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_ATOMIC_RMW 79 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 80 select ARCH_USE_BUILTIN_BSWAP 81 select ARCH_USE_QUEUED_RWLOCKS 82 select ARCH_USE_QUEUED_SPINLOCKS 83 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 84 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 85 select ARCH_WANTS_THP_SWAP if X86_64 86 select BUILDTIME_EXTABLE_SORT 87 select CLKEVT_I8253 88 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 89 select CLOCKSOURCE_WATCHDOG 90 select DCACHE_WORD_ACCESS 91 select DMA_DIRECT_OPS 92 select EDAC_ATOMIC_SCRUB 93 select EDAC_SUPPORT 94 select GENERIC_CLOCKEVENTS 95 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 96 select GENERIC_CLOCKEVENTS_MIN_ADJUST 97 select GENERIC_CMOS_UPDATE 98 select GENERIC_CPU_AUTOPROBE 99 select GENERIC_CPU_VULNERABILITIES 100 select GENERIC_EARLY_IOREMAP 101 select GENERIC_FIND_FIRST_BIT 102 select GENERIC_IOMAP 103 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 104 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 105 select GENERIC_IRQ_MIGRATION if SMP 106 select GENERIC_IRQ_PROBE 107 select GENERIC_IRQ_RESERVATION_MODE 108 select GENERIC_IRQ_SHOW 109 select GENERIC_PENDING_IRQ if SMP 110 select GENERIC_SMP_IDLE_THREAD 111 select GENERIC_STRNCPY_FROM_USER 112 select GENERIC_STRNLEN_USER 113 select GENERIC_TIME_VSYSCALL 114 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 115 select HAVE_ACPI_APEI if ACPI 116 select HAVE_ACPI_APEI_NMI if ACPI 117 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 118 select HAVE_ARCH_AUDITSYSCALL 119 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 120 select HAVE_ARCH_JUMP_LABEL 121 select HAVE_ARCH_KASAN if X86_64 122 select HAVE_ARCH_KGDB 123 select HAVE_ARCH_MMAP_RND_BITS if MMU 124 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 125 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 126 select HAVE_ARCH_SECCOMP_FILTER 127 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 128 select HAVE_ARCH_TRACEHOOK 129 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 130 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 131 select HAVE_ARCH_VMAP_STACK if X86_64 132 select HAVE_ARCH_WITHIN_STACK_FRAMES 133 select HAVE_CMPXCHG_DOUBLE 134 select HAVE_CMPXCHG_LOCAL 135 select HAVE_CONTEXT_TRACKING if X86_64 136 select HAVE_COPY_THREAD_TLS 137 select HAVE_C_RECORDMCOUNT 138 select HAVE_DEBUG_KMEMLEAK 139 select HAVE_DEBUG_STACKOVERFLOW 140 select HAVE_DMA_CONTIGUOUS 141 select HAVE_DYNAMIC_FTRACE 142 select HAVE_DYNAMIC_FTRACE_WITH_REGS 143 select HAVE_EBPF_JIT 144 select HAVE_EFFICIENT_UNALIGNED_ACCESS 145 select HAVE_EXIT_THREAD 146 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 147 select HAVE_FTRACE_MCOUNT_RECORD 148 select HAVE_FUNCTION_GRAPH_TRACER 149 select HAVE_FUNCTION_TRACER 150 select HAVE_GCC_PLUGINS 151 select HAVE_HW_BREAKPOINT 152 select HAVE_IDE 153 select HAVE_IOREMAP_PROT 154 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 155 select HAVE_IRQ_TIME_ACCOUNTING 156 select HAVE_KERNEL_BZIP2 157 select HAVE_KERNEL_GZIP 158 select HAVE_KERNEL_LZ4 159 select HAVE_KERNEL_LZMA 160 select HAVE_KERNEL_LZO 161 select HAVE_KERNEL_XZ 162 select HAVE_KPROBES 163 select HAVE_KPROBES_ON_FTRACE 164 select HAVE_FUNCTION_ERROR_INJECTION 165 select HAVE_KRETPROBES 166 select HAVE_KVM 167 select HAVE_LIVEPATCH if X86_64 168 select HAVE_MEMBLOCK 169 select HAVE_MEMBLOCK_NODE_MAP 170 select HAVE_MIXED_BREAKPOINTS_REGS 171 select HAVE_MOD_ARCH_SPECIFIC 172 select HAVE_NMI 173 select HAVE_OPROFILE 174 select HAVE_OPTPROBES 175 select HAVE_PCSPKR_PLATFORM 176 select HAVE_PERF_EVENTS 177 select HAVE_PERF_EVENTS_NMI 178 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 179 select HAVE_PERF_REGS 180 select HAVE_PERF_USER_STACK_DUMP 181 select HAVE_RCU_TABLE_FREE 182 select HAVE_REGS_AND_STACK_ACCESS_API 183 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION 184 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 185 select HAVE_STACK_VALIDATION if X86_64 186 select HAVE_RSEQ 187 select HAVE_SYSCALL_TRACEPOINTS 188 select HAVE_UNSTABLE_SCHED_CLOCK 189 select HAVE_USER_RETURN_NOTIFIER 190 select IRQ_FORCED_THREADING 191 select NEED_SG_DMA_LENGTH 192 select PCI_LOCKLESS_CONFIG 193 select PERF_EVENTS 194 select RTC_LIB 195 select RTC_MC146818_LIB 196 select SPARSE_IRQ 197 select SRCU 198 select SYSCTL_EXCEPTION_TRACE 199 select THREAD_INFO_IN_TASK 200 select USER_STACKTRACE_SUPPORT 201 select VIRT_TO_BUS 202 select X86_FEATURE_NAMES if PROC_FS 203 204config INSTRUCTION_DECODER 205 def_bool y 206 depends on KPROBES || PERF_EVENTS || UPROBES 207 208config OUTPUT_FORMAT 209 string 210 default "elf32-i386" if X86_32 211 default "elf64-x86-64" if X86_64 212 213config ARCH_DEFCONFIG 214 string 215 default "arch/x86/configs/i386_defconfig" if X86_32 216 default "arch/x86/configs/x86_64_defconfig" if X86_64 217 218config LOCKDEP_SUPPORT 219 def_bool y 220 221config STACKTRACE_SUPPORT 222 def_bool y 223 224config MMU 225 def_bool y 226 227config ARCH_MMAP_RND_BITS_MIN 228 default 28 if 64BIT 229 default 8 230 231config ARCH_MMAP_RND_BITS_MAX 232 default 32 if 64BIT 233 default 16 234 235config ARCH_MMAP_RND_COMPAT_BITS_MIN 236 default 8 237 238config ARCH_MMAP_RND_COMPAT_BITS_MAX 239 default 16 240 241config SBUS 242 bool 243 244config GENERIC_ISA_DMA 245 def_bool y 246 depends on ISA_DMA_API 247 248config GENERIC_BUG 249 def_bool y 250 depends on BUG 251 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 252 253config GENERIC_BUG_RELATIVE_POINTERS 254 bool 255 256config GENERIC_HWEIGHT 257 def_bool y 258 259config ARCH_MAY_HAVE_PC_FDC 260 def_bool y 261 depends on ISA_DMA_API 262 263config RWSEM_XCHGADD_ALGORITHM 264 def_bool y 265 266config GENERIC_CALIBRATE_DELAY 267 def_bool y 268 269config ARCH_HAS_CPU_RELAX 270 def_bool y 271 272config ARCH_HAS_CACHE_LINE_SIZE 273 def_bool y 274 275config ARCH_HAS_FILTER_PGPROT 276 def_bool y 277 278config HAVE_SETUP_PER_CPU_AREA 279 def_bool y 280 281config NEED_PER_CPU_EMBED_FIRST_CHUNK 282 def_bool y 283 284config NEED_PER_CPU_PAGE_FIRST_CHUNK 285 def_bool y 286 287config ARCH_HIBERNATION_POSSIBLE 288 def_bool y 289 290config ARCH_SUSPEND_POSSIBLE 291 def_bool y 292 293config ARCH_WANT_HUGE_PMD_SHARE 294 def_bool y 295 296config ARCH_WANT_GENERAL_HUGETLB 297 def_bool y 298 299config ZONE_DMA32 300 def_bool y if X86_64 301 302config AUDIT_ARCH 303 def_bool y if X86_64 304 305config ARCH_SUPPORTS_OPTIMIZED_INLINING 306 def_bool y 307 308config ARCH_SUPPORTS_DEBUG_PAGEALLOC 309 def_bool y 310 311config KASAN_SHADOW_OFFSET 312 hex 313 depends on KASAN 314 default 0xdffffc0000000000 315 316config HAVE_INTEL_TXT 317 def_bool y 318 depends on INTEL_IOMMU && ACPI 319 320config X86_32_SMP 321 def_bool y 322 depends on X86_32 && SMP 323 324config X86_64_SMP 325 def_bool y 326 depends on X86_64 && SMP 327 328config X86_32_LAZY_GS 329 def_bool y 330 depends on X86_32 && !STACKPROTECTOR 331 332config ARCH_SUPPORTS_UPROBES 333 def_bool y 334 335config FIX_EARLYCON_MEM 336 def_bool y 337 338config DYNAMIC_PHYSICAL_MASK 339 bool 340 341config PGTABLE_LEVELS 342 int 343 default 5 if X86_5LEVEL 344 default 4 if X86_64 345 default 3 if X86_PAE 346 default 2 347 348source "init/Kconfig" 349 350config CC_HAS_SANE_STACKPROTECTOR 351 bool 352 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 353 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 354 help 355 We have to make sure stack protector is unconditionally disabled if 356 the compiler produces broken code. 357 358source "kernel/Kconfig.freezer" 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 1046source "kernel/Kconfig.preempt" 1047 1048config UP_LATE_INIT 1049 def_bool y 1050 depends on !SMP && X86_LOCAL_APIC 1051 1052config X86_UP_APIC 1053 bool "Local APIC support on uniprocessors" if !PCI_MSI 1054 default PCI_MSI 1055 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1056 ---help--- 1057 A local APIC (Advanced Programmable Interrupt Controller) is an 1058 integrated interrupt controller in the CPU. If you have a single-CPU 1059 system which has a processor with a local APIC, you can say Y here to 1060 enable and use it. If you say Y here even though your machine doesn't 1061 have a local APIC, then the kernel will still run with no slowdown at 1062 all. The local APIC supports CPU-generated self-interrupts (timer, 1063 performance counters), and the NMI watchdog which detects hard 1064 lockups. 1065 1066config X86_UP_IOAPIC 1067 bool "IO-APIC support on uniprocessors" 1068 depends on X86_UP_APIC 1069 ---help--- 1070 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1071 SMP-capable replacement for PC-style interrupt controllers. Most 1072 SMP systems and many recent uniprocessor systems have one. 1073 1074 If you have a single-CPU system with an IO-APIC, you can say Y here 1075 to use it. If you say Y here even though your machine doesn't have 1076 an IO-APIC, then the kernel will still run with no slowdown at all. 1077 1078config X86_LOCAL_APIC 1079 def_bool y 1080 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1081 select IRQ_DOMAIN_HIERARCHY 1082 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1083 1084config X86_IO_APIC 1085 def_bool y 1086 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1087 1088config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1089 bool "Reroute for broken boot IRQs" 1090 depends on X86_IO_APIC 1091 ---help--- 1092 This option enables a workaround that fixes a source of 1093 spurious interrupts. This is recommended when threaded 1094 interrupt handling is used on systems where the generation of 1095 superfluous "boot interrupts" cannot be disabled. 1096 1097 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1098 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1099 kernel does during interrupt handling). On chipsets where this 1100 boot IRQ generation cannot be disabled, this workaround keeps 1101 the original IRQ line masked so that only the equivalent "boot 1102 IRQ" is delivered to the CPUs. The workaround also tells the 1103 kernel to set up the IRQ handler on the boot IRQ line. In this 1104 way only one interrupt is delivered to the kernel. Otherwise 1105 the spurious second interrupt may cause the kernel to bring 1106 down (vital) interrupt lines. 1107 1108 Only affects "broken" chipsets. Interrupt sharing may be 1109 increased on these systems. 1110 1111config X86_MCE 1112 bool "Machine Check / overheating reporting" 1113 select GENERIC_ALLOCATOR 1114 default y 1115 ---help--- 1116 Machine Check support allows the processor to notify the 1117 kernel if it detects a problem (e.g. overheating, data corruption). 1118 The action the kernel takes depends on the severity of the problem, 1119 ranging from warning messages to halting the machine. 1120 1121config X86_MCELOG_LEGACY 1122 bool "Support for deprecated /dev/mcelog character device" 1123 depends on X86_MCE 1124 ---help--- 1125 Enable support for /dev/mcelog which is needed by the old mcelog 1126 userspace logging daemon. Consider switching to the new generation 1127 rasdaemon solution. 1128 1129config X86_MCE_INTEL 1130 def_bool y 1131 prompt "Intel MCE features" 1132 depends on X86_MCE && X86_LOCAL_APIC 1133 ---help--- 1134 Additional support for intel specific MCE features such as 1135 the thermal monitor. 1136 1137config X86_MCE_AMD 1138 def_bool y 1139 prompt "AMD MCE features" 1140 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1141 ---help--- 1142 Additional support for AMD specific MCE features such as 1143 the DRAM Error Threshold. 1144 1145config X86_ANCIENT_MCE 1146 bool "Support for old Pentium 5 / WinChip machine checks" 1147 depends on X86_32 && X86_MCE 1148 ---help--- 1149 Include support for machine check handling on old Pentium 5 or WinChip 1150 systems. These typically need to be enabled explicitly on the command 1151 line. 1152 1153config X86_MCE_THRESHOLD 1154 depends on X86_MCE_AMD || X86_MCE_INTEL 1155 def_bool y 1156 1157config X86_MCE_INJECT 1158 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1159 tristate "Machine check injector support" 1160 ---help--- 1161 Provide support for injecting machine checks for testing purposes. 1162 If you don't know what a machine check is and you don't do kernel 1163 QA it is safe to say n. 1164 1165config X86_THERMAL_VECTOR 1166 def_bool y 1167 depends on X86_MCE_INTEL 1168 1169source "arch/x86/events/Kconfig" 1170 1171config X86_LEGACY_VM86 1172 bool "Legacy VM86 support" 1173 default n 1174 depends on X86_32 1175 ---help--- 1176 This option allows user programs to put the CPU into V8086 1177 mode, which is an 80286-era approximation of 16-bit real mode. 1178 1179 Some very old versions of X and/or vbetool require this option 1180 for user mode setting. Similarly, DOSEMU will use it if 1181 available to accelerate real mode DOS programs. However, any 1182 recent version of DOSEMU, X, or vbetool should be fully 1183 functional even without kernel VM86 support, as they will all 1184 fall back to software emulation. Nevertheless, if you are using 1185 a 16-bit DOS program where 16-bit performance matters, vm86 1186 mode might be faster than emulation and you might want to 1187 enable this option. 1188 1189 Note that any app that works on a 64-bit kernel is unlikely to 1190 need this option, as 64-bit kernels don't, and can't, support 1191 V8086 mode. This option is also unrelated to 16-bit protected 1192 mode and is not needed to run most 16-bit programs under Wine. 1193 1194 Enabling this option increases the complexity of the kernel 1195 and slows down exception handling a tiny bit. 1196 1197 If unsure, say N here. 1198 1199config VM86 1200 bool 1201 default X86_LEGACY_VM86 1202 1203config X86_16BIT 1204 bool "Enable support for 16-bit segments" if EXPERT 1205 default y 1206 depends on MODIFY_LDT_SYSCALL 1207 ---help--- 1208 This option is required by programs like Wine to run 16-bit 1209 protected mode legacy code on x86 processors. Disabling 1210 this option saves about 300 bytes on i386, or around 6K text 1211 plus 16K runtime memory on x86-64, 1212 1213config X86_ESPFIX32 1214 def_bool y 1215 depends on X86_16BIT && X86_32 1216 1217config X86_ESPFIX64 1218 def_bool y 1219 depends on X86_16BIT && X86_64 1220 1221config X86_VSYSCALL_EMULATION 1222 bool "Enable vsyscall emulation" if EXPERT 1223 default y 1224 depends on X86_64 1225 ---help--- 1226 This enables emulation of the legacy vsyscall page. Disabling 1227 it is roughly equivalent to booting with vsyscall=none, except 1228 that it will also disable the helpful warning if a program 1229 tries to use a vsyscall. With this option set to N, offending 1230 programs will just segfault, citing addresses of the form 1231 0xffffffffff600?00. 1232 1233 This option is required by many programs built before 2013, and 1234 care should be used even with newer programs if set to N. 1235 1236 Disabling this option saves about 7K of kernel size and 1237 possibly 4K of additional runtime pagetable memory. 1238 1239config TOSHIBA 1240 tristate "Toshiba Laptop support" 1241 depends on X86_32 1242 ---help--- 1243 This adds a driver to safely access the System Management Mode of 1244 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1245 not work on models with a Phoenix BIOS. The System Management Mode 1246 is used to set the BIOS and power saving options on Toshiba portables. 1247 1248 For information on utilities to make use of this driver see the 1249 Toshiba Linux utilities web site at: 1250 <http://www.buzzard.org.uk/toshiba/>. 1251 1252 Say Y if you intend to run this kernel on a Toshiba portable. 1253 Say N otherwise. 1254 1255config I8K 1256 tristate "Dell i8k legacy laptop support" 1257 select HWMON 1258 select SENSORS_DELL_SMM 1259 ---help--- 1260 This option enables legacy /proc/i8k userspace interface in hwmon 1261 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1262 temperature and allows controlling fan speeds of Dell laptops via 1263 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1264 it reports also power and hotkey status. For fan speed control is 1265 needed userspace package i8kutils. 1266 1267 Say Y if you intend to run this kernel on old Dell laptops or want to 1268 use userspace package i8kutils. 1269 Say N otherwise. 1270 1271config X86_REBOOTFIXUPS 1272 bool "Enable X86 board specific fixups for reboot" 1273 depends on X86_32 1274 ---help--- 1275 This enables chipset and/or board specific fixups to be done 1276 in order to get reboot to work correctly. This is only needed on 1277 some combinations of hardware and BIOS. The symptom, for which 1278 this config is intended, is when reboot ends with a stalled/hung 1279 system. 1280 1281 Currently, the only fixup is for the Geode machines using 1282 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1283 1284 Say Y if you want to enable the fixup. Currently, it's safe to 1285 enable this option even if you don't need it. 1286 Say N otherwise. 1287 1288config MICROCODE 1289 bool "CPU microcode loading support" 1290 default y 1291 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1292 select FW_LOADER 1293 ---help--- 1294 If you say Y here, you will be able to update the microcode on 1295 Intel and AMD processors. The Intel support is for the IA32 family, 1296 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1297 AMD support is for families 0x10 and later. You will obviously need 1298 the actual microcode binary data itself which is not shipped with 1299 the Linux kernel. 1300 1301 The preferred method to load microcode from a detached initrd is described 1302 in Documentation/x86/microcode.txt. For that you need to enable 1303 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1304 initrd for microcode blobs. 1305 1306 In addition, you can build the microcode into the kernel. For that you 1307 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1308 config option. 1309 1310config MICROCODE_INTEL 1311 bool "Intel microcode loading support" 1312 depends on MICROCODE 1313 default MICROCODE 1314 select FW_LOADER 1315 ---help--- 1316 This options enables microcode patch loading support for Intel 1317 processors. 1318 1319 For the current Intel microcode data package go to 1320 <https://downloadcenter.intel.com> and search for 1321 'Linux Processor Microcode Data File'. 1322 1323config MICROCODE_AMD 1324 bool "AMD microcode loading support" 1325 depends on MICROCODE 1326 select FW_LOADER 1327 ---help--- 1328 If you select this option, microcode patch loading support for AMD 1329 processors will be enabled. 1330 1331config MICROCODE_OLD_INTERFACE 1332 def_bool y 1333 depends on MICROCODE 1334 1335config X86_MSR 1336 tristate "/dev/cpu/*/msr - Model-specific register support" 1337 ---help--- 1338 This device gives privileged processes access to the x86 1339 Model-Specific Registers (MSRs). It is a character device with 1340 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1341 MSR accesses are directed to a specific CPU on multi-processor 1342 systems. 1343 1344config X86_CPUID 1345 tristate "/dev/cpu/*/cpuid - CPU information support" 1346 ---help--- 1347 This device gives processes access to the x86 CPUID instruction to 1348 be executed on a specific processor. It is a character device 1349 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1350 /dev/cpu/31/cpuid. 1351 1352choice 1353 prompt "High Memory Support" 1354 default HIGHMEM4G 1355 depends on X86_32 1356 1357config NOHIGHMEM 1358 bool "off" 1359 ---help--- 1360 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1361 However, the address space of 32-bit x86 processors is only 4 1362 Gigabytes large. That means that, if you have a large amount of 1363 physical memory, not all of it can be "permanently mapped" by the 1364 kernel. The physical memory that's not permanently mapped is called 1365 "high memory". 1366 1367 If you are compiling a kernel which will never run on a machine with 1368 more than 1 Gigabyte total physical RAM, answer "off" here (default 1369 choice and suitable for most users). This will result in a "3GB/1GB" 1370 split: 3GB are mapped so that each process sees a 3GB virtual memory 1371 space and the remaining part of the 4GB virtual memory space is used 1372 by the kernel to permanently map as much physical memory as 1373 possible. 1374 1375 If the machine has between 1 and 4 Gigabytes physical RAM, then 1376 answer "4GB" here. 1377 1378 If more than 4 Gigabytes is used then answer "64GB" here. This 1379 selection turns Intel PAE (Physical Address Extension) mode on. 1380 PAE implements 3-level paging on IA32 processors. PAE is fully 1381 supported by Linux, PAE mode is implemented on all recent Intel 1382 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1383 then the kernel will not boot on CPUs that don't support PAE! 1384 1385 The actual amount of total physical memory will either be 1386 auto detected or can be forced by using a kernel command line option 1387 such as "mem=256M". (Try "man bootparam" or see the documentation of 1388 your boot loader (lilo or loadlin) about how to pass options to the 1389 kernel at boot time.) 1390 1391 If unsure, say "off". 1392 1393config HIGHMEM4G 1394 bool "4GB" 1395 ---help--- 1396 Select this if you have a 32-bit processor and between 1 and 4 1397 gigabytes of physical RAM. 1398 1399config HIGHMEM64G 1400 bool "64GB" 1401 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1402 select X86_PAE 1403 ---help--- 1404 Select this if you have a 32-bit processor and more than 4 1405 gigabytes of physical RAM. 1406 1407endchoice 1408 1409choice 1410 prompt "Memory split" if EXPERT 1411 default VMSPLIT_3G 1412 depends on X86_32 1413 ---help--- 1414 Select the desired split between kernel and user memory. 1415 1416 If the address range available to the kernel is less than the 1417 physical memory installed, the remaining memory will be available 1418 as "high memory". Accessing high memory is a little more costly 1419 than low memory, as it needs to be mapped into the kernel first. 1420 Note that increasing the kernel address space limits the range 1421 available to user programs, making the address space there 1422 tighter. Selecting anything other than the default 3G/1G split 1423 will also likely make your kernel incompatible with binary-only 1424 kernel modules. 1425 1426 If you are not absolutely sure what you are doing, leave this 1427 option alone! 1428 1429 config VMSPLIT_3G 1430 bool "3G/1G user/kernel split" 1431 config VMSPLIT_3G_OPT 1432 depends on !X86_PAE 1433 bool "3G/1G user/kernel split (for full 1G low memory)" 1434 config VMSPLIT_2G 1435 bool "2G/2G user/kernel split" 1436 config VMSPLIT_2G_OPT 1437 depends on !X86_PAE 1438 bool "2G/2G user/kernel split (for full 2G low memory)" 1439 config VMSPLIT_1G 1440 bool "1G/3G user/kernel split" 1441endchoice 1442 1443config PAGE_OFFSET 1444 hex 1445 default 0xB0000000 if VMSPLIT_3G_OPT 1446 default 0x80000000 if VMSPLIT_2G 1447 default 0x78000000 if VMSPLIT_2G_OPT 1448 default 0x40000000 if VMSPLIT_1G 1449 default 0xC0000000 1450 depends on X86_32 1451 1452config HIGHMEM 1453 def_bool y 1454 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1455 1456config X86_PAE 1457 bool "PAE (Physical Address Extension) Support" 1458 depends on X86_32 && !HIGHMEM4G 1459 select PHYS_ADDR_T_64BIT 1460 select SWIOTLB 1461 ---help--- 1462 PAE is required for NX support, and furthermore enables 1463 larger swapspace support for non-overcommit purposes. It 1464 has the cost of more pagetable lookup overhead, and also 1465 consumes more pagetable space per process. 1466 1467config X86_5LEVEL 1468 bool "Enable 5-level page tables support" 1469 select DYNAMIC_MEMORY_LAYOUT 1470 select SPARSEMEM_VMEMMAP 1471 depends on X86_64 1472 ---help--- 1473 5-level paging enables access to larger address space: 1474 upto 128 PiB of virtual address space and 4 PiB of 1475 physical address space. 1476 1477 It will be supported by future Intel CPUs. 1478 1479 A kernel with the option enabled can be booted on machines that 1480 support 4- or 5-level paging. 1481 1482 See Documentation/x86/x86_64/5level-paging.txt for more 1483 information. 1484 1485 Say N if unsure. 1486 1487config X86_DIRECT_GBPAGES 1488 def_bool y 1489 depends on X86_64 && !DEBUG_PAGEALLOC 1490 ---help--- 1491 Certain kernel features effectively disable kernel 1492 linear 1 GB mappings (even if the CPU otherwise 1493 supports them), so don't confuse the user by printing 1494 that we have them enabled. 1495 1496config ARCH_HAS_MEM_ENCRYPT 1497 def_bool y 1498 1499config AMD_MEM_ENCRYPT 1500 bool "AMD Secure Memory Encryption (SME) support" 1501 depends on X86_64 && CPU_SUP_AMD 1502 select DYNAMIC_PHYSICAL_MASK 1503 ---help--- 1504 Say yes to enable support for the encryption of system memory. 1505 This requires an AMD processor that supports Secure Memory 1506 Encryption (SME). 1507 1508config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1509 bool "Activate AMD Secure Memory Encryption (SME) by default" 1510 default y 1511 depends on AMD_MEM_ENCRYPT 1512 ---help--- 1513 Say yes to have system memory encrypted by default if running on 1514 an AMD processor that supports Secure Memory Encryption (SME). 1515 1516 If set to Y, then the encryption of system memory can be 1517 deactivated with the mem_encrypt=off command line option. 1518 1519 If set to N, then the encryption of system memory can be 1520 activated with the mem_encrypt=on command line option. 1521 1522config ARCH_USE_MEMREMAP_PROT 1523 def_bool y 1524 depends on AMD_MEM_ENCRYPT 1525 1526# Common NUMA Features 1527config NUMA 1528 bool "Numa Memory Allocation and Scheduler Support" 1529 depends on SMP 1530 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1531 default y if X86_BIGSMP 1532 ---help--- 1533 Enable NUMA (Non Uniform Memory Access) support. 1534 1535 The kernel will try to allocate memory used by a CPU on the 1536 local memory controller of the CPU and add some more 1537 NUMA awareness to the kernel. 1538 1539 For 64-bit this is recommended if the system is Intel Core i7 1540 (or later), AMD Opteron, or EM64T NUMA. 1541 1542 For 32-bit this is only needed if you boot a 32-bit 1543 kernel on a 64-bit NUMA platform. 1544 1545 Otherwise, you should say N. 1546 1547config AMD_NUMA 1548 def_bool y 1549 prompt "Old style AMD Opteron NUMA detection" 1550 depends on X86_64 && NUMA && PCI 1551 ---help--- 1552 Enable AMD NUMA node topology detection. You should say Y here if 1553 you have a multi processor AMD system. This uses an old method to 1554 read the NUMA configuration directly from the builtin Northbridge 1555 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1556 which also takes priority if both are compiled in. 1557 1558config X86_64_ACPI_NUMA 1559 def_bool y 1560 prompt "ACPI NUMA detection" 1561 depends on X86_64 && NUMA && ACPI && PCI 1562 select ACPI_NUMA 1563 ---help--- 1564 Enable ACPI SRAT based node topology detection. 1565 1566# Some NUMA nodes have memory ranges that span 1567# other nodes. Even though a pfn is valid and 1568# between a node's start and end pfns, it may not 1569# reside on that node. See memmap_init_zone() 1570# for details. 1571config NODES_SPAN_OTHER_NODES 1572 def_bool y 1573 depends on X86_64_ACPI_NUMA 1574 1575config NUMA_EMU 1576 bool "NUMA emulation" 1577 depends on NUMA 1578 ---help--- 1579 Enable NUMA emulation. A flat machine will be split 1580 into virtual nodes when booted with "numa=fake=N", where N is the 1581 number of nodes. This is only useful for debugging. 1582 1583config NODES_SHIFT 1584 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1585 range 1 10 1586 default "10" if MAXSMP 1587 default "6" if X86_64 1588 default "3" 1589 depends on NEED_MULTIPLE_NODES 1590 ---help--- 1591 Specify the maximum number of NUMA Nodes available on the target 1592 system. Increases memory reserved to accommodate various tables. 1593 1594config ARCH_HAVE_MEMORY_PRESENT 1595 def_bool y 1596 depends on X86_32 && DISCONTIGMEM 1597 1598config ARCH_FLATMEM_ENABLE 1599 def_bool y 1600 depends on X86_32 && !NUMA 1601 1602config ARCH_DISCONTIGMEM_ENABLE 1603 def_bool y 1604 depends on NUMA && X86_32 1605 1606config ARCH_DISCONTIGMEM_DEFAULT 1607 def_bool y 1608 depends on NUMA && X86_32 1609 1610config ARCH_SPARSEMEM_ENABLE 1611 def_bool y 1612 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1613 select SPARSEMEM_STATIC if X86_32 1614 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1615 1616config ARCH_SPARSEMEM_DEFAULT 1617 def_bool y 1618 depends on X86_64 1619 1620config ARCH_SELECT_MEMORY_MODEL 1621 def_bool y 1622 depends on ARCH_SPARSEMEM_ENABLE 1623 1624config ARCH_MEMORY_PROBE 1625 bool "Enable sysfs memory/probe interface" 1626 depends on X86_64 && MEMORY_HOTPLUG 1627 help 1628 This option enables a sysfs memory/probe interface for testing. 1629 See Documentation/memory-hotplug.txt for more information. 1630 If you are unsure how to answer this question, answer N. 1631 1632config ARCH_PROC_KCORE_TEXT 1633 def_bool y 1634 depends on X86_64 && PROC_KCORE 1635 1636config ILLEGAL_POINTER_VALUE 1637 hex 1638 default 0 if X86_32 1639 default 0xdead000000000000 if X86_64 1640 1641source "mm/Kconfig" 1642 1643config X86_PMEM_LEGACY_DEVICE 1644 bool 1645 1646config X86_PMEM_LEGACY 1647 tristate "Support non-standard NVDIMMs and ADR protected memory" 1648 depends on PHYS_ADDR_T_64BIT 1649 depends on BLK_DEV 1650 select X86_PMEM_LEGACY_DEVICE 1651 select LIBNVDIMM 1652 help 1653 Treat memory marked using the non-standard e820 type of 12 as used 1654 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1655 The kernel will offer these regions to the 'pmem' driver so 1656 they can be used for persistent storage. 1657 1658 Say Y if unsure. 1659 1660config HIGHPTE 1661 bool "Allocate 3rd-level pagetables from highmem" 1662 depends on HIGHMEM 1663 ---help--- 1664 The VM uses one page table entry for each page of physical memory. 1665 For systems with a lot of RAM, this can be wasteful of precious 1666 low memory. Setting this option will put user-space page table 1667 entries in high memory. 1668 1669config X86_CHECK_BIOS_CORRUPTION 1670 bool "Check for low memory corruption" 1671 ---help--- 1672 Periodically check for memory corruption in low memory, which 1673 is suspected to be caused by BIOS. Even when enabled in the 1674 configuration, it is disabled at runtime. Enable it by 1675 setting "memory_corruption_check=1" on the kernel command 1676 line. By default it scans the low 64k of memory every 60 1677 seconds; see the memory_corruption_check_size and 1678 memory_corruption_check_period parameters in 1679 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1680 1681 When enabled with the default parameters, this option has 1682 almost no overhead, as it reserves a relatively small amount 1683 of memory and scans it infrequently. It both detects corruption 1684 and prevents it from affecting the running system. 1685 1686 It is, however, intended as a diagnostic tool; if repeatable 1687 BIOS-originated corruption always affects the same memory, 1688 you can use memmap= to prevent the kernel from using that 1689 memory. 1690 1691config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1692 bool "Set the default setting of memory_corruption_check" 1693 depends on X86_CHECK_BIOS_CORRUPTION 1694 default y 1695 ---help--- 1696 Set whether the default state of memory_corruption_check is 1697 on or off. 1698 1699config X86_RESERVE_LOW 1700 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1701 default 64 1702 range 4 640 1703 ---help--- 1704 Specify the amount of low memory to reserve for the BIOS. 1705 1706 The first page contains BIOS data structures that the kernel 1707 must not use, so that page must always be reserved. 1708 1709 By default we reserve the first 64K of physical RAM, as a 1710 number of BIOSes are known to corrupt that memory range 1711 during events such as suspend/resume or monitor cable 1712 insertion, so it must not be used by the kernel. 1713 1714 You can set this to 4 if you are absolutely sure that you 1715 trust the BIOS to get all its memory reservations and usages 1716 right. If you know your BIOS have problems beyond the 1717 default 64K area, you can set this to 640 to avoid using the 1718 entire low memory range. 1719 1720 If you have doubts about the BIOS (e.g. suspend/resume does 1721 not work or there's kernel crashes after certain hardware 1722 hotplug events) then you might want to enable 1723 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1724 typical corruption patterns. 1725 1726 Leave this to the default value of 64 if you are unsure. 1727 1728config MATH_EMULATION 1729 bool 1730 depends on MODIFY_LDT_SYSCALL 1731 prompt "Math emulation" if X86_32 1732 ---help--- 1733 Linux can emulate a math coprocessor (used for floating point 1734 operations) if you don't have one. 486DX and Pentium processors have 1735 a math coprocessor built in, 486SX and 386 do not, unless you added 1736 a 487DX or 387, respectively. (The messages during boot time can 1737 give you some hints here ["man dmesg"].) Everyone needs either a 1738 coprocessor or this emulation. 1739 1740 If you don't have a math coprocessor, you need to say Y here; if you 1741 say Y here even though you have a coprocessor, the coprocessor will 1742 be used nevertheless. (This behavior can be changed with the kernel 1743 command line option "no387", which comes handy if your coprocessor 1744 is broken. Try "man bootparam" or see the documentation of your boot 1745 loader (lilo or loadlin) about how to pass options to the kernel at 1746 boot time.) This means that it is a good idea to say Y here if you 1747 intend to use this kernel on different machines. 1748 1749 More information about the internals of the Linux math coprocessor 1750 emulation can be found in <file:arch/x86/math-emu/README>. 1751 1752 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1753 kernel, it won't hurt. 1754 1755config MTRR 1756 def_bool y 1757 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1758 ---help--- 1759 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1760 the Memory Type Range Registers (MTRRs) may be used to control 1761 processor access to memory ranges. This is most useful if you have 1762 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1763 allows bus write transfers to be combined into a larger transfer 1764 before bursting over the PCI/AGP bus. This can increase performance 1765 of image write operations 2.5 times or more. Saying Y here creates a 1766 /proc/mtrr file which may be used to manipulate your processor's 1767 MTRRs. Typically the X server should use this. 1768 1769 This code has a reasonably generic interface so that similar 1770 control registers on other processors can be easily supported 1771 as well: 1772 1773 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1774 Registers (ARRs) which provide a similar functionality to MTRRs. For 1775 these, the ARRs are used to emulate the MTRRs. 1776 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1777 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1778 write-combining. All of these processors are supported by this code 1779 and it makes sense to say Y here if you have one of them. 1780 1781 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1782 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1783 can lead to all sorts of problems, so it's good to say Y here. 1784 1785 You can safely say Y even if your machine doesn't have MTRRs, you'll 1786 just add about 9 KB to your kernel. 1787 1788 See <file:Documentation/x86/mtrr.txt> for more information. 1789 1790config MTRR_SANITIZER 1791 def_bool y 1792 prompt "MTRR cleanup support" 1793 depends on MTRR 1794 ---help--- 1795 Convert MTRR layout from continuous to discrete, so X drivers can 1796 add writeback entries. 1797 1798 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1799 The largest mtrr entry size for a continuous block can be set with 1800 mtrr_chunk_size. 1801 1802 If unsure, say Y. 1803 1804config MTRR_SANITIZER_ENABLE_DEFAULT 1805 int "MTRR cleanup enable value (0-1)" 1806 range 0 1 1807 default "0" 1808 depends on MTRR_SANITIZER 1809 ---help--- 1810 Enable mtrr cleanup default value 1811 1812config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1813 int "MTRR cleanup spare reg num (0-7)" 1814 range 0 7 1815 default "1" 1816 depends on MTRR_SANITIZER 1817 ---help--- 1818 mtrr cleanup spare entries default, it can be changed via 1819 mtrr_spare_reg_nr=N on the kernel command line. 1820 1821config X86_PAT 1822 def_bool y 1823 prompt "x86 PAT support" if EXPERT 1824 depends on MTRR 1825 ---help--- 1826 Use PAT attributes to setup page level cache control. 1827 1828 PATs are the modern equivalents of MTRRs and are much more 1829 flexible than MTRRs. 1830 1831 Say N here if you see bootup problems (boot crash, boot hang, 1832 spontaneous reboots) or a non-working video driver. 1833 1834 If unsure, say Y. 1835 1836config ARCH_USES_PG_UNCACHED 1837 def_bool y 1838 depends on X86_PAT 1839 1840config ARCH_RANDOM 1841 def_bool y 1842 prompt "x86 architectural random number generator" if EXPERT 1843 ---help--- 1844 Enable the x86 architectural RDRAND instruction 1845 (Intel Bull Mountain technology) to generate random numbers. 1846 If supported, this is a high bandwidth, cryptographically 1847 secure hardware random number generator. 1848 1849config X86_SMAP 1850 def_bool y 1851 prompt "Supervisor Mode Access Prevention" if EXPERT 1852 ---help--- 1853 Supervisor Mode Access Prevention (SMAP) is a security 1854 feature in newer Intel processors. There is a small 1855 performance cost if this enabled and turned on; there is 1856 also a small increase in the kernel size if this is enabled. 1857 1858 If unsure, say Y. 1859 1860config X86_INTEL_UMIP 1861 def_bool y 1862 depends on CPU_SUP_INTEL 1863 prompt "Intel User Mode Instruction Prevention" if EXPERT 1864 ---help--- 1865 The User Mode Instruction Prevention (UMIP) is a security 1866 feature in newer Intel processors. If enabled, a general 1867 protection fault is issued if the SGDT, SLDT, SIDT, SMSW 1868 or STR instructions are executed in user mode. These instructions 1869 unnecessarily expose information about the hardware state. 1870 1871 The vast majority of applications do not use these instructions. 1872 For the very few that do, software emulation is provided in 1873 specific cases in protected and virtual-8086 modes. Emulated 1874 results are dummy. 1875 1876config X86_INTEL_MPX 1877 prompt "Intel MPX (Memory Protection Extensions)" 1878 def_bool n 1879 # Note: only available in 64-bit mode due to VMA flags shortage 1880 depends on CPU_SUP_INTEL && X86_64 1881 select ARCH_USES_HIGH_VMA_FLAGS 1882 ---help--- 1883 MPX provides hardware features that can be used in 1884 conjunction with compiler-instrumented code to check 1885 memory references. It is designed to detect buffer 1886 overflow or underflow bugs. 1887 1888 This option enables running applications which are 1889 instrumented or otherwise use MPX. It does not use MPX 1890 itself inside the kernel or to protect the kernel 1891 against bad memory references. 1892 1893 Enabling this option will make the kernel larger: 1894 ~8k of kernel text and 36 bytes of data on a 64-bit 1895 defconfig. It adds a long to the 'mm_struct' which 1896 will increase the kernel memory overhead of each 1897 process and adds some branches to paths used during 1898 exec() and munmap(). 1899 1900 For details, see Documentation/x86/intel_mpx.txt 1901 1902 If unsure, say N. 1903 1904config X86_INTEL_MEMORY_PROTECTION_KEYS 1905 prompt "Intel Memory Protection Keys" 1906 def_bool y 1907 # Note: only available in 64-bit mode 1908 depends on CPU_SUP_INTEL && X86_64 1909 select ARCH_USES_HIGH_VMA_FLAGS 1910 select ARCH_HAS_PKEYS 1911 ---help--- 1912 Memory Protection Keys provides a mechanism for enforcing 1913 page-based protections, but without requiring modification of the 1914 page tables when an application changes protection domains. 1915 1916 For details, see Documentation/x86/protection-keys.txt 1917 1918 If unsure, say y. 1919 1920config EFI 1921 bool "EFI runtime service support" 1922 depends on ACPI 1923 select UCS2_STRING 1924 select EFI_RUNTIME_WRAPPERS 1925 ---help--- 1926 This enables the kernel to use EFI runtime services that are 1927 available (such as the EFI variable services). 1928 1929 This option is only useful on systems that have EFI firmware. 1930 In addition, you should use the latest ELILO loader available 1931 at <http://elilo.sourceforge.net> in order to take advantage 1932 of EFI runtime services. However, even with this option, the 1933 resultant kernel should continue to boot on existing non-EFI 1934 platforms. 1935 1936config EFI_STUB 1937 bool "EFI stub support" 1938 depends on EFI && !X86_USE_3DNOW 1939 select RELOCATABLE 1940 ---help--- 1941 This kernel feature allows a bzImage to be loaded directly 1942 by EFI firmware without the use of a bootloader. 1943 1944 See Documentation/efi-stub.txt for more information. 1945 1946config EFI_MIXED 1947 bool "EFI mixed-mode support" 1948 depends on EFI_STUB && X86_64 1949 ---help--- 1950 Enabling this feature allows a 64-bit kernel to be booted 1951 on a 32-bit firmware, provided that your CPU supports 64-bit 1952 mode. 1953 1954 Note that it is not possible to boot a mixed-mode enabled 1955 kernel via the EFI boot stub - a bootloader that supports 1956 the EFI handover protocol must be used. 1957 1958 If unsure, say N. 1959 1960config SECCOMP 1961 def_bool y 1962 prompt "Enable seccomp to safely compute untrusted bytecode" 1963 ---help--- 1964 This kernel feature is useful for number crunching applications 1965 that may need to compute untrusted bytecode during their 1966 execution. By using pipes or other transports made available to 1967 the process as file descriptors supporting the read/write 1968 syscalls, it's possible to isolate those applications in 1969 their own address space using seccomp. Once seccomp is 1970 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1971 and the task is only allowed to execute a few safe syscalls 1972 defined by each seccomp mode. 1973 1974 If unsure, say Y. Only embedded should say N here. 1975 1976source kernel/Kconfig.hz 1977 1978config KEXEC 1979 bool "kexec system call" 1980 select KEXEC_CORE 1981 ---help--- 1982 kexec is a system call that implements the ability to shutdown your 1983 current kernel, and to start another kernel. It is like a reboot 1984 but it is independent of the system firmware. And like a reboot 1985 you can start any kernel with it, not just Linux. 1986 1987 The name comes from the similarity to the exec system call. 1988 1989 It is an ongoing process to be certain the hardware in a machine 1990 is properly shutdown, so do not be surprised if this code does not 1991 initially work for you. As of this writing the exact hardware 1992 interface is strongly in flux, so no good recommendation can be 1993 made. 1994 1995config KEXEC_FILE 1996 bool "kexec file based system call" 1997 select KEXEC_CORE 1998 select BUILD_BIN2C 1999 depends on X86_64 2000 depends on CRYPTO=y 2001 depends on CRYPTO_SHA256=y 2002 ---help--- 2003 This is new version of kexec system call. This system call is 2004 file based and takes file descriptors as system call argument 2005 for kernel and initramfs as opposed to list of segments as 2006 accepted by previous system call. 2007 2008config ARCH_HAS_KEXEC_PURGATORY 2009 def_bool KEXEC_FILE 2010 2011config KEXEC_VERIFY_SIG 2012 bool "Verify kernel signature during kexec_file_load() syscall" 2013 depends on KEXEC_FILE 2014 ---help--- 2015 This option makes kernel signature verification mandatory for 2016 the kexec_file_load() syscall. 2017 2018 In addition to that option, you need to enable signature 2019 verification for the corresponding kernel image type being 2020 loaded in order for this to work. 2021 2022config KEXEC_BZIMAGE_VERIFY_SIG 2023 bool "Enable bzImage signature verification support" 2024 depends on KEXEC_VERIFY_SIG 2025 depends on SIGNED_PE_FILE_VERIFICATION 2026 select SYSTEM_TRUSTED_KEYRING 2027 ---help--- 2028 Enable bzImage signature verification support. 2029 2030config CRASH_DUMP 2031 bool "kernel crash dumps" 2032 depends on X86_64 || (X86_32 && HIGHMEM) 2033 ---help--- 2034 Generate crash dump after being started by kexec. 2035 This should be normally only set in special crash dump kernels 2036 which are loaded in the main kernel with kexec-tools into 2037 a specially reserved region and then later executed after 2038 a crash by kdump/kexec. The crash dump kernel must be compiled 2039 to a memory address not used by the main kernel or BIOS using 2040 PHYSICAL_START, or it must be built as a relocatable image 2041 (CONFIG_RELOCATABLE=y). 2042 For more details see Documentation/kdump/kdump.txt 2043 2044config KEXEC_JUMP 2045 bool "kexec jump" 2046 depends on KEXEC && HIBERNATION 2047 ---help--- 2048 Jump between original kernel and kexeced kernel and invoke 2049 code in physical address mode via KEXEC 2050 2051config PHYSICAL_START 2052 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2053 default "0x1000000" 2054 ---help--- 2055 This gives the physical address where the kernel is loaded. 2056 2057 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2058 bzImage will decompress itself to above physical address and 2059 run from there. Otherwise, bzImage will run from the address where 2060 it has been loaded by the boot loader and will ignore above physical 2061 address. 2062 2063 In normal kdump cases one does not have to set/change this option 2064 as now bzImage can be compiled as a completely relocatable image 2065 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2066 address. This option is mainly useful for the folks who don't want 2067 to use a bzImage for capturing the crash dump and want to use a 2068 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2069 to be specifically compiled to run from a specific memory area 2070 (normally a reserved region) and this option comes handy. 2071 2072 So if you are using bzImage for capturing the crash dump, 2073 leave the value here unchanged to 0x1000000 and set 2074 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2075 for capturing the crash dump change this value to start of 2076 the reserved region. In other words, it can be set based on 2077 the "X" value as specified in the "crashkernel=YM@XM" 2078 command line boot parameter passed to the panic-ed 2079 kernel. Please take a look at Documentation/kdump/kdump.txt 2080 for more details about crash dumps. 2081 2082 Usage of bzImage for capturing the crash dump is recommended as 2083 one does not have to build two kernels. Same kernel can be used 2084 as production kernel and capture kernel. Above option should have 2085 gone away after relocatable bzImage support is introduced. But it 2086 is present because there are users out there who continue to use 2087 vmlinux for dump capture. This option should go away down the 2088 line. 2089 2090 Don't change this unless you know what you are doing. 2091 2092config RELOCATABLE 2093 bool "Build a relocatable kernel" 2094 default y 2095 ---help--- 2096 This builds a kernel image that retains relocation information 2097 so it can be loaded someplace besides the default 1MB. 2098 The relocations tend to make the kernel binary about 10% larger, 2099 but are discarded at runtime. 2100 2101 One use is for the kexec on panic case where the recovery kernel 2102 must live at a different physical address than the primary 2103 kernel. 2104 2105 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2106 it has been loaded at and the compile time physical address 2107 (CONFIG_PHYSICAL_START) is used as the minimum location. 2108 2109config RANDOMIZE_BASE 2110 bool "Randomize the address of the kernel image (KASLR)" 2111 depends on RELOCATABLE 2112 default y 2113 ---help--- 2114 In support of Kernel Address Space Layout Randomization (KASLR), 2115 this randomizes the physical address at which the kernel image 2116 is decompressed and the virtual address where the kernel 2117 image is mapped, as a security feature that deters exploit 2118 attempts relying on knowledge of the location of kernel 2119 code internals. 2120 2121 On 64-bit, the kernel physical and virtual addresses are 2122 randomized separately. The physical address will be anywhere 2123 between 16MB and the top of physical memory (up to 64TB). The 2124 virtual address will be randomized from 16MB up to 1GB (9 bits 2125 of entropy). Note that this also reduces the memory space 2126 available to kernel modules from 1.5GB to 1GB. 2127 2128 On 32-bit, the kernel physical and virtual addresses are 2129 randomized together. They will be randomized from 16MB up to 2130 512MB (8 bits of entropy). 2131 2132 Entropy is generated using the RDRAND instruction if it is 2133 supported. If RDTSC is supported, its value is mixed into 2134 the entropy pool as well. If neither RDRAND nor RDTSC are 2135 supported, then entropy is read from the i8254 timer. The 2136 usable entropy is limited by the kernel being built using 2137 2GB addressing, and that PHYSICAL_ALIGN must be at a 2138 minimum of 2MB. As a result, only 10 bits of entropy are 2139 theoretically possible, but the implementations are further 2140 limited due to memory layouts. 2141 2142 If unsure, say Y. 2143 2144# Relocation on x86 needs some additional build support 2145config X86_NEED_RELOCS 2146 def_bool y 2147 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2148 2149config PHYSICAL_ALIGN 2150 hex "Alignment value to which kernel should be aligned" 2151 default "0x200000" 2152 range 0x2000 0x1000000 if X86_32 2153 range 0x200000 0x1000000 if X86_64 2154 ---help--- 2155 This value puts the alignment restrictions on physical address 2156 where kernel is loaded and run from. Kernel is compiled for an 2157 address which meets above alignment restriction. 2158 2159 If bootloader loads the kernel at a non-aligned address and 2160 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2161 address aligned to above value and run from there. 2162 2163 If bootloader loads the kernel at a non-aligned address and 2164 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2165 load address and decompress itself to the address it has been 2166 compiled for and run from there. The address for which kernel is 2167 compiled already meets above alignment restrictions. Hence the 2168 end result is that kernel runs from a physical address meeting 2169 above alignment restrictions. 2170 2171 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2172 this value must be a multiple of 0x200000. 2173 2174 Don't change this unless you know what you are doing. 2175 2176config DYNAMIC_MEMORY_LAYOUT 2177 bool 2178 ---help--- 2179 This option makes base addresses of vmalloc and vmemmap as well as 2180 __PAGE_OFFSET movable during boot. 2181 2182config RANDOMIZE_MEMORY 2183 bool "Randomize the kernel memory sections" 2184 depends on X86_64 2185 depends on RANDOMIZE_BASE 2186 select DYNAMIC_MEMORY_LAYOUT 2187 default RANDOMIZE_BASE 2188 ---help--- 2189 Randomizes the base virtual address of kernel memory sections 2190 (physical memory mapping, vmalloc & vmemmap). This security feature 2191 makes exploits relying on predictable memory locations less reliable. 2192 2193 The order of allocations remains unchanged. Entropy is generated in 2194 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2195 configuration have in average 30,000 different possible virtual 2196 addresses for each memory section. 2197 2198 If unsure, say Y. 2199 2200config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2201 hex "Physical memory mapping padding" if EXPERT 2202 depends on RANDOMIZE_MEMORY 2203 default "0xa" if MEMORY_HOTPLUG 2204 default "0x0" 2205 range 0x1 0x40 if MEMORY_HOTPLUG 2206 range 0x0 0x40 2207 ---help--- 2208 Define the padding in terabytes added to the existing physical 2209 memory size during kernel memory randomization. It is useful 2210 for memory hotplug support but reduces the entropy available for 2211 address randomization. 2212 2213 If unsure, leave at the default value. 2214 2215config HOTPLUG_CPU 2216 bool "Support for hot-pluggable CPUs" 2217 depends on SMP 2218 ---help--- 2219 Say Y here to allow turning CPUs off and on. CPUs can be 2220 controlled through /sys/devices/system/cpu. 2221 ( Note: power management support will enable this option 2222 automatically on SMP systems. ) 2223 Say N if you want to disable CPU hotplug. 2224 2225config BOOTPARAM_HOTPLUG_CPU0 2226 bool "Set default setting of cpu0_hotpluggable" 2227 default n 2228 depends on HOTPLUG_CPU 2229 ---help--- 2230 Set whether default state of cpu0_hotpluggable is on or off. 2231 2232 Say Y here to enable CPU0 hotplug by default. If this switch 2233 is turned on, there is no need to give cpu0_hotplug kernel 2234 parameter and the CPU0 hotplug feature is enabled by default. 2235 2236 Please note: there are two known CPU0 dependencies if you want 2237 to enable the CPU0 hotplug feature either by this switch or by 2238 cpu0_hotplug kernel parameter. 2239 2240 First, resume from hibernate or suspend always starts from CPU0. 2241 So hibernate and suspend are prevented if CPU0 is offline. 2242 2243 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2244 offline if any interrupt can not migrate out of CPU0. There may 2245 be other CPU0 dependencies. 2246 2247 Please make sure the dependencies are under your control before 2248 you enable this feature. 2249 2250 Say N if you don't want to enable CPU0 hotplug feature by default. 2251 You still can enable the CPU0 hotplug feature at boot by kernel 2252 parameter cpu0_hotplug. 2253 2254config DEBUG_HOTPLUG_CPU0 2255 def_bool n 2256 prompt "Debug CPU0 hotplug" 2257 depends on HOTPLUG_CPU 2258 ---help--- 2259 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2260 soon as possible and boots up userspace with CPU0 offlined. User 2261 can online CPU0 back after boot time. 2262 2263 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2264 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2265 compilation or giving cpu0_hotplug kernel parameter at boot. 2266 2267 If unsure, say N. 2268 2269config COMPAT_VDSO 2270 def_bool n 2271 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2272 depends on COMPAT_32 2273 ---help--- 2274 Certain buggy versions of glibc will crash if they are 2275 presented with a 32-bit vDSO that is not mapped at the address 2276 indicated in its segment table. 2277 2278 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2279 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2280 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2281 the only released version with the bug, but OpenSUSE 9 2282 contains a buggy "glibc 2.3.2". 2283 2284 The symptom of the bug is that everything crashes on startup, saying: 2285 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2286 2287 Saying Y here changes the default value of the vdso32 boot 2288 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2289 This works around the glibc bug but hurts performance. 2290 2291 If unsure, say N: if you are compiling your own kernel, you 2292 are unlikely to be using a buggy version of glibc. 2293 2294choice 2295 prompt "vsyscall table for legacy applications" 2296 depends on X86_64 2297 default LEGACY_VSYSCALL_EMULATE 2298 help 2299 Legacy user code that does not know how to find the vDSO expects 2300 to be able to issue three syscalls by calling fixed addresses in 2301 kernel space. Since this location is not randomized with ASLR, 2302 it can be used to assist security vulnerability exploitation. 2303 2304 This setting can be changed at boot time via the kernel command 2305 line parameter vsyscall=[emulate|none]. 2306 2307 On a system with recent enough glibc (2.14 or newer) and no 2308 static binaries, you can say None without a performance penalty 2309 to improve security. 2310 2311 If unsure, select "Emulate". 2312 2313 config LEGACY_VSYSCALL_EMULATE 2314 bool "Emulate" 2315 help 2316 The kernel traps and emulates calls into the fixed 2317 vsyscall address mapping. This makes the mapping 2318 non-executable, but it still contains known contents, 2319 which could be used in certain rare security vulnerability 2320 exploits. This configuration is recommended when userspace 2321 still uses the vsyscall area. 2322 2323 config LEGACY_VSYSCALL_NONE 2324 bool "None" 2325 help 2326 There will be no vsyscall mapping at all. This will 2327 eliminate any risk of ASLR bypass due to the vsyscall 2328 fixed address mapping. Attempts to use the vsyscalls 2329 will be reported to dmesg, so that either old or 2330 malicious userspace programs can be identified. 2331 2332endchoice 2333 2334config CMDLINE_BOOL 2335 bool "Built-in kernel command line" 2336 ---help--- 2337 Allow for specifying boot arguments to the kernel at 2338 build time. On some systems (e.g. embedded ones), it is 2339 necessary or convenient to provide some or all of the 2340 kernel boot arguments with the kernel itself (that is, 2341 to not rely on the boot loader to provide them.) 2342 2343 To compile command line arguments into the kernel, 2344 set this option to 'Y', then fill in the 2345 boot arguments in CONFIG_CMDLINE. 2346 2347 Systems with fully functional boot loaders (i.e. non-embedded) 2348 should leave this option set to 'N'. 2349 2350config CMDLINE 2351 string "Built-in kernel command string" 2352 depends on CMDLINE_BOOL 2353 default "" 2354 ---help--- 2355 Enter arguments here that should be compiled into the kernel 2356 image and used at boot time. If the boot loader provides a 2357 command line at boot time, it is appended to this string to 2358 form the full kernel command line, when the system boots. 2359 2360 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2361 change this behavior. 2362 2363 In most cases, the command line (whether built-in or provided 2364 by the boot loader) should specify the device for the root 2365 file system. 2366 2367config CMDLINE_OVERRIDE 2368 bool "Built-in command line overrides boot loader arguments" 2369 depends on CMDLINE_BOOL 2370 ---help--- 2371 Set this option to 'Y' to have the kernel ignore the boot loader 2372 command line, and use ONLY the built-in command line. 2373 2374 This is used to work around broken boot loaders. This should 2375 be set to 'N' under normal conditions. 2376 2377config MODIFY_LDT_SYSCALL 2378 bool "Enable the LDT (local descriptor table)" if EXPERT 2379 default y 2380 ---help--- 2381 Linux can allow user programs to install a per-process x86 2382 Local Descriptor Table (LDT) using the modify_ldt(2) system 2383 call. This is required to run 16-bit or segmented code such as 2384 DOSEMU or some Wine programs. It is also used by some very old 2385 threading libraries. 2386 2387 Enabling this feature adds a small amount of overhead to 2388 context switches and increases the low-level kernel attack 2389 surface. Disabling it removes the modify_ldt(2) system call. 2390 2391 Saying 'N' here may make sense for embedded or server kernels. 2392 2393source "kernel/livepatch/Kconfig" 2394 2395endmenu 2396 2397config ARCH_HAS_ADD_PAGES 2398 def_bool y 2399 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2400 2401config ARCH_ENABLE_MEMORY_HOTPLUG 2402 def_bool y 2403 depends on X86_64 || (X86_32 && HIGHMEM) 2404 2405config ARCH_ENABLE_MEMORY_HOTREMOVE 2406 def_bool y 2407 depends on MEMORY_HOTPLUG 2408 2409config USE_PERCPU_NUMA_NODE_ID 2410 def_bool y 2411 depends on NUMA 2412 2413config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2414 def_bool y 2415 depends on X86_64 || X86_PAE 2416 2417config ARCH_ENABLE_HUGEPAGE_MIGRATION 2418 def_bool y 2419 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2420 2421config ARCH_ENABLE_THP_MIGRATION 2422 def_bool y 2423 depends on X86_64 && TRANSPARENT_HUGEPAGE 2424 2425menu "Power management and ACPI options" 2426 2427config ARCH_HIBERNATION_HEADER 2428 def_bool y 2429 depends on X86_64 && HIBERNATION 2430 2431source "kernel/power/Kconfig" 2432 2433source "drivers/acpi/Kconfig" 2434 2435source "drivers/sfi/Kconfig" 2436 2437config X86_APM_BOOT 2438 def_bool y 2439 depends on APM 2440 2441menuconfig APM 2442 tristate "APM (Advanced Power Management) BIOS support" 2443 depends on X86_32 && PM_SLEEP 2444 ---help--- 2445 APM is a BIOS specification for saving power using several different 2446 techniques. This is mostly useful for battery powered laptops with 2447 APM compliant BIOSes. If you say Y here, the system time will be 2448 reset after a RESUME operation, the /proc/apm device will provide 2449 battery status information, and user-space programs will receive 2450 notification of APM "events" (e.g. battery status change). 2451 2452 If you select "Y" here, you can disable actual use of the APM 2453 BIOS by passing the "apm=off" option to the kernel at boot time. 2454 2455 Note that the APM support is almost completely disabled for 2456 machines with more than one CPU. 2457 2458 In order to use APM, you will need supporting software. For location 2459 and more information, read <file:Documentation/power/apm-acpi.txt> 2460 and the Battery Powered Linux mini-HOWTO, available from 2461 <http://www.tldp.org/docs.html#howto>. 2462 2463 This driver does not spin down disk drives (see the hdparm(8) 2464 manpage ("man 8 hdparm") for that), and it doesn't turn off 2465 VESA-compliant "green" monitors. 2466 2467 This driver does not support the TI 4000M TravelMate and the ACER 2468 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2469 desktop machines also don't have compliant BIOSes, and this driver 2470 may cause those machines to panic during the boot phase. 2471 2472 Generally, if you don't have a battery in your machine, there isn't 2473 much point in using this driver and you should say N. If you get 2474 random kernel OOPSes or reboots that don't seem to be related to 2475 anything, try disabling/enabling this option (or disabling/enabling 2476 APM in your BIOS). 2477 2478 Some other things you should try when experiencing seemingly random, 2479 "weird" problems: 2480 2481 1) make sure that you have enough swap space and that it is 2482 enabled. 2483 2) pass the "no-hlt" option to the kernel 2484 3) switch on floating point emulation in the kernel and pass 2485 the "no387" option to the kernel 2486 4) pass the "floppy=nodma" option to the kernel 2487 5) pass the "mem=4M" option to the kernel (thereby disabling 2488 all but the first 4 MB of RAM) 2489 6) make sure that the CPU is not over clocked. 2490 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2491 8) disable the cache from your BIOS settings 2492 9) install a fan for the video card or exchange video RAM 2493 10) install a better fan for the CPU 2494 11) exchange RAM chips 2495 12) exchange the motherboard. 2496 2497 To compile this driver as a module, choose M here: the 2498 module will be called apm. 2499 2500if APM 2501 2502config APM_IGNORE_USER_SUSPEND 2503 bool "Ignore USER SUSPEND" 2504 ---help--- 2505 This option will ignore USER SUSPEND requests. On machines with a 2506 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2507 series notebooks, it is necessary to say Y because of a BIOS bug. 2508 2509config APM_DO_ENABLE 2510 bool "Enable PM at boot time" 2511 ---help--- 2512 Enable APM features at boot time. From page 36 of the APM BIOS 2513 specification: "When disabled, the APM BIOS does not automatically 2514 power manage devices, enter the Standby State, enter the Suspend 2515 State, or take power saving steps in response to CPU Idle calls." 2516 This driver will make CPU Idle calls when Linux is idle (unless this 2517 feature is turned off -- see "Do CPU IDLE calls", below). This 2518 should always save battery power, but more complicated APM features 2519 will be dependent on your BIOS implementation. You may need to turn 2520 this option off if your computer hangs at boot time when using APM 2521 support, or if it beeps continuously instead of suspending. Turn 2522 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2523 T400CDT. This is off by default since most machines do fine without 2524 this feature. 2525 2526config APM_CPU_IDLE 2527 depends on CPU_IDLE 2528 bool "Make CPU Idle calls when idle" 2529 ---help--- 2530 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2531 On some machines, this can activate improved power savings, such as 2532 a slowed CPU clock rate, when the machine is idle. These idle calls 2533 are made after the idle loop has run for some length of time (e.g., 2534 333 mS). On some machines, this will cause a hang at boot time or 2535 whenever the CPU becomes idle. (On machines with more than one CPU, 2536 this option does nothing.) 2537 2538config APM_DISPLAY_BLANK 2539 bool "Enable console blanking using APM" 2540 ---help--- 2541 Enable console blanking using the APM. Some laptops can use this to 2542 turn off the LCD backlight when the screen blanker of the Linux 2543 virtual console blanks the screen. Note that this is only used by 2544 the virtual console screen blanker, and won't turn off the backlight 2545 when using the X Window system. This also doesn't have anything to 2546 do with your VESA-compliant power-saving monitor. Further, this 2547 option doesn't work for all laptops -- it might not turn off your 2548 backlight at all, or it might print a lot of errors to the console, 2549 especially if you are using gpm. 2550 2551config APM_ALLOW_INTS 2552 bool "Allow interrupts during APM BIOS calls" 2553 ---help--- 2554 Normally we disable external interrupts while we are making calls to 2555 the APM BIOS as a measure to lessen the effects of a badly behaving 2556 BIOS implementation. The BIOS should reenable interrupts if it 2557 needs to. Unfortunately, some BIOSes do not -- especially those in 2558 many of the newer IBM Thinkpads. If you experience hangs when you 2559 suspend, try setting this to Y. Otherwise, say N. 2560 2561endif # APM 2562 2563source "drivers/cpufreq/Kconfig" 2564 2565source "drivers/cpuidle/Kconfig" 2566 2567source "drivers/idle/Kconfig" 2568 2569endmenu 2570 2571 2572menu "Bus options (PCI etc.)" 2573 2574config PCI 2575 bool "PCI support" 2576 default y 2577 ---help--- 2578 Find out whether you have a PCI motherboard. PCI is the name of a 2579 bus system, i.e. the way the CPU talks to the other stuff inside 2580 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2581 VESA. If you have PCI, say Y, otherwise N. 2582 2583choice 2584 prompt "PCI access mode" 2585 depends on X86_32 && PCI 2586 default PCI_GOANY 2587 ---help--- 2588 On PCI systems, the BIOS can be used to detect the PCI devices and 2589 determine their configuration. However, some old PCI motherboards 2590 have BIOS bugs and may crash if this is done. Also, some embedded 2591 PCI-based systems don't have any BIOS at all. Linux can also try to 2592 detect the PCI hardware directly without using the BIOS. 2593 2594 With this option, you can specify how Linux should detect the 2595 PCI devices. If you choose "BIOS", the BIOS will be used, 2596 if you choose "Direct", the BIOS won't be used, and if you 2597 choose "MMConfig", then PCI Express MMCONFIG will be used. 2598 If you choose "Any", the kernel will try MMCONFIG, then the 2599 direct access method and falls back to the BIOS if that doesn't 2600 work. If unsure, go with the default, which is "Any". 2601 2602config PCI_GOBIOS 2603 bool "BIOS" 2604 2605config PCI_GOMMCONFIG 2606 bool "MMConfig" 2607 2608config PCI_GODIRECT 2609 bool "Direct" 2610 2611config PCI_GOOLPC 2612 bool "OLPC XO-1" 2613 depends on OLPC 2614 2615config PCI_GOANY 2616 bool "Any" 2617 2618endchoice 2619 2620config PCI_BIOS 2621 def_bool y 2622 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2623 2624# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2625config PCI_DIRECT 2626 def_bool y 2627 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2628 2629config PCI_MMCONFIG 2630 bool "Support mmconfig PCI config space access" if X86_64 2631 default y 2632 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) 2633 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2634 2635config PCI_OLPC 2636 def_bool y 2637 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2638 2639config PCI_XEN 2640 def_bool y 2641 depends on PCI && XEN 2642 select SWIOTLB_XEN 2643 2644config PCI_DOMAINS 2645 def_bool y 2646 depends on PCI 2647 2648config MMCONF_FAM10H 2649 def_bool y 2650 depends on X86_64 && PCI_MMCONFIG && ACPI 2651 2652config PCI_CNB20LE_QUIRK 2653 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2654 depends on PCI 2655 help 2656 Read the PCI windows out of the CNB20LE host bridge. This allows 2657 PCI hotplug to work on systems with the CNB20LE chipset which do 2658 not have ACPI. 2659 2660 There's no public spec for this chipset, and this functionality 2661 is known to be incomplete. 2662 2663 You should say N unless you know you need this. 2664 2665source "drivers/pci/Kconfig" 2666 2667config ISA_BUS 2668 bool "ISA bus support on modern systems" if EXPERT 2669 help 2670 Expose ISA bus device drivers and options available for selection and 2671 configuration. Enable this option if your target machine has an ISA 2672 bus. ISA is an older system, displaced by PCI and newer bus 2673 architectures -- if your target machine is modern, it probably does 2674 not have an ISA bus. 2675 2676 If unsure, say N. 2677 2678# x86_64 have no ISA slots, but can have ISA-style DMA. 2679config ISA_DMA_API 2680 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2681 default y 2682 help 2683 Enables ISA-style DMA support for devices requiring such controllers. 2684 If unsure, say Y. 2685 2686if X86_32 2687 2688config ISA 2689 bool "ISA support" 2690 ---help--- 2691 Find out whether you have ISA slots on your motherboard. ISA is the 2692 name of a bus system, i.e. the way the CPU talks to the other stuff 2693 inside your box. Other bus systems are PCI, EISA, MicroChannel 2694 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2695 newer boards don't support it. If you have ISA, say Y, otherwise N. 2696 2697config EISA 2698 bool "EISA support" 2699 depends on ISA 2700 ---help--- 2701 The Extended Industry Standard Architecture (EISA) bus was 2702 developed as an open alternative to the IBM MicroChannel bus. 2703 2704 The EISA bus provided some of the features of the IBM MicroChannel 2705 bus while maintaining backward compatibility with cards made for 2706 the older ISA bus. The EISA bus saw limited use between 1988 and 2707 1995 when it was made obsolete by the PCI bus. 2708 2709 Say Y here if you are building a kernel for an EISA-based machine. 2710 2711 Otherwise, say N. 2712 2713source "drivers/eisa/Kconfig" 2714 2715config SCx200 2716 tristate "NatSemi SCx200 support" 2717 ---help--- 2718 This provides basic support for National Semiconductor's 2719 (now AMD's) Geode processors. The driver probes for the 2720 PCI-IDs of several on-chip devices, so its a good dependency 2721 for other scx200_* drivers. 2722 2723 If compiled as a module, the driver is named scx200. 2724 2725config SCx200HR_TIMER 2726 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2727 depends on SCx200 2728 default y 2729 ---help--- 2730 This driver provides a clocksource built upon the on-chip 2731 27MHz high-resolution timer. Its also a workaround for 2732 NSC Geode SC-1100's buggy TSC, which loses time when the 2733 processor goes idle (as is done by the scheduler). The 2734 other workaround is idle=poll boot option. 2735 2736config OLPC 2737 bool "One Laptop Per Child support" 2738 depends on !X86_PAE 2739 select GPIOLIB 2740 select OF 2741 select OF_PROMTREE 2742 select IRQ_DOMAIN 2743 ---help--- 2744 Add support for detecting the unique features of the OLPC 2745 XO hardware. 2746 2747config OLPC_XO1_PM 2748 bool "OLPC XO-1 Power Management" 2749 depends on OLPC && MFD_CS5535 && PM_SLEEP 2750 select MFD_CORE 2751 ---help--- 2752 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2753 2754config OLPC_XO1_RTC 2755 bool "OLPC XO-1 Real Time Clock" 2756 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2757 ---help--- 2758 Add support for the XO-1 real time clock, which can be used as a 2759 programmable wakeup source. 2760 2761config OLPC_XO1_SCI 2762 bool "OLPC XO-1 SCI extras" 2763 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2764 depends on INPUT=y 2765 select POWER_SUPPLY 2766 ---help--- 2767 Add support for SCI-based features of the OLPC XO-1 laptop: 2768 - EC-driven system wakeups 2769 - Power button 2770 - Ebook switch 2771 - Lid switch 2772 - AC adapter status updates 2773 - Battery status updates 2774 2775config OLPC_XO15_SCI 2776 bool "OLPC XO-1.5 SCI extras" 2777 depends on OLPC && ACPI 2778 select POWER_SUPPLY 2779 ---help--- 2780 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2781 - EC-driven system wakeups 2782 - AC adapter status updates 2783 - Battery status updates 2784 2785config ALIX 2786 bool "PCEngines ALIX System Support (LED setup)" 2787 select GPIOLIB 2788 ---help--- 2789 This option enables system support for the PCEngines ALIX. 2790 At present this just sets up LEDs for GPIO control on 2791 ALIX2/3/6 boards. However, other system specific setup should 2792 get added here. 2793 2794 Note: You must still enable the drivers for GPIO and LED support 2795 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2796 2797 Note: You have to set alix.force=1 for boards with Award BIOS. 2798 2799config NET5501 2800 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2801 select GPIOLIB 2802 ---help--- 2803 This option enables system support for the Soekris Engineering net5501. 2804 2805config GEOS 2806 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2807 select GPIOLIB 2808 depends on DMI 2809 ---help--- 2810 This option enables system support for the Traverse Technologies GEOS. 2811 2812config TS5500 2813 bool "Technologic Systems TS-5500 platform support" 2814 depends on MELAN 2815 select CHECK_SIGNATURE 2816 select NEW_LEDS 2817 select LEDS_CLASS 2818 ---help--- 2819 This option enables system support for the Technologic Systems TS-5500. 2820 2821endif # X86_32 2822 2823config AMD_NB 2824 def_bool y 2825 depends on CPU_SUP_AMD && PCI 2826 2827source "drivers/pcmcia/Kconfig" 2828 2829config RAPIDIO 2830 tristate "RapidIO support" 2831 depends on PCI 2832 default n 2833 help 2834 If enabled this option will include drivers and the core 2835 infrastructure code to support RapidIO interconnect devices. 2836 2837source "drivers/rapidio/Kconfig" 2838 2839config X86_SYSFB 2840 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2841 help 2842 Firmwares often provide initial graphics framebuffers so the BIOS, 2843 bootloader or kernel can show basic video-output during boot for 2844 user-guidance and debugging. Historically, x86 used the VESA BIOS 2845 Extensions and EFI-framebuffers for this, which are mostly limited 2846 to x86. 2847 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2848 framebuffers so the new generic system-framebuffer drivers can be 2849 used on x86. If the framebuffer is not compatible with the generic 2850 modes, it is adverticed as fallback platform framebuffer so legacy 2851 drivers like efifb, vesafb and uvesafb can pick it up. 2852 If this option is not selected, all system framebuffers are always 2853 marked as fallback platform framebuffers as usual. 2854 2855 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2856 not be able to pick up generic system framebuffers if this option 2857 is selected. You are highly encouraged to enable simplefb as 2858 replacement if you select this option. simplefb can correctly deal 2859 with generic system framebuffers. But you should still keep vesafb 2860 and others enabled as fallback if a system framebuffer is 2861 incompatible with simplefb. 2862 2863 If unsure, say Y. 2864 2865endmenu 2866 2867 2868menu "Executable file formats / Emulations" 2869 2870source "fs/Kconfig.binfmt" 2871 2872config IA32_EMULATION 2873 bool "IA32 Emulation" 2874 depends on X86_64 2875 select ARCH_WANT_OLD_COMPAT_IPC 2876 select BINFMT_ELF 2877 select COMPAT_BINFMT_ELF 2878 select COMPAT_OLD_SIGACTION 2879 ---help--- 2880 Include code to run legacy 32-bit programs under a 2881 64-bit kernel. You should likely turn this on, unless you're 2882 100% sure that you don't have any 32-bit programs left. 2883 2884config IA32_AOUT 2885 tristate "IA32 a.out support" 2886 depends on IA32_EMULATION 2887 ---help--- 2888 Support old a.out binaries in the 32bit emulation. 2889 2890config X86_X32 2891 bool "x32 ABI for 64-bit mode" 2892 depends on X86_64 2893 ---help--- 2894 Include code to run binaries for the x32 native 32-bit ABI 2895 for 64-bit processors. An x32 process gets access to the 2896 full 64-bit register file and wide data path while leaving 2897 pointers at 32 bits for smaller memory footprint. 2898 2899 You will need a recent binutils (2.22 or later) with 2900 elf32_x86_64 support enabled to compile a kernel with this 2901 option set. 2902 2903config COMPAT_32 2904 def_bool y 2905 depends on IA32_EMULATION || X86_32 2906 select HAVE_UID16 2907 select OLD_SIGSUSPEND3 2908 2909config COMPAT 2910 def_bool y 2911 depends on IA32_EMULATION || X86_X32 2912 2913if COMPAT 2914config COMPAT_FOR_U64_ALIGNMENT 2915 def_bool y 2916 2917config SYSVIPC_COMPAT 2918 def_bool y 2919 depends on SYSVIPC 2920endif 2921 2922endmenu 2923 2924 2925config HAVE_ATOMIC_IOMAP 2926 def_bool y 2927 depends on X86_32 2928 2929config X86_DEV_DMA_OPS 2930 bool 2931 depends on X86_64 || STA2X11 2932 2933config X86_DMA_REMAP 2934 bool 2935 depends on STA2X11 2936 2937config HAVE_GENERIC_GUP 2938 def_bool y 2939 2940source "net/Kconfig" 2941 2942source "drivers/Kconfig" 2943 2944source "drivers/firmware/Kconfig" 2945 2946source "fs/Kconfig" 2947 2948source "arch/x86/Kconfig.debug" 2949 2950source "security/Kconfig" 2951 2952source "crypto/Kconfig" 2953 2954source "arch/x86/kvm/Kconfig" 2955 2956source "lib/Kconfig" 2957