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_DEBUG_STACKOVERFLOW 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 21config X86_64 22 def_bool y 23 depends on 64BIT 24 # Options that are inherently 64-bit kernel only: 25 select ARCH_HAS_GIGANTIC_PAGE 26 select ARCH_SUPPORTS_INT128 27 select ARCH_USE_CMPXCHG_LOCKREF 28 select HAVE_ARCH_SOFT_DIRTY 29 select MODULES_USE_ELF_RELA 30 select NEED_DMA_MAP_STATE 31 select SWIOTLB 32 select ARCH_HAS_SYSCALL_WRAPPER 33 34config FORCE_DYNAMIC_FTRACE 35 def_bool y 36 depends on X86_32 37 depends on FUNCTION_TRACER 38 select DYNAMIC_FTRACE 39 help 40 We keep the static function tracing (!DYNAMIC_FTRACE) around 41 in order to test the non static function tracing in the 42 generic code, as other architectures still use it. But we 43 only need to keep it around for x86_64. No need to keep it 44 for x86_32. For x86_32, force DYNAMIC_FTRACE. 45# 46# Arch settings 47# 48# ( Note that options that are marked 'if X86_64' could in principle be 49# ported to 32-bit as well. ) 50# 51config X86 52 def_bool y 53 # 54 # Note: keep this list sorted alphabetically 55 # 56 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 57 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 58 select ARCH_32BIT_OFF_T if X86_32 59 select ARCH_CLOCKSOURCE_DATA 60 select ARCH_CLOCKSOURCE_INIT 61 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 62 select ARCH_HAS_DEBUG_VIRTUAL 63 select ARCH_HAS_DEVMEM_IS_ALLOWED 64 select ARCH_HAS_ELF_RANDOMIZE 65 select ARCH_HAS_FAST_MULTIPLIER 66 select ARCH_HAS_FILTER_PGPROT 67 select ARCH_HAS_FORTIFY_SOURCE 68 select ARCH_HAS_GCOV_PROFILE_ALL 69 select ARCH_HAS_KCOV if X86_64 70 select ARCH_HAS_MEMBARRIER_SYNC_CORE 71 select ARCH_HAS_PMEM_API if X86_64 72 select ARCH_HAS_PTE_SPECIAL 73 select ARCH_HAS_REFCOUNT 74 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 75 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 76 select ARCH_HAS_SET_MEMORY 77 select ARCH_HAS_SET_DIRECT_MAP 78 select ARCH_HAS_STRICT_KERNEL_RWX 79 select ARCH_HAS_STRICT_MODULE_RWX 80 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 81 select ARCH_HAS_UBSAN_SANITIZE_ALL 82 select ARCH_HAS_ZONE_DEVICE if X86_64 83 select ARCH_HAVE_NMI_SAFE_CMPXCHG 84 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 85 select ARCH_MIGHT_HAVE_PC_PARPORT 86 select ARCH_MIGHT_HAVE_PC_SERIO 87 select ARCH_STACKWALK 88 select ARCH_SUPPORTS_ACPI 89 select ARCH_SUPPORTS_ATOMIC_RMW 90 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 91 select ARCH_USE_BUILTIN_BSWAP 92 select ARCH_USE_QUEUED_RWLOCKS 93 select ARCH_USE_QUEUED_SPINLOCKS 94 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 95 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 96 select ARCH_WANTS_THP_SWAP if X86_64 97 select BUILDTIME_EXTABLE_SORT 98 select CLKEVT_I8253 99 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 100 select CLOCKSOURCE_WATCHDOG 101 select DCACHE_WORD_ACCESS 102 select EDAC_ATOMIC_SCRUB 103 select EDAC_SUPPORT 104 select GENERIC_CLOCKEVENTS 105 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 106 select GENERIC_CLOCKEVENTS_MIN_ADJUST 107 select GENERIC_CMOS_UPDATE 108 select GENERIC_CPU_AUTOPROBE 109 select GENERIC_CPU_VULNERABILITIES 110 select GENERIC_EARLY_IOREMAP 111 select GENERIC_FIND_FIRST_BIT 112 select GENERIC_IOMAP 113 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 114 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 115 select GENERIC_IRQ_MIGRATION if SMP 116 select GENERIC_IRQ_PROBE 117 select GENERIC_IRQ_RESERVATION_MODE 118 select GENERIC_IRQ_SHOW 119 select GENERIC_PENDING_IRQ if SMP 120 select GENERIC_SMP_IDLE_THREAD 121 select GENERIC_STRNCPY_FROM_USER 122 select GENERIC_STRNLEN_USER 123 select GENERIC_TIME_VSYSCALL 124 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 125 select HAVE_ACPI_APEI if ACPI 126 select HAVE_ACPI_APEI_NMI if ACPI 127 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 128 select HAVE_ARCH_AUDITSYSCALL 129 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 130 select HAVE_ARCH_JUMP_LABEL 131 select HAVE_ARCH_JUMP_LABEL_RELATIVE 132 select HAVE_ARCH_KASAN if X86_64 133 select HAVE_ARCH_KGDB 134 select HAVE_ARCH_MMAP_RND_BITS if MMU 135 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 136 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 137 select HAVE_ARCH_PREL32_RELOCATIONS 138 select HAVE_ARCH_SECCOMP_FILTER 139 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 140 select HAVE_ARCH_STACKLEAK 141 select HAVE_ARCH_TRACEHOOK 142 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 143 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 144 select HAVE_ARCH_VMAP_STACK if X86_64 145 select HAVE_ARCH_WITHIN_STACK_FRAMES 146 select HAVE_CMPXCHG_DOUBLE 147 select HAVE_CMPXCHG_LOCAL 148 select HAVE_CONTEXT_TRACKING if X86_64 149 select HAVE_COPY_THREAD_TLS 150 select HAVE_C_RECORDMCOUNT 151 select HAVE_DEBUG_KMEMLEAK 152 select HAVE_DMA_CONTIGUOUS 153 select HAVE_DYNAMIC_FTRACE 154 select HAVE_DYNAMIC_FTRACE_WITH_REGS 155 select HAVE_EBPF_JIT 156 select HAVE_EFFICIENT_UNALIGNED_ACCESS 157 select HAVE_EISA 158 select HAVE_EXIT_THREAD 159 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 160 select HAVE_FTRACE_MCOUNT_RECORD 161 select HAVE_FUNCTION_GRAPH_TRACER 162 select HAVE_FUNCTION_TRACER 163 select HAVE_GCC_PLUGINS 164 select HAVE_HW_BREAKPOINT 165 select HAVE_IDE 166 select HAVE_IOREMAP_PROT 167 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 168 select HAVE_IRQ_TIME_ACCOUNTING 169 select HAVE_KERNEL_BZIP2 170 select HAVE_KERNEL_GZIP 171 select HAVE_KERNEL_LZ4 172 select HAVE_KERNEL_LZMA 173 select HAVE_KERNEL_LZO 174 select HAVE_KERNEL_XZ 175 select HAVE_KPROBES 176 select HAVE_KPROBES_ON_FTRACE 177 select HAVE_FUNCTION_ERROR_INJECTION 178 select HAVE_KRETPROBES 179 select HAVE_KVM 180 select HAVE_LIVEPATCH if X86_64 181 select HAVE_MEMBLOCK_NODE_MAP 182 select HAVE_MIXED_BREAKPOINTS_REGS 183 select HAVE_MOD_ARCH_SPECIFIC 184 select HAVE_MOVE_PMD 185 select HAVE_NMI 186 select HAVE_OPROFILE 187 select HAVE_OPTPROBES 188 select HAVE_PCSPKR_PLATFORM 189 select HAVE_PERF_EVENTS 190 select HAVE_PERF_EVENTS_NMI 191 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 192 select HAVE_PCI 193 select HAVE_PERF_REGS 194 select HAVE_PERF_USER_STACK_DUMP 195 select HAVE_RCU_TABLE_FREE if PARAVIRT 196 select HAVE_REGS_AND_STACK_ACCESS_API 197 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 198 select HAVE_FUNCTION_ARG_ACCESS_API 199 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 200 select HAVE_STACK_VALIDATION if X86_64 201 select HAVE_RSEQ 202 select HAVE_SYSCALL_TRACEPOINTS 203 select HAVE_UNSTABLE_SCHED_CLOCK 204 select HAVE_USER_RETURN_NOTIFIER 205 select HOTPLUG_SMT if SMP 206 select IRQ_FORCED_THREADING 207 select NEED_SG_DMA_LENGTH 208 select PCI_DOMAINS if PCI 209 select PCI_LOCKLESS_CONFIG if PCI 210 select PERF_EVENTS 211 select RTC_LIB 212 select RTC_MC146818_LIB 213 select SPARSE_IRQ 214 select SRCU 215 select SYSCTL_EXCEPTION_TRACE 216 select THREAD_INFO_IN_TASK 217 select USER_STACKTRACE_SUPPORT 218 select VIRT_TO_BUS 219 select X86_FEATURE_NAMES if PROC_FS 220 221config INSTRUCTION_DECODER 222 def_bool y 223 depends on KPROBES || PERF_EVENTS || UPROBES 224 225config OUTPUT_FORMAT 226 string 227 default "elf32-i386" if X86_32 228 default "elf64-x86-64" if X86_64 229 230config ARCH_DEFCONFIG 231 string 232 default "arch/x86/configs/i386_defconfig" if X86_32 233 default "arch/x86/configs/x86_64_defconfig" if X86_64 234 235config LOCKDEP_SUPPORT 236 def_bool y 237 238config STACKTRACE_SUPPORT 239 def_bool y 240 241config MMU 242 def_bool y 243 244config ARCH_MMAP_RND_BITS_MIN 245 default 28 if 64BIT 246 default 8 247 248config ARCH_MMAP_RND_BITS_MAX 249 default 32 if 64BIT 250 default 16 251 252config ARCH_MMAP_RND_COMPAT_BITS_MIN 253 default 8 254 255config ARCH_MMAP_RND_COMPAT_BITS_MAX 256 default 16 257 258config SBUS 259 bool 260 261config GENERIC_ISA_DMA 262 def_bool y 263 depends on ISA_DMA_API 264 265config GENERIC_BUG 266 def_bool y 267 depends on BUG 268 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 269 270config GENERIC_BUG_RELATIVE_POINTERS 271 bool 272 273config ARCH_MAY_HAVE_PC_FDC 274 def_bool y 275 depends on ISA_DMA_API 276 277config GENERIC_CALIBRATE_DELAY 278 def_bool y 279 280config ARCH_HAS_CPU_RELAX 281 def_bool y 282 283config ARCH_HAS_CACHE_LINE_SIZE 284 def_bool y 285 286config ARCH_HAS_FILTER_PGPROT 287 def_bool y 288 289config HAVE_SETUP_PER_CPU_AREA 290 def_bool y 291 292config NEED_PER_CPU_EMBED_FIRST_CHUNK 293 def_bool y 294 295config NEED_PER_CPU_PAGE_FIRST_CHUNK 296 def_bool y 297 298config ARCH_HIBERNATION_POSSIBLE 299 def_bool y 300 301config ARCH_SUSPEND_POSSIBLE 302 def_bool y 303 304config ARCH_WANT_HUGE_PMD_SHARE 305 def_bool y 306 307config ARCH_WANT_GENERAL_HUGETLB 308 def_bool y 309 310config ZONE_DMA32 311 def_bool y if X86_64 312 313config AUDIT_ARCH 314 def_bool y if X86_64 315 316config ARCH_SUPPORTS_DEBUG_PAGEALLOC 317 def_bool y 318 319config KASAN_SHADOW_OFFSET 320 hex 321 depends on KASAN 322 default 0xdffffc0000000000 323 324config HAVE_INTEL_TXT 325 def_bool y 326 depends on INTEL_IOMMU && ACPI 327 328config X86_32_SMP 329 def_bool y 330 depends on X86_32 && SMP 331 332config X86_64_SMP 333 def_bool y 334 depends on X86_64 && SMP 335 336config X86_32_LAZY_GS 337 def_bool y 338 depends on X86_32 && !STACKPROTECTOR 339 340config ARCH_SUPPORTS_UPROBES 341 def_bool y 342 343config FIX_EARLYCON_MEM 344 def_bool y 345 346config DYNAMIC_PHYSICAL_MASK 347 bool 348 349config PGTABLE_LEVELS 350 int 351 default 5 if X86_5LEVEL 352 default 4 if X86_64 353 default 3 if X86_PAE 354 default 2 355 356config CC_HAS_SANE_STACKPROTECTOR 357 bool 358 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 359 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 360 help 361 We have to make sure stack protector is unconditionally disabled if 362 the compiler produces broken code. 363 364menu "Processor type and features" 365 366config ZONE_DMA 367 bool "DMA memory allocation support" if EXPERT 368 default y 369 help 370 DMA memory allocation support allows devices with less than 32-bit 371 addressing to allocate within the first 16MB of address space. 372 Disable if no such devices will be used. 373 374 If unsure, say Y. 375 376config SMP 377 bool "Symmetric multi-processing support" 378 ---help--- 379 This enables support for systems with more than one CPU. If you have 380 a system with only one CPU, say N. If you have a system with more 381 than one CPU, say Y. 382 383 If you say N here, the kernel will run on uni- and multiprocessor 384 machines, but will use only one CPU of a multiprocessor machine. If 385 you say Y here, the kernel will run on many, but not all, 386 uniprocessor machines. On a uniprocessor machine, the kernel 387 will run faster if you say N here. 388 389 Note that if you say Y here and choose architecture "586" or 390 "Pentium" under "Processor family", the kernel will not work on 486 391 architectures. Similarly, multiprocessor kernels for the "PPro" 392 architecture may not work on all Pentium based boards. 393 394 People using multiprocessor machines who say Y here should also say 395 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 396 Management" code will be disabled if you say Y here. 397 398 See also <file:Documentation/x86/i386/IO-APIC.txt>, 399 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 400 <http://www.tldp.org/docs.html#howto>. 401 402 If you don't know what to do here, say N. 403 404config X86_FEATURE_NAMES 405 bool "Processor feature human-readable names" if EMBEDDED 406 default y 407 ---help--- 408 This option compiles in a table of x86 feature bits and corresponding 409 names. This is required to support /proc/cpuinfo and a few kernel 410 messages. You can disable this to save space, at the expense of 411 making those few kernel messages show numeric feature bits instead. 412 413 If in doubt, say Y. 414 415config X86_X2APIC 416 bool "Support x2apic" 417 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 418 ---help--- 419 This enables x2apic support on CPUs that have this feature. 420 421 This allows 32-bit apic IDs (so it can support very large systems), 422 and accesses the local apic via MSRs not via mmio. 423 424 If you don't know what to do here, say N. 425 426config X86_MPPARSE 427 bool "Enable MPS table" if ACPI || SFI 428 default y 429 depends on X86_LOCAL_APIC 430 ---help--- 431 For old smp systems that do not have proper acpi support. Newer systems 432 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 433 434config GOLDFISH 435 def_bool y 436 depends on X86_GOLDFISH 437 438config RETPOLINE 439 bool "Avoid speculative indirect branches in kernel" 440 default y 441 select STACK_VALIDATION if HAVE_STACK_VALIDATION 442 help 443 Compile kernel with the retpoline compiler options to guard against 444 kernel-to-user data leaks by avoiding speculative indirect 445 branches. Requires a compiler with -mindirect-branch=thunk-extern 446 support for full protection. The kernel may run slower. 447 448config X86_CPU_RESCTRL 449 bool "x86 CPU resource control support" 450 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 451 select KERNFS 452 help 453 Enable x86 CPU resource control support. 454 455 Provide support for the allocation and monitoring of system resources 456 usage by the CPU. 457 458 Intel calls this Intel Resource Director Technology 459 (Intel(R) RDT). More information about RDT can be found in the 460 Intel x86 Architecture Software Developer Manual. 461 462 AMD calls this AMD Platform Quality of Service (AMD QoS). 463 More information about AMD QoS can be found in the AMD64 Technology 464 Platform Quality of Service Extensions manual. 465 466 Say N if unsure. 467 468if X86_32 469config X86_BIGSMP 470 bool "Support for big SMP systems with more than 8 CPUs" 471 depends on SMP 472 ---help--- 473 This option is needed for the systems that have more than 8 CPUs 474 475config X86_EXTENDED_PLATFORM 476 bool "Support for extended (non-PC) x86 platforms" 477 default y 478 ---help--- 479 If you disable this option then the kernel will only support 480 standard PC platforms. (which covers the vast majority of 481 systems out there.) 482 483 If you enable this option then you'll be able to select support 484 for the following (non-PC) 32 bit x86 platforms: 485 Goldfish (Android emulator) 486 AMD Elan 487 RDC R-321x SoC 488 SGI 320/540 (Visual Workstation) 489 STA2X11-based (e.g. Northville) 490 Moorestown MID devices 491 492 If you have one of these systems, or if you want to build a 493 generic distribution kernel, say Y here - otherwise say N. 494endif 495 496if X86_64 497config X86_EXTENDED_PLATFORM 498 bool "Support for extended (non-PC) x86 platforms" 499 default y 500 ---help--- 501 If you disable this option then the kernel will only support 502 standard PC platforms. (which covers the vast majority of 503 systems out there.) 504 505 If you enable this option then you'll be able to select support 506 for the following (non-PC) 64 bit x86 platforms: 507 Numascale NumaChip 508 ScaleMP vSMP 509 SGI Ultraviolet 510 511 If you have one of these systems, or if you want to build a 512 generic distribution kernel, say Y here - otherwise say N. 513endif 514# This is an alphabetically sorted list of 64 bit extended platforms 515# Please maintain the alphabetic order if and when there are additions 516config X86_NUMACHIP 517 bool "Numascale NumaChip" 518 depends on X86_64 519 depends on X86_EXTENDED_PLATFORM 520 depends on NUMA 521 depends on SMP 522 depends on X86_X2APIC 523 depends on PCI_MMCONFIG 524 ---help--- 525 Adds support for Numascale NumaChip large-SMP systems. Needed to 526 enable more than ~168 cores. 527 If you don't have one of these, you should say N here. 528 529config X86_VSMP 530 bool "ScaleMP vSMP" 531 select HYPERVISOR_GUEST 532 select PARAVIRT 533 depends on X86_64 && PCI 534 depends on X86_EXTENDED_PLATFORM 535 depends on SMP 536 ---help--- 537 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 538 supposed to run on these EM64T-based machines. Only choose this option 539 if you have one of these machines. 540 541config X86_UV 542 bool "SGI Ultraviolet" 543 depends on X86_64 544 depends on X86_EXTENDED_PLATFORM 545 depends on NUMA 546 depends on EFI 547 depends on X86_X2APIC 548 depends on PCI 549 ---help--- 550 This option is needed in order to support SGI Ultraviolet systems. 551 If you don't have one of these, you should say N here. 552 553# Following is an alphabetically sorted list of 32 bit extended platforms 554# Please maintain the alphabetic order if and when there are additions 555 556config X86_GOLDFISH 557 bool "Goldfish (Virtual Platform)" 558 depends on X86_EXTENDED_PLATFORM 559 ---help--- 560 Enable support for the Goldfish virtual platform used primarily 561 for Android development. Unless you are building for the Android 562 Goldfish emulator say N here. 563 564config X86_INTEL_CE 565 bool "CE4100 TV platform" 566 depends on PCI 567 depends on PCI_GODIRECT 568 depends on X86_IO_APIC 569 depends on X86_32 570 depends on X86_EXTENDED_PLATFORM 571 select X86_REBOOTFIXUPS 572 select OF 573 select OF_EARLY_FLATTREE 574 ---help--- 575 Select for the Intel CE media processor (CE4100) SOC. 576 This option compiles in support for the CE4100 SOC for settop 577 boxes and media devices. 578 579config X86_INTEL_MID 580 bool "Intel MID platform support" 581 depends on X86_EXTENDED_PLATFORM 582 depends on X86_PLATFORM_DEVICES 583 depends on PCI 584 depends on X86_64 || (PCI_GOANY && X86_32) 585 depends on X86_IO_APIC 586 select SFI 587 select I2C 588 select DW_APB_TIMER 589 select APB_TIMER 590 select INTEL_SCU_IPC 591 select MFD_INTEL_MSIC 592 ---help--- 593 Select to build a kernel capable of supporting Intel MID (Mobile 594 Internet Device) platform systems which do not have the PCI legacy 595 interfaces. If you are building for a PC class system say N here. 596 597 Intel MID platforms are based on an Intel processor and chipset which 598 consume less power than most of the x86 derivatives. 599 600config X86_INTEL_QUARK 601 bool "Intel Quark platform support" 602 depends on X86_32 603 depends on X86_EXTENDED_PLATFORM 604 depends on X86_PLATFORM_DEVICES 605 depends on X86_TSC 606 depends on PCI 607 depends on PCI_GOANY 608 depends on X86_IO_APIC 609 select IOSF_MBI 610 select INTEL_IMR 611 select COMMON_CLK 612 ---help--- 613 Select to include support for Quark X1000 SoC. 614 Say Y here if you have a Quark based system such as the Arduino 615 compatible Intel Galileo. 616 617config X86_INTEL_LPSS 618 bool "Intel Low Power Subsystem Support" 619 depends on X86 && ACPI && PCI 620 select COMMON_CLK 621 select PINCTRL 622 select IOSF_MBI 623 ---help--- 624 Select to build support for Intel Low Power Subsystem such as 625 found on Intel Lynxpoint PCH. Selecting this option enables 626 things like clock tree (common clock framework) and pincontrol 627 which are needed by the LPSS peripheral drivers. 628 629config X86_AMD_PLATFORM_DEVICE 630 bool "AMD ACPI2Platform devices support" 631 depends on ACPI 632 select COMMON_CLK 633 select PINCTRL 634 ---help--- 635 Select to interpret AMD specific ACPI device to platform device 636 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 637 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 638 implemented under PINCTRL subsystem. 639 640config IOSF_MBI 641 tristate "Intel SoC IOSF Sideband support for SoC platforms" 642 depends on PCI 643 ---help--- 644 This option enables sideband register access support for Intel SoC 645 platforms. On these platforms the IOSF sideband is used in lieu of 646 MSR's for some register accesses, mostly but not limited to thermal 647 and power. Drivers may query the availability of this device to 648 determine if they need the sideband in order to work on these 649 platforms. The sideband is available on the following SoC products. 650 This list is not meant to be exclusive. 651 - BayTrail 652 - Braswell 653 - Quark 654 655 You should say Y if you are running a kernel on one of these SoC's. 656 657config IOSF_MBI_DEBUG 658 bool "Enable IOSF sideband access through debugfs" 659 depends on IOSF_MBI && DEBUG_FS 660 ---help--- 661 Select this option to expose the IOSF sideband access registers (MCR, 662 MDR, MCRX) through debugfs to write and read register information from 663 different units on the SoC. This is most useful for obtaining device 664 state information for debug and analysis. As this is a general access 665 mechanism, users of this option would have specific knowledge of the 666 device they want to access. 667 668 If you don't require the option or are in doubt, say N. 669 670config X86_RDC321X 671 bool "RDC R-321x SoC" 672 depends on X86_32 673 depends on X86_EXTENDED_PLATFORM 674 select M486 675 select X86_REBOOTFIXUPS 676 ---help--- 677 This option is needed for RDC R-321x system-on-chip, also known 678 as R-8610-(G). 679 If you don't have one of these chips, you should say N here. 680 681config X86_32_NON_STANDARD 682 bool "Support non-standard 32-bit SMP architectures" 683 depends on X86_32 && SMP 684 depends on X86_EXTENDED_PLATFORM 685 ---help--- 686 This option compiles in the bigsmp and STA2X11 default 687 subarchitectures. It is intended for a generic binary 688 kernel. If you select them all, kernel will probe it one by 689 one and will fallback to default. 690 691# Alphabetically sorted list of Non standard 32 bit platforms 692 693config X86_SUPPORTS_MEMORY_FAILURE 694 def_bool y 695 # MCE code calls memory_failure(): 696 depends on X86_MCE 697 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 698 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 699 depends on X86_64 || !SPARSEMEM 700 select ARCH_SUPPORTS_MEMORY_FAILURE 701 702config STA2X11 703 bool "STA2X11 Companion Chip Support" 704 depends on X86_32_NON_STANDARD && PCI 705 select ARCH_HAS_PHYS_TO_DMA 706 select SWIOTLB 707 select MFD_STA2X11 708 select GPIOLIB 709 ---help--- 710 This adds support for boards based on the STA2X11 IO-Hub, 711 a.k.a. "ConneXt". The chip is used in place of the standard 712 PC chipset, so all "standard" peripherals are missing. If this 713 option is selected the kernel will still be able to boot on 714 standard PC machines. 715 716config X86_32_IRIS 717 tristate "Eurobraille/Iris poweroff module" 718 depends on X86_32 719 ---help--- 720 The Iris machines from EuroBraille do not have APM or ACPI support 721 to shut themselves down properly. A special I/O sequence is 722 needed to do so, which is what this module does at 723 kernel shutdown. 724 725 This is only for Iris machines from EuroBraille. 726 727 If unused, say N. 728 729config SCHED_OMIT_FRAME_POINTER 730 def_bool y 731 prompt "Single-depth WCHAN output" 732 depends on X86 733 ---help--- 734 Calculate simpler /proc/<PID>/wchan values. If this option 735 is disabled then wchan values will recurse back to the 736 caller function. This provides more accurate wchan values, 737 at the expense of slightly more scheduling overhead. 738 739 If in doubt, say "Y". 740 741menuconfig HYPERVISOR_GUEST 742 bool "Linux guest support" 743 ---help--- 744 Say Y here to enable options for running Linux under various hyper- 745 visors. This option enables basic hypervisor detection and platform 746 setup. 747 748 If you say N, all options in this submenu will be skipped and 749 disabled, and Linux guest support won't be built in. 750 751if HYPERVISOR_GUEST 752 753config PARAVIRT 754 bool "Enable paravirtualization code" 755 ---help--- 756 This changes the kernel so it can modify itself when it is run 757 under a hypervisor, potentially improving performance significantly 758 over full virtualization. However, when run without a hypervisor 759 the kernel is theoretically slower and slightly larger. 760 761config PARAVIRT_XXL 762 bool 763 764config PARAVIRT_DEBUG 765 bool "paravirt-ops debugging" 766 depends on PARAVIRT && DEBUG_KERNEL 767 ---help--- 768 Enable to debug paravirt_ops internals. Specifically, BUG if 769 a paravirt_op is missing when it is called. 770 771config PARAVIRT_SPINLOCKS 772 bool "Paravirtualization layer for spinlocks" 773 depends on PARAVIRT && SMP 774 ---help--- 775 Paravirtualized spinlocks allow a pvops backend to replace the 776 spinlock implementation with something virtualization-friendly 777 (for example, block the virtual CPU rather than spinning). 778 779 It has a minimal impact on native kernels and gives a nice performance 780 benefit on paravirtualized KVM / Xen kernels. 781 782 If you are unsure how to answer this question, answer Y. 783 784source "arch/x86/xen/Kconfig" 785 786config KVM_GUEST 787 bool "KVM Guest support (including kvmclock)" 788 depends on PARAVIRT 789 select PARAVIRT_CLOCK 790 default y 791 ---help--- 792 This option enables various optimizations for running under the KVM 793 hypervisor. It includes a paravirtualized clock, so that instead 794 of relying on a PIT (or probably other) emulation by the 795 underlying device model, the host provides the guest with 796 timing infrastructure such as time of day, and system time 797 798config PVH 799 bool "Support for running PVH guests" 800 ---help--- 801 This option enables the PVH entry point for guest virtual machines 802 as specified in the x86/HVM direct boot ABI. 803 804config KVM_DEBUG_FS 805 bool "Enable debug information for KVM Guests in debugfs" 806 depends on KVM_GUEST && DEBUG_FS 807 ---help--- 808 This option enables collection of various statistics for KVM guest. 809 Statistics are displayed in debugfs filesystem. Enabling this option 810 may incur significant overhead. 811 812config PARAVIRT_TIME_ACCOUNTING 813 bool "Paravirtual steal time accounting" 814 depends on PARAVIRT 815 ---help--- 816 Select this option to enable fine granularity task steal time 817 accounting. Time spent executing other tasks in parallel with 818 the current vCPU is discounted from the vCPU power. To account for 819 that, there can be a small performance impact. 820 821 If in doubt, say N here. 822 823config PARAVIRT_CLOCK 824 bool 825 826config JAILHOUSE_GUEST 827 bool "Jailhouse non-root cell support" 828 depends on X86_64 && PCI 829 select X86_PM_TIMER 830 ---help--- 831 This option allows to run Linux as guest in a Jailhouse non-root 832 cell. You can leave this option disabled if you only want to start 833 Jailhouse and run Linux afterwards in the root cell. 834 835endif #HYPERVISOR_GUEST 836 837source "arch/x86/Kconfig.cpu" 838 839config HPET_TIMER 840 def_bool X86_64 841 prompt "HPET Timer Support" if X86_32 842 ---help--- 843 Use the IA-PC HPET (High Precision Event Timer) to manage 844 time in preference to the PIT and RTC, if a HPET is 845 present. 846 HPET is the next generation timer replacing legacy 8254s. 847 The HPET provides a stable time base on SMP 848 systems, unlike the TSC, but it is more expensive to access, 849 as it is off-chip. The interface used is documented 850 in the HPET spec, revision 1. 851 852 You can safely choose Y here. However, HPET will only be 853 activated if the platform and the BIOS support this feature. 854 Otherwise the 8254 will be used for timing services. 855 856 Choose N to continue using the legacy 8254 timer. 857 858config HPET_EMULATE_RTC 859 def_bool y 860 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 861 862config APB_TIMER 863 def_bool y if X86_INTEL_MID 864 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 865 select DW_APB_TIMER 866 depends on X86_INTEL_MID && SFI 867 help 868 APB timer is the replacement for 8254, HPET on X86 MID platforms. 869 The APBT provides a stable time base on SMP 870 systems, unlike the TSC, but it is more expensive to access, 871 as it is off-chip. APB timers are always running regardless of CPU 872 C states, they are used as per CPU clockevent device when possible. 873 874# Mark as expert because too many people got it wrong. 875# The code disables itself when not needed. 876config DMI 877 default y 878 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 879 bool "Enable DMI scanning" if EXPERT 880 ---help--- 881 Enabled scanning of DMI to identify machine quirks. Say Y 882 here unless you have verified that your setup is not 883 affected by entries in the DMI blacklist. Required by PNP 884 BIOS code. 885 886config GART_IOMMU 887 bool "Old AMD GART IOMMU support" 888 select IOMMU_HELPER 889 select SWIOTLB 890 depends on X86_64 && PCI && AMD_NB 891 ---help--- 892 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 893 GART based hardware IOMMUs. 894 895 The GART supports full DMA access for devices with 32-bit access 896 limitations, on systems with more than 3 GB. This is usually needed 897 for USB, sound, many IDE/SATA chipsets and some other devices. 898 899 Newer systems typically have a modern AMD IOMMU, supported via 900 the CONFIG_AMD_IOMMU=y config option. 901 902 In normal configurations this driver is only active when needed: 903 there's more than 3 GB of memory and the system contains a 904 32-bit limited device. 905 906 If unsure, say Y. 907 908config CALGARY_IOMMU 909 bool "IBM Calgary IOMMU support" 910 select IOMMU_HELPER 911 select SWIOTLB 912 depends on X86_64 && PCI 913 ---help--- 914 Support for hardware IOMMUs in IBM's xSeries x366 and x460 915 systems. Needed to run systems with more than 3GB of memory 916 properly with 32-bit PCI devices that do not support DAC 917 (Double Address Cycle). Calgary also supports bus level 918 isolation, where all DMAs pass through the IOMMU. This 919 prevents them from going anywhere except their intended 920 destination. This catches hard-to-find kernel bugs and 921 mis-behaving drivers and devices that do not use the DMA-API 922 properly to set up their DMA buffers. The IOMMU can be 923 turned off at boot time with the iommu=off parameter. 924 Normally the kernel will make the right choice by itself. 925 If unsure, say Y. 926 927config CALGARY_IOMMU_ENABLED_BY_DEFAULT 928 def_bool y 929 prompt "Should Calgary be enabled by default?" 930 depends on CALGARY_IOMMU 931 ---help--- 932 Should Calgary be enabled by default? if you choose 'y', Calgary 933 will be used (if it exists). If you choose 'n', Calgary will not be 934 used even if it exists. If you choose 'n' and would like to use 935 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 936 If unsure, say Y. 937 938config MAXSMP 939 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 940 depends on X86_64 && SMP && DEBUG_KERNEL 941 select CPUMASK_OFFSTACK 942 ---help--- 943 Enable maximum number of CPUS and NUMA Nodes for this architecture. 944 If unsure, say N. 945 946# 947# The maximum number of CPUs supported: 948# 949# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 950# and which can be configured interactively in the 951# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 952# 953# The ranges are different on 32-bit and 64-bit kernels, depending on 954# hardware capabilities and scalability features of the kernel. 955# 956# ( If MAXSMP is enabled we just use the highest possible value and disable 957# interactive configuration. ) 958# 959 960config NR_CPUS_RANGE_BEGIN 961 int 962 default NR_CPUS_RANGE_END if MAXSMP 963 default 1 if !SMP 964 default 2 965 966config NR_CPUS_RANGE_END 967 int 968 depends on X86_32 969 default 64 if SMP && X86_BIGSMP 970 default 8 if SMP && !X86_BIGSMP 971 default 1 if !SMP 972 973config NR_CPUS_RANGE_END 974 int 975 depends on X86_64 976 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 977 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 978 default 1 if !SMP 979 980config NR_CPUS_DEFAULT 981 int 982 depends on X86_32 983 default 32 if X86_BIGSMP 984 default 8 if SMP 985 default 1 if !SMP 986 987config NR_CPUS_DEFAULT 988 int 989 depends on X86_64 990 default 8192 if MAXSMP 991 default 64 if SMP 992 default 1 if !SMP 993 994config NR_CPUS 995 int "Maximum number of CPUs" if SMP && !MAXSMP 996 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 997 default NR_CPUS_DEFAULT 998 ---help--- 999 This allows you to specify the maximum number of CPUs which this 1000 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1001 supported value is 8192, otherwise the maximum value is 512. The 1002 minimum value which makes sense is 2. 1003 1004 This is purely to save memory: each supported CPU adds about 8KB 1005 to the kernel image. 1006 1007config SCHED_SMT 1008 def_bool y if SMP 1009 1010config SCHED_MC 1011 def_bool y 1012 prompt "Multi-core scheduler support" 1013 depends on SMP 1014 ---help--- 1015 Multi-core scheduler support improves the CPU scheduler's decision 1016 making when dealing with multi-core CPU chips at a cost of slightly 1017 increased overhead in some places. If unsure say N here. 1018 1019config SCHED_MC_PRIO 1020 bool "CPU core priorities scheduler support" 1021 depends on SCHED_MC && CPU_SUP_INTEL 1022 select X86_INTEL_PSTATE 1023 select CPU_FREQ 1024 default y 1025 ---help--- 1026 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1027 core ordering determined at manufacturing time, which allows 1028 certain cores to reach higher turbo frequencies (when running 1029 single threaded workloads) than others. 1030 1031 Enabling this kernel feature teaches the scheduler about 1032 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1033 scheduler's CPU selection logic accordingly, so that higher 1034 overall system performance can be achieved. 1035 1036 This feature will have no effect on CPUs without this feature. 1037 1038 If unsure say Y here. 1039 1040config UP_LATE_INIT 1041 def_bool y 1042 depends on !SMP && X86_LOCAL_APIC 1043 1044config X86_UP_APIC 1045 bool "Local APIC support on uniprocessors" if !PCI_MSI 1046 default PCI_MSI 1047 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1048 ---help--- 1049 A local APIC (Advanced Programmable Interrupt Controller) is an 1050 integrated interrupt controller in the CPU. If you have a single-CPU 1051 system which has a processor with a local APIC, you can say Y here to 1052 enable and use it. If you say Y here even though your machine doesn't 1053 have a local APIC, then the kernel will still run with no slowdown at 1054 all. The local APIC supports CPU-generated self-interrupts (timer, 1055 performance counters), and the NMI watchdog which detects hard 1056 lockups. 1057 1058config X86_UP_IOAPIC 1059 bool "IO-APIC support on uniprocessors" 1060 depends on X86_UP_APIC 1061 ---help--- 1062 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1063 SMP-capable replacement for PC-style interrupt controllers. Most 1064 SMP systems and many recent uniprocessor systems have one. 1065 1066 If you have a single-CPU system with an IO-APIC, you can say Y here 1067 to use it. If you say Y here even though your machine doesn't have 1068 an IO-APIC, then the kernel will still run with no slowdown at all. 1069 1070config X86_LOCAL_APIC 1071 def_bool y 1072 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1073 select IRQ_DOMAIN_HIERARCHY 1074 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1075 1076config X86_IO_APIC 1077 def_bool y 1078 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1079 1080config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1081 bool "Reroute for broken boot IRQs" 1082 depends on X86_IO_APIC 1083 ---help--- 1084 This option enables a workaround that fixes a source of 1085 spurious interrupts. This is recommended when threaded 1086 interrupt handling is used on systems where the generation of 1087 superfluous "boot interrupts" cannot be disabled. 1088 1089 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1090 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1091 kernel does during interrupt handling). On chipsets where this 1092 boot IRQ generation cannot be disabled, this workaround keeps 1093 the original IRQ line masked so that only the equivalent "boot 1094 IRQ" is delivered to the CPUs. The workaround also tells the 1095 kernel to set up the IRQ handler on the boot IRQ line. In this 1096 way only one interrupt is delivered to the kernel. Otherwise 1097 the spurious second interrupt may cause the kernel to bring 1098 down (vital) interrupt lines. 1099 1100 Only affects "broken" chipsets. Interrupt sharing may be 1101 increased on these systems. 1102 1103config X86_MCE 1104 bool "Machine Check / overheating reporting" 1105 select GENERIC_ALLOCATOR 1106 default y 1107 ---help--- 1108 Machine Check support allows the processor to notify the 1109 kernel if it detects a problem (e.g. overheating, data corruption). 1110 The action the kernel takes depends on the severity of the problem, 1111 ranging from warning messages to halting the machine. 1112 1113config X86_MCELOG_LEGACY 1114 bool "Support for deprecated /dev/mcelog character device" 1115 depends on X86_MCE 1116 ---help--- 1117 Enable support for /dev/mcelog which is needed by the old mcelog 1118 userspace logging daemon. Consider switching to the new generation 1119 rasdaemon solution. 1120 1121config X86_MCE_INTEL 1122 def_bool y 1123 prompt "Intel MCE features" 1124 depends on X86_MCE && X86_LOCAL_APIC 1125 ---help--- 1126 Additional support for intel specific MCE features such as 1127 the thermal monitor. 1128 1129config X86_MCE_AMD 1130 def_bool y 1131 prompt "AMD MCE features" 1132 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1133 ---help--- 1134 Additional support for AMD specific MCE features such as 1135 the DRAM Error Threshold. 1136 1137config X86_ANCIENT_MCE 1138 bool "Support for old Pentium 5 / WinChip machine checks" 1139 depends on X86_32 && X86_MCE 1140 ---help--- 1141 Include support for machine check handling on old Pentium 5 or WinChip 1142 systems. These typically need to be enabled explicitly on the command 1143 line. 1144 1145config X86_MCE_THRESHOLD 1146 depends on X86_MCE_AMD || X86_MCE_INTEL 1147 def_bool y 1148 1149config X86_MCE_INJECT 1150 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1151 tristate "Machine check injector support" 1152 ---help--- 1153 Provide support for injecting machine checks for testing purposes. 1154 If you don't know what a machine check is and you don't do kernel 1155 QA it is safe to say n. 1156 1157config X86_THERMAL_VECTOR 1158 def_bool y 1159 depends on X86_MCE_INTEL 1160 1161source "arch/x86/events/Kconfig" 1162 1163config X86_LEGACY_VM86 1164 bool "Legacy VM86 support" 1165 depends on X86_32 1166 ---help--- 1167 This option allows user programs to put the CPU into V8086 1168 mode, which is an 80286-era approximation of 16-bit real mode. 1169 1170 Some very old versions of X and/or vbetool require this option 1171 for user mode setting. Similarly, DOSEMU will use it if 1172 available to accelerate real mode DOS programs. However, any 1173 recent version of DOSEMU, X, or vbetool should be fully 1174 functional even without kernel VM86 support, as they will all 1175 fall back to software emulation. Nevertheless, if you are using 1176 a 16-bit DOS program where 16-bit performance matters, vm86 1177 mode might be faster than emulation and you might want to 1178 enable this option. 1179 1180 Note that any app that works on a 64-bit kernel is unlikely to 1181 need this option, as 64-bit kernels don't, and can't, support 1182 V8086 mode. This option is also unrelated to 16-bit protected 1183 mode and is not needed to run most 16-bit programs under Wine. 1184 1185 Enabling this option increases the complexity of the kernel 1186 and slows down exception handling a tiny bit. 1187 1188 If unsure, say N here. 1189 1190config VM86 1191 bool 1192 default X86_LEGACY_VM86 1193 1194config X86_16BIT 1195 bool "Enable support for 16-bit segments" if EXPERT 1196 default y 1197 depends on MODIFY_LDT_SYSCALL 1198 ---help--- 1199 This option is required by programs like Wine to run 16-bit 1200 protected mode legacy code on x86 processors. Disabling 1201 this option saves about 300 bytes on i386, or around 6K text 1202 plus 16K runtime memory on x86-64, 1203 1204config X86_ESPFIX32 1205 def_bool y 1206 depends on X86_16BIT && X86_32 1207 1208config X86_ESPFIX64 1209 def_bool y 1210 depends on X86_16BIT && X86_64 1211 1212config X86_VSYSCALL_EMULATION 1213 bool "Enable vsyscall emulation" if EXPERT 1214 default y 1215 depends on X86_64 1216 ---help--- 1217 This enables emulation of the legacy vsyscall page. Disabling 1218 it is roughly equivalent to booting with vsyscall=none, except 1219 that it will also disable the helpful warning if a program 1220 tries to use a vsyscall. With this option set to N, offending 1221 programs will just segfault, citing addresses of the form 1222 0xffffffffff600?00. 1223 1224 This option is required by many programs built before 2013, and 1225 care should be used even with newer programs if set to N. 1226 1227 Disabling this option saves about 7K of kernel size and 1228 possibly 4K of additional runtime pagetable memory. 1229 1230config TOSHIBA 1231 tristate "Toshiba Laptop support" 1232 depends on X86_32 1233 ---help--- 1234 This adds a driver to safely access the System Management Mode of 1235 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1236 not work on models with a Phoenix BIOS. The System Management Mode 1237 is used to set the BIOS and power saving options on Toshiba portables. 1238 1239 For information on utilities to make use of this driver see the 1240 Toshiba Linux utilities web site at: 1241 <http://www.buzzard.org.uk/toshiba/>. 1242 1243 Say Y if you intend to run this kernel on a Toshiba portable. 1244 Say N otherwise. 1245 1246config I8K 1247 tristate "Dell i8k legacy laptop support" 1248 select HWMON 1249 select SENSORS_DELL_SMM 1250 ---help--- 1251 This option enables legacy /proc/i8k userspace interface in hwmon 1252 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1253 temperature and allows controlling fan speeds of Dell laptops via 1254 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1255 it reports also power and hotkey status. For fan speed control is 1256 needed userspace package i8kutils. 1257 1258 Say Y if you intend to run this kernel on old Dell laptops or want to 1259 use userspace package i8kutils. 1260 Say N otherwise. 1261 1262config X86_REBOOTFIXUPS 1263 bool "Enable X86 board specific fixups for reboot" 1264 depends on X86_32 1265 ---help--- 1266 This enables chipset and/or board specific fixups to be done 1267 in order to get reboot to work correctly. This is only needed on 1268 some combinations of hardware and BIOS. The symptom, for which 1269 this config is intended, is when reboot ends with a stalled/hung 1270 system. 1271 1272 Currently, the only fixup is for the Geode machines using 1273 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1274 1275 Say Y if you want to enable the fixup. Currently, it's safe to 1276 enable this option even if you don't need it. 1277 Say N otherwise. 1278 1279config MICROCODE 1280 bool "CPU microcode loading support" 1281 default y 1282 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1283 select FW_LOADER 1284 ---help--- 1285 If you say Y here, you will be able to update the microcode on 1286 Intel and AMD processors. The Intel support is for the IA32 family, 1287 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1288 AMD support is for families 0x10 and later. You will obviously need 1289 the actual microcode binary data itself which is not shipped with 1290 the Linux kernel. 1291 1292 The preferred method to load microcode from a detached initrd is described 1293 in Documentation/x86/microcode.txt. For that you need to enable 1294 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1295 initrd for microcode blobs. 1296 1297 In addition, you can build the microcode into the kernel. For that you 1298 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1299 config option. 1300 1301config MICROCODE_INTEL 1302 bool "Intel microcode loading support" 1303 depends on MICROCODE 1304 default MICROCODE 1305 select FW_LOADER 1306 ---help--- 1307 This options enables microcode patch loading support for Intel 1308 processors. 1309 1310 For the current Intel microcode data package go to 1311 <https://downloadcenter.intel.com> and search for 1312 'Linux Processor Microcode Data File'. 1313 1314config MICROCODE_AMD 1315 bool "AMD microcode loading support" 1316 depends on MICROCODE 1317 select FW_LOADER 1318 ---help--- 1319 If you select this option, microcode patch loading support for AMD 1320 processors will be enabled. 1321 1322config MICROCODE_OLD_INTERFACE 1323 bool "Ancient loading interface (DEPRECATED)" 1324 default n 1325 depends on MICROCODE 1326 ---help--- 1327 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1328 which was used by userspace tools like iucode_tool and microcode.ctl. 1329 It is inadequate because it runs too late to be able to properly 1330 load microcode on a machine and it needs special tools. Instead, you 1331 should've switched to the early loading method with the initrd or 1332 builtin microcode by now: Documentation/x86/microcode.txt 1333 1334config X86_MSR 1335 tristate "/dev/cpu/*/msr - Model-specific register support" 1336 ---help--- 1337 This device gives privileged processes access to the x86 1338 Model-Specific Registers (MSRs). It is a character device with 1339 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1340 MSR accesses are directed to a specific CPU on multi-processor 1341 systems. 1342 1343config X86_CPUID 1344 tristate "/dev/cpu/*/cpuid - CPU information support" 1345 ---help--- 1346 This device gives processes access to the x86 CPUID instruction to 1347 be executed on a specific processor. It is a character device 1348 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1349 /dev/cpu/31/cpuid. 1350 1351choice 1352 prompt "High Memory Support" 1353 default HIGHMEM4G 1354 depends on X86_32 1355 1356config NOHIGHMEM 1357 bool "off" 1358 ---help--- 1359 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1360 However, the address space of 32-bit x86 processors is only 4 1361 Gigabytes large. That means that, if you have a large amount of 1362 physical memory, not all of it can be "permanently mapped" by the 1363 kernel. The physical memory that's not permanently mapped is called 1364 "high memory". 1365 1366 If you are compiling a kernel which will never run on a machine with 1367 more than 1 Gigabyte total physical RAM, answer "off" here (default 1368 choice and suitable for most users). This will result in a "3GB/1GB" 1369 split: 3GB are mapped so that each process sees a 3GB virtual memory 1370 space and the remaining part of the 4GB virtual memory space is used 1371 by the kernel to permanently map as much physical memory as 1372 possible. 1373 1374 If the machine has between 1 and 4 Gigabytes physical RAM, then 1375 answer "4GB" here. 1376 1377 If more than 4 Gigabytes is used then answer "64GB" here. This 1378 selection turns Intel PAE (Physical Address Extension) mode on. 1379 PAE implements 3-level paging on IA32 processors. PAE is fully 1380 supported by Linux, PAE mode is implemented on all recent Intel 1381 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1382 then the kernel will not boot on CPUs that don't support PAE! 1383 1384 The actual amount of total physical memory will either be 1385 auto detected or can be forced by using a kernel command line option 1386 such as "mem=256M". (Try "man bootparam" or see the documentation of 1387 your boot loader (lilo or loadlin) about how to pass options to the 1388 kernel at boot time.) 1389 1390 If unsure, say "off". 1391 1392config HIGHMEM4G 1393 bool "4GB" 1394 ---help--- 1395 Select this if you have a 32-bit processor and between 1 and 4 1396 gigabytes of physical RAM. 1397 1398config HIGHMEM64G 1399 bool "64GB" 1400 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1401 select X86_PAE 1402 ---help--- 1403 Select this if you have a 32-bit processor and more than 4 1404 gigabytes of physical RAM. 1405 1406endchoice 1407 1408choice 1409 prompt "Memory split" if EXPERT 1410 default VMSPLIT_3G 1411 depends on X86_32 1412 ---help--- 1413 Select the desired split between kernel and user memory. 1414 1415 If the address range available to the kernel is less than the 1416 physical memory installed, the remaining memory will be available 1417 as "high memory". Accessing high memory is a little more costly 1418 than low memory, as it needs to be mapped into the kernel first. 1419 Note that increasing the kernel address space limits the range 1420 available to user programs, making the address space there 1421 tighter. Selecting anything other than the default 3G/1G split 1422 will also likely make your kernel incompatible with binary-only 1423 kernel modules. 1424 1425 If you are not absolutely sure what you are doing, leave this 1426 option alone! 1427 1428 config VMSPLIT_3G 1429 bool "3G/1G user/kernel split" 1430 config VMSPLIT_3G_OPT 1431 depends on !X86_PAE 1432 bool "3G/1G user/kernel split (for full 1G low memory)" 1433 config VMSPLIT_2G 1434 bool "2G/2G user/kernel split" 1435 config VMSPLIT_2G_OPT 1436 depends on !X86_PAE 1437 bool "2G/2G user/kernel split (for full 2G low memory)" 1438 config VMSPLIT_1G 1439 bool "1G/3G user/kernel split" 1440endchoice 1441 1442config PAGE_OFFSET 1443 hex 1444 default 0xB0000000 if VMSPLIT_3G_OPT 1445 default 0x80000000 if VMSPLIT_2G 1446 default 0x78000000 if VMSPLIT_2G_OPT 1447 default 0x40000000 if VMSPLIT_1G 1448 default 0xC0000000 1449 depends on X86_32 1450 1451config HIGHMEM 1452 def_bool y 1453 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1454 1455config X86_PAE 1456 bool "PAE (Physical Address Extension) Support" 1457 depends on X86_32 && !HIGHMEM4G 1458 select PHYS_ADDR_T_64BIT 1459 select SWIOTLB 1460 ---help--- 1461 PAE is required for NX support, and furthermore enables 1462 larger swapspace support for non-overcommit purposes. It 1463 has the cost of more pagetable lookup overhead, and also 1464 consumes more pagetable space per process. 1465 1466config X86_5LEVEL 1467 bool "Enable 5-level page tables support" 1468 select DYNAMIC_MEMORY_LAYOUT 1469 select SPARSEMEM_VMEMMAP 1470 depends on X86_64 1471 ---help--- 1472 5-level paging enables access to larger address space: 1473 upto 128 PiB of virtual address space and 4 PiB of 1474 physical address space. 1475 1476 It will be supported by future Intel CPUs. 1477 1478 A kernel with the option enabled can be booted on machines that 1479 support 4- or 5-level paging. 1480 1481 See Documentation/x86/x86_64/5level-paging.txt for more 1482 information. 1483 1484 Say N if unsure. 1485 1486config X86_DIRECT_GBPAGES 1487 def_bool y 1488 depends on X86_64 && !DEBUG_PAGEALLOC 1489 ---help--- 1490 Certain kernel features effectively disable kernel 1491 linear 1 GB mappings (even if the CPU otherwise 1492 supports them), so don't confuse the user by printing 1493 that we have them enabled. 1494 1495config X86_CPA_STATISTICS 1496 bool "Enable statistic for Change Page Attribute" 1497 depends on DEBUG_FS 1498 ---help--- 1499 Expose statistics about the Change Page Attribute mechanims, which 1500 helps to determine the effectiveness of preserving large and huge 1501 page mappings when mapping protections are changed. 1502 1503config ARCH_HAS_MEM_ENCRYPT 1504 def_bool y 1505 1506config AMD_MEM_ENCRYPT 1507 bool "AMD Secure Memory Encryption (SME) support" 1508 depends on X86_64 && CPU_SUP_AMD 1509 select DYNAMIC_PHYSICAL_MASK 1510 select ARCH_USE_MEMREMAP_PROT 1511 ---help--- 1512 Say yes to enable support for the encryption of system memory. 1513 This requires an AMD processor that supports Secure Memory 1514 Encryption (SME). 1515 1516config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1517 bool "Activate AMD Secure Memory Encryption (SME) by default" 1518 default y 1519 depends on AMD_MEM_ENCRYPT 1520 ---help--- 1521 Say yes to have system memory encrypted by default if running on 1522 an AMD processor that supports Secure Memory Encryption (SME). 1523 1524 If set to Y, then the encryption of system memory can be 1525 deactivated with the mem_encrypt=off command line option. 1526 1527 If set to N, then the encryption of system memory can be 1528 activated with the mem_encrypt=on command line option. 1529 1530# Common NUMA Features 1531config NUMA 1532 bool "Numa Memory Allocation and Scheduler Support" 1533 depends on SMP 1534 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1535 default y if X86_BIGSMP 1536 ---help--- 1537 Enable NUMA (Non Uniform Memory Access) support. 1538 1539 The kernel will try to allocate memory used by a CPU on the 1540 local memory controller of the CPU and add some more 1541 NUMA awareness to the kernel. 1542 1543 For 64-bit this is recommended if the system is Intel Core i7 1544 (or later), AMD Opteron, or EM64T NUMA. 1545 1546 For 32-bit this is only needed if you boot a 32-bit 1547 kernel on a 64-bit NUMA platform. 1548 1549 Otherwise, you should say N. 1550 1551config AMD_NUMA 1552 def_bool y 1553 prompt "Old style AMD Opteron NUMA detection" 1554 depends on X86_64 && NUMA && PCI 1555 ---help--- 1556 Enable AMD NUMA node topology detection. You should say Y here if 1557 you have a multi processor AMD system. This uses an old method to 1558 read the NUMA configuration directly from the builtin Northbridge 1559 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1560 which also takes priority if both are compiled in. 1561 1562config X86_64_ACPI_NUMA 1563 def_bool y 1564 prompt "ACPI NUMA detection" 1565 depends on X86_64 && NUMA && ACPI && PCI 1566 select ACPI_NUMA 1567 ---help--- 1568 Enable ACPI SRAT based node topology detection. 1569 1570# Some NUMA nodes have memory ranges that span 1571# other nodes. Even though a pfn is valid and 1572# between a node's start and end pfns, it may not 1573# reside on that node. See memmap_init_zone() 1574# for details. 1575config NODES_SPAN_OTHER_NODES 1576 def_bool y 1577 depends on X86_64_ACPI_NUMA 1578 1579config NUMA_EMU 1580 bool "NUMA emulation" 1581 depends on NUMA 1582 ---help--- 1583 Enable NUMA emulation. A flat machine will be split 1584 into virtual nodes when booted with "numa=fake=N", where N is the 1585 number of nodes. This is only useful for debugging. 1586 1587config NODES_SHIFT 1588 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1589 range 1 10 1590 default "10" if MAXSMP 1591 default "6" if X86_64 1592 default "3" 1593 depends on NEED_MULTIPLE_NODES 1594 ---help--- 1595 Specify the maximum number of NUMA Nodes available on the target 1596 system. Increases memory reserved to accommodate various tables. 1597 1598config ARCH_HAVE_MEMORY_PRESENT 1599 def_bool y 1600 depends on X86_32 && DISCONTIGMEM 1601 1602config ARCH_FLATMEM_ENABLE 1603 def_bool y 1604 depends on X86_32 && !NUMA 1605 1606config ARCH_DISCONTIGMEM_ENABLE 1607 def_bool n 1608 depends on NUMA && X86_32 1609 depends on BROKEN 1610 1611config ARCH_SPARSEMEM_ENABLE 1612 def_bool y 1613 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1614 select SPARSEMEM_STATIC if X86_32 1615 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1616 1617config ARCH_SPARSEMEM_DEFAULT 1618 def_bool X86_64 || (NUMA && X86_32) 1619 1620config ARCH_SELECT_MEMORY_MODEL 1621 def_bool y 1622 depends on ARCH_SPARSEMEM_ENABLE 1623 1624config ARCH_MEMORY_PROBE 1625 bool "Enable sysfs memory/probe interface" 1626 depends on X86_64 && MEMORY_HOTPLUG 1627 help 1628 This option enables a sysfs memory/probe interface for testing. 1629 See Documentation/memory-hotplug.txt for more information. 1630 If you are unsure how to answer this question, answer N. 1631 1632config ARCH_PROC_KCORE_TEXT 1633 def_bool y 1634 depends on X86_64 && PROC_KCORE 1635 1636config ILLEGAL_POINTER_VALUE 1637 hex 1638 default 0 if X86_32 1639 default 0xdead000000000000 if X86_64 1640 1641config X86_PMEM_LEGACY_DEVICE 1642 bool 1643 1644config X86_PMEM_LEGACY 1645 tristate "Support non-standard NVDIMMs and ADR protected memory" 1646 depends on PHYS_ADDR_T_64BIT 1647 depends on BLK_DEV 1648 select X86_PMEM_LEGACY_DEVICE 1649 select LIBNVDIMM 1650 help 1651 Treat memory marked using the non-standard e820 type of 12 as used 1652 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1653 The kernel will offer these regions to the 'pmem' driver so 1654 they can be used for persistent storage. 1655 1656 Say Y if unsure. 1657 1658config HIGHPTE 1659 bool "Allocate 3rd-level pagetables from highmem" 1660 depends on HIGHMEM 1661 ---help--- 1662 The VM uses one page table entry for each page of physical memory. 1663 For systems with a lot of RAM, this can be wasteful of precious 1664 low memory. Setting this option will put user-space page table 1665 entries in high memory. 1666 1667config X86_CHECK_BIOS_CORRUPTION 1668 bool "Check for low memory corruption" 1669 ---help--- 1670 Periodically check for memory corruption in low memory, which 1671 is suspected to be caused by BIOS. Even when enabled in the 1672 configuration, it is disabled at runtime. Enable it by 1673 setting "memory_corruption_check=1" on the kernel command 1674 line. By default it scans the low 64k of memory every 60 1675 seconds; see the memory_corruption_check_size and 1676 memory_corruption_check_period parameters in 1677 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1678 1679 When enabled with the default parameters, this option has 1680 almost no overhead, as it reserves a relatively small amount 1681 of memory and scans it infrequently. It both detects corruption 1682 and prevents it from affecting the running system. 1683 1684 It is, however, intended as a diagnostic tool; if repeatable 1685 BIOS-originated corruption always affects the same memory, 1686 you can use memmap= to prevent the kernel from using that 1687 memory. 1688 1689config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1690 bool "Set the default setting of memory_corruption_check" 1691 depends on X86_CHECK_BIOS_CORRUPTION 1692 default y 1693 ---help--- 1694 Set whether the default state of memory_corruption_check is 1695 on or off. 1696 1697config X86_RESERVE_LOW 1698 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1699 default 64 1700 range 4 640 1701 ---help--- 1702 Specify the amount of low memory to reserve for the BIOS. 1703 1704 The first page contains BIOS data structures that the kernel 1705 must not use, so that page must always be reserved. 1706 1707 By default we reserve the first 64K of physical RAM, as a 1708 number of BIOSes are known to corrupt that memory range 1709 during events such as suspend/resume or monitor cable 1710 insertion, so it must not be used by the kernel. 1711 1712 You can set this to 4 if you are absolutely sure that you 1713 trust the BIOS to get all its memory reservations and usages 1714 right. If you know your BIOS have problems beyond the 1715 default 64K area, you can set this to 640 to avoid using the 1716 entire low memory range. 1717 1718 If you have doubts about the BIOS (e.g. suspend/resume does 1719 not work or there's kernel crashes after certain hardware 1720 hotplug events) then you might want to enable 1721 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1722 typical corruption patterns. 1723 1724 Leave this to the default value of 64 if you are unsure. 1725 1726config MATH_EMULATION 1727 bool 1728 depends on MODIFY_LDT_SYSCALL 1729 prompt "Math emulation" if X86_32 1730 ---help--- 1731 Linux can emulate a math coprocessor (used for floating point 1732 operations) if you don't have one. 486DX and Pentium processors have 1733 a math coprocessor built in, 486SX and 386 do not, unless you added 1734 a 487DX or 387, respectively. (The messages during boot time can 1735 give you some hints here ["man dmesg"].) Everyone needs either a 1736 coprocessor or this emulation. 1737 1738 If you don't have a math coprocessor, you need to say Y here; if you 1739 say Y here even though you have a coprocessor, the coprocessor will 1740 be used nevertheless. (This behavior can be changed with the kernel 1741 command line option "no387", which comes handy if your coprocessor 1742 is broken. Try "man bootparam" or see the documentation of your boot 1743 loader (lilo or loadlin) about how to pass options to the kernel at 1744 boot time.) This means that it is a good idea to say Y here if you 1745 intend to use this kernel on different machines. 1746 1747 More information about the internals of the Linux math coprocessor 1748 emulation can be found in <file:arch/x86/math-emu/README>. 1749 1750 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1751 kernel, it won't hurt. 1752 1753config MTRR 1754 def_bool y 1755 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1756 ---help--- 1757 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1758 the Memory Type Range Registers (MTRRs) may be used to control 1759 processor access to memory ranges. This is most useful if you have 1760 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1761 allows bus write transfers to be combined into a larger transfer 1762 before bursting over the PCI/AGP bus. This can increase performance 1763 of image write operations 2.5 times or more. Saying Y here creates a 1764 /proc/mtrr file which may be used to manipulate your processor's 1765 MTRRs. Typically the X server should use this. 1766 1767 This code has a reasonably generic interface so that similar 1768 control registers on other processors can be easily supported 1769 as well: 1770 1771 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1772 Registers (ARRs) which provide a similar functionality to MTRRs. For 1773 these, the ARRs are used to emulate the MTRRs. 1774 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1775 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1776 write-combining. All of these processors are supported by this code 1777 and it makes sense to say Y here if you have one of them. 1778 1779 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1780 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1781 can lead to all sorts of problems, so it's good to say Y here. 1782 1783 You can safely say Y even if your machine doesn't have MTRRs, you'll 1784 just add about 9 KB to your kernel. 1785 1786 See <file:Documentation/x86/mtrr.txt> for more information. 1787 1788config MTRR_SANITIZER 1789 def_bool y 1790 prompt "MTRR cleanup support" 1791 depends on MTRR 1792 ---help--- 1793 Convert MTRR layout from continuous to discrete, so X drivers can 1794 add writeback entries. 1795 1796 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1797 The largest mtrr entry size for a continuous block can be set with 1798 mtrr_chunk_size. 1799 1800 If unsure, say Y. 1801 1802config MTRR_SANITIZER_ENABLE_DEFAULT 1803 int "MTRR cleanup enable value (0-1)" 1804 range 0 1 1805 default "0" 1806 depends on MTRR_SANITIZER 1807 ---help--- 1808 Enable mtrr cleanup default value 1809 1810config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1811 int "MTRR cleanup spare reg num (0-7)" 1812 range 0 7 1813 default "1" 1814 depends on MTRR_SANITIZER 1815 ---help--- 1816 mtrr cleanup spare entries default, it can be changed via 1817 mtrr_spare_reg_nr=N on the kernel command line. 1818 1819config X86_PAT 1820 def_bool y 1821 prompt "x86 PAT support" if EXPERT 1822 depends on MTRR 1823 ---help--- 1824 Use PAT attributes to setup page level cache control. 1825 1826 PATs are the modern equivalents of MTRRs and are much more 1827 flexible than MTRRs. 1828 1829 Say N here if you see bootup problems (boot crash, boot hang, 1830 spontaneous reboots) or a non-working video driver. 1831 1832 If unsure, say Y. 1833 1834config ARCH_USES_PG_UNCACHED 1835 def_bool y 1836 depends on X86_PAT 1837 1838config ARCH_RANDOM 1839 def_bool y 1840 prompt "x86 architectural random number generator" if EXPERT 1841 ---help--- 1842 Enable the x86 architectural RDRAND instruction 1843 (Intel Bull Mountain technology) to generate random numbers. 1844 If supported, this is a high bandwidth, cryptographically 1845 secure hardware random number generator. 1846 1847config X86_SMAP 1848 def_bool y 1849 prompt "Supervisor Mode Access Prevention" if EXPERT 1850 ---help--- 1851 Supervisor Mode Access Prevention (SMAP) is a security 1852 feature in newer Intel processors. There is a small 1853 performance cost if this enabled and turned on; there is 1854 also a small increase in the kernel size if this is enabled. 1855 1856 If unsure, say Y. 1857 1858config X86_INTEL_UMIP 1859 def_bool y 1860 depends on CPU_SUP_INTEL 1861 prompt "Intel User Mode Instruction Prevention" if EXPERT 1862 ---help--- 1863 The User Mode Instruction Prevention (UMIP) is a security 1864 feature in newer Intel processors. If enabled, a general 1865 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1866 or STR instructions are executed in user mode. These instructions 1867 unnecessarily expose information about the hardware state. 1868 1869 The vast majority of applications do not use these instructions. 1870 For the very few that do, software emulation is provided in 1871 specific cases in protected and virtual-8086 modes. Emulated 1872 results are dummy. 1873 1874config X86_INTEL_MPX 1875 prompt "Intel MPX (Memory Protection Extensions)" 1876 def_bool n 1877 # Note: only available in 64-bit mode due to VMA flags shortage 1878 depends on CPU_SUP_INTEL && X86_64 1879 select ARCH_USES_HIGH_VMA_FLAGS 1880 ---help--- 1881 MPX provides hardware features that can be used in 1882 conjunction with compiler-instrumented code to check 1883 memory references. It is designed to detect buffer 1884 overflow or underflow bugs. 1885 1886 This option enables running applications which are 1887 instrumented or otherwise use MPX. It does not use MPX 1888 itself inside the kernel or to protect the kernel 1889 against bad memory references. 1890 1891 Enabling this option will make the kernel larger: 1892 ~8k of kernel text and 36 bytes of data on a 64-bit 1893 defconfig. It adds a long to the 'mm_struct' which 1894 will increase the kernel memory overhead of each 1895 process and adds some branches to paths used during 1896 exec() and munmap(). 1897 1898 For details, see Documentation/x86/intel_mpx.txt 1899 1900 If unsure, say N. 1901 1902config X86_INTEL_MEMORY_PROTECTION_KEYS 1903 prompt "Intel Memory Protection Keys" 1904 def_bool y 1905 # Note: only available in 64-bit mode 1906 depends on CPU_SUP_INTEL && X86_64 1907 select ARCH_USES_HIGH_VMA_FLAGS 1908 select ARCH_HAS_PKEYS 1909 ---help--- 1910 Memory Protection Keys provides a mechanism for enforcing 1911 page-based protections, but without requiring modification of the 1912 page tables when an application changes protection domains. 1913 1914 For details, see Documentation/x86/protection-keys.txt 1915 1916 If unsure, say y. 1917 1918config EFI 1919 bool "EFI runtime service support" 1920 depends on ACPI 1921 select UCS2_STRING 1922 select EFI_RUNTIME_WRAPPERS 1923 ---help--- 1924 This enables the kernel to use EFI runtime services that are 1925 available (such as the EFI variable services). 1926 1927 This option is only useful on systems that have EFI firmware. 1928 In addition, you should use the latest ELILO loader available 1929 at <http://elilo.sourceforge.net> in order to take advantage 1930 of EFI runtime services. However, even with this option, the 1931 resultant kernel should continue to boot on existing non-EFI 1932 platforms. 1933 1934config EFI_STUB 1935 bool "EFI stub support" 1936 depends on EFI && !X86_USE_3DNOW 1937 select RELOCATABLE 1938 ---help--- 1939 This kernel feature allows a bzImage to be loaded directly 1940 by EFI firmware without the use of a bootloader. 1941 1942 See Documentation/efi-stub.txt for more information. 1943 1944config EFI_MIXED 1945 bool "EFI mixed-mode support" 1946 depends on EFI_STUB && X86_64 1947 ---help--- 1948 Enabling this feature allows a 64-bit kernel to be booted 1949 on a 32-bit firmware, provided that your CPU supports 64-bit 1950 mode. 1951 1952 Note that it is not possible to boot a mixed-mode enabled 1953 kernel via the EFI boot stub - a bootloader that supports 1954 the EFI handover protocol must be used. 1955 1956 If unsure, say N. 1957 1958config SECCOMP 1959 def_bool y 1960 prompt "Enable seccomp to safely compute untrusted bytecode" 1961 ---help--- 1962 This kernel feature is useful for number crunching applications 1963 that may need to compute untrusted bytecode during their 1964 execution. By using pipes or other transports made available to 1965 the process as file descriptors supporting the read/write 1966 syscalls, it's possible to isolate those applications in 1967 their own address space using seccomp. Once seccomp is 1968 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1969 and the task is only allowed to execute a few safe syscalls 1970 defined by each seccomp mode. 1971 1972 If unsure, say Y. Only embedded should say N here. 1973 1974source "kernel/Kconfig.hz" 1975 1976config KEXEC 1977 bool "kexec system call" 1978 select KEXEC_CORE 1979 ---help--- 1980 kexec is a system call that implements the ability to shutdown your 1981 current kernel, and to start another kernel. It is like a reboot 1982 but it is independent of the system firmware. And like a reboot 1983 you can start any kernel with it, not just Linux. 1984 1985 The name comes from the similarity to the exec system call. 1986 1987 It is an ongoing process to be certain the hardware in a machine 1988 is properly shutdown, so do not be surprised if this code does not 1989 initially work for you. As of this writing the exact hardware 1990 interface is strongly in flux, so no good recommendation can be 1991 made. 1992 1993config KEXEC_FILE 1994 bool "kexec file based system call" 1995 select KEXEC_CORE 1996 select BUILD_BIN2C 1997 depends on X86_64 1998 depends on CRYPTO=y 1999 depends on CRYPTO_SHA256=y 2000 ---help--- 2001 This is new version of kexec system call. This system call is 2002 file based and takes file descriptors as system call argument 2003 for kernel and initramfs as opposed to list of segments as 2004 accepted by previous system call. 2005 2006config ARCH_HAS_KEXEC_PURGATORY 2007 def_bool KEXEC_FILE 2008 2009config KEXEC_VERIFY_SIG 2010 bool "Verify kernel signature during kexec_file_load() syscall" 2011 depends on KEXEC_FILE 2012 ---help--- 2013 This option makes kernel signature verification mandatory for 2014 the kexec_file_load() syscall. 2015 2016 In addition to that option, you need to enable signature 2017 verification for the corresponding kernel image type being 2018 loaded in order for this to work. 2019 2020config KEXEC_BZIMAGE_VERIFY_SIG 2021 bool "Enable bzImage signature verification support" 2022 depends on KEXEC_VERIFY_SIG 2023 depends on SIGNED_PE_FILE_VERIFICATION 2024 select SYSTEM_TRUSTED_KEYRING 2025 ---help--- 2026 Enable bzImage signature verification support. 2027 2028config CRASH_DUMP 2029 bool "kernel crash dumps" 2030 depends on X86_64 || (X86_32 && HIGHMEM) 2031 ---help--- 2032 Generate crash dump after being started by kexec. 2033 This should be normally only set in special crash dump kernels 2034 which are loaded in the main kernel with kexec-tools into 2035 a specially reserved region and then later executed after 2036 a crash by kdump/kexec. The crash dump kernel must be compiled 2037 to a memory address not used by the main kernel or BIOS using 2038 PHYSICAL_START, or it must be built as a relocatable image 2039 (CONFIG_RELOCATABLE=y). 2040 For more details see Documentation/kdump/kdump.txt 2041 2042config KEXEC_JUMP 2043 bool "kexec jump" 2044 depends on KEXEC && HIBERNATION 2045 ---help--- 2046 Jump between original kernel and kexeced kernel and invoke 2047 code in physical address mode via KEXEC 2048 2049config PHYSICAL_START 2050 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2051 default "0x1000000" 2052 ---help--- 2053 This gives the physical address where the kernel is loaded. 2054 2055 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2056 bzImage will decompress itself to above physical address and 2057 run from there. Otherwise, bzImage will run from the address where 2058 it has been loaded by the boot loader and will ignore above physical 2059 address. 2060 2061 In normal kdump cases one does not have to set/change this option 2062 as now bzImage can be compiled as a completely relocatable image 2063 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2064 address. This option is mainly useful for the folks who don't want 2065 to use a bzImage for capturing the crash dump and want to use a 2066 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2067 to be specifically compiled to run from a specific memory area 2068 (normally a reserved region) and this option comes handy. 2069 2070 So if you are using bzImage for capturing the crash dump, 2071 leave the value here unchanged to 0x1000000 and set 2072 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2073 for capturing the crash dump change this value to start of 2074 the reserved region. In other words, it can be set based on 2075 the "X" value as specified in the "crashkernel=YM@XM" 2076 command line boot parameter passed to the panic-ed 2077 kernel. Please take a look at Documentation/kdump/kdump.txt 2078 for more details about crash dumps. 2079 2080 Usage of bzImage for capturing the crash dump is recommended as 2081 one does not have to build two kernels. Same kernel can be used 2082 as production kernel and capture kernel. Above option should have 2083 gone away after relocatable bzImage support is introduced. But it 2084 is present because there are users out there who continue to use 2085 vmlinux for dump capture. This option should go away down the 2086 line. 2087 2088 Don't change this unless you know what you are doing. 2089 2090config RELOCATABLE 2091 bool "Build a relocatable kernel" 2092 default y 2093 ---help--- 2094 This builds a kernel image that retains relocation information 2095 so it can be loaded someplace besides the default 1MB. 2096 The relocations tend to make the kernel binary about 10% larger, 2097 but are discarded at runtime. 2098 2099 One use is for the kexec on panic case where the recovery kernel 2100 must live at a different physical address than the primary 2101 kernel. 2102 2103 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2104 it has been loaded at and the compile time physical address 2105 (CONFIG_PHYSICAL_START) is used as the minimum location. 2106 2107config RANDOMIZE_BASE 2108 bool "Randomize the address of the kernel image (KASLR)" 2109 depends on RELOCATABLE 2110 default y 2111 ---help--- 2112 In support of Kernel Address Space Layout Randomization (KASLR), 2113 this randomizes the physical address at which the kernel image 2114 is decompressed and the virtual address where the kernel 2115 image is mapped, as a security feature that deters exploit 2116 attempts relying on knowledge of the location of kernel 2117 code internals. 2118 2119 On 64-bit, the kernel physical and virtual addresses are 2120 randomized separately. The physical address will be anywhere 2121 between 16MB and the top of physical memory (up to 64TB). The 2122 virtual address will be randomized from 16MB up to 1GB (9 bits 2123 of entropy). Note that this also reduces the memory space 2124 available to kernel modules from 1.5GB to 1GB. 2125 2126 On 32-bit, the kernel physical and virtual addresses are 2127 randomized together. They will be randomized from 16MB up to 2128 512MB (8 bits of entropy). 2129 2130 Entropy is generated using the RDRAND instruction if it is 2131 supported. If RDTSC is supported, its value is mixed into 2132 the entropy pool as well. If neither RDRAND nor RDTSC are 2133 supported, then entropy is read from the i8254 timer. The 2134 usable entropy is limited by the kernel being built using 2135 2GB addressing, and that PHYSICAL_ALIGN must be at a 2136 minimum of 2MB. As a result, only 10 bits of entropy are 2137 theoretically possible, but the implementations are further 2138 limited due to memory layouts. 2139 2140 If unsure, say Y. 2141 2142# Relocation on x86 needs some additional build support 2143config X86_NEED_RELOCS 2144 def_bool y 2145 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2146 2147config PHYSICAL_ALIGN 2148 hex "Alignment value to which kernel should be aligned" 2149 default "0x200000" 2150 range 0x2000 0x1000000 if X86_32 2151 range 0x200000 0x1000000 if X86_64 2152 ---help--- 2153 This value puts the alignment restrictions on physical address 2154 where kernel is loaded and run from. Kernel is compiled for an 2155 address which meets above alignment restriction. 2156 2157 If bootloader loads the kernel at a non-aligned address and 2158 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2159 address aligned to above value and run from there. 2160 2161 If bootloader loads the kernel at a non-aligned address and 2162 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2163 load address and decompress itself to the address it has been 2164 compiled for and run from there. The address for which kernel is 2165 compiled already meets above alignment restrictions. Hence the 2166 end result is that kernel runs from a physical address meeting 2167 above alignment restrictions. 2168 2169 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2170 this value must be a multiple of 0x200000. 2171 2172 Don't change this unless you know what you are doing. 2173 2174config DYNAMIC_MEMORY_LAYOUT 2175 bool 2176 ---help--- 2177 This option makes base addresses of vmalloc and vmemmap as well as 2178 __PAGE_OFFSET movable during boot. 2179 2180config RANDOMIZE_MEMORY 2181 bool "Randomize the kernel memory sections" 2182 depends on X86_64 2183 depends on RANDOMIZE_BASE 2184 select DYNAMIC_MEMORY_LAYOUT 2185 default RANDOMIZE_BASE 2186 ---help--- 2187 Randomizes the base virtual address of kernel memory sections 2188 (physical memory mapping, vmalloc & vmemmap). This security feature 2189 makes exploits relying on predictable memory locations less reliable. 2190 2191 The order of allocations remains unchanged. Entropy is generated in 2192 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2193 configuration have in average 30,000 different possible virtual 2194 addresses for each memory section. 2195 2196 If unsure, say Y. 2197 2198config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2199 hex "Physical memory mapping padding" if EXPERT 2200 depends on RANDOMIZE_MEMORY 2201 default "0xa" if MEMORY_HOTPLUG 2202 default "0x0" 2203 range 0x1 0x40 if MEMORY_HOTPLUG 2204 range 0x0 0x40 2205 ---help--- 2206 Define the padding in terabytes added to the existing physical 2207 memory size during kernel memory randomization. It is useful 2208 for memory hotplug support but reduces the entropy available for 2209 address randomization. 2210 2211 If unsure, leave at the default value. 2212 2213config HOTPLUG_CPU 2214 def_bool y 2215 depends on SMP 2216 2217config BOOTPARAM_HOTPLUG_CPU0 2218 bool "Set default setting of cpu0_hotpluggable" 2219 depends on HOTPLUG_CPU 2220 ---help--- 2221 Set whether default state of cpu0_hotpluggable is on or off. 2222 2223 Say Y here to enable CPU0 hotplug by default. If this switch 2224 is turned on, there is no need to give cpu0_hotplug kernel 2225 parameter and the CPU0 hotplug feature is enabled by default. 2226 2227 Please note: there are two known CPU0 dependencies if you want 2228 to enable the CPU0 hotplug feature either by this switch or by 2229 cpu0_hotplug kernel parameter. 2230 2231 First, resume from hibernate or suspend always starts from CPU0. 2232 So hibernate and suspend are prevented if CPU0 is offline. 2233 2234 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2235 offline if any interrupt can not migrate out of CPU0. There may 2236 be other CPU0 dependencies. 2237 2238 Please make sure the dependencies are under your control before 2239 you enable this feature. 2240 2241 Say N if you don't want to enable CPU0 hotplug feature by default. 2242 You still can enable the CPU0 hotplug feature at boot by kernel 2243 parameter cpu0_hotplug. 2244 2245config DEBUG_HOTPLUG_CPU0 2246 def_bool n 2247 prompt "Debug CPU0 hotplug" 2248 depends on HOTPLUG_CPU 2249 ---help--- 2250 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2251 soon as possible and boots up userspace with CPU0 offlined. User 2252 can online CPU0 back after boot time. 2253 2254 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2255 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2256 compilation or giving cpu0_hotplug kernel parameter at boot. 2257 2258 If unsure, say N. 2259 2260config COMPAT_VDSO 2261 def_bool n 2262 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2263 depends on COMPAT_32 2264 ---help--- 2265 Certain buggy versions of glibc will crash if they are 2266 presented with a 32-bit vDSO that is not mapped at the address 2267 indicated in its segment table. 2268 2269 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2270 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2271 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2272 the only released version with the bug, but OpenSUSE 9 2273 contains a buggy "glibc 2.3.2". 2274 2275 The symptom of the bug is that everything crashes on startup, saying: 2276 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2277 2278 Saying Y here changes the default value of the vdso32 boot 2279 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2280 This works around the glibc bug but hurts performance. 2281 2282 If unsure, say N: if you are compiling your own kernel, you 2283 are unlikely to be using a buggy version of glibc. 2284 2285choice 2286 prompt "vsyscall table for legacy applications" 2287 depends on X86_64 2288 default LEGACY_VSYSCALL_EMULATE 2289 help 2290 Legacy user code that does not know how to find the vDSO expects 2291 to be able to issue three syscalls by calling fixed addresses in 2292 kernel space. Since this location is not randomized with ASLR, 2293 it can be used to assist security vulnerability exploitation. 2294 2295 This setting can be changed at boot time via the kernel command 2296 line parameter vsyscall=[emulate|none]. 2297 2298 On a system with recent enough glibc (2.14 or newer) and no 2299 static binaries, you can say None without a performance penalty 2300 to improve security. 2301 2302 If unsure, select "Emulate". 2303 2304 config LEGACY_VSYSCALL_EMULATE 2305 bool "Emulate" 2306 help 2307 The kernel traps and emulates calls into the fixed 2308 vsyscall address mapping. This makes the mapping 2309 non-executable, but it still contains known contents, 2310 which could be used in certain rare security vulnerability 2311 exploits. This configuration is recommended when userspace 2312 still uses the vsyscall area. 2313 2314 config LEGACY_VSYSCALL_NONE 2315 bool "None" 2316 help 2317 There will be no vsyscall mapping at all. This will 2318 eliminate any risk of ASLR bypass due to the vsyscall 2319 fixed address mapping. Attempts to use the vsyscalls 2320 will be reported to dmesg, so that either old or 2321 malicious userspace programs can be identified. 2322 2323endchoice 2324 2325config CMDLINE_BOOL 2326 bool "Built-in kernel command line" 2327 ---help--- 2328 Allow for specifying boot arguments to the kernel at 2329 build time. On some systems (e.g. embedded ones), it is 2330 necessary or convenient to provide some or all of the 2331 kernel boot arguments with the kernel itself (that is, 2332 to not rely on the boot loader to provide them.) 2333 2334 To compile command line arguments into the kernel, 2335 set this option to 'Y', then fill in the 2336 boot arguments in CONFIG_CMDLINE. 2337 2338 Systems with fully functional boot loaders (i.e. non-embedded) 2339 should leave this option set to 'N'. 2340 2341config CMDLINE 2342 string "Built-in kernel command string" 2343 depends on CMDLINE_BOOL 2344 default "" 2345 ---help--- 2346 Enter arguments here that should be compiled into the kernel 2347 image and used at boot time. If the boot loader provides a 2348 command line at boot time, it is appended to this string to 2349 form the full kernel command line, when the system boots. 2350 2351 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2352 change this behavior. 2353 2354 In most cases, the command line (whether built-in or provided 2355 by the boot loader) should specify the device for the root 2356 file system. 2357 2358config CMDLINE_OVERRIDE 2359 bool "Built-in command line overrides boot loader arguments" 2360 depends on CMDLINE_BOOL 2361 ---help--- 2362 Set this option to 'Y' to have the kernel ignore the boot loader 2363 command line, and use ONLY the built-in command line. 2364 2365 This is used to work around broken boot loaders. This should 2366 be set to 'N' under normal conditions. 2367 2368config MODIFY_LDT_SYSCALL 2369 bool "Enable the LDT (local descriptor table)" if EXPERT 2370 default y 2371 ---help--- 2372 Linux can allow user programs to install a per-process x86 2373 Local Descriptor Table (LDT) using the modify_ldt(2) system 2374 call. This is required to run 16-bit or segmented code such as 2375 DOSEMU or some Wine programs. It is also used by some very old 2376 threading libraries. 2377 2378 Enabling this feature adds a small amount of overhead to 2379 context switches and increases the low-level kernel attack 2380 surface. Disabling it removes the modify_ldt(2) system call. 2381 2382 Saying 'N' here may make sense for embedded or server kernels. 2383 2384source "kernel/livepatch/Kconfig" 2385 2386endmenu 2387 2388config ARCH_HAS_ADD_PAGES 2389 def_bool y 2390 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2391 2392config ARCH_ENABLE_MEMORY_HOTPLUG 2393 def_bool y 2394 depends on X86_64 || (X86_32 && HIGHMEM) 2395 2396config ARCH_ENABLE_MEMORY_HOTREMOVE 2397 def_bool y 2398 depends on MEMORY_HOTPLUG 2399 2400config USE_PERCPU_NUMA_NODE_ID 2401 def_bool y 2402 depends on NUMA 2403 2404config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2405 def_bool y 2406 depends on X86_64 || X86_PAE 2407 2408config ARCH_ENABLE_HUGEPAGE_MIGRATION 2409 def_bool y 2410 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2411 2412config ARCH_ENABLE_THP_MIGRATION 2413 def_bool y 2414 depends on X86_64 && TRANSPARENT_HUGEPAGE 2415 2416menu "Power management and ACPI options" 2417 2418config ARCH_HIBERNATION_HEADER 2419 def_bool y 2420 depends on HIBERNATION 2421 2422source "kernel/power/Kconfig" 2423 2424source "drivers/acpi/Kconfig" 2425 2426source "drivers/sfi/Kconfig" 2427 2428config X86_APM_BOOT 2429 def_bool y 2430 depends on APM 2431 2432menuconfig APM 2433 tristate "APM (Advanced Power Management) BIOS support" 2434 depends on X86_32 && PM_SLEEP 2435 ---help--- 2436 APM is a BIOS specification for saving power using several different 2437 techniques. This is mostly useful for battery powered laptops with 2438 APM compliant BIOSes. If you say Y here, the system time will be 2439 reset after a RESUME operation, the /proc/apm device will provide 2440 battery status information, and user-space programs will receive 2441 notification of APM "events" (e.g. battery status change). 2442 2443 If you select "Y" here, you can disable actual use of the APM 2444 BIOS by passing the "apm=off" option to the kernel at boot time. 2445 2446 Note that the APM support is almost completely disabled for 2447 machines with more than one CPU. 2448 2449 In order to use APM, you will need supporting software. For location 2450 and more information, read <file:Documentation/power/apm-acpi.txt> 2451 and the Battery Powered Linux mini-HOWTO, available from 2452 <http://www.tldp.org/docs.html#howto>. 2453 2454 This driver does not spin down disk drives (see the hdparm(8) 2455 manpage ("man 8 hdparm") for that), and it doesn't turn off 2456 VESA-compliant "green" monitors. 2457 2458 This driver does not support the TI 4000M TravelMate and the ACER 2459 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2460 desktop machines also don't have compliant BIOSes, and this driver 2461 may cause those machines to panic during the boot phase. 2462 2463 Generally, if you don't have a battery in your machine, there isn't 2464 much point in using this driver and you should say N. If you get 2465 random kernel OOPSes or reboots that don't seem to be related to 2466 anything, try disabling/enabling this option (or disabling/enabling 2467 APM in your BIOS). 2468 2469 Some other things you should try when experiencing seemingly random, 2470 "weird" problems: 2471 2472 1) make sure that you have enough swap space and that it is 2473 enabled. 2474 2) pass the "no-hlt" option to the kernel 2475 3) switch on floating point emulation in the kernel and pass 2476 the "no387" option to the kernel 2477 4) pass the "floppy=nodma" option to the kernel 2478 5) pass the "mem=4M" option to the kernel (thereby disabling 2479 all but the first 4 MB of RAM) 2480 6) make sure that the CPU is not over clocked. 2481 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2482 8) disable the cache from your BIOS settings 2483 9) install a fan for the video card or exchange video RAM 2484 10) install a better fan for the CPU 2485 11) exchange RAM chips 2486 12) exchange the motherboard. 2487 2488 To compile this driver as a module, choose M here: the 2489 module will be called apm. 2490 2491if APM 2492 2493config APM_IGNORE_USER_SUSPEND 2494 bool "Ignore USER SUSPEND" 2495 ---help--- 2496 This option will ignore USER SUSPEND requests. On machines with a 2497 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2498 series notebooks, it is necessary to say Y because of a BIOS bug. 2499 2500config APM_DO_ENABLE 2501 bool "Enable PM at boot time" 2502 ---help--- 2503 Enable APM features at boot time. From page 36 of the APM BIOS 2504 specification: "When disabled, the APM BIOS does not automatically 2505 power manage devices, enter the Standby State, enter the Suspend 2506 State, or take power saving steps in response to CPU Idle calls." 2507 This driver will make CPU Idle calls when Linux is idle (unless this 2508 feature is turned off -- see "Do CPU IDLE calls", below). This 2509 should always save battery power, but more complicated APM features 2510 will be dependent on your BIOS implementation. You may need to turn 2511 this option off if your computer hangs at boot time when using APM 2512 support, or if it beeps continuously instead of suspending. Turn 2513 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2514 T400CDT. This is off by default since most machines do fine without 2515 this feature. 2516 2517config APM_CPU_IDLE 2518 depends on CPU_IDLE 2519 bool "Make CPU Idle calls when idle" 2520 ---help--- 2521 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2522 On some machines, this can activate improved power savings, such as 2523 a slowed CPU clock rate, when the machine is idle. These idle calls 2524 are made after the idle loop has run for some length of time (e.g., 2525 333 mS). On some machines, this will cause a hang at boot time or 2526 whenever the CPU becomes idle. (On machines with more than one CPU, 2527 this option does nothing.) 2528 2529config APM_DISPLAY_BLANK 2530 bool "Enable console blanking using APM" 2531 ---help--- 2532 Enable console blanking using the APM. Some laptops can use this to 2533 turn off the LCD backlight when the screen blanker of the Linux 2534 virtual console blanks the screen. Note that this is only used by 2535 the virtual console screen blanker, and won't turn off the backlight 2536 when using the X Window system. This also doesn't have anything to 2537 do with your VESA-compliant power-saving monitor. Further, this 2538 option doesn't work for all laptops -- it might not turn off your 2539 backlight at all, or it might print a lot of errors to the console, 2540 especially if you are using gpm. 2541 2542config APM_ALLOW_INTS 2543 bool "Allow interrupts during APM BIOS calls" 2544 ---help--- 2545 Normally we disable external interrupts while we are making calls to 2546 the APM BIOS as a measure to lessen the effects of a badly behaving 2547 BIOS implementation. The BIOS should reenable interrupts if it 2548 needs to. Unfortunately, some BIOSes do not -- especially those in 2549 many of the newer IBM Thinkpads. If you experience hangs when you 2550 suspend, try setting this to Y. Otherwise, say N. 2551 2552endif # APM 2553 2554source "drivers/cpufreq/Kconfig" 2555 2556source "drivers/cpuidle/Kconfig" 2557 2558source "drivers/idle/Kconfig" 2559 2560endmenu 2561 2562 2563menu "Bus options (PCI etc.)" 2564 2565choice 2566 prompt "PCI access mode" 2567 depends on X86_32 && PCI 2568 default PCI_GOANY 2569 ---help--- 2570 On PCI systems, the BIOS can be used to detect the PCI devices and 2571 determine their configuration. However, some old PCI motherboards 2572 have BIOS bugs and may crash if this is done. Also, some embedded 2573 PCI-based systems don't have any BIOS at all. Linux can also try to 2574 detect the PCI hardware directly without using the BIOS. 2575 2576 With this option, you can specify how Linux should detect the 2577 PCI devices. If you choose "BIOS", the BIOS will be used, 2578 if you choose "Direct", the BIOS won't be used, and if you 2579 choose "MMConfig", then PCI Express MMCONFIG will be used. 2580 If you choose "Any", the kernel will try MMCONFIG, then the 2581 direct access method and falls back to the BIOS if that doesn't 2582 work. If unsure, go with the default, which is "Any". 2583 2584config PCI_GOBIOS 2585 bool "BIOS" 2586 2587config PCI_GOMMCONFIG 2588 bool "MMConfig" 2589 2590config PCI_GODIRECT 2591 bool "Direct" 2592 2593config PCI_GOOLPC 2594 bool "OLPC XO-1" 2595 depends on OLPC 2596 2597config PCI_GOANY 2598 bool "Any" 2599 2600endchoice 2601 2602config PCI_BIOS 2603 def_bool y 2604 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2605 2606# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2607config PCI_DIRECT 2608 def_bool y 2609 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2610 2611config PCI_MMCONFIG 2612 bool "Support mmconfig PCI config space access" if X86_64 2613 default y 2614 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2615 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2616 2617config PCI_OLPC 2618 def_bool y 2619 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2620 2621config PCI_XEN 2622 def_bool y 2623 depends on PCI && XEN 2624 select SWIOTLB_XEN 2625 2626config MMCONF_FAM10H 2627 def_bool y 2628 depends on X86_64 && PCI_MMCONFIG && ACPI 2629 2630config PCI_CNB20LE_QUIRK 2631 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2632 depends on PCI 2633 help 2634 Read the PCI windows out of the CNB20LE host bridge. This allows 2635 PCI hotplug to work on systems with the CNB20LE chipset which do 2636 not have ACPI. 2637 2638 There's no public spec for this chipset, and this functionality 2639 is known to be incomplete. 2640 2641 You should say N unless you know you need this. 2642 2643config ISA_BUS 2644 bool "ISA bus support on modern systems" if EXPERT 2645 help 2646 Expose ISA bus device drivers and options available for selection and 2647 configuration. Enable this option if your target machine has an ISA 2648 bus. ISA is an older system, displaced by PCI and newer bus 2649 architectures -- if your target machine is modern, it probably does 2650 not have an ISA bus. 2651 2652 If unsure, say N. 2653 2654# x86_64 have no ISA slots, but can have ISA-style DMA. 2655config ISA_DMA_API 2656 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2657 default y 2658 help 2659 Enables ISA-style DMA support for devices requiring such controllers. 2660 If unsure, say Y. 2661 2662if X86_32 2663 2664config ISA 2665 bool "ISA support" 2666 ---help--- 2667 Find out whether you have ISA slots on your motherboard. ISA is the 2668 name of a bus system, i.e. the way the CPU talks to the other stuff 2669 inside your box. Other bus systems are PCI, EISA, MicroChannel 2670 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2671 newer boards don't support it. If you have ISA, say Y, otherwise N. 2672 2673config SCx200 2674 tristate "NatSemi SCx200 support" 2675 ---help--- 2676 This provides basic support for National Semiconductor's 2677 (now AMD's) Geode processors. The driver probes for the 2678 PCI-IDs of several on-chip devices, so its a good dependency 2679 for other scx200_* drivers. 2680 2681 If compiled as a module, the driver is named scx200. 2682 2683config SCx200HR_TIMER 2684 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2685 depends on SCx200 2686 default y 2687 ---help--- 2688 This driver provides a clocksource built upon the on-chip 2689 27MHz high-resolution timer. Its also a workaround for 2690 NSC Geode SC-1100's buggy TSC, which loses time when the 2691 processor goes idle (as is done by the scheduler). The 2692 other workaround is idle=poll boot option. 2693 2694config OLPC 2695 bool "One Laptop Per Child support" 2696 depends on !X86_PAE 2697 select GPIOLIB 2698 select OF 2699 select OF_PROMTREE 2700 select IRQ_DOMAIN 2701 select OLPC_EC 2702 ---help--- 2703 Add support for detecting the unique features of the OLPC 2704 XO hardware. 2705 2706config OLPC_XO1_PM 2707 bool "OLPC XO-1 Power Management" 2708 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2709 ---help--- 2710 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2711 2712config OLPC_XO1_RTC 2713 bool "OLPC XO-1 Real Time Clock" 2714 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2715 ---help--- 2716 Add support for the XO-1 real time clock, which can be used as a 2717 programmable wakeup source. 2718 2719config OLPC_XO1_SCI 2720 bool "OLPC XO-1 SCI extras" 2721 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2722 depends on INPUT=y 2723 select POWER_SUPPLY 2724 ---help--- 2725 Add support for SCI-based features of the OLPC XO-1 laptop: 2726 - EC-driven system wakeups 2727 - Power button 2728 - Ebook switch 2729 - Lid switch 2730 - AC adapter status updates 2731 - Battery status updates 2732 2733config OLPC_XO15_SCI 2734 bool "OLPC XO-1.5 SCI extras" 2735 depends on OLPC && ACPI 2736 select POWER_SUPPLY 2737 ---help--- 2738 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2739 - EC-driven system wakeups 2740 - AC adapter status updates 2741 - Battery status updates 2742 2743config ALIX 2744 bool "PCEngines ALIX System Support (LED setup)" 2745 select GPIOLIB 2746 ---help--- 2747 This option enables system support for the PCEngines ALIX. 2748 At present this just sets up LEDs for GPIO control on 2749 ALIX2/3/6 boards. However, other system specific setup should 2750 get added here. 2751 2752 Note: You must still enable the drivers for GPIO and LED support 2753 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2754 2755 Note: You have to set alix.force=1 for boards with Award BIOS. 2756 2757config NET5501 2758 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2759 select GPIOLIB 2760 ---help--- 2761 This option enables system support for the Soekris Engineering net5501. 2762 2763config GEOS 2764 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2765 select GPIOLIB 2766 depends on DMI 2767 ---help--- 2768 This option enables system support for the Traverse Technologies GEOS. 2769 2770config TS5500 2771 bool "Technologic Systems TS-5500 platform support" 2772 depends on MELAN 2773 select CHECK_SIGNATURE 2774 select NEW_LEDS 2775 select LEDS_CLASS 2776 ---help--- 2777 This option enables system support for the Technologic Systems TS-5500. 2778 2779endif # X86_32 2780 2781config AMD_NB 2782 def_bool y 2783 depends on CPU_SUP_AMD && PCI 2784 2785config X86_SYSFB 2786 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2787 help 2788 Firmwares often provide initial graphics framebuffers so the BIOS, 2789 bootloader or kernel can show basic video-output during boot for 2790 user-guidance and debugging. Historically, x86 used the VESA BIOS 2791 Extensions and EFI-framebuffers for this, which are mostly limited 2792 to x86. 2793 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2794 framebuffers so the new generic system-framebuffer drivers can be 2795 used on x86. If the framebuffer is not compatible with the generic 2796 modes, it is advertised as fallback platform framebuffer so legacy 2797 drivers like efifb, vesafb and uvesafb can pick it up. 2798 If this option is not selected, all system framebuffers are always 2799 marked as fallback platform framebuffers as usual. 2800 2801 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2802 not be able to pick up generic system framebuffers if this option 2803 is selected. You are highly encouraged to enable simplefb as 2804 replacement if you select this option. simplefb can correctly deal 2805 with generic system framebuffers. But you should still keep vesafb 2806 and others enabled as fallback if a system framebuffer is 2807 incompatible with simplefb. 2808 2809 If unsure, say Y. 2810 2811endmenu 2812 2813 2814menu "Binary Emulations" 2815 2816config IA32_EMULATION 2817 bool "IA32 Emulation" 2818 depends on X86_64 2819 select ARCH_WANT_OLD_COMPAT_IPC 2820 select BINFMT_ELF 2821 select COMPAT_BINFMT_ELF 2822 select COMPAT_OLD_SIGACTION 2823 ---help--- 2824 Include code to run legacy 32-bit programs under a 2825 64-bit kernel. You should likely turn this on, unless you're 2826 100% sure that you don't have any 32-bit programs left. 2827 2828config IA32_AOUT 2829 tristate "IA32 a.out support" 2830 depends on IA32_EMULATION 2831 depends on BROKEN 2832 ---help--- 2833 Support old a.out binaries in the 32bit emulation. 2834 2835config X86_X32 2836 bool "x32 ABI for 64-bit mode" 2837 depends on X86_64 2838 ---help--- 2839 Include code to run binaries for the x32 native 32-bit ABI 2840 for 64-bit processors. An x32 process gets access to the 2841 full 64-bit register file and wide data path while leaving 2842 pointers at 32 bits for smaller memory footprint. 2843 2844 You will need a recent binutils (2.22 or later) with 2845 elf32_x86_64 support enabled to compile a kernel with this 2846 option set. 2847 2848config COMPAT_32 2849 def_bool y 2850 depends on IA32_EMULATION || X86_32 2851 select HAVE_UID16 2852 select OLD_SIGSUSPEND3 2853 2854config COMPAT 2855 def_bool y 2856 depends on IA32_EMULATION || X86_X32 2857 2858if COMPAT 2859config COMPAT_FOR_U64_ALIGNMENT 2860 def_bool y 2861 2862config SYSVIPC_COMPAT 2863 def_bool y 2864 depends on SYSVIPC 2865endif 2866 2867endmenu 2868 2869 2870config HAVE_ATOMIC_IOMAP 2871 def_bool y 2872 depends on X86_32 2873 2874config X86_DEV_DMA_OPS 2875 bool 2876 2877config HAVE_GENERIC_GUP 2878 def_bool y 2879 2880source "drivers/firmware/Kconfig" 2881 2882source "arch/x86/kvm/Kconfig" 2883