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_GENERIC_DMA_COHERENT 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 21config X86_64 22 def_bool y 23 depends on 64BIT 24 # Options that are inherently 64-bit kernel only: 25 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 26 select ARCH_SUPPORTS_INT128 27 select ARCH_USE_CMPXCHG_LOCKREF 28 select HAVE_ARCH_SOFT_DIRTY 29 select MODULES_USE_ELF_RELA 30 select NEED_DMA_MAP_STATE 31 select SWIOTLB 32 select X86_DEV_DMA_OPS 33 select ARCH_HAS_SYSCALL_WRAPPER 34 35# 36# Arch settings 37# 38# ( Note that options that are marked 'if X86_64' could in principle be 39# ported to 32-bit as well. ) 40# 41config X86 42 def_bool y 43 # 44 # Note: keep this list sorted alphabetically 45 # 46 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 47 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 48 select ANON_INODES 49 select ARCH_32BIT_OFF_T if X86_32 50 select ARCH_CLOCKSOURCE_DATA 51 select ARCH_CLOCKSOURCE_INIT 52 select ARCH_DISCARD_MEMBLOCK 53 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 54 select ARCH_HAS_DEBUG_VIRTUAL 55 select ARCH_HAS_DEVMEM_IS_ALLOWED 56 select ARCH_HAS_ELF_RANDOMIZE 57 select ARCH_HAS_FAST_MULTIPLIER 58 select ARCH_HAS_FILTER_PGPROT 59 select ARCH_HAS_FORTIFY_SOURCE 60 select ARCH_HAS_GCOV_PROFILE_ALL 61 select ARCH_HAS_KCOV if X86_64 62 select ARCH_HAS_MEMBARRIER_SYNC_CORE 63 select ARCH_HAS_PMEM_API if X86_64 64 select ARCH_HAS_PTE_SPECIAL 65 select ARCH_HAS_REFCOUNT 66 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 67 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 68 select ARCH_HAS_SET_MEMORY 69 select ARCH_HAS_STRICT_KERNEL_RWX 70 select ARCH_HAS_STRICT_MODULE_RWX 71 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 72 select ARCH_HAS_UBSAN_SANITIZE_ALL 73 select ARCH_HAS_ZONE_DEVICE if X86_64 74 select ARCH_HAVE_NMI_SAFE_CMPXCHG 75 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 76 select ARCH_MIGHT_HAVE_PC_PARPORT 77 select ARCH_MIGHT_HAVE_PC_SERIO 78 select ARCH_SUPPORTS_ACPI 79 select ARCH_SUPPORTS_ATOMIC_RMW 80 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 81 select ARCH_USE_BUILTIN_BSWAP 82 select ARCH_USE_QUEUED_RWLOCKS 83 select ARCH_USE_QUEUED_SPINLOCKS 84 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 85 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 86 select ARCH_WANTS_THP_SWAP if X86_64 87 select BUILDTIME_EXTABLE_SORT 88 select CLKEVT_I8253 89 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 90 select CLOCKSOURCE_WATCHDOG 91 select DCACHE_WORD_ACCESS 92 select EDAC_ATOMIC_SCRUB 93 select EDAC_SUPPORT 94 select GENERIC_CLOCKEVENTS 95 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 96 select GENERIC_CLOCKEVENTS_MIN_ADJUST 97 select GENERIC_CMOS_UPDATE 98 select GENERIC_CPU_AUTOPROBE 99 select GENERIC_CPU_VULNERABILITIES 100 select GENERIC_EARLY_IOREMAP 101 select GENERIC_FIND_FIRST_BIT 102 select GENERIC_IOMAP 103 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 104 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 105 select GENERIC_IRQ_MIGRATION if SMP 106 select GENERIC_IRQ_PROBE 107 select GENERIC_IRQ_RESERVATION_MODE 108 select GENERIC_IRQ_SHOW 109 select GENERIC_PENDING_IRQ if SMP 110 select GENERIC_SMP_IDLE_THREAD 111 select GENERIC_STRNCPY_FROM_USER 112 select GENERIC_STRNLEN_USER 113 select GENERIC_TIME_VSYSCALL 114 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 115 select HAVE_ACPI_APEI if ACPI 116 select HAVE_ACPI_APEI_NMI if ACPI 117 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 118 select HAVE_ARCH_AUDITSYSCALL 119 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 120 select HAVE_ARCH_JUMP_LABEL 121 select HAVE_ARCH_JUMP_LABEL_RELATIVE 122 select HAVE_ARCH_KASAN if X86_64 123 select HAVE_ARCH_KGDB 124 select HAVE_ARCH_MMAP_RND_BITS if MMU 125 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 126 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 127 select HAVE_ARCH_PREL32_RELOCATIONS 128 select HAVE_ARCH_SECCOMP_FILTER 129 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 130 select HAVE_ARCH_STACKLEAK 131 select HAVE_ARCH_TRACEHOOK 132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 133 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 134 select HAVE_ARCH_VMAP_STACK if X86_64 135 select HAVE_ARCH_WITHIN_STACK_FRAMES 136 select HAVE_CMPXCHG_DOUBLE 137 select HAVE_CMPXCHG_LOCAL 138 select HAVE_CONTEXT_TRACKING if X86_64 139 select HAVE_COPY_THREAD_TLS 140 select HAVE_C_RECORDMCOUNT 141 select HAVE_DEBUG_KMEMLEAK 142 select HAVE_DEBUG_STACKOVERFLOW 143 select HAVE_DMA_CONTIGUOUS 144 select HAVE_DYNAMIC_FTRACE 145 select HAVE_DYNAMIC_FTRACE_WITH_REGS 146 select HAVE_EBPF_JIT 147 select HAVE_EFFICIENT_UNALIGNED_ACCESS 148 select HAVE_EISA 149 select HAVE_EXIT_THREAD 150 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 151 select HAVE_FTRACE_MCOUNT_RECORD 152 select HAVE_FUNCTION_GRAPH_TRACER 153 select HAVE_FUNCTION_TRACER 154 select HAVE_GCC_PLUGINS 155 select HAVE_HW_BREAKPOINT 156 select HAVE_IDE 157 select HAVE_IOREMAP_PROT 158 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 159 select HAVE_IRQ_TIME_ACCOUNTING 160 select HAVE_KERNEL_BZIP2 161 select HAVE_KERNEL_GZIP 162 select HAVE_KERNEL_LZ4 163 select HAVE_KERNEL_LZMA 164 select HAVE_KERNEL_LZO 165 select HAVE_KERNEL_XZ 166 select HAVE_KPROBES 167 select HAVE_KPROBES_ON_FTRACE 168 select HAVE_FUNCTION_ERROR_INJECTION 169 select HAVE_KRETPROBES 170 select HAVE_KVM 171 select HAVE_LIVEPATCH if X86_64 172 select HAVE_MEMBLOCK_NODE_MAP 173 select HAVE_MIXED_BREAKPOINTS_REGS 174 select HAVE_MOD_ARCH_SPECIFIC 175 select HAVE_MOVE_PMD 176 select HAVE_NMI 177 select HAVE_OPROFILE 178 select HAVE_OPTPROBES 179 select HAVE_PCSPKR_PLATFORM 180 select HAVE_PERF_EVENTS 181 select HAVE_PERF_EVENTS_NMI 182 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 183 select HAVE_PCI 184 select HAVE_PERF_REGS 185 select HAVE_PERF_USER_STACK_DUMP 186 select HAVE_RCU_TABLE_FREE if PARAVIRT 187 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 188 select HAVE_REGS_AND_STACK_ACCESS_API 189 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 190 select HAVE_FUNCTION_ARG_ACCESS_API 191 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 192 select HAVE_STACK_VALIDATION if X86_64 193 select HAVE_RSEQ 194 select HAVE_SYSCALL_TRACEPOINTS 195 select HAVE_UNSTABLE_SCHED_CLOCK 196 select HAVE_USER_RETURN_NOTIFIER 197 select HOTPLUG_SMT if SMP 198 select IRQ_FORCED_THREADING 199 select NEED_SG_DMA_LENGTH 200 select PCI_DOMAINS if PCI 201 select PCI_LOCKLESS_CONFIG if PCI 202 select PERF_EVENTS 203 select RTC_LIB 204 select RTC_MC146818_LIB 205 select SPARSE_IRQ 206 select SRCU 207 select SYSCTL_EXCEPTION_TRACE 208 select THREAD_INFO_IN_TASK 209 select USER_STACKTRACE_SUPPORT 210 select VIRT_TO_BUS 211 select X86_FEATURE_NAMES if PROC_FS 212 213config INSTRUCTION_DECODER 214 def_bool y 215 depends on KPROBES || PERF_EVENTS || UPROBES 216 217config OUTPUT_FORMAT 218 string 219 default "elf32-i386" if X86_32 220 default "elf64-x86-64" if X86_64 221 222config ARCH_DEFCONFIG 223 string 224 default "arch/x86/configs/i386_defconfig" if X86_32 225 default "arch/x86/configs/x86_64_defconfig" if X86_64 226 227config LOCKDEP_SUPPORT 228 def_bool y 229 230config STACKTRACE_SUPPORT 231 def_bool y 232 233config MMU 234 def_bool y 235 236config ARCH_MMAP_RND_BITS_MIN 237 default 28 if 64BIT 238 default 8 239 240config ARCH_MMAP_RND_BITS_MAX 241 default 32 if 64BIT 242 default 16 243 244config ARCH_MMAP_RND_COMPAT_BITS_MIN 245 default 8 246 247config ARCH_MMAP_RND_COMPAT_BITS_MAX 248 default 16 249 250config SBUS 251 bool 252 253config GENERIC_ISA_DMA 254 def_bool y 255 depends on ISA_DMA_API 256 257config GENERIC_BUG 258 def_bool y 259 depends on BUG 260 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 261 262config GENERIC_BUG_RELATIVE_POINTERS 263 bool 264 265config GENERIC_HWEIGHT 266 def_bool y 267 268config ARCH_MAY_HAVE_PC_FDC 269 def_bool y 270 depends on ISA_DMA_API 271 272config RWSEM_XCHGADD_ALGORITHM 273 def_bool y 274 275config GENERIC_CALIBRATE_DELAY 276 def_bool y 277 278config ARCH_HAS_CPU_RELAX 279 def_bool y 280 281config ARCH_HAS_CACHE_LINE_SIZE 282 def_bool y 283 284config ARCH_HAS_FILTER_PGPROT 285 def_bool y 286 287config HAVE_SETUP_PER_CPU_AREA 288 def_bool y 289 290config NEED_PER_CPU_EMBED_FIRST_CHUNK 291 def_bool y 292 293config NEED_PER_CPU_PAGE_FIRST_CHUNK 294 def_bool y 295 296config ARCH_HIBERNATION_POSSIBLE 297 def_bool y 298 299config ARCH_SUSPEND_POSSIBLE 300 def_bool y 301 302config ARCH_WANT_HUGE_PMD_SHARE 303 def_bool y 304 305config ARCH_WANT_GENERAL_HUGETLB 306 def_bool y 307 308config ZONE_DMA32 309 def_bool y if X86_64 310 311config AUDIT_ARCH 312 def_bool y if X86_64 313 314config ARCH_SUPPORTS_OPTIMIZED_INLINING 315 def_bool y 316 317config ARCH_SUPPORTS_DEBUG_PAGEALLOC 318 def_bool y 319 320config KASAN_SHADOW_OFFSET 321 hex 322 depends on KASAN 323 default 0xdffffc0000000000 324 325config HAVE_INTEL_TXT 326 def_bool y 327 depends on INTEL_IOMMU && ACPI 328 329config X86_32_SMP 330 def_bool y 331 depends on X86_32 && SMP 332 333config X86_64_SMP 334 def_bool y 335 depends on X86_64 && SMP 336 337config X86_32_LAZY_GS 338 def_bool y 339 depends on X86_32 && !STACKPROTECTOR 340 341config ARCH_SUPPORTS_UPROBES 342 def_bool y 343 344config FIX_EARLYCON_MEM 345 def_bool y 346 347config DYNAMIC_PHYSICAL_MASK 348 bool 349 350config PGTABLE_LEVELS 351 int 352 default 5 if X86_5LEVEL 353 default 4 if X86_64 354 default 3 if X86_PAE 355 default 2 356 357config CC_HAS_SANE_STACKPROTECTOR 358 bool 359 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 360 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 361 help 362 We have to make sure stack protector is unconditionally disabled if 363 the compiler produces broken code. 364 365menu "Processor type and features" 366 367config ZONE_DMA 368 bool "DMA memory allocation support" if EXPERT 369 default y 370 help 371 DMA memory allocation support allows devices with less than 32-bit 372 addressing to allocate within the first 16MB of address space. 373 Disable if no such devices will be used. 374 375 If unsure, say Y. 376 377config SMP 378 bool "Symmetric multi-processing support" 379 ---help--- 380 This enables support for systems with more than one CPU. If you have 381 a system with only one CPU, say N. If you have a system with more 382 than one CPU, say Y. 383 384 If you say N here, the kernel will run on uni- and multiprocessor 385 machines, but will use only one CPU of a multiprocessor machine. If 386 you say Y here, the kernel will run on many, but not all, 387 uniprocessor machines. On a uniprocessor machine, the kernel 388 will run faster if you say N here. 389 390 Note that if you say Y here and choose architecture "586" or 391 "Pentium" under "Processor family", the kernel will not work on 486 392 architectures. Similarly, multiprocessor kernels for the "PPro" 393 architecture may not work on all Pentium based boards. 394 395 People using multiprocessor machines who say Y here should also say 396 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 397 Management" code will be disabled if you say Y here. 398 399 See also <file:Documentation/x86/i386/IO-APIC.txt>, 400 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 401 <http://www.tldp.org/docs.html#howto>. 402 403 If you don't know what to do here, say N. 404 405config X86_FEATURE_NAMES 406 bool "Processor feature human-readable names" if EMBEDDED 407 default y 408 ---help--- 409 This option compiles in a table of x86 feature bits and corresponding 410 names. This is required to support /proc/cpuinfo and a few kernel 411 messages. You can disable this to save space, at the expense of 412 making those few kernel messages show numeric feature bits instead. 413 414 If in doubt, say Y. 415 416config X86_X2APIC 417 bool "Support x2apic" 418 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 419 ---help--- 420 This enables x2apic support on CPUs that have this feature. 421 422 This allows 32-bit apic IDs (so it can support very large systems), 423 and accesses the local apic via MSRs not via mmio. 424 425 If you don't know what to do here, say N. 426 427config X86_MPPARSE 428 bool "Enable MPS table" if ACPI || SFI 429 default y 430 depends on X86_LOCAL_APIC 431 ---help--- 432 For old smp systems that do not have proper acpi support. Newer systems 433 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 434 435config GOLDFISH 436 def_bool y 437 depends on X86_GOLDFISH 438 439config RETPOLINE 440 bool "Avoid speculative indirect branches in kernel" 441 default y 442 select STACK_VALIDATION if HAVE_STACK_VALIDATION 443 help 444 Compile kernel with the retpoline compiler options to guard against 445 kernel-to-user data leaks by avoiding speculative indirect 446 branches. Requires a compiler with -mindirect-branch=thunk-extern 447 support for full protection. The kernel may run slower. 448 449config X86_CPU_RESCTRL 450 bool "x86 CPU resource control support" 451 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 452 select KERNFS 453 help 454 Enable x86 CPU resource control support. 455 456 Provide support for the allocation and monitoring of system resources 457 usage by the CPU. 458 459 Intel calls this Intel Resource Director Technology 460 (Intel(R) RDT). More information about RDT can be found in the 461 Intel x86 Architecture Software Developer Manual. 462 463 AMD calls this AMD Platform Quality of Service (AMD QoS). 464 More information about AMD QoS can be found in the AMD64 Technology 465 Platform Quality of Service Extensions manual. 466 467 Say N if unsure. 468 469if X86_32 470config X86_BIGSMP 471 bool "Support for big SMP systems with more than 8 CPUs" 472 depends on SMP 473 ---help--- 474 This option is needed for the systems that have more than 8 CPUs 475 476config X86_EXTENDED_PLATFORM 477 bool "Support for extended (non-PC) x86 platforms" 478 default y 479 ---help--- 480 If you disable this option then the kernel will only support 481 standard PC platforms. (which covers the vast majority of 482 systems out there.) 483 484 If you enable this option then you'll be able to select support 485 for the following (non-PC) 32 bit x86 platforms: 486 Goldfish (Android emulator) 487 AMD Elan 488 RDC R-321x SoC 489 SGI 320/540 (Visual Workstation) 490 STA2X11-based (e.g. Northville) 491 Moorestown MID devices 492 493 If you have one of these systems, or if you want to build a 494 generic distribution kernel, say Y here - otherwise say N. 495endif 496 497if X86_64 498config X86_EXTENDED_PLATFORM 499 bool "Support for extended (non-PC) x86 platforms" 500 default y 501 ---help--- 502 If you disable this option then the kernel will only support 503 standard PC platforms. (which covers the vast majority of 504 systems out there.) 505 506 If you enable this option then you'll be able to select support 507 for the following (non-PC) 64 bit x86 platforms: 508 Numascale NumaChip 509 ScaleMP vSMP 510 SGI Ultraviolet 511 512 If you have one of these systems, or if you want to build a 513 generic distribution kernel, say Y here - otherwise say N. 514endif 515# This is an alphabetically sorted list of 64 bit extended platforms 516# Please maintain the alphabetic order if and when there are additions 517config X86_NUMACHIP 518 bool "Numascale NumaChip" 519 depends on X86_64 520 depends on X86_EXTENDED_PLATFORM 521 depends on NUMA 522 depends on SMP 523 depends on X86_X2APIC 524 depends on PCI_MMCONFIG 525 ---help--- 526 Adds support for Numascale NumaChip large-SMP systems. Needed to 527 enable more than ~168 cores. 528 If you don't have one of these, you should say N here. 529 530config X86_VSMP 531 bool "ScaleMP vSMP" 532 select HYPERVISOR_GUEST 533 select PARAVIRT 534 depends on X86_64 && PCI 535 depends on X86_EXTENDED_PLATFORM 536 depends on SMP 537 ---help--- 538 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 539 supposed to run on these EM64T-based machines. Only choose this option 540 if you have one of these machines. 541 542config X86_UV 543 bool "SGI Ultraviolet" 544 depends on X86_64 545 depends on X86_EXTENDED_PLATFORM 546 depends on NUMA 547 depends on EFI 548 depends on X86_X2APIC 549 depends on PCI 550 ---help--- 551 This option is needed in order to support SGI Ultraviolet systems. 552 If you don't have one of these, you should say N here. 553 554# Following is an alphabetically sorted list of 32 bit extended platforms 555# Please maintain the alphabetic order if and when there are additions 556 557config X86_GOLDFISH 558 bool "Goldfish (Virtual Platform)" 559 depends on X86_EXTENDED_PLATFORM 560 ---help--- 561 Enable support for the Goldfish virtual platform used primarily 562 for Android development. Unless you are building for the Android 563 Goldfish emulator say N here. 564 565config X86_INTEL_CE 566 bool "CE4100 TV platform" 567 depends on PCI 568 depends on PCI_GODIRECT 569 depends on X86_IO_APIC 570 depends on X86_32 571 depends on X86_EXTENDED_PLATFORM 572 select X86_REBOOTFIXUPS 573 select OF 574 select OF_EARLY_FLATTREE 575 ---help--- 576 Select for the Intel CE media processor (CE4100) SOC. 577 This option compiles in support for the CE4100 SOC for settop 578 boxes and media devices. 579 580config X86_INTEL_MID 581 bool "Intel MID platform support" 582 depends on X86_EXTENDED_PLATFORM 583 depends on X86_PLATFORM_DEVICES 584 depends on PCI 585 depends on X86_64 || (PCI_GOANY && X86_32) 586 depends on X86_IO_APIC 587 select SFI 588 select I2C 589 select DW_APB_TIMER 590 select APB_TIMER 591 select INTEL_SCU_IPC 592 select MFD_INTEL_MSIC 593 ---help--- 594 Select to build a kernel capable of supporting Intel MID (Mobile 595 Internet Device) platform systems which do not have the PCI legacy 596 interfaces. If you are building for a PC class system say N here. 597 598 Intel MID platforms are based on an Intel processor and chipset which 599 consume less power than most of the x86 derivatives. 600 601config X86_INTEL_QUARK 602 bool "Intel Quark platform support" 603 depends on X86_32 604 depends on X86_EXTENDED_PLATFORM 605 depends on X86_PLATFORM_DEVICES 606 depends on X86_TSC 607 depends on PCI 608 depends on PCI_GOANY 609 depends on X86_IO_APIC 610 select IOSF_MBI 611 select INTEL_IMR 612 select COMMON_CLK 613 ---help--- 614 Select to include support for Quark X1000 SoC. 615 Say Y here if you have a Quark based system such as the Arduino 616 compatible Intel Galileo. 617 618config X86_INTEL_LPSS 619 bool "Intel Low Power Subsystem Support" 620 depends on X86 && ACPI && PCI 621 select COMMON_CLK 622 select PINCTRL 623 select IOSF_MBI 624 ---help--- 625 Select to build support for Intel Low Power Subsystem such as 626 found on Intel Lynxpoint PCH. Selecting this option enables 627 things like clock tree (common clock framework) and pincontrol 628 which are needed by the LPSS peripheral drivers. 629 630config X86_AMD_PLATFORM_DEVICE 631 bool "AMD ACPI2Platform devices support" 632 depends on ACPI 633 select COMMON_CLK 634 select PINCTRL 635 ---help--- 636 Select to interpret AMD specific ACPI device to platform device 637 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 638 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 639 implemented under PINCTRL subsystem. 640 641config IOSF_MBI 642 tristate "Intel SoC IOSF Sideband support for SoC platforms" 643 depends on PCI 644 ---help--- 645 This option enables sideband register access support for Intel SoC 646 platforms. On these platforms the IOSF sideband is used in lieu of 647 MSR's for some register accesses, mostly but not limited to thermal 648 and power. Drivers may query the availability of this device to 649 determine if they need the sideband in order to work on these 650 platforms. The sideband is available on the following SoC products. 651 This list is not meant to be exclusive. 652 - BayTrail 653 - Braswell 654 - Quark 655 656 You should say Y if you are running a kernel on one of these SoC's. 657 658config IOSF_MBI_DEBUG 659 bool "Enable IOSF sideband access through debugfs" 660 depends on IOSF_MBI && DEBUG_FS 661 ---help--- 662 Select this option to expose the IOSF sideband access registers (MCR, 663 MDR, MCRX) through debugfs to write and read register information from 664 different units on the SoC. This is most useful for obtaining device 665 state information for debug and analysis. As this is a general access 666 mechanism, users of this option would have specific knowledge of the 667 device they want to access. 668 669 If you don't require the option or are in doubt, say N. 670 671config X86_RDC321X 672 bool "RDC R-321x SoC" 673 depends on X86_32 674 depends on X86_EXTENDED_PLATFORM 675 select M486 676 select X86_REBOOTFIXUPS 677 ---help--- 678 This option is needed for RDC R-321x system-on-chip, also known 679 as R-8610-(G). 680 If you don't have one of these chips, you should say N here. 681 682config X86_32_NON_STANDARD 683 bool "Support non-standard 32-bit SMP architectures" 684 depends on X86_32 && SMP 685 depends on X86_EXTENDED_PLATFORM 686 ---help--- 687 This option compiles in the bigsmp and STA2X11 default 688 subarchitectures. It is intended for a generic binary 689 kernel. If you select them all, kernel will probe it one by 690 one and will fallback to default. 691 692# Alphabetically sorted list of Non standard 32 bit platforms 693 694config X86_SUPPORTS_MEMORY_FAILURE 695 def_bool y 696 # MCE code calls memory_failure(): 697 depends on X86_MCE 698 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 699 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 700 depends on X86_64 || !SPARSEMEM 701 select ARCH_SUPPORTS_MEMORY_FAILURE 702 703config STA2X11 704 bool "STA2X11 Companion Chip Support" 705 depends on X86_32_NON_STANDARD && PCI 706 select ARCH_HAS_PHYS_TO_DMA 707 select X86_DEV_DMA_OPS 708 select X86_DMA_REMAP 709 select SWIOTLB 710 select MFD_STA2X11 711 select GPIOLIB 712 ---help--- 713 This adds support for boards based on the STA2X11 IO-Hub, 714 a.k.a. "ConneXt". The chip is used in place of the standard 715 PC chipset, so all "standard" peripherals are missing. If this 716 option is selected the kernel will still be able to boot on 717 standard PC machines. 718 719config X86_32_IRIS 720 tristate "Eurobraille/Iris poweroff module" 721 depends on X86_32 722 ---help--- 723 The Iris machines from EuroBraille do not have APM or ACPI support 724 to shut themselves down properly. A special I/O sequence is 725 needed to do so, which is what this module does at 726 kernel shutdown. 727 728 This is only for Iris machines from EuroBraille. 729 730 If unused, say N. 731 732config SCHED_OMIT_FRAME_POINTER 733 def_bool y 734 prompt "Single-depth WCHAN output" 735 depends on X86 736 ---help--- 737 Calculate simpler /proc/<PID>/wchan values. If this option 738 is disabled then wchan values will recurse back to the 739 caller function. This provides more accurate wchan values, 740 at the expense of slightly more scheduling overhead. 741 742 If in doubt, say "Y". 743 744menuconfig HYPERVISOR_GUEST 745 bool "Linux guest support" 746 ---help--- 747 Say Y here to enable options for running Linux under various hyper- 748 visors. This option enables basic hypervisor detection and platform 749 setup. 750 751 If you say N, all options in this submenu will be skipped and 752 disabled, and Linux guest support won't be built in. 753 754if HYPERVISOR_GUEST 755 756config PARAVIRT 757 bool "Enable paravirtualization code" 758 ---help--- 759 This changes the kernel so it can modify itself when it is run 760 under a hypervisor, potentially improving performance significantly 761 over full virtualization. However, when run without a hypervisor 762 the kernel is theoretically slower and slightly larger. 763 764config PARAVIRT_XXL 765 bool 766 767config PARAVIRT_DEBUG 768 bool "paravirt-ops debugging" 769 depends on PARAVIRT && DEBUG_KERNEL 770 ---help--- 771 Enable to debug paravirt_ops internals. Specifically, BUG if 772 a paravirt_op is missing when it is called. 773 774config PARAVIRT_SPINLOCKS 775 bool "Paravirtualization layer for spinlocks" 776 depends on PARAVIRT && SMP 777 ---help--- 778 Paravirtualized spinlocks allow a pvops backend to replace the 779 spinlock implementation with something virtualization-friendly 780 (for example, block the virtual CPU rather than spinning). 781 782 It has a minimal impact on native kernels and gives a nice performance 783 benefit on paravirtualized KVM / Xen kernels. 784 785 If you are unsure how to answer this question, answer Y. 786 787config QUEUED_LOCK_STAT 788 bool "Paravirt queued spinlock statistics" 789 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 790 ---help--- 791 Enable the collection of statistical data on the slowpath 792 behavior of paravirtualized queued spinlocks and report 793 them on debugfs. 794 795source "arch/x86/xen/Kconfig" 796 797config KVM_GUEST 798 bool "KVM Guest support (including kvmclock)" 799 depends on PARAVIRT 800 select PARAVIRT_CLOCK 801 default y 802 ---help--- 803 This option enables various optimizations for running under the KVM 804 hypervisor. It includes a paravirtualized clock, so that instead 805 of relying on a PIT (or probably other) emulation by the 806 underlying device model, the host provides the guest with 807 timing infrastructure such as time of day, and system time 808 809config PVH 810 bool "Support for running PVH guests" 811 ---help--- 812 This option enables the PVH entry point for guest virtual machines 813 as specified in the x86/HVM direct boot ABI. 814 815config KVM_DEBUG_FS 816 bool "Enable debug information for KVM Guests in debugfs" 817 depends on KVM_GUEST && DEBUG_FS 818 ---help--- 819 This option enables collection of various statistics for KVM guest. 820 Statistics are displayed in debugfs filesystem. Enabling this option 821 may incur significant overhead. 822 823config PARAVIRT_TIME_ACCOUNTING 824 bool "Paravirtual steal time accounting" 825 depends on PARAVIRT 826 ---help--- 827 Select this option to enable fine granularity task steal time 828 accounting. Time spent executing other tasks in parallel with 829 the current vCPU is discounted from the vCPU power. To account for 830 that, there can be a small performance impact. 831 832 If in doubt, say N here. 833 834config PARAVIRT_CLOCK 835 bool 836 837config JAILHOUSE_GUEST 838 bool "Jailhouse non-root cell support" 839 depends on X86_64 && PCI 840 select X86_PM_TIMER 841 ---help--- 842 This option allows to run Linux as guest in a Jailhouse non-root 843 cell. You can leave this option disabled if you only want to start 844 Jailhouse and run Linux afterwards in the root cell. 845 846endif #HYPERVISOR_GUEST 847 848source "arch/x86/Kconfig.cpu" 849 850config HPET_TIMER 851 def_bool X86_64 852 prompt "HPET Timer Support" if X86_32 853 ---help--- 854 Use the IA-PC HPET (High Precision Event Timer) to manage 855 time in preference to the PIT and RTC, if a HPET is 856 present. 857 HPET is the next generation timer replacing legacy 8254s. 858 The HPET provides a stable time base on SMP 859 systems, unlike the TSC, but it is more expensive to access, 860 as it is off-chip. The interface used is documented 861 in the HPET spec, revision 1. 862 863 You can safely choose Y here. However, HPET will only be 864 activated if the platform and the BIOS support this feature. 865 Otherwise the 8254 will be used for timing services. 866 867 Choose N to continue using the legacy 8254 timer. 868 869config HPET_EMULATE_RTC 870 def_bool y 871 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 872 873config APB_TIMER 874 def_bool y if X86_INTEL_MID 875 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 876 select DW_APB_TIMER 877 depends on X86_INTEL_MID && SFI 878 help 879 APB timer is the replacement for 8254, HPET on X86 MID platforms. 880 The APBT provides a stable time base on SMP 881 systems, unlike the TSC, but it is more expensive to access, 882 as it is off-chip. APB timers are always running regardless of CPU 883 C states, they are used as per CPU clockevent device when possible. 884 885# Mark as expert because too many people got it wrong. 886# The code disables itself when not needed. 887config DMI 888 default y 889 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 890 bool "Enable DMI scanning" if EXPERT 891 ---help--- 892 Enabled scanning of DMI to identify machine quirks. Say Y 893 here unless you have verified that your setup is not 894 affected by entries in the DMI blacklist. Required by PNP 895 BIOS code. 896 897config GART_IOMMU 898 bool "Old AMD GART IOMMU support" 899 select IOMMU_HELPER 900 select SWIOTLB 901 depends on X86_64 && PCI && AMD_NB 902 ---help--- 903 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 904 GART based hardware IOMMUs. 905 906 The GART supports full DMA access for devices with 32-bit access 907 limitations, on systems with more than 3 GB. This is usually needed 908 for USB, sound, many IDE/SATA chipsets and some other devices. 909 910 Newer systems typically have a modern AMD IOMMU, supported via 911 the CONFIG_AMD_IOMMU=y config option. 912 913 In normal configurations this driver is only active when needed: 914 there's more than 3 GB of memory and the system contains a 915 32-bit limited device. 916 917 If unsure, say Y. 918 919config CALGARY_IOMMU 920 bool "IBM Calgary IOMMU support" 921 select IOMMU_HELPER 922 select SWIOTLB 923 depends on X86_64 && PCI 924 ---help--- 925 Support for hardware IOMMUs in IBM's xSeries x366 and x460 926 systems. Needed to run systems with more than 3GB of memory 927 properly with 32-bit PCI devices that do not support DAC 928 (Double Address Cycle). Calgary also supports bus level 929 isolation, where all DMAs pass through the IOMMU. This 930 prevents them from going anywhere except their intended 931 destination. This catches hard-to-find kernel bugs and 932 mis-behaving drivers and devices that do not use the DMA-API 933 properly to set up their DMA buffers. The IOMMU can be 934 turned off at boot time with the iommu=off parameter. 935 Normally the kernel will make the right choice by itself. 936 If unsure, say Y. 937 938config CALGARY_IOMMU_ENABLED_BY_DEFAULT 939 def_bool y 940 prompt "Should Calgary be enabled by default?" 941 depends on CALGARY_IOMMU 942 ---help--- 943 Should Calgary be enabled by default? if you choose 'y', Calgary 944 will be used (if it exists). If you choose 'n', Calgary will not be 945 used even if it exists. If you choose 'n' and would like to use 946 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 947 If unsure, say Y. 948 949config MAXSMP 950 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 951 depends on X86_64 && SMP && DEBUG_KERNEL 952 select CPUMASK_OFFSTACK 953 ---help--- 954 Enable maximum number of CPUS and NUMA Nodes for this architecture. 955 If unsure, say N. 956 957# 958# The maximum number of CPUs supported: 959# 960# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 961# and which can be configured interactively in the 962# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 963# 964# The ranges are different on 32-bit and 64-bit kernels, depending on 965# hardware capabilities and scalability features of the kernel. 966# 967# ( If MAXSMP is enabled we just use the highest possible value and disable 968# interactive configuration. ) 969# 970 971config NR_CPUS_RANGE_BEGIN 972 int 973 default NR_CPUS_RANGE_END if MAXSMP 974 default 1 if !SMP 975 default 2 976 977config NR_CPUS_RANGE_END 978 int 979 depends on X86_32 980 default 64 if SMP && X86_BIGSMP 981 default 8 if SMP && !X86_BIGSMP 982 default 1 if !SMP 983 984config NR_CPUS_RANGE_END 985 int 986 depends on X86_64 987 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 988 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 989 default 1 if !SMP 990 991config NR_CPUS_DEFAULT 992 int 993 depends on X86_32 994 default 32 if X86_BIGSMP 995 default 8 if SMP 996 default 1 if !SMP 997 998config NR_CPUS_DEFAULT 999 int 1000 depends on X86_64 1001 default 8192 if MAXSMP 1002 default 64 if SMP 1003 default 1 if !SMP 1004 1005config NR_CPUS 1006 int "Maximum number of CPUs" if SMP && !MAXSMP 1007 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1008 default NR_CPUS_DEFAULT 1009 ---help--- 1010 This allows you to specify the maximum number of CPUs which this 1011 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1012 supported value is 8192, otherwise the maximum value is 512. The 1013 minimum value which makes sense is 2. 1014 1015 This is purely to save memory: each supported CPU adds about 8KB 1016 to the kernel image. 1017 1018config SCHED_SMT 1019 def_bool y if SMP 1020 1021config SCHED_MC 1022 def_bool y 1023 prompt "Multi-core scheduler support" 1024 depends on SMP 1025 ---help--- 1026 Multi-core scheduler support improves the CPU scheduler's decision 1027 making when dealing with multi-core CPU chips at a cost of slightly 1028 increased overhead in some places. If unsure say N here. 1029 1030config SCHED_MC_PRIO 1031 bool "CPU core priorities scheduler support" 1032 depends on SCHED_MC && CPU_SUP_INTEL 1033 select X86_INTEL_PSTATE 1034 select CPU_FREQ 1035 default y 1036 ---help--- 1037 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1038 core ordering determined at manufacturing time, which allows 1039 certain cores to reach higher turbo frequencies (when running 1040 single threaded workloads) than others. 1041 1042 Enabling this kernel feature teaches the scheduler about 1043 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1044 scheduler's CPU selection logic accordingly, so that higher 1045 overall system performance can be achieved. 1046 1047 This feature will have no effect on CPUs without this feature. 1048 1049 If unsure say Y here. 1050 1051config UP_LATE_INIT 1052 def_bool y 1053 depends on !SMP && X86_LOCAL_APIC 1054 1055config X86_UP_APIC 1056 bool "Local APIC support on uniprocessors" if !PCI_MSI 1057 default PCI_MSI 1058 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1059 ---help--- 1060 A local APIC (Advanced Programmable Interrupt Controller) is an 1061 integrated interrupt controller in the CPU. If you have a single-CPU 1062 system which has a processor with a local APIC, you can say Y here to 1063 enable and use it. If you say Y here even though your machine doesn't 1064 have a local APIC, then the kernel will still run with no slowdown at 1065 all. The local APIC supports CPU-generated self-interrupts (timer, 1066 performance counters), and the NMI watchdog which detects hard 1067 lockups. 1068 1069config X86_UP_IOAPIC 1070 bool "IO-APIC support on uniprocessors" 1071 depends on X86_UP_APIC 1072 ---help--- 1073 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1074 SMP-capable replacement for PC-style interrupt controllers. Most 1075 SMP systems and many recent uniprocessor systems have one. 1076 1077 If you have a single-CPU system with an IO-APIC, you can say Y here 1078 to use it. If you say Y here even though your machine doesn't have 1079 an IO-APIC, then the kernel will still run with no slowdown at all. 1080 1081config X86_LOCAL_APIC 1082 def_bool y 1083 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1084 select IRQ_DOMAIN_HIERARCHY 1085 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1086 1087config X86_IO_APIC 1088 def_bool y 1089 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1090 1091config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1092 bool "Reroute for broken boot IRQs" 1093 depends on X86_IO_APIC 1094 ---help--- 1095 This option enables a workaround that fixes a source of 1096 spurious interrupts. This is recommended when threaded 1097 interrupt handling is used on systems where the generation of 1098 superfluous "boot interrupts" cannot be disabled. 1099 1100 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1101 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1102 kernel does during interrupt handling). On chipsets where this 1103 boot IRQ generation cannot be disabled, this workaround keeps 1104 the original IRQ line masked so that only the equivalent "boot 1105 IRQ" is delivered to the CPUs. The workaround also tells the 1106 kernel to set up the IRQ handler on the boot IRQ line. In this 1107 way only one interrupt is delivered to the kernel. Otherwise 1108 the spurious second interrupt may cause the kernel to bring 1109 down (vital) interrupt lines. 1110 1111 Only affects "broken" chipsets. Interrupt sharing may be 1112 increased on these systems. 1113 1114config X86_MCE 1115 bool "Machine Check / overheating reporting" 1116 select GENERIC_ALLOCATOR 1117 default y 1118 ---help--- 1119 Machine Check support allows the processor to notify the 1120 kernel if it detects a problem (e.g. overheating, data corruption). 1121 The action the kernel takes depends on the severity of the problem, 1122 ranging from warning messages to halting the machine. 1123 1124config X86_MCELOG_LEGACY 1125 bool "Support for deprecated /dev/mcelog character device" 1126 depends on X86_MCE 1127 ---help--- 1128 Enable support for /dev/mcelog which is needed by the old mcelog 1129 userspace logging daemon. Consider switching to the new generation 1130 rasdaemon solution. 1131 1132config X86_MCE_INTEL 1133 def_bool y 1134 prompt "Intel MCE features" 1135 depends on X86_MCE && X86_LOCAL_APIC 1136 ---help--- 1137 Additional support for intel specific MCE features such as 1138 the thermal monitor. 1139 1140config X86_MCE_AMD 1141 def_bool y 1142 prompt "AMD MCE features" 1143 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1144 ---help--- 1145 Additional support for AMD specific MCE features such as 1146 the DRAM Error Threshold. 1147 1148config X86_ANCIENT_MCE 1149 bool "Support for old Pentium 5 / WinChip machine checks" 1150 depends on X86_32 && X86_MCE 1151 ---help--- 1152 Include support for machine check handling on old Pentium 5 or WinChip 1153 systems. These typically need to be enabled explicitly on the command 1154 line. 1155 1156config X86_MCE_THRESHOLD 1157 depends on X86_MCE_AMD || X86_MCE_INTEL 1158 def_bool y 1159 1160config X86_MCE_INJECT 1161 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1162 tristate "Machine check injector support" 1163 ---help--- 1164 Provide support for injecting machine checks for testing purposes. 1165 If you don't know what a machine check is and you don't do kernel 1166 QA it is safe to say n. 1167 1168config X86_THERMAL_VECTOR 1169 def_bool y 1170 depends on X86_MCE_INTEL 1171 1172source "arch/x86/events/Kconfig" 1173 1174config X86_LEGACY_VM86 1175 bool "Legacy VM86 support" 1176 depends on X86_32 1177 ---help--- 1178 This option allows user programs to put the CPU into V8086 1179 mode, which is an 80286-era approximation of 16-bit real mode. 1180 1181 Some very old versions of X and/or vbetool require this option 1182 for user mode setting. Similarly, DOSEMU will use it if 1183 available to accelerate real mode DOS programs. However, any 1184 recent version of DOSEMU, X, or vbetool should be fully 1185 functional even without kernel VM86 support, as they will all 1186 fall back to software emulation. Nevertheless, if you are using 1187 a 16-bit DOS program where 16-bit performance matters, vm86 1188 mode might be faster than emulation and you might want to 1189 enable this option. 1190 1191 Note that any app that works on a 64-bit kernel is unlikely to 1192 need this option, as 64-bit kernels don't, and can't, support 1193 V8086 mode. This option is also unrelated to 16-bit protected 1194 mode and is not needed to run most 16-bit programs under Wine. 1195 1196 Enabling this option increases the complexity of the kernel 1197 and slows down exception handling a tiny bit. 1198 1199 If unsure, say N here. 1200 1201config VM86 1202 bool 1203 default X86_LEGACY_VM86 1204 1205config X86_16BIT 1206 bool "Enable support for 16-bit segments" if EXPERT 1207 default y 1208 depends on MODIFY_LDT_SYSCALL 1209 ---help--- 1210 This option is required by programs like Wine to run 16-bit 1211 protected mode legacy code on x86 processors. Disabling 1212 this option saves about 300 bytes on i386, or around 6K text 1213 plus 16K runtime memory on x86-64, 1214 1215config X86_ESPFIX32 1216 def_bool y 1217 depends on X86_16BIT && X86_32 1218 1219config X86_ESPFIX64 1220 def_bool y 1221 depends on X86_16BIT && X86_64 1222 1223config X86_VSYSCALL_EMULATION 1224 bool "Enable vsyscall emulation" if EXPERT 1225 default y 1226 depends on X86_64 1227 ---help--- 1228 This enables emulation of the legacy vsyscall page. Disabling 1229 it is roughly equivalent to booting with vsyscall=none, except 1230 that it will also disable the helpful warning if a program 1231 tries to use a vsyscall. With this option set to N, offending 1232 programs will just segfault, citing addresses of the form 1233 0xffffffffff600?00. 1234 1235 This option is required by many programs built before 2013, and 1236 care should be used even with newer programs if set to N. 1237 1238 Disabling this option saves about 7K of kernel size and 1239 possibly 4K of additional runtime pagetable memory. 1240 1241config TOSHIBA 1242 tristate "Toshiba Laptop support" 1243 depends on X86_32 1244 ---help--- 1245 This adds a driver to safely access the System Management Mode of 1246 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1247 not work on models with a Phoenix BIOS. The System Management Mode 1248 is used to set the BIOS and power saving options on Toshiba portables. 1249 1250 For information on utilities to make use of this driver see the 1251 Toshiba Linux utilities web site at: 1252 <http://www.buzzard.org.uk/toshiba/>. 1253 1254 Say Y if you intend to run this kernel on a Toshiba portable. 1255 Say N otherwise. 1256 1257config I8K 1258 tristate "Dell i8k legacy laptop support" 1259 select HWMON 1260 select SENSORS_DELL_SMM 1261 ---help--- 1262 This option enables legacy /proc/i8k userspace interface in hwmon 1263 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1264 temperature and allows controlling fan speeds of Dell laptops via 1265 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1266 it reports also power and hotkey status. For fan speed control is 1267 needed userspace package i8kutils. 1268 1269 Say Y if you intend to run this kernel on old Dell laptops or want to 1270 use userspace package i8kutils. 1271 Say N otherwise. 1272 1273config X86_REBOOTFIXUPS 1274 bool "Enable X86 board specific fixups for reboot" 1275 depends on X86_32 1276 ---help--- 1277 This enables chipset and/or board specific fixups to be done 1278 in order to get reboot to work correctly. This is only needed on 1279 some combinations of hardware and BIOS. The symptom, for which 1280 this config is intended, is when reboot ends with a stalled/hung 1281 system. 1282 1283 Currently, the only fixup is for the Geode machines using 1284 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1285 1286 Say Y if you want to enable the fixup. Currently, it's safe to 1287 enable this option even if you don't need it. 1288 Say N otherwise. 1289 1290config MICROCODE 1291 bool "CPU microcode loading support" 1292 default y 1293 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1294 select FW_LOADER 1295 ---help--- 1296 If you say Y here, you will be able to update the microcode on 1297 Intel and AMD processors. The Intel support is for the IA32 family, 1298 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1299 AMD support is for families 0x10 and later. You will obviously need 1300 the actual microcode binary data itself which is not shipped with 1301 the Linux kernel. 1302 1303 The preferred method to load microcode from a detached initrd is described 1304 in Documentation/x86/microcode.txt. For that you need to enable 1305 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1306 initrd for microcode blobs. 1307 1308 In addition, you can build the microcode into the kernel. For that you 1309 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1310 config option. 1311 1312config MICROCODE_INTEL 1313 bool "Intel microcode loading support" 1314 depends on MICROCODE 1315 default MICROCODE 1316 select FW_LOADER 1317 ---help--- 1318 This options enables microcode patch loading support for Intel 1319 processors. 1320 1321 For the current Intel microcode data package go to 1322 <https://downloadcenter.intel.com> and search for 1323 'Linux Processor Microcode Data File'. 1324 1325config MICROCODE_AMD 1326 bool "AMD microcode loading support" 1327 depends on MICROCODE 1328 select FW_LOADER 1329 ---help--- 1330 If you select this option, microcode patch loading support for AMD 1331 processors will be enabled. 1332 1333config MICROCODE_OLD_INTERFACE 1334 def_bool y 1335 depends on MICROCODE 1336 1337config X86_MSR 1338 tristate "/dev/cpu/*/msr - Model-specific register support" 1339 ---help--- 1340 This device gives privileged processes access to the x86 1341 Model-Specific Registers (MSRs). It is a character device with 1342 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1343 MSR accesses are directed to a specific CPU on multi-processor 1344 systems. 1345 1346config X86_CPUID 1347 tristate "/dev/cpu/*/cpuid - CPU information support" 1348 ---help--- 1349 This device gives processes access to the x86 CPUID instruction to 1350 be executed on a specific processor. It is a character device 1351 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1352 /dev/cpu/31/cpuid. 1353 1354choice 1355 prompt "High Memory Support" 1356 default HIGHMEM4G 1357 depends on X86_32 1358 1359config NOHIGHMEM 1360 bool "off" 1361 ---help--- 1362 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1363 However, the address space of 32-bit x86 processors is only 4 1364 Gigabytes large. That means that, if you have a large amount of 1365 physical memory, not all of it can be "permanently mapped" by the 1366 kernel. The physical memory that's not permanently mapped is called 1367 "high memory". 1368 1369 If you are compiling a kernel which will never run on a machine with 1370 more than 1 Gigabyte total physical RAM, answer "off" here (default 1371 choice and suitable for most users). This will result in a "3GB/1GB" 1372 split: 3GB are mapped so that each process sees a 3GB virtual memory 1373 space and the remaining part of the 4GB virtual memory space is used 1374 by the kernel to permanently map as much physical memory as 1375 possible. 1376 1377 If the machine has between 1 and 4 Gigabytes physical RAM, then 1378 answer "4GB" here. 1379 1380 If more than 4 Gigabytes is used then answer "64GB" here. This 1381 selection turns Intel PAE (Physical Address Extension) mode on. 1382 PAE implements 3-level paging on IA32 processors. PAE is fully 1383 supported by Linux, PAE mode is implemented on all recent Intel 1384 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1385 then the kernel will not boot on CPUs that don't support PAE! 1386 1387 The actual amount of total physical memory will either be 1388 auto detected or can be forced by using a kernel command line option 1389 such as "mem=256M". (Try "man bootparam" or see the documentation of 1390 your boot loader (lilo or loadlin) about how to pass options to the 1391 kernel at boot time.) 1392 1393 If unsure, say "off". 1394 1395config HIGHMEM4G 1396 bool "4GB" 1397 ---help--- 1398 Select this if you have a 32-bit processor and between 1 and 4 1399 gigabytes of physical RAM. 1400 1401config HIGHMEM64G 1402 bool "64GB" 1403 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1404 select X86_PAE 1405 ---help--- 1406 Select this if you have a 32-bit processor and more than 4 1407 gigabytes of physical RAM. 1408 1409endchoice 1410 1411choice 1412 prompt "Memory split" if EXPERT 1413 default VMSPLIT_3G 1414 depends on X86_32 1415 ---help--- 1416 Select the desired split between kernel and user memory. 1417 1418 If the address range available to the kernel is less than the 1419 physical memory installed, the remaining memory will be available 1420 as "high memory". Accessing high memory is a little more costly 1421 than low memory, as it needs to be mapped into the kernel first. 1422 Note that increasing the kernel address space limits the range 1423 available to user programs, making the address space there 1424 tighter. Selecting anything other than the default 3G/1G split 1425 will also likely make your kernel incompatible with binary-only 1426 kernel modules. 1427 1428 If you are not absolutely sure what you are doing, leave this 1429 option alone! 1430 1431 config VMSPLIT_3G 1432 bool "3G/1G user/kernel split" 1433 config VMSPLIT_3G_OPT 1434 depends on !X86_PAE 1435 bool "3G/1G user/kernel split (for full 1G low memory)" 1436 config VMSPLIT_2G 1437 bool "2G/2G user/kernel split" 1438 config VMSPLIT_2G_OPT 1439 depends on !X86_PAE 1440 bool "2G/2G user/kernel split (for full 2G low memory)" 1441 config VMSPLIT_1G 1442 bool "1G/3G user/kernel split" 1443endchoice 1444 1445config PAGE_OFFSET 1446 hex 1447 default 0xB0000000 if VMSPLIT_3G_OPT 1448 default 0x80000000 if VMSPLIT_2G 1449 default 0x78000000 if VMSPLIT_2G_OPT 1450 default 0x40000000 if VMSPLIT_1G 1451 default 0xC0000000 1452 depends on X86_32 1453 1454config HIGHMEM 1455 def_bool y 1456 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1457 1458config X86_PAE 1459 bool "PAE (Physical Address Extension) Support" 1460 depends on X86_32 && !HIGHMEM4G 1461 select PHYS_ADDR_T_64BIT 1462 select SWIOTLB 1463 ---help--- 1464 PAE is required for NX support, and furthermore enables 1465 larger swapspace support for non-overcommit purposes. It 1466 has the cost of more pagetable lookup overhead, and also 1467 consumes more pagetable space per process. 1468 1469config X86_5LEVEL 1470 bool "Enable 5-level page tables support" 1471 select DYNAMIC_MEMORY_LAYOUT 1472 select SPARSEMEM_VMEMMAP 1473 depends on X86_64 1474 ---help--- 1475 5-level paging enables access to larger address space: 1476 upto 128 PiB of virtual address space and 4 PiB of 1477 physical address space. 1478 1479 It will be supported by future Intel CPUs. 1480 1481 A kernel with the option enabled can be booted on machines that 1482 support 4- or 5-level paging. 1483 1484 See Documentation/x86/x86_64/5level-paging.txt for more 1485 information. 1486 1487 Say N if unsure. 1488 1489config X86_DIRECT_GBPAGES 1490 def_bool y 1491 depends on X86_64 && !DEBUG_PAGEALLOC 1492 ---help--- 1493 Certain kernel features effectively disable kernel 1494 linear 1 GB mappings (even if the CPU otherwise 1495 supports them), so don't confuse the user by printing 1496 that we have them enabled. 1497 1498config X86_CPA_STATISTICS 1499 bool "Enable statistic for Change Page Attribute" 1500 depends on DEBUG_FS 1501 ---help--- 1502 Expose statistics about the Change Page Attribute mechanims, which 1503 helps to determine the effectivness of preserving large and huge 1504 page mappings when mapping protections are changed. 1505 1506config ARCH_HAS_MEM_ENCRYPT 1507 def_bool y 1508 1509config AMD_MEM_ENCRYPT 1510 bool "AMD Secure Memory Encryption (SME) support" 1511 depends on X86_64 && CPU_SUP_AMD 1512 select DYNAMIC_PHYSICAL_MASK 1513 select ARCH_USE_MEMREMAP_PROT 1514 ---help--- 1515 Say yes to enable support for the encryption of system memory. 1516 This requires an AMD processor that supports Secure Memory 1517 Encryption (SME). 1518 1519config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1520 bool "Activate AMD Secure Memory Encryption (SME) by default" 1521 default y 1522 depends on AMD_MEM_ENCRYPT 1523 ---help--- 1524 Say yes to have system memory encrypted by default if running on 1525 an AMD processor that supports Secure Memory Encryption (SME). 1526 1527 If set to Y, then the encryption of system memory can be 1528 deactivated with the mem_encrypt=off command line option. 1529 1530 If set to N, then the encryption of system memory can be 1531 activated with the mem_encrypt=on command line option. 1532 1533# Common NUMA Features 1534config NUMA 1535 bool "Numa Memory Allocation and Scheduler Support" 1536 depends on SMP 1537 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1538 default y if X86_BIGSMP 1539 ---help--- 1540 Enable NUMA (Non Uniform Memory Access) support. 1541 1542 The kernel will try to allocate memory used by a CPU on the 1543 local memory controller of the CPU and add some more 1544 NUMA awareness to the kernel. 1545 1546 For 64-bit this is recommended if the system is Intel Core i7 1547 (or later), AMD Opteron, or EM64T NUMA. 1548 1549 For 32-bit this is only needed if you boot a 32-bit 1550 kernel on a 64-bit NUMA platform. 1551 1552 Otherwise, you should say N. 1553 1554config AMD_NUMA 1555 def_bool y 1556 prompt "Old style AMD Opteron NUMA detection" 1557 depends on X86_64 && NUMA && PCI 1558 ---help--- 1559 Enable AMD NUMA node topology detection. You should say Y here if 1560 you have a multi processor AMD system. This uses an old method to 1561 read the NUMA configuration directly from the builtin Northbridge 1562 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1563 which also takes priority if both are compiled in. 1564 1565config X86_64_ACPI_NUMA 1566 def_bool y 1567 prompt "ACPI NUMA detection" 1568 depends on X86_64 && NUMA && ACPI && PCI 1569 select ACPI_NUMA 1570 ---help--- 1571 Enable ACPI SRAT based node topology detection. 1572 1573# Some NUMA nodes have memory ranges that span 1574# other nodes. Even though a pfn is valid and 1575# between a node's start and end pfns, it may not 1576# reside on that node. See memmap_init_zone() 1577# for details. 1578config NODES_SPAN_OTHER_NODES 1579 def_bool y 1580 depends on X86_64_ACPI_NUMA 1581 1582config NUMA_EMU 1583 bool "NUMA emulation" 1584 depends on NUMA 1585 ---help--- 1586 Enable NUMA emulation. A flat machine will be split 1587 into virtual nodes when booted with "numa=fake=N", where N is the 1588 number of nodes. This is only useful for debugging. 1589 1590config NODES_SHIFT 1591 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1592 range 1 10 1593 default "10" if MAXSMP 1594 default "6" if X86_64 1595 default "3" 1596 depends on NEED_MULTIPLE_NODES 1597 ---help--- 1598 Specify the maximum number of NUMA Nodes available on the target 1599 system. Increases memory reserved to accommodate various tables. 1600 1601config ARCH_HAVE_MEMORY_PRESENT 1602 def_bool y 1603 depends on X86_32 && DISCONTIGMEM 1604 1605config ARCH_FLATMEM_ENABLE 1606 def_bool y 1607 depends on X86_32 && !NUMA 1608 1609config ARCH_DISCONTIGMEM_ENABLE 1610 def_bool y 1611 depends on NUMA && X86_32 1612 1613config ARCH_DISCONTIGMEM_DEFAULT 1614 def_bool y 1615 depends on NUMA && X86_32 1616 1617config ARCH_SPARSEMEM_ENABLE 1618 def_bool y 1619 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1620 select SPARSEMEM_STATIC if X86_32 1621 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1622 1623config ARCH_SPARSEMEM_DEFAULT 1624 def_bool y 1625 depends on X86_64 1626 1627config ARCH_SELECT_MEMORY_MODEL 1628 def_bool y 1629 depends on ARCH_SPARSEMEM_ENABLE 1630 1631config ARCH_MEMORY_PROBE 1632 bool "Enable sysfs memory/probe interface" 1633 depends on X86_64 && MEMORY_HOTPLUG 1634 help 1635 This option enables a sysfs memory/probe interface for testing. 1636 See Documentation/memory-hotplug.txt for more information. 1637 If you are unsure how to answer this question, answer N. 1638 1639config ARCH_PROC_KCORE_TEXT 1640 def_bool y 1641 depends on X86_64 && PROC_KCORE 1642 1643config ILLEGAL_POINTER_VALUE 1644 hex 1645 default 0 if X86_32 1646 default 0xdead000000000000 if X86_64 1647 1648config X86_PMEM_LEGACY_DEVICE 1649 bool 1650 1651config X86_PMEM_LEGACY 1652 tristate "Support non-standard NVDIMMs and ADR protected memory" 1653 depends on PHYS_ADDR_T_64BIT 1654 depends on BLK_DEV 1655 select X86_PMEM_LEGACY_DEVICE 1656 select LIBNVDIMM 1657 help 1658 Treat memory marked using the non-standard e820 type of 12 as used 1659 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1660 The kernel will offer these regions to the 'pmem' driver so 1661 they can be used for persistent storage. 1662 1663 Say Y if unsure. 1664 1665config HIGHPTE 1666 bool "Allocate 3rd-level pagetables from highmem" 1667 depends on HIGHMEM 1668 ---help--- 1669 The VM uses one page table entry for each page of physical memory. 1670 For systems with a lot of RAM, this can be wasteful of precious 1671 low memory. Setting this option will put user-space page table 1672 entries in high memory. 1673 1674config X86_CHECK_BIOS_CORRUPTION 1675 bool "Check for low memory corruption" 1676 ---help--- 1677 Periodically check for memory corruption in low memory, which 1678 is suspected to be caused by BIOS. Even when enabled in the 1679 configuration, it is disabled at runtime. Enable it by 1680 setting "memory_corruption_check=1" on the kernel command 1681 line. By default it scans the low 64k of memory every 60 1682 seconds; see the memory_corruption_check_size and 1683 memory_corruption_check_period parameters in 1684 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1685 1686 When enabled with the default parameters, this option has 1687 almost no overhead, as it reserves a relatively small amount 1688 of memory and scans it infrequently. It both detects corruption 1689 and prevents it from affecting the running system. 1690 1691 It is, however, intended as a diagnostic tool; if repeatable 1692 BIOS-originated corruption always affects the same memory, 1693 you can use memmap= to prevent the kernel from using that 1694 memory. 1695 1696config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1697 bool "Set the default setting of memory_corruption_check" 1698 depends on X86_CHECK_BIOS_CORRUPTION 1699 default y 1700 ---help--- 1701 Set whether the default state of memory_corruption_check is 1702 on or off. 1703 1704config X86_RESERVE_LOW 1705 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1706 default 64 1707 range 4 640 1708 ---help--- 1709 Specify the amount of low memory to reserve for the BIOS. 1710 1711 The first page contains BIOS data structures that the kernel 1712 must not use, so that page must always be reserved. 1713 1714 By default we reserve the first 64K of physical RAM, as a 1715 number of BIOSes are known to corrupt that memory range 1716 during events such as suspend/resume or monitor cable 1717 insertion, so it must not be used by the kernel. 1718 1719 You can set this to 4 if you are absolutely sure that you 1720 trust the BIOS to get all its memory reservations and usages 1721 right. If you know your BIOS have problems beyond the 1722 default 64K area, you can set this to 640 to avoid using the 1723 entire low memory range. 1724 1725 If you have doubts about the BIOS (e.g. suspend/resume does 1726 not work or there's kernel crashes after certain hardware 1727 hotplug events) then you might want to enable 1728 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1729 typical corruption patterns. 1730 1731 Leave this to the default value of 64 if you are unsure. 1732 1733config MATH_EMULATION 1734 bool 1735 depends on MODIFY_LDT_SYSCALL 1736 prompt "Math emulation" if X86_32 1737 ---help--- 1738 Linux can emulate a math coprocessor (used for floating point 1739 operations) if you don't have one. 486DX and Pentium processors have 1740 a math coprocessor built in, 486SX and 386 do not, unless you added 1741 a 487DX or 387, respectively. (The messages during boot time can 1742 give you some hints here ["man dmesg"].) Everyone needs either a 1743 coprocessor or this emulation. 1744 1745 If you don't have a math coprocessor, you need to say Y here; if you 1746 say Y here even though you have a coprocessor, the coprocessor will 1747 be used nevertheless. (This behavior can be changed with the kernel 1748 command line option "no387", which comes handy if your coprocessor 1749 is broken. Try "man bootparam" or see the documentation of your boot 1750 loader (lilo or loadlin) about how to pass options to the kernel at 1751 boot time.) This means that it is a good idea to say Y here if you 1752 intend to use this kernel on different machines. 1753 1754 More information about the internals of the Linux math coprocessor 1755 emulation can be found in <file:arch/x86/math-emu/README>. 1756 1757 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1758 kernel, it won't hurt. 1759 1760config MTRR 1761 def_bool y 1762 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1763 ---help--- 1764 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1765 the Memory Type Range Registers (MTRRs) may be used to control 1766 processor access to memory ranges. This is most useful if you have 1767 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1768 allows bus write transfers to be combined into a larger transfer 1769 before bursting over the PCI/AGP bus. This can increase performance 1770 of image write operations 2.5 times or more. Saying Y here creates a 1771 /proc/mtrr file which may be used to manipulate your processor's 1772 MTRRs. Typically the X server should use this. 1773 1774 This code has a reasonably generic interface so that similar 1775 control registers on other processors can be easily supported 1776 as well: 1777 1778 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1779 Registers (ARRs) which provide a similar functionality to MTRRs. For 1780 these, the ARRs are used to emulate the MTRRs. 1781 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1782 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1783 write-combining. All of these processors are supported by this code 1784 and it makes sense to say Y here if you have one of them. 1785 1786 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1787 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1788 can lead to all sorts of problems, so it's good to say Y here. 1789 1790 You can safely say Y even if your machine doesn't have MTRRs, you'll 1791 just add about 9 KB to your kernel. 1792 1793 See <file:Documentation/x86/mtrr.txt> for more information. 1794 1795config MTRR_SANITIZER 1796 def_bool y 1797 prompt "MTRR cleanup support" 1798 depends on MTRR 1799 ---help--- 1800 Convert MTRR layout from continuous to discrete, so X drivers can 1801 add writeback entries. 1802 1803 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1804 The largest mtrr entry size for a continuous block can be set with 1805 mtrr_chunk_size. 1806 1807 If unsure, say Y. 1808 1809config MTRR_SANITIZER_ENABLE_DEFAULT 1810 int "MTRR cleanup enable value (0-1)" 1811 range 0 1 1812 default "0" 1813 depends on MTRR_SANITIZER 1814 ---help--- 1815 Enable mtrr cleanup default value 1816 1817config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1818 int "MTRR cleanup spare reg num (0-7)" 1819 range 0 7 1820 default "1" 1821 depends on MTRR_SANITIZER 1822 ---help--- 1823 mtrr cleanup spare entries default, it can be changed via 1824 mtrr_spare_reg_nr=N on the kernel command line. 1825 1826config X86_PAT 1827 def_bool y 1828 prompt "x86 PAT support" if EXPERT 1829 depends on MTRR 1830 ---help--- 1831 Use PAT attributes to setup page level cache control. 1832 1833 PATs are the modern equivalents of MTRRs and are much more 1834 flexible than MTRRs. 1835 1836 Say N here if you see bootup problems (boot crash, boot hang, 1837 spontaneous reboots) or a non-working video driver. 1838 1839 If unsure, say Y. 1840 1841config ARCH_USES_PG_UNCACHED 1842 def_bool y 1843 depends on X86_PAT 1844 1845config ARCH_RANDOM 1846 def_bool y 1847 prompt "x86 architectural random number generator" if EXPERT 1848 ---help--- 1849 Enable the x86 architectural RDRAND instruction 1850 (Intel Bull Mountain technology) to generate random numbers. 1851 If supported, this is a high bandwidth, cryptographically 1852 secure hardware random number generator. 1853 1854config X86_SMAP 1855 def_bool y 1856 prompt "Supervisor Mode Access Prevention" if EXPERT 1857 ---help--- 1858 Supervisor Mode Access Prevention (SMAP) is a security 1859 feature in newer Intel processors. There is a small 1860 performance cost if this enabled and turned on; there is 1861 also a small increase in the kernel size if this is enabled. 1862 1863 If unsure, say Y. 1864 1865config X86_INTEL_UMIP 1866 def_bool y 1867 depends on CPU_SUP_INTEL 1868 prompt "Intel User Mode Instruction Prevention" if EXPERT 1869 ---help--- 1870 The User Mode Instruction Prevention (UMIP) is a security 1871 feature in newer Intel processors. If enabled, a general 1872 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1873 or STR instructions are executed in user mode. These instructions 1874 unnecessarily expose information about the hardware state. 1875 1876 The vast majority of applications do not use these instructions. 1877 For the very few that do, software emulation is provided in 1878 specific cases in protected and virtual-8086 modes. Emulated 1879 results are dummy. 1880 1881config X86_INTEL_MPX 1882 prompt "Intel MPX (Memory Protection Extensions)" 1883 def_bool n 1884 # Note: only available in 64-bit mode due to VMA flags shortage 1885 depends on CPU_SUP_INTEL && X86_64 1886 select ARCH_USES_HIGH_VMA_FLAGS 1887 ---help--- 1888 MPX provides hardware features that can be used in 1889 conjunction with compiler-instrumented code to check 1890 memory references. It is designed to detect buffer 1891 overflow or underflow bugs. 1892 1893 This option enables running applications which are 1894 instrumented or otherwise use MPX. It does not use MPX 1895 itself inside the kernel or to protect the kernel 1896 against bad memory references. 1897 1898 Enabling this option will make the kernel larger: 1899 ~8k of kernel text and 36 bytes of data on a 64-bit 1900 defconfig. It adds a long to the 'mm_struct' which 1901 will increase the kernel memory overhead of each 1902 process and adds some branches to paths used during 1903 exec() and munmap(). 1904 1905 For details, see Documentation/x86/intel_mpx.txt 1906 1907 If unsure, say N. 1908 1909config X86_INTEL_MEMORY_PROTECTION_KEYS 1910 prompt "Intel Memory Protection Keys" 1911 def_bool y 1912 # Note: only available in 64-bit mode 1913 depends on CPU_SUP_INTEL && X86_64 1914 select ARCH_USES_HIGH_VMA_FLAGS 1915 select ARCH_HAS_PKEYS 1916 ---help--- 1917 Memory Protection Keys provides a mechanism for enforcing 1918 page-based protections, but without requiring modification of the 1919 page tables when an application changes protection domains. 1920 1921 For details, see Documentation/x86/protection-keys.txt 1922 1923 If unsure, say y. 1924 1925config EFI 1926 bool "EFI runtime service support" 1927 depends on ACPI 1928 select UCS2_STRING 1929 select EFI_RUNTIME_WRAPPERS 1930 ---help--- 1931 This enables the kernel to use EFI runtime services that are 1932 available (such as the EFI variable services). 1933 1934 This option is only useful on systems that have EFI firmware. 1935 In addition, you should use the latest ELILO loader available 1936 at <http://elilo.sourceforge.net> in order to take advantage 1937 of EFI runtime services. However, even with this option, the 1938 resultant kernel should continue to boot on existing non-EFI 1939 platforms. 1940 1941config EFI_STUB 1942 bool "EFI stub support" 1943 depends on EFI && !X86_USE_3DNOW 1944 select RELOCATABLE 1945 ---help--- 1946 This kernel feature allows a bzImage to be loaded directly 1947 by EFI firmware without the use of a bootloader. 1948 1949 See Documentation/efi-stub.txt for more information. 1950 1951config EFI_MIXED 1952 bool "EFI mixed-mode support" 1953 depends on EFI_STUB && X86_64 1954 ---help--- 1955 Enabling this feature allows a 64-bit kernel to be booted 1956 on a 32-bit firmware, provided that your CPU supports 64-bit 1957 mode. 1958 1959 Note that it is not possible to boot a mixed-mode enabled 1960 kernel via the EFI boot stub - a bootloader that supports 1961 the EFI handover protocol must be used. 1962 1963 If unsure, say N. 1964 1965config SECCOMP 1966 def_bool y 1967 prompt "Enable seccomp to safely compute untrusted bytecode" 1968 ---help--- 1969 This kernel feature is useful for number crunching applications 1970 that may need to compute untrusted bytecode during their 1971 execution. By using pipes or other transports made available to 1972 the process as file descriptors supporting the read/write 1973 syscalls, it's possible to isolate those applications in 1974 their own address space using seccomp. Once seccomp is 1975 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1976 and the task is only allowed to execute a few safe syscalls 1977 defined by each seccomp mode. 1978 1979 If unsure, say Y. Only embedded should say N here. 1980 1981source "kernel/Kconfig.hz" 1982 1983config KEXEC 1984 bool "kexec system call" 1985 select KEXEC_CORE 1986 ---help--- 1987 kexec is a system call that implements the ability to shutdown your 1988 current kernel, and to start another kernel. It is like a reboot 1989 but it is independent of the system firmware. And like a reboot 1990 you can start any kernel with it, not just Linux. 1991 1992 The name comes from the similarity to the exec system call. 1993 1994 It is an ongoing process to be certain the hardware in a machine 1995 is properly shutdown, so do not be surprised if this code does not 1996 initially work for you. As of this writing the exact hardware 1997 interface is strongly in flux, so no good recommendation can be 1998 made. 1999 2000config KEXEC_FILE 2001 bool "kexec file based system call" 2002 select KEXEC_CORE 2003 select BUILD_BIN2C 2004 depends on X86_64 2005 depends on CRYPTO=y 2006 depends on CRYPTO_SHA256=y 2007 ---help--- 2008 This is new version of kexec system call. This system call is 2009 file based and takes file descriptors as system call argument 2010 for kernel and initramfs as opposed to list of segments as 2011 accepted by previous system call. 2012 2013config ARCH_HAS_KEXEC_PURGATORY 2014 def_bool KEXEC_FILE 2015 2016config KEXEC_VERIFY_SIG 2017 bool "Verify kernel signature during kexec_file_load() syscall" 2018 depends on KEXEC_FILE 2019 ---help--- 2020 This option makes kernel signature verification mandatory for 2021 the kexec_file_load() syscall. 2022 2023 In addition to that option, you need to enable signature 2024 verification for the corresponding kernel image type being 2025 loaded in order for this to work. 2026 2027config KEXEC_BZIMAGE_VERIFY_SIG 2028 bool "Enable bzImage signature verification support" 2029 depends on KEXEC_VERIFY_SIG 2030 depends on SIGNED_PE_FILE_VERIFICATION 2031 select SYSTEM_TRUSTED_KEYRING 2032 ---help--- 2033 Enable bzImage signature verification support. 2034 2035config CRASH_DUMP 2036 bool "kernel crash dumps" 2037 depends on X86_64 || (X86_32 && HIGHMEM) 2038 ---help--- 2039 Generate crash dump after being started by kexec. 2040 This should be normally only set in special crash dump kernels 2041 which are loaded in the main kernel with kexec-tools into 2042 a specially reserved region and then later executed after 2043 a crash by kdump/kexec. The crash dump kernel must be compiled 2044 to a memory address not used by the main kernel or BIOS using 2045 PHYSICAL_START, or it must be built as a relocatable image 2046 (CONFIG_RELOCATABLE=y). 2047 For more details see Documentation/kdump/kdump.txt 2048 2049config KEXEC_JUMP 2050 bool "kexec jump" 2051 depends on KEXEC && HIBERNATION 2052 ---help--- 2053 Jump between original kernel and kexeced kernel and invoke 2054 code in physical address mode via KEXEC 2055 2056config PHYSICAL_START 2057 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2058 default "0x1000000" 2059 ---help--- 2060 This gives the physical address where the kernel is loaded. 2061 2062 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2063 bzImage will decompress itself to above physical address and 2064 run from there. Otherwise, bzImage will run from the address where 2065 it has been loaded by the boot loader and will ignore above physical 2066 address. 2067 2068 In normal kdump cases one does not have to set/change this option 2069 as now bzImage can be compiled as a completely relocatable image 2070 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2071 address. This option is mainly useful for the folks who don't want 2072 to use a bzImage for capturing the crash dump and want to use a 2073 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2074 to be specifically compiled to run from a specific memory area 2075 (normally a reserved region) and this option comes handy. 2076 2077 So if you are using bzImage for capturing the crash dump, 2078 leave the value here unchanged to 0x1000000 and set 2079 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2080 for capturing the crash dump change this value to start of 2081 the reserved region. In other words, it can be set based on 2082 the "X" value as specified in the "crashkernel=YM@XM" 2083 command line boot parameter passed to the panic-ed 2084 kernel. Please take a look at Documentation/kdump/kdump.txt 2085 for more details about crash dumps. 2086 2087 Usage of bzImage for capturing the crash dump is recommended as 2088 one does not have to build two kernels. Same kernel can be used 2089 as production kernel and capture kernel. Above option should have 2090 gone away after relocatable bzImage support is introduced. But it 2091 is present because there are users out there who continue to use 2092 vmlinux for dump capture. This option should go away down the 2093 line. 2094 2095 Don't change this unless you know what you are doing. 2096 2097config RELOCATABLE 2098 bool "Build a relocatable kernel" 2099 default y 2100 ---help--- 2101 This builds a kernel image that retains relocation information 2102 so it can be loaded someplace besides the default 1MB. 2103 The relocations tend to make the kernel binary about 10% larger, 2104 but are discarded at runtime. 2105 2106 One use is for the kexec on panic case where the recovery kernel 2107 must live at a different physical address than the primary 2108 kernel. 2109 2110 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2111 it has been loaded at and the compile time physical address 2112 (CONFIG_PHYSICAL_START) is used as the minimum location. 2113 2114config RANDOMIZE_BASE 2115 bool "Randomize the address of the kernel image (KASLR)" 2116 depends on RELOCATABLE 2117 default y 2118 ---help--- 2119 In support of Kernel Address Space Layout Randomization (KASLR), 2120 this randomizes the physical address at which the kernel image 2121 is decompressed and the virtual address where the kernel 2122 image is mapped, as a security feature that deters exploit 2123 attempts relying on knowledge of the location of kernel 2124 code internals. 2125 2126 On 64-bit, the kernel physical and virtual addresses are 2127 randomized separately. The physical address will be anywhere 2128 between 16MB and the top of physical memory (up to 64TB). The 2129 virtual address will be randomized from 16MB up to 1GB (9 bits 2130 of entropy). Note that this also reduces the memory space 2131 available to kernel modules from 1.5GB to 1GB. 2132 2133 On 32-bit, the kernel physical and virtual addresses are 2134 randomized together. They will be randomized from 16MB up to 2135 512MB (8 bits of entropy). 2136 2137 Entropy is generated using the RDRAND instruction if it is 2138 supported. If RDTSC is supported, its value is mixed into 2139 the entropy pool as well. If neither RDRAND nor RDTSC are 2140 supported, then entropy is read from the i8254 timer. The 2141 usable entropy is limited by the kernel being built using 2142 2GB addressing, and that PHYSICAL_ALIGN must be at a 2143 minimum of 2MB. As a result, only 10 bits of entropy are 2144 theoretically possible, but the implementations are further 2145 limited due to memory layouts. 2146 2147 If unsure, say Y. 2148 2149# Relocation on x86 needs some additional build support 2150config X86_NEED_RELOCS 2151 def_bool y 2152 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2153 2154config PHYSICAL_ALIGN 2155 hex "Alignment value to which kernel should be aligned" 2156 default "0x200000" 2157 range 0x2000 0x1000000 if X86_32 2158 range 0x200000 0x1000000 if X86_64 2159 ---help--- 2160 This value puts the alignment restrictions on physical address 2161 where kernel is loaded and run from. Kernel is compiled for an 2162 address which meets above alignment restriction. 2163 2164 If bootloader loads the kernel at a non-aligned address and 2165 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2166 address aligned to above value and run from there. 2167 2168 If bootloader loads the kernel at a non-aligned address and 2169 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2170 load address and decompress itself to the address it has been 2171 compiled for and run from there. The address for which kernel is 2172 compiled already meets above alignment restrictions. Hence the 2173 end result is that kernel runs from a physical address meeting 2174 above alignment restrictions. 2175 2176 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2177 this value must be a multiple of 0x200000. 2178 2179 Don't change this unless you know what you are doing. 2180 2181config DYNAMIC_MEMORY_LAYOUT 2182 bool 2183 ---help--- 2184 This option makes base addresses of vmalloc and vmemmap as well as 2185 __PAGE_OFFSET movable during boot. 2186 2187config RANDOMIZE_MEMORY 2188 bool "Randomize the kernel memory sections" 2189 depends on X86_64 2190 depends on RANDOMIZE_BASE 2191 select DYNAMIC_MEMORY_LAYOUT 2192 default RANDOMIZE_BASE 2193 ---help--- 2194 Randomizes the base virtual address of kernel memory sections 2195 (physical memory mapping, vmalloc & vmemmap). This security feature 2196 makes exploits relying on predictable memory locations less reliable. 2197 2198 The order of allocations remains unchanged. Entropy is generated in 2199 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2200 configuration have in average 30,000 different possible virtual 2201 addresses for each memory section. 2202 2203 If unsure, say Y. 2204 2205config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2206 hex "Physical memory mapping padding" if EXPERT 2207 depends on RANDOMIZE_MEMORY 2208 default "0xa" if MEMORY_HOTPLUG 2209 default "0x0" 2210 range 0x1 0x40 if MEMORY_HOTPLUG 2211 range 0x0 0x40 2212 ---help--- 2213 Define the padding in terabytes added to the existing physical 2214 memory size during kernel memory randomization. It is useful 2215 for memory hotplug support but reduces the entropy available for 2216 address randomization. 2217 2218 If unsure, leave at the default value. 2219 2220config HOTPLUG_CPU 2221 bool "Support for hot-pluggable CPUs" 2222 depends on SMP 2223 ---help--- 2224 Say Y here to allow turning CPUs off and on. CPUs can be 2225 controlled through /sys/devices/system/cpu. 2226 ( Note: power management support will enable this option 2227 automatically on SMP systems. ) 2228 Say N if you want to disable CPU hotplug. 2229 2230config BOOTPARAM_HOTPLUG_CPU0 2231 bool "Set default setting of cpu0_hotpluggable" 2232 depends on HOTPLUG_CPU 2233 ---help--- 2234 Set whether default state of cpu0_hotpluggable is on or off. 2235 2236 Say Y here to enable CPU0 hotplug by default. If this switch 2237 is turned on, there is no need to give cpu0_hotplug kernel 2238 parameter and the CPU0 hotplug feature is enabled by default. 2239 2240 Please note: there are two known CPU0 dependencies if you want 2241 to enable the CPU0 hotplug feature either by this switch or by 2242 cpu0_hotplug kernel parameter. 2243 2244 First, resume from hibernate or suspend always starts from CPU0. 2245 So hibernate and suspend are prevented if CPU0 is offline. 2246 2247 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2248 offline if any interrupt can not migrate out of CPU0. There may 2249 be other CPU0 dependencies. 2250 2251 Please make sure the dependencies are under your control before 2252 you enable this feature. 2253 2254 Say N if you don't want to enable CPU0 hotplug feature by default. 2255 You still can enable the CPU0 hotplug feature at boot by kernel 2256 parameter cpu0_hotplug. 2257 2258config DEBUG_HOTPLUG_CPU0 2259 def_bool n 2260 prompt "Debug CPU0 hotplug" 2261 depends on HOTPLUG_CPU 2262 ---help--- 2263 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2264 soon as possible and boots up userspace with CPU0 offlined. User 2265 can online CPU0 back after boot time. 2266 2267 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2268 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2269 compilation or giving cpu0_hotplug kernel parameter at boot. 2270 2271 If unsure, say N. 2272 2273config COMPAT_VDSO 2274 def_bool n 2275 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2276 depends on COMPAT_32 2277 ---help--- 2278 Certain buggy versions of glibc will crash if they are 2279 presented with a 32-bit vDSO that is not mapped at the address 2280 indicated in its segment table. 2281 2282 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2283 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2284 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2285 the only released version with the bug, but OpenSUSE 9 2286 contains a buggy "glibc 2.3.2". 2287 2288 The symptom of the bug is that everything crashes on startup, saying: 2289 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2290 2291 Saying Y here changes the default value of the vdso32 boot 2292 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2293 This works around the glibc bug but hurts performance. 2294 2295 If unsure, say N: if you are compiling your own kernel, you 2296 are unlikely to be using a buggy version of glibc. 2297 2298choice 2299 prompt "vsyscall table for legacy applications" 2300 depends on X86_64 2301 default LEGACY_VSYSCALL_EMULATE 2302 help 2303 Legacy user code that does not know how to find the vDSO expects 2304 to be able to issue three syscalls by calling fixed addresses in 2305 kernel space. Since this location is not randomized with ASLR, 2306 it can be used to assist security vulnerability exploitation. 2307 2308 This setting can be changed at boot time via the kernel command 2309 line parameter vsyscall=[emulate|none]. 2310 2311 On a system with recent enough glibc (2.14 or newer) and no 2312 static binaries, you can say None without a performance penalty 2313 to improve security. 2314 2315 If unsure, select "Emulate". 2316 2317 config LEGACY_VSYSCALL_EMULATE 2318 bool "Emulate" 2319 help 2320 The kernel traps and emulates calls into the fixed 2321 vsyscall address mapping. This makes the mapping 2322 non-executable, but it still contains known contents, 2323 which could be used in certain rare security vulnerability 2324 exploits. This configuration is recommended when userspace 2325 still uses the vsyscall area. 2326 2327 config LEGACY_VSYSCALL_NONE 2328 bool "None" 2329 help 2330 There will be no vsyscall mapping at all. This will 2331 eliminate any risk of ASLR bypass due to the vsyscall 2332 fixed address mapping. Attempts to use the vsyscalls 2333 will be reported to dmesg, so that either old or 2334 malicious userspace programs can be identified. 2335 2336endchoice 2337 2338config CMDLINE_BOOL 2339 bool "Built-in kernel command line" 2340 ---help--- 2341 Allow for specifying boot arguments to the kernel at 2342 build time. On some systems (e.g. embedded ones), it is 2343 necessary or convenient to provide some or all of the 2344 kernel boot arguments with the kernel itself (that is, 2345 to not rely on the boot loader to provide them.) 2346 2347 To compile command line arguments into the kernel, 2348 set this option to 'Y', then fill in the 2349 boot arguments in CONFIG_CMDLINE. 2350 2351 Systems with fully functional boot loaders (i.e. non-embedded) 2352 should leave this option set to 'N'. 2353 2354config CMDLINE 2355 string "Built-in kernel command string" 2356 depends on CMDLINE_BOOL 2357 default "" 2358 ---help--- 2359 Enter arguments here that should be compiled into the kernel 2360 image and used at boot time. If the boot loader provides a 2361 command line at boot time, it is appended to this string to 2362 form the full kernel command line, when the system boots. 2363 2364 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2365 change this behavior. 2366 2367 In most cases, the command line (whether built-in or provided 2368 by the boot loader) should specify the device for the root 2369 file system. 2370 2371config CMDLINE_OVERRIDE 2372 bool "Built-in command line overrides boot loader arguments" 2373 depends on CMDLINE_BOOL 2374 ---help--- 2375 Set this option to 'Y' to have the kernel ignore the boot loader 2376 command line, and use ONLY the built-in command line. 2377 2378 This is used to work around broken boot loaders. This should 2379 be set to 'N' under normal conditions. 2380 2381config MODIFY_LDT_SYSCALL 2382 bool "Enable the LDT (local descriptor table)" if EXPERT 2383 default y 2384 ---help--- 2385 Linux can allow user programs to install a per-process x86 2386 Local Descriptor Table (LDT) using the modify_ldt(2) system 2387 call. This is required to run 16-bit or segmented code such as 2388 DOSEMU or some Wine programs. It is also used by some very old 2389 threading libraries. 2390 2391 Enabling this feature adds a small amount of overhead to 2392 context switches and increases the low-level kernel attack 2393 surface. Disabling it removes the modify_ldt(2) system call. 2394 2395 Saying 'N' here may make sense for embedded or server kernels. 2396 2397source "kernel/livepatch/Kconfig" 2398 2399endmenu 2400 2401config ARCH_HAS_ADD_PAGES 2402 def_bool y 2403 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2404 2405config ARCH_ENABLE_MEMORY_HOTPLUG 2406 def_bool y 2407 depends on X86_64 || (X86_32 && HIGHMEM) 2408 2409config ARCH_ENABLE_MEMORY_HOTREMOVE 2410 def_bool y 2411 depends on MEMORY_HOTPLUG 2412 2413config USE_PERCPU_NUMA_NODE_ID 2414 def_bool y 2415 depends on NUMA 2416 2417config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2418 def_bool y 2419 depends on X86_64 || X86_PAE 2420 2421config ARCH_ENABLE_HUGEPAGE_MIGRATION 2422 def_bool y 2423 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2424 2425config ARCH_ENABLE_THP_MIGRATION 2426 def_bool y 2427 depends on X86_64 && TRANSPARENT_HUGEPAGE 2428 2429menu "Power management and ACPI options" 2430 2431config ARCH_HIBERNATION_HEADER 2432 def_bool y 2433 depends on HIBERNATION 2434 2435source "kernel/power/Kconfig" 2436 2437source "drivers/acpi/Kconfig" 2438 2439source "drivers/sfi/Kconfig" 2440 2441config X86_APM_BOOT 2442 def_bool y 2443 depends on APM 2444 2445menuconfig APM 2446 tristate "APM (Advanced Power Management) BIOS support" 2447 depends on X86_32 && PM_SLEEP 2448 ---help--- 2449 APM is a BIOS specification for saving power using several different 2450 techniques. This is mostly useful for battery powered laptops with 2451 APM compliant BIOSes. If you say Y here, the system time will be 2452 reset after a RESUME operation, the /proc/apm device will provide 2453 battery status information, and user-space programs will receive 2454 notification of APM "events" (e.g. battery status change). 2455 2456 If you select "Y" here, you can disable actual use of the APM 2457 BIOS by passing the "apm=off" option to the kernel at boot time. 2458 2459 Note that the APM support is almost completely disabled for 2460 machines with more than one CPU. 2461 2462 In order to use APM, you will need supporting software. For location 2463 and more information, read <file:Documentation/power/apm-acpi.txt> 2464 and the Battery Powered Linux mini-HOWTO, available from 2465 <http://www.tldp.org/docs.html#howto>. 2466 2467 This driver does not spin down disk drives (see the hdparm(8) 2468 manpage ("man 8 hdparm") for that), and it doesn't turn off 2469 VESA-compliant "green" monitors. 2470 2471 This driver does not support the TI 4000M TravelMate and the ACER 2472 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2473 desktop machines also don't have compliant BIOSes, and this driver 2474 may cause those machines to panic during the boot phase. 2475 2476 Generally, if you don't have a battery in your machine, there isn't 2477 much point in using this driver and you should say N. If you get 2478 random kernel OOPSes or reboots that don't seem to be related to 2479 anything, try disabling/enabling this option (or disabling/enabling 2480 APM in your BIOS). 2481 2482 Some other things you should try when experiencing seemingly random, 2483 "weird" problems: 2484 2485 1) make sure that you have enough swap space and that it is 2486 enabled. 2487 2) pass the "no-hlt" option to the kernel 2488 3) switch on floating point emulation in the kernel and pass 2489 the "no387" option to the kernel 2490 4) pass the "floppy=nodma" option to the kernel 2491 5) pass the "mem=4M" option to the kernel (thereby disabling 2492 all but the first 4 MB of RAM) 2493 6) make sure that the CPU is not over clocked. 2494 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2495 8) disable the cache from your BIOS settings 2496 9) install a fan for the video card or exchange video RAM 2497 10) install a better fan for the CPU 2498 11) exchange RAM chips 2499 12) exchange the motherboard. 2500 2501 To compile this driver as a module, choose M here: the 2502 module will be called apm. 2503 2504if APM 2505 2506config APM_IGNORE_USER_SUSPEND 2507 bool "Ignore USER SUSPEND" 2508 ---help--- 2509 This option will ignore USER SUSPEND requests. On machines with a 2510 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2511 series notebooks, it is necessary to say Y because of a BIOS bug. 2512 2513config APM_DO_ENABLE 2514 bool "Enable PM at boot time" 2515 ---help--- 2516 Enable APM features at boot time. From page 36 of the APM BIOS 2517 specification: "When disabled, the APM BIOS does not automatically 2518 power manage devices, enter the Standby State, enter the Suspend 2519 State, or take power saving steps in response to CPU Idle calls." 2520 This driver will make CPU Idle calls when Linux is idle (unless this 2521 feature is turned off -- see "Do CPU IDLE calls", below). This 2522 should always save battery power, but more complicated APM features 2523 will be dependent on your BIOS implementation. You may need to turn 2524 this option off if your computer hangs at boot time when using APM 2525 support, or if it beeps continuously instead of suspending. Turn 2526 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2527 T400CDT. This is off by default since most machines do fine without 2528 this feature. 2529 2530config APM_CPU_IDLE 2531 depends on CPU_IDLE 2532 bool "Make CPU Idle calls when idle" 2533 ---help--- 2534 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2535 On some machines, this can activate improved power savings, such as 2536 a slowed CPU clock rate, when the machine is idle. These idle calls 2537 are made after the idle loop has run for some length of time (e.g., 2538 333 mS). On some machines, this will cause a hang at boot time or 2539 whenever the CPU becomes idle. (On machines with more than one CPU, 2540 this option does nothing.) 2541 2542config APM_DISPLAY_BLANK 2543 bool "Enable console blanking using APM" 2544 ---help--- 2545 Enable console blanking using the APM. Some laptops can use this to 2546 turn off the LCD backlight when the screen blanker of the Linux 2547 virtual console blanks the screen. Note that this is only used by 2548 the virtual console screen blanker, and won't turn off the backlight 2549 when using the X Window system. This also doesn't have anything to 2550 do with your VESA-compliant power-saving monitor. Further, this 2551 option doesn't work for all laptops -- it might not turn off your 2552 backlight at all, or it might print a lot of errors to the console, 2553 especially if you are using gpm. 2554 2555config APM_ALLOW_INTS 2556 bool "Allow interrupts during APM BIOS calls" 2557 ---help--- 2558 Normally we disable external interrupts while we are making calls to 2559 the APM BIOS as a measure to lessen the effects of a badly behaving 2560 BIOS implementation. The BIOS should reenable interrupts if it 2561 needs to. Unfortunately, some BIOSes do not -- especially those in 2562 many of the newer IBM Thinkpads. If you experience hangs when you 2563 suspend, try setting this to Y. Otherwise, say N. 2564 2565endif # APM 2566 2567source "drivers/cpufreq/Kconfig" 2568 2569source "drivers/cpuidle/Kconfig" 2570 2571source "drivers/idle/Kconfig" 2572 2573endmenu 2574 2575 2576menu "Bus options (PCI etc.)" 2577 2578choice 2579 prompt "PCI access mode" 2580 depends on X86_32 && PCI 2581 default PCI_GOANY 2582 ---help--- 2583 On PCI systems, the BIOS can be used to detect the PCI devices and 2584 determine their configuration. However, some old PCI motherboards 2585 have BIOS bugs and may crash if this is done. Also, some embedded 2586 PCI-based systems don't have any BIOS at all. Linux can also try to 2587 detect the PCI hardware directly without using the BIOS. 2588 2589 With this option, you can specify how Linux should detect the 2590 PCI devices. If you choose "BIOS", the BIOS will be used, 2591 if you choose "Direct", the BIOS won't be used, and if you 2592 choose "MMConfig", then PCI Express MMCONFIG will be used. 2593 If you choose "Any", the kernel will try MMCONFIG, then the 2594 direct access method and falls back to the BIOS if that doesn't 2595 work. If unsure, go with the default, which is "Any". 2596 2597config PCI_GOBIOS 2598 bool "BIOS" 2599 2600config PCI_GOMMCONFIG 2601 bool "MMConfig" 2602 2603config PCI_GODIRECT 2604 bool "Direct" 2605 2606config PCI_GOOLPC 2607 bool "OLPC XO-1" 2608 depends on OLPC 2609 2610config PCI_GOANY 2611 bool "Any" 2612 2613endchoice 2614 2615config PCI_BIOS 2616 def_bool y 2617 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2618 2619# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2620config PCI_DIRECT 2621 def_bool y 2622 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2623 2624config PCI_MMCONFIG 2625 bool "Support mmconfig PCI config space access" if X86_64 2626 default y 2627 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2628 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2629 2630config PCI_OLPC 2631 def_bool y 2632 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2633 2634config PCI_XEN 2635 def_bool y 2636 depends on PCI && XEN 2637 select SWIOTLB_XEN 2638 2639config MMCONF_FAM10H 2640 def_bool y 2641 depends on X86_64 && PCI_MMCONFIG && ACPI 2642 2643config PCI_CNB20LE_QUIRK 2644 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2645 depends on PCI 2646 help 2647 Read the PCI windows out of the CNB20LE host bridge. This allows 2648 PCI hotplug to work on systems with the CNB20LE chipset which do 2649 not have ACPI. 2650 2651 There's no public spec for this chipset, and this functionality 2652 is known to be incomplete. 2653 2654 You should say N unless you know you need this. 2655 2656config ISA_BUS 2657 bool "ISA bus support on modern systems" if EXPERT 2658 help 2659 Expose ISA bus device drivers and options available for selection and 2660 configuration. Enable this option if your target machine has an ISA 2661 bus. ISA is an older system, displaced by PCI and newer bus 2662 architectures -- if your target machine is modern, it probably does 2663 not have an ISA bus. 2664 2665 If unsure, say N. 2666 2667# x86_64 have no ISA slots, but can have ISA-style DMA. 2668config ISA_DMA_API 2669 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2670 default y 2671 help 2672 Enables ISA-style DMA support for devices requiring such controllers. 2673 If unsure, say Y. 2674 2675if X86_32 2676 2677config ISA 2678 bool "ISA support" 2679 ---help--- 2680 Find out whether you have ISA slots on your motherboard. ISA is the 2681 name of a bus system, i.e. the way the CPU talks to the other stuff 2682 inside your box. Other bus systems are PCI, EISA, MicroChannel 2683 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2684 newer boards don't support it. If you have ISA, say Y, otherwise N. 2685 2686config SCx200 2687 tristate "NatSemi SCx200 support" 2688 ---help--- 2689 This provides basic support for National Semiconductor's 2690 (now AMD's) Geode processors. The driver probes for the 2691 PCI-IDs of several on-chip devices, so its a good dependency 2692 for other scx200_* drivers. 2693 2694 If compiled as a module, the driver is named scx200. 2695 2696config SCx200HR_TIMER 2697 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2698 depends on SCx200 2699 default y 2700 ---help--- 2701 This driver provides a clocksource built upon the on-chip 2702 27MHz high-resolution timer. Its also a workaround for 2703 NSC Geode SC-1100's buggy TSC, which loses time when the 2704 processor goes idle (as is done by the scheduler). The 2705 other workaround is idle=poll boot option. 2706 2707config OLPC 2708 bool "One Laptop Per Child support" 2709 depends on !X86_PAE 2710 select GPIOLIB 2711 select OF 2712 select OF_PROMTREE 2713 select IRQ_DOMAIN 2714 ---help--- 2715 Add support for detecting the unique features of the OLPC 2716 XO hardware. 2717 2718config OLPC_XO1_PM 2719 bool "OLPC XO-1 Power Management" 2720 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2721 ---help--- 2722 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2723 2724config OLPC_XO1_RTC 2725 bool "OLPC XO-1 Real Time Clock" 2726 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2727 ---help--- 2728 Add support for the XO-1 real time clock, which can be used as a 2729 programmable wakeup source. 2730 2731config OLPC_XO1_SCI 2732 bool "OLPC XO-1 SCI extras" 2733 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2734 depends on INPUT=y 2735 select POWER_SUPPLY 2736 ---help--- 2737 Add support for SCI-based features of the OLPC XO-1 laptop: 2738 - EC-driven system wakeups 2739 - Power button 2740 - Ebook switch 2741 - Lid switch 2742 - AC adapter status updates 2743 - Battery status updates 2744 2745config OLPC_XO15_SCI 2746 bool "OLPC XO-1.5 SCI extras" 2747 depends on OLPC && ACPI 2748 select POWER_SUPPLY 2749 ---help--- 2750 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2751 - EC-driven system wakeups 2752 - AC adapter status updates 2753 - Battery status updates 2754 2755config ALIX 2756 bool "PCEngines ALIX System Support (LED setup)" 2757 select GPIOLIB 2758 ---help--- 2759 This option enables system support for the PCEngines ALIX. 2760 At present this just sets up LEDs for GPIO control on 2761 ALIX2/3/6 boards. However, other system specific setup should 2762 get added here. 2763 2764 Note: You must still enable the drivers for GPIO and LED support 2765 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2766 2767 Note: You have to set alix.force=1 for boards with Award BIOS. 2768 2769config NET5501 2770 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2771 select GPIOLIB 2772 ---help--- 2773 This option enables system support for the Soekris Engineering net5501. 2774 2775config GEOS 2776 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2777 select GPIOLIB 2778 depends on DMI 2779 ---help--- 2780 This option enables system support for the Traverse Technologies GEOS. 2781 2782config TS5500 2783 bool "Technologic Systems TS-5500 platform support" 2784 depends on MELAN 2785 select CHECK_SIGNATURE 2786 select NEW_LEDS 2787 select LEDS_CLASS 2788 ---help--- 2789 This option enables system support for the Technologic Systems TS-5500. 2790 2791endif # X86_32 2792 2793config AMD_NB 2794 def_bool y 2795 depends on CPU_SUP_AMD && PCI 2796 2797config X86_SYSFB 2798 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2799 help 2800 Firmwares often provide initial graphics framebuffers so the BIOS, 2801 bootloader or kernel can show basic video-output during boot for 2802 user-guidance and debugging. Historically, x86 used the VESA BIOS 2803 Extensions and EFI-framebuffers for this, which are mostly limited 2804 to x86. 2805 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2806 framebuffers so the new generic system-framebuffer drivers can be 2807 used on x86. If the framebuffer is not compatible with the generic 2808 modes, it is advertised as fallback platform framebuffer so legacy 2809 drivers like efifb, vesafb and uvesafb can pick it up. 2810 If this option is not selected, all system framebuffers are always 2811 marked as fallback platform framebuffers as usual. 2812 2813 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2814 not be able to pick up generic system framebuffers if this option 2815 is selected. You are highly encouraged to enable simplefb as 2816 replacement if you select this option. simplefb can correctly deal 2817 with generic system framebuffers. But you should still keep vesafb 2818 and others enabled as fallback if a system framebuffer is 2819 incompatible with simplefb. 2820 2821 If unsure, say Y. 2822 2823endmenu 2824 2825 2826menu "Binary Emulations" 2827 2828config IA32_EMULATION 2829 bool "IA32 Emulation" 2830 depends on X86_64 2831 select ARCH_WANT_OLD_COMPAT_IPC 2832 select BINFMT_ELF 2833 select COMPAT_BINFMT_ELF 2834 select COMPAT_OLD_SIGACTION 2835 ---help--- 2836 Include code to run legacy 32-bit programs under a 2837 64-bit kernel. You should likely turn this on, unless you're 2838 100% sure that you don't have any 32-bit programs left. 2839 2840config IA32_AOUT 2841 tristate "IA32 a.out support" 2842 depends on IA32_EMULATION 2843 depends on BROKEN 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 "drivers/firmware/Kconfig" 2898 2899source "arch/x86/kvm/Kconfig" 2900