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_DEVMEM_IS_ALLOWED 50 select ARCH_HAS_ELF_RANDOMIZE 51 select ARCH_HAS_FAST_MULTIPLIER 52 select ARCH_HAS_GCOV_PROFILE_ALL 53 select ARCH_HAS_KCOV if X86_64 54 select ARCH_HAS_MMIO_FLUSH 55 select ARCH_HAS_PMEM_API if X86_64 56 select ARCH_HAS_SG_CHAIN 57 select ARCH_HAS_UBSAN_SANITIZE_ALL 58 select ARCH_HAVE_NMI_SAFE_CMPXCHG 59 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 60 select ARCH_MIGHT_HAVE_PC_PARPORT 61 select ARCH_MIGHT_HAVE_PC_SERIO 62 select ARCH_SUPPORTS_ATOMIC_RMW 63 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 64 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 65 select ARCH_USE_BUILTIN_BSWAP 66 select ARCH_USE_QUEUED_RWLOCKS 67 select ARCH_USE_QUEUED_SPINLOCKS 68 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 69 select ARCH_WANT_FRAME_POINTERS 70 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 71 select BUILDTIME_EXTABLE_SORT 72 select CLKEVT_I8253 73 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 74 select CLOCKSOURCE_WATCHDOG 75 select DCACHE_WORD_ACCESS 76 select EDAC_ATOMIC_SCRUB 77 select EDAC_SUPPORT 78 select GENERIC_CLOCKEVENTS 79 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 80 select GENERIC_CLOCKEVENTS_MIN_ADJUST 81 select GENERIC_CMOS_UPDATE 82 select GENERIC_CPU_AUTOPROBE 83 select GENERIC_EARLY_IOREMAP 84 select GENERIC_FIND_FIRST_BIT 85 select GENERIC_IOMAP 86 select GENERIC_IRQ_PROBE 87 select GENERIC_IRQ_SHOW 88 select GENERIC_PENDING_IRQ if SMP 89 select GENERIC_SMP_IDLE_THREAD 90 select GENERIC_STRNCPY_FROM_USER 91 select GENERIC_STRNLEN_USER 92 select GENERIC_TIME_VSYSCALL 93 select HAVE_ACPI_APEI if ACPI 94 select HAVE_ACPI_APEI_NMI if ACPI 95 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 96 select HAVE_ARCH_AUDITSYSCALL 97 select HAVE_ARCH_HARDENED_USERCOPY 98 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 99 select HAVE_ARCH_JUMP_LABEL 100 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 101 select HAVE_ARCH_KGDB 102 select HAVE_ARCH_KMEMCHECK 103 select HAVE_ARCH_MMAP_RND_BITS if MMU 104 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 105 select HAVE_ARCH_SECCOMP_FILTER 106 select HAVE_ARCH_TRACEHOOK 107 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 108 select HAVE_ARCH_VMAP_STACK if X86_64 109 select HAVE_ARCH_WITHIN_STACK_FRAMES 110 select HAVE_CC_STACKPROTECTOR 111 select HAVE_CMPXCHG_DOUBLE 112 select HAVE_CMPXCHG_LOCAL 113 select HAVE_CONTEXT_TRACKING if X86_64 114 select HAVE_COPY_THREAD_TLS 115 select HAVE_C_RECORDMCOUNT 116 select HAVE_DEBUG_KMEMLEAK 117 select HAVE_DEBUG_STACKOVERFLOW 118 select HAVE_DMA_API_DEBUG 119 select HAVE_DMA_CONTIGUOUS 120 select HAVE_DYNAMIC_FTRACE 121 select HAVE_DYNAMIC_FTRACE_WITH_REGS 122 select HAVE_EBPF_JIT if X86_64 123 select HAVE_EFFICIENT_UNALIGNED_ACCESS 124 select HAVE_EXIT_THREAD 125 select HAVE_FENTRY if X86_64 126 select HAVE_FTRACE_MCOUNT_RECORD 127 select HAVE_FUNCTION_GRAPH_TRACER 128 select HAVE_FUNCTION_TRACER 129 select HAVE_GCC_PLUGINS 130 select HAVE_HW_BREAKPOINT 131 select HAVE_IDE 132 select HAVE_IOREMAP_PROT 133 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 134 select HAVE_IRQ_TIME_ACCOUNTING 135 select HAVE_KERNEL_BZIP2 136 select HAVE_KERNEL_GZIP 137 select HAVE_KERNEL_LZ4 138 select HAVE_KERNEL_LZMA 139 select HAVE_KERNEL_LZO 140 select HAVE_KERNEL_XZ 141 select HAVE_KPROBES 142 select HAVE_KPROBES_ON_FTRACE 143 select HAVE_KRETPROBES 144 select HAVE_KVM 145 select HAVE_LIVEPATCH if X86_64 146 select HAVE_MEMBLOCK 147 select HAVE_MEMBLOCK_NODE_MAP 148 select HAVE_MIXED_BREAKPOINTS_REGS 149 select HAVE_NMI 150 select HAVE_OPROFILE 151 select HAVE_OPTPROBES 152 select HAVE_PCSPKR_PLATFORM 153 select HAVE_PERF_EVENTS 154 select HAVE_PERF_EVENTS_NMI 155 select HAVE_PERF_REGS 156 select HAVE_PERF_USER_STACK_DUMP 157 select HAVE_REGS_AND_STACK_ACCESS_API 158 select HAVE_STACK_VALIDATION if X86_64 159 select HAVE_SYSCALL_TRACEPOINTS 160 select HAVE_UNSTABLE_SCHED_CLOCK 161 select HAVE_USER_RETURN_NOTIFIER 162 select IRQ_FORCED_THREADING 163 select PERF_EVENTS 164 select RTC_LIB 165 select RTC_MC146818_LIB 166 select SPARSE_IRQ 167 select SRCU 168 select SYSCTL_EXCEPTION_TRACE 169 select THREAD_INFO_IN_TASK 170 select USER_STACKTRACE_SUPPORT 171 select VIRT_TO_BUS 172 select X86_FEATURE_NAMES if PROC_FS 173 174config INSTRUCTION_DECODER 175 def_bool y 176 depends on KPROBES || PERF_EVENTS || UPROBES 177 178config OUTPUT_FORMAT 179 string 180 default "elf32-i386" if X86_32 181 default "elf64-x86-64" if X86_64 182 183config ARCH_DEFCONFIG 184 string 185 default "arch/x86/configs/i386_defconfig" if X86_32 186 default "arch/x86/configs/x86_64_defconfig" if X86_64 187 188config LOCKDEP_SUPPORT 189 def_bool y 190 191config STACKTRACE_SUPPORT 192 def_bool y 193 194config MMU 195 def_bool y 196 197config ARCH_MMAP_RND_BITS_MIN 198 default 28 if 64BIT 199 default 8 200 201config ARCH_MMAP_RND_BITS_MAX 202 default 32 if 64BIT 203 default 16 204 205config ARCH_MMAP_RND_COMPAT_BITS_MIN 206 default 8 207 208config ARCH_MMAP_RND_COMPAT_BITS_MAX 209 default 16 210 211config SBUS 212 bool 213 214config NEED_DMA_MAP_STATE 215 def_bool y 216 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 217 218config NEED_SG_DMA_LENGTH 219 def_bool y 220 221config GENERIC_ISA_DMA 222 def_bool y 223 depends on ISA_DMA_API 224 225config GENERIC_BUG 226 def_bool y 227 depends on BUG 228 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 229 230config GENERIC_BUG_RELATIVE_POINTERS 231 bool 232 233config GENERIC_HWEIGHT 234 def_bool y 235 236config ARCH_MAY_HAVE_PC_FDC 237 def_bool y 238 depends on ISA_DMA_API 239 240config RWSEM_XCHGADD_ALGORITHM 241 def_bool y 242 243config GENERIC_CALIBRATE_DELAY 244 def_bool y 245 246config ARCH_HAS_CPU_RELAX 247 def_bool y 248 249config ARCH_HAS_CACHE_LINE_SIZE 250 def_bool y 251 252config HAVE_SETUP_PER_CPU_AREA 253 def_bool y 254 255config NEED_PER_CPU_EMBED_FIRST_CHUNK 256 def_bool y 257 258config NEED_PER_CPU_PAGE_FIRST_CHUNK 259 def_bool y 260 261config ARCH_HIBERNATION_POSSIBLE 262 def_bool y 263 264config ARCH_SUSPEND_POSSIBLE 265 def_bool y 266 267config ARCH_WANT_HUGE_PMD_SHARE 268 def_bool y 269 270config ARCH_WANT_GENERAL_HUGETLB 271 def_bool y 272 273config ZONE_DMA32 274 def_bool y if X86_64 275 276config AUDIT_ARCH 277 def_bool y if X86_64 278 279config ARCH_SUPPORTS_OPTIMIZED_INLINING 280 def_bool y 281 282config ARCH_SUPPORTS_DEBUG_PAGEALLOC 283 def_bool y 284 285config KASAN_SHADOW_OFFSET 286 hex 287 depends on KASAN 288 default 0xdffffc0000000000 289 290config HAVE_INTEL_TXT 291 def_bool y 292 depends on INTEL_IOMMU && ACPI 293 294config X86_32_SMP 295 def_bool y 296 depends on X86_32 && SMP 297 298config X86_64_SMP 299 def_bool y 300 depends on X86_64 && SMP 301 302config X86_32_LAZY_GS 303 def_bool y 304 depends on X86_32 && !CC_STACKPROTECTOR 305 306config ARCH_SUPPORTS_UPROBES 307 def_bool y 308 309config FIX_EARLYCON_MEM 310 def_bool y 311 312config DEBUG_RODATA 313 def_bool y 314 315config PGTABLE_LEVELS 316 int 317 default 4 if X86_64 318 default 3 if X86_PAE 319 default 2 320 321source "init/Kconfig" 322source "kernel/Kconfig.freezer" 323 324menu "Processor type and features" 325 326config ZONE_DMA 327 bool "DMA memory allocation support" if EXPERT 328 default y 329 help 330 DMA memory allocation support allows devices with less than 32-bit 331 addressing to allocate within the first 16MB of address space. 332 Disable if no such devices will be used. 333 334 If unsure, say Y. 335 336config SMP 337 bool "Symmetric multi-processing support" 338 ---help--- 339 This enables support for systems with more than one CPU. If you have 340 a system with only one CPU, say N. If you have a system with more 341 than one CPU, say Y. 342 343 If you say N here, the kernel will run on uni- and multiprocessor 344 machines, but will use only one CPU of a multiprocessor machine. If 345 you say Y here, the kernel will run on many, but not all, 346 uniprocessor machines. On a uniprocessor machine, the kernel 347 will run faster if you say N here. 348 349 Note that if you say Y here and choose architecture "586" or 350 "Pentium" under "Processor family", the kernel will not work on 486 351 architectures. Similarly, multiprocessor kernels for the "PPro" 352 architecture may not work on all Pentium based boards. 353 354 People using multiprocessor machines who say Y here should also say 355 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 356 Management" code will be disabled if you say Y here. 357 358 See also <file:Documentation/x86/i386/IO-APIC.txt>, 359 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 360 <http://www.tldp.org/docs.html#howto>. 361 362 If you don't know what to do here, say N. 363 364config X86_FEATURE_NAMES 365 bool "Processor feature human-readable names" if EMBEDDED 366 default y 367 ---help--- 368 This option compiles in a table of x86 feature bits and corresponding 369 names. This is required to support /proc/cpuinfo and a few kernel 370 messages. You can disable this to save space, at the expense of 371 making those few kernel messages show numeric feature bits instead. 372 373 If in doubt, say Y. 374 375config X86_FAST_FEATURE_TESTS 376 bool "Fast CPU feature tests" if EMBEDDED 377 default y 378 ---help--- 379 Some fast-paths in the kernel depend on the capabilities of the CPU. 380 Say Y here for the kernel to patch in the appropriate code at runtime 381 based on the capabilities of the CPU. The infrastructure for patching 382 code at runtime takes up some additional space; space-constrained 383 embedded systems may wish to say N here to produce smaller, slightly 384 slower code. 385 386config X86_X2APIC 387 bool "Support x2apic" 388 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 389 ---help--- 390 This enables x2apic support on CPUs that have this feature. 391 392 This allows 32-bit apic IDs (so it can support very large systems), 393 and accesses the local apic via MSRs not via mmio. 394 395 If you don't know what to do here, say N. 396 397config X86_MPPARSE 398 bool "Enable MPS table" if ACPI || SFI 399 default y 400 depends on X86_LOCAL_APIC 401 ---help--- 402 For old smp systems that do not have proper acpi support. Newer systems 403 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 404 405config X86_BIGSMP 406 bool "Support for big SMP systems with more than 8 CPUs" 407 depends on X86_32 && SMP 408 ---help--- 409 This option is needed for the systems that have more than 8 CPUs 410 411config GOLDFISH 412 def_bool y 413 depends on X86_GOLDFISH 414 415config INTEL_RDT_A 416 bool "Intel Resource Director Technology Allocation support" 417 default n 418 depends on X86 && CPU_SUP_INTEL 419 select KERNFS 420 help 421 Select to enable resource allocation which is a sub-feature of 422 Intel Resource Director Technology(RDT). More information about 423 RDT can be found in the Intel x86 Architecture Software 424 Developer Manual. 425 426 Say N if unsure. 427 428if X86_32 429config X86_EXTENDED_PLATFORM 430 bool "Support for extended (non-PC) x86 platforms" 431 default y 432 ---help--- 433 If you disable this option then the kernel will only support 434 standard PC platforms. (which covers the vast majority of 435 systems out there.) 436 437 If you enable this option then you'll be able to select support 438 for the following (non-PC) 32 bit x86 platforms: 439 Goldfish (Android emulator) 440 AMD Elan 441 RDC R-321x SoC 442 SGI 320/540 (Visual Workstation) 443 STA2X11-based (e.g. Northville) 444 Moorestown MID devices 445 446 If you have one of these systems, or if you want to build a 447 generic distribution kernel, say Y here - otherwise say N. 448endif 449 450if X86_64 451config X86_EXTENDED_PLATFORM 452 bool "Support for extended (non-PC) x86 platforms" 453 default y 454 ---help--- 455 If you disable this option then the kernel will only support 456 standard PC platforms. (which covers the vast majority of 457 systems out there.) 458 459 If you enable this option then you'll be able to select support 460 for the following (non-PC) 64 bit x86 platforms: 461 Numascale NumaChip 462 ScaleMP vSMP 463 SGI Ultraviolet 464 465 If you have one of these systems, or if you want to build a 466 generic distribution kernel, say Y here - otherwise say N. 467endif 468# This is an alphabetically sorted list of 64 bit extended platforms 469# Please maintain the alphabetic order if and when there are additions 470config X86_NUMACHIP 471 bool "Numascale NumaChip" 472 depends on X86_64 473 depends on X86_EXTENDED_PLATFORM 474 depends on NUMA 475 depends on SMP 476 depends on X86_X2APIC 477 depends on PCI_MMCONFIG 478 ---help--- 479 Adds support for Numascale NumaChip large-SMP systems. Needed to 480 enable more than ~168 cores. 481 If you don't have one of these, you should say N here. 482 483config X86_VSMP 484 bool "ScaleMP vSMP" 485 select HYPERVISOR_GUEST 486 select PARAVIRT 487 depends on X86_64 && PCI 488 depends on X86_EXTENDED_PLATFORM 489 depends on SMP 490 ---help--- 491 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 492 supposed to run on these EM64T-based machines. Only choose this option 493 if you have one of these machines. 494 495config X86_UV 496 bool "SGI Ultraviolet" 497 depends on X86_64 498 depends on X86_EXTENDED_PLATFORM 499 depends on NUMA 500 depends on EFI 501 depends on X86_X2APIC 502 depends on PCI 503 ---help--- 504 This option is needed in order to support SGI Ultraviolet systems. 505 If you don't have one of these, you should say N here. 506 507# Following is an alphabetically sorted list of 32 bit extended platforms 508# Please maintain the alphabetic order if and when there are additions 509 510config X86_GOLDFISH 511 bool "Goldfish (Virtual Platform)" 512 depends on X86_EXTENDED_PLATFORM 513 ---help--- 514 Enable support for the Goldfish virtual platform used primarily 515 for Android development. Unless you are building for the Android 516 Goldfish emulator say N here. 517 518config X86_INTEL_CE 519 bool "CE4100 TV platform" 520 depends on PCI 521 depends on PCI_GODIRECT 522 depends on X86_IO_APIC 523 depends on X86_32 524 depends on X86_EXTENDED_PLATFORM 525 select X86_REBOOTFIXUPS 526 select OF 527 select OF_EARLY_FLATTREE 528 ---help--- 529 Select for the Intel CE media processor (CE4100) SOC. 530 This option compiles in support for the CE4100 SOC for settop 531 boxes and media devices. 532 533config X86_INTEL_MID 534 bool "Intel MID platform support" 535 depends on X86_EXTENDED_PLATFORM 536 depends on X86_PLATFORM_DEVICES 537 depends on PCI 538 depends on X86_64 || (PCI_GOANY && X86_32) 539 depends on X86_IO_APIC 540 select SFI 541 select I2C 542 select DW_APB_TIMER 543 select APB_TIMER 544 select INTEL_SCU_IPC 545 select MFD_INTEL_MSIC 546 ---help--- 547 Select to build a kernel capable of supporting Intel MID (Mobile 548 Internet Device) platform systems which do not have the PCI legacy 549 interfaces. If you are building for a PC class system say N here. 550 551 Intel MID platforms are based on an Intel processor and chipset which 552 consume less power than most of the x86 derivatives. 553 554config X86_INTEL_QUARK 555 bool "Intel Quark platform support" 556 depends on X86_32 557 depends on X86_EXTENDED_PLATFORM 558 depends on X86_PLATFORM_DEVICES 559 depends on X86_TSC 560 depends on PCI 561 depends on PCI_GOANY 562 depends on X86_IO_APIC 563 select IOSF_MBI 564 select INTEL_IMR 565 select COMMON_CLK 566 ---help--- 567 Select to include support for Quark X1000 SoC. 568 Say Y here if you have a Quark based system such as the Arduino 569 compatible Intel Galileo. 570 571config X86_INTEL_LPSS 572 bool "Intel Low Power Subsystem Support" 573 depends on X86 && ACPI 574 select COMMON_CLK 575 select PINCTRL 576 select IOSF_MBI 577 ---help--- 578 Select to build support for Intel Low Power Subsystem such as 579 found on Intel Lynxpoint PCH. Selecting this option enables 580 things like clock tree (common clock framework) and pincontrol 581 which are needed by the LPSS peripheral drivers. 582 583config X86_AMD_PLATFORM_DEVICE 584 bool "AMD ACPI2Platform devices support" 585 depends on ACPI 586 select COMMON_CLK 587 select PINCTRL 588 ---help--- 589 Select to interpret AMD specific ACPI device to platform device 590 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 591 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 592 implemented under PINCTRL subsystem. 593 594config IOSF_MBI 595 tristate "Intel SoC IOSF Sideband support for SoC platforms" 596 depends on PCI 597 ---help--- 598 This option enables sideband register access support for Intel SoC 599 platforms. On these platforms the IOSF sideband is used in lieu of 600 MSR's for some register accesses, mostly but not limited to thermal 601 and power. Drivers may query the availability of this device to 602 determine if they need the sideband in order to work on these 603 platforms. The sideband is available on the following SoC products. 604 This list is not meant to be exclusive. 605 - BayTrail 606 - Braswell 607 - Quark 608 609 You should say Y if you are running a kernel on one of these SoC's. 610 611config IOSF_MBI_DEBUG 612 bool "Enable IOSF sideband access through debugfs" 613 depends on IOSF_MBI && DEBUG_FS 614 ---help--- 615 Select this option to expose the IOSF sideband access registers (MCR, 616 MDR, MCRX) through debugfs to write and read register information from 617 different units on the SoC. This is most useful for obtaining device 618 state information for debug and analysis. As this is a general access 619 mechanism, users of this option would have specific knowledge of the 620 device they want to access. 621 622 If you don't require the option or are in doubt, say N. 623 624config X86_RDC321X 625 bool "RDC R-321x SoC" 626 depends on X86_32 627 depends on X86_EXTENDED_PLATFORM 628 select M486 629 select X86_REBOOTFIXUPS 630 ---help--- 631 This option is needed for RDC R-321x system-on-chip, also known 632 as R-8610-(G). 633 If you don't have one of these chips, you should say N here. 634 635config X86_32_NON_STANDARD 636 bool "Support non-standard 32-bit SMP architectures" 637 depends on X86_32 && SMP 638 depends on X86_EXTENDED_PLATFORM 639 ---help--- 640 This option compiles in the bigsmp and STA2X11 default 641 subarchitectures. It is intended for a generic binary 642 kernel. If you select them all, kernel will probe it one by 643 one and will fallback to default. 644 645# Alphabetically sorted list of Non standard 32 bit platforms 646 647config X86_SUPPORTS_MEMORY_FAILURE 648 def_bool y 649 # MCE code calls memory_failure(): 650 depends on X86_MCE 651 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 652 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 653 depends on X86_64 || !SPARSEMEM 654 select ARCH_SUPPORTS_MEMORY_FAILURE 655 656config STA2X11 657 bool "STA2X11 Companion Chip Support" 658 depends on X86_32_NON_STANDARD && PCI 659 select X86_DEV_DMA_OPS 660 select X86_DMA_REMAP 661 select SWIOTLB 662 select MFD_STA2X11 663 select GPIOLIB 664 default n 665 ---help--- 666 This adds support for boards based on the STA2X11 IO-Hub, 667 a.k.a. "ConneXt". The chip is used in place of the standard 668 PC chipset, so all "standard" peripherals are missing. If this 669 option is selected the kernel will still be able to boot on 670 standard PC machines. 671 672config X86_32_IRIS 673 tristate "Eurobraille/Iris poweroff module" 674 depends on X86_32 675 ---help--- 676 The Iris machines from EuroBraille do not have APM or ACPI support 677 to shut themselves down properly. A special I/O sequence is 678 needed to do so, which is what this module does at 679 kernel shutdown. 680 681 This is only for Iris machines from EuroBraille. 682 683 If unused, say N. 684 685config SCHED_OMIT_FRAME_POINTER 686 def_bool y 687 prompt "Single-depth WCHAN output" 688 depends on X86 689 ---help--- 690 Calculate simpler /proc/<PID>/wchan values. If this option 691 is disabled then wchan values will recurse back to the 692 caller function. This provides more accurate wchan values, 693 at the expense of slightly more scheduling overhead. 694 695 If in doubt, say "Y". 696 697menuconfig HYPERVISOR_GUEST 698 bool "Linux guest support" 699 ---help--- 700 Say Y here to enable options for running Linux under various hyper- 701 visors. This option enables basic hypervisor detection and platform 702 setup. 703 704 If you say N, all options in this submenu will be skipped and 705 disabled, and Linux guest support won't be built in. 706 707if HYPERVISOR_GUEST 708 709config PARAVIRT 710 bool "Enable paravirtualization code" 711 ---help--- 712 This changes the kernel so it can modify itself when it is run 713 under a hypervisor, potentially improving performance significantly 714 over full virtualization. However, when run without a hypervisor 715 the kernel is theoretically slower and slightly larger. 716 717config PARAVIRT_DEBUG 718 bool "paravirt-ops debugging" 719 depends on PARAVIRT && DEBUG_KERNEL 720 ---help--- 721 Enable to debug paravirt_ops internals. Specifically, BUG if 722 a paravirt_op is missing when it is called. 723 724config PARAVIRT_SPINLOCKS 725 bool "Paravirtualization layer for spinlocks" 726 depends on PARAVIRT && SMP 727 ---help--- 728 Paravirtualized spinlocks allow a pvops backend to replace the 729 spinlock implementation with something virtualization-friendly 730 (for example, block the virtual CPU rather than spinning). 731 732 It has a minimal impact on native kernels and gives a nice performance 733 benefit on paravirtualized KVM / Xen kernels. 734 735 If you are unsure how to answer this question, answer Y. 736 737config QUEUED_LOCK_STAT 738 bool "Paravirt queued spinlock statistics" 739 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 740 ---help--- 741 Enable the collection of statistical data on the slowpath 742 behavior of paravirtualized queued spinlocks and report 743 them on debugfs. 744 745source "arch/x86/xen/Kconfig" 746 747config KVM_GUEST 748 bool "KVM Guest support (including kvmclock)" 749 depends on PARAVIRT 750 select PARAVIRT_CLOCK 751 default y 752 ---help--- 753 This option enables various optimizations for running under the KVM 754 hypervisor. It includes a paravirtualized clock, so that instead 755 of relying on a PIT (or probably other) emulation by the 756 underlying device model, the host provides the guest with 757 timing infrastructure such as time of day, and system time 758 759config KVM_DEBUG_FS 760 bool "Enable debug information for KVM Guests in debugfs" 761 depends on KVM_GUEST && DEBUG_FS 762 default n 763 ---help--- 764 This option enables collection of various statistics for KVM guest. 765 Statistics are displayed in debugfs filesystem. Enabling this option 766 may incur significant overhead. 767 768source "arch/x86/lguest/Kconfig" 769 770config PARAVIRT_TIME_ACCOUNTING 771 bool "Paravirtual steal time accounting" 772 depends on PARAVIRT 773 default n 774 ---help--- 775 Select this option to enable fine granularity task steal time 776 accounting. Time spent executing other tasks in parallel with 777 the current vCPU is discounted from the vCPU power. To account for 778 that, there can be a small performance impact. 779 780 If in doubt, say N here. 781 782config PARAVIRT_CLOCK 783 bool 784 785endif #HYPERVISOR_GUEST 786 787config NO_BOOTMEM 788 def_bool y 789 790source "arch/x86/Kconfig.cpu" 791 792config HPET_TIMER 793 def_bool X86_64 794 prompt "HPET Timer Support" if X86_32 795 ---help--- 796 Use the IA-PC HPET (High Precision Event Timer) to manage 797 time in preference to the PIT and RTC, if a HPET is 798 present. 799 HPET is the next generation timer replacing legacy 8254s. 800 The HPET provides a stable time base on SMP 801 systems, unlike the TSC, but it is more expensive to access, 802 as it is off-chip. The interface used is documented 803 in the HPET spec, revision 1. 804 805 You can safely choose Y here. However, HPET will only be 806 activated if the platform and the BIOS support this feature. 807 Otherwise the 8254 will be used for timing services. 808 809 Choose N to continue using the legacy 8254 timer. 810 811config HPET_EMULATE_RTC 812 def_bool y 813 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 814 815config APB_TIMER 816 def_bool y if X86_INTEL_MID 817 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 818 select DW_APB_TIMER 819 depends on X86_INTEL_MID && SFI 820 help 821 APB timer is the replacement for 8254, HPET on X86 MID platforms. 822 The APBT provides a stable time base on SMP 823 systems, unlike the TSC, but it is more expensive to access, 824 as it is off-chip. APB timers are always running regardless of CPU 825 C states, they are used as per CPU clockevent device when possible. 826 827# Mark as expert because too many people got it wrong. 828# The code disables itself when not needed. 829config DMI 830 default y 831 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 832 bool "Enable DMI scanning" if EXPERT 833 ---help--- 834 Enabled scanning of DMI to identify machine quirks. Say Y 835 here unless you have verified that your setup is not 836 affected by entries in the DMI blacklist. Required by PNP 837 BIOS code. 838 839config GART_IOMMU 840 bool "Old AMD GART IOMMU support" 841 select SWIOTLB 842 depends on X86_64 && PCI && AMD_NB 843 ---help--- 844 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 845 GART based hardware IOMMUs. 846 847 The GART supports full DMA access for devices with 32-bit access 848 limitations, on systems with more than 3 GB. This is usually needed 849 for USB, sound, many IDE/SATA chipsets and some other devices. 850 851 Newer systems typically have a modern AMD IOMMU, supported via 852 the CONFIG_AMD_IOMMU=y config option. 853 854 In normal configurations this driver is only active when needed: 855 there's more than 3 GB of memory and the system contains a 856 32-bit limited device. 857 858 If unsure, say Y. 859 860config CALGARY_IOMMU 861 bool "IBM Calgary IOMMU support" 862 select SWIOTLB 863 depends on X86_64 && PCI 864 ---help--- 865 Support for hardware IOMMUs in IBM's xSeries x366 and x460 866 systems. Needed to run systems with more than 3GB of memory 867 properly with 32-bit PCI devices that do not support DAC 868 (Double Address Cycle). Calgary also supports bus level 869 isolation, where all DMAs pass through the IOMMU. This 870 prevents them from going anywhere except their intended 871 destination. This catches hard-to-find kernel bugs and 872 mis-behaving drivers and devices that do not use the DMA-API 873 properly to set up their DMA buffers. The IOMMU can be 874 turned off at boot time with the iommu=off parameter. 875 Normally the kernel will make the right choice by itself. 876 If unsure, say Y. 877 878config CALGARY_IOMMU_ENABLED_BY_DEFAULT 879 def_bool y 880 prompt "Should Calgary be enabled by default?" 881 depends on CALGARY_IOMMU 882 ---help--- 883 Should Calgary be enabled by default? if you choose 'y', Calgary 884 will be used (if it exists). If you choose 'n', Calgary will not be 885 used even if it exists. If you choose 'n' and would like to use 886 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 887 If unsure, say Y. 888 889# need this always selected by IOMMU for the VIA workaround 890config SWIOTLB 891 def_bool y if X86_64 892 ---help--- 893 Support for software bounce buffers used on x86-64 systems 894 which don't have a hardware IOMMU. Using this PCI devices 895 which can only access 32-bits of memory can be used on systems 896 with more than 3 GB of memory. 897 If unsure, say Y. 898 899config IOMMU_HELPER 900 def_bool y 901 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 902 903config MAXSMP 904 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 905 depends on X86_64 && SMP && DEBUG_KERNEL 906 select CPUMASK_OFFSTACK 907 ---help--- 908 Enable maximum number of CPUS and NUMA Nodes for this architecture. 909 If unsure, say N. 910 911config NR_CPUS 912 int "Maximum number of CPUs" if SMP && !MAXSMP 913 range 2 8 if SMP && X86_32 && !X86_BIGSMP 914 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 915 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 916 default "1" if !SMP 917 default "8192" if MAXSMP 918 default "32" if SMP && X86_BIGSMP 919 default "8" if SMP && X86_32 920 default "64" if SMP 921 ---help--- 922 This allows you to specify the maximum number of CPUs which this 923 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 924 supported value is 8192, otherwise the maximum value is 512. The 925 minimum value which makes sense is 2. 926 927 This is purely to save memory - each supported CPU adds 928 approximately eight kilobytes to the kernel image. 929 930config SCHED_SMT 931 bool "SMT (Hyperthreading) scheduler support" 932 depends on SMP 933 ---help--- 934 SMT scheduler support improves the CPU scheduler's decision making 935 when dealing with Intel Pentium 4 chips with HyperThreading at a 936 cost of slightly increased overhead in some places. If unsure say 937 N here. 938 939config SCHED_MC 940 def_bool y 941 prompt "Multi-core scheduler support" 942 depends on SMP 943 ---help--- 944 Multi-core scheduler support improves the CPU scheduler's decision 945 making when dealing with multi-core CPU chips at a cost of slightly 946 increased overhead in some places. If unsure say N here. 947 948config SCHED_MC_PRIO 949 bool "CPU core priorities scheduler support" 950 depends on SCHED_MC && CPU_SUP_INTEL 951 select X86_INTEL_PSTATE 952 select CPU_FREQ 953 default y 954 ---help--- 955 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 956 core ordering determined at manufacturing time, which allows 957 certain cores to reach higher turbo frequencies (when running 958 single threaded workloads) than others. 959 960 Enabling this kernel feature teaches the scheduler about 961 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 962 scheduler's CPU selection logic accordingly, so that higher 963 overall system performance can be achieved. 964 965 This feature will have no effect on CPUs without this feature. 966 967 If unsure say Y here. 968 969source "kernel/Kconfig.preempt" 970 971config UP_LATE_INIT 972 def_bool y 973 depends on !SMP && X86_LOCAL_APIC 974 975config X86_UP_APIC 976 bool "Local APIC support on uniprocessors" if !PCI_MSI 977 default PCI_MSI 978 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 979 ---help--- 980 A local APIC (Advanced Programmable Interrupt Controller) is an 981 integrated interrupt controller in the CPU. If you have a single-CPU 982 system which has a processor with a local APIC, you can say Y here to 983 enable and use it. If you say Y here even though your machine doesn't 984 have a local APIC, then the kernel will still run with no slowdown at 985 all. The local APIC supports CPU-generated self-interrupts (timer, 986 performance counters), and the NMI watchdog which detects hard 987 lockups. 988 989config X86_UP_IOAPIC 990 bool "IO-APIC support on uniprocessors" 991 depends on X86_UP_APIC 992 ---help--- 993 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 994 SMP-capable replacement for PC-style interrupt controllers. Most 995 SMP systems and many recent uniprocessor systems have one. 996 997 If you have a single-CPU system with an IO-APIC, you can say Y here 998 to use it. If you say Y here even though your machine doesn't have 999 an IO-APIC, then the kernel will still run with no slowdown at all. 1000 1001config X86_LOCAL_APIC 1002 def_bool y 1003 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1004 select IRQ_DOMAIN_HIERARCHY 1005 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1006 1007config X86_IO_APIC 1008 def_bool y 1009 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1010 1011config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1012 bool "Reroute for broken boot IRQs" 1013 depends on X86_IO_APIC 1014 ---help--- 1015 This option enables a workaround that fixes a source of 1016 spurious interrupts. This is recommended when threaded 1017 interrupt handling is used on systems where the generation of 1018 superfluous "boot interrupts" cannot be disabled. 1019 1020 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1021 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1022 kernel does during interrupt handling). On chipsets where this 1023 boot IRQ generation cannot be disabled, this workaround keeps 1024 the original IRQ line masked so that only the equivalent "boot 1025 IRQ" is delivered to the CPUs. The workaround also tells the 1026 kernel to set up the IRQ handler on the boot IRQ line. In this 1027 way only one interrupt is delivered to the kernel. Otherwise 1028 the spurious second interrupt may cause the kernel to bring 1029 down (vital) interrupt lines. 1030 1031 Only affects "broken" chipsets. Interrupt sharing may be 1032 increased on these systems. 1033 1034config X86_MCE 1035 bool "Machine Check / overheating reporting" 1036 select GENERIC_ALLOCATOR 1037 default y 1038 ---help--- 1039 Machine Check support allows the processor to notify the 1040 kernel if it detects a problem (e.g. overheating, data corruption). 1041 The action the kernel takes depends on the severity of the problem, 1042 ranging from warning messages to halting the machine. 1043 1044config X86_MCE_INTEL 1045 def_bool y 1046 prompt "Intel MCE features" 1047 depends on X86_MCE && X86_LOCAL_APIC 1048 ---help--- 1049 Additional support for intel specific MCE features such as 1050 the thermal monitor. 1051 1052config X86_MCE_AMD 1053 def_bool y 1054 prompt "AMD MCE features" 1055 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1056 ---help--- 1057 Additional support for AMD specific MCE features such as 1058 the DRAM Error Threshold. 1059 1060config X86_ANCIENT_MCE 1061 bool "Support for old Pentium 5 / WinChip machine checks" 1062 depends on X86_32 && X86_MCE 1063 ---help--- 1064 Include support for machine check handling on old Pentium 5 or WinChip 1065 systems. These typically need to be enabled explicitly on the command 1066 line. 1067 1068config X86_MCE_THRESHOLD 1069 depends on X86_MCE_AMD || X86_MCE_INTEL 1070 def_bool y 1071 1072config X86_MCE_INJECT 1073 depends on X86_MCE 1074 tristate "Machine check injector support" 1075 ---help--- 1076 Provide support for injecting machine checks for testing purposes. 1077 If you don't know what a machine check is and you don't do kernel 1078 QA it is safe to say n. 1079 1080config X86_THERMAL_VECTOR 1081 def_bool y 1082 depends on X86_MCE_INTEL 1083 1084source "arch/x86/events/Kconfig" 1085 1086config X86_LEGACY_VM86 1087 bool "Legacy VM86 support" 1088 default n 1089 depends on X86_32 1090 ---help--- 1091 This option allows user programs to put the CPU into V8086 1092 mode, which is an 80286-era approximation of 16-bit real mode. 1093 1094 Some very old versions of X and/or vbetool require this option 1095 for user mode setting. Similarly, DOSEMU will use it if 1096 available to accelerate real mode DOS programs. However, any 1097 recent version of DOSEMU, X, or vbetool should be fully 1098 functional even without kernel VM86 support, as they will all 1099 fall back to software emulation. Nevertheless, if you are using 1100 a 16-bit DOS program where 16-bit performance matters, vm86 1101 mode might be faster than emulation and you might want to 1102 enable this option. 1103 1104 Note that any app that works on a 64-bit kernel is unlikely to 1105 need this option, as 64-bit kernels don't, and can't, support 1106 V8086 mode. This option is also unrelated to 16-bit protected 1107 mode and is not needed to run most 16-bit programs under Wine. 1108 1109 Enabling this option increases the complexity of the kernel 1110 and slows down exception handling a tiny bit. 1111 1112 If unsure, say N here. 1113 1114config VM86 1115 bool 1116 default X86_LEGACY_VM86 1117 1118config X86_16BIT 1119 bool "Enable support for 16-bit segments" if EXPERT 1120 default y 1121 depends on MODIFY_LDT_SYSCALL 1122 ---help--- 1123 This option is required by programs like Wine to run 16-bit 1124 protected mode legacy code on x86 processors. Disabling 1125 this option saves about 300 bytes on i386, or around 6K text 1126 plus 16K runtime memory on x86-64, 1127 1128config X86_ESPFIX32 1129 def_bool y 1130 depends on X86_16BIT && X86_32 1131 1132config X86_ESPFIX64 1133 def_bool y 1134 depends on X86_16BIT && X86_64 1135 1136config X86_VSYSCALL_EMULATION 1137 bool "Enable vsyscall emulation" if EXPERT 1138 default y 1139 depends on X86_64 1140 ---help--- 1141 This enables emulation of the legacy vsyscall page. Disabling 1142 it is roughly equivalent to booting with vsyscall=none, except 1143 that it will also disable the helpful warning if a program 1144 tries to use a vsyscall. With this option set to N, offending 1145 programs will just segfault, citing addresses of the form 1146 0xffffffffff600?00. 1147 1148 This option is required by many programs built before 2013, and 1149 care should be used even with newer programs if set to N. 1150 1151 Disabling this option saves about 7K of kernel size and 1152 possibly 4K of additional runtime pagetable memory. 1153 1154config TOSHIBA 1155 tristate "Toshiba Laptop support" 1156 depends on X86_32 1157 ---help--- 1158 This adds a driver to safely access the System Management Mode of 1159 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1160 not work on models with a Phoenix BIOS. The System Management Mode 1161 is used to set the BIOS and power saving options on Toshiba portables. 1162 1163 For information on utilities to make use of this driver see the 1164 Toshiba Linux utilities web site at: 1165 <http://www.buzzard.org.uk/toshiba/>. 1166 1167 Say Y if you intend to run this kernel on a Toshiba portable. 1168 Say N otherwise. 1169 1170config I8K 1171 tristate "Dell i8k legacy laptop support" 1172 select HWMON 1173 select SENSORS_DELL_SMM 1174 ---help--- 1175 This option enables legacy /proc/i8k userspace interface in hwmon 1176 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1177 temperature and allows controlling fan speeds of Dell laptops via 1178 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1179 it reports also power and hotkey status. For fan speed control is 1180 needed userspace package i8kutils. 1181 1182 Say Y if you intend to run this kernel on old Dell laptops or want to 1183 use userspace package i8kutils. 1184 Say N otherwise. 1185 1186config X86_REBOOTFIXUPS 1187 bool "Enable X86 board specific fixups for reboot" 1188 depends on X86_32 1189 ---help--- 1190 This enables chipset and/or board specific fixups to be done 1191 in order to get reboot to work correctly. This is only needed on 1192 some combinations of hardware and BIOS. The symptom, for which 1193 this config is intended, is when reboot ends with a stalled/hung 1194 system. 1195 1196 Currently, the only fixup is for the Geode machines using 1197 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1198 1199 Say Y if you want to enable the fixup. Currently, it's safe to 1200 enable this option even if you don't need it. 1201 Say N otherwise. 1202 1203config MICROCODE 1204 bool "CPU microcode loading support" 1205 default y 1206 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1207 select FW_LOADER 1208 ---help--- 1209 If you say Y here, you will be able to update the microcode on 1210 Intel and AMD processors. The Intel support is for the IA32 family, 1211 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1212 AMD support is for families 0x10 and later. You will obviously need 1213 the actual microcode binary data itself which is not shipped with 1214 the Linux kernel. 1215 1216 The preferred method to load microcode from a detached initrd is described 1217 in Documentation/x86/early-microcode.txt. For that you need to enable 1218 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1219 initrd for microcode blobs. 1220 1221 In addition, you can build-in the microcode into the kernel. For that you 1222 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1223 to the CONFIG_EXTRA_FIRMWARE config option. 1224 1225config MICROCODE_INTEL 1226 bool "Intel microcode loading support" 1227 depends on MICROCODE 1228 default MICROCODE 1229 select FW_LOADER 1230 ---help--- 1231 This options enables microcode patch loading support for Intel 1232 processors. 1233 1234 For the current Intel microcode data package go to 1235 <https://downloadcenter.intel.com> and search for 1236 'Linux Processor Microcode Data File'. 1237 1238config MICROCODE_AMD 1239 bool "AMD microcode loading support" 1240 depends on MICROCODE 1241 select FW_LOADER 1242 ---help--- 1243 If you select this option, microcode patch loading support for AMD 1244 processors will be enabled. 1245 1246config MICROCODE_OLD_INTERFACE 1247 def_bool y 1248 depends on MICROCODE 1249 1250config X86_MSR 1251 tristate "/dev/cpu/*/msr - Model-specific register support" 1252 ---help--- 1253 This device gives privileged processes access to the x86 1254 Model-Specific Registers (MSRs). It is a character device with 1255 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1256 MSR accesses are directed to a specific CPU on multi-processor 1257 systems. 1258 1259config X86_CPUID 1260 tristate "/dev/cpu/*/cpuid - CPU information support" 1261 ---help--- 1262 This device gives processes access to the x86 CPUID instruction to 1263 be executed on a specific processor. It is a character device 1264 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1265 /dev/cpu/31/cpuid. 1266 1267choice 1268 prompt "High Memory Support" 1269 default HIGHMEM4G 1270 depends on X86_32 1271 1272config NOHIGHMEM 1273 bool "off" 1274 ---help--- 1275 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1276 However, the address space of 32-bit x86 processors is only 4 1277 Gigabytes large. That means that, if you have a large amount of 1278 physical memory, not all of it can be "permanently mapped" by the 1279 kernel. The physical memory that's not permanently mapped is called 1280 "high memory". 1281 1282 If you are compiling a kernel which will never run on a machine with 1283 more than 1 Gigabyte total physical RAM, answer "off" here (default 1284 choice and suitable for most users). This will result in a "3GB/1GB" 1285 split: 3GB are mapped so that each process sees a 3GB virtual memory 1286 space and the remaining part of the 4GB virtual memory space is used 1287 by the kernel to permanently map as much physical memory as 1288 possible. 1289 1290 If the machine has between 1 and 4 Gigabytes physical RAM, then 1291 answer "4GB" here. 1292 1293 If more than 4 Gigabytes is used then answer "64GB" here. This 1294 selection turns Intel PAE (Physical Address Extension) mode on. 1295 PAE implements 3-level paging on IA32 processors. PAE is fully 1296 supported by Linux, PAE mode is implemented on all recent Intel 1297 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1298 then the kernel will not boot on CPUs that don't support PAE! 1299 1300 The actual amount of total physical memory will either be 1301 auto detected or can be forced by using a kernel command line option 1302 such as "mem=256M". (Try "man bootparam" or see the documentation of 1303 your boot loader (lilo or loadlin) about how to pass options to the 1304 kernel at boot time.) 1305 1306 If unsure, say "off". 1307 1308config HIGHMEM4G 1309 bool "4GB" 1310 ---help--- 1311 Select this if you have a 32-bit processor and between 1 and 4 1312 gigabytes of physical RAM. 1313 1314config HIGHMEM64G 1315 bool "64GB" 1316 depends on !M486 1317 select X86_PAE 1318 ---help--- 1319 Select this if you have a 32-bit processor and more than 4 1320 gigabytes of physical RAM. 1321 1322endchoice 1323 1324choice 1325 prompt "Memory split" if EXPERT 1326 default VMSPLIT_3G 1327 depends on X86_32 1328 ---help--- 1329 Select the desired split between kernel and user memory. 1330 1331 If the address range available to the kernel is less than the 1332 physical memory installed, the remaining memory will be available 1333 as "high memory". Accessing high memory is a little more costly 1334 than low memory, as it needs to be mapped into the kernel first. 1335 Note that increasing the kernel address space limits the range 1336 available to user programs, making the address space there 1337 tighter. Selecting anything other than the default 3G/1G split 1338 will also likely make your kernel incompatible with binary-only 1339 kernel modules. 1340 1341 If you are not absolutely sure what you are doing, leave this 1342 option alone! 1343 1344 config VMSPLIT_3G 1345 bool "3G/1G user/kernel split" 1346 config VMSPLIT_3G_OPT 1347 depends on !X86_PAE 1348 bool "3G/1G user/kernel split (for full 1G low memory)" 1349 config VMSPLIT_2G 1350 bool "2G/2G user/kernel split" 1351 config VMSPLIT_2G_OPT 1352 depends on !X86_PAE 1353 bool "2G/2G user/kernel split (for full 2G low memory)" 1354 config VMSPLIT_1G 1355 bool "1G/3G user/kernel split" 1356endchoice 1357 1358config PAGE_OFFSET 1359 hex 1360 default 0xB0000000 if VMSPLIT_3G_OPT 1361 default 0x80000000 if VMSPLIT_2G 1362 default 0x78000000 if VMSPLIT_2G_OPT 1363 default 0x40000000 if VMSPLIT_1G 1364 default 0xC0000000 1365 depends on X86_32 1366 1367config HIGHMEM 1368 def_bool y 1369 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1370 1371config X86_PAE 1372 bool "PAE (Physical Address Extension) Support" 1373 depends on X86_32 && !HIGHMEM4G 1374 select SWIOTLB 1375 ---help--- 1376 PAE is required for NX support, and furthermore enables 1377 larger swapspace support for non-overcommit purposes. It 1378 has the cost of more pagetable lookup overhead, and also 1379 consumes more pagetable space per process. 1380 1381config ARCH_PHYS_ADDR_T_64BIT 1382 def_bool y 1383 depends on X86_64 || X86_PAE 1384 1385config ARCH_DMA_ADDR_T_64BIT 1386 def_bool y 1387 depends on X86_64 || HIGHMEM64G 1388 1389config X86_DIRECT_GBPAGES 1390 def_bool y 1391 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 1392 ---help--- 1393 Certain kernel features effectively disable kernel 1394 linear 1 GB mappings (even if the CPU otherwise 1395 supports them), so don't confuse the user by printing 1396 that we have them enabled. 1397 1398# Common NUMA Features 1399config NUMA 1400 bool "Numa Memory Allocation and Scheduler Support" 1401 depends on SMP 1402 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1403 default y if X86_BIGSMP 1404 ---help--- 1405 Enable NUMA (Non Uniform Memory Access) support. 1406 1407 The kernel will try to allocate memory used by a CPU on the 1408 local memory controller of the CPU and add some more 1409 NUMA awareness to the kernel. 1410 1411 For 64-bit this is recommended if the system is Intel Core i7 1412 (or later), AMD Opteron, or EM64T NUMA. 1413 1414 For 32-bit this is only needed if you boot a 32-bit 1415 kernel on a 64-bit NUMA platform. 1416 1417 Otherwise, you should say N. 1418 1419config AMD_NUMA 1420 def_bool y 1421 prompt "Old style AMD Opteron NUMA detection" 1422 depends on X86_64 && NUMA && PCI 1423 ---help--- 1424 Enable AMD NUMA node topology detection. You should say Y here if 1425 you have a multi processor AMD system. This uses an old method to 1426 read the NUMA configuration directly from the builtin Northbridge 1427 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1428 which also takes priority if both are compiled in. 1429 1430config X86_64_ACPI_NUMA 1431 def_bool y 1432 prompt "ACPI NUMA detection" 1433 depends on X86_64 && NUMA && ACPI && PCI 1434 select ACPI_NUMA 1435 ---help--- 1436 Enable ACPI SRAT based node topology detection. 1437 1438# Some NUMA nodes have memory ranges that span 1439# other nodes. Even though a pfn is valid and 1440# between a node's start and end pfns, it may not 1441# reside on that node. See memmap_init_zone() 1442# for details. 1443config NODES_SPAN_OTHER_NODES 1444 def_bool y 1445 depends on X86_64_ACPI_NUMA 1446 1447config NUMA_EMU 1448 bool "NUMA emulation" 1449 depends on NUMA 1450 ---help--- 1451 Enable NUMA emulation. A flat machine will be split 1452 into virtual nodes when booted with "numa=fake=N", where N is the 1453 number of nodes. This is only useful for debugging. 1454 1455config NODES_SHIFT 1456 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1457 range 1 10 1458 default "10" if MAXSMP 1459 default "6" if X86_64 1460 default "3" 1461 depends on NEED_MULTIPLE_NODES 1462 ---help--- 1463 Specify the maximum number of NUMA Nodes available on the target 1464 system. Increases memory reserved to accommodate various tables. 1465 1466config ARCH_HAVE_MEMORY_PRESENT 1467 def_bool y 1468 depends on X86_32 && DISCONTIGMEM 1469 1470config NEED_NODE_MEMMAP_SIZE 1471 def_bool y 1472 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1473 1474config ARCH_FLATMEM_ENABLE 1475 def_bool y 1476 depends on X86_32 && !NUMA 1477 1478config ARCH_DISCONTIGMEM_ENABLE 1479 def_bool y 1480 depends on NUMA && X86_32 1481 1482config ARCH_DISCONTIGMEM_DEFAULT 1483 def_bool y 1484 depends on NUMA && X86_32 1485 1486config ARCH_SPARSEMEM_ENABLE 1487 def_bool y 1488 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1489 select SPARSEMEM_STATIC if X86_32 1490 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1491 1492config ARCH_SPARSEMEM_DEFAULT 1493 def_bool y 1494 depends on X86_64 1495 1496config ARCH_SELECT_MEMORY_MODEL 1497 def_bool y 1498 depends on ARCH_SPARSEMEM_ENABLE 1499 1500config ARCH_MEMORY_PROBE 1501 bool "Enable sysfs memory/probe interface" 1502 depends on X86_64 && MEMORY_HOTPLUG 1503 help 1504 This option enables a sysfs memory/probe interface for testing. 1505 See Documentation/memory-hotplug.txt for more information. 1506 If you are unsure how to answer this question, answer N. 1507 1508config ARCH_PROC_KCORE_TEXT 1509 def_bool y 1510 depends on X86_64 && PROC_KCORE 1511 1512config ILLEGAL_POINTER_VALUE 1513 hex 1514 default 0 if X86_32 1515 default 0xdead000000000000 if X86_64 1516 1517source "mm/Kconfig" 1518 1519config X86_PMEM_LEGACY_DEVICE 1520 bool 1521 1522config X86_PMEM_LEGACY 1523 tristate "Support non-standard NVDIMMs and ADR protected memory" 1524 depends on PHYS_ADDR_T_64BIT 1525 depends on BLK_DEV 1526 select X86_PMEM_LEGACY_DEVICE 1527 select LIBNVDIMM 1528 help 1529 Treat memory marked using the non-standard e820 type of 12 as used 1530 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1531 The kernel will offer these regions to the 'pmem' driver so 1532 they can be used for persistent storage. 1533 1534 Say Y if unsure. 1535 1536config HIGHPTE 1537 bool "Allocate 3rd-level pagetables from highmem" 1538 depends on HIGHMEM 1539 ---help--- 1540 The VM uses one page table entry for each page of physical memory. 1541 For systems with a lot of RAM, this can be wasteful of precious 1542 low memory. Setting this option will put user-space page table 1543 entries in high memory. 1544 1545config X86_CHECK_BIOS_CORRUPTION 1546 bool "Check for low memory corruption" 1547 ---help--- 1548 Periodically check for memory corruption in low memory, which 1549 is suspected to be caused by BIOS. Even when enabled in the 1550 configuration, it is disabled at runtime. Enable it by 1551 setting "memory_corruption_check=1" on the kernel command 1552 line. By default it scans the low 64k of memory every 60 1553 seconds; see the memory_corruption_check_size and 1554 memory_corruption_check_period parameters in 1555 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1556 1557 When enabled with the default parameters, this option has 1558 almost no overhead, as it reserves a relatively small amount 1559 of memory and scans it infrequently. It both detects corruption 1560 and prevents it from affecting the running system. 1561 1562 It is, however, intended as a diagnostic tool; if repeatable 1563 BIOS-originated corruption always affects the same memory, 1564 you can use memmap= to prevent the kernel from using that 1565 memory. 1566 1567config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1568 bool "Set the default setting of memory_corruption_check" 1569 depends on X86_CHECK_BIOS_CORRUPTION 1570 default y 1571 ---help--- 1572 Set whether the default state of memory_corruption_check is 1573 on or off. 1574 1575config X86_RESERVE_LOW 1576 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1577 default 64 1578 range 4 640 1579 ---help--- 1580 Specify the amount of low memory to reserve for the BIOS. 1581 1582 The first page contains BIOS data structures that the kernel 1583 must not use, so that page must always be reserved. 1584 1585 By default we reserve the first 64K of physical RAM, as a 1586 number of BIOSes are known to corrupt that memory range 1587 during events such as suspend/resume or monitor cable 1588 insertion, so it must not be used by the kernel. 1589 1590 You can set this to 4 if you are absolutely sure that you 1591 trust the BIOS to get all its memory reservations and usages 1592 right. If you know your BIOS have problems beyond the 1593 default 64K area, you can set this to 640 to avoid using the 1594 entire low memory range. 1595 1596 If you have doubts about the BIOS (e.g. suspend/resume does 1597 not work or there's kernel crashes after certain hardware 1598 hotplug events) then you might want to enable 1599 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1600 typical corruption patterns. 1601 1602 Leave this to the default value of 64 if you are unsure. 1603 1604config MATH_EMULATION 1605 bool 1606 depends on MODIFY_LDT_SYSCALL 1607 prompt "Math emulation" if X86_32 1608 ---help--- 1609 Linux can emulate a math coprocessor (used for floating point 1610 operations) if you don't have one. 486DX and Pentium processors have 1611 a math coprocessor built in, 486SX and 386 do not, unless you added 1612 a 487DX or 387, respectively. (The messages during boot time can 1613 give you some hints here ["man dmesg"].) Everyone needs either a 1614 coprocessor or this emulation. 1615 1616 If you don't have a math coprocessor, you need to say Y here; if you 1617 say Y here even though you have a coprocessor, the coprocessor will 1618 be used nevertheless. (This behavior can be changed with the kernel 1619 command line option "no387", which comes handy if your coprocessor 1620 is broken. Try "man bootparam" or see the documentation of your boot 1621 loader (lilo or loadlin) about how to pass options to the kernel at 1622 boot time.) This means that it is a good idea to say Y here if you 1623 intend to use this kernel on different machines. 1624 1625 More information about the internals of the Linux math coprocessor 1626 emulation can be found in <file:arch/x86/math-emu/README>. 1627 1628 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1629 kernel, it won't hurt. 1630 1631config MTRR 1632 def_bool y 1633 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1634 ---help--- 1635 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1636 the Memory Type Range Registers (MTRRs) may be used to control 1637 processor access to memory ranges. This is most useful if you have 1638 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1639 allows bus write transfers to be combined into a larger transfer 1640 before bursting over the PCI/AGP bus. This can increase performance 1641 of image write operations 2.5 times or more. Saying Y here creates a 1642 /proc/mtrr file which may be used to manipulate your processor's 1643 MTRRs. Typically the X server should use this. 1644 1645 This code has a reasonably generic interface so that similar 1646 control registers on other processors can be easily supported 1647 as well: 1648 1649 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1650 Registers (ARRs) which provide a similar functionality to MTRRs. For 1651 these, the ARRs are used to emulate the MTRRs. 1652 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1653 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1654 write-combining. All of these processors are supported by this code 1655 and it makes sense to say Y here if you have one of them. 1656 1657 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1658 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1659 can lead to all sorts of problems, so it's good to say Y here. 1660 1661 You can safely say Y even if your machine doesn't have MTRRs, you'll 1662 just add about 9 KB to your kernel. 1663 1664 See <file:Documentation/x86/mtrr.txt> for more information. 1665 1666config MTRR_SANITIZER 1667 def_bool y 1668 prompt "MTRR cleanup support" 1669 depends on MTRR 1670 ---help--- 1671 Convert MTRR layout from continuous to discrete, so X drivers can 1672 add writeback entries. 1673 1674 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1675 The largest mtrr entry size for a continuous block can be set with 1676 mtrr_chunk_size. 1677 1678 If unsure, say Y. 1679 1680config MTRR_SANITIZER_ENABLE_DEFAULT 1681 int "MTRR cleanup enable value (0-1)" 1682 range 0 1 1683 default "0" 1684 depends on MTRR_SANITIZER 1685 ---help--- 1686 Enable mtrr cleanup default value 1687 1688config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1689 int "MTRR cleanup spare reg num (0-7)" 1690 range 0 7 1691 default "1" 1692 depends on MTRR_SANITIZER 1693 ---help--- 1694 mtrr cleanup spare entries default, it can be changed via 1695 mtrr_spare_reg_nr=N on the kernel command line. 1696 1697config X86_PAT 1698 def_bool y 1699 prompt "x86 PAT support" if EXPERT 1700 depends on MTRR 1701 ---help--- 1702 Use PAT attributes to setup page level cache control. 1703 1704 PATs are the modern equivalents of MTRRs and are much more 1705 flexible than MTRRs. 1706 1707 Say N here if you see bootup problems (boot crash, boot hang, 1708 spontaneous reboots) or a non-working video driver. 1709 1710 If unsure, say Y. 1711 1712config ARCH_USES_PG_UNCACHED 1713 def_bool y 1714 depends on X86_PAT 1715 1716config ARCH_RANDOM 1717 def_bool y 1718 prompt "x86 architectural random number generator" if EXPERT 1719 ---help--- 1720 Enable the x86 architectural RDRAND instruction 1721 (Intel Bull Mountain technology) to generate random numbers. 1722 If supported, this is a high bandwidth, cryptographically 1723 secure hardware random number generator. 1724 1725config X86_SMAP 1726 def_bool y 1727 prompt "Supervisor Mode Access Prevention" if EXPERT 1728 ---help--- 1729 Supervisor Mode Access Prevention (SMAP) is a security 1730 feature in newer Intel processors. There is a small 1731 performance cost if this enabled and turned on; there is 1732 also a small increase in the kernel size if this is enabled. 1733 1734 If unsure, say Y. 1735 1736config X86_INTEL_MPX 1737 prompt "Intel MPX (Memory Protection Extensions)" 1738 def_bool n 1739 depends on CPU_SUP_INTEL 1740 ---help--- 1741 MPX provides hardware features that can be used in 1742 conjunction with compiler-instrumented code to check 1743 memory references. It is designed to detect buffer 1744 overflow or underflow bugs. 1745 1746 This option enables running applications which are 1747 instrumented or otherwise use MPX. It does not use MPX 1748 itself inside the kernel or to protect the kernel 1749 against bad memory references. 1750 1751 Enabling this option will make the kernel larger: 1752 ~8k of kernel text and 36 bytes of data on a 64-bit 1753 defconfig. It adds a long to the 'mm_struct' which 1754 will increase the kernel memory overhead of each 1755 process and adds some branches to paths used during 1756 exec() and munmap(). 1757 1758 For details, see Documentation/x86/intel_mpx.txt 1759 1760 If unsure, say N. 1761 1762config X86_INTEL_MEMORY_PROTECTION_KEYS 1763 prompt "Intel Memory Protection Keys" 1764 def_bool y 1765 # Note: only available in 64-bit mode 1766 depends on CPU_SUP_INTEL && X86_64 1767 select ARCH_USES_HIGH_VMA_FLAGS 1768 select ARCH_HAS_PKEYS 1769 ---help--- 1770 Memory Protection Keys provides a mechanism for enforcing 1771 page-based protections, but without requiring modification of the 1772 page tables when an application changes protection domains. 1773 1774 For details, see Documentation/x86/protection-keys.txt 1775 1776 If unsure, say y. 1777 1778config EFI 1779 bool "EFI runtime service support" 1780 depends on ACPI 1781 select UCS2_STRING 1782 select EFI_RUNTIME_WRAPPERS 1783 ---help--- 1784 This enables the kernel to use EFI runtime services that are 1785 available (such as the EFI variable services). 1786 1787 This option is only useful on systems that have EFI firmware. 1788 In addition, you should use the latest ELILO loader available 1789 at <http://elilo.sourceforge.net> in order to take advantage 1790 of EFI runtime services. However, even with this option, the 1791 resultant kernel should continue to boot on existing non-EFI 1792 platforms. 1793 1794config EFI_STUB 1795 bool "EFI stub support" 1796 depends on EFI && !X86_USE_3DNOW 1797 select RELOCATABLE 1798 ---help--- 1799 This kernel feature allows a bzImage to be loaded directly 1800 by EFI firmware without the use of a bootloader. 1801 1802 See Documentation/efi-stub.txt for more information. 1803 1804config EFI_MIXED 1805 bool "EFI mixed-mode support" 1806 depends on EFI_STUB && X86_64 1807 ---help--- 1808 Enabling this feature allows a 64-bit kernel to be booted 1809 on a 32-bit firmware, provided that your CPU supports 64-bit 1810 mode. 1811 1812 Note that it is not possible to boot a mixed-mode enabled 1813 kernel via the EFI boot stub - a bootloader that supports 1814 the EFI handover protocol must be used. 1815 1816 If unsure, say N. 1817 1818config SECCOMP 1819 def_bool y 1820 prompt "Enable seccomp to safely compute untrusted bytecode" 1821 ---help--- 1822 This kernel feature is useful for number crunching applications 1823 that may need to compute untrusted bytecode during their 1824 execution. By using pipes or other transports made available to 1825 the process as file descriptors supporting the read/write 1826 syscalls, it's possible to isolate those applications in 1827 their own address space using seccomp. Once seccomp is 1828 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1829 and the task is only allowed to execute a few safe syscalls 1830 defined by each seccomp mode. 1831 1832 If unsure, say Y. Only embedded should say N here. 1833 1834source kernel/Kconfig.hz 1835 1836config KEXEC 1837 bool "kexec system call" 1838 select KEXEC_CORE 1839 ---help--- 1840 kexec is a system call that implements the ability to shutdown your 1841 current kernel, and to start another kernel. It is like a reboot 1842 but it is independent of the system firmware. And like a reboot 1843 you can start any kernel with it, not just Linux. 1844 1845 The name comes from the similarity to the exec system call. 1846 1847 It is an ongoing process to be certain the hardware in a machine 1848 is properly shutdown, so do not be surprised if this code does not 1849 initially work for you. As of this writing the exact hardware 1850 interface is strongly in flux, so no good recommendation can be 1851 made. 1852 1853config KEXEC_FILE 1854 bool "kexec file based system call" 1855 select KEXEC_CORE 1856 select BUILD_BIN2C 1857 depends on X86_64 1858 depends on CRYPTO=y 1859 depends on CRYPTO_SHA256=y 1860 ---help--- 1861 This is new version of kexec system call. This system call is 1862 file based and takes file descriptors as system call argument 1863 for kernel and initramfs as opposed to list of segments as 1864 accepted by previous system call. 1865 1866config KEXEC_VERIFY_SIG 1867 bool "Verify kernel signature during kexec_file_load() syscall" 1868 depends on KEXEC_FILE 1869 ---help--- 1870 This option makes kernel signature verification mandatory for 1871 the kexec_file_load() syscall. 1872 1873 In addition to that option, you need to enable signature 1874 verification for the corresponding kernel image type being 1875 loaded in order for this to work. 1876 1877config KEXEC_BZIMAGE_VERIFY_SIG 1878 bool "Enable bzImage signature verification support" 1879 depends on KEXEC_VERIFY_SIG 1880 depends on SIGNED_PE_FILE_VERIFICATION 1881 select SYSTEM_TRUSTED_KEYRING 1882 ---help--- 1883 Enable bzImage signature verification support. 1884 1885config CRASH_DUMP 1886 bool "kernel crash dumps" 1887 depends on X86_64 || (X86_32 && HIGHMEM) 1888 ---help--- 1889 Generate crash dump after being started by kexec. 1890 This should be normally only set in special crash dump kernels 1891 which are loaded in the main kernel with kexec-tools into 1892 a specially reserved region and then later executed after 1893 a crash by kdump/kexec. The crash dump kernel must be compiled 1894 to a memory address not used by the main kernel or BIOS using 1895 PHYSICAL_START, or it must be built as a relocatable image 1896 (CONFIG_RELOCATABLE=y). 1897 For more details see Documentation/kdump/kdump.txt 1898 1899config KEXEC_JUMP 1900 bool "kexec jump" 1901 depends on KEXEC && HIBERNATION 1902 ---help--- 1903 Jump between original kernel and kexeced kernel and invoke 1904 code in physical address mode via KEXEC 1905 1906config PHYSICAL_START 1907 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1908 default "0x1000000" 1909 ---help--- 1910 This gives the physical address where the kernel is loaded. 1911 1912 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1913 bzImage will decompress itself to above physical address and 1914 run from there. Otherwise, bzImage will run from the address where 1915 it has been loaded by the boot loader and will ignore above physical 1916 address. 1917 1918 In normal kdump cases one does not have to set/change this option 1919 as now bzImage can be compiled as a completely relocatable image 1920 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1921 address. This option is mainly useful for the folks who don't want 1922 to use a bzImage for capturing the crash dump and want to use a 1923 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1924 to be specifically compiled to run from a specific memory area 1925 (normally a reserved region) and this option comes handy. 1926 1927 So if you are using bzImage for capturing the crash dump, 1928 leave the value here unchanged to 0x1000000 and set 1929 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1930 for capturing the crash dump change this value to start of 1931 the reserved region. In other words, it can be set based on 1932 the "X" value as specified in the "crashkernel=YM@XM" 1933 command line boot parameter passed to the panic-ed 1934 kernel. Please take a look at Documentation/kdump/kdump.txt 1935 for more details about crash dumps. 1936 1937 Usage of bzImage for capturing the crash dump is recommended as 1938 one does not have to build two kernels. Same kernel can be used 1939 as production kernel and capture kernel. Above option should have 1940 gone away after relocatable bzImage support is introduced. But it 1941 is present because there are users out there who continue to use 1942 vmlinux for dump capture. This option should go away down the 1943 line. 1944 1945 Don't change this unless you know what you are doing. 1946 1947config RELOCATABLE 1948 bool "Build a relocatable kernel" 1949 default y 1950 ---help--- 1951 This builds a kernel image that retains relocation information 1952 so it can be loaded someplace besides the default 1MB. 1953 The relocations tend to make the kernel binary about 10% larger, 1954 but are discarded at runtime. 1955 1956 One use is for the kexec on panic case where the recovery kernel 1957 must live at a different physical address than the primary 1958 kernel. 1959 1960 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1961 it has been loaded at and the compile time physical address 1962 (CONFIG_PHYSICAL_START) is used as the minimum location. 1963 1964config RANDOMIZE_BASE 1965 bool "Randomize the address of the kernel image (KASLR)" 1966 depends on RELOCATABLE 1967 default n 1968 ---help--- 1969 In support of Kernel Address Space Layout Randomization (KASLR), 1970 this randomizes the physical address at which the kernel image 1971 is decompressed and the virtual address where the kernel 1972 image is mapped, as a security feature that deters exploit 1973 attempts relying on knowledge of the location of kernel 1974 code internals. 1975 1976 On 64-bit, the kernel physical and virtual addresses are 1977 randomized separately. The physical address will be anywhere 1978 between 16MB and the top of physical memory (up to 64TB). The 1979 virtual address will be randomized from 16MB up to 1GB (9 bits 1980 of entropy). Note that this also reduces the memory space 1981 available to kernel modules from 1.5GB to 1GB. 1982 1983 On 32-bit, the kernel physical and virtual addresses are 1984 randomized together. They will be randomized from 16MB up to 1985 512MB (8 bits of entropy). 1986 1987 Entropy is generated using the RDRAND instruction if it is 1988 supported. If RDTSC is supported, its value is mixed into 1989 the entropy pool as well. If neither RDRAND nor RDTSC are 1990 supported, then entropy is read from the i8254 timer. The 1991 usable entropy is limited by the kernel being built using 1992 2GB addressing, and that PHYSICAL_ALIGN must be at a 1993 minimum of 2MB. As a result, only 10 bits of entropy are 1994 theoretically possible, but the implementations are further 1995 limited due to memory layouts. 1996 1997 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot 1998 time. To enable it, boot with "kaslr" on the kernel command 1999 line (which will also disable hibernation). 2000 2001 If unsure, say N. 2002 2003# Relocation on x86 needs some additional build support 2004config X86_NEED_RELOCS 2005 def_bool y 2006 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2007 2008config PHYSICAL_ALIGN 2009 hex "Alignment value to which kernel should be aligned" 2010 default "0x200000" 2011 range 0x2000 0x1000000 if X86_32 2012 range 0x200000 0x1000000 if X86_64 2013 ---help--- 2014 This value puts the alignment restrictions on physical address 2015 where kernel is loaded and run from. Kernel is compiled for an 2016 address which meets above alignment restriction. 2017 2018 If bootloader loads the kernel at a non-aligned address and 2019 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2020 address aligned to above value and run from there. 2021 2022 If bootloader loads the kernel at a non-aligned address and 2023 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2024 load address and decompress itself to the address it has been 2025 compiled for and run from there. The address for which kernel is 2026 compiled already meets above alignment restrictions. Hence the 2027 end result is that kernel runs from a physical address meeting 2028 above alignment restrictions. 2029 2030 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2031 this value must be a multiple of 0x200000. 2032 2033 Don't change this unless you know what you are doing. 2034 2035config RANDOMIZE_MEMORY 2036 bool "Randomize the kernel memory sections" 2037 depends on X86_64 2038 depends on RANDOMIZE_BASE 2039 default RANDOMIZE_BASE 2040 ---help--- 2041 Randomizes the base virtual address of kernel memory sections 2042 (physical memory mapping, vmalloc & vmemmap). This security feature 2043 makes exploits relying on predictable memory locations less reliable. 2044 2045 The order of allocations remains unchanged. Entropy is generated in 2046 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2047 configuration have in average 30,000 different possible virtual 2048 addresses for each memory section. 2049 2050 If unsure, say N. 2051 2052config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2053 hex "Physical memory mapping padding" if EXPERT 2054 depends on RANDOMIZE_MEMORY 2055 default "0xa" if MEMORY_HOTPLUG 2056 default "0x0" 2057 range 0x1 0x40 if MEMORY_HOTPLUG 2058 range 0x0 0x40 2059 ---help--- 2060 Define the padding in terabytes added to the existing physical 2061 memory size during kernel memory randomization. It is useful 2062 for memory hotplug support but reduces the entropy available for 2063 address randomization. 2064 2065 If unsure, leave at the default value. 2066 2067config HOTPLUG_CPU 2068 bool "Support for hot-pluggable CPUs" 2069 depends on SMP 2070 ---help--- 2071 Say Y here to allow turning CPUs off and on. CPUs can be 2072 controlled through /sys/devices/system/cpu. 2073 ( Note: power management support will enable this option 2074 automatically on SMP systems. ) 2075 Say N if you want to disable CPU hotplug. 2076 2077config BOOTPARAM_HOTPLUG_CPU0 2078 bool "Set default setting of cpu0_hotpluggable" 2079 default n 2080 depends on HOTPLUG_CPU 2081 ---help--- 2082 Set whether default state of cpu0_hotpluggable is on or off. 2083 2084 Say Y here to enable CPU0 hotplug by default. If this switch 2085 is turned on, there is no need to give cpu0_hotplug kernel 2086 parameter and the CPU0 hotplug feature is enabled by default. 2087 2088 Please note: there are two known CPU0 dependencies if you want 2089 to enable the CPU0 hotplug feature either by this switch or by 2090 cpu0_hotplug kernel parameter. 2091 2092 First, resume from hibernate or suspend always starts from CPU0. 2093 So hibernate and suspend are prevented if CPU0 is offline. 2094 2095 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2096 offline if any interrupt can not migrate out of CPU0. There may 2097 be other CPU0 dependencies. 2098 2099 Please make sure the dependencies are under your control before 2100 you enable this feature. 2101 2102 Say N if you don't want to enable CPU0 hotplug feature by default. 2103 You still can enable the CPU0 hotplug feature at boot by kernel 2104 parameter cpu0_hotplug. 2105 2106config DEBUG_HOTPLUG_CPU0 2107 def_bool n 2108 prompt "Debug CPU0 hotplug" 2109 depends on HOTPLUG_CPU 2110 ---help--- 2111 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2112 soon as possible and boots up userspace with CPU0 offlined. User 2113 can online CPU0 back after boot time. 2114 2115 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2116 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2117 compilation or giving cpu0_hotplug kernel parameter at boot. 2118 2119 If unsure, say N. 2120 2121config COMPAT_VDSO 2122 def_bool n 2123 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2124 depends on COMPAT_32 2125 ---help--- 2126 Certain buggy versions of glibc will crash if they are 2127 presented with a 32-bit vDSO that is not mapped at the address 2128 indicated in its segment table. 2129 2130 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2131 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2132 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2133 the only released version with the bug, but OpenSUSE 9 2134 contains a buggy "glibc 2.3.2". 2135 2136 The symptom of the bug is that everything crashes on startup, saying: 2137 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2138 2139 Saying Y here changes the default value of the vdso32 boot 2140 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2141 This works around the glibc bug but hurts performance. 2142 2143 If unsure, say N: if you are compiling your own kernel, you 2144 are unlikely to be using a buggy version of glibc. 2145 2146choice 2147 prompt "vsyscall table for legacy applications" 2148 depends on X86_64 2149 default LEGACY_VSYSCALL_EMULATE 2150 help 2151 Legacy user code that does not know how to find the vDSO expects 2152 to be able to issue three syscalls by calling fixed addresses in 2153 kernel space. Since this location is not randomized with ASLR, 2154 it can be used to assist security vulnerability exploitation. 2155 2156 This setting can be changed at boot time via the kernel command 2157 line parameter vsyscall=[native|emulate|none]. 2158 2159 On a system with recent enough glibc (2.14 or newer) and no 2160 static binaries, you can say None without a performance penalty 2161 to improve security. 2162 2163 If unsure, select "Emulate". 2164 2165 config LEGACY_VSYSCALL_NATIVE 2166 bool "Native" 2167 help 2168 Actual executable code is located in the fixed vsyscall 2169 address mapping, implementing time() efficiently. Since 2170 this makes the mapping executable, it can be used during 2171 security vulnerability exploitation (traditionally as 2172 ROP gadgets). This configuration is not recommended. 2173 2174 config LEGACY_VSYSCALL_EMULATE 2175 bool "Emulate" 2176 help 2177 The kernel traps and emulates calls into the fixed 2178 vsyscall address mapping. This makes the mapping 2179 non-executable, but it still contains known contents, 2180 which could be used in certain rare security vulnerability 2181 exploits. This configuration is recommended when userspace 2182 still uses the vsyscall area. 2183 2184 config LEGACY_VSYSCALL_NONE 2185 bool "None" 2186 help 2187 There will be no vsyscall mapping at all. This will 2188 eliminate any risk of ASLR bypass due to the vsyscall 2189 fixed address mapping. Attempts to use the vsyscalls 2190 will be reported to dmesg, so that either old or 2191 malicious userspace programs can be identified. 2192 2193endchoice 2194 2195config CMDLINE_BOOL 2196 bool "Built-in kernel command line" 2197 ---help--- 2198 Allow for specifying boot arguments to the kernel at 2199 build time. On some systems (e.g. embedded ones), it is 2200 necessary or convenient to provide some or all of the 2201 kernel boot arguments with the kernel itself (that is, 2202 to not rely on the boot loader to provide them.) 2203 2204 To compile command line arguments into the kernel, 2205 set this option to 'Y', then fill in the 2206 boot arguments in CONFIG_CMDLINE. 2207 2208 Systems with fully functional boot loaders (i.e. non-embedded) 2209 should leave this option set to 'N'. 2210 2211config CMDLINE 2212 string "Built-in kernel command string" 2213 depends on CMDLINE_BOOL 2214 default "" 2215 ---help--- 2216 Enter arguments here that should be compiled into the kernel 2217 image and used at boot time. If the boot loader provides a 2218 command line at boot time, it is appended to this string to 2219 form the full kernel command line, when the system boots. 2220 2221 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2222 change this behavior. 2223 2224 In most cases, the command line (whether built-in or provided 2225 by the boot loader) should specify the device for the root 2226 file system. 2227 2228config CMDLINE_OVERRIDE 2229 bool "Built-in command line overrides boot loader arguments" 2230 depends on CMDLINE_BOOL 2231 ---help--- 2232 Set this option to 'Y' to have the kernel ignore the boot loader 2233 command line, and use ONLY the built-in command line. 2234 2235 This is used to work around broken boot loaders. This should 2236 be set to 'N' under normal conditions. 2237 2238config MODIFY_LDT_SYSCALL 2239 bool "Enable the LDT (local descriptor table)" if EXPERT 2240 default y 2241 ---help--- 2242 Linux can allow user programs to install a per-process x86 2243 Local Descriptor Table (LDT) using the modify_ldt(2) system 2244 call. This is required to run 16-bit or segmented code such as 2245 DOSEMU or some Wine programs. It is also used by some very old 2246 threading libraries. 2247 2248 Enabling this feature adds a small amount of overhead to 2249 context switches and increases the low-level kernel attack 2250 surface. Disabling it removes the modify_ldt(2) system call. 2251 2252 Saying 'N' here may make sense for embedded or server kernels. 2253 2254source "kernel/livepatch/Kconfig" 2255 2256endmenu 2257 2258config ARCH_ENABLE_MEMORY_HOTPLUG 2259 def_bool y 2260 depends on X86_64 || (X86_32 && HIGHMEM) 2261 2262config ARCH_ENABLE_MEMORY_HOTREMOVE 2263 def_bool y 2264 depends on MEMORY_HOTPLUG 2265 2266config USE_PERCPU_NUMA_NODE_ID 2267 def_bool y 2268 depends on NUMA 2269 2270config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2271 def_bool y 2272 depends on X86_64 || X86_PAE 2273 2274config ARCH_ENABLE_HUGEPAGE_MIGRATION 2275 def_bool y 2276 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2277 2278menu "Power management and ACPI options" 2279 2280config ARCH_HIBERNATION_HEADER 2281 def_bool y 2282 depends on X86_64 && HIBERNATION 2283 2284source "kernel/power/Kconfig" 2285 2286source "drivers/acpi/Kconfig" 2287 2288source "drivers/sfi/Kconfig" 2289 2290config X86_APM_BOOT 2291 def_bool y 2292 depends on APM 2293 2294menuconfig APM 2295 tristate "APM (Advanced Power Management) BIOS support" 2296 depends on X86_32 && PM_SLEEP 2297 ---help--- 2298 APM is a BIOS specification for saving power using several different 2299 techniques. This is mostly useful for battery powered laptops with 2300 APM compliant BIOSes. If you say Y here, the system time will be 2301 reset after a RESUME operation, the /proc/apm device will provide 2302 battery status information, and user-space programs will receive 2303 notification of APM "events" (e.g. battery status change). 2304 2305 If you select "Y" here, you can disable actual use of the APM 2306 BIOS by passing the "apm=off" option to the kernel at boot time. 2307 2308 Note that the APM support is almost completely disabled for 2309 machines with more than one CPU. 2310 2311 In order to use APM, you will need supporting software. For location 2312 and more information, read <file:Documentation/power/apm-acpi.txt> 2313 and the Battery Powered Linux mini-HOWTO, available from 2314 <http://www.tldp.org/docs.html#howto>. 2315 2316 This driver does not spin down disk drives (see the hdparm(8) 2317 manpage ("man 8 hdparm") for that), and it doesn't turn off 2318 VESA-compliant "green" monitors. 2319 2320 This driver does not support the TI 4000M TravelMate and the ACER 2321 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2322 desktop machines also don't have compliant BIOSes, and this driver 2323 may cause those machines to panic during the boot phase. 2324 2325 Generally, if you don't have a battery in your machine, there isn't 2326 much point in using this driver and you should say N. If you get 2327 random kernel OOPSes or reboots that don't seem to be related to 2328 anything, try disabling/enabling this option (or disabling/enabling 2329 APM in your BIOS). 2330 2331 Some other things you should try when experiencing seemingly random, 2332 "weird" problems: 2333 2334 1) make sure that you have enough swap space and that it is 2335 enabled. 2336 2) pass the "no-hlt" option to the kernel 2337 3) switch on floating point emulation in the kernel and pass 2338 the "no387" option to the kernel 2339 4) pass the "floppy=nodma" option to the kernel 2340 5) pass the "mem=4M" option to the kernel (thereby disabling 2341 all but the first 4 MB of RAM) 2342 6) make sure that the CPU is not over clocked. 2343 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2344 8) disable the cache from your BIOS settings 2345 9) install a fan for the video card or exchange video RAM 2346 10) install a better fan for the CPU 2347 11) exchange RAM chips 2348 12) exchange the motherboard. 2349 2350 To compile this driver as a module, choose M here: the 2351 module will be called apm. 2352 2353if APM 2354 2355config APM_IGNORE_USER_SUSPEND 2356 bool "Ignore USER SUSPEND" 2357 ---help--- 2358 This option will ignore USER SUSPEND requests. On machines with a 2359 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2360 series notebooks, it is necessary to say Y because of a BIOS bug. 2361 2362config APM_DO_ENABLE 2363 bool "Enable PM at boot time" 2364 ---help--- 2365 Enable APM features at boot time. From page 36 of the APM BIOS 2366 specification: "When disabled, the APM BIOS does not automatically 2367 power manage devices, enter the Standby State, enter the Suspend 2368 State, or take power saving steps in response to CPU Idle calls." 2369 This driver will make CPU Idle calls when Linux is idle (unless this 2370 feature is turned off -- see "Do CPU IDLE calls", below). This 2371 should always save battery power, but more complicated APM features 2372 will be dependent on your BIOS implementation. You may need to turn 2373 this option off if your computer hangs at boot time when using APM 2374 support, or if it beeps continuously instead of suspending. Turn 2375 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2376 T400CDT. This is off by default since most machines do fine without 2377 this feature. 2378 2379config APM_CPU_IDLE 2380 depends on CPU_IDLE 2381 bool "Make CPU Idle calls when idle" 2382 ---help--- 2383 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2384 On some machines, this can activate improved power savings, such as 2385 a slowed CPU clock rate, when the machine is idle. These idle calls 2386 are made after the idle loop has run for some length of time (e.g., 2387 333 mS). On some machines, this will cause a hang at boot time or 2388 whenever the CPU becomes idle. (On machines with more than one CPU, 2389 this option does nothing.) 2390 2391config APM_DISPLAY_BLANK 2392 bool "Enable console blanking using APM" 2393 ---help--- 2394 Enable console blanking using the APM. Some laptops can use this to 2395 turn off the LCD backlight when the screen blanker of the Linux 2396 virtual console blanks the screen. Note that this is only used by 2397 the virtual console screen blanker, and won't turn off the backlight 2398 when using the X Window system. This also doesn't have anything to 2399 do with your VESA-compliant power-saving monitor. Further, this 2400 option doesn't work for all laptops -- it might not turn off your 2401 backlight at all, or it might print a lot of errors to the console, 2402 especially if you are using gpm. 2403 2404config APM_ALLOW_INTS 2405 bool "Allow interrupts during APM BIOS calls" 2406 ---help--- 2407 Normally we disable external interrupts while we are making calls to 2408 the APM BIOS as a measure to lessen the effects of a badly behaving 2409 BIOS implementation. The BIOS should reenable interrupts if it 2410 needs to. Unfortunately, some BIOSes do not -- especially those in 2411 many of the newer IBM Thinkpads. If you experience hangs when you 2412 suspend, try setting this to Y. Otherwise, say N. 2413 2414endif # APM 2415 2416source "drivers/cpufreq/Kconfig" 2417 2418source "drivers/cpuidle/Kconfig" 2419 2420source "drivers/idle/Kconfig" 2421 2422endmenu 2423 2424 2425menu "Bus options (PCI etc.)" 2426 2427config PCI 2428 bool "PCI support" 2429 default y 2430 ---help--- 2431 Find out whether you have a PCI motherboard. PCI is the name of a 2432 bus system, i.e. the way the CPU talks to the other stuff inside 2433 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2434 VESA. If you have PCI, say Y, otherwise N. 2435 2436choice 2437 prompt "PCI access mode" 2438 depends on X86_32 && PCI 2439 default PCI_GOANY 2440 ---help--- 2441 On PCI systems, the BIOS can be used to detect the PCI devices and 2442 determine their configuration. However, some old PCI motherboards 2443 have BIOS bugs and may crash if this is done. Also, some embedded 2444 PCI-based systems don't have any BIOS at all. Linux can also try to 2445 detect the PCI hardware directly without using the BIOS. 2446 2447 With this option, you can specify how Linux should detect the 2448 PCI devices. If you choose "BIOS", the BIOS will be used, 2449 if you choose "Direct", the BIOS won't be used, and if you 2450 choose "MMConfig", then PCI Express MMCONFIG will be used. 2451 If you choose "Any", the kernel will try MMCONFIG, then the 2452 direct access method and falls back to the BIOS if that doesn't 2453 work. If unsure, go with the default, which is "Any". 2454 2455config PCI_GOBIOS 2456 bool "BIOS" 2457 2458config PCI_GOMMCONFIG 2459 bool "MMConfig" 2460 2461config PCI_GODIRECT 2462 bool "Direct" 2463 2464config PCI_GOOLPC 2465 bool "OLPC XO-1" 2466 depends on OLPC 2467 2468config PCI_GOANY 2469 bool "Any" 2470 2471endchoice 2472 2473config PCI_BIOS 2474 def_bool y 2475 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2476 2477# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2478config PCI_DIRECT 2479 def_bool y 2480 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2481 2482config PCI_MMCONFIG 2483 def_bool y 2484 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2485 2486config PCI_OLPC 2487 def_bool y 2488 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2489 2490config PCI_XEN 2491 def_bool y 2492 depends on PCI && XEN 2493 select SWIOTLB_XEN 2494 2495config PCI_DOMAINS 2496 def_bool y 2497 depends on PCI 2498 2499config PCI_MMCONFIG 2500 bool "Support mmconfig PCI config space access" 2501 depends on X86_64 && PCI && ACPI 2502 2503config PCI_CNB20LE_QUIRK 2504 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2505 depends on PCI 2506 help 2507 Read the PCI windows out of the CNB20LE host bridge. This allows 2508 PCI hotplug to work on systems with the CNB20LE chipset which do 2509 not have ACPI. 2510 2511 There's no public spec for this chipset, and this functionality 2512 is known to be incomplete. 2513 2514 You should say N unless you know you need this. 2515 2516source "drivers/pci/Kconfig" 2517 2518config ISA_BUS 2519 bool "ISA-style bus support on modern systems" if EXPERT 2520 select ISA_BUS_API 2521 help 2522 Enables ISA-style drivers on modern systems. This is necessary to 2523 support PC/104 devices on X86_64 platforms. 2524 2525 If unsure, say N. 2526 2527# x86_64 have no ISA slots, but can have ISA-style DMA. 2528config ISA_DMA_API 2529 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2530 default y 2531 help 2532 Enables ISA-style DMA support for devices requiring such controllers. 2533 If unsure, say Y. 2534 2535if X86_32 2536 2537config ISA 2538 bool "ISA support" 2539 ---help--- 2540 Find out whether you have ISA slots on your motherboard. ISA is the 2541 name of a bus system, i.e. the way the CPU talks to the other stuff 2542 inside your box. Other bus systems are PCI, EISA, MicroChannel 2543 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2544 newer boards don't support it. If you have ISA, say Y, otherwise N. 2545 2546config EISA 2547 bool "EISA support" 2548 depends on ISA 2549 ---help--- 2550 The Extended Industry Standard Architecture (EISA) bus was 2551 developed as an open alternative to the IBM MicroChannel bus. 2552 2553 The EISA bus provided some of the features of the IBM MicroChannel 2554 bus while maintaining backward compatibility with cards made for 2555 the older ISA bus. The EISA bus saw limited use between 1988 and 2556 1995 when it was made obsolete by the PCI bus. 2557 2558 Say Y here if you are building a kernel for an EISA-based machine. 2559 2560 Otherwise, say N. 2561 2562source "drivers/eisa/Kconfig" 2563 2564config SCx200 2565 tristate "NatSemi SCx200 support" 2566 ---help--- 2567 This provides basic support for National Semiconductor's 2568 (now AMD's) Geode processors. The driver probes for the 2569 PCI-IDs of several on-chip devices, so its a good dependency 2570 for other scx200_* drivers. 2571 2572 If compiled as a module, the driver is named scx200. 2573 2574config SCx200HR_TIMER 2575 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2576 depends on SCx200 2577 default y 2578 ---help--- 2579 This driver provides a clocksource built upon the on-chip 2580 27MHz high-resolution timer. Its also a workaround for 2581 NSC Geode SC-1100's buggy TSC, which loses time when the 2582 processor goes idle (as is done by the scheduler). The 2583 other workaround is idle=poll boot option. 2584 2585config OLPC 2586 bool "One Laptop Per Child support" 2587 depends on !X86_PAE 2588 select GPIOLIB 2589 select OF 2590 select OF_PROMTREE 2591 select IRQ_DOMAIN 2592 ---help--- 2593 Add support for detecting the unique features of the OLPC 2594 XO hardware. 2595 2596config OLPC_XO1_PM 2597 bool "OLPC XO-1 Power Management" 2598 depends on OLPC && MFD_CS5535 && PM_SLEEP 2599 select MFD_CORE 2600 ---help--- 2601 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2602 2603config OLPC_XO1_RTC 2604 bool "OLPC XO-1 Real Time Clock" 2605 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2606 ---help--- 2607 Add support for the XO-1 real time clock, which can be used as a 2608 programmable wakeup source. 2609 2610config OLPC_XO1_SCI 2611 bool "OLPC XO-1 SCI extras" 2612 depends on OLPC && OLPC_XO1_PM 2613 depends on INPUT=y 2614 select POWER_SUPPLY 2615 select GPIO_CS5535 2616 select MFD_CORE 2617 ---help--- 2618 Add support for SCI-based features of the OLPC XO-1 laptop: 2619 - EC-driven system wakeups 2620 - Power button 2621 - Ebook switch 2622 - Lid switch 2623 - AC adapter status updates 2624 - Battery status updates 2625 2626config OLPC_XO15_SCI 2627 bool "OLPC XO-1.5 SCI extras" 2628 depends on OLPC && ACPI 2629 select POWER_SUPPLY 2630 ---help--- 2631 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2632 - EC-driven system wakeups 2633 - AC adapter status updates 2634 - Battery status updates 2635 2636config ALIX 2637 bool "PCEngines ALIX System Support (LED setup)" 2638 select GPIOLIB 2639 ---help--- 2640 This option enables system support for the PCEngines ALIX. 2641 At present this just sets up LEDs for GPIO control on 2642 ALIX2/3/6 boards. However, other system specific setup should 2643 get added here. 2644 2645 Note: You must still enable the drivers for GPIO and LED support 2646 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2647 2648 Note: You have to set alix.force=1 for boards with Award BIOS. 2649 2650config NET5501 2651 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2652 select GPIOLIB 2653 ---help--- 2654 This option enables system support for the Soekris Engineering net5501. 2655 2656config GEOS 2657 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2658 select GPIOLIB 2659 depends on DMI 2660 ---help--- 2661 This option enables system support for the Traverse Technologies GEOS. 2662 2663config TS5500 2664 bool "Technologic Systems TS-5500 platform support" 2665 depends on MELAN 2666 select CHECK_SIGNATURE 2667 select NEW_LEDS 2668 select LEDS_CLASS 2669 ---help--- 2670 This option enables system support for the Technologic Systems TS-5500. 2671 2672endif # X86_32 2673 2674config AMD_NB 2675 def_bool y 2676 depends on CPU_SUP_AMD && PCI 2677 2678source "drivers/pcmcia/Kconfig" 2679 2680config RAPIDIO 2681 tristate "RapidIO support" 2682 depends on PCI 2683 default n 2684 help 2685 If enabled this option will include drivers and the core 2686 infrastructure code to support RapidIO interconnect devices. 2687 2688source "drivers/rapidio/Kconfig" 2689 2690config X86_SYSFB 2691 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2692 help 2693 Firmwares often provide initial graphics framebuffers so the BIOS, 2694 bootloader or kernel can show basic video-output during boot for 2695 user-guidance and debugging. Historically, x86 used the VESA BIOS 2696 Extensions and EFI-framebuffers for this, which are mostly limited 2697 to x86. 2698 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2699 framebuffers so the new generic system-framebuffer drivers can be 2700 used on x86. If the framebuffer is not compatible with the generic 2701 modes, it is adverticed as fallback platform framebuffer so legacy 2702 drivers like efifb, vesafb and uvesafb can pick it up. 2703 If this option is not selected, all system framebuffers are always 2704 marked as fallback platform framebuffers as usual. 2705 2706 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2707 not be able to pick up generic system framebuffers if this option 2708 is selected. You are highly encouraged to enable simplefb as 2709 replacement if you select this option. simplefb can correctly deal 2710 with generic system framebuffers. But you should still keep vesafb 2711 and others enabled as fallback if a system framebuffer is 2712 incompatible with simplefb. 2713 2714 If unsure, say Y. 2715 2716endmenu 2717 2718 2719menu "Executable file formats / Emulations" 2720 2721source "fs/Kconfig.binfmt" 2722 2723config IA32_EMULATION 2724 bool "IA32 Emulation" 2725 depends on X86_64 2726 select ARCH_WANT_OLD_COMPAT_IPC 2727 select BINFMT_ELF 2728 select COMPAT_BINFMT_ELF 2729 select COMPAT_OLD_SIGACTION 2730 ---help--- 2731 Include code to run legacy 32-bit programs under a 2732 64-bit kernel. You should likely turn this on, unless you're 2733 100% sure that you don't have any 32-bit programs left. 2734 2735config IA32_AOUT 2736 tristate "IA32 a.out support" 2737 depends on IA32_EMULATION 2738 ---help--- 2739 Support old a.out binaries in the 32bit emulation. 2740 2741config X86_X32 2742 bool "x32 ABI for 64-bit mode" 2743 depends on X86_64 2744 ---help--- 2745 Include code to run binaries for the x32 native 32-bit ABI 2746 for 64-bit processors. An x32 process gets access to the 2747 full 64-bit register file and wide data path while leaving 2748 pointers at 32 bits for smaller memory footprint. 2749 2750 You will need a recent binutils (2.22 or later) with 2751 elf32_x86_64 support enabled to compile a kernel with this 2752 option set. 2753 2754config COMPAT_32 2755 def_bool y 2756 depends on IA32_EMULATION || X86_32 2757 select HAVE_UID16 2758 select OLD_SIGSUSPEND3 2759 2760config COMPAT 2761 def_bool y 2762 depends on IA32_EMULATION || X86_X32 2763 2764if COMPAT 2765config COMPAT_FOR_U64_ALIGNMENT 2766 def_bool y 2767 2768config SYSVIPC_COMPAT 2769 def_bool y 2770 depends on SYSVIPC 2771 2772config KEYS_COMPAT 2773 def_bool y 2774 depends on KEYS 2775endif 2776 2777endmenu 2778 2779 2780config HAVE_ATOMIC_IOMAP 2781 def_bool y 2782 depends on X86_32 2783 2784config X86_DEV_DMA_OPS 2785 bool 2786 depends on X86_64 || STA2X11 2787 2788config X86_DMA_REMAP 2789 bool 2790 depends on STA2X11 2791 2792config PMC_ATOM 2793 def_bool y 2794 depends on PCI 2795 2796source "net/Kconfig" 2797 2798source "drivers/Kconfig" 2799 2800source "drivers/firmware/Kconfig" 2801 2802source "fs/Kconfig" 2803 2804source "arch/x86/Kconfig.debug" 2805 2806source "security/Kconfig" 2807 2808source "crypto/Kconfig" 2809 2810source "arch/x86/kvm/Kconfig" 2811 2812source "lib/Kconfig" 2813