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_CLOCKSOURCE_INIT 52 select ARCH_DISCARD_MEMBLOCK 53 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 54 select ARCH_HAS_DEBUG_VIRTUAL 55 select ARCH_HAS_DEVMEM_IS_ALLOWED 56 select ARCH_HAS_ELF_RANDOMIZE 57 select ARCH_HAS_FAST_MULTIPLIER 58 select ARCH_HAS_FILTER_PGPROT 59 select ARCH_HAS_FORTIFY_SOURCE 60 select ARCH_HAS_GCOV_PROFILE_ALL 61 select ARCH_HAS_KCOV if X86_64 62 select ARCH_HAS_MEMBARRIER_SYNC_CORE 63 select ARCH_HAS_PMEM_API if X86_64 64 select ARCH_HAS_PTE_SPECIAL 65 select ARCH_HAS_REFCOUNT 66 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 67 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 68 select ARCH_HAS_SET_MEMORY 69 select ARCH_HAS_SG_CHAIN 70 select ARCH_HAS_STRICT_KERNEL_RWX 71 select ARCH_HAS_STRICT_MODULE_RWX 72 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 73 select ARCH_HAS_UBSAN_SANITIZE_ALL 74 select ARCH_HAS_ZONE_DEVICE if X86_64 75 select ARCH_HAVE_NMI_SAFE_CMPXCHG 76 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 77 select ARCH_MIGHT_HAVE_PC_PARPORT 78 select ARCH_MIGHT_HAVE_PC_SERIO 79 select ARCH_SUPPORTS_ACPI 80 select ARCH_SUPPORTS_ATOMIC_RMW 81 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 82 select ARCH_USE_BUILTIN_BSWAP 83 select ARCH_USE_QUEUED_RWLOCKS 84 select ARCH_USE_QUEUED_SPINLOCKS 85 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 86 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 87 select ARCH_WANTS_THP_SWAP if X86_64 88 select BUILDTIME_EXTABLE_SORT 89 select CLKEVT_I8253 90 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 91 select CLOCKSOURCE_WATCHDOG 92 select DCACHE_WORD_ACCESS 93 select DMA_DIRECT_OPS 94 select EDAC_ATOMIC_SCRUB 95 select EDAC_SUPPORT 96 select GENERIC_CLOCKEVENTS 97 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 98 select GENERIC_CLOCKEVENTS_MIN_ADJUST 99 select GENERIC_CMOS_UPDATE 100 select GENERIC_CPU_AUTOPROBE 101 select GENERIC_CPU_VULNERABILITIES 102 select GENERIC_EARLY_IOREMAP 103 select GENERIC_FIND_FIRST_BIT 104 select GENERIC_IOMAP 105 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 106 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 107 select GENERIC_IRQ_MIGRATION if SMP 108 select GENERIC_IRQ_PROBE 109 select GENERIC_IRQ_RESERVATION_MODE 110 select GENERIC_IRQ_SHOW 111 select GENERIC_PENDING_IRQ if SMP 112 select GENERIC_SMP_IDLE_THREAD 113 select GENERIC_STRNCPY_FROM_USER 114 select GENERIC_STRNLEN_USER 115 select GENERIC_TIME_VSYSCALL 116 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 117 select HAVE_ACPI_APEI if ACPI 118 select HAVE_ACPI_APEI_NMI if ACPI 119 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 120 select HAVE_ARCH_AUDITSYSCALL 121 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 122 select HAVE_ARCH_JUMP_LABEL 123 select HAVE_ARCH_JUMP_LABEL_RELATIVE 124 select HAVE_ARCH_KASAN if X86_64 125 select HAVE_ARCH_KGDB 126 select HAVE_ARCH_MMAP_RND_BITS if MMU 127 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 128 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 129 select HAVE_ARCH_PREL32_RELOCATIONS 130 select HAVE_ARCH_SECCOMP_FILTER 131 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 132 select HAVE_ARCH_STACKLEAK 133 select HAVE_ARCH_TRACEHOOK 134 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 135 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 136 select HAVE_ARCH_VMAP_STACK if X86_64 137 select HAVE_ARCH_WITHIN_STACK_FRAMES 138 select HAVE_CMPXCHG_DOUBLE 139 select HAVE_CMPXCHG_LOCAL 140 select HAVE_CONTEXT_TRACKING if X86_64 141 select HAVE_COPY_THREAD_TLS 142 select HAVE_C_RECORDMCOUNT 143 select HAVE_DEBUG_KMEMLEAK 144 select HAVE_DEBUG_STACKOVERFLOW 145 select HAVE_DMA_CONTIGUOUS 146 select HAVE_DYNAMIC_FTRACE 147 select HAVE_DYNAMIC_FTRACE_WITH_REGS 148 select HAVE_EBPF_JIT 149 select HAVE_EFFICIENT_UNALIGNED_ACCESS 150 select HAVE_EXIT_THREAD 151 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 152 select HAVE_FTRACE_MCOUNT_RECORD 153 select HAVE_FUNCTION_GRAPH_TRACER 154 select HAVE_FUNCTION_TRACER 155 select HAVE_GCC_PLUGINS 156 select HAVE_HW_BREAKPOINT 157 select HAVE_IDE 158 select HAVE_IOREMAP_PROT 159 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 160 select HAVE_IRQ_TIME_ACCOUNTING 161 select HAVE_KERNEL_BZIP2 162 select HAVE_KERNEL_GZIP 163 select HAVE_KERNEL_LZ4 164 select HAVE_KERNEL_LZMA 165 select HAVE_KERNEL_LZO 166 select HAVE_KERNEL_XZ 167 select HAVE_KPROBES 168 select HAVE_KPROBES_ON_FTRACE 169 select HAVE_FUNCTION_ERROR_INJECTION 170 select HAVE_KRETPROBES 171 select HAVE_KVM 172 select HAVE_LIVEPATCH if X86_64 173 select HAVE_MEMBLOCK_NODE_MAP 174 select HAVE_MIXED_BREAKPOINTS_REGS 175 select HAVE_MOD_ARCH_SPECIFIC 176 select HAVE_NMI 177 select HAVE_OPROFILE 178 select HAVE_OPTPROBES 179 select HAVE_PCSPKR_PLATFORM 180 select HAVE_PERF_EVENTS 181 select HAVE_PERF_EVENTS_NMI 182 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 183 select HAVE_PERF_REGS 184 select HAVE_PERF_USER_STACK_DUMP 185 select HAVE_RCU_TABLE_FREE if PARAVIRT 186 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 187 select HAVE_REGS_AND_STACK_ACCESS_API 188 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 189 select HAVE_FUNCTION_ARG_ACCESS_API 190 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 191 select HAVE_STACK_VALIDATION if X86_64 192 select HAVE_RSEQ 193 select HAVE_SYSCALL_TRACEPOINTS 194 select HAVE_UNSTABLE_SCHED_CLOCK 195 select HAVE_USER_RETURN_NOTIFIER 196 select HOTPLUG_SMT if SMP 197 select IRQ_FORCED_THREADING 198 select NEED_SG_DMA_LENGTH 199 select PCI_LOCKLESS_CONFIG 200 select PERF_EVENTS 201 select RTC_LIB 202 select RTC_MC146818_LIB 203 select SPARSE_IRQ 204 select SRCU 205 select SYSCTL_EXCEPTION_TRACE 206 select THREAD_INFO_IN_TASK 207 select USER_STACKTRACE_SUPPORT 208 select VIRT_TO_BUS 209 select X86_FEATURE_NAMES if PROC_FS 210 211config INSTRUCTION_DECODER 212 def_bool y 213 depends on KPROBES || PERF_EVENTS || UPROBES 214 215config OUTPUT_FORMAT 216 string 217 default "elf32-i386" if X86_32 218 default "elf64-x86-64" if X86_64 219 220config ARCH_DEFCONFIG 221 string 222 default "arch/x86/configs/i386_defconfig" if X86_32 223 default "arch/x86/configs/x86_64_defconfig" if X86_64 224 225config LOCKDEP_SUPPORT 226 def_bool y 227 228config STACKTRACE_SUPPORT 229 def_bool y 230 231config MMU 232 def_bool y 233 234config ARCH_MMAP_RND_BITS_MIN 235 default 28 if 64BIT 236 default 8 237 238config ARCH_MMAP_RND_BITS_MAX 239 default 32 if 64BIT 240 default 16 241 242config ARCH_MMAP_RND_COMPAT_BITS_MIN 243 default 8 244 245config ARCH_MMAP_RND_COMPAT_BITS_MAX 246 default 16 247 248config SBUS 249 bool 250 251config GENERIC_ISA_DMA 252 def_bool y 253 depends on ISA_DMA_API 254 255config GENERIC_BUG 256 def_bool y 257 depends on BUG 258 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 259 260config GENERIC_BUG_RELATIVE_POINTERS 261 bool 262 263config GENERIC_HWEIGHT 264 def_bool y 265 266config ARCH_MAY_HAVE_PC_FDC 267 def_bool y 268 depends on ISA_DMA_API 269 270config RWSEM_XCHGADD_ALGORITHM 271 def_bool y 272 273config GENERIC_CALIBRATE_DELAY 274 def_bool y 275 276config ARCH_HAS_CPU_RELAX 277 def_bool y 278 279config ARCH_HAS_CACHE_LINE_SIZE 280 def_bool y 281 282config ARCH_HAS_FILTER_PGPROT 283 def_bool y 284 285config HAVE_SETUP_PER_CPU_AREA 286 def_bool y 287 288config NEED_PER_CPU_EMBED_FIRST_CHUNK 289 def_bool y 290 291config NEED_PER_CPU_PAGE_FIRST_CHUNK 292 def_bool y 293 294config ARCH_HIBERNATION_POSSIBLE 295 def_bool y 296 297config ARCH_SUSPEND_POSSIBLE 298 def_bool y 299 300config ARCH_WANT_HUGE_PMD_SHARE 301 def_bool y 302 303config ARCH_WANT_GENERAL_HUGETLB 304 def_bool y 305 306config ZONE_DMA32 307 def_bool y if X86_64 308 309config AUDIT_ARCH 310 def_bool y if X86_64 311 312config ARCH_SUPPORTS_OPTIMIZED_INLINING 313 def_bool y 314 315config ARCH_SUPPORTS_DEBUG_PAGEALLOC 316 def_bool y 317 318config KASAN_SHADOW_OFFSET 319 hex 320 depends on KASAN 321 default 0xdffffc0000000000 322 323config HAVE_INTEL_TXT 324 def_bool y 325 depends on INTEL_IOMMU && ACPI 326 327config X86_32_SMP 328 def_bool y 329 depends on X86_32 && SMP 330 331config X86_64_SMP 332 def_bool y 333 depends on X86_64 && SMP 334 335config X86_32_LAZY_GS 336 def_bool y 337 depends on X86_32 && !STACKPROTECTOR 338 339config ARCH_SUPPORTS_UPROBES 340 def_bool y 341 342config FIX_EARLYCON_MEM 343 def_bool y 344 345config DYNAMIC_PHYSICAL_MASK 346 bool 347 348config PGTABLE_LEVELS 349 int 350 default 5 if X86_5LEVEL 351 default 4 if X86_64 352 default 3 if X86_PAE 353 default 2 354 355config CC_HAS_SANE_STACKPROTECTOR 356 bool 357 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 358 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 359 help 360 We have to make sure stack protector is unconditionally disabled if 361 the compiler produces broken code. 362 363menu "Processor type and features" 364 365config ZONE_DMA 366 bool "DMA memory allocation support" if EXPERT 367 default y 368 help 369 DMA memory allocation support allows devices with less than 32-bit 370 addressing to allocate within the first 16MB of address space. 371 Disable if no such devices will be used. 372 373 If unsure, say Y. 374 375config SMP 376 bool "Symmetric multi-processing support" 377 ---help--- 378 This enables support for systems with more than one CPU. If you have 379 a system with only one CPU, say N. If you have a system with more 380 than one CPU, say Y. 381 382 If you say N here, the kernel will run on uni- and multiprocessor 383 machines, but will use only one CPU of a multiprocessor machine. If 384 you say Y here, the kernel will run on many, but not all, 385 uniprocessor machines. On a uniprocessor machine, the kernel 386 will run faster if you say N here. 387 388 Note that if you say Y here and choose architecture "586" or 389 "Pentium" under "Processor family", the kernel will not work on 486 390 architectures. Similarly, multiprocessor kernels for the "PPro" 391 architecture may not work on all Pentium based boards. 392 393 People using multiprocessor machines who say Y here should also say 394 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 395 Management" code will be disabled if you say Y here. 396 397 See also <file:Documentation/x86/i386/IO-APIC.txt>, 398 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 399 <http://www.tldp.org/docs.html#howto>. 400 401 If you don't know what to do here, say N. 402 403config X86_FEATURE_NAMES 404 bool "Processor feature human-readable names" if EMBEDDED 405 default y 406 ---help--- 407 This option compiles in a table of x86 feature bits and corresponding 408 names. This is required to support /proc/cpuinfo and a few kernel 409 messages. You can disable this to save space, at the expense of 410 making those few kernel messages show numeric feature bits instead. 411 412 If in doubt, say Y. 413 414config X86_X2APIC 415 bool "Support x2apic" 416 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 417 ---help--- 418 This enables x2apic support on CPUs that have this feature. 419 420 This allows 32-bit apic IDs (so it can support very large systems), 421 and accesses the local apic via MSRs not via mmio. 422 423 If you don't know what to do here, say N. 424 425config X86_MPPARSE 426 bool "Enable MPS table" if ACPI || SFI 427 default y 428 depends on X86_LOCAL_APIC 429 ---help--- 430 For old smp systems that do not have proper acpi support. Newer systems 431 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 432 433config GOLDFISH 434 def_bool y 435 depends on X86_GOLDFISH 436 437config RETPOLINE 438 bool "Avoid speculative indirect branches in kernel" 439 default y 440 select STACK_VALIDATION if HAVE_STACK_VALIDATION 441 help 442 Compile kernel with the retpoline compiler options to guard against 443 kernel-to-user data leaks by avoiding speculative indirect 444 branches. Requires a compiler with -mindirect-branch=thunk-extern 445 support for full protection. The kernel may run slower. 446 447config INTEL_RDT 448 bool "Intel Resource Director Technology support" 449 depends on X86 && CPU_SUP_INTEL 450 select KERNFS 451 help 452 Select to enable resource allocation and monitoring which are 453 sub-features of Intel Resource Director Technology(RDT). More 454 information about RDT can be found in the Intel x86 455 Architecture Software Developer Manual. 456 457 Say N if unsure. 458 459if X86_32 460config X86_BIGSMP 461 bool "Support for big SMP systems with more than 8 CPUs" 462 depends on SMP 463 ---help--- 464 This option is needed for the systems that have more than 8 CPUs 465 466config X86_EXTENDED_PLATFORM 467 bool "Support for extended (non-PC) x86 platforms" 468 default y 469 ---help--- 470 If you disable this option then the kernel will only support 471 standard PC platforms. (which covers the vast majority of 472 systems out there.) 473 474 If you enable this option then you'll be able to select support 475 for the following (non-PC) 32 bit x86 platforms: 476 Goldfish (Android emulator) 477 AMD Elan 478 RDC R-321x SoC 479 SGI 320/540 (Visual Workstation) 480 STA2X11-based (e.g. Northville) 481 Moorestown MID devices 482 483 If you have one of these systems, or if you want to build a 484 generic distribution kernel, say Y here - otherwise say N. 485endif 486 487if X86_64 488config X86_EXTENDED_PLATFORM 489 bool "Support for extended (non-PC) x86 platforms" 490 default y 491 ---help--- 492 If you disable this option then the kernel will only support 493 standard PC platforms. (which covers the vast majority of 494 systems out there.) 495 496 If you enable this option then you'll be able to select support 497 for the following (non-PC) 64 bit x86 platforms: 498 Numascale NumaChip 499 ScaleMP vSMP 500 SGI Ultraviolet 501 502 If you have one of these systems, or if you want to build a 503 generic distribution kernel, say Y here - otherwise say N. 504endif 505# This is an alphabetically sorted list of 64 bit extended platforms 506# Please maintain the alphabetic order if and when there are additions 507config X86_NUMACHIP 508 bool "Numascale NumaChip" 509 depends on X86_64 510 depends on X86_EXTENDED_PLATFORM 511 depends on NUMA 512 depends on SMP 513 depends on X86_X2APIC 514 depends on PCI_MMCONFIG 515 ---help--- 516 Adds support for Numascale NumaChip large-SMP systems. Needed to 517 enable more than ~168 cores. 518 If you don't have one of these, you should say N here. 519 520config X86_VSMP 521 bool "ScaleMP vSMP" 522 select HYPERVISOR_GUEST 523 select PARAVIRT 524 depends on X86_64 && PCI 525 depends on X86_EXTENDED_PLATFORM 526 depends on SMP 527 ---help--- 528 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 529 supposed to run on these EM64T-based machines. Only choose this option 530 if you have one of these machines. 531 532config X86_UV 533 bool "SGI Ultraviolet" 534 depends on X86_64 535 depends on X86_EXTENDED_PLATFORM 536 depends on NUMA 537 depends on EFI 538 depends on X86_X2APIC 539 depends on PCI 540 ---help--- 541 This option is needed in order to support SGI Ultraviolet systems. 542 If you don't have one of these, you should say N here. 543 544# Following is an alphabetically sorted list of 32 bit extended platforms 545# Please maintain the alphabetic order if and when there are additions 546 547config X86_GOLDFISH 548 bool "Goldfish (Virtual Platform)" 549 depends on X86_EXTENDED_PLATFORM 550 ---help--- 551 Enable support for the Goldfish virtual platform used primarily 552 for Android development. Unless you are building for the Android 553 Goldfish emulator say N here. 554 555config X86_INTEL_CE 556 bool "CE4100 TV platform" 557 depends on PCI 558 depends on PCI_GODIRECT 559 depends on X86_IO_APIC 560 depends on X86_32 561 depends on X86_EXTENDED_PLATFORM 562 select X86_REBOOTFIXUPS 563 select OF 564 select OF_EARLY_FLATTREE 565 ---help--- 566 Select for the Intel CE media processor (CE4100) SOC. 567 This option compiles in support for the CE4100 SOC for settop 568 boxes and media devices. 569 570config X86_INTEL_MID 571 bool "Intel MID platform support" 572 depends on X86_EXTENDED_PLATFORM 573 depends on X86_PLATFORM_DEVICES 574 depends on PCI 575 depends on X86_64 || (PCI_GOANY && X86_32) 576 depends on X86_IO_APIC 577 select SFI 578 select I2C 579 select DW_APB_TIMER 580 select APB_TIMER 581 select INTEL_SCU_IPC 582 select MFD_INTEL_MSIC 583 ---help--- 584 Select to build a kernel capable of supporting Intel MID (Mobile 585 Internet Device) platform systems which do not have the PCI legacy 586 interfaces. If you are building for a PC class system say N here. 587 588 Intel MID platforms are based on an Intel processor and chipset which 589 consume less power than most of the x86 derivatives. 590 591config X86_INTEL_QUARK 592 bool "Intel Quark platform support" 593 depends on X86_32 594 depends on X86_EXTENDED_PLATFORM 595 depends on X86_PLATFORM_DEVICES 596 depends on X86_TSC 597 depends on PCI 598 depends on PCI_GOANY 599 depends on X86_IO_APIC 600 select IOSF_MBI 601 select INTEL_IMR 602 select COMMON_CLK 603 ---help--- 604 Select to include support for Quark X1000 SoC. 605 Say Y here if you have a Quark based system such as the Arduino 606 compatible Intel Galileo. 607 608config X86_INTEL_LPSS 609 bool "Intel Low Power Subsystem Support" 610 depends on X86 && ACPI 611 select COMMON_CLK 612 select PINCTRL 613 select IOSF_MBI 614 ---help--- 615 Select to build support for Intel Low Power Subsystem such as 616 found on Intel Lynxpoint PCH. Selecting this option enables 617 things like clock tree (common clock framework) and pincontrol 618 which are needed by the LPSS peripheral drivers. 619 620config X86_AMD_PLATFORM_DEVICE 621 bool "AMD ACPI2Platform devices support" 622 depends on ACPI 623 select COMMON_CLK 624 select PINCTRL 625 ---help--- 626 Select to interpret AMD specific ACPI device to platform device 627 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 628 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 629 implemented under PINCTRL subsystem. 630 631config IOSF_MBI 632 tristate "Intel SoC IOSF Sideband support for SoC platforms" 633 depends on PCI 634 ---help--- 635 This option enables sideband register access support for Intel SoC 636 platforms. On these platforms the IOSF sideband is used in lieu of 637 MSR's for some register accesses, mostly but not limited to thermal 638 and power. Drivers may query the availability of this device to 639 determine if they need the sideband in order to work on these 640 platforms. The sideband is available on the following SoC products. 641 This list is not meant to be exclusive. 642 - BayTrail 643 - Braswell 644 - Quark 645 646 You should say Y if you are running a kernel on one of these SoC's. 647 648config IOSF_MBI_DEBUG 649 bool "Enable IOSF sideband access through debugfs" 650 depends on IOSF_MBI && DEBUG_FS 651 ---help--- 652 Select this option to expose the IOSF sideband access registers (MCR, 653 MDR, MCRX) through debugfs to write and read register information from 654 different units on the SoC. This is most useful for obtaining device 655 state information for debug and analysis. As this is a general access 656 mechanism, users of this option would have specific knowledge of the 657 device they want to access. 658 659 If you don't require the option or are in doubt, say N. 660 661config X86_RDC321X 662 bool "RDC R-321x SoC" 663 depends on X86_32 664 depends on X86_EXTENDED_PLATFORM 665 select M486 666 select X86_REBOOTFIXUPS 667 ---help--- 668 This option is needed for RDC R-321x system-on-chip, also known 669 as R-8610-(G). 670 If you don't have one of these chips, you should say N here. 671 672config X86_32_NON_STANDARD 673 bool "Support non-standard 32-bit SMP architectures" 674 depends on X86_32 && SMP 675 depends on X86_EXTENDED_PLATFORM 676 ---help--- 677 This option compiles in the bigsmp and STA2X11 default 678 subarchitectures. It is intended for a generic binary 679 kernel. If you select them all, kernel will probe it one by 680 one and will fallback to default. 681 682# Alphabetically sorted list of Non standard 32 bit platforms 683 684config X86_SUPPORTS_MEMORY_FAILURE 685 def_bool y 686 # MCE code calls memory_failure(): 687 depends on X86_MCE 688 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 689 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 690 depends on X86_64 || !SPARSEMEM 691 select ARCH_SUPPORTS_MEMORY_FAILURE 692 693config STA2X11 694 bool "STA2X11 Companion Chip Support" 695 depends on X86_32_NON_STANDARD && PCI 696 select ARCH_HAS_PHYS_TO_DMA 697 select X86_DEV_DMA_OPS 698 select X86_DMA_REMAP 699 select SWIOTLB 700 select MFD_STA2X11 701 select GPIOLIB 702 ---help--- 703 This adds support for boards based on the STA2X11 IO-Hub, 704 a.k.a. "ConneXt". The chip is used in place of the standard 705 PC chipset, so all "standard" peripherals are missing. If this 706 option is selected the kernel will still be able to boot on 707 standard PC machines. 708 709config X86_32_IRIS 710 tristate "Eurobraille/Iris poweroff module" 711 depends on X86_32 712 ---help--- 713 The Iris machines from EuroBraille do not have APM or ACPI support 714 to shut themselves down properly. A special I/O sequence is 715 needed to do so, which is what this module does at 716 kernel shutdown. 717 718 This is only for Iris machines from EuroBraille. 719 720 If unused, say N. 721 722config SCHED_OMIT_FRAME_POINTER 723 def_bool y 724 prompt "Single-depth WCHAN output" 725 depends on X86 726 ---help--- 727 Calculate simpler /proc/<PID>/wchan values. If this option 728 is disabled then wchan values will recurse back to the 729 caller function. This provides more accurate wchan values, 730 at the expense of slightly more scheduling overhead. 731 732 If in doubt, say "Y". 733 734menuconfig HYPERVISOR_GUEST 735 bool "Linux guest support" 736 ---help--- 737 Say Y here to enable options for running Linux under various hyper- 738 visors. This option enables basic hypervisor detection and platform 739 setup. 740 741 If you say N, all options in this submenu will be skipped and 742 disabled, and Linux guest support won't be built in. 743 744if HYPERVISOR_GUEST 745 746config PARAVIRT 747 bool "Enable paravirtualization code" 748 ---help--- 749 This changes the kernel so it can modify itself when it is run 750 under a hypervisor, potentially improving performance significantly 751 over full virtualization. However, when run without a hypervisor 752 the kernel is theoretically slower and slightly larger. 753 754config PARAVIRT_XXL 755 bool 756 757config PARAVIRT_DEBUG 758 bool "paravirt-ops debugging" 759 depends on PARAVIRT && DEBUG_KERNEL 760 ---help--- 761 Enable to debug paravirt_ops internals. Specifically, BUG if 762 a paravirt_op is missing when it is called. 763 764config PARAVIRT_SPINLOCKS 765 bool "Paravirtualization layer for spinlocks" 766 depends on PARAVIRT && SMP 767 ---help--- 768 Paravirtualized spinlocks allow a pvops backend to replace the 769 spinlock implementation with something virtualization-friendly 770 (for example, block the virtual CPU rather than spinning). 771 772 It has a minimal impact on native kernels and gives a nice performance 773 benefit on paravirtualized KVM / Xen kernels. 774 775 If you are unsure how to answer this question, answer Y. 776 777config QUEUED_LOCK_STAT 778 bool "Paravirt queued spinlock statistics" 779 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 780 ---help--- 781 Enable the collection of statistical data on the slowpath 782 behavior of paravirtualized queued spinlocks and report 783 them on debugfs. 784 785source "arch/x86/xen/Kconfig" 786 787config KVM_GUEST 788 bool "KVM Guest support (including kvmclock)" 789 depends on PARAVIRT 790 select PARAVIRT_CLOCK 791 default y 792 ---help--- 793 This option enables various optimizations for running under the KVM 794 hypervisor. It includes a paravirtualized clock, so that instead 795 of relying on a PIT (or probably other) emulation by the 796 underlying device model, the host provides the guest with 797 timing infrastructure such as time of day, and system time 798 799config PVH 800 bool "Support for running PVH guests" 801 ---help--- 802 This option enables the PVH entry point for guest virtual machines 803 as specified in the x86/HVM direct boot ABI. 804 805config KVM_DEBUG_FS 806 bool "Enable debug information for KVM Guests in debugfs" 807 depends on KVM_GUEST && DEBUG_FS 808 ---help--- 809 This option enables collection of various statistics for KVM guest. 810 Statistics are displayed in debugfs filesystem. Enabling this option 811 may incur significant overhead. 812 813config PARAVIRT_TIME_ACCOUNTING 814 bool "Paravirtual steal time accounting" 815 depends on PARAVIRT 816 ---help--- 817 Select this option to enable fine granularity task steal time 818 accounting. Time spent executing other tasks in parallel with 819 the current vCPU is discounted from the vCPU power. To account for 820 that, there can be a small performance impact. 821 822 If in doubt, say N here. 823 824config PARAVIRT_CLOCK 825 bool 826 827config JAILHOUSE_GUEST 828 bool "Jailhouse non-root cell support" 829 depends on X86_64 && PCI 830 select X86_PM_TIMER 831 ---help--- 832 This option allows to run Linux as guest in a Jailhouse non-root 833 cell. You can leave this option disabled if you only want to start 834 Jailhouse and run Linux afterwards in the root cell. 835 836endif #HYPERVISOR_GUEST 837 838source "arch/x86/Kconfig.cpu" 839 840config HPET_TIMER 841 def_bool X86_64 842 prompt "HPET Timer Support" if X86_32 843 ---help--- 844 Use the IA-PC HPET (High Precision Event Timer) to manage 845 time in preference to the PIT and RTC, if a HPET is 846 present. 847 HPET is the next generation timer replacing legacy 8254s. 848 The HPET provides a stable time base on SMP 849 systems, unlike the TSC, but it is more expensive to access, 850 as it is off-chip. The interface used is documented 851 in the HPET spec, revision 1. 852 853 You can safely choose Y here. However, HPET will only be 854 activated if the platform and the BIOS support this feature. 855 Otherwise the 8254 will be used for timing services. 856 857 Choose N to continue using the legacy 8254 timer. 858 859config HPET_EMULATE_RTC 860 def_bool y 861 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 862 863config APB_TIMER 864 def_bool y if X86_INTEL_MID 865 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 866 select DW_APB_TIMER 867 depends on X86_INTEL_MID && SFI 868 help 869 APB timer is the replacement for 8254, HPET on X86 MID platforms. 870 The APBT provides a stable time base on SMP 871 systems, unlike the TSC, but it is more expensive to access, 872 as it is off-chip. APB timers are always running regardless of CPU 873 C states, they are used as per CPU clockevent device when possible. 874 875# Mark as expert because too many people got it wrong. 876# The code disables itself when not needed. 877config DMI 878 default y 879 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 880 bool "Enable DMI scanning" if EXPERT 881 ---help--- 882 Enabled scanning of DMI to identify machine quirks. Say Y 883 here unless you have verified that your setup is not 884 affected by entries in the DMI blacklist. Required by PNP 885 BIOS code. 886 887config GART_IOMMU 888 bool "Old AMD GART IOMMU support" 889 select IOMMU_HELPER 890 select SWIOTLB 891 depends on X86_64 && PCI && AMD_NB 892 ---help--- 893 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 894 GART based hardware IOMMUs. 895 896 The GART supports full DMA access for devices with 32-bit access 897 limitations, on systems with more than 3 GB. This is usually needed 898 for USB, sound, many IDE/SATA chipsets and some other devices. 899 900 Newer systems typically have a modern AMD IOMMU, supported via 901 the CONFIG_AMD_IOMMU=y config option. 902 903 In normal configurations this driver is only active when needed: 904 there's more than 3 GB of memory and the system contains a 905 32-bit limited device. 906 907 If unsure, say Y. 908 909config CALGARY_IOMMU 910 bool "IBM Calgary IOMMU support" 911 select IOMMU_HELPER 912 select SWIOTLB 913 depends on X86_64 && PCI 914 ---help--- 915 Support for hardware IOMMUs in IBM's xSeries x366 and x460 916 systems. Needed to run systems with more than 3GB of memory 917 properly with 32-bit PCI devices that do not support DAC 918 (Double Address Cycle). Calgary also supports bus level 919 isolation, where all DMAs pass through the IOMMU. This 920 prevents them from going anywhere except their intended 921 destination. This catches hard-to-find kernel bugs and 922 mis-behaving drivers and devices that do not use the DMA-API 923 properly to set up their DMA buffers. The IOMMU can be 924 turned off at boot time with the iommu=off parameter. 925 Normally the kernel will make the right choice by itself. 926 If unsure, say Y. 927 928config CALGARY_IOMMU_ENABLED_BY_DEFAULT 929 def_bool y 930 prompt "Should Calgary be enabled by default?" 931 depends on CALGARY_IOMMU 932 ---help--- 933 Should Calgary be enabled by default? if you choose 'y', Calgary 934 will be used (if it exists). If you choose 'n', Calgary will not be 935 used even if it exists. If you choose 'n' and would like to use 936 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 937 If unsure, say Y. 938 939config MAXSMP 940 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 941 depends on X86_64 && SMP && DEBUG_KERNEL 942 select CPUMASK_OFFSTACK 943 ---help--- 944 Enable maximum number of CPUS and NUMA Nodes for this architecture. 945 If unsure, say N. 946 947# 948# The maximum number of CPUs supported: 949# 950# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 951# and which can be configured interactively in the 952# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 953# 954# The ranges are different on 32-bit and 64-bit kernels, depending on 955# hardware capabilities and scalability features of the kernel. 956# 957# ( If MAXSMP is enabled we just use the highest possible value and disable 958# interactive configuration. ) 959# 960 961config NR_CPUS_RANGE_BEGIN 962 int 963 default NR_CPUS_RANGE_END if MAXSMP 964 default 1 if !SMP 965 default 2 966 967config NR_CPUS_RANGE_END 968 int 969 depends on X86_32 970 default 64 if SMP && X86_BIGSMP 971 default 8 if SMP && !X86_BIGSMP 972 default 1 if !SMP 973 974config NR_CPUS_RANGE_END 975 int 976 depends on X86_64 977 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 978 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 979 default 1 if !SMP 980 981config NR_CPUS_DEFAULT 982 int 983 depends on X86_32 984 default 32 if X86_BIGSMP 985 default 8 if SMP 986 default 1 if !SMP 987 988config NR_CPUS_DEFAULT 989 int 990 depends on X86_64 991 default 8192 if MAXSMP 992 default 64 if SMP 993 default 1 if !SMP 994 995config NR_CPUS 996 int "Maximum number of CPUs" if SMP && !MAXSMP 997 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 998 default NR_CPUS_DEFAULT 999 ---help--- 1000 This allows you to specify the maximum number of CPUs which this 1001 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1002 supported value is 8192, otherwise the maximum value is 512. The 1003 minimum value which makes sense is 2. 1004 1005 This is purely to save memory: each supported CPU adds about 8KB 1006 to the kernel image. 1007 1008config SCHED_SMT 1009 def_bool y if SMP 1010 1011config SCHED_MC 1012 def_bool y 1013 prompt "Multi-core scheduler support" 1014 depends on SMP 1015 ---help--- 1016 Multi-core scheduler support improves the CPU scheduler's decision 1017 making when dealing with multi-core CPU chips at a cost of slightly 1018 increased overhead in some places. If unsure say N here. 1019 1020config SCHED_MC_PRIO 1021 bool "CPU core priorities scheduler support" 1022 depends on SCHED_MC && CPU_SUP_INTEL 1023 select X86_INTEL_PSTATE 1024 select CPU_FREQ 1025 default y 1026 ---help--- 1027 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1028 core ordering determined at manufacturing time, which allows 1029 certain cores to reach higher turbo frequencies (when running 1030 single threaded workloads) than others. 1031 1032 Enabling this kernel feature teaches the scheduler about 1033 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1034 scheduler's CPU selection logic accordingly, so that higher 1035 overall system performance can be achieved. 1036 1037 This feature will have no effect on CPUs without this feature. 1038 1039 If unsure say Y here. 1040 1041config UP_LATE_INIT 1042 def_bool y 1043 depends on !SMP && X86_LOCAL_APIC 1044 1045config X86_UP_APIC 1046 bool "Local APIC support on uniprocessors" if !PCI_MSI 1047 default PCI_MSI 1048 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1049 ---help--- 1050 A local APIC (Advanced Programmable Interrupt Controller) is an 1051 integrated interrupt controller in the CPU. If you have a single-CPU 1052 system which has a processor with a local APIC, you can say Y here to 1053 enable and use it. If you say Y here even though your machine doesn't 1054 have a local APIC, then the kernel will still run with no slowdown at 1055 all. The local APIC supports CPU-generated self-interrupts (timer, 1056 performance counters), and the NMI watchdog which detects hard 1057 lockups. 1058 1059config X86_UP_IOAPIC 1060 bool "IO-APIC support on uniprocessors" 1061 depends on X86_UP_APIC 1062 ---help--- 1063 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1064 SMP-capable replacement for PC-style interrupt controllers. Most 1065 SMP systems and many recent uniprocessor systems have one. 1066 1067 If you have a single-CPU system with an IO-APIC, you can say Y here 1068 to use it. If you say Y here even though your machine doesn't have 1069 an IO-APIC, then the kernel will still run with no slowdown at all. 1070 1071config X86_LOCAL_APIC 1072 def_bool y 1073 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1074 select IRQ_DOMAIN_HIERARCHY 1075 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1076 1077config X86_IO_APIC 1078 def_bool y 1079 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1080 1081config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1082 bool "Reroute for broken boot IRQs" 1083 depends on X86_IO_APIC 1084 ---help--- 1085 This option enables a workaround that fixes a source of 1086 spurious interrupts. This is recommended when threaded 1087 interrupt handling is used on systems where the generation of 1088 superfluous "boot interrupts" cannot be disabled. 1089 1090 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1091 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1092 kernel does during interrupt handling). On chipsets where this 1093 boot IRQ generation cannot be disabled, this workaround keeps 1094 the original IRQ line masked so that only the equivalent "boot 1095 IRQ" is delivered to the CPUs. The workaround also tells the 1096 kernel to set up the IRQ handler on the boot IRQ line. In this 1097 way only one interrupt is delivered to the kernel. Otherwise 1098 the spurious second interrupt may cause the kernel to bring 1099 down (vital) interrupt lines. 1100 1101 Only affects "broken" chipsets. Interrupt sharing may be 1102 increased on these systems. 1103 1104config X86_MCE 1105 bool "Machine Check / overheating reporting" 1106 select GENERIC_ALLOCATOR 1107 default y 1108 ---help--- 1109 Machine Check support allows the processor to notify the 1110 kernel if it detects a problem (e.g. overheating, data corruption). 1111 The action the kernel takes depends on the severity of the problem, 1112 ranging from warning messages to halting the machine. 1113 1114config X86_MCELOG_LEGACY 1115 bool "Support for deprecated /dev/mcelog character device" 1116 depends on X86_MCE 1117 ---help--- 1118 Enable support for /dev/mcelog which is needed by the old mcelog 1119 userspace logging daemon. Consider switching to the new generation 1120 rasdaemon solution. 1121 1122config X86_MCE_INTEL 1123 def_bool y 1124 prompt "Intel MCE features" 1125 depends on X86_MCE && X86_LOCAL_APIC 1126 ---help--- 1127 Additional support for intel specific MCE features such as 1128 the thermal monitor. 1129 1130config X86_MCE_AMD 1131 def_bool y 1132 prompt "AMD MCE features" 1133 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1134 ---help--- 1135 Additional support for AMD specific MCE features such as 1136 the DRAM Error Threshold. 1137 1138config X86_ANCIENT_MCE 1139 bool "Support for old Pentium 5 / WinChip machine checks" 1140 depends on X86_32 && X86_MCE 1141 ---help--- 1142 Include support for machine check handling on old Pentium 5 or WinChip 1143 systems. These typically need to be enabled explicitly on the command 1144 line. 1145 1146config X86_MCE_THRESHOLD 1147 depends on X86_MCE_AMD || X86_MCE_INTEL 1148 def_bool y 1149 1150config X86_MCE_INJECT 1151 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1152 tristate "Machine check injector support" 1153 ---help--- 1154 Provide support for injecting machine checks for testing purposes. 1155 If you don't know what a machine check is and you don't do kernel 1156 QA it is safe to say n. 1157 1158config X86_THERMAL_VECTOR 1159 def_bool y 1160 depends on X86_MCE_INTEL 1161 1162source "arch/x86/events/Kconfig" 1163 1164config X86_LEGACY_VM86 1165 bool "Legacy VM86 support" 1166 depends on X86_32 1167 ---help--- 1168 This option allows user programs to put the CPU into V8086 1169 mode, which is an 80286-era approximation of 16-bit real mode. 1170 1171 Some very old versions of X and/or vbetool require this option 1172 for user mode setting. Similarly, DOSEMU will use it if 1173 available to accelerate real mode DOS programs. However, any 1174 recent version of DOSEMU, X, or vbetool should be fully 1175 functional even without kernel VM86 support, as they will all 1176 fall back to software emulation. Nevertheless, if you are using 1177 a 16-bit DOS program where 16-bit performance matters, vm86 1178 mode might be faster than emulation and you might want to 1179 enable this option. 1180 1181 Note that any app that works on a 64-bit kernel is unlikely to 1182 need this option, as 64-bit kernels don't, and can't, support 1183 V8086 mode. This option is also unrelated to 16-bit protected 1184 mode and is not needed to run most 16-bit programs under Wine. 1185 1186 Enabling this option increases the complexity of the kernel 1187 and slows down exception handling a tiny bit. 1188 1189 If unsure, say N here. 1190 1191config VM86 1192 bool 1193 default X86_LEGACY_VM86 1194 1195config X86_16BIT 1196 bool "Enable support for 16-bit segments" if EXPERT 1197 default y 1198 depends on MODIFY_LDT_SYSCALL 1199 ---help--- 1200 This option is required by programs like Wine to run 16-bit 1201 protected mode legacy code on x86 processors. Disabling 1202 this option saves about 300 bytes on i386, or around 6K text 1203 plus 16K runtime memory on x86-64, 1204 1205config X86_ESPFIX32 1206 def_bool y 1207 depends on X86_16BIT && X86_32 1208 1209config X86_ESPFIX64 1210 def_bool y 1211 depends on X86_16BIT && X86_64 1212 1213config X86_VSYSCALL_EMULATION 1214 bool "Enable vsyscall emulation" if EXPERT 1215 default y 1216 depends on X86_64 1217 ---help--- 1218 This enables emulation of the legacy vsyscall page. Disabling 1219 it is roughly equivalent to booting with vsyscall=none, except 1220 that it will also disable the helpful warning if a program 1221 tries to use a vsyscall. With this option set to N, offending 1222 programs will just segfault, citing addresses of the form 1223 0xffffffffff600?00. 1224 1225 This option is required by many programs built before 2013, and 1226 care should be used even with newer programs if set to N. 1227 1228 Disabling this option saves about 7K of kernel size and 1229 possibly 4K of additional runtime pagetable memory. 1230 1231config TOSHIBA 1232 tristate "Toshiba Laptop support" 1233 depends on X86_32 1234 ---help--- 1235 This adds a driver to safely access the System Management Mode of 1236 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1237 not work on models with a Phoenix BIOS. The System Management Mode 1238 is used to set the BIOS and power saving options on Toshiba portables. 1239 1240 For information on utilities to make use of this driver see the 1241 Toshiba Linux utilities web site at: 1242 <http://www.buzzard.org.uk/toshiba/>. 1243 1244 Say Y if you intend to run this kernel on a Toshiba portable. 1245 Say N otherwise. 1246 1247config I8K 1248 tristate "Dell i8k legacy laptop support" 1249 select HWMON 1250 select SENSORS_DELL_SMM 1251 ---help--- 1252 This option enables legacy /proc/i8k userspace interface in hwmon 1253 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1254 temperature and allows controlling fan speeds of Dell laptops via 1255 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1256 it reports also power and hotkey status. For fan speed control is 1257 needed userspace package i8kutils. 1258 1259 Say Y if you intend to run this kernel on old Dell laptops or want to 1260 use userspace package i8kutils. 1261 Say N otherwise. 1262 1263config X86_REBOOTFIXUPS 1264 bool "Enable X86 board specific fixups for reboot" 1265 depends on X86_32 1266 ---help--- 1267 This enables chipset and/or board specific fixups to be done 1268 in order to get reboot to work correctly. This is only needed on 1269 some combinations of hardware and BIOS. The symptom, for which 1270 this config is intended, is when reboot ends with a stalled/hung 1271 system. 1272 1273 Currently, the only fixup is for the Geode machines using 1274 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1275 1276 Say Y if you want to enable the fixup. Currently, it's safe to 1277 enable this option even if you don't need it. 1278 Say N otherwise. 1279 1280config MICROCODE 1281 bool "CPU microcode loading support" 1282 default y 1283 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1284 select FW_LOADER 1285 ---help--- 1286 If you say Y here, you will be able to update the microcode on 1287 Intel and AMD processors. The Intel support is for the IA32 family, 1288 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1289 AMD support is for families 0x10 and later. You will obviously need 1290 the actual microcode binary data itself which is not shipped with 1291 the Linux kernel. 1292 1293 The preferred method to load microcode from a detached initrd is described 1294 in Documentation/x86/microcode.txt. For that you need to enable 1295 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1296 initrd for microcode blobs. 1297 1298 In addition, you can build the microcode into the kernel. For that you 1299 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1300 config option. 1301 1302config MICROCODE_INTEL 1303 bool "Intel microcode loading support" 1304 depends on MICROCODE 1305 default MICROCODE 1306 select FW_LOADER 1307 ---help--- 1308 This options enables microcode patch loading support for Intel 1309 processors. 1310 1311 For the current Intel microcode data package go to 1312 <https://downloadcenter.intel.com> and search for 1313 'Linux Processor Microcode Data File'. 1314 1315config MICROCODE_AMD 1316 bool "AMD microcode loading support" 1317 depends on MICROCODE 1318 select FW_LOADER 1319 ---help--- 1320 If you select this option, microcode patch loading support for AMD 1321 processors will be enabled. 1322 1323config MICROCODE_OLD_INTERFACE 1324 def_bool y 1325 depends on MICROCODE 1326 1327config X86_MSR 1328 tristate "/dev/cpu/*/msr - Model-specific register support" 1329 ---help--- 1330 This device gives privileged processes access to the x86 1331 Model-Specific Registers (MSRs). It is a character device with 1332 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1333 MSR accesses are directed to a specific CPU on multi-processor 1334 systems. 1335 1336config X86_CPUID 1337 tristate "/dev/cpu/*/cpuid - CPU information support" 1338 ---help--- 1339 This device gives processes access to the x86 CPUID instruction to 1340 be executed on a specific processor. It is a character device 1341 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1342 /dev/cpu/31/cpuid. 1343 1344choice 1345 prompt "High Memory Support" 1346 default HIGHMEM4G 1347 depends on X86_32 1348 1349config NOHIGHMEM 1350 bool "off" 1351 ---help--- 1352 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1353 However, the address space of 32-bit x86 processors is only 4 1354 Gigabytes large. That means that, if you have a large amount of 1355 physical memory, not all of it can be "permanently mapped" by the 1356 kernel. The physical memory that's not permanently mapped is called 1357 "high memory". 1358 1359 If you are compiling a kernel which will never run on a machine with 1360 more than 1 Gigabyte total physical RAM, answer "off" here (default 1361 choice and suitable for most users). This will result in a "3GB/1GB" 1362 split: 3GB are mapped so that each process sees a 3GB virtual memory 1363 space and the remaining part of the 4GB virtual memory space is used 1364 by the kernel to permanently map as much physical memory as 1365 possible. 1366 1367 If the machine has between 1 and 4 Gigabytes physical RAM, then 1368 answer "4GB" here. 1369 1370 If more than 4 Gigabytes is used then answer "64GB" here. This 1371 selection turns Intel PAE (Physical Address Extension) mode on. 1372 PAE implements 3-level paging on IA32 processors. PAE is fully 1373 supported by Linux, PAE mode is implemented on all recent Intel 1374 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1375 then the kernel will not boot on CPUs that don't support PAE! 1376 1377 The actual amount of total physical memory will either be 1378 auto detected or can be forced by using a kernel command line option 1379 such as "mem=256M". (Try "man bootparam" or see the documentation of 1380 your boot loader (lilo or loadlin) about how to pass options to the 1381 kernel at boot time.) 1382 1383 If unsure, say "off". 1384 1385config HIGHMEM4G 1386 bool "4GB" 1387 ---help--- 1388 Select this if you have a 32-bit processor and between 1 and 4 1389 gigabytes of physical RAM. 1390 1391config HIGHMEM64G 1392 bool "64GB" 1393 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1394 select X86_PAE 1395 ---help--- 1396 Select this if you have a 32-bit processor and more than 4 1397 gigabytes of physical RAM. 1398 1399endchoice 1400 1401choice 1402 prompt "Memory split" if EXPERT 1403 default VMSPLIT_3G 1404 depends on X86_32 1405 ---help--- 1406 Select the desired split between kernel and user memory. 1407 1408 If the address range available to the kernel is less than the 1409 physical memory installed, the remaining memory will be available 1410 as "high memory". Accessing high memory is a little more costly 1411 than low memory, as it needs to be mapped into the kernel first. 1412 Note that increasing the kernel address space limits the range 1413 available to user programs, making the address space there 1414 tighter. Selecting anything other than the default 3G/1G split 1415 will also likely make your kernel incompatible with binary-only 1416 kernel modules. 1417 1418 If you are not absolutely sure what you are doing, leave this 1419 option alone! 1420 1421 config VMSPLIT_3G 1422 bool "3G/1G user/kernel split" 1423 config VMSPLIT_3G_OPT 1424 depends on !X86_PAE 1425 bool "3G/1G user/kernel split (for full 1G low memory)" 1426 config VMSPLIT_2G 1427 bool "2G/2G user/kernel split" 1428 config VMSPLIT_2G_OPT 1429 depends on !X86_PAE 1430 bool "2G/2G user/kernel split (for full 2G low memory)" 1431 config VMSPLIT_1G 1432 bool "1G/3G user/kernel split" 1433endchoice 1434 1435config PAGE_OFFSET 1436 hex 1437 default 0xB0000000 if VMSPLIT_3G_OPT 1438 default 0x80000000 if VMSPLIT_2G 1439 default 0x78000000 if VMSPLIT_2G_OPT 1440 default 0x40000000 if VMSPLIT_1G 1441 default 0xC0000000 1442 depends on X86_32 1443 1444config HIGHMEM 1445 def_bool y 1446 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1447 1448config X86_PAE 1449 bool "PAE (Physical Address Extension) Support" 1450 depends on X86_32 && !HIGHMEM4G 1451 select PHYS_ADDR_T_64BIT 1452 select SWIOTLB 1453 ---help--- 1454 PAE is required for NX support, and furthermore enables 1455 larger swapspace support for non-overcommit purposes. It 1456 has the cost of more pagetable lookup overhead, and also 1457 consumes more pagetable space per process. 1458 1459config X86_5LEVEL 1460 bool "Enable 5-level page tables support" 1461 select DYNAMIC_MEMORY_LAYOUT 1462 select SPARSEMEM_VMEMMAP 1463 depends on X86_64 1464 ---help--- 1465 5-level paging enables access to larger address space: 1466 upto 128 PiB of virtual address space and 4 PiB of 1467 physical address space. 1468 1469 It will be supported by future Intel CPUs. 1470 1471 A kernel with the option enabled can be booted on machines that 1472 support 4- or 5-level paging. 1473 1474 See Documentation/x86/x86_64/5level-paging.txt for more 1475 information. 1476 1477 Say N if unsure. 1478 1479config X86_DIRECT_GBPAGES 1480 def_bool y 1481 depends on X86_64 && !DEBUG_PAGEALLOC 1482 ---help--- 1483 Certain kernel features effectively disable kernel 1484 linear 1 GB mappings (even if the CPU otherwise 1485 supports them), so don't confuse the user by printing 1486 that we have them enabled. 1487 1488config X86_CPA_STATISTICS 1489 bool "Enable statistic for Change Page Attribute" 1490 depends on DEBUG_FS 1491 ---help--- 1492 Expose statistics about the Change Page Attribute mechanims, which 1493 helps to determine the effectivness of preserving large and huge 1494 page mappings when mapping protections are changed. 1495 1496config ARCH_HAS_MEM_ENCRYPT 1497 def_bool y 1498 1499config AMD_MEM_ENCRYPT 1500 bool "AMD Secure Memory Encryption (SME) support" 1501 depends on X86_64 && CPU_SUP_AMD 1502 select DYNAMIC_PHYSICAL_MASK 1503 ---help--- 1504 Say yes to enable support for the encryption of system memory. 1505 This requires an AMD processor that supports Secure Memory 1506 Encryption (SME). 1507 1508config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1509 bool "Activate AMD Secure Memory Encryption (SME) by default" 1510 default y 1511 depends on AMD_MEM_ENCRYPT 1512 ---help--- 1513 Say yes to have system memory encrypted by default if running on 1514 an AMD processor that supports Secure Memory Encryption (SME). 1515 1516 If set to Y, then the encryption of system memory can be 1517 deactivated with the mem_encrypt=off command line option. 1518 1519 If set to N, then the encryption of system memory can be 1520 activated with the mem_encrypt=on command line option. 1521 1522config ARCH_USE_MEMREMAP_PROT 1523 def_bool y 1524 depends on AMD_MEM_ENCRYPT 1525 1526# Common NUMA Features 1527config NUMA 1528 bool "Numa Memory Allocation and Scheduler Support" 1529 depends on SMP 1530 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1531 default y if X86_BIGSMP 1532 ---help--- 1533 Enable NUMA (Non Uniform Memory Access) support. 1534 1535 The kernel will try to allocate memory used by a CPU on the 1536 local memory controller of the CPU and add some more 1537 NUMA awareness to the kernel. 1538 1539 For 64-bit this is recommended if the system is Intel Core i7 1540 (or later), AMD Opteron, or EM64T NUMA. 1541 1542 For 32-bit this is only needed if you boot a 32-bit 1543 kernel on a 64-bit NUMA platform. 1544 1545 Otherwise, you should say N. 1546 1547config AMD_NUMA 1548 def_bool y 1549 prompt "Old style AMD Opteron NUMA detection" 1550 depends on X86_64 && NUMA && PCI 1551 ---help--- 1552 Enable AMD NUMA node topology detection. You should say Y here if 1553 you have a multi processor AMD system. This uses an old method to 1554 read the NUMA configuration directly from the builtin Northbridge 1555 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1556 which also takes priority if both are compiled in. 1557 1558config X86_64_ACPI_NUMA 1559 def_bool y 1560 prompt "ACPI NUMA detection" 1561 depends on X86_64 && NUMA && ACPI && PCI 1562 select ACPI_NUMA 1563 ---help--- 1564 Enable ACPI SRAT based node topology detection. 1565 1566# Some NUMA nodes have memory ranges that span 1567# other nodes. Even though a pfn is valid and 1568# between a node's start and end pfns, it may not 1569# reside on that node. See memmap_init_zone() 1570# for details. 1571config NODES_SPAN_OTHER_NODES 1572 def_bool y 1573 depends on X86_64_ACPI_NUMA 1574 1575config NUMA_EMU 1576 bool "NUMA emulation" 1577 depends on NUMA 1578 ---help--- 1579 Enable NUMA emulation. A flat machine will be split 1580 into virtual nodes when booted with "numa=fake=N", where N is the 1581 number of nodes. This is only useful for debugging. 1582 1583config NODES_SHIFT 1584 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1585 range 1 10 1586 default "10" if MAXSMP 1587 default "6" if X86_64 1588 default "3" 1589 depends on NEED_MULTIPLE_NODES 1590 ---help--- 1591 Specify the maximum number of NUMA Nodes available on the target 1592 system. Increases memory reserved to accommodate various tables. 1593 1594config ARCH_HAVE_MEMORY_PRESENT 1595 def_bool y 1596 depends on X86_32 && DISCONTIGMEM 1597 1598config ARCH_FLATMEM_ENABLE 1599 def_bool y 1600 depends on X86_32 && !NUMA 1601 1602config ARCH_DISCONTIGMEM_ENABLE 1603 def_bool y 1604 depends on NUMA && X86_32 1605 1606config ARCH_DISCONTIGMEM_DEFAULT 1607 def_bool y 1608 depends on NUMA && X86_32 1609 1610config ARCH_SPARSEMEM_ENABLE 1611 def_bool y 1612 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1613 select SPARSEMEM_STATIC if X86_32 1614 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1615 1616config ARCH_SPARSEMEM_DEFAULT 1617 def_bool y 1618 depends on X86_64 1619 1620config ARCH_SELECT_MEMORY_MODEL 1621 def_bool y 1622 depends on ARCH_SPARSEMEM_ENABLE 1623 1624config ARCH_MEMORY_PROBE 1625 bool "Enable sysfs memory/probe interface" 1626 depends on X86_64 && MEMORY_HOTPLUG 1627 help 1628 This option enables a sysfs memory/probe interface for testing. 1629 See Documentation/memory-hotplug.txt for more information. 1630 If you are unsure how to answer this question, answer N. 1631 1632config ARCH_PROC_KCORE_TEXT 1633 def_bool y 1634 depends on X86_64 && PROC_KCORE 1635 1636config ILLEGAL_POINTER_VALUE 1637 hex 1638 default 0 if X86_32 1639 default 0xdead000000000000 if X86_64 1640 1641config X86_PMEM_LEGACY_DEVICE 1642 bool 1643 1644config X86_PMEM_LEGACY 1645 tristate "Support non-standard NVDIMMs and ADR protected memory" 1646 depends on PHYS_ADDR_T_64BIT 1647 depends on BLK_DEV 1648 select X86_PMEM_LEGACY_DEVICE 1649 select LIBNVDIMM 1650 help 1651 Treat memory marked using the non-standard e820 type of 12 as used 1652 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1653 The kernel will offer these regions to the 'pmem' driver so 1654 they can be used for persistent storage. 1655 1656 Say Y if unsure. 1657 1658config HIGHPTE 1659 bool "Allocate 3rd-level pagetables from highmem" 1660 depends on HIGHMEM 1661 ---help--- 1662 The VM uses one page table entry for each page of physical memory. 1663 For systems with a lot of RAM, this can be wasteful of precious 1664 low memory. Setting this option will put user-space page table 1665 entries in high memory. 1666 1667config X86_CHECK_BIOS_CORRUPTION 1668 bool "Check for low memory corruption" 1669 ---help--- 1670 Periodically check for memory corruption in low memory, which 1671 is suspected to be caused by BIOS. Even when enabled in the 1672 configuration, it is disabled at runtime. Enable it by 1673 setting "memory_corruption_check=1" on the kernel command 1674 line. By default it scans the low 64k of memory every 60 1675 seconds; see the memory_corruption_check_size and 1676 memory_corruption_check_period parameters in 1677 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1678 1679 When enabled with the default parameters, this option has 1680 almost no overhead, as it reserves a relatively small amount 1681 of memory and scans it infrequently. It both detects corruption 1682 and prevents it from affecting the running system. 1683 1684 It is, however, intended as a diagnostic tool; if repeatable 1685 BIOS-originated corruption always affects the same memory, 1686 you can use memmap= to prevent the kernel from using that 1687 memory. 1688 1689config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1690 bool "Set the default setting of memory_corruption_check" 1691 depends on X86_CHECK_BIOS_CORRUPTION 1692 default y 1693 ---help--- 1694 Set whether the default state of memory_corruption_check is 1695 on or off. 1696 1697config X86_RESERVE_LOW 1698 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1699 default 64 1700 range 4 640 1701 ---help--- 1702 Specify the amount of low memory to reserve for the BIOS. 1703 1704 The first page contains BIOS data structures that the kernel 1705 must not use, so that page must always be reserved. 1706 1707 By default we reserve the first 64K of physical RAM, as a 1708 number of BIOSes are known to corrupt that memory range 1709 during events such as suspend/resume or monitor cable 1710 insertion, so it must not be used by the kernel. 1711 1712 You can set this to 4 if you are absolutely sure that you 1713 trust the BIOS to get all its memory reservations and usages 1714 right. If you know your BIOS have problems beyond the 1715 default 64K area, you can set this to 640 to avoid using the 1716 entire low memory range. 1717 1718 If you have doubts about the BIOS (e.g. suspend/resume does 1719 not work or there's kernel crashes after certain hardware 1720 hotplug events) then you might want to enable 1721 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1722 typical corruption patterns. 1723 1724 Leave this to the default value of 64 if you are unsure. 1725 1726config MATH_EMULATION 1727 bool 1728 depends on MODIFY_LDT_SYSCALL 1729 prompt "Math emulation" if X86_32 1730 ---help--- 1731 Linux can emulate a math coprocessor (used for floating point 1732 operations) if you don't have one. 486DX and Pentium processors have 1733 a math coprocessor built in, 486SX and 386 do not, unless you added 1734 a 487DX or 387, respectively. (The messages during boot time can 1735 give you some hints here ["man dmesg"].) Everyone needs either a 1736 coprocessor or this emulation. 1737 1738 If you don't have a math coprocessor, you need to say Y here; if you 1739 say Y here even though you have a coprocessor, the coprocessor will 1740 be used nevertheless. (This behavior can be changed with the kernel 1741 command line option "no387", which comes handy if your coprocessor 1742 is broken. Try "man bootparam" or see the documentation of your boot 1743 loader (lilo or loadlin) about how to pass options to the kernel at 1744 boot time.) This means that it is a good idea to say Y here if you 1745 intend to use this kernel on different machines. 1746 1747 More information about the internals of the Linux math coprocessor 1748 emulation can be found in <file:arch/x86/math-emu/README>. 1749 1750 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1751 kernel, it won't hurt. 1752 1753config MTRR 1754 def_bool y 1755 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1756 ---help--- 1757 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1758 the Memory Type Range Registers (MTRRs) may be used to control 1759 processor access to memory ranges. This is most useful if you have 1760 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1761 allows bus write transfers to be combined into a larger transfer 1762 before bursting over the PCI/AGP bus. This can increase performance 1763 of image write operations 2.5 times or more. Saying Y here creates a 1764 /proc/mtrr file which may be used to manipulate your processor's 1765 MTRRs. Typically the X server should use this. 1766 1767 This code has a reasonably generic interface so that similar 1768 control registers on other processors can be easily supported 1769 as well: 1770 1771 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1772 Registers (ARRs) which provide a similar functionality to MTRRs. For 1773 these, the ARRs are used to emulate the MTRRs. 1774 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1775 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1776 write-combining. All of these processors are supported by this code 1777 and it makes sense to say Y here if you have one of them. 1778 1779 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1780 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1781 can lead to all sorts of problems, so it's good to say Y here. 1782 1783 You can safely say Y even if your machine doesn't have MTRRs, you'll 1784 just add about 9 KB to your kernel. 1785 1786 See <file:Documentation/x86/mtrr.txt> for more information. 1787 1788config MTRR_SANITIZER 1789 def_bool y 1790 prompt "MTRR cleanup support" 1791 depends on MTRR 1792 ---help--- 1793 Convert MTRR layout from continuous to discrete, so X drivers can 1794 add writeback entries. 1795 1796 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1797 The largest mtrr entry size for a continuous block can be set with 1798 mtrr_chunk_size. 1799 1800 If unsure, say Y. 1801 1802config MTRR_SANITIZER_ENABLE_DEFAULT 1803 int "MTRR cleanup enable value (0-1)" 1804 range 0 1 1805 default "0" 1806 depends on MTRR_SANITIZER 1807 ---help--- 1808 Enable mtrr cleanup default value 1809 1810config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1811 int "MTRR cleanup spare reg num (0-7)" 1812 range 0 7 1813 default "1" 1814 depends on MTRR_SANITIZER 1815 ---help--- 1816 mtrr cleanup spare entries default, it can be changed via 1817 mtrr_spare_reg_nr=N on the kernel command line. 1818 1819config X86_PAT 1820 def_bool y 1821 prompt "x86 PAT support" if EXPERT 1822 depends on MTRR 1823 ---help--- 1824 Use PAT attributes to setup page level cache control. 1825 1826 PATs are the modern equivalents of MTRRs and are much more 1827 flexible than MTRRs. 1828 1829 Say N here if you see bootup problems (boot crash, boot hang, 1830 spontaneous reboots) or a non-working video driver. 1831 1832 If unsure, say Y. 1833 1834config ARCH_USES_PG_UNCACHED 1835 def_bool y 1836 depends on X86_PAT 1837 1838config ARCH_RANDOM 1839 def_bool y 1840 prompt "x86 architectural random number generator" if EXPERT 1841 ---help--- 1842 Enable the x86 architectural RDRAND instruction 1843 (Intel Bull Mountain technology) to generate random numbers. 1844 If supported, this is a high bandwidth, cryptographically 1845 secure hardware random number generator. 1846 1847config X86_SMAP 1848 def_bool y 1849 prompt "Supervisor Mode Access Prevention" if EXPERT 1850 ---help--- 1851 Supervisor Mode Access Prevention (SMAP) is a security 1852 feature in newer Intel processors. There is a small 1853 performance cost if this enabled and turned on; there is 1854 also a small increase in the kernel size if this is enabled. 1855 1856 If unsure, say Y. 1857 1858config X86_INTEL_UMIP 1859 def_bool y 1860 depends on CPU_SUP_INTEL 1861 prompt "Intel User Mode Instruction Prevention" if EXPERT 1862 ---help--- 1863 The User Mode Instruction Prevention (UMIP) is a security 1864 feature in newer Intel processors. If enabled, a general 1865 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1866 or STR instructions are executed in user mode. These instructions 1867 unnecessarily expose information about the hardware state. 1868 1869 The vast majority of applications do not use these instructions. 1870 For the very few that do, software emulation is provided in 1871 specific cases in protected and virtual-8086 modes. Emulated 1872 results are dummy. 1873 1874config X86_INTEL_MPX 1875 prompt "Intel MPX (Memory Protection Extensions)" 1876 def_bool n 1877 # Note: only available in 64-bit mode due to VMA flags shortage 1878 depends on CPU_SUP_INTEL && X86_64 1879 select ARCH_USES_HIGH_VMA_FLAGS 1880 ---help--- 1881 MPX provides hardware features that can be used in 1882 conjunction with compiler-instrumented code to check 1883 memory references. It is designed to detect buffer 1884 overflow or underflow bugs. 1885 1886 This option enables running applications which are 1887 instrumented or otherwise use MPX. It does not use MPX 1888 itself inside the kernel or to protect the kernel 1889 against bad memory references. 1890 1891 Enabling this option will make the kernel larger: 1892 ~8k of kernel text and 36 bytes of data on a 64-bit 1893 defconfig. It adds a long to the 'mm_struct' which 1894 will increase the kernel memory overhead of each 1895 process and adds some branches to paths used during 1896 exec() and munmap(). 1897 1898 For details, see Documentation/x86/intel_mpx.txt 1899 1900 If unsure, say N. 1901 1902config X86_INTEL_MEMORY_PROTECTION_KEYS 1903 prompt "Intel Memory Protection Keys" 1904 def_bool y 1905 # Note: only available in 64-bit mode 1906 depends on CPU_SUP_INTEL && X86_64 1907 select ARCH_USES_HIGH_VMA_FLAGS 1908 select ARCH_HAS_PKEYS 1909 ---help--- 1910 Memory Protection Keys provides a mechanism for enforcing 1911 page-based protections, but without requiring modification of the 1912 page tables when an application changes protection domains. 1913 1914 For details, see Documentation/x86/protection-keys.txt 1915 1916 If unsure, say y. 1917 1918config EFI 1919 bool "EFI runtime service support" 1920 depends on ACPI 1921 select UCS2_STRING 1922 select EFI_RUNTIME_WRAPPERS 1923 ---help--- 1924 This enables the kernel to use EFI runtime services that are 1925 available (such as the EFI variable services). 1926 1927 This option is only useful on systems that have EFI firmware. 1928 In addition, you should use the latest ELILO loader available 1929 at <http://elilo.sourceforge.net> in order to take advantage 1930 of EFI runtime services. However, even with this option, the 1931 resultant kernel should continue to boot on existing non-EFI 1932 platforms. 1933 1934config EFI_STUB 1935 bool "EFI stub support" 1936 depends on EFI && !X86_USE_3DNOW 1937 select RELOCATABLE 1938 ---help--- 1939 This kernel feature allows a bzImage to be loaded directly 1940 by EFI firmware without the use of a bootloader. 1941 1942 See Documentation/efi-stub.txt for more information. 1943 1944config EFI_MIXED 1945 bool "EFI mixed-mode support" 1946 depends on EFI_STUB && X86_64 1947 ---help--- 1948 Enabling this feature allows a 64-bit kernel to be booted 1949 on a 32-bit firmware, provided that your CPU supports 64-bit 1950 mode. 1951 1952 Note that it is not possible to boot a mixed-mode enabled 1953 kernel via the EFI boot stub - a bootloader that supports 1954 the EFI handover protocol must be used. 1955 1956 If unsure, say N. 1957 1958config SECCOMP 1959 def_bool y 1960 prompt "Enable seccomp to safely compute untrusted bytecode" 1961 ---help--- 1962 This kernel feature is useful for number crunching applications 1963 that may need to compute untrusted bytecode during their 1964 execution. By using pipes or other transports made available to 1965 the process as file descriptors supporting the read/write 1966 syscalls, it's possible to isolate those applications in 1967 their own address space using seccomp. Once seccomp is 1968 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1969 and the task is only allowed to execute a few safe syscalls 1970 defined by each seccomp mode. 1971 1972 If unsure, say Y. Only embedded should say N here. 1973 1974source kernel/Kconfig.hz 1975 1976config KEXEC 1977 bool "kexec system call" 1978 select KEXEC_CORE 1979 ---help--- 1980 kexec is a system call that implements the ability to shutdown your 1981 current kernel, and to start another kernel. It is like a reboot 1982 but it is independent of the system firmware. And like a reboot 1983 you can start any kernel with it, not just Linux. 1984 1985 The name comes from the similarity to the exec system call. 1986 1987 It is an ongoing process to be certain the hardware in a machine 1988 is properly shutdown, so do not be surprised if this code does not 1989 initially work for you. As of this writing the exact hardware 1990 interface is strongly in flux, so no good recommendation can be 1991 made. 1992 1993config KEXEC_FILE 1994 bool "kexec file based system call" 1995 select KEXEC_CORE 1996 select BUILD_BIN2C 1997 depends on X86_64 1998 depends on CRYPTO=y 1999 depends on CRYPTO_SHA256=y 2000 ---help--- 2001 This is new version of kexec system call. This system call is 2002 file based and takes file descriptors as system call argument 2003 for kernel and initramfs as opposed to list of segments as 2004 accepted by previous system call. 2005 2006config ARCH_HAS_KEXEC_PURGATORY 2007 def_bool KEXEC_FILE 2008 2009config KEXEC_VERIFY_SIG 2010 bool "Verify kernel signature during kexec_file_load() syscall" 2011 depends on KEXEC_FILE 2012 ---help--- 2013 This option makes kernel signature verification mandatory for 2014 the kexec_file_load() syscall. 2015 2016 In addition to that option, you need to enable signature 2017 verification for the corresponding kernel image type being 2018 loaded in order for this to work. 2019 2020config KEXEC_BZIMAGE_VERIFY_SIG 2021 bool "Enable bzImage signature verification support" 2022 depends on KEXEC_VERIFY_SIG 2023 depends on SIGNED_PE_FILE_VERIFICATION 2024 select SYSTEM_TRUSTED_KEYRING 2025 ---help--- 2026 Enable bzImage signature verification support. 2027 2028config CRASH_DUMP 2029 bool "kernel crash dumps" 2030 depends on X86_64 || (X86_32 && HIGHMEM) 2031 ---help--- 2032 Generate crash dump after being started by kexec. 2033 This should be normally only set in special crash dump kernels 2034 which are loaded in the main kernel with kexec-tools into 2035 a specially reserved region and then later executed after 2036 a crash by kdump/kexec. The crash dump kernel must be compiled 2037 to a memory address not used by the main kernel or BIOS using 2038 PHYSICAL_START, or it must be built as a relocatable image 2039 (CONFIG_RELOCATABLE=y). 2040 For more details see Documentation/kdump/kdump.txt 2041 2042config KEXEC_JUMP 2043 bool "kexec jump" 2044 depends on KEXEC && HIBERNATION 2045 ---help--- 2046 Jump between original kernel and kexeced kernel and invoke 2047 code in physical address mode via KEXEC 2048 2049config PHYSICAL_START 2050 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2051 default "0x1000000" 2052 ---help--- 2053 This gives the physical address where the kernel is loaded. 2054 2055 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2056 bzImage will decompress itself to above physical address and 2057 run from there. Otherwise, bzImage will run from the address where 2058 it has been loaded by the boot loader and will ignore above physical 2059 address. 2060 2061 In normal kdump cases one does not have to set/change this option 2062 as now bzImage can be compiled as a completely relocatable image 2063 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2064 address. This option is mainly useful for the folks who don't want 2065 to use a bzImage for capturing the crash dump and want to use a 2066 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2067 to be specifically compiled to run from a specific memory area 2068 (normally a reserved region) and this option comes handy. 2069 2070 So if you are using bzImage for capturing the crash dump, 2071 leave the value here unchanged to 0x1000000 and set 2072 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2073 for capturing the crash dump change this value to start of 2074 the reserved region. In other words, it can be set based on 2075 the "X" value as specified in the "crashkernel=YM@XM" 2076 command line boot parameter passed to the panic-ed 2077 kernel. Please take a look at Documentation/kdump/kdump.txt 2078 for more details about crash dumps. 2079 2080 Usage of bzImage for capturing the crash dump is recommended as 2081 one does not have to build two kernels. Same kernel can be used 2082 as production kernel and capture kernel. Above option should have 2083 gone away after relocatable bzImage support is introduced. But it 2084 is present because there are users out there who continue to use 2085 vmlinux for dump capture. This option should go away down the 2086 line. 2087 2088 Don't change this unless you know what you are doing. 2089 2090config RELOCATABLE 2091 bool "Build a relocatable kernel" 2092 default y 2093 ---help--- 2094 This builds a kernel image that retains relocation information 2095 so it can be loaded someplace besides the default 1MB. 2096 The relocations tend to make the kernel binary about 10% larger, 2097 but are discarded at runtime. 2098 2099 One use is for the kexec on panic case where the recovery kernel 2100 must live at a different physical address than the primary 2101 kernel. 2102 2103 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2104 it has been loaded at and the compile time physical address 2105 (CONFIG_PHYSICAL_START) is used as the minimum location. 2106 2107config RANDOMIZE_BASE 2108 bool "Randomize the address of the kernel image (KASLR)" 2109 depends on RELOCATABLE 2110 default y 2111 ---help--- 2112 In support of Kernel Address Space Layout Randomization (KASLR), 2113 this randomizes the physical address at which the kernel image 2114 is decompressed and the virtual address where the kernel 2115 image is mapped, as a security feature that deters exploit 2116 attempts relying on knowledge of the location of kernel 2117 code internals. 2118 2119 On 64-bit, the kernel physical and virtual addresses are 2120 randomized separately. The physical address will be anywhere 2121 between 16MB and the top of physical memory (up to 64TB). The 2122 virtual address will be randomized from 16MB up to 1GB (9 bits 2123 of entropy). Note that this also reduces the memory space 2124 available to kernel modules from 1.5GB to 1GB. 2125 2126 On 32-bit, the kernel physical and virtual addresses are 2127 randomized together. They will be randomized from 16MB up to 2128 512MB (8 bits of entropy). 2129 2130 Entropy is generated using the RDRAND instruction if it is 2131 supported. If RDTSC is supported, its value is mixed into 2132 the entropy pool as well. If neither RDRAND nor RDTSC are 2133 supported, then entropy is read from the i8254 timer. The 2134 usable entropy is limited by the kernel being built using 2135 2GB addressing, and that PHYSICAL_ALIGN must be at a 2136 minimum of 2MB. As a result, only 10 bits of entropy are 2137 theoretically possible, but the implementations are further 2138 limited due to memory layouts. 2139 2140 If unsure, say Y. 2141 2142# Relocation on x86 needs some additional build support 2143config X86_NEED_RELOCS 2144 def_bool y 2145 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2146 2147config PHYSICAL_ALIGN 2148 hex "Alignment value to which kernel should be aligned" 2149 default "0x200000" 2150 range 0x2000 0x1000000 if X86_32 2151 range 0x200000 0x1000000 if X86_64 2152 ---help--- 2153 This value puts the alignment restrictions on physical address 2154 where kernel is loaded and run from. Kernel is compiled for an 2155 address which meets above alignment restriction. 2156 2157 If bootloader loads the kernel at a non-aligned address and 2158 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2159 address aligned to above value and run from there. 2160 2161 If bootloader loads the kernel at a non-aligned address and 2162 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2163 load address and decompress itself to the address it has been 2164 compiled for and run from there. The address for which kernel is 2165 compiled already meets above alignment restrictions. Hence the 2166 end result is that kernel runs from a physical address meeting 2167 above alignment restrictions. 2168 2169 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2170 this value must be a multiple of 0x200000. 2171 2172 Don't change this unless you know what you are doing. 2173 2174config DYNAMIC_MEMORY_LAYOUT 2175 bool 2176 ---help--- 2177 This option makes base addresses of vmalloc and vmemmap as well as 2178 __PAGE_OFFSET movable during boot. 2179 2180config RANDOMIZE_MEMORY 2181 bool "Randomize the kernel memory sections" 2182 depends on X86_64 2183 depends on RANDOMIZE_BASE 2184 select DYNAMIC_MEMORY_LAYOUT 2185 default RANDOMIZE_BASE 2186 ---help--- 2187 Randomizes the base virtual address of kernel memory sections 2188 (physical memory mapping, vmalloc & vmemmap). This security feature 2189 makes exploits relying on predictable memory locations less reliable. 2190 2191 The order of allocations remains unchanged. Entropy is generated in 2192 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2193 configuration have in average 30,000 different possible virtual 2194 addresses for each memory section. 2195 2196 If unsure, say Y. 2197 2198config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2199 hex "Physical memory mapping padding" if EXPERT 2200 depends on RANDOMIZE_MEMORY 2201 default "0xa" if MEMORY_HOTPLUG 2202 default "0x0" 2203 range 0x1 0x40 if MEMORY_HOTPLUG 2204 range 0x0 0x40 2205 ---help--- 2206 Define the padding in terabytes added to the existing physical 2207 memory size during kernel memory randomization. It is useful 2208 for memory hotplug support but reduces the entropy available for 2209 address randomization. 2210 2211 If unsure, leave at the default value. 2212 2213config HOTPLUG_CPU 2214 bool "Support for hot-pluggable CPUs" 2215 depends on SMP 2216 ---help--- 2217 Say Y here to allow turning CPUs off and on. CPUs can be 2218 controlled through /sys/devices/system/cpu. 2219 ( Note: power management support will enable this option 2220 automatically on SMP systems. ) 2221 Say N if you want to disable CPU hotplug. 2222 2223config BOOTPARAM_HOTPLUG_CPU0 2224 bool "Set default setting of cpu0_hotpluggable" 2225 depends on HOTPLUG_CPU 2226 ---help--- 2227 Set whether default state of cpu0_hotpluggable is on or off. 2228 2229 Say Y here to enable CPU0 hotplug by default. If this switch 2230 is turned on, there is no need to give cpu0_hotplug kernel 2231 parameter and the CPU0 hotplug feature is enabled by default. 2232 2233 Please note: there are two known CPU0 dependencies if you want 2234 to enable the CPU0 hotplug feature either by this switch or by 2235 cpu0_hotplug kernel parameter. 2236 2237 First, resume from hibernate or suspend always starts from CPU0. 2238 So hibernate and suspend are prevented if CPU0 is offline. 2239 2240 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2241 offline if any interrupt can not migrate out of CPU0. There may 2242 be other CPU0 dependencies. 2243 2244 Please make sure the dependencies are under your control before 2245 you enable this feature. 2246 2247 Say N if you don't want to enable CPU0 hotplug feature by default. 2248 You still can enable the CPU0 hotplug feature at boot by kernel 2249 parameter cpu0_hotplug. 2250 2251config DEBUG_HOTPLUG_CPU0 2252 def_bool n 2253 prompt "Debug CPU0 hotplug" 2254 depends on HOTPLUG_CPU 2255 ---help--- 2256 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2257 soon as possible and boots up userspace with CPU0 offlined. User 2258 can online CPU0 back after boot time. 2259 2260 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2261 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2262 compilation or giving cpu0_hotplug kernel parameter at boot. 2263 2264 If unsure, say N. 2265 2266config COMPAT_VDSO 2267 def_bool n 2268 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2269 depends on COMPAT_32 2270 ---help--- 2271 Certain buggy versions of glibc will crash if they are 2272 presented with a 32-bit vDSO that is not mapped at the address 2273 indicated in its segment table. 2274 2275 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2276 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2277 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2278 the only released version with the bug, but OpenSUSE 9 2279 contains a buggy "glibc 2.3.2". 2280 2281 The symptom of the bug is that everything crashes on startup, saying: 2282 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2283 2284 Saying Y here changes the default value of the vdso32 boot 2285 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2286 This works around the glibc bug but hurts performance. 2287 2288 If unsure, say N: if you are compiling your own kernel, you 2289 are unlikely to be using a buggy version of glibc. 2290 2291choice 2292 prompt "vsyscall table for legacy applications" 2293 depends on X86_64 2294 default LEGACY_VSYSCALL_EMULATE 2295 help 2296 Legacy user code that does not know how to find the vDSO expects 2297 to be able to issue three syscalls by calling fixed addresses in 2298 kernel space. Since this location is not randomized with ASLR, 2299 it can be used to assist security vulnerability exploitation. 2300 2301 This setting can be changed at boot time via the kernel command 2302 line parameter vsyscall=[emulate|none]. 2303 2304 On a system with recent enough glibc (2.14 or newer) and no 2305 static binaries, you can say None without a performance penalty 2306 to improve security. 2307 2308 If unsure, select "Emulate". 2309 2310 config LEGACY_VSYSCALL_EMULATE 2311 bool "Emulate" 2312 help 2313 The kernel traps and emulates calls into the fixed 2314 vsyscall address mapping. This makes the mapping 2315 non-executable, but it still contains known contents, 2316 which could be used in certain rare security vulnerability 2317 exploits. This configuration is recommended when userspace 2318 still uses the vsyscall area. 2319 2320 config LEGACY_VSYSCALL_NONE 2321 bool "None" 2322 help 2323 There will be no vsyscall mapping at all. This will 2324 eliminate any risk of ASLR bypass due to the vsyscall 2325 fixed address mapping. Attempts to use the vsyscalls 2326 will be reported to dmesg, so that either old or 2327 malicious userspace programs can be identified. 2328 2329endchoice 2330 2331config CMDLINE_BOOL 2332 bool "Built-in kernel command line" 2333 ---help--- 2334 Allow for specifying boot arguments to the kernel at 2335 build time. On some systems (e.g. embedded ones), it is 2336 necessary or convenient to provide some or all of the 2337 kernel boot arguments with the kernel itself (that is, 2338 to not rely on the boot loader to provide them.) 2339 2340 To compile command line arguments into the kernel, 2341 set this option to 'Y', then fill in the 2342 boot arguments in CONFIG_CMDLINE. 2343 2344 Systems with fully functional boot loaders (i.e. non-embedded) 2345 should leave this option set to 'N'. 2346 2347config CMDLINE 2348 string "Built-in kernel command string" 2349 depends on CMDLINE_BOOL 2350 default "" 2351 ---help--- 2352 Enter arguments here that should be compiled into the kernel 2353 image and used at boot time. If the boot loader provides a 2354 command line at boot time, it is appended to this string to 2355 form the full kernel command line, when the system boots. 2356 2357 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2358 change this behavior. 2359 2360 In most cases, the command line (whether built-in or provided 2361 by the boot loader) should specify the device for the root 2362 file system. 2363 2364config CMDLINE_OVERRIDE 2365 bool "Built-in command line overrides boot loader arguments" 2366 depends on CMDLINE_BOOL 2367 ---help--- 2368 Set this option to 'Y' to have the kernel ignore the boot loader 2369 command line, and use ONLY the built-in command line. 2370 2371 This is used to work around broken boot loaders. This should 2372 be set to 'N' under normal conditions. 2373 2374config MODIFY_LDT_SYSCALL 2375 bool "Enable the LDT (local descriptor table)" if EXPERT 2376 default y 2377 ---help--- 2378 Linux can allow user programs to install a per-process x86 2379 Local Descriptor Table (LDT) using the modify_ldt(2) system 2380 call. This is required to run 16-bit or segmented code such as 2381 DOSEMU or some Wine programs. It is also used by some very old 2382 threading libraries. 2383 2384 Enabling this feature adds a small amount of overhead to 2385 context switches and increases the low-level kernel attack 2386 surface. Disabling it removes the modify_ldt(2) system call. 2387 2388 Saying 'N' here may make sense for embedded or server kernels. 2389 2390source "kernel/livepatch/Kconfig" 2391 2392endmenu 2393 2394config ARCH_HAS_ADD_PAGES 2395 def_bool y 2396 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2397 2398config ARCH_ENABLE_MEMORY_HOTPLUG 2399 def_bool y 2400 depends on X86_64 || (X86_32 && HIGHMEM) 2401 2402config ARCH_ENABLE_MEMORY_HOTREMOVE 2403 def_bool y 2404 depends on MEMORY_HOTPLUG 2405 2406config USE_PERCPU_NUMA_NODE_ID 2407 def_bool y 2408 depends on NUMA 2409 2410config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2411 def_bool y 2412 depends on X86_64 || X86_PAE 2413 2414config ARCH_ENABLE_HUGEPAGE_MIGRATION 2415 def_bool y 2416 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2417 2418config ARCH_ENABLE_THP_MIGRATION 2419 def_bool y 2420 depends on X86_64 && TRANSPARENT_HUGEPAGE 2421 2422menu "Power management and ACPI options" 2423 2424config ARCH_HIBERNATION_HEADER 2425 def_bool y 2426 depends on HIBERNATION 2427 2428source "kernel/power/Kconfig" 2429 2430source "drivers/acpi/Kconfig" 2431 2432source "drivers/sfi/Kconfig" 2433 2434config X86_APM_BOOT 2435 def_bool y 2436 depends on APM 2437 2438menuconfig APM 2439 tristate "APM (Advanced Power Management) BIOS support" 2440 depends on X86_32 && PM_SLEEP 2441 ---help--- 2442 APM is a BIOS specification for saving power using several different 2443 techniques. This is mostly useful for battery powered laptops with 2444 APM compliant BIOSes. If you say Y here, the system time will be 2445 reset after a RESUME operation, the /proc/apm device will provide 2446 battery status information, and user-space programs will receive 2447 notification of APM "events" (e.g. battery status change). 2448 2449 If you select "Y" here, you can disable actual use of the APM 2450 BIOS by passing the "apm=off" option to the kernel at boot time. 2451 2452 Note that the APM support is almost completely disabled for 2453 machines with more than one CPU. 2454 2455 In order to use APM, you will need supporting software. For location 2456 and more information, read <file:Documentation/power/apm-acpi.txt> 2457 and the Battery Powered Linux mini-HOWTO, available from 2458 <http://www.tldp.org/docs.html#howto>. 2459 2460 This driver does not spin down disk drives (see the hdparm(8) 2461 manpage ("man 8 hdparm") for that), and it doesn't turn off 2462 VESA-compliant "green" monitors. 2463 2464 This driver does not support the TI 4000M TravelMate and the ACER 2465 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2466 desktop machines also don't have compliant BIOSes, and this driver 2467 may cause those machines to panic during the boot phase. 2468 2469 Generally, if you don't have a battery in your machine, there isn't 2470 much point in using this driver and you should say N. If you get 2471 random kernel OOPSes or reboots that don't seem to be related to 2472 anything, try disabling/enabling this option (or disabling/enabling 2473 APM in your BIOS). 2474 2475 Some other things you should try when experiencing seemingly random, 2476 "weird" problems: 2477 2478 1) make sure that you have enough swap space and that it is 2479 enabled. 2480 2) pass the "no-hlt" option to the kernel 2481 3) switch on floating point emulation in the kernel and pass 2482 the "no387" option to the kernel 2483 4) pass the "floppy=nodma" option to the kernel 2484 5) pass the "mem=4M" option to the kernel (thereby disabling 2485 all but the first 4 MB of RAM) 2486 6) make sure that the CPU is not over clocked. 2487 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2488 8) disable the cache from your BIOS settings 2489 9) install a fan for the video card or exchange video RAM 2490 10) install a better fan for the CPU 2491 11) exchange RAM chips 2492 12) exchange the motherboard. 2493 2494 To compile this driver as a module, choose M here: the 2495 module will be called apm. 2496 2497if APM 2498 2499config APM_IGNORE_USER_SUSPEND 2500 bool "Ignore USER SUSPEND" 2501 ---help--- 2502 This option will ignore USER SUSPEND requests. On machines with a 2503 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2504 series notebooks, it is necessary to say Y because of a BIOS bug. 2505 2506config APM_DO_ENABLE 2507 bool "Enable PM at boot time" 2508 ---help--- 2509 Enable APM features at boot time. From page 36 of the APM BIOS 2510 specification: "When disabled, the APM BIOS does not automatically 2511 power manage devices, enter the Standby State, enter the Suspend 2512 State, or take power saving steps in response to CPU Idle calls." 2513 This driver will make CPU Idle calls when Linux is idle (unless this 2514 feature is turned off -- see "Do CPU IDLE calls", below). This 2515 should always save battery power, but more complicated APM features 2516 will be dependent on your BIOS implementation. You may need to turn 2517 this option off if your computer hangs at boot time when using APM 2518 support, or if it beeps continuously instead of suspending. Turn 2519 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2520 T400CDT. This is off by default since most machines do fine without 2521 this feature. 2522 2523config APM_CPU_IDLE 2524 depends on CPU_IDLE 2525 bool "Make CPU Idle calls when idle" 2526 ---help--- 2527 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2528 On some machines, this can activate improved power savings, such as 2529 a slowed CPU clock rate, when the machine is idle. These idle calls 2530 are made after the idle loop has run for some length of time (e.g., 2531 333 mS). On some machines, this will cause a hang at boot time or 2532 whenever the CPU becomes idle. (On machines with more than one CPU, 2533 this option does nothing.) 2534 2535config APM_DISPLAY_BLANK 2536 bool "Enable console blanking using APM" 2537 ---help--- 2538 Enable console blanking using the APM. Some laptops can use this to 2539 turn off the LCD backlight when the screen blanker of the Linux 2540 virtual console blanks the screen. Note that this is only used by 2541 the virtual console screen blanker, and won't turn off the backlight 2542 when using the X Window system. This also doesn't have anything to 2543 do with your VESA-compliant power-saving monitor. Further, this 2544 option doesn't work for all laptops -- it might not turn off your 2545 backlight at all, or it might print a lot of errors to the console, 2546 especially if you are using gpm. 2547 2548config APM_ALLOW_INTS 2549 bool "Allow interrupts during APM BIOS calls" 2550 ---help--- 2551 Normally we disable external interrupts while we are making calls to 2552 the APM BIOS as a measure to lessen the effects of a badly behaving 2553 BIOS implementation. The BIOS should reenable interrupts if it 2554 needs to. Unfortunately, some BIOSes do not -- especially those in 2555 many of the newer IBM Thinkpads. If you experience hangs when you 2556 suspend, try setting this to Y. Otherwise, say N. 2557 2558endif # APM 2559 2560source "drivers/cpufreq/Kconfig" 2561 2562source "drivers/cpuidle/Kconfig" 2563 2564source "drivers/idle/Kconfig" 2565 2566endmenu 2567 2568 2569menu "Bus options (PCI etc.)" 2570 2571config PCI 2572 bool "PCI support" 2573 default y 2574 ---help--- 2575 Find out whether you have a PCI motherboard. PCI is the name of a 2576 bus system, i.e. the way the CPU talks to the other stuff inside 2577 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2578 VESA. If you have PCI, say Y, otherwise N. 2579 2580choice 2581 prompt "PCI access mode" 2582 depends on X86_32 && PCI 2583 default PCI_GOANY 2584 ---help--- 2585 On PCI systems, the BIOS can be used to detect the PCI devices and 2586 determine their configuration. However, some old PCI motherboards 2587 have BIOS bugs and may crash if this is done. Also, some embedded 2588 PCI-based systems don't have any BIOS at all. Linux can also try to 2589 detect the PCI hardware directly without using the BIOS. 2590 2591 With this option, you can specify how Linux should detect the 2592 PCI devices. If you choose "BIOS", the BIOS will be used, 2593 if you choose "Direct", the BIOS won't be used, and if you 2594 choose "MMConfig", then PCI Express MMCONFIG will be used. 2595 If you choose "Any", the kernel will try MMCONFIG, then the 2596 direct access method and falls back to the BIOS if that doesn't 2597 work. If unsure, go with the default, which is "Any". 2598 2599config PCI_GOBIOS 2600 bool "BIOS" 2601 2602config PCI_GOMMCONFIG 2603 bool "MMConfig" 2604 2605config PCI_GODIRECT 2606 bool "Direct" 2607 2608config PCI_GOOLPC 2609 bool "OLPC XO-1" 2610 depends on OLPC 2611 2612config PCI_GOANY 2613 bool "Any" 2614 2615endchoice 2616 2617config PCI_BIOS 2618 def_bool y 2619 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2620 2621# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2622config PCI_DIRECT 2623 def_bool y 2624 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2625 2626config PCI_MMCONFIG 2627 bool "Support mmconfig PCI config space access" if X86_64 2628 default y 2629 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2630 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2631 2632config PCI_OLPC 2633 def_bool y 2634 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2635 2636config PCI_XEN 2637 def_bool y 2638 depends on PCI && XEN 2639 select SWIOTLB_XEN 2640 2641config PCI_DOMAINS 2642 def_bool y 2643 depends on PCI 2644 2645config MMCONF_FAM10H 2646 def_bool y 2647 depends on X86_64 && PCI_MMCONFIG && ACPI 2648 2649config PCI_CNB20LE_QUIRK 2650 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2651 depends on PCI 2652 help 2653 Read the PCI windows out of the CNB20LE host bridge. This allows 2654 PCI hotplug to work on systems with the CNB20LE chipset which do 2655 not have ACPI. 2656 2657 There's no public spec for this chipset, and this functionality 2658 is known to be incomplete. 2659 2660 You should say N unless you know you need this. 2661 2662source "drivers/pci/Kconfig" 2663 2664config ISA_BUS 2665 bool "ISA bus support on modern systems" if EXPERT 2666 help 2667 Expose ISA bus device drivers and options available for selection and 2668 configuration. Enable this option if your target machine has an ISA 2669 bus. ISA is an older system, displaced by PCI and newer bus 2670 architectures -- if your target machine is modern, it probably does 2671 not have an ISA bus. 2672 2673 If unsure, say N. 2674 2675# x86_64 have no ISA slots, but can have ISA-style DMA. 2676config ISA_DMA_API 2677 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2678 default y 2679 help 2680 Enables ISA-style DMA support for devices requiring such controllers. 2681 If unsure, say Y. 2682 2683if X86_32 2684 2685config ISA 2686 bool "ISA support" 2687 ---help--- 2688 Find out whether you have ISA slots on your motherboard. ISA is the 2689 name of a bus system, i.e. the way the CPU talks to the other stuff 2690 inside your box. Other bus systems are PCI, EISA, MicroChannel 2691 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2692 newer boards don't support it. If you have ISA, say Y, otherwise N. 2693 2694config EISA 2695 bool "EISA support" 2696 depends on ISA 2697 ---help--- 2698 The Extended Industry Standard Architecture (EISA) bus was 2699 developed as an open alternative to the IBM MicroChannel bus. 2700 2701 The EISA bus provided some of the features of the IBM MicroChannel 2702 bus while maintaining backward compatibility with cards made for 2703 the older ISA bus. The EISA bus saw limited use between 1988 and 2704 1995 when it was made obsolete by the PCI bus. 2705 2706 Say Y here if you are building a kernel for an EISA-based machine. 2707 2708 Otherwise, say N. 2709 2710source "drivers/eisa/Kconfig" 2711 2712config SCx200 2713 tristate "NatSemi SCx200 support" 2714 ---help--- 2715 This provides basic support for National Semiconductor's 2716 (now AMD's) Geode processors. The driver probes for the 2717 PCI-IDs of several on-chip devices, so its a good dependency 2718 for other scx200_* drivers. 2719 2720 If compiled as a module, the driver is named scx200. 2721 2722config SCx200HR_TIMER 2723 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2724 depends on SCx200 2725 default y 2726 ---help--- 2727 This driver provides a clocksource built upon the on-chip 2728 27MHz high-resolution timer. Its also a workaround for 2729 NSC Geode SC-1100's buggy TSC, which loses time when the 2730 processor goes idle (as is done by the scheduler). The 2731 other workaround is idle=poll boot option. 2732 2733config OLPC 2734 bool "One Laptop Per Child support" 2735 depends on !X86_PAE 2736 select GPIOLIB 2737 select OF 2738 select OF_PROMTREE 2739 select IRQ_DOMAIN 2740 ---help--- 2741 Add support for detecting the unique features of the OLPC 2742 XO hardware. 2743 2744config OLPC_XO1_PM 2745 bool "OLPC XO-1 Power Management" 2746 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2747 ---help--- 2748 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2749 2750config OLPC_XO1_RTC 2751 bool "OLPC XO-1 Real Time Clock" 2752 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2753 ---help--- 2754 Add support for the XO-1 real time clock, which can be used as a 2755 programmable wakeup source. 2756 2757config OLPC_XO1_SCI 2758 bool "OLPC XO-1 SCI extras" 2759 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2760 depends on INPUT=y 2761 select POWER_SUPPLY 2762 ---help--- 2763 Add support for SCI-based features of the OLPC XO-1 laptop: 2764 - EC-driven system wakeups 2765 - Power button 2766 - Ebook switch 2767 - Lid switch 2768 - AC adapter status updates 2769 - Battery status updates 2770 2771config OLPC_XO15_SCI 2772 bool "OLPC XO-1.5 SCI extras" 2773 depends on OLPC && ACPI 2774 select POWER_SUPPLY 2775 ---help--- 2776 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2777 - EC-driven system wakeups 2778 - AC adapter status updates 2779 - Battery status updates 2780 2781config ALIX 2782 bool "PCEngines ALIX System Support (LED setup)" 2783 select GPIOLIB 2784 ---help--- 2785 This option enables system support for the PCEngines ALIX. 2786 At present this just sets up LEDs for GPIO control on 2787 ALIX2/3/6 boards. However, other system specific setup should 2788 get added here. 2789 2790 Note: You must still enable the drivers for GPIO and LED support 2791 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2792 2793 Note: You have to set alix.force=1 for boards with Award BIOS. 2794 2795config NET5501 2796 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2797 select GPIOLIB 2798 ---help--- 2799 This option enables system support for the Soekris Engineering net5501. 2800 2801config GEOS 2802 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2803 select GPIOLIB 2804 depends on DMI 2805 ---help--- 2806 This option enables system support for the Traverse Technologies GEOS. 2807 2808config TS5500 2809 bool "Technologic Systems TS-5500 platform support" 2810 depends on MELAN 2811 select CHECK_SIGNATURE 2812 select NEW_LEDS 2813 select LEDS_CLASS 2814 ---help--- 2815 This option enables system support for the Technologic Systems TS-5500. 2816 2817endif # X86_32 2818 2819config AMD_NB 2820 def_bool y 2821 depends on CPU_SUP_AMD && PCI 2822 2823source "drivers/pcmcia/Kconfig" 2824 2825config RAPIDIO 2826 tristate "RapidIO support" 2827 depends on PCI 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 advertised 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