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_AOUT 18 select HAVE_GENERIC_DMA_COHERENT 19 select MODULES_USE_ELF_REL 20 select OLD_SIGACTION 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 if (MEMORY_ISOLATION && COMPACTION) || CMA 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 X86_DEV_DMA_OPS 34 select ARCH_HAS_SYSCALL_WRAPPER 35 36# 37# Arch settings 38# 39# ( Note that options that are marked 'if X86_64' could in principle be 40# ported to 32-bit as well. ) 41# 42config X86 43 def_bool y 44 # 45 # Note: keep this list sorted alphabetically 46 # 47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 49 select ANON_INODES 50 select ARCH_CLOCKSOURCE_DATA 51 select ARCH_CLOCKSOURCE_INIT 52 select ARCH_DISCARD_MEMBLOCK 53 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 54 select ARCH_HAS_DEBUG_VIRTUAL 55 select ARCH_HAS_DEVMEM_IS_ALLOWED 56 select ARCH_HAS_ELF_RANDOMIZE 57 select ARCH_HAS_FAST_MULTIPLIER 58 select ARCH_HAS_FILTER_PGPROT 59 select ARCH_HAS_FORTIFY_SOURCE 60 select ARCH_HAS_GCOV_PROFILE_ALL 61 select ARCH_HAS_KCOV if X86_64 62 select ARCH_HAS_MEMBARRIER_SYNC_CORE 63 select ARCH_HAS_PMEM_API if X86_64 64 select ARCH_HAS_PTE_SPECIAL 65 select ARCH_HAS_REFCOUNT 66 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 67 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 68 select ARCH_HAS_SET_MEMORY 69 select ARCH_HAS_SG_CHAIN 70 select ARCH_HAS_STRICT_KERNEL_RWX 71 select ARCH_HAS_STRICT_MODULE_RWX 72 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 73 select ARCH_HAS_UBSAN_SANITIZE_ALL 74 select ARCH_HAS_ZONE_DEVICE if X86_64 75 select ARCH_HAVE_NMI_SAFE_CMPXCHG 76 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 77 select ARCH_MIGHT_HAVE_PC_PARPORT 78 select ARCH_MIGHT_HAVE_PC_SERIO 79 select ARCH_SUPPORTS_ACPI 80 select ARCH_SUPPORTS_ATOMIC_RMW 81 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 82 select ARCH_USE_BUILTIN_BSWAP 83 select ARCH_USE_QUEUED_RWLOCKS 84 select ARCH_USE_QUEUED_SPINLOCKS 85 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 86 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 87 select ARCH_WANTS_THP_SWAP if X86_64 88 select BUILDTIME_EXTABLE_SORT 89 select CLKEVT_I8253 90 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 91 select CLOCKSOURCE_WATCHDOG 92 select DCACHE_WORD_ACCESS 93 select DMA_DIRECT_OPS 94 select EDAC_ATOMIC_SCRUB 95 select EDAC_SUPPORT 96 select GENERIC_CLOCKEVENTS 97 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 98 select GENERIC_CLOCKEVENTS_MIN_ADJUST 99 select GENERIC_CMOS_UPDATE 100 select GENERIC_CPU_AUTOPROBE 101 select GENERIC_CPU_VULNERABILITIES 102 select GENERIC_EARLY_IOREMAP 103 select GENERIC_FIND_FIRST_BIT 104 select GENERIC_IOMAP 105 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 106 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 107 select GENERIC_IRQ_MIGRATION if SMP 108 select GENERIC_IRQ_PROBE 109 select GENERIC_IRQ_RESERVATION_MODE 110 select GENERIC_IRQ_SHOW 111 select GENERIC_PENDING_IRQ if SMP 112 select GENERIC_SMP_IDLE_THREAD 113 select GENERIC_STRNCPY_FROM_USER 114 select GENERIC_STRNLEN_USER 115 select GENERIC_TIME_VSYSCALL 116 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 117 select HAVE_ACPI_APEI if ACPI 118 select HAVE_ACPI_APEI_NMI if ACPI 119 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 120 select HAVE_ARCH_AUDITSYSCALL 121 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 122 select HAVE_ARCH_JUMP_LABEL 123 select HAVE_ARCH_JUMP_LABEL_RELATIVE 124 select HAVE_ARCH_KASAN if X86_64 125 select HAVE_ARCH_KGDB 126 select HAVE_ARCH_MMAP_RND_BITS if MMU 127 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 128 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 129 select HAVE_ARCH_PREL32_RELOCATIONS 130 select HAVE_ARCH_SECCOMP_FILTER 131 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 132 select HAVE_ARCH_STACKLEAK 133 select HAVE_ARCH_TRACEHOOK 134 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 135 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 136 select HAVE_ARCH_VMAP_STACK if X86_64 137 select HAVE_ARCH_WITHIN_STACK_FRAMES 138 select HAVE_CMPXCHG_DOUBLE 139 select HAVE_CMPXCHG_LOCAL 140 select HAVE_CONTEXT_TRACKING if X86_64 141 select HAVE_COPY_THREAD_TLS 142 select HAVE_C_RECORDMCOUNT 143 select HAVE_DEBUG_KMEMLEAK 144 select HAVE_DEBUG_STACKOVERFLOW 145 select HAVE_DMA_CONTIGUOUS 146 select HAVE_DYNAMIC_FTRACE 147 select HAVE_DYNAMIC_FTRACE_WITH_REGS 148 select HAVE_EBPF_JIT 149 select HAVE_EFFICIENT_UNALIGNED_ACCESS 150 select HAVE_EXIT_THREAD 151 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 152 select HAVE_FTRACE_MCOUNT_RECORD 153 select HAVE_FUNCTION_GRAPH_TRACER 154 select HAVE_FUNCTION_TRACER 155 select HAVE_GCC_PLUGINS 156 select HAVE_HW_BREAKPOINT 157 select HAVE_IDE 158 select HAVE_IOREMAP_PROT 159 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 160 select HAVE_IRQ_TIME_ACCOUNTING 161 select HAVE_KERNEL_BZIP2 162 select HAVE_KERNEL_GZIP 163 select HAVE_KERNEL_LZ4 164 select HAVE_KERNEL_LZMA 165 select HAVE_KERNEL_LZO 166 select HAVE_KERNEL_XZ 167 select HAVE_KPROBES 168 select HAVE_KPROBES_ON_FTRACE 169 select HAVE_FUNCTION_ERROR_INJECTION 170 select HAVE_KRETPROBES 171 select HAVE_KVM 172 select HAVE_LIVEPATCH if X86_64 173 select HAVE_MEMBLOCK_NODE_MAP 174 select HAVE_MIXED_BREAKPOINTS_REGS 175 select HAVE_MOD_ARCH_SPECIFIC 176 select HAVE_NMI 177 select HAVE_OPROFILE 178 select HAVE_OPTPROBES 179 select HAVE_PCSPKR_PLATFORM 180 select HAVE_PERF_EVENTS 181 select HAVE_PERF_EVENTS_NMI 182 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 183 select HAVE_PERF_REGS 184 select HAVE_PERF_USER_STACK_DUMP 185 select HAVE_RCU_TABLE_FREE if PARAVIRT 186 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 187 select HAVE_REGS_AND_STACK_ACCESS_API 188 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 189 select HAVE_FUNCTION_ARG_ACCESS_API 190 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 191 select HAVE_STACK_VALIDATION if X86_64 192 select HAVE_RSEQ 193 select HAVE_SYSCALL_TRACEPOINTS 194 select HAVE_UNSTABLE_SCHED_CLOCK 195 select HAVE_USER_RETURN_NOTIFIER 196 select HOTPLUG_SMT if SMP 197 select IRQ_FORCED_THREADING 198 select NEED_SG_DMA_LENGTH 199 select PCI_LOCKLESS_CONFIG 200 select PERF_EVENTS 201 select RTC_LIB 202 select RTC_MC146818_LIB 203 select SPARSE_IRQ 204 select SRCU 205 select SYSCTL_EXCEPTION_TRACE 206 select THREAD_INFO_IN_TASK 207 select USER_STACKTRACE_SUPPORT 208 select VIRT_TO_BUS 209 select X86_FEATURE_NAMES if PROC_FS 210 211config INSTRUCTION_DECODER 212 def_bool y 213 depends on KPROBES || PERF_EVENTS || UPROBES 214 215config OUTPUT_FORMAT 216 string 217 default "elf32-i386" if X86_32 218 default "elf64-x86-64" if X86_64 219 220config ARCH_DEFCONFIG 221 string 222 default "arch/x86/configs/i386_defconfig" if X86_32 223 default "arch/x86/configs/x86_64_defconfig" if X86_64 224 225config LOCKDEP_SUPPORT 226 def_bool y 227 228config STACKTRACE_SUPPORT 229 def_bool y 230 231config MMU 232 def_bool y 233 234config ARCH_MMAP_RND_BITS_MIN 235 default 28 if 64BIT 236 default 8 237 238config ARCH_MMAP_RND_BITS_MAX 239 default 32 if 64BIT 240 default 16 241 242config ARCH_MMAP_RND_COMPAT_BITS_MIN 243 default 8 244 245config ARCH_MMAP_RND_COMPAT_BITS_MAX 246 default 16 247 248config SBUS 249 bool 250 251config GENERIC_ISA_DMA 252 def_bool y 253 depends on ISA_DMA_API 254 255config GENERIC_BUG 256 def_bool y 257 depends on BUG 258 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 259 260config GENERIC_BUG_RELATIVE_POINTERS 261 bool 262 263config GENERIC_HWEIGHT 264 def_bool y 265 266config ARCH_MAY_HAVE_PC_FDC 267 def_bool y 268 depends on ISA_DMA_API 269 270config RWSEM_XCHGADD_ALGORITHM 271 def_bool y 272 273config GENERIC_CALIBRATE_DELAY 274 def_bool y 275 276config ARCH_HAS_CPU_RELAX 277 def_bool y 278 279config ARCH_HAS_CACHE_LINE_SIZE 280 def_bool y 281 282config ARCH_HAS_FILTER_PGPROT 283 def_bool y 284 285config HAVE_SETUP_PER_CPU_AREA 286 def_bool y 287 288config NEED_PER_CPU_EMBED_FIRST_CHUNK 289 def_bool y 290 291config NEED_PER_CPU_PAGE_FIRST_CHUNK 292 def_bool y 293 294config ARCH_HIBERNATION_POSSIBLE 295 def_bool y 296 297config ARCH_SUSPEND_POSSIBLE 298 def_bool y 299 300config ARCH_WANT_HUGE_PMD_SHARE 301 def_bool y 302 303config ARCH_WANT_GENERAL_HUGETLB 304 def_bool y 305 306config ZONE_DMA32 307 def_bool y if X86_64 308 309config AUDIT_ARCH 310 def_bool y if X86_64 311 312config ARCH_SUPPORTS_OPTIMIZED_INLINING 313 def_bool y 314 315config ARCH_SUPPORTS_DEBUG_PAGEALLOC 316 def_bool y 317 318config KASAN_SHADOW_OFFSET 319 hex 320 depends on KASAN 321 default 0xdffffc0000000000 322 323config HAVE_INTEL_TXT 324 def_bool y 325 depends on INTEL_IOMMU && ACPI 326 327config X86_32_SMP 328 def_bool y 329 depends on X86_32 && SMP 330 331config X86_64_SMP 332 def_bool y 333 depends on X86_64 && SMP 334 335config X86_32_LAZY_GS 336 def_bool y 337 depends on X86_32 && !STACKPROTECTOR 338 339config ARCH_SUPPORTS_UPROBES 340 def_bool y 341 342config FIX_EARLYCON_MEM 343 def_bool y 344 345config DYNAMIC_PHYSICAL_MASK 346 bool 347 348config PGTABLE_LEVELS 349 int 350 default 5 if X86_5LEVEL 351 default 4 if X86_64 352 default 3 if X86_PAE 353 default 2 354 355config CC_HAS_SANE_STACKPROTECTOR 356 bool 357 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 358 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 359 help 360 We have to make sure stack protector is unconditionally disabled if 361 the compiler produces broken code. 362 363menu "Processor type and features" 364 365config ZONE_DMA 366 bool "DMA memory allocation support" if EXPERT 367 default y 368 help 369 DMA memory allocation support allows devices with less than 32-bit 370 addressing to allocate within the first 16MB of address space. 371 Disable if no such devices will be used. 372 373 If unsure, say Y. 374 375config SMP 376 bool "Symmetric multi-processing support" 377 ---help--- 378 This enables support for systems with more than one CPU. If you have 379 a system with only one CPU, say N. If you have a system with more 380 than one CPU, say Y. 381 382 If you say N here, the kernel will run on uni- and multiprocessor 383 machines, but will use only one CPU of a multiprocessor machine. If 384 you say Y here, the kernel will run on many, but not all, 385 uniprocessor machines. On a uniprocessor machine, the kernel 386 will run faster if you say N here. 387 388 Note that if you say Y here and choose architecture "586" or 389 "Pentium" under "Processor family", the kernel will not work on 486 390 architectures. Similarly, multiprocessor kernels for the "PPro" 391 architecture may not work on all Pentium based boards. 392 393 People using multiprocessor machines who say Y here should also say 394 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 395 Management" code will be disabled if you say Y here. 396 397 See also <file:Documentation/x86/i386/IO-APIC.txt>, 398 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 399 <http://www.tldp.org/docs.html#howto>. 400 401 If you don't know what to do here, say N. 402 403config X86_FEATURE_NAMES 404 bool "Processor feature human-readable names" if EMBEDDED 405 default y 406 ---help--- 407 This option compiles in a table of x86 feature bits and corresponding 408 names. This is required to support /proc/cpuinfo and a few kernel 409 messages. You can disable this to save space, at the expense of 410 making those few kernel messages show numeric feature bits instead. 411 412 If in doubt, say Y. 413 414config X86_X2APIC 415 bool "Support x2apic" 416 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 417 ---help--- 418 This enables x2apic support on CPUs that have this feature. 419 420 This allows 32-bit apic IDs (so it can support very large systems), 421 and accesses the local apic via MSRs not via mmio. 422 423 If you don't know what to do here, say N. 424 425config X86_MPPARSE 426 bool "Enable MPS table" if ACPI || SFI 427 default y 428 depends on X86_LOCAL_APIC 429 ---help--- 430 For old smp systems that do not have proper acpi support. Newer systems 431 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 432 433config GOLDFISH 434 def_bool y 435 depends on X86_GOLDFISH 436 437config RETPOLINE 438 bool "Avoid speculative indirect branches in kernel" 439 default y 440 select STACK_VALIDATION if HAVE_STACK_VALIDATION 441 help 442 Compile kernel with the retpoline compiler options to guard against 443 kernel-to-user data leaks by avoiding speculative indirect 444 branches. Requires a compiler with -mindirect-branch=thunk-extern 445 support for full protection. The kernel may run slower. 446 447config INTEL_RDT 448 bool "Intel Resource Director Technology support" 449 depends on X86 && CPU_SUP_INTEL 450 select KERNFS 451 help 452 Select to enable resource allocation and monitoring which are 453 sub-features of Intel Resource Director Technology(RDT). More 454 information about RDT can be found in the Intel x86 455 Architecture Software Developer Manual. 456 457 Say N if unsure. 458 459if X86_32 460config X86_BIGSMP 461 bool "Support for big SMP systems with more than 8 CPUs" 462 depends on SMP 463 ---help--- 464 This option is needed for the systems that have more than 8 CPUs 465 466config X86_EXTENDED_PLATFORM 467 bool "Support for extended (non-PC) x86 platforms" 468 default y 469 ---help--- 470 If you disable this option then the kernel will only support 471 standard PC platforms. (which covers the vast majority of 472 systems out there.) 473 474 If you enable this option then you'll be able to select support 475 for the following (non-PC) 32 bit x86 platforms: 476 Goldfish (Android emulator) 477 AMD Elan 478 RDC R-321x SoC 479 SGI 320/540 (Visual Workstation) 480 STA2X11-based (e.g. Northville) 481 Moorestown MID devices 482 483 If you have one of these systems, or if you want to build a 484 generic distribution kernel, say Y here - otherwise say N. 485endif 486 487if X86_64 488config X86_EXTENDED_PLATFORM 489 bool "Support for extended (non-PC) x86 platforms" 490 default y 491 ---help--- 492 If you disable this option then the kernel will only support 493 standard PC platforms. (which covers the vast majority of 494 systems out there.) 495 496 If you enable this option then you'll be able to select support 497 for the following (non-PC) 64 bit x86 platforms: 498 Numascale NumaChip 499 ScaleMP vSMP 500 SGI Ultraviolet 501 502 If you have one of these systems, or if you want to build a 503 generic distribution kernel, say Y here - otherwise say N. 504endif 505# This is an alphabetically sorted list of 64 bit extended platforms 506# Please maintain the alphabetic order if and when there are additions 507config X86_NUMACHIP 508 bool "Numascale NumaChip" 509 depends on X86_64 510 depends on X86_EXTENDED_PLATFORM 511 depends on NUMA 512 depends on SMP 513 depends on X86_X2APIC 514 depends on PCI_MMCONFIG 515 ---help--- 516 Adds support for Numascale NumaChip large-SMP systems. Needed to 517 enable more than ~168 cores. 518 If you don't have one of these, you should say N here. 519 520config X86_VSMP 521 bool "ScaleMP vSMP" 522 select HYPERVISOR_GUEST 523 select PARAVIRT 524 depends on X86_64 && PCI 525 depends on X86_EXTENDED_PLATFORM 526 depends on SMP 527 ---help--- 528 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 529 supposed to run on these EM64T-based machines. Only choose this option 530 if you have one of these machines. 531 532config X86_UV 533 bool "SGI Ultraviolet" 534 depends on X86_64 535 depends on X86_EXTENDED_PLATFORM 536 depends on NUMA 537 depends on EFI 538 depends on X86_X2APIC 539 depends on PCI 540 ---help--- 541 This option is needed in order to support SGI Ultraviolet systems. 542 If you don't have one of these, you should say N here. 543 544# Following is an alphabetically sorted list of 32 bit extended platforms 545# Please maintain the alphabetic order if and when there are additions 546 547config X86_GOLDFISH 548 bool "Goldfish (Virtual Platform)" 549 depends on X86_EXTENDED_PLATFORM 550 ---help--- 551 Enable support for the Goldfish virtual platform used primarily 552 for Android development. Unless you are building for the Android 553 Goldfish emulator say N here. 554 555config X86_INTEL_CE 556 bool "CE4100 TV platform" 557 depends on PCI 558 depends on PCI_GODIRECT 559 depends on X86_IO_APIC 560 depends on X86_32 561 depends on X86_EXTENDED_PLATFORM 562 select X86_REBOOTFIXUPS 563 select OF 564 select OF_EARLY_FLATTREE 565 ---help--- 566 Select for the Intel CE media processor (CE4100) SOC. 567 This option compiles in support for the CE4100 SOC for settop 568 boxes and media devices. 569 570config X86_INTEL_MID 571 bool "Intel MID platform support" 572 depends on X86_EXTENDED_PLATFORM 573 depends on X86_PLATFORM_DEVICES 574 depends on PCI 575 depends on X86_64 || (PCI_GOANY && X86_32) 576 depends on X86_IO_APIC 577 select SFI 578 select I2C 579 select DW_APB_TIMER 580 select APB_TIMER 581 select INTEL_SCU_IPC 582 select MFD_INTEL_MSIC 583 ---help--- 584 Select to build a kernel capable of supporting Intel MID (Mobile 585 Internet Device) platform systems which do not have the PCI legacy 586 interfaces. If you are building for a PC class system say N here. 587 588 Intel MID platforms are based on an Intel processor and chipset which 589 consume less power than most of the x86 derivatives. 590 591config X86_INTEL_QUARK 592 bool "Intel Quark platform support" 593 depends on X86_32 594 depends on X86_EXTENDED_PLATFORM 595 depends on X86_PLATFORM_DEVICES 596 depends on X86_TSC 597 depends on PCI 598 depends on PCI_GOANY 599 depends on X86_IO_APIC 600 select IOSF_MBI 601 select INTEL_IMR 602 select COMMON_CLK 603 ---help--- 604 Select to include support for Quark X1000 SoC. 605 Say Y here if you have a Quark based system such as the Arduino 606 compatible Intel Galileo. 607 608config X86_INTEL_LPSS 609 bool "Intel Low Power Subsystem Support" 610 depends on X86 && ACPI 611 select COMMON_CLK 612 select PINCTRL 613 select IOSF_MBI 614 ---help--- 615 Select to build support for Intel Low Power Subsystem such as 616 found on Intel Lynxpoint PCH. Selecting this option enables 617 things like clock tree (common clock framework) and pincontrol 618 which are needed by the LPSS peripheral drivers. 619 620config X86_AMD_PLATFORM_DEVICE 621 bool "AMD ACPI2Platform devices support" 622 depends on ACPI 623 select COMMON_CLK 624 select PINCTRL 625 ---help--- 626 Select to interpret AMD specific ACPI device to platform device 627 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 628 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 629 implemented under PINCTRL subsystem. 630 631config IOSF_MBI 632 tristate "Intel SoC IOSF Sideband support for SoC platforms" 633 depends on PCI 634 ---help--- 635 This option enables sideband register access support for Intel SoC 636 platforms. On these platforms the IOSF sideband is used in lieu of 637 MSR's for some register accesses, mostly but not limited to thermal 638 and power. Drivers may query the availability of this device to 639 determine if they need the sideband in order to work on these 640 platforms. The sideband is available on the following SoC products. 641 This list is not meant to be exclusive. 642 - BayTrail 643 - Braswell 644 - Quark 645 646 You should say Y if you are running a kernel on one of these SoC's. 647 648config IOSF_MBI_DEBUG 649 bool "Enable IOSF sideband access through debugfs" 650 depends on IOSF_MBI && DEBUG_FS 651 ---help--- 652 Select this option to expose the IOSF sideband access registers (MCR, 653 MDR, MCRX) through debugfs to write and read register information from 654 different units on the SoC. This is most useful for obtaining device 655 state information for debug and analysis. As this is a general access 656 mechanism, users of this option would have specific knowledge of the 657 device they want to access. 658 659 If you don't require the option or are in doubt, say N. 660 661config X86_RDC321X 662 bool "RDC R-321x SoC" 663 depends on X86_32 664 depends on X86_EXTENDED_PLATFORM 665 select M486 666 select X86_REBOOTFIXUPS 667 ---help--- 668 This option is needed for RDC R-321x system-on-chip, also known 669 as R-8610-(G). 670 If you don't have one of these chips, you should say N here. 671 672config X86_32_NON_STANDARD 673 bool "Support non-standard 32-bit SMP architectures" 674 depends on X86_32 && SMP 675 depends on X86_EXTENDED_PLATFORM 676 ---help--- 677 This option compiles in the bigsmp and STA2X11 default 678 subarchitectures. It is intended for a generic binary 679 kernel. If you select them all, kernel will probe it one by 680 one and will fallback to default. 681 682# Alphabetically sorted list of Non standard 32 bit platforms 683 684config X86_SUPPORTS_MEMORY_FAILURE 685 def_bool y 686 # MCE code calls memory_failure(): 687 depends on X86_MCE 688 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 689 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 690 depends on X86_64 || !SPARSEMEM 691 select ARCH_SUPPORTS_MEMORY_FAILURE 692 693config STA2X11 694 bool "STA2X11 Companion Chip Support" 695 depends on X86_32_NON_STANDARD && PCI 696 select ARCH_HAS_PHYS_TO_DMA 697 select X86_DEV_DMA_OPS 698 select X86_DMA_REMAP 699 select SWIOTLB 700 select MFD_STA2X11 701 select GPIOLIB 702 ---help--- 703 This adds support for boards based on the STA2X11 IO-Hub, 704 a.k.a. "ConneXt". The chip is used in place of the standard 705 PC chipset, so all "standard" peripherals are missing. If this 706 option is selected the kernel will still be able to boot on 707 standard PC machines. 708 709config X86_32_IRIS 710 tristate "Eurobraille/Iris poweroff module" 711 depends on X86_32 712 ---help--- 713 The Iris machines from EuroBraille do not have APM or ACPI support 714 to shut themselves down properly. A special I/O sequence is 715 needed to do so, which is what this module does at 716 kernel shutdown. 717 718 This is only for Iris machines from EuroBraille. 719 720 If unused, say N. 721 722config SCHED_OMIT_FRAME_POINTER 723 def_bool y 724 prompt "Single-depth WCHAN output" 725 depends on X86 726 ---help--- 727 Calculate simpler /proc/<PID>/wchan values. If this option 728 is disabled then wchan values will recurse back to the 729 caller function. This provides more accurate wchan values, 730 at the expense of slightly more scheduling overhead. 731 732 If in doubt, say "Y". 733 734menuconfig HYPERVISOR_GUEST 735 bool "Linux guest support" 736 ---help--- 737 Say Y here to enable options for running Linux under various hyper- 738 visors. This option enables basic hypervisor detection and platform 739 setup. 740 741 If you say N, all options in this submenu will be skipped and 742 disabled, and Linux guest support won't be built in. 743 744if HYPERVISOR_GUEST 745 746config PARAVIRT 747 bool "Enable paravirtualization code" 748 ---help--- 749 This changes the kernel so it can modify itself when it is run 750 under a hypervisor, potentially improving performance significantly 751 over full virtualization. However, when run without a hypervisor 752 the kernel is theoretically slower and slightly larger. 753 754config PARAVIRT_XXL 755 bool 756 757config PARAVIRT_DEBUG 758 bool "paravirt-ops debugging" 759 depends on PARAVIRT && DEBUG_KERNEL 760 ---help--- 761 Enable to debug paravirt_ops internals. Specifically, BUG if 762 a paravirt_op is missing when it is called. 763 764config PARAVIRT_SPINLOCKS 765 bool "Paravirtualization layer for spinlocks" 766 depends on PARAVIRT && SMP 767 ---help--- 768 Paravirtualized spinlocks allow a pvops backend to replace the 769 spinlock implementation with something virtualization-friendly 770 (for example, block the virtual CPU rather than spinning). 771 772 It has a minimal impact on native kernels and gives a nice performance 773 benefit on paravirtualized KVM / Xen kernels. 774 775 If you are unsure how to answer this question, answer Y. 776 777config QUEUED_LOCK_STAT 778 bool "Paravirt queued spinlock statistics" 779 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 780 ---help--- 781 Enable the collection of statistical data on the slowpath 782 behavior of paravirtualized queued spinlocks and report 783 them on debugfs. 784 785source "arch/x86/xen/Kconfig" 786 787config KVM_GUEST 788 bool "KVM Guest support (including kvmclock)" 789 depends on PARAVIRT 790 select PARAVIRT_CLOCK 791 default y 792 ---help--- 793 This option enables various optimizations for running under the KVM 794 hypervisor. It includes a paravirtualized clock, so that instead 795 of relying on a PIT (or probably other) emulation by the 796 underlying device model, the host provides the guest with 797 timing infrastructure such as time of day, and system time 798 799config KVM_DEBUG_FS 800 bool "Enable debug information for KVM Guests in debugfs" 801 depends on KVM_GUEST && DEBUG_FS 802 ---help--- 803 This option enables collection of various statistics for KVM guest. 804 Statistics are displayed in debugfs filesystem. Enabling this option 805 may incur significant overhead. 806 807config PARAVIRT_TIME_ACCOUNTING 808 bool "Paravirtual steal time accounting" 809 depends on PARAVIRT 810 ---help--- 811 Select this option to enable fine granularity task steal time 812 accounting. Time spent executing other tasks in parallel with 813 the current vCPU is discounted from the vCPU power. To account for 814 that, there can be a small performance impact. 815 816 If in doubt, say N here. 817 818config PARAVIRT_CLOCK 819 bool 820 821config JAILHOUSE_GUEST 822 bool "Jailhouse non-root cell support" 823 depends on X86_64 && PCI 824 select X86_PM_TIMER 825 ---help--- 826 This option allows to run Linux as guest in a Jailhouse non-root 827 cell. You can leave this option disabled if you only want to start 828 Jailhouse and run Linux afterwards in the root cell. 829 830endif #HYPERVISOR_GUEST 831 832source "arch/x86/Kconfig.cpu" 833 834config HPET_TIMER 835 def_bool X86_64 836 prompt "HPET Timer Support" if X86_32 837 ---help--- 838 Use the IA-PC HPET (High Precision Event Timer) to manage 839 time in preference to the PIT and RTC, if a HPET is 840 present. 841 HPET is the next generation timer replacing legacy 8254s. 842 The HPET provides a stable time base on SMP 843 systems, unlike the TSC, but it is more expensive to access, 844 as it is off-chip. The interface used is documented 845 in the HPET spec, revision 1. 846 847 You can safely choose Y here. However, HPET will only be 848 activated if the platform and the BIOS support this feature. 849 Otherwise the 8254 will be used for timing services. 850 851 Choose N to continue using the legacy 8254 timer. 852 853config HPET_EMULATE_RTC 854 def_bool y 855 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 856 857config APB_TIMER 858 def_bool y if X86_INTEL_MID 859 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 860 select DW_APB_TIMER 861 depends on X86_INTEL_MID && SFI 862 help 863 APB timer is the replacement for 8254, HPET on X86 MID platforms. 864 The APBT provides a stable time base on SMP 865 systems, unlike the TSC, but it is more expensive to access, 866 as it is off-chip. APB timers are always running regardless of CPU 867 C states, they are used as per CPU clockevent device when possible. 868 869# Mark as expert because too many people got it wrong. 870# The code disables itself when not needed. 871config DMI 872 default y 873 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 874 bool "Enable DMI scanning" if EXPERT 875 ---help--- 876 Enabled scanning of DMI to identify machine quirks. Say Y 877 here unless you have verified that your setup is not 878 affected by entries in the DMI blacklist. Required by PNP 879 BIOS code. 880 881config GART_IOMMU 882 bool "Old AMD GART IOMMU support" 883 select IOMMU_HELPER 884 select SWIOTLB 885 depends on X86_64 && PCI && AMD_NB 886 ---help--- 887 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 888 GART based hardware IOMMUs. 889 890 The GART supports full DMA access for devices with 32-bit access 891 limitations, on systems with more than 3 GB. This is usually needed 892 for USB, sound, many IDE/SATA chipsets and some other devices. 893 894 Newer systems typically have a modern AMD IOMMU, supported via 895 the CONFIG_AMD_IOMMU=y config option. 896 897 In normal configurations this driver is only active when needed: 898 there's more than 3 GB of memory and the system contains a 899 32-bit limited device. 900 901 If unsure, say Y. 902 903config CALGARY_IOMMU 904 bool "IBM Calgary IOMMU support" 905 select IOMMU_HELPER 906 select SWIOTLB 907 depends on X86_64 && PCI 908 ---help--- 909 Support for hardware IOMMUs in IBM's xSeries x366 and x460 910 systems. Needed to run systems with more than 3GB of memory 911 properly with 32-bit PCI devices that do not support DAC 912 (Double Address Cycle). Calgary also supports bus level 913 isolation, where all DMAs pass through the IOMMU. This 914 prevents them from going anywhere except their intended 915 destination. This catches hard-to-find kernel bugs and 916 mis-behaving drivers and devices that do not use the DMA-API 917 properly to set up their DMA buffers. The IOMMU can be 918 turned off at boot time with the iommu=off parameter. 919 Normally the kernel will make the right choice by itself. 920 If unsure, say Y. 921 922config CALGARY_IOMMU_ENABLED_BY_DEFAULT 923 def_bool y 924 prompt "Should Calgary be enabled by default?" 925 depends on CALGARY_IOMMU 926 ---help--- 927 Should Calgary be enabled by default? if you choose 'y', Calgary 928 will be used (if it exists). If you choose 'n', Calgary will not be 929 used even if it exists. If you choose 'n' and would like to use 930 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 931 If unsure, say Y. 932 933config MAXSMP 934 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 935 depends on X86_64 && SMP && DEBUG_KERNEL 936 select CPUMASK_OFFSTACK 937 ---help--- 938 Enable maximum number of CPUS and NUMA Nodes for this architecture. 939 If unsure, say N. 940 941# 942# The maximum number of CPUs supported: 943# 944# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 945# and which can be configured interactively in the 946# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 947# 948# The ranges are different on 32-bit and 64-bit kernels, depending on 949# hardware capabilities and scalability features of the kernel. 950# 951# ( If MAXSMP is enabled we just use the highest possible value and disable 952# interactive configuration. ) 953# 954 955config NR_CPUS_RANGE_BEGIN 956 int 957 default NR_CPUS_RANGE_END if MAXSMP 958 default 1 if !SMP 959 default 2 960 961config NR_CPUS_RANGE_END 962 int 963 depends on X86_32 964 default 64 if SMP && X86_BIGSMP 965 default 8 if SMP && !X86_BIGSMP 966 default 1 if !SMP 967 968config NR_CPUS_RANGE_END 969 int 970 depends on X86_64 971 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 972 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 973 default 1 if !SMP 974 975config NR_CPUS_DEFAULT 976 int 977 depends on X86_32 978 default 32 if X86_BIGSMP 979 default 8 if SMP 980 default 1 if !SMP 981 982config NR_CPUS_DEFAULT 983 int 984 depends on X86_64 985 default 8192 if MAXSMP 986 default 64 if SMP 987 default 1 if !SMP 988 989config NR_CPUS 990 int "Maximum number of CPUs" if SMP && !MAXSMP 991 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 992 default NR_CPUS_DEFAULT 993 ---help--- 994 This allows you to specify the maximum number of CPUs which this 995 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 996 supported value is 8192, otherwise the maximum value is 512. The 997 minimum value which makes sense is 2. 998 999 This is purely to save memory: each supported CPU adds about 8KB 1000 to the kernel image. 1001 1002config SCHED_SMT 1003 def_bool y if SMP 1004 1005config SCHED_MC 1006 def_bool y 1007 prompt "Multi-core scheduler support" 1008 depends on SMP 1009 ---help--- 1010 Multi-core scheduler support improves the CPU scheduler's decision 1011 making when dealing with multi-core CPU chips at a cost of slightly 1012 increased overhead in some places. If unsure say N here. 1013 1014config SCHED_MC_PRIO 1015 bool "CPU core priorities scheduler support" 1016 depends on SCHED_MC && CPU_SUP_INTEL 1017 select X86_INTEL_PSTATE 1018 select CPU_FREQ 1019 default y 1020 ---help--- 1021 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1022 core ordering determined at manufacturing time, which allows 1023 certain cores to reach higher turbo frequencies (when running 1024 single threaded workloads) than others. 1025 1026 Enabling this kernel feature teaches the scheduler about 1027 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1028 scheduler's CPU selection logic accordingly, so that higher 1029 overall system performance can be achieved. 1030 1031 This feature will have no effect on CPUs without this feature. 1032 1033 If unsure say Y here. 1034 1035config UP_LATE_INIT 1036 def_bool y 1037 depends on !SMP && X86_LOCAL_APIC 1038 1039config X86_UP_APIC 1040 bool "Local APIC support on uniprocessors" if !PCI_MSI 1041 default PCI_MSI 1042 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1043 ---help--- 1044 A local APIC (Advanced Programmable Interrupt Controller) is an 1045 integrated interrupt controller in the CPU. If you have a single-CPU 1046 system which has a processor with a local APIC, you can say Y here to 1047 enable and use it. If you say Y here even though your machine doesn't 1048 have a local APIC, then the kernel will still run with no slowdown at 1049 all. The local APIC supports CPU-generated self-interrupts (timer, 1050 performance counters), and the NMI watchdog which detects hard 1051 lockups. 1052 1053config X86_UP_IOAPIC 1054 bool "IO-APIC support on uniprocessors" 1055 depends on X86_UP_APIC 1056 ---help--- 1057 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1058 SMP-capable replacement for PC-style interrupt controllers. Most 1059 SMP systems and many recent uniprocessor systems have one. 1060 1061 If you have a single-CPU system with an IO-APIC, you can say Y here 1062 to use it. If you say Y here even though your machine doesn't have 1063 an IO-APIC, then the kernel will still run with no slowdown at all. 1064 1065config X86_LOCAL_APIC 1066 def_bool y 1067 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1068 select IRQ_DOMAIN_HIERARCHY 1069 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1070 1071config X86_IO_APIC 1072 def_bool y 1073 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1074 1075config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1076 bool "Reroute for broken boot IRQs" 1077 depends on X86_IO_APIC 1078 ---help--- 1079 This option enables a workaround that fixes a source of 1080 spurious interrupts. This is recommended when threaded 1081 interrupt handling is used on systems where the generation of 1082 superfluous "boot interrupts" cannot be disabled. 1083 1084 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1085 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1086 kernel does during interrupt handling). On chipsets where this 1087 boot IRQ generation cannot be disabled, this workaround keeps 1088 the original IRQ line masked so that only the equivalent "boot 1089 IRQ" is delivered to the CPUs. The workaround also tells the 1090 kernel to set up the IRQ handler on the boot IRQ line. In this 1091 way only one interrupt is delivered to the kernel. Otherwise 1092 the spurious second interrupt may cause the kernel to bring 1093 down (vital) interrupt lines. 1094 1095 Only affects "broken" chipsets. Interrupt sharing may be 1096 increased on these systems. 1097 1098config X86_MCE 1099 bool "Machine Check / overheating reporting" 1100 select GENERIC_ALLOCATOR 1101 default y 1102 ---help--- 1103 Machine Check support allows the processor to notify the 1104 kernel if it detects a problem (e.g. overheating, data corruption). 1105 The action the kernel takes depends on the severity of the problem, 1106 ranging from warning messages to halting the machine. 1107 1108config X86_MCELOG_LEGACY 1109 bool "Support for deprecated /dev/mcelog character device" 1110 depends on X86_MCE 1111 ---help--- 1112 Enable support for /dev/mcelog which is needed by the old mcelog 1113 userspace logging daemon. Consider switching to the new generation 1114 rasdaemon solution. 1115 1116config X86_MCE_INTEL 1117 def_bool y 1118 prompt "Intel MCE features" 1119 depends on X86_MCE && X86_LOCAL_APIC 1120 ---help--- 1121 Additional support for intel specific MCE features such as 1122 the thermal monitor. 1123 1124config X86_MCE_AMD 1125 def_bool y 1126 prompt "AMD MCE features" 1127 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1128 ---help--- 1129 Additional support for AMD specific MCE features such as 1130 the DRAM Error Threshold. 1131 1132config X86_ANCIENT_MCE 1133 bool "Support for old Pentium 5 / WinChip machine checks" 1134 depends on X86_32 && X86_MCE 1135 ---help--- 1136 Include support for machine check handling on old Pentium 5 or WinChip 1137 systems. These typically need to be enabled explicitly on the command 1138 line. 1139 1140config X86_MCE_THRESHOLD 1141 depends on X86_MCE_AMD || X86_MCE_INTEL 1142 def_bool y 1143 1144config X86_MCE_INJECT 1145 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1146 tristate "Machine check injector support" 1147 ---help--- 1148 Provide support for injecting machine checks for testing purposes. 1149 If you don't know what a machine check is and you don't do kernel 1150 QA it is safe to say n. 1151 1152config X86_THERMAL_VECTOR 1153 def_bool y 1154 depends on X86_MCE_INTEL 1155 1156source "arch/x86/events/Kconfig" 1157 1158config X86_LEGACY_VM86 1159 bool "Legacy VM86 support" 1160 depends on X86_32 1161 ---help--- 1162 This option allows user programs to put the CPU into V8086 1163 mode, which is an 80286-era approximation of 16-bit real mode. 1164 1165 Some very old versions of X and/or vbetool require this option 1166 for user mode setting. Similarly, DOSEMU will use it if 1167 available to accelerate real mode DOS programs. However, any 1168 recent version of DOSEMU, X, or vbetool should be fully 1169 functional even without kernel VM86 support, as they will all 1170 fall back to software emulation. Nevertheless, if you are using 1171 a 16-bit DOS program where 16-bit performance matters, vm86 1172 mode might be faster than emulation and you might want to 1173 enable this option. 1174 1175 Note that any app that works on a 64-bit kernel is unlikely to 1176 need this option, as 64-bit kernels don't, and can't, support 1177 V8086 mode. This option is also unrelated to 16-bit protected 1178 mode and is not needed to run most 16-bit programs under Wine. 1179 1180 Enabling this option increases the complexity of the kernel 1181 and slows down exception handling a tiny bit. 1182 1183 If unsure, say N here. 1184 1185config VM86 1186 bool 1187 default X86_LEGACY_VM86 1188 1189config X86_16BIT 1190 bool "Enable support for 16-bit segments" if EXPERT 1191 default y 1192 depends on MODIFY_LDT_SYSCALL 1193 ---help--- 1194 This option is required by programs like Wine to run 16-bit 1195 protected mode legacy code on x86 processors. Disabling 1196 this option saves about 300 bytes on i386, or around 6K text 1197 plus 16K runtime memory on x86-64, 1198 1199config X86_ESPFIX32 1200 def_bool y 1201 depends on X86_16BIT && X86_32 1202 1203config X86_ESPFIX64 1204 def_bool y 1205 depends on X86_16BIT && X86_64 1206 1207config X86_VSYSCALL_EMULATION 1208 bool "Enable vsyscall emulation" if EXPERT 1209 default y 1210 depends on X86_64 1211 ---help--- 1212 This enables emulation of the legacy vsyscall page. Disabling 1213 it is roughly equivalent to booting with vsyscall=none, except 1214 that it will also disable the helpful warning if a program 1215 tries to use a vsyscall. With this option set to N, offending 1216 programs will just segfault, citing addresses of the form 1217 0xffffffffff600?00. 1218 1219 This option is required by many programs built before 2013, and 1220 care should be used even with newer programs if set to N. 1221 1222 Disabling this option saves about 7K of kernel size and 1223 possibly 4K of additional runtime pagetable memory. 1224 1225config TOSHIBA 1226 tristate "Toshiba Laptop support" 1227 depends on X86_32 1228 ---help--- 1229 This adds a driver to safely access the System Management Mode of 1230 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1231 not work on models with a Phoenix BIOS. The System Management Mode 1232 is used to set the BIOS and power saving options on Toshiba portables. 1233 1234 For information on utilities to make use of this driver see the 1235 Toshiba Linux utilities web site at: 1236 <http://www.buzzard.org.uk/toshiba/>. 1237 1238 Say Y if you intend to run this kernel on a Toshiba portable. 1239 Say N otherwise. 1240 1241config I8K 1242 tristate "Dell i8k legacy laptop support" 1243 select HWMON 1244 select SENSORS_DELL_SMM 1245 ---help--- 1246 This option enables legacy /proc/i8k userspace interface in hwmon 1247 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1248 temperature and allows controlling fan speeds of Dell laptops via 1249 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1250 it reports also power and hotkey status. For fan speed control is 1251 needed userspace package i8kutils. 1252 1253 Say Y if you intend to run this kernel on old Dell laptops or want to 1254 use userspace package i8kutils. 1255 Say N otherwise. 1256 1257config X86_REBOOTFIXUPS 1258 bool "Enable X86 board specific fixups for reboot" 1259 depends on X86_32 1260 ---help--- 1261 This enables chipset and/or board specific fixups to be done 1262 in order to get reboot to work correctly. This is only needed on 1263 some combinations of hardware and BIOS. The symptom, for which 1264 this config is intended, is when reboot ends with a stalled/hung 1265 system. 1266 1267 Currently, the only fixup is for the Geode machines using 1268 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1269 1270 Say Y if you want to enable the fixup. Currently, it's safe to 1271 enable this option even if you don't need it. 1272 Say N otherwise. 1273 1274config MICROCODE 1275 bool "CPU microcode loading support" 1276 default y 1277 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1278 select FW_LOADER 1279 ---help--- 1280 If you say Y here, you will be able to update the microcode on 1281 Intel and AMD processors. The Intel support is for the IA32 family, 1282 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1283 AMD support is for families 0x10 and later. You will obviously need 1284 the actual microcode binary data itself which is not shipped with 1285 the Linux kernel. 1286 1287 The preferred method to load microcode from a detached initrd is described 1288 in Documentation/x86/microcode.txt. For that you need to enable 1289 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1290 initrd for microcode blobs. 1291 1292 In addition, you can build the microcode into the kernel. For that you 1293 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1294 config option. 1295 1296config MICROCODE_INTEL 1297 bool "Intel microcode loading support" 1298 depends on MICROCODE 1299 default MICROCODE 1300 select FW_LOADER 1301 ---help--- 1302 This options enables microcode patch loading support for Intel 1303 processors. 1304 1305 For the current Intel microcode data package go to 1306 <https://downloadcenter.intel.com> and search for 1307 'Linux Processor Microcode Data File'. 1308 1309config MICROCODE_AMD 1310 bool "AMD microcode loading support" 1311 depends on MICROCODE 1312 select FW_LOADER 1313 ---help--- 1314 If you select this option, microcode patch loading support for AMD 1315 processors will be enabled. 1316 1317config MICROCODE_OLD_INTERFACE 1318 def_bool y 1319 depends on MICROCODE 1320 1321config X86_MSR 1322 tristate "/dev/cpu/*/msr - Model-specific register support" 1323 ---help--- 1324 This device gives privileged processes access to the x86 1325 Model-Specific Registers (MSRs). It is a character device with 1326 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1327 MSR accesses are directed to a specific CPU on multi-processor 1328 systems. 1329 1330config X86_CPUID 1331 tristate "/dev/cpu/*/cpuid - CPU information support" 1332 ---help--- 1333 This device gives processes access to the x86 CPUID instruction to 1334 be executed on a specific processor. It is a character device 1335 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1336 /dev/cpu/31/cpuid. 1337 1338choice 1339 prompt "High Memory Support" 1340 default HIGHMEM4G 1341 depends on X86_32 1342 1343config NOHIGHMEM 1344 bool "off" 1345 ---help--- 1346 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1347 However, the address space of 32-bit x86 processors is only 4 1348 Gigabytes large. That means that, if you have a large amount of 1349 physical memory, not all of it can be "permanently mapped" by the 1350 kernel. The physical memory that's not permanently mapped is called 1351 "high memory". 1352 1353 If you are compiling a kernel which will never run on a machine with 1354 more than 1 Gigabyte total physical RAM, answer "off" here (default 1355 choice and suitable for most users). This will result in a "3GB/1GB" 1356 split: 3GB are mapped so that each process sees a 3GB virtual memory 1357 space and the remaining part of the 4GB virtual memory space is used 1358 by the kernel to permanently map as much physical memory as 1359 possible. 1360 1361 If the machine has between 1 and 4 Gigabytes physical RAM, then 1362 answer "4GB" here. 1363 1364 If more than 4 Gigabytes is used then answer "64GB" here. This 1365 selection turns Intel PAE (Physical Address Extension) mode on. 1366 PAE implements 3-level paging on IA32 processors. PAE is fully 1367 supported by Linux, PAE mode is implemented on all recent Intel 1368 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1369 then the kernel will not boot on CPUs that don't support PAE! 1370 1371 The actual amount of total physical memory will either be 1372 auto detected or can be forced by using a kernel command line option 1373 such as "mem=256M". (Try "man bootparam" or see the documentation of 1374 your boot loader (lilo or loadlin) about how to pass options to the 1375 kernel at boot time.) 1376 1377 If unsure, say "off". 1378 1379config HIGHMEM4G 1380 bool "4GB" 1381 ---help--- 1382 Select this if you have a 32-bit processor and between 1 and 4 1383 gigabytes of physical RAM. 1384 1385config HIGHMEM64G 1386 bool "64GB" 1387 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1388 select X86_PAE 1389 ---help--- 1390 Select this if you have a 32-bit processor and more than 4 1391 gigabytes of physical RAM. 1392 1393endchoice 1394 1395choice 1396 prompt "Memory split" if EXPERT 1397 default VMSPLIT_3G 1398 depends on X86_32 1399 ---help--- 1400 Select the desired split between kernel and user memory. 1401 1402 If the address range available to the kernel is less than the 1403 physical memory installed, the remaining memory will be available 1404 as "high memory". Accessing high memory is a little more costly 1405 than low memory, as it needs to be mapped into the kernel first. 1406 Note that increasing the kernel address space limits the range 1407 available to user programs, making the address space there 1408 tighter. Selecting anything other than the default 3G/1G split 1409 will also likely make your kernel incompatible with binary-only 1410 kernel modules. 1411 1412 If you are not absolutely sure what you are doing, leave this 1413 option alone! 1414 1415 config VMSPLIT_3G 1416 bool "3G/1G user/kernel split" 1417 config VMSPLIT_3G_OPT 1418 depends on !X86_PAE 1419 bool "3G/1G user/kernel split (for full 1G low memory)" 1420 config VMSPLIT_2G 1421 bool "2G/2G user/kernel split" 1422 config VMSPLIT_2G_OPT 1423 depends on !X86_PAE 1424 bool "2G/2G user/kernel split (for full 2G low memory)" 1425 config VMSPLIT_1G 1426 bool "1G/3G user/kernel split" 1427endchoice 1428 1429config PAGE_OFFSET 1430 hex 1431 default 0xB0000000 if VMSPLIT_3G_OPT 1432 default 0x80000000 if VMSPLIT_2G 1433 default 0x78000000 if VMSPLIT_2G_OPT 1434 default 0x40000000 if VMSPLIT_1G 1435 default 0xC0000000 1436 depends on X86_32 1437 1438config HIGHMEM 1439 def_bool y 1440 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1441 1442config X86_PAE 1443 bool "PAE (Physical Address Extension) Support" 1444 depends on X86_32 && !HIGHMEM4G 1445 select PHYS_ADDR_T_64BIT 1446 select SWIOTLB 1447 ---help--- 1448 PAE is required for NX support, and furthermore enables 1449 larger swapspace support for non-overcommit purposes. It 1450 has the cost of more pagetable lookup overhead, and also 1451 consumes more pagetable space per process. 1452 1453config X86_5LEVEL 1454 bool "Enable 5-level page tables support" 1455 select DYNAMIC_MEMORY_LAYOUT 1456 select SPARSEMEM_VMEMMAP 1457 depends on X86_64 1458 ---help--- 1459 5-level paging enables access to larger address space: 1460 upto 128 PiB of virtual address space and 4 PiB of 1461 physical address space. 1462 1463 It will be supported by future Intel CPUs. 1464 1465 A kernel with the option enabled can be booted on machines that 1466 support 4- or 5-level paging. 1467 1468 See Documentation/x86/x86_64/5level-paging.txt for more 1469 information. 1470 1471 Say N if unsure. 1472 1473config X86_DIRECT_GBPAGES 1474 def_bool y 1475 depends on X86_64 && !DEBUG_PAGEALLOC 1476 ---help--- 1477 Certain kernel features effectively disable kernel 1478 linear 1 GB mappings (even if the CPU otherwise 1479 supports them), so don't confuse the user by printing 1480 that we have them enabled. 1481 1482config X86_CPA_STATISTICS 1483 bool "Enable statistic for Change Page Attribute" 1484 depends on DEBUG_FS 1485 ---help--- 1486 Expose statistics about the Change Page Attribute mechanims, which 1487 helps to determine the effectivness of preserving large and huge 1488 page mappings when mapping protections are changed. 1489 1490config ARCH_HAS_MEM_ENCRYPT 1491 def_bool y 1492 1493config AMD_MEM_ENCRYPT 1494 bool "AMD Secure Memory Encryption (SME) support" 1495 depends on X86_64 && CPU_SUP_AMD 1496 select DYNAMIC_PHYSICAL_MASK 1497 ---help--- 1498 Say yes to enable support for the encryption of system memory. 1499 This requires an AMD processor that supports Secure Memory 1500 Encryption (SME). 1501 1502config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1503 bool "Activate AMD Secure Memory Encryption (SME) by default" 1504 default y 1505 depends on AMD_MEM_ENCRYPT 1506 ---help--- 1507 Say yes to have system memory encrypted by default if running on 1508 an AMD processor that supports Secure Memory Encryption (SME). 1509 1510 If set to Y, then the encryption of system memory can be 1511 deactivated with the mem_encrypt=off command line option. 1512 1513 If set to N, then the encryption of system memory can be 1514 activated with the mem_encrypt=on command line option. 1515 1516config ARCH_USE_MEMREMAP_PROT 1517 def_bool y 1518 depends on AMD_MEM_ENCRYPT 1519 1520# Common NUMA Features 1521config NUMA 1522 bool "Numa Memory Allocation and Scheduler Support" 1523 depends on SMP 1524 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1525 default y if X86_BIGSMP 1526 ---help--- 1527 Enable NUMA (Non Uniform Memory Access) support. 1528 1529 The kernel will try to allocate memory used by a CPU on the 1530 local memory controller of the CPU and add some more 1531 NUMA awareness to the kernel. 1532 1533 For 64-bit this is recommended if the system is Intel Core i7 1534 (or later), AMD Opteron, or EM64T NUMA. 1535 1536 For 32-bit this is only needed if you boot a 32-bit 1537 kernel on a 64-bit NUMA platform. 1538 1539 Otherwise, you should say N. 1540 1541config AMD_NUMA 1542 def_bool y 1543 prompt "Old style AMD Opteron NUMA detection" 1544 depends on X86_64 && NUMA && PCI 1545 ---help--- 1546 Enable AMD NUMA node topology detection. You should say Y here if 1547 you have a multi processor AMD system. This uses an old method to 1548 read the NUMA configuration directly from the builtin Northbridge 1549 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1550 which also takes priority if both are compiled in. 1551 1552config X86_64_ACPI_NUMA 1553 def_bool y 1554 prompt "ACPI NUMA detection" 1555 depends on X86_64 && NUMA && ACPI && PCI 1556 select ACPI_NUMA 1557 ---help--- 1558 Enable ACPI SRAT based node topology detection. 1559 1560# Some NUMA nodes have memory ranges that span 1561# other nodes. Even though a pfn is valid and 1562# between a node's start and end pfns, it may not 1563# reside on that node. See memmap_init_zone() 1564# for details. 1565config NODES_SPAN_OTHER_NODES 1566 def_bool y 1567 depends on X86_64_ACPI_NUMA 1568 1569config NUMA_EMU 1570 bool "NUMA emulation" 1571 depends on NUMA 1572 ---help--- 1573 Enable NUMA emulation. A flat machine will be split 1574 into virtual nodes when booted with "numa=fake=N", where N is the 1575 number of nodes. This is only useful for debugging. 1576 1577config NODES_SHIFT 1578 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1579 range 1 10 1580 default "10" if MAXSMP 1581 default "6" if X86_64 1582 default "3" 1583 depends on NEED_MULTIPLE_NODES 1584 ---help--- 1585 Specify the maximum number of NUMA Nodes available on the target 1586 system. Increases memory reserved to accommodate various tables. 1587 1588config ARCH_HAVE_MEMORY_PRESENT 1589 def_bool y 1590 depends on X86_32 && DISCONTIGMEM 1591 1592config ARCH_FLATMEM_ENABLE 1593 def_bool y 1594 depends on X86_32 && !NUMA 1595 1596config ARCH_DISCONTIGMEM_ENABLE 1597 def_bool y 1598 depends on NUMA && X86_32 1599 1600config ARCH_DISCONTIGMEM_DEFAULT 1601 def_bool y 1602 depends on NUMA && X86_32 1603 1604config ARCH_SPARSEMEM_ENABLE 1605 def_bool y 1606 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1607 select SPARSEMEM_STATIC if X86_32 1608 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1609 1610config ARCH_SPARSEMEM_DEFAULT 1611 def_bool y 1612 depends on X86_64 1613 1614config ARCH_SELECT_MEMORY_MODEL 1615 def_bool y 1616 depends on ARCH_SPARSEMEM_ENABLE 1617 1618config ARCH_MEMORY_PROBE 1619 bool "Enable sysfs memory/probe interface" 1620 depends on X86_64 && MEMORY_HOTPLUG 1621 help 1622 This option enables a sysfs memory/probe interface for testing. 1623 See Documentation/memory-hotplug.txt for more information. 1624 If you are unsure how to answer this question, answer N. 1625 1626config ARCH_PROC_KCORE_TEXT 1627 def_bool y 1628 depends on X86_64 && PROC_KCORE 1629 1630config ILLEGAL_POINTER_VALUE 1631 hex 1632 default 0 if X86_32 1633 default 0xdead000000000000 if X86_64 1634 1635config X86_PMEM_LEGACY_DEVICE 1636 bool 1637 1638config X86_PMEM_LEGACY 1639 tristate "Support non-standard NVDIMMs and ADR protected memory" 1640 depends on PHYS_ADDR_T_64BIT 1641 depends on BLK_DEV 1642 select X86_PMEM_LEGACY_DEVICE 1643 select LIBNVDIMM 1644 help 1645 Treat memory marked using the non-standard e820 type of 12 as used 1646 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1647 The kernel will offer these regions to the 'pmem' driver so 1648 they can be used for persistent storage. 1649 1650 Say Y if unsure. 1651 1652config HIGHPTE 1653 bool "Allocate 3rd-level pagetables from highmem" 1654 depends on HIGHMEM 1655 ---help--- 1656 The VM uses one page table entry for each page of physical memory. 1657 For systems with a lot of RAM, this can be wasteful of precious 1658 low memory. Setting this option will put user-space page table 1659 entries in high memory. 1660 1661config X86_CHECK_BIOS_CORRUPTION 1662 bool "Check for low memory corruption" 1663 ---help--- 1664 Periodically check for memory corruption in low memory, which 1665 is suspected to be caused by BIOS. Even when enabled in the 1666 configuration, it is disabled at runtime. Enable it by 1667 setting "memory_corruption_check=1" on the kernel command 1668 line. By default it scans the low 64k of memory every 60 1669 seconds; see the memory_corruption_check_size and 1670 memory_corruption_check_period parameters in 1671 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1672 1673 When enabled with the default parameters, this option has 1674 almost no overhead, as it reserves a relatively small amount 1675 of memory and scans it infrequently. It both detects corruption 1676 and prevents it from affecting the running system. 1677 1678 It is, however, intended as a diagnostic tool; if repeatable 1679 BIOS-originated corruption always affects the same memory, 1680 you can use memmap= to prevent the kernel from using that 1681 memory. 1682 1683config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1684 bool "Set the default setting of memory_corruption_check" 1685 depends on X86_CHECK_BIOS_CORRUPTION 1686 default y 1687 ---help--- 1688 Set whether the default state of memory_corruption_check is 1689 on or off. 1690 1691config X86_RESERVE_LOW 1692 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1693 default 64 1694 range 4 640 1695 ---help--- 1696 Specify the amount of low memory to reserve for the BIOS. 1697 1698 The first page contains BIOS data structures that the kernel 1699 must not use, so that page must always be reserved. 1700 1701 By default we reserve the first 64K of physical RAM, as a 1702 number of BIOSes are known to corrupt that memory range 1703 during events such as suspend/resume or monitor cable 1704 insertion, so it must not be used by the kernel. 1705 1706 You can set this to 4 if you are absolutely sure that you 1707 trust the BIOS to get all its memory reservations and usages 1708 right. If you know your BIOS have problems beyond the 1709 default 64K area, you can set this to 640 to avoid using the 1710 entire low memory range. 1711 1712 If you have doubts about the BIOS (e.g. suspend/resume does 1713 not work or there's kernel crashes after certain hardware 1714 hotplug events) then you might want to enable 1715 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1716 typical corruption patterns. 1717 1718 Leave this to the default value of 64 if you are unsure. 1719 1720config MATH_EMULATION 1721 bool 1722 depends on MODIFY_LDT_SYSCALL 1723 prompt "Math emulation" if X86_32 1724 ---help--- 1725 Linux can emulate a math coprocessor (used for floating point 1726 operations) if you don't have one. 486DX and Pentium processors have 1727 a math coprocessor built in, 486SX and 386 do not, unless you added 1728 a 487DX or 387, respectively. (The messages during boot time can 1729 give you some hints here ["man dmesg"].) Everyone needs either a 1730 coprocessor or this emulation. 1731 1732 If you don't have a math coprocessor, you need to say Y here; if you 1733 say Y here even though you have a coprocessor, the coprocessor will 1734 be used nevertheless. (This behavior can be changed with the kernel 1735 command line option "no387", which comes handy if your coprocessor 1736 is broken. Try "man bootparam" or see the documentation of your boot 1737 loader (lilo or loadlin) about how to pass options to the kernel at 1738 boot time.) This means that it is a good idea to say Y here if you 1739 intend to use this kernel on different machines. 1740 1741 More information about the internals of the Linux math coprocessor 1742 emulation can be found in <file:arch/x86/math-emu/README>. 1743 1744 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1745 kernel, it won't hurt. 1746 1747config MTRR 1748 def_bool y 1749 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1750 ---help--- 1751 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1752 the Memory Type Range Registers (MTRRs) may be used to control 1753 processor access to memory ranges. This is most useful if you have 1754 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1755 allows bus write transfers to be combined into a larger transfer 1756 before bursting over the PCI/AGP bus. This can increase performance 1757 of image write operations 2.5 times or more. Saying Y here creates a 1758 /proc/mtrr file which may be used to manipulate your processor's 1759 MTRRs. Typically the X server should use this. 1760 1761 This code has a reasonably generic interface so that similar 1762 control registers on other processors can be easily supported 1763 as well: 1764 1765 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1766 Registers (ARRs) which provide a similar functionality to MTRRs. For 1767 these, the ARRs are used to emulate the MTRRs. 1768 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1769 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1770 write-combining. All of these processors are supported by this code 1771 and it makes sense to say Y here if you have one of them. 1772 1773 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1774 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1775 can lead to all sorts of problems, so it's good to say Y here. 1776 1777 You can safely say Y even if your machine doesn't have MTRRs, you'll 1778 just add about 9 KB to your kernel. 1779 1780 See <file:Documentation/x86/mtrr.txt> for more information. 1781 1782config MTRR_SANITIZER 1783 def_bool y 1784 prompt "MTRR cleanup support" 1785 depends on MTRR 1786 ---help--- 1787 Convert MTRR layout from continuous to discrete, so X drivers can 1788 add writeback entries. 1789 1790 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1791 The largest mtrr entry size for a continuous block can be set with 1792 mtrr_chunk_size. 1793 1794 If unsure, say Y. 1795 1796config MTRR_SANITIZER_ENABLE_DEFAULT 1797 int "MTRR cleanup enable value (0-1)" 1798 range 0 1 1799 default "0" 1800 depends on MTRR_SANITIZER 1801 ---help--- 1802 Enable mtrr cleanup default value 1803 1804config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1805 int "MTRR cleanup spare reg num (0-7)" 1806 range 0 7 1807 default "1" 1808 depends on MTRR_SANITIZER 1809 ---help--- 1810 mtrr cleanup spare entries default, it can be changed via 1811 mtrr_spare_reg_nr=N on the kernel command line. 1812 1813config X86_PAT 1814 def_bool y 1815 prompt "x86 PAT support" if EXPERT 1816 depends on MTRR 1817 ---help--- 1818 Use PAT attributes to setup page level cache control. 1819 1820 PATs are the modern equivalents of MTRRs and are much more 1821 flexible than MTRRs. 1822 1823 Say N here if you see bootup problems (boot crash, boot hang, 1824 spontaneous reboots) or a non-working video driver. 1825 1826 If unsure, say Y. 1827 1828config ARCH_USES_PG_UNCACHED 1829 def_bool y 1830 depends on X86_PAT 1831 1832config ARCH_RANDOM 1833 def_bool y 1834 prompt "x86 architectural random number generator" if EXPERT 1835 ---help--- 1836 Enable the x86 architectural RDRAND instruction 1837 (Intel Bull Mountain technology) to generate random numbers. 1838 If supported, this is a high bandwidth, cryptographically 1839 secure hardware random number generator. 1840 1841config X86_SMAP 1842 def_bool y 1843 prompt "Supervisor Mode Access Prevention" if EXPERT 1844 ---help--- 1845 Supervisor Mode Access Prevention (SMAP) is a security 1846 feature in newer Intel processors. There is a small 1847 performance cost if this enabled and turned on; there is 1848 also a small increase in the kernel size if this is enabled. 1849 1850 If unsure, say Y. 1851 1852config X86_INTEL_UMIP 1853 def_bool y 1854 depends on CPU_SUP_INTEL 1855 prompt "Intel User Mode Instruction Prevention" if EXPERT 1856 ---help--- 1857 The User Mode Instruction Prevention (UMIP) is a security 1858 feature in newer Intel processors. If enabled, a general 1859 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1860 or STR instructions are executed in user mode. These instructions 1861 unnecessarily expose information about the hardware state. 1862 1863 The vast majority of applications do not use these instructions. 1864 For the very few that do, software emulation is provided in 1865 specific cases in protected and virtual-8086 modes. Emulated 1866 results are dummy. 1867 1868config X86_INTEL_MPX 1869 prompt "Intel MPX (Memory Protection Extensions)" 1870 def_bool n 1871 # Note: only available in 64-bit mode due to VMA flags shortage 1872 depends on CPU_SUP_INTEL && X86_64 1873 select ARCH_USES_HIGH_VMA_FLAGS 1874 ---help--- 1875 MPX provides hardware features that can be used in 1876 conjunction with compiler-instrumented code to check 1877 memory references. It is designed to detect buffer 1878 overflow or underflow bugs. 1879 1880 This option enables running applications which are 1881 instrumented or otherwise use MPX. It does not use MPX 1882 itself inside the kernel or to protect the kernel 1883 against bad memory references. 1884 1885 Enabling this option will make the kernel larger: 1886 ~8k of kernel text and 36 bytes of data on a 64-bit 1887 defconfig. It adds a long to the 'mm_struct' which 1888 will increase the kernel memory overhead of each 1889 process and adds some branches to paths used during 1890 exec() and munmap(). 1891 1892 For details, see Documentation/x86/intel_mpx.txt 1893 1894 If unsure, say N. 1895 1896config X86_INTEL_MEMORY_PROTECTION_KEYS 1897 prompt "Intel Memory Protection Keys" 1898 def_bool y 1899 # Note: only available in 64-bit mode 1900 depends on CPU_SUP_INTEL && X86_64 1901 select ARCH_USES_HIGH_VMA_FLAGS 1902 select ARCH_HAS_PKEYS 1903 ---help--- 1904 Memory Protection Keys provides a mechanism for enforcing 1905 page-based protections, but without requiring modification of the 1906 page tables when an application changes protection domains. 1907 1908 For details, see Documentation/x86/protection-keys.txt 1909 1910 If unsure, say y. 1911 1912config EFI 1913 bool "EFI runtime service support" 1914 depends on ACPI 1915 select UCS2_STRING 1916 select EFI_RUNTIME_WRAPPERS 1917 ---help--- 1918 This enables the kernel to use EFI runtime services that are 1919 available (such as the EFI variable services). 1920 1921 This option is only useful on systems that have EFI firmware. 1922 In addition, you should use the latest ELILO loader available 1923 at <http://elilo.sourceforge.net> in order to take advantage 1924 of EFI runtime services. However, even with this option, the 1925 resultant kernel should continue to boot on existing non-EFI 1926 platforms. 1927 1928config EFI_STUB 1929 bool "EFI stub support" 1930 depends on EFI && !X86_USE_3DNOW 1931 select RELOCATABLE 1932 ---help--- 1933 This kernel feature allows a bzImage to be loaded directly 1934 by EFI firmware without the use of a bootloader. 1935 1936 See Documentation/efi-stub.txt for more information. 1937 1938config EFI_MIXED 1939 bool "EFI mixed-mode support" 1940 depends on EFI_STUB && X86_64 1941 ---help--- 1942 Enabling this feature allows a 64-bit kernel to be booted 1943 on a 32-bit firmware, provided that your CPU supports 64-bit 1944 mode. 1945 1946 Note that it is not possible to boot a mixed-mode enabled 1947 kernel via the EFI boot stub - a bootloader that supports 1948 the EFI handover protocol must be used. 1949 1950 If unsure, say N. 1951 1952config SECCOMP 1953 def_bool y 1954 prompt "Enable seccomp to safely compute untrusted bytecode" 1955 ---help--- 1956 This kernel feature is useful for number crunching applications 1957 that may need to compute untrusted bytecode during their 1958 execution. By using pipes or other transports made available to 1959 the process as file descriptors supporting the read/write 1960 syscalls, it's possible to isolate those applications in 1961 their own address space using seccomp. Once seccomp is 1962 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1963 and the task is only allowed to execute a few safe syscalls 1964 defined by each seccomp mode. 1965 1966 If unsure, say Y. Only embedded should say N here. 1967 1968source kernel/Kconfig.hz 1969 1970config KEXEC 1971 bool "kexec system call" 1972 select KEXEC_CORE 1973 ---help--- 1974 kexec is a system call that implements the ability to shutdown your 1975 current kernel, and to start another kernel. It is like a reboot 1976 but it is independent of the system firmware. And like a reboot 1977 you can start any kernel with it, not just Linux. 1978 1979 The name comes from the similarity to the exec system call. 1980 1981 It is an ongoing process to be certain the hardware in a machine 1982 is properly shutdown, so do not be surprised if this code does not 1983 initially work for you. As of this writing the exact hardware 1984 interface is strongly in flux, so no good recommendation can be 1985 made. 1986 1987config KEXEC_FILE 1988 bool "kexec file based system call" 1989 select KEXEC_CORE 1990 select BUILD_BIN2C 1991 depends on X86_64 1992 depends on CRYPTO=y 1993 depends on CRYPTO_SHA256=y 1994 ---help--- 1995 This is new version of kexec system call. This system call is 1996 file based and takes file descriptors as system call argument 1997 for kernel and initramfs as opposed to list of segments as 1998 accepted by previous system call. 1999 2000config ARCH_HAS_KEXEC_PURGATORY 2001 def_bool KEXEC_FILE 2002 2003config KEXEC_VERIFY_SIG 2004 bool "Verify kernel signature during kexec_file_load() syscall" 2005 depends on KEXEC_FILE 2006 ---help--- 2007 This option makes kernel signature verification mandatory for 2008 the kexec_file_load() syscall. 2009 2010 In addition to that option, you need to enable signature 2011 verification for the corresponding kernel image type being 2012 loaded in order for this to work. 2013 2014config KEXEC_BZIMAGE_VERIFY_SIG 2015 bool "Enable bzImage signature verification support" 2016 depends on KEXEC_VERIFY_SIG 2017 depends on SIGNED_PE_FILE_VERIFICATION 2018 select SYSTEM_TRUSTED_KEYRING 2019 ---help--- 2020 Enable bzImage signature verification support. 2021 2022config CRASH_DUMP 2023 bool "kernel crash dumps" 2024 depends on X86_64 || (X86_32 && HIGHMEM) 2025 ---help--- 2026 Generate crash dump after being started by kexec. 2027 This should be normally only set in special crash dump kernels 2028 which are loaded in the main kernel with kexec-tools into 2029 a specially reserved region and then later executed after 2030 a crash by kdump/kexec. The crash dump kernel must be compiled 2031 to a memory address not used by the main kernel or BIOS using 2032 PHYSICAL_START, or it must be built as a relocatable image 2033 (CONFIG_RELOCATABLE=y). 2034 For more details see Documentation/kdump/kdump.txt 2035 2036config KEXEC_JUMP 2037 bool "kexec jump" 2038 depends on KEXEC && HIBERNATION 2039 ---help--- 2040 Jump between original kernel and kexeced kernel and invoke 2041 code in physical address mode via KEXEC 2042 2043config PHYSICAL_START 2044 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2045 default "0x1000000" 2046 ---help--- 2047 This gives the physical address where the kernel is loaded. 2048 2049 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2050 bzImage will decompress itself to above physical address and 2051 run from there. Otherwise, bzImage will run from the address where 2052 it has been loaded by the boot loader and will ignore above physical 2053 address. 2054 2055 In normal kdump cases one does not have to set/change this option 2056 as now bzImage can be compiled as a completely relocatable image 2057 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2058 address. This option is mainly useful for the folks who don't want 2059 to use a bzImage for capturing the crash dump and want to use a 2060 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2061 to be specifically compiled to run from a specific memory area 2062 (normally a reserved region) and this option comes handy. 2063 2064 So if you are using bzImage for capturing the crash dump, 2065 leave the value here unchanged to 0x1000000 and set 2066 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2067 for capturing the crash dump change this value to start of 2068 the reserved region. In other words, it can be set based on 2069 the "X" value as specified in the "crashkernel=YM@XM" 2070 command line boot parameter passed to the panic-ed 2071 kernel. Please take a look at Documentation/kdump/kdump.txt 2072 for more details about crash dumps. 2073 2074 Usage of bzImage for capturing the crash dump is recommended as 2075 one does not have to build two kernels. Same kernel can be used 2076 as production kernel and capture kernel. Above option should have 2077 gone away after relocatable bzImage support is introduced. But it 2078 is present because there are users out there who continue to use 2079 vmlinux for dump capture. This option should go away down the 2080 line. 2081 2082 Don't change this unless you know what you are doing. 2083 2084config RELOCATABLE 2085 bool "Build a relocatable kernel" 2086 default y 2087 ---help--- 2088 This builds a kernel image that retains relocation information 2089 so it can be loaded someplace besides the default 1MB. 2090 The relocations tend to make the kernel binary about 10% larger, 2091 but are discarded at runtime. 2092 2093 One use is for the kexec on panic case where the recovery kernel 2094 must live at a different physical address than the primary 2095 kernel. 2096 2097 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2098 it has been loaded at and the compile time physical address 2099 (CONFIG_PHYSICAL_START) is used as the minimum location. 2100 2101config RANDOMIZE_BASE 2102 bool "Randomize the address of the kernel image (KASLR)" 2103 depends on RELOCATABLE 2104 default y 2105 ---help--- 2106 In support of Kernel Address Space Layout Randomization (KASLR), 2107 this randomizes the physical address at which the kernel image 2108 is decompressed and the virtual address where the kernel 2109 image is mapped, as a security feature that deters exploit 2110 attempts relying on knowledge of the location of kernel 2111 code internals. 2112 2113 On 64-bit, the kernel physical and virtual addresses are 2114 randomized separately. The physical address will be anywhere 2115 between 16MB and the top of physical memory (up to 64TB). The 2116 virtual address will be randomized from 16MB up to 1GB (9 bits 2117 of entropy). Note that this also reduces the memory space 2118 available to kernel modules from 1.5GB to 1GB. 2119 2120 On 32-bit, the kernel physical and virtual addresses are 2121 randomized together. They will be randomized from 16MB up to 2122 512MB (8 bits of entropy). 2123 2124 Entropy is generated using the RDRAND instruction if it is 2125 supported. If RDTSC is supported, its value is mixed into 2126 the entropy pool as well. If neither RDRAND nor RDTSC are 2127 supported, then entropy is read from the i8254 timer. The 2128 usable entropy is limited by the kernel being built using 2129 2GB addressing, and that PHYSICAL_ALIGN must be at a 2130 minimum of 2MB. As a result, only 10 bits of entropy are 2131 theoretically possible, but the implementations are further 2132 limited due to memory layouts. 2133 2134 If unsure, say Y. 2135 2136# Relocation on x86 needs some additional build support 2137config X86_NEED_RELOCS 2138 def_bool y 2139 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2140 2141config PHYSICAL_ALIGN 2142 hex "Alignment value to which kernel should be aligned" 2143 default "0x200000" 2144 range 0x2000 0x1000000 if X86_32 2145 range 0x200000 0x1000000 if X86_64 2146 ---help--- 2147 This value puts the alignment restrictions on physical address 2148 where kernel is loaded and run from. Kernel is compiled for an 2149 address which meets above alignment restriction. 2150 2151 If bootloader loads the kernel at a non-aligned address and 2152 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2153 address aligned to above value and run from there. 2154 2155 If bootloader loads the kernel at a non-aligned address and 2156 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2157 load address and decompress itself to the address it has been 2158 compiled for and run from there. The address for which kernel is 2159 compiled already meets above alignment restrictions. Hence the 2160 end result is that kernel runs from a physical address meeting 2161 above alignment restrictions. 2162 2163 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2164 this value must be a multiple of 0x200000. 2165 2166 Don't change this unless you know what you are doing. 2167 2168config DYNAMIC_MEMORY_LAYOUT 2169 bool 2170 ---help--- 2171 This option makes base addresses of vmalloc and vmemmap as well as 2172 __PAGE_OFFSET movable during boot. 2173 2174config RANDOMIZE_MEMORY 2175 bool "Randomize the kernel memory sections" 2176 depends on X86_64 2177 depends on RANDOMIZE_BASE 2178 select DYNAMIC_MEMORY_LAYOUT 2179 default RANDOMIZE_BASE 2180 ---help--- 2181 Randomizes the base virtual address of kernel memory sections 2182 (physical memory mapping, vmalloc & vmemmap). This security feature 2183 makes exploits relying on predictable memory locations less reliable. 2184 2185 The order of allocations remains unchanged. Entropy is generated in 2186 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2187 configuration have in average 30,000 different possible virtual 2188 addresses for each memory section. 2189 2190 If unsure, say Y. 2191 2192config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2193 hex "Physical memory mapping padding" if EXPERT 2194 depends on RANDOMIZE_MEMORY 2195 default "0xa" if MEMORY_HOTPLUG 2196 default "0x0" 2197 range 0x1 0x40 if MEMORY_HOTPLUG 2198 range 0x0 0x40 2199 ---help--- 2200 Define the padding in terabytes added to the existing physical 2201 memory size during kernel memory randomization. It is useful 2202 for memory hotplug support but reduces the entropy available for 2203 address randomization. 2204 2205 If unsure, leave at the default value. 2206 2207config HOTPLUG_CPU 2208 bool "Support for hot-pluggable CPUs" 2209 depends on SMP 2210 ---help--- 2211 Say Y here to allow turning CPUs off and on. CPUs can be 2212 controlled through /sys/devices/system/cpu. 2213 ( Note: power management support will enable this option 2214 automatically on SMP systems. ) 2215 Say N if you want to disable CPU hotplug. 2216 2217config BOOTPARAM_HOTPLUG_CPU0 2218 bool "Set default setting of cpu0_hotpluggable" 2219 depends on HOTPLUG_CPU 2220 ---help--- 2221 Set whether default state of cpu0_hotpluggable is on or off. 2222 2223 Say Y here to enable CPU0 hotplug by default. If this switch 2224 is turned on, there is no need to give cpu0_hotplug kernel 2225 parameter and the CPU0 hotplug feature is enabled by default. 2226 2227 Please note: there are two known CPU0 dependencies if you want 2228 to enable the CPU0 hotplug feature either by this switch or by 2229 cpu0_hotplug kernel parameter. 2230 2231 First, resume from hibernate or suspend always starts from CPU0. 2232 So hibernate and suspend are prevented if CPU0 is offline. 2233 2234 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2235 offline if any interrupt can not migrate out of CPU0. There may 2236 be other CPU0 dependencies. 2237 2238 Please make sure the dependencies are under your control before 2239 you enable this feature. 2240 2241 Say N if you don't want to enable CPU0 hotplug feature by default. 2242 You still can enable the CPU0 hotplug feature at boot by kernel 2243 parameter cpu0_hotplug. 2244 2245config DEBUG_HOTPLUG_CPU0 2246 def_bool n 2247 prompt "Debug CPU0 hotplug" 2248 depends on HOTPLUG_CPU 2249 ---help--- 2250 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2251 soon as possible and boots up userspace with CPU0 offlined. User 2252 can online CPU0 back after boot time. 2253 2254 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2255 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2256 compilation or giving cpu0_hotplug kernel parameter at boot. 2257 2258 If unsure, say N. 2259 2260config COMPAT_VDSO 2261 def_bool n 2262 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2263 depends on COMPAT_32 2264 ---help--- 2265 Certain buggy versions of glibc will crash if they are 2266 presented with a 32-bit vDSO that is not mapped at the address 2267 indicated in its segment table. 2268 2269 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2270 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2271 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2272 the only released version with the bug, but OpenSUSE 9 2273 contains a buggy "glibc 2.3.2". 2274 2275 The symptom of the bug is that everything crashes on startup, saying: 2276 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2277 2278 Saying Y here changes the default value of the vdso32 boot 2279 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2280 This works around the glibc bug but hurts performance. 2281 2282 If unsure, say N: if you are compiling your own kernel, you 2283 are unlikely to be using a buggy version of glibc. 2284 2285choice 2286 prompt "vsyscall table for legacy applications" 2287 depends on X86_64 2288 default LEGACY_VSYSCALL_EMULATE 2289 help 2290 Legacy user code that does not know how to find the vDSO expects 2291 to be able to issue three syscalls by calling fixed addresses in 2292 kernel space. Since this location is not randomized with ASLR, 2293 it can be used to assist security vulnerability exploitation. 2294 2295 This setting can be changed at boot time via the kernel command 2296 line parameter vsyscall=[emulate|none]. 2297 2298 On a system with recent enough glibc (2.14 or newer) and no 2299 static binaries, you can say None without a performance penalty 2300 to improve security. 2301 2302 If unsure, select "Emulate". 2303 2304 config LEGACY_VSYSCALL_EMULATE 2305 bool "Emulate" 2306 help 2307 The kernel traps and emulates calls into the fixed 2308 vsyscall address mapping. This makes the mapping 2309 non-executable, but it still contains known contents, 2310 which could be used in certain rare security vulnerability 2311 exploits. This configuration is recommended when userspace 2312 still uses the vsyscall area. 2313 2314 config LEGACY_VSYSCALL_NONE 2315 bool "None" 2316 help 2317 There will be no vsyscall mapping at all. This will 2318 eliminate any risk of ASLR bypass due to the vsyscall 2319 fixed address mapping. Attempts to use the vsyscalls 2320 will be reported to dmesg, so that either old or 2321 malicious userspace programs can be identified. 2322 2323endchoice 2324 2325config CMDLINE_BOOL 2326 bool "Built-in kernel command line" 2327 ---help--- 2328 Allow for specifying boot arguments to the kernel at 2329 build time. On some systems (e.g. embedded ones), it is 2330 necessary or convenient to provide some or all of the 2331 kernel boot arguments with the kernel itself (that is, 2332 to not rely on the boot loader to provide them.) 2333 2334 To compile command line arguments into the kernel, 2335 set this option to 'Y', then fill in the 2336 boot arguments in CONFIG_CMDLINE. 2337 2338 Systems with fully functional boot loaders (i.e. non-embedded) 2339 should leave this option set to 'N'. 2340 2341config CMDLINE 2342 string "Built-in kernel command string" 2343 depends on CMDLINE_BOOL 2344 default "" 2345 ---help--- 2346 Enter arguments here that should be compiled into the kernel 2347 image and used at boot time. If the boot loader provides a 2348 command line at boot time, it is appended to this string to 2349 form the full kernel command line, when the system boots. 2350 2351 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2352 change this behavior. 2353 2354 In most cases, the command line (whether built-in or provided 2355 by the boot loader) should specify the device for the root 2356 file system. 2357 2358config CMDLINE_OVERRIDE 2359 bool "Built-in command line overrides boot loader arguments" 2360 depends on CMDLINE_BOOL 2361 ---help--- 2362 Set this option to 'Y' to have the kernel ignore the boot loader 2363 command line, and use ONLY the built-in command line. 2364 2365 This is used to work around broken boot loaders. This should 2366 be set to 'N' under normal conditions. 2367 2368config MODIFY_LDT_SYSCALL 2369 bool "Enable the LDT (local descriptor table)" if EXPERT 2370 default y 2371 ---help--- 2372 Linux can allow user programs to install a per-process x86 2373 Local Descriptor Table (LDT) using the modify_ldt(2) system 2374 call. This is required to run 16-bit or segmented code such as 2375 DOSEMU or some Wine programs. It is also used by some very old 2376 threading libraries. 2377 2378 Enabling this feature adds a small amount of overhead to 2379 context switches and increases the low-level kernel attack 2380 surface. Disabling it removes the modify_ldt(2) system call. 2381 2382 Saying 'N' here may make sense for embedded or server kernels. 2383 2384source "kernel/livepatch/Kconfig" 2385 2386endmenu 2387 2388config ARCH_HAS_ADD_PAGES 2389 def_bool y 2390 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2391 2392config ARCH_ENABLE_MEMORY_HOTPLUG 2393 def_bool y 2394 depends on X86_64 || (X86_32 && HIGHMEM) 2395 2396config ARCH_ENABLE_MEMORY_HOTREMOVE 2397 def_bool y 2398 depends on MEMORY_HOTPLUG 2399 2400config USE_PERCPU_NUMA_NODE_ID 2401 def_bool y 2402 depends on NUMA 2403 2404config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2405 def_bool y 2406 depends on X86_64 || X86_PAE 2407 2408config ARCH_ENABLE_HUGEPAGE_MIGRATION 2409 def_bool y 2410 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2411 2412config ARCH_ENABLE_THP_MIGRATION 2413 def_bool y 2414 depends on X86_64 && TRANSPARENT_HUGEPAGE 2415 2416menu "Power management and ACPI options" 2417 2418config ARCH_HIBERNATION_HEADER 2419 def_bool y 2420 depends on HIBERNATION 2421 2422source "kernel/power/Kconfig" 2423 2424source "drivers/acpi/Kconfig" 2425 2426source "drivers/sfi/Kconfig" 2427 2428config X86_APM_BOOT 2429 def_bool y 2430 depends on APM 2431 2432menuconfig APM 2433 tristate "APM (Advanced Power Management) BIOS support" 2434 depends on X86_32 && PM_SLEEP 2435 ---help--- 2436 APM is a BIOS specification for saving power using several different 2437 techniques. This is mostly useful for battery powered laptops with 2438 APM compliant BIOSes. If you say Y here, the system time will be 2439 reset after a RESUME operation, the /proc/apm device will provide 2440 battery status information, and user-space programs will receive 2441 notification of APM "events" (e.g. battery status change). 2442 2443 If you select "Y" here, you can disable actual use of the APM 2444 BIOS by passing the "apm=off" option to the kernel at boot time. 2445 2446 Note that the APM support is almost completely disabled for 2447 machines with more than one CPU. 2448 2449 In order to use APM, you will need supporting software. For location 2450 and more information, read <file:Documentation/power/apm-acpi.txt> 2451 and the Battery Powered Linux mini-HOWTO, available from 2452 <http://www.tldp.org/docs.html#howto>. 2453 2454 This driver does not spin down disk drives (see the hdparm(8) 2455 manpage ("man 8 hdparm") for that), and it doesn't turn off 2456 VESA-compliant "green" monitors. 2457 2458 This driver does not support the TI 4000M TravelMate and the ACER 2459 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2460 desktop machines also don't have compliant BIOSes, and this driver 2461 may cause those machines to panic during the boot phase. 2462 2463 Generally, if you don't have a battery in your machine, there isn't 2464 much point in using this driver and you should say N. If you get 2465 random kernel OOPSes or reboots that don't seem to be related to 2466 anything, try disabling/enabling this option (or disabling/enabling 2467 APM in your BIOS). 2468 2469 Some other things you should try when experiencing seemingly random, 2470 "weird" problems: 2471 2472 1) make sure that you have enough swap space and that it is 2473 enabled. 2474 2) pass the "no-hlt" option to the kernel 2475 3) switch on floating point emulation in the kernel and pass 2476 the "no387" option to the kernel 2477 4) pass the "floppy=nodma" option to the kernel 2478 5) pass the "mem=4M" option to the kernel (thereby disabling 2479 all but the first 4 MB of RAM) 2480 6) make sure that the CPU is not over clocked. 2481 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2482 8) disable the cache from your BIOS settings 2483 9) install a fan for the video card or exchange video RAM 2484 10) install a better fan for the CPU 2485 11) exchange RAM chips 2486 12) exchange the motherboard. 2487 2488 To compile this driver as a module, choose M here: the 2489 module will be called apm. 2490 2491if APM 2492 2493config APM_IGNORE_USER_SUSPEND 2494 bool "Ignore USER SUSPEND" 2495 ---help--- 2496 This option will ignore USER SUSPEND requests. On machines with a 2497 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2498 series notebooks, it is necessary to say Y because of a BIOS bug. 2499 2500config APM_DO_ENABLE 2501 bool "Enable PM at boot time" 2502 ---help--- 2503 Enable APM features at boot time. From page 36 of the APM BIOS 2504 specification: "When disabled, the APM BIOS does not automatically 2505 power manage devices, enter the Standby State, enter the Suspend 2506 State, or take power saving steps in response to CPU Idle calls." 2507 This driver will make CPU Idle calls when Linux is idle (unless this 2508 feature is turned off -- see "Do CPU IDLE calls", below). This 2509 should always save battery power, but more complicated APM features 2510 will be dependent on your BIOS implementation. You may need to turn 2511 this option off if your computer hangs at boot time when using APM 2512 support, or if it beeps continuously instead of suspending. Turn 2513 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2514 T400CDT. This is off by default since most machines do fine without 2515 this feature. 2516 2517config APM_CPU_IDLE 2518 depends on CPU_IDLE 2519 bool "Make CPU Idle calls when idle" 2520 ---help--- 2521 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2522 On some machines, this can activate improved power savings, such as 2523 a slowed CPU clock rate, when the machine is idle. These idle calls 2524 are made after the idle loop has run for some length of time (e.g., 2525 333 mS). On some machines, this will cause a hang at boot time or 2526 whenever the CPU becomes idle. (On machines with more than one CPU, 2527 this option does nothing.) 2528 2529config APM_DISPLAY_BLANK 2530 bool "Enable console blanking using APM" 2531 ---help--- 2532 Enable console blanking using the APM. Some laptops can use this to 2533 turn off the LCD backlight when the screen blanker of the Linux 2534 virtual console blanks the screen. Note that this is only used by 2535 the virtual console screen blanker, and won't turn off the backlight 2536 when using the X Window system. This also doesn't have anything to 2537 do with your VESA-compliant power-saving monitor. Further, this 2538 option doesn't work for all laptops -- it might not turn off your 2539 backlight at all, or it might print a lot of errors to the console, 2540 especially if you are using gpm. 2541 2542config APM_ALLOW_INTS 2543 bool "Allow interrupts during APM BIOS calls" 2544 ---help--- 2545 Normally we disable external interrupts while we are making calls to 2546 the APM BIOS as a measure to lessen the effects of a badly behaving 2547 BIOS implementation. The BIOS should reenable interrupts if it 2548 needs to. Unfortunately, some BIOSes do not -- especially those in 2549 many of the newer IBM Thinkpads. If you experience hangs when you 2550 suspend, try setting this to Y. Otherwise, say N. 2551 2552endif # APM 2553 2554source "drivers/cpufreq/Kconfig" 2555 2556source "drivers/cpuidle/Kconfig" 2557 2558source "drivers/idle/Kconfig" 2559 2560endmenu 2561 2562 2563menu "Bus options (PCI etc.)" 2564 2565config PCI 2566 bool "PCI support" 2567 default y 2568 ---help--- 2569 Find out whether you have a PCI motherboard. PCI is the name of a 2570 bus system, i.e. the way the CPU talks to the other stuff inside 2571 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2572 VESA. If you have PCI, say Y, otherwise N. 2573 2574choice 2575 prompt "PCI access mode" 2576 depends on X86_32 && PCI 2577 default PCI_GOANY 2578 ---help--- 2579 On PCI systems, the BIOS can be used to detect the PCI devices and 2580 determine their configuration. However, some old PCI motherboards 2581 have BIOS bugs and may crash if this is done. Also, some embedded 2582 PCI-based systems don't have any BIOS at all. Linux can also try to 2583 detect the PCI hardware directly without using the BIOS. 2584 2585 With this option, you can specify how Linux should detect the 2586 PCI devices. If you choose "BIOS", the BIOS will be used, 2587 if you choose "Direct", the BIOS won't be used, and if you 2588 choose "MMConfig", then PCI Express MMCONFIG will be used. 2589 If you choose "Any", the kernel will try MMCONFIG, then the 2590 direct access method and falls back to the BIOS if that doesn't 2591 work. If unsure, go with the default, which is "Any". 2592 2593config PCI_GOBIOS 2594 bool "BIOS" 2595 2596config PCI_GOMMCONFIG 2597 bool "MMConfig" 2598 2599config PCI_GODIRECT 2600 bool "Direct" 2601 2602config PCI_GOOLPC 2603 bool "OLPC XO-1" 2604 depends on OLPC 2605 2606config PCI_GOANY 2607 bool "Any" 2608 2609endchoice 2610 2611config PCI_BIOS 2612 def_bool y 2613 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2614 2615# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2616config PCI_DIRECT 2617 def_bool y 2618 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2619 2620config PCI_MMCONFIG 2621 bool "Support mmconfig PCI config space access" if X86_64 2622 default y 2623 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2624 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2625 2626config PCI_OLPC 2627 def_bool y 2628 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2629 2630config PCI_XEN 2631 def_bool y 2632 depends on PCI && XEN 2633 select SWIOTLB_XEN 2634 2635config PCI_DOMAINS 2636 def_bool y 2637 depends on PCI 2638 2639config MMCONF_FAM10H 2640 def_bool y 2641 depends on X86_64 && PCI_MMCONFIG && ACPI 2642 2643config PCI_CNB20LE_QUIRK 2644 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2645 depends on PCI 2646 help 2647 Read the PCI windows out of the CNB20LE host bridge. This allows 2648 PCI hotplug to work on systems with the CNB20LE chipset which do 2649 not have ACPI. 2650 2651 There's no public spec for this chipset, and this functionality 2652 is known to be incomplete. 2653 2654 You should say N unless you know you need this. 2655 2656source "drivers/pci/Kconfig" 2657 2658config ISA_BUS 2659 bool "ISA bus support on modern systems" if EXPERT 2660 help 2661 Expose ISA bus device drivers and options available for selection and 2662 configuration. Enable this option if your target machine has an ISA 2663 bus. ISA is an older system, displaced by PCI and newer bus 2664 architectures -- if your target machine is modern, it probably does 2665 not have an ISA bus. 2666 2667 If unsure, say N. 2668 2669# x86_64 have no ISA slots, but can have ISA-style DMA. 2670config ISA_DMA_API 2671 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2672 default y 2673 help 2674 Enables ISA-style DMA support for devices requiring such controllers. 2675 If unsure, say Y. 2676 2677if X86_32 2678 2679config ISA 2680 bool "ISA support" 2681 ---help--- 2682 Find out whether you have ISA slots on your motherboard. ISA is the 2683 name of a bus system, i.e. the way the CPU talks to the other stuff 2684 inside your box. Other bus systems are PCI, EISA, MicroChannel 2685 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2686 newer boards don't support it. If you have ISA, say Y, otherwise N. 2687 2688config EISA 2689 bool "EISA support" 2690 depends on ISA 2691 ---help--- 2692 The Extended Industry Standard Architecture (EISA) bus was 2693 developed as an open alternative to the IBM MicroChannel bus. 2694 2695 The EISA bus provided some of the features of the IBM MicroChannel 2696 bus while maintaining backward compatibility with cards made for 2697 the older ISA bus. The EISA bus saw limited use between 1988 and 2698 1995 when it was made obsolete by the PCI bus. 2699 2700 Say Y here if you are building a kernel for an EISA-based machine. 2701 2702 Otherwise, say N. 2703 2704source "drivers/eisa/Kconfig" 2705 2706config SCx200 2707 tristate "NatSemi SCx200 support" 2708 ---help--- 2709 This provides basic support for National Semiconductor's 2710 (now AMD's) Geode processors. The driver probes for the 2711 PCI-IDs of several on-chip devices, so its a good dependency 2712 for other scx200_* drivers. 2713 2714 If compiled as a module, the driver is named scx200. 2715 2716config SCx200HR_TIMER 2717 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2718 depends on SCx200 2719 default y 2720 ---help--- 2721 This driver provides a clocksource built upon the on-chip 2722 27MHz high-resolution timer. Its also a workaround for 2723 NSC Geode SC-1100's buggy TSC, which loses time when the 2724 processor goes idle (as is done by the scheduler). The 2725 other workaround is idle=poll boot option. 2726 2727config OLPC 2728 bool "One Laptop Per Child support" 2729 depends on !X86_PAE 2730 select GPIOLIB 2731 select OF 2732 select OF_PROMTREE 2733 select IRQ_DOMAIN 2734 ---help--- 2735 Add support for detecting the unique features of the OLPC 2736 XO hardware. 2737 2738config OLPC_XO1_PM 2739 bool "OLPC XO-1 Power Management" 2740 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2741 ---help--- 2742 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2743 2744config OLPC_XO1_RTC 2745 bool "OLPC XO-1 Real Time Clock" 2746 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2747 ---help--- 2748 Add support for the XO-1 real time clock, which can be used as a 2749 programmable wakeup source. 2750 2751config OLPC_XO1_SCI 2752 bool "OLPC XO-1 SCI extras" 2753 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2754 depends on INPUT=y 2755 select POWER_SUPPLY 2756 ---help--- 2757 Add support for SCI-based features of the OLPC XO-1 laptop: 2758 - EC-driven system wakeups 2759 - Power button 2760 - Ebook switch 2761 - Lid switch 2762 - AC adapter status updates 2763 - Battery status updates 2764 2765config OLPC_XO15_SCI 2766 bool "OLPC XO-1.5 SCI extras" 2767 depends on OLPC && ACPI 2768 select POWER_SUPPLY 2769 ---help--- 2770 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2771 - EC-driven system wakeups 2772 - AC adapter status updates 2773 - Battery status updates 2774 2775config ALIX 2776 bool "PCEngines ALIX System Support (LED setup)" 2777 select GPIOLIB 2778 ---help--- 2779 This option enables system support for the PCEngines ALIX. 2780 At present this just sets up LEDs for GPIO control on 2781 ALIX2/3/6 boards. However, other system specific setup should 2782 get added here. 2783 2784 Note: You must still enable the drivers for GPIO and LED support 2785 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2786 2787 Note: You have to set alix.force=1 for boards with Award BIOS. 2788 2789config NET5501 2790 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2791 select GPIOLIB 2792 ---help--- 2793 This option enables system support for the Soekris Engineering net5501. 2794 2795config GEOS 2796 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2797 select GPIOLIB 2798 depends on DMI 2799 ---help--- 2800 This option enables system support for the Traverse Technologies GEOS. 2801 2802config TS5500 2803 bool "Technologic Systems TS-5500 platform support" 2804 depends on MELAN 2805 select CHECK_SIGNATURE 2806 select NEW_LEDS 2807 select LEDS_CLASS 2808 ---help--- 2809 This option enables system support for the Technologic Systems TS-5500. 2810 2811endif # X86_32 2812 2813config AMD_NB 2814 def_bool y 2815 depends on CPU_SUP_AMD && PCI 2816 2817source "drivers/pcmcia/Kconfig" 2818 2819config RAPIDIO 2820 tristate "RapidIO support" 2821 depends on PCI 2822 help 2823 If enabled this option will include drivers and the core 2824 infrastructure code to support RapidIO interconnect devices. 2825 2826source "drivers/rapidio/Kconfig" 2827 2828config X86_SYSFB 2829 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2830 help 2831 Firmwares often provide initial graphics framebuffers so the BIOS, 2832 bootloader or kernel can show basic video-output during boot for 2833 user-guidance and debugging. Historically, x86 used the VESA BIOS 2834 Extensions and EFI-framebuffers for this, which are mostly limited 2835 to x86. 2836 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2837 framebuffers so the new generic system-framebuffer drivers can be 2838 used on x86. If the framebuffer is not compatible with the generic 2839 modes, it is advertised as fallback platform framebuffer so legacy 2840 drivers like efifb, vesafb and uvesafb can pick it up. 2841 If this option is not selected, all system framebuffers are always 2842 marked as fallback platform framebuffers as usual. 2843 2844 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2845 not be able to pick up generic system framebuffers if this option 2846 is selected. You are highly encouraged to enable simplefb as 2847 replacement if you select this option. simplefb can correctly deal 2848 with generic system framebuffers. But you should still keep vesafb 2849 and others enabled as fallback if a system framebuffer is 2850 incompatible with simplefb. 2851 2852 If unsure, say Y. 2853 2854endmenu 2855 2856 2857menu "Binary Emulations" 2858 2859config IA32_EMULATION 2860 bool "IA32 Emulation" 2861 depends on X86_64 2862 select ARCH_WANT_OLD_COMPAT_IPC 2863 select BINFMT_ELF 2864 select COMPAT_BINFMT_ELF 2865 select COMPAT_OLD_SIGACTION 2866 ---help--- 2867 Include code to run legacy 32-bit programs under a 2868 64-bit kernel. You should likely turn this on, unless you're 2869 100% sure that you don't have any 32-bit programs left. 2870 2871config IA32_AOUT 2872 tristate "IA32 a.out support" 2873 depends on IA32_EMULATION 2874 ---help--- 2875 Support old a.out binaries in the 32bit emulation. 2876 2877config X86_X32 2878 bool "x32 ABI for 64-bit mode" 2879 depends on X86_64 2880 ---help--- 2881 Include code to run binaries for the x32 native 32-bit ABI 2882 for 64-bit processors. An x32 process gets access to the 2883 full 64-bit register file and wide data path while leaving 2884 pointers at 32 bits for smaller memory footprint. 2885 2886 You will need a recent binutils (2.22 or later) with 2887 elf32_x86_64 support enabled to compile a kernel with this 2888 option set. 2889 2890config COMPAT_32 2891 def_bool y 2892 depends on IA32_EMULATION || X86_32 2893 select HAVE_UID16 2894 select OLD_SIGSUSPEND3 2895 2896config COMPAT 2897 def_bool y 2898 depends on IA32_EMULATION || X86_X32 2899 2900if COMPAT 2901config COMPAT_FOR_U64_ALIGNMENT 2902 def_bool y 2903 2904config SYSVIPC_COMPAT 2905 def_bool y 2906 depends on SYSVIPC 2907endif 2908 2909endmenu 2910 2911 2912config HAVE_ATOMIC_IOMAP 2913 def_bool y 2914 depends on X86_32 2915 2916config X86_DEV_DMA_OPS 2917 bool 2918 depends on X86_64 || STA2X11 2919 2920config X86_DMA_REMAP 2921 bool 2922 depends on STA2X11 2923 2924config HAVE_GENERIC_GUP 2925 def_bool y 2926 2927source "drivers/firmware/Kconfig" 2928 2929source "arch/x86/kvm/Kconfig" 2930