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 select ARCH_HAS_SYSCALL_WRAPPER 33 34# 35# Arch settings 36# 37# ( Note that options that are marked 'if X86_64' could in principle be 38# ported to 32-bit as well. ) 39# 40config X86 41 def_bool y 42 # 43 # Note: keep this list sorted alphabetically 44 # 45 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 46 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 47 select ANON_INODES 48 select ARCH_CLOCKSOURCE_DATA 49 select ARCH_DISCARD_MEMBLOCK 50 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 51 select ARCH_HAS_DEBUG_VIRTUAL 52 select ARCH_HAS_DEVMEM_IS_ALLOWED 53 select ARCH_HAS_ELF_RANDOMIZE 54 select ARCH_HAS_FAST_MULTIPLIER 55 select ARCH_HAS_FORTIFY_SOURCE 56 select ARCH_HAS_GCOV_PROFILE_ALL 57 select ARCH_HAS_KCOV if X86_64 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 DMA_DIRECT_OPS 87 select EDAC_ATOMIC_SCRUB 88 select EDAC_SUPPORT 89 select GENERIC_CLOCKEVENTS 90 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 91 select GENERIC_CLOCKEVENTS_MIN_ADJUST 92 select GENERIC_CMOS_UPDATE 93 select GENERIC_CPU_AUTOPROBE 94 select GENERIC_CPU_VULNERABILITIES 95 select GENERIC_EARLY_IOREMAP 96 select GENERIC_FIND_FIRST_BIT 97 select GENERIC_IOMAP 98 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 99 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 100 select GENERIC_IRQ_MIGRATION if SMP 101 select GENERIC_IRQ_PROBE 102 select GENERIC_IRQ_RESERVATION_MODE 103 select GENERIC_IRQ_SHOW 104 select GENERIC_PENDING_IRQ if SMP 105 select GENERIC_SMP_IDLE_THREAD 106 select GENERIC_STRNCPY_FROM_USER 107 select GENERIC_STRNLEN_USER 108 select GENERIC_TIME_VSYSCALL 109 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 110 select HAVE_ACPI_APEI if ACPI 111 select HAVE_ACPI_APEI_NMI if ACPI 112 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 113 select HAVE_ARCH_AUDITSYSCALL 114 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 115 select HAVE_ARCH_JUMP_LABEL 116 select HAVE_ARCH_KASAN if X86_64 117 select HAVE_ARCH_KGDB 118 select HAVE_ARCH_MMAP_RND_BITS if MMU 119 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 120 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 121 select HAVE_ARCH_SECCOMP_FILTER 122 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 123 select HAVE_ARCH_TRACEHOOK 124 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 125 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 126 select HAVE_ARCH_VMAP_STACK if X86_64 127 select HAVE_ARCH_WITHIN_STACK_FRAMES 128 select HAVE_CC_STACKPROTECTOR 129 select HAVE_CMPXCHG_DOUBLE 130 select HAVE_CMPXCHG_LOCAL 131 select HAVE_CONTEXT_TRACKING if X86_64 132 select HAVE_COPY_THREAD_TLS 133 select HAVE_C_RECORDMCOUNT 134 select HAVE_DEBUG_KMEMLEAK 135 select HAVE_DEBUG_STACKOVERFLOW 136 select HAVE_DMA_API_DEBUG 137 select HAVE_DMA_CONTIGUOUS 138 select HAVE_DYNAMIC_FTRACE 139 select HAVE_DYNAMIC_FTRACE_WITH_REGS 140 select HAVE_EBPF_JIT if X86_64 141 select HAVE_EFFICIENT_UNALIGNED_ACCESS 142 select HAVE_EXIT_THREAD 143 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 144 select HAVE_FTRACE_MCOUNT_RECORD 145 select HAVE_FUNCTION_GRAPH_TRACER 146 select HAVE_FUNCTION_TRACER 147 select HAVE_GCC_PLUGINS 148 select HAVE_HW_BREAKPOINT 149 select HAVE_IDE 150 select HAVE_IOREMAP_PROT 151 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 152 select HAVE_IRQ_TIME_ACCOUNTING 153 select HAVE_KERNEL_BZIP2 154 select HAVE_KERNEL_GZIP 155 select HAVE_KERNEL_LZ4 156 select HAVE_KERNEL_LZMA 157 select HAVE_KERNEL_LZO 158 select HAVE_KERNEL_XZ 159 select HAVE_KPROBES 160 select HAVE_KPROBES_ON_FTRACE 161 select HAVE_FUNCTION_ERROR_INJECTION 162 select HAVE_KRETPROBES 163 select HAVE_KVM 164 select HAVE_LIVEPATCH if X86_64 165 select HAVE_MEMBLOCK 166 select HAVE_MEMBLOCK_NODE_MAP 167 select HAVE_MIXED_BREAKPOINTS_REGS 168 select HAVE_MOD_ARCH_SPECIFIC 169 select HAVE_NMI 170 select HAVE_OPROFILE 171 select HAVE_OPTPROBES 172 select HAVE_PCSPKR_PLATFORM 173 select HAVE_PERF_EVENTS 174 select HAVE_PERF_EVENTS_NMI 175 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 176 select HAVE_PERF_REGS 177 select HAVE_PERF_USER_STACK_DUMP 178 select HAVE_RCU_TABLE_FREE 179 select HAVE_REGS_AND_STACK_ACCESS_API 180 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 181 select HAVE_STACK_VALIDATION if X86_64 182 select HAVE_SYSCALL_TRACEPOINTS 183 select HAVE_UNSTABLE_SCHED_CLOCK 184 select HAVE_USER_RETURN_NOTIFIER 185 select IRQ_FORCED_THREADING 186 select PCI_LOCKLESS_CONFIG 187 select PERF_EVENTS 188 select RTC_LIB 189 select RTC_MC146818_LIB 190 select SPARSE_IRQ 191 select SRCU 192 select SYSCTL_EXCEPTION_TRACE 193 select THREAD_INFO_IN_TASK 194 select USER_STACKTRACE_SUPPORT 195 select VIRT_TO_BUS 196 select X86_FEATURE_NAMES if PROC_FS 197 198config INSTRUCTION_DECODER 199 def_bool y 200 depends on KPROBES || PERF_EVENTS || UPROBES 201 202config OUTPUT_FORMAT 203 string 204 default "elf32-i386" if X86_32 205 default "elf64-x86-64" if X86_64 206 207config ARCH_DEFCONFIG 208 string 209 default "arch/x86/configs/i386_defconfig" if X86_32 210 default "arch/x86/configs/x86_64_defconfig" if X86_64 211 212config LOCKDEP_SUPPORT 213 def_bool y 214 215config STACKTRACE_SUPPORT 216 def_bool y 217 218config MMU 219 def_bool y 220 221config ARCH_MMAP_RND_BITS_MIN 222 default 28 if 64BIT 223 default 8 224 225config ARCH_MMAP_RND_BITS_MAX 226 default 32 if 64BIT 227 default 16 228 229config ARCH_MMAP_RND_COMPAT_BITS_MIN 230 default 8 231 232config ARCH_MMAP_RND_COMPAT_BITS_MAX 233 default 16 234 235config SBUS 236 bool 237 238config NEED_DMA_MAP_STATE 239 def_bool y 240 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 241 242config NEED_SG_DMA_LENGTH 243 def_bool y 244 245config GENERIC_ISA_DMA 246 def_bool y 247 depends on ISA_DMA_API 248 249config GENERIC_BUG 250 def_bool y 251 depends on BUG 252 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 253 254config GENERIC_BUG_RELATIVE_POINTERS 255 bool 256 257config GENERIC_HWEIGHT 258 def_bool y 259 260config ARCH_MAY_HAVE_PC_FDC 261 def_bool y 262 depends on ISA_DMA_API 263 264config RWSEM_XCHGADD_ALGORITHM 265 def_bool y 266 267config GENERIC_CALIBRATE_DELAY 268 def_bool y 269 270config ARCH_HAS_CPU_RELAX 271 def_bool y 272 273config ARCH_HAS_CACHE_LINE_SIZE 274 def_bool y 275 276config HAVE_SETUP_PER_CPU_AREA 277 def_bool y 278 279config NEED_PER_CPU_EMBED_FIRST_CHUNK 280 def_bool y 281 282config NEED_PER_CPU_PAGE_FIRST_CHUNK 283 def_bool y 284 285config ARCH_HIBERNATION_POSSIBLE 286 def_bool y 287 288config ARCH_SUSPEND_POSSIBLE 289 def_bool y 290 291config ARCH_WANT_HUGE_PMD_SHARE 292 def_bool y 293 294config ARCH_WANT_GENERAL_HUGETLB 295 def_bool y 296 297config ZONE_DMA32 298 def_bool y if X86_64 299 300config AUDIT_ARCH 301 def_bool y if X86_64 302 303config ARCH_SUPPORTS_OPTIMIZED_INLINING 304 def_bool y 305 306config ARCH_SUPPORTS_DEBUG_PAGEALLOC 307 def_bool y 308 309config KASAN_SHADOW_OFFSET 310 hex 311 depends on KASAN 312 default 0xdffffc0000000000 313 314config HAVE_INTEL_TXT 315 def_bool y 316 depends on INTEL_IOMMU && ACPI 317 318config X86_32_SMP 319 def_bool y 320 depends on X86_32 && SMP 321 322config X86_64_SMP 323 def_bool y 324 depends on X86_64 && SMP 325 326config X86_32_LAZY_GS 327 def_bool y 328 depends on X86_32 && CC_STACKPROTECTOR_NONE 329 330config ARCH_SUPPORTS_UPROBES 331 def_bool y 332 333config FIX_EARLYCON_MEM 334 def_bool y 335 336config PGTABLE_LEVELS 337 int 338 default 5 if X86_5LEVEL 339 default 4 if X86_64 340 default 3 if X86_PAE 341 default 2 342 343source "init/Kconfig" 344source "kernel/Kconfig.freezer" 345 346menu "Processor type and features" 347 348config ZONE_DMA 349 bool "DMA memory allocation support" if EXPERT 350 default y 351 help 352 DMA memory allocation support allows devices with less than 32-bit 353 addressing to allocate within the first 16MB of address space. 354 Disable if no such devices will be used. 355 356 If unsure, say Y. 357 358config SMP 359 bool "Symmetric multi-processing support" 360 ---help--- 361 This enables support for systems with more than one CPU. If you have 362 a system with only one CPU, say N. If you have a system with more 363 than one CPU, say Y. 364 365 If you say N here, the kernel will run on uni- and multiprocessor 366 machines, but will use only one CPU of a multiprocessor machine. If 367 you say Y here, the kernel will run on many, but not all, 368 uniprocessor machines. On a uniprocessor machine, the kernel 369 will run faster if you say N here. 370 371 Note that if you say Y here and choose architecture "586" or 372 "Pentium" under "Processor family", the kernel will not work on 486 373 architectures. Similarly, multiprocessor kernels for the "PPro" 374 architecture may not work on all Pentium based boards. 375 376 People using multiprocessor machines who say Y here should also say 377 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 378 Management" code will be disabled if you say Y here. 379 380 See also <file:Documentation/x86/i386/IO-APIC.txt>, 381 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 382 <http://www.tldp.org/docs.html#howto>. 383 384 If you don't know what to do here, say N. 385 386config X86_FEATURE_NAMES 387 bool "Processor feature human-readable names" if EMBEDDED 388 default y 389 ---help--- 390 This option compiles in a table of x86 feature bits and corresponding 391 names. This is required to support /proc/cpuinfo and a few kernel 392 messages. You can disable this to save space, at the expense of 393 making those few kernel messages show numeric feature bits instead. 394 395 If in doubt, say Y. 396 397config X86_X2APIC 398 bool "Support x2apic" 399 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 400 ---help--- 401 This enables x2apic support on CPUs that have this feature. 402 403 This allows 32-bit apic IDs (so it can support very large systems), 404 and accesses the local apic via MSRs not via mmio. 405 406 If you don't know what to do here, say N. 407 408config X86_MPPARSE 409 bool "Enable MPS table" if ACPI || SFI 410 default y 411 depends on X86_LOCAL_APIC 412 ---help--- 413 For old smp systems that do not have proper acpi support. Newer systems 414 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 415 416config GOLDFISH 417 def_bool y 418 depends on X86_GOLDFISH 419 420config RETPOLINE 421 bool "Avoid speculative indirect branches in kernel" 422 default y 423 select STACK_VALIDATION if HAVE_STACK_VALIDATION 424 help 425 Compile kernel with the retpoline compiler options to guard against 426 kernel-to-user data leaks by avoiding speculative indirect 427 branches. Requires a compiler with -mindirect-branch=thunk-extern 428 support for full protection. The kernel may run slower. 429 430 Without compiler support, at least indirect branches in assembler 431 code are eliminated. Since this includes the syscall entry path, 432 it is not entirely pointless. 433 434config INTEL_RDT 435 bool "Intel Resource Director Technology support" 436 default n 437 depends on X86 && CPU_SUP_INTEL 438 select KERNFS 439 help 440 Select to enable resource allocation and monitoring which are 441 sub-features of Intel Resource Director Technology(RDT). More 442 information about RDT can be found in the Intel x86 443 Architecture Software Developer Manual. 444 445 Say N if unsure. 446 447if X86_32 448config X86_BIGSMP 449 bool "Support for big SMP systems with more than 8 CPUs" 450 depends on SMP 451 ---help--- 452 This option is needed for the systems that have more than 8 CPUs 453 454config X86_EXTENDED_PLATFORM 455 bool "Support for extended (non-PC) x86 platforms" 456 default y 457 ---help--- 458 If you disable this option then the kernel will only support 459 standard PC platforms. (which covers the vast majority of 460 systems out there.) 461 462 If you enable this option then you'll be able to select support 463 for the following (non-PC) 32 bit x86 platforms: 464 Goldfish (Android emulator) 465 AMD Elan 466 RDC R-321x SoC 467 SGI 320/540 (Visual Workstation) 468 STA2X11-based (e.g. Northville) 469 Moorestown MID devices 470 471 If you have one of these systems, or if you want to build a 472 generic distribution kernel, say Y here - otherwise say N. 473endif 474 475if X86_64 476config X86_EXTENDED_PLATFORM 477 bool "Support for extended (non-PC) x86 platforms" 478 default y 479 ---help--- 480 If you disable this option then the kernel will only support 481 standard PC platforms. (which covers the vast majority of 482 systems out there.) 483 484 If you enable this option then you'll be able to select support 485 for the following (non-PC) 64 bit x86 platforms: 486 Numascale NumaChip 487 ScaleMP vSMP 488 SGI Ultraviolet 489 490 If you have one of these systems, or if you want to build a 491 generic distribution kernel, say Y here - otherwise say N. 492endif 493# This is an alphabetically sorted list of 64 bit extended platforms 494# Please maintain the alphabetic order if and when there are additions 495config X86_NUMACHIP 496 bool "Numascale NumaChip" 497 depends on X86_64 498 depends on X86_EXTENDED_PLATFORM 499 depends on NUMA 500 depends on SMP 501 depends on X86_X2APIC 502 depends on PCI_MMCONFIG 503 ---help--- 504 Adds support for Numascale NumaChip large-SMP systems. Needed to 505 enable more than ~168 cores. 506 If you don't have one of these, you should say N here. 507 508config X86_VSMP 509 bool "ScaleMP vSMP" 510 select HYPERVISOR_GUEST 511 select PARAVIRT 512 depends on X86_64 && PCI 513 depends on X86_EXTENDED_PLATFORM 514 depends on SMP 515 ---help--- 516 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 517 supposed to run on these EM64T-based machines. Only choose this option 518 if you have one of these machines. 519 520config X86_UV 521 bool "SGI Ultraviolet" 522 depends on X86_64 523 depends on X86_EXTENDED_PLATFORM 524 depends on NUMA 525 depends on EFI 526 depends on X86_X2APIC 527 depends on PCI 528 ---help--- 529 This option is needed in order to support SGI Ultraviolet systems. 530 If you don't have one of these, you should say N here. 531 532# Following is an alphabetically sorted list of 32 bit extended platforms 533# Please maintain the alphabetic order if and when there are additions 534 535config X86_GOLDFISH 536 bool "Goldfish (Virtual Platform)" 537 depends on X86_EXTENDED_PLATFORM 538 ---help--- 539 Enable support for the Goldfish virtual platform used primarily 540 for Android development. Unless you are building for the Android 541 Goldfish emulator say N here. 542 543config X86_INTEL_CE 544 bool "CE4100 TV platform" 545 depends on PCI 546 depends on PCI_GODIRECT 547 depends on X86_IO_APIC 548 depends on X86_32 549 depends on X86_EXTENDED_PLATFORM 550 select X86_REBOOTFIXUPS 551 select OF 552 select OF_EARLY_FLATTREE 553 ---help--- 554 Select for the Intel CE media processor (CE4100) SOC. 555 This option compiles in support for the CE4100 SOC for settop 556 boxes and media devices. 557 558config X86_INTEL_MID 559 bool "Intel MID platform support" 560 depends on X86_EXTENDED_PLATFORM 561 depends on X86_PLATFORM_DEVICES 562 depends on PCI 563 depends on X86_64 || (PCI_GOANY && X86_32) 564 depends on X86_IO_APIC 565 select SFI 566 select I2C 567 select DW_APB_TIMER 568 select APB_TIMER 569 select INTEL_SCU_IPC 570 select MFD_INTEL_MSIC 571 ---help--- 572 Select to build a kernel capable of supporting Intel MID (Mobile 573 Internet Device) platform systems which do not have the PCI legacy 574 interfaces. If you are building for a PC class system say N here. 575 576 Intel MID platforms are based on an Intel processor and chipset which 577 consume less power than most of the x86 derivatives. 578 579config X86_INTEL_QUARK 580 bool "Intel Quark platform support" 581 depends on X86_32 582 depends on X86_EXTENDED_PLATFORM 583 depends on X86_PLATFORM_DEVICES 584 depends on X86_TSC 585 depends on PCI 586 depends on PCI_GOANY 587 depends on X86_IO_APIC 588 select IOSF_MBI 589 select INTEL_IMR 590 select COMMON_CLK 591 ---help--- 592 Select to include support for Quark X1000 SoC. 593 Say Y here if you have a Quark based system such as the Arduino 594 compatible Intel Galileo. 595 596config X86_INTEL_LPSS 597 bool "Intel Low Power Subsystem Support" 598 depends on X86 && ACPI 599 select COMMON_CLK 600 select PINCTRL 601 select IOSF_MBI 602 ---help--- 603 Select to build support for Intel Low Power Subsystem such as 604 found on Intel Lynxpoint PCH. Selecting this option enables 605 things like clock tree (common clock framework) and pincontrol 606 which are needed by the LPSS peripheral drivers. 607 608config X86_AMD_PLATFORM_DEVICE 609 bool "AMD ACPI2Platform devices support" 610 depends on ACPI 611 select COMMON_CLK 612 select PINCTRL 613 ---help--- 614 Select to interpret AMD specific ACPI device to platform device 615 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 616 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 617 implemented under PINCTRL subsystem. 618 619config IOSF_MBI 620 tristate "Intel SoC IOSF Sideband support for SoC platforms" 621 depends on PCI 622 ---help--- 623 This option enables sideband register access support for Intel SoC 624 platforms. On these platforms the IOSF sideband is used in lieu of 625 MSR's for some register accesses, mostly but not limited to thermal 626 and power. Drivers may query the availability of this device to 627 determine if they need the sideband in order to work on these 628 platforms. The sideband is available on the following SoC products. 629 This list is not meant to be exclusive. 630 - BayTrail 631 - Braswell 632 - Quark 633 634 You should say Y if you are running a kernel on one of these SoC's. 635 636config IOSF_MBI_DEBUG 637 bool "Enable IOSF sideband access through debugfs" 638 depends on IOSF_MBI && DEBUG_FS 639 ---help--- 640 Select this option to expose the IOSF sideband access registers (MCR, 641 MDR, MCRX) through debugfs to write and read register information from 642 different units on the SoC. This is most useful for obtaining device 643 state information for debug and analysis. As this is a general access 644 mechanism, users of this option would have specific knowledge of the 645 device they want to access. 646 647 If you don't require the option or are in doubt, say N. 648 649config X86_RDC321X 650 bool "RDC R-321x SoC" 651 depends on X86_32 652 depends on X86_EXTENDED_PLATFORM 653 select M486 654 select X86_REBOOTFIXUPS 655 ---help--- 656 This option is needed for RDC R-321x system-on-chip, also known 657 as R-8610-(G). 658 If you don't have one of these chips, you should say N here. 659 660config X86_32_NON_STANDARD 661 bool "Support non-standard 32-bit SMP architectures" 662 depends on X86_32 && SMP 663 depends on X86_EXTENDED_PLATFORM 664 ---help--- 665 This option compiles in the bigsmp and STA2X11 default 666 subarchitectures. It is intended for a generic binary 667 kernel. If you select them all, kernel will probe it one by 668 one and will fallback to default. 669 670# Alphabetically sorted list of Non standard 32 bit platforms 671 672config X86_SUPPORTS_MEMORY_FAILURE 673 def_bool y 674 # MCE code calls memory_failure(): 675 depends on X86_MCE 676 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 677 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 678 depends on X86_64 || !SPARSEMEM 679 select ARCH_SUPPORTS_MEMORY_FAILURE 680 681config STA2X11 682 bool "STA2X11 Companion Chip Support" 683 depends on X86_32_NON_STANDARD && PCI 684 select ARCH_HAS_PHYS_TO_DMA 685 select X86_DEV_DMA_OPS 686 select X86_DMA_REMAP 687 select SWIOTLB 688 select MFD_STA2X11 689 select GPIOLIB 690 default n 691 ---help--- 692 This adds support for boards based on the STA2X11 IO-Hub, 693 a.k.a. "ConneXt". The chip is used in place of the standard 694 PC chipset, so all "standard" peripherals are missing. If this 695 option is selected the kernel will still be able to boot on 696 standard PC machines. 697 698config X86_32_IRIS 699 tristate "Eurobraille/Iris poweroff module" 700 depends on X86_32 701 ---help--- 702 The Iris machines from EuroBraille do not have APM or ACPI support 703 to shut themselves down properly. A special I/O sequence is 704 needed to do so, which is what this module does at 705 kernel shutdown. 706 707 This is only for Iris machines from EuroBraille. 708 709 If unused, say N. 710 711config SCHED_OMIT_FRAME_POINTER 712 def_bool y 713 prompt "Single-depth WCHAN output" 714 depends on X86 715 ---help--- 716 Calculate simpler /proc/<PID>/wchan values. If this option 717 is disabled then wchan values will recurse back to the 718 caller function. This provides more accurate wchan values, 719 at the expense of slightly more scheduling overhead. 720 721 If in doubt, say "Y". 722 723menuconfig HYPERVISOR_GUEST 724 bool "Linux guest support" 725 ---help--- 726 Say Y here to enable options for running Linux under various hyper- 727 visors. This option enables basic hypervisor detection and platform 728 setup. 729 730 If you say N, all options in this submenu will be skipped and 731 disabled, and Linux guest support won't be built in. 732 733if HYPERVISOR_GUEST 734 735config PARAVIRT 736 bool "Enable paravirtualization code" 737 ---help--- 738 This changes the kernel so it can modify itself when it is run 739 under a hypervisor, potentially improving performance significantly 740 over full virtualization. However, when run without a hypervisor 741 the kernel is theoretically slower and slightly larger. 742 743config PARAVIRT_DEBUG 744 bool "paravirt-ops debugging" 745 depends on PARAVIRT && DEBUG_KERNEL 746 ---help--- 747 Enable to debug paravirt_ops internals. Specifically, BUG if 748 a paravirt_op is missing when it is called. 749 750config PARAVIRT_SPINLOCKS 751 bool "Paravirtualization layer for spinlocks" 752 depends on PARAVIRT && SMP 753 ---help--- 754 Paravirtualized spinlocks allow a pvops backend to replace the 755 spinlock implementation with something virtualization-friendly 756 (for example, block the virtual CPU rather than spinning). 757 758 It has a minimal impact on native kernels and gives a nice performance 759 benefit on paravirtualized KVM / Xen kernels. 760 761 If you are unsure how to answer this question, answer Y. 762 763config QUEUED_LOCK_STAT 764 bool "Paravirt queued spinlock statistics" 765 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 766 ---help--- 767 Enable the collection of statistical data on the slowpath 768 behavior of paravirtualized queued spinlocks and report 769 them on debugfs. 770 771source "arch/x86/xen/Kconfig" 772 773config KVM_GUEST 774 bool "KVM Guest support (including kvmclock)" 775 depends on PARAVIRT 776 select PARAVIRT_CLOCK 777 default y 778 ---help--- 779 This option enables various optimizations for running under the KVM 780 hypervisor. It includes a paravirtualized clock, so that instead 781 of relying on a PIT (or probably other) emulation by the 782 underlying device model, the host provides the guest with 783 timing infrastructure such as time of day, and system time 784 785config KVM_DEBUG_FS 786 bool "Enable debug information for KVM Guests in debugfs" 787 depends on KVM_GUEST && DEBUG_FS 788 default n 789 ---help--- 790 This option enables collection of various statistics for KVM guest. 791 Statistics are displayed in debugfs filesystem. Enabling this option 792 may incur significant overhead. 793 794config PARAVIRT_TIME_ACCOUNTING 795 bool "Paravirtual steal time accounting" 796 depends on PARAVIRT 797 default n 798 ---help--- 799 Select this option to enable fine granularity task steal time 800 accounting. Time spent executing other tasks in parallel with 801 the current vCPU is discounted from the vCPU power. To account for 802 that, there can be a small performance impact. 803 804 If in doubt, say N here. 805 806config PARAVIRT_CLOCK 807 bool 808 809config JAILHOUSE_GUEST 810 bool "Jailhouse non-root cell support" 811 depends on X86_64 && PCI 812 select X86_PM_TIMER 813 ---help--- 814 This option allows to run Linux as guest in a Jailhouse non-root 815 cell. You can leave this option disabled if you only want to start 816 Jailhouse and run Linux afterwards in the root cell. 817 818endif #HYPERVISOR_GUEST 819 820config NO_BOOTMEM 821 def_bool y 822 823source "arch/x86/Kconfig.cpu" 824 825config HPET_TIMER 826 def_bool X86_64 827 prompt "HPET Timer Support" if X86_32 828 ---help--- 829 Use the IA-PC HPET (High Precision Event Timer) to manage 830 time in preference to the PIT and RTC, if a HPET is 831 present. 832 HPET is the next generation timer replacing legacy 8254s. 833 The HPET provides a stable time base on SMP 834 systems, unlike the TSC, but it is more expensive to access, 835 as it is off-chip. The interface used is documented 836 in the HPET spec, revision 1. 837 838 You can safely choose Y here. However, HPET will only be 839 activated if the platform and the BIOS support this feature. 840 Otherwise the 8254 will be used for timing services. 841 842 Choose N to continue using the legacy 8254 timer. 843 844config HPET_EMULATE_RTC 845 def_bool y 846 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 847 848config APB_TIMER 849 def_bool y if X86_INTEL_MID 850 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 851 select DW_APB_TIMER 852 depends on X86_INTEL_MID && SFI 853 help 854 APB timer is the replacement for 8254, HPET on X86 MID platforms. 855 The APBT provides a stable time base on SMP 856 systems, unlike the TSC, but it is more expensive to access, 857 as it is off-chip. APB timers are always running regardless of CPU 858 C states, they are used as per CPU clockevent device when possible. 859 860# Mark as expert because too many people got it wrong. 861# The code disables itself when not needed. 862config DMI 863 default y 864 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 865 bool "Enable DMI scanning" if EXPERT 866 ---help--- 867 Enabled scanning of DMI to identify machine quirks. Say Y 868 here unless you have verified that your setup is not 869 affected by entries in the DMI blacklist. Required by PNP 870 BIOS code. 871 872config GART_IOMMU 873 bool "Old AMD GART IOMMU support" 874 select SWIOTLB 875 depends on X86_64 && PCI && AMD_NB 876 ---help--- 877 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 878 GART based hardware IOMMUs. 879 880 The GART supports full DMA access for devices with 32-bit access 881 limitations, on systems with more than 3 GB. This is usually needed 882 for USB, sound, many IDE/SATA chipsets and some other devices. 883 884 Newer systems typically have a modern AMD IOMMU, supported via 885 the CONFIG_AMD_IOMMU=y config option. 886 887 In normal configurations this driver is only active when needed: 888 there's more than 3 GB of memory and the system contains a 889 32-bit limited device. 890 891 If unsure, say Y. 892 893config CALGARY_IOMMU 894 bool "IBM Calgary IOMMU support" 895 select SWIOTLB 896 depends on X86_64 && PCI 897 ---help--- 898 Support for hardware IOMMUs in IBM's xSeries x366 and x460 899 systems. Needed to run systems with more than 3GB of memory 900 properly with 32-bit PCI devices that do not support DAC 901 (Double Address Cycle). Calgary also supports bus level 902 isolation, where all DMAs pass through the IOMMU. This 903 prevents them from going anywhere except their intended 904 destination. This catches hard-to-find kernel bugs and 905 mis-behaving drivers and devices that do not use the DMA-API 906 properly to set up their DMA buffers. The IOMMU can be 907 turned off at boot time with the iommu=off parameter. 908 Normally the kernel will make the right choice by itself. 909 If unsure, say Y. 910 911config CALGARY_IOMMU_ENABLED_BY_DEFAULT 912 def_bool y 913 prompt "Should Calgary be enabled by default?" 914 depends on CALGARY_IOMMU 915 ---help--- 916 Should Calgary be enabled by default? if you choose 'y', Calgary 917 will be used (if it exists). If you choose 'n', Calgary will not be 918 used even if it exists. If you choose 'n' and would like to use 919 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 920 If unsure, say Y. 921 922# need this always selected by IOMMU for the VIA workaround 923config SWIOTLB 924 def_bool y if X86_64 925 ---help--- 926 Support for software bounce buffers used on x86-64 systems 927 which don't have a hardware IOMMU. Using this PCI devices 928 which can only access 32-bits of memory can be used on systems 929 with more than 3 GB of memory. 930 If unsure, say Y. 931 932config IOMMU_HELPER 933 def_bool y 934 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 935 936config MAXSMP 937 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 938 depends on X86_64 && SMP && DEBUG_KERNEL 939 select CPUMASK_OFFSTACK 940 ---help--- 941 Enable maximum number of CPUS and NUMA Nodes for this architecture. 942 If unsure, say N. 943 944# 945# The maximum number of CPUs supported: 946# 947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 948# and which can be configured interactively in the 949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 950# 951# The ranges are different on 32-bit and 64-bit kernels, depending on 952# hardware capabilities and scalability features of the kernel. 953# 954# ( If MAXSMP is enabled we just use the highest possible value and disable 955# interactive configuration. ) 956# 957 958config NR_CPUS_RANGE_BEGIN 959 int 960 default NR_CPUS_RANGE_END if MAXSMP 961 default 1 if !SMP 962 default 2 963 964config NR_CPUS_RANGE_END 965 int 966 depends on X86_32 967 default 64 if SMP && X86_BIGSMP 968 default 8 if SMP && !X86_BIGSMP 969 default 1 if !SMP 970 971config NR_CPUS_RANGE_END 972 int 973 depends on X86_64 974 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 975 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 976 default 1 if !SMP 977 978config NR_CPUS_DEFAULT 979 int 980 depends on X86_32 981 default 32 if X86_BIGSMP 982 default 8 if SMP 983 default 1 if !SMP 984 985config NR_CPUS_DEFAULT 986 int 987 depends on X86_64 988 default 8192 if MAXSMP 989 default 64 if SMP 990 default 1 if !SMP 991 992config NR_CPUS 993 int "Maximum number of CPUs" if SMP && !MAXSMP 994 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 995 default NR_CPUS_DEFAULT 996 ---help--- 997 This allows you to specify the maximum number of CPUs which this 998 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 999 supported value is 8192, otherwise the maximum value is 512. The 1000 minimum value which makes sense is 2. 1001 1002 This is purely to save memory: each supported CPU adds about 8KB 1003 to the kernel image. 1004 1005config SCHED_SMT 1006 bool "SMT (Hyperthreading) scheduler support" 1007 depends on SMP 1008 ---help--- 1009 SMT scheduler support improves the CPU scheduler's decision making 1010 when dealing with Intel Pentium 4 chips with HyperThreading at a 1011 cost of slightly increased overhead in some places. If unsure say 1012 N here. 1013 1014config SCHED_MC 1015 def_bool y 1016 prompt "Multi-core scheduler support" 1017 depends on SMP 1018 ---help--- 1019 Multi-core scheduler support improves the CPU scheduler's decision 1020 making when dealing with multi-core CPU chips at a cost of slightly 1021 increased overhead in some places. If unsure say N here. 1022 1023config SCHED_MC_PRIO 1024 bool "CPU core priorities scheduler support" 1025 depends on SCHED_MC && CPU_SUP_INTEL 1026 select X86_INTEL_PSTATE 1027 select CPU_FREQ 1028 default y 1029 ---help--- 1030 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1031 core ordering determined at manufacturing time, which allows 1032 certain cores to reach higher turbo frequencies (when running 1033 single threaded workloads) than others. 1034 1035 Enabling this kernel feature teaches the scheduler about 1036 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1037 scheduler's CPU selection logic accordingly, so that higher 1038 overall system performance can be achieved. 1039 1040 This feature will have no effect on CPUs without this feature. 1041 1042 If unsure say Y here. 1043 1044source "kernel/Kconfig.preempt" 1045 1046config UP_LATE_INIT 1047 def_bool y 1048 depends on !SMP && X86_LOCAL_APIC 1049 1050config X86_UP_APIC 1051 bool "Local APIC support on uniprocessors" if !PCI_MSI 1052 default PCI_MSI 1053 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1054 ---help--- 1055 A local APIC (Advanced Programmable Interrupt Controller) is an 1056 integrated interrupt controller in the CPU. If you have a single-CPU 1057 system which has a processor with a local APIC, you can say Y here to 1058 enable and use it. If you say Y here even though your machine doesn't 1059 have a local APIC, then the kernel will still run with no slowdown at 1060 all. The local APIC supports CPU-generated self-interrupts (timer, 1061 performance counters), and the NMI watchdog which detects hard 1062 lockups. 1063 1064config X86_UP_IOAPIC 1065 bool "IO-APIC support on uniprocessors" 1066 depends on X86_UP_APIC 1067 ---help--- 1068 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1069 SMP-capable replacement for PC-style interrupt controllers. Most 1070 SMP systems and many recent uniprocessor systems have one. 1071 1072 If you have a single-CPU system with an IO-APIC, you can say Y here 1073 to use it. If you say Y here even though your machine doesn't have 1074 an IO-APIC, then the kernel will still run with no slowdown at all. 1075 1076config X86_LOCAL_APIC 1077 def_bool y 1078 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1079 select IRQ_DOMAIN_HIERARCHY 1080 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1081 1082config X86_IO_APIC 1083 def_bool y 1084 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1085 1086config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1087 bool "Reroute for broken boot IRQs" 1088 depends on X86_IO_APIC 1089 ---help--- 1090 This option enables a workaround that fixes a source of 1091 spurious interrupts. This is recommended when threaded 1092 interrupt handling is used on systems where the generation of 1093 superfluous "boot interrupts" cannot be disabled. 1094 1095 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1096 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1097 kernel does during interrupt handling). On chipsets where this 1098 boot IRQ generation cannot be disabled, this workaround keeps 1099 the original IRQ line masked so that only the equivalent "boot 1100 IRQ" is delivered to the CPUs. The workaround also tells the 1101 kernel to set up the IRQ handler on the boot IRQ line. In this 1102 way only one interrupt is delivered to the kernel. Otherwise 1103 the spurious second interrupt may cause the kernel to bring 1104 down (vital) interrupt lines. 1105 1106 Only affects "broken" chipsets. Interrupt sharing may be 1107 increased on these systems. 1108 1109config X86_MCE 1110 bool "Machine Check / overheating reporting" 1111 select GENERIC_ALLOCATOR 1112 default y 1113 ---help--- 1114 Machine Check support allows the processor to notify the 1115 kernel if it detects a problem (e.g. overheating, data corruption). 1116 The action the kernel takes depends on the severity of the problem, 1117 ranging from warning messages to halting the machine. 1118 1119config X86_MCELOG_LEGACY 1120 bool "Support for deprecated /dev/mcelog character device" 1121 depends on X86_MCE 1122 ---help--- 1123 Enable support for /dev/mcelog which is needed by the old mcelog 1124 userspace logging daemon. Consider switching to the new generation 1125 rasdaemon solution. 1126 1127config X86_MCE_INTEL 1128 def_bool y 1129 prompt "Intel MCE features" 1130 depends on X86_MCE && X86_LOCAL_APIC 1131 ---help--- 1132 Additional support for intel specific MCE features such as 1133 the thermal monitor. 1134 1135config X86_MCE_AMD 1136 def_bool y 1137 prompt "AMD MCE features" 1138 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1139 ---help--- 1140 Additional support for AMD specific MCE features such as 1141 the DRAM Error Threshold. 1142 1143config X86_ANCIENT_MCE 1144 bool "Support for old Pentium 5 / WinChip machine checks" 1145 depends on X86_32 && X86_MCE 1146 ---help--- 1147 Include support for machine check handling on old Pentium 5 or WinChip 1148 systems. These typically need to be enabled explicitly on the command 1149 line. 1150 1151config X86_MCE_THRESHOLD 1152 depends on X86_MCE_AMD || X86_MCE_INTEL 1153 def_bool y 1154 1155config X86_MCE_INJECT 1156 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1157 tristate "Machine check injector support" 1158 ---help--- 1159 Provide support for injecting machine checks for testing purposes. 1160 If you don't know what a machine check is and you don't do kernel 1161 QA it is safe to say n. 1162 1163config X86_THERMAL_VECTOR 1164 def_bool y 1165 depends on X86_MCE_INTEL 1166 1167source "arch/x86/events/Kconfig" 1168 1169config X86_LEGACY_VM86 1170 bool "Legacy VM86 support" 1171 default n 1172 depends on X86_32 1173 ---help--- 1174 This option allows user programs to put the CPU into V8086 1175 mode, which is an 80286-era approximation of 16-bit real mode. 1176 1177 Some very old versions of X and/or vbetool require this option 1178 for user mode setting. Similarly, DOSEMU will use it if 1179 available to accelerate real mode DOS programs. However, any 1180 recent version of DOSEMU, X, or vbetool should be fully 1181 functional even without kernel VM86 support, as they will all 1182 fall back to software emulation. Nevertheless, if you are using 1183 a 16-bit DOS program where 16-bit performance matters, vm86 1184 mode might be faster than emulation and you might want to 1185 enable this option. 1186 1187 Note that any app that works on a 64-bit kernel is unlikely to 1188 need this option, as 64-bit kernels don't, and can't, support 1189 V8086 mode. This option is also unrelated to 16-bit protected 1190 mode and is not needed to run most 16-bit programs under Wine. 1191 1192 Enabling this option increases the complexity of the kernel 1193 and slows down exception handling a tiny bit. 1194 1195 If unsure, say N here. 1196 1197config VM86 1198 bool 1199 default X86_LEGACY_VM86 1200 1201config X86_16BIT 1202 bool "Enable support for 16-bit segments" if EXPERT 1203 default y 1204 depends on MODIFY_LDT_SYSCALL 1205 ---help--- 1206 This option is required by programs like Wine to run 16-bit 1207 protected mode legacy code on x86 processors. Disabling 1208 this option saves about 300 bytes on i386, or around 6K text 1209 plus 16K runtime memory on x86-64, 1210 1211config X86_ESPFIX32 1212 def_bool y 1213 depends on X86_16BIT && X86_32 1214 1215config X86_ESPFIX64 1216 def_bool y 1217 depends on X86_16BIT && X86_64 1218 1219config X86_VSYSCALL_EMULATION 1220 bool "Enable vsyscall emulation" if EXPERT 1221 default y 1222 depends on X86_64 1223 ---help--- 1224 This enables emulation of the legacy vsyscall page. Disabling 1225 it is roughly equivalent to booting with vsyscall=none, except 1226 that it will also disable the helpful warning if a program 1227 tries to use a vsyscall. With this option set to N, offending 1228 programs will just segfault, citing addresses of the form 1229 0xffffffffff600?00. 1230 1231 This option is required by many programs built before 2013, and 1232 care should be used even with newer programs if set to N. 1233 1234 Disabling this option saves about 7K of kernel size and 1235 possibly 4K of additional runtime pagetable memory. 1236 1237config TOSHIBA 1238 tristate "Toshiba Laptop support" 1239 depends on X86_32 1240 ---help--- 1241 This adds a driver to safely access the System Management Mode of 1242 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1243 not work on models with a Phoenix BIOS. The System Management Mode 1244 is used to set the BIOS and power saving options on Toshiba portables. 1245 1246 For information on utilities to make use of this driver see the 1247 Toshiba Linux utilities web site at: 1248 <http://www.buzzard.org.uk/toshiba/>. 1249 1250 Say Y if you intend to run this kernel on a Toshiba portable. 1251 Say N otherwise. 1252 1253config I8K 1254 tristate "Dell i8k legacy laptop support" 1255 select HWMON 1256 select SENSORS_DELL_SMM 1257 ---help--- 1258 This option enables legacy /proc/i8k userspace interface in hwmon 1259 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1260 temperature and allows controlling fan speeds of Dell laptops via 1261 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1262 it reports also power and hotkey status. For fan speed control is 1263 needed userspace package i8kutils. 1264 1265 Say Y if you intend to run this kernel on old Dell laptops or want to 1266 use userspace package i8kutils. 1267 Say N otherwise. 1268 1269config X86_REBOOTFIXUPS 1270 bool "Enable X86 board specific fixups for reboot" 1271 depends on X86_32 1272 ---help--- 1273 This enables chipset and/or board specific fixups to be done 1274 in order to get reboot to work correctly. This is only needed on 1275 some combinations of hardware and BIOS. The symptom, for which 1276 this config is intended, is when reboot ends with a stalled/hung 1277 system. 1278 1279 Currently, the only fixup is for the Geode machines using 1280 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1281 1282 Say Y if you want to enable the fixup. Currently, it's safe to 1283 enable this option even if you don't need it. 1284 Say N otherwise. 1285 1286config MICROCODE 1287 bool "CPU microcode loading support" 1288 default y 1289 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1290 select FW_LOADER 1291 ---help--- 1292 If you say Y here, you will be able to update the microcode on 1293 Intel and AMD processors. The Intel support is for the IA32 family, 1294 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1295 AMD support is for families 0x10 and later. You will obviously need 1296 the actual microcode binary data itself which is not shipped with 1297 the Linux kernel. 1298 1299 The preferred method to load microcode from a detached initrd is described 1300 in Documentation/x86/microcode.txt. For that you need to enable 1301 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1302 initrd for microcode blobs. 1303 1304 In addition, you can build the microcode into the kernel. For that you 1305 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1306 config option. 1307 1308config MICROCODE_INTEL 1309 bool "Intel microcode loading support" 1310 depends on MICROCODE 1311 default MICROCODE 1312 select FW_LOADER 1313 ---help--- 1314 This options enables microcode patch loading support for Intel 1315 processors. 1316 1317 For the current Intel microcode data package go to 1318 <https://downloadcenter.intel.com> and search for 1319 'Linux Processor Microcode Data File'. 1320 1321config MICROCODE_AMD 1322 bool "AMD microcode loading support" 1323 depends on MICROCODE 1324 select FW_LOADER 1325 ---help--- 1326 If you select this option, microcode patch loading support for AMD 1327 processors will be enabled. 1328 1329config MICROCODE_OLD_INTERFACE 1330 def_bool y 1331 depends on MICROCODE 1332 1333config X86_MSR 1334 tristate "/dev/cpu/*/msr - Model-specific register support" 1335 ---help--- 1336 This device gives privileged processes access to the x86 1337 Model-Specific Registers (MSRs). It is a character device with 1338 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1339 MSR accesses are directed to a specific CPU on multi-processor 1340 systems. 1341 1342config X86_CPUID 1343 tristate "/dev/cpu/*/cpuid - CPU information support" 1344 ---help--- 1345 This device gives processes access to the x86 CPUID instruction to 1346 be executed on a specific processor. It is a character device 1347 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1348 /dev/cpu/31/cpuid. 1349 1350choice 1351 prompt "High Memory Support" 1352 default HIGHMEM4G 1353 depends on X86_32 1354 1355config NOHIGHMEM 1356 bool "off" 1357 ---help--- 1358 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1359 However, the address space of 32-bit x86 processors is only 4 1360 Gigabytes large. That means that, if you have a large amount of 1361 physical memory, not all of it can be "permanently mapped" by the 1362 kernel. The physical memory that's not permanently mapped is called 1363 "high memory". 1364 1365 If you are compiling a kernel which will never run on a machine with 1366 more than 1 Gigabyte total physical RAM, answer "off" here (default 1367 choice and suitable for most users). This will result in a "3GB/1GB" 1368 split: 3GB are mapped so that each process sees a 3GB virtual memory 1369 space and the remaining part of the 4GB virtual memory space is used 1370 by the kernel to permanently map as much physical memory as 1371 possible. 1372 1373 If the machine has between 1 and 4 Gigabytes physical RAM, then 1374 answer "4GB" here. 1375 1376 If more than 4 Gigabytes is used then answer "64GB" here. This 1377 selection turns Intel PAE (Physical Address Extension) mode on. 1378 PAE implements 3-level paging on IA32 processors. PAE is fully 1379 supported by Linux, PAE mode is implemented on all recent Intel 1380 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1381 then the kernel will not boot on CPUs that don't support PAE! 1382 1383 The actual amount of total physical memory will either be 1384 auto detected or can be forced by using a kernel command line option 1385 such as "mem=256M". (Try "man bootparam" or see the documentation of 1386 your boot loader (lilo or loadlin) about how to pass options to the 1387 kernel at boot time.) 1388 1389 If unsure, say "off". 1390 1391config HIGHMEM4G 1392 bool "4GB" 1393 ---help--- 1394 Select this if you have a 32-bit processor and between 1 and 4 1395 gigabytes of physical RAM. 1396 1397config HIGHMEM64G 1398 bool "64GB" 1399 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1400 select X86_PAE 1401 ---help--- 1402 Select this if you have a 32-bit processor and more than 4 1403 gigabytes of physical RAM. 1404 1405endchoice 1406 1407choice 1408 prompt "Memory split" if EXPERT 1409 default VMSPLIT_3G 1410 depends on X86_32 1411 ---help--- 1412 Select the desired split between kernel and user memory. 1413 1414 If the address range available to the kernel is less than the 1415 physical memory installed, the remaining memory will be available 1416 as "high memory". Accessing high memory is a little more costly 1417 than low memory, as it needs to be mapped into the kernel first. 1418 Note that increasing the kernel address space limits the range 1419 available to user programs, making the address space there 1420 tighter. Selecting anything other than the default 3G/1G split 1421 will also likely make your kernel incompatible with binary-only 1422 kernel modules. 1423 1424 If you are not absolutely sure what you are doing, leave this 1425 option alone! 1426 1427 config VMSPLIT_3G 1428 bool "3G/1G user/kernel split" 1429 config VMSPLIT_3G_OPT 1430 depends on !X86_PAE 1431 bool "3G/1G user/kernel split (for full 1G low memory)" 1432 config VMSPLIT_2G 1433 bool "2G/2G user/kernel split" 1434 config VMSPLIT_2G_OPT 1435 depends on !X86_PAE 1436 bool "2G/2G user/kernel split (for full 2G low memory)" 1437 config VMSPLIT_1G 1438 bool "1G/3G user/kernel split" 1439endchoice 1440 1441config PAGE_OFFSET 1442 hex 1443 default 0xB0000000 if VMSPLIT_3G_OPT 1444 default 0x80000000 if VMSPLIT_2G 1445 default 0x78000000 if VMSPLIT_2G_OPT 1446 default 0x40000000 if VMSPLIT_1G 1447 default 0xC0000000 1448 depends on X86_32 1449 1450config HIGHMEM 1451 def_bool y 1452 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1453 1454config X86_PAE 1455 bool "PAE (Physical Address Extension) Support" 1456 depends on X86_32 && !HIGHMEM4G 1457 select SWIOTLB 1458 ---help--- 1459 PAE is required for NX support, and furthermore enables 1460 larger swapspace support for non-overcommit purposes. It 1461 has the cost of more pagetable lookup overhead, and also 1462 consumes more pagetable space per process. 1463 1464config X86_5LEVEL 1465 bool "Enable 5-level page tables support" 1466 select DYNAMIC_MEMORY_LAYOUT 1467 select SPARSEMEM_VMEMMAP 1468 depends on X86_64 1469 ---help--- 1470 5-level paging enables access to larger address space: 1471 upto 128 PiB of virtual address space and 4 PiB of 1472 physical address space. 1473 1474 It will be supported by future Intel CPUs. 1475 1476 A kernel with the option enabled can be booted on machines that 1477 support 4- or 5-level paging. 1478 1479 See Documentation/x86/x86_64/5level-paging.txt for more 1480 information. 1481 1482 Say N if unsure. 1483 1484config ARCH_PHYS_ADDR_T_64BIT 1485 def_bool y 1486 depends on X86_64 || X86_PAE 1487 1488config ARCH_DMA_ADDR_T_64BIT 1489 def_bool y 1490 depends on X86_64 || HIGHMEM64G 1491 1492config X86_DIRECT_GBPAGES 1493 def_bool y 1494 depends on X86_64 && !DEBUG_PAGEALLOC 1495 ---help--- 1496 Certain kernel features effectively disable kernel 1497 linear 1 GB mappings (even if the CPU otherwise 1498 supports them), so don't confuse the user by printing 1499 that we have them enabled. 1500 1501config ARCH_HAS_MEM_ENCRYPT 1502 def_bool y 1503 1504config AMD_MEM_ENCRYPT 1505 bool "AMD Secure Memory Encryption (SME) support" 1506 depends on X86_64 && CPU_SUP_AMD 1507 ---help--- 1508 Say yes to enable support for the encryption of system memory. 1509 This requires an AMD processor that supports Secure Memory 1510 Encryption (SME). 1511 1512config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1513 bool "Activate AMD Secure Memory Encryption (SME) by default" 1514 default y 1515 depends on AMD_MEM_ENCRYPT 1516 ---help--- 1517 Say yes to have system memory encrypted by default if running on 1518 an AMD processor that supports Secure Memory Encryption (SME). 1519 1520 If set to Y, then the encryption of system memory can be 1521 deactivated with the mem_encrypt=off command line option. 1522 1523 If set to N, then the encryption of system memory can be 1524 activated with the mem_encrypt=on command line option. 1525 1526config ARCH_USE_MEMREMAP_PROT 1527 def_bool y 1528 depends on AMD_MEM_ENCRYPT 1529 1530# Common NUMA Features 1531config NUMA 1532 bool "Numa Memory Allocation and Scheduler Support" 1533 depends on SMP 1534 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1535 default y if X86_BIGSMP 1536 ---help--- 1537 Enable NUMA (Non Uniform Memory Access) support. 1538 1539 The kernel will try to allocate memory used by a CPU on the 1540 local memory controller of the CPU and add some more 1541 NUMA awareness to the kernel. 1542 1543 For 64-bit this is recommended if the system is Intel Core i7 1544 (or later), AMD Opteron, or EM64T NUMA. 1545 1546 For 32-bit this is only needed if you boot a 32-bit 1547 kernel on a 64-bit NUMA platform. 1548 1549 Otherwise, you should say N. 1550 1551config AMD_NUMA 1552 def_bool y 1553 prompt "Old style AMD Opteron NUMA detection" 1554 depends on X86_64 && NUMA && PCI 1555 ---help--- 1556 Enable AMD NUMA node topology detection. You should say Y here if 1557 you have a multi processor AMD system. This uses an old method to 1558 read the NUMA configuration directly from the builtin Northbridge 1559 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1560 which also takes priority if both are compiled in. 1561 1562config X86_64_ACPI_NUMA 1563 def_bool y 1564 prompt "ACPI NUMA detection" 1565 depends on X86_64 && NUMA && ACPI && PCI 1566 select ACPI_NUMA 1567 ---help--- 1568 Enable ACPI SRAT based node topology detection. 1569 1570# Some NUMA nodes have memory ranges that span 1571# other nodes. Even though a pfn is valid and 1572# between a node's start and end pfns, it may not 1573# reside on that node. See memmap_init_zone() 1574# for details. 1575config NODES_SPAN_OTHER_NODES 1576 def_bool y 1577 depends on X86_64_ACPI_NUMA 1578 1579config NUMA_EMU 1580 bool "NUMA emulation" 1581 depends on NUMA 1582 ---help--- 1583 Enable NUMA emulation. A flat machine will be split 1584 into virtual nodes when booted with "numa=fake=N", where N is the 1585 number of nodes. This is only useful for debugging. 1586 1587config NODES_SHIFT 1588 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1589 range 1 10 1590 default "10" if MAXSMP 1591 default "6" if X86_64 1592 default "3" 1593 depends on NEED_MULTIPLE_NODES 1594 ---help--- 1595 Specify the maximum number of NUMA Nodes available on the target 1596 system. Increases memory reserved to accommodate various tables. 1597 1598config ARCH_HAVE_MEMORY_PRESENT 1599 def_bool y 1600 depends on X86_32 && DISCONTIGMEM 1601 1602config ARCH_FLATMEM_ENABLE 1603 def_bool y 1604 depends on X86_32 && !NUMA 1605 1606config ARCH_DISCONTIGMEM_ENABLE 1607 def_bool y 1608 depends on NUMA && X86_32 1609 1610config ARCH_DISCONTIGMEM_DEFAULT 1611 def_bool y 1612 depends on NUMA && X86_32 1613 1614config ARCH_SPARSEMEM_ENABLE 1615 def_bool y 1616 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1617 select SPARSEMEM_STATIC if X86_32 1618 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1619 1620config ARCH_SPARSEMEM_DEFAULT 1621 def_bool y 1622 depends on X86_64 1623 1624config ARCH_SELECT_MEMORY_MODEL 1625 def_bool y 1626 depends on ARCH_SPARSEMEM_ENABLE 1627 1628config ARCH_MEMORY_PROBE 1629 bool "Enable sysfs memory/probe interface" 1630 depends on X86_64 && MEMORY_HOTPLUG 1631 help 1632 This option enables a sysfs memory/probe interface for testing. 1633 See Documentation/memory-hotplug.txt for more information. 1634 If you are unsure how to answer this question, answer N. 1635 1636config ARCH_PROC_KCORE_TEXT 1637 def_bool y 1638 depends on X86_64 && PROC_KCORE 1639 1640config ILLEGAL_POINTER_VALUE 1641 hex 1642 default 0 if X86_32 1643 default 0xdead000000000000 if X86_64 1644 1645source "mm/Kconfig" 1646 1647config X86_PMEM_LEGACY_DEVICE 1648 bool 1649 1650config X86_PMEM_LEGACY 1651 tristate "Support non-standard NVDIMMs and ADR protected memory" 1652 depends on PHYS_ADDR_T_64BIT 1653 depends on BLK_DEV 1654 select X86_PMEM_LEGACY_DEVICE 1655 select LIBNVDIMM 1656 help 1657 Treat memory marked using the non-standard e820 type of 12 as used 1658 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1659 The kernel will offer these regions to the 'pmem' driver so 1660 they can be used for persistent storage. 1661 1662 Say Y if unsure. 1663 1664config HIGHPTE 1665 bool "Allocate 3rd-level pagetables from highmem" 1666 depends on HIGHMEM 1667 ---help--- 1668 The VM uses one page table entry for each page of physical memory. 1669 For systems with a lot of RAM, this can be wasteful of precious 1670 low memory. Setting this option will put user-space page table 1671 entries in high memory. 1672 1673config X86_CHECK_BIOS_CORRUPTION 1674 bool "Check for low memory corruption" 1675 ---help--- 1676 Periodically check for memory corruption in low memory, which 1677 is suspected to be caused by BIOS. Even when enabled in the 1678 configuration, it is disabled at runtime. Enable it by 1679 setting "memory_corruption_check=1" on the kernel command 1680 line. By default it scans the low 64k of memory every 60 1681 seconds; see the memory_corruption_check_size and 1682 memory_corruption_check_period parameters in 1683 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1684 1685 When enabled with the default parameters, this option has 1686 almost no overhead, as it reserves a relatively small amount 1687 of memory and scans it infrequently. It both detects corruption 1688 and prevents it from affecting the running system. 1689 1690 It is, however, intended as a diagnostic tool; if repeatable 1691 BIOS-originated corruption always affects the same memory, 1692 you can use memmap= to prevent the kernel from using that 1693 memory. 1694 1695config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1696 bool "Set the default setting of memory_corruption_check" 1697 depends on X86_CHECK_BIOS_CORRUPTION 1698 default y 1699 ---help--- 1700 Set whether the default state of memory_corruption_check is 1701 on or off. 1702 1703config X86_RESERVE_LOW 1704 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1705 default 64 1706 range 4 640 1707 ---help--- 1708 Specify the amount of low memory to reserve for the BIOS. 1709 1710 The first page contains BIOS data structures that the kernel 1711 must not use, so that page must always be reserved. 1712 1713 By default we reserve the first 64K of physical RAM, as a 1714 number of BIOSes are known to corrupt that memory range 1715 during events such as suspend/resume or monitor cable 1716 insertion, so it must not be used by the kernel. 1717 1718 You can set this to 4 if you are absolutely sure that you 1719 trust the BIOS to get all its memory reservations and usages 1720 right. If you know your BIOS have problems beyond the 1721 default 64K area, you can set this to 640 to avoid using the 1722 entire low memory range. 1723 1724 If you have doubts about the BIOS (e.g. suspend/resume does 1725 not work or there's kernel crashes after certain hardware 1726 hotplug events) then you might want to enable 1727 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1728 typical corruption patterns. 1729 1730 Leave this to the default value of 64 if you are unsure. 1731 1732config MATH_EMULATION 1733 bool 1734 depends on MODIFY_LDT_SYSCALL 1735 prompt "Math emulation" if X86_32 1736 ---help--- 1737 Linux can emulate a math coprocessor (used for floating point 1738 operations) if you don't have one. 486DX and Pentium processors have 1739 a math coprocessor built in, 486SX and 386 do not, unless you added 1740 a 487DX or 387, respectively. (The messages during boot time can 1741 give you some hints here ["man dmesg"].) Everyone needs either a 1742 coprocessor or this emulation. 1743 1744 If you don't have a math coprocessor, you need to say Y here; if you 1745 say Y here even though you have a coprocessor, the coprocessor will 1746 be used nevertheless. (This behavior can be changed with the kernel 1747 command line option "no387", which comes handy if your coprocessor 1748 is broken. Try "man bootparam" or see the documentation of your boot 1749 loader (lilo or loadlin) about how to pass options to the kernel at 1750 boot time.) This means that it is a good idea to say Y here if you 1751 intend to use this kernel on different machines. 1752 1753 More information about the internals of the Linux math coprocessor 1754 emulation can be found in <file:arch/x86/math-emu/README>. 1755 1756 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1757 kernel, it won't hurt. 1758 1759config MTRR 1760 def_bool y 1761 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1762 ---help--- 1763 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1764 the Memory Type Range Registers (MTRRs) may be used to control 1765 processor access to memory ranges. This is most useful if you have 1766 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1767 allows bus write transfers to be combined into a larger transfer 1768 before bursting over the PCI/AGP bus. This can increase performance 1769 of image write operations 2.5 times or more. Saying Y here creates a 1770 /proc/mtrr file which may be used to manipulate your processor's 1771 MTRRs. Typically the X server should use this. 1772 1773 This code has a reasonably generic interface so that similar 1774 control registers on other processors can be easily supported 1775 as well: 1776 1777 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1778 Registers (ARRs) which provide a similar functionality to MTRRs. For 1779 these, the ARRs are used to emulate the MTRRs. 1780 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1781 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1782 write-combining. All of these processors are supported by this code 1783 and it makes sense to say Y here if you have one of them. 1784 1785 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1786 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1787 can lead to all sorts of problems, so it's good to say Y here. 1788 1789 You can safely say Y even if your machine doesn't have MTRRs, you'll 1790 just add about 9 KB to your kernel. 1791 1792 See <file:Documentation/x86/mtrr.txt> for more information. 1793 1794config MTRR_SANITIZER 1795 def_bool y 1796 prompt "MTRR cleanup support" 1797 depends on MTRR 1798 ---help--- 1799 Convert MTRR layout from continuous to discrete, so X drivers can 1800 add writeback entries. 1801 1802 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1803 The largest mtrr entry size for a continuous block can be set with 1804 mtrr_chunk_size. 1805 1806 If unsure, say Y. 1807 1808config MTRR_SANITIZER_ENABLE_DEFAULT 1809 int "MTRR cleanup enable value (0-1)" 1810 range 0 1 1811 default "0" 1812 depends on MTRR_SANITIZER 1813 ---help--- 1814 Enable mtrr cleanup default value 1815 1816config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1817 int "MTRR cleanup spare reg num (0-7)" 1818 range 0 7 1819 default "1" 1820 depends on MTRR_SANITIZER 1821 ---help--- 1822 mtrr cleanup spare entries default, it can be changed via 1823 mtrr_spare_reg_nr=N on the kernel command line. 1824 1825config X86_PAT 1826 def_bool y 1827 prompt "x86 PAT support" if EXPERT 1828 depends on MTRR 1829 ---help--- 1830 Use PAT attributes to setup page level cache control. 1831 1832 PATs are the modern equivalents of MTRRs and are much more 1833 flexible than MTRRs. 1834 1835 Say N here if you see bootup problems (boot crash, boot hang, 1836 spontaneous reboots) or a non-working video driver. 1837 1838 If unsure, say Y. 1839 1840config ARCH_USES_PG_UNCACHED 1841 def_bool y 1842 depends on X86_PAT 1843 1844config ARCH_RANDOM 1845 def_bool y 1846 prompt "x86 architectural random number generator" if EXPERT 1847 ---help--- 1848 Enable the x86 architectural RDRAND instruction 1849 (Intel Bull Mountain technology) to generate random numbers. 1850 If supported, this is a high bandwidth, cryptographically 1851 secure hardware random number generator. 1852 1853config X86_SMAP 1854 def_bool y 1855 prompt "Supervisor Mode Access Prevention" if EXPERT 1856 ---help--- 1857 Supervisor Mode Access Prevention (SMAP) is a security 1858 feature in newer Intel processors. There is a small 1859 performance cost if this enabled and turned on; there is 1860 also a small increase in the kernel size if this is enabled. 1861 1862 If unsure, say Y. 1863 1864config X86_INTEL_UMIP 1865 def_bool y 1866 depends on CPU_SUP_INTEL 1867 prompt "Intel User Mode Instruction Prevention" if EXPERT 1868 ---help--- 1869 The User Mode Instruction Prevention (UMIP) is a security 1870 feature in newer Intel processors. If enabled, a general 1871 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1872 or STR instructions are executed in user mode. These instructions 1873 unnecessarily expose information about the hardware state. 1874 1875 The vast majority of applications do not use these instructions. 1876 For the very few that do, software emulation is provided in 1877 specific cases in protected and virtual-8086 modes. Emulated 1878 results are dummy. 1879 1880config X86_INTEL_MPX 1881 prompt "Intel MPX (Memory Protection Extensions)" 1882 def_bool n 1883 # Note: only available in 64-bit mode due to VMA flags shortage 1884 depends on CPU_SUP_INTEL && X86_64 1885 select ARCH_USES_HIGH_VMA_FLAGS 1886 ---help--- 1887 MPX provides hardware features that can be used in 1888 conjunction with compiler-instrumented code to check 1889 memory references. It is designed to detect buffer 1890 overflow or underflow bugs. 1891 1892 This option enables running applications which are 1893 instrumented or otherwise use MPX. It does not use MPX 1894 itself inside the kernel or to protect the kernel 1895 against bad memory references. 1896 1897 Enabling this option will make the kernel larger: 1898 ~8k of kernel text and 36 bytes of data on a 64-bit 1899 defconfig. It adds a long to the 'mm_struct' which 1900 will increase the kernel memory overhead of each 1901 process and adds some branches to paths used during 1902 exec() and munmap(). 1903 1904 For details, see Documentation/x86/intel_mpx.txt 1905 1906 If unsure, say N. 1907 1908config X86_INTEL_MEMORY_PROTECTION_KEYS 1909 prompt "Intel Memory Protection Keys" 1910 def_bool y 1911 # Note: only available in 64-bit mode 1912 depends on CPU_SUP_INTEL && X86_64 1913 select ARCH_USES_HIGH_VMA_FLAGS 1914 select ARCH_HAS_PKEYS 1915 ---help--- 1916 Memory Protection Keys provides a mechanism for enforcing 1917 page-based protections, but without requiring modification of the 1918 page tables when an application changes protection domains. 1919 1920 For details, see Documentation/x86/protection-keys.txt 1921 1922 If unsure, say y. 1923 1924config EFI 1925 bool "EFI runtime service support" 1926 depends on ACPI 1927 select UCS2_STRING 1928 select EFI_RUNTIME_WRAPPERS 1929 ---help--- 1930 This enables the kernel to use EFI runtime services that are 1931 available (such as the EFI variable services). 1932 1933 This option is only useful on systems that have EFI firmware. 1934 In addition, you should use the latest ELILO loader available 1935 at <http://elilo.sourceforge.net> in order to take advantage 1936 of EFI runtime services. However, even with this option, the 1937 resultant kernel should continue to boot on existing non-EFI 1938 platforms. 1939 1940config EFI_STUB 1941 bool "EFI stub support" 1942 depends on EFI && !X86_USE_3DNOW 1943 select RELOCATABLE 1944 ---help--- 1945 This kernel feature allows a bzImage to be loaded directly 1946 by EFI firmware without the use of a bootloader. 1947 1948 See Documentation/efi-stub.txt for more information. 1949 1950config EFI_MIXED 1951 bool "EFI mixed-mode support" 1952 depends on EFI_STUB && X86_64 1953 ---help--- 1954 Enabling this feature allows a 64-bit kernel to be booted 1955 on a 32-bit firmware, provided that your CPU supports 64-bit 1956 mode. 1957 1958 Note that it is not possible to boot a mixed-mode enabled 1959 kernel via the EFI boot stub - a bootloader that supports 1960 the EFI handover protocol must be used. 1961 1962 If unsure, say N. 1963 1964config SECCOMP 1965 def_bool y 1966 prompt "Enable seccomp to safely compute untrusted bytecode" 1967 ---help--- 1968 This kernel feature is useful for number crunching applications 1969 that may need to compute untrusted bytecode during their 1970 execution. By using pipes or other transports made available to 1971 the process as file descriptors supporting the read/write 1972 syscalls, it's possible to isolate those applications in 1973 their own address space using seccomp. Once seccomp is 1974 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1975 and the task is only allowed to execute a few safe syscalls 1976 defined by each seccomp mode. 1977 1978 If unsure, say Y. Only embedded should say N here. 1979 1980source kernel/Kconfig.hz 1981 1982config KEXEC 1983 bool "kexec system call" 1984 select KEXEC_CORE 1985 ---help--- 1986 kexec is a system call that implements the ability to shutdown your 1987 current kernel, and to start another kernel. It is like a reboot 1988 but it is independent of the system firmware. And like a reboot 1989 you can start any kernel with it, not just Linux. 1990 1991 The name comes from the similarity to the exec system call. 1992 1993 It is an ongoing process to be certain the hardware in a machine 1994 is properly shutdown, so do not be surprised if this code does not 1995 initially work for you. As of this writing the exact hardware 1996 interface is strongly in flux, so no good recommendation can be 1997 made. 1998 1999config KEXEC_FILE 2000 bool "kexec file based system call" 2001 select KEXEC_CORE 2002 select BUILD_BIN2C 2003 depends on X86_64 2004 depends on CRYPTO=y 2005 depends on CRYPTO_SHA256=y 2006 ---help--- 2007 This is new version of kexec system call. This system call is 2008 file based and takes file descriptors as system call argument 2009 for kernel and initramfs as opposed to list of segments as 2010 accepted by previous system call. 2011 2012config ARCH_HAS_KEXEC_PURGATORY 2013 def_bool KEXEC_FILE 2014 2015config KEXEC_VERIFY_SIG 2016 bool "Verify kernel signature during kexec_file_load() syscall" 2017 depends on KEXEC_FILE 2018 ---help--- 2019 This option makes kernel signature verification mandatory for 2020 the kexec_file_load() syscall. 2021 2022 In addition to that option, you need to enable signature 2023 verification for the corresponding kernel image type being 2024 loaded in order for this to work. 2025 2026config KEXEC_BZIMAGE_VERIFY_SIG 2027 bool "Enable bzImage signature verification support" 2028 depends on KEXEC_VERIFY_SIG 2029 depends on SIGNED_PE_FILE_VERIFICATION 2030 select SYSTEM_TRUSTED_KEYRING 2031 ---help--- 2032 Enable bzImage signature verification support. 2033 2034config CRASH_DUMP 2035 bool "kernel crash dumps" 2036 depends on X86_64 || (X86_32 && HIGHMEM) 2037 ---help--- 2038 Generate crash dump after being started by kexec. 2039 This should be normally only set in special crash dump kernels 2040 which are loaded in the main kernel with kexec-tools into 2041 a specially reserved region and then later executed after 2042 a crash by kdump/kexec. The crash dump kernel must be compiled 2043 to a memory address not used by the main kernel or BIOS using 2044 PHYSICAL_START, or it must be built as a relocatable image 2045 (CONFIG_RELOCATABLE=y). 2046 For more details see Documentation/kdump/kdump.txt 2047 2048config KEXEC_JUMP 2049 bool "kexec jump" 2050 depends on KEXEC && HIBERNATION 2051 ---help--- 2052 Jump between original kernel and kexeced kernel and invoke 2053 code in physical address mode via KEXEC 2054 2055config PHYSICAL_START 2056 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2057 default "0x1000000" 2058 ---help--- 2059 This gives the physical address where the kernel is loaded. 2060 2061 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2062 bzImage will decompress itself to above physical address and 2063 run from there. Otherwise, bzImage will run from the address where 2064 it has been loaded by the boot loader and will ignore above physical 2065 address. 2066 2067 In normal kdump cases one does not have to set/change this option 2068 as now bzImage can be compiled as a completely relocatable image 2069 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2070 address. This option is mainly useful for the folks who don't want 2071 to use a bzImage for capturing the crash dump and want to use a 2072 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2073 to be specifically compiled to run from a specific memory area 2074 (normally a reserved region) and this option comes handy. 2075 2076 So if you are using bzImage for capturing the crash dump, 2077 leave the value here unchanged to 0x1000000 and set 2078 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2079 for capturing the crash dump change this value to start of 2080 the reserved region. In other words, it can be set based on 2081 the "X" value as specified in the "crashkernel=YM@XM" 2082 command line boot parameter passed to the panic-ed 2083 kernel. Please take a look at Documentation/kdump/kdump.txt 2084 for more details about crash dumps. 2085 2086 Usage of bzImage for capturing the crash dump is recommended as 2087 one does not have to build two kernels. Same kernel can be used 2088 as production kernel and capture kernel. Above option should have 2089 gone away after relocatable bzImage support is introduced. But it 2090 is present because there are users out there who continue to use 2091 vmlinux for dump capture. This option should go away down the 2092 line. 2093 2094 Don't change this unless you know what you are doing. 2095 2096config RELOCATABLE 2097 bool "Build a relocatable kernel" 2098 default y 2099 ---help--- 2100 This builds a kernel image that retains relocation information 2101 so it can be loaded someplace besides the default 1MB. 2102 The relocations tend to make the kernel binary about 10% larger, 2103 but are discarded at runtime. 2104 2105 One use is for the kexec on panic case where the recovery kernel 2106 must live at a different physical address than the primary 2107 kernel. 2108 2109 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2110 it has been loaded at and the compile time physical address 2111 (CONFIG_PHYSICAL_START) is used as the minimum location. 2112 2113config RANDOMIZE_BASE 2114 bool "Randomize the address of the kernel image (KASLR)" 2115 depends on RELOCATABLE 2116 default y 2117 ---help--- 2118 In support of Kernel Address Space Layout Randomization (KASLR), 2119 this randomizes the physical address at which the kernel image 2120 is decompressed and the virtual address where the kernel 2121 image is mapped, as a security feature that deters exploit 2122 attempts relying on knowledge of the location of kernel 2123 code internals. 2124 2125 On 64-bit, the kernel physical and virtual addresses are 2126 randomized separately. The physical address will be anywhere 2127 between 16MB and the top of physical memory (up to 64TB). The 2128 virtual address will be randomized from 16MB up to 1GB (9 bits 2129 of entropy). Note that this also reduces the memory space 2130 available to kernel modules from 1.5GB to 1GB. 2131 2132 On 32-bit, the kernel physical and virtual addresses are 2133 randomized together. They will be randomized from 16MB up to 2134 512MB (8 bits of entropy). 2135 2136 Entropy is generated using the RDRAND instruction if it is 2137 supported. If RDTSC is supported, its value is mixed into 2138 the entropy pool as well. If neither RDRAND nor RDTSC are 2139 supported, then entropy is read from the i8254 timer. The 2140 usable entropy is limited by the kernel being built using 2141 2GB addressing, and that PHYSICAL_ALIGN must be at a 2142 minimum of 2MB. As a result, only 10 bits of entropy are 2143 theoretically possible, but the implementations are further 2144 limited due to memory layouts. 2145 2146 If unsure, say Y. 2147 2148# Relocation on x86 needs some additional build support 2149config X86_NEED_RELOCS 2150 def_bool y 2151 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2152 2153config PHYSICAL_ALIGN 2154 hex "Alignment value to which kernel should be aligned" 2155 default "0x200000" 2156 range 0x2000 0x1000000 if X86_32 2157 range 0x200000 0x1000000 if X86_64 2158 ---help--- 2159 This value puts the alignment restrictions on physical address 2160 where kernel is loaded and run from. Kernel is compiled for an 2161 address which meets above alignment restriction. 2162 2163 If bootloader loads the kernel at a non-aligned address and 2164 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2165 address aligned to above value and run from there. 2166 2167 If bootloader loads the kernel at a non-aligned address and 2168 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2169 load address and decompress itself to the address it has been 2170 compiled for and run from there. The address for which kernel is 2171 compiled already meets above alignment restrictions. Hence the 2172 end result is that kernel runs from a physical address meeting 2173 above alignment restrictions. 2174 2175 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2176 this value must be a multiple of 0x200000. 2177 2178 Don't change this unless you know what you are doing. 2179 2180config DYNAMIC_MEMORY_LAYOUT 2181 bool 2182 ---help--- 2183 This option makes base addresses of vmalloc and vmemmap as well as 2184 __PAGE_OFFSET movable during boot. 2185 2186config RANDOMIZE_MEMORY 2187 bool "Randomize the kernel memory sections" 2188 depends on X86_64 2189 depends on RANDOMIZE_BASE 2190 select DYNAMIC_MEMORY_LAYOUT 2191 default RANDOMIZE_BASE 2192 ---help--- 2193 Randomizes the base virtual address of kernel memory sections 2194 (physical memory mapping, vmalloc & vmemmap). This security feature 2195 makes exploits relying on predictable memory locations less reliable. 2196 2197 The order of allocations remains unchanged. Entropy is generated in 2198 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2199 configuration have in average 30,000 different possible virtual 2200 addresses for each memory section. 2201 2202 If unsure, say Y. 2203 2204config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2205 hex "Physical memory mapping padding" if EXPERT 2206 depends on RANDOMIZE_MEMORY 2207 default "0xa" if MEMORY_HOTPLUG 2208 default "0x0" 2209 range 0x1 0x40 if MEMORY_HOTPLUG 2210 range 0x0 0x40 2211 ---help--- 2212 Define the padding in terabytes added to the existing physical 2213 memory size during kernel memory randomization. It is useful 2214 for memory hotplug support but reduces the entropy available for 2215 address randomization. 2216 2217 If unsure, leave at the default value. 2218 2219config HOTPLUG_CPU 2220 bool "Support for hot-pluggable CPUs" 2221 depends on SMP 2222 ---help--- 2223 Say Y here to allow turning CPUs off and on. CPUs can be 2224 controlled through /sys/devices/system/cpu. 2225 ( Note: power management support will enable this option 2226 automatically on SMP systems. ) 2227 Say N if you want to disable CPU hotplug. 2228 2229config BOOTPARAM_HOTPLUG_CPU0 2230 bool "Set default setting of cpu0_hotpluggable" 2231 default n 2232 depends on HOTPLUG_CPU 2233 ---help--- 2234 Set whether default state of cpu0_hotpluggable is on or off. 2235 2236 Say Y here to enable CPU0 hotplug by default. If this switch 2237 is turned on, there is no need to give cpu0_hotplug kernel 2238 parameter and the CPU0 hotplug feature is enabled by default. 2239 2240 Please note: there are two known CPU0 dependencies if you want 2241 to enable the CPU0 hotplug feature either by this switch or by 2242 cpu0_hotplug kernel parameter. 2243 2244 First, resume from hibernate or suspend always starts from CPU0. 2245 So hibernate and suspend are prevented if CPU0 is offline. 2246 2247 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2248 offline if any interrupt can not migrate out of CPU0. There may 2249 be other CPU0 dependencies. 2250 2251 Please make sure the dependencies are under your control before 2252 you enable this feature. 2253 2254 Say N if you don't want to enable CPU0 hotplug feature by default. 2255 You still can enable the CPU0 hotplug feature at boot by kernel 2256 parameter cpu0_hotplug. 2257 2258config DEBUG_HOTPLUG_CPU0 2259 def_bool n 2260 prompt "Debug CPU0 hotplug" 2261 depends on HOTPLUG_CPU 2262 ---help--- 2263 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2264 soon as possible and boots up userspace with CPU0 offlined. User 2265 can online CPU0 back after boot time. 2266 2267 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2268 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2269 compilation or giving cpu0_hotplug kernel parameter at boot. 2270 2271 If unsure, say N. 2272 2273config COMPAT_VDSO 2274 def_bool n 2275 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2276 depends on COMPAT_32 2277 ---help--- 2278 Certain buggy versions of glibc will crash if they are 2279 presented with a 32-bit vDSO that is not mapped at the address 2280 indicated in its segment table. 2281 2282 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2283 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2284 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2285 the only released version with the bug, but OpenSUSE 9 2286 contains a buggy "glibc 2.3.2". 2287 2288 The symptom of the bug is that everything crashes on startup, saying: 2289 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2290 2291 Saying Y here changes the default value of the vdso32 boot 2292 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2293 This works around the glibc bug but hurts performance. 2294 2295 If unsure, say N: if you are compiling your own kernel, you 2296 are unlikely to be using a buggy version of glibc. 2297 2298choice 2299 prompt "vsyscall table for legacy applications" 2300 depends on X86_64 2301 default LEGACY_VSYSCALL_EMULATE 2302 help 2303 Legacy user code that does not know how to find the vDSO expects 2304 to be able to issue three syscalls by calling fixed addresses in 2305 kernel space. Since this location is not randomized with ASLR, 2306 it can be used to assist security vulnerability exploitation. 2307 2308 This setting can be changed at boot time via the kernel command 2309 line parameter vsyscall=[emulate|none]. 2310 2311 On a system with recent enough glibc (2.14 or newer) and no 2312 static binaries, you can say None without a performance penalty 2313 to improve security. 2314 2315 If unsure, select "Emulate". 2316 2317 config LEGACY_VSYSCALL_EMULATE 2318 bool "Emulate" 2319 help 2320 The kernel traps and emulates calls into the fixed 2321 vsyscall address mapping. This makes the mapping 2322 non-executable, but it still contains known contents, 2323 which could be used in certain rare security vulnerability 2324 exploits. This configuration is recommended when userspace 2325 still uses the vsyscall area. 2326 2327 config LEGACY_VSYSCALL_NONE 2328 bool "None" 2329 help 2330 There will be no vsyscall mapping at all. This will 2331 eliminate any risk of ASLR bypass due to the vsyscall 2332 fixed address mapping. Attempts to use the vsyscalls 2333 will be reported to dmesg, so that either old or 2334 malicious userspace programs can be identified. 2335 2336endchoice 2337 2338config CMDLINE_BOOL 2339 bool "Built-in kernel command line" 2340 ---help--- 2341 Allow for specifying boot arguments to the kernel at 2342 build time. On some systems (e.g. embedded ones), it is 2343 necessary or convenient to provide some or all of the 2344 kernel boot arguments with the kernel itself (that is, 2345 to not rely on the boot loader to provide them.) 2346 2347 To compile command line arguments into the kernel, 2348 set this option to 'Y', then fill in the 2349 boot arguments in CONFIG_CMDLINE. 2350 2351 Systems with fully functional boot loaders (i.e. non-embedded) 2352 should leave this option set to 'N'. 2353 2354config CMDLINE 2355 string "Built-in kernel command string" 2356 depends on CMDLINE_BOOL 2357 default "" 2358 ---help--- 2359 Enter arguments here that should be compiled into the kernel 2360 image and used at boot time. If the boot loader provides a 2361 command line at boot time, it is appended to this string to 2362 form the full kernel command line, when the system boots. 2363 2364 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2365 change this behavior. 2366 2367 In most cases, the command line (whether built-in or provided 2368 by the boot loader) should specify the device for the root 2369 file system. 2370 2371config CMDLINE_OVERRIDE 2372 bool "Built-in command line overrides boot loader arguments" 2373 depends on CMDLINE_BOOL 2374 ---help--- 2375 Set this option to 'Y' to have the kernel ignore the boot loader 2376 command line, and use ONLY the built-in command line. 2377 2378 This is used to work around broken boot loaders. This should 2379 be set to 'N' under normal conditions. 2380 2381config MODIFY_LDT_SYSCALL 2382 bool "Enable the LDT (local descriptor table)" if EXPERT 2383 default y 2384 ---help--- 2385 Linux can allow user programs to install a per-process x86 2386 Local Descriptor Table (LDT) using the modify_ldt(2) system 2387 call. This is required to run 16-bit or segmented code such as 2388 DOSEMU or some Wine programs. It is also used by some very old 2389 threading libraries. 2390 2391 Enabling this feature adds a small amount of overhead to 2392 context switches and increases the low-level kernel attack 2393 surface. Disabling it removes the modify_ldt(2) system call. 2394 2395 Saying 'N' here may make sense for embedded or server kernels. 2396 2397source "kernel/livepatch/Kconfig" 2398 2399endmenu 2400 2401config ARCH_HAS_ADD_PAGES 2402 def_bool y 2403 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2404 2405config ARCH_ENABLE_MEMORY_HOTPLUG 2406 def_bool y 2407 depends on X86_64 || (X86_32 && HIGHMEM) 2408 2409config ARCH_ENABLE_MEMORY_HOTREMOVE 2410 def_bool y 2411 depends on MEMORY_HOTPLUG 2412 2413config USE_PERCPU_NUMA_NODE_ID 2414 def_bool y 2415 depends on NUMA 2416 2417config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2418 def_bool y 2419 depends on X86_64 || X86_PAE 2420 2421config ARCH_ENABLE_HUGEPAGE_MIGRATION 2422 def_bool y 2423 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2424 2425config ARCH_ENABLE_THP_MIGRATION 2426 def_bool y 2427 depends on X86_64 && TRANSPARENT_HUGEPAGE 2428 2429menu "Power management and ACPI options" 2430 2431config ARCH_HIBERNATION_HEADER 2432 def_bool y 2433 depends on X86_64 && HIBERNATION 2434 2435source "kernel/power/Kconfig" 2436 2437source "drivers/acpi/Kconfig" 2438 2439source "drivers/sfi/Kconfig" 2440 2441config X86_APM_BOOT 2442 def_bool y 2443 depends on APM 2444 2445menuconfig APM 2446 tristate "APM (Advanced Power Management) BIOS support" 2447 depends on X86_32 && PM_SLEEP 2448 ---help--- 2449 APM is a BIOS specification for saving power using several different 2450 techniques. This is mostly useful for battery powered laptops with 2451 APM compliant BIOSes. If you say Y here, the system time will be 2452 reset after a RESUME operation, the /proc/apm device will provide 2453 battery status information, and user-space programs will receive 2454 notification of APM "events" (e.g. battery status change). 2455 2456 If you select "Y" here, you can disable actual use of the APM 2457 BIOS by passing the "apm=off" option to the kernel at boot time. 2458 2459 Note that the APM support is almost completely disabled for 2460 machines with more than one CPU. 2461 2462 In order to use APM, you will need supporting software. For location 2463 and more information, read <file:Documentation/power/apm-acpi.txt> 2464 and the Battery Powered Linux mini-HOWTO, available from 2465 <http://www.tldp.org/docs.html#howto>. 2466 2467 This driver does not spin down disk drives (see the hdparm(8) 2468 manpage ("man 8 hdparm") for that), and it doesn't turn off 2469 VESA-compliant "green" monitors. 2470 2471 This driver does not support the TI 4000M TravelMate and the ACER 2472 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2473 desktop machines also don't have compliant BIOSes, and this driver 2474 may cause those machines to panic during the boot phase. 2475 2476 Generally, if you don't have a battery in your machine, there isn't 2477 much point in using this driver and you should say N. If you get 2478 random kernel OOPSes or reboots that don't seem to be related to 2479 anything, try disabling/enabling this option (or disabling/enabling 2480 APM in your BIOS). 2481 2482 Some other things you should try when experiencing seemingly random, 2483 "weird" problems: 2484 2485 1) make sure that you have enough swap space and that it is 2486 enabled. 2487 2) pass the "no-hlt" option to the kernel 2488 3) switch on floating point emulation in the kernel and pass 2489 the "no387" option to the kernel 2490 4) pass the "floppy=nodma" option to the kernel 2491 5) pass the "mem=4M" option to the kernel (thereby disabling 2492 all but the first 4 MB of RAM) 2493 6) make sure that the CPU is not over clocked. 2494 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2495 8) disable the cache from your BIOS settings 2496 9) install a fan for the video card or exchange video RAM 2497 10) install a better fan for the CPU 2498 11) exchange RAM chips 2499 12) exchange the motherboard. 2500 2501 To compile this driver as a module, choose M here: the 2502 module will be called apm. 2503 2504if APM 2505 2506config APM_IGNORE_USER_SUSPEND 2507 bool "Ignore USER SUSPEND" 2508 ---help--- 2509 This option will ignore USER SUSPEND requests. On machines with a 2510 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2511 series notebooks, it is necessary to say Y because of a BIOS bug. 2512 2513config APM_DO_ENABLE 2514 bool "Enable PM at boot time" 2515 ---help--- 2516 Enable APM features at boot time. From page 36 of the APM BIOS 2517 specification: "When disabled, the APM BIOS does not automatically 2518 power manage devices, enter the Standby State, enter the Suspend 2519 State, or take power saving steps in response to CPU Idle calls." 2520 This driver will make CPU Idle calls when Linux is idle (unless this 2521 feature is turned off -- see "Do CPU IDLE calls", below). This 2522 should always save battery power, but more complicated APM features 2523 will be dependent on your BIOS implementation. You may need to turn 2524 this option off if your computer hangs at boot time when using APM 2525 support, or if it beeps continuously instead of suspending. Turn 2526 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2527 T400CDT. This is off by default since most machines do fine without 2528 this feature. 2529 2530config APM_CPU_IDLE 2531 depends on CPU_IDLE 2532 bool "Make CPU Idle calls when idle" 2533 ---help--- 2534 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2535 On some machines, this can activate improved power savings, such as 2536 a slowed CPU clock rate, when the machine is idle. These idle calls 2537 are made after the idle loop has run for some length of time (e.g., 2538 333 mS). On some machines, this will cause a hang at boot time or 2539 whenever the CPU becomes idle. (On machines with more than one CPU, 2540 this option does nothing.) 2541 2542config APM_DISPLAY_BLANK 2543 bool "Enable console blanking using APM" 2544 ---help--- 2545 Enable console blanking using the APM. Some laptops can use this to 2546 turn off the LCD backlight when the screen blanker of the Linux 2547 virtual console blanks the screen. Note that this is only used by 2548 the virtual console screen blanker, and won't turn off the backlight 2549 when using the X Window system. This also doesn't have anything to 2550 do with your VESA-compliant power-saving monitor. Further, this 2551 option doesn't work for all laptops -- it might not turn off your 2552 backlight at all, or it might print a lot of errors to the console, 2553 especially if you are using gpm. 2554 2555config APM_ALLOW_INTS 2556 bool "Allow interrupts during APM BIOS calls" 2557 ---help--- 2558 Normally we disable external interrupts while we are making calls to 2559 the APM BIOS as a measure to lessen the effects of a badly behaving 2560 BIOS implementation. The BIOS should reenable interrupts if it 2561 needs to. Unfortunately, some BIOSes do not -- especially those in 2562 many of the newer IBM Thinkpads. If you experience hangs when you 2563 suspend, try setting this to Y. Otherwise, say N. 2564 2565endif # APM 2566 2567source "drivers/cpufreq/Kconfig" 2568 2569source "drivers/cpuidle/Kconfig" 2570 2571source "drivers/idle/Kconfig" 2572 2573endmenu 2574 2575 2576menu "Bus options (PCI etc.)" 2577 2578config PCI 2579 bool "PCI support" 2580 default y 2581 ---help--- 2582 Find out whether you have a PCI motherboard. PCI is the name of a 2583 bus system, i.e. the way the CPU talks to the other stuff inside 2584 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2585 VESA. If you have PCI, say Y, otherwise N. 2586 2587choice 2588 prompt "PCI access mode" 2589 depends on X86_32 && PCI 2590 default PCI_GOANY 2591 ---help--- 2592 On PCI systems, the BIOS can be used to detect the PCI devices and 2593 determine their configuration. However, some old PCI motherboards 2594 have BIOS bugs and may crash if this is done. Also, some embedded 2595 PCI-based systems don't have any BIOS at all. Linux can also try to 2596 detect the PCI hardware directly without using the BIOS. 2597 2598 With this option, you can specify how Linux should detect the 2599 PCI devices. If you choose "BIOS", the BIOS will be used, 2600 if you choose "Direct", the BIOS won't be used, and if you 2601 choose "MMConfig", then PCI Express MMCONFIG will be used. 2602 If you choose "Any", the kernel will try MMCONFIG, then the 2603 direct access method and falls back to the BIOS if that doesn't 2604 work. If unsure, go with the default, which is "Any". 2605 2606config PCI_GOBIOS 2607 bool "BIOS" 2608 2609config PCI_GOMMCONFIG 2610 bool "MMConfig" 2611 2612config PCI_GODIRECT 2613 bool "Direct" 2614 2615config PCI_GOOLPC 2616 bool "OLPC XO-1" 2617 depends on OLPC 2618 2619config PCI_GOANY 2620 bool "Any" 2621 2622endchoice 2623 2624config PCI_BIOS 2625 def_bool y 2626 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2627 2628# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2629config PCI_DIRECT 2630 def_bool y 2631 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2632 2633config PCI_MMCONFIG 2634 bool "Support mmconfig PCI config space access" if X86_64 2635 default y 2636 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2637 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2638 2639config PCI_OLPC 2640 def_bool y 2641 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2642 2643config PCI_XEN 2644 def_bool y 2645 depends on PCI && XEN 2646 select SWIOTLB_XEN 2647 2648config PCI_DOMAINS 2649 def_bool y 2650 depends on PCI 2651 2652config MMCONF_FAM10H 2653 def_bool y 2654 depends on X86_64 && PCI_MMCONFIG && ACPI 2655 2656config PCI_CNB20LE_QUIRK 2657 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2658 depends on PCI 2659 help 2660 Read the PCI windows out of the CNB20LE host bridge. This allows 2661 PCI hotplug to work on systems with the CNB20LE chipset which do 2662 not have ACPI. 2663 2664 There's no public spec for this chipset, and this functionality 2665 is known to be incomplete. 2666 2667 You should say N unless you know you need this. 2668 2669source "drivers/pci/Kconfig" 2670 2671config ISA_BUS 2672 bool "ISA bus support on modern systems" if EXPERT 2673 help 2674 Expose ISA bus device drivers and options available for selection and 2675 configuration. Enable this option if your target machine has an ISA 2676 bus. ISA is an older system, displaced by PCI and newer bus 2677 architectures -- if your target machine is modern, it probably does 2678 not have an ISA bus. 2679 2680 If unsure, say N. 2681 2682# x86_64 have no ISA slots, but can have ISA-style DMA. 2683config ISA_DMA_API 2684 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2685 default y 2686 help 2687 Enables ISA-style DMA support for devices requiring such controllers. 2688 If unsure, say Y. 2689 2690if X86_32 2691 2692config ISA 2693 bool "ISA support" 2694 ---help--- 2695 Find out whether you have ISA slots on your motherboard. ISA is the 2696 name of a bus system, i.e. the way the CPU talks to the other stuff 2697 inside your box. Other bus systems are PCI, EISA, MicroChannel 2698 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2699 newer boards don't support it. If you have ISA, say Y, otherwise N. 2700 2701config EISA 2702 bool "EISA support" 2703 depends on ISA 2704 ---help--- 2705 The Extended Industry Standard Architecture (EISA) bus was 2706 developed as an open alternative to the IBM MicroChannel bus. 2707 2708 The EISA bus provided some of the features of the IBM MicroChannel 2709 bus while maintaining backward compatibility with cards made for 2710 the older ISA bus. The EISA bus saw limited use between 1988 and 2711 1995 when it was made obsolete by the PCI bus. 2712 2713 Say Y here if you are building a kernel for an EISA-based machine. 2714 2715 Otherwise, say N. 2716 2717source "drivers/eisa/Kconfig" 2718 2719config SCx200 2720 tristate "NatSemi SCx200 support" 2721 ---help--- 2722 This provides basic support for National Semiconductor's 2723 (now AMD's) Geode processors. The driver probes for the 2724 PCI-IDs of several on-chip devices, so its a good dependency 2725 for other scx200_* drivers. 2726 2727 If compiled as a module, the driver is named scx200. 2728 2729config SCx200HR_TIMER 2730 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2731 depends on SCx200 2732 default y 2733 ---help--- 2734 This driver provides a clocksource built upon the on-chip 2735 27MHz high-resolution timer. Its also a workaround for 2736 NSC Geode SC-1100's buggy TSC, which loses time when the 2737 processor goes idle (as is done by the scheduler). The 2738 other workaround is idle=poll boot option. 2739 2740config OLPC 2741 bool "One Laptop Per Child support" 2742 depends on !X86_PAE 2743 select GPIOLIB 2744 select OF 2745 select OF_PROMTREE 2746 select IRQ_DOMAIN 2747 ---help--- 2748 Add support for detecting the unique features of the OLPC 2749 XO hardware. 2750 2751config OLPC_XO1_PM 2752 bool "OLPC XO-1 Power Management" 2753 depends on OLPC && MFD_CS5535 && PM_SLEEP 2754 select MFD_CORE 2755 ---help--- 2756 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2757 2758config OLPC_XO1_RTC 2759 bool "OLPC XO-1 Real Time Clock" 2760 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2761 ---help--- 2762 Add support for the XO-1 real time clock, which can be used as a 2763 programmable wakeup source. 2764 2765config OLPC_XO1_SCI 2766 bool "OLPC XO-1 SCI extras" 2767 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2768 depends on INPUT=y 2769 select POWER_SUPPLY 2770 ---help--- 2771 Add support for SCI-based features of the OLPC XO-1 laptop: 2772 - EC-driven system wakeups 2773 - Power button 2774 - Ebook switch 2775 - Lid switch 2776 - AC adapter status updates 2777 - Battery status updates 2778 2779config OLPC_XO15_SCI 2780 bool "OLPC XO-1.5 SCI extras" 2781 depends on OLPC && ACPI 2782 select POWER_SUPPLY 2783 ---help--- 2784 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2785 - EC-driven system wakeups 2786 - AC adapter status updates 2787 - Battery status updates 2788 2789config ALIX 2790 bool "PCEngines ALIX System Support (LED setup)" 2791 select GPIOLIB 2792 ---help--- 2793 This option enables system support for the PCEngines ALIX. 2794 At present this just sets up LEDs for GPIO control on 2795 ALIX2/3/6 boards. However, other system specific setup should 2796 get added here. 2797 2798 Note: You must still enable the drivers for GPIO and LED support 2799 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2800 2801 Note: You have to set alix.force=1 for boards with Award BIOS. 2802 2803config NET5501 2804 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2805 select GPIOLIB 2806 ---help--- 2807 This option enables system support for the Soekris Engineering net5501. 2808 2809config GEOS 2810 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2811 select GPIOLIB 2812 depends on DMI 2813 ---help--- 2814 This option enables system support for the Traverse Technologies GEOS. 2815 2816config TS5500 2817 bool "Technologic Systems TS-5500 platform support" 2818 depends on MELAN 2819 select CHECK_SIGNATURE 2820 select NEW_LEDS 2821 select LEDS_CLASS 2822 ---help--- 2823 This option enables system support for the Technologic Systems TS-5500. 2824 2825endif # X86_32 2826 2827config AMD_NB 2828 def_bool y 2829 depends on CPU_SUP_AMD && PCI 2830 2831source "drivers/pcmcia/Kconfig" 2832 2833config RAPIDIO 2834 tristate "RapidIO support" 2835 depends on PCI 2836 default n 2837 help 2838 If enabled this option will include drivers and the core 2839 infrastructure code to support RapidIO interconnect devices. 2840 2841source "drivers/rapidio/Kconfig" 2842 2843config X86_SYSFB 2844 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2845 help 2846 Firmwares often provide initial graphics framebuffers so the BIOS, 2847 bootloader or kernel can show basic video-output during boot for 2848 user-guidance and debugging. Historically, x86 used the VESA BIOS 2849 Extensions and EFI-framebuffers for this, which are mostly limited 2850 to x86. 2851 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2852 framebuffers so the new generic system-framebuffer drivers can be 2853 used on x86. If the framebuffer is not compatible with the generic 2854 modes, it is adverticed as fallback platform framebuffer so legacy 2855 drivers like efifb, vesafb and uvesafb can pick it up. 2856 If this option is not selected, all system framebuffers are always 2857 marked as fallback platform framebuffers as usual. 2858 2859 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2860 not be able to pick up generic system framebuffers if this option 2861 is selected. You are highly encouraged to enable simplefb as 2862 replacement if you select this option. simplefb can correctly deal 2863 with generic system framebuffers. But you should still keep vesafb 2864 and others enabled as fallback if a system framebuffer is 2865 incompatible with simplefb. 2866 2867 If unsure, say Y. 2868 2869endmenu 2870 2871 2872menu "Executable file formats / Emulations" 2873 2874source "fs/Kconfig.binfmt" 2875 2876config IA32_EMULATION 2877 bool "IA32 Emulation" 2878 depends on X86_64 2879 select ARCH_WANT_OLD_COMPAT_IPC 2880 select BINFMT_ELF 2881 select COMPAT_BINFMT_ELF 2882 select COMPAT_OLD_SIGACTION 2883 ---help--- 2884 Include code to run legacy 32-bit programs under a 2885 64-bit kernel. You should likely turn this on, unless you're 2886 100% sure that you don't have any 32-bit programs left. 2887 2888config IA32_AOUT 2889 tristate "IA32 a.out support" 2890 depends on IA32_EMULATION 2891 ---help--- 2892 Support old a.out binaries in the 32bit emulation. 2893 2894config X86_X32 2895 bool "x32 ABI for 64-bit mode" 2896 depends on X86_64 2897 ---help--- 2898 Include code to run binaries for the x32 native 32-bit ABI 2899 for 64-bit processors. An x32 process gets access to the 2900 full 64-bit register file and wide data path while leaving 2901 pointers at 32 bits for smaller memory footprint. 2902 2903 You will need a recent binutils (2.22 or later) with 2904 elf32_x86_64 support enabled to compile a kernel with this 2905 option set. 2906 2907config COMPAT_32 2908 def_bool y 2909 depends on IA32_EMULATION || X86_32 2910 select HAVE_UID16 2911 select OLD_SIGSUSPEND3 2912 2913config COMPAT 2914 def_bool y 2915 depends on IA32_EMULATION || X86_X32 2916 2917if COMPAT 2918config COMPAT_FOR_U64_ALIGNMENT 2919 def_bool y 2920 2921config SYSVIPC_COMPAT 2922 def_bool y 2923 depends on SYSVIPC 2924endif 2925 2926endmenu 2927 2928 2929config HAVE_ATOMIC_IOMAP 2930 def_bool y 2931 depends on X86_32 2932 2933config X86_DEV_DMA_OPS 2934 bool 2935 depends on X86_64 || STA2X11 2936 2937config X86_DMA_REMAP 2938 bool 2939 depends on STA2X11 2940 2941config HAVE_GENERIC_GUP 2942 def_bool y 2943 2944source "net/Kconfig" 2945 2946source "drivers/Kconfig" 2947 2948source "drivers/firmware/Kconfig" 2949 2950source "fs/Kconfig" 2951 2952source "arch/x86/Kconfig.debug" 2953 2954source "security/Kconfig" 2955 2956source "crypto/Kconfig" 2957 2958source "arch/x86/kvm/Kconfig" 2959 2960source "lib/Kconfig" 2961