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 if (MEMORY_ISOLATION && COMPACTION) || CMA 26 select ARCH_SUPPORTS_INT128 27 select ARCH_USE_CMPXCHG_LOCKREF 28 select HAVE_ARCH_SOFT_DIRTY 29 select MODULES_USE_ELF_RELA 30 select X86_DEV_DMA_OPS 31 32# 33# Arch settings 34# 35# ( Note that options that are marked 'if X86_64' could in principle be 36# ported to 32-bit as well. ) 37# 38config X86 39 def_bool y 40 # 41 # Note: keep this list sorted alphabetically 42 # 43 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 44 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 45 select ANON_INODES 46 select ARCH_CLOCKSOURCE_DATA 47 select ARCH_DISCARD_MEMBLOCK 48 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 49 select ARCH_HAS_DEBUG_VIRTUAL 50 select ARCH_HAS_DEVMEM_IS_ALLOWED 51 select ARCH_HAS_ELF_RANDOMIZE 52 select ARCH_HAS_FAST_MULTIPLIER 53 select ARCH_HAS_FORTIFY_SOURCE 54 select ARCH_HAS_GCOV_PROFILE_ALL 55 select ARCH_HAS_KCOV if X86_64 56 select ARCH_HAS_PMEM_API if X86_64 57 # Causing hangs/crashes, see the commit that added this change for details. 58 select ARCH_HAS_REFCOUNT if BROKEN 59 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 60 select ARCH_HAS_SET_MEMORY 61 select ARCH_HAS_SG_CHAIN 62 select ARCH_HAS_STRICT_KERNEL_RWX 63 select ARCH_HAS_STRICT_MODULE_RWX 64 select ARCH_HAS_UBSAN_SANITIZE_ALL 65 select ARCH_HAS_ZONE_DEVICE if X86_64 66 select ARCH_HAVE_NMI_SAFE_CMPXCHG 67 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 68 select ARCH_MIGHT_HAVE_PC_PARPORT 69 select ARCH_MIGHT_HAVE_PC_SERIO 70 select ARCH_SUPPORTS_ATOMIC_RMW 71 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 72 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 73 select ARCH_USE_BUILTIN_BSWAP 74 select ARCH_USE_QUEUED_RWLOCKS 75 select ARCH_USE_QUEUED_SPINLOCKS 76 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 77 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 78 select ARCH_WANTS_THP_SWAP if X86_64 79 select BUILDTIME_EXTABLE_SORT 80 select CLKEVT_I8253 81 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 82 select CLOCKSOURCE_WATCHDOG 83 select DCACHE_WORD_ACCESS 84 select EDAC_ATOMIC_SCRUB 85 select EDAC_SUPPORT 86 select GENERIC_CLOCKEVENTS 87 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 88 select GENERIC_CLOCKEVENTS_MIN_ADJUST 89 select GENERIC_CMOS_UPDATE 90 select GENERIC_CPU_AUTOPROBE 91 select GENERIC_EARLY_IOREMAP 92 select GENERIC_FIND_FIRST_BIT 93 select GENERIC_IOMAP 94 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 95 select GENERIC_IRQ_MIGRATION if SMP 96 select GENERIC_IRQ_PROBE 97 select GENERIC_IRQ_SHOW 98 select GENERIC_PENDING_IRQ if SMP 99 select GENERIC_SMP_IDLE_THREAD 100 select GENERIC_STRNCPY_FROM_USER 101 select GENERIC_STRNLEN_USER 102 select GENERIC_TIME_VSYSCALL 103 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 104 select HAVE_ACPI_APEI if ACPI 105 select HAVE_ACPI_APEI_NMI if ACPI 106 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 107 select HAVE_ARCH_AUDITSYSCALL 108 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 109 select HAVE_ARCH_JUMP_LABEL 110 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 111 select HAVE_ARCH_KGDB 112 select HAVE_ARCH_KMEMCHECK 113 select HAVE_ARCH_MMAP_RND_BITS if MMU 114 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 115 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 116 select HAVE_ARCH_SECCOMP_FILTER 117 select HAVE_ARCH_TRACEHOOK 118 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 119 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 120 select HAVE_ARCH_VMAP_STACK if X86_64 121 select HAVE_ARCH_WITHIN_STACK_FRAMES 122 select HAVE_CC_STACKPROTECTOR 123 select HAVE_CMPXCHG_DOUBLE 124 select HAVE_CMPXCHG_LOCAL 125 select HAVE_CONTEXT_TRACKING if X86_64 126 select HAVE_COPY_THREAD_TLS 127 select HAVE_C_RECORDMCOUNT 128 select HAVE_DEBUG_KMEMLEAK 129 select HAVE_DEBUG_STACKOVERFLOW 130 select HAVE_DMA_API_DEBUG 131 select HAVE_DMA_CONTIGUOUS 132 select HAVE_DYNAMIC_FTRACE 133 select HAVE_DYNAMIC_FTRACE_WITH_REGS 134 select HAVE_EBPF_JIT if X86_64 135 select HAVE_EFFICIENT_UNALIGNED_ACCESS 136 select HAVE_EXIT_THREAD 137 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 138 select HAVE_FTRACE_MCOUNT_RECORD 139 select HAVE_FUNCTION_GRAPH_TRACER 140 select HAVE_FUNCTION_TRACER 141 select HAVE_GCC_PLUGINS 142 select HAVE_HW_BREAKPOINT 143 select HAVE_IDE 144 select HAVE_IOREMAP_PROT 145 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 146 select HAVE_IRQ_TIME_ACCOUNTING 147 select HAVE_KERNEL_BZIP2 148 select HAVE_KERNEL_GZIP 149 select HAVE_KERNEL_LZ4 150 select HAVE_KERNEL_LZMA 151 select HAVE_KERNEL_LZO 152 select HAVE_KERNEL_XZ 153 select HAVE_KPROBES 154 select HAVE_KPROBES_ON_FTRACE 155 select HAVE_KRETPROBES 156 select HAVE_KVM 157 select HAVE_LIVEPATCH if X86_64 158 select HAVE_MEMBLOCK 159 select HAVE_MEMBLOCK_NODE_MAP 160 select HAVE_MIXED_BREAKPOINTS_REGS 161 select HAVE_MOD_ARCH_SPECIFIC 162 select HAVE_NMI 163 select HAVE_OPROFILE 164 select HAVE_OPTPROBES 165 select HAVE_PCSPKR_PLATFORM 166 select HAVE_PERF_EVENTS 167 select HAVE_PERF_EVENTS_NMI 168 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 169 select HAVE_PERF_REGS 170 select HAVE_PERF_USER_STACK_DUMP 171 select HAVE_RCU_TABLE_FREE 172 select HAVE_REGS_AND_STACK_ACCESS_API 173 select HAVE_RELIABLE_STACKTRACE if X86_64 && FRAME_POINTER_UNWINDER && STACK_VALIDATION 174 select HAVE_STACK_VALIDATION if X86_64 175 select HAVE_SYSCALL_TRACEPOINTS 176 select HAVE_UNSTABLE_SCHED_CLOCK 177 select HAVE_USER_RETURN_NOTIFIER 178 select IRQ_FORCED_THREADING 179 select PCI_LOCKLESS_CONFIG 180 select PERF_EVENTS 181 select RTC_LIB 182 select RTC_MC146818_LIB 183 select SPARSE_IRQ 184 select SRCU 185 select SYSCTL_EXCEPTION_TRACE 186 select THREAD_INFO_IN_TASK 187 select USER_STACKTRACE_SUPPORT 188 select VIRT_TO_BUS 189 select X86_FEATURE_NAMES if PROC_FS 190 191config INSTRUCTION_DECODER 192 def_bool y 193 depends on KPROBES || PERF_EVENTS || UPROBES 194 195config OUTPUT_FORMAT 196 string 197 default "elf32-i386" if X86_32 198 default "elf64-x86-64" if X86_64 199 200config ARCH_DEFCONFIG 201 string 202 default "arch/x86/configs/i386_defconfig" if X86_32 203 default "arch/x86/configs/x86_64_defconfig" if X86_64 204 205config LOCKDEP_SUPPORT 206 def_bool y 207 208config STACKTRACE_SUPPORT 209 def_bool y 210 211config MMU 212 def_bool y 213 214config ARCH_MMAP_RND_BITS_MIN 215 default 28 if 64BIT 216 default 8 217 218config ARCH_MMAP_RND_BITS_MAX 219 default 32 if 64BIT 220 default 16 221 222config ARCH_MMAP_RND_COMPAT_BITS_MIN 223 default 8 224 225config ARCH_MMAP_RND_COMPAT_BITS_MAX 226 default 16 227 228config SBUS 229 bool 230 231config NEED_DMA_MAP_STATE 232 def_bool y 233 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 234 235config NEED_SG_DMA_LENGTH 236 def_bool y 237 238config GENERIC_ISA_DMA 239 def_bool y 240 depends on ISA_DMA_API 241 242config GENERIC_BUG 243 def_bool y 244 depends on BUG 245 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 246 247config GENERIC_BUG_RELATIVE_POINTERS 248 bool 249 250config GENERIC_HWEIGHT 251 def_bool y 252 253config ARCH_MAY_HAVE_PC_FDC 254 def_bool y 255 depends on ISA_DMA_API 256 257config RWSEM_XCHGADD_ALGORITHM 258 def_bool y 259 260config GENERIC_CALIBRATE_DELAY 261 def_bool y 262 263config ARCH_HAS_CPU_RELAX 264 def_bool y 265 266config ARCH_HAS_CACHE_LINE_SIZE 267 def_bool y 268 269config HAVE_SETUP_PER_CPU_AREA 270 def_bool y 271 272config NEED_PER_CPU_EMBED_FIRST_CHUNK 273 def_bool y 274 275config NEED_PER_CPU_PAGE_FIRST_CHUNK 276 def_bool y 277 278config ARCH_HIBERNATION_POSSIBLE 279 def_bool y 280 281config ARCH_SUSPEND_POSSIBLE 282 def_bool y 283 284config ARCH_WANT_HUGE_PMD_SHARE 285 def_bool y 286 287config ARCH_WANT_GENERAL_HUGETLB 288 def_bool y 289 290config ZONE_DMA32 291 def_bool y if X86_64 292 293config AUDIT_ARCH 294 def_bool y if X86_64 295 296config ARCH_SUPPORTS_OPTIMIZED_INLINING 297 def_bool y 298 299config ARCH_SUPPORTS_DEBUG_PAGEALLOC 300 def_bool y 301 302config KASAN_SHADOW_OFFSET 303 hex 304 depends on KASAN 305 default 0xdff8000000000000 if X86_5LEVEL 306 default 0xdffffc0000000000 307 308config HAVE_INTEL_TXT 309 def_bool y 310 depends on INTEL_IOMMU && ACPI 311 312config X86_32_SMP 313 def_bool y 314 depends on X86_32 && SMP 315 316config X86_64_SMP 317 def_bool y 318 depends on X86_64 && SMP 319 320config X86_32_LAZY_GS 321 def_bool y 322 depends on X86_32 && !CC_STACKPROTECTOR 323 324config ARCH_SUPPORTS_UPROBES 325 def_bool y 326 327config FIX_EARLYCON_MEM 328 def_bool y 329 330config PGTABLE_LEVELS 331 int 332 default 5 if X86_5LEVEL 333 default 4 if X86_64 334 default 3 if X86_PAE 335 default 2 336 337source "init/Kconfig" 338source "kernel/Kconfig.freezer" 339 340menu "Processor type and features" 341 342config ZONE_DMA 343 bool "DMA memory allocation support" if EXPERT 344 default y 345 help 346 DMA memory allocation support allows devices with less than 32-bit 347 addressing to allocate within the first 16MB of address space. 348 Disable if no such devices will be used. 349 350 If unsure, say Y. 351 352config SMP 353 bool "Symmetric multi-processing support" 354 ---help--- 355 This enables support for systems with more than one CPU. If you have 356 a system with only one CPU, say N. If you have a system with more 357 than one CPU, say Y. 358 359 If you say N here, the kernel will run on uni- and multiprocessor 360 machines, but will use only one CPU of a multiprocessor machine. If 361 you say Y here, the kernel will run on many, but not all, 362 uniprocessor machines. On a uniprocessor machine, the kernel 363 will run faster if you say N here. 364 365 Note that if you say Y here and choose architecture "586" or 366 "Pentium" under "Processor family", the kernel will not work on 486 367 architectures. Similarly, multiprocessor kernels for the "PPro" 368 architecture may not work on all Pentium based boards. 369 370 People using multiprocessor machines who say Y here should also say 371 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 372 Management" code will be disabled if you say Y here. 373 374 See also <file:Documentation/x86/i386/IO-APIC.txt>, 375 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 376 <http://www.tldp.org/docs.html#howto>. 377 378 If you don't know what to do here, say N. 379 380config X86_FEATURE_NAMES 381 bool "Processor feature human-readable names" if EMBEDDED 382 default y 383 ---help--- 384 This option compiles in a table of x86 feature bits and corresponding 385 names. This is required to support /proc/cpuinfo and a few kernel 386 messages. You can disable this to save space, at the expense of 387 making those few kernel messages show numeric feature bits instead. 388 389 If in doubt, say Y. 390 391config X86_FAST_FEATURE_TESTS 392 bool "Fast CPU feature tests" if EMBEDDED 393 default y 394 ---help--- 395 Some fast-paths in the kernel depend on the capabilities of the CPU. 396 Say Y here for the kernel to patch in the appropriate code at runtime 397 based on the capabilities of the CPU. The infrastructure for patching 398 code at runtime takes up some additional space; space-constrained 399 embedded systems may wish to say N here to produce smaller, slightly 400 slower code. 401 402config X86_X2APIC 403 bool "Support x2apic" 404 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 405 ---help--- 406 This enables x2apic support on CPUs that have this feature. 407 408 This allows 32-bit apic IDs (so it can support very large systems), 409 and accesses the local apic via MSRs not via mmio. 410 411 If you don't know what to do here, say N. 412 413config X86_MPPARSE 414 bool "Enable MPS table" if ACPI || SFI 415 default y 416 depends on X86_LOCAL_APIC 417 ---help--- 418 For old smp systems that do not have proper acpi support. Newer systems 419 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 420 421config X86_BIGSMP 422 bool "Support for big SMP systems with more than 8 CPUs" 423 depends on X86_32 && SMP 424 ---help--- 425 This option is needed for the systems that have more than 8 CPUs 426 427config GOLDFISH 428 def_bool y 429 depends on X86_GOLDFISH 430 431config INTEL_RDT 432 bool "Intel Resource Director Technology support" 433 default n 434 depends on X86 && CPU_SUP_INTEL 435 select KERNFS 436 help 437 Select to enable resource allocation and monitoring which are 438 sub-features of Intel Resource Director Technology(RDT). More 439 information about RDT can be found in the Intel x86 440 Architecture Software Developer Manual. 441 442 Say N if unsure. 443 444if X86_32 445config X86_EXTENDED_PLATFORM 446 bool "Support for extended (non-PC) x86 platforms" 447 default y 448 ---help--- 449 If you disable this option then the kernel will only support 450 standard PC platforms. (which covers the vast majority of 451 systems out there.) 452 453 If you enable this option then you'll be able to select support 454 for the following (non-PC) 32 bit x86 platforms: 455 Goldfish (Android emulator) 456 AMD Elan 457 RDC R-321x SoC 458 SGI 320/540 (Visual Workstation) 459 STA2X11-based (e.g. Northville) 460 Moorestown MID devices 461 462 If you have one of these systems, or if you want to build a 463 generic distribution kernel, say Y here - otherwise say N. 464endif 465 466if X86_64 467config X86_EXTENDED_PLATFORM 468 bool "Support for extended (non-PC) x86 platforms" 469 default y 470 ---help--- 471 If you disable this option then the kernel will only support 472 standard PC platforms. (which covers the vast majority of 473 systems out there.) 474 475 If you enable this option then you'll be able to select support 476 for the following (non-PC) 64 bit x86 platforms: 477 Numascale NumaChip 478 ScaleMP vSMP 479 SGI Ultraviolet 480 481 If you have one of these systems, or if you want to build a 482 generic distribution kernel, say Y here - otherwise say N. 483endif 484# This is an alphabetically sorted list of 64 bit extended platforms 485# Please maintain the alphabetic order if and when there are additions 486config X86_NUMACHIP 487 bool "Numascale NumaChip" 488 depends on X86_64 489 depends on X86_EXTENDED_PLATFORM 490 depends on NUMA 491 depends on SMP 492 depends on X86_X2APIC 493 depends on PCI_MMCONFIG 494 ---help--- 495 Adds support for Numascale NumaChip large-SMP systems. Needed to 496 enable more than ~168 cores. 497 If you don't have one of these, you should say N here. 498 499config X86_VSMP 500 bool "ScaleMP vSMP" 501 select HYPERVISOR_GUEST 502 select PARAVIRT 503 depends on X86_64 && PCI 504 depends on X86_EXTENDED_PLATFORM 505 depends on SMP 506 ---help--- 507 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 508 supposed to run on these EM64T-based machines. Only choose this option 509 if you have one of these machines. 510 511config X86_UV 512 bool "SGI Ultraviolet" 513 depends on X86_64 514 depends on X86_EXTENDED_PLATFORM 515 depends on NUMA 516 depends on EFI 517 depends on X86_X2APIC 518 depends on PCI 519 ---help--- 520 This option is needed in order to support SGI Ultraviolet systems. 521 If you don't have one of these, you should say N here. 522 523# Following is an alphabetically sorted list of 32 bit extended platforms 524# Please maintain the alphabetic order if and when there are additions 525 526config X86_GOLDFISH 527 bool "Goldfish (Virtual Platform)" 528 depends on X86_EXTENDED_PLATFORM 529 ---help--- 530 Enable support for the Goldfish virtual platform used primarily 531 for Android development. Unless you are building for the Android 532 Goldfish emulator say N here. 533 534config X86_INTEL_CE 535 bool "CE4100 TV platform" 536 depends on PCI 537 depends on PCI_GODIRECT 538 depends on X86_IO_APIC 539 depends on X86_32 540 depends on X86_EXTENDED_PLATFORM 541 select X86_REBOOTFIXUPS 542 select OF 543 select OF_EARLY_FLATTREE 544 ---help--- 545 Select for the Intel CE media processor (CE4100) SOC. 546 This option compiles in support for the CE4100 SOC for settop 547 boxes and media devices. 548 549config X86_INTEL_MID 550 bool "Intel MID platform support" 551 depends on X86_EXTENDED_PLATFORM 552 depends on X86_PLATFORM_DEVICES 553 depends on PCI 554 depends on X86_64 || (PCI_GOANY && X86_32) 555 depends on X86_IO_APIC 556 select SFI 557 select I2C 558 select DW_APB_TIMER 559 select APB_TIMER 560 select INTEL_SCU_IPC 561 select MFD_INTEL_MSIC 562 ---help--- 563 Select to build a kernel capable of supporting Intel MID (Mobile 564 Internet Device) platform systems which do not have the PCI legacy 565 interfaces. If you are building for a PC class system say N here. 566 567 Intel MID platforms are based on an Intel processor and chipset which 568 consume less power than most of the x86 derivatives. 569 570config X86_INTEL_QUARK 571 bool "Intel Quark platform support" 572 depends on X86_32 573 depends on X86_EXTENDED_PLATFORM 574 depends on X86_PLATFORM_DEVICES 575 depends on X86_TSC 576 depends on PCI 577 depends on PCI_GOANY 578 depends on X86_IO_APIC 579 select IOSF_MBI 580 select INTEL_IMR 581 select COMMON_CLK 582 ---help--- 583 Select to include support for Quark X1000 SoC. 584 Say Y here if you have a Quark based system such as the Arduino 585 compatible Intel Galileo. 586 587config X86_INTEL_LPSS 588 bool "Intel Low Power Subsystem Support" 589 depends on X86 && ACPI 590 select COMMON_CLK 591 select PINCTRL 592 select IOSF_MBI 593 ---help--- 594 Select to build support for Intel Low Power Subsystem such as 595 found on Intel Lynxpoint PCH. Selecting this option enables 596 things like clock tree (common clock framework) and pincontrol 597 which are needed by the LPSS peripheral drivers. 598 599config X86_AMD_PLATFORM_DEVICE 600 bool "AMD ACPI2Platform devices support" 601 depends on ACPI 602 select COMMON_CLK 603 select PINCTRL 604 ---help--- 605 Select to interpret AMD specific ACPI device to platform device 606 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 607 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 608 implemented under PINCTRL subsystem. 609 610config IOSF_MBI 611 tristate "Intel SoC IOSF Sideband support for SoC platforms" 612 depends on PCI 613 ---help--- 614 This option enables sideband register access support for Intel SoC 615 platforms. On these platforms the IOSF sideband is used in lieu of 616 MSR's for some register accesses, mostly but not limited to thermal 617 and power. Drivers may query the availability of this device to 618 determine if they need the sideband in order to work on these 619 platforms. The sideband is available on the following SoC products. 620 This list is not meant to be exclusive. 621 - BayTrail 622 - Braswell 623 - Quark 624 625 You should say Y if you are running a kernel on one of these SoC's. 626 627config IOSF_MBI_DEBUG 628 bool "Enable IOSF sideband access through debugfs" 629 depends on IOSF_MBI && DEBUG_FS 630 ---help--- 631 Select this option to expose the IOSF sideband access registers (MCR, 632 MDR, MCRX) through debugfs to write and read register information from 633 different units on the SoC. This is most useful for obtaining device 634 state information for debug and analysis. As this is a general access 635 mechanism, users of this option would have specific knowledge of the 636 device they want to access. 637 638 If you don't require the option or are in doubt, say N. 639 640config X86_RDC321X 641 bool "RDC R-321x SoC" 642 depends on X86_32 643 depends on X86_EXTENDED_PLATFORM 644 select M486 645 select X86_REBOOTFIXUPS 646 ---help--- 647 This option is needed for RDC R-321x system-on-chip, also known 648 as R-8610-(G). 649 If you don't have one of these chips, you should say N here. 650 651config X86_32_NON_STANDARD 652 bool "Support non-standard 32-bit SMP architectures" 653 depends on X86_32 && SMP 654 depends on X86_EXTENDED_PLATFORM 655 ---help--- 656 This option compiles in the bigsmp and STA2X11 default 657 subarchitectures. It is intended for a generic binary 658 kernel. If you select them all, kernel will probe it one by 659 one and will fallback to default. 660 661# Alphabetically sorted list of Non standard 32 bit platforms 662 663config X86_SUPPORTS_MEMORY_FAILURE 664 def_bool y 665 # MCE code calls memory_failure(): 666 depends on X86_MCE 667 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 668 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 669 depends on X86_64 || !SPARSEMEM 670 select ARCH_SUPPORTS_MEMORY_FAILURE 671 672config STA2X11 673 bool "STA2X11 Companion Chip Support" 674 depends on X86_32_NON_STANDARD && PCI 675 select X86_DEV_DMA_OPS 676 select X86_DMA_REMAP 677 select SWIOTLB 678 select MFD_STA2X11 679 select GPIOLIB 680 default n 681 ---help--- 682 This adds support for boards based on the STA2X11 IO-Hub, 683 a.k.a. "ConneXt". The chip is used in place of the standard 684 PC chipset, so all "standard" peripherals are missing. If this 685 option is selected the kernel will still be able to boot on 686 standard PC machines. 687 688config X86_32_IRIS 689 tristate "Eurobraille/Iris poweroff module" 690 depends on X86_32 691 ---help--- 692 The Iris machines from EuroBraille do not have APM or ACPI support 693 to shut themselves down properly. A special I/O sequence is 694 needed to do so, which is what this module does at 695 kernel shutdown. 696 697 This is only for Iris machines from EuroBraille. 698 699 If unused, say N. 700 701config SCHED_OMIT_FRAME_POINTER 702 def_bool y 703 prompt "Single-depth WCHAN output" 704 depends on X86 705 ---help--- 706 Calculate simpler /proc/<PID>/wchan values. If this option 707 is disabled then wchan values will recurse back to the 708 caller function. This provides more accurate wchan values, 709 at the expense of slightly more scheduling overhead. 710 711 If in doubt, say "Y". 712 713menuconfig HYPERVISOR_GUEST 714 bool "Linux guest support" 715 ---help--- 716 Say Y here to enable options for running Linux under various hyper- 717 visors. This option enables basic hypervisor detection and platform 718 setup. 719 720 If you say N, all options in this submenu will be skipped and 721 disabled, and Linux guest support won't be built in. 722 723if HYPERVISOR_GUEST 724 725config PARAVIRT 726 bool "Enable paravirtualization code" 727 ---help--- 728 This changes the kernel so it can modify itself when it is run 729 under a hypervisor, potentially improving performance significantly 730 over full virtualization. However, when run without a hypervisor 731 the kernel is theoretically slower and slightly larger. 732 733config PARAVIRT_DEBUG 734 bool "paravirt-ops debugging" 735 depends on PARAVIRT && DEBUG_KERNEL 736 ---help--- 737 Enable to debug paravirt_ops internals. Specifically, BUG if 738 a paravirt_op is missing when it is called. 739 740config PARAVIRT_SPINLOCKS 741 bool "Paravirtualization layer for spinlocks" 742 depends on PARAVIRT && SMP 743 ---help--- 744 Paravirtualized spinlocks allow a pvops backend to replace the 745 spinlock implementation with something virtualization-friendly 746 (for example, block the virtual CPU rather than spinning). 747 748 It has a minimal impact on native kernels and gives a nice performance 749 benefit on paravirtualized KVM / Xen kernels. 750 751 If you are unsure how to answer this question, answer Y. 752 753config QUEUED_LOCK_STAT 754 bool "Paravirt queued spinlock statistics" 755 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 756 ---help--- 757 Enable the collection of statistical data on the slowpath 758 behavior of paravirtualized queued spinlocks and report 759 them on debugfs. 760 761source "arch/x86/xen/Kconfig" 762 763config KVM_GUEST 764 bool "KVM Guest support (including kvmclock)" 765 depends on PARAVIRT 766 select PARAVIRT_CLOCK 767 default y 768 ---help--- 769 This option enables various optimizations for running under the KVM 770 hypervisor. It includes a paravirtualized clock, so that instead 771 of relying on a PIT (or probably other) emulation by the 772 underlying device model, the host provides the guest with 773 timing infrastructure such as time of day, and system time 774 775config KVM_DEBUG_FS 776 bool "Enable debug information for KVM Guests in debugfs" 777 depends on KVM_GUEST && DEBUG_FS 778 default n 779 ---help--- 780 This option enables collection of various statistics for KVM guest. 781 Statistics are displayed in debugfs filesystem. Enabling this option 782 may incur significant overhead. 783 784config PARAVIRT_TIME_ACCOUNTING 785 bool "Paravirtual steal time accounting" 786 depends on PARAVIRT 787 default n 788 ---help--- 789 Select this option to enable fine granularity task steal time 790 accounting. Time spent executing other tasks in parallel with 791 the current vCPU is discounted from the vCPU power. To account for 792 that, there can be a small performance impact. 793 794 If in doubt, say N here. 795 796config PARAVIRT_CLOCK 797 bool 798 799endif #HYPERVISOR_GUEST 800 801config NO_BOOTMEM 802 def_bool y 803 804source "arch/x86/Kconfig.cpu" 805 806config HPET_TIMER 807 def_bool X86_64 808 prompt "HPET Timer Support" if X86_32 809 ---help--- 810 Use the IA-PC HPET (High Precision Event Timer) to manage 811 time in preference to the PIT and RTC, if a HPET is 812 present. 813 HPET is the next generation timer replacing legacy 8254s. 814 The HPET provides a stable time base on SMP 815 systems, unlike the TSC, but it is more expensive to access, 816 as it is off-chip. The interface used is documented 817 in the HPET spec, revision 1. 818 819 You can safely choose Y here. However, HPET will only be 820 activated if the platform and the BIOS support this feature. 821 Otherwise the 8254 will be used for timing services. 822 823 Choose N to continue using the legacy 8254 timer. 824 825config HPET_EMULATE_RTC 826 def_bool y 827 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 828 829config APB_TIMER 830 def_bool y if X86_INTEL_MID 831 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 832 select DW_APB_TIMER 833 depends on X86_INTEL_MID && SFI 834 help 835 APB timer is the replacement for 8254, HPET on X86 MID platforms. 836 The APBT provides a stable time base on SMP 837 systems, unlike the TSC, but it is more expensive to access, 838 as it is off-chip. APB timers are always running regardless of CPU 839 C states, they are used as per CPU clockevent device when possible. 840 841# Mark as expert because too many people got it wrong. 842# The code disables itself when not needed. 843config DMI 844 default y 845 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 846 bool "Enable DMI scanning" if EXPERT 847 ---help--- 848 Enabled scanning of DMI to identify machine quirks. Say Y 849 here unless you have verified that your setup is not 850 affected by entries in the DMI blacklist. Required by PNP 851 BIOS code. 852 853config GART_IOMMU 854 bool "Old AMD GART IOMMU support" 855 select SWIOTLB 856 depends on X86_64 && PCI && AMD_NB 857 ---help--- 858 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 859 GART based hardware IOMMUs. 860 861 The GART supports full DMA access for devices with 32-bit access 862 limitations, on systems with more than 3 GB. This is usually needed 863 for USB, sound, many IDE/SATA chipsets and some other devices. 864 865 Newer systems typically have a modern AMD IOMMU, supported via 866 the CONFIG_AMD_IOMMU=y config option. 867 868 In normal configurations this driver is only active when needed: 869 there's more than 3 GB of memory and the system contains a 870 32-bit limited device. 871 872 If unsure, say Y. 873 874config CALGARY_IOMMU 875 bool "IBM Calgary IOMMU support" 876 select SWIOTLB 877 depends on X86_64 && PCI 878 ---help--- 879 Support for hardware IOMMUs in IBM's xSeries x366 and x460 880 systems. Needed to run systems with more than 3GB of memory 881 properly with 32-bit PCI devices that do not support DAC 882 (Double Address Cycle). Calgary also supports bus level 883 isolation, where all DMAs pass through the IOMMU. This 884 prevents them from going anywhere except their intended 885 destination. This catches hard-to-find kernel bugs and 886 mis-behaving drivers and devices that do not use the DMA-API 887 properly to set up their DMA buffers. The IOMMU can be 888 turned off at boot time with the iommu=off parameter. 889 Normally the kernel will make the right choice by itself. 890 If unsure, say Y. 891 892config CALGARY_IOMMU_ENABLED_BY_DEFAULT 893 def_bool y 894 prompt "Should Calgary be enabled by default?" 895 depends on CALGARY_IOMMU 896 ---help--- 897 Should Calgary be enabled by default? if you choose 'y', Calgary 898 will be used (if it exists). If you choose 'n', Calgary will not be 899 used even if it exists. If you choose 'n' and would like to use 900 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 901 If unsure, say Y. 902 903# need this always selected by IOMMU for the VIA workaround 904config SWIOTLB 905 def_bool y if X86_64 906 ---help--- 907 Support for software bounce buffers used on x86-64 systems 908 which don't have a hardware IOMMU. Using this PCI devices 909 which can only access 32-bits of memory can be used on systems 910 with more than 3 GB of memory. 911 If unsure, say Y. 912 913config IOMMU_HELPER 914 def_bool y 915 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 916 917config MAXSMP 918 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 919 depends on X86_64 && SMP && DEBUG_KERNEL 920 select CPUMASK_OFFSTACK 921 ---help--- 922 Enable maximum number of CPUS and NUMA Nodes for this architecture. 923 If unsure, say N. 924 925config NR_CPUS 926 int "Maximum number of CPUs" if SMP && !MAXSMP 927 range 2 8 if SMP && X86_32 && !X86_BIGSMP 928 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 929 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 930 default "1" if !SMP 931 default "8192" if MAXSMP 932 default "32" if SMP && X86_BIGSMP 933 default "8" if SMP && X86_32 934 default "64" if SMP 935 ---help--- 936 This allows you to specify the maximum number of CPUs which this 937 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 938 supported value is 8192, otherwise the maximum value is 512. The 939 minimum value which makes sense is 2. 940 941 This is purely to save memory - each supported CPU adds 942 approximately eight kilobytes to the kernel image. 943 944config SCHED_SMT 945 bool "SMT (Hyperthreading) scheduler support" 946 depends on SMP 947 ---help--- 948 SMT scheduler support improves the CPU scheduler's decision making 949 when dealing with Intel Pentium 4 chips with HyperThreading at a 950 cost of slightly increased overhead in some places. If unsure say 951 N here. 952 953config SCHED_MC 954 def_bool y 955 prompt "Multi-core scheduler support" 956 depends on SMP 957 ---help--- 958 Multi-core scheduler support improves the CPU scheduler's decision 959 making when dealing with multi-core CPU chips at a cost of slightly 960 increased overhead in some places. If unsure say N here. 961 962config SCHED_MC_PRIO 963 bool "CPU core priorities scheduler support" 964 depends on SCHED_MC && CPU_SUP_INTEL 965 select X86_INTEL_PSTATE 966 select CPU_FREQ 967 default y 968 ---help--- 969 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 970 core ordering determined at manufacturing time, which allows 971 certain cores to reach higher turbo frequencies (when running 972 single threaded workloads) than others. 973 974 Enabling this kernel feature teaches the scheduler about 975 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 976 scheduler's CPU selection logic accordingly, so that higher 977 overall system performance can be achieved. 978 979 This feature will have no effect on CPUs without this feature. 980 981 If unsure say Y here. 982 983source "kernel/Kconfig.preempt" 984 985config UP_LATE_INIT 986 def_bool y 987 depends on !SMP && X86_LOCAL_APIC 988 989config X86_UP_APIC 990 bool "Local APIC support on uniprocessors" if !PCI_MSI 991 default PCI_MSI 992 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 993 ---help--- 994 A local APIC (Advanced Programmable Interrupt Controller) is an 995 integrated interrupt controller in the CPU. If you have a single-CPU 996 system which has a processor with a local APIC, you can say Y here to 997 enable and use it. If you say Y here even though your machine doesn't 998 have a local APIC, then the kernel will still run with no slowdown at 999 all. The local APIC supports CPU-generated self-interrupts (timer, 1000 performance counters), and the NMI watchdog which detects hard 1001 lockups. 1002 1003config X86_UP_IOAPIC 1004 bool "IO-APIC support on uniprocessors" 1005 depends on X86_UP_APIC 1006 ---help--- 1007 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1008 SMP-capable replacement for PC-style interrupt controllers. Most 1009 SMP systems and many recent uniprocessor systems have one. 1010 1011 If you have a single-CPU system with an IO-APIC, you can say Y here 1012 to use it. If you say Y here even though your machine doesn't have 1013 an IO-APIC, then the kernel will still run with no slowdown at all. 1014 1015config X86_LOCAL_APIC 1016 def_bool y 1017 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1018 select IRQ_DOMAIN_HIERARCHY 1019 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1020 1021config X86_IO_APIC 1022 def_bool y 1023 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1024 1025config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1026 bool "Reroute for broken boot IRQs" 1027 depends on X86_IO_APIC 1028 ---help--- 1029 This option enables a workaround that fixes a source of 1030 spurious interrupts. This is recommended when threaded 1031 interrupt handling is used on systems where the generation of 1032 superfluous "boot interrupts" cannot be disabled. 1033 1034 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1035 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1036 kernel does during interrupt handling). On chipsets where this 1037 boot IRQ generation cannot be disabled, this workaround keeps 1038 the original IRQ line masked so that only the equivalent "boot 1039 IRQ" is delivered to the CPUs. The workaround also tells the 1040 kernel to set up the IRQ handler on the boot IRQ line. In this 1041 way only one interrupt is delivered to the kernel. Otherwise 1042 the spurious second interrupt may cause the kernel to bring 1043 down (vital) interrupt lines. 1044 1045 Only affects "broken" chipsets. Interrupt sharing may be 1046 increased on these systems. 1047 1048config X86_MCE 1049 bool "Machine Check / overheating reporting" 1050 select GENERIC_ALLOCATOR 1051 default y 1052 ---help--- 1053 Machine Check support allows the processor to notify the 1054 kernel if it detects a problem (e.g. overheating, data corruption). 1055 The action the kernel takes depends on the severity of the problem, 1056 ranging from warning messages to halting the machine. 1057 1058config X86_MCELOG_LEGACY 1059 bool "Support for deprecated /dev/mcelog character device" 1060 depends on X86_MCE 1061 ---help--- 1062 Enable support for /dev/mcelog which is needed by the old mcelog 1063 userspace logging daemon. Consider switching to the new generation 1064 rasdaemon solution. 1065 1066config X86_MCE_INTEL 1067 def_bool y 1068 prompt "Intel MCE features" 1069 depends on X86_MCE && X86_LOCAL_APIC 1070 ---help--- 1071 Additional support for intel specific MCE features such as 1072 the thermal monitor. 1073 1074config X86_MCE_AMD 1075 def_bool y 1076 prompt "AMD MCE features" 1077 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1078 ---help--- 1079 Additional support for AMD specific MCE features such as 1080 the DRAM Error Threshold. 1081 1082config X86_ANCIENT_MCE 1083 bool "Support for old Pentium 5 / WinChip machine checks" 1084 depends on X86_32 && X86_MCE 1085 ---help--- 1086 Include support for machine check handling on old Pentium 5 or WinChip 1087 systems. These typically need to be enabled explicitly on the command 1088 line. 1089 1090config X86_MCE_THRESHOLD 1091 depends on X86_MCE_AMD || X86_MCE_INTEL 1092 def_bool y 1093 1094config X86_MCE_INJECT 1095 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1096 tristate "Machine check injector support" 1097 ---help--- 1098 Provide support for injecting machine checks for testing purposes. 1099 If you don't know what a machine check is and you don't do kernel 1100 QA it is safe to say n. 1101 1102config X86_THERMAL_VECTOR 1103 def_bool y 1104 depends on X86_MCE_INTEL 1105 1106source "arch/x86/events/Kconfig" 1107 1108config X86_LEGACY_VM86 1109 bool "Legacy VM86 support" 1110 default n 1111 depends on X86_32 1112 ---help--- 1113 This option allows user programs to put the CPU into V8086 1114 mode, which is an 80286-era approximation of 16-bit real mode. 1115 1116 Some very old versions of X and/or vbetool require this option 1117 for user mode setting. Similarly, DOSEMU will use it if 1118 available to accelerate real mode DOS programs. However, any 1119 recent version of DOSEMU, X, or vbetool should be fully 1120 functional even without kernel VM86 support, as they will all 1121 fall back to software emulation. Nevertheless, if you are using 1122 a 16-bit DOS program where 16-bit performance matters, vm86 1123 mode might be faster than emulation and you might want to 1124 enable this option. 1125 1126 Note that any app that works on a 64-bit kernel is unlikely to 1127 need this option, as 64-bit kernels don't, and can't, support 1128 V8086 mode. This option is also unrelated to 16-bit protected 1129 mode and is not needed to run most 16-bit programs under Wine. 1130 1131 Enabling this option increases the complexity of the kernel 1132 and slows down exception handling a tiny bit. 1133 1134 If unsure, say N here. 1135 1136config VM86 1137 bool 1138 default X86_LEGACY_VM86 1139 1140config X86_16BIT 1141 bool "Enable support for 16-bit segments" if EXPERT 1142 default y 1143 depends on MODIFY_LDT_SYSCALL 1144 ---help--- 1145 This option is required by programs like Wine to run 16-bit 1146 protected mode legacy code on x86 processors. Disabling 1147 this option saves about 300 bytes on i386, or around 6K text 1148 plus 16K runtime memory on x86-64, 1149 1150config X86_ESPFIX32 1151 def_bool y 1152 depends on X86_16BIT && X86_32 1153 1154config X86_ESPFIX64 1155 def_bool y 1156 depends on X86_16BIT && X86_64 1157 1158config X86_VSYSCALL_EMULATION 1159 bool "Enable vsyscall emulation" if EXPERT 1160 default y 1161 depends on X86_64 1162 ---help--- 1163 This enables emulation of the legacy vsyscall page. Disabling 1164 it is roughly equivalent to booting with vsyscall=none, except 1165 that it will also disable the helpful warning if a program 1166 tries to use a vsyscall. With this option set to N, offending 1167 programs will just segfault, citing addresses of the form 1168 0xffffffffff600?00. 1169 1170 This option is required by many programs built before 2013, and 1171 care should be used even with newer programs if set to N. 1172 1173 Disabling this option saves about 7K of kernel size and 1174 possibly 4K of additional runtime pagetable memory. 1175 1176config TOSHIBA 1177 tristate "Toshiba Laptop support" 1178 depends on X86_32 1179 ---help--- 1180 This adds a driver to safely access the System Management Mode of 1181 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1182 not work on models with a Phoenix BIOS. The System Management Mode 1183 is used to set the BIOS and power saving options on Toshiba portables. 1184 1185 For information on utilities to make use of this driver see the 1186 Toshiba Linux utilities web site at: 1187 <http://www.buzzard.org.uk/toshiba/>. 1188 1189 Say Y if you intend to run this kernel on a Toshiba portable. 1190 Say N otherwise. 1191 1192config I8K 1193 tristate "Dell i8k legacy laptop support" 1194 select HWMON 1195 select SENSORS_DELL_SMM 1196 ---help--- 1197 This option enables legacy /proc/i8k userspace interface in hwmon 1198 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1199 temperature and allows controlling fan speeds of Dell laptops via 1200 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1201 it reports also power and hotkey status. For fan speed control is 1202 needed userspace package i8kutils. 1203 1204 Say Y if you intend to run this kernel on old Dell laptops or want to 1205 use userspace package i8kutils. 1206 Say N otherwise. 1207 1208config X86_REBOOTFIXUPS 1209 bool "Enable X86 board specific fixups for reboot" 1210 depends on X86_32 1211 ---help--- 1212 This enables chipset and/or board specific fixups to be done 1213 in order to get reboot to work correctly. This is only needed on 1214 some combinations of hardware and BIOS. The symptom, for which 1215 this config is intended, is when reboot ends with a stalled/hung 1216 system. 1217 1218 Currently, the only fixup is for the Geode machines using 1219 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1220 1221 Say Y if you want to enable the fixup. Currently, it's safe to 1222 enable this option even if you don't need it. 1223 Say N otherwise. 1224 1225config MICROCODE 1226 bool "CPU microcode loading support" 1227 default y 1228 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1229 select FW_LOADER 1230 ---help--- 1231 If you say Y here, you will be able to update the microcode on 1232 Intel and AMD processors. The Intel support is for the IA32 family, 1233 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1234 AMD support is for families 0x10 and later. You will obviously need 1235 the actual microcode binary data itself which is not shipped with 1236 the Linux kernel. 1237 1238 The preferred method to load microcode from a detached initrd is described 1239 in Documentation/x86/early-microcode.txt. For that you need to enable 1240 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1241 initrd for microcode blobs. 1242 1243 In addition, you can build-in the microcode into the kernel. For that you 1244 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1245 to the CONFIG_EXTRA_FIRMWARE config option. 1246 1247config MICROCODE_INTEL 1248 bool "Intel microcode loading support" 1249 depends on MICROCODE 1250 default MICROCODE 1251 select FW_LOADER 1252 ---help--- 1253 This options enables microcode patch loading support for Intel 1254 processors. 1255 1256 For the current Intel microcode data package go to 1257 <https://downloadcenter.intel.com> and search for 1258 'Linux Processor Microcode Data File'. 1259 1260config MICROCODE_AMD 1261 bool "AMD microcode loading support" 1262 depends on MICROCODE 1263 select FW_LOADER 1264 ---help--- 1265 If you select this option, microcode patch loading support for AMD 1266 processors will be enabled. 1267 1268config MICROCODE_OLD_INTERFACE 1269 def_bool y 1270 depends on MICROCODE 1271 1272config X86_MSR 1273 tristate "/dev/cpu/*/msr - Model-specific register support" 1274 ---help--- 1275 This device gives privileged processes access to the x86 1276 Model-Specific Registers (MSRs). It is a character device with 1277 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1278 MSR accesses are directed to a specific CPU on multi-processor 1279 systems. 1280 1281config X86_CPUID 1282 tristate "/dev/cpu/*/cpuid - CPU information support" 1283 ---help--- 1284 This device gives processes access to the x86 CPUID instruction to 1285 be executed on a specific processor. It is a character device 1286 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1287 /dev/cpu/31/cpuid. 1288 1289choice 1290 prompt "High Memory Support" 1291 default HIGHMEM4G 1292 depends on X86_32 1293 1294config NOHIGHMEM 1295 bool "off" 1296 ---help--- 1297 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1298 However, the address space of 32-bit x86 processors is only 4 1299 Gigabytes large. That means that, if you have a large amount of 1300 physical memory, not all of it can be "permanently mapped" by the 1301 kernel. The physical memory that's not permanently mapped is called 1302 "high memory". 1303 1304 If you are compiling a kernel which will never run on a machine with 1305 more than 1 Gigabyte total physical RAM, answer "off" here (default 1306 choice and suitable for most users). This will result in a "3GB/1GB" 1307 split: 3GB are mapped so that each process sees a 3GB virtual memory 1308 space and the remaining part of the 4GB virtual memory space is used 1309 by the kernel to permanently map as much physical memory as 1310 possible. 1311 1312 If the machine has between 1 and 4 Gigabytes physical RAM, then 1313 answer "4GB" here. 1314 1315 If more than 4 Gigabytes is used then answer "64GB" here. This 1316 selection turns Intel PAE (Physical Address Extension) mode on. 1317 PAE implements 3-level paging on IA32 processors. PAE is fully 1318 supported by Linux, PAE mode is implemented on all recent Intel 1319 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1320 then the kernel will not boot on CPUs that don't support PAE! 1321 1322 The actual amount of total physical memory will either be 1323 auto detected or can be forced by using a kernel command line option 1324 such as "mem=256M". (Try "man bootparam" or see the documentation of 1325 your boot loader (lilo or loadlin) about how to pass options to the 1326 kernel at boot time.) 1327 1328 If unsure, say "off". 1329 1330config HIGHMEM4G 1331 bool "4GB" 1332 ---help--- 1333 Select this if you have a 32-bit processor and between 1 and 4 1334 gigabytes of physical RAM. 1335 1336config HIGHMEM64G 1337 bool "64GB" 1338 depends on !M486 1339 select X86_PAE 1340 ---help--- 1341 Select this if you have a 32-bit processor and more than 4 1342 gigabytes of physical RAM. 1343 1344endchoice 1345 1346choice 1347 prompt "Memory split" if EXPERT 1348 default VMSPLIT_3G 1349 depends on X86_32 1350 ---help--- 1351 Select the desired split between kernel and user memory. 1352 1353 If the address range available to the kernel is less than the 1354 physical memory installed, the remaining memory will be available 1355 as "high memory". Accessing high memory is a little more costly 1356 than low memory, as it needs to be mapped into the kernel first. 1357 Note that increasing the kernel address space limits the range 1358 available to user programs, making the address space there 1359 tighter. Selecting anything other than the default 3G/1G split 1360 will also likely make your kernel incompatible with binary-only 1361 kernel modules. 1362 1363 If you are not absolutely sure what you are doing, leave this 1364 option alone! 1365 1366 config VMSPLIT_3G 1367 bool "3G/1G user/kernel split" 1368 config VMSPLIT_3G_OPT 1369 depends on !X86_PAE 1370 bool "3G/1G user/kernel split (for full 1G low memory)" 1371 config VMSPLIT_2G 1372 bool "2G/2G user/kernel split" 1373 config VMSPLIT_2G_OPT 1374 depends on !X86_PAE 1375 bool "2G/2G user/kernel split (for full 2G low memory)" 1376 config VMSPLIT_1G 1377 bool "1G/3G user/kernel split" 1378endchoice 1379 1380config PAGE_OFFSET 1381 hex 1382 default 0xB0000000 if VMSPLIT_3G_OPT 1383 default 0x80000000 if VMSPLIT_2G 1384 default 0x78000000 if VMSPLIT_2G_OPT 1385 default 0x40000000 if VMSPLIT_1G 1386 default 0xC0000000 1387 depends on X86_32 1388 1389config HIGHMEM 1390 def_bool y 1391 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1392 1393config X86_PAE 1394 bool "PAE (Physical Address Extension) Support" 1395 depends on X86_32 && !HIGHMEM4G 1396 select SWIOTLB 1397 ---help--- 1398 PAE is required for NX support, and furthermore enables 1399 larger swapspace support for non-overcommit purposes. It 1400 has the cost of more pagetable lookup overhead, and also 1401 consumes more pagetable space per process. 1402 1403config X86_5LEVEL 1404 bool "Enable 5-level page tables support" 1405 depends on X86_64 1406 ---help--- 1407 5-level paging enables access to larger address space: 1408 upto 128 PiB of virtual address space and 4 PiB of 1409 physical address space. 1410 1411 It will be supported by future Intel CPUs. 1412 1413 Note: a kernel with this option enabled can only be booted 1414 on machines that support the feature. 1415 1416 See Documentation/x86/x86_64/5level-paging.txt for more 1417 information. 1418 1419 Say N if unsure. 1420 1421config ARCH_PHYS_ADDR_T_64BIT 1422 def_bool y 1423 depends on X86_64 || X86_PAE 1424 1425config ARCH_DMA_ADDR_T_64BIT 1426 def_bool y 1427 depends on X86_64 || HIGHMEM64G 1428 1429config X86_DIRECT_GBPAGES 1430 def_bool y 1431 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 1432 ---help--- 1433 Certain kernel features effectively disable kernel 1434 linear 1 GB mappings (even if the CPU otherwise 1435 supports them), so don't confuse the user by printing 1436 that we have them enabled. 1437 1438config ARCH_HAS_MEM_ENCRYPT 1439 def_bool y 1440 1441config AMD_MEM_ENCRYPT 1442 bool "AMD Secure Memory Encryption (SME) support" 1443 depends on X86_64 && CPU_SUP_AMD 1444 ---help--- 1445 Say yes to enable support for the encryption of system memory. 1446 This requires an AMD processor that supports Secure Memory 1447 Encryption (SME). 1448 1449config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1450 bool "Activate AMD Secure Memory Encryption (SME) by default" 1451 default y 1452 depends on AMD_MEM_ENCRYPT 1453 ---help--- 1454 Say yes to have system memory encrypted by default if running on 1455 an AMD processor that supports Secure Memory Encryption (SME). 1456 1457 If set to Y, then the encryption of system memory can be 1458 deactivated with the mem_encrypt=off command line option. 1459 1460 If set to N, then the encryption of system memory can be 1461 activated with the mem_encrypt=on command line option. 1462 1463config ARCH_USE_MEMREMAP_PROT 1464 def_bool y 1465 depends on AMD_MEM_ENCRYPT 1466 1467# Common NUMA Features 1468config NUMA 1469 bool "Numa Memory Allocation and Scheduler Support" 1470 depends on SMP 1471 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1472 default y if X86_BIGSMP 1473 ---help--- 1474 Enable NUMA (Non Uniform Memory Access) support. 1475 1476 The kernel will try to allocate memory used by a CPU on the 1477 local memory controller of the CPU and add some more 1478 NUMA awareness to the kernel. 1479 1480 For 64-bit this is recommended if the system is Intel Core i7 1481 (or later), AMD Opteron, or EM64T NUMA. 1482 1483 For 32-bit this is only needed if you boot a 32-bit 1484 kernel on a 64-bit NUMA platform. 1485 1486 Otherwise, you should say N. 1487 1488config AMD_NUMA 1489 def_bool y 1490 prompt "Old style AMD Opteron NUMA detection" 1491 depends on X86_64 && NUMA && PCI 1492 ---help--- 1493 Enable AMD NUMA node topology detection. You should say Y here if 1494 you have a multi processor AMD system. This uses an old method to 1495 read the NUMA configuration directly from the builtin Northbridge 1496 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1497 which also takes priority if both are compiled in. 1498 1499config X86_64_ACPI_NUMA 1500 def_bool y 1501 prompt "ACPI NUMA detection" 1502 depends on X86_64 && NUMA && ACPI && PCI 1503 select ACPI_NUMA 1504 ---help--- 1505 Enable ACPI SRAT based node topology detection. 1506 1507# Some NUMA nodes have memory ranges that span 1508# other nodes. Even though a pfn is valid and 1509# between a node's start and end pfns, it may not 1510# reside on that node. See memmap_init_zone() 1511# for details. 1512config NODES_SPAN_OTHER_NODES 1513 def_bool y 1514 depends on X86_64_ACPI_NUMA 1515 1516config NUMA_EMU 1517 bool "NUMA emulation" 1518 depends on NUMA 1519 ---help--- 1520 Enable NUMA emulation. A flat machine will be split 1521 into virtual nodes when booted with "numa=fake=N", where N is the 1522 number of nodes. This is only useful for debugging. 1523 1524config NODES_SHIFT 1525 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1526 range 1 10 1527 default "10" if MAXSMP 1528 default "6" if X86_64 1529 default "3" 1530 depends on NEED_MULTIPLE_NODES 1531 ---help--- 1532 Specify the maximum number of NUMA Nodes available on the target 1533 system. Increases memory reserved to accommodate various tables. 1534 1535config ARCH_HAVE_MEMORY_PRESENT 1536 def_bool y 1537 depends on X86_32 && DISCONTIGMEM 1538 1539config NEED_NODE_MEMMAP_SIZE 1540 def_bool y 1541 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1542 1543config ARCH_FLATMEM_ENABLE 1544 def_bool y 1545 depends on X86_32 && !NUMA 1546 1547config ARCH_DISCONTIGMEM_ENABLE 1548 def_bool y 1549 depends on NUMA && X86_32 1550 1551config ARCH_DISCONTIGMEM_DEFAULT 1552 def_bool y 1553 depends on NUMA && X86_32 1554 1555config ARCH_SPARSEMEM_ENABLE 1556 def_bool y 1557 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1558 select SPARSEMEM_STATIC if X86_32 1559 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1560 1561config ARCH_SPARSEMEM_DEFAULT 1562 def_bool y 1563 depends on X86_64 1564 1565config ARCH_SELECT_MEMORY_MODEL 1566 def_bool y 1567 depends on ARCH_SPARSEMEM_ENABLE 1568 1569config ARCH_MEMORY_PROBE 1570 bool "Enable sysfs memory/probe interface" 1571 depends on X86_64 && MEMORY_HOTPLUG 1572 help 1573 This option enables a sysfs memory/probe interface for testing. 1574 See Documentation/memory-hotplug.txt for more information. 1575 If you are unsure how to answer this question, answer N. 1576 1577config ARCH_PROC_KCORE_TEXT 1578 def_bool y 1579 depends on X86_64 && PROC_KCORE 1580 1581config ILLEGAL_POINTER_VALUE 1582 hex 1583 default 0 if X86_32 1584 default 0xdead000000000000 if X86_64 1585 1586source "mm/Kconfig" 1587 1588config X86_PMEM_LEGACY_DEVICE 1589 bool 1590 1591config X86_PMEM_LEGACY 1592 tristate "Support non-standard NVDIMMs and ADR protected memory" 1593 depends on PHYS_ADDR_T_64BIT 1594 depends on BLK_DEV 1595 select X86_PMEM_LEGACY_DEVICE 1596 select LIBNVDIMM 1597 help 1598 Treat memory marked using the non-standard e820 type of 12 as used 1599 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1600 The kernel will offer these regions to the 'pmem' driver so 1601 they can be used for persistent storage. 1602 1603 Say Y if unsure. 1604 1605config HIGHPTE 1606 bool "Allocate 3rd-level pagetables from highmem" 1607 depends on HIGHMEM 1608 ---help--- 1609 The VM uses one page table entry for each page of physical memory. 1610 For systems with a lot of RAM, this can be wasteful of precious 1611 low memory. Setting this option will put user-space page table 1612 entries in high memory. 1613 1614config X86_CHECK_BIOS_CORRUPTION 1615 bool "Check for low memory corruption" 1616 ---help--- 1617 Periodically check for memory corruption in low memory, which 1618 is suspected to be caused by BIOS. Even when enabled in the 1619 configuration, it is disabled at runtime. Enable it by 1620 setting "memory_corruption_check=1" on the kernel command 1621 line. By default it scans the low 64k of memory every 60 1622 seconds; see the memory_corruption_check_size and 1623 memory_corruption_check_period parameters in 1624 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1625 1626 When enabled with the default parameters, this option has 1627 almost no overhead, as it reserves a relatively small amount 1628 of memory and scans it infrequently. It both detects corruption 1629 and prevents it from affecting the running system. 1630 1631 It is, however, intended as a diagnostic tool; if repeatable 1632 BIOS-originated corruption always affects the same memory, 1633 you can use memmap= to prevent the kernel from using that 1634 memory. 1635 1636config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1637 bool "Set the default setting of memory_corruption_check" 1638 depends on X86_CHECK_BIOS_CORRUPTION 1639 default y 1640 ---help--- 1641 Set whether the default state of memory_corruption_check is 1642 on or off. 1643 1644config X86_RESERVE_LOW 1645 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1646 default 64 1647 range 4 640 1648 ---help--- 1649 Specify the amount of low memory to reserve for the BIOS. 1650 1651 The first page contains BIOS data structures that the kernel 1652 must not use, so that page must always be reserved. 1653 1654 By default we reserve the first 64K of physical RAM, as a 1655 number of BIOSes are known to corrupt that memory range 1656 during events such as suspend/resume or monitor cable 1657 insertion, so it must not be used by the kernel. 1658 1659 You can set this to 4 if you are absolutely sure that you 1660 trust the BIOS to get all its memory reservations and usages 1661 right. If you know your BIOS have problems beyond the 1662 default 64K area, you can set this to 640 to avoid using the 1663 entire low memory range. 1664 1665 If you have doubts about the BIOS (e.g. suspend/resume does 1666 not work or there's kernel crashes after certain hardware 1667 hotplug events) then you might want to enable 1668 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1669 typical corruption patterns. 1670 1671 Leave this to the default value of 64 if you are unsure. 1672 1673config MATH_EMULATION 1674 bool 1675 depends on MODIFY_LDT_SYSCALL 1676 prompt "Math emulation" if X86_32 1677 ---help--- 1678 Linux can emulate a math coprocessor (used for floating point 1679 operations) if you don't have one. 486DX and Pentium processors have 1680 a math coprocessor built in, 486SX and 386 do not, unless you added 1681 a 487DX or 387, respectively. (The messages during boot time can 1682 give you some hints here ["man dmesg"].) Everyone needs either a 1683 coprocessor or this emulation. 1684 1685 If you don't have a math coprocessor, you need to say Y here; if you 1686 say Y here even though you have a coprocessor, the coprocessor will 1687 be used nevertheless. (This behavior can be changed with the kernel 1688 command line option "no387", which comes handy if your coprocessor 1689 is broken. Try "man bootparam" or see the documentation of your boot 1690 loader (lilo or loadlin) about how to pass options to the kernel at 1691 boot time.) This means that it is a good idea to say Y here if you 1692 intend to use this kernel on different machines. 1693 1694 More information about the internals of the Linux math coprocessor 1695 emulation can be found in <file:arch/x86/math-emu/README>. 1696 1697 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1698 kernel, it won't hurt. 1699 1700config MTRR 1701 def_bool y 1702 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1703 ---help--- 1704 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1705 the Memory Type Range Registers (MTRRs) may be used to control 1706 processor access to memory ranges. This is most useful if you have 1707 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1708 allows bus write transfers to be combined into a larger transfer 1709 before bursting over the PCI/AGP bus. This can increase performance 1710 of image write operations 2.5 times or more. Saying Y here creates a 1711 /proc/mtrr file which may be used to manipulate your processor's 1712 MTRRs. Typically the X server should use this. 1713 1714 This code has a reasonably generic interface so that similar 1715 control registers on other processors can be easily supported 1716 as well: 1717 1718 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1719 Registers (ARRs) which provide a similar functionality to MTRRs. For 1720 these, the ARRs are used to emulate the MTRRs. 1721 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1722 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1723 write-combining. All of these processors are supported by this code 1724 and it makes sense to say Y here if you have one of them. 1725 1726 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1727 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1728 can lead to all sorts of problems, so it's good to say Y here. 1729 1730 You can safely say Y even if your machine doesn't have MTRRs, you'll 1731 just add about 9 KB to your kernel. 1732 1733 See <file:Documentation/x86/mtrr.txt> for more information. 1734 1735config MTRR_SANITIZER 1736 def_bool y 1737 prompt "MTRR cleanup support" 1738 depends on MTRR 1739 ---help--- 1740 Convert MTRR layout from continuous to discrete, so X drivers can 1741 add writeback entries. 1742 1743 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1744 The largest mtrr entry size for a continuous block can be set with 1745 mtrr_chunk_size. 1746 1747 If unsure, say Y. 1748 1749config MTRR_SANITIZER_ENABLE_DEFAULT 1750 int "MTRR cleanup enable value (0-1)" 1751 range 0 1 1752 default "0" 1753 depends on MTRR_SANITIZER 1754 ---help--- 1755 Enable mtrr cleanup default value 1756 1757config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1758 int "MTRR cleanup spare reg num (0-7)" 1759 range 0 7 1760 default "1" 1761 depends on MTRR_SANITIZER 1762 ---help--- 1763 mtrr cleanup spare entries default, it can be changed via 1764 mtrr_spare_reg_nr=N on the kernel command line. 1765 1766config X86_PAT 1767 def_bool y 1768 prompt "x86 PAT support" if EXPERT 1769 depends on MTRR 1770 ---help--- 1771 Use PAT attributes to setup page level cache control. 1772 1773 PATs are the modern equivalents of MTRRs and are much more 1774 flexible than MTRRs. 1775 1776 Say N here if you see bootup problems (boot crash, boot hang, 1777 spontaneous reboots) or a non-working video driver. 1778 1779 If unsure, say Y. 1780 1781config ARCH_USES_PG_UNCACHED 1782 def_bool y 1783 depends on X86_PAT 1784 1785config ARCH_RANDOM 1786 def_bool y 1787 prompt "x86 architectural random number generator" if EXPERT 1788 ---help--- 1789 Enable the x86 architectural RDRAND instruction 1790 (Intel Bull Mountain technology) to generate random numbers. 1791 If supported, this is a high bandwidth, cryptographically 1792 secure hardware random number generator. 1793 1794config X86_SMAP 1795 def_bool y 1796 prompt "Supervisor Mode Access Prevention" if EXPERT 1797 ---help--- 1798 Supervisor Mode Access Prevention (SMAP) is a security 1799 feature in newer Intel processors. There is a small 1800 performance cost if this enabled and turned on; there is 1801 also a small increase in the kernel size if this is enabled. 1802 1803 If unsure, say Y. 1804 1805config X86_INTEL_MPX 1806 prompt "Intel MPX (Memory Protection Extensions)" 1807 def_bool n 1808 # Note: only available in 64-bit mode due to VMA flags shortage 1809 depends on CPU_SUP_INTEL && X86_64 1810 select ARCH_USES_HIGH_VMA_FLAGS 1811 ---help--- 1812 MPX provides hardware features that can be used in 1813 conjunction with compiler-instrumented code to check 1814 memory references. It is designed to detect buffer 1815 overflow or underflow bugs. 1816 1817 This option enables running applications which are 1818 instrumented or otherwise use MPX. It does not use MPX 1819 itself inside the kernel or to protect the kernel 1820 against bad memory references. 1821 1822 Enabling this option will make the kernel larger: 1823 ~8k of kernel text and 36 bytes of data on a 64-bit 1824 defconfig. It adds a long to the 'mm_struct' which 1825 will increase the kernel memory overhead of each 1826 process and adds some branches to paths used during 1827 exec() and munmap(). 1828 1829 For details, see Documentation/x86/intel_mpx.txt 1830 1831 If unsure, say N. 1832 1833config X86_INTEL_MEMORY_PROTECTION_KEYS 1834 prompt "Intel Memory Protection Keys" 1835 def_bool y 1836 # Note: only available in 64-bit mode 1837 depends on CPU_SUP_INTEL && X86_64 1838 select ARCH_USES_HIGH_VMA_FLAGS 1839 select ARCH_HAS_PKEYS 1840 ---help--- 1841 Memory Protection Keys provides a mechanism for enforcing 1842 page-based protections, but without requiring modification of the 1843 page tables when an application changes protection domains. 1844 1845 For details, see Documentation/x86/protection-keys.txt 1846 1847 If unsure, say y. 1848 1849config EFI 1850 bool "EFI runtime service support" 1851 depends on ACPI 1852 select UCS2_STRING 1853 select EFI_RUNTIME_WRAPPERS 1854 ---help--- 1855 This enables the kernel to use EFI runtime services that are 1856 available (such as the EFI variable services). 1857 1858 This option is only useful on systems that have EFI firmware. 1859 In addition, you should use the latest ELILO loader available 1860 at <http://elilo.sourceforge.net> in order to take advantage 1861 of EFI runtime services. However, even with this option, the 1862 resultant kernel should continue to boot on existing non-EFI 1863 platforms. 1864 1865config EFI_STUB 1866 bool "EFI stub support" 1867 depends on EFI && !X86_USE_3DNOW 1868 select RELOCATABLE 1869 ---help--- 1870 This kernel feature allows a bzImage to be loaded directly 1871 by EFI firmware without the use of a bootloader. 1872 1873 See Documentation/efi-stub.txt for more information. 1874 1875config EFI_MIXED 1876 bool "EFI mixed-mode support" 1877 depends on EFI_STUB && X86_64 1878 ---help--- 1879 Enabling this feature allows a 64-bit kernel to be booted 1880 on a 32-bit firmware, provided that your CPU supports 64-bit 1881 mode. 1882 1883 Note that it is not possible to boot a mixed-mode enabled 1884 kernel via the EFI boot stub - a bootloader that supports 1885 the EFI handover protocol must be used. 1886 1887 If unsure, say N. 1888 1889config SECCOMP 1890 def_bool y 1891 prompt "Enable seccomp to safely compute untrusted bytecode" 1892 ---help--- 1893 This kernel feature is useful for number crunching applications 1894 that may need to compute untrusted bytecode during their 1895 execution. By using pipes or other transports made available to 1896 the process as file descriptors supporting the read/write 1897 syscalls, it's possible to isolate those applications in 1898 their own address space using seccomp. Once seccomp is 1899 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1900 and the task is only allowed to execute a few safe syscalls 1901 defined by each seccomp mode. 1902 1903 If unsure, say Y. Only embedded should say N here. 1904 1905source kernel/Kconfig.hz 1906 1907config KEXEC 1908 bool "kexec system call" 1909 select KEXEC_CORE 1910 ---help--- 1911 kexec is a system call that implements the ability to shutdown your 1912 current kernel, and to start another kernel. It is like a reboot 1913 but it is independent of the system firmware. And like a reboot 1914 you can start any kernel with it, not just Linux. 1915 1916 The name comes from the similarity to the exec system call. 1917 1918 It is an ongoing process to be certain the hardware in a machine 1919 is properly shutdown, so do not be surprised if this code does not 1920 initially work for you. As of this writing the exact hardware 1921 interface is strongly in flux, so no good recommendation can be 1922 made. 1923 1924config KEXEC_FILE 1925 bool "kexec file based system call" 1926 select KEXEC_CORE 1927 select BUILD_BIN2C 1928 depends on X86_64 1929 depends on CRYPTO=y 1930 depends on CRYPTO_SHA256=y 1931 ---help--- 1932 This is new version of kexec system call. This system call is 1933 file based and takes file descriptors as system call argument 1934 for kernel and initramfs as opposed to list of segments as 1935 accepted by previous system call. 1936 1937config KEXEC_VERIFY_SIG 1938 bool "Verify kernel signature during kexec_file_load() syscall" 1939 depends on KEXEC_FILE 1940 ---help--- 1941 This option makes kernel signature verification mandatory for 1942 the kexec_file_load() syscall. 1943 1944 In addition to that option, you need to enable signature 1945 verification for the corresponding kernel image type being 1946 loaded in order for this to work. 1947 1948config KEXEC_BZIMAGE_VERIFY_SIG 1949 bool "Enable bzImage signature verification support" 1950 depends on KEXEC_VERIFY_SIG 1951 depends on SIGNED_PE_FILE_VERIFICATION 1952 select SYSTEM_TRUSTED_KEYRING 1953 ---help--- 1954 Enable bzImage signature verification support. 1955 1956config CRASH_DUMP 1957 bool "kernel crash dumps" 1958 depends on X86_64 || (X86_32 && HIGHMEM) 1959 ---help--- 1960 Generate crash dump after being started by kexec. 1961 This should be normally only set in special crash dump kernels 1962 which are loaded in the main kernel with kexec-tools into 1963 a specially reserved region and then later executed after 1964 a crash by kdump/kexec. The crash dump kernel must be compiled 1965 to a memory address not used by the main kernel or BIOS using 1966 PHYSICAL_START, or it must be built as a relocatable image 1967 (CONFIG_RELOCATABLE=y). 1968 For more details see Documentation/kdump/kdump.txt 1969 1970config KEXEC_JUMP 1971 bool "kexec jump" 1972 depends on KEXEC && HIBERNATION 1973 ---help--- 1974 Jump between original kernel and kexeced kernel and invoke 1975 code in physical address mode via KEXEC 1976 1977config PHYSICAL_START 1978 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1979 default "0x1000000" 1980 ---help--- 1981 This gives the physical address where the kernel is loaded. 1982 1983 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1984 bzImage will decompress itself to above physical address and 1985 run from there. Otherwise, bzImage will run from the address where 1986 it has been loaded by the boot loader and will ignore above physical 1987 address. 1988 1989 In normal kdump cases one does not have to set/change this option 1990 as now bzImage can be compiled as a completely relocatable image 1991 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1992 address. This option is mainly useful for the folks who don't want 1993 to use a bzImage for capturing the crash dump and want to use a 1994 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1995 to be specifically compiled to run from a specific memory area 1996 (normally a reserved region) and this option comes handy. 1997 1998 So if you are using bzImage for capturing the crash dump, 1999 leave the value here unchanged to 0x1000000 and set 2000 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2001 for capturing the crash dump change this value to start of 2002 the reserved region. In other words, it can be set based on 2003 the "X" value as specified in the "crashkernel=YM@XM" 2004 command line boot parameter passed to the panic-ed 2005 kernel. Please take a look at Documentation/kdump/kdump.txt 2006 for more details about crash dumps. 2007 2008 Usage of bzImage for capturing the crash dump is recommended as 2009 one does not have to build two kernels. Same kernel can be used 2010 as production kernel and capture kernel. Above option should have 2011 gone away after relocatable bzImage support is introduced. But it 2012 is present because there are users out there who continue to use 2013 vmlinux for dump capture. This option should go away down the 2014 line. 2015 2016 Don't change this unless you know what you are doing. 2017 2018config RELOCATABLE 2019 bool "Build a relocatable kernel" 2020 default y 2021 ---help--- 2022 This builds a kernel image that retains relocation information 2023 so it can be loaded someplace besides the default 1MB. 2024 The relocations tend to make the kernel binary about 10% larger, 2025 but are discarded at runtime. 2026 2027 One use is for the kexec on panic case where the recovery kernel 2028 must live at a different physical address than the primary 2029 kernel. 2030 2031 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2032 it has been loaded at and the compile time physical address 2033 (CONFIG_PHYSICAL_START) is used as the minimum location. 2034 2035config RANDOMIZE_BASE 2036 bool "Randomize the address of the kernel image (KASLR)" 2037 depends on RELOCATABLE 2038 default y 2039 ---help--- 2040 In support of Kernel Address Space Layout Randomization (KASLR), 2041 this randomizes the physical address at which the kernel image 2042 is decompressed and the virtual address where the kernel 2043 image is mapped, as a security feature that deters exploit 2044 attempts relying on knowledge of the location of kernel 2045 code internals. 2046 2047 On 64-bit, the kernel physical and virtual addresses are 2048 randomized separately. The physical address will be anywhere 2049 between 16MB and the top of physical memory (up to 64TB). The 2050 virtual address will be randomized from 16MB up to 1GB (9 bits 2051 of entropy). Note that this also reduces the memory space 2052 available to kernel modules from 1.5GB to 1GB. 2053 2054 On 32-bit, the kernel physical and virtual addresses are 2055 randomized together. They will be randomized from 16MB up to 2056 512MB (8 bits of entropy). 2057 2058 Entropy is generated using the RDRAND instruction if it is 2059 supported. If RDTSC is supported, its value is mixed into 2060 the entropy pool as well. If neither RDRAND nor RDTSC are 2061 supported, then entropy is read from the i8254 timer. The 2062 usable entropy is limited by the kernel being built using 2063 2GB addressing, and that PHYSICAL_ALIGN must be at a 2064 minimum of 2MB. As a result, only 10 bits of entropy are 2065 theoretically possible, but the implementations are further 2066 limited due to memory layouts. 2067 2068 If unsure, say Y. 2069 2070# Relocation on x86 needs some additional build support 2071config X86_NEED_RELOCS 2072 def_bool y 2073 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2074 2075config PHYSICAL_ALIGN 2076 hex "Alignment value to which kernel should be aligned" 2077 default "0x200000" 2078 range 0x2000 0x1000000 if X86_32 2079 range 0x200000 0x1000000 if X86_64 2080 ---help--- 2081 This value puts the alignment restrictions on physical address 2082 where kernel is loaded and run from. Kernel is compiled for an 2083 address which meets above alignment restriction. 2084 2085 If bootloader loads the kernel at a non-aligned address and 2086 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2087 address aligned to above value and run from there. 2088 2089 If bootloader loads the kernel at a non-aligned address and 2090 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2091 load address and decompress itself to the address it has been 2092 compiled for and run from there. The address for which kernel is 2093 compiled already meets above alignment restrictions. Hence the 2094 end result is that kernel runs from a physical address meeting 2095 above alignment restrictions. 2096 2097 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2098 this value must be a multiple of 0x200000. 2099 2100 Don't change this unless you know what you are doing. 2101 2102config RANDOMIZE_MEMORY 2103 bool "Randomize the kernel memory sections" 2104 depends on X86_64 2105 depends on RANDOMIZE_BASE 2106 default RANDOMIZE_BASE 2107 ---help--- 2108 Randomizes the base virtual address of kernel memory sections 2109 (physical memory mapping, vmalloc & vmemmap). This security feature 2110 makes exploits relying on predictable memory locations less reliable. 2111 2112 The order of allocations remains unchanged. Entropy is generated in 2113 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2114 configuration have in average 30,000 different possible virtual 2115 addresses for each memory section. 2116 2117 If unsure, say Y. 2118 2119config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2120 hex "Physical memory mapping padding" if EXPERT 2121 depends on RANDOMIZE_MEMORY 2122 default "0xa" if MEMORY_HOTPLUG 2123 default "0x0" 2124 range 0x1 0x40 if MEMORY_HOTPLUG 2125 range 0x0 0x40 2126 ---help--- 2127 Define the padding in terabytes added to the existing physical 2128 memory size during kernel memory randomization. It is useful 2129 for memory hotplug support but reduces the entropy available for 2130 address randomization. 2131 2132 If unsure, leave at the default value. 2133 2134config HOTPLUG_CPU 2135 bool "Support for hot-pluggable CPUs" 2136 depends on SMP 2137 ---help--- 2138 Say Y here to allow turning CPUs off and on. CPUs can be 2139 controlled through /sys/devices/system/cpu. 2140 ( Note: power management support will enable this option 2141 automatically on SMP systems. ) 2142 Say N if you want to disable CPU hotplug. 2143 2144config BOOTPARAM_HOTPLUG_CPU0 2145 bool "Set default setting of cpu0_hotpluggable" 2146 default n 2147 depends on HOTPLUG_CPU 2148 ---help--- 2149 Set whether default state of cpu0_hotpluggable is on or off. 2150 2151 Say Y here to enable CPU0 hotplug by default. If this switch 2152 is turned on, there is no need to give cpu0_hotplug kernel 2153 parameter and the CPU0 hotplug feature is enabled by default. 2154 2155 Please note: there are two known CPU0 dependencies if you want 2156 to enable the CPU0 hotplug feature either by this switch or by 2157 cpu0_hotplug kernel parameter. 2158 2159 First, resume from hibernate or suspend always starts from CPU0. 2160 So hibernate and suspend are prevented if CPU0 is offline. 2161 2162 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2163 offline if any interrupt can not migrate out of CPU0. There may 2164 be other CPU0 dependencies. 2165 2166 Please make sure the dependencies are under your control before 2167 you enable this feature. 2168 2169 Say N if you don't want to enable CPU0 hotplug feature by default. 2170 You still can enable the CPU0 hotplug feature at boot by kernel 2171 parameter cpu0_hotplug. 2172 2173config DEBUG_HOTPLUG_CPU0 2174 def_bool n 2175 prompt "Debug CPU0 hotplug" 2176 depends on HOTPLUG_CPU 2177 ---help--- 2178 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2179 soon as possible and boots up userspace with CPU0 offlined. User 2180 can online CPU0 back after boot time. 2181 2182 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2183 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2184 compilation or giving cpu0_hotplug kernel parameter at boot. 2185 2186 If unsure, say N. 2187 2188config COMPAT_VDSO 2189 def_bool n 2190 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2191 depends on COMPAT_32 2192 ---help--- 2193 Certain buggy versions of glibc will crash if they are 2194 presented with a 32-bit vDSO that is not mapped at the address 2195 indicated in its segment table. 2196 2197 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2198 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2199 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2200 the only released version with the bug, but OpenSUSE 9 2201 contains a buggy "glibc 2.3.2". 2202 2203 The symptom of the bug is that everything crashes on startup, saying: 2204 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2205 2206 Saying Y here changes the default value of the vdso32 boot 2207 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2208 This works around the glibc bug but hurts performance. 2209 2210 If unsure, say N: if you are compiling your own kernel, you 2211 are unlikely to be using a buggy version of glibc. 2212 2213choice 2214 prompt "vsyscall table for legacy applications" 2215 depends on X86_64 2216 default LEGACY_VSYSCALL_EMULATE 2217 help 2218 Legacy user code that does not know how to find the vDSO expects 2219 to be able to issue three syscalls by calling fixed addresses in 2220 kernel space. Since this location is not randomized with ASLR, 2221 it can be used to assist security vulnerability exploitation. 2222 2223 This setting can be changed at boot time via the kernel command 2224 line parameter vsyscall=[native|emulate|none]. 2225 2226 On a system with recent enough glibc (2.14 or newer) and no 2227 static binaries, you can say None without a performance penalty 2228 to improve security. 2229 2230 If unsure, select "Emulate". 2231 2232 config LEGACY_VSYSCALL_NATIVE 2233 bool "Native" 2234 help 2235 Actual executable code is located in the fixed vsyscall 2236 address mapping, implementing time() efficiently. Since 2237 this makes the mapping executable, it can be used during 2238 security vulnerability exploitation (traditionally as 2239 ROP gadgets). This configuration is not recommended. 2240 2241 config LEGACY_VSYSCALL_EMULATE 2242 bool "Emulate" 2243 help 2244 The kernel traps and emulates calls into the fixed 2245 vsyscall address mapping. This makes the mapping 2246 non-executable, but it still contains known contents, 2247 which could be used in certain rare security vulnerability 2248 exploits. This configuration is recommended when userspace 2249 still uses the vsyscall area. 2250 2251 config LEGACY_VSYSCALL_NONE 2252 bool "None" 2253 help 2254 There will be no vsyscall mapping at all. This will 2255 eliminate any risk of ASLR bypass due to the vsyscall 2256 fixed address mapping. Attempts to use the vsyscalls 2257 will be reported to dmesg, so that either old or 2258 malicious userspace programs can be identified. 2259 2260endchoice 2261 2262config CMDLINE_BOOL 2263 bool "Built-in kernel command line" 2264 ---help--- 2265 Allow for specifying boot arguments to the kernel at 2266 build time. On some systems (e.g. embedded ones), it is 2267 necessary or convenient to provide some or all of the 2268 kernel boot arguments with the kernel itself (that is, 2269 to not rely on the boot loader to provide them.) 2270 2271 To compile command line arguments into the kernel, 2272 set this option to 'Y', then fill in the 2273 boot arguments in CONFIG_CMDLINE. 2274 2275 Systems with fully functional boot loaders (i.e. non-embedded) 2276 should leave this option set to 'N'. 2277 2278config CMDLINE 2279 string "Built-in kernel command string" 2280 depends on CMDLINE_BOOL 2281 default "" 2282 ---help--- 2283 Enter arguments here that should be compiled into the kernel 2284 image and used at boot time. If the boot loader provides a 2285 command line at boot time, it is appended to this string to 2286 form the full kernel command line, when the system boots. 2287 2288 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2289 change this behavior. 2290 2291 In most cases, the command line (whether built-in or provided 2292 by the boot loader) should specify the device for the root 2293 file system. 2294 2295config CMDLINE_OVERRIDE 2296 bool "Built-in command line overrides boot loader arguments" 2297 depends on CMDLINE_BOOL 2298 ---help--- 2299 Set this option to 'Y' to have the kernel ignore the boot loader 2300 command line, and use ONLY the built-in command line. 2301 2302 This is used to work around broken boot loaders. This should 2303 be set to 'N' under normal conditions. 2304 2305config MODIFY_LDT_SYSCALL 2306 bool "Enable the LDT (local descriptor table)" if EXPERT 2307 default y 2308 ---help--- 2309 Linux can allow user programs to install a per-process x86 2310 Local Descriptor Table (LDT) using the modify_ldt(2) system 2311 call. This is required to run 16-bit or segmented code such as 2312 DOSEMU or some Wine programs. It is also used by some very old 2313 threading libraries. 2314 2315 Enabling this feature adds a small amount of overhead to 2316 context switches and increases the low-level kernel attack 2317 surface. Disabling it removes the modify_ldt(2) system call. 2318 2319 Saying 'N' here may make sense for embedded or server kernels. 2320 2321source "kernel/livepatch/Kconfig" 2322 2323endmenu 2324 2325config ARCH_HAS_ADD_PAGES 2326 def_bool y 2327 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2328 2329config ARCH_ENABLE_MEMORY_HOTPLUG 2330 def_bool y 2331 depends on X86_64 || (X86_32 && HIGHMEM) 2332 2333config ARCH_ENABLE_MEMORY_HOTREMOVE 2334 def_bool y 2335 depends on MEMORY_HOTPLUG 2336 2337config USE_PERCPU_NUMA_NODE_ID 2338 def_bool y 2339 depends on NUMA 2340 2341config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2342 def_bool y 2343 depends on X86_64 || X86_PAE 2344 2345config ARCH_ENABLE_HUGEPAGE_MIGRATION 2346 def_bool y 2347 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2348 2349config ARCH_ENABLE_THP_MIGRATION 2350 def_bool y 2351 depends on X86_64 && TRANSPARENT_HUGEPAGE 2352 2353menu "Power management and ACPI options" 2354 2355config ARCH_HIBERNATION_HEADER 2356 def_bool y 2357 depends on X86_64 && HIBERNATION 2358 2359source "kernel/power/Kconfig" 2360 2361source "drivers/acpi/Kconfig" 2362 2363source "drivers/sfi/Kconfig" 2364 2365config X86_APM_BOOT 2366 def_bool y 2367 depends on APM 2368 2369menuconfig APM 2370 tristate "APM (Advanced Power Management) BIOS support" 2371 depends on X86_32 && PM_SLEEP 2372 ---help--- 2373 APM is a BIOS specification for saving power using several different 2374 techniques. This is mostly useful for battery powered laptops with 2375 APM compliant BIOSes. If you say Y here, the system time will be 2376 reset after a RESUME operation, the /proc/apm device will provide 2377 battery status information, and user-space programs will receive 2378 notification of APM "events" (e.g. battery status change). 2379 2380 If you select "Y" here, you can disable actual use of the APM 2381 BIOS by passing the "apm=off" option to the kernel at boot time. 2382 2383 Note that the APM support is almost completely disabled for 2384 machines with more than one CPU. 2385 2386 In order to use APM, you will need supporting software. For location 2387 and more information, read <file:Documentation/power/apm-acpi.txt> 2388 and the Battery Powered Linux mini-HOWTO, available from 2389 <http://www.tldp.org/docs.html#howto>. 2390 2391 This driver does not spin down disk drives (see the hdparm(8) 2392 manpage ("man 8 hdparm") for that), and it doesn't turn off 2393 VESA-compliant "green" monitors. 2394 2395 This driver does not support the TI 4000M TravelMate and the ACER 2396 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2397 desktop machines also don't have compliant BIOSes, and this driver 2398 may cause those machines to panic during the boot phase. 2399 2400 Generally, if you don't have a battery in your machine, there isn't 2401 much point in using this driver and you should say N. If you get 2402 random kernel OOPSes or reboots that don't seem to be related to 2403 anything, try disabling/enabling this option (or disabling/enabling 2404 APM in your BIOS). 2405 2406 Some other things you should try when experiencing seemingly random, 2407 "weird" problems: 2408 2409 1) make sure that you have enough swap space and that it is 2410 enabled. 2411 2) pass the "no-hlt" option to the kernel 2412 3) switch on floating point emulation in the kernel and pass 2413 the "no387" option to the kernel 2414 4) pass the "floppy=nodma" option to the kernel 2415 5) pass the "mem=4M" option to the kernel (thereby disabling 2416 all but the first 4 MB of RAM) 2417 6) make sure that the CPU is not over clocked. 2418 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2419 8) disable the cache from your BIOS settings 2420 9) install a fan for the video card or exchange video RAM 2421 10) install a better fan for the CPU 2422 11) exchange RAM chips 2423 12) exchange the motherboard. 2424 2425 To compile this driver as a module, choose M here: the 2426 module will be called apm. 2427 2428if APM 2429 2430config APM_IGNORE_USER_SUSPEND 2431 bool "Ignore USER SUSPEND" 2432 ---help--- 2433 This option will ignore USER SUSPEND requests. On machines with a 2434 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2435 series notebooks, it is necessary to say Y because of a BIOS bug. 2436 2437config APM_DO_ENABLE 2438 bool "Enable PM at boot time" 2439 ---help--- 2440 Enable APM features at boot time. From page 36 of the APM BIOS 2441 specification: "When disabled, the APM BIOS does not automatically 2442 power manage devices, enter the Standby State, enter the Suspend 2443 State, or take power saving steps in response to CPU Idle calls." 2444 This driver will make CPU Idle calls when Linux is idle (unless this 2445 feature is turned off -- see "Do CPU IDLE calls", below). This 2446 should always save battery power, but more complicated APM features 2447 will be dependent on your BIOS implementation. You may need to turn 2448 this option off if your computer hangs at boot time when using APM 2449 support, or if it beeps continuously instead of suspending. Turn 2450 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2451 T400CDT. This is off by default since most machines do fine without 2452 this feature. 2453 2454config APM_CPU_IDLE 2455 depends on CPU_IDLE 2456 bool "Make CPU Idle calls when idle" 2457 ---help--- 2458 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2459 On some machines, this can activate improved power savings, such as 2460 a slowed CPU clock rate, when the machine is idle. These idle calls 2461 are made after the idle loop has run for some length of time (e.g., 2462 333 mS). On some machines, this will cause a hang at boot time or 2463 whenever the CPU becomes idle. (On machines with more than one CPU, 2464 this option does nothing.) 2465 2466config APM_DISPLAY_BLANK 2467 bool "Enable console blanking using APM" 2468 ---help--- 2469 Enable console blanking using the APM. Some laptops can use this to 2470 turn off the LCD backlight when the screen blanker of the Linux 2471 virtual console blanks the screen. Note that this is only used by 2472 the virtual console screen blanker, and won't turn off the backlight 2473 when using the X Window system. This also doesn't have anything to 2474 do with your VESA-compliant power-saving monitor. Further, this 2475 option doesn't work for all laptops -- it might not turn off your 2476 backlight at all, or it might print a lot of errors to the console, 2477 especially if you are using gpm. 2478 2479config APM_ALLOW_INTS 2480 bool "Allow interrupts during APM BIOS calls" 2481 ---help--- 2482 Normally we disable external interrupts while we are making calls to 2483 the APM BIOS as a measure to lessen the effects of a badly behaving 2484 BIOS implementation. The BIOS should reenable interrupts if it 2485 needs to. Unfortunately, some BIOSes do not -- especially those in 2486 many of the newer IBM Thinkpads. If you experience hangs when you 2487 suspend, try setting this to Y. Otherwise, say N. 2488 2489endif # APM 2490 2491source "drivers/cpufreq/Kconfig" 2492 2493source "drivers/cpuidle/Kconfig" 2494 2495source "drivers/idle/Kconfig" 2496 2497endmenu 2498 2499 2500menu "Bus options (PCI etc.)" 2501 2502config PCI 2503 bool "PCI support" 2504 default y 2505 ---help--- 2506 Find out whether you have a PCI motherboard. PCI is the name of a 2507 bus system, i.e. the way the CPU talks to the other stuff inside 2508 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2509 VESA. If you have PCI, say Y, otherwise N. 2510 2511choice 2512 prompt "PCI access mode" 2513 depends on X86_32 && PCI 2514 default PCI_GOANY 2515 ---help--- 2516 On PCI systems, the BIOS can be used to detect the PCI devices and 2517 determine their configuration. However, some old PCI motherboards 2518 have BIOS bugs and may crash if this is done. Also, some embedded 2519 PCI-based systems don't have any BIOS at all. Linux can also try to 2520 detect the PCI hardware directly without using the BIOS. 2521 2522 With this option, you can specify how Linux should detect the 2523 PCI devices. If you choose "BIOS", the BIOS will be used, 2524 if you choose "Direct", the BIOS won't be used, and if you 2525 choose "MMConfig", then PCI Express MMCONFIG will be used. 2526 If you choose "Any", the kernel will try MMCONFIG, then the 2527 direct access method and falls back to the BIOS if that doesn't 2528 work. If unsure, go with the default, which is "Any". 2529 2530config PCI_GOBIOS 2531 bool "BIOS" 2532 2533config PCI_GOMMCONFIG 2534 bool "MMConfig" 2535 2536config PCI_GODIRECT 2537 bool "Direct" 2538 2539config PCI_GOOLPC 2540 bool "OLPC XO-1" 2541 depends on OLPC 2542 2543config PCI_GOANY 2544 bool "Any" 2545 2546endchoice 2547 2548config PCI_BIOS 2549 def_bool y 2550 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2551 2552# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2553config PCI_DIRECT 2554 def_bool y 2555 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2556 2557config PCI_MMCONFIG 2558 def_bool y 2559 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2560 2561config PCI_OLPC 2562 def_bool y 2563 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2564 2565config PCI_XEN 2566 def_bool y 2567 depends on PCI && XEN 2568 select SWIOTLB_XEN 2569 2570config PCI_DOMAINS 2571 def_bool y 2572 depends on PCI 2573 2574config PCI_MMCONFIG 2575 bool "Support mmconfig PCI config space access" 2576 depends on X86_64 && PCI && ACPI 2577 2578config PCI_CNB20LE_QUIRK 2579 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2580 depends on PCI 2581 help 2582 Read the PCI windows out of the CNB20LE host bridge. This allows 2583 PCI hotplug to work on systems with the CNB20LE chipset which do 2584 not have ACPI. 2585 2586 There's no public spec for this chipset, and this functionality 2587 is known to be incomplete. 2588 2589 You should say N unless you know you need this. 2590 2591source "drivers/pci/Kconfig" 2592 2593config ISA_BUS 2594 bool "ISA-style bus support on modern systems" if EXPERT 2595 select ISA_BUS_API 2596 help 2597 Enables ISA-style drivers on modern systems. This is necessary to 2598 support PC/104 devices on X86_64 platforms. 2599 2600 If unsure, say N. 2601 2602# x86_64 have no ISA slots, but can have ISA-style DMA. 2603config ISA_DMA_API 2604 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2605 default y 2606 help 2607 Enables ISA-style DMA support for devices requiring such controllers. 2608 If unsure, say Y. 2609 2610if X86_32 2611 2612config ISA 2613 bool "ISA support" 2614 ---help--- 2615 Find out whether you have ISA slots on your motherboard. ISA is the 2616 name of a bus system, i.e. the way the CPU talks to the other stuff 2617 inside your box. Other bus systems are PCI, EISA, MicroChannel 2618 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2619 newer boards don't support it. If you have ISA, say Y, otherwise N. 2620 2621config EISA 2622 bool "EISA support" 2623 depends on ISA 2624 ---help--- 2625 The Extended Industry Standard Architecture (EISA) bus was 2626 developed as an open alternative to the IBM MicroChannel bus. 2627 2628 The EISA bus provided some of the features of the IBM MicroChannel 2629 bus while maintaining backward compatibility with cards made for 2630 the older ISA bus. The EISA bus saw limited use between 1988 and 2631 1995 when it was made obsolete by the PCI bus. 2632 2633 Say Y here if you are building a kernel for an EISA-based machine. 2634 2635 Otherwise, say N. 2636 2637source "drivers/eisa/Kconfig" 2638 2639config SCx200 2640 tristate "NatSemi SCx200 support" 2641 ---help--- 2642 This provides basic support for National Semiconductor's 2643 (now AMD's) Geode processors. The driver probes for the 2644 PCI-IDs of several on-chip devices, so its a good dependency 2645 for other scx200_* drivers. 2646 2647 If compiled as a module, the driver is named scx200. 2648 2649config SCx200HR_TIMER 2650 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2651 depends on SCx200 2652 default y 2653 ---help--- 2654 This driver provides a clocksource built upon the on-chip 2655 27MHz high-resolution timer. Its also a workaround for 2656 NSC Geode SC-1100's buggy TSC, which loses time when the 2657 processor goes idle (as is done by the scheduler). The 2658 other workaround is idle=poll boot option. 2659 2660config OLPC 2661 bool "One Laptop Per Child support" 2662 depends on !X86_PAE 2663 select GPIOLIB 2664 select OF 2665 select OF_PROMTREE 2666 select IRQ_DOMAIN 2667 ---help--- 2668 Add support for detecting the unique features of the OLPC 2669 XO hardware. 2670 2671config OLPC_XO1_PM 2672 bool "OLPC XO-1 Power Management" 2673 depends on OLPC && MFD_CS5535 && PM_SLEEP 2674 select MFD_CORE 2675 ---help--- 2676 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2677 2678config OLPC_XO1_RTC 2679 bool "OLPC XO-1 Real Time Clock" 2680 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2681 ---help--- 2682 Add support for the XO-1 real time clock, which can be used as a 2683 programmable wakeup source. 2684 2685config OLPC_XO1_SCI 2686 bool "OLPC XO-1 SCI extras" 2687 depends on OLPC && OLPC_XO1_PM 2688 depends on INPUT=y 2689 select POWER_SUPPLY 2690 select GPIO_CS5535 2691 select MFD_CORE 2692 ---help--- 2693 Add support for SCI-based features of the OLPC XO-1 laptop: 2694 - EC-driven system wakeups 2695 - Power button 2696 - Ebook switch 2697 - Lid switch 2698 - AC adapter status updates 2699 - Battery status updates 2700 2701config OLPC_XO15_SCI 2702 bool "OLPC XO-1.5 SCI extras" 2703 depends on OLPC && ACPI 2704 select POWER_SUPPLY 2705 ---help--- 2706 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2707 - EC-driven system wakeups 2708 - AC adapter status updates 2709 - Battery status updates 2710 2711config ALIX 2712 bool "PCEngines ALIX System Support (LED setup)" 2713 select GPIOLIB 2714 ---help--- 2715 This option enables system support for the PCEngines ALIX. 2716 At present this just sets up LEDs for GPIO control on 2717 ALIX2/3/6 boards. However, other system specific setup should 2718 get added here. 2719 2720 Note: You must still enable the drivers for GPIO and LED support 2721 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2722 2723 Note: You have to set alix.force=1 for boards with Award BIOS. 2724 2725config NET5501 2726 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2727 select GPIOLIB 2728 ---help--- 2729 This option enables system support for the Soekris Engineering net5501. 2730 2731config GEOS 2732 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2733 select GPIOLIB 2734 depends on DMI 2735 ---help--- 2736 This option enables system support for the Traverse Technologies GEOS. 2737 2738config TS5500 2739 bool "Technologic Systems TS-5500 platform support" 2740 depends on MELAN 2741 select CHECK_SIGNATURE 2742 select NEW_LEDS 2743 select LEDS_CLASS 2744 ---help--- 2745 This option enables system support for the Technologic Systems TS-5500. 2746 2747endif # X86_32 2748 2749config AMD_NB 2750 def_bool y 2751 depends on CPU_SUP_AMD && PCI 2752 2753source "drivers/pcmcia/Kconfig" 2754 2755config RAPIDIO 2756 tristate "RapidIO support" 2757 depends on PCI 2758 default n 2759 help 2760 If enabled this option will include drivers and the core 2761 infrastructure code to support RapidIO interconnect devices. 2762 2763source "drivers/rapidio/Kconfig" 2764 2765config X86_SYSFB 2766 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2767 help 2768 Firmwares often provide initial graphics framebuffers so the BIOS, 2769 bootloader or kernel can show basic video-output during boot for 2770 user-guidance and debugging. Historically, x86 used the VESA BIOS 2771 Extensions and EFI-framebuffers for this, which are mostly limited 2772 to x86. 2773 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2774 framebuffers so the new generic system-framebuffer drivers can be 2775 used on x86. If the framebuffer is not compatible with the generic 2776 modes, it is adverticed as fallback platform framebuffer so legacy 2777 drivers like efifb, vesafb and uvesafb can pick it up. 2778 If this option is not selected, all system framebuffers are always 2779 marked as fallback platform framebuffers as usual. 2780 2781 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2782 not be able to pick up generic system framebuffers if this option 2783 is selected. You are highly encouraged to enable simplefb as 2784 replacement if you select this option. simplefb can correctly deal 2785 with generic system framebuffers. But you should still keep vesafb 2786 and others enabled as fallback if a system framebuffer is 2787 incompatible with simplefb. 2788 2789 If unsure, say Y. 2790 2791endmenu 2792 2793 2794menu "Executable file formats / Emulations" 2795 2796source "fs/Kconfig.binfmt" 2797 2798config IA32_EMULATION 2799 bool "IA32 Emulation" 2800 depends on X86_64 2801 select ARCH_WANT_OLD_COMPAT_IPC 2802 select BINFMT_ELF 2803 select COMPAT_BINFMT_ELF 2804 select COMPAT_OLD_SIGACTION 2805 ---help--- 2806 Include code to run legacy 32-bit programs under a 2807 64-bit kernel. You should likely turn this on, unless you're 2808 100% sure that you don't have any 32-bit programs left. 2809 2810config IA32_AOUT 2811 tristate "IA32 a.out support" 2812 depends on IA32_EMULATION 2813 ---help--- 2814 Support old a.out binaries in the 32bit emulation. 2815 2816config X86_X32 2817 bool "x32 ABI for 64-bit mode" 2818 depends on X86_64 2819 ---help--- 2820 Include code to run binaries for the x32 native 32-bit ABI 2821 for 64-bit processors. An x32 process gets access to the 2822 full 64-bit register file and wide data path while leaving 2823 pointers at 32 bits for smaller memory footprint. 2824 2825 You will need a recent binutils (2.22 or later) with 2826 elf32_x86_64 support enabled to compile a kernel with this 2827 option set. 2828 2829config COMPAT_32 2830 def_bool y 2831 depends on IA32_EMULATION || X86_32 2832 select HAVE_UID16 2833 select OLD_SIGSUSPEND3 2834 2835config COMPAT 2836 def_bool y 2837 depends on IA32_EMULATION || X86_X32 2838 2839if COMPAT 2840config COMPAT_FOR_U64_ALIGNMENT 2841 def_bool y 2842 2843config SYSVIPC_COMPAT 2844 def_bool y 2845 depends on SYSVIPC 2846endif 2847 2848endmenu 2849 2850 2851config HAVE_ATOMIC_IOMAP 2852 def_bool y 2853 depends on X86_32 2854 2855config X86_DEV_DMA_OPS 2856 bool 2857 depends on X86_64 || STA2X11 2858 2859config X86_DMA_REMAP 2860 bool 2861 depends on STA2X11 2862 2863config HAVE_GENERIC_GUP 2864 def_bool y 2865 2866source "net/Kconfig" 2867 2868source "drivers/Kconfig" 2869 2870source "drivers/firmware/Kconfig" 2871 2872source "fs/Kconfig" 2873 2874source "arch/x86/Kconfig.debug" 2875 2876source "security/Kconfig" 2877 2878source "crypto/Kconfig" 2879 2880source "arch/x86/kvm/Kconfig" 2881 2882source "lib/Kconfig" 2883