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 13config X86_64 14 def_bool y 15 depends on 64BIT 16 17### Arch settings 18config X86 19 def_bool y 20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 22 select ANON_INODES 23 select ARCH_CLOCKSOURCE_DATA 24 select ARCH_DISCARD_MEMBLOCK 25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 27 select ARCH_HAS_ELF_RANDOMIZE 28 select ARCH_HAS_FAST_MULTIPLIER 29 select ARCH_HAS_GCOV_PROFILE_ALL 30 select ARCH_HAS_PMEM_API 31 select ARCH_HAS_SG_CHAIN 32 select ARCH_HAVE_NMI_SAFE_CMPXCHG 33 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 34 select ARCH_MIGHT_HAVE_PC_PARPORT 35 select ARCH_MIGHT_HAVE_PC_SERIO 36 select ARCH_SUPPORTS_ATOMIC_RMW 37 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT 38 select ARCH_SUPPORTS_INT128 if X86_64 39 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 40 select ARCH_USE_BUILTIN_BSWAP 41 select ARCH_USE_CMPXCHG_LOCKREF if X86_64 42 select ARCH_USE_QUEUED_RWLOCKS 43 select ARCH_USE_QUEUED_SPINLOCKS 44 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP 45 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 46 select ARCH_WANT_FRAME_POINTERS 47 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 48 select ARCH_WANT_OPTIONAL_GPIOLIB 49 select BUILDTIME_EXTABLE_SORT 50 select CLKEVT_I8253 51 select CLKSRC_I8253 if X86_32 52 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 53 select CLOCKSOURCE_WATCHDOG 54 select CLONE_BACKWARDS if X86_32 55 select COMPAT_OLD_SIGACTION if IA32_EMULATION 56 select DCACHE_WORD_ACCESS 57 select EDAC_ATOMIC_SCRUB 58 select EDAC_SUPPORT 59 select GENERIC_CLOCKEVENTS 60 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 61 select GENERIC_CLOCKEVENTS_MIN_ADJUST 62 select GENERIC_CMOS_UPDATE 63 select GENERIC_CPU_AUTOPROBE 64 select GENERIC_EARLY_IOREMAP 65 select GENERIC_FIND_FIRST_BIT 66 select GENERIC_IOMAP 67 select GENERIC_IRQ_PROBE 68 select GENERIC_IRQ_SHOW 69 select GENERIC_PENDING_IRQ if SMP 70 select GENERIC_SMP_IDLE_THREAD 71 select GENERIC_STRNCPY_FROM_USER 72 select GENERIC_STRNLEN_USER 73 select GENERIC_TIME_VSYSCALL 74 select HAVE_ACPI_APEI if ACPI 75 select HAVE_ACPI_APEI_NMI if ACPI 76 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 77 select HAVE_AOUT if X86_32 78 select HAVE_ARCH_AUDITSYSCALL 79 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 80 select HAVE_ARCH_JUMP_LABEL 81 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP 82 select HAVE_ARCH_KGDB 83 select HAVE_ARCH_KMEMCHECK 84 select HAVE_ARCH_SECCOMP_FILTER 85 select HAVE_ARCH_SOFT_DIRTY if X86_64 86 select HAVE_ARCH_TRACEHOOK 87 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 88 select HAVE_BPF_JIT if X86_64 89 select HAVE_CC_STACKPROTECTOR 90 select HAVE_CMPXCHG_DOUBLE 91 select HAVE_CMPXCHG_LOCAL 92 select HAVE_CONTEXT_TRACKING if X86_64 93 select HAVE_COPY_THREAD_TLS 94 select HAVE_C_RECORDMCOUNT 95 select HAVE_DEBUG_KMEMLEAK 96 select HAVE_DEBUG_STACKOVERFLOW 97 select HAVE_DMA_API_DEBUG 98 select HAVE_DMA_ATTRS 99 select HAVE_DMA_CONTIGUOUS 100 select HAVE_DYNAMIC_FTRACE 101 select HAVE_DYNAMIC_FTRACE_WITH_REGS 102 select HAVE_EFFICIENT_UNALIGNED_ACCESS 103 select HAVE_FENTRY if X86_64 104 select HAVE_FTRACE_MCOUNT_RECORD 105 select HAVE_FUNCTION_GRAPH_FP_TEST 106 select HAVE_FUNCTION_GRAPH_TRACER 107 select HAVE_FUNCTION_TRACER 108 select HAVE_GENERIC_DMA_COHERENT if X86_32 109 select HAVE_HW_BREAKPOINT 110 select HAVE_IDE 111 select HAVE_IOREMAP_PROT 112 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 113 select HAVE_IRQ_TIME_ACCOUNTING 114 select HAVE_KERNEL_BZIP2 115 select HAVE_KERNEL_GZIP 116 select HAVE_KERNEL_LZ4 117 select HAVE_KERNEL_LZMA 118 select HAVE_KERNEL_LZO 119 select HAVE_KERNEL_XZ 120 select HAVE_KPROBES 121 select HAVE_KPROBES_ON_FTRACE 122 select HAVE_KRETPROBES 123 select HAVE_KVM 124 select HAVE_LIVEPATCH if X86_64 125 select HAVE_MEMBLOCK 126 select HAVE_MEMBLOCK_NODE_MAP 127 select HAVE_MIXED_BREAKPOINTS_REGS 128 select HAVE_OPROFILE 129 select HAVE_OPTPROBES 130 select HAVE_PCSPKR_PLATFORM 131 select HAVE_PERF_EVENTS 132 select HAVE_PERF_EVENTS_NMI 133 select HAVE_PERF_REGS 134 select HAVE_PERF_USER_STACK_DUMP 135 select HAVE_REGS_AND_STACK_ACCESS_API 136 select HAVE_SYSCALL_TRACEPOINTS 137 select HAVE_UID16 if X86_32 || IA32_EMULATION 138 select HAVE_UNSTABLE_SCHED_CLOCK 139 select HAVE_USER_RETURN_NOTIFIER 140 select IRQ_FORCED_THREADING 141 select MODULES_USE_ELF_RELA if X86_64 142 select MODULES_USE_ELF_REL if X86_32 143 select OLD_SIGACTION if X86_32 144 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 145 select PERF_EVENTS 146 select RTC_LIB 147 select SPARSE_IRQ 148 select SRCU 149 select SYSCTL_EXCEPTION_TRACE 150 select USER_STACKTRACE_SUPPORT 151 select VIRT_TO_BUS 152 select X86_DEV_DMA_OPS if X86_64 153 select X86_FEATURE_NAMES if PROC_FS 154 155config INSTRUCTION_DECODER 156 def_bool y 157 depends on KPROBES || PERF_EVENTS || UPROBES 158 159config PERF_EVENTS_INTEL_UNCORE 160 def_bool y 161 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI 162 163config OUTPUT_FORMAT 164 string 165 default "elf32-i386" if X86_32 166 default "elf64-x86-64" if X86_64 167 168config ARCH_DEFCONFIG 169 string 170 default "arch/x86/configs/i386_defconfig" if X86_32 171 default "arch/x86/configs/x86_64_defconfig" if X86_64 172 173config LOCKDEP_SUPPORT 174 def_bool y 175 176config STACKTRACE_SUPPORT 177 def_bool y 178 179config HAVE_LATENCYTOP_SUPPORT 180 def_bool y 181 182config MMU 183 def_bool y 184 185config SBUS 186 bool 187 188config NEED_DMA_MAP_STATE 189 def_bool y 190 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB 191 192config NEED_SG_DMA_LENGTH 193 def_bool y 194 195config GENERIC_ISA_DMA 196 def_bool y 197 depends on ISA_DMA_API 198 199config GENERIC_BUG 200 def_bool y 201 depends on BUG 202 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 203 204config GENERIC_BUG_RELATIVE_POINTERS 205 bool 206 207config GENERIC_HWEIGHT 208 def_bool y 209 210config ARCH_MAY_HAVE_PC_FDC 211 def_bool y 212 depends on ISA_DMA_API 213 214config RWSEM_XCHGADD_ALGORITHM 215 def_bool y 216 217config GENERIC_CALIBRATE_DELAY 218 def_bool y 219 220config ARCH_HAS_CPU_RELAX 221 def_bool y 222 223config ARCH_HAS_CACHE_LINE_SIZE 224 def_bool y 225 226config HAVE_SETUP_PER_CPU_AREA 227 def_bool y 228 229config NEED_PER_CPU_EMBED_FIRST_CHUNK 230 def_bool y 231 232config NEED_PER_CPU_PAGE_FIRST_CHUNK 233 def_bool y 234 235config ARCH_HIBERNATION_POSSIBLE 236 def_bool y 237 238config ARCH_SUSPEND_POSSIBLE 239 def_bool y 240 241config ARCH_WANT_HUGE_PMD_SHARE 242 def_bool y 243 244config ARCH_WANT_GENERAL_HUGETLB 245 def_bool y 246 247config ZONE_DMA32 248 def_bool y if X86_64 249 250config AUDIT_ARCH 251 def_bool y if X86_64 252 253config ARCH_SUPPORTS_OPTIMIZED_INLINING 254 def_bool y 255 256config ARCH_SUPPORTS_DEBUG_PAGEALLOC 257 def_bool y 258 259config KASAN_SHADOW_OFFSET 260 hex 261 depends on KASAN 262 default 0xdffffc0000000000 263 264config HAVE_INTEL_TXT 265 def_bool y 266 depends on INTEL_IOMMU && ACPI 267 268config X86_32_SMP 269 def_bool y 270 depends on X86_32 && SMP 271 272config X86_64_SMP 273 def_bool y 274 depends on X86_64 && SMP 275 276config X86_32_LAZY_GS 277 def_bool y 278 depends on X86_32 && !CC_STACKPROTECTOR 279 280config ARCH_HWEIGHT_CFLAGS 281 string 282 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 283 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 284 285config ARCH_SUPPORTS_UPROBES 286 def_bool y 287 288config FIX_EARLYCON_MEM 289 def_bool y 290 291config PGTABLE_LEVELS 292 int 293 default 4 if X86_64 294 default 3 if X86_PAE 295 default 2 296 297source "init/Kconfig" 298source "kernel/Kconfig.freezer" 299 300menu "Processor type and features" 301 302config ZONE_DMA 303 bool "DMA memory allocation support" if EXPERT 304 default y 305 help 306 DMA memory allocation support allows devices with less than 32-bit 307 addressing to allocate within the first 16MB of address space. 308 Disable if no such devices will be used. 309 310 If unsure, say Y. 311 312config SMP 313 bool "Symmetric multi-processing support" 314 ---help--- 315 This enables support for systems with more than one CPU. If you have 316 a system with only one CPU, say N. If you have a system with more 317 than one CPU, say Y. 318 319 If you say N here, the kernel will run on uni- and multiprocessor 320 machines, but will use only one CPU of a multiprocessor machine. If 321 you say Y here, the kernel will run on many, but not all, 322 uniprocessor machines. On a uniprocessor machine, the kernel 323 will run faster if you say N here. 324 325 Note that if you say Y here and choose architecture "586" or 326 "Pentium" under "Processor family", the kernel will not work on 486 327 architectures. Similarly, multiprocessor kernels for the "PPro" 328 architecture may not work on all Pentium based boards. 329 330 People using multiprocessor machines who say Y here should also say 331 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 332 Management" code will be disabled if you say Y here. 333 334 See also <file:Documentation/x86/i386/IO-APIC.txt>, 335 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 336 <http://www.tldp.org/docs.html#howto>. 337 338 If you don't know what to do here, say N. 339 340config X86_FEATURE_NAMES 341 bool "Processor feature human-readable names" if EMBEDDED 342 default y 343 ---help--- 344 This option compiles in a table of x86 feature bits and corresponding 345 names. This is required to support /proc/cpuinfo and a few kernel 346 messages. You can disable this to save space, at the expense of 347 making those few kernel messages show numeric feature bits instead. 348 349 If in doubt, say Y. 350 351config X86_X2APIC 352 bool "Support x2apic" 353 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 354 ---help--- 355 This enables x2apic support on CPUs that have this feature. 356 357 This allows 32-bit apic IDs (so it can support very large systems), 358 and accesses the local apic via MSRs not via mmio. 359 360 If you don't know what to do here, say N. 361 362config X86_MPPARSE 363 bool "Enable MPS table" if ACPI || SFI 364 default y 365 depends on X86_LOCAL_APIC 366 ---help--- 367 For old smp systems that do not have proper acpi support. Newer systems 368 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 369 370config X86_BIGSMP 371 bool "Support for big SMP systems with more than 8 CPUs" 372 depends on X86_32 && SMP 373 ---help--- 374 This option is needed for the systems that have more than 8 CPUs 375 376config GOLDFISH 377 def_bool y 378 depends on X86_GOLDFISH 379 380if X86_32 381config X86_EXTENDED_PLATFORM 382 bool "Support for extended (non-PC) x86 platforms" 383 default y 384 ---help--- 385 If you disable this option then the kernel will only support 386 standard PC platforms. (which covers the vast majority of 387 systems out there.) 388 389 If you enable this option then you'll be able to select support 390 for the following (non-PC) 32 bit x86 platforms: 391 Goldfish (Android emulator) 392 AMD Elan 393 RDC R-321x SoC 394 SGI 320/540 (Visual Workstation) 395 STA2X11-based (e.g. Northville) 396 Moorestown MID devices 397 398 If you have one of these systems, or if you want to build a 399 generic distribution kernel, say Y here - otherwise say N. 400endif 401 402if X86_64 403config X86_EXTENDED_PLATFORM 404 bool "Support for extended (non-PC) x86 platforms" 405 default y 406 ---help--- 407 If you disable this option then the kernel will only support 408 standard PC platforms. (which covers the vast majority of 409 systems out there.) 410 411 If you enable this option then you'll be able to select support 412 for the following (non-PC) 64 bit x86 platforms: 413 Numascale NumaChip 414 ScaleMP vSMP 415 SGI Ultraviolet 416 417 If you have one of these systems, or if you want to build a 418 generic distribution kernel, say Y here - otherwise say N. 419endif 420# This is an alphabetically sorted list of 64 bit extended platforms 421# Please maintain the alphabetic order if and when there are additions 422config X86_NUMACHIP 423 bool "Numascale NumaChip" 424 depends on X86_64 425 depends on X86_EXTENDED_PLATFORM 426 depends on NUMA 427 depends on SMP 428 depends on X86_X2APIC 429 depends on PCI_MMCONFIG 430 ---help--- 431 Adds support for Numascale NumaChip large-SMP systems. Needed to 432 enable more than ~168 cores. 433 If you don't have one of these, you should say N here. 434 435config X86_VSMP 436 bool "ScaleMP vSMP" 437 select HYPERVISOR_GUEST 438 select PARAVIRT 439 depends on X86_64 && PCI 440 depends on X86_EXTENDED_PLATFORM 441 depends on SMP 442 ---help--- 443 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 444 supposed to run on these EM64T-based machines. Only choose this option 445 if you have one of these machines. 446 447config X86_UV 448 bool "SGI Ultraviolet" 449 depends on X86_64 450 depends on X86_EXTENDED_PLATFORM 451 depends on NUMA 452 depends on X86_X2APIC 453 depends on PCI 454 ---help--- 455 This option is needed in order to support SGI Ultraviolet systems. 456 If you don't have one of these, you should say N here. 457 458# Following is an alphabetically sorted list of 32 bit extended platforms 459# Please maintain the alphabetic order if and when there are additions 460 461config X86_GOLDFISH 462 bool "Goldfish (Virtual Platform)" 463 depends on X86_EXTENDED_PLATFORM 464 ---help--- 465 Enable support for the Goldfish virtual platform used primarily 466 for Android development. Unless you are building for the Android 467 Goldfish emulator say N here. 468 469config X86_INTEL_CE 470 bool "CE4100 TV platform" 471 depends on PCI 472 depends on PCI_GODIRECT 473 depends on X86_IO_APIC 474 depends on X86_32 475 depends on X86_EXTENDED_PLATFORM 476 select X86_REBOOTFIXUPS 477 select OF 478 select OF_EARLY_FLATTREE 479 ---help--- 480 Select for the Intel CE media processor (CE4100) SOC. 481 This option compiles in support for the CE4100 SOC for settop 482 boxes and media devices. 483 484config X86_INTEL_MID 485 bool "Intel MID platform support" 486 depends on X86_32 487 depends on X86_EXTENDED_PLATFORM 488 depends on X86_PLATFORM_DEVICES 489 depends on PCI 490 depends on PCI_GOANY 491 depends on X86_IO_APIC 492 select SFI 493 select I2C 494 select DW_APB_TIMER 495 select APB_TIMER 496 select INTEL_SCU_IPC 497 select MFD_INTEL_MSIC 498 ---help--- 499 Select to build a kernel capable of supporting Intel MID (Mobile 500 Internet Device) platform systems which do not have the PCI legacy 501 interfaces. If you are building for a PC class system say N here. 502 503 Intel MID platforms are based on an Intel processor and chipset which 504 consume less power than most of the x86 derivatives. 505 506config X86_INTEL_QUARK 507 bool "Intel Quark platform support" 508 depends on X86_32 509 depends on X86_EXTENDED_PLATFORM 510 depends on X86_PLATFORM_DEVICES 511 depends on X86_TSC 512 depends on PCI 513 depends on PCI_GOANY 514 depends on X86_IO_APIC 515 select IOSF_MBI 516 select INTEL_IMR 517 select COMMON_CLK 518 ---help--- 519 Select to include support for Quark X1000 SoC. 520 Say Y here if you have a Quark based system such as the Arduino 521 compatible Intel Galileo. 522 523config X86_INTEL_LPSS 524 bool "Intel Low Power Subsystem Support" 525 depends on ACPI 526 select COMMON_CLK 527 select PINCTRL 528 ---help--- 529 Select to build support for Intel Low Power Subsystem such as 530 found on Intel Lynxpoint PCH. Selecting this option enables 531 things like clock tree (common clock framework) and pincontrol 532 which are needed by the LPSS peripheral drivers. 533 534config X86_AMD_PLATFORM_DEVICE 535 bool "AMD ACPI2Platform devices support" 536 depends on ACPI 537 select COMMON_CLK 538 select PINCTRL 539 ---help--- 540 Select to interpret AMD specific ACPI device to platform device 541 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 542 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 543 implemented under PINCTRL subsystem. 544 545config IOSF_MBI 546 tristate "Intel SoC IOSF Sideband support for SoC platforms" 547 depends on PCI 548 ---help--- 549 This option enables sideband register access support for Intel SoC 550 platforms. On these platforms the IOSF sideband is used in lieu of 551 MSR's for some register accesses, mostly but not limited to thermal 552 and power. Drivers may query the availability of this device to 553 determine if they need the sideband in order to work on these 554 platforms. The sideband is available on the following SoC products. 555 This list is not meant to be exclusive. 556 - BayTrail 557 - Braswell 558 - Quark 559 560 You should say Y if you are running a kernel on one of these SoC's. 561 562config IOSF_MBI_DEBUG 563 bool "Enable IOSF sideband access through debugfs" 564 depends on IOSF_MBI && DEBUG_FS 565 ---help--- 566 Select this option to expose the IOSF sideband access registers (MCR, 567 MDR, MCRX) through debugfs to write and read register information from 568 different units on the SoC. This is most useful for obtaining device 569 state information for debug and analysis. As this is a general access 570 mechanism, users of this option would have specific knowledge of the 571 device they want to access. 572 573 If you don't require the option or are in doubt, say N. 574 575config X86_RDC321X 576 bool "RDC R-321x SoC" 577 depends on X86_32 578 depends on X86_EXTENDED_PLATFORM 579 select M486 580 select X86_REBOOTFIXUPS 581 ---help--- 582 This option is needed for RDC R-321x system-on-chip, also known 583 as R-8610-(G). 584 If you don't have one of these chips, you should say N here. 585 586config X86_32_NON_STANDARD 587 bool "Support non-standard 32-bit SMP architectures" 588 depends on X86_32 && SMP 589 depends on X86_EXTENDED_PLATFORM 590 ---help--- 591 This option compiles in the bigsmp and STA2X11 default 592 subarchitectures. It is intended for a generic binary 593 kernel. If you select them all, kernel will probe it one by 594 one and will fallback to default. 595 596# Alphabetically sorted list of Non standard 32 bit platforms 597 598config X86_SUPPORTS_MEMORY_FAILURE 599 def_bool y 600 # MCE code calls memory_failure(): 601 depends on X86_MCE 602 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 603 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 604 depends on X86_64 || !SPARSEMEM 605 select ARCH_SUPPORTS_MEMORY_FAILURE 606 607config STA2X11 608 bool "STA2X11 Companion Chip Support" 609 depends on X86_32_NON_STANDARD && PCI 610 select X86_DEV_DMA_OPS 611 select X86_DMA_REMAP 612 select SWIOTLB 613 select MFD_STA2X11 614 select ARCH_REQUIRE_GPIOLIB 615 default n 616 ---help--- 617 This adds support for boards based on the STA2X11 IO-Hub, 618 a.k.a. "ConneXt". The chip is used in place of the standard 619 PC chipset, so all "standard" peripherals are missing. If this 620 option is selected the kernel will still be able to boot on 621 standard PC machines. 622 623config X86_32_IRIS 624 tristate "Eurobraille/Iris poweroff module" 625 depends on X86_32 626 ---help--- 627 The Iris machines from EuroBraille do not have APM or ACPI support 628 to shut themselves down properly. A special I/O sequence is 629 needed to do so, which is what this module does at 630 kernel shutdown. 631 632 This is only for Iris machines from EuroBraille. 633 634 If unused, say N. 635 636config SCHED_OMIT_FRAME_POINTER 637 def_bool y 638 prompt "Single-depth WCHAN output" 639 depends on X86 640 ---help--- 641 Calculate simpler /proc/<PID>/wchan values. If this option 642 is disabled then wchan values will recurse back to the 643 caller function. This provides more accurate wchan values, 644 at the expense of slightly more scheduling overhead. 645 646 If in doubt, say "Y". 647 648menuconfig HYPERVISOR_GUEST 649 bool "Linux guest support" 650 ---help--- 651 Say Y here to enable options for running Linux under various hyper- 652 visors. This option enables basic hypervisor detection and platform 653 setup. 654 655 If you say N, all options in this submenu will be skipped and 656 disabled, and Linux guest support won't be built in. 657 658if HYPERVISOR_GUEST 659 660config PARAVIRT 661 bool "Enable paravirtualization code" 662 ---help--- 663 This changes the kernel so it can modify itself when it is run 664 under a hypervisor, potentially improving performance significantly 665 over full virtualization. However, when run without a hypervisor 666 the kernel is theoretically slower and slightly larger. 667 668config PARAVIRT_DEBUG 669 bool "paravirt-ops debugging" 670 depends on PARAVIRT && DEBUG_KERNEL 671 ---help--- 672 Enable to debug paravirt_ops internals. Specifically, BUG if 673 a paravirt_op is missing when it is called. 674 675config PARAVIRT_SPINLOCKS 676 bool "Paravirtualization layer for spinlocks" 677 depends on PARAVIRT && SMP 678 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS 679 ---help--- 680 Paravirtualized spinlocks allow a pvops backend to replace the 681 spinlock implementation with something virtualization-friendly 682 (for example, block the virtual CPU rather than spinning). 683 684 It has a minimal impact on native kernels and gives a nice performance 685 benefit on paravirtualized KVM / Xen kernels. 686 687 If you are unsure how to answer this question, answer Y. 688 689source "arch/x86/xen/Kconfig" 690 691config KVM_GUEST 692 bool "KVM Guest support (including kvmclock)" 693 depends on PARAVIRT 694 select PARAVIRT_CLOCK 695 default y 696 ---help--- 697 This option enables various optimizations for running under the KVM 698 hypervisor. It includes a paravirtualized clock, so that instead 699 of relying on a PIT (or probably other) emulation by the 700 underlying device model, the host provides the guest with 701 timing infrastructure such as time of day, and system time 702 703config KVM_DEBUG_FS 704 bool "Enable debug information for KVM Guests in debugfs" 705 depends on KVM_GUEST && DEBUG_FS 706 default n 707 ---help--- 708 This option enables collection of various statistics for KVM guest. 709 Statistics are displayed in debugfs filesystem. Enabling this option 710 may incur significant overhead. 711 712source "arch/x86/lguest/Kconfig" 713 714config PARAVIRT_TIME_ACCOUNTING 715 bool "Paravirtual steal time accounting" 716 depends on PARAVIRT 717 default n 718 ---help--- 719 Select this option to enable fine granularity task steal time 720 accounting. Time spent executing other tasks in parallel with 721 the current vCPU is discounted from the vCPU power. To account for 722 that, there can be a small performance impact. 723 724 If in doubt, say N here. 725 726config PARAVIRT_CLOCK 727 bool 728 729endif #HYPERVISOR_GUEST 730 731config NO_BOOTMEM 732 def_bool y 733 734source "arch/x86/Kconfig.cpu" 735 736config HPET_TIMER 737 def_bool X86_64 738 prompt "HPET Timer Support" if X86_32 739 ---help--- 740 Use the IA-PC HPET (High Precision Event Timer) to manage 741 time in preference to the PIT and RTC, if a HPET is 742 present. 743 HPET is the next generation timer replacing legacy 8254s. 744 The HPET provides a stable time base on SMP 745 systems, unlike the TSC, but it is more expensive to access, 746 as it is off-chip. You can find the HPET spec at 747 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 748 749 You can safely choose Y here. However, HPET will only be 750 activated if the platform and the BIOS support this feature. 751 Otherwise the 8254 will be used for timing services. 752 753 Choose N to continue using the legacy 8254 timer. 754 755config HPET_EMULATE_RTC 756 def_bool y 757 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 758 759config APB_TIMER 760 def_bool y if X86_INTEL_MID 761 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 762 select DW_APB_TIMER 763 depends on X86_INTEL_MID && SFI 764 help 765 APB timer is the replacement for 8254, HPET on X86 MID platforms. 766 The APBT provides a stable time base on SMP 767 systems, unlike the TSC, but it is more expensive to access, 768 as it is off-chip. APB timers are always running regardless of CPU 769 C states, they are used as per CPU clockevent device when possible. 770 771# Mark as expert because too many people got it wrong. 772# The code disables itself when not needed. 773config DMI 774 default y 775 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 776 bool "Enable DMI scanning" if EXPERT 777 ---help--- 778 Enabled scanning of DMI to identify machine quirks. Say Y 779 here unless you have verified that your setup is not 780 affected by entries in the DMI blacklist. Required by PNP 781 BIOS code. 782 783config GART_IOMMU 784 bool "Old AMD GART IOMMU support" 785 select SWIOTLB 786 depends on X86_64 && PCI && AMD_NB 787 ---help--- 788 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 789 GART based hardware IOMMUs. 790 791 The GART supports full DMA access for devices with 32-bit access 792 limitations, on systems with more than 3 GB. This is usually needed 793 for USB, sound, many IDE/SATA chipsets and some other devices. 794 795 Newer systems typically have a modern AMD IOMMU, supported via 796 the CONFIG_AMD_IOMMU=y config option. 797 798 In normal configurations this driver is only active when needed: 799 there's more than 3 GB of memory and the system contains a 800 32-bit limited device. 801 802 If unsure, say Y. 803 804config CALGARY_IOMMU 805 bool "IBM Calgary IOMMU support" 806 select SWIOTLB 807 depends on X86_64 && PCI 808 ---help--- 809 Support for hardware IOMMUs in IBM's xSeries x366 and x460 810 systems. Needed to run systems with more than 3GB of memory 811 properly with 32-bit PCI devices that do not support DAC 812 (Double Address Cycle). Calgary also supports bus level 813 isolation, where all DMAs pass through the IOMMU. This 814 prevents them from going anywhere except their intended 815 destination. This catches hard-to-find kernel bugs and 816 mis-behaving drivers and devices that do not use the DMA-API 817 properly to set up their DMA buffers. The IOMMU can be 818 turned off at boot time with the iommu=off parameter. 819 Normally the kernel will make the right choice by itself. 820 If unsure, say Y. 821 822config CALGARY_IOMMU_ENABLED_BY_DEFAULT 823 def_bool y 824 prompt "Should Calgary be enabled by default?" 825 depends on CALGARY_IOMMU 826 ---help--- 827 Should Calgary be enabled by default? if you choose 'y', Calgary 828 will be used (if it exists). If you choose 'n', Calgary will not be 829 used even if it exists. If you choose 'n' and would like to use 830 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 831 If unsure, say Y. 832 833# need this always selected by IOMMU for the VIA workaround 834config SWIOTLB 835 def_bool y if X86_64 836 ---help--- 837 Support for software bounce buffers used on x86-64 systems 838 which don't have a hardware IOMMU. Using this PCI devices 839 which can only access 32-bits of memory can be used on systems 840 with more than 3 GB of memory. 841 If unsure, say Y. 842 843config IOMMU_HELPER 844 def_bool y 845 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 846 847config MAXSMP 848 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 849 depends on X86_64 && SMP && DEBUG_KERNEL 850 select CPUMASK_OFFSTACK 851 ---help--- 852 Enable maximum number of CPUS and NUMA Nodes for this architecture. 853 If unsure, say N. 854 855config NR_CPUS 856 int "Maximum number of CPUs" if SMP && !MAXSMP 857 range 2 8 if SMP && X86_32 && !X86_BIGSMP 858 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK 859 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 860 default "1" if !SMP 861 default "8192" if MAXSMP 862 default "32" if SMP && X86_BIGSMP 863 default "8" if SMP && X86_32 864 default "64" if SMP 865 ---help--- 866 This allows you to specify the maximum number of CPUs which this 867 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 868 supported value is 8192, otherwise the maximum value is 512. The 869 minimum value which makes sense is 2. 870 871 This is purely to save memory - each supported CPU adds 872 approximately eight kilobytes to the kernel image. 873 874config SCHED_SMT 875 bool "SMT (Hyperthreading) scheduler support" 876 depends on SMP 877 ---help--- 878 SMT scheduler support improves the CPU scheduler's decision making 879 when dealing with Intel Pentium 4 chips with HyperThreading at a 880 cost of slightly increased overhead in some places. If unsure say 881 N here. 882 883config SCHED_MC 884 def_bool y 885 prompt "Multi-core scheduler support" 886 depends on SMP 887 ---help--- 888 Multi-core scheduler support improves the CPU scheduler's decision 889 making when dealing with multi-core CPU chips at a cost of slightly 890 increased overhead in some places. If unsure say N here. 891 892source "kernel/Kconfig.preempt" 893 894config UP_LATE_INIT 895 def_bool y 896 depends on !SMP && X86_LOCAL_APIC 897 898config X86_UP_APIC 899 bool "Local APIC support on uniprocessors" if !PCI_MSI 900 default PCI_MSI 901 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 902 ---help--- 903 A local APIC (Advanced Programmable Interrupt Controller) is an 904 integrated interrupt controller in the CPU. If you have a single-CPU 905 system which has a processor with a local APIC, you can say Y here to 906 enable and use it. If you say Y here even though your machine doesn't 907 have a local APIC, then the kernel will still run with no slowdown at 908 all. The local APIC supports CPU-generated self-interrupts (timer, 909 performance counters), and the NMI watchdog which detects hard 910 lockups. 911 912config X86_UP_IOAPIC 913 bool "IO-APIC support on uniprocessors" 914 depends on X86_UP_APIC 915 ---help--- 916 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 917 SMP-capable replacement for PC-style interrupt controllers. Most 918 SMP systems and many recent uniprocessor systems have one. 919 920 If you have a single-CPU system with an IO-APIC, you can say Y here 921 to use it. If you say Y here even though your machine doesn't have 922 an IO-APIC, then the kernel will still run with no slowdown at all. 923 924config X86_LOCAL_APIC 925 def_bool y 926 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 927 select IRQ_DOMAIN_HIERARCHY 928 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 929 930config X86_IO_APIC 931 def_bool y 932 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 933 934config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 935 bool "Reroute for broken boot IRQs" 936 depends on X86_IO_APIC 937 ---help--- 938 This option enables a workaround that fixes a source of 939 spurious interrupts. This is recommended when threaded 940 interrupt handling is used on systems where the generation of 941 superfluous "boot interrupts" cannot be disabled. 942 943 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 944 entry in the chipset's IO-APIC is masked (as, e.g. the RT 945 kernel does during interrupt handling). On chipsets where this 946 boot IRQ generation cannot be disabled, this workaround keeps 947 the original IRQ line masked so that only the equivalent "boot 948 IRQ" is delivered to the CPUs. The workaround also tells the 949 kernel to set up the IRQ handler on the boot IRQ line. In this 950 way only one interrupt is delivered to the kernel. Otherwise 951 the spurious second interrupt may cause the kernel to bring 952 down (vital) interrupt lines. 953 954 Only affects "broken" chipsets. Interrupt sharing may be 955 increased on these systems. 956 957config X86_MCE 958 bool "Machine Check / overheating reporting" 959 select GENERIC_ALLOCATOR 960 default y 961 ---help--- 962 Machine Check support allows the processor to notify the 963 kernel if it detects a problem (e.g. overheating, data corruption). 964 The action the kernel takes depends on the severity of the problem, 965 ranging from warning messages to halting the machine. 966 967config X86_MCE_INTEL 968 def_bool y 969 prompt "Intel MCE features" 970 depends on X86_MCE && X86_LOCAL_APIC 971 ---help--- 972 Additional support for intel specific MCE features such as 973 the thermal monitor. 974 975config X86_MCE_AMD 976 def_bool y 977 prompt "AMD MCE features" 978 depends on X86_MCE && X86_LOCAL_APIC 979 ---help--- 980 Additional support for AMD specific MCE features such as 981 the DRAM Error Threshold. 982 983config X86_ANCIENT_MCE 984 bool "Support for old Pentium 5 / WinChip machine checks" 985 depends on X86_32 && X86_MCE 986 ---help--- 987 Include support for machine check handling on old Pentium 5 or WinChip 988 systems. These typically need to be enabled explicitly on the command 989 line. 990 991config X86_MCE_THRESHOLD 992 depends on X86_MCE_AMD || X86_MCE_INTEL 993 def_bool y 994 995config X86_MCE_INJECT 996 depends on X86_MCE 997 tristate "Machine check injector support" 998 ---help--- 999 Provide support for injecting machine checks for testing purposes. 1000 If you don't know what a machine check is and you don't do kernel 1001 QA it is safe to say n. 1002 1003config X86_THERMAL_VECTOR 1004 def_bool y 1005 depends on X86_MCE_INTEL 1006 1007config X86_LEGACY_VM86 1008 bool "Legacy VM86 support (obsolete)" 1009 default n 1010 depends on X86_32 1011 ---help--- 1012 This option allows user programs to put the CPU into V8086 1013 mode, which is an 80286-era approximation of 16-bit real mode. 1014 1015 Some very old versions of X and/or vbetool require this option 1016 for user mode setting. Similarly, DOSEMU will use it if 1017 available to accelerate real mode DOS programs. However, any 1018 recent version of DOSEMU, X, or vbetool should be fully 1019 functional even without kernel VM86 support, as they will all 1020 fall back to (pretty well performing) software emulation. 1021 1022 Anything that works on a 64-bit kernel is unlikely to need 1023 this option, as 64-bit kernels don't, and can't, support V8086 1024 mode. This option is also unrelated to 16-bit protected mode 1025 and is not needed to run most 16-bit programs under Wine. 1026 1027 Enabling this option adds considerable attack surface to the 1028 kernel and slows down system calls and exception handling. 1029 1030 Unless you use very old userspace or need the last drop of 1031 performance in your real mode DOS games and can't use KVM, 1032 say N here. 1033 1034config VM86 1035 bool 1036 default X86_LEGACY_VM86 1037 1038config X86_16BIT 1039 bool "Enable support for 16-bit segments" if EXPERT 1040 default y 1041 depends on MODIFY_LDT_SYSCALL 1042 ---help--- 1043 This option is required by programs like Wine to run 16-bit 1044 protected mode legacy code on x86 processors. Disabling 1045 this option saves about 300 bytes on i386, or around 6K text 1046 plus 16K runtime memory on x86-64, 1047 1048config X86_ESPFIX32 1049 def_bool y 1050 depends on X86_16BIT && X86_32 1051 1052config X86_ESPFIX64 1053 def_bool y 1054 depends on X86_16BIT && X86_64 1055 1056config X86_VSYSCALL_EMULATION 1057 bool "Enable vsyscall emulation" if EXPERT 1058 default y 1059 depends on X86_64 1060 ---help--- 1061 This enables emulation of the legacy vsyscall page. Disabling 1062 it is roughly equivalent to booting with vsyscall=none, except 1063 that it will also disable the helpful warning if a program 1064 tries to use a vsyscall. With this option set to N, offending 1065 programs will just segfault, citing addresses of the form 1066 0xffffffffff600?00. 1067 1068 This option is required by many programs built before 2013, and 1069 care should be used even with newer programs if set to N. 1070 1071 Disabling this option saves about 7K of kernel size and 1072 possibly 4K of additional runtime pagetable memory. 1073 1074config TOSHIBA 1075 tristate "Toshiba Laptop support" 1076 depends on X86_32 1077 ---help--- 1078 This adds a driver to safely access the System Management Mode of 1079 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1080 not work on models with a Phoenix BIOS. The System Management Mode 1081 is used to set the BIOS and power saving options on Toshiba portables. 1082 1083 For information on utilities to make use of this driver see the 1084 Toshiba Linux utilities web site at: 1085 <http://www.buzzard.org.uk/toshiba/>. 1086 1087 Say Y if you intend to run this kernel on a Toshiba portable. 1088 Say N otherwise. 1089 1090config I8K 1091 tristate "Dell i8k legacy laptop support" 1092 select HWMON 1093 select SENSORS_DELL_SMM 1094 ---help--- 1095 This option enables legacy /proc/i8k userspace interface in hwmon 1096 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1097 temperature and allows controlling fan speeds of Dell laptops via 1098 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1099 it reports also power and hotkey status. For fan speed control is 1100 needed userspace package i8kutils. 1101 1102 Say Y if you intend to run this kernel on old Dell laptops or want to 1103 use userspace package i8kutils. 1104 Say N otherwise. 1105 1106config X86_REBOOTFIXUPS 1107 bool "Enable X86 board specific fixups for reboot" 1108 depends on X86_32 1109 ---help--- 1110 This enables chipset and/or board specific fixups to be done 1111 in order to get reboot to work correctly. This is only needed on 1112 some combinations of hardware and BIOS. The symptom, for which 1113 this config is intended, is when reboot ends with a stalled/hung 1114 system. 1115 1116 Currently, the only fixup is for the Geode machines using 1117 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1118 1119 Say Y if you want to enable the fixup. Currently, it's safe to 1120 enable this option even if you don't need it. 1121 Say N otherwise. 1122 1123config MICROCODE 1124 tristate "CPU microcode loading support" 1125 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1126 select FW_LOADER 1127 ---help--- 1128 1129 If you say Y here, you will be able to update the microcode on 1130 certain Intel and AMD processors. The Intel support is for the 1131 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1132 Xeon etc. The AMD support is for families 0x10 and later. You will 1133 obviously need the actual microcode binary data itself which is not 1134 shipped with the Linux kernel. 1135 1136 This option selects the general module only, you need to select 1137 at least one vendor specific module as well. 1138 1139 To compile this driver as a module, choose M here: the module 1140 will be called microcode. 1141 1142config MICROCODE_INTEL 1143 bool "Intel microcode loading support" 1144 depends on MICROCODE 1145 default MICROCODE 1146 select FW_LOADER 1147 ---help--- 1148 This options enables microcode patch loading support for Intel 1149 processors. 1150 1151 For the current Intel microcode data package go to 1152 <https://downloadcenter.intel.com> and search for 1153 'Linux Processor Microcode Data File'. 1154 1155config MICROCODE_AMD 1156 bool "AMD microcode loading support" 1157 depends on MICROCODE 1158 select FW_LOADER 1159 ---help--- 1160 If you select this option, microcode patch loading support for AMD 1161 processors will be enabled. 1162 1163config MICROCODE_OLD_INTERFACE 1164 def_bool y 1165 depends on MICROCODE 1166 1167config MICROCODE_INTEL_EARLY 1168 bool 1169 1170config MICROCODE_AMD_EARLY 1171 bool 1172 1173config MICROCODE_EARLY 1174 bool "Early load microcode" 1175 depends on MICROCODE=y && BLK_DEV_INITRD 1176 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1177 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1178 default y 1179 help 1180 This option provides functionality to read additional microcode data 1181 at the beginning of initrd image. The data tells kernel to load 1182 microcode to CPU's as early as possible. No functional change if no 1183 microcode data is glued to the initrd, therefore it's safe to say Y. 1184 1185config X86_MSR 1186 tristate "/dev/cpu/*/msr - Model-specific register support" 1187 ---help--- 1188 This device gives privileged processes access to the x86 1189 Model-Specific Registers (MSRs). It is a character device with 1190 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1191 MSR accesses are directed to a specific CPU on multi-processor 1192 systems. 1193 1194config X86_CPUID 1195 tristate "/dev/cpu/*/cpuid - CPU information support" 1196 ---help--- 1197 This device gives processes access to the x86 CPUID instruction to 1198 be executed on a specific processor. It is a character device 1199 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1200 /dev/cpu/31/cpuid. 1201 1202choice 1203 prompt "High Memory Support" 1204 default HIGHMEM4G 1205 depends on X86_32 1206 1207config NOHIGHMEM 1208 bool "off" 1209 ---help--- 1210 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1211 However, the address space of 32-bit x86 processors is only 4 1212 Gigabytes large. That means that, if you have a large amount of 1213 physical memory, not all of it can be "permanently mapped" by the 1214 kernel. The physical memory that's not permanently mapped is called 1215 "high memory". 1216 1217 If you are compiling a kernel which will never run on a machine with 1218 more than 1 Gigabyte total physical RAM, answer "off" here (default 1219 choice and suitable for most users). This will result in a "3GB/1GB" 1220 split: 3GB are mapped so that each process sees a 3GB virtual memory 1221 space and the remaining part of the 4GB virtual memory space is used 1222 by the kernel to permanently map as much physical memory as 1223 possible. 1224 1225 If the machine has between 1 and 4 Gigabytes physical RAM, then 1226 answer "4GB" here. 1227 1228 If more than 4 Gigabytes is used then answer "64GB" here. This 1229 selection turns Intel PAE (Physical Address Extension) mode on. 1230 PAE implements 3-level paging on IA32 processors. PAE is fully 1231 supported by Linux, PAE mode is implemented on all recent Intel 1232 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1233 then the kernel will not boot on CPUs that don't support PAE! 1234 1235 The actual amount of total physical memory will either be 1236 auto detected or can be forced by using a kernel command line option 1237 such as "mem=256M". (Try "man bootparam" or see the documentation of 1238 your boot loader (lilo or loadlin) about how to pass options to the 1239 kernel at boot time.) 1240 1241 If unsure, say "off". 1242 1243config HIGHMEM4G 1244 bool "4GB" 1245 ---help--- 1246 Select this if you have a 32-bit processor and between 1 and 4 1247 gigabytes of physical RAM. 1248 1249config HIGHMEM64G 1250 bool "64GB" 1251 depends on !M486 1252 select X86_PAE 1253 ---help--- 1254 Select this if you have a 32-bit processor and more than 4 1255 gigabytes of physical RAM. 1256 1257endchoice 1258 1259choice 1260 prompt "Memory split" if EXPERT 1261 default VMSPLIT_3G 1262 depends on X86_32 1263 ---help--- 1264 Select the desired split between kernel and user memory. 1265 1266 If the address range available to the kernel is less than the 1267 physical memory installed, the remaining memory will be available 1268 as "high memory". Accessing high memory is a little more costly 1269 than low memory, as it needs to be mapped into the kernel first. 1270 Note that increasing the kernel address space limits the range 1271 available to user programs, making the address space there 1272 tighter. Selecting anything other than the default 3G/1G split 1273 will also likely make your kernel incompatible with binary-only 1274 kernel modules. 1275 1276 If you are not absolutely sure what you are doing, leave this 1277 option alone! 1278 1279 config VMSPLIT_3G 1280 bool "3G/1G user/kernel split" 1281 config VMSPLIT_3G_OPT 1282 depends on !X86_PAE 1283 bool "3G/1G user/kernel split (for full 1G low memory)" 1284 config VMSPLIT_2G 1285 bool "2G/2G user/kernel split" 1286 config VMSPLIT_2G_OPT 1287 depends on !X86_PAE 1288 bool "2G/2G user/kernel split (for full 2G low memory)" 1289 config VMSPLIT_1G 1290 bool "1G/3G user/kernel split" 1291endchoice 1292 1293config PAGE_OFFSET 1294 hex 1295 default 0xB0000000 if VMSPLIT_3G_OPT 1296 default 0x80000000 if VMSPLIT_2G 1297 default 0x78000000 if VMSPLIT_2G_OPT 1298 default 0x40000000 if VMSPLIT_1G 1299 default 0xC0000000 1300 depends on X86_32 1301 1302config HIGHMEM 1303 def_bool y 1304 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1305 1306config X86_PAE 1307 bool "PAE (Physical Address Extension) Support" 1308 depends on X86_32 && !HIGHMEM4G 1309 ---help--- 1310 PAE is required for NX support, and furthermore enables 1311 larger swapspace support for non-overcommit purposes. It 1312 has the cost of more pagetable lookup overhead, and also 1313 consumes more pagetable space per process. 1314 1315config ARCH_PHYS_ADDR_T_64BIT 1316 def_bool y 1317 depends on X86_64 || X86_PAE 1318 1319config ARCH_DMA_ADDR_T_64BIT 1320 def_bool y 1321 depends on X86_64 || HIGHMEM64G 1322 1323config X86_DIRECT_GBPAGES 1324 def_bool y 1325 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK 1326 ---help--- 1327 Certain kernel features effectively disable kernel 1328 linear 1 GB mappings (even if the CPU otherwise 1329 supports them), so don't confuse the user by printing 1330 that we have them enabled. 1331 1332# Common NUMA Features 1333config NUMA 1334 bool "Numa Memory Allocation and Scheduler Support" 1335 depends on SMP 1336 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1337 default y if X86_BIGSMP 1338 ---help--- 1339 Enable NUMA (Non Uniform Memory Access) support. 1340 1341 The kernel will try to allocate memory used by a CPU on the 1342 local memory controller of the CPU and add some more 1343 NUMA awareness to the kernel. 1344 1345 For 64-bit this is recommended if the system is Intel Core i7 1346 (or later), AMD Opteron, or EM64T NUMA. 1347 1348 For 32-bit this is only needed if you boot a 32-bit 1349 kernel on a 64-bit NUMA platform. 1350 1351 Otherwise, you should say N. 1352 1353config AMD_NUMA 1354 def_bool y 1355 prompt "Old style AMD Opteron NUMA detection" 1356 depends on X86_64 && NUMA && PCI 1357 ---help--- 1358 Enable AMD NUMA node topology detection. You should say Y here if 1359 you have a multi processor AMD system. This uses an old method to 1360 read the NUMA configuration directly from the builtin Northbridge 1361 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1362 which also takes priority if both are compiled in. 1363 1364config X86_64_ACPI_NUMA 1365 def_bool y 1366 prompt "ACPI NUMA detection" 1367 depends on X86_64 && NUMA && ACPI && PCI 1368 select ACPI_NUMA 1369 ---help--- 1370 Enable ACPI SRAT based node topology detection. 1371 1372# Some NUMA nodes have memory ranges that span 1373# other nodes. Even though a pfn is valid and 1374# between a node's start and end pfns, it may not 1375# reside on that node. See memmap_init_zone() 1376# for details. 1377config NODES_SPAN_OTHER_NODES 1378 def_bool y 1379 depends on X86_64_ACPI_NUMA 1380 1381config NUMA_EMU 1382 bool "NUMA emulation" 1383 depends on NUMA 1384 ---help--- 1385 Enable NUMA emulation. A flat machine will be split 1386 into virtual nodes when booted with "numa=fake=N", where N is the 1387 number of nodes. This is only useful for debugging. 1388 1389config NODES_SHIFT 1390 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1391 range 1 10 1392 default "10" if MAXSMP 1393 default "6" if X86_64 1394 default "3" 1395 depends on NEED_MULTIPLE_NODES 1396 ---help--- 1397 Specify the maximum number of NUMA Nodes available on the target 1398 system. Increases memory reserved to accommodate various tables. 1399 1400config ARCH_HAVE_MEMORY_PRESENT 1401 def_bool y 1402 depends on X86_32 && DISCONTIGMEM 1403 1404config NEED_NODE_MEMMAP_SIZE 1405 def_bool y 1406 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1407 1408config ARCH_FLATMEM_ENABLE 1409 def_bool y 1410 depends on X86_32 && !NUMA 1411 1412config ARCH_DISCONTIGMEM_ENABLE 1413 def_bool y 1414 depends on NUMA && X86_32 1415 1416config ARCH_DISCONTIGMEM_DEFAULT 1417 def_bool y 1418 depends on NUMA && X86_32 1419 1420config ARCH_SPARSEMEM_ENABLE 1421 def_bool y 1422 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1423 select SPARSEMEM_STATIC if X86_32 1424 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1425 1426config ARCH_SPARSEMEM_DEFAULT 1427 def_bool y 1428 depends on X86_64 1429 1430config ARCH_SELECT_MEMORY_MODEL 1431 def_bool y 1432 depends on ARCH_SPARSEMEM_ENABLE 1433 1434config ARCH_MEMORY_PROBE 1435 bool "Enable sysfs memory/probe interface" 1436 depends on X86_64 && MEMORY_HOTPLUG 1437 help 1438 This option enables a sysfs memory/probe interface for testing. 1439 See Documentation/memory-hotplug.txt for more information. 1440 If you are unsure how to answer this question, answer N. 1441 1442config ARCH_PROC_KCORE_TEXT 1443 def_bool y 1444 depends on X86_64 && PROC_KCORE 1445 1446config ILLEGAL_POINTER_VALUE 1447 hex 1448 default 0 if X86_32 1449 default 0xdead000000000000 if X86_64 1450 1451source "mm/Kconfig" 1452 1453config X86_PMEM_LEGACY 1454 bool "Support non-standard NVDIMMs and ADR protected memory" 1455 depends on PHYS_ADDR_T_64BIT 1456 depends on BLK_DEV 1457 select LIBNVDIMM 1458 help 1459 Treat memory marked using the non-standard e820 type of 12 as used 1460 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1461 The kernel will offer these regions to the 'pmem' driver so 1462 they can be used for persistent storage. 1463 1464 Say Y if unsure. 1465 1466config HIGHPTE 1467 bool "Allocate 3rd-level pagetables from highmem" 1468 depends on HIGHMEM 1469 ---help--- 1470 The VM uses one page table entry for each page of physical memory. 1471 For systems with a lot of RAM, this can be wasteful of precious 1472 low memory. Setting this option will put user-space page table 1473 entries in high memory. 1474 1475config X86_CHECK_BIOS_CORRUPTION 1476 bool "Check for low memory corruption" 1477 ---help--- 1478 Periodically check for memory corruption in low memory, which 1479 is suspected to be caused by BIOS. Even when enabled in the 1480 configuration, it is disabled at runtime. Enable it by 1481 setting "memory_corruption_check=1" on the kernel command 1482 line. By default it scans the low 64k of memory every 60 1483 seconds; see the memory_corruption_check_size and 1484 memory_corruption_check_period parameters in 1485 Documentation/kernel-parameters.txt to adjust this. 1486 1487 When enabled with the default parameters, this option has 1488 almost no overhead, as it reserves a relatively small amount 1489 of memory and scans it infrequently. It both detects corruption 1490 and prevents it from affecting the running system. 1491 1492 It is, however, intended as a diagnostic tool; if repeatable 1493 BIOS-originated corruption always affects the same memory, 1494 you can use memmap= to prevent the kernel from using that 1495 memory. 1496 1497config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1498 bool "Set the default setting of memory_corruption_check" 1499 depends on X86_CHECK_BIOS_CORRUPTION 1500 default y 1501 ---help--- 1502 Set whether the default state of memory_corruption_check is 1503 on or off. 1504 1505config X86_RESERVE_LOW 1506 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1507 default 64 1508 range 4 640 1509 ---help--- 1510 Specify the amount of low memory to reserve for the BIOS. 1511 1512 The first page contains BIOS data structures that the kernel 1513 must not use, so that page must always be reserved. 1514 1515 By default we reserve the first 64K of physical RAM, as a 1516 number of BIOSes are known to corrupt that memory range 1517 during events such as suspend/resume or monitor cable 1518 insertion, so it must not be used by the kernel. 1519 1520 You can set this to 4 if you are absolutely sure that you 1521 trust the BIOS to get all its memory reservations and usages 1522 right. If you know your BIOS have problems beyond the 1523 default 64K area, you can set this to 640 to avoid using the 1524 entire low memory range. 1525 1526 If you have doubts about the BIOS (e.g. suspend/resume does 1527 not work or there's kernel crashes after certain hardware 1528 hotplug events) then you might want to enable 1529 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1530 typical corruption patterns. 1531 1532 Leave this to the default value of 64 if you are unsure. 1533 1534config MATH_EMULATION 1535 bool 1536 depends on MODIFY_LDT_SYSCALL 1537 prompt "Math emulation" if X86_32 1538 ---help--- 1539 Linux can emulate a math coprocessor (used for floating point 1540 operations) if you don't have one. 486DX and Pentium processors have 1541 a math coprocessor built in, 486SX and 386 do not, unless you added 1542 a 487DX or 387, respectively. (The messages during boot time can 1543 give you some hints here ["man dmesg"].) Everyone needs either a 1544 coprocessor or this emulation. 1545 1546 If you don't have a math coprocessor, you need to say Y here; if you 1547 say Y here even though you have a coprocessor, the coprocessor will 1548 be used nevertheless. (This behavior can be changed with the kernel 1549 command line option "no387", which comes handy if your coprocessor 1550 is broken. Try "man bootparam" or see the documentation of your boot 1551 loader (lilo or loadlin) about how to pass options to the kernel at 1552 boot time.) This means that it is a good idea to say Y here if you 1553 intend to use this kernel on different machines. 1554 1555 More information about the internals of the Linux math coprocessor 1556 emulation can be found in <file:arch/x86/math-emu/README>. 1557 1558 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1559 kernel, it won't hurt. 1560 1561config MTRR 1562 def_bool y 1563 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1564 ---help--- 1565 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1566 the Memory Type Range Registers (MTRRs) may be used to control 1567 processor access to memory ranges. This is most useful if you have 1568 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1569 allows bus write transfers to be combined into a larger transfer 1570 before bursting over the PCI/AGP bus. This can increase performance 1571 of image write operations 2.5 times or more. Saying Y here creates a 1572 /proc/mtrr file which may be used to manipulate your processor's 1573 MTRRs. Typically the X server should use this. 1574 1575 This code has a reasonably generic interface so that similar 1576 control registers on other processors can be easily supported 1577 as well: 1578 1579 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1580 Registers (ARRs) which provide a similar functionality to MTRRs. For 1581 these, the ARRs are used to emulate the MTRRs. 1582 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1583 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1584 write-combining. All of these processors are supported by this code 1585 and it makes sense to say Y here if you have one of them. 1586 1587 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1588 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1589 can lead to all sorts of problems, so it's good to say Y here. 1590 1591 You can safely say Y even if your machine doesn't have MTRRs, you'll 1592 just add about 9 KB to your kernel. 1593 1594 See <file:Documentation/x86/mtrr.txt> for more information. 1595 1596config MTRR_SANITIZER 1597 def_bool y 1598 prompt "MTRR cleanup support" 1599 depends on MTRR 1600 ---help--- 1601 Convert MTRR layout from continuous to discrete, so X drivers can 1602 add writeback entries. 1603 1604 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1605 The largest mtrr entry size for a continuous block can be set with 1606 mtrr_chunk_size. 1607 1608 If unsure, say Y. 1609 1610config MTRR_SANITIZER_ENABLE_DEFAULT 1611 int "MTRR cleanup enable value (0-1)" 1612 range 0 1 1613 default "0" 1614 depends on MTRR_SANITIZER 1615 ---help--- 1616 Enable mtrr cleanup default value 1617 1618config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1619 int "MTRR cleanup spare reg num (0-7)" 1620 range 0 7 1621 default "1" 1622 depends on MTRR_SANITIZER 1623 ---help--- 1624 mtrr cleanup spare entries default, it can be changed via 1625 mtrr_spare_reg_nr=N on the kernel command line. 1626 1627config X86_PAT 1628 def_bool y 1629 prompt "x86 PAT support" if EXPERT 1630 depends on MTRR 1631 ---help--- 1632 Use PAT attributes to setup page level cache control. 1633 1634 PATs are the modern equivalents of MTRRs and are much more 1635 flexible than MTRRs. 1636 1637 Say N here if you see bootup problems (boot crash, boot hang, 1638 spontaneous reboots) or a non-working video driver. 1639 1640 If unsure, say Y. 1641 1642config ARCH_USES_PG_UNCACHED 1643 def_bool y 1644 depends on X86_PAT 1645 1646config ARCH_RANDOM 1647 def_bool y 1648 prompt "x86 architectural random number generator" if EXPERT 1649 ---help--- 1650 Enable the x86 architectural RDRAND instruction 1651 (Intel Bull Mountain technology) to generate random numbers. 1652 If supported, this is a high bandwidth, cryptographically 1653 secure hardware random number generator. 1654 1655config X86_SMAP 1656 def_bool y 1657 prompt "Supervisor Mode Access Prevention" if EXPERT 1658 ---help--- 1659 Supervisor Mode Access Prevention (SMAP) is a security 1660 feature in newer Intel processors. There is a small 1661 performance cost if this enabled and turned on; there is 1662 also a small increase in the kernel size if this is enabled. 1663 1664 If unsure, say Y. 1665 1666config X86_INTEL_MPX 1667 prompt "Intel MPX (Memory Protection Extensions)" 1668 def_bool n 1669 depends on CPU_SUP_INTEL 1670 ---help--- 1671 MPX provides hardware features that can be used in 1672 conjunction with compiler-instrumented code to check 1673 memory references. It is designed to detect buffer 1674 overflow or underflow bugs. 1675 1676 This option enables running applications which are 1677 instrumented or otherwise use MPX. It does not use MPX 1678 itself inside the kernel or to protect the kernel 1679 against bad memory references. 1680 1681 Enabling this option will make the kernel larger: 1682 ~8k of kernel text and 36 bytes of data on a 64-bit 1683 defconfig. It adds a long to the 'mm_struct' which 1684 will increase the kernel memory overhead of each 1685 process and adds some branches to paths used during 1686 exec() and munmap(). 1687 1688 For details, see Documentation/x86/intel_mpx.txt 1689 1690 If unsure, say N. 1691 1692config EFI 1693 bool "EFI runtime service support" 1694 depends on ACPI 1695 select UCS2_STRING 1696 select EFI_RUNTIME_WRAPPERS 1697 ---help--- 1698 This enables the kernel to use EFI runtime services that are 1699 available (such as the EFI variable services). 1700 1701 This option is only useful on systems that have EFI firmware. 1702 In addition, you should use the latest ELILO loader available 1703 at <http://elilo.sourceforge.net> in order to take advantage 1704 of EFI runtime services. However, even with this option, the 1705 resultant kernel should continue to boot on existing non-EFI 1706 platforms. 1707 1708config EFI_STUB 1709 bool "EFI stub support" 1710 depends on EFI && !X86_USE_3DNOW 1711 select RELOCATABLE 1712 ---help--- 1713 This kernel feature allows a bzImage to be loaded directly 1714 by EFI firmware without the use of a bootloader. 1715 1716 See Documentation/efi-stub.txt for more information. 1717 1718config EFI_MIXED 1719 bool "EFI mixed-mode support" 1720 depends on EFI_STUB && X86_64 1721 ---help--- 1722 Enabling this feature allows a 64-bit kernel to be booted 1723 on a 32-bit firmware, provided that your CPU supports 64-bit 1724 mode. 1725 1726 Note that it is not possible to boot a mixed-mode enabled 1727 kernel via the EFI boot stub - a bootloader that supports 1728 the EFI handover protocol must be used. 1729 1730 If unsure, say N. 1731 1732config SECCOMP 1733 def_bool y 1734 prompt "Enable seccomp to safely compute untrusted bytecode" 1735 ---help--- 1736 This kernel feature is useful for number crunching applications 1737 that may need to compute untrusted bytecode during their 1738 execution. By using pipes or other transports made available to 1739 the process as file descriptors supporting the read/write 1740 syscalls, it's possible to isolate those applications in 1741 their own address space using seccomp. Once seccomp is 1742 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1743 and the task is only allowed to execute a few safe syscalls 1744 defined by each seccomp mode. 1745 1746 If unsure, say Y. Only embedded should say N here. 1747 1748source kernel/Kconfig.hz 1749 1750config KEXEC 1751 bool "kexec system call" 1752 ---help--- 1753 kexec is a system call that implements the ability to shutdown your 1754 current kernel, and to start another kernel. It is like a reboot 1755 but it is independent of the system firmware. And like a reboot 1756 you can start any kernel with it, not just Linux. 1757 1758 The name comes from the similarity to the exec system call. 1759 1760 It is an ongoing process to be certain the hardware in a machine 1761 is properly shutdown, so do not be surprised if this code does not 1762 initially work for you. As of this writing the exact hardware 1763 interface is strongly in flux, so no good recommendation can be 1764 made. 1765 1766config KEXEC_FILE 1767 bool "kexec file based system call" 1768 select BUILD_BIN2C 1769 depends on KEXEC 1770 depends on X86_64 1771 depends on CRYPTO=y 1772 depends on CRYPTO_SHA256=y 1773 ---help--- 1774 This is new version of kexec system call. This system call is 1775 file based and takes file descriptors as system call argument 1776 for kernel and initramfs as opposed to list of segments as 1777 accepted by previous system call. 1778 1779config KEXEC_VERIFY_SIG 1780 bool "Verify kernel signature during kexec_file_load() syscall" 1781 depends on KEXEC_FILE 1782 ---help--- 1783 This option makes kernel signature verification mandatory for 1784 the kexec_file_load() syscall. 1785 1786 In addition to that option, you need to enable signature 1787 verification for the corresponding kernel image type being 1788 loaded in order for this to work. 1789 1790config KEXEC_BZIMAGE_VERIFY_SIG 1791 bool "Enable bzImage signature verification support" 1792 depends on KEXEC_VERIFY_SIG 1793 depends on SIGNED_PE_FILE_VERIFICATION 1794 select SYSTEM_TRUSTED_KEYRING 1795 ---help--- 1796 Enable bzImage signature verification support. 1797 1798config CRASH_DUMP 1799 bool "kernel crash dumps" 1800 depends on X86_64 || (X86_32 && HIGHMEM) 1801 ---help--- 1802 Generate crash dump after being started by kexec. 1803 This should be normally only set in special crash dump kernels 1804 which are loaded in the main kernel with kexec-tools into 1805 a specially reserved region and then later executed after 1806 a crash by kdump/kexec. The crash dump kernel must be compiled 1807 to a memory address not used by the main kernel or BIOS using 1808 PHYSICAL_START, or it must be built as a relocatable image 1809 (CONFIG_RELOCATABLE=y). 1810 For more details see Documentation/kdump/kdump.txt 1811 1812config KEXEC_JUMP 1813 bool "kexec jump" 1814 depends on KEXEC && HIBERNATION 1815 ---help--- 1816 Jump between original kernel and kexeced kernel and invoke 1817 code in physical address mode via KEXEC 1818 1819config PHYSICAL_START 1820 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1821 default "0x1000000" 1822 ---help--- 1823 This gives the physical address where the kernel is loaded. 1824 1825 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1826 bzImage will decompress itself to above physical address and 1827 run from there. Otherwise, bzImage will run from the address where 1828 it has been loaded by the boot loader and will ignore above physical 1829 address. 1830 1831 In normal kdump cases one does not have to set/change this option 1832 as now bzImage can be compiled as a completely relocatable image 1833 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1834 address. This option is mainly useful for the folks who don't want 1835 to use a bzImage for capturing the crash dump and want to use a 1836 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1837 to be specifically compiled to run from a specific memory area 1838 (normally a reserved region) and this option comes handy. 1839 1840 So if you are using bzImage for capturing the crash dump, 1841 leave the value here unchanged to 0x1000000 and set 1842 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1843 for capturing the crash dump change this value to start of 1844 the reserved region. In other words, it can be set based on 1845 the "X" value as specified in the "crashkernel=YM@XM" 1846 command line boot parameter passed to the panic-ed 1847 kernel. Please take a look at Documentation/kdump/kdump.txt 1848 for more details about crash dumps. 1849 1850 Usage of bzImage for capturing the crash dump is recommended as 1851 one does not have to build two kernels. Same kernel can be used 1852 as production kernel and capture kernel. Above option should have 1853 gone away after relocatable bzImage support is introduced. But it 1854 is present because there are users out there who continue to use 1855 vmlinux for dump capture. This option should go away down the 1856 line. 1857 1858 Don't change this unless you know what you are doing. 1859 1860config RELOCATABLE 1861 bool "Build a relocatable kernel" 1862 default y 1863 ---help--- 1864 This builds a kernel image that retains relocation information 1865 so it can be loaded someplace besides the default 1MB. 1866 The relocations tend to make the kernel binary about 10% larger, 1867 but are discarded at runtime. 1868 1869 One use is for the kexec on panic case where the recovery kernel 1870 must live at a different physical address than the primary 1871 kernel. 1872 1873 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1874 it has been loaded at and the compile time physical address 1875 (CONFIG_PHYSICAL_START) is used as the minimum location. 1876 1877config RANDOMIZE_BASE 1878 bool "Randomize the address of the kernel image" 1879 depends on RELOCATABLE 1880 default n 1881 ---help--- 1882 Randomizes the physical and virtual address at which the 1883 kernel image is decompressed, as a security feature that 1884 deters exploit attempts relying on knowledge of the location 1885 of kernel internals. 1886 1887 Entropy is generated using the RDRAND instruction if it is 1888 supported. If RDTSC is supported, it is used as well. If 1889 neither RDRAND nor RDTSC are supported, then randomness is 1890 read from the i8254 timer. 1891 1892 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET, 1893 and aligned according to PHYSICAL_ALIGN. Since the kernel is 1894 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a 1895 minimum of 2MiB, only 10 bits of entropy is theoretically 1896 possible. At best, due to page table layouts, 64-bit can use 1897 9 bits of entropy and 32-bit uses 8 bits. 1898 1899 If unsure, say N. 1900 1901config RANDOMIZE_BASE_MAX_OFFSET 1902 hex "Maximum kASLR offset allowed" if EXPERT 1903 depends on RANDOMIZE_BASE 1904 range 0x0 0x20000000 if X86_32 1905 default "0x20000000" if X86_32 1906 range 0x0 0x40000000 if X86_64 1907 default "0x40000000" if X86_64 1908 ---help--- 1909 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical 1910 memory is used to determine the maximal offset in bytes that will 1911 be applied to the kernel when kernel Address Space Layout 1912 Randomization (kASLR) is active. This must be a multiple of 1913 PHYSICAL_ALIGN. 1914 1915 On 32-bit this is limited to 512MiB by page table layouts. The 1916 default is 512MiB. 1917 1918 On 64-bit this is limited by how the kernel fixmap page table is 1919 positioned, so this cannot be larger than 1GiB currently. Without 1920 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel 1921 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the 1922 modules area will shrink to compensate, up to the current maximum 1923 1GiB to 1GiB split. The default is 1GiB. 1924 1925 If unsure, leave at the default value. 1926 1927# Relocation on x86 needs some additional build support 1928config X86_NEED_RELOCS 1929 def_bool y 1930 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 1931 1932config PHYSICAL_ALIGN 1933 hex "Alignment value to which kernel should be aligned" 1934 default "0x200000" 1935 range 0x2000 0x1000000 if X86_32 1936 range 0x200000 0x1000000 if X86_64 1937 ---help--- 1938 This value puts the alignment restrictions on physical address 1939 where kernel is loaded and run from. Kernel is compiled for an 1940 address which meets above alignment restriction. 1941 1942 If bootloader loads the kernel at a non-aligned address and 1943 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1944 address aligned to above value and run from there. 1945 1946 If bootloader loads the kernel at a non-aligned address and 1947 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1948 load address and decompress itself to the address it has been 1949 compiled for and run from there. The address for which kernel is 1950 compiled already meets above alignment restrictions. Hence the 1951 end result is that kernel runs from a physical address meeting 1952 above alignment restrictions. 1953 1954 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1955 this value must be a multiple of 0x200000. 1956 1957 Don't change this unless you know what you are doing. 1958 1959config HOTPLUG_CPU 1960 bool "Support for hot-pluggable CPUs" 1961 depends on SMP 1962 ---help--- 1963 Say Y here to allow turning CPUs off and on. CPUs can be 1964 controlled through /sys/devices/system/cpu. 1965 ( Note: power management support will enable this option 1966 automatically on SMP systems. ) 1967 Say N if you want to disable CPU hotplug. 1968 1969config BOOTPARAM_HOTPLUG_CPU0 1970 bool "Set default setting of cpu0_hotpluggable" 1971 default n 1972 depends on HOTPLUG_CPU 1973 ---help--- 1974 Set whether default state of cpu0_hotpluggable is on or off. 1975 1976 Say Y here to enable CPU0 hotplug by default. If this switch 1977 is turned on, there is no need to give cpu0_hotplug kernel 1978 parameter and the CPU0 hotplug feature is enabled by default. 1979 1980 Please note: there are two known CPU0 dependencies if you want 1981 to enable the CPU0 hotplug feature either by this switch or by 1982 cpu0_hotplug kernel parameter. 1983 1984 First, resume from hibernate or suspend always starts from CPU0. 1985 So hibernate and suspend are prevented if CPU0 is offline. 1986 1987 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1988 offline if any interrupt can not migrate out of CPU0. There may 1989 be other CPU0 dependencies. 1990 1991 Please make sure the dependencies are under your control before 1992 you enable this feature. 1993 1994 Say N if you don't want to enable CPU0 hotplug feature by default. 1995 You still can enable the CPU0 hotplug feature at boot by kernel 1996 parameter cpu0_hotplug. 1997 1998config DEBUG_HOTPLUG_CPU0 1999 def_bool n 2000 prompt "Debug CPU0 hotplug" 2001 depends on HOTPLUG_CPU 2002 ---help--- 2003 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2004 soon as possible and boots up userspace with CPU0 offlined. User 2005 can online CPU0 back after boot time. 2006 2007 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2008 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2009 compilation or giving cpu0_hotplug kernel parameter at boot. 2010 2011 If unsure, say N. 2012 2013config COMPAT_VDSO 2014 def_bool n 2015 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2016 depends on X86_32 || IA32_EMULATION 2017 ---help--- 2018 Certain buggy versions of glibc will crash if they are 2019 presented with a 32-bit vDSO that is not mapped at the address 2020 indicated in its segment table. 2021 2022 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2023 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2024 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2025 the only released version with the bug, but OpenSUSE 9 2026 contains a buggy "glibc 2.3.2". 2027 2028 The symptom of the bug is that everything crashes on startup, saying: 2029 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2030 2031 Saying Y here changes the default value of the vdso32 boot 2032 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2033 This works around the glibc bug but hurts performance. 2034 2035 If unsure, say N: if you are compiling your own kernel, you 2036 are unlikely to be using a buggy version of glibc. 2037 2038config CMDLINE_BOOL 2039 bool "Built-in kernel command line" 2040 ---help--- 2041 Allow for specifying boot arguments to the kernel at 2042 build time. On some systems (e.g. embedded ones), it is 2043 necessary or convenient to provide some or all of the 2044 kernel boot arguments with the kernel itself (that is, 2045 to not rely on the boot loader to provide them.) 2046 2047 To compile command line arguments into the kernel, 2048 set this option to 'Y', then fill in the 2049 boot arguments in CONFIG_CMDLINE. 2050 2051 Systems with fully functional boot loaders (i.e. non-embedded) 2052 should leave this option set to 'N'. 2053 2054config CMDLINE 2055 string "Built-in kernel command string" 2056 depends on CMDLINE_BOOL 2057 default "" 2058 ---help--- 2059 Enter arguments here that should be compiled into the kernel 2060 image and used at boot time. If the boot loader provides a 2061 command line at boot time, it is appended to this string to 2062 form the full kernel command line, when the system boots. 2063 2064 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2065 change this behavior. 2066 2067 In most cases, the command line (whether built-in or provided 2068 by the boot loader) should specify the device for the root 2069 file system. 2070 2071config CMDLINE_OVERRIDE 2072 bool "Built-in command line overrides boot loader arguments" 2073 depends on CMDLINE_BOOL 2074 ---help--- 2075 Set this option to 'Y' to have the kernel ignore the boot loader 2076 command line, and use ONLY the built-in command line. 2077 2078 This is used to work around broken boot loaders. This should 2079 be set to 'N' under normal conditions. 2080 2081config MODIFY_LDT_SYSCALL 2082 bool "Enable the LDT (local descriptor table)" if EXPERT 2083 default y 2084 ---help--- 2085 Linux can allow user programs to install a per-process x86 2086 Local Descriptor Table (LDT) using the modify_ldt(2) system 2087 call. This is required to run 16-bit or segmented code such as 2088 DOSEMU or some Wine programs. It is also used by some very old 2089 threading libraries. 2090 2091 Enabling this feature adds a small amount of overhead to 2092 context switches and increases the low-level kernel attack 2093 surface. Disabling it removes the modify_ldt(2) system call. 2094 2095 Saying 'N' here may make sense for embedded or server kernels. 2096 2097source "kernel/livepatch/Kconfig" 2098 2099endmenu 2100 2101config ARCH_ENABLE_MEMORY_HOTPLUG 2102 def_bool y 2103 depends on X86_64 || (X86_32 && HIGHMEM) 2104 2105config ARCH_ENABLE_MEMORY_HOTREMOVE 2106 def_bool y 2107 depends on MEMORY_HOTPLUG 2108 2109config USE_PERCPU_NUMA_NODE_ID 2110 def_bool y 2111 depends on NUMA 2112 2113config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2114 def_bool y 2115 depends on X86_64 || X86_PAE 2116 2117config ARCH_ENABLE_HUGEPAGE_MIGRATION 2118 def_bool y 2119 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2120 2121menu "Power management and ACPI options" 2122 2123config ARCH_HIBERNATION_HEADER 2124 def_bool y 2125 depends on X86_64 && HIBERNATION 2126 2127source "kernel/power/Kconfig" 2128 2129source "drivers/acpi/Kconfig" 2130 2131source "drivers/sfi/Kconfig" 2132 2133config X86_APM_BOOT 2134 def_bool y 2135 depends on APM 2136 2137menuconfig APM 2138 tristate "APM (Advanced Power Management) BIOS support" 2139 depends on X86_32 && PM_SLEEP 2140 ---help--- 2141 APM is a BIOS specification for saving power using several different 2142 techniques. This is mostly useful for battery powered laptops with 2143 APM compliant BIOSes. If you say Y here, the system time will be 2144 reset after a RESUME operation, the /proc/apm device will provide 2145 battery status information, and user-space programs will receive 2146 notification of APM "events" (e.g. battery status change). 2147 2148 If you select "Y" here, you can disable actual use of the APM 2149 BIOS by passing the "apm=off" option to the kernel at boot time. 2150 2151 Note that the APM support is almost completely disabled for 2152 machines with more than one CPU. 2153 2154 In order to use APM, you will need supporting software. For location 2155 and more information, read <file:Documentation/power/apm-acpi.txt> 2156 and the Battery Powered Linux mini-HOWTO, available from 2157 <http://www.tldp.org/docs.html#howto>. 2158 2159 This driver does not spin down disk drives (see the hdparm(8) 2160 manpage ("man 8 hdparm") for that), and it doesn't turn off 2161 VESA-compliant "green" monitors. 2162 2163 This driver does not support the TI 4000M TravelMate and the ACER 2164 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2165 desktop machines also don't have compliant BIOSes, and this driver 2166 may cause those machines to panic during the boot phase. 2167 2168 Generally, if you don't have a battery in your machine, there isn't 2169 much point in using this driver and you should say N. If you get 2170 random kernel OOPSes or reboots that don't seem to be related to 2171 anything, try disabling/enabling this option (or disabling/enabling 2172 APM in your BIOS). 2173 2174 Some other things you should try when experiencing seemingly random, 2175 "weird" problems: 2176 2177 1) make sure that you have enough swap space and that it is 2178 enabled. 2179 2) pass the "no-hlt" option to the kernel 2180 3) switch on floating point emulation in the kernel and pass 2181 the "no387" option to the kernel 2182 4) pass the "floppy=nodma" option to the kernel 2183 5) pass the "mem=4M" option to the kernel (thereby disabling 2184 all but the first 4 MB of RAM) 2185 6) make sure that the CPU is not over clocked. 2186 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2187 8) disable the cache from your BIOS settings 2188 9) install a fan for the video card or exchange video RAM 2189 10) install a better fan for the CPU 2190 11) exchange RAM chips 2191 12) exchange the motherboard. 2192 2193 To compile this driver as a module, choose M here: the 2194 module will be called apm. 2195 2196if APM 2197 2198config APM_IGNORE_USER_SUSPEND 2199 bool "Ignore USER SUSPEND" 2200 ---help--- 2201 This option will ignore USER SUSPEND requests. On machines with a 2202 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2203 series notebooks, it is necessary to say Y because of a BIOS bug. 2204 2205config APM_DO_ENABLE 2206 bool "Enable PM at boot time" 2207 ---help--- 2208 Enable APM features at boot time. From page 36 of the APM BIOS 2209 specification: "When disabled, the APM BIOS does not automatically 2210 power manage devices, enter the Standby State, enter the Suspend 2211 State, or take power saving steps in response to CPU Idle calls." 2212 This driver will make CPU Idle calls when Linux is idle (unless this 2213 feature is turned off -- see "Do CPU IDLE calls", below). This 2214 should always save battery power, but more complicated APM features 2215 will be dependent on your BIOS implementation. You may need to turn 2216 this option off if your computer hangs at boot time when using APM 2217 support, or if it beeps continuously instead of suspending. Turn 2218 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2219 T400CDT. This is off by default since most machines do fine without 2220 this feature. 2221 2222config APM_CPU_IDLE 2223 depends on CPU_IDLE 2224 bool "Make CPU Idle calls when idle" 2225 ---help--- 2226 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2227 On some machines, this can activate improved power savings, such as 2228 a slowed CPU clock rate, when the machine is idle. These idle calls 2229 are made after the idle loop has run for some length of time (e.g., 2230 333 mS). On some machines, this will cause a hang at boot time or 2231 whenever the CPU becomes idle. (On machines with more than one CPU, 2232 this option does nothing.) 2233 2234config APM_DISPLAY_BLANK 2235 bool "Enable console blanking using APM" 2236 ---help--- 2237 Enable console blanking using the APM. Some laptops can use this to 2238 turn off the LCD backlight when the screen blanker of the Linux 2239 virtual console blanks the screen. Note that this is only used by 2240 the virtual console screen blanker, and won't turn off the backlight 2241 when using the X Window system. This also doesn't have anything to 2242 do with your VESA-compliant power-saving monitor. Further, this 2243 option doesn't work for all laptops -- it might not turn off your 2244 backlight at all, or it might print a lot of errors to the console, 2245 especially if you are using gpm. 2246 2247config APM_ALLOW_INTS 2248 bool "Allow interrupts during APM BIOS calls" 2249 ---help--- 2250 Normally we disable external interrupts while we are making calls to 2251 the APM BIOS as a measure to lessen the effects of a badly behaving 2252 BIOS implementation. The BIOS should reenable interrupts if it 2253 needs to. Unfortunately, some BIOSes do not -- especially those in 2254 many of the newer IBM Thinkpads. If you experience hangs when you 2255 suspend, try setting this to Y. Otherwise, say N. 2256 2257endif # APM 2258 2259source "drivers/cpufreq/Kconfig" 2260 2261source "drivers/cpuidle/Kconfig" 2262 2263source "drivers/idle/Kconfig" 2264 2265endmenu 2266 2267 2268menu "Bus options (PCI etc.)" 2269 2270config PCI 2271 bool "PCI support" 2272 default y 2273 ---help--- 2274 Find out whether you have a PCI motherboard. PCI is the name of a 2275 bus system, i.e. the way the CPU talks to the other stuff inside 2276 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2277 VESA. If you have PCI, say Y, otherwise N. 2278 2279choice 2280 prompt "PCI access mode" 2281 depends on X86_32 && PCI 2282 default PCI_GOANY 2283 ---help--- 2284 On PCI systems, the BIOS can be used to detect the PCI devices and 2285 determine their configuration. However, some old PCI motherboards 2286 have BIOS bugs and may crash if this is done. Also, some embedded 2287 PCI-based systems don't have any BIOS at all. Linux can also try to 2288 detect the PCI hardware directly without using the BIOS. 2289 2290 With this option, you can specify how Linux should detect the 2291 PCI devices. If you choose "BIOS", the BIOS will be used, 2292 if you choose "Direct", the BIOS won't be used, and if you 2293 choose "MMConfig", then PCI Express MMCONFIG will be used. 2294 If you choose "Any", the kernel will try MMCONFIG, then the 2295 direct access method and falls back to the BIOS if that doesn't 2296 work. If unsure, go with the default, which is "Any". 2297 2298config PCI_GOBIOS 2299 bool "BIOS" 2300 2301config PCI_GOMMCONFIG 2302 bool "MMConfig" 2303 2304config PCI_GODIRECT 2305 bool "Direct" 2306 2307config PCI_GOOLPC 2308 bool "OLPC XO-1" 2309 depends on OLPC 2310 2311config PCI_GOANY 2312 bool "Any" 2313 2314endchoice 2315 2316config PCI_BIOS 2317 def_bool y 2318 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2319 2320# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2321config PCI_DIRECT 2322 def_bool y 2323 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2324 2325config PCI_MMCONFIG 2326 def_bool y 2327 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2328 2329config PCI_OLPC 2330 def_bool y 2331 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2332 2333config PCI_XEN 2334 def_bool y 2335 depends on PCI && XEN 2336 select SWIOTLB_XEN 2337 2338config PCI_DOMAINS 2339 def_bool y 2340 depends on PCI 2341 2342config PCI_MMCONFIG 2343 bool "Support mmconfig PCI config space access" 2344 depends on X86_64 && PCI && ACPI 2345 2346config PCI_CNB20LE_QUIRK 2347 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2348 depends on PCI 2349 help 2350 Read the PCI windows out of the CNB20LE host bridge. This allows 2351 PCI hotplug to work on systems with the CNB20LE chipset which do 2352 not have ACPI. 2353 2354 There's no public spec for this chipset, and this functionality 2355 is known to be incomplete. 2356 2357 You should say N unless you know you need this. 2358 2359source "drivers/pci/pcie/Kconfig" 2360 2361source "drivers/pci/Kconfig" 2362 2363# x86_64 have no ISA slots, but can have ISA-style DMA. 2364config ISA_DMA_API 2365 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2366 default y 2367 help 2368 Enables ISA-style DMA support for devices requiring such controllers. 2369 If unsure, say Y. 2370 2371if X86_32 2372 2373config ISA 2374 bool "ISA support" 2375 ---help--- 2376 Find out whether you have ISA slots on your motherboard. ISA is the 2377 name of a bus system, i.e. the way the CPU talks to the other stuff 2378 inside your box. Other bus systems are PCI, EISA, MicroChannel 2379 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2380 newer boards don't support it. If you have ISA, say Y, otherwise N. 2381 2382config EISA 2383 bool "EISA support" 2384 depends on ISA 2385 ---help--- 2386 The Extended Industry Standard Architecture (EISA) bus was 2387 developed as an open alternative to the IBM MicroChannel bus. 2388 2389 The EISA bus provided some of the features of the IBM MicroChannel 2390 bus while maintaining backward compatibility with cards made for 2391 the older ISA bus. The EISA bus saw limited use between 1988 and 2392 1995 when it was made obsolete by the PCI bus. 2393 2394 Say Y here if you are building a kernel for an EISA-based machine. 2395 2396 Otherwise, say N. 2397 2398source "drivers/eisa/Kconfig" 2399 2400config SCx200 2401 tristate "NatSemi SCx200 support" 2402 ---help--- 2403 This provides basic support for National Semiconductor's 2404 (now AMD's) Geode processors. The driver probes for the 2405 PCI-IDs of several on-chip devices, so its a good dependency 2406 for other scx200_* drivers. 2407 2408 If compiled as a module, the driver is named scx200. 2409 2410config SCx200HR_TIMER 2411 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2412 depends on SCx200 2413 default y 2414 ---help--- 2415 This driver provides a clocksource built upon the on-chip 2416 27MHz high-resolution timer. Its also a workaround for 2417 NSC Geode SC-1100's buggy TSC, which loses time when the 2418 processor goes idle (as is done by the scheduler). The 2419 other workaround is idle=poll boot option. 2420 2421config OLPC 2422 bool "One Laptop Per Child support" 2423 depends on !X86_PAE 2424 select GPIOLIB 2425 select OF 2426 select OF_PROMTREE 2427 select IRQ_DOMAIN 2428 ---help--- 2429 Add support for detecting the unique features of the OLPC 2430 XO hardware. 2431 2432config OLPC_XO1_PM 2433 bool "OLPC XO-1 Power Management" 2434 depends on OLPC && MFD_CS5535 && PM_SLEEP 2435 select MFD_CORE 2436 ---help--- 2437 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2438 2439config OLPC_XO1_RTC 2440 bool "OLPC XO-1 Real Time Clock" 2441 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2442 ---help--- 2443 Add support for the XO-1 real time clock, which can be used as a 2444 programmable wakeup source. 2445 2446config OLPC_XO1_SCI 2447 bool "OLPC XO-1 SCI extras" 2448 depends on OLPC && OLPC_XO1_PM 2449 depends on INPUT=y 2450 select POWER_SUPPLY 2451 select GPIO_CS5535 2452 select MFD_CORE 2453 ---help--- 2454 Add support for SCI-based features of the OLPC XO-1 laptop: 2455 - EC-driven system wakeups 2456 - Power button 2457 - Ebook switch 2458 - Lid switch 2459 - AC adapter status updates 2460 - Battery status updates 2461 2462config OLPC_XO15_SCI 2463 bool "OLPC XO-1.5 SCI extras" 2464 depends on OLPC && ACPI 2465 select POWER_SUPPLY 2466 ---help--- 2467 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2468 - EC-driven system wakeups 2469 - AC adapter status updates 2470 - Battery status updates 2471 2472config ALIX 2473 bool "PCEngines ALIX System Support (LED setup)" 2474 select GPIOLIB 2475 ---help--- 2476 This option enables system support for the PCEngines ALIX. 2477 At present this just sets up LEDs for GPIO control on 2478 ALIX2/3/6 boards. However, other system specific setup should 2479 get added here. 2480 2481 Note: You must still enable the drivers for GPIO and LED support 2482 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2483 2484 Note: You have to set alix.force=1 for boards with Award BIOS. 2485 2486config NET5501 2487 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2488 select GPIOLIB 2489 ---help--- 2490 This option enables system support for the Soekris Engineering net5501. 2491 2492config GEOS 2493 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2494 select GPIOLIB 2495 depends on DMI 2496 ---help--- 2497 This option enables system support for the Traverse Technologies GEOS. 2498 2499config TS5500 2500 bool "Technologic Systems TS-5500 platform support" 2501 depends on MELAN 2502 select CHECK_SIGNATURE 2503 select NEW_LEDS 2504 select LEDS_CLASS 2505 ---help--- 2506 This option enables system support for the Technologic Systems TS-5500. 2507 2508endif # X86_32 2509 2510config AMD_NB 2511 def_bool y 2512 depends on CPU_SUP_AMD && PCI 2513 2514source "drivers/pcmcia/Kconfig" 2515 2516source "drivers/pci/hotplug/Kconfig" 2517 2518config RAPIDIO 2519 tristate "RapidIO support" 2520 depends on PCI 2521 default n 2522 help 2523 If enabled this option will include drivers and the core 2524 infrastructure code to support RapidIO interconnect devices. 2525 2526source "drivers/rapidio/Kconfig" 2527 2528config X86_SYSFB 2529 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2530 help 2531 Firmwares often provide initial graphics framebuffers so the BIOS, 2532 bootloader or kernel can show basic video-output during boot for 2533 user-guidance and debugging. Historically, x86 used the VESA BIOS 2534 Extensions and EFI-framebuffers for this, which are mostly limited 2535 to x86. 2536 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2537 framebuffers so the new generic system-framebuffer drivers can be 2538 used on x86. If the framebuffer is not compatible with the generic 2539 modes, it is adverticed as fallback platform framebuffer so legacy 2540 drivers like efifb, vesafb and uvesafb can pick it up. 2541 If this option is not selected, all system framebuffers are always 2542 marked as fallback platform framebuffers as usual. 2543 2544 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2545 not be able to pick up generic system framebuffers if this option 2546 is selected. You are highly encouraged to enable simplefb as 2547 replacement if you select this option. simplefb can correctly deal 2548 with generic system framebuffers. But you should still keep vesafb 2549 and others enabled as fallback if a system framebuffer is 2550 incompatible with simplefb. 2551 2552 If unsure, say Y. 2553 2554endmenu 2555 2556 2557menu "Executable file formats / Emulations" 2558 2559source "fs/Kconfig.binfmt" 2560 2561config IA32_EMULATION 2562 bool "IA32 Emulation" 2563 depends on X86_64 2564 select BINFMT_ELF 2565 select COMPAT_BINFMT_ELF 2566 select ARCH_WANT_OLD_COMPAT_IPC 2567 ---help--- 2568 Include code to run legacy 32-bit programs under a 2569 64-bit kernel. You should likely turn this on, unless you're 2570 100% sure that you don't have any 32-bit programs left. 2571 2572config IA32_AOUT 2573 tristate "IA32 a.out support" 2574 depends on IA32_EMULATION 2575 ---help--- 2576 Support old a.out binaries in the 32bit emulation. 2577 2578config X86_X32 2579 bool "x32 ABI for 64-bit mode" 2580 depends on X86_64 2581 ---help--- 2582 Include code to run binaries for the x32 native 32-bit ABI 2583 for 64-bit processors. An x32 process gets access to the 2584 full 64-bit register file and wide data path while leaving 2585 pointers at 32 bits for smaller memory footprint. 2586 2587 You will need a recent binutils (2.22 or later) with 2588 elf32_x86_64 support enabled to compile a kernel with this 2589 option set. 2590 2591config COMPAT 2592 def_bool y 2593 depends on IA32_EMULATION || X86_X32 2594 2595if COMPAT 2596config COMPAT_FOR_U64_ALIGNMENT 2597 def_bool y 2598 2599config SYSVIPC_COMPAT 2600 def_bool y 2601 depends on SYSVIPC 2602 2603config KEYS_COMPAT 2604 def_bool y 2605 depends on KEYS 2606endif 2607 2608endmenu 2609 2610 2611config HAVE_ATOMIC_IOMAP 2612 def_bool y 2613 depends on X86_32 2614 2615config X86_DEV_DMA_OPS 2616 bool 2617 depends on X86_64 || STA2X11 2618 2619config X86_DMA_REMAP 2620 bool 2621 depends on STA2X11 2622 2623config PMC_ATOM 2624 def_bool y 2625 depends on PCI 2626 2627source "net/Kconfig" 2628 2629source "drivers/Kconfig" 2630 2631source "drivers/firmware/Kconfig" 2632 2633source "fs/Kconfig" 2634 2635source "arch/x86/Kconfig.debug" 2636 2637source "security/Kconfig" 2638 2639source "crypto/Kconfig" 2640 2641source "arch/x86/kvm/Kconfig" 2642 2643source "lib/Kconfig" 2644