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 NEED_DMA_MAP_STATE 32 select SWIOTLB 33 select X86_DEV_DMA_OPS 34 select ARCH_HAS_SYSCALL_WRAPPER 35 36# 37# Arch settings 38# 39# ( Note that options that are marked 'if X86_64' could in principle be 40# ported to 32-bit as well. ) 41# 42config X86 43 def_bool y 44 # 45 # Note: keep this list sorted alphabetically 46 # 47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 49 select ANON_INODES 50 select ARCH_CLOCKSOURCE_DATA 51 select ARCH_DISCARD_MEMBLOCK 52 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 53 select ARCH_HAS_DEBUG_VIRTUAL 54 select ARCH_HAS_DEVMEM_IS_ALLOWED 55 select ARCH_HAS_ELF_RANDOMIZE 56 select ARCH_HAS_FAST_MULTIPLIER 57 select ARCH_HAS_FILTER_PGPROT 58 select ARCH_HAS_FORTIFY_SOURCE 59 select ARCH_HAS_GCOV_PROFILE_ALL 60 select ARCH_HAS_KCOV if X86_64 61 select ARCH_HAS_MEMBARRIER_SYNC_CORE 62 select ARCH_HAS_PMEM_API if X86_64 63 select ARCH_HAS_PTE_SPECIAL 64 select ARCH_HAS_REFCOUNT 65 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 66 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 67 select ARCH_HAS_SET_MEMORY 68 select ARCH_HAS_SG_CHAIN 69 select ARCH_HAS_STRICT_KERNEL_RWX 70 select ARCH_HAS_STRICT_MODULE_RWX 71 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 72 select ARCH_HAS_UBSAN_SANITIZE_ALL 73 select ARCH_HAS_ZONE_DEVICE if X86_64 74 select ARCH_HAVE_NMI_SAFE_CMPXCHG 75 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 76 select ARCH_MIGHT_HAVE_PC_PARPORT 77 select ARCH_MIGHT_HAVE_PC_SERIO 78 select ARCH_SUPPORTS_ACPI 79 select ARCH_SUPPORTS_ATOMIC_RMW 80 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 81 select ARCH_USE_BUILTIN_BSWAP 82 select ARCH_USE_QUEUED_RWLOCKS 83 select ARCH_USE_QUEUED_SPINLOCKS 84 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 85 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 86 select ARCH_WANTS_THP_SWAP if X86_64 87 select BUILDTIME_EXTABLE_SORT 88 select CLKEVT_I8253 89 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 90 select CLOCKSOURCE_WATCHDOG 91 select DCACHE_WORD_ACCESS 92 select DMA_DIRECT_OPS 93 select EDAC_ATOMIC_SCRUB 94 select EDAC_SUPPORT 95 select GENERIC_CLOCKEVENTS 96 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 97 select GENERIC_CLOCKEVENTS_MIN_ADJUST 98 select GENERIC_CMOS_UPDATE 99 select GENERIC_CPU_AUTOPROBE 100 select GENERIC_CPU_VULNERABILITIES 101 select GENERIC_EARLY_IOREMAP 102 select GENERIC_FIND_FIRST_BIT 103 select GENERIC_IOMAP 104 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 105 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 106 select GENERIC_IRQ_MIGRATION if SMP 107 select GENERIC_IRQ_PROBE 108 select GENERIC_IRQ_RESERVATION_MODE 109 select GENERIC_IRQ_SHOW 110 select GENERIC_PENDING_IRQ if SMP 111 select GENERIC_SMP_IDLE_THREAD 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select GENERIC_TIME_VSYSCALL 115 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 116 select HAVE_ACPI_APEI if ACPI 117 select HAVE_ACPI_APEI_NMI if ACPI 118 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 119 select HAVE_ARCH_AUDITSYSCALL 120 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 121 select HAVE_ARCH_JUMP_LABEL 122 select HAVE_ARCH_KASAN if X86_64 123 select HAVE_ARCH_KGDB 124 select HAVE_ARCH_MMAP_RND_BITS if MMU 125 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 126 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 127 select HAVE_ARCH_PREL32_RELOCATIONS 128 select HAVE_ARCH_SECCOMP_FILTER 129 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 130 select HAVE_ARCH_TRACEHOOK 131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 133 select HAVE_ARCH_VMAP_STACK if X86_64 134 select HAVE_ARCH_WITHIN_STACK_FRAMES 135 select HAVE_CMPXCHG_DOUBLE 136 select HAVE_CMPXCHG_LOCAL 137 select HAVE_CONTEXT_TRACKING if X86_64 138 select HAVE_COPY_THREAD_TLS 139 select HAVE_C_RECORDMCOUNT 140 select HAVE_DEBUG_KMEMLEAK 141 select HAVE_DEBUG_STACKOVERFLOW 142 select HAVE_DMA_CONTIGUOUS 143 select HAVE_DYNAMIC_FTRACE 144 select HAVE_DYNAMIC_FTRACE_WITH_REGS 145 select HAVE_EBPF_JIT 146 select HAVE_EFFICIENT_UNALIGNED_ACCESS 147 select HAVE_EXIT_THREAD 148 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 149 select HAVE_FTRACE_MCOUNT_RECORD 150 select HAVE_FUNCTION_GRAPH_TRACER 151 select HAVE_FUNCTION_TRACER 152 select HAVE_GCC_PLUGINS 153 select HAVE_HW_BREAKPOINT 154 select HAVE_IDE 155 select HAVE_IOREMAP_PROT 156 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 157 select HAVE_IRQ_TIME_ACCOUNTING 158 select HAVE_KERNEL_BZIP2 159 select HAVE_KERNEL_GZIP 160 select HAVE_KERNEL_LZ4 161 select HAVE_KERNEL_LZMA 162 select HAVE_KERNEL_LZO 163 select HAVE_KERNEL_XZ 164 select HAVE_KPROBES 165 select HAVE_KPROBES_ON_FTRACE 166 select HAVE_FUNCTION_ERROR_INJECTION 167 select HAVE_KRETPROBES 168 select HAVE_KVM 169 select HAVE_LIVEPATCH if X86_64 170 select HAVE_MEMBLOCK 171 select HAVE_MEMBLOCK_NODE_MAP 172 select HAVE_MIXED_BREAKPOINTS_REGS 173 select HAVE_MOD_ARCH_SPECIFIC 174 select HAVE_NMI 175 select HAVE_OPROFILE 176 select HAVE_OPTPROBES 177 select HAVE_PCSPKR_PLATFORM 178 select HAVE_PERF_EVENTS 179 select HAVE_PERF_EVENTS_NMI 180 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 181 select HAVE_PERF_REGS 182 select HAVE_PERF_USER_STACK_DUMP 183 select HAVE_RCU_TABLE_FREE 184 select HAVE_REGS_AND_STACK_ACCESS_API 185 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 186 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 187 select HAVE_STACK_VALIDATION if X86_64 188 select HAVE_RSEQ 189 select HAVE_SYSCALL_TRACEPOINTS 190 select HAVE_UNSTABLE_SCHED_CLOCK 191 select HAVE_USER_RETURN_NOTIFIER 192 select HOTPLUG_SMT if SMP 193 select IRQ_FORCED_THREADING 194 select NEED_SG_DMA_LENGTH 195 select PCI_LOCKLESS_CONFIG 196 select PERF_EVENTS 197 select RTC_LIB 198 select RTC_MC146818_LIB 199 select SPARSE_IRQ 200 select SRCU 201 select SYSCTL_EXCEPTION_TRACE 202 select THREAD_INFO_IN_TASK 203 select USER_STACKTRACE_SUPPORT 204 select VIRT_TO_BUS 205 select X86_FEATURE_NAMES if PROC_FS 206 207config INSTRUCTION_DECODER 208 def_bool y 209 depends on KPROBES || PERF_EVENTS || UPROBES 210 211config OUTPUT_FORMAT 212 string 213 default "elf32-i386" if X86_32 214 default "elf64-x86-64" if X86_64 215 216config ARCH_DEFCONFIG 217 string 218 default "arch/x86/configs/i386_defconfig" if X86_32 219 default "arch/x86/configs/x86_64_defconfig" if X86_64 220 221config LOCKDEP_SUPPORT 222 def_bool y 223 224config STACKTRACE_SUPPORT 225 def_bool y 226 227config MMU 228 def_bool y 229 230config ARCH_MMAP_RND_BITS_MIN 231 default 28 if 64BIT 232 default 8 233 234config ARCH_MMAP_RND_BITS_MAX 235 default 32 if 64BIT 236 default 16 237 238config ARCH_MMAP_RND_COMPAT_BITS_MIN 239 default 8 240 241config ARCH_MMAP_RND_COMPAT_BITS_MAX 242 default 16 243 244config SBUS 245 bool 246 247config GENERIC_ISA_DMA 248 def_bool y 249 depends on ISA_DMA_API 250 251config GENERIC_BUG 252 def_bool y 253 depends on BUG 254 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 255 256config GENERIC_BUG_RELATIVE_POINTERS 257 bool 258 259config GENERIC_HWEIGHT 260 def_bool y 261 262config ARCH_MAY_HAVE_PC_FDC 263 def_bool y 264 depends on ISA_DMA_API 265 266config RWSEM_XCHGADD_ALGORITHM 267 def_bool y 268 269config GENERIC_CALIBRATE_DELAY 270 def_bool y 271 272config ARCH_HAS_CPU_RELAX 273 def_bool y 274 275config ARCH_HAS_CACHE_LINE_SIZE 276 def_bool y 277 278config ARCH_HAS_FILTER_PGPROT 279 def_bool y 280 281config HAVE_SETUP_PER_CPU_AREA 282 def_bool y 283 284config NEED_PER_CPU_EMBED_FIRST_CHUNK 285 def_bool y 286 287config NEED_PER_CPU_PAGE_FIRST_CHUNK 288 def_bool y 289 290config ARCH_HIBERNATION_POSSIBLE 291 def_bool y 292 293config ARCH_SUSPEND_POSSIBLE 294 def_bool y 295 296config ARCH_WANT_HUGE_PMD_SHARE 297 def_bool y 298 299config ARCH_WANT_GENERAL_HUGETLB 300 def_bool y 301 302config ZONE_DMA32 303 def_bool y if X86_64 304 305config AUDIT_ARCH 306 def_bool y if X86_64 307 308config ARCH_SUPPORTS_OPTIMIZED_INLINING 309 def_bool y 310 311config ARCH_SUPPORTS_DEBUG_PAGEALLOC 312 def_bool y 313 314config KASAN_SHADOW_OFFSET 315 hex 316 depends on KASAN 317 default 0xdffffc0000000000 318 319config HAVE_INTEL_TXT 320 def_bool y 321 depends on INTEL_IOMMU && ACPI 322 323config X86_32_SMP 324 def_bool y 325 depends on X86_32 && SMP 326 327config X86_64_SMP 328 def_bool y 329 depends on X86_64 && SMP 330 331config X86_32_LAZY_GS 332 def_bool y 333 depends on X86_32 && !STACKPROTECTOR 334 335config ARCH_SUPPORTS_UPROBES 336 def_bool y 337 338config FIX_EARLYCON_MEM 339 def_bool y 340 341config DYNAMIC_PHYSICAL_MASK 342 bool 343 344config PGTABLE_LEVELS 345 int 346 default 5 if X86_5LEVEL 347 default 4 if X86_64 348 default 3 if X86_PAE 349 default 2 350 351config CC_HAS_SANE_STACKPROTECTOR 352 bool 353 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 354 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 355 help 356 We have to make sure stack protector is unconditionally disabled if 357 the compiler produces broken code. 358 359menu "Processor type and features" 360 361config ZONE_DMA 362 bool "DMA memory allocation support" if EXPERT 363 default y 364 help 365 DMA memory allocation support allows devices with less than 32-bit 366 addressing to allocate within the first 16MB of address space. 367 Disable if no such devices will be used. 368 369 If unsure, say Y. 370 371config SMP 372 bool "Symmetric multi-processing support" 373 ---help--- 374 This enables support for systems with more than one CPU. If you have 375 a system with only one CPU, say N. If you have a system with more 376 than one CPU, say Y. 377 378 If you say N here, the kernel will run on uni- and multiprocessor 379 machines, but will use only one CPU of a multiprocessor machine. If 380 you say Y here, the kernel will run on many, but not all, 381 uniprocessor machines. On a uniprocessor machine, the kernel 382 will run faster if you say N here. 383 384 Note that if you say Y here and choose architecture "586" or 385 "Pentium" under "Processor family", the kernel will not work on 486 386 architectures. Similarly, multiprocessor kernels for the "PPro" 387 architecture may not work on all Pentium based boards. 388 389 People using multiprocessor machines who say Y here should also say 390 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 391 Management" code will be disabled if you say Y here. 392 393 See also <file:Documentation/x86/i386/IO-APIC.txt>, 394 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 395 <http://www.tldp.org/docs.html#howto>. 396 397 If you don't know what to do here, say N. 398 399config X86_FEATURE_NAMES 400 bool "Processor feature human-readable names" if EMBEDDED 401 default y 402 ---help--- 403 This option compiles in a table of x86 feature bits and corresponding 404 names. This is required to support /proc/cpuinfo and a few kernel 405 messages. You can disable this to save space, at the expense of 406 making those few kernel messages show numeric feature bits instead. 407 408 If in doubt, say Y. 409 410config X86_X2APIC 411 bool "Support x2apic" 412 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 413 ---help--- 414 This enables x2apic support on CPUs that have this feature. 415 416 This allows 32-bit apic IDs (so it can support very large systems), 417 and accesses the local apic via MSRs not via mmio. 418 419 If you don't know what to do here, say N. 420 421config X86_MPPARSE 422 bool "Enable MPS table" if ACPI || SFI 423 default y 424 depends on X86_LOCAL_APIC 425 ---help--- 426 For old smp systems that do not have proper acpi support. Newer systems 427 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 428 429config GOLDFISH 430 def_bool y 431 depends on X86_GOLDFISH 432 433config RETPOLINE 434 bool "Avoid speculative indirect branches in kernel" 435 default y 436 select STACK_VALIDATION if HAVE_STACK_VALIDATION 437 help 438 Compile kernel with the retpoline compiler options to guard against 439 kernel-to-user data leaks by avoiding speculative indirect 440 branches. Requires a compiler with -mindirect-branch=thunk-extern 441 support for full protection. The kernel may run slower. 442 443 Without compiler support, at least indirect branches in assembler 444 code are eliminated. Since this includes the syscall entry path, 445 it is not entirely pointless. 446 447config INTEL_RDT 448 bool "Intel Resource Director Technology support" 449 default n 450 depends on X86 && CPU_SUP_INTEL 451 select KERNFS 452 help 453 Select to enable resource allocation and monitoring which are 454 sub-features of Intel Resource Director Technology(RDT). More 455 information about RDT can be found in the Intel x86 456 Architecture Software Developer Manual. 457 458 Say N if unsure. 459 460if X86_32 461config X86_BIGSMP 462 bool "Support for big SMP systems with more than 8 CPUs" 463 depends on SMP 464 ---help--- 465 This option is needed for the systems that have more than 8 CPUs 466 467config X86_EXTENDED_PLATFORM 468 bool "Support for extended (non-PC) x86 platforms" 469 default y 470 ---help--- 471 If you disable this option then the kernel will only support 472 standard PC platforms. (which covers the vast majority of 473 systems out there.) 474 475 If you enable this option then you'll be able to select support 476 for the following (non-PC) 32 bit x86 platforms: 477 Goldfish (Android emulator) 478 AMD Elan 479 RDC R-321x SoC 480 SGI 320/540 (Visual Workstation) 481 STA2X11-based (e.g. Northville) 482 Moorestown MID devices 483 484 If you have one of these systems, or if you want to build a 485 generic distribution kernel, say Y here - otherwise say N. 486endif 487 488if X86_64 489config X86_EXTENDED_PLATFORM 490 bool "Support for extended (non-PC) x86 platforms" 491 default y 492 ---help--- 493 If you disable this option then the kernel will only support 494 standard PC platforms. (which covers the vast majority of 495 systems out there.) 496 497 If you enable this option then you'll be able to select support 498 for the following (non-PC) 64 bit x86 platforms: 499 Numascale NumaChip 500 ScaleMP vSMP 501 SGI Ultraviolet 502 503 If you have one of these systems, or if you want to build a 504 generic distribution kernel, say Y here - otherwise say N. 505endif 506# This is an alphabetically sorted list of 64 bit extended platforms 507# Please maintain the alphabetic order if and when there are additions 508config X86_NUMACHIP 509 bool "Numascale NumaChip" 510 depends on X86_64 511 depends on X86_EXTENDED_PLATFORM 512 depends on NUMA 513 depends on SMP 514 depends on X86_X2APIC 515 depends on PCI_MMCONFIG 516 ---help--- 517 Adds support for Numascale NumaChip large-SMP systems. Needed to 518 enable more than ~168 cores. 519 If you don't have one of these, you should say N here. 520 521config X86_VSMP 522 bool "ScaleMP vSMP" 523 select HYPERVISOR_GUEST 524 select PARAVIRT 525 depends on X86_64 && PCI 526 depends on X86_EXTENDED_PLATFORM 527 depends on SMP 528 ---help--- 529 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 530 supposed to run on these EM64T-based machines. Only choose this option 531 if you have one of these machines. 532 533config X86_UV 534 bool "SGI Ultraviolet" 535 depends on X86_64 536 depends on X86_EXTENDED_PLATFORM 537 depends on NUMA 538 depends on EFI 539 depends on X86_X2APIC 540 depends on PCI 541 ---help--- 542 This option is needed in order to support SGI Ultraviolet systems. 543 If you don't have one of these, you should say N here. 544 545# Following is an alphabetically sorted list of 32 bit extended platforms 546# Please maintain the alphabetic order if and when there are additions 547 548config X86_GOLDFISH 549 bool "Goldfish (Virtual Platform)" 550 depends on X86_EXTENDED_PLATFORM 551 ---help--- 552 Enable support for the Goldfish virtual platform used primarily 553 for Android development. Unless you are building for the Android 554 Goldfish emulator say N here. 555 556config X86_INTEL_CE 557 bool "CE4100 TV platform" 558 depends on PCI 559 depends on PCI_GODIRECT 560 depends on X86_IO_APIC 561 depends on X86_32 562 depends on X86_EXTENDED_PLATFORM 563 select X86_REBOOTFIXUPS 564 select OF 565 select OF_EARLY_FLATTREE 566 ---help--- 567 Select for the Intel CE media processor (CE4100) SOC. 568 This option compiles in support for the CE4100 SOC for settop 569 boxes and media devices. 570 571config X86_INTEL_MID 572 bool "Intel MID platform support" 573 depends on X86_EXTENDED_PLATFORM 574 depends on X86_PLATFORM_DEVICES 575 depends on PCI 576 depends on X86_64 || (PCI_GOANY && X86_32) 577 depends on X86_IO_APIC 578 select SFI 579 select I2C 580 select DW_APB_TIMER 581 select APB_TIMER 582 select INTEL_SCU_IPC 583 select MFD_INTEL_MSIC 584 ---help--- 585 Select to build a kernel capable of supporting Intel MID (Mobile 586 Internet Device) platform systems which do not have the PCI legacy 587 interfaces. If you are building for a PC class system say N here. 588 589 Intel MID platforms are based on an Intel processor and chipset which 590 consume less power than most of the x86 derivatives. 591 592config X86_INTEL_QUARK 593 bool "Intel Quark platform support" 594 depends on X86_32 595 depends on X86_EXTENDED_PLATFORM 596 depends on X86_PLATFORM_DEVICES 597 depends on X86_TSC 598 depends on PCI 599 depends on PCI_GOANY 600 depends on X86_IO_APIC 601 select IOSF_MBI 602 select INTEL_IMR 603 select COMMON_CLK 604 ---help--- 605 Select to include support for Quark X1000 SoC. 606 Say Y here if you have a Quark based system such as the Arduino 607 compatible Intel Galileo. 608 609config X86_INTEL_LPSS 610 bool "Intel Low Power Subsystem Support" 611 depends on X86 && ACPI 612 select COMMON_CLK 613 select PINCTRL 614 select IOSF_MBI 615 ---help--- 616 Select to build support for Intel Low Power Subsystem such as 617 found on Intel Lynxpoint PCH. Selecting this option enables 618 things like clock tree (common clock framework) and pincontrol 619 which are needed by the LPSS peripheral drivers. 620 621config X86_AMD_PLATFORM_DEVICE 622 bool "AMD ACPI2Platform devices support" 623 depends on ACPI 624 select COMMON_CLK 625 select PINCTRL 626 ---help--- 627 Select to interpret AMD specific ACPI device to platform device 628 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 629 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 630 implemented under PINCTRL subsystem. 631 632config IOSF_MBI 633 tristate "Intel SoC IOSF Sideband support for SoC platforms" 634 depends on PCI 635 ---help--- 636 This option enables sideband register access support for Intel SoC 637 platforms. On these platforms the IOSF sideband is used in lieu of 638 MSR's for some register accesses, mostly but not limited to thermal 639 and power. Drivers may query the availability of this device to 640 determine if they need the sideband in order to work on these 641 platforms. The sideband is available on the following SoC products. 642 This list is not meant to be exclusive. 643 - BayTrail 644 - Braswell 645 - Quark 646 647 You should say Y if you are running a kernel on one of these SoC's. 648 649config IOSF_MBI_DEBUG 650 bool "Enable IOSF sideband access through debugfs" 651 depends on IOSF_MBI && DEBUG_FS 652 ---help--- 653 Select this option to expose the IOSF sideband access registers (MCR, 654 MDR, MCRX) through debugfs to write and read register information from 655 different units on the SoC. This is most useful for obtaining device 656 state information for debug and analysis. As this is a general access 657 mechanism, users of this option would have specific knowledge of the 658 device they want to access. 659 660 If you don't require the option or are in doubt, say N. 661 662config X86_RDC321X 663 bool "RDC R-321x SoC" 664 depends on X86_32 665 depends on X86_EXTENDED_PLATFORM 666 select M486 667 select X86_REBOOTFIXUPS 668 ---help--- 669 This option is needed for RDC R-321x system-on-chip, also known 670 as R-8610-(G). 671 If you don't have one of these chips, you should say N here. 672 673config X86_32_NON_STANDARD 674 bool "Support non-standard 32-bit SMP architectures" 675 depends on X86_32 && SMP 676 depends on X86_EXTENDED_PLATFORM 677 ---help--- 678 This option compiles in the bigsmp and STA2X11 default 679 subarchitectures. It is intended for a generic binary 680 kernel. If you select them all, kernel will probe it one by 681 one and will fallback to default. 682 683# Alphabetically sorted list of Non standard 32 bit platforms 684 685config X86_SUPPORTS_MEMORY_FAILURE 686 def_bool y 687 # MCE code calls memory_failure(): 688 depends on X86_MCE 689 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 690 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 691 depends on X86_64 || !SPARSEMEM 692 select ARCH_SUPPORTS_MEMORY_FAILURE 693 694config STA2X11 695 bool "STA2X11 Companion Chip Support" 696 depends on X86_32_NON_STANDARD && PCI 697 select ARCH_HAS_PHYS_TO_DMA 698 select X86_DEV_DMA_OPS 699 select X86_DMA_REMAP 700 select SWIOTLB 701 select MFD_STA2X11 702 select GPIOLIB 703 default n 704 ---help--- 705 This adds support for boards based on the STA2X11 IO-Hub, 706 a.k.a. "ConneXt". The chip is used in place of the standard 707 PC chipset, so all "standard" peripherals are missing. If this 708 option is selected the kernel will still be able to boot on 709 standard PC machines. 710 711config X86_32_IRIS 712 tristate "Eurobraille/Iris poweroff module" 713 depends on X86_32 714 ---help--- 715 The Iris machines from EuroBraille do not have APM or ACPI support 716 to shut themselves down properly. A special I/O sequence is 717 needed to do so, which is what this module does at 718 kernel shutdown. 719 720 This is only for Iris machines from EuroBraille. 721 722 If unused, say N. 723 724config SCHED_OMIT_FRAME_POINTER 725 def_bool y 726 prompt "Single-depth WCHAN output" 727 depends on X86 728 ---help--- 729 Calculate simpler /proc/<PID>/wchan values. If this option 730 is disabled then wchan values will recurse back to the 731 caller function. This provides more accurate wchan values, 732 at the expense of slightly more scheduling overhead. 733 734 If in doubt, say "Y". 735 736menuconfig HYPERVISOR_GUEST 737 bool "Linux guest support" 738 ---help--- 739 Say Y here to enable options for running Linux under various hyper- 740 visors. This option enables basic hypervisor detection and platform 741 setup. 742 743 If you say N, all options in this submenu will be skipped and 744 disabled, and Linux guest support won't be built in. 745 746if HYPERVISOR_GUEST 747 748config PARAVIRT 749 bool "Enable paravirtualization code" 750 ---help--- 751 This changes the kernel so it can modify itself when it is run 752 under a hypervisor, potentially improving performance significantly 753 over full virtualization. However, when run without a hypervisor 754 the kernel is theoretically slower and slightly larger. 755 756config PARAVIRT_DEBUG 757 bool "paravirt-ops debugging" 758 depends on PARAVIRT && DEBUG_KERNEL 759 ---help--- 760 Enable to debug paravirt_ops internals. Specifically, BUG if 761 a paravirt_op is missing when it is called. 762 763config PARAVIRT_SPINLOCKS 764 bool "Paravirtualization layer for spinlocks" 765 depends on PARAVIRT && SMP 766 ---help--- 767 Paravirtualized spinlocks allow a pvops backend to replace the 768 spinlock implementation with something virtualization-friendly 769 (for example, block the virtual CPU rather than spinning). 770 771 It has a minimal impact on native kernels and gives a nice performance 772 benefit on paravirtualized KVM / Xen kernels. 773 774 If you are unsure how to answer this question, answer Y. 775 776config QUEUED_LOCK_STAT 777 bool "Paravirt queued spinlock statistics" 778 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 779 ---help--- 780 Enable the collection of statistical data on the slowpath 781 behavior of paravirtualized queued spinlocks and report 782 them on debugfs. 783 784source "arch/x86/xen/Kconfig" 785 786config KVM_GUEST 787 bool "KVM Guest support (including kvmclock)" 788 depends on PARAVIRT 789 select PARAVIRT_CLOCK 790 default y 791 ---help--- 792 This option enables various optimizations for running under the KVM 793 hypervisor. It includes a paravirtualized clock, so that instead 794 of relying on a PIT (or probably other) emulation by the 795 underlying device model, the host provides the guest with 796 timing infrastructure such as time of day, and system time 797 798config KVM_DEBUG_FS 799 bool "Enable debug information for KVM Guests in debugfs" 800 depends on KVM_GUEST && DEBUG_FS 801 default n 802 ---help--- 803 This option enables collection of various statistics for KVM guest. 804 Statistics are displayed in debugfs filesystem. Enabling this option 805 may incur significant overhead. 806 807config PARAVIRT_TIME_ACCOUNTING 808 bool "Paravirtual steal time accounting" 809 depends on PARAVIRT 810 default n 811 ---help--- 812 Select this option to enable fine granularity task steal time 813 accounting. Time spent executing other tasks in parallel with 814 the current vCPU is discounted from the vCPU power. To account for 815 that, there can be a small performance impact. 816 817 If in doubt, say N here. 818 819config PARAVIRT_CLOCK 820 bool 821 822config JAILHOUSE_GUEST 823 bool "Jailhouse non-root cell support" 824 depends on X86_64 && PCI 825 select X86_PM_TIMER 826 ---help--- 827 This option allows to run Linux as guest in a Jailhouse non-root 828 cell. You can leave this option disabled if you only want to start 829 Jailhouse and run Linux afterwards in the root cell. 830 831endif #HYPERVISOR_GUEST 832 833config NO_BOOTMEM 834 def_bool y 835 836source "arch/x86/Kconfig.cpu" 837 838config HPET_TIMER 839 def_bool X86_64 840 prompt "HPET Timer Support" if X86_32 841 ---help--- 842 Use the IA-PC HPET (High Precision Event Timer) to manage 843 time in preference to the PIT and RTC, if a HPET is 844 present. 845 HPET is the next generation timer replacing legacy 8254s. 846 The HPET provides a stable time base on SMP 847 systems, unlike the TSC, but it is more expensive to access, 848 as it is off-chip. The interface used is documented 849 in the HPET spec, revision 1. 850 851 You can safely choose Y here. However, HPET will only be 852 activated if the platform and the BIOS support this feature. 853 Otherwise the 8254 will be used for timing services. 854 855 Choose N to continue using the legacy 8254 timer. 856 857config HPET_EMULATE_RTC 858 def_bool y 859 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 860 861config APB_TIMER 862 def_bool y if X86_INTEL_MID 863 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 864 select DW_APB_TIMER 865 depends on X86_INTEL_MID && SFI 866 help 867 APB timer is the replacement for 8254, HPET on X86 MID platforms. 868 The APBT provides a stable time base on SMP 869 systems, unlike the TSC, but it is more expensive to access, 870 as it is off-chip. APB timers are always running regardless of CPU 871 C states, they are used as per CPU clockevent device when possible. 872 873# Mark as expert because too many people got it wrong. 874# The code disables itself when not needed. 875config DMI 876 default y 877 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 878 bool "Enable DMI scanning" if EXPERT 879 ---help--- 880 Enabled scanning of DMI to identify machine quirks. Say Y 881 here unless you have verified that your setup is not 882 affected by entries in the DMI blacklist. Required by PNP 883 BIOS code. 884 885config GART_IOMMU 886 bool "Old AMD GART IOMMU support" 887 select IOMMU_HELPER 888 select SWIOTLB 889 depends on X86_64 && PCI && AMD_NB 890 ---help--- 891 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 892 GART based hardware IOMMUs. 893 894 The GART supports full DMA access for devices with 32-bit access 895 limitations, on systems with more than 3 GB. This is usually needed 896 for USB, sound, many IDE/SATA chipsets and some other devices. 897 898 Newer systems typically have a modern AMD IOMMU, supported via 899 the CONFIG_AMD_IOMMU=y config option. 900 901 In normal configurations this driver is only active when needed: 902 there's more than 3 GB of memory and the system contains a 903 32-bit limited device. 904 905 If unsure, say Y. 906 907config CALGARY_IOMMU 908 bool "IBM Calgary IOMMU support" 909 select IOMMU_HELPER 910 select SWIOTLB 911 depends on X86_64 && PCI 912 ---help--- 913 Support for hardware IOMMUs in IBM's xSeries x366 and x460 914 systems. Needed to run systems with more than 3GB of memory 915 properly with 32-bit PCI devices that do not support DAC 916 (Double Address Cycle). Calgary also supports bus level 917 isolation, where all DMAs pass through the IOMMU. This 918 prevents them from going anywhere except their intended 919 destination. This catches hard-to-find kernel bugs and 920 mis-behaving drivers and devices that do not use the DMA-API 921 properly to set up their DMA buffers. The IOMMU can be 922 turned off at boot time with the iommu=off parameter. 923 Normally the kernel will make the right choice by itself. 924 If unsure, say Y. 925 926config CALGARY_IOMMU_ENABLED_BY_DEFAULT 927 def_bool y 928 prompt "Should Calgary be enabled by default?" 929 depends on CALGARY_IOMMU 930 ---help--- 931 Should Calgary be enabled by default? if you choose 'y', Calgary 932 will be used (if it exists). If you choose 'n', Calgary will not be 933 used even if it exists. If you choose 'n' and would like to use 934 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 935 If unsure, say Y. 936 937config MAXSMP 938 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 939 depends on X86_64 && SMP && DEBUG_KERNEL 940 select CPUMASK_OFFSTACK 941 ---help--- 942 Enable maximum number of CPUS and NUMA Nodes for this architecture. 943 If unsure, say N. 944 945# 946# The maximum number of CPUs supported: 947# 948# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 949# and which can be configured interactively in the 950# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 951# 952# The ranges are different on 32-bit and 64-bit kernels, depending on 953# hardware capabilities and scalability features of the kernel. 954# 955# ( If MAXSMP is enabled we just use the highest possible value and disable 956# interactive configuration. ) 957# 958 959config NR_CPUS_RANGE_BEGIN 960 int 961 default NR_CPUS_RANGE_END if MAXSMP 962 default 1 if !SMP 963 default 2 964 965config NR_CPUS_RANGE_END 966 int 967 depends on X86_32 968 default 64 if SMP && X86_BIGSMP 969 default 8 if SMP && !X86_BIGSMP 970 default 1 if !SMP 971 972config NR_CPUS_RANGE_END 973 int 974 depends on X86_64 975 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 976 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 977 default 1 if !SMP 978 979config NR_CPUS_DEFAULT 980 int 981 depends on X86_32 982 default 32 if X86_BIGSMP 983 default 8 if SMP 984 default 1 if !SMP 985 986config NR_CPUS_DEFAULT 987 int 988 depends on X86_64 989 default 8192 if MAXSMP 990 default 64 if SMP 991 default 1 if !SMP 992 993config NR_CPUS 994 int "Maximum number of CPUs" if SMP && !MAXSMP 995 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 996 default NR_CPUS_DEFAULT 997 ---help--- 998 This allows you to specify the maximum number of CPUs which this 999 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1000 supported value is 8192, otherwise the maximum value is 512. The 1001 minimum value which makes sense is 2. 1002 1003 This is purely to save memory: each supported CPU adds about 8KB 1004 to the kernel image. 1005 1006config SCHED_SMT 1007 bool "SMT (Hyperthreading) scheduler support" 1008 depends on SMP 1009 ---help--- 1010 SMT scheduler support improves the CPU scheduler's decision making 1011 when dealing with Intel Pentium 4 chips with HyperThreading at a 1012 cost of slightly increased overhead in some places. If unsure say 1013 N here. 1014 1015config SCHED_MC 1016 def_bool y 1017 prompt "Multi-core scheduler support" 1018 depends on SMP 1019 ---help--- 1020 Multi-core scheduler support improves the CPU scheduler's decision 1021 making when dealing with multi-core CPU chips at a cost of slightly 1022 increased overhead in some places. If unsure say N here. 1023 1024config SCHED_MC_PRIO 1025 bool "CPU core priorities scheduler support" 1026 depends on SCHED_MC && CPU_SUP_INTEL 1027 select X86_INTEL_PSTATE 1028 select CPU_FREQ 1029 default y 1030 ---help--- 1031 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1032 core ordering determined at manufacturing time, which allows 1033 certain cores to reach higher turbo frequencies (when running 1034 single threaded workloads) than others. 1035 1036 Enabling this kernel feature teaches the scheduler about 1037 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1038 scheduler's CPU selection logic accordingly, so that higher 1039 overall system performance can be achieved. 1040 1041 This feature will have no effect on CPUs without this feature. 1042 1043 If unsure say Y here. 1044 1045config UP_LATE_INIT 1046 def_bool y 1047 depends on !SMP && X86_LOCAL_APIC 1048 1049config X86_UP_APIC 1050 bool "Local APIC support on uniprocessors" if !PCI_MSI 1051 default PCI_MSI 1052 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1053 ---help--- 1054 A local APIC (Advanced Programmable Interrupt Controller) is an 1055 integrated interrupt controller in the CPU. If you have a single-CPU 1056 system which has a processor with a local APIC, you can say Y here to 1057 enable and use it. If you say Y here even though your machine doesn't 1058 have a local APIC, then the kernel will still run with no slowdown at 1059 all. The local APIC supports CPU-generated self-interrupts (timer, 1060 performance counters), and the NMI watchdog which detects hard 1061 lockups. 1062 1063config X86_UP_IOAPIC 1064 bool "IO-APIC support on uniprocessors" 1065 depends on X86_UP_APIC 1066 ---help--- 1067 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1068 SMP-capable replacement for PC-style interrupt controllers. Most 1069 SMP systems and many recent uniprocessor systems have one. 1070 1071 If you have a single-CPU system with an IO-APIC, you can say Y here 1072 to use it. If you say Y here even though your machine doesn't have 1073 an IO-APIC, then the kernel will still run with no slowdown at all. 1074 1075config X86_LOCAL_APIC 1076 def_bool y 1077 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1078 select IRQ_DOMAIN_HIERARCHY 1079 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1080 1081config X86_IO_APIC 1082 def_bool y 1083 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1084 1085config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1086 bool "Reroute for broken boot IRQs" 1087 depends on X86_IO_APIC 1088 ---help--- 1089 This option enables a workaround that fixes a source of 1090 spurious interrupts. This is recommended when threaded 1091 interrupt handling is used on systems where the generation of 1092 superfluous "boot interrupts" cannot be disabled. 1093 1094 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1095 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1096 kernel does during interrupt handling). On chipsets where this 1097 boot IRQ generation cannot be disabled, this workaround keeps 1098 the original IRQ line masked so that only the equivalent "boot 1099 IRQ" is delivered to the CPUs. The workaround also tells the 1100 kernel to set up the IRQ handler on the boot IRQ line. In this 1101 way only one interrupt is delivered to the kernel. Otherwise 1102 the spurious second interrupt may cause the kernel to bring 1103 down (vital) interrupt lines. 1104 1105 Only affects "broken" chipsets. Interrupt sharing may be 1106 increased on these systems. 1107 1108config X86_MCE 1109 bool "Machine Check / overheating reporting" 1110 select GENERIC_ALLOCATOR 1111 default y 1112 ---help--- 1113 Machine Check support allows the processor to notify the 1114 kernel if it detects a problem (e.g. overheating, data corruption). 1115 The action the kernel takes depends on the severity of the problem, 1116 ranging from warning messages to halting the machine. 1117 1118config X86_MCELOG_LEGACY 1119 bool "Support for deprecated /dev/mcelog character device" 1120 depends on X86_MCE 1121 ---help--- 1122 Enable support for /dev/mcelog which is needed by the old mcelog 1123 userspace logging daemon. Consider switching to the new generation 1124 rasdaemon solution. 1125 1126config X86_MCE_INTEL 1127 def_bool y 1128 prompt "Intel MCE features" 1129 depends on X86_MCE && X86_LOCAL_APIC 1130 ---help--- 1131 Additional support for intel specific MCE features such as 1132 the thermal monitor. 1133 1134config X86_MCE_AMD 1135 def_bool y 1136 prompt "AMD MCE features" 1137 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1138 ---help--- 1139 Additional support for AMD specific MCE features such as 1140 the DRAM Error Threshold. 1141 1142config X86_ANCIENT_MCE 1143 bool "Support for old Pentium 5 / WinChip machine checks" 1144 depends on X86_32 && X86_MCE 1145 ---help--- 1146 Include support for machine check handling on old Pentium 5 or WinChip 1147 systems. These typically need to be enabled explicitly on the command 1148 line. 1149 1150config X86_MCE_THRESHOLD 1151 depends on X86_MCE_AMD || X86_MCE_INTEL 1152 def_bool y 1153 1154config X86_MCE_INJECT 1155 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1156 tristate "Machine check injector support" 1157 ---help--- 1158 Provide support for injecting machine checks for testing purposes. 1159 If you don't know what a machine check is and you don't do kernel 1160 QA it is safe to say n. 1161 1162config X86_THERMAL_VECTOR 1163 def_bool y 1164 depends on X86_MCE_INTEL 1165 1166source "arch/x86/events/Kconfig" 1167 1168config X86_LEGACY_VM86 1169 bool "Legacy VM86 support" 1170 default n 1171 depends on X86_32 1172 ---help--- 1173 This option allows user programs to put the CPU into V8086 1174 mode, which is an 80286-era approximation of 16-bit real mode. 1175 1176 Some very old versions of X and/or vbetool require this option 1177 for user mode setting. Similarly, DOSEMU will use it if 1178 available to accelerate real mode DOS programs. However, any 1179 recent version of DOSEMU, X, or vbetool should be fully 1180 functional even without kernel VM86 support, as they will all 1181 fall back to software emulation. Nevertheless, if you are using 1182 a 16-bit DOS program where 16-bit performance matters, vm86 1183 mode might be faster than emulation and you might want to 1184 enable this option. 1185 1186 Note that any app that works on a 64-bit kernel is unlikely to 1187 need this option, as 64-bit kernels don't, and can't, support 1188 V8086 mode. This option is also unrelated to 16-bit protected 1189 mode and is not needed to run most 16-bit programs under Wine. 1190 1191 Enabling this option increases the complexity of the kernel 1192 and slows down exception handling a tiny bit. 1193 1194 If unsure, say N here. 1195 1196config VM86 1197 bool 1198 default X86_LEGACY_VM86 1199 1200config X86_16BIT 1201 bool "Enable support for 16-bit segments" if EXPERT 1202 default y 1203 depends on MODIFY_LDT_SYSCALL 1204 ---help--- 1205 This option is required by programs like Wine to run 16-bit 1206 protected mode legacy code on x86 processors. Disabling 1207 this option saves about 300 bytes on i386, or around 6K text 1208 plus 16K runtime memory on x86-64, 1209 1210config X86_ESPFIX32 1211 def_bool y 1212 depends on X86_16BIT && X86_32 1213 1214config X86_ESPFIX64 1215 def_bool y 1216 depends on X86_16BIT && X86_64 1217 1218config X86_VSYSCALL_EMULATION 1219 bool "Enable vsyscall emulation" if EXPERT 1220 default y 1221 depends on X86_64 1222 ---help--- 1223 This enables emulation of the legacy vsyscall page. Disabling 1224 it is roughly equivalent to booting with vsyscall=none, except 1225 that it will also disable the helpful warning if a program 1226 tries to use a vsyscall. With this option set to N, offending 1227 programs will just segfault, citing addresses of the form 1228 0xffffffffff600?00. 1229 1230 This option is required by many programs built before 2013, and 1231 care should be used even with newer programs if set to N. 1232 1233 Disabling this option saves about 7K of kernel size and 1234 possibly 4K of additional runtime pagetable memory. 1235 1236config TOSHIBA 1237 tristate "Toshiba Laptop support" 1238 depends on X86_32 1239 ---help--- 1240 This adds a driver to safely access the System Management Mode of 1241 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1242 not work on models with a Phoenix BIOS. The System Management Mode 1243 is used to set the BIOS and power saving options on Toshiba portables. 1244 1245 For information on utilities to make use of this driver see the 1246 Toshiba Linux utilities web site at: 1247 <http://www.buzzard.org.uk/toshiba/>. 1248 1249 Say Y if you intend to run this kernel on a Toshiba portable. 1250 Say N otherwise. 1251 1252config I8K 1253 tristate "Dell i8k legacy laptop support" 1254 select HWMON 1255 select SENSORS_DELL_SMM 1256 ---help--- 1257 This option enables legacy /proc/i8k userspace interface in hwmon 1258 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1259 temperature and allows controlling fan speeds of Dell laptops via 1260 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1261 it reports also power and hotkey status. For fan speed control is 1262 needed userspace package i8kutils. 1263 1264 Say Y if you intend to run this kernel on old Dell laptops or want to 1265 use userspace package i8kutils. 1266 Say N otherwise. 1267 1268config X86_REBOOTFIXUPS 1269 bool "Enable X86 board specific fixups for reboot" 1270 depends on X86_32 1271 ---help--- 1272 This enables chipset and/or board specific fixups to be done 1273 in order to get reboot to work correctly. This is only needed on 1274 some combinations of hardware and BIOS. The symptom, for which 1275 this config is intended, is when reboot ends with a stalled/hung 1276 system. 1277 1278 Currently, the only fixup is for the Geode machines using 1279 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1280 1281 Say Y if you want to enable the fixup. Currently, it's safe to 1282 enable this option even if you don't need it. 1283 Say N otherwise. 1284 1285config MICROCODE 1286 bool "CPU microcode loading support" 1287 default y 1288 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1289 select FW_LOADER 1290 ---help--- 1291 If you say Y here, you will be able to update the microcode on 1292 Intel and AMD processors. The Intel support is for the IA32 family, 1293 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1294 AMD support is for families 0x10 and later. You will obviously need 1295 the actual microcode binary data itself which is not shipped with 1296 the Linux kernel. 1297 1298 The preferred method to load microcode from a detached initrd is described 1299 in Documentation/x86/microcode.txt. For that you need to enable 1300 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1301 initrd for microcode blobs. 1302 1303 In addition, you can build the microcode into the kernel. For that you 1304 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1305 config option. 1306 1307config MICROCODE_INTEL 1308 bool "Intel microcode loading support" 1309 depends on MICROCODE 1310 default MICROCODE 1311 select FW_LOADER 1312 ---help--- 1313 This options enables microcode patch loading support for Intel 1314 processors. 1315 1316 For the current Intel microcode data package go to 1317 <https://downloadcenter.intel.com> and search for 1318 'Linux Processor Microcode Data File'. 1319 1320config MICROCODE_AMD 1321 bool "AMD microcode loading support" 1322 depends on MICROCODE 1323 select FW_LOADER 1324 ---help--- 1325 If you select this option, microcode patch loading support for AMD 1326 processors will be enabled. 1327 1328config MICROCODE_OLD_INTERFACE 1329 def_bool y 1330 depends on MICROCODE 1331 1332config X86_MSR 1333 tristate "/dev/cpu/*/msr - Model-specific register support" 1334 ---help--- 1335 This device gives privileged processes access to the x86 1336 Model-Specific Registers (MSRs). It is a character device with 1337 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1338 MSR accesses are directed to a specific CPU on multi-processor 1339 systems. 1340 1341config X86_CPUID 1342 tristate "/dev/cpu/*/cpuid - CPU information support" 1343 ---help--- 1344 This device gives processes access to the x86 CPUID instruction to 1345 be executed on a specific processor. It is a character device 1346 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1347 /dev/cpu/31/cpuid. 1348 1349choice 1350 prompt "High Memory Support" 1351 default HIGHMEM4G 1352 depends on X86_32 1353 1354config NOHIGHMEM 1355 bool "off" 1356 ---help--- 1357 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1358 However, the address space of 32-bit x86 processors is only 4 1359 Gigabytes large. That means that, if you have a large amount of 1360 physical memory, not all of it can be "permanently mapped" by the 1361 kernel. The physical memory that's not permanently mapped is called 1362 "high memory". 1363 1364 If you are compiling a kernel which will never run on a machine with 1365 more than 1 Gigabyte total physical RAM, answer "off" here (default 1366 choice and suitable for most users). This will result in a "3GB/1GB" 1367 split: 3GB are mapped so that each process sees a 3GB virtual memory 1368 space and the remaining part of the 4GB virtual memory space is used 1369 by the kernel to permanently map as much physical memory as 1370 possible. 1371 1372 If the machine has between 1 and 4 Gigabytes physical RAM, then 1373 answer "4GB" here. 1374 1375 If more than 4 Gigabytes is used then answer "64GB" here. This 1376 selection turns Intel PAE (Physical Address Extension) mode on. 1377 PAE implements 3-level paging on IA32 processors. PAE is fully 1378 supported by Linux, PAE mode is implemented on all recent Intel 1379 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1380 then the kernel will not boot on CPUs that don't support PAE! 1381 1382 The actual amount of total physical memory will either be 1383 auto detected or can be forced by using a kernel command line option 1384 such as "mem=256M". (Try "man bootparam" or see the documentation of 1385 your boot loader (lilo or loadlin) about how to pass options to the 1386 kernel at boot time.) 1387 1388 If unsure, say "off". 1389 1390config HIGHMEM4G 1391 bool "4GB" 1392 ---help--- 1393 Select this if you have a 32-bit processor and between 1 and 4 1394 gigabytes of physical RAM. 1395 1396config HIGHMEM64G 1397 bool "64GB" 1398 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1399 select X86_PAE 1400 ---help--- 1401 Select this if you have a 32-bit processor and more than 4 1402 gigabytes of physical RAM. 1403 1404endchoice 1405 1406choice 1407 prompt "Memory split" if EXPERT 1408 default VMSPLIT_3G 1409 depends on X86_32 1410 ---help--- 1411 Select the desired split between kernel and user memory. 1412 1413 If the address range available to the kernel is less than the 1414 physical memory installed, the remaining memory will be available 1415 as "high memory". Accessing high memory is a little more costly 1416 than low memory, as it needs to be mapped into the kernel first. 1417 Note that increasing the kernel address space limits the range 1418 available to user programs, making the address space there 1419 tighter. Selecting anything other than the default 3G/1G split 1420 will also likely make your kernel incompatible with binary-only 1421 kernel modules. 1422 1423 If you are not absolutely sure what you are doing, leave this 1424 option alone! 1425 1426 config VMSPLIT_3G 1427 bool "3G/1G user/kernel split" 1428 config VMSPLIT_3G_OPT 1429 depends on !X86_PAE 1430 bool "3G/1G user/kernel split (for full 1G low memory)" 1431 config VMSPLIT_2G 1432 bool "2G/2G user/kernel split" 1433 config VMSPLIT_2G_OPT 1434 depends on !X86_PAE 1435 bool "2G/2G user/kernel split (for full 2G low memory)" 1436 config VMSPLIT_1G 1437 bool "1G/3G user/kernel split" 1438endchoice 1439 1440config PAGE_OFFSET 1441 hex 1442 default 0xB0000000 if VMSPLIT_3G_OPT 1443 default 0x80000000 if VMSPLIT_2G 1444 default 0x78000000 if VMSPLIT_2G_OPT 1445 default 0x40000000 if VMSPLIT_1G 1446 default 0xC0000000 1447 depends on X86_32 1448 1449config HIGHMEM 1450 def_bool y 1451 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1452 1453config X86_PAE 1454 bool "PAE (Physical Address Extension) Support" 1455 depends on X86_32 && !HIGHMEM4G 1456 select PHYS_ADDR_T_64BIT 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 X86_DIRECT_GBPAGES 1485 def_bool y 1486 depends on X86_64 && !DEBUG_PAGEALLOC 1487 ---help--- 1488 Certain kernel features effectively disable kernel 1489 linear 1 GB mappings (even if the CPU otherwise 1490 supports them), so don't confuse the user by printing 1491 that we have them enabled. 1492 1493config ARCH_HAS_MEM_ENCRYPT 1494 def_bool y 1495 1496config AMD_MEM_ENCRYPT 1497 bool "AMD Secure Memory Encryption (SME) support" 1498 depends on X86_64 && CPU_SUP_AMD 1499 select DYNAMIC_PHYSICAL_MASK 1500 ---help--- 1501 Say yes to enable support for the encryption of system memory. 1502 This requires an AMD processor that supports Secure Memory 1503 Encryption (SME). 1504 1505config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1506 bool "Activate AMD Secure Memory Encryption (SME) by default" 1507 default y 1508 depends on AMD_MEM_ENCRYPT 1509 ---help--- 1510 Say yes to have system memory encrypted by default if running on 1511 an AMD processor that supports Secure Memory Encryption (SME). 1512 1513 If set to Y, then the encryption of system memory can be 1514 deactivated with the mem_encrypt=off command line option. 1515 1516 If set to N, then the encryption of system memory can be 1517 activated with the mem_encrypt=on command line option. 1518 1519config ARCH_USE_MEMREMAP_PROT 1520 def_bool y 1521 depends on AMD_MEM_ENCRYPT 1522 1523# Common NUMA Features 1524config NUMA 1525 bool "Numa Memory Allocation and Scheduler Support" 1526 depends on SMP 1527 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1528 default y if X86_BIGSMP 1529 ---help--- 1530 Enable NUMA (Non Uniform Memory Access) support. 1531 1532 The kernel will try to allocate memory used by a CPU on the 1533 local memory controller of the CPU and add some more 1534 NUMA awareness to the kernel. 1535 1536 For 64-bit this is recommended if the system is Intel Core i7 1537 (or later), AMD Opteron, or EM64T NUMA. 1538 1539 For 32-bit this is only needed if you boot a 32-bit 1540 kernel on a 64-bit NUMA platform. 1541 1542 Otherwise, you should say N. 1543 1544config AMD_NUMA 1545 def_bool y 1546 prompt "Old style AMD Opteron NUMA detection" 1547 depends on X86_64 && NUMA && PCI 1548 ---help--- 1549 Enable AMD NUMA node topology detection. You should say Y here if 1550 you have a multi processor AMD system. This uses an old method to 1551 read the NUMA configuration directly from the builtin Northbridge 1552 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1553 which also takes priority if both are compiled in. 1554 1555config X86_64_ACPI_NUMA 1556 def_bool y 1557 prompt "ACPI NUMA detection" 1558 depends on X86_64 && NUMA && ACPI && PCI 1559 select ACPI_NUMA 1560 ---help--- 1561 Enable ACPI SRAT based node topology detection. 1562 1563# Some NUMA nodes have memory ranges that span 1564# other nodes. Even though a pfn is valid and 1565# between a node's start and end pfns, it may not 1566# reside on that node. See memmap_init_zone() 1567# for details. 1568config NODES_SPAN_OTHER_NODES 1569 def_bool y 1570 depends on X86_64_ACPI_NUMA 1571 1572config NUMA_EMU 1573 bool "NUMA emulation" 1574 depends on NUMA 1575 ---help--- 1576 Enable NUMA emulation. A flat machine will be split 1577 into virtual nodes when booted with "numa=fake=N", where N is the 1578 number of nodes. This is only useful for debugging. 1579 1580config NODES_SHIFT 1581 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1582 range 1 10 1583 default "10" if MAXSMP 1584 default "6" if X86_64 1585 default "3" 1586 depends on NEED_MULTIPLE_NODES 1587 ---help--- 1588 Specify the maximum number of NUMA Nodes available on the target 1589 system. Increases memory reserved to accommodate various tables. 1590 1591config ARCH_HAVE_MEMORY_PRESENT 1592 def_bool y 1593 depends on X86_32 && DISCONTIGMEM 1594 1595config ARCH_FLATMEM_ENABLE 1596 def_bool y 1597 depends on X86_32 && !NUMA 1598 1599config ARCH_DISCONTIGMEM_ENABLE 1600 def_bool y 1601 depends on NUMA && X86_32 1602 1603config ARCH_DISCONTIGMEM_DEFAULT 1604 def_bool y 1605 depends on NUMA && X86_32 1606 1607config ARCH_SPARSEMEM_ENABLE 1608 def_bool y 1609 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1610 select SPARSEMEM_STATIC if X86_32 1611 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1612 1613config ARCH_SPARSEMEM_DEFAULT 1614 def_bool y 1615 depends on X86_64 1616 1617config ARCH_SELECT_MEMORY_MODEL 1618 def_bool y 1619 depends on ARCH_SPARSEMEM_ENABLE 1620 1621config ARCH_MEMORY_PROBE 1622 bool "Enable sysfs memory/probe interface" 1623 depends on X86_64 && MEMORY_HOTPLUG 1624 help 1625 This option enables a sysfs memory/probe interface for testing. 1626 See Documentation/memory-hotplug.txt for more information. 1627 If you are unsure how to answer this question, answer N. 1628 1629config ARCH_PROC_KCORE_TEXT 1630 def_bool y 1631 depends on X86_64 && PROC_KCORE 1632 1633config ILLEGAL_POINTER_VALUE 1634 hex 1635 default 0 if X86_32 1636 default 0xdead000000000000 if X86_64 1637 1638config X86_PMEM_LEGACY_DEVICE 1639 bool 1640 1641config X86_PMEM_LEGACY 1642 tristate "Support non-standard NVDIMMs and ADR protected memory" 1643 depends on PHYS_ADDR_T_64BIT 1644 depends on BLK_DEV 1645 select X86_PMEM_LEGACY_DEVICE 1646 select LIBNVDIMM 1647 help 1648 Treat memory marked using the non-standard e820 type of 12 as used 1649 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1650 The kernel will offer these regions to the 'pmem' driver so 1651 they can be used for persistent storage. 1652 1653 Say Y if unsure. 1654 1655config HIGHPTE 1656 bool "Allocate 3rd-level pagetables from highmem" 1657 depends on HIGHMEM 1658 ---help--- 1659 The VM uses one page table entry for each page of physical memory. 1660 For systems with a lot of RAM, this can be wasteful of precious 1661 low memory. Setting this option will put user-space page table 1662 entries in high memory. 1663 1664config X86_CHECK_BIOS_CORRUPTION 1665 bool "Check for low memory corruption" 1666 ---help--- 1667 Periodically check for memory corruption in low memory, which 1668 is suspected to be caused by BIOS. Even when enabled in the 1669 configuration, it is disabled at runtime. Enable it by 1670 setting "memory_corruption_check=1" on the kernel command 1671 line. By default it scans the low 64k of memory every 60 1672 seconds; see the memory_corruption_check_size and 1673 memory_corruption_check_period parameters in 1674 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1675 1676 When enabled with the default parameters, this option has 1677 almost no overhead, as it reserves a relatively small amount 1678 of memory and scans it infrequently. It both detects corruption 1679 and prevents it from affecting the running system. 1680 1681 It is, however, intended as a diagnostic tool; if repeatable 1682 BIOS-originated corruption always affects the same memory, 1683 you can use memmap= to prevent the kernel from using that 1684 memory. 1685 1686config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1687 bool "Set the default setting of memory_corruption_check" 1688 depends on X86_CHECK_BIOS_CORRUPTION 1689 default y 1690 ---help--- 1691 Set whether the default state of memory_corruption_check is 1692 on or off. 1693 1694config X86_RESERVE_LOW 1695 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1696 default 64 1697 range 4 640 1698 ---help--- 1699 Specify the amount of low memory to reserve for the BIOS. 1700 1701 The first page contains BIOS data structures that the kernel 1702 must not use, so that page must always be reserved. 1703 1704 By default we reserve the first 64K of physical RAM, as a 1705 number of BIOSes are known to corrupt that memory range 1706 during events such as suspend/resume or monitor cable 1707 insertion, so it must not be used by the kernel. 1708 1709 You can set this to 4 if you are absolutely sure that you 1710 trust the BIOS to get all its memory reservations and usages 1711 right. If you know your BIOS have problems beyond the 1712 default 64K area, you can set this to 640 to avoid using the 1713 entire low memory range. 1714 1715 If you have doubts about the BIOS (e.g. suspend/resume does 1716 not work or there's kernel crashes after certain hardware 1717 hotplug events) then you might want to enable 1718 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1719 typical corruption patterns. 1720 1721 Leave this to the default value of 64 if you are unsure. 1722 1723config MATH_EMULATION 1724 bool 1725 depends on MODIFY_LDT_SYSCALL 1726 prompt "Math emulation" if X86_32 1727 ---help--- 1728 Linux can emulate a math coprocessor (used for floating point 1729 operations) if you don't have one. 486DX and Pentium processors have 1730 a math coprocessor built in, 486SX and 386 do not, unless you added 1731 a 487DX or 387, respectively. (The messages during boot time can 1732 give you some hints here ["man dmesg"].) Everyone needs either a 1733 coprocessor or this emulation. 1734 1735 If you don't have a math coprocessor, you need to say Y here; if you 1736 say Y here even though you have a coprocessor, the coprocessor will 1737 be used nevertheless. (This behavior can be changed with the kernel 1738 command line option "no387", which comes handy if your coprocessor 1739 is broken. Try "man bootparam" or see the documentation of your boot 1740 loader (lilo or loadlin) about how to pass options to the kernel at 1741 boot time.) This means that it is a good idea to say Y here if you 1742 intend to use this kernel on different machines. 1743 1744 More information about the internals of the Linux math coprocessor 1745 emulation can be found in <file:arch/x86/math-emu/README>. 1746 1747 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1748 kernel, it won't hurt. 1749 1750config MTRR 1751 def_bool y 1752 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1753 ---help--- 1754 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1755 the Memory Type Range Registers (MTRRs) may be used to control 1756 processor access to memory ranges. This is most useful if you have 1757 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1758 allows bus write transfers to be combined into a larger transfer 1759 before bursting over the PCI/AGP bus. This can increase performance 1760 of image write operations 2.5 times or more. Saying Y here creates a 1761 /proc/mtrr file which may be used to manipulate your processor's 1762 MTRRs. Typically the X server should use this. 1763 1764 This code has a reasonably generic interface so that similar 1765 control registers on other processors can be easily supported 1766 as well: 1767 1768 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1769 Registers (ARRs) which provide a similar functionality to MTRRs. For 1770 these, the ARRs are used to emulate the MTRRs. 1771 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1772 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1773 write-combining. All of these processors are supported by this code 1774 and it makes sense to say Y here if you have one of them. 1775 1776 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1777 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1778 can lead to all sorts of problems, so it's good to say Y here. 1779 1780 You can safely say Y even if your machine doesn't have MTRRs, you'll 1781 just add about 9 KB to your kernel. 1782 1783 See <file:Documentation/x86/mtrr.txt> for more information. 1784 1785config MTRR_SANITIZER 1786 def_bool y 1787 prompt "MTRR cleanup support" 1788 depends on MTRR 1789 ---help--- 1790 Convert MTRR layout from continuous to discrete, so X drivers can 1791 add writeback entries. 1792 1793 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1794 The largest mtrr entry size for a continuous block can be set with 1795 mtrr_chunk_size. 1796 1797 If unsure, say Y. 1798 1799config MTRR_SANITIZER_ENABLE_DEFAULT 1800 int "MTRR cleanup enable value (0-1)" 1801 range 0 1 1802 default "0" 1803 depends on MTRR_SANITIZER 1804 ---help--- 1805 Enable mtrr cleanup default value 1806 1807config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1808 int "MTRR cleanup spare reg num (0-7)" 1809 range 0 7 1810 default "1" 1811 depends on MTRR_SANITIZER 1812 ---help--- 1813 mtrr cleanup spare entries default, it can be changed via 1814 mtrr_spare_reg_nr=N on the kernel command line. 1815 1816config X86_PAT 1817 def_bool y 1818 prompt "x86 PAT support" if EXPERT 1819 depends on MTRR 1820 ---help--- 1821 Use PAT attributes to setup page level cache control. 1822 1823 PATs are the modern equivalents of MTRRs and are much more 1824 flexible than MTRRs. 1825 1826 Say N here if you see bootup problems (boot crash, boot hang, 1827 spontaneous reboots) or a non-working video driver. 1828 1829 If unsure, say Y. 1830 1831config ARCH_USES_PG_UNCACHED 1832 def_bool y 1833 depends on X86_PAT 1834 1835config ARCH_RANDOM 1836 def_bool y 1837 prompt "x86 architectural random number generator" if EXPERT 1838 ---help--- 1839 Enable the x86 architectural RDRAND instruction 1840 (Intel Bull Mountain technology) to generate random numbers. 1841 If supported, this is a high bandwidth, cryptographically 1842 secure hardware random number generator. 1843 1844config X86_SMAP 1845 def_bool y 1846 prompt "Supervisor Mode Access Prevention" if EXPERT 1847 ---help--- 1848 Supervisor Mode Access Prevention (SMAP) is a security 1849 feature in newer Intel processors. There is a small 1850 performance cost if this enabled and turned on; there is 1851 also a small increase in the kernel size if this is enabled. 1852 1853 If unsure, say Y. 1854 1855config X86_INTEL_UMIP 1856 def_bool y 1857 depends on CPU_SUP_INTEL 1858 prompt "Intel User Mode Instruction Prevention" if EXPERT 1859 ---help--- 1860 The User Mode Instruction Prevention (UMIP) is a security 1861 feature in newer Intel processors. If enabled, a general 1862 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1863 or STR instructions are executed in user mode. These instructions 1864 unnecessarily expose information about the hardware state. 1865 1866 The vast majority of applications do not use these instructions. 1867 For the very few that do, software emulation is provided in 1868 specific cases in protected and virtual-8086 modes. Emulated 1869 results are dummy. 1870 1871config X86_INTEL_MPX 1872 prompt "Intel MPX (Memory Protection Extensions)" 1873 def_bool n 1874 # Note: only available in 64-bit mode due to VMA flags shortage 1875 depends on CPU_SUP_INTEL && X86_64 1876 select ARCH_USES_HIGH_VMA_FLAGS 1877 ---help--- 1878 MPX provides hardware features that can be used in 1879 conjunction with compiler-instrumented code to check 1880 memory references. It is designed to detect buffer 1881 overflow or underflow bugs. 1882 1883 This option enables running applications which are 1884 instrumented or otherwise use MPX. It does not use MPX 1885 itself inside the kernel or to protect the kernel 1886 against bad memory references. 1887 1888 Enabling this option will make the kernel larger: 1889 ~8k of kernel text and 36 bytes of data on a 64-bit 1890 defconfig. It adds a long to the 'mm_struct' which 1891 will increase the kernel memory overhead of each 1892 process and adds some branches to paths used during 1893 exec() and munmap(). 1894 1895 For details, see Documentation/x86/intel_mpx.txt 1896 1897 If unsure, say N. 1898 1899config X86_INTEL_MEMORY_PROTECTION_KEYS 1900 prompt "Intel Memory Protection Keys" 1901 def_bool y 1902 # Note: only available in 64-bit mode 1903 depends on CPU_SUP_INTEL && X86_64 1904 select ARCH_USES_HIGH_VMA_FLAGS 1905 select ARCH_HAS_PKEYS 1906 ---help--- 1907 Memory Protection Keys provides a mechanism for enforcing 1908 page-based protections, but without requiring modification of the 1909 page tables when an application changes protection domains. 1910 1911 For details, see Documentation/x86/protection-keys.txt 1912 1913 If unsure, say y. 1914 1915config EFI 1916 bool "EFI runtime service support" 1917 depends on ACPI 1918 select UCS2_STRING 1919 select EFI_RUNTIME_WRAPPERS 1920 ---help--- 1921 This enables the kernel to use EFI runtime services that are 1922 available (such as the EFI variable services). 1923 1924 This option is only useful on systems that have EFI firmware. 1925 In addition, you should use the latest ELILO loader available 1926 at <http://elilo.sourceforge.net> in order to take advantage 1927 of EFI runtime services. However, even with this option, the 1928 resultant kernel should continue to boot on existing non-EFI 1929 platforms. 1930 1931config EFI_STUB 1932 bool "EFI stub support" 1933 depends on EFI && !X86_USE_3DNOW 1934 select RELOCATABLE 1935 ---help--- 1936 This kernel feature allows a bzImage to be loaded directly 1937 by EFI firmware without the use of a bootloader. 1938 1939 See Documentation/efi-stub.txt for more information. 1940 1941config EFI_MIXED 1942 bool "EFI mixed-mode support" 1943 depends on EFI_STUB && X86_64 1944 ---help--- 1945 Enabling this feature allows a 64-bit kernel to be booted 1946 on a 32-bit firmware, provided that your CPU supports 64-bit 1947 mode. 1948 1949 Note that it is not possible to boot a mixed-mode enabled 1950 kernel via the EFI boot stub - a bootloader that supports 1951 the EFI handover protocol must be used. 1952 1953 If unsure, say N. 1954 1955config SECCOMP 1956 def_bool y 1957 prompt "Enable seccomp to safely compute untrusted bytecode" 1958 ---help--- 1959 This kernel feature is useful for number crunching applications 1960 that may need to compute untrusted bytecode during their 1961 execution. By using pipes or other transports made available to 1962 the process as file descriptors supporting the read/write 1963 syscalls, it's possible to isolate those applications in 1964 their own address space using seccomp. Once seccomp is 1965 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1966 and the task is only allowed to execute a few safe syscalls 1967 defined by each seccomp mode. 1968 1969 If unsure, say Y. Only embedded should say N here. 1970 1971source kernel/Kconfig.hz 1972 1973config KEXEC 1974 bool "kexec system call" 1975 select KEXEC_CORE 1976 ---help--- 1977 kexec is a system call that implements the ability to shutdown your 1978 current kernel, and to start another kernel. It is like a reboot 1979 but it is independent of the system firmware. And like a reboot 1980 you can start any kernel with it, not just Linux. 1981 1982 The name comes from the similarity to the exec system call. 1983 1984 It is an ongoing process to be certain the hardware in a machine 1985 is properly shutdown, so do not be surprised if this code does not 1986 initially work for you. As of this writing the exact hardware 1987 interface is strongly in flux, so no good recommendation can be 1988 made. 1989 1990config KEXEC_FILE 1991 bool "kexec file based system call" 1992 select KEXEC_CORE 1993 select BUILD_BIN2C 1994 depends on X86_64 1995 depends on CRYPTO=y 1996 depends on CRYPTO_SHA256=y 1997 ---help--- 1998 This is new version of kexec system call. This system call is 1999 file based and takes file descriptors as system call argument 2000 for kernel and initramfs as opposed to list of segments as 2001 accepted by previous system call. 2002 2003config ARCH_HAS_KEXEC_PURGATORY 2004 def_bool KEXEC_FILE 2005 2006config KEXEC_VERIFY_SIG 2007 bool "Verify kernel signature during kexec_file_load() syscall" 2008 depends on KEXEC_FILE 2009 ---help--- 2010 This option makes kernel signature verification mandatory for 2011 the kexec_file_load() syscall. 2012 2013 In addition to that option, you need to enable signature 2014 verification for the corresponding kernel image type being 2015 loaded in order for this to work. 2016 2017config KEXEC_BZIMAGE_VERIFY_SIG 2018 bool "Enable bzImage signature verification support" 2019 depends on KEXEC_VERIFY_SIG 2020 depends on SIGNED_PE_FILE_VERIFICATION 2021 select SYSTEM_TRUSTED_KEYRING 2022 ---help--- 2023 Enable bzImage signature verification support. 2024 2025config CRASH_DUMP 2026 bool "kernel crash dumps" 2027 depends on X86_64 || (X86_32 && HIGHMEM) 2028 ---help--- 2029 Generate crash dump after being started by kexec. 2030 This should be normally only set in special crash dump kernels 2031 which are loaded in the main kernel with kexec-tools into 2032 a specially reserved region and then later executed after 2033 a crash by kdump/kexec. The crash dump kernel must be compiled 2034 to a memory address not used by the main kernel or BIOS using 2035 PHYSICAL_START, or it must be built as a relocatable image 2036 (CONFIG_RELOCATABLE=y). 2037 For more details see Documentation/kdump/kdump.txt 2038 2039config KEXEC_JUMP 2040 bool "kexec jump" 2041 depends on KEXEC && HIBERNATION 2042 ---help--- 2043 Jump between original kernel and kexeced kernel and invoke 2044 code in physical address mode via KEXEC 2045 2046config PHYSICAL_START 2047 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2048 default "0x1000000" 2049 ---help--- 2050 This gives the physical address where the kernel is loaded. 2051 2052 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2053 bzImage will decompress itself to above physical address and 2054 run from there. Otherwise, bzImage will run from the address where 2055 it has been loaded by the boot loader and will ignore above physical 2056 address. 2057 2058 In normal kdump cases one does not have to set/change this option 2059 as now bzImage can be compiled as a completely relocatable image 2060 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2061 address. This option is mainly useful for the folks who don't want 2062 to use a bzImage for capturing the crash dump and want to use a 2063 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2064 to be specifically compiled to run from a specific memory area 2065 (normally a reserved region) and this option comes handy. 2066 2067 So if you are using bzImage for capturing the crash dump, 2068 leave the value here unchanged to 0x1000000 and set 2069 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2070 for capturing the crash dump change this value to start of 2071 the reserved region. In other words, it can be set based on 2072 the "X" value as specified in the "crashkernel=YM@XM" 2073 command line boot parameter passed to the panic-ed 2074 kernel. Please take a look at Documentation/kdump/kdump.txt 2075 for more details about crash dumps. 2076 2077 Usage of bzImage for capturing the crash dump is recommended as 2078 one does not have to build two kernels. Same kernel can be used 2079 as production kernel and capture kernel. Above option should have 2080 gone away after relocatable bzImage support is introduced. But it 2081 is present because there are users out there who continue to use 2082 vmlinux for dump capture. This option should go away down the 2083 line. 2084 2085 Don't change this unless you know what you are doing. 2086 2087config RELOCATABLE 2088 bool "Build a relocatable kernel" 2089 default y 2090 ---help--- 2091 This builds a kernel image that retains relocation information 2092 so it can be loaded someplace besides the default 1MB. 2093 The relocations tend to make the kernel binary about 10% larger, 2094 but are discarded at runtime. 2095 2096 One use is for the kexec on panic case where the recovery kernel 2097 must live at a different physical address than the primary 2098 kernel. 2099 2100 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2101 it has been loaded at and the compile time physical address 2102 (CONFIG_PHYSICAL_START) is used as the minimum location. 2103 2104config RANDOMIZE_BASE 2105 bool "Randomize the address of the kernel image (KASLR)" 2106 depends on RELOCATABLE 2107 default y 2108 ---help--- 2109 In support of Kernel Address Space Layout Randomization (KASLR), 2110 this randomizes the physical address at which the kernel image 2111 is decompressed and the virtual address where the kernel 2112 image is mapped, as a security feature that deters exploit 2113 attempts relying on knowledge of the location of kernel 2114 code internals. 2115 2116 On 64-bit, the kernel physical and virtual addresses are 2117 randomized separately. The physical address will be anywhere 2118 between 16MB and the top of physical memory (up to 64TB). The 2119 virtual address will be randomized from 16MB up to 1GB (9 bits 2120 of entropy). Note that this also reduces the memory space 2121 available to kernel modules from 1.5GB to 1GB. 2122 2123 On 32-bit, the kernel physical and virtual addresses are 2124 randomized together. They will be randomized from 16MB up to 2125 512MB (8 bits of entropy). 2126 2127 Entropy is generated using the RDRAND instruction if it is 2128 supported. If RDTSC is supported, its value is mixed into 2129 the entropy pool as well. If neither RDRAND nor RDTSC are 2130 supported, then entropy is read from the i8254 timer. The 2131 usable entropy is limited by the kernel being built using 2132 2GB addressing, and that PHYSICAL_ALIGN must be at a 2133 minimum of 2MB. As a result, only 10 bits of entropy are 2134 theoretically possible, but the implementations are further 2135 limited due to memory layouts. 2136 2137 If unsure, say Y. 2138 2139# Relocation on x86 needs some additional build support 2140config X86_NEED_RELOCS 2141 def_bool y 2142 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2143 2144config PHYSICAL_ALIGN 2145 hex "Alignment value to which kernel should be aligned" 2146 default "0x200000" 2147 range 0x2000 0x1000000 if X86_32 2148 range 0x200000 0x1000000 if X86_64 2149 ---help--- 2150 This value puts the alignment restrictions on physical address 2151 where kernel is loaded and run from. Kernel is compiled for an 2152 address which meets above alignment restriction. 2153 2154 If bootloader loads the kernel at a non-aligned address and 2155 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2156 address aligned to above value and run from there. 2157 2158 If bootloader loads the kernel at a non-aligned address and 2159 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2160 load address and decompress itself to the address it has been 2161 compiled for and run from there. The address for which kernel is 2162 compiled already meets above alignment restrictions. Hence the 2163 end result is that kernel runs from a physical address meeting 2164 above alignment restrictions. 2165 2166 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2167 this value must be a multiple of 0x200000. 2168 2169 Don't change this unless you know what you are doing. 2170 2171config DYNAMIC_MEMORY_LAYOUT 2172 bool 2173 ---help--- 2174 This option makes base addresses of vmalloc and vmemmap as well as 2175 __PAGE_OFFSET movable during boot. 2176 2177config RANDOMIZE_MEMORY 2178 bool "Randomize the kernel memory sections" 2179 depends on X86_64 2180 depends on RANDOMIZE_BASE 2181 select DYNAMIC_MEMORY_LAYOUT 2182 default RANDOMIZE_BASE 2183 ---help--- 2184 Randomizes the base virtual address of kernel memory sections 2185 (physical memory mapping, vmalloc & vmemmap). This security feature 2186 makes exploits relying on predictable memory locations less reliable. 2187 2188 The order of allocations remains unchanged. Entropy is generated in 2189 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2190 configuration have in average 30,000 different possible virtual 2191 addresses for each memory section. 2192 2193 If unsure, say Y. 2194 2195config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2196 hex "Physical memory mapping padding" if EXPERT 2197 depends on RANDOMIZE_MEMORY 2198 default "0xa" if MEMORY_HOTPLUG 2199 default "0x0" 2200 range 0x1 0x40 if MEMORY_HOTPLUG 2201 range 0x0 0x40 2202 ---help--- 2203 Define the padding in terabytes added to the existing physical 2204 memory size during kernel memory randomization. It is useful 2205 for memory hotplug support but reduces the entropy available for 2206 address randomization. 2207 2208 If unsure, leave at the default value. 2209 2210config HOTPLUG_CPU 2211 bool "Support for hot-pluggable CPUs" 2212 depends on SMP 2213 ---help--- 2214 Say Y here to allow turning CPUs off and on. CPUs can be 2215 controlled through /sys/devices/system/cpu. 2216 ( Note: power management support will enable this option 2217 automatically on SMP systems. ) 2218 Say N if you want to disable CPU hotplug. 2219 2220config BOOTPARAM_HOTPLUG_CPU0 2221 bool "Set default setting of cpu0_hotpluggable" 2222 default n 2223 depends on HOTPLUG_CPU 2224 ---help--- 2225 Set whether default state of cpu0_hotpluggable is on or off. 2226 2227 Say Y here to enable CPU0 hotplug by default. If this switch 2228 is turned on, there is no need to give cpu0_hotplug kernel 2229 parameter and the CPU0 hotplug feature is enabled by default. 2230 2231 Please note: there are two known CPU0 dependencies if you want 2232 to enable the CPU0 hotplug feature either by this switch or by 2233 cpu0_hotplug kernel parameter. 2234 2235 First, resume from hibernate or suspend always starts from CPU0. 2236 So hibernate and suspend are prevented if CPU0 is offline. 2237 2238 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2239 offline if any interrupt can not migrate out of CPU0. There may 2240 be other CPU0 dependencies. 2241 2242 Please make sure the dependencies are under your control before 2243 you enable this feature. 2244 2245 Say N if you don't want to enable CPU0 hotplug feature by default. 2246 You still can enable the CPU0 hotplug feature at boot by kernel 2247 parameter cpu0_hotplug. 2248 2249config DEBUG_HOTPLUG_CPU0 2250 def_bool n 2251 prompt "Debug CPU0 hotplug" 2252 depends on HOTPLUG_CPU 2253 ---help--- 2254 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2255 soon as possible and boots up userspace with CPU0 offlined. User 2256 can online CPU0 back after boot time. 2257 2258 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2259 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2260 compilation or giving cpu0_hotplug kernel parameter at boot. 2261 2262 If unsure, say N. 2263 2264config COMPAT_VDSO 2265 def_bool n 2266 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2267 depends on COMPAT_32 2268 ---help--- 2269 Certain buggy versions of glibc will crash if they are 2270 presented with a 32-bit vDSO that is not mapped at the address 2271 indicated in its segment table. 2272 2273 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2274 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2275 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2276 the only released version with the bug, but OpenSUSE 9 2277 contains a buggy "glibc 2.3.2". 2278 2279 The symptom of the bug is that everything crashes on startup, saying: 2280 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2281 2282 Saying Y here changes the default value of the vdso32 boot 2283 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2284 This works around the glibc bug but hurts performance. 2285 2286 If unsure, say N: if you are compiling your own kernel, you 2287 are unlikely to be using a buggy version of glibc. 2288 2289choice 2290 prompt "vsyscall table for legacy applications" 2291 depends on X86_64 2292 default LEGACY_VSYSCALL_EMULATE 2293 help 2294 Legacy user code that does not know how to find the vDSO expects 2295 to be able to issue three syscalls by calling fixed addresses in 2296 kernel space. Since this location is not randomized with ASLR, 2297 it can be used to assist security vulnerability exploitation. 2298 2299 This setting can be changed at boot time via the kernel command 2300 line parameter vsyscall=[emulate|none]. 2301 2302 On a system with recent enough glibc (2.14 or newer) and no 2303 static binaries, you can say None without a performance penalty 2304 to improve security. 2305 2306 If unsure, select "Emulate". 2307 2308 config LEGACY_VSYSCALL_EMULATE 2309 bool "Emulate" 2310 help 2311 The kernel traps and emulates calls into the fixed 2312 vsyscall address mapping. This makes the mapping 2313 non-executable, but it still contains known contents, 2314 which could be used in certain rare security vulnerability 2315 exploits. This configuration is recommended when userspace 2316 still uses the vsyscall area. 2317 2318 config LEGACY_VSYSCALL_NONE 2319 bool "None" 2320 help 2321 There will be no vsyscall mapping at all. This will 2322 eliminate any risk of ASLR bypass due to the vsyscall 2323 fixed address mapping. Attempts to use the vsyscalls 2324 will be reported to dmesg, so that either old or 2325 malicious userspace programs can be identified. 2326 2327endchoice 2328 2329config CMDLINE_BOOL 2330 bool "Built-in kernel command line" 2331 ---help--- 2332 Allow for specifying boot arguments to the kernel at 2333 build time. On some systems (e.g. embedded ones), it is 2334 necessary or convenient to provide some or all of the 2335 kernel boot arguments with the kernel itself (that is, 2336 to not rely on the boot loader to provide them.) 2337 2338 To compile command line arguments into the kernel, 2339 set this option to 'Y', then fill in the 2340 boot arguments in CONFIG_CMDLINE. 2341 2342 Systems with fully functional boot loaders (i.e. non-embedded) 2343 should leave this option set to 'N'. 2344 2345config CMDLINE 2346 string "Built-in kernel command string" 2347 depends on CMDLINE_BOOL 2348 default "" 2349 ---help--- 2350 Enter arguments here that should be compiled into the kernel 2351 image and used at boot time. If the boot loader provides a 2352 command line at boot time, it is appended to this string to 2353 form the full kernel command line, when the system boots. 2354 2355 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2356 change this behavior. 2357 2358 In most cases, the command line (whether built-in or provided 2359 by the boot loader) should specify the device for the root 2360 file system. 2361 2362config CMDLINE_OVERRIDE 2363 bool "Built-in command line overrides boot loader arguments" 2364 depends on CMDLINE_BOOL 2365 ---help--- 2366 Set this option to 'Y' to have the kernel ignore the boot loader 2367 command line, and use ONLY the built-in command line. 2368 2369 This is used to work around broken boot loaders. This should 2370 be set to 'N' under normal conditions. 2371 2372config MODIFY_LDT_SYSCALL 2373 bool "Enable the LDT (local descriptor table)" if EXPERT 2374 default y 2375 ---help--- 2376 Linux can allow user programs to install a per-process x86 2377 Local Descriptor Table (LDT) using the modify_ldt(2) system 2378 call. This is required to run 16-bit or segmented code such as 2379 DOSEMU or some Wine programs. It is also used by some very old 2380 threading libraries. 2381 2382 Enabling this feature adds a small amount of overhead to 2383 context switches and increases the low-level kernel attack 2384 surface. Disabling it removes the modify_ldt(2) system call. 2385 2386 Saying 'N' here may make sense for embedded or server kernels. 2387 2388source "kernel/livepatch/Kconfig" 2389 2390endmenu 2391 2392config ARCH_HAS_ADD_PAGES 2393 def_bool y 2394 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2395 2396config ARCH_ENABLE_MEMORY_HOTPLUG 2397 def_bool y 2398 depends on X86_64 || (X86_32 && HIGHMEM) 2399 2400config ARCH_ENABLE_MEMORY_HOTREMOVE 2401 def_bool y 2402 depends on MEMORY_HOTPLUG 2403 2404config USE_PERCPU_NUMA_NODE_ID 2405 def_bool y 2406 depends on NUMA 2407 2408config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2409 def_bool y 2410 depends on X86_64 || X86_PAE 2411 2412config ARCH_ENABLE_HUGEPAGE_MIGRATION 2413 def_bool y 2414 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2415 2416config ARCH_ENABLE_THP_MIGRATION 2417 def_bool y 2418 depends on X86_64 && TRANSPARENT_HUGEPAGE 2419 2420menu "Power management and ACPI options" 2421 2422config ARCH_HIBERNATION_HEADER 2423 def_bool y 2424 depends on X86_64 && HIBERNATION 2425 2426source "kernel/power/Kconfig" 2427 2428source "drivers/acpi/Kconfig" 2429 2430source "drivers/sfi/Kconfig" 2431 2432config X86_APM_BOOT 2433 def_bool y 2434 depends on APM 2435 2436menuconfig APM 2437 tristate "APM (Advanced Power Management) BIOS support" 2438 depends on X86_32 && PM_SLEEP 2439 ---help--- 2440 APM is a BIOS specification for saving power using several different 2441 techniques. This is mostly useful for battery powered laptops with 2442 APM compliant BIOSes. If you say Y here, the system time will be 2443 reset after a RESUME operation, the /proc/apm device will provide 2444 battery status information, and user-space programs will receive 2445 notification of APM "events" (e.g. battery status change). 2446 2447 If you select "Y" here, you can disable actual use of the APM 2448 BIOS by passing the "apm=off" option to the kernel at boot time. 2449 2450 Note that the APM support is almost completely disabled for 2451 machines with more than one CPU. 2452 2453 In order to use APM, you will need supporting software. For location 2454 and more information, read <file:Documentation/power/apm-acpi.txt> 2455 and the Battery Powered Linux mini-HOWTO, available from 2456 <http://www.tldp.org/docs.html#howto>. 2457 2458 This driver does not spin down disk drives (see the hdparm(8) 2459 manpage ("man 8 hdparm") for that), and it doesn't turn off 2460 VESA-compliant "green" monitors. 2461 2462 This driver does not support the TI 4000M TravelMate and the ACER 2463 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2464 desktop machines also don't have compliant BIOSes, and this driver 2465 may cause those machines to panic during the boot phase. 2466 2467 Generally, if you don't have a battery in your machine, there isn't 2468 much point in using this driver and you should say N. If you get 2469 random kernel OOPSes or reboots that don't seem to be related to 2470 anything, try disabling/enabling this option (or disabling/enabling 2471 APM in your BIOS). 2472 2473 Some other things you should try when experiencing seemingly random, 2474 "weird" problems: 2475 2476 1) make sure that you have enough swap space and that it is 2477 enabled. 2478 2) pass the "no-hlt" option to the kernel 2479 3) switch on floating point emulation in the kernel and pass 2480 the "no387" option to the kernel 2481 4) pass the "floppy=nodma" option to the kernel 2482 5) pass the "mem=4M" option to the kernel (thereby disabling 2483 all but the first 4 MB of RAM) 2484 6) make sure that the CPU is not over clocked. 2485 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2486 8) disable the cache from your BIOS settings 2487 9) install a fan for the video card or exchange video RAM 2488 10) install a better fan for the CPU 2489 11) exchange RAM chips 2490 12) exchange the motherboard. 2491 2492 To compile this driver as a module, choose M here: the 2493 module will be called apm. 2494 2495if APM 2496 2497config APM_IGNORE_USER_SUSPEND 2498 bool "Ignore USER SUSPEND" 2499 ---help--- 2500 This option will ignore USER SUSPEND requests. On machines with a 2501 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2502 series notebooks, it is necessary to say Y because of a BIOS bug. 2503 2504config APM_DO_ENABLE 2505 bool "Enable PM at boot time" 2506 ---help--- 2507 Enable APM features at boot time. From page 36 of the APM BIOS 2508 specification: "When disabled, the APM BIOS does not automatically 2509 power manage devices, enter the Standby State, enter the Suspend 2510 State, or take power saving steps in response to CPU Idle calls." 2511 This driver will make CPU Idle calls when Linux is idle (unless this 2512 feature is turned off -- see "Do CPU IDLE calls", below). This 2513 should always save battery power, but more complicated APM features 2514 will be dependent on your BIOS implementation. You may need to turn 2515 this option off if your computer hangs at boot time when using APM 2516 support, or if it beeps continuously instead of suspending. Turn 2517 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2518 T400CDT. This is off by default since most machines do fine without 2519 this feature. 2520 2521config APM_CPU_IDLE 2522 depends on CPU_IDLE 2523 bool "Make CPU Idle calls when idle" 2524 ---help--- 2525 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2526 On some machines, this can activate improved power savings, such as 2527 a slowed CPU clock rate, when the machine is idle. These idle calls 2528 are made after the idle loop has run for some length of time (e.g., 2529 333 mS). On some machines, this will cause a hang at boot time or 2530 whenever the CPU becomes idle. (On machines with more than one CPU, 2531 this option does nothing.) 2532 2533config APM_DISPLAY_BLANK 2534 bool "Enable console blanking using APM" 2535 ---help--- 2536 Enable console blanking using the APM. Some laptops can use this to 2537 turn off the LCD backlight when the screen blanker of the Linux 2538 virtual console blanks the screen. Note that this is only used by 2539 the virtual console screen blanker, and won't turn off the backlight 2540 when using the X Window system. This also doesn't have anything to 2541 do with your VESA-compliant power-saving monitor. Further, this 2542 option doesn't work for all laptops -- it might not turn off your 2543 backlight at all, or it might print a lot of errors to the console, 2544 especially if you are using gpm. 2545 2546config APM_ALLOW_INTS 2547 bool "Allow interrupts during APM BIOS calls" 2548 ---help--- 2549 Normally we disable external interrupts while we are making calls to 2550 the APM BIOS as a measure to lessen the effects of a badly behaving 2551 BIOS implementation. The BIOS should reenable interrupts if it 2552 needs to. Unfortunately, some BIOSes do not -- especially those in 2553 many of the newer IBM Thinkpads. If you experience hangs when you 2554 suspend, try setting this to Y. Otherwise, say N. 2555 2556endif # APM 2557 2558source "drivers/cpufreq/Kconfig" 2559 2560source "drivers/cpuidle/Kconfig" 2561 2562source "drivers/idle/Kconfig" 2563 2564endmenu 2565 2566 2567menu "Bus options (PCI etc.)" 2568 2569config PCI 2570 bool "PCI support" 2571 default y 2572 ---help--- 2573 Find out whether you have a PCI motherboard. PCI is the name of a 2574 bus system, i.e. the way the CPU talks to the other stuff inside 2575 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2576 VESA. If you have PCI, say Y, otherwise N. 2577 2578choice 2579 prompt "PCI access mode" 2580 depends on X86_32 && PCI 2581 default PCI_GOANY 2582 ---help--- 2583 On PCI systems, the BIOS can be used to detect the PCI devices and 2584 determine their configuration. However, some old PCI motherboards 2585 have BIOS bugs and may crash if this is done. Also, some embedded 2586 PCI-based systems don't have any BIOS at all. Linux can also try to 2587 detect the PCI hardware directly without using the BIOS. 2588 2589 With this option, you can specify how Linux should detect the 2590 PCI devices. If you choose "BIOS", the BIOS will be used, 2591 if you choose "Direct", the BIOS won't be used, and if you 2592 choose "MMConfig", then PCI Express MMCONFIG will be used. 2593 If you choose "Any", the kernel will try MMCONFIG, then the 2594 direct access method and falls back to the BIOS if that doesn't 2595 work. If unsure, go with the default, which is "Any". 2596 2597config PCI_GOBIOS 2598 bool "BIOS" 2599 2600config PCI_GOMMCONFIG 2601 bool "MMConfig" 2602 2603config PCI_GODIRECT 2604 bool "Direct" 2605 2606config PCI_GOOLPC 2607 bool "OLPC XO-1" 2608 depends on OLPC 2609 2610config PCI_GOANY 2611 bool "Any" 2612 2613endchoice 2614 2615config PCI_BIOS 2616 def_bool y 2617 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2618 2619# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2620config PCI_DIRECT 2621 def_bool y 2622 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2623 2624config PCI_MMCONFIG 2625 bool "Support mmconfig PCI config space access" if X86_64 2626 default y 2627 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2628 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2629 2630config PCI_OLPC 2631 def_bool y 2632 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2633 2634config PCI_XEN 2635 def_bool y 2636 depends on PCI && XEN 2637 select SWIOTLB_XEN 2638 2639config PCI_DOMAINS 2640 def_bool y 2641 depends on PCI 2642 2643config MMCONF_FAM10H 2644 def_bool y 2645 depends on X86_64 && PCI_MMCONFIG && ACPI 2646 2647config PCI_CNB20LE_QUIRK 2648 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2649 depends on PCI 2650 help 2651 Read the PCI windows out of the CNB20LE host bridge. This allows 2652 PCI hotplug to work on systems with the CNB20LE chipset which do 2653 not have ACPI. 2654 2655 There's no public spec for this chipset, and this functionality 2656 is known to be incomplete. 2657 2658 You should say N unless you know you need this. 2659 2660source "drivers/pci/Kconfig" 2661 2662config ISA_BUS 2663 bool "ISA bus support on modern systems" if EXPERT 2664 help 2665 Expose ISA bus device drivers and options available for selection and 2666 configuration. Enable this option if your target machine has an ISA 2667 bus. ISA is an older system, displaced by PCI and newer bus 2668 architectures -- if your target machine is modern, it probably does 2669 not have an ISA bus. 2670 2671 If unsure, say N. 2672 2673# x86_64 have no ISA slots, but can have ISA-style DMA. 2674config ISA_DMA_API 2675 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2676 default y 2677 help 2678 Enables ISA-style DMA support for devices requiring such controllers. 2679 If unsure, say Y. 2680 2681if X86_32 2682 2683config ISA 2684 bool "ISA support" 2685 ---help--- 2686 Find out whether you have ISA slots on your motherboard. ISA is the 2687 name of a bus system, i.e. the way the CPU talks to the other stuff 2688 inside your box. Other bus systems are PCI, EISA, MicroChannel 2689 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2690 newer boards don't support it. If you have ISA, say Y, otherwise N. 2691 2692config EISA 2693 bool "EISA support" 2694 depends on ISA 2695 ---help--- 2696 The Extended Industry Standard Architecture (EISA) bus was 2697 developed as an open alternative to the IBM MicroChannel bus. 2698 2699 The EISA bus provided some of the features of the IBM MicroChannel 2700 bus while maintaining backward compatibility with cards made for 2701 the older ISA bus. The EISA bus saw limited use between 1988 and 2702 1995 when it was made obsolete by the PCI bus. 2703 2704 Say Y here if you are building a kernel for an EISA-based machine. 2705 2706 Otherwise, say N. 2707 2708source "drivers/eisa/Kconfig" 2709 2710config SCx200 2711 tristate "NatSemi SCx200 support" 2712 ---help--- 2713 This provides basic support for National Semiconductor's 2714 (now AMD's) Geode processors. The driver probes for the 2715 PCI-IDs of several on-chip devices, so its a good dependency 2716 for other scx200_* drivers. 2717 2718 If compiled as a module, the driver is named scx200. 2719 2720config SCx200HR_TIMER 2721 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2722 depends on SCx200 2723 default y 2724 ---help--- 2725 This driver provides a clocksource built upon the on-chip 2726 27MHz high-resolution timer. Its also a workaround for 2727 NSC Geode SC-1100's buggy TSC, which loses time when the 2728 processor goes idle (as is done by the scheduler). The 2729 other workaround is idle=poll boot option. 2730 2731config OLPC 2732 bool "One Laptop Per Child support" 2733 depends on !X86_PAE 2734 select GPIOLIB 2735 select OF 2736 select OF_PROMTREE 2737 select IRQ_DOMAIN 2738 ---help--- 2739 Add support for detecting the unique features of the OLPC 2740 XO hardware. 2741 2742config OLPC_XO1_PM 2743 bool "OLPC XO-1 Power Management" 2744 depends on OLPC && MFD_CS5535 && PM_SLEEP 2745 select MFD_CORE 2746 ---help--- 2747 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2748 2749config OLPC_XO1_RTC 2750 bool "OLPC XO-1 Real Time Clock" 2751 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2752 ---help--- 2753 Add support for the XO-1 real time clock, which can be used as a 2754 programmable wakeup source. 2755 2756config OLPC_XO1_SCI 2757 bool "OLPC XO-1 SCI extras" 2758 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2759 depends on INPUT=y 2760 select POWER_SUPPLY 2761 ---help--- 2762 Add support for SCI-based features of the OLPC XO-1 laptop: 2763 - EC-driven system wakeups 2764 - Power button 2765 - Ebook switch 2766 - Lid switch 2767 - AC adapter status updates 2768 - Battery status updates 2769 2770config OLPC_XO15_SCI 2771 bool "OLPC XO-1.5 SCI extras" 2772 depends on OLPC && ACPI 2773 select POWER_SUPPLY 2774 ---help--- 2775 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2776 - EC-driven system wakeups 2777 - AC adapter status updates 2778 - Battery status updates 2779 2780config ALIX 2781 bool "PCEngines ALIX System Support (LED setup)" 2782 select GPIOLIB 2783 ---help--- 2784 This option enables system support for the PCEngines ALIX. 2785 At present this just sets up LEDs for GPIO control on 2786 ALIX2/3/6 boards. However, other system specific setup should 2787 get added here. 2788 2789 Note: You must still enable the drivers for GPIO and LED support 2790 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2791 2792 Note: You have to set alix.force=1 for boards with Award BIOS. 2793 2794config NET5501 2795 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2796 select GPIOLIB 2797 ---help--- 2798 This option enables system support for the Soekris Engineering net5501. 2799 2800config GEOS 2801 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2802 select GPIOLIB 2803 depends on DMI 2804 ---help--- 2805 This option enables system support for the Traverse Technologies GEOS. 2806 2807config TS5500 2808 bool "Technologic Systems TS-5500 platform support" 2809 depends on MELAN 2810 select CHECK_SIGNATURE 2811 select NEW_LEDS 2812 select LEDS_CLASS 2813 ---help--- 2814 This option enables system support for the Technologic Systems TS-5500. 2815 2816endif # X86_32 2817 2818config AMD_NB 2819 def_bool y 2820 depends on CPU_SUP_AMD && PCI 2821 2822source "drivers/pcmcia/Kconfig" 2823 2824config RAPIDIO 2825 tristate "RapidIO support" 2826 depends on PCI 2827 default n 2828 help 2829 If enabled this option will include drivers and the core 2830 infrastructure code to support RapidIO interconnect devices. 2831 2832source "drivers/rapidio/Kconfig" 2833 2834config X86_SYSFB 2835 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2836 help 2837 Firmwares often provide initial graphics framebuffers so the BIOS, 2838 bootloader or kernel can show basic video-output during boot for 2839 user-guidance and debugging. Historically, x86 used the VESA BIOS 2840 Extensions and EFI-framebuffers for this, which are mostly limited 2841 to x86. 2842 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2843 framebuffers so the new generic system-framebuffer drivers can be 2844 used on x86. If the framebuffer is not compatible with the generic 2845 modes, it is adverticed as fallback platform framebuffer so legacy 2846 drivers like efifb, vesafb and uvesafb can pick it up. 2847 If this option is not selected, all system framebuffers are always 2848 marked as fallback platform framebuffers as usual. 2849 2850 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2851 not be able to pick up generic system framebuffers if this option 2852 is selected. You are highly encouraged to enable simplefb as 2853 replacement if you select this option. simplefb can correctly deal 2854 with generic system framebuffers. But you should still keep vesafb 2855 and others enabled as fallback if a system framebuffer is 2856 incompatible with simplefb. 2857 2858 If unsure, say Y. 2859 2860endmenu 2861 2862 2863menu "Binary Emulations" 2864 2865config IA32_EMULATION 2866 bool "IA32 Emulation" 2867 depends on X86_64 2868 select ARCH_WANT_OLD_COMPAT_IPC 2869 select BINFMT_ELF 2870 select COMPAT_BINFMT_ELF 2871 select COMPAT_OLD_SIGACTION 2872 ---help--- 2873 Include code to run legacy 32-bit programs under a 2874 64-bit kernel. You should likely turn this on, unless you're 2875 100% sure that you don't have any 32-bit programs left. 2876 2877config IA32_AOUT 2878 tristate "IA32 a.out support" 2879 depends on IA32_EMULATION 2880 ---help--- 2881 Support old a.out binaries in the 32bit emulation. 2882 2883config X86_X32 2884 bool "x32 ABI for 64-bit mode" 2885 depends on X86_64 2886 ---help--- 2887 Include code to run binaries for the x32 native 32-bit ABI 2888 for 64-bit processors. An x32 process gets access to the 2889 full 64-bit register file and wide data path while leaving 2890 pointers at 32 bits for smaller memory footprint. 2891 2892 You will need a recent binutils (2.22 or later) with 2893 elf32_x86_64 support enabled to compile a kernel with this 2894 option set. 2895 2896config COMPAT_32 2897 def_bool y 2898 depends on IA32_EMULATION || X86_32 2899 select HAVE_UID16 2900 select OLD_SIGSUSPEND3 2901 2902config COMPAT 2903 def_bool y 2904 depends on IA32_EMULATION || X86_X32 2905 2906if COMPAT 2907config COMPAT_FOR_U64_ALIGNMENT 2908 def_bool y 2909 2910config SYSVIPC_COMPAT 2911 def_bool y 2912 depends on SYSVIPC 2913endif 2914 2915endmenu 2916 2917 2918config HAVE_ATOMIC_IOMAP 2919 def_bool y 2920 depends on X86_32 2921 2922config X86_DEV_DMA_OPS 2923 bool 2924 depends on X86_64 || STA2X11 2925 2926config X86_DMA_REMAP 2927 bool 2928 depends on STA2X11 2929 2930config HAVE_GENERIC_GUP 2931 def_bool y 2932 2933source "drivers/firmware/Kconfig" 2934 2935source "arch/x86/kvm/Kconfig" 2936