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 if CC_HAS_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_MEM_ENCRYPT 72 select ARCH_HAS_MEMBARRIER_SYNC_CORE 73 select ARCH_HAS_PMEM_API if X86_64 74 select ARCH_HAS_PTE_DEVMAP if X86_64 75 select ARCH_HAS_PTE_SPECIAL 76 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 77 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 78 select ARCH_HAS_SET_MEMORY 79 select ARCH_HAS_SET_DIRECT_MAP 80 select ARCH_HAS_STRICT_KERNEL_RWX 81 select ARCH_HAS_STRICT_MODULE_RWX 82 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 83 select ARCH_HAS_UBSAN_SANITIZE_ALL 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_WANT_DEFAULT_BPF_JIT if X86_64 97 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 98 select ARCH_WANT_HUGE_PMD_SHARE 99 select ARCH_WANTS_THP_SWAP if X86_64 100 select BUILDTIME_EXTABLE_SORT 101 select CLKEVT_I8253 102 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 103 select CLOCKSOURCE_WATCHDOG 104 select DCACHE_WORD_ACCESS 105 select EDAC_ATOMIC_SCRUB 106 select EDAC_SUPPORT 107 select GENERIC_CLOCKEVENTS 108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 109 select GENERIC_CLOCKEVENTS_MIN_ADJUST 110 select GENERIC_CMOS_UPDATE 111 select GENERIC_CPU_AUTOPROBE 112 select GENERIC_CPU_VULNERABILITIES 113 select GENERIC_EARLY_IOREMAP 114 select GENERIC_FIND_FIRST_BIT 115 select GENERIC_IOMAP 116 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 117 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 118 select GENERIC_IRQ_MIGRATION if SMP 119 select GENERIC_IRQ_PROBE 120 select GENERIC_IRQ_RESERVATION_MODE 121 select GENERIC_IRQ_SHOW 122 select GENERIC_PENDING_IRQ if SMP 123 select GENERIC_SMP_IDLE_THREAD 124 select GENERIC_STRNCPY_FROM_USER 125 select GENERIC_STRNLEN_USER 126 select GENERIC_TIME_VSYSCALL 127 select GENERIC_GETTIMEOFDAY 128 select GUP_GET_PTE_LOW_HIGH if X86_PAE 129 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 130 select HAVE_ACPI_APEI if ACPI 131 select HAVE_ACPI_APEI_NMI if ACPI 132 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 133 select HAVE_ARCH_AUDITSYSCALL 134 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 135 select HAVE_ARCH_JUMP_LABEL 136 select HAVE_ARCH_JUMP_LABEL_RELATIVE 137 select HAVE_ARCH_KASAN if X86_64 138 select HAVE_ARCH_KASAN_VMALLOC if X86_64 139 select HAVE_ARCH_KGDB 140 select HAVE_ARCH_MMAP_RND_BITS if MMU 141 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 142 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 143 select HAVE_ARCH_PREL32_RELOCATIONS 144 select HAVE_ARCH_SECCOMP_FILTER 145 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 146 select HAVE_ARCH_STACKLEAK 147 select HAVE_ARCH_TRACEHOOK 148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 149 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 150 select HAVE_ARCH_VMAP_STACK if X86_64 151 select HAVE_ARCH_WITHIN_STACK_FRAMES 152 select HAVE_ASM_MODVERSIONS 153 select HAVE_CMPXCHG_DOUBLE 154 select HAVE_CMPXCHG_LOCAL 155 select HAVE_CONTEXT_TRACKING if X86_64 156 select HAVE_COPY_THREAD_TLS 157 select HAVE_C_RECORDMCOUNT 158 select HAVE_DEBUG_KMEMLEAK 159 select HAVE_DMA_CONTIGUOUS 160 select HAVE_DYNAMIC_FTRACE 161 select HAVE_DYNAMIC_FTRACE_WITH_REGS 162 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 163 select HAVE_EBPF_JIT 164 select HAVE_EFFICIENT_UNALIGNED_ACCESS 165 select HAVE_EISA 166 select HAVE_EXIT_THREAD 167 select HAVE_FAST_GUP 168 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 169 select HAVE_FTRACE_MCOUNT_RECORD 170 select HAVE_FUNCTION_GRAPH_TRACER 171 select HAVE_FUNCTION_TRACER 172 select HAVE_GCC_PLUGINS 173 select HAVE_HW_BREAKPOINT 174 select HAVE_IDE 175 select HAVE_IOREMAP_PROT 176 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 177 select HAVE_IRQ_TIME_ACCOUNTING 178 select HAVE_KERNEL_BZIP2 179 select HAVE_KERNEL_GZIP 180 select HAVE_KERNEL_LZ4 181 select HAVE_KERNEL_LZMA 182 select HAVE_KERNEL_LZO 183 select HAVE_KERNEL_XZ 184 select HAVE_KPROBES 185 select HAVE_KPROBES_ON_FTRACE 186 select HAVE_FUNCTION_ERROR_INJECTION 187 select HAVE_KRETPROBES 188 select HAVE_KVM 189 select HAVE_LIVEPATCH if X86_64 190 select HAVE_MEMBLOCK_NODE_MAP 191 select HAVE_MIXED_BREAKPOINTS_REGS 192 select HAVE_MOD_ARCH_SPECIFIC 193 select HAVE_MOVE_PMD 194 select HAVE_NMI 195 select HAVE_OPROFILE 196 select HAVE_OPTPROBES 197 select HAVE_PCSPKR_PLATFORM 198 select HAVE_PERF_EVENTS 199 select HAVE_PERF_EVENTS_NMI 200 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 201 select HAVE_PCI 202 select HAVE_PERF_REGS 203 select HAVE_PERF_USER_STACK_DUMP 204 select HAVE_RCU_TABLE_FREE if PARAVIRT 205 select HAVE_REGS_AND_STACK_ACCESS_API 206 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 207 select HAVE_FUNCTION_ARG_ACCESS_API 208 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 209 select HAVE_STACK_VALIDATION if X86_64 210 select HAVE_RSEQ 211 select HAVE_SYSCALL_TRACEPOINTS 212 select HAVE_UNSTABLE_SCHED_CLOCK 213 select HAVE_USER_RETURN_NOTIFIER 214 select HAVE_GENERIC_VDSO 215 select HOTPLUG_SMT if SMP 216 select IRQ_FORCED_THREADING 217 select NEED_SG_DMA_LENGTH 218 select PCI_DOMAINS if PCI 219 select PCI_LOCKLESS_CONFIG if PCI 220 select PERF_EVENTS 221 select RTC_LIB 222 select RTC_MC146818_LIB 223 select SPARSE_IRQ 224 select SRCU 225 select SYSCTL_EXCEPTION_TRACE 226 select THREAD_INFO_IN_TASK 227 select USER_STACKTRACE_SUPPORT 228 select VIRT_TO_BUS 229 select X86_FEATURE_NAMES if PROC_FS 230 select PROC_PID_ARCH_STATUS if PROC_FS 231 232config INSTRUCTION_DECODER 233 def_bool y 234 depends on KPROBES || PERF_EVENTS || UPROBES 235 236config OUTPUT_FORMAT 237 string 238 default "elf32-i386" if X86_32 239 default "elf64-x86-64" if X86_64 240 241config ARCH_DEFCONFIG 242 string 243 default "arch/x86/configs/i386_defconfig" if X86_32 244 default "arch/x86/configs/x86_64_defconfig" if X86_64 245 246config LOCKDEP_SUPPORT 247 def_bool y 248 249config STACKTRACE_SUPPORT 250 def_bool y 251 252config MMU 253 def_bool y 254 255config ARCH_MMAP_RND_BITS_MIN 256 default 28 if 64BIT 257 default 8 258 259config ARCH_MMAP_RND_BITS_MAX 260 default 32 if 64BIT 261 default 16 262 263config ARCH_MMAP_RND_COMPAT_BITS_MIN 264 default 8 265 266config ARCH_MMAP_RND_COMPAT_BITS_MAX 267 default 16 268 269config SBUS 270 bool 271 272config GENERIC_ISA_DMA 273 def_bool y 274 depends on ISA_DMA_API 275 276config GENERIC_BUG 277 def_bool y 278 depends on BUG 279 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 280 281config GENERIC_BUG_RELATIVE_POINTERS 282 bool 283 284config ARCH_MAY_HAVE_PC_FDC 285 def_bool y 286 depends on ISA_DMA_API 287 288config GENERIC_CALIBRATE_DELAY 289 def_bool y 290 291config ARCH_HAS_CPU_RELAX 292 def_bool y 293 294config ARCH_HAS_CACHE_LINE_SIZE 295 def_bool y 296 297config ARCH_HAS_FILTER_PGPROT 298 def_bool y 299 300config HAVE_SETUP_PER_CPU_AREA 301 def_bool y 302 303config NEED_PER_CPU_EMBED_FIRST_CHUNK 304 def_bool y 305 306config NEED_PER_CPU_PAGE_FIRST_CHUNK 307 def_bool y 308 309config ARCH_HIBERNATION_POSSIBLE 310 def_bool y 311 312config ARCH_SUSPEND_POSSIBLE 313 def_bool y 314 315config ARCH_WANT_GENERAL_HUGETLB 316 def_bool y 317 318config ZONE_DMA32 319 def_bool y if X86_64 320 321config AUDIT_ARCH 322 def_bool y if X86_64 323 324config ARCH_SUPPORTS_DEBUG_PAGEALLOC 325 def_bool y 326 327config KASAN_SHADOW_OFFSET 328 hex 329 depends on KASAN 330 default 0xdffffc0000000000 331 332config HAVE_INTEL_TXT 333 def_bool y 334 depends on INTEL_IOMMU && ACPI 335 336config X86_32_SMP 337 def_bool y 338 depends on X86_32 && SMP 339 340config X86_64_SMP 341 def_bool y 342 depends on X86_64 && SMP 343 344config X86_32_LAZY_GS 345 def_bool y 346 depends on X86_32 && !STACKPROTECTOR 347 348config ARCH_SUPPORTS_UPROBES 349 def_bool y 350 351config FIX_EARLYCON_MEM 352 def_bool y 353 354config DYNAMIC_PHYSICAL_MASK 355 bool 356 357config PGTABLE_LEVELS 358 int 359 default 5 if X86_5LEVEL 360 default 4 if X86_64 361 default 3 if X86_PAE 362 default 2 363 364config CC_HAS_SANE_STACKPROTECTOR 365 bool 366 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 367 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 368 help 369 We have to make sure stack protector is unconditionally disabled if 370 the compiler produces broken code. 371 372menu "Processor type and features" 373 374config ZONE_DMA 375 bool "DMA memory allocation support" if EXPERT 376 default y 377 help 378 DMA memory allocation support allows devices with less than 32-bit 379 addressing to allocate within the first 16MB of address space. 380 Disable if no such devices will be used. 381 382 If unsure, say Y. 383 384config SMP 385 bool "Symmetric multi-processing support" 386 ---help--- 387 This enables support for systems with more than one CPU. If you have 388 a system with only one CPU, say N. If you have a system with more 389 than one CPU, say Y. 390 391 If you say N here, the kernel will run on uni- and multiprocessor 392 machines, but will use only one CPU of a multiprocessor machine. If 393 you say Y here, the kernel will run on many, but not all, 394 uniprocessor machines. On a uniprocessor machine, the kernel 395 will run faster if you say N here. 396 397 Note that if you say Y here and choose architecture "586" or 398 "Pentium" under "Processor family", the kernel will not work on 486 399 architectures. Similarly, multiprocessor kernels for the "PPro" 400 architecture may not work on all Pentium based boards. 401 402 People using multiprocessor machines who say Y here should also say 403 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 404 Management" code will be disabled if you say Y here. 405 406 See also <file:Documentation/x86/i386/IO-APIC.rst>, 407 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 408 <http://www.tldp.org/docs.html#howto>. 409 410 If you don't know what to do here, say N. 411 412config X86_FEATURE_NAMES 413 bool "Processor feature human-readable names" if EMBEDDED 414 default y 415 ---help--- 416 This option compiles in a table of x86 feature bits and corresponding 417 names. This is required to support /proc/cpuinfo and a few kernel 418 messages. You can disable this to save space, at the expense of 419 making those few kernel messages show numeric feature bits instead. 420 421 If in doubt, say Y. 422 423config X86_X2APIC 424 bool "Support x2apic" 425 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 426 ---help--- 427 This enables x2apic support on CPUs that have this feature. 428 429 This allows 32-bit apic IDs (so it can support very large systems), 430 and accesses the local apic via MSRs not via mmio. 431 432 If you don't know what to do here, say N. 433 434config X86_MPPARSE 435 bool "Enable MPS table" if ACPI || SFI 436 default y 437 depends on X86_LOCAL_APIC 438 ---help--- 439 For old smp systems that do not have proper acpi support. Newer systems 440 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 441 442config GOLDFISH 443 def_bool y 444 depends on X86_GOLDFISH 445 446config RETPOLINE 447 bool "Avoid speculative indirect branches in kernel" 448 default y 449 select STACK_VALIDATION if HAVE_STACK_VALIDATION 450 help 451 Compile kernel with the retpoline compiler options to guard against 452 kernel-to-user data leaks by avoiding speculative indirect 453 branches. Requires a compiler with -mindirect-branch=thunk-extern 454 support for full protection. The kernel may run slower. 455 456config X86_CPU_RESCTRL 457 bool "x86 CPU resource control support" 458 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 459 select KERNFS 460 help 461 Enable x86 CPU resource control support. 462 463 Provide support for the allocation and monitoring of system resources 464 usage by the CPU. 465 466 Intel calls this Intel Resource Director Technology 467 (Intel(R) RDT). More information about RDT can be found in the 468 Intel x86 Architecture Software Developer Manual. 469 470 AMD calls this AMD Platform Quality of Service (AMD QoS). 471 More information about AMD QoS can be found in the AMD64 Technology 472 Platform Quality of Service Extensions manual. 473 474 Say N if unsure. 475 476if X86_32 477config X86_BIGSMP 478 bool "Support for big SMP systems with more than 8 CPUs" 479 depends on SMP 480 ---help--- 481 This option is needed for the systems that have more than 8 CPUs 482 483config X86_EXTENDED_PLATFORM 484 bool "Support for extended (non-PC) x86 platforms" 485 default y 486 ---help--- 487 If you disable this option then the kernel will only support 488 standard PC platforms. (which covers the vast majority of 489 systems out there.) 490 491 If you enable this option then you'll be able to select support 492 for the following (non-PC) 32 bit x86 platforms: 493 Goldfish (Android emulator) 494 AMD Elan 495 RDC R-321x SoC 496 SGI 320/540 (Visual Workstation) 497 STA2X11-based (e.g. Northville) 498 Moorestown MID devices 499 500 If you have one of these systems, or if you want to build a 501 generic distribution kernel, say Y here - otherwise say N. 502endif 503 504if X86_64 505config X86_EXTENDED_PLATFORM 506 bool "Support for extended (non-PC) x86 platforms" 507 default y 508 ---help--- 509 If you disable this option then the kernel will only support 510 standard PC platforms. (which covers the vast majority of 511 systems out there.) 512 513 If you enable this option then you'll be able to select support 514 for the following (non-PC) 64 bit x86 platforms: 515 Numascale NumaChip 516 ScaleMP vSMP 517 SGI Ultraviolet 518 519 If you have one of these systems, or if you want to build a 520 generic distribution kernel, say Y here - otherwise say N. 521endif 522# This is an alphabetically sorted list of 64 bit extended platforms 523# Please maintain the alphabetic order if and when there are additions 524config X86_NUMACHIP 525 bool "Numascale NumaChip" 526 depends on X86_64 527 depends on X86_EXTENDED_PLATFORM 528 depends on NUMA 529 depends on SMP 530 depends on X86_X2APIC 531 depends on PCI_MMCONFIG 532 ---help--- 533 Adds support for Numascale NumaChip large-SMP systems. Needed to 534 enable more than ~168 cores. 535 If you don't have one of these, you should say N here. 536 537config X86_VSMP 538 bool "ScaleMP vSMP" 539 select HYPERVISOR_GUEST 540 select PARAVIRT 541 depends on X86_64 && PCI 542 depends on X86_EXTENDED_PLATFORM 543 depends on SMP 544 ---help--- 545 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 546 supposed to run on these EM64T-based machines. Only choose this option 547 if you have one of these machines. 548 549config X86_UV 550 bool "SGI Ultraviolet" 551 depends on X86_64 552 depends on X86_EXTENDED_PLATFORM 553 depends on NUMA 554 depends on EFI 555 depends on X86_X2APIC 556 depends on PCI 557 ---help--- 558 This option is needed in order to support SGI Ultraviolet systems. 559 If you don't have one of these, you should say N here. 560 561# Following is an alphabetically sorted list of 32 bit extended platforms 562# Please maintain the alphabetic order if and when there are additions 563 564config X86_GOLDFISH 565 bool "Goldfish (Virtual Platform)" 566 depends on X86_EXTENDED_PLATFORM 567 ---help--- 568 Enable support for the Goldfish virtual platform used primarily 569 for Android development. Unless you are building for the Android 570 Goldfish emulator say N here. 571 572config X86_INTEL_CE 573 bool "CE4100 TV platform" 574 depends on PCI 575 depends on PCI_GODIRECT 576 depends on X86_IO_APIC 577 depends on X86_32 578 depends on X86_EXTENDED_PLATFORM 579 select X86_REBOOTFIXUPS 580 select OF 581 select OF_EARLY_FLATTREE 582 ---help--- 583 Select for the Intel CE media processor (CE4100) SOC. 584 This option compiles in support for the CE4100 SOC for settop 585 boxes and media devices. 586 587config X86_INTEL_MID 588 bool "Intel MID platform support" 589 depends on X86_EXTENDED_PLATFORM 590 depends on X86_PLATFORM_DEVICES 591 depends on PCI 592 depends on X86_64 || (PCI_GOANY && X86_32) 593 depends on X86_IO_APIC 594 select SFI 595 select I2C 596 select DW_APB_TIMER 597 select APB_TIMER 598 select INTEL_SCU_IPC 599 select MFD_INTEL_MSIC 600 ---help--- 601 Select to build a kernel capable of supporting Intel MID (Mobile 602 Internet Device) platform systems which do not have the PCI legacy 603 interfaces. If you are building for a PC class system say N here. 604 605 Intel MID platforms are based on an Intel processor and chipset which 606 consume less power than most of the x86 derivatives. 607 608config X86_INTEL_QUARK 609 bool "Intel Quark platform support" 610 depends on X86_32 611 depends on X86_EXTENDED_PLATFORM 612 depends on X86_PLATFORM_DEVICES 613 depends on X86_TSC 614 depends on PCI 615 depends on PCI_GOANY 616 depends on X86_IO_APIC 617 select IOSF_MBI 618 select INTEL_IMR 619 select COMMON_CLK 620 ---help--- 621 Select to include support for Quark X1000 SoC. 622 Say Y here if you have a Quark based system such as the Arduino 623 compatible Intel Galileo. 624 625config X86_INTEL_LPSS 626 bool "Intel Low Power Subsystem Support" 627 depends on X86 && ACPI && PCI 628 select COMMON_CLK 629 select PINCTRL 630 select IOSF_MBI 631 ---help--- 632 Select to build support for Intel Low Power Subsystem such as 633 found on Intel Lynxpoint PCH. Selecting this option enables 634 things like clock tree (common clock framework) and pincontrol 635 which are needed by the LPSS peripheral drivers. 636 637config X86_AMD_PLATFORM_DEVICE 638 bool "AMD ACPI2Platform devices support" 639 depends on ACPI 640 select COMMON_CLK 641 select PINCTRL 642 ---help--- 643 Select to interpret AMD specific ACPI device to platform device 644 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 645 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 646 implemented under PINCTRL subsystem. 647 648config IOSF_MBI 649 tristate "Intel SoC IOSF Sideband support for SoC platforms" 650 depends on PCI 651 ---help--- 652 This option enables sideband register access support for Intel SoC 653 platforms. On these platforms the IOSF sideband is used in lieu of 654 MSR's for some register accesses, mostly but not limited to thermal 655 and power. Drivers may query the availability of this device to 656 determine if they need the sideband in order to work on these 657 platforms. The sideband is available on the following SoC products. 658 This list is not meant to be exclusive. 659 - BayTrail 660 - Braswell 661 - Quark 662 663 You should say Y if you are running a kernel on one of these SoC's. 664 665config IOSF_MBI_DEBUG 666 bool "Enable IOSF sideband access through debugfs" 667 depends on IOSF_MBI && DEBUG_FS 668 ---help--- 669 Select this option to expose the IOSF sideband access registers (MCR, 670 MDR, MCRX) through debugfs to write and read register information from 671 different units on the SoC. This is most useful for obtaining device 672 state information for debug and analysis. As this is a general access 673 mechanism, users of this option would have specific knowledge of the 674 device they want to access. 675 676 If you don't require the option or are in doubt, say N. 677 678config X86_RDC321X 679 bool "RDC R-321x SoC" 680 depends on X86_32 681 depends on X86_EXTENDED_PLATFORM 682 select M486 683 select X86_REBOOTFIXUPS 684 ---help--- 685 This option is needed for RDC R-321x system-on-chip, also known 686 as R-8610-(G). 687 If you don't have one of these chips, you should say N here. 688 689config X86_32_NON_STANDARD 690 bool "Support non-standard 32-bit SMP architectures" 691 depends on X86_32 && SMP 692 depends on X86_EXTENDED_PLATFORM 693 ---help--- 694 This option compiles in the bigsmp and STA2X11 default 695 subarchitectures. It is intended for a generic binary 696 kernel. If you select them all, kernel will probe it one by 697 one and will fallback to default. 698 699# Alphabetically sorted list of Non standard 32 bit platforms 700 701config X86_SUPPORTS_MEMORY_FAILURE 702 def_bool y 703 # MCE code calls memory_failure(): 704 depends on X86_MCE 705 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 706 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 707 depends on X86_64 || !SPARSEMEM 708 select ARCH_SUPPORTS_MEMORY_FAILURE 709 710config STA2X11 711 bool "STA2X11 Companion Chip Support" 712 depends on X86_32_NON_STANDARD && PCI 713 select SWIOTLB 714 select MFD_STA2X11 715 select GPIOLIB 716 ---help--- 717 This adds support for boards based on the STA2X11 IO-Hub, 718 a.k.a. "ConneXt". The chip is used in place of the standard 719 PC chipset, so all "standard" peripherals are missing. If this 720 option is selected the kernel will still be able to boot on 721 standard PC machines. 722 723config X86_32_IRIS 724 tristate "Eurobraille/Iris poweroff module" 725 depends on X86_32 726 ---help--- 727 The Iris machines from EuroBraille do not have APM or ACPI support 728 to shut themselves down properly. A special I/O sequence is 729 needed to do so, which is what this module does at 730 kernel shutdown. 731 732 This is only for Iris machines from EuroBraille. 733 734 If unused, say N. 735 736config SCHED_OMIT_FRAME_POINTER 737 def_bool y 738 prompt "Single-depth WCHAN output" 739 depends on X86 740 ---help--- 741 Calculate simpler /proc/<PID>/wchan values. If this option 742 is disabled then wchan values will recurse back to the 743 caller function. This provides more accurate wchan values, 744 at the expense of slightly more scheduling overhead. 745 746 If in doubt, say "Y". 747 748menuconfig HYPERVISOR_GUEST 749 bool "Linux guest support" 750 ---help--- 751 Say Y here to enable options for running Linux under various hyper- 752 visors. This option enables basic hypervisor detection and platform 753 setup. 754 755 If you say N, all options in this submenu will be skipped and 756 disabled, and Linux guest support won't be built in. 757 758if HYPERVISOR_GUEST 759 760config PARAVIRT 761 bool "Enable paravirtualization code" 762 ---help--- 763 This changes the kernel so it can modify itself when it is run 764 under a hypervisor, potentially improving performance significantly 765 over full virtualization. However, when run without a hypervisor 766 the kernel is theoretically slower and slightly larger. 767 768config PARAVIRT_XXL 769 bool 770 771config PARAVIRT_DEBUG 772 bool "paravirt-ops debugging" 773 depends on PARAVIRT && DEBUG_KERNEL 774 ---help--- 775 Enable to debug paravirt_ops internals. Specifically, BUG if 776 a paravirt_op is missing when it is called. 777 778config PARAVIRT_SPINLOCKS 779 bool "Paravirtualization layer for spinlocks" 780 depends on PARAVIRT && SMP 781 ---help--- 782 Paravirtualized spinlocks allow a pvops backend to replace the 783 spinlock implementation with something virtualization-friendly 784 (for example, block the virtual CPU rather than spinning). 785 786 It has a minimal impact on native kernels and gives a nice performance 787 benefit on paravirtualized KVM / Xen kernels. 788 789 If you are unsure how to answer this question, answer Y. 790 791config X86_HV_CALLBACK_VECTOR 792 def_bool n 793 794source "arch/x86/xen/Kconfig" 795 796config KVM_GUEST 797 bool "KVM Guest support (including kvmclock)" 798 depends on PARAVIRT 799 select PARAVIRT_CLOCK 800 select ARCH_CPUIDLE_HALTPOLL 801 default y 802 ---help--- 803 This option enables various optimizations for running under the KVM 804 hypervisor. It includes a paravirtualized clock, so that instead 805 of relying on a PIT (or probably other) emulation by the 806 underlying device model, the host provides the guest with 807 timing infrastructure such as time of day, and system time 808 809config ARCH_CPUIDLE_HALTPOLL 810 def_bool n 811 prompt "Disable host haltpoll when loading haltpoll driver" 812 help 813 If virtualized under KVM, disable host haltpoll. 814 815config PVH 816 bool "Support for running PVH guests" 817 ---help--- 818 This option enables the PVH entry point for guest virtual machines 819 as specified in the x86/HVM direct boot ABI. 820 821config KVM_DEBUG_FS 822 bool "Enable debug information for KVM Guests in debugfs" 823 depends on KVM_GUEST && DEBUG_FS 824 ---help--- 825 This option enables collection of various statistics for KVM guest. 826 Statistics are displayed in debugfs filesystem. Enabling this option 827 may incur significant overhead. 828 829config PARAVIRT_TIME_ACCOUNTING 830 bool "Paravirtual steal time accounting" 831 depends on PARAVIRT 832 ---help--- 833 Select this option to enable fine granularity task steal time 834 accounting. Time spent executing other tasks in parallel with 835 the current vCPU is discounted from the vCPU power. To account for 836 that, there can be a small performance impact. 837 838 If in doubt, say N here. 839 840config PARAVIRT_CLOCK 841 bool 842 843config JAILHOUSE_GUEST 844 bool "Jailhouse non-root cell support" 845 depends on X86_64 && PCI 846 select X86_PM_TIMER 847 ---help--- 848 This option allows to run Linux as guest in a Jailhouse non-root 849 cell. You can leave this option disabled if you only want to start 850 Jailhouse and run Linux afterwards in the root cell. 851 852config ACRN_GUEST 853 bool "ACRN Guest support" 854 depends on X86_64 855 select X86_HV_CALLBACK_VECTOR 856 help 857 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 858 a flexible, lightweight reference open-source hypervisor, built with 859 real-time and safety-criticality in mind. It is built for embedded 860 IOT with small footprint and real-time features. More details can be 861 found in https://projectacrn.org/. 862 863endif #HYPERVISOR_GUEST 864 865source "arch/x86/Kconfig.cpu" 866 867config HPET_TIMER 868 def_bool X86_64 869 prompt "HPET Timer Support" if X86_32 870 ---help--- 871 Use the IA-PC HPET (High Precision Event Timer) to manage 872 time in preference to the PIT and RTC, if a HPET is 873 present. 874 HPET is the next generation timer replacing legacy 8254s. 875 The HPET provides a stable time base on SMP 876 systems, unlike the TSC, but it is more expensive to access, 877 as it is off-chip. The interface used is documented 878 in the HPET spec, revision 1. 879 880 You can safely choose Y here. However, HPET will only be 881 activated if the platform and the BIOS support this feature. 882 Otherwise the 8254 will be used for timing services. 883 884 Choose N to continue using the legacy 8254 timer. 885 886config HPET_EMULATE_RTC 887 def_bool y 888 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 889 890config APB_TIMER 891 def_bool y if X86_INTEL_MID 892 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 893 select DW_APB_TIMER 894 depends on X86_INTEL_MID && SFI 895 help 896 APB timer is the replacement for 8254, HPET on X86 MID platforms. 897 The APBT provides a stable time base on SMP 898 systems, unlike the TSC, but it is more expensive to access, 899 as it is off-chip. APB timers are always running regardless of CPU 900 C states, they are used as per CPU clockevent device when possible. 901 902# Mark as expert because too many people got it wrong. 903# The code disables itself when not needed. 904config DMI 905 default y 906 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 907 bool "Enable DMI scanning" if EXPERT 908 ---help--- 909 Enabled scanning of DMI to identify machine quirks. Say Y 910 here unless you have verified that your setup is not 911 affected by entries in the DMI blacklist. Required by PNP 912 BIOS code. 913 914config GART_IOMMU 915 bool "Old AMD GART IOMMU support" 916 select IOMMU_HELPER 917 select SWIOTLB 918 depends on X86_64 && PCI && AMD_NB 919 ---help--- 920 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 921 GART based hardware IOMMUs. 922 923 The GART supports full DMA access for devices with 32-bit access 924 limitations, on systems with more than 3 GB. This is usually needed 925 for USB, sound, many IDE/SATA chipsets and some other devices. 926 927 Newer systems typically have a modern AMD IOMMU, supported via 928 the CONFIG_AMD_IOMMU=y config option. 929 930 In normal configurations this driver is only active when needed: 931 there's more than 3 GB of memory and the system contains a 932 32-bit limited device. 933 934 If unsure, say Y. 935 936config MAXSMP 937 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 938 depends on X86_64 && SMP && DEBUG_KERNEL 939 select CPUMASK_OFFSTACK 940 ---help--- 941 Enable maximum number of CPUS and NUMA Nodes for this architecture. 942 If unsure, say N. 943 944# 945# The maximum number of CPUs supported: 946# 947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 948# and which can be configured interactively in the 949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 950# 951# The ranges are different on 32-bit and 64-bit kernels, depending on 952# hardware capabilities and scalability features of the kernel. 953# 954# ( If MAXSMP is enabled we just use the highest possible value and disable 955# interactive configuration. ) 956# 957 958config NR_CPUS_RANGE_BEGIN 959 int 960 default NR_CPUS_RANGE_END if MAXSMP 961 default 1 if !SMP 962 default 2 963 964config NR_CPUS_RANGE_END 965 int 966 depends on X86_32 967 default 64 if SMP && X86_BIGSMP 968 default 8 if SMP && !X86_BIGSMP 969 default 1 if !SMP 970 971config NR_CPUS_RANGE_END 972 int 973 depends on X86_64 974 default 8192 if SMP && CPUMASK_OFFSTACK 975 default 512 if SMP && !CPUMASK_OFFSTACK 976 default 1 if !SMP 977 978config NR_CPUS_DEFAULT 979 int 980 depends on X86_32 981 default 32 if X86_BIGSMP 982 default 8 if SMP 983 default 1 if !SMP 984 985config NR_CPUS_DEFAULT 986 int 987 depends on X86_64 988 default 8192 if MAXSMP 989 default 64 if SMP 990 default 1 if !SMP 991 992config NR_CPUS 993 int "Maximum number of CPUs" if SMP && !MAXSMP 994 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 995 default NR_CPUS_DEFAULT 996 ---help--- 997 This allows you to specify the maximum number of CPUs which this 998 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 999 supported value is 8192, otherwise the maximum value is 512. The 1000 minimum value which makes sense is 2. 1001 1002 This is purely to save memory: each supported CPU adds about 8KB 1003 to the kernel image. 1004 1005config SCHED_SMT 1006 def_bool y if SMP 1007 1008config SCHED_MC 1009 def_bool y 1010 prompt "Multi-core scheduler support" 1011 depends on SMP 1012 ---help--- 1013 Multi-core scheduler support improves the CPU scheduler's decision 1014 making when dealing with multi-core CPU chips at a cost of slightly 1015 increased overhead in some places. If unsure say N here. 1016 1017config SCHED_MC_PRIO 1018 bool "CPU core priorities scheduler support" 1019 depends on SCHED_MC && CPU_SUP_INTEL 1020 select X86_INTEL_PSTATE 1021 select CPU_FREQ 1022 default y 1023 ---help--- 1024 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1025 core ordering determined at manufacturing time, which allows 1026 certain cores to reach higher turbo frequencies (when running 1027 single threaded workloads) than others. 1028 1029 Enabling this kernel feature teaches the scheduler about 1030 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1031 scheduler's CPU selection logic accordingly, so that higher 1032 overall system performance can be achieved. 1033 1034 This feature will have no effect on CPUs without this feature. 1035 1036 If unsure say Y here. 1037 1038config UP_LATE_INIT 1039 def_bool y 1040 depends on !SMP && X86_LOCAL_APIC 1041 1042config X86_UP_APIC 1043 bool "Local APIC support on uniprocessors" if !PCI_MSI 1044 default PCI_MSI 1045 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1046 ---help--- 1047 A local APIC (Advanced Programmable Interrupt Controller) is an 1048 integrated interrupt controller in the CPU. If you have a single-CPU 1049 system which has a processor with a local APIC, you can say Y here to 1050 enable and use it. If you say Y here even though your machine doesn't 1051 have a local APIC, then the kernel will still run with no slowdown at 1052 all. The local APIC supports CPU-generated self-interrupts (timer, 1053 performance counters), and the NMI watchdog which detects hard 1054 lockups. 1055 1056config X86_UP_IOAPIC 1057 bool "IO-APIC support on uniprocessors" 1058 depends on X86_UP_APIC 1059 ---help--- 1060 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1061 SMP-capable replacement for PC-style interrupt controllers. Most 1062 SMP systems and many recent uniprocessor systems have one. 1063 1064 If you have a single-CPU system with an IO-APIC, you can say Y here 1065 to use it. If you say Y here even though your machine doesn't have 1066 an IO-APIC, then the kernel will still run with no slowdown at all. 1067 1068config X86_LOCAL_APIC 1069 def_bool y 1070 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1071 select IRQ_DOMAIN_HIERARCHY 1072 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1073 1074config X86_IO_APIC 1075 def_bool y 1076 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1077 1078config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1079 bool "Reroute for broken boot IRQs" 1080 depends on X86_IO_APIC 1081 ---help--- 1082 This option enables a workaround that fixes a source of 1083 spurious interrupts. This is recommended when threaded 1084 interrupt handling is used on systems where the generation of 1085 superfluous "boot interrupts" cannot be disabled. 1086 1087 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1088 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1089 kernel does during interrupt handling). On chipsets where this 1090 boot IRQ generation cannot be disabled, this workaround keeps 1091 the original IRQ line masked so that only the equivalent "boot 1092 IRQ" is delivered to the CPUs. The workaround also tells the 1093 kernel to set up the IRQ handler on the boot IRQ line. In this 1094 way only one interrupt is delivered to the kernel. Otherwise 1095 the spurious second interrupt may cause the kernel to bring 1096 down (vital) interrupt lines. 1097 1098 Only affects "broken" chipsets. Interrupt sharing may be 1099 increased on these systems. 1100 1101config X86_MCE 1102 bool "Machine Check / overheating reporting" 1103 select GENERIC_ALLOCATOR 1104 default y 1105 ---help--- 1106 Machine Check support allows the processor to notify the 1107 kernel if it detects a problem (e.g. overheating, data corruption). 1108 The action the kernel takes depends on the severity of the problem, 1109 ranging from warning messages to halting the machine. 1110 1111config X86_MCELOG_LEGACY 1112 bool "Support for deprecated /dev/mcelog character device" 1113 depends on X86_MCE 1114 ---help--- 1115 Enable support for /dev/mcelog which is needed by the old mcelog 1116 userspace logging daemon. Consider switching to the new generation 1117 rasdaemon solution. 1118 1119config X86_MCE_INTEL 1120 def_bool y 1121 prompt "Intel MCE features" 1122 depends on X86_MCE && X86_LOCAL_APIC 1123 ---help--- 1124 Additional support for intel specific MCE features such as 1125 the thermal monitor. 1126 1127config X86_MCE_AMD 1128 def_bool y 1129 prompt "AMD MCE features" 1130 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1131 ---help--- 1132 Additional support for AMD specific MCE features such as 1133 the DRAM Error Threshold. 1134 1135config X86_ANCIENT_MCE 1136 bool "Support for old Pentium 5 / WinChip machine checks" 1137 depends on X86_32 && X86_MCE 1138 ---help--- 1139 Include support for machine check handling on old Pentium 5 or WinChip 1140 systems. These typically need to be enabled explicitly on the command 1141 line. 1142 1143config X86_MCE_THRESHOLD 1144 depends on X86_MCE_AMD || X86_MCE_INTEL 1145 def_bool y 1146 1147config X86_MCE_INJECT 1148 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1149 tristate "Machine check injector support" 1150 ---help--- 1151 Provide support for injecting machine checks for testing purposes. 1152 If you don't know what a machine check is and you don't do kernel 1153 QA it is safe to say n. 1154 1155config X86_THERMAL_VECTOR 1156 def_bool y 1157 depends on X86_MCE_INTEL 1158 1159source "arch/x86/events/Kconfig" 1160 1161config X86_LEGACY_VM86 1162 bool "Legacy VM86 support" 1163 depends on X86_32 1164 ---help--- 1165 This option allows user programs to put the CPU into V8086 1166 mode, which is an 80286-era approximation of 16-bit real mode. 1167 1168 Some very old versions of X and/or vbetool require this option 1169 for user mode setting. Similarly, DOSEMU will use it if 1170 available to accelerate real mode DOS programs. However, any 1171 recent version of DOSEMU, X, or vbetool should be fully 1172 functional even without kernel VM86 support, as they will all 1173 fall back to software emulation. Nevertheless, if you are using 1174 a 16-bit DOS program where 16-bit performance matters, vm86 1175 mode might be faster than emulation and you might want to 1176 enable this option. 1177 1178 Note that any app that works on a 64-bit kernel is unlikely to 1179 need this option, as 64-bit kernels don't, and can't, support 1180 V8086 mode. This option is also unrelated to 16-bit protected 1181 mode and is not needed to run most 16-bit programs under Wine. 1182 1183 Enabling this option increases the complexity of the kernel 1184 and slows down exception handling a tiny bit. 1185 1186 If unsure, say N here. 1187 1188config VM86 1189 bool 1190 default X86_LEGACY_VM86 1191 1192config X86_16BIT 1193 bool "Enable support for 16-bit segments" if EXPERT 1194 default y 1195 depends on MODIFY_LDT_SYSCALL 1196 ---help--- 1197 This option is required by programs like Wine to run 16-bit 1198 protected mode legacy code on x86 processors. Disabling 1199 this option saves about 300 bytes on i386, or around 6K text 1200 plus 16K runtime memory on x86-64, 1201 1202config X86_ESPFIX32 1203 def_bool y 1204 depends on X86_16BIT && X86_32 1205 1206config X86_ESPFIX64 1207 def_bool y 1208 depends on X86_16BIT && X86_64 1209 1210config X86_VSYSCALL_EMULATION 1211 bool "Enable vsyscall emulation" if EXPERT 1212 default y 1213 depends on X86_64 1214 ---help--- 1215 This enables emulation of the legacy vsyscall page. Disabling 1216 it is roughly equivalent to booting with vsyscall=none, except 1217 that it will also disable the helpful warning if a program 1218 tries to use a vsyscall. With this option set to N, offending 1219 programs will just segfault, citing addresses of the form 1220 0xffffffffff600?00. 1221 1222 This option is required by many programs built before 2013, and 1223 care should be used even with newer programs if set to N. 1224 1225 Disabling this option saves about 7K of kernel size and 1226 possibly 4K of additional runtime pagetable memory. 1227 1228config X86_IOPL_IOPERM 1229 bool "IOPERM and IOPL Emulation" 1230 default y 1231 ---help--- 1232 This enables the ioperm() and iopl() syscalls which are necessary 1233 for legacy applications. 1234 1235 Legacy IOPL support is an overbroad mechanism which allows user 1236 space aside of accessing all 65536 I/O ports also to disable 1237 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1238 capabilities and permission from potentially active security 1239 modules. 1240 1241 The emulation restricts the functionality of the syscall to 1242 only allowing the full range I/O port access, but prevents the 1243 ability to disable interrupts from user space which would be 1244 granted if the hardware IOPL mechanism would be used. 1245 1246config TOSHIBA 1247 tristate "Toshiba Laptop support" 1248 depends on X86_32 1249 ---help--- 1250 This adds a driver to safely access the System Management Mode of 1251 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1252 not work on models with a Phoenix BIOS. The System Management Mode 1253 is used to set the BIOS and power saving options on Toshiba portables. 1254 1255 For information on utilities to make use of this driver see the 1256 Toshiba Linux utilities web site at: 1257 <http://www.buzzard.org.uk/toshiba/>. 1258 1259 Say Y if you intend to run this kernel on a Toshiba portable. 1260 Say N otherwise. 1261 1262config I8K 1263 tristate "Dell i8k legacy laptop support" 1264 select HWMON 1265 select SENSORS_DELL_SMM 1266 ---help--- 1267 This option enables legacy /proc/i8k userspace interface in hwmon 1268 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1269 temperature and allows controlling fan speeds of Dell laptops via 1270 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1271 it reports also power and hotkey status. For fan speed control is 1272 needed userspace package i8kutils. 1273 1274 Say Y if you intend to run this kernel on old Dell laptops or want to 1275 use userspace package i8kutils. 1276 Say N otherwise. 1277 1278config X86_REBOOTFIXUPS 1279 bool "Enable X86 board specific fixups for reboot" 1280 depends on X86_32 1281 ---help--- 1282 This enables chipset and/or board specific fixups to be done 1283 in order to get reboot to work correctly. This is only needed on 1284 some combinations of hardware and BIOS. The symptom, for which 1285 this config is intended, is when reboot ends with a stalled/hung 1286 system. 1287 1288 Currently, the only fixup is for the Geode machines using 1289 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1290 1291 Say Y if you want to enable the fixup. Currently, it's safe to 1292 enable this option even if you don't need it. 1293 Say N otherwise. 1294 1295config MICROCODE 1296 bool "CPU microcode loading support" 1297 default y 1298 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1299 select FW_LOADER 1300 ---help--- 1301 If you say Y here, you will be able to update the microcode on 1302 Intel and AMD processors. The Intel support is for the IA32 family, 1303 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1304 AMD support is for families 0x10 and later. You will obviously need 1305 the actual microcode binary data itself which is not shipped with 1306 the Linux kernel. 1307 1308 The preferred method to load microcode from a detached initrd is described 1309 in Documentation/x86/microcode.rst. For that you need to enable 1310 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1311 initrd for microcode blobs. 1312 1313 In addition, you can build the microcode into the kernel. For that you 1314 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1315 config option. 1316 1317config MICROCODE_INTEL 1318 bool "Intel microcode loading support" 1319 depends on MICROCODE 1320 default MICROCODE 1321 select FW_LOADER 1322 ---help--- 1323 This options enables microcode patch loading support for Intel 1324 processors. 1325 1326 For the current Intel microcode data package go to 1327 <https://downloadcenter.intel.com> and search for 1328 'Linux Processor Microcode Data File'. 1329 1330config MICROCODE_AMD 1331 bool "AMD microcode loading support" 1332 depends on MICROCODE 1333 select FW_LOADER 1334 ---help--- 1335 If you select this option, microcode patch loading support for AMD 1336 processors will be enabled. 1337 1338config MICROCODE_OLD_INTERFACE 1339 bool "Ancient loading interface (DEPRECATED)" 1340 default n 1341 depends on MICROCODE 1342 ---help--- 1343 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1344 which was used by userspace tools like iucode_tool and microcode.ctl. 1345 It is inadequate because it runs too late to be able to properly 1346 load microcode on a machine and it needs special tools. Instead, you 1347 should've switched to the early loading method with the initrd or 1348 builtin microcode by now: Documentation/x86/microcode.rst 1349 1350config X86_MSR 1351 tristate "/dev/cpu/*/msr - Model-specific register support" 1352 ---help--- 1353 This device gives privileged processes access to the x86 1354 Model-Specific Registers (MSRs). It is a character device with 1355 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1356 MSR accesses are directed to a specific CPU on multi-processor 1357 systems. 1358 1359config X86_CPUID 1360 tristate "/dev/cpu/*/cpuid - CPU information support" 1361 ---help--- 1362 This device gives processes access to the x86 CPUID instruction to 1363 be executed on a specific processor. It is a character device 1364 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1365 /dev/cpu/31/cpuid. 1366 1367choice 1368 prompt "High Memory Support" 1369 default HIGHMEM4G 1370 depends on X86_32 1371 1372config NOHIGHMEM 1373 bool "off" 1374 ---help--- 1375 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1376 However, the address space of 32-bit x86 processors is only 4 1377 Gigabytes large. That means that, if you have a large amount of 1378 physical memory, not all of it can be "permanently mapped" by the 1379 kernel. The physical memory that's not permanently mapped is called 1380 "high memory". 1381 1382 If you are compiling a kernel which will never run on a machine with 1383 more than 1 Gigabyte total physical RAM, answer "off" here (default 1384 choice and suitable for most users). This will result in a "3GB/1GB" 1385 split: 3GB are mapped so that each process sees a 3GB virtual memory 1386 space and the remaining part of the 4GB virtual memory space is used 1387 by the kernel to permanently map as much physical memory as 1388 possible. 1389 1390 If the machine has between 1 and 4 Gigabytes physical RAM, then 1391 answer "4GB" here. 1392 1393 If more than 4 Gigabytes is used then answer "64GB" here. This 1394 selection turns Intel PAE (Physical Address Extension) mode on. 1395 PAE implements 3-level paging on IA32 processors. PAE is fully 1396 supported by Linux, PAE mode is implemented on all recent Intel 1397 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1398 then the kernel will not boot on CPUs that don't support PAE! 1399 1400 The actual amount of total physical memory will either be 1401 auto detected or can be forced by using a kernel command line option 1402 such as "mem=256M". (Try "man bootparam" or see the documentation of 1403 your boot loader (lilo or loadlin) about how to pass options to the 1404 kernel at boot time.) 1405 1406 If unsure, say "off". 1407 1408config HIGHMEM4G 1409 bool "4GB" 1410 ---help--- 1411 Select this if you have a 32-bit processor and between 1 and 4 1412 gigabytes of physical RAM. 1413 1414config HIGHMEM64G 1415 bool "64GB" 1416 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1417 select X86_PAE 1418 ---help--- 1419 Select this if you have a 32-bit processor and more than 4 1420 gigabytes of physical RAM. 1421 1422endchoice 1423 1424choice 1425 prompt "Memory split" if EXPERT 1426 default VMSPLIT_3G 1427 depends on X86_32 1428 ---help--- 1429 Select the desired split between kernel and user memory. 1430 1431 If the address range available to the kernel is less than the 1432 physical memory installed, the remaining memory will be available 1433 as "high memory". Accessing high memory is a little more costly 1434 than low memory, as it needs to be mapped into the kernel first. 1435 Note that increasing the kernel address space limits the range 1436 available to user programs, making the address space there 1437 tighter. Selecting anything other than the default 3G/1G split 1438 will also likely make your kernel incompatible with binary-only 1439 kernel modules. 1440 1441 If you are not absolutely sure what you are doing, leave this 1442 option alone! 1443 1444 config VMSPLIT_3G 1445 bool "3G/1G user/kernel split" 1446 config VMSPLIT_3G_OPT 1447 depends on !X86_PAE 1448 bool "3G/1G user/kernel split (for full 1G low memory)" 1449 config VMSPLIT_2G 1450 bool "2G/2G user/kernel split" 1451 config VMSPLIT_2G_OPT 1452 depends on !X86_PAE 1453 bool "2G/2G user/kernel split (for full 2G low memory)" 1454 config VMSPLIT_1G 1455 bool "1G/3G user/kernel split" 1456endchoice 1457 1458config PAGE_OFFSET 1459 hex 1460 default 0xB0000000 if VMSPLIT_3G_OPT 1461 default 0x80000000 if VMSPLIT_2G 1462 default 0x78000000 if VMSPLIT_2G_OPT 1463 default 0x40000000 if VMSPLIT_1G 1464 default 0xC0000000 1465 depends on X86_32 1466 1467config HIGHMEM 1468 def_bool y 1469 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1470 1471config X86_PAE 1472 bool "PAE (Physical Address Extension) Support" 1473 depends on X86_32 && !HIGHMEM4G 1474 select PHYS_ADDR_T_64BIT 1475 select SWIOTLB 1476 ---help--- 1477 PAE is required for NX support, and furthermore enables 1478 larger swapspace support for non-overcommit purposes. It 1479 has the cost of more pagetable lookup overhead, and also 1480 consumes more pagetable space per process. 1481 1482config X86_5LEVEL 1483 bool "Enable 5-level page tables support" 1484 default y 1485 select DYNAMIC_MEMORY_LAYOUT 1486 select SPARSEMEM_VMEMMAP 1487 depends on X86_64 1488 ---help--- 1489 5-level paging enables access to larger address space: 1490 upto 128 PiB of virtual address space and 4 PiB of 1491 physical address space. 1492 1493 It will be supported by future Intel CPUs. 1494 1495 A kernel with the option enabled can be booted on machines that 1496 support 4- or 5-level paging. 1497 1498 See Documentation/x86/x86_64/5level-paging.rst for more 1499 information. 1500 1501 Say N if unsure. 1502 1503config X86_DIRECT_GBPAGES 1504 def_bool y 1505 depends on X86_64 1506 ---help--- 1507 Certain kernel features effectively disable kernel 1508 linear 1 GB mappings (even if the CPU otherwise 1509 supports them), so don't confuse the user by printing 1510 that we have them enabled. 1511 1512config X86_CPA_STATISTICS 1513 bool "Enable statistic for Change Page Attribute" 1514 depends on DEBUG_FS 1515 ---help--- 1516 Expose statistics about the Change Page Attribute mechanims, which 1517 helps to determine the effectiveness of preserving large and huge 1518 page mappings when mapping protections are changed. 1519 1520config AMD_MEM_ENCRYPT 1521 bool "AMD Secure Memory Encryption (SME) support" 1522 depends on X86_64 && CPU_SUP_AMD 1523 select DYNAMIC_PHYSICAL_MASK 1524 select ARCH_USE_MEMREMAP_PROT 1525 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1526 ---help--- 1527 Say yes to enable support for the encryption of system memory. 1528 This requires an AMD processor that supports Secure Memory 1529 Encryption (SME). 1530 1531config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1532 bool "Activate AMD Secure Memory Encryption (SME) by default" 1533 default y 1534 depends on AMD_MEM_ENCRYPT 1535 ---help--- 1536 Say yes to have system memory encrypted by default if running on 1537 an AMD processor that supports Secure Memory Encryption (SME). 1538 1539 If set to Y, then the encryption of system memory can be 1540 deactivated with the mem_encrypt=off command line option. 1541 1542 If set to N, then the encryption of system memory can be 1543 activated with the mem_encrypt=on command line option. 1544 1545# Common NUMA Features 1546config NUMA 1547 bool "Numa Memory Allocation and Scheduler Support" 1548 depends on SMP 1549 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1550 default y if X86_BIGSMP 1551 ---help--- 1552 Enable NUMA (Non Uniform Memory Access) support. 1553 1554 The kernel will try to allocate memory used by a CPU on the 1555 local memory controller of the CPU and add some more 1556 NUMA awareness to the kernel. 1557 1558 For 64-bit this is recommended if the system is Intel Core i7 1559 (or later), AMD Opteron, or EM64T NUMA. 1560 1561 For 32-bit this is only needed if you boot a 32-bit 1562 kernel on a 64-bit NUMA platform. 1563 1564 Otherwise, you should say N. 1565 1566config AMD_NUMA 1567 def_bool y 1568 prompt "Old style AMD Opteron NUMA detection" 1569 depends on X86_64 && NUMA && PCI 1570 ---help--- 1571 Enable AMD NUMA node topology detection. You should say Y here if 1572 you have a multi processor AMD system. This uses an old method to 1573 read the NUMA configuration directly from the builtin Northbridge 1574 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1575 which also takes priority if both are compiled in. 1576 1577config X86_64_ACPI_NUMA 1578 def_bool y 1579 prompt "ACPI NUMA detection" 1580 depends on X86_64 && NUMA && ACPI && PCI 1581 select ACPI_NUMA 1582 ---help--- 1583 Enable ACPI SRAT based node topology detection. 1584 1585# Some NUMA nodes have memory ranges that span 1586# other nodes. Even though a pfn is valid and 1587# between a node's start and end pfns, it may not 1588# reside on that node. See memmap_init_zone() 1589# for details. 1590config NODES_SPAN_OTHER_NODES 1591 def_bool y 1592 depends on X86_64_ACPI_NUMA 1593 1594config NUMA_EMU 1595 bool "NUMA emulation" 1596 depends on NUMA 1597 ---help--- 1598 Enable NUMA emulation. A flat machine will be split 1599 into virtual nodes when booted with "numa=fake=N", where N is the 1600 number of nodes. This is only useful for debugging. 1601 1602config NODES_SHIFT 1603 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1604 range 1 10 1605 default "10" if MAXSMP 1606 default "6" if X86_64 1607 default "3" 1608 depends on NEED_MULTIPLE_NODES 1609 ---help--- 1610 Specify the maximum number of NUMA Nodes available on the target 1611 system. Increases memory reserved to accommodate various tables. 1612 1613config ARCH_HAVE_MEMORY_PRESENT 1614 def_bool y 1615 depends on X86_32 && DISCONTIGMEM 1616 1617config ARCH_FLATMEM_ENABLE 1618 def_bool y 1619 depends on X86_32 && !NUMA 1620 1621config ARCH_DISCONTIGMEM_ENABLE 1622 def_bool n 1623 depends on NUMA && X86_32 1624 depends on BROKEN 1625 1626config ARCH_SPARSEMEM_ENABLE 1627 def_bool y 1628 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1629 select SPARSEMEM_STATIC if X86_32 1630 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1631 1632config ARCH_SPARSEMEM_DEFAULT 1633 def_bool X86_64 || (NUMA && X86_32) 1634 1635config ARCH_SELECT_MEMORY_MODEL 1636 def_bool y 1637 depends on ARCH_SPARSEMEM_ENABLE 1638 1639config ARCH_MEMORY_PROBE 1640 bool "Enable sysfs memory/probe interface" 1641 depends on X86_64 && MEMORY_HOTPLUG 1642 help 1643 This option enables a sysfs memory/probe interface for testing. 1644 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1645 If you are unsure how to answer this question, answer N. 1646 1647config ARCH_PROC_KCORE_TEXT 1648 def_bool y 1649 depends on X86_64 && PROC_KCORE 1650 1651config ILLEGAL_POINTER_VALUE 1652 hex 1653 default 0 if X86_32 1654 default 0xdead000000000000 if X86_64 1655 1656config X86_PMEM_LEGACY_DEVICE 1657 bool 1658 1659config X86_PMEM_LEGACY 1660 tristate "Support non-standard NVDIMMs and ADR protected memory" 1661 depends on PHYS_ADDR_T_64BIT 1662 depends on BLK_DEV 1663 select X86_PMEM_LEGACY_DEVICE 1664 select LIBNVDIMM 1665 help 1666 Treat memory marked using the non-standard e820 type of 12 as used 1667 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1668 The kernel will offer these regions to the 'pmem' driver so 1669 they can be used for persistent storage. 1670 1671 Say Y if unsure. 1672 1673config HIGHPTE 1674 bool "Allocate 3rd-level pagetables from highmem" 1675 depends on HIGHMEM 1676 ---help--- 1677 The VM uses one page table entry for each page of physical memory. 1678 For systems with a lot of RAM, this can be wasteful of precious 1679 low memory. Setting this option will put user-space page table 1680 entries in high memory. 1681 1682config X86_CHECK_BIOS_CORRUPTION 1683 bool "Check for low memory corruption" 1684 ---help--- 1685 Periodically check for memory corruption in low memory, which 1686 is suspected to be caused by BIOS. Even when enabled in the 1687 configuration, it is disabled at runtime. Enable it by 1688 setting "memory_corruption_check=1" on the kernel command 1689 line. By default it scans the low 64k of memory every 60 1690 seconds; see the memory_corruption_check_size and 1691 memory_corruption_check_period parameters in 1692 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1693 1694 When enabled with the default parameters, this option has 1695 almost no overhead, as it reserves a relatively small amount 1696 of memory and scans it infrequently. It both detects corruption 1697 and prevents it from affecting the running system. 1698 1699 It is, however, intended as a diagnostic tool; if repeatable 1700 BIOS-originated corruption always affects the same memory, 1701 you can use memmap= to prevent the kernel from using that 1702 memory. 1703 1704config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1705 bool "Set the default setting of memory_corruption_check" 1706 depends on X86_CHECK_BIOS_CORRUPTION 1707 default y 1708 ---help--- 1709 Set whether the default state of memory_corruption_check is 1710 on or off. 1711 1712config X86_RESERVE_LOW 1713 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1714 default 64 1715 range 4 640 1716 ---help--- 1717 Specify the amount of low memory to reserve for the BIOS. 1718 1719 The first page contains BIOS data structures that the kernel 1720 must not use, so that page must always be reserved. 1721 1722 By default we reserve the first 64K of physical RAM, as a 1723 number of BIOSes are known to corrupt that memory range 1724 during events such as suspend/resume or monitor cable 1725 insertion, so it must not be used by the kernel. 1726 1727 You can set this to 4 if you are absolutely sure that you 1728 trust the BIOS to get all its memory reservations and usages 1729 right. If you know your BIOS have problems beyond the 1730 default 64K area, you can set this to 640 to avoid using the 1731 entire low memory range. 1732 1733 If you have doubts about the BIOS (e.g. suspend/resume does 1734 not work or there's kernel crashes after certain hardware 1735 hotplug events) then you might want to enable 1736 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1737 typical corruption patterns. 1738 1739 Leave this to the default value of 64 if you are unsure. 1740 1741config MATH_EMULATION 1742 bool 1743 depends on MODIFY_LDT_SYSCALL 1744 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1745 ---help--- 1746 Linux can emulate a math coprocessor (used for floating point 1747 operations) if you don't have one. 486DX and Pentium processors have 1748 a math coprocessor built in, 486SX and 386 do not, unless you added 1749 a 487DX or 387, respectively. (The messages during boot time can 1750 give you some hints here ["man dmesg"].) Everyone needs either a 1751 coprocessor or this emulation. 1752 1753 If you don't have a math coprocessor, you need to say Y here; if you 1754 say Y here even though you have a coprocessor, the coprocessor will 1755 be used nevertheless. (This behavior can be changed with the kernel 1756 command line option "no387", which comes handy if your coprocessor 1757 is broken. Try "man bootparam" or see the documentation of your boot 1758 loader (lilo or loadlin) about how to pass options to the kernel at 1759 boot time.) This means that it is a good idea to say Y here if you 1760 intend to use this kernel on different machines. 1761 1762 More information about the internals of the Linux math coprocessor 1763 emulation can be found in <file:arch/x86/math-emu/README>. 1764 1765 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1766 kernel, it won't hurt. 1767 1768config MTRR 1769 def_bool y 1770 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1771 ---help--- 1772 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1773 the Memory Type Range Registers (MTRRs) may be used to control 1774 processor access to memory ranges. This is most useful if you have 1775 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1776 allows bus write transfers to be combined into a larger transfer 1777 before bursting over the PCI/AGP bus. This can increase performance 1778 of image write operations 2.5 times or more. Saying Y here creates a 1779 /proc/mtrr file which may be used to manipulate your processor's 1780 MTRRs. Typically the X server should use this. 1781 1782 This code has a reasonably generic interface so that similar 1783 control registers on other processors can be easily supported 1784 as well: 1785 1786 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1787 Registers (ARRs) which provide a similar functionality to MTRRs. For 1788 these, the ARRs are used to emulate the MTRRs. 1789 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1790 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1791 write-combining. All of these processors are supported by this code 1792 and it makes sense to say Y here if you have one of them. 1793 1794 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1795 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1796 can lead to all sorts of problems, so it's good to say Y here. 1797 1798 You can safely say Y even if your machine doesn't have MTRRs, you'll 1799 just add about 9 KB to your kernel. 1800 1801 See <file:Documentation/x86/mtrr.rst> for more information. 1802 1803config MTRR_SANITIZER 1804 def_bool y 1805 prompt "MTRR cleanup support" 1806 depends on MTRR 1807 ---help--- 1808 Convert MTRR layout from continuous to discrete, so X drivers can 1809 add writeback entries. 1810 1811 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1812 The largest mtrr entry size for a continuous block can be set with 1813 mtrr_chunk_size. 1814 1815 If unsure, say Y. 1816 1817config MTRR_SANITIZER_ENABLE_DEFAULT 1818 int "MTRR cleanup enable value (0-1)" 1819 range 0 1 1820 default "0" 1821 depends on MTRR_SANITIZER 1822 ---help--- 1823 Enable mtrr cleanup default value 1824 1825config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1826 int "MTRR cleanup spare reg num (0-7)" 1827 range 0 7 1828 default "1" 1829 depends on MTRR_SANITIZER 1830 ---help--- 1831 mtrr cleanup spare entries default, it can be changed via 1832 mtrr_spare_reg_nr=N on the kernel command line. 1833 1834config X86_PAT 1835 def_bool y 1836 prompt "x86 PAT support" if EXPERT 1837 depends on MTRR 1838 ---help--- 1839 Use PAT attributes to setup page level cache control. 1840 1841 PATs are the modern equivalents of MTRRs and are much more 1842 flexible than MTRRs. 1843 1844 Say N here if you see bootup problems (boot crash, boot hang, 1845 spontaneous reboots) or a non-working video driver. 1846 1847 If unsure, say Y. 1848 1849config ARCH_USES_PG_UNCACHED 1850 def_bool y 1851 depends on X86_PAT 1852 1853config ARCH_RANDOM 1854 def_bool y 1855 prompt "x86 architectural random number generator" if EXPERT 1856 ---help--- 1857 Enable the x86 architectural RDRAND instruction 1858 (Intel Bull Mountain technology) to generate random numbers. 1859 If supported, this is a high bandwidth, cryptographically 1860 secure hardware random number generator. 1861 1862config X86_SMAP 1863 def_bool y 1864 prompt "Supervisor Mode Access Prevention" if EXPERT 1865 ---help--- 1866 Supervisor Mode Access Prevention (SMAP) is a security 1867 feature in newer Intel processors. There is a small 1868 performance cost if this enabled and turned on; there is 1869 also a small increase in the kernel size if this is enabled. 1870 1871 If unsure, say Y. 1872 1873config X86_UMIP 1874 def_bool y 1875 depends on CPU_SUP_INTEL || CPU_SUP_AMD 1876 prompt "User Mode Instruction Prevention" if EXPERT 1877 ---help--- 1878 User Mode Instruction Prevention (UMIP) is a security feature in 1879 some x86 processors. If enabled, a general protection fault is 1880 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1881 executed in user mode. These instructions unnecessarily expose 1882 information about the hardware state. 1883 1884 The vast majority of applications do not use these instructions. 1885 For the very few that do, software emulation is provided in 1886 specific cases in protected and virtual-8086 modes. Emulated 1887 results are dummy. 1888 1889config X86_INTEL_MPX 1890 prompt "Intel MPX (Memory Protection Extensions)" 1891 def_bool n 1892 # Note: only available in 64-bit mode due to VMA flags shortage 1893 depends on CPU_SUP_INTEL && X86_64 1894 select ARCH_USES_HIGH_VMA_FLAGS 1895 ---help--- 1896 MPX provides hardware features that can be used in 1897 conjunction with compiler-instrumented code to check 1898 memory references. It is designed to detect buffer 1899 overflow or underflow bugs. 1900 1901 This option enables running applications which are 1902 instrumented or otherwise use MPX. It does not use MPX 1903 itself inside the kernel or to protect the kernel 1904 against bad memory references. 1905 1906 Enabling this option will make the kernel larger: 1907 ~8k of kernel text and 36 bytes of data on a 64-bit 1908 defconfig. It adds a long to the 'mm_struct' which 1909 will increase the kernel memory overhead of each 1910 process and adds some branches to paths used during 1911 exec() and munmap(). 1912 1913 For details, see Documentation/x86/intel_mpx.rst 1914 1915 If unsure, say N. 1916 1917config X86_INTEL_MEMORY_PROTECTION_KEYS 1918 prompt "Intel Memory Protection Keys" 1919 def_bool y 1920 # Note: only available in 64-bit mode 1921 depends on CPU_SUP_INTEL && X86_64 1922 select ARCH_USES_HIGH_VMA_FLAGS 1923 select ARCH_HAS_PKEYS 1924 ---help--- 1925 Memory Protection Keys provides a mechanism for enforcing 1926 page-based protections, but without requiring modification of the 1927 page tables when an application changes protection domains. 1928 1929 For details, see Documentation/core-api/protection-keys.rst 1930 1931 If unsure, say y. 1932 1933choice 1934 prompt "TSX enable mode" 1935 depends on CPU_SUP_INTEL 1936 default X86_INTEL_TSX_MODE_OFF 1937 help 1938 Intel's TSX (Transactional Synchronization Extensions) feature 1939 allows to optimize locking protocols through lock elision which 1940 can lead to a noticeable performance boost. 1941 1942 On the other hand it has been shown that TSX can be exploited 1943 to form side channel attacks (e.g. TAA) and chances are there 1944 will be more of those attacks discovered in the future. 1945 1946 Therefore TSX is not enabled by default (aka tsx=off). An admin 1947 might override this decision by tsx=on the command line parameter. 1948 Even with TSX enabled, the kernel will attempt to enable the best 1949 possible TAA mitigation setting depending on the microcode available 1950 for the particular machine. 1951 1952 This option allows to set the default tsx mode between tsx=on, =off 1953 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1954 details. 1955 1956 Say off if not sure, auto if TSX is in use but it should be used on safe 1957 platforms or on if TSX is in use and the security aspect of tsx is not 1958 relevant. 1959 1960config X86_INTEL_TSX_MODE_OFF 1961 bool "off" 1962 help 1963 TSX is disabled if possible - equals to tsx=off command line parameter. 1964 1965config X86_INTEL_TSX_MODE_ON 1966 bool "on" 1967 help 1968 TSX is always enabled on TSX capable HW - equals the tsx=on command 1969 line parameter. 1970 1971config X86_INTEL_TSX_MODE_AUTO 1972 bool "auto" 1973 help 1974 TSX is enabled on TSX capable HW that is believed to be safe against 1975 side channel attacks- equals the tsx=auto command line parameter. 1976endchoice 1977 1978config EFI 1979 bool "EFI runtime service support" 1980 depends on ACPI 1981 select UCS2_STRING 1982 select EFI_RUNTIME_WRAPPERS 1983 ---help--- 1984 This enables the kernel to use EFI runtime services that are 1985 available (such as the EFI variable services). 1986 1987 This option is only useful on systems that have EFI firmware. 1988 In addition, you should use the latest ELILO loader available 1989 at <http://elilo.sourceforge.net> in order to take advantage 1990 of EFI runtime services. However, even with this option, the 1991 resultant kernel should continue to boot on existing non-EFI 1992 platforms. 1993 1994config EFI_STUB 1995 bool "EFI stub support" 1996 depends on EFI && !X86_USE_3DNOW 1997 select RELOCATABLE 1998 ---help--- 1999 This kernel feature allows a bzImage to be loaded directly 2000 by EFI firmware without the use of a bootloader. 2001 2002 See Documentation/admin-guide/efi-stub.rst for more information. 2003 2004config EFI_MIXED 2005 bool "EFI mixed-mode support" 2006 depends on EFI_STUB && X86_64 2007 ---help--- 2008 Enabling this feature allows a 64-bit kernel to be booted 2009 on a 32-bit firmware, provided that your CPU supports 64-bit 2010 mode. 2011 2012 Note that it is not possible to boot a mixed-mode enabled 2013 kernel via the EFI boot stub - a bootloader that supports 2014 the EFI handover protocol must be used. 2015 2016 If unsure, say N. 2017 2018config SECCOMP 2019 def_bool y 2020 prompt "Enable seccomp to safely compute untrusted bytecode" 2021 ---help--- 2022 This kernel feature is useful for number crunching applications 2023 that may need to compute untrusted bytecode during their 2024 execution. By using pipes or other transports made available to 2025 the process as file descriptors supporting the read/write 2026 syscalls, it's possible to isolate those applications in 2027 their own address space using seccomp. Once seccomp is 2028 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 2029 and the task is only allowed to execute a few safe syscalls 2030 defined by each seccomp mode. 2031 2032 If unsure, say Y. Only embedded should say N here. 2033 2034source "kernel/Kconfig.hz" 2035 2036config KEXEC 2037 bool "kexec system call" 2038 select KEXEC_CORE 2039 ---help--- 2040 kexec is a system call that implements the ability to shutdown your 2041 current kernel, and to start another kernel. It is like a reboot 2042 but it is independent of the system firmware. And like a reboot 2043 you can start any kernel with it, not just Linux. 2044 2045 The name comes from the similarity to the exec system call. 2046 2047 It is an ongoing process to be certain the hardware in a machine 2048 is properly shutdown, so do not be surprised if this code does not 2049 initially work for you. As of this writing the exact hardware 2050 interface is strongly in flux, so no good recommendation can be 2051 made. 2052 2053config KEXEC_FILE 2054 bool "kexec file based system call" 2055 select KEXEC_CORE 2056 select BUILD_BIN2C 2057 depends on X86_64 2058 depends on CRYPTO=y 2059 depends on CRYPTO_SHA256=y 2060 ---help--- 2061 This is new version of kexec system call. This system call is 2062 file based and takes file descriptors as system call argument 2063 for kernel and initramfs as opposed to list of segments as 2064 accepted by previous system call. 2065 2066config ARCH_HAS_KEXEC_PURGATORY 2067 def_bool KEXEC_FILE 2068 2069config KEXEC_SIG 2070 bool "Verify kernel signature during kexec_file_load() syscall" 2071 depends on KEXEC_FILE 2072 ---help--- 2073 2074 This option makes the kexec_file_load() syscall check for a valid 2075 signature of the kernel image. The image can still be loaded without 2076 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2077 there's a signature that we can check, then it must be valid. 2078 2079 In addition to this option, you need to enable signature 2080 verification for the corresponding kernel image type being 2081 loaded in order for this to work. 2082 2083config KEXEC_SIG_FORCE 2084 bool "Require a valid signature in kexec_file_load() syscall" 2085 depends on KEXEC_SIG 2086 ---help--- 2087 This option makes kernel signature verification mandatory for 2088 the kexec_file_load() syscall. 2089 2090config KEXEC_BZIMAGE_VERIFY_SIG 2091 bool "Enable bzImage signature verification support" 2092 depends on KEXEC_SIG 2093 depends on SIGNED_PE_FILE_VERIFICATION 2094 select SYSTEM_TRUSTED_KEYRING 2095 ---help--- 2096 Enable bzImage signature verification support. 2097 2098config CRASH_DUMP 2099 bool "kernel crash dumps" 2100 depends on X86_64 || (X86_32 && HIGHMEM) 2101 ---help--- 2102 Generate crash dump after being started by kexec. 2103 This should be normally only set in special crash dump kernels 2104 which are loaded in the main kernel with kexec-tools into 2105 a specially reserved region and then later executed after 2106 a crash by kdump/kexec. The crash dump kernel must be compiled 2107 to a memory address not used by the main kernel or BIOS using 2108 PHYSICAL_START, or it must be built as a relocatable image 2109 (CONFIG_RELOCATABLE=y). 2110 For more details see Documentation/admin-guide/kdump/kdump.rst 2111 2112config KEXEC_JUMP 2113 bool "kexec jump" 2114 depends on KEXEC && HIBERNATION 2115 ---help--- 2116 Jump between original kernel and kexeced kernel and invoke 2117 code in physical address mode via KEXEC 2118 2119config PHYSICAL_START 2120 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2121 default "0x1000000" 2122 ---help--- 2123 This gives the physical address where the kernel is loaded. 2124 2125 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2126 bzImage will decompress itself to above physical address and 2127 run from there. Otherwise, bzImage will run from the address where 2128 it has been loaded by the boot loader and will ignore above physical 2129 address. 2130 2131 In normal kdump cases one does not have to set/change this option 2132 as now bzImage can be compiled as a completely relocatable image 2133 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2134 address. This option is mainly useful for the folks who don't want 2135 to use a bzImage for capturing the crash dump and want to use a 2136 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2137 to be specifically compiled to run from a specific memory area 2138 (normally a reserved region) and this option comes handy. 2139 2140 So if you are using bzImage for capturing the crash dump, 2141 leave the value here unchanged to 0x1000000 and set 2142 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2143 for capturing the crash dump change this value to start of 2144 the reserved region. In other words, it can be set based on 2145 the "X" value as specified in the "crashkernel=YM@XM" 2146 command line boot parameter passed to the panic-ed 2147 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2148 for more details about crash dumps. 2149 2150 Usage of bzImage for capturing the crash dump is recommended as 2151 one does not have to build two kernels. Same kernel can be used 2152 as production kernel and capture kernel. Above option should have 2153 gone away after relocatable bzImage support is introduced. But it 2154 is present because there are users out there who continue to use 2155 vmlinux for dump capture. This option should go away down the 2156 line. 2157 2158 Don't change this unless you know what you are doing. 2159 2160config RELOCATABLE 2161 bool "Build a relocatable kernel" 2162 default y 2163 ---help--- 2164 This builds a kernel image that retains relocation information 2165 so it can be loaded someplace besides the default 1MB. 2166 The relocations tend to make the kernel binary about 10% larger, 2167 but are discarded at runtime. 2168 2169 One use is for the kexec on panic case where the recovery kernel 2170 must live at a different physical address than the primary 2171 kernel. 2172 2173 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2174 it has been loaded at and the compile time physical address 2175 (CONFIG_PHYSICAL_START) is used as the minimum location. 2176 2177config RANDOMIZE_BASE 2178 bool "Randomize the address of the kernel image (KASLR)" 2179 depends on RELOCATABLE 2180 default y 2181 ---help--- 2182 In support of Kernel Address Space Layout Randomization (KASLR), 2183 this randomizes the physical address at which the kernel image 2184 is decompressed and the virtual address where the kernel 2185 image is mapped, as a security feature that deters exploit 2186 attempts relying on knowledge of the location of kernel 2187 code internals. 2188 2189 On 64-bit, the kernel physical and virtual addresses are 2190 randomized separately. The physical address will be anywhere 2191 between 16MB and the top of physical memory (up to 64TB). The 2192 virtual address will be randomized from 16MB up to 1GB (9 bits 2193 of entropy). Note that this also reduces the memory space 2194 available to kernel modules from 1.5GB to 1GB. 2195 2196 On 32-bit, the kernel physical and virtual addresses are 2197 randomized together. They will be randomized from 16MB up to 2198 512MB (8 bits of entropy). 2199 2200 Entropy is generated using the RDRAND instruction if it is 2201 supported. If RDTSC is supported, its value is mixed into 2202 the entropy pool as well. If neither RDRAND nor RDTSC are 2203 supported, then entropy is read from the i8254 timer. The 2204 usable entropy is limited by the kernel being built using 2205 2GB addressing, and that PHYSICAL_ALIGN must be at a 2206 minimum of 2MB. As a result, only 10 bits of entropy are 2207 theoretically possible, but the implementations are further 2208 limited due to memory layouts. 2209 2210 If unsure, say Y. 2211 2212# Relocation on x86 needs some additional build support 2213config X86_NEED_RELOCS 2214 def_bool y 2215 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2216 2217config PHYSICAL_ALIGN 2218 hex "Alignment value to which kernel should be aligned" 2219 default "0x200000" 2220 range 0x2000 0x1000000 if X86_32 2221 range 0x200000 0x1000000 if X86_64 2222 ---help--- 2223 This value puts the alignment restrictions on physical address 2224 where kernel is loaded and run from. Kernel is compiled for an 2225 address which meets above alignment restriction. 2226 2227 If bootloader loads the kernel at a non-aligned address and 2228 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2229 address aligned to above value and run from there. 2230 2231 If bootloader loads the kernel at a non-aligned address and 2232 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2233 load address and decompress itself to the address it has been 2234 compiled for and run from there. The address for which kernel is 2235 compiled already meets above alignment restrictions. Hence the 2236 end result is that kernel runs from a physical address meeting 2237 above alignment restrictions. 2238 2239 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2240 this value must be a multiple of 0x200000. 2241 2242 Don't change this unless you know what you are doing. 2243 2244config DYNAMIC_MEMORY_LAYOUT 2245 bool 2246 ---help--- 2247 This option makes base addresses of vmalloc and vmemmap as well as 2248 __PAGE_OFFSET movable during boot. 2249 2250config RANDOMIZE_MEMORY 2251 bool "Randomize the kernel memory sections" 2252 depends on X86_64 2253 depends on RANDOMIZE_BASE 2254 select DYNAMIC_MEMORY_LAYOUT 2255 default RANDOMIZE_BASE 2256 ---help--- 2257 Randomizes the base virtual address of kernel memory sections 2258 (physical memory mapping, vmalloc & vmemmap). This security feature 2259 makes exploits relying on predictable memory locations less reliable. 2260 2261 The order of allocations remains unchanged. Entropy is generated in 2262 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2263 configuration have in average 30,000 different possible virtual 2264 addresses for each memory section. 2265 2266 If unsure, say Y. 2267 2268config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2269 hex "Physical memory mapping padding" if EXPERT 2270 depends on RANDOMIZE_MEMORY 2271 default "0xa" if MEMORY_HOTPLUG 2272 default "0x0" 2273 range 0x1 0x40 if MEMORY_HOTPLUG 2274 range 0x0 0x40 2275 ---help--- 2276 Define the padding in terabytes added to the existing physical 2277 memory size during kernel memory randomization. It is useful 2278 for memory hotplug support but reduces the entropy available for 2279 address randomization. 2280 2281 If unsure, leave at the default value. 2282 2283config HOTPLUG_CPU 2284 def_bool y 2285 depends on SMP 2286 2287config BOOTPARAM_HOTPLUG_CPU0 2288 bool "Set default setting of cpu0_hotpluggable" 2289 depends on HOTPLUG_CPU 2290 ---help--- 2291 Set whether default state of cpu0_hotpluggable is on or off. 2292 2293 Say Y here to enable CPU0 hotplug by default. If this switch 2294 is turned on, there is no need to give cpu0_hotplug kernel 2295 parameter and the CPU0 hotplug feature is enabled by default. 2296 2297 Please note: there are two known CPU0 dependencies if you want 2298 to enable the CPU0 hotplug feature either by this switch or by 2299 cpu0_hotplug kernel parameter. 2300 2301 First, resume from hibernate or suspend always starts from CPU0. 2302 So hibernate and suspend are prevented if CPU0 is offline. 2303 2304 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2305 offline if any interrupt can not migrate out of CPU0. There may 2306 be other CPU0 dependencies. 2307 2308 Please make sure the dependencies are under your control before 2309 you enable this feature. 2310 2311 Say N if you don't want to enable CPU0 hotplug feature by default. 2312 You still can enable the CPU0 hotplug feature at boot by kernel 2313 parameter cpu0_hotplug. 2314 2315config DEBUG_HOTPLUG_CPU0 2316 def_bool n 2317 prompt "Debug CPU0 hotplug" 2318 depends on HOTPLUG_CPU 2319 ---help--- 2320 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2321 soon as possible and boots up userspace with CPU0 offlined. User 2322 can online CPU0 back after boot time. 2323 2324 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2325 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2326 compilation or giving cpu0_hotplug kernel parameter at boot. 2327 2328 If unsure, say N. 2329 2330config COMPAT_VDSO 2331 def_bool n 2332 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2333 depends on COMPAT_32 2334 ---help--- 2335 Certain buggy versions of glibc will crash if they are 2336 presented with a 32-bit vDSO that is not mapped at the address 2337 indicated in its segment table. 2338 2339 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2340 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2341 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2342 the only released version with the bug, but OpenSUSE 9 2343 contains a buggy "glibc 2.3.2". 2344 2345 The symptom of the bug is that everything crashes on startup, saying: 2346 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2347 2348 Saying Y here changes the default value of the vdso32 boot 2349 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2350 This works around the glibc bug but hurts performance. 2351 2352 If unsure, say N: if you are compiling your own kernel, you 2353 are unlikely to be using a buggy version of glibc. 2354 2355choice 2356 prompt "vsyscall table for legacy applications" 2357 depends on X86_64 2358 default LEGACY_VSYSCALL_XONLY 2359 help 2360 Legacy user code that does not know how to find the vDSO expects 2361 to be able to issue three syscalls by calling fixed addresses in 2362 kernel space. Since this location is not randomized with ASLR, 2363 it can be used to assist security vulnerability exploitation. 2364 2365 This setting can be changed at boot time via the kernel command 2366 line parameter vsyscall=[emulate|xonly|none]. 2367 2368 On a system with recent enough glibc (2.14 or newer) and no 2369 static binaries, you can say None without a performance penalty 2370 to improve security. 2371 2372 If unsure, select "Emulate execution only". 2373 2374 config LEGACY_VSYSCALL_EMULATE 2375 bool "Full emulation" 2376 help 2377 The kernel traps and emulates calls into the fixed vsyscall 2378 address mapping. This makes the mapping non-executable, but 2379 it still contains readable known contents, which could be 2380 used in certain rare security vulnerability exploits. This 2381 configuration is recommended when using legacy userspace 2382 that still uses vsyscalls along with legacy binary 2383 instrumentation tools that require code to be readable. 2384 2385 An example of this type of legacy userspace is running 2386 Pin on an old binary that still uses vsyscalls. 2387 2388 config LEGACY_VSYSCALL_XONLY 2389 bool "Emulate execution only" 2390 help 2391 The kernel traps and emulates calls into the fixed vsyscall 2392 address mapping and does not allow reads. This 2393 configuration is recommended when userspace might use the 2394 legacy vsyscall area but support for legacy binary 2395 instrumentation of legacy code is not needed. It mitigates 2396 certain uses of the vsyscall area as an ASLR-bypassing 2397 buffer. 2398 2399 config LEGACY_VSYSCALL_NONE 2400 bool "None" 2401 help 2402 There will be no vsyscall mapping at all. This will 2403 eliminate any risk of ASLR bypass due to the vsyscall 2404 fixed address mapping. Attempts to use the vsyscalls 2405 will be reported to dmesg, so that either old or 2406 malicious userspace programs can be identified. 2407 2408endchoice 2409 2410config CMDLINE_BOOL 2411 bool "Built-in kernel command line" 2412 ---help--- 2413 Allow for specifying boot arguments to the kernel at 2414 build time. On some systems (e.g. embedded ones), it is 2415 necessary or convenient to provide some or all of the 2416 kernel boot arguments with the kernel itself (that is, 2417 to not rely on the boot loader to provide them.) 2418 2419 To compile command line arguments into the kernel, 2420 set this option to 'Y', then fill in the 2421 boot arguments in CONFIG_CMDLINE. 2422 2423 Systems with fully functional boot loaders (i.e. non-embedded) 2424 should leave this option set to 'N'. 2425 2426config CMDLINE 2427 string "Built-in kernel command string" 2428 depends on CMDLINE_BOOL 2429 default "" 2430 ---help--- 2431 Enter arguments here that should be compiled into the kernel 2432 image and used at boot time. If the boot loader provides a 2433 command line at boot time, it is appended to this string to 2434 form the full kernel command line, when the system boots. 2435 2436 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2437 change this behavior. 2438 2439 In most cases, the command line (whether built-in or provided 2440 by the boot loader) should specify the device for the root 2441 file system. 2442 2443config CMDLINE_OVERRIDE 2444 bool "Built-in command line overrides boot loader arguments" 2445 depends on CMDLINE_BOOL 2446 ---help--- 2447 Set this option to 'Y' to have the kernel ignore the boot loader 2448 command line, and use ONLY the built-in command line. 2449 2450 This is used to work around broken boot loaders. This should 2451 be set to 'N' under normal conditions. 2452 2453config MODIFY_LDT_SYSCALL 2454 bool "Enable the LDT (local descriptor table)" if EXPERT 2455 default y 2456 ---help--- 2457 Linux can allow user programs to install a per-process x86 2458 Local Descriptor Table (LDT) using the modify_ldt(2) system 2459 call. This is required to run 16-bit or segmented code such as 2460 DOSEMU or some Wine programs. It is also used by some very old 2461 threading libraries. 2462 2463 Enabling this feature adds a small amount of overhead to 2464 context switches and increases the low-level kernel attack 2465 surface. Disabling it removes the modify_ldt(2) system call. 2466 2467 Saying 'N' here may make sense for embedded or server kernels. 2468 2469source "kernel/livepatch/Kconfig" 2470 2471endmenu 2472 2473config ARCH_HAS_ADD_PAGES 2474 def_bool y 2475 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2476 2477config ARCH_ENABLE_MEMORY_HOTPLUG 2478 def_bool y 2479 depends on X86_64 || (X86_32 && HIGHMEM) 2480 2481config ARCH_ENABLE_MEMORY_HOTREMOVE 2482 def_bool y 2483 depends on MEMORY_HOTPLUG 2484 2485config USE_PERCPU_NUMA_NODE_ID 2486 def_bool y 2487 depends on NUMA 2488 2489config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2490 def_bool y 2491 depends on X86_64 || X86_PAE 2492 2493config ARCH_ENABLE_HUGEPAGE_MIGRATION 2494 def_bool y 2495 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2496 2497config ARCH_ENABLE_THP_MIGRATION 2498 def_bool y 2499 depends on X86_64 && TRANSPARENT_HUGEPAGE 2500 2501menu "Power management and ACPI options" 2502 2503config ARCH_HIBERNATION_HEADER 2504 def_bool y 2505 depends on HIBERNATION 2506 2507source "kernel/power/Kconfig" 2508 2509source "drivers/acpi/Kconfig" 2510 2511source "drivers/sfi/Kconfig" 2512 2513config X86_APM_BOOT 2514 def_bool y 2515 depends on APM 2516 2517menuconfig APM 2518 tristate "APM (Advanced Power Management) BIOS support" 2519 depends on X86_32 && PM_SLEEP 2520 ---help--- 2521 APM is a BIOS specification for saving power using several different 2522 techniques. This is mostly useful for battery powered laptops with 2523 APM compliant BIOSes. If you say Y here, the system time will be 2524 reset after a RESUME operation, the /proc/apm device will provide 2525 battery status information, and user-space programs will receive 2526 notification of APM "events" (e.g. battery status change). 2527 2528 If you select "Y" here, you can disable actual use of the APM 2529 BIOS by passing the "apm=off" option to the kernel at boot time. 2530 2531 Note that the APM support is almost completely disabled for 2532 machines with more than one CPU. 2533 2534 In order to use APM, you will need supporting software. For location 2535 and more information, read <file:Documentation/power/apm-acpi.rst> 2536 and the Battery Powered Linux mini-HOWTO, available from 2537 <http://www.tldp.org/docs.html#howto>. 2538 2539 This driver does not spin down disk drives (see the hdparm(8) 2540 manpage ("man 8 hdparm") for that), and it doesn't turn off 2541 VESA-compliant "green" monitors. 2542 2543 This driver does not support the TI 4000M TravelMate and the ACER 2544 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2545 desktop machines also don't have compliant BIOSes, and this driver 2546 may cause those machines to panic during the boot phase. 2547 2548 Generally, if you don't have a battery in your machine, there isn't 2549 much point in using this driver and you should say N. If you get 2550 random kernel OOPSes or reboots that don't seem to be related to 2551 anything, try disabling/enabling this option (or disabling/enabling 2552 APM in your BIOS). 2553 2554 Some other things you should try when experiencing seemingly random, 2555 "weird" problems: 2556 2557 1) make sure that you have enough swap space and that it is 2558 enabled. 2559 2) pass the "no-hlt" option to the kernel 2560 3) switch on floating point emulation in the kernel and pass 2561 the "no387" option to the kernel 2562 4) pass the "floppy=nodma" option to the kernel 2563 5) pass the "mem=4M" option to the kernel (thereby disabling 2564 all but the first 4 MB of RAM) 2565 6) make sure that the CPU is not over clocked. 2566 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2567 8) disable the cache from your BIOS settings 2568 9) install a fan for the video card or exchange video RAM 2569 10) install a better fan for the CPU 2570 11) exchange RAM chips 2571 12) exchange the motherboard. 2572 2573 To compile this driver as a module, choose M here: the 2574 module will be called apm. 2575 2576if APM 2577 2578config APM_IGNORE_USER_SUSPEND 2579 bool "Ignore USER SUSPEND" 2580 ---help--- 2581 This option will ignore USER SUSPEND requests. On machines with a 2582 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2583 series notebooks, it is necessary to say Y because of a BIOS bug. 2584 2585config APM_DO_ENABLE 2586 bool "Enable PM at boot time" 2587 ---help--- 2588 Enable APM features at boot time. From page 36 of the APM BIOS 2589 specification: "When disabled, the APM BIOS does not automatically 2590 power manage devices, enter the Standby State, enter the Suspend 2591 State, or take power saving steps in response to CPU Idle calls." 2592 This driver will make CPU Idle calls when Linux is idle (unless this 2593 feature is turned off -- see "Do CPU IDLE calls", below). This 2594 should always save battery power, but more complicated APM features 2595 will be dependent on your BIOS implementation. You may need to turn 2596 this option off if your computer hangs at boot time when using APM 2597 support, or if it beeps continuously instead of suspending. Turn 2598 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2599 T400CDT. This is off by default since most machines do fine without 2600 this feature. 2601 2602config APM_CPU_IDLE 2603 depends on CPU_IDLE 2604 bool "Make CPU Idle calls when idle" 2605 ---help--- 2606 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2607 On some machines, this can activate improved power savings, such as 2608 a slowed CPU clock rate, when the machine is idle. These idle calls 2609 are made after the idle loop has run for some length of time (e.g., 2610 333 mS). On some machines, this will cause a hang at boot time or 2611 whenever the CPU becomes idle. (On machines with more than one CPU, 2612 this option does nothing.) 2613 2614config APM_DISPLAY_BLANK 2615 bool "Enable console blanking using APM" 2616 ---help--- 2617 Enable console blanking using the APM. Some laptops can use this to 2618 turn off the LCD backlight when the screen blanker of the Linux 2619 virtual console blanks the screen. Note that this is only used by 2620 the virtual console screen blanker, and won't turn off the backlight 2621 when using the X Window system. This also doesn't have anything to 2622 do with your VESA-compliant power-saving monitor. Further, this 2623 option doesn't work for all laptops -- it might not turn off your 2624 backlight at all, or it might print a lot of errors to the console, 2625 especially if you are using gpm. 2626 2627config APM_ALLOW_INTS 2628 bool "Allow interrupts during APM BIOS calls" 2629 ---help--- 2630 Normally we disable external interrupts while we are making calls to 2631 the APM BIOS as a measure to lessen the effects of a badly behaving 2632 BIOS implementation. The BIOS should reenable interrupts if it 2633 needs to. Unfortunately, some BIOSes do not -- especially those in 2634 many of the newer IBM Thinkpads. If you experience hangs when you 2635 suspend, try setting this to Y. Otherwise, say N. 2636 2637endif # APM 2638 2639source "drivers/cpufreq/Kconfig" 2640 2641source "drivers/cpuidle/Kconfig" 2642 2643source "drivers/idle/Kconfig" 2644 2645endmenu 2646 2647 2648menu "Bus options (PCI etc.)" 2649 2650choice 2651 prompt "PCI access mode" 2652 depends on X86_32 && PCI 2653 default PCI_GOANY 2654 ---help--- 2655 On PCI systems, the BIOS can be used to detect the PCI devices and 2656 determine their configuration. However, some old PCI motherboards 2657 have BIOS bugs and may crash if this is done. Also, some embedded 2658 PCI-based systems don't have any BIOS at all. Linux can also try to 2659 detect the PCI hardware directly without using the BIOS. 2660 2661 With this option, you can specify how Linux should detect the 2662 PCI devices. If you choose "BIOS", the BIOS will be used, 2663 if you choose "Direct", the BIOS won't be used, and if you 2664 choose "MMConfig", then PCI Express MMCONFIG will be used. 2665 If you choose "Any", the kernel will try MMCONFIG, then the 2666 direct access method and falls back to the BIOS if that doesn't 2667 work. If unsure, go with the default, which is "Any". 2668 2669config PCI_GOBIOS 2670 bool "BIOS" 2671 2672config PCI_GOMMCONFIG 2673 bool "MMConfig" 2674 2675config PCI_GODIRECT 2676 bool "Direct" 2677 2678config PCI_GOOLPC 2679 bool "OLPC XO-1" 2680 depends on OLPC 2681 2682config PCI_GOANY 2683 bool "Any" 2684 2685endchoice 2686 2687config PCI_BIOS 2688 def_bool y 2689 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2690 2691# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2692config PCI_DIRECT 2693 def_bool y 2694 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2695 2696config PCI_MMCONFIG 2697 bool "Support mmconfig PCI config space access" if X86_64 2698 default y 2699 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2700 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2701 2702config PCI_OLPC 2703 def_bool y 2704 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2705 2706config PCI_XEN 2707 def_bool y 2708 depends on PCI && XEN 2709 select SWIOTLB_XEN 2710 2711config MMCONF_FAM10H 2712 def_bool y 2713 depends on X86_64 && PCI_MMCONFIG && ACPI 2714 2715config PCI_CNB20LE_QUIRK 2716 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2717 depends on PCI 2718 help 2719 Read the PCI windows out of the CNB20LE host bridge. This allows 2720 PCI hotplug to work on systems with the CNB20LE chipset which do 2721 not have ACPI. 2722 2723 There's no public spec for this chipset, and this functionality 2724 is known to be incomplete. 2725 2726 You should say N unless you know you need this. 2727 2728config ISA_BUS 2729 bool "ISA bus support on modern systems" if EXPERT 2730 help 2731 Expose ISA bus device drivers and options available for selection and 2732 configuration. Enable this option if your target machine has an ISA 2733 bus. ISA is an older system, displaced by PCI and newer bus 2734 architectures -- if your target machine is modern, it probably does 2735 not have an ISA bus. 2736 2737 If unsure, say N. 2738 2739# x86_64 have no ISA slots, but can have ISA-style DMA. 2740config ISA_DMA_API 2741 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2742 default y 2743 help 2744 Enables ISA-style DMA support for devices requiring such controllers. 2745 If unsure, say Y. 2746 2747if X86_32 2748 2749config ISA 2750 bool "ISA support" 2751 ---help--- 2752 Find out whether you have ISA slots on your motherboard. ISA is the 2753 name of a bus system, i.e. the way the CPU talks to the other stuff 2754 inside your box. Other bus systems are PCI, EISA, MicroChannel 2755 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2756 newer boards don't support it. If you have ISA, say Y, otherwise N. 2757 2758config SCx200 2759 tristate "NatSemi SCx200 support" 2760 ---help--- 2761 This provides basic support for National Semiconductor's 2762 (now AMD's) Geode processors. The driver probes for the 2763 PCI-IDs of several on-chip devices, so its a good dependency 2764 for other scx200_* drivers. 2765 2766 If compiled as a module, the driver is named scx200. 2767 2768config SCx200HR_TIMER 2769 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2770 depends on SCx200 2771 default y 2772 ---help--- 2773 This driver provides a clocksource built upon the on-chip 2774 27MHz high-resolution timer. Its also a workaround for 2775 NSC Geode SC-1100's buggy TSC, which loses time when the 2776 processor goes idle (as is done by the scheduler). The 2777 other workaround is idle=poll boot option. 2778 2779config OLPC 2780 bool "One Laptop Per Child support" 2781 depends on !X86_PAE 2782 select GPIOLIB 2783 select OF 2784 select OF_PROMTREE 2785 select IRQ_DOMAIN 2786 select OLPC_EC 2787 ---help--- 2788 Add support for detecting the unique features of the OLPC 2789 XO hardware. 2790 2791config OLPC_XO1_PM 2792 bool "OLPC XO-1 Power Management" 2793 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2794 ---help--- 2795 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2796 2797config OLPC_XO1_RTC 2798 bool "OLPC XO-1 Real Time Clock" 2799 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2800 ---help--- 2801 Add support for the XO-1 real time clock, which can be used as a 2802 programmable wakeup source. 2803 2804config OLPC_XO1_SCI 2805 bool "OLPC XO-1 SCI extras" 2806 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2807 depends on INPUT=y 2808 select POWER_SUPPLY 2809 ---help--- 2810 Add support for SCI-based features of the OLPC XO-1 laptop: 2811 - EC-driven system wakeups 2812 - Power button 2813 - Ebook switch 2814 - Lid switch 2815 - AC adapter status updates 2816 - Battery status updates 2817 2818config OLPC_XO15_SCI 2819 bool "OLPC XO-1.5 SCI extras" 2820 depends on OLPC && ACPI 2821 select POWER_SUPPLY 2822 ---help--- 2823 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2824 - EC-driven system wakeups 2825 - AC adapter status updates 2826 - Battery status updates 2827 2828config ALIX 2829 bool "PCEngines ALIX System Support (LED setup)" 2830 select GPIOLIB 2831 ---help--- 2832 This option enables system support for the PCEngines ALIX. 2833 At present this just sets up LEDs for GPIO control on 2834 ALIX2/3/6 boards. However, other system specific setup should 2835 get added here. 2836 2837 Note: You must still enable the drivers for GPIO and LED support 2838 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2839 2840 Note: You have to set alix.force=1 for boards with Award BIOS. 2841 2842config NET5501 2843 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2844 select GPIOLIB 2845 ---help--- 2846 This option enables system support for the Soekris Engineering net5501. 2847 2848config GEOS 2849 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2850 select GPIOLIB 2851 depends on DMI 2852 ---help--- 2853 This option enables system support for the Traverse Technologies GEOS. 2854 2855config TS5500 2856 bool "Technologic Systems TS-5500 platform support" 2857 depends on MELAN 2858 select CHECK_SIGNATURE 2859 select NEW_LEDS 2860 select LEDS_CLASS 2861 ---help--- 2862 This option enables system support for the Technologic Systems TS-5500. 2863 2864endif # X86_32 2865 2866config AMD_NB 2867 def_bool y 2868 depends on CPU_SUP_AMD && PCI 2869 2870config X86_SYSFB 2871 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2872 help 2873 Firmwares often provide initial graphics framebuffers so the BIOS, 2874 bootloader or kernel can show basic video-output during boot for 2875 user-guidance and debugging. Historically, x86 used the VESA BIOS 2876 Extensions and EFI-framebuffers for this, which are mostly limited 2877 to x86. 2878 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2879 framebuffers so the new generic system-framebuffer drivers can be 2880 used on x86. If the framebuffer is not compatible with the generic 2881 modes, it is advertised as fallback platform framebuffer so legacy 2882 drivers like efifb, vesafb and uvesafb can pick it up. 2883 If this option is not selected, all system framebuffers are always 2884 marked as fallback platform framebuffers as usual. 2885 2886 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2887 not be able to pick up generic system framebuffers if this option 2888 is selected. You are highly encouraged to enable simplefb as 2889 replacement if you select this option. simplefb can correctly deal 2890 with generic system framebuffers. But you should still keep vesafb 2891 and others enabled as fallback if a system framebuffer is 2892 incompatible with simplefb. 2893 2894 If unsure, say Y. 2895 2896endmenu 2897 2898 2899menu "Binary Emulations" 2900 2901config IA32_EMULATION 2902 bool "IA32 Emulation" 2903 depends on X86_64 2904 select ARCH_WANT_OLD_COMPAT_IPC 2905 select BINFMT_ELF 2906 select COMPAT_BINFMT_ELF 2907 select COMPAT_OLD_SIGACTION 2908 ---help--- 2909 Include code to run legacy 32-bit programs under a 2910 64-bit kernel. You should likely turn this on, unless you're 2911 100% sure that you don't have any 32-bit programs left. 2912 2913config IA32_AOUT 2914 tristate "IA32 a.out support" 2915 depends on IA32_EMULATION 2916 depends on BROKEN 2917 ---help--- 2918 Support old a.out binaries in the 32bit emulation. 2919 2920config X86_X32 2921 bool "x32 ABI for 64-bit mode" 2922 depends on X86_64 2923 ---help--- 2924 Include code to run binaries for the x32 native 32-bit ABI 2925 for 64-bit processors. An x32 process gets access to the 2926 full 64-bit register file and wide data path while leaving 2927 pointers at 32 bits for smaller memory footprint. 2928 2929 You will need a recent binutils (2.22 or later) with 2930 elf32_x86_64 support enabled to compile a kernel with this 2931 option set. 2932 2933config COMPAT_32 2934 def_bool y 2935 depends on IA32_EMULATION || X86_32 2936 select HAVE_UID16 2937 select OLD_SIGSUSPEND3 2938 2939config COMPAT 2940 def_bool y 2941 depends on IA32_EMULATION || X86_X32 2942 2943if COMPAT 2944config COMPAT_FOR_U64_ALIGNMENT 2945 def_bool y 2946 2947config SYSVIPC_COMPAT 2948 def_bool y 2949 depends on SYSVIPC 2950endif 2951 2952endmenu 2953 2954 2955config HAVE_ATOMIC_IOMAP 2956 def_bool y 2957 depends on X86_32 2958 2959config X86_DEV_DMA_OPS 2960 bool 2961 2962source "drivers/firmware/Kconfig" 2963 2964source "arch/x86/kvm/Kconfig" 2965