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_MIGHT_HAVE_PC_PARPORT 28 select ARCH_MIGHT_HAVE_PC_SERIO 29 select HAVE_AOUT if X86_32 30 select HAVE_UNSTABLE_SCHED_CLOCK 31 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 32 select ARCH_SUPPORTS_INT128 if X86_64 33 select ARCH_WANTS_PROT_NUMA_PROT_NONE 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 141config INSTRUCTION_DECODER 142 def_bool y 143 depends on KPROBES || PERF_EVENTS || UPROBES 144 145config OUTPUT_FORMAT 146 string 147 default "elf32-i386" if X86_32 148 default "elf64-x86-64" if X86_64 149 150config ARCH_DEFCONFIG 151 string 152 default "arch/x86/configs/i386_defconfig" if X86_32 153 default "arch/x86/configs/x86_64_defconfig" if X86_64 154 155config LOCKDEP_SUPPORT 156 def_bool y 157 158config STACKTRACE_SUPPORT 159 def_bool y 160 161config HAVE_LATENCYTOP_SUPPORT 162 def_bool y 163 164config MMU 165 def_bool y 166 167config SBUS 168 bool 169 170config NEED_DMA_MAP_STATE 171 def_bool y 172 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 173 174config NEED_SG_DMA_LENGTH 175 def_bool y 176 177config GENERIC_ISA_DMA 178 def_bool y 179 depends on ISA_DMA_API 180 181config GENERIC_BUG 182 def_bool y 183 depends on BUG 184 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 185 186config GENERIC_BUG_RELATIVE_POINTERS 187 bool 188 189config GENERIC_HWEIGHT 190 def_bool y 191 192config ARCH_MAY_HAVE_PC_FDC 193 def_bool y 194 depends on ISA_DMA_API 195 196config RWSEM_XCHGADD_ALGORITHM 197 def_bool y 198 199config GENERIC_CALIBRATE_DELAY 200 def_bool y 201 202config ARCH_HAS_CPU_RELAX 203 def_bool y 204 205config ARCH_HAS_CACHE_LINE_SIZE 206 def_bool y 207 208config HAVE_SETUP_PER_CPU_AREA 209 def_bool y 210 211config NEED_PER_CPU_EMBED_FIRST_CHUNK 212 def_bool y 213 214config NEED_PER_CPU_PAGE_FIRST_CHUNK 215 def_bool y 216 217config ARCH_HIBERNATION_POSSIBLE 218 def_bool y 219 220config ARCH_SUSPEND_POSSIBLE 221 def_bool y 222 223config ARCH_WANT_HUGE_PMD_SHARE 224 def_bool y 225 226config ARCH_WANT_GENERAL_HUGETLB 227 def_bool y 228 229config ZONE_DMA32 230 bool 231 default X86_64 232 233config AUDIT_ARCH 234 bool 235 default X86_64 236 237config ARCH_SUPPORTS_OPTIMIZED_INLINING 238 def_bool y 239 240config ARCH_SUPPORTS_DEBUG_PAGEALLOC 241 def_bool y 242 243config HAVE_INTEL_TXT 244 def_bool y 245 depends on INTEL_IOMMU && ACPI 246 247config X86_32_SMP 248 def_bool y 249 depends on X86_32 && SMP 250 251config X86_64_SMP 252 def_bool y 253 depends on X86_64 && SMP 254 255config X86_HT 256 def_bool y 257 depends on SMP 258 259config X86_32_LAZY_GS 260 def_bool y 261 depends on X86_32 && !CC_STACKPROTECTOR 262 263config ARCH_HWEIGHT_CFLAGS 264 string 265 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 266 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_64 267 268config ARCH_SUPPORTS_UPROBES 269 def_bool y 270 271config FIX_EARLYCON_MEM 272 def_bool y 273 274source "init/Kconfig" 275source "kernel/Kconfig.freezer" 276 277menu "Processor type and features" 278 279config ZONE_DMA 280 bool "DMA memory allocation support" if EXPERT 281 default y 282 help 283 DMA memory allocation support allows devices with less than 32-bit 284 addressing to allocate within the first 16MB of address space. 285 Disable if no such devices will be used. 286 287 If unsure, say Y. 288 289config SMP 290 bool "Symmetric multi-processing support" 291 ---help--- 292 This enables support for systems with more than one CPU. If you have 293 a system with only one CPU, say N. If you have a system with more 294 than one CPU, say Y. 295 296 If you say N here, the kernel will run on uni- and multiprocessor 297 machines, but will use only one CPU of a multiprocessor machine. If 298 you say Y here, the kernel will run on many, but not all, 299 uniprocessor machines. On a uniprocessor machine, the kernel 300 will run faster if you say N here. 301 302 Note that if you say Y here and choose architecture "586" or 303 "Pentium" under "Processor family", the kernel will not work on 486 304 architectures. Similarly, multiprocessor kernels for the "PPro" 305 architecture may not work on all Pentium based boards. 306 307 People using multiprocessor machines who say Y here should also say 308 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 309 Management" code will be disabled if you say Y here. 310 311 See also <file:Documentation/x86/i386/IO-APIC.txt>, 312 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 313 <http://www.tldp.org/docs.html#howto>. 314 315 If you don't know what to do here, say N. 316 317config X86_X2APIC 318 bool "Support x2apic" 319 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 320 ---help--- 321 This enables x2apic support on CPUs that have this feature. 322 323 This allows 32-bit apic IDs (so it can support very large systems), 324 and accesses the local apic via MSRs not via mmio. 325 326 If you don't know what to do here, say N. 327 328config X86_MPPARSE 329 bool "Enable MPS table" if ACPI || SFI 330 default y 331 depends on X86_LOCAL_APIC 332 ---help--- 333 For old smp systems that do not have proper acpi support. Newer systems 334 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 335 336config X86_BIGSMP 337 bool "Support for big SMP systems with more than 8 CPUs" 338 depends on X86_32 && SMP 339 ---help--- 340 This option is needed for the systems that have more than 8 CPUs 341 342config GOLDFISH 343 def_bool y 344 depends on X86_GOLDFISH 345 346if X86_32 347config X86_EXTENDED_PLATFORM 348 bool "Support for extended (non-PC) x86 platforms" 349 default y 350 ---help--- 351 If you disable this option then the kernel will only support 352 standard PC platforms. (which covers the vast majority of 353 systems out there.) 354 355 If you enable this option then you'll be able to select support 356 for the following (non-PC) 32 bit x86 platforms: 357 Goldfish (Android emulator) 358 AMD Elan 359 RDC R-321x SoC 360 SGI 320/540 (Visual Workstation) 361 STA2X11-based (e.g. Northville) 362 Moorestown MID devices 363 364 If you have one of these systems, or if you want to build a 365 generic distribution kernel, say Y here - otherwise say N. 366endif 367 368if X86_64 369config X86_EXTENDED_PLATFORM 370 bool "Support for extended (non-PC) x86 platforms" 371 default y 372 ---help--- 373 If you disable this option then the kernel will only support 374 standard PC platforms. (which covers the vast majority of 375 systems out there.) 376 377 If you enable this option then you'll be able to select support 378 for the following (non-PC) 64 bit x86 platforms: 379 Numascale NumaChip 380 ScaleMP vSMP 381 SGI Ultraviolet 382 383 If you have one of these systems, or if you want to build a 384 generic distribution kernel, say Y here - otherwise say N. 385endif 386# This is an alphabetically sorted list of 64 bit extended platforms 387# Please maintain the alphabetic order if and when there are additions 388config X86_NUMACHIP 389 bool "Numascale NumaChip" 390 depends on X86_64 391 depends on X86_EXTENDED_PLATFORM 392 depends on NUMA 393 depends on SMP 394 depends on X86_X2APIC 395 depends on PCI_MMCONFIG 396 ---help--- 397 Adds support for Numascale NumaChip large-SMP systems. Needed to 398 enable more than ~168 cores. 399 If you don't have one of these, you should say N here. 400 401config X86_VSMP 402 bool "ScaleMP vSMP" 403 select HYPERVISOR_GUEST 404 select PARAVIRT 405 depends on X86_64 && PCI 406 depends on X86_EXTENDED_PLATFORM 407 depends on SMP 408 ---help--- 409 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 410 supposed to run on these EM64T-based machines. Only choose this option 411 if you have one of these machines. 412 413config X86_UV 414 bool "SGI Ultraviolet" 415 depends on X86_64 416 depends on X86_EXTENDED_PLATFORM 417 depends on NUMA 418 depends on X86_X2APIC 419 ---help--- 420 This option is needed in order to support SGI Ultraviolet systems. 421 If you don't have one of these, you should say N here. 422 423# Following is an alphabetically sorted list of 32 bit extended platforms 424# Please maintain the alphabetic order if and when there are additions 425 426config X86_GOLDFISH 427 bool "Goldfish (Virtual Platform)" 428 depends on X86_EXTENDED_PLATFORM 429 ---help--- 430 Enable support for the Goldfish virtual platform used primarily 431 for Android development. Unless you are building for the Android 432 Goldfish emulator say N here. 433 434config X86_INTEL_CE 435 bool "CE4100 TV platform" 436 depends on PCI 437 depends on PCI_GODIRECT 438 depends on X86_IO_APIC 439 depends on X86_32 440 depends on X86_EXTENDED_PLATFORM 441 select X86_REBOOTFIXUPS 442 select OF 443 select OF_EARLY_FLATTREE 444 select IRQ_DOMAIN 445 ---help--- 446 Select for the Intel CE media processor (CE4100) SOC. 447 This option compiles in support for the CE4100 SOC for settop 448 boxes and media devices. 449 450config X86_INTEL_MID 451 bool "Intel MID platform support" 452 depends on X86_32 453 depends on X86_EXTENDED_PLATFORM 454 depends on X86_PLATFORM_DEVICES 455 depends on PCI 456 depends on PCI_GOANY 457 depends on X86_IO_APIC 458 select SFI 459 select I2C 460 select DW_APB_TIMER 461 select APB_TIMER 462 select INTEL_SCU_IPC 463 select MFD_INTEL_MSIC 464 ---help--- 465 Select to build a kernel capable of supporting Intel MID (Mobile 466 Internet Device) platform systems which do not have the PCI legacy 467 interfaces. If you are building for a PC class system say N here. 468 469 Intel MID platforms are based on an Intel processor and chipset which 470 consume less power than most of the x86 derivatives. 471 472config X86_INTEL_LPSS 473 bool "Intel Low Power Subsystem Support" 474 depends on ACPI 475 select COMMON_CLK 476 select PINCTRL 477 ---help--- 478 Select to build support for Intel Low Power Subsystem such as 479 found on Intel Lynxpoint PCH. Selecting this option enables 480 things like clock tree (common clock framework) and pincontrol 481 which are needed by the LPSS peripheral drivers. 482 483config X86_RDC321X 484 bool "RDC R-321x SoC" 485 depends on X86_32 486 depends on X86_EXTENDED_PLATFORM 487 select M486 488 select X86_REBOOTFIXUPS 489 ---help--- 490 This option is needed for RDC R-321x system-on-chip, also known 491 as R-8610-(G). 492 If you don't have one of these chips, you should say N here. 493 494config X86_32_NON_STANDARD 495 bool "Support non-standard 32-bit SMP architectures" 496 depends on X86_32 && SMP 497 depends on X86_EXTENDED_PLATFORM 498 ---help--- 499 This option compiles in the bigsmp and STA2X11 default 500 subarchitectures. It is intended for a generic binary 501 kernel. If you select them all, kernel will probe it one by 502 one and will fallback to default. 503 504# Alphabetically sorted list of Non standard 32 bit platforms 505 506config X86_SUPPORTS_MEMORY_FAILURE 507 def_bool y 508 # MCE code calls memory_failure(): 509 depends on X86_MCE 510 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 511 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 512 depends on X86_64 || !SPARSEMEM 513 select ARCH_SUPPORTS_MEMORY_FAILURE 514 515config STA2X11 516 bool "STA2X11 Companion Chip Support" 517 depends on X86_32_NON_STANDARD && PCI 518 select X86_DEV_DMA_OPS 519 select X86_DMA_REMAP 520 select SWIOTLB 521 select MFD_STA2X11 522 select ARCH_REQUIRE_GPIOLIB 523 default n 524 ---help--- 525 This adds support for boards based on the STA2X11 IO-Hub, 526 a.k.a. "ConneXt". The chip is used in place of the standard 527 PC chipset, so all "standard" peripherals are missing. If this 528 option is selected the kernel will still be able to boot on 529 standard PC machines. 530 531config X86_32_IRIS 532 tristate "Eurobraille/Iris poweroff module" 533 depends on X86_32 534 ---help--- 535 The Iris machines from EuroBraille do not have APM or ACPI support 536 to shut themselves down properly. A special I/O sequence is 537 needed to do so, which is what this module does at 538 kernel shutdown. 539 540 This is only for Iris machines from EuroBraille. 541 542 If unused, say N. 543 544config SCHED_OMIT_FRAME_POINTER 545 def_bool y 546 prompt "Single-depth WCHAN output" 547 depends on X86 548 ---help--- 549 Calculate simpler /proc/<PID>/wchan values. If this option 550 is disabled then wchan values will recurse back to the 551 caller function. This provides more accurate wchan values, 552 at the expense of slightly more scheduling overhead. 553 554 If in doubt, say "Y". 555 556menuconfig HYPERVISOR_GUEST 557 bool "Linux guest support" 558 ---help--- 559 Say Y here to enable options for running Linux under various hyper- 560 visors. This option enables basic hypervisor detection and platform 561 setup. 562 563 If you say N, all options in this submenu will be skipped and 564 disabled, and Linux guest support won't be built in. 565 566if HYPERVISOR_GUEST 567 568config PARAVIRT 569 bool "Enable paravirtualization code" 570 ---help--- 571 This changes the kernel so it can modify itself when it is run 572 under a hypervisor, potentially improving performance significantly 573 over full virtualization. However, when run without a hypervisor 574 the kernel is theoretically slower and slightly larger. 575 576config PARAVIRT_DEBUG 577 bool "paravirt-ops debugging" 578 depends on PARAVIRT && DEBUG_KERNEL 579 ---help--- 580 Enable to debug paravirt_ops internals. Specifically, BUG if 581 a paravirt_op is missing when it is called. 582 583config PARAVIRT_SPINLOCKS 584 bool "Paravirtualization layer for spinlocks" 585 depends on PARAVIRT && SMP 586 select UNINLINE_SPIN_UNLOCK 587 ---help--- 588 Paravirtualized spinlocks allow a pvops backend to replace the 589 spinlock implementation with something virtualization-friendly 590 (for example, block the virtual CPU rather than spinning). 591 592 It has a minimal impact on native kernels and gives a nice performance 593 benefit on paravirtualized KVM / Xen kernels. 594 595 If you are unsure how to answer this question, answer Y. 596 597source "arch/x86/xen/Kconfig" 598 599config KVM_GUEST 600 bool "KVM Guest support (including kvmclock)" 601 depends on PARAVIRT 602 select PARAVIRT_CLOCK 603 default y 604 ---help--- 605 This option enables various optimizations for running under the KVM 606 hypervisor. It includes a paravirtualized clock, so that instead 607 of relying on a PIT (or probably other) emulation by the 608 underlying device model, the host provides the guest with 609 timing infrastructure such as time of day, and system time 610 611config KVM_DEBUG_FS 612 bool "Enable debug information for KVM Guests in debugfs" 613 depends on KVM_GUEST && DEBUG_FS 614 default n 615 ---help--- 616 This option enables collection of various statistics for KVM guest. 617 Statistics are displayed in debugfs filesystem. Enabling this option 618 may incur significant overhead. 619 620source "arch/x86/lguest/Kconfig" 621 622config PARAVIRT_TIME_ACCOUNTING 623 bool "Paravirtual steal time accounting" 624 depends on PARAVIRT 625 default n 626 ---help--- 627 Select this option to enable fine granularity task steal time 628 accounting. Time spent executing other tasks in parallel with 629 the current vCPU is discounted from the vCPU power. To account for 630 that, there can be a small performance impact. 631 632 If in doubt, say N here. 633 634config PARAVIRT_CLOCK 635 bool 636 637endif #HYPERVISOR_GUEST 638 639config NO_BOOTMEM 640 def_bool y 641 642config MEMTEST 643 bool "Memtest" 644 ---help--- 645 This option adds a kernel parameter 'memtest', which allows memtest 646 to be set. 647 memtest=0, mean disabled; -- default 648 memtest=1, mean do 1 test pattern; 649 ... 650 memtest=4, mean do 4 test patterns. 651 If you are unsure how to answer this question, answer N. 652 653source "arch/x86/Kconfig.cpu" 654 655config HPET_TIMER 656 def_bool X86_64 657 prompt "HPET Timer Support" if X86_32 658 ---help--- 659 Use the IA-PC HPET (High Precision Event Timer) to manage 660 time in preference to the PIT and RTC, if a HPET is 661 present. 662 HPET is the next generation timer replacing legacy 8254s. 663 The HPET provides a stable time base on SMP 664 systems, unlike the TSC, but it is more expensive to access, 665 as it is off-chip. You can find the HPET spec at 666 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 667 668 You can safely choose Y here. However, HPET will only be 669 activated if the platform and the BIOS support this feature. 670 Otherwise the 8254 will be used for timing services. 671 672 Choose N to continue using the legacy 8254 timer. 673 674config HPET_EMULATE_RTC 675 def_bool y 676 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 677 678config APB_TIMER 679 def_bool y if X86_INTEL_MID 680 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 681 select DW_APB_TIMER 682 depends on X86_INTEL_MID && SFI 683 help 684 APB timer is the replacement for 8254, HPET on X86 MID platforms. 685 The APBT provides a stable time base on SMP 686 systems, unlike the TSC, but it is more expensive to access, 687 as it is off-chip. APB timers are always running regardless of CPU 688 C states, they are used as per CPU clockevent device when possible. 689 690# Mark as expert because too many people got it wrong. 691# The code disables itself when not needed. 692config DMI 693 default y 694 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 695 bool "Enable DMI scanning" if EXPERT 696 ---help--- 697 Enabled scanning of DMI to identify machine quirks. Say Y 698 here unless you have verified that your setup is not 699 affected by entries in the DMI blacklist. Required by PNP 700 BIOS code. 701 702config GART_IOMMU 703 bool "Old AMD GART IOMMU support" 704 select SWIOTLB 705 depends on X86_64 && PCI && AMD_NB 706 ---help--- 707 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 708 GART based hardware IOMMUs. 709 710 The GART supports full DMA access for devices with 32-bit access 711 limitations, on systems with more than 3 GB. This is usually needed 712 for USB, sound, many IDE/SATA chipsets and some other devices. 713 714 Newer systems typically have a modern AMD IOMMU, supported via 715 the CONFIG_AMD_IOMMU=y config option. 716 717 In normal configurations this driver is only active when needed: 718 there's more than 3 GB of memory and the system contains a 719 32-bit limited device. 720 721 If unsure, say Y. 722 723config CALGARY_IOMMU 724 bool "IBM Calgary IOMMU support" 725 select SWIOTLB 726 depends on X86_64 && PCI 727 ---help--- 728 Support for hardware IOMMUs in IBM's xSeries x366 and x460 729 systems. Needed to run systems with more than 3GB of memory 730 properly with 32-bit PCI devices that do not support DAC 731 (Double Address Cycle). Calgary also supports bus level 732 isolation, where all DMAs pass through the IOMMU. This 733 prevents them from going anywhere except their intended 734 destination. This catches hard-to-find kernel bugs and 735 mis-behaving drivers and devices that do not use the DMA-API 736 properly to set up their DMA buffers. The IOMMU can be 737 turned off at boot time with the iommu=off parameter. 738 Normally the kernel will make the right choice by itself. 739 If unsure, say Y. 740 741config CALGARY_IOMMU_ENABLED_BY_DEFAULT 742 def_bool y 743 prompt "Should Calgary be enabled by default?" 744 depends on CALGARY_IOMMU 745 ---help--- 746 Should Calgary be enabled by default? if you choose 'y', Calgary 747 will be used (if it exists). If you choose 'n', Calgary will not be 748 used even if it exists. If you choose 'n' and would like to use 749 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 750 If unsure, say Y. 751 752# need this always selected by IOMMU for the VIA workaround 753config SWIOTLB 754 def_bool y if X86_64 755 ---help--- 756 Support for software bounce buffers used on x86-64 systems 757 which don't have a hardware IOMMU. Using this PCI devices 758 which can only access 32-bits of memory can be used on systems 759 with more than 3 GB of memory. 760 If unsure, say Y. 761 762config IOMMU_HELPER 763 def_bool y 764 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 765 766config MAXSMP 767 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 768 depends on X86_64 && SMP && DEBUG_KERNEL 769 select CPUMASK_OFFSTACK 770 ---help--- 771 Enable maximum number of CPUS and NUMA Nodes for this architecture. 772 If unsure, say N. 773 774config NR_CPUS 775 int "Maximum number of CPUs" if SMP && !MAXSMP 776 range 2 8 if SMP && X86_32 && !X86_BIGSMP 777 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 778 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 779 default "1" if !SMP 780 default "8192" if MAXSMP 781 default "32" if SMP && X86_BIGSMP 782 default "8" if SMP 783 ---help--- 784 This allows you to specify the maximum number of CPUs which this 785 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 786 supported value is 4096, otherwise the maximum value is 512. The 787 minimum value which makes sense is 2. 788 789 This is purely to save memory - each supported CPU adds 790 approximately eight kilobytes to the kernel image. 791 792config SCHED_SMT 793 bool "SMT (Hyperthreading) scheduler support" 794 depends on X86_HT 795 ---help--- 796 SMT scheduler support improves the CPU scheduler's decision making 797 when dealing with Intel Pentium 4 chips with HyperThreading at a 798 cost of slightly increased overhead in some places. If unsure say 799 N here. 800 801config SCHED_MC 802 def_bool y 803 prompt "Multi-core scheduler support" 804 depends on X86_HT 805 ---help--- 806 Multi-core scheduler support improves the CPU scheduler's decision 807 making when dealing with multi-core CPU chips at a cost of slightly 808 increased overhead in some places. If unsure say N here. 809 810source "kernel/Kconfig.preempt" 811 812config X86_UP_APIC 813 bool "Local APIC support on uniprocessors" 814 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 815 ---help--- 816 A local APIC (Advanced Programmable Interrupt Controller) is an 817 integrated interrupt controller in the CPU. If you have a single-CPU 818 system which has a processor with a local APIC, you can say Y here to 819 enable and use it. If you say Y here even though your machine doesn't 820 have a local APIC, then the kernel will still run with no slowdown at 821 all. The local APIC supports CPU-generated self-interrupts (timer, 822 performance counters), and the NMI watchdog which detects hard 823 lockups. 824 825config X86_UP_IOAPIC 826 bool "IO-APIC support on uniprocessors" 827 depends on X86_UP_APIC 828 ---help--- 829 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 830 SMP-capable replacement for PC-style interrupt controllers. Most 831 SMP systems and many recent uniprocessor systems have one. 832 833 If you have a single-CPU system with an IO-APIC, you can say Y here 834 to use it. If you say Y here even though your machine doesn't have 835 an IO-APIC, then the kernel will still run with no slowdown at all. 836 837config X86_LOCAL_APIC 838 def_bool y 839 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 840 841config X86_IO_APIC 842 def_bool y 843 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 844 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ 845 select IRQ_DOMAIN 846 847config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 848 bool "Reroute for broken boot IRQs" 849 depends on X86_IO_APIC 850 ---help--- 851 This option enables a workaround that fixes a source of 852 spurious interrupts. This is recommended when threaded 853 interrupt handling is used on systems where the generation of 854 superfluous "boot interrupts" cannot be disabled. 855 856 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 857 entry in the chipset's IO-APIC is masked (as, e.g. the RT 858 kernel does during interrupt handling). On chipsets where this 859 boot IRQ generation cannot be disabled, this workaround keeps 860 the original IRQ line masked so that only the equivalent "boot 861 IRQ" is delivered to the CPUs. The workaround also tells the 862 kernel to set up the IRQ handler on the boot IRQ line. In this 863 way only one interrupt is delivered to the kernel. Otherwise 864 the spurious second interrupt may cause the kernel to bring 865 down (vital) interrupt lines. 866 867 Only affects "broken" chipsets. Interrupt sharing may be 868 increased on these systems. 869 870config X86_MCE 871 bool "Machine Check / overheating reporting" 872 default y 873 ---help--- 874 Machine Check support allows the processor to notify the 875 kernel if it detects a problem (e.g. overheating, data corruption). 876 The action the kernel takes depends on the severity of the problem, 877 ranging from warning messages to halting the machine. 878 879config X86_MCE_INTEL 880 def_bool y 881 prompt "Intel MCE features" 882 depends on X86_MCE && X86_LOCAL_APIC 883 ---help--- 884 Additional support for intel specific MCE features such as 885 the thermal monitor. 886 887config X86_MCE_AMD 888 def_bool y 889 prompt "AMD MCE features" 890 depends on X86_MCE && X86_LOCAL_APIC 891 ---help--- 892 Additional support for AMD specific MCE features such as 893 the DRAM Error Threshold. 894 895config X86_ANCIENT_MCE 896 bool "Support for old Pentium 5 / WinChip machine checks" 897 depends on X86_32 && X86_MCE 898 ---help--- 899 Include support for machine check handling on old Pentium 5 or WinChip 900 systems. These typically need to be enabled explicitly on the command 901 line. 902 903config X86_MCE_THRESHOLD 904 depends on X86_MCE_AMD || X86_MCE_INTEL 905 def_bool y 906 907config X86_MCE_INJECT 908 depends on X86_MCE 909 tristate "Machine check injector support" 910 ---help--- 911 Provide support for injecting machine checks for testing purposes. 912 If you don't know what a machine check is and you don't do kernel 913 QA it is safe to say n. 914 915config X86_THERMAL_VECTOR 916 def_bool y 917 depends on X86_MCE_INTEL 918 919config VM86 920 bool "Enable VM86 support" if EXPERT 921 default y 922 depends on X86_32 923 ---help--- 924 This option is required by programs like DOSEMU to run 925 16-bit real mode legacy code on x86 processors. It also may 926 be needed by software like XFree86 to initialize some video 927 cards via BIOS. Disabling this option saves about 6K. 928 929config X86_16BIT 930 bool "Enable support for 16-bit segments" if EXPERT 931 default y 932 ---help--- 933 This option is required by programs like Wine to run 16-bit 934 protected mode legacy code on x86 processors. Disabling 935 this option saves about 300 bytes on i386, or around 6K text 936 plus 16K runtime memory on x86-64, 937 938config X86_ESPFIX32 939 def_bool y 940 depends on X86_16BIT && X86_32 941 942config X86_ESPFIX64 943 def_bool y 944 depends on X86_16BIT && X86_64 945 946config TOSHIBA 947 tristate "Toshiba Laptop support" 948 depends on X86_32 949 ---help--- 950 This adds a driver to safely access the System Management Mode of 951 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 952 not work on models with a Phoenix BIOS. The System Management Mode 953 is used to set the BIOS and power saving options on Toshiba portables. 954 955 For information on utilities to make use of this driver see the 956 Toshiba Linux utilities web site at: 957 <http://www.buzzard.org.uk/toshiba/>. 958 959 Say Y if you intend to run this kernel on a Toshiba portable. 960 Say N otherwise. 961 962config I8K 963 tristate "Dell laptop support" 964 select HWMON 965 ---help--- 966 This adds a driver to safely access the System Management Mode 967 of the CPU on the Dell Inspiron 8000. The System Management Mode 968 is used to read cpu temperature and cooling fan status and to 969 control the fans on the I8K portables. 970 971 This driver has been tested only on the Inspiron 8000 but it may 972 also work with other Dell laptops. You can force loading on other 973 models by passing the parameter `force=1' to the module. Use at 974 your own risk. 975 976 For information on utilities to make use of this driver see the 977 I8K Linux utilities web site at: 978 <http://people.debian.org/~dz/i8k/> 979 980 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 981 Say N otherwise. 982 983config X86_REBOOTFIXUPS 984 bool "Enable X86 board specific fixups for reboot" 985 depends on X86_32 986 ---help--- 987 This enables chipset and/or board specific fixups to be done 988 in order to get reboot to work correctly. This is only needed on 989 some combinations of hardware and BIOS. The symptom, for which 990 this config is intended, is when reboot ends with a stalled/hung 991 system. 992 993 Currently, the only fixup is for the Geode machines using 994 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 995 996 Say Y if you want to enable the fixup. Currently, it's safe to 997 enable this option even if you don't need it. 998 Say N otherwise. 999 1000config MICROCODE 1001 tristate "CPU microcode loading support" 1002 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1003 select FW_LOADER 1004 ---help--- 1005 1006 If you say Y here, you will be able to update the microcode on 1007 certain Intel and AMD processors. The Intel support is for the 1008 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1009 Xeon etc. The AMD support is for families 0x10 and later. You will 1010 obviously need the actual microcode binary data itself which is not 1011 shipped with the Linux kernel. 1012 1013 This option selects the general module only, you need to select 1014 at least one vendor specific module as well. 1015 1016 To compile this driver as a module, choose M here: the module 1017 will be called microcode. 1018 1019config MICROCODE_INTEL 1020 bool "Intel microcode loading support" 1021 depends on MICROCODE 1022 default MICROCODE 1023 select FW_LOADER 1024 ---help--- 1025 This options enables microcode patch loading support for Intel 1026 processors. 1027 1028 For the current Intel microcode data package go to 1029 <https://downloadcenter.intel.com> and search for 1030 'Linux Processor Microcode Data File'. 1031 1032config MICROCODE_AMD 1033 bool "AMD microcode loading support" 1034 depends on MICROCODE 1035 select FW_LOADER 1036 ---help--- 1037 If you select this option, microcode patch loading support for AMD 1038 processors will be enabled. 1039 1040config MICROCODE_OLD_INTERFACE 1041 def_bool y 1042 depends on MICROCODE 1043 1044config MICROCODE_INTEL_EARLY 1045 def_bool n 1046 1047config MICROCODE_AMD_EARLY 1048 def_bool n 1049 1050config MICROCODE_EARLY 1051 bool "Early load microcode" 1052 depends on MICROCODE=y && BLK_DEV_INITRD 1053 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1054 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1055 default y 1056 help 1057 This option provides functionality to read additional microcode data 1058 at the beginning of initrd image. The data tells kernel to load 1059 microcode to CPU's as early as possible. No functional change if no 1060 microcode data is glued to the initrd, therefore it's safe to say Y. 1061 1062config X86_MSR 1063 tristate "/dev/cpu/*/msr - Model-specific register support" 1064 ---help--- 1065 This device gives privileged processes access to the x86 1066 Model-Specific Registers (MSRs). It is a character device with 1067 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1068 MSR accesses are directed to a specific CPU on multi-processor 1069 systems. 1070 1071config X86_CPUID 1072 tristate "/dev/cpu/*/cpuid - CPU information support" 1073 ---help--- 1074 This device gives processes access to the x86 CPUID instruction to 1075 be executed on a specific processor. It is a character device 1076 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1077 /dev/cpu/31/cpuid. 1078 1079choice 1080 prompt "High Memory Support" 1081 default HIGHMEM4G 1082 depends on X86_32 1083 1084config NOHIGHMEM 1085 bool "off" 1086 ---help--- 1087 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1088 However, the address space of 32-bit x86 processors is only 4 1089 Gigabytes large. That means that, if you have a large amount of 1090 physical memory, not all of it can be "permanently mapped" by the 1091 kernel. The physical memory that's not permanently mapped is called 1092 "high memory". 1093 1094 If you are compiling a kernel which will never run on a machine with 1095 more than 1 Gigabyte total physical RAM, answer "off" here (default 1096 choice and suitable for most users). This will result in a "3GB/1GB" 1097 split: 3GB are mapped so that each process sees a 3GB virtual memory 1098 space and the remaining part of the 4GB virtual memory space is used 1099 by the kernel to permanently map as much physical memory as 1100 possible. 1101 1102 If the machine has between 1 and 4 Gigabytes physical RAM, then 1103 answer "4GB" here. 1104 1105 If more than 4 Gigabytes is used then answer "64GB" here. This 1106 selection turns Intel PAE (Physical Address Extension) mode on. 1107 PAE implements 3-level paging on IA32 processors. PAE is fully 1108 supported by Linux, PAE mode is implemented on all recent Intel 1109 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1110 then the kernel will not boot on CPUs that don't support PAE! 1111 1112 The actual amount of total physical memory will either be 1113 auto detected or can be forced by using a kernel command line option 1114 such as "mem=256M". (Try "man bootparam" or see the documentation of 1115 your boot loader (lilo or loadlin) about how to pass options to the 1116 kernel at boot time.) 1117 1118 If unsure, say "off". 1119 1120config HIGHMEM4G 1121 bool "4GB" 1122 ---help--- 1123 Select this if you have a 32-bit processor and between 1 and 4 1124 gigabytes of physical RAM. 1125 1126config HIGHMEM64G 1127 bool "64GB" 1128 depends on !M486 1129 select X86_PAE 1130 ---help--- 1131 Select this if you have a 32-bit processor and more than 4 1132 gigabytes of physical RAM. 1133 1134endchoice 1135 1136choice 1137 prompt "Memory split" if EXPERT 1138 default VMSPLIT_3G 1139 depends on X86_32 1140 ---help--- 1141 Select the desired split between kernel and user memory. 1142 1143 If the address range available to the kernel is less than the 1144 physical memory installed, the remaining memory will be available 1145 as "high memory". Accessing high memory is a little more costly 1146 than low memory, as it needs to be mapped into the kernel first. 1147 Note that increasing the kernel address space limits the range 1148 available to user programs, making the address space there 1149 tighter. Selecting anything other than the default 3G/1G split 1150 will also likely make your kernel incompatible with binary-only 1151 kernel modules. 1152 1153 If you are not absolutely sure what you are doing, leave this 1154 option alone! 1155 1156 config VMSPLIT_3G 1157 bool "3G/1G user/kernel split" 1158 config VMSPLIT_3G_OPT 1159 depends on !X86_PAE 1160 bool "3G/1G user/kernel split (for full 1G low memory)" 1161 config VMSPLIT_2G 1162 bool "2G/2G user/kernel split" 1163 config VMSPLIT_2G_OPT 1164 depends on !X86_PAE 1165 bool "2G/2G user/kernel split (for full 2G low memory)" 1166 config VMSPLIT_1G 1167 bool "1G/3G user/kernel split" 1168endchoice 1169 1170config PAGE_OFFSET 1171 hex 1172 default 0xB0000000 if VMSPLIT_3G_OPT 1173 default 0x80000000 if VMSPLIT_2G 1174 default 0x78000000 if VMSPLIT_2G_OPT 1175 default 0x40000000 if VMSPLIT_1G 1176 default 0xC0000000 1177 depends on X86_32 1178 1179config HIGHMEM 1180 def_bool y 1181 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1182 1183config X86_PAE 1184 bool "PAE (Physical Address Extension) Support" 1185 depends on X86_32 && !HIGHMEM4G 1186 ---help--- 1187 PAE is required for NX support, and furthermore enables 1188 larger swapspace support for non-overcommit purposes. It 1189 has the cost of more pagetable lookup overhead, and also 1190 consumes more pagetable space per process. 1191 1192config ARCH_PHYS_ADDR_T_64BIT 1193 def_bool y 1194 depends on X86_64 || X86_PAE 1195 1196config ARCH_DMA_ADDR_T_64BIT 1197 def_bool y 1198 depends on X86_64 || HIGHMEM64G 1199 1200config DIRECT_GBPAGES 1201 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1202 default y 1203 depends on X86_64 1204 ---help--- 1205 Allow the kernel linear mapping to use 1GB pages on CPUs that 1206 support it. This can improve the kernel's performance a tiny bit by 1207 reducing TLB pressure. If in doubt, say "Y". 1208 1209# Common NUMA Features 1210config NUMA 1211 bool "Numa Memory Allocation and Scheduler Support" 1212 depends on SMP 1213 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1214 default y if X86_BIGSMP 1215 ---help--- 1216 Enable NUMA (Non Uniform Memory Access) support. 1217 1218 The kernel will try to allocate memory used by a CPU on the 1219 local memory controller of the CPU and add some more 1220 NUMA awareness to the kernel. 1221 1222 For 64-bit this is recommended if the system is Intel Core i7 1223 (or later), AMD Opteron, or EM64T NUMA. 1224 1225 For 32-bit this is only needed if you boot a 32-bit 1226 kernel on a 64-bit NUMA platform. 1227 1228 Otherwise, you should say N. 1229 1230config AMD_NUMA 1231 def_bool y 1232 prompt "Old style AMD Opteron NUMA detection" 1233 depends on X86_64 && NUMA && PCI 1234 ---help--- 1235 Enable AMD NUMA node topology detection. You should say Y here if 1236 you have a multi processor AMD system. This uses an old method to 1237 read the NUMA configuration directly from the builtin Northbridge 1238 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1239 which also takes priority if both are compiled in. 1240 1241config X86_64_ACPI_NUMA 1242 def_bool y 1243 prompt "ACPI NUMA detection" 1244 depends on X86_64 && NUMA && ACPI && PCI 1245 select ACPI_NUMA 1246 ---help--- 1247 Enable ACPI SRAT based node topology detection. 1248 1249# Some NUMA nodes have memory ranges that span 1250# other nodes. Even though a pfn is valid and 1251# between a node's start and end pfns, it may not 1252# reside on that node. See memmap_init_zone() 1253# for details. 1254config NODES_SPAN_OTHER_NODES 1255 def_bool y 1256 depends on X86_64_ACPI_NUMA 1257 1258config NUMA_EMU 1259 bool "NUMA emulation" 1260 depends on NUMA 1261 ---help--- 1262 Enable NUMA emulation. A flat machine will be split 1263 into virtual nodes when booted with "numa=fake=N", where N is the 1264 number of nodes. This is only useful for debugging. 1265 1266config NODES_SHIFT 1267 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1268 range 1 10 1269 default "10" if MAXSMP 1270 default "6" if X86_64 1271 default "3" 1272 depends on NEED_MULTIPLE_NODES 1273 ---help--- 1274 Specify the maximum number of NUMA Nodes available on the target 1275 system. Increases memory reserved to accommodate various tables. 1276 1277config ARCH_HAVE_MEMORY_PRESENT 1278 def_bool y 1279 depends on X86_32 && DISCONTIGMEM 1280 1281config NEED_NODE_MEMMAP_SIZE 1282 def_bool y 1283 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1284 1285config ARCH_FLATMEM_ENABLE 1286 def_bool y 1287 depends on X86_32 && !NUMA 1288 1289config ARCH_DISCONTIGMEM_ENABLE 1290 def_bool y 1291 depends on NUMA && X86_32 1292 1293config ARCH_DISCONTIGMEM_DEFAULT 1294 def_bool y 1295 depends on NUMA && X86_32 1296 1297config ARCH_SPARSEMEM_ENABLE 1298 def_bool y 1299 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1300 select SPARSEMEM_STATIC if X86_32 1301 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1302 1303config ARCH_SPARSEMEM_DEFAULT 1304 def_bool y 1305 depends on X86_64 1306 1307config ARCH_SELECT_MEMORY_MODEL 1308 def_bool y 1309 depends on ARCH_SPARSEMEM_ENABLE 1310 1311config ARCH_MEMORY_PROBE 1312 bool "Enable sysfs memory/probe interface" 1313 depends on X86_64 && MEMORY_HOTPLUG 1314 help 1315 This option enables a sysfs memory/probe interface for testing. 1316 See Documentation/memory-hotplug.txt for more information. 1317 If you are unsure how to answer this question, answer N. 1318 1319config ARCH_PROC_KCORE_TEXT 1320 def_bool y 1321 depends on X86_64 && PROC_KCORE 1322 1323config ILLEGAL_POINTER_VALUE 1324 hex 1325 default 0 if X86_32 1326 default 0xdead000000000000 if X86_64 1327 1328source "mm/Kconfig" 1329 1330config HIGHPTE 1331 bool "Allocate 3rd-level pagetables from highmem" 1332 depends on HIGHMEM 1333 ---help--- 1334 The VM uses one page table entry for each page of physical memory. 1335 For systems with a lot of RAM, this can be wasteful of precious 1336 low memory. Setting this option will put user-space page table 1337 entries in high memory. 1338 1339config X86_CHECK_BIOS_CORRUPTION 1340 bool "Check for low memory corruption" 1341 ---help--- 1342 Periodically check for memory corruption in low memory, which 1343 is suspected to be caused by BIOS. Even when enabled in the 1344 configuration, it is disabled at runtime. Enable it by 1345 setting "memory_corruption_check=1" on the kernel command 1346 line. By default it scans the low 64k of memory every 60 1347 seconds; see the memory_corruption_check_size and 1348 memory_corruption_check_period parameters in 1349 Documentation/kernel-parameters.txt to adjust this. 1350 1351 When enabled with the default parameters, this option has 1352 almost no overhead, as it reserves a relatively small amount 1353 of memory and scans it infrequently. It both detects corruption 1354 and prevents it from affecting the running system. 1355 1356 It is, however, intended as a diagnostic tool; if repeatable 1357 BIOS-originated corruption always affects the same memory, 1358 you can use memmap= to prevent the kernel from using that 1359 memory. 1360 1361config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1362 bool "Set the default setting of memory_corruption_check" 1363 depends on X86_CHECK_BIOS_CORRUPTION 1364 default y 1365 ---help--- 1366 Set whether the default state of memory_corruption_check is 1367 on or off. 1368 1369config X86_RESERVE_LOW 1370 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1371 default 64 1372 range 4 640 1373 ---help--- 1374 Specify the amount of low memory to reserve for the BIOS. 1375 1376 The first page contains BIOS data structures that the kernel 1377 must not use, so that page must always be reserved. 1378 1379 By default we reserve the first 64K of physical RAM, as a 1380 number of BIOSes are known to corrupt that memory range 1381 during events such as suspend/resume or monitor cable 1382 insertion, so it must not be used by the kernel. 1383 1384 You can set this to 4 if you are absolutely sure that you 1385 trust the BIOS to get all its memory reservations and usages 1386 right. If you know your BIOS have problems beyond the 1387 default 64K area, you can set this to 640 to avoid using the 1388 entire low memory range. 1389 1390 If you have doubts about the BIOS (e.g. suspend/resume does 1391 not work or there's kernel crashes after certain hardware 1392 hotplug events) then you might want to enable 1393 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1394 typical corruption patterns. 1395 1396 Leave this to the default value of 64 if you are unsure. 1397 1398config MATH_EMULATION 1399 bool 1400 prompt "Math emulation" if X86_32 1401 ---help--- 1402 Linux can emulate a math coprocessor (used for floating point 1403 operations) if you don't have one. 486DX and Pentium processors have 1404 a math coprocessor built in, 486SX and 386 do not, unless you added 1405 a 487DX or 387, respectively. (The messages during boot time can 1406 give you some hints here ["man dmesg"].) Everyone needs either a 1407 coprocessor or this emulation. 1408 1409 If you don't have a math coprocessor, you need to say Y here; if you 1410 say Y here even though you have a coprocessor, the coprocessor will 1411 be used nevertheless. (This behavior can be changed with the kernel 1412 command line option "no387", which comes handy if your coprocessor 1413 is broken. Try "man bootparam" or see the documentation of your boot 1414 loader (lilo or loadlin) about how to pass options to the kernel at 1415 boot time.) This means that it is a good idea to say Y here if you 1416 intend to use this kernel on different machines. 1417 1418 More information about the internals of the Linux math coprocessor 1419 emulation can be found in <file:arch/x86/math-emu/README>. 1420 1421 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1422 kernel, it won't hurt. 1423 1424config MTRR 1425 def_bool y 1426 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1427 ---help--- 1428 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1429 the Memory Type Range Registers (MTRRs) may be used to control 1430 processor access to memory ranges. This is most useful if you have 1431 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1432 allows bus write transfers to be combined into a larger transfer 1433 before bursting over the PCI/AGP bus. This can increase performance 1434 of image write operations 2.5 times or more. Saying Y here creates a 1435 /proc/mtrr file which may be used to manipulate your processor's 1436 MTRRs. Typically the X server should use this. 1437 1438 This code has a reasonably generic interface so that similar 1439 control registers on other processors can be easily supported 1440 as well: 1441 1442 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1443 Registers (ARRs) which provide a similar functionality to MTRRs. For 1444 these, the ARRs are used to emulate the MTRRs. 1445 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1446 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1447 write-combining. All of these processors are supported by this code 1448 and it makes sense to say Y here if you have one of them. 1449 1450 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1451 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1452 can lead to all sorts of problems, so it's good to say Y here. 1453 1454 You can safely say Y even if your machine doesn't have MTRRs, you'll 1455 just add about 9 KB to your kernel. 1456 1457 See <file:Documentation/x86/mtrr.txt> for more information. 1458 1459config MTRR_SANITIZER 1460 def_bool y 1461 prompt "MTRR cleanup support" 1462 depends on MTRR 1463 ---help--- 1464 Convert MTRR layout from continuous to discrete, so X drivers can 1465 add writeback entries. 1466 1467 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1468 The largest mtrr entry size for a continuous block can be set with 1469 mtrr_chunk_size. 1470 1471 If unsure, say Y. 1472 1473config MTRR_SANITIZER_ENABLE_DEFAULT 1474 int "MTRR cleanup enable value (0-1)" 1475 range 0 1 1476 default "0" 1477 depends on MTRR_SANITIZER 1478 ---help--- 1479 Enable mtrr cleanup default value 1480 1481config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1482 int "MTRR cleanup spare reg num (0-7)" 1483 range 0 7 1484 default "1" 1485 depends on MTRR_SANITIZER 1486 ---help--- 1487 mtrr cleanup spare entries default, it can be changed via 1488 mtrr_spare_reg_nr=N on the kernel command line. 1489 1490config X86_PAT 1491 def_bool y 1492 prompt "x86 PAT support" if EXPERT 1493 depends on MTRR 1494 ---help--- 1495 Use PAT attributes to setup page level cache control. 1496 1497 PATs are the modern equivalents of MTRRs and are much more 1498 flexible than MTRRs. 1499 1500 Say N here if you see bootup problems (boot crash, boot hang, 1501 spontaneous reboots) or a non-working video driver. 1502 1503 If unsure, say Y. 1504 1505config ARCH_USES_PG_UNCACHED 1506 def_bool y 1507 depends on X86_PAT 1508 1509config ARCH_RANDOM 1510 def_bool y 1511 prompt "x86 architectural random number generator" if EXPERT 1512 ---help--- 1513 Enable the x86 architectural RDRAND instruction 1514 (Intel Bull Mountain technology) to generate random numbers. 1515 If supported, this is a high bandwidth, cryptographically 1516 secure hardware random number generator. 1517 1518config X86_SMAP 1519 def_bool y 1520 prompt "Supervisor Mode Access Prevention" if EXPERT 1521 ---help--- 1522 Supervisor Mode Access Prevention (SMAP) is a security 1523 feature in newer Intel processors. There is a small 1524 performance cost if this enabled and turned on; there is 1525 also a small increase in the kernel size if this is enabled. 1526 1527 If unsure, say Y. 1528 1529config EFI 1530 bool "EFI runtime service support" 1531 depends on ACPI 1532 select UCS2_STRING 1533 select EFI_RUNTIME_WRAPPERS 1534 ---help--- 1535 This enables the kernel to use EFI runtime services that are 1536 available (such as the EFI variable services). 1537 1538 This option is only useful on systems that have EFI firmware. 1539 In addition, you should use the latest ELILO loader available 1540 at <http://elilo.sourceforge.net> in order to take advantage 1541 of EFI runtime services. However, even with this option, the 1542 resultant kernel should continue to boot on existing non-EFI 1543 platforms. 1544 1545config EFI_STUB 1546 bool "EFI stub support" 1547 depends on EFI && !X86_USE_3DNOW 1548 select RELOCATABLE 1549 ---help--- 1550 This kernel feature allows a bzImage to be loaded directly 1551 by EFI firmware without the use of a bootloader. 1552 1553 See Documentation/efi-stub.txt for more information. 1554 1555config EFI_MIXED 1556 bool "EFI mixed-mode support" 1557 depends on EFI_STUB && X86_64 1558 ---help--- 1559 Enabling this feature allows a 64-bit kernel to be booted 1560 on a 32-bit firmware, provided that your CPU supports 64-bit 1561 mode. 1562 1563 Note that it is not possible to boot a mixed-mode enabled 1564 kernel via the EFI boot stub - a bootloader that supports 1565 the EFI handover protocol must be used. 1566 1567 If unsure, say N. 1568 1569config SECCOMP 1570 def_bool y 1571 prompt "Enable seccomp to safely compute untrusted bytecode" 1572 ---help--- 1573 This kernel feature is useful for number crunching applications 1574 that may need to compute untrusted bytecode during their 1575 execution. By using pipes or other transports made available to 1576 the process as file descriptors supporting the read/write 1577 syscalls, it's possible to isolate those applications in 1578 their own address space using seccomp. Once seccomp is 1579 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1580 and the task is only allowed to execute a few safe syscalls 1581 defined by each seccomp mode. 1582 1583 If unsure, say Y. Only embedded should say N here. 1584 1585source kernel/Kconfig.hz 1586 1587config KEXEC 1588 bool "kexec system call" 1589 ---help--- 1590 kexec is a system call that implements the ability to shutdown your 1591 current kernel, and to start another kernel. It is like a reboot 1592 but it is independent of the system firmware. And like a reboot 1593 you can start any kernel with it, not just Linux. 1594 1595 The name comes from the similarity to the exec system call. 1596 1597 It is an ongoing process to be certain the hardware in a machine 1598 is properly shutdown, so do not be surprised if this code does not 1599 initially work for you. As of this writing the exact hardware 1600 interface is strongly in flux, so no good recommendation can be 1601 made. 1602 1603config KEXEC_FILE 1604 bool "kexec file based system call" 1605 select BUILD_BIN2C 1606 depends on KEXEC 1607 depends on X86_64 1608 depends on CRYPTO=y 1609 depends on CRYPTO_SHA256=y 1610 ---help--- 1611 This is new version of kexec system call. This system call is 1612 file based and takes file descriptors as system call argument 1613 for kernel and initramfs as opposed to list of segments as 1614 accepted by previous system call. 1615 1616config KEXEC_VERIFY_SIG 1617 bool "Verify kernel signature during kexec_file_load() syscall" 1618 depends on KEXEC_FILE 1619 ---help--- 1620 This option makes kernel signature verification mandatory for 1621 kexec_file_load() syscall. If kernel is signature can not be 1622 verified, kexec_file_load() will fail. 1623 1624 This option enforces signature verification at generic level. 1625 One needs to enable signature verification for type of kernel 1626 image being loaded to make sure it works. For example, enable 1627 bzImage signature verification option to be able to load and 1628 verify signatures of bzImage. Otherwise kernel loading will fail. 1629 1630config KEXEC_BZIMAGE_VERIFY_SIG 1631 bool "Enable bzImage signature verification support" 1632 depends on KEXEC_VERIFY_SIG 1633 depends on SIGNED_PE_FILE_VERIFICATION 1634 select SYSTEM_TRUSTED_KEYRING 1635 ---help--- 1636 Enable bzImage signature verification support. 1637 1638config CRASH_DUMP 1639 bool "kernel crash dumps" 1640 depends on X86_64 || (X86_32 && HIGHMEM) 1641 ---help--- 1642 Generate crash dump after being started by kexec. 1643 This should be normally only set in special crash dump kernels 1644 which are loaded in the main kernel with kexec-tools into 1645 a specially reserved region and then later executed after 1646 a crash by kdump/kexec. The crash dump kernel must be compiled 1647 to a memory address not used by the main kernel or BIOS using 1648 PHYSICAL_START, or it must be built as a relocatable image 1649 (CONFIG_RELOCATABLE=y). 1650 For more details see Documentation/kdump/kdump.txt 1651 1652config KEXEC_JUMP 1653 bool "kexec jump" 1654 depends on KEXEC && HIBERNATION 1655 ---help--- 1656 Jump between original kernel and kexeced kernel and invoke 1657 code in physical address mode via KEXEC 1658 1659config PHYSICAL_START 1660 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1661 default "0x1000000" 1662 ---help--- 1663 This gives the physical address where the kernel is loaded. 1664 1665 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1666 bzImage will decompress itself to above physical address and 1667 run from there. Otherwise, bzImage will run from the address where 1668 it has been loaded by the boot loader and will ignore above physical 1669 address. 1670 1671 In normal kdump cases one does not have to set/change this option 1672 as now bzImage can be compiled as a completely relocatable image 1673 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1674 address. This option is mainly useful for the folks who don't want 1675 to use a bzImage for capturing the crash dump and want to use a 1676 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1677 to be specifically compiled to run from a specific memory area 1678 (normally a reserved region) and this option comes handy. 1679 1680 So if you are using bzImage for capturing the crash dump, 1681 leave the value here unchanged to 0x1000000 and set 1682 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1683 for capturing the crash dump change this value to start of 1684 the reserved region. In other words, it can be set based on 1685 the "X" value as specified in the "crashkernel=YM@XM" 1686 command line boot parameter passed to the panic-ed 1687 kernel. Please take a look at Documentation/kdump/kdump.txt 1688 for more details about crash dumps. 1689 1690 Usage of bzImage for capturing the crash dump is recommended as 1691 one does not have to build two kernels. Same kernel can be used 1692 as production kernel and capture kernel. Above option should have 1693 gone away after relocatable bzImage support is introduced. But it 1694 is present because there are users out there who continue to use 1695 vmlinux for dump capture. This option should go away down the 1696 line. 1697 1698 Don't change this unless you know what you are doing. 1699 1700config RELOCATABLE 1701 bool "Build a relocatable kernel" 1702 default y 1703 ---help--- 1704 This builds a kernel image that retains relocation information 1705 so it can be loaded someplace besides the default 1MB. 1706 The relocations tend to make the kernel binary about 10% larger, 1707 but are discarded at runtime. 1708 1709 One use is for the kexec on panic case where the recovery kernel 1710 must live at a different physical address than the primary 1711 kernel. 1712 1713 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1714 it has been loaded at and the compile time physical address 1715 (CONFIG_PHYSICAL_START) is used as the minimum location. 1716 1717config RANDOMIZE_BASE 1718 bool "Randomize the address of the kernel image" 1719 depends on RELOCATABLE 1720 default n 1721 ---help--- 1722 Randomizes the physical and virtual address at which the 1723 kernel image is decompressed, as a security feature that 1724 deters exploit attempts relying on knowledge of the location 1725 of kernel internals. 1726 1727 Entropy is generated using the RDRAND instruction if it is 1728 supported. If RDTSC is supported, it is used as well. If 1729 neither RDRAND nor RDTSC are supported, then randomness is 1730 read from the i8254 timer. 1731 1732 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1733 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1734 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1735 minimum of 2MiB, only 10 bits of entropy is theoretically 1736 possible. At best, due to page table layouts, 64-bit can use 1737 9 bits of entropy and 32-bit uses 8 bits. 1738 1739 If unsure, say N. 1740 1741config RANDOMIZE_BASE_MAX_OFFSET 1742 hex "Maximum kASLR offset allowed" if EXPERT 1743 depends on RANDOMIZE_BASE 1744 range 0x0 0x20000000 if X86_32 1745 default "0x20000000" if X86_32 1746 range 0x0 0x40000000 if X86_64 1747 default "0x40000000" if X86_64 1748 ---help--- 1749 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1750 memory is used to determine the maximal offset in bytes that will 1751 be applied to the kernel when kernel Address Space Layout 1752 Randomization (kASLR) is active. This must be a multiple of 1753 PHYSICAL_ALIGN. 1754 1755 On 32-bit this is limited to 512MiB by page table layouts. The 1756 default is 512MiB. 1757 1758 On 64-bit this is limited by how the kernel fixmap page table is 1759 positioned, so this cannot be larger than 1GiB currently. Without 1760 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1761 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1762 modules area will shrink to compensate, up to the current maximum 1763 1GiB to 1GiB split. The default is 1GiB. 1764 1765 If unsure, leave at the default value. 1766 1767# Relocation on x86 needs some additional build support 1768config X86_NEED_RELOCS 1769 def_bool y 1770 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1771 1772config PHYSICAL_ALIGN 1773 hex "Alignment value to which kernel should be aligned" 1774 default "0x200000" 1775 range 0x2000 0x1000000 if X86_32 1776 range 0x200000 0x1000000 if X86_64 1777 ---help--- 1778 This value puts the alignment restrictions on physical address 1779 where kernel is loaded and run from. Kernel is compiled for an 1780 address which meets above alignment restriction. 1781 1782 If bootloader loads the kernel at a non-aligned address and 1783 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1784 address aligned to above value and run from there. 1785 1786 If bootloader loads the kernel at a non-aligned address and 1787 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1788 load address and decompress itself to the address it has been 1789 compiled for and run from there. The address for which kernel is 1790 compiled already meets above alignment restrictions. Hence the 1791 end result is that kernel runs from a physical address meeting 1792 above alignment restrictions. 1793 1794 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1795 this value must be a multiple of 0x200000. 1796 1797 Don't change this unless you know what you are doing. 1798 1799config HOTPLUG_CPU 1800 bool "Support for hot-pluggable CPUs" 1801 depends on SMP 1802 ---help--- 1803 Say Y here to allow turning CPUs off and on. CPUs can be 1804 controlled through /sys/devices/system/cpu. 1805 ( Note: power management support will enable this option 1806 automatically on SMP systems. ) 1807 Say N if you want to disable CPU hotplug. 1808 1809config BOOTPARAM_HOTPLUG_CPU0 1810 bool "Set default setting of cpu0_hotpluggable" 1811 default n 1812 depends on HOTPLUG_CPU 1813 ---help--- 1814 Set whether default state of cpu0_hotpluggable is on or off. 1815 1816 Say Y here to enable CPU0 hotplug by default. If this switch 1817 is turned on, there is no need to give cpu0_hotplug kernel 1818 parameter and the CPU0 hotplug feature is enabled by default. 1819 1820 Please note: there are two known CPU0 dependencies if you want 1821 to enable the CPU0 hotplug feature either by this switch or by 1822 cpu0_hotplug kernel parameter. 1823 1824 First, resume from hibernate or suspend always starts from CPU0. 1825 So hibernate and suspend are prevented if CPU0 is offline. 1826 1827 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1828 offline if any interrupt can not migrate out of CPU0. There may 1829 be other CPU0 dependencies. 1830 1831 Please make sure the dependencies are under your control before 1832 you enable this feature. 1833 1834 Say N if you don't want to enable CPU0 hotplug feature by default. 1835 You still can enable the CPU0 hotplug feature at boot by kernel 1836 parameter cpu0_hotplug. 1837 1838config DEBUG_HOTPLUG_CPU0 1839 def_bool n 1840 prompt "Debug CPU0 hotplug" 1841 depends on HOTPLUG_CPU 1842 ---help--- 1843 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1844 soon as possible and boots up userspace with CPU0 offlined. User 1845 can online CPU0 back after boot time. 1846 1847 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1848 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1849 compilation or giving cpu0_hotplug kernel parameter at boot. 1850 1851 If unsure, say N. 1852 1853config COMPAT_VDSO 1854 def_bool n 1855 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 1856 depends on X86_32 || IA32_EMULATION 1857 ---help--- 1858 Certain buggy versions of glibc will crash if they are 1859 presented with a 32-bit vDSO that is not mapped at the address 1860 indicated in its segment table. 1861 1862 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 1863 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 1864 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 1865 the only released version with the bug, but OpenSUSE 9 1866 contains a buggy "glibc 2.3.2". 1867 1868 The symptom of the bug is that everything crashes on startup, saying: 1869 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 1870 1871 Saying Y here changes the default value of the vdso32 boot 1872 option from 1 to 0, which turns off the 32-bit vDSO entirely. 1873 This works around the glibc bug but hurts performance. 1874 1875 If unsure, say N: if you are compiling your own kernel, you 1876 are unlikely to be using a buggy version of glibc. 1877 1878config CMDLINE_BOOL 1879 bool "Built-in kernel command line" 1880 ---help--- 1881 Allow for specifying boot arguments to the kernel at 1882 build time. On some systems (e.g. embedded ones), it is 1883 necessary or convenient to provide some or all of the 1884 kernel boot arguments with the kernel itself (that is, 1885 to not rely on the boot loader to provide them.) 1886 1887 To compile command line arguments into the kernel, 1888 set this option to 'Y', then fill in the 1889 the boot arguments in CONFIG_CMDLINE. 1890 1891 Systems with fully functional boot loaders (i.e. non-embedded) 1892 should leave this option set to 'N'. 1893 1894config CMDLINE 1895 string "Built-in kernel command string" 1896 depends on CMDLINE_BOOL 1897 default "" 1898 ---help--- 1899 Enter arguments here that should be compiled into the kernel 1900 image and used at boot time. If the boot loader provides a 1901 command line at boot time, it is appended to this string to 1902 form the full kernel command line, when the system boots. 1903 1904 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1905 change this behavior. 1906 1907 In most cases, the command line (whether built-in or provided 1908 by the boot loader) should specify the device for the root 1909 file system. 1910 1911config CMDLINE_OVERRIDE 1912 bool "Built-in command line overrides boot loader arguments" 1913 depends on CMDLINE_BOOL 1914 ---help--- 1915 Set this option to 'Y' to have the kernel ignore the boot loader 1916 command line, and use ONLY the built-in command line. 1917 1918 This is used to work around broken boot loaders. This should 1919 be set to 'N' under normal conditions. 1920 1921endmenu 1922 1923config ARCH_ENABLE_MEMORY_HOTPLUG 1924 def_bool y 1925 depends on X86_64 || (X86_32 && HIGHMEM) 1926 1927config ARCH_ENABLE_MEMORY_HOTREMOVE 1928 def_bool y 1929 depends on MEMORY_HOTPLUG 1930 1931config USE_PERCPU_NUMA_NODE_ID 1932 def_bool y 1933 depends on NUMA 1934 1935config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1936 def_bool y 1937 depends on X86_64 || X86_PAE 1938 1939config ARCH_ENABLE_HUGEPAGE_MIGRATION 1940 def_bool y 1941 depends on X86_64 && HUGETLB_PAGE && MIGRATION 1942 1943menu "Power management and ACPI options" 1944 1945config ARCH_HIBERNATION_HEADER 1946 def_bool y 1947 depends on X86_64 && HIBERNATION 1948 1949source "kernel/power/Kconfig" 1950 1951source "drivers/acpi/Kconfig" 1952 1953source "drivers/sfi/Kconfig" 1954 1955config X86_APM_BOOT 1956 def_bool y 1957 depends on APM 1958 1959menuconfig APM 1960 tristate "APM (Advanced Power Management) BIOS support" 1961 depends on X86_32 && PM_SLEEP 1962 ---help--- 1963 APM is a BIOS specification for saving power using several different 1964 techniques. This is mostly useful for battery powered laptops with 1965 APM compliant BIOSes. If you say Y here, the system time will be 1966 reset after a RESUME operation, the /proc/apm device will provide 1967 battery status information, and user-space programs will receive 1968 notification of APM "events" (e.g. battery status change). 1969 1970 If you select "Y" here, you can disable actual use of the APM 1971 BIOS by passing the "apm=off" option to the kernel at boot time. 1972 1973 Note that the APM support is almost completely disabled for 1974 machines with more than one CPU. 1975 1976 In order to use APM, you will need supporting software. For location 1977 and more information, read <file:Documentation/power/apm-acpi.txt> 1978 and the Battery Powered Linux mini-HOWTO, available from 1979 <http://www.tldp.org/docs.html#howto>. 1980 1981 This driver does not spin down disk drives (see the hdparm(8) 1982 manpage ("man 8 hdparm") for that), and it doesn't turn off 1983 VESA-compliant "green" monitors. 1984 1985 This driver does not support the TI 4000M TravelMate and the ACER 1986 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1987 desktop machines also don't have compliant BIOSes, and this driver 1988 may cause those machines to panic during the boot phase. 1989 1990 Generally, if you don't have a battery in your machine, there isn't 1991 much point in using this driver and you should say N. If you get 1992 random kernel OOPSes or reboots that don't seem to be related to 1993 anything, try disabling/enabling this option (or disabling/enabling 1994 APM in your BIOS). 1995 1996 Some other things you should try when experiencing seemingly random, 1997 "weird" problems: 1998 1999 1) make sure that you have enough swap space and that it is 2000 enabled. 2001 2) pass the "no-hlt" option to the kernel 2002 3) switch on floating point emulation in the kernel and pass 2003 the "no387" option to the kernel 2004 4) pass the "floppy=nodma" option to the kernel 2005 5) pass the "mem=4M" option to the kernel (thereby disabling 2006 all but the first 4 MB of RAM) 2007 6) make sure that the CPU is not over clocked. 2008 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2009 8) disable the cache from your BIOS settings 2010 9) install a fan for the video card or exchange video RAM 2011 10) install a better fan for the CPU 2012 11) exchange RAM chips 2013 12) exchange the motherboard. 2014 2015 To compile this driver as a module, choose M here: the 2016 module will be called apm. 2017 2018if APM 2019 2020config APM_IGNORE_USER_SUSPEND 2021 bool "Ignore USER SUSPEND" 2022 ---help--- 2023 This option will ignore USER SUSPEND requests. On machines with a 2024 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2025 series notebooks, it is necessary to say Y because of a BIOS bug. 2026 2027config APM_DO_ENABLE 2028 bool "Enable PM at boot time" 2029 ---help--- 2030 Enable APM features at boot time. From page 36 of the APM BIOS 2031 specification: "When disabled, the APM BIOS does not automatically 2032 power manage devices, enter the Standby State, enter the Suspend 2033 State, or take power saving steps in response to CPU Idle calls." 2034 This driver will make CPU Idle calls when Linux is idle (unless this 2035 feature is turned off -- see "Do CPU IDLE calls", below). This 2036 should always save battery power, but more complicated APM features 2037 will be dependent on your BIOS implementation. You may need to turn 2038 this option off if your computer hangs at boot time when using APM 2039 support, or if it beeps continuously instead of suspending. Turn 2040 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2041 T400CDT. This is off by default since most machines do fine without 2042 this feature. 2043 2044config APM_CPU_IDLE 2045 depends on CPU_IDLE 2046 bool "Make CPU Idle calls when idle" 2047 ---help--- 2048 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2049 On some machines, this can activate improved power savings, such as 2050 a slowed CPU clock rate, when the machine is idle. These idle calls 2051 are made after the idle loop has run for some length of time (e.g., 2052 333 mS). On some machines, this will cause a hang at boot time or 2053 whenever the CPU becomes idle. (On machines with more than one CPU, 2054 this option does nothing.) 2055 2056config APM_DISPLAY_BLANK 2057 bool "Enable console blanking using APM" 2058 ---help--- 2059 Enable console blanking using the APM. Some laptops can use this to 2060 turn off the LCD backlight when the screen blanker of the Linux 2061 virtual console blanks the screen. Note that this is only used by 2062 the virtual console screen blanker, and won't turn off the backlight 2063 when using the X Window system. This also doesn't have anything to 2064 do with your VESA-compliant power-saving monitor. Further, this 2065 option doesn't work for all laptops -- it might not turn off your 2066 backlight at all, or it might print a lot of errors to the console, 2067 especially if you are using gpm. 2068 2069config APM_ALLOW_INTS 2070 bool "Allow interrupts during APM BIOS calls" 2071 ---help--- 2072 Normally we disable external interrupts while we are making calls to 2073 the APM BIOS as a measure to lessen the effects of a badly behaving 2074 BIOS implementation. The BIOS should reenable interrupts if it 2075 needs to. Unfortunately, some BIOSes do not -- especially those in 2076 many of the newer IBM Thinkpads. If you experience hangs when you 2077 suspend, try setting this to Y. Otherwise, say N. 2078 2079endif # APM 2080 2081source "drivers/cpufreq/Kconfig" 2082 2083source "drivers/cpuidle/Kconfig" 2084 2085source "drivers/idle/Kconfig" 2086 2087endmenu 2088 2089 2090menu "Bus options (PCI etc.)" 2091 2092config PCI 2093 bool "PCI support" 2094 default y 2095 ---help--- 2096 Find out whether you have a PCI motherboard. PCI is the name of a 2097 bus system, i.e. the way the CPU talks to the other stuff inside 2098 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2099 VESA. If you have PCI, say Y, otherwise N. 2100 2101choice 2102 prompt "PCI access mode" 2103 depends on X86_32 && PCI 2104 default PCI_GOANY 2105 ---help--- 2106 On PCI systems, the BIOS can be used to detect the PCI devices and 2107 determine their configuration. However, some old PCI motherboards 2108 have BIOS bugs and may crash if this is done. Also, some embedded 2109 PCI-based systems don't have any BIOS at all. Linux can also try to 2110 detect the PCI hardware directly without using the BIOS. 2111 2112 With this option, you can specify how Linux should detect the 2113 PCI devices. If you choose "BIOS", the BIOS will be used, 2114 if you choose "Direct", the BIOS won't be used, and if you 2115 choose "MMConfig", then PCI Express MMCONFIG will be used. 2116 If you choose "Any", the kernel will try MMCONFIG, then the 2117 direct access method and falls back to the BIOS if that doesn't 2118 work. If unsure, go with the default, which is "Any". 2119 2120config PCI_GOBIOS 2121 bool "BIOS" 2122 2123config PCI_GOMMCONFIG 2124 bool "MMConfig" 2125 2126config PCI_GODIRECT 2127 bool "Direct" 2128 2129config PCI_GOOLPC 2130 bool "OLPC XO-1" 2131 depends on OLPC 2132 2133config PCI_GOANY 2134 bool "Any" 2135 2136endchoice 2137 2138config PCI_BIOS 2139 def_bool y 2140 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2141 2142# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2143config PCI_DIRECT 2144 def_bool y 2145 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2146 2147config PCI_MMCONFIG 2148 def_bool y 2149 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2150 2151config PCI_OLPC 2152 def_bool y 2153 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2154 2155config PCI_XEN 2156 def_bool y 2157 depends on PCI && XEN 2158 select SWIOTLB_XEN 2159 2160config PCI_DOMAINS 2161 def_bool y 2162 depends on PCI 2163 2164config PCI_MMCONFIG 2165 bool "Support mmconfig PCI config space access" 2166 depends on X86_64 && PCI && ACPI 2167 2168config PCI_CNB20LE_QUIRK 2169 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2170 depends on PCI 2171 help 2172 Read the PCI windows out of the CNB20LE host bridge. This allows 2173 PCI hotplug to work on systems with the CNB20LE chipset which do 2174 not have ACPI. 2175 2176 There's no public spec for this chipset, and this functionality 2177 is known to be incomplete. 2178 2179 You should say N unless you know you need this. 2180 2181source "drivers/pci/pcie/Kconfig" 2182 2183source "drivers/pci/Kconfig" 2184 2185# x86_64 have no ISA slots, but can have ISA-style DMA. 2186config ISA_DMA_API 2187 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2188 default y 2189 help 2190 Enables ISA-style DMA support for devices requiring such controllers. 2191 If unsure, say Y. 2192 2193if X86_32 2194 2195config ISA 2196 bool "ISA support" 2197 ---help--- 2198 Find out whether you have ISA slots on your motherboard. ISA is the 2199 name of a bus system, i.e. the way the CPU talks to the other stuff 2200 inside your box. Other bus systems are PCI, EISA, MicroChannel 2201 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2202 newer boards don't support it. If you have ISA, say Y, otherwise N. 2203 2204config EISA 2205 bool "EISA support" 2206 depends on ISA 2207 ---help--- 2208 The Extended Industry Standard Architecture (EISA) bus was 2209 developed as an open alternative to the IBM MicroChannel bus. 2210 2211 The EISA bus provided some of the features of the IBM MicroChannel 2212 bus while maintaining backward compatibility with cards made for 2213 the older ISA bus. The EISA bus saw limited use between 1988 and 2214 1995 when it was made obsolete by the PCI bus. 2215 2216 Say Y here if you are building a kernel for an EISA-based machine. 2217 2218 Otherwise, say N. 2219 2220source "drivers/eisa/Kconfig" 2221 2222config SCx200 2223 tristate "NatSemi SCx200 support" 2224 ---help--- 2225 This provides basic support for National Semiconductor's 2226 (now AMD's) Geode processors. The driver probes for the 2227 PCI-IDs of several on-chip devices, so its a good dependency 2228 for other scx200_* drivers. 2229 2230 If compiled as a module, the driver is named scx200. 2231 2232config SCx200HR_TIMER 2233 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2234 depends on SCx200 2235 default y 2236 ---help--- 2237 This driver provides a clocksource built upon the on-chip 2238 27MHz high-resolution timer. Its also a workaround for 2239 NSC Geode SC-1100's buggy TSC, which loses time when the 2240 processor goes idle (as is done by the scheduler). The 2241 other workaround is idle=poll boot option. 2242 2243config OLPC 2244 bool "One Laptop Per Child support" 2245 depends on !X86_PAE 2246 select GPIOLIB 2247 select OF 2248 select OF_PROMTREE 2249 select IRQ_DOMAIN 2250 ---help--- 2251 Add support for detecting the unique features of the OLPC 2252 XO hardware. 2253 2254config OLPC_XO1_PM 2255 bool "OLPC XO-1 Power Management" 2256 depends on OLPC && MFD_CS5535 && PM_SLEEP 2257 select MFD_CORE 2258 ---help--- 2259 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2260 2261config OLPC_XO1_RTC 2262 bool "OLPC XO-1 Real Time Clock" 2263 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2264 ---help--- 2265 Add support for the XO-1 real time clock, which can be used as a 2266 programmable wakeup source. 2267 2268config OLPC_XO1_SCI 2269 bool "OLPC XO-1 SCI extras" 2270 depends on OLPC && OLPC_XO1_PM 2271 depends on INPUT=y 2272 select POWER_SUPPLY 2273 select GPIO_CS5535 2274 select MFD_CORE 2275 ---help--- 2276 Add support for SCI-based features of the OLPC XO-1 laptop: 2277 - EC-driven system wakeups 2278 - Power button 2279 - Ebook switch 2280 - Lid switch 2281 - AC adapter status updates 2282 - Battery status updates 2283 2284config OLPC_XO15_SCI 2285 bool "OLPC XO-1.5 SCI extras" 2286 depends on OLPC && ACPI 2287 select POWER_SUPPLY 2288 ---help--- 2289 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2290 - EC-driven system wakeups 2291 - AC adapter status updates 2292 - Battery status updates 2293 2294config ALIX 2295 bool "PCEngines ALIX System Support (LED setup)" 2296 select GPIOLIB 2297 ---help--- 2298 This option enables system support for the PCEngines ALIX. 2299 At present this just sets up LEDs for GPIO control on 2300 ALIX2/3/6 boards. However, other system specific setup should 2301 get added here. 2302 2303 Note: You must still enable the drivers for GPIO and LED support 2304 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2305 2306 Note: You have to set alix.force=1 for boards with Award BIOS. 2307 2308config NET5501 2309 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2310 select GPIOLIB 2311 ---help--- 2312 This option enables system support for the Soekris Engineering net5501. 2313 2314config GEOS 2315 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2316 select GPIOLIB 2317 depends on DMI 2318 ---help--- 2319 This option enables system support for the Traverse Technologies GEOS. 2320 2321config TS5500 2322 bool "Technologic Systems TS-5500 platform support" 2323 depends on MELAN 2324 select CHECK_SIGNATURE 2325 select NEW_LEDS 2326 select LEDS_CLASS 2327 ---help--- 2328 This option enables system support for the Technologic Systems TS-5500. 2329 2330endif # X86_32 2331 2332config AMD_NB 2333 def_bool y 2334 depends on CPU_SUP_AMD && PCI 2335 2336source "drivers/pcmcia/Kconfig" 2337 2338source "drivers/pci/hotplug/Kconfig" 2339 2340config RAPIDIO 2341 tristate "RapidIO support" 2342 depends on PCI 2343 default n 2344 help 2345 If enabled this option will include drivers and the core 2346 infrastructure code to support RapidIO interconnect devices. 2347 2348source "drivers/rapidio/Kconfig" 2349 2350config X86_SYSFB 2351 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2352 help 2353 Firmwares often provide initial graphics framebuffers so the BIOS, 2354 bootloader or kernel can show basic video-output during boot for 2355 user-guidance and debugging. Historically, x86 used the VESA BIOS 2356 Extensions and EFI-framebuffers for this, which are mostly limited 2357 to x86. 2358 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2359 framebuffers so the new generic system-framebuffer drivers can be 2360 used on x86. If the framebuffer is not compatible with the generic 2361 modes, it is adverticed as fallback platform framebuffer so legacy 2362 drivers like efifb, vesafb and uvesafb can pick it up. 2363 If this option is not selected, all system framebuffers are always 2364 marked as fallback platform framebuffers as usual. 2365 2366 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2367 not be able to pick up generic system framebuffers if this option 2368 is selected. You are highly encouraged to enable simplefb as 2369 replacement if you select this option. simplefb can correctly deal 2370 with generic system framebuffers. But you should still keep vesafb 2371 and others enabled as fallback if a system framebuffer is 2372 incompatible with simplefb. 2373 2374 If unsure, say Y. 2375 2376endmenu 2377 2378 2379menu "Executable file formats / Emulations" 2380 2381source "fs/Kconfig.binfmt" 2382 2383config IA32_EMULATION 2384 bool "IA32 Emulation" 2385 depends on X86_64 2386 select BINFMT_ELF 2387 select COMPAT_BINFMT_ELF 2388 select HAVE_UID16 2389 ---help--- 2390 Include code to run legacy 32-bit programs under a 2391 64-bit kernel. You should likely turn this on, unless you're 2392 100% sure that you don't have any 32-bit programs left. 2393 2394config IA32_AOUT 2395 tristate "IA32 a.out support" 2396 depends on IA32_EMULATION 2397 ---help--- 2398 Support old a.out binaries in the 32bit emulation. 2399 2400config X86_X32 2401 bool "x32 ABI for 64-bit mode" 2402 depends on X86_64 && IA32_EMULATION 2403 ---help--- 2404 Include code to run binaries for the x32 native 32-bit ABI 2405 for 64-bit processors. An x32 process gets access to the 2406 full 64-bit register file and wide data path while leaving 2407 pointers at 32 bits for smaller memory footprint. 2408 2409 You will need a recent binutils (2.22 or later) with 2410 elf32_x86_64 support enabled to compile a kernel with this 2411 option set. 2412 2413config COMPAT 2414 def_bool y 2415 depends on IA32_EMULATION || X86_X32 2416 select ARCH_WANT_OLD_COMPAT_IPC 2417 2418if COMPAT 2419config COMPAT_FOR_U64_ALIGNMENT 2420 def_bool y 2421 2422config SYSVIPC_COMPAT 2423 def_bool y 2424 depends on SYSVIPC 2425 2426config KEYS_COMPAT 2427 def_bool y 2428 depends on KEYS 2429endif 2430 2431endmenu 2432 2433 2434config HAVE_ATOMIC_IOMAP 2435 def_bool y 2436 depends on X86_32 2437 2438config X86_DEV_DMA_OPS 2439 bool 2440 depends on X86_64 || STA2X11 2441 2442config X86_DMA_REMAP 2443 bool 2444 depends on STA2X11 2445 2446config IOSF_MBI 2447 tristate 2448 default m 2449 depends on PCI 2450 2451config PMC_ATOM 2452 def_bool y 2453 depends on PCI 2454 2455source "net/Kconfig" 2456 2457source "drivers/Kconfig" 2458 2459source "drivers/firmware/Kconfig" 2460 2461source "fs/Kconfig" 2462 2463source "arch/x86/Kconfig.debug" 2464 2465source "security/Kconfig" 2466 2467source "crypto/Kconfig" 2468 2469source "arch/x86/kvm/Kconfig" 2470 2471source "lib/Kconfig" 2472