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_32BIT_OFF_T if X86_32 51 select ARCH_CLOCKSOURCE_DATA 52 select ARCH_CLOCKSOURCE_INIT 53 select ARCH_DISCARD_MEMBLOCK 54 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 55 select ARCH_HAS_DEBUG_VIRTUAL 56 select ARCH_HAS_DEVMEM_IS_ALLOWED 57 select ARCH_HAS_ELF_RANDOMIZE 58 select ARCH_HAS_FAST_MULTIPLIER 59 select ARCH_HAS_FILTER_PGPROT 60 select ARCH_HAS_FORTIFY_SOURCE 61 select ARCH_HAS_GCOV_PROFILE_ALL 62 select ARCH_HAS_KCOV if X86_64 63 select ARCH_HAS_MEMBARRIER_SYNC_CORE 64 select ARCH_HAS_PMEM_API if X86_64 65 select ARCH_HAS_PTE_SPECIAL 66 select ARCH_HAS_REFCOUNT 67 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 68 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 69 select ARCH_HAS_SET_MEMORY 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 EDAC_ATOMIC_SCRUB 94 select EDAC_SUPPORT 95 select GENERIC_CLOCKEVENTS 96 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 97 select GENERIC_CLOCKEVENTS_MIN_ADJUST 98 select GENERIC_CMOS_UPDATE 99 select GENERIC_CPU_AUTOPROBE 100 select GENERIC_CPU_VULNERABILITIES 101 select GENERIC_EARLY_IOREMAP 102 select GENERIC_FIND_FIRST_BIT 103 select GENERIC_IOMAP 104 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 105 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 106 select GENERIC_IRQ_MIGRATION if SMP 107 select GENERIC_IRQ_PROBE 108 select GENERIC_IRQ_RESERVATION_MODE 109 select GENERIC_IRQ_SHOW 110 select GENERIC_PENDING_IRQ if SMP 111 select GENERIC_SMP_IDLE_THREAD 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select GENERIC_TIME_VSYSCALL 115 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 116 select HAVE_ACPI_APEI if ACPI 117 select HAVE_ACPI_APEI_NMI if ACPI 118 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 119 select HAVE_ARCH_AUDITSYSCALL 120 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 121 select HAVE_ARCH_JUMP_LABEL 122 select HAVE_ARCH_JUMP_LABEL_RELATIVE 123 select HAVE_ARCH_KASAN if X86_64 124 select HAVE_ARCH_KGDB 125 select HAVE_ARCH_MMAP_RND_BITS if MMU 126 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 127 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 128 select HAVE_ARCH_PREL32_RELOCATIONS 129 select HAVE_ARCH_SECCOMP_FILTER 130 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 131 select HAVE_ARCH_STACKLEAK 132 select HAVE_ARCH_TRACEHOOK 133 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 134 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 135 select HAVE_ARCH_VMAP_STACK if X86_64 136 select HAVE_ARCH_WITHIN_STACK_FRAMES 137 select HAVE_CMPXCHG_DOUBLE 138 select HAVE_CMPXCHG_LOCAL 139 select HAVE_CONTEXT_TRACKING if X86_64 140 select HAVE_COPY_THREAD_TLS 141 select HAVE_C_RECORDMCOUNT 142 select HAVE_DEBUG_KMEMLEAK 143 select HAVE_DEBUG_STACKOVERFLOW 144 select HAVE_DMA_CONTIGUOUS 145 select HAVE_DYNAMIC_FTRACE 146 select HAVE_DYNAMIC_FTRACE_WITH_REGS 147 select HAVE_EBPF_JIT 148 select HAVE_EFFICIENT_UNALIGNED_ACCESS 149 select HAVE_EISA 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_MOVE_PMD 177 select HAVE_NMI 178 select HAVE_OPROFILE 179 select HAVE_OPTPROBES 180 select HAVE_PCSPKR_PLATFORM 181 select HAVE_PERF_EVENTS 182 select HAVE_PERF_EVENTS_NMI 183 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 184 select HAVE_PCI 185 select HAVE_PERF_REGS 186 select HAVE_PERF_USER_STACK_DUMP 187 select HAVE_RCU_TABLE_FREE if PARAVIRT 188 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 189 select HAVE_REGS_AND_STACK_ACCESS_API 190 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 191 select HAVE_FUNCTION_ARG_ACCESS_API 192 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 193 select HAVE_STACK_VALIDATION if X86_64 194 select HAVE_RSEQ 195 select HAVE_SYSCALL_TRACEPOINTS 196 select HAVE_UNSTABLE_SCHED_CLOCK 197 select HAVE_USER_RETURN_NOTIFIER 198 select HOTPLUG_SMT if SMP 199 select IRQ_FORCED_THREADING 200 select NEED_SG_DMA_LENGTH 201 select PCI_DOMAINS if PCI 202 select PCI_LOCKLESS_CONFIG 203 select PERF_EVENTS 204 select RTC_LIB 205 select RTC_MC146818_LIB 206 select SPARSE_IRQ 207 select SRCU 208 select SYSCTL_EXCEPTION_TRACE 209 select THREAD_INFO_IN_TASK 210 select USER_STACKTRACE_SUPPORT 211 select VIRT_TO_BUS 212 select X86_FEATURE_NAMES if PROC_FS 213 214config INSTRUCTION_DECODER 215 def_bool y 216 depends on KPROBES || PERF_EVENTS || UPROBES 217 218config OUTPUT_FORMAT 219 string 220 default "elf32-i386" if X86_32 221 default "elf64-x86-64" if X86_64 222 223config ARCH_DEFCONFIG 224 string 225 default "arch/x86/configs/i386_defconfig" if X86_32 226 default "arch/x86/configs/x86_64_defconfig" if X86_64 227 228config LOCKDEP_SUPPORT 229 def_bool y 230 231config STACKTRACE_SUPPORT 232 def_bool y 233 234config MMU 235 def_bool y 236 237config ARCH_MMAP_RND_BITS_MIN 238 default 28 if 64BIT 239 default 8 240 241config ARCH_MMAP_RND_BITS_MAX 242 default 32 if 64BIT 243 default 16 244 245config ARCH_MMAP_RND_COMPAT_BITS_MIN 246 default 8 247 248config ARCH_MMAP_RND_COMPAT_BITS_MAX 249 default 16 250 251config SBUS 252 bool 253 254config GENERIC_ISA_DMA 255 def_bool y 256 depends on ISA_DMA_API 257 258config GENERIC_BUG 259 def_bool y 260 depends on BUG 261 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 262 263config GENERIC_BUG_RELATIVE_POINTERS 264 bool 265 266config GENERIC_HWEIGHT 267 def_bool y 268 269config ARCH_MAY_HAVE_PC_FDC 270 def_bool y 271 depends on ISA_DMA_API 272 273config RWSEM_XCHGADD_ALGORITHM 274 def_bool y 275 276config GENERIC_CALIBRATE_DELAY 277 def_bool y 278 279config ARCH_HAS_CPU_RELAX 280 def_bool y 281 282config ARCH_HAS_CACHE_LINE_SIZE 283 def_bool y 284 285config ARCH_HAS_FILTER_PGPROT 286 def_bool y 287 288config HAVE_SETUP_PER_CPU_AREA 289 def_bool y 290 291config NEED_PER_CPU_EMBED_FIRST_CHUNK 292 def_bool y 293 294config NEED_PER_CPU_PAGE_FIRST_CHUNK 295 def_bool y 296 297config ARCH_HIBERNATION_POSSIBLE 298 def_bool y 299 300config ARCH_SUSPEND_POSSIBLE 301 def_bool y 302 303config ARCH_WANT_HUGE_PMD_SHARE 304 def_bool y 305 306config ARCH_WANT_GENERAL_HUGETLB 307 def_bool y 308 309config ZONE_DMA32 310 def_bool y if X86_64 311 312config AUDIT_ARCH 313 def_bool y if X86_64 314 315config ARCH_SUPPORTS_OPTIMIZED_INLINING 316 def_bool y 317 318config ARCH_SUPPORTS_DEBUG_PAGEALLOC 319 def_bool y 320 321config KASAN_SHADOW_OFFSET 322 hex 323 depends on KASAN 324 default 0xdffffc0000000000 325 326config HAVE_INTEL_TXT 327 def_bool y 328 depends on INTEL_IOMMU && ACPI 329 330config X86_32_SMP 331 def_bool y 332 depends on X86_32 && SMP 333 334config X86_64_SMP 335 def_bool y 336 depends on X86_64 && SMP 337 338config X86_32_LAZY_GS 339 def_bool y 340 depends on X86_32 && !STACKPROTECTOR 341 342config ARCH_SUPPORTS_UPROBES 343 def_bool y 344 345config FIX_EARLYCON_MEM 346 def_bool y 347 348config DYNAMIC_PHYSICAL_MASK 349 bool 350 351config PGTABLE_LEVELS 352 int 353 default 5 if X86_5LEVEL 354 default 4 if X86_64 355 default 3 if X86_PAE 356 default 2 357 358config CC_HAS_SANE_STACKPROTECTOR 359 bool 360 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 361 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 362 help 363 We have to make sure stack protector is unconditionally disabled if 364 the compiler produces broken code. 365 366menu "Processor type and features" 367 368config ZONE_DMA 369 bool "DMA memory allocation support" if EXPERT 370 default y 371 help 372 DMA memory allocation support allows devices with less than 32-bit 373 addressing to allocate within the first 16MB of address space. 374 Disable if no such devices will be used. 375 376 If unsure, say Y. 377 378config SMP 379 bool "Symmetric multi-processing support" 380 ---help--- 381 This enables support for systems with more than one CPU. If you have 382 a system with only one CPU, say N. If you have a system with more 383 than one CPU, say Y. 384 385 If you say N here, the kernel will run on uni- and multiprocessor 386 machines, but will use only one CPU of a multiprocessor machine. If 387 you say Y here, the kernel will run on many, but not all, 388 uniprocessor machines. On a uniprocessor machine, the kernel 389 will run faster if you say N here. 390 391 Note that if you say Y here and choose architecture "586" or 392 "Pentium" under "Processor family", the kernel will not work on 486 393 architectures. Similarly, multiprocessor kernels for the "PPro" 394 architecture may not work on all Pentium based boards. 395 396 People using multiprocessor machines who say Y here should also say 397 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 398 Management" code will be disabled if you say Y here. 399 400 See also <file:Documentation/x86/i386/IO-APIC.txt>, 401 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 402 <http://www.tldp.org/docs.html#howto>. 403 404 If you don't know what to do here, say N. 405 406config X86_FEATURE_NAMES 407 bool "Processor feature human-readable names" if EMBEDDED 408 default y 409 ---help--- 410 This option compiles in a table of x86 feature bits and corresponding 411 names. This is required to support /proc/cpuinfo and a few kernel 412 messages. You can disable this to save space, at the expense of 413 making those few kernel messages show numeric feature bits instead. 414 415 If in doubt, say Y. 416 417config X86_X2APIC 418 bool "Support x2apic" 419 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 420 ---help--- 421 This enables x2apic support on CPUs that have this feature. 422 423 This allows 32-bit apic IDs (so it can support very large systems), 424 and accesses the local apic via MSRs not via mmio. 425 426 If you don't know what to do here, say N. 427 428config X86_MPPARSE 429 bool "Enable MPS table" if ACPI || SFI 430 default y 431 depends on X86_LOCAL_APIC 432 ---help--- 433 For old smp systems that do not have proper acpi support. Newer systems 434 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 435 436config GOLDFISH 437 def_bool y 438 depends on X86_GOLDFISH 439 440config RETPOLINE 441 bool "Avoid speculative indirect branches in kernel" 442 default y 443 select STACK_VALIDATION if HAVE_STACK_VALIDATION 444 help 445 Compile kernel with the retpoline compiler options to guard against 446 kernel-to-user data leaks by avoiding speculative indirect 447 branches. Requires a compiler with -mindirect-branch=thunk-extern 448 support for full protection. The kernel may run slower. 449 450config X86_RESCTRL 451 bool "Resource Control support" 452 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 453 select KERNFS 454 help 455 Enable Resource Control support. 456 457 Provide support for the allocation and monitoring of system resources 458 usage by the CPU. 459 460 Intel calls this Intel Resource Director Technology 461 (Intel(R) RDT). More information about RDT can be found in the 462 Intel x86 Architecture Software Developer Manual. 463 464 AMD calls this AMD Platform Quality of Service (AMD QoS). 465 More information about AMD QoS can be found in the AMD64 Technology 466 Platform Quality of Service Extensions manual. 467 468 Say N if unsure. 469 470if X86_32 471config X86_BIGSMP 472 bool "Support for big SMP systems with more than 8 CPUs" 473 depends on SMP 474 ---help--- 475 This option is needed for the systems that have more than 8 CPUs 476 477config X86_EXTENDED_PLATFORM 478 bool "Support for extended (non-PC) x86 platforms" 479 default y 480 ---help--- 481 If you disable this option then the kernel will only support 482 standard PC platforms. (which covers the vast majority of 483 systems out there.) 484 485 If you enable this option then you'll be able to select support 486 for the following (non-PC) 32 bit x86 platforms: 487 Goldfish (Android emulator) 488 AMD Elan 489 RDC R-321x SoC 490 SGI 320/540 (Visual Workstation) 491 STA2X11-based (e.g. Northville) 492 Moorestown MID devices 493 494 If you have one of these systems, or if you want to build a 495 generic distribution kernel, say Y here - otherwise say N. 496endif 497 498if X86_64 499config X86_EXTENDED_PLATFORM 500 bool "Support for extended (non-PC) x86 platforms" 501 default y 502 ---help--- 503 If you disable this option then the kernel will only support 504 standard PC platforms. (which covers the vast majority of 505 systems out there.) 506 507 If you enable this option then you'll be able to select support 508 for the following (non-PC) 64 bit x86 platforms: 509 Numascale NumaChip 510 ScaleMP vSMP 511 SGI Ultraviolet 512 513 If you have one of these systems, or if you want to build a 514 generic distribution kernel, say Y here - otherwise say N. 515endif 516# This is an alphabetically sorted list of 64 bit extended platforms 517# Please maintain the alphabetic order if and when there are additions 518config X86_NUMACHIP 519 bool "Numascale NumaChip" 520 depends on X86_64 521 depends on X86_EXTENDED_PLATFORM 522 depends on NUMA 523 depends on SMP 524 depends on X86_X2APIC 525 depends on PCI_MMCONFIG 526 ---help--- 527 Adds support for Numascale NumaChip large-SMP systems. Needed to 528 enable more than ~168 cores. 529 If you don't have one of these, you should say N here. 530 531config X86_VSMP 532 bool "ScaleMP vSMP" 533 select HYPERVISOR_GUEST 534 select PARAVIRT 535 depends on X86_64 && PCI 536 depends on X86_EXTENDED_PLATFORM 537 depends on SMP 538 ---help--- 539 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 540 supposed to run on these EM64T-based machines. Only choose this option 541 if you have one of these machines. 542 543config X86_UV 544 bool "SGI Ultraviolet" 545 depends on X86_64 546 depends on X86_EXTENDED_PLATFORM 547 depends on NUMA 548 depends on EFI 549 depends on X86_X2APIC 550 depends on PCI 551 ---help--- 552 This option is needed in order to support SGI Ultraviolet systems. 553 If you don't have one of these, you should say N here. 554 555# Following is an alphabetically sorted list of 32 bit extended platforms 556# Please maintain the alphabetic order if and when there are additions 557 558config X86_GOLDFISH 559 bool "Goldfish (Virtual Platform)" 560 depends on X86_EXTENDED_PLATFORM 561 ---help--- 562 Enable support for the Goldfish virtual platform used primarily 563 for Android development. Unless you are building for the Android 564 Goldfish emulator say N here. 565 566config X86_INTEL_CE 567 bool "CE4100 TV platform" 568 depends on PCI 569 depends on PCI_GODIRECT 570 depends on X86_IO_APIC 571 depends on X86_32 572 depends on X86_EXTENDED_PLATFORM 573 select X86_REBOOTFIXUPS 574 select OF 575 select OF_EARLY_FLATTREE 576 ---help--- 577 Select for the Intel CE media processor (CE4100) SOC. 578 This option compiles in support for the CE4100 SOC for settop 579 boxes and media devices. 580 581config X86_INTEL_MID 582 bool "Intel MID platform support" 583 depends on X86_EXTENDED_PLATFORM 584 depends on X86_PLATFORM_DEVICES 585 depends on PCI 586 depends on X86_64 || (PCI_GOANY && X86_32) 587 depends on X86_IO_APIC 588 select SFI 589 select I2C 590 select DW_APB_TIMER 591 select APB_TIMER 592 select INTEL_SCU_IPC 593 select MFD_INTEL_MSIC 594 ---help--- 595 Select to build a kernel capable of supporting Intel MID (Mobile 596 Internet Device) platform systems which do not have the PCI legacy 597 interfaces. If you are building for a PC class system say N here. 598 599 Intel MID platforms are based on an Intel processor and chipset which 600 consume less power than most of the x86 derivatives. 601 602config X86_INTEL_QUARK 603 bool "Intel Quark platform support" 604 depends on X86_32 605 depends on X86_EXTENDED_PLATFORM 606 depends on X86_PLATFORM_DEVICES 607 depends on X86_TSC 608 depends on PCI 609 depends on PCI_GOANY 610 depends on X86_IO_APIC 611 select IOSF_MBI 612 select INTEL_IMR 613 select COMMON_CLK 614 ---help--- 615 Select to include support for Quark X1000 SoC. 616 Say Y here if you have a Quark based system such as the Arduino 617 compatible Intel Galileo. 618 619config X86_INTEL_LPSS 620 bool "Intel Low Power Subsystem Support" 621 depends on X86 && ACPI 622 select COMMON_CLK 623 select PINCTRL 624 select IOSF_MBI 625 ---help--- 626 Select to build support for Intel Low Power Subsystem such as 627 found on Intel Lynxpoint PCH. Selecting this option enables 628 things like clock tree (common clock framework) and pincontrol 629 which are needed by the LPSS peripheral drivers. 630 631config X86_AMD_PLATFORM_DEVICE 632 bool "AMD ACPI2Platform devices support" 633 depends on ACPI 634 select COMMON_CLK 635 select PINCTRL 636 ---help--- 637 Select to interpret AMD specific ACPI device to platform device 638 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 639 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 640 implemented under PINCTRL subsystem. 641 642config IOSF_MBI 643 tristate "Intel SoC IOSF Sideband support for SoC platforms" 644 depends on PCI 645 ---help--- 646 This option enables sideband register access support for Intel SoC 647 platforms. On these platforms the IOSF sideband is used in lieu of 648 MSR's for some register accesses, mostly but not limited to thermal 649 and power. Drivers may query the availability of this device to 650 determine if they need the sideband in order to work on these 651 platforms. The sideband is available on the following SoC products. 652 This list is not meant to be exclusive. 653 - BayTrail 654 - Braswell 655 - Quark 656 657 You should say Y if you are running a kernel on one of these SoC's. 658 659config IOSF_MBI_DEBUG 660 bool "Enable IOSF sideband access through debugfs" 661 depends on IOSF_MBI && DEBUG_FS 662 ---help--- 663 Select this option to expose the IOSF sideband access registers (MCR, 664 MDR, MCRX) through debugfs to write and read register information from 665 different units on the SoC. This is most useful for obtaining device 666 state information for debug and analysis. As this is a general access 667 mechanism, users of this option would have specific knowledge of the 668 device they want to access. 669 670 If you don't require the option or are in doubt, say N. 671 672config X86_RDC321X 673 bool "RDC R-321x SoC" 674 depends on X86_32 675 depends on X86_EXTENDED_PLATFORM 676 select M486 677 select X86_REBOOTFIXUPS 678 ---help--- 679 This option is needed for RDC R-321x system-on-chip, also known 680 as R-8610-(G). 681 If you don't have one of these chips, you should say N here. 682 683config X86_32_NON_STANDARD 684 bool "Support non-standard 32-bit SMP architectures" 685 depends on X86_32 && SMP 686 depends on X86_EXTENDED_PLATFORM 687 ---help--- 688 This option compiles in the bigsmp and STA2X11 default 689 subarchitectures. It is intended for a generic binary 690 kernel. If you select them all, kernel will probe it one by 691 one and will fallback to default. 692 693# Alphabetically sorted list of Non standard 32 bit platforms 694 695config X86_SUPPORTS_MEMORY_FAILURE 696 def_bool y 697 # MCE code calls memory_failure(): 698 depends on X86_MCE 699 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 700 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 701 depends on X86_64 || !SPARSEMEM 702 select ARCH_SUPPORTS_MEMORY_FAILURE 703 704config STA2X11 705 bool "STA2X11 Companion Chip Support" 706 depends on X86_32_NON_STANDARD && PCI 707 select ARCH_HAS_PHYS_TO_DMA 708 select X86_DEV_DMA_OPS 709 select X86_DMA_REMAP 710 select SWIOTLB 711 select MFD_STA2X11 712 select GPIOLIB 713 ---help--- 714 This adds support for boards based on the STA2X11 IO-Hub, 715 a.k.a. "ConneXt". The chip is used in place of the standard 716 PC chipset, so all "standard" peripherals are missing. If this 717 option is selected the kernel will still be able to boot on 718 standard PC machines. 719 720config X86_32_IRIS 721 tristate "Eurobraille/Iris poweroff module" 722 depends on X86_32 723 ---help--- 724 The Iris machines from EuroBraille do not have APM or ACPI support 725 to shut themselves down properly. A special I/O sequence is 726 needed to do so, which is what this module does at 727 kernel shutdown. 728 729 This is only for Iris machines from EuroBraille. 730 731 If unused, say N. 732 733config SCHED_OMIT_FRAME_POINTER 734 def_bool y 735 prompt "Single-depth WCHAN output" 736 depends on X86 737 ---help--- 738 Calculate simpler /proc/<PID>/wchan values. If this option 739 is disabled then wchan values will recurse back to the 740 caller function. This provides more accurate wchan values, 741 at the expense of slightly more scheduling overhead. 742 743 If in doubt, say "Y". 744 745menuconfig HYPERVISOR_GUEST 746 bool "Linux guest support" 747 ---help--- 748 Say Y here to enable options for running Linux under various hyper- 749 visors. This option enables basic hypervisor detection and platform 750 setup. 751 752 If you say N, all options in this submenu will be skipped and 753 disabled, and Linux guest support won't be built in. 754 755if HYPERVISOR_GUEST 756 757config PARAVIRT 758 bool "Enable paravirtualization code" 759 ---help--- 760 This changes the kernel so it can modify itself when it is run 761 under a hypervisor, potentially improving performance significantly 762 over full virtualization. However, when run without a hypervisor 763 the kernel is theoretically slower and slightly larger. 764 765config PARAVIRT_XXL 766 bool 767 768config PARAVIRT_DEBUG 769 bool "paravirt-ops debugging" 770 depends on PARAVIRT && DEBUG_KERNEL 771 ---help--- 772 Enable to debug paravirt_ops internals. Specifically, BUG if 773 a paravirt_op is missing when it is called. 774 775config PARAVIRT_SPINLOCKS 776 bool "Paravirtualization layer for spinlocks" 777 depends on PARAVIRT && SMP 778 ---help--- 779 Paravirtualized spinlocks allow a pvops backend to replace the 780 spinlock implementation with something virtualization-friendly 781 (for example, block the virtual CPU rather than spinning). 782 783 It has a minimal impact on native kernels and gives a nice performance 784 benefit on paravirtualized KVM / Xen kernels. 785 786 If you are unsure how to answer this question, answer Y. 787 788config QUEUED_LOCK_STAT 789 bool "Paravirt queued spinlock statistics" 790 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 791 ---help--- 792 Enable the collection of statistical data on the slowpath 793 behavior of paravirtualized queued spinlocks and report 794 them on debugfs. 795 796source "arch/x86/xen/Kconfig" 797 798config KVM_GUEST 799 bool "KVM Guest support (including kvmclock)" 800 depends on PARAVIRT 801 select PARAVIRT_CLOCK 802 default y 803 ---help--- 804 This option enables various optimizations for running under the KVM 805 hypervisor. It includes a paravirtualized clock, so that instead 806 of relying on a PIT (or probably other) emulation by the 807 underlying device model, the host provides the guest with 808 timing infrastructure such as time of day, and system time 809 810config PVH 811 bool "Support for running PVH guests" 812 ---help--- 813 This option enables the PVH entry point for guest virtual machines 814 as specified in the x86/HVM direct boot ABI. 815 816config KVM_DEBUG_FS 817 bool "Enable debug information for KVM Guests in debugfs" 818 depends on KVM_GUEST && DEBUG_FS 819 ---help--- 820 This option enables collection of various statistics for KVM guest. 821 Statistics are displayed in debugfs filesystem. Enabling this option 822 may incur significant overhead. 823 824config PARAVIRT_TIME_ACCOUNTING 825 bool "Paravirtual steal time accounting" 826 depends on PARAVIRT 827 ---help--- 828 Select this option to enable fine granularity task steal time 829 accounting. Time spent executing other tasks in parallel with 830 the current vCPU is discounted from the vCPU power. To account for 831 that, there can be a small performance impact. 832 833 If in doubt, say N here. 834 835config PARAVIRT_CLOCK 836 bool 837 838config JAILHOUSE_GUEST 839 bool "Jailhouse non-root cell support" 840 depends on X86_64 && PCI 841 select X86_PM_TIMER 842 ---help--- 843 This option allows to run Linux as guest in a Jailhouse non-root 844 cell. You can leave this option disabled if you only want to start 845 Jailhouse and run Linux afterwards in the root cell. 846 847endif #HYPERVISOR_GUEST 848 849source "arch/x86/Kconfig.cpu" 850 851config HPET_TIMER 852 def_bool X86_64 853 prompt "HPET Timer Support" if X86_32 854 ---help--- 855 Use the IA-PC HPET (High Precision Event Timer) to manage 856 time in preference to the PIT and RTC, if a HPET is 857 present. 858 HPET is the next generation timer replacing legacy 8254s. 859 The HPET provides a stable time base on SMP 860 systems, unlike the TSC, but it is more expensive to access, 861 as it is off-chip. The interface used is documented 862 in the HPET spec, revision 1. 863 864 You can safely choose Y here. However, HPET will only be 865 activated if the platform and the BIOS support this feature. 866 Otherwise the 8254 will be used for timing services. 867 868 Choose N to continue using the legacy 8254 timer. 869 870config HPET_EMULATE_RTC 871 def_bool y 872 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 873 874config APB_TIMER 875 def_bool y if X86_INTEL_MID 876 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 877 select DW_APB_TIMER 878 depends on X86_INTEL_MID && SFI 879 help 880 APB timer is the replacement for 8254, HPET on X86 MID platforms. 881 The APBT provides a stable time base on SMP 882 systems, unlike the TSC, but it is more expensive to access, 883 as it is off-chip. APB timers are always running regardless of CPU 884 C states, they are used as per CPU clockevent device when possible. 885 886# Mark as expert because too many people got it wrong. 887# The code disables itself when not needed. 888config DMI 889 default y 890 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 891 bool "Enable DMI scanning" if EXPERT 892 ---help--- 893 Enabled scanning of DMI to identify machine quirks. Say Y 894 here unless you have verified that your setup is not 895 affected by entries in the DMI blacklist. Required by PNP 896 BIOS code. 897 898config GART_IOMMU 899 bool "Old AMD GART IOMMU support" 900 select IOMMU_HELPER 901 select SWIOTLB 902 depends on X86_64 && PCI && AMD_NB 903 ---help--- 904 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 905 GART based hardware IOMMUs. 906 907 The GART supports full DMA access for devices with 32-bit access 908 limitations, on systems with more than 3 GB. This is usually needed 909 for USB, sound, many IDE/SATA chipsets and some other devices. 910 911 Newer systems typically have a modern AMD IOMMU, supported via 912 the CONFIG_AMD_IOMMU=y config option. 913 914 In normal configurations this driver is only active when needed: 915 there's more than 3 GB of memory and the system contains a 916 32-bit limited device. 917 918 If unsure, say Y. 919 920config CALGARY_IOMMU 921 bool "IBM Calgary IOMMU support" 922 select IOMMU_HELPER 923 select SWIOTLB 924 depends on X86_64 && PCI 925 ---help--- 926 Support for hardware IOMMUs in IBM's xSeries x366 and x460 927 systems. Needed to run systems with more than 3GB of memory 928 properly with 32-bit PCI devices that do not support DAC 929 (Double Address Cycle). Calgary also supports bus level 930 isolation, where all DMAs pass through the IOMMU. This 931 prevents them from going anywhere except their intended 932 destination. This catches hard-to-find kernel bugs and 933 mis-behaving drivers and devices that do not use the DMA-API 934 properly to set up their DMA buffers. The IOMMU can be 935 turned off at boot time with the iommu=off parameter. 936 Normally the kernel will make the right choice by itself. 937 If unsure, say Y. 938 939config CALGARY_IOMMU_ENABLED_BY_DEFAULT 940 def_bool y 941 prompt "Should Calgary be enabled by default?" 942 depends on CALGARY_IOMMU 943 ---help--- 944 Should Calgary be enabled by default? if you choose 'y', Calgary 945 will be used (if it exists). If you choose 'n', Calgary will not be 946 used even if it exists. If you choose 'n' and would like to use 947 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 948 If unsure, say Y. 949 950config MAXSMP 951 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 952 depends on X86_64 && SMP && DEBUG_KERNEL 953 select CPUMASK_OFFSTACK 954 ---help--- 955 Enable maximum number of CPUS and NUMA Nodes for this architecture. 956 If unsure, say N. 957 958# 959# The maximum number of CPUs supported: 960# 961# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 962# and which can be configured interactively in the 963# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 964# 965# The ranges are different on 32-bit and 64-bit kernels, depending on 966# hardware capabilities and scalability features of the kernel. 967# 968# ( If MAXSMP is enabled we just use the highest possible value and disable 969# interactive configuration. ) 970# 971 972config NR_CPUS_RANGE_BEGIN 973 int 974 default NR_CPUS_RANGE_END if MAXSMP 975 default 1 if !SMP 976 default 2 977 978config NR_CPUS_RANGE_END 979 int 980 depends on X86_32 981 default 64 if SMP && X86_BIGSMP 982 default 8 if SMP && !X86_BIGSMP 983 default 1 if !SMP 984 985config NR_CPUS_RANGE_END 986 int 987 depends on X86_64 988 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 989 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 990 default 1 if !SMP 991 992config NR_CPUS_DEFAULT 993 int 994 depends on X86_32 995 default 32 if X86_BIGSMP 996 default 8 if SMP 997 default 1 if !SMP 998 999config NR_CPUS_DEFAULT 1000 int 1001 depends on X86_64 1002 default 8192 if MAXSMP 1003 default 64 if SMP 1004 default 1 if !SMP 1005 1006config NR_CPUS 1007 int "Maximum number of CPUs" if SMP && !MAXSMP 1008 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1009 default NR_CPUS_DEFAULT 1010 ---help--- 1011 This allows you to specify the maximum number of CPUs which this 1012 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1013 supported value is 8192, otherwise the maximum value is 512. The 1014 minimum value which makes sense is 2. 1015 1016 This is purely to save memory: each supported CPU adds about 8KB 1017 to the kernel image. 1018 1019config SCHED_SMT 1020 def_bool y if SMP 1021 1022config SCHED_MC 1023 def_bool y 1024 prompt "Multi-core scheduler support" 1025 depends on SMP 1026 ---help--- 1027 Multi-core scheduler support improves the CPU scheduler's decision 1028 making when dealing with multi-core CPU chips at a cost of slightly 1029 increased overhead in some places. If unsure say N here. 1030 1031config SCHED_MC_PRIO 1032 bool "CPU core priorities scheduler support" 1033 depends on SCHED_MC && CPU_SUP_INTEL 1034 select X86_INTEL_PSTATE 1035 select CPU_FREQ 1036 default y 1037 ---help--- 1038 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1039 core ordering determined at manufacturing time, which allows 1040 certain cores to reach higher turbo frequencies (when running 1041 single threaded workloads) than others. 1042 1043 Enabling this kernel feature teaches the scheduler about 1044 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1045 scheduler's CPU selection logic accordingly, so that higher 1046 overall system performance can be achieved. 1047 1048 This feature will have no effect on CPUs without this feature. 1049 1050 If unsure say Y here. 1051 1052config UP_LATE_INIT 1053 def_bool y 1054 depends on !SMP && X86_LOCAL_APIC 1055 1056config X86_UP_APIC 1057 bool "Local APIC support on uniprocessors" if !PCI_MSI 1058 default PCI_MSI 1059 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1060 ---help--- 1061 A local APIC (Advanced Programmable Interrupt Controller) is an 1062 integrated interrupt controller in the CPU. If you have a single-CPU 1063 system which has a processor with a local APIC, you can say Y here to 1064 enable and use it. If you say Y here even though your machine doesn't 1065 have a local APIC, then the kernel will still run with no slowdown at 1066 all. The local APIC supports CPU-generated self-interrupts (timer, 1067 performance counters), and the NMI watchdog which detects hard 1068 lockups. 1069 1070config X86_UP_IOAPIC 1071 bool "IO-APIC support on uniprocessors" 1072 depends on X86_UP_APIC 1073 ---help--- 1074 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1075 SMP-capable replacement for PC-style interrupt controllers. Most 1076 SMP systems and many recent uniprocessor systems have one. 1077 1078 If you have a single-CPU system with an IO-APIC, you can say Y here 1079 to use it. If you say Y here even though your machine doesn't have 1080 an IO-APIC, then the kernel will still run with no slowdown at all. 1081 1082config X86_LOCAL_APIC 1083 def_bool y 1084 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1085 select IRQ_DOMAIN_HIERARCHY 1086 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1087 1088config X86_IO_APIC 1089 def_bool y 1090 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1091 1092config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1093 bool "Reroute for broken boot IRQs" 1094 depends on X86_IO_APIC 1095 ---help--- 1096 This option enables a workaround that fixes a source of 1097 spurious interrupts. This is recommended when threaded 1098 interrupt handling is used on systems where the generation of 1099 superfluous "boot interrupts" cannot be disabled. 1100 1101 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1102 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1103 kernel does during interrupt handling). On chipsets where this 1104 boot IRQ generation cannot be disabled, this workaround keeps 1105 the original IRQ line masked so that only the equivalent "boot 1106 IRQ" is delivered to the CPUs. The workaround also tells the 1107 kernel to set up the IRQ handler on the boot IRQ line. In this 1108 way only one interrupt is delivered to the kernel. Otherwise 1109 the spurious second interrupt may cause the kernel to bring 1110 down (vital) interrupt lines. 1111 1112 Only affects "broken" chipsets. Interrupt sharing may be 1113 increased on these systems. 1114 1115config X86_MCE 1116 bool "Machine Check / overheating reporting" 1117 select GENERIC_ALLOCATOR 1118 default y 1119 ---help--- 1120 Machine Check support allows the processor to notify the 1121 kernel if it detects a problem (e.g. overheating, data corruption). 1122 The action the kernel takes depends on the severity of the problem, 1123 ranging from warning messages to halting the machine. 1124 1125config X86_MCELOG_LEGACY 1126 bool "Support for deprecated /dev/mcelog character device" 1127 depends on X86_MCE 1128 ---help--- 1129 Enable support for /dev/mcelog which is needed by the old mcelog 1130 userspace logging daemon. Consider switching to the new generation 1131 rasdaemon solution. 1132 1133config X86_MCE_INTEL 1134 def_bool y 1135 prompt "Intel MCE features" 1136 depends on X86_MCE && X86_LOCAL_APIC 1137 ---help--- 1138 Additional support for intel specific MCE features such as 1139 the thermal monitor. 1140 1141config X86_MCE_AMD 1142 def_bool y 1143 prompt "AMD MCE features" 1144 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1145 ---help--- 1146 Additional support for AMD specific MCE features such as 1147 the DRAM Error Threshold. 1148 1149config X86_ANCIENT_MCE 1150 bool "Support for old Pentium 5 / WinChip machine checks" 1151 depends on X86_32 && X86_MCE 1152 ---help--- 1153 Include support for machine check handling on old Pentium 5 or WinChip 1154 systems. These typically need to be enabled explicitly on the command 1155 line. 1156 1157config X86_MCE_THRESHOLD 1158 depends on X86_MCE_AMD || X86_MCE_INTEL 1159 def_bool y 1160 1161config X86_MCE_INJECT 1162 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1163 tristate "Machine check injector support" 1164 ---help--- 1165 Provide support for injecting machine checks for testing purposes. 1166 If you don't know what a machine check is and you don't do kernel 1167 QA it is safe to say n. 1168 1169config X86_THERMAL_VECTOR 1170 def_bool y 1171 depends on X86_MCE_INTEL 1172 1173source "arch/x86/events/Kconfig" 1174 1175config X86_LEGACY_VM86 1176 bool "Legacy VM86 support" 1177 depends on X86_32 1178 ---help--- 1179 This option allows user programs to put the CPU into V8086 1180 mode, which is an 80286-era approximation of 16-bit real mode. 1181 1182 Some very old versions of X and/or vbetool require this option 1183 for user mode setting. Similarly, DOSEMU will use it if 1184 available to accelerate real mode DOS programs. However, any 1185 recent version of DOSEMU, X, or vbetool should be fully 1186 functional even without kernel VM86 support, as they will all 1187 fall back to software emulation. Nevertheless, if you are using 1188 a 16-bit DOS program where 16-bit performance matters, vm86 1189 mode might be faster than emulation and you might want to 1190 enable this option. 1191 1192 Note that any app that works on a 64-bit kernel is unlikely to 1193 need this option, as 64-bit kernels don't, and can't, support 1194 V8086 mode. This option is also unrelated to 16-bit protected 1195 mode and is not needed to run most 16-bit programs under Wine. 1196 1197 Enabling this option increases the complexity of the kernel 1198 and slows down exception handling a tiny bit. 1199 1200 If unsure, say N here. 1201 1202config VM86 1203 bool 1204 default X86_LEGACY_VM86 1205 1206config X86_16BIT 1207 bool "Enable support for 16-bit segments" if EXPERT 1208 default y 1209 depends on MODIFY_LDT_SYSCALL 1210 ---help--- 1211 This option is required by programs like Wine to run 16-bit 1212 protected mode legacy code on x86 processors. Disabling 1213 this option saves about 300 bytes on i386, or around 6K text 1214 plus 16K runtime memory on x86-64, 1215 1216config X86_ESPFIX32 1217 def_bool y 1218 depends on X86_16BIT && X86_32 1219 1220config X86_ESPFIX64 1221 def_bool y 1222 depends on X86_16BIT && X86_64 1223 1224config X86_VSYSCALL_EMULATION 1225 bool "Enable vsyscall emulation" if EXPERT 1226 default y 1227 depends on X86_64 1228 ---help--- 1229 This enables emulation of the legacy vsyscall page. Disabling 1230 it is roughly equivalent to booting with vsyscall=none, except 1231 that it will also disable the helpful warning if a program 1232 tries to use a vsyscall. With this option set to N, offending 1233 programs will just segfault, citing addresses of the form 1234 0xffffffffff600?00. 1235 1236 This option is required by many programs built before 2013, and 1237 care should be used even with newer programs if set to N. 1238 1239 Disabling this option saves about 7K of kernel size and 1240 possibly 4K of additional runtime pagetable memory. 1241 1242config TOSHIBA 1243 tristate "Toshiba Laptop support" 1244 depends on X86_32 1245 ---help--- 1246 This adds a driver to safely access the System Management Mode of 1247 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1248 not work on models with a Phoenix BIOS. The System Management Mode 1249 is used to set the BIOS and power saving options on Toshiba portables. 1250 1251 For information on utilities to make use of this driver see the 1252 Toshiba Linux utilities web site at: 1253 <http://www.buzzard.org.uk/toshiba/>. 1254 1255 Say Y if you intend to run this kernel on a Toshiba portable. 1256 Say N otherwise. 1257 1258config I8K 1259 tristate "Dell i8k legacy laptop support" 1260 select HWMON 1261 select SENSORS_DELL_SMM 1262 ---help--- 1263 This option enables legacy /proc/i8k userspace interface in hwmon 1264 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1265 temperature and allows controlling fan speeds of Dell laptops via 1266 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1267 it reports also power and hotkey status. For fan speed control is 1268 needed userspace package i8kutils. 1269 1270 Say Y if you intend to run this kernel on old Dell laptops or want to 1271 use userspace package i8kutils. 1272 Say N otherwise. 1273 1274config X86_REBOOTFIXUPS 1275 bool "Enable X86 board specific fixups for reboot" 1276 depends on X86_32 1277 ---help--- 1278 This enables chipset and/or board specific fixups to be done 1279 in order to get reboot to work correctly. This is only needed on 1280 some combinations of hardware and BIOS. The symptom, for which 1281 this config is intended, is when reboot ends with a stalled/hung 1282 system. 1283 1284 Currently, the only fixup is for the Geode machines using 1285 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1286 1287 Say Y if you want to enable the fixup. Currently, it's safe to 1288 enable this option even if you don't need it. 1289 Say N otherwise. 1290 1291config MICROCODE 1292 bool "CPU microcode loading support" 1293 default y 1294 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1295 select FW_LOADER 1296 ---help--- 1297 If you say Y here, you will be able to update the microcode on 1298 Intel and AMD processors. The Intel support is for the IA32 family, 1299 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1300 AMD support is for families 0x10 and later. You will obviously need 1301 the actual microcode binary data itself which is not shipped with 1302 the Linux kernel. 1303 1304 The preferred method to load microcode from a detached initrd is described 1305 in Documentation/x86/microcode.txt. For that you need to enable 1306 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1307 initrd for microcode blobs. 1308 1309 In addition, you can build the microcode into the kernel. For that you 1310 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1311 config option. 1312 1313config MICROCODE_INTEL 1314 bool "Intel microcode loading support" 1315 depends on MICROCODE 1316 default MICROCODE 1317 select FW_LOADER 1318 ---help--- 1319 This options enables microcode patch loading support for Intel 1320 processors. 1321 1322 For the current Intel microcode data package go to 1323 <https://downloadcenter.intel.com> and search for 1324 'Linux Processor Microcode Data File'. 1325 1326config MICROCODE_AMD 1327 bool "AMD microcode loading support" 1328 depends on MICROCODE 1329 select FW_LOADER 1330 ---help--- 1331 If you select this option, microcode patch loading support for AMD 1332 processors will be enabled. 1333 1334config MICROCODE_OLD_INTERFACE 1335 def_bool y 1336 depends on MICROCODE 1337 1338config X86_MSR 1339 tristate "/dev/cpu/*/msr - Model-specific register support" 1340 ---help--- 1341 This device gives privileged processes access to the x86 1342 Model-Specific Registers (MSRs). It is a character device with 1343 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1344 MSR accesses are directed to a specific CPU on multi-processor 1345 systems. 1346 1347config X86_CPUID 1348 tristate "/dev/cpu/*/cpuid - CPU information support" 1349 ---help--- 1350 This device gives processes access to the x86 CPUID instruction to 1351 be executed on a specific processor. It is a character device 1352 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1353 /dev/cpu/31/cpuid. 1354 1355choice 1356 prompt "High Memory Support" 1357 default HIGHMEM4G 1358 depends on X86_32 1359 1360config NOHIGHMEM 1361 bool "off" 1362 ---help--- 1363 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1364 However, the address space of 32-bit x86 processors is only 4 1365 Gigabytes large. That means that, if you have a large amount of 1366 physical memory, not all of it can be "permanently mapped" by the 1367 kernel. The physical memory that's not permanently mapped is called 1368 "high memory". 1369 1370 If you are compiling a kernel which will never run on a machine with 1371 more than 1 Gigabyte total physical RAM, answer "off" here (default 1372 choice and suitable for most users). This will result in a "3GB/1GB" 1373 split: 3GB are mapped so that each process sees a 3GB virtual memory 1374 space and the remaining part of the 4GB virtual memory space is used 1375 by the kernel to permanently map as much physical memory as 1376 possible. 1377 1378 If the machine has between 1 and 4 Gigabytes physical RAM, then 1379 answer "4GB" here. 1380 1381 If more than 4 Gigabytes is used then answer "64GB" here. This 1382 selection turns Intel PAE (Physical Address Extension) mode on. 1383 PAE implements 3-level paging on IA32 processors. PAE is fully 1384 supported by Linux, PAE mode is implemented on all recent Intel 1385 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1386 then the kernel will not boot on CPUs that don't support PAE! 1387 1388 The actual amount of total physical memory will either be 1389 auto detected or can be forced by using a kernel command line option 1390 such as "mem=256M". (Try "man bootparam" or see the documentation of 1391 your boot loader (lilo or loadlin) about how to pass options to the 1392 kernel at boot time.) 1393 1394 If unsure, say "off". 1395 1396config HIGHMEM4G 1397 bool "4GB" 1398 ---help--- 1399 Select this if you have a 32-bit processor and between 1 and 4 1400 gigabytes of physical RAM. 1401 1402config HIGHMEM64G 1403 bool "64GB" 1404 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1405 select X86_PAE 1406 ---help--- 1407 Select this if you have a 32-bit processor and more than 4 1408 gigabytes of physical RAM. 1409 1410endchoice 1411 1412choice 1413 prompt "Memory split" if EXPERT 1414 default VMSPLIT_3G 1415 depends on X86_32 1416 ---help--- 1417 Select the desired split between kernel and user memory. 1418 1419 If the address range available to the kernel is less than the 1420 physical memory installed, the remaining memory will be available 1421 as "high memory". Accessing high memory is a little more costly 1422 than low memory, as it needs to be mapped into the kernel first. 1423 Note that increasing the kernel address space limits the range 1424 available to user programs, making the address space there 1425 tighter. Selecting anything other than the default 3G/1G split 1426 will also likely make your kernel incompatible with binary-only 1427 kernel modules. 1428 1429 If you are not absolutely sure what you are doing, leave this 1430 option alone! 1431 1432 config VMSPLIT_3G 1433 bool "3G/1G user/kernel split" 1434 config VMSPLIT_3G_OPT 1435 depends on !X86_PAE 1436 bool "3G/1G user/kernel split (for full 1G low memory)" 1437 config VMSPLIT_2G 1438 bool "2G/2G user/kernel split" 1439 config VMSPLIT_2G_OPT 1440 depends on !X86_PAE 1441 bool "2G/2G user/kernel split (for full 2G low memory)" 1442 config VMSPLIT_1G 1443 bool "1G/3G user/kernel split" 1444endchoice 1445 1446config PAGE_OFFSET 1447 hex 1448 default 0xB0000000 if VMSPLIT_3G_OPT 1449 default 0x80000000 if VMSPLIT_2G 1450 default 0x78000000 if VMSPLIT_2G_OPT 1451 default 0x40000000 if VMSPLIT_1G 1452 default 0xC0000000 1453 depends on X86_32 1454 1455config HIGHMEM 1456 def_bool y 1457 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1458 1459config X86_PAE 1460 bool "PAE (Physical Address Extension) Support" 1461 depends on X86_32 && !HIGHMEM4G 1462 select PHYS_ADDR_T_64BIT 1463 select SWIOTLB 1464 ---help--- 1465 PAE is required for NX support, and furthermore enables 1466 larger swapspace support for non-overcommit purposes. It 1467 has the cost of more pagetable lookup overhead, and also 1468 consumes more pagetable space per process. 1469 1470config X86_5LEVEL 1471 bool "Enable 5-level page tables support" 1472 select DYNAMIC_MEMORY_LAYOUT 1473 select SPARSEMEM_VMEMMAP 1474 depends on X86_64 1475 ---help--- 1476 5-level paging enables access to larger address space: 1477 upto 128 PiB of virtual address space and 4 PiB of 1478 physical address space. 1479 1480 It will be supported by future Intel CPUs. 1481 1482 A kernel with the option enabled can be booted on machines that 1483 support 4- or 5-level paging. 1484 1485 See Documentation/x86/x86_64/5level-paging.txt for more 1486 information. 1487 1488 Say N if unsure. 1489 1490config X86_DIRECT_GBPAGES 1491 def_bool y 1492 depends on X86_64 && !DEBUG_PAGEALLOC 1493 ---help--- 1494 Certain kernel features effectively disable kernel 1495 linear 1 GB mappings (even if the CPU otherwise 1496 supports them), so don't confuse the user by printing 1497 that we have them enabled. 1498 1499config X86_CPA_STATISTICS 1500 bool "Enable statistic for Change Page Attribute" 1501 depends on DEBUG_FS 1502 ---help--- 1503 Expose statistics about the Change Page Attribute mechanims, which 1504 helps to determine the effectivness of preserving large and huge 1505 page mappings when mapping protections are changed. 1506 1507config ARCH_HAS_MEM_ENCRYPT 1508 def_bool y 1509 1510config AMD_MEM_ENCRYPT 1511 bool "AMD Secure Memory Encryption (SME) support" 1512 depends on X86_64 && CPU_SUP_AMD 1513 select DYNAMIC_PHYSICAL_MASK 1514 ---help--- 1515 Say yes to enable support for the encryption of system memory. 1516 This requires an AMD processor that supports Secure Memory 1517 Encryption (SME). 1518 1519config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1520 bool "Activate AMD Secure Memory Encryption (SME) by default" 1521 default y 1522 depends on AMD_MEM_ENCRYPT 1523 ---help--- 1524 Say yes to have system memory encrypted by default if running on 1525 an AMD processor that supports Secure Memory Encryption (SME). 1526 1527 If set to Y, then the encryption of system memory can be 1528 deactivated with the mem_encrypt=off command line option. 1529 1530 If set to N, then the encryption of system memory can be 1531 activated with the mem_encrypt=on command line option. 1532 1533config ARCH_USE_MEMREMAP_PROT 1534 def_bool y 1535 depends on AMD_MEM_ENCRYPT 1536 1537# Common NUMA Features 1538config NUMA 1539 bool "Numa Memory Allocation and Scheduler Support" 1540 depends on SMP 1541 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1542 default y if X86_BIGSMP 1543 ---help--- 1544 Enable NUMA (Non Uniform Memory Access) support. 1545 1546 The kernel will try to allocate memory used by a CPU on the 1547 local memory controller of the CPU and add some more 1548 NUMA awareness to the kernel. 1549 1550 For 64-bit this is recommended if the system is Intel Core i7 1551 (or later), AMD Opteron, or EM64T NUMA. 1552 1553 For 32-bit this is only needed if you boot a 32-bit 1554 kernel on a 64-bit NUMA platform. 1555 1556 Otherwise, you should say N. 1557 1558config AMD_NUMA 1559 def_bool y 1560 prompt "Old style AMD Opteron NUMA detection" 1561 depends on X86_64 && NUMA && PCI 1562 ---help--- 1563 Enable AMD NUMA node topology detection. You should say Y here if 1564 you have a multi processor AMD system. This uses an old method to 1565 read the NUMA configuration directly from the builtin Northbridge 1566 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1567 which also takes priority if both are compiled in. 1568 1569config X86_64_ACPI_NUMA 1570 def_bool y 1571 prompt "ACPI NUMA detection" 1572 depends on X86_64 && NUMA && ACPI && PCI 1573 select ACPI_NUMA 1574 ---help--- 1575 Enable ACPI SRAT based node topology detection. 1576 1577# Some NUMA nodes have memory ranges that span 1578# other nodes. Even though a pfn is valid and 1579# between a node's start and end pfns, it may not 1580# reside on that node. See memmap_init_zone() 1581# for details. 1582config NODES_SPAN_OTHER_NODES 1583 def_bool y 1584 depends on X86_64_ACPI_NUMA 1585 1586config NUMA_EMU 1587 bool "NUMA emulation" 1588 depends on NUMA 1589 ---help--- 1590 Enable NUMA emulation. A flat machine will be split 1591 into virtual nodes when booted with "numa=fake=N", where N is the 1592 number of nodes. This is only useful for debugging. 1593 1594config NODES_SHIFT 1595 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1596 range 1 10 1597 default "10" if MAXSMP 1598 default "6" if X86_64 1599 default "3" 1600 depends on NEED_MULTIPLE_NODES 1601 ---help--- 1602 Specify the maximum number of NUMA Nodes available on the target 1603 system. Increases memory reserved to accommodate various tables. 1604 1605config ARCH_HAVE_MEMORY_PRESENT 1606 def_bool y 1607 depends on X86_32 && DISCONTIGMEM 1608 1609config ARCH_FLATMEM_ENABLE 1610 def_bool y 1611 depends on X86_32 && !NUMA 1612 1613config ARCH_DISCONTIGMEM_ENABLE 1614 def_bool y 1615 depends on NUMA && X86_32 1616 1617config ARCH_DISCONTIGMEM_DEFAULT 1618 def_bool y 1619 depends on NUMA && X86_32 1620 1621config ARCH_SPARSEMEM_ENABLE 1622 def_bool y 1623 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1624 select SPARSEMEM_STATIC if X86_32 1625 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1626 1627config ARCH_SPARSEMEM_DEFAULT 1628 def_bool y 1629 depends on X86_64 1630 1631config ARCH_SELECT_MEMORY_MODEL 1632 def_bool y 1633 depends on ARCH_SPARSEMEM_ENABLE 1634 1635config ARCH_MEMORY_PROBE 1636 bool "Enable sysfs memory/probe interface" 1637 depends on X86_64 && MEMORY_HOTPLUG 1638 help 1639 This option enables a sysfs memory/probe interface for testing. 1640 See Documentation/memory-hotplug.txt for more information. 1641 If you are unsure how to answer this question, answer N. 1642 1643config ARCH_PROC_KCORE_TEXT 1644 def_bool y 1645 depends on X86_64 && PROC_KCORE 1646 1647config ILLEGAL_POINTER_VALUE 1648 hex 1649 default 0 if X86_32 1650 default 0xdead000000000000 if X86_64 1651 1652config X86_PMEM_LEGACY_DEVICE 1653 bool 1654 1655config X86_PMEM_LEGACY 1656 tristate "Support non-standard NVDIMMs and ADR protected memory" 1657 depends on PHYS_ADDR_T_64BIT 1658 depends on BLK_DEV 1659 select X86_PMEM_LEGACY_DEVICE 1660 select LIBNVDIMM 1661 help 1662 Treat memory marked using the non-standard e820 type of 12 as used 1663 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1664 The kernel will offer these regions to the 'pmem' driver so 1665 they can be used for persistent storage. 1666 1667 Say Y if unsure. 1668 1669config HIGHPTE 1670 bool "Allocate 3rd-level pagetables from highmem" 1671 depends on HIGHMEM 1672 ---help--- 1673 The VM uses one page table entry for each page of physical memory. 1674 For systems with a lot of RAM, this can be wasteful of precious 1675 low memory. Setting this option will put user-space page table 1676 entries in high memory. 1677 1678config X86_CHECK_BIOS_CORRUPTION 1679 bool "Check for low memory corruption" 1680 ---help--- 1681 Periodically check for memory corruption in low memory, which 1682 is suspected to be caused by BIOS. Even when enabled in the 1683 configuration, it is disabled at runtime. Enable it by 1684 setting "memory_corruption_check=1" on the kernel command 1685 line. By default it scans the low 64k of memory every 60 1686 seconds; see the memory_corruption_check_size and 1687 memory_corruption_check_period parameters in 1688 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1689 1690 When enabled with the default parameters, this option has 1691 almost no overhead, as it reserves a relatively small amount 1692 of memory and scans it infrequently. It both detects corruption 1693 and prevents it from affecting the running system. 1694 1695 It is, however, intended as a diagnostic tool; if repeatable 1696 BIOS-originated corruption always affects the same memory, 1697 you can use memmap= to prevent the kernel from using that 1698 memory. 1699 1700config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1701 bool "Set the default setting of memory_corruption_check" 1702 depends on X86_CHECK_BIOS_CORRUPTION 1703 default y 1704 ---help--- 1705 Set whether the default state of memory_corruption_check is 1706 on or off. 1707 1708config X86_RESERVE_LOW 1709 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1710 default 64 1711 range 4 640 1712 ---help--- 1713 Specify the amount of low memory to reserve for the BIOS. 1714 1715 The first page contains BIOS data structures that the kernel 1716 must not use, so that page must always be reserved. 1717 1718 By default we reserve the first 64K of physical RAM, as a 1719 number of BIOSes are known to corrupt that memory range 1720 during events such as suspend/resume or monitor cable 1721 insertion, so it must not be used by the kernel. 1722 1723 You can set this to 4 if you are absolutely sure that you 1724 trust the BIOS to get all its memory reservations and usages 1725 right. If you know your BIOS have problems beyond the 1726 default 64K area, you can set this to 640 to avoid using the 1727 entire low memory range. 1728 1729 If you have doubts about the BIOS (e.g. suspend/resume does 1730 not work or there's kernel crashes after certain hardware 1731 hotplug events) then you might want to enable 1732 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1733 typical corruption patterns. 1734 1735 Leave this to the default value of 64 if you are unsure. 1736 1737config MATH_EMULATION 1738 bool 1739 depends on MODIFY_LDT_SYSCALL 1740 prompt "Math emulation" if X86_32 1741 ---help--- 1742 Linux can emulate a math coprocessor (used for floating point 1743 operations) if you don't have one. 486DX and Pentium processors have 1744 a math coprocessor built in, 486SX and 386 do not, unless you added 1745 a 487DX or 387, respectively. (The messages during boot time can 1746 give you some hints here ["man dmesg"].) Everyone needs either a 1747 coprocessor or this emulation. 1748 1749 If you don't have a math coprocessor, you need to say Y here; if you 1750 say Y here even though you have a coprocessor, the coprocessor will 1751 be used nevertheless. (This behavior can be changed with the kernel 1752 command line option "no387", which comes handy if your coprocessor 1753 is broken. Try "man bootparam" or see the documentation of your boot 1754 loader (lilo or loadlin) about how to pass options to the kernel at 1755 boot time.) This means that it is a good idea to say Y here if you 1756 intend to use this kernel on different machines. 1757 1758 More information about the internals of the Linux math coprocessor 1759 emulation can be found in <file:arch/x86/math-emu/README>. 1760 1761 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1762 kernel, it won't hurt. 1763 1764config MTRR 1765 def_bool y 1766 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1767 ---help--- 1768 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1769 the Memory Type Range Registers (MTRRs) may be used to control 1770 processor access to memory ranges. This is most useful if you have 1771 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1772 allows bus write transfers to be combined into a larger transfer 1773 before bursting over the PCI/AGP bus. This can increase performance 1774 of image write operations 2.5 times or more. Saying Y here creates a 1775 /proc/mtrr file which may be used to manipulate your processor's 1776 MTRRs. Typically the X server should use this. 1777 1778 This code has a reasonably generic interface so that similar 1779 control registers on other processors can be easily supported 1780 as well: 1781 1782 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1783 Registers (ARRs) which provide a similar functionality to MTRRs. For 1784 these, the ARRs are used to emulate the MTRRs. 1785 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1786 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1787 write-combining. All of these processors are supported by this code 1788 and it makes sense to say Y here if you have one of them. 1789 1790 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1791 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1792 can lead to all sorts of problems, so it's good to say Y here. 1793 1794 You can safely say Y even if your machine doesn't have MTRRs, you'll 1795 just add about 9 KB to your kernel. 1796 1797 See <file:Documentation/x86/mtrr.txt> for more information. 1798 1799config MTRR_SANITIZER 1800 def_bool y 1801 prompt "MTRR cleanup support" 1802 depends on MTRR 1803 ---help--- 1804 Convert MTRR layout from continuous to discrete, so X drivers can 1805 add writeback entries. 1806 1807 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1808 The largest mtrr entry size for a continuous block can be set with 1809 mtrr_chunk_size. 1810 1811 If unsure, say Y. 1812 1813config MTRR_SANITIZER_ENABLE_DEFAULT 1814 int "MTRR cleanup enable value (0-1)" 1815 range 0 1 1816 default "0" 1817 depends on MTRR_SANITIZER 1818 ---help--- 1819 Enable mtrr cleanup default value 1820 1821config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1822 int "MTRR cleanup spare reg num (0-7)" 1823 range 0 7 1824 default "1" 1825 depends on MTRR_SANITIZER 1826 ---help--- 1827 mtrr cleanup spare entries default, it can be changed via 1828 mtrr_spare_reg_nr=N on the kernel command line. 1829 1830config X86_PAT 1831 def_bool y 1832 prompt "x86 PAT support" if EXPERT 1833 depends on MTRR 1834 ---help--- 1835 Use PAT attributes to setup page level cache control. 1836 1837 PATs are the modern equivalents of MTRRs and are much more 1838 flexible than MTRRs. 1839 1840 Say N here if you see bootup problems (boot crash, boot hang, 1841 spontaneous reboots) or a non-working video driver. 1842 1843 If unsure, say Y. 1844 1845config ARCH_USES_PG_UNCACHED 1846 def_bool y 1847 depends on X86_PAT 1848 1849config ARCH_RANDOM 1850 def_bool y 1851 prompt "x86 architectural random number generator" if EXPERT 1852 ---help--- 1853 Enable the x86 architectural RDRAND instruction 1854 (Intel Bull Mountain technology) to generate random numbers. 1855 If supported, this is a high bandwidth, cryptographically 1856 secure hardware random number generator. 1857 1858config X86_SMAP 1859 def_bool y 1860 prompt "Supervisor Mode Access Prevention" if EXPERT 1861 ---help--- 1862 Supervisor Mode Access Prevention (SMAP) is a security 1863 feature in newer Intel processors. There is a small 1864 performance cost if this enabled and turned on; there is 1865 also a small increase in the kernel size if this is enabled. 1866 1867 If unsure, say Y. 1868 1869config X86_INTEL_UMIP 1870 def_bool y 1871 depends on CPU_SUP_INTEL 1872 prompt "Intel User Mode Instruction Prevention" if EXPERT 1873 ---help--- 1874 The User Mode Instruction Prevention (UMIP) is a security 1875 feature in newer Intel processors. If enabled, a general 1876 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1877 or STR instructions are executed in user mode. These instructions 1878 unnecessarily expose information about the hardware state. 1879 1880 The vast majority of applications do not use these instructions. 1881 For the very few that do, software emulation is provided in 1882 specific cases in protected and virtual-8086 modes. Emulated 1883 results are dummy. 1884 1885config X86_INTEL_MPX 1886 prompt "Intel MPX (Memory Protection Extensions)" 1887 def_bool n 1888 # Note: only available in 64-bit mode due to VMA flags shortage 1889 depends on CPU_SUP_INTEL && X86_64 1890 select ARCH_USES_HIGH_VMA_FLAGS 1891 ---help--- 1892 MPX provides hardware features that can be used in 1893 conjunction with compiler-instrumented code to check 1894 memory references. It is designed to detect buffer 1895 overflow or underflow bugs. 1896 1897 This option enables running applications which are 1898 instrumented or otherwise use MPX. It does not use MPX 1899 itself inside the kernel or to protect the kernel 1900 against bad memory references. 1901 1902 Enabling this option will make the kernel larger: 1903 ~8k of kernel text and 36 bytes of data on a 64-bit 1904 defconfig. It adds a long to the 'mm_struct' which 1905 will increase the kernel memory overhead of each 1906 process and adds some branches to paths used during 1907 exec() and munmap(). 1908 1909 For details, see Documentation/x86/intel_mpx.txt 1910 1911 If unsure, say N. 1912 1913config X86_INTEL_MEMORY_PROTECTION_KEYS 1914 prompt "Intel Memory Protection Keys" 1915 def_bool y 1916 # Note: only available in 64-bit mode 1917 depends on CPU_SUP_INTEL && X86_64 1918 select ARCH_USES_HIGH_VMA_FLAGS 1919 select ARCH_HAS_PKEYS 1920 ---help--- 1921 Memory Protection Keys provides a mechanism for enforcing 1922 page-based protections, but without requiring modification of the 1923 page tables when an application changes protection domains. 1924 1925 For details, see Documentation/x86/protection-keys.txt 1926 1927 If unsure, say y. 1928 1929config EFI 1930 bool "EFI runtime service support" 1931 depends on ACPI 1932 select UCS2_STRING 1933 select EFI_RUNTIME_WRAPPERS 1934 ---help--- 1935 This enables the kernel to use EFI runtime services that are 1936 available (such as the EFI variable services). 1937 1938 This option is only useful on systems that have EFI firmware. 1939 In addition, you should use the latest ELILO loader available 1940 at <http://elilo.sourceforge.net> in order to take advantage 1941 of EFI runtime services. However, even with this option, the 1942 resultant kernel should continue to boot on existing non-EFI 1943 platforms. 1944 1945config EFI_STUB 1946 bool "EFI stub support" 1947 depends on EFI && !X86_USE_3DNOW 1948 select RELOCATABLE 1949 ---help--- 1950 This kernel feature allows a bzImage to be loaded directly 1951 by EFI firmware without the use of a bootloader. 1952 1953 See Documentation/efi-stub.txt for more information. 1954 1955config EFI_MIXED 1956 bool "EFI mixed-mode support" 1957 depends on EFI_STUB && X86_64 1958 ---help--- 1959 Enabling this feature allows a 64-bit kernel to be booted 1960 on a 32-bit firmware, provided that your CPU supports 64-bit 1961 mode. 1962 1963 Note that it is not possible to boot a mixed-mode enabled 1964 kernel via the EFI boot stub - a bootloader that supports 1965 the EFI handover protocol must be used. 1966 1967 If unsure, say N. 1968 1969config SECCOMP 1970 def_bool y 1971 prompt "Enable seccomp to safely compute untrusted bytecode" 1972 ---help--- 1973 This kernel feature is useful for number crunching applications 1974 that may need to compute untrusted bytecode during their 1975 execution. By using pipes or other transports made available to 1976 the process as file descriptors supporting the read/write 1977 syscalls, it's possible to isolate those applications in 1978 their own address space using seccomp. Once seccomp is 1979 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1980 and the task is only allowed to execute a few safe syscalls 1981 defined by each seccomp mode. 1982 1983 If unsure, say Y. Only embedded should say N here. 1984 1985source "kernel/Kconfig.hz" 1986 1987config KEXEC 1988 bool "kexec system call" 1989 select KEXEC_CORE 1990 ---help--- 1991 kexec is a system call that implements the ability to shutdown your 1992 current kernel, and to start another kernel. It is like a reboot 1993 but it is independent of the system firmware. And like a reboot 1994 you can start any kernel with it, not just Linux. 1995 1996 The name comes from the similarity to the exec system call. 1997 1998 It is an ongoing process to be certain the hardware in a machine 1999 is properly shutdown, so do not be surprised if this code does not 2000 initially work for you. As of this writing the exact hardware 2001 interface is strongly in flux, so no good recommendation can be 2002 made. 2003 2004config KEXEC_FILE 2005 bool "kexec file based system call" 2006 select KEXEC_CORE 2007 select BUILD_BIN2C 2008 depends on X86_64 2009 depends on CRYPTO=y 2010 depends on CRYPTO_SHA256=y 2011 ---help--- 2012 This is new version of kexec system call. This system call is 2013 file based and takes file descriptors as system call argument 2014 for kernel and initramfs as opposed to list of segments as 2015 accepted by previous system call. 2016 2017config ARCH_HAS_KEXEC_PURGATORY 2018 def_bool KEXEC_FILE 2019 2020config KEXEC_VERIFY_SIG 2021 bool "Verify kernel signature during kexec_file_load() syscall" 2022 depends on KEXEC_FILE 2023 ---help--- 2024 This option makes kernel signature verification mandatory for 2025 the kexec_file_load() syscall. 2026 2027 In addition to that option, you need to enable signature 2028 verification for the corresponding kernel image type being 2029 loaded in order for this to work. 2030 2031config KEXEC_BZIMAGE_VERIFY_SIG 2032 bool "Enable bzImage signature verification support" 2033 depends on KEXEC_VERIFY_SIG 2034 depends on SIGNED_PE_FILE_VERIFICATION 2035 select SYSTEM_TRUSTED_KEYRING 2036 ---help--- 2037 Enable bzImage signature verification support. 2038 2039config CRASH_DUMP 2040 bool "kernel crash dumps" 2041 depends on X86_64 || (X86_32 && HIGHMEM) 2042 ---help--- 2043 Generate crash dump after being started by kexec. 2044 This should be normally only set in special crash dump kernels 2045 which are loaded in the main kernel with kexec-tools into 2046 a specially reserved region and then later executed after 2047 a crash by kdump/kexec. The crash dump kernel must be compiled 2048 to a memory address not used by the main kernel or BIOS using 2049 PHYSICAL_START, or it must be built as a relocatable image 2050 (CONFIG_RELOCATABLE=y). 2051 For more details see Documentation/kdump/kdump.txt 2052 2053config KEXEC_JUMP 2054 bool "kexec jump" 2055 depends on KEXEC && HIBERNATION 2056 ---help--- 2057 Jump between original kernel and kexeced kernel and invoke 2058 code in physical address mode via KEXEC 2059 2060config PHYSICAL_START 2061 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2062 default "0x1000000" 2063 ---help--- 2064 This gives the physical address where the kernel is loaded. 2065 2066 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2067 bzImage will decompress itself to above physical address and 2068 run from there. Otherwise, bzImage will run from the address where 2069 it has been loaded by the boot loader and will ignore above physical 2070 address. 2071 2072 In normal kdump cases one does not have to set/change this option 2073 as now bzImage can be compiled as a completely relocatable image 2074 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2075 address. This option is mainly useful for the folks who don't want 2076 to use a bzImage for capturing the crash dump and want to use a 2077 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2078 to be specifically compiled to run from a specific memory area 2079 (normally a reserved region) and this option comes handy. 2080 2081 So if you are using bzImage for capturing the crash dump, 2082 leave the value here unchanged to 0x1000000 and set 2083 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2084 for capturing the crash dump change this value to start of 2085 the reserved region. In other words, it can be set based on 2086 the "X" value as specified in the "crashkernel=YM@XM" 2087 command line boot parameter passed to the panic-ed 2088 kernel. Please take a look at Documentation/kdump/kdump.txt 2089 for more details about crash dumps. 2090 2091 Usage of bzImage for capturing the crash dump is recommended as 2092 one does not have to build two kernels. Same kernel can be used 2093 as production kernel and capture kernel. Above option should have 2094 gone away after relocatable bzImage support is introduced. But it 2095 is present because there are users out there who continue to use 2096 vmlinux for dump capture. This option should go away down the 2097 line. 2098 2099 Don't change this unless you know what you are doing. 2100 2101config RELOCATABLE 2102 bool "Build a relocatable kernel" 2103 default y 2104 ---help--- 2105 This builds a kernel image that retains relocation information 2106 so it can be loaded someplace besides the default 1MB. 2107 The relocations tend to make the kernel binary about 10% larger, 2108 but are discarded at runtime. 2109 2110 One use is for the kexec on panic case where the recovery kernel 2111 must live at a different physical address than the primary 2112 kernel. 2113 2114 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2115 it has been loaded at and the compile time physical address 2116 (CONFIG_PHYSICAL_START) is used as the minimum location. 2117 2118config RANDOMIZE_BASE 2119 bool "Randomize the address of the kernel image (KASLR)" 2120 depends on RELOCATABLE 2121 default y 2122 ---help--- 2123 In support of Kernel Address Space Layout Randomization (KASLR), 2124 this randomizes the physical address at which the kernel image 2125 is decompressed and the virtual address where the kernel 2126 image is mapped, as a security feature that deters exploit 2127 attempts relying on knowledge of the location of kernel 2128 code internals. 2129 2130 On 64-bit, the kernel physical and virtual addresses are 2131 randomized separately. The physical address will be anywhere 2132 between 16MB and the top of physical memory (up to 64TB). The 2133 virtual address will be randomized from 16MB up to 1GB (9 bits 2134 of entropy). Note that this also reduces the memory space 2135 available to kernel modules from 1.5GB to 1GB. 2136 2137 On 32-bit, the kernel physical and virtual addresses are 2138 randomized together. They will be randomized from 16MB up to 2139 512MB (8 bits of entropy). 2140 2141 Entropy is generated using the RDRAND instruction if it is 2142 supported. If RDTSC is supported, its value is mixed into 2143 the entropy pool as well. If neither RDRAND nor RDTSC are 2144 supported, then entropy is read from the i8254 timer. The 2145 usable entropy is limited by the kernel being built using 2146 2GB addressing, and that PHYSICAL_ALIGN must be at a 2147 minimum of 2MB. As a result, only 10 bits of entropy are 2148 theoretically possible, but the implementations are further 2149 limited due to memory layouts. 2150 2151 If unsure, say Y. 2152 2153# Relocation on x86 needs some additional build support 2154config X86_NEED_RELOCS 2155 def_bool y 2156 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2157 2158config PHYSICAL_ALIGN 2159 hex "Alignment value to which kernel should be aligned" 2160 default "0x200000" 2161 range 0x2000 0x1000000 if X86_32 2162 range 0x200000 0x1000000 if X86_64 2163 ---help--- 2164 This value puts the alignment restrictions on physical address 2165 where kernel is loaded and run from. Kernel is compiled for an 2166 address which meets above alignment restriction. 2167 2168 If bootloader loads the kernel at a non-aligned address and 2169 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2170 address aligned to above value and run from there. 2171 2172 If bootloader loads the kernel at a non-aligned address and 2173 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2174 load address and decompress itself to the address it has been 2175 compiled for and run from there. The address for which kernel is 2176 compiled already meets above alignment restrictions. Hence the 2177 end result is that kernel runs from a physical address meeting 2178 above alignment restrictions. 2179 2180 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2181 this value must be a multiple of 0x200000. 2182 2183 Don't change this unless you know what you are doing. 2184 2185config DYNAMIC_MEMORY_LAYOUT 2186 bool 2187 ---help--- 2188 This option makes base addresses of vmalloc and vmemmap as well as 2189 __PAGE_OFFSET movable during boot. 2190 2191config RANDOMIZE_MEMORY 2192 bool "Randomize the kernel memory sections" 2193 depends on X86_64 2194 depends on RANDOMIZE_BASE 2195 select DYNAMIC_MEMORY_LAYOUT 2196 default RANDOMIZE_BASE 2197 ---help--- 2198 Randomizes the base virtual address of kernel memory sections 2199 (physical memory mapping, vmalloc & vmemmap). This security feature 2200 makes exploits relying on predictable memory locations less reliable. 2201 2202 The order of allocations remains unchanged. Entropy is generated in 2203 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2204 configuration have in average 30,000 different possible virtual 2205 addresses for each memory section. 2206 2207 If unsure, say Y. 2208 2209config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2210 hex "Physical memory mapping padding" if EXPERT 2211 depends on RANDOMIZE_MEMORY 2212 default "0xa" if MEMORY_HOTPLUG 2213 default "0x0" 2214 range 0x1 0x40 if MEMORY_HOTPLUG 2215 range 0x0 0x40 2216 ---help--- 2217 Define the padding in terabytes added to the existing physical 2218 memory size during kernel memory randomization. It is useful 2219 for memory hotplug support but reduces the entropy available for 2220 address randomization. 2221 2222 If unsure, leave at the default value. 2223 2224config HOTPLUG_CPU 2225 bool "Support for hot-pluggable CPUs" 2226 depends on SMP 2227 ---help--- 2228 Say Y here to allow turning CPUs off and on. CPUs can be 2229 controlled through /sys/devices/system/cpu. 2230 ( Note: power management support will enable this option 2231 automatically on SMP systems. ) 2232 Say N if you want to disable CPU hotplug. 2233 2234config BOOTPARAM_HOTPLUG_CPU0 2235 bool "Set default setting of cpu0_hotpluggable" 2236 depends on HOTPLUG_CPU 2237 ---help--- 2238 Set whether default state of cpu0_hotpluggable is on or off. 2239 2240 Say Y here to enable CPU0 hotplug by default. If this switch 2241 is turned on, there is no need to give cpu0_hotplug kernel 2242 parameter and the CPU0 hotplug feature is enabled by default. 2243 2244 Please note: there are two known CPU0 dependencies if you want 2245 to enable the CPU0 hotplug feature either by this switch or by 2246 cpu0_hotplug kernel parameter. 2247 2248 First, resume from hibernate or suspend always starts from CPU0. 2249 So hibernate and suspend are prevented if CPU0 is offline. 2250 2251 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2252 offline if any interrupt can not migrate out of CPU0. There may 2253 be other CPU0 dependencies. 2254 2255 Please make sure the dependencies are under your control before 2256 you enable this feature. 2257 2258 Say N if you don't want to enable CPU0 hotplug feature by default. 2259 You still can enable the CPU0 hotplug feature at boot by kernel 2260 parameter cpu0_hotplug. 2261 2262config DEBUG_HOTPLUG_CPU0 2263 def_bool n 2264 prompt "Debug CPU0 hotplug" 2265 depends on HOTPLUG_CPU 2266 ---help--- 2267 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2268 soon as possible and boots up userspace with CPU0 offlined. User 2269 can online CPU0 back after boot time. 2270 2271 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2272 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2273 compilation or giving cpu0_hotplug kernel parameter at boot. 2274 2275 If unsure, say N. 2276 2277config COMPAT_VDSO 2278 def_bool n 2279 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2280 depends on COMPAT_32 2281 ---help--- 2282 Certain buggy versions of glibc will crash if they are 2283 presented with a 32-bit vDSO that is not mapped at the address 2284 indicated in its segment table. 2285 2286 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2287 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2288 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2289 the only released version with the bug, but OpenSUSE 9 2290 contains a buggy "glibc 2.3.2". 2291 2292 The symptom of the bug is that everything crashes on startup, saying: 2293 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2294 2295 Saying Y here changes the default value of the vdso32 boot 2296 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2297 This works around the glibc bug but hurts performance. 2298 2299 If unsure, say N: if you are compiling your own kernel, you 2300 are unlikely to be using a buggy version of glibc. 2301 2302choice 2303 prompt "vsyscall table for legacy applications" 2304 depends on X86_64 2305 default LEGACY_VSYSCALL_EMULATE 2306 help 2307 Legacy user code that does not know how to find the vDSO expects 2308 to be able to issue three syscalls by calling fixed addresses in 2309 kernel space. Since this location is not randomized with ASLR, 2310 it can be used to assist security vulnerability exploitation. 2311 2312 This setting can be changed at boot time via the kernel command 2313 line parameter vsyscall=[emulate|none]. 2314 2315 On a system with recent enough glibc (2.14 or newer) and no 2316 static binaries, you can say None without a performance penalty 2317 to improve security. 2318 2319 If unsure, select "Emulate". 2320 2321 config LEGACY_VSYSCALL_EMULATE 2322 bool "Emulate" 2323 help 2324 The kernel traps and emulates calls into the fixed 2325 vsyscall address mapping. This makes the mapping 2326 non-executable, but it still contains known contents, 2327 which could be used in certain rare security vulnerability 2328 exploits. This configuration is recommended when userspace 2329 still uses the vsyscall area. 2330 2331 config LEGACY_VSYSCALL_NONE 2332 bool "None" 2333 help 2334 There will be no vsyscall mapping at all. This will 2335 eliminate any risk of ASLR bypass due to the vsyscall 2336 fixed address mapping. Attempts to use the vsyscalls 2337 will be reported to dmesg, so that either old or 2338 malicious userspace programs can be identified. 2339 2340endchoice 2341 2342config CMDLINE_BOOL 2343 bool "Built-in kernel command line" 2344 ---help--- 2345 Allow for specifying boot arguments to the kernel at 2346 build time. On some systems (e.g. embedded ones), it is 2347 necessary or convenient to provide some or all of the 2348 kernel boot arguments with the kernel itself (that is, 2349 to not rely on the boot loader to provide them.) 2350 2351 To compile command line arguments into the kernel, 2352 set this option to 'Y', then fill in the 2353 boot arguments in CONFIG_CMDLINE. 2354 2355 Systems with fully functional boot loaders (i.e. non-embedded) 2356 should leave this option set to 'N'. 2357 2358config CMDLINE 2359 string "Built-in kernel command string" 2360 depends on CMDLINE_BOOL 2361 default "" 2362 ---help--- 2363 Enter arguments here that should be compiled into the kernel 2364 image and used at boot time. If the boot loader provides a 2365 command line at boot time, it is appended to this string to 2366 form the full kernel command line, when the system boots. 2367 2368 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2369 change this behavior. 2370 2371 In most cases, the command line (whether built-in or provided 2372 by the boot loader) should specify the device for the root 2373 file system. 2374 2375config CMDLINE_OVERRIDE 2376 bool "Built-in command line overrides boot loader arguments" 2377 depends on CMDLINE_BOOL 2378 ---help--- 2379 Set this option to 'Y' to have the kernel ignore the boot loader 2380 command line, and use ONLY the built-in command line. 2381 2382 This is used to work around broken boot loaders. This should 2383 be set to 'N' under normal conditions. 2384 2385config MODIFY_LDT_SYSCALL 2386 bool "Enable the LDT (local descriptor table)" if EXPERT 2387 default y 2388 ---help--- 2389 Linux can allow user programs to install a per-process x86 2390 Local Descriptor Table (LDT) using the modify_ldt(2) system 2391 call. This is required to run 16-bit or segmented code such as 2392 DOSEMU or some Wine programs. It is also used by some very old 2393 threading libraries. 2394 2395 Enabling this feature adds a small amount of overhead to 2396 context switches and increases the low-level kernel attack 2397 surface. Disabling it removes the modify_ldt(2) system call. 2398 2399 Saying 'N' here may make sense for embedded or server kernels. 2400 2401source "kernel/livepatch/Kconfig" 2402 2403endmenu 2404 2405config ARCH_HAS_ADD_PAGES 2406 def_bool y 2407 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2408 2409config ARCH_ENABLE_MEMORY_HOTPLUG 2410 def_bool y 2411 depends on X86_64 || (X86_32 && HIGHMEM) 2412 2413config ARCH_ENABLE_MEMORY_HOTREMOVE 2414 def_bool y 2415 depends on MEMORY_HOTPLUG 2416 2417config USE_PERCPU_NUMA_NODE_ID 2418 def_bool y 2419 depends on NUMA 2420 2421config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2422 def_bool y 2423 depends on X86_64 || X86_PAE 2424 2425config ARCH_ENABLE_HUGEPAGE_MIGRATION 2426 def_bool y 2427 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2428 2429config ARCH_ENABLE_THP_MIGRATION 2430 def_bool y 2431 depends on X86_64 && TRANSPARENT_HUGEPAGE 2432 2433menu "Power management and ACPI options" 2434 2435config ARCH_HIBERNATION_HEADER 2436 def_bool y 2437 depends on HIBERNATION 2438 2439source "kernel/power/Kconfig" 2440 2441source "drivers/acpi/Kconfig" 2442 2443source "drivers/sfi/Kconfig" 2444 2445config X86_APM_BOOT 2446 def_bool y 2447 depends on APM 2448 2449menuconfig APM 2450 tristate "APM (Advanced Power Management) BIOS support" 2451 depends on X86_32 && PM_SLEEP 2452 ---help--- 2453 APM is a BIOS specification for saving power using several different 2454 techniques. This is mostly useful for battery powered laptops with 2455 APM compliant BIOSes. If you say Y here, the system time will be 2456 reset after a RESUME operation, the /proc/apm device will provide 2457 battery status information, and user-space programs will receive 2458 notification of APM "events" (e.g. battery status change). 2459 2460 If you select "Y" here, you can disable actual use of the APM 2461 BIOS by passing the "apm=off" option to the kernel at boot time. 2462 2463 Note that the APM support is almost completely disabled for 2464 machines with more than one CPU. 2465 2466 In order to use APM, you will need supporting software. For location 2467 and more information, read <file:Documentation/power/apm-acpi.txt> 2468 and the Battery Powered Linux mini-HOWTO, available from 2469 <http://www.tldp.org/docs.html#howto>. 2470 2471 This driver does not spin down disk drives (see the hdparm(8) 2472 manpage ("man 8 hdparm") for that), and it doesn't turn off 2473 VESA-compliant "green" monitors. 2474 2475 This driver does not support the TI 4000M TravelMate and the ACER 2476 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2477 desktop machines also don't have compliant BIOSes, and this driver 2478 may cause those machines to panic during the boot phase. 2479 2480 Generally, if you don't have a battery in your machine, there isn't 2481 much point in using this driver and you should say N. If you get 2482 random kernel OOPSes or reboots that don't seem to be related to 2483 anything, try disabling/enabling this option (or disabling/enabling 2484 APM in your BIOS). 2485 2486 Some other things you should try when experiencing seemingly random, 2487 "weird" problems: 2488 2489 1) make sure that you have enough swap space and that it is 2490 enabled. 2491 2) pass the "no-hlt" option to the kernel 2492 3) switch on floating point emulation in the kernel and pass 2493 the "no387" option to the kernel 2494 4) pass the "floppy=nodma" option to the kernel 2495 5) pass the "mem=4M" option to the kernel (thereby disabling 2496 all but the first 4 MB of RAM) 2497 6) make sure that the CPU is not over clocked. 2498 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2499 8) disable the cache from your BIOS settings 2500 9) install a fan for the video card or exchange video RAM 2501 10) install a better fan for the CPU 2502 11) exchange RAM chips 2503 12) exchange the motherboard. 2504 2505 To compile this driver as a module, choose M here: the 2506 module will be called apm. 2507 2508if APM 2509 2510config APM_IGNORE_USER_SUSPEND 2511 bool "Ignore USER SUSPEND" 2512 ---help--- 2513 This option will ignore USER SUSPEND requests. On machines with a 2514 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2515 series notebooks, it is necessary to say Y because of a BIOS bug. 2516 2517config APM_DO_ENABLE 2518 bool "Enable PM at boot time" 2519 ---help--- 2520 Enable APM features at boot time. From page 36 of the APM BIOS 2521 specification: "When disabled, the APM BIOS does not automatically 2522 power manage devices, enter the Standby State, enter the Suspend 2523 State, or take power saving steps in response to CPU Idle calls." 2524 This driver will make CPU Idle calls when Linux is idle (unless this 2525 feature is turned off -- see "Do CPU IDLE calls", below). This 2526 should always save battery power, but more complicated APM features 2527 will be dependent on your BIOS implementation. You may need to turn 2528 this option off if your computer hangs at boot time when using APM 2529 support, or if it beeps continuously instead of suspending. Turn 2530 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2531 T400CDT. This is off by default since most machines do fine without 2532 this feature. 2533 2534config APM_CPU_IDLE 2535 depends on CPU_IDLE 2536 bool "Make CPU Idle calls when idle" 2537 ---help--- 2538 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2539 On some machines, this can activate improved power savings, such as 2540 a slowed CPU clock rate, when the machine is idle. These idle calls 2541 are made after the idle loop has run for some length of time (e.g., 2542 333 mS). On some machines, this will cause a hang at boot time or 2543 whenever the CPU becomes idle. (On machines with more than one CPU, 2544 this option does nothing.) 2545 2546config APM_DISPLAY_BLANK 2547 bool "Enable console blanking using APM" 2548 ---help--- 2549 Enable console blanking using the APM. Some laptops can use this to 2550 turn off the LCD backlight when the screen blanker of the Linux 2551 virtual console blanks the screen. Note that this is only used by 2552 the virtual console screen blanker, and won't turn off the backlight 2553 when using the X Window system. This also doesn't have anything to 2554 do with your VESA-compliant power-saving monitor. Further, this 2555 option doesn't work for all laptops -- it might not turn off your 2556 backlight at all, or it might print a lot of errors to the console, 2557 especially if you are using gpm. 2558 2559config APM_ALLOW_INTS 2560 bool "Allow interrupts during APM BIOS calls" 2561 ---help--- 2562 Normally we disable external interrupts while we are making calls to 2563 the APM BIOS as a measure to lessen the effects of a badly behaving 2564 BIOS implementation. The BIOS should reenable interrupts if it 2565 needs to. Unfortunately, some BIOSes do not -- especially those in 2566 many of the newer IBM Thinkpads. If you experience hangs when you 2567 suspend, try setting this to Y. Otherwise, say N. 2568 2569endif # APM 2570 2571source "drivers/cpufreq/Kconfig" 2572 2573source "drivers/cpuidle/Kconfig" 2574 2575source "drivers/idle/Kconfig" 2576 2577endmenu 2578 2579 2580menu "Bus options (PCI etc.)" 2581 2582choice 2583 prompt "PCI access mode" 2584 depends on X86_32 && PCI 2585 default PCI_GOANY 2586 ---help--- 2587 On PCI systems, the BIOS can be used to detect the PCI devices and 2588 determine their configuration. However, some old PCI motherboards 2589 have BIOS bugs and may crash if this is done. Also, some embedded 2590 PCI-based systems don't have any BIOS at all. Linux can also try to 2591 detect the PCI hardware directly without using the BIOS. 2592 2593 With this option, you can specify how Linux should detect the 2594 PCI devices. If you choose "BIOS", the BIOS will be used, 2595 if you choose "Direct", the BIOS won't be used, and if you 2596 choose "MMConfig", then PCI Express MMCONFIG will be used. 2597 If you choose "Any", the kernel will try MMCONFIG, then the 2598 direct access method and falls back to the BIOS if that doesn't 2599 work. If unsure, go with the default, which is "Any". 2600 2601config PCI_GOBIOS 2602 bool "BIOS" 2603 2604config PCI_GOMMCONFIG 2605 bool "MMConfig" 2606 2607config PCI_GODIRECT 2608 bool "Direct" 2609 2610config PCI_GOOLPC 2611 bool "OLPC XO-1" 2612 depends on OLPC 2613 2614config PCI_GOANY 2615 bool "Any" 2616 2617endchoice 2618 2619config PCI_BIOS 2620 def_bool y 2621 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2622 2623# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2624config PCI_DIRECT 2625 def_bool y 2626 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2627 2628config PCI_MMCONFIG 2629 bool "Support mmconfig PCI config space access" if X86_64 2630 default y 2631 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2632 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2633 2634config PCI_OLPC 2635 def_bool y 2636 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2637 2638config PCI_XEN 2639 def_bool y 2640 depends on PCI && XEN 2641 select SWIOTLB_XEN 2642 2643config MMCONF_FAM10H 2644 def_bool y 2645 depends on X86_64 && PCI_MMCONFIG && ACPI 2646 2647config PCI_CNB20LE_QUIRK 2648 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2649 depends on PCI 2650 help 2651 Read the PCI windows out of the CNB20LE host bridge. This allows 2652 PCI hotplug to work on systems with the CNB20LE chipset which do 2653 not have ACPI. 2654 2655 There's no public spec for this chipset, and this functionality 2656 is known to be incomplete. 2657 2658 You should say N unless you know you need this. 2659 2660config ISA_BUS 2661 bool "ISA bus support on modern systems" if EXPERT 2662 help 2663 Expose ISA bus device drivers and options available for selection and 2664 configuration. Enable this option if your target machine has an ISA 2665 bus. ISA is an older system, displaced by PCI and newer bus 2666 architectures -- if your target machine is modern, it probably does 2667 not have an ISA bus. 2668 2669 If unsure, say N. 2670 2671# x86_64 have no ISA slots, but can have ISA-style DMA. 2672config ISA_DMA_API 2673 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2674 default y 2675 help 2676 Enables ISA-style DMA support for devices requiring such controllers. 2677 If unsure, say Y. 2678 2679if X86_32 2680 2681config ISA 2682 bool "ISA support" 2683 ---help--- 2684 Find out whether you have ISA slots on your motherboard. ISA is the 2685 name of a bus system, i.e. the way the CPU talks to the other stuff 2686 inside your box. Other bus systems are PCI, EISA, MicroChannel 2687 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2688 newer boards don't support it. If you have ISA, say Y, otherwise N. 2689 2690config SCx200 2691 tristate "NatSemi SCx200 support" 2692 ---help--- 2693 This provides basic support for National Semiconductor's 2694 (now AMD's) Geode processors. The driver probes for the 2695 PCI-IDs of several on-chip devices, so its a good dependency 2696 for other scx200_* drivers. 2697 2698 If compiled as a module, the driver is named scx200. 2699 2700config SCx200HR_TIMER 2701 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2702 depends on SCx200 2703 default y 2704 ---help--- 2705 This driver provides a clocksource built upon the on-chip 2706 27MHz high-resolution timer. Its also a workaround for 2707 NSC Geode SC-1100's buggy TSC, which loses time when the 2708 processor goes idle (as is done by the scheduler). The 2709 other workaround is idle=poll boot option. 2710 2711config OLPC 2712 bool "One Laptop Per Child support" 2713 depends on !X86_PAE 2714 select GPIOLIB 2715 select OF 2716 select OF_PROMTREE 2717 select IRQ_DOMAIN 2718 ---help--- 2719 Add support for detecting the unique features of the OLPC 2720 XO hardware. 2721 2722config OLPC_XO1_PM 2723 bool "OLPC XO-1 Power Management" 2724 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2725 ---help--- 2726 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2727 2728config OLPC_XO1_RTC 2729 bool "OLPC XO-1 Real Time Clock" 2730 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2731 ---help--- 2732 Add support for the XO-1 real time clock, which can be used as a 2733 programmable wakeup source. 2734 2735config OLPC_XO1_SCI 2736 bool "OLPC XO-1 SCI extras" 2737 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2738 depends on INPUT=y 2739 select POWER_SUPPLY 2740 ---help--- 2741 Add support for SCI-based features of the OLPC XO-1 laptop: 2742 - EC-driven system wakeups 2743 - Power button 2744 - Ebook switch 2745 - Lid switch 2746 - AC adapter status updates 2747 - Battery status updates 2748 2749config OLPC_XO15_SCI 2750 bool "OLPC XO-1.5 SCI extras" 2751 depends on OLPC && ACPI 2752 select POWER_SUPPLY 2753 ---help--- 2754 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2755 - EC-driven system wakeups 2756 - AC adapter status updates 2757 - Battery status updates 2758 2759config ALIX 2760 bool "PCEngines ALIX System Support (LED setup)" 2761 select GPIOLIB 2762 ---help--- 2763 This option enables system support for the PCEngines ALIX. 2764 At present this just sets up LEDs for GPIO control on 2765 ALIX2/3/6 boards. However, other system specific setup should 2766 get added here. 2767 2768 Note: You must still enable the drivers for GPIO and LED support 2769 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2770 2771 Note: You have to set alix.force=1 for boards with Award BIOS. 2772 2773config NET5501 2774 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2775 select GPIOLIB 2776 ---help--- 2777 This option enables system support for the Soekris Engineering net5501. 2778 2779config GEOS 2780 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2781 select GPIOLIB 2782 depends on DMI 2783 ---help--- 2784 This option enables system support for the Traverse Technologies GEOS. 2785 2786config TS5500 2787 bool "Technologic Systems TS-5500 platform support" 2788 depends on MELAN 2789 select CHECK_SIGNATURE 2790 select NEW_LEDS 2791 select LEDS_CLASS 2792 ---help--- 2793 This option enables system support for the Technologic Systems TS-5500. 2794 2795endif # X86_32 2796 2797config AMD_NB 2798 def_bool y 2799 depends on CPU_SUP_AMD && PCI 2800 2801config X86_SYSFB 2802 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2803 help 2804 Firmwares often provide initial graphics framebuffers so the BIOS, 2805 bootloader or kernel can show basic video-output during boot for 2806 user-guidance and debugging. Historically, x86 used the VESA BIOS 2807 Extensions and EFI-framebuffers for this, which are mostly limited 2808 to x86. 2809 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2810 framebuffers so the new generic system-framebuffer drivers can be 2811 used on x86. If the framebuffer is not compatible with the generic 2812 modes, it is advertised as fallback platform framebuffer so legacy 2813 drivers like efifb, vesafb and uvesafb can pick it up. 2814 If this option is not selected, all system framebuffers are always 2815 marked as fallback platform framebuffers as usual. 2816 2817 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2818 not be able to pick up generic system framebuffers if this option 2819 is selected. You are highly encouraged to enable simplefb as 2820 replacement if you select this option. simplefb can correctly deal 2821 with generic system framebuffers. But you should still keep vesafb 2822 and others enabled as fallback if a system framebuffer is 2823 incompatible with simplefb. 2824 2825 If unsure, say Y. 2826 2827endmenu 2828 2829 2830menu "Binary Emulations" 2831 2832config IA32_EMULATION 2833 bool "IA32 Emulation" 2834 depends on X86_64 2835 select ARCH_WANT_OLD_COMPAT_IPC 2836 select BINFMT_ELF 2837 select COMPAT_BINFMT_ELF 2838 select COMPAT_OLD_SIGACTION 2839 ---help--- 2840 Include code to run legacy 32-bit programs under a 2841 64-bit kernel. You should likely turn this on, unless you're 2842 100% sure that you don't have any 32-bit programs left. 2843 2844config IA32_AOUT 2845 tristate "IA32 a.out support" 2846 depends on IA32_EMULATION 2847 ---help--- 2848 Support old a.out binaries in the 32bit emulation. 2849 2850config X86_X32 2851 bool "x32 ABI for 64-bit mode" 2852 depends on X86_64 2853 ---help--- 2854 Include code to run binaries for the x32 native 32-bit ABI 2855 for 64-bit processors. An x32 process gets access to the 2856 full 64-bit register file and wide data path while leaving 2857 pointers at 32 bits for smaller memory footprint. 2858 2859 You will need a recent binutils (2.22 or later) with 2860 elf32_x86_64 support enabled to compile a kernel with this 2861 option set. 2862 2863config COMPAT_32 2864 def_bool y 2865 depends on IA32_EMULATION || X86_32 2866 select HAVE_UID16 2867 select OLD_SIGSUSPEND3 2868 2869config COMPAT 2870 def_bool y 2871 depends on IA32_EMULATION || X86_X32 2872 2873if COMPAT 2874config COMPAT_FOR_U64_ALIGNMENT 2875 def_bool y 2876 2877config SYSVIPC_COMPAT 2878 def_bool y 2879 depends on SYSVIPC 2880endif 2881 2882endmenu 2883 2884 2885config HAVE_ATOMIC_IOMAP 2886 def_bool y 2887 depends on X86_32 2888 2889config X86_DEV_DMA_OPS 2890 bool 2891 depends on X86_64 || STA2X11 2892 2893config X86_DMA_REMAP 2894 bool 2895 depends on STA2X11 2896 2897config HAVE_GENERIC_GUP 2898 def_bool y 2899 2900source "drivers/firmware/Kconfig" 2901 2902source "arch/x86/kvm/Kconfig" 2903