1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_AOUT 18 select HAVE_GENERIC_DMA_COHERENT 19 select MODULES_USE_ELF_REL 20 select OLD_SIGACTION 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select NEED_DMA_MAP_STATE 32 select SWIOTLB 33 select X86_DEV_DMA_OPS 34 select ARCH_HAS_SYSCALL_WRAPPER 35 36# 37# Arch settings 38# 39# ( Note that options that are marked 'if X86_64' could in principle be 40# ported to 32-bit as well. ) 41# 42config X86 43 def_bool y 44 # 45 # Note: keep this list sorted alphabetically 46 # 47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 49 select ANON_INODES 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_NMI 176 select HAVE_OPROFILE 177 select HAVE_OPTPROBES 178 select HAVE_PCSPKR_PLATFORM 179 select HAVE_PERF_EVENTS 180 select HAVE_PERF_EVENTS_NMI 181 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 182 select HAVE_PCI 183 select HAVE_PERF_REGS 184 select HAVE_PERF_USER_STACK_DUMP 185 select HAVE_RCU_TABLE_FREE if PARAVIRT 186 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 187 select HAVE_REGS_AND_STACK_ACCESS_API 188 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 189 select HAVE_FUNCTION_ARG_ACCESS_API 190 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 191 select HAVE_STACK_VALIDATION if X86_64 192 select HAVE_RSEQ 193 select HAVE_SYSCALL_TRACEPOINTS 194 select HAVE_UNSTABLE_SCHED_CLOCK 195 select HAVE_USER_RETURN_NOTIFIER 196 select HOTPLUG_SMT if SMP 197 select IRQ_FORCED_THREADING 198 select NEED_SG_DMA_LENGTH 199 select PCI_DOMAINS if PCI 200 select PCI_LOCKLESS_CONFIG 201 select PERF_EVENTS 202 select RTC_LIB 203 select RTC_MC146818_LIB 204 select SPARSE_IRQ 205 select SRCU 206 select SYSCTL_EXCEPTION_TRACE 207 select THREAD_INFO_IN_TASK 208 select USER_STACKTRACE_SUPPORT 209 select VIRT_TO_BUS 210 select X86_FEATURE_NAMES if PROC_FS 211 212config INSTRUCTION_DECODER 213 def_bool y 214 depends on KPROBES || PERF_EVENTS || UPROBES 215 216config OUTPUT_FORMAT 217 string 218 default "elf32-i386" if X86_32 219 default "elf64-x86-64" if X86_64 220 221config ARCH_DEFCONFIG 222 string 223 default "arch/x86/configs/i386_defconfig" if X86_32 224 default "arch/x86/configs/x86_64_defconfig" if X86_64 225 226config LOCKDEP_SUPPORT 227 def_bool y 228 229config STACKTRACE_SUPPORT 230 def_bool y 231 232config MMU 233 def_bool y 234 235config ARCH_MMAP_RND_BITS_MIN 236 default 28 if 64BIT 237 default 8 238 239config ARCH_MMAP_RND_BITS_MAX 240 default 32 if 64BIT 241 default 16 242 243config ARCH_MMAP_RND_COMPAT_BITS_MIN 244 default 8 245 246config ARCH_MMAP_RND_COMPAT_BITS_MAX 247 default 16 248 249config SBUS 250 bool 251 252config GENERIC_ISA_DMA 253 def_bool y 254 depends on ISA_DMA_API 255 256config GENERIC_BUG 257 def_bool y 258 depends on BUG 259 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 260 261config GENERIC_BUG_RELATIVE_POINTERS 262 bool 263 264config GENERIC_HWEIGHT 265 def_bool y 266 267config ARCH_MAY_HAVE_PC_FDC 268 def_bool y 269 depends on ISA_DMA_API 270 271config RWSEM_XCHGADD_ALGORITHM 272 def_bool y 273 274config GENERIC_CALIBRATE_DELAY 275 def_bool y 276 277config ARCH_HAS_CPU_RELAX 278 def_bool y 279 280config ARCH_HAS_CACHE_LINE_SIZE 281 def_bool y 282 283config ARCH_HAS_FILTER_PGPROT 284 def_bool y 285 286config HAVE_SETUP_PER_CPU_AREA 287 def_bool y 288 289config NEED_PER_CPU_EMBED_FIRST_CHUNK 290 def_bool y 291 292config NEED_PER_CPU_PAGE_FIRST_CHUNK 293 def_bool y 294 295config ARCH_HIBERNATION_POSSIBLE 296 def_bool y 297 298config ARCH_SUSPEND_POSSIBLE 299 def_bool y 300 301config ARCH_WANT_HUGE_PMD_SHARE 302 def_bool y 303 304config ARCH_WANT_GENERAL_HUGETLB 305 def_bool y 306 307config ZONE_DMA32 308 def_bool y if X86_64 309 310config AUDIT_ARCH 311 def_bool y if X86_64 312 313config ARCH_SUPPORTS_OPTIMIZED_INLINING 314 def_bool y 315 316config ARCH_SUPPORTS_DEBUG_PAGEALLOC 317 def_bool y 318 319config KASAN_SHADOW_OFFSET 320 hex 321 depends on KASAN 322 default 0xdffffc0000000000 323 324config HAVE_INTEL_TXT 325 def_bool y 326 depends on INTEL_IOMMU && ACPI 327 328config X86_32_SMP 329 def_bool y 330 depends on X86_32 && SMP 331 332config X86_64_SMP 333 def_bool y 334 depends on X86_64 && SMP 335 336config X86_32_LAZY_GS 337 def_bool y 338 depends on X86_32 && !STACKPROTECTOR 339 340config ARCH_SUPPORTS_UPROBES 341 def_bool y 342 343config FIX_EARLYCON_MEM 344 def_bool y 345 346config DYNAMIC_PHYSICAL_MASK 347 bool 348 349config PGTABLE_LEVELS 350 int 351 default 5 if X86_5LEVEL 352 default 4 if X86_64 353 default 3 if X86_PAE 354 default 2 355 356config CC_HAS_SANE_STACKPROTECTOR 357 bool 358 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 359 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 360 help 361 We have to make sure stack protector is unconditionally disabled if 362 the compiler produces broken code. 363 364menu "Processor type and features" 365 366config ZONE_DMA 367 bool "DMA memory allocation support" if EXPERT 368 default y 369 help 370 DMA memory allocation support allows devices with less than 32-bit 371 addressing to allocate within the first 16MB of address space. 372 Disable if no such devices will be used. 373 374 If unsure, say Y. 375 376config SMP 377 bool "Symmetric multi-processing support" 378 ---help--- 379 This enables support for systems with more than one CPU. If you have 380 a system with only one CPU, say N. If you have a system with more 381 than one CPU, say Y. 382 383 If you say N here, the kernel will run on uni- and multiprocessor 384 machines, but will use only one CPU of a multiprocessor machine. If 385 you say Y here, the kernel will run on many, but not all, 386 uniprocessor machines. On a uniprocessor machine, the kernel 387 will run faster if you say N here. 388 389 Note that if you say Y here and choose architecture "586" or 390 "Pentium" under "Processor family", the kernel will not work on 486 391 architectures. Similarly, multiprocessor kernels for the "PPro" 392 architecture may not work on all Pentium based boards. 393 394 People using multiprocessor machines who say Y here should also say 395 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 396 Management" code will be disabled if you say Y here. 397 398 See also <file:Documentation/x86/i386/IO-APIC.txt>, 399 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 400 <http://www.tldp.org/docs.html#howto>. 401 402 If you don't know what to do here, say N. 403 404config X86_FEATURE_NAMES 405 bool "Processor feature human-readable names" if EMBEDDED 406 default y 407 ---help--- 408 This option compiles in a table of x86 feature bits and corresponding 409 names. This is required to support /proc/cpuinfo and a few kernel 410 messages. You can disable this to save space, at the expense of 411 making those few kernel messages show numeric feature bits instead. 412 413 If in doubt, say Y. 414 415config X86_X2APIC 416 bool "Support x2apic" 417 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 418 ---help--- 419 This enables x2apic support on CPUs that have this feature. 420 421 This allows 32-bit apic IDs (so it can support very large systems), 422 and accesses the local apic via MSRs not via mmio. 423 424 If you don't know what to do here, say N. 425 426config X86_MPPARSE 427 bool "Enable MPS table" if ACPI || SFI 428 default y 429 depends on X86_LOCAL_APIC 430 ---help--- 431 For old smp systems that do not have proper acpi support. Newer systems 432 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 433 434config GOLDFISH 435 def_bool y 436 depends on X86_GOLDFISH 437 438config RETPOLINE 439 bool "Avoid speculative indirect branches in kernel" 440 default y 441 select STACK_VALIDATION if HAVE_STACK_VALIDATION 442 help 443 Compile kernel with the retpoline compiler options to guard against 444 kernel-to-user data leaks by avoiding speculative indirect 445 branches. Requires a compiler with -mindirect-branch=thunk-extern 446 support for full protection. The kernel may run slower. 447 448config RESCTRL 449 bool "Resource Control support" 450 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 451 select KERNFS 452 help 453 Enable Resource Control support. 454 455 Provide support for the allocation and monitoring of system resources 456 usage by the CPU. 457 458 Intel calls this Intel Resource Director Technology 459 (Intel(R) RDT). More information about RDT can be found in the 460 Intel x86 Architecture Software Developer Manual. 461 462 AMD calls this AMD Platform Quality of Service (AMD QoS). 463 More information about AMD QoS can be found in the AMD64 Technology 464 Platform Quality of Service Extensions manual. 465 466 Say N if unsure. 467 468if X86_32 469config X86_BIGSMP 470 bool "Support for big SMP systems with more than 8 CPUs" 471 depends on SMP 472 ---help--- 473 This option is needed for the systems that have more than 8 CPUs 474 475config X86_EXTENDED_PLATFORM 476 bool "Support for extended (non-PC) x86 platforms" 477 default y 478 ---help--- 479 If you disable this option then the kernel will only support 480 standard PC platforms. (which covers the vast majority of 481 systems out there.) 482 483 If you enable this option then you'll be able to select support 484 for the following (non-PC) 32 bit x86 platforms: 485 Goldfish (Android emulator) 486 AMD Elan 487 RDC R-321x SoC 488 SGI 320/540 (Visual Workstation) 489 STA2X11-based (e.g. Northville) 490 Moorestown MID devices 491 492 If you have one of these systems, or if you want to build a 493 generic distribution kernel, say Y here - otherwise say N. 494endif 495 496if X86_64 497config X86_EXTENDED_PLATFORM 498 bool "Support for extended (non-PC) x86 platforms" 499 default y 500 ---help--- 501 If you disable this option then the kernel will only support 502 standard PC platforms. (which covers the vast majority of 503 systems out there.) 504 505 If you enable this option then you'll be able to select support 506 for the following (non-PC) 64 bit x86 platforms: 507 Numascale NumaChip 508 ScaleMP vSMP 509 SGI Ultraviolet 510 511 If you have one of these systems, or if you want to build a 512 generic distribution kernel, say Y here - otherwise say N. 513endif 514# This is an alphabetically sorted list of 64 bit extended platforms 515# Please maintain the alphabetic order if and when there are additions 516config X86_NUMACHIP 517 bool "Numascale NumaChip" 518 depends on X86_64 519 depends on X86_EXTENDED_PLATFORM 520 depends on NUMA 521 depends on SMP 522 depends on X86_X2APIC 523 depends on PCI_MMCONFIG 524 ---help--- 525 Adds support for Numascale NumaChip large-SMP systems. Needed to 526 enable more than ~168 cores. 527 If you don't have one of these, you should say N here. 528 529config X86_VSMP 530 bool "ScaleMP vSMP" 531 select HYPERVISOR_GUEST 532 select PARAVIRT 533 depends on X86_64 && PCI 534 depends on X86_EXTENDED_PLATFORM 535 depends on SMP 536 ---help--- 537 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 538 supposed to run on these EM64T-based machines. Only choose this option 539 if you have one of these machines. 540 541config X86_UV 542 bool "SGI Ultraviolet" 543 depends on X86_64 544 depends on X86_EXTENDED_PLATFORM 545 depends on NUMA 546 depends on EFI 547 depends on X86_X2APIC 548 depends on PCI 549 ---help--- 550 This option is needed in order to support SGI Ultraviolet systems. 551 If you don't have one of these, you should say N here. 552 553# Following is an alphabetically sorted list of 32 bit extended platforms 554# Please maintain the alphabetic order if and when there are additions 555 556config X86_GOLDFISH 557 bool "Goldfish (Virtual Platform)" 558 depends on X86_EXTENDED_PLATFORM 559 ---help--- 560 Enable support for the Goldfish virtual platform used primarily 561 for Android development. Unless you are building for the Android 562 Goldfish emulator say N here. 563 564config X86_INTEL_CE 565 bool "CE4100 TV platform" 566 depends on PCI 567 depends on PCI_GODIRECT 568 depends on X86_IO_APIC 569 depends on X86_32 570 depends on X86_EXTENDED_PLATFORM 571 select X86_REBOOTFIXUPS 572 select OF 573 select OF_EARLY_FLATTREE 574 ---help--- 575 Select for the Intel CE media processor (CE4100) SOC. 576 This option compiles in support for the CE4100 SOC for settop 577 boxes and media devices. 578 579config X86_INTEL_MID 580 bool "Intel MID platform support" 581 depends on X86_EXTENDED_PLATFORM 582 depends on X86_PLATFORM_DEVICES 583 depends on PCI 584 depends on X86_64 || (PCI_GOANY && X86_32) 585 depends on X86_IO_APIC 586 select SFI 587 select I2C 588 select DW_APB_TIMER 589 select APB_TIMER 590 select INTEL_SCU_IPC 591 select MFD_INTEL_MSIC 592 ---help--- 593 Select to build a kernel capable of supporting Intel MID (Mobile 594 Internet Device) platform systems which do not have the PCI legacy 595 interfaces. If you are building for a PC class system say N here. 596 597 Intel MID platforms are based on an Intel processor and chipset which 598 consume less power than most of the x86 derivatives. 599 600config X86_INTEL_QUARK 601 bool "Intel Quark platform support" 602 depends on X86_32 603 depends on X86_EXTENDED_PLATFORM 604 depends on X86_PLATFORM_DEVICES 605 depends on X86_TSC 606 depends on PCI 607 depends on PCI_GOANY 608 depends on X86_IO_APIC 609 select IOSF_MBI 610 select INTEL_IMR 611 select COMMON_CLK 612 ---help--- 613 Select to include support for Quark X1000 SoC. 614 Say Y here if you have a Quark based system such as the Arduino 615 compatible Intel Galileo. 616 617config X86_INTEL_LPSS 618 bool "Intel Low Power Subsystem Support" 619 depends on X86 && ACPI 620 select COMMON_CLK 621 select PINCTRL 622 select IOSF_MBI 623 ---help--- 624 Select to build support for Intel Low Power Subsystem such as 625 found on Intel Lynxpoint PCH. Selecting this option enables 626 things like clock tree (common clock framework) and pincontrol 627 which are needed by the LPSS peripheral drivers. 628 629config X86_AMD_PLATFORM_DEVICE 630 bool "AMD ACPI2Platform devices support" 631 depends on ACPI 632 select COMMON_CLK 633 select PINCTRL 634 ---help--- 635 Select to interpret AMD specific ACPI device to platform device 636 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 637 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 638 implemented under PINCTRL subsystem. 639 640config IOSF_MBI 641 tristate "Intel SoC IOSF Sideband support for SoC platforms" 642 depends on PCI 643 ---help--- 644 This option enables sideband register access support for Intel SoC 645 platforms. On these platforms the IOSF sideband is used in lieu of 646 MSR's for some register accesses, mostly but not limited to thermal 647 and power. Drivers may query the availability of this device to 648 determine if they need the sideband in order to work on these 649 platforms. The sideband is available on the following SoC products. 650 This list is not meant to be exclusive. 651 - BayTrail 652 - Braswell 653 - Quark 654 655 You should say Y if you are running a kernel on one of these SoC's. 656 657config IOSF_MBI_DEBUG 658 bool "Enable IOSF sideband access through debugfs" 659 depends on IOSF_MBI && DEBUG_FS 660 ---help--- 661 Select this option to expose the IOSF sideband access registers (MCR, 662 MDR, MCRX) through debugfs to write and read register information from 663 different units on the SoC. This is most useful for obtaining device 664 state information for debug and analysis. As this is a general access 665 mechanism, users of this option would have specific knowledge of the 666 device they want to access. 667 668 If you don't require the option or are in doubt, say N. 669 670config X86_RDC321X 671 bool "RDC R-321x SoC" 672 depends on X86_32 673 depends on X86_EXTENDED_PLATFORM 674 select M486 675 select X86_REBOOTFIXUPS 676 ---help--- 677 This option is needed for RDC R-321x system-on-chip, also known 678 as R-8610-(G). 679 If you don't have one of these chips, you should say N here. 680 681config X86_32_NON_STANDARD 682 bool "Support non-standard 32-bit SMP architectures" 683 depends on X86_32 && SMP 684 depends on X86_EXTENDED_PLATFORM 685 ---help--- 686 This option compiles in the bigsmp and STA2X11 default 687 subarchitectures. It is intended for a generic binary 688 kernel. If you select them all, kernel will probe it one by 689 one and will fallback to default. 690 691# Alphabetically sorted list of Non standard 32 bit platforms 692 693config X86_SUPPORTS_MEMORY_FAILURE 694 def_bool y 695 # MCE code calls memory_failure(): 696 depends on X86_MCE 697 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 698 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 699 depends on X86_64 || !SPARSEMEM 700 select ARCH_SUPPORTS_MEMORY_FAILURE 701 702config STA2X11 703 bool "STA2X11 Companion Chip Support" 704 depends on X86_32_NON_STANDARD && PCI 705 select ARCH_HAS_PHYS_TO_DMA 706 select X86_DEV_DMA_OPS 707 select X86_DMA_REMAP 708 select SWIOTLB 709 select MFD_STA2X11 710 select GPIOLIB 711 ---help--- 712 This adds support for boards based on the STA2X11 IO-Hub, 713 a.k.a. "ConneXt". The chip is used in place of the standard 714 PC chipset, so all "standard" peripherals are missing. If this 715 option is selected the kernel will still be able to boot on 716 standard PC machines. 717 718config X86_32_IRIS 719 tristate "Eurobraille/Iris poweroff module" 720 depends on X86_32 721 ---help--- 722 The Iris machines from EuroBraille do not have APM or ACPI support 723 to shut themselves down properly. A special I/O sequence is 724 needed to do so, which is what this module does at 725 kernel shutdown. 726 727 This is only for Iris machines from EuroBraille. 728 729 If unused, say N. 730 731config SCHED_OMIT_FRAME_POINTER 732 def_bool y 733 prompt "Single-depth WCHAN output" 734 depends on X86 735 ---help--- 736 Calculate simpler /proc/<PID>/wchan values. If this option 737 is disabled then wchan values will recurse back to the 738 caller function. This provides more accurate wchan values, 739 at the expense of slightly more scheduling overhead. 740 741 If in doubt, say "Y". 742 743menuconfig HYPERVISOR_GUEST 744 bool "Linux guest support" 745 ---help--- 746 Say Y here to enable options for running Linux under various hyper- 747 visors. This option enables basic hypervisor detection and platform 748 setup. 749 750 If you say N, all options in this submenu will be skipped and 751 disabled, and Linux guest support won't be built in. 752 753if HYPERVISOR_GUEST 754 755config PARAVIRT 756 bool "Enable paravirtualization code" 757 ---help--- 758 This changes the kernel so it can modify itself when it is run 759 under a hypervisor, potentially improving performance significantly 760 over full virtualization. However, when run without a hypervisor 761 the kernel is theoretically slower and slightly larger. 762 763config PARAVIRT_XXL 764 bool 765 766config PARAVIRT_DEBUG 767 bool "paravirt-ops debugging" 768 depends on PARAVIRT && DEBUG_KERNEL 769 ---help--- 770 Enable to debug paravirt_ops internals. Specifically, BUG if 771 a paravirt_op is missing when it is called. 772 773config PARAVIRT_SPINLOCKS 774 bool "Paravirtualization layer for spinlocks" 775 depends on PARAVIRT && SMP 776 ---help--- 777 Paravirtualized spinlocks allow a pvops backend to replace the 778 spinlock implementation with something virtualization-friendly 779 (for example, block the virtual CPU rather than spinning). 780 781 It has a minimal impact on native kernels and gives a nice performance 782 benefit on paravirtualized KVM / Xen kernels. 783 784 If you are unsure how to answer this question, answer Y. 785 786config QUEUED_LOCK_STAT 787 bool "Paravirt queued spinlock statistics" 788 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 789 ---help--- 790 Enable the collection of statistical data on the slowpath 791 behavior of paravirtualized queued spinlocks and report 792 them on debugfs. 793 794source "arch/x86/xen/Kconfig" 795 796config KVM_GUEST 797 bool "KVM Guest support (including kvmclock)" 798 depends on PARAVIRT 799 select PARAVIRT_CLOCK 800 default y 801 ---help--- 802 This option enables various optimizations for running under the KVM 803 hypervisor. It includes a paravirtualized clock, so that instead 804 of relying on a PIT (or probably other) emulation by the 805 underlying device model, the host provides the guest with 806 timing infrastructure such as time of day, and system time 807 808config PVH 809 bool "Support for running PVH guests" 810 ---help--- 811 This option enables the PVH entry point for guest virtual machines 812 as specified in the x86/HVM direct boot ABI. 813 814config KVM_DEBUG_FS 815 bool "Enable debug information for KVM Guests in debugfs" 816 depends on KVM_GUEST && DEBUG_FS 817 ---help--- 818 This option enables collection of various statistics for KVM guest. 819 Statistics are displayed in debugfs filesystem. Enabling this option 820 may incur significant overhead. 821 822config PARAVIRT_TIME_ACCOUNTING 823 bool "Paravirtual steal time accounting" 824 depends on PARAVIRT 825 ---help--- 826 Select this option to enable fine granularity task steal time 827 accounting. Time spent executing other tasks in parallel with 828 the current vCPU is discounted from the vCPU power. To account for 829 that, there can be a small performance impact. 830 831 If in doubt, say N here. 832 833config PARAVIRT_CLOCK 834 bool 835 836config JAILHOUSE_GUEST 837 bool "Jailhouse non-root cell support" 838 depends on X86_64 && PCI 839 select X86_PM_TIMER 840 ---help--- 841 This option allows to run Linux as guest in a Jailhouse non-root 842 cell. You can leave this option disabled if you only want to start 843 Jailhouse and run Linux afterwards in the root cell. 844 845endif #HYPERVISOR_GUEST 846 847source "arch/x86/Kconfig.cpu" 848 849config HPET_TIMER 850 def_bool X86_64 851 prompt "HPET Timer Support" if X86_32 852 ---help--- 853 Use the IA-PC HPET (High Precision Event Timer) to manage 854 time in preference to the PIT and RTC, if a HPET is 855 present. 856 HPET is the next generation timer replacing legacy 8254s. 857 The HPET provides a stable time base on SMP 858 systems, unlike the TSC, but it is more expensive to access, 859 as it is off-chip. The interface used is documented 860 in the HPET spec, revision 1. 861 862 You can safely choose Y here. However, HPET will only be 863 activated if the platform and the BIOS support this feature. 864 Otherwise the 8254 will be used for timing services. 865 866 Choose N to continue using the legacy 8254 timer. 867 868config HPET_EMULATE_RTC 869 def_bool y 870 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 871 872config APB_TIMER 873 def_bool y if X86_INTEL_MID 874 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 875 select DW_APB_TIMER 876 depends on X86_INTEL_MID && SFI 877 help 878 APB timer is the replacement for 8254, HPET on X86 MID platforms. 879 The APBT provides a stable time base on SMP 880 systems, unlike the TSC, but it is more expensive to access, 881 as it is off-chip. APB timers are always running regardless of CPU 882 C states, they are used as per CPU clockevent device when possible. 883 884# Mark as expert because too many people got it wrong. 885# The code disables itself when not needed. 886config DMI 887 default y 888 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 889 bool "Enable DMI scanning" if EXPERT 890 ---help--- 891 Enabled scanning of DMI to identify machine quirks. Say Y 892 here unless you have verified that your setup is not 893 affected by entries in the DMI blacklist. Required by PNP 894 BIOS code. 895 896config GART_IOMMU 897 bool "Old AMD GART IOMMU support" 898 select IOMMU_HELPER 899 select SWIOTLB 900 depends on X86_64 && PCI && AMD_NB 901 ---help--- 902 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 903 GART based hardware IOMMUs. 904 905 The GART supports full DMA access for devices with 32-bit access 906 limitations, on systems with more than 3 GB. This is usually needed 907 for USB, sound, many IDE/SATA chipsets and some other devices. 908 909 Newer systems typically have a modern AMD IOMMU, supported via 910 the CONFIG_AMD_IOMMU=y config option. 911 912 In normal configurations this driver is only active when needed: 913 there's more than 3 GB of memory and the system contains a 914 32-bit limited device. 915 916 If unsure, say Y. 917 918config CALGARY_IOMMU 919 bool "IBM Calgary IOMMU support" 920 select IOMMU_HELPER 921 select SWIOTLB 922 depends on X86_64 && PCI 923 ---help--- 924 Support for hardware IOMMUs in IBM's xSeries x366 and x460 925 systems. Needed to run systems with more than 3GB of memory 926 properly with 32-bit PCI devices that do not support DAC 927 (Double Address Cycle). Calgary also supports bus level 928 isolation, where all DMAs pass through the IOMMU. This 929 prevents them from going anywhere except their intended 930 destination. This catches hard-to-find kernel bugs and 931 mis-behaving drivers and devices that do not use the DMA-API 932 properly to set up their DMA buffers. The IOMMU can be 933 turned off at boot time with the iommu=off parameter. 934 Normally the kernel will make the right choice by itself. 935 If unsure, say Y. 936 937config CALGARY_IOMMU_ENABLED_BY_DEFAULT 938 def_bool y 939 prompt "Should Calgary be enabled by default?" 940 depends on CALGARY_IOMMU 941 ---help--- 942 Should Calgary be enabled by default? if you choose 'y', Calgary 943 will be used (if it exists). If you choose 'n', Calgary will not be 944 used even if it exists. If you choose 'n' and would like to use 945 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 946 If unsure, say Y. 947 948config MAXSMP 949 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 950 depends on X86_64 && SMP && DEBUG_KERNEL 951 select CPUMASK_OFFSTACK 952 ---help--- 953 Enable maximum number of CPUS and NUMA Nodes for this architecture. 954 If unsure, say N. 955 956# 957# The maximum number of CPUs supported: 958# 959# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 960# and which can be configured interactively in the 961# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 962# 963# The ranges are different on 32-bit and 64-bit kernels, depending on 964# hardware capabilities and scalability features of the kernel. 965# 966# ( If MAXSMP is enabled we just use the highest possible value and disable 967# interactive configuration. ) 968# 969 970config NR_CPUS_RANGE_BEGIN 971 int 972 default NR_CPUS_RANGE_END if MAXSMP 973 default 1 if !SMP 974 default 2 975 976config NR_CPUS_RANGE_END 977 int 978 depends on X86_32 979 default 64 if SMP && X86_BIGSMP 980 default 8 if SMP && !X86_BIGSMP 981 default 1 if !SMP 982 983config NR_CPUS_RANGE_END 984 int 985 depends on X86_64 986 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 987 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 988 default 1 if !SMP 989 990config NR_CPUS_DEFAULT 991 int 992 depends on X86_32 993 default 32 if X86_BIGSMP 994 default 8 if SMP 995 default 1 if !SMP 996 997config NR_CPUS_DEFAULT 998 int 999 depends on X86_64 1000 default 8192 if MAXSMP 1001 default 64 if SMP 1002 default 1 if !SMP 1003 1004config NR_CPUS 1005 int "Maximum number of CPUs" if SMP && !MAXSMP 1006 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1007 default NR_CPUS_DEFAULT 1008 ---help--- 1009 This allows you to specify the maximum number of CPUs which this 1010 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1011 supported value is 8192, otherwise the maximum value is 512. The 1012 minimum value which makes sense is 2. 1013 1014 This is purely to save memory: each supported CPU adds about 8KB 1015 to the kernel image. 1016 1017config SCHED_SMT 1018 def_bool y if SMP 1019 1020config SCHED_MC 1021 def_bool y 1022 prompt "Multi-core scheduler support" 1023 depends on SMP 1024 ---help--- 1025 Multi-core scheduler support improves the CPU scheduler's decision 1026 making when dealing with multi-core CPU chips at a cost of slightly 1027 increased overhead in some places. If unsure say N here. 1028 1029config SCHED_MC_PRIO 1030 bool "CPU core priorities scheduler support" 1031 depends on SCHED_MC && CPU_SUP_INTEL 1032 select X86_INTEL_PSTATE 1033 select CPU_FREQ 1034 default y 1035 ---help--- 1036 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1037 core ordering determined at manufacturing time, which allows 1038 certain cores to reach higher turbo frequencies (when running 1039 single threaded workloads) than others. 1040 1041 Enabling this kernel feature teaches the scheduler about 1042 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1043 scheduler's CPU selection logic accordingly, so that higher 1044 overall system performance can be achieved. 1045 1046 This feature will have no effect on CPUs without this feature. 1047 1048 If unsure say Y here. 1049 1050config UP_LATE_INIT 1051 def_bool y 1052 depends on !SMP && X86_LOCAL_APIC 1053 1054config X86_UP_APIC 1055 bool "Local APIC support on uniprocessors" if !PCI_MSI 1056 default PCI_MSI 1057 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1058 ---help--- 1059 A local APIC (Advanced Programmable Interrupt Controller) is an 1060 integrated interrupt controller in the CPU. If you have a single-CPU 1061 system which has a processor with a local APIC, you can say Y here to 1062 enable and use it. If you say Y here even though your machine doesn't 1063 have a local APIC, then the kernel will still run with no slowdown at 1064 all. The local APIC supports CPU-generated self-interrupts (timer, 1065 performance counters), and the NMI watchdog which detects hard 1066 lockups. 1067 1068config X86_UP_IOAPIC 1069 bool "IO-APIC support on uniprocessors" 1070 depends on X86_UP_APIC 1071 ---help--- 1072 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1073 SMP-capable replacement for PC-style interrupt controllers. Most 1074 SMP systems and many recent uniprocessor systems have one. 1075 1076 If you have a single-CPU system with an IO-APIC, you can say Y here 1077 to use it. If you say Y here even though your machine doesn't have 1078 an IO-APIC, then the kernel will still run with no slowdown at all. 1079 1080config X86_LOCAL_APIC 1081 def_bool y 1082 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1083 select IRQ_DOMAIN_HIERARCHY 1084 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1085 1086config X86_IO_APIC 1087 def_bool y 1088 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1089 1090config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1091 bool "Reroute for broken boot IRQs" 1092 depends on X86_IO_APIC 1093 ---help--- 1094 This option enables a workaround that fixes a source of 1095 spurious interrupts. This is recommended when threaded 1096 interrupt handling is used on systems where the generation of 1097 superfluous "boot interrupts" cannot be disabled. 1098 1099 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1100 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1101 kernel does during interrupt handling). On chipsets where this 1102 boot IRQ generation cannot be disabled, this workaround keeps 1103 the original IRQ line masked so that only the equivalent "boot 1104 IRQ" is delivered to the CPUs. The workaround also tells the 1105 kernel to set up the IRQ handler on the boot IRQ line. In this 1106 way only one interrupt is delivered to the kernel. Otherwise 1107 the spurious second interrupt may cause the kernel to bring 1108 down (vital) interrupt lines. 1109 1110 Only affects "broken" chipsets. Interrupt sharing may be 1111 increased on these systems. 1112 1113config X86_MCE 1114 bool "Machine Check / overheating reporting" 1115 select GENERIC_ALLOCATOR 1116 default y 1117 ---help--- 1118 Machine Check support allows the processor to notify the 1119 kernel if it detects a problem (e.g. overheating, data corruption). 1120 The action the kernel takes depends on the severity of the problem, 1121 ranging from warning messages to halting the machine. 1122 1123config X86_MCELOG_LEGACY 1124 bool "Support for deprecated /dev/mcelog character device" 1125 depends on X86_MCE 1126 ---help--- 1127 Enable support for /dev/mcelog which is needed by the old mcelog 1128 userspace logging daemon. Consider switching to the new generation 1129 rasdaemon solution. 1130 1131config X86_MCE_INTEL 1132 def_bool y 1133 prompt "Intel MCE features" 1134 depends on X86_MCE && X86_LOCAL_APIC 1135 ---help--- 1136 Additional support for intel specific MCE features such as 1137 the thermal monitor. 1138 1139config X86_MCE_AMD 1140 def_bool y 1141 prompt "AMD MCE features" 1142 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1143 ---help--- 1144 Additional support for AMD specific MCE features such as 1145 the DRAM Error Threshold. 1146 1147config X86_ANCIENT_MCE 1148 bool "Support for old Pentium 5 / WinChip machine checks" 1149 depends on X86_32 && X86_MCE 1150 ---help--- 1151 Include support for machine check handling on old Pentium 5 or WinChip 1152 systems. These typically need to be enabled explicitly on the command 1153 line. 1154 1155config X86_MCE_THRESHOLD 1156 depends on X86_MCE_AMD || X86_MCE_INTEL 1157 def_bool y 1158 1159config X86_MCE_INJECT 1160 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1161 tristate "Machine check injector support" 1162 ---help--- 1163 Provide support for injecting machine checks for testing purposes. 1164 If you don't know what a machine check is and you don't do kernel 1165 QA it is safe to say n. 1166 1167config X86_THERMAL_VECTOR 1168 def_bool y 1169 depends on X86_MCE_INTEL 1170 1171source "arch/x86/events/Kconfig" 1172 1173config X86_LEGACY_VM86 1174 bool "Legacy VM86 support" 1175 depends on X86_32 1176 ---help--- 1177 This option allows user programs to put the CPU into V8086 1178 mode, which is an 80286-era approximation of 16-bit real mode. 1179 1180 Some very old versions of X and/or vbetool require this option 1181 for user mode setting. Similarly, DOSEMU will use it if 1182 available to accelerate real mode DOS programs. However, any 1183 recent version of DOSEMU, X, or vbetool should be fully 1184 functional even without kernel VM86 support, as they will all 1185 fall back to software emulation. Nevertheless, if you are using 1186 a 16-bit DOS program where 16-bit performance matters, vm86 1187 mode might be faster than emulation and you might want to 1188 enable this option. 1189 1190 Note that any app that works on a 64-bit kernel is unlikely to 1191 need this option, as 64-bit kernels don't, and can't, support 1192 V8086 mode. This option is also unrelated to 16-bit protected 1193 mode and is not needed to run most 16-bit programs under Wine. 1194 1195 Enabling this option increases the complexity of the kernel 1196 and slows down exception handling a tiny bit. 1197 1198 If unsure, say N here. 1199 1200config VM86 1201 bool 1202 default X86_LEGACY_VM86 1203 1204config X86_16BIT 1205 bool "Enable support for 16-bit segments" if EXPERT 1206 default y 1207 depends on MODIFY_LDT_SYSCALL 1208 ---help--- 1209 This option is required by programs like Wine to run 16-bit 1210 protected mode legacy code on x86 processors. Disabling 1211 this option saves about 300 bytes on i386, or around 6K text 1212 plus 16K runtime memory on x86-64, 1213 1214config X86_ESPFIX32 1215 def_bool y 1216 depends on X86_16BIT && X86_32 1217 1218config X86_ESPFIX64 1219 def_bool y 1220 depends on X86_16BIT && X86_64 1221 1222config X86_VSYSCALL_EMULATION 1223 bool "Enable vsyscall emulation" if EXPERT 1224 default y 1225 depends on X86_64 1226 ---help--- 1227 This enables emulation of the legacy vsyscall page. Disabling 1228 it is roughly equivalent to booting with vsyscall=none, except 1229 that it will also disable the helpful warning if a program 1230 tries to use a vsyscall. With this option set to N, offending 1231 programs will just segfault, citing addresses of the form 1232 0xffffffffff600?00. 1233 1234 This option is required by many programs built before 2013, and 1235 care should be used even with newer programs if set to N. 1236 1237 Disabling this option saves about 7K of kernel size and 1238 possibly 4K of additional runtime pagetable memory. 1239 1240config TOSHIBA 1241 tristate "Toshiba Laptop support" 1242 depends on X86_32 1243 ---help--- 1244 This adds a driver to safely access the System Management Mode of 1245 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1246 not work on models with a Phoenix BIOS. The System Management Mode 1247 is used to set the BIOS and power saving options on Toshiba portables. 1248 1249 For information on utilities to make use of this driver see the 1250 Toshiba Linux utilities web site at: 1251 <http://www.buzzard.org.uk/toshiba/>. 1252 1253 Say Y if you intend to run this kernel on a Toshiba portable. 1254 Say N otherwise. 1255 1256config I8K 1257 tristate "Dell i8k legacy laptop support" 1258 select HWMON 1259 select SENSORS_DELL_SMM 1260 ---help--- 1261 This option enables legacy /proc/i8k userspace interface in hwmon 1262 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1263 temperature and allows controlling fan speeds of Dell laptops via 1264 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1265 it reports also power and hotkey status. For fan speed control is 1266 needed userspace package i8kutils. 1267 1268 Say Y if you intend to run this kernel on old Dell laptops or want to 1269 use userspace package i8kutils. 1270 Say N otherwise. 1271 1272config X86_REBOOTFIXUPS 1273 bool "Enable X86 board specific fixups for reboot" 1274 depends on X86_32 1275 ---help--- 1276 This enables chipset and/or board specific fixups to be done 1277 in order to get reboot to work correctly. This is only needed on 1278 some combinations of hardware and BIOS. The symptom, for which 1279 this config is intended, is when reboot ends with a stalled/hung 1280 system. 1281 1282 Currently, the only fixup is for the Geode machines using 1283 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1284 1285 Say Y if you want to enable the fixup. Currently, it's safe to 1286 enable this option even if you don't need it. 1287 Say N otherwise. 1288 1289config MICROCODE 1290 bool "CPU microcode loading support" 1291 default y 1292 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1293 select FW_LOADER 1294 ---help--- 1295 If you say Y here, you will be able to update the microcode on 1296 Intel and AMD processors. The Intel support is for the IA32 family, 1297 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1298 AMD support is for families 0x10 and later. You will obviously need 1299 the actual microcode binary data itself which is not shipped with 1300 the Linux kernel. 1301 1302 The preferred method to load microcode from a detached initrd is described 1303 in Documentation/x86/microcode.txt. For that you need to enable 1304 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1305 initrd for microcode blobs. 1306 1307 In addition, you can build the microcode into the kernel. For that you 1308 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1309 config option. 1310 1311config MICROCODE_INTEL 1312 bool "Intel microcode loading support" 1313 depends on MICROCODE 1314 default MICROCODE 1315 select FW_LOADER 1316 ---help--- 1317 This options enables microcode patch loading support for Intel 1318 processors. 1319 1320 For the current Intel microcode data package go to 1321 <https://downloadcenter.intel.com> and search for 1322 'Linux Processor Microcode Data File'. 1323 1324config MICROCODE_AMD 1325 bool "AMD microcode loading support" 1326 depends on MICROCODE 1327 select FW_LOADER 1328 ---help--- 1329 If you select this option, microcode patch loading support for AMD 1330 processors will be enabled. 1331 1332config MICROCODE_OLD_INTERFACE 1333 def_bool y 1334 depends on MICROCODE 1335 1336config X86_MSR 1337 tristate "/dev/cpu/*/msr - Model-specific register support" 1338 ---help--- 1339 This device gives privileged processes access to the x86 1340 Model-Specific Registers (MSRs). It is a character device with 1341 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1342 MSR accesses are directed to a specific CPU on multi-processor 1343 systems. 1344 1345config X86_CPUID 1346 tristate "/dev/cpu/*/cpuid - CPU information support" 1347 ---help--- 1348 This device gives processes access to the x86 CPUID instruction to 1349 be executed on a specific processor. It is a character device 1350 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1351 /dev/cpu/31/cpuid. 1352 1353choice 1354 prompt "High Memory Support" 1355 default HIGHMEM4G 1356 depends on X86_32 1357 1358config NOHIGHMEM 1359 bool "off" 1360 ---help--- 1361 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1362 However, the address space of 32-bit x86 processors is only 4 1363 Gigabytes large. That means that, if you have a large amount of 1364 physical memory, not all of it can be "permanently mapped" by the 1365 kernel. The physical memory that's not permanently mapped is called 1366 "high memory". 1367 1368 If you are compiling a kernel which will never run on a machine with 1369 more than 1 Gigabyte total physical RAM, answer "off" here (default 1370 choice and suitable for most users). This will result in a "3GB/1GB" 1371 split: 3GB are mapped so that each process sees a 3GB virtual memory 1372 space and the remaining part of the 4GB virtual memory space is used 1373 by the kernel to permanently map as much physical memory as 1374 possible. 1375 1376 If the machine has between 1 and 4 Gigabytes physical RAM, then 1377 answer "4GB" here. 1378 1379 If more than 4 Gigabytes is used then answer "64GB" here. This 1380 selection turns Intel PAE (Physical Address Extension) mode on. 1381 PAE implements 3-level paging on IA32 processors. PAE is fully 1382 supported by Linux, PAE mode is implemented on all recent Intel 1383 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1384 then the kernel will not boot on CPUs that don't support PAE! 1385 1386 The actual amount of total physical memory will either be 1387 auto detected or can be forced by using a kernel command line option 1388 such as "mem=256M". (Try "man bootparam" or see the documentation of 1389 your boot loader (lilo or loadlin) about how to pass options to the 1390 kernel at boot time.) 1391 1392 If unsure, say "off". 1393 1394config HIGHMEM4G 1395 bool "4GB" 1396 ---help--- 1397 Select this if you have a 32-bit processor and between 1 and 4 1398 gigabytes of physical RAM. 1399 1400config HIGHMEM64G 1401 bool "64GB" 1402 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1403 select X86_PAE 1404 ---help--- 1405 Select this if you have a 32-bit processor and more than 4 1406 gigabytes of physical RAM. 1407 1408endchoice 1409 1410choice 1411 prompt "Memory split" if EXPERT 1412 default VMSPLIT_3G 1413 depends on X86_32 1414 ---help--- 1415 Select the desired split between kernel and user memory. 1416 1417 If the address range available to the kernel is less than the 1418 physical memory installed, the remaining memory will be available 1419 as "high memory". Accessing high memory is a little more costly 1420 than low memory, as it needs to be mapped into the kernel first. 1421 Note that increasing the kernel address space limits the range 1422 available to user programs, making the address space there 1423 tighter. Selecting anything other than the default 3G/1G split 1424 will also likely make your kernel incompatible with binary-only 1425 kernel modules. 1426 1427 If you are not absolutely sure what you are doing, leave this 1428 option alone! 1429 1430 config VMSPLIT_3G 1431 bool "3G/1G user/kernel split" 1432 config VMSPLIT_3G_OPT 1433 depends on !X86_PAE 1434 bool "3G/1G user/kernel split (for full 1G low memory)" 1435 config VMSPLIT_2G 1436 bool "2G/2G user/kernel split" 1437 config VMSPLIT_2G_OPT 1438 depends on !X86_PAE 1439 bool "2G/2G user/kernel split (for full 2G low memory)" 1440 config VMSPLIT_1G 1441 bool "1G/3G user/kernel split" 1442endchoice 1443 1444config PAGE_OFFSET 1445 hex 1446 default 0xB0000000 if VMSPLIT_3G_OPT 1447 default 0x80000000 if VMSPLIT_2G 1448 default 0x78000000 if VMSPLIT_2G_OPT 1449 default 0x40000000 if VMSPLIT_1G 1450 default 0xC0000000 1451 depends on X86_32 1452 1453config HIGHMEM 1454 def_bool y 1455 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1456 1457config X86_PAE 1458 bool "PAE (Physical Address Extension) Support" 1459 depends on X86_32 && !HIGHMEM4G 1460 select PHYS_ADDR_T_64BIT 1461 select SWIOTLB 1462 ---help--- 1463 PAE is required for NX support, and furthermore enables 1464 larger swapspace support for non-overcommit purposes. It 1465 has the cost of more pagetable lookup overhead, and also 1466 consumes more pagetable space per process. 1467 1468config X86_5LEVEL 1469 bool "Enable 5-level page tables support" 1470 select DYNAMIC_MEMORY_LAYOUT 1471 select SPARSEMEM_VMEMMAP 1472 depends on X86_64 1473 ---help--- 1474 5-level paging enables access to larger address space: 1475 upto 128 PiB of virtual address space and 4 PiB of 1476 physical address space. 1477 1478 It will be supported by future Intel CPUs. 1479 1480 A kernel with the option enabled can be booted on machines that 1481 support 4- or 5-level paging. 1482 1483 See Documentation/x86/x86_64/5level-paging.txt for more 1484 information. 1485 1486 Say N if unsure. 1487 1488config X86_DIRECT_GBPAGES 1489 def_bool y 1490 depends on X86_64 && !DEBUG_PAGEALLOC 1491 ---help--- 1492 Certain kernel features effectively disable kernel 1493 linear 1 GB mappings (even if the CPU otherwise 1494 supports them), so don't confuse the user by printing 1495 that we have them enabled. 1496 1497config X86_CPA_STATISTICS 1498 bool "Enable statistic for Change Page Attribute" 1499 depends on DEBUG_FS 1500 ---help--- 1501 Expose statistics about the Change Page Attribute mechanims, which 1502 helps to determine the effectivness of preserving large and huge 1503 page mappings when mapping protections are changed. 1504 1505config ARCH_HAS_MEM_ENCRYPT 1506 def_bool y 1507 1508config AMD_MEM_ENCRYPT 1509 bool "AMD Secure Memory Encryption (SME) support" 1510 depends on X86_64 && CPU_SUP_AMD 1511 select DYNAMIC_PHYSICAL_MASK 1512 ---help--- 1513 Say yes to enable support for the encryption of system memory. 1514 This requires an AMD processor that supports Secure Memory 1515 Encryption (SME). 1516 1517config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1518 bool "Activate AMD Secure Memory Encryption (SME) by default" 1519 default y 1520 depends on AMD_MEM_ENCRYPT 1521 ---help--- 1522 Say yes to have system memory encrypted by default if running on 1523 an AMD processor that supports Secure Memory Encryption (SME). 1524 1525 If set to Y, then the encryption of system memory can be 1526 deactivated with the mem_encrypt=off command line option. 1527 1528 If set to N, then the encryption of system memory can be 1529 activated with the mem_encrypt=on command line option. 1530 1531config ARCH_USE_MEMREMAP_PROT 1532 def_bool y 1533 depends on AMD_MEM_ENCRYPT 1534 1535# Common NUMA Features 1536config NUMA 1537 bool "Numa Memory Allocation and Scheduler Support" 1538 depends on SMP 1539 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1540 default y if X86_BIGSMP 1541 ---help--- 1542 Enable NUMA (Non Uniform Memory Access) support. 1543 1544 The kernel will try to allocate memory used by a CPU on the 1545 local memory controller of the CPU and add some more 1546 NUMA awareness to the kernel. 1547 1548 For 64-bit this is recommended if the system is Intel Core i7 1549 (or later), AMD Opteron, or EM64T NUMA. 1550 1551 For 32-bit this is only needed if you boot a 32-bit 1552 kernel on a 64-bit NUMA platform. 1553 1554 Otherwise, you should say N. 1555 1556config AMD_NUMA 1557 def_bool y 1558 prompt "Old style AMD Opteron NUMA detection" 1559 depends on X86_64 && NUMA && PCI 1560 ---help--- 1561 Enable AMD NUMA node topology detection. You should say Y here if 1562 you have a multi processor AMD system. This uses an old method to 1563 read the NUMA configuration directly from the builtin Northbridge 1564 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1565 which also takes priority if both are compiled in. 1566 1567config X86_64_ACPI_NUMA 1568 def_bool y 1569 prompt "ACPI NUMA detection" 1570 depends on X86_64 && NUMA && ACPI && PCI 1571 select ACPI_NUMA 1572 ---help--- 1573 Enable ACPI SRAT based node topology detection. 1574 1575# Some NUMA nodes have memory ranges that span 1576# other nodes. Even though a pfn is valid and 1577# between a node's start and end pfns, it may not 1578# reside on that node. See memmap_init_zone() 1579# for details. 1580config NODES_SPAN_OTHER_NODES 1581 def_bool y 1582 depends on X86_64_ACPI_NUMA 1583 1584config NUMA_EMU 1585 bool "NUMA emulation" 1586 depends on NUMA 1587 ---help--- 1588 Enable NUMA emulation. A flat machine will be split 1589 into virtual nodes when booted with "numa=fake=N", where N is the 1590 number of nodes. This is only useful for debugging. 1591 1592config NODES_SHIFT 1593 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1594 range 1 10 1595 default "10" if MAXSMP 1596 default "6" if X86_64 1597 default "3" 1598 depends on NEED_MULTIPLE_NODES 1599 ---help--- 1600 Specify the maximum number of NUMA Nodes available on the target 1601 system. Increases memory reserved to accommodate various tables. 1602 1603config ARCH_HAVE_MEMORY_PRESENT 1604 def_bool y 1605 depends on X86_32 && DISCONTIGMEM 1606 1607config ARCH_FLATMEM_ENABLE 1608 def_bool y 1609 depends on X86_32 && !NUMA 1610 1611config ARCH_DISCONTIGMEM_ENABLE 1612 def_bool y 1613 depends on NUMA && X86_32 1614 1615config ARCH_DISCONTIGMEM_DEFAULT 1616 def_bool y 1617 depends on NUMA && X86_32 1618 1619config ARCH_SPARSEMEM_ENABLE 1620 def_bool y 1621 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1622 select SPARSEMEM_STATIC if X86_32 1623 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1624 1625config ARCH_SPARSEMEM_DEFAULT 1626 def_bool y 1627 depends on X86_64 1628 1629config ARCH_SELECT_MEMORY_MODEL 1630 def_bool y 1631 depends on ARCH_SPARSEMEM_ENABLE 1632 1633config ARCH_MEMORY_PROBE 1634 bool "Enable sysfs memory/probe interface" 1635 depends on X86_64 && MEMORY_HOTPLUG 1636 help 1637 This option enables a sysfs memory/probe interface for testing. 1638 See Documentation/memory-hotplug.txt for more information. 1639 If you are unsure how to answer this question, answer N. 1640 1641config ARCH_PROC_KCORE_TEXT 1642 def_bool y 1643 depends on X86_64 && PROC_KCORE 1644 1645config ILLEGAL_POINTER_VALUE 1646 hex 1647 default 0 if X86_32 1648 default 0xdead000000000000 if X86_64 1649 1650config X86_PMEM_LEGACY_DEVICE 1651 bool 1652 1653config X86_PMEM_LEGACY 1654 tristate "Support non-standard NVDIMMs and ADR protected memory" 1655 depends on PHYS_ADDR_T_64BIT 1656 depends on BLK_DEV 1657 select X86_PMEM_LEGACY_DEVICE 1658 select LIBNVDIMM 1659 help 1660 Treat memory marked using the non-standard e820 type of 12 as used 1661 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1662 The kernel will offer these regions to the 'pmem' driver so 1663 they can be used for persistent storage. 1664 1665 Say Y if unsure. 1666 1667config HIGHPTE 1668 bool "Allocate 3rd-level pagetables from highmem" 1669 depends on HIGHMEM 1670 ---help--- 1671 The VM uses one page table entry for each page of physical memory. 1672 For systems with a lot of RAM, this can be wasteful of precious 1673 low memory. Setting this option will put user-space page table 1674 entries in high memory. 1675 1676config X86_CHECK_BIOS_CORRUPTION 1677 bool "Check for low memory corruption" 1678 ---help--- 1679 Periodically check for memory corruption in low memory, which 1680 is suspected to be caused by BIOS. Even when enabled in the 1681 configuration, it is disabled at runtime. Enable it by 1682 setting "memory_corruption_check=1" on the kernel command 1683 line. By default it scans the low 64k of memory every 60 1684 seconds; see the memory_corruption_check_size and 1685 memory_corruption_check_period parameters in 1686 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1687 1688 When enabled with the default parameters, this option has 1689 almost no overhead, as it reserves a relatively small amount 1690 of memory and scans it infrequently. It both detects corruption 1691 and prevents it from affecting the running system. 1692 1693 It is, however, intended as a diagnostic tool; if repeatable 1694 BIOS-originated corruption always affects the same memory, 1695 you can use memmap= to prevent the kernel from using that 1696 memory. 1697 1698config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1699 bool "Set the default setting of memory_corruption_check" 1700 depends on X86_CHECK_BIOS_CORRUPTION 1701 default y 1702 ---help--- 1703 Set whether the default state of memory_corruption_check is 1704 on or off. 1705 1706config X86_RESERVE_LOW 1707 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1708 default 64 1709 range 4 640 1710 ---help--- 1711 Specify the amount of low memory to reserve for the BIOS. 1712 1713 The first page contains BIOS data structures that the kernel 1714 must not use, so that page must always be reserved. 1715 1716 By default we reserve the first 64K of physical RAM, as a 1717 number of BIOSes are known to corrupt that memory range 1718 during events such as suspend/resume or monitor cable 1719 insertion, so it must not be used by the kernel. 1720 1721 You can set this to 4 if you are absolutely sure that you 1722 trust the BIOS to get all its memory reservations and usages 1723 right. If you know your BIOS have problems beyond the 1724 default 64K area, you can set this to 640 to avoid using the 1725 entire low memory range. 1726 1727 If you have doubts about the BIOS (e.g. suspend/resume does 1728 not work or there's kernel crashes after certain hardware 1729 hotplug events) then you might want to enable 1730 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1731 typical corruption patterns. 1732 1733 Leave this to the default value of 64 if you are unsure. 1734 1735config MATH_EMULATION 1736 bool 1737 depends on MODIFY_LDT_SYSCALL 1738 prompt "Math emulation" if X86_32 1739 ---help--- 1740 Linux can emulate a math coprocessor (used for floating point 1741 operations) if you don't have one. 486DX and Pentium processors have 1742 a math coprocessor built in, 486SX and 386 do not, unless you added 1743 a 487DX or 387, respectively. (The messages during boot time can 1744 give you some hints here ["man dmesg"].) Everyone needs either a 1745 coprocessor or this emulation. 1746 1747 If you don't have a math coprocessor, you need to say Y here; if you 1748 say Y here even though you have a coprocessor, the coprocessor will 1749 be used nevertheless. (This behavior can be changed with the kernel 1750 command line option "no387", which comes handy if your coprocessor 1751 is broken. Try "man bootparam" or see the documentation of your boot 1752 loader (lilo or loadlin) about how to pass options to the kernel at 1753 boot time.) This means that it is a good idea to say Y here if you 1754 intend to use this kernel on different machines. 1755 1756 More information about the internals of the Linux math coprocessor 1757 emulation can be found in <file:arch/x86/math-emu/README>. 1758 1759 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1760 kernel, it won't hurt. 1761 1762config MTRR 1763 def_bool y 1764 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1765 ---help--- 1766 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1767 the Memory Type Range Registers (MTRRs) may be used to control 1768 processor access to memory ranges. This is most useful if you have 1769 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1770 allows bus write transfers to be combined into a larger transfer 1771 before bursting over the PCI/AGP bus. This can increase performance 1772 of image write operations 2.5 times or more. Saying Y here creates a 1773 /proc/mtrr file which may be used to manipulate your processor's 1774 MTRRs. Typically the X server should use this. 1775 1776 This code has a reasonably generic interface so that similar 1777 control registers on other processors can be easily supported 1778 as well: 1779 1780 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1781 Registers (ARRs) which provide a similar functionality to MTRRs. For 1782 these, the ARRs are used to emulate the MTRRs. 1783 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1784 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1785 write-combining. All of these processors are supported by this code 1786 and it makes sense to say Y here if you have one of them. 1787 1788 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1789 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1790 can lead to all sorts of problems, so it's good to say Y here. 1791 1792 You can safely say Y even if your machine doesn't have MTRRs, you'll 1793 just add about 9 KB to your kernel. 1794 1795 See <file:Documentation/x86/mtrr.txt> for more information. 1796 1797config MTRR_SANITIZER 1798 def_bool y 1799 prompt "MTRR cleanup support" 1800 depends on MTRR 1801 ---help--- 1802 Convert MTRR layout from continuous to discrete, so X drivers can 1803 add writeback entries. 1804 1805 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1806 The largest mtrr entry size for a continuous block can be set with 1807 mtrr_chunk_size. 1808 1809 If unsure, say Y. 1810 1811config MTRR_SANITIZER_ENABLE_DEFAULT 1812 int "MTRR cleanup enable value (0-1)" 1813 range 0 1 1814 default "0" 1815 depends on MTRR_SANITIZER 1816 ---help--- 1817 Enable mtrr cleanup default value 1818 1819config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1820 int "MTRR cleanup spare reg num (0-7)" 1821 range 0 7 1822 default "1" 1823 depends on MTRR_SANITIZER 1824 ---help--- 1825 mtrr cleanup spare entries default, it can be changed via 1826 mtrr_spare_reg_nr=N on the kernel command line. 1827 1828config X86_PAT 1829 def_bool y 1830 prompt "x86 PAT support" if EXPERT 1831 depends on MTRR 1832 ---help--- 1833 Use PAT attributes to setup page level cache control. 1834 1835 PATs are the modern equivalents of MTRRs and are much more 1836 flexible than MTRRs. 1837 1838 Say N here if you see bootup problems (boot crash, boot hang, 1839 spontaneous reboots) or a non-working video driver. 1840 1841 If unsure, say Y. 1842 1843config ARCH_USES_PG_UNCACHED 1844 def_bool y 1845 depends on X86_PAT 1846 1847config ARCH_RANDOM 1848 def_bool y 1849 prompt "x86 architectural random number generator" if EXPERT 1850 ---help--- 1851 Enable the x86 architectural RDRAND instruction 1852 (Intel Bull Mountain technology) to generate random numbers. 1853 If supported, this is a high bandwidth, cryptographically 1854 secure hardware random number generator. 1855 1856config X86_SMAP 1857 def_bool y 1858 prompt "Supervisor Mode Access Prevention" if EXPERT 1859 ---help--- 1860 Supervisor Mode Access Prevention (SMAP) is a security 1861 feature in newer Intel processors. There is a small 1862 performance cost if this enabled and turned on; there is 1863 also a small increase in the kernel size if this is enabled. 1864 1865 If unsure, say Y. 1866 1867config X86_INTEL_UMIP 1868 def_bool y 1869 depends on CPU_SUP_INTEL 1870 prompt "Intel User Mode Instruction Prevention" if EXPERT 1871 ---help--- 1872 The User Mode Instruction Prevention (UMIP) is a security 1873 feature in newer Intel processors. If enabled, a general 1874 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1875 or STR instructions are executed in user mode. These instructions 1876 unnecessarily expose information about the hardware state. 1877 1878 The vast majority of applications do not use these instructions. 1879 For the very few that do, software emulation is provided in 1880 specific cases in protected and virtual-8086 modes. Emulated 1881 results are dummy. 1882 1883config X86_INTEL_MPX 1884 prompt "Intel MPX (Memory Protection Extensions)" 1885 def_bool n 1886 # Note: only available in 64-bit mode due to VMA flags shortage 1887 depends on CPU_SUP_INTEL && X86_64 1888 select ARCH_USES_HIGH_VMA_FLAGS 1889 ---help--- 1890 MPX provides hardware features that can be used in 1891 conjunction with compiler-instrumented code to check 1892 memory references. It is designed to detect buffer 1893 overflow or underflow bugs. 1894 1895 This option enables running applications which are 1896 instrumented or otherwise use MPX. It does not use MPX 1897 itself inside the kernel or to protect the kernel 1898 against bad memory references. 1899 1900 Enabling this option will make the kernel larger: 1901 ~8k of kernel text and 36 bytes of data on a 64-bit 1902 defconfig. It adds a long to the 'mm_struct' which 1903 will increase the kernel memory overhead of each 1904 process and adds some branches to paths used during 1905 exec() and munmap(). 1906 1907 For details, see Documentation/x86/intel_mpx.txt 1908 1909 If unsure, say N. 1910 1911config X86_INTEL_MEMORY_PROTECTION_KEYS 1912 prompt "Intel Memory Protection Keys" 1913 def_bool y 1914 # Note: only available in 64-bit mode 1915 depends on CPU_SUP_INTEL && X86_64 1916 select ARCH_USES_HIGH_VMA_FLAGS 1917 select ARCH_HAS_PKEYS 1918 ---help--- 1919 Memory Protection Keys provides a mechanism for enforcing 1920 page-based protections, but without requiring modification of the 1921 page tables when an application changes protection domains. 1922 1923 For details, see Documentation/x86/protection-keys.txt 1924 1925 If unsure, say y. 1926 1927config EFI 1928 bool "EFI runtime service support" 1929 depends on ACPI 1930 select UCS2_STRING 1931 select EFI_RUNTIME_WRAPPERS 1932 ---help--- 1933 This enables the kernel to use EFI runtime services that are 1934 available (such as the EFI variable services). 1935 1936 This option is only useful on systems that have EFI firmware. 1937 In addition, you should use the latest ELILO loader available 1938 at <http://elilo.sourceforge.net> in order to take advantage 1939 of EFI runtime services. However, even with this option, the 1940 resultant kernel should continue to boot on existing non-EFI 1941 platforms. 1942 1943config EFI_STUB 1944 bool "EFI stub support" 1945 depends on EFI && !X86_USE_3DNOW 1946 select RELOCATABLE 1947 ---help--- 1948 This kernel feature allows a bzImage to be loaded directly 1949 by EFI firmware without the use of a bootloader. 1950 1951 See Documentation/efi-stub.txt for more information. 1952 1953config EFI_MIXED 1954 bool "EFI mixed-mode support" 1955 depends on EFI_STUB && X86_64 1956 ---help--- 1957 Enabling this feature allows a 64-bit kernel to be booted 1958 on a 32-bit firmware, provided that your CPU supports 64-bit 1959 mode. 1960 1961 Note that it is not possible to boot a mixed-mode enabled 1962 kernel via the EFI boot stub - a bootloader that supports 1963 the EFI handover protocol must be used. 1964 1965 If unsure, say N. 1966 1967config SECCOMP 1968 def_bool y 1969 prompt "Enable seccomp to safely compute untrusted bytecode" 1970 ---help--- 1971 This kernel feature is useful for number crunching applications 1972 that may need to compute untrusted bytecode during their 1973 execution. By using pipes or other transports made available to 1974 the process as file descriptors supporting the read/write 1975 syscalls, it's possible to isolate those applications in 1976 their own address space using seccomp. Once seccomp is 1977 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1978 and the task is only allowed to execute a few safe syscalls 1979 defined by each seccomp mode. 1980 1981 If unsure, say Y. Only embedded should say N here. 1982 1983source "kernel/Kconfig.hz" 1984 1985config KEXEC 1986 bool "kexec system call" 1987 select KEXEC_CORE 1988 ---help--- 1989 kexec is a system call that implements the ability to shutdown your 1990 current kernel, and to start another kernel. It is like a reboot 1991 but it is independent of the system firmware. And like a reboot 1992 you can start any kernel with it, not just Linux. 1993 1994 The name comes from the similarity to the exec system call. 1995 1996 It is an ongoing process to be certain the hardware in a machine 1997 is properly shutdown, so do not be surprised if this code does not 1998 initially work for you. As of this writing the exact hardware 1999 interface is strongly in flux, so no good recommendation can be 2000 made. 2001 2002config KEXEC_FILE 2003 bool "kexec file based system call" 2004 select KEXEC_CORE 2005 select BUILD_BIN2C 2006 depends on X86_64 2007 depends on CRYPTO=y 2008 depends on CRYPTO_SHA256=y 2009 ---help--- 2010 This is new version of kexec system call. This system call is 2011 file based and takes file descriptors as system call argument 2012 for kernel and initramfs as opposed to list of segments as 2013 accepted by previous system call. 2014 2015config ARCH_HAS_KEXEC_PURGATORY 2016 def_bool KEXEC_FILE 2017 2018config KEXEC_VERIFY_SIG 2019 bool "Verify kernel signature during kexec_file_load() syscall" 2020 depends on KEXEC_FILE 2021 ---help--- 2022 This option makes kernel signature verification mandatory for 2023 the kexec_file_load() syscall. 2024 2025 In addition to that option, you need to enable signature 2026 verification for the corresponding kernel image type being 2027 loaded in order for this to work. 2028 2029config KEXEC_BZIMAGE_VERIFY_SIG 2030 bool "Enable bzImage signature verification support" 2031 depends on KEXEC_VERIFY_SIG 2032 depends on SIGNED_PE_FILE_VERIFICATION 2033 select SYSTEM_TRUSTED_KEYRING 2034 ---help--- 2035 Enable bzImage signature verification support. 2036 2037config CRASH_DUMP 2038 bool "kernel crash dumps" 2039 depends on X86_64 || (X86_32 && HIGHMEM) 2040 ---help--- 2041 Generate crash dump after being started by kexec. 2042 This should be normally only set in special crash dump kernels 2043 which are loaded in the main kernel with kexec-tools into 2044 a specially reserved region and then later executed after 2045 a crash by kdump/kexec. The crash dump kernel must be compiled 2046 to a memory address not used by the main kernel or BIOS using 2047 PHYSICAL_START, or it must be built as a relocatable image 2048 (CONFIG_RELOCATABLE=y). 2049 For more details see Documentation/kdump/kdump.txt 2050 2051config KEXEC_JUMP 2052 bool "kexec jump" 2053 depends on KEXEC && HIBERNATION 2054 ---help--- 2055 Jump between original kernel and kexeced kernel and invoke 2056 code in physical address mode via KEXEC 2057 2058config PHYSICAL_START 2059 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2060 default "0x1000000" 2061 ---help--- 2062 This gives the physical address where the kernel is loaded. 2063 2064 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2065 bzImage will decompress itself to above physical address and 2066 run from there. Otherwise, bzImage will run from the address where 2067 it has been loaded by the boot loader and will ignore above physical 2068 address. 2069 2070 In normal kdump cases one does not have to set/change this option 2071 as now bzImage can be compiled as a completely relocatable image 2072 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2073 address. This option is mainly useful for the folks who don't want 2074 to use a bzImage for capturing the crash dump and want to use a 2075 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2076 to be specifically compiled to run from a specific memory area 2077 (normally a reserved region) and this option comes handy. 2078 2079 So if you are using bzImage for capturing the crash dump, 2080 leave the value here unchanged to 0x1000000 and set 2081 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2082 for capturing the crash dump change this value to start of 2083 the reserved region. In other words, it can be set based on 2084 the "X" value as specified in the "crashkernel=YM@XM" 2085 command line boot parameter passed to the panic-ed 2086 kernel. Please take a look at Documentation/kdump/kdump.txt 2087 for more details about crash dumps. 2088 2089 Usage of bzImage for capturing the crash dump is recommended as 2090 one does not have to build two kernels. Same kernel can be used 2091 as production kernel and capture kernel. Above option should have 2092 gone away after relocatable bzImage support is introduced. But it 2093 is present because there are users out there who continue to use 2094 vmlinux for dump capture. This option should go away down the 2095 line. 2096 2097 Don't change this unless you know what you are doing. 2098 2099config RELOCATABLE 2100 bool "Build a relocatable kernel" 2101 default y 2102 ---help--- 2103 This builds a kernel image that retains relocation information 2104 so it can be loaded someplace besides the default 1MB. 2105 The relocations tend to make the kernel binary about 10% larger, 2106 but are discarded at runtime. 2107 2108 One use is for the kexec on panic case where the recovery kernel 2109 must live at a different physical address than the primary 2110 kernel. 2111 2112 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2113 it has been loaded at and the compile time physical address 2114 (CONFIG_PHYSICAL_START) is used as the minimum location. 2115 2116config RANDOMIZE_BASE 2117 bool "Randomize the address of the kernel image (KASLR)" 2118 depends on RELOCATABLE 2119 default y 2120 ---help--- 2121 In support of Kernel Address Space Layout Randomization (KASLR), 2122 this randomizes the physical address at which the kernel image 2123 is decompressed and the virtual address where the kernel 2124 image is mapped, as a security feature that deters exploit 2125 attempts relying on knowledge of the location of kernel 2126 code internals. 2127 2128 On 64-bit, the kernel physical and virtual addresses are 2129 randomized separately. The physical address will be anywhere 2130 between 16MB and the top of physical memory (up to 64TB). The 2131 virtual address will be randomized from 16MB up to 1GB (9 bits 2132 of entropy). Note that this also reduces the memory space 2133 available to kernel modules from 1.5GB to 1GB. 2134 2135 On 32-bit, the kernel physical and virtual addresses are 2136 randomized together. They will be randomized from 16MB up to 2137 512MB (8 bits of entropy). 2138 2139 Entropy is generated using the RDRAND instruction if it is 2140 supported. If RDTSC is supported, its value is mixed into 2141 the entropy pool as well. If neither RDRAND nor RDTSC are 2142 supported, then entropy is read from the i8254 timer. The 2143 usable entropy is limited by the kernel being built using 2144 2GB addressing, and that PHYSICAL_ALIGN must be at a 2145 minimum of 2MB. As a result, only 10 bits of entropy are 2146 theoretically possible, but the implementations are further 2147 limited due to memory layouts. 2148 2149 If unsure, say Y. 2150 2151# Relocation on x86 needs some additional build support 2152config X86_NEED_RELOCS 2153 def_bool y 2154 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2155 2156config PHYSICAL_ALIGN 2157 hex "Alignment value to which kernel should be aligned" 2158 default "0x200000" 2159 range 0x2000 0x1000000 if X86_32 2160 range 0x200000 0x1000000 if X86_64 2161 ---help--- 2162 This value puts the alignment restrictions on physical address 2163 where kernel is loaded and run from. Kernel is compiled for an 2164 address which meets above alignment restriction. 2165 2166 If bootloader loads the kernel at a non-aligned address and 2167 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2168 address aligned to above value and run from there. 2169 2170 If bootloader loads the kernel at a non-aligned address and 2171 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2172 load address and decompress itself to the address it has been 2173 compiled for and run from there. The address for which kernel is 2174 compiled already meets above alignment restrictions. Hence the 2175 end result is that kernel runs from a physical address meeting 2176 above alignment restrictions. 2177 2178 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2179 this value must be a multiple of 0x200000. 2180 2181 Don't change this unless you know what you are doing. 2182 2183config DYNAMIC_MEMORY_LAYOUT 2184 bool 2185 ---help--- 2186 This option makes base addresses of vmalloc and vmemmap as well as 2187 __PAGE_OFFSET movable during boot. 2188 2189config RANDOMIZE_MEMORY 2190 bool "Randomize the kernel memory sections" 2191 depends on X86_64 2192 depends on RANDOMIZE_BASE 2193 select DYNAMIC_MEMORY_LAYOUT 2194 default RANDOMIZE_BASE 2195 ---help--- 2196 Randomizes the base virtual address of kernel memory sections 2197 (physical memory mapping, vmalloc & vmemmap). This security feature 2198 makes exploits relying on predictable memory locations less reliable. 2199 2200 The order of allocations remains unchanged. Entropy is generated in 2201 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2202 configuration have in average 30,000 different possible virtual 2203 addresses for each memory section. 2204 2205 If unsure, say Y. 2206 2207config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2208 hex "Physical memory mapping padding" if EXPERT 2209 depends on RANDOMIZE_MEMORY 2210 default "0xa" if MEMORY_HOTPLUG 2211 default "0x0" 2212 range 0x1 0x40 if MEMORY_HOTPLUG 2213 range 0x0 0x40 2214 ---help--- 2215 Define the padding in terabytes added to the existing physical 2216 memory size during kernel memory randomization. It is useful 2217 for memory hotplug support but reduces the entropy available for 2218 address randomization. 2219 2220 If unsure, leave at the default value. 2221 2222config HOTPLUG_CPU 2223 bool "Support for hot-pluggable CPUs" 2224 depends on SMP 2225 ---help--- 2226 Say Y here to allow turning CPUs off and on. CPUs can be 2227 controlled through /sys/devices/system/cpu. 2228 ( Note: power management support will enable this option 2229 automatically on SMP systems. ) 2230 Say N if you want to disable CPU hotplug. 2231 2232config BOOTPARAM_HOTPLUG_CPU0 2233 bool "Set default setting of cpu0_hotpluggable" 2234 depends on HOTPLUG_CPU 2235 ---help--- 2236 Set whether default state of cpu0_hotpluggable is on or off. 2237 2238 Say Y here to enable CPU0 hotplug by default. If this switch 2239 is turned on, there is no need to give cpu0_hotplug kernel 2240 parameter and the CPU0 hotplug feature is enabled by default. 2241 2242 Please note: there are two known CPU0 dependencies if you want 2243 to enable the CPU0 hotplug feature either by this switch or by 2244 cpu0_hotplug kernel parameter. 2245 2246 First, resume from hibernate or suspend always starts from CPU0. 2247 So hibernate and suspend are prevented if CPU0 is offline. 2248 2249 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2250 offline if any interrupt can not migrate out of CPU0. There may 2251 be other CPU0 dependencies. 2252 2253 Please make sure the dependencies are under your control before 2254 you enable this feature. 2255 2256 Say N if you don't want to enable CPU0 hotplug feature by default. 2257 You still can enable the CPU0 hotplug feature at boot by kernel 2258 parameter cpu0_hotplug. 2259 2260config DEBUG_HOTPLUG_CPU0 2261 def_bool n 2262 prompt "Debug CPU0 hotplug" 2263 depends on HOTPLUG_CPU 2264 ---help--- 2265 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2266 soon as possible and boots up userspace with CPU0 offlined. User 2267 can online CPU0 back after boot time. 2268 2269 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2270 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2271 compilation or giving cpu0_hotplug kernel parameter at boot. 2272 2273 If unsure, say N. 2274 2275config COMPAT_VDSO 2276 def_bool n 2277 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2278 depends on COMPAT_32 2279 ---help--- 2280 Certain buggy versions of glibc will crash if they are 2281 presented with a 32-bit vDSO that is not mapped at the address 2282 indicated in its segment table. 2283 2284 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2285 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2286 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2287 the only released version with the bug, but OpenSUSE 9 2288 contains a buggy "glibc 2.3.2". 2289 2290 The symptom of the bug is that everything crashes on startup, saying: 2291 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2292 2293 Saying Y here changes the default value of the vdso32 boot 2294 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2295 This works around the glibc bug but hurts performance. 2296 2297 If unsure, say N: if you are compiling your own kernel, you 2298 are unlikely to be using a buggy version of glibc. 2299 2300choice 2301 prompt "vsyscall table for legacy applications" 2302 depends on X86_64 2303 default LEGACY_VSYSCALL_EMULATE 2304 help 2305 Legacy user code that does not know how to find the vDSO expects 2306 to be able to issue three syscalls by calling fixed addresses in 2307 kernel space. Since this location is not randomized with ASLR, 2308 it can be used to assist security vulnerability exploitation. 2309 2310 This setting can be changed at boot time via the kernel command 2311 line parameter vsyscall=[emulate|none]. 2312 2313 On a system with recent enough glibc (2.14 or newer) and no 2314 static binaries, you can say None without a performance penalty 2315 to improve security. 2316 2317 If unsure, select "Emulate". 2318 2319 config LEGACY_VSYSCALL_EMULATE 2320 bool "Emulate" 2321 help 2322 The kernel traps and emulates calls into the fixed 2323 vsyscall address mapping. This makes the mapping 2324 non-executable, but it still contains known contents, 2325 which could be used in certain rare security vulnerability 2326 exploits. This configuration is recommended when userspace 2327 still uses the vsyscall area. 2328 2329 config LEGACY_VSYSCALL_NONE 2330 bool "None" 2331 help 2332 There will be no vsyscall mapping at all. This will 2333 eliminate any risk of ASLR bypass due to the vsyscall 2334 fixed address mapping. Attempts to use the vsyscalls 2335 will be reported to dmesg, so that either old or 2336 malicious userspace programs can be identified. 2337 2338endchoice 2339 2340config CMDLINE_BOOL 2341 bool "Built-in kernel command line" 2342 ---help--- 2343 Allow for specifying boot arguments to the kernel at 2344 build time. On some systems (e.g. embedded ones), it is 2345 necessary or convenient to provide some or all of the 2346 kernel boot arguments with the kernel itself (that is, 2347 to not rely on the boot loader to provide them.) 2348 2349 To compile command line arguments into the kernel, 2350 set this option to 'Y', then fill in the 2351 boot arguments in CONFIG_CMDLINE. 2352 2353 Systems with fully functional boot loaders (i.e. non-embedded) 2354 should leave this option set to 'N'. 2355 2356config CMDLINE 2357 string "Built-in kernel command string" 2358 depends on CMDLINE_BOOL 2359 default "" 2360 ---help--- 2361 Enter arguments here that should be compiled into the kernel 2362 image and used at boot time. If the boot loader provides a 2363 command line at boot time, it is appended to this string to 2364 form the full kernel command line, when the system boots. 2365 2366 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2367 change this behavior. 2368 2369 In most cases, the command line (whether built-in or provided 2370 by the boot loader) should specify the device for the root 2371 file system. 2372 2373config CMDLINE_OVERRIDE 2374 bool "Built-in command line overrides boot loader arguments" 2375 depends on CMDLINE_BOOL 2376 ---help--- 2377 Set this option to 'Y' to have the kernel ignore the boot loader 2378 command line, and use ONLY the built-in command line. 2379 2380 This is used to work around broken boot loaders. This should 2381 be set to 'N' under normal conditions. 2382 2383config MODIFY_LDT_SYSCALL 2384 bool "Enable the LDT (local descriptor table)" if EXPERT 2385 default y 2386 ---help--- 2387 Linux can allow user programs to install a per-process x86 2388 Local Descriptor Table (LDT) using the modify_ldt(2) system 2389 call. This is required to run 16-bit or segmented code such as 2390 DOSEMU or some Wine programs. It is also used by some very old 2391 threading libraries. 2392 2393 Enabling this feature adds a small amount of overhead to 2394 context switches and increases the low-level kernel attack 2395 surface. Disabling it removes the modify_ldt(2) system call. 2396 2397 Saying 'N' here may make sense for embedded or server kernels. 2398 2399source "kernel/livepatch/Kconfig" 2400 2401endmenu 2402 2403config ARCH_HAS_ADD_PAGES 2404 def_bool y 2405 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2406 2407config ARCH_ENABLE_MEMORY_HOTPLUG 2408 def_bool y 2409 depends on X86_64 || (X86_32 && HIGHMEM) 2410 2411config ARCH_ENABLE_MEMORY_HOTREMOVE 2412 def_bool y 2413 depends on MEMORY_HOTPLUG 2414 2415config USE_PERCPU_NUMA_NODE_ID 2416 def_bool y 2417 depends on NUMA 2418 2419config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2420 def_bool y 2421 depends on X86_64 || X86_PAE 2422 2423config ARCH_ENABLE_HUGEPAGE_MIGRATION 2424 def_bool y 2425 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2426 2427config ARCH_ENABLE_THP_MIGRATION 2428 def_bool y 2429 depends on X86_64 && TRANSPARENT_HUGEPAGE 2430 2431menu "Power management and ACPI options" 2432 2433config ARCH_HIBERNATION_HEADER 2434 def_bool y 2435 depends on HIBERNATION 2436 2437source "kernel/power/Kconfig" 2438 2439source "drivers/acpi/Kconfig" 2440 2441source "drivers/sfi/Kconfig" 2442 2443config X86_APM_BOOT 2444 def_bool y 2445 depends on APM 2446 2447menuconfig APM 2448 tristate "APM (Advanced Power Management) BIOS support" 2449 depends on X86_32 && PM_SLEEP 2450 ---help--- 2451 APM is a BIOS specification for saving power using several different 2452 techniques. This is mostly useful for battery powered laptops with 2453 APM compliant BIOSes. If you say Y here, the system time will be 2454 reset after a RESUME operation, the /proc/apm device will provide 2455 battery status information, and user-space programs will receive 2456 notification of APM "events" (e.g. battery status change). 2457 2458 If you select "Y" here, you can disable actual use of the APM 2459 BIOS by passing the "apm=off" option to the kernel at boot time. 2460 2461 Note that the APM support is almost completely disabled for 2462 machines with more than one CPU. 2463 2464 In order to use APM, you will need supporting software. For location 2465 and more information, read <file:Documentation/power/apm-acpi.txt> 2466 and the Battery Powered Linux mini-HOWTO, available from 2467 <http://www.tldp.org/docs.html#howto>. 2468 2469 This driver does not spin down disk drives (see the hdparm(8) 2470 manpage ("man 8 hdparm") for that), and it doesn't turn off 2471 VESA-compliant "green" monitors. 2472 2473 This driver does not support the TI 4000M TravelMate and the ACER 2474 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2475 desktop machines also don't have compliant BIOSes, and this driver 2476 may cause those machines to panic during the boot phase. 2477 2478 Generally, if you don't have a battery in your machine, there isn't 2479 much point in using this driver and you should say N. If you get 2480 random kernel OOPSes or reboots that don't seem to be related to 2481 anything, try disabling/enabling this option (or disabling/enabling 2482 APM in your BIOS). 2483 2484 Some other things you should try when experiencing seemingly random, 2485 "weird" problems: 2486 2487 1) make sure that you have enough swap space and that it is 2488 enabled. 2489 2) pass the "no-hlt" option to the kernel 2490 3) switch on floating point emulation in the kernel and pass 2491 the "no387" option to the kernel 2492 4) pass the "floppy=nodma" option to the kernel 2493 5) pass the "mem=4M" option to the kernel (thereby disabling 2494 all but the first 4 MB of RAM) 2495 6) make sure that the CPU is not over clocked. 2496 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2497 8) disable the cache from your BIOS settings 2498 9) install a fan for the video card or exchange video RAM 2499 10) install a better fan for the CPU 2500 11) exchange RAM chips 2501 12) exchange the motherboard. 2502 2503 To compile this driver as a module, choose M here: the 2504 module will be called apm. 2505 2506if APM 2507 2508config APM_IGNORE_USER_SUSPEND 2509 bool "Ignore USER SUSPEND" 2510 ---help--- 2511 This option will ignore USER SUSPEND requests. On machines with a 2512 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2513 series notebooks, it is necessary to say Y because of a BIOS bug. 2514 2515config APM_DO_ENABLE 2516 bool "Enable PM at boot time" 2517 ---help--- 2518 Enable APM features at boot time. From page 36 of the APM BIOS 2519 specification: "When disabled, the APM BIOS does not automatically 2520 power manage devices, enter the Standby State, enter the Suspend 2521 State, or take power saving steps in response to CPU Idle calls." 2522 This driver will make CPU Idle calls when Linux is idle (unless this 2523 feature is turned off -- see "Do CPU IDLE calls", below). This 2524 should always save battery power, but more complicated APM features 2525 will be dependent on your BIOS implementation. You may need to turn 2526 this option off if your computer hangs at boot time when using APM 2527 support, or if it beeps continuously instead of suspending. Turn 2528 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2529 T400CDT. This is off by default since most machines do fine without 2530 this feature. 2531 2532config APM_CPU_IDLE 2533 depends on CPU_IDLE 2534 bool "Make CPU Idle calls when idle" 2535 ---help--- 2536 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2537 On some machines, this can activate improved power savings, such as 2538 a slowed CPU clock rate, when the machine is idle. These idle calls 2539 are made after the idle loop has run for some length of time (e.g., 2540 333 mS). On some machines, this will cause a hang at boot time or 2541 whenever the CPU becomes idle. (On machines with more than one CPU, 2542 this option does nothing.) 2543 2544config APM_DISPLAY_BLANK 2545 bool "Enable console blanking using APM" 2546 ---help--- 2547 Enable console blanking using the APM. Some laptops can use this to 2548 turn off the LCD backlight when the screen blanker of the Linux 2549 virtual console blanks the screen. Note that this is only used by 2550 the virtual console screen blanker, and won't turn off the backlight 2551 when using the X Window system. This also doesn't have anything to 2552 do with your VESA-compliant power-saving monitor. Further, this 2553 option doesn't work for all laptops -- it might not turn off your 2554 backlight at all, or it might print a lot of errors to the console, 2555 especially if you are using gpm. 2556 2557config APM_ALLOW_INTS 2558 bool "Allow interrupts during APM BIOS calls" 2559 ---help--- 2560 Normally we disable external interrupts while we are making calls to 2561 the APM BIOS as a measure to lessen the effects of a badly behaving 2562 BIOS implementation. The BIOS should reenable interrupts if it 2563 needs to. Unfortunately, some BIOSes do not -- especially those in 2564 many of the newer IBM Thinkpads. If you experience hangs when you 2565 suspend, try setting this to Y. Otherwise, say N. 2566 2567endif # APM 2568 2569source "drivers/cpufreq/Kconfig" 2570 2571source "drivers/cpuidle/Kconfig" 2572 2573source "drivers/idle/Kconfig" 2574 2575endmenu 2576 2577 2578menu "Bus options (PCI etc.)" 2579 2580choice 2581 prompt "PCI access mode" 2582 depends on X86_32 && PCI 2583 default PCI_GOANY 2584 ---help--- 2585 On PCI systems, the BIOS can be used to detect the PCI devices and 2586 determine their configuration. However, some old PCI motherboards 2587 have BIOS bugs and may crash if this is done. Also, some embedded 2588 PCI-based systems don't have any BIOS at all. Linux can also try to 2589 detect the PCI hardware directly without using the BIOS. 2590 2591 With this option, you can specify how Linux should detect the 2592 PCI devices. If you choose "BIOS", the BIOS will be used, 2593 if you choose "Direct", the BIOS won't be used, and if you 2594 choose "MMConfig", then PCI Express MMCONFIG will be used. 2595 If you choose "Any", the kernel will try MMCONFIG, then the 2596 direct access method and falls back to the BIOS if that doesn't 2597 work. If unsure, go with the default, which is "Any". 2598 2599config PCI_GOBIOS 2600 bool "BIOS" 2601 2602config PCI_GOMMCONFIG 2603 bool "MMConfig" 2604 2605config PCI_GODIRECT 2606 bool "Direct" 2607 2608config PCI_GOOLPC 2609 bool "OLPC XO-1" 2610 depends on OLPC 2611 2612config PCI_GOANY 2613 bool "Any" 2614 2615endchoice 2616 2617config PCI_BIOS 2618 def_bool y 2619 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2620 2621# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2622config PCI_DIRECT 2623 def_bool y 2624 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2625 2626config PCI_MMCONFIG 2627 bool "Support mmconfig PCI config space access" if X86_64 2628 default y 2629 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2630 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2631 2632config PCI_OLPC 2633 def_bool y 2634 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2635 2636config PCI_XEN 2637 def_bool y 2638 depends on PCI && XEN 2639 select SWIOTLB_XEN 2640 2641config MMCONF_FAM10H 2642 def_bool y 2643 depends on X86_64 && PCI_MMCONFIG && ACPI 2644 2645config PCI_CNB20LE_QUIRK 2646 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2647 depends on PCI 2648 help 2649 Read the PCI windows out of the CNB20LE host bridge. This allows 2650 PCI hotplug to work on systems with the CNB20LE chipset which do 2651 not have ACPI. 2652 2653 There's no public spec for this chipset, and this functionality 2654 is known to be incomplete. 2655 2656 You should say N unless you know you need this. 2657 2658config ISA_BUS 2659 bool "ISA bus support on modern systems" if EXPERT 2660 help 2661 Expose ISA bus device drivers and options available for selection and 2662 configuration. Enable this option if your target machine has an ISA 2663 bus. ISA is an older system, displaced by PCI and newer bus 2664 architectures -- if your target machine is modern, it probably does 2665 not have an ISA bus. 2666 2667 If unsure, say N. 2668 2669# x86_64 have no ISA slots, but can have ISA-style DMA. 2670config ISA_DMA_API 2671 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2672 default y 2673 help 2674 Enables ISA-style DMA support for devices requiring such controllers. 2675 If unsure, say Y. 2676 2677if X86_32 2678 2679config ISA 2680 bool "ISA support" 2681 ---help--- 2682 Find out whether you have ISA slots on your motherboard. ISA is the 2683 name of a bus system, i.e. the way the CPU talks to the other stuff 2684 inside your box. Other bus systems are PCI, EISA, MicroChannel 2685 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2686 newer boards don't support it. If you have ISA, say Y, otherwise N. 2687 2688config SCx200 2689 tristate "NatSemi SCx200 support" 2690 ---help--- 2691 This provides basic support for National Semiconductor's 2692 (now AMD's) Geode processors. The driver probes for the 2693 PCI-IDs of several on-chip devices, so its a good dependency 2694 for other scx200_* drivers. 2695 2696 If compiled as a module, the driver is named scx200. 2697 2698config SCx200HR_TIMER 2699 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2700 depends on SCx200 2701 default y 2702 ---help--- 2703 This driver provides a clocksource built upon the on-chip 2704 27MHz high-resolution timer. Its also a workaround for 2705 NSC Geode SC-1100's buggy TSC, which loses time when the 2706 processor goes idle (as is done by the scheduler). The 2707 other workaround is idle=poll boot option. 2708 2709config OLPC 2710 bool "One Laptop Per Child support" 2711 depends on !X86_PAE 2712 select GPIOLIB 2713 select OF 2714 select OF_PROMTREE 2715 select IRQ_DOMAIN 2716 ---help--- 2717 Add support for detecting the unique features of the OLPC 2718 XO hardware. 2719 2720config OLPC_XO1_PM 2721 bool "OLPC XO-1 Power Management" 2722 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2723 ---help--- 2724 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2725 2726config OLPC_XO1_RTC 2727 bool "OLPC XO-1 Real Time Clock" 2728 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2729 ---help--- 2730 Add support for the XO-1 real time clock, which can be used as a 2731 programmable wakeup source. 2732 2733config OLPC_XO1_SCI 2734 bool "OLPC XO-1 SCI extras" 2735 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2736 depends on INPUT=y 2737 select POWER_SUPPLY 2738 ---help--- 2739 Add support for SCI-based features of the OLPC XO-1 laptop: 2740 - EC-driven system wakeups 2741 - Power button 2742 - Ebook switch 2743 - Lid switch 2744 - AC adapter status updates 2745 - Battery status updates 2746 2747config OLPC_XO15_SCI 2748 bool "OLPC XO-1.5 SCI extras" 2749 depends on OLPC && ACPI 2750 select POWER_SUPPLY 2751 ---help--- 2752 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2753 - EC-driven system wakeups 2754 - AC adapter status updates 2755 - Battery status updates 2756 2757config ALIX 2758 bool "PCEngines ALIX System Support (LED setup)" 2759 select GPIOLIB 2760 ---help--- 2761 This option enables system support for the PCEngines ALIX. 2762 At present this just sets up LEDs for GPIO control on 2763 ALIX2/3/6 boards. However, other system specific setup should 2764 get added here. 2765 2766 Note: You must still enable the drivers for GPIO and LED support 2767 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2768 2769 Note: You have to set alix.force=1 for boards with Award BIOS. 2770 2771config NET5501 2772 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2773 select GPIOLIB 2774 ---help--- 2775 This option enables system support for the Soekris Engineering net5501. 2776 2777config GEOS 2778 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2779 select GPIOLIB 2780 depends on DMI 2781 ---help--- 2782 This option enables system support for the Traverse Technologies GEOS. 2783 2784config TS5500 2785 bool "Technologic Systems TS-5500 platform support" 2786 depends on MELAN 2787 select CHECK_SIGNATURE 2788 select NEW_LEDS 2789 select LEDS_CLASS 2790 ---help--- 2791 This option enables system support for the Technologic Systems TS-5500. 2792 2793endif # X86_32 2794 2795config AMD_NB 2796 def_bool y 2797 depends on CPU_SUP_AMD && PCI 2798 2799config X86_SYSFB 2800 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2801 help 2802 Firmwares often provide initial graphics framebuffers so the BIOS, 2803 bootloader or kernel can show basic video-output during boot for 2804 user-guidance and debugging. Historically, x86 used the VESA BIOS 2805 Extensions and EFI-framebuffers for this, which are mostly limited 2806 to x86. 2807 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2808 framebuffers so the new generic system-framebuffer drivers can be 2809 used on x86. If the framebuffer is not compatible with the generic 2810 modes, it is advertised as fallback platform framebuffer so legacy 2811 drivers like efifb, vesafb and uvesafb can pick it up. 2812 If this option is not selected, all system framebuffers are always 2813 marked as fallback platform framebuffers as usual. 2814 2815 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2816 not be able to pick up generic system framebuffers if this option 2817 is selected. You are highly encouraged to enable simplefb as 2818 replacement if you select this option. simplefb can correctly deal 2819 with generic system framebuffers. But you should still keep vesafb 2820 and others enabled as fallback if a system framebuffer is 2821 incompatible with simplefb. 2822 2823 If unsure, say Y. 2824 2825endmenu 2826 2827 2828menu "Binary Emulations" 2829 2830config IA32_EMULATION 2831 bool "IA32 Emulation" 2832 depends on X86_64 2833 select ARCH_WANT_OLD_COMPAT_IPC 2834 select BINFMT_ELF 2835 select COMPAT_BINFMT_ELF 2836 select COMPAT_OLD_SIGACTION 2837 ---help--- 2838 Include code to run legacy 32-bit programs under a 2839 64-bit kernel. You should likely turn this on, unless you're 2840 100% sure that you don't have any 32-bit programs left. 2841 2842config IA32_AOUT 2843 tristate "IA32 a.out support" 2844 depends on IA32_EMULATION 2845 ---help--- 2846 Support old a.out binaries in the 32bit emulation. 2847 2848config X86_X32 2849 bool "x32 ABI for 64-bit mode" 2850 depends on X86_64 2851 ---help--- 2852 Include code to run binaries for the x32 native 32-bit ABI 2853 for 64-bit processors. An x32 process gets access to the 2854 full 64-bit register file and wide data path while leaving 2855 pointers at 32 bits for smaller memory footprint. 2856 2857 You will need a recent binutils (2.22 or later) with 2858 elf32_x86_64 support enabled to compile a kernel with this 2859 option set. 2860 2861config COMPAT_32 2862 def_bool y 2863 depends on IA32_EMULATION || X86_32 2864 select HAVE_UID16 2865 select OLD_SIGSUSPEND3 2866 2867config COMPAT 2868 def_bool y 2869 depends on IA32_EMULATION || X86_X32 2870 2871if COMPAT 2872config COMPAT_FOR_U64_ALIGNMENT 2873 def_bool y 2874 2875config SYSVIPC_COMPAT 2876 def_bool y 2877 depends on SYSVIPC 2878endif 2879 2880endmenu 2881 2882 2883config HAVE_ATOMIC_IOMAP 2884 def_bool y 2885 depends on X86_32 2886 2887config X86_DEV_DMA_OPS 2888 bool 2889 depends on X86_64 || STA2X11 2890 2891config X86_DMA_REMAP 2892 bool 2893 depends on STA2X11 2894 2895config HAVE_GENERIC_GUP 2896 def_bool y 2897 2898source "drivers/firmware/Kconfig" 2899 2900source "arch/x86/kvm/Kconfig" 2901