1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 ---help--- 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select HAVE_DEBUG_STACKOVERFLOW 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 select GENERIC_VDSO_32 21 22config X86_64 23 def_bool y 24 depends on 64BIT 25 # Options that are inherently 64-bit kernel only: 26 select ARCH_HAS_GIGANTIC_PAGE 27 select ARCH_SUPPORTS_INT128 28 select ARCH_USE_CMPXCHG_LOCKREF 29 select HAVE_ARCH_SOFT_DIRTY 30 select MODULES_USE_ELF_RELA 31 select NEED_DMA_MAP_STATE 32 select SWIOTLB 33 select ARCH_HAS_SYSCALL_WRAPPER 34 35config FORCE_DYNAMIC_FTRACE 36 def_bool y 37 depends on X86_32 38 depends on FUNCTION_TRACER 39 select DYNAMIC_FTRACE 40 help 41 We keep the static function tracing (!DYNAMIC_FTRACE) around 42 in order to test the non static function tracing in the 43 generic code, as other architectures still use it. But we 44 only need to keep it around for x86_64. No need to keep it 45 for x86_32. For x86_32, force DYNAMIC_FTRACE. 46# 47# Arch settings 48# 49# ( Note that options that are marked 'if X86_64' could in principle be 50# ported to 32-bit as well. ) 51# 52config X86 53 def_bool y 54 # 55 # Note: keep this list sorted alphabetically 56 # 57 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 58 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 59 select ARCH_32BIT_OFF_T if X86_32 60 select ARCH_CLOCKSOURCE_DATA 61 select ARCH_CLOCKSOURCE_INIT 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 63 select ARCH_HAS_DEBUG_VIRTUAL 64 select ARCH_HAS_DEVMEM_IS_ALLOWED 65 select ARCH_HAS_ELF_RANDOMIZE 66 select ARCH_HAS_FAST_MULTIPLIER 67 select ARCH_HAS_FILTER_PGPROT 68 select ARCH_HAS_FORTIFY_SOURCE 69 select ARCH_HAS_GCOV_PROFILE_ALL 70 select ARCH_HAS_KCOV if X86_64 71 select ARCH_HAS_MEMBARRIER_SYNC_CORE 72 select ARCH_HAS_PMEM_API if X86_64 73 select ARCH_HAS_PTE_SPECIAL 74 select ARCH_HAS_REFCOUNT 75 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 76 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 77 select ARCH_HAS_SET_MEMORY 78 select ARCH_HAS_SET_DIRECT_MAP 79 select ARCH_HAS_STRICT_KERNEL_RWX 80 select ARCH_HAS_STRICT_MODULE_RWX 81 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 82 select ARCH_HAS_UBSAN_SANITIZE_ALL 83 select ARCH_HAS_ZONE_DEVICE if X86_64 84 select ARCH_HAVE_NMI_SAFE_CMPXCHG 85 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 86 select ARCH_MIGHT_HAVE_PC_PARPORT 87 select ARCH_MIGHT_HAVE_PC_SERIO 88 select ARCH_STACKWALK 89 select ARCH_SUPPORTS_ACPI 90 select ARCH_SUPPORTS_ATOMIC_RMW 91 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 92 select ARCH_USE_BUILTIN_BSWAP 93 select ARCH_USE_QUEUED_RWLOCKS 94 select ARCH_USE_QUEUED_SPINLOCKS 95 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 96 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 97 select ARCH_WANTS_THP_SWAP if X86_64 98 select BUILDTIME_EXTABLE_SORT 99 select CLKEVT_I8253 100 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 101 select CLOCKSOURCE_WATCHDOG 102 select DCACHE_WORD_ACCESS 103 select EDAC_ATOMIC_SCRUB 104 select EDAC_SUPPORT 105 select GENERIC_CLOCKEVENTS 106 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 107 select GENERIC_CLOCKEVENTS_MIN_ADJUST 108 select GENERIC_CMOS_UPDATE 109 select GENERIC_CPU_AUTOPROBE 110 select GENERIC_CPU_VULNERABILITIES 111 select GENERIC_EARLY_IOREMAP 112 select GENERIC_FIND_FIRST_BIT 113 select GENERIC_IOMAP 114 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 115 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 116 select GENERIC_IRQ_MIGRATION if SMP 117 select GENERIC_IRQ_PROBE 118 select GENERIC_IRQ_RESERVATION_MODE 119 select GENERIC_IRQ_SHOW 120 select GENERIC_PENDING_IRQ if SMP 121 select GENERIC_SMP_IDLE_THREAD 122 select GENERIC_STRNCPY_FROM_USER 123 select GENERIC_STRNLEN_USER 124 select GENERIC_TIME_VSYSCALL 125 select GENERIC_GETTIMEOFDAY 126 select GUP_GET_PTE_LOW_HIGH if X86_PAE 127 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 128 select HAVE_ACPI_APEI if ACPI 129 select HAVE_ACPI_APEI_NMI if ACPI 130 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 131 select HAVE_ARCH_AUDITSYSCALL 132 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 133 select HAVE_ARCH_JUMP_LABEL 134 select HAVE_ARCH_JUMP_LABEL_RELATIVE 135 select HAVE_ARCH_KASAN if X86_64 136 select HAVE_ARCH_KGDB 137 select HAVE_ARCH_MMAP_RND_BITS if MMU 138 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 139 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 140 select HAVE_ARCH_PREL32_RELOCATIONS 141 select HAVE_ARCH_SECCOMP_FILTER 142 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 143 select HAVE_ARCH_STACKLEAK 144 select HAVE_ARCH_TRACEHOOK 145 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 146 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 147 select HAVE_ARCH_VMAP_STACK if X86_64 148 select HAVE_ARCH_WITHIN_STACK_FRAMES 149 select HAVE_CMPXCHG_DOUBLE 150 select HAVE_CMPXCHG_LOCAL 151 select HAVE_CONTEXT_TRACKING if X86_64 152 select HAVE_COPY_THREAD_TLS 153 select HAVE_C_RECORDMCOUNT 154 select HAVE_DEBUG_KMEMLEAK 155 select HAVE_DMA_CONTIGUOUS 156 select HAVE_DYNAMIC_FTRACE 157 select HAVE_DYNAMIC_FTRACE_WITH_REGS 158 select HAVE_EBPF_JIT 159 select HAVE_EFFICIENT_UNALIGNED_ACCESS 160 select HAVE_EISA 161 select HAVE_EXIT_THREAD 162 select HAVE_FAST_GUP 163 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 164 select HAVE_FTRACE_MCOUNT_RECORD 165 select HAVE_FUNCTION_GRAPH_TRACER 166 select HAVE_FUNCTION_TRACER 167 select HAVE_GCC_PLUGINS 168 select HAVE_HW_BREAKPOINT 169 select HAVE_IDE 170 select HAVE_IOREMAP_PROT 171 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 172 select HAVE_IRQ_TIME_ACCOUNTING 173 select HAVE_KERNEL_BZIP2 174 select HAVE_KERNEL_GZIP 175 select HAVE_KERNEL_LZ4 176 select HAVE_KERNEL_LZMA 177 select HAVE_KERNEL_LZO 178 select HAVE_KERNEL_XZ 179 select HAVE_KPROBES 180 select HAVE_KPROBES_ON_FTRACE 181 select HAVE_FUNCTION_ERROR_INJECTION 182 select HAVE_KRETPROBES 183 select HAVE_KVM 184 select HAVE_LIVEPATCH if X86_64 185 select HAVE_MEMBLOCK_NODE_MAP 186 select HAVE_MIXED_BREAKPOINTS_REGS 187 select HAVE_MOD_ARCH_SPECIFIC 188 select HAVE_MOVE_PMD 189 select HAVE_NMI 190 select HAVE_OPROFILE 191 select HAVE_OPTPROBES 192 select HAVE_PCSPKR_PLATFORM 193 select HAVE_PERF_EVENTS 194 select HAVE_PERF_EVENTS_NMI 195 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 196 select HAVE_PCI 197 select HAVE_PERF_REGS 198 select HAVE_PERF_USER_STACK_DUMP 199 select HAVE_RCU_TABLE_FREE if PARAVIRT 200 select HAVE_REGS_AND_STACK_ACCESS_API 201 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 202 select HAVE_FUNCTION_ARG_ACCESS_API 203 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 204 select HAVE_STACK_VALIDATION if X86_64 205 select HAVE_RSEQ 206 select HAVE_SYSCALL_TRACEPOINTS 207 select HAVE_UNSTABLE_SCHED_CLOCK 208 select HAVE_USER_RETURN_NOTIFIER 209 select HAVE_GENERIC_VDSO 210 select HOTPLUG_SMT if SMP 211 select IRQ_FORCED_THREADING 212 select NEED_SG_DMA_LENGTH 213 select PCI_DOMAINS if PCI 214 select PCI_LOCKLESS_CONFIG if PCI 215 select PERF_EVENTS 216 select RTC_LIB 217 select RTC_MC146818_LIB 218 select SPARSE_IRQ 219 select SRCU 220 select SYSCTL_EXCEPTION_TRACE 221 select THREAD_INFO_IN_TASK 222 select USER_STACKTRACE_SUPPORT 223 select VIRT_TO_BUS 224 select X86_FEATURE_NAMES if PROC_FS 225 select PROC_PID_ARCH_STATUS if PROC_FS 226 227config INSTRUCTION_DECODER 228 def_bool y 229 depends on KPROBES || PERF_EVENTS || UPROBES 230 231config OUTPUT_FORMAT 232 string 233 default "elf32-i386" if X86_32 234 default "elf64-x86-64" if X86_64 235 236config ARCH_DEFCONFIG 237 string 238 default "arch/x86/configs/i386_defconfig" if X86_32 239 default "arch/x86/configs/x86_64_defconfig" if X86_64 240 241config LOCKDEP_SUPPORT 242 def_bool y 243 244config STACKTRACE_SUPPORT 245 def_bool y 246 247config MMU 248 def_bool y 249 250config ARCH_MMAP_RND_BITS_MIN 251 default 28 if 64BIT 252 default 8 253 254config ARCH_MMAP_RND_BITS_MAX 255 default 32 if 64BIT 256 default 16 257 258config ARCH_MMAP_RND_COMPAT_BITS_MIN 259 default 8 260 261config ARCH_MMAP_RND_COMPAT_BITS_MAX 262 default 16 263 264config SBUS 265 bool 266 267config GENERIC_ISA_DMA 268 def_bool y 269 depends on ISA_DMA_API 270 271config GENERIC_BUG 272 def_bool y 273 depends on BUG 274 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 275 276config GENERIC_BUG_RELATIVE_POINTERS 277 bool 278 279config ARCH_MAY_HAVE_PC_FDC 280 def_bool y 281 depends on ISA_DMA_API 282 283config GENERIC_CALIBRATE_DELAY 284 def_bool y 285 286config ARCH_HAS_CPU_RELAX 287 def_bool y 288 289config ARCH_HAS_CACHE_LINE_SIZE 290 def_bool y 291 292config ARCH_HAS_FILTER_PGPROT 293 def_bool y 294 295config HAVE_SETUP_PER_CPU_AREA 296 def_bool y 297 298config NEED_PER_CPU_EMBED_FIRST_CHUNK 299 def_bool y 300 301config NEED_PER_CPU_PAGE_FIRST_CHUNK 302 def_bool y 303 304config ARCH_HIBERNATION_POSSIBLE 305 def_bool y 306 307config ARCH_SUSPEND_POSSIBLE 308 def_bool y 309 310config ARCH_WANT_HUGE_PMD_SHARE 311 def_bool y 312 313config ARCH_WANT_GENERAL_HUGETLB 314 def_bool y 315 316config ZONE_DMA32 317 def_bool y if X86_64 318 319config AUDIT_ARCH 320 def_bool y if X86_64 321 322config ARCH_SUPPORTS_DEBUG_PAGEALLOC 323 def_bool y 324 325config KASAN_SHADOW_OFFSET 326 hex 327 depends on KASAN 328 default 0xdffffc0000000000 329 330config HAVE_INTEL_TXT 331 def_bool y 332 depends on INTEL_IOMMU && ACPI 333 334config X86_32_SMP 335 def_bool y 336 depends on X86_32 && SMP 337 338config X86_64_SMP 339 def_bool y 340 depends on X86_64 && SMP 341 342config X86_32_LAZY_GS 343 def_bool y 344 depends on X86_32 && !STACKPROTECTOR 345 346config ARCH_SUPPORTS_UPROBES 347 def_bool y 348 349config FIX_EARLYCON_MEM 350 def_bool y 351 352config DYNAMIC_PHYSICAL_MASK 353 bool 354 355config PGTABLE_LEVELS 356 int 357 default 5 if X86_5LEVEL 358 default 4 if X86_64 359 default 3 if X86_PAE 360 default 2 361 362config CC_HAS_SANE_STACKPROTECTOR 363 bool 364 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 365 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 366 help 367 We have to make sure stack protector is unconditionally disabled if 368 the compiler produces broken code. 369 370menu "Processor type and features" 371 372config ZONE_DMA 373 bool "DMA memory allocation support" if EXPERT 374 default y 375 help 376 DMA memory allocation support allows devices with less than 32-bit 377 addressing to allocate within the first 16MB of address space. 378 Disable if no such devices will be used. 379 380 If unsure, say Y. 381 382config SMP 383 bool "Symmetric multi-processing support" 384 ---help--- 385 This enables support for systems with more than one CPU. If you have 386 a system with only one CPU, say N. If you have a system with more 387 than one CPU, say Y. 388 389 If you say N here, the kernel will run on uni- and multiprocessor 390 machines, but will use only one CPU of a multiprocessor machine. If 391 you say Y here, the kernel will run on many, but not all, 392 uniprocessor machines. On a uniprocessor machine, the kernel 393 will run faster if you say N here. 394 395 Note that if you say Y here and choose architecture "586" or 396 "Pentium" under "Processor family", the kernel will not work on 486 397 architectures. Similarly, multiprocessor kernels for the "PPro" 398 architecture may not work on all Pentium based boards. 399 400 People using multiprocessor machines who say Y here should also say 401 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 402 Management" code will be disabled if you say Y here. 403 404 See also <file:Documentation/x86/i386/IO-APIC.rst>, 405 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 406 <http://www.tldp.org/docs.html#howto>. 407 408 If you don't know what to do here, say N. 409 410config X86_FEATURE_NAMES 411 bool "Processor feature human-readable names" if EMBEDDED 412 default y 413 ---help--- 414 This option compiles in a table of x86 feature bits and corresponding 415 names. This is required to support /proc/cpuinfo and a few kernel 416 messages. You can disable this to save space, at the expense of 417 making those few kernel messages show numeric feature bits instead. 418 419 If in doubt, say Y. 420 421config X86_X2APIC 422 bool "Support x2apic" 423 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 424 ---help--- 425 This enables x2apic support on CPUs that have this feature. 426 427 This allows 32-bit apic IDs (so it can support very large systems), 428 and accesses the local apic via MSRs not via mmio. 429 430 If you don't know what to do here, say N. 431 432config X86_MPPARSE 433 bool "Enable MPS table" if ACPI || SFI 434 default y 435 depends on X86_LOCAL_APIC 436 ---help--- 437 For old smp systems that do not have proper acpi support. Newer systems 438 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 439 440config GOLDFISH 441 def_bool y 442 depends on X86_GOLDFISH 443 444config RETPOLINE 445 bool "Avoid speculative indirect branches in kernel" 446 default y 447 select STACK_VALIDATION if HAVE_STACK_VALIDATION 448 help 449 Compile kernel with the retpoline compiler options to guard against 450 kernel-to-user data leaks by avoiding speculative indirect 451 branches. Requires a compiler with -mindirect-branch=thunk-extern 452 support for full protection. The kernel may run slower. 453 454config X86_CPU_RESCTRL 455 bool "x86 CPU resource control support" 456 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 457 select KERNFS 458 help 459 Enable x86 CPU resource control support. 460 461 Provide support for the allocation and monitoring of system resources 462 usage by the CPU. 463 464 Intel calls this Intel Resource Director Technology 465 (Intel(R) RDT). More information about RDT can be found in the 466 Intel x86 Architecture Software Developer Manual. 467 468 AMD calls this AMD Platform Quality of Service (AMD QoS). 469 More information about AMD QoS can be found in the AMD64 Technology 470 Platform Quality of Service Extensions manual. 471 472 Say N if unsure. 473 474if X86_32 475config X86_BIGSMP 476 bool "Support for big SMP systems with more than 8 CPUs" 477 depends on SMP 478 ---help--- 479 This option is needed for the systems that have more than 8 CPUs 480 481config X86_EXTENDED_PLATFORM 482 bool "Support for extended (non-PC) x86 platforms" 483 default y 484 ---help--- 485 If you disable this option then the kernel will only support 486 standard PC platforms. (which covers the vast majority of 487 systems out there.) 488 489 If you enable this option then you'll be able to select support 490 for the following (non-PC) 32 bit x86 platforms: 491 Goldfish (Android emulator) 492 AMD Elan 493 RDC R-321x SoC 494 SGI 320/540 (Visual Workstation) 495 STA2X11-based (e.g. Northville) 496 Moorestown MID devices 497 498 If you have one of these systems, or if you want to build a 499 generic distribution kernel, say Y here - otherwise say N. 500endif 501 502if X86_64 503config X86_EXTENDED_PLATFORM 504 bool "Support for extended (non-PC) x86 platforms" 505 default y 506 ---help--- 507 If you disable this option then the kernel will only support 508 standard PC platforms. (which covers the vast majority of 509 systems out there.) 510 511 If you enable this option then you'll be able to select support 512 for the following (non-PC) 64 bit x86 platforms: 513 Numascale NumaChip 514 ScaleMP vSMP 515 SGI Ultraviolet 516 517 If you have one of these systems, or if you want to build a 518 generic distribution kernel, say Y here - otherwise say N. 519endif 520# This is an alphabetically sorted list of 64 bit extended platforms 521# Please maintain the alphabetic order if and when there are additions 522config X86_NUMACHIP 523 bool "Numascale NumaChip" 524 depends on X86_64 525 depends on X86_EXTENDED_PLATFORM 526 depends on NUMA 527 depends on SMP 528 depends on X86_X2APIC 529 depends on PCI_MMCONFIG 530 ---help--- 531 Adds support for Numascale NumaChip large-SMP systems. Needed to 532 enable more than ~168 cores. 533 If you don't have one of these, you should say N here. 534 535config X86_VSMP 536 bool "ScaleMP vSMP" 537 select HYPERVISOR_GUEST 538 select PARAVIRT 539 depends on X86_64 && PCI 540 depends on X86_EXTENDED_PLATFORM 541 depends on SMP 542 ---help--- 543 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 544 supposed to run on these EM64T-based machines. Only choose this option 545 if you have one of these machines. 546 547config X86_UV 548 bool "SGI Ultraviolet" 549 depends on X86_64 550 depends on X86_EXTENDED_PLATFORM 551 depends on NUMA 552 depends on EFI 553 depends on X86_X2APIC 554 depends on PCI 555 ---help--- 556 This option is needed in order to support SGI Ultraviolet systems. 557 If you don't have one of these, you should say N here. 558 559# Following is an alphabetically sorted list of 32 bit extended platforms 560# Please maintain the alphabetic order if and when there are additions 561 562config X86_GOLDFISH 563 bool "Goldfish (Virtual Platform)" 564 depends on X86_EXTENDED_PLATFORM 565 ---help--- 566 Enable support for the Goldfish virtual platform used primarily 567 for Android development. Unless you are building for the Android 568 Goldfish emulator say N here. 569 570config X86_INTEL_CE 571 bool "CE4100 TV platform" 572 depends on PCI 573 depends on PCI_GODIRECT 574 depends on X86_IO_APIC 575 depends on X86_32 576 depends on X86_EXTENDED_PLATFORM 577 select X86_REBOOTFIXUPS 578 select OF 579 select OF_EARLY_FLATTREE 580 ---help--- 581 Select for the Intel CE media processor (CE4100) SOC. 582 This option compiles in support for the CE4100 SOC for settop 583 boxes and media devices. 584 585config X86_INTEL_MID 586 bool "Intel MID platform support" 587 depends on X86_EXTENDED_PLATFORM 588 depends on X86_PLATFORM_DEVICES 589 depends on PCI 590 depends on X86_64 || (PCI_GOANY && X86_32) 591 depends on X86_IO_APIC 592 select SFI 593 select I2C 594 select DW_APB_TIMER 595 select APB_TIMER 596 select INTEL_SCU_IPC 597 select MFD_INTEL_MSIC 598 ---help--- 599 Select to build a kernel capable of supporting Intel MID (Mobile 600 Internet Device) platform systems which do not have the PCI legacy 601 interfaces. If you are building for a PC class system say N here. 602 603 Intel MID platforms are based on an Intel processor and chipset which 604 consume less power than most of the x86 derivatives. 605 606config X86_INTEL_QUARK 607 bool "Intel Quark platform support" 608 depends on X86_32 609 depends on X86_EXTENDED_PLATFORM 610 depends on X86_PLATFORM_DEVICES 611 depends on X86_TSC 612 depends on PCI 613 depends on PCI_GOANY 614 depends on X86_IO_APIC 615 select IOSF_MBI 616 select INTEL_IMR 617 select COMMON_CLK 618 ---help--- 619 Select to include support for Quark X1000 SoC. 620 Say Y here if you have a Quark based system such as the Arduino 621 compatible Intel Galileo. 622 623config X86_INTEL_LPSS 624 bool "Intel Low Power Subsystem Support" 625 depends on X86 && ACPI && PCI 626 select COMMON_CLK 627 select PINCTRL 628 select IOSF_MBI 629 ---help--- 630 Select to build support for Intel Low Power Subsystem such as 631 found on Intel Lynxpoint PCH. Selecting this option enables 632 things like clock tree (common clock framework) and pincontrol 633 which are needed by the LPSS peripheral drivers. 634 635config X86_AMD_PLATFORM_DEVICE 636 bool "AMD ACPI2Platform devices support" 637 depends on ACPI 638 select COMMON_CLK 639 select PINCTRL 640 ---help--- 641 Select to interpret AMD specific ACPI device to platform device 642 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 643 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 644 implemented under PINCTRL subsystem. 645 646config IOSF_MBI 647 tristate "Intel SoC IOSF Sideband support for SoC platforms" 648 depends on PCI 649 ---help--- 650 This option enables sideband register access support for Intel SoC 651 platforms. On these platforms the IOSF sideband is used in lieu of 652 MSR's for some register accesses, mostly but not limited to thermal 653 and power. Drivers may query the availability of this device to 654 determine if they need the sideband in order to work on these 655 platforms. The sideband is available on the following SoC products. 656 This list is not meant to be exclusive. 657 - BayTrail 658 - Braswell 659 - Quark 660 661 You should say Y if you are running a kernel on one of these SoC's. 662 663config IOSF_MBI_DEBUG 664 bool "Enable IOSF sideband access through debugfs" 665 depends on IOSF_MBI && DEBUG_FS 666 ---help--- 667 Select this option to expose the IOSF sideband access registers (MCR, 668 MDR, MCRX) through debugfs to write and read register information from 669 different units on the SoC. This is most useful for obtaining device 670 state information for debug and analysis. As this is a general access 671 mechanism, users of this option would have specific knowledge of the 672 device they want to access. 673 674 If you don't require the option or are in doubt, say N. 675 676config X86_RDC321X 677 bool "RDC R-321x SoC" 678 depends on X86_32 679 depends on X86_EXTENDED_PLATFORM 680 select M486 681 select X86_REBOOTFIXUPS 682 ---help--- 683 This option is needed for RDC R-321x system-on-chip, also known 684 as R-8610-(G). 685 If you don't have one of these chips, you should say N here. 686 687config X86_32_NON_STANDARD 688 bool "Support non-standard 32-bit SMP architectures" 689 depends on X86_32 && SMP 690 depends on X86_EXTENDED_PLATFORM 691 ---help--- 692 This option compiles in the bigsmp and STA2X11 default 693 subarchitectures. It is intended for a generic binary 694 kernel. If you select them all, kernel will probe it one by 695 one and will fallback to default. 696 697# Alphabetically sorted list of Non standard 32 bit platforms 698 699config X86_SUPPORTS_MEMORY_FAILURE 700 def_bool y 701 # MCE code calls memory_failure(): 702 depends on X86_MCE 703 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 704 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 705 depends on X86_64 || !SPARSEMEM 706 select ARCH_SUPPORTS_MEMORY_FAILURE 707 708config STA2X11 709 bool "STA2X11 Companion Chip Support" 710 depends on X86_32_NON_STANDARD && PCI 711 select ARCH_HAS_PHYS_TO_DMA 712 select SWIOTLB 713 select MFD_STA2X11 714 select GPIOLIB 715 ---help--- 716 This adds support for boards based on the STA2X11 IO-Hub, 717 a.k.a. "ConneXt". The chip is used in place of the standard 718 PC chipset, so all "standard" peripherals are missing. If this 719 option is selected the kernel will still be able to boot on 720 standard PC machines. 721 722config X86_32_IRIS 723 tristate "Eurobraille/Iris poweroff module" 724 depends on X86_32 725 ---help--- 726 The Iris machines from EuroBraille do not have APM or ACPI support 727 to shut themselves down properly. A special I/O sequence is 728 needed to do so, which is what this module does at 729 kernel shutdown. 730 731 This is only for Iris machines from EuroBraille. 732 733 If unused, say N. 734 735config SCHED_OMIT_FRAME_POINTER 736 def_bool y 737 prompt "Single-depth WCHAN output" 738 depends on X86 739 ---help--- 740 Calculate simpler /proc/<PID>/wchan values. If this option 741 is disabled then wchan values will recurse back to the 742 caller function. This provides more accurate wchan values, 743 at the expense of slightly more scheduling overhead. 744 745 If in doubt, say "Y". 746 747menuconfig HYPERVISOR_GUEST 748 bool "Linux guest support" 749 ---help--- 750 Say Y here to enable options for running Linux under various hyper- 751 visors. This option enables basic hypervisor detection and platform 752 setup. 753 754 If you say N, all options in this submenu will be skipped and 755 disabled, and Linux guest support won't be built in. 756 757if HYPERVISOR_GUEST 758 759config PARAVIRT 760 bool "Enable paravirtualization code" 761 ---help--- 762 This changes the kernel so it can modify itself when it is run 763 under a hypervisor, potentially improving performance significantly 764 over full virtualization. However, when run without a hypervisor 765 the kernel is theoretically slower and slightly larger. 766 767config PARAVIRT_XXL 768 bool 769 770config PARAVIRT_DEBUG 771 bool "paravirt-ops debugging" 772 depends on PARAVIRT && DEBUG_KERNEL 773 ---help--- 774 Enable to debug paravirt_ops internals. Specifically, BUG if 775 a paravirt_op is missing when it is called. 776 777config PARAVIRT_SPINLOCKS 778 bool "Paravirtualization layer for spinlocks" 779 depends on PARAVIRT && SMP 780 ---help--- 781 Paravirtualized spinlocks allow a pvops backend to replace the 782 spinlock implementation with something virtualization-friendly 783 (for example, block the virtual CPU rather than spinning). 784 785 It has a minimal impact on native kernels and gives a nice performance 786 benefit on paravirtualized KVM / Xen kernels. 787 788 If you are unsure how to answer this question, answer Y. 789 790config X86_HV_CALLBACK_VECTOR 791 def_bool n 792 793source "arch/x86/xen/Kconfig" 794 795config KVM_GUEST 796 bool "KVM Guest support (including kvmclock)" 797 depends on PARAVIRT 798 select PARAVIRT_CLOCK 799 default y 800 ---help--- 801 This option enables various optimizations for running under the KVM 802 hypervisor. It includes a paravirtualized clock, so that instead 803 of relying on a PIT (or probably other) emulation by the 804 underlying device model, the host provides the guest with 805 timing infrastructure such as time of day, and system time 806 807config PVH 808 bool "Support for running PVH guests" 809 ---help--- 810 This option enables the PVH entry point for guest virtual machines 811 as specified in the x86/HVM direct boot ABI. 812 813config KVM_DEBUG_FS 814 bool "Enable debug information for KVM Guests in debugfs" 815 depends on KVM_GUEST && DEBUG_FS 816 ---help--- 817 This option enables collection of various statistics for KVM guest. 818 Statistics are displayed in debugfs filesystem. Enabling this option 819 may incur significant overhead. 820 821config PARAVIRT_TIME_ACCOUNTING 822 bool "Paravirtual steal time accounting" 823 depends on PARAVIRT 824 ---help--- 825 Select this option to enable fine granularity task steal time 826 accounting. Time spent executing other tasks in parallel with 827 the current vCPU is discounted from the vCPU power. To account for 828 that, there can be a small performance impact. 829 830 If in doubt, say N here. 831 832config PARAVIRT_CLOCK 833 bool 834 835config JAILHOUSE_GUEST 836 bool "Jailhouse non-root cell support" 837 depends on X86_64 && PCI 838 select X86_PM_TIMER 839 ---help--- 840 This option allows to run Linux as guest in a Jailhouse non-root 841 cell. You can leave this option disabled if you only want to start 842 Jailhouse and run Linux afterwards in the root cell. 843 844config ACRN_GUEST 845 bool "ACRN Guest support" 846 depends on X86_64 847 select X86_HV_CALLBACK_VECTOR 848 help 849 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 850 a flexible, lightweight reference open-source hypervisor, built with 851 real-time and safety-criticality in mind. It is built for embedded 852 IOT with small footprint and real-time features. More details can be 853 found in https://projectacrn.org/. 854 855endif #HYPERVISOR_GUEST 856 857source "arch/x86/Kconfig.cpu" 858 859config HPET_TIMER 860 def_bool X86_64 861 prompt "HPET Timer Support" if X86_32 862 ---help--- 863 Use the IA-PC HPET (High Precision Event Timer) to manage 864 time in preference to the PIT and RTC, if a HPET is 865 present. 866 HPET is the next generation timer replacing legacy 8254s. 867 The HPET provides a stable time base on SMP 868 systems, unlike the TSC, but it is more expensive to access, 869 as it is off-chip. The interface used is documented 870 in the HPET spec, revision 1. 871 872 You can safely choose Y here. However, HPET will only be 873 activated if the platform and the BIOS support this feature. 874 Otherwise the 8254 will be used for timing services. 875 876 Choose N to continue using the legacy 8254 timer. 877 878config HPET_EMULATE_RTC 879 def_bool y 880 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 881 882config APB_TIMER 883 def_bool y if X86_INTEL_MID 884 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 885 select DW_APB_TIMER 886 depends on X86_INTEL_MID && SFI 887 help 888 APB timer is the replacement for 8254, HPET on X86 MID platforms. 889 The APBT provides a stable time base on SMP 890 systems, unlike the TSC, but it is more expensive to access, 891 as it is off-chip. APB timers are always running regardless of CPU 892 C states, they are used as per CPU clockevent device when possible. 893 894# Mark as expert because too many people got it wrong. 895# The code disables itself when not needed. 896config DMI 897 default y 898 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 899 bool "Enable DMI scanning" if EXPERT 900 ---help--- 901 Enabled scanning of DMI to identify machine quirks. Say Y 902 here unless you have verified that your setup is not 903 affected by entries in the DMI blacklist. Required by PNP 904 BIOS code. 905 906config GART_IOMMU 907 bool "Old AMD GART IOMMU support" 908 select IOMMU_HELPER 909 select SWIOTLB 910 depends on X86_64 && PCI && AMD_NB 911 ---help--- 912 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 913 GART based hardware IOMMUs. 914 915 The GART supports full DMA access for devices with 32-bit access 916 limitations, on systems with more than 3 GB. This is usually needed 917 for USB, sound, many IDE/SATA chipsets and some other devices. 918 919 Newer systems typically have a modern AMD IOMMU, supported via 920 the CONFIG_AMD_IOMMU=y config option. 921 922 In normal configurations this driver is only active when needed: 923 there's more than 3 GB of memory and the system contains a 924 32-bit limited device. 925 926 If unsure, say Y. 927 928config CALGARY_IOMMU 929 bool "IBM Calgary IOMMU support" 930 select IOMMU_HELPER 931 select SWIOTLB 932 depends on X86_64 && PCI 933 ---help--- 934 Support for hardware IOMMUs in IBM's xSeries x366 and x460 935 systems. Needed to run systems with more than 3GB of memory 936 properly with 32-bit PCI devices that do not support DAC 937 (Double Address Cycle). Calgary also supports bus level 938 isolation, where all DMAs pass through the IOMMU. This 939 prevents them from going anywhere except their intended 940 destination. This catches hard-to-find kernel bugs and 941 mis-behaving drivers and devices that do not use the DMA-API 942 properly to set up their DMA buffers. The IOMMU can be 943 turned off at boot time with the iommu=off parameter. 944 Normally the kernel will make the right choice by itself. 945 If unsure, say Y. 946 947config CALGARY_IOMMU_ENABLED_BY_DEFAULT 948 def_bool y 949 prompt "Should Calgary be enabled by default?" 950 depends on CALGARY_IOMMU 951 ---help--- 952 Should Calgary be enabled by default? if you choose 'y', Calgary 953 will be used (if it exists). If you choose 'n', Calgary will not be 954 used even if it exists. If you choose 'n' and would like to use 955 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 956 If unsure, say Y. 957 958config MAXSMP 959 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 960 depends on X86_64 && SMP && DEBUG_KERNEL 961 select CPUMASK_OFFSTACK 962 ---help--- 963 Enable maximum number of CPUS and NUMA Nodes for this architecture. 964 If unsure, say N. 965 966# 967# The maximum number of CPUs supported: 968# 969# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 970# and which can be configured interactively in the 971# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 972# 973# The ranges are different on 32-bit and 64-bit kernels, depending on 974# hardware capabilities and scalability features of the kernel. 975# 976# ( If MAXSMP is enabled we just use the highest possible value and disable 977# interactive configuration. ) 978# 979 980config NR_CPUS_RANGE_BEGIN 981 int 982 default NR_CPUS_RANGE_END if MAXSMP 983 default 1 if !SMP 984 default 2 985 986config NR_CPUS_RANGE_END 987 int 988 depends on X86_32 989 default 64 if SMP && X86_BIGSMP 990 default 8 if SMP && !X86_BIGSMP 991 default 1 if !SMP 992 993config NR_CPUS_RANGE_END 994 int 995 depends on X86_64 996 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 997 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 998 default 1 if !SMP 999 1000config NR_CPUS_DEFAULT 1001 int 1002 depends on X86_32 1003 default 32 if X86_BIGSMP 1004 default 8 if SMP 1005 default 1 if !SMP 1006 1007config NR_CPUS_DEFAULT 1008 int 1009 depends on X86_64 1010 default 8192 if MAXSMP 1011 default 64 if SMP 1012 default 1 if !SMP 1013 1014config NR_CPUS 1015 int "Maximum number of CPUs" if SMP && !MAXSMP 1016 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 1017 default NR_CPUS_DEFAULT 1018 ---help--- 1019 This allows you to specify the maximum number of CPUs which this 1020 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1021 supported value is 8192, otherwise the maximum value is 512. The 1022 minimum value which makes sense is 2. 1023 1024 This is purely to save memory: each supported CPU adds about 8KB 1025 to the kernel image. 1026 1027config SCHED_SMT 1028 def_bool y if SMP 1029 1030config SCHED_MC 1031 def_bool y 1032 prompt "Multi-core scheduler support" 1033 depends on SMP 1034 ---help--- 1035 Multi-core scheduler support improves the CPU scheduler's decision 1036 making when dealing with multi-core CPU chips at a cost of slightly 1037 increased overhead in some places. If unsure say N here. 1038 1039config SCHED_MC_PRIO 1040 bool "CPU core priorities scheduler support" 1041 depends on SCHED_MC && CPU_SUP_INTEL 1042 select X86_INTEL_PSTATE 1043 select CPU_FREQ 1044 default y 1045 ---help--- 1046 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1047 core ordering determined at manufacturing time, which allows 1048 certain cores to reach higher turbo frequencies (when running 1049 single threaded workloads) than others. 1050 1051 Enabling this kernel feature teaches the scheduler about 1052 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1053 scheduler's CPU selection logic accordingly, so that higher 1054 overall system performance can be achieved. 1055 1056 This feature will have no effect on CPUs without this feature. 1057 1058 If unsure say Y here. 1059 1060config UP_LATE_INIT 1061 def_bool y 1062 depends on !SMP && X86_LOCAL_APIC 1063 1064config X86_UP_APIC 1065 bool "Local APIC support on uniprocessors" if !PCI_MSI 1066 default PCI_MSI 1067 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1068 ---help--- 1069 A local APIC (Advanced Programmable Interrupt Controller) is an 1070 integrated interrupt controller in the CPU. If you have a single-CPU 1071 system which has a processor with a local APIC, you can say Y here to 1072 enable and use it. If you say Y here even though your machine doesn't 1073 have a local APIC, then the kernel will still run with no slowdown at 1074 all. The local APIC supports CPU-generated self-interrupts (timer, 1075 performance counters), and the NMI watchdog which detects hard 1076 lockups. 1077 1078config X86_UP_IOAPIC 1079 bool "IO-APIC support on uniprocessors" 1080 depends on X86_UP_APIC 1081 ---help--- 1082 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1083 SMP-capable replacement for PC-style interrupt controllers. Most 1084 SMP systems and many recent uniprocessor systems have one. 1085 1086 If you have a single-CPU system with an IO-APIC, you can say Y here 1087 to use it. If you say Y here even though your machine doesn't have 1088 an IO-APIC, then the kernel will still run with no slowdown at all. 1089 1090config X86_LOCAL_APIC 1091 def_bool y 1092 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1093 select IRQ_DOMAIN_HIERARCHY 1094 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1095 1096config X86_IO_APIC 1097 def_bool y 1098 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1099 1100config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1101 bool "Reroute for broken boot IRQs" 1102 depends on X86_IO_APIC 1103 ---help--- 1104 This option enables a workaround that fixes a source of 1105 spurious interrupts. This is recommended when threaded 1106 interrupt handling is used on systems where the generation of 1107 superfluous "boot interrupts" cannot be disabled. 1108 1109 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1110 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1111 kernel does during interrupt handling). On chipsets where this 1112 boot IRQ generation cannot be disabled, this workaround keeps 1113 the original IRQ line masked so that only the equivalent "boot 1114 IRQ" is delivered to the CPUs. The workaround also tells the 1115 kernel to set up the IRQ handler on the boot IRQ line. In this 1116 way only one interrupt is delivered to the kernel. Otherwise 1117 the spurious second interrupt may cause the kernel to bring 1118 down (vital) interrupt lines. 1119 1120 Only affects "broken" chipsets. Interrupt sharing may be 1121 increased on these systems. 1122 1123config X86_MCE 1124 bool "Machine Check / overheating reporting" 1125 select GENERIC_ALLOCATOR 1126 default y 1127 ---help--- 1128 Machine Check support allows the processor to notify the 1129 kernel if it detects a problem (e.g. overheating, data corruption). 1130 The action the kernel takes depends on the severity of the problem, 1131 ranging from warning messages to halting the machine. 1132 1133config X86_MCELOG_LEGACY 1134 bool "Support for deprecated /dev/mcelog character device" 1135 depends on X86_MCE 1136 ---help--- 1137 Enable support for /dev/mcelog which is needed by the old mcelog 1138 userspace logging daemon. Consider switching to the new generation 1139 rasdaemon solution. 1140 1141config X86_MCE_INTEL 1142 def_bool y 1143 prompt "Intel MCE features" 1144 depends on X86_MCE && X86_LOCAL_APIC 1145 ---help--- 1146 Additional support for intel specific MCE features such as 1147 the thermal monitor. 1148 1149config X86_MCE_AMD 1150 def_bool y 1151 prompt "AMD MCE features" 1152 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1153 ---help--- 1154 Additional support for AMD specific MCE features such as 1155 the DRAM Error Threshold. 1156 1157config X86_ANCIENT_MCE 1158 bool "Support for old Pentium 5 / WinChip machine checks" 1159 depends on X86_32 && X86_MCE 1160 ---help--- 1161 Include support for machine check handling on old Pentium 5 or WinChip 1162 systems. These typically need to be enabled explicitly on the command 1163 line. 1164 1165config X86_MCE_THRESHOLD 1166 depends on X86_MCE_AMD || X86_MCE_INTEL 1167 def_bool y 1168 1169config X86_MCE_INJECT 1170 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1171 tristate "Machine check injector support" 1172 ---help--- 1173 Provide support for injecting machine checks for testing purposes. 1174 If you don't know what a machine check is and you don't do kernel 1175 QA it is safe to say n. 1176 1177config X86_THERMAL_VECTOR 1178 def_bool y 1179 depends on X86_MCE_INTEL 1180 1181source "arch/x86/events/Kconfig" 1182 1183config X86_LEGACY_VM86 1184 bool "Legacy VM86 support" 1185 depends on X86_32 1186 ---help--- 1187 This option allows user programs to put the CPU into V8086 1188 mode, which is an 80286-era approximation of 16-bit real mode. 1189 1190 Some very old versions of X and/or vbetool require this option 1191 for user mode setting. Similarly, DOSEMU will use it if 1192 available to accelerate real mode DOS programs. However, any 1193 recent version of DOSEMU, X, or vbetool should be fully 1194 functional even without kernel VM86 support, as they will all 1195 fall back to software emulation. Nevertheless, if you are using 1196 a 16-bit DOS program where 16-bit performance matters, vm86 1197 mode might be faster than emulation and you might want to 1198 enable this option. 1199 1200 Note that any app that works on a 64-bit kernel is unlikely to 1201 need this option, as 64-bit kernels don't, and can't, support 1202 V8086 mode. This option is also unrelated to 16-bit protected 1203 mode and is not needed to run most 16-bit programs under Wine. 1204 1205 Enabling this option increases the complexity of the kernel 1206 and slows down exception handling a tiny bit. 1207 1208 If unsure, say N here. 1209 1210config VM86 1211 bool 1212 default X86_LEGACY_VM86 1213 1214config X86_16BIT 1215 bool "Enable support for 16-bit segments" if EXPERT 1216 default y 1217 depends on MODIFY_LDT_SYSCALL 1218 ---help--- 1219 This option is required by programs like Wine to run 16-bit 1220 protected mode legacy code on x86 processors. Disabling 1221 this option saves about 300 bytes on i386, or around 6K text 1222 plus 16K runtime memory on x86-64, 1223 1224config X86_ESPFIX32 1225 def_bool y 1226 depends on X86_16BIT && X86_32 1227 1228config X86_ESPFIX64 1229 def_bool y 1230 depends on X86_16BIT && X86_64 1231 1232config X86_VSYSCALL_EMULATION 1233 bool "Enable vsyscall emulation" if EXPERT 1234 default y 1235 depends on X86_64 1236 ---help--- 1237 This enables emulation of the legacy vsyscall page. Disabling 1238 it is roughly equivalent to booting with vsyscall=none, except 1239 that it will also disable the helpful warning if a program 1240 tries to use a vsyscall. With this option set to N, offending 1241 programs will just segfault, citing addresses of the form 1242 0xffffffffff600?00. 1243 1244 This option is required by many programs built before 2013, and 1245 care should be used even with newer programs if set to N. 1246 1247 Disabling this option saves about 7K of kernel size and 1248 possibly 4K of additional runtime pagetable memory. 1249 1250config TOSHIBA 1251 tristate "Toshiba Laptop support" 1252 depends on X86_32 1253 ---help--- 1254 This adds a driver to safely access the System Management Mode of 1255 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1256 not work on models with a Phoenix BIOS. The System Management Mode 1257 is used to set the BIOS and power saving options on Toshiba portables. 1258 1259 For information on utilities to make use of this driver see the 1260 Toshiba Linux utilities web site at: 1261 <http://www.buzzard.org.uk/toshiba/>. 1262 1263 Say Y if you intend to run this kernel on a Toshiba portable. 1264 Say N otherwise. 1265 1266config I8K 1267 tristate "Dell i8k legacy laptop support" 1268 select HWMON 1269 select SENSORS_DELL_SMM 1270 ---help--- 1271 This option enables legacy /proc/i8k userspace interface in hwmon 1272 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1273 temperature and allows controlling fan speeds of Dell laptops via 1274 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1275 it reports also power and hotkey status. For fan speed control is 1276 needed userspace package i8kutils. 1277 1278 Say Y if you intend to run this kernel on old Dell laptops or want to 1279 use userspace package i8kutils. 1280 Say N otherwise. 1281 1282config X86_REBOOTFIXUPS 1283 bool "Enable X86 board specific fixups for reboot" 1284 depends on X86_32 1285 ---help--- 1286 This enables chipset and/or board specific fixups to be done 1287 in order to get reboot to work correctly. This is only needed on 1288 some combinations of hardware and BIOS. The symptom, for which 1289 this config is intended, is when reboot ends with a stalled/hung 1290 system. 1291 1292 Currently, the only fixup is for the Geode machines using 1293 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1294 1295 Say Y if you want to enable the fixup. Currently, it's safe to 1296 enable this option even if you don't need it. 1297 Say N otherwise. 1298 1299config MICROCODE 1300 bool "CPU microcode loading support" 1301 default y 1302 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1303 select FW_LOADER 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 select FW_LOADER 1326 ---help--- 1327 This options enables microcode patch loading support for Intel 1328 processors. 1329 1330 For the current Intel microcode data package go to 1331 <https://downloadcenter.intel.com> and search for 1332 'Linux Processor Microcode Data File'. 1333 1334config MICROCODE_AMD 1335 bool "AMD microcode loading support" 1336 depends on MICROCODE 1337 select FW_LOADER 1338 ---help--- 1339 If you select this option, microcode patch loading support for AMD 1340 processors will be enabled. 1341 1342config MICROCODE_OLD_INTERFACE 1343 bool "Ancient loading interface (DEPRECATED)" 1344 default n 1345 depends on MICROCODE 1346 ---help--- 1347 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1348 which was used by userspace tools like iucode_tool and microcode.ctl. 1349 It is inadequate because it runs too late to be able to properly 1350 load microcode on a machine and it needs special tools. Instead, you 1351 should've switched to the early loading method with the initrd or 1352 builtin microcode by now: Documentation/x86/microcode.rst 1353 1354config X86_MSR 1355 tristate "/dev/cpu/*/msr - Model-specific register support" 1356 ---help--- 1357 This device gives privileged processes access to the x86 1358 Model-Specific Registers (MSRs). It is a character device with 1359 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1360 MSR accesses are directed to a specific CPU on multi-processor 1361 systems. 1362 1363config X86_CPUID 1364 tristate "/dev/cpu/*/cpuid - CPU information support" 1365 ---help--- 1366 This device gives processes access to the x86 CPUID instruction to 1367 be executed on a specific processor. It is a character device 1368 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1369 /dev/cpu/31/cpuid. 1370 1371choice 1372 prompt "High Memory Support" 1373 default HIGHMEM4G 1374 depends on X86_32 1375 1376config NOHIGHMEM 1377 bool "off" 1378 ---help--- 1379 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1380 However, the address space of 32-bit x86 processors is only 4 1381 Gigabytes large. That means that, if you have a large amount of 1382 physical memory, not all of it can be "permanently mapped" by the 1383 kernel. The physical memory that's not permanently mapped is called 1384 "high memory". 1385 1386 If you are compiling a kernel which will never run on a machine with 1387 more than 1 Gigabyte total physical RAM, answer "off" here (default 1388 choice and suitable for most users). This will result in a "3GB/1GB" 1389 split: 3GB are mapped so that each process sees a 3GB virtual memory 1390 space and the remaining part of the 4GB virtual memory space is used 1391 by the kernel to permanently map as much physical memory as 1392 possible. 1393 1394 If the machine has between 1 and 4 Gigabytes physical RAM, then 1395 answer "4GB" here. 1396 1397 If more than 4 Gigabytes is used then answer "64GB" here. This 1398 selection turns Intel PAE (Physical Address Extension) mode on. 1399 PAE implements 3-level paging on IA32 processors. PAE is fully 1400 supported by Linux, PAE mode is implemented on all recent Intel 1401 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1402 then the kernel will not boot on CPUs that don't support PAE! 1403 1404 The actual amount of total physical memory will either be 1405 auto detected or can be forced by using a kernel command line option 1406 such as "mem=256M". (Try "man bootparam" or see the documentation of 1407 your boot loader (lilo or loadlin) about how to pass options to the 1408 kernel at boot time.) 1409 1410 If unsure, say "off". 1411 1412config HIGHMEM4G 1413 bool "4GB" 1414 ---help--- 1415 Select this if you have a 32-bit processor and between 1 and 4 1416 gigabytes of physical RAM. 1417 1418config HIGHMEM64G 1419 bool "64GB" 1420 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1421 select X86_PAE 1422 ---help--- 1423 Select this if you have a 32-bit processor and more than 4 1424 gigabytes of physical RAM. 1425 1426endchoice 1427 1428choice 1429 prompt "Memory split" if EXPERT 1430 default VMSPLIT_3G 1431 depends on X86_32 1432 ---help--- 1433 Select the desired split between kernel and user memory. 1434 1435 If the address range available to the kernel is less than the 1436 physical memory installed, the remaining memory will be available 1437 as "high memory". Accessing high memory is a little more costly 1438 than low memory, as it needs to be mapped into the kernel first. 1439 Note that increasing the kernel address space limits the range 1440 available to user programs, making the address space there 1441 tighter. Selecting anything other than the default 3G/1G split 1442 will also likely make your kernel incompatible with binary-only 1443 kernel modules. 1444 1445 If you are not absolutely sure what you are doing, leave this 1446 option alone! 1447 1448 config VMSPLIT_3G 1449 bool "3G/1G user/kernel split" 1450 config VMSPLIT_3G_OPT 1451 depends on !X86_PAE 1452 bool "3G/1G user/kernel split (for full 1G low memory)" 1453 config VMSPLIT_2G 1454 bool "2G/2G user/kernel split" 1455 config VMSPLIT_2G_OPT 1456 depends on !X86_PAE 1457 bool "2G/2G user/kernel split (for full 2G low memory)" 1458 config VMSPLIT_1G 1459 bool "1G/3G user/kernel split" 1460endchoice 1461 1462config PAGE_OFFSET 1463 hex 1464 default 0xB0000000 if VMSPLIT_3G_OPT 1465 default 0x80000000 if VMSPLIT_2G 1466 default 0x78000000 if VMSPLIT_2G_OPT 1467 default 0x40000000 if VMSPLIT_1G 1468 default 0xC0000000 1469 depends on X86_32 1470 1471config HIGHMEM 1472 def_bool y 1473 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1474 1475config X86_PAE 1476 bool "PAE (Physical Address Extension) Support" 1477 depends on X86_32 && !HIGHMEM4G 1478 select PHYS_ADDR_T_64BIT 1479 select SWIOTLB 1480 ---help--- 1481 PAE is required for NX support, and furthermore enables 1482 larger swapspace support for non-overcommit purposes. It 1483 has the cost of more pagetable lookup overhead, and also 1484 consumes more pagetable space per process. 1485 1486config X86_5LEVEL 1487 bool "Enable 5-level page tables support" 1488 select DYNAMIC_MEMORY_LAYOUT 1489 select SPARSEMEM_VMEMMAP 1490 depends on X86_64 1491 ---help--- 1492 5-level paging enables access to larger address space: 1493 upto 128 PiB of virtual address space and 4 PiB of 1494 physical address space. 1495 1496 It will be supported by future Intel CPUs. 1497 1498 A kernel with the option enabled can be booted on machines that 1499 support 4- or 5-level paging. 1500 1501 See Documentation/x86/x86_64/5level-paging.rst for more 1502 information. 1503 1504 Say N if unsure. 1505 1506config X86_DIRECT_GBPAGES 1507 def_bool y 1508 depends on X86_64 && !DEBUG_PAGEALLOC 1509 ---help--- 1510 Certain kernel features effectively disable kernel 1511 linear 1 GB mappings (even if the CPU otherwise 1512 supports them), so don't confuse the user by printing 1513 that we have them enabled. 1514 1515config X86_CPA_STATISTICS 1516 bool "Enable statistic for Change Page Attribute" 1517 depends on DEBUG_FS 1518 ---help--- 1519 Expose statistics about the Change Page Attribute mechanims, which 1520 helps to determine the effectiveness of preserving large and huge 1521 page mappings when mapping protections are changed. 1522 1523config ARCH_HAS_MEM_ENCRYPT 1524 def_bool y 1525 1526config AMD_MEM_ENCRYPT 1527 bool "AMD Secure Memory Encryption (SME) support" 1528 depends on X86_64 && CPU_SUP_AMD 1529 select DYNAMIC_PHYSICAL_MASK 1530 select ARCH_USE_MEMREMAP_PROT 1531 ---help--- 1532 Say yes to enable support for the encryption of system memory. 1533 This requires an AMD processor that supports Secure Memory 1534 Encryption (SME). 1535 1536config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1537 bool "Activate AMD Secure Memory Encryption (SME) by default" 1538 default y 1539 depends on AMD_MEM_ENCRYPT 1540 ---help--- 1541 Say yes to have system memory encrypted by default if running on 1542 an AMD processor that supports Secure Memory Encryption (SME). 1543 1544 If set to Y, then the encryption of system memory can be 1545 deactivated with the mem_encrypt=off command line option. 1546 1547 If set to N, then the encryption of system memory can be 1548 activated with the mem_encrypt=on command line option. 1549 1550# Common NUMA Features 1551config NUMA 1552 bool "Numa Memory Allocation and Scheduler Support" 1553 depends on SMP 1554 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1555 default y if X86_BIGSMP 1556 ---help--- 1557 Enable NUMA (Non Uniform Memory Access) support. 1558 1559 The kernel will try to allocate memory used by a CPU on the 1560 local memory controller of the CPU and add some more 1561 NUMA awareness to the kernel. 1562 1563 For 64-bit this is recommended if the system is Intel Core i7 1564 (or later), AMD Opteron, or EM64T NUMA. 1565 1566 For 32-bit this is only needed if you boot a 32-bit 1567 kernel on a 64-bit NUMA platform. 1568 1569 Otherwise, you should say N. 1570 1571config AMD_NUMA 1572 def_bool y 1573 prompt "Old style AMD Opteron NUMA detection" 1574 depends on X86_64 && NUMA && PCI 1575 ---help--- 1576 Enable AMD NUMA node topology detection. You should say Y here if 1577 you have a multi processor AMD system. This uses an old method to 1578 read the NUMA configuration directly from the builtin Northbridge 1579 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1580 which also takes priority if both are compiled in. 1581 1582config X86_64_ACPI_NUMA 1583 def_bool y 1584 prompt "ACPI NUMA detection" 1585 depends on X86_64 && NUMA && ACPI && PCI 1586 select ACPI_NUMA 1587 ---help--- 1588 Enable ACPI SRAT based node topology detection. 1589 1590# Some NUMA nodes have memory ranges that span 1591# other nodes. Even though a pfn is valid and 1592# between a node's start and end pfns, it may not 1593# reside on that node. See memmap_init_zone() 1594# for details. 1595config NODES_SPAN_OTHER_NODES 1596 def_bool y 1597 depends on X86_64_ACPI_NUMA 1598 1599config NUMA_EMU 1600 bool "NUMA emulation" 1601 depends on NUMA 1602 ---help--- 1603 Enable NUMA emulation. A flat machine will be split 1604 into virtual nodes when booted with "numa=fake=N", where N is the 1605 number of nodes. This is only useful for debugging. 1606 1607config NODES_SHIFT 1608 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1609 range 1 10 1610 default "10" if MAXSMP 1611 default "6" if X86_64 1612 default "3" 1613 depends on NEED_MULTIPLE_NODES 1614 ---help--- 1615 Specify the maximum number of NUMA Nodes available on the target 1616 system. Increases memory reserved to accommodate various tables. 1617 1618config ARCH_HAVE_MEMORY_PRESENT 1619 def_bool y 1620 depends on X86_32 && DISCONTIGMEM 1621 1622config ARCH_FLATMEM_ENABLE 1623 def_bool y 1624 depends on X86_32 && !NUMA 1625 1626config ARCH_DISCONTIGMEM_ENABLE 1627 def_bool n 1628 depends on NUMA && X86_32 1629 depends on BROKEN 1630 1631config ARCH_SPARSEMEM_ENABLE 1632 def_bool y 1633 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1634 select SPARSEMEM_STATIC if X86_32 1635 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1636 1637config ARCH_SPARSEMEM_DEFAULT 1638 def_bool X86_64 || (NUMA && X86_32) 1639 1640config ARCH_SELECT_MEMORY_MODEL 1641 def_bool y 1642 depends on ARCH_SPARSEMEM_ENABLE 1643 1644config ARCH_MEMORY_PROBE 1645 bool "Enable sysfs memory/probe interface" 1646 depends on X86_64 && MEMORY_HOTPLUG 1647 help 1648 This option enables a sysfs memory/probe interface for testing. 1649 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1650 If you are unsure how to answer this question, answer N. 1651 1652config ARCH_PROC_KCORE_TEXT 1653 def_bool y 1654 depends on X86_64 && PROC_KCORE 1655 1656config ILLEGAL_POINTER_VALUE 1657 hex 1658 default 0 if X86_32 1659 default 0xdead000000000000 if X86_64 1660 1661config X86_PMEM_LEGACY_DEVICE 1662 bool 1663 1664config X86_PMEM_LEGACY 1665 tristate "Support non-standard NVDIMMs and ADR protected memory" 1666 depends on PHYS_ADDR_T_64BIT 1667 depends on BLK_DEV 1668 select X86_PMEM_LEGACY_DEVICE 1669 select LIBNVDIMM 1670 help 1671 Treat memory marked using the non-standard e820 type of 12 as used 1672 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1673 The kernel will offer these regions to the 'pmem' driver so 1674 they can be used for persistent storage. 1675 1676 Say Y if unsure. 1677 1678config HIGHPTE 1679 bool "Allocate 3rd-level pagetables from highmem" 1680 depends on HIGHMEM 1681 ---help--- 1682 The VM uses one page table entry for each page of physical memory. 1683 For systems with a lot of RAM, this can be wasteful of precious 1684 low memory. Setting this option will put user-space page table 1685 entries in high memory. 1686 1687config X86_CHECK_BIOS_CORRUPTION 1688 bool "Check for low memory corruption" 1689 ---help--- 1690 Periodically check for memory corruption in low memory, which 1691 is suspected to be caused by BIOS. Even when enabled in the 1692 configuration, it is disabled at runtime. Enable it by 1693 setting "memory_corruption_check=1" on the kernel command 1694 line. By default it scans the low 64k of memory every 60 1695 seconds; see the memory_corruption_check_size and 1696 memory_corruption_check_period parameters in 1697 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1698 1699 When enabled with the default parameters, this option has 1700 almost no overhead, as it reserves a relatively small amount 1701 of memory and scans it infrequently. It both detects corruption 1702 and prevents it from affecting the running system. 1703 1704 It is, however, intended as a diagnostic tool; if repeatable 1705 BIOS-originated corruption always affects the same memory, 1706 you can use memmap= to prevent the kernel from using that 1707 memory. 1708 1709config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1710 bool "Set the default setting of memory_corruption_check" 1711 depends on X86_CHECK_BIOS_CORRUPTION 1712 default y 1713 ---help--- 1714 Set whether the default state of memory_corruption_check is 1715 on or off. 1716 1717config X86_RESERVE_LOW 1718 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1719 default 64 1720 range 4 640 1721 ---help--- 1722 Specify the amount of low memory to reserve for the BIOS. 1723 1724 The first page contains BIOS data structures that the kernel 1725 must not use, so that page must always be reserved. 1726 1727 By default we reserve the first 64K of physical RAM, as a 1728 number of BIOSes are known to corrupt that memory range 1729 during events such as suspend/resume or monitor cable 1730 insertion, so it must not be used by the kernel. 1731 1732 You can set this to 4 if you are absolutely sure that you 1733 trust the BIOS to get all its memory reservations and usages 1734 right. If you know your BIOS have problems beyond the 1735 default 64K area, you can set this to 640 to avoid using the 1736 entire low memory range. 1737 1738 If you have doubts about the BIOS (e.g. suspend/resume does 1739 not work or there's kernel crashes after certain hardware 1740 hotplug events) then you might want to enable 1741 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1742 typical corruption patterns. 1743 1744 Leave this to the default value of 64 if you are unsure. 1745 1746config MATH_EMULATION 1747 bool 1748 depends on MODIFY_LDT_SYSCALL 1749 prompt "Math emulation" if X86_32 1750 ---help--- 1751 Linux can emulate a math coprocessor (used for floating point 1752 operations) if you don't have one. 486DX and Pentium processors have 1753 a math coprocessor built in, 486SX and 386 do not, unless you added 1754 a 487DX or 387, respectively. (The messages during boot time can 1755 give you some hints here ["man dmesg"].) Everyone needs either a 1756 coprocessor or this emulation. 1757 1758 If you don't have a math coprocessor, you need to say Y here; if you 1759 say Y here even though you have a coprocessor, the coprocessor will 1760 be used nevertheless. (This behavior can be changed with the kernel 1761 command line option "no387", which comes handy if your coprocessor 1762 is broken. Try "man bootparam" or see the documentation of your boot 1763 loader (lilo or loadlin) about how to pass options to the kernel at 1764 boot time.) This means that it is a good idea to say Y here if you 1765 intend to use this kernel on different machines. 1766 1767 More information about the internals of the Linux math coprocessor 1768 emulation can be found in <file:arch/x86/math-emu/README>. 1769 1770 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1771 kernel, it won't hurt. 1772 1773config MTRR 1774 def_bool y 1775 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1776 ---help--- 1777 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1778 the Memory Type Range Registers (MTRRs) may be used to control 1779 processor access to memory ranges. This is most useful if you have 1780 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1781 allows bus write transfers to be combined into a larger transfer 1782 before bursting over the PCI/AGP bus. This can increase performance 1783 of image write operations 2.5 times or more. Saying Y here creates a 1784 /proc/mtrr file which may be used to manipulate your processor's 1785 MTRRs. Typically the X server should use this. 1786 1787 This code has a reasonably generic interface so that similar 1788 control registers on other processors can be easily supported 1789 as well: 1790 1791 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1792 Registers (ARRs) which provide a similar functionality to MTRRs. For 1793 these, the ARRs are used to emulate the MTRRs. 1794 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1795 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1796 write-combining. All of these processors are supported by this code 1797 and it makes sense to say Y here if you have one of them. 1798 1799 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1800 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1801 can lead to all sorts of problems, so it's good to say Y here. 1802 1803 You can safely say Y even if your machine doesn't have MTRRs, you'll 1804 just add about 9 KB to your kernel. 1805 1806 See <file:Documentation/x86/mtrr.rst> for more information. 1807 1808config MTRR_SANITIZER 1809 def_bool y 1810 prompt "MTRR cleanup support" 1811 depends on MTRR 1812 ---help--- 1813 Convert MTRR layout from continuous to discrete, so X drivers can 1814 add writeback entries. 1815 1816 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1817 The largest mtrr entry size for a continuous block can be set with 1818 mtrr_chunk_size. 1819 1820 If unsure, say Y. 1821 1822config MTRR_SANITIZER_ENABLE_DEFAULT 1823 int "MTRR cleanup enable value (0-1)" 1824 range 0 1 1825 default "0" 1826 depends on MTRR_SANITIZER 1827 ---help--- 1828 Enable mtrr cleanup default value 1829 1830config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1831 int "MTRR cleanup spare reg num (0-7)" 1832 range 0 7 1833 default "1" 1834 depends on MTRR_SANITIZER 1835 ---help--- 1836 mtrr cleanup spare entries default, it can be changed via 1837 mtrr_spare_reg_nr=N on the kernel command line. 1838 1839config X86_PAT 1840 def_bool y 1841 prompt "x86 PAT support" if EXPERT 1842 depends on MTRR 1843 ---help--- 1844 Use PAT attributes to setup page level cache control. 1845 1846 PATs are the modern equivalents of MTRRs and are much more 1847 flexible than MTRRs. 1848 1849 Say N here if you see bootup problems (boot crash, boot hang, 1850 spontaneous reboots) or a non-working video driver. 1851 1852 If unsure, say Y. 1853 1854config ARCH_USES_PG_UNCACHED 1855 def_bool y 1856 depends on X86_PAT 1857 1858config ARCH_RANDOM 1859 def_bool y 1860 prompt "x86 architectural random number generator" if EXPERT 1861 ---help--- 1862 Enable the x86 architectural RDRAND instruction 1863 (Intel Bull Mountain technology) to generate random numbers. 1864 If supported, this is a high bandwidth, cryptographically 1865 secure hardware random number generator. 1866 1867config X86_SMAP 1868 def_bool y 1869 prompt "Supervisor Mode Access Prevention" if EXPERT 1870 ---help--- 1871 Supervisor Mode Access Prevention (SMAP) is a security 1872 feature in newer Intel processors. There is a small 1873 performance cost if this enabled and turned on; there is 1874 also a small increase in the kernel size if this is enabled. 1875 1876 If unsure, say Y. 1877 1878config X86_INTEL_UMIP 1879 def_bool y 1880 depends on CPU_SUP_INTEL 1881 prompt "Intel User Mode Instruction Prevention" if EXPERT 1882 ---help--- 1883 The User Mode Instruction Prevention (UMIP) is a security 1884 feature in newer Intel processors. If enabled, a general 1885 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1886 or STR instructions are executed in user mode. These instructions 1887 unnecessarily expose information about the hardware state. 1888 1889 The vast majority of applications do not use these instructions. 1890 For the very few that do, software emulation is provided in 1891 specific cases in protected and virtual-8086 modes. Emulated 1892 results are dummy. 1893 1894config X86_INTEL_MPX 1895 prompt "Intel MPX (Memory Protection Extensions)" 1896 def_bool n 1897 # Note: only available in 64-bit mode due to VMA flags shortage 1898 depends on CPU_SUP_INTEL && X86_64 1899 select ARCH_USES_HIGH_VMA_FLAGS 1900 ---help--- 1901 MPX provides hardware features that can be used in 1902 conjunction with compiler-instrumented code to check 1903 memory references. It is designed to detect buffer 1904 overflow or underflow bugs. 1905 1906 This option enables running applications which are 1907 instrumented or otherwise use MPX. It does not use MPX 1908 itself inside the kernel or to protect the kernel 1909 against bad memory references. 1910 1911 Enabling this option will make the kernel larger: 1912 ~8k of kernel text and 36 bytes of data on a 64-bit 1913 defconfig. It adds a long to the 'mm_struct' which 1914 will increase the kernel memory overhead of each 1915 process and adds some branches to paths used during 1916 exec() and munmap(). 1917 1918 For details, see Documentation/x86/intel_mpx.rst 1919 1920 If unsure, say N. 1921 1922config X86_INTEL_MEMORY_PROTECTION_KEYS 1923 prompt "Intel Memory Protection Keys" 1924 def_bool y 1925 # Note: only available in 64-bit mode 1926 depends on CPU_SUP_INTEL && X86_64 1927 select ARCH_USES_HIGH_VMA_FLAGS 1928 select ARCH_HAS_PKEYS 1929 ---help--- 1930 Memory Protection Keys provides a mechanism for enforcing 1931 page-based protections, but without requiring modification of the 1932 page tables when an application changes protection domains. 1933 1934 For details, see Documentation/core-api/protection-keys.rst 1935 1936 If unsure, say y. 1937 1938config EFI 1939 bool "EFI runtime service support" 1940 depends on ACPI 1941 select UCS2_STRING 1942 select EFI_RUNTIME_WRAPPERS 1943 ---help--- 1944 This enables the kernel to use EFI runtime services that are 1945 available (such as the EFI variable services). 1946 1947 This option is only useful on systems that have EFI firmware. 1948 In addition, you should use the latest ELILO loader available 1949 at <http://elilo.sourceforge.net> in order to take advantage 1950 of EFI runtime services. However, even with this option, the 1951 resultant kernel should continue to boot on existing non-EFI 1952 platforms. 1953 1954config EFI_STUB 1955 bool "EFI stub support" 1956 depends on EFI && !X86_USE_3DNOW 1957 select RELOCATABLE 1958 ---help--- 1959 This kernel feature allows a bzImage to be loaded directly 1960 by EFI firmware without the use of a bootloader. 1961 1962 See Documentation/admin-guide/efi-stub.rst for more information. 1963 1964config EFI_MIXED 1965 bool "EFI mixed-mode support" 1966 depends on EFI_STUB && X86_64 1967 ---help--- 1968 Enabling this feature allows a 64-bit kernel to be booted 1969 on a 32-bit firmware, provided that your CPU supports 64-bit 1970 mode. 1971 1972 Note that it is not possible to boot a mixed-mode enabled 1973 kernel via the EFI boot stub - a bootloader that supports 1974 the EFI handover protocol must be used. 1975 1976 If unsure, say N. 1977 1978config SECCOMP 1979 def_bool y 1980 prompt "Enable seccomp to safely compute untrusted bytecode" 1981 ---help--- 1982 This kernel feature is useful for number crunching applications 1983 that may need to compute untrusted bytecode during their 1984 execution. By using pipes or other transports made available to 1985 the process as file descriptors supporting the read/write 1986 syscalls, it's possible to isolate those applications in 1987 their own address space using seccomp. Once seccomp is 1988 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1989 and the task is only allowed to execute a few safe syscalls 1990 defined by each seccomp mode. 1991 1992 If unsure, say Y. Only embedded should say N here. 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_VERIFY_SIG 2030 bool "Verify kernel signature during kexec_file_load() syscall" 2031 depends on KEXEC_FILE 2032 ---help--- 2033 This option makes kernel signature verification mandatory for 2034 the kexec_file_load() syscall. 2035 2036 In addition to that option, you need to enable signature 2037 verification for the corresponding kernel image type being 2038 loaded in order for this to work. 2039 2040config KEXEC_BZIMAGE_VERIFY_SIG 2041 bool "Enable bzImage signature verification support" 2042 depends on KEXEC_VERIFY_SIG 2043 depends on SIGNED_PE_FILE_VERIFICATION 2044 select SYSTEM_TRUSTED_KEYRING 2045 ---help--- 2046 Enable bzImage signature verification support. 2047 2048config CRASH_DUMP 2049 bool "kernel crash dumps" 2050 depends on X86_64 || (X86_32 && HIGHMEM) 2051 ---help--- 2052 Generate crash dump after being started by kexec. 2053 This should be normally only set in special crash dump kernels 2054 which are loaded in the main kernel with kexec-tools into 2055 a specially reserved region and then later executed after 2056 a crash by kdump/kexec. The crash dump kernel must be compiled 2057 to a memory address not used by the main kernel or BIOS using 2058 PHYSICAL_START, or it must be built as a relocatable image 2059 (CONFIG_RELOCATABLE=y). 2060 For more details see Documentation/admin-guide/kdump/kdump.rst 2061 2062config KEXEC_JUMP 2063 bool "kexec jump" 2064 depends on KEXEC && HIBERNATION 2065 ---help--- 2066 Jump between original kernel and kexeced kernel and invoke 2067 code in physical address mode via KEXEC 2068 2069config PHYSICAL_START 2070 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2071 default "0x1000000" 2072 ---help--- 2073 This gives the physical address where the kernel is loaded. 2074 2075 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2076 bzImage will decompress itself to above physical address and 2077 run from there. Otherwise, bzImage will run from the address where 2078 it has been loaded by the boot loader and will ignore above physical 2079 address. 2080 2081 In normal kdump cases one does not have to set/change this option 2082 as now bzImage can be compiled as a completely relocatable image 2083 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2084 address. This option is mainly useful for the folks who don't want 2085 to use a bzImage for capturing the crash dump and want to use a 2086 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2087 to be specifically compiled to run from a specific memory area 2088 (normally a reserved region) and this option comes handy. 2089 2090 So if you are using bzImage for capturing the crash dump, 2091 leave the value here unchanged to 0x1000000 and set 2092 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2093 for capturing the crash dump change this value to start of 2094 the reserved region. In other words, it can be set based on 2095 the "X" value as specified in the "crashkernel=YM@XM" 2096 command line boot parameter passed to the panic-ed 2097 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2098 for more details about crash dumps. 2099 2100 Usage of bzImage for capturing the crash dump is recommended as 2101 one does not have to build two kernels. Same kernel can be used 2102 as production kernel and capture kernel. Above option should have 2103 gone away after relocatable bzImage support is introduced. But it 2104 is present because there are users out there who continue to use 2105 vmlinux for dump capture. This option should go away down the 2106 line. 2107 2108 Don't change this unless you know what you are doing. 2109 2110config RELOCATABLE 2111 bool "Build a relocatable kernel" 2112 default y 2113 ---help--- 2114 This builds a kernel image that retains relocation information 2115 so it can be loaded someplace besides the default 1MB. 2116 The relocations tend to make the kernel binary about 10% larger, 2117 but are discarded at runtime. 2118 2119 One use is for the kexec on panic case where the recovery kernel 2120 must live at a different physical address than the primary 2121 kernel. 2122 2123 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2124 it has been loaded at and the compile time physical address 2125 (CONFIG_PHYSICAL_START) is used as the minimum location. 2126 2127config RANDOMIZE_BASE 2128 bool "Randomize the address of the kernel image (KASLR)" 2129 depends on RELOCATABLE 2130 default y 2131 ---help--- 2132 In support of Kernel Address Space Layout Randomization (KASLR), 2133 this randomizes the physical address at which the kernel image 2134 is decompressed and the virtual address where the kernel 2135 image is mapped, as a security feature that deters exploit 2136 attempts relying on knowledge of the location of kernel 2137 code internals. 2138 2139 On 64-bit, the kernel physical and virtual addresses are 2140 randomized separately. The physical address will be anywhere 2141 between 16MB and the top of physical memory (up to 64TB). The 2142 virtual address will be randomized from 16MB up to 1GB (9 bits 2143 of entropy). Note that this also reduces the memory space 2144 available to kernel modules from 1.5GB to 1GB. 2145 2146 On 32-bit, the kernel physical and virtual addresses are 2147 randomized together. They will be randomized from 16MB up to 2148 512MB (8 bits of entropy). 2149 2150 Entropy is generated using the RDRAND instruction if it is 2151 supported. If RDTSC is supported, its value is mixed into 2152 the entropy pool as well. If neither RDRAND nor RDTSC are 2153 supported, then entropy is read from the i8254 timer. The 2154 usable entropy is limited by the kernel being built using 2155 2GB addressing, and that PHYSICAL_ALIGN must be at a 2156 minimum of 2MB. As a result, only 10 bits of entropy are 2157 theoretically possible, but the implementations are further 2158 limited due to memory layouts. 2159 2160 If unsure, say Y. 2161 2162# Relocation on x86 needs some additional build support 2163config X86_NEED_RELOCS 2164 def_bool y 2165 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2166 2167config PHYSICAL_ALIGN 2168 hex "Alignment value to which kernel should be aligned" 2169 default "0x200000" 2170 range 0x2000 0x1000000 if X86_32 2171 range 0x200000 0x1000000 if X86_64 2172 ---help--- 2173 This value puts the alignment restrictions on physical address 2174 where kernel is loaded and run from. Kernel is compiled for an 2175 address which meets above alignment restriction. 2176 2177 If bootloader loads the kernel at a non-aligned address and 2178 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2179 address aligned to above value and run from there. 2180 2181 If bootloader loads the kernel at a non-aligned address and 2182 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2183 load address and decompress itself to the address it has been 2184 compiled for and run from there. The address for which kernel is 2185 compiled already meets above alignment restrictions. Hence the 2186 end result is that kernel runs from a physical address meeting 2187 above alignment restrictions. 2188 2189 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2190 this value must be a multiple of 0x200000. 2191 2192 Don't change this unless you know what you are doing. 2193 2194config DYNAMIC_MEMORY_LAYOUT 2195 bool 2196 ---help--- 2197 This option makes base addresses of vmalloc and vmemmap as well as 2198 __PAGE_OFFSET movable during boot. 2199 2200config RANDOMIZE_MEMORY 2201 bool "Randomize the kernel memory sections" 2202 depends on X86_64 2203 depends on RANDOMIZE_BASE 2204 select DYNAMIC_MEMORY_LAYOUT 2205 default RANDOMIZE_BASE 2206 ---help--- 2207 Randomizes the base virtual address of kernel memory sections 2208 (physical memory mapping, vmalloc & vmemmap). This security feature 2209 makes exploits relying on predictable memory locations less reliable. 2210 2211 The order of allocations remains unchanged. Entropy is generated in 2212 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2213 configuration have in average 30,000 different possible virtual 2214 addresses for each memory section. 2215 2216 If unsure, say Y. 2217 2218config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2219 hex "Physical memory mapping padding" if EXPERT 2220 depends on RANDOMIZE_MEMORY 2221 default "0xa" if MEMORY_HOTPLUG 2222 default "0x0" 2223 range 0x1 0x40 if MEMORY_HOTPLUG 2224 range 0x0 0x40 2225 ---help--- 2226 Define the padding in terabytes added to the existing physical 2227 memory size during kernel memory randomization. It is useful 2228 for memory hotplug support but reduces the entropy available for 2229 address randomization. 2230 2231 If unsure, leave at the default value. 2232 2233config HOTPLUG_CPU 2234 def_bool y 2235 depends on SMP 2236 2237config BOOTPARAM_HOTPLUG_CPU0 2238 bool "Set default setting of cpu0_hotpluggable" 2239 depends on HOTPLUG_CPU 2240 ---help--- 2241 Set whether default state of cpu0_hotpluggable is on or off. 2242 2243 Say Y here to enable CPU0 hotplug by default. If this switch 2244 is turned on, there is no need to give cpu0_hotplug kernel 2245 parameter and the CPU0 hotplug feature is enabled by default. 2246 2247 Please note: there are two known CPU0 dependencies if you want 2248 to enable the CPU0 hotplug feature either by this switch or by 2249 cpu0_hotplug kernel parameter. 2250 2251 First, resume from hibernate or suspend always starts from CPU0. 2252 So hibernate and suspend are prevented if CPU0 is offline. 2253 2254 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2255 offline if any interrupt can not migrate out of CPU0. There may 2256 be other CPU0 dependencies. 2257 2258 Please make sure the dependencies are under your control before 2259 you enable this feature. 2260 2261 Say N if you don't want to enable CPU0 hotplug feature by default. 2262 You still can enable the CPU0 hotplug feature at boot by kernel 2263 parameter cpu0_hotplug. 2264 2265config DEBUG_HOTPLUG_CPU0 2266 def_bool n 2267 prompt "Debug CPU0 hotplug" 2268 depends on HOTPLUG_CPU 2269 ---help--- 2270 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2271 soon as possible and boots up userspace with CPU0 offlined. User 2272 can online CPU0 back after boot time. 2273 2274 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2275 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2276 compilation or giving cpu0_hotplug kernel parameter at boot. 2277 2278 If unsure, say N. 2279 2280config COMPAT_VDSO 2281 def_bool n 2282 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2283 depends on COMPAT_32 2284 ---help--- 2285 Certain buggy versions of glibc will crash if they are 2286 presented with a 32-bit vDSO that is not mapped at the address 2287 indicated in its segment table. 2288 2289 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2290 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2291 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2292 the only released version with the bug, but OpenSUSE 9 2293 contains a buggy "glibc 2.3.2". 2294 2295 The symptom of the bug is that everything crashes on startup, saying: 2296 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2297 2298 Saying Y here changes the default value of the vdso32 boot 2299 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2300 This works around the glibc bug but hurts performance. 2301 2302 If unsure, say N: if you are compiling your own kernel, you 2303 are unlikely to be using a buggy version of glibc. 2304 2305choice 2306 prompt "vsyscall table for legacy applications" 2307 depends on X86_64 2308 default LEGACY_VSYSCALL_XONLY 2309 help 2310 Legacy user code that does not know how to find the vDSO expects 2311 to be able to issue three syscalls by calling fixed addresses in 2312 kernel space. Since this location is not randomized with ASLR, 2313 it can be used to assist security vulnerability exploitation. 2314 2315 This setting can be changed at boot time via the kernel command 2316 line parameter vsyscall=[emulate|xonly|none]. 2317 2318 On a system with recent enough glibc (2.14 or newer) and no 2319 static binaries, you can say None without a performance penalty 2320 to improve security. 2321 2322 If unsure, select "Emulate execution only". 2323 2324 config LEGACY_VSYSCALL_EMULATE 2325 bool "Full emulation" 2326 help 2327 The kernel traps and emulates calls into the fixed vsyscall 2328 address mapping. This makes the mapping non-executable, but 2329 it still contains readable known contents, which could be 2330 used in certain rare security vulnerability exploits. This 2331 configuration is recommended when using legacy userspace 2332 that still uses vsyscalls along with legacy binary 2333 instrumentation tools that require code to be readable. 2334 2335 An example of this type of legacy userspace is running 2336 Pin on an old binary that still uses vsyscalls. 2337 2338 config LEGACY_VSYSCALL_XONLY 2339 bool "Emulate execution only" 2340 help 2341 The kernel traps and emulates calls into the fixed vsyscall 2342 address mapping and does not allow reads. This 2343 configuration is recommended when userspace might use the 2344 legacy vsyscall area but support for legacy binary 2345 instrumentation of legacy code is not needed. It mitigates 2346 certain uses of the vsyscall area as an ASLR-bypassing 2347 buffer. 2348 2349 config LEGACY_VSYSCALL_NONE 2350 bool "None" 2351 help 2352 There will be no vsyscall mapping at all. This will 2353 eliminate any risk of ASLR bypass due to the vsyscall 2354 fixed address mapping. Attempts to use the vsyscalls 2355 will be reported to dmesg, so that either old or 2356 malicious userspace programs can be identified. 2357 2358endchoice 2359 2360config CMDLINE_BOOL 2361 bool "Built-in kernel command line" 2362 ---help--- 2363 Allow for specifying boot arguments to the kernel at 2364 build time. On some systems (e.g. embedded ones), it is 2365 necessary or convenient to provide some or all of the 2366 kernel boot arguments with the kernel itself (that is, 2367 to not rely on the boot loader to provide them.) 2368 2369 To compile command line arguments into the kernel, 2370 set this option to 'Y', then fill in the 2371 boot arguments in CONFIG_CMDLINE. 2372 2373 Systems with fully functional boot loaders (i.e. non-embedded) 2374 should leave this option set to 'N'. 2375 2376config CMDLINE 2377 string "Built-in kernel command string" 2378 depends on CMDLINE_BOOL 2379 default "" 2380 ---help--- 2381 Enter arguments here that should be compiled into the kernel 2382 image and used at boot time. If the boot loader provides a 2383 command line at boot time, it is appended to this string to 2384 form the full kernel command line, when the system boots. 2385 2386 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2387 change this behavior. 2388 2389 In most cases, the command line (whether built-in or provided 2390 by the boot loader) should specify the device for the root 2391 file system. 2392 2393config CMDLINE_OVERRIDE 2394 bool "Built-in command line overrides boot loader arguments" 2395 depends on CMDLINE_BOOL 2396 ---help--- 2397 Set this option to 'Y' to have the kernel ignore the boot loader 2398 command line, and use ONLY the built-in command line. 2399 2400 This is used to work around broken boot loaders. This should 2401 be set to 'N' under normal conditions. 2402 2403config MODIFY_LDT_SYSCALL 2404 bool "Enable the LDT (local descriptor table)" if EXPERT 2405 default y 2406 ---help--- 2407 Linux can allow user programs to install a per-process x86 2408 Local Descriptor Table (LDT) using the modify_ldt(2) system 2409 call. This is required to run 16-bit or segmented code such as 2410 DOSEMU or some Wine programs. It is also used by some very old 2411 threading libraries. 2412 2413 Enabling this feature adds a small amount of overhead to 2414 context switches and increases the low-level kernel attack 2415 surface. Disabling it removes the modify_ldt(2) system call. 2416 2417 Saying 'N' here may make sense for embedded or server kernels. 2418 2419source "kernel/livepatch/Kconfig" 2420 2421endmenu 2422 2423config ARCH_HAS_ADD_PAGES 2424 def_bool y 2425 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2426 2427config ARCH_ENABLE_MEMORY_HOTPLUG 2428 def_bool y 2429 depends on X86_64 || (X86_32 && HIGHMEM) 2430 2431config ARCH_ENABLE_MEMORY_HOTREMOVE 2432 def_bool y 2433 depends on MEMORY_HOTPLUG 2434 2435config USE_PERCPU_NUMA_NODE_ID 2436 def_bool y 2437 depends on NUMA 2438 2439config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2440 def_bool y 2441 depends on X86_64 || X86_PAE 2442 2443config ARCH_ENABLE_HUGEPAGE_MIGRATION 2444 def_bool y 2445 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2446 2447config ARCH_ENABLE_THP_MIGRATION 2448 def_bool y 2449 depends on X86_64 && TRANSPARENT_HUGEPAGE 2450 2451menu "Power management and ACPI options" 2452 2453config ARCH_HIBERNATION_HEADER 2454 def_bool y 2455 depends on HIBERNATION 2456 2457source "kernel/power/Kconfig" 2458 2459source "drivers/acpi/Kconfig" 2460 2461source "drivers/sfi/Kconfig" 2462 2463config X86_APM_BOOT 2464 def_bool y 2465 depends on APM 2466 2467menuconfig APM 2468 tristate "APM (Advanced Power Management) BIOS support" 2469 depends on X86_32 && PM_SLEEP 2470 ---help--- 2471 APM is a BIOS specification for saving power using several different 2472 techniques. This is mostly useful for battery powered laptops with 2473 APM compliant BIOSes. If you say Y here, the system time will be 2474 reset after a RESUME operation, the /proc/apm device will provide 2475 battery status information, and user-space programs will receive 2476 notification of APM "events" (e.g. battery status change). 2477 2478 If you select "Y" here, you can disable actual use of the APM 2479 BIOS by passing the "apm=off" option to the kernel at boot time. 2480 2481 Note that the APM support is almost completely disabled for 2482 machines with more than one CPU. 2483 2484 In order to use APM, you will need supporting software. For location 2485 and more information, read <file:Documentation/power/apm-acpi.txt> 2486 and the Battery Powered Linux mini-HOWTO, available from 2487 <http://www.tldp.org/docs.html#howto>. 2488 2489 This driver does not spin down disk drives (see the hdparm(8) 2490 manpage ("man 8 hdparm") for that), and it doesn't turn off 2491 VESA-compliant "green" monitors. 2492 2493 This driver does not support the TI 4000M TravelMate and the ACER 2494 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2495 desktop machines also don't have compliant BIOSes, and this driver 2496 may cause those machines to panic during the boot phase. 2497 2498 Generally, if you don't have a battery in your machine, there isn't 2499 much point in using this driver and you should say N. If you get 2500 random kernel OOPSes or reboots that don't seem to be related to 2501 anything, try disabling/enabling this option (or disabling/enabling 2502 APM in your BIOS). 2503 2504 Some other things you should try when experiencing seemingly random, 2505 "weird" problems: 2506 2507 1) make sure that you have enough swap space and that it is 2508 enabled. 2509 2) pass the "no-hlt" option to the kernel 2510 3) switch on floating point emulation in the kernel and pass 2511 the "no387" option to the kernel 2512 4) pass the "floppy=nodma" option to the kernel 2513 5) pass the "mem=4M" option to the kernel (thereby disabling 2514 all but the first 4 MB of RAM) 2515 6) make sure that the CPU is not over clocked. 2516 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2517 8) disable the cache from your BIOS settings 2518 9) install a fan for the video card or exchange video RAM 2519 10) install a better fan for the CPU 2520 11) exchange RAM chips 2521 12) exchange the motherboard. 2522 2523 To compile this driver as a module, choose M here: the 2524 module will be called apm. 2525 2526if APM 2527 2528config APM_IGNORE_USER_SUSPEND 2529 bool "Ignore USER SUSPEND" 2530 ---help--- 2531 This option will ignore USER SUSPEND requests. On machines with a 2532 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2533 series notebooks, it is necessary to say Y because of a BIOS bug. 2534 2535config APM_DO_ENABLE 2536 bool "Enable PM at boot time" 2537 ---help--- 2538 Enable APM features at boot time. From page 36 of the APM BIOS 2539 specification: "When disabled, the APM BIOS does not automatically 2540 power manage devices, enter the Standby State, enter the Suspend 2541 State, or take power saving steps in response to CPU Idle calls." 2542 This driver will make CPU Idle calls when Linux is idle (unless this 2543 feature is turned off -- see "Do CPU IDLE calls", below). This 2544 should always save battery power, but more complicated APM features 2545 will be dependent on your BIOS implementation. You may need to turn 2546 this option off if your computer hangs at boot time when using APM 2547 support, or if it beeps continuously instead of suspending. Turn 2548 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2549 T400CDT. This is off by default since most machines do fine without 2550 this feature. 2551 2552config APM_CPU_IDLE 2553 depends on CPU_IDLE 2554 bool "Make CPU Idle calls when idle" 2555 ---help--- 2556 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2557 On some machines, this can activate improved power savings, such as 2558 a slowed CPU clock rate, when the machine is idle. These idle calls 2559 are made after the idle loop has run for some length of time (e.g., 2560 333 mS). On some machines, this will cause a hang at boot time or 2561 whenever the CPU becomes idle. (On machines with more than one CPU, 2562 this option does nothing.) 2563 2564config APM_DISPLAY_BLANK 2565 bool "Enable console blanking using APM" 2566 ---help--- 2567 Enable console blanking using the APM. Some laptops can use this to 2568 turn off the LCD backlight when the screen blanker of the Linux 2569 virtual console blanks the screen. Note that this is only used by 2570 the virtual console screen blanker, and won't turn off the backlight 2571 when using the X Window system. This also doesn't have anything to 2572 do with your VESA-compliant power-saving monitor. Further, this 2573 option doesn't work for all laptops -- it might not turn off your 2574 backlight at all, or it might print a lot of errors to the console, 2575 especially if you are using gpm. 2576 2577config APM_ALLOW_INTS 2578 bool "Allow interrupts during APM BIOS calls" 2579 ---help--- 2580 Normally we disable external interrupts while we are making calls to 2581 the APM BIOS as a measure to lessen the effects of a badly behaving 2582 BIOS implementation. The BIOS should reenable interrupts if it 2583 needs to. Unfortunately, some BIOSes do not -- especially those in 2584 many of the newer IBM Thinkpads. If you experience hangs when you 2585 suspend, try setting this to Y. Otherwise, say N. 2586 2587endif # APM 2588 2589source "drivers/cpufreq/Kconfig" 2590 2591source "drivers/cpuidle/Kconfig" 2592 2593source "drivers/idle/Kconfig" 2594 2595endmenu 2596 2597 2598menu "Bus options (PCI etc.)" 2599 2600choice 2601 prompt "PCI access mode" 2602 depends on X86_32 && PCI 2603 default PCI_GOANY 2604 ---help--- 2605 On PCI systems, the BIOS can be used to detect the PCI devices and 2606 determine their configuration. However, some old PCI motherboards 2607 have BIOS bugs and may crash if this is done. Also, some embedded 2608 PCI-based systems don't have any BIOS at all. Linux can also try to 2609 detect the PCI hardware directly without using the BIOS. 2610 2611 With this option, you can specify how Linux should detect the 2612 PCI devices. If you choose "BIOS", the BIOS will be used, 2613 if you choose "Direct", the BIOS won't be used, and if you 2614 choose "MMConfig", then PCI Express MMCONFIG will be used. 2615 If you choose "Any", the kernel will try MMCONFIG, then the 2616 direct access method and falls back to the BIOS if that doesn't 2617 work. If unsure, go with the default, which is "Any". 2618 2619config PCI_GOBIOS 2620 bool "BIOS" 2621 2622config PCI_GOMMCONFIG 2623 bool "MMConfig" 2624 2625config PCI_GODIRECT 2626 bool "Direct" 2627 2628config PCI_GOOLPC 2629 bool "OLPC XO-1" 2630 depends on OLPC 2631 2632config PCI_GOANY 2633 bool "Any" 2634 2635endchoice 2636 2637config PCI_BIOS 2638 def_bool y 2639 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2640 2641# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2642config PCI_DIRECT 2643 def_bool y 2644 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2645 2646config PCI_MMCONFIG 2647 bool "Support mmconfig PCI config space access" if X86_64 2648 default y 2649 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2650 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2651 2652config PCI_OLPC 2653 def_bool y 2654 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2655 2656config PCI_XEN 2657 def_bool y 2658 depends on PCI && XEN 2659 select SWIOTLB_XEN 2660 2661config MMCONF_FAM10H 2662 def_bool y 2663 depends on X86_64 && PCI_MMCONFIG && ACPI 2664 2665config PCI_CNB20LE_QUIRK 2666 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2667 depends on PCI 2668 help 2669 Read the PCI windows out of the CNB20LE host bridge. This allows 2670 PCI hotplug to work on systems with the CNB20LE chipset which do 2671 not have ACPI. 2672 2673 There's no public spec for this chipset, and this functionality 2674 is known to be incomplete. 2675 2676 You should say N unless you know you need this. 2677 2678config ISA_BUS 2679 bool "ISA bus support on modern systems" if EXPERT 2680 help 2681 Expose ISA bus device drivers and options available for selection and 2682 configuration. Enable this option if your target machine has an ISA 2683 bus. ISA is an older system, displaced by PCI and newer bus 2684 architectures -- if your target machine is modern, it probably does 2685 not have an ISA bus. 2686 2687 If unsure, say N. 2688 2689# x86_64 have no ISA slots, but can have ISA-style DMA. 2690config ISA_DMA_API 2691 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2692 default y 2693 help 2694 Enables ISA-style DMA support for devices requiring such controllers. 2695 If unsure, say Y. 2696 2697if X86_32 2698 2699config ISA 2700 bool "ISA support" 2701 ---help--- 2702 Find out whether you have ISA slots on your motherboard. ISA is the 2703 name of a bus system, i.e. the way the CPU talks to the other stuff 2704 inside your box. Other bus systems are PCI, EISA, MicroChannel 2705 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2706 newer boards don't support it. If you have ISA, say Y, otherwise N. 2707 2708config SCx200 2709 tristate "NatSemi SCx200 support" 2710 ---help--- 2711 This provides basic support for National Semiconductor's 2712 (now AMD's) Geode processors. The driver probes for the 2713 PCI-IDs of several on-chip devices, so its a good dependency 2714 for other scx200_* drivers. 2715 2716 If compiled as a module, the driver is named scx200. 2717 2718config SCx200HR_TIMER 2719 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2720 depends on SCx200 2721 default y 2722 ---help--- 2723 This driver provides a clocksource built upon the on-chip 2724 27MHz high-resolution timer. Its also a workaround for 2725 NSC Geode SC-1100's buggy TSC, which loses time when the 2726 processor goes idle (as is done by the scheduler). The 2727 other workaround is idle=poll boot option. 2728 2729config OLPC 2730 bool "One Laptop Per Child support" 2731 depends on !X86_PAE 2732 select GPIOLIB 2733 select OF 2734 select OF_PROMTREE 2735 select IRQ_DOMAIN 2736 select OLPC_EC 2737 ---help--- 2738 Add support for detecting the unique features of the OLPC 2739 XO hardware. 2740 2741config OLPC_XO1_PM 2742 bool "OLPC XO-1 Power Management" 2743 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2744 ---help--- 2745 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2746 2747config OLPC_XO1_RTC 2748 bool "OLPC XO-1 Real Time Clock" 2749 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2750 ---help--- 2751 Add support for the XO-1 real time clock, which can be used as a 2752 programmable wakeup source. 2753 2754config OLPC_XO1_SCI 2755 bool "OLPC XO-1 SCI extras" 2756 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2757 depends on INPUT=y 2758 select POWER_SUPPLY 2759 ---help--- 2760 Add support for SCI-based features of the OLPC XO-1 laptop: 2761 - EC-driven system wakeups 2762 - Power button 2763 - Ebook switch 2764 - Lid switch 2765 - AC adapter status updates 2766 - Battery status updates 2767 2768config OLPC_XO15_SCI 2769 bool "OLPC XO-1.5 SCI extras" 2770 depends on OLPC && ACPI 2771 select POWER_SUPPLY 2772 ---help--- 2773 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2774 - EC-driven system wakeups 2775 - AC adapter status updates 2776 - Battery status updates 2777 2778config ALIX 2779 bool "PCEngines ALIX System Support (LED setup)" 2780 select GPIOLIB 2781 ---help--- 2782 This option enables system support for the PCEngines ALIX. 2783 At present this just sets up LEDs for GPIO control on 2784 ALIX2/3/6 boards. However, other system specific setup should 2785 get added here. 2786 2787 Note: You must still enable the drivers for GPIO and LED support 2788 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2789 2790 Note: You have to set alix.force=1 for boards with Award BIOS. 2791 2792config NET5501 2793 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2794 select GPIOLIB 2795 ---help--- 2796 This option enables system support for the Soekris Engineering net5501. 2797 2798config GEOS 2799 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2800 select GPIOLIB 2801 depends on DMI 2802 ---help--- 2803 This option enables system support for the Traverse Technologies GEOS. 2804 2805config TS5500 2806 bool "Technologic Systems TS-5500 platform support" 2807 depends on MELAN 2808 select CHECK_SIGNATURE 2809 select NEW_LEDS 2810 select LEDS_CLASS 2811 ---help--- 2812 This option enables system support for the Technologic Systems TS-5500. 2813 2814endif # X86_32 2815 2816config AMD_NB 2817 def_bool y 2818 depends on CPU_SUP_AMD && PCI 2819 2820config X86_SYSFB 2821 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2822 help 2823 Firmwares often provide initial graphics framebuffers so the BIOS, 2824 bootloader or kernel can show basic video-output during boot for 2825 user-guidance and debugging. Historically, x86 used the VESA BIOS 2826 Extensions and EFI-framebuffers for this, which are mostly limited 2827 to x86. 2828 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2829 framebuffers so the new generic system-framebuffer drivers can be 2830 used on x86. If the framebuffer is not compatible with the generic 2831 modes, it is advertised as fallback platform framebuffer so legacy 2832 drivers like efifb, vesafb and uvesafb can pick it up. 2833 If this option is not selected, all system framebuffers are always 2834 marked as fallback platform framebuffers as usual. 2835 2836 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2837 not be able to pick up generic system framebuffers if this option 2838 is selected. You are highly encouraged to enable simplefb as 2839 replacement if you select this option. simplefb can correctly deal 2840 with generic system framebuffers. But you should still keep vesafb 2841 and others enabled as fallback if a system framebuffer is 2842 incompatible with simplefb. 2843 2844 If unsure, say Y. 2845 2846endmenu 2847 2848 2849menu "Binary Emulations" 2850 2851config IA32_EMULATION 2852 bool "IA32 Emulation" 2853 depends on X86_64 2854 select ARCH_WANT_OLD_COMPAT_IPC 2855 select BINFMT_ELF 2856 select COMPAT_BINFMT_ELF 2857 select COMPAT_OLD_SIGACTION 2858 ---help--- 2859 Include code to run legacy 32-bit programs under a 2860 64-bit kernel. You should likely turn this on, unless you're 2861 100% sure that you don't have any 32-bit programs left. 2862 2863config IA32_AOUT 2864 tristate "IA32 a.out support" 2865 depends on IA32_EMULATION 2866 depends on BROKEN 2867 ---help--- 2868 Support old a.out binaries in the 32bit emulation. 2869 2870config X86_X32 2871 bool "x32 ABI for 64-bit mode" 2872 depends on X86_64 2873 ---help--- 2874 Include code to run binaries for the x32 native 32-bit ABI 2875 for 64-bit processors. An x32 process gets access to the 2876 full 64-bit register file and wide data path while leaving 2877 pointers at 32 bits for smaller memory footprint. 2878 2879 You will need a recent binutils (2.22 or later) with 2880 elf32_x86_64 support enabled to compile a kernel with this 2881 option set. 2882 2883config COMPAT_32 2884 def_bool y 2885 depends on IA32_EMULATION || X86_32 2886 select HAVE_UID16 2887 select OLD_SIGSUSPEND3 2888 2889config COMPAT 2890 def_bool y 2891 depends on IA32_EMULATION || X86_X32 2892 2893if COMPAT 2894config COMPAT_FOR_U64_ALIGNMENT 2895 def_bool y 2896 2897config SYSVIPC_COMPAT 2898 def_bool y 2899 depends on SYSVIPC 2900endif 2901 2902endmenu 2903 2904 2905config HAVE_ATOMIC_IOMAP 2906 def_bool y 2907 depends on X86_32 2908 2909config X86_DEV_DMA_OPS 2910 bool 2911 2912source "drivers/firmware/Kconfig" 2913 2914source "arch/x86/kvm/Kconfig" 2915