1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH != "i386" 5 ---help--- 6 Say yes to build a 64-bit kernel - formerly known as x86_64 7 Say no to build a 32-bit kernel - formerly known as i386 8 9config X86_32 10 def_bool y 11 depends on !64BIT 12 # Options that are inherently 32-bit kernel only: 13 select ARCH_WANT_IPC_PARSE_VERSION 14 select CLKSRC_I8253 15 select CLONE_BACKWARDS 16 select HAVE_AOUT 17 select HAVE_GENERIC_DMA_COHERENT 18 select MODULES_USE_ELF_REL 19 select OLD_SIGACTION 20 21config X86_64 22 def_bool y 23 depends on 64BIT 24 # Options that are inherently 64-bit kernel only: 25 select ARCH_HAS_GIGANTIC_PAGE 26 select ARCH_SUPPORTS_INT128 27 select ARCH_USE_CMPXCHG_LOCKREF 28 select HAVE_ARCH_SOFT_DIRTY 29 select MODULES_USE_ELF_RELA 30 select X86_DEV_DMA_OPS 31 32# 33# Arch settings 34# 35# ( Note that options that are marked 'if X86_64' could in principle be 36# ported to 32-bit as well. ) 37# 38config X86 39 def_bool y 40 # 41 # Note: keep this list sorted alphabetically 42 # 43 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 44 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 45 select ANON_INODES 46 select ARCH_CLOCKSOURCE_DATA 47 select ARCH_DISCARD_MEMBLOCK 48 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 49 select ARCH_HAS_DEBUG_VIRTUAL 50 select ARCH_HAS_DEVMEM_IS_ALLOWED 51 select ARCH_HAS_ELF_RANDOMIZE 52 select ARCH_HAS_FAST_MULTIPLIER 53 select ARCH_HAS_GCOV_PROFILE_ALL 54 select ARCH_HAS_KCOV if X86_64 55 select ARCH_HAS_MMIO_FLUSH 56 select ARCH_HAS_PMEM_API if X86_64 57 select ARCH_HAS_SET_MEMORY 58 select ARCH_HAS_SG_CHAIN 59 select ARCH_HAS_STRICT_KERNEL_RWX 60 select ARCH_HAS_STRICT_MODULE_RWX 61 select ARCH_HAS_UBSAN_SANITIZE_ALL 62 select ARCH_HAVE_NMI_SAFE_CMPXCHG 63 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 64 select ARCH_MIGHT_HAVE_PC_PARPORT 65 select ARCH_MIGHT_HAVE_PC_SERIO 66 select ARCH_SUPPORTS_ATOMIC_RMW 67 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 68 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 69 select ARCH_USE_BUILTIN_BSWAP 70 select ARCH_USE_QUEUED_RWLOCKS 71 select ARCH_USE_QUEUED_SPINLOCKS 72 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 73 select ARCH_WANT_FRAME_POINTERS 74 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 75 select BUILDTIME_EXTABLE_SORT 76 select CLKEVT_I8253 77 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 78 select CLOCKSOURCE_WATCHDOG 79 select DCACHE_WORD_ACCESS 80 select EDAC_ATOMIC_SCRUB 81 select EDAC_SUPPORT 82 select GENERIC_CLOCKEVENTS 83 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 84 select GENERIC_CLOCKEVENTS_MIN_ADJUST 85 select GENERIC_CMOS_UPDATE 86 select GENERIC_CPU_AUTOPROBE 87 select GENERIC_EARLY_IOREMAP 88 select GENERIC_FIND_FIRST_BIT 89 select GENERIC_IOMAP 90 select GENERIC_IRQ_PROBE 91 select GENERIC_IRQ_SHOW 92 select GENERIC_PENDING_IRQ if SMP 93 select GENERIC_SMP_IDLE_THREAD 94 select GENERIC_STRNCPY_FROM_USER 95 select GENERIC_STRNLEN_USER 96 select GENERIC_TIME_VSYSCALL 97 select HAVE_ACPI_APEI if ACPI 98 select HAVE_ACPI_APEI_NMI if ACPI 99 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 100 select HAVE_ARCH_AUDITSYSCALL 101 select HAVE_ARCH_HARDENED_USERCOPY 102 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 103 select HAVE_ARCH_JUMP_LABEL 104 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 105 select HAVE_ARCH_KGDB 106 select HAVE_ARCH_KMEMCHECK 107 select HAVE_ARCH_MMAP_RND_BITS if MMU 108 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 109 select HAVE_ARCH_SECCOMP_FILTER 110 select HAVE_ARCH_TRACEHOOK 111 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 112 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 113 select HAVE_ARCH_VMAP_STACK if X86_64 114 select HAVE_ARCH_WITHIN_STACK_FRAMES 115 select HAVE_CC_STACKPROTECTOR 116 select HAVE_CMPXCHG_DOUBLE 117 select HAVE_CMPXCHG_LOCAL 118 select HAVE_CONTEXT_TRACKING if X86_64 119 select HAVE_COPY_THREAD_TLS 120 select HAVE_C_RECORDMCOUNT 121 select HAVE_DEBUG_KMEMLEAK 122 select HAVE_DEBUG_STACKOVERFLOW 123 select HAVE_DMA_API_DEBUG 124 select HAVE_DMA_CONTIGUOUS 125 select HAVE_DYNAMIC_FTRACE 126 select HAVE_DYNAMIC_FTRACE_WITH_REGS 127 select HAVE_EBPF_JIT if X86_64 128 select HAVE_EFFICIENT_UNALIGNED_ACCESS 129 select HAVE_EXIT_THREAD 130 select HAVE_FENTRY if X86_64 131 select HAVE_FTRACE_MCOUNT_RECORD 132 select HAVE_FUNCTION_GRAPH_TRACER 133 select HAVE_FUNCTION_TRACER 134 select HAVE_GCC_PLUGINS 135 select HAVE_HW_BREAKPOINT 136 select HAVE_IDE 137 select HAVE_IOREMAP_PROT 138 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 139 select HAVE_IRQ_TIME_ACCOUNTING 140 select HAVE_KERNEL_BZIP2 141 select HAVE_KERNEL_GZIP 142 select HAVE_KERNEL_LZ4 143 select HAVE_KERNEL_LZMA 144 select HAVE_KERNEL_LZO 145 select HAVE_KERNEL_XZ 146 select HAVE_KPROBES 147 select HAVE_KPROBES_ON_FTRACE 148 select HAVE_KRETPROBES 149 select HAVE_KVM 150 select HAVE_LIVEPATCH if X86_64 151 select HAVE_MEMBLOCK 152 select HAVE_MEMBLOCK_NODE_MAP 153 select HAVE_MIXED_BREAKPOINTS_REGS 154 select HAVE_NMI 155 select HAVE_OPROFILE 156 select HAVE_OPTPROBES 157 select HAVE_PCSPKR_PLATFORM 158 select HAVE_PERF_EVENTS 159 select HAVE_PERF_EVENTS_NMI 160 select HAVE_PERF_REGS 161 select HAVE_PERF_USER_STACK_DUMP 162 select HAVE_REGS_AND_STACK_ACCESS_API 163 select HAVE_RELIABLE_STACKTRACE if X86_64 && FRAME_POINTER && STACK_VALIDATION 164 select HAVE_STACK_VALIDATION if X86_64 165 select HAVE_SYSCALL_TRACEPOINTS 166 select HAVE_UNSTABLE_SCHED_CLOCK 167 select HAVE_USER_RETURN_NOTIFIER 168 select IRQ_FORCED_THREADING 169 select PERF_EVENTS 170 select RTC_LIB 171 select RTC_MC146818_LIB 172 select SPARSE_IRQ 173 select SRCU 174 select SYSCTL_EXCEPTION_TRACE 175 select THREAD_INFO_IN_TASK 176 select USER_STACKTRACE_SUPPORT 177 select VIRT_TO_BUS 178 select X86_FEATURE_NAMES if PROC_FS 179 180config INSTRUCTION_DECODER 181 def_bool y 182 depends on KPROBES || PERF_EVENTS || UPROBES 183 184config OUTPUT_FORMAT 185 string 186 default "elf32-i386" if X86_32 187 default "elf64-x86-64" if X86_64 188 189config ARCH_DEFCONFIG 190 string 191 default "arch/x86/configs/i386_defconfig" if X86_32 192 default "arch/x86/configs/x86_64_defconfig" if X86_64 193 194config LOCKDEP_SUPPORT 195 def_bool y 196 197config STACKTRACE_SUPPORT 198 def_bool y 199 200config MMU 201 def_bool y 202 203config ARCH_MMAP_RND_BITS_MIN 204 default 28 if 64BIT 205 default 8 206 207config ARCH_MMAP_RND_BITS_MAX 208 default 32 if 64BIT 209 default 16 210 211config ARCH_MMAP_RND_COMPAT_BITS_MIN 212 default 8 213 214config ARCH_MMAP_RND_COMPAT_BITS_MAX 215 default 16 216 217config SBUS 218 bool 219 220config NEED_DMA_MAP_STATE 221 def_bool y 222 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 223 224config NEED_SG_DMA_LENGTH 225 def_bool y 226 227config GENERIC_ISA_DMA 228 def_bool y 229 depends on ISA_DMA_API 230 231config GENERIC_BUG 232 def_bool y 233 depends on BUG 234 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 235 236config GENERIC_BUG_RELATIVE_POINTERS 237 bool 238 239config GENERIC_HWEIGHT 240 def_bool y 241 242config ARCH_MAY_HAVE_PC_FDC 243 def_bool y 244 depends on ISA_DMA_API 245 246config RWSEM_XCHGADD_ALGORITHM 247 def_bool y 248 249config GENERIC_CALIBRATE_DELAY 250 def_bool y 251 252config ARCH_HAS_CPU_RELAX 253 def_bool y 254 255config ARCH_HAS_CACHE_LINE_SIZE 256 def_bool y 257 258config HAVE_SETUP_PER_CPU_AREA 259 def_bool y 260 261config NEED_PER_CPU_EMBED_FIRST_CHUNK 262 def_bool y 263 264config NEED_PER_CPU_PAGE_FIRST_CHUNK 265 def_bool y 266 267config ARCH_HIBERNATION_POSSIBLE 268 def_bool y 269 270config ARCH_SUSPEND_POSSIBLE 271 def_bool y 272 273config ARCH_WANT_HUGE_PMD_SHARE 274 def_bool y 275 276config ARCH_WANT_GENERAL_HUGETLB 277 def_bool y 278 279config ZONE_DMA32 280 def_bool y if X86_64 281 282config AUDIT_ARCH 283 def_bool y if X86_64 284 285config ARCH_SUPPORTS_OPTIMIZED_INLINING 286 def_bool y 287 288config ARCH_SUPPORTS_DEBUG_PAGEALLOC 289 def_bool y 290 291config KASAN_SHADOW_OFFSET 292 hex 293 depends on KASAN 294 default 0xdffffc0000000000 295 296config HAVE_INTEL_TXT 297 def_bool y 298 depends on INTEL_IOMMU && ACPI 299 300config X86_32_SMP 301 def_bool y 302 depends on X86_32 && SMP 303 304config X86_64_SMP 305 def_bool y 306 depends on X86_64 && SMP 307 308config X86_32_LAZY_GS 309 def_bool y 310 depends on X86_32 && !CC_STACKPROTECTOR 311 312config ARCH_SUPPORTS_UPROBES 313 def_bool y 314 315config FIX_EARLYCON_MEM 316 def_bool y 317 318config PGTABLE_LEVELS 319 int 320 default 4 if X86_64 321 default 3 if X86_PAE 322 default 2 323 324source "init/Kconfig" 325source "kernel/Kconfig.freezer" 326 327menu "Processor type and features" 328 329config ZONE_DMA 330 bool "DMA memory allocation support" if EXPERT 331 default y 332 help 333 DMA memory allocation support allows devices with less than 32-bit 334 addressing to allocate within the first 16MB of address space. 335 Disable if no such devices will be used. 336 337 If unsure, say Y. 338 339config SMP 340 bool "Symmetric multi-processing support" 341 ---help--- 342 This enables support for systems with more than one CPU. If you have 343 a system with only one CPU, say N. If you have a system with more 344 than one CPU, say Y. 345 346 If you say N here, the kernel will run on uni- and multiprocessor 347 machines, but will use only one CPU of a multiprocessor machine. If 348 you say Y here, the kernel will run on many, but not all, 349 uniprocessor machines. On a uniprocessor machine, the kernel 350 will run faster if you say N here. 351 352 Note that if you say Y here and choose architecture "586" or 353 "Pentium" under "Processor family", the kernel will not work on 486 354 architectures. Similarly, multiprocessor kernels for the "PPro" 355 architecture may not work on all Pentium based boards. 356 357 People using multiprocessor machines who say Y here should also say 358 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 359 Management" code will be disabled if you say Y here. 360 361 See also <file:Documentation/x86/i386/IO-APIC.txt>, 362 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 363 <http://www.tldp.org/docs.html#howto>. 364 365 If you don't know what to do here, say N. 366 367config X86_FEATURE_NAMES 368 bool "Processor feature human-readable names" if EMBEDDED 369 default y 370 ---help--- 371 This option compiles in a table of x86 feature bits and corresponding 372 names. This is required to support /proc/cpuinfo and a few kernel 373 messages. You can disable this to save space, at the expense of 374 making those few kernel messages show numeric feature bits instead. 375 376 If in doubt, say Y. 377 378config X86_FAST_FEATURE_TESTS 379 bool "Fast CPU feature tests" if EMBEDDED 380 default y 381 ---help--- 382 Some fast-paths in the kernel depend on the capabilities of the CPU. 383 Say Y here for the kernel to patch in the appropriate code at runtime 384 based on the capabilities of the CPU. The infrastructure for patching 385 code at runtime takes up some additional space; space-constrained 386 embedded systems may wish to say N here to produce smaller, slightly 387 slower code. 388 389config X86_X2APIC 390 bool "Support x2apic" 391 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 392 ---help--- 393 This enables x2apic support on CPUs that have this feature. 394 395 This allows 32-bit apic IDs (so it can support very large systems), 396 and accesses the local apic via MSRs not via mmio. 397 398 If you don't know what to do here, say N. 399 400config X86_MPPARSE 401 bool "Enable MPS table" if ACPI || SFI 402 default y 403 depends on X86_LOCAL_APIC 404 ---help--- 405 For old smp systems that do not have proper acpi support. Newer systems 406 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 407 408config X86_BIGSMP 409 bool "Support for big SMP systems with more than 8 CPUs" 410 depends on X86_32 && SMP 411 ---help--- 412 This option is needed for the systems that have more than 8 CPUs 413 414config GOLDFISH 415 def_bool y 416 depends on X86_GOLDFISH 417 418config INTEL_RDT_A 419 bool "Intel Resource Director Technology Allocation support" 420 default n 421 depends on X86 && CPU_SUP_INTEL 422 select KERNFS 423 help 424 Select to enable resource allocation which is a sub-feature of 425 Intel Resource Director Technology(RDT). More information about 426 RDT can be found in the Intel x86 Architecture Software 427 Developer Manual. 428 429 Say N if unsure. 430 431if X86_32 432config X86_EXTENDED_PLATFORM 433 bool "Support for extended (non-PC) x86 platforms" 434 default y 435 ---help--- 436 If you disable this option then the kernel will only support 437 standard PC platforms. (which covers the vast majority of 438 systems out there.) 439 440 If you enable this option then you'll be able to select support 441 for the following (non-PC) 32 bit x86 platforms: 442 Goldfish (Android emulator) 443 AMD Elan 444 RDC R-321x SoC 445 SGI 320/540 (Visual Workstation) 446 STA2X11-based (e.g. Northville) 447 Moorestown MID devices 448 449 If you have one of these systems, or if you want to build a 450 generic distribution kernel, say Y here - otherwise say N. 451endif 452 453if X86_64 454config X86_EXTENDED_PLATFORM 455 bool "Support for extended (non-PC) x86 platforms" 456 default y 457 ---help--- 458 If you disable this option then the kernel will only support 459 standard PC platforms. (which covers the vast majority of 460 systems out there.) 461 462 If you enable this option then you'll be able to select support 463 for the following (non-PC) 64 bit x86 platforms: 464 Numascale NumaChip 465 ScaleMP vSMP 466 SGI Ultraviolet 467 468 If you have one of these systems, or if you want to build a 469 generic distribution kernel, say Y here - otherwise say N. 470endif 471# This is an alphabetically sorted list of 64 bit extended platforms 472# Please maintain the alphabetic order if and when there are additions 473config X86_NUMACHIP 474 bool "Numascale NumaChip" 475 depends on X86_64 476 depends on X86_EXTENDED_PLATFORM 477 depends on NUMA 478 depends on SMP 479 depends on X86_X2APIC 480 depends on PCI_MMCONFIG 481 ---help--- 482 Adds support for Numascale NumaChip large-SMP systems. Needed to 483 enable more than ~168 cores. 484 If you don't have one of these, you should say N here. 485 486config X86_VSMP 487 bool "ScaleMP vSMP" 488 select HYPERVISOR_GUEST 489 select PARAVIRT 490 depends on X86_64 && PCI 491 depends on X86_EXTENDED_PLATFORM 492 depends on SMP 493 ---help--- 494 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 495 supposed to run on these EM64T-based machines. Only choose this option 496 if you have one of these machines. 497 498config X86_UV 499 bool "SGI Ultraviolet" 500 depends on X86_64 501 depends on X86_EXTENDED_PLATFORM 502 depends on NUMA 503 depends on EFI 504 depends on X86_X2APIC 505 depends on PCI 506 ---help--- 507 This option is needed in order to support SGI Ultraviolet systems. 508 If you don't have one of these, you should say N here. 509 510# Following is an alphabetically sorted list of 32 bit extended platforms 511# Please maintain the alphabetic order if and when there are additions 512 513config X86_GOLDFISH 514 bool "Goldfish (Virtual Platform)" 515 depends on X86_EXTENDED_PLATFORM 516 ---help--- 517 Enable support for the Goldfish virtual platform used primarily 518 for Android development. Unless you are building for the Android 519 Goldfish emulator say N here. 520 521config X86_INTEL_CE 522 bool "CE4100 TV platform" 523 depends on PCI 524 depends on PCI_GODIRECT 525 depends on X86_IO_APIC 526 depends on X86_32 527 depends on X86_EXTENDED_PLATFORM 528 select X86_REBOOTFIXUPS 529 select OF 530 select OF_EARLY_FLATTREE 531 ---help--- 532 Select for the Intel CE media processor (CE4100) SOC. 533 This option compiles in support for the CE4100 SOC for settop 534 boxes and media devices. 535 536config X86_INTEL_MID 537 bool "Intel MID platform support" 538 depends on X86_EXTENDED_PLATFORM 539 depends on X86_PLATFORM_DEVICES 540 depends on PCI 541 depends on X86_64 || (PCI_GOANY && X86_32) 542 depends on X86_IO_APIC 543 select SFI 544 select I2C 545 select DW_APB_TIMER 546 select APB_TIMER 547 select INTEL_SCU_IPC 548 select MFD_INTEL_MSIC 549 ---help--- 550 Select to build a kernel capable of supporting Intel MID (Mobile 551 Internet Device) platform systems which do not have the PCI legacy 552 interfaces. If you are building for a PC class system say N here. 553 554 Intel MID platforms are based on an Intel processor and chipset which 555 consume less power than most of the x86 derivatives. 556 557config X86_INTEL_QUARK 558 bool "Intel Quark platform support" 559 depends on X86_32 560 depends on X86_EXTENDED_PLATFORM 561 depends on X86_PLATFORM_DEVICES 562 depends on X86_TSC 563 depends on PCI 564 depends on PCI_GOANY 565 depends on X86_IO_APIC 566 select IOSF_MBI 567 select INTEL_IMR 568 select COMMON_CLK 569 ---help--- 570 Select to include support for Quark X1000 SoC. 571 Say Y here if you have a Quark based system such as the Arduino 572 compatible Intel Galileo. 573 574config X86_INTEL_LPSS 575 bool "Intel Low Power Subsystem Support" 576 depends on X86 && ACPI 577 select COMMON_CLK 578 select PINCTRL 579 select IOSF_MBI 580 ---help--- 581 Select to build support for Intel Low Power Subsystem such as 582 found on Intel Lynxpoint PCH. Selecting this option enables 583 things like clock tree (common clock framework) and pincontrol 584 which are needed by the LPSS peripheral drivers. 585 586config X86_AMD_PLATFORM_DEVICE 587 bool "AMD ACPI2Platform devices support" 588 depends on ACPI 589 select COMMON_CLK 590 select PINCTRL 591 ---help--- 592 Select to interpret AMD specific ACPI device to platform device 593 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 594 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 595 implemented under PINCTRL subsystem. 596 597config IOSF_MBI 598 tristate "Intel SoC IOSF Sideband support for SoC platforms" 599 depends on PCI 600 ---help--- 601 This option enables sideband register access support for Intel SoC 602 platforms. On these platforms the IOSF sideband is used in lieu of 603 MSR's for some register accesses, mostly but not limited to thermal 604 and power. Drivers may query the availability of this device to 605 determine if they need the sideband in order to work on these 606 platforms. The sideband is available on the following SoC products. 607 This list is not meant to be exclusive. 608 - BayTrail 609 - Braswell 610 - Quark 611 612 You should say Y if you are running a kernel on one of these SoC's. 613 614config IOSF_MBI_DEBUG 615 bool "Enable IOSF sideband access through debugfs" 616 depends on IOSF_MBI && DEBUG_FS 617 ---help--- 618 Select this option to expose the IOSF sideband access registers (MCR, 619 MDR, MCRX) through debugfs to write and read register information from 620 different units on the SoC. This is most useful for obtaining device 621 state information for debug and analysis. As this is a general access 622 mechanism, users of this option would have specific knowledge of the 623 device they want to access. 624 625 If you don't require the option or are in doubt, say N. 626 627config X86_RDC321X 628 bool "RDC R-321x SoC" 629 depends on X86_32 630 depends on X86_EXTENDED_PLATFORM 631 select M486 632 select X86_REBOOTFIXUPS 633 ---help--- 634 This option is needed for RDC R-321x system-on-chip, also known 635 as R-8610-(G). 636 If you don't have one of these chips, you should say N here. 637 638config X86_32_NON_STANDARD 639 bool "Support non-standard 32-bit SMP architectures" 640 depends on X86_32 && SMP 641 depends on X86_EXTENDED_PLATFORM 642 ---help--- 643 This option compiles in the bigsmp and STA2X11 default 644 subarchitectures. It is intended for a generic binary 645 kernel. If you select them all, kernel will probe it one by 646 one and will fallback to default. 647 648# Alphabetically sorted list of Non standard 32 bit platforms 649 650config X86_SUPPORTS_MEMORY_FAILURE 651 def_bool y 652 # MCE code calls memory_failure(): 653 depends on X86_MCE 654 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 655 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 656 depends on X86_64 || !SPARSEMEM 657 select ARCH_SUPPORTS_MEMORY_FAILURE 658 659config STA2X11 660 bool "STA2X11 Companion Chip Support" 661 depends on X86_32_NON_STANDARD && PCI 662 select X86_DEV_DMA_OPS 663 select X86_DMA_REMAP 664 select SWIOTLB 665 select MFD_STA2X11 666 select GPIOLIB 667 default n 668 ---help--- 669 This adds support for boards based on the STA2X11 IO-Hub, 670 a.k.a. "ConneXt". The chip is used in place of the standard 671 PC chipset, so all "standard" peripherals are missing. If this 672 option is selected the kernel will still be able to boot on 673 standard PC machines. 674 675config X86_32_IRIS 676 tristate "Eurobraille/Iris poweroff module" 677 depends on X86_32 678 ---help--- 679 The Iris machines from EuroBraille do not have APM or ACPI support 680 to shut themselves down properly. A special I/O sequence is 681 needed to do so, which is what this module does at 682 kernel shutdown. 683 684 This is only for Iris machines from EuroBraille. 685 686 If unused, say N. 687 688config SCHED_OMIT_FRAME_POINTER 689 def_bool y 690 prompt "Single-depth WCHAN output" 691 depends on X86 692 ---help--- 693 Calculate simpler /proc/<PID>/wchan values. If this option 694 is disabled then wchan values will recurse back to the 695 caller function. This provides more accurate wchan values, 696 at the expense of slightly more scheduling overhead. 697 698 If in doubt, say "Y". 699 700menuconfig HYPERVISOR_GUEST 701 bool "Linux guest support" 702 ---help--- 703 Say Y here to enable options for running Linux under various hyper- 704 visors. This option enables basic hypervisor detection and platform 705 setup. 706 707 If you say N, all options in this submenu will be skipped and 708 disabled, and Linux guest support won't be built in. 709 710if HYPERVISOR_GUEST 711 712config PARAVIRT 713 bool "Enable paravirtualization code" 714 ---help--- 715 This changes the kernel so it can modify itself when it is run 716 under a hypervisor, potentially improving performance significantly 717 over full virtualization. However, when run without a hypervisor 718 the kernel is theoretically slower and slightly larger. 719 720config PARAVIRT_DEBUG 721 bool "paravirt-ops debugging" 722 depends on PARAVIRT && DEBUG_KERNEL 723 ---help--- 724 Enable to debug paravirt_ops internals. Specifically, BUG if 725 a paravirt_op is missing when it is called. 726 727config PARAVIRT_SPINLOCKS 728 bool "Paravirtualization layer for spinlocks" 729 depends on PARAVIRT && SMP 730 ---help--- 731 Paravirtualized spinlocks allow a pvops backend to replace the 732 spinlock implementation with something virtualization-friendly 733 (for example, block the virtual CPU rather than spinning). 734 735 It has a minimal impact on native kernels and gives a nice performance 736 benefit on paravirtualized KVM / Xen kernels. 737 738 If you are unsure how to answer this question, answer Y. 739 740config QUEUED_LOCK_STAT 741 bool "Paravirt queued spinlock statistics" 742 depends on PARAVIRT_SPINLOCKS && DEBUG_FS 743 ---help--- 744 Enable the collection of statistical data on the slowpath 745 behavior of paravirtualized queued spinlocks and report 746 them on debugfs. 747 748source "arch/x86/xen/Kconfig" 749 750config KVM_GUEST 751 bool "KVM Guest support (including kvmclock)" 752 depends on PARAVIRT 753 select PARAVIRT_CLOCK 754 default y 755 ---help--- 756 This option enables various optimizations for running under the KVM 757 hypervisor. It includes a paravirtualized clock, so that instead 758 of relying on a PIT (or probably other) emulation by the 759 underlying device model, the host provides the guest with 760 timing infrastructure such as time of day, and system time 761 762config KVM_DEBUG_FS 763 bool "Enable debug information for KVM Guests in debugfs" 764 depends on KVM_GUEST && DEBUG_FS 765 default n 766 ---help--- 767 This option enables collection of various statistics for KVM guest. 768 Statistics are displayed in debugfs filesystem. Enabling this option 769 may incur significant overhead. 770 771source "arch/x86/lguest/Kconfig" 772 773config PARAVIRT_TIME_ACCOUNTING 774 bool "Paravirtual steal time accounting" 775 depends on PARAVIRT 776 default n 777 ---help--- 778 Select this option to enable fine granularity task steal time 779 accounting. Time spent executing other tasks in parallel with 780 the current vCPU is discounted from the vCPU power. To account for 781 that, there can be a small performance impact. 782 783 If in doubt, say N here. 784 785config PARAVIRT_CLOCK 786 bool 787 788endif #HYPERVISOR_GUEST 789 790config NO_BOOTMEM 791 def_bool y 792 793source "arch/x86/Kconfig.cpu" 794 795config HPET_TIMER 796 def_bool X86_64 797 prompt "HPET Timer Support" if X86_32 798 ---help--- 799 Use the IA-PC HPET (High Precision Event Timer) to manage 800 time in preference to the PIT and RTC, if a HPET is 801 present. 802 HPET is the next generation timer replacing legacy 8254s. 803 The HPET provides a stable time base on SMP 804 systems, unlike the TSC, but it is more expensive to access, 805 as it is off-chip. The interface used is documented 806 in the HPET spec, revision 1. 807 808 You can safely choose Y here. However, HPET will only be 809 activated if the platform and the BIOS support this feature. 810 Otherwise the 8254 will be used for timing services. 811 812 Choose N to continue using the legacy 8254 timer. 813 814config HPET_EMULATE_RTC 815 def_bool y 816 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 817 818config APB_TIMER 819 def_bool y if X86_INTEL_MID 820 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 821 select DW_APB_TIMER 822 depends on X86_INTEL_MID && SFI 823 help 824 APB timer is the replacement for 8254, HPET on X86 MID platforms. 825 The APBT provides a stable time base on SMP 826 systems, unlike the TSC, but it is more expensive to access, 827 as it is off-chip. APB timers are always running regardless of CPU 828 C states, they are used as per CPU clockevent device when possible. 829 830# Mark as expert because too many people got it wrong. 831# The code disables itself when not needed. 832config DMI 833 default y 834 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 835 bool "Enable DMI scanning" if EXPERT 836 ---help--- 837 Enabled scanning of DMI to identify machine quirks. Say Y 838 here unless you have verified that your setup is not 839 affected by entries in the DMI blacklist. Required by PNP 840 BIOS code. 841 842config GART_IOMMU 843 bool "Old AMD GART IOMMU support" 844 select SWIOTLB 845 depends on X86_64 && PCI && AMD_NB 846 ---help--- 847 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 848 GART based hardware IOMMUs. 849 850 The GART supports full DMA access for devices with 32-bit access 851 limitations, on systems with more than 3 GB. This is usually needed 852 for USB, sound, many IDE/SATA chipsets and some other devices. 853 854 Newer systems typically have a modern AMD IOMMU, supported via 855 the CONFIG_AMD_IOMMU=y config option. 856 857 In normal configurations this driver is only active when needed: 858 there's more than 3 GB of memory and the system contains a 859 32-bit limited device. 860 861 If unsure, say Y. 862 863config CALGARY_IOMMU 864 bool "IBM Calgary IOMMU support" 865 select SWIOTLB 866 depends on X86_64 && PCI 867 ---help--- 868 Support for hardware IOMMUs in IBM's xSeries x366 and x460 869 systems. Needed to run systems with more than 3GB of memory 870 properly with 32-bit PCI devices that do not support DAC 871 (Double Address Cycle). Calgary also supports bus level 872 isolation, where all DMAs pass through the IOMMU. This 873 prevents them from going anywhere except their intended 874 destination. This catches hard-to-find kernel bugs and 875 mis-behaving drivers and devices that do not use the DMA-API 876 properly to set up their DMA buffers. The IOMMU can be 877 turned off at boot time with the iommu=off parameter. 878 Normally the kernel will make the right choice by itself. 879 If unsure, say Y. 880 881config CALGARY_IOMMU_ENABLED_BY_DEFAULT 882 def_bool y 883 prompt "Should Calgary be enabled by default?" 884 depends on CALGARY_IOMMU 885 ---help--- 886 Should Calgary be enabled by default? if you choose 'y', Calgary 887 will be used (if it exists). If you choose 'n', Calgary will not be 888 used even if it exists. If you choose 'n' and would like to use 889 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 890 If unsure, say Y. 891 892# need this always selected by IOMMU for the VIA workaround 893config SWIOTLB 894 def_bool y if X86_64 895 ---help--- 896 Support for software bounce buffers used on x86-64 systems 897 which don't have a hardware IOMMU. Using this PCI devices 898 which can only access 32-bits of memory can be used on systems 899 with more than 3 GB of memory. 900 If unsure, say Y. 901 902config IOMMU_HELPER 903 def_bool y 904 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 905 906config MAXSMP 907 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 908 depends on X86_64 && SMP && DEBUG_KERNEL 909 select CPUMASK_OFFSTACK 910 ---help--- 911 Enable maximum number of CPUS and NUMA Nodes for this architecture. 912 If unsure, say N. 913 914config NR_CPUS 915 int "Maximum number of CPUs" if SMP && !MAXSMP 916 range 2 8 if SMP && X86_32 && !X86_BIGSMP 917 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 918 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 919 default "1" if !SMP 920 default "8192" if MAXSMP 921 default "32" if SMP && X86_BIGSMP 922 default "8" if SMP && X86_32 923 default "64" if SMP 924 ---help--- 925 This allows you to specify the maximum number of CPUs which this 926 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 927 supported value is 8192, otherwise the maximum value is 512. The 928 minimum value which makes sense is 2. 929 930 This is purely to save memory - each supported CPU adds 931 approximately eight kilobytes to the kernel image. 932 933config SCHED_SMT 934 bool "SMT (Hyperthreading) scheduler support" 935 depends on SMP 936 ---help--- 937 SMT scheduler support improves the CPU scheduler's decision making 938 when dealing with Intel Pentium 4 chips with HyperThreading at a 939 cost of slightly increased overhead in some places. If unsure say 940 N here. 941 942config SCHED_MC 943 def_bool y 944 prompt "Multi-core scheduler support" 945 depends on SMP 946 ---help--- 947 Multi-core scheduler support improves the CPU scheduler's decision 948 making when dealing with multi-core CPU chips at a cost of slightly 949 increased overhead in some places. If unsure say N here. 950 951config SCHED_MC_PRIO 952 bool "CPU core priorities scheduler support" 953 depends on SCHED_MC && CPU_SUP_INTEL 954 select X86_INTEL_PSTATE 955 select CPU_FREQ 956 default y 957 ---help--- 958 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 959 core ordering determined at manufacturing time, which allows 960 certain cores to reach higher turbo frequencies (when running 961 single threaded workloads) than others. 962 963 Enabling this kernel feature teaches the scheduler about 964 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 965 scheduler's CPU selection logic accordingly, so that higher 966 overall system performance can be achieved. 967 968 This feature will have no effect on CPUs without this feature. 969 970 If unsure say Y here. 971 972source "kernel/Kconfig.preempt" 973 974config UP_LATE_INIT 975 def_bool y 976 depends on !SMP && X86_LOCAL_APIC 977 978config X86_UP_APIC 979 bool "Local APIC support on uniprocessors" if !PCI_MSI 980 default PCI_MSI 981 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 982 ---help--- 983 A local APIC (Advanced Programmable Interrupt Controller) is an 984 integrated interrupt controller in the CPU. If you have a single-CPU 985 system which has a processor with a local APIC, you can say Y here to 986 enable and use it. If you say Y here even though your machine doesn't 987 have a local APIC, then the kernel will still run with no slowdown at 988 all. The local APIC supports CPU-generated self-interrupts (timer, 989 performance counters), and the NMI watchdog which detects hard 990 lockups. 991 992config X86_UP_IOAPIC 993 bool "IO-APIC support on uniprocessors" 994 depends on X86_UP_APIC 995 ---help--- 996 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 997 SMP-capable replacement for PC-style interrupt controllers. Most 998 SMP systems and many recent uniprocessor systems have one. 999 1000 If you have a single-CPU system with an IO-APIC, you can say Y here 1001 to use it. If you say Y here even though your machine doesn't have 1002 an IO-APIC, then the kernel will still run with no slowdown at all. 1003 1004config X86_LOCAL_APIC 1005 def_bool y 1006 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1007 select IRQ_DOMAIN_HIERARCHY 1008 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1009 1010config X86_IO_APIC 1011 def_bool y 1012 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1013 1014config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1015 bool "Reroute for broken boot IRQs" 1016 depends on X86_IO_APIC 1017 ---help--- 1018 This option enables a workaround that fixes a source of 1019 spurious interrupts. This is recommended when threaded 1020 interrupt handling is used on systems where the generation of 1021 superfluous "boot interrupts" cannot be disabled. 1022 1023 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1024 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1025 kernel does during interrupt handling). On chipsets where this 1026 boot IRQ generation cannot be disabled, this workaround keeps 1027 the original IRQ line masked so that only the equivalent "boot 1028 IRQ" is delivered to the CPUs. The workaround also tells the 1029 kernel to set up the IRQ handler on the boot IRQ line. In this 1030 way only one interrupt is delivered to the kernel. Otherwise 1031 the spurious second interrupt may cause the kernel to bring 1032 down (vital) interrupt lines. 1033 1034 Only affects "broken" chipsets. Interrupt sharing may be 1035 increased on these systems. 1036 1037config X86_MCE 1038 bool "Machine Check / overheating reporting" 1039 select GENERIC_ALLOCATOR 1040 default y 1041 ---help--- 1042 Machine Check support allows the processor to notify the 1043 kernel if it detects a problem (e.g. overheating, data corruption). 1044 The action the kernel takes depends on the severity of the problem, 1045 ranging from warning messages to halting the machine. 1046 1047config X86_MCE_INTEL 1048 def_bool y 1049 prompt "Intel MCE features" 1050 depends on X86_MCE && X86_LOCAL_APIC 1051 ---help--- 1052 Additional support for intel specific MCE features such as 1053 the thermal monitor. 1054 1055config X86_MCE_AMD 1056 def_bool y 1057 prompt "AMD MCE features" 1058 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1059 ---help--- 1060 Additional support for AMD specific MCE features such as 1061 the DRAM Error Threshold. 1062 1063config X86_ANCIENT_MCE 1064 bool "Support for old Pentium 5 / WinChip machine checks" 1065 depends on X86_32 && X86_MCE 1066 ---help--- 1067 Include support for machine check handling on old Pentium 5 or WinChip 1068 systems. These typically need to be enabled explicitly on the command 1069 line. 1070 1071config X86_MCE_THRESHOLD 1072 depends on X86_MCE_AMD || X86_MCE_INTEL 1073 def_bool y 1074 1075config X86_MCE_INJECT 1076 depends on X86_MCE && X86_LOCAL_APIC 1077 tristate "Machine check injector support" 1078 ---help--- 1079 Provide support for injecting machine checks for testing purposes. 1080 If you don't know what a machine check is and you don't do kernel 1081 QA it is safe to say n. 1082 1083config X86_THERMAL_VECTOR 1084 def_bool y 1085 depends on X86_MCE_INTEL 1086 1087source "arch/x86/events/Kconfig" 1088 1089config X86_LEGACY_VM86 1090 bool "Legacy VM86 support" 1091 default n 1092 depends on X86_32 1093 ---help--- 1094 This option allows user programs to put the CPU into V8086 1095 mode, which is an 80286-era approximation of 16-bit real mode. 1096 1097 Some very old versions of X and/or vbetool require this option 1098 for user mode setting. Similarly, DOSEMU will use it if 1099 available to accelerate real mode DOS programs. However, any 1100 recent version of DOSEMU, X, or vbetool should be fully 1101 functional even without kernel VM86 support, as they will all 1102 fall back to software emulation. Nevertheless, if you are using 1103 a 16-bit DOS program where 16-bit performance matters, vm86 1104 mode might be faster than emulation and you might want to 1105 enable this option. 1106 1107 Note that any app that works on a 64-bit kernel is unlikely to 1108 need this option, as 64-bit kernels don't, and can't, support 1109 V8086 mode. This option is also unrelated to 16-bit protected 1110 mode and is not needed to run most 16-bit programs under Wine. 1111 1112 Enabling this option increases the complexity of the kernel 1113 and slows down exception handling a tiny bit. 1114 1115 If unsure, say N here. 1116 1117config VM86 1118 bool 1119 default X86_LEGACY_VM86 1120 1121config X86_16BIT 1122 bool "Enable support for 16-bit segments" if EXPERT 1123 default y 1124 depends on MODIFY_LDT_SYSCALL 1125 ---help--- 1126 This option is required by programs like Wine to run 16-bit 1127 protected mode legacy code on x86 processors. Disabling 1128 this option saves about 300 bytes on i386, or around 6K text 1129 plus 16K runtime memory on x86-64, 1130 1131config X86_ESPFIX32 1132 def_bool y 1133 depends on X86_16BIT && X86_32 1134 1135config X86_ESPFIX64 1136 def_bool y 1137 depends on X86_16BIT && X86_64 1138 1139config X86_VSYSCALL_EMULATION 1140 bool "Enable vsyscall emulation" if EXPERT 1141 default y 1142 depends on X86_64 1143 ---help--- 1144 This enables emulation of the legacy vsyscall page. Disabling 1145 it is roughly equivalent to booting with vsyscall=none, except 1146 that it will also disable the helpful warning if a program 1147 tries to use a vsyscall. With this option set to N, offending 1148 programs will just segfault, citing addresses of the form 1149 0xffffffffff600?00. 1150 1151 This option is required by many programs built before 2013, and 1152 care should be used even with newer programs if set to N. 1153 1154 Disabling this option saves about 7K of kernel size and 1155 possibly 4K of additional runtime pagetable memory. 1156 1157config TOSHIBA 1158 tristate "Toshiba Laptop support" 1159 depends on X86_32 1160 ---help--- 1161 This adds a driver to safely access the System Management Mode of 1162 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1163 not work on models with a Phoenix BIOS. The System Management Mode 1164 is used to set the BIOS and power saving options on Toshiba portables. 1165 1166 For information on utilities to make use of this driver see the 1167 Toshiba Linux utilities web site at: 1168 <http://www.buzzard.org.uk/toshiba/>. 1169 1170 Say Y if you intend to run this kernel on a Toshiba portable. 1171 Say N otherwise. 1172 1173config I8K 1174 tristate "Dell i8k legacy laptop support" 1175 select HWMON 1176 select SENSORS_DELL_SMM 1177 ---help--- 1178 This option enables legacy /proc/i8k userspace interface in hwmon 1179 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1180 temperature and allows controlling fan speeds of Dell laptops via 1181 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1182 it reports also power and hotkey status. For fan speed control is 1183 needed userspace package i8kutils. 1184 1185 Say Y if you intend to run this kernel on old Dell laptops or want to 1186 use userspace package i8kutils. 1187 Say N otherwise. 1188 1189config X86_REBOOTFIXUPS 1190 bool "Enable X86 board specific fixups for reboot" 1191 depends on X86_32 1192 ---help--- 1193 This enables chipset and/or board specific fixups to be done 1194 in order to get reboot to work correctly. This is only needed on 1195 some combinations of hardware and BIOS. The symptom, for which 1196 this config is intended, is when reboot ends with a stalled/hung 1197 system. 1198 1199 Currently, the only fixup is for the Geode machines using 1200 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1201 1202 Say Y if you want to enable the fixup. Currently, it's safe to 1203 enable this option even if you don't need it. 1204 Say N otherwise. 1205 1206config MICROCODE 1207 bool "CPU microcode loading support" 1208 default y 1209 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1210 select FW_LOADER 1211 ---help--- 1212 If you say Y here, you will be able to update the microcode on 1213 Intel and AMD processors. The Intel support is for the IA32 family, 1214 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1215 AMD support is for families 0x10 and later. You will obviously need 1216 the actual microcode binary data itself which is not shipped with 1217 the Linux kernel. 1218 1219 The preferred method to load microcode from a detached initrd is described 1220 in Documentation/x86/early-microcode.txt. For that you need to enable 1221 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1222 initrd for microcode blobs. 1223 1224 In addition, you can build-in the microcode into the kernel. For that you 1225 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode 1226 to the CONFIG_EXTRA_FIRMWARE config option. 1227 1228config MICROCODE_INTEL 1229 bool "Intel microcode loading support" 1230 depends on MICROCODE 1231 default MICROCODE 1232 select FW_LOADER 1233 ---help--- 1234 This options enables microcode patch loading support for Intel 1235 processors. 1236 1237 For the current Intel microcode data package go to 1238 <https://downloadcenter.intel.com> and search for 1239 'Linux Processor Microcode Data File'. 1240 1241config MICROCODE_AMD 1242 bool "AMD microcode loading support" 1243 depends on MICROCODE 1244 select FW_LOADER 1245 ---help--- 1246 If you select this option, microcode patch loading support for AMD 1247 processors will be enabled. 1248 1249config MICROCODE_OLD_INTERFACE 1250 def_bool y 1251 depends on MICROCODE 1252 1253config X86_MSR 1254 tristate "/dev/cpu/*/msr - Model-specific register support" 1255 ---help--- 1256 This device gives privileged processes access to the x86 1257 Model-Specific Registers (MSRs). It is a character device with 1258 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1259 MSR accesses are directed to a specific CPU on multi-processor 1260 systems. 1261 1262config X86_CPUID 1263 tristate "/dev/cpu/*/cpuid - CPU information support" 1264 ---help--- 1265 This device gives processes access to the x86 CPUID instruction to 1266 be executed on a specific processor. It is a character device 1267 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1268 /dev/cpu/31/cpuid. 1269 1270choice 1271 prompt "High Memory Support" 1272 default HIGHMEM4G 1273 depends on X86_32 1274 1275config NOHIGHMEM 1276 bool "off" 1277 ---help--- 1278 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1279 However, the address space of 32-bit x86 processors is only 4 1280 Gigabytes large. That means that, if you have a large amount of 1281 physical memory, not all of it can be "permanently mapped" by the 1282 kernel. The physical memory that's not permanently mapped is called 1283 "high memory". 1284 1285 If you are compiling a kernel which will never run on a machine with 1286 more than 1 Gigabyte total physical RAM, answer "off" here (default 1287 choice and suitable for most users). This will result in a "3GB/1GB" 1288 split: 3GB are mapped so that each process sees a 3GB virtual memory 1289 space and the remaining part of the 4GB virtual memory space is used 1290 by the kernel to permanently map as much physical memory as 1291 possible. 1292 1293 If the machine has between 1 and 4 Gigabytes physical RAM, then 1294 answer "4GB" here. 1295 1296 If more than 4 Gigabytes is used then answer "64GB" here. This 1297 selection turns Intel PAE (Physical Address Extension) mode on. 1298 PAE implements 3-level paging on IA32 processors. PAE is fully 1299 supported by Linux, PAE mode is implemented on all recent Intel 1300 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1301 then the kernel will not boot on CPUs that don't support PAE! 1302 1303 The actual amount of total physical memory will either be 1304 auto detected or can be forced by using a kernel command line option 1305 such as "mem=256M". (Try "man bootparam" or see the documentation of 1306 your boot loader (lilo or loadlin) about how to pass options to the 1307 kernel at boot time.) 1308 1309 If unsure, say "off". 1310 1311config HIGHMEM4G 1312 bool "4GB" 1313 ---help--- 1314 Select this if you have a 32-bit processor and between 1 and 4 1315 gigabytes of physical RAM. 1316 1317config HIGHMEM64G 1318 bool "64GB" 1319 depends on !M486 1320 select X86_PAE 1321 ---help--- 1322 Select this if you have a 32-bit processor and more than 4 1323 gigabytes of physical RAM. 1324 1325endchoice 1326 1327choice 1328 prompt "Memory split" if EXPERT 1329 default VMSPLIT_3G 1330 depends on X86_32 1331 ---help--- 1332 Select the desired split between kernel and user memory. 1333 1334 If the address range available to the kernel is less than the 1335 physical memory installed, the remaining memory will be available 1336 as "high memory". Accessing high memory is a little more costly 1337 than low memory, as it needs to be mapped into the kernel first. 1338 Note that increasing the kernel address space limits the range 1339 available to user programs, making the address space there 1340 tighter. Selecting anything other than the default 3G/1G split 1341 will also likely make your kernel incompatible with binary-only 1342 kernel modules. 1343 1344 If you are not absolutely sure what you are doing, leave this 1345 option alone! 1346 1347 config VMSPLIT_3G 1348 bool "3G/1G user/kernel split" 1349 config VMSPLIT_3G_OPT 1350 depends on !X86_PAE 1351 bool "3G/1G user/kernel split (for full 1G low memory)" 1352 config VMSPLIT_2G 1353 bool "2G/2G user/kernel split" 1354 config VMSPLIT_2G_OPT 1355 depends on !X86_PAE 1356 bool "2G/2G user/kernel split (for full 2G low memory)" 1357 config VMSPLIT_1G 1358 bool "1G/3G user/kernel split" 1359endchoice 1360 1361config PAGE_OFFSET 1362 hex 1363 default 0xB0000000 if VMSPLIT_3G_OPT 1364 default 0x80000000 if VMSPLIT_2G 1365 default 0x78000000 if VMSPLIT_2G_OPT 1366 default 0x40000000 if VMSPLIT_1G 1367 default 0xC0000000 1368 depends on X86_32 1369 1370config HIGHMEM 1371 def_bool y 1372 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1373 1374config X86_PAE 1375 bool "PAE (Physical Address Extension) Support" 1376 depends on X86_32 && !HIGHMEM4G 1377 select SWIOTLB 1378 ---help--- 1379 PAE is required for NX support, and furthermore enables 1380 larger swapspace support for non-overcommit purposes. It 1381 has the cost of more pagetable lookup overhead, and also 1382 consumes more pagetable space per process. 1383 1384config ARCH_PHYS_ADDR_T_64BIT 1385 def_bool y 1386 depends on X86_64 || X86_PAE 1387 1388config ARCH_DMA_ADDR_T_64BIT 1389 def_bool y 1390 depends on X86_64 || HIGHMEM64G 1391 1392config X86_DIRECT_GBPAGES 1393 def_bool y 1394 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 1395 ---help--- 1396 Certain kernel features effectively disable kernel 1397 linear 1 GB mappings (even if the CPU otherwise 1398 supports them), so don't confuse the user by printing 1399 that we have them enabled. 1400 1401# Common NUMA Features 1402config NUMA 1403 bool "Numa Memory Allocation and Scheduler Support" 1404 depends on SMP 1405 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1406 default y if X86_BIGSMP 1407 ---help--- 1408 Enable NUMA (Non Uniform Memory Access) support. 1409 1410 The kernel will try to allocate memory used by a CPU on the 1411 local memory controller of the CPU and add some more 1412 NUMA awareness to the kernel. 1413 1414 For 64-bit this is recommended if the system is Intel Core i7 1415 (or later), AMD Opteron, or EM64T NUMA. 1416 1417 For 32-bit this is only needed if you boot a 32-bit 1418 kernel on a 64-bit NUMA platform. 1419 1420 Otherwise, you should say N. 1421 1422config AMD_NUMA 1423 def_bool y 1424 prompt "Old style AMD Opteron NUMA detection" 1425 depends on X86_64 && NUMA && PCI 1426 ---help--- 1427 Enable AMD NUMA node topology detection. You should say Y here if 1428 you have a multi processor AMD system. This uses an old method to 1429 read the NUMA configuration directly from the builtin Northbridge 1430 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1431 which also takes priority if both are compiled in. 1432 1433config X86_64_ACPI_NUMA 1434 def_bool y 1435 prompt "ACPI NUMA detection" 1436 depends on X86_64 && NUMA && ACPI && PCI 1437 select ACPI_NUMA 1438 ---help--- 1439 Enable ACPI SRAT based node topology detection. 1440 1441# Some NUMA nodes have memory ranges that span 1442# other nodes. Even though a pfn is valid and 1443# between a node's start and end pfns, it may not 1444# reside on that node. See memmap_init_zone() 1445# for details. 1446config NODES_SPAN_OTHER_NODES 1447 def_bool y 1448 depends on X86_64_ACPI_NUMA 1449 1450config NUMA_EMU 1451 bool "NUMA emulation" 1452 depends on NUMA 1453 ---help--- 1454 Enable NUMA emulation. A flat machine will be split 1455 into virtual nodes when booted with "numa=fake=N", where N is the 1456 number of nodes. This is only useful for debugging. 1457 1458config NODES_SHIFT 1459 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1460 range 1 10 1461 default "10" if MAXSMP 1462 default "6" if X86_64 1463 default "3" 1464 depends on NEED_MULTIPLE_NODES 1465 ---help--- 1466 Specify the maximum number of NUMA Nodes available on the target 1467 system. Increases memory reserved to accommodate various tables. 1468 1469config ARCH_HAVE_MEMORY_PRESENT 1470 def_bool y 1471 depends on X86_32 && DISCONTIGMEM 1472 1473config NEED_NODE_MEMMAP_SIZE 1474 def_bool y 1475 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1476 1477config ARCH_FLATMEM_ENABLE 1478 def_bool y 1479 depends on X86_32 && !NUMA 1480 1481config ARCH_DISCONTIGMEM_ENABLE 1482 def_bool y 1483 depends on NUMA && X86_32 1484 1485config ARCH_DISCONTIGMEM_DEFAULT 1486 def_bool y 1487 depends on NUMA && X86_32 1488 1489config ARCH_SPARSEMEM_ENABLE 1490 def_bool y 1491 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1492 select SPARSEMEM_STATIC if X86_32 1493 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1494 1495config ARCH_SPARSEMEM_DEFAULT 1496 def_bool y 1497 depends on X86_64 1498 1499config ARCH_SELECT_MEMORY_MODEL 1500 def_bool y 1501 depends on ARCH_SPARSEMEM_ENABLE 1502 1503config ARCH_MEMORY_PROBE 1504 bool "Enable sysfs memory/probe interface" 1505 depends on X86_64 && MEMORY_HOTPLUG 1506 help 1507 This option enables a sysfs memory/probe interface for testing. 1508 See Documentation/memory-hotplug.txt for more information. 1509 If you are unsure how to answer this question, answer N. 1510 1511config ARCH_PROC_KCORE_TEXT 1512 def_bool y 1513 depends on X86_64 && PROC_KCORE 1514 1515config ILLEGAL_POINTER_VALUE 1516 hex 1517 default 0 if X86_32 1518 default 0xdead000000000000 if X86_64 1519 1520source "mm/Kconfig" 1521 1522config X86_PMEM_LEGACY_DEVICE 1523 bool 1524 1525config X86_PMEM_LEGACY 1526 tristate "Support non-standard NVDIMMs and ADR protected memory" 1527 depends on PHYS_ADDR_T_64BIT 1528 depends on BLK_DEV 1529 select X86_PMEM_LEGACY_DEVICE 1530 select LIBNVDIMM 1531 help 1532 Treat memory marked using the non-standard e820 type of 12 as used 1533 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1534 The kernel will offer these regions to the 'pmem' driver so 1535 they can be used for persistent storage. 1536 1537 Say Y if unsure. 1538 1539config HIGHPTE 1540 bool "Allocate 3rd-level pagetables from highmem" 1541 depends on HIGHMEM 1542 ---help--- 1543 The VM uses one page table entry for each page of physical memory. 1544 For systems with a lot of RAM, this can be wasteful of precious 1545 low memory. Setting this option will put user-space page table 1546 entries in high memory. 1547 1548config X86_CHECK_BIOS_CORRUPTION 1549 bool "Check for low memory corruption" 1550 ---help--- 1551 Periodically check for memory corruption in low memory, which 1552 is suspected to be caused by BIOS. Even when enabled in the 1553 configuration, it is disabled at runtime. Enable it by 1554 setting "memory_corruption_check=1" on the kernel command 1555 line. By default it scans the low 64k of memory every 60 1556 seconds; see the memory_corruption_check_size and 1557 memory_corruption_check_period parameters in 1558 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1559 1560 When enabled with the default parameters, this option has 1561 almost no overhead, as it reserves a relatively small amount 1562 of memory and scans it infrequently. It both detects corruption 1563 and prevents it from affecting the running system. 1564 1565 It is, however, intended as a diagnostic tool; if repeatable 1566 BIOS-originated corruption always affects the same memory, 1567 you can use memmap= to prevent the kernel from using that 1568 memory. 1569 1570config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1571 bool "Set the default setting of memory_corruption_check" 1572 depends on X86_CHECK_BIOS_CORRUPTION 1573 default y 1574 ---help--- 1575 Set whether the default state of memory_corruption_check is 1576 on or off. 1577 1578config X86_RESERVE_LOW 1579 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1580 default 64 1581 range 4 640 1582 ---help--- 1583 Specify the amount of low memory to reserve for the BIOS. 1584 1585 The first page contains BIOS data structures that the kernel 1586 must not use, so that page must always be reserved. 1587 1588 By default we reserve the first 64K of physical RAM, as a 1589 number of BIOSes are known to corrupt that memory range 1590 during events such as suspend/resume or monitor cable 1591 insertion, so it must not be used by the kernel. 1592 1593 You can set this to 4 if you are absolutely sure that you 1594 trust the BIOS to get all its memory reservations and usages 1595 right. If you know your BIOS have problems beyond the 1596 default 64K area, you can set this to 640 to avoid using the 1597 entire low memory range. 1598 1599 If you have doubts about the BIOS (e.g. suspend/resume does 1600 not work or there's kernel crashes after certain hardware 1601 hotplug events) then you might want to enable 1602 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1603 typical corruption patterns. 1604 1605 Leave this to the default value of 64 if you are unsure. 1606 1607config MATH_EMULATION 1608 bool 1609 depends on MODIFY_LDT_SYSCALL 1610 prompt "Math emulation" if X86_32 1611 ---help--- 1612 Linux can emulate a math coprocessor (used for floating point 1613 operations) if you don't have one. 486DX and Pentium processors have 1614 a math coprocessor built in, 486SX and 386 do not, unless you added 1615 a 487DX or 387, respectively. (The messages during boot time can 1616 give you some hints here ["man dmesg"].) Everyone needs either a 1617 coprocessor or this emulation. 1618 1619 If you don't have a math coprocessor, you need to say Y here; if you 1620 say Y here even though you have a coprocessor, the coprocessor will 1621 be used nevertheless. (This behavior can be changed with the kernel 1622 command line option "no387", which comes handy if your coprocessor 1623 is broken. Try "man bootparam" or see the documentation of your boot 1624 loader (lilo or loadlin) about how to pass options to the kernel at 1625 boot time.) This means that it is a good idea to say Y here if you 1626 intend to use this kernel on different machines. 1627 1628 More information about the internals of the Linux math coprocessor 1629 emulation can be found in <file:arch/x86/math-emu/README>. 1630 1631 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1632 kernel, it won't hurt. 1633 1634config MTRR 1635 def_bool y 1636 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1637 ---help--- 1638 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1639 the Memory Type Range Registers (MTRRs) may be used to control 1640 processor access to memory ranges. This is most useful if you have 1641 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1642 allows bus write transfers to be combined into a larger transfer 1643 before bursting over the PCI/AGP bus. This can increase performance 1644 of image write operations 2.5 times or more. Saying Y here creates a 1645 /proc/mtrr file which may be used to manipulate your processor's 1646 MTRRs. Typically the X server should use this. 1647 1648 This code has a reasonably generic interface so that similar 1649 control registers on other processors can be easily supported 1650 as well: 1651 1652 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1653 Registers (ARRs) which provide a similar functionality to MTRRs. For 1654 these, the ARRs are used to emulate the MTRRs. 1655 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1656 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1657 write-combining. All of these processors are supported by this code 1658 and it makes sense to say Y here if you have one of them. 1659 1660 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1661 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1662 can lead to all sorts of problems, so it's good to say Y here. 1663 1664 You can safely say Y even if your machine doesn't have MTRRs, you'll 1665 just add about 9 KB to your kernel. 1666 1667 See <file:Documentation/x86/mtrr.txt> for more information. 1668 1669config MTRR_SANITIZER 1670 def_bool y 1671 prompt "MTRR cleanup support" 1672 depends on MTRR 1673 ---help--- 1674 Convert MTRR layout from continuous to discrete, so X drivers can 1675 add writeback entries. 1676 1677 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1678 The largest mtrr entry size for a continuous block can be set with 1679 mtrr_chunk_size. 1680 1681 If unsure, say Y. 1682 1683config MTRR_SANITIZER_ENABLE_DEFAULT 1684 int "MTRR cleanup enable value (0-1)" 1685 range 0 1 1686 default "0" 1687 depends on MTRR_SANITIZER 1688 ---help--- 1689 Enable mtrr cleanup default value 1690 1691config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1692 int "MTRR cleanup spare reg num (0-7)" 1693 range 0 7 1694 default "1" 1695 depends on MTRR_SANITIZER 1696 ---help--- 1697 mtrr cleanup spare entries default, it can be changed via 1698 mtrr_spare_reg_nr=N on the kernel command line. 1699 1700config X86_PAT 1701 def_bool y 1702 prompt "x86 PAT support" if EXPERT 1703 depends on MTRR 1704 ---help--- 1705 Use PAT attributes to setup page level cache control. 1706 1707 PATs are the modern equivalents of MTRRs and are much more 1708 flexible than MTRRs. 1709 1710 Say N here if you see bootup problems (boot crash, boot hang, 1711 spontaneous reboots) or a non-working video driver. 1712 1713 If unsure, say Y. 1714 1715config ARCH_USES_PG_UNCACHED 1716 def_bool y 1717 depends on X86_PAT 1718 1719config ARCH_RANDOM 1720 def_bool y 1721 prompt "x86 architectural random number generator" if EXPERT 1722 ---help--- 1723 Enable the x86 architectural RDRAND instruction 1724 (Intel Bull Mountain technology) to generate random numbers. 1725 If supported, this is a high bandwidth, cryptographically 1726 secure hardware random number generator. 1727 1728config X86_SMAP 1729 def_bool y 1730 prompt "Supervisor Mode Access Prevention" if EXPERT 1731 ---help--- 1732 Supervisor Mode Access Prevention (SMAP) is a security 1733 feature in newer Intel processors. There is a small 1734 performance cost if this enabled and turned on; there is 1735 also a small increase in the kernel size if this is enabled. 1736 1737 If unsure, say Y. 1738 1739config X86_INTEL_MPX 1740 prompt "Intel MPX (Memory Protection Extensions)" 1741 def_bool n 1742 depends on CPU_SUP_INTEL 1743 ---help--- 1744 MPX provides hardware features that can be used in 1745 conjunction with compiler-instrumented code to check 1746 memory references. It is designed to detect buffer 1747 overflow or underflow bugs. 1748 1749 This option enables running applications which are 1750 instrumented or otherwise use MPX. It does not use MPX 1751 itself inside the kernel or to protect the kernel 1752 against bad memory references. 1753 1754 Enabling this option will make the kernel larger: 1755 ~8k of kernel text and 36 bytes of data on a 64-bit 1756 defconfig. It adds a long to the 'mm_struct' which 1757 will increase the kernel memory overhead of each 1758 process and adds some branches to paths used during 1759 exec() and munmap(). 1760 1761 For details, see Documentation/x86/intel_mpx.txt 1762 1763 If unsure, say N. 1764 1765config X86_INTEL_MEMORY_PROTECTION_KEYS 1766 prompt "Intel Memory Protection Keys" 1767 def_bool y 1768 # Note: only available in 64-bit mode 1769 depends on CPU_SUP_INTEL && X86_64 1770 select ARCH_USES_HIGH_VMA_FLAGS 1771 select ARCH_HAS_PKEYS 1772 ---help--- 1773 Memory Protection Keys provides a mechanism for enforcing 1774 page-based protections, but without requiring modification of the 1775 page tables when an application changes protection domains. 1776 1777 For details, see Documentation/x86/protection-keys.txt 1778 1779 If unsure, say y. 1780 1781config EFI 1782 bool "EFI runtime service support" 1783 depends on ACPI 1784 select UCS2_STRING 1785 select EFI_RUNTIME_WRAPPERS 1786 ---help--- 1787 This enables the kernel to use EFI runtime services that are 1788 available (such as the EFI variable services). 1789 1790 This option is only useful on systems that have EFI firmware. 1791 In addition, you should use the latest ELILO loader available 1792 at <http://elilo.sourceforge.net> in order to take advantage 1793 of EFI runtime services. However, even with this option, the 1794 resultant kernel should continue to boot on existing non-EFI 1795 platforms. 1796 1797config EFI_STUB 1798 bool "EFI stub support" 1799 depends on EFI && !X86_USE_3DNOW 1800 select RELOCATABLE 1801 ---help--- 1802 This kernel feature allows a bzImage to be loaded directly 1803 by EFI firmware without the use of a bootloader. 1804 1805 See Documentation/efi-stub.txt for more information. 1806 1807config EFI_MIXED 1808 bool "EFI mixed-mode support" 1809 depends on EFI_STUB && X86_64 1810 ---help--- 1811 Enabling this feature allows a 64-bit kernel to be booted 1812 on a 32-bit firmware, provided that your CPU supports 64-bit 1813 mode. 1814 1815 Note that it is not possible to boot a mixed-mode enabled 1816 kernel via the EFI boot stub - a bootloader that supports 1817 the EFI handover protocol must be used. 1818 1819 If unsure, say N. 1820 1821config SECCOMP 1822 def_bool y 1823 prompt "Enable seccomp to safely compute untrusted bytecode" 1824 ---help--- 1825 This kernel feature is useful for number crunching applications 1826 that may need to compute untrusted bytecode during their 1827 execution. By using pipes or other transports made available to 1828 the process as file descriptors supporting the read/write 1829 syscalls, it's possible to isolate those applications in 1830 their own address space using seccomp. Once seccomp is 1831 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1832 and the task is only allowed to execute a few safe syscalls 1833 defined by each seccomp mode. 1834 1835 If unsure, say Y. Only embedded should say N here. 1836 1837source kernel/Kconfig.hz 1838 1839config KEXEC 1840 bool "kexec system call" 1841 select KEXEC_CORE 1842 ---help--- 1843 kexec is a system call that implements the ability to shutdown your 1844 current kernel, and to start another kernel. It is like a reboot 1845 but it is independent of the system firmware. And like a reboot 1846 you can start any kernel with it, not just Linux. 1847 1848 The name comes from the similarity to the exec system call. 1849 1850 It is an ongoing process to be certain the hardware in a machine 1851 is properly shutdown, so do not be surprised if this code does not 1852 initially work for you. As of this writing the exact hardware 1853 interface is strongly in flux, so no good recommendation can be 1854 made. 1855 1856config KEXEC_FILE 1857 bool "kexec file based system call" 1858 select KEXEC_CORE 1859 select BUILD_BIN2C 1860 depends on X86_64 1861 depends on CRYPTO=y 1862 depends on CRYPTO_SHA256=y 1863 ---help--- 1864 This is new version of kexec system call. This system call is 1865 file based and takes file descriptors as system call argument 1866 for kernel and initramfs as opposed to list of segments as 1867 accepted by previous system call. 1868 1869config KEXEC_VERIFY_SIG 1870 bool "Verify kernel signature during kexec_file_load() syscall" 1871 depends on KEXEC_FILE 1872 ---help--- 1873 This option makes kernel signature verification mandatory for 1874 the kexec_file_load() syscall. 1875 1876 In addition to that option, you need to enable signature 1877 verification for the corresponding kernel image type being 1878 loaded in order for this to work. 1879 1880config KEXEC_BZIMAGE_VERIFY_SIG 1881 bool "Enable bzImage signature verification support" 1882 depends on KEXEC_VERIFY_SIG 1883 depends on SIGNED_PE_FILE_VERIFICATION 1884 select SYSTEM_TRUSTED_KEYRING 1885 ---help--- 1886 Enable bzImage signature verification support. 1887 1888config CRASH_DUMP 1889 bool "kernel crash dumps" 1890 depends on X86_64 || (X86_32 && HIGHMEM) 1891 ---help--- 1892 Generate crash dump after being started by kexec. 1893 This should be normally only set in special crash dump kernels 1894 which are loaded in the main kernel with kexec-tools into 1895 a specially reserved region and then later executed after 1896 a crash by kdump/kexec. The crash dump kernel must be compiled 1897 to a memory address not used by the main kernel or BIOS using 1898 PHYSICAL_START, or it must be built as a relocatable image 1899 (CONFIG_RELOCATABLE=y). 1900 For more details see Documentation/kdump/kdump.txt 1901 1902config KEXEC_JUMP 1903 bool "kexec jump" 1904 depends on KEXEC && HIBERNATION 1905 ---help--- 1906 Jump between original kernel and kexeced kernel and invoke 1907 code in physical address mode via KEXEC 1908 1909config PHYSICAL_START 1910 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1911 default "0x1000000" 1912 ---help--- 1913 This gives the physical address where the kernel is loaded. 1914 1915 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1916 bzImage will decompress itself to above physical address and 1917 run from there. Otherwise, bzImage will run from the address where 1918 it has been loaded by the boot loader and will ignore above physical 1919 address. 1920 1921 In normal kdump cases one does not have to set/change this option 1922 as now bzImage can be compiled as a completely relocatable image 1923 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1924 address. This option is mainly useful for the folks who don't want 1925 to use a bzImage for capturing the crash dump and want to use a 1926 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1927 to be specifically compiled to run from a specific memory area 1928 (normally a reserved region) and this option comes handy. 1929 1930 So if you are using bzImage for capturing the crash dump, 1931 leave the value here unchanged to 0x1000000 and set 1932 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1933 for capturing the crash dump change this value to start of 1934 the reserved region. In other words, it can be set based on 1935 the "X" value as specified in the "crashkernel=YM@XM" 1936 command line boot parameter passed to the panic-ed 1937 kernel. Please take a look at Documentation/kdump/kdump.txt 1938 for more details about crash dumps. 1939 1940 Usage of bzImage for capturing the crash dump is recommended as 1941 one does not have to build two kernels. Same kernel can be used 1942 as production kernel and capture kernel. Above option should have 1943 gone away after relocatable bzImage support is introduced. But it 1944 is present because there are users out there who continue to use 1945 vmlinux for dump capture. This option should go away down the 1946 line. 1947 1948 Don't change this unless you know what you are doing. 1949 1950config RELOCATABLE 1951 bool "Build a relocatable kernel" 1952 default y 1953 ---help--- 1954 This builds a kernel image that retains relocation information 1955 so it can be loaded someplace besides the default 1MB. 1956 The relocations tend to make the kernel binary about 10% larger, 1957 but are discarded at runtime. 1958 1959 One use is for the kexec on panic case where the recovery kernel 1960 must live at a different physical address than the primary 1961 kernel. 1962 1963 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1964 it has been loaded at and the compile time physical address 1965 (CONFIG_PHYSICAL_START) is used as the minimum location. 1966 1967config RANDOMIZE_BASE 1968 bool "Randomize the address of the kernel image (KASLR)" 1969 depends on RELOCATABLE 1970 default n 1971 ---help--- 1972 In support of Kernel Address Space Layout Randomization (KASLR), 1973 this randomizes the physical address at which the kernel image 1974 is decompressed and the virtual address where the kernel 1975 image is mapped, as a security feature that deters exploit 1976 attempts relying on knowledge of the location of kernel 1977 code internals. 1978 1979 On 64-bit, the kernel physical and virtual addresses are 1980 randomized separately. The physical address will be anywhere 1981 between 16MB and the top of physical memory (up to 64TB). The 1982 virtual address will be randomized from 16MB up to 1GB (9 bits 1983 of entropy). Note that this also reduces the memory space 1984 available to kernel modules from 1.5GB to 1GB. 1985 1986 On 32-bit, the kernel physical and virtual addresses are 1987 randomized together. They will be randomized from 16MB up to 1988 512MB (8 bits of entropy). 1989 1990 Entropy is generated using the RDRAND instruction if it is 1991 supported. If RDTSC is supported, its value is mixed into 1992 the entropy pool as well. If neither RDRAND nor RDTSC are 1993 supported, then entropy is read from the i8254 timer. The 1994 usable entropy is limited by the kernel being built using 1995 2GB addressing, and that PHYSICAL_ALIGN must be at a 1996 minimum of 2MB. As a result, only 10 bits of entropy are 1997 theoretically possible, but the implementations are further 1998 limited due to memory layouts. 1999 2000 If unsure, say N. 2001 2002# Relocation on x86 needs some additional build support 2003config X86_NEED_RELOCS 2004 def_bool y 2005 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2006 2007config PHYSICAL_ALIGN 2008 hex "Alignment value to which kernel should be aligned" 2009 default "0x200000" 2010 range 0x2000 0x1000000 if X86_32 2011 range 0x200000 0x1000000 if X86_64 2012 ---help--- 2013 This value puts the alignment restrictions on physical address 2014 where kernel is loaded and run from. Kernel is compiled for an 2015 address which meets above alignment restriction. 2016 2017 If bootloader loads the kernel at a non-aligned address and 2018 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2019 address aligned to above value and run from there. 2020 2021 If bootloader loads the kernel at a non-aligned address and 2022 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2023 load address and decompress itself to the address it has been 2024 compiled for and run from there. The address for which kernel is 2025 compiled already meets above alignment restrictions. Hence the 2026 end result is that kernel runs from a physical address meeting 2027 above alignment restrictions. 2028 2029 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2030 this value must be a multiple of 0x200000. 2031 2032 Don't change this unless you know what you are doing. 2033 2034config RANDOMIZE_MEMORY 2035 bool "Randomize the kernel memory sections" 2036 depends on X86_64 2037 depends on RANDOMIZE_BASE 2038 default RANDOMIZE_BASE 2039 ---help--- 2040 Randomizes the base virtual address of kernel memory sections 2041 (physical memory mapping, vmalloc & vmemmap). This security feature 2042 makes exploits relying on predictable memory locations less reliable. 2043 2044 The order of allocations remains unchanged. Entropy is generated in 2045 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2046 configuration have in average 30,000 different possible virtual 2047 addresses for each memory section. 2048 2049 If unsure, say N. 2050 2051config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2052 hex "Physical memory mapping padding" if EXPERT 2053 depends on RANDOMIZE_MEMORY 2054 default "0xa" if MEMORY_HOTPLUG 2055 default "0x0" 2056 range 0x1 0x40 if MEMORY_HOTPLUG 2057 range 0x0 0x40 2058 ---help--- 2059 Define the padding in terabytes added to the existing physical 2060 memory size during kernel memory randomization. It is useful 2061 for memory hotplug support but reduces the entropy available for 2062 address randomization. 2063 2064 If unsure, leave at the default value. 2065 2066config HOTPLUG_CPU 2067 bool "Support for hot-pluggable CPUs" 2068 depends on SMP 2069 ---help--- 2070 Say Y here to allow turning CPUs off and on. CPUs can be 2071 controlled through /sys/devices/system/cpu. 2072 ( Note: power management support will enable this option 2073 automatically on SMP systems. ) 2074 Say N if you want to disable CPU hotplug. 2075 2076config BOOTPARAM_HOTPLUG_CPU0 2077 bool "Set default setting of cpu0_hotpluggable" 2078 default n 2079 depends on HOTPLUG_CPU 2080 ---help--- 2081 Set whether default state of cpu0_hotpluggable is on or off. 2082 2083 Say Y here to enable CPU0 hotplug by default. If this switch 2084 is turned on, there is no need to give cpu0_hotplug kernel 2085 parameter and the CPU0 hotplug feature is enabled by default. 2086 2087 Please note: there are two known CPU0 dependencies if you want 2088 to enable the CPU0 hotplug feature either by this switch or by 2089 cpu0_hotplug kernel parameter. 2090 2091 First, resume from hibernate or suspend always starts from CPU0. 2092 So hibernate and suspend are prevented if CPU0 is offline. 2093 2094 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2095 offline if any interrupt can not migrate out of CPU0. There may 2096 be other CPU0 dependencies. 2097 2098 Please make sure the dependencies are under your control before 2099 you enable this feature. 2100 2101 Say N if you don't want to enable CPU0 hotplug feature by default. 2102 You still can enable the CPU0 hotplug feature at boot by kernel 2103 parameter cpu0_hotplug. 2104 2105config DEBUG_HOTPLUG_CPU0 2106 def_bool n 2107 prompt "Debug CPU0 hotplug" 2108 depends on HOTPLUG_CPU 2109 ---help--- 2110 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2111 soon as possible and boots up userspace with CPU0 offlined. User 2112 can online CPU0 back after boot time. 2113 2114 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2115 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2116 compilation or giving cpu0_hotplug kernel parameter at boot. 2117 2118 If unsure, say N. 2119 2120config COMPAT_VDSO 2121 def_bool n 2122 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2123 depends on COMPAT_32 2124 ---help--- 2125 Certain buggy versions of glibc will crash if they are 2126 presented with a 32-bit vDSO that is not mapped at the address 2127 indicated in its segment table. 2128 2129 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2130 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2131 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2132 the only released version with the bug, but OpenSUSE 9 2133 contains a buggy "glibc 2.3.2". 2134 2135 The symptom of the bug is that everything crashes on startup, saying: 2136 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2137 2138 Saying Y here changes the default value of the vdso32 boot 2139 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2140 This works around the glibc bug but hurts performance. 2141 2142 If unsure, say N: if you are compiling your own kernel, you 2143 are unlikely to be using a buggy version of glibc. 2144 2145choice 2146 prompt "vsyscall table for legacy applications" 2147 depends on X86_64 2148 default LEGACY_VSYSCALL_EMULATE 2149 help 2150 Legacy user code that does not know how to find the vDSO expects 2151 to be able to issue three syscalls by calling fixed addresses in 2152 kernel space. Since this location is not randomized with ASLR, 2153 it can be used to assist security vulnerability exploitation. 2154 2155 This setting can be changed at boot time via the kernel command 2156 line parameter vsyscall=[native|emulate|none]. 2157 2158 On a system with recent enough glibc (2.14 or newer) and no 2159 static binaries, you can say None without a performance penalty 2160 to improve security. 2161 2162 If unsure, select "Emulate". 2163 2164 config LEGACY_VSYSCALL_NATIVE 2165 bool "Native" 2166 help 2167 Actual executable code is located in the fixed vsyscall 2168 address mapping, implementing time() efficiently. Since 2169 this makes the mapping executable, it can be used during 2170 security vulnerability exploitation (traditionally as 2171 ROP gadgets). This configuration is not recommended. 2172 2173 config LEGACY_VSYSCALL_EMULATE 2174 bool "Emulate" 2175 help 2176 The kernel traps and emulates calls into the fixed 2177 vsyscall address mapping. This makes the mapping 2178 non-executable, but it still contains known contents, 2179 which could be used in certain rare security vulnerability 2180 exploits. This configuration is recommended when userspace 2181 still uses the vsyscall area. 2182 2183 config LEGACY_VSYSCALL_NONE 2184 bool "None" 2185 help 2186 There will be no vsyscall mapping at all. This will 2187 eliminate any risk of ASLR bypass due to the vsyscall 2188 fixed address mapping. Attempts to use the vsyscalls 2189 will be reported to dmesg, so that either old or 2190 malicious userspace programs can be identified. 2191 2192endchoice 2193 2194config CMDLINE_BOOL 2195 bool "Built-in kernel command line" 2196 ---help--- 2197 Allow for specifying boot arguments to the kernel at 2198 build time. On some systems (e.g. embedded ones), it is 2199 necessary or convenient to provide some or all of the 2200 kernel boot arguments with the kernel itself (that is, 2201 to not rely on the boot loader to provide them.) 2202 2203 To compile command line arguments into the kernel, 2204 set this option to 'Y', then fill in the 2205 boot arguments in CONFIG_CMDLINE. 2206 2207 Systems with fully functional boot loaders (i.e. non-embedded) 2208 should leave this option set to 'N'. 2209 2210config CMDLINE 2211 string "Built-in kernel command string" 2212 depends on CMDLINE_BOOL 2213 default "" 2214 ---help--- 2215 Enter arguments here that should be compiled into the kernel 2216 image and used at boot time. If the boot loader provides a 2217 command line at boot time, it is appended to this string to 2218 form the full kernel command line, when the system boots. 2219 2220 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2221 change this behavior. 2222 2223 In most cases, the command line (whether built-in or provided 2224 by the boot loader) should specify the device for the root 2225 file system. 2226 2227config CMDLINE_OVERRIDE 2228 bool "Built-in command line overrides boot loader arguments" 2229 depends on CMDLINE_BOOL 2230 ---help--- 2231 Set this option to 'Y' to have the kernel ignore the boot loader 2232 command line, and use ONLY the built-in command line. 2233 2234 This is used to work around broken boot loaders. This should 2235 be set to 'N' under normal conditions. 2236 2237config MODIFY_LDT_SYSCALL 2238 bool "Enable the LDT (local descriptor table)" if EXPERT 2239 default y 2240 ---help--- 2241 Linux can allow user programs to install a per-process x86 2242 Local Descriptor Table (LDT) using the modify_ldt(2) system 2243 call. This is required to run 16-bit or segmented code such as 2244 DOSEMU or some Wine programs. It is also used by some very old 2245 threading libraries. 2246 2247 Enabling this feature adds a small amount of overhead to 2248 context switches and increases the low-level kernel attack 2249 surface. Disabling it removes the modify_ldt(2) system call. 2250 2251 Saying 'N' here may make sense for embedded or server kernels. 2252 2253source "kernel/livepatch/Kconfig" 2254 2255endmenu 2256 2257config ARCH_ENABLE_MEMORY_HOTPLUG 2258 def_bool y 2259 depends on X86_64 || (X86_32 && HIGHMEM) 2260 2261config ARCH_ENABLE_MEMORY_HOTREMOVE 2262 def_bool y 2263 depends on MEMORY_HOTPLUG 2264 2265config USE_PERCPU_NUMA_NODE_ID 2266 def_bool y 2267 depends on NUMA 2268 2269config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2270 def_bool y 2271 depends on X86_64 || X86_PAE 2272 2273config ARCH_ENABLE_HUGEPAGE_MIGRATION 2274 def_bool y 2275 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2276 2277menu "Power management and ACPI options" 2278 2279config ARCH_HIBERNATION_HEADER 2280 def_bool y 2281 depends on X86_64 && HIBERNATION 2282 2283source "kernel/power/Kconfig" 2284 2285source "drivers/acpi/Kconfig" 2286 2287source "drivers/sfi/Kconfig" 2288 2289config X86_APM_BOOT 2290 def_bool y 2291 depends on APM 2292 2293menuconfig APM 2294 tristate "APM (Advanced Power Management) BIOS support" 2295 depends on X86_32 && PM_SLEEP 2296 ---help--- 2297 APM is a BIOS specification for saving power using several different 2298 techniques. This is mostly useful for battery powered laptops with 2299 APM compliant BIOSes. If you say Y here, the system time will be 2300 reset after a RESUME operation, the /proc/apm device will provide 2301 battery status information, and user-space programs will receive 2302 notification of APM "events" (e.g. battery status change). 2303 2304 If you select "Y" here, you can disable actual use of the APM 2305 BIOS by passing the "apm=off" option to the kernel at boot time. 2306 2307 Note that the APM support is almost completely disabled for 2308 machines with more than one CPU. 2309 2310 In order to use APM, you will need supporting software. For location 2311 and more information, read <file:Documentation/power/apm-acpi.txt> 2312 and the Battery Powered Linux mini-HOWTO, available from 2313 <http://www.tldp.org/docs.html#howto>. 2314 2315 This driver does not spin down disk drives (see the hdparm(8) 2316 manpage ("man 8 hdparm") for that), and it doesn't turn off 2317 VESA-compliant "green" monitors. 2318 2319 This driver does not support the TI 4000M TravelMate and the ACER 2320 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2321 desktop machines also don't have compliant BIOSes, and this driver 2322 may cause those machines to panic during the boot phase. 2323 2324 Generally, if you don't have a battery in your machine, there isn't 2325 much point in using this driver and you should say N. If you get 2326 random kernel OOPSes or reboots that don't seem to be related to 2327 anything, try disabling/enabling this option (or disabling/enabling 2328 APM in your BIOS). 2329 2330 Some other things you should try when experiencing seemingly random, 2331 "weird" problems: 2332 2333 1) make sure that you have enough swap space and that it is 2334 enabled. 2335 2) pass the "no-hlt" option to the kernel 2336 3) switch on floating point emulation in the kernel and pass 2337 the "no387" option to the kernel 2338 4) pass the "floppy=nodma" option to the kernel 2339 5) pass the "mem=4M" option to the kernel (thereby disabling 2340 all but the first 4 MB of RAM) 2341 6) make sure that the CPU is not over clocked. 2342 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2343 8) disable the cache from your BIOS settings 2344 9) install a fan for the video card or exchange video RAM 2345 10) install a better fan for the CPU 2346 11) exchange RAM chips 2347 12) exchange the motherboard. 2348 2349 To compile this driver as a module, choose M here: the 2350 module will be called apm. 2351 2352if APM 2353 2354config APM_IGNORE_USER_SUSPEND 2355 bool "Ignore USER SUSPEND" 2356 ---help--- 2357 This option will ignore USER SUSPEND requests. On machines with a 2358 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2359 series notebooks, it is necessary to say Y because of a BIOS bug. 2360 2361config APM_DO_ENABLE 2362 bool "Enable PM at boot time" 2363 ---help--- 2364 Enable APM features at boot time. From page 36 of the APM BIOS 2365 specification: "When disabled, the APM BIOS does not automatically 2366 power manage devices, enter the Standby State, enter the Suspend 2367 State, or take power saving steps in response to CPU Idle calls." 2368 This driver will make CPU Idle calls when Linux is idle (unless this 2369 feature is turned off -- see "Do CPU IDLE calls", below). This 2370 should always save battery power, but more complicated APM features 2371 will be dependent on your BIOS implementation. You may need to turn 2372 this option off if your computer hangs at boot time when using APM 2373 support, or if it beeps continuously instead of suspending. Turn 2374 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2375 T400CDT. This is off by default since most machines do fine without 2376 this feature. 2377 2378config APM_CPU_IDLE 2379 depends on CPU_IDLE 2380 bool "Make CPU Idle calls when idle" 2381 ---help--- 2382 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2383 On some machines, this can activate improved power savings, such as 2384 a slowed CPU clock rate, when the machine is idle. These idle calls 2385 are made after the idle loop has run for some length of time (e.g., 2386 333 mS). On some machines, this will cause a hang at boot time or 2387 whenever the CPU becomes idle. (On machines with more than one CPU, 2388 this option does nothing.) 2389 2390config APM_DISPLAY_BLANK 2391 bool "Enable console blanking using APM" 2392 ---help--- 2393 Enable console blanking using the APM. Some laptops can use this to 2394 turn off the LCD backlight when the screen blanker of the Linux 2395 virtual console blanks the screen. Note that this is only used by 2396 the virtual console screen blanker, and won't turn off the backlight 2397 when using the X Window system. This also doesn't have anything to 2398 do with your VESA-compliant power-saving monitor. Further, this 2399 option doesn't work for all laptops -- it might not turn off your 2400 backlight at all, or it might print a lot of errors to the console, 2401 especially if you are using gpm. 2402 2403config APM_ALLOW_INTS 2404 bool "Allow interrupts during APM BIOS calls" 2405 ---help--- 2406 Normally we disable external interrupts while we are making calls to 2407 the APM BIOS as a measure to lessen the effects of a badly behaving 2408 BIOS implementation. The BIOS should reenable interrupts if it 2409 needs to. Unfortunately, some BIOSes do not -- especially those in 2410 many of the newer IBM Thinkpads. If you experience hangs when you 2411 suspend, try setting this to Y. Otherwise, say N. 2412 2413endif # APM 2414 2415source "drivers/cpufreq/Kconfig" 2416 2417source "drivers/cpuidle/Kconfig" 2418 2419source "drivers/idle/Kconfig" 2420 2421endmenu 2422 2423 2424menu "Bus options (PCI etc.)" 2425 2426config PCI 2427 bool "PCI support" 2428 default y 2429 ---help--- 2430 Find out whether you have a PCI motherboard. PCI is the name of a 2431 bus system, i.e. the way the CPU talks to the other stuff inside 2432 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2433 VESA. If you have PCI, say Y, otherwise N. 2434 2435choice 2436 prompt "PCI access mode" 2437 depends on X86_32 && PCI 2438 default PCI_GOANY 2439 ---help--- 2440 On PCI systems, the BIOS can be used to detect the PCI devices and 2441 determine their configuration. However, some old PCI motherboards 2442 have BIOS bugs and may crash if this is done. Also, some embedded 2443 PCI-based systems don't have any BIOS at all. Linux can also try to 2444 detect the PCI hardware directly without using the BIOS. 2445 2446 With this option, you can specify how Linux should detect the 2447 PCI devices. If you choose "BIOS", the BIOS will be used, 2448 if you choose "Direct", the BIOS won't be used, and if you 2449 choose "MMConfig", then PCI Express MMCONFIG will be used. 2450 If you choose "Any", the kernel will try MMCONFIG, then the 2451 direct access method and falls back to the BIOS if that doesn't 2452 work. If unsure, go with the default, which is "Any". 2453 2454config PCI_GOBIOS 2455 bool "BIOS" 2456 2457config PCI_GOMMCONFIG 2458 bool "MMConfig" 2459 2460config PCI_GODIRECT 2461 bool "Direct" 2462 2463config PCI_GOOLPC 2464 bool "OLPC XO-1" 2465 depends on OLPC 2466 2467config PCI_GOANY 2468 bool "Any" 2469 2470endchoice 2471 2472config PCI_BIOS 2473 def_bool y 2474 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2475 2476# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2477config PCI_DIRECT 2478 def_bool y 2479 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2480 2481config PCI_MMCONFIG 2482 def_bool y 2483 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2484 2485config PCI_OLPC 2486 def_bool y 2487 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2488 2489config PCI_XEN 2490 def_bool y 2491 depends on PCI && XEN 2492 select SWIOTLB_XEN 2493 2494config PCI_DOMAINS 2495 def_bool y 2496 depends on PCI 2497 2498config PCI_MMCONFIG 2499 bool "Support mmconfig PCI config space access" 2500 depends on X86_64 && PCI && ACPI 2501 2502config PCI_CNB20LE_QUIRK 2503 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2504 depends on PCI 2505 help 2506 Read the PCI windows out of the CNB20LE host bridge. This allows 2507 PCI hotplug to work on systems with the CNB20LE chipset which do 2508 not have ACPI. 2509 2510 There's no public spec for this chipset, and this functionality 2511 is known to be incomplete. 2512 2513 You should say N unless you know you need this. 2514 2515source "drivers/pci/Kconfig" 2516 2517config ISA_BUS 2518 bool "ISA-style bus support on modern systems" if EXPERT 2519 select ISA_BUS_API 2520 help 2521 Enables ISA-style drivers on modern systems. This is necessary to 2522 support PC/104 devices on X86_64 platforms. 2523 2524 If unsure, say N. 2525 2526# x86_64 have no ISA slots, but can have ISA-style DMA. 2527config ISA_DMA_API 2528 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2529 default y 2530 help 2531 Enables ISA-style DMA support for devices requiring such controllers. 2532 If unsure, say Y. 2533 2534if X86_32 2535 2536config ISA 2537 bool "ISA support" 2538 ---help--- 2539 Find out whether you have ISA slots on your motherboard. ISA is the 2540 name of a bus system, i.e. the way the CPU talks to the other stuff 2541 inside your box. Other bus systems are PCI, EISA, MicroChannel 2542 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2543 newer boards don't support it. If you have ISA, say Y, otherwise N. 2544 2545config EISA 2546 bool "EISA support" 2547 depends on ISA 2548 ---help--- 2549 The Extended Industry Standard Architecture (EISA) bus was 2550 developed as an open alternative to the IBM MicroChannel bus. 2551 2552 The EISA bus provided some of the features of the IBM MicroChannel 2553 bus while maintaining backward compatibility with cards made for 2554 the older ISA bus. The EISA bus saw limited use between 1988 and 2555 1995 when it was made obsolete by the PCI bus. 2556 2557 Say Y here if you are building a kernel for an EISA-based machine. 2558 2559 Otherwise, say N. 2560 2561source "drivers/eisa/Kconfig" 2562 2563config SCx200 2564 tristate "NatSemi SCx200 support" 2565 ---help--- 2566 This provides basic support for National Semiconductor's 2567 (now AMD's) Geode processors. The driver probes for the 2568 PCI-IDs of several on-chip devices, so its a good dependency 2569 for other scx200_* drivers. 2570 2571 If compiled as a module, the driver is named scx200. 2572 2573config SCx200HR_TIMER 2574 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2575 depends on SCx200 2576 default y 2577 ---help--- 2578 This driver provides a clocksource built upon the on-chip 2579 27MHz high-resolution timer. Its also a workaround for 2580 NSC Geode SC-1100's buggy TSC, which loses time when the 2581 processor goes idle (as is done by the scheduler). The 2582 other workaround is idle=poll boot option. 2583 2584config OLPC 2585 bool "One Laptop Per Child support" 2586 depends on !X86_PAE 2587 select GPIOLIB 2588 select OF 2589 select OF_PROMTREE 2590 select IRQ_DOMAIN 2591 ---help--- 2592 Add support for detecting the unique features of the OLPC 2593 XO hardware. 2594 2595config OLPC_XO1_PM 2596 bool "OLPC XO-1 Power Management" 2597 depends on OLPC && MFD_CS5535 && PM_SLEEP 2598 select MFD_CORE 2599 ---help--- 2600 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2601 2602config OLPC_XO1_RTC 2603 bool "OLPC XO-1 Real Time Clock" 2604 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2605 ---help--- 2606 Add support for the XO-1 real time clock, which can be used as a 2607 programmable wakeup source. 2608 2609config OLPC_XO1_SCI 2610 bool "OLPC XO-1 SCI extras" 2611 depends on OLPC && OLPC_XO1_PM 2612 depends on INPUT=y 2613 select POWER_SUPPLY 2614 select GPIO_CS5535 2615 select MFD_CORE 2616 ---help--- 2617 Add support for SCI-based features of the OLPC XO-1 laptop: 2618 - EC-driven system wakeups 2619 - Power button 2620 - Ebook switch 2621 - Lid switch 2622 - AC adapter status updates 2623 - Battery status updates 2624 2625config OLPC_XO15_SCI 2626 bool "OLPC XO-1.5 SCI extras" 2627 depends on OLPC && ACPI 2628 select POWER_SUPPLY 2629 ---help--- 2630 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2631 - EC-driven system wakeups 2632 - AC adapter status updates 2633 - Battery status updates 2634 2635config ALIX 2636 bool "PCEngines ALIX System Support (LED setup)" 2637 select GPIOLIB 2638 ---help--- 2639 This option enables system support for the PCEngines ALIX. 2640 At present this just sets up LEDs for GPIO control on 2641 ALIX2/3/6 boards. However, other system specific setup should 2642 get added here. 2643 2644 Note: You must still enable the drivers for GPIO and LED support 2645 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2646 2647 Note: You have to set alix.force=1 for boards with Award BIOS. 2648 2649config NET5501 2650 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2651 select GPIOLIB 2652 ---help--- 2653 This option enables system support for the Soekris Engineering net5501. 2654 2655config GEOS 2656 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2657 select GPIOLIB 2658 depends on DMI 2659 ---help--- 2660 This option enables system support for the Traverse Technologies GEOS. 2661 2662config TS5500 2663 bool "Technologic Systems TS-5500 platform support" 2664 depends on MELAN 2665 select CHECK_SIGNATURE 2666 select NEW_LEDS 2667 select LEDS_CLASS 2668 ---help--- 2669 This option enables system support for the Technologic Systems TS-5500. 2670 2671endif # X86_32 2672 2673config AMD_NB 2674 def_bool y 2675 depends on CPU_SUP_AMD && PCI 2676 2677source "drivers/pcmcia/Kconfig" 2678 2679config RAPIDIO 2680 tristate "RapidIO support" 2681 depends on PCI 2682 default n 2683 help 2684 If enabled this option will include drivers and the core 2685 infrastructure code to support RapidIO interconnect devices. 2686 2687source "drivers/rapidio/Kconfig" 2688 2689config X86_SYSFB 2690 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2691 help 2692 Firmwares often provide initial graphics framebuffers so the BIOS, 2693 bootloader or kernel can show basic video-output during boot for 2694 user-guidance and debugging. Historically, x86 used the VESA BIOS 2695 Extensions and EFI-framebuffers for this, which are mostly limited 2696 to x86. 2697 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2698 framebuffers so the new generic system-framebuffer drivers can be 2699 used on x86. If the framebuffer is not compatible with the generic 2700 modes, it is adverticed as fallback platform framebuffer so legacy 2701 drivers like efifb, vesafb and uvesafb can pick it up. 2702 If this option is not selected, all system framebuffers are always 2703 marked as fallback platform framebuffers as usual. 2704 2705 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2706 not be able to pick up generic system framebuffers if this option 2707 is selected. You are highly encouraged to enable simplefb as 2708 replacement if you select this option. simplefb can correctly deal 2709 with generic system framebuffers. But you should still keep vesafb 2710 and others enabled as fallback if a system framebuffer is 2711 incompatible with simplefb. 2712 2713 If unsure, say Y. 2714 2715endmenu 2716 2717 2718menu "Executable file formats / Emulations" 2719 2720source "fs/Kconfig.binfmt" 2721 2722config IA32_EMULATION 2723 bool "IA32 Emulation" 2724 depends on X86_64 2725 select ARCH_WANT_OLD_COMPAT_IPC 2726 select BINFMT_ELF 2727 select COMPAT_BINFMT_ELF 2728 select COMPAT_OLD_SIGACTION 2729 ---help--- 2730 Include code to run legacy 32-bit programs under a 2731 64-bit kernel. You should likely turn this on, unless you're 2732 100% sure that you don't have any 32-bit programs left. 2733 2734config IA32_AOUT 2735 tristate "IA32 a.out support" 2736 depends on IA32_EMULATION 2737 ---help--- 2738 Support old a.out binaries in the 32bit emulation. 2739 2740config X86_X32 2741 bool "x32 ABI for 64-bit mode" 2742 depends on X86_64 2743 ---help--- 2744 Include code to run binaries for the x32 native 32-bit ABI 2745 for 64-bit processors. An x32 process gets access to the 2746 full 64-bit register file and wide data path while leaving 2747 pointers at 32 bits for smaller memory footprint. 2748 2749 You will need a recent binutils (2.22 or later) with 2750 elf32_x86_64 support enabled to compile a kernel with this 2751 option set. 2752 2753config COMPAT_32 2754 def_bool y 2755 depends on IA32_EMULATION || X86_32 2756 select HAVE_UID16 2757 select OLD_SIGSUSPEND3 2758 2759config COMPAT 2760 def_bool y 2761 depends on IA32_EMULATION || X86_X32 2762 2763if COMPAT 2764config COMPAT_FOR_U64_ALIGNMENT 2765 def_bool y 2766 2767config SYSVIPC_COMPAT 2768 def_bool y 2769 depends on SYSVIPC 2770 2771config KEYS_COMPAT 2772 def_bool y 2773 depends on KEYS 2774endif 2775 2776endmenu 2777 2778 2779config HAVE_ATOMIC_IOMAP 2780 def_bool y 2781 depends on X86_32 2782 2783config X86_DEV_DMA_OPS 2784 bool 2785 depends on X86_64 || STA2X11 2786 2787config X86_DMA_REMAP 2788 bool 2789 depends on STA2X11 2790 2791source "net/Kconfig" 2792 2793source "drivers/Kconfig" 2794 2795source "drivers/firmware/Kconfig" 2796 2797source "fs/Kconfig" 2798 2799source "arch/x86/Kconfig.debug" 2800 2801source "security/Kconfig" 2802 2803source "crypto/Kconfig" 2804 2805source "arch/x86/kvm/Kconfig" 2806 2807source "lib/Kconfig" 2808