1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if ARCH = "x86" 5 default ARCH != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_AOUT 18 select HAVE_GENERIC_DMA_COHERENT 19 select MODULES_USE_ELF_REL 20 select OLD_SIGACTION 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select X86_DEV_DMA_OPS 32 33# 34# Arch settings 35# 36# ( Note that options that are marked 'if X86_64' could in principle be 37# ported to 32-bit as well. ) 38# 39config X86 40 def_bool y 41 # 42 # Note: keep this list sorted alphabetically 43 # 44 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 45 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 46 select ANON_INODES 47 select ARCH_CLOCKSOURCE_DATA 48 select ARCH_DISCARD_MEMBLOCK 49 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 50 select ARCH_HAS_DEBUG_VIRTUAL 51 select ARCH_HAS_DEVMEM_IS_ALLOWED 52 select ARCH_HAS_ELF_RANDOMIZE 53 select ARCH_HAS_FAST_MULTIPLIER 54 select ARCH_HAS_FORTIFY_SOURCE 55 select ARCH_HAS_GCOV_PROFILE_ALL 56 select ARCH_HAS_KCOV if X86_64 57 select ARCH_HAS_PMEM_API if X86_64 58 # Causing hangs/crashes, see the commit that added this change for details. 59 select ARCH_HAS_REFCOUNT 60 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 61 select ARCH_HAS_SET_MEMORY 62 select ARCH_HAS_SG_CHAIN 63 select ARCH_HAS_STRICT_KERNEL_RWX 64 select ARCH_HAS_STRICT_MODULE_RWX 65 select ARCH_HAS_UBSAN_SANITIZE_ALL 66 select ARCH_HAS_ZONE_DEVICE if X86_64 67 select ARCH_HAVE_NMI_SAFE_CMPXCHG 68 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 69 select ARCH_MIGHT_HAVE_PC_PARPORT 70 select ARCH_MIGHT_HAVE_PC_SERIO 71 select ARCH_SUPPORTS_ATOMIC_RMW 72 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 73 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 74 select ARCH_USE_BUILTIN_BSWAP 75 select ARCH_USE_QUEUED_RWLOCKS 76 select ARCH_USE_QUEUED_SPINLOCKS 77 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 78 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 79 select ARCH_WANTS_THP_SWAP if X86_64 80 select BUILDTIME_EXTABLE_SORT 81 select CLKEVT_I8253 82 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 83 select CLOCKSOURCE_WATCHDOG 84 select DCACHE_WORD_ACCESS 85 select EDAC_ATOMIC_SCRUB 86 select EDAC_SUPPORT 87 select GENERIC_CLOCKEVENTS 88 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 89 select GENERIC_CLOCKEVENTS_MIN_ADJUST 90 select GENERIC_CMOS_UPDATE 91 select GENERIC_CPU_AUTOPROBE 92 select GENERIC_EARLY_IOREMAP 93 select GENERIC_FIND_FIRST_BIT 94 select GENERIC_IOMAP 95 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 96 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 97 select GENERIC_IRQ_MIGRATION if SMP 98 select GENERIC_IRQ_PROBE 99 select GENERIC_IRQ_RESERVATION_MODE 100 select GENERIC_IRQ_SHOW 101 select GENERIC_PENDING_IRQ if SMP 102 select GENERIC_SMP_IDLE_THREAD 103 select GENERIC_STRNCPY_FROM_USER 104 select GENERIC_STRNLEN_USER 105 select GENERIC_TIME_VSYSCALL 106 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 107 select HAVE_ACPI_APEI if ACPI 108 select HAVE_ACPI_APEI_NMI if ACPI 109 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 110 select HAVE_ARCH_AUDITSYSCALL 111 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 112 select HAVE_ARCH_JUMP_LABEL 113 select HAVE_ARCH_KASAN if X86_64 114 select HAVE_ARCH_KGDB 115 select HAVE_ARCH_MMAP_RND_BITS if MMU 116 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 117 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 118 select HAVE_ARCH_SECCOMP_FILTER 119 select HAVE_ARCH_TRACEHOOK 120 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 121 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 122 select HAVE_ARCH_VMAP_STACK if X86_64 123 select HAVE_ARCH_WITHIN_STACK_FRAMES 124 select HAVE_CC_STACKPROTECTOR 125 select HAVE_CMPXCHG_DOUBLE 126 select HAVE_CMPXCHG_LOCAL 127 select HAVE_CONTEXT_TRACKING if X86_64 128 select HAVE_COPY_THREAD_TLS 129 select HAVE_C_RECORDMCOUNT 130 select HAVE_DEBUG_KMEMLEAK 131 select HAVE_DEBUG_STACKOVERFLOW 132 select HAVE_DMA_API_DEBUG 133 select HAVE_DMA_CONTIGUOUS 134 select HAVE_DYNAMIC_FTRACE 135 select HAVE_DYNAMIC_FTRACE_WITH_REGS 136 select HAVE_EBPF_JIT if X86_64 137 select HAVE_EFFICIENT_UNALIGNED_ACCESS 138 select HAVE_EXIT_THREAD 139 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 140 select HAVE_FTRACE_MCOUNT_RECORD 141 select HAVE_FUNCTION_GRAPH_TRACER 142 select HAVE_FUNCTION_TRACER 143 select HAVE_GCC_PLUGINS 144 select HAVE_HW_BREAKPOINT 145 select HAVE_IDE 146 select HAVE_IOREMAP_PROT 147 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 148 select HAVE_IRQ_TIME_ACCOUNTING 149 select HAVE_KERNEL_BZIP2 150 select HAVE_KERNEL_GZIP 151 select HAVE_KERNEL_LZ4 152 select HAVE_KERNEL_LZMA 153 select HAVE_KERNEL_LZO 154 select HAVE_KERNEL_XZ 155 select HAVE_KPROBES 156 select HAVE_KPROBES_ON_FTRACE 157 select HAVE_KPROBE_OVERRIDE 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 64 if SMP && X86_32 && X86_BIGSMP 931 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64 932 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 933 default "1" if !SMP 934 default "8192" if MAXSMP 935 default "32" if SMP && X86_BIGSMP 936 default "8" if SMP && X86_32 937 default "64" if SMP 938 ---help--- 939 This allows you to specify the maximum number of CPUs which this 940 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 941 supported value is 8192, otherwise the maximum value is 512. The 942 minimum value which makes sense is 2. 943 944 This is purely to save memory - each supported CPU adds 945 approximately eight kilobytes to the kernel image. 946 947config SCHED_SMT 948 bool "SMT (Hyperthreading) scheduler support" 949 depends on SMP 950 ---help--- 951 SMT scheduler support improves the CPU scheduler's decision making 952 when dealing with Intel Pentium 4 chips with HyperThreading at a 953 cost of slightly increased overhead in some places. If unsure say 954 N here. 955 956config SCHED_MC 957 def_bool y 958 prompt "Multi-core scheduler support" 959 depends on SMP 960 ---help--- 961 Multi-core scheduler support improves the CPU scheduler's decision 962 making when dealing with multi-core CPU chips at a cost of slightly 963 increased overhead in some places. If unsure say N here. 964 965config SCHED_MC_PRIO 966 bool "CPU core priorities scheduler support" 967 depends on SCHED_MC && CPU_SUP_INTEL 968 select X86_INTEL_PSTATE 969 select CPU_FREQ 970 default y 971 ---help--- 972 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 973 core ordering determined at manufacturing time, which allows 974 certain cores to reach higher turbo frequencies (when running 975 single threaded workloads) than others. 976 977 Enabling this kernel feature teaches the scheduler about 978 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 979 scheduler's CPU selection logic accordingly, so that higher 980 overall system performance can be achieved. 981 982 This feature will have no effect on CPUs without this feature. 983 984 If unsure say Y here. 985 986source "kernel/Kconfig.preempt" 987 988config UP_LATE_INIT 989 def_bool y 990 depends on !SMP && X86_LOCAL_APIC 991 992config X86_UP_APIC 993 bool "Local APIC support on uniprocessors" if !PCI_MSI 994 default PCI_MSI 995 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 996 ---help--- 997 A local APIC (Advanced Programmable Interrupt Controller) is an 998 integrated interrupt controller in the CPU. If you have a single-CPU 999 system which has a processor with a local APIC, you can say Y here to 1000 enable and use it. If you say Y here even though your machine doesn't 1001 have a local APIC, then the kernel will still run with no slowdown at 1002 all. The local APIC supports CPU-generated self-interrupts (timer, 1003 performance counters), and the NMI watchdog which detects hard 1004 lockups. 1005 1006config X86_UP_IOAPIC 1007 bool "IO-APIC support on uniprocessors" 1008 depends on X86_UP_APIC 1009 ---help--- 1010 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1011 SMP-capable replacement for PC-style interrupt controllers. Most 1012 SMP systems and many recent uniprocessor systems have one. 1013 1014 If you have a single-CPU system with an IO-APIC, you can say Y here 1015 to use it. If you say Y here even though your machine doesn't have 1016 an IO-APIC, then the kernel will still run with no slowdown at all. 1017 1018config X86_LOCAL_APIC 1019 def_bool y 1020 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1021 select IRQ_DOMAIN_HIERARCHY 1022 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1023 1024config X86_IO_APIC 1025 def_bool y 1026 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1027 1028config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1029 bool "Reroute for broken boot IRQs" 1030 depends on X86_IO_APIC 1031 ---help--- 1032 This option enables a workaround that fixes a source of 1033 spurious interrupts. This is recommended when threaded 1034 interrupt handling is used on systems where the generation of 1035 superfluous "boot interrupts" cannot be disabled. 1036 1037 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1038 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1039 kernel does during interrupt handling). On chipsets where this 1040 boot IRQ generation cannot be disabled, this workaround keeps 1041 the original IRQ line masked so that only the equivalent "boot 1042 IRQ" is delivered to the CPUs. The workaround also tells the 1043 kernel to set up the IRQ handler on the boot IRQ line. In this 1044 way only one interrupt is delivered to the kernel. Otherwise 1045 the spurious second interrupt may cause the kernel to bring 1046 down (vital) interrupt lines. 1047 1048 Only affects "broken" chipsets. Interrupt sharing may be 1049 increased on these systems. 1050 1051config X86_MCE 1052 bool "Machine Check / overheating reporting" 1053 select GENERIC_ALLOCATOR 1054 default y 1055 ---help--- 1056 Machine Check support allows the processor to notify the 1057 kernel if it detects a problem (e.g. overheating, data corruption). 1058 The action the kernel takes depends on the severity of the problem, 1059 ranging from warning messages to halting the machine. 1060 1061config X86_MCELOG_LEGACY 1062 bool "Support for deprecated /dev/mcelog character device" 1063 depends on X86_MCE 1064 ---help--- 1065 Enable support for /dev/mcelog which is needed by the old mcelog 1066 userspace logging daemon. Consider switching to the new generation 1067 rasdaemon solution. 1068 1069config X86_MCE_INTEL 1070 def_bool y 1071 prompt "Intel MCE features" 1072 depends on X86_MCE && X86_LOCAL_APIC 1073 ---help--- 1074 Additional support for intel specific MCE features such as 1075 the thermal monitor. 1076 1077config X86_MCE_AMD 1078 def_bool y 1079 prompt "AMD MCE features" 1080 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1081 ---help--- 1082 Additional support for AMD specific MCE features such as 1083 the DRAM Error Threshold. 1084 1085config X86_ANCIENT_MCE 1086 bool "Support for old Pentium 5 / WinChip machine checks" 1087 depends on X86_32 && X86_MCE 1088 ---help--- 1089 Include support for machine check handling on old Pentium 5 or WinChip 1090 systems. These typically need to be enabled explicitly on the command 1091 line. 1092 1093config X86_MCE_THRESHOLD 1094 depends on X86_MCE_AMD || X86_MCE_INTEL 1095 def_bool y 1096 1097config X86_MCE_INJECT 1098 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1099 tristate "Machine check injector support" 1100 ---help--- 1101 Provide support for injecting machine checks for testing purposes. 1102 If you don't know what a machine check is and you don't do kernel 1103 QA it is safe to say n. 1104 1105config X86_THERMAL_VECTOR 1106 def_bool y 1107 depends on X86_MCE_INTEL 1108 1109source "arch/x86/events/Kconfig" 1110 1111config X86_LEGACY_VM86 1112 bool "Legacy VM86 support" 1113 default n 1114 depends on X86_32 1115 ---help--- 1116 This option allows user programs to put the CPU into V8086 1117 mode, which is an 80286-era approximation of 16-bit real mode. 1118 1119 Some very old versions of X and/or vbetool require this option 1120 for user mode setting. Similarly, DOSEMU will use it if 1121 available to accelerate real mode DOS programs. However, any 1122 recent version of DOSEMU, X, or vbetool should be fully 1123 functional even without kernel VM86 support, as they will all 1124 fall back to software emulation. Nevertheless, if you are using 1125 a 16-bit DOS program where 16-bit performance matters, vm86 1126 mode might be faster than emulation and you might want to 1127 enable this option. 1128 1129 Note that any app that works on a 64-bit kernel is unlikely to 1130 need this option, as 64-bit kernels don't, and can't, support 1131 V8086 mode. This option is also unrelated to 16-bit protected 1132 mode and is not needed to run most 16-bit programs under Wine. 1133 1134 Enabling this option increases the complexity of the kernel 1135 and slows down exception handling a tiny bit. 1136 1137 If unsure, say N here. 1138 1139config VM86 1140 bool 1141 default X86_LEGACY_VM86 1142 1143config X86_16BIT 1144 bool "Enable support for 16-bit segments" if EXPERT 1145 default y 1146 depends on MODIFY_LDT_SYSCALL 1147 ---help--- 1148 This option is required by programs like Wine to run 16-bit 1149 protected mode legacy code on x86 processors. Disabling 1150 this option saves about 300 bytes on i386, or around 6K text 1151 plus 16K runtime memory on x86-64, 1152 1153config X86_ESPFIX32 1154 def_bool y 1155 depends on X86_16BIT && X86_32 1156 1157config X86_ESPFIX64 1158 def_bool y 1159 depends on X86_16BIT && X86_64 1160 1161config X86_VSYSCALL_EMULATION 1162 bool "Enable vsyscall emulation" if EXPERT 1163 default y 1164 depends on X86_64 1165 ---help--- 1166 This enables emulation of the legacy vsyscall page. Disabling 1167 it is roughly equivalent to booting with vsyscall=none, except 1168 that it will also disable the helpful warning if a program 1169 tries to use a vsyscall. With this option set to N, offending 1170 programs will just segfault, citing addresses of the form 1171 0xffffffffff600?00. 1172 1173 This option is required by many programs built before 2013, and 1174 care should be used even with newer programs if set to N. 1175 1176 Disabling this option saves about 7K of kernel size and 1177 possibly 4K of additional runtime pagetable memory. 1178 1179config TOSHIBA 1180 tristate "Toshiba Laptop support" 1181 depends on X86_32 1182 ---help--- 1183 This adds a driver to safely access the System Management Mode of 1184 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1185 not work on models with a Phoenix BIOS. The System Management Mode 1186 is used to set the BIOS and power saving options on Toshiba portables. 1187 1188 For information on utilities to make use of this driver see the 1189 Toshiba Linux utilities web site at: 1190 <http://www.buzzard.org.uk/toshiba/>. 1191 1192 Say Y if you intend to run this kernel on a Toshiba portable. 1193 Say N otherwise. 1194 1195config I8K 1196 tristate "Dell i8k legacy laptop support" 1197 select HWMON 1198 select SENSORS_DELL_SMM 1199 ---help--- 1200 This option enables legacy /proc/i8k userspace interface in hwmon 1201 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1202 temperature and allows controlling fan speeds of Dell laptops via 1203 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1204 it reports also power and hotkey status. For fan speed control is 1205 needed userspace package i8kutils. 1206 1207 Say Y if you intend to run this kernel on old Dell laptops or want to 1208 use userspace package i8kutils. 1209 Say N otherwise. 1210 1211config X86_REBOOTFIXUPS 1212 bool "Enable X86 board specific fixups for reboot" 1213 depends on X86_32 1214 ---help--- 1215 This enables chipset and/or board specific fixups to be done 1216 in order to get reboot to work correctly. This is only needed on 1217 some combinations of hardware and BIOS. The symptom, for which 1218 this config is intended, is when reboot ends with a stalled/hung 1219 system. 1220 1221 Currently, the only fixup is for the Geode machines using 1222 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1223 1224 Say Y if you want to enable the fixup. Currently, it's safe to 1225 enable this option even if you don't need it. 1226 Say N otherwise. 1227 1228config MICROCODE 1229 bool "CPU microcode loading support" 1230 default y 1231 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1232 select FW_LOADER 1233 ---help--- 1234 If you say Y here, you will be able to update the microcode on 1235 Intel and AMD processors. The Intel support is for the IA32 family, 1236 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1237 AMD support is for families 0x10 and later. You will obviously need 1238 the actual microcode binary data itself which is not shipped with 1239 the Linux kernel. 1240 1241 The preferred method to load microcode from a detached initrd is described 1242 in Documentation/x86/early-microcode.txt. For that you need to enable 1243 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1244 initrd for microcode blobs. 1245 1246 In addition, you can build-in the microcode into the kernel. For that you 1247 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1248 to the CONFIG_EXTRA_FIRMWARE config option. 1249 1250config MICROCODE_INTEL 1251 bool "Intel microcode loading support" 1252 depends on MICROCODE 1253 default MICROCODE 1254 select FW_LOADER 1255 ---help--- 1256 This options enables microcode patch loading support for Intel 1257 processors. 1258 1259 For the current Intel microcode data package go to 1260 <https://downloadcenter.intel.com> and search for 1261 'Linux Processor Microcode Data File'. 1262 1263config MICROCODE_AMD 1264 bool "AMD microcode loading support" 1265 depends on MICROCODE 1266 select FW_LOADER 1267 ---help--- 1268 If you select this option, microcode patch loading support for AMD 1269 processors will be enabled. 1270 1271config MICROCODE_OLD_INTERFACE 1272 def_bool y 1273 depends on MICROCODE 1274 1275config X86_MSR 1276 tristate "/dev/cpu/*/msr - Model-specific register support" 1277 ---help--- 1278 This device gives privileged processes access to the x86 1279 Model-Specific Registers (MSRs). It is a character device with 1280 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1281 MSR accesses are directed to a specific CPU on multi-processor 1282 systems. 1283 1284config X86_CPUID 1285 tristate "/dev/cpu/*/cpuid - CPU information support" 1286 ---help--- 1287 This device gives processes access to the x86 CPUID instruction to 1288 be executed on a specific processor. It is a character device 1289 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1290 /dev/cpu/31/cpuid. 1291 1292choice 1293 prompt "High Memory Support" 1294 default HIGHMEM4G 1295 depends on X86_32 1296 1297config NOHIGHMEM 1298 bool "off" 1299 ---help--- 1300 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1301 However, the address space of 32-bit x86 processors is only 4 1302 Gigabytes large. That means that, if you have a large amount of 1303 physical memory, not all of it can be "permanently mapped" by the 1304 kernel. The physical memory that's not permanently mapped is called 1305 "high memory". 1306 1307 If you are compiling a kernel which will never run on a machine with 1308 more than 1 Gigabyte total physical RAM, answer "off" here (default 1309 choice and suitable for most users). This will result in a "3GB/1GB" 1310 split: 3GB are mapped so that each process sees a 3GB virtual memory 1311 space and the remaining part of the 4GB virtual memory space is used 1312 by the kernel to permanently map as much physical memory as 1313 possible. 1314 1315 If the machine has between 1 and 4 Gigabytes physical RAM, then 1316 answer "4GB" here. 1317 1318 If more than 4 Gigabytes is used then answer "64GB" here. This 1319 selection turns Intel PAE (Physical Address Extension) mode on. 1320 PAE implements 3-level paging on IA32 processors. PAE is fully 1321 supported by Linux, PAE mode is implemented on all recent Intel 1322 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1323 then the kernel will not boot on CPUs that don't support PAE! 1324 1325 The actual amount of total physical memory will either be 1326 auto detected or can be forced by using a kernel command line option 1327 such as "mem=256M". (Try "man bootparam" or see the documentation of 1328 your boot loader (lilo or loadlin) about how to pass options to the 1329 kernel at boot time.) 1330 1331 If unsure, say "off". 1332 1333config HIGHMEM4G 1334 bool "4GB" 1335 ---help--- 1336 Select this if you have a 32-bit processor and between 1 and 4 1337 gigabytes of physical RAM. 1338 1339config HIGHMEM64G 1340 bool "64GB" 1341 depends on !M486 1342 select X86_PAE 1343 ---help--- 1344 Select this if you have a 32-bit processor and more than 4 1345 gigabytes of physical RAM. 1346 1347endchoice 1348 1349choice 1350 prompt "Memory split" if EXPERT 1351 default VMSPLIT_3G 1352 depends on X86_32 1353 ---help--- 1354 Select the desired split between kernel and user memory. 1355 1356 If the address range available to the kernel is less than the 1357 physical memory installed, the remaining memory will be available 1358 as "high memory". Accessing high memory is a little more costly 1359 than low memory, as it needs to be mapped into the kernel first. 1360 Note that increasing the kernel address space limits the range 1361 available to user programs, making the address space there 1362 tighter. Selecting anything other than the default 3G/1G split 1363 will also likely make your kernel incompatible with binary-only 1364 kernel modules. 1365 1366 If you are not absolutely sure what you are doing, leave this 1367 option alone! 1368 1369 config VMSPLIT_3G 1370 bool "3G/1G user/kernel split" 1371 config VMSPLIT_3G_OPT 1372 depends on !X86_PAE 1373 bool "3G/1G user/kernel split (for full 1G low memory)" 1374 config VMSPLIT_2G 1375 bool "2G/2G user/kernel split" 1376 config VMSPLIT_2G_OPT 1377 depends on !X86_PAE 1378 bool "2G/2G user/kernel split (for full 2G low memory)" 1379 config VMSPLIT_1G 1380 bool "1G/3G user/kernel split" 1381endchoice 1382 1383config PAGE_OFFSET 1384 hex 1385 default 0xB0000000 if VMSPLIT_3G_OPT 1386 default 0x80000000 if VMSPLIT_2G 1387 default 0x78000000 if VMSPLIT_2G_OPT 1388 default 0x40000000 if VMSPLIT_1G 1389 default 0xC0000000 1390 depends on X86_32 1391 1392config HIGHMEM 1393 def_bool y 1394 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1395 1396config X86_PAE 1397 bool "PAE (Physical Address Extension) Support" 1398 depends on X86_32 && !HIGHMEM4G 1399 select SWIOTLB 1400 ---help--- 1401 PAE is required for NX support, and furthermore enables 1402 larger swapspace support for non-overcommit purposes. It 1403 has the cost of more pagetable lookup overhead, and also 1404 consumes more pagetable space per process. 1405 1406config X86_5LEVEL 1407 bool "Enable 5-level page tables support" 1408 depends on X86_64 1409 ---help--- 1410 5-level paging enables access to larger address space: 1411 upto 128 PiB of virtual address space and 4 PiB of 1412 physical address space. 1413 1414 It will be supported by future Intel CPUs. 1415 1416 Note: a kernel with this option enabled can only be booted 1417 on machines that support the feature. 1418 1419 See Documentation/x86/x86_64/5level-paging.txt for more 1420 information. 1421 1422 Say N if unsure. 1423 1424config ARCH_PHYS_ADDR_T_64BIT 1425 def_bool y 1426 depends on X86_64 || X86_PAE 1427 1428config ARCH_DMA_ADDR_T_64BIT 1429 def_bool y 1430 depends on X86_64 || HIGHMEM64G 1431 1432config X86_DIRECT_GBPAGES 1433 def_bool y 1434 depends on X86_64 && !DEBUG_PAGEALLOC 1435 ---help--- 1436 Certain kernel features effectively disable kernel 1437 linear 1 GB mappings (even if the CPU otherwise 1438 supports them), so don't confuse the user by printing 1439 that we have them enabled. 1440 1441config ARCH_HAS_MEM_ENCRYPT 1442 def_bool y 1443 1444config AMD_MEM_ENCRYPT 1445 bool "AMD Secure Memory Encryption (SME) support" 1446 depends on X86_64 && CPU_SUP_AMD 1447 ---help--- 1448 Say yes to enable support for the encryption of system memory. 1449 This requires an AMD processor that supports Secure Memory 1450 Encryption (SME). 1451 1452config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1453 bool "Activate AMD Secure Memory Encryption (SME) by default" 1454 default y 1455 depends on AMD_MEM_ENCRYPT 1456 ---help--- 1457 Say yes to have system memory encrypted by default if running on 1458 an AMD processor that supports Secure Memory Encryption (SME). 1459 1460 If set to Y, then the encryption of system memory can be 1461 deactivated with the mem_encrypt=off command line option. 1462 1463 If set to N, then the encryption of system memory can be 1464 activated with the mem_encrypt=on command line option. 1465 1466config ARCH_USE_MEMREMAP_PROT 1467 def_bool y 1468 depends on AMD_MEM_ENCRYPT 1469 1470# Common NUMA Features 1471config NUMA 1472 bool "Numa Memory Allocation and Scheduler Support" 1473 depends on SMP 1474 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1475 default y if X86_BIGSMP 1476 ---help--- 1477 Enable NUMA (Non Uniform Memory Access) support. 1478 1479 The kernel will try to allocate memory used by a CPU on the 1480 local memory controller of the CPU and add some more 1481 NUMA awareness to the kernel. 1482 1483 For 64-bit this is recommended if the system is Intel Core i7 1484 (or later), AMD Opteron, or EM64T NUMA. 1485 1486 For 32-bit this is only needed if you boot a 32-bit 1487 kernel on a 64-bit NUMA platform. 1488 1489 Otherwise, you should say N. 1490 1491config AMD_NUMA 1492 def_bool y 1493 prompt "Old style AMD Opteron NUMA detection" 1494 depends on X86_64 && NUMA && PCI 1495 ---help--- 1496 Enable AMD NUMA node topology detection. You should say Y here if 1497 you have a multi processor AMD system. This uses an old method to 1498 read the NUMA configuration directly from the builtin Northbridge 1499 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1500 which also takes priority if both are compiled in. 1501 1502config X86_64_ACPI_NUMA 1503 def_bool y 1504 prompt "ACPI NUMA detection" 1505 depends on X86_64 && NUMA && ACPI && PCI 1506 select ACPI_NUMA 1507 ---help--- 1508 Enable ACPI SRAT based node topology detection. 1509 1510# Some NUMA nodes have memory ranges that span 1511# other nodes. Even though a pfn is valid and 1512# between a node's start and end pfns, it may not 1513# reside on that node. See memmap_init_zone() 1514# for details. 1515config NODES_SPAN_OTHER_NODES 1516 def_bool y 1517 depends on X86_64_ACPI_NUMA 1518 1519config NUMA_EMU 1520 bool "NUMA emulation" 1521 depends on NUMA 1522 ---help--- 1523 Enable NUMA emulation. A flat machine will be split 1524 into virtual nodes when booted with "numa=fake=N", where N is the 1525 number of nodes. This is only useful for debugging. 1526 1527config NODES_SHIFT 1528 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1529 range 1 10 1530 default "10" if MAXSMP 1531 default "6" if X86_64 1532 default "3" 1533 depends on NEED_MULTIPLE_NODES 1534 ---help--- 1535 Specify the maximum number of NUMA Nodes available on the target 1536 system. Increases memory reserved to accommodate various tables. 1537 1538config ARCH_HAVE_MEMORY_PRESENT 1539 def_bool y 1540 depends on X86_32 && DISCONTIGMEM 1541 1542config NEED_NODE_MEMMAP_SIZE 1543 def_bool y 1544 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1545 1546config ARCH_FLATMEM_ENABLE 1547 def_bool y 1548 depends on X86_32 && !NUMA 1549 1550config ARCH_DISCONTIGMEM_ENABLE 1551 def_bool y 1552 depends on NUMA && X86_32 1553 1554config ARCH_DISCONTIGMEM_DEFAULT 1555 def_bool y 1556 depends on NUMA && X86_32 1557 1558config ARCH_SPARSEMEM_ENABLE 1559 def_bool y 1560 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1561 select SPARSEMEM_STATIC if X86_32 1562 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1563 1564config ARCH_SPARSEMEM_DEFAULT 1565 def_bool y 1566 depends on X86_64 1567 1568config ARCH_SELECT_MEMORY_MODEL 1569 def_bool y 1570 depends on ARCH_SPARSEMEM_ENABLE 1571 1572config ARCH_MEMORY_PROBE 1573 bool "Enable sysfs memory/probe interface" 1574 depends on X86_64 && MEMORY_HOTPLUG 1575 help 1576 This option enables a sysfs memory/probe interface for testing. 1577 See Documentation/memory-hotplug.txt for more information. 1578 If you are unsure how to answer this question, answer N. 1579 1580config ARCH_PROC_KCORE_TEXT 1581 def_bool y 1582 depends on X86_64 && PROC_KCORE 1583 1584config ILLEGAL_POINTER_VALUE 1585 hex 1586 default 0 if X86_32 1587 default 0xdead000000000000 if X86_64 1588 1589source "mm/Kconfig" 1590 1591config X86_PMEM_LEGACY_DEVICE 1592 bool 1593 1594config X86_PMEM_LEGACY 1595 tristate "Support non-standard NVDIMMs and ADR protected memory" 1596 depends on PHYS_ADDR_T_64BIT 1597 depends on BLK_DEV 1598 select X86_PMEM_LEGACY_DEVICE 1599 select LIBNVDIMM 1600 help 1601 Treat memory marked using the non-standard e820 type of 12 as used 1602 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1603 The kernel will offer these regions to the 'pmem' driver so 1604 they can be used for persistent storage. 1605 1606 Say Y if unsure. 1607 1608config HIGHPTE 1609 bool "Allocate 3rd-level pagetables from highmem" 1610 depends on HIGHMEM 1611 ---help--- 1612 The VM uses one page table entry for each page of physical memory. 1613 For systems with a lot of RAM, this can be wasteful of precious 1614 low memory. Setting this option will put user-space page table 1615 entries in high memory. 1616 1617config X86_CHECK_BIOS_CORRUPTION 1618 bool "Check for low memory corruption" 1619 ---help--- 1620 Periodically check for memory corruption in low memory, which 1621 is suspected to be caused by BIOS. Even when enabled in the 1622 configuration, it is disabled at runtime. Enable it by 1623 setting "memory_corruption_check=1" on the kernel command 1624 line. By default it scans the low 64k of memory every 60 1625 seconds; see the memory_corruption_check_size and 1626 memory_corruption_check_period parameters in 1627 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1628 1629 When enabled with the default parameters, this option has 1630 almost no overhead, as it reserves a relatively small amount 1631 of memory and scans it infrequently. It both detects corruption 1632 and prevents it from affecting the running system. 1633 1634 It is, however, intended as a diagnostic tool; if repeatable 1635 BIOS-originated corruption always affects the same memory, 1636 you can use memmap= to prevent the kernel from using that 1637 memory. 1638 1639config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1640 bool "Set the default setting of memory_corruption_check" 1641 depends on X86_CHECK_BIOS_CORRUPTION 1642 default y 1643 ---help--- 1644 Set whether the default state of memory_corruption_check is 1645 on or off. 1646 1647config X86_RESERVE_LOW 1648 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1649 default 64 1650 range 4 640 1651 ---help--- 1652 Specify the amount of low memory to reserve for the BIOS. 1653 1654 The first page contains BIOS data structures that the kernel 1655 must not use, so that page must always be reserved. 1656 1657 By default we reserve the first 64K of physical RAM, as a 1658 number of BIOSes are known to corrupt that memory range 1659 during events such as suspend/resume or monitor cable 1660 insertion, so it must not be used by the kernel. 1661 1662 You can set this to 4 if you are absolutely sure that you 1663 trust the BIOS to get all its memory reservations and usages 1664 right. If you know your BIOS have problems beyond the 1665 default 64K area, you can set this to 640 to avoid using the 1666 entire low memory range. 1667 1668 If you have doubts about the BIOS (e.g. suspend/resume does 1669 not work or there's kernel crashes after certain hardware 1670 hotplug events) then you might want to enable 1671 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1672 typical corruption patterns. 1673 1674 Leave this to the default value of 64 if you are unsure. 1675 1676config MATH_EMULATION 1677 bool 1678 depends on MODIFY_LDT_SYSCALL 1679 prompt "Math emulation" if X86_32 1680 ---help--- 1681 Linux can emulate a math coprocessor (used for floating point 1682 operations) if you don't have one. 486DX and Pentium processors have 1683 a math coprocessor built in, 486SX and 386 do not, unless you added 1684 a 487DX or 387, respectively. (The messages during boot time can 1685 give you some hints here ["man dmesg"].) Everyone needs either a 1686 coprocessor or this emulation. 1687 1688 If you don't have a math coprocessor, you need to say Y here; if you 1689 say Y here even though you have a coprocessor, the coprocessor will 1690 be used nevertheless. (This behavior can be changed with the kernel 1691 command line option "no387", which comes handy if your coprocessor 1692 is broken. Try "man bootparam" or see the documentation of your boot 1693 loader (lilo or loadlin) about how to pass options to the kernel at 1694 boot time.) This means that it is a good idea to say Y here if you 1695 intend to use this kernel on different machines. 1696 1697 More information about the internals of the Linux math coprocessor 1698 emulation can be found in <file:arch/x86/math-emu/README>. 1699 1700 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1701 kernel, it won't hurt. 1702 1703config MTRR 1704 def_bool y 1705 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1706 ---help--- 1707 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1708 the Memory Type Range Registers (MTRRs) may be used to control 1709 processor access to memory ranges. This is most useful if you have 1710 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1711 allows bus write transfers to be combined into a larger transfer 1712 before bursting over the PCI/AGP bus. This can increase performance 1713 of image write operations 2.5 times or more. Saying Y here creates a 1714 /proc/mtrr file which may be used to manipulate your processor's 1715 MTRRs. Typically the X server should use this. 1716 1717 This code has a reasonably generic interface so that similar 1718 control registers on other processors can be easily supported 1719 as well: 1720 1721 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1722 Registers (ARRs) which provide a similar functionality to MTRRs. For 1723 these, the ARRs are used to emulate the MTRRs. 1724 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1725 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1726 write-combining. All of these processors are supported by this code 1727 and it makes sense to say Y here if you have one of them. 1728 1729 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1730 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1731 can lead to all sorts of problems, so it's good to say Y here. 1732 1733 You can safely say Y even if your machine doesn't have MTRRs, you'll 1734 just add about 9 KB to your kernel. 1735 1736 See <file:Documentation/x86/mtrr.txt> for more information. 1737 1738config MTRR_SANITIZER 1739 def_bool y 1740 prompt "MTRR cleanup support" 1741 depends on MTRR 1742 ---help--- 1743 Convert MTRR layout from continuous to discrete, so X drivers can 1744 add writeback entries. 1745 1746 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1747 The largest mtrr entry size for a continuous block can be set with 1748 mtrr_chunk_size. 1749 1750 If unsure, say Y. 1751 1752config MTRR_SANITIZER_ENABLE_DEFAULT 1753 int "MTRR cleanup enable value (0-1)" 1754 range 0 1 1755 default "0" 1756 depends on MTRR_SANITIZER 1757 ---help--- 1758 Enable mtrr cleanup default value 1759 1760config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1761 int "MTRR cleanup spare reg num (0-7)" 1762 range 0 7 1763 default "1" 1764 depends on MTRR_SANITIZER 1765 ---help--- 1766 mtrr cleanup spare entries default, it can be changed via 1767 mtrr_spare_reg_nr=N on the kernel command line. 1768 1769config X86_PAT 1770 def_bool y 1771 prompt "x86 PAT support" if EXPERT 1772 depends on MTRR 1773 ---help--- 1774 Use PAT attributes to setup page level cache control. 1775 1776 PATs are the modern equivalents of MTRRs and are much more 1777 flexible than MTRRs. 1778 1779 Say N here if you see bootup problems (boot crash, boot hang, 1780 spontaneous reboots) or a non-working video driver. 1781 1782 If unsure, say Y. 1783 1784config ARCH_USES_PG_UNCACHED 1785 def_bool y 1786 depends on X86_PAT 1787 1788config ARCH_RANDOM 1789 def_bool y 1790 prompt "x86 architectural random number generator" if EXPERT 1791 ---help--- 1792 Enable the x86 architectural RDRAND instruction 1793 (Intel Bull Mountain technology) to generate random numbers. 1794 If supported, this is a high bandwidth, cryptographically 1795 secure hardware random number generator. 1796 1797config X86_SMAP 1798 def_bool y 1799 prompt "Supervisor Mode Access Prevention" if EXPERT 1800 ---help--- 1801 Supervisor Mode Access Prevention (SMAP) is a security 1802 feature in newer Intel processors. There is a small 1803 performance cost if this enabled and turned on; there is 1804 also a small increase in the kernel size if this is enabled. 1805 1806 If unsure, say Y. 1807 1808config X86_INTEL_UMIP 1809 def_bool y 1810 depends on CPU_SUP_INTEL 1811 prompt "Intel User Mode Instruction Prevention" if EXPERT 1812 ---help--- 1813 The User Mode Instruction Prevention (UMIP) is a security 1814 feature in newer Intel processors. If enabled, a general 1815 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1816 or STR instructions are executed in user mode. These instructions 1817 unnecessarily expose information about the hardware state. 1818 1819 The vast majority of applications do not use these instructions. 1820 For the very few that do, software emulation is provided in 1821 specific cases in protected and virtual-8086 modes. Emulated 1822 results are dummy. 1823 1824config X86_INTEL_MPX 1825 prompt "Intel MPX (Memory Protection Extensions)" 1826 def_bool n 1827 # Note: only available in 64-bit mode due to VMA flags shortage 1828 depends on CPU_SUP_INTEL && X86_64 1829 select ARCH_USES_HIGH_VMA_FLAGS 1830 ---help--- 1831 MPX provides hardware features that can be used in 1832 conjunction with compiler-instrumented code to check 1833 memory references. It is designed to detect buffer 1834 overflow or underflow bugs. 1835 1836 This option enables running applications which are 1837 instrumented or otherwise use MPX. It does not use MPX 1838 itself inside the kernel or to protect the kernel 1839 against bad memory references. 1840 1841 Enabling this option will make the kernel larger: 1842 ~8k of kernel text and 36 bytes of data on a 64-bit 1843 defconfig. It adds a long to the 'mm_struct' which 1844 will increase the kernel memory overhead of each 1845 process and adds some branches to paths used during 1846 exec() and munmap(). 1847 1848 For details, see Documentation/x86/intel_mpx.txt 1849 1850 If unsure, say N. 1851 1852config X86_INTEL_MEMORY_PROTECTION_KEYS 1853 prompt "Intel Memory Protection Keys" 1854 def_bool y 1855 # Note: only available in 64-bit mode 1856 depends on CPU_SUP_INTEL && X86_64 1857 select ARCH_USES_HIGH_VMA_FLAGS 1858 select ARCH_HAS_PKEYS 1859 ---help--- 1860 Memory Protection Keys provides a mechanism for enforcing 1861 page-based protections, but without requiring modification of the 1862 page tables when an application changes protection domains. 1863 1864 For details, see Documentation/x86/protection-keys.txt 1865 1866 If unsure, say y. 1867 1868config EFI 1869 bool "EFI runtime service support" 1870 depends on ACPI 1871 select UCS2_STRING 1872 select EFI_RUNTIME_WRAPPERS 1873 ---help--- 1874 This enables the kernel to use EFI runtime services that are 1875 available (such as the EFI variable services). 1876 1877 This option is only useful on systems that have EFI firmware. 1878 In addition, you should use the latest ELILO loader available 1879 at <http://elilo.sourceforge.net> in order to take advantage 1880 of EFI runtime services. However, even with this option, the 1881 resultant kernel should continue to boot on existing non-EFI 1882 platforms. 1883 1884config EFI_STUB 1885 bool "EFI stub support" 1886 depends on EFI && !X86_USE_3DNOW 1887 select RELOCATABLE 1888 ---help--- 1889 This kernel feature allows a bzImage to be loaded directly 1890 by EFI firmware without the use of a bootloader. 1891 1892 See Documentation/efi-stub.txt for more information. 1893 1894config EFI_MIXED 1895 bool "EFI mixed-mode support" 1896 depends on EFI_STUB && X86_64 1897 ---help--- 1898 Enabling this feature allows a 64-bit kernel to be booted 1899 on a 32-bit firmware, provided that your CPU supports 64-bit 1900 mode. 1901 1902 Note that it is not possible to boot a mixed-mode enabled 1903 kernel via the EFI boot stub - a bootloader that supports 1904 the EFI handover protocol must be used. 1905 1906 If unsure, say N. 1907 1908config SECCOMP 1909 def_bool y 1910 prompt "Enable seccomp to safely compute untrusted bytecode" 1911 ---help--- 1912 This kernel feature is useful for number crunching applications 1913 that may need to compute untrusted bytecode during their 1914 execution. By using pipes or other transports made available to 1915 the process as file descriptors supporting the read/write 1916 syscalls, it's possible to isolate those applications in 1917 their own address space using seccomp. Once seccomp is 1918 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1919 and the task is only allowed to execute a few safe syscalls 1920 defined by each seccomp mode. 1921 1922 If unsure, say Y. Only embedded should say N here. 1923 1924source kernel/Kconfig.hz 1925 1926config KEXEC 1927 bool "kexec system call" 1928 select KEXEC_CORE 1929 ---help--- 1930 kexec is a system call that implements the ability to shutdown your 1931 current kernel, and to start another kernel. It is like a reboot 1932 but it is independent of the system firmware. And like a reboot 1933 you can start any kernel with it, not just Linux. 1934 1935 The name comes from the similarity to the exec system call. 1936 1937 It is an ongoing process to be certain the hardware in a machine 1938 is properly shutdown, so do not be surprised if this code does not 1939 initially work for you. As of this writing the exact hardware 1940 interface is strongly in flux, so no good recommendation can be 1941 made. 1942 1943config KEXEC_FILE 1944 bool "kexec file based system call" 1945 select KEXEC_CORE 1946 select BUILD_BIN2C 1947 depends on X86_64 1948 depends on CRYPTO=y 1949 depends on CRYPTO_SHA256=y 1950 ---help--- 1951 This is new version of kexec system call. This system call is 1952 file based and takes file descriptors as system call argument 1953 for kernel and initramfs as opposed to list of segments as 1954 accepted by previous system call. 1955 1956config KEXEC_VERIFY_SIG 1957 bool "Verify kernel signature during kexec_file_load() syscall" 1958 depends on KEXEC_FILE 1959 ---help--- 1960 This option makes kernel signature verification mandatory for 1961 the kexec_file_load() syscall. 1962 1963 In addition to that option, you need to enable signature 1964 verification for the corresponding kernel image type being 1965 loaded in order for this to work. 1966 1967config KEXEC_BZIMAGE_VERIFY_SIG 1968 bool "Enable bzImage signature verification support" 1969 depends on KEXEC_VERIFY_SIG 1970 depends on SIGNED_PE_FILE_VERIFICATION 1971 select SYSTEM_TRUSTED_KEYRING 1972 ---help--- 1973 Enable bzImage signature verification support. 1974 1975config CRASH_DUMP 1976 bool "kernel crash dumps" 1977 depends on X86_64 || (X86_32 && HIGHMEM) 1978 ---help--- 1979 Generate crash dump after being started by kexec. 1980 This should be normally only set in special crash dump kernels 1981 which are loaded in the main kernel with kexec-tools into 1982 a specially reserved region and then later executed after 1983 a crash by kdump/kexec. The crash dump kernel must be compiled 1984 to a memory address not used by the main kernel or BIOS using 1985 PHYSICAL_START, or it must be built as a relocatable image 1986 (CONFIG_RELOCATABLE=y). 1987 For more details see Documentation/kdump/kdump.txt 1988 1989config KEXEC_JUMP 1990 bool "kexec jump" 1991 depends on KEXEC && HIBERNATION 1992 ---help--- 1993 Jump between original kernel and kexeced kernel and invoke 1994 code in physical address mode via KEXEC 1995 1996config PHYSICAL_START 1997 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1998 default "0x1000000" 1999 ---help--- 2000 This gives the physical address where the kernel is loaded. 2001 2002 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2003 bzImage will decompress itself to above physical address and 2004 run from there. Otherwise, bzImage will run from the address where 2005 it has been loaded by the boot loader and will ignore above physical 2006 address. 2007 2008 In normal kdump cases one does not have to set/change this option 2009 as now bzImage can be compiled as a completely relocatable image 2010 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2011 address. This option is mainly useful for the folks who don't want 2012 to use a bzImage for capturing the crash dump and want to use a 2013 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2014 to be specifically compiled to run from a specific memory area 2015 (normally a reserved region) and this option comes handy. 2016 2017 So if you are using bzImage for capturing the crash dump, 2018 leave the value here unchanged to 0x1000000 and set 2019 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2020 for capturing the crash dump change this value to start of 2021 the reserved region. In other words, it can be set based on 2022 the "X" value as specified in the "crashkernel=YM@XM" 2023 command line boot parameter passed to the panic-ed 2024 kernel. Please take a look at Documentation/kdump/kdump.txt 2025 for more details about crash dumps. 2026 2027 Usage of bzImage for capturing the crash dump is recommended as 2028 one does not have to build two kernels. Same kernel can be used 2029 as production kernel and capture kernel. Above option should have 2030 gone away after relocatable bzImage support is introduced. But it 2031 is present because there are users out there who continue to use 2032 vmlinux for dump capture. This option should go away down the 2033 line. 2034 2035 Don't change this unless you know what you are doing. 2036 2037config RELOCATABLE 2038 bool "Build a relocatable kernel" 2039 default y 2040 ---help--- 2041 This builds a kernel image that retains relocation information 2042 so it can be loaded someplace besides the default 1MB. 2043 The relocations tend to make the kernel binary about 10% larger, 2044 but are discarded at runtime. 2045 2046 One use is for the kexec on panic case where the recovery kernel 2047 must live at a different physical address than the primary 2048 kernel. 2049 2050 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2051 it has been loaded at and the compile time physical address 2052 (CONFIG_PHYSICAL_START) is used as the minimum location. 2053 2054config RANDOMIZE_BASE 2055 bool "Randomize the address of the kernel image (KASLR)" 2056 depends on RELOCATABLE 2057 default y 2058 ---help--- 2059 In support of Kernel Address Space Layout Randomization (KASLR), 2060 this randomizes the physical address at which the kernel image 2061 is decompressed and the virtual address where the kernel 2062 image is mapped, as a security feature that deters exploit 2063 attempts relying on knowledge of the location of kernel 2064 code internals. 2065 2066 On 64-bit, the kernel physical and virtual addresses are 2067 randomized separately. The physical address will be anywhere 2068 between 16MB and the top of physical memory (up to 64TB). The 2069 virtual address will be randomized from 16MB up to 1GB (9 bits 2070 of entropy). Note that this also reduces the memory space 2071 available to kernel modules from 1.5GB to 1GB. 2072 2073 On 32-bit, the kernel physical and virtual addresses are 2074 randomized together. They will be randomized from 16MB up to 2075 512MB (8 bits of entropy). 2076 2077 Entropy is generated using the RDRAND instruction if it is 2078 supported. If RDTSC is supported, its value is mixed into 2079 the entropy pool as well. If neither RDRAND nor RDTSC are 2080 supported, then entropy is read from the i8254 timer. The 2081 usable entropy is limited by the kernel being built using 2082 2GB addressing, and that PHYSICAL_ALIGN must be at a 2083 minimum of 2MB. As a result, only 10 bits of entropy are 2084 theoretically possible, but the implementations are further 2085 limited due to memory layouts. 2086 2087 If unsure, say Y. 2088 2089# Relocation on x86 needs some additional build support 2090config X86_NEED_RELOCS 2091 def_bool y 2092 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2093 2094config PHYSICAL_ALIGN 2095 hex "Alignment value to which kernel should be aligned" 2096 default "0x200000" 2097 range 0x2000 0x1000000 if X86_32 2098 range 0x200000 0x1000000 if X86_64 2099 ---help--- 2100 This value puts the alignment restrictions on physical address 2101 where kernel is loaded and run from. Kernel is compiled for an 2102 address which meets above alignment restriction. 2103 2104 If bootloader loads the kernel at a non-aligned address and 2105 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2106 address aligned to above value and run from there. 2107 2108 If bootloader loads the kernel at a non-aligned address and 2109 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2110 load address and decompress itself to the address it has been 2111 compiled for and run from there. The address for which kernel is 2112 compiled already meets above alignment restrictions. Hence the 2113 end result is that kernel runs from a physical address meeting 2114 above alignment restrictions. 2115 2116 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2117 this value must be a multiple of 0x200000. 2118 2119 Don't change this unless you know what you are doing. 2120 2121config RANDOMIZE_MEMORY 2122 bool "Randomize the kernel memory sections" 2123 depends on X86_64 2124 depends on RANDOMIZE_BASE 2125 default RANDOMIZE_BASE 2126 ---help--- 2127 Randomizes the base virtual address of kernel memory sections 2128 (physical memory mapping, vmalloc & vmemmap). This security feature 2129 makes exploits relying on predictable memory locations less reliable. 2130 2131 The order of allocations remains unchanged. Entropy is generated in 2132 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2133 configuration have in average 30,000 different possible virtual 2134 addresses for each memory section. 2135 2136 If unsure, say Y. 2137 2138config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2139 hex "Physical memory mapping padding" if EXPERT 2140 depends on RANDOMIZE_MEMORY 2141 default "0xa" if MEMORY_HOTPLUG 2142 default "0x0" 2143 range 0x1 0x40 if MEMORY_HOTPLUG 2144 range 0x0 0x40 2145 ---help--- 2146 Define the padding in terabytes added to the existing physical 2147 memory size during kernel memory randomization. It is useful 2148 for memory hotplug support but reduces the entropy available for 2149 address randomization. 2150 2151 If unsure, leave at the default value. 2152 2153config HOTPLUG_CPU 2154 bool "Support for hot-pluggable CPUs" 2155 depends on SMP 2156 ---help--- 2157 Say Y here to allow turning CPUs off and on. CPUs can be 2158 controlled through /sys/devices/system/cpu. 2159 ( Note: power management support will enable this option 2160 automatically on SMP systems. ) 2161 Say N if you want to disable CPU hotplug. 2162 2163config BOOTPARAM_HOTPLUG_CPU0 2164 bool "Set default setting of cpu0_hotpluggable" 2165 default n 2166 depends on HOTPLUG_CPU 2167 ---help--- 2168 Set whether default state of cpu0_hotpluggable is on or off. 2169 2170 Say Y here to enable CPU0 hotplug by default. If this switch 2171 is turned on, there is no need to give cpu0_hotplug kernel 2172 parameter and the CPU0 hotplug feature is enabled by default. 2173 2174 Please note: there are two known CPU0 dependencies if you want 2175 to enable the CPU0 hotplug feature either by this switch or by 2176 cpu0_hotplug kernel parameter. 2177 2178 First, resume from hibernate or suspend always starts from CPU0. 2179 So hibernate and suspend are prevented if CPU0 is offline. 2180 2181 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2182 offline if any interrupt can not migrate out of CPU0. There may 2183 be other CPU0 dependencies. 2184 2185 Please make sure the dependencies are under your control before 2186 you enable this feature. 2187 2188 Say N if you don't want to enable CPU0 hotplug feature by default. 2189 You still can enable the CPU0 hotplug feature at boot by kernel 2190 parameter cpu0_hotplug. 2191 2192config DEBUG_HOTPLUG_CPU0 2193 def_bool n 2194 prompt "Debug CPU0 hotplug" 2195 depends on HOTPLUG_CPU 2196 ---help--- 2197 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2198 soon as possible and boots up userspace with CPU0 offlined. User 2199 can online CPU0 back after boot time. 2200 2201 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2202 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2203 compilation or giving cpu0_hotplug kernel parameter at boot. 2204 2205 If unsure, say N. 2206 2207config COMPAT_VDSO 2208 def_bool n 2209 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2210 depends on COMPAT_32 2211 ---help--- 2212 Certain buggy versions of glibc will crash if they are 2213 presented with a 32-bit vDSO that is not mapped at the address 2214 indicated in its segment table. 2215 2216 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2217 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2218 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2219 the only released version with the bug, but OpenSUSE 9 2220 contains a buggy "glibc 2.3.2". 2221 2222 The symptom of the bug is that everything crashes on startup, saying: 2223 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2224 2225 Saying Y here changes the default value of the vdso32 boot 2226 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2227 This works around the glibc bug but hurts performance. 2228 2229 If unsure, say N: if you are compiling your own kernel, you 2230 are unlikely to be using a buggy version of glibc. 2231 2232choice 2233 prompt "vsyscall table for legacy applications" 2234 depends on X86_64 2235 default LEGACY_VSYSCALL_EMULATE 2236 help 2237 Legacy user code that does not know how to find the vDSO expects 2238 to be able to issue three syscalls by calling fixed addresses in 2239 kernel space. Since this location is not randomized with ASLR, 2240 it can be used to assist security vulnerability exploitation. 2241 2242 This setting can be changed at boot time via the kernel command 2243 line parameter vsyscall=[native|emulate|none]. 2244 2245 On a system with recent enough glibc (2.14 or newer) and no 2246 static binaries, you can say None without a performance penalty 2247 to improve security. 2248 2249 If unsure, select "Emulate". 2250 2251 config LEGACY_VSYSCALL_NATIVE 2252 bool "Native" 2253 help 2254 Actual executable code is located in the fixed vsyscall 2255 address mapping, implementing time() efficiently. Since 2256 this makes the mapping executable, it can be used during 2257 security vulnerability exploitation (traditionally as 2258 ROP gadgets). This configuration is not recommended. 2259 2260 config LEGACY_VSYSCALL_EMULATE 2261 bool "Emulate" 2262 help 2263 The kernel traps and emulates calls into the fixed 2264 vsyscall address mapping. This makes the mapping 2265 non-executable, but it still contains known contents, 2266 which could be used in certain rare security vulnerability 2267 exploits. This configuration is recommended when userspace 2268 still uses the vsyscall area. 2269 2270 config LEGACY_VSYSCALL_NONE 2271 bool "None" 2272 help 2273 There will be no vsyscall mapping at all. This will 2274 eliminate any risk of ASLR bypass due to the vsyscall 2275 fixed address mapping. Attempts to use the vsyscalls 2276 will be reported to dmesg, so that either old or 2277 malicious userspace programs can be identified. 2278 2279endchoice 2280 2281config CMDLINE_BOOL 2282 bool "Built-in kernel command line" 2283 ---help--- 2284 Allow for specifying boot arguments to the kernel at 2285 build time. On some systems (e.g. embedded ones), it is 2286 necessary or convenient to provide some or all of the 2287 kernel boot arguments with the kernel itself (that is, 2288 to not rely on the boot loader to provide them.) 2289 2290 To compile command line arguments into the kernel, 2291 set this option to 'Y', then fill in the 2292 boot arguments in CONFIG_CMDLINE. 2293 2294 Systems with fully functional boot loaders (i.e. non-embedded) 2295 should leave this option set to 'N'. 2296 2297config CMDLINE 2298 string "Built-in kernel command string" 2299 depends on CMDLINE_BOOL 2300 default "" 2301 ---help--- 2302 Enter arguments here that should be compiled into the kernel 2303 image and used at boot time. If the boot loader provides a 2304 command line at boot time, it is appended to this string to 2305 form the full kernel command line, when the system boots. 2306 2307 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2308 change this behavior. 2309 2310 In most cases, the command line (whether built-in or provided 2311 by the boot loader) should specify the device for the root 2312 file system. 2313 2314config CMDLINE_OVERRIDE 2315 bool "Built-in command line overrides boot loader arguments" 2316 depends on CMDLINE_BOOL 2317 ---help--- 2318 Set this option to 'Y' to have the kernel ignore the boot loader 2319 command line, and use ONLY the built-in command line. 2320 2321 This is used to work around broken boot loaders. This should 2322 be set to 'N' under normal conditions. 2323 2324config MODIFY_LDT_SYSCALL 2325 bool "Enable the LDT (local descriptor table)" if EXPERT 2326 default y 2327 ---help--- 2328 Linux can allow user programs to install a per-process x86 2329 Local Descriptor Table (LDT) using the modify_ldt(2) system 2330 call. This is required to run 16-bit or segmented code such as 2331 DOSEMU or some Wine programs. It is also used by some very old 2332 threading libraries. 2333 2334 Enabling this feature adds a small amount of overhead to 2335 context switches and increases the low-level kernel attack 2336 surface. Disabling it removes the modify_ldt(2) system call. 2337 2338 Saying 'N' here may make sense for embedded or server kernels. 2339 2340source "kernel/livepatch/Kconfig" 2341 2342endmenu 2343 2344config ARCH_HAS_ADD_PAGES 2345 def_bool y 2346 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2347 2348config ARCH_ENABLE_MEMORY_HOTPLUG 2349 def_bool y 2350 depends on X86_64 || (X86_32 && HIGHMEM) 2351 2352config ARCH_ENABLE_MEMORY_HOTREMOVE 2353 def_bool y 2354 depends on MEMORY_HOTPLUG 2355 2356config USE_PERCPU_NUMA_NODE_ID 2357 def_bool y 2358 depends on NUMA 2359 2360config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2361 def_bool y 2362 depends on X86_64 || X86_PAE 2363 2364config ARCH_ENABLE_HUGEPAGE_MIGRATION 2365 def_bool y 2366 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2367 2368config ARCH_ENABLE_THP_MIGRATION 2369 def_bool y 2370 depends on X86_64 && TRANSPARENT_HUGEPAGE 2371 2372menu "Power management and ACPI options" 2373 2374config ARCH_HIBERNATION_HEADER 2375 def_bool y 2376 depends on X86_64 && HIBERNATION 2377 2378source "kernel/power/Kconfig" 2379 2380source "drivers/acpi/Kconfig" 2381 2382source "drivers/sfi/Kconfig" 2383 2384config X86_APM_BOOT 2385 def_bool y 2386 depends on APM 2387 2388menuconfig APM 2389 tristate "APM (Advanced Power Management) BIOS support" 2390 depends on X86_32 && PM_SLEEP 2391 ---help--- 2392 APM is a BIOS specification for saving power using several different 2393 techniques. This is mostly useful for battery powered laptops with 2394 APM compliant BIOSes. If you say Y here, the system time will be 2395 reset after a RESUME operation, the /proc/apm device will provide 2396 battery status information, and user-space programs will receive 2397 notification of APM "events" (e.g. battery status change). 2398 2399 If you select "Y" here, you can disable actual use of the APM 2400 BIOS by passing the "apm=off" option to the kernel at boot time. 2401 2402 Note that the APM support is almost completely disabled for 2403 machines with more than one CPU. 2404 2405 In order to use APM, you will need supporting software. For location 2406 and more information, read <file:Documentation/power/apm-acpi.txt> 2407 and the Battery Powered Linux mini-HOWTO, available from 2408 <http://www.tldp.org/docs.html#howto>. 2409 2410 This driver does not spin down disk drives (see the hdparm(8) 2411 manpage ("man 8 hdparm") for that), and it doesn't turn off 2412 VESA-compliant "green" monitors. 2413 2414 This driver does not support the TI 4000M TravelMate and the ACER 2415 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2416 desktop machines also don't have compliant BIOSes, and this driver 2417 may cause those machines to panic during the boot phase. 2418 2419 Generally, if you don't have a battery in your machine, there isn't 2420 much point in using this driver and you should say N. If you get 2421 random kernel OOPSes or reboots that don't seem to be related to 2422 anything, try disabling/enabling this option (or disabling/enabling 2423 APM in your BIOS). 2424 2425 Some other things you should try when experiencing seemingly random, 2426 "weird" problems: 2427 2428 1) make sure that you have enough swap space and that it is 2429 enabled. 2430 2) pass the "no-hlt" option to the kernel 2431 3) switch on floating point emulation in the kernel and pass 2432 the "no387" option to the kernel 2433 4) pass the "floppy=nodma" option to the kernel 2434 5) pass the "mem=4M" option to the kernel (thereby disabling 2435 all but the first 4 MB of RAM) 2436 6) make sure that the CPU is not over clocked. 2437 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2438 8) disable the cache from your BIOS settings 2439 9) install a fan for the video card or exchange video RAM 2440 10) install a better fan for the CPU 2441 11) exchange RAM chips 2442 12) exchange the motherboard. 2443 2444 To compile this driver as a module, choose M here: the 2445 module will be called apm. 2446 2447if APM 2448 2449config APM_IGNORE_USER_SUSPEND 2450 bool "Ignore USER SUSPEND" 2451 ---help--- 2452 This option will ignore USER SUSPEND requests. On machines with a 2453 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2454 series notebooks, it is necessary to say Y because of a BIOS bug. 2455 2456config APM_DO_ENABLE 2457 bool "Enable PM at boot time" 2458 ---help--- 2459 Enable APM features at boot time. From page 36 of the APM BIOS 2460 specification: "When disabled, the APM BIOS does not automatically 2461 power manage devices, enter the Standby State, enter the Suspend 2462 State, or take power saving steps in response to CPU Idle calls." 2463 This driver will make CPU Idle calls when Linux is idle (unless this 2464 feature is turned off -- see "Do CPU IDLE calls", below). This 2465 should always save battery power, but more complicated APM features 2466 will be dependent on your BIOS implementation. You may need to turn 2467 this option off if your computer hangs at boot time when using APM 2468 support, or if it beeps continuously instead of suspending. Turn 2469 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2470 T400CDT. This is off by default since most machines do fine without 2471 this feature. 2472 2473config APM_CPU_IDLE 2474 depends on CPU_IDLE 2475 bool "Make CPU Idle calls when idle" 2476 ---help--- 2477 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2478 On some machines, this can activate improved power savings, such as 2479 a slowed CPU clock rate, when the machine is idle. These idle calls 2480 are made after the idle loop has run for some length of time (e.g., 2481 333 mS). On some machines, this will cause a hang at boot time or 2482 whenever the CPU becomes idle. (On machines with more than one CPU, 2483 this option does nothing.) 2484 2485config APM_DISPLAY_BLANK 2486 bool "Enable console blanking using APM" 2487 ---help--- 2488 Enable console blanking using the APM. Some laptops can use this to 2489 turn off the LCD backlight when the screen blanker of the Linux 2490 virtual console blanks the screen. Note that this is only used by 2491 the virtual console screen blanker, and won't turn off the backlight 2492 when using the X Window system. This also doesn't have anything to 2493 do with your VESA-compliant power-saving monitor. Further, this 2494 option doesn't work for all laptops -- it might not turn off your 2495 backlight at all, or it might print a lot of errors to the console, 2496 especially if you are using gpm. 2497 2498config APM_ALLOW_INTS 2499 bool "Allow interrupts during APM BIOS calls" 2500 ---help--- 2501 Normally we disable external interrupts while we are making calls to 2502 the APM BIOS as a measure to lessen the effects of a badly behaving 2503 BIOS implementation. The BIOS should reenable interrupts if it 2504 needs to. Unfortunately, some BIOSes do not -- especially those in 2505 many of the newer IBM Thinkpads. If you experience hangs when you 2506 suspend, try setting this to Y. Otherwise, say N. 2507 2508endif # APM 2509 2510source "drivers/cpufreq/Kconfig" 2511 2512source "drivers/cpuidle/Kconfig" 2513 2514source "drivers/idle/Kconfig" 2515 2516endmenu 2517 2518 2519menu "Bus options (PCI etc.)" 2520 2521config PCI 2522 bool "PCI support" 2523 default y 2524 ---help--- 2525 Find out whether you have a PCI motherboard. PCI is the name of a 2526 bus system, i.e. the way the CPU talks to the other stuff inside 2527 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2528 VESA. If you have PCI, say Y, otherwise N. 2529 2530choice 2531 prompt "PCI access mode" 2532 depends on X86_32 && PCI 2533 default PCI_GOANY 2534 ---help--- 2535 On PCI systems, the BIOS can be used to detect the PCI devices and 2536 determine their configuration. However, some old PCI motherboards 2537 have BIOS bugs and may crash if this is done. Also, some embedded 2538 PCI-based systems don't have any BIOS at all. Linux can also try to 2539 detect the PCI hardware directly without using the BIOS. 2540 2541 With this option, you can specify how Linux should detect the 2542 PCI devices. If you choose "BIOS", the BIOS will be used, 2543 if you choose "Direct", the BIOS won't be used, and if you 2544 choose "MMConfig", then PCI Express MMCONFIG will be used. 2545 If you choose "Any", the kernel will try MMCONFIG, then the 2546 direct access method and falls back to the BIOS if that doesn't 2547 work. If unsure, go with the default, which is "Any". 2548 2549config PCI_GOBIOS 2550 bool "BIOS" 2551 2552config PCI_GOMMCONFIG 2553 bool "MMConfig" 2554 2555config PCI_GODIRECT 2556 bool "Direct" 2557 2558config PCI_GOOLPC 2559 bool "OLPC XO-1" 2560 depends on OLPC 2561 2562config PCI_GOANY 2563 bool "Any" 2564 2565endchoice 2566 2567config PCI_BIOS 2568 def_bool y 2569 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2570 2571# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2572config PCI_DIRECT 2573 def_bool y 2574 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2575 2576config PCI_MMCONFIG 2577 def_bool y 2578 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2579 2580config PCI_OLPC 2581 def_bool y 2582 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2583 2584config PCI_XEN 2585 def_bool y 2586 depends on PCI && XEN 2587 select SWIOTLB_XEN 2588 2589config PCI_DOMAINS 2590 def_bool y 2591 depends on PCI 2592 2593config PCI_MMCONFIG 2594 bool "Support mmconfig PCI config space access" 2595 depends on X86_64 && PCI && ACPI 2596 2597config PCI_CNB20LE_QUIRK 2598 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2599 depends on PCI 2600 help 2601 Read the PCI windows out of the CNB20LE host bridge. This allows 2602 PCI hotplug to work on systems with the CNB20LE chipset which do 2603 not have ACPI. 2604 2605 There's no public spec for this chipset, and this functionality 2606 is known to be incomplete. 2607 2608 You should say N unless you know you need this. 2609 2610source "drivers/pci/Kconfig" 2611 2612config ISA_BUS 2613 bool "ISA-style bus support on modern systems" if EXPERT 2614 select ISA_BUS_API 2615 help 2616 Enables ISA-style drivers on modern systems. This is necessary to 2617 support PC/104 devices on X86_64 platforms. 2618 2619 If unsure, say N. 2620 2621# x86_64 have no ISA slots, but can have ISA-style DMA. 2622config ISA_DMA_API 2623 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2624 default y 2625 help 2626 Enables ISA-style DMA support for devices requiring such controllers. 2627 If unsure, say Y. 2628 2629if X86_32 2630 2631config ISA 2632 bool "ISA support" 2633 ---help--- 2634 Find out whether you have ISA slots on your motherboard. ISA is the 2635 name of a bus system, i.e. the way the CPU talks to the other stuff 2636 inside your box. Other bus systems are PCI, EISA, MicroChannel 2637 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2638 newer boards don't support it. If you have ISA, say Y, otherwise N. 2639 2640config EISA 2641 bool "EISA support" 2642 depends on ISA 2643 ---help--- 2644 The Extended Industry Standard Architecture (EISA) bus was 2645 developed as an open alternative to the IBM MicroChannel bus. 2646 2647 The EISA bus provided some of the features of the IBM MicroChannel 2648 bus while maintaining backward compatibility with cards made for 2649 the older ISA bus. The EISA bus saw limited use between 1988 and 2650 1995 when it was made obsolete by the PCI bus. 2651 2652 Say Y here if you are building a kernel for an EISA-based machine. 2653 2654 Otherwise, say N. 2655 2656source "drivers/eisa/Kconfig" 2657 2658config SCx200 2659 tristate "NatSemi SCx200 support" 2660 ---help--- 2661 This provides basic support for National Semiconductor's 2662 (now AMD's) Geode processors. The driver probes for the 2663 PCI-IDs of several on-chip devices, so its a good dependency 2664 for other scx200_* drivers. 2665 2666 If compiled as a module, the driver is named scx200. 2667 2668config SCx200HR_TIMER 2669 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2670 depends on SCx200 2671 default y 2672 ---help--- 2673 This driver provides a clocksource built upon the on-chip 2674 27MHz high-resolution timer. Its also a workaround for 2675 NSC Geode SC-1100's buggy TSC, which loses time when the 2676 processor goes idle (as is done by the scheduler). The 2677 other workaround is idle=poll boot option. 2678 2679config OLPC 2680 bool "One Laptop Per Child support" 2681 depends on !X86_PAE 2682 select GPIOLIB 2683 select OF 2684 select OF_PROMTREE 2685 select IRQ_DOMAIN 2686 ---help--- 2687 Add support for detecting the unique features of the OLPC 2688 XO hardware. 2689 2690config OLPC_XO1_PM 2691 bool "OLPC XO-1 Power Management" 2692 depends on OLPC && MFD_CS5535 && PM_SLEEP 2693 select MFD_CORE 2694 ---help--- 2695 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2696 2697config OLPC_XO1_RTC 2698 bool "OLPC XO-1 Real Time Clock" 2699 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2700 ---help--- 2701 Add support for the XO-1 real time clock, which can be used as a 2702 programmable wakeup source. 2703 2704config OLPC_XO1_SCI 2705 bool "OLPC XO-1 SCI extras" 2706 depends on OLPC && OLPC_XO1_PM 2707 depends on INPUT=y 2708 select POWER_SUPPLY 2709 select GPIO_CS5535 2710 select MFD_CORE 2711 ---help--- 2712 Add support for SCI-based features of the OLPC XO-1 laptop: 2713 - EC-driven system wakeups 2714 - Power button 2715 - Ebook switch 2716 - Lid switch 2717 - AC adapter status updates 2718 - Battery status updates 2719 2720config OLPC_XO15_SCI 2721 bool "OLPC XO-1.5 SCI extras" 2722 depends on OLPC && ACPI 2723 select POWER_SUPPLY 2724 ---help--- 2725 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2726 - EC-driven system wakeups 2727 - AC adapter status updates 2728 - Battery status updates 2729 2730config ALIX 2731 bool "PCEngines ALIX System Support (LED setup)" 2732 select GPIOLIB 2733 ---help--- 2734 This option enables system support for the PCEngines ALIX. 2735 At present this just sets up LEDs for GPIO control on 2736 ALIX2/3/6 boards. However, other system specific setup should 2737 get added here. 2738 2739 Note: You must still enable the drivers for GPIO and LED support 2740 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2741 2742 Note: You have to set alix.force=1 for boards with Award BIOS. 2743 2744config NET5501 2745 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2746 select GPIOLIB 2747 ---help--- 2748 This option enables system support for the Soekris Engineering net5501. 2749 2750config GEOS 2751 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2752 select GPIOLIB 2753 depends on DMI 2754 ---help--- 2755 This option enables system support for the Traverse Technologies GEOS. 2756 2757config TS5500 2758 bool "Technologic Systems TS-5500 platform support" 2759 depends on MELAN 2760 select CHECK_SIGNATURE 2761 select NEW_LEDS 2762 select LEDS_CLASS 2763 ---help--- 2764 This option enables system support for the Technologic Systems TS-5500. 2765 2766endif # X86_32 2767 2768config AMD_NB 2769 def_bool y 2770 depends on CPU_SUP_AMD && PCI 2771 2772source "drivers/pcmcia/Kconfig" 2773 2774config RAPIDIO 2775 tristate "RapidIO support" 2776 depends on PCI 2777 default n 2778 help 2779 If enabled this option will include drivers and the core 2780 infrastructure code to support RapidIO interconnect devices. 2781 2782source "drivers/rapidio/Kconfig" 2783 2784config X86_SYSFB 2785 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2786 help 2787 Firmwares often provide initial graphics framebuffers so the BIOS, 2788 bootloader or kernel can show basic video-output during boot for 2789 user-guidance and debugging. Historically, x86 used the VESA BIOS 2790 Extensions and EFI-framebuffers for this, which are mostly limited 2791 to x86. 2792 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2793 framebuffers so the new generic system-framebuffer drivers can be 2794 used on x86. If the framebuffer is not compatible with the generic 2795 modes, it is adverticed as fallback platform framebuffer so legacy 2796 drivers like efifb, vesafb and uvesafb can pick it up. 2797 If this option is not selected, all system framebuffers are always 2798 marked as fallback platform framebuffers as usual. 2799 2800 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2801 not be able to pick up generic system framebuffers if this option 2802 is selected. You are highly encouraged to enable simplefb as 2803 replacement if you select this option. simplefb can correctly deal 2804 with generic system framebuffers. But you should still keep vesafb 2805 and others enabled as fallback if a system framebuffer is 2806 incompatible with simplefb. 2807 2808 If unsure, say Y. 2809 2810endmenu 2811 2812 2813menu "Executable file formats / Emulations" 2814 2815source "fs/Kconfig.binfmt" 2816 2817config IA32_EMULATION 2818 bool "IA32 Emulation" 2819 depends on X86_64 2820 select ARCH_WANT_OLD_COMPAT_IPC 2821 select BINFMT_ELF 2822 select COMPAT_BINFMT_ELF 2823 select COMPAT_OLD_SIGACTION 2824 ---help--- 2825 Include code to run legacy 32-bit programs under a 2826 64-bit kernel. You should likely turn this on, unless you're 2827 100% sure that you don't have any 32-bit programs left. 2828 2829config IA32_AOUT 2830 tristate "IA32 a.out support" 2831 depends on IA32_EMULATION 2832 ---help--- 2833 Support old a.out binaries in the 32bit emulation. 2834 2835config X86_X32 2836 bool "x32 ABI for 64-bit mode" 2837 depends on X86_64 2838 ---help--- 2839 Include code to run binaries for the x32 native 32-bit ABI 2840 for 64-bit processors. An x32 process gets access to the 2841 full 64-bit register file and wide data path while leaving 2842 pointers at 32 bits for smaller memory footprint. 2843 2844 You will need a recent binutils (2.22 or later) with 2845 elf32_x86_64 support enabled to compile a kernel with this 2846 option set. 2847 2848config COMPAT_32 2849 def_bool y 2850 depends on IA32_EMULATION || X86_32 2851 select HAVE_UID16 2852 select OLD_SIGSUSPEND3 2853 2854config COMPAT 2855 def_bool y 2856 depends on IA32_EMULATION || X86_X32 2857 2858if COMPAT 2859config COMPAT_FOR_U64_ALIGNMENT 2860 def_bool y 2861 2862config SYSVIPC_COMPAT 2863 def_bool y 2864 depends on SYSVIPC 2865endif 2866 2867endmenu 2868 2869 2870config HAVE_ATOMIC_IOMAP 2871 def_bool y 2872 depends on X86_32 2873 2874config X86_DEV_DMA_OPS 2875 bool 2876 depends on X86_64 || STA2X11 2877 2878config X86_DMA_REMAP 2879 bool 2880 depends on STA2X11 2881 2882config HAVE_GENERIC_GUP 2883 def_bool y 2884 2885source "net/Kconfig" 2886 2887source "drivers/Kconfig" 2888 2889source "drivers/firmware/Kconfig" 2890 2891source "fs/Kconfig" 2892 2893source "arch/x86/Kconfig.debug" 2894 2895source "security/Kconfig" 2896 2897source "crypto/Kconfig" 2898 2899source "arch/x86/kvm/Kconfig" 2900 2901source "lib/Kconfig" 2902