1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if ARCH = "x86" 5 default ARCH != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_AOUT 18 select HAVE_GENERIC_DMA_COHERENT 19 select MODULES_USE_ELF_REL 20 select OLD_SIGACTION 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select X86_DEV_DMA_OPS 32 33# 34# Arch settings 35# 36# ( Note that options that are marked 'if X86_64' could in principle be 37# ported to 32-bit as well. ) 38# 39config X86 40 def_bool y 41 # 42 # Note: keep this list sorted alphabetically 43 # 44 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 45 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 46 select ANON_INODES 47 select ARCH_CLOCKSOURCE_DATA 48 select ARCH_DISCARD_MEMBLOCK 49 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 50 select ARCH_HAS_DEBUG_VIRTUAL 51 select ARCH_HAS_DEVMEM_IS_ALLOWED 52 select ARCH_HAS_ELF_RANDOMIZE 53 select ARCH_HAS_FAST_MULTIPLIER 54 select ARCH_HAS_FORTIFY_SOURCE 55 select ARCH_HAS_GCOV_PROFILE_ALL 56 select ARCH_HAS_KCOV if X86_64 57 select ARCH_HAS_PMEM_API if X86_64 58 # Causing hangs/crashes, see the commit that added this change for details. 59 select ARCH_HAS_REFCOUNT 60 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 61 select ARCH_HAS_SET_MEMORY 62 select ARCH_HAS_SG_CHAIN 63 select ARCH_HAS_STRICT_KERNEL_RWX 64 select ARCH_HAS_STRICT_MODULE_RWX 65 select ARCH_HAS_UBSAN_SANITIZE_ALL 66 select ARCH_HAS_ZONE_DEVICE if X86_64 67 select ARCH_HAVE_NMI_SAFE_CMPXCHG 68 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 69 select ARCH_MIGHT_HAVE_PC_PARPORT 70 select ARCH_MIGHT_HAVE_PC_SERIO 71 select ARCH_SUPPORTS_ATOMIC_RMW 72 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 73 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 74 select ARCH_USE_BUILTIN_BSWAP 75 select ARCH_USE_QUEUED_RWLOCKS 76 select ARCH_USE_QUEUED_SPINLOCKS 77 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 78 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 79 select ARCH_WANTS_THP_SWAP if X86_64 80 select BUILDTIME_EXTABLE_SORT 81 select CLKEVT_I8253 82 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 83 select CLOCKSOURCE_WATCHDOG 84 select DCACHE_WORD_ACCESS 85 select EDAC_ATOMIC_SCRUB 86 select EDAC_SUPPORT 87 select GENERIC_CLOCKEVENTS 88 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 89 select GENERIC_CLOCKEVENTS_MIN_ADJUST 90 select GENERIC_CMOS_UPDATE 91 select GENERIC_CPU_AUTOPROBE 92 select GENERIC_CPU_VULNERABILITIES 93 select GENERIC_EARLY_IOREMAP 94 select GENERIC_FIND_FIRST_BIT 95 select GENERIC_IOMAP 96 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 97 select GENERIC_IRQ_MIGRATION if SMP 98 select GENERIC_IRQ_PROBE 99 select GENERIC_IRQ_SHOW 100 select GENERIC_PENDING_IRQ if SMP 101 select GENERIC_SMP_IDLE_THREAD 102 select GENERIC_STRNCPY_FROM_USER 103 select GENERIC_STRNLEN_USER 104 select GENERIC_TIME_VSYSCALL 105 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 106 select HAVE_ACPI_APEI if ACPI 107 select HAVE_ACPI_APEI_NMI if ACPI 108 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 109 select HAVE_ARCH_AUDITSYSCALL 110 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 111 select HAVE_ARCH_JUMP_LABEL 112 select HAVE_ARCH_KASAN if X86_64 113 select HAVE_ARCH_KGDB 114 select HAVE_ARCH_MMAP_RND_BITS if MMU 115 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 116 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 117 select HAVE_ARCH_SECCOMP_FILTER 118 select HAVE_ARCH_TRACEHOOK 119 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 120 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 121 select HAVE_ARCH_VMAP_STACK if X86_64 122 select HAVE_ARCH_WITHIN_STACK_FRAMES 123 select HAVE_CC_STACKPROTECTOR 124 select HAVE_CMPXCHG_DOUBLE 125 select HAVE_CMPXCHG_LOCAL 126 select HAVE_CONTEXT_TRACKING if X86_64 127 select HAVE_COPY_THREAD_TLS 128 select HAVE_C_RECORDMCOUNT 129 select HAVE_DEBUG_KMEMLEAK 130 select HAVE_DEBUG_STACKOVERFLOW 131 select HAVE_DMA_API_DEBUG 132 select HAVE_DMA_CONTIGUOUS 133 select HAVE_DYNAMIC_FTRACE 134 select HAVE_DYNAMIC_FTRACE_WITH_REGS 135 select HAVE_EBPF_JIT if X86_64 136 select HAVE_EFFICIENT_UNALIGNED_ACCESS 137 select HAVE_EXIT_THREAD 138 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 139 select HAVE_FTRACE_MCOUNT_RECORD 140 select HAVE_FUNCTION_GRAPH_TRACER 141 select HAVE_FUNCTION_TRACER 142 select HAVE_GCC_PLUGINS 143 select HAVE_HW_BREAKPOINT 144 select HAVE_IDE 145 select HAVE_IOREMAP_PROT 146 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 147 select HAVE_IRQ_TIME_ACCOUNTING 148 select HAVE_KERNEL_BZIP2 149 select HAVE_KERNEL_GZIP 150 select HAVE_KERNEL_LZ4 151 select HAVE_KERNEL_LZMA 152 select HAVE_KERNEL_LZO 153 select HAVE_KERNEL_XZ 154 select HAVE_KPROBES 155 select HAVE_KPROBES_ON_FTRACE 156 select HAVE_KRETPROBES 157 select HAVE_KVM 158 select HAVE_LIVEPATCH if X86_64 159 select HAVE_MEMBLOCK 160 select HAVE_MEMBLOCK_NODE_MAP 161 select HAVE_MIXED_BREAKPOINTS_REGS 162 select HAVE_MOD_ARCH_SPECIFIC 163 select HAVE_NMI 164 select HAVE_OPROFILE 165 select HAVE_OPTPROBES 166 select HAVE_PCSPKR_PLATFORM 167 select HAVE_PERF_EVENTS 168 select HAVE_PERF_EVENTS_NMI 169 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 170 select HAVE_PERF_REGS 171 select HAVE_PERF_USER_STACK_DUMP 172 select HAVE_RCU_TABLE_FREE 173 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 174 select HAVE_REGS_AND_STACK_ACCESS_API 175 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 176 select HAVE_STACK_VALIDATION if X86_64 177 select HAVE_SYSCALL_TRACEPOINTS 178 select HAVE_UNSTABLE_SCHED_CLOCK 179 select HAVE_USER_RETURN_NOTIFIER 180 select HOTPLUG_SMT if SMP 181 select IRQ_FORCED_THREADING 182 select PCI_LOCKLESS_CONFIG 183 select PERF_EVENTS 184 select RTC_LIB 185 select RTC_MC146818_LIB 186 select SPARSE_IRQ 187 select SRCU 188 select SYSCTL_EXCEPTION_TRACE 189 select THREAD_INFO_IN_TASK 190 select USER_STACKTRACE_SUPPORT 191 select VIRT_TO_BUS 192 select X86_FEATURE_NAMES if PROC_FS 193 194config INSTRUCTION_DECODER 195 def_bool y 196 depends on KPROBES || PERF_EVENTS || UPROBES 197 198config OUTPUT_FORMAT 199 string 200 default "elf32-i386" if X86_32 201 default "elf64-x86-64" if X86_64 202 203config ARCH_DEFCONFIG 204 string 205 default "arch/x86/configs/i386_defconfig" if X86_32 206 default "arch/x86/configs/x86_64_defconfig" if X86_64 207 208config LOCKDEP_SUPPORT 209 def_bool y 210 211config STACKTRACE_SUPPORT 212 def_bool y 213 214config MMU 215 def_bool y 216 217config ARCH_MMAP_RND_BITS_MIN 218 default 28 if 64BIT 219 default 8 220 221config ARCH_MMAP_RND_BITS_MAX 222 default 32 if 64BIT 223 default 16 224 225config ARCH_MMAP_RND_COMPAT_BITS_MIN 226 default 8 227 228config ARCH_MMAP_RND_COMPAT_BITS_MAX 229 default 16 230 231config SBUS 232 bool 233 234config NEED_DMA_MAP_STATE 235 def_bool y 236 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 237 238config NEED_SG_DMA_LENGTH 239 def_bool y 240 241config GENERIC_ISA_DMA 242 def_bool y 243 depends on ISA_DMA_API 244 245config GENERIC_BUG 246 def_bool y 247 depends on BUG 248 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 249 250config GENERIC_BUG_RELATIVE_POINTERS 251 bool 252 253config GENERIC_HWEIGHT 254 def_bool y 255 256config ARCH_MAY_HAVE_PC_FDC 257 def_bool y 258 depends on ISA_DMA_API 259 260config RWSEM_XCHGADD_ALGORITHM 261 def_bool y 262 263config GENERIC_CALIBRATE_DELAY 264 def_bool y 265 266config ARCH_HAS_CPU_RELAX 267 def_bool y 268 269config ARCH_HAS_CACHE_LINE_SIZE 270 def_bool y 271 272config HAVE_SETUP_PER_CPU_AREA 273 def_bool y 274 275config NEED_PER_CPU_EMBED_FIRST_CHUNK 276 def_bool y 277 278config NEED_PER_CPU_PAGE_FIRST_CHUNK 279 def_bool y 280 281config ARCH_HIBERNATION_POSSIBLE 282 def_bool y 283 284config ARCH_SUSPEND_POSSIBLE 285 def_bool y 286 287config ARCH_WANT_HUGE_PMD_SHARE 288 def_bool y 289 290config ARCH_WANT_GENERAL_HUGETLB 291 def_bool y 292 293config ZONE_DMA32 294 def_bool y if X86_64 295 296config AUDIT_ARCH 297 def_bool y if X86_64 298 299config ARCH_SUPPORTS_OPTIMIZED_INLINING 300 def_bool y 301 302config ARCH_SUPPORTS_DEBUG_PAGEALLOC 303 def_bool y 304 305config KASAN_SHADOW_OFFSET 306 hex 307 depends on KASAN 308 default 0xdffffc0000000000 309 310config HAVE_INTEL_TXT 311 def_bool y 312 depends on INTEL_IOMMU && ACPI 313 314config X86_32_SMP 315 def_bool y 316 depends on X86_32 && SMP 317 318config X86_64_SMP 319 def_bool y 320 depends on X86_64 && SMP 321 322config X86_32_LAZY_GS 323 def_bool y 324 depends on X86_32 && !CC_STACKPROTECTOR 325 326config ARCH_SUPPORTS_UPROBES 327 def_bool y 328 329config FIX_EARLYCON_MEM 330 def_bool y 331 332config PGTABLE_LEVELS 333 int 334 default 5 if X86_5LEVEL 335 default 4 if X86_64 336 default 3 if X86_PAE 337 default 2 338 339source "init/Kconfig" 340source "kernel/Kconfig.freezer" 341 342menu "Processor type and features" 343 344config ZONE_DMA 345 bool "DMA memory allocation support" if EXPERT 346 default y 347 help 348 DMA memory allocation support allows devices with less than 32-bit 349 addressing to allocate within the first 16MB of address space. 350 Disable if no such devices will be used. 351 352 If unsure, say Y. 353 354config SMP 355 bool "Symmetric multi-processing support" 356 ---help--- 357 This enables support for systems with more than one CPU. If you have 358 a system with only one CPU, say N. If you have a system with more 359 than one CPU, say Y. 360 361 If you say N here, the kernel will run on uni- and multiprocessor 362 machines, but will use only one CPU of a multiprocessor machine. If 363 you say Y here, the kernel will run on many, but not all, 364 uniprocessor machines. On a uniprocessor machine, the kernel 365 will run faster if you say N here. 366 367 Note that if you say Y here and choose architecture "586" or 368 "Pentium" under "Processor family", the kernel will not work on 486 369 architectures. Similarly, multiprocessor kernels for the "PPro" 370 architecture may not work on all Pentium based boards. 371 372 People using multiprocessor machines who say Y here should also say 373 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 374 Management" code will be disabled if you say Y here. 375 376 See also <file:Documentation/x86/i386/IO-APIC.txt>, 377 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 378 <http://www.tldp.org/docs.html#howto>. 379 380 If you don't know what to do here, say N. 381 382config X86_FEATURE_NAMES 383 bool "Processor feature human-readable names" if EMBEDDED 384 default y 385 ---help--- 386 This option compiles in a table of x86 feature bits and corresponding 387 names. This is required to support /proc/cpuinfo and a few kernel 388 messages. You can disable this to save space, at the expense of 389 making those few kernel messages show numeric feature bits instead. 390 391 If in doubt, say Y. 392 393config X86_FAST_FEATURE_TESTS 394 bool "Fast CPU feature tests" if EMBEDDED 395 default y 396 ---help--- 397 Some fast-paths in the kernel depend on the capabilities of the CPU. 398 Say Y here for the kernel to patch in the appropriate code at runtime 399 based on the capabilities of the CPU. The infrastructure for patching 400 code at runtime takes up some additional space; space-constrained 401 embedded systems may wish to say N here to produce smaller, slightly 402 slower code. 403 404config X86_X2APIC 405 bool "Support x2apic" 406 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 407 ---help--- 408 This enables x2apic support on CPUs that have this feature. 409 410 This allows 32-bit apic IDs (so it can support very large systems), 411 and accesses the local apic via MSRs not via mmio. 412 413 If you don't know what to do here, say N. 414 415config X86_MPPARSE 416 bool "Enable MPS table" if ACPI || SFI 417 default y 418 depends on X86_LOCAL_APIC 419 ---help--- 420 For old smp systems that do not have proper acpi support. Newer systems 421 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 422 423config X86_BIGSMP 424 bool "Support for big SMP systems with more than 8 CPUs" 425 depends on X86_32 && SMP 426 ---help--- 427 This option is needed for the systems that have more than 8 CPUs 428 429config GOLDFISH 430 def_bool y 431 depends on X86_GOLDFISH 432 433config RETPOLINE 434 bool "Avoid speculative indirect branches in kernel" 435 default y 436 select STACK_VALIDATION if HAVE_STACK_VALIDATION 437 help 438 Compile kernel with the retpoline compiler options to guard against 439 kernel-to-user data leaks by avoiding speculative indirect 440 branches. Requires a compiler with -mindirect-branch=thunk-extern 441 support for full protection. The kernel may run slower. 442 443config INTEL_RDT 444 bool "Intel Resource Director Technology support" 445 default n 446 depends on X86 && CPU_SUP_INTEL 447 select KERNFS 448 help 449 Select to enable resource allocation and monitoring which are 450 sub-features of Intel Resource Director Technology(RDT). More 451 information about RDT can be found in the Intel x86 452 Architecture Software Developer Manual. 453 454 Say N if unsure. 455 456if X86_32 457config X86_EXTENDED_PLATFORM 458 bool "Support for extended (non-PC) x86 platforms" 459 default y 460 ---help--- 461 If you disable this option then the kernel will only support 462 standard PC platforms. (which covers the vast majority of 463 systems out there.) 464 465 If you enable this option then you'll be able to select support 466 for the following (non-PC) 32 bit x86 platforms: 467 Goldfish (Android emulator) 468 AMD Elan 469 RDC R-321x SoC 470 SGI 320/540 (Visual Workstation) 471 STA2X11-based (e.g. Northville) 472 Moorestown MID devices 473 474 If you have one of these systems, or if you want to build a 475 generic distribution kernel, say Y here - otherwise say N. 476endif 477 478if X86_64 479config X86_EXTENDED_PLATFORM 480 bool "Support for extended (non-PC) x86 platforms" 481 default y 482 ---help--- 483 If you disable this option then the kernel will only support 484 standard PC platforms. (which covers the vast majority of 485 systems out there.) 486 487 If you enable this option then you'll be able to select support 488 for the following (non-PC) 64 bit x86 platforms: 489 Numascale NumaChip 490 ScaleMP vSMP 491 SGI Ultraviolet 492 493 If you have one of these systems, or if you want to build a 494 generic distribution kernel, say Y here - otherwise say N. 495endif 496# This is an alphabetically sorted list of 64 bit extended platforms 497# Please maintain the alphabetic order if and when there are additions 498config X86_NUMACHIP 499 bool "Numascale NumaChip" 500 depends on X86_64 501 depends on X86_EXTENDED_PLATFORM 502 depends on NUMA 503 depends on SMP 504 depends on X86_X2APIC 505 depends on PCI_MMCONFIG 506 ---help--- 507 Adds support for Numascale NumaChip large-SMP systems. Needed to 508 enable more than ~168 cores. 509 If you don't have one of these, you should say N here. 510 511config X86_VSMP 512 bool "ScaleMP vSMP" 513 select HYPERVISOR_GUEST 514 select PARAVIRT 515 depends on X86_64 && PCI 516 depends on X86_EXTENDED_PLATFORM 517 depends on SMP 518 ---help--- 519 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 520 supposed to run on these EM64T-based machines. Only choose this option 521 if you have one of these machines. 522 523config X86_UV 524 bool "SGI Ultraviolet" 525 depends on X86_64 526 depends on X86_EXTENDED_PLATFORM 527 depends on NUMA 528 depends on EFI 529 depends on X86_X2APIC 530 depends on PCI 531 ---help--- 532 This option is needed in order to support SGI Ultraviolet systems. 533 If you don't have one of these, you should say N here. 534 535# Following is an alphabetically sorted list of 32 bit extended platforms 536# Please maintain the alphabetic order if and when there are additions 537 538config X86_GOLDFISH 539 bool "Goldfish (Virtual Platform)" 540 depends on X86_EXTENDED_PLATFORM 541 ---help--- 542 Enable support for the Goldfish virtual platform used primarily 543 for Android development. Unless you are building for the Android 544 Goldfish emulator say N here. 545 546config X86_INTEL_CE 547 bool "CE4100 TV platform" 548 depends on PCI 549 depends on PCI_GODIRECT 550 depends on X86_IO_APIC 551 depends on X86_32 552 depends on X86_EXTENDED_PLATFORM 553 select X86_REBOOTFIXUPS 554 select OF 555 select OF_EARLY_FLATTREE 556 ---help--- 557 Select for the Intel CE media processor (CE4100) SOC. 558 This option compiles in support for the CE4100 SOC for settop 559 boxes and media devices. 560 561config X86_INTEL_MID 562 bool "Intel MID platform support" 563 depends on X86_EXTENDED_PLATFORM 564 depends on X86_PLATFORM_DEVICES 565 depends on PCI 566 depends on X86_64 || (PCI_GOANY && X86_32) 567 depends on X86_IO_APIC 568 select SFI 569 select I2C 570 select DW_APB_TIMER 571 select APB_TIMER 572 select INTEL_SCU_IPC 573 select MFD_INTEL_MSIC 574 ---help--- 575 Select to build a kernel capable of supporting Intel MID (Mobile 576 Internet Device) platform systems which do not have the PCI legacy 577 interfaces. If you are building for a PC class system say N here. 578 579 Intel MID platforms are based on an Intel processor and chipset which 580 consume less power than most of the x86 derivatives. 581 582config X86_INTEL_QUARK 583 bool "Intel Quark platform support" 584 depends on X86_32 585 depends on X86_EXTENDED_PLATFORM 586 depends on X86_PLATFORM_DEVICES 587 depends on X86_TSC 588 depends on PCI 589 depends on PCI_GOANY 590 depends on X86_IO_APIC 591 select IOSF_MBI 592 select INTEL_IMR 593 select COMMON_CLK 594 ---help--- 595 Select to include support for Quark X1000 SoC. 596 Say Y here if you have a Quark based system such as the Arduino 597 compatible Intel Galileo. 598 599config X86_INTEL_LPSS 600 bool "Intel Low Power Subsystem Support" 601 depends on X86 && ACPI 602 select COMMON_CLK 603 select PINCTRL 604 select IOSF_MBI 605 ---help--- 606 Select to build support for Intel Low Power Subsystem such as 607 found on Intel Lynxpoint PCH. Selecting this option enables 608 things like clock tree (common clock framework) and pincontrol 609 which are needed by the LPSS peripheral drivers. 610 611config X86_AMD_PLATFORM_DEVICE 612 bool "AMD ACPI2Platform devices support" 613 depends on ACPI 614 select COMMON_CLK 615 select PINCTRL 616 ---help--- 617 Select to interpret AMD specific ACPI device to platform device 618 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 619 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 620 implemented under PINCTRL subsystem. 621 622config IOSF_MBI 623 tristate "Intel SoC IOSF Sideband support for SoC platforms" 624 depends on PCI 625 ---help--- 626 This option enables sideband register access support for Intel SoC 627 platforms. On these platforms the IOSF sideband is used in lieu of 628 MSR's for some register accesses, mostly but not limited to thermal 629 and power. Drivers may query the availability of this device to 630 determine if they need the sideband in order to work on these 631 platforms. The sideband is available on the following SoC products. 632 This list is not meant to be exclusive. 633 - BayTrail 634 - Braswell 635 - Quark 636 637 You should say Y if you are running a kernel on one of these SoC's. 638 639config IOSF_MBI_DEBUG 640 bool "Enable IOSF sideband access through debugfs" 641 depends on IOSF_MBI && DEBUG_FS 642 ---help--- 643 Select this option to expose the IOSF sideband access registers (MCR, 644 MDR, MCRX) through debugfs to write and read register information from 645 different units on the SoC. This is most useful for obtaining device 646 state information for debug and analysis. As this is a general access 647 mechanism, users of this option would have specific knowledge of the 648 device they want to access. 649 650 If you don't require the option or are in doubt, say N. 651 652config X86_RDC321X 653 bool "RDC R-321x SoC" 654 depends on X86_32 655 depends on X86_EXTENDED_PLATFORM 656 select M486 657 select X86_REBOOTFIXUPS 658 ---help--- 659 This option is needed for RDC R-321x system-on-chip, also known 660 as R-8610-(G). 661 If you don't have one of these chips, you should say N here. 662 663config X86_32_NON_STANDARD 664 bool "Support non-standard 32-bit SMP architectures" 665 depends on X86_32 && SMP 666 depends on X86_EXTENDED_PLATFORM 667 ---help--- 668 This option compiles in the bigsmp and STA2X11 default 669 subarchitectures. It is intended for a generic binary 670 kernel. If you select them all, kernel will probe it one by 671 one and will fallback to default. 672 673# Alphabetically sorted list of Non standard 32 bit platforms 674 675config X86_SUPPORTS_MEMORY_FAILURE 676 def_bool y 677 # MCE code calls memory_failure(): 678 depends on X86_MCE 679 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 680 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 681 depends on X86_64 || !SPARSEMEM 682 select ARCH_SUPPORTS_MEMORY_FAILURE 683 684config STA2X11 685 bool "STA2X11 Companion Chip Support" 686 depends on X86_32_NON_STANDARD && PCI 687 select X86_DEV_DMA_OPS 688 select X86_DMA_REMAP 689 select SWIOTLB 690 select MFD_STA2X11 691 select GPIOLIB 692 default n 693 ---help--- 694 This adds support for boards based on the STA2X11 IO-Hub, 695 a.k.a. "ConneXt". The chip is used in place of the standard 696 PC chipset, so all "standard" peripherals are missing. If this 697 option is selected the kernel will still be able to boot on 698 standard PC machines. 699 700config X86_32_IRIS 701 tristate "Eurobraille/Iris poweroff module" 702 depends on X86_32 703 ---help--- 704 The Iris machines from EuroBraille do not have APM or ACPI support 705 to shut themselves down properly. A special I/O sequence is 706 needed to do so, which is what this module does at 707 kernel shutdown. 708 709 This is only for Iris machines from EuroBraille. 710 711 If unused, say N. 712 713config SCHED_OMIT_FRAME_POINTER 714 def_bool y 715 prompt "Single-depth WCHAN output" 716 depends on X86 717 ---help--- 718 Calculate simpler /proc/<PID>/wchan values. If this option 719 is disabled then wchan values will recurse back to the 720 caller function. This provides more accurate wchan values, 721 at the expense of slightly more scheduling overhead. 722 723 If in doubt, say "Y". 724 725menuconfig HYPERVISOR_GUEST 726 bool "Linux guest support" 727 ---help--- 728 Say Y here to enable options for running Linux under various hyper- 729 visors. This option enables basic hypervisor detection and platform 730 setup. 731 732 If you say N, all options in this submenu will be skipped and 733 disabled, and Linux guest support won't be built in. 734 735if HYPERVISOR_GUEST 736 737config PARAVIRT 738 bool "Enable paravirtualization code" 739 ---help--- 740 This changes the kernel so it can modify itself when it is run 741 under a hypervisor, potentially improving performance significantly 742 over full virtualization. However, when run without a hypervisor 743 the kernel is theoretically slower and slightly larger. 744 745config PARAVIRT_DEBUG 746 bool "paravirt-ops debugging" 747 depends on PARAVIRT && DEBUG_KERNEL 748 ---help--- 749 Enable to debug paravirt_ops internals. Specifically, BUG if 750 a paravirt_op is missing when it is called. 751 752config PARAVIRT_SPINLOCKS 753 bool "Paravirtualization layer for spinlocks" 754 depends on PARAVIRT && SMP 755 ---help--- 756 Paravirtualized spinlocks allow a pvops backend to replace the 757 spinlock implementation with something virtualization-friendly 758 (for example, block the virtual CPU rather than spinning). 759 760 It has a minimal impact on native kernels and gives a nice performance 761 benefit on paravirtualized KVM / Xen kernels. 762 763 If you are unsure how to answer this question, answer Y. 764 765config QUEUED_LOCK_STAT 766 bool "Paravirt queued spinlock statistics" 767 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 768 ---help--- 769 Enable the collection of statistical data on the slowpath 770 behavior of paravirtualized queued spinlocks and report 771 them on debugfs. 772 773source "arch/x86/xen/Kconfig" 774 775config KVM_GUEST 776 bool "KVM Guest support (including kvmclock)" 777 depends on PARAVIRT 778 select PARAVIRT_CLOCK 779 default y 780 ---help--- 781 This option enables various optimizations for running under the KVM 782 hypervisor. It includes a paravirtualized clock, so that instead 783 of relying on a PIT (or probably other) emulation by the 784 underlying device model, the host provides the guest with 785 timing infrastructure such as time of day, and system time 786 787config KVM_DEBUG_FS 788 bool "Enable debug information for KVM Guests in debugfs" 789 depends on KVM_GUEST && DEBUG_FS 790 default n 791 ---help--- 792 This option enables collection of various statistics for KVM guest. 793 Statistics are displayed in debugfs filesystem. Enabling this option 794 may incur significant overhead. 795 796config PARAVIRT_TIME_ACCOUNTING 797 bool "Paravirtual steal time accounting" 798 depends on PARAVIRT 799 default n 800 ---help--- 801 Select this option to enable fine granularity task steal time 802 accounting. Time spent executing other tasks in parallel with 803 the current vCPU is discounted from the vCPU power. To account for 804 that, there can be a small performance impact. 805 806 If in doubt, say N here. 807 808config PARAVIRT_CLOCK 809 bool 810 811endif #HYPERVISOR_GUEST 812 813config NO_BOOTMEM 814 def_bool y 815 816source "arch/x86/Kconfig.cpu" 817 818config HPET_TIMER 819 def_bool X86_64 820 prompt "HPET Timer Support" if X86_32 821 ---help--- 822 Use the IA-PC HPET (High Precision Event Timer) to manage 823 time in preference to the PIT and RTC, if a HPET is 824 present. 825 HPET is the next generation timer replacing legacy 8254s. 826 The HPET provides a stable time base on SMP 827 systems, unlike the TSC, but it is more expensive to access, 828 as it is off-chip. The interface used is documented 829 in the HPET spec, revision 1. 830 831 You can safely choose Y here. However, HPET will only be 832 activated if the platform and the BIOS support this feature. 833 Otherwise the 8254 will be used for timing services. 834 835 Choose N to continue using the legacy 8254 timer. 836 837config HPET_EMULATE_RTC 838 def_bool y 839 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 840 841config APB_TIMER 842 def_bool y if X86_INTEL_MID 843 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 844 select DW_APB_TIMER 845 depends on X86_INTEL_MID && SFI 846 help 847 APB timer is the replacement for 8254, HPET on X86 MID platforms. 848 The APBT provides a stable time base on SMP 849 systems, unlike the TSC, but it is more expensive to access, 850 as it is off-chip. APB timers are always running regardless of CPU 851 C states, they are used as per CPU clockevent device when possible. 852 853# Mark as expert because too many people got it wrong. 854# The code disables itself when not needed. 855config DMI 856 default y 857 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 858 bool "Enable DMI scanning" if EXPERT 859 ---help--- 860 Enabled scanning of DMI to identify machine quirks. Say Y 861 here unless you have verified that your setup is not 862 affected by entries in the DMI blacklist. Required by PNP 863 BIOS code. 864 865config GART_IOMMU 866 bool "Old AMD GART IOMMU support" 867 select SWIOTLB 868 depends on X86_64 && PCI && AMD_NB 869 ---help--- 870 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 871 GART based hardware IOMMUs. 872 873 The GART supports full DMA access for devices with 32-bit access 874 limitations, on systems with more than 3 GB. This is usually needed 875 for USB, sound, many IDE/SATA chipsets and some other devices. 876 877 Newer systems typically have a modern AMD IOMMU, supported via 878 the CONFIG_AMD_IOMMU=y config option. 879 880 In normal configurations this driver is only active when needed: 881 there's more than 3 GB of memory and the system contains a 882 32-bit limited device. 883 884 If unsure, say Y. 885 886config CALGARY_IOMMU 887 bool "IBM Calgary IOMMU support" 888 select SWIOTLB 889 depends on X86_64 && PCI 890 ---help--- 891 Support for hardware IOMMUs in IBM's xSeries x366 and x460 892 systems. Needed to run systems with more than 3GB of memory 893 properly with 32-bit PCI devices that do not support DAC 894 (Double Address Cycle). Calgary also supports bus level 895 isolation, where all DMAs pass through the IOMMU. This 896 prevents them from going anywhere except their intended 897 destination. This catches hard-to-find kernel bugs and 898 mis-behaving drivers and devices that do not use the DMA-API 899 properly to set up their DMA buffers. The IOMMU can be 900 turned off at boot time with the iommu=off parameter. 901 Normally the kernel will make the right choice by itself. 902 If unsure, say Y. 903 904config CALGARY_IOMMU_ENABLED_BY_DEFAULT 905 def_bool y 906 prompt "Should Calgary be enabled by default?" 907 depends on CALGARY_IOMMU 908 ---help--- 909 Should Calgary be enabled by default? if you choose 'y', Calgary 910 will be used (if it exists). If you choose 'n', Calgary will not be 911 used even if it exists. If you choose 'n' and would like to use 912 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 913 If unsure, say Y. 914 915# need this always selected by IOMMU for the VIA workaround 916config SWIOTLB 917 def_bool y if X86_64 918 ---help--- 919 Support for software bounce buffers used on x86-64 systems 920 which don't have a hardware IOMMU. Using this PCI devices 921 which can only access 32-bits of memory can be used on systems 922 with more than 3 GB of memory. 923 If unsure, say Y. 924 925config IOMMU_HELPER 926 def_bool y 927 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 928 929config MAXSMP 930 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 931 depends on X86_64 && SMP && DEBUG_KERNEL 932 select CPUMASK_OFFSTACK 933 ---help--- 934 Enable maximum number of CPUS and NUMA Nodes for this architecture. 935 If unsure, say N. 936 937config NR_CPUS 938 int "Maximum number of CPUs" if SMP && !MAXSMP 939 range 2 8 if SMP && X86_32 && !X86_BIGSMP 940 range 2 64 if SMP && X86_32 && X86_BIGSMP 941 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64 942 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 943 default "1" if !SMP 944 default "8192" if MAXSMP 945 default "32" if SMP && X86_BIGSMP 946 default "8" if SMP && X86_32 947 default "64" if SMP 948 ---help--- 949 This allows you to specify the maximum number of CPUs which this 950 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 951 supported value is 8192, otherwise the maximum value is 512. The 952 minimum value which makes sense is 2. 953 954 This is purely to save memory - each supported CPU adds 955 approximately eight kilobytes to the kernel image. 956 957config SCHED_SMT 958 def_bool y if SMP 959 960config SCHED_MC 961 def_bool y 962 prompt "Multi-core scheduler support" 963 depends on SMP 964 ---help--- 965 Multi-core scheduler support improves the CPU scheduler's decision 966 making when dealing with multi-core CPU chips at a cost of slightly 967 increased overhead in some places. If unsure say N here. 968 969config SCHED_MC_PRIO 970 bool "CPU core priorities scheduler support" 971 depends on SCHED_MC && CPU_SUP_INTEL 972 select X86_INTEL_PSTATE 973 select CPU_FREQ 974 default y 975 ---help--- 976 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 977 core ordering determined at manufacturing time, which allows 978 certain cores to reach higher turbo frequencies (when running 979 single threaded workloads) than others. 980 981 Enabling this kernel feature teaches the scheduler about 982 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 983 scheduler's CPU selection logic accordingly, so that higher 984 overall system performance can be achieved. 985 986 This feature will have no effect on CPUs without this feature. 987 988 If unsure say Y here. 989 990source "kernel/Kconfig.preempt" 991 992config UP_LATE_INIT 993 def_bool y 994 depends on !SMP && X86_LOCAL_APIC 995 996config X86_UP_APIC 997 bool "Local APIC support on uniprocessors" if !PCI_MSI 998 default PCI_MSI 999 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1000 ---help--- 1001 A local APIC (Advanced Programmable Interrupt Controller) is an 1002 integrated interrupt controller in the CPU. If you have a single-CPU 1003 system which has a processor with a local APIC, you can say Y here to 1004 enable and use it. If you say Y here even though your machine doesn't 1005 have a local APIC, then the kernel will still run with no slowdown at 1006 all. The local APIC supports CPU-generated self-interrupts (timer, 1007 performance counters), and the NMI watchdog which detects hard 1008 lockups. 1009 1010config X86_UP_IOAPIC 1011 bool "IO-APIC support on uniprocessors" 1012 depends on X86_UP_APIC 1013 ---help--- 1014 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1015 SMP-capable replacement for PC-style interrupt controllers. Most 1016 SMP systems and many recent uniprocessor systems have one. 1017 1018 If you have a single-CPU system with an IO-APIC, you can say Y here 1019 to use it. If you say Y here even though your machine doesn't have 1020 an IO-APIC, then the kernel will still run with no slowdown at all. 1021 1022config X86_LOCAL_APIC 1023 def_bool y 1024 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1025 select IRQ_DOMAIN_HIERARCHY 1026 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1027 1028config X86_IO_APIC 1029 def_bool y 1030 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1031 1032config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1033 bool "Reroute for broken boot IRQs" 1034 depends on X86_IO_APIC 1035 ---help--- 1036 This option enables a workaround that fixes a source of 1037 spurious interrupts. This is recommended when threaded 1038 interrupt handling is used on systems where the generation of 1039 superfluous "boot interrupts" cannot be disabled. 1040 1041 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1042 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1043 kernel does during interrupt handling). On chipsets where this 1044 boot IRQ generation cannot be disabled, this workaround keeps 1045 the original IRQ line masked so that only the equivalent "boot 1046 IRQ" is delivered to the CPUs. The workaround also tells the 1047 kernel to set up the IRQ handler on the boot IRQ line. In this 1048 way only one interrupt is delivered to the kernel. Otherwise 1049 the spurious second interrupt may cause the kernel to bring 1050 down (vital) interrupt lines. 1051 1052 Only affects "broken" chipsets. Interrupt sharing may be 1053 increased on these systems. 1054 1055config X86_MCE 1056 bool "Machine Check / overheating reporting" 1057 select GENERIC_ALLOCATOR 1058 default y 1059 ---help--- 1060 Machine Check support allows the processor to notify the 1061 kernel if it detects a problem (e.g. overheating, data corruption). 1062 The action the kernel takes depends on the severity of the problem, 1063 ranging from warning messages to halting the machine. 1064 1065config X86_MCELOG_LEGACY 1066 bool "Support for deprecated /dev/mcelog character device" 1067 depends on X86_MCE 1068 ---help--- 1069 Enable support for /dev/mcelog which is needed by the old mcelog 1070 userspace logging daemon. Consider switching to the new generation 1071 rasdaemon solution. 1072 1073config X86_MCE_INTEL 1074 def_bool y 1075 prompt "Intel MCE features" 1076 depends on X86_MCE && X86_LOCAL_APIC 1077 ---help--- 1078 Additional support for intel specific MCE features such as 1079 the thermal monitor. 1080 1081config X86_MCE_AMD 1082 def_bool y 1083 prompt "AMD MCE features" 1084 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1085 ---help--- 1086 Additional support for AMD specific MCE features such as 1087 the DRAM Error Threshold. 1088 1089config X86_ANCIENT_MCE 1090 bool "Support for old Pentium 5 / WinChip machine checks" 1091 depends on X86_32 && X86_MCE 1092 ---help--- 1093 Include support for machine check handling on old Pentium 5 or WinChip 1094 systems. These typically need to be enabled explicitly on the command 1095 line. 1096 1097config X86_MCE_THRESHOLD 1098 depends on X86_MCE_AMD || X86_MCE_INTEL 1099 def_bool y 1100 1101config X86_MCE_INJECT 1102 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1103 tristate "Machine check injector support" 1104 ---help--- 1105 Provide support for injecting machine checks for testing purposes. 1106 If you don't know what a machine check is and you don't do kernel 1107 QA it is safe to say n. 1108 1109config X86_THERMAL_VECTOR 1110 def_bool y 1111 depends on X86_MCE_INTEL 1112 1113source "arch/x86/events/Kconfig" 1114 1115config X86_LEGACY_VM86 1116 bool "Legacy VM86 support" 1117 default n 1118 depends on X86_32 1119 ---help--- 1120 This option allows user programs to put the CPU into V8086 1121 mode, which is an 80286-era approximation of 16-bit real mode. 1122 1123 Some very old versions of X and/or vbetool require this option 1124 for user mode setting. Similarly, DOSEMU will use it if 1125 available to accelerate real mode DOS programs. However, any 1126 recent version of DOSEMU, X, or vbetool should be fully 1127 functional even without kernel VM86 support, as they will all 1128 fall back to software emulation. Nevertheless, if you are using 1129 a 16-bit DOS program where 16-bit performance matters, vm86 1130 mode might be faster than emulation and you might want to 1131 enable this option. 1132 1133 Note that any app that works on a 64-bit kernel is unlikely to 1134 need this option, as 64-bit kernels don't, and can't, support 1135 V8086 mode. This option is also unrelated to 16-bit protected 1136 mode and is not needed to run most 16-bit programs under Wine. 1137 1138 Enabling this option increases the complexity of the kernel 1139 and slows down exception handling a tiny bit. 1140 1141 If unsure, say N here. 1142 1143config VM86 1144 bool 1145 default X86_LEGACY_VM86 1146 1147config X86_16BIT 1148 bool "Enable support for 16-bit segments" if EXPERT 1149 default y 1150 depends on MODIFY_LDT_SYSCALL 1151 ---help--- 1152 This option is required by programs like Wine to run 16-bit 1153 protected mode legacy code on x86 processors. Disabling 1154 this option saves about 300 bytes on i386, or around 6K text 1155 plus 16K runtime memory on x86-64, 1156 1157config X86_ESPFIX32 1158 def_bool y 1159 depends on X86_16BIT && X86_32 1160 1161config X86_ESPFIX64 1162 def_bool y 1163 depends on X86_16BIT && X86_64 1164 1165config X86_VSYSCALL_EMULATION 1166 bool "Enable vsyscall emulation" if EXPERT 1167 default y 1168 depends on X86_64 1169 ---help--- 1170 This enables emulation of the legacy vsyscall page. Disabling 1171 it is roughly equivalent to booting with vsyscall=none, except 1172 that it will also disable the helpful warning if a program 1173 tries to use a vsyscall. With this option set to N, offending 1174 programs will just segfault, citing addresses of the form 1175 0xffffffffff600?00. 1176 1177 This option is required by many programs built before 2013, and 1178 care should be used even with newer programs if set to N. 1179 1180 Disabling this option saves about 7K of kernel size and 1181 possibly 4K of additional runtime pagetable memory. 1182 1183config TOSHIBA 1184 tristate "Toshiba Laptop support" 1185 depends on X86_32 1186 ---help--- 1187 This adds a driver to safely access the System Management Mode of 1188 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1189 not work on models with a Phoenix BIOS. The System Management Mode 1190 is used to set the BIOS and power saving options on Toshiba portables. 1191 1192 For information on utilities to make use of this driver see the 1193 Toshiba Linux utilities web site at: 1194 <http://www.buzzard.org.uk/toshiba/>. 1195 1196 Say Y if you intend to run this kernel on a Toshiba portable. 1197 Say N otherwise. 1198 1199config I8K 1200 tristate "Dell i8k legacy laptop support" 1201 select HWMON 1202 select SENSORS_DELL_SMM 1203 ---help--- 1204 This option enables legacy /proc/i8k userspace interface in hwmon 1205 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1206 temperature and allows controlling fan speeds of Dell laptops via 1207 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1208 it reports also power and hotkey status. For fan speed control is 1209 needed userspace package i8kutils. 1210 1211 Say Y if you intend to run this kernel on old Dell laptops or want to 1212 use userspace package i8kutils. 1213 Say N otherwise. 1214 1215config X86_REBOOTFIXUPS 1216 bool "Enable X86 board specific fixups for reboot" 1217 depends on X86_32 1218 ---help--- 1219 This enables chipset and/or board specific fixups to be done 1220 in order to get reboot to work correctly. This is only needed on 1221 some combinations of hardware and BIOS. The symptom, for which 1222 this config is intended, is when reboot ends with a stalled/hung 1223 system. 1224 1225 Currently, the only fixup is for the Geode machines using 1226 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1227 1228 Say Y if you want to enable the fixup. Currently, it's safe to 1229 enable this option even if you don't need it. 1230 Say N otherwise. 1231 1232config MICROCODE 1233 bool "CPU microcode loading support" 1234 default y 1235 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1236 select FW_LOADER 1237 ---help--- 1238 If you say Y here, you will be able to update the microcode on 1239 Intel and AMD processors. The Intel support is for the IA32 family, 1240 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1241 AMD support is for families 0x10 and later. You will obviously need 1242 the actual microcode binary data itself which is not shipped with 1243 the Linux kernel. 1244 1245 The preferred method to load microcode from a detached initrd is described 1246 in Documentation/x86/early-microcode.txt. For that you need to enable 1247 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1248 initrd for microcode blobs. 1249 1250 In addition, you can build-in the microcode into the kernel. For that you 1251 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1252 to the CONFIG_EXTRA_FIRMWARE config option. 1253 1254config MICROCODE_INTEL 1255 bool "Intel microcode loading support" 1256 depends on MICROCODE 1257 default MICROCODE 1258 select FW_LOADER 1259 ---help--- 1260 This options enables microcode patch loading support for Intel 1261 processors. 1262 1263 For the current Intel microcode data package go to 1264 <https://downloadcenter.intel.com> and search for 1265 'Linux Processor Microcode Data File'. 1266 1267config MICROCODE_AMD 1268 bool "AMD microcode loading support" 1269 depends on MICROCODE 1270 select FW_LOADER 1271 ---help--- 1272 If you select this option, microcode patch loading support for AMD 1273 processors will be enabled. 1274 1275config MICROCODE_OLD_INTERFACE 1276 def_bool y 1277 depends on MICROCODE 1278 1279config X86_MSR 1280 tristate "/dev/cpu/*/msr - Model-specific register support" 1281 ---help--- 1282 This device gives privileged processes access to the x86 1283 Model-Specific Registers (MSRs). It is a character device with 1284 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1285 MSR accesses are directed to a specific CPU on multi-processor 1286 systems. 1287 1288config X86_CPUID 1289 tristate "/dev/cpu/*/cpuid - CPU information support" 1290 ---help--- 1291 This device gives processes access to the x86 CPUID instruction to 1292 be executed on a specific processor. It is a character device 1293 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1294 /dev/cpu/31/cpuid. 1295 1296choice 1297 prompt "High Memory Support" 1298 default HIGHMEM4G 1299 depends on X86_32 1300 1301config NOHIGHMEM 1302 bool "off" 1303 ---help--- 1304 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1305 However, the address space of 32-bit x86 processors is only 4 1306 Gigabytes large. That means that, if you have a large amount of 1307 physical memory, not all of it can be "permanently mapped" by the 1308 kernel. The physical memory that's not permanently mapped is called 1309 "high memory". 1310 1311 If you are compiling a kernel which will never run on a machine with 1312 more than 1 Gigabyte total physical RAM, answer "off" here (default 1313 choice and suitable for most users). This will result in a "3GB/1GB" 1314 split: 3GB are mapped so that each process sees a 3GB virtual memory 1315 space and the remaining part of the 4GB virtual memory space is used 1316 by the kernel to permanently map as much physical memory as 1317 possible. 1318 1319 If the machine has between 1 and 4 Gigabytes physical RAM, then 1320 answer "4GB" here. 1321 1322 If more than 4 Gigabytes is used then answer "64GB" here. This 1323 selection turns Intel PAE (Physical Address Extension) mode on. 1324 PAE implements 3-level paging on IA32 processors. PAE is fully 1325 supported by Linux, PAE mode is implemented on all recent Intel 1326 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1327 then the kernel will not boot on CPUs that don't support PAE! 1328 1329 The actual amount of total physical memory will either be 1330 auto detected or can be forced by using a kernel command line option 1331 such as "mem=256M". (Try "man bootparam" or see the documentation of 1332 your boot loader (lilo or loadlin) about how to pass options to the 1333 kernel at boot time.) 1334 1335 If unsure, say "off". 1336 1337config HIGHMEM4G 1338 bool "4GB" 1339 ---help--- 1340 Select this if you have a 32-bit processor and between 1 and 4 1341 gigabytes of physical RAM. 1342 1343config HIGHMEM64G 1344 bool "64GB" 1345 depends on !M486 1346 select X86_PAE 1347 ---help--- 1348 Select this if you have a 32-bit processor and more than 4 1349 gigabytes of physical RAM. 1350 1351endchoice 1352 1353choice 1354 prompt "Memory split" if EXPERT 1355 default VMSPLIT_3G 1356 depends on X86_32 1357 ---help--- 1358 Select the desired split between kernel and user memory. 1359 1360 If the address range available to the kernel is less than the 1361 physical memory installed, the remaining memory will be available 1362 as "high memory". Accessing high memory is a little more costly 1363 than low memory, as it needs to be mapped into the kernel first. 1364 Note that increasing the kernel address space limits the range 1365 available to user programs, making the address space there 1366 tighter. Selecting anything other than the default 3G/1G split 1367 will also likely make your kernel incompatible with binary-only 1368 kernel modules. 1369 1370 If you are not absolutely sure what you are doing, leave this 1371 option alone! 1372 1373 config VMSPLIT_3G 1374 bool "3G/1G user/kernel split" 1375 config VMSPLIT_3G_OPT 1376 depends on !X86_PAE 1377 bool "3G/1G user/kernel split (for full 1G low memory)" 1378 config VMSPLIT_2G 1379 bool "2G/2G user/kernel split" 1380 config VMSPLIT_2G_OPT 1381 depends on !X86_PAE 1382 bool "2G/2G user/kernel split (for full 2G low memory)" 1383 config VMSPLIT_1G 1384 bool "1G/3G user/kernel split" 1385endchoice 1386 1387config PAGE_OFFSET 1388 hex 1389 default 0xB0000000 if VMSPLIT_3G_OPT 1390 default 0x80000000 if VMSPLIT_2G 1391 default 0x78000000 if VMSPLIT_2G_OPT 1392 default 0x40000000 if VMSPLIT_1G 1393 default 0xC0000000 1394 depends on X86_32 1395 1396config HIGHMEM 1397 def_bool y 1398 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1399 1400config X86_PAE 1401 bool "PAE (Physical Address Extension) Support" 1402 depends on X86_32 && !HIGHMEM4G 1403 select SWIOTLB 1404 ---help--- 1405 PAE is required for NX support, and furthermore enables 1406 larger swapspace support for non-overcommit purposes. It 1407 has the cost of more pagetable lookup overhead, and also 1408 consumes more pagetable space per process. 1409 1410config X86_5LEVEL 1411 bool "Enable 5-level page tables support" 1412 depends on X86_64 1413 ---help--- 1414 5-level paging enables access to larger address space: 1415 upto 128 PiB of virtual address space and 4 PiB of 1416 physical address space. 1417 1418 It will be supported by future Intel CPUs. 1419 1420 Note: a kernel with this option enabled can only be booted 1421 on machines that support the feature. 1422 1423 See Documentation/x86/x86_64/5level-paging.txt for more 1424 information. 1425 1426 Say N if unsure. 1427 1428config ARCH_PHYS_ADDR_T_64BIT 1429 def_bool y 1430 depends on X86_64 || X86_PAE 1431 1432config ARCH_DMA_ADDR_T_64BIT 1433 def_bool y 1434 depends on X86_64 || HIGHMEM64G 1435 1436config X86_DIRECT_GBPAGES 1437 def_bool y 1438 depends on X86_64 && !DEBUG_PAGEALLOC 1439 ---help--- 1440 Certain kernel features effectively disable kernel 1441 linear 1 GB mappings (even if the CPU otherwise 1442 supports them), so don't confuse the user by printing 1443 that we have them enabled. 1444 1445config ARCH_HAS_MEM_ENCRYPT 1446 def_bool y 1447 1448config AMD_MEM_ENCRYPT 1449 bool "AMD Secure Memory Encryption (SME) support" 1450 depends on X86_64 && CPU_SUP_AMD 1451 ---help--- 1452 Say yes to enable support for the encryption of system memory. 1453 This requires an AMD processor that supports Secure Memory 1454 Encryption (SME). 1455 1456config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1457 bool "Activate AMD Secure Memory Encryption (SME) by default" 1458 default y 1459 depends on AMD_MEM_ENCRYPT 1460 ---help--- 1461 Say yes to have system memory encrypted by default if running on 1462 an AMD processor that supports Secure Memory Encryption (SME). 1463 1464 If set to Y, then the encryption of system memory can be 1465 deactivated with the mem_encrypt=off command line option. 1466 1467 If set to N, then the encryption of system memory can be 1468 activated with the mem_encrypt=on command line option. 1469 1470config ARCH_USE_MEMREMAP_PROT 1471 def_bool y 1472 depends on AMD_MEM_ENCRYPT 1473 1474# Common NUMA Features 1475config NUMA 1476 bool "Numa Memory Allocation and Scheduler Support" 1477 depends on SMP 1478 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1479 default y if X86_BIGSMP 1480 ---help--- 1481 Enable NUMA (Non Uniform Memory Access) support. 1482 1483 The kernel will try to allocate memory used by a CPU on the 1484 local memory controller of the CPU and add some more 1485 NUMA awareness to the kernel. 1486 1487 For 64-bit this is recommended if the system is Intel Core i7 1488 (or later), AMD Opteron, or EM64T NUMA. 1489 1490 For 32-bit this is only needed if you boot a 32-bit 1491 kernel on a 64-bit NUMA platform. 1492 1493 Otherwise, you should say N. 1494 1495config AMD_NUMA 1496 def_bool y 1497 prompt "Old style AMD Opteron NUMA detection" 1498 depends on X86_64 && NUMA && PCI 1499 ---help--- 1500 Enable AMD NUMA node topology detection. You should say Y here if 1501 you have a multi processor AMD system. This uses an old method to 1502 read the NUMA configuration directly from the builtin Northbridge 1503 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1504 which also takes priority if both are compiled in. 1505 1506config X86_64_ACPI_NUMA 1507 def_bool y 1508 prompt "ACPI NUMA detection" 1509 depends on X86_64 && NUMA && ACPI && PCI 1510 select ACPI_NUMA 1511 ---help--- 1512 Enable ACPI SRAT based node topology detection. 1513 1514# Some NUMA nodes have memory ranges that span 1515# other nodes. Even though a pfn is valid and 1516# between a node's start and end pfns, it may not 1517# reside on that node. See memmap_init_zone() 1518# for details. 1519config NODES_SPAN_OTHER_NODES 1520 def_bool y 1521 depends on X86_64_ACPI_NUMA 1522 1523config NUMA_EMU 1524 bool "NUMA emulation" 1525 depends on NUMA 1526 ---help--- 1527 Enable NUMA emulation. A flat machine will be split 1528 into virtual nodes when booted with "numa=fake=N", where N is the 1529 number of nodes. This is only useful for debugging. 1530 1531config NODES_SHIFT 1532 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1533 range 1 10 1534 default "10" if MAXSMP 1535 default "6" if X86_64 1536 default "3" 1537 depends on NEED_MULTIPLE_NODES 1538 ---help--- 1539 Specify the maximum number of NUMA Nodes available on the target 1540 system. Increases memory reserved to accommodate various tables. 1541 1542config ARCH_HAVE_MEMORY_PRESENT 1543 def_bool y 1544 depends on X86_32 && DISCONTIGMEM 1545 1546config NEED_NODE_MEMMAP_SIZE 1547 def_bool y 1548 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1549 1550config ARCH_FLATMEM_ENABLE 1551 def_bool y 1552 depends on X86_32 && !NUMA 1553 1554config ARCH_DISCONTIGMEM_ENABLE 1555 def_bool y 1556 depends on NUMA && X86_32 1557 1558config ARCH_DISCONTIGMEM_DEFAULT 1559 def_bool y 1560 depends on NUMA && X86_32 1561 1562config ARCH_SPARSEMEM_ENABLE 1563 def_bool y 1564 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1565 select SPARSEMEM_STATIC if X86_32 1566 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1567 1568config ARCH_SPARSEMEM_DEFAULT 1569 def_bool y 1570 depends on X86_64 1571 1572config ARCH_SELECT_MEMORY_MODEL 1573 def_bool y 1574 depends on ARCH_SPARSEMEM_ENABLE 1575 1576config ARCH_MEMORY_PROBE 1577 bool "Enable sysfs memory/probe interface" 1578 depends on X86_64 && MEMORY_HOTPLUG 1579 help 1580 This option enables a sysfs memory/probe interface for testing. 1581 See Documentation/memory-hotplug.txt for more information. 1582 If you are unsure how to answer this question, answer N. 1583 1584config ARCH_PROC_KCORE_TEXT 1585 def_bool y 1586 depends on X86_64 && PROC_KCORE 1587 1588config ILLEGAL_POINTER_VALUE 1589 hex 1590 default 0 if X86_32 1591 default 0xdead000000000000 if X86_64 1592 1593source "mm/Kconfig" 1594 1595config X86_PMEM_LEGACY_DEVICE 1596 bool 1597 1598config X86_PMEM_LEGACY 1599 tristate "Support non-standard NVDIMMs and ADR protected memory" 1600 depends on PHYS_ADDR_T_64BIT 1601 depends on BLK_DEV 1602 select X86_PMEM_LEGACY_DEVICE 1603 select LIBNVDIMM 1604 help 1605 Treat memory marked using the non-standard e820 type of 12 as used 1606 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1607 The kernel will offer these regions to the 'pmem' driver so 1608 they can be used for persistent storage. 1609 1610 Say Y if unsure. 1611 1612config HIGHPTE 1613 bool "Allocate 3rd-level pagetables from highmem" 1614 depends on HIGHMEM 1615 ---help--- 1616 The VM uses one page table entry for each page of physical memory. 1617 For systems with a lot of RAM, this can be wasteful of precious 1618 low memory. Setting this option will put user-space page table 1619 entries in high memory. 1620 1621config X86_CHECK_BIOS_CORRUPTION 1622 bool "Check for low memory corruption" 1623 ---help--- 1624 Periodically check for memory corruption in low memory, which 1625 is suspected to be caused by BIOS. Even when enabled in the 1626 configuration, it is disabled at runtime. Enable it by 1627 setting "memory_corruption_check=1" on the kernel command 1628 line. By default it scans the low 64k of memory every 60 1629 seconds; see the memory_corruption_check_size and 1630 memory_corruption_check_period parameters in 1631 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1632 1633 When enabled with the default parameters, this option has 1634 almost no overhead, as it reserves a relatively small amount 1635 of memory and scans it infrequently. It both detects corruption 1636 and prevents it from affecting the running system. 1637 1638 It is, however, intended as a diagnostic tool; if repeatable 1639 BIOS-originated corruption always affects the same memory, 1640 you can use memmap= to prevent the kernel from using that 1641 memory. 1642 1643config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1644 bool "Set the default setting of memory_corruption_check" 1645 depends on X86_CHECK_BIOS_CORRUPTION 1646 default y 1647 ---help--- 1648 Set whether the default state of memory_corruption_check is 1649 on or off. 1650 1651config X86_RESERVE_LOW 1652 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1653 default 64 1654 range 4 640 1655 ---help--- 1656 Specify the amount of low memory to reserve for the BIOS. 1657 1658 The first page contains BIOS data structures that the kernel 1659 must not use, so that page must always be reserved. 1660 1661 By default we reserve the first 64K of physical RAM, as a 1662 number of BIOSes are known to corrupt that memory range 1663 during events such as suspend/resume or monitor cable 1664 insertion, so it must not be used by the kernel. 1665 1666 You can set this to 4 if you are absolutely sure that you 1667 trust the BIOS to get all its memory reservations and usages 1668 right. If you know your BIOS have problems beyond the 1669 default 64K area, you can set this to 640 to avoid using the 1670 entire low memory range. 1671 1672 If you have doubts about the BIOS (e.g. suspend/resume does 1673 not work or there's kernel crashes after certain hardware 1674 hotplug events) then you might want to enable 1675 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1676 typical corruption patterns. 1677 1678 Leave this to the default value of 64 if you are unsure. 1679 1680config MATH_EMULATION 1681 bool 1682 depends on MODIFY_LDT_SYSCALL 1683 prompt "Math emulation" if X86_32 1684 ---help--- 1685 Linux can emulate a math coprocessor (used for floating point 1686 operations) if you don't have one. 486DX and Pentium processors have 1687 a math coprocessor built in, 486SX and 386 do not, unless you added 1688 a 487DX or 387, respectively. (The messages during boot time can 1689 give you some hints here ["man dmesg"].) Everyone needs either a 1690 coprocessor or this emulation. 1691 1692 If you don't have a math coprocessor, you need to say Y here; if you 1693 say Y here even though you have a coprocessor, the coprocessor will 1694 be used nevertheless. (This behavior can be changed with the kernel 1695 command line option "no387", which comes handy if your coprocessor 1696 is broken. Try "man bootparam" or see the documentation of your boot 1697 loader (lilo or loadlin) about how to pass options to the kernel at 1698 boot time.) This means that it is a good idea to say Y here if you 1699 intend to use this kernel on different machines. 1700 1701 More information about the internals of the Linux math coprocessor 1702 emulation can be found in <file:arch/x86/math-emu/README>. 1703 1704 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1705 kernel, it won't hurt. 1706 1707config MTRR 1708 def_bool y 1709 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1710 ---help--- 1711 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1712 the Memory Type Range Registers (MTRRs) may be used to control 1713 processor access to memory ranges. This is most useful if you have 1714 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1715 allows bus write transfers to be combined into a larger transfer 1716 before bursting over the PCI/AGP bus. This can increase performance 1717 of image write operations 2.5 times or more. Saying Y here creates a 1718 /proc/mtrr file which may be used to manipulate your processor's 1719 MTRRs. Typically the X server should use this. 1720 1721 This code has a reasonably generic interface so that similar 1722 control registers on other processors can be easily supported 1723 as well: 1724 1725 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1726 Registers (ARRs) which provide a similar functionality to MTRRs. For 1727 these, the ARRs are used to emulate the MTRRs. 1728 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1729 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1730 write-combining. All of these processors are supported by this code 1731 and it makes sense to say Y here if you have one of them. 1732 1733 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1734 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1735 can lead to all sorts of problems, so it's good to say Y here. 1736 1737 You can safely say Y even if your machine doesn't have MTRRs, you'll 1738 just add about 9 KB to your kernel. 1739 1740 See <file:Documentation/x86/mtrr.txt> for more information. 1741 1742config MTRR_SANITIZER 1743 def_bool y 1744 prompt "MTRR cleanup support" 1745 depends on MTRR 1746 ---help--- 1747 Convert MTRR layout from continuous to discrete, so X drivers can 1748 add writeback entries. 1749 1750 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1751 The largest mtrr entry size for a continuous block can be set with 1752 mtrr_chunk_size. 1753 1754 If unsure, say Y. 1755 1756config MTRR_SANITIZER_ENABLE_DEFAULT 1757 int "MTRR cleanup enable value (0-1)" 1758 range 0 1 1759 default "0" 1760 depends on MTRR_SANITIZER 1761 ---help--- 1762 Enable mtrr cleanup default value 1763 1764config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1765 int "MTRR cleanup spare reg num (0-7)" 1766 range 0 7 1767 default "1" 1768 depends on MTRR_SANITIZER 1769 ---help--- 1770 mtrr cleanup spare entries default, it can be changed via 1771 mtrr_spare_reg_nr=N on the kernel command line. 1772 1773config X86_PAT 1774 def_bool y 1775 prompt "x86 PAT support" if EXPERT 1776 depends on MTRR 1777 ---help--- 1778 Use PAT attributes to setup page level cache control. 1779 1780 PATs are the modern equivalents of MTRRs and are much more 1781 flexible than MTRRs. 1782 1783 Say N here if you see bootup problems (boot crash, boot hang, 1784 spontaneous reboots) or a non-working video driver. 1785 1786 If unsure, say Y. 1787 1788config ARCH_USES_PG_UNCACHED 1789 def_bool y 1790 depends on X86_PAT 1791 1792config ARCH_RANDOM 1793 def_bool y 1794 prompt "x86 architectural random number generator" if EXPERT 1795 ---help--- 1796 Enable the x86 architectural RDRAND instruction 1797 (Intel Bull Mountain technology) to generate random numbers. 1798 If supported, this is a high bandwidth, cryptographically 1799 secure hardware random number generator. 1800 1801config X86_SMAP 1802 def_bool y 1803 prompt "Supervisor Mode Access Prevention" if EXPERT 1804 ---help--- 1805 Supervisor Mode Access Prevention (SMAP) is a security 1806 feature in newer Intel processors. There is a small 1807 performance cost if this enabled and turned on; there is 1808 also a small increase in the kernel size if this is enabled. 1809 1810 If unsure, say Y. 1811 1812config X86_INTEL_MPX 1813 prompt "Intel MPX (Memory Protection Extensions)" 1814 def_bool n 1815 # Note: only available in 64-bit mode due to VMA flags shortage 1816 depends on CPU_SUP_INTEL && X86_64 1817 select ARCH_USES_HIGH_VMA_FLAGS 1818 ---help--- 1819 MPX provides hardware features that can be used in 1820 conjunction with compiler-instrumented code to check 1821 memory references. It is designed to detect buffer 1822 overflow or underflow bugs. 1823 1824 This option enables running applications which are 1825 instrumented or otherwise use MPX. It does not use MPX 1826 itself inside the kernel or to protect the kernel 1827 against bad memory references. 1828 1829 Enabling this option will make the kernel larger: 1830 ~8k of kernel text and 36 bytes of data on a 64-bit 1831 defconfig. It adds a long to the 'mm_struct' which 1832 will increase the kernel memory overhead of each 1833 process and adds some branches to paths used during 1834 exec() and munmap(). 1835 1836 For details, see Documentation/x86/intel_mpx.txt 1837 1838 If unsure, say N. 1839 1840config X86_INTEL_MEMORY_PROTECTION_KEYS 1841 prompt "Intel Memory Protection Keys" 1842 def_bool y 1843 # Note: only available in 64-bit mode 1844 depends on CPU_SUP_INTEL && X86_64 1845 select ARCH_USES_HIGH_VMA_FLAGS 1846 select ARCH_HAS_PKEYS 1847 ---help--- 1848 Memory Protection Keys provides a mechanism for enforcing 1849 page-based protections, but without requiring modification of the 1850 page tables when an application changes protection domains. 1851 1852 For details, see Documentation/x86/protection-keys.txt 1853 1854 If unsure, say y. 1855 1856choice 1857 prompt "TSX enable mode" 1858 depends on CPU_SUP_INTEL 1859 default X86_INTEL_TSX_MODE_OFF 1860 help 1861 Intel's TSX (Transactional Synchronization Extensions) feature 1862 allows to optimize locking protocols through lock elision which 1863 can lead to a noticeable performance boost. 1864 1865 On the other hand it has been shown that TSX can be exploited 1866 to form side channel attacks (e.g. TAA) and chances are there 1867 will be more of those attacks discovered in the future. 1868 1869 Therefore TSX is not enabled by default (aka tsx=off). An admin 1870 might override this decision by tsx=on the command line parameter. 1871 Even with TSX enabled, the kernel will attempt to enable the best 1872 possible TAA mitigation setting depending on the microcode available 1873 for the particular machine. 1874 1875 This option allows to set the default tsx mode between tsx=on, =off 1876 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1877 details. 1878 1879 Say off if not sure, auto if TSX is in use but it should be used on safe 1880 platforms or on if TSX is in use and the security aspect of tsx is not 1881 relevant. 1882 1883config X86_INTEL_TSX_MODE_OFF 1884 bool "off" 1885 help 1886 TSX is disabled if possible - equals to tsx=off command line parameter. 1887 1888config X86_INTEL_TSX_MODE_ON 1889 bool "on" 1890 help 1891 TSX is always enabled on TSX capable HW - equals the tsx=on command 1892 line parameter. 1893 1894config X86_INTEL_TSX_MODE_AUTO 1895 bool "auto" 1896 help 1897 TSX is enabled on TSX capable HW that is believed to be safe against 1898 side channel attacks- equals the tsx=auto command line parameter. 1899endchoice 1900 1901config EFI 1902 bool "EFI runtime service support" 1903 depends on ACPI 1904 select UCS2_STRING 1905 select EFI_RUNTIME_WRAPPERS 1906 ---help--- 1907 This enables the kernel to use EFI runtime services that are 1908 available (such as the EFI variable services). 1909 1910 This option is only useful on systems that have EFI firmware. 1911 In addition, you should use the latest ELILO loader available 1912 at <http://elilo.sourceforge.net> in order to take advantage 1913 of EFI runtime services. However, even with this option, the 1914 resultant kernel should continue to boot on existing non-EFI 1915 platforms. 1916 1917config EFI_STUB 1918 bool "EFI stub support" 1919 depends on EFI && !X86_USE_3DNOW 1920 select RELOCATABLE 1921 ---help--- 1922 This kernel feature allows a bzImage to be loaded directly 1923 by EFI firmware without the use of a bootloader. 1924 1925 See Documentation/efi-stub.txt for more information. 1926 1927config EFI_MIXED 1928 bool "EFI mixed-mode support" 1929 depends on EFI_STUB && X86_64 1930 ---help--- 1931 Enabling this feature allows a 64-bit kernel to be booted 1932 on a 32-bit firmware, provided that your CPU supports 64-bit 1933 mode. 1934 1935 Note that it is not possible to boot a mixed-mode enabled 1936 kernel via the EFI boot stub - a bootloader that supports 1937 the EFI handover protocol must be used. 1938 1939 If unsure, say N. 1940 1941config SECCOMP 1942 def_bool y 1943 prompt "Enable seccomp to safely compute untrusted bytecode" 1944 ---help--- 1945 This kernel feature is useful for number crunching applications 1946 that may need to compute untrusted bytecode during their 1947 execution. By using pipes or other transports made available to 1948 the process as file descriptors supporting the read/write 1949 syscalls, it's possible to isolate those applications in 1950 their own address space using seccomp. Once seccomp is 1951 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1952 and the task is only allowed to execute a few safe syscalls 1953 defined by each seccomp mode. 1954 1955 If unsure, say Y. Only embedded should say N here. 1956 1957source kernel/Kconfig.hz 1958 1959config KEXEC 1960 bool "kexec system call" 1961 select KEXEC_CORE 1962 ---help--- 1963 kexec is a system call that implements the ability to shutdown your 1964 current kernel, and to start another kernel. It is like a reboot 1965 but it is independent of the system firmware. And like a reboot 1966 you can start any kernel with it, not just Linux. 1967 1968 The name comes from the similarity to the exec system call. 1969 1970 It is an ongoing process to be certain the hardware in a machine 1971 is properly shutdown, so do not be surprised if this code does not 1972 initially work for you. As of this writing the exact hardware 1973 interface is strongly in flux, so no good recommendation can be 1974 made. 1975 1976config KEXEC_FILE 1977 bool "kexec file based system call" 1978 select KEXEC_CORE 1979 select BUILD_BIN2C 1980 depends on X86_64 1981 depends on CRYPTO=y 1982 depends on CRYPTO_SHA256=y 1983 ---help--- 1984 This is new version of kexec system call. This system call is 1985 file based and takes file descriptors as system call argument 1986 for kernel and initramfs as opposed to list of segments as 1987 accepted by previous system call. 1988 1989config KEXEC_VERIFY_SIG 1990 bool "Verify kernel signature during kexec_file_load() syscall" 1991 depends on KEXEC_FILE 1992 ---help--- 1993 This option makes kernel signature verification mandatory for 1994 the kexec_file_load() syscall. 1995 1996 In addition to that option, you need to enable signature 1997 verification for the corresponding kernel image type being 1998 loaded in order for this to work. 1999 2000config KEXEC_BZIMAGE_VERIFY_SIG 2001 bool "Enable bzImage signature verification support" 2002 depends on KEXEC_VERIFY_SIG 2003 depends on SIGNED_PE_FILE_VERIFICATION 2004 select SYSTEM_TRUSTED_KEYRING 2005 ---help--- 2006 Enable bzImage signature verification support. 2007 2008config CRASH_DUMP 2009 bool "kernel crash dumps" 2010 depends on X86_64 || (X86_32 && HIGHMEM) 2011 ---help--- 2012 Generate crash dump after being started by kexec. 2013 This should be normally only set in special crash dump kernels 2014 which are loaded in the main kernel with kexec-tools into 2015 a specially reserved region and then later executed after 2016 a crash by kdump/kexec. The crash dump kernel must be compiled 2017 to a memory address not used by the main kernel or BIOS using 2018 PHYSICAL_START, or it must be built as a relocatable image 2019 (CONFIG_RELOCATABLE=y). 2020 For more details see Documentation/kdump/kdump.txt 2021 2022config KEXEC_JUMP 2023 bool "kexec jump" 2024 depends on KEXEC && HIBERNATION 2025 ---help--- 2026 Jump between original kernel and kexeced kernel and invoke 2027 code in physical address mode via KEXEC 2028 2029config PHYSICAL_START 2030 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2031 default "0x1000000" 2032 ---help--- 2033 This gives the physical address where the kernel is loaded. 2034 2035 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2036 bzImage will decompress itself to above physical address and 2037 run from there. Otherwise, bzImage will run from the address where 2038 it has been loaded by the boot loader and will ignore above physical 2039 address. 2040 2041 In normal kdump cases one does not have to set/change this option 2042 as now bzImage can be compiled as a completely relocatable image 2043 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2044 address. This option is mainly useful for the folks who don't want 2045 to use a bzImage for capturing the crash dump and want to use a 2046 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2047 to be specifically compiled to run from a specific memory area 2048 (normally a reserved region) and this option comes handy. 2049 2050 So if you are using bzImage for capturing the crash dump, 2051 leave the value here unchanged to 0x1000000 and set 2052 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2053 for capturing the crash dump change this value to start of 2054 the reserved region. In other words, it can be set based on 2055 the "X" value as specified in the "crashkernel=YM@XM" 2056 command line boot parameter passed to the panic-ed 2057 kernel. Please take a look at Documentation/kdump/kdump.txt 2058 for more details about crash dumps. 2059 2060 Usage of bzImage for capturing the crash dump is recommended as 2061 one does not have to build two kernels. Same kernel can be used 2062 as production kernel and capture kernel. Above option should have 2063 gone away after relocatable bzImage support is introduced. But it 2064 is present because there are users out there who continue to use 2065 vmlinux for dump capture. This option should go away down the 2066 line. 2067 2068 Don't change this unless you know what you are doing. 2069 2070config RELOCATABLE 2071 bool "Build a relocatable kernel" 2072 default y 2073 ---help--- 2074 This builds a kernel image that retains relocation information 2075 so it can be loaded someplace besides the default 1MB. 2076 The relocations tend to make the kernel binary about 10% larger, 2077 but are discarded at runtime. 2078 2079 One use is for the kexec on panic case where the recovery kernel 2080 must live at a different physical address than the primary 2081 kernel. 2082 2083 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2084 it has been loaded at and the compile time physical address 2085 (CONFIG_PHYSICAL_START) is used as the minimum location. 2086 2087config RANDOMIZE_BASE 2088 bool "Randomize the address of the kernel image (KASLR)" 2089 depends on RELOCATABLE 2090 default y 2091 ---help--- 2092 In support of Kernel Address Space Layout Randomization (KASLR), 2093 this randomizes the physical address at which the kernel image 2094 is decompressed and the virtual address where the kernel 2095 image is mapped, as a security feature that deters exploit 2096 attempts relying on knowledge of the location of kernel 2097 code internals. 2098 2099 On 64-bit, the kernel physical and virtual addresses are 2100 randomized separately. The physical address will be anywhere 2101 between 16MB and the top of physical memory (up to 64TB). The 2102 virtual address will be randomized from 16MB up to 1GB (9 bits 2103 of entropy). Note that this also reduces the memory space 2104 available to kernel modules from 1.5GB to 1GB. 2105 2106 On 32-bit, the kernel physical and virtual addresses are 2107 randomized together. They will be randomized from 16MB up to 2108 512MB (8 bits of entropy). 2109 2110 Entropy is generated using the RDRAND instruction if it is 2111 supported. If RDTSC is supported, its value is mixed into 2112 the entropy pool as well. If neither RDRAND nor RDTSC are 2113 supported, then entropy is read from the i8254 timer. The 2114 usable entropy is limited by the kernel being built using 2115 2GB addressing, and that PHYSICAL_ALIGN must be at a 2116 minimum of 2MB. As a result, only 10 bits of entropy are 2117 theoretically possible, but the implementations are further 2118 limited due to memory layouts. 2119 2120 If unsure, say Y. 2121 2122# Relocation on x86 needs some additional build support 2123config X86_NEED_RELOCS 2124 def_bool y 2125 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2126 2127config PHYSICAL_ALIGN 2128 hex "Alignment value to which kernel should be aligned" 2129 default "0x200000" 2130 range 0x2000 0x1000000 if X86_32 2131 range 0x200000 0x1000000 if X86_64 2132 ---help--- 2133 This value puts the alignment restrictions on physical address 2134 where kernel is loaded and run from. Kernel is compiled for an 2135 address which meets above alignment restriction. 2136 2137 If bootloader loads the kernel at a non-aligned address and 2138 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2139 address aligned to above value and run from there. 2140 2141 If bootloader loads the kernel at a non-aligned address and 2142 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2143 load address and decompress itself to the address it has been 2144 compiled for and run from there. The address for which kernel is 2145 compiled already meets above alignment restrictions. Hence the 2146 end result is that kernel runs from a physical address meeting 2147 above alignment restrictions. 2148 2149 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2150 this value must be a multiple of 0x200000. 2151 2152 Don't change this unless you know what you are doing. 2153 2154config RANDOMIZE_MEMORY 2155 bool "Randomize the kernel memory sections" 2156 depends on X86_64 2157 depends on RANDOMIZE_BASE 2158 default RANDOMIZE_BASE 2159 ---help--- 2160 Randomizes the base virtual address of kernel memory sections 2161 (physical memory mapping, vmalloc & vmemmap). This security feature 2162 makes exploits relying on predictable memory locations less reliable. 2163 2164 The order of allocations remains unchanged. Entropy is generated in 2165 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2166 configuration have in average 30,000 different possible virtual 2167 addresses for each memory section. 2168 2169 If unsure, say Y. 2170 2171config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2172 hex "Physical memory mapping padding" if EXPERT 2173 depends on RANDOMIZE_MEMORY 2174 default "0xa" if MEMORY_HOTPLUG 2175 default "0x0" 2176 range 0x1 0x40 if MEMORY_HOTPLUG 2177 range 0x0 0x40 2178 ---help--- 2179 Define the padding in terabytes added to the existing physical 2180 memory size during kernel memory randomization. It is useful 2181 for memory hotplug support but reduces the entropy available for 2182 address randomization. 2183 2184 If unsure, leave at the default value. 2185 2186config HOTPLUG_CPU 2187 def_bool y 2188 depends on SMP 2189 2190config BOOTPARAM_HOTPLUG_CPU0 2191 bool "Set default setting of cpu0_hotpluggable" 2192 default n 2193 depends on HOTPLUG_CPU 2194 ---help--- 2195 Set whether default state of cpu0_hotpluggable is on or off. 2196 2197 Say Y here to enable CPU0 hotplug by default. If this switch 2198 is turned on, there is no need to give cpu0_hotplug kernel 2199 parameter and the CPU0 hotplug feature is enabled by default. 2200 2201 Please note: there are two known CPU0 dependencies if you want 2202 to enable the CPU0 hotplug feature either by this switch or by 2203 cpu0_hotplug kernel parameter. 2204 2205 First, resume from hibernate or suspend always starts from CPU0. 2206 So hibernate and suspend are prevented if CPU0 is offline. 2207 2208 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2209 offline if any interrupt can not migrate out of CPU0. There may 2210 be other CPU0 dependencies. 2211 2212 Please make sure the dependencies are under your control before 2213 you enable this feature. 2214 2215 Say N if you don't want to enable CPU0 hotplug feature by default. 2216 You still can enable the CPU0 hotplug feature at boot by kernel 2217 parameter cpu0_hotplug. 2218 2219config DEBUG_HOTPLUG_CPU0 2220 def_bool n 2221 prompt "Debug CPU0 hotplug" 2222 depends on HOTPLUG_CPU 2223 ---help--- 2224 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2225 soon as possible and boots up userspace with CPU0 offlined. User 2226 can online CPU0 back after boot time. 2227 2228 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2229 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2230 compilation or giving cpu0_hotplug kernel parameter at boot. 2231 2232 If unsure, say N. 2233 2234config COMPAT_VDSO 2235 def_bool n 2236 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2237 depends on COMPAT_32 2238 ---help--- 2239 Certain buggy versions of glibc will crash if they are 2240 presented with a 32-bit vDSO that is not mapped at the address 2241 indicated in its segment table. 2242 2243 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2244 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2245 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2246 the only released version with the bug, but OpenSUSE 9 2247 contains a buggy "glibc 2.3.2". 2248 2249 The symptom of the bug is that everything crashes on startup, saying: 2250 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2251 2252 Saying Y here changes the default value of the vdso32 boot 2253 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2254 This works around the glibc bug but hurts performance. 2255 2256 If unsure, say N: if you are compiling your own kernel, you 2257 are unlikely to be using a buggy version of glibc. 2258 2259choice 2260 prompt "vsyscall table for legacy applications" 2261 depends on X86_64 2262 default LEGACY_VSYSCALL_EMULATE 2263 help 2264 Legacy user code that does not know how to find the vDSO expects 2265 to be able to issue three syscalls by calling fixed addresses in 2266 kernel space. Since this location is not randomized with ASLR, 2267 it can be used to assist security vulnerability exploitation. 2268 2269 This setting can be changed at boot time via the kernel command 2270 line parameter vsyscall=[native|emulate|none]. 2271 2272 On a system with recent enough glibc (2.14 or newer) and no 2273 static binaries, you can say None without a performance penalty 2274 to improve security. 2275 2276 If unsure, select "Emulate". 2277 2278 config LEGACY_VSYSCALL_NATIVE 2279 bool "Native" 2280 help 2281 Actual executable code is located in the fixed vsyscall 2282 address mapping, implementing time() efficiently. Since 2283 this makes the mapping executable, it can be used during 2284 security vulnerability exploitation (traditionally as 2285 ROP gadgets). This configuration is not recommended. 2286 2287 config LEGACY_VSYSCALL_EMULATE 2288 bool "Emulate" 2289 help 2290 The kernel traps and emulates calls into the fixed 2291 vsyscall address mapping. This makes the mapping 2292 non-executable, but it still contains known contents, 2293 which could be used in certain rare security vulnerability 2294 exploits. This configuration is recommended when userspace 2295 still uses the vsyscall area. 2296 2297 config LEGACY_VSYSCALL_NONE 2298 bool "None" 2299 help 2300 There will be no vsyscall mapping at all. This will 2301 eliminate any risk of ASLR bypass due to the vsyscall 2302 fixed address mapping. Attempts to use the vsyscalls 2303 will be reported to dmesg, so that either old or 2304 malicious userspace programs can be identified. 2305 2306endchoice 2307 2308config CMDLINE_BOOL 2309 bool "Built-in kernel command line" 2310 ---help--- 2311 Allow for specifying boot arguments to the kernel at 2312 build time. On some systems (e.g. embedded ones), it is 2313 necessary or convenient to provide some or all of the 2314 kernel boot arguments with the kernel itself (that is, 2315 to not rely on the boot loader to provide them.) 2316 2317 To compile command line arguments into the kernel, 2318 set this option to 'Y', then fill in the 2319 boot arguments in CONFIG_CMDLINE. 2320 2321 Systems with fully functional boot loaders (i.e. non-embedded) 2322 should leave this option set to 'N'. 2323 2324config CMDLINE 2325 string "Built-in kernel command string" 2326 depends on CMDLINE_BOOL 2327 default "" 2328 ---help--- 2329 Enter arguments here that should be compiled into the kernel 2330 image and used at boot time. If the boot loader provides a 2331 command line at boot time, it is appended to this string to 2332 form the full kernel command line, when the system boots. 2333 2334 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2335 change this behavior. 2336 2337 In most cases, the command line (whether built-in or provided 2338 by the boot loader) should specify the device for the root 2339 file system. 2340 2341config CMDLINE_OVERRIDE 2342 bool "Built-in command line overrides boot loader arguments" 2343 depends on CMDLINE_BOOL 2344 ---help--- 2345 Set this option to 'Y' to have the kernel ignore the boot loader 2346 command line, and use ONLY the built-in command line. 2347 2348 This is used to work around broken boot loaders. This should 2349 be set to 'N' under normal conditions. 2350 2351config MODIFY_LDT_SYSCALL 2352 bool "Enable the LDT (local descriptor table)" if EXPERT 2353 default y 2354 ---help--- 2355 Linux can allow user programs to install a per-process x86 2356 Local Descriptor Table (LDT) using the modify_ldt(2) system 2357 call. This is required to run 16-bit or segmented code such as 2358 DOSEMU or some Wine programs. It is also used by some very old 2359 threading libraries. 2360 2361 Enabling this feature adds a small amount of overhead to 2362 context switches and increases the low-level kernel attack 2363 surface. Disabling it removes the modify_ldt(2) system call. 2364 2365 Saying 'N' here may make sense for embedded or server kernels. 2366 2367source "kernel/livepatch/Kconfig" 2368 2369endmenu 2370 2371config ARCH_HAS_ADD_PAGES 2372 def_bool y 2373 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2374 2375config ARCH_ENABLE_MEMORY_HOTPLUG 2376 def_bool y 2377 depends on X86_64 || (X86_32 && HIGHMEM) 2378 2379config ARCH_ENABLE_MEMORY_HOTREMOVE 2380 def_bool y 2381 depends on MEMORY_HOTPLUG 2382 2383config USE_PERCPU_NUMA_NODE_ID 2384 def_bool y 2385 depends on NUMA 2386 2387config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2388 def_bool y 2389 depends on X86_64 || X86_PAE 2390 2391config ARCH_ENABLE_HUGEPAGE_MIGRATION 2392 def_bool y 2393 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2394 2395config ARCH_ENABLE_THP_MIGRATION 2396 def_bool y 2397 depends on X86_64 && TRANSPARENT_HUGEPAGE 2398 2399menu "Power management and ACPI options" 2400 2401config ARCH_HIBERNATION_HEADER 2402 def_bool y 2403 depends on X86_64 && HIBERNATION 2404 2405source "kernel/power/Kconfig" 2406 2407source "drivers/acpi/Kconfig" 2408 2409source "drivers/sfi/Kconfig" 2410 2411config X86_APM_BOOT 2412 def_bool y 2413 depends on APM 2414 2415menuconfig APM 2416 tristate "APM (Advanced Power Management) BIOS support" 2417 depends on X86_32 && PM_SLEEP 2418 ---help--- 2419 APM is a BIOS specification for saving power using several different 2420 techniques. This is mostly useful for battery powered laptops with 2421 APM compliant BIOSes. If you say Y here, the system time will be 2422 reset after a RESUME operation, the /proc/apm device will provide 2423 battery status information, and user-space programs will receive 2424 notification of APM "events" (e.g. battery status change). 2425 2426 If you select "Y" here, you can disable actual use of the APM 2427 BIOS by passing the "apm=off" option to the kernel at boot time. 2428 2429 Note that the APM support is almost completely disabled for 2430 machines with more than one CPU. 2431 2432 In order to use APM, you will need supporting software. For location 2433 and more information, read <file:Documentation/power/apm-acpi.txt> 2434 and the Battery Powered Linux mini-HOWTO, available from 2435 <http://www.tldp.org/docs.html#howto>. 2436 2437 This driver does not spin down disk drives (see the hdparm(8) 2438 manpage ("man 8 hdparm") for that), and it doesn't turn off 2439 VESA-compliant "green" monitors. 2440 2441 This driver does not support the TI 4000M TravelMate and the ACER 2442 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2443 desktop machines also don't have compliant BIOSes, and this driver 2444 may cause those machines to panic during the boot phase. 2445 2446 Generally, if you don't have a battery in your machine, there isn't 2447 much point in using this driver and you should say N. If you get 2448 random kernel OOPSes or reboots that don't seem to be related to 2449 anything, try disabling/enabling this option (or disabling/enabling 2450 APM in your BIOS). 2451 2452 Some other things you should try when experiencing seemingly random, 2453 "weird" problems: 2454 2455 1) make sure that you have enough swap space and that it is 2456 enabled. 2457 2) pass the "no-hlt" option to the kernel 2458 3) switch on floating point emulation in the kernel and pass 2459 the "no387" option to the kernel 2460 4) pass the "floppy=nodma" option to the kernel 2461 5) pass the "mem=4M" option to the kernel (thereby disabling 2462 all but the first 4 MB of RAM) 2463 6) make sure that the CPU is not over clocked. 2464 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2465 8) disable the cache from your BIOS settings 2466 9) install a fan for the video card or exchange video RAM 2467 10) install a better fan for the CPU 2468 11) exchange RAM chips 2469 12) exchange the motherboard. 2470 2471 To compile this driver as a module, choose M here: the 2472 module will be called apm. 2473 2474if APM 2475 2476config APM_IGNORE_USER_SUSPEND 2477 bool "Ignore USER SUSPEND" 2478 ---help--- 2479 This option will ignore USER SUSPEND requests. On machines with a 2480 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2481 series notebooks, it is necessary to say Y because of a BIOS bug. 2482 2483config APM_DO_ENABLE 2484 bool "Enable PM at boot time" 2485 ---help--- 2486 Enable APM features at boot time. From page 36 of the APM BIOS 2487 specification: "When disabled, the APM BIOS does not automatically 2488 power manage devices, enter the Standby State, enter the Suspend 2489 State, or take power saving steps in response to CPU Idle calls." 2490 This driver will make CPU Idle calls when Linux is idle (unless this 2491 feature is turned off -- see "Do CPU IDLE calls", below). This 2492 should always save battery power, but more complicated APM features 2493 will be dependent on your BIOS implementation. You may need to turn 2494 this option off if your computer hangs at boot time when using APM 2495 support, or if it beeps continuously instead of suspending. Turn 2496 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2497 T400CDT. This is off by default since most machines do fine without 2498 this feature. 2499 2500config APM_CPU_IDLE 2501 depends on CPU_IDLE 2502 bool "Make CPU Idle calls when idle" 2503 ---help--- 2504 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2505 On some machines, this can activate improved power savings, such as 2506 a slowed CPU clock rate, when the machine is idle. These idle calls 2507 are made after the idle loop has run for some length of time (e.g., 2508 333 mS). On some machines, this will cause a hang at boot time or 2509 whenever the CPU becomes idle. (On machines with more than one CPU, 2510 this option does nothing.) 2511 2512config APM_DISPLAY_BLANK 2513 bool "Enable console blanking using APM" 2514 ---help--- 2515 Enable console blanking using the APM. Some laptops can use this to 2516 turn off the LCD backlight when the screen blanker of the Linux 2517 virtual console blanks the screen. Note that this is only used by 2518 the virtual console screen blanker, and won't turn off the backlight 2519 when using the X Window system. This also doesn't have anything to 2520 do with your VESA-compliant power-saving monitor. Further, this 2521 option doesn't work for all laptops -- it might not turn off your 2522 backlight at all, or it might print a lot of errors to the console, 2523 especially if you are using gpm. 2524 2525config APM_ALLOW_INTS 2526 bool "Allow interrupts during APM BIOS calls" 2527 ---help--- 2528 Normally we disable external interrupts while we are making calls to 2529 the APM BIOS as a measure to lessen the effects of a badly behaving 2530 BIOS implementation. The BIOS should reenable interrupts if it 2531 needs to. Unfortunately, some BIOSes do not -- especially those in 2532 many of the newer IBM Thinkpads. If you experience hangs when you 2533 suspend, try setting this to Y. Otherwise, say N. 2534 2535endif # APM 2536 2537source "drivers/cpufreq/Kconfig" 2538 2539source "drivers/cpuidle/Kconfig" 2540 2541source "drivers/idle/Kconfig" 2542 2543endmenu 2544 2545 2546menu "Bus options (PCI etc.)" 2547 2548config PCI 2549 bool "PCI support" 2550 default y 2551 ---help--- 2552 Find out whether you have a PCI motherboard. PCI is the name of a 2553 bus system, i.e. the way the CPU talks to the other stuff inside 2554 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2555 VESA. If you have PCI, say Y, otherwise N. 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 def_bool y 2605 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2606 2607config PCI_OLPC 2608 def_bool y 2609 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2610 2611config PCI_XEN 2612 def_bool y 2613 depends on PCI && XEN 2614 select SWIOTLB_XEN 2615 2616config PCI_DOMAINS 2617 def_bool y 2618 depends on PCI 2619 2620config PCI_MMCONFIG 2621 bool "Support mmconfig PCI config space access" 2622 depends on X86_64 && PCI && ACPI 2623 2624config PCI_CNB20LE_QUIRK 2625 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2626 depends on PCI 2627 help 2628 Read the PCI windows out of the CNB20LE host bridge. This allows 2629 PCI hotplug to work on systems with the CNB20LE chipset which do 2630 not have ACPI. 2631 2632 There's no public spec for this chipset, and this functionality 2633 is known to be incomplete. 2634 2635 You should say N unless you know you need this. 2636 2637source "drivers/pci/Kconfig" 2638 2639config ISA_BUS 2640 bool "ISA-style bus support on modern systems" if EXPERT 2641 select ISA_BUS_API 2642 help 2643 Enables ISA-style drivers on modern systems. This is necessary to 2644 support PC/104 devices on X86_64 platforms. 2645 2646 If unsure, say N. 2647 2648# x86_64 have no ISA slots, but can have ISA-style DMA. 2649config ISA_DMA_API 2650 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2651 default y 2652 help 2653 Enables ISA-style DMA support for devices requiring such controllers. 2654 If unsure, say Y. 2655 2656if X86_32 2657 2658config ISA 2659 bool "ISA support" 2660 ---help--- 2661 Find out whether you have ISA slots on your motherboard. ISA is the 2662 name of a bus system, i.e. the way the CPU talks to the other stuff 2663 inside your box. Other bus systems are PCI, EISA, MicroChannel 2664 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2665 newer boards don't support it. If you have ISA, say Y, otherwise N. 2666 2667config EISA 2668 bool "EISA support" 2669 depends on ISA 2670 ---help--- 2671 The Extended Industry Standard Architecture (EISA) bus was 2672 developed as an open alternative to the IBM MicroChannel bus. 2673 2674 The EISA bus provided some of the features of the IBM MicroChannel 2675 bus while maintaining backward compatibility with cards made for 2676 the older ISA bus. The EISA bus saw limited use between 1988 and 2677 1995 when it was made obsolete by the PCI bus. 2678 2679 Say Y here if you are building a kernel for an EISA-based machine. 2680 2681 Otherwise, say N. 2682 2683source "drivers/eisa/Kconfig" 2684 2685config SCx200 2686 tristate "NatSemi SCx200 support" 2687 ---help--- 2688 This provides basic support for National Semiconductor's 2689 (now AMD's) Geode processors. The driver probes for the 2690 PCI-IDs of several on-chip devices, so its a good dependency 2691 for other scx200_* drivers. 2692 2693 If compiled as a module, the driver is named scx200. 2694 2695config SCx200HR_TIMER 2696 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2697 depends on SCx200 2698 default y 2699 ---help--- 2700 This driver provides a clocksource built upon the on-chip 2701 27MHz high-resolution timer. Its also a workaround for 2702 NSC Geode SC-1100's buggy TSC, which loses time when the 2703 processor goes idle (as is done by the scheduler). The 2704 other workaround is idle=poll boot option. 2705 2706config OLPC 2707 bool "One Laptop Per Child support" 2708 depends on !X86_PAE 2709 select GPIOLIB 2710 select OF 2711 select OF_PROMTREE 2712 select IRQ_DOMAIN 2713 ---help--- 2714 Add support for detecting the unique features of the OLPC 2715 XO hardware. 2716 2717config OLPC_XO1_PM 2718 bool "OLPC XO-1 Power Management" 2719 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2720 ---help--- 2721 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2722 2723config OLPC_XO1_RTC 2724 bool "OLPC XO-1 Real Time Clock" 2725 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2726 ---help--- 2727 Add support for the XO-1 real time clock, which can be used as a 2728 programmable wakeup source. 2729 2730config OLPC_XO1_SCI 2731 bool "OLPC XO-1 SCI extras" 2732 depends on OLPC && OLPC_XO1_PM 2733 depends on INPUT=y 2734 select POWER_SUPPLY 2735 select GPIO_CS5535 2736 select MFD_CORE 2737 ---help--- 2738 Add support for SCI-based features of the OLPC XO-1 laptop: 2739 - EC-driven system wakeups 2740 - Power button 2741 - Ebook switch 2742 - Lid switch 2743 - AC adapter status updates 2744 - Battery status updates 2745 2746config OLPC_XO15_SCI 2747 bool "OLPC XO-1.5 SCI extras" 2748 depends on OLPC && ACPI 2749 select POWER_SUPPLY 2750 ---help--- 2751 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2752 - EC-driven system wakeups 2753 - AC adapter status updates 2754 - Battery status updates 2755 2756config ALIX 2757 bool "PCEngines ALIX System Support (LED setup)" 2758 select GPIOLIB 2759 ---help--- 2760 This option enables system support for the PCEngines ALIX. 2761 At present this just sets up LEDs for GPIO control on 2762 ALIX2/3/6 boards. However, other system specific setup should 2763 get added here. 2764 2765 Note: You must still enable the drivers for GPIO and LED support 2766 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2767 2768 Note: You have to set alix.force=1 for boards with Award BIOS. 2769 2770config NET5501 2771 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2772 select GPIOLIB 2773 ---help--- 2774 This option enables system support for the Soekris Engineering net5501. 2775 2776config GEOS 2777 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2778 select GPIOLIB 2779 depends on DMI 2780 ---help--- 2781 This option enables system support for the Traverse Technologies GEOS. 2782 2783config TS5500 2784 bool "Technologic Systems TS-5500 platform support" 2785 depends on MELAN 2786 select CHECK_SIGNATURE 2787 select NEW_LEDS 2788 select LEDS_CLASS 2789 ---help--- 2790 This option enables system support for the Technologic Systems TS-5500. 2791 2792endif # X86_32 2793 2794config AMD_NB 2795 def_bool y 2796 depends on CPU_SUP_AMD && PCI 2797 2798source "drivers/pcmcia/Kconfig" 2799 2800config RAPIDIO 2801 tristate "RapidIO support" 2802 depends on PCI 2803 default n 2804 help 2805 If enabled this option will include drivers and the core 2806 infrastructure code to support RapidIO interconnect devices. 2807 2808source "drivers/rapidio/Kconfig" 2809 2810config X86_SYSFB 2811 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2812 help 2813 Firmwares often provide initial graphics framebuffers so the BIOS, 2814 bootloader or kernel can show basic video-output during boot for 2815 user-guidance and debugging. Historically, x86 used the VESA BIOS 2816 Extensions and EFI-framebuffers for this, which are mostly limited 2817 to x86. 2818 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2819 framebuffers so the new generic system-framebuffer drivers can be 2820 used on x86. If the framebuffer is not compatible with the generic 2821 modes, it is adverticed as fallback platform framebuffer so legacy 2822 drivers like efifb, vesafb and uvesafb can pick it up. 2823 If this option is not selected, all system framebuffers are always 2824 marked as fallback platform framebuffers as usual. 2825 2826 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2827 not be able to pick up generic system framebuffers if this option 2828 is selected. You are highly encouraged to enable simplefb as 2829 replacement if you select this option. simplefb can correctly deal 2830 with generic system framebuffers. But you should still keep vesafb 2831 and others enabled as fallback if a system framebuffer is 2832 incompatible with simplefb. 2833 2834 If unsure, say Y. 2835 2836endmenu 2837 2838 2839menu "Executable file formats / Emulations" 2840 2841source "fs/Kconfig.binfmt" 2842 2843config IA32_EMULATION 2844 bool "IA32 Emulation" 2845 depends on X86_64 2846 select ARCH_WANT_OLD_COMPAT_IPC 2847 select BINFMT_ELF 2848 select COMPAT_BINFMT_ELF 2849 select COMPAT_OLD_SIGACTION 2850 ---help--- 2851 Include code to run legacy 32-bit programs under a 2852 64-bit kernel. You should likely turn this on, unless you're 2853 100% sure that you don't have any 32-bit programs left. 2854 2855config IA32_AOUT 2856 tristate "IA32 a.out support" 2857 depends on IA32_EMULATION 2858 ---help--- 2859 Support old a.out binaries in the 32bit emulation. 2860 2861config X86_X32 2862 bool "x32 ABI for 64-bit mode" 2863 depends on X86_64 2864 ---help--- 2865 Include code to run binaries for the x32 native 32-bit ABI 2866 for 64-bit processors. An x32 process gets access to the 2867 full 64-bit register file and wide data path while leaving 2868 pointers at 32 bits for smaller memory footprint. 2869 2870 You will need a recent binutils (2.22 or later) with 2871 elf32_x86_64 support enabled to compile a kernel with this 2872 option set. 2873 2874config COMPAT_32 2875 def_bool y 2876 depends on IA32_EMULATION || X86_32 2877 select HAVE_UID16 2878 select OLD_SIGSUSPEND3 2879 2880config COMPAT 2881 def_bool y 2882 depends on IA32_EMULATION || X86_X32 2883 2884if COMPAT 2885config COMPAT_FOR_U64_ALIGNMENT 2886 def_bool y 2887 2888config SYSVIPC_COMPAT 2889 def_bool y 2890 depends on SYSVIPC 2891endif 2892 2893endmenu 2894 2895 2896config HAVE_ATOMIC_IOMAP 2897 def_bool y 2898 depends on X86_32 2899 2900config X86_DEV_DMA_OPS 2901 bool 2902 depends on X86_64 || STA2X11 2903 2904config X86_DMA_REMAP 2905 bool 2906 depends on STA2X11 2907 2908config HAVE_GENERIC_GUP 2909 def_bool y 2910 2911source "net/Kconfig" 2912 2913source "drivers/Kconfig" 2914 2915source "drivers/firmware/Kconfig" 2916 2917source "fs/Kconfig" 2918 2919source "arch/x86/Kconfig.debug" 2920 2921source "security/Kconfig" 2922 2923source "crypto/Kconfig" 2924 2925source "arch/x86/kvm/Kconfig" 2926 2927source "lib/Kconfig" 2928