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 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 930 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 931 default "1" if !SMP 932 default "8192" if MAXSMP 933 default "32" if SMP && X86_BIGSMP 934 default "8" if SMP && X86_32 935 default "64" if SMP 936 ---help--- 937 This allows you to specify the maximum number of CPUs which this 938 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 939 supported value is 8192, otherwise the maximum value is 512. The 940 minimum value which makes sense is 2. 941 942 This is purely to save memory - each supported CPU adds 943 approximately eight kilobytes to the kernel image. 944 945config SCHED_SMT 946 bool "SMT (Hyperthreading) scheduler support" 947 depends on SMP 948 ---help--- 949 SMT scheduler support improves the CPU scheduler's decision making 950 when dealing with Intel Pentium 4 chips with HyperThreading at a 951 cost of slightly increased overhead in some places. If unsure say 952 N here. 953 954config SCHED_MC 955 def_bool y 956 prompt "Multi-core scheduler support" 957 depends on SMP 958 ---help--- 959 Multi-core scheduler support improves the CPU scheduler's decision 960 making when dealing with multi-core CPU chips at a cost of slightly 961 increased overhead in some places. If unsure say N here. 962 963config SCHED_MC_PRIO 964 bool "CPU core priorities scheduler support" 965 depends on SCHED_MC && CPU_SUP_INTEL 966 select X86_INTEL_PSTATE 967 select CPU_FREQ 968 default y 969 ---help--- 970 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 971 core ordering determined at manufacturing time, which allows 972 certain cores to reach higher turbo frequencies (when running 973 single threaded workloads) than others. 974 975 Enabling this kernel feature teaches the scheduler about 976 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 977 scheduler's CPU selection logic accordingly, so that higher 978 overall system performance can be achieved. 979 980 This feature will have no effect on CPUs without this feature. 981 982 If unsure say Y here. 983 984source "kernel/Kconfig.preempt" 985 986config UP_LATE_INIT 987 def_bool y 988 depends on !SMP && X86_LOCAL_APIC 989 990config X86_UP_APIC 991 bool "Local APIC support on uniprocessors" if !PCI_MSI 992 default PCI_MSI 993 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 994 ---help--- 995 A local APIC (Advanced Programmable Interrupt Controller) is an 996 integrated interrupt controller in the CPU. If you have a single-CPU 997 system which has a processor with a local APIC, you can say Y here to 998 enable and use it. If you say Y here even though your machine doesn't 999 have a local APIC, then the kernel will still run with no slowdown at 1000 all. The local APIC supports CPU-generated self-interrupts (timer, 1001 performance counters), and the NMI watchdog which detects hard 1002 lockups. 1003 1004config X86_UP_IOAPIC 1005 bool "IO-APIC support on uniprocessors" 1006 depends on X86_UP_APIC 1007 ---help--- 1008 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1009 SMP-capable replacement for PC-style interrupt controllers. Most 1010 SMP systems and many recent uniprocessor systems have one. 1011 1012 If you have a single-CPU system with an IO-APIC, you can say Y here 1013 to use it. If you say Y here even though your machine doesn't have 1014 an IO-APIC, then the kernel will still run with no slowdown at all. 1015 1016config X86_LOCAL_APIC 1017 def_bool y 1018 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1019 select IRQ_DOMAIN_HIERARCHY 1020 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1021 1022config X86_IO_APIC 1023 def_bool y 1024 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1025 1026config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1027 bool "Reroute for broken boot IRQs" 1028 depends on X86_IO_APIC 1029 ---help--- 1030 This option enables a workaround that fixes a source of 1031 spurious interrupts. This is recommended when threaded 1032 interrupt handling is used on systems where the generation of 1033 superfluous "boot interrupts" cannot be disabled. 1034 1035 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1036 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1037 kernel does during interrupt handling). On chipsets where this 1038 boot IRQ generation cannot be disabled, this workaround keeps 1039 the original IRQ line masked so that only the equivalent "boot 1040 IRQ" is delivered to the CPUs. The workaround also tells the 1041 kernel to set up the IRQ handler on the boot IRQ line. In this 1042 way only one interrupt is delivered to the kernel. Otherwise 1043 the spurious second interrupt may cause the kernel to bring 1044 down (vital) interrupt lines. 1045 1046 Only affects "broken" chipsets. Interrupt sharing may be 1047 increased on these systems. 1048 1049config X86_MCE 1050 bool "Machine Check / overheating reporting" 1051 select GENERIC_ALLOCATOR 1052 default y 1053 ---help--- 1054 Machine Check support allows the processor to notify the 1055 kernel if it detects a problem (e.g. overheating, data corruption). 1056 The action the kernel takes depends on the severity of the problem, 1057 ranging from warning messages to halting the machine. 1058 1059config X86_MCELOG_LEGACY 1060 bool "Support for deprecated /dev/mcelog character device" 1061 depends on X86_MCE 1062 ---help--- 1063 Enable support for /dev/mcelog which is needed by the old mcelog 1064 userspace logging daemon. Consider switching to the new generation 1065 rasdaemon solution. 1066 1067config X86_MCE_INTEL 1068 def_bool y 1069 prompt "Intel MCE features" 1070 depends on X86_MCE && X86_LOCAL_APIC 1071 ---help--- 1072 Additional support for intel specific MCE features such as 1073 the thermal monitor. 1074 1075config X86_MCE_AMD 1076 def_bool y 1077 prompt "AMD MCE features" 1078 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1079 ---help--- 1080 Additional support for AMD specific MCE features such as 1081 the DRAM Error Threshold. 1082 1083config X86_ANCIENT_MCE 1084 bool "Support for old Pentium 5 / WinChip machine checks" 1085 depends on X86_32 && X86_MCE 1086 ---help--- 1087 Include support for machine check handling on old Pentium 5 or WinChip 1088 systems. These typically need to be enabled explicitly on the command 1089 line. 1090 1091config X86_MCE_THRESHOLD 1092 depends on X86_MCE_AMD || X86_MCE_INTEL 1093 def_bool y 1094 1095config X86_MCE_INJECT 1096 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1097 tristate "Machine check injector support" 1098 ---help--- 1099 Provide support for injecting machine checks for testing purposes. 1100 If you don't know what a machine check is and you don't do kernel 1101 QA it is safe to say n. 1102 1103config X86_THERMAL_VECTOR 1104 def_bool y 1105 depends on X86_MCE_INTEL 1106 1107source "arch/x86/events/Kconfig" 1108 1109config X86_LEGACY_VM86 1110 bool "Legacy VM86 support" 1111 default n 1112 depends on X86_32 1113 ---help--- 1114 This option allows user programs to put the CPU into V8086 1115 mode, which is an 80286-era approximation of 16-bit real mode. 1116 1117 Some very old versions of X and/or vbetool require this option 1118 for user mode setting. Similarly, DOSEMU will use it if 1119 available to accelerate real mode DOS programs. However, any 1120 recent version of DOSEMU, X, or vbetool should be fully 1121 functional even without kernel VM86 support, as they will all 1122 fall back to software emulation. Nevertheless, if you are using 1123 a 16-bit DOS program where 16-bit performance matters, vm86 1124 mode might be faster than emulation and you might want to 1125 enable this option. 1126 1127 Note that any app that works on a 64-bit kernel is unlikely to 1128 need this option, as 64-bit kernels don't, and can't, support 1129 V8086 mode. This option is also unrelated to 16-bit protected 1130 mode and is not needed to run most 16-bit programs under Wine. 1131 1132 Enabling this option increases the complexity of the kernel 1133 and slows down exception handling a tiny bit. 1134 1135 If unsure, say N here. 1136 1137config VM86 1138 bool 1139 default X86_LEGACY_VM86 1140 1141config X86_16BIT 1142 bool "Enable support for 16-bit segments" if EXPERT 1143 default y 1144 depends on MODIFY_LDT_SYSCALL 1145 ---help--- 1146 This option is required by programs like Wine to run 16-bit 1147 protected mode legacy code on x86 processors. Disabling 1148 this option saves about 300 bytes on i386, or around 6K text 1149 plus 16K runtime memory on x86-64, 1150 1151config X86_ESPFIX32 1152 def_bool y 1153 depends on X86_16BIT && X86_32 1154 1155config X86_ESPFIX64 1156 def_bool y 1157 depends on X86_16BIT && X86_64 1158 1159config X86_VSYSCALL_EMULATION 1160 bool "Enable vsyscall emulation" if EXPERT 1161 default y 1162 depends on X86_64 1163 ---help--- 1164 This enables emulation of the legacy vsyscall page. Disabling 1165 it is roughly equivalent to booting with vsyscall=none, except 1166 that it will also disable the helpful warning if a program 1167 tries to use a vsyscall. With this option set to N, offending 1168 programs will just segfault, citing addresses of the form 1169 0xffffffffff600?00. 1170 1171 This option is required by many programs built before 2013, and 1172 care should be used even with newer programs if set to N. 1173 1174 Disabling this option saves about 7K of kernel size and 1175 possibly 4K of additional runtime pagetable memory. 1176 1177config TOSHIBA 1178 tristate "Toshiba Laptop support" 1179 depends on X86_32 1180 ---help--- 1181 This adds a driver to safely access the System Management Mode of 1182 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1183 not work on models with a Phoenix BIOS. The System Management Mode 1184 is used to set the BIOS and power saving options on Toshiba portables. 1185 1186 For information on utilities to make use of this driver see the 1187 Toshiba Linux utilities web site at: 1188 <http://www.buzzard.org.uk/toshiba/>. 1189 1190 Say Y if you intend to run this kernel on a Toshiba portable. 1191 Say N otherwise. 1192 1193config I8K 1194 tristate "Dell i8k legacy laptop support" 1195 select HWMON 1196 select SENSORS_DELL_SMM 1197 ---help--- 1198 This option enables legacy /proc/i8k userspace interface in hwmon 1199 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1200 temperature and allows controlling fan speeds of Dell laptops via 1201 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1202 it reports also power and hotkey status. For fan speed control is 1203 needed userspace package i8kutils. 1204 1205 Say Y if you intend to run this kernel on old Dell laptops or want to 1206 use userspace package i8kutils. 1207 Say N otherwise. 1208 1209config X86_REBOOTFIXUPS 1210 bool "Enable X86 board specific fixups for reboot" 1211 depends on X86_32 1212 ---help--- 1213 This enables chipset and/or board specific fixups to be done 1214 in order to get reboot to work correctly. This is only needed on 1215 some combinations of hardware and BIOS. The symptom, for which 1216 this config is intended, is when reboot ends with a stalled/hung 1217 system. 1218 1219 Currently, the only fixup is for the Geode machines using 1220 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1221 1222 Say Y if you want to enable the fixup. Currently, it's safe to 1223 enable this option even if you don't need it. 1224 Say N otherwise. 1225 1226config MICROCODE 1227 bool "CPU microcode loading support" 1228 default y 1229 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1230 select FW_LOADER 1231 ---help--- 1232 If you say Y here, you will be able to update the microcode on 1233 Intel and AMD processors. The Intel support is for the IA32 family, 1234 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1235 AMD support is for families 0x10 and later. You will obviously need 1236 the actual microcode binary data itself which is not shipped with 1237 the Linux kernel. 1238 1239 The preferred method to load microcode from a detached initrd is described 1240 in Documentation/x86/early-microcode.txt. For that you need to enable 1241 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1242 initrd for microcode blobs. 1243 1244 In addition, you can build-in the microcode into the kernel. For that you 1245 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1246 to the CONFIG_EXTRA_FIRMWARE config option. 1247 1248config MICROCODE_INTEL 1249 bool "Intel microcode loading support" 1250 depends on MICROCODE 1251 default MICROCODE 1252 select FW_LOADER 1253 ---help--- 1254 This options enables microcode patch loading support for Intel 1255 processors. 1256 1257 For the current Intel microcode data package go to 1258 <https://downloadcenter.intel.com> and search for 1259 'Linux Processor Microcode Data File'. 1260 1261config MICROCODE_AMD 1262 bool "AMD microcode loading support" 1263 depends on MICROCODE 1264 select FW_LOADER 1265 ---help--- 1266 If you select this option, microcode patch loading support for AMD 1267 processors will be enabled. 1268 1269config MICROCODE_OLD_INTERFACE 1270 def_bool y 1271 depends on MICROCODE 1272 1273config X86_MSR 1274 tristate "/dev/cpu/*/msr - Model-specific register support" 1275 ---help--- 1276 This device gives privileged processes access to the x86 1277 Model-Specific Registers (MSRs). It is a character device with 1278 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1279 MSR accesses are directed to a specific CPU on multi-processor 1280 systems. 1281 1282config X86_CPUID 1283 tristate "/dev/cpu/*/cpuid - CPU information support" 1284 ---help--- 1285 This device gives processes access to the x86 CPUID instruction to 1286 be executed on a specific processor. It is a character device 1287 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1288 /dev/cpu/31/cpuid. 1289 1290choice 1291 prompt "High Memory Support" 1292 default HIGHMEM4G 1293 depends on X86_32 1294 1295config NOHIGHMEM 1296 bool "off" 1297 ---help--- 1298 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1299 However, the address space of 32-bit x86 processors is only 4 1300 Gigabytes large. That means that, if you have a large amount of 1301 physical memory, not all of it can be "permanently mapped" by the 1302 kernel. The physical memory that's not permanently mapped is called 1303 "high memory". 1304 1305 If you are compiling a kernel which will never run on a machine with 1306 more than 1 Gigabyte total physical RAM, answer "off" here (default 1307 choice and suitable for most users). This will result in a "3GB/1GB" 1308 split: 3GB are mapped so that each process sees a 3GB virtual memory 1309 space and the remaining part of the 4GB virtual memory space is used 1310 by the kernel to permanently map as much physical memory as 1311 possible. 1312 1313 If the machine has between 1 and 4 Gigabytes physical RAM, then 1314 answer "4GB" here. 1315 1316 If more than 4 Gigabytes is used then answer "64GB" here. This 1317 selection turns Intel PAE (Physical Address Extension) mode on. 1318 PAE implements 3-level paging on IA32 processors. PAE is fully 1319 supported by Linux, PAE mode is implemented on all recent Intel 1320 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1321 then the kernel will not boot on CPUs that don't support PAE! 1322 1323 The actual amount of total physical memory will either be 1324 auto detected or can be forced by using a kernel command line option 1325 such as "mem=256M". (Try "man bootparam" or see the documentation of 1326 your boot loader (lilo or loadlin) about how to pass options to the 1327 kernel at boot time.) 1328 1329 If unsure, say "off". 1330 1331config HIGHMEM4G 1332 bool "4GB" 1333 ---help--- 1334 Select this if you have a 32-bit processor and between 1 and 4 1335 gigabytes of physical RAM. 1336 1337config HIGHMEM64G 1338 bool "64GB" 1339 depends on !M486 1340 select X86_PAE 1341 ---help--- 1342 Select this if you have a 32-bit processor and more than 4 1343 gigabytes of physical RAM. 1344 1345endchoice 1346 1347choice 1348 prompt "Memory split" if EXPERT 1349 default VMSPLIT_3G 1350 depends on X86_32 1351 ---help--- 1352 Select the desired split between kernel and user memory. 1353 1354 If the address range available to the kernel is less than the 1355 physical memory installed, the remaining memory will be available 1356 as "high memory". Accessing high memory is a little more costly 1357 than low memory, as it needs to be mapped into the kernel first. 1358 Note that increasing the kernel address space limits the range 1359 available to user programs, making the address space there 1360 tighter. Selecting anything other than the default 3G/1G split 1361 will also likely make your kernel incompatible with binary-only 1362 kernel modules. 1363 1364 If you are not absolutely sure what you are doing, leave this 1365 option alone! 1366 1367 config VMSPLIT_3G 1368 bool "3G/1G user/kernel split" 1369 config VMSPLIT_3G_OPT 1370 depends on !X86_PAE 1371 bool "3G/1G user/kernel split (for full 1G low memory)" 1372 config VMSPLIT_2G 1373 bool "2G/2G user/kernel split" 1374 config VMSPLIT_2G_OPT 1375 depends on !X86_PAE 1376 bool "2G/2G user/kernel split (for full 2G low memory)" 1377 config VMSPLIT_1G 1378 bool "1G/3G user/kernel split" 1379endchoice 1380 1381config PAGE_OFFSET 1382 hex 1383 default 0xB0000000 if VMSPLIT_3G_OPT 1384 default 0x80000000 if VMSPLIT_2G 1385 default 0x78000000 if VMSPLIT_2G_OPT 1386 default 0x40000000 if VMSPLIT_1G 1387 default 0xC0000000 1388 depends on X86_32 1389 1390config HIGHMEM 1391 def_bool y 1392 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1393 1394config X86_PAE 1395 bool "PAE (Physical Address Extension) Support" 1396 depends on X86_32 && !HIGHMEM4G 1397 select SWIOTLB 1398 ---help--- 1399 PAE is required for NX support, and furthermore enables 1400 larger swapspace support for non-overcommit purposes. It 1401 has the cost of more pagetable lookup overhead, and also 1402 consumes more pagetable space per process. 1403 1404config X86_5LEVEL 1405 bool "Enable 5-level page tables support" 1406 depends on X86_64 1407 ---help--- 1408 5-level paging enables access to larger address space: 1409 upto 128 PiB of virtual address space and 4 PiB of 1410 physical address space. 1411 1412 It will be supported by future Intel CPUs. 1413 1414 Note: a kernel with this option enabled can only be booted 1415 on machines that support the feature. 1416 1417 See Documentation/x86/x86_64/5level-paging.txt for more 1418 information. 1419 1420 Say N if unsure. 1421 1422config ARCH_PHYS_ADDR_T_64BIT 1423 def_bool y 1424 depends on X86_64 || X86_PAE 1425 1426config ARCH_DMA_ADDR_T_64BIT 1427 def_bool y 1428 depends on X86_64 || HIGHMEM64G 1429 1430config X86_DIRECT_GBPAGES 1431 def_bool y 1432 depends on X86_64 && !DEBUG_PAGEALLOC 1433 ---help--- 1434 Certain kernel features effectively disable kernel 1435 linear 1 GB mappings (even if the CPU otherwise 1436 supports them), so don't confuse the user by printing 1437 that we have them enabled. 1438 1439config ARCH_HAS_MEM_ENCRYPT 1440 def_bool y 1441 1442config AMD_MEM_ENCRYPT 1443 bool "AMD Secure Memory Encryption (SME) support" 1444 depends on X86_64 && CPU_SUP_AMD 1445 ---help--- 1446 Say yes to enable support for the encryption of system memory. 1447 This requires an AMD processor that supports Secure Memory 1448 Encryption (SME). 1449 1450config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1451 bool "Activate AMD Secure Memory Encryption (SME) by default" 1452 default y 1453 depends on AMD_MEM_ENCRYPT 1454 ---help--- 1455 Say yes to have system memory encrypted by default if running on 1456 an AMD processor that supports Secure Memory Encryption (SME). 1457 1458 If set to Y, then the encryption of system memory can be 1459 deactivated with the mem_encrypt=off command line option. 1460 1461 If set to N, then the encryption of system memory can be 1462 activated with the mem_encrypt=on command line option. 1463 1464config ARCH_USE_MEMREMAP_PROT 1465 def_bool y 1466 depends on AMD_MEM_ENCRYPT 1467 1468# Common NUMA Features 1469config NUMA 1470 bool "Numa Memory Allocation and Scheduler Support" 1471 depends on SMP 1472 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1473 default y if X86_BIGSMP 1474 ---help--- 1475 Enable NUMA (Non Uniform Memory Access) support. 1476 1477 The kernel will try to allocate memory used by a CPU on the 1478 local memory controller of the CPU and add some more 1479 NUMA awareness to the kernel. 1480 1481 For 64-bit this is recommended if the system is Intel Core i7 1482 (or later), AMD Opteron, or EM64T NUMA. 1483 1484 For 32-bit this is only needed if you boot a 32-bit 1485 kernel on a 64-bit NUMA platform. 1486 1487 Otherwise, you should say N. 1488 1489config AMD_NUMA 1490 def_bool y 1491 prompt "Old style AMD Opteron NUMA detection" 1492 depends on X86_64 && NUMA && PCI 1493 ---help--- 1494 Enable AMD NUMA node topology detection. You should say Y here if 1495 you have a multi processor AMD system. This uses an old method to 1496 read the NUMA configuration directly from the builtin Northbridge 1497 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1498 which also takes priority if both are compiled in. 1499 1500config X86_64_ACPI_NUMA 1501 def_bool y 1502 prompt "ACPI NUMA detection" 1503 depends on X86_64 && NUMA && ACPI && PCI 1504 select ACPI_NUMA 1505 ---help--- 1506 Enable ACPI SRAT based node topology detection. 1507 1508# Some NUMA nodes have memory ranges that span 1509# other nodes. Even though a pfn is valid and 1510# between a node's start and end pfns, it may not 1511# reside on that node. See memmap_init_zone() 1512# for details. 1513config NODES_SPAN_OTHER_NODES 1514 def_bool y 1515 depends on X86_64_ACPI_NUMA 1516 1517config NUMA_EMU 1518 bool "NUMA emulation" 1519 depends on NUMA 1520 ---help--- 1521 Enable NUMA emulation. A flat machine will be split 1522 into virtual nodes when booted with "numa=fake=N", where N is the 1523 number of nodes. This is only useful for debugging. 1524 1525config NODES_SHIFT 1526 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1527 range 1 10 1528 default "10" if MAXSMP 1529 default "6" if X86_64 1530 default "3" 1531 depends on NEED_MULTIPLE_NODES 1532 ---help--- 1533 Specify the maximum number of NUMA Nodes available on the target 1534 system. Increases memory reserved to accommodate various tables. 1535 1536config ARCH_HAVE_MEMORY_PRESENT 1537 def_bool y 1538 depends on X86_32 && DISCONTIGMEM 1539 1540config NEED_NODE_MEMMAP_SIZE 1541 def_bool y 1542 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1543 1544config ARCH_FLATMEM_ENABLE 1545 def_bool y 1546 depends on X86_32 && !NUMA 1547 1548config ARCH_DISCONTIGMEM_ENABLE 1549 def_bool y 1550 depends on NUMA && X86_32 1551 1552config ARCH_DISCONTIGMEM_DEFAULT 1553 def_bool y 1554 depends on NUMA && X86_32 1555 1556config ARCH_SPARSEMEM_ENABLE 1557 def_bool y 1558 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1559 select SPARSEMEM_STATIC if X86_32 1560 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1561 1562config ARCH_SPARSEMEM_DEFAULT 1563 def_bool y 1564 depends on X86_64 1565 1566config ARCH_SELECT_MEMORY_MODEL 1567 def_bool y 1568 depends on ARCH_SPARSEMEM_ENABLE 1569 1570config ARCH_MEMORY_PROBE 1571 bool "Enable sysfs memory/probe interface" 1572 depends on X86_64 && MEMORY_HOTPLUG 1573 help 1574 This option enables a sysfs memory/probe interface for testing. 1575 See Documentation/memory-hotplug.txt for more information. 1576 If you are unsure how to answer this question, answer N. 1577 1578config ARCH_PROC_KCORE_TEXT 1579 def_bool y 1580 depends on X86_64 && PROC_KCORE 1581 1582config ILLEGAL_POINTER_VALUE 1583 hex 1584 default 0 if X86_32 1585 default 0xdead000000000000 if X86_64 1586 1587source "mm/Kconfig" 1588 1589config X86_PMEM_LEGACY_DEVICE 1590 bool 1591 1592config X86_PMEM_LEGACY 1593 tristate "Support non-standard NVDIMMs and ADR protected memory" 1594 depends on PHYS_ADDR_T_64BIT 1595 depends on BLK_DEV 1596 select X86_PMEM_LEGACY_DEVICE 1597 select LIBNVDIMM 1598 help 1599 Treat memory marked using the non-standard e820 type of 12 as used 1600 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1601 The kernel will offer these regions to the 'pmem' driver so 1602 they can be used for persistent storage. 1603 1604 Say Y if unsure. 1605 1606config HIGHPTE 1607 bool "Allocate 3rd-level pagetables from highmem" 1608 depends on HIGHMEM 1609 ---help--- 1610 The VM uses one page table entry for each page of physical memory. 1611 For systems with a lot of RAM, this can be wasteful of precious 1612 low memory. Setting this option will put user-space page table 1613 entries in high memory. 1614 1615config X86_CHECK_BIOS_CORRUPTION 1616 bool "Check for low memory corruption" 1617 ---help--- 1618 Periodically check for memory corruption in low memory, which 1619 is suspected to be caused by BIOS. Even when enabled in the 1620 configuration, it is disabled at runtime. Enable it by 1621 setting "memory_corruption_check=1" on the kernel command 1622 line. By default it scans the low 64k of memory every 60 1623 seconds; see the memory_corruption_check_size and 1624 memory_corruption_check_period parameters in 1625 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1626 1627 When enabled with the default parameters, this option has 1628 almost no overhead, as it reserves a relatively small amount 1629 of memory and scans it infrequently. It both detects corruption 1630 and prevents it from affecting the running system. 1631 1632 It is, however, intended as a diagnostic tool; if repeatable 1633 BIOS-originated corruption always affects the same memory, 1634 you can use memmap= to prevent the kernel from using that 1635 memory. 1636 1637config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1638 bool "Set the default setting of memory_corruption_check" 1639 depends on X86_CHECK_BIOS_CORRUPTION 1640 default y 1641 ---help--- 1642 Set whether the default state of memory_corruption_check is 1643 on or off. 1644 1645config X86_RESERVE_LOW 1646 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1647 default 64 1648 range 4 640 1649 ---help--- 1650 Specify the amount of low memory to reserve for the BIOS. 1651 1652 The first page contains BIOS data structures that the kernel 1653 must not use, so that page must always be reserved. 1654 1655 By default we reserve the first 64K of physical RAM, as a 1656 number of BIOSes are known to corrupt that memory range 1657 during events such as suspend/resume or monitor cable 1658 insertion, so it must not be used by the kernel. 1659 1660 You can set this to 4 if you are absolutely sure that you 1661 trust the BIOS to get all its memory reservations and usages 1662 right. If you know your BIOS have problems beyond the 1663 default 64K area, you can set this to 640 to avoid using the 1664 entire low memory range. 1665 1666 If you have doubts about the BIOS (e.g. suspend/resume does 1667 not work or there's kernel crashes after certain hardware 1668 hotplug events) then you might want to enable 1669 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1670 typical corruption patterns. 1671 1672 Leave this to the default value of 64 if you are unsure. 1673 1674config MATH_EMULATION 1675 bool 1676 depends on MODIFY_LDT_SYSCALL 1677 prompt "Math emulation" if X86_32 1678 ---help--- 1679 Linux can emulate a math coprocessor (used for floating point 1680 operations) if you don't have one. 486DX and Pentium processors have 1681 a math coprocessor built in, 486SX and 386 do not, unless you added 1682 a 487DX or 387, respectively. (The messages during boot time can 1683 give you some hints here ["man dmesg"].) Everyone needs either a 1684 coprocessor or this emulation. 1685 1686 If you don't have a math coprocessor, you need to say Y here; if you 1687 say Y here even though you have a coprocessor, the coprocessor will 1688 be used nevertheless. (This behavior can be changed with the kernel 1689 command line option "no387", which comes handy if your coprocessor 1690 is broken. Try "man bootparam" or see the documentation of your boot 1691 loader (lilo or loadlin) about how to pass options to the kernel at 1692 boot time.) This means that it is a good idea to say Y here if you 1693 intend to use this kernel on different machines. 1694 1695 More information about the internals of the Linux math coprocessor 1696 emulation can be found in <file:arch/x86/math-emu/README>. 1697 1698 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1699 kernel, it won't hurt. 1700 1701config MTRR 1702 def_bool y 1703 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1704 ---help--- 1705 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1706 the Memory Type Range Registers (MTRRs) may be used to control 1707 processor access to memory ranges. This is most useful if you have 1708 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1709 allows bus write transfers to be combined into a larger transfer 1710 before bursting over the PCI/AGP bus. This can increase performance 1711 of image write operations 2.5 times or more. Saying Y here creates a 1712 /proc/mtrr file which may be used to manipulate your processor's 1713 MTRRs. Typically the X server should use this. 1714 1715 This code has a reasonably generic interface so that similar 1716 control registers on other processors can be easily supported 1717 as well: 1718 1719 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1720 Registers (ARRs) which provide a similar functionality to MTRRs. For 1721 these, the ARRs are used to emulate the MTRRs. 1722 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1723 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1724 write-combining. All of these processors are supported by this code 1725 and it makes sense to say Y here if you have one of them. 1726 1727 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1728 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1729 can lead to all sorts of problems, so it's good to say Y here. 1730 1731 You can safely say Y even if your machine doesn't have MTRRs, you'll 1732 just add about 9 KB to your kernel. 1733 1734 See <file:Documentation/x86/mtrr.txt> for more information. 1735 1736config MTRR_SANITIZER 1737 def_bool y 1738 prompt "MTRR cleanup support" 1739 depends on MTRR 1740 ---help--- 1741 Convert MTRR layout from continuous to discrete, so X drivers can 1742 add writeback entries. 1743 1744 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1745 The largest mtrr entry size for a continuous block can be set with 1746 mtrr_chunk_size. 1747 1748 If unsure, say Y. 1749 1750config MTRR_SANITIZER_ENABLE_DEFAULT 1751 int "MTRR cleanup enable value (0-1)" 1752 range 0 1 1753 default "0" 1754 depends on MTRR_SANITIZER 1755 ---help--- 1756 Enable mtrr cleanup default value 1757 1758config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1759 int "MTRR cleanup spare reg num (0-7)" 1760 range 0 7 1761 default "1" 1762 depends on MTRR_SANITIZER 1763 ---help--- 1764 mtrr cleanup spare entries default, it can be changed via 1765 mtrr_spare_reg_nr=N on the kernel command line. 1766 1767config X86_PAT 1768 def_bool y 1769 prompt "x86 PAT support" if EXPERT 1770 depends on MTRR 1771 ---help--- 1772 Use PAT attributes to setup page level cache control. 1773 1774 PATs are the modern equivalents of MTRRs and are much more 1775 flexible than MTRRs. 1776 1777 Say N here if you see bootup problems (boot crash, boot hang, 1778 spontaneous reboots) or a non-working video driver. 1779 1780 If unsure, say Y. 1781 1782config ARCH_USES_PG_UNCACHED 1783 def_bool y 1784 depends on X86_PAT 1785 1786config ARCH_RANDOM 1787 def_bool y 1788 prompt "x86 architectural random number generator" if EXPERT 1789 ---help--- 1790 Enable the x86 architectural RDRAND instruction 1791 (Intel Bull Mountain technology) to generate random numbers. 1792 If supported, this is a high bandwidth, cryptographically 1793 secure hardware random number generator. 1794 1795config X86_SMAP 1796 def_bool y 1797 prompt "Supervisor Mode Access Prevention" if EXPERT 1798 ---help--- 1799 Supervisor Mode Access Prevention (SMAP) is a security 1800 feature in newer Intel processors. There is a small 1801 performance cost if this enabled and turned on; there is 1802 also a small increase in the kernel size if this is enabled. 1803 1804 If unsure, say Y. 1805 1806config X86_INTEL_UMIP 1807 def_bool n 1808 depends on CPU_SUP_INTEL 1809 prompt "Intel User Mode Instruction Prevention" if EXPERT 1810 ---help--- 1811 The User Mode Instruction Prevention (UMIP) is a security 1812 feature in newer Intel processors. If enabled, a general 1813 protection fault is issued if the instructions SGDT, SLDT, 1814 SIDT, SMSW and STR are executed in user mode. 1815 1816config X86_INTEL_MPX 1817 prompt "Intel MPX (Memory Protection Extensions)" 1818 def_bool n 1819 # Note: only available in 64-bit mode due to VMA flags shortage 1820 depends on CPU_SUP_INTEL && X86_64 1821 select ARCH_USES_HIGH_VMA_FLAGS 1822 ---help--- 1823 MPX provides hardware features that can be used in 1824 conjunction with compiler-instrumented code to check 1825 memory references. It is designed to detect buffer 1826 overflow or underflow bugs. 1827 1828 This option enables running applications which are 1829 instrumented or otherwise use MPX. It does not use MPX 1830 itself inside the kernel or to protect the kernel 1831 against bad memory references. 1832 1833 Enabling this option will make the kernel larger: 1834 ~8k of kernel text and 36 bytes of data on a 64-bit 1835 defconfig. It adds a long to the 'mm_struct' which 1836 will increase the kernel memory overhead of each 1837 process and adds some branches to paths used during 1838 exec() and munmap(). 1839 1840 For details, see Documentation/x86/intel_mpx.txt 1841 1842 If unsure, say N. 1843 1844config X86_INTEL_MEMORY_PROTECTION_KEYS 1845 prompt "Intel Memory Protection Keys" 1846 def_bool y 1847 # Note: only available in 64-bit mode 1848 depends on CPU_SUP_INTEL && X86_64 1849 select ARCH_USES_HIGH_VMA_FLAGS 1850 select ARCH_HAS_PKEYS 1851 ---help--- 1852 Memory Protection Keys provides a mechanism for enforcing 1853 page-based protections, but without requiring modification of the 1854 page tables when an application changes protection domains. 1855 1856 For details, see Documentation/x86/protection-keys.txt 1857 1858 If unsure, say y. 1859 1860config EFI 1861 bool "EFI runtime service support" 1862 depends on ACPI 1863 select UCS2_STRING 1864 select EFI_RUNTIME_WRAPPERS 1865 ---help--- 1866 This enables the kernel to use EFI runtime services that are 1867 available (such as the EFI variable services). 1868 1869 This option is only useful on systems that have EFI firmware. 1870 In addition, you should use the latest ELILO loader available 1871 at <http://elilo.sourceforge.net> in order to take advantage 1872 of EFI runtime services. However, even with this option, the 1873 resultant kernel should continue to boot on existing non-EFI 1874 platforms. 1875 1876config EFI_STUB 1877 bool "EFI stub support" 1878 depends on EFI && !X86_USE_3DNOW 1879 select RELOCATABLE 1880 ---help--- 1881 This kernel feature allows a bzImage to be loaded directly 1882 by EFI firmware without the use of a bootloader. 1883 1884 See Documentation/efi-stub.txt for more information. 1885 1886config EFI_MIXED 1887 bool "EFI mixed-mode support" 1888 depends on EFI_STUB && X86_64 1889 ---help--- 1890 Enabling this feature allows a 64-bit kernel to be booted 1891 on a 32-bit firmware, provided that your CPU supports 64-bit 1892 mode. 1893 1894 Note that it is not possible to boot a mixed-mode enabled 1895 kernel via the EFI boot stub - a bootloader that supports 1896 the EFI handover protocol must be used. 1897 1898 If unsure, say N. 1899 1900config SECCOMP 1901 def_bool y 1902 prompt "Enable seccomp to safely compute untrusted bytecode" 1903 ---help--- 1904 This kernel feature is useful for number crunching applications 1905 that may need to compute untrusted bytecode during their 1906 execution. By using pipes or other transports made available to 1907 the process as file descriptors supporting the read/write 1908 syscalls, it's possible to isolate those applications in 1909 their own address space using seccomp. Once seccomp is 1910 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1911 and the task is only allowed to execute a few safe syscalls 1912 defined by each seccomp mode. 1913 1914 If unsure, say Y. Only embedded should say N here. 1915 1916source kernel/Kconfig.hz 1917 1918config KEXEC 1919 bool "kexec system call" 1920 select KEXEC_CORE 1921 ---help--- 1922 kexec is a system call that implements the ability to shutdown your 1923 current kernel, and to start another kernel. It is like a reboot 1924 but it is independent of the system firmware. And like a reboot 1925 you can start any kernel with it, not just Linux. 1926 1927 The name comes from the similarity to the exec system call. 1928 1929 It is an ongoing process to be certain the hardware in a machine 1930 is properly shutdown, so do not be surprised if this code does not 1931 initially work for you. As of this writing the exact hardware 1932 interface is strongly in flux, so no good recommendation can be 1933 made. 1934 1935config KEXEC_FILE 1936 bool "kexec file based system call" 1937 select KEXEC_CORE 1938 select BUILD_BIN2C 1939 depends on X86_64 1940 depends on CRYPTO=y 1941 depends on CRYPTO_SHA256=y 1942 ---help--- 1943 This is new version of kexec system call. This system call is 1944 file based and takes file descriptors as system call argument 1945 for kernel and initramfs as opposed to list of segments as 1946 accepted by previous system call. 1947 1948config KEXEC_VERIFY_SIG 1949 bool "Verify kernel signature during kexec_file_load() syscall" 1950 depends on KEXEC_FILE 1951 ---help--- 1952 This option makes kernel signature verification mandatory for 1953 the kexec_file_load() syscall. 1954 1955 In addition to that option, you need to enable signature 1956 verification for the corresponding kernel image type being 1957 loaded in order for this to work. 1958 1959config KEXEC_BZIMAGE_VERIFY_SIG 1960 bool "Enable bzImage signature verification support" 1961 depends on KEXEC_VERIFY_SIG 1962 depends on SIGNED_PE_FILE_VERIFICATION 1963 select SYSTEM_TRUSTED_KEYRING 1964 ---help--- 1965 Enable bzImage signature verification support. 1966 1967config CRASH_DUMP 1968 bool "kernel crash dumps" 1969 depends on X86_64 || (X86_32 && HIGHMEM) 1970 ---help--- 1971 Generate crash dump after being started by kexec. 1972 This should be normally only set in special crash dump kernels 1973 which are loaded in the main kernel with kexec-tools into 1974 a specially reserved region and then later executed after 1975 a crash by kdump/kexec. The crash dump kernel must be compiled 1976 to a memory address not used by the main kernel or BIOS using 1977 PHYSICAL_START, or it must be built as a relocatable image 1978 (CONFIG_RELOCATABLE=y). 1979 For more details see Documentation/kdump/kdump.txt 1980 1981config KEXEC_JUMP 1982 bool "kexec jump" 1983 depends on KEXEC && HIBERNATION 1984 ---help--- 1985 Jump between original kernel and kexeced kernel and invoke 1986 code in physical address mode via KEXEC 1987 1988config PHYSICAL_START 1989 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1990 default "0x1000000" 1991 ---help--- 1992 This gives the physical address where the kernel is loaded. 1993 1994 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1995 bzImage will decompress itself to above physical address and 1996 run from there. Otherwise, bzImage will run from the address where 1997 it has been loaded by the boot loader and will ignore above physical 1998 address. 1999 2000 In normal kdump cases one does not have to set/change this option 2001 as now bzImage can be compiled as a completely relocatable image 2002 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2003 address. This option is mainly useful for the folks who don't want 2004 to use a bzImage for capturing the crash dump and want to use a 2005 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2006 to be specifically compiled to run from a specific memory area 2007 (normally a reserved region) and this option comes handy. 2008 2009 So if you are using bzImage for capturing the crash dump, 2010 leave the value here unchanged to 0x1000000 and set 2011 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2012 for capturing the crash dump change this value to start of 2013 the reserved region. In other words, it can be set based on 2014 the "X" value as specified in the "crashkernel=YM@XM" 2015 command line boot parameter passed to the panic-ed 2016 kernel. Please take a look at Documentation/kdump/kdump.txt 2017 for more details about crash dumps. 2018 2019 Usage of bzImage for capturing the crash dump is recommended as 2020 one does not have to build two kernels. Same kernel can be used 2021 as production kernel and capture kernel. Above option should have 2022 gone away after relocatable bzImage support is introduced. But it 2023 is present because there are users out there who continue to use 2024 vmlinux for dump capture. This option should go away down the 2025 line. 2026 2027 Don't change this unless you know what you are doing. 2028 2029config RELOCATABLE 2030 bool "Build a relocatable kernel" 2031 default y 2032 ---help--- 2033 This builds a kernel image that retains relocation information 2034 so it can be loaded someplace besides the default 1MB. 2035 The relocations tend to make the kernel binary about 10% larger, 2036 but are discarded at runtime. 2037 2038 One use is for the kexec on panic case where the recovery kernel 2039 must live at a different physical address than the primary 2040 kernel. 2041 2042 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2043 it has been loaded at and the compile time physical address 2044 (CONFIG_PHYSICAL_START) is used as the minimum location. 2045 2046config RANDOMIZE_BASE 2047 bool "Randomize the address of the kernel image (KASLR)" 2048 depends on RELOCATABLE 2049 default y 2050 ---help--- 2051 In support of Kernel Address Space Layout Randomization (KASLR), 2052 this randomizes the physical address at which the kernel image 2053 is decompressed and the virtual address where the kernel 2054 image is mapped, as a security feature that deters exploit 2055 attempts relying on knowledge of the location of kernel 2056 code internals. 2057 2058 On 64-bit, the kernel physical and virtual addresses are 2059 randomized separately. The physical address will be anywhere 2060 between 16MB and the top of physical memory (up to 64TB). The 2061 virtual address will be randomized from 16MB up to 1GB (9 bits 2062 of entropy). Note that this also reduces the memory space 2063 available to kernel modules from 1.5GB to 1GB. 2064 2065 On 32-bit, the kernel physical and virtual addresses are 2066 randomized together. They will be randomized from 16MB up to 2067 512MB (8 bits of entropy). 2068 2069 Entropy is generated using the RDRAND instruction if it is 2070 supported. If RDTSC is supported, its value is mixed into 2071 the entropy pool as well. If neither RDRAND nor RDTSC are 2072 supported, then entropy is read from the i8254 timer. The 2073 usable entropy is limited by the kernel being built using 2074 2GB addressing, and that PHYSICAL_ALIGN must be at a 2075 minimum of 2MB. As a result, only 10 bits of entropy are 2076 theoretically possible, but the implementations are further 2077 limited due to memory layouts. 2078 2079 If unsure, say Y. 2080 2081# Relocation on x86 needs some additional build support 2082config X86_NEED_RELOCS 2083 def_bool y 2084 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2085 2086config PHYSICAL_ALIGN 2087 hex "Alignment value to which kernel should be aligned" 2088 default "0x200000" 2089 range 0x2000 0x1000000 if X86_32 2090 range 0x200000 0x1000000 if X86_64 2091 ---help--- 2092 This value puts the alignment restrictions on physical address 2093 where kernel is loaded and run from. Kernel is compiled for an 2094 address which meets above alignment restriction. 2095 2096 If bootloader loads the kernel at a non-aligned address and 2097 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2098 address aligned to above value and run from there. 2099 2100 If bootloader loads the kernel at a non-aligned address and 2101 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2102 load address and decompress itself to the address it has been 2103 compiled for and run from there. The address for which kernel is 2104 compiled already meets above alignment restrictions. Hence the 2105 end result is that kernel runs from a physical address meeting 2106 above alignment restrictions. 2107 2108 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2109 this value must be a multiple of 0x200000. 2110 2111 Don't change this unless you know what you are doing. 2112 2113config RANDOMIZE_MEMORY 2114 bool "Randomize the kernel memory sections" 2115 depends on X86_64 2116 depends on RANDOMIZE_BASE 2117 default RANDOMIZE_BASE 2118 ---help--- 2119 Randomizes the base virtual address of kernel memory sections 2120 (physical memory mapping, vmalloc & vmemmap). This security feature 2121 makes exploits relying on predictable memory locations less reliable. 2122 2123 The order of allocations remains unchanged. Entropy is generated in 2124 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2125 configuration have in average 30,000 different possible virtual 2126 addresses for each memory section. 2127 2128 If unsure, say Y. 2129 2130config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2131 hex "Physical memory mapping padding" if EXPERT 2132 depends on RANDOMIZE_MEMORY 2133 default "0xa" if MEMORY_HOTPLUG 2134 default "0x0" 2135 range 0x1 0x40 if MEMORY_HOTPLUG 2136 range 0x0 0x40 2137 ---help--- 2138 Define the padding in terabytes added to the existing physical 2139 memory size during kernel memory randomization. It is useful 2140 for memory hotplug support but reduces the entropy available for 2141 address randomization. 2142 2143 If unsure, leave at the default value. 2144 2145config HOTPLUG_CPU 2146 bool "Support for hot-pluggable CPUs" 2147 depends on SMP 2148 ---help--- 2149 Say Y here to allow turning CPUs off and on. CPUs can be 2150 controlled through /sys/devices/system/cpu. 2151 ( Note: power management support will enable this option 2152 automatically on SMP systems. ) 2153 Say N if you want to disable CPU hotplug. 2154 2155config BOOTPARAM_HOTPLUG_CPU0 2156 bool "Set default setting of cpu0_hotpluggable" 2157 default n 2158 depends on HOTPLUG_CPU 2159 ---help--- 2160 Set whether default state of cpu0_hotpluggable is on or off. 2161 2162 Say Y here to enable CPU0 hotplug by default. If this switch 2163 is turned on, there is no need to give cpu0_hotplug kernel 2164 parameter and the CPU0 hotplug feature is enabled by default. 2165 2166 Please note: there are two known CPU0 dependencies if you want 2167 to enable the CPU0 hotplug feature either by this switch or by 2168 cpu0_hotplug kernel parameter. 2169 2170 First, resume from hibernate or suspend always starts from CPU0. 2171 So hibernate and suspend are prevented if CPU0 is offline. 2172 2173 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2174 offline if any interrupt can not migrate out of CPU0. There may 2175 be other CPU0 dependencies. 2176 2177 Please make sure the dependencies are under your control before 2178 you enable this feature. 2179 2180 Say N if you don't want to enable CPU0 hotplug feature by default. 2181 You still can enable the CPU0 hotplug feature at boot by kernel 2182 parameter cpu0_hotplug. 2183 2184config DEBUG_HOTPLUG_CPU0 2185 def_bool n 2186 prompt "Debug CPU0 hotplug" 2187 depends on HOTPLUG_CPU 2188 ---help--- 2189 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2190 soon as possible and boots up userspace with CPU0 offlined. User 2191 can online CPU0 back after boot time. 2192 2193 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2194 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2195 compilation or giving cpu0_hotplug kernel parameter at boot. 2196 2197 If unsure, say N. 2198 2199config COMPAT_VDSO 2200 def_bool n 2201 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2202 depends on COMPAT_32 2203 ---help--- 2204 Certain buggy versions of glibc will crash if they are 2205 presented with a 32-bit vDSO that is not mapped at the address 2206 indicated in its segment table. 2207 2208 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2209 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2210 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2211 the only released version with the bug, but OpenSUSE 9 2212 contains a buggy "glibc 2.3.2". 2213 2214 The symptom of the bug is that everything crashes on startup, saying: 2215 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2216 2217 Saying Y here changes the default value of the vdso32 boot 2218 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2219 This works around the glibc bug but hurts performance. 2220 2221 If unsure, say N: if you are compiling your own kernel, you 2222 are unlikely to be using a buggy version of glibc. 2223 2224choice 2225 prompt "vsyscall table for legacy applications" 2226 depends on X86_64 2227 default LEGACY_VSYSCALL_EMULATE 2228 help 2229 Legacy user code that does not know how to find the vDSO expects 2230 to be able to issue three syscalls by calling fixed addresses in 2231 kernel space. Since this location is not randomized with ASLR, 2232 it can be used to assist security vulnerability exploitation. 2233 2234 This setting can be changed at boot time via the kernel command 2235 line parameter vsyscall=[native|emulate|none]. 2236 2237 On a system with recent enough glibc (2.14 or newer) and no 2238 static binaries, you can say None without a performance penalty 2239 to improve security. 2240 2241 If unsure, select "Emulate". 2242 2243 config LEGACY_VSYSCALL_NATIVE 2244 bool "Native" 2245 help 2246 Actual executable code is located in the fixed vsyscall 2247 address mapping, implementing time() efficiently. Since 2248 this makes the mapping executable, it can be used during 2249 security vulnerability exploitation (traditionally as 2250 ROP gadgets). This configuration is not recommended. 2251 2252 config LEGACY_VSYSCALL_EMULATE 2253 bool "Emulate" 2254 help 2255 The kernel traps and emulates calls into the fixed 2256 vsyscall address mapping. This makes the mapping 2257 non-executable, but it still contains known contents, 2258 which could be used in certain rare security vulnerability 2259 exploits. This configuration is recommended when userspace 2260 still uses the vsyscall area. 2261 2262 config LEGACY_VSYSCALL_NONE 2263 bool "None" 2264 help 2265 There will be no vsyscall mapping at all. This will 2266 eliminate any risk of ASLR bypass due to the vsyscall 2267 fixed address mapping. Attempts to use the vsyscalls 2268 will be reported to dmesg, so that either old or 2269 malicious userspace programs can be identified. 2270 2271endchoice 2272 2273config CMDLINE_BOOL 2274 bool "Built-in kernel command line" 2275 ---help--- 2276 Allow for specifying boot arguments to the kernel at 2277 build time. On some systems (e.g. embedded ones), it is 2278 necessary or convenient to provide some or all of the 2279 kernel boot arguments with the kernel itself (that is, 2280 to not rely on the boot loader to provide them.) 2281 2282 To compile command line arguments into the kernel, 2283 set this option to 'Y', then fill in the 2284 boot arguments in CONFIG_CMDLINE. 2285 2286 Systems with fully functional boot loaders (i.e. non-embedded) 2287 should leave this option set to 'N'. 2288 2289config CMDLINE 2290 string "Built-in kernel command string" 2291 depends on CMDLINE_BOOL 2292 default "" 2293 ---help--- 2294 Enter arguments here that should be compiled into the kernel 2295 image and used at boot time. If the boot loader provides a 2296 command line at boot time, it is appended to this string to 2297 form the full kernel command line, when the system boots. 2298 2299 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2300 change this behavior. 2301 2302 In most cases, the command line (whether built-in or provided 2303 by the boot loader) should specify the device for the root 2304 file system. 2305 2306config CMDLINE_OVERRIDE 2307 bool "Built-in command line overrides boot loader arguments" 2308 depends on CMDLINE_BOOL 2309 ---help--- 2310 Set this option to 'Y' to have the kernel ignore the boot loader 2311 command line, and use ONLY the built-in command line. 2312 2313 This is used to work around broken boot loaders. This should 2314 be set to 'N' under normal conditions. 2315 2316config MODIFY_LDT_SYSCALL 2317 bool "Enable the LDT (local descriptor table)" if EXPERT 2318 default y 2319 ---help--- 2320 Linux can allow user programs to install a per-process x86 2321 Local Descriptor Table (LDT) using the modify_ldt(2) system 2322 call. This is required to run 16-bit or segmented code such as 2323 DOSEMU or some Wine programs. It is also used by some very old 2324 threading libraries. 2325 2326 Enabling this feature adds a small amount of overhead to 2327 context switches and increases the low-level kernel attack 2328 surface. Disabling it removes the modify_ldt(2) system call. 2329 2330 Saying 'N' here may make sense for embedded or server kernels. 2331 2332source "kernel/livepatch/Kconfig" 2333 2334endmenu 2335 2336config ARCH_HAS_ADD_PAGES 2337 def_bool y 2338 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2339 2340config ARCH_ENABLE_MEMORY_HOTPLUG 2341 def_bool y 2342 depends on X86_64 || (X86_32 && HIGHMEM) 2343 2344config ARCH_ENABLE_MEMORY_HOTREMOVE 2345 def_bool y 2346 depends on MEMORY_HOTPLUG 2347 2348config USE_PERCPU_NUMA_NODE_ID 2349 def_bool y 2350 depends on NUMA 2351 2352config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2353 def_bool y 2354 depends on X86_64 || X86_PAE 2355 2356config ARCH_ENABLE_HUGEPAGE_MIGRATION 2357 def_bool y 2358 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2359 2360config ARCH_ENABLE_THP_MIGRATION 2361 def_bool y 2362 depends on X86_64 && TRANSPARENT_HUGEPAGE 2363 2364menu "Power management and ACPI options" 2365 2366config ARCH_HIBERNATION_HEADER 2367 def_bool y 2368 depends on X86_64 && HIBERNATION 2369 2370source "kernel/power/Kconfig" 2371 2372source "drivers/acpi/Kconfig" 2373 2374source "drivers/sfi/Kconfig" 2375 2376config X86_APM_BOOT 2377 def_bool y 2378 depends on APM 2379 2380menuconfig APM 2381 tristate "APM (Advanced Power Management) BIOS support" 2382 depends on X86_32 && PM_SLEEP 2383 ---help--- 2384 APM is a BIOS specification for saving power using several different 2385 techniques. This is mostly useful for battery powered laptops with 2386 APM compliant BIOSes. If you say Y here, the system time will be 2387 reset after a RESUME operation, the /proc/apm device will provide 2388 battery status information, and user-space programs will receive 2389 notification of APM "events" (e.g. battery status change). 2390 2391 If you select "Y" here, you can disable actual use of the APM 2392 BIOS by passing the "apm=off" option to the kernel at boot time. 2393 2394 Note that the APM support is almost completely disabled for 2395 machines with more than one CPU. 2396 2397 In order to use APM, you will need supporting software. For location 2398 and more information, read <file:Documentation/power/apm-acpi.txt> 2399 and the Battery Powered Linux mini-HOWTO, available from 2400 <http://www.tldp.org/docs.html#howto>. 2401 2402 This driver does not spin down disk drives (see the hdparm(8) 2403 manpage ("man 8 hdparm") for that), and it doesn't turn off 2404 VESA-compliant "green" monitors. 2405 2406 This driver does not support the TI 4000M TravelMate and the ACER 2407 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2408 desktop machines also don't have compliant BIOSes, and this driver 2409 may cause those machines to panic during the boot phase. 2410 2411 Generally, if you don't have a battery in your machine, there isn't 2412 much point in using this driver and you should say N. If you get 2413 random kernel OOPSes or reboots that don't seem to be related to 2414 anything, try disabling/enabling this option (or disabling/enabling 2415 APM in your BIOS). 2416 2417 Some other things you should try when experiencing seemingly random, 2418 "weird" problems: 2419 2420 1) make sure that you have enough swap space and that it is 2421 enabled. 2422 2) pass the "no-hlt" option to the kernel 2423 3) switch on floating point emulation in the kernel and pass 2424 the "no387" option to the kernel 2425 4) pass the "floppy=nodma" option to the kernel 2426 5) pass the "mem=4M" option to the kernel (thereby disabling 2427 all but the first 4 MB of RAM) 2428 6) make sure that the CPU is not over clocked. 2429 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2430 8) disable the cache from your BIOS settings 2431 9) install a fan for the video card or exchange video RAM 2432 10) install a better fan for the CPU 2433 11) exchange RAM chips 2434 12) exchange the motherboard. 2435 2436 To compile this driver as a module, choose M here: the 2437 module will be called apm. 2438 2439if APM 2440 2441config APM_IGNORE_USER_SUSPEND 2442 bool "Ignore USER SUSPEND" 2443 ---help--- 2444 This option will ignore USER SUSPEND requests. On machines with a 2445 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2446 series notebooks, it is necessary to say Y because of a BIOS bug. 2447 2448config APM_DO_ENABLE 2449 bool "Enable PM at boot time" 2450 ---help--- 2451 Enable APM features at boot time. From page 36 of the APM BIOS 2452 specification: "When disabled, the APM BIOS does not automatically 2453 power manage devices, enter the Standby State, enter the Suspend 2454 State, or take power saving steps in response to CPU Idle calls." 2455 This driver will make CPU Idle calls when Linux is idle (unless this 2456 feature is turned off -- see "Do CPU IDLE calls", below). This 2457 should always save battery power, but more complicated APM features 2458 will be dependent on your BIOS implementation. You may need to turn 2459 this option off if your computer hangs at boot time when using APM 2460 support, or if it beeps continuously instead of suspending. Turn 2461 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2462 T400CDT. This is off by default since most machines do fine without 2463 this feature. 2464 2465config APM_CPU_IDLE 2466 depends on CPU_IDLE 2467 bool "Make CPU Idle calls when idle" 2468 ---help--- 2469 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2470 On some machines, this can activate improved power savings, such as 2471 a slowed CPU clock rate, when the machine is idle. These idle calls 2472 are made after the idle loop has run for some length of time (e.g., 2473 333 mS). On some machines, this will cause a hang at boot time or 2474 whenever the CPU becomes idle. (On machines with more than one CPU, 2475 this option does nothing.) 2476 2477config APM_DISPLAY_BLANK 2478 bool "Enable console blanking using APM" 2479 ---help--- 2480 Enable console blanking using the APM. Some laptops can use this to 2481 turn off the LCD backlight when the screen blanker of the Linux 2482 virtual console blanks the screen. Note that this is only used by 2483 the virtual console screen blanker, and won't turn off the backlight 2484 when using the X Window system. This also doesn't have anything to 2485 do with your VESA-compliant power-saving monitor. Further, this 2486 option doesn't work for all laptops -- it might not turn off your 2487 backlight at all, or it might print a lot of errors to the console, 2488 especially if you are using gpm. 2489 2490config APM_ALLOW_INTS 2491 bool "Allow interrupts during APM BIOS calls" 2492 ---help--- 2493 Normally we disable external interrupts while we are making calls to 2494 the APM BIOS as a measure to lessen the effects of a badly behaving 2495 BIOS implementation. The BIOS should reenable interrupts if it 2496 needs to. Unfortunately, some BIOSes do not -- especially those in 2497 many of the newer IBM Thinkpads. If you experience hangs when you 2498 suspend, try setting this to Y. Otherwise, say N. 2499 2500endif # APM 2501 2502source "drivers/cpufreq/Kconfig" 2503 2504source "drivers/cpuidle/Kconfig" 2505 2506source "drivers/idle/Kconfig" 2507 2508endmenu 2509 2510 2511menu "Bus options (PCI etc.)" 2512 2513config PCI 2514 bool "PCI support" 2515 default y 2516 ---help--- 2517 Find out whether you have a PCI motherboard. PCI is the name of a 2518 bus system, i.e. the way the CPU talks to the other stuff inside 2519 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2520 VESA. If you have PCI, say Y, otherwise N. 2521 2522choice 2523 prompt "PCI access mode" 2524 depends on X86_32 && PCI 2525 default PCI_GOANY 2526 ---help--- 2527 On PCI systems, the BIOS can be used to detect the PCI devices and 2528 determine their configuration. However, some old PCI motherboards 2529 have BIOS bugs and may crash if this is done. Also, some embedded 2530 PCI-based systems don't have any BIOS at all. Linux can also try to 2531 detect the PCI hardware directly without using the BIOS. 2532 2533 With this option, you can specify how Linux should detect the 2534 PCI devices. If you choose "BIOS", the BIOS will be used, 2535 if you choose "Direct", the BIOS won't be used, and if you 2536 choose "MMConfig", then PCI Express MMCONFIG will be used. 2537 If you choose "Any", the kernel will try MMCONFIG, then the 2538 direct access method and falls back to the BIOS if that doesn't 2539 work. If unsure, go with the default, which is "Any". 2540 2541config PCI_GOBIOS 2542 bool "BIOS" 2543 2544config PCI_GOMMCONFIG 2545 bool "MMConfig" 2546 2547config PCI_GODIRECT 2548 bool "Direct" 2549 2550config PCI_GOOLPC 2551 bool "OLPC XO-1" 2552 depends on OLPC 2553 2554config PCI_GOANY 2555 bool "Any" 2556 2557endchoice 2558 2559config PCI_BIOS 2560 def_bool y 2561 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2562 2563# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2564config PCI_DIRECT 2565 def_bool y 2566 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2567 2568config PCI_MMCONFIG 2569 def_bool y 2570 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2571 2572config PCI_OLPC 2573 def_bool y 2574 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2575 2576config PCI_XEN 2577 def_bool y 2578 depends on PCI && XEN 2579 select SWIOTLB_XEN 2580 2581config PCI_DOMAINS 2582 def_bool y 2583 depends on PCI 2584 2585config PCI_MMCONFIG 2586 bool "Support mmconfig PCI config space access" 2587 depends on X86_64 && PCI && ACPI 2588 2589config PCI_CNB20LE_QUIRK 2590 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2591 depends on PCI 2592 help 2593 Read the PCI windows out of the CNB20LE host bridge. This allows 2594 PCI hotplug to work on systems with the CNB20LE chipset which do 2595 not have ACPI. 2596 2597 There's no public spec for this chipset, and this functionality 2598 is known to be incomplete. 2599 2600 You should say N unless you know you need this. 2601 2602source "drivers/pci/Kconfig" 2603 2604config ISA_BUS 2605 bool "ISA-style bus support on modern systems" if EXPERT 2606 select ISA_BUS_API 2607 help 2608 Enables ISA-style drivers on modern systems. This is necessary to 2609 support PC/104 devices on X86_64 platforms. 2610 2611 If unsure, say N. 2612 2613# x86_64 have no ISA slots, but can have ISA-style DMA. 2614config ISA_DMA_API 2615 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2616 default y 2617 help 2618 Enables ISA-style DMA support for devices requiring such controllers. 2619 If unsure, say Y. 2620 2621if X86_32 2622 2623config ISA 2624 bool "ISA support" 2625 ---help--- 2626 Find out whether you have ISA slots on your motherboard. ISA is the 2627 name of a bus system, i.e. the way the CPU talks to the other stuff 2628 inside your box. Other bus systems are PCI, EISA, MicroChannel 2629 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2630 newer boards don't support it. If you have ISA, say Y, otherwise N. 2631 2632config EISA 2633 bool "EISA support" 2634 depends on ISA 2635 ---help--- 2636 The Extended Industry Standard Architecture (EISA) bus was 2637 developed as an open alternative to the IBM MicroChannel bus. 2638 2639 The EISA bus provided some of the features of the IBM MicroChannel 2640 bus while maintaining backward compatibility with cards made for 2641 the older ISA bus. The EISA bus saw limited use between 1988 and 2642 1995 when it was made obsolete by the PCI bus. 2643 2644 Say Y here if you are building a kernel for an EISA-based machine. 2645 2646 Otherwise, say N. 2647 2648source "drivers/eisa/Kconfig" 2649 2650config SCx200 2651 tristate "NatSemi SCx200 support" 2652 ---help--- 2653 This provides basic support for National Semiconductor's 2654 (now AMD's) Geode processors. The driver probes for the 2655 PCI-IDs of several on-chip devices, so its a good dependency 2656 for other scx200_* drivers. 2657 2658 If compiled as a module, the driver is named scx200. 2659 2660config SCx200HR_TIMER 2661 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2662 depends on SCx200 2663 default y 2664 ---help--- 2665 This driver provides a clocksource built upon the on-chip 2666 27MHz high-resolution timer. Its also a workaround for 2667 NSC Geode SC-1100's buggy TSC, which loses time when the 2668 processor goes idle (as is done by the scheduler). The 2669 other workaround is idle=poll boot option. 2670 2671config OLPC 2672 bool "One Laptop Per Child support" 2673 depends on !X86_PAE 2674 select GPIOLIB 2675 select OF 2676 select OF_PROMTREE 2677 select IRQ_DOMAIN 2678 ---help--- 2679 Add support for detecting the unique features of the OLPC 2680 XO hardware. 2681 2682config OLPC_XO1_PM 2683 bool "OLPC XO-1 Power Management" 2684 depends on OLPC && MFD_CS5535 && PM_SLEEP 2685 select MFD_CORE 2686 ---help--- 2687 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2688 2689config OLPC_XO1_RTC 2690 bool "OLPC XO-1 Real Time Clock" 2691 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2692 ---help--- 2693 Add support for the XO-1 real time clock, which can be used as a 2694 programmable wakeup source. 2695 2696config OLPC_XO1_SCI 2697 bool "OLPC XO-1 SCI extras" 2698 depends on OLPC && OLPC_XO1_PM 2699 depends on INPUT=y 2700 select POWER_SUPPLY 2701 select GPIO_CS5535 2702 select MFD_CORE 2703 ---help--- 2704 Add support for SCI-based features of the OLPC XO-1 laptop: 2705 - EC-driven system wakeups 2706 - Power button 2707 - Ebook switch 2708 - Lid switch 2709 - AC adapter status updates 2710 - Battery status updates 2711 2712config OLPC_XO15_SCI 2713 bool "OLPC XO-1.5 SCI extras" 2714 depends on OLPC && ACPI 2715 select POWER_SUPPLY 2716 ---help--- 2717 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2718 - EC-driven system wakeups 2719 - AC adapter status updates 2720 - Battery status updates 2721 2722config ALIX 2723 bool "PCEngines ALIX System Support (LED setup)" 2724 select GPIOLIB 2725 ---help--- 2726 This option enables system support for the PCEngines ALIX. 2727 At present this just sets up LEDs for GPIO control on 2728 ALIX2/3/6 boards. However, other system specific setup should 2729 get added here. 2730 2731 Note: You must still enable the drivers for GPIO and LED support 2732 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2733 2734 Note: You have to set alix.force=1 for boards with Award BIOS. 2735 2736config NET5501 2737 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2738 select GPIOLIB 2739 ---help--- 2740 This option enables system support for the Soekris Engineering net5501. 2741 2742config GEOS 2743 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2744 select GPIOLIB 2745 depends on DMI 2746 ---help--- 2747 This option enables system support for the Traverse Technologies GEOS. 2748 2749config TS5500 2750 bool "Technologic Systems TS-5500 platform support" 2751 depends on MELAN 2752 select CHECK_SIGNATURE 2753 select NEW_LEDS 2754 select LEDS_CLASS 2755 ---help--- 2756 This option enables system support for the Technologic Systems TS-5500. 2757 2758endif # X86_32 2759 2760config AMD_NB 2761 def_bool y 2762 depends on CPU_SUP_AMD && PCI 2763 2764source "drivers/pcmcia/Kconfig" 2765 2766config RAPIDIO 2767 tristate "RapidIO support" 2768 depends on PCI 2769 default n 2770 help 2771 If enabled this option will include drivers and the core 2772 infrastructure code to support RapidIO interconnect devices. 2773 2774source "drivers/rapidio/Kconfig" 2775 2776config X86_SYSFB 2777 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2778 help 2779 Firmwares often provide initial graphics framebuffers so the BIOS, 2780 bootloader or kernel can show basic video-output during boot for 2781 user-guidance and debugging. Historically, x86 used the VESA BIOS 2782 Extensions and EFI-framebuffers for this, which are mostly limited 2783 to x86. 2784 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2785 framebuffers so the new generic system-framebuffer drivers can be 2786 used on x86. If the framebuffer is not compatible with the generic 2787 modes, it is adverticed as fallback platform framebuffer so legacy 2788 drivers like efifb, vesafb and uvesafb can pick it up. 2789 If this option is not selected, all system framebuffers are always 2790 marked as fallback platform framebuffers as usual. 2791 2792 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2793 not be able to pick up generic system framebuffers if this option 2794 is selected. You are highly encouraged to enable simplefb as 2795 replacement if you select this option. simplefb can correctly deal 2796 with generic system framebuffers. But you should still keep vesafb 2797 and others enabled as fallback if a system framebuffer is 2798 incompatible with simplefb. 2799 2800 If unsure, say Y. 2801 2802endmenu 2803 2804 2805menu "Executable file formats / Emulations" 2806 2807source "fs/Kconfig.binfmt" 2808 2809config IA32_EMULATION 2810 bool "IA32 Emulation" 2811 depends on X86_64 2812 select ARCH_WANT_OLD_COMPAT_IPC 2813 select BINFMT_ELF 2814 select COMPAT_BINFMT_ELF 2815 select COMPAT_OLD_SIGACTION 2816 ---help--- 2817 Include code to run legacy 32-bit programs under a 2818 64-bit kernel. You should likely turn this on, unless you're 2819 100% sure that you don't have any 32-bit programs left. 2820 2821config IA32_AOUT 2822 tristate "IA32 a.out support" 2823 depends on IA32_EMULATION 2824 ---help--- 2825 Support old a.out binaries in the 32bit emulation. 2826 2827config X86_X32 2828 bool "x32 ABI for 64-bit mode" 2829 depends on X86_64 2830 ---help--- 2831 Include code to run binaries for the x32 native 32-bit ABI 2832 for 64-bit processors. An x32 process gets access to the 2833 full 64-bit register file and wide data path while leaving 2834 pointers at 32 bits for smaller memory footprint. 2835 2836 You will need a recent binutils (2.22 or later) with 2837 elf32_x86_64 support enabled to compile a kernel with this 2838 option set. 2839 2840config COMPAT_32 2841 def_bool y 2842 depends on IA32_EMULATION || X86_32 2843 select HAVE_UID16 2844 select OLD_SIGSUSPEND3 2845 2846config COMPAT 2847 def_bool y 2848 depends on IA32_EMULATION || X86_X32 2849 2850if COMPAT 2851config COMPAT_FOR_U64_ALIGNMENT 2852 def_bool y 2853 2854config SYSVIPC_COMPAT 2855 def_bool y 2856 depends on SYSVIPC 2857endif 2858 2859endmenu 2860 2861 2862config HAVE_ATOMIC_IOMAP 2863 def_bool y 2864 depends on X86_32 2865 2866config X86_DEV_DMA_OPS 2867 bool 2868 depends on X86_64 || STA2X11 2869 2870config X86_DMA_REMAP 2871 bool 2872 depends on STA2X11 2873 2874config HAVE_GENERIC_GUP 2875 def_bool y 2876 2877source "net/Kconfig" 2878 2879source "drivers/Kconfig" 2880 2881source "drivers/firmware/Kconfig" 2882 2883source "fs/Kconfig" 2884 2885source "arch/x86/Kconfig.debug" 2886 2887source "security/Kconfig" 2888 2889source "crypto/Kconfig" 2890 2891source "arch/x86/kvm/Kconfig" 2892 2893source "lib/Kconfig" 2894