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_PHYS_TO_DMA 58 select ARCH_HAS_MEMBARRIER_SYNC_CORE 59 select ARCH_HAS_PMEM_API if X86_64 60 select ARCH_HAS_REFCOUNT 61 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 62 select ARCH_HAS_SET_MEMORY 63 select ARCH_HAS_SG_CHAIN 64 select ARCH_HAS_STRICT_KERNEL_RWX 65 select ARCH_HAS_STRICT_MODULE_RWX 66 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 67 select ARCH_HAS_UBSAN_SANITIZE_ALL 68 select ARCH_HAS_ZONE_DEVICE if X86_64 69 select ARCH_HAVE_NMI_SAFE_CMPXCHG 70 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 71 select ARCH_MIGHT_HAVE_PC_PARPORT 72 select ARCH_MIGHT_HAVE_PC_SERIO 73 select ARCH_SUPPORTS_ATOMIC_RMW 74 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 75 select ARCH_USE_BUILTIN_BSWAP 76 select ARCH_USE_QUEUED_RWLOCKS 77 select ARCH_USE_QUEUED_SPINLOCKS 78 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 79 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 80 select ARCH_WANTS_THP_SWAP if X86_64 81 select BUILDTIME_EXTABLE_SORT 82 select CLKEVT_I8253 83 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 84 select CLOCKSOURCE_WATCHDOG 85 select DCACHE_WORD_ACCESS 86 select EDAC_ATOMIC_SCRUB 87 select EDAC_SUPPORT 88 select GENERIC_CLOCKEVENTS 89 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 90 select GENERIC_CLOCKEVENTS_MIN_ADJUST 91 select GENERIC_CMOS_UPDATE 92 select GENERIC_CPU_AUTOPROBE 93 select GENERIC_CPU_VULNERABILITIES 94 select GENERIC_EARLY_IOREMAP 95 select GENERIC_FIND_FIRST_BIT 96 select GENERIC_IOMAP 97 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 98 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 99 select GENERIC_IRQ_MIGRATION if SMP 100 select GENERIC_IRQ_PROBE 101 select GENERIC_IRQ_RESERVATION_MODE 102 select GENERIC_IRQ_SHOW 103 select GENERIC_PENDING_IRQ if SMP 104 select GENERIC_SMP_IDLE_THREAD 105 select GENERIC_STRNCPY_FROM_USER 106 select GENERIC_STRNLEN_USER 107 select GENERIC_TIME_VSYSCALL 108 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 109 select HAVE_ACPI_APEI if ACPI 110 select HAVE_ACPI_APEI_NMI if ACPI 111 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 112 select HAVE_ARCH_AUDITSYSCALL 113 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 114 select HAVE_ARCH_JUMP_LABEL 115 select HAVE_ARCH_KASAN if X86_64 116 select HAVE_ARCH_KGDB 117 select HAVE_ARCH_MMAP_RND_BITS if MMU 118 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 119 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 120 select HAVE_ARCH_SECCOMP_FILTER 121 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 122 select HAVE_ARCH_TRACEHOOK 123 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 124 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 125 select HAVE_ARCH_VMAP_STACK if X86_64 126 select HAVE_ARCH_WITHIN_STACK_FRAMES 127 select HAVE_CC_STACKPROTECTOR 128 select HAVE_CMPXCHG_DOUBLE 129 select HAVE_CMPXCHG_LOCAL 130 select HAVE_CONTEXT_TRACKING if X86_64 131 select HAVE_COPY_THREAD_TLS 132 select HAVE_C_RECORDMCOUNT 133 select HAVE_DEBUG_KMEMLEAK 134 select HAVE_DEBUG_STACKOVERFLOW 135 select HAVE_DMA_API_DEBUG 136 select HAVE_DMA_CONTIGUOUS 137 select HAVE_DYNAMIC_FTRACE 138 select HAVE_DYNAMIC_FTRACE_WITH_REGS 139 select HAVE_EBPF_JIT if X86_64 140 select HAVE_EFFICIENT_UNALIGNED_ACCESS 141 select HAVE_EXIT_THREAD 142 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 143 select HAVE_FTRACE_MCOUNT_RECORD 144 select HAVE_FUNCTION_GRAPH_TRACER 145 select HAVE_FUNCTION_TRACER 146 select HAVE_GCC_PLUGINS 147 select HAVE_HW_BREAKPOINT 148 select HAVE_IDE 149 select HAVE_IOREMAP_PROT 150 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 151 select HAVE_IRQ_TIME_ACCOUNTING 152 select HAVE_KERNEL_BZIP2 153 select HAVE_KERNEL_GZIP 154 select HAVE_KERNEL_LZ4 155 select HAVE_KERNEL_LZMA 156 select HAVE_KERNEL_LZO 157 select HAVE_KERNEL_XZ 158 select HAVE_KPROBES 159 select HAVE_KPROBES_ON_FTRACE 160 select HAVE_FUNCTION_ERROR_INJECTION 161 select HAVE_KRETPROBES 162 select HAVE_KVM 163 select HAVE_LIVEPATCH if X86_64 164 select HAVE_MEMBLOCK 165 select HAVE_MEMBLOCK_NODE_MAP 166 select HAVE_MIXED_BREAKPOINTS_REGS 167 select HAVE_MOD_ARCH_SPECIFIC 168 select HAVE_NMI 169 select HAVE_OPROFILE 170 select HAVE_OPTPROBES 171 select HAVE_PCSPKR_PLATFORM 172 select HAVE_PERF_EVENTS 173 select HAVE_PERF_EVENTS_NMI 174 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 175 select HAVE_PERF_REGS 176 select HAVE_PERF_USER_STACK_DUMP 177 select HAVE_RCU_TABLE_FREE 178 select HAVE_REGS_AND_STACK_ACCESS_API 179 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 180 select HAVE_STACK_VALIDATION if X86_64 181 select HAVE_SYSCALL_TRACEPOINTS 182 select HAVE_UNSTABLE_SCHED_CLOCK 183 select HAVE_USER_RETURN_NOTIFIER 184 select IRQ_FORCED_THREADING 185 select PCI_LOCKLESS_CONFIG 186 select PERF_EVENTS 187 select RTC_LIB 188 select RTC_MC146818_LIB 189 select SPARSE_IRQ 190 select SRCU 191 select SYSCTL_EXCEPTION_TRACE 192 select THREAD_INFO_IN_TASK 193 select USER_STACKTRACE_SUPPORT 194 select VIRT_TO_BUS 195 select X86_FEATURE_NAMES if PROC_FS 196 197config INSTRUCTION_DECODER 198 def_bool y 199 depends on KPROBES || PERF_EVENTS || UPROBES 200 201config OUTPUT_FORMAT 202 string 203 default "elf32-i386" if X86_32 204 default "elf64-x86-64" if X86_64 205 206config ARCH_DEFCONFIG 207 string 208 default "arch/x86/configs/i386_defconfig" if X86_32 209 default "arch/x86/configs/x86_64_defconfig" if X86_64 210 211config LOCKDEP_SUPPORT 212 def_bool y 213 214config STACKTRACE_SUPPORT 215 def_bool y 216 217config MMU 218 def_bool y 219 220config ARCH_MMAP_RND_BITS_MIN 221 default 28 if 64BIT 222 default 8 223 224config ARCH_MMAP_RND_BITS_MAX 225 default 32 if 64BIT 226 default 16 227 228config ARCH_MMAP_RND_COMPAT_BITS_MIN 229 default 8 230 231config ARCH_MMAP_RND_COMPAT_BITS_MAX 232 default 16 233 234config SBUS 235 bool 236 237config NEED_DMA_MAP_STATE 238 def_bool y 239 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 240 241config NEED_SG_DMA_LENGTH 242 def_bool y 243 244config GENERIC_ISA_DMA 245 def_bool y 246 depends on ISA_DMA_API 247 248config GENERIC_BUG 249 def_bool y 250 depends on BUG 251 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 252 253config GENERIC_BUG_RELATIVE_POINTERS 254 bool 255 256config GENERIC_HWEIGHT 257 def_bool y 258 259config ARCH_MAY_HAVE_PC_FDC 260 def_bool y 261 depends on ISA_DMA_API 262 263config RWSEM_XCHGADD_ALGORITHM 264 def_bool y 265 266config GENERIC_CALIBRATE_DELAY 267 def_bool y 268 269config ARCH_HAS_CPU_RELAX 270 def_bool y 271 272config ARCH_HAS_CACHE_LINE_SIZE 273 def_bool y 274 275config HAVE_SETUP_PER_CPU_AREA 276 def_bool y 277 278config NEED_PER_CPU_EMBED_FIRST_CHUNK 279 def_bool y 280 281config NEED_PER_CPU_PAGE_FIRST_CHUNK 282 def_bool y 283 284config ARCH_HIBERNATION_POSSIBLE 285 def_bool y 286 287config ARCH_SUSPEND_POSSIBLE 288 def_bool y 289 290config ARCH_WANT_HUGE_PMD_SHARE 291 def_bool y 292 293config ARCH_WANT_GENERAL_HUGETLB 294 def_bool y 295 296config ZONE_DMA32 297 def_bool y if X86_64 298 299config AUDIT_ARCH 300 def_bool y if X86_64 301 302config ARCH_SUPPORTS_OPTIMIZED_INLINING 303 def_bool y 304 305config ARCH_SUPPORTS_DEBUG_PAGEALLOC 306 def_bool y 307 308config KASAN_SHADOW_OFFSET 309 hex 310 depends on KASAN 311 default 0xdffffc0000000000 312 313config HAVE_INTEL_TXT 314 def_bool y 315 depends on INTEL_IOMMU && ACPI 316 317config X86_32_SMP 318 def_bool y 319 depends on X86_32 && SMP 320 321config X86_64_SMP 322 def_bool y 323 depends on X86_64 && SMP 324 325config X86_32_LAZY_GS 326 def_bool y 327 depends on X86_32 && CC_STACKPROTECTOR_NONE 328 329config ARCH_SUPPORTS_UPROBES 330 def_bool y 331 332config FIX_EARLYCON_MEM 333 def_bool y 334 335config PGTABLE_LEVELS 336 int 337 default 5 if X86_5LEVEL 338 default 4 if X86_64 339 default 3 if X86_PAE 340 default 2 341 342source "init/Kconfig" 343source "kernel/Kconfig.freezer" 344 345menu "Processor type and features" 346 347config ZONE_DMA 348 bool "DMA memory allocation support" if EXPERT 349 default y 350 help 351 DMA memory allocation support allows devices with less than 32-bit 352 addressing to allocate within the first 16MB of address space. 353 Disable if no such devices will be used. 354 355 If unsure, say Y. 356 357config SMP 358 bool "Symmetric multi-processing support" 359 ---help--- 360 This enables support for systems with more than one CPU. If you have 361 a system with only one CPU, say N. If you have a system with more 362 than one CPU, say Y. 363 364 If you say N here, the kernel will run on uni- and multiprocessor 365 machines, but will use only one CPU of a multiprocessor machine. If 366 you say Y here, the kernel will run on many, but not all, 367 uniprocessor machines. On a uniprocessor machine, the kernel 368 will run faster if you say N here. 369 370 Note that if you say Y here and choose architecture "586" or 371 "Pentium" under "Processor family", the kernel will not work on 486 372 architectures. Similarly, multiprocessor kernels for the "PPro" 373 architecture may not work on all Pentium based boards. 374 375 People using multiprocessor machines who say Y here should also say 376 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 377 Management" code will be disabled if you say Y here. 378 379 See also <file:Documentation/x86/i386/IO-APIC.txt>, 380 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 381 <http://www.tldp.org/docs.html#howto>. 382 383 If you don't know what to do here, say N. 384 385config X86_FEATURE_NAMES 386 bool "Processor feature human-readable names" if EMBEDDED 387 default y 388 ---help--- 389 This option compiles in a table of x86 feature bits and corresponding 390 names. This is required to support /proc/cpuinfo and a few kernel 391 messages. You can disable this to save space, at the expense of 392 making those few kernel messages show numeric feature bits instead. 393 394 If in doubt, say Y. 395 396config X86_FAST_FEATURE_TESTS 397 bool "Fast CPU feature tests" if EMBEDDED 398 default y 399 ---help--- 400 Some fast-paths in the kernel depend on the capabilities of the CPU. 401 Say Y here for the kernel to patch in the appropriate code at runtime 402 based on the capabilities of the CPU. The infrastructure for patching 403 code at runtime takes up some additional space; space-constrained 404 embedded systems may wish to say N here to produce smaller, slightly 405 slower code. 406 407config X86_X2APIC 408 bool "Support x2apic" 409 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 410 ---help--- 411 This enables x2apic support on CPUs that have this feature. 412 413 This allows 32-bit apic IDs (so it can support very large systems), 414 and accesses the local apic via MSRs not via mmio. 415 416 If you don't know what to do here, say N. 417 418config X86_MPPARSE 419 bool "Enable MPS table" if ACPI || SFI 420 default y 421 depends on X86_LOCAL_APIC 422 ---help--- 423 For old smp systems that do not have proper acpi support. Newer systems 424 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 425 426config GOLDFISH 427 def_bool y 428 depends on X86_GOLDFISH 429 430config RETPOLINE 431 bool "Avoid speculative indirect branches in kernel" 432 default y 433 select STACK_VALIDATION if HAVE_STACK_VALIDATION 434 help 435 Compile kernel with the retpoline compiler options to guard against 436 kernel-to-user data leaks by avoiding speculative indirect 437 branches. Requires a compiler with -mindirect-branch=thunk-extern 438 support for full protection. The kernel may run slower. 439 440 Without compiler support, at least indirect branches in assembler 441 code are eliminated. Since this includes the syscall entry path, 442 it is not entirely pointless. 443 444config INTEL_RDT 445 bool "Intel Resource Director Technology support" 446 default n 447 depends on X86 && CPU_SUP_INTEL 448 select KERNFS 449 help 450 Select to enable resource allocation and monitoring which are 451 sub-features of Intel Resource Director Technology(RDT). More 452 information about RDT can be found in the Intel x86 453 Architecture Software Developer Manual. 454 455 Say N if unsure. 456 457if X86_32 458config X86_BIGSMP 459 bool "Support for big SMP systems with more than 8 CPUs" 460 depends on SMP 461 ---help--- 462 This option is needed for the systems that have more than 8 CPUs 463 464config X86_EXTENDED_PLATFORM 465 bool "Support for extended (non-PC) x86 platforms" 466 default y 467 ---help--- 468 If you disable this option then the kernel will only support 469 standard PC platforms. (which covers the vast majority of 470 systems out there.) 471 472 If you enable this option then you'll be able to select support 473 for the following (non-PC) 32 bit x86 platforms: 474 Goldfish (Android emulator) 475 AMD Elan 476 RDC R-321x SoC 477 SGI 320/540 (Visual Workstation) 478 STA2X11-based (e.g. Northville) 479 Moorestown MID devices 480 481 If you have one of these systems, or if you want to build a 482 generic distribution kernel, say Y here - otherwise say N. 483endif 484 485if X86_64 486config X86_EXTENDED_PLATFORM 487 bool "Support for extended (non-PC) x86 platforms" 488 default y 489 ---help--- 490 If you disable this option then the kernel will only support 491 standard PC platforms. (which covers the vast majority of 492 systems out there.) 493 494 If you enable this option then you'll be able to select support 495 for the following (non-PC) 64 bit x86 platforms: 496 Numascale NumaChip 497 ScaleMP vSMP 498 SGI Ultraviolet 499 500 If you have one of these systems, or if you want to build a 501 generic distribution kernel, say Y here - otherwise say N. 502endif 503# This is an alphabetically sorted list of 64 bit extended platforms 504# Please maintain the alphabetic order if and when there are additions 505config X86_NUMACHIP 506 bool "Numascale NumaChip" 507 depends on X86_64 508 depends on X86_EXTENDED_PLATFORM 509 depends on NUMA 510 depends on SMP 511 depends on X86_X2APIC 512 depends on PCI_MMCONFIG 513 ---help--- 514 Adds support for Numascale NumaChip large-SMP systems. Needed to 515 enable more than ~168 cores. 516 If you don't have one of these, you should say N here. 517 518config X86_VSMP 519 bool "ScaleMP vSMP" 520 select HYPERVISOR_GUEST 521 select PARAVIRT 522 depends on X86_64 && PCI 523 depends on X86_EXTENDED_PLATFORM 524 depends on SMP 525 ---help--- 526 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 527 supposed to run on these EM64T-based machines. Only choose this option 528 if you have one of these machines. 529 530config X86_UV 531 bool "SGI Ultraviolet" 532 depends on X86_64 533 depends on X86_EXTENDED_PLATFORM 534 depends on NUMA 535 depends on EFI 536 depends on X86_X2APIC 537 depends on PCI 538 ---help--- 539 This option is needed in order to support SGI Ultraviolet systems. 540 If you don't have one of these, you should say N here. 541 542# Following is an alphabetically sorted list of 32 bit extended platforms 543# Please maintain the alphabetic order if and when there are additions 544 545config X86_GOLDFISH 546 bool "Goldfish (Virtual Platform)" 547 depends on X86_EXTENDED_PLATFORM 548 ---help--- 549 Enable support for the Goldfish virtual platform used primarily 550 for Android development. Unless you are building for the Android 551 Goldfish emulator say N here. 552 553config X86_INTEL_CE 554 bool "CE4100 TV platform" 555 depends on PCI 556 depends on PCI_GODIRECT 557 depends on X86_IO_APIC 558 depends on X86_32 559 depends on X86_EXTENDED_PLATFORM 560 select X86_REBOOTFIXUPS 561 select OF 562 select OF_EARLY_FLATTREE 563 ---help--- 564 Select for the Intel CE media processor (CE4100) SOC. 565 This option compiles in support for the CE4100 SOC for settop 566 boxes and media devices. 567 568config X86_INTEL_MID 569 bool "Intel MID platform support" 570 depends on X86_EXTENDED_PLATFORM 571 depends on X86_PLATFORM_DEVICES 572 depends on PCI 573 depends on X86_64 || (PCI_GOANY && X86_32) 574 depends on X86_IO_APIC 575 select SFI 576 select I2C 577 select DW_APB_TIMER 578 select APB_TIMER 579 select INTEL_SCU_IPC 580 select MFD_INTEL_MSIC 581 ---help--- 582 Select to build a kernel capable of supporting Intel MID (Mobile 583 Internet Device) platform systems which do not have the PCI legacy 584 interfaces. If you are building for a PC class system say N here. 585 586 Intel MID platforms are based on an Intel processor and chipset which 587 consume less power than most of the x86 derivatives. 588 589config X86_INTEL_QUARK 590 bool "Intel Quark platform support" 591 depends on X86_32 592 depends on X86_EXTENDED_PLATFORM 593 depends on X86_PLATFORM_DEVICES 594 depends on X86_TSC 595 depends on PCI 596 depends on PCI_GOANY 597 depends on X86_IO_APIC 598 select IOSF_MBI 599 select INTEL_IMR 600 select COMMON_CLK 601 ---help--- 602 Select to include support for Quark X1000 SoC. 603 Say Y here if you have a Quark based system such as the Arduino 604 compatible Intel Galileo. 605 606config X86_INTEL_LPSS 607 bool "Intel Low Power Subsystem Support" 608 depends on X86 && ACPI 609 select COMMON_CLK 610 select PINCTRL 611 select IOSF_MBI 612 ---help--- 613 Select to build support for Intel Low Power Subsystem such as 614 found on Intel Lynxpoint PCH. Selecting this option enables 615 things like clock tree (common clock framework) and pincontrol 616 which are needed by the LPSS peripheral drivers. 617 618config X86_AMD_PLATFORM_DEVICE 619 bool "AMD ACPI2Platform devices support" 620 depends on ACPI 621 select COMMON_CLK 622 select PINCTRL 623 ---help--- 624 Select to interpret AMD specific ACPI device to platform device 625 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 626 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 627 implemented under PINCTRL subsystem. 628 629config IOSF_MBI 630 tristate "Intel SoC IOSF Sideband support for SoC platforms" 631 depends on PCI 632 ---help--- 633 This option enables sideband register access support for Intel SoC 634 platforms. On these platforms the IOSF sideband is used in lieu of 635 MSR's for some register accesses, mostly but not limited to thermal 636 and power. Drivers may query the availability of this device to 637 determine if they need the sideband in order to work on these 638 platforms. The sideband is available on the following SoC products. 639 This list is not meant to be exclusive. 640 - BayTrail 641 - Braswell 642 - Quark 643 644 You should say Y if you are running a kernel on one of these SoC's. 645 646config IOSF_MBI_DEBUG 647 bool "Enable IOSF sideband access through debugfs" 648 depends on IOSF_MBI && DEBUG_FS 649 ---help--- 650 Select this option to expose the IOSF sideband access registers (MCR, 651 MDR, MCRX) through debugfs to write and read register information from 652 different units on the SoC. This is most useful for obtaining device 653 state information for debug and analysis. As this is a general access 654 mechanism, users of this option would have specific knowledge of the 655 device they want to access. 656 657 If you don't require the option or are in doubt, say N. 658 659config X86_RDC321X 660 bool "RDC R-321x SoC" 661 depends on X86_32 662 depends on X86_EXTENDED_PLATFORM 663 select M486 664 select X86_REBOOTFIXUPS 665 ---help--- 666 This option is needed for RDC R-321x system-on-chip, also known 667 as R-8610-(G). 668 If you don't have one of these chips, you should say N here. 669 670config X86_32_NON_STANDARD 671 bool "Support non-standard 32-bit SMP architectures" 672 depends on X86_32 && SMP 673 depends on X86_EXTENDED_PLATFORM 674 ---help--- 675 This option compiles in the bigsmp and STA2X11 default 676 subarchitectures. It is intended for a generic binary 677 kernel. If you select them all, kernel will probe it one by 678 one and will fallback to default. 679 680# Alphabetically sorted list of Non standard 32 bit platforms 681 682config X86_SUPPORTS_MEMORY_FAILURE 683 def_bool y 684 # MCE code calls memory_failure(): 685 depends on X86_MCE 686 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 687 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 688 depends on X86_64 || !SPARSEMEM 689 select ARCH_SUPPORTS_MEMORY_FAILURE 690 691config STA2X11 692 bool "STA2X11 Companion Chip Support" 693 depends on X86_32_NON_STANDARD && PCI 694 select X86_DEV_DMA_OPS 695 select X86_DMA_REMAP 696 select SWIOTLB 697 select MFD_STA2X11 698 select GPIOLIB 699 default n 700 ---help--- 701 This adds support for boards based on the STA2X11 IO-Hub, 702 a.k.a. "ConneXt". The chip is used in place of the standard 703 PC chipset, so all "standard" peripherals are missing. If this 704 option is selected the kernel will still be able to boot on 705 standard PC machines. 706 707config X86_32_IRIS 708 tristate "Eurobraille/Iris poweroff module" 709 depends on X86_32 710 ---help--- 711 The Iris machines from EuroBraille do not have APM or ACPI support 712 to shut themselves down properly. A special I/O sequence is 713 needed to do so, which is what this module does at 714 kernel shutdown. 715 716 This is only for Iris machines from EuroBraille. 717 718 If unused, say N. 719 720config SCHED_OMIT_FRAME_POINTER 721 def_bool y 722 prompt "Single-depth WCHAN output" 723 depends on X86 724 ---help--- 725 Calculate simpler /proc/<PID>/wchan values. If this option 726 is disabled then wchan values will recurse back to the 727 caller function. This provides more accurate wchan values, 728 at the expense of slightly more scheduling overhead. 729 730 If in doubt, say "Y". 731 732menuconfig HYPERVISOR_GUEST 733 bool "Linux guest support" 734 ---help--- 735 Say Y here to enable options for running Linux under various hyper- 736 visors. This option enables basic hypervisor detection and platform 737 setup. 738 739 If you say N, all options in this submenu will be skipped and 740 disabled, and Linux guest support won't be built in. 741 742if HYPERVISOR_GUEST 743 744config PARAVIRT 745 bool "Enable paravirtualization code" 746 ---help--- 747 This changes the kernel so it can modify itself when it is run 748 under a hypervisor, potentially improving performance significantly 749 over full virtualization. However, when run without a hypervisor 750 the kernel is theoretically slower and slightly larger. 751 752config PARAVIRT_DEBUG 753 bool "paravirt-ops debugging" 754 depends on PARAVIRT && DEBUG_KERNEL 755 ---help--- 756 Enable to debug paravirt_ops internals. Specifically, BUG if 757 a paravirt_op is missing when it is called. 758 759config PARAVIRT_SPINLOCKS 760 bool "Paravirtualization layer for spinlocks" 761 depends on PARAVIRT && SMP 762 ---help--- 763 Paravirtualized spinlocks allow a pvops backend to replace the 764 spinlock implementation with something virtualization-friendly 765 (for example, block the virtual CPU rather than spinning). 766 767 It has a minimal impact on native kernels and gives a nice performance 768 benefit on paravirtualized KVM / Xen kernels. 769 770 If you are unsure how to answer this question, answer Y. 771 772config QUEUED_LOCK_STAT 773 bool "Paravirt queued spinlock statistics" 774 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 775 ---help--- 776 Enable the collection of statistical data on the slowpath 777 behavior of paravirtualized queued spinlocks and report 778 them on debugfs. 779 780source "arch/x86/xen/Kconfig" 781 782config KVM_GUEST 783 bool "KVM Guest support (including kvmclock)" 784 depends on PARAVIRT 785 select PARAVIRT_CLOCK 786 default y 787 ---help--- 788 This option enables various optimizations for running under the KVM 789 hypervisor. It includes a paravirtualized clock, so that instead 790 of relying on a PIT (or probably other) emulation by the 791 underlying device model, the host provides the guest with 792 timing infrastructure such as time of day, and system time 793 794config KVM_DEBUG_FS 795 bool "Enable debug information for KVM Guests in debugfs" 796 depends on KVM_GUEST && DEBUG_FS 797 default n 798 ---help--- 799 This option enables collection of various statistics for KVM guest. 800 Statistics are displayed in debugfs filesystem. Enabling this option 801 may incur significant overhead. 802 803config PARAVIRT_TIME_ACCOUNTING 804 bool "Paravirtual steal time accounting" 805 depends on PARAVIRT 806 default n 807 ---help--- 808 Select this option to enable fine granularity task steal time 809 accounting. Time spent executing other tasks in parallel with 810 the current vCPU is discounted from the vCPU power. To account for 811 that, there can be a small performance impact. 812 813 If in doubt, say N here. 814 815config PARAVIRT_CLOCK 816 bool 817 818config JAILHOUSE_GUEST 819 bool "Jailhouse non-root cell support" 820 depends on X86_64 && PCI 821 select X86_PM_TIMER 822 ---help--- 823 This option allows to run Linux as guest in a Jailhouse non-root 824 cell. You can leave this option disabled if you only want to start 825 Jailhouse and run Linux afterwards in the root cell. 826 827endif #HYPERVISOR_GUEST 828 829config NO_BOOTMEM 830 def_bool y 831 832source "arch/x86/Kconfig.cpu" 833 834config HPET_TIMER 835 def_bool X86_64 836 prompt "HPET Timer Support" if X86_32 837 ---help--- 838 Use the IA-PC HPET (High Precision Event Timer) to manage 839 time in preference to the PIT and RTC, if a HPET is 840 present. 841 HPET is the next generation timer replacing legacy 8254s. 842 The HPET provides a stable time base on SMP 843 systems, unlike the TSC, but it is more expensive to access, 844 as it is off-chip. The interface used is documented 845 in the HPET spec, revision 1. 846 847 You can safely choose Y here. However, HPET will only be 848 activated if the platform and the BIOS support this feature. 849 Otherwise the 8254 will be used for timing services. 850 851 Choose N to continue using the legacy 8254 timer. 852 853config HPET_EMULATE_RTC 854 def_bool y 855 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 856 857config APB_TIMER 858 def_bool y if X86_INTEL_MID 859 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 860 select DW_APB_TIMER 861 depends on X86_INTEL_MID && SFI 862 help 863 APB timer is the replacement for 8254, HPET on X86 MID platforms. 864 The APBT provides a stable time base on SMP 865 systems, unlike the TSC, but it is more expensive to access, 866 as it is off-chip. APB timers are always running regardless of CPU 867 C states, they are used as per CPU clockevent device when possible. 868 869# Mark as expert because too many people got it wrong. 870# The code disables itself when not needed. 871config DMI 872 default y 873 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 874 bool "Enable DMI scanning" if EXPERT 875 ---help--- 876 Enabled scanning of DMI to identify machine quirks. Say Y 877 here unless you have verified that your setup is not 878 affected by entries in the DMI blacklist. Required by PNP 879 BIOS code. 880 881config GART_IOMMU 882 bool "Old AMD GART IOMMU support" 883 select SWIOTLB 884 depends on X86_64 && PCI && AMD_NB 885 ---help--- 886 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 887 GART based hardware IOMMUs. 888 889 The GART supports full DMA access for devices with 32-bit access 890 limitations, on systems with more than 3 GB. This is usually needed 891 for USB, sound, many IDE/SATA chipsets and some other devices. 892 893 Newer systems typically have a modern AMD IOMMU, supported via 894 the CONFIG_AMD_IOMMU=y config option. 895 896 In normal configurations this driver is only active when needed: 897 there's more than 3 GB of memory and the system contains a 898 32-bit limited device. 899 900 If unsure, say Y. 901 902config CALGARY_IOMMU 903 bool "IBM Calgary IOMMU support" 904 select SWIOTLB 905 depends on X86_64 && PCI 906 ---help--- 907 Support for hardware IOMMUs in IBM's xSeries x366 and x460 908 systems. Needed to run systems with more than 3GB of memory 909 properly with 32-bit PCI devices that do not support DAC 910 (Double Address Cycle). Calgary also supports bus level 911 isolation, where all DMAs pass through the IOMMU. This 912 prevents them from going anywhere except their intended 913 destination. This catches hard-to-find kernel bugs and 914 mis-behaving drivers and devices that do not use the DMA-API 915 properly to set up their DMA buffers. The IOMMU can be 916 turned off at boot time with the iommu=off parameter. 917 Normally the kernel will make the right choice by itself. 918 If unsure, say Y. 919 920config CALGARY_IOMMU_ENABLED_BY_DEFAULT 921 def_bool y 922 prompt "Should Calgary be enabled by default?" 923 depends on CALGARY_IOMMU 924 ---help--- 925 Should Calgary be enabled by default? if you choose 'y', Calgary 926 will be used (if it exists). If you choose 'n', Calgary will not be 927 used even if it exists. If you choose 'n' and would like to use 928 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 929 If unsure, say Y. 930 931# need this always selected by IOMMU for the VIA workaround 932config SWIOTLB 933 def_bool y if X86_64 934 ---help--- 935 Support for software bounce buffers used on x86-64 systems 936 which don't have a hardware IOMMU. Using this PCI devices 937 which can only access 32-bits of memory can be used on systems 938 with more than 3 GB of memory. 939 If unsure, say Y. 940 941config IOMMU_HELPER 942 def_bool y 943 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 944 945config MAXSMP 946 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 947 depends on X86_64 && SMP && DEBUG_KERNEL 948 select CPUMASK_OFFSTACK 949 ---help--- 950 Enable maximum number of CPUS and NUMA Nodes for this architecture. 951 If unsure, say N. 952 953# 954# The maximum number of CPUs supported: 955# 956# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 957# and which can be configured interactively in the 958# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 959# 960# The ranges are different on 32-bit and 64-bit kernels, depending on 961# hardware capabilities and scalability features of the kernel. 962# 963# ( If MAXSMP is enabled we just use the highest possible value and disable 964# interactive configuration. ) 965# 966 967config NR_CPUS_RANGE_BEGIN 968 int 969 default NR_CPUS_RANGE_END if MAXSMP 970 default 1 if !SMP 971 default 2 972 973config NR_CPUS_RANGE_END 974 int 975 depends on X86_32 976 default 64 if SMP && X86_BIGSMP 977 default 8 if SMP && !X86_BIGSMP 978 default 1 if !SMP 979 980config NR_CPUS_RANGE_END 981 int 982 depends on X86_64 983 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 984 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 985 default 1 if !SMP 986 987config NR_CPUS_DEFAULT 988 int 989 depends on X86_32 990 default 32 if X86_BIGSMP 991 default 8 if SMP 992 default 1 if !SMP 993 994config NR_CPUS_DEFAULT 995 int 996 depends on X86_64 997 default 8192 if MAXSMP 998 default 64 if SMP 999 default 1 if !SMP 1000 1001config NR_CPUS 1002 int "Maximum number of CPUs" if SMP && !MAXSMP 1003 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1004 default NR_CPUS_DEFAULT 1005 ---help--- 1006 This allows you to specify the maximum number of CPUs which this 1007 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1008 supported value is 8192, otherwise the maximum value is 512. The 1009 minimum value which makes sense is 2. 1010 1011 This is purely to save memory: each supported CPU adds about 8KB 1012 to the kernel image. 1013 1014config SCHED_SMT 1015 bool "SMT (Hyperthreading) scheduler support" 1016 depends on SMP 1017 ---help--- 1018 SMT scheduler support improves the CPU scheduler's decision making 1019 when dealing with Intel Pentium 4 chips with HyperThreading at a 1020 cost of slightly increased overhead in some places. If unsure say 1021 N here. 1022 1023config SCHED_MC 1024 def_bool y 1025 prompt "Multi-core scheduler support" 1026 depends on SMP 1027 ---help--- 1028 Multi-core scheduler support improves the CPU scheduler's decision 1029 making when dealing with multi-core CPU chips at a cost of slightly 1030 increased overhead in some places. If unsure say N here. 1031 1032config SCHED_MC_PRIO 1033 bool "CPU core priorities scheduler support" 1034 depends on SCHED_MC && CPU_SUP_INTEL 1035 select X86_INTEL_PSTATE 1036 select CPU_FREQ 1037 default y 1038 ---help--- 1039 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1040 core ordering determined at manufacturing time, which allows 1041 certain cores to reach higher turbo frequencies (when running 1042 single threaded workloads) than others. 1043 1044 Enabling this kernel feature teaches the scheduler about 1045 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1046 scheduler's CPU selection logic accordingly, so that higher 1047 overall system performance can be achieved. 1048 1049 This feature will have no effect on CPUs without this feature. 1050 1051 If unsure say Y here. 1052 1053source "kernel/Kconfig.preempt" 1054 1055config UP_LATE_INIT 1056 def_bool y 1057 depends on !SMP && X86_LOCAL_APIC 1058 1059config X86_UP_APIC 1060 bool "Local APIC support on uniprocessors" if !PCI_MSI 1061 default PCI_MSI 1062 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1063 ---help--- 1064 A local APIC (Advanced Programmable Interrupt Controller) is an 1065 integrated interrupt controller in the CPU. If you have a single-CPU 1066 system which has a processor with a local APIC, you can say Y here to 1067 enable and use it. If you say Y here even though your machine doesn't 1068 have a local APIC, then the kernel will still run with no slowdown at 1069 all. The local APIC supports CPU-generated self-interrupts (timer, 1070 performance counters), and the NMI watchdog which detects hard 1071 lockups. 1072 1073config X86_UP_IOAPIC 1074 bool "IO-APIC support on uniprocessors" 1075 depends on X86_UP_APIC 1076 ---help--- 1077 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1078 SMP-capable replacement for PC-style interrupt controllers. Most 1079 SMP systems and many recent uniprocessor systems have one. 1080 1081 If you have a single-CPU system with an IO-APIC, you can say Y here 1082 to use it. If you say Y here even though your machine doesn't have 1083 an IO-APIC, then the kernel will still run with no slowdown at all. 1084 1085config X86_LOCAL_APIC 1086 def_bool y 1087 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1088 select IRQ_DOMAIN_HIERARCHY 1089 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1090 1091config X86_IO_APIC 1092 def_bool y 1093 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1094 1095config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1096 bool "Reroute for broken boot IRQs" 1097 depends on X86_IO_APIC 1098 ---help--- 1099 This option enables a workaround that fixes a source of 1100 spurious interrupts. This is recommended when threaded 1101 interrupt handling is used on systems where the generation of 1102 superfluous "boot interrupts" cannot be disabled. 1103 1104 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1105 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1106 kernel does during interrupt handling). On chipsets where this 1107 boot IRQ generation cannot be disabled, this workaround keeps 1108 the original IRQ line masked so that only the equivalent "boot 1109 IRQ" is delivered to the CPUs. The workaround also tells the 1110 kernel to set up the IRQ handler on the boot IRQ line. In this 1111 way only one interrupt is delivered to the kernel. Otherwise 1112 the spurious second interrupt may cause the kernel to bring 1113 down (vital) interrupt lines. 1114 1115 Only affects "broken" chipsets. Interrupt sharing may be 1116 increased on these systems. 1117 1118config X86_MCE 1119 bool "Machine Check / overheating reporting" 1120 select GENERIC_ALLOCATOR 1121 default y 1122 ---help--- 1123 Machine Check support allows the processor to notify the 1124 kernel if it detects a problem (e.g. overheating, data corruption). 1125 The action the kernel takes depends on the severity of the problem, 1126 ranging from warning messages to halting the machine. 1127 1128config X86_MCELOG_LEGACY 1129 bool "Support for deprecated /dev/mcelog character device" 1130 depends on X86_MCE 1131 ---help--- 1132 Enable support for /dev/mcelog which is needed by the old mcelog 1133 userspace logging daemon. Consider switching to the new generation 1134 rasdaemon solution. 1135 1136config X86_MCE_INTEL 1137 def_bool y 1138 prompt "Intel MCE features" 1139 depends on X86_MCE && X86_LOCAL_APIC 1140 ---help--- 1141 Additional support for intel specific MCE features such as 1142 the thermal monitor. 1143 1144config X86_MCE_AMD 1145 def_bool y 1146 prompt "AMD MCE features" 1147 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1148 ---help--- 1149 Additional support for AMD specific MCE features such as 1150 the DRAM Error Threshold. 1151 1152config X86_ANCIENT_MCE 1153 bool "Support for old Pentium 5 / WinChip machine checks" 1154 depends on X86_32 && X86_MCE 1155 ---help--- 1156 Include support for machine check handling on old Pentium 5 or WinChip 1157 systems. These typically need to be enabled explicitly on the command 1158 line. 1159 1160config X86_MCE_THRESHOLD 1161 depends on X86_MCE_AMD || X86_MCE_INTEL 1162 def_bool y 1163 1164config X86_MCE_INJECT 1165 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1166 tristate "Machine check injector support" 1167 ---help--- 1168 Provide support for injecting machine checks for testing purposes. 1169 If you don't know what a machine check is and you don't do kernel 1170 QA it is safe to say n. 1171 1172config X86_THERMAL_VECTOR 1173 def_bool y 1174 depends on X86_MCE_INTEL 1175 1176source "arch/x86/events/Kconfig" 1177 1178config X86_LEGACY_VM86 1179 bool "Legacy VM86 support" 1180 default n 1181 depends on X86_32 1182 ---help--- 1183 This option allows user programs to put the CPU into V8086 1184 mode, which is an 80286-era approximation of 16-bit real mode. 1185 1186 Some very old versions of X and/or vbetool require this option 1187 for user mode setting. Similarly, DOSEMU will use it if 1188 available to accelerate real mode DOS programs. However, any 1189 recent version of DOSEMU, X, or vbetool should be fully 1190 functional even without kernel VM86 support, as they will all 1191 fall back to software emulation. Nevertheless, if you are using 1192 a 16-bit DOS program where 16-bit performance matters, vm86 1193 mode might be faster than emulation and you might want to 1194 enable this option. 1195 1196 Note that any app that works on a 64-bit kernel is unlikely to 1197 need this option, as 64-bit kernels don't, and can't, support 1198 V8086 mode. This option is also unrelated to 16-bit protected 1199 mode and is not needed to run most 16-bit programs under Wine. 1200 1201 Enabling this option increases the complexity of the kernel 1202 and slows down exception handling a tiny bit. 1203 1204 If unsure, say N here. 1205 1206config VM86 1207 bool 1208 default X86_LEGACY_VM86 1209 1210config X86_16BIT 1211 bool "Enable support for 16-bit segments" if EXPERT 1212 default y 1213 depends on MODIFY_LDT_SYSCALL 1214 ---help--- 1215 This option is required by programs like Wine to run 16-bit 1216 protected mode legacy code on x86 processors. Disabling 1217 this option saves about 300 bytes on i386, or around 6K text 1218 plus 16K runtime memory on x86-64, 1219 1220config X86_ESPFIX32 1221 def_bool y 1222 depends on X86_16BIT && X86_32 1223 1224config X86_ESPFIX64 1225 def_bool y 1226 depends on X86_16BIT && X86_64 1227 1228config X86_VSYSCALL_EMULATION 1229 bool "Enable vsyscall emulation" if EXPERT 1230 default y 1231 depends on X86_64 1232 ---help--- 1233 This enables emulation of the legacy vsyscall page. Disabling 1234 it is roughly equivalent to booting with vsyscall=none, except 1235 that it will also disable the helpful warning if a program 1236 tries to use a vsyscall. With this option set to N, offending 1237 programs will just segfault, citing addresses of the form 1238 0xffffffffff600?00. 1239 1240 This option is required by many programs built before 2013, and 1241 care should be used even with newer programs if set to N. 1242 1243 Disabling this option saves about 7K of kernel size and 1244 possibly 4K of additional runtime pagetable memory. 1245 1246config TOSHIBA 1247 tristate "Toshiba Laptop support" 1248 depends on X86_32 1249 ---help--- 1250 This adds a driver to safely access the System Management Mode of 1251 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1252 not work on models with a Phoenix BIOS. The System Management Mode 1253 is used to set the BIOS and power saving options on Toshiba portables. 1254 1255 For information on utilities to make use of this driver see the 1256 Toshiba Linux utilities web site at: 1257 <http://www.buzzard.org.uk/toshiba/>. 1258 1259 Say Y if you intend to run this kernel on a Toshiba portable. 1260 Say N otherwise. 1261 1262config I8K 1263 tristate "Dell i8k legacy laptop support" 1264 select HWMON 1265 select SENSORS_DELL_SMM 1266 ---help--- 1267 This option enables legacy /proc/i8k userspace interface in hwmon 1268 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1269 temperature and allows controlling fan speeds of Dell laptops via 1270 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1271 it reports also power and hotkey status. For fan speed control is 1272 needed userspace package i8kutils. 1273 1274 Say Y if you intend to run this kernel on old Dell laptops or want to 1275 use userspace package i8kutils. 1276 Say N otherwise. 1277 1278config X86_REBOOTFIXUPS 1279 bool "Enable X86 board specific fixups for reboot" 1280 depends on X86_32 1281 ---help--- 1282 This enables chipset and/or board specific fixups to be done 1283 in order to get reboot to work correctly. This is only needed on 1284 some combinations of hardware and BIOS. The symptom, for which 1285 this config is intended, is when reboot ends with a stalled/hung 1286 system. 1287 1288 Currently, the only fixup is for the Geode machines using 1289 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1290 1291 Say Y if you want to enable the fixup. Currently, it's safe to 1292 enable this option even if you don't need it. 1293 Say N otherwise. 1294 1295config MICROCODE 1296 bool "CPU microcode loading support" 1297 default y 1298 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1299 select FW_LOADER 1300 ---help--- 1301 If you say Y here, you will be able to update the microcode on 1302 Intel and AMD processors. The Intel support is for the IA32 family, 1303 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1304 AMD support is for families 0x10 and later. You will obviously need 1305 the actual microcode binary data itself which is not shipped with 1306 the Linux kernel. 1307 1308 The preferred method to load microcode from a detached initrd is described 1309 in Documentation/x86/early-microcode.txt. For that you need to enable 1310 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1311 initrd for microcode blobs. 1312 1313 In addition, you can build the microcode into the kernel. For that you 1314 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1315 config option. 1316 1317config MICROCODE_INTEL 1318 bool "Intel microcode loading support" 1319 depends on MICROCODE 1320 default MICROCODE 1321 select FW_LOADER 1322 ---help--- 1323 This options enables microcode patch loading support for Intel 1324 processors. 1325 1326 For the current Intel microcode data package go to 1327 <https://downloadcenter.intel.com> and search for 1328 'Linux Processor Microcode Data File'. 1329 1330config MICROCODE_AMD 1331 bool "AMD microcode loading support" 1332 depends on MICROCODE 1333 select FW_LOADER 1334 ---help--- 1335 If you select this option, microcode patch loading support for AMD 1336 processors will be enabled. 1337 1338config MICROCODE_OLD_INTERFACE 1339 def_bool y 1340 depends on MICROCODE 1341 1342config X86_MSR 1343 tristate "/dev/cpu/*/msr - Model-specific register support" 1344 ---help--- 1345 This device gives privileged processes access to the x86 1346 Model-Specific Registers (MSRs). It is a character device with 1347 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1348 MSR accesses are directed to a specific CPU on multi-processor 1349 systems. 1350 1351config X86_CPUID 1352 tristate "/dev/cpu/*/cpuid - CPU information support" 1353 ---help--- 1354 This device gives processes access to the x86 CPUID instruction to 1355 be executed on a specific processor. It is a character device 1356 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1357 /dev/cpu/31/cpuid. 1358 1359choice 1360 prompt "High Memory Support" 1361 default HIGHMEM4G 1362 depends on X86_32 1363 1364config NOHIGHMEM 1365 bool "off" 1366 ---help--- 1367 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1368 However, the address space of 32-bit x86 processors is only 4 1369 Gigabytes large. That means that, if you have a large amount of 1370 physical memory, not all of it can be "permanently mapped" by the 1371 kernel. The physical memory that's not permanently mapped is called 1372 "high memory". 1373 1374 If you are compiling a kernel which will never run on a machine with 1375 more than 1 Gigabyte total physical RAM, answer "off" here (default 1376 choice and suitable for most users). This will result in a "3GB/1GB" 1377 split: 3GB are mapped so that each process sees a 3GB virtual memory 1378 space and the remaining part of the 4GB virtual memory space is used 1379 by the kernel to permanently map as much physical memory as 1380 possible. 1381 1382 If the machine has between 1 and 4 Gigabytes physical RAM, then 1383 answer "4GB" here. 1384 1385 If more than 4 Gigabytes is used then answer "64GB" here. This 1386 selection turns Intel PAE (Physical Address Extension) mode on. 1387 PAE implements 3-level paging on IA32 processors. PAE is fully 1388 supported by Linux, PAE mode is implemented on all recent Intel 1389 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1390 then the kernel will not boot on CPUs that don't support PAE! 1391 1392 The actual amount of total physical memory will either be 1393 auto detected or can be forced by using a kernel command line option 1394 such as "mem=256M". (Try "man bootparam" or see the documentation of 1395 your boot loader (lilo or loadlin) about how to pass options to the 1396 kernel at boot time.) 1397 1398 If unsure, say "off". 1399 1400config HIGHMEM4G 1401 bool "4GB" 1402 ---help--- 1403 Select this if you have a 32-bit processor and between 1 and 4 1404 gigabytes of physical RAM. 1405 1406config HIGHMEM64G 1407 bool "64GB" 1408 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1409 select X86_PAE 1410 ---help--- 1411 Select this if you have a 32-bit processor and more than 4 1412 gigabytes of physical RAM. 1413 1414endchoice 1415 1416choice 1417 prompt "Memory split" if EXPERT 1418 default VMSPLIT_3G 1419 depends on X86_32 1420 ---help--- 1421 Select the desired split between kernel and user memory. 1422 1423 If the address range available to the kernel is less than the 1424 physical memory installed, the remaining memory will be available 1425 as "high memory". Accessing high memory is a little more costly 1426 than low memory, as it needs to be mapped into the kernel first. 1427 Note that increasing the kernel address space limits the range 1428 available to user programs, making the address space there 1429 tighter. Selecting anything other than the default 3G/1G split 1430 will also likely make your kernel incompatible with binary-only 1431 kernel modules. 1432 1433 If you are not absolutely sure what you are doing, leave this 1434 option alone! 1435 1436 config VMSPLIT_3G 1437 bool "3G/1G user/kernel split" 1438 config VMSPLIT_3G_OPT 1439 depends on !X86_PAE 1440 bool "3G/1G user/kernel split (for full 1G low memory)" 1441 config VMSPLIT_2G 1442 bool "2G/2G user/kernel split" 1443 config VMSPLIT_2G_OPT 1444 depends on !X86_PAE 1445 bool "2G/2G user/kernel split (for full 2G low memory)" 1446 config VMSPLIT_1G 1447 bool "1G/3G user/kernel split" 1448endchoice 1449 1450config PAGE_OFFSET 1451 hex 1452 default 0xB0000000 if VMSPLIT_3G_OPT 1453 default 0x80000000 if VMSPLIT_2G 1454 default 0x78000000 if VMSPLIT_2G_OPT 1455 default 0x40000000 if VMSPLIT_1G 1456 default 0xC0000000 1457 depends on X86_32 1458 1459config HIGHMEM 1460 def_bool y 1461 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1462 1463config X86_PAE 1464 bool "PAE (Physical Address Extension) Support" 1465 depends on X86_32 && !HIGHMEM4G 1466 select SWIOTLB 1467 ---help--- 1468 PAE is required for NX support, and furthermore enables 1469 larger swapspace support for non-overcommit purposes. It 1470 has the cost of more pagetable lookup overhead, and also 1471 consumes more pagetable space per process. 1472 1473config X86_5LEVEL 1474 bool "Enable 5-level page tables support" 1475 depends on X86_64 1476 ---help--- 1477 5-level paging enables access to larger address space: 1478 upto 128 PiB of virtual address space and 4 PiB of 1479 physical address space. 1480 1481 It will be supported by future Intel CPUs. 1482 1483 Note: a kernel with this option enabled can only be booted 1484 on machines that support the feature. 1485 1486 See Documentation/x86/x86_64/5level-paging.txt for more 1487 information. 1488 1489 Say N if unsure. 1490 1491config ARCH_PHYS_ADDR_T_64BIT 1492 def_bool y 1493 depends on X86_64 || X86_PAE 1494 1495config ARCH_DMA_ADDR_T_64BIT 1496 def_bool y 1497 depends on X86_64 || HIGHMEM64G 1498 1499config X86_DIRECT_GBPAGES 1500 def_bool y 1501 depends on X86_64 && !DEBUG_PAGEALLOC 1502 ---help--- 1503 Certain kernel features effectively disable kernel 1504 linear 1 GB mappings (even if the CPU otherwise 1505 supports them), so don't confuse the user by printing 1506 that we have them enabled. 1507 1508config ARCH_HAS_MEM_ENCRYPT 1509 def_bool y 1510 1511config AMD_MEM_ENCRYPT 1512 bool "AMD Secure Memory Encryption (SME) support" 1513 depends on X86_64 && CPU_SUP_AMD 1514 ---help--- 1515 Say yes to enable support for the encryption of system memory. 1516 This requires an AMD processor that supports Secure Memory 1517 Encryption (SME). 1518 1519config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1520 bool "Activate AMD Secure Memory Encryption (SME) by default" 1521 default y 1522 depends on AMD_MEM_ENCRYPT 1523 ---help--- 1524 Say yes to have system memory encrypted by default if running on 1525 an AMD processor that supports Secure Memory Encryption (SME). 1526 1527 If set to Y, then the encryption of system memory can be 1528 deactivated with the mem_encrypt=off command line option. 1529 1530 If set to N, then the encryption of system memory can be 1531 activated with the mem_encrypt=on command line option. 1532 1533config ARCH_USE_MEMREMAP_PROT 1534 def_bool y 1535 depends on AMD_MEM_ENCRYPT 1536 1537# Common NUMA Features 1538config NUMA 1539 bool "Numa Memory Allocation and Scheduler Support" 1540 depends on SMP 1541 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1542 default y if X86_BIGSMP 1543 ---help--- 1544 Enable NUMA (Non Uniform Memory Access) support. 1545 1546 The kernel will try to allocate memory used by a CPU on the 1547 local memory controller of the CPU and add some more 1548 NUMA awareness to the kernel. 1549 1550 For 64-bit this is recommended if the system is Intel Core i7 1551 (or later), AMD Opteron, or EM64T NUMA. 1552 1553 For 32-bit this is only needed if you boot a 32-bit 1554 kernel on a 64-bit NUMA platform. 1555 1556 Otherwise, you should say N. 1557 1558config AMD_NUMA 1559 def_bool y 1560 prompt "Old style AMD Opteron NUMA detection" 1561 depends on X86_64 && NUMA && PCI 1562 ---help--- 1563 Enable AMD NUMA node topology detection. You should say Y here if 1564 you have a multi processor AMD system. This uses an old method to 1565 read the NUMA configuration directly from the builtin Northbridge 1566 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1567 which also takes priority if both are compiled in. 1568 1569config X86_64_ACPI_NUMA 1570 def_bool y 1571 prompt "ACPI NUMA detection" 1572 depends on X86_64 && NUMA && ACPI && PCI 1573 select ACPI_NUMA 1574 ---help--- 1575 Enable ACPI SRAT based node topology detection. 1576 1577# Some NUMA nodes have memory ranges that span 1578# other nodes. Even though a pfn is valid and 1579# between a node's start and end pfns, it may not 1580# reside on that node. See memmap_init_zone() 1581# for details. 1582config NODES_SPAN_OTHER_NODES 1583 def_bool y 1584 depends on X86_64_ACPI_NUMA 1585 1586config NUMA_EMU 1587 bool "NUMA emulation" 1588 depends on NUMA 1589 ---help--- 1590 Enable NUMA emulation. A flat machine will be split 1591 into virtual nodes when booted with "numa=fake=N", where N is the 1592 number of nodes. This is only useful for debugging. 1593 1594config NODES_SHIFT 1595 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1596 range 1 10 1597 default "10" if MAXSMP 1598 default "6" if X86_64 1599 default "3" 1600 depends on NEED_MULTIPLE_NODES 1601 ---help--- 1602 Specify the maximum number of NUMA Nodes available on the target 1603 system. Increases memory reserved to accommodate various tables. 1604 1605config ARCH_HAVE_MEMORY_PRESENT 1606 def_bool y 1607 depends on X86_32 && DISCONTIGMEM 1608 1609config NEED_NODE_MEMMAP_SIZE 1610 def_bool y 1611 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1612 1613config ARCH_FLATMEM_ENABLE 1614 def_bool y 1615 depends on X86_32 && !NUMA 1616 1617config ARCH_DISCONTIGMEM_ENABLE 1618 def_bool y 1619 depends on NUMA && X86_32 1620 1621config ARCH_DISCONTIGMEM_DEFAULT 1622 def_bool y 1623 depends on NUMA && X86_32 1624 1625config ARCH_SPARSEMEM_ENABLE 1626 def_bool y 1627 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1628 select SPARSEMEM_STATIC if X86_32 1629 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1630 1631config ARCH_SPARSEMEM_DEFAULT 1632 def_bool y 1633 depends on X86_64 1634 1635config ARCH_SELECT_MEMORY_MODEL 1636 def_bool y 1637 depends on ARCH_SPARSEMEM_ENABLE 1638 1639config ARCH_MEMORY_PROBE 1640 bool "Enable sysfs memory/probe interface" 1641 depends on X86_64 && MEMORY_HOTPLUG 1642 help 1643 This option enables a sysfs memory/probe interface for testing. 1644 See Documentation/memory-hotplug.txt for more information. 1645 If you are unsure how to answer this question, answer N. 1646 1647config ARCH_PROC_KCORE_TEXT 1648 def_bool y 1649 depends on X86_64 && PROC_KCORE 1650 1651config ILLEGAL_POINTER_VALUE 1652 hex 1653 default 0 if X86_32 1654 default 0xdead000000000000 if X86_64 1655 1656source "mm/Kconfig" 1657 1658config X86_PMEM_LEGACY_DEVICE 1659 bool 1660 1661config X86_PMEM_LEGACY 1662 tristate "Support non-standard NVDIMMs and ADR protected memory" 1663 depends on PHYS_ADDR_T_64BIT 1664 depends on BLK_DEV 1665 select X86_PMEM_LEGACY_DEVICE 1666 select LIBNVDIMM 1667 help 1668 Treat memory marked using the non-standard e820 type of 12 as used 1669 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1670 The kernel will offer these regions to the 'pmem' driver so 1671 they can be used for persistent storage. 1672 1673 Say Y if unsure. 1674 1675config HIGHPTE 1676 bool "Allocate 3rd-level pagetables from highmem" 1677 depends on HIGHMEM 1678 ---help--- 1679 The VM uses one page table entry for each page of physical memory. 1680 For systems with a lot of RAM, this can be wasteful of precious 1681 low memory. Setting this option will put user-space page table 1682 entries in high memory. 1683 1684config X86_CHECK_BIOS_CORRUPTION 1685 bool "Check for low memory corruption" 1686 ---help--- 1687 Periodically check for memory corruption in low memory, which 1688 is suspected to be caused by BIOS. Even when enabled in the 1689 configuration, it is disabled at runtime. Enable it by 1690 setting "memory_corruption_check=1" on the kernel command 1691 line. By default it scans the low 64k of memory every 60 1692 seconds; see the memory_corruption_check_size and 1693 memory_corruption_check_period parameters in 1694 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1695 1696 When enabled with the default parameters, this option has 1697 almost no overhead, as it reserves a relatively small amount 1698 of memory and scans it infrequently. It both detects corruption 1699 and prevents it from affecting the running system. 1700 1701 It is, however, intended as a diagnostic tool; if repeatable 1702 BIOS-originated corruption always affects the same memory, 1703 you can use memmap= to prevent the kernel from using that 1704 memory. 1705 1706config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1707 bool "Set the default setting of memory_corruption_check" 1708 depends on X86_CHECK_BIOS_CORRUPTION 1709 default y 1710 ---help--- 1711 Set whether the default state of memory_corruption_check is 1712 on or off. 1713 1714config X86_RESERVE_LOW 1715 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1716 default 64 1717 range 4 640 1718 ---help--- 1719 Specify the amount of low memory to reserve for the BIOS. 1720 1721 The first page contains BIOS data structures that the kernel 1722 must not use, so that page must always be reserved. 1723 1724 By default we reserve the first 64K of physical RAM, as a 1725 number of BIOSes are known to corrupt that memory range 1726 during events such as suspend/resume or monitor cable 1727 insertion, so it must not be used by the kernel. 1728 1729 You can set this to 4 if you are absolutely sure that you 1730 trust the BIOS to get all its memory reservations and usages 1731 right. If you know your BIOS have problems beyond the 1732 default 64K area, you can set this to 640 to avoid using the 1733 entire low memory range. 1734 1735 If you have doubts about the BIOS (e.g. suspend/resume does 1736 not work or there's kernel crashes after certain hardware 1737 hotplug events) then you might want to enable 1738 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1739 typical corruption patterns. 1740 1741 Leave this to the default value of 64 if you are unsure. 1742 1743config MATH_EMULATION 1744 bool 1745 depends on MODIFY_LDT_SYSCALL 1746 prompt "Math emulation" if X86_32 1747 ---help--- 1748 Linux can emulate a math coprocessor (used for floating point 1749 operations) if you don't have one. 486DX and Pentium processors have 1750 a math coprocessor built in, 486SX and 386 do not, unless you added 1751 a 487DX or 387, respectively. (The messages during boot time can 1752 give you some hints here ["man dmesg"].) Everyone needs either a 1753 coprocessor or this emulation. 1754 1755 If you don't have a math coprocessor, you need to say Y here; if you 1756 say Y here even though you have a coprocessor, the coprocessor will 1757 be used nevertheless. (This behavior can be changed with the kernel 1758 command line option "no387", which comes handy if your coprocessor 1759 is broken. Try "man bootparam" or see the documentation of your boot 1760 loader (lilo or loadlin) about how to pass options to the kernel at 1761 boot time.) This means that it is a good idea to say Y here if you 1762 intend to use this kernel on different machines. 1763 1764 More information about the internals of the Linux math coprocessor 1765 emulation can be found in <file:arch/x86/math-emu/README>. 1766 1767 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1768 kernel, it won't hurt. 1769 1770config MTRR 1771 def_bool y 1772 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1773 ---help--- 1774 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1775 the Memory Type Range Registers (MTRRs) may be used to control 1776 processor access to memory ranges. This is most useful if you have 1777 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1778 allows bus write transfers to be combined into a larger transfer 1779 before bursting over the PCI/AGP bus. This can increase performance 1780 of image write operations 2.5 times or more. Saying Y here creates a 1781 /proc/mtrr file which may be used to manipulate your processor's 1782 MTRRs. Typically the X server should use this. 1783 1784 This code has a reasonably generic interface so that similar 1785 control registers on other processors can be easily supported 1786 as well: 1787 1788 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1789 Registers (ARRs) which provide a similar functionality to MTRRs. For 1790 these, the ARRs are used to emulate the MTRRs. 1791 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1792 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1793 write-combining. All of these processors are supported by this code 1794 and it makes sense to say Y here if you have one of them. 1795 1796 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1797 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1798 can lead to all sorts of problems, so it's good to say Y here. 1799 1800 You can safely say Y even if your machine doesn't have MTRRs, you'll 1801 just add about 9 KB to your kernel. 1802 1803 See <file:Documentation/x86/mtrr.txt> for more information. 1804 1805config MTRR_SANITIZER 1806 def_bool y 1807 prompt "MTRR cleanup support" 1808 depends on MTRR 1809 ---help--- 1810 Convert MTRR layout from continuous to discrete, so X drivers can 1811 add writeback entries. 1812 1813 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1814 The largest mtrr entry size for a continuous block can be set with 1815 mtrr_chunk_size. 1816 1817 If unsure, say Y. 1818 1819config MTRR_SANITIZER_ENABLE_DEFAULT 1820 int "MTRR cleanup enable value (0-1)" 1821 range 0 1 1822 default "0" 1823 depends on MTRR_SANITIZER 1824 ---help--- 1825 Enable mtrr cleanup default value 1826 1827config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1828 int "MTRR cleanup spare reg num (0-7)" 1829 range 0 7 1830 default "1" 1831 depends on MTRR_SANITIZER 1832 ---help--- 1833 mtrr cleanup spare entries default, it can be changed via 1834 mtrr_spare_reg_nr=N on the kernel command line. 1835 1836config X86_PAT 1837 def_bool y 1838 prompt "x86 PAT support" if EXPERT 1839 depends on MTRR 1840 ---help--- 1841 Use PAT attributes to setup page level cache control. 1842 1843 PATs are the modern equivalents of MTRRs and are much more 1844 flexible than MTRRs. 1845 1846 Say N here if you see bootup problems (boot crash, boot hang, 1847 spontaneous reboots) or a non-working video driver. 1848 1849 If unsure, say Y. 1850 1851config ARCH_USES_PG_UNCACHED 1852 def_bool y 1853 depends on X86_PAT 1854 1855config ARCH_RANDOM 1856 def_bool y 1857 prompt "x86 architectural random number generator" if EXPERT 1858 ---help--- 1859 Enable the x86 architectural RDRAND instruction 1860 (Intel Bull Mountain technology) to generate random numbers. 1861 If supported, this is a high bandwidth, cryptographically 1862 secure hardware random number generator. 1863 1864config X86_SMAP 1865 def_bool y 1866 prompt "Supervisor Mode Access Prevention" if EXPERT 1867 ---help--- 1868 Supervisor Mode Access Prevention (SMAP) is a security 1869 feature in newer Intel processors. There is a small 1870 performance cost if this enabled and turned on; there is 1871 also a small increase in the kernel size if this is enabled. 1872 1873 If unsure, say Y. 1874 1875config X86_INTEL_UMIP 1876 def_bool y 1877 depends on CPU_SUP_INTEL 1878 prompt "Intel User Mode Instruction Prevention" if EXPERT 1879 ---help--- 1880 The User Mode Instruction Prevention (UMIP) is a security 1881 feature in newer Intel processors. If enabled, a general 1882 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1883 or STR instructions are executed in user mode. These instructions 1884 unnecessarily expose information about the hardware state. 1885 1886 The vast majority of applications do not use these instructions. 1887 For the very few that do, software emulation is provided in 1888 specific cases in protected and virtual-8086 modes. Emulated 1889 results are dummy. 1890 1891config X86_INTEL_MPX 1892 prompt "Intel MPX (Memory Protection Extensions)" 1893 def_bool n 1894 # Note: only available in 64-bit mode due to VMA flags shortage 1895 depends on CPU_SUP_INTEL && X86_64 1896 select ARCH_USES_HIGH_VMA_FLAGS 1897 ---help--- 1898 MPX provides hardware features that can be used in 1899 conjunction with compiler-instrumented code to check 1900 memory references. It is designed to detect buffer 1901 overflow or underflow bugs. 1902 1903 This option enables running applications which are 1904 instrumented or otherwise use MPX. It does not use MPX 1905 itself inside the kernel or to protect the kernel 1906 against bad memory references. 1907 1908 Enabling this option will make the kernel larger: 1909 ~8k of kernel text and 36 bytes of data on a 64-bit 1910 defconfig. It adds a long to the 'mm_struct' which 1911 will increase the kernel memory overhead of each 1912 process and adds some branches to paths used during 1913 exec() and munmap(). 1914 1915 For details, see Documentation/x86/intel_mpx.txt 1916 1917 If unsure, say N. 1918 1919config X86_INTEL_MEMORY_PROTECTION_KEYS 1920 prompt "Intel Memory Protection Keys" 1921 def_bool y 1922 # Note: only available in 64-bit mode 1923 depends on CPU_SUP_INTEL && X86_64 1924 select ARCH_USES_HIGH_VMA_FLAGS 1925 select ARCH_HAS_PKEYS 1926 ---help--- 1927 Memory Protection Keys provides a mechanism for enforcing 1928 page-based protections, but without requiring modification of the 1929 page tables when an application changes protection domains. 1930 1931 For details, see Documentation/x86/protection-keys.txt 1932 1933 If unsure, say y. 1934 1935config EFI 1936 bool "EFI runtime service support" 1937 depends on ACPI 1938 select UCS2_STRING 1939 select EFI_RUNTIME_WRAPPERS 1940 ---help--- 1941 This enables the kernel to use EFI runtime services that are 1942 available (such as the EFI variable services). 1943 1944 This option is only useful on systems that have EFI firmware. 1945 In addition, you should use the latest ELILO loader available 1946 at <http://elilo.sourceforge.net> in order to take advantage 1947 of EFI runtime services. However, even with this option, the 1948 resultant kernel should continue to boot on existing non-EFI 1949 platforms. 1950 1951config EFI_STUB 1952 bool "EFI stub support" 1953 depends on EFI && !X86_USE_3DNOW 1954 select RELOCATABLE 1955 ---help--- 1956 This kernel feature allows a bzImage to be loaded directly 1957 by EFI firmware without the use of a bootloader. 1958 1959 See Documentation/efi-stub.txt for more information. 1960 1961config EFI_MIXED 1962 bool "EFI mixed-mode support" 1963 depends on EFI_STUB && X86_64 1964 ---help--- 1965 Enabling this feature allows a 64-bit kernel to be booted 1966 on a 32-bit firmware, provided that your CPU supports 64-bit 1967 mode. 1968 1969 Note that it is not possible to boot a mixed-mode enabled 1970 kernel via the EFI boot stub - a bootloader that supports 1971 the EFI handover protocol must be used. 1972 1973 If unsure, say N. 1974 1975config SECCOMP 1976 def_bool y 1977 prompt "Enable seccomp to safely compute untrusted bytecode" 1978 ---help--- 1979 This kernel feature is useful for number crunching applications 1980 that may need to compute untrusted bytecode during their 1981 execution. By using pipes or other transports made available to 1982 the process as file descriptors supporting the read/write 1983 syscalls, it's possible to isolate those applications in 1984 their own address space using seccomp. Once seccomp is 1985 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1986 and the task is only allowed to execute a few safe syscalls 1987 defined by each seccomp mode. 1988 1989 If unsure, say Y. Only embedded should say N here. 1990 1991source kernel/Kconfig.hz 1992 1993config KEXEC 1994 bool "kexec system call" 1995 select KEXEC_CORE 1996 ---help--- 1997 kexec is a system call that implements the ability to shutdown your 1998 current kernel, and to start another kernel. It is like a reboot 1999 but it is independent of the system firmware. And like a reboot 2000 you can start any kernel with it, not just Linux. 2001 2002 The name comes from the similarity to the exec system call. 2003 2004 It is an ongoing process to be certain the hardware in a machine 2005 is properly shutdown, so do not be surprised if this code does not 2006 initially work for you. As of this writing the exact hardware 2007 interface is strongly in flux, so no good recommendation can be 2008 made. 2009 2010config KEXEC_FILE 2011 bool "kexec file based system call" 2012 select KEXEC_CORE 2013 select BUILD_BIN2C 2014 depends on X86_64 2015 depends on CRYPTO=y 2016 depends on CRYPTO_SHA256=y 2017 ---help--- 2018 This is new version of kexec system call. This system call is 2019 file based and takes file descriptors as system call argument 2020 for kernel and initramfs as opposed to list of segments as 2021 accepted by previous system call. 2022 2023config KEXEC_VERIFY_SIG 2024 bool "Verify kernel signature during kexec_file_load() syscall" 2025 depends on KEXEC_FILE 2026 ---help--- 2027 This option makes kernel signature verification mandatory for 2028 the kexec_file_load() syscall. 2029 2030 In addition to that option, you need to enable signature 2031 verification for the corresponding kernel image type being 2032 loaded in order for this to work. 2033 2034config KEXEC_BZIMAGE_VERIFY_SIG 2035 bool "Enable bzImage signature verification support" 2036 depends on KEXEC_VERIFY_SIG 2037 depends on SIGNED_PE_FILE_VERIFICATION 2038 select SYSTEM_TRUSTED_KEYRING 2039 ---help--- 2040 Enable bzImage signature verification support. 2041 2042config CRASH_DUMP 2043 bool "kernel crash dumps" 2044 depends on X86_64 || (X86_32 && HIGHMEM) 2045 ---help--- 2046 Generate crash dump after being started by kexec. 2047 This should be normally only set in special crash dump kernels 2048 which are loaded in the main kernel with kexec-tools into 2049 a specially reserved region and then later executed after 2050 a crash by kdump/kexec. The crash dump kernel must be compiled 2051 to a memory address not used by the main kernel or BIOS using 2052 PHYSICAL_START, or it must be built as a relocatable image 2053 (CONFIG_RELOCATABLE=y). 2054 For more details see Documentation/kdump/kdump.txt 2055 2056config KEXEC_JUMP 2057 bool "kexec jump" 2058 depends on KEXEC && HIBERNATION 2059 ---help--- 2060 Jump between original kernel and kexeced kernel and invoke 2061 code in physical address mode via KEXEC 2062 2063config PHYSICAL_START 2064 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2065 default "0x1000000" 2066 ---help--- 2067 This gives the physical address where the kernel is loaded. 2068 2069 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2070 bzImage will decompress itself to above physical address and 2071 run from there. Otherwise, bzImage will run from the address where 2072 it has been loaded by the boot loader and will ignore above physical 2073 address. 2074 2075 In normal kdump cases one does not have to set/change this option 2076 as now bzImage can be compiled as a completely relocatable image 2077 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2078 address. This option is mainly useful for the folks who don't want 2079 to use a bzImage for capturing the crash dump and want to use a 2080 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2081 to be specifically compiled to run from a specific memory area 2082 (normally a reserved region) and this option comes handy. 2083 2084 So if you are using bzImage for capturing the crash dump, 2085 leave the value here unchanged to 0x1000000 and set 2086 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2087 for capturing the crash dump change this value to start of 2088 the reserved region. In other words, it can be set based on 2089 the "X" value as specified in the "crashkernel=YM@XM" 2090 command line boot parameter passed to the panic-ed 2091 kernel. Please take a look at Documentation/kdump/kdump.txt 2092 for more details about crash dumps. 2093 2094 Usage of bzImage for capturing the crash dump is recommended as 2095 one does not have to build two kernels. Same kernel can be used 2096 as production kernel and capture kernel. Above option should have 2097 gone away after relocatable bzImage support is introduced. But it 2098 is present because there are users out there who continue to use 2099 vmlinux for dump capture. This option should go away down the 2100 line. 2101 2102 Don't change this unless you know what you are doing. 2103 2104config RELOCATABLE 2105 bool "Build a relocatable kernel" 2106 default y 2107 ---help--- 2108 This builds a kernel image that retains relocation information 2109 so it can be loaded someplace besides the default 1MB. 2110 The relocations tend to make the kernel binary about 10% larger, 2111 but are discarded at runtime. 2112 2113 One use is for the kexec on panic case where the recovery kernel 2114 must live at a different physical address than the primary 2115 kernel. 2116 2117 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2118 it has been loaded at and the compile time physical address 2119 (CONFIG_PHYSICAL_START) is used as the minimum location. 2120 2121config RANDOMIZE_BASE 2122 bool "Randomize the address of the kernel image (KASLR)" 2123 depends on RELOCATABLE 2124 default y 2125 ---help--- 2126 In support of Kernel Address Space Layout Randomization (KASLR), 2127 this randomizes the physical address at which the kernel image 2128 is decompressed and the virtual address where the kernel 2129 image is mapped, as a security feature that deters exploit 2130 attempts relying on knowledge of the location of kernel 2131 code internals. 2132 2133 On 64-bit, the kernel physical and virtual addresses are 2134 randomized separately. The physical address will be anywhere 2135 between 16MB and the top of physical memory (up to 64TB). The 2136 virtual address will be randomized from 16MB up to 1GB (9 bits 2137 of entropy). Note that this also reduces the memory space 2138 available to kernel modules from 1.5GB to 1GB. 2139 2140 On 32-bit, the kernel physical and virtual addresses are 2141 randomized together. They will be randomized from 16MB up to 2142 512MB (8 bits of entropy). 2143 2144 Entropy is generated using the RDRAND instruction if it is 2145 supported. If RDTSC is supported, its value is mixed into 2146 the entropy pool as well. If neither RDRAND nor RDTSC are 2147 supported, then entropy is read from the i8254 timer. The 2148 usable entropy is limited by the kernel being built using 2149 2GB addressing, and that PHYSICAL_ALIGN must be at a 2150 minimum of 2MB. As a result, only 10 bits of entropy are 2151 theoretically possible, but the implementations are further 2152 limited due to memory layouts. 2153 2154 If unsure, say Y. 2155 2156# Relocation on x86 needs some additional build support 2157config X86_NEED_RELOCS 2158 def_bool y 2159 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2160 2161config PHYSICAL_ALIGN 2162 hex "Alignment value to which kernel should be aligned" 2163 default "0x200000" 2164 range 0x2000 0x1000000 if X86_32 2165 range 0x200000 0x1000000 if X86_64 2166 ---help--- 2167 This value puts the alignment restrictions on physical address 2168 where kernel is loaded and run from. Kernel is compiled for an 2169 address which meets above alignment restriction. 2170 2171 If bootloader loads the kernel at a non-aligned address and 2172 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2173 address aligned to above value and run from there. 2174 2175 If bootloader loads the kernel at a non-aligned address and 2176 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2177 load address and decompress itself to the address it has been 2178 compiled for and run from there. The address for which kernel is 2179 compiled already meets above alignment restrictions. Hence the 2180 end result is that kernel runs from a physical address meeting 2181 above alignment restrictions. 2182 2183 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2184 this value must be a multiple of 0x200000. 2185 2186 Don't change this unless you know what you are doing. 2187 2188config RANDOMIZE_MEMORY 2189 bool "Randomize the kernel memory sections" 2190 depends on X86_64 2191 depends on RANDOMIZE_BASE 2192 default RANDOMIZE_BASE 2193 ---help--- 2194 Randomizes the base virtual address of kernel memory sections 2195 (physical memory mapping, vmalloc & vmemmap). This security feature 2196 makes exploits relying on predictable memory locations less reliable. 2197 2198 The order of allocations remains unchanged. Entropy is generated in 2199 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2200 configuration have in average 30,000 different possible virtual 2201 addresses for each memory section. 2202 2203 If unsure, say Y. 2204 2205config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2206 hex "Physical memory mapping padding" if EXPERT 2207 depends on RANDOMIZE_MEMORY 2208 default "0xa" if MEMORY_HOTPLUG 2209 default "0x0" 2210 range 0x1 0x40 if MEMORY_HOTPLUG 2211 range 0x0 0x40 2212 ---help--- 2213 Define the padding in terabytes added to the existing physical 2214 memory size during kernel memory randomization. It is useful 2215 for memory hotplug support but reduces the entropy available for 2216 address randomization. 2217 2218 If unsure, leave at the default value. 2219 2220config HOTPLUG_CPU 2221 bool "Support for hot-pluggable CPUs" 2222 depends on SMP 2223 ---help--- 2224 Say Y here to allow turning CPUs off and on. CPUs can be 2225 controlled through /sys/devices/system/cpu. 2226 ( Note: power management support will enable this option 2227 automatically on SMP systems. ) 2228 Say N if you want to disable CPU hotplug. 2229 2230config BOOTPARAM_HOTPLUG_CPU0 2231 bool "Set default setting of cpu0_hotpluggable" 2232 default n 2233 depends on HOTPLUG_CPU 2234 ---help--- 2235 Set whether default state of cpu0_hotpluggable is on or off. 2236 2237 Say Y here to enable CPU0 hotplug by default. If this switch 2238 is turned on, there is no need to give cpu0_hotplug kernel 2239 parameter and the CPU0 hotplug feature is enabled by default. 2240 2241 Please note: there are two known CPU0 dependencies if you want 2242 to enable the CPU0 hotplug feature either by this switch or by 2243 cpu0_hotplug kernel parameter. 2244 2245 First, resume from hibernate or suspend always starts from CPU0. 2246 So hibernate and suspend are prevented if CPU0 is offline. 2247 2248 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2249 offline if any interrupt can not migrate out of CPU0. There may 2250 be other CPU0 dependencies. 2251 2252 Please make sure the dependencies are under your control before 2253 you enable this feature. 2254 2255 Say N if you don't want to enable CPU0 hotplug feature by default. 2256 You still can enable the CPU0 hotplug feature at boot by kernel 2257 parameter cpu0_hotplug. 2258 2259config DEBUG_HOTPLUG_CPU0 2260 def_bool n 2261 prompt "Debug CPU0 hotplug" 2262 depends on HOTPLUG_CPU 2263 ---help--- 2264 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2265 soon as possible and boots up userspace with CPU0 offlined. User 2266 can online CPU0 back after boot time. 2267 2268 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2269 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2270 compilation or giving cpu0_hotplug kernel parameter at boot. 2271 2272 If unsure, say N. 2273 2274config COMPAT_VDSO 2275 def_bool n 2276 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2277 depends on COMPAT_32 2278 ---help--- 2279 Certain buggy versions of glibc will crash if they are 2280 presented with a 32-bit vDSO that is not mapped at the address 2281 indicated in its segment table. 2282 2283 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2284 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2285 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2286 the only released version with the bug, but OpenSUSE 9 2287 contains a buggy "glibc 2.3.2". 2288 2289 The symptom of the bug is that everything crashes on startup, saying: 2290 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2291 2292 Saying Y here changes the default value of the vdso32 boot 2293 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2294 This works around the glibc bug but hurts performance. 2295 2296 If unsure, say N: if you are compiling your own kernel, you 2297 are unlikely to be using a buggy version of glibc. 2298 2299choice 2300 prompt "vsyscall table for legacy applications" 2301 depends on X86_64 2302 default LEGACY_VSYSCALL_EMULATE 2303 help 2304 Legacy user code that does not know how to find the vDSO expects 2305 to be able to issue three syscalls by calling fixed addresses in 2306 kernel space. Since this location is not randomized with ASLR, 2307 it can be used to assist security vulnerability exploitation. 2308 2309 This setting can be changed at boot time via the kernel command 2310 line parameter vsyscall=[native|emulate|none]. 2311 2312 On a system with recent enough glibc (2.14 or newer) and no 2313 static binaries, you can say None without a performance penalty 2314 to improve security. 2315 2316 If unsure, select "Emulate". 2317 2318 config LEGACY_VSYSCALL_NATIVE 2319 bool "Native" 2320 help 2321 Actual executable code is located in the fixed vsyscall 2322 address mapping, implementing time() efficiently. Since 2323 this makes the mapping executable, it can be used during 2324 security vulnerability exploitation (traditionally as 2325 ROP gadgets). This configuration is not recommended. 2326 2327 config LEGACY_VSYSCALL_EMULATE 2328 bool "Emulate" 2329 help 2330 The kernel traps and emulates calls into the fixed 2331 vsyscall address mapping. This makes the mapping 2332 non-executable, but it still contains known contents, 2333 which could be used in certain rare security vulnerability 2334 exploits. This configuration is recommended when userspace 2335 still uses the vsyscall area. 2336 2337 config LEGACY_VSYSCALL_NONE 2338 bool "None" 2339 help 2340 There will be no vsyscall mapping at all. This will 2341 eliminate any risk of ASLR bypass due to the vsyscall 2342 fixed address mapping. Attempts to use the vsyscalls 2343 will be reported to dmesg, so that either old or 2344 malicious userspace programs can be identified. 2345 2346endchoice 2347 2348config CMDLINE_BOOL 2349 bool "Built-in kernel command line" 2350 ---help--- 2351 Allow for specifying boot arguments to the kernel at 2352 build time. On some systems (e.g. embedded ones), it is 2353 necessary or convenient to provide some or all of the 2354 kernel boot arguments with the kernel itself (that is, 2355 to not rely on the boot loader to provide them.) 2356 2357 To compile command line arguments into the kernel, 2358 set this option to 'Y', then fill in the 2359 boot arguments in CONFIG_CMDLINE. 2360 2361 Systems with fully functional boot loaders (i.e. non-embedded) 2362 should leave this option set to 'N'. 2363 2364config CMDLINE 2365 string "Built-in kernel command string" 2366 depends on CMDLINE_BOOL 2367 default "" 2368 ---help--- 2369 Enter arguments here that should be compiled into the kernel 2370 image and used at boot time. If the boot loader provides a 2371 command line at boot time, it is appended to this string to 2372 form the full kernel command line, when the system boots. 2373 2374 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2375 change this behavior. 2376 2377 In most cases, the command line (whether built-in or provided 2378 by the boot loader) should specify the device for the root 2379 file system. 2380 2381config CMDLINE_OVERRIDE 2382 bool "Built-in command line overrides boot loader arguments" 2383 depends on CMDLINE_BOOL 2384 ---help--- 2385 Set this option to 'Y' to have the kernel ignore the boot loader 2386 command line, and use ONLY the built-in command line. 2387 2388 This is used to work around broken boot loaders. This should 2389 be set to 'N' under normal conditions. 2390 2391config MODIFY_LDT_SYSCALL 2392 bool "Enable the LDT (local descriptor table)" if EXPERT 2393 default y 2394 ---help--- 2395 Linux can allow user programs to install a per-process x86 2396 Local Descriptor Table (LDT) using the modify_ldt(2) system 2397 call. This is required to run 16-bit or segmented code such as 2398 DOSEMU or some Wine programs. It is also used by some very old 2399 threading libraries. 2400 2401 Enabling this feature adds a small amount of overhead to 2402 context switches and increases the low-level kernel attack 2403 surface. Disabling it removes the modify_ldt(2) system call. 2404 2405 Saying 'N' here may make sense for embedded or server kernels. 2406 2407source "kernel/livepatch/Kconfig" 2408 2409endmenu 2410 2411config ARCH_HAS_ADD_PAGES 2412 def_bool y 2413 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2414 2415config ARCH_ENABLE_MEMORY_HOTPLUG 2416 def_bool y 2417 depends on X86_64 || (X86_32 && HIGHMEM) 2418 2419config ARCH_ENABLE_MEMORY_HOTREMOVE 2420 def_bool y 2421 depends on MEMORY_HOTPLUG 2422 2423config USE_PERCPU_NUMA_NODE_ID 2424 def_bool y 2425 depends on NUMA 2426 2427config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2428 def_bool y 2429 depends on X86_64 || X86_PAE 2430 2431config ARCH_ENABLE_HUGEPAGE_MIGRATION 2432 def_bool y 2433 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2434 2435config ARCH_ENABLE_THP_MIGRATION 2436 def_bool y 2437 depends on X86_64 && TRANSPARENT_HUGEPAGE 2438 2439menu "Power management and ACPI options" 2440 2441config ARCH_HIBERNATION_HEADER 2442 def_bool y 2443 depends on X86_64 && HIBERNATION 2444 2445source "kernel/power/Kconfig" 2446 2447source "drivers/acpi/Kconfig" 2448 2449source "drivers/sfi/Kconfig" 2450 2451config X86_APM_BOOT 2452 def_bool y 2453 depends on APM 2454 2455menuconfig APM 2456 tristate "APM (Advanced Power Management) BIOS support" 2457 depends on X86_32 && PM_SLEEP 2458 ---help--- 2459 APM is a BIOS specification for saving power using several different 2460 techniques. This is mostly useful for battery powered laptops with 2461 APM compliant BIOSes. If you say Y here, the system time will be 2462 reset after a RESUME operation, the /proc/apm device will provide 2463 battery status information, and user-space programs will receive 2464 notification of APM "events" (e.g. battery status change). 2465 2466 If you select "Y" here, you can disable actual use of the APM 2467 BIOS by passing the "apm=off" option to the kernel at boot time. 2468 2469 Note that the APM support is almost completely disabled for 2470 machines with more than one CPU. 2471 2472 In order to use APM, you will need supporting software. For location 2473 and more information, read <file:Documentation/power/apm-acpi.txt> 2474 and the Battery Powered Linux mini-HOWTO, available from 2475 <http://www.tldp.org/docs.html#howto>. 2476 2477 This driver does not spin down disk drives (see the hdparm(8) 2478 manpage ("man 8 hdparm") for that), and it doesn't turn off 2479 VESA-compliant "green" monitors. 2480 2481 This driver does not support the TI 4000M TravelMate and the ACER 2482 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2483 desktop machines also don't have compliant BIOSes, and this driver 2484 may cause those machines to panic during the boot phase. 2485 2486 Generally, if you don't have a battery in your machine, there isn't 2487 much point in using this driver and you should say N. If you get 2488 random kernel OOPSes or reboots that don't seem to be related to 2489 anything, try disabling/enabling this option (or disabling/enabling 2490 APM in your BIOS). 2491 2492 Some other things you should try when experiencing seemingly random, 2493 "weird" problems: 2494 2495 1) make sure that you have enough swap space and that it is 2496 enabled. 2497 2) pass the "no-hlt" option to the kernel 2498 3) switch on floating point emulation in the kernel and pass 2499 the "no387" option to the kernel 2500 4) pass the "floppy=nodma" option to the kernel 2501 5) pass the "mem=4M" option to the kernel (thereby disabling 2502 all but the first 4 MB of RAM) 2503 6) make sure that the CPU is not over clocked. 2504 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2505 8) disable the cache from your BIOS settings 2506 9) install a fan for the video card or exchange video RAM 2507 10) install a better fan for the CPU 2508 11) exchange RAM chips 2509 12) exchange the motherboard. 2510 2511 To compile this driver as a module, choose M here: the 2512 module will be called apm. 2513 2514if APM 2515 2516config APM_IGNORE_USER_SUSPEND 2517 bool "Ignore USER SUSPEND" 2518 ---help--- 2519 This option will ignore USER SUSPEND requests. On machines with a 2520 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2521 series notebooks, it is necessary to say Y because of a BIOS bug. 2522 2523config APM_DO_ENABLE 2524 bool "Enable PM at boot time" 2525 ---help--- 2526 Enable APM features at boot time. From page 36 of the APM BIOS 2527 specification: "When disabled, the APM BIOS does not automatically 2528 power manage devices, enter the Standby State, enter the Suspend 2529 State, or take power saving steps in response to CPU Idle calls." 2530 This driver will make CPU Idle calls when Linux is idle (unless this 2531 feature is turned off -- see "Do CPU IDLE calls", below). This 2532 should always save battery power, but more complicated APM features 2533 will be dependent on your BIOS implementation. You may need to turn 2534 this option off if your computer hangs at boot time when using APM 2535 support, or if it beeps continuously instead of suspending. Turn 2536 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2537 T400CDT. This is off by default since most machines do fine without 2538 this feature. 2539 2540config APM_CPU_IDLE 2541 depends on CPU_IDLE 2542 bool "Make CPU Idle calls when idle" 2543 ---help--- 2544 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2545 On some machines, this can activate improved power savings, such as 2546 a slowed CPU clock rate, when the machine is idle. These idle calls 2547 are made after the idle loop has run for some length of time (e.g., 2548 333 mS). On some machines, this will cause a hang at boot time or 2549 whenever the CPU becomes idle. (On machines with more than one CPU, 2550 this option does nothing.) 2551 2552config APM_DISPLAY_BLANK 2553 bool "Enable console blanking using APM" 2554 ---help--- 2555 Enable console blanking using the APM. Some laptops can use this to 2556 turn off the LCD backlight when the screen blanker of the Linux 2557 virtual console blanks the screen. Note that this is only used by 2558 the virtual console screen blanker, and won't turn off the backlight 2559 when using the X Window system. This also doesn't have anything to 2560 do with your VESA-compliant power-saving monitor. Further, this 2561 option doesn't work for all laptops -- it might not turn off your 2562 backlight at all, or it might print a lot of errors to the console, 2563 especially if you are using gpm. 2564 2565config APM_ALLOW_INTS 2566 bool "Allow interrupts during APM BIOS calls" 2567 ---help--- 2568 Normally we disable external interrupts while we are making calls to 2569 the APM BIOS as a measure to lessen the effects of a badly behaving 2570 BIOS implementation. The BIOS should reenable interrupts if it 2571 needs to. Unfortunately, some BIOSes do not -- especially those in 2572 many of the newer IBM Thinkpads. If you experience hangs when you 2573 suspend, try setting this to Y. Otherwise, say N. 2574 2575endif # APM 2576 2577source "drivers/cpufreq/Kconfig" 2578 2579source "drivers/cpuidle/Kconfig" 2580 2581source "drivers/idle/Kconfig" 2582 2583endmenu 2584 2585 2586menu "Bus options (PCI etc.)" 2587 2588config PCI 2589 bool "PCI support" 2590 default y 2591 ---help--- 2592 Find out whether you have a PCI motherboard. PCI is the name of a 2593 bus system, i.e. the way the CPU talks to the other stuff inside 2594 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2595 VESA. If you have PCI, say Y, otherwise N. 2596 2597choice 2598 prompt "PCI access mode" 2599 depends on X86_32 && PCI 2600 default PCI_GOANY 2601 ---help--- 2602 On PCI systems, the BIOS can be used to detect the PCI devices and 2603 determine their configuration. However, some old PCI motherboards 2604 have BIOS bugs and may crash if this is done. Also, some embedded 2605 PCI-based systems don't have any BIOS at all. Linux can also try to 2606 detect the PCI hardware directly without using the BIOS. 2607 2608 With this option, you can specify how Linux should detect the 2609 PCI devices. If you choose "BIOS", the BIOS will be used, 2610 if you choose "Direct", the BIOS won't be used, and if you 2611 choose "MMConfig", then PCI Express MMCONFIG will be used. 2612 If you choose "Any", the kernel will try MMCONFIG, then the 2613 direct access method and falls back to the BIOS if that doesn't 2614 work. If unsure, go with the default, which is "Any". 2615 2616config PCI_GOBIOS 2617 bool "BIOS" 2618 2619config PCI_GOMMCONFIG 2620 bool "MMConfig" 2621 2622config PCI_GODIRECT 2623 bool "Direct" 2624 2625config PCI_GOOLPC 2626 bool "OLPC XO-1" 2627 depends on OLPC 2628 2629config PCI_GOANY 2630 bool "Any" 2631 2632endchoice 2633 2634config PCI_BIOS 2635 def_bool y 2636 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2637 2638# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2639config PCI_DIRECT 2640 def_bool y 2641 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2642 2643config PCI_MMCONFIG 2644 def_bool y 2645 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2646 2647config PCI_OLPC 2648 def_bool y 2649 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2650 2651config PCI_XEN 2652 def_bool y 2653 depends on PCI && XEN 2654 select SWIOTLB_XEN 2655 2656config PCI_DOMAINS 2657 def_bool y 2658 depends on PCI 2659 2660config PCI_MMCONFIG 2661 bool "Support mmconfig PCI config space access" 2662 depends on X86_64 && PCI && ACPI 2663 2664config PCI_CNB20LE_QUIRK 2665 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2666 depends on PCI 2667 help 2668 Read the PCI windows out of the CNB20LE host bridge. This allows 2669 PCI hotplug to work on systems with the CNB20LE chipset which do 2670 not have ACPI. 2671 2672 There's no public spec for this chipset, and this functionality 2673 is known to be incomplete. 2674 2675 You should say N unless you know you need this. 2676 2677source "drivers/pci/Kconfig" 2678 2679config ISA_BUS 2680 bool "ISA-style bus support on modern systems" if EXPERT 2681 select ISA_BUS_API 2682 help 2683 Enables ISA-style drivers on modern systems. This is necessary to 2684 support PC/104 devices on X86_64 platforms. 2685 2686 If unsure, say N. 2687 2688# x86_64 have no ISA slots, but can have ISA-style DMA. 2689config ISA_DMA_API 2690 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2691 default y 2692 help 2693 Enables ISA-style DMA support for devices requiring such controllers. 2694 If unsure, say Y. 2695 2696if X86_32 2697 2698config ISA 2699 bool "ISA support" 2700 ---help--- 2701 Find out whether you have ISA slots on your motherboard. ISA is the 2702 name of a bus system, i.e. the way the CPU talks to the other stuff 2703 inside your box. Other bus systems are PCI, EISA, MicroChannel 2704 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2705 newer boards don't support it. If you have ISA, say Y, otherwise N. 2706 2707config EISA 2708 bool "EISA support" 2709 depends on ISA 2710 ---help--- 2711 The Extended Industry Standard Architecture (EISA) bus was 2712 developed as an open alternative to the IBM MicroChannel bus. 2713 2714 The EISA bus provided some of the features of the IBM MicroChannel 2715 bus while maintaining backward compatibility with cards made for 2716 the older ISA bus. The EISA bus saw limited use between 1988 and 2717 1995 when it was made obsolete by the PCI bus. 2718 2719 Say Y here if you are building a kernel for an EISA-based machine. 2720 2721 Otherwise, say N. 2722 2723source "drivers/eisa/Kconfig" 2724 2725config SCx200 2726 tristate "NatSemi SCx200 support" 2727 ---help--- 2728 This provides basic support for National Semiconductor's 2729 (now AMD's) Geode processors. The driver probes for the 2730 PCI-IDs of several on-chip devices, so its a good dependency 2731 for other scx200_* drivers. 2732 2733 If compiled as a module, the driver is named scx200. 2734 2735config SCx200HR_TIMER 2736 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2737 depends on SCx200 2738 default y 2739 ---help--- 2740 This driver provides a clocksource built upon the on-chip 2741 27MHz high-resolution timer. Its also a workaround for 2742 NSC Geode SC-1100's buggy TSC, which loses time when the 2743 processor goes idle (as is done by the scheduler). The 2744 other workaround is idle=poll boot option. 2745 2746config OLPC 2747 bool "One Laptop Per Child support" 2748 depends on !X86_PAE 2749 select GPIOLIB 2750 select OF 2751 select OF_PROMTREE 2752 select IRQ_DOMAIN 2753 ---help--- 2754 Add support for detecting the unique features of the OLPC 2755 XO hardware. 2756 2757config OLPC_XO1_PM 2758 bool "OLPC XO-1 Power Management" 2759 depends on OLPC && MFD_CS5535 && PM_SLEEP 2760 select MFD_CORE 2761 ---help--- 2762 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2763 2764config OLPC_XO1_RTC 2765 bool "OLPC XO-1 Real Time Clock" 2766 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2767 ---help--- 2768 Add support for the XO-1 real time clock, which can be used as a 2769 programmable wakeup source. 2770 2771config OLPC_XO1_SCI 2772 bool "OLPC XO-1 SCI extras" 2773 depends on OLPC && OLPC_XO1_PM 2774 depends on INPUT=y 2775 select POWER_SUPPLY 2776 select GPIO_CS5535 2777 select MFD_CORE 2778 ---help--- 2779 Add support for SCI-based features of the OLPC XO-1 laptop: 2780 - EC-driven system wakeups 2781 - Power button 2782 - Ebook switch 2783 - Lid switch 2784 - AC adapter status updates 2785 - Battery status updates 2786 2787config OLPC_XO15_SCI 2788 bool "OLPC XO-1.5 SCI extras" 2789 depends on OLPC && ACPI 2790 select POWER_SUPPLY 2791 ---help--- 2792 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2793 - EC-driven system wakeups 2794 - AC adapter status updates 2795 - Battery status updates 2796 2797config ALIX 2798 bool "PCEngines ALIX System Support (LED setup)" 2799 select GPIOLIB 2800 ---help--- 2801 This option enables system support for the PCEngines ALIX. 2802 At present this just sets up LEDs for GPIO control on 2803 ALIX2/3/6 boards. However, other system specific setup should 2804 get added here. 2805 2806 Note: You must still enable the drivers for GPIO and LED support 2807 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2808 2809 Note: You have to set alix.force=1 for boards with Award BIOS. 2810 2811config NET5501 2812 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2813 select GPIOLIB 2814 ---help--- 2815 This option enables system support for the Soekris Engineering net5501. 2816 2817config GEOS 2818 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2819 select GPIOLIB 2820 depends on DMI 2821 ---help--- 2822 This option enables system support for the Traverse Technologies GEOS. 2823 2824config TS5500 2825 bool "Technologic Systems TS-5500 platform support" 2826 depends on MELAN 2827 select CHECK_SIGNATURE 2828 select NEW_LEDS 2829 select LEDS_CLASS 2830 ---help--- 2831 This option enables system support for the Technologic Systems TS-5500. 2832 2833endif # X86_32 2834 2835config AMD_NB 2836 def_bool y 2837 depends on CPU_SUP_AMD && PCI 2838 2839source "drivers/pcmcia/Kconfig" 2840 2841config RAPIDIO 2842 tristate "RapidIO support" 2843 depends on PCI 2844 default n 2845 help 2846 If enabled this option will include drivers and the core 2847 infrastructure code to support RapidIO interconnect devices. 2848 2849source "drivers/rapidio/Kconfig" 2850 2851config X86_SYSFB 2852 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2853 help 2854 Firmwares often provide initial graphics framebuffers so the BIOS, 2855 bootloader or kernel can show basic video-output during boot for 2856 user-guidance and debugging. Historically, x86 used the VESA BIOS 2857 Extensions and EFI-framebuffers for this, which are mostly limited 2858 to x86. 2859 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2860 framebuffers so the new generic system-framebuffer drivers can be 2861 used on x86. If the framebuffer is not compatible with the generic 2862 modes, it is adverticed as fallback platform framebuffer so legacy 2863 drivers like efifb, vesafb and uvesafb can pick it up. 2864 If this option is not selected, all system framebuffers are always 2865 marked as fallback platform framebuffers as usual. 2866 2867 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2868 not be able to pick up generic system framebuffers if this option 2869 is selected. You are highly encouraged to enable simplefb as 2870 replacement if you select this option. simplefb can correctly deal 2871 with generic system framebuffers. But you should still keep vesafb 2872 and others enabled as fallback if a system framebuffer is 2873 incompatible with simplefb. 2874 2875 If unsure, say Y. 2876 2877endmenu 2878 2879 2880menu "Executable file formats / Emulations" 2881 2882source "fs/Kconfig.binfmt" 2883 2884config IA32_EMULATION 2885 bool "IA32 Emulation" 2886 depends on X86_64 2887 select ARCH_WANT_OLD_COMPAT_IPC 2888 select BINFMT_ELF 2889 select COMPAT_BINFMT_ELF 2890 select COMPAT_OLD_SIGACTION 2891 ---help--- 2892 Include code to run legacy 32-bit programs under a 2893 64-bit kernel. You should likely turn this on, unless you're 2894 100% sure that you don't have any 32-bit programs left. 2895 2896config IA32_AOUT 2897 tristate "IA32 a.out support" 2898 depends on IA32_EMULATION 2899 ---help--- 2900 Support old a.out binaries in the 32bit emulation. 2901 2902config X86_X32 2903 bool "x32 ABI for 64-bit mode" 2904 depends on X86_64 2905 ---help--- 2906 Include code to run binaries for the x32 native 32-bit ABI 2907 for 64-bit processors. An x32 process gets access to the 2908 full 64-bit register file and wide data path while leaving 2909 pointers at 32 bits for smaller memory footprint. 2910 2911 You will need a recent binutils (2.22 or later) with 2912 elf32_x86_64 support enabled to compile a kernel with this 2913 option set. 2914 2915config COMPAT_32 2916 def_bool y 2917 depends on IA32_EMULATION || X86_32 2918 select HAVE_UID16 2919 select OLD_SIGSUSPEND3 2920 2921config COMPAT 2922 def_bool y 2923 depends on IA32_EMULATION || X86_X32 2924 2925if COMPAT 2926config COMPAT_FOR_U64_ALIGNMENT 2927 def_bool y 2928 2929config SYSVIPC_COMPAT 2930 def_bool y 2931 depends on SYSVIPC 2932endif 2933 2934endmenu 2935 2936 2937config HAVE_ATOMIC_IOMAP 2938 def_bool y 2939 depends on X86_32 2940 2941config X86_DEV_DMA_OPS 2942 bool 2943 depends on X86_64 || STA2X11 2944 2945config X86_DMA_REMAP 2946 bool 2947 depends on STA2X11 2948 2949config HAVE_GENERIC_GUP 2950 def_bool y 2951 2952source "net/Kconfig" 2953 2954source "drivers/Kconfig" 2955 2956source "drivers/firmware/Kconfig" 2957 2958source "fs/Kconfig" 2959 2960source "arch/x86/Kconfig.debug" 2961 2962source "security/Kconfig" 2963 2964source "crypto/Kconfig" 2965 2966source "arch/x86/kvm/Kconfig" 2967 2968source "lib/Kconfig" 2969