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