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_DEBUG_STACKOVERFLOW 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 select GENERIC_VDSO_32 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 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 ARCH_HAS_SYSCALL_WRAPPER 34 35config FORCE_DYNAMIC_FTRACE 36 def_bool y 37 depends on X86_32 38 depends on FUNCTION_TRACER 39 select DYNAMIC_FTRACE 40 help 41 We keep the static function tracing (!DYNAMIC_FTRACE) around 42 in order to test the non static function tracing in the 43 generic code, as other architectures still use it. But we 44 only need to keep it around for x86_64. No need to keep it 45 for x86_32. For x86_32, force DYNAMIC_FTRACE. 46# 47# Arch settings 48# 49# ( Note that options that are marked 'if X86_64' could in principle be 50# ported to 32-bit as well. ) 51# 52config X86 53 def_bool y 54 # 55 # Note: keep this list sorted alphabetically 56 # 57 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 59 select ARCH_32BIT_OFF_T if X86_32 60 select ARCH_CLOCKSOURCE_DATA 61 select ARCH_CLOCKSOURCE_INIT 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 63 select ARCH_HAS_DEBUG_VIRTUAL 64 select ARCH_HAS_DEVMEM_IS_ALLOWED 65 select ARCH_HAS_ELF_RANDOMIZE 66 select ARCH_HAS_FAST_MULTIPLIER 67 select ARCH_HAS_FILTER_PGPROT 68 select ARCH_HAS_FORTIFY_SOURCE 69 select ARCH_HAS_GCOV_PROFILE_ALL 70 select ARCH_HAS_KCOV if X86_64 71 select ARCH_HAS_MEMBARRIER_SYNC_CORE 72 select ARCH_HAS_PMEM_API if X86_64 73 select ARCH_HAS_PTE_SPECIAL 74 select ARCH_HAS_REFCOUNT 75 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 76 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 77 select ARCH_HAS_SET_MEMORY 78 select ARCH_HAS_SET_DIRECT_MAP 79 select ARCH_HAS_STRICT_KERNEL_RWX 80 select ARCH_HAS_STRICT_MODULE_RWX 81 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 82 select ARCH_HAS_UBSAN_SANITIZE_ALL 83 select ARCH_HAS_ZONE_DEVICE if X86_64 84 select ARCH_HAVE_NMI_SAFE_CMPXCHG 85 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 86 select ARCH_MIGHT_HAVE_PC_PARPORT 87 select ARCH_MIGHT_HAVE_PC_SERIO 88 select ARCH_STACKWALK 89 select ARCH_SUPPORTS_ACPI 90 select ARCH_SUPPORTS_ATOMIC_RMW 91 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 92 select ARCH_USE_BUILTIN_BSWAP 93 select ARCH_USE_QUEUED_RWLOCKS 94 select ARCH_USE_QUEUED_SPINLOCKS 95 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 96 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 97 select ARCH_WANTS_THP_SWAP if X86_64 98 select BUILDTIME_EXTABLE_SORT 99 select CLKEVT_I8253 100 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 101 select CLOCKSOURCE_WATCHDOG 102 select DCACHE_WORD_ACCESS 103 select EDAC_ATOMIC_SCRUB 104 select EDAC_SUPPORT 105 select GENERIC_CLOCKEVENTS 106 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 107 select GENERIC_CLOCKEVENTS_MIN_ADJUST 108 select GENERIC_CMOS_UPDATE 109 select GENERIC_CPU_AUTOPROBE 110 select GENERIC_CPU_VULNERABILITIES 111 select GENERIC_EARLY_IOREMAP 112 select GENERIC_FIND_FIRST_BIT 113 select GENERIC_IOMAP 114 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 115 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 116 select GENERIC_IRQ_MIGRATION if SMP 117 select GENERIC_IRQ_PROBE 118 select GENERIC_IRQ_RESERVATION_MODE 119 select GENERIC_IRQ_SHOW 120 select GENERIC_PENDING_IRQ if SMP 121 select GENERIC_SMP_IDLE_THREAD 122 select GENERIC_STRNCPY_FROM_USER 123 select GENERIC_STRNLEN_USER 124 select GENERIC_TIME_VSYSCALL 125 select GENERIC_GETTIMEOFDAY 126 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 127 select HAVE_ACPI_APEI if ACPI 128 select HAVE_ACPI_APEI_NMI if ACPI 129 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 130 select HAVE_ARCH_AUDITSYSCALL 131 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 132 select HAVE_ARCH_JUMP_LABEL 133 select HAVE_ARCH_JUMP_LABEL_RELATIVE 134 select HAVE_ARCH_KASAN if X86_64 135 select HAVE_ARCH_KGDB 136 select HAVE_ARCH_MMAP_RND_BITS if MMU 137 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 138 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 139 select HAVE_ARCH_PREL32_RELOCATIONS 140 select HAVE_ARCH_SECCOMP_FILTER 141 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 142 select HAVE_ARCH_STACKLEAK 143 select HAVE_ARCH_TRACEHOOK 144 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 145 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 146 select HAVE_ARCH_VMAP_STACK if X86_64 147 select HAVE_ARCH_WITHIN_STACK_FRAMES 148 select HAVE_CMPXCHG_DOUBLE 149 select HAVE_CMPXCHG_LOCAL 150 select HAVE_CONTEXT_TRACKING if X86_64 151 select HAVE_COPY_THREAD_TLS 152 select HAVE_C_RECORDMCOUNT 153 select HAVE_DEBUG_KMEMLEAK 154 select HAVE_DMA_CONTIGUOUS 155 select HAVE_DYNAMIC_FTRACE 156 select HAVE_DYNAMIC_FTRACE_WITH_REGS 157 select HAVE_EBPF_JIT 158 select HAVE_EFFICIENT_UNALIGNED_ACCESS 159 select HAVE_EISA 160 select HAVE_EXIT_THREAD 161 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 162 select HAVE_FTRACE_MCOUNT_RECORD 163 select HAVE_FUNCTION_GRAPH_TRACER 164 select HAVE_FUNCTION_TRACER 165 select HAVE_GCC_PLUGINS 166 select HAVE_HW_BREAKPOINT 167 select HAVE_IDE 168 select HAVE_IOREMAP_PROT 169 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 170 select HAVE_IRQ_TIME_ACCOUNTING 171 select HAVE_KERNEL_BZIP2 172 select HAVE_KERNEL_GZIP 173 select HAVE_KERNEL_LZ4 174 select HAVE_KERNEL_LZMA 175 select HAVE_KERNEL_LZO 176 select HAVE_KERNEL_XZ 177 select HAVE_KPROBES 178 select HAVE_KPROBES_ON_FTRACE 179 select HAVE_FUNCTION_ERROR_INJECTION 180 select HAVE_KRETPROBES 181 select HAVE_KVM 182 select HAVE_LIVEPATCH if X86_64 183 select HAVE_MEMBLOCK_NODE_MAP 184 select HAVE_MIXED_BREAKPOINTS_REGS 185 select HAVE_MOD_ARCH_SPECIFIC 186 select HAVE_MOVE_PMD 187 select HAVE_NMI 188 select HAVE_OPROFILE 189 select HAVE_OPTPROBES 190 select HAVE_PCSPKR_PLATFORM 191 select HAVE_PERF_EVENTS 192 select HAVE_PERF_EVENTS_NMI 193 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 194 select HAVE_PCI 195 select HAVE_PERF_REGS 196 select HAVE_PERF_USER_STACK_DUMP 197 select HAVE_RCU_TABLE_FREE if PARAVIRT 198 select HAVE_REGS_AND_STACK_ACCESS_API 199 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 200 select HAVE_FUNCTION_ARG_ACCESS_API 201 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 202 select HAVE_STACK_VALIDATION if X86_64 203 select HAVE_RSEQ 204 select HAVE_SYSCALL_TRACEPOINTS 205 select HAVE_UNSTABLE_SCHED_CLOCK 206 select HAVE_USER_RETURN_NOTIFIER 207 select HAVE_GENERIC_VDSO 208 select HOTPLUG_SMT if SMP 209 select IRQ_FORCED_THREADING 210 select NEED_SG_DMA_LENGTH 211 select PCI_DOMAINS if PCI 212 select PCI_LOCKLESS_CONFIG if PCI 213 select PERF_EVENTS 214 select RTC_LIB 215 select RTC_MC146818_LIB 216 select SPARSE_IRQ 217 select SRCU 218 select SYSCTL_EXCEPTION_TRACE 219 select THREAD_INFO_IN_TASK 220 select USER_STACKTRACE_SUPPORT 221 select VIRT_TO_BUS 222 select X86_FEATURE_NAMES if PROC_FS 223 224config INSTRUCTION_DECODER 225 def_bool y 226 depends on KPROBES || PERF_EVENTS || UPROBES 227 228config OUTPUT_FORMAT 229 string 230 default "elf32-i386" if X86_32 231 default "elf64-x86-64" if X86_64 232 233config ARCH_DEFCONFIG 234 string 235 default "arch/x86/configs/i386_defconfig" if X86_32 236 default "arch/x86/configs/x86_64_defconfig" if X86_64 237 238config LOCKDEP_SUPPORT 239 def_bool y 240 241config STACKTRACE_SUPPORT 242 def_bool y 243 244config MMU 245 def_bool y 246 247config ARCH_MMAP_RND_BITS_MIN 248 default 28 if 64BIT 249 default 8 250 251config ARCH_MMAP_RND_BITS_MAX 252 default 32 if 64BIT 253 default 16 254 255config ARCH_MMAP_RND_COMPAT_BITS_MIN 256 default 8 257 258config ARCH_MMAP_RND_COMPAT_BITS_MAX 259 default 16 260 261config SBUS 262 bool 263 264config GENERIC_ISA_DMA 265 def_bool y 266 depends on ISA_DMA_API 267 268config GENERIC_BUG 269 def_bool y 270 depends on BUG 271 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 272 273config GENERIC_BUG_RELATIVE_POINTERS 274 bool 275 276config ARCH_MAY_HAVE_PC_FDC 277 def_bool y 278 depends on ISA_DMA_API 279 280config GENERIC_CALIBRATE_DELAY 281 def_bool y 282 283config ARCH_HAS_CPU_RELAX 284 def_bool y 285 286config ARCH_HAS_CACHE_LINE_SIZE 287 def_bool y 288 289config ARCH_HAS_FILTER_PGPROT 290 def_bool y 291 292config HAVE_SETUP_PER_CPU_AREA 293 def_bool y 294 295config NEED_PER_CPU_EMBED_FIRST_CHUNK 296 def_bool y 297 298config NEED_PER_CPU_PAGE_FIRST_CHUNK 299 def_bool y 300 301config ARCH_HIBERNATION_POSSIBLE 302 def_bool y 303 304config ARCH_SUSPEND_POSSIBLE 305 def_bool y 306 307config ARCH_WANT_HUGE_PMD_SHARE 308 def_bool y 309 310config ARCH_WANT_GENERAL_HUGETLB 311 def_bool y 312 313config ZONE_DMA32 314 def_bool y if X86_64 315 316config AUDIT_ARCH 317 def_bool y if X86_64 318 319config ARCH_SUPPORTS_DEBUG_PAGEALLOC 320 def_bool y 321 322config KASAN_SHADOW_OFFSET 323 hex 324 depends on KASAN 325 default 0xdffffc0000000000 326 327config HAVE_INTEL_TXT 328 def_bool y 329 depends on INTEL_IOMMU && ACPI 330 331config X86_32_SMP 332 def_bool y 333 depends on X86_32 && SMP 334 335config X86_64_SMP 336 def_bool y 337 depends on X86_64 && SMP 338 339config X86_32_LAZY_GS 340 def_bool y 341 depends on X86_32 && !STACKPROTECTOR 342 343config ARCH_SUPPORTS_UPROBES 344 def_bool y 345 346config FIX_EARLYCON_MEM 347 def_bool y 348 349config DYNAMIC_PHYSICAL_MASK 350 bool 351 352config PGTABLE_LEVELS 353 int 354 default 5 if X86_5LEVEL 355 default 4 if X86_64 356 default 3 if X86_PAE 357 default 2 358 359config CC_HAS_SANE_STACKPROTECTOR 360 bool 361 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 362 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 363 help 364 We have to make sure stack protector is unconditionally disabled if 365 the compiler produces broken code. 366 367menu "Processor type and features" 368 369config ZONE_DMA 370 bool "DMA memory allocation support" if EXPERT 371 default y 372 help 373 DMA memory allocation support allows devices with less than 32-bit 374 addressing to allocate within the first 16MB of address space. 375 Disable if no such devices will be used. 376 377 If unsure, say Y. 378 379config SMP 380 bool "Symmetric multi-processing support" 381 ---help--- 382 This enables support for systems with more than one CPU. If you have 383 a system with only one CPU, say N. If you have a system with more 384 than one CPU, say Y. 385 386 If you say N here, the kernel will run on uni- and multiprocessor 387 machines, but will use only one CPU of a multiprocessor machine. If 388 you say Y here, the kernel will run on many, but not all, 389 uniprocessor machines. On a uniprocessor machine, the kernel 390 will run faster if you say N here. 391 392 Note that if you say Y here and choose architecture "586" or 393 "Pentium" under "Processor family", the kernel will not work on 486 394 architectures. Similarly, multiprocessor kernels for the "PPro" 395 architecture may not work on all Pentium based boards. 396 397 People using multiprocessor machines who say Y here should also say 398 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 399 Management" code will be disabled if you say Y here. 400 401 See also <file:Documentation/x86/i386/IO-APIC.txt>, 402 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 403 <http://www.tldp.org/docs.html#howto>. 404 405 If you don't know what to do here, say N. 406 407config X86_FEATURE_NAMES 408 bool "Processor feature human-readable names" if EMBEDDED 409 default y 410 ---help--- 411 This option compiles in a table of x86 feature bits and corresponding 412 names. This is required to support /proc/cpuinfo and a few kernel 413 messages. You can disable this to save space, at the expense of 414 making those few kernel messages show numeric feature bits instead. 415 416 If in doubt, say Y. 417 418config X86_X2APIC 419 bool "Support x2apic" 420 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 421 ---help--- 422 This enables x2apic support on CPUs that have this feature. 423 424 This allows 32-bit apic IDs (so it can support very large systems), 425 and accesses the local apic via MSRs not via mmio. 426 427 If you don't know what to do here, say N. 428 429config X86_MPPARSE 430 bool "Enable MPS table" if ACPI || SFI 431 default y 432 depends on X86_LOCAL_APIC 433 ---help--- 434 For old smp systems that do not have proper acpi support. Newer systems 435 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 436 437config GOLDFISH 438 def_bool y 439 depends on X86_GOLDFISH 440 441config RETPOLINE 442 bool "Avoid speculative indirect branches in kernel" 443 default y 444 select STACK_VALIDATION if HAVE_STACK_VALIDATION 445 help 446 Compile kernel with the retpoline compiler options to guard against 447 kernel-to-user data leaks by avoiding speculative indirect 448 branches. Requires a compiler with -mindirect-branch=thunk-extern 449 support for full protection. The kernel may run slower. 450 451config X86_CPU_RESCTRL 452 bool "x86 CPU resource control support" 453 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 454 select KERNFS 455 help 456 Enable x86 CPU resource control support. 457 458 Provide support for the allocation and monitoring of system resources 459 usage by the CPU. 460 461 Intel calls this Intel Resource Director Technology 462 (Intel(R) RDT). More information about RDT can be found in the 463 Intel x86 Architecture Software Developer Manual. 464 465 AMD calls this AMD Platform Quality of Service (AMD QoS). 466 More information about AMD QoS can be found in the AMD64 Technology 467 Platform Quality of Service Extensions manual. 468 469 Say N if unsure. 470 471if X86_32 472config X86_BIGSMP 473 bool "Support for big SMP systems with more than 8 CPUs" 474 depends on SMP 475 ---help--- 476 This option is needed for the systems that have more than 8 CPUs 477 478config X86_EXTENDED_PLATFORM 479 bool "Support for extended (non-PC) x86 platforms" 480 default y 481 ---help--- 482 If you disable this option then the kernel will only support 483 standard PC platforms. (which covers the vast majority of 484 systems out there.) 485 486 If you enable this option then you'll be able to select support 487 for the following (non-PC) 32 bit x86 platforms: 488 Goldfish (Android emulator) 489 AMD Elan 490 RDC R-321x SoC 491 SGI 320/540 (Visual Workstation) 492 STA2X11-based (e.g. Northville) 493 Moorestown MID devices 494 495 If you have one of these systems, or if you want to build a 496 generic distribution kernel, say Y here - otherwise say N. 497endif 498 499if X86_64 500config X86_EXTENDED_PLATFORM 501 bool "Support for extended (non-PC) x86 platforms" 502 default y 503 ---help--- 504 If you disable this option then the kernel will only support 505 standard PC platforms. (which covers the vast majority of 506 systems out there.) 507 508 If you enable this option then you'll be able to select support 509 for the following (non-PC) 64 bit x86 platforms: 510 Numascale NumaChip 511 ScaleMP vSMP 512 SGI Ultraviolet 513 514 If you have one of these systems, or if you want to build a 515 generic distribution kernel, say Y here - otherwise say N. 516endif 517# This is an alphabetically sorted list of 64 bit extended platforms 518# Please maintain the alphabetic order if and when there are additions 519config X86_NUMACHIP 520 bool "Numascale NumaChip" 521 depends on X86_64 522 depends on X86_EXTENDED_PLATFORM 523 depends on NUMA 524 depends on SMP 525 depends on X86_X2APIC 526 depends on PCI_MMCONFIG 527 ---help--- 528 Adds support for Numascale NumaChip large-SMP systems. Needed to 529 enable more than ~168 cores. 530 If you don't have one of these, you should say N here. 531 532config X86_VSMP 533 bool "ScaleMP vSMP" 534 select HYPERVISOR_GUEST 535 select PARAVIRT 536 depends on X86_64 && PCI 537 depends on X86_EXTENDED_PLATFORM 538 depends on SMP 539 ---help--- 540 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 541 supposed to run on these EM64T-based machines. Only choose this option 542 if you have one of these machines. 543 544config X86_UV 545 bool "SGI Ultraviolet" 546 depends on X86_64 547 depends on X86_EXTENDED_PLATFORM 548 depends on NUMA 549 depends on EFI 550 depends on X86_X2APIC 551 depends on PCI 552 ---help--- 553 This option is needed in order to support SGI Ultraviolet systems. 554 If you don't have one of these, you should say N here. 555 556# Following is an alphabetically sorted list of 32 bit extended platforms 557# Please maintain the alphabetic order if and when there are additions 558 559config X86_GOLDFISH 560 bool "Goldfish (Virtual Platform)" 561 depends on X86_EXTENDED_PLATFORM 562 ---help--- 563 Enable support for the Goldfish virtual platform used primarily 564 for Android development. Unless you are building for the Android 565 Goldfish emulator say N here. 566 567config X86_INTEL_CE 568 bool "CE4100 TV platform" 569 depends on PCI 570 depends on PCI_GODIRECT 571 depends on X86_IO_APIC 572 depends on X86_32 573 depends on X86_EXTENDED_PLATFORM 574 select X86_REBOOTFIXUPS 575 select OF 576 select OF_EARLY_FLATTREE 577 ---help--- 578 Select for the Intel CE media processor (CE4100) SOC. 579 This option compiles in support for the CE4100 SOC for settop 580 boxes and media devices. 581 582config X86_INTEL_MID 583 bool "Intel MID platform support" 584 depends on X86_EXTENDED_PLATFORM 585 depends on X86_PLATFORM_DEVICES 586 depends on PCI 587 depends on X86_64 || (PCI_GOANY && X86_32) 588 depends on X86_IO_APIC 589 select SFI 590 select I2C 591 select DW_APB_TIMER 592 select APB_TIMER 593 select INTEL_SCU_IPC 594 select MFD_INTEL_MSIC 595 ---help--- 596 Select to build a kernel capable of supporting Intel MID (Mobile 597 Internet Device) platform systems which do not have the PCI legacy 598 interfaces. If you are building for a PC class system say N here. 599 600 Intel MID platforms are based on an Intel processor and chipset which 601 consume less power than most of the x86 derivatives. 602 603config X86_INTEL_QUARK 604 bool "Intel Quark platform support" 605 depends on X86_32 606 depends on X86_EXTENDED_PLATFORM 607 depends on X86_PLATFORM_DEVICES 608 depends on X86_TSC 609 depends on PCI 610 depends on PCI_GOANY 611 depends on X86_IO_APIC 612 select IOSF_MBI 613 select INTEL_IMR 614 select COMMON_CLK 615 ---help--- 616 Select to include support for Quark X1000 SoC. 617 Say Y here if you have a Quark based system such as the Arduino 618 compatible Intel Galileo. 619 620config X86_INTEL_LPSS 621 bool "Intel Low Power Subsystem Support" 622 depends on X86 && ACPI && PCI 623 select COMMON_CLK 624 select PINCTRL 625 select IOSF_MBI 626 ---help--- 627 Select to build support for Intel Low Power Subsystem such as 628 found on Intel Lynxpoint PCH. Selecting this option enables 629 things like clock tree (common clock framework) and pincontrol 630 which are needed by the LPSS peripheral drivers. 631 632config X86_AMD_PLATFORM_DEVICE 633 bool "AMD ACPI2Platform devices support" 634 depends on ACPI 635 select COMMON_CLK 636 select PINCTRL 637 ---help--- 638 Select to interpret AMD specific ACPI device to platform device 639 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 640 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 641 implemented under PINCTRL subsystem. 642 643config IOSF_MBI 644 tristate "Intel SoC IOSF Sideband support for SoC platforms" 645 depends on PCI 646 ---help--- 647 This option enables sideband register access support for Intel SoC 648 platforms. On these platforms the IOSF sideband is used in lieu of 649 MSR's for some register accesses, mostly but not limited to thermal 650 and power. Drivers may query the availability of this device to 651 determine if they need the sideband in order to work on these 652 platforms. The sideband is available on the following SoC products. 653 This list is not meant to be exclusive. 654 - BayTrail 655 - Braswell 656 - Quark 657 658 You should say Y if you are running a kernel on one of these SoC's. 659 660config IOSF_MBI_DEBUG 661 bool "Enable IOSF sideband access through debugfs" 662 depends on IOSF_MBI && DEBUG_FS 663 ---help--- 664 Select this option to expose the IOSF sideband access registers (MCR, 665 MDR, MCRX) through debugfs to write and read register information from 666 different units on the SoC. This is most useful for obtaining device 667 state information for debug and analysis. As this is a general access 668 mechanism, users of this option would have specific knowledge of the 669 device they want to access. 670 671 If you don't require the option or are in doubt, say N. 672 673config X86_RDC321X 674 bool "RDC R-321x SoC" 675 depends on X86_32 676 depends on X86_EXTENDED_PLATFORM 677 select M486 678 select X86_REBOOTFIXUPS 679 ---help--- 680 This option is needed for RDC R-321x system-on-chip, also known 681 as R-8610-(G). 682 If you don't have one of these chips, you should say N here. 683 684config X86_32_NON_STANDARD 685 bool "Support non-standard 32-bit SMP architectures" 686 depends on X86_32 && SMP 687 depends on X86_EXTENDED_PLATFORM 688 ---help--- 689 This option compiles in the bigsmp and STA2X11 default 690 subarchitectures. It is intended for a generic binary 691 kernel. If you select them all, kernel will probe it one by 692 one and will fallback to default. 693 694# Alphabetically sorted list of Non standard 32 bit platforms 695 696config X86_SUPPORTS_MEMORY_FAILURE 697 def_bool y 698 # MCE code calls memory_failure(): 699 depends on X86_MCE 700 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 701 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 702 depends on X86_64 || !SPARSEMEM 703 select ARCH_SUPPORTS_MEMORY_FAILURE 704 705config STA2X11 706 bool "STA2X11 Companion Chip Support" 707 depends on X86_32_NON_STANDARD && PCI 708 select ARCH_HAS_PHYS_TO_DMA 709 select SWIOTLB 710 select MFD_STA2X11 711 select GPIOLIB 712 ---help--- 713 This adds support for boards based on the STA2X11 IO-Hub, 714 a.k.a. "ConneXt". The chip is used in place of the standard 715 PC chipset, so all "standard" peripherals are missing. If this 716 option is selected the kernel will still be able to boot on 717 standard PC machines. 718 719config X86_32_IRIS 720 tristate "Eurobraille/Iris poweroff module" 721 depends on X86_32 722 ---help--- 723 The Iris machines from EuroBraille do not have APM or ACPI support 724 to shut themselves down properly. A special I/O sequence is 725 needed to do so, which is what this module does at 726 kernel shutdown. 727 728 This is only for Iris machines from EuroBraille. 729 730 If unused, say N. 731 732config SCHED_OMIT_FRAME_POINTER 733 def_bool y 734 prompt "Single-depth WCHAN output" 735 depends on X86 736 ---help--- 737 Calculate simpler /proc/<PID>/wchan values. If this option 738 is disabled then wchan values will recurse back to the 739 caller function. This provides more accurate wchan values, 740 at the expense of slightly more scheduling overhead. 741 742 If in doubt, say "Y". 743 744menuconfig HYPERVISOR_GUEST 745 bool "Linux guest support" 746 ---help--- 747 Say Y here to enable options for running Linux under various hyper- 748 visors. This option enables basic hypervisor detection and platform 749 setup. 750 751 If you say N, all options in this submenu will be skipped and 752 disabled, and Linux guest support won't be built in. 753 754if HYPERVISOR_GUEST 755 756config PARAVIRT 757 bool "Enable paravirtualization code" 758 ---help--- 759 This changes the kernel so it can modify itself when it is run 760 under a hypervisor, potentially improving performance significantly 761 over full virtualization. However, when run without a hypervisor 762 the kernel is theoretically slower and slightly larger. 763 764config PARAVIRT_XXL 765 bool 766 767config PARAVIRT_DEBUG 768 bool "paravirt-ops debugging" 769 depends on PARAVIRT && DEBUG_KERNEL 770 ---help--- 771 Enable to debug paravirt_ops internals. Specifically, BUG if 772 a paravirt_op is missing when it is called. 773 774config PARAVIRT_SPINLOCKS 775 bool "Paravirtualization layer for spinlocks" 776 depends on PARAVIRT && SMP 777 ---help--- 778 Paravirtualized spinlocks allow a pvops backend to replace the 779 spinlock implementation with something virtualization-friendly 780 (for example, block the virtual CPU rather than spinning). 781 782 It has a minimal impact on native kernels and gives a nice performance 783 benefit on paravirtualized KVM / Xen kernels. 784 785 If you are unsure how to answer this question, answer Y. 786 787source "arch/x86/xen/Kconfig" 788 789config KVM_GUEST 790 bool "KVM Guest support (including kvmclock)" 791 depends on PARAVIRT 792 select PARAVIRT_CLOCK 793 default y 794 ---help--- 795 This option enables various optimizations for running under the KVM 796 hypervisor. It includes a paravirtualized clock, so that instead 797 of relying on a PIT (or probably other) emulation by the 798 underlying device model, the host provides the guest with 799 timing infrastructure such as time of day, and system time 800 801config PVH 802 bool "Support for running PVH guests" 803 ---help--- 804 This option enables the PVH entry point for guest virtual machines 805 as specified in the x86/HVM direct boot ABI. 806 807config KVM_DEBUG_FS 808 bool "Enable debug information for KVM Guests in debugfs" 809 depends on KVM_GUEST && DEBUG_FS 810 ---help--- 811 This option enables collection of various statistics for KVM guest. 812 Statistics are displayed in debugfs filesystem. Enabling this option 813 may incur significant overhead. 814 815config PARAVIRT_TIME_ACCOUNTING 816 bool "Paravirtual steal time accounting" 817 depends on PARAVIRT 818 ---help--- 819 Select this option to enable fine granularity task steal time 820 accounting. Time spent executing other tasks in parallel with 821 the current vCPU is discounted from the vCPU power. To account for 822 that, there can be a small performance impact. 823 824 If in doubt, say N here. 825 826config PARAVIRT_CLOCK 827 bool 828 829config JAILHOUSE_GUEST 830 bool "Jailhouse non-root cell support" 831 depends on X86_64 && PCI 832 select X86_PM_TIMER 833 ---help--- 834 This option allows to run Linux as guest in a Jailhouse non-root 835 cell. You can leave this option disabled if you only want to start 836 Jailhouse and run Linux afterwards in the root cell. 837 838endif #HYPERVISOR_GUEST 839 840source "arch/x86/Kconfig.cpu" 841 842config HPET_TIMER 843 def_bool X86_64 844 prompt "HPET Timer Support" if X86_32 845 ---help--- 846 Use the IA-PC HPET (High Precision Event Timer) to manage 847 time in preference to the PIT and RTC, if a HPET is 848 present. 849 HPET is the next generation timer replacing legacy 8254s. 850 The HPET provides a stable time base on SMP 851 systems, unlike the TSC, but it is more expensive to access, 852 as it is off-chip. The interface used is documented 853 in the HPET spec, revision 1. 854 855 You can safely choose Y here. However, HPET will only be 856 activated if the platform and the BIOS support this feature. 857 Otherwise the 8254 will be used for timing services. 858 859 Choose N to continue using the legacy 8254 timer. 860 861config HPET_EMULATE_RTC 862 def_bool y 863 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 864 865config APB_TIMER 866 def_bool y if X86_INTEL_MID 867 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 868 select DW_APB_TIMER 869 depends on X86_INTEL_MID && SFI 870 help 871 APB timer is the replacement for 8254, HPET on X86 MID platforms. 872 The APBT provides a stable time base on SMP 873 systems, unlike the TSC, but it is more expensive to access, 874 as it is off-chip. APB timers are always running regardless of CPU 875 C states, they are used as per CPU clockevent device when possible. 876 877# Mark as expert because too many people got it wrong. 878# The code disables itself when not needed. 879config DMI 880 default y 881 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 882 bool "Enable DMI scanning" if EXPERT 883 ---help--- 884 Enabled scanning of DMI to identify machine quirks. Say Y 885 here unless you have verified that your setup is not 886 affected by entries in the DMI blacklist. Required by PNP 887 BIOS code. 888 889config GART_IOMMU 890 bool "Old AMD GART IOMMU support" 891 select IOMMU_HELPER 892 select SWIOTLB 893 depends on X86_64 && PCI && AMD_NB 894 ---help--- 895 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 896 GART based hardware IOMMUs. 897 898 The GART supports full DMA access for devices with 32-bit access 899 limitations, on systems with more than 3 GB. This is usually needed 900 for USB, sound, many IDE/SATA chipsets and some other devices. 901 902 Newer systems typically have a modern AMD IOMMU, supported via 903 the CONFIG_AMD_IOMMU=y config option. 904 905 In normal configurations this driver is only active when needed: 906 there's more than 3 GB of memory and the system contains a 907 32-bit limited device. 908 909 If unsure, say Y. 910 911config CALGARY_IOMMU 912 bool "IBM Calgary IOMMU support" 913 select IOMMU_HELPER 914 select SWIOTLB 915 depends on X86_64 && PCI 916 ---help--- 917 Support for hardware IOMMUs in IBM's xSeries x366 and x460 918 systems. Needed to run systems with more than 3GB of memory 919 properly with 32-bit PCI devices that do not support DAC 920 (Double Address Cycle). Calgary also supports bus level 921 isolation, where all DMAs pass through the IOMMU. This 922 prevents them from going anywhere except their intended 923 destination. This catches hard-to-find kernel bugs and 924 mis-behaving drivers and devices that do not use the DMA-API 925 properly to set up their DMA buffers. The IOMMU can be 926 turned off at boot time with the iommu=off parameter. 927 Normally the kernel will make the right choice by itself. 928 If unsure, say Y. 929 930config CALGARY_IOMMU_ENABLED_BY_DEFAULT 931 def_bool y 932 prompt "Should Calgary be enabled by default?" 933 depends on CALGARY_IOMMU 934 ---help--- 935 Should Calgary be enabled by default? if you choose 'y', Calgary 936 will be used (if it exists). If you choose 'n', Calgary will not be 937 used even if it exists. If you choose 'n' and would like to use 938 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 939 If unsure, say Y. 940 941config MAXSMP 942 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 943 depends on X86_64 && SMP && DEBUG_KERNEL 944 select CPUMASK_OFFSTACK 945 ---help--- 946 Enable maximum number of CPUS and NUMA Nodes for this architecture. 947 If unsure, say N. 948 949# 950# The maximum number of CPUs supported: 951# 952# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 953# and which can be configured interactively in the 954# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 955# 956# The ranges are different on 32-bit and 64-bit kernels, depending on 957# hardware capabilities and scalability features of the kernel. 958# 959# ( If MAXSMP is enabled we just use the highest possible value and disable 960# interactive configuration. ) 961# 962 963config NR_CPUS_RANGE_BEGIN 964 int 965 default NR_CPUS_RANGE_END if MAXSMP 966 default 1 if !SMP 967 default 2 968 969config NR_CPUS_RANGE_END 970 int 971 depends on X86_32 972 default 64 if SMP && X86_BIGSMP 973 default 8 if SMP && !X86_BIGSMP 974 default 1 if !SMP 975 976config NR_CPUS_RANGE_END 977 int 978 depends on X86_64 979 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 980 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 981 default 1 if !SMP 982 983config NR_CPUS_DEFAULT 984 int 985 depends on X86_32 986 default 32 if X86_BIGSMP 987 default 8 if SMP 988 default 1 if !SMP 989 990config NR_CPUS_DEFAULT 991 int 992 depends on X86_64 993 default 8192 if MAXSMP 994 default 64 if SMP 995 default 1 if !SMP 996 997config NR_CPUS 998 int "Maximum number of CPUs" if SMP && !MAXSMP 999 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1000 default NR_CPUS_DEFAULT 1001 ---help--- 1002 This allows you to specify the maximum number of CPUs which this 1003 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1004 supported value is 8192, otherwise the maximum value is 512. The 1005 minimum value which makes sense is 2. 1006 1007 This is purely to save memory: each supported CPU adds about 8KB 1008 to the kernel image. 1009 1010config SCHED_SMT 1011 def_bool y if SMP 1012 1013config SCHED_MC 1014 def_bool y 1015 prompt "Multi-core scheduler support" 1016 depends on SMP 1017 ---help--- 1018 Multi-core scheduler support improves the CPU scheduler's decision 1019 making when dealing with multi-core CPU chips at a cost of slightly 1020 increased overhead in some places. If unsure say N here. 1021 1022config SCHED_MC_PRIO 1023 bool "CPU core priorities scheduler support" 1024 depends on SCHED_MC && CPU_SUP_INTEL 1025 select X86_INTEL_PSTATE 1026 select CPU_FREQ 1027 default y 1028 ---help--- 1029 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1030 core ordering determined at manufacturing time, which allows 1031 certain cores to reach higher turbo frequencies (when running 1032 single threaded workloads) than others. 1033 1034 Enabling this kernel feature teaches the scheduler about 1035 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1036 scheduler's CPU selection logic accordingly, so that higher 1037 overall system performance can be achieved. 1038 1039 This feature will have no effect on CPUs without this feature. 1040 1041 If unsure say Y here. 1042 1043config UP_LATE_INIT 1044 def_bool y 1045 depends on !SMP && X86_LOCAL_APIC 1046 1047config X86_UP_APIC 1048 bool "Local APIC support on uniprocessors" if !PCI_MSI 1049 default PCI_MSI 1050 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1051 ---help--- 1052 A local APIC (Advanced Programmable Interrupt Controller) is an 1053 integrated interrupt controller in the CPU. If you have a single-CPU 1054 system which has a processor with a local APIC, you can say Y here to 1055 enable and use it. If you say Y here even though your machine doesn't 1056 have a local APIC, then the kernel will still run with no slowdown at 1057 all. The local APIC supports CPU-generated self-interrupts (timer, 1058 performance counters), and the NMI watchdog which detects hard 1059 lockups. 1060 1061config X86_UP_IOAPIC 1062 bool "IO-APIC support on uniprocessors" 1063 depends on X86_UP_APIC 1064 ---help--- 1065 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1066 SMP-capable replacement for PC-style interrupt controllers. Most 1067 SMP systems and many recent uniprocessor systems have one. 1068 1069 If you have a single-CPU system with an IO-APIC, you can say Y here 1070 to use it. If you say Y here even though your machine doesn't have 1071 an IO-APIC, then the kernel will still run with no slowdown at all. 1072 1073config X86_LOCAL_APIC 1074 def_bool y 1075 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1076 select IRQ_DOMAIN_HIERARCHY 1077 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1078 1079config X86_IO_APIC 1080 def_bool y 1081 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1082 1083config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1084 bool "Reroute for broken boot IRQs" 1085 depends on X86_IO_APIC 1086 ---help--- 1087 This option enables a workaround that fixes a source of 1088 spurious interrupts. This is recommended when threaded 1089 interrupt handling is used on systems where the generation of 1090 superfluous "boot interrupts" cannot be disabled. 1091 1092 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1093 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1094 kernel does during interrupt handling). On chipsets where this 1095 boot IRQ generation cannot be disabled, this workaround keeps 1096 the original IRQ line masked so that only the equivalent "boot 1097 IRQ" is delivered to the CPUs. The workaround also tells the 1098 kernel to set up the IRQ handler on the boot IRQ line. In this 1099 way only one interrupt is delivered to the kernel. Otherwise 1100 the spurious second interrupt may cause the kernel to bring 1101 down (vital) interrupt lines. 1102 1103 Only affects "broken" chipsets. Interrupt sharing may be 1104 increased on these systems. 1105 1106config X86_MCE 1107 bool "Machine Check / overheating reporting" 1108 select GENERIC_ALLOCATOR 1109 default y 1110 ---help--- 1111 Machine Check support allows the processor to notify the 1112 kernel if it detects a problem (e.g. overheating, data corruption). 1113 The action the kernel takes depends on the severity of the problem, 1114 ranging from warning messages to halting the machine. 1115 1116config X86_MCELOG_LEGACY 1117 bool "Support for deprecated /dev/mcelog character device" 1118 depends on X86_MCE 1119 ---help--- 1120 Enable support for /dev/mcelog which is needed by the old mcelog 1121 userspace logging daemon. Consider switching to the new generation 1122 rasdaemon solution. 1123 1124config X86_MCE_INTEL 1125 def_bool y 1126 prompt "Intel MCE features" 1127 depends on X86_MCE && X86_LOCAL_APIC 1128 ---help--- 1129 Additional support for intel specific MCE features such as 1130 the thermal monitor. 1131 1132config X86_MCE_AMD 1133 def_bool y 1134 prompt "AMD MCE features" 1135 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1136 ---help--- 1137 Additional support for AMD specific MCE features such as 1138 the DRAM Error Threshold. 1139 1140config X86_ANCIENT_MCE 1141 bool "Support for old Pentium 5 / WinChip machine checks" 1142 depends on X86_32 && X86_MCE 1143 ---help--- 1144 Include support for machine check handling on old Pentium 5 or WinChip 1145 systems. These typically need to be enabled explicitly on the command 1146 line. 1147 1148config X86_MCE_THRESHOLD 1149 depends on X86_MCE_AMD || X86_MCE_INTEL 1150 def_bool y 1151 1152config X86_MCE_INJECT 1153 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1154 tristate "Machine check injector support" 1155 ---help--- 1156 Provide support for injecting machine checks for testing purposes. 1157 If you don't know what a machine check is and you don't do kernel 1158 QA it is safe to say n. 1159 1160config X86_THERMAL_VECTOR 1161 def_bool y 1162 depends on X86_MCE_INTEL 1163 1164source "arch/x86/events/Kconfig" 1165 1166config X86_LEGACY_VM86 1167 bool "Legacy VM86 support" 1168 depends on X86_32 1169 ---help--- 1170 This option allows user programs to put the CPU into V8086 1171 mode, which is an 80286-era approximation of 16-bit real mode. 1172 1173 Some very old versions of X and/or vbetool require this option 1174 for user mode setting. Similarly, DOSEMU will use it if 1175 available to accelerate real mode DOS programs. However, any 1176 recent version of DOSEMU, X, or vbetool should be fully 1177 functional even without kernel VM86 support, as they will all 1178 fall back to software emulation. Nevertheless, if you are using 1179 a 16-bit DOS program where 16-bit performance matters, vm86 1180 mode might be faster than emulation and you might want to 1181 enable this option. 1182 1183 Note that any app that works on a 64-bit kernel is unlikely to 1184 need this option, as 64-bit kernels don't, and can't, support 1185 V8086 mode. This option is also unrelated to 16-bit protected 1186 mode and is not needed to run most 16-bit programs under Wine. 1187 1188 Enabling this option increases the complexity of the kernel 1189 and slows down exception handling a tiny bit. 1190 1191 If unsure, say N here. 1192 1193config VM86 1194 bool 1195 default X86_LEGACY_VM86 1196 1197config X86_16BIT 1198 bool "Enable support for 16-bit segments" if EXPERT 1199 default y 1200 depends on MODIFY_LDT_SYSCALL 1201 ---help--- 1202 This option is required by programs like Wine to run 16-bit 1203 protected mode legacy code on x86 processors. Disabling 1204 this option saves about 300 bytes on i386, or around 6K text 1205 plus 16K runtime memory on x86-64, 1206 1207config X86_ESPFIX32 1208 def_bool y 1209 depends on X86_16BIT && X86_32 1210 1211config X86_ESPFIX64 1212 def_bool y 1213 depends on X86_16BIT && X86_64 1214 1215config X86_VSYSCALL_EMULATION 1216 bool "Enable vsyscall emulation" if EXPERT 1217 default y 1218 depends on X86_64 1219 ---help--- 1220 This enables emulation of the legacy vsyscall page. Disabling 1221 it is roughly equivalent to booting with vsyscall=none, except 1222 that it will also disable the helpful warning if a program 1223 tries to use a vsyscall. With this option set to N, offending 1224 programs will just segfault, citing addresses of the form 1225 0xffffffffff600?00. 1226 1227 This option is required by many programs built before 2013, and 1228 care should be used even with newer programs if set to N. 1229 1230 Disabling this option saves about 7K of kernel size and 1231 possibly 4K of additional runtime pagetable memory. 1232 1233config TOSHIBA 1234 tristate "Toshiba Laptop support" 1235 depends on X86_32 1236 ---help--- 1237 This adds a driver to safely access the System Management Mode of 1238 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1239 not work on models with a Phoenix BIOS. The System Management Mode 1240 is used to set the BIOS and power saving options on Toshiba portables. 1241 1242 For information on utilities to make use of this driver see the 1243 Toshiba Linux utilities web site at: 1244 <http://www.buzzard.org.uk/toshiba/>. 1245 1246 Say Y if you intend to run this kernel on a Toshiba portable. 1247 Say N otherwise. 1248 1249config I8K 1250 tristate "Dell i8k legacy laptop support" 1251 select HWMON 1252 select SENSORS_DELL_SMM 1253 ---help--- 1254 This option enables legacy /proc/i8k userspace interface in hwmon 1255 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1256 temperature and allows controlling fan speeds of Dell laptops via 1257 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1258 it reports also power and hotkey status. For fan speed control is 1259 needed userspace package i8kutils. 1260 1261 Say Y if you intend to run this kernel on old Dell laptops or want to 1262 use userspace package i8kutils. 1263 Say N otherwise. 1264 1265config X86_REBOOTFIXUPS 1266 bool "Enable X86 board specific fixups for reboot" 1267 depends on X86_32 1268 ---help--- 1269 This enables chipset and/or board specific fixups to be done 1270 in order to get reboot to work correctly. This is only needed on 1271 some combinations of hardware and BIOS. The symptom, for which 1272 this config is intended, is when reboot ends with a stalled/hung 1273 system. 1274 1275 Currently, the only fixup is for the Geode machines using 1276 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1277 1278 Say Y if you want to enable the fixup. Currently, it's safe to 1279 enable this option even if you don't need it. 1280 Say N otherwise. 1281 1282config MICROCODE 1283 bool "CPU microcode loading support" 1284 default y 1285 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1286 select FW_LOADER 1287 ---help--- 1288 If you say Y here, you will be able to update the microcode on 1289 Intel and AMD processors. The Intel support is for the IA32 family, 1290 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1291 AMD support is for families 0x10 and later. You will obviously need 1292 the actual microcode binary data itself which is not shipped with 1293 the Linux kernel. 1294 1295 The preferred method to load microcode from a detached initrd is described 1296 in Documentation/x86/microcode.txt. For that you need to enable 1297 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1298 initrd for microcode blobs. 1299 1300 In addition, you can build the microcode into the kernel. For that you 1301 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1302 config option. 1303 1304config MICROCODE_INTEL 1305 bool "Intel microcode loading support" 1306 depends on MICROCODE 1307 default MICROCODE 1308 select FW_LOADER 1309 ---help--- 1310 This options enables microcode patch loading support for Intel 1311 processors. 1312 1313 For the current Intel microcode data package go to 1314 <https://downloadcenter.intel.com> and search for 1315 'Linux Processor Microcode Data File'. 1316 1317config MICROCODE_AMD 1318 bool "AMD microcode loading support" 1319 depends on MICROCODE 1320 select FW_LOADER 1321 ---help--- 1322 If you select this option, microcode patch loading support for AMD 1323 processors will be enabled. 1324 1325config MICROCODE_OLD_INTERFACE 1326 bool "Ancient loading interface (DEPRECATED)" 1327 default n 1328 depends on MICROCODE 1329 ---help--- 1330 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1331 which was used by userspace tools like iucode_tool and microcode.ctl. 1332 It is inadequate because it runs too late to be able to properly 1333 load microcode on a machine and it needs special tools. Instead, you 1334 should've switched to the early loading method with the initrd or 1335 builtin microcode by now: Documentation/x86/microcode.txt 1336 1337config X86_MSR 1338 tristate "/dev/cpu/*/msr - Model-specific register support" 1339 ---help--- 1340 This device gives privileged processes access to the x86 1341 Model-Specific Registers (MSRs). It is a character device with 1342 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1343 MSR accesses are directed to a specific CPU on multi-processor 1344 systems. 1345 1346config X86_CPUID 1347 tristate "/dev/cpu/*/cpuid - CPU information support" 1348 ---help--- 1349 This device gives processes access to the x86 CPUID instruction to 1350 be executed on a specific processor. It is a character device 1351 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1352 /dev/cpu/31/cpuid. 1353 1354choice 1355 prompt "High Memory Support" 1356 default HIGHMEM4G 1357 depends on X86_32 1358 1359config NOHIGHMEM 1360 bool "off" 1361 ---help--- 1362 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1363 However, the address space of 32-bit x86 processors is only 4 1364 Gigabytes large. That means that, if you have a large amount of 1365 physical memory, not all of it can be "permanently mapped" by the 1366 kernel. The physical memory that's not permanently mapped is called 1367 "high memory". 1368 1369 If you are compiling a kernel which will never run on a machine with 1370 more than 1 Gigabyte total physical RAM, answer "off" here (default 1371 choice and suitable for most users). This will result in a "3GB/1GB" 1372 split: 3GB are mapped so that each process sees a 3GB virtual memory 1373 space and the remaining part of the 4GB virtual memory space is used 1374 by the kernel to permanently map as much physical memory as 1375 possible. 1376 1377 If the machine has between 1 and 4 Gigabytes physical RAM, then 1378 answer "4GB" here. 1379 1380 If more than 4 Gigabytes is used then answer "64GB" here. This 1381 selection turns Intel PAE (Physical Address Extension) mode on. 1382 PAE implements 3-level paging on IA32 processors. PAE is fully 1383 supported by Linux, PAE mode is implemented on all recent Intel 1384 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1385 then the kernel will not boot on CPUs that don't support PAE! 1386 1387 The actual amount of total physical memory will either be 1388 auto detected or can be forced by using a kernel command line option 1389 such as "mem=256M". (Try "man bootparam" or see the documentation of 1390 your boot loader (lilo or loadlin) about how to pass options to the 1391 kernel at boot time.) 1392 1393 If unsure, say "off". 1394 1395config HIGHMEM4G 1396 bool "4GB" 1397 ---help--- 1398 Select this if you have a 32-bit processor and between 1 and 4 1399 gigabytes of physical RAM. 1400 1401config HIGHMEM64G 1402 bool "64GB" 1403 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1404 select X86_PAE 1405 ---help--- 1406 Select this if you have a 32-bit processor and more than 4 1407 gigabytes of physical RAM. 1408 1409endchoice 1410 1411choice 1412 prompt "Memory split" if EXPERT 1413 default VMSPLIT_3G 1414 depends on X86_32 1415 ---help--- 1416 Select the desired split between kernel and user memory. 1417 1418 If the address range available to the kernel is less than the 1419 physical memory installed, the remaining memory will be available 1420 as "high memory". Accessing high memory is a little more costly 1421 than low memory, as it needs to be mapped into the kernel first. 1422 Note that increasing the kernel address space limits the range 1423 available to user programs, making the address space there 1424 tighter. Selecting anything other than the default 3G/1G split 1425 will also likely make your kernel incompatible with binary-only 1426 kernel modules. 1427 1428 If you are not absolutely sure what you are doing, leave this 1429 option alone! 1430 1431 config VMSPLIT_3G 1432 bool "3G/1G user/kernel split" 1433 config VMSPLIT_3G_OPT 1434 depends on !X86_PAE 1435 bool "3G/1G user/kernel split (for full 1G low memory)" 1436 config VMSPLIT_2G 1437 bool "2G/2G user/kernel split" 1438 config VMSPLIT_2G_OPT 1439 depends on !X86_PAE 1440 bool "2G/2G user/kernel split (for full 2G low memory)" 1441 config VMSPLIT_1G 1442 bool "1G/3G user/kernel split" 1443endchoice 1444 1445config PAGE_OFFSET 1446 hex 1447 default 0xB0000000 if VMSPLIT_3G_OPT 1448 default 0x80000000 if VMSPLIT_2G 1449 default 0x78000000 if VMSPLIT_2G_OPT 1450 default 0x40000000 if VMSPLIT_1G 1451 default 0xC0000000 1452 depends on X86_32 1453 1454config HIGHMEM 1455 def_bool y 1456 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1457 1458config X86_PAE 1459 bool "PAE (Physical Address Extension) Support" 1460 depends on X86_32 && !HIGHMEM4G 1461 select PHYS_ADDR_T_64BIT 1462 select SWIOTLB 1463 ---help--- 1464 PAE is required for NX support, and furthermore enables 1465 larger swapspace support for non-overcommit purposes. It 1466 has the cost of more pagetable lookup overhead, and also 1467 consumes more pagetable space per process. 1468 1469config X86_5LEVEL 1470 bool "Enable 5-level page tables support" 1471 select DYNAMIC_MEMORY_LAYOUT 1472 select SPARSEMEM_VMEMMAP 1473 depends on X86_64 1474 ---help--- 1475 5-level paging enables access to larger address space: 1476 upto 128 PiB of virtual address space and 4 PiB of 1477 physical address space. 1478 1479 It will be supported by future Intel CPUs. 1480 1481 A kernel with the option enabled can be booted on machines that 1482 support 4- or 5-level paging. 1483 1484 See Documentation/x86/x86_64/5level-paging.txt for more 1485 information. 1486 1487 Say N if unsure. 1488 1489config X86_DIRECT_GBPAGES 1490 def_bool y 1491 depends on X86_64 && !DEBUG_PAGEALLOC 1492 ---help--- 1493 Certain kernel features effectively disable kernel 1494 linear 1 GB mappings (even if the CPU otherwise 1495 supports them), so don't confuse the user by printing 1496 that we have them enabled. 1497 1498config X86_CPA_STATISTICS 1499 bool "Enable statistic for Change Page Attribute" 1500 depends on DEBUG_FS 1501 ---help--- 1502 Expose statistics about the Change Page Attribute mechanims, which 1503 helps to determine the effectiveness of preserving large and huge 1504 page mappings when mapping protections are changed. 1505 1506config ARCH_HAS_MEM_ENCRYPT 1507 def_bool y 1508 1509config AMD_MEM_ENCRYPT 1510 bool "AMD Secure Memory Encryption (SME) support" 1511 depends on X86_64 && CPU_SUP_AMD 1512 select DYNAMIC_PHYSICAL_MASK 1513 select ARCH_USE_MEMREMAP_PROT 1514 ---help--- 1515 Say yes to enable support for the encryption of system memory. 1516 This requires an AMD processor that supports Secure Memory 1517 Encryption (SME). 1518 1519config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1520 bool "Activate AMD Secure Memory Encryption (SME) by default" 1521 default y 1522 depends on AMD_MEM_ENCRYPT 1523 ---help--- 1524 Say yes to have system memory encrypted by default if running on 1525 an AMD processor that supports Secure Memory Encryption (SME). 1526 1527 If set to Y, then the encryption of system memory can be 1528 deactivated with the mem_encrypt=off command line option. 1529 1530 If set to N, then the encryption of system memory can be 1531 activated with the mem_encrypt=on command line option. 1532 1533# Common NUMA Features 1534config NUMA 1535 bool "Numa Memory Allocation and Scheduler Support" 1536 depends on SMP 1537 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1538 default y if X86_BIGSMP 1539 ---help--- 1540 Enable NUMA (Non Uniform Memory Access) support. 1541 1542 The kernel will try to allocate memory used by a CPU on the 1543 local memory controller of the CPU and add some more 1544 NUMA awareness to the kernel. 1545 1546 For 64-bit this is recommended if the system is Intel Core i7 1547 (or later), AMD Opteron, or EM64T NUMA. 1548 1549 For 32-bit this is only needed if you boot a 32-bit 1550 kernel on a 64-bit NUMA platform. 1551 1552 Otherwise, you should say N. 1553 1554config AMD_NUMA 1555 def_bool y 1556 prompt "Old style AMD Opteron NUMA detection" 1557 depends on X86_64 && NUMA && PCI 1558 ---help--- 1559 Enable AMD NUMA node topology detection. You should say Y here if 1560 you have a multi processor AMD system. This uses an old method to 1561 read the NUMA configuration directly from the builtin Northbridge 1562 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1563 which also takes priority if both are compiled in. 1564 1565config X86_64_ACPI_NUMA 1566 def_bool y 1567 prompt "ACPI NUMA detection" 1568 depends on X86_64 && NUMA && ACPI && PCI 1569 select ACPI_NUMA 1570 ---help--- 1571 Enable ACPI SRAT based node topology detection. 1572 1573# Some NUMA nodes have memory ranges that span 1574# other nodes. Even though a pfn is valid and 1575# between a node's start and end pfns, it may not 1576# reside on that node. See memmap_init_zone() 1577# for details. 1578config NODES_SPAN_OTHER_NODES 1579 def_bool y 1580 depends on X86_64_ACPI_NUMA 1581 1582config NUMA_EMU 1583 bool "NUMA emulation" 1584 depends on NUMA 1585 ---help--- 1586 Enable NUMA emulation. A flat machine will be split 1587 into virtual nodes when booted with "numa=fake=N", where N is the 1588 number of nodes. This is only useful for debugging. 1589 1590config NODES_SHIFT 1591 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1592 range 1 10 1593 default "10" if MAXSMP 1594 default "6" if X86_64 1595 default "3" 1596 depends on NEED_MULTIPLE_NODES 1597 ---help--- 1598 Specify the maximum number of NUMA Nodes available on the target 1599 system. Increases memory reserved to accommodate various tables. 1600 1601config ARCH_HAVE_MEMORY_PRESENT 1602 def_bool y 1603 depends on X86_32 && DISCONTIGMEM 1604 1605config ARCH_FLATMEM_ENABLE 1606 def_bool y 1607 depends on X86_32 && !NUMA 1608 1609config ARCH_DISCONTIGMEM_ENABLE 1610 def_bool n 1611 depends on NUMA && X86_32 1612 depends on BROKEN 1613 1614config ARCH_SPARSEMEM_ENABLE 1615 def_bool y 1616 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1617 select SPARSEMEM_STATIC if X86_32 1618 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1619 1620config ARCH_SPARSEMEM_DEFAULT 1621 def_bool X86_64 || (NUMA && X86_32) 1622 1623config ARCH_SELECT_MEMORY_MODEL 1624 def_bool y 1625 depends on ARCH_SPARSEMEM_ENABLE 1626 1627config ARCH_MEMORY_PROBE 1628 bool "Enable sysfs memory/probe interface" 1629 depends on X86_64 && MEMORY_HOTPLUG 1630 help 1631 This option enables a sysfs memory/probe interface for testing. 1632 See Documentation/memory-hotplug.txt for more information. 1633 If you are unsure how to answer this question, answer N. 1634 1635config ARCH_PROC_KCORE_TEXT 1636 def_bool y 1637 depends on X86_64 && PROC_KCORE 1638 1639config ILLEGAL_POINTER_VALUE 1640 hex 1641 default 0 if X86_32 1642 default 0xdead000000000000 if X86_64 1643 1644config X86_PMEM_LEGACY_DEVICE 1645 bool 1646 1647config X86_PMEM_LEGACY 1648 tristate "Support non-standard NVDIMMs and ADR protected memory" 1649 depends on PHYS_ADDR_T_64BIT 1650 depends on BLK_DEV 1651 select X86_PMEM_LEGACY_DEVICE 1652 select LIBNVDIMM 1653 help 1654 Treat memory marked using the non-standard e820 type of 12 as used 1655 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1656 The kernel will offer these regions to the 'pmem' driver so 1657 they can be used for persistent storage. 1658 1659 Say Y if unsure. 1660 1661config HIGHPTE 1662 bool "Allocate 3rd-level pagetables from highmem" 1663 depends on HIGHMEM 1664 ---help--- 1665 The VM uses one page table entry for each page of physical memory. 1666 For systems with a lot of RAM, this can be wasteful of precious 1667 low memory. Setting this option will put user-space page table 1668 entries in high memory. 1669 1670config X86_CHECK_BIOS_CORRUPTION 1671 bool "Check for low memory corruption" 1672 ---help--- 1673 Periodically check for memory corruption in low memory, which 1674 is suspected to be caused by BIOS. Even when enabled in the 1675 configuration, it is disabled at runtime. Enable it by 1676 setting "memory_corruption_check=1" on the kernel command 1677 line. By default it scans the low 64k of memory every 60 1678 seconds; see the memory_corruption_check_size and 1679 memory_corruption_check_period parameters in 1680 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1681 1682 When enabled with the default parameters, this option has 1683 almost no overhead, as it reserves a relatively small amount 1684 of memory and scans it infrequently. It both detects corruption 1685 and prevents it from affecting the running system. 1686 1687 It is, however, intended as a diagnostic tool; if repeatable 1688 BIOS-originated corruption always affects the same memory, 1689 you can use memmap= to prevent the kernel from using that 1690 memory. 1691 1692config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1693 bool "Set the default setting of memory_corruption_check" 1694 depends on X86_CHECK_BIOS_CORRUPTION 1695 default y 1696 ---help--- 1697 Set whether the default state of memory_corruption_check is 1698 on or off. 1699 1700config X86_RESERVE_LOW 1701 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1702 default 64 1703 range 4 640 1704 ---help--- 1705 Specify the amount of low memory to reserve for the BIOS. 1706 1707 The first page contains BIOS data structures that the kernel 1708 must not use, so that page must always be reserved. 1709 1710 By default we reserve the first 64K of physical RAM, as a 1711 number of BIOSes are known to corrupt that memory range 1712 during events such as suspend/resume or monitor cable 1713 insertion, so it must not be used by the kernel. 1714 1715 You can set this to 4 if you are absolutely sure that you 1716 trust the BIOS to get all its memory reservations and usages 1717 right. If you know your BIOS have problems beyond the 1718 default 64K area, you can set this to 640 to avoid using the 1719 entire low memory range. 1720 1721 If you have doubts about the BIOS (e.g. suspend/resume does 1722 not work or there's kernel crashes after certain hardware 1723 hotplug events) then you might want to enable 1724 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1725 typical corruption patterns. 1726 1727 Leave this to the default value of 64 if you are unsure. 1728 1729config MATH_EMULATION 1730 bool 1731 depends on MODIFY_LDT_SYSCALL 1732 prompt "Math emulation" if X86_32 1733 ---help--- 1734 Linux can emulate a math coprocessor (used for floating point 1735 operations) if you don't have one. 486DX and Pentium processors have 1736 a math coprocessor built in, 486SX and 386 do not, unless you added 1737 a 487DX or 387, respectively. (The messages during boot time can 1738 give you some hints here ["man dmesg"].) Everyone needs either a 1739 coprocessor or this emulation. 1740 1741 If you don't have a math coprocessor, you need to say Y here; if you 1742 say Y here even though you have a coprocessor, the coprocessor will 1743 be used nevertheless. (This behavior can be changed with the kernel 1744 command line option "no387", which comes handy if your coprocessor 1745 is broken. Try "man bootparam" or see the documentation of your boot 1746 loader (lilo or loadlin) about how to pass options to the kernel at 1747 boot time.) This means that it is a good idea to say Y here if you 1748 intend to use this kernel on different machines. 1749 1750 More information about the internals of the Linux math coprocessor 1751 emulation can be found in <file:arch/x86/math-emu/README>. 1752 1753 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1754 kernel, it won't hurt. 1755 1756config MTRR 1757 def_bool y 1758 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1759 ---help--- 1760 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1761 the Memory Type Range Registers (MTRRs) may be used to control 1762 processor access to memory ranges. This is most useful if you have 1763 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1764 allows bus write transfers to be combined into a larger transfer 1765 before bursting over the PCI/AGP bus. This can increase performance 1766 of image write operations 2.5 times or more. Saying Y here creates a 1767 /proc/mtrr file which may be used to manipulate your processor's 1768 MTRRs. Typically the X server should use this. 1769 1770 This code has a reasonably generic interface so that similar 1771 control registers on other processors can be easily supported 1772 as well: 1773 1774 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1775 Registers (ARRs) which provide a similar functionality to MTRRs. For 1776 these, the ARRs are used to emulate the MTRRs. 1777 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1778 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1779 write-combining. All of these processors are supported by this code 1780 and it makes sense to say Y here if you have one of them. 1781 1782 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1783 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1784 can lead to all sorts of problems, so it's good to say Y here. 1785 1786 You can safely say Y even if your machine doesn't have MTRRs, you'll 1787 just add about 9 KB to your kernel. 1788 1789 See <file:Documentation/x86/mtrr.txt> for more information. 1790 1791config MTRR_SANITIZER 1792 def_bool y 1793 prompt "MTRR cleanup support" 1794 depends on MTRR 1795 ---help--- 1796 Convert MTRR layout from continuous to discrete, so X drivers can 1797 add writeback entries. 1798 1799 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1800 The largest mtrr entry size for a continuous block can be set with 1801 mtrr_chunk_size. 1802 1803 If unsure, say Y. 1804 1805config MTRR_SANITIZER_ENABLE_DEFAULT 1806 int "MTRR cleanup enable value (0-1)" 1807 range 0 1 1808 default "0" 1809 depends on MTRR_SANITIZER 1810 ---help--- 1811 Enable mtrr cleanup default value 1812 1813config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1814 int "MTRR cleanup spare reg num (0-7)" 1815 range 0 7 1816 default "1" 1817 depends on MTRR_SANITIZER 1818 ---help--- 1819 mtrr cleanup spare entries default, it can be changed via 1820 mtrr_spare_reg_nr=N on the kernel command line. 1821 1822config X86_PAT 1823 def_bool y 1824 prompt "x86 PAT support" if EXPERT 1825 depends on MTRR 1826 ---help--- 1827 Use PAT attributes to setup page level cache control. 1828 1829 PATs are the modern equivalents of MTRRs and are much more 1830 flexible than MTRRs. 1831 1832 Say N here if you see bootup problems (boot crash, boot hang, 1833 spontaneous reboots) or a non-working video driver. 1834 1835 If unsure, say Y. 1836 1837config ARCH_USES_PG_UNCACHED 1838 def_bool y 1839 depends on X86_PAT 1840 1841config ARCH_RANDOM 1842 def_bool y 1843 prompt "x86 architectural random number generator" if EXPERT 1844 ---help--- 1845 Enable the x86 architectural RDRAND instruction 1846 (Intel Bull Mountain technology) to generate random numbers. 1847 If supported, this is a high bandwidth, cryptographically 1848 secure hardware random number generator. 1849 1850config X86_SMAP 1851 def_bool y 1852 prompt "Supervisor Mode Access Prevention" if EXPERT 1853 ---help--- 1854 Supervisor Mode Access Prevention (SMAP) is a security 1855 feature in newer Intel processors. There is a small 1856 performance cost if this enabled and turned on; there is 1857 also a small increase in the kernel size if this is enabled. 1858 1859 If unsure, say Y. 1860 1861config X86_INTEL_UMIP 1862 def_bool y 1863 depends on CPU_SUP_INTEL 1864 prompt "Intel User Mode Instruction Prevention" if EXPERT 1865 ---help--- 1866 The User Mode Instruction Prevention (UMIP) is a security 1867 feature in newer Intel processors. If enabled, a general 1868 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1869 or STR instructions are executed in user mode. These instructions 1870 unnecessarily expose information about the hardware state. 1871 1872 The vast majority of applications do not use these instructions. 1873 For the very few that do, software emulation is provided in 1874 specific cases in protected and virtual-8086 modes. Emulated 1875 results are dummy. 1876 1877config X86_INTEL_MPX 1878 prompt "Intel MPX (Memory Protection Extensions)" 1879 def_bool n 1880 # Note: only available in 64-bit mode due to VMA flags shortage 1881 depends on CPU_SUP_INTEL && X86_64 1882 select ARCH_USES_HIGH_VMA_FLAGS 1883 ---help--- 1884 MPX provides hardware features that can be used in 1885 conjunction with compiler-instrumented code to check 1886 memory references. It is designed to detect buffer 1887 overflow or underflow bugs. 1888 1889 This option enables running applications which are 1890 instrumented or otherwise use MPX. It does not use MPX 1891 itself inside the kernel or to protect the kernel 1892 against bad memory references. 1893 1894 Enabling this option will make the kernel larger: 1895 ~8k of kernel text and 36 bytes of data on a 64-bit 1896 defconfig. It adds a long to the 'mm_struct' which 1897 will increase the kernel memory overhead of each 1898 process and adds some branches to paths used during 1899 exec() and munmap(). 1900 1901 For details, see Documentation/x86/intel_mpx.txt 1902 1903 If unsure, say N. 1904 1905config X86_INTEL_MEMORY_PROTECTION_KEYS 1906 prompt "Intel Memory Protection Keys" 1907 def_bool y 1908 # Note: only available in 64-bit mode 1909 depends on CPU_SUP_INTEL && X86_64 1910 select ARCH_USES_HIGH_VMA_FLAGS 1911 select ARCH_HAS_PKEYS 1912 ---help--- 1913 Memory Protection Keys provides a mechanism for enforcing 1914 page-based protections, but without requiring modification of the 1915 page tables when an application changes protection domains. 1916 1917 For details, see Documentation/x86/protection-keys.txt 1918 1919 If unsure, say y. 1920 1921config EFI 1922 bool "EFI runtime service support" 1923 depends on ACPI 1924 select UCS2_STRING 1925 select EFI_RUNTIME_WRAPPERS 1926 ---help--- 1927 This enables the kernel to use EFI runtime services that are 1928 available (such as the EFI variable services). 1929 1930 This option is only useful on systems that have EFI firmware. 1931 In addition, you should use the latest ELILO loader available 1932 at <http://elilo.sourceforge.net> in order to take advantage 1933 of EFI runtime services. However, even with this option, the 1934 resultant kernel should continue to boot on existing non-EFI 1935 platforms. 1936 1937config EFI_STUB 1938 bool "EFI stub support" 1939 depends on EFI && !X86_USE_3DNOW 1940 select RELOCATABLE 1941 ---help--- 1942 This kernel feature allows a bzImage to be loaded directly 1943 by EFI firmware without the use of a bootloader. 1944 1945 See Documentation/efi-stub.txt for more information. 1946 1947config EFI_MIXED 1948 bool "EFI mixed-mode support" 1949 depends on EFI_STUB && X86_64 1950 ---help--- 1951 Enabling this feature allows a 64-bit kernel to be booted 1952 on a 32-bit firmware, provided that your CPU supports 64-bit 1953 mode. 1954 1955 Note that it is not possible to boot a mixed-mode enabled 1956 kernel via the EFI boot stub - a bootloader that supports 1957 the EFI handover protocol must be used. 1958 1959 If unsure, say N. 1960 1961config SECCOMP 1962 def_bool y 1963 prompt "Enable seccomp to safely compute untrusted bytecode" 1964 ---help--- 1965 This kernel feature is useful for number crunching applications 1966 that may need to compute untrusted bytecode during their 1967 execution. By using pipes or other transports made available to 1968 the process as file descriptors supporting the read/write 1969 syscalls, it's possible to isolate those applications in 1970 their own address space using seccomp. Once seccomp is 1971 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1972 and the task is only allowed to execute a few safe syscalls 1973 defined by each seccomp mode. 1974 1975 If unsure, say Y. Only embedded should say N here. 1976 1977source "kernel/Kconfig.hz" 1978 1979config KEXEC 1980 bool "kexec system call" 1981 select KEXEC_CORE 1982 ---help--- 1983 kexec is a system call that implements the ability to shutdown your 1984 current kernel, and to start another kernel. It is like a reboot 1985 but it is independent of the system firmware. And like a reboot 1986 you can start any kernel with it, not just Linux. 1987 1988 The name comes from the similarity to the exec system call. 1989 1990 It is an ongoing process to be certain the hardware in a machine 1991 is properly shutdown, so do not be surprised if this code does not 1992 initially work for you. As of this writing the exact hardware 1993 interface is strongly in flux, so no good recommendation can be 1994 made. 1995 1996config KEXEC_FILE 1997 bool "kexec file based system call" 1998 select KEXEC_CORE 1999 select BUILD_BIN2C 2000 depends on X86_64 2001 depends on CRYPTO=y 2002 depends on CRYPTO_SHA256=y 2003 ---help--- 2004 This is new version of kexec system call. This system call is 2005 file based and takes file descriptors as system call argument 2006 for kernel and initramfs as opposed to list of segments as 2007 accepted by previous system call. 2008 2009config ARCH_HAS_KEXEC_PURGATORY 2010 def_bool KEXEC_FILE 2011 2012config KEXEC_VERIFY_SIG 2013 bool "Verify kernel signature during kexec_file_load() syscall" 2014 depends on KEXEC_FILE 2015 ---help--- 2016 This option makes kernel signature verification mandatory for 2017 the kexec_file_load() syscall. 2018 2019 In addition to that option, you need to enable signature 2020 verification for the corresponding kernel image type being 2021 loaded in order for this to work. 2022 2023config KEXEC_BZIMAGE_VERIFY_SIG 2024 bool "Enable bzImage signature verification support" 2025 depends on KEXEC_VERIFY_SIG 2026 depends on SIGNED_PE_FILE_VERIFICATION 2027 select SYSTEM_TRUSTED_KEYRING 2028 ---help--- 2029 Enable bzImage signature verification support. 2030 2031config CRASH_DUMP 2032 bool "kernel crash dumps" 2033 depends on X86_64 || (X86_32 && HIGHMEM) 2034 ---help--- 2035 Generate crash dump after being started by kexec. 2036 This should be normally only set in special crash dump kernels 2037 which are loaded in the main kernel with kexec-tools into 2038 a specially reserved region and then later executed after 2039 a crash by kdump/kexec. The crash dump kernel must be compiled 2040 to a memory address not used by the main kernel or BIOS using 2041 PHYSICAL_START, or it must be built as a relocatable image 2042 (CONFIG_RELOCATABLE=y). 2043 For more details see Documentation/kdump/kdump.txt 2044 2045config KEXEC_JUMP 2046 bool "kexec jump" 2047 depends on KEXEC && HIBERNATION 2048 ---help--- 2049 Jump between original kernel and kexeced kernel and invoke 2050 code in physical address mode via KEXEC 2051 2052config PHYSICAL_START 2053 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2054 default "0x1000000" 2055 ---help--- 2056 This gives the physical address where the kernel is loaded. 2057 2058 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2059 bzImage will decompress itself to above physical address and 2060 run from there. Otherwise, bzImage will run from the address where 2061 it has been loaded by the boot loader and will ignore above physical 2062 address. 2063 2064 In normal kdump cases one does not have to set/change this option 2065 as now bzImage can be compiled as a completely relocatable image 2066 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2067 address. This option is mainly useful for the folks who don't want 2068 to use a bzImage for capturing the crash dump and want to use a 2069 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2070 to be specifically compiled to run from a specific memory area 2071 (normally a reserved region) and this option comes handy. 2072 2073 So if you are using bzImage for capturing the crash dump, 2074 leave the value here unchanged to 0x1000000 and set 2075 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2076 for capturing the crash dump change this value to start of 2077 the reserved region. In other words, it can be set based on 2078 the "X" value as specified in the "crashkernel=YM@XM" 2079 command line boot parameter passed to the panic-ed 2080 kernel. Please take a look at Documentation/kdump/kdump.txt 2081 for more details about crash dumps. 2082 2083 Usage of bzImage for capturing the crash dump is recommended as 2084 one does not have to build two kernels. Same kernel can be used 2085 as production kernel and capture kernel. Above option should have 2086 gone away after relocatable bzImage support is introduced. But it 2087 is present because there are users out there who continue to use 2088 vmlinux for dump capture. This option should go away down the 2089 line. 2090 2091 Don't change this unless you know what you are doing. 2092 2093config RELOCATABLE 2094 bool "Build a relocatable kernel" 2095 default y 2096 ---help--- 2097 This builds a kernel image that retains relocation information 2098 so it can be loaded someplace besides the default 1MB. 2099 The relocations tend to make the kernel binary about 10% larger, 2100 but are discarded at runtime. 2101 2102 One use is for the kexec on panic case where the recovery kernel 2103 must live at a different physical address than the primary 2104 kernel. 2105 2106 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2107 it has been loaded at and the compile time physical address 2108 (CONFIG_PHYSICAL_START) is used as the minimum location. 2109 2110config RANDOMIZE_BASE 2111 bool "Randomize the address of the kernel image (KASLR)" 2112 depends on RELOCATABLE 2113 default y 2114 ---help--- 2115 In support of Kernel Address Space Layout Randomization (KASLR), 2116 this randomizes the physical address at which the kernel image 2117 is decompressed and the virtual address where the kernel 2118 image is mapped, as a security feature that deters exploit 2119 attempts relying on knowledge of the location of kernel 2120 code internals. 2121 2122 On 64-bit, the kernel physical and virtual addresses are 2123 randomized separately. The physical address will be anywhere 2124 between 16MB and the top of physical memory (up to 64TB). The 2125 virtual address will be randomized from 16MB up to 1GB (9 bits 2126 of entropy). Note that this also reduces the memory space 2127 available to kernel modules from 1.5GB to 1GB. 2128 2129 On 32-bit, the kernel physical and virtual addresses are 2130 randomized together. They will be randomized from 16MB up to 2131 512MB (8 bits of entropy). 2132 2133 Entropy is generated using the RDRAND instruction if it is 2134 supported. If RDTSC is supported, its value is mixed into 2135 the entropy pool as well. If neither RDRAND nor RDTSC are 2136 supported, then entropy is read from the i8254 timer. The 2137 usable entropy is limited by the kernel being built using 2138 2GB addressing, and that PHYSICAL_ALIGN must be at a 2139 minimum of 2MB. As a result, only 10 bits of entropy are 2140 theoretically possible, but the implementations are further 2141 limited due to memory layouts. 2142 2143 If unsure, say Y. 2144 2145# Relocation on x86 needs some additional build support 2146config X86_NEED_RELOCS 2147 def_bool y 2148 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2149 2150config PHYSICAL_ALIGN 2151 hex "Alignment value to which kernel should be aligned" 2152 default "0x200000" 2153 range 0x2000 0x1000000 if X86_32 2154 range 0x200000 0x1000000 if X86_64 2155 ---help--- 2156 This value puts the alignment restrictions on physical address 2157 where kernel is loaded and run from. Kernel is compiled for an 2158 address which meets above alignment restriction. 2159 2160 If bootloader loads the kernel at a non-aligned address and 2161 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2162 address aligned to above value and run from there. 2163 2164 If bootloader loads the kernel at a non-aligned address and 2165 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2166 load address and decompress itself to the address it has been 2167 compiled for and run from there. The address for which kernel is 2168 compiled already meets above alignment restrictions. Hence the 2169 end result is that kernel runs from a physical address meeting 2170 above alignment restrictions. 2171 2172 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2173 this value must be a multiple of 0x200000. 2174 2175 Don't change this unless you know what you are doing. 2176 2177config DYNAMIC_MEMORY_LAYOUT 2178 bool 2179 ---help--- 2180 This option makes base addresses of vmalloc and vmemmap as well as 2181 __PAGE_OFFSET movable during boot. 2182 2183config RANDOMIZE_MEMORY 2184 bool "Randomize the kernel memory sections" 2185 depends on X86_64 2186 depends on RANDOMIZE_BASE 2187 select DYNAMIC_MEMORY_LAYOUT 2188 default RANDOMIZE_BASE 2189 ---help--- 2190 Randomizes the base virtual address of kernel memory sections 2191 (physical memory mapping, vmalloc & vmemmap). This security feature 2192 makes exploits relying on predictable memory locations less reliable. 2193 2194 The order of allocations remains unchanged. Entropy is generated in 2195 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2196 configuration have in average 30,000 different possible virtual 2197 addresses for each memory section. 2198 2199 If unsure, say Y. 2200 2201config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2202 hex "Physical memory mapping padding" if EXPERT 2203 depends on RANDOMIZE_MEMORY 2204 default "0xa" if MEMORY_HOTPLUG 2205 default "0x0" 2206 range 0x1 0x40 if MEMORY_HOTPLUG 2207 range 0x0 0x40 2208 ---help--- 2209 Define the padding in terabytes added to the existing physical 2210 memory size during kernel memory randomization. It is useful 2211 for memory hotplug support but reduces the entropy available for 2212 address randomization. 2213 2214 If unsure, leave at the default value. 2215 2216config HOTPLUG_CPU 2217 def_bool y 2218 depends on SMP 2219 2220config BOOTPARAM_HOTPLUG_CPU0 2221 bool "Set default setting of cpu0_hotpluggable" 2222 depends on HOTPLUG_CPU 2223 ---help--- 2224 Set whether default state of cpu0_hotpluggable is on or off. 2225 2226 Say Y here to enable CPU0 hotplug by default. If this switch 2227 is turned on, there is no need to give cpu0_hotplug kernel 2228 parameter and the CPU0 hotplug feature is enabled by default. 2229 2230 Please note: there are two known CPU0 dependencies if you want 2231 to enable the CPU0 hotplug feature either by this switch or by 2232 cpu0_hotplug kernel parameter. 2233 2234 First, resume from hibernate or suspend always starts from CPU0. 2235 So hibernate and suspend are prevented if CPU0 is offline. 2236 2237 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2238 offline if any interrupt can not migrate out of CPU0. There may 2239 be other CPU0 dependencies. 2240 2241 Please make sure the dependencies are under your control before 2242 you enable this feature. 2243 2244 Say N if you don't want to enable CPU0 hotplug feature by default. 2245 You still can enable the CPU0 hotplug feature at boot by kernel 2246 parameter cpu0_hotplug. 2247 2248config DEBUG_HOTPLUG_CPU0 2249 def_bool n 2250 prompt "Debug CPU0 hotplug" 2251 depends on HOTPLUG_CPU 2252 ---help--- 2253 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2254 soon as possible and boots up userspace with CPU0 offlined. User 2255 can online CPU0 back after boot time. 2256 2257 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2258 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2259 compilation or giving cpu0_hotplug kernel parameter at boot. 2260 2261 If unsure, say N. 2262 2263config COMPAT_VDSO 2264 def_bool n 2265 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2266 depends on COMPAT_32 2267 ---help--- 2268 Certain buggy versions of glibc will crash if they are 2269 presented with a 32-bit vDSO that is not mapped at the address 2270 indicated in its segment table. 2271 2272 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2273 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2274 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2275 the only released version with the bug, but OpenSUSE 9 2276 contains a buggy "glibc 2.3.2". 2277 2278 The symptom of the bug is that everything crashes on startup, saying: 2279 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2280 2281 Saying Y here changes the default value of the vdso32 boot 2282 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2283 This works around the glibc bug but hurts performance. 2284 2285 If unsure, say N: if you are compiling your own kernel, you 2286 are unlikely to be using a buggy version of glibc. 2287 2288choice 2289 prompt "vsyscall table for legacy applications" 2290 depends on X86_64 2291 default LEGACY_VSYSCALL_EMULATE 2292 help 2293 Legacy user code that does not know how to find the vDSO expects 2294 to be able to issue three syscalls by calling fixed addresses in 2295 kernel space. Since this location is not randomized with ASLR, 2296 it can be used to assist security vulnerability exploitation. 2297 2298 This setting can be changed at boot time via the kernel command 2299 line parameter vsyscall=[emulate|none]. 2300 2301 On a system with recent enough glibc (2.14 or newer) and no 2302 static binaries, you can say None without a performance penalty 2303 to improve security. 2304 2305 If unsure, select "Emulate". 2306 2307 config LEGACY_VSYSCALL_EMULATE 2308 bool "Emulate" 2309 help 2310 The kernel traps and emulates calls into the fixed 2311 vsyscall address mapping. This makes the mapping 2312 non-executable, but it still contains known contents, 2313 which could be used in certain rare security vulnerability 2314 exploits. This configuration is recommended when userspace 2315 still uses the vsyscall area. 2316 2317 config LEGACY_VSYSCALL_NONE 2318 bool "None" 2319 help 2320 There will be no vsyscall mapping at all. This will 2321 eliminate any risk of ASLR bypass due to the vsyscall 2322 fixed address mapping. Attempts to use the vsyscalls 2323 will be reported to dmesg, so that either old or 2324 malicious userspace programs can be identified. 2325 2326endchoice 2327 2328config CMDLINE_BOOL 2329 bool "Built-in kernel command line" 2330 ---help--- 2331 Allow for specifying boot arguments to the kernel at 2332 build time. On some systems (e.g. embedded ones), it is 2333 necessary or convenient to provide some or all of the 2334 kernel boot arguments with the kernel itself (that is, 2335 to not rely on the boot loader to provide them.) 2336 2337 To compile command line arguments into the kernel, 2338 set this option to 'Y', then fill in the 2339 boot arguments in CONFIG_CMDLINE. 2340 2341 Systems with fully functional boot loaders (i.e. non-embedded) 2342 should leave this option set to 'N'. 2343 2344config CMDLINE 2345 string "Built-in kernel command string" 2346 depends on CMDLINE_BOOL 2347 default "" 2348 ---help--- 2349 Enter arguments here that should be compiled into the kernel 2350 image and used at boot time. If the boot loader provides a 2351 command line at boot time, it is appended to this string to 2352 form the full kernel command line, when the system boots. 2353 2354 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2355 change this behavior. 2356 2357 In most cases, the command line (whether built-in or provided 2358 by the boot loader) should specify the device for the root 2359 file system. 2360 2361config CMDLINE_OVERRIDE 2362 bool "Built-in command line overrides boot loader arguments" 2363 depends on CMDLINE_BOOL 2364 ---help--- 2365 Set this option to 'Y' to have the kernel ignore the boot loader 2366 command line, and use ONLY the built-in command line. 2367 2368 This is used to work around broken boot loaders. This should 2369 be set to 'N' under normal conditions. 2370 2371config MODIFY_LDT_SYSCALL 2372 bool "Enable the LDT (local descriptor table)" if EXPERT 2373 default y 2374 ---help--- 2375 Linux can allow user programs to install a per-process x86 2376 Local Descriptor Table (LDT) using the modify_ldt(2) system 2377 call. This is required to run 16-bit or segmented code such as 2378 DOSEMU or some Wine programs. It is also used by some very old 2379 threading libraries. 2380 2381 Enabling this feature adds a small amount of overhead to 2382 context switches and increases the low-level kernel attack 2383 surface. Disabling it removes the modify_ldt(2) system call. 2384 2385 Saying 'N' here may make sense for embedded or server kernels. 2386 2387source "kernel/livepatch/Kconfig" 2388 2389endmenu 2390 2391config ARCH_HAS_ADD_PAGES 2392 def_bool y 2393 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2394 2395config ARCH_ENABLE_MEMORY_HOTPLUG 2396 def_bool y 2397 depends on X86_64 || (X86_32 && HIGHMEM) 2398 2399config ARCH_ENABLE_MEMORY_HOTREMOVE 2400 def_bool y 2401 depends on MEMORY_HOTPLUG 2402 2403config USE_PERCPU_NUMA_NODE_ID 2404 def_bool y 2405 depends on NUMA 2406 2407config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2408 def_bool y 2409 depends on X86_64 || X86_PAE 2410 2411config ARCH_ENABLE_HUGEPAGE_MIGRATION 2412 def_bool y 2413 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2414 2415config ARCH_ENABLE_THP_MIGRATION 2416 def_bool y 2417 depends on X86_64 && TRANSPARENT_HUGEPAGE 2418 2419menu "Power management and ACPI options" 2420 2421config ARCH_HIBERNATION_HEADER 2422 def_bool y 2423 depends on HIBERNATION 2424 2425source "kernel/power/Kconfig" 2426 2427source "drivers/acpi/Kconfig" 2428 2429source "drivers/sfi/Kconfig" 2430 2431config X86_APM_BOOT 2432 def_bool y 2433 depends on APM 2434 2435menuconfig APM 2436 tristate "APM (Advanced Power Management) BIOS support" 2437 depends on X86_32 && PM_SLEEP 2438 ---help--- 2439 APM is a BIOS specification for saving power using several different 2440 techniques. This is mostly useful for battery powered laptops with 2441 APM compliant BIOSes. If you say Y here, the system time will be 2442 reset after a RESUME operation, the /proc/apm device will provide 2443 battery status information, and user-space programs will receive 2444 notification of APM "events" (e.g. battery status change). 2445 2446 If you select "Y" here, you can disable actual use of the APM 2447 BIOS by passing the "apm=off" option to the kernel at boot time. 2448 2449 Note that the APM support is almost completely disabled for 2450 machines with more than one CPU. 2451 2452 In order to use APM, you will need supporting software. For location 2453 and more information, read <file:Documentation/power/apm-acpi.txt> 2454 and the Battery Powered Linux mini-HOWTO, available from 2455 <http://www.tldp.org/docs.html#howto>. 2456 2457 This driver does not spin down disk drives (see the hdparm(8) 2458 manpage ("man 8 hdparm") for that), and it doesn't turn off 2459 VESA-compliant "green" monitors. 2460 2461 This driver does not support the TI 4000M TravelMate and the ACER 2462 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2463 desktop machines also don't have compliant BIOSes, and this driver 2464 may cause those machines to panic during the boot phase. 2465 2466 Generally, if you don't have a battery in your machine, there isn't 2467 much point in using this driver and you should say N. If you get 2468 random kernel OOPSes or reboots that don't seem to be related to 2469 anything, try disabling/enabling this option (or disabling/enabling 2470 APM in your BIOS). 2471 2472 Some other things you should try when experiencing seemingly random, 2473 "weird" problems: 2474 2475 1) make sure that you have enough swap space and that it is 2476 enabled. 2477 2) pass the "no-hlt" option to the kernel 2478 3) switch on floating point emulation in the kernel and pass 2479 the "no387" option to the kernel 2480 4) pass the "floppy=nodma" option to the kernel 2481 5) pass the "mem=4M" option to the kernel (thereby disabling 2482 all but the first 4 MB of RAM) 2483 6) make sure that the CPU is not over clocked. 2484 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2485 8) disable the cache from your BIOS settings 2486 9) install a fan for the video card or exchange video RAM 2487 10) install a better fan for the CPU 2488 11) exchange RAM chips 2489 12) exchange the motherboard. 2490 2491 To compile this driver as a module, choose M here: the 2492 module will be called apm. 2493 2494if APM 2495 2496config APM_IGNORE_USER_SUSPEND 2497 bool "Ignore USER SUSPEND" 2498 ---help--- 2499 This option will ignore USER SUSPEND requests. On machines with a 2500 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2501 series notebooks, it is necessary to say Y because of a BIOS bug. 2502 2503config APM_DO_ENABLE 2504 bool "Enable PM at boot time" 2505 ---help--- 2506 Enable APM features at boot time. From page 36 of the APM BIOS 2507 specification: "When disabled, the APM BIOS does not automatically 2508 power manage devices, enter the Standby State, enter the Suspend 2509 State, or take power saving steps in response to CPU Idle calls." 2510 This driver will make CPU Idle calls when Linux is idle (unless this 2511 feature is turned off -- see "Do CPU IDLE calls", below). This 2512 should always save battery power, but more complicated APM features 2513 will be dependent on your BIOS implementation. You may need to turn 2514 this option off if your computer hangs at boot time when using APM 2515 support, or if it beeps continuously instead of suspending. Turn 2516 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2517 T400CDT. This is off by default since most machines do fine without 2518 this feature. 2519 2520config APM_CPU_IDLE 2521 depends on CPU_IDLE 2522 bool "Make CPU Idle calls when idle" 2523 ---help--- 2524 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2525 On some machines, this can activate improved power savings, such as 2526 a slowed CPU clock rate, when the machine is idle. These idle calls 2527 are made after the idle loop has run for some length of time (e.g., 2528 333 mS). On some machines, this will cause a hang at boot time or 2529 whenever the CPU becomes idle. (On machines with more than one CPU, 2530 this option does nothing.) 2531 2532config APM_DISPLAY_BLANK 2533 bool "Enable console blanking using APM" 2534 ---help--- 2535 Enable console blanking using the APM. Some laptops can use this to 2536 turn off the LCD backlight when the screen blanker of the Linux 2537 virtual console blanks the screen. Note that this is only used by 2538 the virtual console screen blanker, and won't turn off the backlight 2539 when using the X Window system. This also doesn't have anything to 2540 do with your VESA-compliant power-saving monitor. Further, this 2541 option doesn't work for all laptops -- it might not turn off your 2542 backlight at all, or it might print a lot of errors to the console, 2543 especially if you are using gpm. 2544 2545config APM_ALLOW_INTS 2546 bool "Allow interrupts during APM BIOS calls" 2547 ---help--- 2548 Normally we disable external interrupts while we are making calls to 2549 the APM BIOS as a measure to lessen the effects of a badly behaving 2550 BIOS implementation. The BIOS should reenable interrupts if it 2551 needs to. Unfortunately, some BIOSes do not -- especially those in 2552 many of the newer IBM Thinkpads. If you experience hangs when you 2553 suspend, try setting this to Y. Otherwise, say N. 2554 2555endif # APM 2556 2557source "drivers/cpufreq/Kconfig" 2558 2559source "drivers/cpuidle/Kconfig" 2560 2561source "drivers/idle/Kconfig" 2562 2563endmenu 2564 2565 2566menu "Bus options (PCI etc.)" 2567 2568choice 2569 prompt "PCI access mode" 2570 depends on X86_32 && PCI 2571 default PCI_GOANY 2572 ---help--- 2573 On PCI systems, the BIOS can be used to detect the PCI devices and 2574 determine their configuration. However, some old PCI motherboards 2575 have BIOS bugs and may crash if this is done. Also, some embedded 2576 PCI-based systems don't have any BIOS at all. Linux can also try to 2577 detect the PCI hardware directly without using the BIOS. 2578 2579 With this option, you can specify how Linux should detect the 2580 PCI devices. If you choose "BIOS", the BIOS will be used, 2581 if you choose "Direct", the BIOS won't be used, and if you 2582 choose "MMConfig", then PCI Express MMCONFIG will be used. 2583 If you choose "Any", the kernel will try MMCONFIG, then the 2584 direct access method and falls back to the BIOS if that doesn't 2585 work. If unsure, go with the default, which is "Any". 2586 2587config PCI_GOBIOS 2588 bool "BIOS" 2589 2590config PCI_GOMMCONFIG 2591 bool "MMConfig" 2592 2593config PCI_GODIRECT 2594 bool "Direct" 2595 2596config PCI_GOOLPC 2597 bool "OLPC XO-1" 2598 depends on OLPC 2599 2600config PCI_GOANY 2601 bool "Any" 2602 2603endchoice 2604 2605config PCI_BIOS 2606 def_bool y 2607 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2608 2609# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2610config PCI_DIRECT 2611 def_bool y 2612 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2613 2614config PCI_MMCONFIG 2615 bool "Support mmconfig PCI config space access" if X86_64 2616 default y 2617 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2618 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2619 2620config PCI_OLPC 2621 def_bool y 2622 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2623 2624config PCI_XEN 2625 def_bool y 2626 depends on PCI && XEN 2627 select SWIOTLB_XEN 2628 2629config MMCONF_FAM10H 2630 def_bool y 2631 depends on X86_64 && PCI_MMCONFIG && ACPI 2632 2633config PCI_CNB20LE_QUIRK 2634 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2635 depends on PCI 2636 help 2637 Read the PCI windows out of the CNB20LE host bridge. This allows 2638 PCI hotplug to work on systems with the CNB20LE chipset which do 2639 not have ACPI. 2640 2641 There's no public spec for this chipset, and this functionality 2642 is known to be incomplete. 2643 2644 You should say N unless you know you need this. 2645 2646config ISA_BUS 2647 bool "ISA bus support on modern systems" if EXPERT 2648 help 2649 Expose ISA bus device drivers and options available for selection and 2650 configuration. Enable this option if your target machine has an ISA 2651 bus. ISA is an older system, displaced by PCI and newer bus 2652 architectures -- if your target machine is modern, it probably does 2653 not have an ISA bus. 2654 2655 If unsure, say N. 2656 2657# x86_64 have no ISA slots, but can have ISA-style DMA. 2658config ISA_DMA_API 2659 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2660 default y 2661 help 2662 Enables ISA-style DMA support for devices requiring such controllers. 2663 If unsure, say Y. 2664 2665if X86_32 2666 2667config ISA 2668 bool "ISA support" 2669 ---help--- 2670 Find out whether you have ISA slots on your motherboard. ISA is the 2671 name of a bus system, i.e. the way the CPU talks to the other stuff 2672 inside your box. Other bus systems are PCI, EISA, MicroChannel 2673 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2674 newer boards don't support it. If you have ISA, say Y, otherwise N. 2675 2676config SCx200 2677 tristate "NatSemi SCx200 support" 2678 ---help--- 2679 This provides basic support for National Semiconductor's 2680 (now AMD's) Geode processors. The driver probes for the 2681 PCI-IDs of several on-chip devices, so its a good dependency 2682 for other scx200_* drivers. 2683 2684 If compiled as a module, the driver is named scx200. 2685 2686config SCx200HR_TIMER 2687 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2688 depends on SCx200 2689 default y 2690 ---help--- 2691 This driver provides a clocksource built upon the on-chip 2692 27MHz high-resolution timer. Its also a workaround for 2693 NSC Geode SC-1100's buggy TSC, which loses time when the 2694 processor goes idle (as is done by the scheduler). The 2695 other workaround is idle=poll boot option. 2696 2697config OLPC 2698 bool "One Laptop Per Child support" 2699 depends on !X86_PAE 2700 select GPIOLIB 2701 select OF 2702 select OF_PROMTREE 2703 select IRQ_DOMAIN 2704 ---help--- 2705 Add support for detecting the unique features of the OLPC 2706 XO hardware. 2707 2708config OLPC_XO1_PM 2709 bool "OLPC XO-1 Power Management" 2710 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2711 ---help--- 2712 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2713 2714config OLPC_XO1_RTC 2715 bool "OLPC XO-1 Real Time Clock" 2716 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2717 ---help--- 2718 Add support for the XO-1 real time clock, which can be used as a 2719 programmable wakeup source. 2720 2721config OLPC_XO1_SCI 2722 bool "OLPC XO-1 SCI extras" 2723 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2724 depends on INPUT=y 2725 select POWER_SUPPLY 2726 ---help--- 2727 Add support for SCI-based features of the OLPC XO-1 laptop: 2728 - EC-driven system wakeups 2729 - Power button 2730 - Ebook switch 2731 - Lid switch 2732 - AC adapter status updates 2733 - Battery status updates 2734 2735config OLPC_XO15_SCI 2736 bool "OLPC XO-1.5 SCI extras" 2737 depends on OLPC && ACPI 2738 select POWER_SUPPLY 2739 ---help--- 2740 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2741 - EC-driven system wakeups 2742 - AC adapter status updates 2743 - Battery status updates 2744 2745config ALIX 2746 bool "PCEngines ALIX System Support (LED setup)" 2747 select GPIOLIB 2748 ---help--- 2749 This option enables system support for the PCEngines ALIX. 2750 At present this just sets up LEDs for GPIO control on 2751 ALIX2/3/6 boards. However, other system specific setup should 2752 get added here. 2753 2754 Note: You must still enable the drivers for GPIO and LED support 2755 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2756 2757 Note: You have to set alix.force=1 for boards with Award BIOS. 2758 2759config NET5501 2760 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2761 select GPIOLIB 2762 ---help--- 2763 This option enables system support for the Soekris Engineering net5501. 2764 2765config GEOS 2766 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2767 select GPIOLIB 2768 depends on DMI 2769 ---help--- 2770 This option enables system support for the Traverse Technologies GEOS. 2771 2772config TS5500 2773 bool "Technologic Systems TS-5500 platform support" 2774 depends on MELAN 2775 select CHECK_SIGNATURE 2776 select NEW_LEDS 2777 select LEDS_CLASS 2778 ---help--- 2779 This option enables system support for the Technologic Systems TS-5500. 2780 2781endif # X86_32 2782 2783config AMD_NB 2784 def_bool y 2785 depends on CPU_SUP_AMD && PCI 2786 2787config X86_SYSFB 2788 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2789 help 2790 Firmwares often provide initial graphics framebuffers so the BIOS, 2791 bootloader or kernel can show basic video-output during boot for 2792 user-guidance and debugging. Historically, x86 used the VESA BIOS 2793 Extensions and EFI-framebuffers for this, which are mostly limited 2794 to x86. 2795 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2796 framebuffers so the new generic system-framebuffer drivers can be 2797 used on x86. If the framebuffer is not compatible with the generic 2798 modes, it is advertised as fallback platform framebuffer so legacy 2799 drivers like efifb, vesafb and uvesafb can pick it up. 2800 If this option is not selected, all system framebuffers are always 2801 marked as fallback platform framebuffers as usual. 2802 2803 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2804 not be able to pick up generic system framebuffers if this option 2805 is selected. You are highly encouraged to enable simplefb as 2806 replacement if you select this option. simplefb can correctly deal 2807 with generic system framebuffers. But you should still keep vesafb 2808 and others enabled as fallback if a system framebuffer is 2809 incompatible with simplefb. 2810 2811 If unsure, say Y. 2812 2813endmenu 2814 2815 2816menu "Binary Emulations" 2817 2818config IA32_EMULATION 2819 bool "IA32 Emulation" 2820 depends on X86_64 2821 select ARCH_WANT_OLD_COMPAT_IPC 2822 select BINFMT_ELF 2823 select COMPAT_BINFMT_ELF 2824 select COMPAT_OLD_SIGACTION 2825 ---help--- 2826 Include code to run legacy 32-bit programs under a 2827 64-bit kernel. You should likely turn this on, unless you're 2828 100% sure that you don't have any 32-bit programs left. 2829 2830config IA32_AOUT 2831 tristate "IA32 a.out support" 2832 depends on IA32_EMULATION 2833 depends on BROKEN 2834 ---help--- 2835 Support old a.out binaries in the 32bit emulation. 2836 2837config X86_X32 2838 bool "x32 ABI for 64-bit mode" 2839 depends on X86_64 2840 ---help--- 2841 Include code to run binaries for the x32 native 32-bit ABI 2842 for 64-bit processors. An x32 process gets access to the 2843 full 64-bit register file and wide data path while leaving 2844 pointers at 32 bits for smaller memory footprint. 2845 2846 You will need a recent binutils (2.22 or later) with 2847 elf32_x86_64 support enabled to compile a kernel with this 2848 option set. 2849 2850config COMPAT_32 2851 def_bool y 2852 depends on IA32_EMULATION || X86_32 2853 select HAVE_UID16 2854 select OLD_SIGSUSPEND3 2855 2856config COMPAT 2857 def_bool y 2858 depends on IA32_EMULATION || X86_X32 2859 2860if COMPAT 2861config COMPAT_FOR_U64_ALIGNMENT 2862 def_bool y 2863 2864config SYSVIPC_COMPAT 2865 def_bool y 2866 depends on SYSVIPC 2867endif 2868 2869endmenu 2870 2871 2872config HAVE_ATOMIC_IOMAP 2873 def_bool y 2874 depends on X86_32 2875 2876config X86_DEV_DMA_OPS 2877 bool 2878 2879config HAVE_GENERIC_GUP 2880 def_bool y 2881 2882source "drivers/firmware/Kconfig" 2883 2884source "arch/x86/kvm/Kconfig" 2885