1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_DEBUG_STACKOVERFLOW 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 select GENERIC_VDSO_32 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE 27 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select NEED_DMA_MAP_STATE 32 select SWIOTLB 33 select ARCH_HAS_SYSCALL_WRAPPER 34 35config FORCE_DYNAMIC_FTRACE 36 def_bool y 37 depends on X86_32 38 depends on FUNCTION_TRACER 39 select DYNAMIC_FTRACE 40 help 41 We keep the static function tracing (!DYNAMIC_FTRACE) around 42 in order to test the non static function tracing in the 43 generic code, as other architectures still use it. But we 44 only need to keep it around for x86_64. No need to keep it 45 for x86_32. For x86_32, force DYNAMIC_FTRACE. 46# 47# Arch settings 48# 49# ( Note that options that are marked 'if X86_64' could in principle be 50# ported to 32-bit as well. ) 51# 52config X86 53 def_bool y 54 # 55 # Note: keep this list sorted alphabetically 56 # 57 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 59 select ARCH_32BIT_OFF_T if X86_32 60 select ARCH_CLOCKSOURCE_DATA 61 select ARCH_CLOCKSOURCE_INIT 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 63 select ARCH_HAS_DEBUG_VIRTUAL 64 select ARCH_HAS_DEVMEM_IS_ALLOWED 65 select ARCH_HAS_ELF_RANDOMIZE 66 select ARCH_HAS_FAST_MULTIPLIER 67 select ARCH_HAS_FILTER_PGPROT 68 select ARCH_HAS_FORTIFY_SOURCE 69 select ARCH_HAS_GCOV_PROFILE_ALL 70 select ARCH_HAS_KCOV if X86_64 71 select ARCH_HAS_MEM_ENCRYPT 72 select ARCH_HAS_MEMBARRIER_SYNC_CORE 73 select ARCH_HAS_PMEM_API if X86_64 74 select ARCH_HAS_PTE_DEVMAP if X86_64 75 select ARCH_HAS_PTE_SPECIAL 76 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 77 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 78 select ARCH_HAS_SET_MEMORY 79 select ARCH_HAS_SET_DIRECT_MAP 80 select ARCH_HAS_STRICT_KERNEL_RWX 81 select ARCH_HAS_STRICT_MODULE_RWX 82 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 83 select ARCH_HAS_UBSAN_SANITIZE_ALL 84 select ARCH_HAVE_NMI_SAFE_CMPXCHG 85 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 86 select ARCH_MIGHT_HAVE_PC_PARPORT 87 select ARCH_MIGHT_HAVE_PC_SERIO 88 select ARCH_STACKWALK 89 select ARCH_SUPPORTS_ACPI 90 select ARCH_SUPPORTS_ATOMIC_RMW 91 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 92 select ARCH_USE_BUILTIN_BSWAP 93 select ARCH_USE_QUEUED_RWLOCKS 94 select ARCH_USE_QUEUED_SPINLOCKS 95 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 96 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 97 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 98 select ARCH_WANT_HUGE_PMD_SHARE 99 select ARCH_WANTS_THP_SWAP if X86_64 100 select BUILDTIME_TABLE_SORT 101 select CLKEVT_I8253 102 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 103 select CLOCKSOURCE_WATCHDOG 104 select DCACHE_WORD_ACCESS 105 select EDAC_ATOMIC_SCRUB 106 select EDAC_SUPPORT 107 select GENERIC_CLOCKEVENTS 108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 109 select GENERIC_CLOCKEVENTS_MIN_ADJUST 110 select GENERIC_CMOS_UPDATE 111 select GENERIC_CPU_AUTOPROBE 112 select GENERIC_CPU_VULNERABILITIES 113 select GENERIC_EARLY_IOREMAP 114 select GENERIC_FIND_FIRST_BIT 115 select GENERIC_IOMAP 116 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 117 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 118 select GENERIC_IRQ_MIGRATION if SMP 119 select GENERIC_IRQ_PROBE 120 select GENERIC_IRQ_RESERVATION_MODE 121 select GENERIC_IRQ_SHOW 122 select GENERIC_PENDING_IRQ if SMP 123 select GENERIC_PTDUMP 124 select GENERIC_SMP_IDLE_THREAD 125 select GENERIC_STRNCPY_FROM_USER 126 select GENERIC_STRNLEN_USER 127 select GENERIC_TIME_VSYSCALL 128 select GENERIC_GETTIMEOFDAY 129 select GENERIC_VDSO_TIME_NS 130 select GUP_GET_PTE_LOW_HIGH if X86_PAE 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_VMAP_STACK if X86_64 153 select HAVE_ARCH_WITHIN_STACK_FRAMES 154 select HAVE_ASM_MODVERSIONS 155 select HAVE_CMPXCHG_DOUBLE 156 select HAVE_CMPXCHG_LOCAL 157 select HAVE_CONTEXT_TRACKING if X86_64 158 select HAVE_COPY_THREAD_TLS 159 select HAVE_C_RECORDMCOUNT 160 select HAVE_DEBUG_KMEMLEAK 161 select HAVE_DMA_CONTIGUOUS 162 select HAVE_DYNAMIC_FTRACE 163 select HAVE_DYNAMIC_FTRACE_WITH_REGS 164 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 165 select HAVE_EBPF_JIT 166 select HAVE_EFFICIENT_UNALIGNED_ACCESS 167 select HAVE_EISA 168 select HAVE_EXIT_THREAD 169 select HAVE_FAST_GUP 170 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 171 select HAVE_FTRACE_MCOUNT_RECORD 172 select HAVE_FUNCTION_GRAPH_TRACER 173 select HAVE_FUNCTION_TRACER 174 select HAVE_GCC_PLUGINS 175 select HAVE_HW_BREAKPOINT 176 select HAVE_IDE 177 select HAVE_IOREMAP_PROT 178 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 179 select HAVE_IRQ_TIME_ACCOUNTING 180 select HAVE_KERNEL_BZIP2 181 select HAVE_KERNEL_GZIP 182 select HAVE_KERNEL_LZ4 183 select HAVE_KERNEL_LZMA 184 select HAVE_KERNEL_LZO 185 select HAVE_KERNEL_XZ 186 select HAVE_KPROBES 187 select HAVE_KPROBES_ON_FTRACE 188 select HAVE_FUNCTION_ERROR_INJECTION 189 select HAVE_KRETPROBES 190 select HAVE_KVM 191 select HAVE_LIVEPATCH if X86_64 192 select HAVE_MEMBLOCK_NODE_MAP 193 select HAVE_MIXED_BREAKPOINTS_REGS 194 select HAVE_MOD_ARCH_SPECIFIC 195 select HAVE_MOVE_PMD 196 select HAVE_NMI 197 select HAVE_OPROFILE 198 select HAVE_OPTPROBES 199 select HAVE_PCSPKR_PLATFORM 200 select HAVE_PERF_EVENTS 201 select HAVE_PERF_EVENTS_NMI 202 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 203 select HAVE_PCI 204 select HAVE_PERF_REGS 205 select HAVE_PERF_USER_STACK_DUMP 206 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 207 select HAVE_REGS_AND_STACK_ACCESS_API 208 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 209 select HAVE_FUNCTION_ARG_ACCESS_API 210 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 211 select HAVE_STACK_VALIDATION if X86_64 212 select HAVE_RSEQ 213 select HAVE_SYSCALL_TRACEPOINTS 214 select HAVE_UNSTABLE_SCHED_CLOCK 215 select HAVE_USER_RETURN_NOTIFIER 216 select HAVE_GENERIC_VDSO 217 select HOTPLUG_SMT if SMP 218 select IRQ_FORCED_THREADING 219 select NEED_SG_DMA_LENGTH 220 select PCI_DOMAINS if PCI 221 select PCI_LOCKLESS_CONFIG if PCI 222 select PERF_EVENTS 223 select RTC_LIB 224 select RTC_MC146818_LIB 225 select SPARSE_IRQ 226 select SRCU 227 select SYSCTL_EXCEPTION_TRACE 228 select THREAD_INFO_IN_TASK 229 select USER_STACKTRACE_SUPPORT 230 select VIRT_TO_BUS 231 select X86_FEATURE_NAMES if PROC_FS 232 select PROC_PID_ARCH_STATUS if PROC_FS 233 234config INSTRUCTION_DECODER 235 def_bool y 236 depends on KPROBES || PERF_EVENTS || UPROBES 237 238config OUTPUT_FORMAT 239 string 240 default "elf32-i386" if X86_32 241 default "elf64-x86-64" if X86_64 242 243config ARCH_DEFCONFIG 244 string 245 default "arch/x86/configs/i386_defconfig" if X86_32 246 default "arch/x86/configs/x86_64_defconfig" if X86_64 247 248config LOCKDEP_SUPPORT 249 def_bool y 250 251config STACKTRACE_SUPPORT 252 def_bool y 253 254config MMU 255 def_bool y 256 257config ARCH_MMAP_RND_BITS_MIN 258 default 28 if 64BIT 259 default 8 260 261config ARCH_MMAP_RND_BITS_MAX 262 default 32 if 64BIT 263 default 16 264 265config ARCH_MMAP_RND_COMPAT_BITS_MIN 266 default 8 267 268config ARCH_MMAP_RND_COMPAT_BITS_MAX 269 default 16 270 271config SBUS 272 bool 273 274config GENERIC_ISA_DMA 275 def_bool y 276 depends on ISA_DMA_API 277 278config GENERIC_BUG 279 def_bool y 280 depends on BUG 281 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 282 283config GENERIC_BUG_RELATIVE_POINTERS 284 bool 285 286config ARCH_MAY_HAVE_PC_FDC 287 def_bool y 288 depends on ISA_DMA_API 289 290config GENERIC_CALIBRATE_DELAY 291 def_bool y 292 293config ARCH_HAS_CPU_RELAX 294 def_bool y 295 296config ARCH_HAS_CACHE_LINE_SIZE 297 def_bool y 298 299config ARCH_HAS_FILTER_PGPROT 300 def_bool y 301 302config HAVE_SETUP_PER_CPU_AREA 303 def_bool y 304 305config NEED_PER_CPU_EMBED_FIRST_CHUNK 306 def_bool y 307 308config NEED_PER_CPU_PAGE_FIRST_CHUNK 309 def_bool y 310 311config ARCH_HIBERNATION_POSSIBLE 312 def_bool y 313 314config ARCH_SUSPEND_POSSIBLE 315 def_bool y 316 317config ARCH_WANT_GENERAL_HUGETLB 318 def_bool y 319 320config ZONE_DMA32 321 def_bool y if X86_64 322 323config AUDIT_ARCH 324 def_bool y if X86_64 325 326config ARCH_SUPPORTS_DEBUG_PAGEALLOC 327 def_bool y 328 329config KASAN_SHADOW_OFFSET 330 hex 331 depends on KASAN 332 default 0xdffffc0000000000 333 334config HAVE_INTEL_TXT 335 def_bool y 336 depends on INTEL_IOMMU && ACPI 337 338config X86_32_SMP 339 def_bool y 340 depends on X86_32 && SMP 341 342config X86_64_SMP 343 def_bool y 344 depends on X86_64 && SMP 345 346config X86_32_LAZY_GS 347 def_bool y 348 depends on X86_32 && !STACKPROTECTOR 349 350config ARCH_SUPPORTS_UPROBES 351 def_bool y 352 353config FIX_EARLYCON_MEM 354 def_bool y 355 356config DYNAMIC_PHYSICAL_MASK 357 bool 358 359config PGTABLE_LEVELS 360 int 361 default 5 if X86_5LEVEL 362 default 4 if X86_64 363 default 3 if X86_PAE 364 default 2 365 366config CC_HAS_SANE_STACKPROTECTOR 367 bool 368 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 369 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 370 help 371 We have to make sure stack protector is unconditionally disabled if 372 the compiler produces broken code. 373 374menu "Processor type and features" 375 376config ZONE_DMA 377 bool "DMA memory allocation support" if EXPERT 378 default y 379 help 380 DMA memory allocation support allows devices with less than 32-bit 381 addressing to allocate within the first 16MB of address space. 382 Disable if no such devices will be used. 383 384 If unsure, say Y. 385 386config SMP 387 bool "Symmetric multi-processing support" 388 ---help--- 389 This enables support for systems with more than one CPU. If you have 390 a system with only one CPU, say N. If you have a system with more 391 than one CPU, say Y. 392 393 If you say N here, the kernel will run on uni- and multiprocessor 394 machines, but will use only one CPU of a multiprocessor machine. If 395 you say Y here, the kernel will run on many, but not all, 396 uniprocessor machines. On a uniprocessor machine, the kernel 397 will run faster if you say N here. 398 399 Note that if you say Y here and choose architecture "586" or 400 "Pentium" under "Processor family", the kernel will not work on 486 401 architectures. Similarly, multiprocessor kernels for the "PPro" 402 architecture may not work on all Pentium based boards. 403 404 People using multiprocessor machines who say Y here should also say 405 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 406 Management" code will be disabled if you say Y here. 407 408 See also <file:Documentation/x86/i386/IO-APIC.rst>, 409 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 410 <http://www.tldp.org/docs.html#howto>. 411 412 If you don't know what to do here, say N. 413 414config X86_FEATURE_NAMES 415 bool "Processor feature human-readable names" if EMBEDDED 416 default y 417 ---help--- 418 This option compiles in a table of x86 feature bits and corresponding 419 names. This is required to support /proc/cpuinfo and a few kernel 420 messages. You can disable this to save space, at the expense of 421 making those few kernel messages show numeric feature bits instead. 422 423 If in doubt, say Y. 424 425config X86_X2APIC 426 bool "Support x2apic" 427 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 428 ---help--- 429 This enables x2apic support on CPUs that have this feature. 430 431 This allows 32-bit apic IDs (so it can support very large systems), 432 and accesses the local apic via MSRs not via mmio. 433 434 If you don't know what to do here, say N. 435 436config X86_MPPARSE 437 bool "Enable MPS table" if ACPI || SFI 438 default y 439 depends on X86_LOCAL_APIC 440 ---help--- 441 For old smp systems that do not have proper acpi support. Newer systems 442 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 443 444config GOLDFISH 445 def_bool y 446 depends on X86_GOLDFISH 447 448config RETPOLINE 449 bool "Avoid speculative indirect branches in kernel" 450 default y 451 select STACK_VALIDATION if HAVE_STACK_VALIDATION 452 help 453 Compile kernel with the retpoline compiler options to guard against 454 kernel-to-user data leaks by avoiding speculative indirect 455 branches. Requires a compiler with -mindirect-branch=thunk-extern 456 support for full protection. The kernel may run slower. 457 458config X86_CPU_RESCTRL 459 bool "x86 CPU resource control support" 460 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 461 select KERNFS 462 select PROC_CPU_RESCTRL if PROC_FS 463 help 464 Enable x86 CPU resource control support. 465 466 Provide support for the allocation and monitoring of system resources 467 usage by the CPU. 468 469 Intel calls this Intel Resource Director Technology 470 (Intel(R) RDT). More information about RDT can be found in the 471 Intel x86 Architecture Software Developer Manual. 472 473 AMD calls this AMD Platform Quality of Service (AMD QoS). 474 More information about AMD QoS can be found in the AMD64 Technology 475 Platform Quality of Service Extensions manual. 476 477 Say N if unsure. 478 479if X86_32 480config X86_BIGSMP 481 bool "Support for big SMP systems with more than 8 CPUs" 482 depends on SMP 483 ---help--- 484 This option is needed for the systems that have more than 8 CPUs. 485 486config X86_EXTENDED_PLATFORM 487 bool "Support for extended (non-PC) x86 platforms" 488 default y 489 ---help--- 490 If you disable this option then the kernel will only support 491 standard PC platforms. (which covers the vast majority of 492 systems out there.) 493 494 If you enable this option then you'll be able to select support 495 for the following (non-PC) 32 bit x86 platforms: 496 Goldfish (Android emulator) 497 AMD Elan 498 RDC R-321x SoC 499 SGI 320/540 (Visual Workstation) 500 STA2X11-based (e.g. Northville) 501 Moorestown MID devices 502 503 If you have one of these systems, or if you want to build a 504 generic distribution kernel, say Y here - otherwise say N. 505endif 506 507if X86_64 508config X86_EXTENDED_PLATFORM 509 bool "Support for extended (non-PC) x86 platforms" 510 default y 511 ---help--- 512 If you disable this option then the kernel will only support 513 standard PC platforms. (which covers the vast majority of 514 systems out there.) 515 516 If you enable this option then you'll be able to select support 517 for the following (non-PC) 64 bit x86 platforms: 518 Numascale NumaChip 519 ScaleMP vSMP 520 SGI Ultraviolet 521 522 If you have one of these systems, or if you want to build a 523 generic distribution kernel, say Y here - otherwise say N. 524endif 525# This is an alphabetically sorted list of 64 bit extended platforms 526# Please maintain the alphabetic order if and when there are additions 527config X86_NUMACHIP 528 bool "Numascale NumaChip" 529 depends on X86_64 530 depends on X86_EXTENDED_PLATFORM 531 depends on NUMA 532 depends on SMP 533 depends on X86_X2APIC 534 depends on PCI_MMCONFIG 535 ---help--- 536 Adds support for Numascale NumaChip large-SMP systems. Needed to 537 enable more than ~168 cores. 538 If you don't have one of these, you should say N here. 539 540config X86_VSMP 541 bool "ScaleMP vSMP" 542 select HYPERVISOR_GUEST 543 select PARAVIRT 544 depends on X86_64 && PCI 545 depends on X86_EXTENDED_PLATFORM 546 depends on SMP 547 ---help--- 548 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 549 supposed to run on these EM64T-based machines. Only choose this option 550 if you have one of these machines. 551 552config X86_UV 553 bool "SGI Ultraviolet" 554 depends on X86_64 555 depends on X86_EXTENDED_PLATFORM 556 depends on NUMA 557 depends on EFI 558 depends on X86_X2APIC 559 depends on PCI 560 ---help--- 561 This option is needed in order to support SGI Ultraviolet systems. 562 If you don't have one of these, you should say N here. 563 564# Following is an alphabetically sorted list of 32 bit extended platforms 565# Please maintain the alphabetic order if and when there are additions 566 567config X86_GOLDFISH 568 bool "Goldfish (Virtual Platform)" 569 depends on X86_EXTENDED_PLATFORM 570 ---help--- 571 Enable support for the Goldfish virtual platform used primarily 572 for Android development. Unless you are building for the Android 573 Goldfish emulator say N here. 574 575config X86_INTEL_CE 576 bool "CE4100 TV platform" 577 depends on PCI 578 depends on PCI_GODIRECT 579 depends on X86_IO_APIC 580 depends on X86_32 581 depends on X86_EXTENDED_PLATFORM 582 select X86_REBOOTFIXUPS 583 select OF 584 select OF_EARLY_FLATTREE 585 ---help--- 586 Select for the Intel CE media processor (CE4100) SOC. 587 This option compiles in support for the CE4100 SOC for settop 588 boxes and media devices. 589 590config X86_INTEL_MID 591 bool "Intel MID platform support" 592 depends on X86_EXTENDED_PLATFORM 593 depends on X86_PLATFORM_DEVICES 594 depends on PCI 595 depends on X86_64 || (PCI_GOANY && X86_32) 596 depends on X86_IO_APIC 597 select SFI 598 select I2C 599 select DW_APB_TIMER 600 select APB_TIMER 601 select INTEL_SCU_IPC 602 select MFD_INTEL_MSIC 603 ---help--- 604 Select to build a kernel capable of supporting Intel MID (Mobile 605 Internet Device) platform systems which do not have the PCI legacy 606 interfaces. If you are building for a PC class system say N here. 607 608 Intel MID platforms are based on an Intel processor and chipset which 609 consume less power than most of the x86 derivatives. 610 611config X86_INTEL_QUARK 612 bool "Intel Quark platform support" 613 depends on X86_32 614 depends on X86_EXTENDED_PLATFORM 615 depends on X86_PLATFORM_DEVICES 616 depends on X86_TSC 617 depends on PCI 618 depends on PCI_GOANY 619 depends on X86_IO_APIC 620 select IOSF_MBI 621 select INTEL_IMR 622 select COMMON_CLK 623 ---help--- 624 Select to include support for Quark X1000 SoC. 625 Say Y here if you have a Quark based system such as the Arduino 626 compatible Intel Galileo. 627 628config X86_INTEL_LPSS 629 bool "Intel Low Power Subsystem Support" 630 depends on X86 && ACPI && PCI 631 select COMMON_CLK 632 select PINCTRL 633 select IOSF_MBI 634 ---help--- 635 Select to build support for Intel Low Power Subsystem such as 636 found on Intel Lynxpoint PCH. Selecting this option enables 637 things like clock tree (common clock framework) and pincontrol 638 which are needed by the LPSS peripheral drivers. 639 640config X86_AMD_PLATFORM_DEVICE 641 bool "AMD ACPI2Platform devices support" 642 depends on ACPI 643 select COMMON_CLK 644 select PINCTRL 645 ---help--- 646 Select to interpret AMD specific ACPI device to platform device 647 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 648 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 649 implemented under PINCTRL subsystem. 650 651config IOSF_MBI 652 tristate "Intel SoC IOSF Sideband support for SoC platforms" 653 depends on PCI 654 ---help--- 655 This option enables sideband register access support for Intel SoC 656 platforms. On these platforms the IOSF sideband is used in lieu of 657 MSR's for some register accesses, mostly but not limited to thermal 658 and power. Drivers may query the availability of this device to 659 determine if they need the sideband in order to work on these 660 platforms. The sideband is available on the following SoC products. 661 This list is not meant to be exclusive. 662 - BayTrail 663 - Braswell 664 - Quark 665 666 You should say Y if you are running a kernel on one of these SoC's. 667 668config IOSF_MBI_DEBUG 669 bool "Enable IOSF sideband access through debugfs" 670 depends on IOSF_MBI && DEBUG_FS 671 ---help--- 672 Select this option to expose the IOSF sideband access registers (MCR, 673 MDR, MCRX) through debugfs to write and read register information from 674 different units on the SoC. This is most useful for obtaining device 675 state information for debug and analysis. As this is a general access 676 mechanism, users of this option would have specific knowledge of the 677 device they want to access. 678 679 If you don't require the option or are in doubt, say N. 680 681config X86_RDC321X 682 bool "RDC R-321x SoC" 683 depends on X86_32 684 depends on X86_EXTENDED_PLATFORM 685 select M486 686 select X86_REBOOTFIXUPS 687 ---help--- 688 This option is needed for RDC R-321x system-on-chip, also known 689 as R-8610-(G). 690 If you don't have one of these chips, you should say N here. 691 692config X86_32_NON_STANDARD 693 bool "Support non-standard 32-bit SMP architectures" 694 depends on X86_32 && SMP 695 depends on X86_EXTENDED_PLATFORM 696 ---help--- 697 This option compiles in the bigsmp and STA2X11 default 698 subarchitectures. It is intended for a generic binary 699 kernel. If you select them all, kernel will probe it one by 700 one and will fallback to default. 701 702# Alphabetically sorted list of Non standard 32 bit platforms 703 704config X86_SUPPORTS_MEMORY_FAILURE 705 def_bool y 706 # MCE code calls memory_failure(): 707 depends on X86_MCE 708 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 709 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 710 depends on X86_64 || !SPARSEMEM 711 select ARCH_SUPPORTS_MEMORY_FAILURE 712 713config STA2X11 714 bool "STA2X11 Companion Chip Support" 715 depends on X86_32_NON_STANDARD && PCI 716 select SWIOTLB 717 select MFD_STA2X11 718 select GPIOLIB 719 ---help--- 720 This adds support for boards based on the STA2X11 IO-Hub, 721 a.k.a. "ConneXt". The chip is used in place of the standard 722 PC chipset, so all "standard" peripherals are missing. If this 723 option is selected the kernel will still be able to boot on 724 standard PC machines. 725 726config X86_32_IRIS 727 tristate "Eurobraille/Iris poweroff module" 728 depends on X86_32 729 ---help--- 730 The Iris machines from EuroBraille do not have APM or ACPI support 731 to shut themselves down properly. A special I/O sequence is 732 needed to do so, which is what this module does at 733 kernel shutdown. 734 735 This is only for Iris machines from EuroBraille. 736 737 If unused, say N. 738 739config SCHED_OMIT_FRAME_POINTER 740 def_bool y 741 prompt "Single-depth WCHAN output" 742 depends on X86 743 ---help--- 744 Calculate simpler /proc/<PID>/wchan values. If this option 745 is disabled then wchan values will recurse back to the 746 caller function. This provides more accurate wchan values, 747 at the expense of slightly more scheduling overhead. 748 749 If in doubt, say "Y". 750 751menuconfig HYPERVISOR_GUEST 752 bool "Linux guest support" 753 ---help--- 754 Say Y here to enable options for running Linux under various hyper- 755 visors. This option enables basic hypervisor detection and platform 756 setup. 757 758 If you say N, all options in this submenu will be skipped and 759 disabled, and Linux guest support won't be built in. 760 761if HYPERVISOR_GUEST 762 763config PARAVIRT 764 bool "Enable paravirtualization code" 765 ---help--- 766 This changes the kernel so it can modify itself when it is run 767 under a hypervisor, potentially improving performance significantly 768 over full virtualization. However, when run without a hypervisor 769 the kernel is theoretically slower and slightly larger. 770 771config PARAVIRT_XXL 772 bool 773 774config PARAVIRT_DEBUG 775 bool "paravirt-ops debugging" 776 depends on PARAVIRT && DEBUG_KERNEL 777 ---help--- 778 Enable to debug paravirt_ops internals. Specifically, BUG if 779 a paravirt_op is missing when it is called. 780 781config PARAVIRT_SPINLOCKS 782 bool "Paravirtualization layer for spinlocks" 783 depends on PARAVIRT && SMP 784 ---help--- 785 Paravirtualized spinlocks allow a pvops backend to replace the 786 spinlock implementation with something virtualization-friendly 787 (for example, block the virtual CPU rather than spinning). 788 789 It has a minimal impact on native kernels and gives a nice performance 790 benefit on paravirtualized KVM / Xen kernels. 791 792 If you are unsure how to answer this question, answer Y. 793 794config X86_HV_CALLBACK_VECTOR 795 def_bool n 796 797source "arch/x86/xen/Kconfig" 798 799config KVM_GUEST 800 bool "KVM Guest support (including kvmclock)" 801 depends on PARAVIRT 802 select PARAVIRT_CLOCK 803 select ARCH_CPUIDLE_HALTPOLL 804 default y 805 ---help--- 806 This option enables various optimizations for running under the KVM 807 hypervisor. It includes a paravirtualized clock, so that instead 808 of relying on a PIT (or probably other) emulation by the 809 underlying device model, the host provides the guest with 810 timing infrastructure such as time of day, and system time 811 812config ARCH_CPUIDLE_HALTPOLL 813 def_bool n 814 prompt "Disable host haltpoll when loading haltpoll driver" 815 help 816 If virtualized under KVM, disable host haltpoll. 817 818config PVH 819 bool "Support for running PVH guests" 820 ---help--- 821 This option enables the PVH entry point for guest virtual machines 822 as specified in the x86/HVM direct boot ABI. 823 824config KVM_DEBUG_FS 825 bool "Enable debug information for KVM Guests in debugfs" 826 depends on KVM_GUEST && DEBUG_FS 827 ---help--- 828 This option enables collection of various statistics for KVM guest. 829 Statistics are displayed in debugfs filesystem. Enabling this option 830 may incur significant overhead. 831 832config PARAVIRT_TIME_ACCOUNTING 833 bool "Paravirtual steal time accounting" 834 depends on PARAVIRT 835 ---help--- 836 Select this option to enable fine granularity task steal time 837 accounting. Time spent executing other tasks in parallel with 838 the current vCPU is discounted from the vCPU power. To account for 839 that, there can be a small performance impact. 840 841 If in doubt, say N here. 842 843config PARAVIRT_CLOCK 844 bool 845 846config JAILHOUSE_GUEST 847 bool "Jailhouse non-root cell support" 848 depends on X86_64 && PCI 849 select X86_PM_TIMER 850 ---help--- 851 This option allows to run Linux as guest in a Jailhouse non-root 852 cell. You can leave this option disabled if you only want to start 853 Jailhouse and run Linux afterwards in the root cell. 854 855config ACRN_GUEST 856 bool "ACRN Guest support" 857 depends on X86_64 858 select X86_HV_CALLBACK_VECTOR 859 help 860 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 861 a flexible, lightweight reference open-source hypervisor, built with 862 real-time and safety-criticality in mind. It is built for embedded 863 IOT with small footprint and real-time features. More details can be 864 found in https://projectacrn.org/. 865 866endif #HYPERVISOR_GUEST 867 868source "arch/x86/Kconfig.cpu" 869 870config HPET_TIMER 871 def_bool X86_64 872 prompt "HPET Timer Support" if X86_32 873 ---help--- 874 Use the IA-PC HPET (High Precision Event Timer) to manage 875 time in preference to the PIT and RTC, if a HPET is 876 present. 877 HPET is the next generation timer replacing legacy 8254s. 878 The HPET provides a stable time base on SMP 879 systems, unlike the TSC, but it is more expensive to access, 880 as it is off-chip. The interface used is documented 881 in the HPET spec, revision 1. 882 883 You can safely choose Y here. However, HPET will only be 884 activated if the platform and the BIOS support this feature. 885 Otherwise the 8254 will be used for timing services. 886 887 Choose N to continue using the legacy 8254 timer. 888 889config HPET_EMULATE_RTC 890 def_bool y 891 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 892 893config APB_TIMER 894 def_bool y if X86_INTEL_MID 895 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 896 select DW_APB_TIMER 897 depends on X86_INTEL_MID && SFI 898 help 899 APB timer is the replacement for 8254, HPET on X86 MID platforms. 900 The APBT provides a stable time base on SMP 901 systems, unlike the TSC, but it is more expensive to access, 902 as it is off-chip. APB timers are always running regardless of CPU 903 C states, they are used as per CPU clockevent device when possible. 904 905# Mark as expert because too many people got it wrong. 906# The code disables itself when not needed. 907config DMI 908 default y 909 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 910 bool "Enable DMI scanning" if EXPERT 911 ---help--- 912 Enabled scanning of DMI to identify machine quirks. Say Y 913 here unless you have verified that your setup is not 914 affected by entries in the DMI blacklist. Required by PNP 915 BIOS code. 916 917config GART_IOMMU 918 bool "Old AMD GART IOMMU support" 919 select IOMMU_HELPER 920 select SWIOTLB 921 depends on X86_64 && PCI && AMD_NB 922 ---help--- 923 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 924 GART based hardware IOMMUs. 925 926 The GART supports full DMA access for devices with 32-bit access 927 limitations, on systems with more than 3 GB. This is usually needed 928 for USB, sound, many IDE/SATA chipsets and some other devices. 929 930 Newer systems typically have a modern AMD IOMMU, supported via 931 the CONFIG_AMD_IOMMU=y config option. 932 933 In normal configurations this driver is only active when needed: 934 there's more than 3 GB of memory and the system contains a 935 32-bit limited device. 936 937 If unsure, say Y. 938 939config MAXSMP 940 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 941 depends on X86_64 && SMP && DEBUG_KERNEL 942 select CPUMASK_OFFSTACK 943 ---help--- 944 Enable maximum number of CPUS and NUMA Nodes for this architecture. 945 If unsure, say N. 946 947# 948# The maximum number of CPUs supported: 949# 950# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 951# and which can be configured interactively in the 952# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 953# 954# The ranges are different on 32-bit and 64-bit kernels, depending on 955# hardware capabilities and scalability features of the kernel. 956# 957# ( If MAXSMP is enabled we just use the highest possible value and disable 958# interactive configuration. ) 959# 960 961config NR_CPUS_RANGE_BEGIN 962 int 963 default NR_CPUS_RANGE_END if MAXSMP 964 default 1 if !SMP 965 default 2 966 967config NR_CPUS_RANGE_END 968 int 969 depends on X86_32 970 default 64 if SMP && X86_BIGSMP 971 default 8 if SMP && !X86_BIGSMP 972 default 1 if !SMP 973 974config NR_CPUS_RANGE_END 975 int 976 depends on X86_64 977 default 8192 if SMP && CPUMASK_OFFSTACK 978 default 512 if SMP && !CPUMASK_OFFSTACK 979 default 1 if !SMP 980 981config NR_CPUS_DEFAULT 982 int 983 depends on X86_32 984 default 32 if X86_BIGSMP 985 default 8 if SMP 986 default 1 if !SMP 987 988config NR_CPUS_DEFAULT 989 int 990 depends on X86_64 991 default 8192 if MAXSMP 992 default 64 if SMP 993 default 1 if !SMP 994 995config NR_CPUS 996 int "Maximum number of CPUs" if SMP && !MAXSMP 997 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 998 default NR_CPUS_DEFAULT 999 ---help--- 1000 This allows you to specify the maximum number of CPUs which this 1001 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1002 supported value is 8192, otherwise the maximum value is 512. The 1003 minimum value which makes sense is 2. 1004 1005 This is purely to save memory: each supported CPU adds about 8KB 1006 to the kernel image. 1007 1008config SCHED_SMT 1009 def_bool y if SMP 1010 1011config SCHED_MC 1012 def_bool y 1013 prompt "Multi-core scheduler support" 1014 depends on SMP 1015 ---help--- 1016 Multi-core scheduler support improves the CPU scheduler's decision 1017 making when dealing with multi-core CPU chips at a cost of slightly 1018 increased overhead in some places. If unsure say N here. 1019 1020config SCHED_MC_PRIO 1021 bool "CPU core priorities scheduler support" 1022 depends on SCHED_MC && CPU_SUP_INTEL 1023 select X86_INTEL_PSTATE 1024 select CPU_FREQ 1025 default y 1026 ---help--- 1027 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1028 core ordering determined at manufacturing time, which allows 1029 certain cores to reach higher turbo frequencies (when running 1030 single threaded workloads) than others. 1031 1032 Enabling this kernel feature teaches the scheduler about 1033 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1034 scheduler's CPU selection logic accordingly, so that higher 1035 overall system performance can be achieved. 1036 1037 This feature will have no effect on CPUs without this feature. 1038 1039 If unsure say Y here. 1040 1041config UP_LATE_INIT 1042 def_bool y 1043 depends on !SMP && X86_LOCAL_APIC 1044 1045config X86_UP_APIC 1046 bool "Local APIC support on uniprocessors" if !PCI_MSI 1047 default PCI_MSI 1048 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1049 ---help--- 1050 A local APIC (Advanced Programmable Interrupt Controller) is an 1051 integrated interrupt controller in the CPU. If you have a single-CPU 1052 system which has a processor with a local APIC, you can say Y here to 1053 enable and use it. If you say Y here even though your machine doesn't 1054 have a local APIC, then the kernel will still run with no slowdown at 1055 all. The local APIC supports CPU-generated self-interrupts (timer, 1056 performance counters), and the NMI watchdog which detects hard 1057 lockups. 1058 1059config X86_UP_IOAPIC 1060 bool "IO-APIC support on uniprocessors" 1061 depends on X86_UP_APIC 1062 ---help--- 1063 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1064 SMP-capable replacement for PC-style interrupt controllers. Most 1065 SMP systems and many recent uniprocessor systems have one. 1066 1067 If you have a single-CPU system with an IO-APIC, you can say Y here 1068 to use it. If you say Y here even though your machine doesn't have 1069 an IO-APIC, then the kernel will still run with no slowdown at all. 1070 1071config X86_LOCAL_APIC 1072 def_bool y 1073 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1074 select IRQ_DOMAIN_HIERARCHY 1075 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1076 1077config X86_IO_APIC 1078 def_bool y 1079 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1080 1081config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1082 bool "Reroute for broken boot IRQs" 1083 depends on X86_IO_APIC 1084 ---help--- 1085 This option enables a workaround that fixes a source of 1086 spurious interrupts. This is recommended when threaded 1087 interrupt handling is used on systems where the generation of 1088 superfluous "boot interrupts" cannot be disabled. 1089 1090 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1091 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1092 kernel does during interrupt handling). On chipsets where this 1093 boot IRQ generation cannot be disabled, this workaround keeps 1094 the original IRQ line masked so that only the equivalent "boot 1095 IRQ" is delivered to the CPUs. The workaround also tells the 1096 kernel to set up the IRQ handler on the boot IRQ line. In this 1097 way only one interrupt is delivered to the kernel. Otherwise 1098 the spurious second interrupt may cause the kernel to bring 1099 down (vital) interrupt lines. 1100 1101 Only affects "broken" chipsets. Interrupt sharing may be 1102 increased on these systems. 1103 1104config X86_MCE 1105 bool "Machine Check / overheating reporting" 1106 select GENERIC_ALLOCATOR 1107 default y 1108 ---help--- 1109 Machine Check support allows the processor to notify the 1110 kernel if it detects a problem (e.g. overheating, data corruption). 1111 The action the kernel takes depends on the severity of the problem, 1112 ranging from warning messages to halting the machine. 1113 1114config X86_MCELOG_LEGACY 1115 bool "Support for deprecated /dev/mcelog character device" 1116 depends on X86_MCE 1117 ---help--- 1118 Enable support for /dev/mcelog which is needed by the old mcelog 1119 userspace logging daemon. Consider switching to the new generation 1120 rasdaemon solution. 1121 1122config X86_MCE_INTEL 1123 def_bool y 1124 prompt "Intel MCE features" 1125 depends on X86_MCE && X86_LOCAL_APIC 1126 ---help--- 1127 Additional support for intel specific MCE features such as 1128 the thermal monitor. 1129 1130config X86_MCE_AMD 1131 def_bool y 1132 prompt "AMD MCE features" 1133 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1134 ---help--- 1135 Additional support for AMD specific MCE features such as 1136 the DRAM Error Threshold. 1137 1138config X86_ANCIENT_MCE 1139 bool "Support for old Pentium 5 / WinChip machine checks" 1140 depends on X86_32 && X86_MCE 1141 ---help--- 1142 Include support for machine check handling on old Pentium 5 or WinChip 1143 systems. These typically need to be enabled explicitly on the command 1144 line. 1145 1146config X86_MCE_THRESHOLD 1147 depends on X86_MCE_AMD || X86_MCE_INTEL 1148 def_bool y 1149 1150config X86_MCE_INJECT 1151 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1152 tristate "Machine check injector support" 1153 ---help--- 1154 Provide support for injecting machine checks for testing purposes. 1155 If you don't know what a machine check is and you don't do kernel 1156 QA it is safe to say n. 1157 1158config X86_THERMAL_VECTOR 1159 def_bool y 1160 depends on X86_MCE_INTEL 1161 1162source "arch/x86/events/Kconfig" 1163 1164config X86_LEGACY_VM86 1165 bool "Legacy VM86 support" 1166 depends on X86_32 1167 ---help--- 1168 This option allows user programs to put the CPU into V8086 1169 mode, which is an 80286-era approximation of 16-bit real mode. 1170 1171 Some very old versions of X and/or vbetool require this option 1172 for user mode setting. Similarly, DOSEMU will use it if 1173 available to accelerate real mode DOS programs. However, any 1174 recent version of DOSEMU, X, or vbetool should be fully 1175 functional even without kernel VM86 support, as they will all 1176 fall back to software emulation. Nevertheless, if you are using 1177 a 16-bit DOS program where 16-bit performance matters, vm86 1178 mode might be faster than emulation and you might want to 1179 enable this option. 1180 1181 Note that any app that works on a 64-bit kernel is unlikely to 1182 need this option, as 64-bit kernels don't, and can't, support 1183 V8086 mode. This option is also unrelated to 16-bit protected 1184 mode and is not needed to run most 16-bit programs under Wine. 1185 1186 Enabling this option increases the complexity of the kernel 1187 and slows down exception handling a tiny bit. 1188 1189 If unsure, say N here. 1190 1191config VM86 1192 bool 1193 default X86_LEGACY_VM86 1194 1195config X86_16BIT 1196 bool "Enable support for 16-bit segments" if EXPERT 1197 default y 1198 depends on MODIFY_LDT_SYSCALL 1199 ---help--- 1200 This option is required by programs like Wine to run 16-bit 1201 protected mode legacy code on x86 processors. Disabling 1202 this option saves about 300 bytes on i386, or around 6K text 1203 plus 16K runtime memory on x86-64, 1204 1205config X86_ESPFIX32 1206 def_bool y 1207 depends on X86_16BIT && X86_32 1208 1209config X86_ESPFIX64 1210 def_bool y 1211 depends on X86_16BIT && X86_64 1212 1213config X86_VSYSCALL_EMULATION 1214 bool "Enable vsyscall emulation" if EXPERT 1215 default y 1216 depends on X86_64 1217 ---help--- 1218 This enables emulation of the legacy vsyscall page. Disabling 1219 it is roughly equivalent to booting with vsyscall=none, except 1220 that it will also disable the helpful warning if a program 1221 tries to use a vsyscall. With this option set to N, offending 1222 programs will just segfault, citing addresses of the form 1223 0xffffffffff600?00. 1224 1225 This option is required by many programs built before 2013, and 1226 care should be used even with newer programs if set to N. 1227 1228 Disabling this option saves about 7K of kernel size and 1229 possibly 4K of additional runtime pagetable memory. 1230 1231config X86_IOPL_IOPERM 1232 bool "IOPERM and IOPL Emulation" 1233 default y 1234 ---help--- 1235 This enables the ioperm() and iopl() syscalls which are necessary 1236 for legacy applications. 1237 1238 Legacy IOPL support is an overbroad mechanism which allows user 1239 space aside of accessing all 65536 I/O ports also to disable 1240 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1241 capabilities and permission from potentially active security 1242 modules. 1243 1244 The emulation restricts the functionality of the syscall to 1245 only allowing the full range I/O port access, but prevents the 1246 ability to disable interrupts from user space which would be 1247 granted if the hardware IOPL mechanism would be used. 1248 1249config TOSHIBA 1250 tristate "Toshiba Laptop support" 1251 depends on X86_32 1252 ---help--- 1253 This adds a driver to safely access the System Management Mode of 1254 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1255 not work on models with a Phoenix BIOS. The System Management Mode 1256 is used to set the BIOS and power saving options on Toshiba portables. 1257 1258 For information on utilities to make use of this driver see the 1259 Toshiba Linux utilities web site at: 1260 <http://www.buzzard.org.uk/toshiba/>. 1261 1262 Say Y if you intend to run this kernel on a Toshiba portable. 1263 Say N otherwise. 1264 1265config I8K 1266 tristate "Dell i8k legacy laptop support" 1267 select HWMON 1268 select SENSORS_DELL_SMM 1269 ---help--- 1270 This option enables legacy /proc/i8k userspace interface in hwmon 1271 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1272 temperature and allows controlling fan speeds of Dell laptops via 1273 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1274 it reports also power and hotkey status. For fan speed control is 1275 needed userspace package i8kutils. 1276 1277 Say Y if you intend to run this kernel on old Dell laptops or want to 1278 use userspace package i8kutils. 1279 Say N otherwise. 1280 1281config X86_REBOOTFIXUPS 1282 bool "Enable X86 board specific fixups for reboot" 1283 depends on X86_32 1284 ---help--- 1285 This enables chipset and/or board specific fixups to be done 1286 in order to get reboot to work correctly. This is only needed on 1287 some combinations of hardware and BIOS. The symptom, for which 1288 this config is intended, is when reboot ends with a stalled/hung 1289 system. 1290 1291 Currently, the only fixup is for the Geode machines using 1292 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1293 1294 Say Y if you want to enable the fixup. Currently, it's safe to 1295 enable this option even if you don't need it. 1296 Say N otherwise. 1297 1298config MICROCODE 1299 bool "CPU microcode loading support" 1300 default y 1301 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1302 select FW_LOADER 1303 ---help--- 1304 If you say Y here, you will be able to update the microcode on 1305 Intel and AMD processors. The Intel support is for the IA32 family, 1306 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1307 AMD support is for families 0x10 and later. You will obviously need 1308 the actual microcode binary data itself which is not shipped with 1309 the Linux kernel. 1310 1311 The preferred method to load microcode from a detached initrd is described 1312 in Documentation/x86/microcode.rst. For that you need to enable 1313 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1314 initrd for microcode blobs. 1315 1316 In addition, you can build the microcode into the kernel. For that you 1317 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1318 config option. 1319 1320config MICROCODE_INTEL 1321 bool "Intel microcode loading support" 1322 depends on MICROCODE 1323 default MICROCODE 1324 select FW_LOADER 1325 ---help--- 1326 This options enables microcode patch loading support for Intel 1327 processors. 1328 1329 For the current Intel microcode data package go to 1330 <https://downloadcenter.intel.com> and search for 1331 'Linux Processor Microcode Data File'. 1332 1333config MICROCODE_AMD 1334 bool "AMD microcode loading support" 1335 depends on MICROCODE 1336 select FW_LOADER 1337 ---help--- 1338 If you select this option, microcode patch loading support for AMD 1339 processors will be enabled. 1340 1341config MICROCODE_OLD_INTERFACE 1342 bool "Ancient loading interface (DEPRECATED)" 1343 default n 1344 depends on MICROCODE 1345 ---help--- 1346 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1347 which was used by userspace tools like iucode_tool and microcode.ctl. 1348 It is inadequate because it runs too late to be able to properly 1349 load microcode on a machine and it needs special tools. Instead, you 1350 should've switched to the early loading method with the initrd or 1351 builtin microcode by now: Documentation/x86/microcode.rst 1352 1353config X86_MSR 1354 tristate "/dev/cpu/*/msr - Model-specific register support" 1355 ---help--- 1356 This device gives privileged processes access to the x86 1357 Model-Specific Registers (MSRs). It is a character device with 1358 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1359 MSR accesses are directed to a specific CPU on multi-processor 1360 systems. 1361 1362config X86_CPUID 1363 tristate "/dev/cpu/*/cpuid - CPU information support" 1364 ---help--- 1365 This device gives processes access to the x86 CPUID instruction to 1366 be executed on a specific processor. It is a character device 1367 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1368 /dev/cpu/31/cpuid. 1369 1370choice 1371 prompt "High Memory Support" 1372 default HIGHMEM4G 1373 depends on X86_32 1374 1375config NOHIGHMEM 1376 bool "off" 1377 ---help--- 1378 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1379 However, the address space of 32-bit x86 processors is only 4 1380 Gigabytes large. That means that, if you have a large amount of 1381 physical memory, not all of it can be "permanently mapped" by the 1382 kernel. The physical memory that's not permanently mapped is called 1383 "high memory". 1384 1385 If you are compiling a kernel which will never run on a machine with 1386 more than 1 Gigabyte total physical RAM, answer "off" here (default 1387 choice and suitable for most users). This will result in a "3GB/1GB" 1388 split: 3GB are mapped so that each process sees a 3GB virtual memory 1389 space and the remaining part of the 4GB virtual memory space is used 1390 by the kernel to permanently map as much physical memory as 1391 possible. 1392 1393 If the machine has between 1 and 4 Gigabytes physical RAM, then 1394 answer "4GB" here. 1395 1396 If more than 4 Gigabytes is used then answer "64GB" here. This 1397 selection turns Intel PAE (Physical Address Extension) mode on. 1398 PAE implements 3-level paging on IA32 processors. PAE is fully 1399 supported by Linux, PAE mode is implemented on all recent Intel 1400 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1401 then the kernel will not boot on CPUs that don't support PAE! 1402 1403 The actual amount of total physical memory will either be 1404 auto detected or can be forced by using a kernel command line option 1405 such as "mem=256M". (Try "man bootparam" or see the documentation of 1406 your boot loader (lilo or loadlin) about how to pass options to the 1407 kernel at boot time.) 1408 1409 If unsure, say "off". 1410 1411config HIGHMEM4G 1412 bool "4GB" 1413 ---help--- 1414 Select this if you have a 32-bit processor and between 1 and 4 1415 gigabytes of physical RAM. 1416 1417config HIGHMEM64G 1418 bool "64GB" 1419 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1420 select X86_PAE 1421 ---help--- 1422 Select this if you have a 32-bit processor and more than 4 1423 gigabytes of physical RAM. 1424 1425endchoice 1426 1427choice 1428 prompt "Memory split" if EXPERT 1429 default VMSPLIT_3G 1430 depends on X86_32 1431 ---help--- 1432 Select the desired split between kernel and user memory. 1433 1434 If the address range available to the kernel is less than the 1435 physical memory installed, the remaining memory will be available 1436 as "high memory". Accessing high memory is a little more costly 1437 than low memory, as it needs to be mapped into the kernel first. 1438 Note that increasing the kernel address space limits the range 1439 available to user programs, making the address space there 1440 tighter. Selecting anything other than the default 3G/1G split 1441 will also likely make your kernel incompatible with binary-only 1442 kernel modules. 1443 1444 If you are not absolutely sure what you are doing, leave this 1445 option alone! 1446 1447 config VMSPLIT_3G 1448 bool "3G/1G user/kernel split" 1449 config VMSPLIT_3G_OPT 1450 depends on !X86_PAE 1451 bool "3G/1G user/kernel split (for full 1G low memory)" 1452 config VMSPLIT_2G 1453 bool "2G/2G user/kernel split" 1454 config VMSPLIT_2G_OPT 1455 depends on !X86_PAE 1456 bool "2G/2G user/kernel split (for full 2G low memory)" 1457 config VMSPLIT_1G 1458 bool "1G/3G user/kernel split" 1459endchoice 1460 1461config PAGE_OFFSET 1462 hex 1463 default 0xB0000000 if VMSPLIT_3G_OPT 1464 default 0x80000000 if VMSPLIT_2G 1465 default 0x78000000 if VMSPLIT_2G_OPT 1466 default 0x40000000 if VMSPLIT_1G 1467 default 0xC0000000 1468 depends on X86_32 1469 1470config HIGHMEM 1471 def_bool y 1472 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1473 1474config X86_PAE 1475 bool "PAE (Physical Address Extension) Support" 1476 depends on X86_32 && !HIGHMEM4G 1477 select PHYS_ADDR_T_64BIT 1478 select SWIOTLB 1479 ---help--- 1480 PAE is required for NX support, and furthermore enables 1481 larger swapspace support for non-overcommit purposes. It 1482 has the cost of more pagetable lookup overhead, and also 1483 consumes more pagetable space per process. 1484 1485config X86_5LEVEL 1486 bool "Enable 5-level page tables support" 1487 default y 1488 select DYNAMIC_MEMORY_LAYOUT 1489 select SPARSEMEM_VMEMMAP 1490 depends on X86_64 1491 ---help--- 1492 5-level paging enables access to larger address space: 1493 upto 128 PiB of virtual address space and 4 PiB of 1494 physical address space. 1495 1496 It will be supported by future Intel CPUs. 1497 1498 A kernel with the option enabled can be booted on machines that 1499 support 4- or 5-level paging. 1500 1501 See Documentation/x86/x86_64/5level-paging.rst for more 1502 information. 1503 1504 Say N if unsure. 1505 1506config X86_DIRECT_GBPAGES 1507 def_bool y 1508 depends on X86_64 1509 ---help--- 1510 Certain kernel features effectively disable kernel 1511 linear 1 GB mappings (even if the CPU otherwise 1512 supports them), so don't confuse the user by printing 1513 that we have them enabled. 1514 1515config X86_CPA_STATISTICS 1516 bool "Enable statistic for Change Page Attribute" 1517 depends on DEBUG_FS 1518 ---help--- 1519 Expose statistics about the Change Page Attribute mechanism, which 1520 helps to determine the effectiveness of preserving large and huge 1521 page mappings when mapping protections are changed. 1522 1523config AMD_MEM_ENCRYPT 1524 bool "AMD Secure Memory Encryption (SME) support" 1525 depends on X86_64 && CPU_SUP_AMD 1526 select DYNAMIC_PHYSICAL_MASK 1527 select ARCH_USE_MEMREMAP_PROT 1528 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1529 ---help--- 1530 Say yes to enable support for the encryption of system memory. 1531 This requires an AMD processor that supports Secure Memory 1532 Encryption (SME). 1533 1534config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1535 bool "Activate AMD Secure Memory Encryption (SME) by default" 1536 default y 1537 depends on AMD_MEM_ENCRYPT 1538 ---help--- 1539 Say yes to have system memory encrypted by default if running on 1540 an AMD processor that supports Secure Memory Encryption (SME). 1541 1542 If set to Y, then the encryption of system memory can be 1543 deactivated with the mem_encrypt=off command line option. 1544 1545 If set to N, then the encryption of system memory can be 1546 activated with the mem_encrypt=on command line option. 1547 1548# Common NUMA Features 1549config NUMA 1550 bool "NUMA Memory Allocation and Scheduler Support" 1551 depends on SMP 1552 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1553 default y if X86_BIGSMP 1554 ---help--- 1555 Enable NUMA (Non-Uniform Memory Access) support. 1556 1557 The kernel will try to allocate memory used by a CPU on the 1558 local memory controller of the CPU and add some more 1559 NUMA awareness to the kernel. 1560 1561 For 64-bit this is recommended if the system is Intel Core i7 1562 (or later), AMD Opteron, or EM64T NUMA. 1563 1564 For 32-bit this is only needed if you boot a 32-bit 1565 kernel on a 64-bit NUMA platform. 1566 1567 Otherwise, you should say N. 1568 1569config AMD_NUMA 1570 def_bool y 1571 prompt "Old style AMD Opteron NUMA detection" 1572 depends on X86_64 && NUMA && PCI 1573 ---help--- 1574 Enable AMD NUMA node topology detection. You should say Y here if 1575 you have a multi processor AMD system. This uses an old method to 1576 read the NUMA configuration directly from the builtin Northbridge 1577 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1578 which also takes priority if both are compiled in. 1579 1580config X86_64_ACPI_NUMA 1581 def_bool y 1582 prompt "ACPI NUMA detection" 1583 depends on X86_64 && NUMA && ACPI && PCI 1584 select ACPI_NUMA 1585 ---help--- 1586 Enable ACPI SRAT based node topology detection. 1587 1588# Some NUMA nodes have memory ranges that span 1589# other nodes. Even though a pfn is valid and 1590# between a node's start and end pfns, it may not 1591# reside on that node. See memmap_init_zone() 1592# for details. 1593config NODES_SPAN_OTHER_NODES 1594 def_bool y 1595 depends on X86_64_ACPI_NUMA 1596 1597config NUMA_EMU 1598 bool "NUMA emulation" 1599 depends on NUMA 1600 ---help--- 1601 Enable NUMA emulation. A flat machine will be split 1602 into virtual nodes when booted with "numa=fake=N", where N is the 1603 number of nodes. This is only useful for debugging. 1604 1605config NODES_SHIFT 1606 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1607 range 1 10 1608 default "10" if MAXSMP 1609 default "6" if X86_64 1610 default "3" 1611 depends on NEED_MULTIPLE_NODES 1612 ---help--- 1613 Specify the maximum number of NUMA Nodes available on the target 1614 system. Increases memory reserved to accommodate various tables. 1615 1616config ARCH_HAVE_MEMORY_PRESENT 1617 def_bool y 1618 depends on X86_32 && DISCONTIGMEM 1619 1620config ARCH_FLATMEM_ENABLE 1621 def_bool y 1622 depends on X86_32 && !NUMA 1623 1624config ARCH_DISCONTIGMEM_ENABLE 1625 def_bool n 1626 depends on NUMA && X86_32 1627 depends on BROKEN 1628 1629config ARCH_SPARSEMEM_ENABLE 1630 def_bool y 1631 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1632 select SPARSEMEM_STATIC if X86_32 1633 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1634 1635config ARCH_SPARSEMEM_DEFAULT 1636 def_bool X86_64 || (NUMA && X86_32) 1637 1638config ARCH_SELECT_MEMORY_MODEL 1639 def_bool y 1640 depends on ARCH_SPARSEMEM_ENABLE 1641 1642config ARCH_MEMORY_PROBE 1643 bool "Enable sysfs memory/probe interface" 1644 depends on X86_64 && MEMORY_HOTPLUG 1645 help 1646 This option enables a sysfs memory/probe interface for testing. 1647 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1648 If you are unsure how to answer this question, answer N. 1649 1650config ARCH_PROC_KCORE_TEXT 1651 def_bool y 1652 depends on X86_64 && PROC_KCORE 1653 1654config ILLEGAL_POINTER_VALUE 1655 hex 1656 default 0 if X86_32 1657 default 0xdead000000000000 if X86_64 1658 1659config X86_PMEM_LEGACY_DEVICE 1660 bool 1661 1662config X86_PMEM_LEGACY 1663 tristate "Support non-standard NVDIMMs and ADR protected memory" 1664 depends on PHYS_ADDR_T_64BIT 1665 depends on BLK_DEV 1666 select X86_PMEM_LEGACY_DEVICE 1667 select LIBNVDIMM 1668 help 1669 Treat memory marked using the non-standard e820 type of 12 as used 1670 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1671 The kernel will offer these regions to the 'pmem' driver so 1672 they can be used for persistent storage. 1673 1674 Say Y if unsure. 1675 1676config HIGHPTE 1677 bool "Allocate 3rd-level pagetables from highmem" 1678 depends on HIGHMEM 1679 ---help--- 1680 The VM uses one page table entry for each page of physical memory. 1681 For systems with a lot of RAM, this can be wasteful of precious 1682 low memory. Setting this option will put user-space page table 1683 entries in high memory. 1684 1685config X86_CHECK_BIOS_CORRUPTION 1686 bool "Check for low memory corruption" 1687 ---help--- 1688 Periodically check for memory corruption in low memory, which 1689 is suspected to be caused by BIOS. Even when enabled in the 1690 configuration, it is disabled at runtime. Enable it by 1691 setting "memory_corruption_check=1" on the kernel command 1692 line. By default it scans the low 64k of memory every 60 1693 seconds; see the memory_corruption_check_size and 1694 memory_corruption_check_period parameters in 1695 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1696 1697 When enabled with the default parameters, this option has 1698 almost no overhead, as it reserves a relatively small amount 1699 of memory and scans it infrequently. It both detects corruption 1700 and prevents it from affecting the running system. 1701 1702 It is, however, intended as a diagnostic tool; if repeatable 1703 BIOS-originated corruption always affects the same memory, 1704 you can use memmap= to prevent the kernel from using that 1705 memory. 1706 1707config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1708 bool "Set the default setting of memory_corruption_check" 1709 depends on X86_CHECK_BIOS_CORRUPTION 1710 default y 1711 ---help--- 1712 Set whether the default state of memory_corruption_check is 1713 on or off. 1714 1715config X86_RESERVE_LOW 1716 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1717 default 64 1718 range 4 640 1719 ---help--- 1720 Specify the amount of low memory to reserve for the BIOS. 1721 1722 The first page contains BIOS data structures that the kernel 1723 must not use, so that page must always be reserved. 1724 1725 By default we reserve the first 64K of physical RAM, as a 1726 number of BIOSes are known to corrupt that memory range 1727 during events such as suspend/resume or monitor cable 1728 insertion, so it must not be used by the kernel. 1729 1730 You can set this to 4 if you are absolutely sure that you 1731 trust the BIOS to get all its memory reservations and usages 1732 right. If you know your BIOS have problems beyond the 1733 default 64K area, you can set this to 640 to avoid using the 1734 entire low memory range. 1735 1736 If you have doubts about the BIOS (e.g. suspend/resume does 1737 not work or there's kernel crashes after certain hardware 1738 hotplug events) then you might want to enable 1739 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1740 typical corruption patterns. 1741 1742 Leave this to the default value of 64 if you are unsure. 1743 1744config MATH_EMULATION 1745 bool 1746 depends on MODIFY_LDT_SYSCALL 1747 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1748 ---help--- 1749 Linux can emulate a math coprocessor (used for floating point 1750 operations) if you don't have one. 486DX and Pentium processors have 1751 a math coprocessor built in, 486SX and 386 do not, unless you added 1752 a 487DX or 387, respectively. (The messages during boot time can 1753 give you some hints here ["man dmesg"].) Everyone needs either a 1754 coprocessor or this emulation. 1755 1756 If you don't have a math coprocessor, you need to say Y here; if you 1757 say Y here even though you have a coprocessor, the coprocessor will 1758 be used nevertheless. (This behavior can be changed with the kernel 1759 command line option "no387", which comes handy if your coprocessor 1760 is broken. Try "man bootparam" or see the documentation of your boot 1761 loader (lilo or loadlin) about how to pass options to the kernel at 1762 boot time.) This means that it is a good idea to say Y here if you 1763 intend to use this kernel on different machines. 1764 1765 More information about the internals of the Linux math coprocessor 1766 emulation can be found in <file:arch/x86/math-emu/README>. 1767 1768 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1769 kernel, it won't hurt. 1770 1771config MTRR 1772 def_bool y 1773 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1774 ---help--- 1775 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1776 the Memory Type Range Registers (MTRRs) may be used to control 1777 processor access to memory ranges. This is most useful if you have 1778 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1779 allows bus write transfers to be combined into a larger transfer 1780 before bursting over the PCI/AGP bus. This can increase performance 1781 of image write operations 2.5 times or more. Saying Y here creates a 1782 /proc/mtrr file which may be used to manipulate your processor's 1783 MTRRs. Typically the X server should use this. 1784 1785 This code has a reasonably generic interface so that similar 1786 control registers on other processors can be easily supported 1787 as well: 1788 1789 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1790 Registers (ARRs) which provide a similar functionality to MTRRs. For 1791 these, the ARRs are used to emulate the MTRRs. 1792 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1793 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1794 write-combining. All of these processors are supported by this code 1795 and it makes sense to say Y here if you have one of them. 1796 1797 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1798 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1799 can lead to all sorts of problems, so it's good to say Y here. 1800 1801 You can safely say Y even if your machine doesn't have MTRRs, you'll 1802 just add about 9 KB to your kernel. 1803 1804 See <file:Documentation/x86/mtrr.rst> for more information. 1805 1806config MTRR_SANITIZER 1807 def_bool y 1808 prompt "MTRR cleanup support" 1809 depends on MTRR 1810 ---help--- 1811 Convert MTRR layout from continuous to discrete, so X drivers can 1812 add writeback entries. 1813 1814 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1815 The largest mtrr entry size for a continuous block can be set with 1816 mtrr_chunk_size. 1817 1818 If unsure, say Y. 1819 1820config MTRR_SANITIZER_ENABLE_DEFAULT 1821 int "MTRR cleanup enable value (0-1)" 1822 range 0 1 1823 default "0" 1824 depends on MTRR_SANITIZER 1825 ---help--- 1826 Enable mtrr cleanup default value 1827 1828config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1829 int "MTRR cleanup spare reg num (0-7)" 1830 range 0 7 1831 default "1" 1832 depends on MTRR_SANITIZER 1833 ---help--- 1834 mtrr cleanup spare entries default, it can be changed via 1835 mtrr_spare_reg_nr=N on the kernel command line. 1836 1837config X86_PAT 1838 def_bool y 1839 prompt "x86 PAT support" if EXPERT 1840 depends on MTRR 1841 ---help--- 1842 Use PAT attributes to setup page level cache control. 1843 1844 PATs are the modern equivalents of MTRRs and are much more 1845 flexible than MTRRs. 1846 1847 Say N here if you see bootup problems (boot crash, boot hang, 1848 spontaneous reboots) or a non-working video driver. 1849 1850 If unsure, say Y. 1851 1852config ARCH_USES_PG_UNCACHED 1853 def_bool y 1854 depends on X86_PAT 1855 1856config ARCH_RANDOM 1857 def_bool y 1858 prompt "x86 architectural random number generator" if EXPERT 1859 ---help--- 1860 Enable the x86 architectural RDRAND instruction 1861 (Intel Bull Mountain technology) to generate random numbers. 1862 If supported, this is a high bandwidth, cryptographically 1863 secure hardware random number generator. 1864 1865config X86_SMAP 1866 def_bool y 1867 prompt "Supervisor Mode Access Prevention" if EXPERT 1868 ---help--- 1869 Supervisor Mode Access Prevention (SMAP) is a security 1870 feature in newer Intel processors. There is a small 1871 performance cost if this enabled and turned on; there is 1872 also a small increase in the kernel size if this is enabled. 1873 1874 If unsure, say Y. 1875 1876config X86_UMIP 1877 def_bool y 1878 depends on CPU_SUP_INTEL || CPU_SUP_AMD 1879 prompt "User Mode Instruction Prevention" if EXPERT 1880 ---help--- 1881 User Mode Instruction Prevention (UMIP) is a security feature in 1882 some x86 processors. If enabled, a general protection fault is 1883 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1884 executed in user mode. These instructions unnecessarily expose 1885 information about the hardware state. 1886 1887 The vast majority of applications do not use these instructions. 1888 For the very few that do, software emulation is provided in 1889 specific cases in protected and virtual-8086 modes. Emulated 1890 results are dummy. 1891 1892config X86_INTEL_MEMORY_PROTECTION_KEYS 1893 prompt "Intel Memory Protection Keys" 1894 def_bool y 1895 # Note: only available in 64-bit mode 1896 depends on CPU_SUP_INTEL && X86_64 1897 select ARCH_USES_HIGH_VMA_FLAGS 1898 select ARCH_HAS_PKEYS 1899 ---help--- 1900 Memory Protection Keys provides a mechanism for enforcing 1901 page-based protections, but without requiring modification of the 1902 page tables when an application changes protection domains. 1903 1904 For details, see Documentation/core-api/protection-keys.rst 1905 1906 If unsure, say y. 1907 1908choice 1909 prompt "TSX enable mode" 1910 depends on CPU_SUP_INTEL 1911 default X86_INTEL_TSX_MODE_OFF 1912 help 1913 Intel's TSX (Transactional Synchronization Extensions) feature 1914 allows to optimize locking protocols through lock elision which 1915 can lead to a noticeable performance boost. 1916 1917 On the other hand it has been shown that TSX can be exploited 1918 to form side channel attacks (e.g. TAA) and chances are there 1919 will be more of those attacks discovered in the future. 1920 1921 Therefore TSX is not enabled by default (aka tsx=off). An admin 1922 might override this decision by tsx=on the command line parameter. 1923 Even with TSX enabled, the kernel will attempt to enable the best 1924 possible TAA mitigation setting depending on the microcode available 1925 for the particular machine. 1926 1927 This option allows to set the default tsx mode between tsx=on, =off 1928 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1929 details. 1930 1931 Say off if not sure, auto if TSX is in use but it should be used on safe 1932 platforms or on if TSX is in use and the security aspect of tsx is not 1933 relevant. 1934 1935config X86_INTEL_TSX_MODE_OFF 1936 bool "off" 1937 help 1938 TSX is disabled if possible - equals to tsx=off command line parameter. 1939 1940config X86_INTEL_TSX_MODE_ON 1941 bool "on" 1942 help 1943 TSX is always enabled on TSX capable HW - equals the tsx=on command 1944 line parameter. 1945 1946config X86_INTEL_TSX_MODE_AUTO 1947 bool "auto" 1948 help 1949 TSX is enabled on TSX capable HW that is believed to be safe against 1950 side channel attacks- equals the tsx=auto command line parameter. 1951endchoice 1952 1953config EFI 1954 bool "EFI runtime service support" 1955 depends on ACPI 1956 select UCS2_STRING 1957 select EFI_RUNTIME_WRAPPERS 1958 ---help--- 1959 This enables the kernel to use EFI runtime services that are 1960 available (such as the EFI variable services). 1961 1962 This option is only useful on systems that have EFI firmware. 1963 In addition, you should use the latest ELILO loader available 1964 at <http://elilo.sourceforge.net> in order to take advantage 1965 of EFI runtime services. However, even with this option, the 1966 resultant kernel should continue to boot on existing non-EFI 1967 platforms. 1968 1969config EFI_STUB 1970 bool "EFI stub support" 1971 depends on EFI && !X86_USE_3DNOW 1972 depends on $(cc-option,-mabi=ms) || X86_32 1973 select RELOCATABLE 1974 ---help--- 1975 This kernel feature allows a bzImage to be loaded directly 1976 by EFI firmware without the use of a bootloader. 1977 1978 See Documentation/admin-guide/efi-stub.rst for more information. 1979 1980config EFI_MIXED 1981 bool "EFI mixed-mode support" 1982 depends on EFI_STUB && X86_64 1983 ---help--- 1984 Enabling this feature allows a 64-bit kernel to be booted 1985 on a 32-bit firmware, provided that your CPU supports 64-bit 1986 mode. 1987 1988 Note that it is not possible to boot a mixed-mode enabled 1989 kernel via the EFI boot stub - a bootloader that supports 1990 the EFI handover protocol must be used. 1991 1992 If unsure, say N. 1993 1994config SECCOMP 1995 def_bool y 1996 prompt "Enable seccomp to safely compute untrusted bytecode" 1997 ---help--- 1998 This kernel feature is useful for number crunching applications 1999 that may need to compute untrusted bytecode during their 2000 execution. By using pipes or other transports made available to 2001 the process as file descriptors supporting the read/write 2002 syscalls, it's possible to isolate those applications in 2003 their own address space using seccomp. Once seccomp is 2004 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 2005 and the task is only allowed to execute a few safe syscalls 2006 defined by each seccomp mode. 2007 2008 If unsure, say Y. Only embedded should say N here. 2009 2010source "kernel/Kconfig.hz" 2011 2012config KEXEC 2013 bool "kexec system call" 2014 select KEXEC_CORE 2015 ---help--- 2016 kexec is a system call that implements the ability to shutdown your 2017 current kernel, and to start another kernel. It is like a reboot 2018 but it is independent of the system firmware. And like a reboot 2019 you can start any kernel with it, not just Linux. 2020 2021 The name comes from the similarity to the exec system call. 2022 2023 It is an ongoing process to be certain the hardware in a machine 2024 is properly shutdown, so do not be surprised if this code does not 2025 initially work for you. As of this writing the exact hardware 2026 interface is strongly in flux, so no good recommendation can be 2027 made. 2028 2029config KEXEC_FILE 2030 bool "kexec file based system call" 2031 select KEXEC_CORE 2032 select BUILD_BIN2C 2033 depends on X86_64 2034 depends on CRYPTO=y 2035 depends on CRYPTO_SHA256=y 2036 ---help--- 2037 This is new version of kexec system call. This system call is 2038 file based and takes file descriptors as system call argument 2039 for kernel and initramfs as opposed to list of segments as 2040 accepted by previous system call. 2041 2042config ARCH_HAS_KEXEC_PURGATORY 2043 def_bool KEXEC_FILE 2044 2045config KEXEC_SIG 2046 bool "Verify kernel signature during kexec_file_load() syscall" 2047 depends on KEXEC_FILE 2048 ---help--- 2049 2050 This option makes the kexec_file_load() syscall check for a valid 2051 signature of the kernel image. The image can still be loaded without 2052 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2053 there's a signature that we can check, then it must be valid. 2054 2055 In addition to this option, you need to enable signature 2056 verification for the corresponding kernel image type being 2057 loaded in order for this to work. 2058 2059config KEXEC_SIG_FORCE 2060 bool "Require a valid signature in kexec_file_load() syscall" 2061 depends on KEXEC_SIG 2062 ---help--- 2063 This option makes kernel signature verification mandatory for 2064 the kexec_file_load() syscall. 2065 2066config KEXEC_BZIMAGE_VERIFY_SIG 2067 bool "Enable bzImage signature verification support" 2068 depends on KEXEC_SIG 2069 depends on SIGNED_PE_FILE_VERIFICATION 2070 select SYSTEM_TRUSTED_KEYRING 2071 ---help--- 2072 Enable bzImage signature verification support. 2073 2074config CRASH_DUMP 2075 bool "kernel crash dumps" 2076 depends on X86_64 || (X86_32 && HIGHMEM) 2077 ---help--- 2078 Generate crash dump after being started by kexec. 2079 This should be normally only set in special crash dump kernels 2080 which are loaded in the main kernel with kexec-tools into 2081 a specially reserved region and then later executed after 2082 a crash by kdump/kexec. The crash dump kernel must be compiled 2083 to a memory address not used by the main kernel or BIOS using 2084 PHYSICAL_START, or it must be built as a relocatable image 2085 (CONFIG_RELOCATABLE=y). 2086 For more details see Documentation/admin-guide/kdump/kdump.rst 2087 2088config KEXEC_JUMP 2089 bool "kexec jump" 2090 depends on KEXEC && HIBERNATION 2091 ---help--- 2092 Jump between original kernel and kexeced kernel and invoke 2093 code in physical address mode via KEXEC 2094 2095config PHYSICAL_START 2096 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2097 default "0x1000000" 2098 ---help--- 2099 This gives the physical address where the kernel is loaded. 2100 2101 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2102 bzImage will decompress itself to above physical address and 2103 run from there. Otherwise, bzImage will run from the address where 2104 it has been loaded by the boot loader and will ignore above physical 2105 address. 2106 2107 In normal kdump cases one does not have to set/change this option 2108 as now bzImage can be compiled as a completely relocatable image 2109 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2110 address. This option is mainly useful for the folks who don't want 2111 to use a bzImage for capturing the crash dump and want to use a 2112 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2113 to be specifically compiled to run from a specific memory area 2114 (normally a reserved region) and this option comes handy. 2115 2116 So if you are using bzImage for capturing the crash dump, 2117 leave the value here unchanged to 0x1000000 and set 2118 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2119 for capturing the crash dump change this value to start of 2120 the reserved region. In other words, it can be set based on 2121 the "X" value as specified in the "crashkernel=YM@XM" 2122 command line boot parameter passed to the panic-ed 2123 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2124 for more details about crash dumps. 2125 2126 Usage of bzImage for capturing the crash dump is recommended as 2127 one does not have to build two kernels. Same kernel can be used 2128 as production kernel and capture kernel. Above option should have 2129 gone away after relocatable bzImage support is introduced. But it 2130 is present because there are users out there who continue to use 2131 vmlinux for dump capture. This option should go away down the 2132 line. 2133 2134 Don't change this unless you know what you are doing. 2135 2136config RELOCATABLE 2137 bool "Build a relocatable kernel" 2138 default y 2139 ---help--- 2140 This builds a kernel image that retains relocation information 2141 so it can be loaded someplace besides the default 1MB. 2142 The relocations tend to make the kernel binary about 10% larger, 2143 but are discarded at runtime. 2144 2145 One use is for the kexec on panic case where the recovery kernel 2146 must live at a different physical address than the primary 2147 kernel. 2148 2149 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2150 it has been loaded at and the compile time physical address 2151 (CONFIG_PHYSICAL_START) is used as the minimum location. 2152 2153config RANDOMIZE_BASE 2154 bool "Randomize the address of the kernel image (KASLR)" 2155 depends on RELOCATABLE 2156 default y 2157 ---help--- 2158 In support of Kernel Address Space Layout Randomization (KASLR), 2159 this randomizes the physical address at which the kernel image 2160 is decompressed and the virtual address where the kernel 2161 image is mapped, as a security feature that deters exploit 2162 attempts relying on knowledge of the location of kernel 2163 code internals. 2164 2165 On 64-bit, the kernel physical and virtual addresses are 2166 randomized separately. The physical address will be anywhere 2167 between 16MB and the top of physical memory (up to 64TB). The 2168 virtual address will be randomized from 16MB up to 1GB (9 bits 2169 of entropy). Note that this also reduces the memory space 2170 available to kernel modules from 1.5GB to 1GB. 2171 2172 On 32-bit, the kernel physical and virtual addresses are 2173 randomized together. They will be randomized from 16MB up to 2174 512MB (8 bits of entropy). 2175 2176 Entropy is generated using the RDRAND instruction if it is 2177 supported. If RDTSC is supported, its value is mixed into 2178 the entropy pool as well. If neither RDRAND nor RDTSC are 2179 supported, then entropy is read from the i8254 timer. The 2180 usable entropy is limited by the kernel being built using 2181 2GB addressing, and that PHYSICAL_ALIGN must be at a 2182 minimum of 2MB. As a result, only 10 bits of entropy are 2183 theoretically possible, but the implementations are further 2184 limited due to memory layouts. 2185 2186 If unsure, say Y. 2187 2188# Relocation on x86 needs some additional build support 2189config X86_NEED_RELOCS 2190 def_bool y 2191 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2192 2193config PHYSICAL_ALIGN 2194 hex "Alignment value to which kernel should be aligned" 2195 default "0x200000" 2196 range 0x2000 0x1000000 if X86_32 2197 range 0x200000 0x1000000 if X86_64 2198 ---help--- 2199 This value puts the alignment restrictions on physical address 2200 where kernel is loaded and run from. Kernel is compiled for an 2201 address which meets above alignment restriction. 2202 2203 If bootloader loads the kernel at a non-aligned address and 2204 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2205 address aligned to above value and run from there. 2206 2207 If bootloader loads the kernel at a non-aligned address and 2208 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2209 load address and decompress itself to the address it has been 2210 compiled for and run from there. The address for which kernel is 2211 compiled already meets above alignment restrictions. Hence the 2212 end result is that kernel runs from a physical address meeting 2213 above alignment restrictions. 2214 2215 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2216 this value must be a multiple of 0x200000. 2217 2218 Don't change this unless you know what you are doing. 2219 2220config DYNAMIC_MEMORY_LAYOUT 2221 bool 2222 ---help--- 2223 This option makes base addresses of vmalloc and vmemmap as well as 2224 __PAGE_OFFSET movable during boot. 2225 2226config RANDOMIZE_MEMORY 2227 bool "Randomize the kernel memory sections" 2228 depends on X86_64 2229 depends on RANDOMIZE_BASE 2230 select DYNAMIC_MEMORY_LAYOUT 2231 default RANDOMIZE_BASE 2232 ---help--- 2233 Randomizes the base virtual address of kernel memory sections 2234 (physical memory mapping, vmalloc & vmemmap). This security feature 2235 makes exploits relying on predictable memory locations less reliable. 2236 2237 The order of allocations remains unchanged. Entropy is generated in 2238 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2239 configuration have in average 30,000 different possible virtual 2240 addresses for each memory section. 2241 2242 If unsure, say Y. 2243 2244config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2245 hex "Physical memory mapping padding" if EXPERT 2246 depends on RANDOMIZE_MEMORY 2247 default "0xa" if MEMORY_HOTPLUG 2248 default "0x0" 2249 range 0x1 0x40 if MEMORY_HOTPLUG 2250 range 0x0 0x40 2251 ---help--- 2252 Define the padding in terabytes added to the existing physical 2253 memory size during kernel memory randomization. It is useful 2254 for memory hotplug support but reduces the entropy available for 2255 address randomization. 2256 2257 If unsure, leave at the default value. 2258 2259config HOTPLUG_CPU 2260 def_bool y 2261 depends on SMP 2262 2263config BOOTPARAM_HOTPLUG_CPU0 2264 bool "Set default setting of cpu0_hotpluggable" 2265 depends on HOTPLUG_CPU 2266 ---help--- 2267 Set whether default state of cpu0_hotpluggable is on or off. 2268 2269 Say Y here to enable CPU0 hotplug by default. If this switch 2270 is turned on, there is no need to give cpu0_hotplug kernel 2271 parameter and the CPU0 hotplug feature is enabled by default. 2272 2273 Please note: there are two known CPU0 dependencies if you want 2274 to enable the CPU0 hotplug feature either by this switch or by 2275 cpu0_hotplug kernel parameter. 2276 2277 First, resume from hibernate or suspend always starts from CPU0. 2278 So hibernate and suspend are prevented if CPU0 is offline. 2279 2280 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2281 offline if any interrupt can not migrate out of CPU0. There may 2282 be other CPU0 dependencies. 2283 2284 Please make sure the dependencies are under your control before 2285 you enable this feature. 2286 2287 Say N if you don't want to enable CPU0 hotplug feature by default. 2288 You still can enable the CPU0 hotplug feature at boot by kernel 2289 parameter cpu0_hotplug. 2290 2291config DEBUG_HOTPLUG_CPU0 2292 def_bool n 2293 prompt "Debug CPU0 hotplug" 2294 depends on HOTPLUG_CPU 2295 ---help--- 2296 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2297 soon as possible and boots up userspace with CPU0 offlined. User 2298 can online CPU0 back after boot time. 2299 2300 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2301 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2302 compilation or giving cpu0_hotplug kernel parameter at boot. 2303 2304 If unsure, say N. 2305 2306config COMPAT_VDSO 2307 def_bool n 2308 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2309 depends on COMPAT_32 2310 ---help--- 2311 Certain buggy versions of glibc will crash if they are 2312 presented with a 32-bit vDSO that is not mapped at the address 2313 indicated in its segment table. 2314 2315 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2316 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2317 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2318 the only released version with the bug, but OpenSUSE 9 2319 contains a buggy "glibc 2.3.2". 2320 2321 The symptom of the bug is that everything crashes on startup, saying: 2322 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2323 2324 Saying Y here changes the default value of the vdso32 boot 2325 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2326 This works around the glibc bug but hurts performance. 2327 2328 If unsure, say N: if you are compiling your own kernel, you 2329 are unlikely to be using a buggy version of glibc. 2330 2331choice 2332 prompt "vsyscall table for legacy applications" 2333 depends on X86_64 2334 default LEGACY_VSYSCALL_XONLY 2335 help 2336 Legacy user code that does not know how to find the vDSO expects 2337 to be able to issue three syscalls by calling fixed addresses in 2338 kernel space. Since this location is not randomized with ASLR, 2339 it can be used to assist security vulnerability exploitation. 2340 2341 This setting can be changed at boot time via the kernel command 2342 line parameter vsyscall=[emulate|xonly|none]. 2343 2344 On a system with recent enough glibc (2.14 or newer) and no 2345 static binaries, you can say None without a performance penalty 2346 to improve security. 2347 2348 If unsure, select "Emulate execution only". 2349 2350 config LEGACY_VSYSCALL_EMULATE 2351 bool "Full emulation" 2352 help 2353 The kernel traps and emulates calls into the fixed vsyscall 2354 address mapping. This makes the mapping non-executable, but 2355 it still contains readable known contents, which could be 2356 used in certain rare security vulnerability exploits. This 2357 configuration is recommended when using legacy userspace 2358 that still uses vsyscalls along with legacy binary 2359 instrumentation tools that require code to be readable. 2360 2361 An example of this type of legacy userspace is running 2362 Pin on an old binary that still uses vsyscalls. 2363 2364 config LEGACY_VSYSCALL_XONLY 2365 bool "Emulate execution only" 2366 help 2367 The kernel traps and emulates calls into the fixed vsyscall 2368 address mapping and does not allow reads. This 2369 configuration is recommended when userspace might use the 2370 legacy vsyscall area but support for legacy binary 2371 instrumentation of legacy code is not needed. It mitigates 2372 certain uses of the vsyscall area as an ASLR-bypassing 2373 buffer. 2374 2375 config LEGACY_VSYSCALL_NONE 2376 bool "None" 2377 help 2378 There will be no vsyscall mapping at all. This will 2379 eliminate any risk of ASLR bypass due to the vsyscall 2380 fixed address mapping. Attempts to use the vsyscalls 2381 will be reported to dmesg, so that either old or 2382 malicious userspace programs can be identified. 2383 2384endchoice 2385 2386config CMDLINE_BOOL 2387 bool "Built-in kernel command line" 2388 ---help--- 2389 Allow for specifying boot arguments to the kernel at 2390 build time. On some systems (e.g. embedded ones), it is 2391 necessary or convenient to provide some or all of the 2392 kernel boot arguments with the kernel itself (that is, 2393 to not rely on the boot loader to provide them.) 2394 2395 To compile command line arguments into the kernel, 2396 set this option to 'Y', then fill in the 2397 boot arguments in CONFIG_CMDLINE. 2398 2399 Systems with fully functional boot loaders (i.e. non-embedded) 2400 should leave this option set to 'N'. 2401 2402config CMDLINE 2403 string "Built-in kernel command string" 2404 depends on CMDLINE_BOOL 2405 default "" 2406 ---help--- 2407 Enter arguments here that should be compiled into the kernel 2408 image and used at boot time. If the boot loader provides a 2409 command line at boot time, it is appended to this string to 2410 form the full kernel command line, when the system boots. 2411 2412 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2413 change this behavior. 2414 2415 In most cases, the command line (whether built-in or provided 2416 by the boot loader) should specify the device for the root 2417 file system. 2418 2419config CMDLINE_OVERRIDE 2420 bool "Built-in command line overrides boot loader arguments" 2421 depends on CMDLINE_BOOL 2422 ---help--- 2423 Set this option to 'Y' to have the kernel ignore the boot loader 2424 command line, and use ONLY the built-in command line. 2425 2426 This is used to work around broken boot loaders. This should 2427 be set to 'N' under normal conditions. 2428 2429config MODIFY_LDT_SYSCALL 2430 bool "Enable the LDT (local descriptor table)" if EXPERT 2431 default y 2432 ---help--- 2433 Linux can allow user programs to install a per-process x86 2434 Local Descriptor Table (LDT) using the modify_ldt(2) system 2435 call. This is required to run 16-bit or segmented code such as 2436 DOSEMU or some Wine programs. It is also used by some very old 2437 threading libraries. 2438 2439 Enabling this feature adds a small amount of overhead to 2440 context switches and increases the low-level kernel attack 2441 surface. Disabling it removes the modify_ldt(2) system call. 2442 2443 Saying 'N' here may make sense for embedded or server kernels. 2444 2445source "kernel/livepatch/Kconfig" 2446 2447endmenu 2448 2449config ARCH_HAS_ADD_PAGES 2450 def_bool y 2451 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2452 2453config ARCH_ENABLE_MEMORY_HOTPLUG 2454 def_bool y 2455 depends on X86_64 || (X86_32 && HIGHMEM) 2456 2457config ARCH_ENABLE_MEMORY_HOTREMOVE 2458 def_bool y 2459 depends on MEMORY_HOTPLUG 2460 2461config USE_PERCPU_NUMA_NODE_ID 2462 def_bool y 2463 depends on NUMA 2464 2465config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2466 def_bool y 2467 depends on X86_64 || X86_PAE 2468 2469config ARCH_ENABLE_HUGEPAGE_MIGRATION 2470 def_bool y 2471 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2472 2473config ARCH_ENABLE_THP_MIGRATION 2474 def_bool y 2475 depends on X86_64 && TRANSPARENT_HUGEPAGE 2476 2477menu "Power management and ACPI options" 2478 2479config ARCH_HIBERNATION_HEADER 2480 def_bool y 2481 depends on HIBERNATION 2482 2483source "kernel/power/Kconfig" 2484 2485source "drivers/acpi/Kconfig" 2486 2487source "drivers/sfi/Kconfig" 2488 2489config X86_APM_BOOT 2490 def_bool y 2491 depends on APM 2492 2493menuconfig APM 2494 tristate "APM (Advanced Power Management) BIOS support" 2495 depends on X86_32 && PM_SLEEP 2496 ---help--- 2497 APM is a BIOS specification for saving power using several different 2498 techniques. This is mostly useful for battery powered laptops with 2499 APM compliant BIOSes. If you say Y here, the system time will be 2500 reset after a RESUME operation, the /proc/apm device will provide 2501 battery status information, and user-space programs will receive 2502 notification of APM "events" (e.g. battery status change). 2503 2504 If you select "Y" here, you can disable actual use of the APM 2505 BIOS by passing the "apm=off" option to the kernel at boot time. 2506 2507 Note that the APM support is almost completely disabled for 2508 machines with more than one CPU. 2509 2510 In order to use APM, you will need supporting software. For location 2511 and more information, read <file:Documentation/power/apm-acpi.rst> 2512 and the Battery Powered Linux mini-HOWTO, available from 2513 <http://www.tldp.org/docs.html#howto>. 2514 2515 This driver does not spin down disk drives (see the hdparm(8) 2516 manpage ("man 8 hdparm") for that), and it doesn't turn off 2517 VESA-compliant "green" monitors. 2518 2519 This driver does not support the TI 4000M TravelMate and the ACER 2520 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2521 desktop machines also don't have compliant BIOSes, and this driver 2522 may cause those machines to panic during the boot phase. 2523 2524 Generally, if you don't have a battery in your machine, there isn't 2525 much point in using this driver and you should say N. If you get 2526 random kernel OOPSes or reboots that don't seem to be related to 2527 anything, try disabling/enabling this option (or disabling/enabling 2528 APM in your BIOS). 2529 2530 Some other things you should try when experiencing seemingly random, 2531 "weird" problems: 2532 2533 1) make sure that you have enough swap space and that it is 2534 enabled. 2535 2) pass the "no-hlt" option to the kernel 2536 3) switch on floating point emulation in the kernel and pass 2537 the "no387" option to the kernel 2538 4) pass the "floppy=nodma" option to the kernel 2539 5) pass the "mem=4M" option to the kernel (thereby disabling 2540 all but the first 4 MB of RAM) 2541 6) make sure that the CPU is not over clocked. 2542 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2543 8) disable the cache from your BIOS settings 2544 9) install a fan for the video card or exchange video RAM 2545 10) install a better fan for the CPU 2546 11) exchange RAM chips 2547 12) exchange the motherboard. 2548 2549 To compile this driver as a module, choose M here: the 2550 module will be called apm. 2551 2552if APM 2553 2554config APM_IGNORE_USER_SUSPEND 2555 bool "Ignore USER SUSPEND" 2556 ---help--- 2557 This option will ignore USER SUSPEND requests. On machines with a 2558 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2559 series notebooks, it is necessary to say Y because of a BIOS bug. 2560 2561config APM_DO_ENABLE 2562 bool "Enable PM at boot time" 2563 ---help--- 2564 Enable APM features at boot time. From page 36 of the APM BIOS 2565 specification: "When disabled, the APM BIOS does not automatically 2566 power manage devices, enter the Standby State, enter the Suspend 2567 State, or take power saving steps in response to CPU Idle calls." 2568 This driver will make CPU Idle calls when Linux is idle (unless this 2569 feature is turned off -- see "Do CPU IDLE calls", below). This 2570 should always save battery power, but more complicated APM features 2571 will be dependent on your BIOS implementation. You may need to turn 2572 this option off if your computer hangs at boot time when using APM 2573 support, or if it beeps continuously instead of suspending. Turn 2574 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2575 T400CDT. This is off by default since most machines do fine without 2576 this feature. 2577 2578config APM_CPU_IDLE 2579 depends on CPU_IDLE 2580 bool "Make CPU Idle calls when idle" 2581 ---help--- 2582 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2583 On some machines, this can activate improved power savings, such as 2584 a slowed CPU clock rate, when the machine is idle. These idle calls 2585 are made after the idle loop has run for some length of time (e.g., 2586 333 mS). On some machines, this will cause a hang at boot time or 2587 whenever the CPU becomes idle. (On machines with more than one CPU, 2588 this option does nothing.) 2589 2590config APM_DISPLAY_BLANK 2591 bool "Enable console blanking using APM" 2592 ---help--- 2593 Enable console blanking using the APM. Some laptops can use this to 2594 turn off the LCD backlight when the screen blanker of the Linux 2595 virtual console blanks the screen. Note that this is only used by 2596 the virtual console screen blanker, and won't turn off the backlight 2597 when using the X Window system. This also doesn't have anything to 2598 do with your VESA-compliant power-saving monitor. Further, this 2599 option doesn't work for all laptops -- it might not turn off your 2600 backlight at all, or it might print a lot of errors to the console, 2601 especially if you are using gpm. 2602 2603config APM_ALLOW_INTS 2604 bool "Allow interrupts during APM BIOS calls" 2605 ---help--- 2606 Normally we disable external interrupts while we are making calls to 2607 the APM BIOS as a measure to lessen the effects of a badly behaving 2608 BIOS implementation. The BIOS should reenable interrupts if it 2609 needs to. Unfortunately, some BIOSes do not -- especially those in 2610 many of the newer IBM Thinkpads. If you experience hangs when you 2611 suspend, try setting this to Y. Otherwise, say N. 2612 2613endif # APM 2614 2615source "drivers/cpufreq/Kconfig" 2616 2617source "drivers/cpuidle/Kconfig" 2618 2619source "drivers/idle/Kconfig" 2620 2621endmenu 2622 2623 2624menu "Bus options (PCI etc.)" 2625 2626choice 2627 prompt "PCI access mode" 2628 depends on X86_32 && PCI 2629 default PCI_GOANY 2630 ---help--- 2631 On PCI systems, the BIOS can be used to detect the PCI devices and 2632 determine their configuration. However, some old PCI motherboards 2633 have BIOS bugs and may crash if this is done. Also, some embedded 2634 PCI-based systems don't have any BIOS at all. Linux can also try to 2635 detect the PCI hardware directly without using the BIOS. 2636 2637 With this option, you can specify how Linux should detect the 2638 PCI devices. If you choose "BIOS", the BIOS will be used, 2639 if you choose "Direct", the BIOS won't be used, and if you 2640 choose "MMConfig", then PCI Express MMCONFIG will be used. 2641 If you choose "Any", the kernel will try MMCONFIG, then the 2642 direct access method and falls back to the BIOS if that doesn't 2643 work. If unsure, go with the default, which is "Any". 2644 2645config PCI_GOBIOS 2646 bool "BIOS" 2647 2648config PCI_GOMMCONFIG 2649 bool "MMConfig" 2650 2651config PCI_GODIRECT 2652 bool "Direct" 2653 2654config PCI_GOOLPC 2655 bool "OLPC XO-1" 2656 depends on OLPC 2657 2658config PCI_GOANY 2659 bool "Any" 2660 2661endchoice 2662 2663config PCI_BIOS 2664 def_bool y 2665 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2666 2667# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2668config PCI_DIRECT 2669 def_bool y 2670 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2671 2672config PCI_MMCONFIG 2673 bool "Support mmconfig PCI config space access" if X86_64 2674 default y 2675 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2676 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2677 2678config PCI_OLPC 2679 def_bool y 2680 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2681 2682config PCI_XEN 2683 def_bool y 2684 depends on PCI && XEN 2685 select SWIOTLB_XEN 2686 2687config MMCONF_FAM10H 2688 def_bool y 2689 depends on X86_64 && PCI_MMCONFIG && ACPI 2690 2691config PCI_CNB20LE_QUIRK 2692 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2693 depends on PCI 2694 help 2695 Read the PCI windows out of the CNB20LE host bridge. This allows 2696 PCI hotplug to work on systems with the CNB20LE chipset which do 2697 not have ACPI. 2698 2699 There's no public spec for this chipset, and this functionality 2700 is known to be incomplete. 2701 2702 You should say N unless you know you need this. 2703 2704config ISA_BUS 2705 bool "ISA bus support on modern systems" if EXPERT 2706 help 2707 Expose ISA bus device drivers and options available for selection and 2708 configuration. Enable this option if your target machine has an ISA 2709 bus. ISA is an older system, displaced by PCI and newer bus 2710 architectures -- if your target machine is modern, it probably does 2711 not have an ISA bus. 2712 2713 If unsure, say N. 2714 2715# x86_64 have no ISA slots, but can have ISA-style DMA. 2716config ISA_DMA_API 2717 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2718 default y 2719 help 2720 Enables ISA-style DMA support for devices requiring such controllers. 2721 If unsure, say Y. 2722 2723if X86_32 2724 2725config ISA 2726 bool "ISA support" 2727 ---help--- 2728 Find out whether you have ISA slots on your motherboard. ISA is the 2729 name of a bus system, i.e. the way the CPU talks to the other stuff 2730 inside your box. Other bus systems are PCI, EISA, MicroChannel 2731 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2732 newer boards don't support it. If you have ISA, say Y, otherwise N. 2733 2734config SCx200 2735 tristate "NatSemi SCx200 support" 2736 ---help--- 2737 This provides basic support for National Semiconductor's 2738 (now AMD's) Geode processors. The driver probes for the 2739 PCI-IDs of several on-chip devices, so its a good dependency 2740 for other scx200_* drivers. 2741 2742 If compiled as a module, the driver is named scx200. 2743 2744config SCx200HR_TIMER 2745 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2746 depends on SCx200 2747 default y 2748 ---help--- 2749 This driver provides a clocksource built upon the on-chip 2750 27MHz high-resolution timer. Its also a workaround for 2751 NSC Geode SC-1100's buggy TSC, which loses time when the 2752 processor goes idle (as is done by the scheduler). The 2753 other workaround is idle=poll boot option. 2754 2755config OLPC 2756 bool "One Laptop Per Child support" 2757 depends on !X86_PAE 2758 select GPIOLIB 2759 select OF 2760 select OF_PROMTREE 2761 select IRQ_DOMAIN 2762 select OLPC_EC 2763 ---help--- 2764 Add support for detecting the unique features of the OLPC 2765 XO hardware. 2766 2767config OLPC_XO1_PM 2768 bool "OLPC XO-1 Power Management" 2769 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2770 ---help--- 2771 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2772 2773config OLPC_XO1_RTC 2774 bool "OLPC XO-1 Real Time Clock" 2775 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2776 ---help--- 2777 Add support for the XO-1 real time clock, which can be used as a 2778 programmable wakeup source. 2779 2780config OLPC_XO1_SCI 2781 bool "OLPC XO-1 SCI extras" 2782 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2783 depends on INPUT=y 2784 select POWER_SUPPLY 2785 ---help--- 2786 Add support for SCI-based features of the OLPC XO-1 laptop: 2787 - EC-driven system wakeups 2788 - Power button 2789 - Ebook switch 2790 - Lid switch 2791 - AC adapter status updates 2792 - Battery status updates 2793 2794config OLPC_XO15_SCI 2795 bool "OLPC XO-1.5 SCI extras" 2796 depends on OLPC && ACPI 2797 select POWER_SUPPLY 2798 ---help--- 2799 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2800 - EC-driven system wakeups 2801 - AC adapter status updates 2802 - Battery status updates 2803 2804config ALIX 2805 bool "PCEngines ALIX System Support (LED setup)" 2806 select GPIOLIB 2807 ---help--- 2808 This option enables system support for the PCEngines ALIX. 2809 At present this just sets up LEDs for GPIO control on 2810 ALIX2/3/6 boards. However, other system specific setup should 2811 get added here. 2812 2813 Note: You must still enable the drivers for GPIO and LED support 2814 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2815 2816 Note: You have to set alix.force=1 for boards with Award BIOS. 2817 2818config NET5501 2819 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2820 select GPIOLIB 2821 ---help--- 2822 This option enables system support for the Soekris Engineering net5501. 2823 2824config GEOS 2825 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2826 select GPIOLIB 2827 depends on DMI 2828 ---help--- 2829 This option enables system support for the Traverse Technologies GEOS. 2830 2831config TS5500 2832 bool "Technologic Systems TS-5500 platform support" 2833 depends on MELAN 2834 select CHECK_SIGNATURE 2835 select NEW_LEDS 2836 select LEDS_CLASS 2837 ---help--- 2838 This option enables system support for the Technologic Systems TS-5500. 2839 2840endif # X86_32 2841 2842config AMD_NB 2843 def_bool y 2844 depends on CPU_SUP_AMD && PCI 2845 2846config X86_SYSFB 2847 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2848 help 2849 Firmwares often provide initial graphics framebuffers so the BIOS, 2850 bootloader or kernel can show basic video-output during boot for 2851 user-guidance and debugging. Historically, x86 used the VESA BIOS 2852 Extensions and EFI-framebuffers for this, which are mostly limited 2853 to x86. 2854 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2855 framebuffers so the new generic system-framebuffer drivers can be 2856 used on x86. If the framebuffer is not compatible with the generic 2857 modes, it is advertised as fallback platform framebuffer so legacy 2858 drivers like efifb, vesafb and uvesafb can pick it up. 2859 If this option is not selected, all system framebuffers are always 2860 marked as fallback platform framebuffers as usual. 2861 2862 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2863 not be able to pick up generic system framebuffers if this option 2864 is selected. You are highly encouraged to enable simplefb as 2865 replacement if you select this option. simplefb can correctly deal 2866 with generic system framebuffers. But you should still keep vesafb 2867 and others enabled as fallback if a system framebuffer is 2868 incompatible with simplefb. 2869 2870 If unsure, say Y. 2871 2872endmenu 2873 2874 2875menu "Binary Emulations" 2876 2877config IA32_EMULATION 2878 bool "IA32 Emulation" 2879 depends on X86_64 2880 select ARCH_WANT_OLD_COMPAT_IPC 2881 select BINFMT_ELF 2882 select COMPAT_BINFMT_ELF 2883 select COMPAT_OLD_SIGACTION 2884 ---help--- 2885 Include code to run legacy 32-bit programs under a 2886 64-bit kernel. You should likely turn this on, unless you're 2887 100% sure that you don't have any 32-bit programs left. 2888 2889config IA32_AOUT 2890 tristate "IA32 a.out support" 2891 depends on IA32_EMULATION 2892 depends on BROKEN 2893 ---help--- 2894 Support old a.out binaries in the 32bit emulation. 2895 2896config X86_X32 2897 bool "x32 ABI for 64-bit mode" 2898 depends on X86_64 2899 ---help--- 2900 Include code to run binaries for the x32 native 32-bit ABI 2901 for 64-bit processors. An x32 process gets access to the 2902 full 64-bit register file and wide data path while leaving 2903 pointers at 32 bits for smaller memory footprint. 2904 2905 You will need a recent binutils (2.22 or later) with 2906 elf32_x86_64 support enabled to compile a kernel with this 2907 option set. 2908 2909config COMPAT_32 2910 def_bool y 2911 depends on IA32_EMULATION || X86_32 2912 select HAVE_UID16 2913 select OLD_SIGSUSPEND3 2914 2915config COMPAT 2916 def_bool y 2917 depends on IA32_EMULATION || X86_X32 2918 2919if COMPAT 2920config COMPAT_FOR_U64_ALIGNMENT 2921 def_bool y 2922 2923config SYSVIPC_COMPAT 2924 def_bool y 2925 depends on SYSVIPC 2926endif 2927 2928endmenu 2929 2930 2931config HAVE_ATOMIC_IOMAP 2932 def_bool y 2933 depends on X86_32 2934 2935source "drivers/firmware/Kconfig" 2936 2937source "arch/x86/kvm/Kconfig" 2938