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 13config X86_64 14 def_bool y 15 depends on 64BIT 16 17### Arch settings 18config X86 19 def_bool y 20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 22 select ANON_INODES 23 select ARCH_CLOCKSOURCE_DATA 24 select ARCH_DISCARD_MEMBLOCK 25 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 26 select ARCH_HAS_DEVMEM_IS_ALLOWED 27 select ARCH_HAS_ELF_RANDOMIZE 28 select ARCH_HAS_FAST_MULTIPLIER 29 select ARCH_HAS_GCOV_PROFILE_ALL 30 select ARCH_HAS_GIGANTIC_PAGE if X86_64 31 select ARCH_HAS_KCOV if X86_64 32 select ARCH_HAS_PMEM_API if X86_64 33 select ARCH_HAS_MMIO_FLUSH 34 select ARCH_HAS_SG_CHAIN 35 select ARCH_HAS_UBSAN_SANITIZE_ALL 36 select ARCH_HAVE_NMI_SAFE_CMPXCHG 37 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 38 select ARCH_MIGHT_HAVE_PC_PARPORT 39 select ARCH_MIGHT_HAVE_PC_SERIO 40 select ARCH_SUPPORTS_ATOMIC_RMW 41 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 42 select ARCH_SUPPORTS_INT128 if X86_64 43 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 44 select ARCH_USE_BUILTIN_BSWAP 45 select ARCH_USE_CMPXCHG_LOCKREF if X86_64 46 select ARCH_USE_QUEUED_RWLOCKS 47 select ARCH_USE_QUEUED_SPINLOCKS 48 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 49 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 50 select ARCH_WANT_FRAME_POINTERS 51 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 52 select BUILDTIME_EXTABLE_SORT 53 select CLKEVT_I8253 54 select CLKSRC_I8253 if X86_32 55 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 56 select CLOCKSOURCE_WATCHDOG 57 select CLONE_BACKWARDS if X86_32 58 select COMPAT_OLD_SIGACTION if IA32_EMULATION 59 select DCACHE_WORD_ACCESS 60 select EDAC_ATOMIC_SCRUB 61 select EDAC_SUPPORT 62 select GENERIC_CLOCKEVENTS 63 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 64 select GENERIC_CLOCKEVENTS_MIN_ADJUST 65 select GENERIC_CMOS_UPDATE 66 select GENERIC_CPU_AUTOPROBE 67 select GENERIC_EARLY_IOREMAP 68 select GENERIC_FIND_FIRST_BIT 69 select GENERIC_IOMAP 70 select GENERIC_IRQ_PROBE 71 select GENERIC_IRQ_SHOW 72 select GENERIC_PENDING_IRQ if SMP 73 select GENERIC_SMP_IDLE_THREAD 74 select GENERIC_STRNCPY_FROM_USER 75 select GENERIC_STRNLEN_USER 76 select GENERIC_TIME_VSYSCALL 77 select HAVE_ACPI_APEI if ACPI 78 select HAVE_ACPI_APEI_NMI if ACPI 79 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 80 select HAVE_AOUT if X86_32 81 select HAVE_ARCH_AUDITSYSCALL 82 select HAVE_ARCH_HARDENED_USERCOPY 83 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 84 select HAVE_ARCH_JUMP_LABEL 85 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 86 select HAVE_ARCH_KGDB 87 select HAVE_ARCH_KMEMCHECK 88 select HAVE_ARCH_MMAP_RND_BITS if MMU 89 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 90 select HAVE_ARCH_SECCOMP_FILTER 91 select HAVE_ARCH_SOFT_DIRTY if X86_64 92 select HAVE_ARCH_TRACEHOOK 93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 94 select HAVE_ARCH_WITHIN_STACK_FRAMES 95 select HAVE_EBPF_JIT if X86_64 96 select HAVE_ARCH_VMAP_STACK if X86_64 97 select HAVE_CC_STACKPROTECTOR 98 select HAVE_CMPXCHG_DOUBLE 99 select HAVE_CMPXCHG_LOCAL 100 select HAVE_CONTEXT_TRACKING if X86_64 101 select HAVE_COPY_THREAD_TLS 102 select HAVE_C_RECORDMCOUNT 103 select HAVE_DEBUG_KMEMLEAK 104 select HAVE_DEBUG_STACKOVERFLOW 105 select HAVE_DMA_API_DEBUG 106 select HAVE_DMA_CONTIGUOUS 107 select HAVE_DYNAMIC_FTRACE 108 select HAVE_DYNAMIC_FTRACE_WITH_REGS 109 select HAVE_EFFICIENT_UNALIGNED_ACCESS 110 select HAVE_EXIT_THREAD 111 select HAVE_FENTRY if X86_64 112 select HAVE_FTRACE_MCOUNT_RECORD 113 select HAVE_FUNCTION_GRAPH_TRACER 114 select HAVE_FUNCTION_TRACER 115 select HAVE_GCC_PLUGINS 116 select HAVE_GENERIC_DMA_COHERENT if X86_32 117 select HAVE_HW_BREAKPOINT 118 select HAVE_IDE 119 select HAVE_IOREMAP_PROT 120 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 121 select HAVE_IRQ_TIME_ACCOUNTING 122 select HAVE_KERNEL_BZIP2 123 select HAVE_KERNEL_GZIP 124 select HAVE_KERNEL_LZ4 125 select HAVE_KERNEL_LZMA 126 select HAVE_KERNEL_LZO 127 select HAVE_KERNEL_XZ 128 select HAVE_KPROBES 129 select HAVE_KPROBES_ON_FTRACE 130 select HAVE_KRETPROBES 131 select HAVE_KVM 132 select HAVE_LIVEPATCH if X86_64 133 select HAVE_MEMBLOCK 134 select HAVE_MEMBLOCK_NODE_MAP 135 select HAVE_MIXED_BREAKPOINTS_REGS 136 select HAVE_NMI 137 select HAVE_OPROFILE 138 select HAVE_OPTPROBES 139 select HAVE_PCSPKR_PLATFORM 140 select HAVE_PERF_EVENTS 141 select HAVE_PERF_EVENTS_NMI 142 select HAVE_PERF_REGS 143 select HAVE_PERF_USER_STACK_DUMP 144 select HAVE_REGS_AND_STACK_ACCESS_API 145 select HAVE_SYSCALL_TRACEPOINTS 146 select HAVE_UID16 if X86_32 || IA32_EMULATION 147 select HAVE_UNSTABLE_SCHED_CLOCK 148 select HAVE_USER_RETURN_NOTIFIER 149 select IRQ_FORCED_THREADING 150 select MODULES_USE_ELF_RELA if X86_64 151 select MODULES_USE_ELF_REL if X86_32 152 select OLD_SIGACTION if X86_32 153 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 154 select PERF_EVENTS 155 select RTC_LIB 156 select RTC_MC146818_LIB 157 select SPARSE_IRQ 158 select SRCU 159 select SYSCTL_EXCEPTION_TRACE 160 select THREAD_INFO_IN_TASK 161 select USER_STACKTRACE_SUPPORT 162 select VIRT_TO_BUS 163 select X86_DEV_DMA_OPS if X86_64 164 select X86_FEATURE_NAMES if PROC_FS 165 select HAVE_STACK_VALIDATION if X86_64 166 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS 167 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS 168 169config INSTRUCTION_DECODER 170 def_bool y 171 depends on KPROBES || PERF_EVENTS || UPROBES 172 173config OUTPUT_FORMAT 174 string 175 default "elf32-i386" if X86_32 176 default "elf64-x86-64" if X86_64 177 178config ARCH_DEFCONFIG 179 string 180 default "arch/x86/configs/i386_defconfig" if X86_32 181 default "arch/x86/configs/x86_64_defconfig" if X86_64 182 183config LOCKDEP_SUPPORT 184 def_bool y 185 186config STACKTRACE_SUPPORT 187 def_bool y 188 189config MMU 190 def_bool y 191 192config ARCH_MMAP_RND_BITS_MIN 193 default 28 if 64BIT 194 default 8 195 196config ARCH_MMAP_RND_BITS_MAX 197 default 32 if 64BIT 198 default 16 199 200config ARCH_MMAP_RND_COMPAT_BITS_MIN 201 default 8 202 203config ARCH_MMAP_RND_COMPAT_BITS_MAX 204 default 16 205 206config SBUS 207 bool 208 209config NEED_DMA_MAP_STATE 210 def_bool y 211 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 212 213config NEED_SG_DMA_LENGTH 214 def_bool y 215 216config GENERIC_ISA_DMA 217 def_bool y 218 depends on ISA_DMA_API 219 220config GENERIC_BUG 221 def_bool y 222 depends on BUG 223 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 224 225config GENERIC_BUG_RELATIVE_POINTERS 226 bool 227 228config GENERIC_HWEIGHT 229 def_bool y 230 231config ARCH_MAY_HAVE_PC_FDC 232 def_bool y 233 depends on ISA_DMA_API 234 235config RWSEM_XCHGADD_ALGORITHM 236 def_bool y 237 238config GENERIC_CALIBRATE_DELAY 239 def_bool y 240 241config ARCH_HAS_CPU_RELAX 242 def_bool y 243 244config ARCH_HAS_CACHE_LINE_SIZE 245 def_bool y 246 247config HAVE_SETUP_PER_CPU_AREA 248 def_bool y 249 250config NEED_PER_CPU_EMBED_FIRST_CHUNK 251 def_bool y 252 253config NEED_PER_CPU_PAGE_FIRST_CHUNK 254 def_bool y 255 256config ARCH_HIBERNATION_POSSIBLE 257 def_bool y 258 259config ARCH_SUSPEND_POSSIBLE 260 def_bool y 261 262config ARCH_WANT_HUGE_PMD_SHARE 263 def_bool y 264 265config ARCH_WANT_GENERAL_HUGETLB 266 def_bool y 267 268config ZONE_DMA32 269 def_bool y if X86_64 270 271config AUDIT_ARCH 272 def_bool y if X86_64 273 274config ARCH_SUPPORTS_OPTIMIZED_INLINING 275 def_bool y 276 277config ARCH_SUPPORTS_DEBUG_PAGEALLOC 278 def_bool y 279 280config KASAN_SHADOW_OFFSET 281 hex 282 depends on KASAN 283 default 0xdffffc0000000000 284 285config HAVE_INTEL_TXT 286 def_bool y 287 depends on INTEL_IOMMU && ACPI 288 289config X86_32_SMP 290 def_bool y 291 depends on X86_32 && SMP 292 293config X86_64_SMP 294 def_bool y 295 depends on X86_64 && SMP 296 297config X86_32_LAZY_GS 298 def_bool y 299 depends on X86_32 && !CC_STACKPROTECTOR 300 301config ARCH_SUPPORTS_UPROBES 302 def_bool y 303 304config FIX_EARLYCON_MEM 305 def_bool y 306 307config DEBUG_RODATA 308 def_bool y 309 310config PGTABLE_LEVELS 311 int 312 default 4 if X86_64 313 default 3 if X86_PAE 314 default 2 315 316source "init/Kconfig" 317source "kernel/Kconfig.freezer" 318 319menu "Processor type and features" 320 321config ZONE_DMA 322 bool "DMA memory allocation support" if EXPERT 323 default y 324 help 325 DMA memory allocation support allows devices with less than 32-bit 326 addressing to allocate within the first 16MB of address space. 327 Disable if no such devices will be used. 328 329 If unsure, say Y. 330 331config SMP 332 bool "Symmetric multi-processing support" 333 ---help--- 334 This enables support for systems with more than one CPU. If you have 335 a system with only one CPU, say N. If you have a system with more 336 than one CPU, say Y. 337 338 If you say N here, the kernel will run on uni- and multiprocessor 339 machines, but will use only one CPU of a multiprocessor machine. If 340 you say Y here, the kernel will run on many, but not all, 341 uniprocessor machines. On a uniprocessor machine, the kernel 342 will run faster if you say N here. 343 344 Note that if you say Y here and choose architecture "586" or 345 "Pentium" under "Processor family", the kernel will not work on 486 346 architectures. Similarly, multiprocessor kernels for the "PPro" 347 architecture may not work on all Pentium based boards. 348 349 People using multiprocessor machines who say Y here should also say 350 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 351 Management" code will be disabled if you say Y here. 352 353 See also <file:Documentation/x86/i386/IO-APIC.txt>, 354 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 355 <http://www.tldp.org/docs.html#howto>. 356 357 If you don't know what to do here, say N. 358 359config X86_FEATURE_NAMES 360 bool "Processor feature human-readable names" if EMBEDDED 361 default y 362 ---help--- 363 This option compiles in a table of x86 feature bits and corresponding 364 names. This is required to support /proc/cpuinfo and a few kernel 365 messages. You can disable this to save space, at the expense of 366 making those few kernel messages show numeric feature bits instead. 367 368 If in doubt, say Y. 369 370config X86_FAST_FEATURE_TESTS 371 bool "Fast CPU feature tests" if EMBEDDED 372 default y 373 ---help--- 374 Some fast-paths in the kernel depend on the capabilities of the CPU. 375 Say Y here for the kernel to patch in the appropriate code at runtime 376 based on the capabilities of the CPU. The infrastructure for patching 377 code at runtime takes up some additional space; space-constrained 378 embedded systems may wish to say N here to produce smaller, slightly 379 slower code. 380 381config X86_X2APIC 382 bool "Support x2apic" 383 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 384 ---help--- 385 This enables x2apic support on CPUs that have this feature. 386 387 This allows 32-bit apic IDs (so it can support very large systems), 388 and accesses the local apic via MSRs not via mmio. 389 390 If you don't know what to do here, say N. 391 392config X86_MPPARSE 393 bool "Enable MPS table" if ACPI || SFI 394 default y 395 depends on X86_LOCAL_APIC 396 ---help--- 397 For old smp systems that do not have proper acpi support. Newer systems 398 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 399 400config X86_BIGSMP 401 bool "Support for big SMP systems with more than 8 CPUs" 402 depends on X86_32 && SMP 403 ---help--- 404 This option is needed for the systems that have more than 8 CPUs 405 406config GOLDFISH 407 def_bool y 408 depends on X86_GOLDFISH 409 410if X86_32 411config X86_EXTENDED_PLATFORM 412 bool "Support for extended (non-PC) x86 platforms" 413 default y 414 ---help--- 415 If you disable this option then the kernel will only support 416 standard PC platforms. (which covers the vast majority of 417 systems out there.) 418 419 If you enable this option then you'll be able to select support 420 for the following (non-PC) 32 bit x86 platforms: 421 Goldfish (Android emulator) 422 AMD Elan 423 RDC R-321x SoC 424 SGI 320/540 (Visual Workstation) 425 STA2X11-based (e.g. Northville) 426 Moorestown MID devices 427 428 If you have one of these systems, or if you want to build a 429 generic distribution kernel, say Y here - otherwise say N. 430endif 431 432if X86_64 433config X86_EXTENDED_PLATFORM 434 bool "Support for extended (non-PC) x86 platforms" 435 default y 436 ---help--- 437 If you disable this option then the kernel will only support 438 standard PC platforms. (which covers the vast majority of 439 systems out there.) 440 441 If you enable this option then you'll be able to select support 442 for the following (non-PC) 64 bit x86 platforms: 443 Numascale NumaChip 444 ScaleMP vSMP 445 SGI Ultraviolet 446 447 If you have one of these systems, or if you want to build a 448 generic distribution kernel, say Y here - otherwise say N. 449endif 450# This is an alphabetically sorted list of 64 bit extended platforms 451# Please maintain the alphabetic order if and when there are additions 452config X86_NUMACHIP 453 bool "Numascale NumaChip" 454 depends on X86_64 455 depends on X86_EXTENDED_PLATFORM 456 depends on NUMA 457 depends on SMP 458 depends on X86_X2APIC 459 depends on PCI_MMCONFIG 460 ---help--- 461 Adds support for Numascale NumaChip large-SMP systems. Needed to 462 enable more than ~168 cores. 463 If you don't have one of these, you should say N here. 464 465config X86_VSMP 466 bool "ScaleMP vSMP" 467 select HYPERVISOR_GUEST 468 select PARAVIRT 469 depends on X86_64 && PCI 470 depends on X86_EXTENDED_PLATFORM 471 depends on SMP 472 ---help--- 473 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 474 supposed to run on these EM64T-based machines. Only choose this option 475 if you have one of these machines. 476 477config X86_UV 478 bool "SGI Ultraviolet" 479 depends on X86_64 480 depends on X86_EXTENDED_PLATFORM 481 depends on NUMA 482 depends on EFI 483 depends on X86_X2APIC 484 depends on PCI 485 ---help--- 486 This option is needed in order to support SGI Ultraviolet systems. 487 If you don't have one of these, you should say N here. 488 489# Following is an alphabetically sorted list of 32 bit extended platforms 490# Please maintain the alphabetic order if and when there are additions 491 492config X86_GOLDFISH 493 bool "Goldfish (Virtual Platform)" 494 depends on X86_EXTENDED_PLATFORM 495 ---help--- 496 Enable support for the Goldfish virtual platform used primarily 497 for Android development. Unless you are building for the Android 498 Goldfish emulator say N here. 499 500config X86_INTEL_CE 501 bool "CE4100 TV platform" 502 depends on PCI 503 depends on PCI_GODIRECT 504 depends on X86_IO_APIC 505 depends on X86_32 506 depends on X86_EXTENDED_PLATFORM 507 select X86_REBOOTFIXUPS 508 select OF 509 select OF_EARLY_FLATTREE 510 ---help--- 511 Select for the Intel CE media processor (CE4100) SOC. 512 This option compiles in support for the CE4100 SOC for settop 513 boxes and media devices. 514 515config X86_INTEL_MID 516 bool "Intel MID platform support" 517 depends on X86_EXTENDED_PLATFORM 518 depends on X86_PLATFORM_DEVICES 519 depends on PCI 520 depends on X86_64 || (PCI_GOANY && X86_32) 521 depends on X86_IO_APIC 522 select SFI 523 select I2C 524 select DW_APB_TIMER 525 select APB_TIMER 526 select INTEL_SCU_IPC 527 select MFD_INTEL_MSIC 528 ---help--- 529 Select to build a kernel capable of supporting Intel MID (Mobile 530 Internet Device) platform systems which do not have the PCI legacy 531 interfaces. If you are building for a PC class system say N here. 532 533 Intel MID platforms are based on an Intel processor and chipset which 534 consume less power than most of the x86 derivatives. 535 536config X86_INTEL_QUARK 537 bool "Intel Quark platform support" 538 depends on X86_32 539 depends on X86_EXTENDED_PLATFORM 540 depends on X86_PLATFORM_DEVICES 541 depends on X86_TSC 542 depends on PCI 543 depends on PCI_GOANY 544 depends on X86_IO_APIC 545 select IOSF_MBI 546 select INTEL_IMR 547 select COMMON_CLK 548 ---help--- 549 Select to include support for Quark X1000 SoC. 550 Say Y here if you have a Quark based system such as the Arduino 551 compatible Intel Galileo. 552 553config MLX_PLATFORM 554 tristate "Mellanox Technologies platform support" 555 depends on X86_64 556 depends on X86_EXTENDED_PLATFORM 557 ---help--- 558 This option enables system support for the Mellanox Technologies 559 platform. 560 561 Say Y here if you are building a kernel for Mellanox system. 562 563 Otherwise, say N. 564 565config X86_INTEL_LPSS 566 bool "Intel Low Power Subsystem Support" 567 depends on X86 && ACPI 568 select COMMON_CLK 569 select PINCTRL 570 select IOSF_MBI 571 ---help--- 572 Select to build support for Intel Low Power Subsystem such as 573 found on Intel Lynxpoint PCH. Selecting this option enables 574 things like clock tree (common clock framework) and pincontrol 575 which are needed by the LPSS peripheral drivers. 576 577config X86_AMD_PLATFORM_DEVICE 578 bool "AMD ACPI2Platform devices support" 579 depends on ACPI 580 select COMMON_CLK 581 select PINCTRL 582 ---help--- 583 Select to interpret AMD specific ACPI device to platform device 584 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 585 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 586 implemented under PINCTRL subsystem. 587 588config IOSF_MBI 589 tristate "Intel SoC IOSF Sideband support for SoC platforms" 590 depends on PCI 591 ---help--- 592 This option enables sideband register access support for Intel SoC 593 platforms. On these platforms the IOSF sideband is used in lieu of 594 MSR's for some register accesses, mostly but not limited to thermal 595 and power. Drivers may query the availability of this device to 596 determine if they need the sideband in order to work on these 597 platforms. The sideband is available on the following SoC products. 598 This list is not meant to be exclusive. 599 - BayTrail 600 - Braswell 601 - Quark 602 603 You should say Y if you are running a kernel on one of these SoC's. 604 605config IOSF_MBI_DEBUG 606 bool "Enable IOSF sideband access through debugfs" 607 depends on IOSF_MBI && DEBUG_FS 608 ---help--- 609 Select this option to expose the IOSF sideband access registers (MCR, 610 MDR, MCRX) through debugfs to write and read register information from 611 different units on the SoC. This is most useful for obtaining device 612 state information for debug and analysis. As this is a general access 613 mechanism, users of this option would have specific knowledge of the 614 device they want to access. 615 616 If you don't require the option or are in doubt, say N. 617 618config X86_RDC321X 619 bool "RDC R-321x SoC" 620 depends on X86_32 621 depends on X86_EXTENDED_PLATFORM 622 select M486 623 select X86_REBOOTFIXUPS 624 ---help--- 625 This option is needed for RDC R-321x system-on-chip, also known 626 as R-8610-(G). 627 If you don't have one of these chips, you should say N here. 628 629config X86_32_NON_STANDARD 630 bool "Support non-standard 32-bit SMP architectures" 631 depends on X86_32 && SMP 632 depends on X86_EXTENDED_PLATFORM 633 ---help--- 634 This option compiles in the bigsmp and STA2X11 default 635 subarchitectures. It is intended for a generic binary 636 kernel. If you select them all, kernel will probe it one by 637 one and will fallback to default. 638 639# Alphabetically sorted list of Non standard 32 bit platforms 640 641config X86_SUPPORTS_MEMORY_FAILURE 642 def_bool y 643 # MCE code calls memory_failure(): 644 depends on X86_MCE 645 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 646 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 647 depends on X86_64 || !SPARSEMEM 648 select ARCH_SUPPORTS_MEMORY_FAILURE 649 650config STA2X11 651 bool "STA2X11 Companion Chip Support" 652 depends on X86_32_NON_STANDARD && PCI 653 select X86_DEV_DMA_OPS 654 select X86_DMA_REMAP 655 select SWIOTLB 656 select MFD_STA2X11 657 select GPIOLIB 658 default n 659 ---help--- 660 This adds support for boards based on the STA2X11 IO-Hub, 661 a.k.a. "ConneXt". The chip is used in place of the standard 662 PC chipset, so all "standard" peripherals are missing. If this 663 option is selected the kernel will still be able to boot on 664 standard PC machines. 665 666config X86_32_IRIS 667 tristate "Eurobraille/Iris poweroff module" 668 depends on X86_32 669 ---help--- 670 The Iris machines from EuroBraille do not have APM or ACPI support 671 to shut themselves down properly. A special I/O sequence is 672 needed to do so, which is what this module does at 673 kernel shutdown. 674 675 This is only for Iris machines from EuroBraille. 676 677 If unused, say N. 678 679config SCHED_OMIT_FRAME_POINTER 680 def_bool y 681 prompt "Single-depth WCHAN output" 682 depends on X86 683 ---help--- 684 Calculate simpler /proc/<PID>/wchan values. If this option 685 is disabled then wchan values will recurse back to the 686 caller function. This provides more accurate wchan values, 687 at the expense of slightly more scheduling overhead. 688 689 If in doubt, say "Y". 690 691menuconfig HYPERVISOR_GUEST 692 bool "Linux guest support" 693 ---help--- 694 Say Y here to enable options for running Linux under various hyper- 695 visors. This option enables basic hypervisor detection and platform 696 setup. 697 698 If you say N, all options in this submenu will be skipped and 699 disabled, and Linux guest support won't be built in. 700 701if HYPERVISOR_GUEST 702 703config PARAVIRT 704 bool "Enable paravirtualization code" 705 ---help--- 706 This changes the kernel so it can modify itself when it is run 707 under a hypervisor, potentially improving performance significantly 708 over full virtualization. However, when run without a hypervisor 709 the kernel is theoretically slower and slightly larger. 710 711config PARAVIRT_DEBUG 712 bool "paravirt-ops debugging" 713 depends on PARAVIRT && DEBUG_KERNEL 714 ---help--- 715 Enable to debug paravirt_ops internals. Specifically, BUG if 716 a paravirt_op is missing when it is called. 717 718config PARAVIRT_SPINLOCKS 719 bool "Paravirtualization layer for spinlocks" 720 depends on PARAVIRT && SMP 721 ---help--- 722 Paravirtualized spinlocks allow a pvops backend to replace the 723 spinlock implementation with something virtualization-friendly 724 (for example, block the virtual CPU rather than spinning). 725 726 It has a minimal impact on native kernels and gives a nice performance 727 benefit on paravirtualized KVM / Xen kernels. 728 729 If you are unsure how to answer this question, answer Y. 730 731config QUEUED_LOCK_STAT 732 bool "Paravirt queued spinlock statistics" 733 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 734 ---help--- 735 Enable the collection of statistical data on the slowpath 736 behavior of paravirtualized queued spinlocks and report 737 them on debugfs. 738 739source "arch/x86/xen/Kconfig" 740 741config KVM_GUEST 742 bool "KVM Guest support (including kvmclock)" 743 depends on PARAVIRT 744 select PARAVIRT_CLOCK 745 default y 746 ---help--- 747 This option enables various optimizations for running under the KVM 748 hypervisor. It includes a paravirtualized clock, so that instead 749 of relying on a PIT (or probably other) emulation by the 750 underlying device model, the host provides the guest with 751 timing infrastructure such as time of day, and system time 752 753config KVM_DEBUG_FS 754 bool "Enable debug information for KVM Guests in debugfs" 755 depends on KVM_GUEST && DEBUG_FS 756 default n 757 ---help--- 758 This option enables collection of various statistics for KVM guest. 759 Statistics are displayed in debugfs filesystem. Enabling this option 760 may incur significant overhead. 761 762source "arch/x86/lguest/Kconfig" 763 764config PARAVIRT_TIME_ACCOUNTING 765 bool "Paravirtual steal time accounting" 766 depends on PARAVIRT 767 default n 768 ---help--- 769 Select this option to enable fine granularity task steal time 770 accounting. Time spent executing other tasks in parallel with 771 the current vCPU is discounted from the vCPU power. To account for 772 that, there can be a small performance impact. 773 774 If in doubt, say N here. 775 776config PARAVIRT_CLOCK 777 bool 778 779endif #HYPERVISOR_GUEST 780 781config NO_BOOTMEM 782 def_bool y 783 784source "arch/x86/Kconfig.cpu" 785 786config HPET_TIMER 787 def_bool X86_64 788 prompt "HPET Timer Support" if X86_32 789 ---help--- 790 Use the IA-PC HPET (High Precision Event Timer) to manage 791 time in preference to the PIT and RTC, if a HPET is 792 present. 793 HPET is the next generation timer replacing legacy 8254s. 794 The HPET provides a stable time base on SMP 795 systems, unlike the TSC, but it is more expensive to access, 796 as it is off-chip. The interface used is documented 797 in the HPET spec, revision 1. 798 799 You can safely choose Y here. However, HPET will only be 800 activated if the platform and the BIOS support this feature. 801 Otherwise the 8254 will be used for timing services. 802 803 Choose N to continue using the legacy 8254 timer. 804 805config HPET_EMULATE_RTC 806 def_bool y 807 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 808 809config APB_TIMER 810 def_bool y if X86_INTEL_MID 811 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 812 select DW_APB_TIMER 813 depends on X86_INTEL_MID && SFI 814 help 815 APB timer is the replacement for 8254, HPET on X86 MID platforms. 816 The APBT provides a stable time base on SMP 817 systems, unlike the TSC, but it is more expensive to access, 818 as it is off-chip. APB timers are always running regardless of CPU 819 C states, they are used as per CPU clockevent device when possible. 820 821# Mark as expert because too many people got it wrong. 822# The code disables itself when not needed. 823config DMI 824 default y 825 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 826 bool "Enable DMI scanning" if EXPERT 827 ---help--- 828 Enabled scanning of DMI to identify machine quirks. Say Y 829 here unless you have verified that your setup is not 830 affected by entries in the DMI blacklist. Required by PNP 831 BIOS code. 832 833config GART_IOMMU 834 bool "Old AMD GART IOMMU support" 835 select SWIOTLB 836 depends on X86_64 && PCI && AMD_NB 837 ---help--- 838 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 839 GART based hardware IOMMUs. 840 841 The GART supports full DMA access for devices with 32-bit access 842 limitations, on systems with more than 3 GB. This is usually needed 843 for USB, sound, many IDE/SATA chipsets and some other devices. 844 845 Newer systems typically have a modern AMD IOMMU, supported via 846 the CONFIG_AMD_IOMMU=y config option. 847 848 In normal configurations this driver is only active when needed: 849 there's more than 3 GB of memory and the system contains a 850 32-bit limited device. 851 852 If unsure, say Y. 853 854config CALGARY_IOMMU 855 bool "IBM Calgary IOMMU support" 856 select SWIOTLB 857 depends on X86_64 && PCI 858 ---help--- 859 Support for hardware IOMMUs in IBM's xSeries x366 and x460 860 systems. Needed to run systems with more than 3GB of memory 861 properly with 32-bit PCI devices that do not support DAC 862 (Double Address Cycle). Calgary also supports bus level 863 isolation, where all DMAs pass through the IOMMU. This 864 prevents them from going anywhere except their intended 865 destination. This catches hard-to-find kernel bugs and 866 mis-behaving drivers and devices that do not use the DMA-API 867 properly to set up their DMA buffers. The IOMMU can be 868 turned off at boot time with the iommu=off parameter. 869 Normally the kernel will make the right choice by itself. 870 If unsure, say Y. 871 872config CALGARY_IOMMU_ENABLED_BY_DEFAULT 873 def_bool y 874 prompt "Should Calgary be enabled by default?" 875 depends on CALGARY_IOMMU 876 ---help--- 877 Should Calgary be enabled by default? if you choose 'y', Calgary 878 will be used (if it exists). If you choose 'n', Calgary will not be 879 used even if it exists. If you choose 'n' and would like to use 880 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 881 If unsure, say Y. 882 883# need this always selected by IOMMU for the VIA workaround 884config SWIOTLB 885 def_bool y if X86_64 886 ---help--- 887 Support for software bounce buffers used on x86-64 systems 888 which don't have a hardware IOMMU. Using this PCI devices 889 which can only access 32-bits of memory can be used on systems 890 with more than 3 GB of memory. 891 If unsure, say Y. 892 893config IOMMU_HELPER 894 def_bool y 895 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 896 897config MAXSMP 898 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 899 depends on X86_64 && SMP && DEBUG_KERNEL 900 select CPUMASK_OFFSTACK 901 ---help--- 902 Enable maximum number of CPUS and NUMA Nodes for this architecture. 903 If unsure, say N. 904 905config NR_CPUS 906 int "Maximum number of CPUs" if SMP && !MAXSMP 907 range 2 8 if SMP && X86_32 && !X86_BIGSMP 908 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 909 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 910 default "1" if !SMP 911 default "8192" if MAXSMP 912 default "32" if SMP && X86_BIGSMP 913 default "8" if SMP && X86_32 914 default "64" if SMP 915 ---help--- 916 This allows you to specify the maximum number of CPUs which this 917 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 918 supported value is 8192, otherwise the maximum value is 512. The 919 minimum value which makes sense is 2. 920 921 This is purely to save memory - each supported CPU adds 922 approximately eight kilobytes to the kernel image. 923 924config SCHED_SMT 925 bool "SMT (Hyperthreading) scheduler support" 926 depends on SMP 927 ---help--- 928 SMT scheduler support improves the CPU scheduler's decision making 929 when dealing with Intel Pentium 4 chips with HyperThreading at a 930 cost of slightly increased overhead in some places. If unsure say 931 N here. 932 933config SCHED_MC 934 def_bool y 935 prompt "Multi-core scheduler support" 936 depends on SMP 937 ---help--- 938 Multi-core scheduler support improves the CPU scheduler's decision 939 making when dealing with multi-core CPU chips at a cost of slightly 940 increased overhead in some places. If unsure say N here. 941 942source "kernel/Kconfig.preempt" 943 944config UP_LATE_INIT 945 def_bool y 946 depends on !SMP && X86_LOCAL_APIC 947 948config X86_UP_APIC 949 bool "Local APIC support on uniprocessors" if !PCI_MSI 950 default PCI_MSI 951 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 952 ---help--- 953 A local APIC (Advanced Programmable Interrupt Controller) is an 954 integrated interrupt controller in the CPU. If you have a single-CPU 955 system which has a processor with a local APIC, you can say Y here to 956 enable and use it. If you say Y here even though your machine doesn't 957 have a local APIC, then the kernel will still run with no slowdown at 958 all. The local APIC supports CPU-generated self-interrupts (timer, 959 performance counters), and the NMI watchdog which detects hard 960 lockups. 961 962config X86_UP_IOAPIC 963 bool "IO-APIC support on uniprocessors" 964 depends on X86_UP_APIC 965 ---help--- 966 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 967 SMP-capable replacement for PC-style interrupt controllers. Most 968 SMP systems and many recent uniprocessor systems have one. 969 970 If you have a single-CPU system with an IO-APIC, you can say Y here 971 to use it. If you say Y here even though your machine doesn't have 972 an IO-APIC, then the kernel will still run with no slowdown at all. 973 974config X86_LOCAL_APIC 975 def_bool y 976 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 977 select IRQ_DOMAIN_HIERARCHY 978 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 979 980config X86_IO_APIC 981 def_bool y 982 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 983 984config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 985 bool "Reroute for broken boot IRQs" 986 depends on X86_IO_APIC 987 ---help--- 988 This option enables a workaround that fixes a source of 989 spurious interrupts. This is recommended when threaded 990 interrupt handling is used on systems where the generation of 991 superfluous "boot interrupts" cannot be disabled. 992 993 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 994 entry in the chipset's IO-APIC is masked (as, e.g. the RT 995 kernel does during interrupt handling). On chipsets where this 996 boot IRQ generation cannot be disabled, this workaround keeps 997 the original IRQ line masked so that only the equivalent "boot 998 IRQ" is delivered to the CPUs. The workaround also tells the 999 kernel to set up the IRQ handler on the boot IRQ line. In this 1000 way only one interrupt is delivered to the kernel. Otherwise 1001 the spurious second interrupt may cause the kernel to bring 1002 down (vital) interrupt lines. 1003 1004 Only affects "broken" chipsets. Interrupt sharing may be 1005 increased on these systems. 1006 1007config X86_MCE 1008 bool "Machine Check / overheating reporting" 1009 select GENERIC_ALLOCATOR 1010 default y 1011 ---help--- 1012 Machine Check support allows the processor to notify the 1013 kernel if it detects a problem (e.g. overheating, data corruption). 1014 The action the kernel takes depends on the severity of the problem, 1015 ranging from warning messages to halting the machine. 1016 1017config X86_MCE_INTEL 1018 def_bool y 1019 prompt "Intel MCE features" 1020 depends on X86_MCE && X86_LOCAL_APIC 1021 ---help--- 1022 Additional support for intel specific MCE features such as 1023 the thermal monitor. 1024 1025config X86_MCE_AMD 1026 def_bool y 1027 prompt "AMD MCE features" 1028 depends on X86_MCE && X86_LOCAL_APIC 1029 ---help--- 1030 Additional support for AMD specific MCE features such as 1031 the DRAM Error Threshold. 1032 1033config X86_ANCIENT_MCE 1034 bool "Support for old Pentium 5 / WinChip machine checks" 1035 depends on X86_32 && X86_MCE 1036 ---help--- 1037 Include support for machine check handling on old Pentium 5 or WinChip 1038 systems. These typically need to be enabled explicitly on the command 1039 line. 1040 1041config X86_MCE_THRESHOLD 1042 depends on X86_MCE_AMD || X86_MCE_INTEL 1043 def_bool y 1044 1045config X86_MCE_INJECT 1046 depends on X86_MCE 1047 tristate "Machine check injector support" 1048 ---help--- 1049 Provide support for injecting machine checks for testing purposes. 1050 If you don't know what a machine check is and you don't do kernel 1051 QA it is safe to say n. 1052 1053config X86_THERMAL_VECTOR 1054 def_bool y 1055 depends on X86_MCE_INTEL 1056 1057source "arch/x86/events/Kconfig" 1058 1059config X86_LEGACY_VM86 1060 bool "Legacy VM86 support" 1061 default n 1062 depends on X86_32 1063 ---help--- 1064 This option allows user programs to put the CPU into V8086 1065 mode, which is an 80286-era approximation of 16-bit real mode. 1066 1067 Some very old versions of X and/or vbetool require this option 1068 for user mode setting. Similarly, DOSEMU will use it if 1069 available to accelerate real mode DOS programs. However, any 1070 recent version of DOSEMU, X, or vbetool should be fully 1071 functional even without kernel VM86 support, as they will all 1072 fall back to software emulation. Nevertheless, if you are using 1073 a 16-bit DOS program where 16-bit performance matters, vm86 1074 mode might be faster than emulation and you might want to 1075 enable this option. 1076 1077 Note that any app that works on a 64-bit kernel is unlikely to 1078 need this option, as 64-bit kernels don't, and can't, support 1079 V8086 mode. This option is also unrelated to 16-bit protected 1080 mode and is not needed to run most 16-bit programs under Wine. 1081 1082 Enabling this option increases the complexity of the kernel 1083 and slows down exception handling a tiny bit. 1084 1085 If unsure, say N here. 1086 1087config VM86 1088 bool 1089 default X86_LEGACY_VM86 1090 1091config X86_16BIT 1092 bool "Enable support for 16-bit segments" if EXPERT 1093 default y 1094 depends on MODIFY_LDT_SYSCALL 1095 ---help--- 1096 This option is required by programs like Wine to run 16-bit 1097 protected mode legacy code on x86 processors. Disabling 1098 this option saves about 300 bytes on i386, or around 6K text 1099 plus 16K runtime memory on x86-64, 1100 1101config X86_ESPFIX32 1102 def_bool y 1103 depends on X86_16BIT && X86_32 1104 1105config X86_ESPFIX64 1106 def_bool y 1107 depends on X86_16BIT && X86_64 1108 1109config X86_VSYSCALL_EMULATION 1110 bool "Enable vsyscall emulation" if EXPERT 1111 default y 1112 depends on X86_64 1113 ---help--- 1114 This enables emulation of the legacy vsyscall page. Disabling 1115 it is roughly equivalent to booting with vsyscall=none, except 1116 that it will also disable the helpful warning if a program 1117 tries to use a vsyscall. With this option set to N, offending 1118 programs will just segfault, citing addresses of the form 1119 0xffffffffff600?00. 1120 1121 This option is required by many programs built before 2013, and 1122 care should be used even with newer programs if set to N. 1123 1124 Disabling this option saves about 7K of kernel size and 1125 possibly 4K of additional runtime pagetable memory. 1126 1127config TOSHIBA 1128 tristate "Toshiba Laptop support" 1129 depends on X86_32 1130 ---help--- 1131 This adds a driver to safely access the System Management Mode of 1132 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1133 not work on models with a Phoenix BIOS. The System Management Mode 1134 is used to set the BIOS and power saving options on Toshiba portables. 1135 1136 For information on utilities to make use of this driver see the 1137 Toshiba Linux utilities web site at: 1138 <http://www.buzzard.org.uk/toshiba/>. 1139 1140 Say Y if you intend to run this kernel on a Toshiba portable. 1141 Say N otherwise. 1142 1143config I8K 1144 tristate "Dell i8k legacy laptop support" 1145 select HWMON 1146 select SENSORS_DELL_SMM 1147 ---help--- 1148 This option enables legacy /proc/i8k userspace interface in hwmon 1149 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1150 temperature and allows controlling fan speeds of Dell laptops via 1151 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1152 it reports also power and hotkey status. For fan speed control is 1153 needed userspace package i8kutils. 1154 1155 Say Y if you intend to run this kernel on old Dell laptops or want to 1156 use userspace package i8kutils. 1157 Say N otherwise. 1158 1159config X86_REBOOTFIXUPS 1160 bool "Enable X86 board specific fixups for reboot" 1161 depends on X86_32 1162 ---help--- 1163 This enables chipset and/or board specific fixups to be done 1164 in order to get reboot to work correctly. This is only needed on 1165 some combinations of hardware and BIOS. The symptom, for which 1166 this config is intended, is when reboot ends with a stalled/hung 1167 system. 1168 1169 Currently, the only fixup is for the Geode machines using 1170 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1171 1172 Say Y if you want to enable the fixup. Currently, it's safe to 1173 enable this option even if you don't need it. 1174 Say N otherwise. 1175 1176config MICROCODE 1177 bool "CPU microcode loading support" 1178 default y 1179 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1180 select FW_LOADER 1181 ---help--- 1182 If you say Y here, you will be able to update the microcode on 1183 Intel and AMD processors. The Intel support is for the IA32 family, 1184 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1185 AMD support is for families 0x10 and later. You will obviously need 1186 the actual microcode binary data itself which is not shipped with 1187 the Linux kernel. 1188 1189 The preferred method to load microcode from a detached initrd is described 1190 in Documentation/x86/early-microcode.txt. For that you need to enable 1191 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1192 initrd for microcode blobs. 1193 1194 In addition, you can build-in the microcode into the kernel. For that you 1195 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1196 to the CONFIG_EXTRA_FIRMWARE config option. 1197 1198config MICROCODE_INTEL 1199 bool "Intel microcode loading support" 1200 depends on MICROCODE 1201 default MICROCODE 1202 select FW_LOADER 1203 ---help--- 1204 This options enables microcode patch loading support for Intel 1205 processors. 1206 1207 For the current Intel microcode data package go to 1208 <https://downloadcenter.intel.com> and search for 1209 'Linux Processor Microcode Data File'. 1210 1211config MICROCODE_AMD 1212 bool "AMD microcode loading support" 1213 depends on MICROCODE 1214 select FW_LOADER 1215 ---help--- 1216 If you select this option, microcode patch loading support for AMD 1217 processors will be enabled. 1218 1219config MICROCODE_OLD_INTERFACE 1220 def_bool y 1221 depends on MICROCODE 1222 1223config X86_MSR 1224 tristate "/dev/cpu/*/msr - Model-specific register support" 1225 ---help--- 1226 This device gives privileged processes access to the x86 1227 Model-Specific Registers (MSRs). It is a character device with 1228 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1229 MSR accesses are directed to a specific CPU on multi-processor 1230 systems. 1231 1232config X86_CPUID 1233 tristate "/dev/cpu/*/cpuid - CPU information support" 1234 ---help--- 1235 This device gives processes access to the x86 CPUID instruction to 1236 be executed on a specific processor. It is a character device 1237 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1238 /dev/cpu/31/cpuid. 1239 1240choice 1241 prompt "High Memory Support" 1242 default HIGHMEM4G 1243 depends on X86_32 1244 1245config NOHIGHMEM 1246 bool "off" 1247 ---help--- 1248 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1249 However, the address space of 32-bit x86 processors is only 4 1250 Gigabytes large. That means that, if you have a large amount of 1251 physical memory, not all of it can be "permanently mapped" by the 1252 kernel. The physical memory that's not permanently mapped is called 1253 "high memory". 1254 1255 If you are compiling a kernel which will never run on a machine with 1256 more than 1 Gigabyte total physical RAM, answer "off" here (default 1257 choice and suitable for most users). This will result in a "3GB/1GB" 1258 split: 3GB are mapped so that each process sees a 3GB virtual memory 1259 space and the remaining part of the 4GB virtual memory space is used 1260 by the kernel to permanently map as much physical memory as 1261 possible. 1262 1263 If the machine has between 1 and 4 Gigabytes physical RAM, then 1264 answer "4GB" here. 1265 1266 If more than 4 Gigabytes is used then answer "64GB" here. This 1267 selection turns Intel PAE (Physical Address Extension) mode on. 1268 PAE implements 3-level paging on IA32 processors. PAE is fully 1269 supported by Linux, PAE mode is implemented on all recent Intel 1270 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1271 then the kernel will not boot on CPUs that don't support PAE! 1272 1273 The actual amount of total physical memory will either be 1274 auto detected or can be forced by using a kernel command line option 1275 such as "mem=256M". (Try "man bootparam" or see the documentation of 1276 your boot loader (lilo or loadlin) about how to pass options to the 1277 kernel at boot time.) 1278 1279 If unsure, say "off". 1280 1281config HIGHMEM4G 1282 bool "4GB" 1283 ---help--- 1284 Select this if you have a 32-bit processor and between 1 and 4 1285 gigabytes of physical RAM. 1286 1287config HIGHMEM64G 1288 bool "64GB" 1289 depends on !M486 1290 select X86_PAE 1291 ---help--- 1292 Select this if you have a 32-bit processor and more than 4 1293 gigabytes of physical RAM. 1294 1295endchoice 1296 1297choice 1298 prompt "Memory split" if EXPERT 1299 default VMSPLIT_3G 1300 depends on X86_32 1301 ---help--- 1302 Select the desired split between kernel and user memory. 1303 1304 If the address range available to the kernel is less than the 1305 physical memory installed, the remaining memory will be available 1306 as "high memory". Accessing high memory is a little more costly 1307 than low memory, as it needs to be mapped into the kernel first. 1308 Note that increasing the kernel address space limits the range 1309 available to user programs, making the address space there 1310 tighter. Selecting anything other than the default 3G/1G split 1311 will also likely make your kernel incompatible with binary-only 1312 kernel modules. 1313 1314 If you are not absolutely sure what you are doing, leave this 1315 option alone! 1316 1317 config VMSPLIT_3G 1318 bool "3G/1G user/kernel split" 1319 config VMSPLIT_3G_OPT 1320 depends on !X86_PAE 1321 bool "3G/1G user/kernel split (for full 1G low memory)" 1322 config VMSPLIT_2G 1323 bool "2G/2G user/kernel split" 1324 config VMSPLIT_2G_OPT 1325 depends on !X86_PAE 1326 bool "2G/2G user/kernel split (for full 2G low memory)" 1327 config VMSPLIT_1G 1328 bool "1G/3G user/kernel split" 1329endchoice 1330 1331config PAGE_OFFSET 1332 hex 1333 default 0xB0000000 if VMSPLIT_3G_OPT 1334 default 0x80000000 if VMSPLIT_2G 1335 default 0x78000000 if VMSPLIT_2G_OPT 1336 default 0x40000000 if VMSPLIT_1G 1337 default 0xC0000000 1338 depends on X86_32 1339 1340config HIGHMEM 1341 def_bool y 1342 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1343 1344config X86_PAE 1345 bool "PAE (Physical Address Extension) Support" 1346 depends on X86_32 && !HIGHMEM4G 1347 select SWIOTLB 1348 ---help--- 1349 PAE is required for NX support, and furthermore enables 1350 larger swapspace support for non-overcommit purposes. It 1351 has the cost of more pagetable lookup overhead, and also 1352 consumes more pagetable space per process. 1353 1354config ARCH_PHYS_ADDR_T_64BIT 1355 def_bool y 1356 depends on X86_64 || X86_PAE 1357 1358config ARCH_DMA_ADDR_T_64BIT 1359 def_bool y 1360 depends on X86_64 || HIGHMEM64G 1361 1362config X86_DIRECT_GBPAGES 1363 def_bool y 1364 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 1365 ---help--- 1366 Certain kernel features effectively disable kernel 1367 linear 1 GB mappings (even if the CPU otherwise 1368 supports them), so don't confuse the user by printing 1369 that we have them enabled. 1370 1371# Common NUMA Features 1372config NUMA 1373 bool "Numa Memory Allocation and Scheduler Support" 1374 depends on SMP 1375 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1376 default y if X86_BIGSMP 1377 ---help--- 1378 Enable NUMA (Non Uniform Memory Access) support. 1379 1380 The kernel will try to allocate memory used by a CPU on the 1381 local memory controller of the CPU and add some more 1382 NUMA awareness to the kernel. 1383 1384 For 64-bit this is recommended if the system is Intel Core i7 1385 (or later), AMD Opteron, or EM64T NUMA. 1386 1387 For 32-bit this is only needed if you boot a 32-bit 1388 kernel on a 64-bit NUMA platform. 1389 1390 Otherwise, you should say N. 1391 1392config AMD_NUMA 1393 def_bool y 1394 prompt "Old style AMD Opteron NUMA detection" 1395 depends on X86_64 && NUMA && PCI 1396 ---help--- 1397 Enable AMD NUMA node topology detection. You should say Y here if 1398 you have a multi processor AMD system. This uses an old method to 1399 read the NUMA configuration directly from the builtin Northbridge 1400 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1401 which also takes priority if both are compiled in. 1402 1403config X86_64_ACPI_NUMA 1404 def_bool y 1405 prompt "ACPI NUMA detection" 1406 depends on X86_64 && NUMA && ACPI && PCI 1407 select ACPI_NUMA 1408 ---help--- 1409 Enable ACPI SRAT based node topology detection. 1410 1411# Some NUMA nodes have memory ranges that span 1412# other nodes. Even though a pfn is valid and 1413# between a node's start and end pfns, it may not 1414# reside on that node. See memmap_init_zone() 1415# for details. 1416config NODES_SPAN_OTHER_NODES 1417 def_bool y 1418 depends on X86_64_ACPI_NUMA 1419 1420config NUMA_EMU 1421 bool "NUMA emulation" 1422 depends on NUMA 1423 ---help--- 1424 Enable NUMA emulation. A flat machine will be split 1425 into virtual nodes when booted with "numa=fake=N", where N is the 1426 number of nodes. This is only useful for debugging. 1427 1428config NODES_SHIFT 1429 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1430 range 1 10 1431 default "10" if MAXSMP 1432 default "6" if X86_64 1433 default "3" 1434 depends on NEED_MULTIPLE_NODES 1435 ---help--- 1436 Specify the maximum number of NUMA Nodes available on the target 1437 system. Increases memory reserved to accommodate various tables. 1438 1439config ARCH_HAVE_MEMORY_PRESENT 1440 def_bool y 1441 depends on X86_32 && DISCONTIGMEM 1442 1443config NEED_NODE_MEMMAP_SIZE 1444 def_bool y 1445 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1446 1447config ARCH_FLATMEM_ENABLE 1448 def_bool y 1449 depends on X86_32 && !NUMA 1450 1451config ARCH_DISCONTIGMEM_ENABLE 1452 def_bool y 1453 depends on NUMA && X86_32 1454 1455config ARCH_DISCONTIGMEM_DEFAULT 1456 def_bool y 1457 depends on NUMA && X86_32 1458 1459config ARCH_SPARSEMEM_ENABLE 1460 def_bool y 1461 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1462 select SPARSEMEM_STATIC if X86_32 1463 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1464 1465config ARCH_SPARSEMEM_DEFAULT 1466 def_bool y 1467 depends on X86_64 1468 1469config ARCH_SELECT_MEMORY_MODEL 1470 def_bool y 1471 depends on ARCH_SPARSEMEM_ENABLE 1472 1473config ARCH_MEMORY_PROBE 1474 bool "Enable sysfs memory/probe interface" 1475 depends on X86_64 && MEMORY_HOTPLUG 1476 help 1477 This option enables a sysfs memory/probe interface for testing. 1478 See Documentation/memory-hotplug.txt for more information. 1479 If you are unsure how to answer this question, answer N. 1480 1481config ARCH_PROC_KCORE_TEXT 1482 def_bool y 1483 depends on X86_64 && PROC_KCORE 1484 1485config ILLEGAL_POINTER_VALUE 1486 hex 1487 default 0 if X86_32 1488 default 0xdead000000000000 if X86_64 1489 1490source "mm/Kconfig" 1491 1492config X86_PMEM_LEGACY_DEVICE 1493 bool 1494 1495config X86_PMEM_LEGACY 1496 tristate "Support non-standard NVDIMMs and ADR protected memory" 1497 depends on PHYS_ADDR_T_64BIT 1498 depends on BLK_DEV 1499 select X86_PMEM_LEGACY_DEVICE 1500 select LIBNVDIMM 1501 help 1502 Treat memory marked using the non-standard e820 type of 12 as used 1503 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1504 The kernel will offer these regions to the 'pmem' driver so 1505 they can be used for persistent storage. 1506 1507 Say Y if unsure. 1508 1509config HIGHPTE 1510 bool "Allocate 3rd-level pagetables from highmem" 1511 depends on HIGHMEM 1512 ---help--- 1513 The VM uses one page table entry for each page of physical memory. 1514 For systems with a lot of RAM, this can be wasteful of precious 1515 low memory. Setting this option will put user-space page table 1516 entries in high memory. 1517 1518config X86_CHECK_BIOS_CORRUPTION 1519 bool "Check for low memory corruption" 1520 ---help--- 1521 Periodically check for memory corruption in low memory, which 1522 is suspected to be caused by BIOS. Even when enabled in the 1523 configuration, it is disabled at runtime. Enable it by 1524 setting "memory_corruption_check=1" on the kernel command 1525 line. By default it scans the low 64k of memory every 60 1526 seconds; see the memory_corruption_check_size and 1527 memory_corruption_check_period parameters in 1528 Documentation/kernel-parameters.txt to adjust this. 1529 1530 When enabled with the default parameters, this option has 1531 almost no overhead, as it reserves a relatively small amount 1532 of memory and scans it infrequently. It both detects corruption 1533 and prevents it from affecting the running system. 1534 1535 It is, however, intended as a diagnostic tool; if repeatable 1536 BIOS-originated corruption always affects the same memory, 1537 you can use memmap= to prevent the kernel from using that 1538 memory. 1539 1540config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1541 bool "Set the default setting of memory_corruption_check" 1542 depends on X86_CHECK_BIOS_CORRUPTION 1543 default y 1544 ---help--- 1545 Set whether the default state of memory_corruption_check is 1546 on or off. 1547 1548config X86_RESERVE_LOW 1549 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1550 default 64 1551 range 4 640 1552 ---help--- 1553 Specify the amount of low memory to reserve for the BIOS. 1554 1555 The first page contains BIOS data structures that the kernel 1556 must not use, so that page must always be reserved. 1557 1558 By default we reserve the first 64K of physical RAM, as a 1559 number of BIOSes are known to corrupt that memory range 1560 during events such as suspend/resume or monitor cable 1561 insertion, so it must not be used by the kernel. 1562 1563 You can set this to 4 if you are absolutely sure that you 1564 trust the BIOS to get all its memory reservations and usages 1565 right. If you know your BIOS have problems beyond the 1566 default 64K area, you can set this to 640 to avoid using the 1567 entire low memory range. 1568 1569 If you have doubts about the BIOS (e.g. suspend/resume does 1570 not work or there's kernel crashes after certain hardware 1571 hotplug events) then you might want to enable 1572 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1573 typical corruption patterns. 1574 1575 Leave this to the default value of 64 if you are unsure. 1576 1577config MATH_EMULATION 1578 bool 1579 depends on MODIFY_LDT_SYSCALL 1580 prompt "Math emulation" if X86_32 1581 ---help--- 1582 Linux can emulate a math coprocessor (used for floating point 1583 operations) if you don't have one. 486DX and Pentium processors have 1584 a math coprocessor built in, 486SX and 386 do not, unless you added 1585 a 487DX or 387, respectively. (The messages during boot time can 1586 give you some hints here ["man dmesg"].) Everyone needs either a 1587 coprocessor or this emulation. 1588 1589 If you don't have a math coprocessor, you need to say Y here; if you 1590 say Y here even though you have a coprocessor, the coprocessor will 1591 be used nevertheless. (This behavior can be changed with the kernel 1592 command line option "no387", which comes handy if your coprocessor 1593 is broken. Try "man bootparam" or see the documentation of your boot 1594 loader (lilo or loadlin) about how to pass options to the kernel at 1595 boot time.) This means that it is a good idea to say Y here if you 1596 intend to use this kernel on different machines. 1597 1598 More information about the internals of the Linux math coprocessor 1599 emulation can be found in <file:arch/x86/math-emu/README>. 1600 1601 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1602 kernel, it won't hurt. 1603 1604config MTRR 1605 def_bool y 1606 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1607 ---help--- 1608 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1609 the Memory Type Range Registers (MTRRs) may be used to control 1610 processor access to memory ranges. This is most useful if you have 1611 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1612 allows bus write transfers to be combined into a larger transfer 1613 before bursting over the PCI/AGP bus. This can increase performance 1614 of image write operations 2.5 times or more. Saying Y here creates a 1615 /proc/mtrr file which may be used to manipulate your processor's 1616 MTRRs. Typically the X server should use this. 1617 1618 This code has a reasonably generic interface so that similar 1619 control registers on other processors can be easily supported 1620 as well: 1621 1622 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1623 Registers (ARRs) which provide a similar functionality to MTRRs. For 1624 these, the ARRs are used to emulate the MTRRs. 1625 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1626 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1627 write-combining. All of these processors are supported by this code 1628 and it makes sense to say Y here if you have one of them. 1629 1630 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1631 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1632 can lead to all sorts of problems, so it's good to say Y here. 1633 1634 You can safely say Y even if your machine doesn't have MTRRs, you'll 1635 just add about 9 KB to your kernel. 1636 1637 See <file:Documentation/x86/mtrr.txt> for more information. 1638 1639config MTRR_SANITIZER 1640 def_bool y 1641 prompt "MTRR cleanup support" 1642 depends on MTRR 1643 ---help--- 1644 Convert MTRR layout from continuous to discrete, so X drivers can 1645 add writeback entries. 1646 1647 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1648 The largest mtrr entry size for a continuous block can be set with 1649 mtrr_chunk_size. 1650 1651 If unsure, say Y. 1652 1653config MTRR_SANITIZER_ENABLE_DEFAULT 1654 int "MTRR cleanup enable value (0-1)" 1655 range 0 1 1656 default "0" 1657 depends on MTRR_SANITIZER 1658 ---help--- 1659 Enable mtrr cleanup default value 1660 1661config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1662 int "MTRR cleanup spare reg num (0-7)" 1663 range 0 7 1664 default "1" 1665 depends on MTRR_SANITIZER 1666 ---help--- 1667 mtrr cleanup spare entries default, it can be changed via 1668 mtrr_spare_reg_nr=N on the kernel command line. 1669 1670config X86_PAT 1671 def_bool y 1672 prompt "x86 PAT support" if EXPERT 1673 depends on MTRR 1674 ---help--- 1675 Use PAT attributes to setup page level cache control. 1676 1677 PATs are the modern equivalents of MTRRs and are much more 1678 flexible than MTRRs. 1679 1680 Say N here if you see bootup problems (boot crash, boot hang, 1681 spontaneous reboots) or a non-working video driver. 1682 1683 If unsure, say Y. 1684 1685config ARCH_USES_PG_UNCACHED 1686 def_bool y 1687 depends on X86_PAT 1688 1689config ARCH_RANDOM 1690 def_bool y 1691 prompt "x86 architectural random number generator" if EXPERT 1692 ---help--- 1693 Enable the x86 architectural RDRAND instruction 1694 (Intel Bull Mountain technology) to generate random numbers. 1695 If supported, this is a high bandwidth, cryptographically 1696 secure hardware random number generator. 1697 1698config X86_SMAP 1699 def_bool y 1700 prompt "Supervisor Mode Access Prevention" if EXPERT 1701 ---help--- 1702 Supervisor Mode Access Prevention (SMAP) is a security 1703 feature in newer Intel processors. There is a small 1704 performance cost if this enabled and turned on; there is 1705 also a small increase in the kernel size if this is enabled. 1706 1707 If unsure, say Y. 1708 1709config X86_INTEL_MPX 1710 prompt "Intel MPX (Memory Protection Extensions)" 1711 def_bool n 1712 depends on CPU_SUP_INTEL 1713 ---help--- 1714 MPX provides hardware features that can be used in 1715 conjunction with compiler-instrumented code to check 1716 memory references. It is designed to detect buffer 1717 overflow or underflow bugs. 1718 1719 This option enables running applications which are 1720 instrumented or otherwise use MPX. It does not use MPX 1721 itself inside the kernel or to protect the kernel 1722 against bad memory references. 1723 1724 Enabling this option will make the kernel larger: 1725 ~8k of kernel text and 36 bytes of data on a 64-bit 1726 defconfig. It adds a long to the 'mm_struct' which 1727 will increase the kernel memory overhead of each 1728 process and adds some branches to paths used during 1729 exec() and munmap(). 1730 1731 For details, see Documentation/x86/intel_mpx.txt 1732 1733 If unsure, say N. 1734 1735config X86_INTEL_MEMORY_PROTECTION_KEYS 1736 prompt "Intel Memory Protection Keys" 1737 def_bool y 1738 # Note: only available in 64-bit mode 1739 depends on CPU_SUP_INTEL && X86_64 1740 ---help--- 1741 Memory Protection Keys provides a mechanism for enforcing 1742 page-based protections, but without requiring modification of the 1743 page tables when an application changes protection domains. 1744 1745 For details, see Documentation/x86/protection-keys.txt 1746 1747 If unsure, say y. 1748 1749config EFI 1750 bool "EFI runtime service support" 1751 depends on ACPI 1752 select UCS2_STRING 1753 select EFI_RUNTIME_WRAPPERS 1754 ---help--- 1755 This enables the kernel to use EFI runtime services that are 1756 available (such as the EFI variable services). 1757 1758 This option is only useful on systems that have EFI firmware. 1759 In addition, you should use the latest ELILO loader available 1760 at <http://elilo.sourceforge.net> in order to take advantage 1761 of EFI runtime services. However, even with this option, the 1762 resultant kernel should continue to boot on existing non-EFI 1763 platforms. 1764 1765config EFI_STUB 1766 bool "EFI stub support" 1767 depends on EFI && !X86_USE_3DNOW 1768 select RELOCATABLE 1769 ---help--- 1770 This kernel feature allows a bzImage to be loaded directly 1771 by EFI firmware without the use of a bootloader. 1772 1773 See Documentation/efi-stub.txt for more information. 1774 1775config EFI_MIXED 1776 bool "EFI mixed-mode support" 1777 depends on EFI_STUB && X86_64 1778 ---help--- 1779 Enabling this feature allows a 64-bit kernel to be booted 1780 on a 32-bit firmware, provided that your CPU supports 64-bit 1781 mode. 1782 1783 Note that it is not possible to boot a mixed-mode enabled 1784 kernel via the EFI boot stub - a bootloader that supports 1785 the EFI handover protocol must be used. 1786 1787 If unsure, say N. 1788 1789config SECCOMP 1790 def_bool y 1791 prompt "Enable seccomp to safely compute untrusted bytecode" 1792 ---help--- 1793 This kernel feature is useful for number crunching applications 1794 that may need to compute untrusted bytecode during their 1795 execution. By using pipes or other transports made available to 1796 the process as file descriptors supporting the read/write 1797 syscalls, it's possible to isolate those applications in 1798 their own address space using seccomp. Once seccomp is 1799 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1800 and the task is only allowed to execute a few safe syscalls 1801 defined by each seccomp mode. 1802 1803 If unsure, say Y. Only embedded should say N here. 1804 1805source kernel/Kconfig.hz 1806 1807config KEXEC 1808 bool "kexec system call" 1809 select KEXEC_CORE 1810 ---help--- 1811 kexec is a system call that implements the ability to shutdown your 1812 current kernel, and to start another kernel. It is like a reboot 1813 but it is independent of the system firmware. And like a reboot 1814 you can start any kernel with it, not just Linux. 1815 1816 The name comes from the similarity to the exec system call. 1817 1818 It is an ongoing process to be certain the hardware in a machine 1819 is properly shutdown, so do not be surprised if this code does not 1820 initially work for you. As of this writing the exact hardware 1821 interface is strongly in flux, so no good recommendation can be 1822 made. 1823 1824config KEXEC_FILE 1825 bool "kexec file based system call" 1826 select KEXEC_CORE 1827 select BUILD_BIN2C 1828 depends on X86_64 1829 depends on CRYPTO=y 1830 depends on CRYPTO_SHA256=y 1831 ---help--- 1832 This is new version of kexec system call. This system call is 1833 file based and takes file descriptors as system call argument 1834 for kernel and initramfs as opposed to list of segments as 1835 accepted by previous system call. 1836 1837config KEXEC_VERIFY_SIG 1838 bool "Verify kernel signature during kexec_file_load() syscall" 1839 depends on KEXEC_FILE 1840 ---help--- 1841 This option makes kernel signature verification mandatory for 1842 the kexec_file_load() syscall. 1843 1844 In addition to that option, you need to enable signature 1845 verification for the corresponding kernel image type being 1846 loaded in order for this to work. 1847 1848config KEXEC_BZIMAGE_VERIFY_SIG 1849 bool "Enable bzImage signature verification support" 1850 depends on KEXEC_VERIFY_SIG 1851 depends on SIGNED_PE_FILE_VERIFICATION 1852 select SYSTEM_TRUSTED_KEYRING 1853 ---help--- 1854 Enable bzImage signature verification support. 1855 1856config CRASH_DUMP 1857 bool "kernel crash dumps" 1858 depends on X86_64 || (X86_32 && HIGHMEM) 1859 ---help--- 1860 Generate crash dump after being started by kexec. 1861 This should be normally only set in special crash dump kernels 1862 which are loaded in the main kernel with kexec-tools into 1863 a specially reserved region and then later executed after 1864 a crash by kdump/kexec. The crash dump kernel must be compiled 1865 to a memory address not used by the main kernel or BIOS using 1866 PHYSICAL_START, or it must be built as a relocatable image 1867 (CONFIG_RELOCATABLE=y). 1868 For more details see Documentation/kdump/kdump.txt 1869 1870config KEXEC_JUMP 1871 bool "kexec jump" 1872 depends on KEXEC && HIBERNATION 1873 ---help--- 1874 Jump between original kernel and kexeced kernel and invoke 1875 code in physical address mode via KEXEC 1876 1877config PHYSICAL_START 1878 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1879 default "0x1000000" 1880 ---help--- 1881 This gives the physical address where the kernel is loaded. 1882 1883 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1884 bzImage will decompress itself to above physical address and 1885 run from there. Otherwise, bzImage will run from the address where 1886 it has been loaded by the boot loader and will ignore above physical 1887 address. 1888 1889 In normal kdump cases one does not have to set/change this option 1890 as now bzImage can be compiled as a completely relocatable image 1891 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1892 address. This option is mainly useful for the folks who don't want 1893 to use a bzImage for capturing the crash dump and want to use a 1894 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1895 to be specifically compiled to run from a specific memory area 1896 (normally a reserved region) and this option comes handy. 1897 1898 So if you are using bzImage for capturing the crash dump, 1899 leave the value here unchanged to 0x1000000 and set 1900 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1901 for capturing the crash dump change this value to start of 1902 the reserved region. In other words, it can be set based on 1903 the "X" value as specified in the "crashkernel=YM@XM" 1904 command line boot parameter passed to the panic-ed 1905 kernel. Please take a look at Documentation/kdump/kdump.txt 1906 for more details about crash dumps. 1907 1908 Usage of bzImage for capturing the crash dump is recommended as 1909 one does not have to build two kernels. Same kernel can be used 1910 as production kernel and capture kernel. Above option should have 1911 gone away after relocatable bzImage support is introduced. But it 1912 is present because there are users out there who continue to use 1913 vmlinux for dump capture. This option should go away down the 1914 line. 1915 1916 Don't change this unless you know what you are doing. 1917 1918config RELOCATABLE 1919 bool "Build a relocatable kernel" 1920 default y 1921 ---help--- 1922 This builds a kernel image that retains relocation information 1923 so it can be loaded someplace besides the default 1MB. 1924 The relocations tend to make the kernel binary about 10% larger, 1925 but are discarded at runtime. 1926 1927 One use is for the kexec on panic case where the recovery kernel 1928 must live at a different physical address than the primary 1929 kernel. 1930 1931 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1932 it has been loaded at and the compile time physical address 1933 (CONFIG_PHYSICAL_START) is used as the minimum location. 1934 1935config RANDOMIZE_BASE 1936 bool "Randomize the address of the kernel image (KASLR)" 1937 depends on RELOCATABLE 1938 default n 1939 ---help--- 1940 In support of Kernel Address Space Layout Randomization (KASLR), 1941 this randomizes the physical address at which the kernel image 1942 is decompressed and the virtual address where the kernel 1943 image is mapped, as a security feature that deters exploit 1944 attempts relying on knowledge of the location of kernel 1945 code internals. 1946 1947 On 64-bit, the kernel physical and virtual addresses are 1948 randomized separately. The physical address will be anywhere 1949 between 16MB and the top of physical memory (up to 64TB). The 1950 virtual address will be randomized from 16MB up to 1GB (9 bits 1951 of entropy). Note that this also reduces the memory space 1952 available to kernel modules from 1.5GB to 1GB. 1953 1954 On 32-bit, the kernel physical and virtual addresses are 1955 randomized together. They will be randomized from 16MB up to 1956 512MB (8 bits of entropy). 1957 1958 Entropy is generated using the RDRAND instruction if it is 1959 supported. If RDTSC is supported, its value is mixed into 1960 the entropy pool as well. If neither RDRAND nor RDTSC are 1961 supported, then entropy is read from the i8254 timer. The 1962 usable entropy is limited by the kernel being built using 1963 2GB addressing, and that PHYSICAL_ALIGN must be at a 1964 minimum of 2MB. As a result, only 10 bits of entropy are 1965 theoretically possible, but the implementations are further 1966 limited due to memory layouts. 1967 1968 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot 1969 time. To enable it, boot with "kaslr" on the kernel command 1970 line (which will also disable hibernation). 1971 1972 If unsure, say N. 1973 1974# Relocation on x86 needs some additional build support 1975config X86_NEED_RELOCS 1976 def_bool y 1977 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1978 1979config PHYSICAL_ALIGN 1980 hex "Alignment value to which kernel should be aligned" 1981 default "0x200000" 1982 range 0x2000 0x1000000 if X86_32 1983 range 0x200000 0x1000000 if X86_64 1984 ---help--- 1985 This value puts the alignment restrictions on physical address 1986 where kernel is loaded and run from. Kernel is compiled for an 1987 address which meets above alignment restriction. 1988 1989 If bootloader loads the kernel at a non-aligned address and 1990 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1991 address aligned to above value and run from there. 1992 1993 If bootloader loads the kernel at a non-aligned address and 1994 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1995 load address and decompress itself to the address it has been 1996 compiled for and run from there. The address for which kernel is 1997 compiled already meets above alignment restrictions. Hence the 1998 end result is that kernel runs from a physical address meeting 1999 above alignment restrictions. 2000 2001 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2002 this value must be a multiple of 0x200000. 2003 2004 Don't change this unless you know what you are doing. 2005 2006config RANDOMIZE_MEMORY 2007 bool "Randomize the kernel memory sections" 2008 depends on X86_64 2009 depends on RANDOMIZE_BASE 2010 default RANDOMIZE_BASE 2011 ---help--- 2012 Randomizes the base virtual address of kernel memory sections 2013 (physical memory mapping, vmalloc & vmemmap). This security feature 2014 makes exploits relying on predictable memory locations less reliable. 2015 2016 The order of allocations remains unchanged. Entropy is generated in 2017 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2018 configuration have in average 30,000 different possible virtual 2019 addresses for each memory section. 2020 2021 If unsure, say N. 2022 2023config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2024 hex "Physical memory mapping padding" if EXPERT 2025 depends on RANDOMIZE_MEMORY 2026 default "0xa" if MEMORY_HOTPLUG 2027 default "0x0" 2028 range 0x1 0x40 if MEMORY_HOTPLUG 2029 range 0x0 0x40 2030 ---help--- 2031 Define the padding in terabytes added to the existing physical 2032 memory size during kernel memory randomization. It is useful 2033 for memory hotplug support but reduces the entropy available for 2034 address randomization. 2035 2036 If unsure, leave at the default value. 2037 2038config HOTPLUG_CPU 2039 bool "Support for hot-pluggable CPUs" 2040 depends on SMP 2041 ---help--- 2042 Say Y here to allow turning CPUs off and on. CPUs can be 2043 controlled through /sys/devices/system/cpu. 2044 ( Note: power management support will enable this option 2045 automatically on SMP systems. ) 2046 Say N if you want to disable CPU hotplug. 2047 2048config BOOTPARAM_HOTPLUG_CPU0 2049 bool "Set default setting of cpu0_hotpluggable" 2050 default n 2051 depends on HOTPLUG_CPU 2052 ---help--- 2053 Set whether default state of cpu0_hotpluggable is on or off. 2054 2055 Say Y here to enable CPU0 hotplug by default. If this switch 2056 is turned on, there is no need to give cpu0_hotplug kernel 2057 parameter and the CPU0 hotplug feature is enabled by default. 2058 2059 Please note: there are two known CPU0 dependencies if you want 2060 to enable the CPU0 hotplug feature either by this switch or by 2061 cpu0_hotplug kernel parameter. 2062 2063 First, resume from hibernate or suspend always starts from CPU0. 2064 So hibernate and suspend are prevented if CPU0 is offline. 2065 2066 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2067 offline if any interrupt can not migrate out of CPU0. There may 2068 be other CPU0 dependencies. 2069 2070 Please make sure the dependencies are under your control before 2071 you enable this feature. 2072 2073 Say N if you don't want to enable CPU0 hotplug feature by default. 2074 You still can enable the CPU0 hotplug feature at boot by kernel 2075 parameter cpu0_hotplug. 2076 2077config DEBUG_HOTPLUG_CPU0 2078 def_bool n 2079 prompt "Debug CPU0 hotplug" 2080 depends on HOTPLUG_CPU 2081 ---help--- 2082 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2083 soon as possible and boots up userspace with CPU0 offlined. User 2084 can online CPU0 back after boot time. 2085 2086 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2087 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2088 compilation or giving cpu0_hotplug kernel parameter at boot. 2089 2090 If unsure, say N. 2091 2092config COMPAT_VDSO 2093 def_bool n 2094 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2095 depends on X86_32 || IA32_EMULATION 2096 ---help--- 2097 Certain buggy versions of glibc will crash if they are 2098 presented with a 32-bit vDSO that is not mapped at the address 2099 indicated in its segment table. 2100 2101 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2102 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2103 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2104 the only released version with the bug, but OpenSUSE 9 2105 contains a buggy "glibc 2.3.2". 2106 2107 The symptom of the bug is that everything crashes on startup, saying: 2108 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2109 2110 Saying Y here changes the default value of the vdso32 boot 2111 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2112 This works around the glibc bug but hurts performance. 2113 2114 If unsure, say N: if you are compiling your own kernel, you 2115 are unlikely to be using a buggy version of glibc. 2116 2117choice 2118 prompt "vsyscall table for legacy applications" 2119 depends on X86_64 2120 default LEGACY_VSYSCALL_EMULATE 2121 help 2122 Legacy user code that does not know how to find the vDSO expects 2123 to be able to issue three syscalls by calling fixed addresses in 2124 kernel space. Since this location is not randomized with ASLR, 2125 it can be used to assist security vulnerability exploitation. 2126 2127 This setting can be changed at boot time via the kernel command 2128 line parameter vsyscall=[native|emulate|none]. 2129 2130 On a system with recent enough glibc (2.14 or newer) and no 2131 static binaries, you can say None without a performance penalty 2132 to improve security. 2133 2134 If unsure, select "Emulate". 2135 2136 config LEGACY_VSYSCALL_NATIVE 2137 bool "Native" 2138 help 2139 Actual executable code is located in the fixed vsyscall 2140 address mapping, implementing time() efficiently. Since 2141 this makes the mapping executable, it can be used during 2142 security vulnerability exploitation (traditionally as 2143 ROP gadgets). This configuration is not recommended. 2144 2145 config LEGACY_VSYSCALL_EMULATE 2146 bool "Emulate" 2147 help 2148 The kernel traps and emulates calls into the fixed 2149 vsyscall address mapping. This makes the mapping 2150 non-executable, but it still contains known contents, 2151 which could be used in certain rare security vulnerability 2152 exploits. This configuration is recommended when userspace 2153 still uses the vsyscall area. 2154 2155 config LEGACY_VSYSCALL_NONE 2156 bool "None" 2157 help 2158 There will be no vsyscall mapping at all. This will 2159 eliminate any risk of ASLR bypass due to the vsyscall 2160 fixed address mapping. Attempts to use the vsyscalls 2161 will be reported to dmesg, so that either old or 2162 malicious userspace programs can be identified. 2163 2164endchoice 2165 2166config CMDLINE_BOOL 2167 bool "Built-in kernel command line" 2168 ---help--- 2169 Allow for specifying boot arguments to the kernel at 2170 build time. On some systems (e.g. embedded ones), it is 2171 necessary or convenient to provide some or all of the 2172 kernel boot arguments with the kernel itself (that is, 2173 to not rely on the boot loader to provide them.) 2174 2175 To compile command line arguments into the kernel, 2176 set this option to 'Y', then fill in the 2177 boot arguments in CONFIG_CMDLINE. 2178 2179 Systems with fully functional boot loaders (i.e. non-embedded) 2180 should leave this option set to 'N'. 2181 2182config CMDLINE 2183 string "Built-in kernel command string" 2184 depends on CMDLINE_BOOL 2185 default "" 2186 ---help--- 2187 Enter arguments here that should be compiled into the kernel 2188 image and used at boot time. If the boot loader provides a 2189 command line at boot time, it is appended to this string to 2190 form the full kernel command line, when the system boots. 2191 2192 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2193 change this behavior. 2194 2195 In most cases, the command line (whether built-in or provided 2196 by the boot loader) should specify the device for the root 2197 file system. 2198 2199config CMDLINE_OVERRIDE 2200 bool "Built-in command line overrides boot loader arguments" 2201 depends on CMDLINE_BOOL 2202 ---help--- 2203 Set this option to 'Y' to have the kernel ignore the boot loader 2204 command line, and use ONLY the built-in command line. 2205 2206 This is used to work around broken boot loaders. This should 2207 be set to 'N' under normal conditions. 2208 2209config MODIFY_LDT_SYSCALL 2210 bool "Enable the LDT (local descriptor table)" if EXPERT 2211 default y 2212 ---help--- 2213 Linux can allow user programs to install a per-process x86 2214 Local Descriptor Table (LDT) using the modify_ldt(2) system 2215 call. This is required to run 16-bit or segmented code such as 2216 DOSEMU or some Wine programs. It is also used by some very old 2217 threading libraries. 2218 2219 Enabling this feature adds a small amount of overhead to 2220 context switches and increases the low-level kernel attack 2221 surface. Disabling it removes the modify_ldt(2) system call. 2222 2223 Saying 'N' here may make sense for embedded or server kernels. 2224 2225source "kernel/livepatch/Kconfig" 2226 2227endmenu 2228 2229config ARCH_ENABLE_MEMORY_HOTPLUG 2230 def_bool y 2231 depends on X86_64 || (X86_32 && HIGHMEM) 2232 2233config ARCH_ENABLE_MEMORY_HOTREMOVE 2234 def_bool y 2235 depends on MEMORY_HOTPLUG 2236 2237config USE_PERCPU_NUMA_NODE_ID 2238 def_bool y 2239 depends on NUMA 2240 2241config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2242 def_bool y 2243 depends on X86_64 || X86_PAE 2244 2245config ARCH_ENABLE_HUGEPAGE_MIGRATION 2246 def_bool y 2247 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2248 2249menu "Power management and ACPI options" 2250 2251config ARCH_HIBERNATION_HEADER 2252 def_bool y 2253 depends on X86_64 && HIBERNATION 2254 2255source "kernel/power/Kconfig" 2256 2257source "drivers/acpi/Kconfig" 2258 2259source "drivers/sfi/Kconfig" 2260 2261config X86_APM_BOOT 2262 def_bool y 2263 depends on APM 2264 2265menuconfig APM 2266 tristate "APM (Advanced Power Management) BIOS support" 2267 depends on X86_32 && PM_SLEEP 2268 ---help--- 2269 APM is a BIOS specification for saving power using several different 2270 techniques. This is mostly useful for battery powered laptops with 2271 APM compliant BIOSes. If you say Y here, the system time will be 2272 reset after a RESUME operation, the /proc/apm device will provide 2273 battery status information, and user-space programs will receive 2274 notification of APM "events" (e.g. battery status change). 2275 2276 If you select "Y" here, you can disable actual use of the APM 2277 BIOS by passing the "apm=off" option to the kernel at boot time. 2278 2279 Note that the APM support is almost completely disabled for 2280 machines with more than one CPU. 2281 2282 In order to use APM, you will need supporting software. For location 2283 and more information, read <file:Documentation/power/apm-acpi.txt> 2284 and the Battery Powered Linux mini-HOWTO, available from 2285 <http://www.tldp.org/docs.html#howto>. 2286 2287 This driver does not spin down disk drives (see the hdparm(8) 2288 manpage ("man 8 hdparm") for that), and it doesn't turn off 2289 VESA-compliant "green" monitors. 2290 2291 This driver does not support the TI 4000M TravelMate and the ACER 2292 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2293 desktop machines also don't have compliant BIOSes, and this driver 2294 may cause those machines to panic during the boot phase. 2295 2296 Generally, if you don't have a battery in your machine, there isn't 2297 much point in using this driver and you should say N. If you get 2298 random kernel OOPSes or reboots that don't seem to be related to 2299 anything, try disabling/enabling this option (or disabling/enabling 2300 APM in your BIOS). 2301 2302 Some other things you should try when experiencing seemingly random, 2303 "weird" problems: 2304 2305 1) make sure that you have enough swap space and that it is 2306 enabled. 2307 2) pass the "no-hlt" option to the kernel 2308 3) switch on floating point emulation in the kernel and pass 2309 the "no387" option to the kernel 2310 4) pass the "floppy=nodma" option to the kernel 2311 5) pass the "mem=4M" option to the kernel (thereby disabling 2312 all but the first 4 MB of RAM) 2313 6) make sure that the CPU is not over clocked. 2314 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2315 8) disable the cache from your BIOS settings 2316 9) install a fan for the video card or exchange video RAM 2317 10) install a better fan for the CPU 2318 11) exchange RAM chips 2319 12) exchange the motherboard. 2320 2321 To compile this driver as a module, choose M here: the 2322 module will be called apm. 2323 2324if APM 2325 2326config APM_IGNORE_USER_SUSPEND 2327 bool "Ignore USER SUSPEND" 2328 ---help--- 2329 This option will ignore USER SUSPEND requests. On machines with a 2330 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2331 series notebooks, it is necessary to say Y because of a BIOS bug. 2332 2333config APM_DO_ENABLE 2334 bool "Enable PM at boot time" 2335 ---help--- 2336 Enable APM features at boot time. From page 36 of the APM BIOS 2337 specification: "When disabled, the APM BIOS does not automatically 2338 power manage devices, enter the Standby State, enter the Suspend 2339 State, or take power saving steps in response to CPU Idle calls." 2340 This driver will make CPU Idle calls when Linux is idle (unless this 2341 feature is turned off -- see "Do CPU IDLE calls", below). This 2342 should always save battery power, but more complicated APM features 2343 will be dependent on your BIOS implementation. You may need to turn 2344 this option off if your computer hangs at boot time when using APM 2345 support, or if it beeps continuously instead of suspending. Turn 2346 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2347 T400CDT. This is off by default since most machines do fine without 2348 this feature. 2349 2350config APM_CPU_IDLE 2351 depends on CPU_IDLE 2352 bool "Make CPU Idle calls when idle" 2353 ---help--- 2354 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2355 On some machines, this can activate improved power savings, such as 2356 a slowed CPU clock rate, when the machine is idle. These idle calls 2357 are made after the idle loop has run for some length of time (e.g., 2358 333 mS). On some machines, this will cause a hang at boot time or 2359 whenever the CPU becomes idle. (On machines with more than one CPU, 2360 this option does nothing.) 2361 2362config APM_DISPLAY_BLANK 2363 bool "Enable console blanking using APM" 2364 ---help--- 2365 Enable console blanking using the APM. Some laptops can use this to 2366 turn off the LCD backlight when the screen blanker of the Linux 2367 virtual console blanks the screen. Note that this is only used by 2368 the virtual console screen blanker, and won't turn off the backlight 2369 when using the X Window system. This also doesn't have anything to 2370 do with your VESA-compliant power-saving monitor. Further, this 2371 option doesn't work for all laptops -- it might not turn off your 2372 backlight at all, or it might print a lot of errors to the console, 2373 especially if you are using gpm. 2374 2375config APM_ALLOW_INTS 2376 bool "Allow interrupts during APM BIOS calls" 2377 ---help--- 2378 Normally we disable external interrupts while we are making calls to 2379 the APM BIOS as a measure to lessen the effects of a badly behaving 2380 BIOS implementation. The BIOS should reenable interrupts if it 2381 needs to. Unfortunately, some BIOSes do not -- especially those in 2382 many of the newer IBM Thinkpads. If you experience hangs when you 2383 suspend, try setting this to Y. Otherwise, say N. 2384 2385endif # APM 2386 2387source "drivers/cpufreq/Kconfig" 2388 2389source "drivers/cpuidle/Kconfig" 2390 2391source "drivers/idle/Kconfig" 2392 2393endmenu 2394 2395 2396menu "Bus options (PCI etc.)" 2397 2398config PCI 2399 bool "PCI support" 2400 default y 2401 ---help--- 2402 Find out whether you have a PCI motherboard. PCI is the name of a 2403 bus system, i.e. the way the CPU talks to the other stuff inside 2404 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2405 VESA. If you have PCI, say Y, otherwise N. 2406 2407choice 2408 prompt "PCI access mode" 2409 depends on X86_32 && PCI 2410 default PCI_GOANY 2411 ---help--- 2412 On PCI systems, the BIOS can be used to detect the PCI devices and 2413 determine their configuration. However, some old PCI motherboards 2414 have BIOS bugs and may crash if this is done. Also, some embedded 2415 PCI-based systems don't have any BIOS at all. Linux can also try to 2416 detect the PCI hardware directly without using the BIOS. 2417 2418 With this option, you can specify how Linux should detect the 2419 PCI devices. If you choose "BIOS", the BIOS will be used, 2420 if you choose "Direct", the BIOS won't be used, and if you 2421 choose "MMConfig", then PCI Express MMCONFIG will be used. 2422 If you choose "Any", the kernel will try MMCONFIG, then the 2423 direct access method and falls back to the BIOS if that doesn't 2424 work. If unsure, go with the default, which is "Any". 2425 2426config PCI_GOBIOS 2427 bool "BIOS" 2428 2429config PCI_GOMMCONFIG 2430 bool "MMConfig" 2431 2432config PCI_GODIRECT 2433 bool "Direct" 2434 2435config PCI_GOOLPC 2436 bool "OLPC XO-1" 2437 depends on OLPC 2438 2439config PCI_GOANY 2440 bool "Any" 2441 2442endchoice 2443 2444config PCI_BIOS 2445 def_bool y 2446 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2447 2448# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2449config PCI_DIRECT 2450 def_bool y 2451 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2452 2453config PCI_MMCONFIG 2454 def_bool y 2455 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2456 2457config PCI_OLPC 2458 def_bool y 2459 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2460 2461config PCI_XEN 2462 def_bool y 2463 depends on PCI && XEN 2464 select SWIOTLB_XEN 2465 2466config PCI_DOMAINS 2467 def_bool y 2468 depends on PCI 2469 2470config PCI_MMCONFIG 2471 bool "Support mmconfig PCI config space access" 2472 depends on X86_64 && PCI && ACPI 2473 2474config PCI_CNB20LE_QUIRK 2475 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2476 depends on PCI 2477 help 2478 Read the PCI windows out of the CNB20LE host bridge. This allows 2479 PCI hotplug to work on systems with the CNB20LE chipset which do 2480 not have ACPI. 2481 2482 There's no public spec for this chipset, and this functionality 2483 is known to be incomplete. 2484 2485 You should say N unless you know you need this. 2486 2487source "drivers/pci/Kconfig" 2488 2489config ISA_BUS 2490 bool "ISA-style bus support on modern systems" if EXPERT 2491 select ISA_BUS_API 2492 help 2493 Enables ISA-style drivers on modern systems. This is necessary to 2494 support PC/104 devices on X86_64 platforms. 2495 2496 If unsure, say N. 2497 2498# x86_64 have no ISA slots, but can have ISA-style DMA. 2499config ISA_DMA_API 2500 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2501 default y 2502 help 2503 Enables ISA-style DMA support for devices requiring such controllers. 2504 If unsure, say Y. 2505 2506if X86_32 2507 2508config ISA 2509 bool "ISA support" 2510 ---help--- 2511 Find out whether you have ISA slots on your motherboard. ISA is the 2512 name of a bus system, i.e. the way the CPU talks to the other stuff 2513 inside your box. Other bus systems are PCI, EISA, MicroChannel 2514 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2515 newer boards don't support it. If you have ISA, say Y, otherwise N. 2516 2517config EISA 2518 bool "EISA support" 2519 depends on ISA 2520 ---help--- 2521 The Extended Industry Standard Architecture (EISA) bus was 2522 developed as an open alternative to the IBM MicroChannel bus. 2523 2524 The EISA bus provided some of the features of the IBM MicroChannel 2525 bus while maintaining backward compatibility with cards made for 2526 the older ISA bus. The EISA bus saw limited use between 1988 and 2527 1995 when it was made obsolete by the PCI bus. 2528 2529 Say Y here if you are building a kernel for an EISA-based machine. 2530 2531 Otherwise, say N. 2532 2533source "drivers/eisa/Kconfig" 2534 2535config SCx200 2536 tristate "NatSemi SCx200 support" 2537 ---help--- 2538 This provides basic support for National Semiconductor's 2539 (now AMD's) Geode processors. The driver probes for the 2540 PCI-IDs of several on-chip devices, so its a good dependency 2541 for other scx200_* drivers. 2542 2543 If compiled as a module, the driver is named scx200. 2544 2545config SCx200HR_TIMER 2546 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2547 depends on SCx200 2548 default y 2549 ---help--- 2550 This driver provides a clocksource built upon the on-chip 2551 27MHz high-resolution timer. Its also a workaround for 2552 NSC Geode SC-1100's buggy TSC, which loses time when the 2553 processor goes idle (as is done by the scheduler). The 2554 other workaround is idle=poll boot option. 2555 2556config OLPC 2557 bool "One Laptop Per Child support" 2558 depends on !X86_PAE 2559 select GPIOLIB 2560 select OF 2561 select OF_PROMTREE 2562 select IRQ_DOMAIN 2563 ---help--- 2564 Add support for detecting the unique features of the OLPC 2565 XO hardware. 2566 2567config OLPC_XO1_PM 2568 bool "OLPC XO-1 Power Management" 2569 depends on OLPC && MFD_CS5535 && PM_SLEEP 2570 select MFD_CORE 2571 ---help--- 2572 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2573 2574config OLPC_XO1_RTC 2575 bool "OLPC XO-1 Real Time Clock" 2576 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2577 ---help--- 2578 Add support for the XO-1 real time clock, which can be used as a 2579 programmable wakeup source. 2580 2581config OLPC_XO1_SCI 2582 bool "OLPC XO-1 SCI extras" 2583 depends on OLPC && OLPC_XO1_PM 2584 depends on INPUT=y 2585 select POWER_SUPPLY 2586 select GPIO_CS5535 2587 select MFD_CORE 2588 ---help--- 2589 Add support for SCI-based features of the OLPC XO-1 laptop: 2590 - EC-driven system wakeups 2591 - Power button 2592 - Ebook switch 2593 - Lid switch 2594 - AC adapter status updates 2595 - Battery status updates 2596 2597config OLPC_XO15_SCI 2598 bool "OLPC XO-1.5 SCI extras" 2599 depends on OLPC && ACPI 2600 select POWER_SUPPLY 2601 ---help--- 2602 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2603 - EC-driven system wakeups 2604 - AC adapter status updates 2605 - Battery status updates 2606 2607config ALIX 2608 bool "PCEngines ALIX System Support (LED setup)" 2609 select GPIOLIB 2610 ---help--- 2611 This option enables system support for the PCEngines ALIX. 2612 At present this just sets up LEDs for GPIO control on 2613 ALIX2/3/6 boards. However, other system specific setup should 2614 get added here. 2615 2616 Note: You must still enable the drivers for GPIO and LED support 2617 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2618 2619 Note: You have to set alix.force=1 for boards with Award BIOS. 2620 2621config NET5501 2622 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2623 select GPIOLIB 2624 ---help--- 2625 This option enables system support for the Soekris Engineering net5501. 2626 2627config GEOS 2628 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2629 select GPIOLIB 2630 depends on DMI 2631 ---help--- 2632 This option enables system support for the Traverse Technologies GEOS. 2633 2634config TS5500 2635 bool "Technologic Systems TS-5500 platform support" 2636 depends on MELAN 2637 select CHECK_SIGNATURE 2638 select NEW_LEDS 2639 select LEDS_CLASS 2640 ---help--- 2641 This option enables system support for the Technologic Systems TS-5500. 2642 2643endif # X86_32 2644 2645config AMD_NB 2646 def_bool y 2647 depends on CPU_SUP_AMD && PCI 2648 2649source "drivers/pcmcia/Kconfig" 2650 2651config RAPIDIO 2652 tristate "RapidIO support" 2653 depends on PCI 2654 default n 2655 help 2656 If enabled this option will include drivers and the core 2657 infrastructure code to support RapidIO interconnect devices. 2658 2659source "drivers/rapidio/Kconfig" 2660 2661config X86_SYSFB 2662 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2663 help 2664 Firmwares often provide initial graphics framebuffers so the BIOS, 2665 bootloader or kernel can show basic video-output during boot for 2666 user-guidance and debugging. Historically, x86 used the VESA BIOS 2667 Extensions and EFI-framebuffers for this, which are mostly limited 2668 to x86. 2669 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2670 framebuffers so the new generic system-framebuffer drivers can be 2671 used on x86. If the framebuffer is not compatible with the generic 2672 modes, it is adverticed as fallback platform framebuffer so legacy 2673 drivers like efifb, vesafb and uvesafb can pick it up. 2674 If this option is not selected, all system framebuffers are always 2675 marked as fallback platform framebuffers as usual. 2676 2677 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2678 not be able to pick up generic system framebuffers if this option 2679 is selected. You are highly encouraged to enable simplefb as 2680 replacement if you select this option. simplefb can correctly deal 2681 with generic system framebuffers. But you should still keep vesafb 2682 and others enabled as fallback if a system framebuffer is 2683 incompatible with simplefb. 2684 2685 If unsure, say Y. 2686 2687endmenu 2688 2689 2690menu "Executable file formats / Emulations" 2691 2692source "fs/Kconfig.binfmt" 2693 2694config IA32_EMULATION 2695 bool "IA32 Emulation" 2696 depends on X86_64 2697 select BINFMT_ELF 2698 select COMPAT_BINFMT_ELF 2699 select ARCH_WANT_OLD_COMPAT_IPC 2700 ---help--- 2701 Include code to run legacy 32-bit programs under a 2702 64-bit kernel. You should likely turn this on, unless you're 2703 100% sure that you don't have any 32-bit programs left. 2704 2705config IA32_AOUT 2706 tristate "IA32 a.out support" 2707 depends on IA32_EMULATION 2708 ---help--- 2709 Support old a.out binaries in the 32bit emulation. 2710 2711config X86_X32 2712 bool "x32 ABI for 64-bit mode" 2713 depends on X86_64 2714 ---help--- 2715 Include code to run binaries for the x32 native 32-bit ABI 2716 for 64-bit processors. An x32 process gets access to the 2717 full 64-bit register file and wide data path while leaving 2718 pointers at 32 bits for smaller memory footprint. 2719 2720 You will need a recent binutils (2.22 or later) with 2721 elf32_x86_64 support enabled to compile a kernel with this 2722 option set. 2723 2724config COMPAT 2725 def_bool y 2726 depends on IA32_EMULATION || X86_X32 2727 2728if COMPAT 2729config COMPAT_FOR_U64_ALIGNMENT 2730 def_bool y 2731 2732config SYSVIPC_COMPAT 2733 def_bool y 2734 depends on SYSVIPC 2735 2736config KEYS_COMPAT 2737 def_bool y 2738 depends on KEYS 2739endif 2740 2741endmenu 2742 2743 2744config HAVE_ATOMIC_IOMAP 2745 def_bool y 2746 depends on X86_32 2747 2748config X86_DEV_DMA_OPS 2749 bool 2750 depends on X86_64 || STA2X11 2751 2752config X86_DMA_REMAP 2753 bool 2754 depends on STA2X11 2755 2756config PMC_ATOM 2757 def_bool y 2758 depends on PCI 2759 2760source "net/Kconfig" 2761 2762source "drivers/Kconfig" 2763 2764source "drivers/firmware/Kconfig" 2765 2766source "fs/Kconfig" 2767 2768source "arch/x86/Kconfig.debug" 2769 2770source "security/Kconfig" 2771 2772source "crypto/Kconfig" 2773 2774source "arch/x86/kvm/Kconfig" 2775 2776source "lib/Kconfig" 2777