1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_DEBUG_STACKOVERFLOW 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 select GENERIC_VDSO_32 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select NEED_DMA_MAP_STATE 32 select SWIOTLB 33 select ARCH_HAS_SYSCALL_WRAPPER 34 35config FORCE_DYNAMIC_FTRACE 36 def_bool y 37 depends on X86_32 38 depends on FUNCTION_TRACER 39 select DYNAMIC_FTRACE 40 help 41 We keep the static function tracing (!DYNAMIC_FTRACE) around 42 in order to test the non static function tracing in the 43 generic code, as other architectures still use it. But we 44 only need to keep it around for x86_64. No need to keep it 45 for x86_32. For x86_32, force DYNAMIC_FTRACE. 46# 47# Arch settings 48# 49# ( Note that options that are marked 'if X86_64' could in principle be 50# ported to 32-bit as well. ) 51# 52config X86 53 def_bool y 54 # 55 # Note: keep this list sorted alphabetically 56 # 57 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 59 select ARCH_32BIT_OFF_T if X86_32 60 select ARCH_CLOCKSOURCE_DATA 61 select ARCH_CLOCKSOURCE_INIT 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 63 select ARCH_HAS_DEBUG_VIRTUAL 64 select ARCH_HAS_DEVMEM_IS_ALLOWED 65 select ARCH_HAS_ELF_RANDOMIZE 66 select ARCH_HAS_FAST_MULTIPLIER 67 select ARCH_HAS_FILTER_PGPROT 68 select ARCH_HAS_FORTIFY_SOURCE 69 select ARCH_HAS_GCOV_PROFILE_ALL 70 select ARCH_HAS_KCOV if X86_64 71 select ARCH_HAS_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_REFCOUNT 77 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 78 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 79 select ARCH_HAS_SET_MEMORY 80 select ARCH_HAS_SET_DIRECT_MAP 81 select ARCH_HAS_STRICT_KERNEL_RWX 82 select ARCH_HAS_STRICT_MODULE_RWX 83 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 84 select ARCH_HAS_UBSAN_SANITIZE_ALL 85 select ARCH_HAVE_NMI_SAFE_CMPXCHG 86 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 87 select ARCH_MIGHT_HAVE_PC_PARPORT 88 select ARCH_MIGHT_HAVE_PC_SERIO 89 select ARCH_STACKWALK 90 select ARCH_SUPPORTS_ACPI 91 select ARCH_SUPPORTS_ATOMIC_RMW 92 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 93 select ARCH_USE_BUILTIN_BSWAP 94 select ARCH_USE_QUEUED_RWLOCKS 95 select ARCH_USE_QUEUED_SPINLOCKS 96 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 97 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 98 select ARCH_WANT_HUGE_PMD_SHARE 99 select ARCH_WANTS_THP_SWAP if X86_64 100 select BUILDTIME_EXTABLE_SORT 101 select CLKEVT_I8253 102 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 103 select CLOCKSOURCE_WATCHDOG 104 select DCACHE_WORD_ACCESS 105 select EDAC_ATOMIC_SCRUB 106 select EDAC_SUPPORT 107 select GENERIC_CLOCKEVENTS 108 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 109 select GENERIC_CLOCKEVENTS_MIN_ADJUST 110 select GENERIC_CMOS_UPDATE 111 select GENERIC_CPU_AUTOPROBE 112 select GENERIC_CPU_VULNERABILITIES 113 select GENERIC_EARLY_IOREMAP 114 select GENERIC_FIND_FIRST_BIT 115 select GENERIC_IOMAP 116 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 117 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 118 select GENERIC_IRQ_MIGRATION if SMP 119 select GENERIC_IRQ_PROBE 120 select GENERIC_IRQ_RESERVATION_MODE 121 select GENERIC_IRQ_SHOW 122 select GENERIC_PENDING_IRQ if SMP 123 select GENERIC_SMP_IDLE_THREAD 124 select GENERIC_STRNCPY_FROM_USER 125 select GENERIC_STRNLEN_USER 126 select GENERIC_TIME_VSYSCALL 127 select GENERIC_GETTIMEOFDAY 128 select GUP_GET_PTE_LOW_HIGH if X86_PAE 129 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 130 select HAVE_ACPI_APEI if ACPI 131 select HAVE_ACPI_APEI_NMI if ACPI 132 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 133 select HAVE_ARCH_AUDITSYSCALL 134 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 135 select HAVE_ARCH_JUMP_LABEL 136 select HAVE_ARCH_JUMP_LABEL_RELATIVE 137 select HAVE_ARCH_KASAN if X86_64 138 select HAVE_ARCH_KGDB 139 select HAVE_ARCH_MMAP_RND_BITS if MMU 140 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 141 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 142 select HAVE_ARCH_PREL32_RELOCATIONS 143 select HAVE_ARCH_SECCOMP_FILTER 144 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 145 select HAVE_ARCH_STACKLEAK 146 select HAVE_ARCH_TRACEHOOK 147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 149 select HAVE_ARCH_VMAP_STACK if X86_64 150 select HAVE_ARCH_WITHIN_STACK_FRAMES 151 select HAVE_ASM_MODVERSIONS 152 select HAVE_CMPXCHG_DOUBLE 153 select HAVE_CMPXCHG_LOCAL 154 select HAVE_CONTEXT_TRACKING if X86_64 155 select HAVE_COPY_THREAD_TLS 156 select HAVE_C_RECORDMCOUNT 157 select HAVE_DEBUG_KMEMLEAK 158 select HAVE_DMA_CONTIGUOUS 159 select HAVE_DYNAMIC_FTRACE 160 select HAVE_DYNAMIC_FTRACE_WITH_REGS 161 select HAVE_EBPF_JIT 162 select HAVE_EFFICIENT_UNALIGNED_ACCESS 163 select HAVE_EISA 164 select HAVE_EXIT_THREAD 165 select HAVE_FAST_GUP 166 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 167 select HAVE_FTRACE_MCOUNT_RECORD 168 select HAVE_FUNCTION_GRAPH_TRACER 169 select HAVE_FUNCTION_TRACER 170 select HAVE_GCC_PLUGINS 171 select HAVE_HW_BREAKPOINT 172 select HAVE_IDE 173 select HAVE_IOREMAP_PROT 174 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 175 select HAVE_IRQ_TIME_ACCOUNTING 176 select HAVE_KERNEL_BZIP2 177 select HAVE_KERNEL_GZIP 178 select HAVE_KERNEL_LZ4 179 select HAVE_KERNEL_LZMA 180 select HAVE_KERNEL_LZO 181 select HAVE_KERNEL_XZ 182 select HAVE_KPROBES 183 select HAVE_KPROBES_ON_FTRACE 184 select HAVE_FUNCTION_ERROR_INJECTION 185 select HAVE_KRETPROBES 186 select HAVE_KVM 187 select HAVE_LIVEPATCH if X86_64 188 select HAVE_MEMBLOCK_NODE_MAP 189 select HAVE_MIXED_BREAKPOINTS_REGS 190 select HAVE_MOD_ARCH_SPECIFIC 191 select HAVE_MOVE_PMD 192 select HAVE_NMI 193 select HAVE_OPROFILE 194 select HAVE_OPTPROBES 195 select HAVE_PCSPKR_PLATFORM 196 select HAVE_PERF_EVENTS 197 select HAVE_PERF_EVENTS_NMI 198 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 199 select HAVE_PCI 200 select HAVE_PERF_REGS 201 select HAVE_PERF_USER_STACK_DUMP 202 select HAVE_RCU_TABLE_FREE if PARAVIRT 203 select HAVE_REGS_AND_STACK_ACCESS_API 204 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 205 select HAVE_FUNCTION_ARG_ACCESS_API 206 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 207 select HAVE_STACK_VALIDATION if X86_64 208 select HAVE_RSEQ 209 select HAVE_SYSCALL_TRACEPOINTS 210 select HAVE_UNSTABLE_SCHED_CLOCK 211 select HAVE_USER_RETURN_NOTIFIER 212 select HAVE_GENERIC_VDSO 213 select HOTPLUG_SMT if SMP 214 select IRQ_FORCED_THREADING 215 select NEED_SG_DMA_LENGTH 216 select PCI_DOMAINS if PCI 217 select PCI_LOCKLESS_CONFIG if PCI 218 select PERF_EVENTS 219 select RTC_LIB 220 select RTC_MC146818_LIB 221 select SPARSE_IRQ 222 select SRCU 223 select SYSCTL_EXCEPTION_TRACE 224 select THREAD_INFO_IN_TASK 225 select USER_STACKTRACE_SUPPORT 226 select VIRT_TO_BUS 227 select X86_FEATURE_NAMES if PROC_FS 228 select PROC_PID_ARCH_STATUS if PROC_FS 229 230config INSTRUCTION_DECODER 231 def_bool y 232 depends on KPROBES || PERF_EVENTS || UPROBES 233 234config OUTPUT_FORMAT 235 string 236 default "elf32-i386" if X86_32 237 default "elf64-x86-64" if X86_64 238 239config ARCH_DEFCONFIG 240 string 241 default "arch/x86/configs/i386_defconfig" if X86_32 242 default "arch/x86/configs/x86_64_defconfig" if X86_64 243 244config LOCKDEP_SUPPORT 245 def_bool y 246 247config STACKTRACE_SUPPORT 248 def_bool y 249 250config MMU 251 def_bool y 252 253config ARCH_MMAP_RND_BITS_MIN 254 default 28 if 64BIT 255 default 8 256 257config ARCH_MMAP_RND_BITS_MAX 258 default 32 if 64BIT 259 default 16 260 261config ARCH_MMAP_RND_COMPAT_BITS_MIN 262 default 8 263 264config ARCH_MMAP_RND_COMPAT_BITS_MAX 265 default 16 266 267config SBUS 268 bool 269 270config GENERIC_ISA_DMA 271 def_bool y 272 depends on ISA_DMA_API 273 274config GENERIC_BUG 275 def_bool y 276 depends on BUG 277 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 278 279config GENERIC_BUG_RELATIVE_POINTERS 280 bool 281 282config ARCH_MAY_HAVE_PC_FDC 283 def_bool y 284 depends on ISA_DMA_API 285 286config GENERIC_CALIBRATE_DELAY 287 def_bool y 288 289config ARCH_HAS_CPU_RELAX 290 def_bool y 291 292config ARCH_HAS_CACHE_LINE_SIZE 293 def_bool y 294 295config ARCH_HAS_FILTER_PGPROT 296 def_bool y 297 298config HAVE_SETUP_PER_CPU_AREA 299 def_bool y 300 301config NEED_PER_CPU_EMBED_FIRST_CHUNK 302 def_bool y 303 304config NEED_PER_CPU_PAGE_FIRST_CHUNK 305 def_bool y 306 307config ARCH_HIBERNATION_POSSIBLE 308 def_bool y 309 310config ARCH_SUSPEND_POSSIBLE 311 def_bool y 312 313config ARCH_WANT_GENERAL_HUGETLB 314 def_bool y 315 316config ZONE_DMA32 317 def_bool y if X86_64 318 319config AUDIT_ARCH 320 def_bool y if X86_64 321 322config ARCH_SUPPORTS_DEBUG_PAGEALLOC 323 def_bool y 324 325config KASAN_SHADOW_OFFSET 326 hex 327 depends on KASAN 328 default 0xdffffc0000000000 329 330config HAVE_INTEL_TXT 331 def_bool y 332 depends on INTEL_IOMMU && ACPI 333 334config X86_32_SMP 335 def_bool y 336 depends on X86_32 && SMP 337 338config X86_64_SMP 339 def_bool y 340 depends on X86_64 && SMP 341 342config X86_32_LAZY_GS 343 def_bool y 344 depends on X86_32 && !STACKPROTECTOR 345 346config ARCH_SUPPORTS_UPROBES 347 def_bool y 348 349config FIX_EARLYCON_MEM 350 def_bool y 351 352config DYNAMIC_PHYSICAL_MASK 353 bool 354 355config PGTABLE_LEVELS 356 int 357 default 5 if X86_5LEVEL 358 default 4 if X86_64 359 default 3 if X86_PAE 360 default 2 361 362config CC_HAS_SANE_STACKPROTECTOR 363 bool 364 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 365 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 366 help 367 We have to make sure stack protector is unconditionally disabled if 368 the compiler produces broken code. 369 370menu "Processor type and features" 371 372config ZONE_DMA 373 bool "DMA memory allocation support" if EXPERT 374 default y 375 help 376 DMA memory allocation support allows devices with less than 32-bit 377 addressing to allocate within the first 16MB of address space. 378 Disable if no such devices will be used. 379 380 If unsure, say Y. 381 382config SMP 383 bool "Symmetric multi-processing support" 384 ---help--- 385 This enables support for systems with more than one CPU. If you have 386 a system with only one CPU, say N. If you have a system with more 387 than one CPU, say Y. 388 389 If you say N here, the kernel will run on uni- and multiprocessor 390 machines, but will use only one CPU of a multiprocessor machine. If 391 you say Y here, the kernel will run on many, but not all, 392 uniprocessor machines. On a uniprocessor machine, the kernel 393 will run faster if you say N here. 394 395 Note that if you say Y here and choose architecture "586" or 396 "Pentium" under "Processor family", the kernel will not work on 486 397 architectures. Similarly, multiprocessor kernels for the "PPro" 398 architecture may not work on all Pentium based boards. 399 400 People using multiprocessor machines who say Y here should also say 401 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 402 Management" code will be disabled if you say Y here. 403 404 See also <file:Documentation/x86/i386/IO-APIC.rst>, 405 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 406 <http://www.tldp.org/docs.html#howto>. 407 408 If you don't know what to do here, say N. 409 410config X86_FEATURE_NAMES 411 bool "Processor feature human-readable names" if EMBEDDED 412 default y 413 ---help--- 414 This option compiles in a table of x86 feature bits and corresponding 415 names. This is required to support /proc/cpuinfo and a few kernel 416 messages. You can disable this to save space, at the expense of 417 making those few kernel messages show numeric feature bits instead. 418 419 If in doubt, say Y. 420 421config X86_X2APIC 422 bool "Support x2apic" 423 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 424 ---help--- 425 This enables x2apic support on CPUs that have this feature. 426 427 This allows 32-bit apic IDs (so it can support very large systems), 428 and accesses the local apic via MSRs not via mmio. 429 430 If you don't know what to do here, say N. 431 432config X86_MPPARSE 433 bool "Enable MPS table" if ACPI || SFI 434 default y 435 depends on X86_LOCAL_APIC 436 ---help--- 437 For old smp systems that do not have proper acpi support. Newer systems 438 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 439 440config GOLDFISH 441 def_bool y 442 depends on X86_GOLDFISH 443 444config RETPOLINE 445 bool "Avoid speculative indirect branches in kernel" 446 default y 447 select STACK_VALIDATION if HAVE_STACK_VALIDATION 448 help 449 Compile kernel with the retpoline compiler options to guard against 450 kernel-to-user data leaks by avoiding speculative indirect 451 branches. Requires a compiler with -mindirect-branch=thunk-extern 452 support for full protection. The kernel may run slower. 453 454config X86_CPU_RESCTRL 455 bool "x86 CPU resource control support" 456 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 457 select KERNFS 458 help 459 Enable x86 CPU resource control support. 460 461 Provide support for the allocation and monitoring of system resources 462 usage by the CPU. 463 464 Intel calls this Intel Resource Director Technology 465 (Intel(R) RDT). More information about RDT can be found in the 466 Intel x86 Architecture Software Developer Manual. 467 468 AMD calls this AMD Platform Quality of Service (AMD QoS). 469 More information about AMD QoS can be found in the AMD64 Technology 470 Platform Quality of Service Extensions manual. 471 472 Say N if unsure. 473 474if X86_32 475config X86_BIGSMP 476 bool "Support for big SMP systems with more than 8 CPUs" 477 depends on SMP 478 ---help--- 479 This option is needed for the systems that have more than 8 CPUs 480 481config X86_EXTENDED_PLATFORM 482 bool "Support for extended (non-PC) x86 platforms" 483 default y 484 ---help--- 485 If you disable this option then the kernel will only support 486 standard PC platforms. (which covers the vast majority of 487 systems out there.) 488 489 If you enable this option then you'll be able to select support 490 for the following (non-PC) 32 bit x86 platforms: 491 Goldfish (Android emulator) 492 AMD Elan 493 RDC R-321x SoC 494 SGI 320/540 (Visual Workstation) 495 STA2X11-based (e.g. Northville) 496 Moorestown MID devices 497 498 If you have one of these systems, or if you want to build a 499 generic distribution kernel, say Y here - otherwise say N. 500endif 501 502if X86_64 503config X86_EXTENDED_PLATFORM 504 bool "Support for extended (non-PC) x86 platforms" 505 default y 506 ---help--- 507 If you disable this option then the kernel will only support 508 standard PC platforms. (which covers the vast majority of 509 systems out there.) 510 511 If you enable this option then you'll be able to select support 512 for the following (non-PC) 64 bit x86 platforms: 513 Numascale NumaChip 514 ScaleMP vSMP 515 SGI Ultraviolet 516 517 If you have one of these systems, or if you want to build a 518 generic distribution kernel, say Y here - otherwise say N. 519endif 520# This is an alphabetically sorted list of 64 bit extended platforms 521# Please maintain the alphabetic order if and when there are additions 522config X86_NUMACHIP 523 bool "Numascale NumaChip" 524 depends on X86_64 525 depends on X86_EXTENDED_PLATFORM 526 depends on NUMA 527 depends on SMP 528 depends on X86_X2APIC 529 depends on PCI_MMCONFIG 530 ---help--- 531 Adds support for Numascale NumaChip large-SMP systems. Needed to 532 enable more than ~168 cores. 533 If you don't have one of these, you should say N here. 534 535config X86_VSMP 536 bool "ScaleMP vSMP" 537 select HYPERVISOR_GUEST 538 select PARAVIRT 539 depends on X86_64 && PCI 540 depends on X86_EXTENDED_PLATFORM 541 depends on SMP 542 ---help--- 543 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 544 supposed to run on these EM64T-based machines. Only choose this option 545 if you have one of these machines. 546 547config X86_UV 548 bool "SGI Ultraviolet" 549 depends on X86_64 550 depends on X86_EXTENDED_PLATFORM 551 depends on NUMA 552 depends on EFI 553 depends on X86_X2APIC 554 depends on PCI 555 ---help--- 556 This option is needed in order to support SGI Ultraviolet systems. 557 If you don't have one of these, you should say N here. 558 559# Following is an alphabetically sorted list of 32 bit extended platforms 560# Please maintain the alphabetic order if and when there are additions 561 562config X86_GOLDFISH 563 bool "Goldfish (Virtual Platform)" 564 depends on X86_EXTENDED_PLATFORM 565 ---help--- 566 Enable support for the Goldfish virtual platform used primarily 567 for Android development. Unless you are building for the Android 568 Goldfish emulator say N here. 569 570config X86_INTEL_CE 571 bool "CE4100 TV platform" 572 depends on PCI 573 depends on PCI_GODIRECT 574 depends on X86_IO_APIC 575 depends on X86_32 576 depends on X86_EXTENDED_PLATFORM 577 select X86_REBOOTFIXUPS 578 select OF 579 select OF_EARLY_FLATTREE 580 ---help--- 581 Select for the Intel CE media processor (CE4100) SOC. 582 This option compiles in support for the CE4100 SOC for settop 583 boxes and media devices. 584 585config X86_INTEL_MID 586 bool "Intel MID platform support" 587 depends on X86_EXTENDED_PLATFORM 588 depends on X86_PLATFORM_DEVICES 589 depends on PCI 590 depends on X86_64 || (PCI_GOANY && X86_32) 591 depends on X86_IO_APIC 592 select SFI 593 select I2C 594 select DW_APB_TIMER 595 select APB_TIMER 596 select INTEL_SCU_IPC 597 select MFD_INTEL_MSIC 598 ---help--- 599 Select to build a kernel capable of supporting Intel MID (Mobile 600 Internet Device) platform systems which do not have the PCI legacy 601 interfaces. If you are building for a PC class system say N here. 602 603 Intel MID platforms are based on an Intel processor and chipset which 604 consume less power than most of the x86 derivatives. 605 606config X86_INTEL_QUARK 607 bool "Intel Quark platform support" 608 depends on X86_32 609 depends on X86_EXTENDED_PLATFORM 610 depends on X86_PLATFORM_DEVICES 611 depends on X86_TSC 612 depends on PCI 613 depends on PCI_GOANY 614 depends on X86_IO_APIC 615 select IOSF_MBI 616 select INTEL_IMR 617 select COMMON_CLK 618 ---help--- 619 Select to include support for Quark X1000 SoC. 620 Say Y here if you have a Quark based system such as the Arduino 621 compatible Intel Galileo. 622 623config X86_INTEL_LPSS 624 bool "Intel Low Power Subsystem Support" 625 depends on X86 && ACPI && PCI 626 select COMMON_CLK 627 select PINCTRL 628 select IOSF_MBI 629 ---help--- 630 Select to build support for Intel Low Power Subsystem such as 631 found on Intel Lynxpoint PCH. Selecting this option enables 632 things like clock tree (common clock framework) and pincontrol 633 which are needed by the LPSS peripheral drivers. 634 635config X86_AMD_PLATFORM_DEVICE 636 bool "AMD ACPI2Platform devices support" 637 depends on ACPI 638 select COMMON_CLK 639 select PINCTRL 640 ---help--- 641 Select to interpret AMD specific ACPI device to platform device 642 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 643 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 644 implemented under PINCTRL subsystem. 645 646config IOSF_MBI 647 tristate "Intel SoC IOSF Sideband support for SoC platforms" 648 depends on PCI 649 ---help--- 650 This option enables sideband register access support for Intel SoC 651 platforms. On these platforms the IOSF sideband is used in lieu of 652 MSR's for some register accesses, mostly but not limited to thermal 653 and power. Drivers may query the availability of this device to 654 determine if they need the sideband in order to work on these 655 platforms. The sideband is available on the following SoC products. 656 This list is not meant to be exclusive. 657 - BayTrail 658 - Braswell 659 - Quark 660 661 You should say Y if you are running a kernel on one of these SoC's. 662 663config IOSF_MBI_DEBUG 664 bool "Enable IOSF sideband access through debugfs" 665 depends on IOSF_MBI && DEBUG_FS 666 ---help--- 667 Select this option to expose the IOSF sideband access registers (MCR, 668 MDR, MCRX) through debugfs to write and read register information from 669 different units on the SoC. This is most useful for obtaining device 670 state information for debug and analysis. As this is a general access 671 mechanism, users of this option would have specific knowledge of the 672 device they want to access. 673 674 If you don't require the option or are in doubt, say N. 675 676config X86_RDC321X 677 bool "RDC R-321x SoC" 678 depends on X86_32 679 depends on X86_EXTENDED_PLATFORM 680 select M486 681 select X86_REBOOTFIXUPS 682 ---help--- 683 This option is needed for RDC R-321x system-on-chip, also known 684 as R-8610-(G). 685 If you don't have one of these chips, you should say N here. 686 687config X86_32_NON_STANDARD 688 bool "Support non-standard 32-bit SMP architectures" 689 depends on X86_32 && SMP 690 depends on X86_EXTENDED_PLATFORM 691 ---help--- 692 This option compiles in the bigsmp and STA2X11 default 693 subarchitectures. It is intended for a generic binary 694 kernel. If you select them all, kernel will probe it one by 695 one and will fallback to default. 696 697# Alphabetically sorted list of Non standard 32 bit platforms 698 699config X86_SUPPORTS_MEMORY_FAILURE 700 def_bool y 701 # MCE code calls memory_failure(): 702 depends on X86_MCE 703 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 704 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 705 depends on X86_64 || !SPARSEMEM 706 select ARCH_SUPPORTS_MEMORY_FAILURE 707 708config STA2X11 709 bool "STA2X11 Companion Chip Support" 710 depends on X86_32_NON_STANDARD && PCI 711 select ARCH_HAS_PHYS_TO_DMA 712 select SWIOTLB 713 select MFD_STA2X11 714 select GPIOLIB 715 ---help--- 716 This adds support for boards based on the STA2X11 IO-Hub, 717 a.k.a. "ConneXt". The chip is used in place of the standard 718 PC chipset, so all "standard" peripherals are missing. If this 719 option is selected the kernel will still be able to boot on 720 standard PC machines. 721 722config X86_32_IRIS 723 tristate "Eurobraille/Iris poweroff module" 724 depends on X86_32 725 ---help--- 726 The Iris machines from EuroBraille do not have APM or ACPI support 727 to shut themselves down properly. A special I/O sequence is 728 needed to do so, which is what this module does at 729 kernel shutdown. 730 731 This is only for Iris machines from EuroBraille. 732 733 If unused, say N. 734 735config SCHED_OMIT_FRAME_POINTER 736 def_bool y 737 prompt "Single-depth WCHAN output" 738 depends on X86 739 ---help--- 740 Calculate simpler /proc/<PID>/wchan values. If this option 741 is disabled then wchan values will recurse back to the 742 caller function. This provides more accurate wchan values, 743 at the expense of slightly more scheduling overhead. 744 745 If in doubt, say "Y". 746 747menuconfig HYPERVISOR_GUEST 748 bool "Linux guest support" 749 ---help--- 750 Say Y here to enable options for running Linux under various hyper- 751 visors. This option enables basic hypervisor detection and platform 752 setup. 753 754 If you say N, all options in this submenu will be skipped and 755 disabled, and Linux guest support won't be built in. 756 757if HYPERVISOR_GUEST 758 759config PARAVIRT 760 bool "Enable paravirtualization code" 761 ---help--- 762 This changes the kernel so it can modify itself when it is run 763 under a hypervisor, potentially improving performance significantly 764 over full virtualization. However, when run without a hypervisor 765 the kernel is theoretically slower and slightly larger. 766 767config PARAVIRT_XXL 768 bool 769 770config PARAVIRT_DEBUG 771 bool "paravirt-ops debugging" 772 depends on PARAVIRT && DEBUG_KERNEL 773 ---help--- 774 Enable to debug paravirt_ops internals. Specifically, BUG if 775 a paravirt_op is missing when it is called. 776 777config PARAVIRT_SPINLOCKS 778 bool "Paravirtualization layer for spinlocks" 779 depends on PARAVIRT && SMP 780 ---help--- 781 Paravirtualized spinlocks allow a pvops backend to replace the 782 spinlock implementation with something virtualization-friendly 783 (for example, block the virtual CPU rather than spinning). 784 785 It has a minimal impact on native kernels and gives a nice performance 786 benefit on paravirtualized KVM / Xen kernels. 787 788 If you are unsure how to answer this question, answer Y. 789 790config X86_HV_CALLBACK_VECTOR 791 def_bool n 792 793source "arch/x86/xen/Kconfig" 794 795config KVM_GUEST 796 bool "KVM Guest support (including kvmclock)" 797 depends on PARAVIRT 798 select PARAVIRT_CLOCK 799 select ARCH_CPUIDLE_HALTPOLL 800 default y 801 ---help--- 802 This option enables various optimizations for running under the KVM 803 hypervisor. It includes a paravirtualized clock, so that instead 804 of relying on a PIT (or probably other) emulation by the 805 underlying device model, the host provides the guest with 806 timing infrastructure such as time of day, and system time 807 808config ARCH_CPUIDLE_HALTPOLL 809 def_bool n 810 prompt "Disable host haltpoll when loading haltpoll driver" 811 help 812 If virtualized under KVM, disable host haltpoll. 813 814config PVH 815 bool "Support for running PVH guests" 816 ---help--- 817 This option enables the PVH entry point for guest virtual machines 818 as specified in the x86/HVM direct boot ABI. 819 820config KVM_DEBUG_FS 821 bool "Enable debug information for KVM Guests in debugfs" 822 depends on KVM_GUEST && DEBUG_FS 823 ---help--- 824 This option enables collection of various statistics for KVM guest. 825 Statistics are displayed in debugfs filesystem. Enabling this option 826 may incur significant overhead. 827 828config PARAVIRT_TIME_ACCOUNTING 829 bool "Paravirtual steal time accounting" 830 depends on PARAVIRT 831 ---help--- 832 Select this option to enable fine granularity task steal time 833 accounting. Time spent executing other tasks in parallel with 834 the current vCPU is discounted from the vCPU power. To account for 835 that, there can be a small performance impact. 836 837 If in doubt, say N here. 838 839config PARAVIRT_CLOCK 840 bool 841 842config JAILHOUSE_GUEST 843 bool "Jailhouse non-root cell support" 844 depends on X86_64 && PCI 845 select X86_PM_TIMER 846 ---help--- 847 This option allows to run Linux as guest in a Jailhouse non-root 848 cell. You can leave this option disabled if you only want to start 849 Jailhouse and run Linux afterwards in the root cell. 850 851config ACRN_GUEST 852 bool "ACRN Guest support" 853 depends on X86_64 854 select X86_HV_CALLBACK_VECTOR 855 help 856 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 857 a flexible, lightweight reference open-source hypervisor, built with 858 real-time and safety-criticality in mind. It is built for embedded 859 IOT with small footprint and real-time features. More details can be 860 found in https://projectacrn.org/. 861 862endif #HYPERVISOR_GUEST 863 864source "arch/x86/Kconfig.cpu" 865 866config HPET_TIMER 867 def_bool X86_64 868 prompt "HPET Timer Support" if X86_32 869 ---help--- 870 Use the IA-PC HPET (High Precision Event Timer) to manage 871 time in preference to the PIT and RTC, if a HPET is 872 present. 873 HPET is the next generation timer replacing legacy 8254s. 874 The HPET provides a stable time base on SMP 875 systems, unlike the TSC, but it is more expensive to access, 876 as it is off-chip. The interface used is documented 877 in the HPET spec, revision 1. 878 879 You can safely choose Y here. However, HPET will only be 880 activated if the platform and the BIOS support this feature. 881 Otherwise the 8254 will be used for timing services. 882 883 Choose N to continue using the legacy 8254 timer. 884 885config HPET_EMULATE_RTC 886 def_bool y 887 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 888 889config APB_TIMER 890 def_bool y if X86_INTEL_MID 891 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 892 select DW_APB_TIMER 893 depends on X86_INTEL_MID && SFI 894 help 895 APB timer is the replacement for 8254, HPET on X86 MID platforms. 896 The APBT provides a stable time base on SMP 897 systems, unlike the TSC, but it is more expensive to access, 898 as it is off-chip. APB timers are always running regardless of CPU 899 C states, they are used as per CPU clockevent device when possible. 900 901# Mark as expert because too many people got it wrong. 902# The code disables itself when not needed. 903config DMI 904 default y 905 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 906 bool "Enable DMI scanning" if EXPERT 907 ---help--- 908 Enabled scanning of DMI to identify machine quirks. Say Y 909 here unless you have verified that your setup is not 910 affected by entries in the DMI blacklist. Required by PNP 911 BIOS code. 912 913config GART_IOMMU 914 bool "Old AMD GART IOMMU support" 915 select IOMMU_HELPER 916 select SWIOTLB 917 depends on X86_64 && PCI && AMD_NB 918 ---help--- 919 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 920 GART based hardware IOMMUs. 921 922 The GART supports full DMA access for devices with 32-bit access 923 limitations, on systems with more than 3 GB. This is usually needed 924 for USB, sound, many IDE/SATA chipsets and some other devices. 925 926 Newer systems typically have a modern AMD IOMMU, supported via 927 the CONFIG_AMD_IOMMU=y config option. 928 929 In normal configurations this driver is only active when needed: 930 there's more than 3 GB of memory and the system contains a 931 32-bit limited device. 932 933 If unsure, say Y. 934 935config CALGARY_IOMMU 936 bool "IBM Calgary IOMMU support" 937 select IOMMU_HELPER 938 select SWIOTLB 939 depends on X86_64 && PCI 940 ---help--- 941 Support for hardware IOMMUs in IBM's xSeries x366 and x460 942 systems. Needed to run systems with more than 3GB of memory 943 properly with 32-bit PCI devices that do not support DAC 944 (Double Address Cycle). Calgary also supports bus level 945 isolation, where all DMAs pass through the IOMMU. This 946 prevents them from going anywhere except their intended 947 destination. This catches hard-to-find kernel bugs and 948 mis-behaving drivers and devices that do not use the DMA-API 949 properly to set up their DMA buffers. The IOMMU can be 950 turned off at boot time with the iommu=off parameter. 951 Normally the kernel will make the right choice by itself. 952 If unsure, say Y. 953 954config CALGARY_IOMMU_ENABLED_BY_DEFAULT 955 def_bool y 956 prompt "Should Calgary be enabled by default?" 957 depends on CALGARY_IOMMU 958 ---help--- 959 Should Calgary be enabled by default? if you choose 'y', Calgary 960 will be used (if it exists). If you choose 'n', Calgary will not be 961 used even if it exists. If you choose 'n' and would like to use 962 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 963 If unsure, say Y. 964 965config MAXSMP 966 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 967 depends on X86_64 && SMP && DEBUG_KERNEL 968 select CPUMASK_OFFSTACK 969 ---help--- 970 Enable maximum number of CPUS and NUMA Nodes for this architecture. 971 If unsure, say N. 972 973# 974# The maximum number of CPUs supported: 975# 976# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 977# and which can be configured interactively in the 978# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 979# 980# The ranges are different on 32-bit and 64-bit kernels, depending on 981# hardware capabilities and scalability features of the kernel. 982# 983# ( If MAXSMP is enabled we just use the highest possible value and disable 984# interactive configuration. ) 985# 986 987config NR_CPUS_RANGE_BEGIN 988 int 989 default NR_CPUS_RANGE_END if MAXSMP 990 default 1 if !SMP 991 default 2 992 993config NR_CPUS_RANGE_END 994 int 995 depends on X86_32 996 default 64 if SMP && X86_BIGSMP 997 default 8 if SMP && !X86_BIGSMP 998 default 1 if !SMP 999 1000config NR_CPUS_RANGE_END 1001 int 1002 depends on X86_64 1003 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 1004 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 1005 default 1 if !SMP 1006 1007config NR_CPUS_DEFAULT 1008 int 1009 depends on X86_32 1010 default 32 if X86_BIGSMP 1011 default 8 if SMP 1012 default 1 if !SMP 1013 1014config NR_CPUS_DEFAULT 1015 int 1016 depends on X86_64 1017 default 8192 if MAXSMP 1018 default 64 if SMP 1019 default 1 if !SMP 1020 1021config NR_CPUS 1022 int "Maximum number of CPUs" if SMP && !MAXSMP 1023 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1024 default NR_CPUS_DEFAULT 1025 ---help--- 1026 This allows you to specify the maximum number of CPUs which this 1027 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1028 supported value is 8192, otherwise the maximum value is 512. The 1029 minimum value which makes sense is 2. 1030 1031 This is purely to save memory: each supported CPU adds about 8KB 1032 to the kernel image. 1033 1034config SCHED_SMT 1035 def_bool y if SMP 1036 1037config SCHED_MC 1038 def_bool y 1039 prompt "Multi-core scheduler support" 1040 depends on SMP 1041 ---help--- 1042 Multi-core scheduler support improves the CPU scheduler's decision 1043 making when dealing with multi-core CPU chips at a cost of slightly 1044 increased overhead in some places. If unsure say N here. 1045 1046config SCHED_MC_PRIO 1047 bool "CPU core priorities scheduler support" 1048 depends on SCHED_MC && CPU_SUP_INTEL 1049 select X86_INTEL_PSTATE 1050 select CPU_FREQ 1051 default y 1052 ---help--- 1053 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1054 core ordering determined at manufacturing time, which allows 1055 certain cores to reach higher turbo frequencies (when running 1056 single threaded workloads) than others. 1057 1058 Enabling this kernel feature teaches the scheduler about 1059 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1060 scheduler's CPU selection logic accordingly, so that higher 1061 overall system performance can be achieved. 1062 1063 This feature will have no effect on CPUs without this feature. 1064 1065 If unsure say Y here. 1066 1067config UP_LATE_INIT 1068 def_bool y 1069 depends on !SMP && X86_LOCAL_APIC 1070 1071config X86_UP_APIC 1072 bool "Local APIC support on uniprocessors" if !PCI_MSI 1073 default PCI_MSI 1074 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1075 ---help--- 1076 A local APIC (Advanced Programmable Interrupt Controller) is an 1077 integrated interrupt controller in the CPU. If you have a single-CPU 1078 system which has a processor with a local APIC, you can say Y here to 1079 enable and use it. If you say Y here even though your machine doesn't 1080 have a local APIC, then the kernel will still run with no slowdown at 1081 all. The local APIC supports CPU-generated self-interrupts (timer, 1082 performance counters), and the NMI watchdog which detects hard 1083 lockups. 1084 1085config X86_UP_IOAPIC 1086 bool "IO-APIC support on uniprocessors" 1087 depends on X86_UP_APIC 1088 ---help--- 1089 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1090 SMP-capable replacement for PC-style interrupt controllers. Most 1091 SMP systems and many recent uniprocessor systems have one. 1092 1093 If you have a single-CPU system with an IO-APIC, you can say Y here 1094 to use it. If you say Y here even though your machine doesn't have 1095 an IO-APIC, then the kernel will still run with no slowdown at all. 1096 1097config X86_LOCAL_APIC 1098 def_bool y 1099 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1100 select IRQ_DOMAIN_HIERARCHY 1101 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1102 1103config X86_IO_APIC 1104 def_bool y 1105 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1106 1107config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1108 bool "Reroute for broken boot IRQs" 1109 depends on X86_IO_APIC 1110 ---help--- 1111 This option enables a workaround that fixes a source of 1112 spurious interrupts. This is recommended when threaded 1113 interrupt handling is used on systems where the generation of 1114 superfluous "boot interrupts" cannot be disabled. 1115 1116 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1117 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1118 kernel does during interrupt handling). On chipsets where this 1119 boot IRQ generation cannot be disabled, this workaround keeps 1120 the original IRQ line masked so that only the equivalent "boot 1121 IRQ" is delivered to the CPUs. The workaround also tells the 1122 kernel to set up the IRQ handler on the boot IRQ line. In this 1123 way only one interrupt is delivered to the kernel. Otherwise 1124 the spurious second interrupt may cause the kernel to bring 1125 down (vital) interrupt lines. 1126 1127 Only affects "broken" chipsets. Interrupt sharing may be 1128 increased on these systems. 1129 1130config X86_MCE 1131 bool "Machine Check / overheating reporting" 1132 select GENERIC_ALLOCATOR 1133 default y 1134 ---help--- 1135 Machine Check support allows the processor to notify the 1136 kernel if it detects a problem (e.g. overheating, data corruption). 1137 The action the kernel takes depends on the severity of the problem, 1138 ranging from warning messages to halting the machine. 1139 1140config X86_MCELOG_LEGACY 1141 bool "Support for deprecated /dev/mcelog character device" 1142 depends on X86_MCE 1143 ---help--- 1144 Enable support for /dev/mcelog which is needed by the old mcelog 1145 userspace logging daemon. Consider switching to the new generation 1146 rasdaemon solution. 1147 1148config X86_MCE_INTEL 1149 def_bool y 1150 prompt "Intel MCE features" 1151 depends on X86_MCE && X86_LOCAL_APIC 1152 ---help--- 1153 Additional support for intel specific MCE features such as 1154 the thermal monitor. 1155 1156config X86_MCE_AMD 1157 def_bool y 1158 prompt "AMD MCE features" 1159 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1160 ---help--- 1161 Additional support for AMD specific MCE features such as 1162 the DRAM Error Threshold. 1163 1164config X86_ANCIENT_MCE 1165 bool "Support for old Pentium 5 / WinChip machine checks" 1166 depends on X86_32 && X86_MCE 1167 ---help--- 1168 Include support for machine check handling on old Pentium 5 or WinChip 1169 systems. These typically need to be enabled explicitly on the command 1170 line. 1171 1172config X86_MCE_THRESHOLD 1173 depends on X86_MCE_AMD || X86_MCE_INTEL 1174 def_bool y 1175 1176config X86_MCE_INJECT 1177 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1178 tristate "Machine check injector support" 1179 ---help--- 1180 Provide support for injecting machine checks for testing purposes. 1181 If you don't know what a machine check is and you don't do kernel 1182 QA it is safe to say n. 1183 1184config X86_THERMAL_VECTOR 1185 def_bool y 1186 depends on X86_MCE_INTEL 1187 1188source "arch/x86/events/Kconfig" 1189 1190config X86_LEGACY_VM86 1191 bool "Legacy VM86 support" 1192 depends on X86_32 1193 ---help--- 1194 This option allows user programs to put the CPU into V8086 1195 mode, which is an 80286-era approximation of 16-bit real mode. 1196 1197 Some very old versions of X and/or vbetool require this option 1198 for user mode setting. Similarly, DOSEMU will use it if 1199 available to accelerate real mode DOS programs. However, any 1200 recent version of DOSEMU, X, or vbetool should be fully 1201 functional even without kernel VM86 support, as they will all 1202 fall back to software emulation. Nevertheless, if you are using 1203 a 16-bit DOS program where 16-bit performance matters, vm86 1204 mode might be faster than emulation and you might want to 1205 enable this option. 1206 1207 Note that any app that works on a 64-bit kernel is unlikely to 1208 need this option, as 64-bit kernels don't, and can't, support 1209 V8086 mode. This option is also unrelated to 16-bit protected 1210 mode and is not needed to run most 16-bit programs under Wine. 1211 1212 Enabling this option increases the complexity of the kernel 1213 and slows down exception handling a tiny bit. 1214 1215 If unsure, say N here. 1216 1217config VM86 1218 bool 1219 default X86_LEGACY_VM86 1220 1221config X86_16BIT 1222 bool "Enable support for 16-bit segments" if EXPERT 1223 default y 1224 depends on MODIFY_LDT_SYSCALL 1225 ---help--- 1226 This option is required by programs like Wine to run 16-bit 1227 protected mode legacy code on x86 processors. Disabling 1228 this option saves about 300 bytes on i386, or around 6K text 1229 plus 16K runtime memory on x86-64, 1230 1231config X86_ESPFIX32 1232 def_bool y 1233 depends on X86_16BIT && X86_32 1234 1235config X86_ESPFIX64 1236 def_bool y 1237 depends on X86_16BIT && X86_64 1238 1239config X86_VSYSCALL_EMULATION 1240 bool "Enable vsyscall emulation" if EXPERT 1241 default y 1242 depends on X86_64 1243 ---help--- 1244 This enables emulation of the legacy vsyscall page. Disabling 1245 it is roughly equivalent to booting with vsyscall=none, except 1246 that it will also disable the helpful warning if a program 1247 tries to use a vsyscall. With this option set to N, offending 1248 programs will just segfault, citing addresses of the form 1249 0xffffffffff600?00. 1250 1251 This option is required by many programs built before 2013, and 1252 care should be used even with newer programs if set to N. 1253 1254 Disabling this option saves about 7K of kernel size and 1255 possibly 4K of additional runtime pagetable memory. 1256 1257config TOSHIBA 1258 tristate "Toshiba Laptop support" 1259 depends on X86_32 1260 ---help--- 1261 This adds a driver to safely access the System Management Mode of 1262 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1263 not work on models with a Phoenix BIOS. The System Management Mode 1264 is used to set the BIOS and power saving options on Toshiba portables. 1265 1266 For information on utilities to make use of this driver see the 1267 Toshiba Linux utilities web site at: 1268 <http://www.buzzard.org.uk/toshiba/>. 1269 1270 Say Y if you intend to run this kernel on a Toshiba portable. 1271 Say N otherwise. 1272 1273config I8K 1274 tristate "Dell i8k legacy laptop support" 1275 select HWMON 1276 select SENSORS_DELL_SMM 1277 ---help--- 1278 This option enables legacy /proc/i8k userspace interface in hwmon 1279 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1280 temperature and allows controlling fan speeds of Dell laptops via 1281 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1282 it reports also power and hotkey status. For fan speed control is 1283 needed userspace package i8kutils. 1284 1285 Say Y if you intend to run this kernel on old Dell laptops or want to 1286 use userspace package i8kutils. 1287 Say N otherwise. 1288 1289config X86_REBOOTFIXUPS 1290 bool "Enable X86 board specific fixups for reboot" 1291 depends on X86_32 1292 ---help--- 1293 This enables chipset and/or board specific fixups to be done 1294 in order to get reboot to work correctly. This is only needed on 1295 some combinations of hardware and BIOS. The symptom, for which 1296 this config is intended, is when reboot ends with a stalled/hung 1297 system. 1298 1299 Currently, the only fixup is for the Geode machines using 1300 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1301 1302 Say Y if you want to enable the fixup. Currently, it's safe to 1303 enable this option even if you don't need it. 1304 Say N otherwise. 1305 1306config MICROCODE 1307 bool "CPU microcode loading support" 1308 default y 1309 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1310 select FW_LOADER 1311 ---help--- 1312 If you say Y here, you will be able to update the microcode on 1313 Intel and AMD processors. The Intel support is for the IA32 family, 1314 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1315 AMD support is for families 0x10 and later. You will obviously need 1316 the actual microcode binary data itself which is not shipped with 1317 the Linux kernel. 1318 1319 The preferred method to load microcode from a detached initrd is described 1320 in Documentation/x86/microcode.rst. For that you need to enable 1321 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1322 initrd for microcode blobs. 1323 1324 In addition, you can build the microcode into the kernel. For that you 1325 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1326 config option. 1327 1328config MICROCODE_INTEL 1329 bool "Intel microcode loading support" 1330 depends on MICROCODE 1331 default MICROCODE 1332 select FW_LOADER 1333 ---help--- 1334 This options enables microcode patch loading support for Intel 1335 processors. 1336 1337 For the current Intel microcode data package go to 1338 <https://downloadcenter.intel.com> and search for 1339 'Linux Processor Microcode Data File'. 1340 1341config MICROCODE_AMD 1342 bool "AMD microcode loading support" 1343 depends on MICROCODE 1344 select FW_LOADER 1345 ---help--- 1346 If you select this option, microcode patch loading support for AMD 1347 processors will be enabled. 1348 1349config MICROCODE_OLD_INTERFACE 1350 bool "Ancient loading interface (DEPRECATED)" 1351 default n 1352 depends on MICROCODE 1353 ---help--- 1354 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1355 which was used by userspace tools like iucode_tool and microcode.ctl. 1356 It is inadequate because it runs too late to be able to properly 1357 load microcode on a machine and it needs special tools. Instead, you 1358 should've switched to the early loading method with the initrd or 1359 builtin microcode by now: Documentation/x86/microcode.rst 1360 1361config X86_MSR 1362 tristate "/dev/cpu/*/msr - Model-specific register support" 1363 ---help--- 1364 This device gives privileged processes access to the x86 1365 Model-Specific Registers (MSRs). It is a character device with 1366 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1367 MSR accesses are directed to a specific CPU on multi-processor 1368 systems. 1369 1370config X86_CPUID 1371 tristate "/dev/cpu/*/cpuid - CPU information support" 1372 ---help--- 1373 This device gives processes access to the x86 CPUID instruction to 1374 be executed on a specific processor. It is a character device 1375 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1376 /dev/cpu/31/cpuid. 1377 1378choice 1379 prompt "High Memory Support" 1380 default HIGHMEM4G 1381 depends on X86_32 1382 1383config NOHIGHMEM 1384 bool "off" 1385 ---help--- 1386 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1387 However, the address space of 32-bit x86 processors is only 4 1388 Gigabytes large. That means that, if you have a large amount of 1389 physical memory, not all of it can be "permanently mapped" by the 1390 kernel. The physical memory that's not permanently mapped is called 1391 "high memory". 1392 1393 If you are compiling a kernel which will never run on a machine with 1394 more than 1 Gigabyte total physical RAM, answer "off" here (default 1395 choice and suitable for most users). This will result in a "3GB/1GB" 1396 split: 3GB are mapped so that each process sees a 3GB virtual memory 1397 space and the remaining part of the 4GB virtual memory space is used 1398 by the kernel to permanently map as much physical memory as 1399 possible. 1400 1401 If the machine has between 1 and 4 Gigabytes physical RAM, then 1402 answer "4GB" here. 1403 1404 If more than 4 Gigabytes is used then answer "64GB" here. This 1405 selection turns Intel PAE (Physical Address Extension) mode on. 1406 PAE implements 3-level paging on IA32 processors. PAE is fully 1407 supported by Linux, PAE mode is implemented on all recent Intel 1408 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1409 then the kernel will not boot on CPUs that don't support PAE! 1410 1411 The actual amount of total physical memory will either be 1412 auto detected or can be forced by using a kernel command line option 1413 such as "mem=256M". (Try "man bootparam" or see the documentation of 1414 your boot loader (lilo or loadlin) about how to pass options to the 1415 kernel at boot time.) 1416 1417 If unsure, say "off". 1418 1419config HIGHMEM4G 1420 bool "4GB" 1421 ---help--- 1422 Select this if you have a 32-bit processor and between 1 and 4 1423 gigabytes of physical RAM. 1424 1425config HIGHMEM64G 1426 bool "64GB" 1427 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1428 select X86_PAE 1429 ---help--- 1430 Select this if you have a 32-bit processor and more than 4 1431 gigabytes of physical RAM. 1432 1433endchoice 1434 1435choice 1436 prompt "Memory split" if EXPERT 1437 default VMSPLIT_3G 1438 depends on X86_32 1439 ---help--- 1440 Select the desired split between kernel and user memory. 1441 1442 If the address range available to the kernel is less than the 1443 physical memory installed, the remaining memory will be available 1444 as "high memory". Accessing high memory is a little more costly 1445 than low memory, as it needs to be mapped into the kernel first. 1446 Note that increasing the kernel address space limits the range 1447 available to user programs, making the address space there 1448 tighter. Selecting anything other than the default 3G/1G split 1449 will also likely make your kernel incompatible with binary-only 1450 kernel modules. 1451 1452 If you are not absolutely sure what you are doing, leave this 1453 option alone! 1454 1455 config VMSPLIT_3G 1456 bool "3G/1G user/kernel split" 1457 config VMSPLIT_3G_OPT 1458 depends on !X86_PAE 1459 bool "3G/1G user/kernel split (for full 1G low memory)" 1460 config VMSPLIT_2G 1461 bool "2G/2G user/kernel split" 1462 config VMSPLIT_2G_OPT 1463 depends on !X86_PAE 1464 bool "2G/2G user/kernel split (for full 2G low memory)" 1465 config VMSPLIT_1G 1466 bool "1G/3G user/kernel split" 1467endchoice 1468 1469config PAGE_OFFSET 1470 hex 1471 default 0xB0000000 if VMSPLIT_3G_OPT 1472 default 0x80000000 if VMSPLIT_2G 1473 default 0x78000000 if VMSPLIT_2G_OPT 1474 default 0x40000000 if VMSPLIT_1G 1475 default 0xC0000000 1476 depends on X86_32 1477 1478config HIGHMEM 1479 def_bool y 1480 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1481 1482config X86_PAE 1483 bool "PAE (Physical Address Extension) Support" 1484 depends on X86_32 && !HIGHMEM4G 1485 select PHYS_ADDR_T_64BIT 1486 select SWIOTLB 1487 ---help--- 1488 PAE is required for NX support, and furthermore enables 1489 larger swapspace support for non-overcommit purposes. It 1490 has the cost of more pagetable lookup overhead, and also 1491 consumes more pagetable space per process. 1492 1493config X86_5LEVEL 1494 bool "Enable 5-level page tables support" 1495 select DYNAMIC_MEMORY_LAYOUT 1496 select SPARSEMEM_VMEMMAP 1497 depends on X86_64 1498 ---help--- 1499 5-level paging enables access to larger address space: 1500 upto 128 PiB of virtual address space and 4 PiB of 1501 physical address space. 1502 1503 It will be supported by future Intel CPUs. 1504 1505 A kernel with the option enabled can be booted on machines that 1506 support 4- or 5-level paging. 1507 1508 See Documentation/x86/x86_64/5level-paging.rst for more 1509 information. 1510 1511 Say N if unsure. 1512 1513config X86_DIRECT_GBPAGES 1514 def_bool y 1515 depends on X86_64 1516 ---help--- 1517 Certain kernel features effectively disable kernel 1518 linear 1 GB mappings (even if the CPU otherwise 1519 supports them), so don't confuse the user by printing 1520 that we have them enabled. 1521 1522config X86_CPA_STATISTICS 1523 bool "Enable statistic for Change Page Attribute" 1524 depends on DEBUG_FS 1525 ---help--- 1526 Expose statistics about the Change Page Attribute mechanims, which 1527 helps to determine the effectiveness of preserving large and huge 1528 page mappings when mapping protections are changed. 1529 1530config AMD_MEM_ENCRYPT 1531 bool "AMD Secure Memory Encryption (SME) support" 1532 depends on X86_64 && CPU_SUP_AMD 1533 select DYNAMIC_PHYSICAL_MASK 1534 select ARCH_USE_MEMREMAP_PROT 1535 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1536 ---help--- 1537 Say yes to enable support for the encryption of system memory. 1538 This requires an AMD processor that supports Secure Memory 1539 Encryption (SME). 1540 1541config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1542 bool "Activate AMD Secure Memory Encryption (SME) by default" 1543 default y 1544 depends on AMD_MEM_ENCRYPT 1545 ---help--- 1546 Say yes to have system memory encrypted by default if running on 1547 an AMD processor that supports Secure Memory Encryption (SME). 1548 1549 If set to Y, then the encryption of system memory can be 1550 deactivated with the mem_encrypt=off command line option. 1551 1552 If set to N, then the encryption of system memory can be 1553 activated with the mem_encrypt=on command line option. 1554 1555# Common NUMA Features 1556config NUMA 1557 bool "Numa Memory Allocation and Scheduler Support" 1558 depends on SMP 1559 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1560 default y if X86_BIGSMP 1561 ---help--- 1562 Enable NUMA (Non Uniform Memory Access) support. 1563 1564 The kernel will try to allocate memory used by a CPU on the 1565 local memory controller of the CPU and add some more 1566 NUMA awareness to the kernel. 1567 1568 For 64-bit this is recommended if the system is Intel Core i7 1569 (or later), AMD Opteron, or EM64T NUMA. 1570 1571 For 32-bit this is only needed if you boot a 32-bit 1572 kernel on a 64-bit NUMA platform. 1573 1574 Otherwise, you should say N. 1575 1576config AMD_NUMA 1577 def_bool y 1578 prompt "Old style AMD Opteron NUMA detection" 1579 depends on X86_64 && NUMA && PCI 1580 ---help--- 1581 Enable AMD NUMA node topology detection. You should say Y here if 1582 you have a multi processor AMD system. This uses an old method to 1583 read the NUMA configuration directly from the builtin Northbridge 1584 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1585 which also takes priority if both are compiled in. 1586 1587config X86_64_ACPI_NUMA 1588 def_bool y 1589 prompt "ACPI NUMA detection" 1590 depends on X86_64 && NUMA && ACPI && PCI 1591 select ACPI_NUMA 1592 ---help--- 1593 Enable ACPI SRAT based node topology detection. 1594 1595# Some NUMA nodes have memory ranges that span 1596# other nodes. Even though a pfn is valid and 1597# between a node's start and end pfns, it may not 1598# reside on that node. See memmap_init_zone() 1599# for details. 1600config NODES_SPAN_OTHER_NODES 1601 def_bool y 1602 depends on X86_64_ACPI_NUMA 1603 1604config NUMA_EMU 1605 bool "NUMA emulation" 1606 depends on NUMA 1607 ---help--- 1608 Enable NUMA emulation. A flat machine will be split 1609 into virtual nodes when booted with "numa=fake=N", where N is the 1610 number of nodes. This is only useful for debugging. 1611 1612config NODES_SHIFT 1613 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1614 range 1 10 1615 default "10" if MAXSMP 1616 default "6" if X86_64 1617 default "3" 1618 depends on NEED_MULTIPLE_NODES 1619 ---help--- 1620 Specify the maximum number of NUMA Nodes available on the target 1621 system. Increases memory reserved to accommodate various tables. 1622 1623config ARCH_HAVE_MEMORY_PRESENT 1624 def_bool y 1625 depends on X86_32 && DISCONTIGMEM 1626 1627config ARCH_FLATMEM_ENABLE 1628 def_bool y 1629 depends on X86_32 && !NUMA 1630 1631config ARCH_DISCONTIGMEM_ENABLE 1632 def_bool n 1633 depends on NUMA && X86_32 1634 depends on BROKEN 1635 1636config ARCH_SPARSEMEM_ENABLE 1637 def_bool y 1638 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1639 select SPARSEMEM_STATIC if X86_32 1640 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1641 1642config ARCH_SPARSEMEM_DEFAULT 1643 def_bool X86_64 || (NUMA && X86_32) 1644 1645config ARCH_SELECT_MEMORY_MODEL 1646 def_bool y 1647 depends on ARCH_SPARSEMEM_ENABLE 1648 1649config ARCH_MEMORY_PROBE 1650 bool "Enable sysfs memory/probe interface" 1651 depends on X86_64 && MEMORY_HOTPLUG 1652 help 1653 This option enables a sysfs memory/probe interface for testing. 1654 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1655 If you are unsure how to answer this question, answer N. 1656 1657config ARCH_PROC_KCORE_TEXT 1658 def_bool y 1659 depends on X86_64 && PROC_KCORE 1660 1661config ILLEGAL_POINTER_VALUE 1662 hex 1663 default 0 if X86_32 1664 default 0xdead000000000000 if X86_64 1665 1666config X86_PMEM_LEGACY_DEVICE 1667 bool 1668 1669config X86_PMEM_LEGACY 1670 tristate "Support non-standard NVDIMMs and ADR protected memory" 1671 depends on PHYS_ADDR_T_64BIT 1672 depends on BLK_DEV 1673 select X86_PMEM_LEGACY_DEVICE 1674 select LIBNVDIMM 1675 help 1676 Treat memory marked using the non-standard e820 type of 12 as used 1677 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1678 The kernel will offer these regions to the 'pmem' driver so 1679 they can be used for persistent storage. 1680 1681 Say Y if unsure. 1682 1683config HIGHPTE 1684 bool "Allocate 3rd-level pagetables from highmem" 1685 depends on HIGHMEM 1686 ---help--- 1687 The VM uses one page table entry for each page of physical memory. 1688 For systems with a lot of RAM, this can be wasteful of precious 1689 low memory. Setting this option will put user-space page table 1690 entries in high memory. 1691 1692config X86_CHECK_BIOS_CORRUPTION 1693 bool "Check for low memory corruption" 1694 ---help--- 1695 Periodically check for memory corruption in low memory, which 1696 is suspected to be caused by BIOS. Even when enabled in the 1697 configuration, it is disabled at runtime. Enable it by 1698 setting "memory_corruption_check=1" on the kernel command 1699 line. By default it scans the low 64k of memory every 60 1700 seconds; see the memory_corruption_check_size and 1701 memory_corruption_check_period parameters in 1702 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1703 1704 When enabled with the default parameters, this option has 1705 almost no overhead, as it reserves a relatively small amount 1706 of memory and scans it infrequently. It both detects corruption 1707 and prevents it from affecting the running system. 1708 1709 It is, however, intended as a diagnostic tool; if repeatable 1710 BIOS-originated corruption always affects the same memory, 1711 you can use memmap= to prevent the kernel from using that 1712 memory. 1713 1714config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1715 bool "Set the default setting of memory_corruption_check" 1716 depends on X86_CHECK_BIOS_CORRUPTION 1717 default y 1718 ---help--- 1719 Set whether the default state of memory_corruption_check is 1720 on or off. 1721 1722config X86_RESERVE_LOW 1723 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1724 default 64 1725 range 4 640 1726 ---help--- 1727 Specify the amount of low memory to reserve for the BIOS. 1728 1729 The first page contains BIOS data structures that the kernel 1730 must not use, so that page must always be reserved. 1731 1732 By default we reserve the first 64K of physical RAM, as a 1733 number of BIOSes are known to corrupt that memory range 1734 during events such as suspend/resume or monitor cable 1735 insertion, so it must not be used by the kernel. 1736 1737 You can set this to 4 if you are absolutely sure that you 1738 trust the BIOS to get all its memory reservations and usages 1739 right. If you know your BIOS have problems beyond the 1740 default 64K area, you can set this to 640 to avoid using the 1741 entire low memory range. 1742 1743 If you have doubts about the BIOS (e.g. suspend/resume does 1744 not work or there's kernel crashes after certain hardware 1745 hotplug events) then you might want to enable 1746 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1747 typical corruption patterns. 1748 1749 Leave this to the default value of 64 if you are unsure. 1750 1751config MATH_EMULATION 1752 bool 1753 depends on MODIFY_LDT_SYSCALL 1754 prompt "Math emulation" if X86_32 1755 ---help--- 1756 Linux can emulate a math coprocessor (used for floating point 1757 operations) if you don't have one. 486DX and Pentium processors have 1758 a math coprocessor built in, 486SX and 386 do not, unless you added 1759 a 487DX or 387, respectively. (The messages during boot time can 1760 give you some hints here ["man dmesg"].) Everyone needs either a 1761 coprocessor or this emulation. 1762 1763 If you don't have a math coprocessor, you need to say Y here; if you 1764 say Y here even though you have a coprocessor, the coprocessor will 1765 be used nevertheless. (This behavior can be changed with the kernel 1766 command line option "no387", which comes handy if your coprocessor 1767 is broken. Try "man bootparam" or see the documentation of your boot 1768 loader (lilo or loadlin) about how to pass options to the kernel at 1769 boot time.) This means that it is a good idea to say Y here if you 1770 intend to use this kernel on different machines. 1771 1772 More information about the internals of the Linux math coprocessor 1773 emulation can be found in <file:arch/x86/math-emu/README>. 1774 1775 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1776 kernel, it won't hurt. 1777 1778config MTRR 1779 def_bool y 1780 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1781 ---help--- 1782 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1783 the Memory Type Range Registers (MTRRs) may be used to control 1784 processor access to memory ranges. This is most useful if you have 1785 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1786 allows bus write transfers to be combined into a larger transfer 1787 before bursting over the PCI/AGP bus. This can increase performance 1788 of image write operations 2.5 times or more. Saying Y here creates a 1789 /proc/mtrr file which may be used to manipulate your processor's 1790 MTRRs. Typically the X server should use this. 1791 1792 This code has a reasonably generic interface so that similar 1793 control registers on other processors can be easily supported 1794 as well: 1795 1796 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1797 Registers (ARRs) which provide a similar functionality to MTRRs. For 1798 these, the ARRs are used to emulate the MTRRs. 1799 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1800 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1801 write-combining. All of these processors are supported by this code 1802 and it makes sense to say Y here if you have one of them. 1803 1804 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1805 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1806 can lead to all sorts of problems, so it's good to say Y here. 1807 1808 You can safely say Y even if your machine doesn't have MTRRs, you'll 1809 just add about 9 KB to your kernel. 1810 1811 See <file:Documentation/x86/mtrr.rst> for more information. 1812 1813config MTRR_SANITIZER 1814 def_bool y 1815 prompt "MTRR cleanup support" 1816 depends on MTRR 1817 ---help--- 1818 Convert MTRR layout from continuous to discrete, so X drivers can 1819 add writeback entries. 1820 1821 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1822 The largest mtrr entry size for a continuous block can be set with 1823 mtrr_chunk_size. 1824 1825 If unsure, say Y. 1826 1827config MTRR_SANITIZER_ENABLE_DEFAULT 1828 int "MTRR cleanup enable value (0-1)" 1829 range 0 1 1830 default "0" 1831 depends on MTRR_SANITIZER 1832 ---help--- 1833 Enable mtrr cleanup default value 1834 1835config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1836 int "MTRR cleanup spare reg num (0-7)" 1837 range 0 7 1838 default "1" 1839 depends on MTRR_SANITIZER 1840 ---help--- 1841 mtrr cleanup spare entries default, it can be changed via 1842 mtrr_spare_reg_nr=N on the kernel command line. 1843 1844config X86_PAT 1845 def_bool y 1846 prompt "x86 PAT support" if EXPERT 1847 depends on MTRR 1848 ---help--- 1849 Use PAT attributes to setup page level cache control. 1850 1851 PATs are the modern equivalents of MTRRs and are much more 1852 flexible than MTRRs. 1853 1854 Say N here if you see bootup problems (boot crash, boot hang, 1855 spontaneous reboots) or a non-working video driver. 1856 1857 If unsure, say Y. 1858 1859config ARCH_USES_PG_UNCACHED 1860 def_bool y 1861 depends on X86_PAT 1862 1863config ARCH_RANDOM 1864 def_bool y 1865 prompt "x86 architectural random number generator" if EXPERT 1866 ---help--- 1867 Enable the x86 architectural RDRAND instruction 1868 (Intel Bull Mountain technology) to generate random numbers. 1869 If supported, this is a high bandwidth, cryptographically 1870 secure hardware random number generator. 1871 1872config X86_SMAP 1873 def_bool y 1874 prompt "Supervisor Mode Access Prevention" if EXPERT 1875 ---help--- 1876 Supervisor Mode Access Prevention (SMAP) is a security 1877 feature in newer Intel processors. There is a small 1878 performance cost if this enabled and turned on; there is 1879 also a small increase in the kernel size if this is enabled. 1880 1881 If unsure, say Y. 1882 1883config X86_INTEL_UMIP 1884 def_bool y 1885 depends on CPU_SUP_INTEL 1886 prompt "Intel User Mode Instruction Prevention" if EXPERT 1887 ---help--- 1888 The User Mode Instruction Prevention (UMIP) is a security 1889 feature in newer Intel processors. If enabled, a general 1890 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1891 or STR instructions are executed in user mode. These instructions 1892 unnecessarily expose information about the hardware state. 1893 1894 The vast majority of applications do not use these instructions. 1895 For the very few that do, software emulation is provided in 1896 specific cases in protected and virtual-8086 modes. Emulated 1897 results are dummy. 1898 1899config X86_INTEL_MPX 1900 prompt "Intel MPX (Memory Protection Extensions)" 1901 def_bool n 1902 # Note: only available in 64-bit mode due to VMA flags shortage 1903 depends on CPU_SUP_INTEL && X86_64 1904 select ARCH_USES_HIGH_VMA_FLAGS 1905 ---help--- 1906 MPX provides hardware features that can be used in 1907 conjunction with compiler-instrumented code to check 1908 memory references. It is designed to detect buffer 1909 overflow or underflow bugs. 1910 1911 This option enables running applications which are 1912 instrumented or otherwise use MPX. It does not use MPX 1913 itself inside the kernel or to protect the kernel 1914 against bad memory references. 1915 1916 Enabling this option will make the kernel larger: 1917 ~8k of kernel text and 36 bytes of data on a 64-bit 1918 defconfig. It adds a long to the 'mm_struct' which 1919 will increase the kernel memory overhead of each 1920 process and adds some branches to paths used during 1921 exec() and munmap(). 1922 1923 For details, see Documentation/x86/intel_mpx.rst 1924 1925 If unsure, say N. 1926 1927config X86_INTEL_MEMORY_PROTECTION_KEYS 1928 prompt "Intel Memory Protection Keys" 1929 def_bool y 1930 # Note: only available in 64-bit mode 1931 depends on CPU_SUP_INTEL && X86_64 1932 select ARCH_USES_HIGH_VMA_FLAGS 1933 select ARCH_HAS_PKEYS 1934 ---help--- 1935 Memory Protection Keys provides a mechanism for enforcing 1936 page-based protections, but without requiring modification of the 1937 page tables when an application changes protection domains. 1938 1939 For details, see Documentation/core-api/protection-keys.rst 1940 1941 If unsure, say y. 1942 1943choice 1944 prompt "TSX enable mode" 1945 depends on CPU_SUP_INTEL 1946 default X86_INTEL_TSX_MODE_OFF 1947 help 1948 Intel's TSX (Transactional Synchronization Extensions) feature 1949 allows to optimize locking protocols through lock elision which 1950 can lead to a noticeable performance boost. 1951 1952 On the other hand it has been shown that TSX can be exploited 1953 to form side channel attacks (e.g. TAA) and chances are there 1954 will be more of those attacks discovered in the future. 1955 1956 Therefore TSX is not enabled by default (aka tsx=off). An admin 1957 might override this decision by tsx=on the command line parameter. 1958 Even with TSX enabled, the kernel will attempt to enable the best 1959 possible TAA mitigation setting depending on the microcode available 1960 for the particular machine. 1961 1962 This option allows to set the default tsx mode between tsx=on, =off 1963 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1964 details. 1965 1966 Say off if not sure, auto if TSX is in use but it should be used on safe 1967 platforms or on if TSX is in use and the security aspect of tsx is not 1968 relevant. 1969 1970config X86_INTEL_TSX_MODE_OFF 1971 bool "off" 1972 help 1973 TSX is disabled if possible - equals to tsx=off command line parameter. 1974 1975config X86_INTEL_TSX_MODE_ON 1976 bool "on" 1977 help 1978 TSX is always enabled on TSX capable HW - equals the tsx=on command 1979 line parameter. 1980 1981config X86_INTEL_TSX_MODE_AUTO 1982 bool "auto" 1983 help 1984 TSX is enabled on TSX capable HW that is believed to be safe against 1985 side channel attacks- equals the tsx=auto command line parameter. 1986endchoice 1987 1988config EFI 1989 bool "EFI runtime service support" 1990 depends on ACPI 1991 select UCS2_STRING 1992 select EFI_RUNTIME_WRAPPERS 1993 ---help--- 1994 This enables the kernel to use EFI runtime services that are 1995 available (such as the EFI variable services). 1996 1997 This option is only useful on systems that have EFI firmware. 1998 In addition, you should use the latest ELILO loader available 1999 at <http://elilo.sourceforge.net> in order to take advantage 2000 of EFI runtime services. However, even with this option, the 2001 resultant kernel should continue to boot on existing non-EFI 2002 platforms. 2003 2004config EFI_STUB 2005 bool "EFI stub support" 2006 depends on EFI && !X86_USE_3DNOW 2007 select RELOCATABLE 2008 ---help--- 2009 This kernel feature allows a bzImage to be loaded directly 2010 by EFI firmware without the use of a bootloader. 2011 2012 See Documentation/admin-guide/efi-stub.rst for more information. 2013 2014config EFI_MIXED 2015 bool "EFI mixed-mode support" 2016 depends on EFI_STUB && X86_64 2017 ---help--- 2018 Enabling this feature allows a 64-bit kernel to be booted 2019 on a 32-bit firmware, provided that your CPU supports 64-bit 2020 mode. 2021 2022 Note that it is not possible to boot a mixed-mode enabled 2023 kernel via the EFI boot stub - a bootloader that supports 2024 the EFI handover protocol must be used. 2025 2026 If unsure, say N. 2027 2028config SECCOMP 2029 def_bool y 2030 prompt "Enable seccomp to safely compute untrusted bytecode" 2031 ---help--- 2032 This kernel feature is useful for number crunching applications 2033 that may need to compute untrusted bytecode during their 2034 execution. By using pipes or other transports made available to 2035 the process as file descriptors supporting the read/write 2036 syscalls, it's possible to isolate those applications in 2037 their own address space using seccomp. Once seccomp is 2038 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 2039 and the task is only allowed to execute a few safe syscalls 2040 defined by each seccomp mode. 2041 2042 If unsure, say Y. Only embedded should say N here. 2043 2044source "kernel/Kconfig.hz" 2045 2046config KEXEC 2047 bool "kexec system call" 2048 select KEXEC_CORE 2049 ---help--- 2050 kexec is a system call that implements the ability to shutdown your 2051 current kernel, and to start another kernel. It is like a reboot 2052 but it is independent of the system firmware. And like a reboot 2053 you can start any kernel with it, not just Linux. 2054 2055 The name comes from the similarity to the exec system call. 2056 2057 It is an ongoing process to be certain the hardware in a machine 2058 is properly shutdown, so do not be surprised if this code does not 2059 initially work for you. As of this writing the exact hardware 2060 interface is strongly in flux, so no good recommendation can be 2061 made. 2062 2063config KEXEC_FILE 2064 bool "kexec file based system call" 2065 select KEXEC_CORE 2066 select BUILD_BIN2C 2067 depends on X86_64 2068 depends on CRYPTO=y 2069 depends on CRYPTO_SHA256=y 2070 ---help--- 2071 This is new version of kexec system call. This system call is 2072 file based and takes file descriptors as system call argument 2073 for kernel and initramfs as opposed to list of segments as 2074 accepted by previous system call. 2075 2076config ARCH_HAS_KEXEC_PURGATORY 2077 def_bool KEXEC_FILE 2078 2079config KEXEC_SIG 2080 bool "Verify kernel signature during kexec_file_load() syscall" 2081 depends on KEXEC_FILE 2082 ---help--- 2083 2084 This option makes the kexec_file_load() syscall check for a valid 2085 signature of the kernel image. The image can still be loaded without 2086 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2087 there's a signature that we can check, then it must be valid. 2088 2089 In addition to this option, you need to enable signature 2090 verification for the corresponding kernel image type being 2091 loaded in order for this to work. 2092 2093config KEXEC_SIG_FORCE 2094 bool "Require a valid signature in kexec_file_load() syscall" 2095 depends on KEXEC_SIG 2096 ---help--- 2097 This option makes kernel signature verification mandatory for 2098 the kexec_file_load() syscall. 2099 2100config KEXEC_BZIMAGE_VERIFY_SIG 2101 bool "Enable bzImage signature verification support" 2102 depends on KEXEC_SIG 2103 depends on SIGNED_PE_FILE_VERIFICATION 2104 select SYSTEM_TRUSTED_KEYRING 2105 ---help--- 2106 Enable bzImage signature verification support. 2107 2108config CRASH_DUMP 2109 bool "kernel crash dumps" 2110 depends on X86_64 || (X86_32 && HIGHMEM) 2111 ---help--- 2112 Generate crash dump after being started by kexec. 2113 This should be normally only set in special crash dump kernels 2114 which are loaded in the main kernel with kexec-tools into 2115 a specially reserved region and then later executed after 2116 a crash by kdump/kexec. The crash dump kernel must be compiled 2117 to a memory address not used by the main kernel or BIOS using 2118 PHYSICAL_START, or it must be built as a relocatable image 2119 (CONFIG_RELOCATABLE=y). 2120 For more details see Documentation/admin-guide/kdump/kdump.rst 2121 2122config KEXEC_JUMP 2123 bool "kexec jump" 2124 depends on KEXEC && HIBERNATION 2125 ---help--- 2126 Jump between original kernel and kexeced kernel and invoke 2127 code in physical address mode via KEXEC 2128 2129config PHYSICAL_START 2130 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2131 default "0x1000000" 2132 ---help--- 2133 This gives the physical address where the kernel is loaded. 2134 2135 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2136 bzImage will decompress itself to above physical address and 2137 run from there. Otherwise, bzImage will run from the address where 2138 it has been loaded by the boot loader and will ignore above physical 2139 address. 2140 2141 In normal kdump cases one does not have to set/change this option 2142 as now bzImage can be compiled as a completely relocatable image 2143 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2144 address. This option is mainly useful for the folks who don't want 2145 to use a bzImage for capturing the crash dump and want to use a 2146 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2147 to be specifically compiled to run from a specific memory area 2148 (normally a reserved region) and this option comes handy. 2149 2150 So if you are using bzImage for capturing the crash dump, 2151 leave the value here unchanged to 0x1000000 and set 2152 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2153 for capturing the crash dump change this value to start of 2154 the reserved region. In other words, it can be set based on 2155 the "X" value as specified in the "crashkernel=YM@XM" 2156 command line boot parameter passed to the panic-ed 2157 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2158 for more details about crash dumps. 2159 2160 Usage of bzImage for capturing the crash dump is recommended as 2161 one does not have to build two kernels. Same kernel can be used 2162 as production kernel and capture kernel. Above option should have 2163 gone away after relocatable bzImage support is introduced. But it 2164 is present because there are users out there who continue to use 2165 vmlinux for dump capture. This option should go away down the 2166 line. 2167 2168 Don't change this unless you know what you are doing. 2169 2170config RELOCATABLE 2171 bool "Build a relocatable kernel" 2172 default y 2173 ---help--- 2174 This builds a kernel image that retains relocation information 2175 so it can be loaded someplace besides the default 1MB. 2176 The relocations tend to make the kernel binary about 10% larger, 2177 but are discarded at runtime. 2178 2179 One use is for the kexec on panic case where the recovery kernel 2180 must live at a different physical address than the primary 2181 kernel. 2182 2183 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2184 it has been loaded at and the compile time physical address 2185 (CONFIG_PHYSICAL_START) is used as the minimum location. 2186 2187config RANDOMIZE_BASE 2188 bool "Randomize the address of the kernel image (KASLR)" 2189 depends on RELOCATABLE 2190 default y 2191 ---help--- 2192 In support of Kernel Address Space Layout Randomization (KASLR), 2193 this randomizes the physical address at which the kernel image 2194 is decompressed and the virtual address where the kernel 2195 image is mapped, as a security feature that deters exploit 2196 attempts relying on knowledge of the location of kernel 2197 code internals. 2198 2199 On 64-bit, the kernel physical and virtual addresses are 2200 randomized separately. The physical address will be anywhere 2201 between 16MB and the top of physical memory (up to 64TB). The 2202 virtual address will be randomized from 16MB up to 1GB (9 bits 2203 of entropy). Note that this also reduces the memory space 2204 available to kernel modules from 1.5GB to 1GB. 2205 2206 On 32-bit, the kernel physical and virtual addresses are 2207 randomized together. They will be randomized from 16MB up to 2208 512MB (8 bits of entropy). 2209 2210 Entropy is generated using the RDRAND instruction if it is 2211 supported. If RDTSC is supported, its value is mixed into 2212 the entropy pool as well. If neither RDRAND nor RDTSC are 2213 supported, then entropy is read from the i8254 timer. The 2214 usable entropy is limited by the kernel being built using 2215 2GB addressing, and that PHYSICAL_ALIGN must be at a 2216 minimum of 2MB. As a result, only 10 bits of entropy are 2217 theoretically possible, but the implementations are further 2218 limited due to memory layouts. 2219 2220 If unsure, say Y. 2221 2222# Relocation on x86 needs some additional build support 2223config X86_NEED_RELOCS 2224 def_bool y 2225 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2226 2227config PHYSICAL_ALIGN 2228 hex "Alignment value to which kernel should be aligned" 2229 default "0x200000" 2230 range 0x2000 0x1000000 if X86_32 2231 range 0x200000 0x1000000 if X86_64 2232 ---help--- 2233 This value puts the alignment restrictions on physical address 2234 where kernel is loaded and run from. Kernel is compiled for an 2235 address which meets above alignment restriction. 2236 2237 If bootloader loads the kernel at a non-aligned address and 2238 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2239 address aligned to above value and run from there. 2240 2241 If bootloader loads the kernel at a non-aligned address and 2242 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2243 load address and decompress itself to the address it has been 2244 compiled for and run from there. The address for which kernel is 2245 compiled already meets above alignment restrictions. Hence the 2246 end result is that kernel runs from a physical address meeting 2247 above alignment restrictions. 2248 2249 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2250 this value must be a multiple of 0x200000. 2251 2252 Don't change this unless you know what you are doing. 2253 2254config DYNAMIC_MEMORY_LAYOUT 2255 bool 2256 ---help--- 2257 This option makes base addresses of vmalloc and vmemmap as well as 2258 __PAGE_OFFSET movable during boot. 2259 2260config RANDOMIZE_MEMORY 2261 bool "Randomize the kernel memory sections" 2262 depends on X86_64 2263 depends on RANDOMIZE_BASE 2264 select DYNAMIC_MEMORY_LAYOUT 2265 default RANDOMIZE_BASE 2266 ---help--- 2267 Randomizes the base virtual address of kernel memory sections 2268 (physical memory mapping, vmalloc & vmemmap). This security feature 2269 makes exploits relying on predictable memory locations less reliable. 2270 2271 The order of allocations remains unchanged. Entropy is generated in 2272 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2273 configuration have in average 30,000 different possible virtual 2274 addresses for each memory section. 2275 2276 If unsure, say Y. 2277 2278config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2279 hex "Physical memory mapping padding" if EXPERT 2280 depends on RANDOMIZE_MEMORY 2281 default "0xa" if MEMORY_HOTPLUG 2282 default "0x0" 2283 range 0x1 0x40 if MEMORY_HOTPLUG 2284 range 0x0 0x40 2285 ---help--- 2286 Define the padding in terabytes added to the existing physical 2287 memory size during kernel memory randomization. It is useful 2288 for memory hotplug support but reduces the entropy available for 2289 address randomization. 2290 2291 If unsure, leave at the default value. 2292 2293config HOTPLUG_CPU 2294 def_bool y 2295 depends on SMP 2296 2297config BOOTPARAM_HOTPLUG_CPU0 2298 bool "Set default setting of cpu0_hotpluggable" 2299 depends on HOTPLUG_CPU 2300 ---help--- 2301 Set whether default state of cpu0_hotpluggable is on or off. 2302 2303 Say Y here to enable CPU0 hotplug by default. If this switch 2304 is turned on, there is no need to give cpu0_hotplug kernel 2305 parameter and the CPU0 hotplug feature is enabled by default. 2306 2307 Please note: there are two known CPU0 dependencies if you want 2308 to enable the CPU0 hotplug feature either by this switch or by 2309 cpu0_hotplug kernel parameter. 2310 2311 First, resume from hibernate or suspend always starts from CPU0. 2312 So hibernate and suspend are prevented if CPU0 is offline. 2313 2314 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2315 offline if any interrupt can not migrate out of CPU0. There may 2316 be other CPU0 dependencies. 2317 2318 Please make sure the dependencies are under your control before 2319 you enable this feature. 2320 2321 Say N if you don't want to enable CPU0 hotplug feature by default. 2322 You still can enable the CPU0 hotplug feature at boot by kernel 2323 parameter cpu0_hotplug. 2324 2325config DEBUG_HOTPLUG_CPU0 2326 def_bool n 2327 prompt "Debug CPU0 hotplug" 2328 depends on HOTPLUG_CPU 2329 ---help--- 2330 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2331 soon as possible and boots up userspace with CPU0 offlined. User 2332 can online CPU0 back after boot time. 2333 2334 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2335 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2336 compilation or giving cpu0_hotplug kernel parameter at boot. 2337 2338 If unsure, say N. 2339 2340config COMPAT_VDSO 2341 def_bool n 2342 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2343 depends on COMPAT_32 2344 ---help--- 2345 Certain buggy versions of glibc will crash if they are 2346 presented with a 32-bit vDSO that is not mapped at the address 2347 indicated in its segment table. 2348 2349 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2350 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2351 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2352 the only released version with the bug, but OpenSUSE 9 2353 contains a buggy "glibc 2.3.2". 2354 2355 The symptom of the bug is that everything crashes on startup, saying: 2356 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2357 2358 Saying Y here changes the default value of the vdso32 boot 2359 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2360 This works around the glibc bug but hurts performance. 2361 2362 If unsure, say N: if you are compiling your own kernel, you 2363 are unlikely to be using a buggy version of glibc. 2364 2365choice 2366 prompt "vsyscall table for legacy applications" 2367 depends on X86_64 2368 default LEGACY_VSYSCALL_XONLY 2369 help 2370 Legacy user code that does not know how to find the vDSO expects 2371 to be able to issue three syscalls by calling fixed addresses in 2372 kernel space. Since this location is not randomized with ASLR, 2373 it can be used to assist security vulnerability exploitation. 2374 2375 This setting can be changed at boot time via the kernel command 2376 line parameter vsyscall=[emulate|xonly|none]. 2377 2378 On a system with recent enough glibc (2.14 or newer) and no 2379 static binaries, you can say None without a performance penalty 2380 to improve security. 2381 2382 If unsure, select "Emulate execution only". 2383 2384 config LEGACY_VSYSCALL_EMULATE 2385 bool "Full emulation" 2386 help 2387 The kernel traps and emulates calls into the fixed vsyscall 2388 address mapping. This makes the mapping non-executable, but 2389 it still contains readable known contents, which could be 2390 used in certain rare security vulnerability exploits. This 2391 configuration is recommended when using legacy userspace 2392 that still uses vsyscalls along with legacy binary 2393 instrumentation tools that require code to be readable. 2394 2395 An example of this type of legacy userspace is running 2396 Pin on an old binary that still uses vsyscalls. 2397 2398 config LEGACY_VSYSCALL_XONLY 2399 bool "Emulate execution only" 2400 help 2401 The kernel traps and emulates calls into the fixed vsyscall 2402 address mapping and does not allow reads. This 2403 configuration is recommended when userspace might use the 2404 legacy vsyscall area but support for legacy binary 2405 instrumentation of legacy code is not needed. It mitigates 2406 certain uses of the vsyscall area as an ASLR-bypassing 2407 buffer. 2408 2409 config LEGACY_VSYSCALL_NONE 2410 bool "None" 2411 help 2412 There will be no vsyscall mapping at all. This will 2413 eliminate any risk of ASLR bypass due to the vsyscall 2414 fixed address mapping. Attempts to use the vsyscalls 2415 will be reported to dmesg, so that either old or 2416 malicious userspace programs can be identified. 2417 2418endchoice 2419 2420config CMDLINE_BOOL 2421 bool "Built-in kernel command line" 2422 ---help--- 2423 Allow for specifying boot arguments to the kernel at 2424 build time. On some systems (e.g. embedded ones), it is 2425 necessary or convenient to provide some or all of the 2426 kernel boot arguments with the kernel itself (that is, 2427 to not rely on the boot loader to provide them.) 2428 2429 To compile command line arguments into the kernel, 2430 set this option to 'Y', then fill in the 2431 boot arguments in CONFIG_CMDLINE. 2432 2433 Systems with fully functional boot loaders (i.e. non-embedded) 2434 should leave this option set to 'N'. 2435 2436config CMDLINE 2437 string "Built-in kernel command string" 2438 depends on CMDLINE_BOOL 2439 default "" 2440 ---help--- 2441 Enter arguments here that should be compiled into the kernel 2442 image and used at boot time. If the boot loader provides a 2443 command line at boot time, it is appended to this string to 2444 form the full kernel command line, when the system boots. 2445 2446 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2447 change this behavior. 2448 2449 In most cases, the command line (whether built-in or provided 2450 by the boot loader) should specify the device for the root 2451 file system. 2452 2453config CMDLINE_OVERRIDE 2454 bool "Built-in command line overrides boot loader arguments" 2455 depends on CMDLINE_BOOL 2456 ---help--- 2457 Set this option to 'Y' to have the kernel ignore the boot loader 2458 command line, and use ONLY the built-in command line. 2459 2460 This is used to work around broken boot loaders. This should 2461 be set to 'N' under normal conditions. 2462 2463config MODIFY_LDT_SYSCALL 2464 bool "Enable the LDT (local descriptor table)" if EXPERT 2465 default y 2466 ---help--- 2467 Linux can allow user programs to install a per-process x86 2468 Local Descriptor Table (LDT) using the modify_ldt(2) system 2469 call. This is required to run 16-bit or segmented code such as 2470 DOSEMU or some Wine programs. It is also used by some very old 2471 threading libraries. 2472 2473 Enabling this feature adds a small amount of overhead to 2474 context switches and increases the low-level kernel attack 2475 surface. Disabling it removes the modify_ldt(2) system call. 2476 2477 Saying 'N' here may make sense for embedded or server kernels. 2478 2479source "kernel/livepatch/Kconfig" 2480 2481endmenu 2482 2483config ARCH_HAS_ADD_PAGES 2484 def_bool y 2485 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2486 2487config ARCH_ENABLE_MEMORY_HOTPLUG 2488 def_bool y 2489 depends on X86_64 || (X86_32 && HIGHMEM) 2490 2491config ARCH_ENABLE_MEMORY_HOTREMOVE 2492 def_bool y 2493 depends on MEMORY_HOTPLUG 2494 2495config USE_PERCPU_NUMA_NODE_ID 2496 def_bool y 2497 depends on NUMA 2498 2499config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2500 def_bool y 2501 depends on X86_64 || X86_PAE 2502 2503config ARCH_ENABLE_HUGEPAGE_MIGRATION 2504 def_bool y 2505 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2506 2507config ARCH_ENABLE_THP_MIGRATION 2508 def_bool y 2509 depends on X86_64 && TRANSPARENT_HUGEPAGE 2510 2511menu "Power management and ACPI options" 2512 2513config ARCH_HIBERNATION_HEADER 2514 def_bool y 2515 depends on HIBERNATION 2516 2517source "kernel/power/Kconfig" 2518 2519source "drivers/acpi/Kconfig" 2520 2521source "drivers/sfi/Kconfig" 2522 2523config X86_APM_BOOT 2524 def_bool y 2525 depends on APM 2526 2527menuconfig APM 2528 tristate "APM (Advanced Power Management) BIOS support" 2529 depends on X86_32 && PM_SLEEP 2530 ---help--- 2531 APM is a BIOS specification for saving power using several different 2532 techniques. This is mostly useful for battery powered laptops with 2533 APM compliant BIOSes. If you say Y here, the system time will be 2534 reset after a RESUME operation, the /proc/apm device will provide 2535 battery status information, and user-space programs will receive 2536 notification of APM "events" (e.g. battery status change). 2537 2538 If you select "Y" here, you can disable actual use of the APM 2539 BIOS by passing the "apm=off" option to the kernel at boot time. 2540 2541 Note that the APM support is almost completely disabled for 2542 machines with more than one CPU. 2543 2544 In order to use APM, you will need supporting software. For location 2545 and more information, read <file:Documentation/power/apm-acpi.rst> 2546 and the Battery Powered Linux mini-HOWTO, available from 2547 <http://www.tldp.org/docs.html#howto>. 2548 2549 This driver does not spin down disk drives (see the hdparm(8) 2550 manpage ("man 8 hdparm") for that), and it doesn't turn off 2551 VESA-compliant "green" monitors. 2552 2553 This driver does not support the TI 4000M TravelMate and the ACER 2554 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2555 desktop machines also don't have compliant BIOSes, and this driver 2556 may cause those machines to panic during the boot phase. 2557 2558 Generally, if you don't have a battery in your machine, there isn't 2559 much point in using this driver and you should say N. If you get 2560 random kernel OOPSes or reboots that don't seem to be related to 2561 anything, try disabling/enabling this option (or disabling/enabling 2562 APM in your BIOS). 2563 2564 Some other things you should try when experiencing seemingly random, 2565 "weird" problems: 2566 2567 1) make sure that you have enough swap space and that it is 2568 enabled. 2569 2) pass the "no-hlt" option to the kernel 2570 3) switch on floating point emulation in the kernel and pass 2571 the "no387" option to the kernel 2572 4) pass the "floppy=nodma" option to the kernel 2573 5) pass the "mem=4M" option to the kernel (thereby disabling 2574 all but the first 4 MB of RAM) 2575 6) make sure that the CPU is not over clocked. 2576 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2577 8) disable the cache from your BIOS settings 2578 9) install a fan for the video card or exchange video RAM 2579 10) install a better fan for the CPU 2580 11) exchange RAM chips 2581 12) exchange the motherboard. 2582 2583 To compile this driver as a module, choose M here: the 2584 module will be called apm. 2585 2586if APM 2587 2588config APM_IGNORE_USER_SUSPEND 2589 bool "Ignore USER SUSPEND" 2590 ---help--- 2591 This option will ignore USER SUSPEND requests. On machines with a 2592 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2593 series notebooks, it is necessary to say Y because of a BIOS bug. 2594 2595config APM_DO_ENABLE 2596 bool "Enable PM at boot time" 2597 ---help--- 2598 Enable APM features at boot time. From page 36 of the APM BIOS 2599 specification: "When disabled, the APM BIOS does not automatically 2600 power manage devices, enter the Standby State, enter the Suspend 2601 State, or take power saving steps in response to CPU Idle calls." 2602 This driver will make CPU Idle calls when Linux is idle (unless this 2603 feature is turned off -- see "Do CPU IDLE calls", below). This 2604 should always save battery power, but more complicated APM features 2605 will be dependent on your BIOS implementation. You may need to turn 2606 this option off if your computer hangs at boot time when using APM 2607 support, or if it beeps continuously instead of suspending. Turn 2608 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2609 T400CDT. This is off by default since most machines do fine without 2610 this feature. 2611 2612config APM_CPU_IDLE 2613 depends on CPU_IDLE 2614 bool "Make CPU Idle calls when idle" 2615 ---help--- 2616 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2617 On some machines, this can activate improved power savings, such as 2618 a slowed CPU clock rate, when the machine is idle. These idle calls 2619 are made after the idle loop has run for some length of time (e.g., 2620 333 mS). On some machines, this will cause a hang at boot time or 2621 whenever the CPU becomes idle. (On machines with more than one CPU, 2622 this option does nothing.) 2623 2624config APM_DISPLAY_BLANK 2625 bool "Enable console blanking using APM" 2626 ---help--- 2627 Enable console blanking using the APM. Some laptops can use this to 2628 turn off the LCD backlight when the screen blanker of the Linux 2629 virtual console blanks the screen. Note that this is only used by 2630 the virtual console screen blanker, and won't turn off the backlight 2631 when using the X Window system. This also doesn't have anything to 2632 do with your VESA-compliant power-saving monitor. Further, this 2633 option doesn't work for all laptops -- it might not turn off your 2634 backlight at all, or it might print a lot of errors to the console, 2635 especially if you are using gpm. 2636 2637config APM_ALLOW_INTS 2638 bool "Allow interrupts during APM BIOS calls" 2639 ---help--- 2640 Normally we disable external interrupts while we are making calls to 2641 the APM BIOS as a measure to lessen the effects of a badly behaving 2642 BIOS implementation. The BIOS should reenable interrupts if it 2643 needs to. Unfortunately, some BIOSes do not -- especially those in 2644 many of the newer IBM Thinkpads. If you experience hangs when you 2645 suspend, try setting this to Y. Otherwise, say N. 2646 2647endif # APM 2648 2649source "drivers/cpufreq/Kconfig" 2650 2651source "drivers/cpuidle/Kconfig" 2652 2653source "drivers/idle/Kconfig" 2654 2655endmenu 2656 2657 2658menu "Bus options (PCI etc.)" 2659 2660choice 2661 prompt "PCI access mode" 2662 depends on X86_32 && PCI 2663 default PCI_GOANY 2664 ---help--- 2665 On PCI systems, the BIOS can be used to detect the PCI devices and 2666 determine their configuration. However, some old PCI motherboards 2667 have BIOS bugs and may crash if this is done. Also, some embedded 2668 PCI-based systems don't have any BIOS at all. Linux can also try to 2669 detect the PCI hardware directly without using the BIOS. 2670 2671 With this option, you can specify how Linux should detect the 2672 PCI devices. If you choose "BIOS", the BIOS will be used, 2673 if you choose "Direct", the BIOS won't be used, and if you 2674 choose "MMConfig", then PCI Express MMCONFIG will be used. 2675 If you choose "Any", the kernel will try MMCONFIG, then the 2676 direct access method and falls back to the BIOS if that doesn't 2677 work. If unsure, go with the default, which is "Any". 2678 2679config PCI_GOBIOS 2680 bool "BIOS" 2681 2682config PCI_GOMMCONFIG 2683 bool "MMConfig" 2684 2685config PCI_GODIRECT 2686 bool "Direct" 2687 2688config PCI_GOOLPC 2689 bool "OLPC XO-1" 2690 depends on OLPC 2691 2692config PCI_GOANY 2693 bool "Any" 2694 2695endchoice 2696 2697config PCI_BIOS 2698 def_bool y 2699 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2700 2701# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2702config PCI_DIRECT 2703 def_bool y 2704 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2705 2706config PCI_MMCONFIG 2707 bool "Support mmconfig PCI config space access" if X86_64 2708 default y 2709 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2710 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2711 2712config PCI_OLPC 2713 def_bool y 2714 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2715 2716config PCI_XEN 2717 def_bool y 2718 depends on PCI && XEN 2719 select SWIOTLB_XEN 2720 2721config MMCONF_FAM10H 2722 def_bool y 2723 depends on X86_64 && PCI_MMCONFIG && ACPI 2724 2725config PCI_CNB20LE_QUIRK 2726 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2727 depends on PCI 2728 help 2729 Read the PCI windows out of the CNB20LE host bridge. This allows 2730 PCI hotplug to work on systems with the CNB20LE chipset which do 2731 not have ACPI. 2732 2733 There's no public spec for this chipset, and this functionality 2734 is known to be incomplete. 2735 2736 You should say N unless you know you need this. 2737 2738config ISA_BUS 2739 bool "ISA bus support on modern systems" if EXPERT 2740 help 2741 Expose ISA bus device drivers and options available for selection and 2742 configuration. Enable this option if your target machine has an ISA 2743 bus. ISA is an older system, displaced by PCI and newer bus 2744 architectures -- if your target machine is modern, it probably does 2745 not have an ISA bus. 2746 2747 If unsure, say N. 2748 2749# x86_64 have no ISA slots, but can have ISA-style DMA. 2750config ISA_DMA_API 2751 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2752 default y 2753 help 2754 Enables ISA-style DMA support for devices requiring such controllers. 2755 If unsure, say Y. 2756 2757if X86_32 2758 2759config ISA 2760 bool "ISA support" 2761 ---help--- 2762 Find out whether you have ISA slots on your motherboard. ISA is the 2763 name of a bus system, i.e. the way the CPU talks to the other stuff 2764 inside your box. Other bus systems are PCI, EISA, MicroChannel 2765 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2766 newer boards don't support it. If you have ISA, say Y, otherwise N. 2767 2768config SCx200 2769 tristate "NatSemi SCx200 support" 2770 ---help--- 2771 This provides basic support for National Semiconductor's 2772 (now AMD's) Geode processors. The driver probes for the 2773 PCI-IDs of several on-chip devices, so its a good dependency 2774 for other scx200_* drivers. 2775 2776 If compiled as a module, the driver is named scx200. 2777 2778config SCx200HR_TIMER 2779 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2780 depends on SCx200 2781 default y 2782 ---help--- 2783 This driver provides a clocksource built upon the on-chip 2784 27MHz high-resolution timer. Its also a workaround for 2785 NSC Geode SC-1100's buggy TSC, which loses time when the 2786 processor goes idle (as is done by the scheduler). The 2787 other workaround is idle=poll boot option. 2788 2789config OLPC 2790 bool "One Laptop Per Child support" 2791 depends on !X86_PAE 2792 select GPIOLIB 2793 select OF 2794 select OF_PROMTREE 2795 select IRQ_DOMAIN 2796 select OLPC_EC 2797 ---help--- 2798 Add support for detecting the unique features of the OLPC 2799 XO hardware. 2800 2801config OLPC_XO1_PM 2802 bool "OLPC XO-1 Power Management" 2803 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2804 ---help--- 2805 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2806 2807config OLPC_XO1_RTC 2808 bool "OLPC XO-1 Real Time Clock" 2809 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2810 ---help--- 2811 Add support for the XO-1 real time clock, which can be used as a 2812 programmable wakeup source. 2813 2814config OLPC_XO1_SCI 2815 bool "OLPC XO-1 SCI extras" 2816 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2817 depends on INPUT=y 2818 select POWER_SUPPLY 2819 ---help--- 2820 Add support for SCI-based features of the OLPC XO-1 laptop: 2821 - EC-driven system wakeups 2822 - Power button 2823 - Ebook switch 2824 - Lid switch 2825 - AC adapter status updates 2826 - Battery status updates 2827 2828config OLPC_XO15_SCI 2829 bool "OLPC XO-1.5 SCI extras" 2830 depends on OLPC && ACPI 2831 select POWER_SUPPLY 2832 ---help--- 2833 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2834 - EC-driven system wakeups 2835 - AC adapter status updates 2836 - Battery status updates 2837 2838config ALIX 2839 bool "PCEngines ALIX System Support (LED setup)" 2840 select GPIOLIB 2841 ---help--- 2842 This option enables system support for the PCEngines ALIX. 2843 At present this just sets up LEDs for GPIO control on 2844 ALIX2/3/6 boards. However, other system specific setup should 2845 get added here. 2846 2847 Note: You must still enable the drivers for GPIO and LED support 2848 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2849 2850 Note: You have to set alix.force=1 for boards with Award BIOS. 2851 2852config NET5501 2853 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2854 select GPIOLIB 2855 ---help--- 2856 This option enables system support for the Soekris Engineering net5501. 2857 2858config GEOS 2859 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2860 select GPIOLIB 2861 depends on DMI 2862 ---help--- 2863 This option enables system support for the Traverse Technologies GEOS. 2864 2865config TS5500 2866 bool "Technologic Systems TS-5500 platform support" 2867 depends on MELAN 2868 select CHECK_SIGNATURE 2869 select NEW_LEDS 2870 select LEDS_CLASS 2871 ---help--- 2872 This option enables system support for the Technologic Systems TS-5500. 2873 2874endif # X86_32 2875 2876config AMD_NB 2877 def_bool y 2878 depends on CPU_SUP_AMD && PCI 2879 2880config X86_SYSFB 2881 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2882 help 2883 Firmwares often provide initial graphics framebuffers so the BIOS, 2884 bootloader or kernel can show basic video-output during boot for 2885 user-guidance and debugging. Historically, x86 used the VESA BIOS 2886 Extensions and EFI-framebuffers for this, which are mostly limited 2887 to x86. 2888 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2889 framebuffers so the new generic system-framebuffer drivers can be 2890 used on x86. If the framebuffer is not compatible with the generic 2891 modes, it is advertised as fallback platform framebuffer so legacy 2892 drivers like efifb, vesafb and uvesafb can pick it up. 2893 If this option is not selected, all system framebuffers are always 2894 marked as fallback platform framebuffers as usual. 2895 2896 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2897 not be able to pick up generic system framebuffers if this option 2898 is selected. You are highly encouraged to enable simplefb as 2899 replacement if you select this option. simplefb can correctly deal 2900 with generic system framebuffers. But you should still keep vesafb 2901 and others enabled as fallback if a system framebuffer is 2902 incompatible with simplefb. 2903 2904 If unsure, say Y. 2905 2906endmenu 2907 2908 2909menu "Binary Emulations" 2910 2911config IA32_EMULATION 2912 bool "IA32 Emulation" 2913 depends on X86_64 2914 select ARCH_WANT_OLD_COMPAT_IPC 2915 select BINFMT_ELF 2916 select COMPAT_BINFMT_ELF 2917 select COMPAT_OLD_SIGACTION 2918 ---help--- 2919 Include code to run legacy 32-bit programs under a 2920 64-bit kernel. You should likely turn this on, unless you're 2921 100% sure that you don't have any 32-bit programs left. 2922 2923config IA32_AOUT 2924 tristate "IA32 a.out support" 2925 depends on IA32_EMULATION 2926 depends on BROKEN 2927 ---help--- 2928 Support old a.out binaries in the 32bit emulation. 2929 2930config X86_X32 2931 bool "x32 ABI for 64-bit mode" 2932 depends on X86_64 2933 ---help--- 2934 Include code to run binaries for the x32 native 32-bit ABI 2935 for 64-bit processors. An x32 process gets access to the 2936 full 64-bit register file and wide data path while leaving 2937 pointers at 32 bits for smaller memory footprint. 2938 2939 You will need a recent binutils (2.22 or later) with 2940 elf32_x86_64 support enabled to compile a kernel with this 2941 option set. 2942 2943config COMPAT_32 2944 def_bool y 2945 depends on IA32_EMULATION || X86_32 2946 select HAVE_UID16 2947 select OLD_SIGSUSPEND3 2948 2949config COMPAT 2950 def_bool y 2951 depends on IA32_EMULATION || X86_X32 2952 2953if COMPAT 2954config COMPAT_FOR_U64_ALIGNMENT 2955 def_bool y 2956 2957config SYSVIPC_COMPAT 2958 def_bool y 2959 depends on SYSVIPC 2960endif 2961 2962endmenu 2963 2964 2965config HAVE_ATOMIC_IOMAP 2966 def_bool y 2967 depends on X86_32 2968 2969config X86_DEV_DMA_OPS 2970 bool 2971 2972source "drivers/firmware/Kconfig" 2973 2974source "arch/x86/kvm/Kconfig" 2975
