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_PHYS_TO_DMA 58 select ARCH_HAS_MEMBARRIER_SYNC_CORE 59 select ARCH_HAS_PMEM_API if X86_64 60 select ARCH_HAS_REFCOUNT 61 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 62 select ARCH_HAS_SET_MEMORY 63 select ARCH_HAS_SG_CHAIN 64 select ARCH_HAS_STRICT_KERNEL_RWX 65 select ARCH_HAS_STRICT_MODULE_RWX 66 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 67 select ARCH_HAS_UBSAN_SANITIZE_ALL 68 select ARCH_HAS_ZONE_DEVICE if X86_64 69 select ARCH_HAVE_NMI_SAFE_CMPXCHG 70 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 71 select ARCH_MIGHT_HAVE_PC_PARPORT 72 select ARCH_MIGHT_HAVE_PC_SERIO 73 select ARCH_SUPPORTS_ATOMIC_RMW 74 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 75 select ARCH_USE_BUILTIN_BSWAP 76 select ARCH_USE_QUEUED_RWLOCKS 77 select ARCH_USE_QUEUED_SPINLOCKS 78 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 79 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 80 select ARCH_WANTS_THP_SWAP if X86_64 81 select BUILDTIME_EXTABLE_SORT 82 select CLKEVT_I8253 83 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 84 select CLOCKSOURCE_WATCHDOG 85 select DCACHE_WORD_ACCESS 86 select EDAC_ATOMIC_SCRUB 87 select EDAC_SUPPORT 88 select GENERIC_CLOCKEVENTS 89 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 90 select GENERIC_CLOCKEVENTS_MIN_ADJUST 91 select GENERIC_CMOS_UPDATE 92 select GENERIC_CPU_AUTOPROBE 93 select GENERIC_CPU_VULNERABILITIES 94 select GENERIC_EARLY_IOREMAP 95 select GENERIC_FIND_FIRST_BIT 96 select GENERIC_IOMAP 97 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 98 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 99 select GENERIC_IRQ_MIGRATION if SMP 100 select GENERIC_IRQ_PROBE 101 select GENERIC_IRQ_RESERVATION_MODE 102 select GENERIC_IRQ_SHOW 103 select GENERIC_PENDING_IRQ if SMP 104 select GENERIC_SMP_IDLE_THREAD 105 select GENERIC_STRNCPY_FROM_USER 106 select GENERIC_STRNLEN_USER 107 select GENERIC_TIME_VSYSCALL 108 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 109 select HAVE_ACPI_APEI if ACPI 110 select HAVE_ACPI_APEI_NMI if ACPI 111 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 112 select HAVE_ARCH_AUDITSYSCALL 113 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 114 select HAVE_ARCH_JUMP_LABEL 115 select HAVE_ARCH_KASAN if X86_64 116 select HAVE_ARCH_KGDB 117 select HAVE_ARCH_MMAP_RND_BITS if MMU 118 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 119 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 120 select HAVE_ARCH_SECCOMP_FILTER 121 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 122 select HAVE_ARCH_TRACEHOOK 123 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 124 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 125 select HAVE_ARCH_VMAP_STACK if X86_64 126 select HAVE_ARCH_WITHIN_STACK_FRAMES 127 select HAVE_CC_STACKPROTECTOR 128 select HAVE_CMPXCHG_DOUBLE 129 select HAVE_CMPXCHG_LOCAL 130 select HAVE_CONTEXT_TRACKING if X86_64 131 select HAVE_COPY_THREAD_TLS 132 select HAVE_C_RECORDMCOUNT 133 select HAVE_DEBUG_KMEMLEAK 134 select HAVE_DEBUG_STACKOVERFLOW 135 select HAVE_DMA_API_DEBUG 136 select HAVE_DMA_CONTIGUOUS 137 select HAVE_DYNAMIC_FTRACE 138 select HAVE_DYNAMIC_FTRACE_WITH_REGS 139 select HAVE_EBPF_JIT if X86_64 140 select HAVE_EFFICIENT_UNALIGNED_ACCESS 141 select HAVE_EXIT_THREAD 142 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 143 select HAVE_FTRACE_MCOUNT_RECORD 144 select HAVE_FUNCTION_GRAPH_TRACER 145 select HAVE_FUNCTION_TRACER 146 select HAVE_GCC_PLUGINS 147 select HAVE_HW_BREAKPOINT 148 select HAVE_IDE 149 select HAVE_IOREMAP_PROT 150 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 151 select HAVE_IRQ_TIME_ACCOUNTING 152 select HAVE_KERNEL_BZIP2 153 select HAVE_KERNEL_GZIP 154 select HAVE_KERNEL_LZ4 155 select HAVE_KERNEL_LZMA 156 select HAVE_KERNEL_LZO 157 select HAVE_KERNEL_XZ 158 select HAVE_KPROBES 159 select HAVE_KPROBES_ON_FTRACE 160 select HAVE_FUNCTION_ERROR_INJECTION 161 select HAVE_KRETPROBES 162 select HAVE_KVM 163 select HAVE_LIVEPATCH if X86_64 164 select HAVE_MEMBLOCK 165 select HAVE_MEMBLOCK_NODE_MAP 166 select HAVE_MIXED_BREAKPOINTS_REGS 167 select HAVE_MOD_ARCH_SPECIFIC 168 select HAVE_NMI 169 select HAVE_OPROFILE 170 select HAVE_OPTPROBES 171 select HAVE_PCSPKR_PLATFORM 172 select HAVE_PERF_EVENTS 173 select HAVE_PERF_EVENTS_NMI 174 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 175 select HAVE_PERF_REGS 176 select HAVE_PERF_USER_STACK_DUMP 177 select HAVE_RCU_TABLE_FREE 178 select HAVE_REGS_AND_STACK_ACCESS_API 179 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 180 select HAVE_STACK_VALIDATION if X86_64 181 select HAVE_SYSCALL_TRACEPOINTS 182 select HAVE_UNSTABLE_SCHED_CLOCK 183 select HAVE_USER_RETURN_NOTIFIER 184 select IRQ_FORCED_THREADING 185 select PCI_LOCKLESS_CONFIG 186 select PERF_EVENTS 187 select RTC_LIB 188 select RTC_MC146818_LIB 189 select SPARSE_IRQ 190 select SRCU 191 select SYSCTL_EXCEPTION_TRACE 192 select THREAD_INFO_IN_TASK 193 select USER_STACKTRACE_SUPPORT 194 select VIRT_TO_BUS 195 select X86_FEATURE_NAMES if PROC_FS 196 197config INSTRUCTION_DECODER 198 def_bool y 199 depends on KPROBES || PERF_EVENTS || UPROBES 200 201config OUTPUT_FORMAT 202 string 203 default "elf32-i386" if X86_32 204 default "elf64-x86-64" if X86_64 205 206config ARCH_DEFCONFIG 207 string 208 default "arch/x86/configs/i386_defconfig" if X86_32 209 default "arch/x86/configs/x86_64_defconfig" if X86_64 210 211config LOCKDEP_SUPPORT 212 def_bool y 213 214config STACKTRACE_SUPPORT 215 def_bool y 216 217config MMU 218 def_bool y 219 220config ARCH_MMAP_RND_BITS_MIN 221 default 28 if 64BIT 222 default 8 223 224config ARCH_MMAP_RND_BITS_MAX 225 default 32 if 64BIT 226 default 16 227 228config ARCH_MMAP_RND_COMPAT_BITS_MIN 229 default 8 230 231config ARCH_MMAP_RND_COMPAT_BITS_MAX 232 default 16 233 234config SBUS 235 bool 236 237config NEED_DMA_MAP_STATE 238 def_bool y 239 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 240 241config NEED_SG_DMA_LENGTH 242 def_bool y 243 244config GENERIC_ISA_DMA 245 def_bool y 246 depends on ISA_DMA_API 247 248config GENERIC_BUG 249 def_bool y 250 depends on BUG 251 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 252 253config GENERIC_BUG_RELATIVE_POINTERS 254 bool 255 256config GENERIC_HWEIGHT 257 def_bool y 258 259config ARCH_MAY_HAVE_PC_FDC 260 def_bool y 261 depends on ISA_DMA_API 262 263config RWSEM_XCHGADD_ALGORITHM 264 def_bool y 265 266config GENERIC_CALIBRATE_DELAY 267 def_bool y 268 269config ARCH_HAS_CPU_RELAX 270 def_bool y 271 272config ARCH_HAS_CACHE_LINE_SIZE 273 def_bool y 274 275config HAVE_SETUP_PER_CPU_AREA 276 def_bool y 277 278config NEED_PER_CPU_EMBED_FIRST_CHUNK 279 def_bool y 280 281config NEED_PER_CPU_PAGE_FIRST_CHUNK 282 def_bool y 283 284config ARCH_HIBERNATION_POSSIBLE 285 def_bool y 286 287config ARCH_SUSPEND_POSSIBLE 288 def_bool y 289 290config ARCH_WANT_HUGE_PMD_SHARE 291 def_bool y 292 293config ARCH_WANT_GENERAL_HUGETLB 294 def_bool y 295 296config ZONE_DMA32 297 def_bool y if X86_64 298 299config AUDIT_ARCH 300 def_bool y if X86_64 301 302config ARCH_SUPPORTS_OPTIMIZED_INLINING 303 def_bool y 304 305config ARCH_SUPPORTS_DEBUG_PAGEALLOC 306 def_bool y 307 308config KASAN_SHADOW_OFFSET 309 hex 310 depends on KASAN 311 default 0xdffffc0000000000 312 313config HAVE_INTEL_TXT 314 def_bool y 315 depends on INTEL_IOMMU && ACPI 316 317config X86_32_SMP 318 def_bool y 319 depends on X86_32 && SMP 320 321config X86_64_SMP 322 def_bool y 323 depends on X86_64 && SMP 324 325config X86_32_LAZY_GS 326 def_bool y 327 depends on X86_32 && CC_STACKPROTECTOR_NONE 328 329config ARCH_SUPPORTS_UPROBES 330 def_bool y 331 332config FIX_EARLYCON_MEM 333 def_bool y 334 335config PGTABLE_LEVELS 336 int 337 default 5 if X86_5LEVEL 338 default 4 if X86_64 339 default 3 if X86_PAE 340 default 2 341 342source "init/Kconfig" 343source "kernel/Kconfig.freezer" 344 345menu "Processor type and features" 346 347config ZONE_DMA 348 bool "DMA memory allocation support" if EXPERT 349 default y 350 help 351 DMA memory allocation support allows devices with less than 32-bit 352 addressing to allocate within the first 16MB of address space. 353 Disable if no such devices will be used. 354 355 If unsure, say Y. 356 357config SMP 358 bool "Symmetric multi-processing support" 359 ---help--- 360 This enables support for systems with more than one CPU. If you have 361 a system with only one CPU, say N. If you have a system with more 362 than one CPU, say Y. 363 364 If you say N here, the kernel will run on uni- and multiprocessor 365 machines, but will use only one CPU of a multiprocessor machine. If 366 you say Y here, the kernel will run on many, but not all, 367 uniprocessor machines. On a uniprocessor machine, the kernel 368 will run faster if you say N here. 369 370 Note that if you say Y here and choose architecture "586" or 371 "Pentium" under "Processor family", the kernel will not work on 486 372 architectures. Similarly, multiprocessor kernels for the "PPro" 373 architecture may not work on all Pentium based boards. 374 375 People using multiprocessor machines who say Y here should also say 376 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 377 Management" code will be disabled if you say Y here. 378 379 See also <file:Documentation/x86/i386/IO-APIC.txt>, 380 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 381 <http://www.tldp.org/docs.html#howto>. 382 383 If you don't know what to do here, say N. 384 385config X86_FEATURE_NAMES 386 bool "Processor feature human-readable names" if EMBEDDED 387 default y 388 ---help--- 389 This option compiles in a table of x86 feature bits and corresponding 390 names. This is required to support /proc/cpuinfo and a few kernel 391 messages. You can disable this to save space, at the expense of 392 making those few kernel messages show numeric feature bits instead. 393 394 If in doubt, say Y. 395 396config X86_FAST_FEATURE_TESTS 397 bool "Fast CPU feature tests" if EMBEDDED 398 default y 399 ---help--- 400 Some fast-paths in the kernel depend on the capabilities of the CPU. 401 Say Y here for the kernel to patch in the appropriate code at runtime 402 based on the capabilities of the CPU. The infrastructure for patching 403 code at runtime takes up some additional space; space-constrained 404 embedded systems may wish to say N here to produce smaller, slightly 405 slower code. 406 407config X86_X2APIC 408 bool "Support x2apic" 409 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 410 ---help--- 411 This enables x2apic support on CPUs that have this feature. 412 413 This allows 32-bit apic IDs (so it can support very large systems), 414 and accesses the local apic via MSRs not via mmio. 415 416 If you don't know what to do here, say N. 417 418config X86_MPPARSE 419 bool "Enable MPS table" if ACPI || SFI 420 default y 421 depends on X86_LOCAL_APIC 422 ---help--- 423 For old smp systems that do not have proper acpi support. Newer systems 424 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 425 426config GOLDFISH 427 def_bool y 428 depends on X86_GOLDFISH 429 430config RETPOLINE 431 bool "Avoid speculative indirect branches in kernel" 432 default y 433 help 434 Compile kernel with the retpoline compiler options to guard against 435 kernel-to-user data leaks by avoiding speculative indirect 436 branches. Requires a compiler with -mindirect-branch=thunk-extern 437 support for full protection. The kernel may run slower. 438 439 Without compiler support, at least indirect branches in assembler 440 code are eliminated. Since this includes the syscall entry path, 441 it is not entirely pointless. 442 443config INTEL_RDT 444 bool "Intel Resource Director Technology support" 445 default n 446 depends on X86 && CPU_SUP_INTEL 447 select KERNFS 448 help 449 Select to enable resource allocation and monitoring which are 450 sub-features of Intel Resource Director Technology(RDT). More 451 information about RDT can be found in the Intel x86 452 Architecture Software Developer Manual. 453 454 Say N if unsure. 455 456if X86_32 457config X86_BIGSMP 458 bool "Support for big SMP systems with more than 8 CPUs" 459 depends on SMP 460 ---help--- 461 This option is needed for the systems that have more than 8 CPUs 462 463config X86_EXTENDED_PLATFORM 464 bool "Support for extended (non-PC) x86 platforms" 465 default y 466 ---help--- 467 If you disable this option then the kernel will only support 468 standard PC platforms. (which covers the vast majority of 469 systems out there.) 470 471 If you enable this option then you'll be able to select support 472 for the following (non-PC) 32 bit x86 platforms: 473 Goldfish (Android emulator) 474 AMD Elan 475 RDC R-321x SoC 476 SGI 320/540 (Visual Workstation) 477 STA2X11-based (e.g. Northville) 478 Moorestown MID devices 479 480 If you have one of these systems, or if you want to build a 481 generic distribution kernel, say Y here - otherwise say N. 482endif 483 484if X86_64 485config X86_EXTENDED_PLATFORM 486 bool "Support for extended (non-PC) x86 platforms" 487 default y 488 ---help--- 489 If you disable this option then the kernel will only support 490 standard PC platforms. (which covers the vast majority of 491 systems out there.) 492 493 If you enable this option then you'll be able to select support 494 for the following (non-PC) 64 bit x86 platforms: 495 Numascale NumaChip 496 ScaleMP vSMP 497 SGI Ultraviolet 498 499 If you have one of these systems, or if you want to build a 500 generic distribution kernel, say Y here - otherwise say N. 501endif 502# This is an alphabetically sorted list of 64 bit extended platforms 503# Please maintain the alphabetic order if and when there are additions 504config X86_NUMACHIP 505 bool "Numascale NumaChip" 506 depends on X86_64 507 depends on X86_EXTENDED_PLATFORM 508 depends on NUMA 509 depends on SMP 510 depends on X86_X2APIC 511 depends on PCI_MMCONFIG 512 ---help--- 513 Adds support for Numascale NumaChip large-SMP systems. Needed to 514 enable more than ~168 cores. 515 If you don't have one of these, you should say N here. 516 517config X86_VSMP 518 bool "ScaleMP vSMP" 519 select HYPERVISOR_GUEST 520 select PARAVIRT 521 depends on X86_64 && PCI 522 depends on X86_EXTENDED_PLATFORM 523 depends on SMP 524 ---help--- 525 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 526 supposed to run on these EM64T-based machines. Only choose this option 527 if you have one of these machines. 528 529config X86_UV 530 bool "SGI Ultraviolet" 531 depends on X86_64 532 depends on X86_EXTENDED_PLATFORM 533 depends on NUMA 534 depends on EFI 535 depends on X86_X2APIC 536 depends on PCI 537 ---help--- 538 This option is needed in order to support SGI Ultraviolet systems. 539 If you don't have one of these, you should say N here. 540 541# Following is an alphabetically sorted list of 32 bit extended platforms 542# Please maintain the alphabetic order if and when there are additions 543 544config X86_GOLDFISH 545 bool "Goldfish (Virtual Platform)" 546 depends on X86_EXTENDED_PLATFORM 547 ---help--- 548 Enable support for the Goldfish virtual platform used primarily 549 for Android development. Unless you are building for the Android 550 Goldfish emulator say N here. 551 552config X86_INTEL_CE 553 bool "CE4100 TV platform" 554 depends on PCI 555 depends on PCI_GODIRECT 556 depends on X86_IO_APIC 557 depends on X86_32 558 depends on X86_EXTENDED_PLATFORM 559 select X86_REBOOTFIXUPS 560 select OF 561 select OF_EARLY_FLATTREE 562 ---help--- 563 Select for the Intel CE media processor (CE4100) SOC. 564 This option compiles in support for the CE4100 SOC for settop 565 boxes and media devices. 566 567config X86_INTEL_MID 568 bool "Intel MID platform support" 569 depends on X86_EXTENDED_PLATFORM 570 depends on X86_PLATFORM_DEVICES 571 depends on PCI 572 depends on X86_64 || (PCI_GOANY && X86_32) 573 depends on X86_IO_APIC 574 select SFI 575 select I2C 576 select DW_APB_TIMER 577 select APB_TIMER 578 select INTEL_SCU_IPC 579 select MFD_INTEL_MSIC 580 ---help--- 581 Select to build a kernel capable of supporting Intel MID (Mobile 582 Internet Device) platform systems which do not have the PCI legacy 583 interfaces. If you are building for a PC class system say N here. 584 585 Intel MID platforms are based on an Intel processor and chipset which 586 consume less power than most of the x86 derivatives. 587 588config X86_INTEL_QUARK 589 bool "Intel Quark platform support" 590 depends on X86_32 591 depends on X86_EXTENDED_PLATFORM 592 depends on X86_PLATFORM_DEVICES 593 depends on X86_TSC 594 depends on PCI 595 depends on PCI_GOANY 596 depends on X86_IO_APIC 597 select IOSF_MBI 598 select INTEL_IMR 599 select COMMON_CLK 600 ---help--- 601 Select to include support for Quark X1000 SoC. 602 Say Y here if you have a Quark based system such as the Arduino 603 compatible Intel Galileo. 604 605config X86_INTEL_LPSS 606 bool "Intel Low Power Subsystem Support" 607 depends on X86 && ACPI 608 select COMMON_CLK 609 select PINCTRL 610 select IOSF_MBI 611 ---help--- 612 Select to build support for Intel Low Power Subsystem such as 613 found on Intel Lynxpoint PCH. Selecting this option enables 614 things like clock tree (common clock framework) and pincontrol 615 which are needed by the LPSS peripheral drivers. 616 617config X86_AMD_PLATFORM_DEVICE 618 bool "AMD ACPI2Platform devices support" 619 depends on ACPI 620 select COMMON_CLK 621 select PINCTRL 622 ---help--- 623 Select to interpret AMD specific ACPI device to platform device 624 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 625 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 626 implemented under PINCTRL subsystem. 627 628config IOSF_MBI 629 tristate "Intel SoC IOSF Sideband support for SoC platforms" 630 depends on PCI 631 ---help--- 632 This option enables sideband register access support for Intel SoC 633 platforms. On these platforms the IOSF sideband is used in lieu of 634 MSR's for some register accesses, mostly but not limited to thermal 635 and power. Drivers may query the availability of this device to 636 determine if they need the sideband in order to work on these 637 platforms. The sideband is available on the following SoC products. 638 This list is not meant to be exclusive. 639 - BayTrail 640 - Braswell 641 - Quark 642 643 You should say Y if you are running a kernel on one of these SoC's. 644 645config IOSF_MBI_DEBUG 646 bool "Enable IOSF sideband access through debugfs" 647 depends on IOSF_MBI && DEBUG_FS 648 ---help--- 649 Select this option to expose the IOSF sideband access registers (MCR, 650 MDR, MCRX) through debugfs to write and read register information from 651 different units on the SoC. This is most useful for obtaining device 652 state information for debug and analysis. As this is a general access 653 mechanism, users of this option would have specific knowledge of the 654 device they want to access. 655 656 If you don't require the option or are in doubt, say N. 657 658config X86_RDC321X 659 bool "RDC R-321x SoC" 660 depends on X86_32 661 depends on X86_EXTENDED_PLATFORM 662 select M486 663 select X86_REBOOTFIXUPS 664 ---help--- 665 This option is needed for RDC R-321x system-on-chip, also known 666 as R-8610-(G). 667 If you don't have one of these chips, you should say N here. 668 669config X86_32_NON_STANDARD 670 bool "Support non-standard 32-bit SMP architectures" 671 depends on X86_32 && SMP 672 depends on X86_EXTENDED_PLATFORM 673 ---help--- 674 This option compiles in the bigsmp and STA2X11 default 675 subarchitectures. It is intended for a generic binary 676 kernel. If you select them all, kernel will probe it one by 677 one and will fallback to default. 678 679# Alphabetically sorted list of Non standard 32 bit platforms 680 681config X86_SUPPORTS_MEMORY_FAILURE 682 def_bool y 683 # MCE code calls memory_failure(): 684 depends on X86_MCE 685 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 686 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 687 depends on X86_64 || !SPARSEMEM 688 select ARCH_SUPPORTS_MEMORY_FAILURE 689 690config STA2X11 691 bool "STA2X11 Companion Chip Support" 692 depends on X86_32_NON_STANDARD && PCI 693 select X86_DEV_DMA_OPS 694 select X86_DMA_REMAP 695 select SWIOTLB 696 select MFD_STA2X11 697 select GPIOLIB 698 default n 699 ---help--- 700 This adds support for boards based on the STA2X11 IO-Hub, 701 a.k.a. "ConneXt". The chip is used in place of the standard 702 PC chipset, so all "standard" peripherals are missing. If this 703 option is selected the kernel will still be able to boot on 704 standard PC machines. 705 706config X86_32_IRIS 707 tristate "Eurobraille/Iris poweroff module" 708 depends on X86_32 709 ---help--- 710 The Iris machines from EuroBraille do not have APM or ACPI support 711 to shut themselves down properly. A special I/O sequence is 712 needed to do so, which is what this module does at 713 kernel shutdown. 714 715 This is only for Iris machines from EuroBraille. 716 717 If unused, say N. 718 719config SCHED_OMIT_FRAME_POINTER 720 def_bool y 721 prompt "Single-depth WCHAN output" 722 depends on X86 723 ---help--- 724 Calculate simpler /proc/<PID>/wchan values. If this option 725 is disabled then wchan values will recurse back to the 726 caller function. This provides more accurate wchan values, 727 at the expense of slightly more scheduling overhead. 728 729 If in doubt, say "Y". 730 731menuconfig HYPERVISOR_GUEST 732 bool "Linux guest support" 733 ---help--- 734 Say Y here to enable options for running Linux under various hyper- 735 visors. This option enables basic hypervisor detection and platform 736 setup. 737 738 If you say N, all options in this submenu will be skipped and 739 disabled, and Linux guest support won't be built in. 740 741if HYPERVISOR_GUEST 742 743config PARAVIRT 744 bool "Enable paravirtualization code" 745 ---help--- 746 This changes the kernel so it can modify itself when it is run 747 under a hypervisor, potentially improving performance significantly 748 over full virtualization. However, when run without a hypervisor 749 the kernel is theoretically slower and slightly larger. 750 751config PARAVIRT_DEBUG 752 bool "paravirt-ops debugging" 753 depends on PARAVIRT && DEBUG_KERNEL 754 ---help--- 755 Enable to debug paravirt_ops internals. Specifically, BUG if 756 a paravirt_op is missing when it is called. 757 758config PARAVIRT_SPINLOCKS 759 bool "Paravirtualization layer for spinlocks" 760 depends on PARAVIRT && SMP 761 ---help--- 762 Paravirtualized spinlocks allow a pvops backend to replace the 763 spinlock implementation with something virtualization-friendly 764 (for example, block the virtual CPU rather than spinning). 765 766 It has a minimal impact on native kernels and gives a nice performance 767 benefit on paravirtualized KVM / Xen kernels. 768 769 If you are unsure how to answer this question, answer Y. 770 771config QUEUED_LOCK_STAT 772 bool "Paravirt queued spinlock statistics" 773 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 774 ---help--- 775 Enable the collection of statistical data on the slowpath 776 behavior of paravirtualized queued spinlocks and report 777 them on debugfs. 778 779source "arch/x86/xen/Kconfig" 780 781config KVM_GUEST 782 bool "KVM Guest support (including kvmclock)" 783 depends on PARAVIRT 784 select PARAVIRT_CLOCK 785 default y 786 ---help--- 787 This option enables various optimizations for running under the KVM 788 hypervisor. It includes a paravirtualized clock, so that instead 789 of relying on a PIT (or probably other) emulation by the 790 underlying device model, the host provides the guest with 791 timing infrastructure such as time of day, and system time 792 793config KVM_DEBUG_FS 794 bool "Enable debug information for KVM Guests in debugfs" 795 depends on KVM_GUEST && DEBUG_FS 796 default n 797 ---help--- 798 This option enables collection of various statistics for KVM guest. 799 Statistics are displayed in debugfs filesystem. Enabling this option 800 may incur significant overhead. 801 802config PARAVIRT_TIME_ACCOUNTING 803 bool "Paravirtual steal time accounting" 804 depends on PARAVIRT 805 default n 806 ---help--- 807 Select this option to enable fine granularity task steal time 808 accounting. Time spent executing other tasks in parallel with 809 the current vCPU is discounted from the vCPU power. To account for 810 that, there can be a small performance impact. 811 812 If in doubt, say N here. 813 814config PARAVIRT_CLOCK 815 bool 816 817config JAILHOUSE_GUEST 818 bool "Jailhouse non-root cell support" 819 depends on X86_64 && PCI 820 select X86_PM_TIMER 821 ---help--- 822 This option allows to run Linux as guest in a Jailhouse non-root 823 cell. You can leave this option disabled if you only want to start 824 Jailhouse and run Linux afterwards in the root cell. 825 826endif #HYPERVISOR_GUEST 827 828config NO_BOOTMEM 829 def_bool y 830 831source "arch/x86/Kconfig.cpu" 832 833config HPET_TIMER 834 def_bool X86_64 835 prompt "HPET Timer Support" if X86_32 836 ---help--- 837 Use the IA-PC HPET (High Precision Event Timer) to manage 838 time in preference to the PIT and RTC, if a HPET is 839 present. 840 HPET is the next generation timer replacing legacy 8254s. 841 The HPET provides a stable time base on SMP 842 systems, unlike the TSC, but it is more expensive to access, 843 as it is off-chip. The interface used is documented 844 in the HPET spec, revision 1. 845 846 You can safely choose Y here. However, HPET will only be 847 activated if the platform and the BIOS support this feature. 848 Otherwise the 8254 will be used for timing services. 849 850 Choose N to continue using the legacy 8254 timer. 851 852config HPET_EMULATE_RTC 853 def_bool y 854 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 855 856config APB_TIMER 857 def_bool y if X86_INTEL_MID 858 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 859 select DW_APB_TIMER 860 depends on X86_INTEL_MID && SFI 861 help 862 APB timer is the replacement for 8254, HPET on X86 MID platforms. 863 The APBT provides a stable time base on SMP 864 systems, unlike the TSC, but it is more expensive to access, 865 as it is off-chip. APB timers are always running regardless of CPU 866 C states, they are used as per CPU clockevent device when possible. 867 868# Mark as expert because too many people got it wrong. 869# The code disables itself when not needed. 870config DMI 871 default y 872 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 873 bool "Enable DMI scanning" if EXPERT 874 ---help--- 875 Enabled scanning of DMI to identify machine quirks. Say Y 876 here unless you have verified that your setup is not 877 affected by entries in the DMI blacklist. Required by PNP 878 BIOS code. 879 880config GART_IOMMU 881 bool "Old AMD GART IOMMU support" 882 select SWIOTLB 883 depends on X86_64 && PCI && AMD_NB 884 ---help--- 885 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 886 GART based hardware IOMMUs. 887 888 The GART supports full DMA access for devices with 32-bit access 889 limitations, on systems with more than 3 GB. This is usually needed 890 for USB, sound, many IDE/SATA chipsets and some other devices. 891 892 Newer systems typically have a modern AMD IOMMU, supported via 893 the CONFIG_AMD_IOMMU=y config option. 894 895 In normal configurations this driver is only active when needed: 896 there's more than 3 GB of memory and the system contains a 897 32-bit limited device. 898 899 If unsure, say Y. 900 901config CALGARY_IOMMU 902 bool "IBM Calgary IOMMU support" 903 select SWIOTLB 904 depends on X86_64 && PCI 905 ---help--- 906 Support for hardware IOMMUs in IBM's xSeries x366 and x460 907 systems. Needed to run systems with more than 3GB of memory 908 properly with 32-bit PCI devices that do not support DAC 909 (Double Address Cycle). Calgary also supports bus level 910 isolation, where all DMAs pass through the IOMMU. This 911 prevents them from going anywhere except their intended 912 destination. This catches hard-to-find kernel bugs and 913 mis-behaving drivers and devices that do not use the DMA-API 914 properly to set up their DMA buffers. The IOMMU can be 915 turned off at boot time with the iommu=off parameter. 916 Normally the kernel will make the right choice by itself. 917 If unsure, say Y. 918 919config CALGARY_IOMMU_ENABLED_BY_DEFAULT 920 def_bool y 921 prompt "Should Calgary be enabled by default?" 922 depends on CALGARY_IOMMU 923 ---help--- 924 Should Calgary be enabled by default? if you choose 'y', Calgary 925 will be used (if it exists). If you choose 'n', Calgary will not be 926 used even if it exists. If you choose 'n' and would like to use 927 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 928 If unsure, say Y. 929 930# need this always selected by IOMMU for the VIA workaround 931config SWIOTLB 932 def_bool y if X86_64 933 ---help--- 934 Support for software bounce buffers used on x86-64 systems 935 which don't have a hardware IOMMU. Using this PCI devices 936 which can only access 32-bits of memory can be used on systems 937 with more than 3 GB of memory. 938 If unsure, say Y. 939 940config IOMMU_HELPER 941 def_bool y 942 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 943 944config MAXSMP 945 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 946 depends on X86_64 && SMP && DEBUG_KERNEL 947 select CPUMASK_OFFSTACK 948 ---help--- 949 Enable maximum number of CPUS and NUMA Nodes for this architecture. 950 If unsure, say N. 951 952# 953# The maximum number of CPUs supported: 954# 955# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 956# and which can be configured interactively in the 957# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 958# 959# The ranges are different on 32-bit and 64-bit kernels, depending on 960# hardware capabilities and scalability features of the kernel. 961# 962# ( If MAXSMP is enabled we just use the highest possible value and disable 963# interactive configuration. ) 964# 965 966config NR_CPUS_RANGE_BEGIN 967 int 968 default NR_CPUS_RANGE_END if MAXSMP 969 default 1 if !SMP 970 default 2 971 972config NR_CPUS_RANGE_END 973 int 974 depends on X86_32 975 default 64 if SMP && X86_BIGSMP 976 default 8 if SMP && !X86_BIGSMP 977 default 1 if !SMP 978 979config NR_CPUS_RANGE_END 980 int 981 depends on X86_64 982 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 983 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 984 default 1 if !SMP 985 986config NR_CPUS_DEFAULT 987 int 988 depends on X86_32 989 default 32 if X86_BIGSMP 990 default 8 if SMP 991 default 1 if !SMP 992 993config NR_CPUS_DEFAULT 994 int 995 depends on X86_64 996 default 8192 if MAXSMP 997 default 64 if SMP 998 default 1 if !SMP 999 1000config NR_CPUS 1001 int "Maximum number of CPUs" if SMP && !MAXSMP 1002 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1003 default NR_CPUS_DEFAULT 1004 ---help--- 1005 This allows you to specify the maximum number of CPUs which this 1006 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1007 supported value is 8192, otherwise the maximum value is 512. The 1008 minimum value which makes sense is 2. 1009 1010 This is purely to save memory: each supported CPU adds about 8KB 1011 to the kernel image. 1012 1013config SCHED_SMT 1014 bool "SMT (Hyperthreading) scheduler support" 1015 depends on SMP 1016 ---help--- 1017 SMT scheduler support improves the CPU scheduler's decision making 1018 when dealing with Intel Pentium 4 chips with HyperThreading at a 1019 cost of slightly increased overhead in some places. If unsure say 1020 N here. 1021 1022config SCHED_MC 1023 def_bool y 1024 prompt "Multi-core scheduler support" 1025 depends on SMP 1026 ---help--- 1027 Multi-core scheduler support improves the CPU scheduler's decision 1028 making when dealing with multi-core CPU chips at a cost of slightly 1029 increased overhead in some places. If unsure say N here. 1030 1031config SCHED_MC_PRIO 1032 bool "CPU core priorities scheduler support" 1033 depends on SCHED_MC && CPU_SUP_INTEL 1034 select X86_INTEL_PSTATE 1035 select CPU_FREQ 1036 default y 1037 ---help--- 1038 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1039 core ordering determined at manufacturing time, which allows 1040 certain cores to reach higher turbo frequencies (when running 1041 single threaded workloads) than others. 1042 1043 Enabling this kernel feature teaches the scheduler about 1044 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1045 scheduler's CPU selection logic accordingly, so that higher 1046 overall system performance can be achieved. 1047 1048 This feature will have no effect on CPUs without this feature. 1049 1050 If unsure say Y here. 1051 1052source "kernel/Kconfig.preempt" 1053 1054config UP_LATE_INIT 1055 def_bool y 1056 depends on !SMP && X86_LOCAL_APIC 1057 1058config X86_UP_APIC 1059 bool "Local APIC support on uniprocessors" if !PCI_MSI 1060 default PCI_MSI 1061 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1062 ---help--- 1063 A local APIC (Advanced Programmable Interrupt Controller) is an 1064 integrated interrupt controller in the CPU. If you have a single-CPU 1065 system which has a processor with a local APIC, you can say Y here to 1066 enable and use it. If you say Y here even though your machine doesn't 1067 have a local APIC, then the kernel will still run with no slowdown at 1068 all. The local APIC supports CPU-generated self-interrupts (timer, 1069 performance counters), and the NMI watchdog which detects hard 1070 lockups. 1071 1072config X86_UP_IOAPIC 1073 bool "IO-APIC support on uniprocessors" 1074 depends on X86_UP_APIC 1075 ---help--- 1076 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1077 SMP-capable replacement for PC-style interrupt controllers. Most 1078 SMP systems and many recent uniprocessor systems have one. 1079 1080 If you have a single-CPU system with an IO-APIC, you can say Y here 1081 to use it. If you say Y here even though your machine doesn't have 1082 an IO-APIC, then the kernel will still run with no slowdown at all. 1083 1084config X86_LOCAL_APIC 1085 def_bool y 1086 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1087 select IRQ_DOMAIN_HIERARCHY 1088 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1089 1090config X86_IO_APIC 1091 def_bool y 1092 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1093 1094config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1095 bool "Reroute for broken boot IRQs" 1096 depends on X86_IO_APIC 1097 ---help--- 1098 This option enables a workaround that fixes a source of 1099 spurious interrupts. This is recommended when threaded 1100 interrupt handling is used on systems where the generation of 1101 superfluous "boot interrupts" cannot be disabled. 1102 1103 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1104 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1105 kernel does during interrupt handling). On chipsets where this 1106 boot IRQ generation cannot be disabled, this workaround keeps 1107 the original IRQ line masked so that only the equivalent "boot 1108 IRQ" is delivered to the CPUs. The workaround also tells the 1109 kernel to set up the IRQ handler on the boot IRQ line. In this 1110 way only one interrupt is delivered to the kernel. Otherwise 1111 the spurious second interrupt may cause the kernel to bring 1112 down (vital) interrupt lines. 1113 1114 Only affects "broken" chipsets. Interrupt sharing may be 1115 increased on these systems. 1116 1117config X86_MCE 1118 bool "Machine Check / overheating reporting" 1119 select GENERIC_ALLOCATOR 1120 default y 1121 ---help--- 1122 Machine Check support allows the processor to notify the 1123 kernel if it detects a problem (e.g. overheating, data corruption). 1124 The action the kernel takes depends on the severity of the problem, 1125 ranging from warning messages to halting the machine. 1126 1127config X86_MCELOG_LEGACY 1128 bool "Support for deprecated /dev/mcelog character device" 1129 depends on X86_MCE 1130 ---help--- 1131 Enable support for /dev/mcelog which is needed by the old mcelog 1132 userspace logging daemon. Consider switching to the new generation 1133 rasdaemon solution. 1134 1135config X86_MCE_INTEL 1136 def_bool y 1137 prompt "Intel MCE features" 1138 depends on X86_MCE && X86_LOCAL_APIC 1139 ---help--- 1140 Additional support for intel specific MCE features such as 1141 the thermal monitor. 1142 1143config X86_MCE_AMD 1144 def_bool y 1145 prompt "AMD MCE features" 1146 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1147 ---help--- 1148 Additional support for AMD specific MCE features such as 1149 the DRAM Error Threshold. 1150 1151config X86_ANCIENT_MCE 1152 bool "Support for old Pentium 5 / WinChip machine checks" 1153 depends on X86_32 && X86_MCE 1154 ---help--- 1155 Include support for machine check handling on old Pentium 5 or WinChip 1156 systems. These typically need to be enabled explicitly on the command 1157 line. 1158 1159config X86_MCE_THRESHOLD 1160 depends on X86_MCE_AMD || X86_MCE_INTEL 1161 def_bool y 1162 1163config X86_MCE_INJECT 1164 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1165 tristate "Machine check injector support" 1166 ---help--- 1167 Provide support for injecting machine checks for testing purposes. 1168 If you don't know what a machine check is and you don't do kernel 1169 QA it is safe to say n. 1170 1171config X86_THERMAL_VECTOR 1172 def_bool y 1173 depends on X86_MCE_INTEL 1174 1175source "arch/x86/events/Kconfig" 1176 1177config X86_LEGACY_VM86 1178 bool "Legacy VM86 support" 1179 default n 1180 depends on X86_32 1181 ---help--- 1182 This option allows user programs to put the CPU into V8086 1183 mode, which is an 80286-era approximation of 16-bit real mode. 1184 1185 Some very old versions of X and/or vbetool require this option 1186 for user mode setting. Similarly, DOSEMU will use it if 1187 available to accelerate real mode DOS programs. However, any 1188 recent version of DOSEMU, X, or vbetool should be fully 1189 functional even without kernel VM86 support, as they will all 1190 fall back to software emulation. Nevertheless, if you are using 1191 a 16-bit DOS program where 16-bit performance matters, vm86 1192 mode might be faster than emulation and you might want to 1193 enable this option. 1194 1195 Note that any app that works on a 64-bit kernel is unlikely to 1196 need this option, as 64-bit kernels don't, and can't, support 1197 V8086 mode. This option is also unrelated to 16-bit protected 1198 mode and is not needed to run most 16-bit programs under Wine. 1199 1200 Enabling this option increases the complexity of the kernel 1201 and slows down exception handling a tiny bit. 1202 1203 If unsure, say N here. 1204 1205config VM86 1206 bool 1207 default X86_LEGACY_VM86 1208 1209config X86_16BIT 1210 bool "Enable support for 16-bit segments" if EXPERT 1211 default y 1212 depends on MODIFY_LDT_SYSCALL 1213 ---help--- 1214 This option is required by programs like Wine to run 16-bit 1215 protected mode legacy code on x86 processors. Disabling 1216 this option saves about 300 bytes on i386, or around 6K text 1217 plus 16K runtime memory on x86-64, 1218 1219config X86_ESPFIX32 1220 def_bool y 1221 depends on X86_16BIT && X86_32 1222 1223config X86_ESPFIX64 1224 def_bool y 1225 depends on X86_16BIT && X86_64 1226 1227config X86_VSYSCALL_EMULATION 1228 bool "Enable vsyscall emulation" if EXPERT 1229 default y 1230 depends on X86_64 1231 ---help--- 1232 This enables emulation of the legacy vsyscall page. Disabling 1233 it is roughly equivalent to booting with vsyscall=none, except 1234 that it will also disable the helpful warning if a program 1235 tries to use a vsyscall. With this option set to N, offending 1236 programs will just segfault, citing addresses of the form 1237 0xffffffffff600?00. 1238 1239 This option is required by many programs built before 2013, and 1240 care should be used even with newer programs if set to N. 1241 1242 Disabling this option saves about 7K of kernel size and 1243 possibly 4K of additional runtime pagetable memory. 1244 1245config TOSHIBA 1246 tristate "Toshiba Laptop support" 1247 depends on X86_32 1248 ---help--- 1249 This adds a driver to safely access the System Management Mode of 1250 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1251 not work on models with a Phoenix BIOS. The System Management Mode 1252 is used to set the BIOS and power saving options on Toshiba portables. 1253 1254 For information on utilities to make use of this driver see the 1255 Toshiba Linux utilities web site at: 1256 <http://www.buzzard.org.uk/toshiba/>. 1257 1258 Say Y if you intend to run this kernel on a Toshiba portable. 1259 Say N otherwise. 1260 1261config I8K 1262 tristate "Dell i8k legacy laptop support" 1263 select HWMON 1264 select SENSORS_DELL_SMM 1265 ---help--- 1266 This option enables legacy /proc/i8k userspace interface in hwmon 1267 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1268 temperature and allows controlling fan speeds of Dell laptops via 1269 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1270 it reports also power and hotkey status. For fan speed control is 1271 needed userspace package i8kutils. 1272 1273 Say Y if you intend to run this kernel on old Dell laptops or want to 1274 use userspace package i8kutils. 1275 Say N otherwise. 1276 1277config X86_REBOOTFIXUPS 1278 bool "Enable X86 board specific fixups for reboot" 1279 depends on X86_32 1280 ---help--- 1281 This enables chipset and/or board specific fixups to be done 1282 in order to get reboot to work correctly. This is only needed on 1283 some combinations of hardware and BIOS. The symptom, for which 1284 this config is intended, is when reboot ends with a stalled/hung 1285 system. 1286 1287 Currently, the only fixup is for the Geode machines using 1288 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1289 1290 Say Y if you want to enable the fixup. Currently, it's safe to 1291 enable this option even if you don't need it. 1292 Say N otherwise. 1293 1294config MICROCODE 1295 bool "CPU microcode loading support" 1296 default y 1297 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1298 select FW_LOADER 1299 ---help--- 1300 If you say Y here, you will be able to update the microcode on 1301 Intel and AMD processors. The Intel support is for the IA32 family, 1302 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1303 AMD support is for families 0x10 and later. You will obviously need 1304 the actual microcode binary data itself which is not shipped with 1305 the Linux kernel. 1306 1307 The preferred method to load microcode from a detached initrd is described 1308 in Documentation/x86/early-microcode.txt. For that you need to enable 1309 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1310 initrd for microcode blobs. 1311 1312 In addition, you can build the microcode into the kernel. For that you 1313 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1314 config option. 1315 1316config MICROCODE_INTEL 1317 bool "Intel microcode loading support" 1318 depends on MICROCODE 1319 default MICROCODE 1320 select FW_LOADER 1321 ---help--- 1322 This options enables microcode patch loading support for Intel 1323 processors. 1324 1325 For the current Intel microcode data package go to 1326 <https://downloadcenter.intel.com> and search for 1327 'Linux Processor Microcode Data File'. 1328 1329config MICROCODE_AMD 1330 bool "AMD microcode loading support" 1331 depends on MICROCODE 1332 select FW_LOADER 1333 ---help--- 1334 If you select this option, microcode patch loading support for AMD 1335 processors will be enabled. 1336 1337config MICROCODE_OLD_INTERFACE 1338 def_bool y 1339 depends on MICROCODE 1340 1341config X86_MSR 1342 tristate "/dev/cpu/*/msr - Model-specific register support" 1343 ---help--- 1344 This device gives privileged processes access to the x86 1345 Model-Specific Registers (MSRs). It is a character device with 1346 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1347 MSR accesses are directed to a specific CPU on multi-processor 1348 systems. 1349 1350config X86_CPUID 1351 tristate "/dev/cpu/*/cpuid - CPU information support" 1352 ---help--- 1353 This device gives processes access to the x86 CPUID instruction to 1354 be executed on a specific processor. It is a character device 1355 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1356 /dev/cpu/31/cpuid. 1357 1358choice 1359 prompt "High Memory Support" 1360 default HIGHMEM4G 1361 depends on X86_32 1362 1363config NOHIGHMEM 1364 bool "off" 1365 ---help--- 1366 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1367 However, the address space of 32-bit x86 processors is only 4 1368 Gigabytes large. That means that, if you have a large amount of 1369 physical memory, not all of it can be "permanently mapped" by the 1370 kernel. The physical memory that's not permanently mapped is called 1371 "high memory". 1372 1373 If you are compiling a kernel which will never run on a machine with 1374 more than 1 Gigabyte total physical RAM, answer "off" here (default 1375 choice and suitable for most users). This will result in a "3GB/1GB" 1376 split: 3GB are mapped so that each process sees a 3GB virtual memory 1377 space and the remaining part of the 4GB virtual memory space is used 1378 by the kernel to permanently map as much physical memory as 1379 possible. 1380 1381 If the machine has between 1 and 4 Gigabytes physical RAM, then 1382 answer "4GB" here. 1383 1384 If more than 4 Gigabytes is used then answer "64GB" here. This 1385 selection turns Intel PAE (Physical Address Extension) mode on. 1386 PAE implements 3-level paging on IA32 processors. PAE is fully 1387 supported by Linux, PAE mode is implemented on all recent Intel 1388 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1389 then the kernel will not boot on CPUs that don't support PAE! 1390 1391 The actual amount of total physical memory will either be 1392 auto detected or can be forced by using a kernel command line option 1393 such as "mem=256M". (Try "man bootparam" or see the documentation of 1394 your boot loader (lilo or loadlin) about how to pass options to the 1395 kernel at boot time.) 1396 1397 If unsure, say "off". 1398 1399config HIGHMEM4G 1400 bool "4GB" 1401 ---help--- 1402 Select this if you have a 32-bit processor and between 1 and 4 1403 gigabytes of physical RAM. 1404 1405config HIGHMEM64G 1406 bool "64GB" 1407 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1408 select X86_PAE 1409 ---help--- 1410 Select this if you have a 32-bit processor and more than 4 1411 gigabytes of physical RAM. 1412 1413endchoice 1414 1415choice 1416 prompt "Memory split" if EXPERT 1417 default VMSPLIT_3G 1418 depends on X86_32 1419 ---help--- 1420 Select the desired split between kernel and user memory. 1421 1422 If the address range available to the kernel is less than the 1423 physical memory installed, the remaining memory will be available 1424 as "high memory". Accessing high memory is a little more costly 1425 than low memory, as it needs to be mapped into the kernel first. 1426 Note that increasing the kernel address space limits the range 1427 available to user programs, making the address space there 1428 tighter. Selecting anything other than the default 3G/1G split 1429 will also likely make your kernel incompatible with binary-only 1430 kernel modules. 1431 1432 If you are not absolutely sure what you are doing, leave this 1433 option alone! 1434 1435 config VMSPLIT_3G 1436 bool "3G/1G user/kernel split" 1437 config VMSPLIT_3G_OPT 1438 depends on !X86_PAE 1439 bool "3G/1G user/kernel split (for full 1G low memory)" 1440 config VMSPLIT_2G 1441 bool "2G/2G user/kernel split" 1442 config VMSPLIT_2G_OPT 1443 depends on !X86_PAE 1444 bool "2G/2G user/kernel split (for full 2G low memory)" 1445 config VMSPLIT_1G 1446 bool "1G/3G user/kernel split" 1447endchoice 1448 1449config PAGE_OFFSET 1450 hex 1451 default 0xB0000000 if VMSPLIT_3G_OPT 1452 default 0x80000000 if VMSPLIT_2G 1453 default 0x78000000 if VMSPLIT_2G_OPT 1454 default 0x40000000 if VMSPLIT_1G 1455 default 0xC0000000 1456 depends on X86_32 1457 1458config HIGHMEM 1459 def_bool y 1460 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1461 1462config X86_PAE 1463 bool "PAE (Physical Address Extension) Support" 1464 depends on X86_32 && !HIGHMEM4G 1465 select SWIOTLB 1466 ---help--- 1467 PAE is required for NX support, and furthermore enables 1468 larger swapspace support for non-overcommit purposes. It 1469 has the cost of more pagetable lookup overhead, and also 1470 consumes more pagetable space per process. 1471 1472config X86_5LEVEL 1473 bool "Enable 5-level page tables support" 1474 depends on X86_64 1475 ---help--- 1476 5-level paging enables access to larger address space: 1477 upto 128 PiB of virtual address space and 4 PiB of 1478 physical address space. 1479 1480 It will be supported by future Intel CPUs. 1481 1482 Note: a kernel with this option enabled can only be booted 1483 on machines that support the feature. 1484 1485 See Documentation/x86/x86_64/5level-paging.txt for more 1486 information. 1487 1488 Say N if unsure. 1489 1490config ARCH_PHYS_ADDR_T_64BIT 1491 def_bool y 1492 depends on X86_64 || X86_PAE 1493 1494config ARCH_DMA_ADDR_T_64BIT 1495 def_bool y 1496 depends on X86_64 || HIGHMEM64G 1497 1498config X86_DIRECT_GBPAGES 1499 def_bool y 1500 depends on X86_64 && !DEBUG_PAGEALLOC 1501 ---help--- 1502 Certain kernel features effectively disable kernel 1503 linear 1 GB mappings (even if the CPU otherwise 1504 supports them), so don't confuse the user by printing 1505 that we have them enabled. 1506 1507config ARCH_HAS_MEM_ENCRYPT 1508 def_bool y 1509 1510config AMD_MEM_ENCRYPT 1511 bool "AMD Secure Memory Encryption (SME) support" 1512 depends on X86_64 && CPU_SUP_AMD 1513 ---help--- 1514 Say yes to enable support for the encryption of system memory. 1515 This requires an AMD processor that supports Secure Memory 1516 Encryption (SME). 1517 1518config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1519 bool "Activate AMD Secure Memory Encryption (SME) by default" 1520 default y 1521 depends on AMD_MEM_ENCRYPT 1522 ---help--- 1523 Say yes to have system memory encrypted by default if running on 1524 an AMD processor that supports Secure Memory Encryption (SME). 1525 1526 If set to Y, then the encryption of system memory can be 1527 deactivated with the mem_encrypt=off command line option. 1528 1529 If set to N, then the encryption of system memory can be 1530 activated with the mem_encrypt=on command line option. 1531 1532config ARCH_USE_MEMREMAP_PROT 1533 def_bool y 1534 depends on AMD_MEM_ENCRYPT 1535 1536# Common NUMA Features 1537config NUMA 1538 bool "Numa Memory Allocation and Scheduler Support" 1539 depends on SMP 1540 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1541 default y if X86_BIGSMP 1542 ---help--- 1543 Enable NUMA (Non Uniform Memory Access) support. 1544 1545 The kernel will try to allocate memory used by a CPU on the 1546 local memory controller of the CPU and add some more 1547 NUMA awareness to the kernel. 1548 1549 For 64-bit this is recommended if the system is Intel Core i7 1550 (or later), AMD Opteron, or EM64T NUMA. 1551 1552 For 32-bit this is only needed if you boot a 32-bit 1553 kernel on a 64-bit NUMA platform. 1554 1555 Otherwise, you should say N. 1556 1557config AMD_NUMA 1558 def_bool y 1559 prompt "Old style AMD Opteron NUMA detection" 1560 depends on X86_64 && NUMA && PCI 1561 ---help--- 1562 Enable AMD NUMA node topology detection. You should say Y here if 1563 you have a multi processor AMD system. This uses an old method to 1564 read the NUMA configuration directly from the builtin Northbridge 1565 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1566 which also takes priority if both are compiled in. 1567 1568config X86_64_ACPI_NUMA 1569 def_bool y 1570 prompt "ACPI NUMA detection" 1571 depends on X86_64 && NUMA && ACPI && PCI 1572 select ACPI_NUMA 1573 ---help--- 1574 Enable ACPI SRAT based node topology detection. 1575 1576# Some NUMA nodes have memory ranges that span 1577# other nodes. Even though a pfn is valid and 1578# between a node's start and end pfns, it may not 1579# reside on that node. See memmap_init_zone() 1580# for details. 1581config NODES_SPAN_OTHER_NODES 1582 def_bool y 1583 depends on X86_64_ACPI_NUMA 1584 1585config NUMA_EMU 1586 bool "NUMA emulation" 1587 depends on NUMA 1588 ---help--- 1589 Enable NUMA emulation. A flat machine will be split 1590 into virtual nodes when booted with "numa=fake=N", where N is the 1591 number of nodes. This is only useful for debugging. 1592 1593config NODES_SHIFT 1594 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1595 range 1 10 1596 default "10" if MAXSMP 1597 default "6" if X86_64 1598 default "3" 1599 depends on NEED_MULTIPLE_NODES 1600 ---help--- 1601 Specify the maximum number of NUMA Nodes available on the target 1602 system. Increases memory reserved to accommodate various tables. 1603 1604config ARCH_HAVE_MEMORY_PRESENT 1605 def_bool y 1606 depends on X86_32 && DISCONTIGMEM 1607 1608config NEED_NODE_MEMMAP_SIZE 1609 def_bool y 1610 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1611 1612config ARCH_FLATMEM_ENABLE 1613 def_bool y 1614 depends on X86_32 && !NUMA 1615 1616config ARCH_DISCONTIGMEM_ENABLE 1617 def_bool y 1618 depends on NUMA && X86_32 1619 1620config ARCH_DISCONTIGMEM_DEFAULT 1621 def_bool y 1622 depends on NUMA && X86_32 1623 1624config ARCH_SPARSEMEM_ENABLE 1625 def_bool y 1626 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1627 select SPARSEMEM_STATIC if X86_32 1628 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1629 1630config ARCH_SPARSEMEM_DEFAULT 1631 def_bool y 1632 depends on X86_64 1633 1634config ARCH_SELECT_MEMORY_MODEL 1635 def_bool y 1636 depends on ARCH_SPARSEMEM_ENABLE 1637 1638config ARCH_MEMORY_PROBE 1639 bool "Enable sysfs memory/probe interface" 1640 depends on X86_64 && MEMORY_HOTPLUG 1641 help 1642 This option enables a sysfs memory/probe interface for testing. 1643 See Documentation/memory-hotplug.txt for more information. 1644 If you are unsure how to answer this question, answer N. 1645 1646config ARCH_PROC_KCORE_TEXT 1647 def_bool y 1648 depends on X86_64 && PROC_KCORE 1649 1650config ILLEGAL_POINTER_VALUE 1651 hex 1652 default 0 if X86_32 1653 default 0xdead000000000000 if X86_64 1654 1655source "mm/Kconfig" 1656 1657config X86_PMEM_LEGACY_DEVICE 1658 bool 1659 1660config X86_PMEM_LEGACY 1661 tristate "Support non-standard NVDIMMs and ADR protected memory" 1662 depends on PHYS_ADDR_T_64BIT 1663 depends on BLK_DEV 1664 select X86_PMEM_LEGACY_DEVICE 1665 select LIBNVDIMM 1666 help 1667 Treat memory marked using the non-standard e820 type of 12 as used 1668 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1669 The kernel will offer these regions to the 'pmem' driver so 1670 they can be used for persistent storage. 1671 1672 Say Y if unsure. 1673 1674config HIGHPTE 1675 bool "Allocate 3rd-level pagetables from highmem" 1676 depends on HIGHMEM 1677 ---help--- 1678 The VM uses one page table entry for each page of physical memory. 1679 For systems with a lot of RAM, this can be wasteful of precious 1680 low memory. Setting this option will put user-space page table 1681 entries in high memory. 1682 1683config X86_CHECK_BIOS_CORRUPTION 1684 bool "Check for low memory corruption" 1685 ---help--- 1686 Periodically check for memory corruption in low memory, which 1687 is suspected to be caused by BIOS. Even when enabled in the 1688 configuration, it is disabled at runtime. Enable it by 1689 setting "memory_corruption_check=1" on the kernel command 1690 line. By default it scans the low 64k of memory every 60 1691 seconds; see the memory_corruption_check_size and 1692 memory_corruption_check_period parameters in 1693 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1694 1695 When enabled with the default parameters, this option has 1696 almost no overhead, as it reserves a relatively small amount 1697 of memory and scans it infrequently. It both detects corruption 1698 and prevents it from affecting the running system. 1699 1700 It is, however, intended as a diagnostic tool; if repeatable 1701 BIOS-originated corruption always affects the same memory, 1702 you can use memmap= to prevent the kernel from using that 1703 memory. 1704 1705config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1706 bool "Set the default setting of memory_corruption_check" 1707 depends on X86_CHECK_BIOS_CORRUPTION 1708 default y 1709 ---help--- 1710 Set whether the default state of memory_corruption_check is 1711 on or off. 1712 1713config X86_RESERVE_LOW 1714 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1715 default 64 1716 range 4 640 1717 ---help--- 1718 Specify the amount of low memory to reserve for the BIOS. 1719 1720 The first page contains BIOS data structures that the kernel 1721 must not use, so that page must always be reserved. 1722 1723 By default we reserve the first 64K of physical RAM, as a 1724 number of BIOSes are known to corrupt that memory range 1725 during events such as suspend/resume or monitor cable 1726 insertion, so it must not be used by the kernel. 1727 1728 You can set this to 4 if you are absolutely sure that you 1729 trust the BIOS to get all its memory reservations and usages 1730 right. If you know your BIOS have problems beyond the 1731 default 64K area, you can set this to 640 to avoid using the 1732 entire low memory range. 1733 1734 If you have doubts about the BIOS (e.g. suspend/resume does 1735 not work or there's kernel crashes after certain hardware 1736 hotplug events) then you might want to enable 1737 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1738 typical corruption patterns. 1739 1740 Leave this to the default value of 64 if you are unsure. 1741 1742config MATH_EMULATION 1743 bool 1744 depends on MODIFY_LDT_SYSCALL 1745 prompt "Math emulation" if X86_32 1746 ---help--- 1747 Linux can emulate a math coprocessor (used for floating point 1748 operations) if you don't have one. 486DX and Pentium processors have 1749 a math coprocessor built in, 486SX and 386 do not, unless you added 1750 a 487DX or 387, respectively. (The messages during boot time can 1751 give you some hints here ["man dmesg"].) Everyone needs either a 1752 coprocessor or this emulation. 1753 1754 If you don't have a math coprocessor, you need to say Y here; if you 1755 say Y here even though you have a coprocessor, the coprocessor will 1756 be used nevertheless. (This behavior can be changed with the kernel 1757 command line option "no387", which comes handy if your coprocessor 1758 is broken. Try "man bootparam" or see the documentation of your boot 1759 loader (lilo or loadlin) about how to pass options to the kernel at 1760 boot time.) This means that it is a good idea to say Y here if you 1761 intend to use this kernel on different machines. 1762 1763 More information about the internals of the Linux math coprocessor 1764 emulation can be found in <file:arch/x86/math-emu/README>. 1765 1766 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1767 kernel, it won't hurt. 1768 1769config MTRR 1770 def_bool y 1771 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1772 ---help--- 1773 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1774 the Memory Type Range Registers (MTRRs) may be used to control 1775 processor access to memory ranges. This is most useful if you have 1776 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1777 allows bus write transfers to be combined into a larger transfer 1778 before bursting over the PCI/AGP bus. This can increase performance 1779 of image write operations 2.5 times or more. Saying Y here creates a 1780 /proc/mtrr file which may be used to manipulate your processor's 1781 MTRRs. Typically the X server should use this. 1782 1783 This code has a reasonably generic interface so that similar 1784 control registers on other processors can be easily supported 1785 as well: 1786 1787 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1788 Registers (ARRs) which provide a similar functionality to MTRRs. For 1789 these, the ARRs are used to emulate the MTRRs. 1790 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1791 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1792 write-combining. All of these processors are supported by this code 1793 and it makes sense to say Y here if you have one of them. 1794 1795 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1796 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1797 can lead to all sorts of problems, so it's good to say Y here. 1798 1799 You can safely say Y even if your machine doesn't have MTRRs, you'll 1800 just add about 9 KB to your kernel. 1801 1802 See <file:Documentation/x86/mtrr.txt> for more information. 1803 1804config MTRR_SANITIZER 1805 def_bool y 1806 prompt "MTRR cleanup support" 1807 depends on MTRR 1808 ---help--- 1809 Convert MTRR layout from continuous to discrete, so X drivers can 1810 add writeback entries. 1811 1812 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1813 The largest mtrr entry size for a continuous block can be set with 1814 mtrr_chunk_size. 1815 1816 If unsure, say Y. 1817 1818config MTRR_SANITIZER_ENABLE_DEFAULT 1819 int "MTRR cleanup enable value (0-1)" 1820 range 0 1 1821 default "0" 1822 depends on MTRR_SANITIZER 1823 ---help--- 1824 Enable mtrr cleanup default value 1825 1826config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1827 int "MTRR cleanup spare reg num (0-7)" 1828 range 0 7 1829 default "1" 1830 depends on MTRR_SANITIZER 1831 ---help--- 1832 mtrr cleanup spare entries default, it can be changed via 1833 mtrr_spare_reg_nr=N on the kernel command line. 1834 1835config X86_PAT 1836 def_bool y 1837 prompt "x86 PAT support" if EXPERT 1838 depends on MTRR 1839 ---help--- 1840 Use PAT attributes to setup page level cache control. 1841 1842 PATs are the modern equivalents of MTRRs and are much more 1843 flexible than MTRRs. 1844 1845 Say N here if you see bootup problems (boot crash, boot hang, 1846 spontaneous reboots) or a non-working video driver. 1847 1848 If unsure, say Y. 1849 1850config ARCH_USES_PG_UNCACHED 1851 def_bool y 1852 depends on X86_PAT 1853 1854config ARCH_RANDOM 1855 def_bool y 1856 prompt "x86 architectural random number generator" if EXPERT 1857 ---help--- 1858 Enable the x86 architectural RDRAND instruction 1859 (Intel Bull Mountain technology) to generate random numbers. 1860 If supported, this is a high bandwidth, cryptographically 1861 secure hardware random number generator. 1862 1863config X86_SMAP 1864 def_bool y 1865 prompt "Supervisor Mode Access Prevention" if EXPERT 1866 ---help--- 1867 Supervisor Mode Access Prevention (SMAP) is a security 1868 feature in newer Intel processors. There is a small 1869 performance cost if this enabled and turned on; there is 1870 also a small increase in the kernel size if this is enabled. 1871 1872 If unsure, say Y. 1873 1874config X86_INTEL_UMIP 1875 def_bool y 1876 depends on CPU_SUP_INTEL 1877 prompt "Intel User Mode Instruction Prevention" if EXPERT 1878 ---help--- 1879 The User Mode Instruction Prevention (UMIP) is a security 1880 feature in newer Intel processors. If enabled, a general 1881 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1882 or STR instructions are executed in user mode. These instructions 1883 unnecessarily expose information about the hardware state. 1884 1885 The vast majority of applications do not use these instructions. 1886 For the very few that do, software emulation is provided in 1887 specific cases in protected and virtual-8086 modes. Emulated 1888 results are dummy. 1889 1890config X86_INTEL_MPX 1891 prompt "Intel MPX (Memory Protection Extensions)" 1892 def_bool n 1893 # Note: only available in 64-bit mode due to VMA flags shortage 1894 depends on CPU_SUP_INTEL && X86_64 1895 select ARCH_USES_HIGH_VMA_FLAGS 1896 ---help--- 1897 MPX provides hardware features that can be used in 1898 conjunction with compiler-instrumented code to check 1899 memory references. It is designed to detect buffer 1900 overflow or underflow bugs. 1901 1902 This option enables running applications which are 1903 instrumented or otherwise use MPX. It does not use MPX 1904 itself inside the kernel or to protect the kernel 1905 against bad memory references. 1906 1907 Enabling this option will make the kernel larger: 1908 ~8k of kernel text and 36 bytes of data on a 64-bit 1909 defconfig. It adds a long to the 'mm_struct' which 1910 will increase the kernel memory overhead of each 1911 process and adds some branches to paths used during 1912 exec() and munmap(). 1913 1914 For details, see Documentation/x86/intel_mpx.txt 1915 1916 If unsure, say N. 1917 1918config X86_INTEL_MEMORY_PROTECTION_KEYS 1919 prompt "Intel Memory Protection Keys" 1920 def_bool y 1921 # Note: only available in 64-bit mode 1922 depends on CPU_SUP_INTEL && X86_64 1923 select ARCH_USES_HIGH_VMA_FLAGS 1924 select ARCH_HAS_PKEYS 1925 ---help--- 1926 Memory Protection Keys provides a mechanism for enforcing 1927 page-based protections, but without requiring modification of the 1928 page tables when an application changes protection domains. 1929 1930 For details, see Documentation/x86/protection-keys.txt 1931 1932 If unsure, say y. 1933 1934config EFI 1935 bool "EFI runtime service support" 1936 depends on ACPI 1937 select UCS2_STRING 1938 select EFI_RUNTIME_WRAPPERS 1939 ---help--- 1940 This enables the kernel to use EFI runtime services that are 1941 available (such as the EFI variable services). 1942 1943 This option is only useful on systems that have EFI firmware. 1944 In addition, you should use the latest ELILO loader available 1945 at <http://elilo.sourceforge.net> in order to take advantage 1946 of EFI runtime services. However, even with this option, the 1947 resultant kernel should continue to boot on existing non-EFI 1948 platforms. 1949 1950config EFI_STUB 1951 bool "EFI stub support" 1952 depends on EFI && !X86_USE_3DNOW 1953 select RELOCATABLE 1954 ---help--- 1955 This kernel feature allows a bzImage to be loaded directly 1956 by EFI firmware without the use of a bootloader. 1957 1958 See Documentation/efi-stub.txt for more information. 1959 1960config EFI_MIXED 1961 bool "EFI mixed-mode support" 1962 depends on EFI_STUB && X86_64 1963 ---help--- 1964 Enabling this feature allows a 64-bit kernel to be booted 1965 on a 32-bit firmware, provided that your CPU supports 64-bit 1966 mode. 1967 1968 Note that it is not possible to boot a mixed-mode enabled 1969 kernel via the EFI boot stub - a bootloader that supports 1970 the EFI handover protocol must be used. 1971 1972 If unsure, say N. 1973 1974config SECCOMP 1975 def_bool y 1976 prompt "Enable seccomp to safely compute untrusted bytecode" 1977 ---help--- 1978 This kernel feature is useful for number crunching applications 1979 that may need to compute untrusted bytecode during their 1980 execution. By using pipes or other transports made available to 1981 the process as file descriptors supporting the read/write 1982 syscalls, it's possible to isolate those applications in 1983 their own address space using seccomp. Once seccomp is 1984 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1985 and the task is only allowed to execute a few safe syscalls 1986 defined by each seccomp mode. 1987 1988 If unsure, say Y. Only embedded should say N here. 1989 1990source kernel/Kconfig.hz 1991 1992config KEXEC 1993 bool "kexec system call" 1994 select KEXEC_CORE 1995 ---help--- 1996 kexec is a system call that implements the ability to shutdown your 1997 current kernel, and to start another kernel. It is like a reboot 1998 but it is independent of the system firmware. And like a reboot 1999 you can start any kernel with it, not just Linux. 2000 2001 The name comes from the similarity to the exec system call. 2002 2003 It is an ongoing process to be certain the hardware in a machine 2004 is properly shutdown, so do not be surprised if this code does not 2005 initially work for you. As of this writing the exact hardware 2006 interface is strongly in flux, so no good recommendation can be 2007 made. 2008 2009config KEXEC_FILE 2010 bool "kexec file based system call" 2011 select KEXEC_CORE 2012 select BUILD_BIN2C 2013 depends on X86_64 2014 depends on CRYPTO=y 2015 depends on CRYPTO_SHA256=y 2016 ---help--- 2017 This is new version of kexec system call. This system call is 2018 file based and takes file descriptors as system call argument 2019 for kernel and initramfs as opposed to list of segments as 2020 accepted by previous system call. 2021 2022config KEXEC_VERIFY_SIG 2023 bool "Verify kernel signature during kexec_file_load() syscall" 2024 depends on KEXEC_FILE 2025 ---help--- 2026 This option makes kernel signature verification mandatory for 2027 the kexec_file_load() syscall. 2028 2029 In addition to that option, you need to enable signature 2030 verification for the corresponding kernel image type being 2031 loaded in order for this to work. 2032 2033config KEXEC_BZIMAGE_VERIFY_SIG 2034 bool "Enable bzImage signature verification support" 2035 depends on KEXEC_VERIFY_SIG 2036 depends on SIGNED_PE_FILE_VERIFICATION 2037 select SYSTEM_TRUSTED_KEYRING 2038 ---help--- 2039 Enable bzImage signature verification support. 2040 2041config CRASH_DUMP 2042 bool "kernel crash dumps" 2043 depends on X86_64 || (X86_32 && HIGHMEM) 2044 ---help--- 2045 Generate crash dump after being started by kexec. 2046 This should be normally only set in special crash dump kernels 2047 which are loaded in the main kernel with kexec-tools into 2048 a specially reserved region and then later executed after 2049 a crash by kdump/kexec. The crash dump kernel must be compiled 2050 to a memory address not used by the main kernel or BIOS using 2051 PHYSICAL_START, or it must be built as a relocatable image 2052 (CONFIG_RELOCATABLE=y). 2053 For more details see Documentation/kdump/kdump.txt 2054 2055config KEXEC_JUMP 2056 bool "kexec jump" 2057 depends on KEXEC && HIBERNATION 2058 ---help--- 2059 Jump between original kernel and kexeced kernel and invoke 2060 code in physical address mode via KEXEC 2061 2062config PHYSICAL_START 2063 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2064 default "0x1000000" 2065 ---help--- 2066 This gives the physical address where the kernel is loaded. 2067 2068 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2069 bzImage will decompress itself to above physical address and 2070 run from there. Otherwise, bzImage will run from the address where 2071 it has been loaded by the boot loader and will ignore above physical 2072 address. 2073 2074 In normal kdump cases one does not have to set/change this option 2075 as now bzImage can be compiled as a completely relocatable image 2076 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2077 address. This option is mainly useful for the folks who don't want 2078 to use a bzImage for capturing the crash dump and want to use a 2079 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2080 to be specifically compiled to run from a specific memory area 2081 (normally a reserved region) and this option comes handy. 2082 2083 So if you are using bzImage for capturing the crash dump, 2084 leave the value here unchanged to 0x1000000 and set 2085 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2086 for capturing the crash dump change this value to start of 2087 the reserved region. In other words, it can be set based on 2088 the "X" value as specified in the "crashkernel=YM@XM" 2089 command line boot parameter passed to the panic-ed 2090 kernel. Please take a look at Documentation/kdump/kdump.txt 2091 for more details about crash dumps. 2092 2093 Usage of bzImage for capturing the crash dump is recommended as 2094 one does not have to build two kernels. Same kernel can be used 2095 as production kernel and capture kernel. Above option should have 2096 gone away after relocatable bzImage support is introduced. But it 2097 is present because there are users out there who continue to use 2098 vmlinux for dump capture. This option should go away down the 2099 line. 2100 2101 Don't change this unless you know what you are doing. 2102 2103config RELOCATABLE 2104 bool "Build a relocatable kernel" 2105 default y 2106 ---help--- 2107 This builds a kernel image that retains relocation information 2108 so it can be loaded someplace besides the default 1MB. 2109 The relocations tend to make the kernel binary about 10% larger, 2110 but are discarded at runtime. 2111 2112 One use is for the kexec on panic case where the recovery kernel 2113 must live at a different physical address than the primary 2114 kernel. 2115 2116 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2117 it has been loaded at and the compile time physical address 2118 (CONFIG_PHYSICAL_START) is used as the minimum location. 2119 2120config RANDOMIZE_BASE 2121 bool "Randomize the address of the kernel image (KASLR)" 2122 depends on RELOCATABLE 2123 default y 2124 ---help--- 2125 In support of Kernel Address Space Layout Randomization (KASLR), 2126 this randomizes the physical address at which the kernel image 2127 is decompressed and the virtual address where the kernel 2128 image is mapped, as a security feature that deters exploit 2129 attempts relying on knowledge of the location of kernel 2130 code internals. 2131 2132 On 64-bit, the kernel physical and virtual addresses are 2133 randomized separately. The physical address will be anywhere 2134 between 16MB and the top of physical memory (up to 64TB). The 2135 virtual address will be randomized from 16MB up to 1GB (9 bits 2136 of entropy). Note that this also reduces the memory space 2137 available to kernel modules from 1.5GB to 1GB. 2138 2139 On 32-bit, the kernel physical and virtual addresses are 2140 randomized together. They will be randomized from 16MB up to 2141 512MB (8 bits of entropy). 2142 2143 Entropy is generated using the RDRAND instruction if it is 2144 supported. If RDTSC is supported, its value is mixed into 2145 the entropy pool as well. If neither RDRAND nor RDTSC are 2146 supported, then entropy is read from the i8254 timer. The 2147 usable entropy is limited by the kernel being built using 2148 2GB addressing, and that PHYSICAL_ALIGN must be at a 2149 minimum of 2MB. As a result, only 10 bits of entropy are 2150 theoretically possible, but the implementations are further 2151 limited due to memory layouts. 2152 2153 If unsure, say Y. 2154 2155# Relocation on x86 needs some additional build support 2156config X86_NEED_RELOCS 2157 def_bool y 2158 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2159 2160config PHYSICAL_ALIGN 2161 hex "Alignment value to which kernel should be aligned" 2162 default "0x200000" 2163 range 0x2000 0x1000000 if X86_32 2164 range 0x200000 0x1000000 if X86_64 2165 ---help--- 2166 This value puts the alignment restrictions on physical address 2167 where kernel is loaded and run from. Kernel is compiled for an 2168 address which meets above alignment restriction. 2169 2170 If bootloader loads the kernel at a non-aligned address and 2171 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2172 address aligned to above value and run from there. 2173 2174 If bootloader loads the kernel at a non-aligned address and 2175 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2176 load address and decompress itself to the address it has been 2177 compiled for and run from there. The address for which kernel is 2178 compiled already meets above alignment restrictions. Hence the 2179 end result is that kernel runs from a physical address meeting 2180 above alignment restrictions. 2181 2182 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2183 this value must be a multiple of 0x200000. 2184 2185 Don't change this unless you know what you are doing. 2186 2187config RANDOMIZE_MEMORY 2188 bool "Randomize the kernel memory sections" 2189 depends on X86_64 2190 depends on RANDOMIZE_BASE 2191 default RANDOMIZE_BASE 2192 ---help--- 2193 Randomizes the base virtual address of kernel memory sections 2194 (physical memory mapping, vmalloc & vmemmap). This security feature 2195 makes exploits relying on predictable memory locations less reliable. 2196 2197 The order of allocations remains unchanged. Entropy is generated in 2198 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2199 configuration have in average 30,000 different possible virtual 2200 addresses for each memory section. 2201 2202 If unsure, say Y. 2203 2204config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2205 hex "Physical memory mapping padding" if EXPERT 2206 depends on RANDOMIZE_MEMORY 2207 default "0xa" if MEMORY_HOTPLUG 2208 default "0x0" 2209 range 0x1 0x40 if MEMORY_HOTPLUG 2210 range 0x0 0x40 2211 ---help--- 2212 Define the padding in terabytes added to the existing physical 2213 memory size during kernel memory randomization. It is useful 2214 for memory hotplug support but reduces the entropy available for 2215 address randomization. 2216 2217 If unsure, leave at the default value. 2218 2219config HOTPLUG_CPU 2220 bool "Support for hot-pluggable CPUs" 2221 depends on SMP 2222 ---help--- 2223 Say Y here to allow turning CPUs off and on. CPUs can be 2224 controlled through /sys/devices/system/cpu. 2225 ( Note: power management support will enable this option 2226 automatically on SMP systems. ) 2227 Say N if you want to disable CPU hotplug. 2228 2229config BOOTPARAM_HOTPLUG_CPU0 2230 bool "Set default setting of cpu0_hotpluggable" 2231 default n 2232 depends on HOTPLUG_CPU 2233 ---help--- 2234 Set whether default state of cpu0_hotpluggable is on or off. 2235 2236 Say Y here to enable CPU0 hotplug by default. If this switch 2237 is turned on, there is no need to give cpu0_hotplug kernel 2238 parameter and the CPU0 hotplug feature is enabled by default. 2239 2240 Please note: there are two known CPU0 dependencies if you want 2241 to enable the CPU0 hotplug feature either by this switch or by 2242 cpu0_hotplug kernel parameter. 2243 2244 First, resume from hibernate or suspend always starts from CPU0. 2245 So hibernate and suspend are prevented if CPU0 is offline. 2246 2247 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2248 offline if any interrupt can not migrate out of CPU0. There may 2249 be other CPU0 dependencies. 2250 2251 Please make sure the dependencies are under your control before 2252 you enable this feature. 2253 2254 Say N if you don't want to enable CPU0 hotplug feature by default. 2255 You still can enable the CPU0 hotplug feature at boot by kernel 2256 parameter cpu0_hotplug. 2257 2258config DEBUG_HOTPLUG_CPU0 2259 def_bool n 2260 prompt "Debug CPU0 hotplug" 2261 depends on HOTPLUG_CPU 2262 ---help--- 2263 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2264 soon as possible and boots up userspace with CPU0 offlined. User 2265 can online CPU0 back after boot time. 2266 2267 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2268 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2269 compilation or giving cpu0_hotplug kernel parameter at boot. 2270 2271 If unsure, say N. 2272 2273config COMPAT_VDSO 2274 def_bool n 2275 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2276 depends on COMPAT_32 2277 ---help--- 2278 Certain buggy versions of glibc will crash if they are 2279 presented with a 32-bit vDSO that is not mapped at the address 2280 indicated in its segment table. 2281 2282 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2283 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2284 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2285 the only released version with the bug, but OpenSUSE 9 2286 contains a buggy "glibc 2.3.2". 2287 2288 The symptom of the bug is that everything crashes on startup, saying: 2289 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2290 2291 Saying Y here changes the default value of the vdso32 boot 2292 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2293 This works around the glibc bug but hurts performance. 2294 2295 If unsure, say N: if you are compiling your own kernel, you 2296 are unlikely to be using a buggy version of glibc. 2297 2298choice 2299 prompt "vsyscall table for legacy applications" 2300 depends on X86_64 2301 default LEGACY_VSYSCALL_EMULATE 2302 help 2303 Legacy user code that does not know how to find the vDSO expects 2304 to be able to issue three syscalls by calling fixed addresses in 2305 kernel space. Since this location is not randomized with ASLR, 2306 it can be used to assist security vulnerability exploitation. 2307 2308 This setting can be changed at boot time via the kernel command 2309 line parameter vsyscall=[native|emulate|none]. 2310 2311 On a system with recent enough glibc (2.14 or newer) and no 2312 static binaries, you can say None without a performance penalty 2313 to improve security. 2314 2315 If unsure, select "Emulate". 2316 2317 config LEGACY_VSYSCALL_NATIVE 2318 bool "Native" 2319 help 2320 Actual executable code is located in the fixed vsyscall 2321 address mapping, implementing time() efficiently. Since 2322 this makes the mapping executable, it can be used during 2323 security vulnerability exploitation (traditionally as 2324 ROP gadgets). This configuration is not recommended. 2325 2326 config LEGACY_VSYSCALL_EMULATE 2327 bool "Emulate" 2328 help 2329 The kernel traps and emulates calls into the fixed 2330 vsyscall address mapping. This makes the mapping 2331 non-executable, but it still contains known contents, 2332 which could be used in certain rare security vulnerability 2333 exploits. This configuration is recommended when userspace 2334 still uses the vsyscall area. 2335 2336 config LEGACY_VSYSCALL_NONE 2337 bool "None" 2338 help 2339 There will be no vsyscall mapping at all. This will 2340 eliminate any risk of ASLR bypass due to the vsyscall 2341 fixed address mapping. Attempts to use the vsyscalls 2342 will be reported to dmesg, so that either old or 2343 malicious userspace programs can be identified. 2344 2345endchoice 2346 2347config CMDLINE_BOOL 2348 bool "Built-in kernel command line" 2349 ---help--- 2350 Allow for specifying boot arguments to the kernel at 2351 build time. On some systems (e.g. embedded ones), it is 2352 necessary or convenient to provide some or all of the 2353 kernel boot arguments with the kernel itself (that is, 2354 to not rely on the boot loader to provide them.) 2355 2356 To compile command line arguments into the kernel, 2357 set this option to 'Y', then fill in the 2358 boot arguments in CONFIG_CMDLINE. 2359 2360 Systems with fully functional boot loaders (i.e. non-embedded) 2361 should leave this option set to 'N'. 2362 2363config CMDLINE 2364 string "Built-in kernel command string" 2365 depends on CMDLINE_BOOL 2366 default "" 2367 ---help--- 2368 Enter arguments here that should be compiled into the kernel 2369 image and used at boot time. If the boot loader provides a 2370 command line at boot time, it is appended to this string to 2371 form the full kernel command line, when the system boots. 2372 2373 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2374 change this behavior. 2375 2376 In most cases, the command line (whether built-in or provided 2377 by the boot loader) should specify the device for the root 2378 file system. 2379 2380config CMDLINE_OVERRIDE 2381 bool "Built-in command line overrides boot loader arguments" 2382 depends on CMDLINE_BOOL 2383 ---help--- 2384 Set this option to 'Y' to have the kernel ignore the boot loader 2385 command line, and use ONLY the built-in command line. 2386 2387 This is used to work around broken boot loaders. This should 2388 be set to 'N' under normal conditions. 2389 2390config MODIFY_LDT_SYSCALL 2391 bool "Enable the LDT (local descriptor table)" if EXPERT 2392 default y 2393 ---help--- 2394 Linux can allow user programs to install a per-process x86 2395 Local Descriptor Table (LDT) using the modify_ldt(2) system 2396 call. This is required to run 16-bit or segmented code such as 2397 DOSEMU or some Wine programs. It is also used by some very old 2398 threading libraries. 2399 2400 Enabling this feature adds a small amount of overhead to 2401 context switches and increases the low-level kernel attack 2402 surface. Disabling it removes the modify_ldt(2) system call. 2403 2404 Saying 'N' here may make sense for embedded or server kernels. 2405 2406source "kernel/livepatch/Kconfig" 2407 2408endmenu 2409 2410config ARCH_HAS_ADD_PAGES 2411 def_bool y 2412 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2413 2414config ARCH_ENABLE_MEMORY_HOTPLUG 2415 def_bool y 2416 depends on X86_64 || (X86_32 && HIGHMEM) 2417 2418config ARCH_ENABLE_MEMORY_HOTREMOVE 2419 def_bool y 2420 depends on MEMORY_HOTPLUG 2421 2422config USE_PERCPU_NUMA_NODE_ID 2423 def_bool y 2424 depends on NUMA 2425 2426config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2427 def_bool y 2428 depends on X86_64 || X86_PAE 2429 2430config ARCH_ENABLE_HUGEPAGE_MIGRATION 2431 def_bool y 2432 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2433 2434config ARCH_ENABLE_THP_MIGRATION 2435 def_bool y 2436 depends on X86_64 && TRANSPARENT_HUGEPAGE 2437 2438menu "Power management and ACPI options" 2439 2440config ARCH_HIBERNATION_HEADER 2441 def_bool y 2442 depends on X86_64 && HIBERNATION 2443 2444source "kernel/power/Kconfig" 2445 2446source "drivers/acpi/Kconfig" 2447 2448source "drivers/sfi/Kconfig" 2449 2450config X86_APM_BOOT 2451 def_bool y 2452 depends on APM 2453 2454menuconfig APM 2455 tristate "APM (Advanced Power Management) BIOS support" 2456 depends on X86_32 && PM_SLEEP 2457 ---help--- 2458 APM is a BIOS specification for saving power using several different 2459 techniques. This is mostly useful for battery powered laptops with 2460 APM compliant BIOSes. If you say Y here, the system time will be 2461 reset after a RESUME operation, the /proc/apm device will provide 2462 battery status information, and user-space programs will receive 2463 notification of APM "events" (e.g. battery status change). 2464 2465 If you select "Y" here, you can disable actual use of the APM 2466 BIOS by passing the "apm=off" option to the kernel at boot time. 2467 2468 Note that the APM support is almost completely disabled for 2469 machines with more than one CPU. 2470 2471 In order to use APM, you will need supporting software. For location 2472 and more information, read <file:Documentation/power/apm-acpi.txt> 2473 and the Battery Powered Linux mini-HOWTO, available from 2474 <http://www.tldp.org/docs.html#howto>. 2475 2476 This driver does not spin down disk drives (see the hdparm(8) 2477 manpage ("man 8 hdparm") for that), and it doesn't turn off 2478 VESA-compliant "green" monitors. 2479 2480 This driver does not support the TI 4000M TravelMate and the ACER 2481 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2482 desktop machines also don't have compliant BIOSes, and this driver 2483 may cause those machines to panic during the boot phase. 2484 2485 Generally, if you don't have a battery in your machine, there isn't 2486 much point in using this driver and you should say N. If you get 2487 random kernel OOPSes or reboots that don't seem to be related to 2488 anything, try disabling/enabling this option (or disabling/enabling 2489 APM in your BIOS). 2490 2491 Some other things you should try when experiencing seemingly random, 2492 "weird" problems: 2493 2494 1) make sure that you have enough swap space and that it is 2495 enabled. 2496 2) pass the "no-hlt" option to the kernel 2497 3) switch on floating point emulation in the kernel and pass 2498 the "no387" option to the kernel 2499 4) pass the "floppy=nodma" option to the kernel 2500 5) pass the "mem=4M" option to the kernel (thereby disabling 2501 all but the first 4 MB of RAM) 2502 6) make sure that the CPU is not over clocked. 2503 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2504 8) disable the cache from your BIOS settings 2505 9) install a fan for the video card or exchange video RAM 2506 10) install a better fan for the CPU 2507 11) exchange RAM chips 2508 12) exchange the motherboard. 2509 2510 To compile this driver as a module, choose M here: the 2511 module will be called apm. 2512 2513if APM 2514 2515config APM_IGNORE_USER_SUSPEND 2516 bool "Ignore USER SUSPEND" 2517 ---help--- 2518 This option will ignore USER SUSPEND requests. On machines with a 2519 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2520 series notebooks, it is necessary to say Y because of a BIOS bug. 2521 2522config APM_DO_ENABLE 2523 bool "Enable PM at boot time" 2524 ---help--- 2525 Enable APM features at boot time. From page 36 of the APM BIOS 2526 specification: "When disabled, the APM BIOS does not automatically 2527 power manage devices, enter the Standby State, enter the Suspend 2528 State, or take power saving steps in response to CPU Idle calls." 2529 This driver will make CPU Idle calls when Linux is idle (unless this 2530 feature is turned off -- see "Do CPU IDLE calls", below). This 2531 should always save battery power, but more complicated APM features 2532 will be dependent on your BIOS implementation. You may need to turn 2533 this option off if your computer hangs at boot time when using APM 2534 support, or if it beeps continuously instead of suspending. Turn 2535 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2536 T400CDT. This is off by default since most machines do fine without 2537 this feature. 2538 2539config APM_CPU_IDLE 2540 depends on CPU_IDLE 2541 bool "Make CPU Idle calls when idle" 2542 ---help--- 2543 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2544 On some machines, this can activate improved power savings, such as 2545 a slowed CPU clock rate, when the machine is idle. These idle calls 2546 are made after the idle loop has run for some length of time (e.g., 2547 333 mS). On some machines, this will cause a hang at boot time or 2548 whenever the CPU becomes idle. (On machines with more than one CPU, 2549 this option does nothing.) 2550 2551config APM_DISPLAY_BLANK 2552 bool "Enable console blanking using APM" 2553 ---help--- 2554 Enable console blanking using the APM. Some laptops can use this to 2555 turn off the LCD backlight when the screen blanker of the Linux 2556 virtual console blanks the screen. Note that this is only used by 2557 the virtual console screen blanker, and won't turn off the backlight 2558 when using the X Window system. This also doesn't have anything to 2559 do with your VESA-compliant power-saving monitor. Further, this 2560 option doesn't work for all laptops -- it might not turn off your 2561 backlight at all, or it might print a lot of errors to the console, 2562 especially if you are using gpm. 2563 2564config APM_ALLOW_INTS 2565 bool "Allow interrupts during APM BIOS calls" 2566 ---help--- 2567 Normally we disable external interrupts while we are making calls to 2568 the APM BIOS as a measure to lessen the effects of a badly behaving 2569 BIOS implementation. The BIOS should reenable interrupts if it 2570 needs to. Unfortunately, some BIOSes do not -- especially those in 2571 many of the newer IBM Thinkpads. If you experience hangs when you 2572 suspend, try setting this to Y. Otherwise, say N. 2573 2574endif # APM 2575 2576source "drivers/cpufreq/Kconfig" 2577 2578source "drivers/cpuidle/Kconfig" 2579 2580source "drivers/idle/Kconfig" 2581 2582endmenu 2583 2584 2585menu "Bus options (PCI etc.)" 2586 2587config PCI 2588 bool "PCI support" 2589 default y 2590 ---help--- 2591 Find out whether you have a PCI motherboard. PCI is the name of a 2592 bus system, i.e. the way the CPU talks to the other stuff inside 2593 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2594 VESA. If you have PCI, say Y, otherwise N. 2595 2596choice 2597 prompt "PCI access mode" 2598 depends on X86_32 && PCI 2599 default PCI_GOANY 2600 ---help--- 2601 On PCI systems, the BIOS can be used to detect the PCI devices and 2602 determine their configuration. However, some old PCI motherboards 2603 have BIOS bugs and may crash if this is done. Also, some embedded 2604 PCI-based systems don't have any BIOS at all. Linux can also try to 2605 detect the PCI hardware directly without using the BIOS. 2606 2607 With this option, you can specify how Linux should detect the 2608 PCI devices. If you choose "BIOS", the BIOS will be used, 2609 if you choose "Direct", the BIOS won't be used, and if you 2610 choose "MMConfig", then PCI Express MMCONFIG will be used. 2611 If you choose "Any", the kernel will try MMCONFIG, then the 2612 direct access method and falls back to the BIOS if that doesn't 2613 work. If unsure, go with the default, which is "Any". 2614 2615config PCI_GOBIOS 2616 bool "BIOS" 2617 2618config PCI_GOMMCONFIG 2619 bool "MMConfig" 2620 2621config PCI_GODIRECT 2622 bool "Direct" 2623 2624config PCI_GOOLPC 2625 bool "OLPC XO-1" 2626 depends on OLPC 2627 2628config PCI_GOANY 2629 bool "Any" 2630 2631endchoice 2632 2633config PCI_BIOS 2634 def_bool y 2635 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2636 2637# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2638config PCI_DIRECT 2639 def_bool y 2640 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2641 2642config PCI_MMCONFIG 2643 def_bool y 2644 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2645 2646config PCI_OLPC 2647 def_bool y 2648 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2649 2650config PCI_XEN 2651 def_bool y 2652 depends on PCI && XEN 2653 select SWIOTLB_XEN 2654 2655config PCI_DOMAINS 2656 def_bool y 2657 depends on PCI 2658 2659config PCI_MMCONFIG 2660 bool "Support mmconfig PCI config space access" 2661 depends on X86_64 && PCI && ACPI 2662 2663config PCI_CNB20LE_QUIRK 2664 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2665 depends on PCI 2666 help 2667 Read the PCI windows out of the CNB20LE host bridge. This allows 2668 PCI hotplug to work on systems with the CNB20LE chipset which do 2669 not have ACPI. 2670 2671 There's no public spec for this chipset, and this functionality 2672 is known to be incomplete. 2673 2674 You should say N unless you know you need this. 2675 2676source "drivers/pci/Kconfig" 2677 2678config ISA_BUS 2679 bool "ISA-style bus support on modern systems" if EXPERT 2680 select ISA_BUS_API 2681 help 2682 Enables ISA-style drivers on modern systems. This is necessary to 2683 support PC/104 devices on X86_64 platforms. 2684 2685 If unsure, say N. 2686 2687# x86_64 have no ISA slots, but can have ISA-style DMA. 2688config ISA_DMA_API 2689 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2690 default y 2691 help 2692 Enables ISA-style DMA support for devices requiring such controllers. 2693 If unsure, say Y. 2694 2695if X86_32 2696 2697config ISA 2698 bool "ISA support" 2699 ---help--- 2700 Find out whether you have ISA slots on your motherboard. ISA is the 2701 name of a bus system, i.e. the way the CPU talks to the other stuff 2702 inside your box. Other bus systems are PCI, EISA, MicroChannel 2703 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2704 newer boards don't support it. If you have ISA, say Y, otherwise N. 2705 2706config EISA 2707 bool "EISA support" 2708 depends on ISA 2709 ---help--- 2710 The Extended Industry Standard Architecture (EISA) bus was 2711 developed as an open alternative to the IBM MicroChannel bus. 2712 2713 The EISA bus provided some of the features of the IBM MicroChannel 2714 bus while maintaining backward compatibility with cards made for 2715 the older ISA bus. The EISA bus saw limited use between 1988 and 2716 1995 when it was made obsolete by the PCI bus. 2717 2718 Say Y here if you are building a kernel for an EISA-based machine. 2719 2720 Otherwise, say N. 2721 2722source "drivers/eisa/Kconfig" 2723 2724config SCx200 2725 tristate "NatSemi SCx200 support" 2726 ---help--- 2727 This provides basic support for National Semiconductor's 2728 (now AMD's) Geode processors. The driver probes for the 2729 PCI-IDs of several on-chip devices, so its a good dependency 2730 for other scx200_* drivers. 2731 2732 If compiled as a module, the driver is named scx200. 2733 2734config SCx200HR_TIMER 2735 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2736 depends on SCx200 2737 default y 2738 ---help--- 2739 This driver provides a clocksource built upon the on-chip 2740 27MHz high-resolution timer. Its also a workaround for 2741 NSC Geode SC-1100's buggy TSC, which loses time when the 2742 processor goes idle (as is done by the scheduler). The 2743 other workaround is idle=poll boot option. 2744 2745config OLPC 2746 bool "One Laptop Per Child support" 2747 depends on !X86_PAE 2748 select GPIOLIB 2749 select OF 2750 select OF_PROMTREE 2751 select IRQ_DOMAIN 2752 ---help--- 2753 Add support for detecting the unique features of the OLPC 2754 XO hardware. 2755 2756config OLPC_XO1_PM 2757 bool "OLPC XO-1 Power Management" 2758 depends on OLPC && MFD_CS5535 && PM_SLEEP 2759 select MFD_CORE 2760 ---help--- 2761 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2762 2763config OLPC_XO1_RTC 2764 bool "OLPC XO-1 Real Time Clock" 2765 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2766 ---help--- 2767 Add support for the XO-1 real time clock, which can be used as a 2768 programmable wakeup source. 2769 2770config OLPC_XO1_SCI 2771 bool "OLPC XO-1 SCI extras" 2772 depends on OLPC && OLPC_XO1_PM 2773 depends on INPUT=y 2774 select POWER_SUPPLY 2775 select GPIO_CS5535 2776 select MFD_CORE 2777 ---help--- 2778 Add support for SCI-based features of the OLPC XO-1 laptop: 2779 - EC-driven system wakeups 2780 - Power button 2781 - Ebook switch 2782 - Lid switch 2783 - AC adapter status updates 2784 - Battery status updates 2785 2786config OLPC_XO15_SCI 2787 bool "OLPC XO-1.5 SCI extras" 2788 depends on OLPC && ACPI 2789 select POWER_SUPPLY 2790 ---help--- 2791 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2792 - EC-driven system wakeups 2793 - AC adapter status updates 2794 - Battery status updates 2795 2796config ALIX 2797 bool "PCEngines ALIX System Support (LED setup)" 2798 select GPIOLIB 2799 ---help--- 2800 This option enables system support for the PCEngines ALIX. 2801 At present this just sets up LEDs for GPIO control on 2802 ALIX2/3/6 boards. However, other system specific setup should 2803 get added here. 2804 2805 Note: You must still enable the drivers for GPIO and LED support 2806 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2807 2808 Note: You have to set alix.force=1 for boards with Award BIOS. 2809 2810config NET5501 2811 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2812 select GPIOLIB 2813 ---help--- 2814 This option enables system support for the Soekris Engineering net5501. 2815 2816config GEOS 2817 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2818 select GPIOLIB 2819 depends on DMI 2820 ---help--- 2821 This option enables system support for the Traverse Technologies GEOS. 2822 2823config TS5500 2824 bool "Technologic Systems TS-5500 platform support" 2825 depends on MELAN 2826 select CHECK_SIGNATURE 2827 select NEW_LEDS 2828 select LEDS_CLASS 2829 ---help--- 2830 This option enables system support for the Technologic Systems TS-5500. 2831 2832endif # X86_32 2833 2834config AMD_NB 2835 def_bool y 2836 depends on CPU_SUP_AMD && PCI 2837 2838source "drivers/pcmcia/Kconfig" 2839 2840config RAPIDIO 2841 tristate "RapidIO support" 2842 depends on PCI 2843 default n 2844 help 2845 If enabled this option will include drivers and the core 2846 infrastructure code to support RapidIO interconnect devices. 2847 2848source "drivers/rapidio/Kconfig" 2849 2850config X86_SYSFB 2851 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2852 help 2853 Firmwares often provide initial graphics framebuffers so the BIOS, 2854 bootloader or kernel can show basic video-output during boot for 2855 user-guidance and debugging. Historically, x86 used the VESA BIOS 2856 Extensions and EFI-framebuffers for this, which are mostly limited 2857 to x86. 2858 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2859 framebuffers so the new generic system-framebuffer drivers can be 2860 used on x86. If the framebuffer is not compatible with the generic 2861 modes, it is adverticed as fallback platform framebuffer so legacy 2862 drivers like efifb, vesafb and uvesafb can pick it up. 2863 If this option is not selected, all system framebuffers are always 2864 marked as fallback platform framebuffers as usual. 2865 2866 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2867 not be able to pick up generic system framebuffers if this option 2868 is selected. You are highly encouraged to enable simplefb as 2869 replacement if you select this option. simplefb can correctly deal 2870 with generic system framebuffers. But you should still keep vesafb 2871 and others enabled as fallback if a system framebuffer is 2872 incompatible with simplefb. 2873 2874 If unsure, say Y. 2875 2876endmenu 2877 2878 2879menu "Executable file formats / Emulations" 2880 2881source "fs/Kconfig.binfmt" 2882 2883config IA32_EMULATION 2884 bool "IA32 Emulation" 2885 depends on X86_64 2886 select ARCH_WANT_OLD_COMPAT_IPC 2887 select BINFMT_ELF 2888 select COMPAT_BINFMT_ELF 2889 select COMPAT_OLD_SIGACTION 2890 ---help--- 2891 Include code to run legacy 32-bit programs under a 2892 64-bit kernel. You should likely turn this on, unless you're 2893 100% sure that you don't have any 32-bit programs left. 2894 2895config IA32_AOUT 2896 tristate "IA32 a.out support" 2897 depends on IA32_EMULATION 2898 ---help--- 2899 Support old a.out binaries in the 32bit emulation. 2900 2901config X86_X32 2902 bool "x32 ABI for 64-bit mode" 2903 depends on X86_64 2904 ---help--- 2905 Include code to run binaries for the x32 native 32-bit ABI 2906 for 64-bit processors. An x32 process gets access to the 2907 full 64-bit register file and wide data path while leaving 2908 pointers at 32 bits for smaller memory footprint. 2909 2910 You will need a recent binutils (2.22 or later) with 2911 elf32_x86_64 support enabled to compile a kernel with this 2912 option set. 2913 2914config COMPAT_32 2915 def_bool y 2916 depends on IA32_EMULATION || X86_32 2917 select HAVE_UID16 2918 select OLD_SIGSUSPEND3 2919 2920config COMPAT 2921 def_bool y 2922 depends on IA32_EMULATION || X86_X32 2923 2924if COMPAT 2925config COMPAT_FOR_U64_ALIGNMENT 2926 def_bool y 2927 2928config SYSVIPC_COMPAT 2929 def_bool y 2930 depends on SYSVIPC 2931endif 2932 2933endmenu 2934 2935 2936config HAVE_ATOMIC_IOMAP 2937 def_bool y 2938 depends on X86_32 2939 2940config X86_DEV_DMA_OPS 2941 bool 2942 depends on X86_64 || STA2X11 2943 2944config X86_DMA_REMAP 2945 bool 2946 depends on STA2X11 2947 2948config HAVE_GENERIC_GUP 2949 def_bool y 2950 2951source "net/Kconfig" 2952 2953source "drivers/Kconfig" 2954 2955source "drivers/firmware/Kconfig" 2956 2957source "fs/Kconfig" 2958 2959source "arch/x86/Kconfig.debug" 2960 2961source "security/Kconfig" 2962 2963source "crypto/Kconfig" 2964 2965source "arch/x86/kvm/Kconfig" 2966 2967source "lib/Kconfig" 2968