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_MEMBARRIER_SYNC_CORE 58 select ARCH_HAS_PMEM_API if X86_64 59 select ARCH_HAS_REFCOUNT 60 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 61 select ARCH_HAS_SET_MEMORY 62 select ARCH_HAS_SG_CHAIN 63 select ARCH_HAS_STRICT_KERNEL_RWX 64 select ARCH_HAS_STRICT_MODULE_RWX 65 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 66 select ARCH_HAS_UBSAN_SANITIZE_ALL 67 select ARCH_HAS_ZONE_DEVICE if X86_64 68 select ARCH_HAVE_NMI_SAFE_CMPXCHG 69 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 70 select ARCH_MIGHT_HAVE_PC_PARPORT 71 select ARCH_MIGHT_HAVE_PC_SERIO 72 select ARCH_SUPPORTS_ATOMIC_RMW 73 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 74 select ARCH_USE_BUILTIN_BSWAP 75 select ARCH_USE_QUEUED_RWLOCKS 76 select ARCH_USE_QUEUED_SPINLOCKS 77 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 78 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 79 select ARCH_WANTS_THP_SWAP if X86_64 80 select BUILDTIME_EXTABLE_SORT 81 select CLKEVT_I8253 82 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 83 select CLOCKSOURCE_WATCHDOG 84 select DCACHE_WORD_ACCESS 85 select DMA_DIRECT_OPS 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_X2APIC 397 bool "Support x2apic" 398 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 399 ---help--- 400 This enables x2apic support on CPUs that have this feature. 401 402 This allows 32-bit apic IDs (so it can support very large systems), 403 and accesses the local apic via MSRs not via mmio. 404 405 If you don't know what to do here, say N. 406 407config X86_MPPARSE 408 bool "Enable MPS table" if ACPI || SFI 409 default y 410 depends on X86_LOCAL_APIC 411 ---help--- 412 For old smp systems that do not have proper acpi support. Newer systems 413 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 414 415config GOLDFISH 416 def_bool y 417 depends on X86_GOLDFISH 418 419config RETPOLINE 420 bool "Avoid speculative indirect branches in kernel" 421 default y 422 select STACK_VALIDATION if HAVE_STACK_VALIDATION 423 help 424 Compile kernel with the retpoline compiler options to guard against 425 kernel-to-user data leaks by avoiding speculative indirect 426 branches. Requires a compiler with -mindirect-branch=thunk-extern 427 support for full protection. The kernel may run slower. 428 429 Without compiler support, at least indirect branches in assembler 430 code are eliminated. Since this includes the syscall entry path, 431 it is not entirely pointless. 432 433config INTEL_RDT 434 bool "Intel Resource Director Technology support" 435 default n 436 depends on X86 && CPU_SUP_INTEL 437 select KERNFS 438 help 439 Select to enable resource allocation and monitoring which are 440 sub-features of Intel Resource Director Technology(RDT). More 441 information about RDT can be found in the Intel x86 442 Architecture Software Developer Manual. 443 444 Say N if unsure. 445 446if X86_32 447config X86_BIGSMP 448 bool "Support for big SMP systems with more than 8 CPUs" 449 depends on SMP 450 ---help--- 451 This option is needed for the systems that have more than 8 CPUs 452 453config X86_EXTENDED_PLATFORM 454 bool "Support for extended (non-PC) x86 platforms" 455 default y 456 ---help--- 457 If you disable this option then the kernel will only support 458 standard PC platforms. (which covers the vast majority of 459 systems out there.) 460 461 If you enable this option then you'll be able to select support 462 for the following (non-PC) 32 bit x86 platforms: 463 Goldfish (Android emulator) 464 AMD Elan 465 RDC R-321x SoC 466 SGI 320/540 (Visual Workstation) 467 STA2X11-based (e.g. Northville) 468 Moorestown MID devices 469 470 If you have one of these systems, or if you want to build a 471 generic distribution kernel, say Y here - otherwise say N. 472endif 473 474if X86_64 475config X86_EXTENDED_PLATFORM 476 bool "Support for extended (non-PC) x86 platforms" 477 default y 478 ---help--- 479 If you disable this option then the kernel will only support 480 standard PC platforms. (which covers the vast majority of 481 systems out there.) 482 483 If you enable this option then you'll be able to select support 484 for the following (non-PC) 64 bit x86 platforms: 485 Numascale NumaChip 486 ScaleMP vSMP 487 SGI Ultraviolet 488 489 If you have one of these systems, or if you want to build a 490 generic distribution kernel, say Y here - otherwise say N. 491endif 492# This is an alphabetically sorted list of 64 bit extended platforms 493# Please maintain the alphabetic order if and when there are additions 494config X86_NUMACHIP 495 bool "Numascale NumaChip" 496 depends on X86_64 497 depends on X86_EXTENDED_PLATFORM 498 depends on NUMA 499 depends on SMP 500 depends on X86_X2APIC 501 depends on PCI_MMCONFIG 502 ---help--- 503 Adds support for Numascale NumaChip large-SMP systems. Needed to 504 enable more than ~168 cores. 505 If you don't have one of these, you should say N here. 506 507config X86_VSMP 508 bool "ScaleMP vSMP" 509 select HYPERVISOR_GUEST 510 select PARAVIRT 511 depends on X86_64 && PCI 512 depends on X86_EXTENDED_PLATFORM 513 depends on SMP 514 ---help--- 515 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 516 supposed to run on these EM64T-based machines. Only choose this option 517 if you have one of these machines. 518 519config X86_UV 520 bool "SGI Ultraviolet" 521 depends on X86_64 522 depends on X86_EXTENDED_PLATFORM 523 depends on NUMA 524 depends on EFI 525 depends on X86_X2APIC 526 depends on PCI 527 ---help--- 528 This option is needed in order to support SGI Ultraviolet systems. 529 If you don't have one of these, you should say N here. 530 531# Following is an alphabetically sorted list of 32 bit extended platforms 532# Please maintain the alphabetic order if and when there are additions 533 534config X86_GOLDFISH 535 bool "Goldfish (Virtual Platform)" 536 depends on X86_EXTENDED_PLATFORM 537 ---help--- 538 Enable support for the Goldfish virtual platform used primarily 539 for Android development. Unless you are building for the Android 540 Goldfish emulator say N here. 541 542config X86_INTEL_CE 543 bool "CE4100 TV platform" 544 depends on PCI 545 depends on PCI_GODIRECT 546 depends on X86_IO_APIC 547 depends on X86_32 548 depends on X86_EXTENDED_PLATFORM 549 select X86_REBOOTFIXUPS 550 select OF 551 select OF_EARLY_FLATTREE 552 ---help--- 553 Select for the Intel CE media processor (CE4100) SOC. 554 This option compiles in support for the CE4100 SOC for settop 555 boxes and media devices. 556 557config X86_INTEL_MID 558 bool "Intel MID platform support" 559 depends on X86_EXTENDED_PLATFORM 560 depends on X86_PLATFORM_DEVICES 561 depends on PCI 562 depends on X86_64 || (PCI_GOANY && X86_32) 563 depends on X86_IO_APIC 564 select SFI 565 select I2C 566 select DW_APB_TIMER 567 select APB_TIMER 568 select INTEL_SCU_IPC 569 select MFD_INTEL_MSIC 570 ---help--- 571 Select to build a kernel capable of supporting Intel MID (Mobile 572 Internet Device) platform systems which do not have the PCI legacy 573 interfaces. If you are building for a PC class system say N here. 574 575 Intel MID platforms are based on an Intel processor and chipset which 576 consume less power than most of the x86 derivatives. 577 578config X86_INTEL_QUARK 579 bool "Intel Quark platform support" 580 depends on X86_32 581 depends on X86_EXTENDED_PLATFORM 582 depends on X86_PLATFORM_DEVICES 583 depends on X86_TSC 584 depends on PCI 585 depends on PCI_GOANY 586 depends on X86_IO_APIC 587 select IOSF_MBI 588 select INTEL_IMR 589 select COMMON_CLK 590 ---help--- 591 Select to include support for Quark X1000 SoC. 592 Say Y here if you have a Quark based system such as the Arduino 593 compatible Intel Galileo. 594 595config X86_INTEL_LPSS 596 bool "Intel Low Power Subsystem Support" 597 depends on X86 && ACPI 598 select COMMON_CLK 599 select PINCTRL 600 select IOSF_MBI 601 ---help--- 602 Select to build support for Intel Low Power Subsystem such as 603 found on Intel Lynxpoint PCH. Selecting this option enables 604 things like clock tree (common clock framework) and pincontrol 605 which are needed by the LPSS peripheral drivers. 606 607config X86_AMD_PLATFORM_DEVICE 608 bool "AMD ACPI2Platform devices support" 609 depends on ACPI 610 select COMMON_CLK 611 select PINCTRL 612 ---help--- 613 Select to interpret AMD specific ACPI device to platform device 614 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 615 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 616 implemented under PINCTRL subsystem. 617 618config IOSF_MBI 619 tristate "Intel SoC IOSF Sideband support for SoC platforms" 620 depends on PCI 621 ---help--- 622 This option enables sideband register access support for Intel SoC 623 platforms. On these platforms the IOSF sideband is used in lieu of 624 MSR's for some register accesses, mostly but not limited to thermal 625 and power. Drivers may query the availability of this device to 626 determine if they need the sideband in order to work on these 627 platforms. The sideband is available on the following SoC products. 628 This list is not meant to be exclusive. 629 - BayTrail 630 - Braswell 631 - Quark 632 633 You should say Y if you are running a kernel on one of these SoC's. 634 635config IOSF_MBI_DEBUG 636 bool "Enable IOSF sideband access through debugfs" 637 depends on IOSF_MBI && DEBUG_FS 638 ---help--- 639 Select this option to expose the IOSF sideband access registers (MCR, 640 MDR, MCRX) through debugfs to write and read register information from 641 different units on the SoC. This is most useful for obtaining device 642 state information for debug and analysis. As this is a general access 643 mechanism, users of this option would have specific knowledge of the 644 device they want to access. 645 646 If you don't require the option or are in doubt, say N. 647 648config X86_RDC321X 649 bool "RDC R-321x SoC" 650 depends on X86_32 651 depends on X86_EXTENDED_PLATFORM 652 select M486 653 select X86_REBOOTFIXUPS 654 ---help--- 655 This option is needed for RDC R-321x system-on-chip, also known 656 as R-8610-(G). 657 If you don't have one of these chips, you should say N here. 658 659config X86_32_NON_STANDARD 660 bool "Support non-standard 32-bit SMP architectures" 661 depends on X86_32 && SMP 662 depends on X86_EXTENDED_PLATFORM 663 ---help--- 664 This option compiles in the bigsmp and STA2X11 default 665 subarchitectures. It is intended for a generic binary 666 kernel. If you select them all, kernel will probe it one by 667 one and will fallback to default. 668 669# Alphabetically sorted list of Non standard 32 bit platforms 670 671config X86_SUPPORTS_MEMORY_FAILURE 672 def_bool y 673 # MCE code calls memory_failure(): 674 depends on X86_MCE 675 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 676 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 677 depends on X86_64 || !SPARSEMEM 678 select ARCH_SUPPORTS_MEMORY_FAILURE 679 680config STA2X11 681 bool "STA2X11 Companion Chip Support" 682 depends on X86_32_NON_STANDARD && PCI 683 select ARCH_HAS_PHYS_TO_DMA 684 select X86_DEV_DMA_OPS 685 select X86_DMA_REMAP 686 select SWIOTLB 687 select MFD_STA2X11 688 select GPIOLIB 689 default n 690 ---help--- 691 This adds support for boards based on the STA2X11 IO-Hub, 692 a.k.a. "ConneXt". The chip is used in place of the standard 693 PC chipset, so all "standard" peripherals are missing. If this 694 option is selected the kernel will still be able to boot on 695 standard PC machines. 696 697config X86_32_IRIS 698 tristate "Eurobraille/Iris poweroff module" 699 depends on X86_32 700 ---help--- 701 The Iris machines from EuroBraille do not have APM or ACPI support 702 to shut themselves down properly. A special I/O sequence is 703 needed to do so, which is what this module does at 704 kernel shutdown. 705 706 This is only for Iris machines from EuroBraille. 707 708 If unused, say N. 709 710config SCHED_OMIT_FRAME_POINTER 711 def_bool y 712 prompt "Single-depth WCHAN output" 713 depends on X86 714 ---help--- 715 Calculate simpler /proc/<PID>/wchan values. If this option 716 is disabled then wchan values will recurse back to the 717 caller function. This provides more accurate wchan values, 718 at the expense of slightly more scheduling overhead. 719 720 If in doubt, say "Y". 721 722menuconfig HYPERVISOR_GUEST 723 bool "Linux guest support" 724 ---help--- 725 Say Y here to enable options for running Linux under various hyper- 726 visors. This option enables basic hypervisor detection and platform 727 setup. 728 729 If you say N, all options in this submenu will be skipped and 730 disabled, and Linux guest support won't be built in. 731 732if HYPERVISOR_GUEST 733 734config PARAVIRT 735 bool "Enable paravirtualization code" 736 ---help--- 737 This changes the kernel so it can modify itself when it is run 738 under a hypervisor, potentially improving performance significantly 739 over full virtualization. However, when run without a hypervisor 740 the kernel is theoretically slower and slightly larger. 741 742config PARAVIRT_DEBUG 743 bool "paravirt-ops debugging" 744 depends on PARAVIRT && DEBUG_KERNEL 745 ---help--- 746 Enable to debug paravirt_ops internals. Specifically, BUG if 747 a paravirt_op is missing when it is called. 748 749config PARAVIRT_SPINLOCKS 750 bool "Paravirtualization layer for spinlocks" 751 depends on PARAVIRT && SMP 752 ---help--- 753 Paravirtualized spinlocks allow a pvops backend to replace the 754 spinlock implementation with something virtualization-friendly 755 (for example, block the virtual CPU rather than spinning). 756 757 It has a minimal impact on native kernels and gives a nice performance 758 benefit on paravirtualized KVM / Xen kernels. 759 760 If you are unsure how to answer this question, answer Y. 761 762config QUEUED_LOCK_STAT 763 bool "Paravirt queued spinlock statistics" 764 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 765 ---help--- 766 Enable the collection of statistical data on the slowpath 767 behavior of paravirtualized queued spinlocks and report 768 them on debugfs. 769 770source "arch/x86/xen/Kconfig" 771 772config KVM_GUEST 773 bool "KVM Guest support (including kvmclock)" 774 depends on PARAVIRT 775 select PARAVIRT_CLOCK 776 default y 777 ---help--- 778 This option enables various optimizations for running under the KVM 779 hypervisor. It includes a paravirtualized clock, so that instead 780 of relying on a PIT (or probably other) emulation by the 781 underlying device model, the host provides the guest with 782 timing infrastructure such as time of day, and system time 783 784config KVM_DEBUG_FS 785 bool "Enable debug information for KVM Guests in debugfs" 786 depends on KVM_GUEST && DEBUG_FS 787 default n 788 ---help--- 789 This option enables collection of various statistics for KVM guest. 790 Statistics are displayed in debugfs filesystem. Enabling this option 791 may incur significant overhead. 792 793config PARAVIRT_TIME_ACCOUNTING 794 bool "Paravirtual steal time accounting" 795 depends on PARAVIRT 796 default n 797 ---help--- 798 Select this option to enable fine granularity task steal time 799 accounting. Time spent executing other tasks in parallel with 800 the current vCPU is discounted from the vCPU power. To account for 801 that, there can be a small performance impact. 802 803 If in doubt, say N here. 804 805config PARAVIRT_CLOCK 806 bool 807 808config JAILHOUSE_GUEST 809 bool "Jailhouse non-root cell support" 810 depends on X86_64 && PCI 811 select X86_PM_TIMER 812 ---help--- 813 This option allows to run Linux as guest in a Jailhouse non-root 814 cell. You can leave this option disabled if you only want to start 815 Jailhouse and run Linux afterwards in the root cell. 816 817endif #HYPERVISOR_GUEST 818 819config NO_BOOTMEM 820 def_bool y 821 822source "arch/x86/Kconfig.cpu" 823 824config HPET_TIMER 825 def_bool X86_64 826 prompt "HPET Timer Support" if X86_32 827 ---help--- 828 Use the IA-PC HPET (High Precision Event Timer) to manage 829 time in preference to the PIT and RTC, if a HPET is 830 present. 831 HPET is the next generation timer replacing legacy 8254s. 832 The HPET provides a stable time base on SMP 833 systems, unlike the TSC, but it is more expensive to access, 834 as it is off-chip. The interface used is documented 835 in the HPET spec, revision 1. 836 837 You can safely choose Y here. However, HPET will only be 838 activated if the platform and the BIOS support this feature. 839 Otherwise the 8254 will be used for timing services. 840 841 Choose N to continue using the legacy 8254 timer. 842 843config HPET_EMULATE_RTC 844 def_bool y 845 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 846 847config APB_TIMER 848 def_bool y if X86_INTEL_MID 849 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 850 select DW_APB_TIMER 851 depends on X86_INTEL_MID && SFI 852 help 853 APB timer is the replacement for 8254, HPET on X86 MID platforms. 854 The APBT provides a stable time base on SMP 855 systems, unlike the TSC, but it is more expensive to access, 856 as it is off-chip. APB timers are always running regardless of CPU 857 C states, they are used as per CPU clockevent device when possible. 858 859# Mark as expert because too many people got it wrong. 860# The code disables itself when not needed. 861config DMI 862 default y 863 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 864 bool "Enable DMI scanning" if EXPERT 865 ---help--- 866 Enabled scanning of DMI to identify machine quirks. Say Y 867 here unless you have verified that your setup is not 868 affected by entries in the DMI blacklist. Required by PNP 869 BIOS code. 870 871config GART_IOMMU 872 bool "Old AMD GART IOMMU support" 873 select SWIOTLB 874 depends on X86_64 && PCI && AMD_NB 875 ---help--- 876 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 877 GART based hardware IOMMUs. 878 879 The GART supports full DMA access for devices with 32-bit access 880 limitations, on systems with more than 3 GB. This is usually needed 881 for USB, sound, many IDE/SATA chipsets and some other devices. 882 883 Newer systems typically have a modern AMD IOMMU, supported via 884 the CONFIG_AMD_IOMMU=y config option. 885 886 In normal configurations this driver is only active when needed: 887 there's more than 3 GB of memory and the system contains a 888 32-bit limited device. 889 890 If unsure, say Y. 891 892config CALGARY_IOMMU 893 bool "IBM Calgary IOMMU support" 894 select SWIOTLB 895 depends on X86_64 && PCI 896 ---help--- 897 Support for hardware IOMMUs in IBM's xSeries x366 and x460 898 systems. Needed to run systems with more than 3GB of memory 899 properly with 32-bit PCI devices that do not support DAC 900 (Double Address Cycle). Calgary also supports bus level 901 isolation, where all DMAs pass through the IOMMU. This 902 prevents them from going anywhere except their intended 903 destination. This catches hard-to-find kernel bugs and 904 mis-behaving drivers and devices that do not use the DMA-API 905 properly to set up their DMA buffers. The IOMMU can be 906 turned off at boot time with the iommu=off parameter. 907 Normally the kernel will make the right choice by itself. 908 If unsure, say Y. 909 910config CALGARY_IOMMU_ENABLED_BY_DEFAULT 911 def_bool y 912 prompt "Should Calgary be enabled by default?" 913 depends on CALGARY_IOMMU 914 ---help--- 915 Should Calgary be enabled by default? if you choose 'y', Calgary 916 will be used (if it exists). If you choose 'n', Calgary will not be 917 used even if it exists. If you choose 'n' and would like to use 918 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 919 If unsure, say Y. 920 921# need this always selected by IOMMU for the VIA workaround 922config SWIOTLB 923 def_bool y if X86_64 924 ---help--- 925 Support for software bounce buffers used on x86-64 systems 926 which don't have a hardware IOMMU. Using this PCI devices 927 which can only access 32-bits of memory can be used on systems 928 with more than 3 GB of memory. 929 If unsure, say Y. 930 931config IOMMU_HELPER 932 def_bool y 933 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 934 935config MAXSMP 936 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 937 depends on X86_64 && SMP && DEBUG_KERNEL 938 select CPUMASK_OFFSTACK 939 ---help--- 940 Enable maximum number of CPUS and NUMA Nodes for this architecture. 941 If unsure, say N. 942 943# 944# The maximum number of CPUs supported: 945# 946# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 947# and which can be configured interactively in the 948# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 949# 950# The ranges are different on 32-bit and 64-bit kernels, depending on 951# hardware capabilities and scalability features of the kernel. 952# 953# ( If MAXSMP is enabled we just use the highest possible value and disable 954# interactive configuration. ) 955# 956 957config NR_CPUS_RANGE_BEGIN 958 int 959 default NR_CPUS_RANGE_END if MAXSMP 960 default 1 if !SMP 961 default 2 962 963config NR_CPUS_RANGE_END 964 int 965 depends on X86_32 966 default 64 if SMP && X86_BIGSMP 967 default 8 if SMP && !X86_BIGSMP 968 default 1 if !SMP 969 970config NR_CPUS_RANGE_END 971 int 972 depends on X86_64 973 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 974 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 975 default 1 if !SMP 976 977config NR_CPUS_DEFAULT 978 int 979 depends on X86_32 980 default 32 if X86_BIGSMP 981 default 8 if SMP 982 default 1 if !SMP 983 984config NR_CPUS_DEFAULT 985 int 986 depends on X86_64 987 default 8192 if MAXSMP 988 default 64 if SMP 989 default 1 if !SMP 990 991config NR_CPUS 992 int "Maximum number of CPUs" if SMP && !MAXSMP 993 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 994 default NR_CPUS_DEFAULT 995 ---help--- 996 This allows you to specify the maximum number of CPUs which this 997 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 998 supported value is 8192, otherwise the maximum value is 512. The 999 minimum value which makes sense is 2. 1000 1001 This is purely to save memory: each supported CPU adds about 8KB 1002 to the kernel image. 1003 1004config SCHED_SMT 1005 bool "SMT (Hyperthreading) scheduler support" 1006 depends on SMP 1007 ---help--- 1008 SMT scheduler support improves the CPU scheduler's decision making 1009 when dealing with Intel Pentium 4 chips with HyperThreading at a 1010 cost of slightly increased overhead in some places. If unsure say 1011 N here. 1012 1013config SCHED_MC 1014 def_bool y 1015 prompt "Multi-core scheduler support" 1016 depends on SMP 1017 ---help--- 1018 Multi-core scheduler support improves the CPU scheduler's decision 1019 making when dealing with multi-core CPU chips at a cost of slightly 1020 increased overhead in some places. If unsure say N here. 1021 1022config SCHED_MC_PRIO 1023 bool "CPU core priorities scheduler support" 1024 depends on SCHED_MC && CPU_SUP_INTEL 1025 select X86_INTEL_PSTATE 1026 select CPU_FREQ 1027 default y 1028 ---help--- 1029 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1030 core ordering determined at manufacturing time, which allows 1031 certain cores to reach higher turbo frequencies (when running 1032 single threaded workloads) than others. 1033 1034 Enabling this kernel feature teaches the scheduler about 1035 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1036 scheduler's CPU selection logic accordingly, so that higher 1037 overall system performance can be achieved. 1038 1039 This feature will have no effect on CPUs without this feature. 1040 1041 If unsure say Y here. 1042 1043source "kernel/Kconfig.preempt" 1044 1045config UP_LATE_INIT 1046 def_bool y 1047 depends on !SMP && X86_LOCAL_APIC 1048 1049config X86_UP_APIC 1050 bool "Local APIC support on uniprocessors" if !PCI_MSI 1051 default PCI_MSI 1052 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1053 ---help--- 1054 A local APIC (Advanced Programmable Interrupt Controller) is an 1055 integrated interrupt controller in the CPU. If you have a single-CPU 1056 system which has a processor with a local APIC, you can say Y here to 1057 enable and use it. If you say Y here even though your machine doesn't 1058 have a local APIC, then the kernel will still run with no slowdown at 1059 all. The local APIC supports CPU-generated self-interrupts (timer, 1060 performance counters), and the NMI watchdog which detects hard 1061 lockups. 1062 1063config X86_UP_IOAPIC 1064 bool "IO-APIC support on uniprocessors" 1065 depends on X86_UP_APIC 1066 ---help--- 1067 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1068 SMP-capable replacement for PC-style interrupt controllers. Most 1069 SMP systems and many recent uniprocessor systems have one. 1070 1071 If you have a single-CPU system with an IO-APIC, you can say Y here 1072 to use it. If you say Y here even though your machine doesn't have 1073 an IO-APIC, then the kernel will still run with no slowdown at all. 1074 1075config X86_LOCAL_APIC 1076 def_bool y 1077 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1078 select IRQ_DOMAIN_HIERARCHY 1079 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1080 1081config X86_IO_APIC 1082 def_bool y 1083 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1084 1085config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1086 bool "Reroute for broken boot IRQs" 1087 depends on X86_IO_APIC 1088 ---help--- 1089 This option enables a workaround that fixes a source of 1090 spurious interrupts. This is recommended when threaded 1091 interrupt handling is used on systems where the generation of 1092 superfluous "boot interrupts" cannot be disabled. 1093 1094 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1095 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1096 kernel does during interrupt handling). On chipsets where this 1097 boot IRQ generation cannot be disabled, this workaround keeps 1098 the original IRQ line masked so that only the equivalent "boot 1099 IRQ" is delivered to the CPUs. The workaround also tells the 1100 kernel to set up the IRQ handler on the boot IRQ line. In this 1101 way only one interrupt is delivered to the kernel. Otherwise 1102 the spurious second interrupt may cause the kernel to bring 1103 down (vital) interrupt lines. 1104 1105 Only affects "broken" chipsets. Interrupt sharing may be 1106 increased on these systems. 1107 1108config X86_MCE 1109 bool "Machine Check / overheating reporting" 1110 select GENERIC_ALLOCATOR 1111 default y 1112 ---help--- 1113 Machine Check support allows the processor to notify the 1114 kernel if it detects a problem (e.g. overheating, data corruption). 1115 The action the kernel takes depends on the severity of the problem, 1116 ranging from warning messages to halting the machine. 1117 1118config X86_MCELOG_LEGACY 1119 bool "Support for deprecated /dev/mcelog character device" 1120 depends on X86_MCE 1121 ---help--- 1122 Enable support for /dev/mcelog which is needed by the old mcelog 1123 userspace logging daemon. Consider switching to the new generation 1124 rasdaemon solution. 1125 1126config X86_MCE_INTEL 1127 def_bool y 1128 prompt "Intel MCE features" 1129 depends on X86_MCE && X86_LOCAL_APIC 1130 ---help--- 1131 Additional support for intel specific MCE features such as 1132 the thermal monitor. 1133 1134config X86_MCE_AMD 1135 def_bool y 1136 prompt "AMD MCE features" 1137 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1138 ---help--- 1139 Additional support for AMD specific MCE features such as 1140 the DRAM Error Threshold. 1141 1142config X86_ANCIENT_MCE 1143 bool "Support for old Pentium 5 / WinChip machine checks" 1144 depends on X86_32 && X86_MCE 1145 ---help--- 1146 Include support for machine check handling on old Pentium 5 or WinChip 1147 systems. These typically need to be enabled explicitly on the command 1148 line. 1149 1150config X86_MCE_THRESHOLD 1151 depends on X86_MCE_AMD || X86_MCE_INTEL 1152 def_bool y 1153 1154config X86_MCE_INJECT 1155 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1156 tristate "Machine check injector support" 1157 ---help--- 1158 Provide support for injecting machine checks for testing purposes. 1159 If you don't know what a machine check is and you don't do kernel 1160 QA it is safe to say n. 1161 1162config X86_THERMAL_VECTOR 1163 def_bool y 1164 depends on X86_MCE_INTEL 1165 1166source "arch/x86/events/Kconfig" 1167 1168config X86_LEGACY_VM86 1169 bool "Legacy VM86 support" 1170 default n 1171 depends on X86_32 1172 ---help--- 1173 This option allows user programs to put the CPU into V8086 1174 mode, which is an 80286-era approximation of 16-bit real mode. 1175 1176 Some very old versions of X and/or vbetool require this option 1177 for user mode setting. Similarly, DOSEMU will use it if 1178 available to accelerate real mode DOS programs. However, any 1179 recent version of DOSEMU, X, or vbetool should be fully 1180 functional even without kernel VM86 support, as they will all 1181 fall back to software emulation. Nevertheless, if you are using 1182 a 16-bit DOS program where 16-bit performance matters, vm86 1183 mode might be faster than emulation and you might want to 1184 enable this option. 1185 1186 Note that any app that works on a 64-bit kernel is unlikely to 1187 need this option, as 64-bit kernels don't, and can't, support 1188 V8086 mode. This option is also unrelated to 16-bit protected 1189 mode and is not needed to run most 16-bit programs under Wine. 1190 1191 Enabling this option increases the complexity of the kernel 1192 and slows down exception handling a tiny bit. 1193 1194 If unsure, say N here. 1195 1196config VM86 1197 bool 1198 default X86_LEGACY_VM86 1199 1200config X86_16BIT 1201 bool "Enable support for 16-bit segments" if EXPERT 1202 default y 1203 depends on MODIFY_LDT_SYSCALL 1204 ---help--- 1205 This option is required by programs like Wine to run 16-bit 1206 protected mode legacy code on x86 processors. Disabling 1207 this option saves about 300 bytes on i386, or around 6K text 1208 plus 16K runtime memory on x86-64, 1209 1210config X86_ESPFIX32 1211 def_bool y 1212 depends on X86_16BIT && X86_32 1213 1214config X86_ESPFIX64 1215 def_bool y 1216 depends on X86_16BIT && X86_64 1217 1218config X86_VSYSCALL_EMULATION 1219 bool "Enable vsyscall emulation" if EXPERT 1220 default y 1221 depends on X86_64 1222 ---help--- 1223 This enables emulation of the legacy vsyscall page. Disabling 1224 it is roughly equivalent to booting with vsyscall=none, except 1225 that it will also disable the helpful warning if a program 1226 tries to use a vsyscall. With this option set to N, offending 1227 programs will just segfault, citing addresses of the form 1228 0xffffffffff600?00. 1229 1230 This option is required by many programs built before 2013, and 1231 care should be used even with newer programs if set to N. 1232 1233 Disabling this option saves about 7K of kernel size and 1234 possibly 4K of additional runtime pagetable memory. 1235 1236config TOSHIBA 1237 tristate "Toshiba Laptop support" 1238 depends on X86_32 1239 ---help--- 1240 This adds a driver to safely access the System Management Mode of 1241 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1242 not work on models with a Phoenix BIOS. The System Management Mode 1243 is used to set the BIOS and power saving options on Toshiba portables. 1244 1245 For information on utilities to make use of this driver see the 1246 Toshiba Linux utilities web site at: 1247 <http://www.buzzard.org.uk/toshiba/>. 1248 1249 Say Y if you intend to run this kernel on a Toshiba portable. 1250 Say N otherwise. 1251 1252config I8K 1253 tristate "Dell i8k legacy laptop support" 1254 select HWMON 1255 select SENSORS_DELL_SMM 1256 ---help--- 1257 This option enables legacy /proc/i8k userspace interface in hwmon 1258 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1259 temperature and allows controlling fan speeds of Dell laptops via 1260 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1261 it reports also power and hotkey status. For fan speed control is 1262 needed userspace package i8kutils. 1263 1264 Say Y if you intend to run this kernel on old Dell laptops or want to 1265 use userspace package i8kutils. 1266 Say N otherwise. 1267 1268config X86_REBOOTFIXUPS 1269 bool "Enable X86 board specific fixups for reboot" 1270 depends on X86_32 1271 ---help--- 1272 This enables chipset and/or board specific fixups to be done 1273 in order to get reboot to work correctly. This is only needed on 1274 some combinations of hardware and BIOS. The symptom, for which 1275 this config is intended, is when reboot ends with a stalled/hung 1276 system. 1277 1278 Currently, the only fixup is for the Geode machines using 1279 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1280 1281 Say Y if you want to enable the fixup. Currently, it's safe to 1282 enable this option even if you don't need it. 1283 Say N otherwise. 1284 1285config MICROCODE 1286 bool "CPU microcode loading support" 1287 default y 1288 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1289 select FW_LOADER 1290 ---help--- 1291 If you say Y here, you will be able to update the microcode on 1292 Intel and AMD processors. The Intel support is for the IA32 family, 1293 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1294 AMD support is for families 0x10 and later. You will obviously need 1295 the actual microcode binary data itself which is not shipped with 1296 the Linux kernel. 1297 1298 The preferred method to load microcode from a detached initrd is described 1299 in Documentation/x86/microcode.txt. For that you need to enable 1300 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1301 initrd for microcode blobs. 1302 1303 In addition, you can build the microcode into the kernel. For that you 1304 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1305 config option. 1306 1307config MICROCODE_INTEL 1308 bool "Intel microcode loading support" 1309 depends on MICROCODE 1310 default MICROCODE 1311 select FW_LOADER 1312 ---help--- 1313 This options enables microcode patch loading support for Intel 1314 processors. 1315 1316 For the current Intel microcode data package go to 1317 <https://downloadcenter.intel.com> and search for 1318 'Linux Processor Microcode Data File'. 1319 1320config MICROCODE_AMD 1321 bool "AMD microcode loading support" 1322 depends on MICROCODE 1323 select FW_LOADER 1324 ---help--- 1325 If you select this option, microcode patch loading support for AMD 1326 processors will be enabled. 1327 1328config MICROCODE_OLD_INTERFACE 1329 def_bool y 1330 depends on MICROCODE 1331 1332config X86_MSR 1333 tristate "/dev/cpu/*/msr - Model-specific register support" 1334 ---help--- 1335 This device gives privileged processes access to the x86 1336 Model-Specific Registers (MSRs). It is a character device with 1337 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1338 MSR accesses are directed to a specific CPU on multi-processor 1339 systems. 1340 1341config X86_CPUID 1342 tristate "/dev/cpu/*/cpuid - CPU information support" 1343 ---help--- 1344 This device gives processes access to the x86 CPUID instruction to 1345 be executed on a specific processor. It is a character device 1346 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1347 /dev/cpu/31/cpuid. 1348 1349choice 1350 prompt "High Memory Support" 1351 default HIGHMEM4G 1352 depends on X86_32 1353 1354config NOHIGHMEM 1355 bool "off" 1356 ---help--- 1357 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1358 However, the address space of 32-bit x86 processors is only 4 1359 Gigabytes large. That means that, if you have a large amount of 1360 physical memory, not all of it can be "permanently mapped" by the 1361 kernel. The physical memory that's not permanently mapped is called 1362 "high memory". 1363 1364 If you are compiling a kernel which will never run on a machine with 1365 more than 1 Gigabyte total physical RAM, answer "off" here (default 1366 choice and suitable for most users). This will result in a "3GB/1GB" 1367 split: 3GB are mapped so that each process sees a 3GB virtual memory 1368 space and the remaining part of the 4GB virtual memory space is used 1369 by the kernel to permanently map as much physical memory as 1370 possible. 1371 1372 If the machine has between 1 and 4 Gigabytes physical RAM, then 1373 answer "4GB" here. 1374 1375 If more than 4 Gigabytes is used then answer "64GB" here. This 1376 selection turns Intel PAE (Physical Address Extension) mode on. 1377 PAE implements 3-level paging on IA32 processors. PAE is fully 1378 supported by Linux, PAE mode is implemented on all recent Intel 1379 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1380 then the kernel will not boot on CPUs that don't support PAE! 1381 1382 The actual amount of total physical memory will either be 1383 auto detected or can be forced by using a kernel command line option 1384 such as "mem=256M". (Try "man bootparam" or see the documentation of 1385 your boot loader (lilo or loadlin) about how to pass options to the 1386 kernel at boot time.) 1387 1388 If unsure, say "off". 1389 1390config HIGHMEM4G 1391 bool "4GB" 1392 ---help--- 1393 Select this if you have a 32-bit processor and between 1 and 4 1394 gigabytes of physical RAM. 1395 1396config HIGHMEM64G 1397 bool "64GB" 1398 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1399 select X86_PAE 1400 ---help--- 1401 Select this if you have a 32-bit processor and more than 4 1402 gigabytes of physical RAM. 1403 1404endchoice 1405 1406choice 1407 prompt "Memory split" if EXPERT 1408 default VMSPLIT_3G 1409 depends on X86_32 1410 ---help--- 1411 Select the desired split between kernel and user memory. 1412 1413 If the address range available to the kernel is less than the 1414 physical memory installed, the remaining memory will be available 1415 as "high memory". Accessing high memory is a little more costly 1416 than low memory, as it needs to be mapped into the kernel first. 1417 Note that increasing the kernel address space limits the range 1418 available to user programs, making the address space there 1419 tighter. Selecting anything other than the default 3G/1G split 1420 will also likely make your kernel incompatible with binary-only 1421 kernel modules. 1422 1423 If you are not absolutely sure what you are doing, leave this 1424 option alone! 1425 1426 config VMSPLIT_3G 1427 bool "3G/1G user/kernel split" 1428 config VMSPLIT_3G_OPT 1429 depends on !X86_PAE 1430 bool "3G/1G user/kernel split (for full 1G low memory)" 1431 config VMSPLIT_2G 1432 bool "2G/2G user/kernel split" 1433 config VMSPLIT_2G_OPT 1434 depends on !X86_PAE 1435 bool "2G/2G user/kernel split (for full 2G low memory)" 1436 config VMSPLIT_1G 1437 bool "1G/3G user/kernel split" 1438endchoice 1439 1440config PAGE_OFFSET 1441 hex 1442 default 0xB0000000 if VMSPLIT_3G_OPT 1443 default 0x80000000 if VMSPLIT_2G 1444 default 0x78000000 if VMSPLIT_2G_OPT 1445 default 0x40000000 if VMSPLIT_1G 1446 default 0xC0000000 1447 depends on X86_32 1448 1449config HIGHMEM 1450 def_bool y 1451 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1452 1453config X86_PAE 1454 bool "PAE (Physical Address Extension) Support" 1455 depends on X86_32 && !HIGHMEM4G 1456 select SWIOTLB 1457 ---help--- 1458 PAE is required for NX support, and furthermore enables 1459 larger swapspace support for non-overcommit purposes. It 1460 has the cost of more pagetable lookup overhead, and also 1461 consumes more pagetable space per process. 1462 1463config X86_5LEVEL 1464 bool "Enable 5-level page tables support" 1465 select DYNAMIC_MEMORY_LAYOUT 1466 select SPARSEMEM_VMEMMAP 1467 depends on X86_64 1468 ---help--- 1469 5-level paging enables access to larger address space: 1470 upto 128 PiB of virtual address space and 4 PiB of 1471 physical address space. 1472 1473 It will be supported by future Intel CPUs. 1474 1475 A kernel with the option enabled can be booted on machines that 1476 support 4- or 5-level paging. 1477 1478 See Documentation/x86/x86_64/5level-paging.txt for more 1479 information. 1480 1481 Say N if unsure. 1482 1483config ARCH_PHYS_ADDR_T_64BIT 1484 def_bool y 1485 depends on X86_64 || X86_PAE 1486 1487config ARCH_DMA_ADDR_T_64BIT 1488 def_bool y 1489 depends on X86_64 || HIGHMEM64G 1490 1491config X86_DIRECT_GBPAGES 1492 def_bool y 1493 depends on X86_64 && !DEBUG_PAGEALLOC 1494 ---help--- 1495 Certain kernel features effectively disable kernel 1496 linear 1 GB mappings (even if the CPU otherwise 1497 supports them), so don't confuse the user by printing 1498 that we have them enabled. 1499 1500config ARCH_HAS_MEM_ENCRYPT 1501 def_bool y 1502 1503config AMD_MEM_ENCRYPT 1504 bool "AMD Secure Memory Encryption (SME) support" 1505 depends on X86_64 && CPU_SUP_AMD 1506 ---help--- 1507 Say yes to enable support for the encryption of system memory. 1508 This requires an AMD processor that supports Secure Memory 1509 Encryption (SME). 1510 1511config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1512 bool "Activate AMD Secure Memory Encryption (SME) by default" 1513 default y 1514 depends on AMD_MEM_ENCRYPT 1515 ---help--- 1516 Say yes to have system memory encrypted by default if running on 1517 an AMD processor that supports Secure Memory Encryption (SME). 1518 1519 If set to Y, then the encryption of system memory can be 1520 deactivated with the mem_encrypt=off command line option. 1521 1522 If set to N, then the encryption of system memory can be 1523 activated with the mem_encrypt=on command line option. 1524 1525config ARCH_USE_MEMREMAP_PROT 1526 def_bool y 1527 depends on AMD_MEM_ENCRYPT 1528 1529# Common NUMA Features 1530config NUMA 1531 bool "Numa Memory Allocation and Scheduler Support" 1532 depends on SMP 1533 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1534 default y if X86_BIGSMP 1535 ---help--- 1536 Enable NUMA (Non Uniform Memory Access) support. 1537 1538 The kernel will try to allocate memory used by a CPU on the 1539 local memory controller of the CPU and add some more 1540 NUMA awareness to the kernel. 1541 1542 For 64-bit this is recommended if the system is Intel Core i7 1543 (or later), AMD Opteron, or EM64T NUMA. 1544 1545 For 32-bit this is only needed if you boot a 32-bit 1546 kernel on a 64-bit NUMA platform. 1547 1548 Otherwise, you should say N. 1549 1550config AMD_NUMA 1551 def_bool y 1552 prompt "Old style AMD Opteron NUMA detection" 1553 depends on X86_64 && NUMA && PCI 1554 ---help--- 1555 Enable AMD NUMA node topology detection. You should say Y here if 1556 you have a multi processor AMD system. This uses an old method to 1557 read the NUMA configuration directly from the builtin Northbridge 1558 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1559 which also takes priority if both are compiled in. 1560 1561config X86_64_ACPI_NUMA 1562 def_bool y 1563 prompt "ACPI NUMA detection" 1564 depends on X86_64 && NUMA && ACPI && PCI 1565 select ACPI_NUMA 1566 ---help--- 1567 Enable ACPI SRAT based node topology detection. 1568 1569# Some NUMA nodes have memory ranges that span 1570# other nodes. Even though a pfn is valid and 1571# between a node's start and end pfns, it may not 1572# reside on that node. See memmap_init_zone() 1573# for details. 1574config NODES_SPAN_OTHER_NODES 1575 def_bool y 1576 depends on X86_64_ACPI_NUMA 1577 1578config NUMA_EMU 1579 bool "NUMA emulation" 1580 depends on NUMA 1581 ---help--- 1582 Enable NUMA emulation. A flat machine will be split 1583 into virtual nodes when booted with "numa=fake=N", where N is the 1584 number of nodes. This is only useful for debugging. 1585 1586config NODES_SHIFT 1587 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1588 range 1 10 1589 default "10" if MAXSMP 1590 default "6" if X86_64 1591 default "3" 1592 depends on NEED_MULTIPLE_NODES 1593 ---help--- 1594 Specify the maximum number of NUMA Nodes available on the target 1595 system. Increases memory reserved to accommodate various tables. 1596 1597config ARCH_HAVE_MEMORY_PRESENT 1598 def_bool y 1599 depends on X86_32 && DISCONTIGMEM 1600 1601config ARCH_FLATMEM_ENABLE 1602 def_bool y 1603 depends on X86_32 && !NUMA 1604 1605config ARCH_DISCONTIGMEM_ENABLE 1606 def_bool y 1607 depends on NUMA && X86_32 1608 1609config ARCH_DISCONTIGMEM_DEFAULT 1610 def_bool y 1611 depends on NUMA && X86_32 1612 1613config ARCH_SPARSEMEM_ENABLE 1614 def_bool y 1615 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1616 select SPARSEMEM_STATIC if X86_32 1617 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1618 1619config ARCH_SPARSEMEM_DEFAULT 1620 def_bool y 1621 depends on X86_64 1622 1623config ARCH_SELECT_MEMORY_MODEL 1624 def_bool y 1625 depends on ARCH_SPARSEMEM_ENABLE 1626 1627config ARCH_MEMORY_PROBE 1628 bool "Enable sysfs memory/probe interface" 1629 depends on X86_64 && MEMORY_HOTPLUG 1630 help 1631 This option enables a sysfs memory/probe interface for testing. 1632 See Documentation/memory-hotplug.txt for more information. 1633 If you are unsure how to answer this question, answer N. 1634 1635config ARCH_PROC_KCORE_TEXT 1636 def_bool y 1637 depends on X86_64 && PROC_KCORE 1638 1639config ILLEGAL_POINTER_VALUE 1640 hex 1641 default 0 if X86_32 1642 default 0xdead000000000000 if X86_64 1643 1644source "mm/Kconfig" 1645 1646config X86_PMEM_LEGACY_DEVICE 1647 bool 1648 1649config X86_PMEM_LEGACY 1650 tristate "Support non-standard NVDIMMs and ADR protected memory" 1651 depends on PHYS_ADDR_T_64BIT 1652 depends on BLK_DEV 1653 select X86_PMEM_LEGACY_DEVICE 1654 select LIBNVDIMM 1655 help 1656 Treat memory marked using the non-standard e820 type of 12 as used 1657 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1658 The kernel will offer these regions to the 'pmem' driver so 1659 they can be used for persistent storage. 1660 1661 Say Y if unsure. 1662 1663config HIGHPTE 1664 bool "Allocate 3rd-level pagetables from highmem" 1665 depends on HIGHMEM 1666 ---help--- 1667 The VM uses one page table entry for each page of physical memory. 1668 For systems with a lot of RAM, this can be wasteful of precious 1669 low memory. Setting this option will put user-space page table 1670 entries in high memory. 1671 1672config X86_CHECK_BIOS_CORRUPTION 1673 bool "Check for low memory corruption" 1674 ---help--- 1675 Periodically check for memory corruption in low memory, which 1676 is suspected to be caused by BIOS. Even when enabled in the 1677 configuration, it is disabled at runtime. Enable it by 1678 setting "memory_corruption_check=1" on the kernel command 1679 line. By default it scans the low 64k of memory every 60 1680 seconds; see the memory_corruption_check_size and 1681 memory_corruption_check_period parameters in 1682 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1683 1684 When enabled with the default parameters, this option has 1685 almost no overhead, as it reserves a relatively small amount 1686 of memory and scans it infrequently. It both detects corruption 1687 and prevents it from affecting the running system. 1688 1689 It is, however, intended as a diagnostic tool; if repeatable 1690 BIOS-originated corruption always affects the same memory, 1691 you can use memmap= to prevent the kernel from using that 1692 memory. 1693 1694config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1695 bool "Set the default setting of memory_corruption_check" 1696 depends on X86_CHECK_BIOS_CORRUPTION 1697 default y 1698 ---help--- 1699 Set whether the default state of memory_corruption_check is 1700 on or off. 1701 1702config X86_RESERVE_LOW 1703 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1704 default 64 1705 range 4 640 1706 ---help--- 1707 Specify the amount of low memory to reserve for the BIOS. 1708 1709 The first page contains BIOS data structures that the kernel 1710 must not use, so that page must always be reserved. 1711 1712 By default we reserve the first 64K of physical RAM, as a 1713 number of BIOSes are known to corrupt that memory range 1714 during events such as suspend/resume or monitor cable 1715 insertion, so it must not be used by the kernel. 1716 1717 You can set this to 4 if you are absolutely sure that you 1718 trust the BIOS to get all its memory reservations and usages 1719 right. If you know your BIOS have problems beyond the 1720 default 64K area, you can set this to 640 to avoid using the 1721 entire low memory range. 1722 1723 If you have doubts about the BIOS (e.g. suspend/resume does 1724 not work or there's kernel crashes after certain hardware 1725 hotplug events) then you might want to enable 1726 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1727 typical corruption patterns. 1728 1729 Leave this to the default value of 64 if you are unsure. 1730 1731config MATH_EMULATION 1732 bool 1733 depends on MODIFY_LDT_SYSCALL 1734 prompt "Math emulation" if X86_32 1735 ---help--- 1736 Linux can emulate a math coprocessor (used for floating point 1737 operations) if you don't have one. 486DX and Pentium processors have 1738 a math coprocessor built in, 486SX and 386 do not, unless you added 1739 a 487DX or 387, respectively. (The messages during boot time can 1740 give you some hints here ["man dmesg"].) Everyone needs either a 1741 coprocessor or this emulation. 1742 1743 If you don't have a math coprocessor, you need to say Y here; if you 1744 say Y here even though you have a coprocessor, the coprocessor will 1745 be used nevertheless. (This behavior can be changed with the kernel 1746 command line option "no387", which comes handy if your coprocessor 1747 is broken. Try "man bootparam" or see the documentation of your boot 1748 loader (lilo or loadlin) about how to pass options to the kernel at 1749 boot time.) This means that it is a good idea to say Y here if you 1750 intend to use this kernel on different machines. 1751 1752 More information about the internals of the Linux math coprocessor 1753 emulation can be found in <file:arch/x86/math-emu/README>. 1754 1755 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1756 kernel, it won't hurt. 1757 1758config MTRR 1759 def_bool y 1760 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1761 ---help--- 1762 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1763 the Memory Type Range Registers (MTRRs) may be used to control 1764 processor access to memory ranges. This is most useful if you have 1765 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1766 allows bus write transfers to be combined into a larger transfer 1767 before bursting over the PCI/AGP bus. This can increase performance 1768 of image write operations 2.5 times or more. Saying Y here creates a 1769 /proc/mtrr file which may be used to manipulate your processor's 1770 MTRRs. Typically the X server should use this. 1771 1772 This code has a reasonably generic interface so that similar 1773 control registers on other processors can be easily supported 1774 as well: 1775 1776 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1777 Registers (ARRs) which provide a similar functionality to MTRRs. For 1778 these, the ARRs are used to emulate the MTRRs. 1779 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1780 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1781 write-combining. All of these processors are supported by this code 1782 and it makes sense to say Y here if you have one of them. 1783 1784 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1785 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1786 can lead to all sorts of problems, so it's good to say Y here. 1787 1788 You can safely say Y even if your machine doesn't have MTRRs, you'll 1789 just add about 9 KB to your kernel. 1790 1791 See <file:Documentation/x86/mtrr.txt> for more information. 1792 1793config MTRR_SANITIZER 1794 def_bool y 1795 prompt "MTRR cleanup support" 1796 depends on MTRR 1797 ---help--- 1798 Convert MTRR layout from continuous to discrete, so X drivers can 1799 add writeback entries. 1800 1801 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1802 The largest mtrr entry size for a continuous block can be set with 1803 mtrr_chunk_size. 1804 1805 If unsure, say Y. 1806 1807config MTRR_SANITIZER_ENABLE_DEFAULT 1808 int "MTRR cleanup enable value (0-1)" 1809 range 0 1 1810 default "0" 1811 depends on MTRR_SANITIZER 1812 ---help--- 1813 Enable mtrr cleanup default value 1814 1815config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1816 int "MTRR cleanup spare reg num (0-7)" 1817 range 0 7 1818 default "1" 1819 depends on MTRR_SANITIZER 1820 ---help--- 1821 mtrr cleanup spare entries default, it can be changed via 1822 mtrr_spare_reg_nr=N on the kernel command line. 1823 1824config X86_PAT 1825 def_bool y 1826 prompt "x86 PAT support" if EXPERT 1827 depends on MTRR 1828 ---help--- 1829 Use PAT attributes to setup page level cache control. 1830 1831 PATs are the modern equivalents of MTRRs and are much more 1832 flexible than MTRRs. 1833 1834 Say N here if you see bootup problems (boot crash, boot hang, 1835 spontaneous reboots) or a non-working video driver. 1836 1837 If unsure, say Y. 1838 1839config ARCH_USES_PG_UNCACHED 1840 def_bool y 1841 depends on X86_PAT 1842 1843config ARCH_RANDOM 1844 def_bool y 1845 prompt "x86 architectural random number generator" if EXPERT 1846 ---help--- 1847 Enable the x86 architectural RDRAND instruction 1848 (Intel Bull Mountain technology) to generate random numbers. 1849 If supported, this is a high bandwidth, cryptographically 1850 secure hardware random number generator. 1851 1852config X86_SMAP 1853 def_bool y 1854 prompt "Supervisor Mode Access Prevention" if EXPERT 1855 ---help--- 1856 Supervisor Mode Access Prevention (SMAP) is a security 1857 feature in newer Intel processors. There is a small 1858 performance cost if this enabled and turned on; there is 1859 also a small increase in the kernel size if this is enabled. 1860 1861 If unsure, say Y. 1862 1863config X86_INTEL_UMIP 1864 def_bool y 1865 depends on CPU_SUP_INTEL 1866 prompt "Intel User Mode Instruction Prevention" if EXPERT 1867 ---help--- 1868 The User Mode Instruction Prevention (UMIP) is a security 1869 feature in newer Intel processors. If enabled, a general 1870 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1871 or STR instructions are executed in user mode. These instructions 1872 unnecessarily expose information about the hardware state. 1873 1874 The vast majority of applications do not use these instructions. 1875 For the very few that do, software emulation is provided in 1876 specific cases in protected and virtual-8086 modes. Emulated 1877 results are dummy. 1878 1879config X86_INTEL_MPX 1880 prompt "Intel MPX (Memory Protection Extensions)" 1881 def_bool n 1882 # Note: only available in 64-bit mode due to VMA flags shortage 1883 depends on CPU_SUP_INTEL && X86_64 1884 select ARCH_USES_HIGH_VMA_FLAGS 1885 ---help--- 1886 MPX provides hardware features that can be used in 1887 conjunction with compiler-instrumented code to check 1888 memory references. It is designed to detect buffer 1889 overflow or underflow bugs. 1890 1891 This option enables running applications which are 1892 instrumented or otherwise use MPX. It does not use MPX 1893 itself inside the kernel or to protect the kernel 1894 against bad memory references. 1895 1896 Enabling this option will make the kernel larger: 1897 ~8k of kernel text and 36 bytes of data on a 64-bit 1898 defconfig. It adds a long to the 'mm_struct' which 1899 will increase the kernel memory overhead of each 1900 process and adds some branches to paths used during 1901 exec() and munmap(). 1902 1903 For details, see Documentation/x86/intel_mpx.txt 1904 1905 If unsure, say N. 1906 1907config X86_INTEL_MEMORY_PROTECTION_KEYS 1908 prompt "Intel Memory Protection Keys" 1909 def_bool y 1910 # Note: only available in 64-bit mode 1911 depends on CPU_SUP_INTEL && X86_64 1912 select ARCH_USES_HIGH_VMA_FLAGS 1913 select ARCH_HAS_PKEYS 1914 ---help--- 1915 Memory Protection Keys provides a mechanism for enforcing 1916 page-based protections, but without requiring modification of the 1917 page tables when an application changes protection domains. 1918 1919 For details, see Documentation/x86/protection-keys.txt 1920 1921 If unsure, say y. 1922 1923config EFI 1924 bool "EFI runtime service support" 1925 depends on ACPI 1926 select UCS2_STRING 1927 select EFI_RUNTIME_WRAPPERS 1928 ---help--- 1929 This enables the kernel to use EFI runtime services that are 1930 available (such as the EFI variable services). 1931 1932 This option is only useful on systems that have EFI firmware. 1933 In addition, you should use the latest ELILO loader available 1934 at <http://elilo.sourceforge.net> in order to take advantage 1935 of EFI runtime services. However, even with this option, the 1936 resultant kernel should continue to boot on existing non-EFI 1937 platforms. 1938 1939config EFI_STUB 1940 bool "EFI stub support" 1941 depends on EFI && !X86_USE_3DNOW 1942 select RELOCATABLE 1943 ---help--- 1944 This kernel feature allows a bzImage to be loaded directly 1945 by EFI firmware without the use of a bootloader. 1946 1947 See Documentation/efi-stub.txt for more information. 1948 1949config EFI_MIXED 1950 bool "EFI mixed-mode support" 1951 depends on EFI_STUB && X86_64 1952 ---help--- 1953 Enabling this feature allows a 64-bit kernel to be booted 1954 on a 32-bit firmware, provided that your CPU supports 64-bit 1955 mode. 1956 1957 Note that it is not possible to boot a mixed-mode enabled 1958 kernel via the EFI boot stub - a bootloader that supports 1959 the EFI handover protocol must be used. 1960 1961 If unsure, say N. 1962 1963config SECCOMP 1964 def_bool y 1965 prompt "Enable seccomp to safely compute untrusted bytecode" 1966 ---help--- 1967 This kernel feature is useful for number crunching applications 1968 that may need to compute untrusted bytecode during their 1969 execution. By using pipes or other transports made available to 1970 the process as file descriptors supporting the read/write 1971 syscalls, it's possible to isolate those applications in 1972 their own address space using seccomp. Once seccomp is 1973 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1974 and the task is only allowed to execute a few safe syscalls 1975 defined by each seccomp mode. 1976 1977 If unsure, say Y. Only embedded should say N here. 1978 1979source kernel/Kconfig.hz 1980 1981config KEXEC 1982 bool "kexec system call" 1983 select KEXEC_CORE 1984 ---help--- 1985 kexec is a system call that implements the ability to shutdown your 1986 current kernel, and to start another kernel. It is like a reboot 1987 but it is independent of the system firmware. And like a reboot 1988 you can start any kernel with it, not just Linux. 1989 1990 The name comes from the similarity to the exec system call. 1991 1992 It is an ongoing process to be certain the hardware in a machine 1993 is properly shutdown, so do not be surprised if this code does not 1994 initially work for you. As of this writing the exact hardware 1995 interface is strongly in flux, so no good recommendation can be 1996 made. 1997 1998config KEXEC_FILE 1999 bool "kexec file based system call" 2000 select KEXEC_CORE 2001 select BUILD_BIN2C 2002 depends on X86_64 2003 depends on CRYPTO=y 2004 depends on CRYPTO_SHA256=y 2005 ---help--- 2006 This is new version of kexec system call. This system call is 2007 file based and takes file descriptors as system call argument 2008 for kernel and initramfs as opposed to list of segments as 2009 accepted by previous system call. 2010 2011config KEXEC_VERIFY_SIG 2012 bool "Verify kernel signature during kexec_file_load() syscall" 2013 depends on KEXEC_FILE 2014 ---help--- 2015 This option makes kernel signature verification mandatory for 2016 the kexec_file_load() syscall. 2017 2018 In addition to that option, you need to enable signature 2019 verification for the corresponding kernel image type being 2020 loaded in order for this to work. 2021 2022config KEXEC_BZIMAGE_VERIFY_SIG 2023 bool "Enable bzImage signature verification support" 2024 depends on KEXEC_VERIFY_SIG 2025 depends on SIGNED_PE_FILE_VERIFICATION 2026 select SYSTEM_TRUSTED_KEYRING 2027 ---help--- 2028 Enable bzImage signature verification support. 2029 2030config CRASH_DUMP 2031 bool "kernel crash dumps" 2032 depends on X86_64 || (X86_32 && HIGHMEM) 2033 ---help--- 2034 Generate crash dump after being started by kexec. 2035 This should be normally only set in special crash dump kernels 2036 which are loaded in the main kernel with kexec-tools into 2037 a specially reserved region and then later executed after 2038 a crash by kdump/kexec. The crash dump kernel must be compiled 2039 to a memory address not used by the main kernel or BIOS using 2040 PHYSICAL_START, or it must be built as a relocatable image 2041 (CONFIG_RELOCATABLE=y). 2042 For more details see Documentation/kdump/kdump.txt 2043 2044config KEXEC_JUMP 2045 bool "kexec jump" 2046 depends on KEXEC && HIBERNATION 2047 ---help--- 2048 Jump between original kernel and kexeced kernel and invoke 2049 code in physical address mode via KEXEC 2050 2051config PHYSICAL_START 2052 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2053 default "0x1000000" 2054 ---help--- 2055 This gives the physical address where the kernel is loaded. 2056 2057 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2058 bzImage will decompress itself to above physical address and 2059 run from there. Otherwise, bzImage will run from the address where 2060 it has been loaded by the boot loader and will ignore above physical 2061 address. 2062 2063 In normal kdump cases one does not have to set/change this option 2064 as now bzImage can be compiled as a completely relocatable image 2065 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2066 address. This option is mainly useful for the folks who don't want 2067 to use a bzImage for capturing the crash dump and want to use a 2068 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2069 to be specifically compiled to run from a specific memory area 2070 (normally a reserved region) and this option comes handy. 2071 2072 So if you are using bzImage for capturing the crash dump, 2073 leave the value here unchanged to 0x1000000 and set 2074 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2075 for capturing the crash dump change this value to start of 2076 the reserved region. In other words, it can be set based on 2077 the "X" value as specified in the "crashkernel=YM@XM" 2078 command line boot parameter passed to the panic-ed 2079 kernel. Please take a look at Documentation/kdump/kdump.txt 2080 for more details about crash dumps. 2081 2082 Usage of bzImage for capturing the crash dump is recommended as 2083 one does not have to build two kernels. Same kernel can be used 2084 as production kernel and capture kernel. Above option should have 2085 gone away after relocatable bzImage support is introduced. But it 2086 is present because there are users out there who continue to use 2087 vmlinux for dump capture. This option should go away down the 2088 line. 2089 2090 Don't change this unless you know what you are doing. 2091 2092config RELOCATABLE 2093 bool "Build a relocatable kernel" 2094 default y 2095 ---help--- 2096 This builds a kernel image that retains relocation information 2097 so it can be loaded someplace besides the default 1MB. 2098 The relocations tend to make the kernel binary about 10% larger, 2099 but are discarded at runtime. 2100 2101 One use is for the kexec on panic case where the recovery kernel 2102 must live at a different physical address than the primary 2103 kernel. 2104 2105 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2106 it has been loaded at and the compile time physical address 2107 (CONFIG_PHYSICAL_START) is used as the minimum location. 2108 2109config RANDOMIZE_BASE 2110 bool "Randomize the address of the kernel image (KASLR)" 2111 depends on RELOCATABLE 2112 default y 2113 ---help--- 2114 In support of Kernel Address Space Layout Randomization (KASLR), 2115 this randomizes the physical address at which the kernel image 2116 is decompressed and the virtual address where the kernel 2117 image is mapped, as a security feature that deters exploit 2118 attempts relying on knowledge of the location of kernel 2119 code internals. 2120 2121 On 64-bit, the kernel physical and virtual addresses are 2122 randomized separately. The physical address will be anywhere 2123 between 16MB and the top of physical memory (up to 64TB). The 2124 virtual address will be randomized from 16MB up to 1GB (9 bits 2125 of entropy). Note that this also reduces the memory space 2126 available to kernel modules from 1.5GB to 1GB. 2127 2128 On 32-bit, the kernel physical and virtual addresses are 2129 randomized together. They will be randomized from 16MB up to 2130 512MB (8 bits of entropy). 2131 2132 Entropy is generated using the RDRAND instruction if it is 2133 supported. If RDTSC is supported, its value is mixed into 2134 the entropy pool as well. If neither RDRAND nor RDTSC are 2135 supported, then entropy is read from the i8254 timer. The 2136 usable entropy is limited by the kernel being built using 2137 2GB addressing, and that PHYSICAL_ALIGN must be at a 2138 minimum of 2MB. As a result, only 10 bits of entropy are 2139 theoretically possible, but the implementations are further 2140 limited due to memory layouts. 2141 2142 If unsure, say Y. 2143 2144# Relocation on x86 needs some additional build support 2145config X86_NEED_RELOCS 2146 def_bool y 2147 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2148 2149config PHYSICAL_ALIGN 2150 hex "Alignment value to which kernel should be aligned" 2151 default "0x200000" 2152 range 0x2000 0x1000000 if X86_32 2153 range 0x200000 0x1000000 if X86_64 2154 ---help--- 2155 This value puts the alignment restrictions on physical address 2156 where kernel is loaded and run from. Kernel is compiled for an 2157 address which meets above alignment restriction. 2158 2159 If bootloader loads the kernel at a non-aligned address and 2160 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2161 address aligned to above value and run from there. 2162 2163 If bootloader loads the kernel at a non-aligned address and 2164 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2165 load address and decompress itself to the address it has been 2166 compiled for and run from there. The address for which kernel is 2167 compiled already meets above alignment restrictions. Hence the 2168 end result is that kernel runs from a physical address meeting 2169 above alignment restrictions. 2170 2171 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2172 this value must be a multiple of 0x200000. 2173 2174 Don't change this unless you know what you are doing. 2175 2176config DYNAMIC_MEMORY_LAYOUT 2177 bool 2178 ---help--- 2179 This option makes base addresses of vmalloc and vmemmap as well as 2180 __PAGE_OFFSET movable during boot. 2181 2182config RANDOMIZE_MEMORY 2183 bool "Randomize the kernel memory sections" 2184 depends on X86_64 2185 depends on RANDOMIZE_BASE 2186 select DYNAMIC_MEMORY_LAYOUT 2187 default RANDOMIZE_BASE 2188 ---help--- 2189 Randomizes the base virtual address of kernel memory sections 2190 (physical memory mapping, vmalloc & vmemmap). This security feature 2191 makes exploits relying on predictable memory locations less reliable. 2192 2193 The order of allocations remains unchanged. Entropy is generated in 2194 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2195 configuration have in average 30,000 different possible virtual 2196 addresses for each memory section. 2197 2198 If unsure, say Y. 2199 2200config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2201 hex "Physical memory mapping padding" if EXPERT 2202 depends on RANDOMIZE_MEMORY 2203 default "0xa" if MEMORY_HOTPLUG 2204 default "0x0" 2205 range 0x1 0x40 if MEMORY_HOTPLUG 2206 range 0x0 0x40 2207 ---help--- 2208 Define the padding in terabytes added to the existing physical 2209 memory size during kernel memory randomization. It is useful 2210 for memory hotplug support but reduces the entropy available for 2211 address randomization. 2212 2213 If unsure, leave at the default value. 2214 2215config HOTPLUG_CPU 2216 bool "Support for hot-pluggable CPUs" 2217 depends on SMP 2218 ---help--- 2219 Say Y here to allow turning CPUs off and on. CPUs can be 2220 controlled through /sys/devices/system/cpu. 2221 ( Note: power management support will enable this option 2222 automatically on SMP systems. ) 2223 Say N if you want to disable CPU hotplug. 2224 2225config BOOTPARAM_HOTPLUG_CPU0 2226 bool "Set default setting of cpu0_hotpluggable" 2227 default n 2228 depends on HOTPLUG_CPU 2229 ---help--- 2230 Set whether default state of cpu0_hotpluggable is on or off. 2231 2232 Say Y here to enable CPU0 hotplug by default. If this switch 2233 is turned on, there is no need to give cpu0_hotplug kernel 2234 parameter and the CPU0 hotplug feature is enabled by default. 2235 2236 Please note: there are two known CPU0 dependencies if you want 2237 to enable the CPU0 hotplug feature either by this switch or by 2238 cpu0_hotplug kernel parameter. 2239 2240 First, resume from hibernate or suspend always starts from CPU0. 2241 So hibernate and suspend are prevented if CPU0 is offline. 2242 2243 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2244 offline if any interrupt can not migrate out of CPU0. There may 2245 be other CPU0 dependencies. 2246 2247 Please make sure the dependencies are under your control before 2248 you enable this feature. 2249 2250 Say N if you don't want to enable CPU0 hotplug feature by default. 2251 You still can enable the CPU0 hotplug feature at boot by kernel 2252 parameter cpu0_hotplug. 2253 2254config DEBUG_HOTPLUG_CPU0 2255 def_bool n 2256 prompt "Debug CPU0 hotplug" 2257 depends on HOTPLUG_CPU 2258 ---help--- 2259 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2260 soon as possible and boots up userspace with CPU0 offlined. User 2261 can online CPU0 back after boot time. 2262 2263 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2264 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2265 compilation or giving cpu0_hotplug kernel parameter at boot. 2266 2267 If unsure, say N. 2268 2269config COMPAT_VDSO 2270 def_bool n 2271 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2272 depends on COMPAT_32 2273 ---help--- 2274 Certain buggy versions of glibc will crash if they are 2275 presented with a 32-bit vDSO that is not mapped at the address 2276 indicated in its segment table. 2277 2278 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2279 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2280 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2281 the only released version with the bug, but OpenSUSE 9 2282 contains a buggy "glibc 2.3.2". 2283 2284 The symptom of the bug is that everything crashes on startup, saying: 2285 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2286 2287 Saying Y here changes the default value of the vdso32 boot 2288 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2289 This works around the glibc bug but hurts performance. 2290 2291 If unsure, say N: if you are compiling your own kernel, you 2292 are unlikely to be using a buggy version of glibc. 2293 2294choice 2295 prompt "vsyscall table for legacy applications" 2296 depends on X86_64 2297 default LEGACY_VSYSCALL_EMULATE 2298 help 2299 Legacy user code that does not know how to find the vDSO expects 2300 to be able to issue three syscalls by calling fixed addresses in 2301 kernel space. Since this location is not randomized with ASLR, 2302 it can be used to assist security vulnerability exploitation. 2303 2304 This setting can be changed at boot time via the kernel command 2305 line parameter vsyscall=[emulate|none]. 2306 2307 On a system with recent enough glibc (2.14 or newer) and no 2308 static binaries, you can say None without a performance penalty 2309 to improve security. 2310 2311 If unsure, select "Emulate". 2312 2313 config LEGACY_VSYSCALL_EMULATE 2314 bool "Emulate" 2315 help 2316 The kernel traps and emulates calls into the fixed 2317 vsyscall address mapping. This makes the mapping 2318 non-executable, but it still contains known contents, 2319 which could be used in certain rare security vulnerability 2320 exploits. This configuration is recommended when userspace 2321 still uses the vsyscall area. 2322 2323 config LEGACY_VSYSCALL_NONE 2324 bool "None" 2325 help 2326 There will be no vsyscall mapping at all. This will 2327 eliminate any risk of ASLR bypass due to the vsyscall 2328 fixed address mapping. Attempts to use the vsyscalls 2329 will be reported to dmesg, so that either old or 2330 malicious userspace programs can be identified. 2331 2332endchoice 2333 2334config CMDLINE_BOOL 2335 bool "Built-in kernel command line" 2336 ---help--- 2337 Allow for specifying boot arguments to the kernel at 2338 build time. On some systems (e.g. embedded ones), it is 2339 necessary or convenient to provide some or all of the 2340 kernel boot arguments with the kernel itself (that is, 2341 to not rely on the boot loader to provide them.) 2342 2343 To compile command line arguments into the kernel, 2344 set this option to 'Y', then fill in the 2345 boot arguments in CONFIG_CMDLINE. 2346 2347 Systems with fully functional boot loaders (i.e. non-embedded) 2348 should leave this option set to 'N'. 2349 2350config CMDLINE 2351 string "Built-in kernel command string" 2352 depends on CMDLINE_BOOL 2353 default "" 2354 ---help--- 2355 Enter arguments here that should be compiled into the kernel 2356 image and used at boot time. If the boot loader provides a 2357 command line at boot time, it is appended to this string to 2358 form the full kernel command line, when the system boots. 2359 2360 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2361 change this behavior. 2362 2363 In most cases, the command line (whether built-in or provided 2364 by the boot loader) should specify the device for the root 2365 file system. 2366 2367config CMDLINE_OVERRIDE 2368 bool "Built-in command line overrides boot loader arguments" 2369 depends on CMDLINE_BOOL 2370 ---help--- 2371 Set this option to 'Y' to have the kernel ignore the boot loader 2372 command line, and use ONLY the built-in command line. 2373 2374 This is used to work around broken boot loaders. This should 2375 be set to 'N' under normal conditions. 2376 2377config MODIFY_LDT_SYSCALL 2378 bool "Enable the LDT (local descriptor table)" if EXPERT 2379 default y 2380 ---help--- 2381 Linux can allow user programs to install a per-process x86 2382 Local Descriptor Table (LDT) using the modify_ldt(2) system 2383 call. This is required to run 16-bit or segmented code such as 2384 DOSEMU or some Wine programs. It is also used by some very old 2385 threading libraries. 2386 2387 Enabling this feature adds a small amount of overhead to 2388 context switches and increases the low-level kernel attack 2389 surface. Disabling it removes the modify_ldt(2) system call. 2390 2391 Saying 'N' here may make sense for embedded or server kernels. 2392 2393source "kernel/livepatch/Kconfig" 2394 2395endmenu 2396 2397config ARCH_HAS_ADD_PAGES 2398 def_bool y 2399 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2400 2401config ARCH_ENABLE_MEMORY_HOTPLUG 2402 def_bool y 2403 depends on X86_64 || (X86_32 && HIGHMEM) 2404 2405config ARCH_ENABLE_MEMORY_HOTREMOVE 2406 def_bool y 2407 depends on MEMORY_HOTPLUG 2408 2409config USE_PERCPU_NUMA_NODE_ID 2410 def_bool y 2411 depends on NUMA 2412 2413config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2414 def_bool y 2415 depends on X86_64 || X86_PAE 2416 2417config ARCH_ENABLE_HUGEPAGE_MIGRATION 2418 def_bool y 2419 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2420 2421config ARCH_ENABLE_THP_MIGRATION 2422 def_bool y 2423 depends on X86_64 && TRANSPARENT_HUGEPAGE 2424 2425menu "Power management and ACPI options" 2426 2427config ARCH_HIBERNATION_HEADER 2428 def_bool y 2429 depends on X86_64 && HIBERNATION 2430 2431source "kernel/power/Kconfig" 2432 2433source "drivers/acpi/Kconfig" 2434 2435source "drivers/sfi/Kconfig" 2436 2437config X86_APM_BOOT 2438 def_bool y 2439 depends on APM 2440 2441menuconfig APM 2442 tristate "APM (Advanced Power Management) BIOS support" 2443 depends on X86_32 && PM_SLEEP 2444 ---help--- 2445 APM is a BIOS specification for saving power using several different 2446 techniques. This is mostly useful for battery powered laptops with 2447 APM compliant BIOSes. If you say Y here, the system time will be 2448 reset after a RESUME operation, the /proc/apm device will provide 2449 battery status information, and user-space programs will receive 2450 notification of APM "events" (e.g. battery status change). 2451 2452 If you select "Y" here, you can disable actual use of the APM 2453 BIOS by passing the "apm=off" option to the kernel at boot time. 2454 2455 Note that the APM support is almost completely disabled for 2456 machines with more than one CPU. 2457 2458 In order to use APM, you will need supporting software. For location 2459 and more information, read <file:Documentation/power/apm-acpi.txt> 2460 and the Battery Powered Linux mini-HOWTO, available from 2461 <http://www.tldp.org/docs.html#howto>. 2462 2463 This driver does not spin down disk drives (see the hdparm(8) 2464 manpage ("man 8 hdparm") for that), and it doesn't turn off 2465 VESA-compliant "green" monitors. 2466 2467 This driver does not support the TI 4000M TravelMate and the ACER 2468 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2469 desktop machines also don't have compliant BIOSes, and this driver 2470 may cause those machines to panic during the boot phase. 2471 2472 Generally, if you don't have a battery in your machine, there isn't 2473 much point in using this driver and you should say N. If you get 2474 random kernel OOPSes or reboots that don't seem to be related to 2475 anything, try disabling/enabling this option (or disabling/enabling 2476 APM in your BIOS). 2477 2478 Some other things you should try when experiencing seemingly random, 2479 "weird" problems: 2480 2481 1) make sure that you have enough swap space and that it is 2482 enabled. 2483 2) pass the "no-hlt" option to the kernel 2484 3) switch on floating point emulation in the kernel and pass 2485 the "no387" option to the kernel 2486 4) pass the "floppy=nodma" option to the kernel 2487 5) pass the "mem=4M" option to the kernel (thereby disabling 2488 all but the first 4 MB of RAM) 2489 6) make sure that the CPU is not over clocked. 2490 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2491 8) disable the cache from your BIOS settings 2492 9) install a fan for the video card or exchange video RAM 2493 10) install a better fan for the CPU 2494 11) exchange RAM chips 2495 12) exchange the motherboard. 2496 2497 To compile this driver as a module, choose M here: the 2498 module will be called apm. 2499 2500if APM 2501 2502config APM_IGNORE_USER_SUSPEND 2503 bool "Ignore USER SUSPEND" 2504 ---help--- 2505 This option will ignore USER SUSPEND requests. On machines with a 2506 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2507 series notebooks, it is necessary to say Y because of a BIOS bug. 2508 2509config APM_DO_ENABLE 2510 bool "Enable PM at boot time" 2511 ---help--- 2512 Enable APM features at boot time. From page 36 of the APM BIOS 2513 specification: "When disabled, the APM BIOS does not automatically 2514 power manage devices, enter the Standby State, enter the Suspend 2515 State, or take power saving steps in response to CPU Idle calls." 2516 This driver will make CPU Idle calls when Linux is idle (unless this 2517 feature is turned off -- see "Do CPU IDLE calls", below). This 2518 should always save battery power, but more complicated APM features 2519 will be dependent on your BIOS implementation. You may need to turn 2520 this option off if your computer hangs at boot time when using APM 2521 support, or if it beeps continuously instead of suspending. Turn 2522 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2523 T400CDT. This is off by default since most machines do fine without 2524 this feature. 2525 2526config APM_CPU_IDLE 2527 depends on CPU_IDLE 2528 bool "Make CPU Idle calls when idle" 2529 ---help--- 2530 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2531 On some machines, this can activate improved power savings, such as 2532 a slowed CPU clock rate, when the machine is idle. These idle calls 2533 are made after the idle loop has run for some length of time (e.g., 2534 333 mS). On some machines, this will cause a hang at boot time or 2535 whenever the CPU becomes idle. (On machines with more than one CPU, 2536 this option does nothing.) 2537 2538config APM_DISPLAY_BLANK 2539 bool "Enable console blanking using APM" 2540 ---help--- 2541 Enable console blanking using the APM. Some laptops can use this to 2542 turn off the LCD backlight when the screen blanker of the Linux 2543 virtual console blanks the screen. Note that this is only used by 2544 the virtual console screen blanker, and won't turn off the backlight 2545 when using the X Window system. This also doesn't have anything to 2546 do with your VESA-compliant power-saving monitor. Further, this 2547 option doesn't work for all laptops -- it might not turn off your 2548 backlight at all, or it might print a lot of errors to the console, 2549 especially if you are using gpm. 2550 2551config APM_ALLOW_INTS 2552 bool "Allow interrupts during APM BIOS calls" 2553 ---help--- 2554 Normally we disable external interrupts while we are making calls to 2555 the APM BIOS as a measure to lessen the effects of a badly behaving 2556 BIOS implementation. The BIOS should reenable interrupts if it 2557 needs to. Unfortunately, some BIOSes do not -- especially those in 2558 many of the newer IBM Thinkpads. If you experience hangs when you 2559 suspend, try setting this to Y. Otherwise, say N. 2560 2561endif # APM 2562 2563source "drivers/cpufreq/Kconfig" 2564 2565source "drivers/cpuidle/Kconfig" 2566 2567source "drivers/idle/Kconfig" 2568 2569endmenu 2570 2571 2572menu "Bus options (PCI etc.)" 2573 2574config PCI 2575 bool "PCI support" 2576 default y 2577 ---help--- 2578 Find out whether you have a PCI motherboard. PCI is the name of a 2579 bus system, i.e. the way the CPU talks to the other stuff inside 2580 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2581 VESA. If you have PCI, say Y, otherwise N. 2582 2583choice 2584 prompt "PCI access mode" 2585 depends on X86_32 && PCI 2586 default PCI_GOANY 2587 ---help--- 2588 On PCI systems, the BIOS can be used to detect the PCI devices and 2589 determine their configuration. However, some old PCI motherboards 2590 have BIOS bugs and may crash if this is done. Also, some embedded 2591 PCI-based systems don't have any BIOS at all. Linux can also try to 2592 detect the PCI hardware directly without using the BIOS. 2593 2594 With this option, you can specify how Linux should detect the 2595 PCI devices. If you choose "BIOS", the BIOS will be used, 2596 if you choose "Direct", the BIOS won't be used, and if you 2597 choose "MMConfig", then PCI Express MMCONFIG will be used. 2598 If you choose "Any", the kernel will try MMCONFIG, then the 2599 direct access method and falls back to the BIOS if that doesn't 2600 work. If unsure, go with the default, which is "Any". 2601 2602config PCI_GOBIOS 2603 bool "BIOS" 2604 2605config PCI_GOMMCONFIG 2606 bool "MMConfig" 2607 2608config PCI_GODIRECT 2609 bool "Direct" 2610 2611config PCI_GOOLPC 2612 bool "OLPC XO-1" 2613 depends on OLPC 2614 2615config PCI_GOANY 2616 bool "Any" 2617 2618endchoice 2619 2620config PCI_BIOS 2621 def_bool y 2622 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2623 2624# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2625config PCI_DIRECT 2626 def_bool y 2627 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2628 2629config PCI_MMCONFIG 2630 bool "Support mmconfig PCI config space access" if X86_64 2631 default y 2632 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2633 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2634 2635config PCI_OLPC 2636 def_bool y 2637 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2638 2639config PCI_XEN 2640 def_bool y 2641 depends on PCI && XEN 2642 select SWIOTLB_XEN 2643 2644config PCI_DOMAINS 2645 def_bool y 2646 depends on PCI 2647 2648config MMCONF_FAM10H 2649 def_bool y 2650 depends on X86_64 && PCI_MMCONFIG && ACPI 2651 2652config PCI_CNB20LE_QUIRK 2653 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2654 depends on PCI 2655 help 2656 Read the PCI windows out of the CNB20LE host bridge. This allows 2657 PCI hotplug to work on systems with the CNB20LE chipset which do 2658 not have ACPI. 2659 2660 There's no public spec for this chipset, and this functionality 2661 is known to be incomplete. 2662 2663 You should say N unless you know you need this. 2664 2665source "drivers/pci/Kconfig" 2666 2667config ISA_BUS 2668 bool "ISA bus support on modern systems" if EXPERT 2669 help 2670 Expose ISA bus device drivers and options available for selection and 2671 configuration. Enable this option if your target machine has an ISA 2672 bus. ISA is an older system, displaced by PCI and newer bus 2673 architectures -- if your target machine is modern, it probably does 2674 not have an ISA bus. 2675 2676 If unsure, say N. 2677 2678# x86_64 have no ISA slots, but can have ISA-style DMA. 2679config ISA_DMA_API 2680 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2681 default y 2682 help 2683 Enables ISA-style DMA support for devices requiring such controllers. 2684 If unsure, say Y. 2685 2686if X86_32 2687 2688config ISA 2689 bool "ISA support" 2690 ---help--- 2691 Find out whether you have ISA slots on your motherboard. ISA is the 2692 name of a bus system, i.e. the way the CPU talks to the other stuff 2693 inside your box. Other bus systems are PCI, EISA, MicroChannel 2694 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2695 newer boards don't support it. If you have ISA, say Y, otherwise N. 2696 2697config EISA 2698 bool "EISA support" 2699 depends on ISA 2700 ---help--- 2701 The Extended Industry Standard Architecture (EISA) bus was 2702 developed as an open alternative to the IBM MicroChannel bus. 2703 2704 The EISA bus provided some of the features of the IBM MicroChannel 2705 bus while maintaining backward compatibility with cards made for 2706 the older ISA bus. The EISA bus saw limited use between 1988 and 2707 1995 when it was made obsolete by the PCI bus. 2708 2709 Say Y here if you are building a kernel for an EISA-based machine. 2710 2711 Otherwise, say N. 2712 2713source "drivers/eisa/Kconfig" 2714 2715config SCx200 2716 tristate "NatSemi SCx200 support" 2717 ---help--- 2718 This provides basic support for National Semiconductor's 2719 (now AMD's) Geode processors. The driver probes for the 2720 PCI-IDs of several on-chip devices, so its a good dependency 2721 for other scx200_* drivers. 2722 2723 If compiled as a module, the driver is named scx200. 2724 2725config SCx200HR_TIMER 2726 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2727 depends on SCx200 2728 default y 2729 ---help--- 2730 This driver provides a clocksource built upon the on-chip 2731 27MHz high-resolution timer. Its also a workaround for 2732 NSC Geode SC-1100's buggy TSC, which loses time when the 2733 processor goes idle (as is done by the scheduler). The 2734 other workaround is idle=poll boot option. 2735 2736config OLPC 2737 bool "One Laptop Per Child support" 2738 depends on !X86_PAE 2739 select GPIOLIB 2740 select OF 2741 select OF_PROMTREE 2742 select IRQ_DOMAIN 2743 ---help--- 2744 Add support for detecting the unique features of the OLPC 2745 XO hardware. 2746 2747config OLPC_XO1_PM 2748 bool "OLPC XO-1 Power Management" 2749 depends on OLPC && MFD_CS5535 && PM_SLEEP 2750 select MFD_CORE 2751 ---help--- 2752 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2753 2754config OLPC_XO1_RTC 2755 bool "OLPC XO-1 Real Time Clock" 2756 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2757 ---help--- 2758 Add support for the XO-1 real time clock, which can be used as a 2759 programmable wakeup source. 2760 2761config OLPC_XO1_SCI 2762 bool "OLPC XO-1 SCI extras" 2763 depends on OLPC && OLPC_XO1_PM 2764 depends on INPUT=y 2765 select POWER_SUPPLY 2766 select GPIO_CS5535 2767 select MFD_CORE 2768 ---help--- 2769 Add support for SCI-based features of the OLPC XO-1 laptop: 2770 - EC-driven system wakeups 2771 - Power button 2772 - Ebook switch 2773 - Lid switch 2774 - AC adapter status updates 2775 - Battery status updates 2776 2777config OLPC_XO15_SCI 2778 bool "OLPC XO-1.5 SCI extras" 2779 depends on OLPC && ACPI 2780 select POWER_SUPPLY 2781 ---help--- 2782 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2783 - EC-driven system wakeups 2784 - AC adapter status updates 2785 - Battery status updates 2786 2787config ALIX 2788 bool "PCEngines ALIX System Support (LED setup)" 2789 select GPIOLIB 2790 ---help--- 2791 This option enables system support for the PCEngines ALIX. 2792 At present this just sets up LEDs for GPIO control on 2793 ALIX2/3/6 boards. However, other system specific setup should 2794 get added here. 2795 2796 Note: You must still enable the drivers for GPIO and LED support 2797 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2798 2799 Note: You have to set alix.force=1 for boards with Award BIOS. 2800 2801config NET5501 2802 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2803 select GPIOLIB 2804 ---help--- 2805 This option enables system support for the Soekris Engineering net5501. 2806 2807config GEOS 2808 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2809 select GPIOLIB 2810 depends on DMI 2811 ---help--- 2812 This option enables system support for the Traverse Technologies GEOS. 2813 2814config TS5500 2815 bool "Technologic Systems TS-5500 platform support" 2816 depends on MELAN 2817 select CHECK_SIGNATURE 2818 select NEW_LEDS 2819 select LEDS_CLASS 2820 ---help--- 2821 This option enables system support for the Technologic Systems TS-5500. 2822 2823endif # X86_32 2824 2825config AMD_NB 2826 def_bool y 2827 depends on CPU_SUP_AMD && PCI 2828 2829source "drivers/pcmcia/Kconfig" 2830 2831config RAPIDIO 2832 tristate "RapidIO support" 2833 depends on PCI 2834 default n 2835 help 2836 If enabled this option will include drivers and the core 2837 infrastructure code to support RapidIO interconnect devices. 2838 2839source "drivers/rapidio/Kconfig" 2840 2841config X86_SYSFB 2842 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2843 help 2844 Firmwares often provide initial graphics framebuffers so the BIOS, 2845 bootloader or kernel can show basic video-output during boot for 2846 user-guidance and debugging. Historically, x86 used the VESA BIOS 2847 Extensions and EFI-framebuffers for this, which are mostly limited 2848 to x86. 2849 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2850 framebuffers so the new generic system-framebuffer drivers can be 2851 used on x86. If the framebuffer is not compatible with the generic 2852 modes, it is adverticed as fallback platform framebuffer so legacy 2853 drivers like efifb, vesafb and uvesafb can pick it up. 2854 If this option is not selected, all system framebuffers are always 2855 marked as fallback platform framebuffers as usual. 2856 2857 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2858 not be able to pick up generic system framebuffers if this option 2859 is selected. You are highly encouraged to enable simplefb as 2860 replacement if you select this option. simplefb can correctly deal 2861 with generic system framebuffers. But you should still keep vesafb 2862 and others enabled as fallback if a system framebuffer is 2863 incompatible with simplefb. 2864 2865 If unsure, say Y. 2866 2867endmenu 2868 2869 2870menu "Executable file formats / Emulations" 2871 2872source "fs/Kconfig.binfmt" 2873 2874config IA32_EMULATION 2875 bool "IA32 Emulation" 2876 depends on X86_64 2877 select ARCH_WANT_OLD_COMPAT_IPC 2878 select BINFMT_ELF 2879 select COMPAT_BINFMT_ELF 2880 select COMPAT_OLD_SIGACTION 2881 ---help--- 2882 Include code to run legacy 32-bit programs under a 2883 64-bit kernel. You should likely turn this on, unless you're 2884 100% sure that you don't have any 32-bit programs left. 2885 2886config IA32_AOUT 2887 tristate "IA32 a.out support" 2888 depends on IA32_EMULATION 2889 ---help--- 2890 Support old a.out binaries in the 32bit emulation. 2891 2892config X86_X32 2893 bool "x32 ABI for 64-bit mode" 2894 depends on X86_64 2895 ---help--- 2896 Include code to run binaries for the x32 native 32-bit ABI 2897 for 64-bit processors. An x32 process gets access to the 2898 full 64-bit register file and wide data path while leaving 2899 pointers at 32 bits for smaller memory footprint. 2900 2901 You will need a recent binutils (2.22 or later) with 2902 elf32_x86_64 support enabled to compile a kernel with this 2903 option set. 2904 2905config COMPAT_32 2906 def_bool y 2907 depends on IA32_EMULATION || X86_32 2908 select HAVE_UID16 2909 select OLD_SIGSUSPEND3 2910 2911config COMPAT 2912 def_bool y 2913 depends on IA32_EMULATION || X86_X32 2914 2915if COMPAT 2916config COMPAT_FOR_U64_ALIGNMENT 2917 def_bool y 2918 2919config SYSVIPC_COMPAT 2920 def_bool y 2921 depends on SYSVIPC 2922endif 2923 2924endmenu 2925 2926 2927config HAVE_ATOMIC_IOMAP 2928 def_bool y 2929 depends on X86_32 2930 2931config X86_DEV_DMA_OPS 2932 bool 2933 depends on X86_64 || STA2X11 2934 2935config X86_DMA_REMAP 2936 bool 2937 depends on STA2X11 2938 2939config HAVE_GENERIC_GUP 2940 def_bool y 2941 2942source "net/Kconfig" 2943 2944source "drivers/Kconfig" 2945 2946source "drivers/firmware/Kconfig" 2947 2948source "fs/Kconfig" 2949 2950source "arch/x86/Kconfig.debug" 2951 2952source "security/Kconfig" 2953 2954source "crypto/Kconfig" 2955 2956source "arch/x86/kvm/Kconfig" 2957 2958source "lib/Kconfig" 2959