1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if ARCH = "x86" 5 default ARCH != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_AOUT 18 select HAVE_GENERIC_DMA_COHERENT 19 select MODULES_USE_ELF_REL 20 select OLD_SIGACTION 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select X86_DEV_DMA_OPS 32 33# 34# Arch settings 35# 36# ( Note that options that are marked 'if X86_64' could in principle be 37# ported to 32-bit as well. ) 38# 39config X86 40 def_bool y 41 # 42 # Note: keep this list sorted alphabetically 43 # 44 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 45 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 46 select ANON_INODES 47 select ARCH_CLOCKSOURCE_DATA 48 select ARCH_DISCARD_MEMBLOCK 49 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 50 select ARCH_HAS_DEBUG_VIRTUAL 51 select ARCH_HAS_DEVMEM_IS_ALLOWED 52 select ARCH_HAS_ELF_RANDOMIZE 53 select ARCH_HAS_FAST_MULTIPLIER 54 select ARCH_HAS_FORTIFY_SOURCE 55 select ARCH_HAS_GCOV_PROFILE_ALL 56 select ARCH_HAS_KCOV if X86_64 57 select ARCH_HAS_PMEM_API if X86_64 58 select ARCH_HAS_REFCOUNT 59 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 60 select ARCH_HAS_SET_MEMORY 61 select ARCH_HAS_SG_CHAIN 62 select ARCH_HAS_STRICT_KERNEL_RWX 63 select ARCH_HAS_STRICT_MODULE_RWX 64 select ARCH_HAS_UBSAN_SANITIZE_ALL 65 select ARCH_HAS_ZONE_DEVICE if X86_64 66 select ARCH_HAVE_NMI_SAFE_CMPXCHG 67 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 68 select ARCH_MIGHT_HAVE_PC_PARPORT 69 select ARCH_MIGHT_HAVE_PC_SERIO 70 select ARCH_SUPPORTS_ATOMIC_RMW 71 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 72 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 73 select ARCH_USE_BUILTIN_BSWAP 74 select ARCH_USE_QUEUED_RWLOCKS 75 select ARCH_USE_QUEUED_SPINLOCKS 76 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 77 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 78 select ARCH_WANTS_THP_SWAP if X86_64 79 select BUILDTIME_EXTABLE_SORT 80 select CLKEVT_I8253 81 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 82 select CLOCKSOURCE_WATCHDOG 83 select DCACHE_WORD_ACCESS 84 select EDAC_ATOMIC_SCRUB 85 select EDAC_SUPPORT 86 select GENERIC_CLOCKEVENTS 87 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 88 select GENERIC_CLOCKEVENTS_MIN_ADJUST 89 select GENERIC_CMOS_UPDATE 90 select GENERIC_CPU_AUTOPROBE 91 select GENERIC_CPU_VULNERABILITIES 92 select GENERIC_EARLY_IOREMAP 93 select GENERIC_FIND_FIRST_BIT 94 select GENERIC_IOMAP 95 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 96 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 97 select GENERIC_IRQ_MIGRATION if SMP 98 select GENERIC_IRQ_PROBE 99 select GENERIC_IRQ_RESERVATION_MODE 100 select GENERIC_IRQ_SHOW 101 select GENERIC_PENDING_IRQ if SMP 102 select GENERIC_SMP_IDLE_THREAD 103 select GENERIC_STRNCPY_FROM_USER 104 select GENERIC_STRNLEN_USER 105 select GENERIC_TIME_VSYSCALL 106 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 107 select HAVE_ACPI_APEI if ACPI 108 select HAVE_ACPI_APEI_NMI if ACPI 109 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 110 select HAVE_ARCH_AUDITSYSCALL 111 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 112 select HAVE_ARCH_JUMP_LABEL 113 select HAVE_ARCH_KASAN if X86_64 114 select HAVE_ARCH_KGDB 115 select HAVE_ARCH_MMAP_RND_BITS if MMU 116 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 117 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 118 select HAVE_ARCH_SECCOMP_FILTER 119 select HAVE_ARCH_TRACEHOOK 120 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 121 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 122 select HAVE_ARCH_VMAP_STACK if X86_64 123 select HAVE_ARCH_WITHIN_STACK_FRAMES 124 select HAVE_CC_STACKPROTECTOR 125 select HAVE_CMPXCHG_DOUBLE 126 select HAVE_CMPXCHG_LOCAL 127 select HAVE_CONTEXT_TRACKING if X86_64 128 select HAVE_COPY_THREAD_TLS 129 select HAVE_C_RECORDMCOUNT 130 select HAVE_DEBUG_KMEMLEAK 131 select HAVE_DEBUG_STACKOVERFLOW 132 select HAVE_DMA_API_DEBUG 133 select HAVE_DMA_CONTIGUOUS 134 select HAVE_DYNAMIC_FTRACE 135 select HAVE_DYNAMIC_FTRACE_WITH_REGS 136 select HAVE_EBPF_JIT if X86_64 137 select HAVE_EFFICIENT_UNALIGNED_ACCESS 138 select HAVE_EXIT_THREAD 139 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 140 select HAVE_FTRACE_MCOUNT_RECORD 141 select HAVE_FUNCTION_GRAPH_TRACER 142 select HAVE_FUNCTION_TRACER 143 select HAVE_GCC_PLUGINS 144 select HAVE_HW_BREAKPOINT 145 select HAVE_IDE 146 select HAVE_IOREMAP_PROT 147 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 148 select HAVE_IRQ_TIME_ACCOUNTING 149 select HAVE_KERNEL_BZIP2 150 select HAVE_KERNEL_GZIP 151 select HAVE_KERNEL_LZ4 152 select HAVE_KERNEL_LZMA 153 select HAVE_KERNEL_LZO 154 select HAVE_KERNEL_XZ 155 select HAVE_KPROBES 156 select HAVE_KPROBES_ON_FTRACE 157 select HAVE_KRETPROBES 158 select HAVE_KVM 159 select HAVE_LIVEPATCH if X86_64 160 select HAVE_MEMBLOCK 161 select HAVE_MEMBLOCK_NODE_MAP 162 select HAVE_MIXED_BREAKPOINTS_REGS 163 select HAVE_MOD_ARCH_SPECIFIC 164 select HAVE_NMI 165 select HAVE_OPROFILE 166 select HAVE_OPTPROBES 167 select HAVE_PCSPKR_PLATFORM 168 select HAVE_PERF_EVENTS 169 select HAVE_PERF_EVENTS_NMI 170 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 171 select HAVE_PERF_REGS 172 select HAVE_PERF_USER_STACK_DUMP 173 select HAVE_RCU_TABLE_FREE 174 select HAVE_REGS_AND_STACK_ACCESS_API 175 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 176 select HAVE_STACK_VALIDATION if X86_64 177 select HAVE_SYSCALL_TRACEPOINTS 178 select HAVE_UNSTABLE_SCHED_CLOCK 179 select HAVE_USER_RETURN_NOTIFIER 180 select IRQ_FORCED_THREADING 181 select PCI_LOCKLESS_CONFIG 182 select PERF_EVENTS 183 select RTC_LIB 184 select RTC_MC146818_LIB 185 select SPARSE_IRQ 186 select SRCU 187 select SYSCTL_EXCEPTION_TRACE 188 select THREAD_INFO_IN_TASK 189 select USER_STACKTRACE_SUPPORT 190 select VIRT_TO_BUS 191 select X86_FEATURE_NAMES if PROC_FS 192 193config INSTRUCTION_DECODER 194 def_bool y 195 depends on KPROBES || PERF_EVENTS || UPROBES 196 197config OUTPUT_FORMAT 198 string 199 default "elf32-i386" if X86_32 200 default "elf64-x86-64" if X86_64 201 202config ARCH_DEFCONFIG 203 string 204 default "arch/x86/configs/i386_defconfig" if X86_32 205 default "arch/x86/configs/x86_64_defconfig" if X86_64 206 207config LOCKDEP_SUPPORT 208 def_bool y 209 210config STACKTRACE_SUPPORT 211 def_bool y 212 213config MMU 214 def_bool y 215 216config ARCH_MMAP_RND_BITS_MIN 217 default 28 if 64BIT 218 default 8 219 220config ARCH_MMAP_RND_BITS_MAX 221 default 32 if 64BIT 222 default 16 223 224config ARCH_MMAP_RND_COMPAT_BITS_MIN 225 default 8 226 227config ARCH_MMAP_RND_COMPAT_BITS_MAX 228 default 16 229 230config SBUS 231 bool 232 233config NEED_DMA_MAP_STATE 234 def_bool y 235 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 236 237config NEED_SG_DMA_LENGTH 238 def_bool y 239 240config GENERIC_ISA_DMA 241 def_bool y 242 depends on ISA_DMA_API 243 244config GENERIC_BUG 245 def_bool y 246 depends on BUG 247 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 248 249config GENERIC_BUG_RELATIVE_POINTERS 250 bool 251 252config GENERIC_HWEIGHT 253 def_bool y 254 255config ARCH_MAY_HAVE_PC_FDC 256 def_bool y 257 depends on ISA_DMA_API 258 259config RWSEM_XCHGADD_ALGORITHM 260 def_bool y 261 262config GENERIC_CALIBRATE_DELAY 263 def_bool y 264 265config ARCH_HAS_CPU_RELAX 266 def_bool y 267 268config ARCH_HAS_CACHE_LINE_SIZE 269 def_bool y 270 271config HAVE_SETUP_PER_CPU_AREA 272 def_bool y 273 274config NEED_PER_CPU_EMBED_FIRST_CHUNK 275 def_bool y 276 277config NEED_PER_CPU_PAGE_FIRST_CHUNK 278 def_bool y 279 280config ARCH_HIBERNATION_POSSIBLE 281 def_bool y 282 283config ARCH_SUSPEND_POSSIBLE 284 def_bool y 285 286config ARCH_WANT_HUGE_PMD_SHARE 287 def_bool y 288 289config ARCH_WANT_GENERAL_HUGETLB 290 def_bool y 291 292config ZONE_DMA32 293 def_bool y if X86_64 294 295config AUDIT_ARCH 296 def_bool y if X86_64 297 298config ARCH_SUPPORTS_OPTIMIZED_INLINING 299 def_bool y 300 301config ARCH_SUPPORTS_DEBUG_PAGEALLOC 302 def_bool y 303 304config KASAN_SHADOW_OFFSET 305 hex 306 depends on KASAN 307 default 0xdffffc0000000000 308 309config HAVE_INTEL_TXT 310 def_bool y 311 depends on INTEL_IOMMU && ACPI 312 313config X86_32_SMP 314 def_bool y 315 depends on X86_32 && SMP 316 317config X86_64_SMP 318 def_bool y 319 depends on X86_64 && SMP 320 321config X86_32_LAZY_GS 322 def_bool y 323 depends on X86_32 && !CC_STACKPROTECTOR 324 325config ARCH_SUPPORTS_UPROBES 326 def_bool y 327 328config FIX_EARLYCON_MEM 329 def_bool y 330 331config PGTABLE_LEVELS 332 int 333 default 5 if X86_5LEVEL 334 default 4 if X86_64 335 default 3 if X86_PAE 336 default 2 337 338source "init/Kconfig" 339source "kernel/Kconfig.freezer" 340 341menu "Processor type and features" 342 343config ZONE_DMA 344 bool "DMA memory allocation support" if EXPERT 345 default y 346 help 347 DMA memory allocation support allows devices with less than 32-bit 348 addressing to allocate within the first 16MB of address space. 349 Disable if no such devices will be used. 350 351 If unsure, say Y. 352 353config SMP 354 bool "Symmetric multi-processing support" 355 ---help--- 356 This enables support for systems with more than one CPU. If you have 357 a system with only one CPU, say N. If you have a system with more 358 than one CPU, say Y. 359 360 If you say N here, the kernel will run on uni- and multiprocessor 361 machines, but will use only one CPU of a multiprocessor machine. If 362 you say Y here, the kernel will run on many, but not all, 363 uniprocessor machines. On a uniprocessor machine, the kernel 364 will run faster if you say N here. 365 366 Note that if you say Y here and choose architecture "586" or 367 "Pentium" under "Processor family", the kernel will not work on 486 368 architectures. Similarly, multiprocessor kernels for the "PPro" 369 architecture may not work on all Pentium based boards. 370 371 People using multiprocessor machines who say Y here should also say 372 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 373 Management" code will be disabled if you say Y here. 374 375 See also <file:Documentation/x86/i386/IO-APIC.txt>, 376 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 377 <http://www.tldp.org/docs.html#howto>. 378 379 If you don't know what to do here, say N. 380 381config X86_FEATURE_NAMES 382 bool "Processor feature human-readable names" if EMBEDDED 383 default y 384 ---help--- 385 This option compiles in a table of x86 feature bits and corresponding 386 names. This is required to support /proc/cpuinfo and a few kernel 387 messages. You can disable this to save space, at the expense of 388 making those few kernel messages show numeric feature bits instead. 389 390 If in doubt, say Y. 391 392config X86_FAST_FEATURE_TESTS 393 bool "Fast CPU feature tests" if EMBEDDED 394 default y 395 ---help--- 396 Some fast-paths in the kernel depend on the capabilities of the CPU. 397 Say Y here for the kernel to patch in the appropriate code at runtime 398 based on the capabilities of the CPU. The infrastructure for patching 399 code at runtime takes up some additional space; space-constrained 400 embedded systems may wish to say N here to produce smaller, slightly 401 slower code. 402 403config X86_X2APIC 404 bool "Support x2apic" 405 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 406 ---help--- 407 This enables x2apic support on CPUs that have this feature. 408 409 This allows 32-bit apic IDs (so it can support very large systems), 410 and accesses the local apic via MSRs not via mmio. 411 412 If you don't know what to do here, say N. 413 414config X86_MPPARSE 415 bool "Enable MPS table" if ACPI || SFI 416 default y 417 depends on X86_LOCAL_APIC 418 ---help--- 419 For old smp systems that do not have proper acpi support. Newer systems 420 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 421 422config X86_BIGSMP 423 bool "Support for big SMP systems with more than 8 CPUs" 424 depends on X86_32 && SMP 425 ---help--- 426 This option is needed for the systems that have more than 8 CPUs 427 428config GOLDFISH 429 def_bool y 430 depends on X86_GOLDFISH 431 432config RETPOLINE 433 bool "Avoid speculative indirect branches in kernel" 434 default y 435 help 436 Compile kernel with the retpoline compiler options to guard against 437 kernel-to-user data leaks by avoiding speculative indirect 438 branches. Requires a compiler with -mindirect-branch=thunk-extern 439 support for full protection. The kernel may run slower. 440 441 Without compiler support, at least indirect branches in assembler 442 code are eliminated. Since this includes the syscall entry path, 443 it is not entirely pointless. 444 445config INTEL_RDT 446 bool "Intel Resource Director Technology support" 447 default n 448 depends on X86 && CPU_SUP_INTEL 449 select KERNFS 450 help 451 Select to enable resource allocation and monitoring which are 452 sub-features of Intel Resource Director Technology(RDT). More 453 information about RDT can be found in the Intel x86 454 Architecture Software Developer Manual. 455 456 Say N if unsure. 457 458if X86_32 459config X86_EXTENDED_PLATFORM 460 bool "Support for extended (non-PC) x86 platforms" 461 default y 462 ---help--- 463 If you disable this option then the kernel will only support 464 standard PC platforms. (which covers the vast majority of 465 systems out there.) 466 467 If you enable this option then you'll be able to select support 468 for the following (non-PC) 32 bit x86 platforms: 469 Goldfish (Android emulator) 470 AMD Elan 471 RDC R-321x SoC 472 SGI 320/540 (Visual Workstation) 473 STA2X11-based (e.g. Northville) 474 Moorestown MID devices 475 476 If you have one of these systems, or if you want to build a 477 generic distribution kernel, say Y here - otherwise say N. 478endif 479 480if X86_64 481config X86_EXTENDED_PLATFORM 482 bool "Support for extended (non-PC) x86 platforms" 483 default y 484 ---help--- 485 If you disable this option then the kernel will only support 486 standard PC platforms. (which covers the vast majority of 487 systems out there.) 488 489 If you enable this option then you'll be able to select support 490 for the following (non-PC) 64 bit x86 platforms: 491 Numascale NumaChip 492 ScaleMP vSMP 493 SGI Ultraviolet 494 495 If you have one of these systems, or if you want to build a 496 generic distribution kernel, say Y here - otherwise say N. 497endif 498# This is an alphabetically sorted list of 64 bit extended platforms 499# Please maintain the alphabetic order if and when there are additions 500config X86_NUMACHIP 501 bool "Numascale NumaChip" 502 depends on X86_64 503 depends on X86_EXTENDED_PLATFORM 504 depends on NUMA 505 depends on SMP 506 depends on X86_X2APIC 507 depends on PCI_MMCONFIG 508 ---help--- 509 Adds support for Numascale NumaChip large-SMP systems. Needed to 510 enable more than ~168 cores. 511 If you don't have one of these, you should say N here. 512 513config X86_VSMP 514 bool "ScaleMP vSMP" 515 select HYPERVISOR_GUEST 516 select PARAVIRT 517 depends on X86_64 && PCI 518 depends on X86_EXTENDED_PLATFORM 519 depends on SMP 520 ---help--- 521 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 522 supposed to run on these EM64T-based machines. Only choose this option 523 if you have one of these machines. 524 525config X86_UV 526 bool "SGI Ultraviolet" 527 depends on X86_64 528 depends on X86_EXTENDED_PLATFORM 529 depends on NUMA 530 depends on EFI 531 depends on X86_X2APIC 532 depends on PCI 533 ---help--- 534 This option is needed in order to support SGI Ultraviolet systems. 535 If you don't have one of these, you should say N here. 536 537# Following is an alphabetically sorted list of 32 bit extended platforms 538# Please maintain the alphabetic order if and when there are additions 539 540config X86_GOLDFISH 541 bool "Goldfish (Virtual Platform)" 542 depends on X86_EXTENDED_PLATFORM 543 ---help--- 544 Enable support for the Goldfish virtual platform used primarily 545 for Android development. Unless you are building for the Android 546 Goldfish emulator say N here. 547 548config X86_INTEL_CE 549 bool "CE4100 TV platform" 550 depends on PCI 551 depends on PCI_GODIRECT 552 depends on X86_IO_APIC 553 depends on X86_32 554 depends on X86_EXTENDED_PLATFORM 555 select X86_REBOOTFIXUPS 556 select OF 557 select OF_EARLY_FLATTREE 558 ---help--- 559 Select for the Intel CE media processor (CE4100) SOC. 560 This option compiles in support for the CE4100 SOC for settop 561 boxes and media devices. 562 563config X86_INTEL_MID 564 bool "Intel MID platform support" 565 depends on X86_EXTENDED_PLATFORM 566 depends on X86_PLATFORM_DEVICES 567 depends on PCI 568 depends on X86_64 || (PCI_GOANY && X86_32) 569 depends on X86_IO_APIC 570 select SFI 571 select I2C 572 select DW_APB_TIMER 573 select APB_TIMER 574 select INTEL_SCU_IPC 575 select MFD_INTEL_MSIC 576 ---help--- 577 Select to build a kernel capable of supporting Intel MID (Mobile 578 Internet Device) platform systems which do not have the PCI legacy 579 interfaces. If you are building for a PC class system say N here. 580 581 Intel MID platforms are based on an Intel processor and chipset which 582 consume less power than most of the x86 derivatives. 583 584config X86_INTEL_QUARK 585 bool "Intel Quark platform support" 586 depends on X86_32 587 depends on X86_EXTENDED_PLATFORM 588 depends on X86_PLATFORM_DEVICES 589 depends on X86_TSC 590 depends on PCI 591 depends on PCI_GOANY 592 depends on X86_IO_APIC 593 select IOSF_MBI 594 select INTEL_IMR 595 select COMMON_CLK 596 ---help--- 597 Select to include support for Quark X1000 SoC. 598 Say Y here if you have a Quark based system such as the Arduino 599 compatible Intel Galileo. 600 601config X86_INTEL_LPSS 602 bool "Intel Low Power Subsystem Support" 603 depends on X86 && ACPI 604 select COMMON_CLK 605 select PINCTRL 606 select IOSF_MBI 607 ---help--- 608 Select to build support for Intel Low Power Subsystem such as 609 found on Intel Lynxpoint PCH. Selecting this option enables 610 things like clock tree (common clock framework) and pincontrol 611 which are needed by the LPSS peripheral drivers. 612 613config X86_AMD_PLATFORM_DEVICE 614 bool "AMD ACPI2Platform devices support" 615 depends on ACPI 616 select COMMON_CLK 617 select PINCTRL 618 ---help--- 619 Select to interpret AMD specific ACPI device to platform device 620 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 621 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 622 implemented under PINCTRL subsystem. 623 624config IOSF_MBI 625 tristate "Intel SoC IOSF Sideband support for SoC platforms" 626 depends on PCI 627 ---help--- 628 This option enables sideband register access support for Intel SoC 629 platforms. On these platforms the IOSF sideband is used in lieu of 630 MSR's for some register accesses, mostly but not limited to thermal 631 and power. Drivers may query the availability of this device to 632 determine if they need the sideband in order to work on these 633 platforms. The sideband is available on the following SoC products. 634 This list is not meant to be exclusive. 635 - BayTrail 636 - Braswell 637 - Quark 638 639 You should say Y if you are running a kernel on one of these SoC's. 640 641config IOSF_MBI_DEBUG 642 bool "Enable IOSF sideband access through debugfs" 643 depends on IOSF_MBI && DEBUG_FS 644 ---help--- 645 Select this option to expose the IOSF sideband access registers (MCR, 646 MDR, MCRX) through debugfs to write and read register information from 647 different units on the SoC. This is most useful for obtaining device 648 state information for debug and analysis. As this is a general access 649 mechanism, users of this option would have specific knowledge of the 650 device they want to access. 651 652 If you don't require the option or are in doubt, say N. 653 654config X86_RDC321X 655 bool "RDC R-321x SoC" 656 depends on X86_32 657 depends on X86_EXTENDED_PLATFORM 658 select M486 659 select X86_REBOOTFIXUPS 660 ---help--- 661 This option is needed for RDC R-321x system-on-chip, also known 662 as R-8610-(G). 663 If you don't have one of these chips, you should say N here. 664 665config X86_32_NON_STANDARD 666 bool "Support non-standard 32-bit SMP architectures" 667 depends on X86_32 && SMP 668 depends on X86_EXTENDED_PLATFORM 669 ---help--- 670 This option compiles in the bigsmp and STA2X11 default 671 subarchitectures. It is intended for a generic binary 672 kernel. If you select them all, kernel will probe it one by 673 one and will fallback to default. 674 675# Alphabetically sorted list of Non standard 32 bit platforms 676 677config X86_SUPPORTS_MEMORY_FAILURE 678 def_bool y 679 # MCE code calls memory_failure(): 680 depends on X86_MCE 681 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 682 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 683 depends on X86_64 || !SPARSEMEM 684 select ARCH_SUPPORTS_MEMORY_FAILURE 685 686config STA2X11 687 bool "STA2X11 Companion Chip Support" 688 depends on X86_32_NON_STANDARD && PCI 689 select X86_DEV_DMA_OPS 690 select X86_DMA_REMAP 691 select SWIOTLB 692 select MFD_STA2X11 693 select GPIOLIB 694 default n 695 ---help--- 696 This adds support for boards based on the STA2X11 IO-Hub, 697 a.k.a. "ConneXt". The chip is used in place of the standard 698 PC chipset, so all "standard" peripherals are missing. If this 699 option is selected the kernel will still be able to boot on 700 standard PC machines. 701 702config X86_32_IRIS 703 tristate "Eurobraille/Iris poweroff module" 704 depends on X86_32 705 ---help--- 706 The Iris machines from EuroBraille do not have APM or ACPI support 707 to shut themselves down properly. A special I/O sequence is 708 needed to do so, which is what this module does at 709 kernel shutdown. 710 711 This is only for Iris machines from EuroBraille. 712 713 If unused, say N. 714 715config SCHED_OMIT_FRAME_POINTER 716 def_bool y 717 prompt "Single-depth WCHAN output" 718 depends on X86 719 ---help--- 720 Calculate simpler /proc/<PID>/wchan values. If this option 721 is disabled then wchan values will recurse back to the 722 caller function. This provides more accurate wchan values, 723 at the expense of slightly more scheduling overhead. 724 725 If in doubt, say "Y". 726 727menuconfig HYPERVISOR_GUEST 728 bool "Linux guest support" 729 ---help--- 730 Say Y here to enable options for running Linux under various hyper- 731 visors. This option enables basic hypervisor detection and platform 732 setup. 733 734 If you say N, all options in this submenu will be skipped and 735 disabled, and Linux guest support won't be built in. 736 737if HYPERVISOR_GUEST 738 739config PARAVIRT 740 bool "Enable paravirtualization code" 741 ---help--- 742 This changes the kernel so it can modify itself when it is run 743 under a hypervisor, potentially improving performance significantly 744 over full virtualization. However, when run without a hypervisor 745 the kernel is theoretically slower and slightly larger. 746 747config PARAVIRT_DEBUG 748 bool "paravirt-ops debugging" 749 depends on PARAVIRT && DEBUG_KERNEL 750 ---help--- 751 Enable to debug paravirt_ops internals. Specifically, BUG if 752 a paravirt_op is missing when it is called. 753 754config PARAVIRT_SPINLOCKS 755 bool "Paravirtualization layer for spinlocks" 756 depends on PARAVIRT && SMP 757 ---help--- 758 Paravirtualized spinlocks allow a pvops backend to replace the 759 spinlock implementation with something virtualization-friendly 760 (for example, block the virtual CPU rather than spinning). 761 762 It has a minimal impact on native kernels and gives a nice performance 763 benefit on paravirtualized KVM / Xen kernels. 764 765 If you are unsure how to answer this question, answer Y. 766 767config QUEUED_LOCK_STAT 768 bool "Paravirt queued spinlock statistics" 769 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 770 ---help--- 771 Enable the collection of statistical data on the slowpath 772 behavior of paravirtualized queued spinlocks and report 773 them on debugfs. 774 775source "arch/x86/xen/Kconfig" 776 777config KVM_GUEST 778 bool "KVM Guest support (including kvmclock)" 779 depends on PARAVIRT 780 select PARAVIRT_CLOCK 781 default y 782 ---help--- 783 This option enables various optimizations for running under the KVM 784 hypervisor. It includes a paravirtualized clock, so that instead 785 of relying on a PIT (or probably other) emulation by the 786 underlying device model, the host provides the guest with 787 timing infrastructure such as time of day, and system time 788 789config KVM_DEBUG_FS 790 bool "Enable debug information for KVM Guests in debugfs" 791 depends on KVM_GUEST && DEBUG_FS 792 default n 793 ---help--- 794 This option enables collection of various statistics for KVM guest. 795 Statistics are displayed in debugfs filesystem. Enabling this option 796 may incur significant overhead. 797 798config PARAVIRT_TIME_ACCOUNTING 799 bool "Paravirtual steal time accounting" 800 depends on PARAVIRT 801 default n 802 ---help--- 803 Select this option to enable fine granularity task steal time 804 accounting. Time spent executing other tasks in parallel with 805 the current vCPU is discounted from the vCPU power. To account for 806 that, there can be a small performance impact. 807 808 If in doubt, say N here. 809 810config PARAVIRT_CLOCK 811 bool 812 813endif #HYPERVISOR_GUEST 814 815config NO_BOOTMEM 816 def_bool y 817 818source "arch/x86/Kconfig.cpu" 819 820config HPET_TIMER 821 def_bool X86_64 822 prompt "HPET Timer Support" if X86_32 823 ---help--- 824 Use the IA-PC HPET (High Precision Event Timer) to manage 825 time in preference to the PIT and RTC, if a HPET is 826 present. 827 HPET is the next generation timer replacing legacy 8254s. 828 The HPET provides a stable time base on SMP 829 systems, unlike the TSC, but it is more expensive to access, 830 as it is off-chip. The interface used is documented 831 in the HPET spec, revision 1. 832 833 You can safely choose Y here. However, HPET will only be 834 activated if the platform and the BIOS support this feature. 835 Otherwise the 8254 will be used for timing services. 836 837 Choose N to continue using the legacy 8254 timer. 838 839config HPET_EMULATE_RTC 840 def_bool y 841 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 842 843config APB_TIMER 844 def_bool y if X86_INTEL_MID 845 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 846 select DW_APB_TIMER 847 depends on X86_INTEL_MID && SFI 848 help 849 APB timer is the replacement for 8254, HPET on X86 MID platforms. 850 The APBT provides a stable time base on SMP 851 systems, unlike the TSC, but it is more expensive to access, 852 as it is off-chip. APB timers are always running regardless of CPU 853 C states, they are used as per CPU clockevent device when possible. 854 855# Mark as expert because too many people got it wrong. 856# The code disables itself when not needed. 857config DMI 858 default y 859 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 860 bool "Enable DMI scanning" if EXPERT 861 ---help--- 862 Enabled scanning of DMI to identify machine quirks. Say Y 863 here unless you have verified that your setup is not 864 affected by entries in the DMI blacklist. Required by PNP 865 BIOS code. 866 867config GART_IOMMU 868 bool "Old AMD GART IOMMU support" 869 select SWIOTLB 870 depends on X86_64 && PCI && AMD_NB 871 ---help--- 872 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 873 GART based hardware IOMMUs. 874 875 The GART supports full DMA access for devices with 32-bit access 876 limitations, on systems with more than 3 GB. This is usually needed 877 for USB, sound, many IDE/SATA chipsets and some other devices. 878 879 Newer systems typically have a modern AMD IOMMU, supported via 880 the CONFIG_AMD_IOMMU=y config option. 881 882 In normal configurations this driver is only active when needed: 883 there's more than 3 GB of memory and the system contains a 884 32-bit limited device. 885 886 If unsure, say Y. 887 888config CALGARY_IOMMU 889 bool "IBM Calgary IOMMU support" 890 select SWIOTLB 891 depends on X86_64 && PCI 892 ---help--- 893 Support for hardware IOMMUs in IBM's xSeries x366 and x460 894 systems. Needed to run systems with more than 3GB of memory 895 properly with 32-bit PCI devices that do not support DAC 896 (Double Address Cycle). Calgary also supports bus level 897 isolation, where all DMAs pass through the IOMMU. This 898 prevents them from going anywhere except their intended 899 destination. This catches hard-to-find kernel bugs and 900 mis-behaving drivers and devices that do not use the DMA-API 901 properly to set up their DMA buffers. The IOMMU can be 902 turned off at boot time with the iommu=off parameter. 903 Normally the kernel will make the right choice by itself. 904 If unsure, say Y. 905 906config CALGARY_IOMMU_ENABLED_BY_DEFAULT 907 def_bool y 908 prompt "Should Calgary be enabled by default?" 909 depends on CALGARY_IOMMU 910 ---help--- 911 Should Calgary be enabled by default? if you choose 'y', Calgary 912 will be used (if it exists). If you choose 'n', Calgary will not be 913 used even if it exists. If you choose 'n' and would like to use 914 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 915 If unsure, say Y. 916 917# need this always selected by IOMMU for the VIA workaround 918config SWIOTLB 919 def_bool y if X86_64 920 ---help--- 921 Support for software bounce buffers used on x86-64 systems 922 which don't have a hardware IOMMU. Using this PCI devices 923 which can only access 32-bits of memory can be used on systems 924 with more than 3 GB of memory. 925 If unsure, say Y. 926 927config IOMMU_HELPER 928 def_bool y 929 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 930 931config MAXSMP 932 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 933 depends on X86_64 && SMP && DEBUG_KERNEL 934 select CPUMASK_OFFSTACK 935 ---help--- 936 Enable maximum number of CPUS and NUMA Nodes for this architecture. 937 If unsure, say N. 938 939config NR_CPUS 940 int "Maximum number of CPUs" if SMP && !MAXSMP 941 range 2 8 if SMP && X86_32 && !X86_BIGSMP 942 range 2 64 if SMP && X86_32 && X86_BIGSMP 943 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64 944 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 945 default "1" if !SMP 946 default "8192" if MAXSMP 947 default "32" if SMP && X86_BIGSMP 948 default "8" if SMP && X86_32 949 default "64" if SMP 950 ---help--- 951 This allows you to specify the maximum number of CPUs which this 952 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 953 supported value is 8192, otherwise the maximum value is 512. The 954 minimum value which makes sense is 2. 955 956 This is purely to save memory - each supported CPU adds 957 approximately eight kilobytes to the kernel image. 958 959config SCHED_SMT 960 bool "SMT (Hyperthreading) scheduler support" 961 depends on SMP 962 ---help--- 963 SMT scheduler support improves the CPU scheduler's decision making 964 when dealing with Intel Pentium 4 chips with HyperThreading at a 965 cost of slightly increased overhead in some places. If unsure say 966 N here. 967 968config SCHED_MC 969 def_bool y 970 prompt "Multi-core scheduler support" 971 depends on SMP 972 ---help--- 973 Multi-core scheduler support improves the CPU scheduler's decision 974 making when dealing with multi-core CPU chips at a cost of slightly 975 increased overhead in some places. If unsure say N here. 976 977config SCHED_MC_PRIO 978 bool "CPU core priorities scheduler support" 979 depends on SCHED_MC && CPU_SUP_INTEL 980 select X86_INTEL_PSTATE 981 select CPU_FREQ 982 default y 983 ---help--- 984 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 985 core ordering determined at manufacturing time, which allows 986 certain cores to reach higher turbo frequencies (when running 987 single threaded workloads) than others. 988 989 Enabling this kernel feature teaches the scheduler about 990 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 991 scheduler's CPU selection logic accordingly, so that higher 992 overall system performance can be achieved. 993 994 This feature will have no effect on CPUs without this feature. 995 996 If unsure say Y here. 997 998source "kernel/Kconfig.preempt" 999 1000config UP_LATE_INIT 1001 def_bool y 1002 depends on !SMP && X86_LOCAL_APIC 1003 1004config X86_UP_APIC 1005 bool "Local APIC support on uniprocessors" if !PCI_MSI 1006 default PCI_MSI 1007 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1008 ---help--- 1009 A local APIC (Advanced Programmable Interrupt Controller) is an 1010 integrated interrupt controller in the CPU. If you have a single-CPU 1011 system which has a processor with a local APIC, you can say Y here to 1012 enable and use it. If you say Y here even though your machine doesn't 1013 have a local APIC, then the kernel will still run with no slowdown at 1014 all. The local APIC supports CPU-generated self-interrupts (timer, 1015 performance counters), and the NMI watchdog which detects hard 1016 lockups. 1017 1018config X86_UP_IOAPIC 1019 bool "IO-APIC support on uniprocessors" 1020 depends on X86_UP_APIC 1021 ---help--- 1022 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1023 SMP-capable replacement for PC-style interrupt controllers. Most 1024 SMP systems and many recent uniprocessor systems have one. 1025 1026 If you have a single-CPU system with an IO-APIC, you can say Y here 1027 to use it. If you say Y here even though your machine doesn't have 1028 an IO-APIC, then the kernel will still run with no slowdown at all. 1029 1030config X86_LOCAL_APIC 1031 def_bool y 1032 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1033 select IRQ_DOMAIN_HIERARCHY 1034 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1035 1036config X86_IO_APIC 1037 def_bool y 1038 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1039 1040config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1041 bool "Reroute for broken boot IRQs" 1042 depends on X86_IO_APIC 1043 ---help--- 1044 This option enables a workaround that fixes a source of 1045 spurious interrupts. This is recommended when threaded 1046 interrupt handling is used on systems where the generation of 1047 superfluous "boot interrupts" cannot be disabled. 1048 1049 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1050 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1051 kernel does during interrupt handling). On chipsets where this 1052 boot IRQ generation cannot be disabled, this workaround keeps 1053 the original IRQ line masked so that only the equivalent "boot 1054 IRQ" is delivered to the CPUs. The workaround also tells the 1055 kernel to set up the IRQ handler on the boot IRQ line. In this 1056 way only one interrupt is delivered to the kernel. Otherwise 1057 the spurious second interrupt may cause the kernel to bring 1058 down (vital) interrupt lines. 1059 1060 Only affects "broken" chipsets. Interrupt sharing may be 1061 increased on these systems. 1062 1063config X86_MCE 1064 bool "Machine Check / overheating reporting" 1065 select GENERIC_ALLOCATOR 1066 default y 1067 ---help--- 1068 Machine Check support allows the processor to notify the 1069 kernel if it detects a problem (e.g. overheating, data corruption). 1070 The action the kernel takes depends on the severity of the problem, 1071 ranging from warning messages to halting the machine. 1072 1073config X86_MCELOG_LEGACY 1074 bool "Support for deprecated /dev/mcelog character device" 1075 depends on X86_MCE 1076 ---help--- 1077 Enable support for /dev/mcelog which is needed by the old mcelog 1078 userspace logging daemon. Consider switching to the new generation 1079 rasdaemon solution. 1080 1081config X86_MCE_INTEL 1082 def_bool y 1083 prompt "Intel MCE features" 1084 depends on X86_MCE && X86_LOCAL_APIC 1085 ---help--- 1086 Additional support for intel specific MCE features such as 1087 the thermal monitor. 1088 1089config X86_MCE_AMD 1090 def_bool y 1091 prompt "AMD MCE features" 1092 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1093 ---help--- 1094 Additional support for AMD specific MCE features such as 1095 the DRAM Error Threshold. 1096 1097config X86_ANCIENT_MCE 1098 bool "Support for old Pentium 5 / WinChip machine checks" 1099 depends on X86_32 && X86_MCE 1100 ---help--- 1101 Include support for machine check handling on old Pentium 5 or WinChip 1102 systems. These typically need to be enabled explicitly on the command 1103 line. 1104 1105config X86_MCE_THRESHOLD 1106 depends on X86_MCE_AMD || X86_MCE_INTEL 1107 def_bool y 1108 1109config X86_MCE_INJECT 1110 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1111 tristate "Machine check injector support" 1112 ---help--- 1113 Provide support for injecting machine checks for testing purposes. 1114 If you don't know what a machine check is and you don't do kernel 1115 QA it is safe to say n. 1116 1117config X86_THERMAL_VECTOR 1118 def_bool y 1119 depends on X86_MCE_INTEL 1120 1121source "arch/x86/events/Kconfig" 1122 1123config X86_LEGACY_VM86 1124 bool "Legacy VM86 support" 1125 default n 1126 depends on X86_32 1127 ---help--- 1128 This option allows user programs to put the CPU into V8086 1129 mode, which is an 80286-era approximation of 16-bit real mode. 1130 1131 Some very old versions of X and/or vbetool require this option 1132 for user mode setting. Similarly, DOSEMU will use it if 1133 available to accelerate real mode DOS programs. However, any 1134 recent version of DOSEMU, X, or vbetool should be fully 1135 functional even without kernel VM86 support, as they will all 1136 fall back to software emulation. Nevertheless, if you are using 1137 a 16-bit DOS program where 16-bit performance matters, vm86 1138 mode might be faster than emulation and you might want to 1139 enable this option. 1140 1141 Note that any app that works on a 64-bit kernel is unlikely to 1142 need this option, as 64-bit kernels don't, and can't, support 1143 V8086 mode. This option is also unrelated to 16-bit protected 1144 mode and is not needed to run most 16-bit programs under Wine. 1145 1146 Enabling this option increases the complexity of the kernel 1147 and slows down exception handling a tiny bit. 1148 1149 If unsure, say N here. 1150 1151config VM86 1152 bool 1153 default X86_LEGACY_VM86 1154 1155config X86_16BIT 1156 bool "Enable support for 16-bit segments" if EXPERT 1157 default y 1158 depends on MODIFY_LDT_SYSCALL 1159 ---help--- 1160 This option is required by programs like Wine to run 16-bit 1161 protected mode legacy code on x86 processors. Disabling 1162 this option saves about 300 bytes on i386, or around 6K text 1163 plus 16K runtime memory on x86-64, 1164 1165config X86_ESPFIX32 1166 def_bool y 1167 depends on X86_16BIT && X86_32 1168 1169config X86_ESPFIX64 1170 def_bool y 1171 depends on X86_16BIT && X86_64 1172 1173config X86_VSYSCALL_EMULATION 1174 bool "Enable vsyscall emulation" if EXPERT 1175 default y 1176 depends on X86_64 1177 ---help--- 1178 This enables emulation of the legacy vsyscall page. Disabling 1179 it is roughly equivalent to booting with vsyscall=none, except 1180 that it will also disable the helpful warning if a program 1181 tries to use a vsyscall. With this option set to N, offending 1182 programs will just segfault, citing addresses of the form 1183 0xffffffffff600?00. 1184 1185 This option is required by many programs built before 2013, and 1186 care should be used even with newer programs if set to N. 1187 1188 Disabling this option saves about 7K of kernel size and 1189 possibly 4K of additional runtime pagetable memory. 1190 1191config TOSHIBA 1192 tristate "Toshiba Laptop support" 1193 depends on X86_32 1194 ---help--- 1195 This adds a driver to safely access the System Management Mode of 1196 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1197 not work on models with a Phoenix BIOS. The System Management Mode 1198 is used to set the BIOS and power saving options on Toshiba portables. 1199 1200 For information on utilities to make use of this driver see the 1201 Toshiba Linux utilities web site at: 1202 <http://www.buzzard.org.uk/toshiba/>. 1203 1204 Say Y if you intend to run this kernel on a Toshiba portable. 1205 Say N otherwise. 1206 1207config I8K 1208 tristate "Dell i8k legacy laptop support" 1209 select HWMON 1210 select SENSORS_DELL_SMM 1211 ---help--- 1212 This option enables legacy /proc/i8k userspace interface in hwmon 1213 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1214 temperature and allows controlling fan speeds of Dell laptops via 1215 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1216 it reports also power and hotkey status. For fan speed control is 1217 needed userspace package i8kutils. 1218 1219 Say Y if you intend to run this kernel on old Dell laptops or want to 1220 use userspace package i8kutils. 1221 Say N otherwise. 1222 1223config X86_REBOOTFIXUPS 1224 bool "Enable X86 board specific fixups for reboot" 1225 depends on X86_32 1226 ---help--- 1227 This enables chipset and/or board specific fixups to be done 1228 in order to get reboot to work correctly. This is only needed on 1229 some combinations of hardware and BIOS. The symptom, for which 1230 this config is intended, is when reboot ends with a stalled/hung 1231 system. 1232 1233 Currently, the only fixup is for the Geode machines using 1234 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1235 1236 Say Y if you want to enable the fixup. Currently, it's safe to 1237 enable this option even if you don't need it. 1238 Say N otherwise. 1239 1240config MICROCODE 1241 bool "CPU microcode loading support" 1242 default y 1243 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1244 select FW_LOADER 1245 ---help--- 1246 If you say Y here, you will be able to update the microcode on 1247 Intel and AMD processors. The Intel support is for the IA32 family, 1248 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1249 AMD support is for families 0x10 and later. You will obviously need 1250 the actual microcode binary data itself which is not shipped with 1251 the Linux kernel. 1252 1253 The preferred method to load microcode from a detached initrd is described 1254 in Documentation/x86/early-microcode.txt. For that you need to enable 1255 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1256 initrd for microcode blobs. 1257 1258 In addition, you can build-in the microcode into the kernel. For that you 1259 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1260 to the CONFIG_EXTRA_FIRMWARE config option. 1261 1262config MICROCODE_INTEL 1263 bool "Intel microcode loading support" 1264 depends on MICROCODE 1265 default MICROCODE 1266 select FW_LOADER 1267 ---help--- 1268 This options enables microcode patch loading support for Intel 1269 processors. 1270 1271 For the current Intel microcode data package go to 1272 <https://downloadcenter.intel.com> and search for 1273 'Linux Processor Microcode Data File'. 1274 1275config MICROCODE_AMD 1276 bool "AMD microcode loading support" 1277 depends on MICROCODE 1278 select FW_LOADER 1279 ---help--- 1280 If you select this option, microcode patch loading support for AMD 1281 processors will be enabled. 1282 1283config MICROCODE_OLD_INTERFACE 1284 def_bool y 1285 depends on MICROCODE 1286 1287config X86_MSR 1288 tristate "/dev/cpu/*/msr - Model-specific register support" 1289 ---help--- 1290 This device gives privileged processes access to the x86 1291 Model-Specific Registers (MSRs). It is a character device with 1292 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1293 MSR accesses are directed to a specific CPU on multi-processor 1294 systems. 1295 1296config X86_CPUID 1297 tristate "/dev/cpu/*/cpuid - CPU information support" 1298 ---help--- 1299 This device gives processes access to the x86 CPUID instruction to 1300 be executed on a specific processor. It is a character device 1301 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1302 /dev/cpu/31/cpuid. 1303 1304choice 1305 prompt "High Memory Support" 1306 default HIGHMEM4G 1307 depends on X86_32 1308 1309config NOHIGHMEM 1310 bool "off" 1311 ---help--- 1312 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1313 However, the address space of 32-bit x86 processors is only 4 1314 Gigabytes large. That means that, if you have a large amount of 1315 physical memory, not all of it can be "permanently mapped" by the 1316 kernel. The physical memory that's not permanently mapped is called 1317 "high memory". 1318 1319 If you are compiling a kernel which will never run on a machine with 1320 more than 1 Gigabyte total physical RAM, answer "off" here (default 1321 choice and suitable for most users). This will result in a "3GB/1GB" 1322 split: 3GB are mapped so that each process sees a 3GB virtual memory 1323 space and the remaining part of the 4GB virtual memory space is used 1324 by the kernel to permanently map as much physical memory as 1325 possible. 1326 1327 If the machine has between 1 and 4 Gigabytes physical RAM, then 1328 answer "4GB" here. 1329 1330 If more than 4 Gigabytes is used then answer "64GB" here. This 1331 selection turns Intel PAE (Physical Address Extension) mode on. 1332 PAE implements 3-level paging on IA32 processors. PAE is fully 1333 supported by Linux, PAE mode is implemented on all recent Intel 1334 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1335 then the kernel will not boot on CPUs that don't support PAE! 1336 1337 The actual amount of total physical memory will either be 1338 auto detected or can be forced by using a kernel command line option 1339 such as "mem=256M". (Try "man bootparam" or see the documentation of 1340 your boot loader (lilo or loadlin) about how to pass options to the 1341 kernel at boot time.) 1342 1343 If unsure, say "off". 1344 1345config HIGHMEM4G 1346 bool "4GB" 1347 ---help--- 1348 Select this if you have a 32-bit processor and between 1 and 4 1349 gigabytes of physical RAM. 1350 1351config HIGHMEM64G 1352 bool "64GB" 1353 depends on !M486 1354 select X86_PAE 1355 ---help--- 1356 Select this if you have a 32-bit processor and more than 4 1357 gigabytes of physical RAM. 1358 1359endchoice 1360 1361choice 1362 prompt "Memory split" if EXPERT 1363 default VMSPLIT_3G 1364 depends on X86_32 1365 ---help--- 1366 Select the desired split between kernel and user memory. 1367 1368 If the address range available to the kernel is less than the 1369 physical memory installed, the remaining memory will be available 1370 as "high memory". Accessing high memory is a little more costly 1371 than low memory, as it needs to be mapped into the kernel first. 1372 Note that increasing the kernel address space limits the range 1373 available to user programs, making the address space there 1374 tighter. Selecting anything other than the default 3G/1G split 1375 will also likely make your kernel incompatible with binary-only 1376 kernel modules. 1377 1378 If you are not absolutely sure what you are doing, leave this 1379 option alone! 1380 1381 config VMSPLIT_3G 1382 bool "3G/1G user/kernel split" 1383 config VMSPLIT_3G_OPT 1384 depends on !X86_PAE 1385 bool "3G/1G user/kernel split (for full 1G low memory)" 1386 config VMSPLIT_2G 1387 bool "2G/2G user/kernel split" 1388 config VMSPLIT_2G_OPT 1389 depends on !X86_PAE 1390 bool "2G/2G user/kernel split (for full 2G low memory)" 1391 config VMSPLIT_1G 1392 bool "1G/3G user/kernel split" 1393endchoice 1394 1395config PAGE_OFFSET 1396 hex 1397 default 0xB0000000 if VMSPLIT_3G_OPT 1398 default 0x80000000 if VMSPLIT_2G 1399 default 0x78000000 if VMSPLIT_2G_OPT 1400 default 0x40000000 if VMSPLIT_1G 1401 default 0xC0000000 1402 depends on X86_32 1403 1404config HIGHMEM 1405 def_bool y 1406 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1407 1408config X86_PAE 1409 bool "PAE (Physical Address Extension) Support" 1410 depends on X86_32 && !HIGHMEM4G 1411 select SWIOTLB 1412 ---help--- 1413 PAE is required for NX support, and furthermore enables 1414 larger swapspace support for non-overcommit purposes. It 1415 has the cost of more pagetable lookup overhead, and also 1416 consumes more pagetable space per process. 1417 1418config X86_5LEVEL 1419 bool "Enable 5-level page tables support" 1420 depends on X86_64 1421 ---help--- 1422 5-level paging enables access to larger address space: 1423 upto 128 PiB of virtual address space and 4 PiB of 1424 physical address space. 1425 1426 It will be supported by future Intel CPUs. 1427 1428 Note: a kernel with this option enabled can only be booted 1429 on machines that support the feature. 1430 1431 See Documentation/x86/x86_64/5level-paging.txt for more 1432 information. 1433 1434 Say N if unsure. 1435 1436config ARCH_PHYS_ADDR_T_64BIT 1437 def_bool y 1438 depends on X86_64 || X86_PAE 1439 1440config ARCH_DMA_ADDR_T_64BIT 1441 def_bool y 1442 depends on X86_64 || HIGHMEM64G 1443 1444config X86_DIRECT_GBPAGES 1445 def_bool y 1446 depends on X86_64 && !DEBUG_PAGEALLOC 1447 ---help--- 1448 Certain kernel features effectively disable kernel 1449 linear 1 GB mappings (even if the CPU otherwise 1450 supports them), so don't confuse the user by printing 1451 that we have them enabled. 1452 1453config ARCH_HAS_MEM_ENCRYPT 1454 def_bool y 1455 1456config AMD_MEM_ENCRYPT 1457 bool "AMD Secure Memory Encryption (SME) support" 1458 depends on X86_64 && CPU_SUP_AMD 1459 ---help--- 1460 Say yes to enable support for the encryption of system memory. 1461 This requires an AMD processor that supports Secure Memory 1462 Encryption (SME). 1463 1464config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1465 bool "Activate AMD Secure Memory Encryption (SME) by default" 1466 default y 1467 depends on AMD_MEM_ENCRYPT 1468 ---help--- 1469 Say yes to have system memory encrypted by default if running on 1470 an AMD processor that supports Secure Memory Encryption (SME). 1471 1472 If set to Y, then the encryption of system memory can be 1473 deactivated with the mem_encrypt=off command line option. 1474 1475 If set to N, then the encryption of system memory can be 1476 activated with the mem_encrypt=on command line option. 1477 1478config ARCH_USE_MEMREMAP_PROT 1479 def_bool y 1480 depends on AMD_MEM_ENCRYPT 1481 1482# Common NUMA Features 1483config NUMA 1484 bool "Numa Memory Allocation and Scheduler Support" 1485 depends on SMP 1486 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1487 default y if X86_BIGSMP 1488 ---help--- 1489 Enable NUMA (Non Uniform Memory Access) support. 1490 1491 The kernel will try to allocate memory used by a CPU on the 1492 local memory controller of the CPU and add some more 1493 NUMA awareness to the kernel. 1494 1495 For 64-bit this is recommended if the system is Intel Core i7 1496 (or later), AMD Opteron, or EM64T NUMA. 1497 1498 For 32-bit this is only needed if you boot a 32-bit 1499 kernel on a 64-bit NUMA platform. 1500 1501 Otherwise, you should say N. 1502 1503config AMD_NUMA 1504 def_bool y 1505 prompt "Old style AMD Opteron NUMA detection" 1506 depends on X86_64 && NUMA && PCI 1507 ---help--- 1508 Enable AMD NUMA node topology detection. You should say Y here if 1509 you have a multi processor AMD system. This uses an old method to 1510 read the NUMA configuration directly from the builtin Northbridge 1511 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1512 which also takes priority if both are compiled in. 1513 1514config X86_64_ACPI_NUMA 1515 def_bool y 1516 prompt "ACPI NUMA detection" 1517 depends on X86_64 && NUMA && ACPI && PCI 1518 select ACPI_NUMA 1519 ---help--- 1520 Enable ACPI SRAT based node topology detection. 1521 1522# Some NUMA nodes have memory ranges that span 1523# other nodes. Even though a pfn is valid and 1524# between a node's start and end pfns, it may not 1525# reside on that node. See memmap_init_zone() 1526# for details. 1527config NODES_SPAN_OTHER_NODES 1528 def_bool y 1529 depends on X86_64_ACPI_NUMA 1530 1531config NUMA_EMU 1532 bool "NUMA emulation" 1533 depends on NUMA 1534 ---help--- 1535 Enable NUMA emulation. A flat machine will be split 1536 into virtual nodes when booted with "numa=fake=N", where N is the 1537 number of nodes. This is only useful for debugging. 1538 1539config NODES_SHIFT 1540 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1541 range 1 10 1542 default "10" if MAXSMP 1543 default "6" if X86_64 1544 default "3" 1545 depends on NEED_MULTIPLE_NODES 1546 ---help--- 1547 Specify the maximum number of NUMA Nodes available on the target 1548 system. Increases memory reserved to accommodate various tables. 1549 1550config ARCH_HAVE_MEMORY_PRESENT 1551 def_bool y 1552 depends on X86_32 && DISCONTIGMEM 1553 1554config NEED_NODE_MEMMAP_SIZE 1555 def_bool y 1556 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1557 1558config ARCH_FLATMEM_ENABLE 1559 def_bool y 1560 depends on X86_32 && !NUMA 1561 1562config ARCH_DISCONTIGMEM_ENABLE 1563 def_bool y 1564 depends on NUMA && X86_32 1565 1566config ARCH_DISCONTIGMEM_DEFAULT 1567 def_bool y 1568 depends on NUMA && X86_32 1569 1570config ARCH_SPARSEMEM_ENABLE 1571 def_bool y 1572 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1573 select SPARSEMEM_STATIC if X86_32 1574 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1575 1576config ARCH_SPARSEMEM_DEFAULT 1577 def_bool y 1578 depends on X86_64 1579 1580config ARCH_SELECT_MEMORY_MODEL 1581 def_bool y 1582 depends on ARCH_SPARSEMEM_ENABLE 1583 1584config ARCH_MEMORY_PROBE 1585 bool "Enable sysfs memory/probe interface" 1586 depends on X86_64 && MEMORY_HOTPLUG 1587 help 1588 This option enables a sysfs memory/probe interface for testing. 1589 See Documentation/memory-hotplug.txt for more information. 1590 If you are unsure how to answer this question, answer N. 1591 1592config ARCH_PROC_KCORE_TEXT 1593 def_bool y 1594 depends on X86_64 && PROC_KCORE 1595 1596config ILLEGAL_POINTER_VALUE 1597 hex 1598 default 0 if X86_32 1599 default 0xdead000000000000 if X86_64 1600 1601source "mm/Kconfig" 1602 1603config X86_PMEM_LEGACY_DEVICE 1604 bool 1605 1606config X86_PMEM_LEGACY 1607 tristate "Support non-standard NVDIMMs and ADR protected memory" 1608 depends on PHYS_ADDR_T_64BIT 1609 depends on BLK_DEV 1610 select X86_PMEM_LEGACY_DEVICE 1611 select LIBNVDIMM 1612 help 1613 Treat memory marked using the non-standard e820 type of 12 as used 1614 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1615 The kernel will offer these regions to the 'pmem' driver so 1616 they can be used for persistent storage. 1617 1618 Say Y if unsure. 1619 1620config HIGHPTE 1621 bool "Allocate 3rd-level pagetables from highmem" 1622 depends on HIGHMEM 1623 ---help--- 1624 The VM uses one page table entry for each page of physical memory. 1625 For systems with a lot of RAM, this can be wasteful of precious 1626 low memory. Setting this option will put user-space page table 1627 entries in high memory. 1628 1629config X86_CHECK_BIOS_CORRUPTION 1630 bool "Check for low memory corruption" 1631 ---help--- 1632 Periodically check for memory corruption in low memory, which 1633 is suspected to be caused by BIOS. Even when enabled in the 1634 configuration, it is disabled at runtime. Enable it by 1635 setting "memory_corruption_check=1" on the kernel command 1636 line. By default it scans the low 64k of memory every 60 1637 seconds; see the memory_corruption_check_size and 1638 memory_corruption_check_period parameters in 1639 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1640 1641 When enabled with the default parameters, this option has 1642 almost no overhead, as it reserves a relatively small amount 1643 of memory and scans it infrequently. It both detects corruption 1644 and prevents it from affecting the running system. 1645 1646 It is, however, intended as a diagnostic tool; if repeatable 1647 BIOS-originated corruption always affects the same memory, 1648 you can use memmap= to prevent the kernel from using that 1649 memory. 1650 1651config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1652 bool "Set the default setting of memory_corruption_check" 1653 depends on X86_CHECK_BIOS_CORRUPTION 1654 default y 1655 ---help--- 1656 Set whether the default state of memory_corruption_check is 1657 on or off. 1658 1659config X86_RESERVE_LOW 1660 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1661 default 64 1662 range 4 640 1663 ---help--- 1664 Specify the amount of low memory to reserve for the BIOS. 1665 1666 The first page contains BIOS data structures that the kernel 1667 must not use, so that page must always be reserved. 1668 1669 By default we reserve the first 64K of physical RAM, as a 1670 number of BIOSes are known to corrupt that memory range 1671 during events such as suspend/resume or monitor cable 1672 insertion, so it must not be used by the kernel. 1673 1674 You can set this to 4 if you are absolutely sure that you 1675 trust the BIOS to get all its memory reservations and usages 1676 right. If you know your BIOS have problems beyond the 1677 default 64K area, you can set this to 640 to avoid using the 1678 entire low memory range. 1679 1680 If you have doubts about the BIOS (e.g. suspend/resume does 1681 not work or there's kernel crashes after certain hardware 1682 hotplug events) then you might want to enable 1683 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1684 typical corruption patterns. 1685 1686 Leave this to the default value of 64 if you are unsure. 1687 1688config MATH_EMULATION 1689 bool 1690 depends on MODIFY_LDT_SYSCALL 1691 prompt "Math emulation" if X86_32 1692 ---help--- 1693 Linux can emulate a math coprocessor (used for floating point 1694 operations) if you don't have one. 486DX and Pentium processors have 1695 a math coprocessor built in, 486SX and 386 do not, unless you added 1696 a 487DX or 387, respectively. (The messages during boot time can 1697 give you some hints here ["man dmesg"].) Everyone needs either a 1698 coprocessor or this emulation. 1699 1700 If you don't have a math coprocessor, you need to say Y here; if you 1701 say Y here even though you have a coprocessor, the coprocessor will 1702 be used nevertheless. (This behavior can be changed with the kernel 1703 command line option "no387", which comes handy if your coprocessor 1704 is broken. Try "man bootparam" or see the documentation of your boot 1705 loader (lilo or loadlin) about how to pass options to the kernel at 1706 boot time.) This means that it is a good idea to say Y here if you 1707 intend to use this kernel on different machines. 1708 1709 More information about the internals of the Linux math coprocessor 1710 emulation can be found in <file:arch/x86/math-emu/README>. 1711 1712 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1713 kernel, it won't hurt. 1714 1715config MTRR 1716 def_bool y 1717 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1718 ---help--- 1719 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1720 the Memory Type Range Registers (MTRRs) may be used to control 1721 processor access to memory ranges. This is most useful if you have 1722 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1723 allows bus write transfers to be combined into a larger transfer 1724 before bursting over the PCI/AGP bus. This can increase performance 1725 of image write operations 2.5 times or more. Saying Y here creates a 1726 /proc/mtrr file which may be used to manipulate your processor's 1727 MTRRs. Typically the X server should use this. 1728 1729 This code has a reasonably generic interface so that similar 1730 control registers on other processors can be easily supported 1731 as well: 1732 1733 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1734 Registers (ARRs) which provide a similar functionality to MTRRs. For 1735 these, the ARRs are used to emulate the MTRRs. 1736 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1737 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1738 write-combining. All of these processors are supported by this code 1739 and it makes sense to say Y here if you have one of them. 1740 1741 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1742 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1743 can lead to all sorts of problems, so it's good to say Y here. 1744 1745 You can safely say Y even if your machine doesn't have MTRRs, you'll 1746 just add about 9 KB to your kernel. 1747 1748 See <file:Documentation/x86/mtrr.txt> for more information. 1749 1750config MTRR_SANITIZER 1751 def_bool y 1752 prompt "MTRR cleanup support" 1753 depends on MTRR 1754 ---help--- 1755 Convert MTRR layout from continuous to discrete, so X drivers can 1756 add writeback entries. 1757 1758 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1759 The largest mtrr entry size for a continuous block can be set with 1760 mtrr_chunk_size. 1761 1762 If unsure, say Y. 1763 1764config MTRR_SANITIZER_ENABLE_DEFAULT 1765 int "MTRR cleanup enable value (0-1)" 1766 range 0 1 1767 default "0" 1768 depends on MTRR_SANITIZER 1769 ---help--- 1770 Enable mtrr cleanup default value 1771 1772config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1773 int "MTRR cleanup spare reg num (0-7)" 1774 range 0 7 1775 default "1" 1776 depends on MTRR_SANITIZER 1777 ---help--- 1778 mtrr cleanup spare entries default, it can be changed via 1779 mtrr_spare_reg_nr=N on the kernel command line. 1780 1781config X86_PAT 1782 def_bool y 1783 prompt "x86 PAT support" if EXPERT 1784 depends on MTRR 1785 ---help--- 1786 Use PAT attributes to setup page level cache control. 1787 1788 PATs are the modern equivalents of MTRRs and are much more 1789 flexible than MTRRs. 1790 1791 Say N here if you see bootup problems (boot crash, boot hang, 1792 spontaneous reboots) or a non-working video driver. 1793 1794 If unsure, say Y. 1795 1796config ARCH_USES_PG_UNCACHED 1797 def_bool y 1798 depends on X86_PAT 1799 1800config ARCH_RANDOM 1801 def_bool y 1802 prompt "x86 architectural random number generator" if EXPERT 1803 ---help--- 1804 Enable the x86 architectural RDRAND instruction 1805 (Intel Bull Mountain technology) to generate random numbers. 1806 If supported, this is a high bandwidth, cryptographically 1807 secure hardware random number generator. 1808 1809config X86_SMAP 1810 def_bool y 1811 prompt "Supervisor Mode Access Prevention" if EXPERT 1812 ---help--- 1813 Supervisor Mode Access Prevention (SMAP) is a security 1814 feature in newer Intel processors. There is a small 1815 performance cost if this enabled and turned on; there is 1816 also a small increase in the kernel size if this is enabled. 1817 1818 If unsure, say Y. 1819 1820config X86_INTEL_UMIP 1821 def_bool y 1822 depends on CPU_SUP_INTEL 1823 prompt "Intel User Mode Instruction Prevention" if EXPERT 1824 ---help--- 1825 The User Mode Instruction Prevention (UMIP) is a security 1826 feature in newer Intel processors. If enabled, a general 1827 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1828 or STR instructions are executed in user mode. These instructions 1829 unnecessarily expose information about the hardware state. 1830 1831 The vast majority of applications do not use these instructions. 1832 For the very few that do, software emulation is provided in 1833 specific cases in protected and virtual-8086 modes. Emulated 1834 results are dummy. 1835 1836config X86_INTEL_MPX 1837 prompt "Intel MPX (Memory Protection Extensions)" 1838 def_bool n 1839 # Note: only available in 64-bit mode due to VMA flags shortage 1840 depends on CPU_SUP_INTEL && X86_64 1841 select ARCH_USES_HIGH_VMA_FLAGS 1842 ---help--- 1843 MPX provides hardware features that can be used in 1844 conjunction with compiler-instrumented code to check 1845 memory references. It is designed to detect buffer 1846 overflow or underflow bugs. 1847 1848 This option enables running applications which are 1849 instrumented or otherwise use MPX. It does not use MPX 1850 itself inside the kernel or to protect the kernel 1851 against bad memory references. 1852 1853 Enabling this option will make the kernel larger: 1854 ~8k of kernel text and 36 bytes of data on a 64-bit 1855 defconfig. It adds a long to the 'mm_struct' which 1856 will increase the kernel memory overhead of each 1857 process and adds some branches to paths used during 1858 exec() and munmap(). 1859 1860 For details, see Documentation/x86/intel_mpx.txt 1861 1862 If unsure, say N. 1863 1864config X86_INTEL_MEMORY_PROTECTION_KEYS 1865 prompt "Intel Memory Protection Keys" 1866 def_bool y 1867 # Note: only available in 64-bit mode 1868 depends on CPU_SUP_INTEL && X86_64 1869 select ARCH_USES_HIGH_VMA_FLAGS 1870 select ARCH_HAS_PKEYS 1871 ---help--- 1872 Memory Protection Keys provides a mechanism for enforcing 1873 page-based protections, but without requiring modification of the 1874 page tables when an application changes protection domains. 1875 1876 For details, see Documentation/x86/protection-keys.txt 1877 1878 If unsure, say y. 1879 1880config EFI 1881 bool "EFI runtime service support" 1882 depends on ACPI 1883 select UCS2_STRING 1884 select EFI_RUNTIME_WRAPPERS 1885 ---help--- 1886 This enables the kernel to use EFI runtime services that are 1887 available (such as the EFI variable services). 1888 1889 This option is only useful on systems that have EFI firmware. 1890 In addition, you should use the latest ELILO loader available 1891 at <http://elilo.sourceforge.net> in order to take advantage 1892 of EFI runtime services. However, even with this option, the 1893 resultant kernel should continue to boot on existing non-EFI 1894 platforms. 1895 1896config EFI_STUB 1897 bool "EFI stub support" 1898 depends on EFI && !X86_USE_3DNOW 1899 select RELOCATABLE 1900 ---help--- 1901 This kernel feature allows a bzImage to be loaded directly 1902 by EFI firmware without the use of a bootloader. 1903 1904 See Documentation/efi-stub.txt for more information. 1905 1906config EFI_MIXED 1907 bool "EFI mixed-mode support" 1908 depends on EFI_STUB && X86_64 1909 ---help--- 1910 Enabling this feature allows a 64-bit kernel to be booted 1911 on a 32-bit firmware, provided that your CPU supports 64-bit 1912 mode. 1913 1914 Note that it is not possible to boot a mixed-mode enabled 1915 kernel via the EFI boot stub - a bootloader that supports 1916 the EFI handover protocol must be used. 1917 1918 If unsure, say N. 1919 1920config SECCOMP 1921 def_bool y 1922 prompt "Enable seccomp to safely compute untrusted bytecode" 1923 ---help--- 1924 This kernel feature is useful for number crunching applications 1925 that may need to compute untrusted bytecode during their 1926 execution. By using pipes or other transports made available to 1927 the process as file descriptors supporting the read/write 1928 syscalls, it's possible to isolate those applications in 1929 their own address space using seccomp. Once seccomp is 1930 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1931 and the task is only allowed to execute a few safe syscalls 1932 defined by each seccomp mode. 1933 1934 If unsure, say Y. Only embedded should say N here. 1935 1936source kernel/Kconfig.hz 1937 1938config KEXEC 1939 bool "kexec system call" 1940 select KEXEC_CORE 1941 ---help--- 1942 kexec is a system call that implements the ability to shutdown your 1943 current kernel, and to start another kernel. It is like a reboot 1944 but it is independent of the system firmware. And like a reboot 1945 you can start any kernel with it, not just Linux. 1946 1947 The name comes from the similarity to the exec system call. 1948 1949 It is an ongoing process to be certain the hardware in a machine 1950 is properly shutdown, so do not be surprised if this code does not 1951 initially work for you. As of this writing the exact hardware 1952 interface is strongly in flux, so no good recommendation can be 1953 made. 1954 1955config KEXEC_FILE 1956 bool "kexec file based system call" 1957 select KEXEC_CORE 1958 select BUILD_BIN2C 1959 depends on X86_64 1960 depends on CRYPTO=y 1961 depends on CRYPTO_SHA256=y 1962 ---help--- 1963 This is new version of kexec system call. This system call is 1964 file based and takes file descriptors as system call argument 1965 for kernel and initramfs as opposed to list of segments as 1966 accepted by previous system call. 1967 1968config KEXEC_VERIFY_SIG 1969 bool "Verify kernel signature during kexec_file_load() syscall" 1970 depends on KEXEC_FILE 1971 ---help--- 1972 This option makes kernel signature verification mandatory for 1973 the kexec_file_load() syscall. 1974 1975 In addition to that option, you need to enable signature 1976 verification for the corresponding kernel image type being 1977 loaded in order for this to work. 1978 1979config KEXEC_BZIMAGE_VERIFY_SIG 1980 bool "Enable bzImage signature verification support" 1981 depends on KEXEC_VERIFY_SIG 1982 depends on SIGNED_PE_FILE_VERIFICATION 1983 select SYSTEM_TRUSTED_KEYRING 1984 ---help--- 1985 Enable bzImage signature verification support. 1986 1987config CRASH_DUMP 1988 bool "kernel crash dumps" 1989 depends on X86_64 || (X86_32 && HIGHMEM) 1990 ---help--- 1991 Generate crash dump after being started by kexec. 1992 This should be normally only set in special crash dump kernels 1993 which are loaded in the main kernel with kexec-tools into 1994 a specially reserved region and then later executed after 1995 a crash by kdump/kexec. The crash dump kernel must be compiled 1996 to a memory address not used by the main kernel or BIOS using 1997 PHYSICAL_START, or it must be built as a relocatable image 1998 (CONFIG_RELOCATABLE=y). 1999 For more details see Documentation/kdump/kdump.txt 2000 2001config KEXEC_JUMP 2002 bool "kexec jump" 2003 depends on KEXEC && HIBERNATION 2004 ---help--- 2005 Jump between original kernel and kexeced kernel and invoke 2006 code in physical address mode via KEXEC 2007 2008config PHYSICAL_START 2009 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2010 default "0x1000000" 2011 ---help--- 2012 This gives the physical address where the kernel is loaded. 2013 2014 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2015 bzImage will decompress itself to above physical address and 2016 run from there. Otherwise, bzImage will run from the address where 2017 it has been loaded by the boot loader and will ignore above physical 2018 address. 2019 2020 In normal kdump cases one does not have to set/change this option 2021 as now bzImage can be compiled as a completely relocatable image 2022 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2023 address. This option is mainly useful for the folks who don't want 2024 to use a bzImage for capturing the crash dump and want to use a 2025 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2026 to be specifically compiled to run from a specific memory area 2027 (normally a reserved region) and this option comes handy. 2028 2029 So if you are using bzImage for capturing the crash dump, 2030 leave the value here unchanged to 0x1000000 and set 2031 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2032 for capturing the crash dump change this value to start of 2033 the reserved region. In other words, it can be set based on 2034 the "X" value as specified in the "crashkernel=YM@XM" 2035 command line boot parameter passed to the panic-ed 2036 kernel. Please take a look at Documentation/kdump/kdump.txt 2037 for more details about crash dumps. 2038 2039 Usage of bzImage for capturing the crash dump is recommended as 2040 one does not have to build two kernels. Same kernel can be used 2041 as production kernel and capture kernel. Above option should have 2042 gone away after relocatable bzImage support is introduced. But it 2043 is present because there are users out there who continue to use 2044 vmlinux for dump capture. This option should go away down the 2045 line. 2046 2047 Don't change this unless you know what you are doing. 2048 2049config RELOCATABLE 2050 bool "Build a relocatable kernel" 2051 default y 2052 ---help--- 2053 This builds a kernel image that retains relocation information 2054 so it can be loaded someplace besides the default 1MB. 2055 The relocations tend to make the kernel binary about 10% larger, 2056 but are discarded at runtime. 2057 2058 One use is for the kexec on panic case where the recovery kernel 2059 must live at a different physical address than the primary 2060 kernel. 2061 2062 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2063 it has been loaded at and the compile time physical address 2064 (CONFIG_PHYSICAL_START) is used as the minimum location. 2065 2066config RANDOMIZE_BASE 2067 bool "Randomize the address of the kernel image (KASLR)" 2068 depends on RELOCATABLE 2069 default y 2070 ---help--- 2071 In support of Kernel Address Space Layout Randomization (KASLR), 2072 this randomizes the physical address at which the kernel image 2073 is decompressed and the virtual address where the kernel 2074 image is mapped, as a security feature that deters exploit 2075 attempts relying on knowledge of the location of kernel 2076 code internals. 2077 2078 On 64-bit, the kernel physical and virtual addresses are 2079 randomized separately. The physical address will be anywhere 2080 between 16MB and the top of physical memory (up to 64TB). The 2081 virtual address will be randomized from 16MB up to 1GB (9 bits 2082 of entropy). Note that this also reduces the memory space 2083 available to kernel modules from 1.5GB to 1GB. 2084 2085 On 32-bit, the kernel physical and virtual addresses are 2086 randomized together. They will be randomized from 16MB up to 2087 512MB (8 bits of entropy). 2088 2089 Entropy is generated using the RDRAND instruction if it is 2090 supported. If RDTSC is supported, its value is mixed into 2091 the entropy pool as well. If neither RDRAND nor RDTSC are 2092 supported, then entropy is read from the i8254 timer. The 2093 usable entropy is limited by the kernel being built using 2094 2GB addressing, and that PHYSICAL_ALIGN must be at a 2095 minimum of 2MB. As a result, only 10 bits of entropy are 2096 theoretically possible, but the implementations are further 2097 limited due to memory layouts. 2098 2099 If unsure, say Y. 2100 2101# Relocation on x86 needs some additional build support 2102config X86_NEED_RELOCS 2103 def_bool y 2104 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2105 2106config PHYSICAL_ALIGN 2107 hex "Alignment value to which kernel should be aligned" 2108 default "0x200000" 2109 range 0x2000 0x1000000 if X86_32 2110 range 0x200000 0x1000000 if X86_64 2111 ---help--- 2112 This value puts the alignment restrictions on physical address 2113 where kernel is loaded and run from. Kernel is compiled for an 2114 address which meets above alignment restriction. 2115 2116 If bootloader loads the kernel at a non-aligned address and 2117 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2118 address aligned to above value and run from there. 2119 2120 If bootloader loads the kernel at a non-aligned address and 2121 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2122 load address and decompress itself to the address it has been 2123 compiled for and run from there. The address for which kernel is 2124 compiled already meets above alignment restrictions. Hence the 2125 end result is that kernel runs from a physical address meeting 2126 above alignment restrictions. 2127 2128 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2129 this value must be a multiple of 0x200000. 2130 2131 Don't change this unless you know what you are doing. 2132 2133config RANDOMIZE_MEMORY 2134 bool "Randomize the kernel memory sections" 2135 depends on X86_64 2136 depends on RANDOMIZE_BASE 2137 default RANDOMIZE_BASE 2138 ---help--- 2139 Randomizes the base virtual address of kernel memory sections 2140 (physical memory mapping, vmalloc & vmemmap). This security feature 2141 makes exploits relying on predictable memory locations less reliable. 2142 2143 The order of allocations remains unchanged. Entropy is generated in 2144 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2145 configuration have in average 30,000 different possible virtual 2146 addresses for each memory section. 2147 2148 If unsure, say Y. 2149 2150config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2151 hex "Physical memory mapping padding" if EXPERT 2152 depends on RANDOMIZE_MEMORY 2153 default "0xa" if MEMORY_HOTPLUG 2154 default "0x0" 2155 range 0x1 0x40 if MEMORY_HOTPLUG 2156 range 0x0 0x40 2157 ---help--- 2158 Define the padding in terabytes added to the existing physical 2159 memory size during kernel memory randomization. It is useful 2160 for memory hotplug support but reduces the entropy available for 2161 address randomization. 2162 2163 If unsure, leave at the default value. 2164 2165config HOTPLUG_CPU 2166 bool "Support for hot-pluggable CPUs" 2167 depends on SMP 2168 ---help--- 2169 Say Y here to allow turning CPUs off and on. CPUs can be 2170 controlled through /sys/devices/system/cpu. 2171 ( Note: power management support will enable this option 2172 automatically on SMP systems. ) 2173 Say N if you want to disable CPU hotplug. 2174 2175config BOOTPARAM_HOTPLUG_CPU0 2176 bool "Set default setting of cpu0_hotpluggable" 2177 default n 2178 depends on HOTPLUG_CPU 2179 ---help--- 2180 Set whether default state of cpu0_hotpluggable is on or off. 2181 2182 Say Y here to enable CPU0 hotplug by default. If this switch 2183 is turned on, there is no need to give cpu0_hotplug kernel 2184 parameter and the CPU0 hotplug feature is enabled by default. 2185 2186 Please note: there are two known CPU0 dependencies if you want 2187 to enable the CPU0 hotplug feature either by this switch or by 2188 cpu0_hotplug kernel parameter. 2189 2190 First, resume from hibernate or suspend always starts from CPU0. 2191 So hibernate and suspend are prevented if CPU0 is offline. 2192 2193 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2194 offline if any interrupt can not migrate out of CPU0. There may 2195 be other CPU0 dependencies. 2196 2197 Please make sure the dependencies are under your control before 2198 you enable this feature. 2199 2200 Say N if you don't want to enable CPU0 hotplug feature by default. 2201 You still can enable the CPU0 hotplug feature at boot by kernel 2202 parameter cpu0_hotplug. 2203 2204config DEBUG_HOTPLUG_CPU0 2205 def_bool n 2206 prompt "Debug CPU0 hotplug" 2207 depends on HOTPLUG_CPU 2208 ---help--- 2209 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2210 soon as possible and boots up userspace with CPU0 offlined. User 2211 can online CPU0 back after boot time. 2212 2213 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2214 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2215 compilation or giving cpu0_hotplug kernel parameter at boot. 2216 2217 If unsure, say N. 2218 2219config COMPAT_VDSO 2220 def_bool n 2221 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2222 depends on COMPAT_32 2223 ---help--- 2224 Certain buggy versions of glibc will crash if they are 2225 presented with a 32-bit vDSO that is not mapped at the address 2226 indicated in its segment table. 2227 2228 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2229 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2230 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2231 the only released version with the bug, but OpenSUSE 9 2232 contains a buggy "glibc 2.3.2". 2233 2234 The symptom of the bug is that everything crashes on startup, saying: 2235 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2236 2237 Saying Y here changes the default value of the vdso32 boot 2238 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2239 This works around the glibc bug but hurts performance. 2240 2241 If unsure, say N: if you are compiling your own kernel, you 2242 are unlikely to be using a buggy version of glibc. 2243 2244choice 2245 prompt "vsyscall table for legacy applications" 2246 depends on X86_64 2247 default LEGACY_VSYSCALL_EMULATE 2248 help 2249 Legacy user code that does not know how to find the vDSO expects 2250 to be able to issue three syscalls by calling fixed addresses in 2251 kernel space. Since this location is not randomized with ASLR, 2252 it can be used to assist security vulnerability exploitation. 2253 2254 This setting can be changed at boot time via the kernel command 2255 line parameter vsyscall=[native|emulate|none]. 2256 2257 On a system with recent enough glibc (2.14 or newer) and no 2258 static binaries, you can say None without a performance penalty 2259 to improve security. 2260 2261 If unsure, select "Emulate". 2262 2263 config LEGACY_VSYSCALL_NATIVE 2264 bool "Native" 2265 help 2266 Actual executable code is located in the fixed vsyscall 2267 address mapping, implementing time() efficiently. Since 2268 this makes the mapping executable, it can be used during 2269 security vulnerability exploitation (traditionally as 2270 ROP gadgets). This configuration is not recommended. 2271 2272 config LEGACY_VSYSCALL_EMULATE 2273 bool "Emulate" 2274 help 2275 The kernel traps and emulates calls into the fixed 2276 vsyscall address mapping. This makes the mapping 2277 non-executable, but it still contains known contents, 2278 which could be used in certain rare security vulnerability 2279 exploits. This configuration is recommended when userspace 2280 still uses the vsyscall area. 2281 2282 config LEGACY_VSYSCALL_NONE 2283 bool "None" 2284 help 2285 There will be no vsyscall mapping at all. This will 2286 eliminate any risk of ASLR bypass due to the vsyscall 2287 fixed address mapping. Attempts to use the vsyscalls 2288 will be reported to dmesg, so that either old or 2289 malicious userspace programs can be identified. 2290 2291endchoice 2292 2293config CMDLINE_BOOL 2294 bool "Built-in kernel command line" 2295 ---help--- 2296 Allow for specifying boot arguments to the kernel at 2297 build time. On some systems (e.g. embedded ones), it is 2298 necessary or convenient to provide some or all of the 2299 kernel boot arguments with the kernel itself (that is, 2300 to not rely on the boot loader to provide them.) 2301 2302 To compile command line arguments into the kernel, 2303 set this option to 'Y', then fill in the 2304 boot arguments in CONFIG_CMDLINE. 2305 2306 Systems with fully functional boot loaders (i.e. non-embedded) 2307 should leave this option set to 'N'. 2308 2309config CMDLINE 2310 string "Built-in kernel command string" 2311 depends on CMDLINE_BOOL 2312 default "" 2313 ---help--- 2314 Enter arguments here that should be compiled into the kernel 2315 image and used at boot time. If the boot loader provides a 2316 command line at boot time, it is appended to this string to 2317 form the full kernel command line, when the system boots. 2318 2319 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2320 change this behavior. 2321 2322 In most cases, the command line (whether built-in or provided 2323 by the boot loader) should specify the device for the root 2324 file system. 2325 2326config CMDLINE_OVERRIDE 2327 bool "Built-in command line overrides boot loader arguments" 2328 depends on CMDLINE_BOOL 2329 ---help--- 2330 Set this option to 'Y' to have the kernel ignore the boot loader 2331 command line, and use ONLY the built-in command line. 2332 2333 This is used to work around broken boot loaders. This should 2334 be set to 'N' under normal conditions. 2335 2336config MODIFY_LDT_SYSCALL 2337 bool "Enable the LDT (local descriptor table)" if EXPERT 2338 default y 2339 ---help--- 2340 Linux can allow user programs to install a per-process x86 2341 Local Descriptor Table (LDT) using the modify_ldt(2) system 2342 call. This is required to run 16-bit or segmented code such as 2343 DOSEMU or some Wine programs. It is also used by some very old 2344 threading libraries. 2345 2346 Enabling this feature adds a small amount of overhead to 2347 context switches and increases the low-level kernel attack 2348 surface. Disabling it removes the modify_ldt(2) system call. 2349 2350 Saying 'N' here may make sense for embedded or server kernels. 2351 2352source "kernel/livepatch/Kconfig" 2353 2354endmenu 2355 2356config ARCH_HAS_ADD_PAGES 2357 def_bool y 2358 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2359 2360config ARCH_ENABLE_MEMORY_HOTPLUG 2361 def_bool y 2362 depends on X86_64 || (X86_32 && HIGHMEM) 2363 2364config ARCH_ENABLE_MEMORY_HOTREMOVE 2365 def_bool y 2366 depends on MEMORY_HOTPLUG 2367 2368config USE_PERCPU_NUMA_NODE_ID 2369 def_bool y 2370 depends on NUMA 2371 2372config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2373 def_bool y 2374 depends on X86_64 || X86_PAE 2375 2376config ARCH_ENABLE_HUGEPAGE_MIGRATION 2377 def_bool y 2378 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2379 2380config ARCH_ENABLE_THP_MIGRATION 2381 def_bool y 2382 depends on X86_64 && TRANSPARENT_HUGEPAGE 2383 2384menu "Power management and ACPI options" 2385 2386config ARCH_HIBERNATION_HEADER 2387 def_bool y 2388 depends on X86_64 && HIBERNATION 2389 2390source "kernel/power/Kconfig" 2391 2392source "drivers/acpi/Kconfig" 2393 2394source "drivers/sfi/Kconfig" 2395 2396config X86_APM_BOOT 2397 def_bool y 2398 depends on APM 2399 2400menuconfig APM 2401 tristate "APM (Advanced Power Management) BIOS support" 2402 depends on X86_32 && PM_SLEEP 2403 ---help--- 2404 APM is a BIOS specification for saving power using several different 2405 techniques. This is mostly useful for battery powered laptops with 2406 APM compliant BIOSes. If you say Y here, the system time will be 2407 reset after a RESUME operation, the /proc/apm device will provide 2408 battery status information, and user-space programs will receive 2409 notification of APM "events" (e.g. battery status change). 2410 2411 If you select "Y" here, you can disable actual use of the APM 2412 BIOS by passing the "apm=off" option to the kernel at boot time. 2413 2414 Note that the APM support is almost completely disabled for 2415 machines with more than one CPU. 2416 2417 In order to use APM, you will need supporting software. For location 2418 and more information, read <file:Documentation/power/apm-acpi.txt> 2419 and the Battery Powered Linux mini-HOWTO, available from 2420 <http://www.tldp.org/docs.html#howto>. 2421 2422 This driver does not spin down disk drives (see the hdparm(8) 2423 manpage ("man 8 hdparm") for that), and it doesn't turn off 2424 VESA-compliant "green" monitors. 2425 2426 This driver does not support the TI 4000M TravelMate and the ACER 2427 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2428 desktop machines also don't have compliant BIOSes, and this driver 2429 may cause those machines to panic during the boot phase. 2430 2431 Generally, if you don't have a battery in your machine, there isn't 2432 much point in using this driver and you should say N. If you get 2433 random kernel OOPSes or reboots that don't seem to be related to 2434 anything, try disabling/enabling this option (or disabling/enabling 2435 APM in your BIOS). 2436 2437 Some other things you should try when experiencing seemingly random, 2438 "weird" problems: 2439 2440 1) make sure that you have enough swap space and that it is 2441 enabled. 2442 2) pass the "no-hlt" option to the kernel 2443 3) switch on floating point emulation in the kernel and pass 2444 the "no387" option to the kernel 2445 4) pass the "floppy=nodma" option to the kernel 2446 5) pass the "mem=4M" option to the kernel (thereby disabling 2447 all but the first 4 MB of RAM) 2448 6) make sure that the CPU is not over clocked. 2449 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2450 8) disable the cache from your BIOS settings 2451 9) install a fan for the video card or exchange video RAM 2452 10) install a better fan for the CPU 2453 11) exchange RAM chips 2454 12) exchange the motherboard. 2455 2456 To compile this driver as a module, choose M here: the 2457 module will be called apm. 2458 2459if APM 2460 2461config APM_IGNORE_USER_SUSPEND 2462 bool "Ignore USER SUSPEND" 2463 ---help--- 2464 This option will ignore USER SUSPEND requests. On machines with a 2465 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2466 series notebooks, it is necessary to say Y because of a BIOS bug. 2467 2468config APM_DO_ENABLE 2469 bool "Enable PM at boot time" 2470 ---help--- 2471 Enable APM features at boot time. From page 36 of the APM BIOS 2472 specification: "When disabled, the APM BIOS does not automatically 2473 power manage devices, enter the Standby State, enter the Suspend 2474 State, or take power saving steps in response to CPU Idle calls." 2475 This driver will make CPU Idle calls when Linux is idle (unless this 2476 feature is turned off -- see "Do CPU IDLE calls", below). This 2477 should always save battery power, but more complicated APM features 2478 will be dependent on your BIOS implementation. You may need to turn 2479 this option off if your computer hangs at boot time when using APM 2480 support, or if it beeps continuously instead of suspending. Turn 2481 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2482 T400CDT. This is off by default since most machines do fine without 2483 this feature. 2484 2485config APM_CPU_IDLE 2486 depends on CPU_IDLE 2487 bool "Make CPU Idle calls when idle" 2488 ---help--- 2489 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2490 On some machines, this can activate improved power savings, such as 2491 a slowed CPU clock rate, when the machine is idle. These idle calls 2492 are made after the idle loop has run for some length of time (e.g., 2493 333 mS). On some machines, this will cause a hang at boot time or 2494 whenever the CPU becomes idle. (On machines with more than one CPU, 2495 this option does nothing.) 2496 2497config APM_DISPLAY_BLANK 2498 bool "Enable console blanking using APM" 2499 ---help--- 2500 Enable console blanking using the APM. Some laptops can use this to 2501 turn off the LCD backlight when the screen blanker of the Linux 2502 virtual console blanks the screen. Note that this is only used by 2503 the virtual console screen blanker, and won't turn off the backlight 2504 when using the X Window system. This also doesn't have anything to 2505 do with your VESA-compliant power-saving monitor. Further, this 2506 option doesn't work for all laptops -- it might not turn off your 2507 backlight at all, or it might print a lot of errors to the console, 2508 especially if you are using gpm. 2509 2510config APM_ALLOW_INTS 2511 bool "Allow interrupts during APM BIOS calls" 2512 ---help--- 2513 Normally we disable external interrupts while we are making calls to 2514 the APM BIOS as a measure to lessen the effects of a badly behaving 2515 BIOS implementation. The BIOS should reenable interrupts if it 2516 needs to. Unfortunately, some BIOSes do not -- especially those in 2517 many of the newer IBM Thinkpads. If you experience hangs when you 2518 suspend, try setting this to Y. Otherwise, say N. 2519 2520endif # APM 2521 2522source "drivers/cpufreq/Kconfig" 2523 2524source "drivers/cpuidle/Kconfig" 2525 2526source "drivers/idle/Kconfig" 2527 2528endmenu 2529 2530 2531menu "Bus options (PCI etc.)" 2532 2533config PCI 2534 bool "PCI support" 2535 default y 2536 ---help--- 2537 Find out whether you have a PCI motherboard. PCI is the name of a 2538 bus system, i.e. the way the CPU talks to the other stuff inside 2539 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2540 VESA. If you have PCI, say Y, otherwise N. 2541 2542choice 2543 prompt "PCI access mode" 2544 depends on X86_32 && PCI 2545 default PCI_GOANY 2546 ---help--- 2547 On PCI systems, the BIOS can be used to detect the PCI devices and 2548 determine their configuration. However, some old PCI motherboards 2549 have BIOS bugs and may crash if this is done. Also, some embedded 2550 PCI-based systems don't have any BIOS at all. Linux can also try to 2551 detect the PCI hardware directly without using the BIOS. 2552 2553 With this option, you can specify how Linux should detect the 2554 PCI devices. If you choose "BIOS", the BIOS will be used, 2555 if you choose "Direct", the BIOS won't be used, and if you 2556 choose "MMConfig", then PCI Express MMCONFIG will be used. 2557 If you choose "Any", the kernel will try MMCONFIG, then the 2558 direct access method and falls back to the BIOS if that doesn't 2559 work. If unsure, go with the default, which is "Any". 2560 2561config PCI_GOBIOS 2562 bool "BIOS" 2563 2564config PCI_GOMMCONFIG 2565 bool "MMConfig" 2566 2567config PCI_GODIRECT 2568 bool "Direct" 2569 2570config PCI_GOOLPC 2571 bool "OLPC XO-1" 2572 depends on OLPC 2573 2574config PCI_GOANY 2575 bool "Any" 2576 2577endchoice 2578 2579config PCI_BIOS 2580 def_bool y 2581 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2582 2583# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2584config PCI_DIRECT 2585 def_bool y 2586 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2587 2588config PCI_MMCONFIG 2589 def_bool y 2590 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2591 2592config PCI_OLPC 2593 def_bool y 2594 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2595 2596config PCI_XEN 2597 def_bool y 2598 depends on PCI && XEN 2599 select SWIOTLB_XEN 2600 2601config PCI_DOMAINS 2602 def_bool y 2603 depends on PCI 2604 2605config PCI_MMCONFIG 2606 bool "Support mmconfig PCI config space access" 2607 depends on X86_64 && PCI && ACPI 2608 2609config PCI_CNB20LE_QUIRK 2610 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2611 depends on PCI 2612 help 2613 Read the PCI windows out of the CNB20LE host bridge. This allows 2614 PCI hotplug to work on systems with the CNB20LE chipset which do 2615 not have ACPI. 2616 2617 There's no public spec for this chipset, and this functionality 2618 is known to be incomplete. 2619 2620 You should say N unless you know you need this. 2621 2622source "drivers/pci/Kconfig" 2623 2624config ISA_BUS 2625 bool "ISA-style bus support on modern systems" if EXPERT 2626 select ISA_BUS_API 2627 help 2628 Enables ISA-style drivers on modern systems. This is necessary to 2629 support PC/104 devices on X86_64 platforms. 2630 2631 If unsure, say N. 2632 2633# x86_64 have no ISA slots, but can have ISA-style DMA. 2634config ISA_DMA_API 2635 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2636 default y 2637 help 2638 Enables ISA-style DMA support for devices requiring such controllers. 2639 If unsure, say Y. 2640 2641if X86_32 2642 2643config ISA 2644 bool "ISA support" 2645 ---help--- 2646 Find out whether you have ISA slots on your motherboard. ISA is the 2647 name of a bus system, i.e. the way the CPU talks to the other stuff 2648 inside your box. Other bus systems are PCI, EISA, MicroChannel 2649 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2650 newer boards don't support it. If you have ISA, say Y, otherwise N. 2651 2652config EISA 2653 bool "EISA support" 2654 depends on ISA 2655 ---help--- 2656 The Extended Industry Standard Architecture (EISA) bus was 2657 developed as an open alternative to the IBM MicroChannel bus. 2658 2659 The EISA bus provided some of the features of the IBM MicroChannel 2660 bus while maintaining backward compatibility with cards made for 2661 the older ISA bus. The EISA bus saw limited use between 1988 and 2662 1995 when it was made obsolete by the PCI bus. 2663 2664 Say Y here if you are building a kernel for an EISA-based machine. 2665 2666 Otherwise, say N. 2667 2668source "drivers/eisa/Kconfig" 2669 2670config SCx200 2671 tristate "NatSemi SCx200 support" 2672 ---help--- 2673 This provides basic support for National Semiconductor's 2674 (now AMD's) Geode processors. The driver probes for the 2675 PCI-IDs of several on-chip devices, so its a good dependency 2676 for other scx200_* drivers. 2677 2678 If compiled as a module, the driver is named scx200. 2679 2680config SCx200HR_TIMER 2681 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2682 depends on SCx200 2683 default y 2684 ---help--- 2685 This driver provides a clocksource built upon the on-chip 2686 27MHz high-resolution timer. Its also a workaround for 2687 NSC Geode SC-1100's buggy TSC, which loses time when the 2688 processor goes idle (as is done by the scheduler). The 2689 other workaround is idle=poll boot option. 2690 2691config OLPC 2692 bool "One Laptop Per Child support" 2693 depends on !X86_PAE 2694 select GPIOLIB 2695 select OF 2696 select OF_PROMTREE 2697 select IRQ_DOMAIN 2698 ---help--- 2699 Add support for detecting the unique features of the OLPC 2700 XO hardware. 2701 2702config OLPC_XO1_PM 2703 bool "OLPC XO-1 Power Management" 2704 depends on OLPC && MFD_CS5535 && PM_SLEEP 2705 select MFD_CORE 2706 ---help--- 2707 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2708 2709config OLPC_XO1_RTC 2710 bool "OLPC XO-1 Real Time Clock" 2711 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2712 ---help--- 2713 Add support for the XO-1 real time clock, which can be used as a 2714 programmable wakeup source. 2715 2716config OLPC_XO1_SCI 2717 bool "OLPC XO-1 SCI extras" 2718 depends on OLPC && OLPC_XO1_PM 2719 depends on INPUT=y 2720 select POWER_SUPPLY 2721 select GPIO_CS5535 2722 select MFD_CORE 2723 ---help--- 2724 Add support for SCI-based features of the OLPC XO-1 laptop: 2725 - EC-driven system wakeups 2726 - Power button 2727 - Ebook switch 2728 - Lid switch 2729 - AC adapter status updates 2730 - Battery status updates 2731 2732config OLPC_XO15_SCI 2733 bool "OLPC XO-1.5 SCI extras" 2734 depends on OLPC && ACPI 2735 select POWER_SUPPLY 2736 ---help--- 2737 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2738 - EC-driven system wakeups 2739 - AC adapter status updates 2740 - Battery status updates 2741 2742config ALIX 2743 bool "PCEngines ALIX System Support (LED setup)" 2744 select GPIOLIB 2745 ---help--- 2746 This option enables system support for the PCEngines ALIX. 2747 At present this just sets up LEDs for GPIO control on 2748 ALIX2/3/6 boards. However, other system specific setup should 2749 get added here. 2750 2751 Note: You must still enable the drivers for GPIO and LED support 2752 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2753 2754 Note: You have to set alix.force=1 for boards with Award BIOS. 2755 2756config NET5501 2757 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2758 select GPIOLIB 2759 ---help--- 2760 This option enables system support for the Soekris Engineering net5501. 2761 2762config GEOS 2763 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2764 select GPIOLIB 2765 depends on DMI 2766 ---help--- 2767 This option enables system support for the Traverse Technologies GEOS. 2768 2769config TS5500 2770 bool "Technologic Systems TS-5500 platform support" 2771 depends on MELAN 2772 select CHECK_SIGNATURE 2773 select NEW_LEDS 2774 select LEDS_CLASS 2775 ---help--- 2776 This option enables system support for the Technologic Systems TS-5500. 2777 2778endif # X86_32 2779 2780config AMD_NB 2781 def_bool y 2782 depends on CPU_SUP_AMD && PCI 2783 2784source "drivers/pcmcia/Kconfig" 2785 2786config RAPIDIO 2787 tristate "RapidIO support" 2788 depends on PCI 2789 default n 2790 help 2791 If enabled this option will include drivers and the core 2792 infrastructure code to support RapidIO interconnect devices. 2793 2794source "drivers/rapidio/Kconfig" 2795 2796config X86_SYSFB 2797 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2798 help 2799 Firmwares often provide initial graphics framebuffers so the BIOS, 2800 bootloader or kernel can show basic video-output during boot for 2801 user-guidance and debugging. Historically, x86 used the VESA BIOS 2802 Extensions and EFI-framebuffers for this, which are mostly limited 2803 to x86. 2804 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2805 framebuffers so the new generic system-framebuffer drivers can be 2806 used on x86. If the framebuffer is not compatible with the generic 2807 modes, it is adverticed as fallback platform framebuffer so legacy 2808 drivers like efifb, vesafb and uvesafb can pick it up. 2809 If this option is not selected, all system framebuffers are always 2810 marked as fallback platform framebuffers as usual. 2811 2812 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2813 not be able to pick up generic system framebuffers if this option 2814 is selected. You are highly encouraged to enable simplefb as 2815 replacement if you select this option. simplefb can correctly deal 2816 with generic system framebuffers. But you should still keep vesafb 2817 and others enabled as fallback if a system framebuffer is 2818 incompatible with simplefb. 2819 2820 If unsure, say Y. 2821 2822endmenu 2823 2824 2825menu "Executable file formats / Emulations" 2826 2827source "fs/Kconfig.binfmt" 2828 2829config IA32_EMULATION 2830 bool "IA32 Emulation" 2831 depends on X86_64 2832 select ARCH_WANT_OLD_COMPAT_IPC 2833 select BINFMT_ELF 2834 select COMPAT_BINFMT_ELF 2835 select COMPAT_OLD_SIGACTION 2836 ---help--- 2837 Include code to run legacy 32-bit programs under a 2838 64-bit kernel. You should likely turn this on, unless you're 2839 100% sure that you don't have any 32-bit programs left. 2840 2841config IA32_AOUT 2842 tristate "IA32 a.out support" 2843 depends on IA32_EMULATION 2844 ---help--- 2845 Support old a.out binaries in the 32bit emulation. 2846 2847config X86_X32 2848 bool "x32 ABI for 64-bit mode" 2849 depends on X86_64 2850 ---help--- 2851 Include code to run binaries for the x32 native 32-bit ABI 2852 for 64-bit processors. An x32 process gets access to the 2853 full 64-bit register file and wide data path while leaving 2854 pointers at 32 bits for smaller memory footprint. 2855 2856 You will need a recent binutils (2.22 or later) with 2857 elf32_x86_64 support enabled to compile a kernel with this 2858 option set. 2859 2860config COMPAT_32 2861 def_bool y 2862 depends on IA32_EMULATION || X86_32 2863 select HAVE_UID16 2864 select OLD_SIGSUSPEND3 2865 2866config COMPAT 2867 def_bool y 2868 depends on IA32_EMULATION || X86_X32 2869 2870if COMPAT 2871config COMPAT_FOR_U64_ALIGNMENT 2872 def_bool y 2873 2874config SYSVIPC_COMPAT 2875 def_bool y 2876 depends on SYSVIPC 2877endif 2878 2879endmenu 2880 2881 2882config HAVE_ATOMIC_IOMAP 2883 def_bool y 2884 depends on X86_32 2885 2886config X86_DEV_DMA_OPS 2887 bool 2888 depends on X86_64 || STA2X11 2889 2890config X86_DMA_REMAP 2891 bool 2892 depends on STA2X11 2893 2894config HAVE_GENERIC_GUP 2895 def_bool y 2896 2897source "net/Kconfig" 2898 2899source "drivers/Kconfig" 2900 2901source "drivers/firmware/Kconfig" 2902 2903source "fs/Kconfig" 2904 2905source "arch/x86/Kconfig.debug" 2906 2907source "security/Kconfig" 2908 2909source "crypto/Kconfig" 2910 2911source "arch/x86/kvm/Kconfig" 2912 2913source "lib/Kconfig" 2914