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