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