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 34config FORCE_DYNAMIC_FTRACE 35 def_bool y 36 depends on X86_32 37 depends on FUNCTION_TRACER 38 select DYNAMIC_FTRACE 39 help 40 We keep the static function tracing (!DYNAMIC_FTRACE) around 41 in order to test the non static function tracing in the 42 generic code, as other architectures still use it. But we 43 only need to keep it around for x86_64. No need to keep it 44 for x86_32. For x86_32, force DYNAMIC_FTRACE. 45# 46# Arch settings 47# 48# ( Note that options that are marked 'if X86_64' could in principle be 49# ported to 32-bit as well. ) 50# 51config X86 52 def_bool y 53 # 54 # Note: keep this list sorted alphabetically 55 # 56 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 57 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 58 select ARCH_32BIT_OFF_T if X86_32 59 select ARCH_CLOCKSOURCE_INIT 60 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 61 select ARCH_HAS_DEBUG_VIRTUAL 62 select ARCH_HAS_DEVMEM_IS_ALLOWED 63 select ARCH_HAS_ELF_RANDOMIZE 64 select ARCH_HAS_FAST_MULTIPLIER 65 select ARCH_HAS_FILTER_PGPROT 66 select ARCH_HAS_FORTIFY_SOURCE 67 select ARCH_HAS_GCOV_PROFILE_ALL 68 select ARCH_HAS_KCOV if X86_64 69 select ARCH_HAS_MEM_ENCRYPT 70 select ARCH_HAS_MEMBARRIER_SYNC_CORE 71 select ARCH_HAS_PMEM_API if X86_64 72 select ARCH_HAS_PTE_DEVMAP if X86_64 73 select ARCH_HAS_PTE_SPECIAL 74 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 75 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 76 select ARCH_HAS_SET_MEMORY 77 select ARCH_HAS_SET_DIRECT_MAP 78 select ARCH_HAS_STRICT_KERNEL_RWX 79 select ARCH_HAS_STRICT_MODULE_RWX 80 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 81 select ARCH_HAS_SYSCALL_WRAPPER 82 select ARCH_HAS_UBSAN_SANITIZE_ALL 83 select ARCH_HAVE_NMI_SAFE_CMPXCHG 84 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 85 select ARCH_MIGHT_HAVE_PC_PARPORT 86 select ARCH_MIGHT_HAVE_PC_SERIO 87 select ARCH_STACKWALK 88 select ARCH_SUPPORTS_ACPI 89 select ARCH_SUPPORTS_ATOMIC_RMW 90 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 91 select ARCH_USE_BUILTIN_BSWAP 92 select ARCH_USE_QUEUED_RWLOCKS 93 select ARCH_USE_QUEUED_SPINLOCKS 94 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 95 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 96 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 97 select ARCH_WANT_HUGE_PMD_SHARE 98 select ARCH_WANTS_THP_SWAP if X86_64 99 select BUILDTIME_TABLE_SORT 100 select CLKEVT_I8253 101 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 102 select CLOCKSOURCE_WATCHDOG 103 select DCACHE_WORD_ACCESS 104 select EDAC_ATOMIC_SCRUB 105 select EDAC_SUPPORT 106 select GENERIC_CLOCKEVENTS 107 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 108 select GENERIC_CLOCKEVENTS_MIN_ADJUST 109 select GENERIC_CMOS_UPDATE 110 select GENERIC_CPU_AUTOPROBE 111 select GENERIC_CPU_VULNERABILITIES 112 select GENERIC_EARLY_IOREMAP 113 select GENERIC_FIND_FIRST_BIT 114 select GENERIC_IOMAP 115 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 116 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 117 select GENERIC_IRQ_MIGRATION if SMP 118 select GENERIC_IRQ_PROBE 119 select GENERIC_IRQ_RESERVATION_MODE 120 select GENERIC_IRQ_SHOW 121 select GENERIC_PENDING_IRQ if SMP 122 select GENERIC_PTDUMP 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 GENERIC_VDSO_TIME_NS 129 select GUP_GET_PTE_LOW_HIGH if X86_PAE 130 select HARDIRQS_SW_RESEND 131 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 132 select HAVE_ACPI_APEI if ACPI 133 select HAVE_ACPI_APEI_NMI if ACPI 134 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 135 select HAVE_ARCH_AUDITSYSCALL 136 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 137 select HAVE_ARCH_JUMP_LABEL 138 select HAVE_ARCH_JUMP_LABEL_RELATIVE 139 select HAVE_ARCH_KASAN if X86_64 140 select HAVE_ARCH_KASAN_VMALLOC if X86_64 141 select HAVE_ARCH_KGDB 142 select HAVE_ARCH_MMAP_RND_BITS if MMU 143 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 144 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 145 select HAVE_ARCH_PREL32_RELOCATIONS 146 select HAVE_ARCH_SECCOMP_FILTER 147 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 148 select HAVE_ARCH_STACKLEAK 149 select HAVE_ARCH_TRACEHOOK 150 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 151 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 152 select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD 153 select HAVE_ARCH_VMAP_STACK if X86_64 154 select HAVE_ARCH_WITHIN_STACK_FRAMES 155 select HAVE_ASM_MODVERSIONS 156 select HAVE_CMPXCHG_DOUBLE 157 select HAVE_CMPXCHG_LOCAL 158 select HAVE_CONTEXT_TRACKING if X86_64 159 select HAVE_COPY_THREAD_TLS 160 select HAVE_C_RECORDMCOUNT 161 select HAVE_DEBUG_KMEMLEAK 162 select HAVE_DMA_CONTIGUOUS 163 select HAVE_DYNAMIC_FTRACE 164 select HAVE_DYNAMIC_FTRACE_WITH_REGS 165 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 166 select HAVE_EBPF_JIT 167 select HAVE_EFFICIENT_UNALIGNED_ACCESS 168 select HAVE_EISA 169 select HAVE_EXIT_THREAD 170 select HAVE_FAST_GUP 171 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 172 select HAVE_FTRACE_MCOUNT_RECORD 173 select HAVE_FUNCTION_GRAPH_TRACER 174 select HAVE_FUNCTION_TRACER 175 select HAVE_GCC_PLUGINS 176 select HAVE_HW_BREAKPOINT 177 select HAVE_IDE 178 select HAVE_IOREMAP_PROT 179 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 180 select HAVE_IRQ_TIME_ACCOUNTING 181 select HAVE_KERNEL_BZIP2 182 select HAVE_KERNEL_GZIP 183 select HAVE_KERNEL_LZ4 184 select HAVE_KERNEL_LZMA 185 select HAVE_KERNEL_LZO 186 select HAVE_KERNEL_XZ 187 select HAVE_KPROBES 188 select HAVE_KPROBES_ON_FTRACE 189 select HAVE_FUNCTION_ERROR_INJECTION 190 select HAVE_KRETPROBES 191 select HAVE_KVM 192 select HAVE_LIVEPATCH if X86_64 193 select HAVE_MEMBLOCK_NODE_MAP 194 select HAVE_MIXED_BREAKPOINTS_REGS 195 select HAVE_MOD_ARCH_SPECIFIC 196 select HAVE_MOVE_PMD 197 select HAVE_NMI 198 select HAVE_OPROFILE 199 select HAVE_OPTPROBES 200 select HAVE_PCSPKR_PLATFORM 201 select HAVE_PERF_EVENTS 202 select HAVE_PERF_EVENTS_NMI 203 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 204 select HAVE_PCI 205 select HAVE_PERF_REGS 206 select HAVE_PERF_USER_STACK_DUMP 207 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 208 select HAVE_REGS_AND_STACK_ACCESS_API 209 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 210 select HAVE_FUNCTION_ARG_ACCESS_API 211 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 212 select HAVE_STACK_VALIDATION if X86_64 213 select HAVE_RSEQ 214 select HAVE_SYSCALL_TRACEPOINTS 215 select HAVE_UNSTABLE_SCHED_CLOCK 216 select HAVE_USER_RETURN_NOTIFIER 217 select HAVE_GENERIC_VDSO 218 select HOTPLUG_SMT if SMP 219 select IRQ_FORCED_THREADING 220 select NEED_SG_DMA_LENGTH 221 select PCI_DOMAINS if PCI 222 select PCI_LOCKLESS_CONFIG if PCI 223 select PERF_EVENTS 224 select RTC_LIB 225 select RTC_MC146818_LIB 226 select SPARSE_IRQ 227 select SRCU 228 select SYSCTL_EXCEPTION_TRACE 229 select THREAD_INFO_IN_TASK 230 select USER_STACKTRACE_SUPPORT 231 select VIRT_TO_BUS 232 select X86_FEATURE_NAMES if PROC_FS 233 select PROC_PID_ARCH_STATUS if PROC_FS 234 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 235 236config INSTRUCTION_DECODER 237 def_bool y 238 depends on KPROBES || PERF_EVENTS || UPROBES 239 240config OUTPUT_FORMAT 241 string 242 default "elf32-i386" if X86_32 243 default "elf64-x86-64" if X86_64 244 245config LOCKDEP_SUPPORT 246 def_bool y 247 248config STACKTRACE_SUPPORT 249 def_bool y 250 251config MMU 252 def_bool y 253 254config ARCH_MMAP_RND_BITS_MIN 255 default 28 if 64BIT 256 default 8 257 258config ARCH_MMAP_RND_BITS_MAX 259 default 32 if 64BIT 260 default 16 261 262config ARCH_MMAP_RND_COMPAT_BITS_MIN 263 default 8 264 265config ARCH_MMAP_RND_COMPAT_BITS_MAX 266 default 16 267 268config SBUS 269 bool 270 271config GENERIC_ISA_DMA 272 def_bool y 273 depends on ISA_DMA_API 274 275config GENERIC_BUG 276 def_bool y 277 depends on BUG 278 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 279 280config GENERIC_BUG_RELATIVE_POINTERS 281 bool 282 283config ARCH_MAY_HAVE_PC_FDC 284 def_bool y 285 depends on ISA_DMA_API 286 287config GENERIC_CALIBRATE_DELAY 288 def_bool y 289 290config ARCH_HAS_CPU_RELAX 291 def_bool y 292 293config ARCH_HAS_CACHE_LINE_SIZE 294 def_bool y 295 296config ARCH_HAS_FILTER_PGPROT 297 def_bool y 298 299config HAVE_SETUP_PER_CPU_AREA 300 def_bool y 301 302config NEED_PER_CPU_EMBED_FIRST_CHUNK 303 def_bool y 304 305config NEED_PER_CPU_PAGE_FIRST_CHUNK 306 def_bool y 307 308config ARCH_HIBERNATION_POSSIBLE 309 def_bool y 310 311config ARCH_SUSPEND_POSSIBLE 312 def_bool y 313 314config ARCH_WANT_GENERAL_HUGETLB 315 def_bool y 316 317config ZONE_DMA32 318 def_bool y if X86_64 319 320config AUDIT_ARCH 321 def_bool y if X86_64 322 323config ARCH_SUPPORTS_DEBUG_PAGEALLOC 324 def_bool y 325 326config KASAN_SHADOW_OFFSET 327 hex 328 depends on KASAN 329 default 0xdffffc0000000000 330 331config HAVE_INTEL_TXT 332 def_bool y 333 depends on INTEL_IOMMU && ACPI 334 335config X86_32_SMP 336 def_bool y 337 depends on X86_32 && SMP 338 339config X86_64_SMP 340 def_bool y 341 depends on X86_64 && SMP 342 343config X86_32_LAZY_GS 344 def_bool y 345 depends on X86_32 && !STACKPROTECTOR 346 347config ARCH_SUPPORTS_UPROBES 348 def_bool y 349 350config FIX_EARLYCON_MEM 351 def_bool y 352 353config DYNAMIC_PHYSICAL_MASK 354 bool 355 356config PGTABLE_LEVELS 357 int 358 default 5 if X86_5LEVEL 359 default 4 if X86_64 360 default 3 if X86_PAE 361 default 2 362 363config CC_HAS_SANE_STACKPROTECTOR 364 bool 365 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 366 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 367 help 368 We have to make sure stack protector is unconditionally disabled if 369 the compiler produces broken code. 370 371menu "Processor type and features" 372 373config ZONE_DMA 374 bool "DMA memory allocation support" if EXPERT 375 default y 376 help 377 DMA memory allocation support allows devices with less than 32-bit 378 addressing to allocate within the first 16MB of address space. 379 Disable if no such devices will be used. 380 381 If unsure, say Y. 382 383config SMP 384 bool "Symmetric multi-processing support" 385 ---help--- 386 This enables support for systems with more than one CPU. If you have 387 a system with only one CPU, say N. If you have a system with more 388 than one CPU, say Y. 389 390 If you say N here, the kernel will run on uni- and multiprocessor 391 machines, but will use only one CPU of a multiprocessor machine. If 392 you say Y here, the kernel will run on many, but not all, 393 uniprocessor machines. On a uniprocessor machine, the kernel 394 will run faster if you say N here. 395 396 Note that if you say Y here and choose architecture "586" or 397 "Pentium" under "Processor family", the kernel will not work on 486 398 architectures. Similarly, multiprocessor kernels for the "PPro" 399 architecture may not work on all Pentium based boards. 400 401 People using multiprocessor machines who say Y here should also say 402 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 403 Management" code will be disabled if you say Y here. 404 405 See also <file:Documentation/x86/i386/IO-APIC.rst>, 406 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 407 <http://www.tldp.org/docs.html#howto>. 408 409 If you don't know what to do here, say N. 410 411config X86_FEATURE_NAMES 412 bool "Processor feature human-readable names" if EMBEDDED 413 default y 414 ---help--- 415 This option compiles in a table of x86 feature bits and corresponding 416 names. This is required to support /proc/cpuinfo and a few kernel 417 messages. You can disable this to save space, at the expense of 418 making those few kernel messages show numeric feature bits instead. 419 420 If in doubt, say Y. 421 422config X86_X2APIC 423 bool "Support x2apic" 424 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 425 ---help--- 426 This enables x2apic support on CPUs that have this feature. 427 428 This allows 32-bit apic IDs (so it can support very large systems), 429 and accesses the local apic via MSRs not via mmio. 430 431 If you don't know what to do here, say N. 432 433config X86_MPPARSE 434 bool "Enable MPS table" if ACPI || SFI 435 default y 436 depends on X86_LOCAL_APIC 437 ---help--- 438 For old smp systems that do not have proper acpi support. Newer systems 439 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 440 441config GOLDFISH 442 def_bool y 443 depends on X86_GOLDFISH 444 445config RETPOLINE 446 bool "Avoid speculative indirect branches in kernel" 447 default y 448 select STACK_VALIDATION if HAVE_STACK_VALIDATION 449 help 450 Compile kernel with the retpoline compiler options to guard against 451 kernel-to-user data leaks by avoiding speculative indirect 452 branches. Requires a compiler with -mindirect-branch=thunk-extern 453 support for full protection. The kernel may run slower. 454 455config X86_CPU_RESCTRL 456 bool "x86 CPU resource control support" 457 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 458 select KERNFS 459 select PROC_CPU_RESCTRL if PROC_FS 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 mechanism, 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 NUMA_KEEP_MEMINFO if NUMA 1665 select LIBNVDIMM 1666 help 1667 Treat memory marked using the non-standard e820 type of 12 as used 1668 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1669 The kernel will offer these regions to the 'pmem' driver so 1670 they can be used for persistent storage. 1671 1672 Say Y if unsure. 1673 1674config HIGHPTE 1675 bool "Allocate 3rd-level pagetables from highmem" 1676 depends on HIGHMEM 1677 ---help--- 1678 The VM uses one page table entry for each page of physical memory. 1679 For systems with a lot of RAM, this can be wasteful of precious 1680 low memory. Setting this option will put user-space page table 1681 entries in high memory. 1682 1683config X86_CHECK_BIOS_CORRUPTION 1684 bool "Check for low memory corruption" 1685 ---help--- 1686 Periodically check for memory corruption in low memory, which 1687 is suspected to be caused by BIOS. Even when enabled in the 1688 configuration, it is disabled at runtime. Enable it by 1689 setting "memory_corruption_check=1" on the kernel command 1690 line. By default it scans the low 64k of memory every 60 1691 seconds; see the memory_corruption_check_size and 1692 memory_corruption_check_period parameters in 1693 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1694 1695 When enabled with the default parameters, this option has 1696 almost no overhead, as it reserves a relatively small amount 1697 of memory and scans it infrequently. It both detects corruption 1698 and prevents it from affecting the running system. 1699 1700 It is, however, intended as a diagnostic tool; if repeatable 1701 BIOS-originated corruption always affects the same memory, 1702 you can use memmap= to prevent the kernel from using that 1703 memory. 1704 1705config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1706 bool "Set the default setting of memory_corruption_check" 1707 depends on X86_CHECK_BIOS_CORRUPTION 1708 default y 1709 ---help--- 1710 Set whether the default state of memory_corruption_check is 1711 on or off. 1712 1713config X86_RESERVE_LOW 1714 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1715 default 64 1716 range 4 640 1717 ---help--- 1718 Specify the amount of low memory to reserve for the BIOS. 1719 1720 The first page contains BIOS data structures that the kernel 1721 must not use, so that page must always be reserved. 1722 1723 By default we reserve the first 64K of physical RAM, as a 1724 number of BIOSes are known to corrupt that memory range 1725 during events such as suspend/resume or monitor cable 1726 insertion, so it must not be used by the kernel. 1727 1728 You can set this to 4 if you are absolutely sure that you 1729 trust the BIOS to get all its memory reservations and usages 1730 right. If you know your BIOS have problems beyond the 1731 default 64K area, you can set this to 640 to avoid using the 1732 entire low memory range. 1733 1734 If you have doubts about the BIOS (e.g. suspend/resume does 1735 not work or there's kernel crashes after certain hardware 1736 hotplug events) then you might want to enable 1737 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1738 typical corruption patterns. 1739 1740 Leave this to the default value of 64 if you are unsure. 1741 1742config MATH_EMULATION 1743 bool 1744 depends on MODIFY_LDT_SYSCALL 1745 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1746 ---help--- 1747 Linux can emulate a math coprocessor (used for floating point 1748 operations) if you don't have one. 486DX and Pentium processors have 1749 a math coprocessor built in, 486SX and 386 do not, unless you added 1750 a 487DX or 387, respectively. (The messages during boot time can 1751 give you some hints here ["man dmesg"].) Everyone needs either a 1752 coprocessor or this emulation. 1753 1754 If you don't have a math coprocessor, you need to say Y here; if you 1755 say Y here even though you have a coprocessor, the coprocessor will 1756 be used nevertheless. (This behavior can be changed with the kernel 1757 command line option "no387", which comes handy if your coprocessor 1758 is broken. Try "man bootparam" or see the documentation of your boot 1759 loader (lilo or loadlin) about how to pass options to the kernel at 1760 boot time.) This means that it is a good idea to say Y here if you 1761 intend to use this kernel on different machines. 1762 1763 More information about the internals of the Linux math coprocessor 1764 emulation can be found in <file:arch/x86/math-emu/README>. 1765 1766 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1767 kernel, it won't hurt. 1768 1769config MTRR 1770 def_bool y 1771 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1772 ---help--- 1773 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1774 the Memory Type Range Registers (MTRRs) may be used to control 1775 processor access to memory ranges. This is most useful if you have 1776 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1777 allows bus write transfers to be combined into a larger transfer 1778 before bursting over the PCI/AGP bus. This can increase performance 1779 of image write operations 2.5 times or more. Saying Y here creates a 1780 /proc/mtrr file which may be used to manipulate your processor's 1781 MTRRs. Typically the X server should use this. 1782 1783 This code has a reasonably generic interface so that similar 1784 control registers on other processors can be easily supported 1785 as well: 1786 1787 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1788 Registers (ARRs) which provide a similar functionality to MTRRs. For 1789 these, the ARRs are used to emulate the MTRRs. 1790 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1791 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1792 write-combining. All of these processors are supported by this code 1793 and it makes sense to say Y here if you have one of them. 1794 1795 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1796 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1797 can lead to all sorts of problems, so it's good to say Y here. 1798 1799 You can safely say Y even if your machine doesn't have MTRRs, you'll 1800 just add about 9 KB to your kernel. 1801 1802 See <file:Documentation/x86/mtrr.rst> for more information. 1803 1804config MTRR_SANITIZER 1805 def_bool y 1806 prompt "MTRR cleanup support" 1807 depends on MTRR 1808 ---help--- 1809 Convert MTRR layout from continuous to discrete, so X drivers can 1810 add writeback entries. 1811 1812 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1813 The largest mtrr entry size for a continuous block can be set with 1814 mtrr_chunk_size. 1815 1816 If unsure, say Y. 1817 1818config MTRR_SANITIZER_ENABLE_DEFAULT 1819 int "MTRR cleanup enable value (0-1)" 1820 range 0 1 1821 default "0" 1822 depends on MTRR_SANITIZER 1823 ---help--- 1824 Enable mtrr cleanup default value 1825 1826config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1827 int "MTRR cleanup spare reg num (0-7)" 1828 range 0 7 1829 default "1" 1830 depends on MTRR_SANITIZER 1831 ---help--- 1832 mtrr cleanup spare entries default, it can be changed via 1833 mtrr_spare_reg_nr=N on the kernel command line. 1834 1835config X86_PAT 1836 def_bool y 1837 prompt "x86 PAT support" if EXPERT 1838 depends on MTRR 1839 ---help--- 1840 Use PAT attributes to setup page level cache control. 1841 1842 PATs are the modern equivalents of MTRRs and are much more 1843 flexible than MTRRs. 1844 1845 Say N here if you see bootup problems (boot crash, boot hang, 1846 spontaneous reboots) or a non-working video driver. 1847 1848 If unsure, say Y. 1849 1850config ARCH_USES_PG_UNCACHED 1851 def_bool y 1852 depends on X86_PAT 1853 1854config ARCH_RANDOM 1855 def_bool y 1856 prompt "x86 architectural random number generator" if EXPERT 1857 ---help--- 1858 Enable the x86 architectural RDRAND instruction 1859 (Intel Bull Mountain technology) to generate random numbers. 1860 If supported, this is a high bandwidth, cryptographically 1861 secure hardware random number generator. 1862 1863config X86_SMAP 1864 def_bool y 1865 prompt "Supervisor Mode Access Prevention" if EXPERT 1866 ---help--- 1867 Supervisor Mode Access Prevention (SMAP) is a security 1868 feature in newer Intel processors. There is a small 1869 performance cost if this enabled and turned on; there is 1870 also a small increase in the kernel size if this is enabled. 1871 1872 If unsure, say Y. 1873 1874config X86_UMIP 1875 def_bool y 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_MEMORY_PROTECTION_KEYS 1890 prompt "Intel Memory Protection Keys" 1891 def_bool y 1892 # Note: only available in 64-bit mode 1893 depends on CPU_SUP_INTEL && X86_64 1894 select ARCH_USES_HIGH_VMA_FLAGS 1895 select ARCH_HAS_PKEYS 1896 ---help--- 1897 Memory Protection Keys provides a mechanism for enforcing 1898 page-based protections, but without requiring modification of the 1899 page tables when an application changes protection domains. 1900 1901 For details, see Documentation/core-api/protection-keys.rst 1902 1903 If unsure, say y. 1904 1905choice 1906 prompt "TSX enable mode" 1907 depends on CPU_SUP_INTEL 1908 default X86_INTEL_TSX_MODE_OFF 1909 help 1910 Intel's TSX (Transactional Synchronization Extensions) feature 1911 allows to optimize locking protocols through lock elision which 1912 can lead to a noticeable performance boost. 1913 1914 On the other hand it has been shown that TSX can be exploited 1915 to form side channel attacks (e.g. TAA) and chances are there 1916 will be more of those attacks discovered in the future. 1917 1918 Therefore TSX is not enabled by default (aka tsx=off). An admin 1919 might override this decision by tsx=on the command line parameter. 1920 Even with TSX enabled, the kernel will attempt to enable the best 1921 possible TAA mitigation setting depending on the microcode available 1922 for the particular machine. 1923 1924 This option allows to set the default tsx mode between tsx=on, =off 1925 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1926 details. 1927 1928 Say off if not sure, auto if TSX is in use but it should be used on safe 1929 platforms or on if TSX is in use and the security aspect of tsx is not 1930 relevant. 1931 1932config X86_INTEL_TSX_MODE_OFF 1933 bool "off" 1934 help 1935 TSX is disabled if possible - equals to tsx=off command line parameter. 1936 1937config X86_INTEL_TSX_MODE_ON 1938 bool "on" 1939 help 1940 TSX is always enabled on TSX capable HW - equals the tsx=on command 1941 line parameter. 1942 1943config X86_INTEL_TSX_MODE_AUTO 1944 bool "auto" 1945 help 1946 TSX is enabled on TSX capable HW that is believed to be safe against 1947 side channel attacks- equals the tsx=auto command line parameter. 1948endchoice 1949 1950config EFI 1951 bool "EFI runtime service support" 1952 depends on ACPI 1953 select UCS2_STRING 1954 select EFI_RUNTIME_WRAPPERS 1955 ---help--- 1956 This enables the kernel to use EFI runtime services that are 1957 available (such as the EFI variable services). 1958 1959 This option is only useful on systems that have EFI firmware. 1960 In addition, you should use the latest ELILO loader available 1961 at <http://elilo.sourceforge.net> in order to take advantage 1962 of EFI runtime services. However, even with this option, the 1963 resultant kernel should continue to boot on existing non-EFI 1964 platforms. 1965 1966config EFI_STUB 1967 bool "EFI stub support" 1968 depends on EFI && !X86_USE_3DNOW 1969 depends on $(cc-option,-mabi=ms) || X86_32 1970 select RELOCATABLE 1971 ---help--- 1972 This kernel feature allows a bzImage to be loaded directly 1973 by EFI firmware without the use of a bootloader. 1974 1975 See Documentation/admin-guide/efi-stub.rst for more information. 1976 1977config EFI_MIXED 1978 bool "EFI mixed-mode support" 1979 depends on EFI_STUB && X86_64 1980 ---help--- 1981 Enabling this feature allows a 64-bit kernel to be booted 1982 on a 32-bit firmware, provided that your CPU supports 64-bit 1983 mode. 1984 1985 Note that it is not possible to boot a mixed-mode enabled 1986 kernel via the EFI boot stub - a bootloader that supports 1987 the EFI handover protocol must be used. 1988 1989 If unsure, say N. 1990 1991config SECCOMP 1992 def_bool y 1993 prompt "Enable seccomp to safely compute untrusted bytecode" 1994 ---help--- 1995 This kernel feature is useful for number crunching applications 1996 that may need to compute untrusted bytecode during their 1997 execution. By using pipes or other transports made available to 1998 the process as file descriptors supporting the read/write 1999 syscalls, it's possible to isolate those applications in 2000 their own address space using seccomp. Once seccomp is 2001 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 2002 and the task is only allowed to execute a few safe syscalls 2003 defined by each seccomp mode. 2004 2005 If unsure, say Y. Only embedded should say N here. 2006 2007source "kernel/Kconfig.hz" 2008 2009config KEXEC 2010 bool "kexec system call" 2011 select KEXEC_CORE 2012 ---help--- 2013 kexec is a system call that implements the ability to shutdown your 2014 current kernel, and to start another kernel. It is like a reboot 2015 but it is independent of the system firmware. And like a reboot 2016 you can start any kernel with it, not just Linux. 2017 2018 The name comes from the similarity to the exec system call. 2019 2020 It is an ongoing process to be certain the hardware in a machine 2021 is properly shutdown, so do not be surprised if this code does not 2022 initially work for you. As of this writing the exact hardware 2023 interface is strongly in flux, so no good recommendation can be 2024 made. 2025 2026config KEXEC_FILE 2027 bool "kexec file based system call" 2028 select KEXEC_CORE 2029 select BUILD_BIN2C 2030 depends on X86_64 2031 depends on CRYPTO=y 2032 depends on CRYPTO_SHA256=y 2033 ---help--- 2034 This is new version of kexec system call. This system call is 2035 file based and takes file descriptors as system call argument 2036 for kernel and initramfs as opposed to list of segments as 2037 accepted by previous system call. 2038 2039config ARCH_HAS_KEXEC_PURGATORY 2040 def_bool KEXEC_FILE 2041 2042config KEXEC_SIG 2043 bool "Verify kernel signature during kexec_file_load() syscall" 2044 depends on KEXEC_FILE 2045 ---help--- 2046 2047 This option makes the kexec_file_load() syscall check for a valid 2048 signature of the kernel image. The image can still be loaded without 2049 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2050 there's a signature that we can check, then it must be valid. 2051 2052 In addition to this option, you need to enable signature 2053 verification for the corresponding kernel image type being 2054 loaded in order for this to work. 2055 2056config KEXEC_SIG_FORCE 2057 bool "Require a valid signature in kexec_file_load() syscall" 2058 depends on KEXEC_SIG 2059 ---help--- 2060 This option makes kernel signature verification mandatory for 2061 the kexec_file_load() syscall. 2062 2063config KEXEC_BZIMAGE_VERIFY_SIG 2064 bool "Enable bzImage signature verification support" 2065 depends on KEXEC_SIG 2066 depends on SIGNED_PE_FILE_VERIFICATION 2067 select SYSTEM_TRUSTED_KEYRING 2068 ---help--- 2069 Enable bzImage signature verification support. 2070 2071config CRASH_DUMP 2072 bool "kernel crash dumps" 2073 depends on X86_64 || (X86_32 && HIGHMEM) 2074 ---help--- 2075 Generate crash dump after being started by kexec. 2076 This should be normally only set in special crash dump kernels 2077 which are loaded in the main kernel with kexec-tools into 2078 a specially reserved region and then later executed after 2079 a crash by kdump/kexec. The crash dump kernel must be compiled 2080 to a memory address not used by the main kernel or BIOS using 2081 PHYSICAL_START, or it must be built as a relocatable image 2082 (CONFIG_RELOCATABLE=y). 2083 For more details see Documentation/admin-guide/kdump/kdump.rst 2084 2085config KEXEC_JUMP 2086 bool "kexec jump" 2087 depends on KEXEC && HIBERNATION 2088 ---help--- 2089 Jump between original kernel and kexeced kernel and invoke 2090 code in physical address mode via KEXEC 2091 2092config PHYSICAL_START 2093 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2094 default "0x1000000" 2095 ---help--- 2096 This gives the physical address where the kernel is loaded. 2097 2098 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2099 bzImage will decompress itself to above physical address and 2100 run from there. Otherwise, bzImage will run from the address where 2101 it has been loaded by the boot loader and will ignore above physical 2102 address. 2103 2104 In normal kdump cases one does not have to set/change this option 2105 as now bzImage can be compiled as a completely relocatable image 2106 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2107 address. This option is mainly useful for the folks who don't want 2108 to use a bzImage for capturing the crash dump and want to use a 2109 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2110 to be specifically compiled to run from a specific memory area 2111 (normally a reserved region) and this option comes handy. 2112 2113 So if you are using bzImage for capturing the crash dump, 2114 leave the value here unchanged to 0x1000000 and set 2115 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2116 for capturing the crash dump change this value to start of 2117 the reserved region. In other words, it can be set based on 2118 the "X" value as specified in the "crashkernel=YM@XM" 2119 command line boot parameter passed to the panic-ed 2120 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2121 for more details about crash dumps. 2122 2123 Usage of bzImage for capturing the crash dump is recommended as 2124 one does not have to build two kernels. Same kernel can be used 2125 as production kernel and capture kernel. Above option should have 2126 gone away after relocatable bzImage support is introduced. But it 2127 is present because there are users out there who continue to use 2128 vmlinux for dump capture. This option should go away down the 2129 line. 2130 2131 Don't change this unless you know what you are doing. 2132 2133config RELOCATABLE 2134 bool "Build a relocatable kernel" 2135 default y 2136 ---help--- 2137 This builds a kernel image that retains relocation information 2138 so it can be loaded someplace besides the default 1MB. 2139 The relocations tend to make the kernel binary about 10% larger, 2140 but are discarded at runtime. 2141 2142 One use is for the kexec on panic case where the recovery kernel 2143 must live at a different physical address than the primary 2144 kernel. 2145 2146 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2147 it has been loaded at and the compile time physical address 2148 (CONFIG_PHYSICAL_START) is used as the minimum location. 2149 2150config RANDOMIZE_BASE 2151 bool "Randomize the address of the kernel image (KASLR)" 2152 depends on RELOCATABLE 2153 default y 2154 ---help--- 2155 In support of Kernel Address Space Layout Randomization (KASLR), 2156 this randomizes the physical address at which the kernel image 2157 is decompressed and the virtual address where the kernel 2158 image is mapped, as a security feature that deters exploit 2159 attempts relying on knowledge of the location of kernel 2160 code internals. 2161 2162 On 64-bit, the kernel physical and virtual addresses are 2163 randomized separately. The physical address will be anywhere 2164 between 16MB and the top of physical memory (up to 64TB). The 2165 virtual address will be randomized from 16MB up to 1GB (9 bits 2166 of entropy). Note that this also reduces the memory space 2167 available to kernel modules from 1.5GB to 1GB. 2168 2169 On 32-bit, the kernel physical and virtual addresses are 2170 randomized together. They will be randomized from 16MB up to 2171 512MB (8 bits of entropy). 2172 2173 Entropy is generated using the RDRAND instruction if it is 2174 supported. If RDTSC is supported, its value is mixed into 2175 the entropy pool as well. If neither RDRAND nor RDTSC are 2176 supported, then entropy is read from the i8254 timer. The 2177 usable entropy is limited by the kernel being built using 2178 2GB addressing, and that PHYSICAL_ALIGN must be at a 2179 minimum of 2MB. As a result, only 10 bits of entropy are 2180 theoretically possible, but the implementations are further 2181 limited due to memory layouts. 2182 2183 If unsure, say Y. 2184 2185# Relocation on x86 needs some additional build support 2186config X86_NEED_RELOCS 2187 def_bool y 2188 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2189 2190config PHYSICAL_ALIGN 2191 hex "Alignment value to which kernel should be aligned" 2192 default "0x200000" 2193 range 0x2000 0x1000000 if X86_32 2194 range 0x200000 0x1000000 if X86_64 2195 ---help--- 2196 This value puts the alignment restrictions on physical address 2197 where kernel is loaded and run from. Kernel is compiled for an 2198 address which meets above alignment restriction. 2199 2200 If bootloader loads the kernel at a non-aligned address and 2201 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2202 address aligned to above value and run from there. 2203 2204 If bootloader loads the kernel at a non-aligned address and 2205 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2206 load address and decompress itself to the address it has been 2207 compiled for and run from there. The address for which kernel is 2208 compiled already meets above alignment restrictions. Hence the 2209 end result is that kernel runs from a physical address meeting 2210 above alignment restrictions. 2211 2212 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2213 this value must be a multiple of 0x200000. 2214 2215 Don't change this unless you know what you are doing. 2216 2217config DYNAMIC_MEMORY_LAYOUT 2218 bool 2219 ---help--- 2220 This option makes base addresses of vmalloc and vmemmap as well as 2221 __PAGE_OFFSET movable during boot. 2222 2223config RANDOMIZE_MEMORY 2224 bool "Randomize the kernel memory sections" 2225 depends on X86_64 2226 depends on RANDOMIZE_BASE 2227 select DYNAMIC_MEMORY_LAYOUT 2228 default RANDOMIZE_BASE 2229 ---help--- 2230 Randomizes the base virtual address of kernel memory sections 2231 (physical memory mapping, vmalloc & vmemmap). This security feature 2232 makes exploits relying on predictable memory locations less reliable. 2233 2234 The order of allocations remains unchanged. Entropy is generated in 2235 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2236 configuration have in average 30,000 different possible virtual 2237 addresses for each memory section. 2238 2239 If unsure, say Y. 2240 2241config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2242 hex "Physical memory mapping padding" if EXPERT 2243 depends on RANDOMIZE_MEMORY 2244 default "0xa" if MEMORY_HOTPLUG 2245 default "0x0" 2246 range 0x1 0x40 if MEMORY_HOTPLUG 2247 range 0x0 0x40 2248 ---help--- 2249 Define the padding in terabytes added to the existing physical 2250 memory size during kernel memory randomization. It is useful 2251 for memory hotplug support but reduces the entropy available for 2252 address randomization. 2253 2254 If unsure, leave at the default value. 2255 2256config HOTPLUG_CPU 2257 def_bool y 2258 depends on SMP 2259 2260config BOOTPARAM_HOTPLUG_CPU0 2261 bool "Set default setting of cpu0_hotpluggable" 2262 depends on HOTPLUG_CPU 2263 ---help--- 2264 Set whether default state of cpu0_hotpluggable is on or off. 2265 2266 Say Y here to enable CPU0 hotplug by default. If this switch 2267 is turned on, there is no need to give cpu0_hotplug kernel 2268 parameter and the CPU0 hotplug feature is enabled by default. 2269 2270 Please note: there are two known CPU0 dependencies if you want 2271 to enable the CPU0 hotplug feature either by this switch or by 2272 cpu0_hotplug kernel parameter. 2273 2274 First, resume from hibernate or suspend always starts from CPU0. 2275 So hibernate and suspend are prevented if CPU0 is offline. 2276 2277 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2278 offline if any interrupt can not migrate out of CPU0. There may 2279 be other CPU0 dependencies. 2280 2281 Please make sure the dependencies are under your control before 2282 you enable this feature. 2283 2284 Say N if you don't want to enable CPU0 hotplug feature by default. 2285 You still can enable the CPU0 hotplug feature at boot by kernel 2286 parameter cpu0_hotplug. 2287 2288config DEBUG_HOTPLUG_CPU0 2289 def_bool n 2290 prompt "Debug CPU0 hotplug" 2291 depends on HOTPLUG_CPU 2292 ---help--- 2293 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2294 soon as possible and boots up userspace with CPU0 offlined. User 2295 can online CPU0 back after boot time. 2296 2297 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2298 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2299 compilation or giving cpu0_hotplug kernel parameter at boot. 2300 2301 If unsure, say N. 2302 2303config COMPAT_VDSO 2304 def_bool n 2305 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2306 depends on COMPAT_32 2307 ---help--- 2308 Certain buggy versions of glibc will crash if they are 2309 presented with a 32-bit vDSO that is not mapped at the address 2310 indicated in its segment table. 2311 2312 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2313 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2314 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2315 the only released version with the bug, but OpenSUSE 9 2316 contains a buggy "glibc 2.3.2". 2317 2318 The symptom of the bug is that everything crashes on startup, saying: 2319 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2320 2321 Saying Y here changes the default value of the vdso32 boot 2322 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2323 This works around the glibc bug but hurts performance. 2324 2325 If unsure, say N: if you are compiling your own kernel, you 2326 are unlikely to be using a buggy version of glibc. 2327 2328choice 2329 prompt "vsyscall table for legacy applications" 2330 depends on X86_64 2331 default LEGACY_VSYSCALL_XONLY 2332 help 2333 Legacy user code that does not know how to find the vDSO expects 2334 to be able to issue three syscalls by calling fixed addresses in 2335 kernel space. Since this location is not randomized with ASLR, 2336 it can be used to assist security vulnerability exploitation. 2337 2338 This setting can be changed at boot time via the kernel command 2339 line parameter vsyscall=[emulate|xonly|none]. 2340 2341 On a system with recent enough glibc (2.14 or newer) and no 2342 static binaries, you can say None without a performance penalty 2343 to improve security. 2344 2345 If unsure, select "Emulate execution only". 2346 2347 config LEGACY_VSYSCALL_EMULATE 2348 bool "Full emulation" 2349 help 2350 The kernel traps and emulates calls into the fixed vsyscall 2351 address mapping. This makes the mapping non-executable, but 2352 it still contains readable known contents, which could be 2353 used in certain rare security vulnerability exploits. This 2354 configuration is recommended when using legacy userspace 2355 that still uses vsyscalls along with legacy binary 2356 instrumentation tools that require code to be readable. 2357 2358 An example of this type of legacy userspace is running 2359 Pin on an old binary that still uses vsyscalls. 2360 2361 config LEGACY_VSYSCALL_XONLY 2362 bool "Emulate execution only" 2363 help 2364 The kernel traps and emulates calls into the fixed vsyscall 2365 address mapping and does not allow reads. This 2366 configuration is recommended when userspace might use the 2367 legacy vsyscall area but support for legacy binary 2368 instrumentation of legacy code is not needed. It mitigates 2369 certain uses of the vsyscall area as an ASLR-bypassing 2370 buffer. 2371 2372 config LEGACY_VSYSCALL_NONE 2373 bool "None" 2374 help 2375 There will be no vsyscall mapping at all. This will 2376 eliminate any risk of ASLR bypass due to the vsyscall 2377 fixed address mapping. Attempts to use the vsyscalls 2378 will be reported to dmesg, so that either old or 2379 malicious userspace programs can be identified. 2380 2381endchoice 2382 2383config CMDLINE_BOOL 2384 bool "Built-in kernel command line" 2385 ---help--- 2386 Allow for specifying boot arguments to the kernel at 2387 build time. On some systems (e.g. embedded ones), it is 2388 necessary or convenient to provide some or all of the 2389 kernel boot arguments with the kernel itself (that is, 2390 to not rely on the boot loader to provide them.) 2391 2392 To compile command line arguments into the kernel, 2393 set this option to 'Y', then fill in the 2394 boot arguments in CONFIG_CMDLINE. 2395 2396 Systems with fully functional boot loaders (i.e. non-embedded) 2397 should leave this option set to 'N'. 2398 2399config CMDLINE 2400 string "Built-in kernel command string" 2401 depends on CMDLINE_BOOL 2402 default "" 2403 ---help--- 2404 Enter arguments here that should be compiled into the kernel 2405 image and used at boot time. If the boot loader provides a 2406 command line at boot time, it is appended to this string to 2407 form the full kernel command line, when the system boots. 2408 2409 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2410 change this behavior. 2411 2412 In most cases, the command line (whether built-in or provided 2413 by the boot loader) should specify the device for the root 2414 file system. 2415 2416config CMDLINE_OVERRIDE 2417 bool "Built-in command line overrides boot loader arguments" 2418 depends on CMDLINE_BOOL && CMDLINE != "" 2419 ---help--- 2420 Set this option to 'Y' to have the kernel ignore the boot loader 2421 command line, and use ONLY the built-in command line. 2422 2423 This is used to work around broken boot loaders. This should 2424 be set to 'N' under normal conditions. 2425 2426config MODIFY_LDT_SYSCALL 2427 bool "Enable the LDT (local descriptor table)" if EXPERT 2428 default y 2429 ---help--- 2430 Linux can allow user programs to install a per-process x86 2431 Local Descriptor Table (LDT) using the modify_ldt(2) system 2432 call. This is required to run 16-bit or segmented code such as 2433 DOSEMU or some Wine programs. It is also used by some very old 2434 threading libraries. 2435 2436 Enabling this feature adds a small amount of overhead to 2437 context switches and increases the low-level kernel attack 2438 surface. Disabling it removes the modify_ldt(2) system call. 2439 2440 Saying 'N' here may make sense for embedded or server kernels. 2441 2442source "kernel/livepatch/Kconfig" 2443 2444endmenu 2445 2446config ARCH_HAS_ADD_PAGES 2447 def_bool y 2448 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2449 2450config ARCH_ENABLE_MEMORY_HOTPLUG 2451 def_bool y 2452 depends on X86_64 || (X86_32 && HIGHMEM) 2453 2454config ARCH_ENABLE_MEMORY_HOTREMOVE 2455 def_bool y 2456 depends on MEMORY_HOTPLUG 2457 2458config USE_PERCPU_NUMA_NODE_ID 2459 def_bool y 2460 depends on NUMA 2461 2462config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2463 def_bool y 2464 depends on X86_64 || X86_PAE 2465 2466config ARCH_ENABLE_HUGEPAGE_MIGRATION 2467 def_bool y 2468 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2469 2470config ARCH_ENABLE_THP_MIGRATION 2471 def_bool y 2472 depends on X86_64 && TRANSPARENT_HUGEPAGE 2473 2474menu "Power management and ACPI options" 2475 2476config ARCH_HIBERNATION_HEADER 2477 def_bool y 2478 depends on HIBERNATION 2479 2480source "kernel/power/Kconfig" 2481 2482source "drivers/acpi/Kconfig" 2483 2484source "drivers/sfi/Kconfig" 2485 2486config X86_APM_BOOT 2487 def_bool y 2488 depends on APM 2489 2490menuconfig APM 2491 tristate "APM (Advanced Power Management) BIOS support" 2492 depends on X86_32 && PM_SLEEP 2493 ---help--- 2494 APM is a BIOS specification for saving power using several different 2495 techniques. This is mostly useful for battery powered laptops with 2496 APM compliant BIOSes. If you say Y here, the system time will be 2497 reset after a RESUME operation, the /proc/apm device will provide 2498 battery status information, and user-space programs will receive 2499 notification of APM "events" (e.g. battery status change). 2500 2501 If you select "Y" here, you can disable actual use of the APM 2502 BIOS by passing the "apm=off" option to the kernel at boot time. 2503 2504 Note that the APM support is almost completely disabled for 2505 machines with more than one CPU. 2506 2507 In order to use APM, you will need supporting software. For location 2508 and more information, read <file:Documentation/power/apm-acpi.rst> 2509 and the Battery Powered Linux mini-HOWTO, available from 2510 <http://www.tldp.org/docs.html#howto>. 2511 2512 This driver does not spin down disk drives (see the hdparm(8) 2513 manpage ("man 8 hdparm") for that), and it doesn't turn off 2514 VESA-compliant "green" monitors. 2515 2516 This driver does not support the TI 4000M TravelMate and the ACER 2517 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2518 desktop machines also don't have compliant BIOSes, and this driver 2519 may cause those machines to panic during the boot phase. 2520 2521 Generally, if you don't have a battery in your machine, there isn't 2522 much point in using this driver and you should say N. If you get 2523 random kernel OOPSes or reboots that don't seem to be related to 2524 anything, try disabling/enabling this option (or disabling/enabling 2525 APM in your BIOS). 2526 2527 Some other things you should try when experiencing seemingly random, 2528 "weird" problems: 2529 2530 1) make sure that you have enough swap space and that it is 2531 enabled. 2532 2) pass the "no-hlt" option to the kernel 2533 3) switch on floating point emulation in the kernel and pass 2534 the "no387" option to the kernel 2535 4) pass the "floppy=nodma" option to the kernel 2536 5) pass the "mem=4M" option to the kernel (thereby disabling 2537 all but the first 4 MB of RAM) 2538 6) make sure that the CPU is not over clocked. 2539 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2540 8) disable the cache from your BIOS settings 2541 9) install a fan for the video card or exchange video RAM 2542 10) install a better fan for the CPU 2543 11) exchange RAM chips 2544 12) exchange the motherboard. 2545 2546 To compile this driver as a module, choose M here: the 2547 module will be called apm. 2548 2549if APM 2550 2551config APM_IGNORE_USER_SUSPEND 2552 bool "Ignore USER SUSPEND" 2553 ---help--- 2554 This option will ignore USER SUSPEND requests. On machines with a 2555 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2556 series notebooks, it is necessary to say Y because of a BIOS bug. 2557 2558config APM_DO_ENABLE 2559 bool "Enable PM at boot time" 2560 ---help--- 2561 Enable APM features at boot time. From page 36 of the APM BIOS 2562 specification: "When disabled, the APM BIOS does not automatically 2563 power manage devices, enter the Standby State, enter the Suspend 2564 State, or take power saving steps in response to CPU Idle calls." 2565 This driver will make CPU Idle calls when Linux is idle (unless this 2566 feature is turned off -- see "Do CPU IDLE calls", below). This 2567 should always save battery power, but more complicated APM features 2568 will be dependent on your BIOS implementation. You may need to turn 2569 this option off if your computer hangs at boot time when using APM 2570 support, or if it beeps continuously instead of suspending. Turn 2571 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2572 T400CDT. This is off by default since most machines do fine without 2573 this feature. 2574 2575config APM_CPU_IDLE 2576 depends on CPU_IDLE 2577 bool "Make CPU Idle calls when idle" 2578 ---help--- 2579 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2580 On some machines, this can activate improved power savings, such as 2581 a slowed CPU clock rate, when the machine is idle. These idle calls 2582 are made after the idle loop has run for some length of time (e.g., 2583 333 mS). On some machines, this will cause a hang at boot time or 2584 whenever the CPU becomes idle. (On machines with more than one CPU, 2585 this option does nothing.) 2586 2587config APM_DISPLAY_BLANK 2588 bool "Enable console blanking using APM" 2589 ---help--- 2590 Enable console blanking using the APM. Some laptops can use this to 2591 turn off the LCD backlight when the screen blanker of the Linux 2592 virtual console blanks the screen. Note that this is only used by 2593 the virtual console screen blanker, and won't turn off the backlight 2594 when using the X Window system. This also doesn't have anything to 2595 do with your VESA-compliant power-saving monitor. Further, this 2596 option doesn't work for all laptops -- it might not turn off your 2597 backlight at all, or it might print a lot of errors to the console, 2598 especially if you are using gpm. 2599 2600config APM_ALLOW_INTS 2601 bool "Allow interrupts during APM BIOS calls" 2602 ---help--- 2603 Normally we disable external interrupts while we are making calls to 2604 the APM BIOS as a measure to lessen the effects of a badly behaving 2605 BIOS implementation. The BIOS should reenable interrupts if it 2606 needs to. Unfortunately, some BIOSes do not -- especially those in 2607 many of the newer IBM Thinkpads. If you experience hangs when you 2608 suspend, try setting this to Y. Otherwise, say N. 2609 2610endif # APM 2611 2612source "drivers/cpufreq/Kconfig" 2613 2614source "drivers/cpuidle/Kconfig" 2615 2616source "drivers/idle/Kconfig" 2617 2618endmenu 2619 2620 2621menu "Bus options (PCI etc.)" 2622 2623choice 2624 prompt "PCI access mode" 2625 depends on X86_32 && PCI 2626 default PCI_GOANY 2627 ---help--- 2628 On PCI systems, the BIOS can be used to detect the PCI devices and 2629 determine their configuration. However, some old PCI motherboards 2630 have BIOS bugs and may crash if this is done. Also, some embedded 2631 PCI-based systems don't have any BIOS at all. Linux can also try to 2632 detect the PCI hardware directly without using the BIOS. 2633 2634 With this option, you can specify how Linux should detect the 2635 PCI devices. If you choose "BIOS", the BIOS will be used, 2636 if you choose "Direct", the BIOS won't be used, and if you 2637 choose "MMConfig", then PCI Express MMCONFIG will be used. 2638 If you choose "Any", the kernel will try MMCONFIG, then the 2639 direct access method and falls back to the BIOS if that doesn't 2640 work. If unsure, go with the default, which is "Any". 2641 2642config PCI_GOBIOS 2643 bool "BIOS" 2644 2645config PCI_GOMMCONFIG 2646 bool "MMConfig" 2647 2648config PCI_GODIRECT 2649 bool "Direct" 2650 2651config PCI_GOOLPC 2652 bool "OLPC XO-1" 2653 depends on OLPC 2654 2655config PCI_GOANY 2656 bool "Any" 2657 2658endchoice 2659 2660config PCI_BIOS 2661 def_bool y 2662 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2663 2664# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2665config PCI_DIRECT 2666 def_bool y 2667 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2668 2669config PCI_MMCONFIG 2670 bool "Support mmconfig PCI config space access" if X86_64 2671 default y 2672 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2673 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2674 2675config PCI_OLPC 2676 def_bool y 2677 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2678 2679config PCI_XEN 2680 def_bool y 2681 depends on PCI && XEN 2682 select SWIOTLB_XEN 2683 2684config MMCONF_FAM10H 2685 def_bool y 2686 depends on X86_64 && PCI_MMCONFIG && ACPI 2687 2688config PCI_CNB20LE_QUIRK 2689 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2690 depends on PCI 2691 help 2692 Read the PCI windows out of the CNB20LE host bridge. This allows 2693 PCI hotplug to work on systems with the CNB20LE chipset which do 2694 not have ACPI. 2695 2696 There's no public spec for this chipset, and this functionality 2697 is known to be incomplete. 2698 2699 You should say N unless you know you need this. 2700 2701config ISA_BUS 2702 bool "ISA bus support on modern systems" if EXPERT 2703 help 2704 Expose ISA bus device drivers and options available for selection and 2705 configuration. Enable this option if your target machine has an ISA 2706 bus. ISA is an older system, displaced by PCI and newer bus 2707 architectures -- if your target machine is modern, it probably does 2708 not have an ISA bus. 2709 2710 If unsure, say N. 2711 2712# x86_64 have no ISA slots, but can have ISA-style DMA. 2713config ISA_DMA_API 2714 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2715 default y 2716 help 2717 Enables ISA-style DMA support for devices requiring such controllers. 2718 If unsure, say Y. 2719 2720if X86_32 2721 2722config ISA 2723 bool "ISA support" 2724 ---help--- 2725 Find out whether you have ISA slots on your motherboard. ISA is the 2726 name of a bus system, i.e. the way the CPU talks to the other stuff 2727 inside your box. Other bus systems are PCI, EISA, MicroChannel 2728 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2729 newer boards don't support it. If you have ISA, say Y, otherwise N. 2730 2731config SCx200 2732 tristate "NatSemi SCx200 support" 2733 ---help--- 2734 This provides basic support for National Semiconductor's 2735 (now AMD's) Geode processors. The driver probes for the 2736 PCI-IDs of several on-chip devices, so its a good dependency 2737 for other scx200_* drivers. 2738 2739 If compiled as a module, the driver is named scx200. 2740 2741config SCx200HR_TIMER 2742 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2743 depends on SCx200 2744 default y 2745 ---help--- 2746 This driver provides a clocksource built upon the on-chip 2747 27MHz high-resolution timer. Its also a workaround for 2748 NSC Geode SC-1100's buggy TSC, which loses time when the 2749 processor goes idle (as is done by the scheduler). The 2750 other workaround is idle=poll boot option. 2751 2752config OLPC 2753 bool "One Laptop Per Child support" 2754 depends on !X86_PAE 2755 select GPIOLIB 2756 select OF 2757 select OF_PROMTREE 2758 select IRQ_DOMAIN 2759 select OLPC_EC 2760 ---help--- 2761 Add support for detecting the unique features of the OLPC 2762 XO hardware. 2763 2764config OLPC_XO1_PM 2765 bool "OLPC XO-1 Power Management" 2766 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2767 ---help--- 2768 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2769 2770config OLPC_XO1_RTC 2771 bool "OLPC XO-1 Real Time Clock" 2772 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2773 ---help--- 2774 Add support for the XO-1 real time clock, which can be used as a 2775 programmable wakeup source. 2776 2777config OLPC_XO1_SCI 2778 bool "OLPC XO-1 SCI extras" 2779 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2780 depends on INPUT=y 2781 select POWER_SUPPLY 2782 ---help--- 2783 Add support for SCI-based features of the OLPC XO-1 laptop: 2784 - EC-driven system wakeups 2785 - Power button 2786 - Ebook switch 2787 - Lid switch 2788 - AC adapter status updates 2789 - Battery status updates 2790 2791config OLPC_XO15_SCI 2792 bool "OLPC XO-1.5 SCI extras" 2793 depends on OLPC && ACPI 2794 select POWER_SUPPLY 2795 ---help--- 2796 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2797 - EC-driven system wakeups 2798 - AC adapter status updates 2799 - Battery status updates 2800 2801config ALIX 2802 bool "PCEngines ALIX System Support (LED setup)" 2803 select GPIOLIB 2804 ---help--- 2805 This option enables system support for the PCEngines ALIX. 2806 At present this just sets up LEDs for GPIO control on 2807 ALIX2/3/6 boards. However, other system specific setup should 2808 get added here. 2809 2810 Note: You must still enable the drivers for GPIO and LED support 2811 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2812 2813 Note: You have to set alix.force=1 for boards with Award BIOS. 2814 2815config NET5501 2816 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2817 select GPIOLIB 2818 ---help--- 2819 This option enables system support for the Soekris Engineering net5501. 2820 2821config GEOS 2822 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2823 select GPIOLIB 2824 depends on DMI 2825 ---help--- 2826 This option enables system support for the Traverse Technologies GEOS. 2827 2828config TS5500 2829 bool "Technologic Systems TS-5500 platform support" 2830 depends on MELAN 2831 select CHECK_SIGNATURE 2832 select NEW_LEDS 2833 select LEDS_CLASS 2834 ---help--- 2835 This option enables system support for the Technologic Systems TS-5500. 2836 2837endif # X86_32 2838 2839config AMD_NB 2840 def_bool y 2841 depends on CPU_SUP_AMD && PCI 2842 2843config X86_SYSFB 2844 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2845 help 2846 Firmwares often provide initial graphics framebuffers so the BIOS, 2847 bootloader or kernel can show basic video-output during boot for 2848 user-guidance and debugging. Historically, x86 used the VESA BIOS 2849 Extensions and EFI-framebuffers for this, which are mostly limited 2850 to x86. 2851 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2852 framebuffers so the new generic system-framebuffer drivers can be 2853 used on x86. If the framebuffer is not compatible with the generic 2854 modes, it is advertised as fallback platform framebuffer so legacy 2855 drivers like efifb, vesafb and uvesafb can pick it up. 2856 If this option is not selected, all system framebuffers are always 2857 marked as fallback platform framebuffers as usual. 2858 2859 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2860 not be able to pick up generic system framebuffers if this option 2861 is selected. You are highly encouraged to enable simplefb as 2862 replacement if you select this option. simplefb can correctly deal 2863 with generic system framebuffers. But you should still keep vesafb 2864 and others enabled as fallback if a system framebuffer is 2865 incompatible with simplefb. 2866 2867 If unsure, say Y. 2868 2869endmenu 2870 2871 2872menu "Binary Emulations" 2873 2874config IA32_EMULATION 2875 bool "IA32 Emulation" 2876 depends on X86_64 2877 select ARCH_WANT_OLD_COMPAT_IPC 2878 select BINFMT_ELF 2879 select COMPAT_BINFMT_ELF 2880 select COMPAT_OLD_SIGACTION 2881 ---help--- 2882 Include code to run legacy 32-bit programs under a 2883 64-bit kernel. You should likely turn this on, unless you're 2884 100% sure that you don't have any 32-bit programs left. 2885 2886config IA32_AOUT 2887 tristate "IA32 a.out support" 2888 depends on IA32_EMULATION 2889 depends on BROKEN 2890 ---help--- 2891 Support old a.out binaries in the 32bit emulation. 2892 2893config X86_X32 2894 bool "x32 ABI for 64-bit mode" 2895 depends on X86_64 2896 ---help--- 2897 Include code to run binaries for the x32 native 32-bit ABI 2898 for 64-bit processors. An x32 process gets access to the 2899 full 64-bit register file and wide data path while leaving 2900 pointers at 32 bits for smaller memory footprint. 2901 2902 You will need a recent binutils (2.22 or later) with 2903 elf32_x86_64 support enabled to compile a kernel with this 2904 option set. 2905 2906config COMPAT_32 2907 def_bool y 2908 depends on IA32_EMULATION || X86_32 2909 select HAVE_UID16 2910 select OLD_SIGSUSPEND3 2911 2912config COMPAT 2913 def_bool y 2914 depends on IA32_EMULATION || X86_X32 2915 2916if COMPAT 2917config COMPAT_FOR_U64_ALIGNMENT 2918 def_bool y 2919 2920config SYSVIPC_COMPAT 2921 def_bool y 2922 depends on SYSVIPC 2923endif 2924 2925endmenu 2926 2927 2928config HAVE_ATOMIC_IOMAP 2929 def_bool y 2930 depends on X86_32 2931 2932source "drivers/firmware/Kconfig" 2933 2934source "arch/x86/kvm/Kconfig" 2935 2936source "arch/x86/Kconfig.assembler" 2937