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_SG_CHAIN 70 select ARCH_HAS_STRICT_KERNEL_RWX 71 select ARCH_HAS_STRICT_MODULE_RWX 72 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 73 select ARCH_HAS_UBSAN_SANITIZE_ALL 74 select ARCH_HAS_ZONE_DEVICE if X86_64 75 select ARCH_HAVE_NMI_SAFE_CMPXCHG 76 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 77 select ARCH_MIGHT_HAVE_PC_PARPORT 78 select ARCH_MIGHT_HAVE_PC_SERIO 79 select ARCH_SUPPORTS_ACPI 80 select ARCH_SUPPORTS_ATOMIC_RMW 81 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 82 select ARCH_USE_BUILTIN_BSWAP 83 select ARCH_USE_QUEUED_RWLOCKS 84 select ARCH_USE_QUEUED_SPINLOCKS 85 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 86 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 87 select ARCH_WANTS_THP_SWAP if X86_64 88 select BUILDTIME_EXTABLE_SORT 89 select CLKEVT_I8253 90 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 91 select CLOCKSOURCE_WATCHDOG 92 select DCACHE_WORD_ACCESS 93 select DMA_DIRECT_OPS 94 select EDAC_ATOMIC_SCRUB 95 select EDAC_SUPPORT 96 select GENERIC_CLOCKEVENTS 97 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 98 select GENERIC_CLOCKEVENTS_MIN_ADJUST 99 select GENERIC_CMOS_UPDATE 100 select GENERIC_CPU_AUTOPROBE 101 select GENERIC_CPU_VULNERABILITIES 102 select GENERIC_EARLY_IOREMAP 103 select GENERIC_FIND_FIRST_BIT 104 select GENERIC_IOMAP 105 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 106 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 107 select GENERIC_IRQ_MIGRATION if SMP 108 select GENERIC_IRQ_PROBE 109 select GENERIC_IRQ_RESERVATION_MODE 110 select GENERIC_IRQ_SHOW 111 select GENERIC_PENDING_IRQ if SMP 112 select GENERIC_SMP_IDLE_THREAD 113 select GENERIC_STRNCPY_FROM_USER 114 select GENERIC_STRNLEN_USER 115 select GENERIC_TIME_VSYSCALL 116 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 117 select HAVE_ACPI_APEI if ACPI 118 select HAVE_ACPI_APEI_NMI if ACPI 119 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 120 select HAVE_ARCH_AUDITSYSCALL 121 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 122 select HAVE_ARCH_JUMP_LABEL 123 select HAVE_ARCH_JUMP_LABEL_RELATIVE 124 select HAVE_ARCH_KASAN if X86_64 125 select HAVE_ARCH_KGDB 126 select HAVE_ARCH_MMAP_RND_BITS if MMU 127 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 128 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 129 select HAVE_ARCH_PREL32_RELOCATIONS 130 select HAVE_ARCH_SECCOMP_FILTER 131 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 132 select HAVE_ARCH_STACKLEAK 133 select HAVE_ARCH_TRACEHOOK 134 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 135 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 136 select HAVE_ARCH_VMAP_STACK if X86_64 137 select HAVE_ARCH_WITHIN_STACK_FRAMES 138 select HAVE_CMPXCHG_DOUBLE 139 select HAVE_CMPXCHG_LOCAL 140 select HAVE_CONTEXT_TRACKING if X86_64 141 select HAVE_COPY_THREAD_TLS 142 select HAVE_C_RECORDMCOUNT 143 select HAVE_DEBUG_KMEMLEAK 144 select HAVE_DEBUG_STACKOVERFLOW 145 select HAVE_DMA_CONTIGUOUS 146 select HAVE_DYNAMIC_FTRACE 147 select HAVE_DYNAMIC_FTRACE_WITH_REGS 148 select HAVE_EBPF_JIT 149 select HAVE_EFFICIENT_UNALIGNED_ACCESS 150 select HAVE_EXIT_THREAD 151 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 152 select HAVE_FTRACE_MCOUNT_RECORD 153 select HAVE_FUNCTION_GRAPH_TRACER 154 select HAVE_FUNCTION_TRACER 155 select HAVE_GCC_PLUGINS 156 select HAVE_HW_BREAKPOINT 157 select HAVE_IDE 158 select HAVE_IOREMAP_PROT 159 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 160 select HAVE_IRQ_TIME_ACCOUNTING 161 select HAVE_KERNEL_BZIP2 162 select HAVE_KERNEL_GZIP 163 select HAVE_KERNEL_LZ4 164 select HAVE_KERNEL_LZMA 165 select HAVE_KERNEL_LZO 166 select HAVE_KERNEL_XZ 167 select HAVE_KPROBES 168 select HAVE_KPROBES_ON_FTRACE 169 select HAVE_FUNCTION_ERROR_INJECTION 170 select HAVE_KRETPROBES 171 select HAVE_KVM 172 select HAVE_LIVEPATCH if X86_64 173 select HAVE_MEMBLOCK_NODE_MAP 174 select HAVE_MIXED_BREAKPOINTS_REGS 175 select HAVE_MOD_ARCH_SPECIFIC 176 select HAVE_NMI 177 select HAVE_OPROFILE 178 select HAVE_OPTPROBES 179 select HAVE_PCSPKR_PLATFORM 180 select HAVE_PERF_EVENTS 181 select HAVE_PERF_EVENTS_NMI 182 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 183 select HAVE_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_LOCKLESS_CONFIG 200 select PERF_EVENTS 201 select RTC_LIB 202 select RTC_MC146818_LIB 203 select SPARSE_IRQ 204 select SRCU 205 select SYSCTL_EXCEPTION_TRACE 206 select THREAD_INFO_IN_TASK 207 select USER_STACKTRACE_SUPPORT 208 select VIRT_TO_BUS 209 select X86_FEATURE_NAMES if PROC_FS 210 211config INSTRUCTION_DECODER 212 def_bool y 213 depends on KPROBES || PERF_EVENTS || UPROBES 214 215config OUTPUT_FORMAT 216 string 217 default "elf32-i386" if X86_32 218 default "elf64-x86-64" if X86_64 219 220config ARCH_DEFCONFIG 221 string 222 default "arch/x86/configs/i386_defconfig" if X86_32 223 default "arch/x86/configs/x86_64_defconfig" if X86_64 224 225config LOCKDEP_SUPPORT 226 def_bool y 227 228config STACKTRACE_SUPPORT 229 def_bool y 230 231config MMU 232 def_bool y 233 234config ARCH_MMAP_RND_BITS_MIN 235 default 28 if 64BIT 236 default 8 237 238config ARCH_MMAP_RND_BITS_MAX 239 default 32 if 64BIT 240 default 16 241 242config ARCH_MMAP_RND_COMPAT_BITS_MIN 243 default 8 244 245config ARCH_MMAP_RND_COMPAT_BITS_MAX 246 default 16 247 248config SBUS 249 bool 250 251config GENERIC_ISA_DMA 252 def_bool y 253 depends on ISA_DMA_API 254 255config GENERIC_BUG 256 def_bool y 257 depends on BUG 258 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 259 260config GENERIC_BUG_RELATIVE_POINTERS 261 bool 262 263config GENERIC_HWEIGHT 264 def_bool y 265 266config ARCH_MAY_HAVE_PC_FDC 267 def_bool y 268 depends on ISA_DMA_API 269 270config RWSEM_XCHGADD_ALGORITHM 271 def_bool y 272 273config GENERIC_CALIBRATE_DELAY 274 def_bool y 275 276config ARCH_HAS_CPU_RELAX 277 def_bool y 278 279config ARCH_HAS_CACHE_LINE_SIZE 280 def_bool y 281 282config ARCH_HAS_FILTER_PGPROT 283 def_bool y 284 285config HAVE_SETUP_PER_CPU_AREA 286 def_bool y 287 288config NEED_PER_CPU_EMBED_FIRST_CHUNK 289 def_bool y 290 291config NEED_PER_CPU_PAGE_FIRST_CHUNK 292 def_bool y 293 294config ARCH_HIBERNATION_POSSIBLE 295 def_bool y 296 297config ARCH_SUSPEND_POSSIBLE 298 def_bool y 299 300config ARCH_WANT_HUGE_PMD_SHARE 301 def_bool y 302 303config ARCH_WANT_GENERAL_HUGETLB 304 def_bool y 305 306config ZONE_DMA32 307 def_bool y if X86_64 308 309config AUDIT_ARCH 310 def_bool y if X86_64 311 312config ARCH_SUPPORTS_OPTIMIZED_INLINING 313 def_bool y 314 315config ARCH_SUPPORTS_DEBUG_PAGEALLOC 316 def_bool y 317 318config KASAN_SHADOW_OFFSET 319 hex 320 depends on KASAN 321 default 0xdffffc0000000000 322 323config HAVE_INTEL_TXT 324 def_bool y 325 depends on INTEL_IOMMU && ACPI 326 327config X86_32_SMP 328 def_bool y 329 depends on X86_32 && SMP 330 331config X86_64_SMP 332 def_bool y 333 depends on X86_64 && SMP 334 335config X86_32_LAZY_GS 336 def_bool y 337 depends on X86_32 && !STACKPROTECTOR 338 339config ARCH_SUPPORTS_UPROBES 340 def_bool y 341 342config FIX_EARLYCON_MEM 343 def_bool y 344 345config DYNAMIC_PHYSICAL_MASK 346 bool 347 348config PGTABLE_LEVELS 349 int 350 default 5 if X86_5LEVEL 351 default 4 if X86_64 352 default 3 if X86_PAE 353 default 2 354 355config CC_HAS_SANE_STACKPROTECTOR 356 bool 357 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 358 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 359 help 360 We have to make sure stack protector is unconditionally disabled if 361 the compiler produces broken code. 362 363menu "Processor type and features" 364 365config ZONE_DMA 366 bool "DMA memory allocation support" if EXPERT 367 default y 368 help 369 DMA memory allocation support allows devices with less than 32-bit 370 addressing to allocate within the first 16MB of address space. 371 Disable if no such devices will be used. 372 373 If unsure, say Y. 374 375config SMP 376 bool "Symmetric multi-processing support" 377 ---help--- 378 This enables support for systems with more than one CPU. If you have 379 a system with only one CPU, say N. If you have a system with more 380 than one CPU, say Y. 381 382 If you say N here, the kernel will run on uni- and multiprocessor 383 machines, but will use only one CPU of a multiprocessor machine. If 384 you say Y here, the kernel will run on many, but not all, 385 uniprocessor machines. On a uniprocessor machine, the kernel 386 will run faster if you say N here. 387 388 Note that if you say Y here and choose architecture "586" or 389 "Pentium" under "Processor family", the kernel will not work on 486 390 architectures. Similarly, multiprocessor kernels for the "PPro" 391 architecture may not work on all Pentium based boards. 392 393 People using multiprocessor machines who say Y here should also say 394 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 395 Management" code will be disabled if you say Y here. 396 397 See also <file:Documentation/x86/i386/IO-APIC.txt>, 398 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 399 <http://www.tldp.org/docs.html#howto>. 400 401 If you don't know what to do here, say N. 402 403config X86_FEATURE_NAMES 404 bool "Processor feature human-readable names" if EMBEDDED 405 default y 406 ---help--- 407 This option compiles in a table of x86 feature bits and corresponding 408 names. This is required to support /proc/cpuinfo and a few kernel 409 messages. You can disable this to save space, at the expense of 410 making those few kernel messages show numeric feature bits instead. 411 412 If in doubt, say Y. 413 414config X86_X2APIC 415 bool "Support x2apic" 416 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 417 ---help--- 418 This enables x2apic support on CPUs that have this feature. 419 420 This allows 32-bit apic IDs (so it can support very large systems), 421 and accesses the local apic via MSRs not via mmio. 422 423 If you don't know what to do here, say N. 424 425config X86_MPPARSE 426 bool "Enable MPS table" if ACPI || SFI 427 default y 428 depends on X86_LOCAL_APIC 429 ---help--- 430 For old smp systems that do not have proper acpi support. Newer systems 431 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 432 433config GOLDFISH 434 def_bool y 435 depends on X86_GOLDFISH 436 437config RETPOLINE 438 bool "Avoid speculative indirect branches in kernel" 439 default y 440 select STACK_VALIDATION if HAVE_STACK_VALIDATION 441 help 442 Compile kernel with the retpoline compiler options to guard against 443 kernel-to-user data leaks by avoiding speculative indirect 444 branches. Requires a compiler with -mindirect-branch=thunk-extern 445 support for full protection. The kernel may run slower. 446 447config RESCTRL 448 bool "Resource Control support" 449 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 450 select KERNFS 451 help 452 Enable Resource Control support. 453 454 Provide support for the allocation and monitoring of system resources 455 usage by the CPU. 456 457 Intel calls this Intel Resource Director Technology 458 (Intel(R) RDT). More information about RDT can be found in the 459 Intel x86 Architecture Software Developer Manual. 460 461 AMD calls this AMD Platform Quality of Service (AMD QoS). 462 More information about AMD QoS can be found in the AMD64 Technology 463 Platform Quality of Service Extensions manual. 464 465 Say N if unsure. 466 467if X86_32 468config X86_BIGSMP 469 bool "Support for big SMP systems with more than 8 CPUs" 470 depends on SMP 471 ---help--- 472 This option is needed for the systems that have more than 8 CPUs 473 474config X86_EXTENDED_PLATFORM 475 bool "Support for extended (non-PC) x86 platforms" 476 default y 477 ---help--- 478 If you disable this option then the kernel will only support 479 standard PC platforms. (which covers the vast majority of 480 systems out there.) 481 482 If you enable this option then you'll be able to select support 483 for the following (non-PC) 32 bit x86 platforms: 484 Goldfish (Android emulator) 485 AMD Elan 486 RDC R-321x SoC 487 SGI 320/540 (Visual Workstation) 488 STA2X11-based (e.g. Northville) 489 Moorestown MID devices 490 491 If you have one of these systems, or if you want to build a 492 generic distribution kernel, say Y here - otherwise say N. 493endif 494 495if X86_64 496config X86_EXTENDED_PLATFORM 497 bool "Support for extended (non-PC) x86 platforms" 498 default y 499 ---help--- 500 If you disable this option then the kernel will only support 501 standard PC platforms. (which covers the vast majority of 502 systems out there.) 503 504 If you enable this option then you'll be able to select support 505 for the following (non-PC) 64 bit x86 platforms: 506 Numascale NumaChip 507 ScaleMP vSMP 508 SGI Ultraviolet 509 510 If you have one of these systems, or if you want to build a 511 generic distribution kernel, say Y here - otherwise say N. 512endif 513# This is an alphabetically sorted list of 64 bit extended platforms 514# Please maintain the alphabetic order if and when there are additions 515config X86_NUMACHIP 516 bool "Numascale NumaChip" 517 depends on X86_64 518 depends on X86_EXTENDED_PLATFORM 519 depends on NUMA 520 depends on SMP 521 depends on X86_X2APIC 522 depends on PCI_MMCONFIG 523 ---help--- 524 Adds support for Numascale NumaChip large-SMP systems. Needed to 525 enable more than ~168 cores. 526 If you don't have one of these, you should say N here. 527 528config X86_VSMP 529 bool "ScaleMP vSMP" 530 select HYPERVISOR_GUEST 531 select PARAVIRT 532 depends on X86_64 && PCI 533 depends on X86_EXTENDED_PLATFORM 534 depends on SMP 535 ---help--- 536 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 537 supposed to run on these EM64T-based machines. Only choose this option 538 if you have one of these machines. 539 540config X86_UV 541 bool "SGI Ultraviolet" 542 depends on X86_64 543 depends on X86_EXTENDED_PLATFORM 544 depends on NUMA 545 depends on EFI 546 depends on X86_X2APIC 547 depends on PCI 548 ---help--- 549 This option is needed in order to support SGI Ultraviolet systems. 550 If you don't have one of these, you should say N here. 551 552# Following is an alphabetically sorted list of 32 bit extended platforms 553# Please maintain the alphabetic order if and when there are additions 554 555config X86_GOLDFISH 556 bool "Goldfish (Virtual Platform)" 557 depends on X86_EXTENDED_PLATFORM 558 ---help--- 559 Enable support for the Goldfish virtual platform used primarily 560 for Android development. Unless you are building for the Android 561 Goldfish emulator say N here. 562 563config X86_INTEL_CE 564 bool "CE4100 TV platform" 565 depends on PCI 566 depends on PCI_GODIRECT 567 depends on X86_IO_APIC 568 depends on X86_32 569 depends on X86_EXTENDED_PLATFORM 570 select X86_REBOOTFIXUPS 571 select OF 572 select OF_EARLY_FLATTREE 573 ---help--- 574 Select for the Intel CE media processor (CE4100) SOC. 575 This option compiles in support for the CE4100 SOC for settop 576 boxes and media devices. 577 578config X86_INTEL_MID 579 bool "Intel MID platform support" 580 depends on X86_EXTENDED_PLATFORM 581 depends on X86_PLATFORM_DEVICES 582 depends on PCI 583 depends on X86_64 || (PCI_GOANY && X86_32) 584 depends on X86_IO_APIC 585 select SFI 586 select I2C 587 select DW_APB_TIMER 588 select APB_TIMER 589 select INTEL_SCU_IPC 590 select MFD_INTEL_MSIC 591 ---help--- 592 Select to build a kernel capable of supporting Intel MID (Mobile 593 Internet Device) platform systems which do not have the PCI legacy 594 interfaces. If you are building for a PC class system say N here. 595 596 Intel MID platforms are based on an Intel processor and chipset which 597 consume less power than most of the x86 derivatives. 598 599config X86_INTEL_QUARK 600 bool "Intel Quark platform support" 601 depends on X86_32 602 depends on X86_EXTENDED_PLATFORM 603 depends on X86_PLATFORM_DEVICES 604 depends on X86_TSC 605 depends on PCI 606 depends on PCI_GOANY 607 depends on X86_IO_APIC 608 select IOSF_MBI 609 select INTEL_IMR 610 select COMMON_CLK 611 ---help--- 612 Select to include support for Quark X1000 SoC. 613 Say Y here if you have a Quark based system such as the Arduino 614 compatible Intel Galileo. 615 616config X86_INTEL_LPSS 617 bool "Intel Low Power Subsystem Support" 618 depends on X86 && ACPI 619 select COMMON_CLK 620 select PINCTRL 621 select IOSF_MBI 622 ---help--- 623 Select to build support for Intel Low Power Subsystem such as 624 found on Intel Lynxpoint PCH. Selecting this option enables 625 things like clock tree (common clock framework) and pincontrol 626 which are needed by the LPSS peripheral drivers. 627 628config X86_AMD_PLATFORM_DEVICE 629 bool "AMD ACPI2Platform devices support" 630 depends on ACPI 631 select COMMON_CLK 632 select PINCTRL 633 ---help--- 634 Select to interpret AMD specific ACPI device to platform device 635 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 636 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 637 implemented under PINCTRL subsystem. 638 639config IOSF_MBI 640 tristate "Intel SoC IOSF Sideband support for SoC platforms" 641 depends on PCI 642 ---help--- 643 This option enables sideband register access support for Intel SoC 644 platforms. On these platforms the IOSF sideband is used in lieu of 645 MSR's for some register accesses, mostly but not limited to thermal 646 and power. Drivers may query the availability of this device to 647 determine if they need the sideband in order to work on these 648 platforms. The sideband is available on the following SoC products. 649 This list is not meant to be exclusive. 650 - BayTrail 651 - Braswell 652 - Quark 653 654 You should say Y if you are running a kernel on one of these SoC's. 655 656config IOSF_MBI_DEBUG 657 bool "Enable IOSF sideband access through debugfs" 658 depends on IOSF_MBI && DEBUG_FS 659 ---help--- 660 Select this option to expose the IOSF sideband access registers (MCR, 661 MDR, MCRX) through debugfs to write and read register information from 662 different units on the SoC. This is most useful for obtaining device 663 state information for debug and analysis. As this is a general access 664 mechanism, users of this option would have specific knowledge of the 665 device they want to access. 666 667 If you don't require the option or are in doubt, say N. 668 669config X86_RDC321X 670 bool "RDC R-321x SoC" 671 depends on X86_32 672 depends on X86_EXTENDED_PLATFORM 673 select M486 674 select X86_REBOOTFIXUPS 675 ---help--- 676 This option is needed for RDC R-321x system-on-chip, also known 677 as R-8610-(G). 678 If you don't have one of these chips, you should say N here. 679 680config X86_32_NON_STANDARD 681 bool "Support non-standard 32-bit SMP architectures" 682 depends on X86_32 && SMP 683 depends on X86_EXTENDED_PLATFORM 684 ---help--- 685 This option compiles in the bigsmp and STA2X11 default 686 subarchitectures. It is intended for a generic binary 687 kernel. If you select them all, kernel will probe it one by 688 one and will fallback to default. 689 690# Alphabetically sorted list of Non standard 32 bit platforms 691 692config X86_SUPPORTS_MEMORY_FAILURE 693 def_bool y 694 # MCE code calls memory_failure(): 695 depends on X86_MCE 696 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 697 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 698 depends on X86_64 || !SPARSEMEM 699 select ARCH_SUPPORTS_MEMORY_FAILURE 700 701config STA2X11 702 bool "STA2X11 Companion Chip Support" 703 depends on X86_32_NON_STANDARD && PCI 704 select ARCH_HAS_PHYS_TO_DMA 705 select X86_DEV_DMA_OPS 706 select X86_DMA_REMAP 707 select SWIOTLB 708 select MFD_STA2X11 709 select GPIOLIB 710 ---help--- 711 This adds support for boards based on the STA2X11 IO-Hub, 712 a.k.a. "ConneXt". The chip is used in place of the standard 713 PC chipset, so all "standard" peripherals are missing. If this 714 option is selected the kernel will still be able to boot on 715 standard PC machines. 716 717config X86_32_IRIS 718 tristate "Eurobraille/Iris poweroff module" 719 depends on X86_32 720 ---help--- 721 The Iris machines from EuroBraille do not have APM or ACPI support 722 to shut themselves down properly. A special I/O sequence is 723 needed to do so, which is what this module does at 724 kernel shutdown. 725 726 This is only for Iris machines from EuroBraille. 727 728 If unused, say N. 729 730config SCHED_OMIT_FRAME_POINTER 731 def_bool y 732 prompt "Single-depth WCHAN output" 733 depends on X86 734 ---help--- 735 Calculate simpler /proc/<PID>/wchan values. If this option 736 is disabled then wchan values will recurse back to the 737 caller function. This provides more accurate wchan values, 738 at the expense of slightly more scheduling overhead. 739 740 If in doubt, say "Y". 741 742menuconfig HYPERVISOR_GUEST 743 bool "Linux guest support" 744 ---help--- 745 Say Y here to enable options for running Linux under various hyper- 746 visors. This option enables basic hypervisor detection and platform 747 setup. 748 749 If you say N, all options in this submenu will be skipped and 750 disabled, and Linux guest support won't be built in. 751 752if HYPERVISOR_GUEST 753 754config PARAVIRT 755 bool "Enable paravirtualization code" 756 ---help--- 757 This changes the kernel so it can modify itself when it is run 758 under a hypervisor, potentially improving performance significantly 759 over full virtualization. However, when run without a hypervisor 760 the kernel is theoretically slower and slightly larger. 761 762config PARAVIRT_XXL 763 bool 764 765config PARAVIRT_DEBUG 766 bool "paravirt-ops debugging" 767 depends on PARAVIRT && DEBUG_KERNEL 768 ---help--- 769 Enable to debug paravirt_ops internals. Specifically, BUG if 770 a paravirt_op is missing when it is called. 771 772config PARAVIRT_SPINLOCKS 773 bool "Paravirtualization layer for spinlocks" 774 depends on PARAVIRT && SMP 775 ---help--- 776 Paravirtualized spinlocks allow a pvops backend to replace the 777 spinlock implementation with something virtualization-friendly 778 (for example, block the virtual CPU rather than spinning). 779 780 It has a minimal impact on native kernels and gives a nice performance 781 benefit on paravirtualized KVM / Xen kernels. 782 783 If you are unsure how to answer this question, answer Y. 784 785config QUEUED_LOCK_STAT 786 bool "Paravirt queued spinlock statistics" 787 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 788 ---help--- 789 Enable the collection of statistical data on the slowpath 790 behavior of paravirtualized queued spinlocks and report 791 them on debugfs. 792 793source "arch/x86/xen/Kconfig" 794 795config KVM_GUEST 796 bool "KVM Guest support (including kvmclock)" 797 depends on PARAVIRT 798 select PARAVIRT_CLOCK 799 default y 800 ---help--- 801 This option enables various optimizations for running under the KVM 802 hypervisor. It includes a paravirtualized clock, so that instead 803 of relying on a PIT (or probably other) emulation by the 804 underlying device model, the host provides the guest with 805 timing infrastructure such as time of day, and system time 806 807config PVH 808 bool "Support for running PVH guests" 809 ---help--- 810 This option enables the PVH entry point for guest virtual machines 811 as specified in the x86/HVM direct boot ABI. 812 813config KVM_DEBUG_FS 814 bool "Enable debug information for KVM Guests in debugfs" 815 depends on KVM_GUEST && DEBUG_FS 816 ---help--- 817 This option enables collection of various statistics for KVM guest. 818 Statistics are displayed in debugfs filesystem. Enabling this option 819 may incur significant overhead. 820 821config PARAVIRT_TIME_ACCOUNTING 822 bool "Paravirtual steal time accounting" 823 depends on PARAVIRT 824 ---help--- 825 Select this option to enable fine granularity task steal time 826 accounting. Time spent executing other tasks in parallel with 827 the current vCPU is discounted from the vCPU power. To account for 828 that, there can be a small performance impact. 829 830 If in doubt, say N here. 831 832config PARAVIRT_CLOCK 833 bool 834 835config JAILHOUSE_GUEST 836 bool "Jailhouse non-root cell support" 837 depends on X86_64 && PCI 838 select X86_PM_TIMER 839 ---help--- 840 This option allows to run Linux as guest in a Jailhouse non-root 841 cell. You can leave this option disabled if you only want to start 842 Jailhouse and run Linux afterwards in the root cell. 843 844endif #HYPERVISOR_GUEST 845 846source "arch/x86/Kconfig.cpu" 847 848config HPET_TIMER 849 def_bool X86_64 850 prompt "HPET Timer Support" if X86_32 851 ---help--- 852 Use the IA-PC HPET (High Precision Event Timer) to manage 853 time in preference to the PIT and RTC, if a HPET is 854 present. 855 HPET is the next generation timer replacing legacy 8254s. 856 The HPET provides a stable time base on SMP 857 systems, unlike the TSC, but it is more expensive to access, 858 as it is off-chip. The interface used is documented 859 in the HPET spec, revision 1. 860 861 You can safely choose Y here. However, HPET will only be 862 activated if the platform and the BIOS support this feature. 863 Otherwise the 8254 will be used for timing services. 864 865 Choose N to continue using the legacy 8254 timer. 866 867config HPET_EMULATE_RTC 868 def_bool y 869 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 870 871config APB_TIMER 872 def_bool y if X86_INTEL_MID 873 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 874 select DW_APB_TIMER 875 depends on X86_INTEL_MID && SFI 876 help 877 APB timer is the replacement for 8254, HPET on X86 MID platforms. 878 The APBT provides a stable time base on SMP 879 systems, unlike the TSC, but it is more expensive to access, 880 as it is off-chip. APB timers are always running regardless of CPU 881 C states, they are used as per CPU clockevent device when possible. 882 883# Mark as expert because too many people got it wrong. 884# The code disables itself when not needed. 885config DMI 886 default y 887 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 888 bool "Enable DMI scanning" if EXPERT 889 ---help--- 890 Enabled scanning of DMI to identify machine quirks. Say Y 891 here unless you have verified that your setup is not 892 affected by entries in the DMI blacklist. Required by PNP 893 BIOS code. 894 895config GART_IOMMU 896 bool "Old AMD GART IOMMU support" 897 select IOMMU_HELPER 898 select SWIOTLB 899 depends on X86_64 && PCI && AMD_NB 900 ---help--- 901 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 902 GART based hardware IOMMUs. 903 904 The GART supports full DMA access for devices with 32-bit access 905 limitations, on systems with more than 3 GB. This is usually needed 906 for USB, sound, many IDE/SATA chipsets and some other devices. 907 908 Newer systems typically have a modern AMD IOMMU, supported via 909 the CONFIG_AMD_IOMMU=y config option. 910 911 In normal configurations this driver is only active when needed: 912 there's more than 3 GB of memory and the system contains a 913 32-bit limited device. 914 915 If unsure, say Y. 916 917config CALGARY_IOMMU 918 bool "IBM Calgary IOMMU support" 919 select IOMMU_HELPER 920 select SWIOTLB 921 depends on X86_64 && PCI 922 ---help--- 923 Support for hardware IOMMUs in IBM's xSeries x366 and x460 924 systems. Needed to run systems with more than 3GB of memory 925 properly with 32-bit PCI devices that do not support DAC 926 (Double Address Cycle). Calgary also supports bus level 927 isolation, where all DMAs pass through the IOMMU. This 928 prevents them from going anywhere except their intended 929 destination. This catches hard-to-find kernel bugs and 930 mis-behaving drivers and devices that do not use the DMA-API 931 properly to set up their DMA buffers. The IOMMU can be 932 turned off at boot time with the iommu=off parameter. 933 Normally the kernel will make the right choice by itself. 934 If unsure, say Y. 935 936config CALGARY_IOMMU_ENABLED_BY_DEFAULT 937 def_bool y 938 prompt "Should Calgary be enabled by default?" 939 depends on CALGARY_IOMMU 940 ---help--- 941 Should Calgary be enabled by default? if you choose 'y', Calgary 942 will be used (if it exists). If you choose 'n', Calgary will not be 943 used even if it exists. If you choose 'n' and would like to use 944 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 945 If unsure, say Y. 946 947config MAXSMP 948 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 949 depends on X86_64 && SMP && DEBUG_KERNEL 950 select CPUMASK_OFFSTACK 951 ---help--- 952 Enable maximum number of CPUS and NUMA Nodes for this architecture. 953 If unsure, say N. 954 955# 956# The maximum number of CPUs supported: 957# 958# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 959# and which can be configured interactively in the 960# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 961# 962# The ranges are different on 32-bit and 64-bit kernels, depending on 963# hardware capabilities and scalability features of the kernel. 964# 965# ( If MAXSMP is enabled we just use the highest possible value and disable 966# interactive configuration. ) 967# 968 969config NR_CPUS_RANGE_BEGIN 970 int 971 default NR_CPUS_RANGE_END if MAXSMP 972 default 1 if !SMP 973 default 2 974 975config NR_CPUS_RANGE_END 976 int 977 depends on X86_32 978 default 64 if SMP && X86_BIGSMP 979 default 8 if SMP && !X86_BIGSMP 980 default 1 if !SMP 981 982config NR_CPUS_RANGE_END 983 int 984 depends on X86_64 985 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 986 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 987 default 1 if !SMP 988 989config NR_CPUS_DEFAULT 990 int 991 depends on X86_32 992 default 32 if X86_BIGSMP 993 default 8 if SMP 994 default 1 if !SMP 995 996config NR_CPUS_DEFAULT 997 int 998 depends on X86_64 999 default 8192 if MAXSMP 1000 default 64 if SMP 1001 default 1 if !SMP 1002 1003config NR_CPUS 1004 int "Maximum number of CPUs" if SMP && !MAXSMP 1005 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1006 default NR_CPUS_DEFAULT 1007 ---help--- 1008 This allows you to specify the maximum number of CPUs which this 1009 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1010 supported value is 8192, otherwise the maximum value is 512. The 1011 minimum value which makes sense is 2. 1012 1013 This is purely to save memory: each supported CPU adds about 8KB 1014 to the kernel image. 1015 1016config SCHED_SMT 1017 def_bool y if SMP 1018 1019config SCHED_MC 1020 def_bool y 1021 prompt "Multi-core scheduler support" 1022 depends on SMP 1023 ---help--- 1024 Multi-core scheduler support improves the CPU scheduler's decision 1025 making when dealing with multi-core CPU chips at a cost of slightly 1026 increased overhead in some places. If unsure say N here. 1027 1028config SCHED_MC_PRIO 1029 bool "CPU core priorities scheduler support" 1030 depends on SCHED_MC && CPU_SUP_INTEL 1031 select X86_INTEL_PSTATE 1032 select CPU_FREQ 1033 default y 1034 ---help--- 1035 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1036 core ordering determined at manufacturing time, which allows 1037 certain cores to reach higher turbo frequencies (when running 1038 single threaded workloads) than others. 1039 1040 Enabling this kernel feature teaches the scheduler about 1041 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1042 scheduler's CPU selection logic accordingly, so that higher 1043 overall system performance can be achieved. 1044 1045 This feature will have no effect on CPUs without this feature. 1046 1047 If unsure say Y here. 1048 1049config UP_LATE_INIT 1050 def_bool y 1051 depends on !SMP && X86_LOCAL_APIC 1052 1053config X86_UP_APIC 1054 bool "Local APIC support on uniprocessors" if !PCI_MSI 1055 default PCI_MSI 1056 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1057 ---help--- 1058 A local APIC (Advanced Programmable Interrupt Controller) is an 1059 integrated interrupt controller in the CPU. If you have a single-CPU 1060 system which has a processor with a local APIC, you can say Y here to 1061 enable and use it. If you say Y here even though your machine doesn't 1062 have a local APIC, then the kernel will still run with no slowdown at 1063 all. The local APIC supports CPU-generated self-interrupts (timer, 1064 performance counters), and the NMI watchdog which detects hard 1065 lockups. 1066 1067config X86_UP_IOAPIC 1068 bool "IO-APIC support on uniprocessors" 1069 depends on X86_UP_APIC 1070 ---help--- 1071 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1072 SMP-capable replacement for PC-style interrupt controllers. Most 1073 SMP systems and many recent uniprocessor systems have one. 1074 1075 If you have a single-CPU system with an IO-APIC, you can say Y here 1076 to use it. If you say Y here even though your machine doesn't have 1077 an IO-APIC, then the kernel will still run with no slowdown at all. 1078 1079config X86_LOCAL_APIC 1080 def_bool y 1081 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1082 select IRQ_DOMAIN_HIERARCHY 1083 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1084 1085config X86_IO_APIC 1086 def_bool y 1087 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1088 1089config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1090 bool "Reroute for broken boot IRQs" 1091 depends on X86_IO_APIC 1092 ---help--- 1093 This option enables a workaround that fixes a source of 1094 spurious interrupts. This is recommended when threaded 1095 interrupt handling is used on systems where the generation of 1096 superfluous "boot interrupts" cannot be disabled. 1097 1098 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1099 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1100 kernel does during interrupt handling). On chipsets where this 1101 boot IRQ generation cannot be disabled, this workaround keeps 1102 the original IRQ line masked so that only the equivalent "boot 1103 IRQ" is delivered to the CPUs. The workaround also tells the 1104 kernel to set up the IRQ handler on the boot IRQ line. In this 1105 way only one interrupt is delivered to the kernel. Otherwise 1106 the spurious second interrupt may cause the kernel to bring 1107 down (vital) interrupt lines. 1108 1109 Only affects "broken" chipsets. Interrupt sharing may be 1110 increased on these systems. 1111 1112config X86_MCE 1113 bool "Machine Check / overheating reporting" 1114 select GENERIC_ALLOCATOR 1115 default y 1116 ---help--- 1117 Machine Check support allows the processor to notify the 1118 kernel if it detects a problem (e.g. overheating, data corruption). 1119 The action the kernel takes depends on the severity of the problem, 1120 ranging from warning messages to halting the machine. 1121 1122config X86_MCELOG_LEGACY 1123 bool "Support for deprecated /dev/mcelog character device" 1124 depends on X86_MCE 1125 ---help--- 1126 Enable support for /dev/mcelog which is needed by the old mcelog 1127 userspace logging daemon. Consider switching to the new generation 1128 rasdaemon solution. 1129 1130config X86_MCE_INTEL 1131 def_bool y 1132 prompt "Intel MCE features" 1133 depends on X86_MCE && X86_LOCAL_APIC 1134 ---help--- 1135 Additional support for intel specific MCE features such as 1136 the thermal monitor. 1137 1138config X86_MCE_AMD 1139 def_bool y 1140 prompt "AMD MCE features" 1141 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1142 ---help--- 1143 Additional support for AMD specific MCE features such as 1144 the DRAM Error Threshold. 1145 1146config X86_ANCIENT_MCE 1147 bool "Support for old Pentium 5 / WinChip machine checks" 1148 depends on X86_32 && X86_MCE 1149 ---help--- 1150 Include support for machine check handling on old Pentium 5 or WinChip 1151 systems. These typically need to be enabled explicitly on the command 1152 line. 1153 1154config X86_MCE_THRESHOLD 1155 depends on X86_MCE_AMD || X86_MCE_INTEL 1156 def_bool y 1157 1158config X86_MCE_INJECT 1159 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1160 tristate "Machine check injector support" 1161 ---help--- 1162 Provide support for injecting machine checks for testing purposes. 1163 If you don't know what a machine check is and you don't do kernel 1164 QA it is safe to say n. 1165 1166config X86_THERMAL_VECTOR 1167 def_bool y 1168 depends on X86_MCE_INTEL 1169 1170source "arch/x86/events/Kconfig" 1171 1172config X86_LEGACY_VM86 1173 bool "Legacy VM86 support" 1174 depends on X86_32 1175 ---help--- 1176 This option allows user programs to put the CPU into V8086 1177 mode, which is an 80286-era approximation of 16-bit real mode. 1178 1179 Some very old versions of X and/or vbetool require this option 1180 for user mode setting. Similarly, DOSEMU will use it if 1181 available to accelerate real mode DOS programs. However, any 1182 recent version of DOSEMU, X, or vbetool should be fully 1183 functional even without kernel VM86 support, as they will all 1184 fall back to software emulation. Nevertheless, if you are using 1185 a 16-bit DOS program where 16-bit performance matters, vm86 1186 mode might be faster than emulation and you might want to 1187 enable this option. 1188 1189 Note that any app that works on a 64-bit kernel is unlikely to 1190 need this option, as 64-bit kernels don't, and can't, support 1191 V8086 mode. This option is also unrelated to 16-bit protected 1192 mode and is not needed to run most 16-bit programs under Wine. 1193 1194 Enabling this option increases the complexity of the kernel 1195 and slows down exception handling a tiny bit. 1196 1197 If unsure, say N here. 1198 1199config VM86 1200 bool 1201 default X86_LEGACY_VM86 1202 1203config X86_16BIT 1204 bool "Enable support for 16-bit segments" if EXPERT 1205 default y 1206 depends on MODIFY_LDT_SYSCALL 1207 ---help--- 1208 This option is required by programs like Wine to run 16-bit 1209 protected mode legacy code on x86 processors. Disabling 1210 this option saves about 300 bytes on i386, or around 6K text 1211 plus 16K runtime memory on x86-64, 1212 1213config X86_ESPFIX32 1214 def_bool y 1215 depends on X86_16BIT && X86_32 1216 1217config X86_ESPFIX64 1218 def_bool y 1219 depends on X86_16BIT && X86_64 1220 1221config X86_VSYSCALL_EMULATION 1222 bool "Enable vsyscall emulation" if EXPERT 1223 default y 1224 depends on X86_64 1225 ---help--- 1226 This enables emulation of the legacy vsyscall page. Disabling 1227 it is roughly equivalent to booting with vsyscall=none, except 1228 that it will also disable the helpful warning if a program 1229 tries to use a vsyscall. With this option set to N, offending 1230 programs will just segfault, citing addresses of the form 1231 0xffffffffff600?00. 1232 1233 This option is required by many programs built before 2013, and 1234 care should be used even with newer programs if set to N. 1235 1236 Disabling this option saves about 7K of kernel size and 1237 possibly 4K of additional runtime pagetable memory. 1238 1239config TOSHIBA 1240 tristate "Toshiba Laptop support" 1241 depends on X86_32 1242 ---help--- 1243 This adds a driver to safely access the System Management Mode of 1244 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1245 not work on models with a Phoenix BIOS. The System Management Mode 1246 is used to set the BIOS and power saving options on Toshiba portables. 1247 1248 For information on utilities to make use of this driver see the 1249 Toshiba Linux utilities web site at: 1250 <http://www.buzzard.org.uk/toshiba/>. 1251 1252 Say Y if you intend to run this kernel on a Toshiba portable. 1253 Say N otherwise. 1254 1255config I8K 1256 tristate "Dell i8k legacy laptop support" 1257 select HWMON 1258 select SENSORS_DELL_SMM 1259 ---help--- 1260 This option enables legacy /proc/i8k userspace interface in hwmon 1261 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1262 temperature and allows controlling fan speeds of Dell laptops via 1263 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1264 it reports also power and hotkey status. For fan speed control is 1265 needed userspace package i8kutils. 1266 1267 Say Y if you intend to run this kernel on old Dell laptops or want to 1268 use userspace package i8kutils. 1269 Say N otherwise. 1270 1271config X86_REBOOTFIXUPS 1272 bool "Enable X86 board specific fixups for reboot" 1273 depends on X86_32 1274 ---help--- 1275 This enables chipset and/or board specific fixups to be done 1276 in order to get reboot to work correctly. This is only needed on 1277 some combinations of hardware and BIOS. The symptom, for which 1278 this config is intended, is when reboot ends with a stalled/hung 1279 system. 1280 1281 Currently, the only fixup is for the Geode machines using 1282 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1283 1284 Say Y if you want to enable the fixup. Currently, it's safe to 1285 enable this option even if you don't need it. 1286 Say N otherwise. 1287 1288config MICROCODE 1289 bool "CPU microcode loading support" 1290 default y 1291 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1292 select FW_LOADER 1293 ---help--- 1294 If you say Y here, you will be able to update the microcode on 1295 Intel and AMD processors. The Intel support is for the IA32 family, 1296 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1297 AMD support is for families 0x10 and later. You will obviously need 1298 the actual microcode binary data itself which is not shipped with 1299 the Linux kernel. 1300 1301 The preferred method to load microcode from a detached initrd is described 1302 in Documentation/x86/microcode.txt. For that you need to enable 1303 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1304 initrd for microcode blobs. 1305 1306 In addition, you can build the microcode into the kernel. For that you 1307 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1308 config option. 1309 1310config MICROCODE_INTEL 1311 bool "Intel microcode loading support" 1312 depends on MICROCODE 1313 default MICROCODE 1314 select FW_LOADER 1315 ---help--- 1316 This options enables microcode patch loading support for Intel 1317 processors. 1318 1319 For the current Intel microcode data package go to 1320 <https://downloadcenter.intel.com> and search for 1321 'Linux Processor Microcode Data File'. 1322 1323config MICROCODE_AMD 1324 bool "AMD microcode loading support" 1325 depends on MICROCODE 1326 select FW_LOADER 1327 ---help--- 1328 If you select this option, microcode patch loading support for AMD 1329 processors will be enabled. 1330 1331config MICROCODE_OLD_INTERFACE 1332 def_bool y 1333 depends on MICROCODE 1334 1335config X86_MSR 1336 tristate "/dev/cpu/*/msr - Model-specific register support" 1337 ---help--- 1338 This device gives privileged processes access to the x86 1339 Model-Specific Registers (MSRs). It is a character device with 1340 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1341 MSR accesses are directed to a specific CPU on multi-processor 1342 systems. 1343 1344config X86_CPUID 1345 tristate "/dev/cpu/*/cpuid - CPU information support" 1346 ---help--- 1347 This device gives processes access to the x86 CPUID instruction to 1348 be executed on a specific processor. It is a character device 1349 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1350 /dev/cpu/31/cpuid. 1351 1352choice 1353 prompt "High Memory Support" 1354 default HIGHMEM4G 1355 depends on X86_32 1356 1357config NOHIGHMEM 1358 bool "off" 1359 ---help--- 1360 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1361 However, the address space of 32-bit x86 processors is only 4 1362 Gigabytes large. That means that, if you have a large amount of 1363 physical memory, not all of it can be "permanently mapped" by the 1364 kernel. The physical memory that's not permanently mapped is called 1365 "high memory". 1366 1367 If you are compiling a kernel which will never run on a machine with 1368 more than 1 Gigabyte total physical RAM, answer "off" here (default 1369 choice and suitable for most users). This will result in a "3GB/1GB" 1370 split: 3GB are mapped so that each process sees a 3GB virtual memory 1371 space and the remaining part of the 4GB virtual memory space is used 1372 by the kernel to permanently map as much physical memory as 1373 possible. 1374 1375 If the machine has between 1 and 4 Gigabytes physical RAM, then 1376 answer "4GB" here. 1377 1378 If more than 4 Gigabytes is used then answer "64GB" here. This 1379 selection turns Intel PAE (Physical Address Extension) mode on. 1380 PAE implements 3-level paging on IA32 processors. PAE is fully 1381 supported by Linux, PAE mode is implemented on all recent Intel 1382 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1383 then the kernel will not boot on CPUs that don't support PAE! 1384 1385 The actual amount of total physical memory will either be 1386 auto detected or can be forced by using a kernel command line option 1387 such as "mem=256M". (Try "man bootparam" or see the documentation of 1388 your boot loader (lilo or loadlin) about how to pass options to the 1389 kernel at boot time.) 1390 1391 If unsure, say "off". 1392 1393config HIGHMEM4G 1394 bool "4GB" 1395 ---help--- 1396 Select this if you have a 32-bit processor and between 1 and 4 1397 gigabytes of physical RAM. 1398 1399config HIGHMEM64G 1400 bool "64GB" 1401 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1402 select X86_PAE 1403 ---help--- 1404 Select this if you have a 32-bit processor and more than 4 1405 gigabytes of physical RAM. 1406 1407endchoice 1408 1409choice 1410 prompt "Memory split" if EXPERT 1411 default VMSPLIT_3G 1412 depends on X86_32 1413 ---help--- 1414 Select the desired split between kernel and user memory. 1415 1416 If the address range available to the kernel is less than the 1417 physical memory installed, the remaining memory will be available 1418 as "high memory". Accessing high memory is a little more costly 1419 than low memory, as it needs to be mapped into the kernel first. 1420 Note that increasing the kernel address space limits the range 1421 available to user programs, making the address space there 1422 tighter. Selecting anything other than the default 3G/1G split 1423 will also likely make your kernel incompatible with binary-only 1424 kernel modules. 1425 1426 If you are not absolutely sure what you are doing, leave this 1427 option alone! 1428 1429 config VMSPLIT_3G 1430 bool "3G/1G user/kernel split" 1431 config VMSPLIT_3G_OPT 1432 depends on !X86_PAE 1433 bool "3G/1G user/kernel split (for full 1G low memory)" 1434 config VMSPLIT_2G 1435 bool "2G/2G user/kernel split" 1436 config VMSPLIT_2G_OPT 1437 depends on !X86_PAE 1438 bool "2G/2G user/kernel split (for full 2G low memory)" 1439 config VMSPLIT_1G 1440 bool "1G/3G user/kernel split" 1441endchoice 1442 1443config PAGE_OFFSET 1444 hex 1445 default 0xB0000000 if VMSPLIT_3G_OPT 1446 default 0x80000000 if VMSPLIT_2G 1447 default 0x78000000 if VMSPLIT_2G_OPT 1448 default 0x40000000 if VMSPLIT_1G 1449 default 0xC0000000 1450 depends on X86_32 1451 1452config HIGHMEM 1453 def_bool y 1454 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1455 1456config X86_PAE 1457 bool "PAE (Physical Address Extension) Support" 1458 depends on X86_32 && !HIGHMEM4G 1459 select PHYS_ADDR_T_64BIT 1460 select SWIOTLB 1461 ---help--- 1462 PAE is required for NX support, and furthermore enables 1463 larger swapspace support for non-overcommit purposes. It 1464 has the cost of more pagetable lookup overhead, and also 1465 consumes more pagetable space per process. 1466 1467config X86_5LEVEL 1468 bool "Enable 5-level page tables support" 1469 select DYNAMIC_MEMORY_LAYOUT 1470 select SPARSEMEM_VMEMMAP 1471 depends on X86_64 1472 ---help--- 1473 5-level paging enables access to larger address space: 1474 upto 128 PiB of virtual address space and 4 PiB of 1475 physical address space. 1476 1477 It will be supported by future Intel CPUs. 1478 1479 A kernel with the option enabled can be booted on machines that 1480 support 4- or 5-level paging. 1481 1482 See Documentation/x86/x86_64/5level-paging.txt for more 1483 information. 1484 1485 Say N if unsure. 1486 1487config X86_DIRECT_GBPAGES 1488 def_bool y 1489 depends on X86_64 && !DEBUG_PAGEALLOC 1490 ---help--- 1491 Certain kernel features effectively disable kernel 1492 linear 1 GB mappings (even if the CPU otherwise 1493 supports them), so don't confuse the user by printing 1494 that we have them enabled. 1495 1496config X86_CPA_STATISTICS 1497 bool "Enable statistic for Change Page Attribute" 1498 depends on DEBUG_FS 1499 ---help--- 1500 Expose statistics about the Change Page Attribute mechanims, which 1501 helps to determine the effectivness of preserving large and huge 1502 page mappings when mapping protections are changed. 1503 1504config ARCH_HAS_MEM_ENCRYPT 1505 def_bool y 1506 1507config AMD_MEM_ENCRYPT 1508 bool "AMD Secure Memory Encryption (SME) support" 1509 depends on X86_64 && CPU_SUP_AMD 1510 select DYNAMIC_PHYSICAL_MASK 1511 ---help--- 1512 Say yes to enable support for the encryption of system memory. 1513 This requires an AMD processor that supports Secure Memory 1514 Encryption (SME). 1515 1516config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1517 bool "Activate AMD Secure Memory Encryption (SME) by default" 1518 default y 1519 depends on AMD_MEM_ENCRYPT 1520 ---help--- 1521 Say yes to have system memory encrypted by default if running on 1522 an AMD processor that supports Secure Memory Encryption (SME). 1523 1524 If set to Y, then the encryption of system memory can be 1525 deactivated with the mem_encrypt=off command line option. 1526 1527 If set to N, then the encryption of system memory can be 1528 activated with the mem_encrypt=on command line option. 1529 1530config ARCH_USE_MEMREMAP_PROT 1531 def_bool y 1532 depends on AMD_MEM_ENCRYPT 1533 1534# Common NUMA Features 1535config NUMA 1536 bool "Numa Memory Allocation and Scheduler Support" 1537 depends on SMP 1538 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1539 default y if X86_BIGSMP 1540 ---help--- 1541 Enable NUMA (Non Uniform Memory Access) support. 1542 1543 The kernel will try to allocate memory used by a CPU on the 1544 local memory controller of the CPU and add some more 1545 NUMA awareness to the kernel. 1546 1547 For 64-bit this is recommended if the system is Intel Core i7 1548 (or later), AMD Opteron, or EM64T NUMA. 1549 1550 For 32-bit this is only needed if you boot a 32-bit 1551 kernel on a 64-bit NUMA platform. 1552 1553 Otherwise, you should say N. 1554 1555config AMD_NUMA 1556 def_bool y 1557 prompt "Old style AMD Opteron NUMA detection" 1558 depends on X86_64 && NUMA && PCI 1559 ---help--- 1560 Enable AMD NUMA node topology detection. You should say Y here if 1561 you have a multi processor AMD system. This uses an old method to 1562 read the NUMA configuration directly from the builtin Northbridge 1563 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1564 which also takes priority if both are compiled in. 1565 1566config X86_64_ACPI_NUMA 1567 def_bool y 1568 prompt "ACPI NUMA detection" 1569 depends on X86_64 && NUMA && ACPI && PCI 1570 select ACPI_NUMA 1571 ---help--- 1572 Enable ACPI SRAT based node topology detection. 1573 1574# Some NUMA nodes have memory ranges that span 1575# other nodes. Even though a pfn is valid and 1576# between a node's start and end pfns, it may not 1577# reside on that node. See memmap_init_zone() 1578# for details. 1579config NODES_SPAN_OTHER_NODES 1580 def_bool y 1581 depends on X86_64_ACPI_NUMA 1582 1583config NUMA_EMU 1584 bool "NUMA emulation" 1585 depends on NUMA 1586 ---help--- 1587 Enable NUMA emulation. A flat machine will be split 1588 into virtual nodes when booted with "numa=fake=N", where N is the 1589 number of nodes. This is only useful for debugging. 1590 1591config NODES_SHIFT 1592 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1593 range 1 10 1594 default "10" if MAXSMP 1595 default "6" if X86_64 1596 default "3" 1597 depends on NEED_MULTIPLE_NODES 1598 ---help--- 1599 Specify the maximum number of NUMA Nodes available on the target 1600 system. Increases memory reserved to accommodate various tables. 1601 1602config ARCH_HAVE_MEMORY_PRESENT 1603 def_bool y 1604 depends on X86_32 && DISCONTIGMEM 1605 1606config ARCH_FLATMEM_ENABLE 1607 def_bool y 1608 depends on X86_32 && !NUMA 1609 1610config ARCH_DISCONTIGMEM_ENABLE 1611 def_bool y 1612 depends on NUMA && X86_32 1613 1614config ARCH_DISCONTIGMEM_DEFAULT 1615 def_bool y 1616 depends on NUMA && X86_32 1617 1618config ARCH_SPARSEMEM_ENABLE 1619 def_bool y 1620 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1621 select SPARSEMEM_STATIC if X86_32 1622 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1623 1624config ARCH_SPARSEMEM_DEFAULT 1625 def_bool y 1626 depends on X86_64 1627 1628config ARCH_SELECT_MEMORY_MODEL 1629 def_bool y 1630 depends on ARCH_SPARSEMEM_ENABLE 1631 1632config ARCH_MEMORY_PROBE 1633 bool "Enable sysfs memory/probe interface" 1634 depends on X86_64 && MEMORY_HOTPLUG 1635 help 1636 This option enables a sysfs memory/probe interface for testing. 1637 See Documentation/memory-hotplug.txt for more information. 1638 If you are unsure how to answer this question, answer N. 1639 1640config ARCH_PROC_KCORE_TEXT 1641 def_bool y 1642 depends on X86_64 && PROC_KCORE 1643 1644config ILLEGAL_POINTER_VALUE 1645 hex 1646 default 0 if X86_32 1647 default 0xdead000000000000 if X86_64 1648 1649config X86_PMEM_LEGACY_DEVICE 1650 bool 1651 1652config X86_PMEM_LEGACY 1653 tristate "Support non-standard NVDIMMs and ADR protected memory" 1654 depends on PHYS_ADDR_T_64BIT 1655 depends on BLK_DEV 1656 select X86_PMEM_LEGACY_DEVICE 1657 select LIBNVDIMM 1658 help 1659 Treat memory marked using the non-standard e820 type of 12 as used 1660 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1661 The kernel will offer these regions to the 'pmem' driver so 1662 they can be used for persistent storage. 1663 1664 Say Y if unsure. 1665 1666config HIGHPTE 1667 bool "Allocate 3rd-level pagetables from highmem" 1668 depends on HIGHMEM 1669 ---help--- 1670 The VM uses one page table entry for each page of physical memory. 1671 For systems with a lot of RAM, this can be wasteful of precious 1672 low memory. Setting this option will put user-space page table 1673 entries in high memory. 1674 1675config X86_CHECK_BIOS_CORRUPTION 1676 bool "Check for low memory corruption" 1677 ---help--- 1678 Periodically check for memory corruption in low memory, which 1679 is suspected to be caused by BIOS. Even when enabled in the 1680 configuration, it is disabled at runtime. Enable it by 1681 setting "memory_corruption_check=1" on the kernel command 1682 line. By default it scans the low 64k of memory every 60 1683 seconds; see the memory_corruption_check_size and 1684 memory_corruption_check_period parameters in 1685 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1686 1687 When enabled with the default parameters, this option has 1688 almost no overhead, as it reserves a relatively small amount 1689 of memory and scans it infrequently. It both detects corruption 1690 and prevents it from affecting the running system. 1691 1692 It is, however, intended as a diagnostic tool; if repeatable 1693 BIOS-originated corruption always affects the same memory, 1694 you can use memmap= to prevent the kernel from using that 1695 memory. 1696 1697config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1698 bool "Set the default setting of memory_corruption_check" 1699 depends on X86_CHECK_BIOS_CORRUPTION 1700 default y 1701 ---help--- 1702 Set whether the default state of memory_corruption_check is 1703 on or off. 1704 1705config X86_RESERVE_LOW 1706 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1707 default 64 1708 range 4 640 1709 ---help--- 1710 Specify the amount of low memory to reserve for the BIOS. 1711 1712 The first page contains BIOS data structures that the kernel 1713 must not use, so that page must always be reserved. 1714 1715 By default we reserve the first 64K of physical RAM, as a 1716 number of BIOSes are known to corrupt that memory range 1717 during events such as suspend/resume or monitor cable 1718 insertion, so it must not be used by the kernel. 1719 1720 You can set this to 4 if you are absolutely sure that you 1721 trust the BIOS to get all its memory reservations and usages 1722 right. If you know your BIOS have problems beyond the 1723 default 64K area, you can set this to 640 to avoid using the 1724 entire low memory range. 1725 1726 If you have doubts about the BIOS (e.g. suspend/resume does 1727 not work or there's kernel crashes after certain hardware 1728 hotplug events) then you might want to enable 1729 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1730 typical corruption patterns. 1731 1732 Leave this to the default value of 64 if you are unsure. 1733 1734config MATH_EMULATION 1735 bool 1736 depends on MODIFY_LDT_SYSCALL 1737 prompt "Math emulation" if X86_32 1738 ---help--- 1739 Linux can emulate a math coprocessor (used for floating point 1740 operations) if you don't have one. 486DX and Pentium processors have 1741 a math coprocessor built in, 486SX and 386 do not, unless you added 1742 a 487DX or 387, respectively. (The messages during boot time can 1743 give you some hints here ["man dmesg"].) Everyone needs either a 1744 coprocessor or this emulation. 1745 1746 If you don't have a math coprocessor, you need to say Y here; if you 1747 say Y here even though you have a coprocessor, the coprocessor will 1748 be used nevertheless. (This behavior can be changed with the kernel 1749 command line option "no387", which comes handy if your coprocessor 1750 is broken. Try "man bootparam" or see the documentation of your boot 1751 loader (lilo or loadlin) about how to pass options to the kernel at 1752 boot time.) This means that it is a good idea to say Y here if you 1753 intend to use this kernel on different machines. 1754 1755 More information about the internals of the Linux math coprocessor 1756 emulation can be found in <file:arch/x86/math-emu/README>. 1757 1758 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1759 kernel, it won't hurt. 1760 1761config MTRR 1762 def_bool y 1763 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1764 ---help--- 1765 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1766 the Memory Type Range Registers (MTRRs) may be used to control 1767 processor access to memory ranges. This is most useful if you have 1768 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1769 allows bus write transfers to be combined into a larger transfer 1770 before bursting over the PCI/AGP bus. This can increase performance 1771 of image write operations 2.5 times or more. Saying Y here creates a 1772 /proc/mtrr file which may be used to manipulate your processor's 1773 MTRRs. Typically the X server should use this. 1774 1775 This code has a reasonably generic interface so that similar 1776 control registers on other processors can be easily supported 1777 as well: 1778 1779 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1780 Registers (ARRs) which provide a similar functionality to MTRRs. For 1781 these, the ARRs are used to emulate the MTRRs. 1782 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1783 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1784 write-combining. All of these processors are supported by this code 1785 and it makes sense to say Y here if you have one of them. 1786 1787 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1788 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1789 can lead to all sorts of problems, so it's good to say Y here. 1790 1791 You can safely say Y even if your machine doesn't have MTRRs, you'll 1792 just add about 9 KB to your kernel. 1793 1794 See <file:Documentation/x86/mtrr.txt> for more information. 1795 1796config MTRR_SANITIZER 1797 def_bool y 1798 prompt "MTRR cleanup support" 1799 depends on MTRR 1800 ---help--- 1801 Convert MTRR layout from continuous to discrete, so X drivers can 1802 add writeback entries. 1803 1804 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1805 The largest mtrr entry size for a continuous block can be set with 1806 mtrr_chunk_size. 1807 1808 If unsure, say Y. 1809 1810config MTRR_SANITIZER_ENABLE_DEFAULT 1811 int "MTRR cleanup enable value (0-1)" 1812 range 0 1 1813 default "0" 1814 depends on MTRR_SANITIZER 1815 ---help--- 1816 Enable mtrr cleanup default value 1817 1818config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1819 int "MTRR cleanup spare reg num (0-7)" 1820 range 0 7 1821 default "1" 1822 depends on MTRR_SANITIZER 1823 ---help--- 1824 mtrr cleanup spare entries default, it can be changed via 1825 mtrr_spare_reg_nr=N on the kernel command line. 1826 1827config X86_PAT 1828 def_bool y 1829 prompt "x86 PAT support" if EXPERT 1830 depends on MTRR 1831 ---help--- 1832 Use PAT attributes to setup page level cache control. 1833 1834 PATs are the modern equivalents of MTRRs and are much more 1835 flexible than MTRRs. 1836 1837 Say N here if you see bootup problems (boot crash, boot hang, 1838 spontaneous reboots) or a non-working video driver. 1839 1840 If unsure, say Y. 1841 1842config ARCH_USES_PG_UNCACHED 1843 def_bool y 1844 depends on X86_PAT 1845 1846config ARCH_RANDOM 1847 def_bool y 1848 prompt "x86 architectural random number generator" if EXPERT 1849 ---help--- 1850 Enable the x86 architectural RDRAND instruction 1851 (Intel Bull Mountain technology) to generate random numbers. 1852 If supported, this is a high bandwidth, cryptographically 1853 secure hardware random number generator. 1854 1855config X86_SMAP 1856 def_bool y 1857 prompt "Supervisor Mode Access Prevention" if EXPERT 1858 ---help--- 1859 Supervisor Mode Access Prevention (SMAP) is a security 1860 feature in newer Intel processors. There is a small 1861 performance cost if this enabled and turned on; there is 1862 also a small increase in the kernel size if this is enabled. 1863 1864 If unsure, say Y. 1865 1866config X86_INTEL_UMIP 1867 def_bool y 1868 depends on CPU_SUP_INTEL 1869 prompt "Intel User Mode Instruction Prevention" if EXPERT 1870 ---help--- 1871 The User Mode Instruction Prevention (UMIP) is a security 1872 feature in newer Intel processors. If enabled, a general 1873 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1874 or STR instructions are executed in user mode. These instructions 1875 unnecessarily expose information about the hardware state. 1876 1877 The vast majority of applications do not use these instructions. 1878 For the very few that do, software emulation is provided in 1879 specific cases in protected and virtual-8086 modes. Emulated 1880 results are dummy. 1881 1882config X86_INTEL_MPX 1883 prompt "Intel MPX (Memory Protection Extensions)" 1884 def_bool n 1885 # Note: only available in 64-bit mode due to VMA flags shortage 1886 depends on CPU_SUP_INTEL && X86_64 1887 select ARCH_USES_HIGH_VMA_FLAGS 1888 ---help--- 1889 MPX provides hardware features that can be used in 1890 conjunction with compiler-instrumented code to check 1891 memory references. It is designed to detect buffer 1892 overflow or underflow bugs. 1893 1894 This option enables running applications which are 1895 instrumented or otherwise use MPX. It does not use MPX 1896 itself inside the kernel or to protect the kernel 1897 against bad memory references. 1898 1899 Enabling this option will make the kernel larger: 1900 ~8k of kernel text and 36 bytes of data on a 64-bit 1901 defconfig. It adds a long to the 'mm_struct' which 1902 will increase the kernel memory overhead of each 1903 process and adds some branches to paths used during 1904 exec() and munmap(). 1905 1906 For details, see Documentation/x86/intel_mpx.txt 1907 1908 If unsure, say N. 1909 1910config X86_INTEL_MEMORY_PROTECTION_KEYS 1911 prompt "Intel Memory Protection Keys" 1912 def_bool y 1913 # Note: only available in 64-bit mode 1914 depends on CPU_SUP_INTEL && X86_64 1915 select ARCH_USES_HIGH_VMA_FLAGS 1916 select ARCH_HAS_PKEYS 1917 ---help--- 1918 Memory Protection Keys provides a mechanism for enforcing 1919 page-based protections, but without requiring modification of the 1920 page tables when an application changes protection domains. 1921 1922 For details, see Documentation/x86/protection-keys.txt 1923 1924 If unsure, say y. 1925 1926config EFI 1927 bool "EFI runtime service support" 1928 depends on ACPI 1929 select UCS2_STRING 1930 select EFI_RUNTIME_WRAPPERS 1931 ---help--- 1932 This enables the kernel to use EFI runtime services that are 1933 available (such as the EFI variable services). 1934 1935 This option is only useful on systems that have EFI firmware. 1936 In addition, you should use the latest ELILO loader available 1937 at <http://elilo.sourceforge.net> in order to take advantage 1938 of EFI runtime services. However, even with this option, the 1939 resultant kernel should continue to boot on existing non-EFI 1940 platforms. 1941 1942config EFI_STUB 1943 bool "EFI stub support" 1944 depends on EFI && !X86_USE_3DNOW 1945 select RELOCATABLE 1946 ---help--- 1947 This kernel feature allows a bzImage to be loaded directly 1948 by EFI firmware without the use of a bootloader. 1949 1950 See Documentation/efi-stub.txt for more information. 1951 1952config EFI_MIXED 1953 bool "EFI mixed-mode support" 1954 depends on EFI_STUB && X86_64 1955 ---help--- 1956 Enabling this feature allows a 64-bit kernel to be booted 1957 on a 32-bit firmware, provided that your CPU supports 64-bit 1958 mode. 1959 1960 Note that it is not possible to boot a mixed-mode enabled 1961 kernel via the EFI boot stub - a bootloader that supports 1962 the EFI handover protocol must be used. 1963 1964 If unsure, say N. 1965 1966config SECCOMP 1967 def_bool y 1968 prompt "Enable seccomp to safely compute untrusted bytecode" 1969 ---help--- 1970 This kernel feature is useful for number crunching applications 1971 that may need to compute untrusted bytecode during their 1972 execution. By using pipes or other transports made available to 1973 the process as file descriptors supporting the read/write 1974 syscalls, it's possible to isolate those applications in 1975 their own address space using seccomp. Once seccomp is 1976 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1977 and the task is only allowed to execute a few safe syscalls 1978 defined by each seccomp mode. 1979 1980 If unsure, say Y. Only embedded should say N here. 1981 1982source kernel/Kconfig.hz 1983 1984config KEXEC 1985 bool "kexec system call" 1986 select KEXEC_CORE 1987 ---help--- 1988 kexec is a system call that implements the ability to shutdown your 1989 current kernel, and to start another kernel. It is like a reboot 1990 but it is independent of the system firmware. And like a reboot 1991 you can start any kernel with it, not just Linux. 1992 1993 The name comes from the similarity to the exec system call. 1994 1995 It is an ongoing process to be certain the hardware in a machine 1996 is properly shutdown, so do not be surprised if this code does not 1997 initially work for you. As of this writing the exact hardware 1998 interface is strongly in flux, so no good recommendation can be 1999 made. 2000 2001config KEXEC_FILE 2002 bool "kexec file based system call" 2003 select KEXEC_CORE 2004 select BUILD_BIN2C 2005 depends on X86_64 2006 depends on CRYPTO=y 2007 depends on CRYPTO_SHA256=y 2008 ---help--- 2009 This is new version of kexec system call. This system call is 2010 file based and takes file descriptors as system call argument 2011 for kernel and initramfs as opposed to list of segments as 2012 accepted by previous system call. 2013 2014config ARCH_HAS_KEXEC_PURGATORY 2015 def_bool KEXEC_FILE 2016 2017config KEXEC_VERIFY_SIG 2018 bool "Verify kernel signature during kexec_file_load() syscall" 2019 depends on KEXEC_FILE 2020 ---help--- 2021 This option makes kernel signature verification mandatory for 2022 the kexec_file_load() syscall. 2023 2024 In addition to that option, you need to enable signature 2025 verification for the corresponding kernel image type being 2026 loaded in order for this to work. 2027 2028config KEXEC_BZIMAGE_VERIFY_SIG 2029 bool "Enable bzImage signature verification support" 2030 depends on KEXEC_VERIFY_SIG 2031 depends on SIGNED_PE_FILE_VERIFICATION 2032 select SYSTEM_TRUSTED_KEYRING 2033 ---help--- 2034 Enable bzImage signature verification support. 2035 2036config CRASH_DUMP 2037 bool "kernel crash dumps" 2038 depends on X86_64 || (X86_32 && HIGHMEM) 2039 ---help--- 2040 Generate crash dump after being started by kexec. 2041 This should be normally only set in special crash dump kernels 2042 which are loaded in the main kernel with kexec-tools into 2043 a specially reserved region and then later executed after 2044 a crash by kdump/kexec. The crash dump kernel must be compiled 2045 to a memory address not used by the main kernel or BIOS using 2046 PHYSICAL_START, or it must be built as a relocatable image 2047 (CONFIG_RELOCATABLE=y). 2048 For more details see Documentation/kdump/kdump.txt 2049 2050config KEXEC_JUMP 2051 bool "kexec jump" 2052 depends on KEXEC && HIBERNATION 2053 ---help--- 2054 Jump between original kernel and kexeced kernel and invoke 2055 code in physical address mode via KEXEC 2056 2057config PHYSICAL_START 2058 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2059 default "0x1000000" 2060 ---help--- 2061 This gives the physical address where the kernel is loaded. 2062 2063 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2064 bzImage will decompress itself to above physical address and 2065 run from there. Otherwise, bzImage will run from the address where 2066 it has been loaded by the boot loader and will ignore above physical 2067 address. 2068 2069 In normal kdump cases one does not have to set/change this option 2070 as now bzImage can be compiled as a completely relocatable image 2071 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2072 address. This option is mainly useful for the folks who don't want 2073 to use a bzImage for capturing the crash dump and want to use a 2074 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2075 to be specifically compiled to run from a specific memory area 2076 (normally a reserved region) and this option comes handy. 2077 2078 So if you are using bzImage for capturing the crash dump, 2079 leave the value here unchanged to 0x1000000 and set 2080 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2081 for capturing the crash dump change this value to start of 2082 the reserved region. In other words, it can be set based on 2083 the "X" value as specified in the "crashkernel=YM@XM" 2084 command line boot parameter passed to the panic-ed 2085 kernel. Please take a look at Documentation/kdump/kdump.txt 2086 for more details about crash dumps. 2087 2088 Usage of bzImage for capturing the crash dump is recommended as 2089 one does not have to build two kernels. Same kernel can be used 2090 as production kernel and capture kernel. Above option should have 2091 gone away after relocatable bzImage support is introduced. But it 2092 is present because there are users out there who continue to use 2093 vmlinux for dump capture. This option should go away down the 2094 line. 2095 2096 Don't change this unless you know what you are doing. 2097 2098config RELOCATABLE 2099 bool "Build a relocatable kernel" 2100 default y 2101 ---help--- 2102 This builds a kernel image that retains relocation information 2103 so it can be loaded someplace besides the default 1MB. 2104 The relocations tend to make the kernel binary about 10% larger, 2105 but are discarded at runtime. 2106 2107 One use is for the kexec on panic case where the recovery kernel 2108 must live at a different physical address than the primary 2109 kernel. 2110 2111 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2112 it has been loaded at and the compile time physical address 2113 (CONFIG_PHYSICAL_START) is used as the minimum location. 2114 2115config RANDOMIZE_BASE 2116 bool "Randomize the address of the kernel image (KASLR)" 2117 depends on RELOCATABLE 2118 default y 2119 ---help--- 2120 In support of Kernel Address Space Layout Randomization (KASLR), 2121 this randomizes the physical address at which the kernel image 2122 is decompressed and the virtual address where the kernel 2123 image is mapped, as a security feature that deters exploit 2124 attempts relying on knowledge of the location of kernel 2125 code internals. 2126 2127 On 64-bit, the kernel physical and virtual addresses are 2128 randomized separately. The physical address will be anywhere 2129 between 16MB and the top of physical memory (up to 64TB). The 2130 virtual address will be randomized from 16MB up to 1GB (9 bits 2131 of entropy). Note that this also reduces the memory space 2132 available to kernel modules from 1.5GB to 1GB. 2133 2134 On 32-bit, the kernel physical and virtual addresses are 2135 randomized together. They will be randomized from 16MB up to 2136 512MB (8 bits of entropy). 2137 2138 Entropy is generated using the RDRAND instruction if it is 2139 supported. If RDTSC is supported, its value is mixed into 2140 the entropy pool as well. If neither RDRAND nor RDTSC are 2141 supported, then entropy is read from the i8254 timer. The 2142 usable entropy is limited by the kernel being built using 2143 2GB addressing, and that PHYSICAL_ALIGN must be at a 2144 minimum of 2MB. As a result, only 10 bits of entropy are 2145 theoretically possible, but the implementations are further 2146 limited due to memory layouts. 2147 2148 If unsure, say Y. 2149 2150# Relocation on x86 needs some additional build support 2151config X86_NEED_RELOCS 2152 def_bool y 2153 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2154 2155config PHYSICAL_ALIGN 2156 hex "Alignment value to which kernel should be aligned" 2157 default "0x200000" 2158 range 0x2000 0x1000000 if X86_32 2159 range 0x200000 0x1000000 if X86_64 2160 ---help--- 2161 This value puts the alignment restrictions on physical address 2162 where kernel is loaded and run from. Kernel is compiled for an 2163 address which meets above alignment restriction. 2164 2165 If bootloader loads the kernel at a non-aligned address and 2166 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2167 address aligned to above value and run from there. 2168 2169 If bootloader loads the kernel at a non-aligned address and 2170 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2171 load address and decompress itself to the address it has been 2172 compiled for and run from there. The address for which kernel is 2173 compiled already meets above alignment restrictions. Hence the 2174 end result is that kernel runs from a physical address meeting 2175 above alignment restrictions. 2176 2177 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2178 this value must be a multiple of 0x200000. 2179 2180 Don't change this unless you know what you are doing. 2181 2182config DYNAMIC_MEMORY_LAYOUT 2183 bool 2184 ---help--- 2185 This option makes base addresses of vmalloc and vmemmap as well as 2186 __PAGE_OFFSET movable during boot. 2187 2188config RANDOMIZE_MEMORY 2189 bool "Randomize the kernel memory sections" 2190 depends on X86_64 2191 depends on RANDOMIZE_BASE 2192 select DYNAMIC_MEMORY_LAYOUT 2193 default RANDOMIZE_BASE 2194 ---help--- 2195 Randomizes the base virtual address of kernel memory sections 2196 (physical memory mapping, vmalloc & vmemmap). This security feature 2197 makes exploits relying on predictable memory locations less reliable. 2198 2199 The order of allocations remains unchanged. Entropy is generated in 2200 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2201 configuration have in average 30,000 different possible virtual 2202 addresses for each memory section. 2203 2204 If unsure, say Y. 2205 2206config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2207 hex "Physical memory mapping padding" if EXPERT 2208 depends on RANDOMIZE_MEMORY 2209 default "0xa" if MEMORY_HOTPLUG 2210 default "0x0" 2211 range 0x1 0x40 if MEMORY_HOTPLUG 2212 range 0x0 0x40 2213 ---help--- 2214 Define the padding in terabytes added to the existing physical 2215 memory size during kernel memory randomization. It is useful 2216 for memory hotplug support but reduces the entropy available for 2217 address randomization. 2218 2219 If unsure, leave at the default value. 2220 2221config HOTPLUG_CPU 2222 bool "Support for hot-pluggable CPUs" 2223 depends on SMP 2224 ---help--- 2225 Say Y here to allow turning CPUs off and on. CPUs can be 2226 controlled through /sys/devices/system/cpu. 2227 ( Note: power management support will enable this option 2228 automatically on SMP systems. ) 2229 Say N if you want to disable CPU hotplug. 2230 2231config BOOTPARAM_HOTPLUG_CPU0 2232 bool "Set default setting of cpu0_hotpluggable" 2233 depends on HOTPLUG_CPU 2234 ---help--- 2235 Set whether default state of cpu0_hotpluggable is on or off. 2236 2237 Say Y here to enable CPU0 hotplug by default. If this switch 2238 is turned on, there is no need to give cpu0_hotplug kernel 2239 parameter and the CPU0 hotplug feature is enabled by default. 2240 2241 Please note: there are two known CPU0 dependencies if you want 2242 to enable the CPU0 hotplug feature either by this switch or by 2243 cpu0_hotplug kernel parameter. 2244 2245 First, resume from hibernate or suspend always starts from CPU0. 2246 So hibernate and suspend are prevented if CPU0 is offline. 2247 2248 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2249 offline if any interrupt can not migrate out of CPU0. There may 2250 be other CPU0 dependencies. 2251 2252 Please make sure the dependencies are under your control before 2253 you enable this feature. 2254 2255 Say N if you don't want to enable CPU0 hotplug feature by default. 2256 You still can enable the CPU0 hotplug feature at boot by kernel 2257 parameter cpu0_hotplug. 2258 2259config DEBUG_HOTPLUG_CPU0 2260 def_bool n 2261 prompt "Debug CPU0 hotplug" 2262 depends on HOTPLUG_CPU 2263 ---help--- 2264 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2265 soon as possible and boots up userspace with CPU0 offlined. User 2266 can online CPU0 back after boot time. 2267 2268 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2269 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2270 compilation or giving cpu0_hotplug kernel parameter at boot. 2271 2272 If unsure, say N. 2273 2274config COMPAT_VDSO 2275 def_bool n 2276 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2277 depends on COMPAT_32 2278 ---help--- 2279 Certain buggy versions of glibc will crash if they are 2280 presented with a 32-bit vDSO that is not mapped at the address 2281 indicated in its segment table. 2282 2283 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2284 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2285 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2286 the only released version with the bug, but OpenSUSE 9 2287 contains a buggy "glibc 2.3.2". 2288 2289 The symptom of the bug is that everything crashes on startup, saying: 2290 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2291 2292 Saying Y here changes the default value of the vdso32 boot 2293 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2294 This works around the glibc bug but hurts performance. 2295 2296 If unsure, say N: if you are compiling your own kernel, you 2297 are unlikely to be using a buggy version of glibc. 2298 2299choice 2300 prompt "vsyscall table for legacy applications" 2301 depends on X86_64 2302 default LEGACY_VSYSCALL_EMULATE 2303 help 2304 Legacy user code that does not know how to find the vDSO expects 2305 to be able to issue three syscalls by calling fixed addresses in 2306 kernel space. Since this location is not randomized with ASLR, 2307 it can be used to assist security vulnerability exploitation. 2308 2309 This setting can be changed at boot time via the kernel command 2310 line parameter vsyscall=[emulate|none]. 2311 2312 On a system with recent enough glibc (2.14 or newer) and no 2313 static binaries, you can say None without a performance penalty 2314 to improve security. 2315 2316 If unsure, select "Emulate". 2317 2318 config LEGACY_VSYSCALL_EMULATE 2319 bool "Emulate" 2320 help 2321 The kernel traps and emulates calls into the fixed 2322 vsyscall address mapping. This makes the mapping 2323 non-executable, but it still contains known contents, 2324 which could be used in certain rare security vulnerability 2325 exploits. This configuration is recommended when userspace 2326 still uses the vsyscall area. 2327 2328 config LEGACY_VSYSCALL_NONE 2329 bool "None" 2330 help 2331 There will be no vsyscall mapping at all. This will 2332 eliminate any risk of ASLR bypass due to the vsyscall 2333 fixed address mapping. Attempts to use the vsyscalls 2334 will be reported to dmesg, so that either old or 2335 malicious userspace programs can be identified. 2336 2337endchoice 2338 2339config CMDLINE_BOOL 2340 bool "Built-in kernel command line" 2341 ---help--- 2342 Allow for specifying boot arguments to the kernel at 2343 build time. On some systems (e.g. embedded ones), it is 2344 necessary or convenient to provide some or all of the 2345 kernel boot arguments with the kernel itself (that is, 2346 to not rely on the boot loader to provide them.) 2347 2348 To compile command line arguments into the kernel, 2349 set this option to 'Y', then fill in the 2350 boot arguments in CONFIG_CMDLINE. 2351 2352 Systems with fully functional boot loaders (i.e. non-embedded) 2353 should leave this option set to 'N'. 2354 2355config CMDLINE 2356 string "Built-in kernel command string" 2357 depends on CMDLINE_BOOL 2358 default "" 2359 ---help--- 2360 Enter arguments here that should be compiled into the kernel 2361 image and used at boot time. If the boot loader provides a 2362 command line at boot time, it is appended to this string to 2363 form the full kernel command line, when the system boots. 2364 2365 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2366 change this behavior. 2367 2368 In most cases, the command line (whether built-in or provided 2369 by the boot loader) should specify the device for the root 2370 file system. 2371 2372config CMDLINE_OVERRIDE 2373 bool "Built-in command line overrides boot loader arguments" 2374 depends on CMDLINE_BOOL 2375 ---help--- 2376 Set this option to 'Y' to have the kernel ignore the boot loader 2377 command line, and use ONLY the built-in command line. 2378 2379 This is used to work around broken boot loaders. This should 2380 be set to 'N' under normal conditions. 2381 2382config MODIFY_LDT_SYSCALL 2383 bool "Enable the LDT (local descriptor table)" if EXPERT 2384 default y 2385 ---help--- 2386 Linux can allow user programs to install a per-process x86 2387 Local Descriptor Table (LDT) using the modify_ldt(2) system 2388 call. This is required to run 16-bit or segmented code such as 2389 DOSEMU or some Wine programs. It is also used by some very old 2390 threading libraries. 2391 2392 Enabling this feature adds a small amount of overhead to 2393 context switches and increases the low-level kernel attack 2394 surface. Disabling it removes the modify_ldt(2) system call. 2395 2396 Saying 'N' here may make sense for embedded or server kernels. 2397 2398source "kernel/livepatch/Kconfig" 2399 2400endmenu 2401 2402config ARCH_HAS_ADD_PAGES 2403 def_bool y 2404 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2405 2406config ARCH_ENABLE_MEMORY_HOTPLUG 2407 def_bool y 2408 depends on X86_64 || (X86_32 && HIGHMEM) 2409 2410config ARCH_ENABLE_MEMORY_HOTREMOVE 2411 def_bool y 2412 depends on MEMORY_HOTPLUG 2413 2414config USE_PERCPU_NUMA_NODE_ID 2415 def_bool y 2416 depends on NUMA 2417 2418config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2419 def_bool y 2420 depends on X86_64 || X86_PAE 2421 2422config ARCH_ENABLE_HUGEPAGE_MIGRATION 2423 def_bool y 2424 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2425 2426config ARCH_ENABLE_THP_MIGRATION 2427 def_bool y 2428 depends on X86_64 && TRANSPARENT_HUGEPAGE 2429 2430menu "Power management and ACPI options" 2431 2432config ARCH_HIBERNATION_HEADER 2433 def_bool y 2434 depends on HIBERNATION 2435 2436source "kernel/power/Kconfig" 2437 2438source "drivers/acpi/Kconfig" 2439 2440source "drivers/sfi/Kconfig" 2441 2442config X86_APM_BOOT 2443 def_bool y 2444 depends on APM 2445 2446menuconfig APM 2447 tristate "APM (Advanced Power Management) BIOS support" 2448 depends on X86_32 && PM_SLEEP 2449 ---help--- 2450 APM is a BIOS specification for saving power using several different 2451 techniques. This is mostly useful for battery powered laptops with 2452 APM compliant BIOSes. If you say Y here, the system time will be 2453 reset after a RESUME operation, the /proc/apm device will provide 2454 battery status information, and user-space programs will receive 2455 notification of APM "events" (e.g. battery status change). 2456 2457 If you select "Y" here, you can disable actual use of the APM 2458 BIOS by passing the "apm=off" option to the kernel at boot time. 2459 2460 Note that the APM support is almost completely disabled for 2461 machines with more than one CPU. 2462 2463 In order to use APM, you will need supporting software. For location 2464 and more information, read <file:Documentation/power/apm-acpi.txt> 2465 and the Battery Powered Linux mini-HOWTO, available from 2466 <http://www.tldp.org/docs.html#howto>. 2467 2468 This driver does not spin down disk drives (see the hdparm(8) 2469 manpage ("man 8 hdparm") for that), and it doesn't turn off 2470 VESA-compliant "green" monitors. 2471 2472 This driver does not support the TI 4000M TravelMate and the ACER 2473 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2474 desktop machines also don't have compliant BIOSes, and this driver 2475 may cause those machines to panic during the boot phase. 2476 2477 Generally, if you don't have a battery in your machine, there isn't 2478 much point in using this driver and you should say N. If you get 2479 random kernel OOPSes or reboots that don't seem to be related to 2480 anything, try disabling/enabling this option (or disabling/enabling 2481 APM in your BIOS). 2482 2483 Some other things you should try when experiencing seemingly random, 2484 "weird" problems: 2485 2486 1) make sure that you have enough swap space and that it is 2487 enabled. 2488 2) pass the "no-hlt" option to the kernel 2489 3) switch on floating point emulation in the kernel and pass 2490 the "no387" option to the kernel 2491 4) pass the "floppy=nodma" option to the kernel 2492 5) pass the "mem=4M" option to the kernel (thereby disabling 2493 all but the first 4 MB of RAM) 2494 6) make sure that the CPU is not over clocked. 2495 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2496 8) disable the cache from your BIOS settings 2497 9) install a fan for the video card or exchange video RAM 2498 10) install a better fan for the CPU 2499 11) exchange RAM chips 2500 12) exchange the motherboard. 2501 2502 To compile this driver as a module, choose M here: the 2503 module will be called apm. 2504 2505if APM 2506 2507config APM_IGNORE_USER_SUSPEND 2508 bool "Ignore USER SUSPEND" 2509 ---help--- 2510 This option will ignore USER SUSPEND requests. On machines with a 2511 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2512 series notebooks, it is necessary to say Y because of a BIOS bug. 2513 2514config APM_DO_ENABLE 2515 bool "Enable PM at boot time" 2516 ---help--- 2517 Enable APM features at boot time. From page 36 of the APM BIOS 2518 specification: "When disabled, the APM BIOS does not automatically 2519 power manage devices, enter the Standby State, enter the Suspend 2520 State, or take power saving steps in response to CPU Idle calls." 2521 This driver will make CPU Idle calls when Linux is idle (unless this 2522 feature is turned off -- see "Do CPU IDLE calls", below). This 2523 should always save battery power, but more complicated APM features 2524 will be dependent on your BIOS implementation. You may need to turn 2525 this option off if your computer hangs at boot time when using APM 2526 support, or if it beeps continuously instead of suspending. Turn 2527 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2528 T400CDT. This is off by default since most machines do fine without 2529 this feature. 2530 2531config APM_CPU_IDLE 2532 depends on CPU_IDLE 2533 bool "Make CPU Idle calls when idle" 2534 ---help--- 2535 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2536 On some machines, this can activate improved power savings, such as 2537 a slowed CPU clock rate, when the machine is idle. These idle calls 2538 are made after the idle loop has run for some length of time (e.g., 2539 333 mS). On some machines, this will cause a hang at boot time or 2540 whenever the CPU becomes idle. (On machines with more than one CPU, 2541 this option does nothing.) 2542 2543config APM_DISPLAY_BLANK 2544 bool "Enable console blanking using APM" 2545 ---help--- 2546 Enable console blanking using the APM. Some laptops can use this to 2547 turn off the LCD backlight when the screen blanker of the Linux 2548 virtual console blanks the screen. Note that this is only used by 2549 the virtual console screen blanker, and won't turn off the backlight 2550 when using the X Window system. This also doesn't have anything to 2551 do with your VESA-compliant power-saving monitor. Further, this 2552 option doesn't work for all laptops -- it might not turn off your 2553 backlight at all, or it might print a lot of errors to the console, 2554 especially if you are using gpm. 2555 2556config APM_ALLOW_INTS 2557 bool "Allow interrupts during APM BIOS calls" 2558 ---help--- 2559 Normally we disable external interrupts while we are making calls to 2560 the APM BIOS as a measure to lessen the effects of a badly behaving 2561 BIOS implementation. The BIOS should reenable interrupts if it 2562 needs to. Unfortunately, some BIOSes do not -- especially those in 2563 many of the newer IBM Thinkpads. If you experience hangs when you 2564 suspend, try setting this to Y. Otherwise, say N. 2565 2566endif # APM 2567 2568source "drivers/cpufreq/Kconfig" 2569 2570source "drivers/cpuidle/Kconfig" 2571 2572source "drivers/idle/Kconfig" 2573 2574endmenu 2575 2576 2577menu "Bus options (PCI etc.)" 2578 2579config PCI 2580 bool "PCI support" 2581 default y 2582 ---help--- 2583 Find out whether you have a PCI motherboard. PCI is the name of a 2584 bus system, i.e. the way the CPU talks to the other stuff inside 2585 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2586 VESA. If you have PCI, say Y, otherwise N. 2587 2588choice 2589 prompt "PCI access mode" 2590 depends on X86_32 && PCI 2591 default PCI_GOANY 2592 ---help--- 2593 On PCI systems, the BIOS can be used to detect the PCI devices and 2594 determine their configuration. However, some old PCI motherboards 2595 have BIOS bugs and may crash if this is done. Also, some embedded 2596 PCI-based systems don't have any BIOS at all. Linux can also try to 2597 detect the PCI hardware directly without using the BIOS. 2598 2599 With this option, you can specify how Linux should detect the 2600 PCI devices. If you choose "BIOS", the BIOS will be used, 2601 if you choose "Direct", the BIOS won't be used, and if you 2602 choose "MMConfig", then PCI Express MMCONFIG will be used. 2603 If you choose "Any", the kernel will try MMCONFIG, then the 2604 direct access method and falls back to the BIOS if that doesn't 2605 work. If unsure, go with the default, which is "Any". 2606 2607config PCI_GOBIOS 2608 bool "BIOS" 2609 2610config PCI_GOMMCONFIG 2611 bool "MMConfig" 2612 2613config PCI_GODIRECT 2614 bool "Direct" 2615 2616config PCI_GOOLPC 2617 bool "OLPC XO-1" 2618 depends on OLPC 2619 2620config PCI_GOANY 2621 bool "Any" 2622 2623endchoice 2624 2625config PCI_BIOS 2626 def_bool y 2627 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2628 2629# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2630config PCI_DIRECT 2631 def_bool y 2632 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2633 2634config PCI_MMCONFIG 2635 bool "Support mmconfig PCI config space access" if X86_64 2636 default y 2637 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2638 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2639 2640config PCI_OLPC 2641 def_bool y 2642 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2643 2644config PCI_XEN 2645 def_bool y 2646 depends on PCI && XEN 2647 select SWIOTLB_XEN 2648 2649config PCI_DOMAINS 2650 def_bool y 2651 depends on PCI 2652 2653config MMCONF_FAM10H 2654 def_bool y 2655 depends on X86_64 && PCI_MMCONFIG && ACPI 2656 2657config PCI_CNB20LE_QUIRK 2658 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2659 depends on PCI 2660 help 2661 Read the PCI windows out of the CNB20LE host bridge. This allows 2662 PCI hotplug to work on systems with the CNB20LE chipset which do 2663 not have ACPI. 2664 2665 There's no public spec for this chipset, and this functionality 2666 is known to be incomplete. 2667 2668 You should say N unless you know you need this. 2669 2670source "drivers/pci/Kconfig" 2671 2672config ISA_BUS 2673 bool "ISA bus support on modern systems" if EXPERT 2674 help 2675 Expose ISA bus device drivers and options available for selection and 2676 configuration. Enable this option if your target machine has an ISA 2677 bus. ISA is an older system, displaced by PCI and newer bus 2678 architectures -- if your target machine is modern, it probably does 2679 not have an ISA bus. 2680 2681 If unsure, say N. 2682 2683# x86_64 have no ISA slots, but can have ISA-style DMA. 2684config ISA_DMA_API 2685 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2686 default y 2687 help 2688 Enables ISA-style DMA support for devices requiring such controllers. 2689 If unsure, say Y. 2690 2691if X86_32 2692 2693config ISA 2694 bool "ISA support" 2695 ---help--- 2696 Find out whether you have ISA slots on your motherboard. ISA is the 2697 name of a bus system, i.e. the way the CPU talks to the other stuff 2698 inside your box. Other bus systems are PCI, EISA, MicroChannel 2699 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2700 newer boards don't support it. If you have ISA, say Y, otherwise N. 2701 2702config EISA 2703 bool "EISA support" 2704 depends on ISA 2705 ---help--- 2706 The Extended Industry Standard Architecture (EISA) bus was 2707 developed as an open alternative to the IBM MicroChannel bus. 2708 2709 The EISA bus provided some of the features of the IBM MicroChannel 2710 bus while maintaining backward compatibility with cards made for 2711 the older ISA bus. The EISA bus saw limited use between 1988 and 2712 1995 when it was made obsolete by the PCI bus. 2713 2714 Say Y here if you are building a kernel for an EISA-based machine. 2715 2716 Otherwise, say N. 2717 2718source "drivers/eisa/Kconfig" 2719 2720config SCx200 2721 tristate "NatSemi SCx200 support" 2722 ---help--- 2723 This provides basic support for National Semiconductor's 2724 (now AMD's) Geode processors. The driver probes for the 2725 PCI-IDs of several on-chip devices, so its a good dependency 2726 for other scx200_* drivers. 2727 2728 If compiled as a module, the driver is named scx200. 2729 2730config SCx200HR_TIMER 2731 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2732 depends on SCx200 2733 default y 2734 ---help--- 2735 This driver provides a clocksource built upon the on-chip 2736 27MHz high-resolution timer. Its also a workaround for 2737 NSC Geode SC-1100's buggy TSC, which loses time when the 2738 processor goes idle (as is done by the scheduler). The 2739 other workaround is idle=poll boot option. 2740 2741config OLPC 2742 bool "One Laptop Per Child support" 2743 depends on !X86_PAE 2744 select GPIOLIB 2745 select OF 2746 select OF_PROMTREE 2747 select IRQ_DOMAIN 2748 ---help--- 2749 Add support for detecting the unique features of the OLPC 2750 XO hardware. 2751 2752config OLPC_XO1_PM 2753 bool "OLPC XO-1 Power Management" 2754 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2755 ---help--- 2756 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2757 2758config OLPC_XO1_RTC 2759 bool "OLPC XO-1 Real Time Clock" 2760 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2761 ---help--- 2762 Add support for the XO-1 real time clock, which can be used as a 2763 programmable wakeup source. 2764 2765config OLPC_XO1_SCI 2766 bool "OLPC XO-1 SCI extras" 2767 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2768 depends on INPUT=y 2769 select POWER_SUPPLY 2770 ---help--- 2771 Add support for SCI-based features of the OLPC XO-1 laptop: 2772 - EC-driven system wakeups 2773 - Power button 2774 - Ebook switch 2775 - Lid switch 2776 - AC adapter status updates 2777 - Battery status updates 2778 2779config OLPC_XO15_SCI 2780 bool "OLPC XO-1.5 SCI extras" 2781 depends on OLPC && ACPI 2782 select POWER_SUPPLY 2783 ---help--- 2784 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2785 - EC-driven system wakeups 2786 - AC adapter status updates 2787 - Battery status updates 2788 2789config ALIX 2790 bool "PCEngines ALIX System Support (LED setup)" 2791 select GPIOLIB 2792 ---help--- 2793 This option enables system support for the PCEngines ALIX. 2794 At present this just sets up LEDs for GPIO control on 2795 ALIX2/3/6 boards. However, other system specific setup should 2796 get added here. 2797 2798 Note: You must still enable the drivers for GPIO and LED support 2799 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2800 2801 Note: You have to set alix.force=1 for boards with Award BIOS. 2802 2803config NET5501 2804 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2805 select GPIOLIB 2806 ---help--- 2807 This option enables system support for the Soekris Engineering net5501. 2808 2809config GEOS 2810 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2811 select GPIOLIB 2812 depends on DMI 2813 ---help--- 2814 This option enables system support for the Traverse Technologies GEOS. 2815 2816config TS5500 2817 bool "Technologic Systems TS-5500 platform support" 2818 depends on MELAN 2819 select CHECK_SIGNATURE 2820 select NEW_LEDS 2821 select LEDS_CLASS 2822 ---help--- 2823 This option enables system support for the Technologic Systems TS-5500. 2824 2825endif # X86_32 2826 2827config AMD_NB 2828 def_bool y 2829 depends on CPU_SUP_AMD && PCI 2830 2831source "drivers/pcmcia/Kconfig" 2832 2833config RAPIDIO 2834 tristate "RapidIO support" 2835 depends on PCI 2836 help 2837 If enabled this option will include drivers and the core 2838 infrastructure code to support RapidIO interconnect devices. 2839 2840source "drivers/rapidio/Kconfig" 2841 2842config X86_SYSFB 2843 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2844 help 2845 Firmwares often provide initial graphics framebuffers so the BIOS, 2846 bootloader or kernel can show basic video-output during boot for 2847 user-guidance and debugging. Historically, x86 used the VESA BIOS 2848 Extensions and EFI-framebuffers for this, which are mostly limited 2849 to x86. 2850 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2851 framebuffers so the new generic system-framebuffer drivers can be 2852 used on x86. If the framebuffer is not compatible with the generic 2853 modes, it is advertised as fallback platform framebuffer so legacy 2854 drivers like efifb, vesafb and uvesafb can pick it up. 2855 If this option is not selected, all system framebuffers are always 2856 marked as fallback platform framebuffers as usual. 2857 2858 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2859 not be able to pick up generic system framebuffers if this option 2860 is selected. You are highly encouraged to enable simplefb as 2861 replacement if you select this option. simplefb can correctly deal 2862 with generic system framebuffers. But you should still keep vesafb 2863 and others enabled as fallback if a system framebuffer is 2864 incompatible with simplefb. 2865 2866 If unsure, say Y. 2867 2868endmenu 2869 2870 2871menu "Binary Emulations" 2872 2873config IA32_EMULATION 2874 bool "IA32 Emulation" 2875 depends on X86_64 2876 select ARCH_WANT_OLD_COMPAT_IPC 2877 select BINFMT_ELF 2878 select COMPAT_BINFMT_ELF 2879 select COMPAT_OLD_SIGACTION 2880 ---help--- 2881 Include code to run legacy 32-bit programs under a 2882 64-bit kernel. You should likely turn this on, unless you're 2883 100% sure that you don't have any 32-bit programs left. 2884 2885config IA32_AOUT 2886 tristate "IA32 a.out support" 2887 depends on IA32_EMULATION 2888 ---help--- 2889 Support old a.out binaries in the 32bit emulation. 2890 2891config X86_X32 2892 bool "x32 ABI for 64-bit mode" 2893 depends on X86_64 2894 ---help--- 2895 Include code to run binaries for the x32 native 32-bit ABI 2896 for 64-bit processors. An x32 process gets access to the 2897 full 64-bit register file and wide data path while leaving 2898 pointers at 32 bits for smaller memory footprint. 2899 2900 You will need a recent binutils (2.22 or later) with 2901 elf32_x86_64 support enabled to compile a kernel with this 2902 option set. 2903 2904config COMPAT_32 2905 def_bool y 2906 depends on IA32_EMULATION || X86_32 2907 select HAVE_UID16 2908 select OLD_SIGSUSPEND3 2909 2910config COMPAT 2911 def_bool y 2912 depends on IA32_EMULATION || X86_X32 2913 2914if COMPAT 2915config COMPAT_FOR_U64_ALIGNMENT 2916 def_bool y 2917 2918config SYSVIPC_COMPAT 2919 def_bool y 2920 depends on SYSVIPC 2921endif 2922 2923endmenu 2924 2925 2926config HAVE_ATOMIC_IOMAP 2927 def_bool y 2928 depends on X86_32 2929 2930config X86_DEV_DMA_OPS 2931 bool 2932 depends on X86_64 || STA2X11 2933 2934config X86_DMA_REMAP 2935 bool 2936 depends on STA2X11 2937 2938config HAVE_GENERIC_GUP 2939 def_bool y 2940 2941source "drivers/firmware/Kconfig" 2942 2943source "arch/x86/kvm/Kconfig" 2944