCODE 1060 default MICROCODE 1061 select FW_LOADER 1062 ---help--- 1063 This options enables microcode patch loading support for Intel 1064 processors. 1065 1066 For latest news and information on obtaining all the required 1067 Intel ingredients for this driver, check: 1068 <http://www.urbanmyth.org/microcode/>. 1069 1070config MICROCODE_AMD 1071 bool "AMD microcode loading support" 1072 depends on MICROCODE 1073 select FW_LOADER 1074 ---help--- 1075 If you select this option, microcode patch loading support for AMD 1076 processors will be enabled. 1077 1078config MICROCODE_OLD_INTERFACE 1079 def_bool y 1080 depends on MICROCODE 1081 1082config MICROCODE_INTEL_LIB 1083 def_bool y 1084 depends on MICROCODE_INTEL 1085 1086config MICROCODE_INTEL_EARLY 1087 def_bool n 1088 1089config MICROCODE_AMD_EARLY 1090 def_bool n 1091 1092config MICROCODE_EARLY 1093 bool "Early load microcode" 1094 depends on MICROCODE=y && BLK_DEV_INITRD 1095 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1096 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1097 default y 1098 help 1099 This option provides functionality to read additional microcode data 1100 at the beginning of initrd image. The data tells kernel to load 1101 microcode to CPU's as early as possible. No functional change if no 1102 microcode data is glued to the initrd, therefore it's safe to say Y. 1103 1104config X86_MSR 1105 tristate "/dev/cpu/*/msr - Model-specific register support" 1106 ---help--- 1107 This device gives privileged processes access to the x86 1108 Model-Specific Registers (MSRs). It is a character device with 1109 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1110 MSR accesses are directed to a specific CPU on multi-processor 1111 systems. 1112 1113config X86_CPUID 1114 tristate "/dev/cpu/*/cpuid - CPU information support" 1115 ---help--- 1116 This device gives processes access to the x86 CPUID instruction to 1117 be executed on a specific processor. It is a character device 1118 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1119 /dev/cpu/31/cpuid. 1120 1121choice 1122 prompt "High Memory Support" 1123 default HIGHMEM64G if X86_NUMAQ 1124 default HIGHMEM4G 1125 depends on X86_32 1126 1127config NOHIGHMEM 1128 bool "off" 1129 depends on !X86_NUMAQ 1130 ---help--- 1131 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1132 However, the address space of 32-bit x86 processors is only 4 1133 Gigabytes large. That means that, if you have a large amount of 1134 physical memory, not all of it can be "permanently mapped" by the 1135 kernel. The physical memory that's not permanently mapped is called 1136 "high memory". 1137 1138 If you are compiling a kernel which will never run on a machine with 1139 more than 1 Gigabyte total physical RAM, answer "off" here (default 1140 choice and suitable for most users). This will result in a "3GB/1GB" 1141 split: 3GB are mapped so that each process sees a 3GB virtual memory 1142 space and the remaining part of the 4GB virtual memory space is used 1143 by the kernel to permanently map as much physical memory as 1144 possible. 1145 1146 If the machine has between 1 and 4 Gigabytes physical RAM, then 1147 answer "4GB" here. 1148 1149 If more than 4 Gigabytes is used then answer "64GB" here. This 1150 selection turns Intel PAE (Physical Address Extension) mode on. 1151 PAE implements 3-level paging on IA32 processors. PAE is fully 1152 supported by Linux, PAE mode is implemented on all recent Intel 1153 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1154 then the kernel will not boot on CPUs that don't support PAE! 1155 1156 The actual amount of total physical memory will either be 1157 auto detected or can be forced by using a kernel command line option 1158 such as "mem=256M". (Try "man bootparam" or see the documentation of 1159 your boot loader (lilo or loadlin) about how to pass options to the 1160 kernel at boot time.) 1161 1162 If unsure, say "off". 1163 1164config HIGHMEM4G 1165 bool "4GB" 1166 depends on !X86_NUMAQ 1167 ---help--- 1168 Select this if you have a 32-bit processor and between 1 and 4 1169 gigabytes of physical RAM. 1170 1171config HIGHMEM64G 1172 bool "64GB" 1173 depends on !M486 1174 select X86_PAE 1175 ---help--- 1176 Select this if you have a 32-bit processor and more than 4 1177 gigabytes of physical RAM. 1178 1179endchoice 1180 1181choice 1182 prompt "Memory split" if EXPERT 1183 default VMSPLIT_3G 1184 depends on X86_32 1185 ---help--- 1186 Select the desired split between kernel and user memory. 1187 1188 If the address range available to the kernel is less than the 1189 physical memory installed, the remaining memory will be available 1190 as "high memory". Accessing high memory is a little more costly 1191 than low memory, as it needs to be mapped into the kernel first. 1192 Note that increasing the kernel address space limits the range 1193 available to user programs, making the address space there 1194 tighter. Selecting anything other than the default 3G/1G split 1195 will also likely make your kernel incompatible with binary-only 1196 kernel modules. 1197 1198 If you are not absolutely sure what you are doing, leave this 1199 option alone! 1200 1201 config VMSPLIT_3G 1202 bool "3G/1G user/kernel split" 1203 config VMSPLIT_3G_OPT 1204 depends on !X86_PAE 1205 bool "3G/1G user/kernel split (for full 1G low memory)" 1206 config VMSPLIT_2G 1207 bool "2G/2G user/kernel split" 1208 config VMSPLIT_2G_OPT 1209 depends on !X86_PAE 1210 bool "2G/2G user/kernel split (for full 2G low memory)" 1211 config VMSPLIT_1G 1212 bool "1G/3G user/kernel split" 1213endchoice 1214 1215config PAGE_OFFSET 1216 hex 1217 default 0xB0000000 if VMSPLIT_3G_OPT 1218 default 0x80000000 if VMSPLIT_2G 1219 default 0x78000000 if VMSPLIT_2G_OPT 1220 default 0x40000000 if VMSPLIT_1G 1221 default 0xC0000000 1222 depends on X86_32 1223 1224config HIGHMEM 1225 def_bool y 1226 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1227 1228config X86_PAE 1229 bool "PAE (Physical Address Extension) Support" 1230 depends on X86_32 && !HIGHMEM4G 1231 ---help--- 1232 PAE is required for NX support, and furthermore enables 1233 larger swapspace support for non-overcommit purposes. It 1234 has the cost of more pagetable lookup overhead, and also 1235 consumes more pagetable space per process. 1236 1237config ARCH_PHYS_ADDR_T_64BIT 1238 def_bool y 1239 depends on X86_64 || X86_PAE 1240 1241config ARCH_DMA_ADDR_T_64BIT 1242 def_bool y 1243 depends on X86_64 || HIGHMEM64G 1244 1245config DIRECT_GBPAGES 1246 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1247 default y 1248 depends on X86_64 1249 ---help--- 1250 Allow the kernel linear mapping to use 1GB pages on CPUs that 1251 support it. This can improve the kernel's performance a tiny bit by 1252 reducing TLB pressure. If in doubt, say "Y". 1253 1254# Common NUMA Features 1255config NUMA 1256 bool "Numa Memory Allocation and Scheduler Support" 1257 depends on SMP 1258 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI)) 1259 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1260 ---help--- 1261 Enable NUMA (Non Uniform Memory Access) support. 1262 1263 The kernel will try to allocate memory used by a CPU on the 1264 local memory controller of the CPU and add some more 1265 NUMA awareness to the kernel. 1266 1267 For 64-bit this is recommended if the system is Intel Core i7 1268 (or later), AMD Opteron, or EM64T NUMA. 1269 1270 For 32-bit this is only needed on (rare) 32-bit-only platforms 1271 that support NUMA topologies, such as NUMAQ / Summit, or if you 1272 boot a 32-bit kernel on a 64-bit NUMA platform. 1273 1274 Otherwise, you should say N. 1275 1276comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1277 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1278 1279config AMD_NUMA 1280 def_bool y 1281 prompt "Old style AMD Opteron NUMA detection" 1282 depends on X86_64 && NUMA && PCI 1283 ---help--- 1284 Enable AMD NUMA node topology detection. You should say Y here if 1285 you have a multi processor AMD system. This uses an old method to 1286 read the NUMA configuration directly from the builtin Northbridge 1287 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1288 which also takes priority if both are compiled in. 1289 1290config X86_64_ACPI_NUMA 1291 def_bool y 1292 prompt "ACPI NUMA detection" 1293 depends on X86_64 && NUMA && ACPI && PCI 1294 select ACPI_NUMA 1295 ---help--- 1296 Enable ACPI SRAT based node topology detection. 1297 1298# Some NUMA nodes have memory ranges that span 1299# other nodes. Even though a pfn is valid and 1300# between a node's start and end pfns, it may not 1301# reside on that node. See memmap_init_zone() 1302# for details. 1303config NODES_SPAN_OTHER_NODES 1304 def_bool y 1305 depends on X86_64_ACPI_NUMA 1306 1307config NUMA_EMU 1308 bool "NUMA emulation" 1309 depends on NUMA 1310 ---help--- 1311 Enable NUMA emulation. A flat machine will be split 1312 into virtual nodes when booted with "numa=fake=N", where N is the 1313 number of nodes. This is only useful for debugging. 1314 1315config NODES_SHIFT 1316 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1317 range 1 10 1318 default "10" if MAXSMP 1319 default "6" if X86_64 1320 default "4" if X86_NUMAQ 1321 default "3" 1322 depends on NEED_MULTIPLE_NODES 1323 ---help--- 1324 Specify the maximum number of NUMA Nodes available on the target 1325 system. Increases memory reserved to accommodate various tables. 1326 1327config ARCH_HAVE_MEMORY_PRESENT 1328 def_bool y 1329 depends on X86_32 && DISCONTIGMEM 1330 1331config NEED_NODE_MEMMAP_SIZE 1332 def_bool y 1333 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1334 1335config ARCH_FLATMEM_ENABLE 1336 def_bool y 1337 depends on X86_32 && !NUMA 1338 1339config ARCH_DISCONTIGMEM_ENABLE 1340 def_bool y 1341 depends on NUMA && X86_32 1342 1343config ARCH_DISCONTIGMEM_DEFAULT 1344 def_bool y 1345 depends on NUMA && X86_32 1346 1347config ARCH_SPARSEMEM_ENABLE 1348 def_bool y 1349 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1350 select SPARSEMEM_STATIC if X86_32 1351 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1352 1353config ARCH_SPARSEMEM_DEFAULT 1354 def_bool y 1355 depends on X86_64 1356 1357config ARCH_SELECT_MEMORY_MODEL 1358 def_bool y 1359 depends on ARCH_SPARSEMEM_ENABLE 1360 1361config ARCH_MEMORY_PROBE 1362 bool "Enable sysfs memory/probe interface" 1363 depends on X86_64 && MEMORY_HOTPLUG 1364 help 1365 This option enables a sysfs memory/probe interface for testing. 1366 See Documentation/memory-hotplug.txt for more information. 1367 If you are unsure how to answer this question, answer N. 1368 1369config ARCH_PROC_KCORE_TEXT 1370 def_bool y 1371 depends on X86_64 && PROC_KCORE 1372 1373config ILLEGAL_POINTER_VALUE 1374 hex 1375 default 0 if X86_32 1376 default 0xdead000000000000 if X86_64 1377 1378source "mm/Kconfig" 1379 1380config HIGHPTE 1381 bool "Allocate 3rd-level pagetables from highmem" 1382 depends on HIGHMEM 1383 ---help--- 1384 The VM uses one page table entry for each page of physical memory. 1385 For systems with a lot of RAM, this can be wasteful of precious 1386 low memory. Setting this option will put user-space page table 1387 entries in high memory. 1388 1389config X86_CHECK_BIOS_CORRUPTION 1390 bool "Check for low memory corruption" 1391 ---help--- 1392 Periodically check for memory corruption in low memory, which 1393 is suspected to be caused by BIOS. Even when enabled in the 1394 configuration, it is disabled at runtime. Enable it by 1395 setting "memory_corruption_check=1" on the kernel command 1396 line. By default it scans the low 64k of memory every 60 1397 seconds; see the memory_corruption_check_size and 1398 memory_corruption_check_period parameters in 1399 Documentation/kernel-parameters.txt to adjust this. 1400 1401 When enabled with the default parameters, this option has 1402 almost no overhead, as it reserves a relatively small amount 1403 of memory and scans it infrequently. It both detects corruption 1404 and prevents it from affecting the running system. 1405 1406 It is, however, intended as a diagnostic tool; if repeatable 1407 BIOS-originated corruption always affects the same memory, 1408 you can use memmap= to prevent the kernel from using that 1409 memory. 1410 1411config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1412 bool "Set the default setting of memory_corruption_check" 1413 depends on X86_CHECK_BIOS_CORRUPTION 1414 default y 1415 ---help--- 1416 Set whether the default state of memory_corruption_check is 1417 on or off. 1418 1419config X86_RESERVE_LOW 1420 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1421 default 64 1422 range 4 640 1423 ---help--- 1424 Specify the amount of low memory to reserve for the BIOS. 1425 1426 The first page contains BIOS data structures that the kernel 1427 must not use, so that page must always be reserved. 1428 1429 By default we reserve the first 64K of physical RAM, as a 1430 number of BIOSes are known to corrupt that memory range 1431 during events such as suspend/resume or monitor cable 1432 insertion, so it must not be used by the kernel. 1433 1434 You can set this to 4 if you are absolutely sure that you 1435 trust the BIOS to get all its memory reservations and usages 1436 right. If you know your BIOS have problems beyond the 1437 default 64K area, you can set this to 640 to avoid using the 1438 entire low memory range. 1439 1440 If you have doubts about the BIOS (e.g. suspend/resume does 1441 not work or there's kernel crashes after certain hardware 1442 hotplug events) then you might want to enable 1443 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1444 typical corruption patterns. 1445 1446 Leave this to the default value of 64 if you are unsure. 1447 1448config MATH_EMULATION 1449 bool 1450 prompt "Math emulation" if X86_32 1451 ---help--- 1452 Linux can emulate a math coprocessor (used for floating point 1453 operations) if you don't have one. 486DX and Pentium processors have 1454 a math coprocessor built in, 486SX and 386 do not, unless you added 1455 a 487DX or 387, respectively. (The messages during boot time can 1456 give you some hints here ["man dmesg"].) Everyone needs either a 1457 coprocessor or this emulation. 1458 1459 If you don't have a math coprocessor, you need to say Y here; if you 1460 say Y here even though you have a coprocessor, the coprocessor will 1461 be used nevertheless. (This behavior can be changed with the kernel 1462 command line option "no387", which comes handy if your coprocessor 1463 is broken. Try "man bootparam" or see the documentation of your boot 1464 loader (lilo or loadlin) about how to pass options to the kernel at 1465 boot time.) This means that it is a good idea to say Y here if you 1466 intend to use this kernel on different machines. 1467 1468 More information about the internals of the Linux math coprocessor 1469 emulation can be found in <file:arch/x86/math-emu/README>. 1470 1471 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1472 kernel, it won't hurt. 1473 1474config MTRR 1475 def_bool y 1476 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1477 ---help--- 1478 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1479 the Memory Type Range Registers (MTRRs) may be used to control 1480 processor access to memory ranges. This is most useful if you have 1481 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1482 allows bus write transfers to be combined into a larger transfer 1483 before bursting over the PCI/AGP bus. This can increase performance 1484 of image write operations 2.5 times or more. Saying Y here creates a 1485 /proc/mtrr file which may be used to manipulate your processor's 1486 MTRRs. Typically the X server should use this. 1487 1488 This code has a reasonably generic interface so that similar 1489 control registers on other processors can be easily supported 1490 as well: 1491 1492 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1493 Registers (ARRs) which provide a similar functionality to MTRRs. For 1494 these, the ARRs are used to emulate the MTRRs. 1495 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1496 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1497 write-combining. All of these processors are supported by this code 1498 and it makes sense to say Y here if you have one of them. 1499 1500 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1501 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1502 can lead to all sorts of problems, so it's good to say Y here. 1503 1504 You can safely say Y even if your machine doesn't have MTRRs, you'll 1505 just add about 9 KB to your kernel. 1506 1507 See <file:Documentation/x86/mtrr.txt> for more information. 1508 1509config MTRR_SANITIZER 1510 def_bool y 1511 prompt "MTRR cleanup support" 1512 depends on MTRR 1513 ---help--- 1514 Convert MTRR layout from continuous to discrete, so X drivers can 1515 add writeback entries. 1516 1517 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1518 The largest mtrr entry size for a continuous block can be set with 1519 mtrr_chunk_size. 1520 1521 If unsure, say Y. 1522 1523config MTRR_SANITIZER_ENABLE_DEFAULT 1524 int "MTRR cleanup enable value (0-1)" 1525 range 0 1 1526 default "0" 1527 depends on MTRR_SANITIZER 1528 ---help--- 1529 Enable mtrr cleanup default value 1530 1531config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1532 int "MTRR cleanup spare reg num (0-7)" 1533 range 0 7 1534 default "1" 1535 depends on MTRR_SANITIZER 1536 ---help--- 1537 mtrr cleanup spare entries default, it can be changed via 1538 mtrr_spare_reg_nr=N on the kernel command line. 1539 1540config X86_PAT 1541 def_bool y 1542 prompt "x86 PAT support" if EXPERT 1543 depends on MTRR 1544 ---help--- 1545 Use PAT attributes to setup page level cache control. 1546 1547 PATs are the modern equivalents of MTRRs and are much more 1548 flexible than MTRRs. 1549 1550 Say N here if you see bootup problems (boot crash, boot hang, 1551 spontaneous reboots) or a non-working video driver. 1552 1553 If unsure, say Y. 1554 1555config ARCH_USES_PG_UNCACHED 1556 def_bool y 1557 depends on X86_PAT 1558 1559config ARCH_RANDOM 1560 def_bool y 1561 prompt "x86 architectural random number generator" if EXPERT 1562 ---help--- 1563 Enable the x86 architectural RDRAND instruction 1564 (Intel Bull Mountain technology) to generate random numbers. 1565 If supported, this is a high bandwidth, cryptographically 1566 secure hardware random number generator. 1567 1568config X86_SMAP 1569 def_bool y 1570 prompt "Supervisor Mode Access Prevention" if EXPERT 1571 ---help--- 1572 Supervisor Mode Access Prevention (SMAP) is a security 1573 feature in newer Intel processors. There is a small 1574 performance cost if this enabled and turned on; there is 1575 also a small increase in the kernel size if this is enabled. 1576 1577 If unsure, say Y. 1578 1579config EFI 1580 bool "EFI runtime service support" 1581 depends on ACPI 1582 select UCS2_STRING 1583 ---help--- 1584 This enables the kernel to use EFI runtime services that are 1585 available (such as the EFI variable services). 1586 1587 This option is only useful on systems that have EFI firmware. 1588 In addition, you should use the latest ELILO loader available 1589 at <http://elilo.sourceforge.net> in order to take advantage 1590 of EFI runtime services. However, even with this option, the 1591 resultant kernel should continue to boot on existing non-EFI 1592 platforms. 1593 1594config EFI_STUB 1595 bool "EFI stub support" 1596 depends on EFI 1597 ---help--- 1598 This kernel feature allows a bzImage to be loaded directly 1599 by EFI firmware without the use of a bootloader. 1600 1601 See Documentation/efi-stub.txt for more information. 1602 1603config SECCOMP 1604 def_bool y 1605 prompt "Enable seccomp to safely compute untrusted bytecode" 1606 ---help--- 1607 This kernel feature is useful for number crunching applications 1608 that may need to compute untrusted bytecode during their 1609 execution. By using pipes or other transports made available to 1610 the process as file descriptors supporting the read/write 1611 syscalls, it's possible to isolate those applications in 1612 their own address space using seccomp. Once seccomp is 1613 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1614 and the task is only allowed to execute a few safe syscalls 1615 defined by each seccomp mode. 1616 1617 If unsure, say Y. Only embedded should say N here. 1618 1619config CC_STACKPROTECTOR 1620 bool "Enable -fstack-protector buffer overflow detection" 1621 ---help--- 1622 This option turns on the -fstack-protector GCC feature. This 1623 feature puts, at the beginning of functions, a canary value on 1624 the stack just before the return address, and validates 1625 the value just before actually returning. Stack based buffer 1626 overflows (that need to overwrite this return address) now also 1627 overwrite the canary, which gets detected and the attack is then 1628 neutralized via a kernel panic. 1629 1630 This feature requires gcc version 4.2 or above, or a distribution 1631 gcc with the feature backported. Older versions are automatically 1632 detected and for those versions, this configuration option is 1633 ignored. (and a warning is printed during bootup) 1634 1635source kernel/Kconfig.hz 1636 1637config KEXEC 1638 bool "kexec system call" 1639 ---help--- 1640 kexec is a system call that implements the ability to shutdown your 1641 current kernel, and to start another kernel. It is like a reboot 1642 but it is independent of the system firmware. And like a reboot 1643 you can start any kernel with it, not just Linux. 1644 1645 The name comes from the similarity to the exec system call. 1646 1647 It is an ongoing process to be certain the hardware in a machine 1648 is properly shutdown, so do not be surprised if this code does not 1649 initially work for you. As of this writing the exact hardware 1650 interface is strongly in flux, so no good recommendation can be 1651 made. 1652 1653config CRASH_DUMP 1654 bool "kernel crash dumps" 1655 depends on X86_64 || (X86_32 && HIGHMEM) 1656 ---help--- 1657 Generate crash dump after being started by kexec. 1658 This should be normally only set in special crash dump kernels 1659 which are loaded in the main kernel with kexec-tools into 1660 a specially reserved region and then later executed after 1661 a crash by kdump/kexec. The crash dump kernel must be compiled 1662 to a memory address not used by the main kernel or BIOS using 1663 PHYSICAL_START, or it must be built as a relocatable image 1664 (CONFIG_RELOCATABLE=y). 1665 For more details see Documentation/kdump/kdump.txt 1666 1667config KEXEC_JUMP 1668 bool "kexec jump" 1669 depends on KEXEC && HIBERNATION 1670 ---help--- 1671 Jump between original kernel and kexeced kernel and invoke 1672 code in physical address mode via KEXEC 1673 1674config PHYSICAL_START 1675 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1676 default "0x1000000" 1677 ---help--- 1678 This gives the physical address where the kernel is loaded. 1679 1680 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1681 bzImage will decompress itself to above physical address and 1682 run from there. Otherwise, bzImage will run from the address where 1683 it has been loaded by the boot loader and will ignore above physical 1684 address. 1685 1686 In normal kdump cases one does not have to set/change this option 1687 as now bzImage can be compiled as a completely relocatable image 1688 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1689 address. This option is mainly useful for the folks who don't want 1690 to use a bzImage for capturing the crash dump and want to use a 1691 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1692 to be specifically compiled to run from a specific memory area 1693 (normally a reserved region) and this option comes handy. 1694 1695 So if you are using bzImage for capturing the crash dump, 1696 leave the value here unchanged to 0x1000000 and set 1697 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1698 for capturing the crash dump change this value to start of 1699 the reserved region. In other words, it can be set based on 1700 the "X" value as specified in the "crashkernel=YM@XM" 1701 command line boot parameter passed to the panic-ed 1702 kernel. Please take a look at Documentation/kdump/kdump.txt 1703 for more details about crash dumps. 1704 1705 Usage of bzImage for capturing the crash dump is recommended as 1706 one does not have to build two kernels. Same kernel can be used 1707 as production kernel and capture kernel. Above option should have 1708 gone away after relocatable bzImage support is introduced. But it 1709 is present because there are users out there who continue to use 1710 vmlinux for dump capture. This option should go away down the 1711 line. 1712 1713 Don't change this unless you know what you are doing. 1714 1715config RELOCATABLE 1716 bool "Build a relocatable kernel" 1717 default y 1718 ---help--- 1719 This builds a kernel image that retains relocation information 1720 so it can be loaded someplace besides the default 1MB. 1721 The relocations tend to make the kernel binary about 10% larger, 1722 but are discarded at runtime. 1723 1724 One use is for the kexec on panic case where the recovery kernel 1725 must live at a different physical address than the primary 1726 kernel. 1727 1728 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1729 it has been loaded at and the compile time physical address 1730 (CONFIG_PHYSICAL_START) is ignored. 1731 1732# Relocation on x86-32 needs some additional build support 1733config X86_NEED_RELOCS 1734 def_bool y 1735 depends on X86_32 && RELOCATABLE 1736 1737config PHYSICAL_ALIGN 1738 hex "Alignment value to which kernel should be aligned" 1739 default "0x1000000" 1740 range 0x2000 0x1000000 if X86_32 1741 range 0x200000 0x1000000 if X86_64 1742 ---help--- 1743 This value puts the alignment restrictions on physical address 1744 where kernel is loaded and run from. Kernel is compiled for an 1745 address which meets above alignment restriction. 1746 1747 If bootloader loads the kernel at a non-aligned address and 1748 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1749 address aligned to above value and run from there. 1750 1751 If bootloader loads the kernel at a non-aligned address and 1752 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1753 load address and decompress itself to the address it has been 1754 compiled for and run from there. The address for which kernel is 1755 compiled already meets above alignment restrictions. Hence the 1756 end result is that kernel runs from a physical address meeting 1757 above alignment restrictions. 1758 1759 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1760 this value must be a multiple of 0x200000. 1761 1762 Don't change this unless you know what you are doing. 1763 1764config HOTPLUG_CPU 1765 bool "Support for hot-pluggable CPUs" 1766 depends on SMP 1767 ---help--- 1768 Say Y here to allow turning CPUs off and on. CPUs can be 1769 controlled through /sys/devices/system/cpu. 1770 ( Note: power management support will enable this option 1771 automatically on SMP systems. ) 1772 Say N if you want to disable CPU hotplug. 1773 1774config BOOTPARAM_HOTPLUG_CPU0 1775 bool "Set default setting of cpu0_hotpluggable" 1776 default n 1777 depends on HOTPLUG_CPU 1778 ---help--- 1779 Set whether default state of cpu0_hotpluggable is on or off. 1780 1781 Say Y here to enable CPU0 hotplug by default. If this switch 1782 is turned on, there is no need to give cpu0_hotplug kernel 1783 parameter and the CPU0 hotplug feature is enabled by default. 1784 1785 Please note: there are two known CPU0 dependencies if you want 1786 to enable the CPU0 hotplug feature either by this switch or by 1787 cpu0_hotplug kernel parameter. 1788 1789 First, resume from hibernate or suspend always starts from CPU0. 1790 So hibernate and suspend are prevented if CPU0 is offline. 1791 1792 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1793 offline if any interrupt can not migrate out of CPU0. There may 1794 be other CPU0 dependencies. 1795 1796 Please make sure the dependencies are under your control before 1797 you enable this feature. 1798 1799 Say N if you don't want to enable CPU0 hotplug feature by default. 1800 You still can enable the CPU0 hotplug feature at boot by kernel 1801 parameter cpu0_hotplug. 1802 1803config DEBUG_HOTPLUG_CPU0 1804 def_bool n 1805 prompt "Debug CPU0 hotplug" 1806 depends on HOTPLUG_CPU 1807 ---help--- 1808 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1809 soon as possible and boots up userspace with CPU0 offlined. User 1810 can online CPU0 back after boot time. 1811 1812 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1813 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1814 compilation or giving cpu0_hotplug kernel parameter at boot. 1815 1816 If unsure, say N. 1817 1818config COMPAT_VDSO 1819 def_bool y 1820 prompt "Compat VDSO support" 1821 depends on X86_32 || IA32_EMULATION 1822 ---help--- 1823 Map the 32-bit VDSO to the predictable old-style address too. 1824 1825 Say N here if you are running a sufficiently recent glibc 1826 version (2.3.3 or later), to remove the high-mapped 1827 VDSO mapping and to exclusively use the randomized VDSO. 1828 1829 If unsure, say Y. 1830 1831config CMDLINE_BOOL 1832 bool "Built-in kernel command line" 1833 ---help--- 1834 Allow for specifying boot arguments to the kernel at 1835 build time. On some systems (e.g. embedded ones), it is 1836 necessary or convenient to provide some or all of the 1837 kernel boot arguments with the kernel itself (that is, 1838 to not rely on the boot loader to provide them.) 1839 1840 To compile command line arguments into the kernel, 1841 set this option to 'Y', then fill in the 1842 the boot arguments in CONFIG_CMDLINE. 1843 1844 Systems with fully functional boot loaders (i.e. non-embedded) 1845 should leave this option set to 'N'. 1846 1847config CMDLINE 1848 string "Built-in kernel command string" 1849 depends on CMDLINE_BOOL 1850 default "" 1851 ---help--- 1852 Enter arguments here that should be compiled into the kernel 1853 image and used at boot time. If the boot loader provides a 1854 command line at boot time, it is appended to this string to 1855 form the full kernel command line, when the system boots. 1856 1857 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1858 change this behavior. 1859 1860 In most cases, the command line (whether built-in or provided 1861 by the boot loader) should specify the device for the root 1862 file system. 1863 1864config CMDLINE_OVERRIDE 1865 bool "Built-in command line overrides boot loader arguments" 1866 depends on CMDLINE_BOOL 1867 ---help--- 1868 Set this option to 'Y' to have the kernel ignore the boot loader 1869 command line, and use ONLY the built-in command line. 1870 1871 This is used to work around broken boot loaders. This should 1872 be set to 'N' under normal conditions. 1873 1874endmenu 1875 1876config ARCH_ENABLE_MEMORY_HOTPLUG 1877 def_bool y 1878 depends on X86_64 || (X86_32 && HIGHMEM) 1879 1880config ARCH_ENABLE_MEMORY_HOTREMOVE 1881 def_bool y 1882 depends on MEMORY_HOTPLUG 1883 1884config USE_PERCPU_NUMA_NODE_ID 1885 def_bool y 1886 depends on NUMA 1887 1888config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1889 def_bool y 1890 depends on X86_64 || X86_PAE 1891 1892menu "Power management and ACPI options" 1893 1894config ARCH_HIBERNATION_HEADER 1895 def_bool y 1896 depends on X86_64 && HIBERNATION 1897 1898source "kernel/power/Kconfig" 1899 1900source "drivers/acpi/Kconfig" 1901 1902source "drivers/sfi/Kconfig" 1903 1904config X86_APM_BOOT 1905 def_bool y 1906 depends on APM 1907 1908menuconfig APM 1909 tristate "APM (Advanced Power Management) BIOS support" 1910 depends on X86_32 && PM_SLEEP 1911 ---help--- 1912 APM is a BIOS specification for saving power using several different 1913 techniques. This is mostly useful for battery powered laptops with 1914 APM compliant BIOSes. If you say Y here, the system time will be 1915 reset after a RESUME operation, the /proc/apm device will provide 1916 battery status information, and user-space programs will receive 1917 notification of APM "events" (e.g. battery status change). 1918 1919 If you select "Y" here, you can disable actual use of the APM 1920 BIOS by passing the "apm=off" option to the kernel at boot time. 1921 1922 Note that the APM support is almost completely disabled for 1923 machines with more than one CPU. 1924 1925 In order to use APM, you will need supporting software. For location 1926 and more information, read <file:Documentation/power/apm-acpi.txt> 1927 and the Battery Powered Linux mini-HOWTO, available from 1928 <http://www.tldp.org/docs.html#howto>. 1929 1930 This driver does not spin down disk drives (see the hdparm(8) 1931 manpage ("man 8 hdparm") for that), and it doesn't turn off 1932 VESA-compliant "green" monitors. 1933 1934 This driver does not support the TI 4000M TravelMate and the ACER 1935 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1936 desktop machines also don't have compliant BIOSes, and this driver 1937 may cause those machines to panic during the boot phase. 1938 1939 Generally, if you don't have a battery in your machine, there isn't 1940 much point in using this driver and you should say N. If you get 1941 random kernel OOPSes or reboots that don't seem to be related to 1942 anything, try disabling/enabling this option (or disabling/enabling 1943 APM in your BIOS). 1944 1945 Some other things you should try when experiencing seemingly random, 1946 "weird" problems: 1947 1948 1) make sure that you have enough swap space and that it is 1949 enabled. 1950 2) pass the "no-hlt" option to the kernel 1951 3) switch on floating point emulation in the kernel and pass 1952 the "no387" option to the kernel 1953 4) pass the "floppy=nodma" option to the kernel 1954 5) pass the "mem=4M" option to the kernel (thereby disabling 1955 all but the first 4 MB of RAM) 1956 6) make sure that the CPU is not over clocked. 1957 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1958 8) disable the cache from your BIOS settings 1959 9) install a fan for the video card or exchange video RAM 1960 10) install a better fan for the CPU 1961 11) exchange RAM chips 1962 12) exchange the motherboard. 1963 1964 To compile this driver as a module, choose M here: the 1965 module will be called apm. 1966 1967if APM 1968 1969config APM_IGNORE_USER_SUSPEND 1970 bool "Ignore USER SUSPEND" 1971 ---help--- 1972 This option will ignore USER SUSPEND requests. On machines with a 1973 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1974 series notebooks, it is necessary to say Y because of a BIOS bug. 1975 1976config APM_DO_ENABLE 1977 bool "Enable PM at boot time" 1978 ---help--- 1979 Enable APM features at boot time. From page 36 of the APM BIOS 1980 specification: "When disabled, the APM BIOS does not automatically 1981 power manage devices, enter the Standby State, enter the Suspend 1982 State, or take power saving steps in response to CPU Idle calls." 1983 This driver will make CPU Idle calls when Linux is idle (unless this 1984 feature is turned off -- see "Do CPU IDLE calls", below). This 1985 should always save battery power, but more complicated APM features 1986 will be dependent on your BIOS implementation. You may need to turn 1987 this option off if your computer hangs at boot time when using APM 1988 support, or if it beeps continuously instead of suspending. Turn 1989 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1990 T400CDT. This is off by default since most machines do fine without 1991 this feature. 1992 1993config APM_CPU_IDLE 1994 depends on CPU_IDLE 1995 bool "Make CPU Idle calls when idle" 1996 ---help--- 1997 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1998 On some machines, this can activate improved power savings, such as 1999 a slowed CPU clock rate, when the machine is idle. These idle calls 2000 are made after the idle loop has run for some length of time (e.g., 2001 333 mS). On some machines, this will cause a hang at boot time or 2002 whenever the CPU becomes idle. (On machines with more than one CPU, 2003 this option does nothing.) 2004 2005config APM_DISPLAY_BLANK 2006 bool "Enable console blanking using APM" 2007 ---help--- 2008 Enable console blanking using the APM. Some laptops can use this to 2009 turn off the LCD backlight when the screen blanker of the Linux 2010 virtual console blanks the screen. Note that this is only used by 2011 the virtual console screen blanker, and won't turn off the backlight 2012 when using the X Window system. This also doesn't have anything to 2013 do with your VESA-compliant power-saving monitor. Further, this 2014 option doesn't work for all laptops -- it might not turn off your 2015 backlight at all, or it might print a lot of errors to the console, 2016 especially if you are using gpm. 2017 2018config APM_ALLOW_INTS 2019 bool "Allow interrupts during APM BIOS calls" 2020 ---help--- 2021 Normally we disable external interrupts while we are making calls to 2022 the APM BIOS as a measure to lessen the effects of a badly behaving 2023 BIOS implementation. The BIOS should reenable interrupts if it 2024 needs to. Unfortunately, some BIOSes do not -- especially those in 2025 many of the newer IBM Thinkpads. If you experience hangs when you 2026 suspend, try setting this to Y. Otherwise, say N. 2027 2028endif # APM 2029 2030source "drivers/cpufreq/Kconfig" 2031 2032source "drivers/cpuidle/Kconfig" 2033 2034source "drivers/idle/Kconfig" 2035 2036endmenu 2037 2038 2039menu "Bus options (PCI etc.)" 2040 2041config PCI 2042 bool "PCI support" 2043 default y 2044 ---help--- 2045 Find out whether you have a PCI motherboard. PCI is the name of a 2046 bus system, i.e. the way the CPU talks to the other stuff inside 2047 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2048 VESA. If you have PCI, say Y, otherwise N. 2049 2050choice 2051 prompt "PCI access mode" 2052 depends on X86_32 && PCI 2053 default PCI_GOANY 2054 ---help--- 2055 On PCI systems, the BIOS can be used to detect the PCI devices and 2056 determine their configuration. However, some old PCI motherboards 2057 have BIOS bugs and may crash if this is done. Also, some embedded 2058 PCI-based systems don't have any BIOS at all. Linux can also try to 2059 detect the PCI hardware directly without using the BIOS. 2060 2061 With this option, you can specify how Linux should detect the 2062 PCI devices. If you choose "BIOS", the BIOS will be used, 2063 if you choose "Direct", the BIOS won't be used, and if you 2064 choose "MMConfig", then PCI Express MMCONFIG will be used. 2065 If you choose "Any", the kernel will try MMCONFIG, then the 2066 direct access method and falls back to the BIOS if that doesn't 2067 work. If unsure, go with the default, which is "Any". 2068 2069config PCI_GOBIOS 2070 bool "BIOS" 2071 2072config PCI_GOMMCONFIG 2073 bool "MMConfig" 2074 2075config PCI_GODIRECT 2076 bool "Direct" 2077 2078config PCI_GOOLPC 2079 bool "OLPC XO-1" 2080 depends on OLPC 2081 2082config PCI_GOANY 2083 bool "Any" 2084 2085endchoice 2086 2087config PCI_BIOS 2088 def_bool y 2089 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2090 2091# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2092config PCI_DIRECT 2093 def_bool y 2094 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2095 2096config PCI_MMCONFIG 2097 def_bool y 2098 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2099 2100config PCI_OLPC 2101 def_bool y 2102 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2103 2104config PCI_XEN 2105 def_bool y 2106 depends on PCI && XEN 2107 select SWIOTLB_XEN 2108 2109config PCI_DOMAINS 2110 def_bool y 2111 depends on PCI 2112 2113config PCI_MMCONFIG 2114 bool "Support mmconfig PCI config space access" 2115 depends on X86_64 && PCI && ACPI 2116 2117config PCI_CNB20LE_QUIRK 2118 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2119 depends on PCI 2120 help 2121 Read the PCI windows out of the CNB20LE host bridge. This allows 2122 PCI hotplug to work on systems with the CNB20LE chipset which do 2123 not have ACPI. 2124 2125 There's no public spec for this chipset, and this functionality 2126 is known to be incomplete. 2127 2128 You should say N unless you know you need this. 2129 2130source "drivers/pci/pcie/Kconfig" 2131 2132source "drivers/pci/Kconfig" 2133 2134# x86_64 have no ISA slots, but can have ISA-style DMA. 2135config ISA_DMA_API 2136 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2137 default y 2138 help 2139 Enables ISA-style DMA support for devices requiring such controllers. 2140 If unsure, say Y. 2141 2142if X86_32 2143 2144config ISA 2145 bool "ISA support" 2146 ---help--- 2147 Find out whether you have ISA slots on your motherboard. ISA is the 2148 name of a bus system, i.e. the way the CPU talks to the other stuff 2149 inside your box. Other bus systems are PCI, EISA, MicroChannel 2150 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2151 newer boards don't support it. If you have ISA, say Y, otherwise N. 2152 2153config EISA 2154 bool "EISA support" 2155 depends on ISA 2156 ---help--- 2157 The Extended Industry Standard Architecture (EISA) bus was 2158 developed as an open alternative to the IBM MicroChannel bus. 2159 2160 The EISA bus provided some of the features of the IBM MicroChannel 2161 bus while maintaining backward compatibility with cards made for 2162 the older ISA bus. The EISA bus saw limited use between 1988 and 2163 1995 when it was made obsolete by the PCI bus. 2164 2165 Say Y here if you are building a kernel for an EISA-based machine. 2166 2167 Otherwise, say N. 2168 2169source "drivers/eisa/Kconfig" 2170 2171config SCx200 2172 tristate "NatSemi SCx200 support" 2173 ---help--- 2174 This provides basic support for National Semiconductor's 2175 (now AMD's) Geode processors. The driver probes for the 2176 PCI-IDs of several on-chip devices, so its a good dependency 2177 for other scx200_* drivers. 2178 2179 If compiled as a module, the driver is named scx200. 2180 2181config SCx200HR_TIMER 2182 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2183 depends on SCx200 2184 default y 2185 ---help--- 2186 This driver provides a clocksource built upon the on-chip 2187 27MHz high-resolution timer. Its also a workaround for 2188 NSC Geode SC-1100's buggy TSC, which loses time when the 2189 processor goes idle (as is done by the scheduler). The 2190 other workaround is idle=poll boot option. 2191 2192config OLPC 2193 bool "One Laptop Per Child support" 2194 depends on !X86_PAE 2195 select GPIOLIB 2196 select OF 2197 select OF_PROMTREE 2198 select IRQ_DOMAIN 2199 ---help--- 2200 Add support for detecting the unique features of the OLPC 2201 XO hardware. 2202 2203config OLPC_XO1_PM 2204 bool "OLPC XO-1 Power Management" 2205 depends on OLPC && MFD_CS5535 && PM_SLEEP 2206 select MFD_CORE 2207 ---help--- 2208 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2209 2210config OLPC_XO1_RTC 2211 bool "OLPC XO-1 Real Time Clock" 2212 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2213 ---help--- 2214 Add support for the XO-1 real time clock, which can be used as a 2215 programmable wakeup source. 2216 2217config OLPC_XO1_SCI 2218 bool "OLPC XO-1 SCI extras" 2219 depends on OLPC && OLPC_XO1_PM 2220 depends on INPUT=y 2221 select POWER_SUPPLY 2222 select GPIO_CS5535 2223 select MFD_CORE 2224 ---help--- 2225 Add support for SCI-based features of the OLPC XO-1 laptop: 2226 - EC-driven system wakeups 2227 - Power button 2228 - Ebook switch 2229 - Lid switch 2230 - AC adapter status updates 2231 - Battery status updates 2232 2233config OLPC_XO15_SCI 2234 bool "OLPC XO-1.5 SCI extras" 2235 depends on OLPC && ACPI 2236 select POWER_SUPPLY 2237 ---help--- 2238 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2239 - EC-driven system wakeups 2240 - AC adapter status updates 2241 - Battery status updates 2242 2243config ALIX 2244 bool "PCEngines ALIX System Support (LED setup)" 2245 select GPIOLIB 2246 ---help--- 2247 This option enables system support for the PCEngines ALIX. 2248 At present this just sets up LEDs for GPIO control on 2249 ALIX2/3/6 boards. However, other system specific setup should 2250 get added here. 2251 2252 Note: You must still enable the drivers for GPIO and LED support 2253 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2254 2255 Note: You have to set alix.force=1 for boards with Award BIOS. 2256 2257config NET5501 2258 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2259 select GPIOLIB 2260 ---help--- 2261 This option enables system support for the Soekris Engineering net5501. 2262 2263config GEOS 2264 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2265 select GPIOLIB 2266 depends on DMI 2267 ---help--- 2268 This option enables system support for the Traverse Technologies GEOS. 2269 2270config TS5500 2271 bool "Technologic Systems TS-5500 platform support" 2272 depends on MELAN 2273 select CHECK_SIGNATURE 2274 select NEW_LEDS 2275 select LEDS_CLASS 2276 ---help--- 2277 This option enables system support for the Technologic Systems TS-5500. 2278 2279endif # X86_32 2280 2281config AMD_NB 2282 def_bool y 2283 depends on CPU_SUP_AMD && PCI 2284 2285source "drivers/pcmcia/Kconfig" 2286 2287source "drivers/pci/hotplug/Kconfig" 2288 2289config RAPIDIO 2290 tristate "RapidIO support" 2291 depends on PCI 2292 default n 2293 help 2294 If enabled this option will include drivers and the core 2295 infrastructure code to support RapidIO interconnect devices. 2296 2297source "drivers/rapidio/Kconfig" 2298 2299config X86_SYSFB 2300 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2301 help 2302 Firmwares often provide initial graphics framebuffers so the BIOS, 2303 bootloader or kernel can show basic video-output during boot for 2304 user-guidance and debugging. Historically, x86 used the VESA BIOS 2305 Extensions and EFI-framebuffers for this, which are mostly limited 2306 to x86. 2307 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2308 framebuffers so the new generic system-framebuffer drivers can be 2309 used on x86. If the framebuffer is not compatible with the generic 2310 modes, it is adverticed as fallback platform framebuffer so legacy 2311 drivers like efifb, vesafb and uvesafb can pick it up. 2312 If this option is not selected, all system framebuffers are always 2313 marked as fallback platform framebuffers as usual. 2314 2315 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2316 not be able to pick up generic system framebuffers if this option 2317 is selected. You are highly encouraged to enable simplefb as 2318 replacement if you select this option. simplefb can correctly deal 2319 with generic system framebuffers. But you should still keep vesafb 2320 and others enabled as fallback if a system framebuffer is 2321 incompatible with simplefb. 2322 2323 If unsure, say Y. 2324 2325endmenu 2326 2327 2328menu "Executable file formats / Emulations" 2329 2330source "fs/Kconfig.binfmt" 2331 2332config IA32_EMULATION 2333 bool "IA32 Emulation" 2334 depends on X86_64 2335 select BINFMT_ELF 2336 select COMPAT_BINFMT_ELF 2337 select HAVE_UID16 2338 ---help--- 2339 Include code to run legacy 32-bit programs under a 2340 64-bit kernel. You should likely turn this on, unless you're 2341 100% sure that you don't have any 32-bit programs left. 2342 2343config IA32_AOUT 2344 tristate "IA32 a.out support" 2345 depends on IA32_EMULATION 2346 ---help--- 2347 Support old a.out binaries in the 32bit emulation. 2348 2349config X86_X32 2350 bool "x32 ABI for 64-bit mode" 2351 depends on X86_64 && IA32_EMULATION 2352 ---help--- 2353 Include code to run binaries for the x32 native 32-bit ABI 2354 for 64-bit processors. An x32 process gets access to the 2355 full 64-bit register file and wide data path while leaving 2356 pointers at 32 bits for smaller memory footprint. 2357 2358 You will need a recent binutils (2.22 or later) with 2359 elf32_x86_64 support enabled to compile a kernel with this 2360 option set. 2361 2362config COMPAT 2363 def_bool y 2364 depends on IA32_EMULATION || X86_X32 2365 select ARCH_WANT_OLD_COMPAT_IPC 2366 2367if COMPAT 2368config COMPAT_FOR_U64_ALIGNMENT 2369 def_bool y 2370 2371config SYSVIPC_COMPAT 2372 def_bool y 2373 depends on SYSVIPC 2374 2375config KEYS_COMPAT 2376 def_bool y 2377 depends on KEYS 2378endif 2379 2380endmenu 2381 2382 2383config HAVE_ATOMIC_IOMAP 2384 def_bool y 2385 depends on X86_32 2386 2387config X86_DEV_DMA_OPS 2388 bool 2389 depends on X86_64 || STA2X11 2390 2391config X86_DMA_REMAP 2392 bool 2393 depends on STA2X11 2394 2395source "net/Kconfig" 2396 2397source "drivers/Kconfig" 2398 2399source "drivers/firmware/Kconfig" 2400 2401source "fs/Kconfig" 2402 2403source "arch/x86/Kconfig.debug" 2404 2405source "security/Kconfig" 2406 2407source "crypto/Kconfig" 2408 2409source "arch/x86/kvm/Kconfig" 2410 2411source "lib/Kconfig" 2412