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