1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH != "i386" 5 ---help--- 6 Say yes to build a 64-bit kernel - formerly known as x86_64 7 Say no to build a 32-bit kernel - formerly known as i386 8 9config X86_32 10 def_bool y 11 depends on !64BIT 12 select CLKSRC_I8253 13 select HAVE_UID16 14 15config X86_64 16 def_bool y 17 depends on 64BIT 18 select X86_DEV_DMA_OPS 19 select ARCH_USE_CMPXCHG_LOCKREF 20 21### Arch settings 22config X86 23 def_bool y 24 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 26 select ARCH_HAS_FAST_MULTIPLIER 27 select ARCH_HAS_GCOV_PROFILE_ALL 28 select ARCH_HAS_KCOV if X86_64 29 select ARCH_HAS_PMEM_API if X86_64 30 select ARCH_HAS_MMIO_FLUSH 31 select ARCH_HAS_SG_CHAIN 32 select ARCH_HAS_UBSAN_SANITIZE_ALL 33 select ARCH_MIGHT_HAVE_PC_PARPORT 34 select ARCH_MIGHT_HAVE_PC_SERIO 35 select HAVE_AOUT if X86_32 36 select HAVE_UNSTABLE_SCHED_CLOCK 37 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 38 select ARCH_SUPPORTS_INT128 if X86_64 39 select HAVE_IDE 40 select HAVE_OPROFILE 41 select HAVE_PCSPKR_PLATFORM 42 select HAVE_PERF_EVENTS 43 select HAVE_IOREMAP_PROT 44 select HAVE_KPROBES 45 select HAVE_MEMBLOCK 46 select HAVE_MEMBLOCK_NODE_MAP 47 select ARCH_DISCARD_MEMBLOCK 48 select ARCH_WANT_OPTIONAL_GPIOLIB 49 select ARCH_WANT_FRAME_POINTERS 50 select HAVE_ARCH_HARDENED_USERCOPY 51 select HAVE_ARCH_WITHIN_STACK_FRAMES 52 select HAVE_DMA_ATTRS 53 select HAVE_DMA_CONTIGUOUS 54 select HAVE_KRETPROBES 55 select GENERIC_EARLY_IOREMAP 56 select HAVE_OPTPROBES 57 select HAVE_KPROBES_ON_FTRACE 58 select HAVE_FTRACE_MCOUNT_RECORD 59 select HAVE_FENTRY if X86_64 60 select HAVE_C_RECORDMCOUNT 61 select HAVE_DYNAMIC_FTRACE 62 select HAVE_DYNAMIC_FTRACE_WITH_REGS 63 select HAVE_EXIT_THREAD 64 select HAVE_FUNCTION_TRACER 65 select HAVE_FUNCTION_GRAPH_TRACER 66 select HAVE_FUNCTION_GRAPH_FP_TEST 67 select HAVE_SYSCALL_TRACEPOINTS 68 select SYSCTL_EXCEPTION_TRACE 69 select HAVE_KVM 70 select HAVE_ARCH_KGDB 71 select HAVE_ARCH_TRACEHOOK 72 select HAVE_GENERIC_DMA_COHERENT if X86_32 73 select HAVE_EFFICIENT_UNALIGNED_ACCESS 74 select USER_STACKTRACE_SUPPORT 75 select HAVE_REGS_AND_STACK_ACCESS_API 76 select HAVE_DMA_API_DEBUG 77 select HAVE_KERNEL_GZIP 78 select HAVE_KERNEL_BZIP2 79 select HAVE_KERNEL_LZMA 80 select HAVE_KERNEL_XZ 81 select HAVE_KERNEL_LZO 82 select HAVE_KERNEL_LZ4 83 select HAVE_HW_BREAKPOINT 84 select HAVE_MIXED_BREAKPOINTS_REGS 85 select PERF_EVENTS 86 select HAVE_PERF_EVENTS_NMI 87 select HAVE_PERF_REGS 88 select HAVE_PERF_USER_STACK_DUMP 89 select HAVE_DEBUG_KMEMLEAK 90 select ANON_INODES 91 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 92 select HAVE_CMPXCHG_LOCAL 93 select HAVE_CMPXCHG_DOUBLE 94 select HAVE_ARCH_KMEMCHECK 95 select HAVE_USER_RETURN_NOTIFIER 96 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 97 select HAVE_ARCH_JUMP_LABEL 98 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 99 select SPARSE_IRQ 100 select GENERIC_FIND_FIRST_BIT 101 select GENERIC_IRQ_PROBE 102 select GENERIC_PENDING_IRQ if SMP 103 select GENERIC_IRQ_SHOW 104 select GENERIC_CLOCKEVENTS_MIN_ADJUST 105 select IRQ_FORCED_THREADING 106 select HAVE_BPF_JIT if X86_64 107 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 108 select ARCH_HAS_SG_CHAIN 109 select CLKEVT_I8253 110 select ARCH_HAVE_NMI_SAFE_CMPXCHG 111 select GENERIC_IOMAP 112 select DCACHE_WORD_ACCESS 113 select GENERIC_SMP_IDLE_THREAD 114 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 115 select HAVE_ARCH_MMAP_RND_BITS if MMU 116 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 117 select HAVE_ARCH_SECCOMP_FILTER 118 select BUILDTIME_EXTABLE_SORT 119 select GENERIC_CMOS_UPDATE 120 select HAVE_ARCH_SOFT_DIRTY if X86_64 121 select CLOCKSOURCE_WATCHDOG 122 select GENERIC_CLOCKEVENTS 123 select ARCH_CLOCKSOURCE_DATA 124 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 125 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 126 select GENERIC_TIME_VSYSCALL 127 select GENERIC_STRNCPY_FROM_USER 128 select GENERIC_STRNLEN_USER 129 select HAVE_CONTEXT_TRACKING if X86_64 130 select HAVE_IRQ_TIME_ACCOUNTING 131 select VIRT_TO_BUS 132 select MODULES_USE_ELF_REL if X86_32 133 select MODULES_USE_ELF_RELA if X86_64 134 select CLONE_BACKWARDS if X86_32 135 select ARCH_USE_BUILTIN_BSWAP 136 select ARCH_USE_QUEUE_RWLOCK 137 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 138 select OLD_SIGACTION if X86_32 139 select COMPAT_OLD_SIGACTION if IA32_EMULATION 140 select RTC_LIB 141 select HAVE_DEBUG_STACKOVERFLOW 142 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 143 select HAVE_CC_STACKPROTECTOR 144 select GENERIC_CPU_AUTOPROBE 145 select HAVE_ARCH_AUDITSYSCALL 146 select ARCH_SUPPORTS_ATOMIC_RMW 147 select HAVE_ACPI_APEI if ACPI 148 select HAVE_ACPI_APEI_NMI if ACPI 149 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 150 select X86_FEATURE_NAMES if PROC_FS 151 152config INSTRUCTION_DECODER 153 def_bool y 154 depends on KPROBES || PERF_EVENTS || UPROBES 155 156config PERF_EVENTS_INTEL_UNCORE 157 def_bool y 158 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 159 160config OUTPUT_FORMAT 161 string 162 default "elf32-i386" if X86_32 163 default "elf64-x86-64" if X86_64 164 165config ARCH_DEFCONFIG 166 string 167 default "arch/x86/configs/i386_defconfig" if X86_32 168 default "arch/x86/configs/x86_64_defconfig" if X86_64 169 170config LOCKDEP_SUPPORT 171 def_bool y 172 173config STACKTRACE_SUPPORT 174 def_bool y 175 176config HAVE_LATENCYTOP_SUPPORT 177 def_bool y 178 179config MMU 180 def_bool y 181 182config ARCH_MMAP_RND_BITS_MIN 183 default 28 if 64BIT 184 default 8 185 186config ARCH_MMAP_RND_BITS_MAX 187 default 32 if 64BIT 188 default 16 189 190config ARCH_MMAP_RND_COMPAT_BITS_MIN 191 default 8 192 193config ARCH_MMAP_RND_COMPAT_BITS_MAX 194 default 16 195 196config SBUS 197 bool 198 199config NEED_DMA_MAP_STATE 200 def_bool y 201 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 202 203config NEED_SG_DMA_LENGTH 204 def_bool y 205 206config GENERIC_ISA_DMA 207 def_bool y 208 depends on ISA_DMA_API 209 210config GENERIC_BUG 211 def_bool y 212 depends on BUG 213 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 214 215config GENERIC_BUG_RELATIVE_POINTERS 216 bool 217 218config GENERIC_HWEIGHT 219 def_bool y 220 221config ARCH_MAY_HAVE_PC_FDC 222 def_bool y 223 depends on ISA_DMA_API 224 225config RWSEM_XCHGADD_ALGORITHM 226 def_bool y 227 228config GENERIC_CALIBRATE_DELAY 229 def_bool y 230 231config ARCH_HAS_CPU_RELAX 232 def_bool y 233 234config ARCH_HAS_CACHE_LINE_SIZE 235 def_bool y 236 237config HAVE_SETUP_PER_CPU_AREA 238 def_bool y 239 240config NEED_PER_CPU_EMBED_FIRST_CHUNK 241 def_bool y 242 243config NEED_PER_CPU_PAGE_FIRST_CHUNK 244 def_bool y 245 246config ARCH_HIBERNATION_POSSIBLE 247 def_bool y 248 249config ARCH_SUSPEND_POSSIBLE 250 def_bool y 251 252config ARCH_WANT_HUGE_PMD_SHARE 253 def_bool y 254 255config ARCH_WANT_GENERAL_HUGETLB 256 def_bool y 257 258config ZONE_DMA32 259 bool 260 default X86_64 261 262config AUDIT_ARCH 263 bool 264 default X86_64 265 266config ARCH_SUPPORTS_OPTIMIZED_INLINING 267 def_bool y 268 269config ARCH_SUPPORTS_DEBUG_PAGEALLOC 270 def_bool y 271 272config HAVE_INTEL_TXT 273 def_bool y 274 depends on INTEL_IOMMU && ACPI 275 276config X86_32_SMP 277 def_bool y 278 depends on X86_32 && SMP 279 280config X86_64_SMP 281 def_bool y 282 depends on X86_64 && SMP 283 284config X86_HT 285 def_bool y 286 depends on SMP 287 288config X86_32_LAZY_GS 289 def_bool y 290 depends on X86_32 && !CC_STACKPROTECTOR 291 292config ARCH_HWEIGHT_CFLAGS 293 string 294 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 295 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_64 296 297config ARCH_SUPPORTS_UPROBES 298 def_bool y 299 300config FIX_EARLYCON_MEM 301 def_bool y 302 303config DEBUG_RODATA 304 def_bool y 305 306source "init/Kconfig" 307source "kernel/Kconfig.freezer" 308 309menu "Processor type and features" 310 311config ZONE_DMA 312 bool "DMA memory allocation support" if EXPERT 313 default y 314 help 315 DMA memory allocation support allows devices with less than 32-bit 316 addressing to allocate within the first 16MB of address space. 317 Disable if no such devices will be used. 318 319 If unsure, say Y. 320 321config SMP 322 bool "Symmetric multi-processing support" 323 ---help--- 324 This enables support for systems with more than one CPU. If you have 325 a system with only one CPU, say N. If you have a system with more 326 than one CPU, say Y. 327 328 If you say N here, the kernel will run on uni- and multiprocessor 329 machines, but will use only one CPU of a multiprocessor machine. If 330 you say Y here, the kernel will run on many, but not all, 331 uniprocessor machines. On a uniprocessor machine, the kernel 332 will run faster if you say N here. 333 334 Note that if you say Y here and choose architecture "586" or 335 "Pentium" under "Processor family", the kernel will not work on 486 336 architectures. Similarly, multiprocessor kernels for the "PPro" 337 architecture may not work on all Pentium based boards. 338 339 People using multiprocessor machines who say Y here should also say 340 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 341 Management" code will be disabled if you say Y here. 342 343 See also <file:Documentation/x86/i386/IO-APIC.txt>, 344 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 345 <http://www.tldp.org/docs.html#howto>. 346 347 If you don't know what to do here, say N. 348 349config X86_FEATURE_NAMES 350 bool "Processor feature human-readable names" if EMBEDDED 351 default y 352 ---help--- 353 This option compiles in a table of x86 feature bits and corresponding 354 names. This is required to support /proc/cpuinfo and a few kernel 355 messages. You can disable this to save space, at the expense of 356 making those few kernel messages show numeric feature bits instead. 357 358 If in doubt, say Y. 359 360config X86_X2APIC 361 bool "Support x2apic" 362 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 363 ---help--- 364 This enables x2apic support on CPUs that have this feature. 365 366 This allows 32-bit apic IDs (so it can support very large systems), 367 and accesses the local apic via MSRs not via mmio. 368 369 If you don't know what to do here, say N. 370 371config X86_MPPARSE 372 bool "Enable MPS table" if ACPI || SFI 373 default y 374 depends on X86_LOCAL_APIC 375 ---help--- 376 For old smp systems that do not have proper acpi support. Newer systems 377 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 378 379config X86_BIGSMP 380 bool "Support for big SMP systems with more than 8 CPUs" 381 depends on X86_32 && SMP 382 ---help--- 383 This option is needed for the systems that have more than 8 CPUs 384 385if X86_32 386config X86_EXTENDED_PLATFORM 387 bool "Support for extended (non-PC) x86 platforms" 388 default y 389 ---help--- 390 If you disable this option then the kernel will only support 391 standard PC platforms. (which covers the vast majority of 392 systems out there.) 393 394 If you enable this option then you'll be able to select support 395 for the following (non-PC) 32 bit x86 platforms: 396 Goldfish (Android emulator) 397 AMD Elan 398 RDC R-321x SoC 399 SGI 320/540 (Visual Workstation) 400 STA2X11-based (e.g. Northville) 401 Moorestown MID devices 402 403 If you have one of these systems, or if you want to build a 404 generic distribution kernel, say Y here - otherwise say N. 405endif 406 407if X86_64 408config X86_EXTENDED_PLATFORM 409 bool "Support for extended (non-PC) x86 platforms" 410 default y 411 ---help--- 412 If you disable this option then the kernel will only support 413 standard PC platforms. (which covers the vast majority of 414 systems out there.) 415 416 If you enable this option then you'll be able to select support 417 for the following (non-PC) 64 bit x86 platforms: 418 Numascale NumaChip 419 ScaleMP vSMP 420 SGI Ultraviolet 421 422 If you have one of these systems, or if you want to build a 423 generic distribution kernel, say Y here - otherwise say N. 424endif 425# This is an alphabetically sorted list of 64 bit extended platforms 426# Please maintain the alphabetic order if and when there are additions 427config X86_NUMACHIP 428 bool "Numascale NumaChip" 429 depends on X86_64 430 depends on X86_EXTENDED_PLATFORM 431 depends on NUMA 432 depends on SMP 433 depends on X86_X2APIC 434 depends on PCI_MMCONFIG 435 ---help--- 436 Adds support for Numascale NumaChip large-SMP systems. Needed to 437 enable more than ~168 cores. 438 If you don't have one of these, you should say N here. 439 440config X86_VSMP 441 bool "ScaleMP vSMP" 442 select HYPERVISOR_GUEST 443 select PARAVIRT 444 depends on X86_64 && PCI 445 depends on X86_EXTENDED_PLATFORM 446 depends on SMP 447 ---help--- 448 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 449 supposed to run on these EM64T-based machines. Only choose this option 450 if you have one of these machines. 451 452config X86_UV 453 bool "SGI Ultraviolet" 454 depends on X86_64 455 depends on X86_EXTENDED_PLATFORM 456 depends on NUMA 457 depends on X86_X2APIC 458 ---help--- 459 This option is needed in order to support SGI Ultraviolet systems. 460 If you don't have one of these, you should say N here. 461 462# Following is an alphabetically sorted list of 32 bit extended platforms 463# Please maintain the alphabetic order if and when there are additions 464 465config X86_INTEL_CE 466 bool "CE4100 TV platform" 467 depends on PCI 468 depends on PCI_GODIRECT 469 depends on X86_IO_APIC 470 depends on X86_32 471 depends on X86_EXTENDED_PLATFORM 472 select X86_REBOOTFIXUPS 473 select OF 474 select OF_EARLY_FLATTREE 475 select IRQ_DOMAIN 476 ---help--- 477 Select for the Intel CE media processor (CE4100) SOC. 478 This option compiles in support for the CE4100 SOC for settop 479 boxes and media devices. 480 481config X86_INTEL_MID 482 bool "Intel MID platform support" 483 depends on X86_32 484 depends on X86_EXTENDED_PLATFORM 485 depends on X86_PLATFORM_DEVICES 486 depends on PCI 487 depends on PCI_GOANY 488 depends on X86_IO_APIC 489 select SFI 490 select I2C 491 select DW_APB_TIMER 492 select APB_TIMER 493 select INTEL_SCU_IPC 494 select MFD_INTEL_MSIC 495 ---help--- 496 Select to build a kernel capable of supporting Intel MID (Mobile 497 Internet Device) platform systems which do not have the PCI legacy 498 interfaces. If you are building for a PC class system say N here. 499 500 Intel MID platforms are based on an Intel processor and chipset which 501 consume less power than most of the x86 derivatives. 502 503config X86_INTEL_LPSS 504 bool "Intel Low Power Subsystem Support" 505 depends on ACPI 506 select COMMON_CLK 507 select PINCTRL 508 ---help--- 509 Select to build support for Intel Low Power Subsystem such as 510 found on Intel Lynxpoint PCH. Selecting this option enables 511 things like clock tree (common clock framework) and pincontrol 512 which are needed by the LPSS peripheral drivers. 513 514config IOSF_MBI 515 tristate "Intel SoC IOSF Sideband support for SoC platforms" 516 depends on PCI 517 ---help--- 518 This option enables sideband register access support for Intel SoC 519 platforms. On these platforms the IOSF sideband is used in lieu of 520 MSR's for some register accesses, mostly but not limited to thermal 521 and power. Drivers may query the availability of this device to 522 determine if they need the sideband in order to work on these 523 platforms. The sideband is available on the following SoC products. 524 This list is not meant to be exclusive. 525 - BayTrail 526 - Braswell 527 - Quark 528 529 You should say Y if you are running a kernel on one of these SoC's. 530 531config IOSF_MBI_DEBUG 532 bool "Enable IOSF sideband access through debugfs" 533 depends on IOSF_MBI && DEBUG_FS 534 ---help--- 535 Select this option to expose the IOSF sideband access registers (MCR, 536 MDR, MCRX) through debugfs to write and read register information from 537 different units on the SoC. This is most useful for obtaining device 538 state information for debug and analysis. As this is a general access 539 mechanism, users of this option would have specific knowledge of the 540 device they want to access. 541 542 If you don't require the option or are in doubt, say N. 543 544config X86_RDC321X 545 bool "RDC R-321x SoC" 546 depends on X86_32 547 depends on X86_EXTENDED_PLATFORM 548 select M486 549 select X86_REBOOTFIXUPS 550 ---help--- 551 This option is needed for RDC R-321x system-on-chip, also known 552 as R-8610-(G). 553 If you don't have one of these chips, you should say N here. 554 555config X86_32_NON_STANDARD 556 bool "Support non-standard 32-bit SMP architectures" 557 depends on X86_32 && SMP 558 depends on X86_EXTENDED_PLATFORM 559 ---help--- 560 This option compiles in the bigsmp and STA2X11 default 561 subarchitectures. It is intended for a generic binary 562 kernel. If you select them all, kernel will probe it one by 563 one and will fallback to default. 564 565# Alphabetically sorted list of Non standard 32 bit platforms 566 567config X86_SUPPORTS_MEMORY_FAILURE 568 def_bool y 569 # MCE code calls memory_failure(): 570 depends on X86_MCE 571 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 572 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 573 depends on X86_64 || !SPARSEMEM 574 select ARCH_SUPPORTS_MEMORY_FAILURE 575 576config STA2X11 577 bool "STA2X11 Companion Chip Support" 578 depends on X86_32_NON_STANDARD && PCI 579 select X86_DEV_DMA_OPS 580 select X86_DMA_REMAP 581 select SWIOTLB 582 select MFD_STA2X11 583 select ARCH_REQUIRE_GPIOLIB 584 default n 585 ---help--- 586 This adds support for boards based on the STA2X11 IO-Hub, 587 a.k.a. "ConneXt". The chip is used in place of the standard 588 PC chipset, so all "standard" peripherals are missing. If this 589 option is selected the kernel will still be able to boot on 590 standard PC machines. 591 592config X86_32_IRIS 593 tristate "Eurobraille/Iris poweroff module" 594 depends on X86_32 595 ---help--- 596 The Iris machines from EuroBraille do not have APM or ACPI support 597 to shut themselves down properly. A special I/O sequence is 598 needed to do so, which is what this module does at 599 kernel shutdown. 600 601 This is only for Iris machines from EuroBraille. 602 603 If unused, say N. 604 605config SCHED_OMIT_FRAME_POINTER 606 def_bool y 607 prompt "Single-depth WCHAN output" 608 depends on X86 609 ---help--- 610 Calculate simpler /proc/<PID>/wchan values. If this option 611 is disabled then wchan values will recurse back to the 612 caller function. This provides more accurate wchan values, 613 at the expense of slightly more scheduling overhead. 614 615 If in doubt, say "Y". 616 617menuconfig HYPERVISOR_GUEST 618 bool "Linux guest support" 619 ---help--- 620 Say Y here to enable options for running Linux under various hyper- 621 visors. This option enables basic hypervisor detection and platform 622 setup. 623 624 If you say N, all options in this submenu will be skipped and 625 disabled, and Linux guest support won't be built in. 626 627if HYPERVISOR_GUEST 628 629config PARAVIRT 630 bool "Enable paravirtualization code" 631 ---help--- 632 This changes the kernel so it can modify itself when it is run 633 under a hypervisor, potentially improving performance significantly 634 over full virtualization. However, when run without a hypervisor 635 the kernel is theoretically slower and slightly larger. 636 637config PARAVIRT_DEBUG 638 bool "paravirt-ops debugging" 639 depends on PARAVIRT && DEBUG_KERNEL 640 ---help--- 641 Enable to debug paravirt_ops internals. Specifically, BUG if 642 a paravirt_op is missing when it is called. 643 644config PARAVIRT_SPINLOCKS 645 bool "Paravirtualization layer for spinlocks" 646 depends on PARAVIRT && SMP 647 select UNINLINE_SPIN_UNLOCK 648 ---help--- 649 Paravirtualized spinlocks allow a pvops backend to replace the 650 spinlock implementation with something virtualization-friendly 651 (for example, block the virtual CPU rather than spinning). 652 653 It has a minimal impact on native kernels and gives a nice performance 654 benefit on paravirtualized KVM / Xen kernels. 655 656 If you are unsure how to answer this question, answer Y. 657 658source "arch/x86/xen/Kconfig" 659 660config KVM_GUEST 661 bool "KVM Guest support (including kvmclock)" 662 depends on PARAVIRT 663 select PARAVIRT_CLOCK 664 default y 665 ---help--- 666 This option enables various optimizations for running under the KVM 667 hypervisor. It includes a paravirtualized clock, so that instead 668 of relying on a PIT (or probably other) emulation by the 669 underlying device model, the host provides the guest with 670 timing infrastructure such as time of day, and system time 671 672config KVM_DEBUG_FS 673 bool "Enable debug information for KVM Guests in debugfs" 674 depends on KVM_GUEST && DEBUG_FS 675 default n 676 ---help--- 677 This option enables collection of various statistics for KVM guest. 678 Statistics are displayed in debugfs filesystem. Enabling this option 679 may incur significant overhead. 680 681source "arch/x86/lguest/Kconfig" 682 683config PARAVIRT_TIME_ACCOUNTING 684 bool "Paravirtual steal time accounting" 685 depends on PARAVIRT 686 default n 687 ---help--- 688 Select this option to enable fine granularity task steal time 689 accounting. Time spent executing other tasks in parallel with 690 the current vCPU is discounted from the vCPU power. To account for 691 that, there can be a small performance impact. 692 693 If in doubt, say N here. 694 695config PARAVIRT_CLOCK 696 bool 697 698endif #HYPERVISOR_GUEST 699 700config NO_BOOTMEM 701 def_bool y 702 703config MEMTEST 704 bool "Memtest" 705 ---help--- 706 This option adds a kernel parameter 'memtest', which allows memtest 707 to be set. 708 memtest=0, mean disabled; -- default 709 memtest=1, mean do 1 test pattern; 710 ... 711 memtest=4, mean do 4 test patterns. 712 If you are unsure how to answer this question, answer N. 713 714source "arch/x86/Kconfig.cpu" 715 716config HPET_TIMER 717 def_bool X86_64 718 prompt "HPET Timer Support" if X86_32 719 ---help--- 720 Use the IA-PC HPET (High Precision Event Timer) to manage 721 time in preference to the PIT and RTC, if a HPET is 722 present. 723 HPET is the next generation timer replacing legacy 8254s. 724 The HPET provides a stable time base on SMP 725 systems, unlike the TSC, but it is more expensive to access, 726 as it is off-chip. You can find the HPET spec at 727 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 728 729 You can safely choose Y here. However, HPET will only be 730 activated if the platform and the BIOS support this feature. 731 Otherwise the 8254 will be used for timing services. 732 733 Choose N to continue using the legacy 8254 timer. 734 735config HPET_EMULATE_RTC 736 def_bool y 737 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 738 739config APB_TIMER 740 def_bool y if X86_INTEL_MID 741 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 742 select DW_APB_TIMER 743 depends on X86_INTEL_MID && SFI 744 help 745 APB timer is the replacement for 8254, HPET on X86 MID platforms. 746 The APBT provides a stable time base on SMP 747 systems, unlike the TSC, but it is more expensive to access, 748 as it is off-chip. APB timers are always running regardless of CPU 749 C states, they are used as per CPU clockevent device when possible. 750 751# Mark as expert because too many people got it wrong. 752# The code disables itself when not needed. 753config DMI 754 default y 755 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 756 bool "Enable DMI scanning" if EXPERT 757 ---help--- 758 Enabled scanning of DMI to identify machine quirks. Say Y 759 here unless you have verified that your setup is not 760 affected by entries in the DMI blacklist. Required by PNP 761 BIOS code. 762 763config GART_IOMMU 764 bool "Old AMD GART IOMMU support" 765 select SWIOTLB 766 depends on X86_64 && PCI && AMD_NB 767 ---help--- 768 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 769 GART based hardware IOMMUs. 770 771 The GART supports full DMA access for devices with 32-bit access 772 limitations, on systems with more than 3 GB. This is usually needed 773 for USB, sound, many IDE/SATA chipsets and some other devices. 774 775 Newer systems typically have a modern AMD IOMMU, supported via 776 the CONFIG_AMD_IOMMU=y config option. 777 778 In normal configurations this driver is only active when needed: 779 there's more than 3 GB of memory and the system contains a 780 32-bit limited device. 781 782 If unsure, say Y. 783 784config CALGARY_IOMMU 785 bool "IBM Calgary IOMMU support" 786 select SWIOTLB 787 depends on X86_64 && PCI 788 ---help--- 789 Support for hardware IOMMUs in IBM's xSeries x366 and x460 790 systems. Needed to run systems with more than 3GB of memory 791 properly with 32-bit PCI devices that do not support DAC 792 (Double Address Cycle). Calgary also supports bus level 793 isolation, where all DMAs pass through the IOMMU. This 794 prevents them from going anywhere except their intended 795 destination. This catches hard-to-find kernel bugs and 796 mis-behaving drivers and devices that do not use the DMA-API 797 properly to set up their DMA buffers. The IOMMU can be 798 turned off at boot time with the iommu=off parameter. 799 Normally the kernel will make the right choice by itself. 800 If unsure, say Y. 801 802config CALGARY_IOMMU_ENABLED_BY_DEFAULT 803 def_bool y 804 prompt "Should Calgary be enabled by default?" 805 depends on CALGARY_IOMMU 806 ---help--- 807 Should Calgary be enabled by default? if you choose 'y', Calgary 808 will be used (if it exists). If you choose 'n', Calgary will not be 809 used even if it exists. If you choose 'n' and would like to use 810 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 811 If unsure, say Y. 812 813# need this always selected by IOMMU for the VIA workaround 814config SWIOTLB 815 def_bool y if X86_64 816 ---help--- 817 Support for software bounce buffers used on x86-64 systems 818 which don't have a hardware IOMMU. Using this PCI devices 819 which can only access 32-bits of memory can be used on systems 820 with more than 3 GB of memory. 821 If unsure, say Y. 822 823config IOMMU_HELPER 824 def_bool y 825 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 826 827config MAXSMP 828 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 829 depends on X86_64 && SMP && DEBUG_KERNEL 830 select CPUMASK_OFFSTACK 831 ---help--- 832 Enable maximum number of CPUS and NUMA Nodes for this architecture. 833 If unsure, say N. 834 835config NR_CPUS 836 int "Maximum number of CPUs" if SMP && !MAXSMP 837 range 2 8 if SMP && X86_32 && !X86_BIGSMP 838 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 839 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 840 default "1" if !SMP 841 default "8192" if MAXSMP 842 default "32" if SMP && X86_BIGSMP 843 default "8" if SMP 844 ---help--- 845 This allows you to specify the maximum number of CPUs which this 846 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 847 supported value is 4096, otherwise the maximum value is 512. The 848 minimum value which makes sense is 2. 849 850 This is purely to save memory - each supported CPU adds 851 approximately eight kilobytes to the kernel image. 852 853config SCHED_SMT 854 bool "SMT (Hyperthreading) scheduler support" 855 depends on X86_HT 856 ---help--- 857 SMT scheduler support improves the CPU scheduler's decision making 858 when dealing with Intel Pentium 4 chips with HyperThreading at a 859 cost of slightly increased overhead in some places. If unsure say 860 N here. 861 862config SCHED_MC 863 def_bool y 864 prompt "Multi-core scheduler support" 865 depends on X86_HT 866 ---help--- 867 Multi-core scheduler support improves the CPU scheduler's decision 868 making when dealing with multi-core CPU chips at a cost of slightly 869 increased overhead in some places. If unsure say N here. 870 871source "kernel/Kconfig.preempt" 872 873config X86_UP_APIC 874 bool "Local APIC support on uniprocessors" 875 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 876 ---help--- 877 A local APIC (Advanced Programmable Interrupt Controller) is an 878 integrated interrupt controller in the CPU. If you have a single-CPU 879 system which has a processor with a local APIC, you can say Y here to 880 enable and use it. If you say Y here even though your machine doesn't 881 have a local APIC, then the kernel will still run with no slowdown at 882 all. The local APIC supports CPU-generated self-interrupts (timer, 883 performance counters), and the NMI watchdog which detects hard 884 lockups. 885 886config X86_UP_APIC_MSI 887 def_bool y 888 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI 889 890config X86_UP_IOAPIC 891 bool "IO-APIC support on uniprocessors" 892 depends on X86_UP_APIC 893 ---help--- 894 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 895 SMP-capable replacement for PC-style interrupt controllers. Most 896 SMP systems and many recent uniprocessor systems have one. 897 898 If you have a single-CPU system with an IO-APIC, you can say Y here 899 to use it. If you say Y here even though your machine doesn't have 900 an IO-APIC, then the kernel will still run with no slowdown at all. 901 902config X86_LOCAL_APIC 903 def_bool y 904 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 905 906config X86_IO_APIC 907 def_bool y 908 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 909 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ 910 select IRQ_DOMAIN 911 912config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 913 bool "Reroute for broken boot IRQs" 914 depends on X86_IO_APIC 915 ---help--- 916 This option enables a workaround that fixes a source of 917 spurious interrupts. This is recommended when threaded 918 interrupt handling is used on systems where the generation of 919 superfluous "boot interrupts" cannot be disabled. 920 921 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 922 entry in the chipset's IO-APIC is masked (as, e.g. the RT 923 kernel does during interrupt handling). On chipsets where this 924 boot IRQ generation cannot be disabled, this workaround keeps 925 the original IRQ line masked so that only the equivalent "boot 926 IRQ" is delivered to the CPUs. The workaround also tells the 927 kernel to set up the IRQ handler on the boot IRQ line. In this 928 way only one interrupt is delivered to the kernel. Otherwise 929 the spurious second interrupt may cause the kernel to bring 930 down (vital) interrupt lines. 931 932 Only affects "broken" chipsets. Interrupt sharing may be 933 increased on these systems. 934 935config X86_MCE 936 bool "Machine Check / overheating reporting" 937 default y 938 ---help--- 939 Machine Check support allows the processor to notify the 940 kernel if it detects a problem (e.g. overheating, data corruption). 941 The action the kernel takes depends on the severity of the problem, 942 ranging from warning messages to halting the machine. 943 944config X86_MCE_INTEL 945 def_bool y 946 prompt "Intel MCE features" 947 depends on X86_MCE && X86_LOCAL_APIC 948 ---help--- 949 Additional support for intel specific MCE features such as 950 the thermal monitor. 951 952config X86_MCE_AMD 953 def_bool y 954 prompt "AMD MCE features" 955 depends on X86_MCE && X86_LOCAL_APIC 956 ---help--- 957 Additional support for AMD specific MCE features such as 958 the DRAM Error Threshold. 959 960config X86_ANCIENT_MCE 961 bool "Support for old Pentium 5 / WinChip machine checks" 962 depends on X86_32 && X86_MCE 963 ---help--- 964 Include support for machine check handling on old Pentium 5 or WinChip 965 systems. These typically need to be enabled explicitly on the command 966 line. 967 968config X86_MCE_THRESHOLD 969 depends on X86_MCE_AMD || X86_MCE_INTEL 970 def_bool y 971 972config X86_MCE_INJECT 973 depends on X86_MCE 974 tristate "Machine check injector support" 975 ---help--- 976 Provide support for injecting machine checks for testing purposes. 977 If you don't know what a machine check is and you don't do kernel 978 QA it is safe to say n. 979 980config X86_THERMAL_VECTOR 981 def_bool y 982 depends on X86_MCE_INTEL 983 984config VM86 985 bool "Enable VM86 support" if EXPERT 986 default y 987 depends on X86_32 988 ---help--- 989 This option is required by programs like DOSEMU to run 990 16-bit real mode legacy code on x86 processors. It also may 991 be needed by software like XFree86 to initialize some video 992 cards via BIOS. Disabling this option saves about 6K. 993 994config X86_16BIT 995 bool "Enable support for 16-bit segments" if EXPERT 996 default y 997 ---help--- 998 This option is required by programs like Wine to run 16-bit 999 protected mode legacy code on x86 processors. Disabling 1000 this option saves about 300 bytes on i386, or around 6K text 1001 plus 16K runtime memory on x86-64, 1002 1003config X86_ESPFIX32 1004 def_bool y 1005 depends on X86_16BIT && X86_32 1006 1007config X86_ESPFIX64 1008 def_bool y 1009 depends on X86_16BIT && X86_64 1010 1011config TOSHIBA 1012 tristate "Toshiba Laptop support" 1013 depends on X86_32 1014 ---help--- 1015 This adds a driver to safely access the System Management Mode of 1016 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1017 not work on models with a Phoenix BIOS. The System Management Mode 1018 is used to set the BIOS and power saving options on Toshiba portables. 1019 1020 For information on utilities to make use of this driver see the 1021 Toshiba Linux utilities web site at: 1022 <http://www.buzzard.org.uk/toshiba/>. 1023 1024 Say Y if you intend to run this kernel on a Toshiba portable. 1025 Say N otherwise. 1026 1027config I8K 1028 tristate "Dell laptop support" 1029 select HWMON 1030 ---help--- 1031 This adds a driver to safely access the System Management Mode 1032 of the CPU on the Dell Inspiron 8000. The System Management Mode 1033 is used to read cpu temperature and cooling fan status and to 1034 control the fans on the I8K portables. 1035 1036 This driver has been tested only on the Inspiron 8000 but it may 1037 also work with other Dell laptops. You can force loading on other 1038 models by passing the parameter `force=1' to the module. Use at 1039 your own risk. 1040 1041 For information on utilities to make use of this driver see the 1042 I8K Linux utilities web site at: 1043 <http://people.debian.org/~dz/i8k/> 1044 1045 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1046 Say N otherwise. 1047 1048config X86_REBOOTFIXUPS 1049 bool "Enable X86 board specific fixups for reboot" 1050 depends on X86_32 1051 ---help--- 1052 This enables chipset and/or board specific fixups to be done 1053 in order to get reboot to work correctly. This is only needed on 1054 some combinations of hardware and BIOS. The symptom, for which 1055 this config is intended, is when reboot ends with a stalled/hung 1056 system. 1057 1058 Currently, the only fixup is for the Geode machines using 1059 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1060 1061 Say Y if you want to enable the fixup. Currently, it's safe to 1062 enable this option even if you don't need it. 1063 Say N otherwise. 1064 1065config MICROCODE 1066 tristate "CPU microcode loading support" 1067 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1068 select FW_LOADER 1069 ---help--- 1070 1071 If you say Y here, you will be able to update the microcode on 1072 certain Intel and AMD processors. The Intel support is for the 1073 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1074 Xeon etc. The AMD support is for families 0x10 and later. You will 1075 obviously need the actual microcode binary data itself which is not 1076 shipped with the Linux kernel. 1077 1078 This option selects the general module only, you need to select 1079 at least one vendor specific module as well. 1080 1081 To compile this driver as a module, choose M here: the module 1082 will be called microcode. 1083 1084config MICROCODE_INTEL 1085 bool "Intel microcode loading support" 1086 depends on MICROCODE 1087 default MICROCODE 1088 select FW_LOADER 1089 ---help--- 1090 This options enables microcode patch loading support for Intel 1091 processors. 1092 1093 For the current Intel microcode data package go to 1094 <https://downloadcenter.intel.com> and search for 1095 'Linux Processor Microcode Data File'. 1096 1097config MICROCODE_AMD 1098 bool "AMD microcode loading support" 1099 depends on MICROCODE 1100 select FW_LOADER 1101 ---help--- 1102 If you select this option, microcode patch loading support for AMD 1103 processors will be enabled. 1104 1105config MICROCODE_OLD_INTERFACE 1106 def_bool y 1107 depends on MICROCODE 1108 1109config MICROCODE_INTEL_EARLY 1110 def_bool n 1111 1112config MICROCODE_AMD_EARLY 1113 def_bool n 1114 1115config MICROCODE_EARLY 1116 bool "Early load microcode" 1117 depends on MICROCODE=y && BLK_DEV_INITRD 1118 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1119 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1120 default y 1121 help 1122 This option provides functionality to read additional microcode data 1123 at the beginning of initrd image. The data tells kernel to load 1124 microcode to CPU's as early as possible. No functional change if no 1125 microcode data is glued to the initrd, therefore it's safe to say Y. 1126 1127config X86_MSR 1128 tristate "/dev/cpu/*/msr - Model-specific register support" 1129 ---help--- 1130 This device gives privileged processes access to the x86 1131 Model-Specific Registers (MSRs). It is a character device with 1132 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1133 MSR accesses are directed to a specific CPU on multi-processor 1134 systems. 1135 1136config X86_CPUID 1137 tristate "/dev/cpu/*/cpuid - CPU information support" 1138 ---help--- 1139 This device gives processes access to the x86 CPUID instruction to 1140 be executed on a specific processor. It is a character device 1141 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1142 /dev/cpu/31/cpuid. 1143 1144choice 1145 prompt "High Memory Support" 1146 default HIGHMEM4G 1147 depends on X86_32 1148 1149config NOHIGHMEM 1150 bool "off" 1151 ---help--- 1152 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1153 However, the address space of 32-bit x86 processors is only 4 1154 Gigabytes large. That means that, if you have a large amount of 1155 physical memory, not all of it can be "permanently mapped" by the 1156 kernel. The physical memory that's not permanently mapped is called 1157 "high memory". 1158 1159 If you are compiling a kernel which will never run on a machine with 1160 more than 1 Gigabyte total physical RAM, answer "off" here (default 1161 choice and suitable for most users). This will result in a "3GB/1GB" 1162 split: 3GB are mapped so that each process sees a 3GB virtual memory 1163 space and the remaining part of the 4GB virtual memory space is used 1164 by the kernel to permanently map as much physical memory as 1165 possible. 1166 1167 If the machine has between 1 and 4 Gigabytes physical RAM, then 1168 answer "4GB" here. 1169 1170 If more than 4 Gigabytes is used then answer "64GB" here. This 1171 selection turns Intel PAE (Physical Address Extension) mode on. 1172 PAE implements 3-level paging on IA32 processors. PAE is fully 1173 supported by Linux, PAE mode is implemented on all recent Intel 1174 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1175 then the kernel will not boot on CPUs that don't support PAE! 1176 1177 The actual amount of total physical memory will either be 1178 auto detected or can be forced by using a kernel command line option 1179 such as "mem=256M". (Try "man bootparam" or see the documentation of 1180 your boot loader (lilo or loadlin) about how to pass options to the 1181 kernel at boot time.) 1182 1183 If unsure, say "off". 1184 1185config HIGHMEM4G 1186 bool "4GB" 1187 ---help--- 1188 Select this if you have a 32-bit processor and between 1 and 4 1189 gigabytes of physical RAM. 1190 1191config HIGHMEM64G 1192 bool "64GB" 1193 depends on !M486 1194 select X86_PAE 1195 ---help--- 1196 Select this if you have a 32-bit processor and more than 4 1197 gigabytes of physical RAM. 1198 1199endchoice 1200 1201choice 1202 prompt "Memory split" if EXPERT 1203 default VMSPLIT_3G 1204 depends on X86_32 1205 ---help--- 1206 Select the desired split between kernel and user memory. 1207 1208 If the address range available to the kernel is less than the 1209 physical memory installed, the remaining memory will be available 1210 as "high memory". Accessing high memory is a little more costly 1211 than low memory, as it needs to be mapped into the kernel first. 1212 Note that increasing the kernel address space limits the range 1213 available to user programs, making the address space there 1214 tighter. Selecting anything other than the default 3G/1G split 1215 will also likely make your kernel incompatible with binary-only 1216 kernel modules. 1217 1218 If you are not absolutely sure what you are doing, leave this 1219 option alone! 1220 1221 config VMSPLIT_3G 1222 bool "3G/1G user/kernel split" 1223 config VMSPLIT_3G_OPT 1224 depends on !X86_PAE 1225 bool "3G/1G user/kernel split (for full 1G low memory)" 1226 config VMSPLIT_2G 1227 bool "2G/2G user/kernel split" 1228 config VMSPLIT_2G_OPT 1229 depends on !X86_PAE 1230 bool "2G/2G user/kernel split (for full 2G low memory)" 1231 config VMSPLIT_1G 1232 bool "1G/3G user/kernel split" 1233endchoice 1234 1235config PAGE_OFFSET 1236 hex 1237 default 0xB0000000 if VMSPLIT_3G_OPT 1238 default 0x80000000 if VMSPLIT_2G 1239 default 0x78000000 if VMSPLIT_2G_OPT 1240 default 0x40000000 if VMSPLIT_1G 1241 default 0xC0000000 1242 depends on X86_32 1243 1244config HIGHMEM 1245 def_bool y 1246 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1247 1248config X86_PAE 1249 bool "PAE (Physical Address Extension) Support" 1250 depends on X86_32 && !HIGHMEM4G 1251 ---help--- 1252 PAE is required for NX support, and furthermore enables 1253 larger swapspace support for non-overcommit purposes. It 1254 has the cost of more pagetable lookup overhead, and also 1255 consumes more pagetable space per process. 1256 1257config ARCH_PHYS_ADDR_T_64BIT 1258 def_bool y 1259 depends on X86_64 || X86_PAE 1260 1261config ARCH_DMA_ADDR_T_64BIT 1262 def_bool y 1263 depends on X86_64 || HIGHMEM64G 1264 1265config DIRECT_GBPAGES 1266 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1267 default y 1268 depends on X86_64 1269 ---help--- 1270 Allow the kernel linear mapping to use 1GB pages on CPUs that 1271 support it. This can improve the kernel's performance a tiny bit by 1272 reducing TLB pressure. If in doubt, say "Y". 1273 1274# Common NUMA Features 1275config NUMA 1276 bool "Numa Memory Allocation and Scheduler Support" 1277 depends on SMP 1278 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1279 default y if X86_BIGSMP 1280 ---help--- 1281 Enable NUMA (Non Uniform Memory Access) support. 1282 1283 The kernel will try to allocate memory used by a CPU on the 1284 local memory controller of the CPU and add some more 1285 NUMA awareness to the kernel. 1286 1287 For 64-bit this is recommended if the system is Intel Core i7 1288 (or later), AMD Opteron, or EM64T NUMA. 1289 1290 For 32-bit this is only needed if you boot a 32-bit 1291 kernel on a 64-bit NUMA platform. 1292 1293 Otherwise, you should say N. 1294 1295config AMD_NUMA 1296 def_bool y 1297 prompt "Old style AMD Opteron NUMA detection" 1298 depends on X86_64 && NUMA && PCI 1299 ---help--- 1300 Enable AMD NUMA node topology detection. You should say Y here if 1301 you have a multi processor AMD system. This uses an old method to 1302 read the NUMA configuration directly from the builtin Northbridge 1303 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1304 which also takes priority if both are compiled in. 1305 1306config X86_64_ACPI_NUMA 1307 def_bool y 1308 prompt "ACPI NUMA detection" 1309 depends on X86_64 && NUMA && ACPI && PCI 1310 select ACPI_NUMA 1311 ---help--- 1312 Enable ACPI SRAT based node topology detection. 1313 1314# Some NUMA nodes have memory ranges that span 1315# other nodes. Even though a pfn is valid and 1316# between a node's start and end pfns, it may not 1317# reside on that node. See memmap_init_zone() 1318# for details. 1319config NODES_SPAN_OTHER_NODES 1320 def_bool y 1321 depends on X86_64_ACPI_NUMA 1322 1323config NUMA_EMU 1324 bool "NUMA emulation" 1325 depends on NUMA 1326 ---help--- 1327 Enable NUMA emulation. A flat machine will be split 1328 into virtual nodes when booted with "numa=fake=N", where N is the 1329 number of nodes. This is only useful for debugging. 1330 1331config NODES_SHIFT 1332 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1333 range 1 10 1334 default "10" if MAXSMP 1335 default "6" if X86_64 1336 default "3" 1337 depends on NEED_MULTIPLE_NODES 1338 ---help--- 1339 Specify the maximum number of NUMA Nodes available on the target 1340 system. Increases memory reserved to accommodate various tables. 1341 1342config ARCH_HAVE_MEMORY_PRESENT 1343 def_bool y 1344 depends on X86_32 && DISCONTIGMEM 1345 1346config NEED_NODE_MEMMAP_SIZE 1347 def_bool y 1348 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1349 1350config ARCH_FLATMEM_ENABLE 1351 def_bool y 1352 depends on X86_32 && !NUMA 1353 1354config ARCH_DISCONTIGMEM_ENABLE 1355 def_bool y 1356 depends on NUMA && X86_32 1357 1358config ARCH_DISCONTIGMEM_DEFAULT 1359 def_bool y 1360 depends on NUMA && X86_32 1361 1362config ARCH_SPARSEMEM_ENABLE 1363 def_bool y 1364 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1365 select SPARSEMEM_STATIC if X86_32 1366 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1367 1368config ARCH_SPARSEMEM_DEFAULT 1369 def_bool y 1370 depends on X86_64 1371 1372config ARCH_SELECT_MEMORY_MODEL 1373 def_bool y 1374 depends on ARCH_SPARSEMEM_ENABLE 1375 1376config ARCH_MEMORY_PROBE 1377 bool "Enable sysfs memory/probe interface" 1378 depends on X86_64 && MEMORY_HOTPLUG 1379 help 1380 This option enables a sysfs memory/probe interface for testing. 1381 See Documentation/memory-hotplug.txt for more information. 1382 If you are unsure how to answer this question, answer N. 1383 1384config ARCH_PROC_KCORE_TEXT 1385 def_bool y 1386 depends on X86_64 && PROC_KCORE 1387 1388config ILLEGAL_POINTER_VALUE 1389 hex 1390 default 0 if X86_32 1391 default 0xdead000000000000 if X86_64 1392 1393source "mm/Kconfig" 1394 1395config HIGHPTE 1396 bool "Allocate 3rd-level pagetables from highmem" 1397 depends on HIGHMEM 1398 ---help--- 1399 The VM uses one page table entry for each page of physical memory. 1400 For systems with a lot of RAM, this can be wasteful of precious 1401 low memory. Setting this option will put user-space page table 1402 entries in high memory. 1403 1404config X86_CHECK_BIOS_CORRUPTION 1405 bool "Check for low memory corruption" 1406 ---help--- 1407 Periodically check for memory corruption in low memory, which 1408 is suspected to be caused by BIOS. Even when enabled in the 1409 configuration, it is disabled at runtime. Enable it by 1410 setting "memory_corruption_check=1" on the kernel command 1411 line. By default it scans the low 64k of memory every 60 1412 seconds; see the memory_corruption_check_size and 1413 memory_corruption_check_period parameters in 1414 Documentation/kernel-parameters.txt to adjust this. 1415 1416 When enabled with the default parameters, this option has 1417 almost no overhead, as it reserves a relatively small amount 1418 of memory and scans it infrequently. It both detects corruption 1419 and prevents it from affecting the running system. 1420 1421 It is, however, intended as a diagnostic tool; if repeatable 1422 BIOS-originated corruption always affects the same memory, 1423 you can use memmap= to prevent the kernel from using that 1424 memory. 1425 1426config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1427 bool "Set the default setting of memory_corruption_check" 1428 depends on X86_CHECK_BIOS_CORRUPTION 1429 default y 1430 ---help--- 1431 Set whether the default state of memory_corruption_check is 1432 on or off. 1433 1434config X86_RESERVE_LOW 1435 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1436 default 64 1437 range 4 640 1438 ---help--- 1439 Specify the amount of low memory to reserve for the BIOS. 1440 1441 The first page contains BIOS data structures that the kernel 1442 must not use, so that page must always be reserved. 1443 1444 By default we reserve the first 64K of physical RAM, as a 1445 number of BIOSes are known to corrupt that memory range 1446 during events such as suspend/resume or monitor cable 1447 insertion, so it must not be used by the kernel. 1448 1449 You can set this to 4 if you are absolutely sure that you 1450 trust the BIOS to get all its memory reservations and usages 1451 right. If you know your BIOS have problems beyond the 1452 default 64K area, you can set this to 640 to avoid using the 1453 entire low memory range. 1454 1455 If you have doubts about the BIOS (e.g. suspend/resume does 1456 not work or there's kernel crashes after certain hardware 1457 hotplug events) then you might want to enable 1458 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1459 typical corruption patterns. 1460 1461 Leave this to the default value of 64 if you are unsure. 1462 1463config MATH_EMULATION 1464 bool 1465 prompt "Math emulation" if X86_32 1466 ---help--- 1467 Linux can emulate a math coprocessor (used for floating point 1468 operations) if you don't have one. 486DX and Pentium processors have 1469 a math coprocessor built in, 486SX and 386 do not, unless you added 1470 a 487DX or 387, respectively. (The messages during boot time can 1471 give you some hints here ["man dmesg"].) Everyone needs either a 1472 coprocessor or this emulation. 1473 1474 If you don't have a math coprocessor, you need to say Y here; if you 1475 say Y here even though you have a coprocessor, the coprocessor will 1476 be used nevertheless. (This behavior can be changed with the kernel 1477 command line option "no387", which comes handy if your coprocessor 1478 is broken. Try "man bootparam" or see the documentation of your boot 1479 loader (lilo or loadlin) about how to pass options to the kernel at 1480 boot time.) This means that it is a good idea to say Y here if you 1481 intend to use this kernel on different machines. 1482 1483 More information about the internals of the Linux math coprocessor 1484 emulation can be found in <file:arch/x86/math-emu/README>. 1485 1486 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1487 kernel, it won't hurt. 1488 1489config MTRR 1490 def_bool y 1491 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1492 ---help--- 1493 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1494 the Memory Type Range Registers (MTRRs) may be used to control 1495 processor access to memory ranges. This is most useful if you have 1496 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1497 allows bus write transfers to be combined into a larger transfer 1498 before bursting over the PCI/AGP bus. This can increase performance 1499 of image write operations 2.5 times or more. Saying Y here creates a 1500 /proc/mtrr file which may be used to manipulate your processor's 1501 MTRRs. Typically the X server should use this. 1502 1503 This code has a reasonably generic interface so that similar 1504 control registers on other processors can be easily supported 1505 as well: 1506 1507 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1508 Registers (ARRs) which provide a similar functionality to MTRRs. For 1509 these, the ARRs are used to emulate the MTRRs. 1510 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1511 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1512 write-combining. All of these processors are supported by this code 1513 and it makes sense to say Y here if you have one of them. 1514 1515 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1516 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1517 can lead to all sorts of problems, so it's good to say Y here. 1518 1519 You can safely say Y even if your machine doesn't have MTRRs, you'll 1520 just add about 9 KB to your kernel. 1521 1522 See <file:Documentation/x86/mtrr.txt> for more information. 1523 1524config MTRR_SANITIZER 1525 def_bool y 1526 prompt "MTRR cleanup support" 1527 depends on MTRR 1528 ---help--- 1529 Convert MTRR layout from continuous to discrete, so X drivers can 1530 add writeback entries. 1531 1532 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1533 The largest mtrr entry size for a continuous block can be set with 1534 mtrr_chunk_size. 1535 1536 If unsure, say Y. 1537 1538config MTRR_SANITIZER_ENABLE_DEFAULT 1539 int "MTRR cleanup enable value (0-1)" 1540 range 0 1 1541 default "0" 1542 depends on MTRR_SANITIZER 1543 ---help--- 1544 Enable mtrr cleanup default value 1545 1546config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1547 int "MTRR cleanup spare reg num (0-7)" 1548 range 0 7 1549 default "1" 1550 depends on MTRR_SANITIZER 1551 ---help--- 1552 mtrr cleanup spare entries default, it can be changed via 1553 mtrr_spare_reg_nr=N on the kernel command line. 1554 1555config X86_PAT 1556 def_bool y 1557 prompt "x86 PAT support" if EXPERT 1558 depends on MTRR 1559 ---help--- 1560 Use PAT attributes to setup page level cache control. 1561 1562 PATs are the modern equivalents of MTRRs and are much more 1563 flexible than MTRRs. 1564 1565 Say N here if you see bootup problems (boot crash, boot hang, 1566 spontaneous reboots) or a non-working video driver. 1567 1568 If unsure, say Y. 1569 1570config ARCH_USES_PG_UNCACHED 1571 def_bool y 1572 depends on X86_PAT 1573 1574config ARCH_RANDOM 1575 def_bool y 1576 prompt "x86 architectural random number generator" if EXPERT 1577 ---help--- 1578 Enable the x86 architectural RDRAND instruction 1579 (Intel Bull Mountain technology) to generate random numbers. 1580 If supported, this is a high bandwidth, cryptographically 1581 secure hardware random number generator. 1582 1583config X86_SMAP 1584 def_bool y 1585 prompt "Supervisor Mode Access Prevention" if EXPERT 1586 ---help--- 1587 Supervisor Mode Access Prevention (SMAP) is a security 1588 feature in newer Intel processors. There is a small 1589 performance cost if this enabled and turned on; there is 1590 also a small increase in the kernel size if this is enabled. 1591 1592 If unsure, say Y. 1593 1594config EFI 1595 bool "EFI runtime service support" 1596 depends on ACPI 1597 select UCS2_STRING 1598 select EFI_RUNTIME_WRAPPERS 1599 ---help--- 1600 This enables the kernel to use EFI runtime services that are 1601 available (such as the EFI variable services). 1602 1603 This option is only useful on systems that have EFI firmware. 1604 In addition, you should use the latest ELILO loader available 1605 at <http://elilo.sourceforge.net> in order to take advantage 1606 of EFI runtime services. However, even with this option, the 1607 resultant kernel should continue to boot on existing non-EFI 1608 platforms. 1609 1610config EFI_STUB 1611 bool "EFI stub support" 1612 depends on EFI && !X86_USE_3DNOW 1613 select RELOCATABLE 1614 ---help--- 1615 This kernel feature allows a bzImage to be loaded directly 1616 by EFI firmware without the use of a bootloader. 1617 1618 See Documentation/efi-stub.txt for more information. 1619 1620config EFI_MIXED 1621 bool "EFI mixed-mode support" 1622 depends on EFI_STUB && X86_64 1623 ---help--- 1624 Enabling this feature allows a 64-bit kernel to be booted 1625 on a 32-bit firmware, provided that your CPU supports 64-bit 1626 mode. 1627 1628 Note that it is not possible to boot a mixed-mode enabled 1629 kernel via the EFI boot stub - a bootloader that supports 1630 the EFI handover protocol must be used. 1631 1632 If unsure, say N. 1633 1634config SECCOMP 1635 def_bool y 1636 prompt "Enable seccomp to safely compute untrusted bytecode" 1637 ---help--- 1638 This kernel feature is useful for number crunching applications 1639 that may need to compute untrusted bytecode during their 1640 execution. By using pipes or other transports made available to 1641 the process as file descriptors supporting the read/write 1642 syscalls, it's possible to isolate those applications in 1643 their own address space using seccomp. Once seccomp is 1644 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1645 and the task is only allowed to execute a few safe syscalls 1646 defined by each seccomp mode. 1647 1648 If unsure, say Y. Only embedded should say N here. 1649 1650source kernel/Kconfig.hz 1651 1652config KEXEC 1653 bool "kexec system call" 1654 ---help--- 1655 kexec is a system call that implements the ability to shutdown your 1656 current kernel, and to start another kernel. It is like a reboot 1657 but it is independent of the system firmware. And like a reboot 1658 you can start any kernel with it, not just Linux. 1659 1660 The name comes from the similarity to the exec system call. 1661 1662 It is an ongoing process to be certain the hardware in a machine 1663 is properly shutdown, so do not be surprised if this code does not 1664 initially work for you. As of this writing the exact hardware 1665 interface is strongly in flux, so no good recommendation can be 1666 made. 1667 1668config KEXEC_FILE 1669 bool "kexec file based system call" 1670 select BUILD_BIN2C 1671 depends on KEXEC 1672 depends on X86_64 1673 depends on CRYPTO=y 1674 depends on CRYPTO_SHA256=y 1675 ---help--- 1676 This is new version of kexec system call. This system call is 1677 file based and takes file descriptors as system call argument 1678 for kernel and initramfs as opposed to list of segments as 1679 accepted by previous system call. 1680 1681config KEXEC_VERIFY_SIG 1682 bool "Verify kernel signature during kexec_file_load() syscall" 1683 depends on KEXEC_FILE 1684 ---help--- 1685 This option makes kernel signature verification mandatory for 1686 kexec_file_load() syscall. If kernel is signature can not be 1687 verified, kexec_file_load() will fail. 1688 1689 This option enforces signature verification at generic level. 1690 One needs to enable signature verification for type of kernel 1691 image being loaded to make sure it works. For example, enable 1692 bzImage signature verification option to be able to load and 1693 verify signatures of bzImage. Otherwise kernel loading will fail. 1694 1695config KEXEC_BZIMAGE_VERIFY_SIG 1696 bool "Enable bzImage signature verification support" 1697 depends on KEXEC_VERIFY_SIG 1698 depends on SIGNED_PE_FILE_VERIFICATION 1699 select SYSTEM_TRUSTED_KEYRING 1700 ---help--- 1701 Enable bzImage signature verification support. 1702 1703config CRASH_DUMP 1704 bool "kernel crash dumps" 1705 depends on X86_64 || (X86_32 && HIGHMEM) 1706 ---help--- 1707 Generate crash dump after being started by kexec. 1708 This should be normally only set in special crash dump kernels 1709 which are loaded in the main kernel with kexec-tools into 1710 a specially reserved region and then later executed after 1711 a crash by kdump/kexec. The crash dump kernel must be compiled 1712 to a memory address not used by the main kernel or BIOS using 1713 PHYSICAL_START, or it must be built as a relocatable image 1714 (CONFIG_RELOCATABLE=y). 1715 For more details see Documentation/kdump/kdump.txt 1716 1717config KEXEC_JUMP 1718 bool "kexec jump" 1719 depends on KEXEC && HIBERNATION 1720 ---help--- 1721 Jump between original kernel and kexeced kernel and invoke 1722 code in physical address mode via KEXEC 1723 1724config PHYSICAL_START 1725 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1726 default "0x1000000" 1727 ---help--- 1728 This gives the physical address where the kernel is loaded. 1729 1730 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1731 bzImage will decompress itself to above physical address and 1732 run from there. Otherwise, bzImage will run from the address where 1733 it has been loaded by the boot loader and will ignore above physical 1734 address. 1735 1736 In normal kdump cases one does not have to set/change this option 1737 as now bzImage can be compiled as a completely relocatable image 1738 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1739 address. This option is mainly useful for the folks who don't want 1740 to use a bzImage for capturing the crash dump and want to use a 1741 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1742 to be specifically compiled to run from a specific memory area 1743 (normally a reserved region) and this option comes handy. 1744 1745 So if you are using bzImage for capturing the crash dump, 1746 leave the value here unchanged to 0x1000000 and set 1747 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1748 for capturing the crash dump change this value to start of 1749 the reserved region. In other words, it can be set based on 1750 the "X" value as specified in the "crashkernel=YM@XM" 1751 command line boot parameter passed to the panic-ed 1752 kernel. Please take a look at Documentation/kdump/kdump.txt 1753 for more details about crash dumps. 1754 1755 Usage of bzImage for capturing the crash dump is recommended as 1756 one does not have to build two kernels. Same kernel can be used 1757 as production kernel and capture kernel. Above option should have 1758 gone away after relocatable bzImage support is introduced. But it 1759 is present because there are users out there who continue to use 1760 vmlinux for dump capture. This option should go away down the 1761 line. 1762 1763 Don't change this unless you know what you are doing. 1764 1765config RELOCATABLE 1766 bool "Build a relocatable kernel" 1767 default y 1768 ---help--- 1769 This builds a kernel image that retains relocation information 1770 so it can be loaded someplace besides the default 1MB. 1771 The relocations tend to make the kernel binary about 10% larger, 1772 but are discarded at runtime. 1773 1774 One use is for the kexec on panic case where the recovery kernel 1775 must live at a different physical address than the primary 1776 kernel. 1777 1778 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1779 it has been loaded at and the compile time physical address 1780 (CONFIG_PHYSICAL_START) is used as the minimum location. 1781 1782config RANDOMIZE_BASE 1783 bool "Randomize the address of the kernel image" 1784 depends on RELOCATABLE 1785 default n 1786 ---help--- 1787 Randomizes the physical and virtual address at which the 1788 kernel image is decompressed, as a security feature that 1789 deters exploit attempts relying on knowledge of the location 1790 of kernel internals. 1791 1792 Entropy is generated using the RDRAND instruction if it is 1793 supported. If RDTSC is supported, it is used as well. If 1794 neither RDRAND nor RDTSC are supported, then randomness is 1795 read from the i8254 timer. 1796 1797 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1798 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1799 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1800 minimum of 2MiB, only 10 bits of entropy is theoretically 1801 possible. At best, due to page table layouts, 64-bit can use 1802 9 bits of entropy and 32-bit uses 8 bits. 1803 1804 If unsure, say N. 1805 1806config RANDOMIZE_BASE_MAX_OFFSET 1807 hex "Maximum kASLR offset allowed" if EXPERT 1808 depends on RANDOMIZE_BASE 1809 range 0x0 0x20000000 if X86_32 1810 default "0x20000000" if X86_32 1811 range 0x0 0x40000000 if X86_64 1812 default "0x40000000" if X86_64 1813 ---help--- 1814 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1815 memory is used to determine the maximal offset in bytes that will 1816 be applied to the kernel when kernel Address Space Layout 1817 Randomization (kASLR) is active. This must be a multiple of 1818 PHYSICAL_ALIGN. 1819 1820 On 32-bit this is limited to 512MiB by page table layouts. The 1821 default is 512MiB. 1822 1823 On 64-bit this is limited by how the kernel fixmap page table is 1824 positioned, so this cannot be larger than 1GiB currently. Without 1825 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1826 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1827 modules area will shrink to compensate, up to the current maximum 1828 1GiB to 1GiB split. The default is 1GiB. 1829 1830 If unsure, leave at the default value. 1831 1832# Relocation on x86 needs some additional build support 1833config X86_NEED_RELOCS 1834 def_bool y 1835 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1836 1837config PHYSICAL_ALIGN 1838 hex "Alignment value to which kernel should be aligned" 1839 default "0x200000" 1840 range 0x2000 0x1000000 if X86_32 1841 range 0x200000 0x1000000 if X86_64 1842 ---help--- 1843 This value puts the alignment restrictions on physical address 1844 where kernel is loaded and run from. Kernel is compiled for an 1845 address which meets above alignment restriction. 1846 1847 If bootloader loads the kernel at a non-aligned address and 1848 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1849 address aligned to above value and run from there. 1850 1851 If bootloader loads the kernel at a non-aligned address and 1852 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1853 load address and decompress itself to the address it has been 1854 compiled for and run from there. The address for which kernel is 1855 compiled already meets above alignment restrictions. Hence the 1856 end result is that kernel runs from a physical address meeting 1857 above alignment restrictions. 1858 1859 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1860 this value must be a multiple of 0x200000. 1861 1862 Don't change this unless you know what you are doing. 1863 1864config HOTPLUG_CPU 1865 bool "Support for hot-pluggable CPUs" 1866 depends on SMP 1867 ---help--- 1868 Say Y here to allow turning CPUs off and on. CPUs can be 1869 controlled through /sys/devices/system/cpu. 1870 ( Note: power management support will enable this option 1871 automatically on SMP systems. ) 1872 Say N if you want to disable CPU hotplug. 1873 1874config BOOTPARAM_HOTPLUG_CPU0 1875 bool "Set default setting of cpu0_hotpluggable" 1876 default n 1877 depends on HOTPLUG_CPU 1878 ---help--- 1879 Set whether default state of cpu0_hotpluggable is on or off. 1880 1881 Say Y here to enable CPU0 hotplug by default. If this switch 1882 is turned on, there is no need to give cpu0_hotplug kernel 1883 parameter and the CPU0 hotplug feature is enabled by default. 1884 1885 Please note: there are two known CPU0 dependencies if you want 1886 to enable the CPU0 hotplug feature either by this switch or by 1887 cpu0_hotplug kernel parameter. 1888 1889 First, resume from hibernate or suspend always starts from CPU0. 1890 So hibernate and suspend are prevented if CPU0 is offline. 1891 1892 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1893 offline if any interrupt can not migrate out of CPU0. There may 1894 be other CPU0 dependencies. 1895 1896 Please make sure the dependencies are under your control before 1897 you enable this feature. 1898 1899 Say N if you don't want to enable CPU0 hotplug feature by default. 1900 You still can enable the CPU0 hotplug feature at boot by kernel 1901 parameter cpu0_hotplug. 1902 1903config DEBUG_HOTPLUG_CPU0 1904 def_bool n 1905 prompt "Debug CPU0 hotplug" 1906 depends on HOTPLUG_CPU 1907 ---help--- 1908 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1909 soon as possible and boots up userspace with CPU0 offlined. User 1910 can online CPU0 back after boot time. 1911 1912 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1913 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1914 compilation or giving cpu0_hotplug kernel parameter at boot. 1915 1916 If unsure, say N. 1917 1918config COMPAT_VDSO 1919 def_bool n 1920 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 1921 depends on X86_32 || IA32_EMULATION 1922 ---help--- 1923 Certain buggy versions of glibc will crash if they are 1924 presented with a 32-bit vDSO that is not mapped at the address 1925 indicated in its segment table. 1926 1927 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 1928 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 1929 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 1930 the only released version with the bug, but OpenSUSE 9 1931 contains a buggy "glibc 2.3.2". 1932 1933 The symptom of the bug is that everything crashes on startup, saying: 1934 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 1935 1936 Saying Y here changes the default value of the vdso32 boot 1937 option from 1 to 0, which turns off the 32-bit vDSO entirely. 1938 This works around the glibc bug but hurts performance. 1939 1940 If unsure, say N: if you are compiling your own kernel, you 1941 are unlikely to be using a buggy version of glibc. 1942 1943config CMDLINE_BOOL 1944 bool "Built-in kernel command line" 1945 ---help--- 1946 Allow for specifying boot arguments to the kernel at 1947 build time. On some systems (e.g. embedded ones), it is 1948 necessary or convenient to provide some or all of the 1949 kernel boot arguments with the kernel itself (that is, 1950 to not rely on the boot loader to provide them.) 1951 1952 To compile command line arguments into the kernel, 1953 set this option to 'Y', then fill in the 1954 the boot arguments in CONFIG_CMDLINE. 1955 1956 Systems with fully functional boot loaders (i.e. non-embedded) 1957 should leave this option set to 'N'. 1958 1959config CMDLINE 1960 string "Built-in kernel command string" 1961 depends on CMDLINE_BOOL 1962 default "" 1963 ---help--- 1964 Enter arguments here that should be compiled into the kernel 1965 image and used at boot time. If the boot loader provides a 1966 command line at boot time, it is appended to this string to 1967 form the full kernel command line, when the system boots. 1968 1969 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1970 change this behavior. 1971 1972 In most cases, the command line (whether built-in or provided 1973 by the boot loader) should specify the device for the root 1974 file system. 1975 1976config CMDLINE_OVERRIDE 1977 bool "Built-in command line overrides boot loader arguments" 1978 depends on CMDLINE_BOOL 1979 ---help--- 1980 Set this option to 'Y' to have the kernel ignore the boot loader 1981 command line, and use ONLY the built-in command line. 1982 1983 This is used to work around broken boot loaders. This should 1984 be set to 'N' under normal conditions. 1985 1986endmenu 1987 1988config ARCH_ENABLE_MEMORY_HOTPLUG 1989 def_bool y 1990 depends on X86_64 || (X86_32 && HIGHMEM) 1991 1992config ARCH_ENABLE_MEMORY_HOTREMOVE 1993 def_bool y 1994 depends on MEMORY_HOTPLUG 1995 1996config USE_PERCPU_NUMA_NODE_ID 1997 def_bool y 1998 depends on NUMA 1999 2000config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2001 def_bool y 2002 depends on X86_64 || X86_PAE 2003 2004config ARCH_ENABLE_HUGEPAGE_MIGRATION 2005 def_bool y 2006 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2007 2008menu "Power management and ACPI options" 2009 2010config ARCH_HIBERNATION_HEADER 2011 def_bool y 2012 depends on X86_64 && HIBERNATION 2013 2014source "kernel/power/Kconfig" 2015 2016source "drivers/acpi/Kconfig" 2017 2018source "drivers/sfi/Kconfig" 2019 2020config X86_APM_BOOT 2021 def_bool y 2022 depends on APM 2023 2024menuconfig APM 2025 tristate "APM (Advanced Power Management) BIOS support" 2026 depends on X86_32 && PM_SLEEP 2027 ---help--- 2028 APM is a BIOS specification for saving power using several different 2029 techniques. This is mostly useful for battery powered laptops with 2030 APM compliant BIOSes. If you say Y here, the system time will be 2031 reset after a RESUME operation, the /proc/apm device will provide 2032 battery status information, and user-space programs will receive 2033 notification of APM "events" (e.g. battery status change). 2034 2035 If you select "Y" here, you can disable actual use of the APM 2036 BIOS by passing the "apm=off" option to the kernel at boot time. 2037 2038 Note that the APM support is almost completely disabled for 2039 machines with more than one CPU. 2040 2041 In order to use APM, you will need supporting software. For location 2042 and more information, read <file:Documentation/power/apm-acpi.txt> 2043 and the Battery Powered Linux mini-HOWTO, available from 2044 <http://www.tldp.org/docs.html#howto>. 2045 2046 This driver does not spin down disk drives (see the hdparm(8) 2047 manpage ("man 8 hdparm") for that), and it doesn't turn off 2048 VESA-compliant "green" monitors. 2049 2050 This driver does not support the TI 4000M TravelMate and the ACER 2051 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2052 desktop machines also don't have compliant BIOSes, and this driver 2053 may cause those machines to panic during the boot phase. 2054 2055 Generally, if you don't have a battery in your machine, there isn't 2056 much point in using this driver and you should say N. If you get 2057 random kernel OOPSes or reboots that don't seem to be related to 2058 anything, try disabling/enabling this option (or disabling/enabling 2059 APM in your BIOS). 2060 2061 Some other things you should try when experiencing seemingly random, 2062 "weird" problems: 2063 2064 1) make sure that you have enough swap space and that it is 2065 enabled. 2066 2) pass the "no-hlt" option to the kernel 2067 3) switch on floating point emulation in the kernel and pass 2068 the "no387" option to the kernel 2069 4) pass the "floppy=nodma" option to the kernel 2070 5) pass the "mem=4M" option to the kernel (thereby disabling 2071 all but the first 4 MB of RAM) 2072 6) make sure that the CPU is not over clocked. 2073 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2074 8) disable the cache from your BIOS settings 2075 9) install a fan for the video card or exchange video RAM 2076 10) install a better fan for the CPU 2077 11) exchange RAM chips 2078 12) exchange the motherboard. 2079 2080 To compile this driver as a module, choose M here: the 2081 module will be called apm. 2082 2083if APM 2084 2085config APM_IGNORE_USER_SUSPEND 2086 bool "Ignore USER SUSPEND" 2087 ---help--- 2088 This option will ignore USER SUSPEND requests. On machines with a 2089 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2090 series notebooks, it is necessary to say Y because of a BIOS bug. 2091 2092config APM_DO_ENABLE 2093 bool "Enable PM at boot time" 2094 ---help--- 2095 Enable APM features at boot time. From page 36 of the APM BIOS 2096 specification: "When disabled, the APM BIOS does not automatically 2097 power manage devices, enter the Standby State, enter the Suspend 2098 State, or take power saving steps in response to CPU Idle calls." 2099 This driver will make CPU Idle calls when Linux is idle (unless this 2100 feature is turned off -- see "Do CPU IDLE calls", below). This 2101 should always save battery power, but more complicated APM features 2102 will be dependent on your BIOS implementation. You may need to turn 2103 this option off if your computer hangs at boot time when using APM 2104 support, or if it beeps continuously instead of suspending. Turn 2105 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2106 T400CDT. This is off by default since most machines do fine without 2107 this feature. 2108 2109config APM_CPU_IDLE 2110 depends on CPU_IDLE 2111 bool "Make CPU Idle calls when idle" 2112 ---help--- 2113 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2114 On some machines, this can activate improved power savings, such as 2115 a slowed CPU clock rate, when the machine is idle. These idle calls 2116 are made after the idle loop has run for some length of time (e.g., 2117 333 mS). On some machines, this will cause a hang at boot time or 2118 whenever the CPU becomes idle. (On machines with more than one CPU, 2119 this option does nothing.) 2120 2121config APM_DISPLAY_BLANK 2122 bool "Enable console blanking using APM" 2123 ---help--- 2124 Enable console blanking using the APM. Some laptops can use this to 2125 turn off the LCD backlight when the screen blanker of the Linux 2126 virtual console blanks the screen. Note that this is only used by 2127 the virtual console screen blanker, and won't turn off the backlight 2128 when using the X Window system. This also doesn't have anything to 2129 do with your VESA-compliant power-saving monitor. Further, this 2130 option doesn't work for all laptops -- it might not turn off your 2131 backlight at all, or it might print a lot of errors to the console, 2132 especially if you are using gpm. 2133 2134config APM_ALLOW_INTS 2135 bool "Allow interrupts during APM BIOS calls" 2136 ---help--- 2137 Normally we disable external interrupts while we are making calls to 2138 the APM BIOS as a measure to lessen the effects of a badly behaving 2139 BIOS implementation. The BIOS should reenable interrupts if it 2140 needs to. Unfortunately, some BIOSes do not -- especially those in 2141 many of the newer IBM Thinkpads. If you experience hangs when you 2142 suspend, try setting this to Y. Otherwise, say N. 2143 2144endif # APM 2145 2146source "drivers/cpufreq/Kconfig" 2147 2148source "drivers/cpuidle/Kconfig" 2149 2150source "drivers/idle/Kconfig" 2151 2152endmenu 2153 2154 2155menu "Bus options (PCI etc.)" 2156 2157config PCI 2158 bool "PCI support" 2159 default y 2160 ---help--- 2161 Find out whether you have a PCI motherboard. PCI is the name of a 2162 bus system, i.e. the way the CPU talks to the other stuff inside 2163 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2164 VESA. If you have PCI, say Y, otherwise N. 2165 2166choice 2167 prompt "PCI access mode" 2168 depends on X86_32 && PCI 2169 default PCI_GOANY 2170 ---help--- 2171 On PCI systems, the BIOS can be used to detect the PCI devices and 2172 determine their configuration. However, some old PCI motherboards 2173 have BIOS bugs and may crash if this is done. Also, some embedded 2174 PCI-based systems don't have any BIOS at all. Linux can also try to 2175 detect the PCI hardware directly without using the BIOS. 2176 2177 With this option, you can specify how Linux should detect the 2178 PCI devices. If you choose "BIOS", the BIOS will be used, 2179 if you choose "Direct", the BIOS won't be used, and if you 2180 choose "MMConfig", then PCI Express MMCONFIG will be used. 2181 If you choose "Any", the kernel will try MMCONFIG, then the 2182 direct access method and falls back to the BIOS if that doesn't 2183 work. If unsure, go with the default, which is "Any". 2184 2185config PCI_GOBIOS 2186 bool "BIOS" 2187 2188config PCI_GOMMCONFIG 2189 bool "MMConfig" 2190 2191config PCI_GODIRECT 2192 bool "Direct" 2193 2194config PCI_GOOLPC 2195 bool "OLPC XO-1" 2196 depends on OLPC 2197 2198config PCI_GOANY 2199 bool "Any" 2200 2201endchoice 2202 2203config PCI_BIOS 2204 def_bool y 2205 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2206 2207# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2208config PCI_DIRECT 2209 def_bool y 2210 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2211 2212config PCI_MMCONFIG 2213 def_bool y 2214 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2215 2216config PCI_OLPC 2217 def_bool y 2218 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2219 2220config PCI_XEN 2221 def_bool y 2222 depends on PCI && XEN 2223 select SWIOTLB_XEN 2224 2225config PCI_DOMAINS 2226 def_bool y 2227 depends on PCI 2228 2229config PCI_MMCONFIG 2230 bool "Support mmconfig PCI config space access" 2231 depends on X86_64 && PCI && ACPI 2232 2233config PCI_CNB20LE_QUIRK 2234 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2235 depends on PCI 2236 help 2237 Read the PCI windows out of the CNB20LE host bridge. This allows 2238 PCI hotplug to work on systems with the CNB20LE chipset which do 2239 not have ACPI. 2240 2241 There's no public spec for this chipset, and this functionality 2242 is known to be incomplete. 2243 2244 You should say N unless you know you need this. 2245 2246source "drivers/pci/pcie/Kconfig" 2247 2248source "drivers/pci/Kconfig" 2249 2250# x86_64 have no ISA slots, but can have ISA-style DMA. 2251config ISA_DMA_API 2252 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2253 default y 2254 help 2255 Enables ISA-style DMA support for devices requiring such controllers. 2256 If unsure, say Y. 2257 2258if X86_32 2259 2260config ISA 2261 bool "ISA support" 2262 ---help--- 2263 Find out whether you have ISA slots on your motherboard. ISA is the 2264 name of a bus system, i.e. the way the CPU talks to the other stuff 2265 inside your box. Other bus systems are PCI, EISA, MicroChannel 2266 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2267 newer boards don't support it. If you have ISA, say Y, otherwise N. 2268 2269config EISA 2270 bool "EISA support" 2271 depends on ISA 2272 ---help--- 2273 The Extended Industry Standard Architecture (EISA) bus was 2274 developed as an open alternative to the IBM MicroChannel bus. 2275 2276 The EISA bus provided some of the features of the IBM MicroChannel 2277 bus while maintaining backward compatibility with cards made for 2278 the older ISA bus. The EISA bus saw limited use between 1988 and 2279 1995 when it was made obsolete by the PCI bus. 2280 2281 Say Y here if you are building a kernel for an EISA-based machine. 2282 2283 Otherwise, say N. 2284 2285source "drivers/eisa/Kconfig" 2286 2287config SCx200 2288 tristate "NatSemi SCx200 support" 2289 ---help--- 2290 This provides basic support for National Semiconductor's 2291 (now AMD's) Geode processors. The driver probes for the 2292 PCI-IDs of several on-chip devices, so its a good dependency 2293 for other scx200_* drivers. 2294 2295 If compiled as a module, the driver is named scx200. 2296 2297config SCx200HR_TIMER 2298 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2299 depends on SCx200 2300 default y 2301 ---help--- 2302 This driver provides a clocksource built upon the on-chip 2303 27MHz high-resolution timer. Its also a workaround for 2304 NSC Geode SC-1100's buggy TSC, which loses time when the 2305 processor goes idle (as is done by the scheduler). The 2306 other workaround is idle=poll boot option. 2307 2308config OLPC 2309 bool "One Laptop Per Child support" 2310 depends on !X86_PAE 2311 select GPIOLIB 2312 select OF 2313 select OF_PROMTREE 2314 select IRQ_DOMAIN 2315 ---help--- 2316 Add support for detecting the unique features of the OLPC 2317 XO hardware. 2318 2319config OLPC_XO1_PM 2320 bool "OLPC XO-1 Power Management" 2321 depends on OLPC && MFD_CS5535 && PM_SLEEP 2322 select MFD_CORE 2323 ---help--- 2324 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2325 2326config OLPC_XO1_RTC 2327 bool "OLPC XO-1 Real Time Clock" 2328 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2329 ---help--- 2330 Add support for the XO-1 real time clock, which can be used as a 2331 programmable wakeup source. 2332 2333config OLPC_XO1_SCI 2334 bool "OLPC XO-1 SCI extras" 2335 depends on OLPC && OLPC_XO1_PM 2336 depends on INPUT=y 2337 select POWER_SUPPLY 2338 select GPIO_CS5535 2339 select MFD_CORE 2340 ---help--- 2341 Add support for SCI-based features of the OLPC XO-1 laptop: 2342 - EC-driven system wakeups 2343 - Power button 2344 - Ebook switch 2345 - Lid switch 2346 - AC adapter status updates 2347 - Battery status updates 2348 2349config OLPC_XO15_SCI 2350 bool "OLPC XO-1.5 SCI extras" 2351 depends on OLPC && ACPI 2352 select POWER_SUPPLY 2353 ---help--- 2354 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2355 - EC-driven system wakeups 2356 - AC adapter status updates 2357 - Battery status updates 2358 2359config ALIX 2360 bool "PCEngines ALIX System Support (LED setup)" 2361 select GPIOLIB 2362 ---help--- 2363 This option enables system support for the PCEngines ALIX. 2364 At present this just sets up LEDs for GPIO control on 2365 ALIX2/3/6 boards. However, other system specific setup should 2366 get added here. 2367 2368 Note: You must still enable the drivers for GPIO and LED support 2369 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2370 2371 Note: You have to set alix.force=1 for boards with Award BIOS. 2372 2373config NET5501 2374 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2375 select GPIOLIB 2376 ---help--- 2377 This option enables system support for the Soekris Engineering net5501. 2378 2379config GEOS 2380 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2381 select GPIOLIB 2382 depends on DMI 2383 ---help--- 2384 This option enables system support for the Traverse Technologies GEOS. 2385 2386config TS5500 2387 bool "Technologic Systems TS-5500 platform support" 2388 depends on MELAN 2389 select CHECK_SIGNATURE 2390 select NEW_LEDS 2391 select LEDS_CLASS 2392 ---help--- 2393 This option enables system support for the Technologic Systems TS-5500. 2394 2395endif # X86_32 2396 2397config AMD_NB 2398 def_bool y 2399 depends on CPU_SUP_AMD && PCI 2400 2401source "drivers/pcmcia/Kconfig" 2402 2403source "drivers/pci/hotplug/Kconfig" 2404 2405config RAPIDIO 2406 tristate "RapidIO support" 2407 depends on PCI 2408 default n 2409 help 2410 If enabled this option will include drivers and the core 2411 infrastructure code to support RapidIO interconnect devices. 2412 2413source "drivers/rapidio/Kconfig" 2414 2415config X86_SYSFB 2416 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2417 help 2418 Firmwares often provide initial graphics framebuffers so the BIOS, 2419 bootloader or kernel can show basic video-output during boot for 2420 user-guidance and debugging. Historically, x86 used the VESA BIOS 2421 Extensions and EFI-framebuffers for this, which are mostly limited 2422 to x86. 2423 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2424 framebuffers so the new generic system-framebuffer drivers can be 2425 used on x86. If the framebuffer is not compatible with the generic 2426 modes, it is adverticed as fallback platform framebuffer so legacy 2427 drivers like efifb, vesafb and uvesafb can pick it up. 2428 If this option is not selected, all system framebuffers are always 2429 marked as fallback platform framebuffers as usual. 2430 2431 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2432 not be able to pick up generic system framebuffers if this option 2433 is selected. You are highly encouraged to enable simplefb as 2434 replacement if you select this option. simplefb can correctly deal 2435 with generic system framebuffers. But you should still keep vesafb 2436 and others enabled as fallback if a system framebuffer is 2437 incompatible with simplefb. 2438 2439 If unsure, say Y. 2440 2441endmenu 2442 2443 2444menu "Executable file formats / Emulations" 2445 2446source "fs/Kconfig.binfmt" 2447 2448config IA32_EMULATION 2449 bool "IA32 Emulation" 2450 depends on X86_64 2451 select BINFMT_ELF 2452 select COMPAT_BINFMT_ELF 2453 select HAVE_UID16 2454 ---help--- 2455 Include code to run legacy 32-bit programs under a 2456 64-bit kernel. You should likely turn this on, unless you're 2457 100% sure that you don't have any 32-bit programs left. 2458 2459config IA32_AOUT 2460 tristate "IA32 a.out support" 2461 depends on IA32_EMULATION 2462 ---help--- 2463 Support old a.out binaries in the 32bit emulation. 2464 2465config X86_X32 2466 bool "x32 ABI for 64-bit mode" 2467 depends on X86_64 && IA32_EMULATION 2468 ---help--- 2469 Include code to run binaries for the x32 native 32-bit ABI 2470 for 64-bit processors. An x32 process gets access to the 2471 full 64-bit register file and wide data path while leaving 2472 pointers at 32 bits for smaller memory footprint. 2473 2474 You will need a recent binutils (2.22 or later) with 2475 elf32_x86_64 support enabled to compile a kernel with this 2476 option set. 2477 2478config COMPAT 2479 def_bool y 2480 depends on IA32_EMULATION || X86_X32 2481 select ARCH_WANT_OLD_COMPAT_IPC 2482 2483if COMPAT 2484config COMPAT_FOR_U64_ALIGNMENT 2485 def_bool y 2486 2487config SYSVIPC_COMPAT 2488 def_bool y 2489 depends on SYSVIPC 2490endif 2491 2492endmenu 2493 2494 2495config HAVE_ATOMIC_IOMAP 2496 def_bool y 2497 depends on X86_32 2498 2499config X86_DEV_DMA_OPS 2500 bool 2501 depends on X86_64 || STA2X11 2502 2503config X86_DMA_REMAP 2504 bool 2505 depends on STA2X11 2506 2507config PMC_ATOM 2508 def_bool y 2509 depends on PCI 2510 2511source "net/Kconfig" 2512 2513source "drivers/Kconfig" 2514 2515source "drivers/firmware/Kconfig" 2516 2517source "fs/Kconfig" 2518 2519source "arch/x86/Kconfig.debug" 2520 2521source "security/Kconfig" 2522 2523source "crypto/Kconfig" 2524 2525source "arch/x86/kvm/Kconfig" 2526 2527source "lib/Kconfig" 2528