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