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 GENERIC_VDSO_32 18 select HAVE_DEBUG_STACKOVERFLOW 19 select KMAP_LOCAL 20 select MODULES_USE_ELF_REL 21 select OLD_SIGACTION 22 23config X86_64 24 def_bool y 25 depends on 64BIT 26 # Options that are inherently 64-bit kernel only: 27 select ARCH_HAS_GIGANTIC_PAGE 28 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 29 select ARCH_USE_CMPXCHG_LOCKREF 30 select HAVE_ARCH_SOFT_DIRTY 31 select MODULES_USE_ELF_RELA 32 select NEED_DMA_MAP_STATE 33 select SWIOTLB 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_INIT 61 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 62 select ARCH_HAS_DEBUG_VIRTUAL 63 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 64 select ARCH_HAS_DEVMEM_IS_ALLOWED 65 select ARCH_HAS_EARLY_DEBUG if KGDB 66 select ARCH_HAS_ELF_RANDOMIZE 67 select ARCH_HAS_FAST_MULTIPLIER 68 select ARCH_HAS_FILTER_PGPROT 69 select ARCH_HAS_FORTIFY_SOURCE 70 select ARCH_HAS_GCOV_PROFILE_ALL 71 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 72 select ARCH_HAS_MEM_ENCRYPT 73 select ARCH_HAS_MEMBARRIER_SYNC_CORE 74 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 75 select ARCH_HAS_PMEM_API if X86_64 76 select ARCH_HAS_PTE_DEVMAP if X86_64 77 select ARCH_HAS_PTE_SPECIAL 78 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 79 select ARCH_HAS_COPY_MC if X86_64 80 select ARCH_HAS_SET_MEMORY 81 select ARCH_HAS_SET_DIRECT_MAP 82 select ARCH_HAS_STRICT_KERNEL_RWX 83 select ARCH_HAS_STRICT_MODULE_RWX 84 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 85 select ARCH_HAS_SYSCALL_WRAPPER 86 select ARCH_HAS_UBSAN_SANITIZE_ALL 87 select ARCH_HAS_DEBUG_WX 88 select ARCH_HAVE_NMI_SAFE_CMPXCHG 89 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 90 select ARCH_MIGHT_HAVE_PC_PARPORT 91 select ARCH_MIGHT_HAVE_PC_SERIO 92 select ARCH_STACKWALK 93 select ARCH_SUPPORTS_ACPI 94 select ARCH_SUPPORTS_ATOMIC_RMW 95 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 96 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 97 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 98 select ARCH_USE_BUILTIN_BSWAP 99 select ARCH_USE_QUEUED_RWLOCKS 100 select ARCH_USE_QUEUED_SPINLOCKS 101 select ARCH_USE_SYM_ANNOTATIONS 102 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 103 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 104 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 105 select ARCH_WANT_HUGE_PMD_SHARE 106 select ARCH_WANT_LD_ORPHAN_WARN 107 select ARCH_WANTS_THP_SWAP if X86_64 108 select BUILDTIME_TABLE_SORT 109 select CLKEVT_I8253 110 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 111 select CLOCKSOURCE_WATCHDOG 112 select DCACHE_WORD_ACCESS 113 select EDAC_ATOMIC_SCRUB 114 select EDAC_SUPPORT 115 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 116 select GENERIC_CLOCKEVENTS_MIN_ADJUST 117 select GENERIC_CMOS_UPDATE 118 select GENERIC_CPU_AUTOPROBE 119 select GENERIC_CPU_VULNERABILITIES 120 select GENERIC_EARLY_IOREMAP 121 select GENERIC_ENTRY 122 select GENERIC_FIND_FIRST_BIT 123 select GENERIC_IOMAP 124 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 125 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 126 select GENERIC_IRQ_MIGRATION if SMP 127 select GENERIC_IRQ_PROBE 128 select GENERIC_IRQ_RESERVATION_MODE 129 select GENERIC_IRQ_SHOW 130 select GENERIC_PENDING_IRQ if SMP 131 select GENERIC_PTDUMP 132 select GENERIC_SMP_IDLE_THREAD 133 select GENERIC_STRNCPY_FROM_USER 134 select GENERIC_STRNLEN_USER 135 select GENERIC_TIME_VSYSCALL 136 select GENERIC_GETTIMEOFDAY 137 select GENERIC_VDSO_TIME_NS 138 select GUP_GET_PTE_LOW_HIGH if X86_PAE 139 select HARDIRQS_SW_RESEND 140 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 141 select HAVE_ACPI_APEI if ACPI 142 select HAVE_ACPI_APEI_NMI if ACPI 143 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 144 select HAVE_ARCH_AUDITSYSCALL 145 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 146 select HAVE_ARCH_JUMP_LABEL 147 select HAVE_ARCH_JUMP_LABEL_RELATIVE 148 select HAVE_ARCH_KASAN if X86_64 149 select HAVE_ARCH_KASAN_VMALLOC if X86_64 150 select HAVE_ARCH_KGDB 151 select HAVE_ARCH_MMAP_RND_BITS if MMU 152 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 153 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 154 select HAVE_ARCH_PREL32_RELOCATIONS 155 select HAVE_ARCH_SECCOMP_FILTER 156 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 157 select HAVE_ARCH_STACKLEAK 158 select HAVE_ARCH_TRACEHOOK 159 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 160 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 161 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 162 select HAVE_ARCH_VMAP_STACK if X86_64 163 select HAVE_ARCH_WITHIN_STACK_FRAMES 164 select HAVE_ASM_MODVERSIONS 165 select HAVE_CMPXCHG_DOUBLE 166 select HAVE_CMPXCHG_LOCAL 167 select HAVE_CONTEXT_TRACKING if X86_64 168 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 169 select HAVE_C_RECORDMCOUNT 170 select HAVE_DEBUG_KMEMLEAK 171 select HAVE_DMA_CONTIGUOUS 172 select HAVE_DYNAMIC_FTRACE 173 select HAVE_DYNAMIC_FTRACE_WITH_REGS 174 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 175 select HAVE_EBPF_JIT 176 select HAVE_EFFICIENT_UNALIGNED_ACCESS 177 select HAVE_EISA 178 select HAVE_EXIT_THREAD 179 select HAVE_FAST_GUP 180 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 181 select HAVE_FTRACE_MCOUNT_RECORD 182 select HAVE_FUNCTION_GRAPH_TRACER 183 select HAVE_FUNCTION_TRACER 184 select HAVE_GCC_PLUGINS 185 select HAVE_HW_BREAKPOINT 186 select HAVE_IDE 187 select HAVE_IOREMAP_PROT 188 select HAVE_IRQ_TIME_ACCOUNTING 189 select HAVE_KERNEL_BZIP2 190 select HAVE_KERNEL_GZIP 191 select HAVE_KERNEL_LZ4 192 select HAVE_KERNEL_LZMA 193 select HAVE_KERNEL_LZO 194 select HAVE_KERNEL_XZ 195 select HAVE_KERNEL_ZSTD 196 select HAVE_KPROBES 197 select HAVE_KPROBES_ON_FTRACE 198 select HAVE_FUNCTION_ERROR_INJECTION 199 select HAVE_KRETPROBES 200 select HAVE_KVM 201 select HAVE_LIVEPATCH if X86_64 202 select HAVE_MIXED_BREAKPOINTS_REGS 203 select HAVE_MOD_ARCH_SPECIFIC 204 select HAVE_MOVE_PMD 205 select HAVE_MOVE_PUD 206 select HAVE_NMI 207 select HAVE_OPROFILE 208 select HAVE_OPTPROBES 209 select HAVE_PCSPKR_PLATFORM 210 select HAVE_PERF_EVENTS 211 select HAVE_PERF_EVENTS_NMI 212 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 213 select HAVE_PCI 214 select HAVE_PERF_REGS 215 select HAVE_PERF_USER_STACK_DUMP 216 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 217 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 218 select HAVE_REGS_AND_STACK_ACCESS_API 219 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 220 select HAVE_FUNCTION_ARG_ACCESS_API 221 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 222 select HAVE_STACK_VALIDATION if X86_64 223 select HAVE_STATIC_CALL 224 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 225 select HAVE_RSEQ 226 select HAVE_SYSCALL_TRACEPOINTS 227 select HAVE_UNSTABLE_SCHED_CLOCK 228 select HAVE_USER_RETURN_NOTIFIER 229 select HAVE_GENERIC_VDSO 230 select HOTPLUG_SMT if SMP 231 select IRQ_FORCED_THREADING 232 select NEED_SG_DMA_LENGTH 233 select PCI_DOMAINS if PCI 234 select PCI_LOCKLESS_CONFIG if PCI 235 select PERF_EVENTS 236 select RTC_LIB 237 select RTC_MC146818_LIB 238 select SPARSE_IRQ 239 select SRCU 240 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 241 select SYSCTL_EXCEPTION_TRACE 242 select THREAD_INFO_IN_TASK 243 select USER_STACKTRACE_SUPPORT 244 select VIRT_TO_BUS 245 select HAVE_ARCH_KCSAN if X86_64 246 select X86_FEATURE_NAMES if PROC_FS 247 select PROC_PID_ARCH_STATUS if PROC_FS 248 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 249 250config INSTRUCTION_DECODER 251 def_bool y 252 depends on KPROBES || PERF_EVENTS || UPROBES 253 254config OUTPUT_FORMAT 255 string 256 default "elf32-i386" if X86_32 257 default "elf64-x86-64" if X86_64 258 259config LOCKDEP_SUPPORT 260 def_bool y 261 262config STACKTRACE_SUPPORT 263 def_bool y 264 265config MMU 266 def_bool y 267 268config ARCH_MMAP_RND_BITS_MIN 269 default 28 if 64BIT 270 default 8 271 272config ARCH_MMAP_RND_BITS_MAX 273 default 32 if 64BIT 274 default 16 275 276config ARCH_MMAP_RND_COMPAT_BITS_MIN 277 default 8 278 279config ARCH_MMAP_RND_COMPAT_BITS_MAX 280 default 16 281 282config SBUS 283 bool 284 285config GENERIC_ISA_DMA 286 def_bool y 287 depends on ISA_DMA_API 288 289config GENERIC_BUG 290 def_bool y 291 depends on BUG 292 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 293 294config GENERIC_BUG_RELATIVE_POINTERS 295 bool 296 297config ARCH_MAY_HAVE_PC_FDC 298 def_bool y 299 depends on ISA_DMA_API 300 301config GENERIC_CALIBRATE_DELAY 302 def_bool y 303 304config ARCH_HAS_CPU_RELAX 305 def_bool y 306 307config ARCH_HAS_CACHE_LINE_SIZE 308 def_bool y 309 310config ARCH_HAS_FILTER_PGPROT 311 def_bool y 312 313config HAVE_SETUP_PER_CPU_AREA 314 def_bool y 315 316config NEED_PER_CPU_EMBED_FIRST_CHUNK 317 def_bool y 318 319config NEED_PER_CPU_PAGE_FIRST_CHUNK 320 def_bool y 321 322config ARCH_HIBERNATION_POSSIBLE 323 def_bool y 324 325config ARCH_SUSPEND_POSSIBLE 326 def_bool y 327 328config ARCH_WANT_GENERAL_HUGETLB 329 def_bool y 330 331config ZONE_DMA32 332 def_bool y if X86_64 333 334config AUDIT_ARCH 335 def_bool y if X86_64 336 337config KASAN_SHADOW_OFFSET 338 hex 339 depends on KASAN 340 default 0xdffffc0000000000 341 342config HAVE_INTEL_TXT 343 def_bool y 344 depends on INTEL_IOMMU && ACPI 345 346config X86_32_SMP 347 def_bool y 348 depends on X86_32 && SMP 349 350config X86_64_SMP 351 def_bool y 352 depends on X86_64 && SMP 353 354config X86_32_LAZY_GS 355 def_bool y 356 depends on X86_32 && !STACKPROTECTOR 357 358config ARCH_SUPPORTS_UPROBES 359 def_bool y 360 361config FIX_EARLYCON_MEM 362 def_bool y 363 364config DYNAMIC_PHYSICAL_MASK 365 bool 366 367config PGTABLE_LEVELS 368 int 369 default 5 if X86_5LEVEL 370 default 4 if X86_64 371 default 3 if X86_PAE 372 default 2 373 374config CC_HAS_SANE_STACKPROTECTOR 375 bool 376 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 377 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 378 help 379 We have to make sure stack protector is unconditionally disabled if 380 the compiler produces broken code. 381 382menu "Processor type and features" 383 384config ZONE_DMA 385 bool "DMA memory allocation support" if EXPERT 386 default y 387 help 388 DMA memory allocation support allows devices with less than 32-bit 389 addressing to allocate within the first 16MB of address space. 390 Disable if no such devices will be used. 391 392 If unsure, say Y. 393 394config SMP 395 bool "Symmetric multi-processing support" 396 help 397 This enables support for systems with more than one CPU. If you have 398 a system with only one CPU, say N. If you have a system with more 399 than one CPU, say Y. 400 401 If you say N here, the kernel will run on uni- and multiprocessor 402 machines, but will use only one CPU of a multiprocessor machine. If 403 you say Y here, the kernel will run on many, but not all, 404 uniprocessor machines. On a uniprocessor machine, the kernel 405 will run faster if you say N here. 406 407 Note that if you say Y here and choose architecture "586" or 408 "Pentium" under "Processor family", the kernel will not work on 486 409 architectures. Similarly, multiprocessor kernels for the "PPro" 410 architecture may not work on all Pentium based boards. 411 412 People using multiprocessor machines who say Y here should also say 413 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 414 Management" code will be disabled if you say Y here. 415 416 See also <file:Documentation/x86/i386/IO-APIC.rst>, 417 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 418 <http://www.tldp.org/docs.html#howto>. 419 420 If you don't know what to do here, say N. 421 422config X86_FEATURE_NAMES 423 bool "Processor feature human-readable names" if EMBEDDED 424 default y 425 help 426 This option compiles in a table of x86 feature bits and corresponding 427 names. This is required to support /proc/cpuinfo and a few kernel 428 messages. You can disable this to save space, at the expense of 429 making those few kernel messages show numeric feature bits instead. 430 431 If in doubt, say Y. 432 433config X86_X2APIC 434 bool "Support x2apic" 435 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 436 help 437 This enables x2apic support on CPUs that have this feature. 438 439 This allows 32-bit apic IDs (so it can support very large systems), 440 and accesses the local apic via MSRs not via mmio. 441 442 If you don't know what to do here, say N. 443 444config X86_MPPARSE 445 bool "Enable MPS table" if ACPI || SFI 446 default y 447 depends on X86_LOCAL_APIC 448 help 449 For old smp systems that do not have proper acpi support. Newer systems 450 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 451 452config GOLDFISH 453 def_bool y 454 depends on X86_GOLDFISH 455 456config RETPOLINE 457 bool "Avoid speculative indirect branches in kernel" 458 default y 459 help 460 Compile kernel with the retpoline compiler options to guard against 461 kernel-to-user data leaks by avoiding speculative indirect 462 branches. Requires a compiler with -mindirect-branch=thunk-extern 463 support for full protection. The kernel may run slower. 464 465config X86_CPU_RESCTRL 466 bool "x86 CPU resource control support" 467 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 468 select KERNFS 469 select PROC_CPU_RESCTRL if PROC_FS 470 help 471 Enable x86 CPU resource control support. 472 473 Provide support for the allocation and monitoring of system resources 474 usage by the CPU. 475 476 Intel calls this Intel Resource Director Technology 477 (Intel(R) RDT). More information about RDT can be found in the 478 Intel x86 Architecture Software Developer Manual. 479 480 AMD calls this AMD Platform Quality of Service (AMD QoS). 481 More information about AMD QoS can be found in the AMD64 Technology 482 Platform Quality of Service Extensions manual. 483 484 Say N if unsure. 485 486if X86_32 487config X86_BIGSMP 488 bool "Support for big SMP systems with more than 8 CPUs" 489 depends on SMP 490 help 491 This option is needed for the systems that have more than 8 CPUs. 492 493config X86_EXTENDED_PLATFORM 494 bool "Support for extended (non-PC) x86 platforms" 495 default y 496 help 497 If you disable this option then the kernel will only support 498 standard PC platforms. (which covers the vast majority of 499 systems out there.) 500 501 If you enable this option then you'll be able to select support 502 for the following (non-PC) 32 bit x86 platforms: 503 Goldfish (Android emulator) 504 AMD Elan 505 RDC R-321x SoC 506 SGI 320/540 (Visual Workstation) 507 STA2X11-based (e.g. Northville) 508 Moorestown MID devices 509 510 If you have one of these systems, or if you want to build a 511 generic distribution kernel, say Y here - otherwise say N. 512endif 513 514if X86_64 515config X86_EXTENDED_PLATFORM 516 bool "Support for extended (non-PC) x86 platforms" 517 default y 518 help 519 If you disable this option then the kernel will only support 520 standard PC platforms. (which covers the vast majority of 521 systems out there.) 522 523 If you enable this option then you'll be able to select support 524 for the following (non-PC) 64 bit x86 platforms: 525 Numascale NumaChip 526 ScaleMP vSMP 527 SGI Ultraviolet 528 529 If you have one of these systems, or if you want to build a 530 generic distribution kernel, say Y here - otherwise say N. 531endif 532# This is an alphabetically sorted list of 64 bit extended platforms 533# Please maintain the alphabetic order if and when there are additions 534config X86_NUMACHIP 535 bool "Numascale NumaChip" 536 depends on X86_64 537 depends on X86_EXTENDED_PLATFORM 538 depends on NUMA 539 depends on SMP 540 depends on X86_X2APIC 541 depends on PCI_MMCONFIG 542 help 543 Adds support for Numascale NumaChip large-SMP systems. Needed to 544 enable more than ~168 cores. 545 If you don't have one of these, you should say N here. 546 547config X86_VSMP 548 bool "ScaleMP vSMP" 549 select HYPERVISOR_GUEST 550 select PARAVIRT 551 depends on X86_64 && PCI 552 depends on X86_EXTENDED_PLATFORM 553 depends on SMP 554 help 555 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 556 supposed to run on these EM64T-based machines. Only choose this option 557 if you have one of these machines. 558 559config X86_UV 560 bool "SGI Ultraviolet" 561 depends on X86_64 562 depends on X86_EXTENDED_PLATFORM 563 depends on NUMA 564 depends on EFI 565 depends on X86_X2APIC 566 depends on PCI 567 help 568 This option is needed in order to support SGI Ultraviolet systems. 569 If you don't have one of these, you should say N here. 570 571# Following is an alphabetically sorted list of 32 bit extended platforms 572# Please maintain the alphabetic order if and when there are additions 573 574config X86_GOLDFISH 575 bool "Goldfish (Virtual Platform)" 576 depends on X86_EXTENDED_PLATFORM 577 help 578 Enable support for the Goldfish virtual platform used primarily 579 for Android development. Unless you are building for the Android 580 Goldfish emulator say N here. 581 582config X86_INTEL_CE 583 bool "CE4100 TV platform" 584 depends on PCI 585 depends on PCI_GODIRECT 586 depends on X86_IO_APIC 587 depends on X86_32 588 depends on X86_EXTENDED_PLATFORM 589 select X86_REBOOTFIXUPS 590 select OF 591 select OF_EARLY_FLATTREE 592 help 593 Select for the Intel CE media processor (CE4100) SOC. 594 This option compiles in support for the CE4100 SOC for settop 595 boxes and media devices. 596 597config X86_INTEL_MID 598 bool "Intel MID platform support" 599 depends on X86_EXTENDED_PLATFORM 600 depends on X86_PLATFORM_DEVICES 601 depends on PCI 602 depends on X86_64 || (PCI_GOANY && X86_32) 603 depends on X86_IO_APIC 604 select SFI 605 select I2C 606 select DW_APB_TIMER 607 select APB_TIMER 608 select INTEL_SCU_PCI 609 select MFD_INTEL_MSIC 610 help 611 Select to build a kernel capable of supporting Intel MID (Mobile 612 Internet Device) platform systems which do not have the PCI legacy 613 interfaces. If you are building for a PC class system say N here. 614 615 Intel MID platforms are based on an Intel processor and chipset which 616 consume less power than most of the x86 derivatives. 617 618config X86_INTEL_QUARK 619 bool "Intel Quark platform support" 620 depends on X86_32 621 depends on X86_EXTENDED_PLATFORM 622 depends on X86_PLATFORM_DEVICES 623 depends on X86_TSC 624 depends on PCI 625 depends on PCI_GOANY 626 depends on X86_IO_APIC 627 select IOSF_MBI 628 select INTEL_IMR 629 select COMMON_CLK 630 help 631 Select to include support for Quark X1000 SoC. 632 Say Y here if you have a Quark based system such as the Arduino 633 compatible Intel Galileo. 634 635config X86_INTEL_LPSS 636 bool "Intel Low Power Subsystem Support" 637 depends on X86 && ACPI && PCI 638 select COMMON_CLK 639 select PINCTRL 640 select IOSF_MBI 641 help 642 Select to build support for Intel Low Power Subsystem such as 643 found on Intel Lynxpoint PCH. Selecting this option enables 644 things like clock tree (common clock framework) and pincontrol 645 which are needed by the LPSS peripheral drivers. 646 647config X86_AMD_PLATFORM_DEVICE 648 bool "AMD ACPI2Platform devices support" 649 depends on ACPI 650 select COMMON_CLK 651 select PINCTRL 652 help 653 Select to interpret AMD specific ACPI device to platform device 654 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 655 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 656 implemented under PINCTRL subsystem. 657 658config IOSF_MBI 659 tristate "Intel SoC IOSF Sideband support for SoC platforms" 660 depends on PCI 661 help 662 This option enables sideband register access support for Intel SoC 663 platforms. On these platforms the IOSF sideband is used in lieu of 664 MSR's for some register accesses, mostly but not limited to thermal 665 and power. Drivers may query the availability of this device to 666 determine if they need the sideband in order to work on these 667 platforms. The sideband is available on the following SoC products. 668 This list is not meant to be exclusive. 669 - BayTrail 670 - Braswell 671 - Quark 672 673 You should say Y if you are running a kernel on one of these SoC's. 674 675config IOSF_MBI_DEBUG 676 bool "Enable IOSF sideband access through debugfs" 677 depends on IOSF_MBI && DEBUG_FS 678 help 679 Select this option to expose the IOSF sideband access registers (MCR, 680 MDR, MCRX) through debugfs to write and read register information from 681 different units on the SoC. This is most useful for obtaining device 682 state information for debug and analysis. As this is a general access 683 mechanism, users of this option would have specific knowledge of the 684 device they want to access. 685 686 If you don't require the option or are in doubt, say N. 687 688config X86_RDC321X 689 bool "RDC R-321x SoC" 690 depends on X86_32 691 depends on X86_EXTENDED_PLATFORM 692 select M486 693 select X86_REBOOTFIXUPS 694 help 695 This option is needed for RDC R-321x system-on-chip, also known 696 as R-8610-(G). 697 If you don't have one of these chips, you should say N here. 698 699config X86_32_NON_STANDARD 700 bool "Support non-standard 32-bit SMP architectures" 701 depends on X86_32 && SMP 702 depends on X86_EXTENDED_PLATFORM 703 help 704 This option compiles in the bigsmp and STA2X11 default 705 subarchitectures. It is intended for a generic binary 706 kernel. If you select them all, kernel will probe it one by 707 one and will fallback to default. 708 709# Alphabetically sorted list of Non standard 32 bit platforms 710 711config X86_SUPPORTS_MEMORY_FAILURE 712 def_bool y 713 # MCE code calls memory_failure(): 714 depends on X86_MCE 715 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 716 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 717 depends on X86_64 || !SPARSEMEM 718 select ARCH_SUPPORTS_MEMORY_FAILURE 719 720config STA2X11 721 bool "STA2X11 Companion Chip Support" 722 depends on X86_32_NON_STANDARD && PCI 723 select SWIOTLB 724 select MFD_STA2X11 725 select GPIOLIB 726 help 727 This adds support for boards based on the STA2X11 IO-Hub, 728 a.k.a. "ConneXt". The chip is used in place of the standard 729 PC chipset, so all "standard" peripherals are missing. If this 730 option is selected the kernel will still be able to boot on 731 standard PC machines. 732 733config X86_32_IRIS 734 tristate "Eurobraille/Iris poweroff module" 735 depends on X86_32 736 help 737 The Iris machines from EuroBraille do not have APM or ACPI support 738 to shut themselves down properly. A special I/O sequence is 739 needed to do so, which is what this module does at 740 kernel shutdown. 741 742 This is only for Iris machines from EuroBraille. 743 744 If unused, say N. 745 746config SCHED_OMIT_FRAME_POINTER 747 def_bool y 748 prompt "Single-depth WCHAN output" 749 depends on X86 750 help 751 Calculate simpler /proc/<PID>/wchan values. If this option 752 is disabled then wchan values will recurse back to the 753 caller function. This provides more accurate wchan values, 754 at the expense of slightly more scheduling overhead. 755 756 If in doubt, say "Y". 757 758menuconfig HYPERVISOR_GUEST 759 bool "Linux guest support" 760 help 761 Say Y here to enable options for running Linux under various hyper- 762 visors. This option enables basic hypervisor detection and platform 763 setup. 764 765 If you say N, all options in this submenu will be skipped and 766 disabled, and Linux guest support won't be built in. 767 768if HYPERVISOR_GUEST 769 770config PARAVIRT 771 bool "Enable paravirtualization code" 772 help 773 This changes the kernel so it can modify itself when it is run 774 under a hypervisor, potentially improving performance significantly 775 over full virtualization. However, when run without a hypervisor 776 the kernel is theoretically slower and slightly larger. 777 778config PARAVIRT_XXL 779 bool 780 781config PARAVIRT_DEBUG 782 bool "paravirt-ops debugging" 783 depends on PARAVIRT && DEBUG_KERNEL 784 help 785 Enable to debug paravirt_ops internals. Specifically, BUG if 786 a paravirt_op is missing when it is called. 787 788config PARAVIRT_SPINLOCKS 789 bool "Paravirtualization layer for spinlocks" 790 depends on PARAVIRT && SMP 791 help 792 Paravirtualized spinlocks allow a pvops backend to replace the 793 spinlock implementation with something virtualization-friendly 794 (for example, block the virtual CPU rather than spinning). 795 796 It has a minimal impact on native kernels and gives a nice performance 797 benefit on paravirtualized KVM / Xen kernels. 798 799 If you are unsure how to answer this question, answer Y. 800 801config X86_HV_CALLBACK_VECTOR 802 def_bool n 803 804source "arch/x86/xen/Kconfig" 805 806config KVM_GUEST 807 bool "KVM Guest support (including kvmclock)" 808 depends on PARAVIRT 809 select PARAVIRT_CLOCK 810 select ARCH_CPUIDLE_HALTPOLL 811 select X86_HV_CALLBACK_VECTOR 812 default y 813 help 814 This option enables various optimizations for running under the KVM 815 hypervisor. It includes a paravirtualized clock, so that instead 816 of relying on a PIT (or probably other) emulation by the 817 underlying device model, the host provides the guest with 818 timing infrastructure such as time of day, and system time 819 820config ARCH_CPUIDLE_HALTPOLL 821 def_bool n 822 prompt "Disable host haltpoll when loading haltpoll driver" 823 help 824 If virtualized under KVM, disable host haltpoll. 825 826config PVH 827 bool "Support for running PVH guests" 828 help 829 This option enables the PVH entry point for guest virtual machines 830 as specified in the x86/HVM direct boot ABI. 831 832config PARAVIRT_TIME_ACCOUNTING 833 bool "Paravirtual steal time accounting" 834 depends on PARAVIRT 835 help 836 Select this option to enable fine granularity task steal time 837 accounting. Time spent executing other tasks in parallel with 838 the current vCPU is discounted from the vCPU power. To account for 839 that, there can be a small performance impact. 840 841 If in doubt, say N here. 842 843config PARAVIRT_CLOCK 844 bool 845 846config JAILHOUSE_GUEST 847 bool "Jailhouse non-root cell support" 848 depends on X86_64 && PCI 849 select X86_PM_TIMER 850 help 851 This option allows to run Linux as guest in a Jailhouse non-root 852 cell. You can leave this option disabled if you only want to start 853 Jailhouse and run Linux afterwards in the root cell. 854 855config ACRN_GUEST 856 bool "ACRN Guest support" 857 depends on X86_64 858 select X86_HV_CALLBACK_VECTOR 859 help 860 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 861 a flexible, lightweight reference open-source hypervisor, built with 862 real-time and safety-criticality in mind. It is built for embedded 863 IOT with small footprint and real-time features. More details can be 864 found in https://projectacrn.org/. 865 866endif #HYPERVISOR_GUEST 867 868source "arch/x86/Kconfig.cpu" 869 870config HPET_TIMER 871 def_bool X86_64 872 prompt "HPET Timer Support" if X86_32 873 help 874 Use the IA-PC HPET (High Precision Event Timer) to manage 875 time in preference to the PIT and RTC, if a HPET is 876 present. 877 HPET is the next generation timer replacing legacy 8254s. 878 The HPET provides a stable time base on SMP 879 systems, unlike the TSC, but it is more expensive to access, 880 as it is off-chip. The interface used is documented 881 in the HPET spec, revision 1. 882 883 You can safely choose Y here. However, HPET will only be 884 activated if the platform and the BIOS support this feature. 885 Otherwise the 8254 will be used for timing services. 886 887 Choose N to continue using the legacy 8254 timer. 888 889config HPET_EMULATE_RTC 890 def_bool y 891 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 892 893config APB_TIMER 894 def_bool y if X86_INTEL_MID 895 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 896 select DW_APB_TIMER 897 depends on X86_INTEL_MID && SFI 898 help 899 APB timer is the replacement for 8254, HPET on X86 MID platforms. 900 The APBT provides a stable time base on SMP 901 systems, unlike the TSC, but it is more expensive to access, 902 as it is off-chip. APB timers are always running regardless of CPU 903 C states, they are used as per CPU clockevent device when possible. 904 905# Mark as expert because too many people got it wrong. 906# The code disables itself when not needed. 907config DMI 908 default y 909 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 910 bool "Enable DMI scanning" if EXPERT 911 help 912 Enabled scanning of DMI to identify machine quirks. Say Y 913 here unless you have verified that your setup is not 914 affected by entries in the DMI blacklist. Required by PNP 915 BIOS code. 916 917config GART_IOMMU 918 bool "Old AMD GART IOMMU support" 919 select DMA_OPS 920 select IOMMU_HELPER 921 select SWIOTLB 922 depends on X86_64 && PCI && AMD_NB 923 help 924 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 925 GART based hardware IOMMUs. 926 927 The GART supports full DMA access for devices with 32-bit access 928 limitations, on systems with more than 3 GB. This is usually needed 929 for USB, sound, many IDE/SATA chipsets and some other devices. 930 931 Newer systems typically have a modern AMD IOMMU, supported via 932 the CONFIG_AMD_IOMMU=y config option. 933 934 In normal configurations this driver is only active when needed: 935 there's more than 3 GB of memory and the system contains a 936 32-bit limited device. 937 938 If unsure, say Y. 939 940config MAXSMP 941 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 942 depends on X86_64 && SMP && DEBUG_KERNEL 943 select CPUMASK_OFFSTACK 944 help 945 Enable maximum number of CPUS and NUMA Nodes for this architecture. 946 If unsure, say N. 947 948# 949# The maximum number of CPUs supported: 950# 951# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 952# and which can be configured interactively in the 953# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 954# 955# The ranges are different on 32-bit and 64-bit kernels, depending on 956# hardware capabilities and scalability features of the kernel. 957# 958# ( If MAXSMP is enabled we just use the highest possible value and disable 959# interactive configuration. ) 960# 961 962config NR_CPUS_RANGE_BEGIN 963 int 964 default NR_CPUS_RANGE_END if MAXSMP 965 default 1 if !SMP 966 default 2 967 968config NR_CPUS_RANGE_END 969 int 970 depends on X86_32 971 default 64 if SMP && X86_BIGSMP 972 default 8 if SMP && !X86_BIGSMP 973 default 1 if !SMP 974 975config NR_CPUS_RANGE_END 976 int 977 depends on X86_64 978 default 8192 if SMP && CPUMASK_OFFSTACK 979 default 512 if SMP && !CPUMASK_OFFSTACK 980 default 1 if !SMP 981 982config NR_CPUS_DEFAULT 983 int 984 depends on X86_32 985 default 32 if X86_BIGSMP 986 default 8 if SMP 987 default 1 if !SMP 988 989config NR_CPUS_DEFAULT 990 int 991 depends on X86_64 992 default 8192 if MAXSMP 993 default 64 if SMP 994 default 1 if !SMP 995 996config NR_CPUS 997 int "Maximum number of CPUs" if SMP && !MAXSMP 998 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 999 default NR_CPUS_DEFAULT 1000 help 1001 This allows you to specify the maximum number of CPUs which this 1002 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1003 supported value is 8192, otherwise the maximum value is 512. The 1004 minimum value which makes sense is 2. 1005 1006 This is purely to save memory: each supported CPU adds about 8KB 1007 to the kernel image. 1008 1009config SCHED_SMT 1010 def_bool y if SMP 1011 1012config SCHED_MC 1013 def_bool y 1014 prompt "Multi-core scheduler support" 1015 depends on SMP 1016 help 1017 Multi-core scheduler support improves the CPU scheduler's decision 1018 making when dealing with multi-core CPU chips at a cost of slightly 1019 increased overhead in some places. If unsure say N here. 1020 1021config SCHED_MC_PRIO 1022 bool "CPU core priorities scheduler support" 1023 depends on SCHED_MC && CPU_SUP_INTEL 1024 select X86_INTEL_PSTATE 1025 select CPU_FREQ 1026 default y 1027 help 1028 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1029 core ordering determined at manufacturing time, which allows 1030 certain cores to reach higher turbo frequencies (when running 1031 single threaded workloads) than others. 1032 1033 Enabling this kernel feature teaches the scheduler about 1034 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1035 scheduler's CPU selection logic accordingly, so that higher 1036 overall system performance can be achieved. 1037 1038 This feature will have no effect on CPUs without this feature. 1039 1040 If unsure say Y here. 1041 1042config UP_LATE_INIT 1043 def_bool y 1044 depends on !SMP && X86_LOCAL_APIC 1045 1046config X86_UP_APIC 1047 bool "Local APIC support on uniprocessors" if !PCI_MSI 1048 default PCI_MSI 1049 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1050 help 1051 A local APIC (Advanced Programmable Interrupt Controller) is an 1052 integrated interrupt controller in the CPU. If you have a single-CPU 1053 system which has a processor with a local APIC, you can say Y here to 1054 enable and use it. If you say Y here even though your machine doesn't 1055 have a local APIC, then the kernel will still run with no slowdown at 1056 all. The local APIC supports CPU-generated self-interrupts (timer, 1057 performance counters), and the NMI watchdog which detects hard 1058 lockups. 1059 1060config X86_UP_IOAPIC 1061 bool "IO-APIC support on uniprocessors" 1062 depends on X86_UP_APIC 1063 help 1064 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1065 SMP-capable replacement for PC-style interrupt controllers. Most 1066 SMP systems and many recent uniprocessor systems have one. 1067 1068 If you have a single-CPU system with an IO-APIC, you can say Y here 1069 to use it. If you say Y here even though your machine doesn't have 1070 an IO-APIC, then the kernel will still run with no slowdown at all. 1071 1072config X86_LOCAL_APIC 1073 def_bool y 1074 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1075 select IRQ_DOMAIN_HIERARCHY 1076 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1077 1078config X86_IO_APIC 1079 def_bool y 1080 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1081 1082config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1083 bool "Reroute for broken boot IRQs" 1084 depends on X86_IO_APIC 1085 help 1086 This option enables a workaround that fixes a source of 1087 spurious interrupts. This is recommended when threaded 1088 interrupt handling is used on systems where the generation of 1089 superfluous "boot interrupts" cannot be disabled. 1090 1091 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1092 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1093 kernel does during interrupt handling). On chipsets where this 1094 boot IRQ generation cannot be disabled, this workaround keeps 1095 the original IRQ line masked so that only the equivalent "boot 1096 IRQ" is delivered to the CPUs. The workaround also tells the 1097 kernel to set up the IRQ handler on the boot IRQ line. In this 1098 way only one interrupt is delivered to the kernel. Otherwise 1099 the spurious second interrupt may cause the kernel to bring 1100 down (vital) interrupt lines. 1101 1102 Only affects "broken" chipsets. Interrupt sharing may be 1103 increased on these systems. 1104 1105config X86_MCE 1106 bool "Machine Check / overheating reporting" 1107 select GENERIC_ALLOCATOR 1108 default y 1109 help 1110 Machine Check support allows the processor to notify the 1111 kernel if it detects a problem (e.g. overheating, data corruption). 1112 The action the kernel takes depends on the severity of the problem, 1113 ranging from warning messages to halting the machine. 1114 1115config X86_MCELOG_LEGACY 1116 bool "Support for deprecated /dev/mcelog character device" 1117 depends on X86_MCE 1118 help 1119 Enable support for /dev/mcelog which is needed by the old mcelog 1120 userspace logging daemon. Consider switching to the new generation 1121 rasdaemon solution. 1122 1123config X86_MCE_INTEL 1124 def_bool y 1125 prompt "Intel MCE features" 1126 depends on X86_MCE && X86_LOCAL_APIC 1127 help 1128 Additional support for intel specific MCE features such as 1129 the thermal monitor. 1130 1131config X86_MCE_AMD 1132 def_bool y 1133 prompt "AMD MCE features" 1134 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1135 help 1136 Additional support for AMD specific MCE features such as 1137 the DRAM Error Threshold. 1138 1139config X86_ANCIENT_MCE 1140 bool "Support for old Pentium 5 / WinChip machine checks" 1141 depends on X86_32 && X86_MCE 1142 help 1143 Include support for machine check handling on old Pentium 5 or WinChip 1144 systems. These typically need to be enabled explicitly on the command 1145 line. 1146 1147config X86_MCE_THRESHOLD 1148 depends on X86_MCE_AMD || X86_MCE_INTEL 1149 def_bool y 1150 1151config X86_MCE_INJECT 1152 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1153 tristate "Machine check injector support" 1154 help 1155 Provide support for injecting machine checks for testing purposes. 1156 If you don't know what a machine check is and you don't do kernel 1157 QA it is safe to say n. 1158 1159config X86_THERMAL_VECTOR 1160 def_bool y 1161 depends on X86_MCE_INTEL 1162 1163source "arch/x86/events/Kconfig" 1164 1165config X86_LEGACY_VM86 1166 bool "Legacy VM86 support" 1167 depends on X86_32 1168 help 1169 This option allows user programs to put the CPU into V8086 1170 mode, which is an 80286-era approximation of 16-bit real mode. 1171 1172 Some very old versions of X and/or vbetool require this option 1173 for user mode setting. Similarly, DOSEMU will use it if 1174 available to accelerate real mode DOS programs. However, any 1175 recent version of DOSEMU, X, or vbetool should be fully 1176 functional even without kernel VM86 support, as they will all 1177 fall back to software emulation. Nevertheless, if you are using 1178 a 16-bit DOS program where 16-bit performance matters, vm86 1179 mode might be faster than emulation and you might want to 1180 enable this option. 1181 1182 Note that any app that works on a 64-bit kernel is unlikely to 1183 need this option, as 64-bit kernels don't, and can't, support 1184 V8086 mode. This option is also unrelated to 16-bit protected 1185 mode and is not needed to run most 16-bit programs under Wine. 1186 1187 Enabling this option increases the complexity of the kernel 1188 and slows down exception handling a tiny bit. 1189 1190 If unsure, say N here. 1191 1192config VM86 1193 bool 1194 default X86_LEGACY_VM86 1195 1196config X86_16BIT 1197 bool "Enable support for 16-bit segments" if EXPERT 1198 default y 1199 depends on MODIFY_LDT_SYSCALL 1200 help 1201 This option is required by programs like Wine to run 16-bit 1202 protected mode legacy code on x86 processors. Disabling 1203 this option saves about 300 bytes on i386, or around 6K text 1204 plus 16K runtime memory on x86-64, 1205 1206config X86_ESPFIX32 1207 def_bool y 1208 depends on X86_16BIT && X86_32 1209 1210config X86_ESPFIX64 1211 def_bool y 1212 depends on X86_16BIT && X86_64 1213 1214config X86_VSYSCALL_EMULATION 1215 bool "Enable vsyscall emulation" if EXPERT 1216 default y 1217 depends on X86_64 1218 help 1219 This enables emulation of the legacy vsyscall page. Disabling 1220 it is roughly equivalent to booting with vsyscall=none, except 1221 that it will also disable the helpful warning if a program 1222 tries to use a vsyscall. With this option set to N, offending 1223 programs will just segfault, citing addresses of the form 1224 0xffffffffff600?00. 1225 1226 This option is required by many programs built before 2013, and 1227 care should be used even with newer programs if set to N. 1228 1229 Disabling this option saves about 7K of kernel size and 1230 possibly 4K of additional runtime pagetable memory. 1231 1232config X86_IOPL_IOPERM 1233 bool "IOPERM and IOPL Emulation" 1234 default y 1235 help 1236 This enables the ioperm() and iopl() syscalls which are necessary 1237 for legacy applications. 1238 1239 Legacy IOPL support is an overbroad mechanism which allows user 1240 space aside of accessing all 65536 I/O ports also to disable 1241 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1242 capabilities and permission from potentially active security 1243 modules. 1244 1245 The emulation restricts the functionality of the syscall to 1246 only allowing the full range I/O port access, but prevents the 1247 ability to disable interrupts from user space which would be 1248 granted if the hardware IOPL mechanism would be used. 1249 1250config TOSHIBA 1251 tristate "Toshiba Laptop support" 1252 depends on X86_32 1253 help 1254 This adds a driver to safely access the System Management Mode of 1255 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1256 not work on models with a Phoenix BIOS. The System Management Mode 1257 is used to set the BIOS and power saving options on Toshiba portables. 1258 1259 For information on utilities to make use of this driver see the 1260 Toshiba Linux utilities web site at: 1261 <http://www.buzzard.org.uk/toshiba/>. 1262 1263 Say Y if you intend to run this kernel on a Toshiba portable. 1264 Say N otherwise. 1265 1266config I8K 1267 tristate "Dell i8k legacy laptop support" 1268 select HWMON 1269 select SENSORS_DELL_SMM 1270 help 1271 This option enables legacy /proc/i8k userspace interface in hwmon 1272 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1273 temperature and allows controlling fan speeds of Dell laptops via 1274 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1275 it reports also power and hotkey status. For fan speed control is 1276 needed userspace package i8kutils. 1277 1278 Say Y if you intend to run this kernel on old Dell laptops or want to 1279 use userspace package i8kutils. 1280 Say N otherwise. 1281 1282config X86_REBOOTFIXUPS 1283 bool "Enable X86 board specific fixups for reboot" 1284 depends on X86_32 1285 help 1286 This enables chipset and/or board specific fixups to be done 1287 in order to get reboot to work correctly. This is only needed on 1288 some combinations of hardware and BIOS. The symptom, for which 1289 this config is intended, is when reboot ends with a stalled/hung 1290 system. 1291 1292 Currently, the only fixup is for the Geode machines using 1293 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1294 1295 Say Y if you want to enable the fixup. Currently, it's safe to 1296 enable this option even if you don't need it. 1297 Say N otherwise. 1298 1299config MICROCODE 1300 bool "CPU microcode loading support" 1301 default y 1302 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1303 help 1304 If you say Y here, you will be able to update the microcode on 1305 Intel and AMD processors. The Intel support is for the IA32 family, 1306 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1307 AMD support is for families 0x10 and later. You will obviously need 1308 the actual microcode binary data itself which is not shipped with 1309 the Linux kernel. 1310 1311 The preferred method to load microcode from a detached initrd is described 1312 in Documentation/x86/microcode.rst. For that you need to enable 1313 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1314 initrd for microcode blobs. 1315 1316 In addition, you can build the microcode into the kernel. For that you 1317 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1318 config option. 1319 1320config MICROCODE_INTEL 1321 bool "Intel microcode loading support" 1322 depends on MICROCODE 1323 default MICROCODE 1324 help 1325 This options enables microcode patch loading support for Intel 1326 processors. 1327 1328 For the current Intel microcode data package go to 1329 <https://downloadcenter.intel.com> and search for 1330 'Linux Processor Microcode Data File'. 1331 1332config MICROCODE_AMD 1333 bool "AMD microcode loading support" 1334 depends on MICROCODE 1335 help 1336 If you select this option, microcode patch loading support for AMD 1337 processors will be enabled. 1338 1339config MICROCODE_OLD_INTERFACE 1340 bool "Ancient loading interface (DEPRECATED)" 1341 default n 1342 depends on MICROCODE 1343 help 1344 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1345 which was used by userspace tools like iucode_tool and microcode.ctl. 1346 It is inadequate because it runs too late to be able to properly 1347 load microcode on a machine and it needs special tools. Instead, you 1348 should've switched to the early loading method with the initrd or 1349 builtin microcode by now: Documentation/x86/microcode.rst 1350 1351config X86_MSR 1352 tristate "/dev/cpu/*/msr - Model-specific register support" 1353 help 1354 This device gives privileged processes access to the x86 1355 Model-Specific Registers (MSRs). It is a character device with 1356 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1357 MSR accesses are directed to a specific CPU on multi-processor 1358 systems. 1359 1360config X86_CPUID 1361 tristate "/dev/cpu/*/cpuid - CPU information support" 1362 help 1363 This device gives processes access to the x86 CPUID instruction to 1364 be executed on a specific processor. It is a character device 1365 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1366 /dev/cpu/31/cpuid. 1367 1368choice 1369 prompt "High Memory Support" 1370 default HIGHMEM4G 1371 depends on X86_32 1372 1373config NOHIGHMEM 1374 bool "off" 1375 help 1376 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1377 However, the address space of 32-bit x86 processors is only 4 1378 Gigabytes large. That means that, if you have a large amount of 1379 physical memory, not all of it can be "permanently mapped" by the 1380 kernel. The physical memory that's not permanently mapped is called 1381 "high memory". 1382 1383 If you are compiling a kernel which will never run on a machine with 1384 more than 1 Gigabyte total physical RAM, answer "off" here (default 1385 choice and suitable for most users). This will result in a "3GB/1GB" 1386 split: 3GB are mapped so that each process sees a 3GB virtual memory 1387 space and the remaining part of the 4GB virtual memory space is used 1388 by the kernel to permanently map as much physical memory as 1389 possible. 1390 1391 If the machine has between 1 and 4 Gigabytes physical RAM, then 1392 answer "4GB" here. 1393 1394 If more than 4 Gigabytes is used then answer "64GB" here. This 1395 selection turns Intel PAE (Physical Address Extension) mode on. 1396 PAE implements 3-level paging on IA32 processors. PAE is fully 1397 supported by Linux, PAE mode is implemented on all recent Intel 1398 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1399 then the kernel will not boot on CPUs that don't support PAE! 1400 1401 The actual amount of total physical memory will either be 1402 auto detected or can be forced by using a kernel command line option 1403 such as "mem=256M". (Try "man bootparam" or see the documentation of 1404 your boot loader (lilo or loadlin) about how to pass options to the 1405 kernel at boot time.) 1406 1407 If unsure, say "off". 1408 1409config HIGHMEM4G 1410 bool "4GB" 1411 help 1412 Select this if you have a 32-bit processor and between 1 and 4 1413 gigabytes of physical RAM. 1414 1415config HIGHMEM64G 1416 bool "64GB" 1417 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1418 select X86_PAE 1419 help 1420 Select this if you have a 32-bit processor and more than 4 1421 gigabytes of physical RAM. 1422 1423endchoice 1424 1425choice 1426 prompt "Memory split" if EXPERT 1427 default VMSPLIT_3G 1428 depends on X86_32 1429 help 1430 Select the desired split between kernel and user memory. 1431 1432 If the address range available to the kernel is less than the 1433 physical memory installed, the remaining memory will be available 1434 as "high memory". Accessing high memory is a little more costly 1435 than low memory, as it needs to be mapped into the kernel first. 1436 Note that increasing the kernel address space limits the range 1437 available to user programs, making the address space there 1438 tighter. Selecting anything other than the default 3G/1G split 1439 will also likely make your kernel incompatible with binary-only 1440 kernel modules. 1441 1442 If you are not absolutely sure what you are doing, leave this 1443 option alone! 1444 1445 config VMSPLIT_3G 1446 bool "3G/1G user/kernel split" 1447 config VMSPLIT_3G_OPT 1448 depends on !X86_PAE 1449 bool "3G/1G user/kernel split (for full 1G low memory)" 1450 config VMSPLIT_2G 1451 bool "2G/2G user/kernel split" 1452 config VMSPLIT_2G_OPT 1453 depends on !X86_PAE 1454 bool "2G/2G user/kernel split (for full 2G low memory)" 1455 config VMSPLIT_1G 1456 bool "1G/3G user/kernel split" 1457endchoice 1458 1459config PAGE_OFFSET 1460 hex 1461 default 0xB0000000 if VMSPLIT_3G_OPT 1462 default 0x80000000 if VMSPLIT_2G 1463 default 0x78000000 if VMSPLIT_2G_OPT 1464 default 0x40000000 if VMSPLIT_1G 1465 default 0xC0000000 1466 depends on X86_32 1467 1468config HIGHMEM 1469 def_bool y 1470 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1471 1472config X86_PAE 1473 bool "PAE (Physical Address Extension) Support" 1474 depends on X86_32 && !HIGHMEM4G 1475 select PHYS_ADDR_T_64BIT 1476 select SWIOTLB 1477 help 1478 PAE is required for NX support, and furthermore enables 1479 larger swapspace support for non-overcommit purposes. It 1480 has the cost of more pagetable lookup overhead, and also 1481 consumes more pagetable space per process. 1482 1483config X86_5LEVEL 1484 bool "Enable 5-level page tables support" 1485 default y 1486 select DYNAMIC_MEMORY_LAYOUT 1487 select SPARSEMEM_VMEMMAP 1488 depends on X86_64 1489 help 1490 5-level paging enables access to larger address space: 1491 upto 128 PiB of virtual address space and 4 PiB of 1492 physical address space. 1493 1494 It will be supported by future Intel CPUs. 1495 1496 A kernel with the option enabled can be booted on machines that 1497 support 4- or 5-level paging. 1498 1499 See Documentation/x86/x86_64/5level-paging.rst for more 1500 information. 1501 1502 Say N if unsure. 1503 1504config X86_DIRECT_GBPAGES 1505 def_bool y 1506 depends on X86_64 1507 help 1508 Certain kernel features effectively disable kernel 1509 linear 1 GB mappings (even if the CPU otherwise 1510 supports them), so don't confuse the user by printing 1511 that we have them enabled. 1512 1513config X86_CPA_STATISTICS 1514 bool "Enable statistic for Change Page Attribute" 1515 depends on DEBUG_FS 1516 help 1517 Expose statistics about the Change Page Attribute mechanism, which 1518 helps to determine the effectiveness of preserving large and huge 1519 page mappings when mapping protections are changed. 1520 1521config AMD_MEM_ENCRYPT 1522 bool "AMD Secure Memory Encryption (SME) support" 1523 depends on X86_64 && CPU_SUP_AMD 1524 select DMA_COHERENT_POOL 1525 select DYNAMIC_PHYSICAL_MASK 1526 select ARCH_USE_MEMREMAP_PROT 1527 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1528 select INSTRUCTION_DECODER 1529 help 1530 Say yes to enable support for the encryption of system memory. 1531 This requires an AMD processor that supports Secure Memory 1532 Encryption (SME). 1533 1534config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1535 bool "Activate AMD Secure Memory Encryption (SME) by default" 1536 default y 1537 depends on AMD_MEM_ENCRYPT 1538 help 1539 Say yes to have system memory encrypted by default if running on 1540 an AMD processor that supports Secure Memory Encryption (SME). 1541 1542 If set to Y, then the encryption of system memory can be 1543 deactivated with the mem_encrypt=off command line option. 1544 1545 If set to N, then the encryption of system memory can be 1546 activated with the mem_encrypt=on command line option. 1547 1548# Common NUMA Features 1549config NUMA 1550 bool "NUMA Memory Allocation and Scheduler Support" 1551 depends on SMP 1552 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1553 default y if X86_BIGSMP 1554 help 1555 Enable NUMA (Non-Uniform Memory Access) support. 1556 1557 The kernel will try to allocate memory used by a CPU on the 1558 local memory controller of the CPU and add some more 1559 NUMA awareness to the kernel. 1560 1561 For 64-bit this is recommended if the system is Intel Core i7 1562 (or later), AMD Opteron, or EM64T NUMA. 1563 1564 For 32-bit this is only needed if you boot a 32-bit 1565 kernel on a 64-bit NUMA platform. 1566 1567 Otherwise, you should say N. 1568 1569config AMD_NUMA 1570 def_bool y 1571 prompt "Old style AMD Opteron NUMA detection" 1572 depends on X86_64 && NUMA && PCI 1573 help 1574 Enable AMD NUMA node topology detection. You should say Y here if 1575 you have a multi processor AMD system. This uses an old method to 1576 read the NUMA configuration directly from the builtin Northbridge 1577 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1578 which also takes priority if both are compiled in. 1579 1580config X86_64_ACPI_NUMA 1581 def_bool y 1582 prompt "ACPI NUMA detection" 1583 depends on X86_64 && NUMA && ACPI && PCI 1584 select ACPI_NUMA 1585 help 1586 Enable ACPI SRAT based node topology detection. 1587 1588config NUMA_EMU 1589 bool "NUMA emulation" 1590 depends on NUMA 1591 help 1592 Enable NUMA emulation. A flat machine will be split 1593 into virtual nodes when booted with "numa=fake=N", where N is the 1594 number of nodes. This is only useful for debugging. 1595 1596config NODES_SHIFT 1597 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1598 range 1 10 1599 default "10" if MAXSMP 1600 default "6" if X86_64 1601 default "3" 1602 depends on NEED_MULTIPLE_NODES 1603 help 1604 Specify the maximum number of NUMA Nodes available on the target 1605 system. Increases memory reserved to accommodate various tables. 1606 1607config ARCH_FLATMEM_ENABLE 1608 def_bool y 1609 depends on X86_32 && !NUMA 1610 1611config ARCH_SPARSEMEM_ENABLE 1612 def_bool y 1613 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1614 select SPARSEMEM_STATIC if X86_32 1615 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1616 1617config ARCH_SPARSEMEM_DEFAULT 1618 def_bool X86_64 || (NUMA && X86_32) 1619 1620config ARCH_SELECT_MEMORY_MODEL 1621 def_bool y 1622 depends on ARCH_SPARSEMEM_ENABLE 1623 1624config ARCH_MEMORY_PROBE 1625 bool "Enable sysfs memory/probe interface" 1626 depends on X86_64 && MEMORY_HOTPLUG 1627 help 1628 This option enables a sysfs memory/probe interface for testing. 1629 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1630 If you are unsure how to answer this question, answer N. 1631 1632config ARCH_PROC_KCORE_TEXT 1633 def_bool y 1634 depends on X86_64 && PROC_KCORE 1635 1636config ILLEGAL_POINTER_VALUE 1637 hex 1638 default 0 if X86_32 1639 default 0xdead000000000000 if X86_64 1640 1641config X86_PMEM_LEGACY_DEVICE 1642 bool 1643 1644config X86_PMEM_LEGACY 1645 tristate "Support non-standard NVDIMMs and ADR protected memory" 1646 depends on PHYS_ADDR_T_64BIT 1647 depends on BLK_DEV 1648 select X86_PMEM_LEGACY_DEVICE 1649 select NUMA_KEEP_MEMINFO if NUMA 1650 select LIBNVDIMM 1651 help 1652 Treat memory marked using the non-standard e820 type of 12 as used 1653 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1654 The kernel will offer these regions to the 'pmem' driver so 1655 they can be used for persistent storage. 1656 1657 Say Y if unsure. 1658 1659config HIGHPTE 1660 bool "Allocate 3rd-level pagetables from highmem" 1661 depends on HIGHMEM 1662 help 1663 The VM uses one page table entry for each page of physical memory. 1664 For systems with a lot of RAM, this can be wasteful of precious 1665 low memory. Setting this option will put user-space page table 1666 entries in high memory. 1667 1668config X86_CHECK_BIOS_CORRUPTION 1669 bool "Check for low memory corruption" 1670 help 1671 Periodically check for memory corruption in low memory, which 1672 is suspected to be caused by BIOS. Even when enabled in the 1673 configuration, it is disabled at runtime. Enable it by 1674 setting "memory_corruption_check=1" on the kernel command 1675 line. By default it scans the low 64k of memory every 60 1676 seconds; see the memory_corruption_check_size and 1677 memory_corruption_check_period parameters in 1678 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1679 1680 When enabled with the default parameters, this option has 1681 almost no overhead, as it reserves a relatively small amount 1682 of memory and scans it infrequently. It both detects corruption 1683 and prevents it from affecting the running system. 1684 1685 It is, however, intended as a diagnostic tool; if repeatable 1686 BIOS-originated corruption always affects the same memory, 1687 you can use memmap= to prevent the kernel from using that 1688 memory. 1689 1690config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1691 bool "Set the default setting of memory_corruption_check" 1692 depends on X86_CHECK_BIOS_CORRUPTION 1693 default y 1694 help 1695 Set whether the default state of memory_corruption_check is 1696 on or off. 1697 1698config X86_RESERVE_LOW 1699 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1700 default 64 1701 range 4 640 1702 help 1703 Specify the amount of low memory to reserve for the BIOS. 1704 1705 The first page contains BIOS data structures that the kernel 1706 must not use, so that page must always be reserved. 1707 1708 By default we reserve the first 64K of physical RAM, as a 1709 number of BIOSes are known to corrupt that memory range 1710 during events such as suspend/resume or monitor cable 1711 insertion, so it must not be used by the kernel. 1712 1713 You can set this to 4 if you are absolutely sure that you 1714 trust the BIOS to get all its memory reservations and usages 1715 right. If you know your BIOS have problems beyond the 1716 default 64K area, you can set this to 640 to avoid using the 1717 entire low memory range. 1718 1719 If you have doubts about the BIOS (e.g. suspend/resume does 1720 not work or there's kernel crashes after certain hardware 1721 hotplug events) then you might want to enable 1722 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1723 typical corruption patterns. 1724 1725 Leave this to the default value of 64 if you are unsure. 1726 1727config MATH_EMULATION 1728 bool 1729 depends on MODIFY_LDT_SYSCALL 1730 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1731 help 1732 Linux can emulate a math coprocessor (used for floating point 1733 operations) if you don't have one. 486DX and Pentium processors have 1734 a math coprocessor built in, 486SX and 386 do not, unless you added 1735 a 487DX or 387, respectively. (The messages during boot time can 1736 give you some hints here ["man dmesg"].) Everyone needs either a 1737 coprocessor or this emulation. 1738 1739 If you don't have a math coprocessor, you need to say Y here; if you 1740 say Y here even though you have a coprocessor, the coprocessor will 1741 be used nevertheless. (This behavior can be changed with the kernel 1742 command line option "no387", which comes handy if your coprocessor 1743 is broken. Try "man bootparam" or see the documentation of your boot 1744 loader (lilo or loadlin) about how to pass options to the kernel at 1745 boot time.) This means that it is a good idea to say Y here if you 1746 intend to use this kernel on different machines. 1747 1748 More information about the internals of the Linux math coprocessor 1749 emulation can be found in <file:arch/x86/math-emu/README>. 1750 1751 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1752 kernel, it won't hurt. 1753 1754config MTRR 1755 def_bool y 1756 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1757 help 1758 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1759 the Memory Type Range Registers (MTRRs) may be used to control 1760 processor access to memory ranges. This is most useful if you have 1761 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1762 allows bus write transfers to be combined into a larger transfer 1763 before bursting over the PCI/AGP bus. This can increase performance 1764 of image write operations 2.5 times or more. Saying Y here creates a 1765 /proc/mtrr file which may be used to manipulate your processor's 1766 MTRRs. Typically the X server should use this. 1767 1768 This code has a reasonably generic interface so that similar 1769 control registers on other processors can be easily supported 1770 as well: 1771 1772 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1773 Registers (ARRs) which provide a similar functionality to MTRRs. For 1774 these, the ARRs are used to emulate the MTRRs. 1775 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1776 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1777 write-combining. All of these processors are supported by this code 1778 and it makes sense to say Y here if you have one of them. 1779 1780 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1781 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1782 can lead to all sorts of problems, so it's good to say Y here. 1783 1784 You can safely say Y even if your machine doesn't have MTRRs, you'll 1785 just add about 9 KB to your kernel. 1786 1787 See <file:Documentation/x86/mtrr.rst> for more information. 1788 1789config MTRR_SANITIZER 1790 def_bool y 1791 prompt "MTRR cleanup support" 1792 depends on MTRR 1793 help 1794 Convert MTRR layout from continuous to discrete, so X drivers can 1795 add writeback entries. 1796 1797 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1798 The largest mtrr entry size for a continuous block can be set with 1799 mtrr_chunk_size. 1800 1801 If unsure, say Y. 1802 1803config MTRR_SANITIZER_ENABLE_DEFAULT 1804 int "MTRR cleanup enable value (0-1)" 1805 range 0 1 1806 default "0" 1807 depends on MTRR_SANITIZER 1808 help 1809 Enable mtrr cleanup default value 1810 1811config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1812 int "MTRR cleanup spare reg num (0-7)" 1813 range 0 7 1814 default "1" 1815 depends on MTRR_SANITIZER 1816 help 1817 mtrr cleanup spare entries default, it can be changed via 1818 mtrr_spare_reg_nr=N on the kernel command line. 1819 1820config X86_PAT 1821 def_bool y 1822 prompt "x86 PAT support" if EXPERT 1823 depends on MTRR 1824 help 1825 Use PAT attributes to setup page level cache control. 1826 1827 PATs are the modern equivalents of MTRRs and are much more 1828 flexible than MTRRs. 1829 1830 Say N here if you see bootup problems (boot crash, boot hang, 1831 spontaneous reboots) or a non-working video driver. 1832 1833 If unsure, say Y. 1834 1835config ARCH_USES_PG_UNCACHED 1836 def_bool y 1837 depends on X86_PAT 1838 1839config ARCH_RANDOM 1840 def_bool y 1841 prompt "x86 architectural random number generator" if EXPERT 1842 help 1843 Enable the x86 architectural RDRAND instruction 1844 (Intel Bull Mountain technology) to generate random numbers. 1845 If supported, this is a high bandwidth, cryptographically 1846 secure hardware random number generator. 1847 1848config X86_SMAP 1849 def_bool y 1850 prompt "Supervisor Mode Access Prevention" if EXPERT 1851 help 1852 Supervisor Mode Access Prevention (SMAP) is a security 1853 feature in newer Intel processors. There is a small 1854 performance cost if this enabled and turned on; there is 1855 also a small increase in the kernel size if this is enabled. 1856 1857 If unsure, say Y. 1858 1859config X86_UMIP 1860 def_bool y 1861 prompt "User Mode Instruction Prevention" if EXPERT 1862 help 1863 User Mode Instruction Prevention (UMIP) is a security feature in 1864 some x86 processors. If enabled, a general protection fault is 1865 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1866 executed in user mode. These instructions unnecessarily expose 1867 information about the hardware state. 1868 1869 The vast majority of applications do not use these instructions. 1870 For the very few that do, software emulation is provided in 1871 specific cases in protected and virtual-8086 modes. Emulated 1872 results are dummy. 1873 1874config X86_INTEL_MEMORY_PROTECTION_KEYS 1875 prompt "Memory Protection Keys" 1876 def_bool y 1877 # Note: only available in 64-bit mode 1878 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1879 select ARCH_USES_HIGH_VMA_FLAGS 1880 select ARCH_HAS_PKEYS 1881 help 1882 Memory Protection Keys provides a mechanism for enforcing 1883 page-based protections, but without requiring modification of the 1884 page tables when an application changes protection domains. 1885 1886 For details, see Documentation/core-api/protection-keys.rst 1887 1888 If unsure, say y. 1889 1890choice 1891 prompt "TSX enable mode" 1892 depends on CPU_SUP_INTEL 1893 default X86_INTEL_TSX_MODE_OFF 1894 help 1895 Intel's TSX (Transactional Synchronization Extensions) feature 1896 allows to optimize locking protocols through lock elision which 1897 can lead to a noticeable performance boost. 1898 1899 On the other hand it has been shown that TSX can be exploited 1900 to form side channel attacks (e.g. TAA) and chances are there 1901 will be more of those attacks discovered in the future. 1902 1903 Therefore TSX is not enabled by default (aka tsx=off). An admin 1904 might override this decision by tsx=on the command line parameter. 1905 Even with TSX enabled, the kernel will attempt to enable the best 1906 possible TAA mitigation setting depending on the microcode available 1907 for the particular machine. 1908 1909 This option allows to set the default tsx mode between tsx=on, =off 1910 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1911 details. 1912 1913 Say off if not sure, auto if TSX is in use but it should be used on safe 1914 platforms or on if TSX is in use and the security aspect of tsx is not 1915 relevant. 1916 1917config X86_INTEL_TSX_MODE_OFF 1918 bool "off" 1919 help 1920 TSX is disabled if possible - equals to tsx=off command line parameter. 1921 1922config X86_INTEL_TSX_MODE_ON 1923 bool "on" 1924 help 1925 TSX is always enabled on TSX capable HW - equals the tsx=on command 1926 line parameter. 1927 1928config X86_INTEL_TSX_MODE_AUTO 1929 bool "auto" 1930 help 1931 TSX is enabled on TSX capable HW that is believed to be safe against 1932 side channel attacks- equals the tsx=auto command line parameter. 1933endchoice 1934 1935config X86_SGX 1936 bool "Software Guard eXtensions (SGX)" 1937 depends on X86_64 && CPU_SUP_INTEL 1938 depends on CRYPTO=y 1939 depends on CRYPTO_SHA256=y 1940 select SRCU 1941 select MMU_NOTIFIER 1942 help 1943 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1944 that can be used by applications to set aside private regions of code 1945 and data, referred to as enclaves. An enclave's private memory can 1946 only be accessed by code running within the enclave. Accesses from 1947 outside the enclave, including other enclaves, are disallowed by 1948 hardware. 1949 1950 If unsure, say N. 1951 1952config EFI 1953 bool "EFI runtime service support" 1954 depends on ACPI 1955 select UCS2_STRING 1956 select EFI_RUNTIME_WRAPPERS 1957 help 1958 This enables the kernel to use EFI runtime services that are 1959 available (such as the EFI variable services). 1960 1961 This option is only useful on systems that have EFI firmware. 1962 In addition, you should use the latest ELILO loader available 1963 at <http://elilo.sourceforge.net> in order to take advantage 1964 of EFI runtime services. However, even with this option, the 1965 resultant kernel should continue to boot on existing non-EFI 1966 platforms. 1967 1968config EFI_STUB 1969 bool "EFI stub support" 1970 depends on EFI && !X86_USE_3DNOW 1971 depends on $(cc-option,-mabi=ms) || X86_32 1972 select RELOCATABLE 1973 help 1974 This kernel feature allows a bzImage to be loaded directly 1975 by EFI firmware without the use of a bootloader. 1976 1977 See Documentation/admin-guide/efi-stub.rst for more information. 1978 1979config EFI_MIXED 1980 bool "EFI mixed-mode support" 1981 depends on EFI_STUB && X86_64 1982 help 1983 Enabling this feature allows a 64-bit kernel to be booted 1984 on a 32-bit firmware, provided that your CPU supports 64-bit 1985 mode. 1986 1987 Note that it is not possible to boot a mixed-mode enabled 1988 kernel via the EFI boot stub - a bootloader that supports 1989 the EFI handover protocol must be used. 1990 1991 If unsure, say N. 1992 1993source "kernel/Kconfig.hz" 1994 1995config KEXEC 1996 bool "kexec system call" 1997 select KEXEC_CORE 1998 help 1999 kexec is a system call that implements the ability to shutdown your 2000 current kernel, and to start another kernel. It is like a reboot 2001 but it is independent of the system firmware. And like a reboot 2002 you can start any kernel with it, not just Linux. 2003 2004 The name comes from the similarity to the exec system call. 2005 2006 It is an ongoing process to be certain the hardware in a machine 2007 is properly shutdown, so do not be surprised if this code does not 2008 initially work for you. As of this writing the exact hardware 2009 interface is strongly in flux, so no good recommendation can be 2010 made. 2011 2012config KEXEC_FILE 2013 bool "kexec file based system call" 2014 select KEXEC_CORE 2015 select BUILD_BIN2C 2016 depends on X86_64 2017 depends on CRYPTO=y 2018 depends on CRYPTO_SHA256=y 2019 help 2020 This is new version of kexec system call. This system call is 2021 file based and takes file descriptors as system call argument 2022 for kernel and initramfs as opposed to list of segments as 2023 accepted by previous system call. 2024 2025config ARCH_HAS_KEXEC_PURGATORY 2026 def_bool KEXEC_FILE 2027 2028config KEXEC_SIG 2029 bool "Verify kernel signature during kexec_file_load() syscall" 2030 depends on KEXEC_FILE 2031 help 2032 2033 This option makes the kexec_file_load() syscall check for a valid 2034 signature of the kernel image. The image can still be loaded without 2035 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2036 there's a signature that we can check, then it must be valid. 2037 2038 In addition to this option, you need to enable signature 2039 verification for the corresponding kernel image type being 2040 loaded in order for this to work. 2041 2042config KEXEC_SIG_FORCE 2043 bool "Require a valid signature in kexec_file_load() syscall" 2044 depends on KEXEC_SIG 2045 help 2046 This option makes kernel signature verification mandatory for 2047 the kexec_file_load() syscall. 2048 2049config KEXEC_BZIMAGE_VERIFY_SIG 2050 bool "Enable bzImage signature verification support" 2051 depends on KEXEC_SIG 2052 depends on SIGNED_PE_FILE_VERIFICATION 2053 select SYSTEM_TRUSTED_KEYRING 2054 help 2055 Enable bzImage signature verification support. 2056 2057config CRASH_DUMP 2058 bool "kernel crash dumps" 2059 depends on X86_64 || (X86_32 && HIGHMEM) 2060 help 2061 Generate crash dump after being started by kexec. 2062 This should be normally only set in special crash dump kernels 2063 which are loaded in the main kernel with kexec-tools into 2064 a specially reserved region and then later executed after 2065 a crash by kdump/kexec. The crash dump kernel must be compiled 2066 to a memory address not used by the main kernel or BIOS using 2067 PHYSICAL_START, or it must be built as a relocatable image 2068 (CONFIG_RELOCATABLE=y). 2069 For more details see Documentation/admin-guide/kdump/kdump.rst 2070 2071config KEXEC_JUMP 2072 bool "kexec jump" 2073 depends on KEXEC && HIBERNATION 2074 help 2075 Jump between original kernel and kexeced kernel and invoke 2076 code in physical address mode via KEXEC 2077 2078config PHYSICAL_START 2079 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2080 default "0x1000000" 2081 help 2082 This gives the physical address where the kernel is loaded. 2083 2084 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2085 bzImage will decompress itself to above physical address and 2086 run from there. Otherwise, bzImage will run from the address where 2087 it has been loaded by the boot loader and will ignore above physical 2088 address. 2089 2090 In normal kdump cases one does not have to set/change this option 2091 as now bzImage can be compiled as a completely relocatable image 2092 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2093 address. This option is mainly useful for the folks who don't want 2094 to use a bzImage for capturing the crash dump and want to use a 2095 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2096 to be specifically compiled to run from a specific memory area 2097 (normally a reserved region) and this option comes handy. 2098 2099 So if you are using bzImage for capturing the crash dump, 2100 leave the value here unchanged to 0x1000000 and set 2101 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2102 for capturing the crash dump change this value to start of 2103 the reserved region. In other words, it can be set based on 2104 the "X" value as specified in the "crashkernel=YM@XM" 2105 command line boot parameter passed to the panic-ed 2106 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2107 for more details about crash dumps. 2108 2109 Usage of bzImage for capturing the crash dump is recommended as 2110 one does not have to build two kernels. Same kernel can be used 2111 as production kernel and capture kernel. Above option should have 2112 gone away after relocatable bzImage support is introduced. But it 2113 is present because there are users out there who continue to use 2114 vmlinux for dump capture. This option should go away down the 2115 line. 2116 2117 Don't change this unless you know what you are doing. 2118 2119config RELOCATABLE 2120 bool "Build a relocatable kernel" 2121 default y 2122 help 2123 This builds a kernel image that retains relocation information 2124 so it can be loaded someplace besides the default 1MB. 2125 The relocations tend to make the kernel binary about 10% larger, 2126 but are discarded at runtime. 2127 2128 One use is for the kexec on panic case where the recovery kernel 2129 must live at a different physical address than the primary 2130 kernel. 2131 2132 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2133 it has been loaded at and the compile time physical address 2134 (CONFIG_PHYSICAL_START) is used as the minimum location. 2135 2136config RANDOMIZE_BASE 2137 bool "Randomize the address of the kernel image (KASLR)" 2138 depends on RELOCATABLE 2139 default y 2140 help 2141 In support of Kernel Address Space Layout Randomization (KASLR), 2142 this randomizes the physical address at which the kernel image 2143 is decompressed and the virtual address where the kernel 2144 image is mapped, as a security feature that deters exploit 2145 attempts relying on knowledge of the location of kernel 2146 code internals. 2147 2148 On 64-bit, the kernel physical and virtual addresses are 2149 randomized separately. The physical address will be anywhere 2150 between 16MB and the top of physical memory (up to 64TB). The 2151 virtual address will be randomized from 16MB up to 1GB (9 bits 2152 of entropy). Note that this also reduces the memory space 2153 available to kernel modules from 1.5GB to 1GB. 2154 2155 On 32-bit, the kernel physical and virtual addresses are 2156 randomized together. They will be randomized from 16MB up to 2157 512MB (8 bits of entropy). 2158 2159 Entropy is generated using the RDRAND instruction if it is 2160 supported. If RDTSC is supported, its value is mixed into 2161 the entropy pool as well. If neither RDRAND nor RDTSC are 2162 supported, then entropy is read from the i8254 timer. The 2163 usable entropy is limited by the kernel being built using 2164 2GB addressing, and that PHYSICAL_ALIGN must be at a 2165 minimum of 2MB. As a result, only 10 bits of entropy are 2166 theoretically possible, but the implementations are further 2167 limited due to memory layouts. 2168 2169 If unsure, say Y. 2170 2171# Relocation on x86 needs some additional build support 2172config X86_NEED_RELOCS 2173 def_bool y 2174 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2175 2176config PHYSICAL_ALIGN 2177 hex "Alignment value to which kernel should be aligned" 2178 default "0x200000" 2179 range 0x2000 0x1000000 if X86_32 2180 range 0x200000 0x1000000 if X86_64 2181 help 2182 This value puts the alignment restrictions on physical address 2183 where kernel is loaded and run from. Kernel is compiled for an 2184 address which meets above alignment restriction. 2185 2186 If bootloader loads the kernel at a non-aligned address and 2187 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2188 address aligned to above value and run from there. 2189 2190 If bootloader loads the kernel at a non-aligned address and 2191 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2192 load address and decompress itself to the address it has been 2193 compiled for and run from there. The address for which kernel is 2194 compiled already meets above alignment restrictions. Hence the 2195 end result is that kernel runs from a physical address meeting 2196 above alignment restrictions. 2197 2198 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2199 this value must be a multiple of 0x200000. 2200 2201 Don't change this unless you know what you are doing. 2202 2203config DYNAMIC_MEMORY_LAYOUT 2204 bool 2205 help 2206 This option makes base addresses of vmalloc and vmemmap as well as 2207 __PAGE_OFFSET movable during boot. 2208 2209config RANDOMIZE_MEMORY 2210 bool "Randomize the kernel memory sections" 2211 depends on X86_64 2212 depends on RANDOMIZE_BASE 2213 select DYNAMIC_MEMORY_LAYOUT 2214 default RANDOMIZE_BASE 2215 help 2216 Randomizes the base virtual address of kernel memory sections 2217 (physical memory mapping, vmalloc & vmemmap). This security feature 2218 makes exploits relying on predictable memory locations less reliable. 2219 2220 The order of allocations remains unchanged. Entropy is generated in 2221 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2222 configuration have in average 30,000 different possible virtual 2223 addresses for each memory section. 2224 2225 If unsure, say Y. 2226 2227config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2228 hex "Physical memory mapping padding" if EXPERT 2229 depends on RANDOMIZE_MEMORY 2230 default "0xa" if MEMORY_HOTPLUG 2231 default "0x0" 2232 range 0x1 0x40 if MEMORY_HOTPLUG 2233 range 0x0 0x40 2234 help 2235 Define the padding in terabytes added to the existing physical 2236 memory size during kernel memory randomization. It is useful 2237 for memory hotplug support but reduces the entropy available for 2238 address randomization. 2239 2240 If unsure, leave at the default value. 2241 2242config HOTPLUG_CPU 2243 def_bool y 2244 depends on SMP 2245 2246config BOOTPARAM_HOTPLUG_CPU0 2247 bool "Set default setting of cpu0_hotpluggable" 2248 depends on HOTPLUG_CPU 2249 help 2250 Set whether default state of cpu0_hotpluggable is on or off. 2251 2252 Say Y here to enable CPU0 hotplug by default. If this switch 2253 is turned on, there is no need to give cpu0_hotplug kernel 2254 parameter and the CPU0 hotplug feature is enabled by default. 2255 2256 Please note: there are two known CPU0 dependencies if you want 2257 to enable the CPU0 hotplug feature either by this switch or by 2258 cpu0_hotplug kernel parameter. 2259 2260 First, resume from hibernate or suspend always starts from CPU0. 2261 So hibernate and suspend are prevented if CPU0 is offline. 2262 2263 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2264 offline if any interrupt can not migrate out of CPU0. There may 2265 be other CPU0 dependencies. 2266 2267 Please make sure the dependencies are under your control before 2268 you enable this feature. 2269 2270 Say N if you don't want to enable CPU0 hotplug feature by default. 2271 You still can enable the CPU0 hotplug feature at boot by kernel 2272 parameter cpu0_hotplug. 2273 2274config DEBUG_HOTPLUG_CPU0 2275 def_bool n 2276 prompt "Debug CPU0 hotplug" 2277 depends on HOTPLUG_CPU 2278 help 2279 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2280 soon as possible and boots up userspace with CPU0 offlined. User 2281 can online CPU0 back after boot time. 2282 2283 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2284 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2285 compilation or giving cpu0_hotplug kernel parameter at boot. 2286 2287 If unsure, say N. 2288 2289config COMPAT_VDSO 2290 def_bool n 2291 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2292 depends on COMPAT_32 2293 help 2294 Certain buggy versions of glibc will crash if they are 2295 presented with a 32-bit vDSO that is not mapped at the address 2296 indicated in its segment table. 2297 2298 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2299 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2300 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2301 the only released version with the bug, but OpenSUSE 9 2302 contains a buggy "glibc 2.3.2". 2303 2304 The symptom of the bug is that everything crashes on startup, saying: 2305 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2306 2307 Saying Y here changes the default value of the vdso32 boot 2308 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2309 This works around the glibc bug but hurts performance. 2310 2311 If unsure, say N: if you are compiling your own kernel, you 2312 are unlikely to be using a buggy version of glibc. 2313 2314choice 2315 prompt "vsyscall table for legacy applications" 2316 depends on X86_64 2317 default LEGACY_VSYSCALL_XONLY 2318 help 2319 Legacy user code that does not know how to find the vDSO expects 2320 to be able to issue three syscalls by calling fixed addresses in 2321 kernel space. Since this location is not randomized with ASLR, 2322 it can be used to assist security vulnerability exploitation. 2323 2324 This setting can be changed at boot time via the kernel command 2325 line parameter vsyscall=[emulate|xonly|none]. 2326 2327 On a system with recent enough glibc (2.14 or newer) and no 2328 static binaries, you can say None without a performance penalty 2329 to improve security. 2330 2331 If unsure, select "Emulate execution only". 2332 2333 config LEGACY_VSYSCALL_EMULATE 2334 bool "Full emulation" 2335 help 2336 The kernel traps and emulates calls into the fixed vsyscall 2337 address mapping. This makes the mapping non-executable, but 2338 it still contains readable known contents, which could be 2339 used in certain rare security vulnerability exploits. This 2340 configuration is recommended when using legacy userspace 2341 that still uses vsyscalls along with legacy binary 2342 instrumentation tools that require code to be readable. 2343 2344 An example of this type of legacy userspace is running 2345 Pin on an old binary that still uses vsyscalls. 2346 2347 config LEGACY_VSYSCALL_XONLY 2348 bool "Emulate execution only" 2349 help 2350 The kernel traps and emulates calls into the fixed vsyscall 2351 address mapping and does not allow reads. This 2352 configuration is recommended when userspace might use the 2353 legacy vsyscall area but support for legacy binary 2354 instrumentation of legacy code is not needed. It mitigates 2355 certain uses of the vsyscall area as an ASLR-bypassing 2356 buffer. 2357 2358 config LEGACY_VSYSCALL_NONE 2359 bool "None" 2360 help 2361 There will be no vsyscall mapping at all. This will 2362 eliminate any risk of ASLR bypass due to the vsyscall 2363 fixed address mapping. Attempts to use the vsyscalls 2364 will be reported to dmesg, so that either old or 2365 malicious userspace programs can be identified. 2366 2367endchoice 2368 2369config CMDLINE_BOOL 2370 bool "Built-in kernel command line" 2371 help 2372 Allow for specifying boot arguments to the kernel at 2373 build time. On some systems (e.g. embedded ones), it is 2374 necessary or convenient to provide some or all of the 2375 kernel boot arguments with the kernel itself (that is, 2376 to not rely on the boot loader to provide them.) 2377 2378 To compile command line arguments into the kernel, 2379 set this option to 'Y', then fill in the 2380 boot arguments in CONFIG_CMDLINE. 2381 2382 Systems with fully functional boot loaders (i.e. non-embedded) 2383 should leave this option set to 'N'. 2384 2385config CMDLINE 2386 string "Built-in kernel command string" 2387 depends on CMDLINE_BOOL 2388 default "" 2389 help 2390 Enter arguments here that should be compiled into the kernel 2391 image and used at boot time. If the boot loader provides a 2392 command line at boot time, it is appended to this string to 2393 form the full kernel command line, when the system boots. 2394 2395 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2396 change this behavior. 2397 2398 In most cases, the command line (whether built-in or provided 2399 by the boot loader) should specify the device for the root 2400 file system. 2401 2402config CMDLINE_OVERRIDE 2403 bool "Built-in command line overrides boot loader arguments" 2404 depends on CMDLINE_BOOL && CMDLINE != "" 2405 help 2406 Set this option to 'Y' to have the kernel ignore the boot loader 2407 command line, and use ONLY the built-in command line. 2408 2409 This is used to work around broken boot loaders. This should 2410 be set to 'N' under normal conditions. 2411 2412config MODIFY_LDT_SYSCALL 2413 bool "Enable the LDT (local descriptor table)" if EXPERT 2414 default y 2415 help 2416 Linux can allow user programs to install a per-process x86 2417 Local Descriptor Table (LDT) using the modify_ldt(2) system 2418 call. This is required to run 16-bit or segmented code such as 2419 DOSEMU or some Wine programs. It is also used by some very old 2420 threading libraries. 2421 2422 Enabling this feature adds a small amount of overhead to 2423 context switches and increases the low-level kernel attack 2424 surface. Disabling it removes the modify_ldt(2) system call. 2425 2426 Saying 'N' here may make sense for embedded or server kernels. 2427 2428source "kernel/livepatch/Kconfig" 2429 2430endmenu 2431 2432config ARCH_HAS_ADD_PAGES 2433 def_bool y 2434 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2435 2436config ARCH_ENABLE_MEMORY_HOTPLUG 2437 def_bool y 2438 depends on X86_64 || (X86_32 && HIGHMEM) 2439 2440config ARCH_ENABLE_MEMORY_HOTREMOVE 2441 def_bool y 2442 depends on MEMORY_HOTPLUG 2443 2444config USE_PERCPU_NUMA_NODE_ID 2445 def_bool y 2446 depends on NUMA 2447 2448config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2449 def_bool y 2450 depends on X86_64 || X86_PAE 2451 2452config ARCH_ENABLE_HUGEPAGE_MIGRATION 2453 def_bool y 2454 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2455 2456config ARCH_ENABLE_THP_MIGRATION 2457 def_bool y 2458 depends on X86_64 && TRANSPARENT_HUGEPAGE 2459 2460menu "Power management and ACPI options" 2461 2462config ARCH_HIBERNATION_HEADER 2463 def_bool y 2464 depends on HIBERNATION 2465 2466source "kernel/power/Kconfig" 2467 2468source "drivers/acpi/Kconfig" 2469 2470source "drivers/sfi/Kconfig" 2471 2472config X86_APM_BOOT 2473 def_bool y 2474 depends on APM 2475 2476menuconfig APM 2477 tristate "APM (Advanced Power Management) BIOS support" 2478 depends on X86_32 && PM_SLEEP 2479 help 2480 APM is a BIOS specification for saving power using several different 2481 techniques. This is mostly useful for battery powered laptops with 2482 APM compliant BIOSes. If you say Y here, the system time will be 2483 reset after a RESUME operation, the /proc/apm device will provide 2484 battery status information, and user-space programs will receive 2485 notification of APM "events" (e.g. battery status change). 2486 2487 If you select "Y" here, you can disable actual use of the APM 2488 BIOS by passing the "apm=off" option to the kernel at boot time. 2489 2490 Note that the APM support is almost completely disabled for 2491 machines with more than one CPU. 2492 2493 In order to use APM, you will need supporting software. For location 2494 and more information, read <file:Documentation/power/apm-acpi.rst> 2495 and the Battery Powered Linux mini-HOWTO, available from 2496 <http://www.tldp.org/docs.html#howto>. 2497 2498 This driver does not spin down disk drives (see the hdparm(8) 2499 manpage ("man 8 hdparm") for that), and it doesn't turn off 2500 VESA-compliant "green" monitors. 2501 2502 This driver does not support the TI 4000M TravelMate and the ACER 2503 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2504 desktop machines also don't have compliant BIOSes, and this driver 2505 may cause those machines to panic during the boot phase. 2506 2507 Generally, if you don't have a battery in your machine, there isn't 2508 much point in using this driver and you should say N. If you get 2509 random kernel OOPSes or reboots that don't seem to be related to 2510 anything, try disabling/enabling this option (or disabling/enabling 2511 APM in your BIOS). 2512 2513 Some other things you should try when experiencing seemingly random, 2514 "weird" problems: 2515 2516 1) make sure that you have enough swap space and that it is 2517 enabled. 2518 2) pass the "no-hlt" option to the kernel 2519 3) switch on floating point emulation in the kernel and pass 2520 the "no387" option to the kernel 2521 4) pass the "floppy=nodma" option to the kernel 2522 5) pass the "mem=4M" option to the kernel (thereby disabling 2523 all but the first 4 MB of RAM) 2524 6) make sure that the CPU is not over clocked. 2525 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2526 8) disable the cache from your BIOS settings 2527 9) install a fan for the video card or exchange video RAM 2528 10) install a better fan for the CPU 2529 11) exchange RAM chips 2530 12) exchange the motherboard. 2531 2532 To compile this driver as a module, choose M here: the 2533 module will be called apm. 2534 2535if APM 2536 2537config APM_IGNORE_USER_SUSPEND 2538 bool "Ignore USER SUSPEND" 2539 help 2540 This option will ignore USER SUSPEND requests. On machines with a 2541 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2542 series notebooks, it is necessary to say Y because of a BIOS bug. 2543 2544config APM_DO_ENABLE 2545 bool "Enable PM at boot time" 2546 help 2547 Enable APM features at boot time. From page 36 of the APM BIOS 2548 specification: "When disabled, the APM BIOS does not automatically 2549 power manage devices, enter the Standby State, enter the Suspend 2550 State, or take power saving steps in response to CPU Idle calls." 2551 This driver will make CPU Idle calls when Linux is idle (unless this 2552 feature is turned off -- see "Do CPU IDLE calls", below). This 2553 should always save battery power, but more complicated APM features 2554 will be dependent on your BIOS implementation. You may need to turn 2555 this option off if your computer hangs at boot time when using APM 2556 support, or if it beeps continuously instead of suspending. Turn 2557 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2558 T400CDT. This is off by default since most machines do fine without 2559 this feature. 2560 2561config APM_CPU_IDLE 2562 depends on CPU_IDLE 2563 bool "Make CPU Idle calls when idle" 2564 help 2565 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2566 On some machines, this can activate improved power savings, such as 2567 a slowed CPU clock rate, when the machine is idle. These idle calls 2568 are made after the idle loop has run for some length of time (e.g., 2569 333 mS). On some machines, this will cause a hang at boot time or 2570 whenever the CPU becomes idle. (On machines with more than one CPU, 2571 this option does nothing.) 2572 2573config APM_DISPLAY_BLANK 2574 bool "Enable console blanking using APM" 2575 help 2576 Enable console blanking using the APM. Some laptops can use this to 2577 turn off the LCD backlight when the screen blanker of the Linux 2578 virtual console blanks the screen. Note that this is only used by 2579 the virtual console screen blanker, and won't turn off the backlight 2580 when using the X Window system. This also doesn't have anything to 2581 do with your VESA-compliant power-saving monitor. Further, this 2582 option doesn't work for all laptops -- it might not turn off your 2583 backlight at all, or it might print a lot of errors to the console, 2584 especially if you are using gpm. 2585 2586config APM_ALLOW_INTS 2587 bool "Allow interrupts during APM BIOS calls" 2588 help 2589 Normally we disable external interrupts while we are making calls to 2590 the APM BIOS as a measure to lessen the effects of a badly behaving 2591 BIOS implementation. The BIOS should reenable interrupts if it 2592 needs to. Unfortunately, some BIOSes do not -- especially those in 2593 many of the newer IBM Thinkpads. If you experience hangs when you 2594 suspend, try setting this to Y. Otherwise, say N. 2595 2596endif # APM 2597 2598source "drivers/cpufreq/Kconfig" 2599 2600source "drivers/cpuidle/Kconfig" 2601 2602source "drivers/idle/Kconfig" 2603 2604endmenu 2605 2606 2607menu "Bus options (PCI etc.)" 2608 2609choice 2610 prompt "PCI access mode" 2611 depends on X86_32 && PCI 2612 default PCI_GOANY 2613 help 2614 On PCI systems, the BIOS can be used to detect the PCI devices and 2615 determine their configuration. However, some old PCI motherboards 2616 have BIOS bugs and may crash if this is done. Also, some embedded 2617 PCI-based systems don't have any BIOS at all. Linux can also try to 2618 detect the PCI hardware directly without using the BIOS. 2619 2620 With this option, you can specify how Linux should detect the 2621 PCI devices. If you choose "BIOS", the BIOS will be used, 2622 if you choose "Direct", the BIOS won't be used, and if you 2623 choose "MMConfig", then PCI Express MMCONFIG will be used. 2624 If you choose "Any", the kernel will try MMCONFIG, then the 2625 direct access method and falls back to the BIOS if that doesn't 2626 work. If unsure, go with the default, which is "Any". 2627 2628config PCI_GOBIOS 2629 bool "BIOS" 2630 2631config PCI_GOMMCONFIG 2632 bool "MMConfig" 2633 2634config PCI_GODIRECT 2635 bool "Direct" 2636 2637config PCI_GOOLPC 2638 bool "OLPC XO-1" 2639 depends on OLPC 2640 2641config PCI_GOANY 2642 bool "Any" 2643 2644endchoice 2645 2646config PCI_BIOS 2647 def_bool y 2648 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2649 2650# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2651config PCI_DIRECT 2652 def_bool y 2653 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2654 2655config PCI_MMCONFIG 2656 bool "Support mmconfig PCI config space access" if X86_64 2657 default y 2658 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2659 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2660 2661config PCI_OLPC 2662 def_bool y 2663 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2664 2665config PCI_XEN 2666 def_bool y 2667 depends on PCI && XEN 2668 select SWIOTLB_XEN 2669 2670config MMCONF_FAM10H 2671 def_bool y 2672 depends on X86_64 && PCI_MMCONFIG && ACPI 2673 2674config PCI_CNB20LE_QUIRK 2675 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2676 depends on PCI 2677 help 2678 Read the PCI windows out of the CNB20LE host bridge. This allows 2679 PCI hotplug to work on systems with the CNB20LE chipset which do 2680 not have ACPI. 2681 2682 There's no public spec for this chipset, and this functionality 2683 is known to be incomplete. 2684 2685 You should say N unless you know you need this. 2686 2687config ISA_BUS 2688 bool "ISA bus support on modern systems" if EXPERT 2689 help 2690 Expose ISA bus device drivers and options available for selection and 2691 configuration. Enable this option if your target machine has an ISA 2692 bus. ISA is an older system, displaced by PCI and newer bus 2693 architectures -- if your target machine is modern, it probably does 2694 not have an ISA bus. 2695 2696 If unsure, say N. 2697 2698# x86_64 have no ISA slots, but can have ISA-style DMA. 2699config ISA_DMA_API 2700 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2701 default y 2702 help 2703 Enables ISA-style DMA support for devices requiring such controllers. 2704 If unsure, say Y. 2705 2706if X86_32 2707 2708config ISA 2709 bool "ISA support" 2710 help 2711 Find out whether you have ISA slots on your motherboard. ISA is the 2712 name of a bus system, i.e. the way the CPU talks to the other stuff 2713 inside your box. Other bus systems are PCI, EISA, MicroChannel 2714 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2715 newer boards don't support it. If you have ISA, say Y, otherwise N. 2716 2717config SCx200 2718 tristate "NatSemi SCx200 support" 2719 help 2720 This provides basic support for National Semiconductor's 2721 (now AMD's) Geode processors. The driver probes for the 2722 PCI-IDs of several on-chip devices, so its a good dependency 2723 for other scx200_* drivers. 2724 2725 If compiled as a module, the driver is named scx200. 2726 2727config SCx200HR_TIMER 2728 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2729 depends on SCx200 2730 default y 2731 help 2732 This driver provides a clocksource built upon the on-chip 2733 27MHz high-resolution timer. Its also a workaround for 2734 NSC Geode SC-1100's buggy TSC, which loses time when the 2735 processor goes idle (as is done by the scheduler). The 2736 other workaround is idle=poll boot option. 2737 2738config OLPC 2739 bool "One Laptop Per Child support" 2740 depends on !X86_PAE 2741 select GPIOLIB 2742 select OF 2743 select OF_PROMTREE 2744 select IRQ_DOMAIN 2745 select OLPC_EC 2746 help 2747 Add support for detecting the unique features of the OLPC 2748 XO hardware. 2749 2750config OLPC_XO1_PM 2751 bool "OLPC XO-1 Power Management" 2752 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2753 help 2754 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2755 2756config OLPC_XO1_RTC 2757 bool "OLPC XO-1 Real Time Clock" 2758 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2759 help 2760 Add support for the XO-1 real time clock, which can be used as a 2761 programmable wakeup source. 2762 2763config OLPC_XO1_SCI 2764 bool "OLPC XO-1 SCI extras" 2765 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2766 depends on INPUT=y 2767 select POWER_SUPPLY 2768 help 2769 Add support for SCI-based features of the OLPC XO-1 laptop: 2770 - EC-driven system wakeups 2771 - Power button 2772 - Ebook switch 2773 - Lid switch 2774 - AC adapter status updates 2775 - Battery status updates 2776 2777config OLPC_XO15_SCI 2778 bool "OLPC XO-1.5 SCI extras" 2779 depends on OLPC && ACPI 2780 select POWER_SUPPLY 2781 help 2782 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2783 - EC-driven system wakeups 2784 - AC adapter status updates 2785 - Battery status updates 2786 2787config ALIX 2788 bool "PCEngines ALIX System Support (LED setup)" 2789 select GPIOLIB 2790 help 2791 This option enables system support for the PCEngines ALIX. 2792 At present this just sets up LEDs for GPIO control on 2793 ALIX2/3/6 boards. However, other system specific setup should 2794 get added here. 2795 2796 Note: You must still enable the drivers for GPIO and LED support 2797 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2798 2799 Note: You have to set alix.force=1 for boards with Award BIOS. 2800 2801config NET5501 2802 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2803 select GPIOLIB 2804 help 2805 This option enables system support for the Soekris Engineering net5501. 2806 2807config GEOS 2808 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2809 select GPIOLIB 2810 depends on DMI 2811 help 2812 This option enables system support for the Traverse Technologies GEOS. 2813 2814config TS5500 2815 bool "Technologic Systems TS-5500 platform support" 2816 depends on MELAN 2817 select CHECK_SIGNATURE 2818 select NEW_LEDS 2819 select LEDS_CLASS 2820 help 2821 This option enables system support for the Technologic Systems TS-5500. 2822 2823endif # X86_32 2824 2825config AMD_NB 2826 def_bool y 2827 depends on CPU_SUP_AMD && PCI 2828 2829config X86_SYSFB 2830 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2831 help 2832 Firmwares often provide initial graphics framebuffers so the BIOS, 2833 bootloader or kernel can show basic video-output during boot for 2834 user-guidance and debugging. Historically, x86 used the VESA BIOS 2835 Extensions and EFI-framebuffers for this, which are mostly limited 2836 to x86. 2837 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2838 framebuffers so the new generic system-framebuffer drivers can be 2839 used on x86. If the framebuffer is not compatible with the generic 2840 modes, it is advertised as fallback platform framebuffer so legacy 2841 drivers like efifb, vesafb and uvesafb can pick it up. 2842 If this option is not selected, all system framebuffers are always 2843 marked as fallback platform framebuffers as usual. 2844 2845 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2846 not be able to pick up generic system framebuffers if this option 2847 is selected. You are highly encouraged to enable simplefb as 2848 replacement if you select this option. simplefb can correctly deal 2849 with generic system framebuffers. But you should still keep vesafb 2850 and others enabled as fallback if a system framebuffer is 2851 incompatible with simplefb. 2852 2853 If unsure, say Y. 2854 2855endmenu 2856 2857 2858menu "Binary Emulations" 2859 2860config IA32_EMULATION 2861 bool "IA32 Emulation" 2862 depends on X86_64 2863 select ARCH_WANT_OLD_COMPAT_IPC 2864 select BINFMT_ELF 2865 select COMPAT_BINFMT_ELF 2866 select COMPAT_OLD_SIGACTION 2867 help 2868 Include code to run legacy 32-bit programs under a 2869 64-bit kernel. You should likely turn this on, unless you're 2870 100% sure that you don't have any 32-bit programs left. 2871 2872config IA32_AOUT 2873 tristate "IA32 a.out support" 2874 depends on IA32_EMULATION 2875 depends on BROKEN 2876 help 2877 Support old a.out binaries in the 32bit emulation. 2878 2879config X86_X32 2880 bool "x32 ABI for 64-bit mode" 2881 depends on X86_64 2882 help 2883 Include code to run binaries for the x32 native 32-bit ABI 2884 for 64-bit processors. An x32 process gets access to the 2885 full 64-bit register file and wide data path while leaving 2886 pointers at 32 bits for smaller memory footprint. 2887 2888 You will need a recent binutils (2.22 or later) with 2889 elf32_x86_64 support enabled to compile a kernel with this 2890 option set. 2891 2892config COMPAT_32 2893 def_bool y 2894 depends on IA32_EMULATION || X86_32 2895 select HAVE_UID16 2896 select OLD_SIGSUSPEND3 2897 2898config COMPAT 2899 def_bool y 2900 depends on IA32_EMULATION || X86_X32 2901 2902if COMPAT 2903config COMPAT_FOR_U64_ALIGNMENT 2904 def_bool y 2905 2906config SYSVIPC_COMPAT 2907 def_bool y 2908 depends on SYSVIPC 2909endif 2910 2911endmenu 2912 2913 2914config HAVE_ATOMIC_IOMAP 2915 def_bool y 2916 depends on X86_32 2917 2918source "drivers/firmware/Kconfig" 2919 2920source "arch/x86/kvm/Kconfig" 2921 2922source "arch/x86/Kconfig.assembler" 2923