1# 2# For a description of the syntax of this configuration file, 3# see Documentation/kbuild/kconfig-language.txt. 4# 5 6mainmenu "Linux Kernel Configuration" 7 8config X86_32 9 bool 10 default y 11 help 12 This is Linux's home port. Linux was originally native to the Intel 13 386, and runs on all the later x86 processors including the Intel 14 486, 586, Pentiums, and various instruction-set-compatible chips by 15 AMD, Cyrix, and others. 16 17config GENERIC_TIME 18 bool 19 default y 20 21config CLOCKSOURCE_WATCHDOG 22 bool 23 default y 24 25config GENERIC_CLOCKEVENTS 26 bool 27 default y 28 29config GENERIC_CLOCKEVENTS_BROADCAST 30 bool 31 default y 32 depends on X86_LOCAL_APIC 33 34config LOCKDEP_SUPPORT 35 bool 36 default y 37 38config STACKTRACE_SUPPORT 39 bool 40 default y 41 42config SEMAPHORE_SLEEPERS 43 bool 44 default y 45 46config X86 47 bool 48 default y 49 50config MMU 51 bool 52 default y 53 54config ZONE_DMA 55 bool 56 default y 57 58config QUICKLIST 59 bool 60 default y 61 62config SBUS 63 bool 64 65config GENERIC_ISA_DMA 66 bool 67 default y 68 69config GENERIC_IOMAP 70 bool 71 default y 72 73config GENERIC_BUG 74 bool 75 default y 76 depends on BUG 77 78config GENERIC_HWEIGHT 79 bool 80 default y 81 82config ARCH_MAY_HAVE_PC_FDC 83 bool 84 default y 85 86config DMI 87 bool 88 default y 89 90source "init/Kconfig" 91 92menu "Processor type and features" 93 94source "kernel/time/Kconfig" 95 96config SMP 97 bool "Symmetric multi-processing support" 98 ---help--- 99 This enables support for systems with more than one CPU. If you have 100 a system with only one CPU, like most personal computers, say N. If 101 you have a system with more than one CPU, say Y. 102 103 If you say N here, the kernel will run on single and multiprocessor 104 machines, but will use only one CPU of a multiprocessor machine. If 105 you say Y here, the kernel will run on many, but not all, 106 singleprocessor machines. On a singleprocessor machine, the kernel 107 will run faster if you say N here. 108 109 Note that if you say Y here and choose architecture "586" or 110 "Pentium" under "Processor family", the kernel will not work on 486 111 architectures. Similarly, multiprocessor kernels for the "PPro" 112 architecture may not work on all Pentium based boards. 113 114 People using multiprocessor machines who say Y here should also say 115 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 116 Management" code will be disabled if you say Y here. 117 118 See also the <file:Documentation/smp.txt>, 119 <file:Documentation/i386/IO-APIC.txt>, 120 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 121 <http://www.tldp.org/docs.html#howto>. 122 123 If you don't know what to do here, say N. 124 125choice 126 prompt "Subarchitecture Type" 127 default X86_PC 128 129config X86_PC 130 bool "PC-compatible" 131 help 132 Choose this option if your computer is a standard PC or compatible. 133 134config X86_ELAN 135 bool "AMD Elan" 136 help 137 Select this for an AMD Elan processor. 138 139 Do not use this option for K6/Athlon/Opteron processors! 140 141 If unsure, choose "PC-compatible" instead. 142 143config X86_VOYAGER 144 bool "Voyager (NCR)" 145 help 146 Voyager is an MCA-based 32-way capable SMP architecture proprietary 147 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based. 148 149 *** WARNING *** 150 151 If you do not specifically know you have a Voyager based machine, 152 say N here, otherwise the kernel you build will not be bootable. 153 154config X86_NUMAQ 155 bool "NUMAQ (IBM/Sequent)" 156 select SMP 157 select NUMA 158 help 159 This option is used for getting Linux to run on a (IBM/Sequent) NUMA 160 multiquad box. This changes the way that processors are bootstrapped, 161 and uses Clustered Logical APIC addressing mode instead of Flat Logical. 162 You will need a new lynxer.elf file to flash your firmware with - send 163 email to <Martin.Bligh@us.ibm.com>. 164 165config X86_SUMMIT 166 bool "Summit/EXA (IBM x440)" 167 depends on SMP 168 help 169 This option is needed for IBM systems that use the Summit/EXA chipset. 170 In particular, it is needed for the x440. 171 172 If you don't have one of these computers, you should say N here. 173 If you want to build a NUMA kernel, you must select ACPI. 174 175config X86_BIGSMP 176 bool "Support for other sub-arch SMP systems with more than 8 CPUs" 177 depends on SMP 178 help 179 This option is needed for the systems that have more than 8 CPUs 180 and if the system is not of any sub-arch type above. 181 182 If you don't have such a system, you should say N here. 183 184config X86_VISWS 185 bool "SGI 320/540 (Visual Workstation)" 186 help 187 The SGI Visual Workstation series is an IA32-based workstation 188 based on SGI systems chips with some legacy PC hardware attached. 189 190 Say Y here to create a kernel to run on the SGI 320 or 540. 191 192 A kernel compiled for the Visual Workstation will not run on PCs 193 and vice versa. See <file:Documentation/sgi-visws.txt> for details. 194 195config X86_GENERICARCH 196 bool "Generic architecture (Summit, bigsmp, ES7000, default)" 197 help 198 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures. 199 It is intended for a generic binary kernel. 200 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA. 201 202config X86_ES7000 203 bool "Support for Unisys ES7000 IA32 series" 204 depends on SMP 205 help 206 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 207 supposed to run on an IA32-based Unisys ES7000 system. 208 Only choose this option if you have such a system, otherwise you 209 should say N here. 210 211endchoice 212 213config PARAVIRT 214 bool "Paravirtualization support (EXPERIMENTAL)" 215 depends on EXPERIMENTAL 216 depends on !(X86_VISWS || X86_VOYAGER) 217 help 218 Paravirtualization is a way of running multiple instances of 219 Linux on the same machine, under a hypervisor. This option 220 changes the kernel so it can modify itself when it is run 221 under a hypervisor, improving performance significantly. 222 However, when run without a hypervisor the kernel is 223 theoretically slower. If in doubt, say N. 224 225config VMI 226 bool "VMI Paravirt-ops support" 227 depends on PARAVIRT 228 help 229 VMI provides a paravirtualized interface to the VMware ESX server 230 (it could be used by other hypervisors in theory too, but is not 231 at the moment), by linking the kernel to a GPL-ed ROM module 232 provided by the hypervisor. 233 234config ACPI_SRAT 235 bool 236 default y 237 depends on ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH) 238 select ACPI_NUMA 239 240config HAVE_ARCH_PARSE_SRAT 241 bool 242 default y 243 depends on ACPI_SRAT 244 245config X86_SUMMIT_NUMA 246 bool 247 default y 248 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH) 249 250config X86_CYCLONE_TIMER 251 bool 252 default y 253 depends on X86_SUMMIT || X86_GENERICARCH 254 255config ES7000_CLUSTERED_APIC 256 bool 257 default y 258 depends on SMP && X86_ES7000 && MPENTIUMIII 259 260source "arch/i386/Kconfig.cpu" 261 262config HPET_TIMER 263 bool "HPET Timer Support" 264 help 265 This enables the use of the HPET for the kernel's internal timer. 266 HPET is the next generation timer replacing legacy 8254s. 267 You can safely choose Y here. However, HPET will only be 268 activated if the platform and the BIOS support this feature. 269 Otherwise the 8254 will be used for timing services. 270 271 Choose N to continue using the legacy 8254 timer. 272 273config HPET_EMULATE_RTC 274 bool 275 depends on HPET_TIMER && RTC=y 276 default y 277 278config NR_CPUS 279 int "Maximum number of CPUs (2-255)" 280 range 2 255 281 depends on SMP 282 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000 283 default "8" 284 help 285 This allows you to specify the maximum number of CPUs which this 286 kernel will support. The maximum supported value is 255 and the 287 minimum value which makes sense is 2. 288 289 This is purely to save memory - each supported CPU adds 290 approximately eight kilobytes to the kernel image. 291 292config SCHED_SMT 293 bool "SMT (Hyperthreading) scheduler support" 294 depends on X86_HT 295 help 296 SMT scheduler support improves the CPU scheduler's decision making 297 when dealing with Intel Pentium 4 chips with HyperThreading at a 298 cost of slightly increased overhead in some places. If unsure say 299 N here. 300 301config SCHED_MC 302 bool "Multi-core scheduler support" 303 depends on X86_HT 304 default y 305 help 306 Multi-core scheduler support improves the CPU scheduler's decision 307 making when dealing with multi-core CPU chips at a cost of slightly 308 increased overhead in some places. If unsure say N here. 309 310source "kernel/Kconfig.preempt" 311 312config X86_UP_APIC 313 bool "Local APIC support on uniprocessors" 314 depends on !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH) 315 help 316 A local APIC (Advanced Programmable Interrupt Controller) is an 317 integrated interrupt controller in the CPU. If you have a single-CPU 318 system which has a processor with a local APIC, you can say Y here to 319 enable and use it. If you say Y here even though your machine doesn't 320 have a local APIC, then the kernel will still run with no slowdown at 321 all. The local APIC supports CPU-generated self-interrupts (timer, 322 performance counters), and the NMI watchdog which detects hard 323 lockups. 324 325config X86_UP_IOAPIC 326 bool "IO-APIC support on uniprocessors" 327 depends on X86_UP_APIC 328 help 329 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 330 SMP-capable replacement for PC-style interrupt controllers. Most 331 SMP systems and many recent uniprocessor systems have one. 332 333 If you have a single-CPU system with an IO-APIC, you can say Y here 334 to use it. If you say Y here even though your machine doesn't have 335 an IO-APIC, then the kernel will still run with no slowdown at all. 336 337config X86_LOCAL_APIC 338 bool 339 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH 340 default y 341 342config X86_IO_APIC 343 bool 344 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH 345 default y 346 347config X86_VISWS_APIC 348 bool 349 depends on X86_VISWS 350 default y 351 352config X86_MCE 353 bool "Machine Check Exception" 354 depends on !X86_VOYAGER 355 ---help--- 356 Machine Check Exception support allows the processor to notify the 357 kernel if it detects a problem (e.g. overheating, component failure). 358 The action the kernel takes depends on the severity of the problem, 359 ranging from a warning message on the console, to halting the machine. 360 Your processor must be a Pentium or newer to support this - check the 361 flags in /proc/cpuinfo for mce. Note that some older Pentium systems 362 have a design flaw which leads to false MCE events - hence MCE is 363 disabled on all P5 processors, unless explicitly enabled with "mce" 364 as a boot argument. Similarly, if MCE is built in and creates a 365 problem on some new non-standard machine, you can boot with "nomce" 366 to disable it. MCE support simply ignores non-MCE processors like 367 the 386 and 486, so nearly everyone can say Y here. 368 369config X86_MCE_NONFATAL 370 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" 371 depends on X86_MCE 372 help 373 Enabling this feature starts a timer that triggers every 5 seconds which 374 will look at the machine check registers to see if anything happened. 375 Non-fatal problems automatically get corrected (but still logged). 376 Disable this if you don't want to see these messages. 377 Seeing the messages this option prints out may be indicative of dying hardware, 378 or out-of-spec (ie, overclocked) hardware. 379 This option only does something on certain CPUs. 380 (AMD Athlon/Duron and Intel Pentium 4) 381 382config X86_MCE_P4THERMAL 383 bool "check for P4 thermal throttling interrupt." 384 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS 385 help 386 Enabling this feature will cause a message to be printed when the P4 387 enters thermal throttling. 388 389config VM86 390 default y 391 bool "Enable VM86 support" if EMBEDDED 392 help 393 This option is required by programs like DOSEMU to run 16-bit legacy 394 code on X86 processors. It also may be needed by software like 395 XFree86 to initialize some video cards via BIOS. Disabling this 396 option saves about 6k. 397 398config TOSHIBA 399 tristate "Toshiba Laptop support" 400 ---help--- 401 This adds a driver to safely access the System Management Mode of 402 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 403 not work on models with a Phoenix BIOS. The System Management Mode 404 is used to set the BIOS and power saving options on Toshiba portables. 405 406 For information on utilities to make use of this driver see the 407 Toshiba Linux utilities web site at: 408 <http://www.buzzard.org.uk/toshiba/>. 409 410 Say Y if you intend to run this kernel on a Toshiba portable. 411 Say N otherwise. 412 413config I8K 414 tristate "Dell laptop support" 415 ---help--- 416 This adds a driver to safely access the System Management Mode 417 of the CPU on the Dell Inspiron 8000. The System Management Mode 418 is used to read cpu temperature and cooling fan status and to 419 control the fans on the I8K portables. 420 421 This driver has been tested only on the Inspiron 8000 but it may 422 also work with other Dell laptops. You can force loading on other 423 models by passing the parameter `force=1' to the module. Use at 424 your own risk. 425 426 For information on utilities to make use of this driver see the 427 I8K Linux utilities web site at: 428 <http://people.debian.org/~dz/i8k/> 429 430 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 431 Say N otherwise. 432 433config X86_REBOOTFIXUPS 434 bool "Enable X86 board specific fixups for reboot" 435 depends on X86 436 default n 437 ---help--- 438 This enables chipset and/or board specific fixups to be done 439 in order to get reboot to work correctly. This is only needed on 440 some combinations of hardware and BIOS. The symptom, for which 441 this config is intended, is when reboot ends with a stalled/hung 442 system. 443 444 Currently, the only fixup is for the Geode machines using 445 CS5530A and CS5536 chipsets. 446 447 Say Y if you want to enable the fixup. Currently, it's safe to 448 enable this option even if you don't need it. 449 Say N otherwise. 450 451config MICROCODE 452 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support" 453 select FW_LOADER 454 ---help--- 455 If you say Y here and also to "/dev file system support" in the 456 'File systems' section, you will be able to update the microcode on 457 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II, 458 Pentium III, Pentium 4, Xeon etc. You will obviously need the 459 actual microcode binary data itself which is not shipped with the 460 Linux kernel. 461 462 For latest news and information on obtaining all the required 463 ingredients for this driver, check: 464 <http://www.urbanmyth.org/microcode/>. 465 466 To compile this driver as a module, choose M here: the 467 module will be called microcode. 468 469config MICROCODE_OLD_INTERFACE 470 bool 471 depends on MICROCODE 472 default y 473 474config X86_MSR 475 tristate "/dev/cpu/*/msr - Model-specific register support" 476 help 477 This device gives privileged processes access to the x86 478 Model-Specific Registers (MSRs). It is a character device with 479 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 480 MSR accesses are directed to a specific CPU on multi-processor 481 systems. 482 483config X86_CPUID 484 tristate "/dev/cpu/*/cpuid - CPU information support" 485 help 486 This device gives processes access to the x86 CPUID instruction to 487 be executed on a specific processor. It is a character device 488 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 489 /dev/cpu/31/cpuid. 490 491source "drivers/firmware/Kconfig" 492 493choice 494 prompt "High Memory Support" 495 default HIGHMEM4G if !X86_NUMAQ 496 default HIGHMEM64G if X86_NUMAQ 497 498config NOHIGHMEM 499 bool "off" 500 depends on !X86_NUMAQ 501 ---help--- 502 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 503 However, the address space of 32-bit x86 processors is only 4 504 Gigabytes large. That means that, if you have a large amount of 505 physical memory, not all of it can be "permanently mapped" by the 506 kernel. The physical memory that's not permanently mapped is called 507 "high memory". 508 509 If you are compiling a kernel which will never run on a machine with 510 more than 1 Gigabyte total physical RAM, answer "off" here (default 511 choice and suitable for most users). This will result in a "3GB/1GB" 512 split: 3GB are mapped so that each process sees a 3GB virtual memory 513 space and the remaining part of the 4GB virtual memory space is used 514 by the kernel to permanently map as much physical memory as 515 possible. 516 517 If the machine has between 1 and 4 Gigabytes physical RAM, then 518 answer "4GB" here. 519 520 If more than 4 Gigabytes is used then answer "64GB" here. This 521 selection turns Intel PAE (Physical Address Extension) mode on. 522 PAE implements 3-level paging on IA32 processors. PAE is fully 523 supported by Linux, PAE mode is implemented on all recent Intel 524 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 525 then the kernel will not boot on CPUs that don't support PAE! 526 527 The actual amount of total physical memory will either be 528 auto detected or can be forced by using a kernel command line option 529 such as "mem=256M". (Try "man bootparam" or see the documentation of 530 your boot loader (lilo or loadlin) about how to pass options to the 531 kernel at boot time.) 532 533 If unsure, say "off". 534 535config HIGHMEM4G 536 bool "4GB" 537 depends on !X86_NUMAQ 538 help 539 Select this if you have a 32-bit processor and between 1 and 4 540 gigabytes of physical RAM. 541 542config HIGHMEM64G 543 bool "64GB" 544 depends on !M386 && !M486 545 help 546 Select this if you have a 32-bit processor and more than 4 547 gigabytes of physical RAM. 548 549endchoice 550 551choice 552 depends on EXPERIMENTAL 553 prompt "Memory split" if EMBEDDED 554 default VMSPLIT_3G 555 help 556 Select the desired split between kernel and user memory. 557 558 If the address range available to the kernel is less than the 559 physical memory installed, the remaining memory will be available 560 as "high memory". Accessing high memory is a little more costly 561 than low memory, as it needs to be mapped into the kernel first. 562 Note that increasing the kernel address space limits the range 563 available to user programs, making the address space there 564 tighter. Selecting anything other than the default 3G/1G split 565 will also likely make your kernel incompatible with binary-only 566 kernel modules. 567 568 If you are not absolutely sure what you are doing, leave this 569 option alone! 570 571 config VMSPLIT_3G 572 bool "3G/1G user/kernel split" 573 config VMSPLIT_3G_OPT 574 depends on !HIGHMEM 575 bool "3G/1G user/kernel split (for full 1G low memory)" 576 config VMSPLIT_2G 577 bool "2G/2G user/kernel split" 578 config VMSPLIT_2G_OPT 579 depends on !HIGHMEM 580 bool "2G/2G user/kernel split (for full 2G low memory)" 581 config VMSPLIT_1G 582 bool "1G/3G user/kernel split" 583endchoice 584 585config PAGE_OFFSET 586 hex 587 default 0xB0000000 if VMSPLIT_3G_OPT 588 default 0x80000000 if VMSPLIT_2G 589 default 0x78000000 if VMSPLIT_2G_OPT 590 default 0x40000000 if VMSPLIT_1G 591 default 0xC0000000 592 593config HIGHMEM 594 bool 595 depends on HIGHMEM64G || HIGHMEM4G 596 default y 597 598config X86_PAE 599 bool 600 depends on HIGHMEM64G 601 default y 602 select RESOURCES_64BIT 603 604# Common NUMA Features 605config NUMA 606 bool "Numa Memory Allocation and Scheduler Support" 607 depends on SMP && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) 608 default n if X86_PC 609 default y if (X86_NUMAQ || X86_SUMMIT) 610 611comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 612 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI) 613 614config NODES_SHIFT 615 int 616 default "4" if X86_NUMAQ 617 default "3" 618 depends on NEED_MULTIPLE_NODES 619 620config HAVE_ARCH_BOOTMEM_NODE 621 bool 622 depends on NUMA 623 default y 624 625config ARCH_HAVE_MEMORY_PRESENT 626 bool 627 depends on DISCONTIGMEM 628 default y 629 630config NEED_NODE_MEMMAP_SIZE 631 bool 632 depends on DISCONTIGMEM || SPARSEMEM 633 default y 634 635config HAVE_ARCH_ALLOC_REMAP 636 bool 637 depends on NUMA 638 default y 639 640config ARCH_FLATMEM_ENABLE 641 def_bool y 642 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC) 643 644config ARCH_DISCONTIGMEM_ENABLE 645 def_bool y 646 depends on NUMA 647 648config ARCH_DISCONTIGMEM_DEFAULT 649 def_bool y 650 depends on NUMA 651 652config ARCH_SPARSEMEM_ENABLE 653 def_bool y 654 depends on (NUMA || (X86_PC && EXPERIMENTAL)) 655 select SPARSEMEM_STATIC 656 657config ARCH_SELECT_MEMORY_MODEL 658 def_bool y 659 depends on ARCH_SPARSEMEM_ENABLE 660 661config ARCH_POPULATES_NODE_MAP 662 def_bool y 663 664source "mm/Kconfig" 665 666config HIGHPTE 667 bool "Allocate 3rd-level pagetables from highmem" 668 depends on HIGHMEM4G || HIGHMEM64G 669 help 670 The VM uses one page table entry for each page of physical memory. 671 For systems with a lot of RAM, this can be wasteful of precious 672 low memory. Setting this option will put user-space page table 673 entries in high memory. 674 675config MATH_EMULATION 676 bool "Math emulation" 677 ---help--- 678 Linux can emulate a math coprocessor (used for floating point 679 operations) if you don't have one. 486DX and Pentium processors have 680 a math coprocessor built in, 486SX and 386 do not, unless you added 681 a 487DX or 387, respectively. (The messages during boot time can 682 give you some hints here ["man dmesg"].) Everyone needs either a 683 coprocessor or this emulation. 684 685 If you don't have a math coprocessor, you need to say Y here; if you 686 say Y here even though you have a coprocessor, the coprocessor will 687 be used nevertheless. (This behavior can be changed with the kernel 688 command line option "no387", which comes handy if your coprocessor 689 is broken. Try "man bootparam" or see the documentation of your boot 690 loader (lilo or loadlin) about how to pass options to the kernel at 691 boot time.) This means that it is a good idea to say Y here if you 692 intend to use this kernel on different machines. 693 694 More information about the internals of the Linux math coprocessor 695 emulation can be found in <file:arch/i386/math-emu/README>. 696 697 If you are not sure, say Y; apart from resulting in a 66 KB bigger 698 kernel, it won't hurt. 699 700config MTRR 701 bool "MTRR (Memory Type Range Register) support" 702 ---help--- 703 On Intel P6 family processors (Pentium Pro, Pentium II and later) 704 the Memory Type Range Registers (MTRRs) may be used to control 705 processor access to memory ranges. This is most useful if you have 706 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 707 allows bus write transfers to be combined into a larger transfer 708 before bursting over the PCI/AGP bus. This can increase performance 709 of image write operations 2.5 times or more. Saying Y here creates a 710 /proc/mtrr file which may be used to manipulate your processor's 711 MTRRs. Typically the X server should use this. 712 713 This code has a reasonably generic interface so that similar 714 control registers on other processors can be easily supported 715 as well: 716 717 The Cyrix 6x86, 6x86MX and M II processors have Address Range 718 Registers (ARRs) which provide a similar functionality to MTRRs. For 719 these, the ARRs are used to emulate the MTRRs. 720 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 721 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 722 write-combining. All of these processors are supported by this code 723 and it makes sense to say Y here if you have one of them. 724 725 Saying Y here also fixes a problem with buggy SMP BIOSes which only 726 set the MTRRs for the boot CPU and not for the secondary CPUs. This 727 can lead to all sorts of problems, so it's good to say Y here. 728 729 You can safely say Y even if your machine doesn't have MTRRs, you'll 730 just add about 9 KB to your kernel. 731 732 See <file:Documentation/mtrr.txt> for more information. 733 734config EFI 735 bool "Boot from EFI support" 736 depends on ACPI 737 default n 738 ---help--- 739 This enables the kernel to boot on EFI platforms using 740 system configuration information passed to it from the firmware. 741 This also enables the kernel to use any EFI runtime services that are 742 available (such as the EFI variable services). 743 744 This option is only useful on systems that have EFI firmware 745 and will result in a kernel image that is ~8k larger. In addition, 746 you must use the latest ELILO loader available at 747 <http://elilo.sourceforge.net> in order to take advantage of 748 kernel initialization using EFI information (neither GRUB nor LILO know 749 anything about EFI). However, even with this option, the resultant 750 kernel should continue to boot on existing non-EFI platforms. 751 752config IRQBALANCE 753 bool "Enable kernel irq balancing" 754 depends on SMP && X86_IO_APIC 755 default y 756 help 757 The default yes will allow the kernel to do irq load balancing. 758 Saying no will keep the kernel from doing irq load balancing. 759 760# turning this on wastes a bunch of space. 761# Summit needs it only when NUMA is on 762config BOOT_IOREMAP 763 bool 764 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI)) 765 default y 766 767config SECCOMP 768 bool "Enable seccomp to safely compute untrusted bytecode" 769 depends on PROC_FS 770 default y 771 help 772 This kernel feature is useful for number crunching applications 773 that may need to compute untrusted bytecode during their 774 execution. By using pipes or other transports made available to 775 the process as file descriptors supporting the read/write 776 syscalls, it's possible to isolate those applications in 777 their own address space using seccomp. Once seccomp is 778 enabled via /proc/<pid>/seccomp, it cannot be disabled 779 and the task is only allowed to execute a few safe syscalls 780 defined by each seccomp mode. 781 782 If unsure, say Y. Only embedded should say N here. 783 784source kernel/Kconfig.hz 785 786config KEXEC 787 bool "kexec system call" 788 help 789 kexec is a system call that implements the ability to shutdown your 790 current kernel, and to start another kernel. It is like a reboot 791 but it is independent of the system firmware. And like a reboot 792 you can start any kernel with it, not just Linux. 793 794 The name comes from the similarity to the exec system call. 795 796 It is an ongoing process to be certain the hardware in a machine 797 is properly shutdown, so do not be surprised if this code does not 798 initially work for you. It may help to enable device hotplugging 799 support. As of this writing the exact hardware interface is 800 strongly in flux, so no good recommendation can be made. 801 802config CRASH_DUMP 803 bool "kernel crash dumps (EXPERIMENTAL)" 804 depends on EXPERIMENTAL 805 depends on HIGHMEM 806 help 807 Generate crash dump after being started by kexec. 808 This should be normally only set in special crash dump kernels 809 which are loaded in the main kernel with kexec-tools into 810 a specially reserved region and then later executed after 811 a crash by kdump/kexec. The crash dump kernel must be compiled 812 to a memory address not used by the main kernel or BIOS using 813 PHYSICAL_START. 814 For more details see Documentation/kdump/kdump.txt 815 816config PHYSICAL_START 817 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) 818 default "0x100000" 819 help 820 This gives the physical address where the kernel is loaded. 821 822 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 823 bzImage will decompress itself to above physical address and 824 run from there. Otherwise, bzImage will run from the address where 825 it has been loaded by the boot loader and will ignore above physical 826 address. 827 828 In normal kdump cases one does not have to set/change this option 829 as now bzImage can be compiled as a completely relocatable image 830 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 831 address. This option is mainly useful for the folks who don't want 832 to use a bzImage for capturing the crash dump and want to use a 833 vmlinux instead. vmlinux is not relocatable hence a kernel needs 834 to be specifically compiled to run from a specific memory area 835 (normally a reserved region) and this option comes handy. 836 837 So if you are using bzImage for capturing the crash dump, leave 838 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y. 839 Otherwise if you plan to use vmlinux for capturing the crash dump 840 change this value to start of the reserved region (Typically 16MB 841 0x1000000). In other words, it can be set based on the "X" value as 842 specified in the "crashkernel=YM@XM" command line boot parameter 843 passed to the panic-ed kernel. Typically this parameter is set as 844 crashkernel=64M@16M. Please take a look at 845 Documentation/kdump/kdump.txt for more details about crash dumps. 846 847 Usage of bzImage for capturing the crash dump is recommended as 848 one does not have to build two kernels. Same kernel can be used 849 as production kernel and capture kernel. Above option should have 850 gone away after relocatable bzImage support is introduced. But it 851 is present because there are users out there who continue to use 852 vmlinux for dump capture. This option should go away down the 853 line. 854 855 Don't change this unless you know what you are doing. 856 857config RELOCATABLE 858 bool "Build a relocatable kernel(EXPERIMENTAL)" 859 depends on EXPERIMENTAL 860 help 861 This builds a kernel image that retains relocation information 862 so it can be loaded someplace besides the default 1MB. 863 The relocations tend to make the kernel binary about 10% larger, 864 but are discarded at runtime. 865 866 One use is for the kexec on panic case where the recovery kernel 867 must live at a different physical address than the primary 868 kernel. 869 870config PHYSICAL_ALIGN 871 hex "Alignment value to which kernel should be aligned" 872 default "0x100000" 873 range 0x2000 0x400000 874 help 875 This value puts the alignment restrictions on physical address 876 where kernel is loaded and run from. Kernel is compiled for an 877 address which meets above alignment restriction. 878 879 If bootloader loads the kernel at a non-aligned address and 880 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 881 address aligned to above value and run from there. 882 883 If bootloader loads the kernel at a non-aligned address and 884 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 885 load address and decompress itself to the address it has been 886 compiled for and run from there. The address for which kernel is 887 compiled already meets above alignment restrictions. Hence the 888 end result is that kernel runs from a physical address meeting 889 above alignment restrictions. 890 891 Don't change this unless you know what you are doing. 892 893config HOTPLUG_CPU 894 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)" 895 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER 896 ---help--- 897 Say Y here to experiment with turning CPUs off and on, and to 898 enable suspend on SMP systems. CPUs can be controlled through 899 /sys/devices/system/cpu. 900 901config COMPAT_VDSO 902 bool "Compat VDSO support" 903 default y 904 help 905 Map the VDSO to the predictable old-style address too. 906 ---help--- 907 Say N here if you are running a sufficiently recent glibc 908 version (2.3.3 or later), to remove the high-mapped 909 VDSO mapping and to exclusively use the randomized VDSO. 910 911 If unsure, say Y. 912 913endmenu 914 915config ARCH_ENABLE_MEMORY_HOTPLUG 916 def_bool y 917 depends on HIGHMEM 918 919menu "Power management options (ACPI, APM)" 920 depends on !X86_VOYAGER 921 922source kernel/power/Kconfig 923 924source "drivers/acpi/Kconfig" 925 926menuconfig APM 927 tristate "APM (Advanced Power Management) BIOS support" 928 depends on PM && !X86_VISWS 929 ---help--- 930 APM is a BIOS specification for saving power using several different 931 techniques. This is mostly useful for battery powered laptops with 932 APM compliant BIOSes. If you say Y here, the system time will be 933 reset after a RESUME operation, the /proc/apm device will provide 934 battery status information, and user-space programs will receive 935 notification of APM "events" (e.g. battery status change). 936 937 If you select "Y" here, you can disable actual use of the APM 938 BIOS by passing the "apm=off" option to the kernel at boot time. 939 940 Note that the APM support is almost completely disabled for 941 machines with more than one CPU. 942 943 In order to use APM, you will need supporting software. For location 944 and more information, read <file:Documentation/pm.txt> and the 945 Battery Powered Linux mini-HOWTO, available from 946 <http://www.tldp.org/docs.html#howto>. 947 948 This driver does not spin down disk drives (see the hdparm(8) 949 manpage ("man 8 hdparm") for that), and it doesn't turn off 950 VESA-compliant "green" monitors. 951 952 This driver does not support the TI 4000M TravelMate and the ACER 953 486/DX4/75 because they don't have compliant BIOSes. Many "green" 954 desktop machines also don't have compliant BIOSes, and this driver 955 may cause those machines to panic during the boot phase. 956 957 Generally, if you don't have a battery in your machine, there isn't 958 much point in using this driver and you should say N. If you get 959 random kernel OOPSes or reboots that don't seem to be related to 960 anything, try disabling/enabling this option (or disabling/enabling 961 APM in your BIOS). 962 963 Some other things you should try when experiencing seemingly random, 964 "weird" problems: 965 966 1) make sure that you have enough swap space and that it is 967 enabled. 968 2) pass the "no-hlt" option to the kernel 969 3) switch on floating point emulation in the kernel and pass 970 the "no387" option to the kernel 971 4) pass the "floppy=nodma" option to the kernel 972 5) pass the "mem=4M" option to the kernel (thereby disabling 973 all but the first 4 MB of RAM) 974 6) make sure that the CPU is not over clocked. 975 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 976 8) disable the cache from your BIOS settings 977 9) install a fan for the video card or exchange video RAM 978 10) install a better fan for the CPU 979 11) exchange RAM chips 980 12) exchange the motherboard. 981 982 To compile this driver as a module, choose M here: the 983 module will be called apm. 984 985if APM 986 987config APM_IGNORE_USER_SUSPEND 988 bool "Ignore USER SUSPEND" 989 help 990 This option will ignore USER SUSPEND requests. On machines with a 991 compliant APM BIOS, you want to say N. However, on the NEC Versa M 992 series notebooks, it is necessary to say Y because of a BIOS bug. 993 994config APM_DO_ENABLE 995 bool "Enable PM at boot time" 996 ---help--- 997 Enable APM features at boot time. From page 36 of the APM BIOS 998 specification: "When disabled, the APM BIOS does not automatically 999 power manage devices, enter the Standby State, enter the Suspend 1000 State, or take power saving steps in response to CPU Idle calls."
1001 This driver will make CPU Idle calls when Linux is idle (unless this 1002 feature is turned off -- see "Do CPU IDLE calls", below). This 1003 should always save battery power, but more complicated APM features 1004 will be dependent on your BIOS implementation. You may need to turn 1005 this option off if your computer hangs at boot time when using APM 1006 support, or if it beeps continuously instead of suspending. Turn 1007 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1008 T400CDT. This is off by default since most machines do fine without 1009 this feature. 1010 1011config APM_CPU_IDLE 1012 bool "Make CPU Idle calls when idle" 1013 help 1014 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1015 On some machines, this can activate improved power savings, such as 1016 a slowed CPU clock rate, when the machine is idle. These idle calls 1017 are made after the idle loop has run for some length of time (e.g., 1018 333 mS). On some machines, this will cause a hang at boot time or 1019 whenever the CPU becomes idle. (On machines with more than one CPU, 1020 this option does nothing.) 1021 1022config APM_DISPLAY_BLANK 1023 bool "Enable console blanking using APM" 1024 help 1025 Enable console blanking using the APM. Some laptops can use this to 1026 turn off the LCD backlight when the screen blanker of the Linux 1027 virtual console blanks the screen. Note that this is only used by 1028 the virtual console screen blanker, and won't turn off the backlight 1029 when using the X Window system. This also doesn't have anything to 1030 do with your VESA-compliant power-saving monitor. Further, this 1031 option doesn't work for all laptops -- it might not turn off your 1032 backlight at all, or it might print a lot of errors to the console, 1033 especially if you are using gpm. 1034 1035config APM_ALLOW_INTS 1036 bool "Allow interrupts during APM BIOS calls" 1037 help 1038 Normally we disable external interrupts while we are making calls to 1039 the APM BIOS as a measure to lessen the effects of a badly behaving 1040 BIOS implementation. The BIOS should reenable interrupts if it 1041 needs to. Unfortunately, some BIOSes do not -- especially those in 1042 many of the newer IBM Thinkpads. If you experience hangs when you 1043 suspend, try setting this to Y. Otherwise, say N. 1044 1045config APM_REAL_MODE_POWER_OFF 1046 bool "Use real mode APM BIOS call to power off" 1047 help 1048 Use real mode APM BIOS calls to switch off the computer. This is 1049 a work-around for a number of buggy BIOSes. Switch this option on if 1050 your computer crashes instead of powering off properly. 1051 1052endif # APM 1053 1054source "arch/i386/kernel/cpu/cpufreq/Kconfig" 1055 1056endmenu 1057 1058menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)" 1059 1060config PCI 1061 bool "PCI support" if !X86_VISWS 1062 depends on !X86_VOYAGER 1063 default y if X86_VISWS 1064 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1065 help 1066 Find out whether you have a PCI motherboard. PCI is the name of a 1067 bus system, i.e. the way the CPU talks to the other stuff inside 1068 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1069 VESA. If you have PCI, say Y, otherwise N. 1070 1071 The PCI-HOWTO, available from 1072 <http://www.tldp.org/docs.html#howto>, contains valuable 1073 information about which PCI hardware does work under Linux and which 1074 doesn't. 1075 1076choice 1077 prompt "PCI access mode" 1078 depends on PCI && !X86_VISWS 1079 default PCI_GOANY 1080 ---help--- 1081 On PCI systems, the BIOS can be used to detect the PCI devices and 1082 determine their configuration. However, some old PCI motherboards 1083 have BIOS bugs and may crash if this is done. Also, some embedded 1084 PCI-based systems don't have any BIOS at all. Linux can also try to 1085 detect the PCI hardware directly without using the BIOS. 1086 1087 With this option, you can specify how Linux should detect the 1088 PCI devices. If you choose "BIOS", the BIOS will be used, 1089 if you choose "Direct", the BIOS won't be used, and if you 1090 choose "MMConfig", then PCI Express MMCONFIG will be used. 1091 If you choose "Any", the kernel will try MMCONFIG, then the 1092 direct access method and falls back to the BIOS if that doesn't 1093 work. If unsure, go with the default, which is "Any". 1094 1095config PCI_GOBIOS 1096 bool "BIOS" 1097 1098config PCI_GOMMCONFIG 1099 bool "MMConfig" 1100 1101config PCI_GODIRECT 1102 bool "Direct" 1103 1104config PCI_GOANY 1105 bool "Any" 1106 1107endchoice 1108 1109config PCI_BIOS 1110 bool 1111 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY) 1112 default y 1113 1114config PCI_DIRECT 1115 bool 1116 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS) 1117 default y 1118 1119config PCI_MMCONFIG 1120 bool 1121 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY) 1122 default y 1123 1124source "drivers/pci/pcie/Kconfig" 1125 1126source "drivers/pci/Kconfig" 1127 1128config ISA_DMA_API 1129 bool 1130 default y 1131 1132config ISA 1133 bool "ISA support" 1134 depends on !(X86_VOYAGER || X86_VISWS) 1135 help 1136 Find out whether you have ISA slots on your motherboard. ISA is the 1137 name of a bus system, i.e. the way the CPU talks to the other stuff 1138 inside your box. Other bus systems are PCI, EISA, MicroChannel 1139 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1140 newer boards don't support it. If you have ISA, say Y, otherwise N. 1141 1142config EISA 1143 bool "EISA support" 1144 depends on ISA 1145 ---help--- 1146 The Extended Industry Standard Architecture (EISA) bus was 1147 developed as an open alternative to the IBM MicroChannel bus. 1148 1149 The EISA bus provided some of the features of the IBM MicroChannel 1150 bus while maintaining backward compatibility with cards made for 1151 the older ISA bus. The EISA bus saw limited use between 1988 and 1152 1995 when it was made obsolete by the PCI bus. 1153 1154 Say Y here if you are building a kernel for an EISA-based machine. 1155 1156 Otherwise, say N. 1157 1158source "drivers/eisa/Kconfig" 1159 1160config MCA 1161 bool "MCA support" if !(X86_VISWS || X86_VOYAGER) 1162 default y if X86_VOYAGER 1163 help 1164 MicroChannel Architecture is found in some IBM PS/2 machines and 1165 laptops. It is a bus system similar to PCI or ISA. See 1166 <file:Documentation/mca.txt> (and especially the web page given 1167 there) before attempting to build an MCA bus kernel. 1168 1169source "drivers/mca/Kconfig" 1170 1171config SCx200 1172 tristate "NatSemi SCx200 support" 1173 depends on !X86_VOYAGER 1174 help 1175 This provides basic support for National Semiconductor's 1176 (now AMD's) Geode processors. The driver probes for the 1177 PCI-IDs of several on-chip devices, so its a good dependency 1178 for other scx200_* drivers. 1179 1180 If compiled as a module, the driver is named scx200. 1181 1182config SCx200HR_TIMER 1183 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 1184 depends on SCx200 && GENERIC_TIME 1185 default y 1186 help 1187 This driver provides a clocksource built upon the on-chip 1188 27MHz high-resolution timer. Its also a workaround for 1189 NSC Geode SC-1100's buggy TSC, which loses time when the 1190 processor goes idle (as is done by the scheduler). The 1191 other workaround is idle=poll boot option. 1192 1193config K8_NB 1194 def_bool y 1195 depends on AGP_AMD64 1196 1197source "drivers/pcmcia/Kconfig" 1198 1199source "drivers/pci/hotplug/Kconfig" 1200 1201endmenu 1202 1203menu "Executable file formats" 1204 1205source "fs/Kconfig.binfmt" 1206 1207endmenu 1208 1209source "net/Kconfig" 1210 1211source "drivers/Kconfig" 1212 1213source "fs/Kconfig" 1214 1215menu "Instrumentation Support" 1216 depends on EXPERIMENTAL 1217 1218source "arch/i386/oprofile/Kconfig" 1219 1220config KPROBES 1221 bool "Kprobes (EXPERIMENTAL)" 1222 depends on KALLSYMS && EXPERIMENTAL && MODULES 1223 help 1224 Kprobes allows you to trap at almost any kernel address and 1225 execute a callback function. register_kprobe() establishes 1226 a probepoint and specifies the callback. Kprobes is useful 1227 for kernel debugging, non-intrusive instrumentation and testing. 1228 If in doubt, say "N". 1229endmenu 1230 1231source "arch/i386/Kconfig.debug" 1232 1233source "security/Kconfig" 1234 1235source "crypto/Kconfig" 1236 1237source "lib/Kconfig" 1238 1239# 1240# Use the generic interrupt handling code in kernel/irq/: 1241# 1242config GENERIC_HARDIRQS 1243 bool 1244 default y 1245 1246config GENERIC_IRQ_PROBE 1247 bool 1248 default y 1249 1250config GENERIC_PENDING_IRQ 1251 bool 1252 depends on GENERIC_HARDIRQS && SMP 1253 default y 1254 1255config X86_SMP 1256 bool 1257 depends on SMP && !X86_VOYAGER 1258 default y 1259 1260config X86_HT 1261 bool 1262 depends on SMP && !(X86_VISWS || X86_VOYAGER) 1263 default y 1264 1265config X86_BIOS_REBOOT 1266 bool 1267 depends on !(X86_VISWS || X86_VOYAGER) 1268 default y 1269 1270config X86_TRAMPOLINE 1271 bool 1272 depends on X86_SMP || (X86_VOYAGER && SMP) 1273 default y 1274 1275config KTIME_SCALAR 1276 bool 1277 default y 1278

