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 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 MMU 18 bool 19 default y 20 21config SBUS 22 bool 23 24config UID16 25 bool 26 default y 27 28config GENERIC_ISA_DMA 29 bool 30 default y 31 32config GENERIC_IOMAP 33 bool 34 default y 35 36source "init/Kconfig" 37 38menu "Processor type and features" 39 40choice 41 prompt "Subarchitecture Type" 42 default X86_PC 43 44config X86_PC 45 bool "PC-compatible" 46 help 47 Choose this option if your computer is a standard PC or compatible. 48 49config X86_ELAN 50 bool "AMD Elan" 51 help 52 Select this for an AMD Elan processor. 53 54 Do not use this option for K6/Athlon/Opteron processors! 55 56 If unsure, choose "PC-compatible" instead. 57 58config X86_VOYAGER 59 bool "Voyager (NCR)" 60 help 61 Voyager is an MCA-based 32-way capable SMP architecture proprietary 62 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based. 63 64 *** WARNING *** 65 66 If you do not specifically know you have a Voyager based machine, 67 say N here, otherwise the kernel you build will not be bootable. 68 69config X86_NUMAQ 70 bool "NUMAQ (IBM/Sequent)" 71 select DISCONTIGMEM 72 select NUMA 73 help 74 This option is used for getting Linux to run on a (IBM/Sequent) NUMA 75 multiquad box. This changes the way that processors are bootstrapped, 76 and uses Clustered Logical APIC addressing mode instead of Flat Logical. 77 You will need a new lynxer.elf file to flash your firmware with - send 78 email to <Martin.Bligh@us.ibm.com>. 79 80config X86_SUMMIT 81 bool "Summit/EXA (IBM x440)" 82 depends on SMP 83 help 84 This option is needed for IBM systems that use the Summit/EXA chipset. 85 In particular, it is needed for the x440. 86 87 If you don't have one of these computers, you should say N here. 88 89config X86_BIGSMP 90 bool "Support for other sub-arch SMP systems with more than 8 CPUs" 91 depends on SMP 92 help 93 This option is needed for the systems that have more than 8 CPUs 94 and if the system is not of any sub-arch type above. 95 96 If you don't have such a system, you should say N here. 97 98config X86_VISWS 99 bool "SGI 320/540 (Visual Workstation)" 100 help 101 The SGI Visual Workstation series is an IA32-based workstation 102 based on SGI systems chips with some legacy PC hardware attached. 103 104 Say Y here to create a kernel to run on the SGI 320 or 540. 105 106 A kernel compiled for the Visual Workstation will not run on PCs 107 and vice versa. See <file:Documentation/sgi-visws.txt> for details. 108 109config X86_GENERICARCH 110 bool "Generic architecture (Summit, bigsmp, ES7000, default)" 111 depends on SMP 112 help 113 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures. 114 It is intended for a generic binary kernel. 115 116config X86_ES7000 117 bool "Support for Unisys ES7000 IA32 series" 118 depends on SMP 119 help 120 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 121 supposed to run on an IA32-based Unisys ES7000 system. 122 Only choose this option if you have such a system, otherwise you 123 should say N here. 124 125endchoice 126 127config ACPI_SRAT 128 bool 129 default y 130 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH) 131 132config X86_SUMMIT_NUMA 133 bool 134 default y 135 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH) 136 137config X86_CYCLONE_TIMER 138 bool 139 default y 140 depends on X86_SUMMIT || X86_GENERICARCH 141 142config ES7000_CLUSTERED_APIC 143 bool 144 default y 145 depends on SMP && X86_ES7000 && MPENTIUMIII 146 147if !X86_ELAN 148 149choice 150 prompt "Processor family" 151 default M686 152 153config M386 154 bool "386" 155 ---help--- 156 This is the processor type of your CPU. This information is used for 157 optimizing purposes. In order to compile a kernel that can run on 158 all x86 CPU types (albeit not optimally fast), you can specify 159 "386" here. 160 161 The kernel will not necessarily run on earlier architectures than 162 the one you have chosen, e.g. a Pentium optimized kernel will run on 163 a PPro, but not necessarily on a i486. 164 165 Here are the settings recommended for greatest speed: 166 - "386" for the AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI 167 486DLC/DLC2, UMC 486SX-S and NexGen Nx586. Only "386" kernels 168 will run on a 386 class machine. 169 - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or 170 SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S. 171 - "586" for generic Pentium CPUs lacking the TSC 172 (time stamp counter) register. 173 - "Pentium-Classic" for the Intel Pentium. 174 - "Pentium-MMX" for the Intel Pentium MMX. 175 - "Pentium-Pro" for the Intel Pentium Pro. 176 - "Pentium-II" for the Intel Pentium II or pre-Coppermine Celeron. 177 - "Pentium-III" for the Intel Pentium III or Coppermine Celeron. 178 - "Pentium-4" for the Intel Pentium 4 or P4-based Celeron. 179 - "K6" for the AMD K6, K6-II and K6-III (aka K6-3D). 180 - "Athlon" for the AMD K7 family (Athlon/Duron/Thunderbird). 181 - "Crusoe" for the Transmeta Crusoe series. 182 - "Efficeon" for the Transmeta Efficeon series. 183 - "Winchip-C6" for original IDT Winchip. 184 - "Winchip-2" for IDT Winchip 2. 185 - "Winchip-2A" for IDT Winchips with 3dNow! capabilities. 186 - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3. 187 - "VIA C3-2 for VIA C3-2 "Nehemiah" (model 9 and above). 188 189 If you don't know what to do, choose "386". 190 191config M486 192 bool "486" 193 help 194 Select this for a 486 series processor, either Intel or one of the 195 compatible processors from AMD, Cyrix, IBM, or Intel. Includes DX, 196 DX2, and DX4 variants; also SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or 197 U5S. 198 199config M586 200 bool "586/K5/5x86/6x86/6x86MX" 201 help 202 Select this for an 586 or 686 series processor such as the AMD K5, 203 the Cyrix 5x86, 6x86 and 6x86MX. This choice does not 204 assume the RDTSC (Read Time Stamp Counter) instruction. 205 206config M586TSC 207 bool "Pentium-Classic" 208 help 209 Select this for a Pentium Classic processor with the RDTSC (Read 210 Time Stamp Counter) instruction for benchmarking. 211 212config M586MMX 213 bool "Pentium-MMX" 214 help 215 Select this for a Pentium with the MMX graphics/multimedia 216 extended instructions. 217 218config M686 219 bool "Pentium-Pro" 220 help 221 Select this for Intel Pentium Pro chips. This enables the use of 222 Pentium Pro extended instructions, and disables the init-time guard 223 against the f00f bug found in earlier Pentiums. 224 225config MPENTIUMII 226 bool "Pentium-II/Celeron(pre-Coppermine)" 227 help 228 Select this for Intel chips based on the Pentium-II and 229 pre-Coppermine Celeron core. This option enables an unaligned 230 copy optimization, compiles the kernel with optimization flags 231 tailored for the chip, and applies any applicable Pentium Pro 232 optimizations. 233 234config MPENTIUMIII 235 bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon" 236 help 237 Select this for Intel chips based on the Pentium-III and 238 Celeron-Coppermine core. This option enables use of some 239 extended prefetch instructions in addition to the Pentium II 240 extensions. 241 242config MPENTIUMM 243 bool "Pentium M" 244 help 245 Select this for Intel Pentium M (not Pentium-4 M) 246 notebook chips. 247 248config MPENTIUM4 249 bool "Pentium-4/Celeron(P4-based)/Pentium-4 M/Xeon" 250 help 251 Select this for Intel Pentium 4 chips. This includes the 252 Pentium 4, P4-based Celeron and Xeon, and Pentium-4 M 253 (not Pentium M) chips. This option enables compile flags 254 optimized for the chip, uses the correct cache shift, and 255 applies any applicable Pentium III optimizations. 256 257config MK6 258 bool "K6/K6-II/K6-III" 259 help 260 Select this for an AMD K6-family processor. Enables use of 261 some extended instructions, and passes appropriate optimization 262 flags to GCC. 263 264config MK7 265 bool "Athlon/Duron/K7" 266 help 267 Select this for an AMD Athlon K7-family processor. Enables use of 268 some extended instructions, and passes appropriate optimization 269 flags to GCC. 270 271config MK8 272 bool "Opteron/Athlon64/Hammer/K8" 273 help 274 Select this for an AMD Opteron or Athlon64 Hammer-family processor. Enables 275 use of some extended instructions, and passes appropriate optimization 276 flags to GCC. 277 278config MCRUSOE 279 bool "Crusoe" 280 help 281 Select this for a Transmeta Crusoe processor. Treats the processor 282 like a 586 with TSC, and sets some GCC optimization flags (like a 283 Pentium Pro with no alignment requirements). 284 285config MEFFICEON 286 bool "Efficeon" 287 help 288 Select this for a Transmeta Efficeon processor. 289 290config MWINCHIPC6 291 bool "Winchip-C6" 292 help 293 Select this for an IDT Winchip C6 chip. Linux and GCC 294 treat this chip as a 586TSC with some extended instructions 295 and alignment requirements. 296 297config MWINCHIP2 298 bool "Winchip-2" 299 help 300 Select this for an IDT Winchip-2. Linux and GCC 301 treat this chip as a 586TSC with some extended instructions 302 and alignment requirements. 303 304config MWINCHIP3D 305 bool "Winchip-2A/Winchip-3" 306 help 307 Select this for an IDT Winchip-2A or 3. Linux and GCC 308 treat this chip as a 586TSC with some extended instructions 309 and alignment reqirements. Also enable out of order memory 310 stores for this CPU, which can increase performance of some 311 operations. 312 313config MCYRIXIII 314 bool "CyrixIII/VIA-C3" 315 help 316 Select this for a Cyrix III or C3 chip. Presently Linux and GCC 317 treat this chip as a generic 586. Whilst the CPU is 686 class, 318 it lacks the cmov extension which gcc assumes is present when 319 generating 686 code. 320 Note that Nehemiah (Model 9) and above will not boot with this 321 kernel due to them lacking the 3DNow! instructions used in earlier 322 incarnations of the CPU. 323 324config MVIAC3_2 325 bool "VIA C3-2 (Nehemiah)" 326 help 327 Select this for a VIA C3 "Nehemiah". Selecting this enables usage 328 of SSE and tells gcc to treat the CPU as a 686. 329 Note, this kernel will not boot on older (pre model 9) C3s. 330 331endchoice 332 333config X86_GENERIC 334 bool "Generic x86 support" 335 help 336 Instead of just including optimizations for the selected 337 x86 variant (e.g. PII, Crusoe or Athlon), include some more 338 generic optimizations as well. This will make the kernel 339 perform better on x86 CPUs other than that selected. 340 341 This is really intended for distributors who need more 342 generic optimizations. 343 344endif 345 346# 347# Define implied options from the CPU selection here 348# 349config X86_CMPXCHG 350 bool 351 depends on !M386 352 default y 353 354config X86_XADD 355 bool 356 depends on !M386 357 default y 358 359config X86_L1_CACHE_SHIFT 360 int 361 default "7" if MPENTIUM4 || X86_GENERIC 362 default "4" if X86_ELAN || M486 || M386 363 default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 364 default "6" if MK7 || MK8 || MPENTIUMM 365 366config RWSEM_GENERIC_SPINLOCK 367 bool 368 depends on M386 369 default y 370 371config RWSEM_XCHGADD_ALGORITHM 372 bool 373 depends on !M386 374 default y 375 376config GENERIC_CALIBRATE_DELAY 377 bool 378 default y 379 380config X86_PPRO_FENCE 381 bool 382 depends on M686 || M586MMX || M586TSC || M586 || M486 || M386 383 default y 384 385config X86_F00F_BUG 386 bool 387 depends on M586MMX || M586TSC || M586 || M486 || M386 388 default y 389 390config X86_WP_WORKS_OK 391 bool 392 depends on !M386 393 default y 394 395config X86_INVLPG 396 bool 397 depends on !M386 398 default y 399 400config X86_BSWAP 401 bool 402 depends on !M386 403 default y 404 405config X86_POPAD_OK 406 bool 407 depends on !M386 408 default y 409 410config X86_ALIGNMENT_16 411 bool 412 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || X86_ELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 413 default y 414 415config X86_GOOD_APIC 416 bool 417 depends on MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8 || MEFFICEON 418 default y 419 420config X86_INTEL_USERCOPY 421 bool 422 depends on MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7 || MEFFICEON 423 default y 424 425config X86_USE_PPRO_CHECKSUM 426 bool 427 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2 || MEFFICEON 428 default y 429 430config X86_USE_3DNOW 431 bool 432 depends on MCYRIXIII || MK7 433 default y 434 435config X86_OOSTORE 436 bool 437 depends on (MWINCHIP3D || MWINCHIP2 || MWINCHIPC6) && MTRR 438 default y 439 440config HPET_TIMER 441 bool "HPET Timer Support" 442 help 443 This enables the use of the HPET for the kernel's internal timer. 444 HPET is the next generation timer replacing legacy 8254s. 445 You can safely choose Y here. However, HPET will only be 446 activated if the platform and the BIOS support this feature. 447 Otherwise the 8254 will be used for timing services. 448 449 Choose N to continue using the legacy 8254 timer. 450 451config HPET_EMULATE_RTC 452 bool "Provide RTC interrupt" 453 depends on HPET_TIMER && RTC=y 454 455config SMP 456 bool "Symmetric multi-processing support" 457 ---help--- 458 This enables support for systems with more than one CPU. If you have 459 a system with only one CPU, like most personal computers, say N. If 460 you have a system with more than one CPU, say Y. 461 462 If you say N here, the kernel will run on single and multiprocessor 463 machines, but will use only one CPU of a multiprocessor machine. If 464 you say Y here, the kernel will run on many, but not all, 465 singleprocessor machines. On a singleprocessor machine, the kernel 466 will run faster if you say N here. 467 468 Note that if you say Y here and choose architecture "586" or 469 "Pentium" under "Processor family", the kernel will not work on 486 470 architectures. Similarly, multiprocessor kernels for the "PPro" 471 architecture may not work on all Pentium based boards. 472 473 People using multiprocessor machines who say Y here should also say 474 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 475 Management" code will be disabled if you say Y here. 476 477 See also the <file:Documentation/smp.txt>, 478 <file:Documentation/i386/IO-APIC.txt>, 479 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 480 <http://www.tldp.org/docs.html#howto>. 481 482 If you don't know what to do here, say N. 483 484config NR_CPUS 485 int "Maximum number of CPUs (2-255)" 486 range 2 255 487 depends on SMP 488 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000 489 default "8" 490 help 491 This allows you to specify the maximum number of CPUs which this 492 kernel will support. The maximum supported value is 255 and the 493 minimum value which makes sense is 2. 494 495 This is purely to save memory - each supported CPU adds 496 approximately eight kilobytes to the kernel image. 497 498config SCHED_SMT 499 bool "SMT (Hyperthreading) scheduler support" 500 depends on SMP 501 default off 502 help 503 SMT scheduler support improves the CPU scheduler's decision making 504 when dealing with Intel Pentium 4 chips with HyperThreading at a 505 cost of slightly increased overhead in some places. If unsure say 506 N here. 507 508config PREEMPT 509 bool "Preemptible Kernel" 510 help 511 This option reduces the latency of the kernel when reacting to 512 real-time or interactive events by allowing a low priority process to 513 be preempted even if it is in kernel mode executing a system call. 514 This allows applications to run more reliably even when the system is 515 under load. 516 517 Say Y here if you are building a kernel for a desktop, embedded 518 or real-time system. Say N if you are unsure. 519 520config PREEMPT_BKL 521 bool "Preempt The Big Kernel Lock" 522 depends on PREEMPT 523 default y 524 help 525 This option reduces the latency of the kernel by making the 526 big kernel lock preemptible. 527 528 Say Y here if you are building a kernel for a desktop system. 529 Say N if you are unsure. 530 531config X86_UP_APIC 532 bool "Local APIC support on uniprocessors" if !SMP 533 depends on !(X86_VISWS || X86_VOYAGER) 534 ---help--- 535 A local APIC (Advanced Programmable Interrupt Controller) is an 536 integrated interrupt controller in the CPU. If you have a single-CPU 537 system which has a processor with a local APIC, you can say Y here to 538 enable and use it. If you say Y here even though your machine doesn't 539 have a local APIC, then the kernel will still run with no slowdown at 540 all. The local APIC supports CPU-generated self-interrupts (timer, 541 performance counters), and the NMI watchdog which detects hard 542 lockups. 543 544 If you have a system with several CPUs, you do not need to say Y 545 here: the local APIC will be used automatically. 546 547config X86_UP_IOAPIC 548 bool "IO-APIC support on uniprocessors" 549 depends on !SMP && X86_UP_APIC 550 help 551 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 552 SMP-capable replacement for PC-style interrupt controllers. Most 553 SMP systems and a small number of uniprocessor systems have one. 554 If you have a single-CPU system with an IO-APIC, you can say Y here 555 to use it. If you say Y here even though your machine doesn't have 556 an IO-APIC, then the kernel will still run with no slowdown at all. 557 558 If you have a system with several CPUs, you do not need to say Y 559 here: the IO-APIC will be used automatically. 560 561config X86_LOCAL_APIC 562 bool 563 depends on !SMP && X86_UP_APIC 564 default y 565 566config X86_IO_APIC 567 bool 568 depends on !SMP && X86_UP_IOAPIC 569 default y 570 571config X86_TSC 572 bool 573 depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MEFFICEON || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2) && !X86_NUMAQ 574 default y 575 576config X86_MCE 577 bool "Machine Check Exception" 578 depends on !X86_VOYAGER 579 ---help--- 580 Machine Check Exception support allows the processor to notify the 581 kernel if it detects a problem (e.g. overheating, component failure). 582 The action the kernel takes depends on the severity of the problem, 583 ranging from a warning message on the console, to halting the machine. 584 Your processor must be a Pentium or newer to support this - check the 585 flags in /proc/cpuinfo for mce. Note that some older Pentium systems 586 have a design flaw which leads to false MCE events - hence MCE is 587 disabled on all P5 processors, unless explicitly enabled with "mce" 588 as a boot argument. Similarly, if MCE is built in and creates a 589 problem on some new non-standard machine, you can boot with "nomce" 590 to disable it. MCE support simply ignores non-MCE processors like 591 the 386 and 486, so nearly everyone can say Y here. 592 593config X86_MCE_NONFATAL 594 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" 595 depends on X86_MCE 596 help 597 Enabling this feature starts a timer that triggers every 5 seconds which 598 will look at the machine check registers to see if anything happened. 599 Non-fatal problems automatically get corrected (but still logged). 600 Disable this if you don't want to see these messages. 601 Seeing the messages this option prints out may be indicative of dying hardware, 602 or out-of-spec (ie, overclocked) hardware. 603 This option only does something on certain CPUs. 604 (AMD Athlon/Duron and Intel Pentium 4) 605 606config X86_MCE_P4THERMAL 607 bool "check for P4 thermal throttling interrupt." 608 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS 609 help 610 Enabling this feature will cause a message to be printed when the P4 611 enters thermal throttling. 612 613config TOSHIBA 614 tristate "Toshiba Laptop support" 615 ---help--- 616 This adds a driver to safely access the System Management Mode of 617 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 618 not work on models with a Phoenix BIOS. The System Management Mode 619 is used to set the BIOS and power saving options on Toshiba portables. 620 621 For information on utilities to make use of this driver see the 622 Toshiba Linux utilities web site at: 623 <http://www.buzzard.org.uk/toshiba/>. 624 625 Say Y if you intend to run this kernel on a Toshiba portable. 626 Say N otherwise. 627 628config I8K 629 tristate "Dell laptop support" 630 ---help--- 631 This adds a driver to safely access the System Management Mode 632 of the CPU on the Dell Inspiron 8000. The System Management Mode 633 is used to read cpu temperature and cooling fan status and to 634 control the fans on the I8K portables. 635 636 This driver has been tested only on the Inspiron 8000 but it may 637 also work with other Dell laptops. You can force loading on other 638 models by passing the parameter `force=1' to the module. Use at 639 your own risk. 640 641 For information on utilities to make use of this driver see the 642 I8K Linux utilities web site at: 643 <http://people.debian.org/~dz/i8k/> 644 645 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 646 Say N otherwise. 647 648config MICROCODE 649 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support" 650 ---help--- 651 If you say Y here and also to "/dev file system support" in the 652 'File systems' section, you will be able to update the microcode on 653 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II, 654 Pentium III, Pentium 4, Xeon etc. You will obviously need the 655 actual microcode binary data itself which is not shipped with the 656 Linux kernel. 657 658 For latest news and information on obtaining all the required 659 ingredients for this driver, check: 660 <http://www.urbanmyth.org/microcode/>. 661 662 To compile this driver as a module, choose M here: the 663 module will be called microcode. 664 665config X86_MSR 666 tristate "/dev/cpu/*/msr - Model-specific register support" 667 help 668 This device gives privileged processes access to the x86 669 Model-Specific Registers (MSRs). It is a character device with 670 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 671 MSR accesses are directed to a specific CPU on multi-processor 672 systems. 673 674config X86_CPUID 675 tristate "/dev/cpu/*/cpuid - CPU information support" 676 help 677 This device gives processes access to the x86 CPUID instruction to 678 be executed on a specific processor. It is a character device 679 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 680 /dev/cpu/31/cpuid. 681 682source "drivers/firmware/Kconfig" 683 684choice 685 prompt "High Memory Support" 686 default NOHIGHMEM 687 688config NOHIGHMEM 689 bool "off" 690 ---help--- 691 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 692 However, the address space of 32-bit x86 processors is only 4 693 Gigabytes large. That means that, if you have a large amount of 694 physical memory, not all of it can be "permanently mapped" by the 695 kernel. The physical memory that's not permanently mapped is called 696 "high memory". 697 698 If you are compiling a kernel which will never run on a machine with 699 more than 1 Gigabyte total physical RAM, answer "off" here (default 700 choice and suitable for most users). This will result in a "3GB/1GB" 701 split: 3GB are mapped so that each process sees a 3GB virtual memory 702 space and the remaining part of the 4GB virtual memory space is used 703 by the kernel to permanently map as much physical memory as 704 possible. 705 706 If the machine has between 1 and 4 Gigabytes physical RAM, then 707 answer "4GB" here. 708 709 If more than 4 Gigabytes is used then answer "64GB" here. This 710 selection turns Intel PAE (Physical Address Extension) mode on. 711 PAE implements 3-level paging on IA32 processors. PAE is fully 712 supported by Linux, PAE mode is implemented on all recent Intel 713 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 714 then the kernel will not boot on CPUs that don't support PAE! 715 716 The actual amount of total physical memory will either be 717 auto detected or can be forced by using a kernel command line option 718 such as "mem=256M". (Try "man bootparam" or see the documentation of 719 your boot loader (lilo or loadlin) about how to pass options to the 720 kernel at boot time.) 721 722 If unsure, say "off". 723 724config HIGHMEM4G 725 bool "4GB" 726 help 727 Select this if you have a 32-bit processor and between 1 and 4 728 gigabytes of physical RAM. 729 730config HIGHMEM64G 731 bool "64GB" 732 help 733 Select this if you have a 32-bit processor and more than 4 734 gigabytes of physical RAM. 735 736endchoice 737 738config HIGHMEM 739 bool 740 depends on HIGHMEM64G || HIGHMEM4G 741 default y 742 743config X86_PAE 744 bool 745 depends on HIGHMEM64G 746 default y 747 748# Common NUMA Features 749config NUMA 750 bool "Numa Memory Allocation and Scheduler Support" 751 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI)) 752 default n if X86_PC 753 default y if (X86_NUMAQ || X86_SUMMIT) 754 755# Need comments to help the hapless user trying to turn on NUMA support 756comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support" 757 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP) 758 759comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 760 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI) 761 762config DISCONTIGMEM 763 bool 764 depends on NUMA 765 default y 766 767config HAVE_ARCH_BOOTMEM_NODE 768 bool 769 depends on NUMA 770 default y 771 772config HIGHPTE 773 bool "Allocate 3rd-level pagetables from highmem" 774 depends on HIGHMEM4G || HIGHMEM64G 775 help 776 The VM uses one page table entry for each page of physical memory. 777 For systems with a lot of RAM, this can be wasteful of precious 778 low memory. Setting this option will put user-space page table 779 entries in high memory. 780 781config MATH_EMULATION 782 bool "Math emulation" 783 ---help--- 784 Linux can emulate a math coprocessor (used for floating point 785 operations) if you don't have one. 486DX and Pentium processors have 786 a math coprocessor built in, 486SX and 386 do not, unless you added 787 a 487DX or 387, respectively. (The messages during boot time can 788 give you some hints here ["man dmesg"].) Everyone needs either a 789 coprocessor or this emulation. 790 791 If you don't have a math coprocessor, you need to say Y here; if you 792 say Y here even though you have a coprocessor, the coprocessor will 793 be used nevertheless. (This behavior can be changed with the kernel 794 command line option "no387", which comes handy if your coprocessor 795 is broken. Try "man bootparam" or see the documentation of your boot 796 loader (lilo or loadlin) about how to pass options to the kernel at 797 boot time.) This means that it is a good idea to say Y here if you 798 intend to use this kernel on different machines. 799 800 More information about the internals of the Linux math coprocessor 801 emulation can be found in <file:arch/i386/math-emu/README>. 802 803 If you are not sure, say Y; apart from resulting in a 66 KB bigger 804 kernel, it won't hurt. 805 806config MTRR 807 bool "MTRR (Memory Type Range Register) support" 808 ---help--- 809 On Intel P6 family processors (Pentium Pro, Pentium II and later) 810 the Memory Type Range Registers (MTRRs) may be used to control 811 processor access to memory ranges. This is most useful if you have 812 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 813 allows bus write transfers to be combined into a larger transfer 814 before bursting over the PCI/AGP bus. This can increase performance 815 of image write operations 2.5 times or more. Saying Y here creates a 816 /proc/mtrr file which may be used to manipulate your processor's 817 MTRRs. Typically the X server should use this. 818 819 This code has a reasonably generic interface so that similar 820 control registers on other processors can be easily supported 821 as well: 822 823 The Cyrix 6x86, 6x86MX and M II processors have Address Range 824 Registers (ARRs) which provide a similar functionality to MTRRs. For 825 these, the ARRs are used to emulate the MTRRs. 826 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 827 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 828 write-combining. All of these processors are supported by this code 829 and it makes sense to say Y here if you have one of them. 830 831 Saying Y here also fixes a problem with buggy SMP BIOSes which only 832 set the MTRRs for the boot CPU and not for the secondary CPUs. This 833 can lead to all sorts of problems, so it's good to say Y here. 834 835 You can safely say Y even if your machine doesn't have MTRRs, you'll 836 just add about 9 KB to your kernel. 837 838 See <file:Documentation/mtrr.txt> for more information. 839 840config EFI 841 bool "Boot from EFI support (EXPERIMENTAL)" 842 depends on ACPI 843 default n 844 ---help--- 845 This enables the the kernel to boot on EFI platforms using 846 system configuration information passed to it from the firmware. 847 This also enables the kernel to use any EFI runtime services that are 848 available (such as the EFI variable services). 849 850 This option is only useful on systems that have EFI firmware 851 and will result in a kernel image that is ~8k larger. In addition, 852 you must use the latest ELILO loader available at 853 <http://elilo.sourceforge.net> in order to take advantage of 854 kernel initialization using EFI information (neither GRUB nor LILO know 855 anything about EFI). However, even with this option, the resultant 856 kernel should continue to boot on existing non-EFI platforms. 857 858config IRQBALANCE 859 bool "Enable kernel irq balancing" 860 depends on SMP && X86_IO_APIC 861 default y 862 help 863 The default yes will allow the kernel to do irq load balancing. 864 Saying no will keep the kernel from doing irq load balancing. 865 866config HAVE_DEC_LOCK 867 bool 868 depends on (SMP || PREEMPT) && X86_CMPXCHG 869 default y 870 871# turning this on wastes a bunch of space. 872# Summit needs it only when NUMA is on 873config BOOT_IOREMAP 874 bool 875 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI)) 876 default y 877 878config REGPARM 879 bool "Use register arguments (EXPERIMENTAL)" 880 depends on EXPERIMENTAL 881 default n 882 help 883 Compile the kernel with -mregparm=3. This uses a different ABI 884 and passes the first three arguments of a function call in registers. 885 This will probably break binary only modules. 886 887 This feature is only enabled for gcc-3.0 and later - earlier compilers 888 generate incorrect output with certain kernel constructs when 889 -mregparm=3 is used. 890 891endmenu 892 893 894menu "Power management options (ACPI, APM)" 895 depends on !X86_VOYAGER 896 897source kernel/power/Kconfig 898 899source "drivers/acpi/Kconfig" 900 901menu "APM (Advanced Power Management) BIOS Support" 902depends on PM && !X86_VISWS 903 904config APM 905 tristate "APM (Advanced Power Management) BIOS support" 906 depends on PM 907 ---help--- 908 APM is a BIOS specification for saving power using several different 909 techniques. This is mostly useful for battery powered laptops with 910 APM compliant BIOSes. If you say Y here, the system time will be 911 reset after a RESUME operation, the /proc/apm device will provide 912 battery status information, and user-space programs will receive 913 notification of APM "events" (e.g. battery status change). 914 915 If you select "Y" here, you can disable actual use of the APM 916 BIOS by passing the "apm=off" option to the kernel at boot time. 917 918 Note that the APM support is almost completely disabled for 919 machines with more than one CPU. 920 921 In order to use APM, you will need supporting software. For location 922 and more information, read <file:Documentation/pm.txt> and the 923 Battery Powered Linux mini-HOWTO, available from 924 <http://www.tldp.org/docs.html#howto>. 925 926 This driver does not spin down disk drives (see the hdparm(8) 927 manpage ("man 8 hdparm") for that), and it doesn't turn off 928 VESA-compliant "green" monitors. 929 930 This driver does not support the TI 4000M TravelMate and the ACER 931 486/DX4/75 because they don't have compliant BIOSes. Many "green" 932 desktop machines also don't have compliant BIOSes, and this driver 933 may cause those machines to panic during the boot phase. 934 935 Generally, if you don't have a battery in your machine, there isn't 936 much point in using this driver and you should say N. If you get 937 random kernel OOPSes or reboots that don't seem to be related to 938 anything, try disabling/enabling this option (or disabling/enabling 939 APM in your BIOS). 940 941 Some other things you should try when experiencing seemingly random, 942 "weird" problems: 943 944 1) make sure that you have enough swap space and that it is 945 enabled. 946 2) pass the "no-hlt" option to the kernel 947 3) switch on floating point emulation in the kernel and pass 948 the "no387" option to the kernel 949 4) pass the "floppy=nodma" option to the kernel 950 5) pass the "mem=4M" option to the kernel (thereby disabling 951 all but the first 4 MB of RAM) 952 6) make sure that the CPU is not over clocked. 953 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 954 8) disable the cache from your BIOS settings 955 9) install a fan for the video card or exchange video RAM 956 10) install a better fan for the CPU 957 11) exchange RAM chips 958 12) exchange the motherboard. 959 960 To compile this driver as a module, choose M here: the 961 module will be called apm. 962 963config APM_IGNORE_USER_SUSPEND 964 bool "Ignore USER SUSPEND" 965 depends on APM 966 help 967 This option will ignore USER SUSPEND requests. On machines with a 968 compliant APM BIOS, you want to say N. However, on the NEC Versa M 969 series notebooks, it is necessary to say Y because of a BIOS bug. 970 971config APM_DO_ENABLE 972 bool "Enable PM at boot time" 973 depends on APM 974 ---help--- 975 Enable APM features at boot time. From page 36 of the APM BIOS 976 specification: "When disabled, the APM BIOS does not automatically 977 power manage devices, enter the Standby State, enter the Suspend 978 State, or take power saving steps in response to CPU Idle calls." 979 This driver will make CPU Idle calls when Linux is idle (unless this 980 feature is turned off -- see "Do CPU IDLE calls", below). This 981 should always save battery power, but more complicated APM features 982 will be dependent on your BIOS implementation. You may need to turn 983 this option off if your computer hangs at boot time when using APM 984 support, or if it beeps continuously instead of suspending. Turn 985 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 986 T400CDT. This is off by default since most machines do fine without 987 this feature. 988 989config APM_CPU_IDLE 990 bool "Make CPU Idle calls when idle" 991 depends on APM 992 help 993 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 994 On some machines, this can activate improved power savings, such as 995 a slowed CPU clock rate, when the machine is idle. These idle calls 996 are made after the idle loop has run for some length of time (e.g., 997 333 mS). On some machines, this will cause a hang at boot time or 998 whenever the CPU becomes idle. (On machines with more than one CPU, 999 this option does nothing.) 1000
1001config APM_DISPLAY_BLANK 1002 bool "Enable console blanking using APM" 1003 depends on APM 1004 help 1005 Enable console blanking using the APM. Some laptops can use this to 1006 turn off the LCD backlight when the screen blanker of the Linux 1007 virtual console blanks the screen. Note that this is only used by 1008 the virtual console screen blanker, and won't turn off the backlight 1009 when using the X Window system. This also doesn't have anything to 1010 do with your VESA-compliant power-saving monitor. Further, this 1011 option doesn't work for all laptops -- it might not turn off your 1012 backlight at all, or it might print a lot of errors to the console, 1013 especially if you are using gpm. 1014 1015config APM_RTC_IS_GMT 1016 bool "RTC stores time in GMT" 1017 depends on APM 1018 help 1019 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock) 1020 stores the time in GMT (Greenwich Mean Time). Say N if your RTC 1021 stores localtime. 1022 1023 It is in fact recommended to store GMT in your RTC, because then you 1024 don't have to worry about daylight savings time changes. The only 1025 reason not to use GMT in your RTC is if you also run a broken OS 1026 that doesn't understand GMT. 1027 1028config APM_ALLOW_INTS 1029 bool "Allow interrupts during APM BIOS calls" 1030 depends on APM 1031 help 1032 Normally we disable external interrupts while we are making calls to 1033 the APM BIOS as a measure to lessen the effects of a badly behaving 1034 BIOS implementation. The BIOS should reenable interrupts if it 1035 needs to. Unfortunately, some BIOSes do not -- especially those in 1036 many of the newer IBM Thinkpads. If you experience hangs when you 1037 suspend, try setting this to Y. Otherwise, say N. 1038 1039config APM_REAL_MODE_POWER_OFF 1040 bool "Use real mode APM BIOS call to power off" 1041 depends on APM 1042 help 1043 Use real mode APM BIOS calls to switch off the computer. This is 1044 a work-around for a number of buggy BIOSes. Switch this option on if 1045 your computer crashes instead of powering off properly. 1046 1047endmenu 1048 1049source "arch/i386/kernel/cpu/cpufreq/Kconfig" 1050 1051endmenu 1052 1053menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)" 1054 1055config X86_VISWS_APIC 1056 bool 1057 depends on X86_VISWS 1058 default y 1059 1060config X86_LOCAL_APIC 1061 bool 1062 depends on (X86_VISWS || SMP) && !X86_VOYAGER 1063 default y 1064 1065config X86_IO_APIC 1066 bool 1067 depends on SMP && !(X86_VISWS || X86_VOYAGER) 1068 default y 1069 1070config PCI 1071 bool "PCI support" if !X86_VISWS 1072 depends on !X86_VOYAGER 1073 default y if X86_VISWS 1074 help 1075 Find out whether you have a PCI motherboard. PCI is the name of a 1076 bus system, i.e. the way the CPU talks to the other stuff inside 1077 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1078 VESA. If you have PCI, say Y, otherwise N. 1079 1080 The PCI-HOWTO, available from 1081 <http://www.tldp.org/docs.html#howto>, contains valuable 1082 information about which PCI hardware does work under Linux and which 1083 doesn't. 1084 1085choice 1086 prompt "PCI access mode" 1087 depends on PCI && !X86_VISWS 1088 default PCI_GOANY 1089 ---help--- 1090 On PCI systems, the BIOS can be used to detect the PCI devices and 1091 determine their configuration. However, some old PCI motherboards 1092 have BIOS bugs and may crash if this is done. Also, some embedded 1093 PCI-based systems don't have any BIOS at all. Linux can also try to 1094 detect the PCI hardware directly without using the BIOS. 1095 1096 With this option, you can specify how Linux should detect the 1097 PCI devices. If you choose "BIOS", the BIOS will be used, 1098 if you choose "Direct", the BIOS won't be used, and if you 1099 choose "MMConfig", then PCI Express MMCONFIG will be used. 1100 If you choose "Any", the kernel will try MMCONFIG, then the 1101 direct access method and falls back to the BIOS if that doesn't 1102 work. If unsure, go with the default, which is "Any". 1103 1104config PCI_GOBIOS 1105 bool "BIOS" 1106 1107config PCI_GOMMCONFIG 1108 bool "MMConfig" 1109 1110config PCI_GODIRECT 1111 bool "Direct" 1112 1113config PCI_GOANY 1114 bool "Any" 1115 1116endchoice 1117 1118config PCI_BIOS 1119 bool 1120 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY) 1121 default y 1122 1123config PCI_DIRECT 1124 bool 1125 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS) 1126 default y 1127 1128config PCI_MMCONFIG 1129 bool 1130 depends on PCI && (PCI_GOMMCONFIG || (PCI_GOANY && ACPI)) 1131 select ACPI_BOOT 1132 default y 1133 1134source "drivers/pci/pcie/Kconfig" 1135 1136source "drivers/pci/Kconfig" 1137 1138config ISA 1139 bool "ISA support" 1140 depends on !(X86_VOYAGER || X86_VISWS) 1141 help 1142 Find out whether you have ISA slots on your motherboard. ISA is the 1143 name of a bus system, i.e. the way the CPU talks to the other stuff 1144 inside your box. Other bus systems are PCI, EISA, MicroChannel 1145 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1146 newer boards don't support it. If you have ISA, say Y, otherwise N. 1147 1148config EISA 1149 bool "EISA support" 1150 depends on ISA 1151 ---help--- 1152 The Extended Industry Standard Architecture (EISA) bus was 1153 developed as an open alternative to the IBM MicroChannel bus. 1154 1155 The EISA bus provided some of the features of the IBM MicroChannel 1156 bus while maintaining backward compatibility with cards made for 1157 the older ISA bus. The EISA bus saw limited use between 1988 and 1158 1995 when it was made obsolete by the PCI bus. 1159 1160 Say Y here if you are building a kernel for an EISA-based machine. 1161 1162 Otherwise, say N. 1163 1164source "drivers/eisa/Kconfig" 1165 1166config MCA 1167 bool "MCA support" 1168 depends on !(X86_VISWS || X86_VOYAGER) 1169 help 1170 MicroChannel Architecture is found in some IBM PS/2 machines and 1171 laptops. It is a bus system similar to PCI or ISA. See 1172 <file:Documentation/mca.txt> (and especially the web page given 1173 there) before attempting to build an MCA bus kernel. 1174 1175config MCA 1176 depends on X86_VOYAGER 1177 default y if X86_VOYAGER 1178 1179source "drivers/mca/Kconfig" 1180 1181config SCx200 1182 tristate "NatSemi SCx200 support" 1183 depends on !X86_VOYAGER 1184 help 1185 This provides basic support for the National Semiconductor SCx200 1186 processor. Right now this is just a driver for the GPIO pins. 1187 1188 If you don't know what to do here, say N. 1189 1190 This support is also available as a module. If compiled as a 1191 module, it will be called scx200. 1192 1193source "drivers/pcmcia/Kconfig" 1194 1195source "drivers/pci/hotplug/Kconfig" 1196 1197endmenu 1198 1199menu "Executable file formats" 1200 1201source "fs/Kconfig.binfmt" 1202 1203endmenu 1204 1205source "drivers/Kconfig" 1206 1207source "fs/Kconfig" 1208 1209source "arch/i386/oprofile/Kconfig" 1210 1211source "arch/i386/Kconfig.debug" 1212 1213source "security/Kconfig" 1214 1215source "crypto/Kconfig" 1216 1217source "lib/Kconfig" 1218 1219# 1220# Use the generic interrupt handling code in kernel/irq/: 1221# 1222config GENERIC_HARDIRQS 1223 bool 1224 default y 1225 1226config GENERIC_IRQ_PROBE 1227 bool 1228 default y 1229 1230config X86_SMP 1231 bool 1232 depends on SMP && !X86_VOYAGER 1233 default y 1234 1235config X86_HT 1236 bool 1237 depends on SMP && !(X86_VISWS || X86_VOYAGER) 1238 default y 1239 1240config X86_BIOS_REBOOT 1241 bool 1242 depends on !(X86_VISWS || X86_VOYAGER) 1243 default y 1244 1245config X86_TRAMPOLINE 1246 bool 1247 depends on X86_SMP || (X86_VOYAGER && SMP) 1248 default y 1249 1250config PC 1251 bool 1252 depends on X86 && !EMBEDDED 1253 default y 1254