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_DISCARD_MEMBLOCK 52 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 53 select ARCH_HAS_DEBUG_VIRTUAL 54 select ARCH_HAS_DEVMEM_IS_ALLOWED 55 select ARCH_HAS_ELF_RANDOMIZE 56 select ARCH_HAS_FAST_MULTIPLIER 57 select ARCH_HAS_FILTER_PGPROT 58 select ARCH_HAS_FORTIFY_SOURCE 59 select ARCH_HAS_GCOV_PROFILE_ALL 60 select ARCH_HAS_KCOV if X86_64 61 select ARCH_HAS_MEMBARRIER_SYNC_CORE 62 select ARCH_HAS_PMEM_API if X86_64 63 select ARCH_HAS_PTE_SPECIAL 64 select ARCH_HAS_REFCOUNT 65 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 66 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE 67 select ARCH_HAS_SET_MEMORY 68 select ARCH_HAS_SG_CHAIN 69 select ARCH_HAS_STRICT_KERNEL_RWX 70 select ARCH_HAS_STRICT_MODULE_RWX 71 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 72 select ARCH_HAS_UBSAN_SANITIZE_ALL 73 select ARCH_HAS_ZONE_DEVICE if X86_64 74 select ARCH_HAVE_NMI_SAFE_CMPXCHG 75 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 76 select ARCH_MIGHT_HAVE_PC_PARPORT 77 select ARCH_MIGHT_HAVE_PC_SERIO 78 select ARCH_SUPPORTS_ACPI 79 select ARCH_SUPPORTS_ATOMIC_RMW 80 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 81 select ARCH_USE_BUILTIN_BSWAP 82 select ARCH_USE_QUEUED_RWLOCKS 83 select ARCH_USE_QUEUED_SPINLOCKS 84 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 85 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 86 select ARCH_WANTS_THP_SWAP if X86_64 87 select BUILDTIME_EXTABLE_SORT 88 select CLKEVT_I8253 89 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 90 select CLOCKSOURCE_WATCHDOG 91 select DCACHE_WORD_ACCESS 92 select DMA_DIRECT_OPS 93 select EDAC_ATOMIC_SCRUB 94 select EDAC_SUPPORT 95 select GENERIC_CLOCKEVENTS 96 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 97 select GENERIC_CLOCKEVENTS_MIN_ADJUST 98 select GENERIC_CMOS_UPDATE 99 select GENERIC_CPU_AUTOPROBE 100 select GENERIC_CPU_VULNERABILITIES 101 select GENERIC_EARLY_IOREMAP 102 select GENERIC_FIND_FIRST_BIT 103 select GENERIC_IOMAP 104 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 105 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 106 select GENERIC_IRQ_MIGRATION if SMP 107 select GENERIC_IRQ_PROBE 108 select GENERIC_IRQ_RESERVATION_MODE 109 select GENERIC_IRQ_SHOW 110 select GENERIC_PENDING_IRQ if SMP 111 select GENERIC_SMP_IDLE_THREAD 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select GENERIC_TIME_VSYSCALL 115 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 116 select HAVE_ACPI_APEI if ACPI 117 select HAVE_ACPI_APEI_NMI if ACPI 118 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 119 select HAVE_ARCH_AUDITSYSCALL 120 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 121 select HAVE_ARCH_JUMP_LABEL 122 select HAVE_ARCH_KASAN if X86_64 123 select HAVE_ARCH_KGDB 124 select HAVE_ARCH_MMAP_RND_BITS if MMU 125 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 126 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 127 select HAVE_ARCH_PREL32_RELOCATIONS 128 select HAVE_ARCH_SECCOMP_FILTER 129 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 130 select HAVE_ARCH_TRACEHOOK 131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 133 select HAVE_ARCH_VMAP_STACK if X86_64 134 select HAVE_ARCH_WITHIN_STACK_FRAMES 135 select HAVE_CMPXCHG_DOUBLE 136 select HAVE_CMPXCHG_LOCAL 137 select HAVE_CONTEXT_TRACKING if X86_64 138 select HAVE_COPY_THREAD_TLS 139 select HAVE_C_RECORDMCOUNT 140 select HAVE_DEBUG_KMEMLEAK 141 select HAVE_DEBUG_STACKOVERFLOW 142 select HAVE_DMA_CONTIGUOUS 143 select HAVE_DYNAMIC_FTRACE 144 select HAVE_DYNAMIC_FTRACE_WITH_REGS 145 select HAVE_EBPF_JIT 146 select HAVE_EFFICIENT_UNALIGNED_ACCESS 147 select HAVE_EXIT_THREAD 148 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 149 select HAVE_FTRACE_MCOUNT_RECORD 150 select HAVE_FUNCTION_GRAPH_TRACER 151 select HAVE_FUNCTION_TRACER 152 select HAVE_GCC_PLUGINS 153 select HAVE_HW_BREAKPOINT 154 select HAVE_IDE 155 select HAVE_IOREMAP_PROT 156 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 157 select HAVE_IRQ_TIME_ACCOUNTING 158 select HAVE_KERNEL_BZIP2 159 select HAVE_KERNEL_GZIP 160 select HAVE_KERNEL_LZ4 161 select HAVE_KERNEL_LZMA 162 select HAVE_KERNEL_LZO 163 select HAVE_KERNEL_XZ 164 select HAVE_KPROBES 165 select HAVE_KPROBES_ON_FTRACE 166 select HAVE_FUNCTION_ERROR_INJECTION 167 select HAVE_KRETPROBES 168 select HAVE_KVM 169 select HAVE_LIVEPATCH if X86_64 170 select HAVE_MEMBLOCK 171 select HAVE_MEMBLOCK_NODE_MAP 172 select HAVE_MIXED_BREAKPOINTS_REGS 173 select HAVE_MOD_ARCH_SPECIFIC 174 select HAVE_NMI 175 select HAVE_OPROFILE 176 select HAVE_OPTPROBES 177 select HAVE_PCSPKR_PLATFORM 178 select HAVE_PERF_EVENTS 179 select HAVE_PERF_EVENTS_NMI 180 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 181 select HAVE_PERF_REGS 182 select HAVE_PERF_USER_STACK_DUMP 183 select HAVE_RCU_TABLE_FREE if PARAVIRT 184 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE 185 select HAVE_REGS_AND_STACK_ACCESS_API 186 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 187 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 188 select HAVE_STACK_VALIDATION if X86_64 189 select HAVE_RSEQ 190 select HAVE_SYSCALL_TRACEPOINTS 191 select HAVE_UNSTABLE_SCHED_CLOCK 192 select HAVE_USER_RETURN_NOTIFIER 193 select HOTPLUG_SMT if SMP 194 select IRQ_FORCED_THREADING 195 select NEED_SG_DMA_LENGTH 196 select PCI_LOCKLESS_CONFIG 197 select PERF_EVENTS 198 select RTC_LIB 199 select RTC_MC146818_LIB 200 select SPARSE_IRQ 201 select SRCU 202 select SYSCTL_EXCEPTION_TRACE 203 select THREAD_INFO_IN_TASK 204 select USER_STACKTRACE_SUPPORT 205 select VIRT_TO_BUS 206 select X86_FEATURE_NAMES if PROC_FS 207 208config INSTRUCTION_DECODER 209 def_bool y 210 depends on KPROBES || PERF_EVENTS || UPROBES 211 212config OUTPUT_FORMAT 213 string 214 default "elf32-i386" if X86_32 215 default "elf64-x86-64" if X86_64 216 217config ARCH_DEFCONFIG 218 string 219 default "arch/x86/configs/i386_defconfig" if X86_32 220 default "arch/x86/configs/x86_64_defconfig" if X86_64 221 222config LOCKDEP_SUPPORT 223 def_bool y 224 225config STACKTRACE_SUPPORT 226 def_bool y 227 228config MMU 229 def_bool y 230 231config ARCH_MMAP_RND_BITS_MIN 232 default 28 if 64BIT 233 default 8 234 235config ARCH_MMAP_RND_BITS_MAX 236 default 32 if 64BIT 237 default 16 238 239config ARCH_MMAP_RND_COMPAT_BITS_MIN 240 default 8 241 242config ARCH_MMAP_RND_COMPAT_BITS_MAX 243 default 16 244 245config SBUS 246 bool 247 248config GENERIC_ISA_DMA 249 def_bool y 250 depends on ISA_DMA_API 251 252config GENERIC_BUG 253 def_bool y 254 depends on BUG 255 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 256 257config GENERIC_BUG_RELATIVE_POINTERS 258 bool 259 260config GENERIC_HWEIGHT 261 def_bool y 262 263config ARCH_MAY_HAVE_PC_FDC 264 def_bool y 265 depends on ISA_DMA_API 266 267config RWSEM_XCHGADD_ALGORITHM 268 def_bool y 269 270config GENERIC_CALIBRATE_DELAY 271 def_bool y 272 273config ARCH_HAS_CPU_RELAX 274 def_bool y 275 276config ARCH_HAS_CACHE_LINE_SIZE 277 def_bool y 278 279config ARCH_HAS_FILTER_PGPROT 280 def_bool y 281 282config HAVE_SETUP_PER_CPU_AREA 283 def_bool y 284 285config NEED_PER_CPU_EMBED_FIRST_CHUNK 286 def_bool y 287 288config NEED_PER_CPU_PAGE_FIRST_CHUNK 289 def_bool y 290 291config ARCH_HIBERNATION_POSSIBLE 292 def_bool y 293 294config ARCH_SUSPEND_POSSIBLE 295 def_bool y 296 297config ARCH_WANT_HUGE_PMD_SHARE 298 def_bool y 299 300config ARCH_WANT_GENERAL_HUGETLB 301 def_bool y 302 303config ZONE_DMA32 304 def_bool y if X86_64 305 306config AUDIT_ARCH 307 def_bool y if X86_64 308 309config ARCH_SUPPORTS_OPTIMIZED_INLINING 310 def_bool y 311 312config ARCH_SUPPORTS_DEBUG_PAGEALLOC 313 def_bool y 314 315config KASAN_SHADOW_OFFSET 316 hex 317 depends on KASAN 318 default 0xdffffc0000000000 319 320config HAVE_INTEL_TXT 321 def_bool y 322 depends on INTEL_IOMMU && ACPI 323 324config X86_32_SMP 325 def_bool y 326 depends on X86_32 && SMP 327 328config X86_64_SMP 329 def_bool y 330 depends on X86_64 && SMP 331 332config X86_32_LAZY_GS 333 def_bool y 334 depends on X86_32 && !STACKPROTECTOR 335 336config ARCH_SUPPORTS_UPROBES 337 def_bool y 338 339config FIX_EARLYCON_MEM 340 def_bool y 341 342config DYNAMIC_PHYSICAL_MASK 343 bool 344 345config PGTABLE_LEVELS 346 int 347 default 5 if X86_5LEVEL 348 default 4 if X86_64 349 default 3 if X86_PAE 350 default 2 351 352config CC_HAS_SANE_STACKPROTECTOR 353 bool 354 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 355 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 356 help 357 We have to make sure stack protector is unconditionally disabled if 358 the compiler produces broken code. 359 360menu "Processor type and features" 361 362config ZONE_DMA 363 bool "DMA memory allocation support" if EXPERT 364 default y 365 help 366 DMA memory allocation support allows devices with less than 32-bit 367 addressing to allocate within the first 16MB of address space. 368 Disable if no such devices will be used. 369 370 If unsure, say Y. 371 372config SMP 373 bool "Symmetric multi-processing support" 374 ---help--- 375 This enables support for systems with more than one CPU. If you have 376 a system with only one CPU, say N. If you have a system with more 377 than one CPU, say Y. 378 379 If you say N here, the kernel will run on uni- and multiprocessor 380 machines, but will use only one CPU of a multiprocessor machine. If 381 you say Y here, the kernel will run on many, but not all, 382 uniprocessor machines. On a uniprocessor machine, the kernel 383 will run faster if you say N here. 384 385 Note that if you say Y here and choose architecture "586" or 386 "Pentium" under "Processor family", the kernel will not work on 486 387 architectures. Similarly, multiprocessor kernels for the "PPro" 388 architecture may not work on all Pentium based boards. 389 390 People using multiprocessor machines who say Y here should also say 391 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 392 Management" code will be disabled if you say Y here. 393 394 See also <file:Documentation/x86/i386/IO-APIC.txt>, 395 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at 396 <http://www.tldp.org/docs.html#howto>. 397 398 If you don't know what to do here, say N. 399 400config X86_FEATURE_NAMES 401 bool "Processor feature human-readable names" if EMBEDDED 402 default y 403 ---help--- 404 This option compiles in a table of x86 feature bits and corresponding 405 names. This is required to support /proc/cpuinfo and a few kernel 406 messages. You can disable this to save space, at the expense of 407 making those few kernel messages show numeric feature bits instead. 408 409 If in doubt, say Y. 410 411config X86_X2APIC 412 bool "Support x2apic" 413 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 414 ---help--- 415 This enables x2apic support on CPUs that have this feature. 416 417 This allows 32-bit apic IDs (so it can support very large systems), 418 and accesses the local apic via MSRs not via mmio. 419 420 If you don't know what to do here, say N. 421 422config X86_MPPARSE 423 bool "Enable MPS table" if ACPI || SFI 424 default y 425 depends on X86_LOCAL_APIC 426 ---help--- 427 For old smp systems that do not have proper acpi support. Newer systems 428 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 429 430config GOLDFISH 431 def_bool y 432 depends on X86_GOLDFISH 433 434config RETPOLINE 435 bool "Avoid speculative indirect branches in kernel" 436 default y 437 select STACK_VALIDATION if HAVE_STACK_VALIDATION 438 help 439 Compile kernel with the retpoline compiler options to guard against 440 kernel-to-user data leaks by avoiding speculative indirect 441 branches. Requires a compiler with -mindirect-branch=thunk-extern 442 support for full protection. The kernel may run slower. 443 444 Without compiler support, at least indirect branches in assembler 445 code are eliminated. Since this includes the syscall entry path, 446 it is not entirely pointless. 447 448config INTEL_RDT 449 bool "Intel Resource Director Technology support" 450 default n 451 depends on X86 && CPU_SUP_INTEL 452 select KERNFS 453 help 454 Select to enable resource allocation and monitoring which are 455 sub-features of Intel Resource Director Technology(RDT). More 456 information about RDT can be found in the Intel x86 457 Architecture Software Developer Manual. 458 459 Say N if unsure. 460 461if X86_32 462config X86_BIGSMP 463 bool "Support for big SMP systems with more than 8 CPUs" 464 depends on SMP 465 ---help--- 466 This option is needed for the systems that have more than 8 CPUs 467 468config X86_EXTENDED_PLATFORM 469 bool "Support for extended (non-PC) x86 platforms" 470 default y 471 ---help--- 472 If you disable this option then the kernel will only support 473 standard PC platforms. (which covers the vast majority of 474 systems out there.) 475 476 If you enable this option then you'll be able to select support 477 for the following (non-PC) 32 bit x86 platforms: 478 Goldfish (Android emulator) 479 AMD Elan 480 RDC R-321x SoC 481 SGI 320/540 (Visual Workstation) 482 STA2X11-based (e.g. Northville) 483 Moorestown MID devices 484 485 If you have one of these systems, or if you want to build a 486 generic distribution kernel, say Y here - otherwise say N. 487endif 488 489if X86_64 490config X86_EXTENDED_PLATFORM 491 bool "Support for extended (non-PC) x86 platforms" 492 default y 493 ---help--- 494 If you disable this option then the kernel will only support 495 standard PC platforms. (which covers the vast majority of 496 systems out there.) 497 498 If you enable this option then you'll be able to select support 499 for the following (non-PC) 64 bit x86 platforms: 500 Numascale NumaChip 501 ScaleMP vSMP 502 SGI Ultraviolet 503 504 If you have one of these systems, or if you want to build a 505 generic distribution kernel, say Y here - otherwise say N. 506endif 507# This is an alphabetically sorted list of 64 bit extended platforms 508# Please maintain the alphabetic order if and when there are additions 509config X86_NUMACHIP 510 bool "Numascale NumaChip" 511 depends on X86_64 512 depends on X86_EXTENDED_PLATFORM 513 depends on NUMA 514 depends on SMP 515 depends on X86_X2APIC 516 depends on PCI_MMCONFIG 517 ---help--- 518 Adds support for Numascale NumaChip large-SMP systems. Needed to 519 enable more than ~168 cores. 520 If you don't have one of these, you should say N here. 521 522config X86_VSMP 523 bool "ScaleMP vSMP" 524 select HYPERVISOR_GUEST 525 select PARAVIRT 526 depends on X86_64 && PCI 527 depends on X86_EXTENDED_PLATFORM 528 depends on SMP 529 ---help--- 530 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 531 supposed to run on these EM64T-based machines. Only choose this option 532 if you have one of these machines. 533 534config X86_UV 535 bool "SGI Ultraviolet" 536 depends on X86_64 537 depends on X86_EXTENDED_PLATFORM 538 depends on NUMA 539 depends on EFI 540 depends on X86_X2APIC 541 depends on PCI 542 ---help--- 543 This option is needed in order to support SGI Ultraviolet systems. 544 If you don't have one of these, you should say N here. 545 546# Following is an alphabetically sorted list of 32 bit extended platforms 547# Please maintain the alphabetic order if and when there are additions 548 549config X86_GOLDFISH 550 bool "Goldfish (Virtual Platform)" 551 depends on X86_EXTENDED_PLATFORM 552 ---help--- 553 Enable support for the Goldfish virtual platform used primarily 554 for Android development. Unless you are building for the Android 555 Goldfish emulator say N here. 556 557config X86_INTEL_CE 558 bool "CE4100 TV platform" 559 depends on PCI 560 depends on PCI_GODIRECT 561 depends on X86_IO_APIC 562 depends on X86_32 563 depends on X86_EXTENDED_PLATFORM 564 select X86_REBOOTFIXUPS 565 select OF 566 select OF_EARLY_FLATTREE 567 ---help--- 568 Select for the Intel CE media processor (CE4100) SOC. 569 This option compiles in support for the CE4100 SOC for settop 570 boxes and media devices. 571 572config X86_INTEL_MID 573 bool "Intel MID platform support" 574 depends on X86_EXTENDED_PLATFORM 575 depends on X86_PLATFORM_DEVICES 576 depends on PCI 577 depends on X86_64 || (PCI_GOANY && X86_32) 578 depends on X86_IO_APIC 579 select SFI 580 select I2C 581 select DW_APB_TIMER 582 select APB_TIMER 583 select INTEL_SCU_IPC 584 select MFD_INTEL_MSIC 585 ---help--- 586 Select to build a kernel capable of supporting Intel MID (Mobile 587 Internet Device) platform systems which do not have the PCI legacy 588 interfaces. If you are building for a PC class system say N here. 589 590 Intel MID platforms are based on an Intel processor and chipset which 591 consume less power than most of the x86 derivatives. 592 593config X86_INTEL_QUARK 594 bool "Intel Quark platform support" 595 depends on X86_32 596 depends on X86_EXTENDED_PLATFORM 597 depends on X86_PLATFORM_DEVICES 598 depends on X86_TSC 599 depends on PCI 600 depends on PCI_GOANY 601 depends on X86_IO_APIC 602 select IOSF_MBI 603 select INTEL_IMR 604 select COMMON_CLK 605 ---help--- 606 Select to include support for Quark X1000 SoC. 607 Say Y here if you have a Quark based system such as the Arduino 608 compatible Intel Galileo. 609 610config X86_INTEL_LPSS 611 bool "Intel Low Power Subsystem Support" 612 depends on X86 && ACPI 613 select COMMON_CLK 614 select PINCTRL 615 select IOSF_MBI 616 ---help--- 617 Select to build support for Intel Low Power Subsystem such as 618 found on Intel Lynxpoint PCH. Selecting this option enables 619 things like clock tree (common clock framework) and pincontrol 620 which are needed by the LPSS peripheral drivers. 621 622config X86_AMD_PLATFORM_DEVICE 623 bool "AMD ACPI2Platform devices support" 624 depends on ACPI 625 select COMMON_CLK 626 select PINCTRL 627 ---help--- 628 Select to interpret AMD specific ACPI device to platform device 629 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 630 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 631 implemented under PINCTRL subsystem. 632 633config IOSF_MBI 634 tristate "Intel SoC IOSF Sideband support for SoC platforms" 635 depends on PCI 636 ---help--- 637 This option enables sideband register access support for Intel SoC 638 platforms. On these platforms the IOSF sideband is used in lieu of 639 MSR's for some register accesses, mostly but not limited to thermal 640 and power. Drivers may query the availability of this device to 641 determine if they need the sideband in order to work on these 642 platforms. The sideband is available on the following SoC products. 643 This list is not meant to be exclusive. 644 - BayTrail 645 - Braswell 646 - Quark 647 648 You should say Y if you are running a kernel on one of these SoC's. 649 650config IOSF_MBI_DEBUG 651 bool "Enable IOSF sideband access through debugfs" 652 depends on IOSF_MBI && DEBUG_FS 653 ---help--- 654 Select this option to expose the IOSF sideband access registers (MCR, 655 MDR, MCRX) through debugfs to write and read register information from 656 different units on the SoC. This is most useful for obtaining device 657 state information for debug and analysis. As this is a general access 658 mechanism, users of this option would have specific knowledge of the 659 device they want to access. 660 661 If you don't require the option or are in doubt, say N. 662 663config X86_RDC321X 664 bool "RDC R-321x SoC" 665 depends on X86_32 666 depends on X86_EXTENDED_PLATFORM 667 select M486 668 select X86_REBOOTFIXUPS 669 ---help--- 670 This option is needed for RDC R-321x system-on-chip, also known 671 as R-8610-(G). 672 If you don't have one of these chips, you should say N here. 673 674config X86_32_NON_STANDARD 675 bool "Support non-standard 32-bit SMP architectures" 676 depends on X86_32 && SMP 677 depends on X86_EXTENDED_PLATFORM 678 ---help--- 679 This option compiles in the bigsmp and STA2X11 default 680 subarchitectures. It is intended for a generic binary 681 kernel. If you select them all, kernel will probe it one by 682 one and will fallback to default. 683 684# Alphabetically sorted list of Non standard 32 bit platforms 685 686config X86_SUPPORTS_MEMORY_FAILURE 687 def_bool y 688 # MCE code calls memory_failure(): 689 depends on X86_MCE 690 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 691 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 692 depends on X86_64 || !SPARSEMEM 693 select ARCH_SUPPORTS_MEMORY_FAILURE 694 695config STA2X11 696 bool "STA2X11 Companion Chip Support" 697 depends on X86_32_NON_STANDARD && PCI 698 select ARCH_HAS_PHYS_TO_DMA 699 select X86_DEV_DMA_OPS 700 select X86_DMA_REMAP 701 select SWIOTLB 702 select MFD_STA2X11 703 select GPIOLIB 704 default n 705 ---help--- 706 This adds support for boards based on the STA2X11 IO-Hub, 707 a.k.a. "ConneXt". The chip is used in place of the standard 708 PC chipset, so all "standard" peripherals are missing. If this 709 option is selected the kernel will still be able to boot on 710 standard PC machines. 711 712config X86_32_IRIS 713 tristate "Eurobraille/Iris poweroff module" 714 depends on X86_32 715 ---help--- 716 The Iris machines from EuroBraille do not have APM or ACPI support 717 to shut themselves down properly. A special I/O sequence is 718 needed to do so, which is what this module does at 719 kernel shutdown. 720 721 This is only for Iris machines from EuroBraille. 722 723 If unused, say N. 724 725config SCHED_OMIT_FRAME_POINTER 726 def_bool y 727 prompt "Single-depth WCHAN output" 728 depends on X86 729 ---help--- 730 Calculate simpler /proc/<PID>/wchan values. If this option 731 is disabled then wchan values will recurse back to the 732 caller function. This provides more accurate wchan values, 733 at the expense of slightly more scheduling overhead. 734 735 If in doubt, say "Y". 736 737menuconfig HYPERVISOR_GUEST 738 bool "Linux guest support" 739 ---help--- 740 Say Y here to enable options for running Linux under various hyper- 741 visors. This option enables basic hypervisor detection and platform 742 setup. 743 744 If you say N, all options in this submenu will be skipped and 745 disabled, and Linux guest support won't be built in. 746 747if HYPERVISOR_GUEST 748 749config PARAVIRT 750 bool "Enable paravirtualization code" 751 ---help--- 752 This changes the kernel so it can modify itself when it is run 753 under a hypervisor, potentially improving performance significantly 754 over full virtualization. However, when run without a hypervisor 755 the kernel is theoretically slower and slightly larger. 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 default n 803 ---help--- 804 This option enables collection of various statistics for KVM guest. 805 Statistics are displayed in debugfs filesystem. Enabling this option 806 may incur significant overhead. 807 808config PARAVIRT_TIME_ACCOUNTING 809 bool "Paravirtual steal time accounting" 810 depends on PARAVIRT 811 default n 812 ---help--- 813 Select this option to enable fine granularity task steal time 814 accounting. Time spent executing other tasks in parallel with 815 the current vCPU is discounted from the vCPU power. To account for 816 that, there can be a small performance impact. 817 818 If in doubt, say N here. 819 820config PARAVIRT_CLOCK 821 bool 822 823config JAILHOUSE_GUEST 824 bool "Jailhouse non-root cell support" 825 depends on X86_64 && PCI 826 select X86_PM_TIMER 827 ---help--- 828 This option allows to run Linux as guest in a Jailhouse non-root 829 cell. You can leave this option disabled if you only want to start 830 Jailhouse and run Linux afterwards in the root cell. 831 832endif #HYPERVISOR_GUEST 833 834config NO_BOOTMEM 835 def_bool y 836 837source "arch/x86/Kconfig.cpu" 838 839config HPET_TIMER 840 def_bool X86_64 841 prompt "HPET Timer Support" if X86_32 842 ---help--- 843 Use the IA-PC HPET (High Precision Event Timer) to manage 844 time in preference to the PIT and RTC, if a HPET is 845 present. 846 HPET is the next generation timer replacing legacy 8254s. 847 The HPET provides a stable time base on SMP 848 systems, unlike the TSC, but it is more expensive to access, 849 as it is off-chip. The interface used is documented 850 in the HPET spec, revision 1. 851 852 You can safely choose Y here. However, HPET will only be 853 activated if the platform and the BIOS support this feature. 854 Otherwise the 8254 will be used for timing services. 855 856 Choose N to continue using the legacy 8254 timer. 857 858config HPET_EMULATE_RTC 859 def_bool y 860 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 861 862config APB_TIMER 863 def_bool y if X86_INTEL_MID 864 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 865 select DW_APB_TIMER 866 depends on X86_INTEL_MID && SFI 867 help 868 APB timer is the replacement for 8254, HPET on X86 MID platforms. 869 The APBT provides a stable time base on SMP 870 systems, unlike the TSC, but it is more expensive to access, 871 as it is off-chip. APB timers are always running regardless of CPU 872 C states, they are used as per CPU clockevent device when possible. 873 874# Mark as expert because too many people got it wrong. 875# The code disables itself when not needed. 876config DMI 877 default y 878 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 879 bool "Enable DMI scanning" if EXPERT 880 ---help--- 881 Enabled scanning of DMI to identify machine quirks. Say Y 882 here unless you have verified that your setup is not 883 affected by entries in the DMI blacklist. Required by PNP 884 BIOS code. 885 886config GART_IOMMU 887 bool "Old AMD GART IOMMU support" 888 select IOMMU_HELPER 889 select SWIOTLB 890 depends on X86_64 && PCI && AMD_NB 891 ---help--- 892 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 893 GART based hardware IOMMUs. 894 895 The GART supports full DMA access for devices with 32-bit access 896 limitations, on systems with more than 3 GB. This is usually needed 897 for USB, sound, many IDE/SATA chipsets and some other devices. 898 899 Newer systems typically have a modern AMD IOMMU, supported via 900 the CONFIG_AMD_IOMMU=y config option. 901 902 In normal configurations this driver is only active when needed: 903 there's more than 3 GB of memory and the system contains a 904 32-bit limited device. 905 906 If unsure, say Y. 907 908config CALGARY_IOMMU 909 bool "IBM Calgary IOMMU support" 910 select IOMMU_HELPER 911 select SWIOTLB 912 depends on X86_64 && PCI 913 ---help--- 914 Support for hardware IOMMUs in IBM's xSeries x366 and x460 915 systems. Needed to run systems with more than 3GB of memory 916 properly with 32-bit PCI devices that do not support DAC 917 (Double Address Cycle). Calgary also supports bus level 918 isolation, where all DMAs pass through the IOMMU. This 919 prevents them from going anywhere except their intended 920 destination. This catches hard-to-find kernel bugs and 921 mis-behaving drivers and devices that do not use the DMA-API 922 properly to set up their DMA buffers. The IOMMU can be 923 turned off at boot time with the iommu=off parameter. 924 Normally the kernel will make the right choice by itself. 925 If unsure, say Y. 926 927config CALGARY_IOMMU_ENABLED_BY_DEFAULT 928 def_bool y 929 prompt "Should Calgary be enabled by default?" 930 depends on CALGARY_IOMMU 931 ---help--- 932 Should Calgary be enabled by default? if you choose 'y', Calgary 933 will be used (if it exists). If you choose 'n', Calgary will not be 934 used even if it exists. If you choose 'n' and would like to use 935 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 936 If unsure, say Y. 937 938config MAXSMP 939 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 940 depends on X86_64 && SMP && DEBUG_KERNEL 941 select CPUMASK_OFFSTACK 942 ---help--- 943 Enable maximum number of CPUS and NUMA Nodes for this architecture. 944 If unsure, say N. 945 946# 947# The maximum number of CPUs supported: 948# 949# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 950# and which can be configured interactively in the 951# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 952# 953# The ranges are different on 32-bit and 64-bit kernels, depending on 954# hardware capabilities and scalability features of the kernel. 955# 956# ( If MAXSMP is enabled we just use the highest possible value and disable 957# interactive configuration. ) 958# 959 960config NR_CPUS_RANGE_BEGIN 961 int 962 default NR_CPUS_RANGE_END if MAXSMP 963 default 1 if !SMP 964 default 2 965 966config NR_CPUS_RANGE_END 967 int 968 depends on X86_32 969 default 64 if SMP && X86_BIGSMP 970 default 8 if SMP && !X86_BIGSMP 971 default 1 if !SMP 972 973config NR_CPUS_RANGE_END 974 int 975 depends on X86_64 976 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK) 977 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK) 978 default 1 if !SMP 979 980config NR_CPUS_DEFAULT 981 int 982 depends on X86_32 983 default 32 if X86_BIGSMP 984 default 8 if SMP 985 default 1 if !SMP 986 987config NR_CPUS_DEFAULT 988 int 989 depends on X86_64 990 default 8192 if MAXSMP 991 default 64 if SMP 992 default 1 if !SMP 993 994config NR_CPUS 995 int "Maximum number of CPUs" if SMP && !MAXSMP 996 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 997 default NR_CPUS_DEFAULT 998 ---help--- 999 This allows you to specify the maximum number of CPUs which this 1000 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 1001 supported value is 8192, otherwise the maximum value is 512. The 1002 minimum value which makes sense is 2. 1003 1004 This is purely to save memory: each supported CPU adds about 8KB 1005 to the kernel image. 1006 1007config SCHED_SMT 1008 bool "SMT (Hyperthreading) scheduler support" 1009 depends on SMP 1010 ---help--- 1011 SMT scheduler support improves the CPU scheduler's decision making 1012 when dealing with Intel Pentium 4 chips with HyperThreading at a 1013 cost of slightly increased overhead in some places. If unsure say 1014 N here. 1015 1016config SCHED_MC 1017 def_bool y 1018 prompt "Multi-core scheduler support" 1019 depends on SMP 1020 ---help--- 1021 Multi-core scheduler support improves the CPU scheduler's decision 1022 making when dealing with multi-core CPU chips at a cost of slightly 1023 increased overhead in some places. If unsure say N here. 1024 1025config SCHED_MC_PRIO 1026 bool "CPU core priorities scheduler support" 1027 depends on SCHED_MC && CPU_SUP_INTEL 1028 select X86_INTEL_PSTATE 1029 select CPU_FREQ 1030 default y 1031 ---help--- 1032 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1033 core ordering determined at manufacturing time, which allows 1034 certain cores to reach higher turbo frequencies (when running 1035 single threaded workloads) than others. 1036 1037 Enabling this kernel feature teaches the scheduler about 1038 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1039 scheduler's CPU selection logic accordingly, so that higher 1040 overall system performance can be achieved. 1041 1042 This feature will have no effect on CPUs without this feature. 1043 1044 If unsure say Y here. 1045 1046config UP_LATE_INIT 1047 def_bool y 1048 depends on !SMP && X86_LOCAL_APIC 1049 1050config X86_UP_APIC 1051 bool "Local APIC support on uniprocessors" if !PCI_MSI 1052 default PCI_MSI 1053 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1054 ---help--- 1055 A local APIC (Advanced Programmable Interrupt Controller) is an 1056 integrated interrupt controller in the CPU. If you have a single-CPU 1057 system which has a processor with a local APIC, you can say Y here to 1058 enable and use it. If you say Y here even though your machine doesn't 1059 have a local APIC, then the kernel will still run with no slowdown at 1060 all. The local APIC supports CPU-generated self-interrupts (timer, 1061 performance counters), and the NMI watchdog which detects hard 1062 lockups. 1063 1064config X86_UP_IOAPIC 1065 bool "IO-APIC support on uniprocessors" 1066 depends on X86_UP_APIC 1067 ---help--- 1068 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1069 SMP-capable replacement for PC-style interrupt controllers. Most 1070 SMP systems and many recent uniprocessor systems have one. 1071 1072 If you have a single-CPU system with an IO-APIC, you can say Y here 1073 to use it. If you say Y here even though your machine doesn't have 1074 an IO-APIC, then the kernel will still run with no slowdown at all. 1075 1076config X86_LOCAL_APIC 1077 def_bool y 1078 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1079 select IRQ_DOMAIN_HIERARCHY 1080 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1081 1082config X86_IO_APIC 1083 def_bool y 1084 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1085 1086config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1087 bool "Reroute for broken boot IRQs" 1088 depends on X86_IO_APIC 1089 ---help--- 1090 This option enables a workaround that fixes a source of 1091 spurious interrupts. This is recommended when threaded 1092 interrupt handling is used on systems where the generation of 1093 superfluous "boot interrupts" cannot be disabled. 1094 1095 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1096 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1097 kernel does during interrupt handling). On chipsets where this 1098 boot IRQ generation cannot be disabled, this workaround keeps 1099 the original IRQ line masked so that only the equivalent "boot 1100 IRQ" is delivered to the CPUs. The workaround also tells the 1101 kernel to set up the IRQ handler on the boot IRQ line. In this 1102 way only one interrupt is delivered to the kernel. Otherwise 1103 the spurious second interrupt may cause the kernel to bring 1104 down (vital) interrupt lines. 1105 1106 Only affects "broken" chipsets. Interrupt sharing may be 1107 increased on these systems. 1108 1109config X86_MCE 1110 bool "Machine Check / overheating reporting" 1111 select GENERIC_ALLOCATOR 1112 default y 1113 ---help--- 1114 Machine Check support allows the processor to notify the 1115 kernel if it detects a problem (e.g. overheating, data corruption). 1116 The action the kernel takes depends on the severity of the problem, 1117 ranging from warning messages to halting the machine. 1118 1119config X86_MCELOG_LEGACY 1120 bool "Support for deprecated /dev/mcelog character device" 1121 depends on X86_MCE 1122 ---help--- 1123 Enable support for /dev/mcelog which is needed by the old mcelog 1124 userspace logging daemon. Consider switching to the new generation 1125 rasdaemon solution. 1126 1127config X86_MCE_INTEL 1128 def_bool y 1129 prompt "Intel MCE features" 1130 depends on X86_MCE && X86_LOCAL_APIC 1131 ---help--- 1132 Additional support for intel specific MCE features such as 1133 the thermal monitor. 1134 1135config X86_MCE_AMD 1136 def_bool y 1137 prompt "AMD MCE features" 1138 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1139 ---help--- 1140 Additional support for AMD specific MCE features such as 1141 the DRAM Error Threshold. 1142 1143config X86_ANCIENT_MCE 1144 bool "Support for old Pentium 5 / WinChip machine checks" 1145 depends on X86_32 && X86_MCE 1146 ---help--- 1147 Include support for machine check handling on old Pentium 5 or WinChip 1148 systems. These typically need to be enabled explicitly on the command 1149 line. 1150 1151config X86_MCE_THRESHOLD 1152 depends on X86_MCE_AMD || X86_MCE_INTEL 1153 def_bool y 1154 1155config X86_MCE_INJECT 1156 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1157 tristate "Machine check injector support" 1158 ---help--- 1159 Provide support for injecting machine checks for testing purposes. 1160 If you don't know what a machine check is and you don't do kernel 1161 QA it is safe to say n. 1162 1163config X86_THERMAL_VECTOR 1164 def_bool y 1165 depends on X86_MCE_INTEL 1166 1167source "arch/x86/events/Kconfig" 1168 1169config X86_LEGACY_VM86 1170 bool "Legacy VM86 support" 1171 default n 1172 depends on X86_32 1173 ---help--- 1174 This option allows user programs to put the CPU into V8086 1175 mode, which is an 80286-era approximation of 16-bit real mode. 1176 1177 Some very old versions of X and/or vbetool require this option 1178 for user mode setting. Similarly, DOSEMU will use it if 1179 available to accelerate real mode DOS programs. However, any 1180 recent version of DOSEMU, X, or vbetool should be fully 1181 functional even without kernel VM86 support, as they will all 1182 fall back to software emulation. Nevertheless, if you are using 1183 a 16-bit DOS program where 16-bit performance matters, vm86 1184 mode might be faster than emulation and you might want to 1185 enable this option. 1186 1187 Note that any app that works on a 64-bit kernel is unlikely to 1188 need this option, as 64-bit kernels don't, and can't, support 1189 V8086 mode. This option is also unrelated to 16-bit protected 1190 mode and is not needed to run most 16-bit programs under Wine. 1191 1192 Enabling this option increases the complexity of the kernel 1193 and slows down exception handling a tiny bit. 1194 1195 If unsure, say N here. 1196 1197config VM86 1198 bool 1199 default X86_LEGACY_VM86 1200 1201config X86_16BIT 1202 bool "Enable support for 16-bit segments" if EXPERT 1203 default y 1204 depends on MODIFY_LDT_SYSCALL 1205 ---help--- 1206 This option is required by programs like Wine to run 16-bit 1207 protected mode legacy code on x86 processors. Disabling 1208 this option saves about 300 bytes on i386, or around 6K text 1209 plus 16K runtime memory on x86-64, 1210 1211config X86_ESPFIX32 1212 def_bool y 1213 depends on X86_16BIT && X86_32 1214 1215config X86_ESPFIX64 1216 def_bool y 1217 depends on X86_16BIT && X86_64 1218 1219config X86_VSYSCALL_EMULATION 1220 bool "Enable vsyscall emulation" if EXPERT 1221 default y 1222 depends on X86_64 1223 ---help--- 1224 This enables emulation of the legacy vsyscall page. Disabling 1225 it is roughly equivalent to booting with vsyscall=none, except 1226 that it will also disable the helpful warning if a program 1227 tries to use a vsyscall. With this option set to N, offending 1228 programs will just segfault, citing addresses of the form 1229 0xffffffffff600?00. 1230 1231 This option is required by many programs built before 2013, and 1232 care should be used even with newer programs if set to N. 1233 1234 Disabling this option saves about 7K of kernel size and 1235 possibly 4K of additional runtime pagetable memory. 1236 1237config TOSHIBA 1238 tristate "Toshiba Laptop support" 1239 depends on X86_32 1240 ---help--- 1241 This adds a driver to safely access the System Management Mode of 1242 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1243 not work on models with a Phoenix BIOS. The System Management Mode 1244 is used to set the BIOS and power saving options on Toshiba portables. 1245 1246 For information on utilities to make use of this driver see the 1247 Toshiba Linux utilities web site at: 1248 <http://www.buzzard.org.uk/toshiba/>. 1249 1250 Say Y if you intend to run this kernel on a Toshiba portable. 1251 Say N otherwise. 1252 1253config I8K 1254 tristate "Dell i8k legacy laptop support" 1255 select HWMON 1256 select SENSORS_DELL_SMM 1257 ---help--- 1258 This option enables legacy /proc/i8k userspace interface in hwmon 1259 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1260 temperature and allows controlling fan speeds of Dell laptops via 1261 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1262 it reports also power and hotkey status. For fan speed control is 1263 needed userspace package i8kutils. 1264 1265 Say Y if you intend to run this kernel on old Dell laptops or want to 1266 use userspace package i8kutils. 1267 Say N otherwise. 1268 1269config X86_REBOOTFIXUPS 1270 bool "Enable X86 board specific fixups for reboot" 1271 depends on X86_32 1272 ---help--- 1273 This enables chipset and/or board specific fixups to be done 1274 in order to get reboot to work correctly. This is only needed on 1275 some combinations of hardware and BIOS. The symptom, for which 1276 this config is intended, is when reboot ends with a stalled/hung 1277 system. 1278 1279 Currently, the only fixup is for the Geode machines using 1280 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1281 1282 Say Y if you want to enable the fixup. Currently, it's safe to 1283 enable this option even if you don't need it. 1284 Say N otherwise. 1285 1286config MICROCODE 1287 bool "CPU microcode loading support" 1288 default y 1289 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1290 select FW_LOADER 1291 ---help--- 1292 If you say Y here, you will be able to update the microcode on 1293 Intel and AMD processors. The Intel support is for the IA32 family, 1294 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1295 AMD support is for families 0x10 and later. You will obviously need 1296 the actual microcode binary data itself which is not shipped with 1297 the Linux kernel. 1298 1299 The preferred method to load microcode from a detached initrd is described 1300 in Documentation/x86/microcode.txt. For that you need to enable 1301 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1302 initrd for microcode blobs. 1303 1304 In addition, you can build the microcode into the kernel. For that you 1305 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1306 config option. 1307 1308config MICROCODE_INTEL 1309 bool "Intel microcode loading support" 1310 depends on MICROCODE 1311 default MICROCODE 1312 select FW_LOADER 1313 ---help--- 1314 This options enables microcode patch loading support for Intel 1315 processors. 1316 1317 For the current Intel microcode data package go to 1318 <https://downloadcenter.intel.com> and search for 1319 'Linux Processor Microcode Data File'. 1320 1321config MICROCODE_AMD 1322 bool "AMD microcode loading support" 1323 depends on MICROCODE 1324 select FW_LOADER 1325 ---help--- 1326 If you select this option, microcode patch loading support for AMD 1327 processors will be enabled. 1328 1329config MICROCODE_OLD_INTERFACE 1330 def_bool y 1331 depends on MICROCODE 1332 1333config X86_MSR 1334 tristate "/dev/cpu/*/msr - Model-specific register support" 1335 ---help--- 1336 This device gives privileged processes access to the x86 1337 Model-Specific Registers (MSRs). It is a character device with 1338 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1339 MSR accesses are directed to a specific CPU on multi-processor 1340 systems. 1341 1342config X86_CPUID 1343 tristate "/dev/cpu/*/cpuid - CPU information support" 1344 ---help--- 1345 This device gives processes access to the x86 CPUID instruction to 1346 be executed on a specific processor. It is a character device 1347 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1348 /dev/cpu/31/cpuid. 1349 1350choice 1351 prompt "High Memory Support" 1352 default HIGHMEM4G 1353 depends on X86_32 1354 1355config NOHIGHMEM 1356 bool "off" 1357 ---help--- 1358 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1359 However, the address space of 32-bit x86 processors is only 4 1360 Gigabytes large. That means that, if you have a large amount of 1361 physical memory, not all of it can be "permanently mapped" by the 1362 kernel. The physical memory that's not permanently mapped is called 1363 "high memory". 1364 1365 If you are compiling a kernel which will never run on a machine with 1366 more than 1 Gigabyte total physical RAM, answer "off" here (default 1367 choice and suitable for most users). This will result in a "3GB/1GB" 1368 split: 3GB are mapped so that each process sees a 3GB virtual memory 1369 space and the remaining part of the 4GB virtual memory space is used 1370 by the kernel to permanently map as much physical memory as 1371 possible. 1372 1373 If the machine has between 1 and 4 Gigabytes physical RAM, then 1374 answer "4GB" here. 1375 1376 If more than 4 Gigabytes is used then answer "64GB" here. This 1377 selection turns Intel PAE (Physical Address Extension) mode on. 1378 PAE implements 3-level paging on IA32 processors. PAE is fully 1379 supported by Linux, PAE mode is implemented on all recent Intel 1380 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1381 then the kernel will not boot on CPUs that don't support PAE! 1382 1383 The actual amount of total physical memory will either be 1384 auto detected or can be forced by using a kernel command line option 1385 such as "mem=256M". (Try "man bootparam" or see the documentation of 1386 your boot loader (lilo or loadlin) about how to pass options to the 1387 kernel at boot time.) 1388 1389 If unsure, say "off". 1390 1391config HIGHMEM4G 1392 bool "4GB" 1393 ---help--- 1394 Select this if you have a 32-bit processor and between 1 and 4 1395 gigabytes of physical RAM. 1396 1397config HIGHMEM64G 1398 bool "64GB" 1399 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1400 select X86_PAE 1401 ---help--- 1402 Select this if you have a 32-bit processor and more than 4 1403 gigabytes of physical RAM. 1404 1405endchoice 1406 1407choice 1408 prompt "Memory split" if EXPERT 1409 default VMSPLIT_3G 1410 depends on X86_32 1411 ---help--- 1412 Select the desired split between kernel and user memory. 1413 1414 If the address range available to the kernel is less than the 1415 physical memory installed, the remaining memory will be available 1416 as "high memory". Accessing high memory is a little more costly 1417 than low memory, as it needs to be mapped into the kernel first. 1418 Note that increasing the kernel address space limits the range 1419 available to user programs, making the address space there 1420 tighter. Selecting anything other than the default 3G/1G split 1421 will also likely make your kernel incompatible with binary-only 1422 kernel modules. 1423 1424 If you are not absolutely sure what you are doing, leave this 1425 option alone! 1426 1427 config VMSPLIT_3G 1428 bool "3G/1G user/kernel split" 1429 config VMSPLIT_3G_OPT 1430 depends on !X86_PAE 1431 bool "3G/1G user/kernel split (for full 1G low memory)" 1432 config VMSPLIT_2G 1433 bool "2G/2G user/kernel split" 1434 config VMSPLIT_2G_OPT 1435 depends on !X86_PAE 1436 bool "2G/2G user/kernel split (for full 2G low memory)" 1437 config VMSPLIT_1G 1438 bool "1G/3G user/kernel split" 1439endchoice 1440 1441config PAGE_OFFSET 1442 hex 1443 default 0xB0000000 if VMSPLIT_3G_OPT 1444 default 0x80000000 if VMSPLIT_2G 1445 default 0x78000000 if VMSPLIT_2G_OPT 1446 default 0x40000000 if VMSPLIT_1G 1447 default 0xC0000000 1448 depends on X86_32 1449 1450config HIGHMEM 1451 def_bool y 1452 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1453 1454config X86_PAE 1455 bool "PAE (Physical Address Extension) Support" 1456 depends on X86_32 && !HIGHMEM4G 1457 select PHYS_ADDR_T_64BIT 1458 select SWIOTLB 1459 ---help--- 1460 PAE is required for NX support, and furthermore enables 1461 larger swapspace support for non-overcommit purposes. It 1462 has the cost of more pagetable lookup overhead, and also 1463 consumes more pagetable space per process. 1464 1465config X86_5LEVEL 1466 bool "Enable 5-level page tables support" 1467 select DYNAMIC_MEMORY_LAYOUT 1468 select SPARSEMEM_VMEMMAP 1469 depends on X86_64 1470 ---help--- 1471 5-level paging enables access to larger address space: 1472 upto 128 PiB of virtual address space and 4 PiB of 1473 physical address space. 1474 1475 It will be supported by future Intel CPUs. 1476 1477 A kernel with the option enabled can be booted on machines that 1478 support 4- or 5-level paging. 1479 1480 See Documentation/x86/x86_64/5level-paging.txt for more 1481 information. 1482 1483 Say N if unsure. 1484 1485config X86_DIRECT_GBPAGES 1486 def_bool y 1487 depends on X86_64 && !DEBUG_PAGEALLOC 1488 ---help--- 1489 Certain kernel features effectively disable kernel 1490 linear 1 GB mappings (even if the CPU otherwise 1491 supports them), so don't confuse the user by printing 1492 that we have them enabled. 1493 1494config ARCH_HAS_MEM_ENCRYPT 1495 def_bool y 1496 1497config AMD_MEM_ENCRYPT 1498 bool "AMD Secure Memory Encryption (SME) support" 1499 depends on X86_64 && CPU_SUP_AMD 1500 select DYNAMIC_PHYSICAL_MASK 1501 ---help--- 1502 Say yes to enable support for the encryption of system memory. 1503 This requires an AMD processor that supports Secure Memory 1504 Encryption (SME). 1505 1506config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1507 bool "Activate AMD Secure Memory Encryption (SME) by default" 1508 default y 1509 depends on AMD_MEM_ENCRYPT 1510 ---help--- 1511 Say yes to have system memory encrypted by default if running on 1512 an AMD processor that supports Secure Memory Encryption (SME). 1513 1514 If set to Y, then the encryption of system memory can be 1515 deactivated with the mem_encrypt=off command line option. 1516 1517 If set to N, then the encryption of system memory can be 1518 activated with the mem_encrypt=on command line option. 1519 1520config ARCH_USE_MEMREMAP_PROT 1521 def_bool y 1522 depends on AMD_MEM_ENCRYPT 1523 1524# Common NUMA Features 1525config NUMA 1526 bool "Numa Memory Allocation and Scheduler Support" 1527 depends on SMP 1528 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1529 default y if X86_BIGSMP 1530 ---help--- 1531 Enable NUMA (Non Uniform Memory Access) support. 1532 1533 The kernel will try to allocate memory used by a CPU on the 1534 local memory controller of the CPU and add some more 1535 NUMA awareness to the kernel. 1536 1537 For 64-bit this is recommended if the system is Intel Core i7 1538 (or later), AMD Opteron, or EM64T NUMA. 1539 1540 For 32-bit this is only needed if you boot a 32-bit 1541 kernel on a 64-bit NUMA platform. 1542 1543 Otherwise, you should say N. 1544 1545config AMD_NUMA 1546 def_bool y 1547 prompt "Old style AMD Opteron NUMA detection" 1548 depends on X86_64 && NUMA && PCI 1549 ---help--- 1550 Enable AMD NUMA node topology detection. You should say Y here if 1551 you have a multi processor AMD system. This uses an old method to 1552 read the NUMA configuration directly from the builtin Northbridge 1553 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1554 which also takes priority if both are compiled in. 1555 1556config X86_64_ACPI_NUMA 1557 def_bool y 1558 prompt "ACPI NUMA detection" 1559 depends on X86_64 && NUMA && ACPI && PCI 1560 select ACPI_NUMA 1561 ---help--- 1562 Enable ACPI SRAT based node topology detection. 1563 1564# Some NUMA nodes have memory ranges that span 1565# other nodes. Even though a pfn is valid and 1566# between a node's start and end pfns, it may not 1567# reside on that node. See memmap_init_zone() 1568# for details. 1569config NODES_SPAN_OTHER_NODES 1570 def_bool y 1571 depends on X86_64_ACPI_NUMA 1572 1573config NUMA_EMU 1574 bool "NUMA emulation" 1575 depends on NUMA 1576 ---help--- 1577 Enable NUMA emulation. A flat machine will be split 1578 into virtual nodes when booted with "numa=fake=N", where N is the 1579 number of nodes. This is only useful for debugging. 1580 1581config NODES_SHIFT 1582 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1583 range 1 10 1584 default "10" if MAXSMP 1585 default "6" if X86_64 1586 default "3" 1587 depends on NEED_MULTIPLE_NODES 1588 ---help--- 1589 Specify the maximum number of NUMA Nodes available on the target 1590 system. Increases memory reserved to accommodate various tables. 1591 1592config ARCH_HAVE_MEMORY_PRESENT 1593 def_bool y 1594 depends on X86_32 && DISCONTIGMEM 1595 1596config ARCH_FLATMEM_ENABLE 1597 def_bool y 1598 depends on X86_32 && !NUMA 1599 1600config ARCH_DISCONTIGMEM_ENABLE 1601 def_bool y 1602 depends on NUMA && X86_32 1603 1604config ARCH_DISCONTIGMEM_DEFAULT 1605 def_bool y 1606 depends on NUMA && X86_32 1607 1608config ARCH_SPARSEMEM_ENABLE 1609 def_bool y 1610 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1611 select SPARSEMEM_STATIC if X86_32 1612 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1613 1614config ARCH_SPARSEMEM_DEFAULT 1615 def_bool y 1616 depends on X86_64 1617 1618config ARCH_SELECT_MEMORY_MODEL 1619 def_bool y 1620 depends on ARCH_SPARSEMEM_ENABLE 1621 1622config ARCH_MEMORY_PROBE 1623 bool "Enable sysfs memory/probe interface" 1624 depends on X86_64 && MEMORY_HOTPLUG 1625 help 1626 This option enables a sysfs memory/probe interface for testing. 1627 See Documentation/memory-hotplug.txt for more information. 1628 If you are unsure how to answer this question, answer N. 1629 1630config ARCH_PROC_KCORE_TEXT 1631 def_bool y 1632 depends on X86_64 && PROC_KCORE 1633 1634config ILLEGAL_POINTER_VALUE 1635 hex 1636 default 0 if X86_32 1637 default 0xdead000000000000 if X86_64 1638 1639config X86_PMEM_LEGACY_DEVICE 1640 bool 1641 1642config X86_PMEM_LEGACY 1643 tristate "Support non-standard NVDIMMs and ADR protected memory" 1644 depends on PHYS_ADDR_T_64BIT 1645 depends on BLK_DEV 1646 select X86_PMEM_LEGACY_DEVICE 1647 select LIBNVDIMM 1648 help 1649 Treat memory marked using the non-standard e820 type of 12 as used 1650 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1651 The kernel will offer these regions to the 'pmem' driver so 1652 they can be used for persistent storage. 1653 1654 Say Y if unsure. 1655 1656config HIGHPTE 1657 bool "Allocate 3rd-level pagetables from highmem" 1658 depends on HIGHMEM 1659 ---help--- 1660 The VM uses one page table entry for each page of physical memory. 1661 For systems with a lot of RAM, this can be wasteful of precious 1662 low memory. Setting this option will put user-space page table 1663 entries in high memory. 1664 1665config X86_CHECK_BIOS_CORRUPTION 1666 bool "Check for low memory corruption" 1667 ---help--- 1668 Periodically check for memory corruption in low memory, which 1669 is suspected to be caused by BIOS. Even when enabled in the 1670 configuration, it is disabled at runtime. Enable it by 1671 setting "memory_corruption_check=1" on the kernel command 1672 line. By default it scans the low 64k of memory every 60 1673 seconds; see the memory_corruption_check_size and 1674 memory_corruption_check_period parameters in 1675 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1676 1677 When enabled with the default parameters, this option has 1678 almost no overhead, as it reserves a relatively small amount 1679 of memory and scans it infrequently. It both detects corruption 1680 and prevents it from affecting the running system. 1681 1682 It is, however, intended as a diagnostic tool; if repeatable 1683 BIOS-originated corruption always affects the same memory, 1684 you can use memmap= to prevent the kernel from using that 1685 memory. 1686 1687config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1688 bool "Set the default setting of memory_corruption_check" 1689 depends on X86_CHECK_BIOS_CORRUPTION 1690 default y 1691 ---help--- 1692 Set whether the default state of memory_corruption_check is 1693 on or off. 1694 1695config X86_RESERVE_LOW 1696 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1697 default 64 1698 range 4 640 1699 ---help--- 1700 Specify the amount of low memory to reserve for the BIOS. 1701 1702 The first page contains BIOS data structures that the kernel 1703 must not use, so that page must always be reserved. 1704 1705 By default we reserve the first 64K of physical RAM, as a 1706 number of BIOSes are known to corrupt that memory range 1707 during events such as suspend/resume or monitor cable 1708 insertion, so it must not be used by the kernel. 1709 1710 You can set this to 4 if you are absolutely sure that you 1711 trust the BIOS to get all its memory reservations and usages 1712 right. If you know your BIOS have problems beyond the 1713 default 64K area, you can set this to 640 to avoid using the 1714 entire low memory range. 1715 1716 If you have doubts about the BIOS (e.g. suspend/resume does 1717 not work or there's kernel crashes after certain hardware 1718 hotplug events) then you might want to enable 1719 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1720 typical corruption patterns. 1721 1722 Leave this to the default value of 64 if you are unsure. 1723 1724config MATH_EMULATION 1725 bool 1726 depends on MODIFY_LDT_SYSCALL 1727 prompt "Math emulation" if X86_32 1728 ---help--- 1729 Linux can emulate a math coprocessor (used for floating point 1730 operations) if you don't have one. 486DX and Pentium processors have 1731 a math coprocessor built in, 486SX and 386 do not, unless you added 1732 a 487DX or 387, respectively. (The messages during boot time can 1733 give you some hints here ["man dmesg"].) Everyone needs either a 1734 coprocessor or this emulation. 1735 1736 If you don't have a math coprocessor, you need to say Y here; if you 1737 say Y here even though you have a coprocessor, the coprocessor will 1738 be used nevertheless. (This behavior can be changed with the kernel 1739 command line option "no387", which comes handy if your coprocessor 1740 is broken. Try "man bootparam" or see the documentation of your boot 1741 loader (lilo or loadlin) about how to pass options to the kernel at 1742 boot time.) This means that it is a good idea to say Y here if you 1743 intend to use this kernel on different machines. 1744 1745 More information about the internals of the Linux math coprocessor 1746 emulation can be found in <file:arch/x86/math-emu/README>. 1747 1748 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1749 kernel, it won't hurt. 1750 1751config MTRR 1752 def_bool y 1753 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1754 ---help--- 1755 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1756 the Memory Type Range Registers (MTRRs) may be used to control 1757 processor access to memory ranges. This is most useful if you have 1758 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1759 allows bus write transfers to be combined into a larger transfer 1760 before bursting over the PCI/AGP bus. This can increase performance 1761 of image write operations 2.5 times or more. Saying Y here creates a 1762 /proc/mtrr file which may be used to manipulate your processor's 1763 MTRRs. Typically the X server should use this. 1764 1765 This code has a reasonably generic interface so that similar 1766 control registers on other processors can be easily supported 1767 as well: 1768 1769 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1770 Registers (ARRs) which provide a similar functionality to MTRRs. For 1771 these, the ARRs are used to emulate the MTRRs. 1772 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1773 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1774 write-combining. All of these processors are supported by this code 1775 and it makes sense to say Y here if you have one of them. 1776 1777 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1778 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1779 can lead to all sorts of problems, so it's good to say Y here. 1780 1781 You can safely say Y even if your machine doesn't have MTRRs, you'll 1782 just add about 9 KB to your kernel. 1783 1784 See <file:Documentation/x86/mtrr.txt> for more information. 1785 1786config MTRR_SANITIZER 1787 def_bool y 1788 prompt "MTRR cleanup support" 1789 depends on MTRR 1790 ---help--- 1791 Convert MTRR layout from continuous to discrete, so X drivers can 1792 add writeback entries. 1793 1794 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1795 The largest mtrr entry size for a continuous block can be set with 1796 mtrr_chunk_size. 1797 1798 If unsure, say Y. 1799 1800config MTRR_SANITIZER_ENABLE_DEFAULT 1801 int "MTRR cleanup enable value (0-1)" 1802 range 0 1 1803 default "0" 1804 depends on MTRR_SANITIZER 1805 ---help--- 1806 Enable mtrr cleanup default value 1807 1808config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1809 int "MTRR cleanup spare reg num (0-7)" 1810 range 0 7 1811 default "1" 1812 depends on MTRR_SANITIZER 1813 ---help--- 1814 mtrr cleanup spare entries default, it can be changed via 1815 mtrr_spare_reg_nr=N on the kernel command line. 1816 1817config X86_PAT 1818 def_bool y 1819 prompt "x86 PAT support" if EXPERT 1820 depends on MTRR 1821 ---help--- 1822 Use PAT attributes to setup page level cache control. 1823 1824 PATs are the modern equivalents of MTRRs and are much more 1825 flexible than MTRRs. 1826 1827 Say N here if you see bootup problems (boot crash, boot hang, 1828 spontaneous reboots) or a non-working video driver. 1829 1830 If unsure, say Y. 1831 1832config ARCH_USES_PG_UNCACHED 1833 def_bool y 1834 depends on X86_PAT 1835 1836config ARCH_RANDOM 1837 def_bool y 1838 prompt "x86 architectural random number generator" if EXPERT 1839 ---help--- 1840 Enable the x86 architectural RDRAND instruction 1841 (Intel Bull Mountain technology) to generate random numbers. 1842 If supported, this is a high bandwidth, cryptographically 1843 secure hardware random number generator. 1844 1845config X86_SMAP 1846 def_bool y 1847 prompt "Supervisor Mode Access Prevention" if EXPERT 1848 ---help--- 1849 Supervisor Mode Access Prevention (SMAP) is a security 1850 feature in newer Intel processors. There is a small 1851 performance cost if this enabled and turned on; there is 1852 also a small increase in the kernel size if this is enabled. 1853 1854 If unsure, say Y. 1855 1856config X86_INTEL_UMIP 1857 def_bool y 1858 depends on CPU_SUP_INTEL 1859 prompt "Intel User Mode Instruction Prevention" if EXPERT 1860 ---help--- 1861 The User Mode Instruction Prevention (UMIP) is a security 1862 feature in newer Intel processors. If enabled, a general 1863 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1864 or STR instructions are executed in user mode. These instructions 1865 unnecessarily expose information about the hardware state. 1866 1867 The vast majority of applications do not use these instructions. 1868 For the very few that do, software emulation is provided in 1869 specific cases in protected and virtual-8086 modes. Emulated 1870 results are dummy. 1871 1872config X86_INTEL_MPX 1873 prompt "Intel MPX (Memory Protection Extensions)" 1874 def_bool n 1875 # Note: only available in 64-bit mode due to VMA flags shortage 1876 depends on CPU_SUP_INTEL && X86_64 1877 select ARCH_USES_HIGH_VMA_FLAGS 1878 ---help--- 1879 MPX provides hardware features that can be used in 1880 conjunction with compiler-instrumented code to check 1881 memory references. It is designed to detect buffer 1882 overflow or underflow bugs. 1883 1884 This option enables running applications which are 1885 instrumented or otherwise use MPX. It does not use MPX 1886 itself inside the kernel or to protect the kernel 1887 against bad memory references. 1888 1889 Enabling this option will make the kernel larger: 1890 ~8k of kernel text and 36 bytes of data on a 64-bit 1891 defconfig. It adds a long to the 'mm_struct' which 1892 will increase the kernel memory overhead of each 1893 process and adds some branches to paths used during 1894 exec() and munmap(). 1895 1896 For details, see Documentation/x86/intel_mpx.txt 1897 1898 If unsure, say N. 1899 1900config X86_INTEL_MEMORY_PROTECTION_KEYS 1901 prompt "Intel Memory Protection Keys" 1902 def_bool y 1903 # Note: only available in 64-bit mode 1904 depends on CPU_SUP_INTEL && X86_64 1905 select ARCH_USES_HIGH_VMA_FLAGS 1906 select ARCH_HAS_PKEYS 1907 ---help--- 1908 Memory Protection Keys provides a mechanism for enforcing 1909 page-based protections, but without requiring modification of the 1910 page tables when an application changes protection domains. 1911 1912 For details, see Documentation/x86/protection-keys.txt 1913 1914 If unsure, say y. 1915 1916config EFI 1917 bool "EFI runtime service support" 1918 depends on ACPI 1919 select UCS2_STRING 1920 select EFI_RUNTIME_WRAPPERS 1921 ---help--- 1922 This enables the kernel to use EFI runtime services that are 1923 available (such as the EFI variable services). 1924 1925 This option is only useful on systems that have EFI firmware. 1926 In addition, you should use the latest ELILO loader available 1927 at <http://elilo.sourceforge.net> in order to take advantage 1928 of EFI runtime services. However, even with this option, the 1929 resultant kernel should continue to boot on existing non-EFI 1930 platforms. 1931 1932config EFI_STUB 1933 bool "EFI stub support" 1934 depends on EFI && !X86_USE_3DNOW 1935 select RELOCATABLE 1936 ---help--- 1937 This kernel feature allows a bzImage to be loaded directly 1938 by EFI firmware without the use of a bootloader. 1939 1940 See Documentation/efi-stub.txt for more information. 1941 1942config EFI_MIXED 1943 bool "EFI mixed-mode support" 1944 depends on EFI_STUB && X86_64 1945 ---help--- 1946 Enabling this feature allows a 64-bit kernel to be booted 1947 on a 32-bit firmware, provided that your CPU supports 64-bit 1948 mode. 1949 1950 Note that it is not possible to boot a mixed-mode enabled 1951 kernel via the EFI boot stub - a bootloader that supports 1952 the EFI handover protocol must be used. 1953 1954 If unsure, say N. 1955 1956config SECCOMP 1957 def_bool y 1958 prompt "Enable seccomp to safely compute untrusted bytecode" 1959 ---help--- 1960 This kernel feature is useful for number crunching applications 1961 that may need to compute untrusted bytecode during their 1962 execution. By using pipes or other transports made available to 1963 the process as file descriptors supporting the read/write 1964 syscalls, it's possible to isolate those applications in 1965 their own address space using seccomp. Once seccomp is 1966 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1967 and the task is only allowed to execute a few safe syscalls 1968 defined by each seccomp mode. 1969 1970 If unsure, say Y. Only embedded should say N here. 1971 1972source kernel/Kconfig.hz 1973 1974config KEXEC 1975 bool "kexec system call" 1976 select KEXEC_CORE 1977 ---help--- 1978 kexec is a system call that implements the ability to shutdown your 1979 current kernel, and to start another kernel. It is like a reboot 1980 but it is independent of the system firmware. And like a reboot 1981 you can start any kernel with it, not just Linux. 1982 1983 The name comes from the similarity to the exec system call. 1984 1985 It is an ongoing process to be certain the hardware in a machine 1986 is properly shutdown, so do not be surprised if this code does not 1987 initially work for you. As of this writing the exact hardware 1988 interface is strongly in flux, so no good recommendation can be 1989 made. 1990 1991config KEXEC_FILE 1992 bool "kexec file based system call" 1993 select KEXEC_CORE 1994 select BUILD_BIN2C 1995 depends on X86_64 1996 depends on CRYPTO=y 1997 depends on CRYPTO_SHA256=y 1998 ---help--- 1999 This is new version of kexec system call. This system call is 2000 file based and takes file descriptors as system call argument 2001 for kernel and initramfs as opposed to list of segments as 2002 accepted by previous system call. 2003 2004config ARCH_HAS_KEXEC_PURGATORY 2005 def_bool KEXEC_FILE 2006 2007config KEXEC_VERIFY_SIG 2008 bool "Verify kernel signature during kexec_file_load() syscall" 2009 depends on KEXEC_FILE 2010 ---help--- 2011 This option makes kernel signature verification mandatory for 2012 the kexec_file_load() syscall. 2013 2014 In addition to that option, you need to enable signature 2015 verification for the corresponding kernel image type being 2016 loaded in order for this to work. 2017 2018config KEXEC_BZIMAGE_VERIFY_SIG 2019 bool "Enable bzImage signature verification support" 2020 depends on KEXEC_VERIFY_SIG 2021 depends on SIGNED_PE_FILE_VERIFICATION 2022 select SYSTEM_TRUSTED_KEYRING 2023 ---help--- 2024 Enable bzImage signature verification support. 2025 2026config CRASH_DUMP 2027 bool "kernel crash dumps" 2028 depends on X86_64 || (X86_32 && HIGHMEM) 2029 ---help--- 2030 Generate crash dump after being started by kexec. 2031 This should be normally only set in special crash dump kernels 2032 which are loaded in the main kernel with kexec-tools into 2033 a specially reserved region and then later executed after 2034 a crash by kdump/kexec. The crash dump kernel must be compiled 2035 to a memory address not used by the main kernel or BIOS using 2036 PHYSICAL_START, or it must be built as a relocatable image 2037 (CONFIG_RELOCATABLE=y). 2038 For more details see Documentation/kdump/kdump.txt 2039 2040config KEXEC_JUMP 2041 bool "kexec jump" 2042 depends on KEXEC && HIBERNATION 2043 ---help--- 2044 Jump between original kernel and kexeced kernel and invoke 2045 code in physical address mode via KEXEC 2046 2047config PHYSICAL_START 2048 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2049 default "0x1000000" 2050 ---help--- 2051 This gives the physical address where the kernel is loaded. 2052 2053 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2054 bzImage will decompress itself to above physical address and 2055 run from there. Otherwise, bzImage will run from the address where 2056 it has been loaded by the boot loader and will ignore above physical 2057 address. 2058 2059 In normal kdump cases one does not have to set/change this option 2060 as now bzImage can be compiled as a completely relocatable image 2061 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2062 address. This option is mainly useful for the folks who don't want 2063 to use a bzImage for capturing the crash dump and want to use a 2064 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2065 to be specifically compiled to run from a specific memory area 2066 (normally a reserved region) and this option comes handy. 2067 2068 So if you are using bzImage for capturing the crash dump, 2069 leave the value here unchanged to 0x1000000 and set 2070 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2071 for capturing the crash dump change this value to start of 2072 the reserved region. In other words, it can be set based on 2073 the "X" value as specified in the "crashkernel=YM@XM" 2074 command line boot parameter passed to the panic-ed 2075 kernel. Please take a look at Documentation/kdump/kdump.txt 2076 for more details about crash dumps. 2077 2078 Usage of bzImage for capturing the crash dump is recommended as 2079 one does not have to build two kernels. Same kernel can be used 2080 as production kernel and capture kernel. Above option should have 2081 gone away after relocatable bzImage support is introduced. But it 2082 is present because there are users out there who continue to use 2083 vmlinux for dump capture. This option should go away down the 2084 line. 2085 2086 Don't change this unless you know what you are doing. 2087 2088config RELOCATABLE 2089 bool "Build a relocatable kernel" 2090 default y 2091 ---help--- 2092 This builds a kernel image that retains relocation information 2093 so it can be loaded someplace besides the default 1MB. 2094 The relocations tend to make the kernel binary about 10% larger, 2095 but are discarded at runtime. 2096 2097 One use is for the kexec on panic case where the recovery kernel 2098 must live at a different physical address than the primary 2099 kernel. 2100 2101 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2102 it has been loaded at and the compile time physical address 2103 (CONFIG_PHYSICAL_START) is used as the minimum location. 2104 2105config RANDOMIZE_BASE 2106 bool "Randomize the address of the kernel image (KASLR)" 2107 depends on RELOCATABLE 2108 default y 2109 ---help--- 2110 In support of Kernel Address Space Layout Randomization (KASLR), 2111 this randomizes the physical address at which the kernel image 2112 is decompressed and the virtual address where the kernel 2113 image is mapped, as a security feature that deters exploit 2114 attempts relying on knowledge of the location of kernel 2115 code internals. 2116 2117 On 64-bit, the kernel physical and virtual addresses are 2118 randomized separately. The physical address will be anywhere 2119 between 16MB and the top of physical memory (up to 64TB). The 2120 virtual address will be randomized from 16MB up to 1GB (9 bits 2121 of entropy). Note that this also reduces the memory space 2122 available to kernel modules from 1.5GB to 1GB. 2123 2124 On 32-bit, the kernel physical and virtual addresses are 2125 randomized together. They will be randomized from 16MB up to 2126 512MB (8 bits of entropy). 2127 2128 Entropy is generated using the RDRAND instruction if it is 2129 supported. If RDTSC is supported, its value is mixed into 2130 the entropy pool as well. If neither RDRAND nor RDTSC are 2131 supported, then entropy is read from the i8254 timer. The 2132 usable entropy is limited by the kernel being built using 2133 2GB addressing, and that PHYSICAL_ALIGN must be at a 2134 minimum of 2MB. As a result, only 10 bits of entropy are 2135 theoretically possible, but the implementations are further 2136 limited due to memory layouts. 2137 2138 If unsure, say Y. 2139 2140# Relocation on x86 needs some additional build support 2141config X86_NEED_RELOCS 2142 def_bool y 2143 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2144 2145config PHYSICAL_ALIGN 2146 hex "Alignment value to which kernel should be aligned" 2147 default "0x200000" 2148 range 0x2000 0x1000000 if X86_32 2149 range 0x200000 0x1000000 if X86_64 2150 ---help--- 2151 This value puts the alignment restrictions on physical address 2152 where kernel is loaded and run from. Kernel is compiled for an 2153 address which meets above alignment restriction. 2154 2155 If bootloader loads the kernel at a non-aligned address and 2156 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2157 address aligned to above value and run from there. 2158 2159 If bootloader loads the kernel at a non-aligned address and 2160 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2161 load address and decompress itself to the address it has been 2162 compiled for and run from there. The address for which kernel is 2163 compiled already meets above alignment restrictions. Hence the 2164 end result is that kernel runs from a physical address meeting 2165 above alignment restrictions. 2166 2167 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2168 this value must be a multiple of 0x200000. 2169 2170 Don't change this unless you know what you are doing. 2171 2172config DYNAMIC_MEMORY_LAYOUT 2173 bool 2174 ---help--- 2175 This option makes base addresses of vmalloc and vmemmap as well as 2176 __PAGE_OFFSET movable during boot. 2177 2178config RANDOMIZE_MEMORY 2179 bool "Randomize the kernel memory sections" 2180 depends on X86_64 2181 depends on RANDOMIZE_BASE 2182 select DYNAMIC_MEMORY_LAYOUT 2183 default RANDOMIZE_BASE 2184 ---help--- 2185 Randomizes the base virtual address of kernel memory sections 2186 (physical memory mapping, vmalloc & vmemmap). This security feature 2187 makes exploits relying on predictable memory locations less reliable. 2188 2189 The order of allocations remains unchanged. Entropy is generated in 2190 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2191 configuration have in average 30,000 different possible virtual 2192 addresses for each memory section. 2193 2194 If unsure, say Y. 2195 2196config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2197 hex "Physical memory mapping padding" if EXPERT 2198 depends on RANDOMIZE_MEMORY 2199 default "0xa" if MEMORY_HOTPLUG 2200 default "0x0" 2201 range 0x1 0x40 if MEMORY_HOTPLUG 2202 range 0x0 0x40 2203 ---help--- 2204 Define the padding in terabytes added to the existing physical 2205 memory size during kernel memory randomization. It is useful 2206 for memory hotplug support but reduces the entropy available for 2207 address randomization. 2208 2209 If unsure, leave at the default value. 2210 2211config HOTPLUG_CPU 2212 bool "Support for hot-pluggable CPUs" 2213 depends on SMP 2214 ---help--- 2215 Say Y here to allow turning CPUs off and on. CPUs can be 2216 controlled through /sys/devices/system/cpu. 2217 ( Note: power management support will enable this option 2218 automatically on SMP systems. ) 2219 Say N if you want to disable CPU hotplug. 2220 2221config BOOTPARAM_HOTPLUG_CPU0 2222 bool "Set default setting of cpu0_hotpluggable" 2223 default n 2224 depends on HOTPLUG_CPU 2225 ---help--- 2226 Set whether default state of cpu0_hotpluggable is on or off. 2227 2228 Say Y here to enable CPU0 hotplug by default. If this switch 2229 is turned on, there is no need to give cpu0_hotplug kernel 2230 parameter and the CPU0 hotplug feature is enabled by default. 2231 2232 Please note: there are two known CPU0 dependencies if you want 2233 to enable the CPU0 hotplug feature either by this switch or by 2234 cpu0_hotplug kernel parameter. 2235 2236 First, resume from hibernate or suspend always starts from CPU0. 2237 So hibernate and suspend are prevented if CPU0 is offline. 2238 2239 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2240 offline if any interrupt can not migrate out of CPU0. There may 2241 be other CPU0 dependencies. 2242 2243 Please make sure the dependencies are under your control before 2244 you enable this feature. 2245 2246 Say N if you don't want to enable CPU0 hotplug feature by default. 2247 You still can enable the CPU0 hotplug feature at boot by kernel 2248 parameter cpu0_hotplug. 2249 2250config DEBUG_HOTPLUG_CPU0 2251 def_bool n 2252 prompt "Debug CPU0 hotplug" 2253 depends on HOTPLUG_CPU 2254 ---help--- 2255 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2256 soon as possible and boots up userspace with CPU0 offlined. User 2257 can online CPU0 back after boot time. 2258 2259 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2260 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2261 compilation or giving cpu0_hotplug kernel parameter at boot. 2262 2263 If unsure, say N. 2264 2265config COMPAT_VDSO 2266 def_bool n 2267 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2268 depends on COMPAT_32 2269 ---help--- 2270 Certain buggy versions of glibc will crash if they are 2271 presented with a 32-bit vDSO that is not mapped at the address 2272 indicated in its segment table. 2273 2274 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2275 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2276 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2277 the only released version with the bug, but OpenSUSE 9 2278 contains a buggy "glibc 2.3.2". 2279 2280 The symptom of the bug is that everything crashes on startup, saying: 2281 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2282 2283 Saying Y here changes the default value of the vdso32 boot 2284 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2285 This works around the glibc bug but hurts performance. 2286 2287 If unsure, say N: if you are compiling your own kernel, you 2288 are unlikely to be using a buggy version of glibc. 2289 2290choice 2291 prompt "vsyscall table for legacy applications" 2292 depends on X86_64 2293 default LEGACY_VSYSCALL_EMULATE 2294 help 2295 Legacy user code that does not know how to find the vDSO expects 2296 to be able to issue three syscalls by calling fixed addresses in 2297 kernel space. Since this location is not randomized with ASLR, 2298 it can be used to assist security vulnerability exploitation. 2299 2300 This setting can be changed at boot time via the kernel command 2301 line parameter vsyscall=[emulate|none]. 2302 2303 On a system with recent enough glibc (2.14 or newer) and no 2304 static binaries, you can say None without a performance penalty 2305 to improve security. 2306 2307 If unsure, select "Emulate". 2308 2309 config LEGACY_VSYSCALL_EMULATE 2310 bool "Emulate" 2311 help 2312 The kernel traps and emulates calls into the fixed 2313 vsyscall address mapping. This makes the mapping 2314 non-executable, but it still contains known contents, 2315 which could be used in certain rare security vulnerability 2316 exploits. This configuration is recommended when userspace 2317 still uses the vsyscall area. 2318 2319 config LEGACY_VSYSCALL_NONE 2320 bool "None" 2321 help 2322 There will be no vsyscall mapping at all. This will 2323 eliminate any risk of ASLR bypass due to the vsyscall 2324 fixed address mapping. Attempts to use the vsyscalls 2325 will be reported to dmesg, so that either old or 2326 malicious userspace programs can be identified. 2327 2328endchoice 2329 2330config CMDLINE_BOOL 2331 bool "Built-in kernel command line" 2332 ---help--- 2333 Allow for specifying boot arguments to the kernel at 2334 build time. On some systems (e.g. embedded ones), it is 2335 necessary or convenient to provide some or all of the 2336 kernel boot arguments with the kernel itself (that is, 2337 to not rely on the boot loader to provide them.) 2338 2339 To compile command line arguments into the kernel, 2340 set this option to 'Y', then fill in the 2341 boot arguments in CONFIG_CMDLINE. 2342 2343 Systems with fully functional boot loaders (i.e. non-embedded) 2344 should leave this option set to 'N'. 2345 2346config CMDLINE 2347 string "Built-in kernel command string" 2348 depends on CMDLINE_BOOL 2349 default "" 2350 ---help--- 2351 Enter arguments here that should be compiled into the kernel 2352 image and used at boot time. If the boot loader provides a 2353 command line at boot time, it is appended to this string to 2354 form the full kernel command line, when the system boots. 2355 2356 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2357 change this behavior. 2358 2359 In most cases, the command line (whether built-in or provided 2360 by the boot loader) should specify the device for the root 2361 file system. 2362 2363config CMDLINE_OVERRIDE 2364 bool "Built-in command line overrides boot loader arguments" 2365 depends on CMDLINE_BOOL 2366 ---help--- 2367 Set this option to 'Y' to have the kernel ignore the boot loader 2368 command line, and use ONLY the built-in command line. 2369 2370 This is used to work around broken boot loaders. This should 2371 be set to 'N' under normal conditions. 2372 2373config MODIFY_LDT_SYSCALL 2374 bool "Enable the LDT (local descriptor table)" if EXPERT 2375 default y 2376 ---help--- 2377 Linux can allow user programs to install a per-process x86 2378 Local Descriptor Table (LDT) using the modify_ldt(2) system 2379 call. This is required to run 16-bit or segmented code such as 2380 DOSEMU or some Wine programs. It is also used by some very old 2381 threading libraries. 2382 2383 Enabling this feature adds a small amount of overhead to 2384 context switches and increases the low-level kernel attack 2385 surface. Disabling it removes the modify_ldt(2) system call. 2386 2387 Saying 'N' here may make sense for embedded or server kernels. 2388 2389source "kernel/livepatch/Kconfig" 2390 2391endmenu 2392 2393config ARCH_HAS_ADD_PAGES 2394 def_bool y 2395 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2396 2397config ARCH_ENABLE_MEMORY_HOTPLUG 2398 def_bool y 2399 depends on X86_64 || (X86_32 && HIGHMEM) 2400 2401config ARCH_ENABLE_MEMORY_HOTREMOVE 2402 def_bool y 2403 depends on MEMORY_HOTPLUG 2404 2405config USE_PERCPU_NUMA_NODE_ID 2406 def_bool y 2407 depends on NUMA 2408 2409config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2410 def_bool y 2411 depends on X86_64 || X86_PAE 2412 2413config ARCH_ENABLE_HUGEPAGE_MIGRATION 2414 def_bool y 2415 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2416 2417config ARCH_ENABLE_THP_MIGRATION 2418 def_bool y 2419 depends on X86_64 && TRANSPARENT_HUGEPAGE 2420 2421menu "Power management and ACPI options" 2422 2423config ARCH_HIBERNATION_HEADER 2424 def_bool y 2425 depends on X86_64 && HIBERNATION 2426 2427source "kernel/power/Kconfig" 2428 2429source "drivers/acpi/Kconfig" 2430 2431source "drivers/sfi/Kconfig" 2432 2433config X86_APM_BOOT 2434 def_bool y 2435 depends on APM 2436 2437menuconfig APM 2438 tristate "APM (Advanced Power Management) BIOS support" 2439 depends on X86_32 && PM_SLEEP 2440 ---help--- 2441 APM is a BIOS specification for saving power using several different 2442 techniques. This is mostly useful for battery powered laptops with 2443 APM compliant BIOSes. If you say Y here, the system time will be 2444 reset after a RESUME operation, the /proc/apm device will provide 2445 battery status information, and user-space programs will receive 2446 notification of APM "events" (e.g. battery status change). 2447 2448 If you select "Y" here, you can disable actual use of the APM 2449 BIOS by passing the "apm=off" option to the kernel at boot time. 2450 2451 Note that the APM support is almost completely disabled for 2452 machines with more than one CPU. 2453 2454 In order to use APM, you will need supporting software. For location 2455 and more information, read <file:Documentation/power/apm-acpi.txt> 2456 and the Battery Powered Linux mini-HOWTO, available from 2457 <http://www.tldp.org/docs.html#howto>. 2458 2459 This driver does not spin down disk drives (see the hdparm(8) 2460 manpage ("man 8 hdparm") for that), and it doesn't turn off 2461 VESA-compliant "green" monitors. 2462 2463 This driver does not support the TI 4000M TravelMate and the ACER 2464 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2465 desktop machines also don't have compliant BIOSes, and this driver 2466 may cause those machines to panic during the boot phase. 2467 2468 Generally, if you don't have a battery in your machine, there isn't 2469 much point in using this driver and you should say N. If you get 2470 random kernel OOPSes or reboots that don't seem to be related to 2471 anything, try disabling/enabling this option (or disabling/enabling 2472 APM in your BIOS). 2473 2474 Some other things you should try when experiencing seemingly random, 2475 "weird" problems: 2476 2477 1) make sure that you have enough swap space and that it is 2478 enabled. 2479 2) pass the "no-hlt" option to the kernel 2480 3) switch on floating point emulation in the kernel and pass 2481 the "no387" option to the kernel 2482 4) pass the "floppy=nodma" option to the kernel 2483 5) pass the "mem=4M" option to the kernel (thereby disabling 2484 all but the first 4 MB of RAM) 2485 6) make sure that the CPU is not over clocked. 2486 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2487 8) disable the cache from your BIOS settings 2488 9) install a fan for the video card or exchange video RAM 2489 10) install a better fan for the CPU 2490 11) exchange RAM chips 2491 12) exchange the motherboard. 2492 2493 To compile this driver as a module, choose M here: the 2494 module will be called apm. 2495 2496if APM 2497 2498config APM_IGNORE_USER_SUSPEND 2499 bool "Ignore USER SUSPEND" 2500 ---help--- 2501 This option will ignore USER SUSPEND requests. On machines with a 2502 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2503 series notebooks, it is necessary to say Y because of a BIOS bug. 2504 2505config APM_DO_ENABLE 2506 bool "Enable PM at boot time" 2507 ---help--- 2508 Enable APM features at boot time. From page 36 of the APM BIOS 2509 specification: "When disabled, the APM BIOS does not automatically 2510 power manage devices, enter the Standby State, enter the Suspend 2511 State, or take power saving steps in response to CPU Idle calls." 2512 This driver will make CPU Idle calls when Linux is idle (unless this 2513 feature is turned off -- see "Do CPU IDLE calls", below). This 2514 should always save battery power, but more complicated APM features 2515 will be dependent on your BIOS implementation. You may need to turn 2516 this option off if your computer hangs at boot time when using APM 2517 support, or if it beeps continuously instead of suspending. Turn 2518 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2519 T400CDT. This is off by default since most machines do fine without 2520 this feature. 2521 2522config APM_CPU_IDLE 2523 depends on CPU_IDLE 2524 bool "Make CPU Idle calls when idle" 2525 ---help--- 2526 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2527 On some machines, this can activate improved power savings, such as 2528 a slowed CPU clock rate, when the machine is idle. These idle calls 2529 are made after the idle loop has run for some length of time (e.g., 2530 333 mS). On some machines, this will cause a hang at boot time or 2531 whenever the CPU becomes idle. (On machines with more than one CPU, 2532 this option does nothing.) 2533 2534config APM_DISPLAY_BLANK 2535 bool "Enable console blanking using APM" 2536 ---help--- 2537 Enable console blanking using the APM. Some laptops can use this to 2538 turn off the LCD backlight when the screen blanker of the Linux 2539 virtual console blanks the screen. Note that this is only used by 2540 the virtual console screen blanker, and won't turn off the backlight 2541 when using the X Window system. This also doesn't have anything to 2542 do with your VESA-compliant power-saving monitor. Further, this 2543 option doesn't work for all laptops -- it might not turn off your 2544 backlight at all, or it might print a lot of errors to the console, 2545 especially if you are using gpm. 2546 2547config APM_ALLOW_INTS 2548 bool "Allow interrupts during APM BIOS calls" 2549 ---help--- 2550 Normally we disable external interrupts while we are making calls to 2551 the APM BIOS as a measure to lessen the effects of a badly behaving 2552 BIOS implementation. The BIOS should reenable interrupts if it 2553 needs to. Unfortunately, some BIOSes do not -- especially those in 2554 many of the newer IBM Thinkpads. If you experience hangs when you 2555 suspend, try setting this to Y. Otherwise, say N. 2556 2557endif # APM 2558 2559source "drivers/cpufreq/Kconfig" 2560 2561source "drivers/cpuidle/Kconfig" 2562 2563source "drivers/idle/Kconfig" 2564 2565endmenu 2566 2567 2568menu "Bus options (PCI etc.)" 2569 2570config PCI 2571 bool "PCI support" 2572 default y 2573 ---help--- 2574 Find out whether you have a PCI motherboard. PCI is the name of a 2575 bus system, i.e. the way the CPU talks to the other stuff inside 2576 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2577 VESA. If you have PCI, say Y, otherwise N. 2578 2579choice 2580 prompt "PCI access mode" 2581 depends on X86_32 && PCI 2582 default PCI_GOANY 2583 ---help--- 2584 On PCI systems, the BIOS can be used to detect the PCI devices and 2585 determine their configuration. However, some old PCI motherboards 2586 have BIOS bugs and may crash if this is done. Also, some embedded 2587 PCI-based systems don't have any BIOS at all. Linux can also try to 2588 detect the PCI hardware directly without using the BIOS. 2589 2590 With this option, you can specify how Linux should detect the 2591 PCI devices. If you choose "BIOS", the BIOS will be used, 2592 if you choose "Direct", the BIOS won't be used, and if you 2593 choose "MMConfig", then PCI Express MMCONFIG will be used. 2594 If you choose "Any", the kernel will try MMCONFIG, then the 2595 direct access method and falls back to the BIOS if that doesn't 2596 work. If unsure, go with the default, which is "Any". 2597 2598config PCI_GOBIOS 2599 bool "BIOS" 2600 2601config PCI_GOMMCONFIG 2602 bool "MMConfig" 2603 2604config PCI_GODIRECT 2605 bool "Direct" 2606 2607config PCI_GOOLPC 2608 bool "OLPC XO-1" 2609 depends on OLPC 2610 2611config PCI_GOANY 2612 bool "Any" 2613 2614endchoice 2615 2616config PCI_BIOS 2617 def_bool y 2618 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2619 2620# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2621config PCI_DIRECT 2622 def_bool y 2623 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2624 2625config PCI_MMCONFIG 2626 bool "Support mmconfig PCI config space access" if X86_64 2627 default y 2628 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2629 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2630 2631config PCI_OLPC 2632 def_bool y 2633 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2634 2635config PCI_XEN 2636 def_bool y 2637 depends on PCI && XEN 2638 select SWIOTLB_XEN 2639 2640config PCI_DOMAINS 2641 def_bool y 2642 depends on PCI 2643 2644config MMCONF_FAM10H 2645 def_bool y 2646 depends on X86_64 && PCI_MMCONFIG && ACPI 2647 2648config PCI_CNB20LE_QUIRK 2649 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2650 depends on PCI 2651 help 2652 Read the PCI windows out of the CNB20LE host bridge. This allows 2653 PCI hotplug to work on systems with the CNB20LE chipset which do 2654 not have ACPI. 2655 2656 There's no public spec for this chipset, and this functionality 2657 is known to be incomplete. 2658 2659 You should say N unless you know you need this. 2660 2661source "drivers/pci/Kconfig" 2662 2663config ISA_BUS 2664 bool "ISA bus support on modern systems" if EXPERT 2665 help 2666 Expose ISA bus device drivers and options available for selection and 2667 configuration. Enable this option if your target machine has an ISA 2668 bus. ISA is an older system, displaced by PCI and newer bus 2669 architectures -- if your target machine is modern, it probably does 2670 not have an ISA bus. 2671 2672 If unsure, say N. 2673 2674# x86_64 have no ISA slots, but can have ISA-style DMA. 2675config ISA_DMA_API 2676 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2677 default y 2678 help 2679 Enables ISA-style DMA support for devices requiring such controllers. 2680 If unsure, say Y. 2681 2682if X86_32 2683 2684config ISA 2685 bool "ISA support" 2686 ---help--- 2687 Find out whether you have ISA slots on your motherboard. ISA is the 2688 name of a bus system, i.e. the way the CPU talks to the other stuff 2689 inside your box. Other bus systems are PCI, EISA, MicroChannel 2690 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2691 newer boards don't support it. If you have ISA, say Y, otherwise N. 2692 2693config EISA 2694 bool "EISA support" 2695 depends on ISA 2696 ---help--- 2697 The Extended Industry Standard Architecture (EISA) bus was 2698 developed as an open alternative to the IBM MicroChannel bus. 2699 2700 The EISA bus provided some of the features of the IBM MicroChannel 2701 bus while maintaining backward compatibility with cards made for 2702 the older ISA bus. The EISA bus saw limited use between 1988 and 2703 1995 when it was made obsolete by the PCI bus. 2704 2705 Say Y here if you are building a kernel for an EISA-based machine. 2706 2707 Otherwise, say N. 2708 2709source "drivers/eisa/Kconfig" 2710 2711config SCx200 2712 tristate "NatSemi SCx200 support" 2713 ---help--- 2714 This provides basic support for National Semiconductor's 2715 (now AMD's) Geode processors. The driver probes for the 2716 PCI-IDs of several on-chip devices, so its a good dependency 2717 for other scx200_* drivers. 2718 2719 If compiled as a module, the driver is named scx200. 2720 2721config SCx200HR_TIMER 2722 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2723 depends on SCx200 2724 default y 2725 ---help--- 2726 This driver provides a clocksource built upon the on-chip 2727 27MHz high-resolution timer. Its also a workaround for 2728 NSC Geode SC-1100's buggy TSC, which loses time when the 2729 processor goes idle (as is done by the scheduler). The 2730 other workaround is idle=poll boot option. 2731 2732config OLPC 2733 bool "One Laptop Per Child support" 2734 depends on !X86_PAE 2735 select GPIOLIB 2736 select OF 2737 select OF_PROMTREE 2738 select IRQ_DOMAIN 2739 ---help--- 2740 Add support for detecting the unique features of the OLPC 2741 XO hardware. 2742 2743config OLPC_XO1_PM 2744 bool "OLPC XO-1 Power Management" 2745 depends on OLPC && MFD_CS5535 && PM_SLEEP 2746 select MFD_CORE 2747 ---help--- 2748 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2749 2750config OLPC_XO1_RTC 2751 bool "OLPC XO-1 Real Time Clock" 2752 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2753 ---help--- 2754 Add support for the XO-1 real time clock, which can be used as a 2755 programmable wakeup source. 2756 2757config OLPC_XO1_SCI 2758 bool "OLPC XO-1 SCI extras" 2759 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2760 depends on INPUT=y 2761 select POWER_SUPPLY 2762 ---help--- 2763 Add support for SCI-based features of the OLPC XO-1 laptop: 2764 - EC-driven system wakeups 2765 - Power button 2766 - Ebook switch 2767 - Lid switch 2768 - AC adapter status updates 2769 - Battery status updates 2770 2771config OLPC_XO15_SCI 2772 bool "OLPC XO-1.5 SCI extras" 2773 depends on OLPC && ACPI 2774 select POWER_SUPPLY 2775 ---help--- 2776 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2777 - EC-driven system wakeups 2778 - AC adapter status updates 2779 - Battery status updates 2780 2781config ALIX 2782 bool "PCEngines ALIX System Support (LED setup)" 2783 select GPIOLIB 2784 ---help--- 2785 This option enables system support for the PCEngines ALIX. 2786 At present this just sets up LEDs for GPIO control on 2787 ALIX2/3/6 boards. However, other system specific setup should 2788 get added here. 2789 2790 Note: You must still enable the drivers for GPIO and LED support 2791 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2792 2793 Note: You have to set alix.force=1 for boards with Award BIOS. 2794 2795config NET5501 2796 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2797 select GPIOLIB 2798 ---help--- 2799 This option enables system support for the Soekris Engineering net5501. 2800 2801config GEOS 2802 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2803 select GPIOLIB 2804 depends on DMI 2805 ---help--- 2806 This option enables system support for the Traverse Technologies GEOS. 2807 2808config TS5500 2809 bool "Technologic Systems TS-5500 platform support" 2810 depends on MELAN 2811 select CHECK_SIGNATURE 2812 select NEW_LEDS 2813 select LEDS_CLASS 2814 ---help--- 2815 This option enables system support for the Technologic Systems TS-5500. 2816 2817endif # X86_32 2818 2819config AMD_NB 2820 def_bool y 2821 depends on CPU_SUP_AMD && PCI 2822 2823source "drivers/pcmcia/Kconfig" 2824 2825config RAPIDIO 2826 tristate "RapidIO support" 2827 depends on PCI 2828 default n 2829 help 2830 If enabled this option will include drivers and the core 2831 infrastructure code to support RapidIO interconnect devices. 2832 2833source "drivers/rapidio/Kconfig" 2834 2835config X86_SYSFB 2836 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2837 help 2838 Firmwares often provide initial graphics framebuffers so the BIOS, 2839 bootloader or kernel can show basic video-output during boot for 2840 user-guidance and debugging. Historically, x86 used the VESA BIOS 2841 Extensions and EFI-framebuffers for this, which are mostly limited 2842 to x86. 2843 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2844 framebuffers so the new generic system-framebuffer drivers can be 2845 used on x86. If the framebuffer is not compatible with the generic 2846 modes, it is advertised as fallback platform framebuffer so legacy 2847 drivers like efifb, vesafb and uvesafb can pick it up. 2848 If this option is not selected, all system framebuffers are always 2849 marked as fallback platform framebuffers as usual. 2850 2851 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2852 not be able to pick up generic system framebuffers if this option 2853 is selected. You are highly encouraged to enable simplefb as 2854 replacement if you select this option. simplefb can correctly deal 2855 with generic system framebuffers. But you should still keep vesafb 2856 and others enabled as fallback if a system framebuffer is 2857 incompatible with simplefb. 2858 2859 If unsure, say Y. 2860 2861endmenu 2862 2863 2864menu "Binary Emulations" 2865 2866config IA32_EMULATION 2867 bool "IA32 Emulation" 2868 depends on X86_64 2869 select ARCH_WANT_OLD_COMPAT_IPC 2870 select BINFMT_ELF 2871 select COMPAT_BINFMT_ELF 2872 select COMPAT_OLD_SIGACTION 2873 ---help--- 2874 Include code to run legacy 32-bit programs under a 2875 64-bit kernel. You should likely turn this on, unless you're 2876 100% sure that you don't have any 32-bit programs left. 2877 2878config IA32_AOUT 2879 tristate "IA32 a.out support" 2880 depends on IA32_EMULATION 2881 ---help--- 2882 Support old a.out binaries in the 32bit emulation. 2883 2884config X86_X32 2885 bool "x32 ABI for 64-bit mode" 2886 depends on X86_64 2887 ---help--- 2888 Include code to run binaries for the x32 native 32-bit ABI 2889 for 64-bit processors. An x32 process gets access to the 2890 full 64-bit register file and wide data path while leaving 2891 pointers at 32 bits for smaller memory footprint. 2892 2893 You will need a recent binutils (2.22 or later) with 2894 elf32_x86_64 support enabled to compile a kernel with this 2895 option set. 2896 2897config COMPAT_32 2898 def_bool y 2899 depends on IA32_EMULATION || X86_32 2900 select HAVE_UID16 2901 select OLD_SIGSUSPEND3 2902 2903config COMPAT 2904 def_bool y 2905 depends on IA32_EMULATION || X86_X32 2906 2907if COMPAT 2908config COMPAT_FOR_U64_ALIGNMENT 2909 def_bool y 2910 2911config SYSVIPC_COMPAT 2912 def_bool y 2913 depends on SYSVIPC 2914endif 2915 2916endmenu 2917 2918 2919config HAVE_ATOMIC_IOMAP 2920 def_bool y 2921 depends on X86_32 2922 2923config X86_DEV_DMA_OPS 2924 bool 2925 depends on X86_64 || STA2X11 2926 2927config X86_DMA_REMAP 2928 bool 2929 depends on STA2X11 2930 2931config HAVE_GENERIC_GUP 2932 def_bool y 2933 2934source "drivers/firmware/Kconfig" 2935 2936source "arch/x86/kvm/Kconfig" 2937