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_ARGS if X86_64 175 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 176 select HAVE_EBPF_JIT 177 select HAVE_EFFICIENT_UNALIGNED_ACCESS 178 select HAVE_EISA 179 select HAVE_EXIT_THREAD 180 select HAVE_FAST_GUP 181 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 182 select HAVE_FTRACE_MCOUNT_RECORD 183 select HAVE_FUNCTION_GRAPH_TRACER 184 select HAVE_FUNCTION_TRACER 185 select HAVE_GCC_PLUGINS 186 select HAVE_HW_BREAKPOINT 187 select HAVE_IDE 188 select HAVE_IOREMAP_PROT 189 select HAVE_IRQ_TIME_ACCOUNTING 190 select HAVE_KERNEL_BZIP2 191 select HAVE_KERNEL_GZIP 192 select HAVE_KERNEL_LZ4 193 select HAVE_KERNEL_LZMA 194 select HAVE_KERNEL_LZO 195 select HAVE_KERNEL_XZ 196 select HAVE_KERNEL_ZSTD 197 select HAVE_KPROBES 198 select HAVE_KPROBES_ON_FTRACE 199 select HAVE_FUNCTION_ERROR_INJECTION 200 select HAVE_KRETPROBES 201 select HAVE_KVM 202 select HAVE_LIVEPATCH if X86_64 203 select HAVE_MIXED_BREAKPOINTS_REGS 204 select HAVE_MOD_ARCH_SPECIFIC 205 select HAVE_MOVE_PMD 206 select HAVE_MOVE_PUD 207 select HAVE_NMI 208 select HAVE_OPROFILE 209 select HAVE_OPTPROBES 210 select HAVE_PCSPKR_PLATFORM 211 select HAVE_PERF_EVENTS 212 select HAVE_PERF_EVENTS_NMI 213 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 214 select HAVE_PCI 215 select HAVE_PERF_REGS 216 select HAVE_PERF_USER_STACK_DUMP 217 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 218 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 219 select HAVE_REGS_AND_STACK_ACCESS_API 220 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 221 select HAVE_FUNCTION_ARG_ACCESS_API 222 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 223 select HAVE_STACK_VALIDATION if X86_64 224 select HAVE_STATIC_CALL 225 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 226 select HAVE_RSEQ 227 select HAVE_SYSCALL_TRACEPOINTS 228 select HAVE_UNSTABLE_SCHED_CLOCK 229 select HAVE_USER_RETURN_NOTIFIER 230 select HAVE_GENERIC_VDSO 231 select HOTPLUG_SMT if SMP 232 select IRQ_FORCED_THREADING 233 select NEED_SG_DMA_LENGTH 234 select PCI_DOMAINS if PCI 235 select PCI_LOCKLESS_CONFIG if PCI 236 select PERF_EVENTS 237 select RTC_LIB 238 select RTC_MC146818_LIB 239 select SPARSE_IRQ 240 select SRCU 241 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 242 select SYSCTL_EXCEPTION_TRACE 243 select THREAD_INFO_IN_TASK 244 select USER_STACKTRACE_SUPPORT 245 select VIRT_TO_BUS 246 select HAVE_ARCH_KCSAN if X86_64 247 select X86_FEATURE_NAMES if PROC_FS 248 select PROC_PID_ARCH_STATUS if PROC_FS 249 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 250 251config INSTRUCTION_DECODER 252 def_bool y 253 depends on KPROBES || PERF_EVENTS || UPROBES 254 255config OUTPUT_FORMAT 256 string 257 default "elf32-i386" if X86_32 258 default "elf64-x86-64" if X86_64 259 260config LOCKDEP_SUPPORT 261 def_bool y 262 263config STACKTRACE_SUPPORT 264 def_bool y 265 266config MMU 267 def_bool y 268 269config ARCH_MMAP_RND_BITS_MIN 270 default 28 if 64BIT 271 default 8 272 273config ARCH_MMAP_RND_BITS_MAX 274 default 32 if 64BIT 275 default 16 276 277config ARCH_MMAP_RND_COMPAT_BITS_MIN 278 default 8 279 280config ARCH_MMAP_RND_COMPAT_BITS_MAX 281 default 16 282 283config SBUS 284 bool 285 286config GENERIC_ISA_DMA 287 def_bool y 288 depends on ISA_DMA_API 289 290config GENERIC_BUG 291 def_bool y 292 depends on BUG 293 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 294 295config GENERIC_BUG_RELATIVE_POINTERS 296 bool 297 298config ARCH_MAY_HAVE_PC_FDC 299 def_bool y 300 depends on ISA_DMA_API 301 302config GENERIC_CALIBRATE_DELAY 303 def_bool y 304 305config ARCH_HAS_CPU_RELAX 306 def_bool y 307 308config ARCH_HAS_CACHE_LINE_SIZE 309 def_bool y 310 311config ARCH_HAS_FILTER_PGPROT 312 def_bool y 313 314config HAVE_SETUP_PER_CPU_AREA 315 def_bool y 316 317config NEED_PER_CPU_EMBED_FIRST_CHUNK 318 def_bool y 319 320config NEED_PER_CPU_PAGE_FIRST_CHUNK 321 def_bool y 322 323config ARCH_HIBERNATION_POSSIBLE 324 def_bool y 325 326config ARCH_SUSPEND_POSSIBLE 327 def_bool y 328 329config ARCH_WANT_GENERAL_HUGETLB 330 def_bool y 331 332config ZONE_DMA32 333 def_bool y if X86_64 334 335config AUDIT_ARCH 336 def_bool y if X86_64 337 338config KASAN_SHADOW_OFFSET 339 hex 340 depends on KASAN 341 default 0xdffffc0000000000 342 343config HAVE_INTEL_TXT 344 def_bool y 345 depends on INTEL_IOMMU && ACPI 346 347config X86_32_SMP 348 def_bool y 349 depends on X86_32 && SMP 350 351config X86_64_SMP 352 def_bool y 353 depends on X86_64 && SMP 354 355config X86_32_LAZY_GS 356 def_bool y 357 depends on X86_32 && !STACKPROTECTOR 358 359config ARCH_SUPPORTS_UPROBES 360 def_bool y 361 362config FIX_EARLYCON_MEM 363 def_bool y 364 365config DYNAMIC_PHYSICAL_MASK 366 bool 367 368config PGTABLE_LEVELS 369 int 370 default 5 if X86_5LEVEL 371 default 4 if X86_64 372 default 3 if X86_PAE 373 default 2 374 375config CC_HAS_SANE_STACKPROTECTOR 376 bool 377 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 378 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 379 help 380 We have to make sure stack protector is unconditionally disabled if 381 the compiler produces broken code. 382 383menu "Processor type and features" 384 385config ZONE_DMA 386 bool "DMA memory allocation support" if EXPERT 387 default y 388 help 389 DMA memory allocation support allows devices with less than 32-bit 390 addressing to allocate within the first 16MB of address space. 391 Disable if no such devices will be used. 392 393 If unsure, say Y. 394 395config SMP 396 bool "Symmetric multi-processing support" 397 help 398 This enables support for systems with more than one CPU. If you have 399 a system with only one CPU, say N. If you have a system with more 400 than one CPU, say Y. 401 402 If you say N here, the kernel will run on uni- and multiprocessor 403 machines, but will use only one CPU of a multiprocessor machine. If 404 you say Y here, the kernel will run on many, but not all, 405 uniprocessor machines. On a uniprocessor machine, the kernel 406 will run faster if you say N here. 407 408 Note that if you say Y here and choose architecture "586" or 409 "Pentium" under "Processor family", the kernel will not work on 486 410 architectures. Similarly, multiprocessor kernels for the "PPro" 411 architecture may not work on all Pentium based boards. 412 413 People using multiprocessor machines who say Y here should also say 414 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 415 Management" code will be disabled if you say Y here. 416 417 See also <file:Documentation/x86/i386/IO-APIC.rst>, 418 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 419 <http://www.tldp.org/docs.html#howto>. 420 421 If you don't know what to do here, say N. 422 423config X86_FEATURE_NAMES 424 bool "Processor feature human-readable names" if EMBEDDED 425 default y 426 help 427 This option compiles in a table of x86 feature bits and corresponding 428 names. This is required to support /proc/cpuinfo and a few kernel 429 messages. You can disable this to save space, at the expense of 430 making those few kernel messages show numeric feature bits instead. 431 432 If in doubt, say Y. 433 434config X86_X2APIC 435 bool "Support x2apic" 436 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 437 help 438 This enables x2apic support on CPUs that have this feature. 439 440 This allows 32-bit apic IDs (so it can support very large systems), 441 and accesses the local apic via MSRs not via mmio. 442 443 If you don't know what to do here, say N. 444 445config X86_MPPARSE 446 bool "Enable MPS table" if ACPI || SFI 447 default y 448 depends on X86_LOCAL_APIC 449 help 450 For old smp systems that do not have proper acpi support. Newer systems 451 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 452 453config GOLDFISH 454 def_bool y 455 depends on X86_GOLDFISH 456 457config RETPOLINE 458 bool "Avoid speculative indirect branches in kernel" 459 default y 460 help 461 Compile kernel with the retpoline compiler options to guard against 462 kernel-to-user data leaks by avoiding speculative indirect 463 branches. Requires a compiler with -mindirect-branch=thunk-extern 464 support for full protection. The kernel may run slower. 465 466config X86_CPU_RESCTRL 467 bool "x86 CPU resource control support" 468 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 469 select KERNFS 470 select PROC_CPU_RESCTRL if PROC_FS 471 help 472 Enable x86 CPU resource control support. 473 474 Provide support for the allocation and monitoring of system resources 475 usage by the CPU. 476 477 Intel calls this Intel Resource Director Technology 478 (Intel(R) RDT). More information about RDT can be found in the 479 Intel x86 Architecture Software Developer Manual. 480 481 AMD calls this AMD Platform Quality of Service (AMD QoS). 482 More information about AMD QoS can be found in the AMD64 Technology 483 Platform Quality of Service Extensions manual. 484 485 Say N if unsure. 486 487if X86_32 488config X86_BIGSMP 489 bool "Support for big SMP systems with more than 8 CPUs" 490 depends on SMP 491 help 492 This option is needed for the systems that have more than 8 CPUs. 493 494config X86_EXTENDED_PLATFORM 495 bool "Support for extended (non-PC) x86 platforms" 496 default y 497 help 498 If you disable this option then the kernel will only support 499 standard PC platforms. (which covers the vast majority of 500 systems out there.) 501 502 If you enable this option then you'll be able to select support 503 for the following (non-PC) 32 bit x86 platforms: 504 Goldfish (Android emulator) 505 AMD Elan 506 RDC R-321x SoC 507 SGI 320/540 (Visual Workstation) 508 STA2X11-based (e.g. Northville) 509 Moorestown MID devices 510 511 If you have one of these systems, or if you want to build a 512 generic distribution kernel, say Y here - otherwise say N. 513endif 514 515if X86_64 516config X86_EXTENDED_PLATFORM 517 bool "Support for extended (non-PC) x86 platforms" 518 default y 519 help 520 If you disable this option then the kernel will only support 521 standard PC platforms. (which covers the vast majority of 522 systems out there.) 523 524 If you enable this option then you'll be able to select support 525 for the following (non-PC) 64 bit x86 platforms: 526 Numascale NumaChip 527 ScaleMP vSMP 528 SGI Ultraviolet 529 530 If you have one of these systems, or if you want to build a 531 generic distribution kernel, say Y here - otherwise say N. 532endif 533# This is an alphabetically sorted list of 64 bit extended platforms 534# Please maintain the alphabetic order if and when there are additions 535config X86_NUMACHIP 536 bool "Numascale NumaChip" 537 depends on X86_64 538 depends on X86_EXTENDED_PLATFORM 539 depends on NUMA 540 depends on SMP 541 depends on X86_X2APIC 542 depends on PCI_MMCONFIG 543 help 544 Adds support for Numascale NumaChip large-SMP systems. Needed to 545 enable more than ~168 cores. 546 If you don't have one of these, you should say N here. 547 548config X86_VSMP 549 bool "ScaleMP vSMP" 550 select HYPERVISOR_GUEST 551 select PARAVIRT 552 depends on X86_64 && PCI 553 depends on X86_EXTENDED_PLATFORM 554 depends on SMP 555 help 556 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 557 supposed to run on these EM64T-based machines. Only choose this option 558 if you have one of these machines. 559 560config X86_UV 561 bool "SGI Ultraviolet" 562 depends on X86_64 563 depends on X86_EXTENDED_PLATFORM 564 depends on NUMA 565 depends on EFI 566 depends on X86_X2APIC 567 depends on PCI 568 help 569 This option is needed in order to support SGI Ultraviolet systems. 570 If you don't have one of these, you should say N here. 571 572# Following is an alphabetically sorted list of 32 bit extended platforms 573# Please maintain the alphabetic order if and when there are additions 574 575config X86_GOLDFISH 576 bool "Goldfish (Virtual Platform)" 577 depends on X86_EXTENDED_PLATFORM 578 help 579 Enable support for the Goldfish virtual platform used primarily 580 for Android development. Unless you are building for the Android 581 Goldfish emulator say N here. 582 583config X86_INTEL_CE 584 bool "CE4100 TV platform" 585 depends on PCI 586 depends on PCI_GODIRECT 587 depends on X86_IO_APIC 588 depends on X86_32 589 depends on X86_EXTENDED_PLATFORM 590 select X86_REBOOTFIXUPS 591 select OF 592 select OF_EARLY_FLATTREE 593 help 594 Select for the Intel CE media processor (CE4100) SOC. 595 This option compiles in support for the CE4100 SOC for settop 596 boxes and media devices. 597 598config X86_INTEL_MID 599 bool "Intel MID platform support" 600 depends on X86_EXTENDED_PLATFORM 601 depends on X86_PLATFORM_DEVICES 602 depends on PCI 603 depends on X86_64 || (PCI_GOANY && X86_32) 604 depends on X86_IO_APIC 605 select SFI 606 select I2C 607 select DW_APB_TIMER 608 select APB_TIMER 609 select INTEL_SCU_PCI 610 select MFD_INTEL_MSIC 611 help 612 Select to build a kernel capable of supporting Intel MID (Mobile 613 Internet Device) platform systems which do not have the PCI legacy 614 interfaces. If you are building for a PC class system say N here. 615 616 Intel MID platforms are based on an Intel processor and chipset which 617 consume less power than most of the x86 derivatives. 618 619config X86_INTEL_QUARK 620 bool "Intel Quark platform support" 621 depends on X86_32 622 depends on X86_EXTENDED_PLATFORM 623 depends on X86_PLATFORM_DEVICES 624 depends on X86_TSC 625 depends on PCI 626 depends on PCI_GOANY 627 depends on X86_IO_APIC 628 select IOSF_MBI 629 select INTEL_IMR 630 select COMMON_CLK 631 help 632 Select to include support for Quark X1000 SoC. 633 Say Y here if you have a Quark based system such as the Arduino 634 compatible Intel Galileo. 635 636config X86_INTEL_LPSS 637 bool "Intel Low Power Subsystem Support" 638 depends on X86 && ACPI && PCI 639 select COMMON_CLK 640 select PINCTRL 641 select IOSF_MBI 642 help 643 Select to build support for Intel Low Power Subsystem such as 644 found on Intel Lynxpoint PCH. Selecting this option enables 645 things like clock tree (common clock framework) and pincontrol 646 which are needed by the LPSS peripheral drivers. 647 648config X86_AMD_PLATFORM_DEVICE 649 bool "AMD ACPI2Platform devices support" 650 depends on ACPI 651 select COMMON_CLK 652 select PINCTRL 653 help 654 Select to interpret AMD specific ACPI device to platform device 655 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 656 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 657 implemented under PINCTRL subsystem. 658 659config IOSF_MBI 660 tristate "Intel SoC IOSF Sideband support for SoC platforms" 661 depends on PCI 662 help 663 This option enables sideband register access support for Intel SoC 664 platforms. On these platforms the IOSF sideband is used in lieu of 665 MSR's for some register accesses, mostly but not limited to thermal 666 and power. Drivers may query the availability of this device to 667 determine if they need the sideband in order to work on these 668 platforms. The sideband is available on the following SoC products. 669 This list is not meant to be exclusive. 670 - BayTrail 671 - Braswell 672 - Quark 673 674 You should say Y if you are running a kernel on one of these SoC's. 675 676config IOSF_MBI_DEBUG 677 bool "Enable IOSF sideband access through debugfs" 678 depends on IOSF_MBI && DEBUG_FS 679 help 680 Select this option to expose the IOSF sideband access registers (MCR, 681 MDR, MCRX) through debugfs to write and read register information from 682 different units on the SoC. This is most useful for obtaining device 683 state information for debug and analysis. As this is a general access 684 mechanism, users of this option would have specific knowledge of the 685 device they want to access. 686 687 If you don't require the option or are in doubt, say N. 688 689config X86_RDC321X 690 bool "RDC R-321x SoC" 691 depends on X86_32 692 depends on X86_EXTENDED_PLATFORM 693 select M486 694 select X86_REBOOTFIXUPS 695 help 696 This option is needed for RDC R-321x system-on-chip, also known 697 as R-8610-(G). 698 If you don't have one of these chips, you should say N here. 699 700config X86_32_NON_STANDARD 701 bool "Support non-standard 32-bit SMP architectures" 702 depends on X86_32 && SMP 703 depends on X86_EXTENDED_PLATFORM 704 help 705 This option compiles in the bigsmp and STA2X11 default 706 subarchitectures. It is intended for a generic binary 707 kernel. If you select them all, kernel will probe it one by 708 one and will fallback to default. 709 710# Alphabetically sorted list of Non standard 32 bit platforms 711 712config X86_SUPPORTS_MEMORY_FAILURE 713 def_bool y 714 # MCE code calls memory_failure(): 715 depends on X86_MCE 716 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 717 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 718 depends on X86_64 || !SPARSEMEM 719 select ARCH_SUPPORTS_MEMORY_FAILURE 720 721config STA2X11 722 bool "STA2X11 Companion Chip Support" 723 depends on X86_32_NON_STANDARD && PCI 724 select SWIOTLB 725 select MFD_STA2X11 726 select GPIOLIB 727 help 728 This adds support for boards based on the STA2X11 IO-Hub, 729 a.k.a. "ConneXt". The chip is used in place of the standard 730 PC chipset, so all "standard" peripherals are missing. If this 731 option is selected the kernel will still be able to boot on 732 standard PC machines. 733 734config X86_32_IRIS 735 tristate "Eurobraille/Iris poweroff module" 736 depends on X86_32 737 help 738 The Iris machines from EuroBraille do not have APM or ACPI support 739 to shut themselves down properly. A special I/O sequence is 740 needed to do so, which is what this module does at 741 kernel shutdown. 742 743 This is only for Iris machines from EuroBraille. 744 745 If unused, say N. 746 747config SCHED_OMIT_FRAME_POINTER 748 def_bool y 749 prompt "Single-depth WCHAN output" 750 depends on X86 751 help 752 Calculate simpler /proc/<PID>/wchan values. If this option 753 is disabled then wchan values will recurse back to the 754 caller function. This provides more accurate wchan values, 755 at the expense of slightly more scheduling overhead. 756 757 If in doubt, say "Y". 758 759menuconfig HYPERVISOR_GUEST 760 bool "Linux guest support" 761 help 762 Say Y here to enable options for running Linux under various hyper- 763 visors. This option enables basic hypervisor detection and platform 764 setup. 765 766 If you say N, all options in this submenu will be skipped and 767 disabled, and Linux guest support won't be built in. 768 769if HYPERVISOR_GUEST 770 771config PARAVIRT 772 bool "Enable paravirtualization code" 773 help 774 This changes the kernel so it can modify itself when it is run 775 under a hypervisor, potentially improving performance significantly 776 over full virtualization. However, when run without a hypervisor 777 the kernel is theoretically slower and slightly larger. 778 779config PARAVIRT_XXL 780 bool 781 782config PARAVIRT_DEBUG 783 bool "paravirt-ops debugging" 784 depends on PARAVIRT && DEBUG_KERNEL 785 help 786 Enable to debug paravirt_ops internals. Specifically, BUG if 787 a paravirt_op is missing when it is called. 788 789config PARAVIRT_SPINLOCKS 790 bool "Paravirtualization layer for spinlocks" 791 depends on PARAVIRT && SMP 792 help 793 Paravirtualized spinlocks allow a pvops backend to replace the 794 spinlock implementation with something virtualization-friendly 795 (for example, block the virtual CPU rather than spinning). 796 797 It has a minimal impact on native kernels and gives a nice performance 798 benefit on paravirtualized KVM / Xen kernels. 799 800 If you are unsure how to answer this question, answer Y. 801 802config X86_HV_CALLBACK_VECTOR 803 def_bool n 804 805source "arch/x86/xen/Kconfig" 806 807config KVM_GUEST 808 bool "KVM Guest support (including kvmclock)" 809 depends on PARAVIRT 810 select PARAVIRT_CLOCK 811 select ARCH_CPUIDLE_HALTPOLL 812 select X86_HV_CALLBACK_VECTOR 813 default y 814 help 815 This option enables various optimizations for running under the KVM 816 hypervisor. It includes a paravirtualized clock, so that instead 817 of relying on a PIT (or probably other) emulation by the 818 underlying device model, the host provides the guest with 819 timing infrastructure such as time of day, and system time 820 821config ARCH_CPUIDLE_HALTPOLL 822 def_bool n 823 prompt "Disable host haltpoll when loading haltpoll driver" 824 help 825 If virtualized under KVM, disable host haltpoll. 826 827config PVH 828 bool "Support for running PVH guests" 829 help 830 This option enables the PVH entry point for guest virtual machines 831 as specified in the x86/HVM direct boot ABI. 832 833config PARAVIRT_TIME_ACCOUNTING 834 bool "Paravirtual steal time accounting" 835 depends on PARAVIRT 836 help 837 Select this option to enable fine granularity task steal time 838 accounting. Time spent executing other tasks in parallel with 839 the current vCPU is discounted from the vCPU power. To account for 840 that, there can be a small performance impact. 841 842 If in doubt, say N here. 843 844config PARAVIRT_CLOCK 845 bool 846 847config JAILHOUSE_GUEST 848 bool "Jailhouse non-root cell support" 849 depends on X86_64 && PCI 850 select X86_PM_TIMER 851 help 852 This option allows to run Linux as guest in a Jailhouse non-root 853 cell. You can leave this option disabled if you only want to start 854 Jailhouse and run Linux afterwards in the root cell. 855 856config ACRN_GUEST 857 bool "ACRN Guest support" 858 depends on X86_64 859 select X86_HV_CALLBACK_VECTOR 860 help 861 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 862 a flexible, lightweight reference open-source hypervisor, built with 863 real-time and safety-criticality in mind. It is built for embedded 864 IOT with small footprint and real-time features. More details can be 865 found in https://projectacrn.org/. 866 867endif #HYPERVISOR_GUEST 868 869source "arch/x86/Kconfig.cpu" 870 871config HPET_TIMER 872 def_bool X86_64 873 prompt "HPET Timer Support" if X86_32 874 help 875 Use the IA-PC HPET (High Precision Event Timer) to manage 876 time in preference to the PIT and RTC, if a HPET is 877 present. 878 HPET is the next generation timer replacing legacy 8254s. 879 The HPET provides a stable time base on SMP 880 systems, unlike the TSC, but it is more expensive to access, 881 as it is off-chip. The interface used is documented 882 in the HPET spec, revision 1. 883 884 You can safely choose Y here. However, HPET will only be 885 activated if the platform and the BIOS support this feature. 886 Otherwise the 8254 will be used for timing services. 887 888 Choose N to continue using the legacy 8254 timer. 889 890config HPET_EMULATE_RTC 891 def_bool y 892 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 893 894config APB_TIMER 895 def_bool y if X86_INTEL_MID 896 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 897 select DW_APB_TIMER 898 depends on X86_INTEL_MID && SFI 899 help 900 APB timer is the replacement for 8254, HPET on X86 MID platforms. 901 The APBT provides a stable time base on SMP 902 systems, unlike the TSC, but it is more expensive to access, 903 as it is off-chip. APB timers are always running regardless of CPU 904 C states, they are used as per CPU clockevent device when possible. 905 906# Mark as expert because too many people got it wrong. 907# The code disables itself when not needed. 908config DMI 909 default y 910 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 911 bool "Enable DMI scanning" if EXPERT 912 help 913 Enabled scanning of DMI to identify machine quirks. Say Y 914 here unless you have verified that your setup is not 915 affected by entries in the DMI blacklist. Required by PNP 916 BIOS code. 917 918config GART_IOMMU 919 bool "Old AMD GART IOMMU support" 920 select DMA_OPS 921 select IOMMU_HELPER 922 select SWIOTLB 923 depends on X86_64 && PCI && AMD_NB 924 help 925 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 926 GART based hardware IOMMUs. 927 928 The GART supports full DMA access for devices with 32-bit access 929 limitations, on systems with more than 3 GB. This is usually needed 930 for USB, sound, many IDE/SATA chipsets and some other devices. 931 932 Newer systems typically have a modern AMD IOMMU, supported via 933 the CONFIG_AMD_IOMMU=y config option. 934 935 In normal configurations this driver is only active when needed: 936 there's more than 3 GB of memory and the system contains a 937 32-bit limited device. 938 939 If unsure, say Y. 940 941config MAXSMP 942 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 943 depends on X86_64 && SMP && DEBUG_KERNEL 944 select CPUMASK_OFFSTACK 945 help 946 Enable maximum number of CPUS and NUMA Nodes for this architecture. 947 If unsure, say N. 948 949# 950# The maximum number of CPUs supported: 951# 952# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 953# and which can be configured interactively in the 954# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 955# 956# The ranges are different on 32-bit and 64-bit kernels, depending on 957# hardware capabilities and scalability features of the kernel. 958# 959# ( If MAXSMP is enabled we just use the highest possible value and disable 960# interactive configuration. ) 961# 962 963config NR_CPUS_RANGE_BEGIN 964 int 965 default NR_CPUS_RANGE_END if MAXSMP 966 default 1 if !SMP 967 default 2 968 969config NR_CPUS_RANGE_END 970 int 971 depends on X86_32 972 default 64 if SMP && X86_BIGSMP 973 default 8 if SMP && !X86_BIGSMP 974 default 1 if !SMP 975 976config NR_CPUS_RANGE_END 977 int 978 depends on X86_64 979 default 8192 if SMP && CPUMASK_OFFSTACK 980 default 512 if SMP && !CPUMASK_OFFSTACK 981 default 1 if !SMP 982 983config NR_CPUS_DEFAULT 984 int 985 depends on X86_32 986 default 32 if X86_BIGSMP 987 default 8 if SMP 988 default 1 if !SMP 989 990config NR_CPUS_DEFAULT 991 int 992 depends on X86_64 993 default 8192 if MAXSMP 994 default 64 if SMP 995 default 1 if !SMP 996 997config NR_CPUS 998 int "Maximum number of CPUs" if SMP && !MAXSMP 999 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1000 default NR_CPUS_DEFAULT 1001 help 1002 This allows you to specify the maximum number of CPUs which this 1003 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1004 supported value is 8192, otherwise the maximum value is 512. The 1005 minimum value which makes sense is 2. 1006 1007 This is purely to save memory: each supported CPU adds about 8KB 1008 to the kernel image. 1009 1010config SCHED_SMT 1011 def_bool y if SMP 1012 1013config SCHED_MC 1014 def_bool y 1015 prompt "Multi-core scheduler support" 1016 depends on SMP 1017 help 1018 Multi-core scheduler support improves the CPU scheduler's decision 1019 making when dealing with multi-core CPU chips at a cost of slightly 1020 increased overhead in some places. If unsure say N here. 1021 1022config SCHED_MC_PRIO 1023 bool "CPU core priorities scheduler support" 1024 depends on SCHED_MC && CPU_SUP_INTEL 1025 select X86_INTEL_PSTATE 1026 select CPU_FREQ 1027 default y 1028 help 1029 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1030 core ordering determined at manufacturing time, which allows 1031 certain cores to reach higher turbo frequencies (when running 1032 single threaded workloads) than others. 1033 1034 Enabling this kernel feature teaches the scheduler about 1035 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1036 scheduler's CPU selection logic accordingly, so that higher 1037 overall system performance can be achieved. 1038 1039 This feature will have no effect on CPUs without this feature. 1040 1041 If unsure say Y here. 1042 1043config UP_LATE_INIT 1044 def_bool y 1045 depends on !SMP && X86_LOCAL_APIC 1046 1047config X86_UP_APIC 1048 bool "Local APIC support on uniprocessors" if !PCI_MSI 1049 default PCI_MSI 1050 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1051 help 1052 A local APIC (Advanced Programmable Interrupt Controller) is an 1053 integrated interrupt controller in the CPU. If you have a single-CPU 1054 system which has a processor with a local APIC, you can say Y here to 1055 enable and use it. If you say Y here even though your machine doesn't 1056 have a local APIC, then the kernel will still run with no slowdown at 1057 all. The local APIC supports CPU-generated self-interrupts (timer, 1058 performance counters), and the NMI watchdog which detects hard 1059 lockups. 1060 1061config X86_UP_IOAPIC 1062 bool "IO-APIC support on uniprocessors" 1063 depends on X86_UP_APIC 1064 help 1065 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1066 SMP-capable replacement for PC-style interrupt controllers. Most 1067 SMP systems and many recent uniprocessor systems have one. 1068 1069 If you have a single-CPU system with an IO-APIC, you can say Y here 1070 to use it. If you say Y here even though your machine doesn't have 1071 an IO-APIC, then the kernel will still run with no slowdown at all. 1072 1073config X86_LOCAL_APIC 1074 def_bool y 1075 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1076 select IRQ_DOMAIN_HIERARCHY 1077 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1078 1079config X86_IO_APIC 1080 def_bool y 1081 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1082 1083config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1084 bool "Reroute for broken boot IRQs" 1085 depends on X86_IO_APIC 1086 help 1087 This option enables a workaround that fixes a source of 1088 spurious interrupts. This is recommended when threaded 1089 interrupt handling is used on systems where the generation of 1090 superfluous "boot interrupts" cannot be disabled. 1091 1092 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1093 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1094 kernel does during interrupt handling). On chipsets where this 1095 boot IRQ generation cannot be disabled, this workaround keeps 1096 the original IRQ line masked so that only the equivalent "boot 1097 IRQ" is delivered to the CPUs. The workaround also tells the 1098 kernel to set up the IRQ handler on the boot IRQ line. In this 1099 way only one interrupt is delivered to the kernel. Otherwise 1100 the spurious second interrupt may cause the kernel to bring 1101 down (vital) interrupt lines. 1102 1103 Only affects "broken" chipsets. Interrupt sharing may be 1104 increased on these systems. 1105 1106config X86_MCE 1107 bool "Machine Check / overheating reporting" 1108 select GENERIC_ALLOCATOR 1109 default y 1110 help 1111 Machine Check support allows the processor to notify the 1112 kernel if it detects a problem (e.g. overheating, data corruption). 1113 The action the kernel takes depends on the severity of the problem, 1114 ranging from warning messages to halting the machine. 1115 1116config X86_MCELOG_LEGACY 1117 bool "Support for deprecated /dev/mcelog character device" 1118 depends on X86_MCE 1119 help 1120 Enable support for /dev/mcelog which is needed by the old mcelog 1121 userspace logging daemon. Consider switching to the new generation 1122 rasdaemon solution. 1123 1124config X86_MCE_INTEL 1125 def_bool y 1126 prompt "Intel MCE features" 1127 depends on X86_MCE && X86_LOCAL_APIC 1128 help 1129 Additional support for intel specific MCE features such as 1130 the thermal monitor. 1131 1132config X86_MCE_AMD 1133 def_bool y 1134 prompt "AMD MCE features" 1135 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1136 help 1137 Additional support for AMD specific MCE features such as 1138 the DRAM Error Threshold. 1139 1140config X86_ANCIENT_MCE 1141 bool "Support for old Pentium 5 / WinChip machine checks" 1142 depends on X86_32 && X86_MCE 1143 help 1144 Include support for machine check handling on old Pentium 5 or WinChip 1145 systems. These typically need to be enabled explicitly on the command 1146 line. 1147 1148config X86_MCE_THRESHOLD 1149 depends on X86_MCE_AMD || X86_MCE_INTEL 1150 def_bool y 1151 1152config X86_MCE_INJECT 1153 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1154 tristate "Machine check injector support" 1155 help 1156 Provide support for injecting machine checks for testing purposes. 1157 If you don't know what a machine check is and you don't do kernel 1158 QA it is safe to say n. 1159 1160config X86_THERMAL_VECTOR 1161 def_bool y 1162 depends on X86_MCE_INTEL 1163 1164source "arch/x86/events/Kconfig" 1165 1166config X86_LEGACY_VM86 1167 bool "Legacy VM86 support" 1168 depends on X86_32 1169 help 1170 This option allows user programs to put the CPU into V8086 1171 mode, which is an 80286-era approximation of 16-bit real mode. 1172 1173 Some very old versions of X and/or vbetool require this option 1174 for user mode setting. Similarly, DOSEMU will use it if 1175 available to accelerate real mode DOS programs. However, any 1176 recent version of DOSEMU, X, or vbetool should be fully 1177 functional even without kernel VM86 support, as they will all 1178 fall back to software emulation. Nevertheless, if you are using 1179 a 16-bit DOS program where 16-bit performance matters, vm86 1180 mode might be faster than emulation and you might want to 1181 enable this option. 1182 1183 Note that any app that works on a 64-bit kernel is unlikely to 1184 need this option, as 64-bit kernels don't, and can't, support 1185 V8086 mode. This option is also unrelated to 16-bit protected 1186 mode and is not needed to run most 16-bit programs under Wine. 1187 1188 Enabling this option increases the complexity of the kernel 1189 and slows down exception handling a tiny bit. 1190 1191 If unsure, say N here. 1192 1193config VM86 1194 bool 1195 default X86_LEGACY_VM86 1196 1197config X86_16BIT 1198 bool "Enable support for 16-bit segments" if EXPERT 1199 default y 1200 depends on MODIFY_LDT_SYSCALL 1201 help 1202 This option is required by programs like Wine to run 16-bit 1203 protected mode legacy code on x86 processors. Disabling 1204 this option saves about 300 bytes on i386, or around 6K text 1205 plus 16K runtime memory on x86-64, 1206 1207config X86_ESPFIX32 1208 def_bool y 1209 depends on X86_16BIT && X86_32 1210 1211config X86_ESPFIX64 1212 def_bool y 1213 depends on X86_16BIT && X86_64 1214 1215config X86_VSYSCALL_EMULATION 1216 bool "Enable vsyscall emulation" if EXPERT 1217 default y 1218 depends on X86_64 1219 help 1220 This enables emulation of the legacy vsyscall page. Disabling 1221 it is roughly equivalent to booting with vsyscall=none, except 1222 that it will also disable the helpful warning if a program 1223 tries to use a vsyscall. With this option set to N, offending 1224 programs will just segfault, citing addresses of the form 1225 0xffffffffff600?00. 1226 1227 This option is required by many programs built before 2013, and 1228 care should be used even with newer programs if set to N. 1229 1230 Disabling this option saves about 7K of kernel size and 1231 possibly 4K of additional runtime pagetable memory. 1232 1233config X86_IOPL_IOPERM 1234 bool "IOPERM and IOPL Emulation" 1235 default y 1236 help 1237 This enables the ioperm() and iopl() syscalls which are necessary 1238 for legacy applications. 1239 1240 Legacy IOPL support is an overbroad mechanism which allows user 1241 space aside of accessing all 65536 I/O ports also to disable 1242 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1243 capabilities and permission from potentially active security 1244 modules. 1245 1246 The emulation restricts the functionality of the syscall to 1247 only allowing the full range I/O port access, but prevents the 1248 ability to disable interrupts from user space which would be 1249 granted if the hardware IOPL mechanism would be used. 1250 1251config TOSHIBA 1252 tristate "Toshiba Laptop support" 1253 depends on X86_32 1254 help 1255 This adds a driver to safely access the System Management Mode of 1256 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1257 not work on models with a Phoenix BIOS. The System Management Mode 1258 is used to set the BIOS and power saving options on Toshiba portables. 1259 1260 For information on utilities to make use of this driver see the 1261 Toshiba Linux utilities web site at: 1262 <http://www.buzzard.org.uk/toshiba/>. 1263 1264 Say Y if you intend to run this kernel on a Toshiba portable. 1265 Say N otherwise. 1266 1267config I8K 1268 tristate "Dell i8k legacy laptop support" 1269 select HWMON 1270 select SENSORS_DELL_SMM 1271 help 1272 This option enables legacy /proc/i8k userspace interface in hwmon 1273 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1274 temperature and allows controlling fan speeds of Dell laptops via 1275 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1276 it reports also power and hotkey status. For fan speed control is 1277 needed userspace package i8kutils. 1278 1279 Say Y if you intend to run this kernel on old Dell laptops or want to 1280 use userspace package i8kutils. 1281 Say N otherwise. 1282 1283config X86_REBOOTFIXUPS 1284 bool "Enable X86 board specific fixups for reboot" 1285 depends on X86_32 1286 help 1287 This enables chipset and/or board specific fixups to be done 1288 in order to get reboot to work correctly. This is only needed on 1289 some combinations of hardware and BIOS. The symptom, for which 1290 this config is intended, is when reboot ends with a stalled/hung 1291 system. 1292 1293 Currently, the only fixup is for the Geode machines using 1294 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1295 1296 Say Y if you want to enable the fixup. Currently, it's safe to 1297 enable this option even if you don't need it. 1298 Say N otherwise. 1299 1300config MICROCODE 1301 bool "CPU microcode loading support" 1302 default y 1303 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1304 help 1305 If you say Y here, you will be able to update the microcode on 1306 Intel and AMD processors. The Intel support is for the IA32 family, 1307 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1308 AMD support is for families 0x10 and later. You will obviously need 1309 the actual microcode binary data itself which is not shipped with 1310 the Linux kernel. 1311 1312 The preferred method to load microcode from a detached initrd is described 1313 in Documentation/x86/microcode.rst. For that you need to enable 1314 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1315 initrd for microcode blobs. 1316 1317 In addition, you can build the microcode into the kernel. For that you 1318 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1319 config option. 1320 1321config MICROCODE_INTEL 1322 bool "Intel microcode loading support" 1323 depends on MICROCODE 1324 default MICROCODE 1325 help 1326 This options enables microcode patch loading support for Intel 1327 processors. 1328 1329 For the current Intel microcode data package go to 1330 <https://downloadcenter.intel.com> and search for 1331 'Linux Processor Microcode Data File'. 1332 1333config MICROCODE_AMD 1334 bool "AMD microcode loading support" 1335 depends on MICROCODE 1336 help 1337 If you select this option, microcode patch loading support for AMD 1338 processors will be enabled. 1339 1340config MICROCODE_OLD_INTERFACE 1341 bool "Ancient loading interface (DEPRECATED)" 1342 default n 1343 depends on MICROCODE 1344 help 1345 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1346 which was used by userspace tools like iucode_tool and microcode.ctl. 1347 It is inadequate because it runs too late to be able to properly 1348 load microcode on a machine and it needs special tools. Instead, you 1349 should've switched to the early loading method with the initrd or 1350 builtin microcode by now: Documentation/x86/microcode.rst 1351 1352config X86_MSR 1353 tristate "/dev/cpu/*/msr - Model-specific register support" 1354 help 1355 This device gives privileged processes access to the x86 1356 Model-Specific Registers (MSRs). It is a character device with 1357 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1358 MSR accesses are directed to a specific CPU on multi-processor 1359 systems. 1360 1361config X86_CPUID 1362 tristate "/dev/cpu/*/cpuid - CPU information support" 1363 help 1364 This device gives processes access to the x86 CPUID instruction to 1365 be executed on a specific processor. It is a character device 1366 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1367 /dev/cpu/31/cpuid. 1368 1369choice 1370 prompt "High Memory Support" 1371 default HIGHMEM4G 1372 depends on X86_32 1373 1374config NOHIGHMEM 1375 bool "off" 1376 help 1377 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1378 However, the address space of 32-bit x86 processors is only 4 1379 Gigabytes large. That means that, if you have a large amount of 1380 physical memory, not all of it can be "permanently mapped" by the 1381 kernel. The physical memory that's not permanently mapped is called 1382 "high memory". 1383 1384 If you are compiling a kernel which will never run on a machine with 1385 more than 1 Gigabyte total physical RAM, answer "off" here (default 1386 choice and suitable for most users). This will result in a "3GB/1GB" 1387 split: 3GB are mapped so that each process sees a 3GB virtual memory 1388 space and the remaining part of the 4GB virtual memory space is used 1389 by the kernel to permanently map as much physical memory as 1390 possible. 1391 1392 If the machine has between 1 and 4 Gigabytes physical RAM, then 1393 answer "4GB" here. 1394 1395 If more than 4 Gigabytes is used then answer "64GB" here. This 1396 selection turns Intel PAE (Physical Address Extension) mode on. 1397 PAE implements 3-level paging on IA32 processors. PAE is fully 1398 supported by Linux, PAE mode is implemented on all recent Intel 1399 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1400 then the kernel will not boot on CPUs that don't support PAE! 1401 1402 The actual amount of total physical memory will either be 1403 auto detected or can be forced by using a kernel command line option 1404 such as "mem=256M". (Try "man bootparam" or see the documentation of 1405 your boot loader (lilo or loadlin) about how to pass options to the 1406 kernel at boot time.) 1407 1408 If unsure, say "off". 1409 1410config HIGHMEM4G 1411 bool "4GB" 1412 help 1413 Select this if you have a 32-bit processor and between 1 and 4 1414 gigabytes of physical RAM. 1415 1416config HIGHMEM64G 1417 bool "64GB" 1418 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1419 select X86_PAE 1420 help 1421 Select this if you have a 32-bit processor and more than 4 1422 gigabytes of physical RAM. 1423 1424endchoice 1425 1426choice 1427 prompt "Memory split" if EXPERT 1428 default VMSPLIT_3G 1429 depends on X86_32 1430 help 1431 Select the desired split between kernel and user memory. 1432 1433 If the address range available to the kernel is less than the 1434 physical memory installed, the remaining memory will be available 1435 as "high memory". Accessing high memory is a little more costly 1436 than low memory, as it needs to be mapped into the kernel first. 1437 Note that increasing the kernel address space limits the range 1438 available to user programs, making the address space there 1439 tighter. Selecting anything other than the default 3G/1G split 1440 will also likely make your kernel incompatible with binary-only 1441 kernel modules. 1442 1443 If you are not absolutely sure what you are doing, leave this 1444 option alone! 1445 1446 config VMSPLIT_3G 1447 bool "3G/1G user/kernel split" 1448 config VMSPLIT_3G_OPT 1449 depends on !X86_PAE 1450 bool "3G/1G user/kernel split (for full 1G low memory)" 1451 config VMSPLIT_2G 1452 bool "2G/2G user/kernel split" 1453 config VMSPLIT_2G_OPT 1454 depends on !X86_PAE 1455 bool "2G/2G user/kernel split (for full 2G low memory)" 1456 config VMSPLIT_1G 1457 bool "1G/3G user/kernel split" 1458endchoice 1459 1460config PAGE_OFFSET 1461 hex 1462 default 0xB0000000 if VMSPLIT_3G_OPT 1463 default 0x80000000 if VMSPLIT_2G 1464 default 0x78000000 if VMSPLIT_2G_OPT 1465 default 0x40000000 if VMSPLIT_1G 1466 default 0xC0000000 1467 depends on X86_32 1468 1469config HIGHMEM 1470 def_bool y 1471 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1472 1473config X86_PAE 1474 bool "PAE (Physical Address Extension) Support" 1475 depends on X86_32 && !HIGHMEM4G 1476 select PHYS_ADDR_T_64BIT 1477 select SWIOTLB 1478 help 1479 PAE is required for NX support, and furthermore enables 1480 larger swapspace support for non-overcommit purposes. It 1481 has the cost of more pagetable lookup overhead, and also 1482 consumes more pagetable space per process. 1483 1484config X86_5LEVEL 1485 bool "Enable 5-level page tables support" 1486 default y 1487 select DYNAMIC_MEMORY_LAYOUT 1488 select SPARSEMEM_VMEMMAP 1489 depends on X86_64 1490 help 1491 5-level paging enables access to larger address space: 1492 upto 128 PiB of virtual address space and 4 PiB of 1493 physical address space. 1494 1495 It will be supported by future Intel CPUs. 1496 1497 A kernel with the option enabled can be booted on machines that 1498 support 4- or 5-level paging. 1499 1500 See Documentation/x86/x86_64/5level-paging.rst for more 1501 information. 1502 1503 Say N if unsure. 1504 1505config X86_DIRECT_GBPAGES 1506 def_bool y 1507 depends on X86_64 1508 help 1509 Certain kernel features effectively disable kernel 1510 linear 1 GB mappings (even if the CPU otherwise 1511 supports them), so don't confuse the user by printing 1512 that we have them enabled. 1513 1514config X86_CPA_STATISTICS 1515 bool "Enable statistic for Change Page Attribute" 1516 depends on DEBUG_FS 1517 help 1518 Expose statistics about the Change Page Attribute mechanism, which 1519 helps to determine the effectiveness of preserving large and huge 1520 page mappings when mapping protections are changed. 1521 1522config AMD_MEM_ENCRYPT 1523 bool "AMD Secure Memory Encryption (SME) support" 1524 depends on X86_64 && CPU_SUP_AMD 1525 select DMA_COHERENT_POOL 1526 select DYNAMIC_PHYSICAL_MASK 1527 select ARCH_USE_MEMREMAP_PROT 1528 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1529 select INSTRUCTION_DECODER 1530 help 1531 Say yes to enable support for the encryption of system memory. 1532 This requires an AMD processor that supports Secure Memory 1533 Encryption (SME). 1534 1535config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1536 bool "Activate AMD Secure Memory Encryption (SME) by default" 1537 default y 1538 depends on AMD_MEM_ENCRYPT 1539 help 1540 Say yes to have system memory encrypted by default if running on 1541 an AMD processor that supports Secure Memory Encryption (SME). 1542 1543 If set to Y, then the encryption of system memory can be 1544 deactivated with the mem_encrypt=off command line option. 1545 1546 If set to N, then the encryption of system memory can be 1547 activated with the mem_encrypt=on command line option. 1548 1549# Common NUMA Features 1550config NUMA 1551 bool "NUMA Memory Allocation and Scheduler Support" 1552 depends on SMP 1553 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1554 default y if X86_BIGSMP 1555 help 1556 Enable NUMA (Non-Uniform Memory Access) support. 1557 1558 The kernel will try to allocate memory used by a CPU on the 1559 local memory controller of the CPU and add some more 1560 NUMA awareness to the kernel. 1561 1562 For 64-bit this is recommended if the system is Intel Core i7 1563 (or later), AMD Opteron, or EM64T NUMA. 1564 1565 For 32-bit this is only needed if you boot a 32-bit 1566 kernel on a 64-bit NUMA platform. 1567 1568 Otherwise, you should say N. 1569 1570config AMD_NUMA 1571 def_bool y 1572 prompt "Old style AMD Opteron NUMA detection" 1573 depends on X86_64 && NUMA && PCI 1574 help 1575 Enable AMD NUMA node topology detection. You should say Y here if 1576 you have a multi processor AMD system. This uses an old method to 1577 read the NUMA configuration directly from the builtin Northbridge 1578 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1579 which also takes priority if both are compiled in. 1580 1581config X86_64_ACPI_NUMA 1582 def_bool y 1583 prompt "ACPI NUMA detection" 1584 depends on X86_64 && NUMA && ACPI && PCI 1585 select ACPI_NUMA 1586 help 1587 Enable ACPI SRAT based node topology detection. 1588 1589config NUMA_EMU 1590 bool "NUMA emulation" 1591 depends on NUMA 1592 help 1593 Enable NUMA emulation. A flat machine will be split 1594 into virtual nodes when booted with "numa=fake=N", where N is the 1595 number of nodes. This is only useful for debugging. 1596 1597config NODES_SHIFT 1598 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1599 range 1 10 1600 default "10" if MAXSMP 1601 default "6" if X86_64 1602 default "3" 1603 depends on NEED_MULTIPLE_NODES 1604 help 1605 Specify the maximum number of NUMA Nodes available on the target 1606 system. Increases memory reserved to accommodate various tables. 1607 1608config ARCH_FLATMEM_ENABLE 1609 def_bool y 1610 depends on X86_32 && !NUMA 1611 1612config ARCH_SPARSEMEM_ENABLE 1613 def_bool y 1614 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1615 select SPARSEMEM_STATIC if X86_32 1616 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1617 1618config ARCH_SPARSEMEM_DEFAULT 1619 def_bool X86_64 || (NUMA && X86_32) 1620 1621config ARCH_SELECT_MEMORY_MODEL 1622 def_bool y 1623 depends on ARCH_SPARSEMEM_ENABLE 1624 1625config ARCH_MEMORY_PROBE 1626 bool "Enable sysfs memory/probe interface" 1627 depends on X86_64 && MEMORY_HOTPLUG 1628 help 1629 This option enables a sysfs memory/probe interface for testing. 1630 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1631 If you are unsure how to answer this question, answer N. 1632 1633config ARCH_PROC_KCORE_TEXT 1634 def_bool y 1635 depends on X86_64 && PROC_KCORE 1636 1637config ILLEGAL_POINTER_VALUE 1638 hex 1639 default 0 if X86_32 1640 default 0xdead000000000000 if X86_64 1641 1642config X86_PMEM_LEGACY_DEVICE 1643 bool 1644 1645config X86_PMEM_LEGACY 1646 tristate "Support non-standard NVDIMMs and ADR protected memory" 1647 depends on PHYS_ADDR_T_64BIT 1648 depends on BLK_DEV 1649 select X86_PMEM_LEGACY_DEVICE 1650 select NUMA_KEEP_MEMINFO if NUMA 1651 select LIBNVDIMM 1652 help 1653 Treat memory marked using the non-standard e820 type of 12 as used 1654 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1655 The kernel will offer these regions to the 'pmem' driver so 1656 they can be used for persistent storage. 1657 1658 Say Y if unsure. 1659 1660config HIGHPTE 1661 bool "Allocate 3rd-level pagetables from highmem" 1662 depends on HIGHMEM 1663 help 1664 The VM uses one page table entry for each page of physical memory. 1665 For systems with a lot of RAM, this can be wasteful of precious 1666 low memory. Setting this option will put user-space page table 1667 entries in high memory. 1668 1669config X86_CHECK_BIOS_CORRUPTION 1670 bool "Check for low memory corruption" 1671 help 1672 Periodically check for memory corruption in low memory, which 1673 is suspected to be caused by BIOS. Even when enabled in the 1674 configuration, it is disabled at runtime. Enable it by 1675 setting "memory_corruption_check=1" on the kernel command 1676 line. By default it scans the low 64k of memory every 60 1677 seconds; see the memory_corruption_check_size and 1678 memory_corruption_check_period parameters in 1679 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1680 1681 When enabled with the default parameters, this option has 1682 almost no overhead, as it reserves a relatively small amount 1683 of memory and scans it infrequently. It both detects corruption 1684 and prevents it from affecting the running system. 1685 1686 It is, however, intended as a diagnostic tool; if repeatable 1687 BIOS-originated corruption always affects the same memory, 1688 you can use memmap= to prevent the kernel from using that 1689 memory. 1690 1691config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1692 bool "Set the default setting of memory_corruption_check" 1693 depends on X86_CHECK_BIOS_CORRUPTION 1694 default y 1695 help 1696 Set whether the default state of memory_corruption_check is 1697 on or off. 1698 1699config X86_RESERVE_LOW 1700 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1701 default 64 1702 range 4 640 1703 help 1704 Specify the amount of low memory to reserve for the BIOS. 1705 1706 The first page contains BIOS data structures that the kernel 1707 must not use, so that page must always be reserved. 1708 1709 By default we reserve the first 64K of physical RAM, as a 1710 number of BIOSes are known to corrupt that memory range 1711 during events such as suspend/resume or monitor cable 1712 insertion, so it must not be used by the kernel. 1713 1714 You can set this to 4 if you are absolutely sure that you 1715 trust the BIOS to get all its memory reservations and usages 1716 right. If you know your BIOS have problems beyond the 1717 default 64K area, you can set this to 640 to avoid using the 1718 entire low memory range. 1719 1720 If you have doubts about the BIOS (e.g. suspend/resume does 1721 not work or there's kernel crashes after certain hardware 1722 hotplug events) then you might want to enable 1723 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1724 typical corruption patterns. 1725 1726 Leave this to the default value of 64 if you are unsure. 1727 1728config MATH_EMULATION 1729 bool 1730 depends on MODIFY_LDT_SYSCALL 1731 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1732 help 1733 Linux can emulate a math coprocessor (used for floating point 1734 operations) if you don't have one. 486DX and Pentium processors have 1735 a math coprocessor built in, 486SX and 386 do not, unless you added 1736 a 487DX or 387, respectively. (The messages during boot time can 1737 give you some hints here ["man dmesg"].) Everyone needs either a 1738 coprocessor or this emulation. 1739 1740 If you don't have a math coprocessor, you need to say Y here; if you 1741 say Y here even though you have a coprocessor, the coprocessor will 1742 be used nevertheless. (This behavior can be changed with the kernel 1743 command line option "no387", which comes handy if your coprocessor 1744 is broken. Try "man bootparam" or see the documentation of your boot 1745 loader (lilo or loadlin) about how to pass options to the kernel at 1746 boot time.) This means that it is a good idea to say Y here if you 1747 intend to use this kernel on different machines. 1748 1749 More information about the internals of the Linux math coprocessor 1750 emulation can be found in <file:arch/x86/math-emu/README>. 1751 1752 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1753 kernel, it won't hurt. 1754 1755config MTRR 1756 def_bool y 1757 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1758 help 1759 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1760 the Memory Type Range Registers (MTRRs) may be used to control 1761 processor access to memory ranges. This is most useful if you have 1762 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1763 allows bus write transfers to be combined into a larger transfer 1764 before bursting over the PCI/AGP bus. This can increase performance 1765 of image write operations 2.5 times or more. Saying Y here creates a 1766 /proc/mtrr file which may be used to manipulate your processor's 1767 MTRRs. Typically the X server should use this. 1768 1769 This code has a reasonably generic interface so that similar 1770 control registers on other processors can be easily supported 1771 as well: 1772 1773 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1774 Registers (ARRs) which provide a similar functionality to MTRRs. For 1775 these, the ARRs are used to emulate the MTRRs. 1776 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1777 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1778 write-combining. All of these processors are supported by this code 1779 and it makes sense to say Y here if you have one of them. 1780 1781 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1782 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1783 can lead to all sorts of problems, so it's good to say Y here. 1784 1785 You can safely say Y even if your machine doesn't have MTRRs, you'll 1786 just add about 9 KB to your kernel. 1787 1788 See <file:Documentation/x86/mtrr.rst> for more information. 1789 1790config MTRR_SANITIZER 1791 def_bool y 1792 prompt "MTRR cleanup support" 1793 depends on MTRR 1794 help 1795 Convert MTRR layout from continuous to discrete, so X drivers can 1796 add writeback entries. 1797 1798 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1799 The largest mtrr entry size for a continuous block can be set with 1800 mtrr_chunk_size. 1801 1802 If unsure, say Y. 1803 1804config MTRR_SANITIZER_ENABLE_DEFAULT 1805 int "MTRR cleanup enable value (0-1)" 1806 range 0 1 1807 default "0" 1808 depends on MTRR_SANITIZER 1809 help 1810 Enable mtrr cleanup default value 1811 1812config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1813 int "MTRR cleanup spare reg num (0-7)" 1814 range 0 7 1815 default "1" 1816 depends on MTRR_SANITIZER 1817 help 1818 mtrr cleanup spare entries default, it can be changed via 1819 mtrr_spare_reg_nr=N on the kernel command line. 1820 1821config X86_PAT 1822 def_bool y 1823 prompt "x86 PAT support" if EXPERT 1824 depends on MTRR 1825 help 1826 Use PAT attributes to setup page level cache control. 1827 1828 PATs are the modern equivalents of MTRRs and are much more 1829 flexible than MTRRs. 1830 1831 Say N here if you see bootup problems (boot crash, boot hang, 1832 spontaneous reboots) or a non-working video driver. 1833 1834 If unsure, say Y. 1835 1836config ARCH_USES_PG_UNCACHED 1837 def_bool y 1838 depends on X86_PAT 1839 1840config ARCH_RANDOM 1841 def_bool y 1842 prompt "x86 architectural random number generator" if EXPERT 1843 help 1844 Enable the x86 architectural RDRAND instruction 1845 (Intel Bull Mountain technology) to generate random numbers. 1846 If supported, this is a high bandwidth, cryptographically 1847 secure hardware random number generator. 1848 1849config X86_SMAP 1850 def_bool y 1851 prompt "Supervisor Mode Access Prevention" if EXPERT 1852 help 1853 Supervisor Mode Access Prevention (SMAP) is a security 1854 feature in newer Intel processors. There is a small 1855 performance cost if this enabled and turned on; there is 1856 also a small increase in the kernel size if this is enabled. 1857 1858 If unsure, say Y. 1859 1860config X86_UMIP 1861 def_bool y 1862 prompt "User Mode Instruction Prevention" if EXPERT 1863 help 1864 User Mode Instruction Prevention (UMIP) is a security feature in 1865 some x86 processors. If enabled, a general protection fault is 1866 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1867 executed in user mode. These instructions unnecessarily expose 1868 information about the hardware state. 1869 1870 The vast majority of applications do not use these instructions. 1871 For the very few that do, software emulation is provided in 1872 specific cases in protected and virtual-8086 modes. Emulated 1873 results are dummy. 1874 1875config X86_INTEL_MEMORY_PROTECTION_KEYS 1876 prompt "Memory Protection Keys" 1877 def_bool y 1878 # Note: only available in 64-bit mode 1879 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1880 select ARCH_USES_HIGH_VMA_FLAGS 1881 select ARCH_HAS_PKEYS 1882 help 1883 Memory Protection Keys provides a mechanism for enforcing 1884 page-based protections, but without requiring modification of the 1885 page tables when an application changes protection domains. 1886 1887 For details, see Documentation/core-api/protection-keys.rst 1888 1889 If unsure, say y. 1890 1891choice 1892 prompt "TSX enable mode" 1893 depends on CPU_SUP_INTEL 1894 default X86_INTEL_TSX_MODE_OFF 1895 help 1896 Intel's TSX (Transactional Synchronization Extensions) feature 1897 allows to optimize locking protocols through lock elision which 1898 can lead to a noticeable performance boost. 1899 1900 On the other hand it has been shown that TSX can be exploited 1901 to form side channel attacks (e.g. TAA) and chances are there 1902 will be more of those attacks discovered in the future. 1903 1904 Therefore TSX is not enabled by default (aka tsx=off). An admin 1905 might override this decision by tsx=on the command line parameter. 1906 Even with TSX enabled, the kernel will attempt to enable the best 1907 possible TAA mitigation setting depending on the microcode available 1908 for the particular machine. 1909 1910 This option allows to set the default tsx mode between tsx=on, =off 1911 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1912 details. 1913 1914 Say off if not sure, auto if TSX is in use but it should be used on safe 1915 platforms or on if TSX is in use and the security aspect of tsx is not 1916 relevant. 1917 1918config X86_INTEL_TSX_MODE_OFF 1919 bool "off" 1920 help 1921 TSX is disabled if possible - equals to tsx=off command line parameter. 1922 1923config X86_INTEL_TSX_MODE_ON 1924 bool "on" 1925 help 1926 TSX is always enabled on TSX capable HW - equals the tsx=on command 1927 line parameter. 1928 1929config X86_INTEL_TSX_MODE_AUTO 1930 bool "auto" 1931 help 1932 TSX is enabled on TSX capable HW that is believed to be safe against 1933 side channel attacks- equals the tsx=auto command line parameter. 1934endchoice 1935 1936config X86_SGX 1937 bool "Software Guard eXtensions (SGX)" 1938 depends on X86_64 && CPU_SUP_INTEL 1939 depends on CRYPTO=y 1940 depends on CRYPTO_SHA256=y 1941 select SRCU 1942 select MMU_NOTIFIER 1943 help 1944 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1945 that can be used by applications to set aside private regions of code 1946 and data, referred to as enclaves. An enclave's private memory can 1947 only be accessed by code running within the enclave. Accesses from 1948 outside the enclave, including other enclaves, are disallowed by 1949 hardware. 1950 1951 If unsure, say N. 1952 1953config EFI 1954 bool "EFI runtime service support" 1955 depends on ACPI 1956 select UCS2_STRING 1957 select EFI_RUNTIME_WRAPPERS 1958 help 1959 This enables the kernel to use EFI runtime services that are 1960 available (such as the EFI variable services). 1961 1962 This option is only useful on systems that have EFI firmware. 1963 In addition, you should use the latest ELILO loader available 1964 at <http://elilo.sourceforge.net> in order to take advantage 1965 of EFI runtime services. However, even with this option, the 1966 resultant kernel should continue to boot on existing non-EFI 1967 platforms. 1968 1969config EFI_STUB 1970 bool "EFI stub support" 1971 depends on EFI && !X86_USE_3DNOW 1972 depends on $(cc-option,-mabi=ms) || X86_32 1973 select RELOCATABLE 1974 help 1975 This kernel feature allows a bzImage to be loaded directly 1976 by EFI firmware without the use of a bootloader. 1977 1978 See Documentation/admin-guide/efi-stub.rst for more information. 1979 1980config EFI_MIXED 1981 bool "EFI mixed-mode support" 1982 depends on EFI_STUB && X86_64 1983 help 1984 Enabling this feature allows a 64-bit kernel to be booted 1985 on a 32-bit firmware, provided that your CPU supports 64-bit 1986 mode. 1987 1988 Note that it is not possible to boot a mixed-mode enabled 1989 kernel via the EFI boot stub - a bootloader that supports 1990 the EFI handover protocol must be used. 1991 1992 If unsure, say N. 1993 1994source "kernel/Kconfig.hz" 1995 1996config KEXEC 1997 bool "kexec system call" 1998 select KEXEC_CORE 1999 help 2000 kexec is a system call that implements the ability to shutdown your 2001 current kernel, and to start another kernel. It is like a reboot 2002 but it is independent of the system firmware. And like a reboot 2003 you can start any kernel with it, not just Linux. 2004 2005 The name comes from the similarity to the exec system call. 2006 2007 It is an ongoing process to be certain the hardware in a machine 2008 is properly shutdown, so do not be surprised if this code does not 2009 initially work for you. As of this writing the exact hardware 2010 interface is strongly in flux, so no good recommendation can be 2011 made. 2012 2013config KEXEC_FILE 2014 bool "kexec file based system call" 2015 select KEXEC_CORE 2016 select BUILD_BIN2C 2017 depends on X86_64 2018 depends on CRYPTO=y 2019 depends on CRYPTO_SHA256=y 2020 help 2021 This is new version of kexec system call. This system call is 2022 file based and takes file descriptors as system call argument 2023 for kernel and initramfs as opposed to list of segments as 2024 accepted by previous system call. 2025 2026config ARCH_HAS_KEXEC_PURGATORY 2027 def_bool KEXEC_FILE 2028 2029config KEXEC_SIG 2030 bool "Verify kernel signature during kexec_file_load() syscall" 2031 depends on KEXEC_FILE 2032 help 2033 2034 This option makes the kexec_file_load() syscall check for a valid 2035 signature of the kernel image. The image can still be loaded without 2036 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2037 there's a signature that we can check, then it must be valid. 2038 2039 In addition to this option, you need to enable signature 2040 verification for the corresponding kernel image type being 2041 loaded in order for this to work. 2042 2043config KEXEC_SIG_FORCE 2044 bool "Require a valid signature in kexec_file_load() syscall" 2045 depends on KEXEC_SIG 2046 help 2047 This option makes kernel signature verification mandatory for 2048 the kexec_file_load() syscall. 2049 2050config KEXEC_BZIMAGE_VERIFY_SIG 2051 bool "Enable bzImage signature verification support" 2052 depends on KEXEC_SIG 2053 depends on SIGNED_PE_FILE_VERIFICATION 2054 select SYSTEM_TRUSTED_KEYRING 2055 help 2056 Enable bzImage signature verification support. 2057 2058config CRASH_DUMP 2059 bool "kernel crash dumps" 2060 depends on X86_64 || (X86_32 && HIGHMEM) 2061 help 2062 Generate crash dump after being started by kexec. 2063 This should be normally only set in special crash dump kernels 2064 which are loaded in the main kernel with kexec-tools into 2065 a specially reserved region and then later executed after 2066 a crash by kdump/kexec. The crash dump kernel must be compiled 2067 to a memory address not used by the main kernel or BIOS using 2068 PHYSICAL_START, or it must be built as a relocatable image 2069 (CONFIG_RELOCATABLE=y). 2070 For more details see Documentation/admin-guide/kdump/kdump.rst 2071 2072config KEXEC_JUMP 2073 bool "kexec jump" 2074 depends on KEXEC && HIBERNATION 2075 help 2076 Jump between original kernel and kexeced kernel and invoke 2077 code in physical address mode via KEXEC 2078 2079config PHYSICAL_START 2080 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2081 default "0x1000000" 2082 help 2083 This gives the physical address where the kernel is loaded. 2084 2085 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2086 bzImage will decompress itself to above physical address and 2087 run from there. Otherwise, bzImage will run from the address where 2088 it has been loaded by the boot loader and will ignore above physical 2089 address. 2090 2091 In normal kdump cases one does not have to set/change this option 2092 as now bzImage can be compiled as a completely relocatable image 2093 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2094 address. This option is mainly useful for the folks who don't want 2095 to use a bzImage for capturing the crash dump and want to use a 2096 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2097 to be specifically compiled to run from a specific memory area 2098 (normally a reserved region) and this option comes handy. 2099 2100 So if you are using bzImage for capturing the crash dump, 2101 leave the value here unchanged to 0x1000000 and set 2102 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2103 for capturing the crash dump change this value to start of 2104 the reserved region. In other words, it can be set based on 2105 the "X" value as specified in the "crashkernel=YM@XM" 2106 command line boot parameter passed to the panic-ed 2107 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2108 for more details about crash dumps. 2109 2110 Usage of bzImage for capturing the crash dump is recommended as 2111 one does not have to build two kernels. Same kernel can be used 2112 as production kernel and capture kernel. Above option should have 2113 gone away after relocatable bzImage support is introduced. But it 2114 is present because there are users out there who continue to use 2115 vmlinux for dump capture. This option should go away down the 2116 line. 2117 2118 Don't change this unless you know what you are doing. 2119 2120config RELOCATABLE 2121 bool "Build a relocatable kernel" 2122 default y 2123 help 2124 This builds a kernel image that retains relocation information 2125 so it can be loaded someplace besides the default 1MB. 2126 The relocations tend to make the kernel binary about 10% larger, 2127 but are discarded at runtime. 2128 2129 One use is for the kexec on panic case where the recovery kernel 2130 must live at a different physical address than the primary 2131 kernel. 2132 2133 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2134 it has been loaded at and the compile time physical address 2135 (CONFIG_PHYSICAL_START) is used as the minimum location. 2136 2137config RANDOMIZE_BASE 2138 bool "Randomize the address of the kernel image (KASLR)" 2139 depends on RELOCATABLE 2140 default y 2141 help 2142 In support of Kernel Address Space Layout Randomization (KASLR), 2143 this randomizes the physical address at which the kernel image 2144 is decompressed and the virtual address where the kernel 2145 image is mapped, as a security feature that deters exploit 2146 attempts relying on knowledge of the location of kernel 2147 code internals. 2148 2149 On 64-bit, the kernel physical and virtual addresses are 2150 randomized separately. The physical address will be anywhere 2151 between 16MB and the top of physical memory (up to 64TB). The 2152 virtual address will be randomized from 16MB up to 1GB (9 bits 2153 of entropy). Note that this also reduces the memory space 2154 available to kernel modules from 1.5GB to 1GB. 2155 2156 On 32-bit, the kernel physical and virtual addresses are 2157 randomized together. They will be randomized from 16MB up to 2158 512MB (8 bits of entropy). 2159 2160 Entropy is generated using the RDRAND instruction if it is 2161 supported. If RDTSC is supported, its value is mixed into 2162 the entropy pool as well. If neither RDRAND nor RDTSC are 2163 supported, then entropy is read from the i8254 timer. The 2164 usable entropy is limited by the kernel being built using 2165 2GB addressing, and that PHYSICAL_ALIGN must be at a 2166 minimum of 2MB. As a result, only 10 bits of entropy are 2167 theoretically possible, but the implementations are further 2168 limited due to memory layouts. 2169 2170 If unsure, say Y. 2171 2172# Relocation on x86 needs some additional build support 2173config X86_NEED_RELOCS 2174 def_bool y 2175 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2176 2177config PHYSICAL_ALIGN 2178 hex "Alignment value to which kernel should be aligned" 2179 default "0x200000" 2180 range 0x2000 0x1000000 if X86_32 2181 range 0x200000 0x1000000 if X86_64 2182 help 2183 This value puts the alignment restrictions on physical address 2184 where kernel is loaded and run from. Kernel is compiled for an 2185 address which meets above alignment restriction. 2186 2187 If bootloader loads the kernel at a non-aligned address and 2188 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2189 address aligned to above value and run from there. 2190 2191 If bootloader loads the kernel at a non-aligned address and 2192 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2193 load address and decompress itself to the address it has been 2194 compiled for and run from there. The address for which kernel is 2195 compiled already meets above alignment restrictions. Hence the 2196 end result is that kernel runs from a physical address meeting 2197 above alignment restrictions. 2198 2199 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2200 this value must be a multiple of 0x200000. 2201 2202 Don't change this unless you know what you are doing. 2203 2204config DYNAMIC_MEMORY_LAYOUT 2205 bool 2206 help 2207 This option makes base addresses of vmalloc and vmemmap as well as 2208 __PAGE_OFFSET movable during boot. 2209 2210config RANDOMIZE_MEMORY 2211 bool "Randomize the kernel memory sections" 2212 depends on X86_64 2213 depends on RANDOMIZE_BASE 2214 select DYNAMIC_MEMORY_LAYOUT 2215 default RANDOMIZE_BASE 2216 help 2217 Randomizes the base virtual address of kernel memory sections 2218 (physical memory mapping, vmalloc & vmemmap). This security feature 2219 makes exploits relying on predictable memory locations less reliable. 2220 2221 The order of allocations remains unchanged. Entropy is generated in 2222 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2223 configuration have in average 30,000 different possible virtual 2224 addresses for each memory section. 2225 2226 If unsure, say Y. 2227 2228config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2229 hex "Physical memory mapping padding" if EXPERT 2230 depends on RANDOMIZE_MEMORY 2231 default "0xa" if MEMORY_HOTPLUG 2232 default "0x0" 2233 range 0x1 0x40 if MEMORY_HOTPLUG 2234 range 0x0 0x40 2235 help 2236 Define the padding in terabytes added to the existing physical 2237 memory size during kernel memory randomization. It is useful 2238 for memory hotplug support but reduces the entropy available for 2239 address randomization. 2240 2241 If unsure, leave at the default value. 2242 2243config HOTPLUG_CPU 2244 def_bool y 2245 depends on SMP 2246 2247config BOOTPARAM_HOTPLUG_CPU0 2248 bool "Set default setting of cpu0_hotpluggable" 2249 depends on HOTPLUG_CPU 2250 help 2251 Set whether default state of cpu0_hotpluggable is on or off. 2252 2253 Say Y here to enable CPU0 hotplug by default. If this switch 2254 is turned on, there is no need to give cpu0_hotplug kernel 2255 parameter and the CPU0 hotplug feature is enabled by default. 2256 2257 Please note: there are two known CPU0 dependencies if you want 2258 to enable the CPU0 hotplug feature either by this switch or by 2259 cpu0_hotplug kernel parameter. 2260 2261 First, resume from hibernate or suspend always starts from CPU0. 2262 So hibernate and suspend are prevented if CPU0 is offline. 2263 2264 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2265 offline if any interrupt can not migrate out of CPU0. There may 2266 be other CPU0 dependencies. 2267 2268 Please make sure the dependencies are under your control before 2269 you enable this feature. 2270 2271 Say N if you don't want to enable CPU0 hotplug feature by default. 2272 You still can enable the CPU0 hotplug feature at boot by kernel 2273 parameter cpu0_hotplug. 2274 2275config DEBUG_HOTPLUG_CPU0 2276 def_bool n 2277 prompt "Debug CPU0 hotplug" 2278 depends on HOTPLUG_CPU 2279 help 2280 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2281 soon as possible and boots up userspace with CPU0 offlined. User 2282 can online CPU0 back after boot time. 2283 2284 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2285 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2286 compilation or giving cpu0_hotplug kernel parameter at boot. 2287 2288 If unsure, say N. 2289 2290config COMPAT_VDSO 2291 def_bool n 2292 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2293 depends on COMPAT_32 2294 help 2295 Certain buggy versions of glibc will crash if they are 2296 presented with a 32-bit vDSO that is not mapped at the address 2297 indicated in its segment table. 2298 2299 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2300 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2301 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2302 the only released version with the bug, but OpenSUSE 9 2303 contains a buggy "glibc 2.3.2". 2304 2305 The symptom of the bug is that everything crashes on startup, saying: 2306 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2307 2308 Saying Y here changes the default value of the vdso32 boot 2309 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2310 This works around the glibc bug but hurts performance. 2311 2312 If unsure, say N: if you are compiling your own kernel, you 2313 are unlikely to be using a buggy version of glibc. 2314 2315choice 2316 prompt "vsyscall table for legacy applications" 2317 depends on X86_64 2318 default LEGACY_VSYSCALL_XONLY 2319 help 2320 Legacy user code that does not know how to find the vDSO expects 2321 to be able to issue three syscalls by calling fixed addresses in 2322 kernel space. Since this location is not randomized with ASLR, 2323 it can be used to assist security vulnerability exploitation. 2324 2325 This setting can be changed at boot time via the kernel command 2326 line parameter vsyscall=[emulate|xonly|none]. 2327 2328 On a system with recent enough glibc (2.14 or newer) and no 2329 static binaries, you can say None without a performance penalty 2330 to improve security. 2331 2332 If unsure, select "Emulate execution only". 2333 2334 config LEGACY_VSYSCALL_EMULATE 2335 bool "Full emulation" 2336 help 2337 The kernel traps and emulates calls into the fixed vsyscall 2338 address mapping. This makes the mapping non-executable, but 2339 it still contains readable known contents, which could be 2340 used in certain rare security vulnerability exploits. This 2341 configuration is recommended when using legacy userspace 2342 that still uses vsyscalls along with legacy binary 2343 instrumentation tools that require code to be readable. 2344 2345 An example of this type of legacy userspace is running 2346 Pin on an old binary that still uses vsyscalls. 2347 2348 config LEGACY_VSYSCALL_XONLY 2349 bool "Emulate execution only" 2350 help 2351 The kernel traps and emulates calls into the fixed vsyscall 2352 address mapping and does not allow reads. This 2353 configuration is recommended when userspace might use the 2354 legacy vsyscall area but support for legacy binary 2355 instrumentation of legacy code is not needed. It mitigates 2356 certain uses of the vsyscall area as an ASLR-bypassing 2357 buffer. 2358 2359 config LEGACY_VSYSCALL_NONE 2360 bool "None" 2361 help 2362 There will be no vsyscall mapping at all. This will 2363 eliminate any risk of ASLR bypass due to the vsyscall 2364 fixed address mapping. Attempts to use the vsyscalls 2365 will be reported to dmesg, so that either old or 2366 malicious userspace programs can be identified. 2367 2368endchoice 2369 2370config CMDLINE_BOOL 2371 bool "Built-in kernel command line" 2372 help 2373 Allow for specifying boot arguments to the kernel at 2374 build time. On some systems (e.g. embedded ones), it is 2375 necessary or convenient to provide some or all of the 2376 kernel boot arguments with the kernel itself (that is, 2377 to not rely on the boot loader to provide them.) 2378 2379 To compile command line arguments into the kernel, 2380 set this option to 'Y', then fill in the 2381 boot arguments in CONFIG_CMDLINE. 2382 2383 Systems with fully functional boot loaders (i.e. non-embedded) 2384 should leave this option set to 'N'. 2385 2386config CMDLINE 2387 string "Built-in kernel command string" 2388 depends on CMDLINE_BOOL 2389 default "" 2390 help 2391 Enter arguments here that should be compiled into the kernel 2392 image and used at boot time. If the boot loader provides a 2393 command line at boot time, it is appended to this string to 2394 form the full kernel command line, when the system boots. 2395 2396 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2397 change this behavior. 2398 2399 In most cases, the command line (whether built-in or provided 2400 by the boot loader) should specify the device for the root 2401 file system. 2402 2403config CMDLINE_OVERRIDE 2404 bool "Built-in command line overrides boot loader arguments" 2405 depends on CMDLINE_BOOL && CMDLINE != "" 2406 help 2407 Set this option to 'Y' to have the kernel ignore the boot loader 2408 command line, and use ONLY the built-in command line. 2409 2410 This is used to work around broken boot loaders. This should 2411 be set to 'N' under normal conditions. 2412 2413config MODIFY_LDT_SYSCALL 2414 bool "Enable the LDT (local descriptor table)" if EXPERT 2415 default y 2416 help 2417 Linux can allow user programs to install a per-process x86 2418 Local Descriptor Table (LDT) using the modify_ldt(2) system 2419 call. This is required to run 16-bit or segmented code such as 2420 DOSEMU or some Wine programs. It is also used by some very old 2421 threading libraries. 2422 2423 Enabling this feature adds a small amount of overhead to 2424 context switches and increases the low-level kernel attack 2425 surface. Disabling it removes the modify_ldt(2) system call. 2426 2427 Saying 'N' here may make sense for embedded or server kernels. 2428 2429source "kernel/livepatch/Kconfig" 2430 2431endmenu 2432 2433config ARCH_HAS_ADD_PAGES 2434 def_bool y 2435 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2436 2437config ARCH_ENABLE_MEMORY_HOTPLUG 2438 def_bool y 2439 depends on X86_64 || (X86_32 && HIGHMEM) 2440 2441config ARCH_ENABLE_MEMORY_HOTREMOVE 2442 def_bool y 2443 depends on MEMORY_HOTPLUG 2444 2445config USE_PERCPU_NUMA_NODE_ID 2446 def_bool y 2447 depends on NUMA 2448 2449config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2450 def_bool y 2451 depends on X86_64 || X86_PAE 2452 2453config ARCH_ENABLE_HUGEPAGE_MIGRATION 2454 def_bool y 2455 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2456 2457config ARCH_ENABLE_THP_MIGRATION 2458 def_bool y 2459 depends on X86_64 && TRANSPARENT_HUGEPAGE 2460 2461menu "Power management and ACPI options" 2462 2463config ARCH_HIBERNATION_HEADER 2464 def_bool y 2465 depends on HIBERNATION 2466 2467source "kernel/power/Kconfig" 2468 2469source "drivers/acpi/Kconfig" 2470 2471source "drivers/sfi/Kconfig" 2472 2473config X86_APM_BOOT 2474 def_bool y 2475 depends on APM 2476 2477menuconfig APM 2478 tristate "APM (Advanced Power Management) BIOS support" 2479 depends on X86_32 && PM_SLEEP 2480 help 2481 APM is a BIOS specification for saving power using several different 2482 techniques. This is mostly useful for battery powered laptops with 2483 APM compliant BIOSes. If you say Y here, the system time will be 2484 reset after a RESUME operation, the /proc/apm device will provide 2485 battery status information, and user-space programs will receive 2486 notification of APM "events" (e.g. battery status change). 2487 2488 If you select "Y" here, you can disable actual use of the APM 2489 BIOS by passing the "apm=off" option to the kernel at boot time. 2490 2491 Note that the APM support is almost completely disabled for 2492 machines with more than one CPU. 2493 2494 In order to use APM, you will need supporting software. For location 2495 and more information, read <file:Documentation/power/apm-acpi.rst> 2496 and the Battery Powered Linux mini-HOWTO, available from 2497 <http://www.tldp.org/docs.html#howto>. 2498 2499 This driver does not spin down disk drives (see the hdparm(8) 2500 manpage ("man 8 hdparm") for that), and it doesn't turn off 2501 VESA-compliant "green" monitors. 2502 2503 This driver does not support the TI 4000M TravelMate and the ACER 2504 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2505 desktop machines also don't have compliant BIOSes, and this driver 2506 may cause those machines to panic during the boot phase. 2507 2508 Generally, if you don't have a battery in your machine, there isn't 2509 much point in using this driver and you should say N. If you get 2510 random kernel OOPSes or reboots that don't seem to be related to 2511 anything, try disabling/enabling this option (or disabling/enabling 2512 APM in your BIOS). 2513 2514 Some other things you should try when experiencing seemingly random, 2515 "weird" problems: 2516 2517 1) make sure that you have enough swap space and that it is 2518 enabled. 2519 2) pass the "no-hlt" option to the kernel 2520 3) switch on floating point emulation in the kernel and pass 2521 the "no387" option to the kernel 2522 4) pass the "floppy=nodma" option to the kernel 2523 5) pass the "mem=4M" option to the kernel (thereby disabling 2524 all but the first 4 MB of RAM) 2525 6) make sure that the CPU is not over clocked. 2526 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2527 8) disable the cache from your BIOS settings 2528 9) install a fan for the video card or exchange video RAM 2529 10) install a better fan for the CPU 2530 11) exchange RAM chips 2531 12) exchange the motherboard. 2532 2533 To compile this driver as a module, choose M here: the 2534 module will be called apm. 2535 2536if APM 2537 2538config APM_IGNORE_USER_SUSPEND 2539 bool "Ignore USER SUSPEND" 2540 help 2541 This option will ignore USER SUSPEND requests. On machines with a 2542 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2543 series notebooks, it is necessary to say Y because of a BIOS bug. 2544 2545config APM_DO_ENABLE 2546 bool "Enable PM at boot time" 2547 help 2548 Enable APM features at boot time. From page 36 of the APM BIOS 2549 specification: "When disabled, the APM BIOS does not automatically 2550 power manage devices, enter the Standby State, enter the Suspend 2551 State, or take power saving steps in response to CPU Idle calls." 2552 This driver will make CPU Idle calls when Linux is idle (unless this 2553 feature is turned off -- see "Do CPU IDLE calls", below). This 2554 should always save battery power, but more complicated APM features 2555 will be dependent on your BIOS implementation. You may need to turn 2556 this option off if your computer hangs at boot time when using APM 2557 support, or if it beeps continuously instead of suspending. Turn 2558 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2559 T400CDT. This is off by default since most machines do fine without 2560 this feature. 2561 2562config APM_CPU_IDLE 2563 depends on CPU_IDLE 2564 bool "Make CPU Idle calls when idle" 2565 help 2566 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2567 On some machines, this can activate improved power savings, such as 2568 a slowed CPU clock rate, when the machine is idle. These idle calls 2569 are made after the idle loop has run for some length of time (e.g., 2570 333 mS). On some machines, this will cause a hang at boot time or 2571 whenever the CPU becomes idle. (On machines with more than one CPU, 2572 this option does nothing.) 2573 2574config APM_DISPLAY_BLANK 2575 bool "Enable console blanking using APM" 2576 help 2577 Enable console blanking using the APM. Some laptops can use this to 2578 turn off the LCD backlight when the screen blanker of the Linux 2579 virtual console blanks the screen. Note that this is only used by 2580 the virtual console screen blanker, and won't turn off the backlight 2581 when using the X Window system. This also doesn't have anything to 2582 do with your VESA-compliant power-saving monitor. Further, this 2583 option doesn't work for all laptops -- it might not turn off your 2584 backlight at all, or it might print a lot of errors to the console, 2585 especially if you are using gpm. 2586 2587config APM_ALLOW_INTS 2588 bool "Allow interrupts during APM BIOS calls" 2589 help 2590 Normally we disable external interrupts while we are making calls to 2591 the APM BIOS as a measure to lessen the effects of a badly behaving 2592 BIOS implementation. The BIOS should reenable interrupts if it 2593 needs to. Unfortunately, some BIOSes do not -- especially those in 2594 many of the newer IBM Thinkpads. If you experience hangs when you 2595 suspend, try setting this to Y. Otherwise, say N. 2596 2597endif # APM 2598 2599source "drivers/cpufreq/Kconfig" 2600 2601source "drivers/cpuidle/Kconfig" 2602 2603source "drivers/idle/Kconfig" 2604 2605endmenu 2606 2607 2608menu "Bus options (PCI etc.)" 2609 2610choice 2611 prompt "PCI access mode" 2612 depends on X86_32 && PCI 2613 default PCI_GOANY 2614 help 2615 On PCI systems, the BIOS can be used to detect the PCI devices and 2616 determine their configuration. However, some old PCI motherboards 2617 have BIOS bugs and may crash if this is done. Also, some embedded 2618 PCI-based systems don't have any BIOS at all. Linux can also try to 2619 detect the PCI hardware directly without using the BIOS. 2620 2621 With this option, you can specify how Linux should detect the 2622 PCI devices. If you choose "BIOS", the BIOS will be used, 2623 if you choose "Direct", the BIOS won't be used, and if you 2624 choose "MMConfig", then PCI Express MMCONFIG will be used. 2625 If you choose "Any", the kernel will try MMCONFIG, then the 2626 direct access method and falls back to the BIOS if that doesn't 2627 work. If unsure, go with the default, which is "Any". 2628 2629config PCI_GOBIOS 2630 bool "BIOS" 2631 2632config PCI_GOMMCONFIG 2633 bool "MMConfig" 2634 2635config PCI_GODIRECT 2636 bool "Direct" 2637 2638config PCI_GOOLPC 2639 bool "OLPC XO-1" 2640 depends on OLPC 2641 2642config PCI_GOANY 2643 bool "Any" 2644 2645endchoice 2646 2647config PCI_BIOS 2648 def_bool y 2649 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2650 2651# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2652config PCI_DIRECT 2653 def_bool y 2654 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2655 2656config PCI_MMCONFIG 2657 bool "Support mmconfig PCI config space access" if X86_64 2658 default y 2659 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2660 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2661 2662config PCI_OLPC 2663 def_bool y 2664 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2665 2666config PCI_XEN 2667 def_bool y 2668 depends on PCI && XEN 2669 select SWIOTLB_XEN 2670 2671config MMCONF_FAM10H 2672 def_bool y 2673 depends on X86_64 && PCI_MMCONFIG && ACPI 2674 2675config PCI_CNB20LE_QUIRK 2676 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2677 depends on PCI 2678 help 2679 Read the PCI windows out of the CNB20LE host bridge. This allows 2680 PCI hotplug to work on systems with the CNB20LE chipset which do 2681 not have ACPI. 2682 2683 There's no public spec for this chipset, and this functionality 2684 is known to be incomplete. 2685 2686 You should say N unless you know you need this. 2687 2688config ISA_BUS 2689 bool "ISA bus support on modern systems" if EXPERT 2690 help 2691 Expose ISA bus device drivers and options available for selection and 2692 configuration. Enable this option if your target machine has an ISA 2693 bus. ISA is an older system, displaced by PCI and newer bus 2694 architectures -- if your target machine is modern, it probably does 2695 not have an ISA bus. 2696 2697 If unsure, say N. 2698 2699# x86_64 have no ISA slots, but can have ISA-style DMA. 2700config ISA_DMA_API 2701 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2702 default y 2703 help 2704 Enables ISA-style DMA support for devices requiring such controllers. 2705 If unsure, say Y. 2706 2707if X86_32 2708 2709config ISA 2710 bool "ISA support" 2711 help 2712 Find out whether you have ISA slots on your motherboard. ISA is the 2713 name of a bus system, i.e. the way the CPU talks to the other stuff 2714 inside your box. Other bus systems are PCI, EISA, MicroChannel 2715 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2716 newer boards don't support it. If you have ISA, say Y, otherwise N. 2717 2718config SCx200 2719 tristate "NatSemi SCx200 support" 2720 help 2721 This provides basic support for National Semiconductor's 2722 (now AMD's) Geode processors. The driver probes for the 2723 PCI-IDs of several on-chip devices, so its a good dependency 2724 for other scx200_* drivers. 2725 2726 If compiled as a module, the driver is named scx200. 2727 2728config SCx200HR_TIMER 2729 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2730 depends on SCx200 2731 default y 2732 help 2733 This driver provides a clocksource built upon the on-chip 2734 27MHz high-resolution timer. Its also a workaround for 2735 NSC Geode SC-1100's buggy TSC, which loses time when the 2736 processor goes idle (as is done by the scheduler). The 2737 other workaround is idle=poll boot option. 2738 2739config OLPC 2740 bool "One Laptop Per Child support" 2741 depends on !X86_PAE 2742 select GPIOLIB 2743 select OF 2744 select OF_PROMTREE 2745 select IRQ_DOMAIN 2746 select OLPC_EC 2747 help 2748 Add support for detecting the unique features of the OLPC 2749 XO hardware. 2750 2751config OLPC_XO1_PM 2752 bool "OLPC XO-1 Power Management" 2753 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2754 help 2755 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2756 2757config OLPC_XO1_RTC 2758 bool "OLPC XO-1 Real Time Clock" 2759 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2760 help 2761 Add support for the XO-1 real time clock, which can be used as a 2762 programmable wakeup source. 2763 2764config OLPC_XO1_SCI 2765 bool "OLPC XO-1 SCI extras" 2766 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2767 depends on INPUT=y 2768 select POWER_SUPPLY 2769 help 2770 Add support for SCI-based features of the OLPC XO-1 laptop: 2771 - EC-driven system wakeups 2772 - Power button 2773 - Ebook switch 2774 - Lid switch 2775 - AC adapter status updates 2776 - Battery status updates 2777 2778config OLPC_XO15_SCI 2779 bool "OLPC XO-1.5 SCI extras" 2780 depends on OLPC && ACPI 2781 select POWER_SUPPLY 2782 help 2783 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2784 - EC-driven system wakeups 2785 - AC adapter status updates 2786 - Battery status updates 2787 2788config ALIX 2789 bool "PCEngines ALIX System Support (LED setup)" 2790 select GPIOLIB 2791 help 2792 This option enables system support for the PCEngines ALIX. 2793 At present this just sets up LEDs for GPIO control on 2794 ALIX2/3/6 boards. However, other system specific setup should 2795 get added here. 2796 2797 Note: You must still enable the drivers for GPIO and LED support 2798 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2799 2800 Note: You have to set alix.force=1 for boards with Award BIOS. 2801 2802config NET5501 2803 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2804 select GPIOLIB 2805 help 2806 This option enables system support for the Soekris Engineering net5501. 2807 2808config GEOS 2809 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2810 select GPIOLIB 2811 depends on DMI 2812 help 2813 This option enables system support for the Traverse Technologies GEOS. 2814 2815config TS5500 2816 bool "Technologic Systems TS-5500 platform support" 2817 depends on MELAN 2818 select CHECK_SIGNATURE 2819 select NEW_LEDS 2820 select LEDS_CLASS 2821 help 2822 This option enables system support for the Technologic Systems TS-5500. 2823 2824endif # X86_32 2825 2826config AMD_NB 2827 def_bool y 2828 depends on CPU_SUP_AMD && PCI 2829 2830config X86_SYSFB 2831 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2832 help 2833 Firmwares often provide initial graphics framebuffers so the BIOS, 2834 bootloader or kernel can show basic video-output during boot for 2835 user-guidance and debugging. Historically, x86 used the VESA BIOS 2836 Extensions and EFI-framebuffers for this, which are mostly limited 2837 to x86. 2838 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2839 framebuffers so the new generic system-framebuffer drivers can be 2840 used on x86. If the framebuffer is not compatible with the generic 2841 modes, it is advertised as fallback platform framebuffer so legacy 2842 drivers like efifb, vesafb and uvesafb can pick it up. 2843 If this option is not selected, all system framebuffers are always 2844 marked as fallback platform framebuffers as usual. 2845 2846 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2847 not be able to pick up generic system framebuffers if this option 2848 is selected. You are highly encouraged to enable simplefb as 2849 replacement if you select this option. simplefb can correctly deal 2850 with generic system framebuffers. But you should still keep vesafb 2851 and others enabled as fallback if a system framebuffer is 2852 incompatible with simplefb. 2853 2854 If unsure, say Y. 2855 2856endmenu 2857 2858 2859menu "Binary Emulations" 2860 2861config IA32_EMULATION 2862 bool "IA32 Emulation" 2863 depends on X86_64 2864 select ARCH_WANT_OLD_COMPAT_IPC 2865 select BINFMT_ELF 2866 select COMPAT_BINFMT_ELF 2867 select COMPAT_OLD_SIGACTION 2868 help 2869 Include code to run legacy 32-bit programs under a 2870 64-bit kernel. You should likely turn this on, unless you're 2871 100% sure that you don't have any 32-bit programs left. 2872 2873config IA32_AOUT 2874 tristate "IA32 a.out support" 2875 depends on IA32_EMULATION 2876 depends on BROKEN 2877 help 2878 Support old a.out binaries in the 32bit emulation. 2879 2880config X86_X32 2881 bool "x32 ABI for 64-bit mode" 2882 depends on X86_64 2883 help 2884 Include code to run binaries for the x32 native 32-bit ABI 2885 for 64-bit processors. An x32 process gets access to the 2886 full 64-bit register file and wide data path while leaving 2887 pointers at 32 bits for smaller memory footprint. 2888 2889 You will need a recent binutils (2.22 or later) with 2890 elf32_x86_64 support enabled to compile a kernel with this 2891 option set. 2892 2893config COMPAT_32 2894 def_bool y 2895 depends on IA32_EMULATION || X86_32 2896 select HAVE_UID16 2897 select OLD_SIGSUSPEND3 2898 2899config COMPAT 2900 def_bool y 2901 depends on IA32_EMULATION || X86_X32 2902 2903if COMPAT 2904config COMPAT_FOR_U64_ALIGNMENT 2905 def_bool y 2906 2907config SYSVIPC_COMPAT 2908 def_bool y 2909 depends on SYSVIPC 2910endif 2911 2912endmenu 2913 2914 2915config HAVE_ATOMIC_IOMAP 2916 def_bool y 2917 depends on X86_32 2918 2919source "drivers/firmware/Kconfig" 2920 2921source "arch/x86/kvm/Kconfig" 2922 2923source "arch/x86/Kconfig.assembler" 2924