1# x86 configuration 2mainmenu "Linux Kernel Configuration for x86" 3 4# Select 32 or 64 bit 5config 64BIT 6 bool "64-bit kernel" if ARCH = "x86" 7 default ARCH = "x86_64" 8 help 9 Say yes to build a 64-bit kernel - formerly known as x86_64 10 Say no to build a 32-bit kernel - formerly known as i386 11 12config X86_32 13 def_bool !64BIT 14 15config X86_64 16 def_bool 64BIT 17 18### Arch settings 19config X86 20 def_bool y 21 select HAVE_AOUT if X86_32 22 select HAVE_UNSTABLE_SCHED_CLOCK 23 select HAVE_IDE 24 select HAVE_OPROFILE 25 select HAVE_IOREMAP_PROT 26 select HAVE_KPROBES 27 select ARCH_WANT_OPTIONAL_GPIOLIB 28 select HAVE_KRETPROBES 29 select HAVE_FTRACE_MCOUNT_RECORD 30 select HAVE_DYNAMIC_FTRACE 31 select HAVE_FUNCTION_TRACER 32 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64) 33 select HAVE_ARCH_KGDB if !X86_VOYAGER 34 select HAVE_ARCH_TRACEHOOK 35 select HAVE_GENERIC_DMA_COHERENT if X86_32 36 select HAVE_EFFICIENT_UNALIGNED_ACCESS 37 38config ARCH_DEFCONFIG 39 string 40 default "arch/x86/configs/i386_defconfig" if X86_32 41 default "arch/x86/configs/x86_64_defconfig" if X86_64 42 43config GENERIC_TIME 44 def_bool y 45 46config GENERIC_CMOS_UPDATE 47 def_bool y 48 49config CLOCKSOURCE_WATCHDOG 50 def_bool y 51 52config GENERIC_CLOCKEVENTS 53 def_bool y 54 55config GENERIC_CLOCKEVENTS_BROADCAST 56 def_bool y 57 depends on X86_64 || (X86_32 && X86_LOCAL_APIC) 58 59config LOCKDEP_SUPPORT 60 def_bool y 61 62config STACKTRACE_SUPPORT 63 def_bool y 64 65config HAVE_LATENCYTOP_SUPPORT 66 def_bool y 67 68config FAST_CMPXCHG_LOCAL 69 bool 70 default y 71 72config MMU 73 def_bool y 74 75config ZONE_DMA 76 def_bool y 77 78config SBUS 79 bool 80 81config GENERIC_ISA_DMA 82 def_bool y 83 84config GENERIC_IOMAP 85 def_bool y 86 87config GENERIC_BUG 88 def_bool y 89 depends on BUG 90 91config GENERIC_HWEIGHT 92 def_bool y 93 94config GENERIC_GPIO 95 bool 96 97config ARCH_MAY_HAVE_PC_FDC 98 def_bool y 99 100config RWSEM_GENERIC_SPINLOCK 101 def_bool !X86_XADD 102 103config RWSEM_XCHGADD_ALGORITHM 104 def_bool X86_XADD 105 106config ARCH_HAS_CPU_IDLE_WAIT 107 def_bool y 108 109config GENERIC_CALIBRATE_DELAY 110 def_bool y 111 112config GENERIC_TIME_VSYSCALL 113 bool 114 default X86_64 115 116config ARCH_HAS_CPU_RELAX 117 def_bool y 118 119config ARCH_HAS_DEFAULT_IDLE 120 def_bool y 121 122config ARCH_HAS_CACHE_LINE_SIZE 123 def_bool y 124 125config HAVE_SETUP_PER_CPU_AREA 126 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER) 127 128config HAVE_CPUMASK_OF_CPU_MAP 129 def_bool X86_64_SMP 130 131config ARCH_HIBERNATION_POSSIBLE 132 def_bool y 133 depends on !SMP || !X86_VOYAGER 134 135config ARCH_SUSPEND_POSSIBLE 136 def_bool y 137 depends on !X86_VOYAGER 138 139config ZONE_DMA32 140 bool 141 default X86_64 142 143config ARCH_POPULATES_NODE_MAP 144 def_bool y 145 146config AUDIT_ARCH 147 bool 148 default X86_64 149 150config ARCH_SUPPORTS_OPTIMIZED_INLINING 151 def_bool y 152 153# Use the generic interrupt handling code in kernel/irq/: 154config GENERIC_HARDIRQS 155 bool 156 default y 157 158config GENERIC_IRQ_PROBE 159 bool 160 default y 161 162config GENERIC_PENDING_IRQ 163 bool 164 depends on GENERIC_HARDIRQS && SMP 165 default y 166 167config X86_SMP 168 bool 169 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64) 170 default y 171 172config USE_GENERIC_SMP_HELPERS 173 def_bool y 174 depends on SMP 175 176config X86_32_SMP 177 def_bool y 178 depends on X86_32 && SMP 179 180config X86_64_SMP 181 def_bool y 182 depends on X86_64 && SMP 183 184config X86_HT 185 bool 186 depends on SMP 187 depends on (X86_32 && !X86_VOYAGER) || X86_64 188 default y 189 190config X86_BIOS_REBOOT 191 bool 192 depends on !X86_VOYAGER 193 default y 194 195config X86_TRAMPOLINE 196 bool 197 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP) 198 default y 199 200config KTIME_SCALAR 201 def_bool X86_32 202source "init/Kconfig" 203source "kernel/Kconfig.freezer" 204 205menu "Processor type and features" 206 207source "kernel/time/Kconfig" 208 209config SMP 210 bool "Symmetric multi-processing support" 211 ---help--- 212 This enables support for systems with more than one CPU. If you have 213 a system with only one CPU, like most personal computers, say N. If 214 you have a system with more than one CPU, say Y. 215 216 If you say N here, the kernel will run on single and multiprocessor 217 machines, but will use only one CPU of a multiprocessor machine. If 218 you say Y here, the kernel will run on many, but not all, 219 singleprocessor machines. On a singleprocessor machine, the kernel 220 will run faster if you say N here. 221 222 Note that if you say Y here and choose architecture "586" or 223 "Pentium" under "Processor family", the kernel will not work on 486 224 architectures. Similarly, multiprocessor kernels for the "PPro" 225 architecture may not work on all Pentium based boards. 226 227 People using multiprocessor machines who say Y here should also say 228 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 229 Management" code will be disabled if you say Y here. 230 231 See also <file:Documentation/i386/IO-APIC.txt>, 232 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 233 <http://www.tldp.org/docs.html#howto>. 234 235 If you don't know what to do here, say N. 236 237config X86_HAS_BOOT_CPU_ID 238 def_bool y 239 depends on X86_VOYAGER 240 241config X86_FIND_SMP_CONFIG 242 def_bool y 243 depends on X86_MPPARSE || X86_VOYAGER 244 245if ACPI 246config X86_MPPARSE 247 def_bool y 248 bool "Enable MPS table" 249 depends on X86_LOCAL_APIC 250 help 251 For old smp systems that do not have proper acpi support. Newer systems 252 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 253endif 254 255if !ACPI 256config X86_MPPARSE 257 def_bool y 258 depends on X86_LOCAL_APIC 259endif 260 261choice 262 prompt "Subarchitecture Type" 263 default X86_PC 264 265config X86_PC 266 bool "PC-compatible" 267 help 268 Choose this option if your computer is a standard PC or compatible. 269 270config X86_ELAN 271 bool "AMD Elan" 272 depends on X86_32 273 help 274 Select this for an AMD Elan processor. 275 276 Do not use this option for K6/Athlon/Opteron processors! 277 278 If unsure, choose "PC-compatible" instead. 279 280config X86_VOYAGER 281 bool "Voyager (NCR)" 282 depends on X86_32 && (SMP || BROKEN) && !PCI 283 help 284 Voyager is an MCA-based 32-way capable SMP architecture proprietary 285 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based. 286 287 *** WARNING *** 288 289 If you do not specifically know you have a Voyager based machine, 290 say N here, otherwise the kernel you build will not be bootable. 291 292config X86_GENERICARCH 293 bool "Generic architecture" 294 depends on X86_32 295 help 296 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default 297 subarchitectures. It is intended for a generic binary kernel. 298 if you select them all, kernel will probe it one by one. and will 299 fallback to default. 300 301if X86_GENERICARCH 302 303config X86_NUMAQ 304 bool "NUMAQ (IBM/Sequent)" 305 depends on SMP && X86_32 && PCI && X86_MPPARSE 306 select NUMA 307 help 308 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 309 NUMA multiquad box. This changes the way that processors are 310 bootstrapped, and uses Clustered Logical APIC addressing mode instead 311 of Flat Logical. You will need a new lynxer.elf file to flash your 312 firmware with - send email to <Martin.Bligh@us.ibm.com>. 313 314config X86_SUMMIT 315 bool "Summit/EXA (IBM x440)" 316 depends on X86_32 && SMP 317 help 318 This option is needed for IBM systems that use the Summit/EXA chipset. 319 In particular, it is needed for the x440. 320 321config X86_ES7000 322 bool "Support for Unisys ES7000 IA32 series" 323 depends on X86_32 && SMP 324 help 325 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 326 supposed to run on an IA32-based Unisys ES7000 system. 327 328config X86_BIGSMP 329 bool "Support for big SMP systems with more than 8 CPUs" 330 depends on X86_32 && SMP 331 help 332 This option is needed for the systems that have more than 8 CPUs 333 and if the system is not of any sub-arch type above. 334 335endif 336 337config X86_VSMP 338 bool "Support for ScaleMP vSMP" 339 select PARAVIRT 340 depends on X86_64 && PCI 341 help 342 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 343 supposed to run on these EM64T-based machines. Only choose this option 344 if you have one of these machines. 345 346endchoice 347 348config X86_VISWS 349 bool "SGI 320/540 (Visual Workstation)" 350 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT 351 help 352 The SGI Visual Workstation series is an IA32-based workstation 353 based on SGI systems chips with some legacy PC hardware attached. 354 355 Say Y here to create a kernel to run on the SGI 320 or 540. 356 357 A kernel compiled for the Visual Workstation will run on general 358 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 359 360config X86_RDC321X 361 bool "RDC R-321x SoC" 362 depends on X86_32 363 select M486 364 select X86_REBOOTFIXUPS 365 help 366 This option is needed for RDC R-321x system-on-chip, also known 367 as R-8610-(G). 368 If you don't have one of these chips, you should say N here. 369 370config SCHED_NO_NO_OMIT_FRAME_POINTER 371 def_bool y 372 prompt "Single-depth WCHAN output" 373 depends on X86_32 374 help 375 Calculate simpler /proc/<PID>/wchan values. If this option 376 is disabled then wchan values will recurse back to the 377 caller function. This provides more accurate wchan values, 378 at the expense of slightly more scheduling overhead. 379 380 If in doubt, say "Y". 381 382menuconfig PARAVIRT_GUEST 383 bool "Paravirtualized guest support" 384 help 385 Say Y here to get to see options related to running Linux under 386 various hypervisors. This option alone does not add any kernel code. 387 388 If you say N, all options in this submenu will be skipped and disabled. 389 390if PARAVIRT_GUEST 391 392source "arch/x86/xen/Kconfig" 393 394config VMI 395 bool "VMI Guest support" 396 select PARAVIRT 397 depends on X86_32 398 depends on !X86_VOYAGER 399 help 400 VMI provides a paravirtualized interface to the VMware ESX server 401 (it could be used by other hypervisors in theory too, but is not 402 at the moment), by linking the kernel to a GPL-ed ROM module 403 provided by the hypervisor. 404 405config KVM_CLOCK 406 bool "KVM paravirtualized clock" 407 select PARAVIRT 408 select PARAVIRT_CLOCK 409 depends on !X86_VOYAGER 410 help 411 Turning on this option will allow you to run a paravirtualized clock 412 when running over the KVM hypervisor. Instead of relying on a PIT 413 (or probably other) emulation by the underlying device model, the host 414 provides the guest with timing infrastructure such as time of day, and 415 system time 416 417config KVM_GUEST 418 bool "KVM Guest support" 419 select PARAVIRT 420 depends on !X86_VOYAGER 421 help 422 This option enables various optimizations for running under the KVM 423 hypervisor. 424 425source "arch/x86/lguest/Kconfig" 426 427config PARAVIRT 428 bool "Enable paravirtualization code" 429 depends on !X86_VOYAGER 430 help 431 This changes the kernel so it can modify itself when it is run 432 under a hypervisor, potentially improving performance significantly 433 over full virtualization. However, when run without a hypervisor 434 the kernel is theoretically slower and slightly larger. 435 436config PARAVIRT_CLOCK 437 bool 438 default n 439 440endif 441 442config PARAVIRT_DEBUG 443 bool "paravirt-ops debugging" 444 depends on PARAVIRT && DEBUG_KERNEL 445 help 446 Enable to debug paravirt_ops internals. Specifically, BUG if 447 a paravirt_op is missing when it is called. 448 449config MEMTEST 450 bool "Memtest" 451 help 452 This option adds a kernel parameter 'memtest', which allows memtest 453 to be set. 454 memtest=0, mean disabled; -- default 455 memtest=1, mean do 1 test pattern; 456 ... 457 memtest=4, mean do 4 test patterns. 458 If you are unsure how to answer this question, answer N. 459 460config X86_SUMMIT_NUMA 461 def_bool y 462 depends on X86_32 && NUMA && X86_GENERICARCH 463 464config X86_CYCLONE_TIMER 465 def_bool y 466 depends on X86_GENERICARCH 467 468config ES7000_CLUSTERED_APIC 469 def_bool y 470 depends on SMP && X86_ES7000 && MPENTIUMIII 471 472source "arch/x86/Kconfig.cpu" 473 474config HPET_TIMER 475 def_bool X86_64 476 prompt "HPET Timer Support" if X86_32 477 help 478 Use the IA-PC HPET (High Precision Event Timer) to manage 479 time in preference to the PIT and RTC, if a HPET is 480 present. 481 HPET is the next generation timer replacing legacy 8254s. 482 The HPET provides a stable time base on SMP 483 systems, unlike the TSC, but it is more expensive to access, 484 as it is off-chip. You can find the HPET spec at 485 <http://www.intel.com/hardwaredesign/hpetspec.htm>. 486 487 You can safely choose Y here. However, HPET will only be 488 activated if the platform and the BIOS support this feature. 489 Otherwise the 8254 will be used for timing services. 490 491 Choose N to continue using the legacy 8254 timer. 492 493config HPET_EMULATE_RTC 494 def_bool y 495 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 496 497# Mark as embedded because too many people got it wrong. 498# The code disables itself when not needed. 499config DMI 500 default y 501 bool "Enable DMI scanning" if EMBEDDED 502 help 503 Enabled scanning of DMI to identify machine quirks. Say Y 504 here unless you have verified that your setup is not 505 affected by entries in the DMI blacklist. Required by PNP 506 BIOS code. 507 508config GART_IOMMU 509 bool "GART IOMMU support" if EMBEDDED 510 default y 511 select SWIOTLB 512 select AGP 513 depends on X86_64 && PCI 514 help 515 Support for full DMA access of devices with 32bit memory access only 516 on systems with more than 3GB. This is usually needed for USB, 517 sound, many IDE/SATA chipsets and some other devices. 518 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 519 based hardware IOMMU and a software bounce buffer based IOMMU used 520 on Intel systems and as fallback. 521 The code is only active when needed (enough memory and limited 522 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 523 too. 524 525config CALGARY_IOMMU 526 bool "IBM Calgary IOMMU support" 527 select SWIOTLB 528 depends on X86_64 && PCI && EXPERIMENTAL 529 help 530 Support for hardware IOMMUs in IBM's xSeries x366 and x460 531 systems. Needed to run systems with more than 3GB of memory 532 properly with 32-bit PCI devices that do not support DAC 533 (Double Address Cycle). Calgary also supports bus level 534 isolation, where all DMAs pass through the IOMMU. This 535 prevents them from going anywhere except their intended 536 destination. This catches hard-to-find kernel bugs and 537 mis-behaving drivers and devices that do not use the DMA-API 538 properly to set up their DMA buffers. The IOMMU can be 539 turned off at boot time with the iommu=off parameter. 540 Normally the kernel will make the right choice by itself. 541 If unsure, say Y. 542 543config CALGARY_IOMMU_ENABLED_BY_DEFAULT 544 def_bool y 545 prompt "Should Calgary be enabled by default?" 546 depends on CALGARY_IOMMU 547 help 548 Should Calgary be enabled by default? if you choose 'y', Calgary 549 will be used (if it exists). If you choose 'n', Calgary will not be 550 used even if it exists. If you choose 'n' and would like to use 551 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 552 If unsure, say Y. 553 554config AMD_IOMMU 555 bool "AMD IOMMU support" 556 select SWIOTLB 557 select PCI_MSI 558 depends on X86_64 && PCI && ACPI 559 help 560 With this option you can enable support for AMD IOMMU hardware in 561 your system. An IOMMU is a hardware component which provides 562 remapping of DMA memory accesses from devices. With an AMD IOMMU you 563 can isolate the the DMA memory of different devices and protect the 564 system from misbehaving device drivers or hardware. 565 566 You can find out if your system has an AMD IOMMU if you look into 567 your BIOS for an option to enable it or if you have an IVRS ACPI 568 table. 569 570# need this always selected by IOMMU for the VIA workaround 571config SWIOTLB 572 bool 573 help 574 Support for software bounce buffers used on x86-64 systems 575 which don't have a hardware IOMMU (e.g. the current generation 576 of Intel's x86-64 CPUs). Using this PCI devices which can only 577 access 32-bits of memory can be used on systems with more than 578 3 GB of memory. If unsure, say Y. 579 580config IOMMU_HELPER 581 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU) 582 583config MAXSMP 584 bool "Configure Maximum number of SMP Processors and NUMA Nodes" 585 depends on X86_64 && SMP && BROKEN 586 default n 587 help 588 Configure maximum number of CPUS and NUMA Nodes for this architecture. 589 If unsure, say N. 590 591config NR_CPUS 592 int "Maximum number of CPUs (2-512)" if !MAXSMP 593 range 2 512 594 depends on SMP 595 default "4096" if MAXSMP 596 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000 597 default "8" 598 help 599 This allows you to specify the maximum number of CPUs which this 600 kernel will support. The maximum supported value is 512 and the 601 minimum value which makes sense is 2. 602 603 This is purely to save memory - each supported CPU adds 604 approximately eight kilobytes to the kernel image. 605 606config SCHED_SMT 607 bool "SMT (Hyperthreading) scheduler support" 608 depends on X86_HT 609 help 610 SMT scheduler support improves the CPU scheduler's decision making 611 when dealing with Intel Pentium 4 chips with HyperThreading at a 612 cost of slightly increased overhead in some places. If unsure say 613 N here. 614 615config SCHED_MC 616 def_bool y 617 prompt "Multi-core scheduler support" 618 depends on X86_HT 619 help 620 Multi-core scheduler support improves the CPU scheduler's decision 621 making when dealing with multi-core CPU chips at a cost of slightly 622 increased overhead in some places. If unsure say N here. 623 624source "kernel/Kconfig.preempt" 625 626config X86_UP_APIC 627 bool "Local APIC support on uniprocessors" 628 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH) 629 help 630 A local APIC (Advanced Programmable Interrupt Controller) is an 631 integrated interrupt controller in the CPU. If you have a single-CPU 632 system which has a processor with a local APIC, you can say Y here to 633 enable and use it. If you say Y here even though your machine doesn't 634 have a local APIC, then the kernel will still run with no slowdown at 635 all. The local APIC supports CPU-generated self-interrupts (timer, 636 performance counters), and the NMI watchdog which detects hard 637 lockups. 638 639config X86_UP_IOAPIC 640 bool "IO-APIC support on uniprocessors" 641 depends on X86_UP_APIC 642 help 643 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 644 SMP-capable replacement for PC-style interrupt controllers. Most 645 SMP systems and many recent uniprocessor systems have one. 646 647 If you have a single-CPU system with an IO-APIC, you can say Y here 648 to use it. If you say Y here even though your machine doesn't have 649 an IO-APIC, then the kernel will still run with no slowdown at all. 650 651config X86_LOCAL_APIC 652 def_bool y 653 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH)) 654 655config X86_IO_APIC 656 def_bool y 657 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH)) 658 659config X86_VISWS_APIC 660 def_bool y 661 depends on X86_32 && X86_VISWS 662 663config X86_MCE 664 bool "Machine Check Exception" 665 depends on !X86_VOYAGER 666 ---help--- 667 Machine Check Exception support allows the processor to notify the 668 kernel if it detects a problem (e.g. overheating, component failure). 669 The action the kernel takes depends on the severity of the problem, 670 ranging from a warning message on the console, to halting the machine. 671 Your processor must be a Pentium or newer to support this - check the 672 flags in /proc/cpuinfo for mce. Note that some older Pentium systems 673 have a design flaw which leads to false MCE events - hence MCE is 674 disabled on all P5 processors, unless explicitly enabled with "mce" 675 as a boot argument. Similarly, if MCE is built in and creates a 676 problem on some new non-standard machine, you can boot with "nomce" 677 to disable it. MCE support simply ignores non-MCE processors like 678 the 386 and 486, so nearly everyone can say Y here. 679 680config X86_MCE_INTEL 681 def_bool y 682 prompt "Intel MCE features" 683 depends on X86_64 && X86_MCE && X86_LOCAL_APIC 684 help 685 Additional support for intel specific MCE features such as 686 the thermal monitor. 687 688config X86_MCE_AMD 689 def_bool y 690 prompt "AMD MCE features" 691 depends on X86_64 && X86_MCE && X86_LOCAL_APIC 692 help 693 Additional support for AMD specific MCE features such as 694 the DRAM Error Threshold. 695 696config X86_MCE_NONFATAL 697 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" 698 depends on X86_32 && X86_MCE 699 help 700 Enabling this feature starts a timer that triggers every 5 seconds which 701 will look at the machine check registers to see if anything happened. 702 Non-fatal problems automatically get corrected (but still logged). 703 Disable this if you don't want to see these messages. 704 Seeing the messages this option prints out may be indicative of dying 705 or out-of-spec (ie, overclocked) hardware. 706 This option only does something on certain CPUs. 707 (AMD Athlon/Duron and Intel Pentium 4) 708 709config X86_MCE_P4THERMAL 710 bool "check for P4 thermal throttling interrupt." 711 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) 712 help 713 Enabling this feature will cause a message to be printed when the P4 714 enters thermal throttling. 715 716config VM86 717 bool "Enable VM86 support" if EMBEDDED 718 default y 719 depends on X86_32 720 help 721 This option is required by programs like DOSEMU to run 16-bit legacy 722 code on X86 processors. It also may be needed by software like 723 XFree86 to initialize some video cards via BIOS. Disabling this 724 option saves about 6k. 725 726config TOSHIBA 727 tristate "Toshiba Laptop support" 728 depends on X86_32 729 ---help--- 730 This adds a driver to safely access the System Management Mode of 731 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 732 not work on models with a Phoenix BIOS. The System Management Mode 733 is used to set the BIOS and power saving options on Toshiba portables. 734 735 For information on utilities to make use of this driver see the 736 Toshiba Linux utilities web site at: 737 <http://www.buzzard.org.uk/toshiba/>. 738 739 Say Y if you intend to run this kernel on a Toshiba portable. 740 Say N otherwise. 741 742config I8K 743 tristate "Dell laptop support" 744 ---help--- 745 This adds a driver to safely access the System Management Mode 746 of the CPU on the Dell Inspiron 8000. The System Management Mode 747 is used to read cpu temperature and cooling fan status and to 748 control the fans on the I8K portables. 749 750 This driver has been tested only on the Inspiron 8000 but it may 751 also work with other Dell laptops. You can force loading on other 752 models by passing the parameter `force=1' to the module. Use at 753 your own risk. 754 755 For information on utilities to make use of this driver see the 756 I8K Linux utilities web site at: 757 <http://people.debian.org/~dz/i8k/> 758 759 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 760 Say N otherwise. 761 762config X86_REBOOTFIXUPS 763 bool "Enable X86 board specific fixups for reboot" 764 depends on X86_32 765 ---help--- 766 This enables chipset and/or board specific fixups to be done 767 in order to get reboot to work correctly. This is only needed on 768 some combinations of hardware and BIOS. The symptom, for which 769 this config is intended, is when reboot ends with a stalled/hung 770 system. 771 772 Currently, the only fixup is for the Geode machines using 773 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 774 775 Say Y if you want to enable the fixup. Currently, it's safe to 776 enable this option even if you don't need it. 777 Say N otherwise. 778 779config MICROCODE 780 tristate "/dev/cpu/microcode - microcode support" 781 select FW_LOADER 782 ---help--- 783 If you say Y here, you will be able to update the microcode on 784 certain Intel and AMD processors. The Intel support is for the 785 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, 786 Pentium 4, Xeon etc. The AMD support is for family 0x10 and 787 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra. 788 You will obviously need the actual microcode binary data itself 789 which is not shipped with the Linux kernel. 790 791 This option selects the general module only, you need to select 792 at least one vendor specific module as well. 793 794 To compile this driver as a module, choose M here: the 795 module will be called microcode. 796 797config MICROCODE_INTEL 798 bool "Intel microcode patch loading support" 799 depends on MICROCODE 800 default MICROCODE 801 select FW_LOADER 802 --help--- 803 This options enables microcode patch loading support for Intel 804 processors. 805 806 For latest news and information on obtaining all the required 807 Intel ingredients for this driver, check: 808 <http://www.urbanmyth.org/microcode/>. 809 810config MICROCODE_AMD 811 bool "AMD microcode patch loading support" 812 depends on MICROCODE 813 select FW_LOADER 814 --help--- 815 If you select this option, microcode patch loading support for AMD 816 processors will be enabled. 817 818 config MICROCODE_OLD_INTERFACE 819 def_bool y 820 depends on MICROCODE 821 822config X86_MSR 823 tristate "/dev/cpu/*/msr - Model-specific register support" 824 help 825 This device gives privileged processes access to the x86 826 Model-Specific Registers (MSRs). It is a character device with 827 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 828 MSR accesses are directed to a specific CPU on multi-processor 829 systems. 830 831config X86_CPUID 832 tristate "/dev/cpu/*/cpuid - CPU information support" 833 help 834 This device gives processes access to the x86 CPUID instruction to 835 be executed on a specific processor. It is a character device 836 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 837 /dev/cpu/31/cpuid. 838 839choice 840 prompt "High Memory Support" 841 default HIGHMEM4G if !X86_NUMAQ 842 default HIGHMEM64G if X86_NUMAQ 843 depends on X86_32 844 845config NOHIGHMEM 846 bool "off" 847 depends on !X86_NUMAQ 848 ---help--- 849 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 850 However, the address space of 32-bit x86 processors is only 4 851 Gigabytes large. That means that, if you have a large amount of 852 physical memory, not all of it can be "permanently mapped" by the 853 kernel. The physical memory that's not permanently mapped is called 854 "high memory". 855 856 If you are compiling a kernel which will never run on a machine with 857 more than 1 Gigabyte total physical RAM, answer "off" here (default 858 choice and suitable for most users). This will result in a "3GB/1GB" 859 split: 3GB are mapped so that each process sees a 3GB virtual memory 860 space and the remaining part of the 4GB virtual memory space is used 861 by the kernel to permanently map as much physical memory as 862 possible. 863 864 If the machine has between 1 and 4 Gigabytes physical RAM, then 865 answer "4GB" here. 866 867 If more than 4 Gigabytes is used then answer "64GB" here. This 868 selection turns Intel PAE (Physical Address Extension) mode on. 869 PAE implements 3-level paging on IA32 processors. PAE is fully 870 supported by Linux, PAE mode is implemented on all recent Intel 871 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 872 then the kernel will not boot on CPUs that don't support PAE! 873 874 The actual amount of total physical memory will either be 875 auto detected or can be forced by using a kernel command line option 876 such as "mem=256M". (Try "man bootparam" or see the documentation of 877 your boot loader (lilo or loadlin) about how to pass options to the 878 kernel at boot time.) 879 880 If unsure, say "off". 881 882config HIGHMEM4G 883 bool "4GB" 884 depends on !X86_NUMAQ 885 help 886 Select this if you have a 32-bit processor and between 1 and 4 887 gigabytes of physical RAM. 888 889config HIGHMEM64G 890 bool "64GB" 891 depends on !M386 && !M486 892 select X86_PAE 893 help 894 Select this if you have a 32-bit processor and more than 4 895 gigabytes of physical RAM. 896 897endchoice 898 899choice 900 depends on EXPERIMENTAL 901 prompt "Memory split" if EMBEDDED 902 default VMSPLIT_3G 903 depends on X86_32 904 help 905 Select the desired split between kernel and user memory. 906 907 If the address range available to the kernel is less than the 908 physical memory installed, the remaining memory will be available 909 as "high memory". Accessing high memory is a little more costly 910 than low memory, as it needs to be mapped into the kernel first. 911 Note that increasing the kernel address space limits the range 912 available to user programs, making the address space there 913 tighter. Selecting anything other than the default 3G/1G split 914 will also likely make your kernel incompatible with binary-only 915 kernel modules. 916 917 If you are not absolutely sure what you are doing, leave this 918 option alone! 919 920 config VMSPLIT_3G 921 bool "3G/1G user/kernel split" 922 config VMSPLIT_3G_OPT 923 depends on !X86_PAE 924 bool "3G/1G user/kernel split (for full 1G low memory)" 925 config VMSPLIT_2G 926 bool "2G/2G user/kernel split" 927 config VMSPLIT_2G_OPT 928 depends on !X86_PAE 929 bool "2G/2G user/kernel split (for full 2G low memory)" 930 config VMSPLIT_1G 931 bool "1G/3G user/kernel split" 932endchoice 933 934config PAGE_OFFSET 935 hex 936 default 0xB0000000 if VMSPLIT_3G_OPT 937 default 0x80000000 if VMSPLIT_2G 938 default 0x78000000 if VMSPLIT_2G_OPT 939 default 0x40000000 if VMSPLIT_1G 940 default 0xC0000000 941 depends on X86_32 942 943config HIGHMEM 944 def_bool y 945 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 946 947config X86_PAE 948 bool "PAE (Physical Address Extension) Support" 949 depends on X86_32 && !HIGHMEM4G 950 help 951 PAE is required for NX support, and furthermore enables 952 larger swapspace support for non-overcommit purposes. It 953 has the cost of more pagetable lookup overhead, and also 954 consumes more pagetable space per process. 955 956config ARCH_PHYS_ADDR_T_64BIT 957 def_bool X86_64 || X86_PAE 958 959# Common NUMA Features 960config NUMA 961 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)" 962 depends on SMP 963 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL) 964 default n if X86_PC 965 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 966 help 967 Enable NUMA (Non Uniform Memory Access) support. 968 The kernel will try to allocate memory used by a CPU on the 969 local memory controller of the CPU and add some more 970 NUMA awareness to the kernel. 971 972 For 32-bit this is currently highly experimental and should be only 973 used for kernel development. It might also cause boot failures. 974 For 64-bit this is recommended on all multiprocessor Opteron systems. 975 If the system is EM64T, you should say N unless your system is 976 EM64T NUMA. 977 978comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 979 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 980 981config K8_NUMA 982 def_bool y 983 prompt "Old style AMD Opteron NUMA detection" 984 depends on X86_64 && NUMA && PCI 985 help 986 Enable K8 NUMA node topology detection. You should say Y here if 987 you have a multi processor AMD K8 system. This uses an old 988 method to read the NUMA configuration directly from the builtin 989 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA 990 instead, which also takes priority if both are compiled in. 991 992config X86_64_ACPI_NUMA 993 def_bool y 994 prompt "ACPI NUMA detection" 995 depends on X86_64 && NUMA && ACPI && PCI 996 select ACPI_NUMA 997 help 998 Enable ACPI SRAT based node topology detection. 999 1000# Some NUMA nodes have memory ranges that span
1001# other nodes. Even though a pfn is valid and 1002# between a node's start and end pfns, it may not 1003# reside on that node. See memmap_init_zone() 1004# for details. 1005config NODES_SPAN_OTHER_NODES 1006 def_bool y 1007 depends on X86_64_ACPI_NUMA 1008 1009config NUMA_EMU 1010 bool "NUMA emulation" 1011 depends on X86_64 && NUMA 1012 help 1013 Enable NUMA emulation. A flat machine will be split 1014 into virtual nodes when booted with "numa=fake=N", where N is the 1015 number of nodes. This is only useful for debugging. 1016 1017config NODES_SHIFT 1018 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1019 range 1 9 if X86_64 1020 default "9" if MAXSMP 1021 default "6" if X86_64 1022 default "4" if X86_NUMAQ 1023 default "3" 1024 depends on NEED_MULTIPLE_NODES 1025 help 1026 Specify the maximum number of NUMA Nodes available on the target 1027 system. Increases memory reserved to accomodate various tables. 1028 1029config HAVE_ARCH_BOOTMEM_NODE 1030 def_bool y 1031 depends on X86_32 && NUMA 1032 1033config ARCH_HAVE_MEMORY_PRESENT 1034 def_bool y 1035 depends on X86_32 && DISCONTIGMEM 1036 1037config NEED_NODE_MEMMAP_SIZE 1038 def_bool y 1039 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1040 1041config HAVE_ARCH_ALLOC_REMAP 1042 def_bool y 1043 depends on X86_32 && NUMA 1044 1045config ARCH_FLATMEM_ENABLE 1046 def_bool y 1047 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA 1048 1049config ARCH_DISCONTIGMEM_ENABLE 1050 def_bool y 1051 depends on NUMA && X86_32 1052 1053config ARCH_DISCONTIGMEM_DEFAULT 1054 def_bool y 1055 depends on NUMA && X86_32 1056 1057config ARCH_SPARSEMEM_DEFAULT 1058 def_bool y 1059 depends on X86_64 1060 1061config ARCH_SPARSEMEM_ENABLE 1062 def_bool y 1063 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH 1064 select SPARSEMEM_STATIC if X86_32 1065 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1066 1067config ARCH_SELECT_MEMORY_MODEL 1068 def_bool y 1069 depends on ARCH_SPARSEMEM_ENABLE 1070 1071config ARCH_MEMORY_PROBE 1072 def_bool X86_64 1073 depends on MEMORY_HOTPLUG 1074 1075source "mm/Kconfig" 1076 1077config HIGHPTE 1078 bool "Allocate 3rd-level pagetables from highmem" 1079 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G) 1080 help 1081 The VM uses one page table entry for each page of physical memory. 1082 For systems with a lot of RAM, this can be wasteful of precious 1083 low memory. Setting this option will put user-space page table 1084 entries in high memory. 1085 1086config X86_CHECK_BIOS_CORRUPTION 1087 bool "Check for low memory corruption" 1088 help 1089 Periodically check for memory corruption in low memory, which 1090 is suspected to be caused by BIOS. Even when enabled in the 1091 configuration, it is disabled at runtime. Enable it by 1092 setting "memory_corruption_check=1" on the kernel command 1093 line. By default it scans the low 64k of memory every 60 1094 seconds; see the memory_corruption_check_size and 1095 memory_corruption_check_period parameters in 1096 Documentation/kernel-parameters.txt to adjust this. 1097 1098 When enabled with the default parameters, this option has 1099 almost no overhead, as it reserves a relatively small amount 1100 of memory and scans it infrequently. It both detects corruption 1101 and prevents it from affecting the running system. 1102 1103 It is, however, intended as a diagnostic tool; if repeatable 1104 BIOS-originated corruption always affects the same memory, 1105 you can use memmap= to prevent the kernel from using that 1106 memory. 1107 1108config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1109 bool "Set the default setting of memory_corruption_check" 1110 depends on X86_CHECK_BIOS_CORRUPTION 1111 default y 1112 help 1113 Set whether the default state of memory_corruption_check is 1114 on or off. 1115 1116config X86_RESERVE_LOW_64K 1117 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen" 1118 default y 1119 help 1120 Reserve the first 64K of physical RAM on BIOSes that are known 1121 to potentially corrupt that memory range. A numbers of BIOSes are 1122 known to utilize this area during suspend/resume, so it must not 1123 be used by the kernel. 1124 1125 Set this to N if you are absolutely sure that you trust the BIOS 1126 to get all its memory reservations and usages right. 1127 1128 If you have doubts about the BIOS (e.g. suspend/resume does not 1129 work or there's kernel crashes after certain hardware hotplug 1130 events) and it's not AMI or Phoenix, then you might want to enable 1131 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical 1132 corruption patterns. 1133 1134 Say Y if unsure. 1135 1136config MATH_EMULATION 1137 bool 1138 prompt "Math emulation" if X86_32 1139 ---help--- 1140 Linux can emulate a math coprocessor (used for floating point 1141 operations) if you don't have one. 486DX and Pentium processors have 1142 a math coprocessor built in, 486SX and 386 do not, unless you added 1143 a 487DX or 387, respectively. (The messages during boot time can 1144 give you some hints here ["man dmesg"].) Everyone needs either a 1145 coprocessor or this emulation. 1146 1147 If you don't have a math coprocessor, you need to say Y here; if you 1148 say Y here even though you have a coprocessor, the coprocessor will 1149 be used nevertheless. (This behavior can be changed with the kernel 1150 command line option "no387", which comes handy if your coprocessor 1151 is broken. Try "man bootparam" or see the documentation of your boot 1152 loader (lilo or loadlin) about how to pass options to the kernel at 1153 boot time.) This means that it is a good idea to say Y here if you 1154 intend to use this kernel on different machines. 1155 1156 More information about the internals of the Linux math coprocessor 1157 emulation can be found in <file:arch/x86/math-emu/README>. 1158 1159 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1160 kernel, it won't hurt. 1161 1162config MTRR 1163 bool "MTRR (Memory Type Range Register) support" 1164 ---help--- 1165 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1166 the Memory Type Range Registers (MTRRs) may be used to control 1167 processor access to memory ranges. This is most useful if you have 1168 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1169 allows bus write transfers to be combined into a larger transfer 1170 before bursting over the PCI/AGP bus. This can increase performance 1171 of image write operations 2.5 times or more. Saying Y here creates a 1172 /proc/mtrr file which may be used to manipulate your processor's 1173 MTRRs. Typically the X server should use this. 1174 1175 This code has a reasonably generic interface so that similar 1176 control registers on other processors can be easily supported 1177 as well: 1178 1179 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1180 Registers (ARRs) which provide a similar functionality to MTRRs. For 1181 these, the ARRs are used to emulate the MTRRs. 1182 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1183 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1184 write-combining. All of these processors are supported by this code 1185 and it makes sense to say Y here if you have one of them. 1186 1187 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1188 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1189 can lead to all sorts of problems, so it's good to say Y here. 1190 1191 You can safely say Y even if your machine doesn't have MTRRs, you'll 1192 just add about 9 KB to your kernel. 1193 1194 See <file:Documentation/x86/mtrr.txt> for more information. 1195 1196config MTRR_SANITIZER 1197 def_bool y 1198 prompt "MTRR cleanup support" 1199 depends on MTRR 1200 help 1201 Convert MTRR layout from continuous to discrete, so X drivers can 1202 add writeback entries. 1203 1204 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1205 The largest mtrr entry size for a continous block can be set with 1206 mtrr_chunk_size. 1207 1208 If unsure, say Y. 1209 1210config MTRR_SANITIZER_ENABLE_DEFAULT 1211 int "MTRR cleanup enable value (0-1)" 1212 range 0 1 1213 default "0" 1214 depends on MTRR_SANITIZER 1215 help 1216 Enable mtrr cleanup default value 1217 1218config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1219 int "MTRR cleanup spare reg num (0-7)" 1220 range 0 7 1221 default "1" 1222 depends on MTRR_SANITIZER 1223 help 1224 mtrr cleanup spare entries default, it can be changed via 1225 mtrr_spare_reg_nr=N on the kernel command line. 1226 1227config X86_PAT 1228 bool 1229 prompt "x86 PAT support" 1230 depends on MTRR 1231 help 1232 Use PAT attributes to setup page level cache control. 1233 1234 PATs are the modern equivalents of MTRRs and are much more 1235 flexible than MTRRs. 1236 1237 Say N here if you see bootup problems (boot crash, boot hang, 1238 spontaneous reboots) or a non-working video driver. 1239 1240 If unsure, say Y. 1241 1242config EFI 1243 bool "EFI runtime service support" 1244 depends on ACPI 1245 ---help--- 1246 This enables the kernel to use EFI runtime services that are 1247 available (such as the EFI variable services). 1248 1249 This option is only useful on systems that have EFI firmware. 1250 In addition, you should use the latest ELILO loader available 1251 at <http://elilo.sourceforge.net> in order to take advantage 1252 of EFI runtime services. However, even with this option, the 1253 resultant kernel should continue to boot on existing non-EFI 1254 platforms. 1255 1256config SECCOMP 1257 def_bool y 1258 prompt "Enable seccomp to safely compute untrusted bytecode" 1259 help 1260 This kernel feature is useful for number crunching applications 1261 that may need to compute untrusted bytecode during their 1262 execution. By using pipes or other transports made available to 1263 the process as file descriptors supporting the read/write 1264 syscalls, it's possible to isolate those applications in 1265 their own address space using seccomp. Once seccomp is 1266 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1267 and the task is only allowed to execute a few safe syscalls 1268 defined by each seccomp mode. 1269 1270 If unsure, say Y. Only embedded should say N here. 1271 1272config CC_STACKPROTECTOR 1273 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" 1274 depends on X86_64 && EXPERIMENTAL && BROKEN 1275 help 1276 This option turns on the -fstack-protector GCC feature. This 1277 feature puts, at the beginning of critical functions, a canary 1278 value on the stack just before the return address, and validates 1279 the value just before actually returning. Stack based buffer 1280 overflows (that need to overwrite this return address) now also 1281 overwrite the canary, which gets detected and the attack is then 1282 neutralized via a kernel panic. 1283 1284 This feature requires gcc version 4.2 or above, or a distribution 1285 gcc with the feature backported. Older versions are automatically 1286 detected and for those versions, this configuration option is ignored. 1287 1288config CC_STACKPROTECTOR_ALL 1289 bool "Use stack-protector for all functions" 1290 depends on CC_STACKPROTECTOR 1291 help 1292 Normally, GCC only inserts the canary value protection for 1293 functions that use large-ish on-stack buffers. By enabling 1294 this option, GCC will be asked to do this for ALL functions. 1295 1296source kernel/Kconfig.hz 1297 1298config KEXEC 1299 bool "kexec system call" 1300 depends on X86_BIOS_REBOOT 1301 help 1302 kexec is a system call that implements the ability to shutdown your 1303 current kernel, and to start another kernel. It is like a reboot 1304 but it is independent of the system firmware. And like a reboot 1305 you can start any kernel with it, not just Linux. 1306 1307 The name comes from the similarity to the exec system call. 1308 1309 It is an ongoing process to be certain the hardware in a machine 1310 is properly shutdown, so do not be surprised if this code does not 1311 initially work for you. It may help to enable device hotplugging 1312 support. As of this writing the exact hardware interface is 1313 strongly in flux, so no good recommendation can be made. 1314 1315config CRASH_DUMP 1316 bool "kernel crash dumps" 1317 depends on X86_64 || (X86_32 && HIGHMEM) 1318 help 1319 Generate crash dump after being started by kexec. 1320 This should be normally only set in special crash dump kernels 1321 which are loaded in the main kernel with kexec-tools into 1322 a specially reserved region and then later executed after 1323 a crash by kdump/kexec. The crash dump kernel must be compiled 1324 to a memory address not used by the main kernel or BIOS using 1325 PHYSICAL_START, or it must be built as a relocatable image 1326 (CONFIG_RELOCATABLE=y). 1327 For more details see Documentation/kdump/kdump.txt 1328 1329config KEXEC_JUMP 1330 bool "kexec jump (EXPERIMENTAL)" 1331 depends on EXPERIMENTAL 1332 depends on KEXEC && HIBERNATION && X86_32 1333 help 1334 Jump between original kernel and kexeced kernel and invoke 1335 code in physical address mode via KEXEC 1336 1337config PHYSICAL_START 1338 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) 1339 default "0x1000000" if X86_NUMAQ 1340 default "0x200000" if X86_64 1341 default "0x100000" 1342 help 1343 This gives the physical address where the kernel is loaded. 1344 1345 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1346 bzImage will decompress itself to above physical address and 1347 run from there. Otherwise, bzImage will run from the address where 1348 it has been loaded by the boot loader and will ignore above physical 1349 address. 1350 1351 In normal kdump cases one does not have to set/change this option 1352 as now bzImage can be compiled as a completely relocatable image 1353 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1354 address. This option is mainly useful for the folks who don't want 1355 to use a bzImage for capturing the crash dump and want to use a 1356 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1357 to be specifically compiled to run from a specific memory area 1358 (normally a reserved region) and this option comes handy. 1359 1360 So if you are using bzImage for capturing the crash dump, leave 1361 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y. 1362 Otherwise if you plan to use vmlinux for capturing the crash dump 1363 change this value to start of the reserved region (Typically 16MB 1364 0x1000000). In other words, it can be set based on the "X" value as 1365 specified in the "crashkernel=YM@XM" command line boot parameter 1366 passed to the panic-ed kernel. Typically this parameter is set as 1367 crashkernel=64M@16M. Please take a look at 1368 Documentation/kdump/kdump.txt for more details about crash dumps. 1369 1370 Usage of bzImage for capturing the crash dump is recommended as 1371 one does not have to build two kernels. Same kernel can be used 1372 as production kernel and capture kernel. Above option should have 1373 gone away after relocatable bzImage support is introduced. But it 1374 is present because there are users out there who continue to use 1375 vmlinux for dump capture. This option should go away down the 1376 line. 1377 1378 Don't change this unless you know what you are doing. 1379 1380config RELOCATABLE 1381 bool "Build a relocatable kernel (EXPERIMENTAL)" 1382 depends on EXPERIMENTAL 1383 help 1384 This builds a kernel image that retains relocation information 1385 so it can be loaded someplace besides the default 1MB. 1386 The relocations tend to make the kernel binary about 10% larger, 1387 but are discarded at runtime. 1388 1389 One use is for the kexec on panic case where the recovery kernel 1390 must live at a different physical address than the primary 1391 kernel. 1392 1393 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1394 it has been loaded at and the compile time physical address 1395 (CONFIG_PHYSICAL_START) is ignored. 1396 1397config PHYSICAL_ALIGN 1398 hex 1399 prompt "Alignment value to which kernel should be aligned" if X86_32 1400 default "0x100000" if X86_32 1401 default "0x200000" if X86_64 1402 range 0x2000 0x400000 1403 help 1404 This value puts the alignment restrictions on physical address 1405 where kernel is loaded and run from. Kernel is compiled for an 1406 address which meets above alignment restriction. 1407 1408 If bootloader loads the kernel at a non-aligned address and 1409 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1410 address aligned to above value and run from there. 1411 1412 If bootloader loads the kernel at a non-aligned address and 1413 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1414 load address and decompress itself to the address it has been 1415 compiled for and run from there. The address for which kernel is 1416 compiled already meets above alignment restrictions. Hence the 1417 end result is that kernel runs from a physical address meeting 1418 above alignment restrictions. 1419 1420 Don't change this unless you know what you are doing. 1421 1422config HOTPLUG_CPU 1423 bool "Support for hot-pluggable CPUs" 1424 depends on SMP && HOTPLUG && !X86_VOYAGER 1425 ---help--- 1426 Say Y here to allow turning CPUs off and on. CPUs can be 1427 controlled through /sys/devices/system/cpu. 1428 ( Note: power management support will enable this option 1429 automatically on SMP systems. ) 1430 Say N if you want to disable CPU hotplug. 1431 1432config COMPAT_VDSO 1433 def_bool y 1434 prompt "Compat VDSO support" 1435 depends on X86_32 || IA32_EMULATION 1436 help 1437 Map the 32-bit VDSO to the predictable old-style address too. 1438 ---help--- 1439 Say N here if you are running a sufficiently recent glibc 1440 version (2.3.3 or later), to remove the high-mapped 1441 VDSO mapping and to exclusively use the randomized VDSO. 1442 1443 If unsure, say Y. 1444 1445config CMDLINE_BOOL 1446 bool "Built-in kernel command line" 1447 default n 1448 help 1449 Allow for specifying boot arguments to the kernel at 1450 build time. On some systems (e.g. embedded ones), it is 1451 necessary or convenient to provide some or all of the 1452 kernel boot arguments with the kernel itself (that is, 1453 to not rely on the boot loader to provide them.) 1454 1455 To compile command line arguments into the kernel, 1456 set this option to 'Y', then fill in the 1457 the boot arguments in CONFIG_CMDLINE. 1458 1459 Systems with fully functional boot loaders (i.e. non-embedded) 1460 should leave this option set to 'N'. 1461 1462config CMDLINE 1463 string "Built-in kernel command string" 1464 depends on CMDLINE_BOOL 1465 default "" 1466 help 1467 Enter arguments here that should be compiled into the kernel 1468 image and used at boot time. If the boot loader provides a 1469 command line at boot time, it is appended to this string to 1470 form the full kernel command line, when the system boots. 1471 1472 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1473 change this behavior. 1474 1475 In most cases, the command line (whether built-in or provided 1476 by the boot loader) should specify the device for the root 1477 file system. 1478 1479config CMDLINE_OVERRIDE 1480 bool "Built-in command line overrides boot loader arguments" 1481 default n 1482 depends on CMDLINE_BOOL 1483 help 1484 Set this option to 'Y' to have the kernel ignore the boot loader 1485 command line, and use ONLY the built-in command line. 1486 1487 This is used to work around broken boot loaders. This should 1488 be set to 'N' under normal conditions. 1489 1490endmenu 1491 1492config ARCH_ENABLE_MEMORY_HOTPLUG 1493 def_bool y 1494 depends on X86_64 || (X86_32 && HIGHMEM) 1495 1496config HAVE_ARCH_EARLY_PFN_TO_NID 1497 def_bool X86_64 1498 depends on NUMA 1499 1500menu "Power management and ACPI options" 1501 depends on !X86_VOYAGER 1502 1503config ARCH_HIBERNATION_HEADER 1504 def_bool y 1505 depends on X86_64 && HIBERNATION 1506 1507source "kernel/power/Kconfig" 1508 1509source "drivers/acpi/Kconfig" 1510 1511config X86_APM_BOOT 1512 bool 1513 default y 1514 depends on APM || APM_MODULE 1515 1516menuconfig APM 1517 tristate "APM (Advanced Power Management) BIOS support" 1518 depends on X86_32 && PM_SLEEP 1519 ---help--- 1520 APM is a BIOS specification for saving power using several different 1521 techniques. This is mostly useful for battery powered laptops with 1522 APM compliant BIOSes. If you say Y here, the system time will be 1523 reset after a RESUME operation, the /proc/apm device will provide 1524 battery status information, and user-space programs will receive 1525 notification of APM "events" (e.g. battery status change). 1526 1527 If you select "Y" here, you can disable actual use of the APM 1528 BIOS by passing the "apm=off" option to the kernel at boot time. 1529 1530 Note that the APM support is almost completely disabled for 1531 machines with more than one CPU. 1532 1533 In order to use APM, you will need supporting software. For location 1534 and more information, read <file:Documentation/power/pm.txt> and the 1535 Battery Powered Linux mini-HOWTO, available from 1536 <http://www.tldp.org/docs.html#howto>. 1537 1538 This driver does not spin down disk drives (see the hdparm(8) 1539 manpage ("man 8 hdparm") for that), and it doesn't turn off 1540 VESA-compliant "green" monitors. 1541 1542 This driver does not support the TI 4000M TravelMate and the ACER 1543 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1544 desktop machines also don't have compliant BIOSes, and this driver 1545 may cause those machines to panic during the boot phase. 1546 1547 Generally, if you don't have a battery in your machine, there isn't 1548 much point in using this driver and you should say N. If you get 1549 random kernel OOPSes or reboots that don't seem to be related to 1550 anything, try disabling/enabling this option (or disabling/enabling 1551 APM in your BIOS). 1552 1553 Some other things you should try when experiencing seemingly random, 1554 "weird" problems: 1555 1556 1) make sure that you have enough swap space and that it is 1557 enabled. 1558 2) pass the "no-hlt" option to the kernel 1559 3) switch on floating point emulation in the kernel and pass 1560 the "no387" option to the kernel 1561 4) pass the "floppy=nodma" option to the kernel 1562 5) pass the "mem=4M" option to the kernel (thereby disabling 1563 all but the first 4 MB of RAM) 1564 6) make sure that the CPU is not over clocked. 1565 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1566 8) disable the cache from your BIOS settings 1567 9) install a fan for the video card or exchange video RAM 1568 10) install a better fan for the CPU 1569 11) exchange RAM chips 1570 12) exchange the motherboard. 1571 1572 To compile this driver as a module, choose M here: the 1573 module will be called apm. 1574 1575if APM 1576 1577config APM_IGNORE_USER_SUSPEND 1578 bool "Ignore USER SUSPEND" 1579 help 1580 This option will ignore USER SUSPEND requests. On machines with a 1581 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1582 series notebooks, it is necessary to say Y because of a BIOS bug. 1583 1584config APM_DO_ENABLE 1585 bool "Enable PM at boot time" 1586 ---help--- 1587 Enable APM features at boot time. From page 36 of the APM BIOS 1588 specification: "When disabled, the APM BIOS does not automatically 1589 power manage devices, enter the Standby State, enter the Suspend 1590 State, or take power saving steps in response to CPU Idle calls." 1591 This driver will make CPU Idle calls when Linux is idle (unless this 1592 feature is turned off -- see "Do CPU IDLE calls", below). This 1593 should always save battery power, but more complicated APM features 1594 will be dependent on your BIOS implementation. You may need to turn 1595 this option off if your computer hangs at boot time when using APM 1596 support, or if it beeps continuously instead of suspending. Turn 1597 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1598 T400CDT. This is off by default since most machines do fine without 1599 this feature. 1600 1601config APM_CPU_IDLE 1602 bool "Make CPU Idle calls when idle" 1603 help 1604 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1605 On some machines, this can activate improved power savings, such as 1606 a slowed CPU clock rate, when the machine is idle. These idle calls 1607 are made after the idle loop has run for some length of time (e.g., 1608 333 mS). On some machines, this will cause a hang at boot time or 1609 whenever the CPU becomes idle. (On machines with more than one CPU, 1610 this option does nothing.) 1611 1612config APM_DISPLAY_BLANK 1613 bool "Enable console blanking using APM" 1614 help 1615 Enable console blanking using the APM. Some laptops can use this to 1616 turn off the LCD backlight when the screen blanker of the Linux 1617 virtual console blanks the screen. Note that this is only used by 1618 the virtual console screen blanker, and won't turn off the backlight 1619 when using the X Window system. This also doesn't have anything to 1620 do with your VESA-compliant power-saving monitor. Further, this 1621 option doesn't work for all laptops -- it might not turn off your 1622 backlight at all, or it might print a lot of errors to the console, 1623 especially if you are using gpm. 1624 1625config APM_ALLOW_INTS 1626 bool "Allow interrupts during APM BIOS calls" 1627 help 1628 Normally we disable external interrupts while we are making calls to 1629 the APM BIOS as a measure to lessen the effects of a badly behaving 1630 BIOS implementation. The BIOS should reenable interrupts if it 1631 needs to. Unfortunately, some BIOSes do not -- especially those in 1632 many of the newer IBM Thinkpads. If you experience hangs when you 1633 suspend, try setting this to Y. Otherwise, say N. 1634 1635config APM_REAL_MODE_POWER_OFF 1636 bool "Use real mode APM BIOS call to power off" 1637 help 1638 Use real mode APM BIOS calls to switch off the computer. This is 1639 a work-around for a number of buggy BIOSes. Switch this option on if 1640 your computer crashes instead of powering off properly. 1641 1642endif # APM 1643 1644source "arch/x86/kernel/cpu/cpufreq/Kconfig" 1645 1646source "drivers/cpuidle/Kconfig" 1647 1648source "drivers/idle/Kconfig" 1649 1650endmenu 1651 1652 1653menu "Bus options (PCI etc.)" 1654 1655config PCI 1656 bool "PCI support" 1657 default y 1658 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1659 help 1660 Find out whether you have a PCI motherboard. PCI is the name of a 1661 bus system, i.e. the way the CPU talks to the other stuff inside 1662 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1663 VESA. If you have PCI, say Y, otherwise N. 1664 1665choice 1666 prompt "PCI access mode" 1667 depends on X86_32 && PCI 1668 default PCI_GOANY 1669 ---help--- 1670 On PCI systems, the BIOS can be used to detect the PCI devices and 1671 determine their configuration. However, some old PCI motherboards 1672 have BIOS bugs and may crash if this is done. Also, some embedded 1673 PCI-based systems don't have any BIOS at all. Linux can also try to 1674 detect the PCI hardware directly without using the BIOS. 1675 1676 With this option, you can specify how Linux should detect the 1677 PCI devices. If you choose "BIOS", the BIOS will be used, 1678 if you choose "Direct", the BIOS won't be used, and if you 1679 choose "MMConfig", then PCI Express MMCONFIG will be used. 1680 If you choose "Any", the kernel will try MMCONFIG, then the 1681 direct access method and falls back to the BIOS if that doesn't 1682 work. If unsure, go with the default, which is "Any". 1683 1684config PCI_GOBIOS 1685 bool "BIOS" 1686 1687config PCI_GOMMCONFIG 1688 bool "MMConfig" 1689 1690config PCI_GODIRECT 1691 bool "Direct" 1692 1693config PCI_GOOLPC 1694 bool "OLPC" 1695 depends on OLPC 1696 1697config PCI_GOANY 1698 bool "Any" 1699 1700endchoice 1701 1702config PCI_BIOS 1703 def_bool y 1704 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 1705 1706# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 1707config PCI_DIRECT 1708 def_bool y 1709 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC)) 1710 1711config PCI_MMCONFIG 1712 def_bool y 1713 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY) 1714 1715config PCI_OLPC 1716 def_bool y 1717 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 1718 1719config PCI_DOMAINS 1720 def_bool y 1721 depends on PCI 1722 1723config PCI_MMCONFIG 1724 bool "Support mmconfig PCI config space access" 1725 depends on X86_64 && PCI && ACPI 1726 1727config DMAR 1728 bool "Support for DMA Remapping Devices (EXPERIMENTAL)" 1729 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL 1730 help 1731 DMA remapping (DMAR) devices support enables independent address 1732 translations for Direct Memory Access (DMA) from devices. 1733 These DMA remapping devices are reported via ACPI tables 1734 and include PCI device scope covered by these DMA 1735 remapping devices. 1736 1737config DMAR_GFX_WA 1738 def_bool y 1739 prompt "Support for Graphics workaround" 1740 depends on DMAR 1741 help 1742 Current Graphics drivers tend to use physical address 1743 for DMA and avoid using DMA APIs. Setting this config 1744 option permits the IOMMU driver to set a unity map for 1745 all the OS-visible memory. Hence the driver can continue 1746 to use physical addresses for DMA. 1747 1748config DMAR_FLOPPY_WA 1749 def_bool y 1750 depends on DMAR 1751 help 1752 Floppy disk drivers are know to bypass DMA API calls 1753 thereby failing to work when IOMMU is enabled. This 1754 workaround will setup a 1:1 mapping for the first 1755 16M to make floppy (an ISA device) work. 1756 1757config INTR_REMAP 1758 bool "Support for Interrupt Remapping (EXPERIMENTAL)" 1759 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL 1760 help 1761 Supports Interrupt remapping for IO-APIC and MSI devices. 1762 To use x2apic mode in the CPU's which support x2APIC enhancements or 1763 to support platforms with CPU's having > 8 bit APIC ID, say Y. 1764 1765source "drivers/pci/pcie/Kconfig" 1766 1767source "drivers/pci/Kconfig" 1768 1769# x86_64 have no ISA slots, but do have ISA-style DMA. 1770config ISA_DMA_API 1771 def_bool y 1772 1773if X86_32 1774 1775config ISA 1776 bool "ISA support" 1777 depends on !X86_VOYAGER 1778 help 1779 Find out whether you have ISA slots on your motherboard. ISA is the 1780 name of a bus system, i.e. the way the CPU talks to the other stuff 1781 inside your box. Other bus systems are PCI, EISA, MicroChannel 1782 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1783 newer boards don't support it. If you have ISA, say Y, otherwise N. 1784 1785config EISA 1786 bool "EISA support" 1787 depends on ISA 1788 ---help--- 1789 The Extended Industry Standard Architecture (EISA) bus was 1790 developed as an open alternative to the IBM MicroChannel bus. 1791 1792 The EISA bus provided some of the features of the IBM MicroChannel 1793 bus while maintaining backward compatibility with cards made for 1794 the older ISA bus. The EISA bus saw limited use between 1988 and 1795 1995 when it was made obsolete by the PCI bus. 1796 1797 Say Y here if you are building a kernel for an EISA-based machine. 1798 1799 Otherwise, say N. 1800 1801source "drivers/eisa/Kconfig" 1802 1803config MCA 1804 bool "MCA support" if !X86_VOYAGER 1805 default y if X86_VOYAGER 1806 help 1807 MicroChannel Architecture is found in some IBM PS/2 machines and 1808 laptops. It is a bus system similar to PCI or ISA. See 1809 <file:Documentation/mca.txt> (and especially the web page given 1810 there) before attempting to build an MCA bus kernel. 1811 1812source "drivers/mca/Kconfig" 1813 1814config SCx200 1815 tristate "NatSemi SCx200 support" 1816 depends on !X86_VOYAGER 1817 help 1818 This provides basic support for National Semiconductor's 1819 (now AMD's) Geode processors. The driver probes for the 1820 PCI-IDs of several on-chip devices, so its a good dependency 1821 for other scx200_* drivers. 1822 1823 If compiled as a module, the driver is named scx200. 1824 1825config SCx200HR_TIMER 1826 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 1827 depends on SCx200 && GENERIC_TIME 1828 default y 1829 help 1830 This driver provides a clocksource built upon the on-chip 1831 27MHz high-resolution timer. Its also a workaround for 1832 NSC Geode SC-1100's buggy TSC, which loses time when the 1833 processor goes idle (as is done by the scheduler). The 1834 other workaround is idle=poll boot option. 1835 1836config GEODE_MFGPT_TIMER 1837 def_bool y 1838 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events" 1839 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS 1840 help 1841 This driver provides a clock event source based on the MFGPT 1842 timer(s) in the CS5535 and CS5536 companion chip for the geode. 1843 MFGPTs have a better resolution and max interval than the 1844 generic PIT, and are suitable for use as high-res timers. 1845 1846config OLPC 1847 bool "One Laptop Per Child support" 1848 default n 1849 help 1850 Add support for detecting the unique features of the OLPC 1851 XO hardware. 1852 1853endif # X86_32 1854 1855config K8_NB 1856 def_bool y 1857 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA))) 1858 1859source "drivers/pcmcia/Kconfig" 1860 1861source "drivers/pci/hotplug/Kconfig" 1862 1863endmenu 1864 1865 1866menu "Executable file formats / Emulations" 1867 1868source "fs/Kconfig.binfmt" 1869 1870config IA32_EMULATION 1871 bool "IA32 Emulation" 1872 depends on X86_64 1873 select COMPAT_BINFMT_ELF 1874 help 1875 Include code to run 32-bit programs under a 64-bit kernel. You should 1876 likely turn this on, unless you're 100% sure that you don't have any 1877 32-bit programs left. 1878 1879config IA32_AOUT 1880 tristate "IA32 a.out support" 1881 depends on IA32_EMULATION 1882 help 1883 Support old a.out binaries in the 32bit emulation. 1884 1885config COMPAT 1886 def_bool y 1887 depends on IA32_EMULATION 1888 1889config COMPAT_FOR_U64_ALIGNMENT 1890 def_bool COMPAT 1891 depends on X86_64 1892 1893config SYSVIPC_COMPAT 1894 def_bool y 1895 depends on COMPAT && SYSVIPC 1896 1897endmenu 1898 1899 1900config HAVE_ATOMIC_IOMAP 1901 def_bool y 1902 depends on X86_32 1903 1904source "net/Kconfig" 1905 1906source "drivers/Kconfig" 1907 1908source "drivers/firmware/Kconfig" 1909 1910source "fs/Kconfig" 1911 1912source "arch/x86/Kconfig.debug" 1913 1914source "security/Kconfig" 1915 1916source "crypto/Kconfig" 1917 1918source "arch/x86/kvm/Kconfig" 1919 1920source "lib/Kconfig" 1921