1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH = "x86_64" 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 !64BIT 11 select CLKSRC_I8253 12 13config X86_64 14 def_bool 64BIT 15 select X86_DEV_DMA_OPS 16 17### Arch settings 18config X86 19 def_bool y 20 select HAVE_AOUT if X86_32 21 select HAVE_UNSTABLE_SCHED_CLOCK 22 select HAVE_IDE 23 select HAVE_OPROFILE 24 select HAVE_PCSPKR_PLATFORM 25 select HAVE_PERF_EVENTS 26 select HAVE_IRQ_WORK 27 select HAVE_IOREMAP_PROT 28 select HAVE_KPROBES 29 select HAVE_MEMBLOCK 30 select HAVE_MEMBLOCK_NODE_MAP 31 select ARCH_DISCARD_MEMBLOCK 32 select ARCH_WANT_OPTIONAL_GPIOLIB 33 select ARCH_WANT_FRAME_POINTERS 34 select HAVE_DMA_ATTRS 35 select HAVE_DMA_CONTIGUOUS if !SWIOTLB 36 select HAVE_KRETPROBES 37 select HAVE_OPTPROBES 38 select HAVE_FTRACE_MCOUNT_RECORD 39 select HAVE_C_RECORDMCOUNT 40 select HAVE_DYNAMIC_FTRACE 41 select HAVE_FUNCTION_TRACER 42 select HAVE_FUNCTION_GRAPH_TRACER 43 select HAVE_FUNCTION_GRAPH_FP_TEST 44 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 45 select HAVE_SYSCALL_TRACEPOINTS 46 select HAVE_KVM 47 select HAVE_ARCH_KGDB 48 select HAVE_ARCH_TRACEHOOK 49 select HAVE_GENERIC_DMA_COHERENT if X86_32 50 select HAVE_EFFICIENT_UNALIGNED_ACCESS 51 select USER_STACKTRACE_SUPPORT 52 select HAVE_REGS_AND_STACK_ACCESS_API 53 select HAVE_DMA_API_DEBUG 54 select HAVE_KERNEL_GZIP 55 select HAVE_KERNEL_BZIP2 56 select HAVE_KERNEL_LZMA 57 select HAVE_KERNEL_XZ 58 select HAVE_KERNEL_LZO 59 select HAVE_HW_BREAKPOINT 60 select HAVE_MIXED_BREAKPOINTS_REGS 61 select PERF_EVENTS 62 select HAVE_PERF_EVENTS_NMI 63 select ANON_INODES 64 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386 65 select HAVE_CMPXCHG_LOCAL if !M386 66 select HAVE_CMPXCHG_DOUBLE 67 select HAVE_ARCH_KMEMCHECK 68 select HAVE_USER_RETURN_NOTIFIER 69 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 70 select HAVE_ARCH_JUMP_LABEL 71 select HAVE_TEXT_POKE_SMP 72 select HAVE_GENERIC_HARDIRQS 73 select SPARSE_IRQ 74 select GENERIC_FIND_FIRST_BIT 75 select GENERIC_IRQ_PROBE 76 select GENERIC_PENDING_IRQ if SMP 77 select GENERIC_IRQ_SHOW 78 select GENERIC_CLOCKEVENTS_MIN_ADJUST 79 select IRQ_FORCED_THREADING 80 select USE_GENERIC_SMP_HELPERS if SMP 81 select HAVE_BPF_JIT if X86_64 82 select CLKEVT_I8253 83 select ARCH_HAVE_NMI_SAFE_CMPXCHG 84 select GENERIC_IOMAP 85 select DCACHE_WORD_ACCESS 86 select GENERIC_SMP_IDLE_THREAD 87 select HAVE_ARCH_SECCOMP_FILTER 88 select BUILDTIME_EXTABLE_SORT 89 select GENERIC_CMOS_UPDATE 90 select CLOCKSOURCE_WATCHDOG 91 select GENERIC_CLOCKEVENTS 92 select ARCH_CLOCKSOURCE_DATA if X86_64 93 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 94 select GENERIC_TIME_VSYSCALL if X86_64 95 select KTIME_SCALAR if X86_32 96 select GENERIC_STRNCPY_FROM_USER 97 select GENERIC_STRNLEN_USER 98 99config INSTRUCTION_DECODER 100 def_bool (KPROBES || PERF_EVENTS || UPROBES) 101 102config OUTPUT_FORMAT 103 string 104 default "elf32-i386" if X86_32 105 default "elf64-x86-64" if X86_64 106 107config ARCH_DEFCONFIG 108 string 109 default "arch/x86/configs/i386_defconfig" if X86_32 110 default "arch/x86/configs/x86_64_defconfig" if X86_64 111 112config LOCKDEP_SUPPORT 113 def_bool y 114 115config STACKTRACE_SUPPORT 116 def_bool y 117 118config HAVE_LATENCYTOP_SUPPORT 119 def_bool y 120 121config MMU 122 def_bool y 123 124config SBUS 125 bool 126 127config NEED_DMA_MAP_STATE 128 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG) 129 130config NEED_SG_DMA_LENGTH 131 def_bool y 132 133config GENERIC_ISA_DMA 134 def_bool ISA_DMA_API 135 136config GENERIC_BUG 137 def_bool y 138 depends on BUG 139 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 140 141config GENERIC_BUG_RELATIVE_POINTERS 142 bool 143 144config GENERIC_HWEIGHT 145 def_bool y 146 147config GENERIC_GPIO 148 bool 149 150config ARCH_MAY_HAVE_PC_FDC 151 def_bool ISA_DMA_API 152 153config RWSEM_GENERIC_SPINLOCK 154 def_bool !X86_XADD 155 156config RWSEM_XCHGADD_ALGORITHM 157 def_bool X86_XADD 158 159config GENERIC_CALIBRATE_DELAY 160 def_bool y 161 162config ARCH_HAS_CPU_RELAX 163 def_bool y 164 165config ARCH_HAS_DEFAULT_IDLE 166 def_bool y 167 168config ARCH_HAS_CACHE_LINE_SIZE 169 def_bool y 170 171config ARCH_HAS_CPU_AUTOPROBE 172 def_bool y 173 174config HAVE_SETUP_PER_CPU_AREA 175 def_bool y 176 177config NEED_PER_CPU_EMBED_FIRST_CHUNK 178 def_bool y 179 180config NEED_PER_CPU_PAGE_FIRST_CHUNK 181 def_bool y 182 183config ARCH_HIBERNATION_POSSIBLE 184 def_bool y 185 186config ARCH_SUSPEND_POSSIBLE 187 def_bool y 188 189config ZONE_DMA32 190 bool 191 default X86_64 192 193config AUDIT_ARCH 194 bool 195 default X86_64 196 197config ARCH_SUPPORTS_OPTIMIZED_INLINING 198 def_bool y 199 200config ARCH_SUPPORTS_DEBUG_PAGEALLOC 201 def_bool y 202 203config HAVE_INTEL_TXT 204 def_bool y 205 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI 206 207config X86_32_SMP 208 def_bool y 209 depends on X86_32 && SMP 210 211config X86_64_SMP 212 def_bool y 213 depends on X86_64 && SMP 214 215config X86_HT 216 def_bool y 217 depends on SMP 218 219config X86_32_LAZY_GS 220 def_bool y 221 depends on X86_32 && !CC_STACKPROTECTOR 222 223config ARCH_HWEIGHT_CFLAGS 224 string 225 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 226 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 227 228config ARCH_CPU_PROBE_RELEASE 229 def_bool y 230 depends on HOTPLUG_CPU 231 232config ARCH_SUPPORTS_UPROBES 233 def_bool y 234 235source "init/Kconfig" 236source "kernel/Kconfig.freezer" 237 238menu "Processor type and features" 239 240config ZONE_DMA 241 bool "DMA memory allocation support" if EXPERT 242 default y 243 help 244 DMA memory allocation support allows devices with less than 32-bit 245 addressing to allocate within the first 16MB of address space. 246 Disable if no such devices will be used. 247 248 If unsure, say Y. 249 250config SMP 251 bool "Symmetric multi-processing support" 252 ---help--- 253 This enables support for systems with more than one CPU. If you have 254 a system with only one CPU, like most personal computers, say N. If 255 you have a system with more than one CPU, say Y. 256 257 If you say N here, the kernel will run on single and multiprocessor 258 machines, but will use only one CPU of a multiprocessor machine. If 259 you say Y here, the kernel will run on many, but not all, 260 singleprocessor machines. On a singleprocessor machine, the kernel 261 will run faster if you say N here. 262 263 Note that if you say Y here and choose architecture "586" or 264 "Pentium" under "Processor family", the kernel will not work on 486 265 architectures. Similarly, multiprocessor kernels for the "PPro" 266 architecture may not work on all Pentium based boards. 267 268 People using multiprocessor machines who say Y here should also say 269 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 270 Management" code will be disabled if you say Y here. 271 272 See also <file:Documentation/x86/i386/IO-APIC.txt>, 273 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 274 <http://www.tldp.org/docs.html#howto>. 275 276 If you don't know what to do here, say N. 277 278config X86_X2APIC 279 bool "Support x2apic" 280 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 281 ---help--- 282 This enables x2apic support on CPUs that have this feature. 283 284 This allows 32-bit apic IDs (so it can support very large systems), 285 and accesses the local apic via MSRs not via mmio. 286 287 If you don't know what to do here, say N. 288 289config X86_MPPARSE 290 bool "Enable MPS table" if ACPI 291 default y 292 depends on X86_LOCAL_APIC 293 ---help--- 294 For old smp systems that do not have proper acpi support. Newer systems 295 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 296 297config X86_BIGSMP 298 bool "Support for big SMP systems with more than 8 CPUs" 299 depends on X86_32 && SMP 300 ---help--- 301 This option is needed for the systems that have more than 8 CPUs 302 303if X86_32 304config X86_EXTENDED_PLATFORM 305 bool "Support for extended (non-PC) x86 platforms" 306 default y 307 ---help--- 308 If you disable this option then the kernel will only support 309 standard PC platforms. (which covers the vast majority of 310 systems out there.) 311 312 If you enable this option then you'll be able to select support 313 for the following (non-PC) 32 bit x86 platforms: 314 AMD Elan 315 NUMAQ (IBM/Sequent) 316 RDC R-321x SoC 317 SGI 320/540 (Visual Workstation) 318 STA2X11-based (e.g. Northville) 319 Summit/EXA (IBM x440) 320 Unisys ES7000 IA32 series 321 Moorestown MID devices 322 323 If you have one of these systems, or if you want to build a 324 generic distribution kernel, say Y here - otherwise say N. 325endif 326 327if X86_64 328config X86_EXTENDED_PLATFORM 329 bool "Support for extended (non-PC) x86 platforms" 330 default y 331 ---help--- 332 If you disable this option then the kernel will only support 333 standard PC platforms. (which covers the vast majority of 334 systems out there.) 335 336 If you enable this option then you'll be able to select support 337 for the following (non-PC) 64 bit x86 platforms: 338 Numascale NumaChip 339 ScaleMP vSMP 340 SGI Ultraviolet 341 342 If you have one of these systems, or if you want to build a 343 generic distribution kernel, say Y here - otherwise say N. 344endif 345# This is an alphabetically sorted list of 64 bit extended platforms 346# Please maintain the alphabetic order if and when there are additions 347config X86_NUMACHIP 348 bool "Numascale NumaChip" 349 depends on X86_64 350 depends on X86_EXTENDED_PLATFORM 351 depends on NUMA 352 depends on SMP 353 depends on X86_X2APIC 354 ---help--- 355 Adds support for Numascale NumaChip large-SMP systems. Needed to 356 enable more than ~168 cores. 357 If you don't have one of these, you should say N here. 358 359config X86_VSMP 360 bool "ScaleMP vSMP" 361 select PARAVIRT_GUEST 362 select PARAVIRT 363 depends on X86_64 && PCI 364 depends on X86_EXTENDED_PLATFORM 365 depends on SMP 366 ---help--- 367 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 368 supposed to run on these EM64T-based machines. Only choose this option 369 if you have one of these machines. 370 371config X86_UV 372 bool "SGI Ultraviolet" 373 depends on X86_64 374 depends on X86_EXTENDED_PLATFORM 375 depends on NUMA 376 depends on X86_X2APIC 377 ---help--- 378 This option is needed in order to support SGI Ultraviolet systems. 379 If you don't have one of these, you should say N here. 380 381# Following is an alphabetically sorted list of 32 bit extended platforms 382# Please maintain the alphabetic order if and when there are additions 383 384config X86_INTEL_CE 385 bool "CE4100 TV platform" 386 depends on PCI 387 depends on PCI_GODIRECT 388 depends on X86_32 389 depends on X86_EXTENDED_PLATFORM 390 select X86_REBOOTFIXUPS 391 select OF 392 select OF_EARLY_FLATTREE 393 select IRQ_DOMAIN 394 ---help--- 395 Select for the Intel CE media processor (CE4100) SOC. 396 This option compiles in support for the CE4100 SOC for settop 397 boxes and media devices. 398 399config X86_WANT_INTEL_MID 400 bool "Intel MID platform support" 401 depends on X86_32 402 depends on X86_EXTENDED_PLATFORM 403 ---help--- 404 Select to build a kernel capable of supporting Intel MID platform 405 systems which do not have the PCI legacy interfaces (Moorestown, 406 Medfield). If you are building for a PC class system say N here. 407 408if X86_WANT_INTEL_MID 409 410config X86_INTEL_MID 411 bool 412 413config X86_MDFLD 414 bool "Medfield MID platform" 415 depends on PCI 416 depends on PCI_GOANY 417 depends on X86_IO_APIC 418 select X86_INTEL_MID 419 select SFI 420 select DW_APB_TIMER 421 select APB_TIMER 422 select I2C 423 select SPI 424 select INTEL_SCU_IPC 425 select X86_PLATFORM_DEVICES 426 select MFD_INTEL_MSIC 427 ---help--- 428 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin 429 Internet Device(MID) platform. 430 Unlike standard x86 PCs, Medfield does not have many legacy devices 431 nor standard legacy replacement devices/features. e.g. Medfield does 432 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 433 434endif 435 436config X86_RDC321X 437 bool "RDC R-321x SoC" 438 depends on X86_32 439 depends on X86_EXTENDED_PLATFORM 440 select M486 441 select X86_REBOOTFIXUPS 442 ---help--- 443 This option is needed for RDC R-321x system-on-chip, also known 444 as R-8610-(G). 445 If you don't have one of these chips, you should say N here. 446 447config X86_32_NON_STANDARD 448 bool "Support non-standard 32-bit SMP architectures" 449 depends on X86_32 && SMP 450 depends on X86_EXTENDED_PLATFORM 451 ---help--- 452 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, 453 STA2X11, default subarchitectures. It is intended for a generic 454 binary kernel. If you select them all, kernel will probe it 455 one by one and will fallback to default. 456 457# Alphabetically sorted list of Non standard 32 bit platforms 458 459config X86_NUMAQ 460 bool "NUMAQ (IBM/Sequent)" 461 depends on X86_32_NON_STANDARD 462 depends on PCI 463 select NUMA 464 select X86_MPPARSE 465 ---help--- 466 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 467 NUMA multiquad box. This changes the way that processors are 468 bootstrapped, and uses Clustered Logical APIC addressing mode instead 469 of Flat Logical. You will need a new lynxer.elf file to flash your 470 firmware with - send email to <Martin.Bligh@us.ibm.com>. 471 472config X86_SUPPORTS_MEMORY_FAILURE 473 def_bool y 474 # MCE code calls memory_failure(): 475 depends on X86_MCE 476 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 477 depends on !X86_NUMAQ 478 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 479 depends on X86_64 || !SPARSEMEM 480 select ARCH_SUPPORTS_MEMORY_FAILURE 481 482config X86_VISWS 483 bool "SGI 320/540 (Visual Workstation)" 484 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 485 depends on X86_32_NON_STANDARD 486 ---help--- 487 The SGI Visual Workstation series is an IA32-based workstation 488 based on SGI systems chips with some legacy PC hardware attached. 489 490 Say Y here to create a kernel to run on the SGI 320 or 540. 491 492 A kernel compiled for the Visual Workstation will run on general 493 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 494 495config STA2X11 496 bool "STA2X11 Companion Chip Support" 497 depends on X86_32_NON_STANDARD && PCI 498 select X86_DEV_DMA_OPS 499 select X86_DMA_REMAP 500 select SWIOTLB 501 select MFD_STA2X11 502 select ARCH_REQUIRE_GPIOLIB 503 default n 504 ---help--- 505 This adds support for boards based on the STA2X11 IO-Hub, 506 a.k.a. "ConneXt". The chip is used in place of the standard 507 PC chipset, so all "standard" peripherals are missing. If this 508 option is selected the kernel will still be able to boot on 509 standard PC machines. 510 511config X86_SUMMIT 512 bool "Summit/EXA (IBM x440)" 513 depends on X86_32_NON_STANDARD 514 ---help--- 515 This option is needed for IBM systems that use the Summit/EXA chipset. 516 In particular, it is needed for the x440. 517 518config X86_ES7000 519 bool "Unisys ES7000 IA32 series" 520 depends on X86_32_NON_STANDARD && X86_BIGSMP 521 ---help--- 522 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 523 supposed to run on an IA32-based Unisys ES7000 system. 524 525config X86_32_IRIS 526 tristate "Eurobraille/Iris poweroff module" 527 depends on X86_32 528 ---help--- 529 The Iris machines from EuroBraille do not have APM or ACPI support 530 to shut themselves down properly. A special I/O sequence is 531 needed to do so, which is what this module does at 532 kernel shutdown. 533 534 This is only for Iris machines from EuroBraille. 535 536 If unused, say N. 537 538config SCHED_OMIT_FRAME_POINTER 539 def_bool y 540 prompt "Single-depth WCHAN output" 541 depends on X86 542 ---help--- 543 Calculate simpler /proc/<PID>/wchan values. If this option 544 is disabled then wchan values will recurse back to the 545 caller function. This provides more accurate wchan values, 546 at the expense of slightly more scheduling overhead. 547 548 If in doubt, say "Y". 549 550menuconfig PARAVIRT_GUEST 551 bool "Paravirtualized guest support" 552 ---help--- 553 Say Y here to get to see options related to running Linux under 554 various hypervisors. This option alone does not add any kernel code. 555 556 If you say N, all options in this submenu will be skipped and disabled. 557 558if PARAVIRT_GUEST 559 560config PARAVIRT_TIME_ACCOUNTING 561 bool "Paravirtual steal time accounting" 562 select PARAVIRT 563 default n 564 ---help--- 565 Select this option to enable fine granularity task steal time 566 accounting. Time spent executing other tasks in parallel with 567 the current vCPU is discounted from the vCPU power. To account for 568 that, there can be a small performance impact. 569 570 If in doubt, say N here. 571 572source "arch/x86/xen/Kconfig" 573 574config KVM_CLOCK 575 bool "KVM paravirtualized clock" 576 select PARAVIRT 577 select PARAVIRT_CLOCK 578 ---help--- 579 Turning on this option will allow you to run a paravirtualized clock 580 when running over the KVM hypervisor. Instead of relying on a PIT 581 (or probably other) emulation by the underlying device model, the host 582 provides the guest with timing infrastructure such as time of day, and 583 system time 584 585config KVM_GUEST 586 bool "KVM Guest support" 587 select PARAVIRT 588 ---help--- 589 This option enables various optimizations for running under the KVM 590 hypervisor. 591 592source "arch/x86/lguest/Kconfig" 593 594config PARAVIRT 595 bool "Enable paravirtualization code" 596 ---help--- 597 This changes the kernel so it can modify itself when it is run 598 under a hypervisor, potentially improving performance significantly 599 over full virtualization. However, when run without a hypervisor 600 the kernel is theoretically slower and slightly larger. 601 602config PARAVIRT_SPINLOCKS 603 bool "Paravirtualization layer for spinlocks" 604 depends on PARAVIRT && SMP && EXPERIMENTAL 605 ---help--- 606 Paravirtualized spinlocks allow a pvops backend to replace the 607 spinlock implementation with something virtualization-friendly 608 (for example, block the virtual CPU rather than spinning). 609 610 Unfortunately the downside is an up to 5% performance hit on 611 native kernels, with various workloads. 612 613 If you are unsure how to answer this question, answer N. 614 615config PARAVIRT_CLOCK 616 bool 617 618endif 619 620config PARAVIRT_DEBUG 621 bool "paravirt-ops debugging" 622 depends on PARAVIRT && DEBUG_KERNEL 623 ---help--- 624 Enable to debug paravirt_ops internals. Specifically, BUG if 625 a paravirt_op is missing when it is called. 626 627config NO_BOOTMEM 628 def_bool y 629 630config MEMTEST 631 bool "Memtest" 632 ---help--- 633 This option adds a kernel parameter 'memtest', which allows memtest 634 to be set. 635 memtest=0, mean disabled; -- default 636 memtest=1, mean do 1 test pattern; 637 ... 638 memtest=4, mean do 4 test patterns. 639 If you are unsure how to answer this question, answer N. 640 641config X86_SUMMIT_NUMA 642 def_bool y 643 depends on X86_32 && NUMA && X86_32_NON_STANDARD 644 645config X86_CYCLONE_TIMER 646 def_bool y 647 depends on X86_SUMMIT 648 649source "arch/x86/Kconfig.cpu" 650 651config HPET_TIMER 652 def_bool X86_64 653 prompt "HPET Timer Support" if X86_32 654 ---help--- 655 Use the IA-PC HPET (High Precision Event Timer) to manage 656 time in preference to the PIT and RTC, if a HPET is 657 present. 658 HPET is the next generation timer replacing legacy 8254s. 659 The HPET provides a stable time base on SMP 660 systems, unlike the TSC, but it is more expensive to access, 661 as it is off-chip. You can find the HPET spec at 662 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 663 664 You can safely choose Y here. However, HPET will only be 665 activated if the platform and the BIOS support this feature. 666 Otherwise the 8254 will be used for timing services. 667 668 Choose N to continue using the legacy 8254 timer. 669 670config HPET_EMULATE_RTC 671 def_bool y 672 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 673 674config APB_TIMER 675 def_bool y if X86_INTEL_MID 676 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 677 select DW_APB_TIMER 678 depends on X86_INTEL_MID && SFI 679 help 680 APB timer is the replacement for 8254, HPET on X86 MID platforms. 681 The APBT provides a stable time base on SMP 682 systems, unlike the TSC, but it is more expensive to access, 683 as it is off-chip. APB timers are always running regardless of CPU 684 C states, they are used as per CPU clockevent device when possible. 685 686# Mark as expert because too many people got it wrong. 687# The code disables itself when not needed. 688config DMI 689 default y 690 bool "Enable DMI scanning" if EXPERT 691 ---help--- 692 Enabled scanning of DMI to identify machine quirks. Say Y 693 here unless you have verified that your setup is not 694 affected by entries in the DMI blacklist. Required by PNP 695 BIOS code. 696 697config GART_IOMMU 698 bool "GART IOMMU support" if EXPERT 699 default y 700 select SWIOTLB 701 depends on X86_64 && PCI && AMD_NB 702 ---help--- 703 Support for full DMA access of devices with 32bit memory access only 704 on systems with more than 3GB. This is usually needed for USB, 705 sound, many IDE/SATA chipsets and some other devices. 706 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 707 based hardware IOMMU and a software bounce buffer based IOMMU used 708 on Intel systems and as fallback. 709 The code is only active when needed (enough memory and limited 710 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 711 too. 712 713config CALGARY_IOMMU 714 bool "IBM Calgary IOMMU support" 715 select SWIOTLB 716 depends on X86_64 && PCI && EXPERIMENTAL 717 ---help--- 718 Support for hardware IOMMUs in IBM's xSeries x366 and x460 719 systems. Needed to run systems with more than 3GB of memory 720 properly with 32-bit PCI devices that do not support DAC 721 (Double Address Cycle). Calgary also supports bus level 722 isolation, where all DMAs pass through the IOMMU. This 723 prevents them from going anywhere except their intended 724 destination. This catches hard-to-find kernel bugs and 725 mis-behaving drivers and devices that do not use the DMA-API 726 properly to set up their DMA buffers. The IOMMU can be 727 turned off at boot time with the iommu=off parameter. 728 Normally the kernel will make the right choice by itself. 729 If unsure, say Y. 730 731config CALGARY_IOMMU_ENABLED_BY_DEFAULT 732 def_bool y 733 prompt "Should Calgary be enabled by default?" 734 depends on CALGARY_IOMMU 735 ---help--- 736 Should Calgary be enabled by default? if you choose 'y', Calgary 737 will be used (if it exists). If you choose 'n', Calgary will not be 738 used even if it exists. If you choose 'n' and would like to use 739 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 740 If unsure, say Y. 741 742# need this always selected by IOMMU for the VIA workaround 743config SWIOTLB 744 def_bool y if X86_64 745 ---help--- 746 Support for software bounce buffers used on x86-64 systems 747 which don't have a hardware IOMMU (e.g. the current generation 748 of Intel's x86-64 CPUs). Using this PCI devices which can only 749 access 32-bits of memory can be used on systems with more than 750 3 GB of memory. If unsure, say Y. 751 752config IOMMU_HELPER 753 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU) 754 755config MAXSMP 756 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 757 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL 758 select CPUMASK_OFFSTACK 759 ---help--- 760 Enable maximum number of CPUS and NUMA Nodes for this architecture. 761 If unsure, say N. 762 763config NR_CPUS 764 int "Maximum number of CPUs" if SMP && !MAXSMP 765 range 2 8 if SMP && X86_32 && !X86_BIGSMP 766 range 2 512 if SMP && !MAXSMP 767 default "1" if !SMP 768 default "4096" if MAXSMP 769 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 770 default "8" if SMP 771 ---help--- 772 This allows you to specify the maximum number of CPUs which this 773 kernel will support. The maximum supported value is 512 and the 774 minimum value which makes sense is 2. 775 776 This is purely to save memory - each supported CPU adds 777 approximately eight kilobytes to the kernel image. 778 779config SCHED_SMT 780 bool "SMT (Hyperthreading) scheduler support" 781 depends on X86_HT 782 ---help--- 783 SMT scheduler support improves the CPU scheduler's decision making 784 when dealing with Intel Pentium 4 chips with HyperThreading at a 785 cost of slightly increased overhead in some places. If unsure say 786 N here. 787 788config SCHED_MC 789 def_bool y 790 prompt "Multi-core scheduler support" 791 depends on X86_HT 792 ---help--- 793 Multi-core scheduler support improves the CPU scheduler's decision 794 making when dealing with multi-core CPU chips at a cost of slightly 795 increased overhead in some places. If unsure say N here. 796 797config IRQ_TIME_ACCOUNTING 798 bool "Fine granularity task level IRQ time accounting" 799 default n 800 ---help--- 801 Select this option to enable fine granularity task irq time 802 accounting. This is done by reading a timestamp on each 803 transitions between softirq and hardirq state, so there can be a 804 small performance impact. 805 806 If in doubt, say N here. 807 808source "kernel/Kconfig.preempt" 809 810config X86_UP_APIC 811 bool "Local APIC support on uniprocessors" 812 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 813 ---help--- 814 A local APIC (Advanced Programmable Interrupt Controller) is an 815 integrated interrupt controller in the CPU. If you have a single-CPU 816 system which has a processor with a local APIC, you can say Y here to 817 enable and use it. If you say Y here even though your machine doesn't 818 have a local APIC, then the kernel will still run with no slowdown at 819 all. The local APIC supports CPU-generated self-interrupts (timer, 820 performance counters), and the NMI watchdog which detects hard 821 lockups. 822 823config X86_UP_IOAPIC 824 bool "IO-APIC support on uniprocessors" 825 depends on X86_UP_APIC 826 ---help--- 827 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 828 SMP-capable replacement for PC-style interrupt controllers. Most 829 SMP systems and many recent uniprocessor systems have one. 830 831 If you have a single-CPU system with an IO-APIC, you can say Y here 832 to use it. If you say Y here even though your machine doesn't have 833 an IO-APIC, then the kernel will still run with no slowdown at all. 834 835config X86_LOCAL_APIC 836 def_bool y 837 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 838 839config X86_IO_APIC 840 def_bool y 841 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC 842 843config X86_VISWS_APIC 844 def_bool y 845 depends on X86_32 && X86_VISWS 846 847config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 848 bool "Reroute for broken boot IRQs" 849 depends on X86_IO_APIC 850 ---help--- 851 This option enables a workaround that fixes a source of 852 spurious interrupts. This is recommended when threaded 853 interrupt handling is used on systems where the generation of 854 superfluous "boot interrupts" cannot be disabled. 855 856 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 857 entry in the chipset's IO-APIC is masked (as, e.g. the RT 858 kernel does during interrupt handling). On chipsets where this 859 boot IRQ generation cannot be disabled, this workaround keeps 860 the original IRQ line masked so that only the equivalent "boot 861 IRQ" is delivered to the CPUs. The workaround also tells the 862 kernel to set up the IRQ handler on the boot IRQ line. In this 863 way only one interrupt is delivered to the kernel. Otherwise 864 the spurious second interrupt may cause the kernel to bring 865 down (vital) interrupt lines. 866 867 Only affects "broken" chipsets. Interrupt sharing may be 868 increased on these systems. 869 870config X86_MCE 871 bool "Machine Check / overheating reporting" 872 ---help--- 873 Machine Check support allows the processor to notify the 874 kernel if it detects a problem (e.g. overheating, data corruption). 875 The action the kernel takes depends on the severity of the problem, 876 ranging from warning messages to halting the machine. 877 878config X86_MCE_INTEL 879 def_bool y 880 prompt "Intel MCE features" 881 depends on X86_MCE && X86_LOCAL_APIC 882 ---help--- 883 Additional support for intel specific MCE features such as 884 the thermal monitor. 885 886config X86_MCE_AMD 887 def_bool y 888 prompt "AMD MCE features" 889 depends on X86_MCE && X86_LOCAL_APIC 890 ---help--- 891 Additional support for AMD specific MCE features such as 892 the DRAM Error Threshold. 893 894config X86_ANCIENT_MCE 895 bool "Support for old Pentium 5 / WinChip machine checks" 896 depends on X86_32 && X86_MCE 897 ---help--- 898 Include support for machine check handling on old Pentium 5 or WinChip 899 systems. These typically need to be enabled explicitely on the command 900 line. 901 902config X86_MCE_THRESHOLD 903 depends on X86_MCE_AMD || X86_MCE_INTEL 904 def_bool y 905 906config X86_MCE_INJECT 907 depends on X86_MCE 908 tristate "Machine check injector support" 909 ---help--- 910 Provide support for injecting machine checks for testing purposes. 911 If you don't know what a machine check is and you don't do kernel 912 QA it is safe to say n. 913 914config X86_THERMAL_VECTOR 915 def_bool y 916 depends on X86_MCE_INTEL 917 918config VM86 919 bool "Enable VM86 support" if EXPERT 920 default y 921 depends on X86_32 922 ---help--- 923 This option is required by programs like DOSEMU to run 16-bit legacy 924 code on X86 processors. It also may be needed by software like 925 XFree86 to initialize some video cards via BIOS. Disabling this 926 option saves about 6k. 927 928config TOSHIBA 929 tristate "Toshiba Laptop support" 930 depends on X86_32 931 ---help--- 932 This adds a driver to safely access the System Management Mode of 933 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 934 not work on models with a Phoenix BIOS. The System Management Mode 935 is used to set the BIOS and power saving options on Toshiba portables. 936 937 For information on utilities to make use of this driver see the 938 Toshiba Linux utilities web site at: 939 <http://www.buzzard.org.uk/toshiba/>. 940 941 Say Y if you intend to run this kernel on a Toshiba portable. 942 Say N otherwise. 943 944config I8K 945 tristate "Dell laptop support" 946 select HWMON 947 ---help--- 948 This adds a driver to safely access the System Management Mode 949 of the CPU on the Dell Inspiron 8000. The System Management Mode 950 is used to read cpu temperature and cooling fan status and to 951 control the fans on the I8K portables. 952 953 This driver has been tested only on the Inspiron 8000 but it may 954 also work with other Dell laptops. You can force loading on other 955 models by passing the parameter `force=1' to the module. Use at 956 your own risk. 957 958 For information on utilities to make use of this driver see the 959 I8K Linux utilities web site at: 960 <http://people.debian.org/~dz/i8k/> 961 962 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 963 Say N otherwise. 964 965config X86_REBOOTFIXUPS 966 bool "Enable X86 board specific fixups for reboot" 967 depends on X86_32 968 ---help--- 969 This enables chipset and/or board specific fixups to be done 970 in order to get reboot to work correctly. This is only needed on 971 some combinations of hardware and BIOS. The symptom, for which 972 this config is intended, is when reboot ends with a stalled/hung 973 system. 974 975 Currently, the only fixup is for the Geode machines using 976 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 977 978 Say Y if you want to enable the fixup. Currently, it's safe to 979 enable this option even if you don't need it. 980 Say N otherwise. 981 982config MICROCODE 983 tristate "/dev/cpu/microcode - microcode support" 984 select FW_LOADER 985 ---help--- 986 If you say Y here, you will be able to update the microcode on 987 certain Intel and AMD processors. The Intel support is for the 988 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, 989 Pentium 4, Xeon etc. The AMD support is for family 0x10 and 990 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra. 991 You will obviously need the actual microcode binary data itself 992 which is not shipped with the Linux kernel. 993 994 This option selects the general module only, you need to select 995 at least one vendor specific module as well. 996 997 To compile this driver as a module, choose M here: the 998 module will be called microcode. 999 1000config MICROCODE_INTEL 1001 bool "Intel microcode patch loading support" 1002 depends on MICROCODE 1003 default MICROCODE 1004 select FW_LOADER 1005 ---help--- 1006 This options enables microcode patch loading support for Intel 1007 processors. 1008 1009 For latest news and information on obtaining all the required 1010 Intel ingredients for this driver, check: 1011 <http://www.urbanmyth.org/microcode/>. 1012 1013config MICROCODE_AMD 1014 bool "AMD microcode patch loading support" 1015 depends on MICROCODE 1016 select FW_LOADER 1017 ---help--- 1018 If you select this option, microcode patch loading support for AMD 1019 processors will be enabled. 1020 1021config MICROCODE_OLD_INTERFACE 1022 def_bool y 1023 depends on MICROCODE 1024 1025config X86_MSR 1026 tristate "/dev/cpu/*/msr - Model-specific register support" 1027 ---help--- 1028 This device gives privileged processes access to the x86 1029 Model-Specific Registers (MSRs). It is a character device with 1030 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1031 MSR accesses are directed to a specific CPU on multi-processor 1032 systems. 1033 1034config X86_CPUID 1035 tristate "/dev/cpu/*/cpuid - CPU information support" 1036 ---help--- 1037 This device gives processes access to the x86 CPUID instruction to 1038 be executed on a specific processor. It is a character device 1039 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1040 /dev/cpu/31/cpuid. 1041 1042choice 1043 prompt "High Memory Support" 1044 default HIGHMEM64G if X86_NUMAQ 1045 default HIGHMEM4G 1046 depends on X86_32 1047 1048config NOHIGHMEM 1049 bool "off" 1050 depends on !X86_NUMAQ 1051 ---help--- 1052 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1053 However, the address space of 32-bit x86 processors is only 4 1054 Gigabytes large. That means that, if you have a large amount of 1055 physical memory, not all of it can be "permanently mapped" by the 1056 kernel. The physical memory that's not permanently mapped is called 1057 "high memory". 1058 1059 If you are compiling a kernel which will never run on a machine with 1060 more than 1 Gigabyte total physical RAM, answer "off" here (default 1061 choice and suitable for most users). This will result in a "3GB/1GB" 1062 split: 3GB are mapped so that each process sees a 3GB virtual memory 1063 space and the remaining part of the 4GB virtual memory space is used 1064 by the kernel to permanently map as much physical memory as 1065 possible. 1066 1067 If the machine has between 1 and 4 Gigabytes physical RAM, then 1068 answer "4GB" here. 1069 1070 If more than 4 Gigabytes is used then answer "64GB" here. This 1071 selection turns Intel PAE (Physical Address Extension) mode on. 1072 PAE implements 3-level paging on IA32 processors. PAE is fully 1073 supported by Linux, PAE mode is implemented on all recent Intel 1074 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1075 then the kernel will not boot on CPUs that don't support PAE! 1076 1077 The actual amount of total physical memory will either be 1078 auto detected or can be forced by using a kernel command line option 1079 such as "mem=256M". (Try "man bootparam" or see the documentation of 1080 your boot loader (lilo or loadlin) about how to pass options to the 1081 kernel at boot time.) 1082 1083 If unsure, say "off". 1084 1085config HIGHMEM4G 1086 bool "4GB" 1087 depends on !X86_NUMAQ 1088 ---help--- 1089 Select this if you have a 32-bit processor and between 1 and 4 1090 gigabytes of physical RAM. 1091 1092config HIGHMEM64G 1093 bool "64GB" 1094 depends on !M386 && !M486 1095 select X86_PAE 1096 ---help--- 1097 Select this if you have a 32-bit processor and more than 4 1098 gigabytes of physical RAM. 1099 1100endchoice 1101 1102choice 1103 depends on EXPERIMENTAL 1104 prompt "Memory split" if EXPERT 1105 default VMSPLIT_3G 1106 depends on X86_32 1107 ---help--- 1108 Select the desired split between kernel and user memory. 1109 1110 If the address range available to the kernel is less than the 1111 physical memory installed, the remaining memory will be available 1112 as "high memory". Accessing high memory is a little more costly 1113 than low memory, as it needs to be mapped into the kernel first. 1114 Note that increasing the kernel address space limits the range 1115 available to user programs, making the address space there 1116 tighter. Selecting anything other than the default 3G/1G split 1117 will also likely make your kernel incompatible with binary-only 1118 kernel modules. 1119 1120 If you are not absolutely sure what you are doing, leave this 1121 option alone! 1122 1123 config VMSPLIT_3G 1124 bool "3G/1G user/kernel split" 1125 config VMSPLIT_3G_OPT 1126 depends on !X86_PAE 1127 bool "3G/1G user/kernel split (for full 1G low memory)" 1128 config VMSPLIT_2G 1129 bool "2G/2G user/kernel split" 1130 config VMSPLIT_2G_OPT 1131 depends on !X86_PAE 1132 bool "2G/2G user/kernel split (for full 2G low memory)" 1133 config VMSPLIT_1G 1134 bool "1G/3G user/kernel split" 1135endchoice 1136 1137config PAGE_OFFSET 1138 hex 1139 default 0xB0000000 if VMSPLIT_3G_OPT 1140 default 0x80000000 if VMSPLIT_2G 1141 default 0x78000000 if VMSPLIT_2G_OPT 1142 default 0x40000000 if VMSPLIT_1G 1143 default 0xC0000000 1144 depends on X86_32 1145 1146config HIGHMEM 1147 def_bool y 1148 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1149 1150config X86_PAE 1151 bool "PAE (Physical Address Extension) Support" 1152 depends on X86_32 && !HIGHMEM4G 1153 ---help--- 1154 PAE is required for NX support, and furthermore enables 1155 larger swapspace support for non-overcommit purposes. It 1156 has the cost of more pagetable lookup overhead, and also 1157 consumes more pagetable space per process. 1158 1159config ARCH_PHYS_ADDR_T_64BIT 1160 def_bool X86_64 || X86_PAE 1161 1162config ARCH_DMA_ADDR_T_64BIT 1163 def_bool X86_64 || HIGHMEM64G 1164 1165config DIRECT_GBPAGES 1166 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1167 default y 1168 depends on X86_64 1169 ---help--- 1170 Allow the kernel linear mapping to use 1GB pages on CPUs that 1171 support it. This can improve the kernel's performance a tiny bit by 1172 reducing TLB pressure. If in doubt, say "Y". 1173 1174# Common NUMA Features 1175config NUMA 1176 bool "Numa Memory Allocation and Scheduler Support" 1177 depends on SMP 1178 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL) 1179 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1180 ---help--- 1181 Enable NUMA (Non Uniform Memory Access) support. 1182 1183 The kernel will try to allocate memory used by a CPU on the 1184 local memory controller of the CPU and add some more 1185 NUMA awareness to the kernel. 1186 1187 For 64-bit this is recommended if the system is Intel Core i7 1188 (or later), AMD Opteron, or EM64T NUMA. 1189 1190 For 32-bit this is only needed on (rare) 32-bit-only platforms 1191 that support NUMA topologies, such as NUMAQ / Summit, or if you 1192 boot a 32-bit kernel on a 64-bit NUMA platform. 1193 1194 Otherwise, you should say N. 1195 1196comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1197 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1198 1199config AMD_NUMA 1200 def_bool y 1201 prompt "Old style AMD Opteron NUMA detection" 1202 depends on X86_64 && NUMA && PCI 1203 ---help--- 1204 Enable AMD NUMA node topology detection. You should say Y here if 1205 you have a multi processor AMD system. This uses an old method to 1206 read the NUMA configuration directly from the builtin Northbridge 1207 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1208 which also takes priority if both are compiled in. 1209 1210config X86_64_ACPI_NUMA 1211 def_bool y 1212 prompt "ACPI NUMA detection" 1213 depends on X86_64 && NUMA && ACPI && PCI 1214 select ACPI_NUMA 1215 ---help--- 1216 Enable ACPI SRAT based node topology detection. 1217 1218# Some NUMA nodes have memory ranges that span 1219# other nodes. Even though a pfn is valid and 1220# between a node's start and end pfns, it may not 1221# reside on that node. See memmap_init_zone() 1222# for details. 1223config NODES_SPAN_OTHER_NODES 1224 def_bool y 1225 depends on X86_64_ACPI_NUMA 1226 1227config NUMA_EMU 1228 bool "NUMA emulation" 1229 depends on NUMA 1230 ---help--- 1231 Enable NUMA emulation. A flat machine will be split 1232 into virtual nodes when booted with "numa=fake=N", where N is the 1233 number of nodes. This is only useful for debugging. 1234 1235config NODES_SHIFT 1236 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1237 range 1 10 1238 default "10" if MAXSMP 1239 default "6" if X86_64 1240 default "4" if X86_NUMAQ 1241 default "3" 1242 depends on NEED_MULTIPLE_NODES 1243 ---help--- 1244 Specify the maximum number of NUMA Nodes available on the target 1245 system. Increases memory reserved to accommodate various tables. 1246 1247config HAVE_ARCH_ALLOC_REMAP 1248 def_bool y 1249 depends on X86_32 && NUMA 1250 1251config ARCH_HAVE_MEMORY_PRESENT 1252 def_bool y 1253 depends on X86_32 && DISCONTIGMEM 1254 1255config NEED_NODE_MEMMAP_SIZE 1256 def_bool y 1257 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1258 1259config ARCH_FLATMEM_ENABLE 1260 def_bool y 1261 depends on X86_32 && !NUMA 1262 1263config ARCH_DISCONTIGMEM_ENABLE 1264 def_bool y 1265 depends on NUMA && X86_32 1266 1267config ARCH_DISCONTIGMEM_DEFAULT 1268 def_bool y 1269 depends on NUMA && X86_32 1270 1271config ARCH_SPARSEMEM_ENABLE 1272 def_bool y 1273 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD 1274 select SPARSEMEM_STATIC if X86_32 1275 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1276 1277config ARCH_SPARSEMEM_DEFAULT 1278 def_bool y 1279 depends on X86_64 1280 1281config ARCH_SELECT_MEMORY_MODEL 1282 def_bool y 1283 depends on ARCH_SPARSEMEM_ENABLE 1284 1285config ARCH_MEMORY_PROBE 1286 def_bool X86_64 1287 depends on MEMORY_HOTPLUG 1288 1289config ARCH_PROC_KCORE_TEXT 1290 def_bool y 1291 depends on X86_64 && PROC_KCORE 1292 1293config ILLEGAL_POINTER_VALUE 1294 hex 1295 default 0 if X86_32 1296 default 0xdead000000000000 if X86_64 1297 1298source "mm/Kconfig" 1299 1300config HIGHPTE 1301 bool "Allocate 3rd-level pagetables from highmem" 1302 depends on HIGHMEM 1303 ---help--- 1304 The VM uses one page table entry for each page of physical memory. 1305 For systems with a lot of RAM, this can be wasteful of precious 1306 low memory. Setting this option will put user-space page table 1307 entries in high memory. 1308 1309config X86_CHECK_BIOS_CORRUPTION 1310 bool "Check for low memory corruption" 1311 ---help--- 1312 Periodically check for memory corruption in low memory, which 1313 is suspected to be caused by BIOS. Even when enabled in the 1314 configuration, it is disabled at runtime. Enable it by 1315 setting "memory_corruption_check=1" on the kernel command 1316 line. By default it scans the low 64k of memory every 60 1317 seconds; see the memory_corruption_check_size and 1318 memory_corruption_check_period parameters in 1319 Documentation/kernel-parameters.txt to adjust this. 1320 1321 When enabled with the default parameters, this option has 1322 almost no overhead, as it reserves a relatively small amount 1323 of memory and scans it infrequently. It both detects corruption 1324 and prevents it from affecting the running system. 1325 1326 It is, however, intended as a diagnostic tool; if repeatable 1327 BIOS-originated corruption always affects the same memory, 1328 you can use memmap= to prevent the kernel from using that 1329 memory. 1330 1331config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1332 bool "Set the default setting of memory_corruption_check" 1333 depends on X86_CHECK_BIOS_CORRUPTION 1334 default y 1335 ---help--- 1336 Set whether the default state of memory_corruption_check is 1337 on or off. 1338 1339config X86_RESERVE_LOW 1340 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1341 default 64 1342 range 4 640 1343 ---help--- 1344 Specify the amount of low memory to reserve for the BIOS. 1345 1346 The first page contains BIOS data structures that the kernel 1347 must not use, so that page must always be reserved. 1348 1349 By default we reserve the first 64K of physical RAM, as a 1350 number of BIOSes are known to corrupt that memory range 1351 during events such as suspend/resume or monitor cable 1352 insertion, so it must not be used by the kernel. 1353 1354 You can set this to 4 if you are absolutely sure that you 1355 trust the BIOS to get all its memory reservations and usages 1356 right. If you know your BIOS have problems beyond the 1357 default 64K area, you can set this to 640 to avoid using the 1358 entire low memory range. 1359 1360 If you have doubts about the BIOS (e.g. suspend/resume does 1361 not work or there's kernel crashes after certain hardware 1362 hotplug events) then you might want to enable 1363 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1364 typical corruption patterns. 1365 1366 Leave this to the default value of 64 if you are unsure. 1367 1368config MATH_EMULATION 1369 bool 1370 prompt "Math emulation" if X86_32 1371 ---help--- 1372 Linux can emulate a math coprocessor (used for floating point 1373 operations) if you don't have one. 486DX and Pentium processors have 1374 a math coprocessor built in, 486SX and 386 do not, unless you added 1375 a 487DX or 387, respectively. (The messages during boot time can 1376 give you some hints here ["man dmesg"].) Everyone needs either a 1377 coprocessor or this emulation. 1378 1379 If you don't have a math coprocessor, you need to say Y here; if you 1380 say Y here even though you have a coprocessor, the coprocessor will 1381 be used nevertheless. (This behavior can be changed with the kernel 1382 command line option "no387", which comes handy if your coprocessor 1383 is broken. Try "man bootparam" or see the documentation of your boot 1384 loader (lilo or loadlin) about how to pass options to the kernel at 1385 boot time.) This means that it is a good idea to say Y here if you 1386 intend to use this kernel on different machines. 1387 1388 More information about the internals of the Linux math coprocessor 1389 emulation can be found in <file:arch/x86/math-emu/README>. 1390 1391 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1392 kernel, it won't hurt. 1393 1394config MTRR 1395 def_bool y 1396 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1397 ---help--- 1398 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1399 the Memory Type Range Registers (MTRRs) may be used to control 1400 processor access to memory ranges. This is most useful if you have 1401 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1402 allows bus write transfers to be combined into a larger transfer 1403 before bursting over the PCI/AGP bus. This can increase performance 1404 of image write operations 2.5 times or more. Saying Y here creates a 1405 /proc/mtrr file which may be used to manipulate your processor's 1406 MTRRs. Typically the X server should use this. 1407 1408 This code has a reasonably generic interface so that similar 1409 control registers on other processors can be easily supported 1410 as well: 1411 1412 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1413 Registers (ARRs) which provide a similar functionality to MTRRs. For 1414 these, the ARRs are used to emulate the MTRRs. 1415 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1416 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1417 write-combining. All of these processors are supported by this code 1418 and it makes sense to say Y here if you have one of them. 1419 1420 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1421 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1422 can lead to all sorts of problems, so it's good to say Y here. 1423 1424 You can safely say Y even if your machine doesn't have MTRRs, you'll 1425 just add about 9 KB to your kernel. 1426 1427 See <file:Documentation/x86/mtrr.txt> for more information. 1428 1429config MTRR_SANITIZER 1430 def_bool y 1431 prompt "MTRR cleanup support" 1432 depends on MTRR 1433 ---help--- 1434 Convert MTRR layout from continuous to discrete, so X drivers can 1435 add writeback entries. 1436 1437 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1438 The largest mtrr entry size for a continuous block can be set with 1439 mtrr_chunk_size. 1440 1441 If unsure, say Y. 1442 1443config MTRR_SANITIZER_ENABLE_DEFAULT 1444 int "MTRR cleanup enable value (0-1)" 1445 range 0 1 1446 default "0" 1447 depends on MTRR_SANITIZER 1448 ---help--- 1449 Enable mtrr cleanup default value 1450 1451config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1452 int "MTRR cleanup spare reg num (0-7)" 1453 range 0 7 1454 default "1" 1455 depends on MTRR_SANITIZER 1456 ---help--- 1457 mtrr cleanup spare entries default, it can be changed via 1458 mtrr_spare_reg_nr=N on the kernel command line. 1459 1460config X86_PAT 1461 def_bool y 1462 prompt "x86 PAT support" if EXPERT 1463 depends on MTRR 1464 ---help--- 1465 Use PAT attributes to setup page level cache control. 1466 1467 PATs are the modern equivalents of MTRRs and are much more 1468 flexible than MTRRs. 1469 1470 Say N here if you see bootup problems (boot crash, boot hang, 1471 spontaneous reboots) or a non-working video driver. 1472 1473 If unsure, say Y. 1474 1475config ARCH_USES_PG_UNCACHED 1476 def_bool y 1477 depends on X86_PAT 1478 1479config ARCH_RANDOM 1480 def_bool y 1481 prompt "x86 architectural random number generator" if EXPERT 1482 ---help--- 1483 Enable the x86 architectural RDRAND instruction 1484 (Intel Bull Mountain technology) to generate random numbers. 1485 If supported, this is a high bandwidth, cryptographically 1486 secure hardware random number generator. 1487 1488config EFI 1489 bool "EFI runtime service support" 1490 depends on ACPI 1491 ---help--- 1492 This enables the kernel to use EFI runtime services that are 1493 available (such as the EFI variable services). 1494 1495 This option is only useful on systems that have EFI firmware. 1496 In addition, you should use the latest ELILO loader available 1497 at <http://elilo.sourceforge.net> in order to take advantage 1498 of EFI runtime services. However, even with this option, the 1499 resultant kernel should continue to boot on existing non-EFI 1500 platforms. 1501 1502config EFI_STUB 1503 bool "EFI stub support" 1504 depends on EFI 1505 ---help--- 1506 This kernel feature allows a bzImage to be loaded directly 1507 by EFI firmware without the use of a bootloader. 1508 1509 See Documentation/x86/efi-stub.txt for more information. 1510 1511config SECCOMP 1512 def_bool y 1513 prompt "Enable seccomp to safely compute untrusted bytecode" 1514 ---help--- 1515 This kernel feature is useful for number crunching applications 1516 that may need to compute untrusted bytecode during their 1517 execution. By using pipes or other transports made available to 1518 the process as file descriptors supporting the read/write 1519 syscalls, it's possible to isolate those applications in 1520 their own address space using seccomp. Once seccomp is 1521 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1522 and the task is only allowed to execute a few safe syscalls 1523 defined by each seccomp mode. 1524 1525 If unsure, say Y. Only embedded should say N here. 1526 1527config CC_STACKPROTECTOR 1528 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" 1529 ---help--- 1530 This option turns on the -fstack-protector GCC feature. This 1531 feature puts, at the beginning of functions, a canary value on 1532 the stack just before the return address, and validates 1533 the value just before actually returning. Stack based buffer 1534 overflows (that need to overwrite this return address) now also 1535 overwrite the canary, which gets detected and the attack is then 1536 neutralized via a kernel panic. 1537 1538 This feature requires gcc version 4.2 or above, or a distribution 1539 gcc with the feature backported. Older versions are automatically 1540 detected and for those versions, this configuration option is 1541 ignored. (and a warning is printed during bootup) 1542 1543source kernel/Kconfig.hz 1544 1545config KEXEC 1546 bool "kexec system call" 1547 ---help--- 1548 kexec is a system call that implements the ability to shutdown your 1549 current kernel, and to start another kernel. It is like a reboot 1550 but it is independent of the system firmware. And like a reboot 1551 you can start any kernel with it, not just Linux. 1552 1553 The name comes from the similarity to the exec system call. 1554 1555 It is an ongoing process to be certain the hardware in a machine 1556 is properly shutdown, so do not be surprised if this code does not 1557 initially work for you. It may help to enable device hotplugging 1558 support. As of this writing the exact hardware interface is 1559 strongly in flux, so no good recommendation can be made. 1560 1561config CRASH_DUMP 1562 bool "kernel crash dumps" 1563 depends on X86_64 || (X86_32 && HIGHMEM) 1564 ---help--- 1565 Generate crash dump after being started by kexec. 1566 This should be normally only set in special crash dump kernels 1567 which are loaded in the main kernel with kexec-tools into 1568 a specially reserved region and then later executed after 1569 a crash by kdump/kexec. The crash dump kernel must be compiled 1570 to a memory address not used by the main kernel or BIOS using 1571 PHYSICAL_START, or it must be built as a relocatable image 1572 (CONFIG_RELOCATABLE=y). 1573 For more details see Documentation/kdump/kdump.txt 1574 1575config KEXEC_JUMP 1576 bool "kexec jump (EXPERIMENTAL)" 1577 depends on EXPERIMENTAL 1578 depends on KEXEC && HIBERNATION 1579 ---help--- 1580 Jump between original kernel and kexeced kernel and invoke 1581 code in physical address mode via KEXEC 1582 1583config PHYSICAL_START 1584 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1585 default "0x1000000" 1586 ---help--- 1587 This gives the physical address where the kernel is loaded. 1588 1589 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1590 bzImage will decompress itself to above physical address and 1591 run from there. Otherwise, bzImage will run from the address where 1592 it has been loaded by the boot loader and will ignore above physical 1593 address. 1594 1595 In normal kdump cases one does not have to set/change this option 1596 as now bzImage can be compiled as a completely relocatable image 1597 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1598 address. This option is mainly useful for the folks who don't want 1599 to use a bzImage for capturing the crash dump and want to use a 1600 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1601 to be specifically compiled to run from a specific memory area 1602 (normally a reserved region) and this option comes handy. 1603 1604 So if you are using bzImage for capturing the crash dump, 1605 leave the value here unchanged to 0x1000000 and set 1606 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1607 for capturing the crash dump change this value to start of 1608 the reserved region. In other words, it can be set based on 1609 the "X" value as specified in the "crashkernel=YM@XM" 1610 command line boot parameter passed to the panic-ed 1611 kernel. Please take a look at Documentation/kdump/kdump.txt 1612 for more details about crash dumps. 1613 1614 Usage of bzImage for capturing the crash dump is recommended as 1615 one does not have to build two kernels. Same kernel can be used 1616 as production kernel and capture kernel. Above option should have 1617 gone away after relocatable bzImage support is introduced. But it 1618 is present because there are users out there who continue to use 1619 vmlinux for dump capture. This option should go away down the 1620 line. 1621 1622 Don't change this unless you know what you are doing. 1623 1624config RELOCATABLE 1625 bool "Build a relocatable kernel" 1626 default y 1627 ---help--- 1628 This builds a kernel image that retains relocation information 1629 so it can be loaded someplace besides the default 1MB. 1630 The relocations tend to make the kernel binary about 10% larger, 1631 but are discarded at runtime. 1632 1633 One use is for the kexec on panic case where the recovery kernel 1634 must live at a different physical address than the primary 1635 kernel. 1636 1637 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1638 it has been loaded at and the compile time physical address 1639 (CONFIG_PHYSICAL_START) is ignored. 1640 1641# Relocation on x86-32 needs some additional build support 1642config X86_NEED_RELOCS 1643 def_bool y 1644 depends on X86_32 && RELOCATABLE 1645 1646config PHYSICAL_ALIGN 1647 hex "Alignment value to which kernel should be aligned" if X86_32 1648 default "0x1000000" 1649 range 0x2000 0x1000000 1650 ---help--- 1651 This value puts the alignment restrictions on physical address 1652 where kernel is loaded and run from. Kernel is compiled for an 1653 address which meets above alignment restriction. 1654 1655 If bootloader loads the kernel at a non-aligned address and 1656 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1657 address aligned to above value and run from there. 1658 1659 If bootloader loads the kernel at a non-aligned address and 1660 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1661 load address and decompress itself to the address it has been 1662 compiled for and run from there. The address for which kernel is 1663 compiled already meets above alignment restrictions. Hence the 1664 end result is that kernel runs from a physical address meeting 1665 above alignment restrictions. 1666 1667 Don't change this unless you know what you are doing. 1668 1669config HOTPLUG_CPU 1670 bool "Support for hot-pluggable CPUs" 1671 depends on SMP && HOTPLUG 1672 ---help--- 1673 Say Y here to allow turning CPUs off and on. CPUs can be 1674 controlled through /sys/devices/system/cpu. 1675 ( Note: power management support will enable this option 1676 automatically on SMP systems. ) 1677 Say N if you want to disable CPU hotplug. 1678 1679config COMPAT_VDSO 1680 def_bool y 1681 prompt "Compat VDSO support" 1682 depends on X86_32 || IA32_EMULATION 1683 ---help--- 1684 Map the 32-bit VDSO to the predictable old-style address too. 1685 1686 Say N here if you are running a sufficiently recent glibc 1687 version (2.3.3 or later), to remove the high-mapped 1688 VDSO mapping and to exclusively use the randomized VDSO. 1689 1690 If unsure, say Y. 1691 1692config CMDLINE_BOOL 1693 bool "Built-in kernel command line" 1694 ---help--- 1695 Allow for specifying boot arguments to the kernel at 1696 build time. On some systems (e.g. embedded ones), it is 1697 necessary or convenient to provide some or all of the 1698 kernel boot arguments with the kernel itself (that is, 1699 to not rely on the boot loader to provide them.) 1700 1701 To compile command line arguments into the kernel, 1702 set this option to 'Y', then fill in the 1703 the boot arguments in CONFIG_CMDLINE. 1704 1705 Systems with fully functional boot loaders (i.e. non-embedded) 1706 should leave this option set to 'N'. 1707 1708config CMDLINE 1709 string "Built-in kernel command string" 1710 depends on CMDLINE_BOOL 1711 default "" 1712 ---help--- 1713 Enter arguments here that should be compiled into the kernel 1714 image and used at boot time. If the boot loader provides a 1715 command line at boot time, it is appended to this string to 1716 form the full kernel command line, when the system boots. 1717 1718 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1719 change this behavior. 1720 1721 In most cases, the command line (whether built-in or provided 1722 by the boot loader) should specify the device for the root 1723 file system. 1724 1725config CMDLINE_OVERRIDE 1726 bool "Built-in command line overrides boot loader arguments" 1727 depends on CMDLINE_BOOL 1728 ---help--- 1729 Set this option to 'Y' to have the kernel ignore the boot loader 1730 command line, and use ONLY the built-in command line. 1731 1732 This is used to work around broken boot loaders. This should 1733 be set to 'N' under normal conditions. 1734 1735endmenu 1736 1737config ARCH_ENABLE_MEMORY_HOTPLUG 1738 def_bool y 1739 depends on X86_64 || (X86_32 && HIGHMEM) 1740 1741config ARCH_ENABLE_MEMORY_HOTREMOVE 1742 def_bool y 1743 depends on MEMORY_HOTPLUG 1744 1745config USE_PERCPU_NUMA_NODE_ID 1746 def_bool y 1747 depends on NUMA 1748 1749menu "Power management and ACPI options" 1750 1751config ARCH_HIBERNATION_HEADER 1752 def_bool y 1753 depends on X86_64 && HIBERNATION 1754 1755source "kernel/power/Kconfig" 1756 1757source "drivers/acpi/Kconfig" 1758 1759source "drivers/sfi/Kconfig" 1760 1761config X86_APM_BOOT 1762 def_bool y 1763 depends on APM 1764 1765menuconfig APM 1766 tristate "APM (Advanced Power Management) BIOS support" 1767 depends on X86_32 && PM_SLEEP 1768 ---help--- 1769 APM is a BIOS specification for saving power using several different 1770 techniques. This is mostly useful for battery powered laptops with 1771 APM compliant BIOSes. If you say Y here, the system time will be 1772 reset after a RESUME operation, the /proc/apm device will provide 1773 battery status information, and user-space programs will receive 1774 notification of APM "events" (e.g. battery status change). 1775 1776 If you select "Y" here, you can disable actual use of the APM 1777 BIOS by passing the "apm=off" option to the kernel at boot time. 1778 1779 Note that the APM support is almost completely disabled for 1780 machines with more than one CPU. 1781 1782 In order to use APM, you will need supporting software. For location 1783 and more information, read <file:Documentation/power/apm-acpi.txt> 1784 and the Battery Powered Linux mini-HOWTO, available from 1785 <http://www.tldp.org/docs.html#howto>. 1786 1787 This driver does not spin down disk drives (see the hdparm(8) 1788 manpage ("man 8 hdparm") for that), and it doesn't turn off 1789 VESA-compliant "green" monitors. 1790 1791 This driver does not support the TI 4000M TravelMate and the ACER 1792 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1793 desktop machines also don't have compliant BIOSes, and this driver 1794 may cause those machines to panic during the boot phase. 1795 1796 Generally, if you don't have a battery in your machine, there isn't 1797 much point in using this driver and you should say N. If you get 1798 random kernel OOPSes or reboots that don't seem to be related to 1799 anything, try disabling/enabling this option (or disabling/enabling 1800 APM in your BIOS). 1801 1802 Some other things you should try when experiencing seemingly random, 1803 "weird" problems: 1804 1805 1) make sure that you have enough swap space and that it is 1806 enabled. 1807 2) pass the "no-hlt" option to the kernel 1808 3) switch on floating point emulation in the kernel and pass 1809 the "no387" option to the kernel 1810 4) pass the "floppy=nodma" option to the kernel 1811 5) pass the "mem=4M" option to the kernel (thereby disabling 1812 all but the first 4 MB of RAM) 1813 6) make sure that the CPU is not over clocked. 1814 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1815 8) disable the cache from your BIOS settings 1816 9) install a fan for the video card or exchange video RAM 1817 10) install a better fan for the CPU 1818 11) exchange RAM chips 1819 12) exchange the motherboard. 1820 1821 To compile this driver as a module, choose M here: the 1822 module will be called apm. 1823 1824if APM 1825 1826config APM_IGNORE_USER_SUSPEND 1827 bool "Ignore USER SUSPEND" 1828 ---help--- 1829 This option will ignore USER SUSPEND requests. On machines with a 1830 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1831 series notebooks, it is necessary to say Y because of a BIOS bug. 1832 1833config APM_DO_ENABLE 1834 bool "Enable PM at boot time" 1835 ---help--- 1836 Enable APM features at boot time. From page 36 of the APM BIOS 1837 specification: "When disabled, the APM BIOS does not automatically 1838 power manage devices, enter the Standby State, enter the Suspend 1839 State, or take power saving steps in response to CPU Idle calls." 1840 This driver will make CPU Idle calls when Linux is idle (unless this 1841 feature is turned off -- see "Do CPU IDLE calls", below). This 1842 should always save battery power, but more complicated APM features 1843 will be dependent on your BIOS implementation. You may need to turn 1844 this option off if your computer hangs at boot time when using APM 1845 support, or if it beeps continuously instead of suspending. Turn 1846 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1847 T400CDT. This is off by default since most machines do fine without 1848 this feature. 1849 1850config APM_CPU_IDLE 1851 bool "Make CPU Idle calls when idle" 1852 ---help--- 1853 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1854 On some machines, this can activate improved power savings, such as 1855 a slowed CPU clock rate, when the machine is idle. These idle calls 1856 are made after the idle loop has run for some length of time (e.g., 1857 333 mS). On some machines, this will cause a hang at boot time or 1858 whenever the CPU becomes idle. (On machines with more than one CPU, 1859 this option does nothing.) 1860 1861config APM_DISPLAY_BLANK 1862 bool "Enable console blanking using APM" 1863 ---help--- 1864 Enable console blanking using the APM. Some laptops can use this to 1865 turn off the LCD backlight when the screen blanker of the Linux 1866 virtual console blanks the screen. Note that this is only used by 1867 the virtual console screen blanker, and won't turn off the backlight 1868 when using the X Window system. This also doesn't have anything to 1869 do with your VESA-compliant power-saving monitor. Further, this 1870 option doesn't work for all laptops -- it might not turn off your 1871 backlight at all, or it might print a lot of errors to the console, 1872 especially if you are using gpm. 1873 1874config APM_ALLOW_INTS 1875 bool "Allow interrupts during APM BIOS calls" 1876 ---help--- 1877 Normally we disable external interrupts while we are making calls to 1878 the APM BIOS as a measure to lessen the effects of a badly behaving 1879 BIOS implementation. The BIOS should reenable interrupts if it 1880 needs to. Unfortunately, some BIOSes do not -- especially those in 1881 many of the newer IBM Thinkpads. If you experience hangs when you 1882 suspend, try setting this to Y. Otherwise, say N. 1883 1884endif # APM 1885 1886source "drivers/cpufreq/Kconfig" 1887 1888source "drivers/cpuidle/Kconfig" 1889 1890source "drivers/idle/Kconfig" 1891 1892endmenu 1893 1894 1895menu "Bus options (PCI etc.)" 1896 1897config PCI 1898 bool "PCI support" 1899 default y 1900 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1901 ---help--- 1902 Find out whether you have a PCI motherboard. PCI is the name of a 1903 bus system, i.e. the way the CPU talks to the other stuff inside 1904 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1905 VESA. If you have PCI, say Y, otherwise N. 1906 1907choice 1908 prompt "PCI access mode" 1909 depends on X86_32 && PCI 1910 default PCI_GOANY 1911 ---help--- 1912 On PCI systems, the BIOS can be used to detect the PCI devices and 1913 determine their configuration. However, some old PCI motherboards 1914 have BIOS bugs and may crash if this is done. Also, some embedded 1915 PCI-based systems don't have any BIOS at all. Linux can also try to 1916 detect the PCI hardware directly without using the BIOS. 1917 1918 With this option, you can specify how Linux should detect the 1919 PCI devices. If you choose "BIOS", the BIOS will be used, 1920 if you choose "Direct", the BIOS won't be used, and if you 1921 choose "MMConfig", then PCI Express MMCONFIG will be used. 1922 If you choose "Any", the kernel will try MMCONFIG, then the 1923 direct access method and falls back to the BIOS if that doesn't 1924 work. If unsure, go with the default, which is "Any". 1925 1926config PCI_GOBIOS 1927 bool "BIOS" 1928 1929config PCI_GOMMCONFIG 1930 bool "MMConfig" 1931 1932config PCI_GODIRECT 1933 bool "Direct" 1934 1935config PCI_GOOLPC 1936 bool "OLPC XO-1" 1937 depends on OLPC 1938 1939config PCI_GOANY 1940 bool "Any" 1941 1942endchoice 1943 1944config PCI_BIOS 1945 def_bool y 1946 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 1947 1948# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 1949config PCI_DIRECT 1950 def_bool y 1951 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 1952 1953config PCI_MMCONFIG 1954 def_bool y 1955 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 1956 1957config PCI_OLPC 1958 def_bool y 1959 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 1960 1961config PCI_XEN 1962 def_bool y 1963 depends on PCI && XEN 1964 select SWIOTLB_XEN 1965 1966config PCI_DOMAINS 1967 def_bool y 1968 depends on PCI 1969 1970config PCI_MMCONFIG 1971 bool "Support mmconfig PCI config space access" 1972 depends on X86_64 && PCI && ACPI 1973 1974config PCI_CNB20LE_QUIRK 1975 bool "Read CNB20LE Host Bridge Windows" if EXPERT 1976 default n 1977 depends on PCI && EXPERIMENTAL 1978 help 1979 Read the PCI windows out of the CNB20LE host bridge. This allows 1980 PCI hotplug to work on systems with the CNB20LE chipset which do 1981 not have ACPI. 1982 1983 There's no public spec for this chipset, and this functionality 1984 is known to be incomplete. 1985 1986 You should say N unless you know you need this. 1987 1988source "drivers/pci/pcie/Kconfig" 1989 1990source "drivers/pci/Kconfig" 1991 1992# x86_64 have no ISA slots, but can have ISA-style DMA. 1993config ISA_DMA_API 1994 bool "ISA-style DMA support" if (X86_64 && EXPERT) 1995 default y 1996 help 1997 Enables ISA-style DMA support for devices requiring such controllers. 1998 If unsure, say Y. 1999 2000if X86_32 2001 2002config ISA 2003 bool "ISA support" 2004 ---help--- 2005 Find out whether you have ISA slots on your motherboard. ISA is the 2006 name of a bus system, i.e. the way the CPU talks to the other stuff 2007 inside your box. Other bus systems are PCI, EISA, MicroChannel 2008 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2009 newer boards don't support it. If you have ISA, say Y, otherwise N. 2010 2011config EISA 2012 bool "EISA support" 2013 depends on ISA 2014 ---help--- 2015 The Extended Industry Standard Architecture (EISA) bus was 2016 developed as an open alternative to the IBM MicroChannel bus. 2017 2018 The EISA bus provided some of the features of the IBM MicroChannel 2019 bus while maintaining backward compatibility with cards made for 2020 the older ISA bus. The EISA bus saw limited use between 1988 and 2021 1995 when it was made obsolete by the PCI bus. 2022 2023 Say Y here if you are building a kernel for an EISA-based machine. 2024 2025 Otherwise, say N. 2026 2027source "drivers/eisa/Kconfig" 2028 2029config SCx200 2030 tristate "NatSemi SCx200 support" 2031 ---help--- 2032 This provides basic support for National Semiconductor's 2033 (now AMD's) Geode processors. The driver probes for the 2034 PCI-IDs of several on-chip devices, so its a good dependency 2035 for other scx200_* drivers. 2036 2037 If compiled as a module, the driver is named scx200. 2038 2039config SCx200HR_TIMER 2040 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2041 depends on SCx200 2042 default y 2043 ---help--- 2044 This driver provides a clocksource built upon the on-chip 2045 27MHz high-resolution timer. Its also a workaround for 2046 NSC Geode SC-1100's buggy TSC, which loses time when the 2047 processor goes idle (as is done by the scheduler). The 2048 other workaround is idle=poll boot option. 2049 2050config OLPC 2051 bool "One Laptop Per Child support" 2052 depends on !X86_PAE 2053 select GPIOLIB 2054 select OF 2055 select OF_PROMTREE 2056 select IRQ_DOMAIN 2057 ---help--- 2058 Add support for detecting the unique features of the OLPC 2059 XO hardware. 2060 2061config OLPC_XO1_PM 2062 bool "OLPC XO-1 Power Management" 2063 depends on OLPC && MFD_CS5535 && PM_SLEEP 2064 select MFD_CORE 2065 ---help--- 2066 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2067 2068config OLPC_XO1_RTC 2069 bool "OLPC XO-1 Real Time Clock" 2070 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2071 ---help--- 2072 Add support for the XO-1 real time clock, which can be used as a 2073 programmable wakeup source. 2074 2075config OLPC_XO1_SCI 2076 bool "OLPC XO-1 SCI extras" 2077 depends on OLPC && OLPC_XO1_PM 2078 select POWER_SUPPLY 2079 select GPIO_CS5535 2080 select MFD_CORE 2081 ---help--- 2082 Add support for SCI-based features of the OLPC XO-1 laptop: 2083 - EC-driven system wakeups 2084 - Power button 2085 - Ebook switch 2086 - Lid switch 2087 - AC adapter status updates 2088 - Battery status updates 2089 2090config OLPC_XO15_SCI 2091 bool "OLPC XO-1.5 SCI extras" 2092 depends on OLPC && ACPI 2093 select POWER_SUPPLY 2094 ---help--- 2095 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2096 - EC-driven system wakeups 2097 - AC adapter status updates 2098 - Battery status updates 2099 2100config ALIX 2101 bool "PCEngines ALIX System Support (LED setup)" 2102 select GPIOLIB 2103 ---help--- 2104 This option enables system support for the PCEngines ALIX. 2105 At present this just sets up LEDs for GPIO control on 2106 ALIX2/3/6 boards. However, other system specific setup should 2107 get added here. 2108 2109 Note: You must still enable the drivers for GPIO and LED support 2110 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2111 2112 Note: You have to set alix.force=1 for boards with Award BIOS. 2113 2114config NET5501 2115 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2116 select GPIOLIB 2117 ---help--- 2118 This option enables system support for the Soekris Engineering net5501. 2119 2120config GEOS 2121 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2122 select GPIOLIB 2123 depends on DMI 2124 ---help--- 2125 This option enables system support for the Traverse Technologies GEOS. 2126 2127endif # X86_32 2128 2129config AMD_NB 2130 def_bool y 2131 depends on CPU_SUP_AMD && PCI 2132 2133source "drivers/pcmcia/Kconfig" 2134 2135source "drivers/pci/hotplug/Kconfig" 2136 2137config RAPIDIO 2138 bool "RapidIO support" 2139 depends on PCI 2140 default n 2141 help 2142 If you say Y here, the kernel will include drivers and 2143 infrastructure code to support RapidIO interconnect devices. 2144 2145source "drivers/rapidio/Kconfig" 2146 2147endmenu 2148 2149 2150menu "Executable file formats / Emulations" 2151 2152source "fs/Kconfig.binfmt" 2153 2154config IA32_EMULATION 2155 bool "IA32 Emulation" 2156 depends on X86_64 2157 select COMPAT_BINFMT_ELF 2158 ---help--- 2159 Include code to run legacy 32-bit programs under a 2160 64-bit kernel. You should likely turn this on, unless you're 2161 100% sure that you don't have any 32-bit programs left. 2162 2163config IA32_AOUT 2164 tristate "IA32 a.out support" 2165 depends on IA32_EMULATION 2166 ---help--- 2167 Support old a.out binaries in the 32bit emulation. 2168 2169config X86_X32 2170 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)" 2171 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL 2172 ---help--- 2173 Include code to run binaries for the x32 native 32-bit ABI 2174 for 64-bit processors. An x32 process gets access to the 2175 full 64-bit register file and wide data path while leaving 2176 pointers at 32 bits for smaller memory footprint. 2177 2178 You will need a recent binutils (2.22 or later) with 2179 elf32_x86_64 support enabled to compile a kernel with this 2180 option set. 2181 2182config COMPAT 2183 def_bool y 2184 depends on IA32_EMULATION || X86_X32 2185 select ARCH_WANT_OLD_COMPAT_IPC 2186 2187config COMPAT_FOR_U64_ALIGNMENT 2188 def_bool COMPAT 2189 depends on X86_64 2190 2191config SYSVIPC_COMPAT 2192 def_bool y 2193 depends on COMPAT && SYSVIPC 2194 2195config KEYS_COMPAT 2196 bool 2197 depends on COMPAT && KEYS 2198 default y 2199 2200endmenu 2201 2202 2203config HAVE_ATOMIC_IOMAP 2204 def_bool y 2205 depends on X86_32 2206 2207config HAVE_TEXT_POKE_SMP 2208 bool 2209 select STOP_MACHINE if SMP 2210 2211config X86_DEV_DMA_OPS 2212 bool 2213 depends on X86_64 || STA2X11 2214 2215config X86_DMA_REMAP 2216 bool 2217 depends on STA2X11 2218 2219source "net/Kconfig" 2220 2221source "drivers/Kconfig" 2222 2223source "drivers/firmware/Kconfig" 2224 2225source "fs/Kconfig" 2226 2227source "arch/x86/Kconfig.debug" 2228 2229source "security/Kconfig" 2230 2231source "crypto/Kconfig" 2232 2233source "arch/x86/kvm/Kconfig" 2234 2235source "lib/Kconfig" 2236