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 # Options that are inherently 32-bit kernel only: 13 select ARCH_WANT_IPC_PARSE_VERSION 14 select CLKSRC_I8253 15 select CLONE_BACKWARDS 16 select HAVE_AOUT 17 select HAVE_GENERIC_DMA_COHERENT 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 21config X86_64 22 def_bool y 23 depends on 64BIT 24 # Options that are inherently 64-bit kernel only: 25 select ARCH_HAS_GIGANTIC_PAGE 26 select ARCH_SUPPORTS_INT128 27 select ARCH_USE_CMPXCHG_LOCKREF 28 select HAVE_ARCH_SOFT_DIRTY 29 select MODULES_USE_ELF_RELA 30 select X86_DEV_DMA_OPS 31 32# 33# Arch settings 34# 35# ( Note that options that are marked 'if X86_64' could in principle be 36# ported to 32-bit as well. ) 37# 38config X86 39 def_bool y 40 # 41 # Note: keep this list sorted alphabetically 42 # 43 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 44 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 45 select ANON_INODES 46 select ARCH_CLOCKSOURCE_DATA 47 select ARCH_DISCARD_MEMBLOCK 48 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 49 select ARCH_HAS_DEBUG_VIRTUAL 50 select ARCH_HAS_DEVMEM_IS_ALLOWED 51 select ARCH_HAS_ELF_RANDOMIZE 52 select ARCH_HAS_FAST_MULTIPLIER 53 select ARCH_HAS_GCOV_PROFILE_ALL 54 select ARCH_HAS_KCOV if X86_64 55 select ARCH_HAS_MMIO_FLUSH 56 select ARCH_HAS_PMEM_API if X86_64 57 select ARCH_HAS_SET_MEMORY 58 select ARCH_HAS_SG_CHAIN 59 select ARCH_HAS_STRICT_KERNEL_RWX 60 select ARCH_HAS_STRICT_MODULE_RWX 61 select ARCH_HAS_UBSAN_SANITIZE_ALL 62 select ARCH_HAVE_NMI_SAFE_CMPXCHG 63 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 64 select ARCH_MIGHT_HAVE_PC_PARPORT 65 select ARCH_MIGHT_HAVE_PC_SERIO 66 select ARCH_SUPPORTS_ATOMIC_RMW 67 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 68 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 69 select ARCH_USE_BUILTIN_BSWAP 70 select ARCH_USE_QUEUED_RWLOCKS 71 select ARCH_USE_QUEUED_SPINLOCKS 72 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 73 select ARCH_WANT_FRAME_POINTERS 74 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 75 select BUILDTIME_EXTABLE_SORT 76 select CLKEVT_I8253 77 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 78 select CLOCKSOURCE_WATCHDOG 79 select DCACHE_WORD_ACCESS 80 select EDAC_ATOMIC_SCRUB 81 select EDAC_SUPPORT 82 select GENERIC_CLOCKEVENTS 83 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 84 select GENERIC_CLOCKEVENTS_MIN_ADJUST 85 select GENERIC_CMOS_UPDATE 86 select GENERIC_CPU_AUTOPROBE 87 select GENERIC_EARLY_IOREMAP 88 select GENERIC_FIND_FIRST_BIT 89 select GENERIC_IOMAP 90 select GENERIC_IRQ_PROBE 91 select GENERIC_IRQ_SHOW 92 select GENERIC_PENDING_IRQ if SMP 93 select GENERIC_SMP_IDLE_THREAD 94 select GENERIC_STRNCPY_FROM_USER 95 select GENERIC_STRNLEN_USER 96 select GENERIC_TIME_VSYSCALL 97 select HAVE_ACPI_APEI if ACPI 98 select HAVE_ACPI_APEI_NMI if ACPI 99 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 100 select HAVE_ARCH_AUDITSYSCALL 101 select HAVE_ARCH_HARDENED_USERCOPY 102 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 103 select HAVE_ARCH_JUMP_LABEL 104 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 105 select HAVE_ARCH_KGDB 106 select HAVE_ARCH_KMEMCHECK 107 select HAVE_ARCH_MMAP_RND_BITS if MMU 108 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 109 select HAVE_ARCH_SECCOMP_FILTER 110 select HAVE_ARCH_TRACEHOOK 111 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 112 select HAVE_ARCH_VMAP_STACK if X86_64 113 select HAVE_ARCH_WITHIN_STACK_FRAMES 114 select HAVE_CC_STACKPROTECTOR 115 select HAVE_CMPXCHG_DOUBLE 116 select HAVE_CMPXCHG_LOCAL 117 select HAVE_CONTEXT_TRACKING if X86_64 118 select HAVE_COPY_THREAD_TLS 119 select HAVE_C_RECORDMCOUNT 120 select HAVE_DEBUG_KMEMLEAK 121 select HAVE_DEBUG_STACKOVERFLOW 122 select HAVE_DMA_API_DEBUG 123 select HAVE_DMA_CONTIGUOUS 124 select HAVE_DYNAMIC_FTRACE 125 select HAVE_DYNAMIC_FTRACE_WITH_REGS 126 select HAVE_EBPF_JIT if X86_64 127 select HAVE_EFFICIENT_UNALIGNED_ACCESS 128 select HAVE_EXIT_THREAD 129 select HAVE_FENTRY if X86_64 130 select HAVE_FTRACE_MCOUNT_RECORD 131 select HAVE_FUNCTION_GRAPH_TRACER 132 select HAVE_FUNCTION_TRACER 133 select HAVE_GCC_PLUGINS 134 select HAVE_HW_BREAKPOINT 135 select HAVE_IDE 136 select HAVE_IOREMAP_PROT 137 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 138 select HAVE_IRQ_TIME_ACCOUNTING 139 select HAVE_KERNEL_BZIP2 140 select HAVE_KERNEL_GZIP 141 select HAVE_KERNEL_LZ4 142 select HAVE_KERNEL_LZMA 143 select HAVE_KERNEL_LZO 144 select HAVE_KERNEL_XZ 145 select HAVE_KPROBES 146 select HAVE_KPROBES_ON_FTRACE 147 select HAVE_KRETPROBES 148 select HAVE_KVM 149 select HAVE_LIVEPATCH if X86_64 150 select HAVE_MEMBLOCK 151 select HAVE_MEMBLOCK_NODE_MAP 152 select HAVE_MIXED_BREAKPOINTS_REGS 153 select HAVE_NMI 154 select HAVE_OPROFILE 155 select HAVE_OPTPROBES 156 select HAVE_PCSPKR_PLATFORM 157 select HAVE_PERF_EVENTS 158 select HAVE_PERF_EVENTS_NMI 159 select HAVE_PERF_REGS 160 select HAVE_PERF_USER_STACK_DUMP 161 select HAVE_REGS_AND_STACK_ACCESS_API 162 select HAVE_STACK_VALIDATION if X86_64 163 select HAVE_SYSCALL_TRACEPOINTS 164 select HAVE_UNSTABLE_SCHED_CLOCK 165 select HAVE_USER_RETURN_NOTIFIER 166 select IRQ_FORCED_THREADING 167 select PERF_EVENTS 168 select RTC_LIB 169 select RTC_MC146818_LIB 170 select SPARSE_IRQ 171 select SRCU 172 select SYSCTL_EXCEPTION_TRACE 173 select THREAD_INFO_IN_TASK 174 select USER_STACKTRACE_SUPPORT 175 select VIRT_TO_BUS 176 select X86_FEATURE_NAMES if PROC_FS 177 178config INSTRUCTION_DECODER 179 def_bool y 180 depends on KPROBES || PERF_EVENTS || UPROBES 181 182config OUTPUT_FORMAT 183 string 184 default "elf32-i386" if X86_32 185 default "elf64-x86-64" if X86_64 186 187config ARCH_DEFCONFIG 188 string 189 default "arch/x86/configs/i386_defconfig" if X86_32 190 default "arch/x86/configs/x86_64_defconfig" if X86_64 191 192config LOCKDEP_SUPPORT 193 def_bool y 194 195config STACKTRACE_SUPPORT 196 def_bool y 197 198config MMU 199 def_bool y 200 201config ARCH_MMAP_RND_BITS_MIN 202 default 28 if 64BIT 203 default 8 204 205config ARCH_MMAP_RND_BITS_MAX 206 default 32 if 64BIT 207 default 16 208 209config ARCH_MMAP_RND_COMPAT_BITS_MIN 210 default 8 211 212config ARCH_MMAP_RND_COMPAT_BITS_MAX 213 default 16 214 215config SBUS 216 bool 217 218config NEED_DMA_MAP_STATE 219 def_bool y 220 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 221 222config NEED_SG_DMA_LENGTH 223 def_bool y 224 225config GENERIC_ISA_DMA 226 def_bool y 227 depends on ISA_DMA_API 228 229config GENERIC_BUG 230 def_bool y 231 depends on BUG 232 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 233 234config GENERIC_BUG_RELATIVE_POINTERS 235 bool 236 237config GENERIC_HWEIGHT 238 def_bool y 239 240config ARCH_MAY_HAVE_PC_FDC 241 def_bool y 242 depends on ISA_DMA_API 243 244config RWSEM_XCHGADD_ALGORITHM 245 def_bool y 246 247config GENERIC_CALIBRATE_DELAY 248 def_bool y 249 250config ARCH_HAS_CPU_RELAX 251 def_bool y 252 253config ARCH_HAS_CACHE_LINE_SIZE 254 def_bool y 255 256config HAVE_SETUP_PER_CPU_AREA 257 def_bool y 258 259config NEED_PER_CPU_EMBED_FIRST_CHUNK 260 def_bool y 261 262config NEED_PER_CPU_PAGE_FIRST_CHUNK 263 def_bool y 264 265config ARCH_HIBERNATION_POSSIBLE 266 def_bool y 267 268config ARCH_SUSPEND_POSSIBLE 269 def_bool y 270 271config ARCH_WANT_HUGE_PMD_SHARE 272 def_bool y 273 274config ARCH_WANT_GENERAL_HUGETLB 275 def_bool y 276 277config ZONE_DMA32 278 def_bool y if X86_64 279 280config AUDIT_ARCH 281 def_bool y if X86_64 282 283config ARCH_SUPPORTS_OPTIMIZED_INLINING 284 def_bool y 285 286config ARCH_SUPPORTS_DEBUG_PAGEALLOC 287 def_bool y 288 289config KASAN_SHADOW_OFFSET 290 hex 291 depends on KASAN 292 default 0xdffffc0000000000 293 294config HAVE_INTEL_TXT 295 def_bool y 296 depends on INTEL_IOMMU && ACPI 297 298config X86_32_SMP 299 def_bool y 300 depends on X86_32 && SMP 301 302config X86_64_SMP 303 def_bool y 304 depends on X86_64 && SMP 305 306config X86_32_LAZY_GS 307 def_bool y 308 depends on X86_32 && !CC_STACKPROTECTOR 309 310config ARCH_SUPPORTS_UPROBES 311 def_bool y 312 313config FIX_EARLYCON_MEM 314 def_bool y 315 316config PGTABLE_LEVELS 317 int 318 default 4 if X86_64 319 default 3 if X86_PAE 320 default 2 321 322source "init/Kconfig" 323source "kernel/Kconfig.freezer" 324 325menu "Processor type and features" 326 327config ZONE_DMA 328 bool "DMA memory allocation support" if EXPERT 329 default y 330 help 331 DMA memory allocation support allows devices with less than 32-bit 332 addressing to allocate within the first 16MB of address space. 333 Disable if no such devices will be used. 334 335 If unsure, say Y. 336 337config SMP 338 bool "Symmetric multi-processing support" 339 ---help--- 340 This enables support for systems with more than one CPU. If you have 341 a system with only one CPU, say N. If you have a system with more 342 than one CPU, say Y. 343 344 If you say N here, the kernel will run on uni- and multiprocessor 345 machines, but will use only one CPU of a multiprocessor machine. If 346 you say Y here, the kernel will run on many, but not all, 347 uniprocessor machines. On a uniprocessor machine, the kernel 348 will run faster if you say N here. 349 350 Note that if you say Y here and choose architecture "586" or 351 "Pentium" under "Processor family", the kernel will not work on 486 352 architectures. Similarly, multiprocessor kernels for the "PPro" 353 architecture may not work on all Pentium based boards. 354 355 People using multiprocessor machines who say Y here should also say 356 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 357 Management" code will be disabled if you say Y here. 358 359 See also <file:Documentation/x86/i386/IO-APIC.txt>, 360 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 361 <http://www.tldp.org/docs.html#howto>. 362 363 If you don't know what to do here, say N. 364 365config X86_FEATURE_NAMES 366 bool "Processor feature human-readable names" if EMBEDDED 367 default y 368 ---help--- 369 This option compiles in a table of x86 feature bits and corresponding 370 names. This is required to support /proc/cpuinfo and a few kernel 371 messages. You can disable this to save space, at the expense of 372 making those few kernel messages show numeric feature bits instead. 373 374 If in doubt, say Y. 375 376config X86_FAST_FEATURE_TESTS 377 bool "Fast CPU feature tests" if EMBEDDED 378 default y 379 ---help--- 380 Some fast-paths in the kernel depend on the capabilities of the CPU. 381 Say Y here for the kernel to patch in the appropriate code at runtime 382 based on the capabilities of the CPU. The infrastructure for patching 383 code at runtime takes up some additional space; space-constrained 384 embedded systems may wish to say N here to produce smaller, slightly 385 slower code. 386 387config X86_X2APIC 388 bool "Support x2apic" 389 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 390 ---help--- 391 This enables x2apic support on CPUs that have this feature. 392 393 This allows 32-bit apic IDs (so it can support very large systems), 394 and accesses the local apic via MSRs not via mmio. 395 396 If you don't know what to do here, say N. 397 398config X86_MPPARSE 399 bool "Enable MPS table" if ACPI || SFI 400 default y 401 depends on X86_LOCAL_APIC 402 ---help--- 403 For old smp systems that do not have proper acpi support. Newer systems 404 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 405 406config X86_BIGSMP 407 bool "Support for big SMP systems with more than 8 CPUs" 408 depends on X86_32 && SMP 409 ---help--- 410 This option is needed for the systems that have more than 8 CPUs 411 412config GOLDFISH 413 def_bool y 414 depends on X86_GOLDFISH 415 416config INTEL_RDT_A 417 bool "Intel Resource Director Technology Allocation support" 418 default n 419 depends on X86 && CPU_SUP_INTEL 420 select KERNFS 421 help 422 Select to enable resource allocation which is a sub-feature of 423 Intel Resource Director Technology(RDT). More information about 424 RDT can be found in the Intel x86 Architecture Software 425 Developer Manual. 426 427 Say N if unsure. 428 429if X86_32 430config X86_EXTENDED_PLATFORM 431 bool "Support for extended (non-PC) x86 platforms" 432 default y 433 ---help--- 434 If you disable this option then the kernel will only support 435 standard PC platforms. (which covers the vast majority of 436 systems out there.) 437 438 If you enable this option then you'll be able to select support 439 for the following (non-PC) 32 bit x86 platforms: 440 Goldfish (Android emulator) 441 AMD Elan 442 RDC R-321x SoC 443 SGI 320/540 (Visual Workstation) 444 STA2X11-based (e.g. Northville) 445 Moorestown MID devices 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 451if X86_64 452config X86_EXTENDED_PLATFORM 453 bool "Support for extended (non-PC) x86 platforms" 454 default y 455 ---help--- 456 If you disable this option then the kernel will only support 457 standard PC platforms. (which covers the vast majority of 458 systems out there.) 459 460 If you enable this option then you'll be able to select support 461 for the following (non-PC) 64 bit x86 platforms: 462 Numascale NumaChip 463 ScaleMP vSMP 464 SGI Ultraviolet 465 466 If you have one of these systems, or if you want to build a 467 generic distribution kernel, say Y here - otherwise say N. 468endif 469# This is an alphabetically sorted list of 64 bit extended platforms 470# Please maintain the alphabetic order if and when there are additions 471config X86_NUMACHIP 472 bool "Numascale NumaChip" 473 depends on X86_64 474 depends on X86_EXTENDED_PLATFORM 475 depends on NUMA 476 depends on SMP 477 depends on X86_X2APIC 478 depends on PCI_MMCONFIG 479 ---help--- 480 Adds support for Numascale NumaChip large-SMP systems. Needed to 481 enable more than ~168 cores. 482 If you don't have one of these, you should say N here. 483 484config X86_VSMP 485 bool "ScaleMP vSMP" 486 select HYPERVISOR_GUEST 487 select PARAVIRT 488 depends on X86_64 && PCI 489 depends on X86_EXTENDED_PLATFORM 490 depends on SMP 491 ---help--- 492 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 493 supposed to run on these EM64T-based machines. Only choose this option 494 if you have one of these machines. 495 496config X86_UV 497 bool "SGI Ultraviolet" 498 depends on X86_64 499 depends on X86_EXTENDED_PLATFORM 500 depends on NUMA 501 depends on EFI 502 depends on X86_X2APIC 503 depends on PCI 504 ---help--- 505 This option is needed in order to support SGI Ultraviolet systems. 506 If you don't have one of these, you should say N here. 507 508# Following is an alphabetically sorted list of 32 bit extended platforms 509# Please maintain the alphabetic order if and when there are additions 510 511config X86_GOLDFISH 512 bool "Goldfish (Virtual Platform)" 513 depends on X86_EXTENDED_PLATFORM 514 ---help--- 515 Enable support for the Goldfish virtual platform used primarily 516 for Android development. Unless you are building for the Android 517 Goldfish emulator say N here. 518 519config X86_INTEL_CE 520 bool "CE4100 TV platform" 521 depends on PCI 522 depends on PCI_GODIRECT 523 depends on X86_IO_APIC 524 depends on X86_32 525 depends on X86_EXTENDED_PLATFORM 526 select X86_REBOOTFIXUPS 527 select OF 528 select OF_EARLY_FLATTREE 529 ---help--- 530 Select for the Intel CE media processor (CE4100) SOC. 531 This option compiles in support for the CE4100 SOC for settop 532 boxes and media devices. 533 534config X86_INTEL_MID 535 bool "Intel MID platform support" 536 depends on X86_EXTENDED_PLATFORM 537 depends on X86_PLATFORM_DEVICES 538 depends on PCI 539 depends on X86_64 || (PCI_GOANY && X86_32) 540 depends on X86_IO_APIC 541 select SFI 542 select I2C 543 select DW_APB_TIMER 544 select APB_TIMER 545 select INTEL_SCU_IPC 546 select MFD_INTEL_MSIC 547 ---help--- 548 Select to build a kernel capable of supporting Intel MID (Mobile 549 Internet Device) platform systems which do not have the PCI legacy 550 interfaces. If you are building for a PC class system say N here. 551 552 Intel MID platforms are based on an Intel processor and chipset which 553 consume less power than most of the x86 derivatives. 554 555config X86_INTEL_QUARK 556 bool "Intel Quark platform support" 557 depends on X86_32 558 depends on X86_EXTENDED_PLATFORM 559 depends on X86_PLATFORM_DEVICES 560 depends on X86_TSC 561 depends on PCI 562 depends on PCI_GOANY 563 depends on X86_IO_APIC 564 select IOSF_MBI 565 select INTEL_IMR 566 select COMMON_CLK 567 ---help--- 568 Select to include support for Quark X1000 SoC. 569 Say Y here if you have a Quark based system such as the Arduino 570 compatible Intel Galileo. 571 572config X86_INTEL_LPSS 573 bool "Intel Low Power Subsystem Support" 574 depends on X86 && ACPI 575 select COMMON_CLK 576 select PINCTRL 577 select IOSF_MBI 578 ---help--- 579 Select to build support for Intel Low Power Subsystem such as 580 found on Intel Lynxpoint PCH. Selecting this option enables 581 things like clock tree (common clock framework) and pincontrol 582 which are needed by the LPSS peripheral drivers. 583 584config X86_AMD_PLATFORM_DEVICE 585 bool "AMD ACPI2Platform devices support" 586 depends on ACPI 587 select COMMON_CLK 588 select PINCTRL 589 ---help--- 590 Select to interpret AMD specific ACPI device to platform device 591 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 592 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 593 implemented under PINCTRL subsystem. 594 595config IOSF_MBI 596 tristate "Intel SoC IOSF Sideband support for SoC platforms" 597 depends on PCI 598 ---help--- 599 This option enables sideband register access support for Intel SoC 600 platforms. On these platforms the IOSF sideband is used in lieu of 601 MSR's for some register accesses, mostly but not limited to thermal 602 and power. Drivers may query the availability of this device to 603 determine if they need the sideband in order to work on these 604 platforms. The sideband is available on the following SoC products. 605 This list is not meant to be exclusive. 606 - BayTrail 607 - Braswell 608 - Quark 609 610 You should say Y if you are running a kernel on one of these SoC's. 611 612config IOSF_MBI_DEBUG 613 bool "Enable IOSF sideband access through debugfs" 614 depends on IOSF_MBI && DEBUG_FS 615 ---help--- 616 Select this option to expose the IOSF sideband access registers (MCR, 617 MDR, MCRX) through debugfs to write and read register information from 618 different units on the SoC. This is most useful for obtaining device 619 state information for debug and analysis. As this is a general access 620 mechanism, users of this option would have specific knowledge of the 621 device they want to access. 622 623 If you don't require the option or are in doubt, say N. 624 625config X86_RDC321X 626 bool "RDC R-321x SoC" 627 depends on X86_32 628 depends on X86_EXTENDED_PLATFORM 629 select M486 630 select X86_REBOOTFIXUPS 631 ---help--- 632 This option is needed for RDC R-321x system-on-chip, also known 633 as R-8610-(G). 634 If you don't have one of these chips, you should say N here. 635 636config X86_32_NON_STANDARD 637 bool "Support non-standard 32-bit SMP architectures" 638 depends on X86_32 && SMP 639 depends on X86_EXTENDED_PLATFORM 640 ---help--- 641 This option compiles in the bigsmp and STA2X11 default 642 subarchitectures. It is intended for a generic binary 643 kernel. If you select them all, kernel will probe it one by 644 one and will fallback to default. 645 646# Alphabetically sorted list of Non standard 32 bit platforms 647 648config X86_SUPPORTS_MEMORY_FAILURE 649 def_bool y 650 # MCE code calls memory_failure(): 651 depends on X86_MCE 652 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 653 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 654 depends on X86_64 || !SPARSEMEM 655 select ARCH_SUPPORTS_MEMORY_FAILURE 656 657config STA2X11 658 bool "STA2X11 Companion Chip Support" 659 depends on X86_32_NON_STANDARD && PCI 660 select X86_DEV_DMA_OPS 661 select X86_DMA_REMAP 662 select SWIOTLB 663 select MFD_STA2X11 664 select GPIOLIB 665 default n 666 ---help--- 667 This adds support for boards based on the STA2X11 IO-Hub, 668 a.k.a. "ConneXt". The chip is used in place of the standard 669 PC chipset, so all "standard" peripherals are missing. If this 670 option is selected the kernel will still be able to boot on 671 standard PC machines. 672 673config X86_32_IRIS 674 tristate "Eurobraille/Iris poweroff module" 675 depends on X86_32 676 ---help--- 677 The Iris machines from EuroBraille do not have APM or ACPI support 678 to shut themselves down properly. A special I/O sequence is 679 needed to do so, which is what this module does at 680 kernel shutdown. 681 682 This is only for Iris machines from EuroBraille. 683 684 If unused, say N. 685 686config SCHED_OMIT_FRAME_POINTER 687 def_bool y 688 prompt "Single-depth WCHAN output" 689 depends on X86 690 ---help--- 691 Calculate simpler /proc/<PID>/wchan values. If this option 692 is disabled then wchan values will recurse back to the 693 caller function. This provides more accurate wchan values, 694 at the expense of slightly more scheduling overhead. 695 696 If in doubt, say "Y". 697 698menuconfig HYPERVISOR_GUEST 699 bool "Linux guest support" 700 ---help--- 701 Say Y here to enable options for running Linux under various hyper- 702 visors. This option enables basic hypervisor detection and platform 703 setup. 704 705 If you say N, all options in this submenu will be skipped and 706 disabled, and Linux guest support won't be built in. 707 708if HYPERVISOR_GUEST 709 710config PARAVIRT 711 bool "Enable paravirtualization code" 712 ---help--- 713 This changes the kernel so it can modify itself when it is run 714 under a hypervisor, potentially improving performance significantly 715 over full virtualization. However, when run without a hypervisor 716 the kernel is theoretically slower and slightly larger. 717 718config PARAVIRT_DEBUG 719 bool "paravirt-ops debugging" 720 depends on PARAVIRT && DEBUG_KERNEL 721 ---help--- 722 Enable to debug paravirt_ops internals. Specifically, BUG if 723 a paravirt_op is missing when it is called. 724 725config PARAVIRT_SPINLOCKS 726 bool "Paravirtualization layer for spinlocks" 727 depends on PARAVIRT && SMP 728 ---help--- 729 Paravirtualized spinlocks allow a pvops backend to replace the 730 spinlock implementation with something virtualization-friendly 731 (for example, block the virtual CPU rather than spinning). 732 733 It has a minimal impact on native kernels and gives a nice performance 734 benefit on paravirtualized KVM / Xen kernels. 735 736 If you are unsure how to answer this question, answer Y. 737 738config QUEUED_LOCK_STAT 739 bool "Paravirt queued spinlock statistics" 740 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 741 ---help--- 742 Enable the collection of statistical data on the slowpath 743 behavior of paravirtualized queued spinlocks and report 744 them on debugfs. 745 746source "arch/x86/xen/Kconfig" 747 748config KVM_GUEST 749 bool "KVM Guest support (including kvmclock)" 750 depends on PARAVIRT 751 select PARAVIRT_CLOCK 752 default y 753 ---help--- 754 This option enables various optimizations for running under the KVM 755 hypervisor. It includes a paravirtualized clock, so that instead 756 of relying on a PIT (or probably other) emulation by the 757 underlying device model, the host provides the guest with 758 timing infrastructure such as time of day, and system time 759 760config KVM_DEBUG_FS 761 bool "Enable debug information for KVM Guests in debugfs" 762 depends on KVM_GUEST && DEBUG_FS 763 default n 764 ---help--- 765 This option enables collection of various statistics for KVM guest. 766 Statistics are displayed in debugfs filesystem. Enabling this option 767 may incur significant overhead. 768 769source "arch/x86/lguest/Kconfig" 770 771config PARAVIRT_TIME_ACCOUNTING 772 bool "Paravirtual steal time accounting" 773 depends on PARAVIRT 774 default n 775 ---help--- 776 Select this option to enable fine granularity task steal time 777 accounting. Time spent executing other tasks in parallel with 778 the current vCPU is discounted from the vCPU power. To account for 779 that, there can be a small performance impact. 780 781 If in doubt, say N here. 782 783config PARAVIRT_CLOCK 784 bool 785 786endif #HYPERVISOR_GUEST 787 788config NO_BOOTMEM 789 def_bool y 790 791source "arch/x86/Kconfig.cpu" 792 793config HPET_TIMER 794 def_bool X86_64 795 prompt "HPET Timer Support" if X86_32 796 ---help--- 797 Use the IA-PC HPET (High Precision Event Timer) to manage 798 time in preference to the PIT and RTC, if a HPET is 799 present. 800 HPET is the next generation timer replacing legacy 8254s. 801 The HPET provides a stable time base on SMP 802 systems, unlike the TSC, but it is more expensive to access, 803 as it is off-chip. The interface used is documented 804 in the HPET spec, revision 1. 805 806 You can safely choose Y here. However, HPET will only be 807 activated if the platform and the BIOS support this feature. 808 Otherwise the 8254 will be used for timing services. 809 810 Choose N to continue using the legacy 8254 timer. 811 812config HPET_EMULATE_RTC 813 def_bool y 814 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 815 816config APB_TIMER 817 def_bool y if X86_INTEL_MID 818 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 819 select DW_APB_TIMER 820 depends on X86_INTEL_MID && SFI 821 help 822 APB timer is the replacement for 8254, HPET on X86 MID platforms. 823 The APBT provides a stable time base on SMP 824 systems, unlike the TSC, but it is more expensive to access, 825 as it is off-chip. APB timers are always running regardless of CPU 826 C states, they are used as per CPU clockevent device when possible. 827 828# Mark as expert because too many people got it wrong. 829# The code disables itself when not needed. 830config DMI 831 default y 832 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 833 bool "Enable DMI scanning" if EXPERT 834 ---help--- 835 Enabled scanning of DMI to identify machine quirks. Say Y 836 here unless you have verified that your setup is not 837 affected by entries in the DMI blacklist. Required by PNP 838 BIOS code. 839 840config GART_IOMMU 841 bool "Old AMD GART IOMMU support" 842 select SWIOTLB 843 depends on X86_64 && PCI && AMD_NB 844 ---help--- 845 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 846 GART based hardware IOMMUs. 847 848 The GART supports full DMA access for devices with 32-bit access 849 limitations, on systems with more than 3 GB. This is usually needed 850 for USB, sound, many IDE/SATA chipsets and some other devices. 851 852 Newer systems typically have a modern AMD IOMMU, supported via 853 the CONFIG_AMD_IOMMU=y config option. 854 855 In normal configurations this driver is only active when needed: 856 there's more than 3 GB of memory and the system contains a 857 32-bit limited device. 858 859 If unsure, say Y. 860 861config CALGARY_IOMMU 862 bool "IBM Calgary IOMMU support" 863 select SWIOTLB 864 depends on X86_64 && PCI 865 ---help--- 866 Support for hardware IOMMUs in IBM's xSeries x366 and x460 867 systems. Needed to run systems with more than 3GB of memory 868 properly with 32-bit PCI devices that do not support DAC 869 (Double Address Cycle). Calgary also supports bus level 870 isolation, where all DMAs pass through the IOMMU. This 871 prevents them from going anywhere except their intended 872 destination. This catches hard-to-find kernel bugs and 873 mis-behaving drivers and devices that do not use the DMA-API 874 properly to set up their DMA buffers. The IOMMU can be 875 turned off at boot time with the iommu=off parameter. 876 Normally the kernel will make the right choice by itself. 877 If unsure, say Y. 878 879config CALGARY_IOMMU_ENABLED_BY_DEFAULT 880 def_bool y 881 prompt "Should Calgary be enabled by default?" 882 depends on CALGARY_IOMMU 883 ---help--- 884 Should Calgary be enabled by default? if you choose 'y', Calgary 885 will be used (if it exists). If you choose 'n', Calgary will not be 886 used even if it exists. If you choose 'n' and would like to use 887 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 888 If unsure, say Y. 889 890# need this always selected by IOMMU for the VIA workaround 891config SWIOTLB 892 def_bool y if X86_64 893 ---help--- 894 Support for software bounce buffers used on x86-64 systems 895 which don't have a hardware IOMMU. Using this PCI devices 896 which can only access 32-bits of memory can be used on systems 897 with more than 3 GB of memory. 898 If unsure, say Y. 899 900config IOMMU_HELPER 901 def_bool y 902 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 903 904config MAXSMP 905 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 906 depends on X86_64 && SMP && DEBUG_KERNEL 907 select CPUMASK_OFFSTACK 908 ---help--- 909 Enable maximum number of CPUS and NUMA Nodes for this architecture. 910 If unsure, say N. 911 912config NR_CPUS 913 int "Maximum number of CPUs" if SMP && !MAXSMP 914 range 2 8 if SMP && X86_32 && !X86_BIGSMP 915 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 916 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 917 default "1" if !SMP 918 default "8192" if MAXSMP 919 default "32" if SMP && X86_BIGSMP 920 default "8" if SMP && X86_32 921 default "64" if SMP 922 ---help--- 923 This allows you to specify the maximum number of CPUs which this 924 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 925 supported value is 8192, otherwise the maximum value is 512. The 926 minimum value which makes sense is 2. 927 928 This is purely to save memory - each supported CPU adds 929 approximately eight kilobytes to the kernel image. 930 931config SCHED_SMT 932 bool "SMT (Hyperthreading) scheduler support" 933 depends on SMP 934 ---help--- 935 SMT scheduler support improves the CPU scheduler's decision making 936 when dealing with Intel Pentium 4 chips with HyperThreading at a 937 cost of slightly increased overhead in some places. If unsure say 938 N here. 939 940config SCHED_MC 941 def_bool y 942 prompt "Multi-core scheduler support" 943 depends on SMP 944 ---help--- 945 Multi-core scheduler support improves the CPU scheduler's decision 946 making when dealing with multi-core CPU chips at a cost of slightly 947 increased overhead in some places. If unsure say N here. 948 949config SCHED_MC_PRIO 950 bool "CPU core priorities scheduler support" 951 depends on SCHED_MC && CPU_SUP_INTEL 952 select X86_INTEL_PSTATE 953 select CPU_FREQ 954 default y 955 ---help--- 956 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 957 core ordering determined at manufacturing time, which allows 958 certain cores to reach higher turbo frequencies (when running 959 single threaded workloads) than others. 960 961 Enabling this kernel feature teaches the scheduler about 962 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 963 scheduler's CPU selection logic accordingly, so that higher 964 overall system performance can be achieved. 965 966 This feature will have no effect on CPUs without this feature. 967 968 If unsure say Y here. 969 970source "kernel/Kconfig.preempt" 971 972config UP_LATE_INIT 973 def_bool y 974 depends on !SMP && X86_LOCAL_APIC 975 976config X86_UP_APIC 977 bool "Local APIC support on uniprocessors" if !PCI_MSI 978 default PCI_MSI 979 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 980 ---help--- 981 A local APIC (Advanced Programmable Interrupt Controller) is an 982 integrated interrupt controller in the CPU. If you have a single-CPU 983 system which has a processor with a local APIC, you can say Y here to 984 enable and use it. If you say Y here even though your machine doesn't 985 have a local APIC, then the kernel will still run with no slowdown at 986 all. The local APIC supports CPU-generated self-interrupts (timer, 987 performance counters), and the NMI watchdog which detects hard 988 lockups. 989 990config X86_UP_IOAPIC 991 bool "IO-APIC support on uniprocessors" 992 depends on X86_UP_APIC 993 ---help--- 994 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 995 SMP-capable replacement for PC-style interrupt controllers. Most 996 SMP systems and many recent uniprocessor systems have one. 997 998 If you have a single-CPU system with an IO-APIC, you can say Y here 999 to use it. If you say Y here even though your machine doesn't have 1000 an IO-APIC, then the kernel will still run with no slowdown at all. 1001 1002config X86_LOCAL_APIC 1003 def_bool y 1004 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1005 select IRQ_DOMAIN_HIERARCHY 1006 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1007 1008config X86_IO_APIC 1009 def_bool y 1010 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1011 1012config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1013 bool "Reroute for broken boot IRQs" 1014 depends on X86_IO_APIC 1015 ---help--- 1016 This option enables a workaround that fixes a source of 1017 spurious interrupts. This is recommended when threaded 1018 interrupt handling is used on systems where the generation of 1019 superfluous "boot interrupts" cannot be disabled. 1020 1021 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1022 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1023 kernel does during interrupt handling). On chipsets where this 1024 boot IRQ generation cannot be disabled, this workaround keeps 1025 the original IRQ line masked so that only the equivalent "boot 1026 IRQ" is delivered to the CPUs. The workaround also tells the 1027 kernel to set up the IRQ handler on the boot IRQ line. In this 1028 way only one interrupt is delivered to the kernel. Otherwise 1029 the spurious second interrupt may cause the kernel to bring 1030 down (vital) interrupt lines. 1031 1032 Only affects "broken" chipsets. Interrupt sharing may be 1033 increased on these systems. 1034 1035config X86_MCE 1036 bool "Machine Check / overheating reporting" 1037 select GENERIC_ALLOCATOR 1038 default y 1039 ---help--- 1040 Machine Check support allows the processor to notify the 1041 kernel if it detects a problem (e.g. overheating, data corruption). 1042 The action the kernel takes depends on the severity of the problem, 1043 ranging from warning messages to halting the machine. 1044 1045config X86_MCE_INTEL 1046 def_bool y 1047 prompt "Intel MCE features" 1048 depends on X86_MCE && X86_LOCAL_APIC 1049 ---help--- 1050 Additional support for intel specific MCE features such as 1051 the thermal monitor. 1052 1053config X86_MCE_AMD 1054 def_bool y 1055 prompt "AMD MCE features" 1056 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1057 ---help--- 1058 Additional support for AMD specific MCE features such as 1059 the DRAM Error Threshold. 1060 1061config X86_ANCIENT_MCE 1062 bool "Support for old Pentium 5 / WinChip machine checks" 1063 depends on X86_32 && X86_MCE 1064 ---help--- 1065 Include support for machine check handling on old Pentium 5 or WinChip 1066 systems. These typically need to be enabled explicitly on the command 1067 line. 1068 1069config X86_MCE_THRESHOLD 1070 depends on X86_MCE_AMD || X86_MCE_INTEL 1071 def_bool y 1072 1073config X86_MCE_INJECT 1074 depends on X86_MCE && X86_LOCAL_APIC 1075 tristate "Machine check injector support" 1076 ---help--- 1077 Provide support for injecting machine checks for testing purposes. 1078 If you don't know what a machine check is and you don't do kernel 1079 QA it is safe to say n. 1080 1081config X86_THERMAL_VECTOR 1082 def_bool y 1083 depends on X86_MCE_INTEL 1084 1085source "arch/x86/events/Kconfig" 1086 1087config X86_LEGACY_VM86 1088 bool "Legacy VM86 support" 1089 default n 1090 depends on X86_32 1091 ---help--- 1092 This option allows user programs to put the CPU into V8086 1093 mode, which is an 80286-era approximation of 16-bit real mode. 1094 1095 Some very old versions of X and/or vbetool require this option 1096 for user mode setting. Similarly, DOSEMU will use it if 1097 available to accelerate real mode DOS programs. However, any 1098 recent version of DOSEMU, X, or vbetool should be fully 1099 functional even without kernel VM86 support, as they will all 1100 fall back to software emulation. Nevertheless, if you are using 1101 a 16-bit DOS program where 16-bit performance matters, vm86 1102 mode might be faster than emulation and you might want to 1103 enable this option. 1104 1105 Note that any app that works on a 64-bit kernel is unlikely to 1106 need this option, as 64-bit kernels don't, and can't, support 1107 V8086 mode. This option is also unrelated to 16-bit protected 1108 mode and is not needed to run most 16-bit programs under Wine. 1109 1110 Enabling this option increases the complexity of the kernel 1111 and slows down exception handling a tiny bit. 1112 1113 If unsure, say N here. 1114 1115config VM86 1116 bool 1117 default X86_LEGACY_VM86 1118 1119config X86_16BIT 1120 bool "Enable support for 16-bit segments" if EXPERT 1121 default y 1122 depends on MODIFY_LDT_SYSCALL 1123 ---help--- 1124 This option is required by programs like Wine to run 16-bit 1125 protected mode legacy code on x86 processors. Disabling 1126 this option saves about 300 bytes on i386, or around 6K text 1127 plus 16K runtime memory on x86-64, 1128 1129config X86_ESPFIX32 1130 def_bool y 1131 depends on X86_16BIT && X86_32 1132 1133config X86_ESPFIX64 1134 def_bool y 1135 depends on X86_16BIT && X86_64 1136 1137config X86_VSYSCALL_EMULATION 1138 bool "Enable vsyscall emulation" if EXPERT 1139 default y 1140 depends on X86_64 1141 ---help--- 1142 This enables emulation of the legacy vsyscall page. Disabling 1143 it is roughly equivalent to booting with vsyscall=none, except 1144 that it will also disable the helpful warning if a program 1145 tries to use a vsyscall. With this option set to N, offending 1146 programs will just segfault, citing addresses of the form 1147 0xffffffffff600?00. 1148 1149 This option is required by many programs built before 2013, and 1150 care should be used even with newer programs if set to N. 1151 1152 Disabling this option saves about 7K of kernel size and 1153 possibly 4K of additional runtime pagetable memory. 1154 1155config TOSHIBA 1156 tristate "Toshiba Laptop support" 1157 depends on X86_32 1158 ---help--- 1159 This adds a driver to safely access the System Management Mode of 1160 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1161 not work on models with a Phoenix BIOS. The System Management Mode 1162 is used to set the BIOS and power saving options on Toshiba portables. 1163 1164 For information on utilities to make use of this driver see the 1165 Toshiba Linux utilities web site at: 1166 <http://www.buzzard.org.uk/toshiba/>. 1167 1168 Say Y if you intend to run this kernel on a Toshiba portable. 1169 Say N otherwise. 1170 1171config I8K 1172 tristate "Dell i8k legacy laptop support" 1173 select HWMON 1174 select SENSORS_DELL_SMM 1175 ---help--- 1176 This option enables legacy /proc/i8k userspace interface in hwmon 1177 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1178 temperature and allows controlling fan speeds of Dell laptops via 1179 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1180 it reports also power and hotkey status. For fan speed control is 1181 needed userspace package i8kutils. 1182 1183 Say Y if you intend to run this kernel on old Dell laptops or want to 1184 use userspace package i8kutils. 1185 Say N otherwise. 1186 1187config X86_REBOOTFIXUPS 1188 bool "Enable X86 board specific fixups for reboot" 1189 depends on X86_32 1190 ---help--- 1191 This enables chipset and/or board specific fixups to be done 1192 in order to get reboot to work correctly. This is only needed on 1193 some combinations of hardware and BIOS. The symptom, for which 1194 this config is intended, is when reboot ends with a stalled/hung 1195 system. 1196 1197 Currently, the only fixup is for the Geode machines using 1198 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1199 1200 Say Y if you want to enable the fixup. Currently, it's safe to 1201 enable this option even if you don't need it. 1202 Say N otherwise. 1203 1204config MICROCODE 1205 bool "CPU microcode loading support" 1206 default y 1207 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1208 select FW_LOADER 1209 ---help--- 1210 If you say Y here, you will be able to update the microcode on 1211 Intel and AMD processors. The Intel support is for the IA32 family, 1212 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1213 AMD support is for families 0x10 and later. You will obviously need 1214 the actual microcode binary data itself which is not shipped with 1215 the Linux kernel. 1216 1217 The preferred method to load microcode from a detached initrd is described 1218 in Documentation/x86/early-microcode.txt. For that you need to enable 1219 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1220 initrd for microcode blobs. 1221 1222 In addition, you can build-in the microcode into the kernel. For that you 1223 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1224 to the CONFIG_EXTRA_FIRMWARE config option. 1225 1226config MICROCODE_INTEL 1227 bool "Intel microcode loading support" 1228 depends on MICROCODE 1229 default MICROCODE 1230 select FW_LOADER 1231 ---help--- 1232 This options enables microcode patch loading support for Intel 1233 processors. 1234 1235 For the current Intel microcode data package go to 1236 <https://downloadcenter.intel.com> and search for 1237 'Linux Processor Microcode Data File'. 1238 1239config MICROCODE_AMD 1240 bool "AMD microcode loading support" 1241 depends on MICROCODE 1242 select FW_LOADER 1243 ---help--- 1244 If you select this option, microcode patch loading support for AMD 1245 processors will be enabled. 1246 1247config MICROCODE_OLD_INTERFACE 1248 def_bool y 1249 depends on MICROCODE 1250 1251config X86_MSR 1252 tristate "/dev/cpu/*/msr - Model-specific register support" 1253 ---help--- 1254 This device gives privileged processes access to the x86 1255 Model-Specific Registers (MSRs). It is a character device with 1256 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1257 MSR accesses are directed to a specific CPU on multi-processor 1258 systems. 1259 1260config X86_CPUID 1261 tristate "/dev/cpu/*/cpuid - CPU information support" 1262 ---help--- 1263 This device gives processes access to the x86 CPUID instruction to 1264 be executed on a specific processor. It is a character device 1265 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1266 /dev/cpu/31/cpuid. 1267 1268choice 1269 prompt "High Memory Support" 1270 default HIGHMEM4G 1271 depends on X86_32 1272 1273config NOHIGHMEM 1274 bool "off" 1275 ---help--- 1276 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1277 However, the address space of 32-bit x86 processors is only 4 1278 Gigabytes large. That means that, if you have a large amount of 1279 physical memory, not all of it can be "permanently mapped" by the 1280 kernel. The physical memory that's not permanently mapped is called 1281 "high memory". 1282 1283 If you are compiling a kernel which will never run on a machine with 1284 more than 1 Gigabyte total physical RAM, answer "off" here (default 1285 choice and suitable for most users). This will result in a "3GB/1GB" 1286 split: 3GB are mapped so that each process sees a 3GB virtual memory 1287 space and the remaining part of the 4GB virtual memory space is used 1288 by the kernel to permanently map as much physical memory as 1289 possible. 1290 1291 If the machine has between 1 and 4 Gigabytes physical RAM, then 1292 answer "4GB" here. 1293 1294 If more than 4 Gigabytes is used then answer "64GB" here. This 1295 selection turns Intel PAE (Physical Address Extension) mode on. 1296 PAE implements 3-level paging on IA32 processors. PAE is fully 1297 supported by Linux, PAE mode is implemented on all recent Intel 1298 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1299 then the kernel will not boot on CPUs that don't support PAE! 1300 1301 The actual amount of total physical memory will either be 1302 auto detected or can be forced by using a kernel command line option 1303 such as "mem=256M". (Try "man bootparam" or see the documentation of 1304 your boot loader (lilo or loadlin) about how to pass options to the 1305 kernel at boot time.) 1306 1307 If unsure, say "off". 1308 1309config HIGHMEM4G 1310 bool "4GB" 1311 ---help--- 1312 Select this if you have a 32-bit processor and between 1 and 4 1313 gigabytes of physical RAM. 1314 1315config HIGHMEM64G 1316 bool "64GB" 1317 depends on !M486 1318 select X86_PAE 1319 ---help--- 1320 Select this if you have a 32-bit processor and more than 4 1321 gigabytes of physical RAM. 1322 1323endchoice 1324 1325choice 1326 prompt "Memory split" if EXPERT 1327 default VMSPLIT_3G 1328 depends on X86_32 1329 ---help--- 1330 Select the desired split between kernel and user memory. 1331 1332 If the address range available to the kernel is less than the 1333 physical memory installed, the remaining memory will be available 1334 as "high memory". Accessing high memory is a little more costly 1335 than low memory, as it needs to be mapped into the kernel first. 1336 Note that increasing the kernel address space limits the range 1337 available to user programs, making the address space there 1338 tighter. Selecting anything other than the default 3G/1G split 1339 will also likely make your kernel incompatible with binary-only 1340 kernel modules. 1341 1342 If you are not absolutely sure what you are doing, leave this 1343 option alone! 1344 1345 config VMSPLIT_3G 1346 bool "3G/1G user/kernel split" 1347 config VMSPLIT_3G_OPT 1348 depends on !X86_PAE 1349 bool "3G/1G user/kernel split (for full 1G low memory)" 1350 config VMSPLIT_2G 1351 bool "2G/2G user/kernel split" 1352 config VMSPLIT_2G_OPT 1353 depends on !X86_PAE 1354 bool "2G/2G user/kernel split (for full 2G low memory)" 1355 config VMSPLIT_1G 1356 bool "1G/3G user/kernel split" 1357endchoice 1358 1359config PAGE_OFFSET 1360 hex 1361 default 0xB0000000 if VMSPLIT_3G_OPT 1362 default 0x80000000 if VMSPLIT_2G 1363 default 0x78000000 if VMSPLIT_2G_OPT 1364 default 0x40000000 if VMSPLIT_1G 1365 default 0xC0000000 1366 depends on X86_32 1367 1368config HIGHMEM 1369 def_bool y 1370 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1371 1372config X86_PAE 1373 bool "PAE (Physical Address Extension) Support" 1374 depends on X86_32 && !HIGHMEM4G 1375 select SWIOTLB 1376 ---help--- 1377 PAE is required for NX support, and furthermore enables 1378 larger swapspace support for non-overcommit purposes. It 1379 has the cost of more pagetable lookup overhead, and also 1380 consumes more pagetable space per process. 1381 1382config ARCH_PHYS_ADDR_T_64BIT 1383 def_bool y 1384 depends on X86_64 || X86_PAE 1385 1386config ARCH_DMA_ADDR_T_64BIT 1387 def_bool y 1388 depends on X86_64 || HIGHMEM64G 1389 1390config X86_DIRECT_GBPAGES 1391 def_bool y 1392 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 1393 ---help--- 1394 Certain kernel features effectively disable kernel 1395 linear 1 GB mappings (even if the CPU otherwise 1396 supports them), so don't confuse the user by printing 1397 that we have them enabled. 1398 1399# Common NUMA Features 1400config NUMA 1401 bool "Numa Memory Allocation and Scheduler Support" 1402 depends on SMP 1403 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1404 default y if X86_BIGSMP 1405 ---help--- 1406 Enable NUMA (Non Uniform Memory Access) support. 1407 1408 The kernel will try to allocate memory used by a CPU on the 1409 local memory controller of the CPU and add some more 1410 NUMA awareness to the kernel. 1411 1412 For 64-bit this is recommended if the system is Intel Core i7 1413 (or later), AMD Opteron, or EM64T NUMA. 1414 1415 For 32-bit this is only needed if you boot a 32-bit 1416 kernel on a 64-bit NUMA platform. 1417 1418 Otherwise, you should say N. 1419 1420config AMD_NUMA 1421 def_bool y 1422 prompt "Old style AMD Opteron NUMA detection" 1423 depends on X86_64 && NUMA && PCI 1424 ---help--- 1425 Enable AMD NUMA node topology detection. You should say Y here if 1426 you have a multi processor AMD system. This uses an old method to 1427 read the NUMA configuration directly from the builtin Northbridge 1428 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1429 which also takes priority if both are compiled in. 1430 1431config X86_64_ACPI_NUMA 1432 def_bool y 1433 prompt "ACPI NUMA detection" 1434 depends on X86_64 && NUMA && ACPI && PCI 1435 select ACPI_NUMA 1436 ---help--- 1437 Enable ACPI SRAT based node topology detection. 1438 1439# Some NUMA nodes have memory ranges that span 1440# other nodes. Even though a pfn is valid and 1441# between a node's start and end pfns, it may not 1442# reside on that node. See memmap_init_zone() 1443# for details. 1444config NODES_SPAN_OTHER_NODES 1445 def_bool y 1446 depends on X86_64_ACPI_NUMA 1447 1448config NUMA_EMU 1449 bool "NUMA emulation" 1450 depends on NUMA 1451 ---help--- 1452 Enable NUMA emulation. A flat machine will be split 1453 into virtual nodes when booted with "numa=fake=N", where N is the 1454 number of nodes. This is only useful for debugging. 1455 1456config NODES_SHIFT 1457 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1458 range 1 10 1459 default "10" if MAXSMP 1460 default "6" if X86_64 1461 default "3" 1462 depends on NEED_MULTIPLE_NODES 1463 ---help--- 1464 Specify the maximum number of NUMA Nodes available on the target 1465 system. Increases memory reserved to accommodate various tables. 1466 1467config ARCH_HAVE_MEMORY_PRESENT 1468 def_bool y 1469 depends on X86_32 && DISCONTIGMEM 1470 1471config NEED_NODE_MEMMAP_SIZE 1472 def_bool y 1473 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1474 1475config ARCH_FLATMEM_ENABLE 1476 def_bool y 1477 depends on X86_32 && !NUMA 1478 1479config ARCH_DISCONTIGMEM_ENABLE 1480 def_bool y 1481 depends on NUMA && X86_32 1482 1483config ARCH_DISCONTIGMEM_DEFAULT 1484 def_bool y 1485 depends on NUMA && X86_32 1486 1487config ARCH_SPARSEMEM_ENABLE 1488 def_bool y 1489 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1490 select SPARSEMEM_STATIC if X86_32 1491 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1492 1493config ARCH_SPARSEMEM_DEFAULT 1494 def_bool y 1495 depends on X86_64 1496 1497config ARCH_SELECT_MEMORY_MODEL 1498 def_bool y 1499 depends on ARCH_SPARSEMEM_ENABLE 1500 1501config ARCH_MEMORY_PROBE 1502 bool "Enable sysfs memory/probe interface" 1503 depends on X86_64 && MEMORY_HOTPLUG 1504 help 1505 This option enables a sysfs memory/probe interface for testing. 1506 See Documentation/memory-hotplug.txt for more information. 1507 If you are unsure how to answer this question, answer N. 1508 1509config ARCH_PROC_KCORE_TEXT 1510 def_bool y 1511 depends on X86_64 && PROC_KCORE 1512 1513config ILLEGAL_POINTER_VALUE 1514 hex 1515 default 0 if X86_32 1516 default 0xdead000000000000 if X86_64 1517 1518source "mm/Kconfig" 1519 1520config X86_PMEM_LEGACY_DEVICE 1521 bool 1522 1523config X86_PMEM_LEGACY 1524 tristate "Support non-standard NVDIMMs and ADR protected memory" 1525 depends on PHYS_ADDR_T_64BIT 1526 depends on BLK_DEV 1527 select X86_PMEM_LEGACY_DEVICE 1528 select LIBNVDIMM 1529 help 1530 Treat memory marked using the non-standard e820 type of 12 as used 1531 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1532 The kernel will offer these regions to the 'pmem' driver so 1533 they can be used for persistent storage. 1534 1535 Say Y if unsure. 1536 1537config HIGHPTE 1538 bool "Allocate 3rd-level pagetables from highmem" 1539 depends on HIGHMEM 1540 ---help--- 1541 The VM uses one page table entry for each page of physical memory. 1542 For systems with a lot of RAM, this can be wasteful of precious 1543 low memory. Setting this option will put user-space page table 1544 entries in high memory. 1545 1546config X86_CHECK_BIOS_CORRUPTION 1547 bool "Check for low memory corruption" 1548 ---help--- 1549 Periodically check for memory corruption in low memory, which 1550 is suspected to be caused by BIOS. Even when enabled in the 1551 configuration, it is disabled at runtime. Enable it by 1552 setting "memory_corruption_check=1" on the kernel command 1553 line. By default it scans the low 64k of memory every 60 1554 seconds; see the memory_corruption_check_size and 1555 memory_corruption_check_period parameters in 1556 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1557 1558 When enabled with the default parameters, this option has 1559 almost no overhead, as it reserves a relatively small amount 1560 of memory and scans it infrequently. It both detects corruption 1561 and prevents it from affecting the running system. 1562 1563 It is, however, intended as a diagnostic tool; if repeatable 1564 BIOS-originated corruption always affects the same memory, 1565 you can use memmap= to prevent the kernel from using that 1566 memory. 1567 1568config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1569 bool "Set the default setting of memory_corruption_check" 1570 depends on X86_CHECK_BIOS_CORRUPTION 1571 default y 1572 ---help--- 1573 Set whether the default state of memory_corruption_check is 1574 on or off. 1575 1576config X86_RESERVE_LOW 1577 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1578 default 64 1579 range 4 640 1580 ---help--- 1581 Specify the amount of low memory to reserve for the BIOS. 1582 1583 The first page contains BIOS data structures that the kernel 1584 must not use, so that page must always be reserved. 1585 1586 By default we reserve the first 64K of physical RAM, as a 1587 number of BIOSes are known to corrupt that memory range 1588 during events such as suspend/resume or monitor cable 1589 insertion, so it must not be used by the kernel. 1590 1591 You can set this to 4 if you are absolutely sure that you 1592 trust the BIOS to get all its memory reservations and usages 1593 right. If you know your BIOS have problems beyond the 1594 default 64K area, you can set this to 640 to avoid using the 1595 entire low memory range. 1596 1597 If you have doubts about the BIOS (e.g. suspend/resume does 1598 not work or there's kernel crashes after certain hardware 1599 hotplug events) then you might want to enable 1600 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1601 typical corruption patterns. 1602 1603 Leave this to the default value of 64 if you are unsure. 1604 1605config MATH_EMULATION 1606 bool 1607 depends on MODIFY_LDT_SYSCALL 1608 prompt "Math emulation" if X86_32 1609 ---help--- 1610 Linux can emulate a math coprocessor (used for floating point 1611 operations) if you don't have one. 486DX and Pentium processors have 1612 a math coprocessor built in, 486SX and 386 do not, unless you added 1613 a 487DX or 387, respectively. (The messages during boot time can 1614 give you some hints here ["man dmesg"].) Everyone needs either a 1615 coprocessor or this emulation. 1616 1617 If you don't have a math coprocessor, you need to say Y here; if you 1618 say Y here even though you have a coprocessor, the coprocessor will 1619 be used nevertheless. (This behavior can be changed with the kernel 1620 command line option "no387", which comes handy if your coprocessor 1621 is broken. Try "man bootparam" or see the documentation of your boot 1622 loader (lilo or loadlin) about how to pass options to the kernel at 1623 boot time.) This means that it is a good idea to say Y here if you 1624 intend to use this kernel on different machines. 1625 1626 More information about the internals of the Linux math coprocessor 1627 emulation can be found in <file:arch/x86/math-emu/README>. 1628 1629 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1630 kernel, it won't hurt. 1631 1632config MTRR 1633 def_bool y 1634 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1635 ---help--- 1636 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1637 the Memory Type Range Registers (MTRRs) may be used to control 1638 processor access to memory ranges. This is most useful if you have 1639 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1640 allows bus write transfers to be combined into a larger transfer 1641 before bursting over the PCI/AGP bus. This can increase performance 1642 of image write operations 2.5 times or more. Saying Y here creates a 1643 /proc/mtrr file which may be used to manipulate your processor's 1644 MTRRs. Typically the X server should use this. 1645 1646 This code has a reasonably generic interface so that similar 1647 control registers on other processors can be easily supported 1648 as well: 1649 1650 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1651 Registers (ARRs) which provide a similar functionality to MTRRs. For 1652 these, the ARRs are used to emulate the MTRRs. 1653 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1654 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1655 write-combining. All of these processors are supported by this code 1656 and it makes sense to say Y here if you have one of them. 1657 1658 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1659 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1660 can lead to all sorts of problems, so it's good to say Y here. 1661 1662 You can safely say Y even if your machine doesn't have MTRRs, you'll 1663 just add about 9 KB to your kernel. 1664 1665 See <file:Documentation/x86/mtrr.txt> for more information. 1666 1667config MTRR_SANITIZER 1668 def_bool y 1669 prompt "MTRR cleanup support" 1670 depends on MTRR 1671 ---help--- 1672 Convert MTRR layout from continuous to discrete, so X drivers can 1673 add writeback entries. 1674 1675 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1676 The largest mtrr entry size for a continuous block can be set with 1677 mtrr_chunk_size. 1678 1679 If unsure, say Y. 1680 1681config MTRR_SANITIZER_ENABLE_DEFAULT 1682 int "MTRR cleanup enable value (0-1)" 1683 range 0 1 1684 default "0" 1685 depends on MTRR_SANITIZER 1686 ---help--- 1687 Enable mtrr cleanup default value 1688 1689config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1690 int "MTRR cleanup spare reg num (0-7)" 1691 range 0 7 1692 default "1" 1693 depends on MTRR_SANITIZER 1694 ---help--- 1695 mtrr cleanup spare entries default, it can be changed via 1696 mtrr_spare_reg_nr=N on the kernel command line. 1697 1698config X86_PAT 1699 def_bool y 1700 prompt "x86 PAT support" if EXPERT 1701 depends on MTRR 1702 ---help--- 1703 Use PAT attributes to setup page level cache control. 1704 1705 PATs are the modern equivalents of MTRRs and are much more 1706 flexible than MTRRs. 1707 1708 Say N here if you see bootup problems (boot crash, boot hang, 1709 spontaneous reboots) or a non-working video driver. 1710 1711 If unsure, say Y. 1712 1713config ARCH_USES_PG_UNCACHED 1714 def_bool y 1715 depends on X86_PAT 1716 1717config ARCH_RANDOM 1718 def_bool y 1719 prompt "x86 architectural random number generator" if EXPERT 1720 ---help--- 1721 Enable the x86 architectural RDRAND instruction 1722 (Intel Bull Mountain technology) to generate random numbers. 1723 If supported, this is a high bandwidth, cryptographically 1724 secure hardware random number generator. 1725 1726config X86_SMAP 1727 def_bool y 1728 prompt "Supervisor Mode Access Prevention" if EXPERT 1729 ---help--- 1730 Supervisor Mode Access Prevention (SMAP) is a security 1731 feature in newer Intel processors. There is a small 1732 performance cost if this enabled and turned on; there is 1733 also a small increase in the kernel size if this is enabled. 1734 1735 If unsure, say Y. 1736 1737config X86_INTEL_MPX 1738 prompt "Intel MPX (Memory Protection Extensions)" 1739 def_bool n 1740 depends on CPU_SUP_INTEL 1741 ---help--- 1742 MPX provides hardware features that can be used in 1743 conjunction with compiler-instrumented code to check 1744 memory references. It is designed to detect buffer 1745 overflow or underflow bugs. 1746 1747 This option enables running applications which are 1748 instrumented or otherwise use MPX. It does not use MPX 1749 itself inside the kernel or to protect the kernel 1750 against bad memory references. 1751 1752 Enabling this option will make the kernel larger: 1753 ~8k of kernel text and 36 bytes of data on a 64-bit 1754 defconfig. It adds a long to the 'mm_struct' which 1755 will increase the kernel memory overhead of each 1756 process and adds some branches to paths used during 1757 exec() and munmap(). 1758 1759 For details, see Documentation/x86/intel_mpx.txt 1760 1761 If unsure, say N. 1762 1763config X86_INTEL_MEMORY_PROTECTION_KEYS 1764 prompt "Intel Memory Protection Keys" 1765 def_bool y 1766 # Note: only available in 64-bit mode 1767 depends on CPU_SUP_INTEL && X86_64 1768 select ARCH_USES_HIGH_VMA_FLAGS 1769 select ARCH_HAS_PKEYS 1770 ---help--- 1771 Memory Protection Keys provides a mechanism for enforcing 1772 page-based protections, but without requiring modification of the 1773 page tables when an application changes protection domains. 1774 1775 For details, see Documentation/x86/protection-keys.txt 1776 1777 If unsure, say y. 1778 1779config EFI 1780 bool "EFI runtime service support" 1781 depends on ACPI 1782 select UCS2_STRING 1783 select EFI_RUNTIME_WRAPPERS 1784 ---help--- 1785 This enables the kernel to use EFI runtime services that are 1786 available (such as the EFI variable services). 1787 1788 This option is only useful on systems that have EFI firmware. 1789 In addition, you should use the latest ELILO loader available 1790 at <http://elilo.sourceforge.net> in order to take advantage 1791 of EFI runtime services. However, even with this option, the 1792 resultant kernel should continue to boot on existing non-EFI 1793 platforms. 1794 1795config EFI_STUB 1796 bool "EFI stub support" 1797 depends on EFI && !X86_USE_3DNOW 1798 select RELOCATABLE 1799 ---help--- 1800 This kernel feature allows a bzImage to be loaded directly 1801 by EFI firmware without the use of a bootloader. 1802 1803 See Documentation/efi-stub.txt for more information. 1804 1805config EFI_MIXED 1806 bool "EFI mixed-mode support" 1807 depends on EFI_STUB && X86_64 1808 ---help--- 1809 Enabling this feature allows a 64-bit kernel to be booted 1810 on a 32-bit firmware, provided that your CPU supports 64-bit 1811 mode. 1812 1813 Note that it is not possible to boot a mixed-mode enabled 1814 kernel via the EFI boot stub - a bootloader that supports 1815 the EFI handover protocol must be used. 1816 1817 If unsure, say N. 1818 1819config SECCOMP 1820 def_bool y 1821 prompt "Enable seccomp to safely compute untrusted bytecode" 1822 ---help--- 1823 This kernel feature is useful for number crunching applications 1824 that may need to compute untrusted bytecode during their 1825 execution. By using pipes or other transports made available to 1826 the process as file descriptors supporting the read/write 1827 syscalls, it's possible to isolate those applications in 1828 their own address space using seccomp. Once seccomp is 1829 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1830 and the task is only allowed to execute a few safe syscalls 1831 defined by each seccomp mode. 1832 1833 If unsure, say Y. Only embedded should say N here. 1834 1835source kernel/Kconfig.hz 1836 1837config KEXEC 1838 bool "kexec system call" 1839 select KEXEC_CORE 1840 ---help--- 1841 kexec is a system call that implements the ability to shutdown your 1842 current kernel, and to start another kernel. It is like a reboot 1843 but it is independent of the system firmware. And like a reboot 1844 you can start any kernel with it, not just Linux. 1845 1846 The name comes from the similarity to the exec system call. 1847 1848 It is an ongoing process to be certain the hardware in a machine 1849 is properly shutdown, so do not be surprised if this code does not 1850 initially work for you. As of this writing the exact hardware 1851 interface is strongly in flux, so no good recommendation can be 1852 made. 1853 1854config KEXEC_FILE 1855 bool "kexec file based system call" 1856 select KEXEC_CORE 1857 select BUILD_BIN2C 1858 depends on X86_64 1859 depends on CRYPTO=y 1860 depends on CRYPTO_SHA256=y 1861 ---help--- 1862 This is new version of kexec system call. This system call is 1863 file based and takes file descriptors as system call argument 1864 for kernel and initramfs as opposed to list of segments as 1865 accepted by previous system call. 1866 1867config KEXEC_VERIFY_SIG 1868 bool "Verify kernel signature during kexec_file_load() syscall" 1869 depends on KEXEC_FILE 1870 ---help--- 1871 This option makes kernel signature verification mandatory for 1872 the kexec_file_load() syscall. 1873 1874 In addition to that option, you need to enable signature 1875 verification for the corresponding kernel image type being 1876 loaded in order for this to work. 1877 1878config KEXEC_BZIMAGE_VERIFY_SIG 1879 bool "Enable bzImage signature verification support" 1880 depends on KEXEC_VERIFY_SIG 1881 depends on SIGNED_PE_FILE_VERIFICATION 1882 select SYSTEM_TRUSTED_KEYRING 1883 ---help--- 1884 Enable bzImage signature verification support. 1885 1886config CRASH_DUMP 1887 bool "kernel crash dumps" 1888 depends on X86_64 || (X86_32 && HIGHMEM) 1889 ---help--- 1890 Generate crash dump after being started by kexec. 1891 This should be normally only set in special crash dump kernels 1892 which are loaded in the main kernel with kexec-tools into 1893 a specially reserved region and then later executed after 1894 a crash by kdump/kexec. The crash dump kernel must be compiled 1895 to a memory address not used by the main kernel or BIOS using 1896 PHYSICAL_START, or it must be built as a relocatable image 1897 (CONFIG_RELOCATABLE=y). 1898 For more details see Documentation/kdump/kdump.txt 1899 1900config KEXEC_JUMP 1901 bool "kexec jump" 1902 depends on KEXEC && HIBERNATION 1903 ---help--- 1904 Jump between original kernel and kexeced kernel and invoke 1905 code in physical address mode via KEXEC 1906 1907config PHYSICAL_START 1908 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1909 default "0x1000000" 1910 ---help--- 1911 This gives the physical address where the kernel is loaded. 1912 1913 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1914 bzImage will decompress itself to above physical address and 1915 run from there. Otherwise, bzImage will run from the address where 1916 it has been loaded by the boot loader and will ignore above physical 1917 address. 1918 1919 In normal kdump cases one does not have to set/change this option 1920 as now bzImage can be compiled as a completely relocatable image 1921 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1922 address. This option is mainly useful for the folks who don't want 1923 to use a bzImage for capturing the crash dump and want to use a 1924 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1925 to be specifically compiled to run from a specific memory area 1926 (normally a reserved region) and this option comes handy. 1927 1928 So if you are using bzImage for capturing the crash dump, 1929 leave the value here unchanged to 0x1000000 and set 1930 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1931 for capturing the crash dump change this value to start of 1932 the reserved region. In other words, it can be set based on 1933 the "X" value as specified in the "crashkernel=YM@XM" 1934 command line boot parameter passed to the panic-ed 1935 kernel. Please take a look at Documentation/kdump/kdump.txt 1936 for more details about crash dumps. 1937 1938 Usage of bzImage for capturing the crash dump is recommended as 1939 one does not have to build two kernels. Same kernel can be used 1940 as production kernel and capture kernel. Above option should have 1941 gone away after relocatable bzImage support is introduced. But it 1942 is present because there are users out there who continue to use 1943 vmlinux for dump capture. This option should go away down the 1944 line. 1945 1946 Don't change this unless you know what you are doing. 1947 1948config RELOCATABLE 1949 bool "Build a relocatable kernel" 1950 default y 1951 ---help--- 1952 This builds a kernel image that retains relocation information 1953 so it can be loaded someplace besides the default 1MB. 1954 The relocations tend to make the kernel binary about 10% larger, 1955 but are discarded at runtime. 1956 1957 One use is for the kexec on panic case where the recovery kernel 1958 must live at a different physical address than the primary 1959 kernel. 1960 1961 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1962 it has been loaded at and the compile time physical address 1963 (CONFIG_PHYSICAL_START) is used as the minimum location. 1964 1965config RANDOMIZE_BASE 1966 bool "Randomize the address of the kernel image (KASLR)" 1967 depends on RELOCATABLE 1968 default n 1969 ---help--- 1970 In support of Kernel Address Space Layout Randomization (KASLR), 1971 this randomizes the physical address at which the kernel image 1972 is decompressed and the virtual address where the kernel 1973 image is mapped, as a security feature that deters exploit 1974 attempts relying on knowledge of the location of kernel 1975 code internals. 1976 1977 On 64-bit, the kernel physical and virtual addresses are 1978 randomized separately. The physical address will be anywhere 1979 between 16MB and the top of physical memory (up to 64TB). The 1980 virtual address will be randomized from 16MB up to 1GB (9 bits 1981 of entropy). Note that this also reduces the memory space 1982 available to kernel modules from 1.5GB to 1GB. 1983 1984 On 32-bit, the kernel physical and virtual addresses are 1985 randomized together. They will be randomized from 16MB up to 1986 512MB (8 bits of entropy). 1987 1988 Entropy is generated using the RDRAND instruction if it is 1989 supported. If RDTSC is supported, its value is mixed into 1990 the entropy pool as well. If neither RDRAND nor RDTSC are 1991 supported, then entropy is read from the i8254 timer. The 1992 usable entropy is limited by the kernel being built using 1993 2GB addressing, and that PHYSICAL_ALIGN must be at a 1994 minimum of 2MB. As a result, only 10 bits of entropy are 1995 theoretically possible, but the implementations are further 1996 limited due to memory layouts. 1997 1998 If unsure, say N. 1999 2000# Relocation on x86 needs some additional build support 2001config X86_NEED_RELOCS 2002 def_bool y 2003 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2004 2005config PHYSICAL_ALIGN 2006 hex "Alignment value to which kernel should be aligned" 2007 default "0x200000" 2008 range 0x2000 0x1000000 if X86_32 2009 range 0x200000 0x1000000 if X86_64 2010 ---help--- 2011 This value puts the alignment restrictions on physical address 2012 where kernel is loaded and run from. Kernel is compiled for an 2013 address which meets above alignment restriction. 2014 2015 If bootloader loads the kernel at a non-aligned address and 2016 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2017 address aligned to above value and run from there. 2018 2019 If bootloader loads the kernel at a non-aligned address and 2020 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2021 load address and decompress itself to the address it has been 2022 compiled for and run from there. The address for which kernel is 2023 compiled already meets above alignment restrictions. Hence the 2024 end result is that kernel runs from a physical address meeting 2025 above alignment restrictions. 2026 2027 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2028 this value must be a multiple of 0x200000. 2029 2030 Don't change this unless you know what you are doing. 2031 2032config RANDOMIZE_MEMORY 2033 bool "Randomize the kernel memory sections" 2034 depends on X86_64 2035 depends on RANDOMIZE_BASE 2036 default RANDOMIZE_BASE 2037 ---help--- 2038 Randomizes the base virtual address of kernel memory sections 2039 (physical memory mapping, vmalloc & vmemmap). This security feature 2040 makes exploits relying on predictable memory locations less reliable. 2041 2042 The order of allocations remains unchanged. Entropy is generated in 2043 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2044 configuration have in average 30,000 different possible virtual 2045 addresses for each memory section. 2046 2047 If unsure, say N. 2048 2049config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2050 hex "Physical memory mapping padding" if EXPERT 2051 depends on RANDOMIZE_MEMORY 2052 default "0xa" if MEMORY_HOTPLUG 2053 default "0x0" 2054 range 0x1 0x40 if MEMORY_HOTPLUG 2055 range 0x0 0x40 2056 ---help--- 2057 Define the padding in terabytes added to the existing physical 2058 memory size during kernel memory randomization. It is useful 2059 for memory hotplug support but reduces the entropy available for 2060 address randomization. 2061 2062 If unsure, leave at the default value. 2063 2064config HOTPLUG_CPU 2065 bool "Support for hot-pluggable CPUs" 2066 depends on SMP 2067 ---help--- 2068 Say Y here to allow turning CPUs off and on. CPUs can be 2069 controlled through /sys/devices/system/cpu. 2070 ( Note: power management support will enable this option 2071 automatically on SMP systems. ) 2072 Say N if you want to disable CPU hotplug. 2073 2074config BOOTPARAM_HOTPLUG_CPU0 2075 bool "Set default setting of cpu0_hotpluggable" 2076 default n 2077 depends on HOTPLUG_CPU 2078 ---help--- 2079 Set whether default state of cpu0_hotpluggable is on or off. 2080 2081 Say Y here to enable CPU0 hotplug by default. If this switch 2082 is turned on, there is no need to give cpu0_hotplug kernel 2083 parameter and the CPU0 hotplug feature is enabled by default. 2084 2085 Please note: there are two known CPU0 dependencies if you want 2086 to enable the CPU0 hotplug feature either by this switch or by 2087 cpu0_hotplug kernel parameter. 2088 2089 First, resume from hibernate or suspend always starts from CPU0. 2090 So hibernate and suspend are prevented if CPU0 is offline. 2091 2092 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2093 offline if any interrupt can not migrate out of CPU0. There may 2094 be other CPU0 dependencies. 2095 2096 Please make sure the dependencies are under your control before 2097 you enable this feature. 2098 2099 Say N if you don't want to enable CPU0 hotplug feature by default. 2100 You still can enable the CPU0 hotplug feature at boot by kernel 2101 parameter cpu0_hotplug. 2102 2103config DEBUG_HOTPLUG_CPU0 2104 def_bool n 2105 prompt "Debug CPU0 hotplug" 2106 depends on HOTPLUG_CPU 2107 ---help--- 2108 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2109 soon as possible and boots up userspace with CPU0 offlined. User 2110 can online CPU0 back after boot time. 2111 2112 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2113 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2114 compilation or giving cpu0_hotplug kernel parameter at boot. 2115 2116 If unsure, say N. 2117 2118config COMPAT_VDSO 2119 def_bool n 2120 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2121 depends on COMPAT_32 2122 ---help--- 2123 Certain buggy versions of glibc will crash if they are 2124 presented with a 32-bit vDSO that is not mapped at the address 2125 indicated in its segment table. 2126 2127 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2128 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2129 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2130 the only released version with the bug, but OpenSUSE 9 2131 contains a buggy "glibc 2.3.2". 2132 2133 The symptom of the bug is that everything crashes on startup, saying: 2134 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2135 2136 Saying Y here changes the default value of the vdso32 boot 2137 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2138 This works around the glibc bug but hurts performance. 2139 2140 If unsure, say N: if you are compiling your own kernel, you 2141 are unlikely to be using a buggy version of glibc. 2142 2143choice 2144 prompt "vsyscall table for legacy applications" 2145 depends on X86_64 2146 default LEGACY_VSYSCALL_EMULATE 2147 help 2148 Legacy user code that does not know how to find the vDSO expects 2149 to be able to issue three syscalls by calling fixed addresses in 2150 kernel space. Since this location is not randomized with ASLR, 2151 it can be used to assist security vulnerability exploitation. 2152 2153 This setting can be changed at boot time via the kernel command 2154 line parameter vsyscall=[native|emulate|none]. 2155 2156 On a system with recent enough glibc (2.14 or newer) and no 2157 static binaries, you can say None without a performance penalty 2158 to improve security. 2159 2160 If unsure, select "Emulate". 2161 2162 config LEGACY_VSYSCALL_NATIVE 2163 bool "Native" 2164 help 2165 Actual executable code is located in the fixed vsyscall 2166 address mapping, implementing time() efficiently. Since 2167 this makes the mapping executable, it can be used during 2168 security vulnerability exploitation (traditionally as 2169 ROP gadgets). This configuration is not recommended. 2170 2171 config LEGACY_VSYSCALL_EMULATE 2172 bool "Emulate" 2173 help 2174 The kernel traps and emulates calls into the fixed 2175 vsyscall address mapping. This makes the mapping 2176 non-executable, but it still contains known contents, 2177 which could be used in certain rare security vulnerability 2178 exploits. This configuration is recommended when userspace 2179 still uses the vsyscall area. 2180 2181 config LEGACY_VSYSCALL_NONE 2182 bool "None" 2183 help 2184 There will be no vsyscall mapping at all. This will 2185 eliminate any risk of ASLR bypass due to the vsyscall 2186 fixed address mapping. Attempts to use the vsyscalls 2187 will be reported to dmesg, so that either old or 2188 malicious userspace programs can be identified. 2189 2190endchoice 2191 2192config CMDLINE_BOOL 2193 bool "Built-in kernel command line" 2194 ---help--- 2195 Allow for specifying boot arguments to the kernel at 2196 build time. On some systems (e.g. embedded ones), it is 2197 necessary or convenient to provide some or all of the 2198 kernel boot arguments with the kernel itself (that is, 2199 to not rely on the boot loader to provide them.) 2200 2201 To compile command line arguments into the kernel, 2202 set this option to 'Y', then fill in the 2203 boot arguments in CONFIG_CMDLINE. 2204 2205 Systems with fully functional boot loaders (i.e. non-embedded) 2206 should leave this option set to 'N'. 2207 2208config CMDLINE 2209 string "Built-in kernel command string" 2210 depends on CMDLINE_BOOL 2211 default "" 2212 ---help--- 2213 Enter arguments here that should be compiled into the kernel 2214 image and used at boot time. If the boot loader provides a 2215 command line at boot time, it is appended to this string to 2216 form the full kernel command line, when the system boots. 2217 2218 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2219 change this behavior. 2220 2221 In most cases, the command line (whether built-in or provided 2222 by the boot loader) should specify the device for the root 2223 file system. 2224 2225config CMDLINE_OVERRIDE 2226 bool "Built-in command line overrides boot loader arguments" 2227 depends on CMDLINE_BOOL 2228 ---help--- 2229 Set this option to 'Y' to have the kernel ignore the boot loader 2230 command line, and use ONLY the built-in command line. 2231 2232 This is used to work around broken boot loaders. This should 2233 be set to 'N' under normal conditions. 2234 2235config MODIFY_LDT_SYSCALL 2236 bool "Enable the LDT (local descriptor table)" if EXPERT 2237 default y 2238 ---help--- 2239 Linux can allow user programs to install a per-process x86 2240 Local Descriptor Table (LDT) using the modify_ldt(2) system 2241 call. This is required to run 16-bit or segmented code such as 2242 DOSEMU or some Wine programs. It is also used by some very old 2243 threading libraries. 2244 2245 Enabling this feature adds a small amount of overhead to 2246 context switches and increases the low-level kernel attack 2247 surface. Disabling it removes the modify_ldt(2) system call. 2248 2249 Saying 'N' here may make sense for embedded or server kernels. 2250 2251source "kernel/livepatch/Kconfig" 2252 2253endmenu 2254 2255config ARCH_ENABLE_MEMORY_HOTPLUG 2256 def_bool y 2257 depends on X86_64 || (X86_32 && HIGHMEM) 2258 2259config ARCH_ENABLE_MEMORY_HOTREMOVE 2260 def_bool y 2261 depends on MEMORY_HOTPLUG 2262 2263config USE_PERCPU_NUMA_NODE_ID 2264 def_bool y 2265 depends on NUMA 2266 2267config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2268 def_bool y 2269 depends on X86_64 || X86_PAE 2270 2271config ARCH_ENABLE_HUGEPAGE_MIGRATION 2272 def_bool y 2273 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2274 2275menu "Power management and ACPI options" 2276 2277config ARCH_HIBERNATION_HEADER 2278 def_bool y 2279 depends on X86_64 && HIBERNATION 2280 2281source "kernel/power/Kconfig" 2282 2283source "drivers/acpi/Kconfig" 2284 2285source "drivers/sfi/Kconfig" 2286 2287config X86_APM_BOOT 2288 def_bool y 2289 depends on APM 2290 2291menuconfig APM 2292 tristate "APM (Advanced Power Management) BIOS support" 2293 depends on X86_32 && PM_SLEEP 2294 ---help--- 2295 APM is a BIOS specification for saving power using several different 2296 techniques. This is mostly useful for battery powered laptops with 2297 APM compliant BIOSes. If you say Y here, the system time will be 2298 reset after a RESUME operation, the /proc/apm device will provide 2299 battery status information, and user-space programs will receive 2300 notification of APM "events" (e.g. battery status change). 2301 2302 If you select "Y" here, you can disable actual use of the APM 2303 BIOS by passing the "apm=off" option to the kernel at boot time. 2304 2305 Note that the APM support is almost completely disabled for 2306 machines with more than one CPU. 2307 2308 In order to use APM, you will need supporting software. For location 2309 and more information, read <file:Documentation/power/apm-acpi.txt> 2310 and the Battery Powered Linux mini-HOWTO, available from 2311 <http://www.tldp.org/docs.html#howto>. 2312 2313 This driver does not spin down disk drives (see the hdparm(8) 2314 manpage ("man 8 hdparm") for that), and it doesn't turn off 2315 VESA-compliant "green" monitors. 2316 2317 This driver does not support the TI 4000M TravelMate and the ACER 2318 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2319 desktop machines also don't have compliant BIOSes, and this driver 2320 may cause those machines to panic during the boot phase. 2321 2322 Generally, if you don't have a battery in your machine, there isn't 2323 much point in using this driver and you should say N. If you get 2324 random kernel OOPSes or reboots that don't seem to be related to 2325 anything, try disabling/enabling this option (or disabling/enabling 2326 APM in your BIOS). 2327 2328 Some other things you should try when experiencing seemingly random, 2329 "weird" problems: 2330 2331 1) make sure that you have enough swap space and that it is 2332 enabled. 2333 2) pass the "no-hlt" option to the kernel 2334 3) switch on floating point emulation in the kernel and pass 2335 the "no387" option to the kernel 2336 4) pass the "floppy=nodma" option to the kernel 2337 5) pass the "mem=4M" option to the kernel (thereby disabling 2338 all but the first 4 MB of RAM) 2339 6) make sure that the CPU is not over clocked. 2340 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2341 8) disable the cache from your BIOS settings 2342 9) install a fan for the video card or exchange video RAM 2343 10) install a better fan for the CPU 2344 11) exchange RAM chips 2345 12) exchange the motherboard. 2346 2347 To compile this driver as a module, choose M here: the 2348 module will be called apm. 2349 2350if APM 2351 2352config APM_IGNORE_USER_SUSPEND 2353 bool "Ignore USER SUSPEND" 2354 ---help--- 2355 This option will ignore USER SUSPEND requests. On machines with a 2356 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2357 series notebooks, it is necessary to say Y because of a BIOS bug. 2358 2359config APM_DO_ENABLE 2360 bool "Enable PM at boot time" 2361 ---help--- 2362 Enable APM features at boot time. From page 36 of the APM BIOS 2363 specification: "When disabled, the APM BIOS does not automatically 2364 power manage devices, enter the Standby State, enter the Suspend 2365 State, or take power saving steps in response to CPU Idle calls." 2366 This driver will make CPU Idle calls when Linux is idle (unless this 2367 feature is turned off -- see "Do CPU IDLE calls", below). This 2368 should always save battery power, but more complicated APM features 2369 will be dependent on your BIOS implementation. You may need to turn 2370 this option off if your computer hangs at boot time when using APM 2371 support, or if it beeps continuously instead of suspending. Turn 2372 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2373 T400CDT. This is off by default since most machines do fine without 2374 this feature. 2375 2376config APM_CPU_IDLE 2377 depends on CPU_IDLE 2378 bool "Make CPU Idle calls when idle" 2379 ---help--- 2380 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2381 On some machines, this can activate improved power savings, such as 2382 a slowed CPU clock rate, when the machine is idle. These idle calls 2383 are made after the idle loop has run for some length of time (e.g., 2384 333 mS). On some machines, this will cause a hang at boot time or 2385 whenever the CPU becomes idle. (On machines with more than one CPU, 2386 this option does nothing.) 2387 2388config APM_DISPLAY_BLANK 2389 bool "Enable console blanking using APM" 2390 ---help--- 2391 Enable console blanking using the APM. Some laptops can use this to 2392 turn off the LCD backlight when the screen blanker of the Linux 2393 virtual console blanks the screen. Note that this is only used by 2394 the virtual console screen blanker, and won't turn off the backlight 2395 when using the X Window system. This also doesn't have anything to 2396 do with your VESA-compliant power-saving monitor. Further, this 2397 option doesn't work for all laptops -- it might not turn off your 2398 backlight at all, or it might print a lot of errors to the console, 2399 especially if you are using gpm. 2400 2401config APM_ALLOW_INTS 2402 bool "Allow interrupts during APM BIOS calls" 2403 ---help--- 2404 Normally we disable external interrupts while we are making calls to 2405 the APM BIOS as a measure to lessen the effects of a badly behaving 2406 BIOS implementation. The BIOS should reenable interrupts if it 2407 needs to. Unfortunately, some BIOSes do not -- especially those in 2408 many of the newer IBM Thinkpads. If you experience hangs when you 2409 suspend, try setting this to Y. Otherwise, say N. 2410 2411endif # APM 2412 2413source "drivers/cpufreq/Kconfig" 2414 2415source "drivers/cpuidle/Kconfig" 2416 2417source "drivers/idle/Kconfig" 2418 2419endmenu 2420 2421 2422menu "Bus options (PCI etc.)" 2423 2424config PCI 2425 bool "PCI support" 2426 default y 2427 ---help--- 2428 Find out whether you have a PCI motherboard. PCI is the name of a 2429 bus system, i.e. the way the CPU talks to the other stuff inside 2430 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2431 VESA. If you have PCI, say Y, otherwise N. 2432 2433choice 2434 prompt "PCI access mode" 2435 depends on X86_32 && PCI 2436 default PCI_GOANY 2437 ---help--- 2438 On PCI systems, the BIOS can be used to detect the PCI devices and 2439 determine their configuration. However, some old PCI motherboards 2440 have BIOS bugs and may crash if this is done. Also, some embedded 2441 PCI-based systems don't have any BIOS at all. Linux can also try to 2442 detect the PCI hardware directly without using the BIOS. 2443 2444 With this option, you can specify how Linux should detect the 2445 PCI devices. If you choose "BIOS", the BIOS will be used, 2446 if you choose "Direct", the BIOS won't be used, and if you 2447 choose "MMConfig", then PCI Express MMCONFIG will be used. 2448 If you choose "Any", the kernel will try MMCONFIG, then the 2449 direct access method and falls back to the BIOS if that doesn't 2450 work. If unsure, go with the default, which is "Any". 2451 2452config PCI_GOBIOS 2453 bool "BIOS" 2454 2455config PCI_GOMMCONFIG 2456 bool "MMConfig" 2457 2458config PCI_GODIRECT 2459 bool "Direct" 2460 2461config PCI_GOOLPC 2462 bool "OLPC XO-1" 2463 depends on OLPC 2464 2465config PCI_GOANY 2466 bool "Any" 2467 2468endchoice 2469 2470config PCI_BIOS 2471 def_bool y 2472 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2473 2474# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2475config PCI_DIRECT 2476 def_bool y 2477 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2478 2479config PCI_MMCONFIG 2480 def_bool y 2481 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2482 2483config PCI_OLPC 2484 def_bool y 2485 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2486 2487config PCI_XEN 2488 def_bool y 2489 depends on PCI && XEN 2490 select SWIOTLB_XEN 2491 2492config PCI_DOMAINS 2493 def_bool y 2494 depends on PCI 2495 2496config PCI_MMCONFIG 2497 bool "Support mmconfig PCI config space access" 2498 depends on X86_64 && PCI && ACPI 2499 2500config PCI_CNB20LE_QUIRK 2501 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2502 depends on PCI 2503 help 2504 Read the PCI windows out of the CNB20LE host bridge. This allows 2505 PCI hotplug to work on systems with the CNB20LE chipset which do 2506 not have ACPI. 2507 2508 There's no public spec for this chipset, and this functionality 2509 is known to be incomplete. 2510 2511 You should say N unless you know you need this. 2512 2513source "drivers/pci/Kconfig" 2514 2515config ISA_BUS 2516 bool "ISA-style bus support on modern systems" if EXPERT 2517 select ISA_BUS_API 2518 help 2519 Enables ISA-style drivers on modern systems. This is necessary to 2520 support PC/104 devices on X86_64 platforms. 2521 2522 If unsure, say N. 2523 2524# x86_64 have no ISA slots, but can have ISA-style DMA. 2525config ISA_DMA_API 2526 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2527 default y 2528 help 2529 Enables ISA-style DMA support for devices requiring such controllers. 2530 If unsure, say Y. 2531 2532if X86_32 2533 2534config ISA 2535 bool "ISA support" 2536 ---help--- 2537 Find out whether you have ISA slots on your motherboard. ISA is the 2538 name of a bus system, i.e. the way the CPU talks to the other stuff 2539 inside your box. Other bus systems are PCI, EISA, MicroChannel 2540 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2541 newer boards don't support it. If you have ISA, say Y, otherwise N. 2542 2543config EISA 2544 bool "EISA support" 2545 depends on ISA 2546 ---help--- 2547 The Extended Industry Standard Architecture (EISA) bus was 2548 developed as an open alternative to the IBM MicroChannel bus. 2549 2550 The EISA bus provided some of the features of the IBM MicroChannel 2551 bus while maintaining backward compatibility with cards made for 2552 the older ISA bus. The EISA bus saw limited use between 1988 and 2553 1995 when it was made obsolete by the PCI bus. 2554 2555 Say Y here if you are building a kernel for an EISA-based machine. 2556 2557 Otherwise, say N. 2558 2559source "drivers/eisa/Kconfig" 2560 2561config SCx200 2562 tristate "NatSemi SCx200 support" 2563 ---help--- 2564 This provides basic support for National Semiconductor's 2565 (now AMD's) Geode processors. The driver probes for the 2566 PCI-IDs of several on-chip devices, so its a good dependency 2567 for other scx200_* drivers. 2568 2569 If compiled as a module, the driver is named scx200. 2570 2571config SCx200HR_TIMER 2572 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2573 depends on SCx200 2574 default y 2575 ---help--- 2576 This driver provides a clocksource built upon the on-chip 2577 27MHz high-resolution timer. Its also a workaround for 2578 NSC Geode SC-1100's buggy TSC, which loses time when the 2579 processor goes idle (as is done by the scheduler). The 2580 other workaround is idle=poll boot option. 2581 2582config OLPC 2583 bool "One Laptop Per Child support" 2584 depends on !X86_PAE 2585 select GPIOLIB 2586 select OF 2587 select OF_PROMTREE 2588 select IRQ_DOMAIN 2589 ---help--- 2590 Add support for detecting the unique features of the OLPC 2591 XO hardware. 2592 2593config OLPC_XO1_PM 2594 bool "OLPC XO-1 Power Management" 2595 depends on OLPC && MFD_CS5535 && PM_SLEEP 2596 select MFD_CORE 2597 ---help--- 2598 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2599 2600config OLPC_XO1_RTC 2601 bool "OLPC XO-1 Real Time Clock" 2602 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2603 ---help--- 2604 Add support for the XO-1 real time clock, which can be used as a 2605 programmable wakeup source. 2606 2607config OLPC_XO1_SCI 2608 bool "OLPC XO-1 SCI extras" 2609 depends on OLPC && OLPC_XO1_PM 2610 depends on INPUT=y 2611 select POWER_SUPPLY 2612 select GPIO_CS5535 2613 select MFD_CORE 2614 ---help--- 2615 Add support for SCI-based features of the OLPC XO-1 laptop: 2616 - EC-driven system wakeups 2617 - Power button 2618 - Ebook switch 2619 - Lid switch 2620 - AC adapter status updates 2621 - Battery status updates 2622 2623config OLPC_XO15_SCI 2624 bool "OLPC XO-1.5 SCI extras" 2625 depends on OLPC && ACPI 2626 select POWER_SUPPLY 2627 ---help--- 2628 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2629 - EC-driven system wakeups 2630 - AC adapter status updates 2631 - Battery status updates 2632 2633config ALIX 2634 bool "PCEngines ALIX System Support (LED setup)" 2635 select GPIOLIB 2636 ---help--- 2637 This option enables system support for the PCEngines ALIX. 2638 At present this just sets up LEDs for GPIO control on 2639 ALIX2/3/6 boards. However, other system specific setup should 2640 get added here. 2641 2642 Note: You must still enable the drivers for GPIO and LED support 2643 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2644 2645 Note: You have to set alix.force=1 for boards with Award BIOS. 2646 2647config NET5501 2648 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2649 select GPIOLIB 2650 ---help--- 2651 This option enables system support for the Soekris Engineering net5501. 2652 2653config GEOS 2654 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2655 select GPIOLIB 2656 depends on DMI 2657 ---help--- 2658 This option enables system support for the Traverse Technologies GEOS. 2659 2660config TS5500 2661 bool "Technologic Systems TS-5500 platform support" 2662 depends on MELAN 2663 select CHECK_SIGNATURE 2664 select NEW_LEDS 2665 select LEDS_CLASS 2666 ---help--- 2667 This option enables system support for the Technologic Systems TS-5500. 2668 2669endif # X86_32 2670 2671config AMD_NB 2672 def_bool y 2673 depends on CPU_SUP_AMD && PCI 2674 2675source "drivers/pcmcia/Kconfig" 2676 2677config RAPIDIO 2678 tristate "RapidIO support" 2679 depends on PCI 2680 default n 2681 help 2682 If enabled this option will include drivers and the core 2683 infrastructure code to support RapidIO interconnect devices. 2684 2685source "drivers/rapidio/Kconfig" 2686 2687config X86_SYSFB 2688 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2689 help 2690 Firmwares often provide initial graphics framebuffers so the BIOS, 2691 bootloader or kernel can show basic video-output during boot for 2692 user-guidance and debugging. Historically, x86 used the VESA BIOS 2693 Extensions and EFI-framebuffers for this, which are mostly limited 2694 to x86. 2695 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2696 framebuffers so the new generic system-framebuffer drivers can be 2697 used on x86. If the framebuffer is not compatible with the generic 2698 modes, it is adverticed as fallback platform framebuffer so legacy 2699 drivers like efifb, vesafb and uvesafb can pick it up. 2700 If this option is not selected, all system framebuffers are always 2701 marked as fallback platform framebuffers as usual. 2702 2703 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2704 not be able to pick up generic system framebuffers if this option 2705 is selected. You are highly encouraged to enable simplefb as 2706 replacement if you select this option. simplefb can correctly deal 2707 with generic system framebuffers. But you should still keep vesafb 2708 and others enabled as fallback if a system framebuffer is 2709 incompatible with simplefb. 2710 2711 If unsure, say Y. 2712 2713endmenu 2714 2715 2716menu "Executable file formats / Emulations" 2717 2718source "fs/Kconfig.binfmt" 2719 2720config IA32_EMULATION 2721 bool "IA32 Emulation" 2722 depends on X86_64 2723 select ARCH_WANT_OLD_COMPAT_IPC 2724 select BINFMT_ELF 2725 select COMPAT_BINFMT_ELF 2726 select COMPAT_OLD_SIGACTION 2727 ---help--- 2728 Include code to run legacy 32-bit programs under a 2729 64-bit kernel. You should likely turn this on, unless you're 2730 100% sure that you don't have any 32-bit programs left. 2731 2732config IA32_AOUT 2733 tristate "IA32 a.out support" 2734 depends on IA32_EMULATION 2735 ---help--- 2736 Support old a.out binaries in the 32bit emulation. 2737 2738config X86_X32 2739 bool "x32 ABI for 64-bit mode" 2740 depends on X86_64 2741 ---help--- 2742 Include code to run binaries for the x32 native 32-bit ABI 2743 for 64-bit processors. An x32 process gets access to the 2744 full 64-bit register file and wide data path while leaving 2745 pointers at 32 bits for smaller memory footprint. 2746 2747 You will need a recent binutils (2.22 or later) with 2748 elf32_x86_64 support enabled to compile a kernel with this 2749 option set. 2750 2751config COMPAT_32 2752 def_bool y 2753 depends on IA32_EMULATION || X86_32 2754 select HAVE_UID16 2755 select OLD_SIGSUSPEND3 2756 2757config COMPAT 2758 def_bool y 2759 depends on IA32_EMULATION || X86_X32 2760 2761if COMPAT 2762config COMPAT_FOR_U64_ALIGNMENT 2763 def_bool y 2764 2765config SYSVIPC_COMPAT 2766 def_bool y 2767 depends on SYSVIPC 2768 2769config KEYS_COMPAT 2770 def_bool y 2771 depends on KEYS 2772endif 2773 2774endmenu 2775 2776 2777config HAVE_ATOMIC_IOMAP 2778 def_bool y 2779 depends on X86_32 2780 2781config X86_DEV_DMA_OPS 2782 bool 2783 depends on X86_64 || STA2X11 2784 2785config X86_DMA_REMAP 2786 bool 2787 depends on STA2X11 2788 2789config PMC_ATOM 2790 def_bool y 2791 depends on PCI 2792 2793source "net/Kconfig" 2794 2795source "drivers/Kconfig" 2796 2797source "drivers/firmware/Kconfig" 2798 2799source "fs/Kconfig" 2800 2801source "arch/x86/Kconfig.debug" 2802 2803source "security/Kconfig" 2804 2805source "crypto/Kconfig" 2806 2807source "arch/x86/kvm/Kconfig" 2808 2809source "lib/Kconfig" 2810