1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if ARCH = "x86" 5 default ARCH != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_AOUT 18 select HAVE_GENERIC_DMA_COHERENT 19 select MODULES_USE_ELF_REL 20 select OLD_SIGACTION 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select X86_DEV_DMA_OPS 32 33# 34# Arch settings 35# 36# ( Note that options that are marked 'if X86_64' could in principle be 37# ported to 32-bit as well. ) 38# 39config X86 40 def_bool y 41 # 42 # Note: keep this list sorted alphabetically 43 # 44 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 45 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 46 select ANON_INODES 47 select ARCH_CLOCKSOURCE_DATA 48 select ARCH_DISCARD_MEMBLOCK 49 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 50 select ARCH_HAS_DEBUG_VIRTUAL 51 select ARCH_HAS_DEVMEM_IS_ALLOWED 52 select ARCH_HAS_ELF_RANDOMIZE 53 select ARCH_HAS_FAST_MULTIPLIER 54 select ARCH_HAS_FORTIFY_SOURCE 55 select ARCH_HAS_GCOV_PROFILE_ALL 56 select ARCH_HAS_KCOV if X86_64 57 select ARCH_HAS_PMEM_API if X86_64 58 # Causing hangs/crashes, see the commit that added this change for details. 59 select ARCH_HAS_REFCOUNT 60 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 61 select ARCH_HAS_SET_MEMORY 62 select ARCH_HAS_SG_CHAIN 63 select ARCH_HAS_STRICT_KERNEL_RWX 64 select ARCH_HAS_STRICT_MODULE_RWX 65 select ARCH_HAS_UBSAN_SANITIZE_ALL 66 select ARCH_HAS_ZONE_DEVICE if X86_64 67 select ARCH_HAVE_NMI_SAFE_CMPXCHG 68 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 69 select ARCH_MIGHT_HAVE_PC_PARPORT 70 select ARCH_MIGHT_HAVE_PC_SERIO 71 select ARCH_SUPPORTS_ATOMIC_RMW 72 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 73 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 74 select ARCH_USE_BUILTIN_BSWAP 75 select ARCH_USE_QUEUED_RWLOCKS 76 select ARCH_USE_QUEUED_SPINLOCKS 77 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 78 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 79 select ARCH_WANTS_THP_SWAP if X86_64 80 select BUILDTIME_EXTABLE_SORT 81 select CLKEVT_I8253 82 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 83 select CLOCKSOURCE_WATCHDOG 84 select DCACHE_WORD_ACCESS 85 select EDAC_ATOMIC_SCRUB 86 select EDAC_SUPPORT 87 select GENERIC_CLOCKEVENTS 88 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 89 select GENERIC_CLOCKEVENTS_MIN_ADJUST 90 select GENERIC_CMOS_UPDATE 91 select GENERIC_CPU_AUTOPROBE 92 select GENERIC_EARLY_IOREMAP 93 select GENERIC_FIND_FIRST_BIT 94 select GENERIC_IOMAP 95 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 96 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 97 select GENERIC_IRQ_MIGRATION if SMP 98 select GENERIC_IRQ_PROBE 99 select GENERIC_IRQ_RESERVATION_MODE 100 select GENERIC_IRQ_SHOW 101 select GENERIC_PENDING_IRQ if SMP 102 select GENERIC_SMP_IDLE_THREAD 103 select GENERIC_STRNCPY_FROM_USER 104 select GENERIC_STRNLEN_USER 105 select GENERIC_TIME_VSYSCALL 106 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 107 select HAVE_ACPI_APEI if ACPI 108 select HAVE_ACPI_APEI_NMI if ACPI 109 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 110 select HAVE_ARCH_AUDITSYSCALL 111 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 112 select HAVE_ARCH_JUMP_LABEL 113 select HAVE_ARCH_KASAN if X86_64 114 select HAVE_ARCH_KGDB 115 select HAVE_ARCH_MMAP_RND_BITS if MMU 116 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 117 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 118 select HAVE_ARCH_SECCOMP_FILTER 119 select HAVE_ARCH_TRACEHOOK 120 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 121 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 122 select HAVE_ARCH_VMAP_STACK if X86_64 123 select HAVE_ARCH_WITHIN_STACK_FRAMES 124 select HAVE_CC_STACKPROTECTOR 125 select HAVE_CMPXCHG_DOUBLE 126 select HAVE_CMPXCHG_LOCAL 127 select HAVE_CONTEXT_TRACKING if X86_64 128 select HAVE_COPY_THREAD_TLS 129 select HAVE_C_RECORDMCOUNT 130 select HAVE_DEBUG_KMEMLEAK 131 select HAVE_DEBUG_STACKOVERFLOW 132 select HAVE_DMA_API_DEBUG 133 select HAVE_DMA_CONTIGUOUS 134 select HAVE_DYNAMIC_FTRACE 135 select HAVE_DYNAMIC_FTRACE_WITH_REGS 136 select HAVE_EBPF_JIT if X86_64 137 select HAVE_EFFICIENT_UNALIGNED_ACCESS 138 select HAVE_EXIT_THREAD 139 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 140 select HAVE_FTRACE_MCOUNT_RECORD 141 select HAVE_FUNCTION_GRAPH_TRACER 142 select HAVE_FUNCTION_TRACER 143 select HAVE_GCC_PLUGINS 144 select HAVE_HW_BREAKPOINT 145 select HAVE_IDE 146 select HAVE_IOREMAP_PROT 147 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 148 select HAVE_IRQ_TIME_ACCOUNTING 149 select HAVE_KERNEL_BZIP2 150 select HAVE_KERNEL_GZIP 151 select HAVE_KERNEL_LZ4 152 select HAVE_KERNEL_LZMA 153 select HAVE_KERNEL_LZO 154 select HAVE_KERNEL_XZ 155 select HAVE_KPROBES 156 select HAVE_KPROBES_ON_FTRACE 157 select HAVE_KRETPROBES 158 select HAVE_KVM 159 select HAVE_LIVEPATCH if X86_64 160 select HAVE_MEMBLOCK 161 select HAVE_MEMBLOCK_NODE_MAP 162 select HAVE_MIXED_BREAKPOINTS_REGS 163 select HAVE_MOD_ARCH_SPECIFIC 164 select HAVE_NMI 165 select HAVE_OPROFILE 166 select HAVE_OPTPROBES 167 select HAVE_PCSPKR_PLATFORM 168 select HAVE_PERF_EVENTS 169 select HAVE_PERF_EVENTS_NMI 170 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 171 select HAVE_PERF_REGS 172 select HAVE_PERF_USER_STACK_DUMP 173 select HAVE_RCU_TABLE_FREE 174 select HAVE_REGS_AND_STACK_ACCESS_API 175 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 176 select HAVE_STACK_VALIDATION if X86_64 177 select HAVE_SYSCALL_TRACEPOINTS 178 select HAVE_UNSTABLE_SCHED_CLOCK 179 select HAVE_USER_RETURN_NOTIFIER 180 select IRQ_FORCED_THREADING 181 select PCI_LOCKLESS_CONFIG 182 select PERF_EVENTS 183 select RTC_LIB 184 select RTC_MC146818_LIB 185 select SPARSE_IRQ 186 select SRCU 187 select SYSCTL_EXCEPTION_TRACE 188 select THREAD_INFO_IN_TASK 189 select USER_STACKTRACE_SUPPORT 190 select VIRT_TO_BUS 191 select X86_FEATURE_NAMES if PROC_FS 192 193config INSTRUCTION_DECODER 194 def_bool y 195 depends on KPROBES || PERF_EVENTS || UPROBES 196 197config OUTPUT_FORMAT 198 string 199 default "elf32-i386" if X86_32 200 default "elf64-x86-64" if X86_64 201 202config ARCH_DEFCONFIG 203 string 204 default "arch/x86/configs/i386_defconfig" if X86_32 205 default "arch/x86/configs/x86_64_defconfig" if X86_64 206 207config LOCKDEP_SUPPORT 208 def_bool y 209 210config STACKTRACE_SUPPORT 211 def_bool y 212 213config MMU 214 def_bool y 215 216config ARCH_MMAP_RND_BITS_MIN 217 default 28 if 64BIT 218 default 8 219 220config ARCH_MMAP_RND_BITS_MAX 221 default 32 if 64BIT 222 default 16 223 224config ARCH_MMAP_RND_COMPAT_BITS_MIN 225 default 8 226 227config ARCH_MMAP_RND_COMPAT_BITS_MAX 228 default 16 229 230config SBUS 231 bool 232 233config NEED_DMA_MAP_STATE 234 def_bool y 235 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 236 237config NEED_SG_DMA_LENGTH 238 def_bool y 239 240config GENERIC_ISA_DMA 241 def_bool y 242 depends on ISA_DMA_API 243 244config GENERIC_BUG 245 def_bool y 246 depends on BUG 247 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 248 249config GENERIC_BUG_RELATIVE_POINTERS 250 bool 251 252config GENERIC_HWEIGHT 253 def_bool y 254 255config ARCH_MAY_HAVE_PC_FDC 256 def_bool y 257 depends on ISA_DMA_API 258 259config RWSEM_XCHGADD_ALGORITHM 260 def_bool y 261 262config GENERIC_CALIBRATE_DELAY 263 def_bool y 264 265config ARCH_HAS_CPU_RELAX 266 def_bool y 267 268config ARCH_HAS_CACHE_LINE_SIZE 269 def_bool y 270 271config HAVE_SETUP_PER_CPU_AREA 272 def_bool y 273 274config NEED_PER_CPU_EMBED_FIRST_CHUNK 275 def_bool y 276 277config NEED_PER_CPU_PAGE_FIRST_CHUNK 278 def_bool y 279 280config ARCH_HIBERNATION_POSSIBLE 281 def_bool y 282 283config ARCH_SUSPEND_POSSIBLE 284 def_bool y 285 286config ARCH_WANT_HUGE_PMD_SHARE 287 def_bool y 288 289config ARCH_WANT_GENERAL_HUGETLB 290 def_bool y 291 292config ZONE_DMA32 293 def_bool y if X86_64 294 295config AUDIT_ARCH 296 def_bool y if X86_64 297 298config ARCH_SUPPORTS_OPTIMIZED_INLINING 299 def_bool y 300 301config ARCH_SUPPORTS_DEBUG_PAGEALLOC 302 def_bool y 303 304config KASAN_SHADOW_OFFSET 305 hex 306 depends on KASAN 307 default 0xdffffc0000000000 308 309config HAVE_INTEL_TXT 310 def_bool y 311 depends on INTEL_IOMMU && ACPI 312 313config X86_32_SMP 314 def_bool y 315 depends on X86_32 && SMP 316 317config X86_64_SMP 318 def_bool y 319 depends on X86_64 && SMP 320 321config X86_32_LAZY_GS 322 def_bool y 323 depends on X86_32 && !CC_STACKPROTECTOR 324 325config ARCH_SUPPORTS_UPROBES 326 def_bool y 327 328config FIX_EARLYCON_MEM 329 def_bool y 330 331config PGTABLE_LEVELS 332 int 333 default 5 if X86_5LEVEL 334 default 4 if X86_64 335 default 3 if X86_PAE 336 default 2 337 338source "init/Kconfig" 339source "kernel/Kconfig.freezer" 340 341menu "Processor type and features" 342 343config ZONE_DMA 344 bool "DMA memory allocation support" if EXPERT 345 default y 346 help 347 DMA memory allocation support allows devices with less than 32-bit 348 addressing to allocate within the first 16MB of address space. 349 Disable if no such devices will be used. 350 351 If unsure, say Y. 352 353config SMP 354 bool "Symmetric multi-processing support" 355 ---help--- 356 This enables support for systems with more than one CPU. If you have 357 a system with only one CPU, say N. If you have a system with more 358 than one CPU, say Y. 359 360 If you say N here, the kernel will run on uni- and multiprocessor 361 machines, but will use only one CPU of a multiprocessor machine. If 362 you say Y here, the kernel will run on many, but not all, 363 uniprocessor machines. On a uniprocessor machine, the kernel 364 will run faster if you say N here. 365 366 Note that if you say Y here and choose architecture "586" or 367 "Pentium" under "Processor family", the kernel will not work on 486 368 architectures. Similarly, multiprocessor kernels for the "PPro" 369 architecture may not work on all Pentium based boards. 370 371 People using multiprocessor machines who say Y here should also say 372 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 373 Management" code will be disabled if you say Y here. 374 375 See also <file:Documentation/x86/i386/IO-APIC.txt>, 376 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 377 <http://www.tldp.org/docs.html#howto>. 378 379 If you don't know what to do here, say N. 380 381config X86_FEATURE_NAMES 382 bool "Processor feature human-readable names" if EMBEDDED 383 default y 384 ---help--- 385 This option compiles in a table of x86 feature bits and corresponding 386 names. This is required to support /proc/cpuinfo and a few kernel 387 messages. You can disable this to save space, at the expense of 388 making those few kernel messages show numeric feature bits instead. 389 390 If in doubt, say Y. 391 392config X86_FAST_FEATURE_TESTS 393 bool "Fast CPU feature tests" if EMBEDDED 394 default y 395 ---help--- 396 Some fast-paths in the kernel depend on the capabilities of the CPU. 397 Say Y here for the kernel to patch in the appropriate code at runtime 398 based on the capabilities of the CPU. The infrastructure for patching 399 code at runtime takes up some additional space; space-constrained 400 embedded systems may wish to say N here to produce smaller, slightly 401 slower code. 402 403config X86_X2APIC 404 bool "Support x2apic" 405 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 406 ---help--- 407 This enables x2apic support on CPUs that have this feature. 408 409 This allows 32-bit apic IDs (so it can support very large systems), 410 and accesses the local apic via MSRs not via mmio. 411 412 If you don't know what to do here, say N. 413 414config X86_MPPARSE 415 bool "Enable MPS table" if ACPI || SFI 416 default y 417 depends on X86_LOCAL_APIC 418 ---help--- 419 For old smp systems that do not have proper acpi support. Newer systems 420 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 421 422config X86_BIGSMP 423 bool "Support for big SMP systems with more than 8 CPUs" 424 depends on X86_32 && SMP 425 ---help--- 426 This option is needed for the systems that have more than 8 CPUs 427 428config GOLDFISH 429 def_bool y 430 depends on X86_GOLDFISH 431 432config INTEL_RDT 433 bool "Intel Resource Director Technology support" 434 default n 435 depends on X86 && CPU_SUP_INTEL 436 select KERNFS 437 help 438 Select to enable resource allocation and monitoring which are 439 sub-features of Intel Resource Director Technology(RDT). More 440 information about RDT can be found in the Intel x86 441 Architecture Software Developer Manual. 442 443 Say N if unsure. 444 445if X86_32 446config X86_EXTENDED_PLATFORM 447 bool "Support for extended (non-PC) x86 platforms" 448 default y 449 ---help--- 450 If you disable this option then the kernel will only support 451 standard PC platforms. (which covers the vast majority of 452 systems out there.) 453 454 If you enable this option then you'll be able to select support 455 for the following (non-PC) 32 bit x86 platforms: 456 Goldfish (Android emulator) 457 AMD Elan 458 RDC R-321x SoC 459 SGI 320/540 (Visual Workstation) 460 STA2X11-based (e.g. Northville) 461 Moorestown MID devices 462 463 If you have one of these systems, or if you want to build a 464 generic distribution kernel, say Y here - otherwise say N. 465endif 466 467if X86_64 468config X86_EXTENDED_PLATFORM 469 bool "Support for extended (non-PC) x86 platforms" 470 default y 471 ---help--- 472 If you disable this option then the kernel will only support 473 standard PC platforms. (which covers the vast majority of 474 systems out there.) 475 476 If you enable this option then you'll be able to select support 477 for the following (non-PC) 64 bit x86 platforms: 478 Numascale NumaChip 479 ScaleMP vSMP 480 SGI Ultraviolet 481 482 If you have one of these systems, or if you want to build a 483 generic distribution kernel, say Y here - otherwise say N. 484endif 485# This is an alphabetically sorted list of 64 bit extended platforms 486# Please maintain the alphabetic order if and when there are additions 487config X86_NUMACHIP 488 bool "Numascale NumaChip" 489 depends on X86_64 490 depends on X86_EXTENDED_PLATFORM 491 depends on NUMA 492 depends on SMP 493 depends on X86_X2APIC 494 depends on PCI_MMCONFIG 495 ---help--- 496 Adds support for Numascale NumaChip large-SMP systems. Needed to 497 enable more than ~168 cores. 498 If you don't have one of these, you should say N here. 499 500config X86_VSMP 501 bool "ScaleMP vSMP" 502 select HYPERVISOR_GUEST 503 select PARAVIRT 504 depends on X86_64 && PCI 505 depends on X86_EXTENDED_PLATFORM 506 depends on SMP 507 ---help--- 508 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 509 supposed to run on these EM64T-based machines. Only choose this option 510 if you have one of these machines. 511 512config X86_UV 513 bool "SGI Ultraviolet" 514 depends on X86_64 515 depends on X86_EXTENDED_PLATFORM 516 depends on NUMA 517 depends on EFI 518 depends on X86_X2APIC 519 depends on PCI 520 ---help--- 521 This option is needed in order to support SGI Ultraviolet systems. 522 If you don't have one of these, you should say N here. 523 524# Following is an alphabetically sorted list of 32 bit extended platforms 525# Please maintain the alphabetic order if and when there are additions 526 527config X86_GOLDFISH 528 bool "Goldfish (Virtual Platform)" 529 depends on X86_EXTENDED_PLATFORM 530 ---help--- 531 Enable support for the Goldfish virtual platform used primarily 532 for Android development. Unless you are building for the Android 533 Goldfish emulator say N here. 534 535config X86_INTEL_CE 536 bool "CE4100 TV platform" 537 depends on PCI 538 depends on PCI_GODIRECT 539 depends on X86_IO_APIC 540 depends on X86_32 541 depends on X86_EXTENDED_PLATFORM 542 select X86_REBOOTFIXUPS 543 select OF 544 select OF_EARLY_FLATTREE 545 ---help--- 546 Select for the Intel CE media processor (CE4100) SOC. 547 This option compiles in support for the CE4100 SOC for settop 548 boxes and media devices. 549 550config X86_INTEL_MID 551 bool "Intel MID platform support" 552 depends on X86_EXTENDED_PLATFORM 553 depends on X86_PLATFORM_DEVICES 554 depends on PCI 555 depends on X86_64 || (PCI_GOANY && X86_32) 556 depends on X86_IO_APIC 557 select SFI 558 select I2C 559 select DW_APB_TIMER 560 select APB_TIMER 561 select INTEL_SCU_IPC 562 select MFD_INTEL_MSIC 563 ---help--- 564 Select to build a kernel capable of supporting Intel MID (Mobile 565 Internet Device) platform systems which do not have the PCI legacy 566 interfaces. If you are building for a PC class system say N here. 567 568 Intel MID platforms are based on an Intel processor and chipset which 569 consume less power than most of the x86 derivatives. 570 571config X86_INTEL_QUARK 572 bool "Intel Quark platform support" 573 depends on X86_32 574 depends on X86_EXTENDED_PLATFORM 575 depends on X86_PLATFORM_DEVICES 576 depends on X86_TSC 577 depends on PCI 578 depends on PCI_GOANY 579 depends on X86_IO_APIC 580 select IOSF_MBI 581 select INTEL_IMR 582 select COMMON_CLK 583 ---help--- 584 Select to include support for Quark X1000 SoC. 585 Say Y here if you have a Quark based system such as the Arduino 586 compatible Intel Galileo. 587 588config X86_INTEL_LPSS 589 bool "Intel Low Power Subsystem Support" 590 depends on X86 && ACPI 591 select COMMON_CLK 592 select PINCTRL 593 select IOSF_MBI 594 ---help--- 595 Select to build support for Intel Low Power Subsystem such as 596 found on Intel Lynxpoint PCH. Selecting this option enables 597 things like clock tree (common clock framework) and pincontrol 598 which are needed by the LPSS peripheral drivers. 599 600config X86_AMD_PLATFORM_DEVICE 601 bool "AMD ACPI2Platform devices support" 602 depends on ACPI 603 select COMMON_CLK 604 select PINCTRL 605 ---help--- 606 Select to interpret AMD specific ACPI device to platform device 607 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 608 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 609 implemented under PINCTRL subsystem. 610 611config IOSF_MBI 612 tristate "Intel SoC IOSF Sideband support for SoC platforms" 613 depends on PCI 614 ---help--- 615 This option enables sideband register access support for Intel SoC 616 platforms. On these platforms the IOSF sideband is used in lieu of 617 MSR's for some register accesses, mostly but not limited to thermal 618 and power. Drivers may query the availability of this device to 619 determine if they need the sideband in order to work on these 620 platforms. The sideband is available on the following SoC products. 621 This list is not meant to be exclusive. 622 - BayTrail 623 - Braswell 624 - Quark 625 626 You should say Y if you are running a kernel on one of these SoC's. 627 628config IOSF_MBI_DEBUG 629 bool "Enable IOSF sideband access through debugfs" 630 depends on IOSF_MBI && DEBUG_FS 631 ---help--- 632 Select this option to expose the IOSF sideband access registers (MCR, 633 MDR, MCRX) through debugfs to write and read register information from 634 different units on the SoC. This is most useful for obtaining device 635 state information for debug and analysis. As this is a general access 636 mechanism, users of this option would have specific knowledge of the 637 device they want to access. 638 639 If you don't require the option or are in doubt, say N. 640 641config X86_RDC321X 642 bool "RDC R-321x SoC" 643 depends on X86_32 644 depends on X86_EXTENDED_PLATFORM 645 select M486 646 select X86_REBOOTFIXUPS 647 ---help--- 648 This option is needed for RDC R-321x system-on-chip, also known 649 as R-8610-(G). 650 If you don't have one of these chips, you should say N here. 651 652config X86_32_NON_STANDARD 653 bool "Support non-standard 32-bit SMP architectures" 654 depends on X86_32 && SMP 655 depends on X86_EXTENDED_PLATFORM 656 ---help--- 657 This option compiles in the bigsmp and STA2X11 default 658 subarchitectures. It is intended for a generic binary 659 kernel. If you select them all, kernel will probe it one by 660 one and will fallback to default. 661 662# Alphabetically sorted list of Non standard 32 bit platforms 663 664config X86_SUPPORTS_MEMORY_FAILURE 665 def_bool y 666 # MCE code calls memory_failure(): 667 depends on X86_MCE 668 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 669 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 670 depends on X86_64 || !SPARSEMEM 671 select ARCH_SUPPORTS_MEMORY_FAILURE 672 673config STA2X11 674 bool "STA2X11 Companion Chip Support" 675 depends on X86_32_NON_STANDARD && PCI 676 select X86_DEV_DMA_OPS 677 select X86_DMA_REMAP 678 select SWIOTLB 679 select MFD_STA2X11 680 select GPIOLIB 681 default n 682 ---help--- 683 This adds support for boards based on the STA2X11 IO-Hub, 684 a.k.a. "ConneXt". The chip is used in place of the standard 685 PC chipset, so all "standard" peripherals are missing. If this 686 option is selected the kernel will still be able to boot on 687 standard PC machines. 688 689config X86_32_IRIS 690 tristate "Eurobraille/Iris poweroff module" 691 depends on X86_32 692 ---help--- 693 The Iris machines from EuroBraille do not have APM or ACPI support 694 to shut themselves down properly. A special I/O sequence is 695 needed to do so, which is what this module does at 696 kernel shutdown. 697 698 This is only for Iris machines from EuroBraille. 699 700 If unused, say N. 701 702config SCHED_OMIT_FRAME_POINTER 703 def_bool y 704 prompt "Single-depth WCHAN output" 705 depends on X86 706 ---help--- 707 Calculate simpler /proc/<PID>/wchan values. If this option 708 is disabled then wchan values will recurse back to the 709 caller function. This provides more accurate wchan values, 710 at the expense of slightly more scheduling overhead. 711 712 If in doubt, say "Y". 713 714menuconfig HYPERVISOR_GUEST 715 bool "Linux guest support" 716 ---help--- 717 Say Y here to enable options for running Linux under various hyper- 718 visors. This option enables basic hypervisor detection and platform 719 setup. 720 721 If you say N, all options in this submenu will be skipped and 722 disabled, and Linux guest support won't be built in. 723 724if HYPERVISOR_GUEST 725 726config PARAVIRT 727 bool "Enable paravirtualization code" 728 ---help--- 729 This changes the kernel so it can modify itself when it is run 730 under a hypervisor, potentially improving performance significantly 731 over full virtualization. However, when run without a hypervisor 732 the kernel is theoretically slower and slightly larger. 733 734config PARAVIRT_DEBUG 735 bool "paravirt-ops debugging" 736 depends on PARAVIRT && DEBUG_KERNEL 737 ---help--- 738 Enable to debug paravirt_ops internals. Specifically, BUG if 739 a paravirt_op is missing when it is called. 740 741config PARAVIRT_SPINLOCKS 742 bool "Paravirtualization layer for spinlocks" 743 depends on PARAVIRT && SMP 744 ---help--- 745 Paravirtualized spinlocks allow a pvops backend to replace the 746 spinlock implementation with something virtualization-friendly 747 (for example, block the virtual CPU rather than spinning). 748 749 It has a minimal impact on native kernels and gives a nice performance 750 benefit on paravirtualized KVM / Xen kernels. 751 752 If you are unsure how to answer this question, answer Y. 753 754config QUEUED_LOCK_STAT 755 bool "Paravirt queued spinlock statistics" 756 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 757 ---help--- 758 Enable the collection of statistical data on the slowpath 759 behavior of paravirtualized queued spinlocks and report 760 them on debugfs. 761 762source "arch/x86/xen/Kconfig" 763 764config KVM_GUEST 765 bool "KVM Guest support (including kvmclock)" 766 depends on PARAVIRT 767 select PARAVIRT_CLOCK 768 default y 769 ---help--- 770 This option enables various optimizations for running under the KVM 771 hypervisor. It includes a paravirtualized clock, so that instead 772 of relying on a PIT (or probably other) emulation by the 773 underlying device model, the host provides the guest with 774 timing infrastructure such as time of day, and system time 775 776config KVM_DEBUG_FS 777 bool "Enable debug information for KVM Guests in debugfs" 778 depends on KVM_GUEST && DEBUG_FS 779 default n 780 ---help--- 781 This option enables collection of various statistics for KVM guest. 782 Statistics are displayed in debugfs filesystem. Enabling this option 783 may incur significant overhead. 784 785config PARAVIRT_TIME_ACCOUNTING 786 bool "Paravirtual steal time accounting" 787 depends on PARAVIRT 788 default n 789 ---help--- 790 Select this option to enable fine granularity task steal time 791 accounting. Time spent executing other tasks in parallel with 792 the current vCPU is discounted from the vCPU power. To account for 793 that, there can be a small performance impact. 794 795 If in doubt, say N here. 796 797config PARAVIRT_CLOCK 798 bool 799 800endif #HYPERVISOR_GUEST 801 802config NO_BOOTMEM 803 def_bool y 804 805source "arch/x86/Kconfig.cpu" 806 807config HPET_TIMER 808 def_bool X86_64 809 prompt "HPET Timer Support" if X86_32 810 ---help--- 811 Use the IA-PC HPET (High Precision Event Timer) to manage 812 time in preference to the PIT and RTC, if a HPET is 813 present. 814 HPET is the next generation timer replacing legacy 8254s. 815 The HPET provides a stable time base on SMP 816 systems, unlike the TSC, but it is more expensive to access, 817 as it is off-chip. The interface used is documented 818 in the HPET spec, revision 1. 819 820 You can safely choose Y here. However, HPET will only be 821 activated if the platform and the BIOS support this feature. 822 Otherwise the 8254 will be used for timing services. 823 824 Choose N to continue using the legacy 8254 timer. 825 826config HPET_EMULATE_RTC 827 def_bool y 828 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 829 830config APB_TIMER 831 def_bool y if X86_INTEL_MID 832 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 833 select DW_APB_TIMER 834 depends on X86_INTEL_MID && SFI 835 help 836 APB timer is the replacement for 8254, HPET on X86 MID platforms. 837 The APBT provides a stable time base on SMP 838 systems, unlike the TSC, but it is more expensive to access, 839 as it is off-chip. APB timers are always running regardless of CPU 840 C states, they are used as per CPU clockevent device when possible. 841 842# Mark as expert because too many people got it wrong. 843# The code disables itself when not needed. 844config DMI 845 default y 846 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 847 bool "Enable DMI scanning" if EXPERT 848 ---help--- 849 Enabled scanning of DMI to identify machine quirks. Say Y 850 here unless you have verified that your setup is not 851 affected by entries in the DMI blacklist. Required by PNP 852 BIOS code. 853 854config GART_IOMMU 855 bool "Old AMD GART IOMMU support" 856 select SWIOTLB 857 depends on X86_64 && PCI && AMD_NB 858 ---help--- 859 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 860 GART based hardware IOMMUs. 861 862 The GART supports full DMA access for devices with 32-bit access 863 limitations, on systems with more than 3 GB. This is usually needed 864 for USB, sound, many IDE/SATA chipsets and some other devices. 865 866 Newer systems typically have a modern AMD IOMMU, supported via 867 the CONFIG_AMD_IOMMU=y config option. 868 869 In normal configurations this driver is only active when needed: 870 there's more than 3 GB of memory and the system contains a 871 32-bit limited device. 872 873 If unsure, say Y. 874 875config CALGARY_IOMMU 876 bool "IBM Calgary IOMMU support" 877 select SWIOTLB 878 depends on X86_64 && PCI 879 ---help--- 880 Support for hardware IOMMUs in IBM's xSeries x366 and x460 881 systems. Needed to run systems with more than 3GB of memory 882 properly with 32-bit PCI devices that do not support DAC 883 (Double Address Cycle). Calgary also supports bus level 884 isolation, where all DMAs pass through the IOMMU. This 885 prevents them from going anywhere except their intended 886 destination. This catches hard-to-find kernel bugs and 887 mis-behaving drivers and devices that do not use the DMA-API 888 properly to set up their DMA buffers. The IOMMU can be 889 turned off at boot time with the iommu=off parameter. 890 Normally the kernel will make the right choice by itself. 891 If unsure, say Y. 892 893config CALGARY_IOMMU_ENABLED_BY_DEFAULT 894 def_bool y 895 prompt "Should Calgary be enabled by default?" 896 depends on CALGARY_IOMMU 897 ---help--- 898 Should Calgary be enabled by default? if you choose 'y', Calgary 899 will be used (if it exists). If you choose 'n', Calgary will not be 900 used even if it exists. If you choose 'n' and would like to use 901 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 902 If unsure, say Y. 903 904# need this always selected by IOMMU for the VIA workaround 905config SWIOTLB 906 def_bool y if X86_64 907 ---help--- 908 Support for software bounce buffers used on x86-64 systems 909 which don't have a hardware IOMMU. Using this PCI devices 910 which can only access 32-bits of memory can be used on systems 911 with more than 3 GB of memory. 912 If unsure, say Y. 913 914config IOMMU_HELPER 915 def_bool y 916 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 917 918config MAXSMP 919 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 920 depends on X86_64 && SMP && DEBUG_KERNEL 921 select CPUMASK_OFFSTACK 922 ---help--- 923 Enable maximum number of CPUS and NUMA Nodes for this architecture. 924 If unsure, say N. 925 926config NR_CPUS 927 int "Maximum number of CPUs" if SMP && !MAXSMP 928 range 2 8 if SMP && X86_32 && !X86_BIGSMP 929 range 2 64 if SMP && X86_32 && X86_BIGSMP 930 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64 931 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 932 default "1" if !SMP 933 default "8192" if MAXSMP 934 default "32" if SMP && X86_BIGSMP 935 default "8" if SMP && X86_32 936 default "64" if SMP 937 ---help--- 938 This allows you to specify the maximum number of CPUs which this 939 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 940 supported value is 8192, otherwise the maximum value is 512. The 941 minimum value which makes sense is 2. 942 943 This is purely to save memory - each supported CPU adds 944 approximately eight kilobytes to the kernel image. 945 946config SCHED_SMT 947 bool "SMT (Hyperthreading) scheduler support" 948 depends on SMP 949 ---help--- 950 SMT scheduler support improves the CPU scheduler's decision making 951 when dealing with Intel Pentium 4 chips with HyperThreading at a 952 cost of slightly increased overhead in some places. If unsure say 953 N here. 954 955config SCHED_MC 956 def_bool y 957 prompt "Multi-core scheduler support" 958 depends on SMP 959 ---help--- 960 Multi-core scheduler support improves the CPU scheduler's decision 961 making when dealing with multi-core CPU chips at a cost of slightly 962 increased overhead in some places. If unsure say N here. 963 964config SCHED_MC_PRIO 965 bool "CPU core priorities scheduler support" 966 depends on SCHED_MC && CPU_SUP_INTEL 967 select X86_INTEL_PSTATE 968 select CPU_FREQ 969 default y 970 ---help--- 971 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 972 core ordering determined at manufacturing time, which allows 973 certain cores to reach higher turbo frequencies (when running 974 single threaded workloads) than others. 975 976 Enabling this kernel feature teaches the scheduler about 977 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 978 scheduler's CPU selection logic accordingly, so that higher 979 overall system performance can be achieved. 980 981 This feature will have no effect on CPUs without this feature. 982 983 If unsure say Y here. 984 985source "kernel/Kconfig.preempt" 986 987config UP_LATE_INIT 988 def_bool y 989 depends on !SMP && X86_LOCAL_APIC 990 991config X86_UP_APIC 992 bool "Local APIC support on uniprocessors" if !PCI_MSI 993 default PCI_MSI 994 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 995 ---help--- 996 A local APIC (Advanced Programmable Interrupt Controller) is an 997 integrated interrupt controller in the CPU. If you have a single-CPU 998 system which has a processor with a local APIC, you can say Y here to 999 enable and use it. If you say Y here even though your machine doesn't 1000 have a local APIC, then the kernel will still run with no slowdown at 1001 all. The local APIC supports CPU-generated self-interrupts (timer, 1002 performance counters), and the NMI watchdog which detects hard 1003 lockups. 1004 1005config X86_UP_IOAPIC 1006 bool "IO-APIC support on uniprocessors" 1007 depends on X86_UP_APIC 1008 ---help--- 1009 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1010 SMP-capable replacement for PC-style interrupt controllers. Most 1011 SMP systems and many recent uniprocessor systems have one. 1012 1013 If you have a single-CPU system with an IO-APIC, you can say Y here 1014 to use it. If you say Y here even though your machine doesn't have 1015 an IO-APIC, then the kernel will still run with no slowdown at all. 1016 1017config X86_LOCAL_APIC 1018 def_bool y 1019 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1020 select IRQ_DOMAIN_HIERARCHY 1021 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1022 1023config X86_IO_APIC 1024 def_bool y 1025 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1026 1027config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1028 bool "Reroute for broken boot IRQs" 1029 depends on X86_IO_APIC 1030 ---help--- 1031 This option enables a workaround that fixes a source of 1032 spurious interrupts. This is recommended when threaded 1033 interrupt handling is used on systems where the generation of 1034 superfluous "boot interrupts" cannot be disabled. 1035 1036 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1037 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1038 kernel does during interrupt handling). On chipsets where this 1039 boot IRQ generation cannot be disabled, this workaround keeps 1040 the original IRQ line masked so that only the equivalent "boot 1041 IRQ" is delivered to the CPUs. The workaround also tells the 1042 kernel to set up the IRQ handler on the boot IRQ line. In this 1043 way only one interrupt is delivered to the kernel. Otherwise 1044 the spurious second interrupt may cause the kernel to bring 1045 down (vital) interrupt lines. 1046 1047 Only affects "broken" chipsets. Interrupt sharing may be 1048 increased on these systems. 1049 1050config X86_MCE 1051 bool "Machine Check / overheating reporting" 1052 select GENERIC_ALLOCATOR 1053 default y 1054 ---help--- 1055 Machine Check support allows the processor to notify the 1056 kernel if it detects a problem (e.g. overheating, data corruption). 1057 The action the kernel takes depends on the severity of the problem, 1058 ranging from warning messages to halting the machine. 1059 1060config X86_MCELOG_LEGACY 1061 bool "Support for deprecated /dev/mcelog character device" 1062 depends on X86_MCE 1063 ---help--- 1064 Enable support for /dev/mcelog which is needed by the old mcelog 1065 userspace logging daemon. Consider switching to the new generation 1066 rasdaemon solution. 1067 1068config X86_MCE_INTEL 1069 def_bool y 1070 prompt "Intel MCE features" 1071 depends on X86_MCE && X86_LOCAL_APIC 1072 ---help--- 1073 Additional support for intel specific MCE features such as 1074 the thermal monitor. 1075 1076config X86_MCE_AMD 1077 def_bool y 1078 prompt "AMD MCE features" 1079 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1080 ---help--- 1081 Additional support for AMD specific MCE features such as 1082 the DRAM Error Threshold. 1083 1084config X86_ANCIENT_MCE 1085 bool "Support for old Pentium 5 / WinChip machine checks" 1086 depends on X86_32 && X86_MCE 1087 ---help--- 1088 Include support for machine check handling on old Pentium 5 or WinChip 1089 systems. These typically need to be enabled explicitly on the command 1090 line. 1091 1092config X86_MCE_THRESHOLD 1093 depends on X86_MCE_AMD || X86_MCE_INTEL 1094 def_bool y 1095 1096config X86_MCE_INJECT 1097 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1098 tristate "Machine check injector support" 1099 ---help--- 1100 Provide support for injecting machine checks for testing purposes. 1101 If you don't know what a machine check is and you don't do kernel 1102 QA it is safe to say n. 1103 1104config X86_THERMAL_VECTOR 1105 def_bool y 1106 depends on X86_MCE_INTEL 1107 1108source "arch/x86/events/Kconfig" 1109 1110config X86_LEGACY_VM86 1111 bool "Legacy VM86 support" 1112 default n 1113 depends on X86_32 1114 ---help--- 1115 This option allows user programs to put the CPU into V8086 1116 mode, which is an 80286-era approximation of 16-bit real mode. 1117 1118 Some very old versions of X and/or vbetool require this option 1119 for user mode setting. Similarly, DOSEMU will use it if 1120 available to accelerate real mode DOS programs. However, any 1121 recent version of DOSEMU, X, or vbetool should be fully 1122 functional even without kernel VM86 support, as they will all 1123 fall back to software emulation. Nevertheless, if you are using 1124 a 16-bit DOS program where 16-bit performance matters, vm86 1125 mode might be faster than emulation and you might want to 1126 enable this option. 1127 1128 Note that any app that works on a 64-bit kernel is unlikely to 1129 need this option, as 64-bit kernels don't, and can't, support 1130 V8086 mode. This option is also unrelated to 16-bit protected 1131 mode and is not needed to run most 16-bit programs under Wine. 1132 1133 Enabling this option increases the complexity of the kernel 1134 and slows down exception handling a tiny bit. 1135 1136 If unsure, say N here. 1137 1138config VM86 1139 bool 1140 default X86_LEGACY_VM86 1141 1142config X86_16BIT 1143 bool "Enable support for 16-bit segments" if EXPERT 1144 default y 1145 depends on MODIFY_LDT_SYSCALL 1146 ---help--- 1147 This option is required by programs like Wine to run 16-bit 1148 protected mode legacy code on x86 processors. Disabling 1149 this option saves about 300 bytes on i386, or around 6K text 1150 plus 16K runtime memory on x86-64, 1151 1152config X86_ESPFIX32 1153 def_bool y 1154 depends on X86_16BIT && X86_32 1155 1156config X86_ESPFIX64 1157 def_bool y 1158 depends on X86_16BIT && X86_64 1159 1160config X86_VSYSCALL_EMULATION 1161 bool "Enable vsyscall emulation" if EXPERT 1162 default y 1163 depends on X86_64 1164 ---help--- 1165 This enables emulation of the legacy vsyscall page. Disabling 1166 it is roughly equivalent to booting with vsyscall=none, except 1167 that it will also disable the helpful warning if a program 1168 tries to use a vsyscall. With this option set to N, offending 1169 programs will just segfault, citing addresses of the form 1170 0xffffffffff600?00. 1171 1172 This option is required by many programs built before 2013, and 1173 care should be used even with newer programs if set to N. 1174 1175 Disabling this option saves about 7K of kernel size and 1176 possibly 4K of additional runtime pagetable memory. 1177 1178config TOSHIBA 1179 tristate "Toshiba Laptop support" 1180 depends on X86_32 1181 ---help--- 1182 This adds a driver to safely access the System Management Mode of 1183 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1184 not work on models with a Phoenix BIOS. The System Management Mode 1185 is used to set the BIOS and power saving options on Toshiba portables. 1186 1187 For information on utilities to make use of this driver see the 1188 Toshiba Linux utilities web site at: 1189 <http://www.buzzard.org.uk/toshiba/>. 1190 1191 Say Y if you intend to run this kernel on a Toshiba portable. 1192 Say N otherwise. 1193 1194config I8K 1195 tristate "Dell i8k legacy laptop support" 1196 select HWMON 1197 select SENSORS_DELL_SMM 1198 ---help--- 1199 This option enables legacy /proc/i8k userspace interface in hwmon 1200 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1201 temperature and allows controlling fan speeds of Dell laptops via 1202 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1203 it reports also power and hotkey status. For fan speed control is 1204 needed userspace package i8kutils. 1205 1206 Say Y if you intend to run this kernel on old Dell laptops or want to 1207 use userspace package i8kutils. 1208 Say N otherwise. 1209 1210config X86_REBOOTFIXUPS 1211 bool "Enable X86 board specific fixups for reboot" 1212 depends on X86_32 1213 ---help--- 1214 This enables chipset and/or board specific fixups to be done 1215 in order to get reboot to work correctly. This is only needed on 1216 some combinations of hardware and BIOS. The symptom, for which 1217 this config is intended, is when reboot ends with a stalled/hung 1218 system. 1219 1220 Currently, the only fixup is for the Geode machines using 1221 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1222 1223 Say Y if you want to enable the fixup. Currently, it's safe to 1224 enable this option even if you don't need it. 1225 Say N otherwise. 1226 1227config MICROCODE 1228 bool "CPU microcode loading support" 1229 default y 1230 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1231 select FW_LOADER 1232 ---help--- 1233 If you say Y here, you will be able to update the microcode on 1234 Intel and AMD processors. The Intel support is for the IA32 family, 1235 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1236 AMD support is for families 0x10 and later. You will obviously need 1237 the actual microcode binary data itself which is not shipped with 1238 the Linux kernel. 1239 1240 The preferred method to load microcode from a detached initrd is described 1241 in Documentation/x86/early-microcode.txt. For that you need to enable 1242 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1243 initrd for microcode blobs. 1244 1245 In addition, you can build-in the microcode into the kernel. For that you 1246 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1247 to the CONFIG_EXTRA_FIRMWARE config option. 1248 1249config MICROCODE_INTEL 1250 bool "Intel microcode loading support" 1251 depends on MICROCODE 1252 default MICROCODE 1253 select FW_LOADER 1254 ---help--- 1255 This options enables microcode patch loading support for Intel 1256 processors. 1257 1258 For the current Intel microcode data package go to 1259 <https://downloadcenter.intel.com> and search for 1260 'Linux Processor Microcode Data File'. 1261 1262config MICROCODE_AMD 1263 bool "AMD microcode loading support" 1264 depends on MICROCODE 1265 select FW_LOADER 1266 ---help--- 1267 If you select this option, microcode patch loading support for AMD 1268 processors will be enabled. 1269 1270config MICROCODE_OLD_INTERFACE 1271 def_bool y 1272 depends on MICROCODE 1273 1274config X86_MSR 1275 tristate "/dev/cpu/*/msr - Model-specific register support" 1276 ---help--- 1277 This device gives privileged processes access to the x86 1278 Model-Specific Registers (MSRs). It is a character device with 1279 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1280 MSR accesses are directed to a specific CPU on multi-processor 1281 systems. 1282 1283config X86_CPUID 1284 tristate "/dev/cpu/*/cpuid - CPU information support" 1285 ---help--- 1286 This device gives processes access to the x86 CPUID instruction to 1287 be executed on a specific processor. It is a character device 1288 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1289 /dev/cpu/31/cpuid. 1290 1291choice 1292 prompt "High Memory Support" 1293 default HIGHMEM4G 1294 depends on X86_32 1295 1296config NOHIGHMEM 1297 bool "off" 1298 ---help--- 1299 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1300 However, the address space of 32-bit x86 processors is only 4 1301 Gigabytes large. That means that, if you have a large amount of 1302 physical memory, not all of it can be "permanently mapped" by the 1303 kernel. The physical memory that's not permanently mapped is called 1304 "high memory". 1305 1306 If you are compiling a kernel which will never run on a machine with 1307 more than 1 Gigabyte total physical RAM, answer "off" here (default 1308 choice and suitable for most users). This will result in a "3GB/1GB" 1309 split: 3GB are mapped so that each process sees a 3GB virtual memory 1310 space and the remaining part of the 4GB virtual memory space is used 1311 by the kernel to permanently map as much physical memory as 1312 possible. 1313 1314 If the machine has between 1 and 4 Gigabytes physical RAM, then 1315 answer "4GB" here. 1316 1317 If more than 4 Gigabytes is used then answer "64GB" here. This 1318 selection turns Intel PAE (Physical Address Extension) mode on. 1319 PAE implements 3-level paging on IA32 processors. PAE is fully 1320 supported by Linux, PAE mode is implemented on all recent Intel 1321 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1322 then the kernel will not boot on CPUs that don't support PAE! 1323 1324 The actual amount of total physical memory will either be 1325 auto detected or can be forced by using a kernel command line option 1326 such as "mem=256M". (Try "man bootparam" or see the documentation of 1327 your boot loader (lilo or loadlin) about how to pass options to the 1328 kernel at boot time.) 1329 1330 If unsure, say "off". 1331 1332config HIGHMEM4G 1333 bool "4GB" 1334 ---help--- 1335 Select this if you have a 32-bit processor and between 1 and 4 1336 gigabytes of physical RAM. 1337 1338config HIGHMEM64G 1339 bool "64GB" 1340 depends on !M486 1341 select X86_PAE 1342 ---help--- 1343 Select this if you have a 32-bit processor and more than 4 1344 gigabytes of physical RAM. 1345 1346endchoice 1347 1348choice 1349 prompt "Memory split" if EXPERT 1350 default VMSPLIT_3G 1351 depends on X86_32 1352 ---help--- 1353 Select the desired split between kernel and user memory. 1354 1355 If the address range available to the kernel is less than the 1356 physical memory installed, the remaining memory will be available 1357 as "high memory". Accessing high memory is a little more costly 1358 than low memory, as it needs to be mapped into the kernel first. 1359 Note that increasing the kernel address space limits the range 1360 available to user programs, making the address space there 1361 tighter. Selecting anything other than the default 3G/1G split 1362 will also likely make your kernel incompatible with binary-only 1363 kernel modules. 1364 1365 If you are not absolutely sure what you are doing, leave this 1366 option alone! 1367 1368 config VMSPLIT_3G 1369 bool "3G/1G user/kernel split" 1370 config VMSPLIT_3G_OPT 1371 depends on !X86_PAE 1372 bool "3G/1G user/kernel split (for full 1G low memory)" 1373 config VMSPLIT_2G 1374 bool "2G/2G user/kernel split" 1375 config VMSPLIT_2G_OPT 1376 depends on !X86_PAE 1377 bool "2G/2G user/kernel split (for full 2G low memory)" 1378 config VMSPLIT_1G 1379 bool "1G/3G user/kernel split" 1380endchoice 1381 1382config PAGE_OFFSET 1383 hex 1384 default 0xB0000000 if VMSPLIT_3G_OPT 1385 default 0x80000000 if VMSPLIT_2G 1386 default 0x78000000 if VMSPLIT_2G_OPT 1387 default 0x40000000 if VMSPLIT_1G 1388 default 0xC0000000 1389 depends on X86_32 1390 1391config HIGHMEM 1392 def_bool y 1393 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1394 1395config X86_PAE 1396 bool "PAE (Physical Address Extension) Support" 1397 depends on X86_32 && !HIGHMEM4G 1398 select SWIOTLB 1399 ---help--- 1400 PAE is required for NX support, and furthermore enables 1401 larger swapspace support for non-overcommit purposes. It 1402 has the cost of more pagetable lookup overhead, and also 1403 consumes more pagetable space per process. 1404 1405config X86_5LEVEL 1406 bool "Enable 5-level page tables support" 1407 depends on X86_64 1408 ---help--- 1409 5-level paging enables access to larger address space: 1410 upto 128 PiB of virtual address space and 4 PiB of 1411 physical address space. 1412 1413 It will be supported by future Intel CPUs. 1414 1415 Note: a kernel with this option enabled can only be booted 1416 on machines that support the feature. 1417 1418 See Documentation/x86/x86_64/5level-paging.txt for more 1419 information. 1420 1421 Say N if unsure. 1422 1423config ARCH_PHYS_ADDR_T_64BIT 1424 def_bool y 1425 depends on X86_64 || X86_PAE 1426 1427config ARCH_DMA_ADDR_T_64BIT 1428 def_bool y 1429 depends on X86_64 || HIGHMEM64G 1430 1431config X86_DIRECT_GBPAGES 1432 def_bool y 1433 depends on X86_64 && !DEBUG_PAGEALLOC 1434 ---help--- 1435 Certain kernel features effectively disable kernel 1436 linear 1 GB mappings (even if the CPU otherwise 1437 supports them), so don't confuse the user by printing 1438 that we have them enabled. 1439 1440config ARCH_HAS_MEM_ENCRYPT 1441 def_bool y 1442 1443config AMD_MEM_ENCRYPT 1444 bool "AMD Secure Memory Encryption (SME) support" 1445 depends on X86_64 && CPU_SUP_AMD 1446 ---help--- 1447 Say yes to enable support for the encryption of system memory. 1448 This requires an AMD processor that supports Secure Memory 1449 Encryption (SME). 1450 1451config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1452 bool "Activate AMD Secure Memory Encryption (SME) by default" 1453 default y 1454 depends on AMD_MEM_ENCRYPT 1455 ---help--- 1456 Say yes to have system memory encrypted by default if running on 1457 an AMD processor that supports Secure Memory Encryption (SME). 1458 1459 If set to Y, then the encryption of system memory can be 1460 deactivated with the mem_encrypt=off command line option. 1461 1462 If set to N, then the encryption of system memory can be 1463 activated with the mem_encrypt=on command line option. 1464 1465config ARCH_USE_MEMREMAP_PROT 1466 def_bool y 1467 depends on AMD_MEM_ENCRYPT 1468 1469# Common NUMA Features 1470config NUMA 1471 bool "Numa Memory Allocation and Scheduler Support" 1472 depends on SMP 1473 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1474 default y if X86_BIGSMP 1475 ---help--- 1476 Enable NUMA (Non Uniform Memory Access) support. 1477 1478 The kernel will try to allocate memory used by a CPU on the 1479 local memory controller of the CPU and add some more 1480 NUMA awareness to the kernel. 1481 1482 For 64-bit this is recommended if the system is Intel Core i7 1483 (or later), AMD Opteron, or EM64T NUMA. 1484 1485 For 32-bit this is only needed if you boot a 32-bit 1486 kernel on a 64-bit NUMA platform. 1487 1488 Otherwise, you should say N. 1489 1490config AMD_NUMA 1491 def_bool y 1492 prompt "Old style AMD Opteron NUMA detection" 1493 depends on X86_64 && NUMA && PCI 1494 ---help--- 1495 Enable AMD NUMA node topology detection. You should say Y here if 1496 you have a multi processor AMD system. This uses an old method to 1497 read the NUMA configuration directly from the builtin Northbridge 1498 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1499 which also takes priority if both are compiled in. 1500 1501config X86_64_ACPI_NUMA 1502 def_bool y 1503 prompt "ACPI NUMA detection" 1504 depends on X86_64 && NUMA && ACPI && PCI 1505 select ACPI_NUMA 1506 ---help--- 1507 Enable ACPI SRAT based node topology detection. 1508 1509# Some NUMA nodes have memory ranges that span 1510# other nodes. Even though a pfn is valid and 1511# between a node's start and end pfns, it may not 1512# reside on that node. See memmap_init_zone() 1513# for details. 1514config NODES_SPAN_OTHER_NODES 1515 def_bool y 1516 depends on X86_64_ACPI_NUMA 1517 1518config NUMA_EMU 1519 bool "NUMA emulation" 1520 depends on NUMA 1521 ---help--- 1522 Enable NUMA emulation. A flat machine will be split 1523 into virtual nodes when booted with "numa=fake=N", where N is the 1524 number of nodes. This is only useful for debugging. 1525 1526config NODES_SHIFT 1527 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1528 range 1 10 1529 default "10" if MAXSMP 1530 default "6" if X86_64 1531 default "3" 1532 depends on NEED_MULTIPLE_NODES 1533 ---help--- 1534 Specify the maximum number of NUMA Nodes available on the target 1535 system. Increases memory reserved to accommodate various tables. 1536 1537config ARCH_HAVE_MEMORY_PRESENT 1538 def_bool y 1539 depends on X86_32 && DISCONTIGMEM 1540 1541config NEED_NODE_MEMMAP_SIZE 1542 def_bool y 1543 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1544 1545config ARCH_FLATMEM_ENABLE 1546 def_bool y 1547 depends on X86_32 && !NUMA 1548 1549config ARCH_DISCONTIGMEM_ENABLE 1550 def_bool y 1551 depends on NUMA && X86_32 1552 1553config ARCH_DISCONTIGMEM_DEFAULT 1554 def_bool y 1555 depends on NUMA && X86_32 1556 1557config ARCH_SPARSEMEM_ENABLE 1558 def_bool y 1559 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1560 select SPARSEMEM_STATIC if X86_32 1561 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1562 1563config ARCH_SPARSEMEM_DEFAULT 1564 def_bool y 1565 depends on X86_64 1566 1567config ARCH_SELECT_MEMORY_MODEL 1568 def_bool y 1569 depends on ARCH_SPARSEMEM_ENABLE 1570 1571config ARCH_MEMORY_PROBE 1572 bool "Enable sysfs memory/probe interface" 1573 depends on X86_64 && MEMORY_HOTPLUG 1574 help 1575 This option enables a sysfs memory/probe interface for testing. 1576 See Documentation/memory-hotplug.txt for more information. 1577 If you are unsure how to answer this question, answer N. 1578 1579config ARCH_PROC_KCORE_TEXT 1580 def_bool y 1581 depends on X86_64 && PROC_KCORE 1582 1583config ILLEGAL_POINTER_VALUE 1584 hex 1585 default 0 if X86_32 1586 default 0xdead000000000000 if X86_64 1587 1588source "mm/Kconfig" 1589 1590config X86_PMEM_LEGACY_DEVICE 1591 bool 1592 1593config X86_PMEM_LEGACY 1594 tristate "Support non-standard NVDIMMs and ADR protected memory" 1595 depends on PHYS_ADDR_T_64BIT 1596 depends on BLK_DEV 1597 select X86_PMEM_LEGACY_DEVICE 1598 select LIBNVDIMM 1599 help 1600 Treat memory marked using the non-standard e820 type of 12 as used 1601 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1602 The kernel will offer these regions to the 'pmem' driver so 1603 they can be used for persistent storage. 1604 1605 Say Y if unsure. 1606 1607config HIGHPTE 1608 bool "Allocate 3rd-level pagetables from highmem" 1609 depends on HIGHMEM 1610 ---help--- 1611 The VM uses one page table entry for each page of physical memory. 1612 For systems with a lot of RAM, this can be wasteful of precious 1613 low memory. Setting this option will put user-space page table 1614 entries in high memory. 1615 1616config X86_CHECK_BIOS_CORRUPTION 1617 bool "Check for low memory corruption" 1618 ---help--- 1619 Periodically check for memory corruption in low memory, which 1620 is suspected to be caused by BIOS. Even when enabled in the 1621 configuration, it is disabled at runtime. Enable it by 1622 setting "memory_corruption_check=1" on the kernel command 1623 line. By default it scans the low 64k of memory every 60 1624 seconds; see the memory_corruption_check_size and 1625 memory_corruption_check_period parameters in 1626 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1627 1628 When enabled with the default parameters, this option has 1629 almost no overhead, as it reserves a relatively small amount 1630 of memory and scans it infrequently. It both detects corruption 1631 and prevents it from affecting the running system. 1632 1633 It is, however, intended as a diagnostic tool; if repeatable 1634 BIOS-originated corruption always affects the same memory, 1635 you can use memmap= to prevent the kernel from using that 1636 memory. 1637 1638config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1639 bool "Set the default setting of memory_corruption_check" 1640 depends on X86_CHECK_BIOS_CORRUPTION 1641 default y 1642 ---help--- 1643 Set whether the default state of memory_corruption_check is 1644 on or off. 1645 1646config X86_RESERVE_LOW 1647 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1648 default 64 1649 range 4 640 1650 ---help--- 1651 Specify the amount of low memory to reserve for the BIOS. 1652 1653 The first page contains BIOS data structures that the kernel 1654 must not use, so that page must always be reserved. 1655 1656 By default we reserve the first 64K of physical RAM, as a 1657 number of BIOSes are known to corrupt that memory range 1658 during events such as suspend/resume or monitor cable 1659 insertion, so it must not be used by the kernel. 1660 1661 You can set this to 4 if you are absolutely sure that you 1662 trust the BIOS to get all its memory reservations and usages 1663 right. If you know your BIOS have problems beyond the 1664 default 64K area, you can set this to 640 to avoid using the 1665 entire low memory range. 1666 1667 If you have doubts about the BIOS (e.g. suspend/resume does 1668 not work or there's kernel crashes after certain hardware 1669 hotplug events) then you might want to enable 1670 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1671 typical corruption patterns. 1672 1673 Leave this to the default value of 64 if you are unsure. 1674 1675config MATH_EMULATION 1676 bool 1677 depends on MODIFY_LDT_SYSCALL 1678 prompt "Math emulation" if X86_32 1679 ---help--- 1680 Linux can emulate a math coprocessor (used for floating point 1681 operations) if you don't have one. 486DX and Pentium processors have 1682 a math coprocessor built in, 486SX and 386 do not, unless you added 1683 a 487DX or 387, respectively. (The messages during boot time can 1684 give you some hints here ["man dmesg"].) Everyone needs either a 1685 coprocessor or this emulation. 1686 1687 If you don't have a math coprocessor, you need to say Y here; if you 1688 say Y here even though you have a coprocessor, the coprocessor will 1689 be used nevertheless. (This behavior can be changed with the kernel 1690 command line option "no387", which comes handy if your coprocessor 1691 is broken. Try "man bootparam" or see the documentation of your boot 1692 loader (lilo or loadlin) about how to pass options to the kernel at 1693 boot time.) This means that it is a good idea to say Y here if you 1694 intend to use this kernel on different machines. 1695 1696 More information about the internals of the Linux math coprocessor 1697 emulation can be found in <file:arch/x86/math-emu/README>. 1698 1699 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1700 kernel, it won't hurt. 1701 1702config MTRR 1703 def_bool y 1704 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1705 ---help--- 1706 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1707 the Memory Type Range Registers (MTRRs) may be used to control 1708 processor access to memory ranges. This is most useful if you have 1709 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1710 allows bus write transfers to be combined into a larger transfer 1711 before bursting over the PCI/AGP bus. This can increase performance 1712 of image write operations 2.5 times or more. Saying Y here creates a 1713 /proc/mtrr file which may be used to manipulate your processor's 1714 MTRRs. Typically the X server should use this. 1715 1716 This code has a reasonably generic interface so that similar 1717 control registers on other processors can be easily supported 1718 as well: 1719 1720 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1721 Registers (ARRs) which provide a similar functionality to MTRRs. For 1722 these, the ARRs are used to emulate the MTRRs. 1723 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1724 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1725 write-combining. All of these processors are supported by this code 1726 and it makes sense to say Y here if you have one of them. 1727 1728 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1729 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1730 can lead to all sorts of problems, so it's good to say Y here. 1731 1732 You can safely say Y even if your machine doesn't have MTRRs, you'll 1733 just add about 9 KB to your kernel. 1734 1735 See <file:Documentation/x86/mtrr.txt> for more information. 1736 1737config MTRR_SANITIZER 1738 def_bool y 1739 prompt "MTRR cleanup support" 1740 depends on MTRR 1741 ---help--- 1742 Convert MTRR layout from continuous to discrete, so X drivers can 1743 add writeback entries. 1744 1745 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1746 The largest mtrr entry size for a continuous block can be set with 1747 mtrr_chunk_size. 1748 1749 If unsure, say Y. 1750 1751config MTRR_SANITIZER_ENABLE_DEFAULT 1752 int "MTRR cleanup enable value (0-1)" 1753 range 0 1 1754 default "0" 1755 depends on MTRR_SANITIZER 1756 ---help--- 1757 Enable mtrr cleanup default value 1758 1759config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1760 int "MTRR cleanup spare reg num (0-7)" 1761 range 0 7 1762 default "1" 1763 depends on MTRR_SANITIZER 1764 ---help--- 1765 mtrr cleanup spare entries default, it can be changed via 1766 mtrr_spare_reg_nr=N on the kernel command line. 1767 1768config X86_PAT 1769 def_bool y 1770 prompt "x86 PAT support" if EXPERT 1771 depends on MTRR 1772 ---help--- 1773 Use PAT attributes to setup page level cache control. 1774 1775 PATs are the modern equivalents of MTRRs and are much more 1776 flexible than MTRRs. 1777 1778 Say N here if you see bootup problems (boot crash, boot hang, 1779 spontaneous reboots) or a non-working video driver. 1780 1781 If unsure, say Y. 1782 1783config ARCH_USES_PG_UNCACHED 1784 def_bool y 1785 depends on X86_PAT 1786 1787config ARCH_RANDOM 1788 def_bool y 1789 prompt "x86 architectural random number generator" if EXPERT 1790 ---help--- 1791 Enable the x86 architectural RDRAND instruction 1792 (Intel Bull Mountain technology) to generate random numbers. 1793 If supported, this is a high bandwidth, cryptographically 1794 secure hardware random number generator. 1795 1796config X86_SMAP 1797 def_bool y 1798 prompt "Supervisor Mode Access Prevention" if EXPERT 1799 ---help--- 1800 Supervisor Mode Access Prevention (SMAP) is a security 1801 feature in newer Intel processors. There is a small 1802 performance cost if this enabled and turned on; there is 1803 also a small increase in the kernel size if this is enabled. 1804 1805 If unsure, say Y. 1806 1807config X86_INTEL_UMIP 1808 def_bool y 1809 depends on CPU_SUP_INTEL 1810 prompt "Intel User Mode Instruction Prevention" if EXPERT 1811 ---help--- 1812 The User Mode Instruction Prevention (UMIP) is a security 1813 feature in newer Intel processors. If enabled, a general 1814 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1815 or STR instructions are executed in user mode. These instructions 1816 unnecessarily expose information about the hardware state. 1817 1818 The vast majority of applications do not use these instructions. 1819 For the very few that do, software emulation is provided in 1820 specific cases in protected and virtual-8086 modes. Emulated 1821 results are dummy. 1822 1823config X86_INTEL_MPX 1824 prompt "Intel MPX (Memory Protection Extensions)" 1825 def_bool n 1826 # Note: only available in 64-bit mode due to VMA flags shortage 1827 depends on CPU_SUP_INTEL && X86_64 1828 select ARCH_USES_HIGH_VMA_FLAGS 1829 ---help--- 1830 MPX provides hardware features that can be used in 1831 conjunction with compiler-instrumented code to check 1832 memory references. It is designed to detect buffer 1833 overflow or underflow bugs. 1834 1835 This option enables running applications which are 1836 instrumented or otherwise use MPX. It does not use MPX 1837 itself inside the kernel or to protect the kernel 1838 against bad memory references. 1839 1840 Enabling this option will make the kernel larger: 1841 ~8k of kernel text and 36 bytes of data on a 64-bit 1842 defconfig. It adds a long to the 'mm_struct' which 1843 will increase the kernel memory overhead of each 1844 process and adds some branches to paths used during 1845 exec() and munmap(). 1846 1847 For details, see Documentation/x86/intel_mpx.txt 1848 1849 If unsure, say N. 1850 1851config X86_INTEL_MEMORY_PROTECTION_KEYS 1852 prompt "Intel Memory Protection Keys" 1853 def_bool y 1854 # Note: only available in 64-bit mode 1855 depends on CPU_SUP_INTEL && X86_64 1856 select ARCH_USES_HIGH_VMA_FLAGS 1857 select ARCH_HAS_PKEYS 1858 ---help--- 1859 Memory Protection Keys provides a mechanism for enforcing 1860 page-based protections, but without requiring modification of the 1861 page tables when an application changes protection domains. 1862 1863 For details, see Documentation/x86/protection-keys.txt 1864 1865 If unsure, say y. 1866 1867config EFI 1868 bool "EFI runtime service support" 1869 depends on ACPI 1870 select UCS2_STRING 1871 select EFI_RUNTIME_WRAPPERS 1872 ---help--- 1873 This enables the kernel to use EFI runtime services that are 1874 available (such as the EFI variable services). 1875 1876 This option is only useful on systems that have EFI firmware. 1877 In addition, you should use the latest ELILO loader available 1878 at <http://elilo.sourceforge.net> in order to take advantage 1879 of EFI runtime services. However, even with this option, the 1880 resultant kernel should continue to boot on existing non-EFI 1881 platforms. 1882 1883config EFI_STUB 1884 bool "EFI stub support" 1885 depends on EFI && !X86_USE_3DNOW 1886 select RELOCATABLE 1887 ---help--- 1888 This kernel feature allows a bzImage to be loaded directly 1889 by EFI firmware without the use of a bootloader. 1890 1891 See Documentation/efi-stub.txt for more information. 1892 1893config EFI_MIXED 1894 bool "EFI mixed-mode support" 1895 depends on EFI_STUB && X86_64 1896 ---help--- 1897 Enabling this feature allows a 64-bit kernel to be booted 1898 on a 32-bit firmware, provided that your CPU supports 64-bit 1899 mode. 1900 1901 Note that it is not possible to boot a mixed-mode enabled 1902 kernel via the EFI boot stub - a bootloader that supports 1903 the EFI handover protocol must be used. 1904 1905 If unsure, say N. 1906 1907config SECCOMP 1908 def_bool y 1909 prompt "Enable seccomp to safely compute untrusted bytecode" 1910 ---help--- 1911 This kernel feature is useful for number crunching applications 1912 that may need to compute untrusted bytecode during their 1913 execution. By using pipes or other transports made available to 1914 the process as file descriptors supporting the read/write 1915 syscalls, it's possible to isolate those applications in 1916 their own address space using seccomp. Once seccomp is 1917 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1918 and the task is only allowed to execute a few safe syscalls 1919 defined by each seccomp mode. 1920 1921 If unsure, say Y. Only embedded should say N here. 1922 1923source kernel/Kconfig.hz 1924 1925config KEXEC 1926 bool "kexec system call" 1927 select KEXEC_CORE 1928 ---help--- 1929 kexec is a system call that implements the ability to shutdown your 1930 current kernel, and to start another kernel. It is like a reboot 1931 but it is independent of the system firmware. And like a reboot 1932 you can start any kernel with it, not just Linux. 1933 1934 The name comes from the similarity to the exec system call. 1935 1936 It is an ongoing process to be certain the hardware in a machine 1937 is properly shutdown, so do not be surprised if this code does not 1938 initially work for you. As of this writing the exact hardware 1939 interface is strongly in flux, so no good recommendation can be 1940 made. 1941 1942config KEXEC_FILE 1943 bool "kexec file based system call" 1944 select KEXEC_CORE 1945 select BUILD_BIN2C 1946 depends on X86_64 1947 depends on CRYPTO=y 1948 depends on CRYPTO_SHA256=y 1949 ---help--- 1950 This is new version of kexec system call. This system call is 1951 file based and takes file descriptors as system call argument 1952 for kernel and initramfs as opposed to list of segments as 1953 accepted by previous system call. 1954 1955config KEXEC_VERIFY_SIG 1956 bool "Verify kernel signature during kexec_file_load() syscall" 1957 depends on KEXEC_FILE 1958 ---help--- 1959 This option makes kernel signature verification mandatory for 1960 the kexec_file_load() syscall. 1961 1962 In addition to that option, you need to enable signature 1963 verification for the corresponding kernel image type being 1964 loaded in order for this to work. 1965 1966config KEXEC_BZIMAGE_VERIFY_SIG 1967 bool "Enable bzImage signature verification support" 1968 depends on KEXEC_VERIFY_SIG 1969 depends on SIGNED_PE_FILE_VERIFICATION 1970 select SYSTEM_TRUSTED_KEYRING 1971 ---help--- 1972 Enable bzImage signature verification support. 1973 1974config CRASH_DUMP 1975 bool "kernel crash dumps" 1976 depends on X86_64 || (X86_32 && HIGHMEM) 1977 ---help--- 1978 Generate crash dump after being started by kexec. 1979 This should be normally only set in special crash dump kernels 1980 which are loaded in the main kernel with kexec-tools into 1981 a specially reserved region and then later executed after 1982 a crash by kdump/kexec. The crash dump kernel must be compiled 1983 to a memory address not used by the main kernel or BIOS using 1984 PHYSICAL_START, or it must be built as a relocatable image 1985 (CONFIG_RELOCATABLE=y). 1986 For more details see Documentation/kdump/kdump.txt 1987 1988config KEXEC_JUMP 1989 bool "kexec jump" 1990 depends on KEXEC && HIBERNATION 1991 ---help--- 1992 Jump between original kernel and kexeced kernel and invoke 1993 code in physical address mode via KEXEC 1994 1995config PHYSICAL_START 1996 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1997 default "0x1000000" 1998 ---help--- 1999 This gives the physical address where the kernel is loaded. 2000 2001 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2002 bzImage will decompress itself to above physical address and 2003 run from there. Otherwise, bzImage will run from the address where 2004 it has been loaded by the boot loader and will ignore above physical 2005 address. 2006 2007 In normal kdump cases one does not have to set/change this option 2008 as now bzImage can be compiled as a completely relocatable image 2009 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2010 address. This option is mainly useful for the folks who don't want 2011 to use a bzImage for capturing the crash dump and want to use a 2012 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2013 to be specifically compiled to run from a specific memory area 2014 (normally a reserved region) and this option comes handy. 2015 2016 So if you are using bzImage for capturing the crash dump, 2017 leave the value here unchanged to 0x1000000 and set 2018 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2019 for capturing the crash dump change this value to start of 2020 the reserved region. In other words, it can be set based on 2021 the "X" value as specified in the "crashkernel=YM@XM" 2022 command line boot parameter passed to the panic-ed 2023 kernel. Please take a look at Documentation/kdump/kdump.txt 2024 for more details about crash dumps. 2025 2026 Usage of bzImage for capturing the crash dump is recommended as 2027 one does not have to build two kernels. Same kernel can be used 2028 as production kernel and capture kernel. Above option should have 2029 gone away after relocatable bzImage support is introduced. But it 2030 is present because there are users out there who continue to use 2031 vmlinux for dump capture. This option should go away down the 2032 line. 2033 2034 Don't change this unless you know what you are doing. 2035 2036config RELOCATABLE 2037 bool "Build a relocatable kernel" 2038 default y 2039 ---help--- 2040 This builds a kernel image that retains relocation information 2041 so it can be loaded someplace besides the default 1MB. 2042 The relocations tend to make the kernel binary about 10% larger, 2043 but are discarded at runtime. 2044 2045 One use is for the kexec on panic case where the recovery kernel 2046 must live at a different physical address than the primary 2047 kernel. 2048 2049 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2050 it has been loaded at and the compile time physical address 2051 (CONFIG_PHYSICAL_START) is used as the minimum location. 2052 2053config RANDOMIZE_BASE 2054 bool "Randomize the address of the kernel image (KASLR)" 2055 depends on RELOCATABLE 2056 default y 2057 ---help--- 2058 In support of Kernel Address Space Layout Randomization (KASLR), 2059 this randomizes the physical address at which the kernel image 2060 is decompressed and the virtual address where the kernel 2061 image is mapped, as a security feature that deters exploit 2062 attempts relying on knowledge of the location of kernel 2063 code internals. 2064 2065 On 64-bit, the kernel physical and virtual addresses are 2066 randomized separately. The physical address will be anywhere 2067 between 16MB and the top of physical memory (up to 64TB). The 2068 virtual address will be randomized from 16MB up to 1GB (9 bits 2069 of entropy). Note that this also reduces the memory space 2070 available to kernel modules from 1.5GB to 1GB. 2071 2072 On 32-bit, the kernel physical and virtual addresses are 2073 randomized together. They will be randomized from 16MB up to 2074 512MB (8 bits of entropy). 2075 2076 Entropy is generated using the RDRAND instruction if it is 2077 supported. If RDTSC is supported, its value is mixed into 2078 the entropy pool as well. If neither RDRAND nor RDTSC are 2079 supported, then entropy is read from the i8254 timer. The 2080 usable entropy is limited by the kernel being built using 2081 2GB addressing, and that PHYSICAL_ALIGN must be at a 2082 minimum of 2MB. As a result, only 10 bits of entropy are 2083 theoretically possible, but the implementations are further 2084 limited due to memory layouts. 2085 2086 If unsure, say Y. 2087 2088# Relocation on x86 needs some additional build support 2089config X86_NEED_RELOCS 2090 def_bool y 2091 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2092 2093config PHYSICAL_ALIGN 2094 hex "Alignment value to which kernel should be aligned" 2095 default "0x200000" 2096 range 0x2000 0x1000000 if X86_32 2097 range 0x200000 0x1000000 if X86_64 2098 ---help--- 2099 This value puts the alignment restrictions on physical address 2100 where kernel is loaded and run from. Kernel is compiled for an 2101 address which meets above alignment restriction. 2102 2103 If bootloader loads the kernel at a non-aligned address and 2104 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2105 address aligned to above value and run from there. 2106 2107 If bootloader loads the kernel at a non-aligned address and 2108 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2109 load address and decompress itself to the address it has been 2110 compiled for and run from there. The address for which kernel is 2111 compiled already meets above alignment restrictions. Hence the 2112 end result is that kernel runs from a physical address meeting 2113 above alignment restrictions. 2114 2115 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2116 this value must be a multiple of 0x200000. 2117 2118 Don't change this unless you know what you are doing. 2119 2120config RANDOMIZE_MEMORY 2121 bool "Randomize the kernel memory sections" 2122 depends on X86_64 2123 depends on RANDOMIZE_BASE 2124 default RANDOMIZE_BASE 2125 ---help--- 2126 Randomizes the base virtual address of kernel memory sections 2127 (physical memory mapping, vmalloc & vmemmap). This security feature 2128 makes exploits relying on predictable memory locations less reliable. 2129 2130 The order of allocations remains unchanged. Entropy is generated in 2131 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2132 configuration have in average 30,000 different possible virtual 2133 addresses for each memory section. 2134 2135 If unsure, say Y. 2136 2137config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2138 hex "Physical memory mapping padding" if EXPERT 2139 depends on RANDOMIZE_MEMORY 2140 default "0xa" if MEMORY_HOTPLUG 2141 default "0x0" 2142 range 0x1 0x40 if MEMORY_HOTPLUG 2143 range 0x0 0x40 2144 ---help--- 2145 Define the padding in terabytes added to the existing physical 2146 memory size during kernel memory randomization. It is useful 2147 for memory hotplug support but reduces the entropy available for 2148 address randomization. 2149 2150 If unsure, leave at the default value. 2151 2152config HOTPLUG_CPU 2153 bool "Support for hot-pluggable CPUs" 2154 depends on SMP 2155 ---help--- 2156 Say Y here to allow turning CPUs off and on. CPUs can be 2157 controlled through /sys/devices/system/cpu. 2158 ( Note: power management support will enable this option 2159 automatically on SMP systems. ) 2160 Say N if you want to disable CPU hotplug. 2161 2162config BOOTPARAM_HOTPLUG_CPU0 2163 bool "Set default setting of cpu0_hotpluggable" 2164 default n 2165 depends on HOTPLUG_CPU 2166 ---help--- 2167 Set whether default state of cpu0_hotpluggable is on or off. 2168 2169 Say Y here to enable CPU0 hotplug by default. If this switch 2170 is turned on, there is no need to give cpu0_hotplug kernel 2171 parameter and the CPU0 hotplug feature is enabled by default. 2172 2173 Please note: there are two known CPU0 dependencies if you want 2174 to enable the CPU0 hotplug feature either by this switch or by 2175 cpu0_hotplug kernel parameter. 2176 2177 First, resume from hibernate or suspend always starts from CPU0. 2178 So hibernate and suspend are prevented if CPU0 is offline. 2179 2180 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2181 offline if any interrupt can not migrate out of CPU0. There may 2182 be other CPU0 dependencies. 2183 2184 Please make sure the dependencies are under your control before 2185 you enable this feature. 2186 2187 Say N if you don't want to enable CPU0 hotplug feature by default. 2188 You still can enable the CPU0 hotplug feature at boot by kernel 2189 parameter cpu0_hotplug. 2190 2191config DEBUG_HOTPLUG_CPU0 2192 def_bool n 2193 prompt "Debug CPU0 hotplug" 2194 depends on HOTPLUG_CPU 2195 ---help--- 2196 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2197 soon as possible and boots up userspace with CPU0 offlined. User 2198 can online CPU0 back after boot time. 2199 2200 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2201 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2202 compilation or giving cpu0_hotplug kernel parameter at boot. 2203 2204 If unsure, say N. 2205 2206config COMPAT_VDSO 2207 def_bool n 2208 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2209 depends on COMPAT_32 2210 ---help--- 2211 Certain buggy versions of glibc will crash if they are 2212 presented with a 32-bit vDSO that is not mapped at the address 2213 indicated in its segment table. 2214 2215 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2216 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2217 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2218 the only released version with the bug, but OpenSUSE 9 2219 contains a buggy "glibc 2.3.2". 2220 2221 The symptom of the bug is that everything crashes on startup, saying: 2222 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2223 2224 Saying Y here changes the default value of the vdso32 boot 2225 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2226 This works around the glibc bug but hurts performance. 2227 2228 If unsure, say N: if you are compiling your own kernel, you 2229 are unlikely to be using a buggy version of glibc. 2230 2231choice 2232 prompt "vsyscall table for legacy applications" 2233 depends on X86_64 2234 default LEGACY_VSYSCALL_EMULATE 2235 help 2236 Legacy user code that does not know how to find the vDSO expects 2237 to be able to issue three syscalls by calling fixed addresses in 2238 kernel space. Since this location is not randomized with ASLR, 2239 it can be used to assist security vulnerability exploitation. 2240 2241 This setting can be changed at boot time via the kernel command 2242 line parameter vsyscall=[native|emulate|none]. 2243 2244 On a system with recent enough glibc (2.14 or newer) and no 2245 static binaries, you can say None without a performance penalty 2246 to improve security. 2247 2248 If unsure, select "Emulate". 2249 2250 config LEGACY_VSYSCALL_NATIVE 2251 bool "Native" 2252 help 2253 Actual executable code is located in the fixed vsyscall 2254 address mapping, implementing time() efficiently. Since 2255 this makes the mapping executable, it can be used during 2256 security vulnerability exploitation (traditionally as 2257 ROP gadgets). This configuration is not recommended. 2258 2259 config LEGACY_VSYSCALL_EMULATE 2260 bool "Emulate" 2261 help 2262 The kernel traps and emulates calls into the fixed 2263 vsyscall address mapping. This makes the mapping 2264 non-executable, but it still contains known contents, 2265 which could be used in certain rare security vulnerability 2266 exploits. This configuration is recommended when userspace 2267 still uses the vsyscall area. 2268 2269 config LEGACY_VSYSCALL_NONE 2270 bool "None" 2271 help 2272 There will be no vsyscall mapping at all. This will 2273 eliminate any risk of ASLR bypass due to the vsyscall 2274 fixed address mapping. Attempts to use the vsyscalls 2275 will be reported to dmesg, so that either old or 2276 malicious userspace programs can be identified. 2277 2278endchoice 2279 2280config CMDLINE_BOOL 2281 bool "Built-in kernel command line" 2282 ---help--- 2283 Allow for specifying boot arguments to the kernel at 2284 build time. On some systems (e.g. embedded ones), it is 2285 necessary or convenient to provide some or all of the 2286 kernel boot arguments with the kernel itself (that is, 2287 to not rely on the boot loader to provide them.) 2288 2289 To compile command line arguments into the kernel, 2290 set this option to 'Y', then fill in the 2291 boot arguments in CONFIG_CMDLINE. 2292 2293 Systems with fully functional boot loaders (i.e. non-embedded) 2294 should leave this option set to 'N'. 2295 2296config CMDLINE 2297 string "Built-in kernel command string" 2298 depends on CMDLINE_BOOL 2299 default "" 2300 ---help--- 2301 Enter arguments here that should be compiled into the kernel 2302 image and used at boot time. If the boot loader provides a 2303 command line at boot time, it is appended to this string to 2304 form the full kernel command line, when the system boots. 2305 2306 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2307 change this behavior. 2308 2309 In most cases, the command line (whether built-in or provided 2310 by the boot loader) should specify the device for the root 2311 file system. 2312 2313config CMDLINE_OVERRIDE 2314 bool "Built-in command line overrides boot loader arguments" 2315 depends on CMDLINE_BOOL 2316 ---help--- 2317 Set this option to 'Y' to have the kernel ignore the boot loader 2318 command line, and use ONLY the built-in command line. 2319 2320 This is used to work around broken boot loaders. This should 2321 be set to 'N' under normal conditions. 2322 2323config MODIFY_LDT_SYSCALL 2324 bool "Enable the LDT (local descriptor table)" if EXPERT 2325 default y 2326 ---help--- 2327 Linux can allow user programs to install a per-process x86 2328 Local Descriptor Table (LDT) using the modify_ldt(2) system 2329 call. This is required to run 16-bit or segmented code such as 2330 DOSEMU or some Wine programs. It is also used by some very old 2331 threading libraries. 2332 2333 Enabling this feature adds a small amount of overhead to 2334 context switches and increases the low-level kernel attack 2335 surface. Disabling it removes the modify_ldt(2) system call. 2336 2337 Saying 'N' here may make sense for embedded or server kernels. 2338 2339source "kernel/livepatch/Kconfig" 2340 2341endmenu 2342 2343config ARCH_HAS_ADD_PAGES 2344 def_bool y 2345 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2346 2347config ARCH_ENABLE_MEMORY_HOTPLUG 2348 def_bool y 2349 depends on X86_64 || (X86_32 && HIGHMEM) 2350 2351config ARCH_ENABLE_MEMORY_HOTREMOVE 2352 def_bool y 2353 depends on MEMORY_HOTPLUG 2354 2355config USE_PERCPU_NUMA_NODE_ID 2356 def_bool y 2357 depends on NUMA 2358 2359config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2360 def_bool y 2361 depends on X86_64 || X86_PAE 2362 2363config ARCH_ENABLE_HUGEPAGE_MIGRATION 2364 def_bool y 2365 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2366 2367config ARCH_ENABLE_THP_MIGRATION 2368 def_bool y 2369 depends on X86_64 && TRANSPARENT_HUGEPAGE 2370 2371menu "Power management and ACPI options" 2372 2373config ARCH_HIBERNATION_HEADER 2374 def_bool y 2375 depends on X86_64 && HIBERNATION 2376 2377source "kernel/power/Kconfig" 2378 2379source "drivers/acpi/Kconfig" 2380 2381source "drivers/sfi/Kconfig" 2382 2383config X86_APM_BOOT 2384 def_bool y 2385 depends on APM 2386 2387menuconfig APM 2388 tristate "APM (Advanced Power Management) BIOS support" 2389 depends on X86_32 && PM_SLEEP 2390 ---help--- 2391 APM is a BIOS specification for saving power using several different 2392 techniques. This is mostly useful for battery powered laptops with 2393 APM compliant BIOSes. If you say Y here, the system time will be 2394 reset after a RESUME operation, the /proc/apm device will provide 2395 battery status information, and user-space programs will receive 2396 notification of APM "events" (e.g. battery status change). 2397 2398 If you select "Y" here, you can disable actual use of the APM 2399 BIOS by passing the "apm=off" option to the kernel at boot time. 2400 2401 Note that the APM support is almost completely disabled for 2402 machines with more than one CPU. 2403 2404 In order to use APM, you will need supporting software. For location 2405 and more information, read <file:Documentation/power/apm-acpi.txt> 2406 and the Battery Powered Linux mini-HOWTO, available from 2407 <http://www.tldp.org/docs.html#howto>. 2408 2409 This driver does not spin down disk drives (see the hdparm(8) 2410 manpage ("man 8 hdparm") for that), and it doesn't turn off 2411 VESA-compliant "green" monitors. 2412 2413 This driver does not support the TI 4000M TravelMate and the ACER 2414 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2415 desktop machines also don't have compliant BIOSes, and this driver 2416 may cause those machines to panic during the boot phase. 2417 2418 Generally, if you don't have a battery in your machine, there isn't 2419 much point in using this driver and you should say N. If you get 2420 random kernel OOPSes or reboots that don't seem to be related to 2421 anything, try disabling/enabling this option (or disabling/enabling 2422 APM in your BIOS). 2423 2424 Some other things you should try when experiencing seemingly random, 2425 "weird" problems: 2426 2427 1) make sure that you have enough swap space and that it is 2428 enabled. 2429 2) pass the "no-hlt" option to the kernel 2430 3) switch on floating point emulation in the kernel and pass 2431 the "no387" option to the kernel 2432 4) pass the "floppy=nodma" option to the kernel 2433 5) pass the "mem=4M" option to the kernel (thereby disabling 2434 all but the first 4 MB of RAM) 2435 6) make sure that the CPU is not over clocked. 2436 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2437 8) disable the cache from your BIOS settings 2438 9) install a fan for the video card or exchange video RAM 2439 10) install a better fan for the CPU 2440 11) exchange RAM chips 2441 12) exchange the motherboard. 2442 2443 To compile this driver as a module, choose M here: the 2444 module will be called apm. 2445 2446if APM 2447 2448config APM_IGNORE_USER_SUSPEND 2449 bool "Ignore USER SUSPEND" 2450 ---help--- 2451 This option will ignore USER SUSPEND requests. On machines with a 2452 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2453 series notebooks, it is necessary to say Y because of a BIOS bug. 2454 2455config APM_DO_ENABLE 2456 bool "Enable PM at boot time" 2457 ---help--- 2458 Enable APM features at boot time. From page 36 of the APM BIOS 2459 specification: "When disabled, the APM BIOS does not automatically 2460 power manage devices, enter the Standby State, enter the Suspend 2461 State, or take power saving steps in response to CPU Idle calls." 2462 This driver will make CPU Idle calls when Linux is idle (unless this 2463 feature is turned off -- see "Do CPU IDLE calls", below). This 2464 should always save battery power, but more complicated APM features 2465 will be dependent on your BIOS implementation. You may need to turn 2466 this option off if your computer hangs at boot time when using APM 2467 support, or if it beeps continuously instead of suspending. Turn 2468 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2469 T400CDT. This is off by default since most machines do fine without 2470 this feature. 2471 2472config APM_CPU_IDLE 2473 depends on CPU_IDLE 2474 bool "Make CPU Idle calls when idle" 2475 ---help--- 2476 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2477 On some machines, this can activate improved power savings, such as 2478 a slowed CPU clock rate, when the machine is idle. These idle calls 2479 are made after the idle loop has run for some length of time (e.g., 2480 333 mS). On some machines, this will cause a hang at boot time or 2481 whenever the CPU becomes idle. (On machines with more than one CPU, 2482 this option does nothing.) 2483 2484config APM_DISPLAY_BLANK 2485 bool "Enable console blanking using APM" 2486 ---help--- 2487 Enable console blanking using the APM. Some laptops can use this to 2488 turn off the LCD backlight when the screen blanker of the Linux 2489 virtual console blanks the screen. Note that this is only used by 2490 the virtual console screen blanker, and won't turn off the backlight 2491 when using the X Window system. This also doesn't have anything to 2492 do with your VESA-compliant power-saving monitor. Further, this 2493 option doesn't work for all laptops -- it might not turn off your 2494 backlight at all, or it might print a lot of errors to the console, 2495 especially if you are using gpm. 2496 2497config APM_ALLOW_INTS 2498 bool "Allow interrupts during APM BIOS calls" 2499 ---help--- 2500 Normally we disable external interrupts while we are making calls to 2501 the APM BIOS as a measure to lessen the effects of a badly behaving 2502 BIOS implementation. The BIOS should reenable interrupts if it 2503 needs to. Unfortunately, some BIOSes do not -- especially those in 2504 many of the newer IBM Thinkpads. If you experience hangs when you 2505 suspend, try setting this to Y. Otherwise, say N. 2506 2507endif # APM 2508 2509source "drivers/cpufreq/Kconfig" 2510 2511source "drivers/cpuidle/Kconfig" 2512 2513source "drivers/idle/Kconfig" 2514 2515endmenu 2516 2517 2518menu "Bus options (PCI etc.)" 2519 2520config PCI 2521 bool "PCI support" 2522 default y 2523 ---help--- 2524 Find out whether you have a PCI motherboard. PCI is the name of a 2525 bus system, i.e. the way the CPU talks to the other stuff inside 2526 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2527 VESA. If you have PCI, say Y, otherwise N. 2528 2529choice 2530 prompt "PCI access mode" 2531 depends on X86_32 && PCI 2532 default PCI_GOANY 2533 ---help--- 2534 On PCI systems, the BIOS can be used to detect the PCI devices and 2535 determine their configuration. However, some old PCI motherboards 2536 have BIOS bugs and may crash if this is done. Also, some embedded 2537 PCI-based systems don't have any BIOS at all. Linux can also try to 2538 detect the PCI hardware directly without using the BIOS. 2539 2540 With this option, you can specify how Linux should detect the 2541 PCI devices. If you choose "BIOS", the BIOS will be used, 2542 if you choose "Direct", the BIOS won't be used, and if you 2543 choose "MMConfig", then PCI Express MMCONFIG will be used. 2544 If you choose "Any", the kernel will try MMCONFIG, then the 2545 direct access method and falls back to the BIOS if that doesn't 2546 work. If unsure, go with the default, which is "Any". 2547 2548config PCI_GOBIOS 2549 bool "BIOS" 2550 2551config PCI_GOMMCONFIG 2552 bool "MMConfig" 2553 2554config PCI_GODIRECT 2555 bool "Direct" 2556 2557config PCI_GOOLPC 2558 bool "OLPC XO-1" 2559 depends on OLPC 2560 2561config PCI_GOANY 2562 bool "Any" 2563 2564endchoice 2565 2566config PCI_BIOS 2567 def_bool y 2568 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2569 2570# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2571config PCI_DIRECT 2572 def_bool y 2573 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2574 2575config PCI_MMCONFIG 2576 def_bool y 2577 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2578 2579config PCI_OLPC 2580 def_bool y 2581 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2582 2583config PCI_XEN 2584 def_bool y 2585 depends on PCI && XEN 2586 select SWIOTLB_XEN 2587 2588config PCI_DOMAINS 2589 def_bool y 2590 depends on PCI 2591 2592config PCI_MMCONFIG 2593 bool "Support mmconfig PCI config space access" 2594 depends on X86_64 && PCI && ACPI 2595 2596config PCI_CNB20LE_QUIRK 2597 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2598 depends on PCI 2599 help 2600 Read the PCI windows out of the CNB20LE host bridge. This allows 2601 PCI hotplug to work on systems with the CNB20LE chipset which do 2602 not have ACPI. 2603 2604 There's no public spec for this chipset, and this functionality 2605 is known to be incomplete. 2606 2607 You should say N unless you know you need this. 2608 2609source "drivers/pci/Kconfig" 2610 2611config ISA_BUS 2612 bool "ISA-style bus support on modern systems" if EXPERT 2613 select ISA_BUS_API 2614 help 2615 Enables ISA-style drivers on modern systems. This is necessary to 2616 support PC/104 devices on X86_64 platforms. 2617 2618 If unsure, say N. 2619 2620# x86_64 have no ISA slots, but can have ISA-style DMA. 2621config ISA_DMA_API 2622 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2623 default y 2624 help 2625 Enables ISA-style DMA support for devices requiring such controllers. 2626 If unsure, say Y. 2627 2628if X86_32 2629 2630config ISA 2631 bool "ISA support" 2632 ---help--- 2633 Find out whether you have ISA slots on your motherboard. ISA is the 2634 name of a bus system, i.e. the way the CPU talks to the other stuff 2635 inside your box. Other bus systems are PCI, EISA, MicroChannel 2636 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2637 newer boards don't support it. If you have ISA, say Y, otherwise N. 2638 2639config EISA 2640 bool "EISA support" 2641 depends on ISA 2642 ---help--- 2643 The Extended Industry Standard Architecture (EISA) bus was 2644 developed as an open alternative to the IBM MicroChannel bus. 2645 2646 The EISA bus provided some of the features of the IBM MicroChannel 2647 bus while maintaining backward compatibility with cards made for 2648 the older ISA bus. The EISA bus saw limited use between 1988 and 2649 1995 when it was made obsolete by the PCI bus. 2650 2651 Say Y here if you are building a kernel for an EISA-based machine. 2652 2653 Otherwise, say N. 2654 2655source "drivers/eisa/Kconfig" 2656 2657config SCx200 2658 tristate "NatSemi SCx200 support" 2659 ---help--- 2660 This provides basic support for National Semiconductor's 2661 (now AMD's) Geode processors. The driver probes for the 2662 PCI-IDs of several on-chip devices, so its a good dependency 2663 for other scx200_* drivers. 2664 2665 If compiled as a module, the driver is named scx200. 2666 2667config SCx200HR_TIMER 2668 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2669 depends on SCx200 2670 default y 2671 ---help--- 2672 This driver provides a clocksource built upon the on-chip 2673 27MHz high-resolution timer. Its also a workaround for 2674 NSC Geode SC-1100's buggy TSC, which loses time when the 2675 processor goes idle (as is done by the scheduler). The 2676 other workaround is idle=poll boot option. 2677 2678config OLPC 2679 bool "One Laptop Per Child support" 2680 depends on !X86_PAE 2681 select GPIOLIB 2682 select OF 2683 select OF_PROMTREE 2684 select IRQ_DOMAIN 2685 ---help--- 2686 Add support for detecting the unique features of the OLPC 2687 XO hardware. 2688 2689config OLPC_XO1_PM 2690 bool "OLPC XO-1 Power Management" 2691 depends on OLPC && MFD_CS5535 && PM_SLEEP 2692 select MFD_CORE 2693 ---help--- 2694 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2695 2696config OLPC_XO1_RTC 2697 bool "OLPC XO-1 Real Time Clock" 2698 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2699 ---help--- 2700 Add support for the XO-1 real time clock, which can be used as a 2701 programmable wakeup source. 2702 2703config OLPC_XO1_SCI 2704 bool "OLPC XO-1 SCI extras" 2705 depends on OLPC && OLPC_XO1_PM 2706 depends on INPUT=y 2707 select POWER_SUPPLY 2708 select GPIO_CS5535 2709 select MFD_CORE 2710 ---help--- 2711 Add support for SCI-based features of the OLPC XO-1 laptop: 2712 - EC-driven system wakeups 2713 - Power button 2714 - Ebook switch 2715 - Lid switch 2716 - AC adapter status updates 2717 - Battery status updates 2718 2719config OLPC_XO15_SCI 2720 bool "OLPC XO-1.5 SCI extras" 2721 depends on OLPC && ACPI 2722 select POWER_SUPPLY 2723 ---help--- 2724 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2725 - EC-driven system wakeups 2726 - AC adapter status updates 2727 - Battery status updates 2728 2729config ALIX 2730 bool "PCEngines ALIX System Support (LED setup)" 2731 select GPIOLIB 2732 ---help--- 2733 This option enables system support for the PCEngines ALIX. 2734 At present this just sets up LEDs for GPIO control on 2735 ALIX2/3/6 boards. However, other system specific setup should 2736 get added here. 2737 2738 Note: You must still enable the drivers for GPIO and LED support 2739 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2740 2741 Note: You have to set alix.force=1 for boards with Award BIOS. 2742 2743config NET5501 2744 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2745 select GPIOLIB 2746 ---help--- 2747 This option enables system support for the Soekris Engineering net5501. 2748 2749config GEOS 2750 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2751 select GPIOLIB 2752 depends on DMI 2753 ---help--- 2754 This option enables system support for the Traverse Technologies GEOS. 2755 2756config TS5500 2757 bool "Technologic Systems TS-5500 platform support" 2758 depends on MELAN 2759 select CHECK_SIGNATURE 2760 select NEW_LEDS 2761 select LEDS_CLASS 2762 ---help--- 2763 This option enables system support for the Technologic Systems TS-5500. 2764 2765endif # X86_32 2766 2767config AMD_NB 2768 def_bool y 2769 depends on CPU_SUP_AMD && PCI 2770 2771source "drivers/pcmcia/Kconfig" 2772 2773config RAPIDIO 2774 tristate "RapidIO support" 2775 depends on PCI 2776 default n 2777 help 2778 If enabled this option will include drivers and the core 2779 infrastructure code to support RapidIO interconnect devices. 2780 2781source "drivers/rapidio/Kconfig" 2782 2783config X86_SYSFB 2784 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2785 help 2786 Firmwares often provide initial graphics framebuffers so the BIOS, 2787 bootloader or kernel can show basic video-output during boot for 2788 user-guidance and debugging. Historically, x86 used the VESA BIOS 2789 Extensions and EFI-framebuffers for this, which are mostly limited 2790 to x86. 2791 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2792 framebuffers so the new generic system-framebuffer drivers can be 2793 used on x86. If the framebuffer is not compatible with the generic 2794 modes, it is adverticed as fallback platform framebuffer so legacy 2795 drivers like efifb, vesafb and uvesafb can pick it up. 2796 If this option is not selected, all system framebuffers are always 2797 marked as fallback platform framebuffers as usual. 2798 2799 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2800 not be able to pick up generic system framebuffers if this option 2801 is selected. You are highly encouraged to enable simplefb as 2802 replacement if you select this option. simplefb can correctly deal 2803 with generic system framebuffers. But you should still keep vesafb 2804 and others enabled as fallback if a system framebuffer is 2805 incompatible with simplefb. 2806 2807 If unsure, say Y. 2808 2809endmenu 2810 2811 2812menu "Executable file formats / Emulations" 2813 2814source "fs/Kconfig.binfmt" 2815 2816config IA32_EMULATION 2817 bool "IA32 Emulation" 2818 depends on X86_64 2819 select ARCH_WANT_OLD_COMPAT_IPC 2820 select BINFMT_ELF 2821 select COMPAT_BINFMT_ELF 2822 select COMPAT_OLD_SIGACTION 2823 ---help--- 2824 Include code to run legacy 32-bit programs under a 2825 64-bit kernel. You should likely turn this on, unless you're 2826 100% sure that you don't have any 32-bit programs left. 2827 2828config IA32_AOUT 2829 tristate "IA32 a.out support" 2830 depends on IA32_EMULATION 2831 ---help--- 2832 Support old a.out binaries in the 32bit emulation. 2833 2834config X86_X32 2835 bool "x32 ABI for 64-bit mode" 2836 depends on X86_64 2837 ---help--- 2838 Include code to run binaries for the x32 native 32-bit ABI 2839 for 64-bit processors. An x32 process gets access to the 2840 full 64-bit register file and wide data path while leaving 2841 pointers at 32 bits for smaller memory footprint. 2842 2843 You will need a recent binutils (2.22 or later) with 2844 elf32_x86_64 support enabled to compile a kernel with this 2845 option set. 2846 2847config COMPAT_32 2848 def_bool y 2849 depends on IA32_EMULATION || X86_32 2850 select HAVE_UID16 2851 select OLD_SIGSUSPEND3 2852 2853config COMPAT 2854 def_bool y 2855 depends on IA32_EMULATION || X86_X32 2856 2857if COMPAT 2858config COMPAT_FOR_U64_ALIGNMENT 2859 def_bool y 2860 2861config SYSVIPC_COMPAT 2862 def_bool y 2863 depends on SYSVIPC 2864endif 2865 2866endmenu 2867 2868 2869config HAVE_ATOMIC_IOMAP 2870 def_bool y 2871 depends on X86_32 2872 2873config X86_DEV_DMA_OPS 2874 bool 2875 depends on X86_64 || STA2X11 2876 2877config X86_DMA_REMAP 2878 bool 2879 depends on STA2X11 2880 2881config HAVE_GENERIC_GUP 2882 def_bool y 2883 2884source "net/Kconfig" 2885 2886source "drivers/Kconfig" 2887 2888source "drivers/firmware/Kconfig" 2889 2890source "fs/Kconfig" 2891 2892source "arch/x86/Kconfig.debug" 2893 2894source "security/Kconfig" 2895 2896source "crypto/Kconfig" 2897 2898source "arch/x86/kvm/Kconfig" 2899 2900source "lib/Kconfig" 2901