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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#
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 - "MediaGX/Geode" for Cyrix MediaGX aka Geode.
187 - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3.
188 - "VIA C3-2 for VIA C3-2 "Nehemiah" (model 9 and above).
189
190 If you don't know what to do, choose "386".
191
192config M486
193 bool "486"
194 help
195 Select this for a 486 series processor, either Intel or one of the
196 compatible processors from AMD, Cyrix, IBM, or Intel. Includes DX,
197 DX2, and DX4 variants; also SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or
198 U5S.
199
200config M586
201 bool "586/K5/5x86/6x86/6x86MX"
202 help
203 Select this for an 586 or 686 series processor such as the AMD K5,
204 the Cyrix 5x86, 6x86 and 6x86MX. This choice does not
205 assume the RDTSC (Read Time Stamp Counter) instruction.
206
207config M586TSC
208 bool "Pentium-Classic"
209 help
210 Select this for a Pentium Classic processor with the RDTSC (Read
211 Time Stamp Counter) instruction for benchmarking.
212
213config M586MMX
214 bool "Pentium-MMX"
215 help
216 Select this for a Pentium with the MMX graphics/multimedia
217 extended instructions.
218
219config M686
220 bool "Pentium-Pro"
221 help
222 Select this for Intel Pentium Pro chips. This enables the use of
223 Pentium Pro extended instructions, and disables the init-time guard
224 against the f00f bug found in earlier Pentiums.
225
226config MPENTIUMII
227 bool "Pentium-II/Celeron(pre-Coppermine)"
228 help
229 Select this for Intel chips based on the Pentium-II and
230 pre-Coppermine Celeron core. This option enables an unaligned
231 copy optimization, compiles the kernel with optimization flags
232 tailored for the chip, and applies any applicable Pentium Pro
233 optimizations.
234
235config MPENTIUMIII
236 bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon"
237 help
238 Select this for Intel chips based on the Pentium-III and
239 Celeron-Coppermine core. This option enables use of some
240 extended prefetch instructions in addition to the Pentium II
241 extensions.
242
243config MPENTIUMM
244 bool "Pentium M"
245 help
246 Select this for Intel Pentium M (not Pentium-4 M)
247 notebook chips.
248
249config MPENTIUM4
250 bool "Pentium-4/Celeron(P4-based)/Pentium-4 M/Xeon"
251 help
252 Select this for Intel Pentium 4 chips. This includes the
253 Pentium 4, P4-based Celeron and Xeon, and Pentium-4 M
254 (not Pentium M) chips. This option enables compile flags
255 optimized for the chip, uses the correct cache shift, and
256 applies any applicable Pentium III optimizations.
257
258config MK6
259 bool "K6/K6-II/K6-III"
260 help
261 Select this for an AMD K6-family processor. Enables use of
262 some extended instructions, and passes appropriate optimization
263 flags to GCC.
264
265config MK7
266 bool "Athlon/Duron/K7"
267 help
268 Select this for an AMD Athlon K7-family processor. Enables use of
269 some extended instructions, and passes appropriate optimization
270 flags to GCC.
271
272config MK8
273 bool "Opteron/Athlon64/Hammer/K8"
274 help
275 Select this for an AMD Opteron or Athlon64 Hammer-family processor. Enables
276 use of some extended instructions, and passes appropriate optimization
277 flags to GCC.
278
279config MCRUSOE
280 bool "Crusoe"
281 help
282 Select this for a Transmeta Crusoe processor. Treats the processor
283 like a 586 with TSC, and sets some GCC optimization flags (like a
284 Pentium Pro with no alignment requirements).
285
286config MEFFICEON
287 bool "Efficeon"
288 help
289 Select this for a Transmeta Efficeon processor.
290
291config MWINCHIPC6
292 bool "Winchip-C6"
293 help
294 Select this for an IDT Winchip C6 chip. Linux and GCC
295 treat this chip as a 586TSC with some extended instructions
296 and alignment requirements.
297
298config MWINCHIP2
299 bool "Winchip-2"
300 help
301 Select this for an IDT Winchip-2. Linux and GCC
302 treat this chip as a 586TSC with some extended instructions
303 and alignment requirements.
304
305config MWINCHIP3D
306 bool "Winchip-2A/Winchip-3"
307 help
308 Select this for an IDT Winchip-2A or 3. Linux and GCC
309 treat this chip as a 586TSC with some extended instructions
310 and alignment reqirements. Also enable out of order memory
311 stores for this CPU, which can increase performance of some
312 operations.
313
314config MGEODE
315 bool "MediaGX/Geode"
316 help
317 Select this for a Cyrix MediaGX aka Geode chip. Linux and GCC
318 treat this chip as a 586TSC with some extended instructions
319 and alignment reqirements.
320
321config MCYRIXIII
322 bool "CyrixIII/VIA-C3"
323 help
324 Select this for a Cyrix III or C3 chip. Presently Linux and GCC
325 treat this chip as a generic 586. Whilst the CPU is 686 class,
326 it lacks the cmov extension which gcc assumes is present when
327 generating 686 code.
328 Note that Nehemiah (Model 9) and above will not boot with this
329 kernel due to them lacking the 3DNow! instructions used in earlier
330 incarnations of the CPU.
331
332config MVIAC3_2
333 bool "VIA C3-2 (Nehemiah)"
334 help
335 Select this for a VIA C3 "Nehemiah". Selecting this enables usage
336 of SSE and tells gcc to treat the CPU as a 686.
337 Note, this kernel will not boot on older (pre model 9) C3s.
338
339endchoice
340
341config X86_GENERIC
342 bool "Generic x86 support"
343 help
344 Instead of just including optimizations for the selected
345 x86 variant (e.g. PII, Crusoe or Athlon), include some more
346 generic optimizations as well. This will make the kernel
347 perform better on x86 CPUs other than that selected.
348
349 This is really intended for distributors who need more
350 generic optimizations.
351
352endif
353
354#
355# Define implied options from the CPU selection here
356#
357config X86_CMPXCHG
358 bool
359 depends on !M386
360 default y
361
362config X86_XADD
363 bool
364 depends on !M386
365 default y
366
367config X86_L1_CACHE_SHIFT
368 int
369 default "7" if MPENTIUM4 || X86_GENERIC
370 default "4" if X86_ELAN || M486 || M386
371 default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE
372 default "6" if MK7 || MK8 || MPENTIUMM
373
374config RWSEM_GENERIC_SPINLOCK
375 bool
376 depends on M386
377 default y
378
379config RWSEM_XCHGADD_ALGORITHM
380 bool
381 depends on !M386
382 default y
383
384config GENERIC_CALIBRATE_DELAY
385 bool
386 default y
387
388config X86_PPRO_FENCE
389 bool
390 depends on M686 || M586MMX || M586TSC || M586 || M486 || M386 || MGEODE
391 default y
392
393config X86_F00F_BUG
394 bool
395 depends on M586MMX || M586TSC || M586 || M486 || M386
396 default y
397
398config X86_WP_WORKS_OK
399 bool
400 depends on !M386
401 default y
402
403config X86_INVLPG
404 bool
405 depends on !M386
406 default y
407
408config X86_BSWAP
409 bool
410 depends on !M386
411 default y
412
413config X86_POPAD_OK
414 bool
415 depends on !M386
416 default y
417
418config X86_ALIGNMENT_16
419 bool
420 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || X86_ELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODE
421 default y
422
423config X86_GOOD_APIC
424 bool
425 depends on MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8 || MEFFICEON
426 default y
427
428config X86_INTEL_USERCOPY
429 bool
430 depends on MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7 || MEFFICEON
431 default y
432
433config X86_USE_PPRO_CHECKSUM
434 bool
435 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2 || MEFFICEON
436 default y
437
438config X86_USE_3DNOW
439 bool
440 depends on MCYRIXIII || MK7
441 default y
442
443config X86_OOSTORE
444 bool
445 depends on (MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MGEODE) && MTRR
446 default y
447
448config HPET_TIMER
449 bool "HPET Timer Support"
450 help
451 This enables the use of the HPET for the kernel's internal timer.
452 HPET is the next generation timer replacing legacy 8254s.
453 You can safely choose Y here. However, HPET will only be
454 activated if the platform and the BIOS support this feature.
455 Otherwise the 8254 will be used for timing services.
456
457 Choose N to continue using the legacy 8254 timer.
458
459config HPET_EMULATE_RTC
460 bool "Provide RTC interrupt"
461 depends on HPET_TIMER && RTC=y
462
463config SMP
464 bool "Symmetric multi-processing support"
465 ---help---
466 This enables support for systems with more than one CPU. If you have
467 a system with only one CPU, like most personal computers, say N. If
468 you have a system with more than one CPU, say Y.
469
470 If you say N here, the kernel will run on single and multiprocessor
471 machines, but will use only one CPU of a multiprocessor machine. If
472 you say Y here, the kernel will run on many, but not all,
473 singleprocessor machines. On a singleprocessor machine, the kernel
474 will run faster if you say N here.
475
476 Note that if you say Y here and choose architecture "586" or
477 "Pentium" under "Processor family", the kernel will not work on 486
478 architectures. Similarly, multiprocessor kernels for the "PPro"
479 architecture may not work on all Pentium based boards.
480
481 People using multiprocessor machines who say Y here should also say
482 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
483 Management" code will be disabled if you say Y here.
484
485 See also the <file:Documentation/smp.txt>,
486 <file:Documentation/i386/IO-APIC.txt>,
487 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
488 <http://www.tldp.org/docs.html#howto>.
489
490 If you don't know what to do here, say N.
491
492config NR_CPUS
493 int "Maximum number of CPUs (2-255)"
494 range 2 255
495 depends on SMP
496 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
497 default "8"
498 help
499 This allows you to specify the maximum number of CPUs which this
500 kernel will support. The maximum supported value is 255 and the
501 minimum value which makes sense is 2.
502
503 This is purely to save memory - each supported CPU adds
504 approximately eight kilobytes to the kernel image.
505
506config SCHED_SMT
507 bool "SMT (Hyperthreading) scheduler support"
508 depends on SMP
509 default off
510 help
511 SMT scheduler support improves the CPU scheduler's decision making
512 when dealing with Intel Pentium 4 chips with HyperThreading at a
513 cost of slightly increased overhead in some places. If unsure say
514 N here.
515
516config PREEMPT
517 bool "Preemptible Kernel"
518 help
519 This option reduces the latency of the kernel when reacting to
520 real-time or interactive events by allowing a low priority process to
521 be preempted even if it is in kernel mode executing a system call.
522 This allows applications to run more reliably even when the system is
523 under load.
524
525 Say Y here if you are building a kernel for a desktop, embedded
526 or real-time system. Say N if you are unsure.
527
528config PREEMPT_BKL
529 bool "Preempt The Big Kernel Lock"
530 depends on PREEMPT
531 default y
532 help
533 This option reduces the latency of the kernel by making the
534 big kernel lock preemptible.
535
536 Say Y here if you are building a kernel for a desktop system.
537 Say N if you are unsure.
538
539config X86_UP_APIC
540 bool "Local APIC support on uniprocessors"
541 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
542 help
543 A local APIC (Advanced Programmable Interrupt Controller) is an
544 integrated interrupt controller in the CPU. If you have a single-CPU
545 system which has a processor with a local APIC, you can say Y here to
546 enable and use it. If you say Y here even though your machine doesn't
547 have a local APIC, then the kernel will still run with no slowdown at
548 all. The local APIC supports CPU-generated self-interrupts (timer,
549 performance counters), and the NMI watchdog which detects hard
550 lockups.
551
552config X86_UP_IOAPIC
553 bool "IO-APIC support on uniprocessors"
554 depends on X86_UP_APIC
555 help
556 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
557 SMP-capable replacement for PC-style interrupt controllers. Most
558 SMP systems and many recent uniprocessor systems have one.
559
560 If you have a single-CPU system with an IO-APIC, you can say Y here
561 to use it. If you say Y here even though your machine doesn't have
562 an IO-APIC, then the kernel will still run with no slowdown at all.
563
564config X86_LOCAL_APIC
565 bool
566 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
567 default y
568
569config X86_IO_APIC
570 bool
571 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
572 default y
573
574config X86_VISWS_APIC
575 bool
576 depends on X86_VISWS
577 default y
578
579config X86_TSC
580 bool
581 depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MEFFICEON || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2 || MGEODE) && !X86_NUMAQ
582 default y
583
584config X86_MCE
585 bool "Machine Check Exception"
586 depends on !X86_VOYAGER
587 ---help---
588 Machine Check Exception support allows the processor to notify the
589 kernel if it detects a problem (e.g. overheating, component failure).
590 The action the kernel takes depends on the severity of the problem,
591 ranging from a warning message on the console, to halting the machine.
592 Your processor must be a Pentium or newer to support this - check the
593 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
594 have a design flaw which leads to false MCE events - hence MCE is
595 disabled on all P5 processors, unless explicitly enabled with "mce"
596 as a boot argument. Similarly, if MCE is built in and creates a
597 problem on some new non-standard machine, you can boot with "nomce"
598 to disable it. MCE support simply ignores non-MCE processors like
599 the 386 and 486, so nearly everyone can say Y here.
600
601config X86_MCE_NONFATAL
602 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
603 depends on X86_MCE
604 help
605 Enabling this feature starts a timer that triggers every 5 seconds which
606 will look at the machine check registers to see if anything happened.
607 Non-fatal problems automatically get corrected (but still logged).
608 Disable this if you don't want to see these messages.
609 Seeing the messages this option prints out may be indicative of dying hardware,
610 or out-of-spec (ie, overclocked) hardware.
611 This option only does something on certain CPUs.
612 (AMD Athlon/Duron and Intel Pentium 4)
613
614config X86_MCE_P4THERMAL
615 bool "check for P4 thermal throttling interrupt."
616 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
617 help
618 Enabling this feature will cause a message to be printed when the P4
619 enters thermal throttling.
620
621config TOSHIBA
622 tristate "Toshiba Laptop support"
623 ---help---
624 This adds a driver to safely access the System Management Mode of
625 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
626 not work on models with a Phoenix BIOS. The System Management Mode
627 is used to set the BIOS and power saving options on Toshiba portables.
628
629 For information on utilities to make use of this driver see the
630 Toshiba Linux utilities web site at:
631 <http://www.buzzard.org.uk/toshiba/>.
632
633 Say Y if you intend to run this kernel on a Toshiba portable.
634 Say N otherwise.
635
636config I8K
637 tristate "Dell laptop support"
638 ---help---
639 This adds a driver to safely access the System Management Mode
640 of the CPU on the Dell Inspiron 8000. The System Management Mode
641 is used to read cpu temperature and cooling fan status and to
642 control the fans on the I8K portables.
643
644 This driver has been tested only on the Inspiron 8000 but it may
645 also work with other Dell laptops. You can force loading on other
646 models by passing the parameter `force=1' to the module. Use at
647 your own risk.
648
649 For information on utilities to make use of this driver see the
650 I8K Linux utilities web site at:
651 <http://people.debian.org/~dz/i8k/>
652
653 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
654 Say N otherwise.
655
656config MICROCODE
657 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
658 ---help---
659 If you say Y here and also to "/dev file system support" in the
660 'File systems' section, you will be able to update the microcode on
661 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
662 Pentium III, Pentium 4, Xeon etc. You will obviously need the
663 actual microcode binary data itself which is not shipped with the
664 Linux kernel.
665
666 For latest news and information on obtaining all the required
667 ingredients for this driver, check:
668 <http://www.urbanmyth.org/microcode/>.
669
670 To compile this driver as a module, choose M here: the
671 module will be called microcode.
672
673config X86_MSR
674 tristate "/dev/cpu/*/msr - Model-specific register support"
675 help
676 This device gives privileged processes access to the x86
677 Model-Specific Registers (MSRs). It is a character device with
678 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
679 MSR accesses are directed to a specific CPU on multi-processor
680 systems.
681
682config X86_CPUID
683 tristate "/dev/cpu/*/cpuid - CPU information support"
684 help
685 This device gives processes access to the x86 CPUID instruction to
686 be executed on a specific processor. It is a character device
687 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
688 /dev/cpu/31/cpuid.
689
690source "drivers/firmware/Kconfig"
691
692choice
693 prompt "High Memory Support"
694 default NOHIGHMEM
695
696config NOHIGHMEM
697 bool "off"
698 ---help---
699 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
700 However, the address space of 32-bit x86 processors is only 4
701 Gigabytes large. That means that, if you have a large amount of
702 physical memory, not all of it can be "permanently mapped" by the
703 kernel. The physical memory that's not permanently mapped is called
704 "high memory".
705
706 If you are compiling a kernel which will never run on a machine with
707 more than 1 Gigabyte total physical RAM, answer "off" here (default
708 choice and suitable for most users). This will result in a "3GB/1GB"
709 split: 3GB are mapped so that each process sees a 3GB virtual memory
710 space and the remaining part of the 4GB virtual memory space is used
711 by the kernel to permanently map as much physical memory as
712 possible.
713
714 If the machine has between 1 and 4 Gigabytes physical RAM, then
715 answer "4GB" here.
716
717 If more than 4 Gigabytes is used then answer "64GB" here. This
718 selection turns Intel PAE (Physical Address Extension) mode on.
719 PAE implements 3-level paging on IA32 processors. PAE is fully
720 supported by Linux, PAE mode is implemented on all recent Intel
721 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
722 then the kernel will not boot on CPUs that don't support PAE!
723
724 The actual amount of total physical memory will either be
725 auto detected or can be forced by using a kernel command line option
726 such as "mem=256M". (Try "man bootparam" or see the documentation of
727 your boot loader (lilo or loadlin) about how to pass options to the
728 kernel at boot time.)
729
730 If unsure, say "off".
731
732config HIGHMEM4G
733 bool "4GB"
734 help
735 Select this if you have a 32-bit processor and between 1 and 4
736 gigabytes of physical RAM.
737
738config HIGHMEM64G
739 bool "64GB"
740 help
741 Select this if you have a 32-bit processor and more than 4
742 gigabytes of physical RAM.
743
744endchoice
745
746config HIGHMEM
747 bool
748 depends on HIGHMEM64G || HIGHMEM4G
749 default y
750
751config X86_PAE
752 bool
753 depends on HIGHMEM64G
754 default y
755
756# Common NUMA Features
757config NUMA
758 bool "Numa Memory Allocation and Scheduler Support"
759 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
760 default n if X86_PC
761 default y if (X86_NUMAQ || X86_SUMMIT)
762
763# Need comments to help the hapless user trying to turn on NUMA support
764comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
765 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
766
767comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
768 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
769
770config DISCONTIGMEM
771 bool
772 depends on NUMA
773 default y
774
775config HAVE_ARCH_BOOTMEM_NODE
776 bool
777 depends on NUMA
778 default y
779
780config HAVE_MEMORY_PRESENT
781 bool
782 depends on DISCONTIGMEM
783 default y
784
785config NEED_NODE_MEMMAP_SIZE
786 bool
787 depends on DISCONTIGMEM
788 default y
789
790config HIGHPTE
791 bool "Allocate 3rd-level pagetables from highmem"
792 depends on HIGHMEM4G || HIGHMEM64G
793 help
794 The VM uses one page table entry for each page of physical memory.
795 For systems with a lot of RAM, this can be wasteful of precious
796 low memory. Setting this option will put user-space page table
797 entries in high memory.
798
799config MATH_EMULATION
800 bool "Math emulation"
801 ---help---
802 Linux can emulate a math coprocessor (used for floating point
803 operations) if you don't have one. 486DX and Pentium processors have
804 a math coprocessor built in, 486SX and 386 do not, unless you added
805 a 487DX or 387, respectively. (The messages during boot time can
806 give you some hints here ["man dmesg"].) Everyone needs either a
807 coprocessor or this emulation.
808
809 If you don't have a math coprocessor, you need to say Y here; if you
810 say Y here even though you have a coprocessor, the coprocessor will
811 be used nevertheless. (This behavior can be changed with the kernel
812 command line option "no387", which comes handy if your coprocessor
813 is broken. Try "man bootparam" or see the documentation of your boot
814 loader (lilo or loadlin) about how to pass options to the kernel at
815 boot time.) This means that it is a good idea to say Y here if you
816 intend to use this kernel on different machines.
817
818 More information about the internals of the Linux math coprocessor
819 emulation can be found in <file:arch/i386/math-emu/README>.
820
821 If you are not sure, say Y; apart from resulting in a 66 KB bigger
822 kernel, it won't hurt.
823
824config MTRR
825 bool "MTRR (Memory Type Range Register) support"
826 ---help---
827 On Intel P6 family processors (Pentium Pro, Pentium II and later)
828 the Memory Type Range Registers (MTRRs) may be used to control
829 processor access to memory ranges. This is most useful if you have
830 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
831 allows bus write transfers to be combined into a larger transfer
832 before bursting over the PCI/AGP bus. This can increase performance
833 of image write operations 2.5 times or more. Saying Y here creates a
834 /proc/mtrr file which may be used to manipulate your processor's
835 MTRRs. Typically the X server should use this.
836
837 This code has a reasonably generic interface so that similar
838 control registers on other processors can be easily supported
839 as well:
840
841 The Cyrix 6x86, 6x86MX and M II processors have Address Range
842 Registers (ARRs) which provide a similar functionality to MTRRs. For
843 these, the ARRs are used to emulate the MTRRs.
844 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
845 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
846 write-combining. All of these processors are supported by this code
847 and it makes sense to say Y here if you have one of them.
848
849 Saying Y here also fixes a problem with buggy SMP BIOSes which only
850 set the MTRRs for the boot CPU and not for the secondary CPUs. This
851 can lead to all sorts of problems, so it's good to say Y here.
852
853 You can safely say Y even if your machine doesn't have MTRRs, you'll
854 just add about 9 KB to your kernel.
855
856 See <file:Documentation/mtrr.txt> for more information.
857
858config EFI
859 bool "Boot from EFI support (EXPERIMENTAL)"
860 depends on ACPI
861 default n
862 ---help---
863 This enables the the kernel to boot on EFI platforms using
864 system configuration information passed to it from the firmware.
865 This also enables the kernel to use any EFI runtime services that are
866 available (such as the EFI variable services).
867
868 This option is only useful on systems that have EFI firmware
869 and will result in a kernel image that is ~8k larger. In addition,
870 you must use the latest ELILO loader available at
871 <http://elilo.sourceforge.net> in order to take advantage of
872 kernel initialization using EFI information (neither GRUB nor LILO know
873 anything about EFI). However, even with this option, the resultant
874 kernel should continue to boot on existing non-EFI platforms.
875
876config IRQBALANCE
877 bool "Enable kernel irq balancing"
878 depends on SMP && X86_IO_APIC
879 default y
880 help
881 The default yes will allow the kernel to do irq load balancing.
882 Saying no will keep the kernel from doing irq load balancing.
883
884config HAVE_DEC_LOCK
885 bool
886 depends on (SMP || PREEMPT) && X86_CMPXCHG
887 default y
888
889# turning this on wastes a bunch of space.
890# Summit needs it only when NUMA is on
891config BOOT_IOREMAP
892 bool
893 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
894 default y
895
896config REGPARM
897 bool "Use register arguments (EXPERIMENTAL)"
898 depends on EXPERIMENTAL
899 default n
900 help
901 Compile the kernel with -mregparm=3. This uses a different ABI
902 and passes the first three arguments of a function call in registers.
903 This will probably break binary only modules.
904
905 This feature is only enabled for gcc-3.0 and later - earlier compilers
906 generate incorrect output with certain kernel constructs when
907 -mregparm=3 is used.
908
909config SECCOMP
910 bool "Enable seccomp to safely compute untrusted bytecode"
911 depends on PROC_FS
912 default y
913 help
914 This kernel feature is useful for number crunching applications
915 that may need to compute untrusted bytecode during their
916 execution. By using pipes or other transports made available to
917 the process as file descriptors supporting the read/write
918 syscalls, it's possible to isolate those applications in
919 their own address space using seccomp. Once seccomp is
920 enabled via /proc/<pid>/seccomp, it cannot be disabled
921 and the task is only allowed to execute a few safe syscalls
922 defined by each seccomp mode.
923
924 If unsure, say Y. Only embedded should say N here.
925
926endmenu
927
928
929menu "Power management options (ACPI, APM)"
930 depends on !X86_VOYAGER
931
932source kernel/power/Kconfig
933
934source "drivers/acpi/Kconfig"
935
936menu "APM (Advanced Power Management) BIOS Support"
937depends on PM && !X86_VISWS
938
939config APM
940 tristate "APM (Advanced Power Management) BIOS support"
941 depends on PM
942 ---help---
943 APM is a BIOS specification for saving power using several different
944 techniques. This is mostly useful for battery powered laptops with
945 APM compliant BIOSes. If you say Y here, the system time will be
946 reset after a RESUME operation, the /proc/apm device will provide
947 battery status information, and user-space programs will receive
948 notification of APM "events" (e.g. battery status change).
949
950 If you select "Y" here, you can disable actual use of the APM
951 BIOS by passing the "apm=off" option to the kernel at boot time.
952
953 Note that the APM support is almost completely disabled for
954 machines with more than one CPU.
955
956 In order to use APM, you will need supporting software. For location
957 and more information, read <file:Documentation/pm.txt> and the
958 Battery Powered Linux mini-HOWTO, available from
959 <http://www.tldp.org/docs.html#howto>.
960
961 This driver does not spin down disk drives (see the hdparm(8)
962 manpage ("man 8 hdparm") for that), and it doesn't turn off
963 VESA-compliant "green" monitors.
964
965 This driver does not support the TI 4000M TravelMate and the ACER
966 486/DX4/75 because they don't have compliant BIOSes. Many "green"
967 desktop machines also don't have compliant BIOSes, and this driver
968 may cause those machines to panic during the boot phase.
969
970 Generally, if you don't have a battery in your machine, there isn't
971 much point in using this driver and you should say N. If you get
972 random kernel OOPSes or reboots that don't seem to be related to
973 anything, try disabling/enabling this option (or disabling/enabling
974 APM in your BIOS).
975
976 Some other things you should try when experiencing seemingly random,
977 "weird" problems:
978
979 1) make sure that you have enough swap space and that it is
980 enabled.
981 2) pass the "no-hlt" option to the kernel
982 3) switch on floating point emulation in the kernel and pass
983 the "no387" option to the kernel
984 4) pass the "floppy=nodma" option to the kernel
985 5) pass the "mem=4M" option to the kernel (thereby disabling
986 all but the first 4 MB of RAM)
987 6) make sure that the CPU is not over clocked.
988 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
989 8) disable the cache from your BIOS settings
990 9) install a fan for the video card or exchange video RAM
991 10) install a better fan for the CPU
992 11) exchange RAM chips
993 12) exchange the motherboard.
994
995 To compile this driver as a module, choose M here: the
996 module will be called apm.
997
998config APM_IGNORE_USER_SUSPEND
999 bool "Ignore USER SUSPEND"
1000 depends on APM
1001 help
1002 This option will ignore USER SUSPEND requests. On machines with a
1003 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1004 series notebooks, it is necessary to say Y because of a BIOS bug.
1005
1006config APM_DO_ENABLE
1007 bool "Enable PM at boot time"
1008 depends on APM
1009 ---help---
1010 Enable APM features at boot time. From page 36 of the APM BIOS
1011 specification: "When disabled, the APM BIOS does not automatically
1012 power manage devices, enter the Standby State, enter the Suspend
1013 State, or take power saving steps in response to CPU Idle calls."
1014 This driver will make CPU Idle calls when Linux is idle (unless this
1015 feature is turned off -- see "Do CPU IDLE calls", below). This
1016 should always save battery power, but more complicated APM features
1017 will be dependent on your BIOS implementation. You may need to turn
1018 this option off if your computer hangs at boot time when using APM
1019 support, or if it beeps continuously instead of suspending. Turn
1020 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1021 T400CDT. This is off by default since most machines do fine without
1022 this feature.
1023
1024config APM_CPU_IDLE
1025 bool "Make CPU Idle calls when idle"
1026 depends on APM
1027 help
1028 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1029 On some machines, this can activate improved power savings, such as
1030 a slowed CPU clock rate, when the machine is idle. These idle calls
1031 are made after the idle loop has run for some length of time (e.g.,
1032 333 mS). On some machines, this will cause a hang at boot time or
1033 whenever the CPU becomes idle. (On machines with more than one CPU,
1034 this option does nothing.)
1035
1036config APM_DISPLAY_BLANK
1037 bool "Enable console blanking using APM"
1038 depends on APM
1039 help
1040 Enable console blanking using the APM. Some laptops can use this to
1041 turn off the LCD backlight when the screen blanker of the Linux
1042 virtual console blanks the screen. Note that this is only used by
1043 the virtual console screen blanker, and won't turn off the backlight
1044 when using the X Window system. This also doesn't have anything to
1045 do with your VESA-compliant power-saving monitor. Further, this
1046 option doesn't work for all laptops -- it might not turn off your
1047 backlight at all, or it might print a lot of errors to the console,
1048 especially if you are using gpm.
1049
1050config APM_RTC_IS_GMT
1051 bool "RTC stores time in GMT"
1052 depends on APM
1053 help
1054 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
1055 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
1056 stores localtime.
1057
1058 It is in fact recommended to store GMT in your RTC, because then you
1059 don't have to worry about daylight savings time changes. The only
1060 reason not to use GMT in your RTC is if you also run a broken OS
1061 that doesn't understand GMT.
1062
1063config APM_ALLOW_INTS
1064 bool "Allow interrupts during APM BIOS calls"
1065 depends on APM
1066 help
1067 Normally we disable external interrupts while we are making calls to
1068 the APM BIOS as a measure to lessen the effects of a badly behaving
1069 BIOS implementation. The BIOS should reenable interrupts if it
1070 needs to. Unfortunately, some BIOSes do not -- especially those in
1071 many of the newer IBM Thinkpads. If you experience hangs when you
1072 suspend, try setting this to Y. Otherwise, say N.
1073
1074config APM_REAL_MODE_POWER_OFF
1075 bool "Use real mode APM BIOS call to power off"
1076 depends on APM
1077 help
1078 Use real mode APM BIOS calls to switch off the computer. This is
1079 a work-around for a number of buggy BIOSes. Switch this option on if
1080 your computer crashes instead of powering off properly.
1081
1082endmenu
1083
1084source "arch/i386/kernel/cpu/cpufreq/Kconfig"
1085
1086endmenu
1087
1088menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1089
1090config PCI
1091 bool "PCI support" if !X86_VISWS
1092 depends on !X86_VOYAGER
1093 default y if X86_VISWS
1094 help
1095 Find out whether you have a PCI motherboard. PCI is the name of a
1096 bus system, i.e. the way the CPU talks to the other stuff inside
1097 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1098 VESA. If you have PCI, say Y, otherwise N.
1099
1100 The PCI-HOWTO, available from
1101 <http://www.tldp.org/docs.html#howto>, contains valuable
1102 information about which PCI hardware does work under Linux and which
1103 doesn't.
1104
1105choice
1106 prompt "PCI access mode"
1107 depends on PCI && !X86_VISWS
1108 default PCI_GOANY
1109 ---help---
1110 On PCI systems, the BIOS can be used to detect the PCI devices and
1111 determine their configuration. However, some old PCI motherboards
1112 have BIOS bugs and may crash if this is done. Also, some embedded
1113 PCI-based systems don't have any BIOS at all. Linux can also try to
1114 detect the PCI hardware directly without using the BIOS.
1115
1116 With this option, you can specify how Linux should detect the
1117 PCI devices. If you choose "BIOS", the BIOS will be used,
1118 if you choose "Direct", the BIOS won't be used, and if you
1119 choose "MMConfig", then PCI Express MMCONFIG will be used.
1120 If you choose "Any", the kernel will try MMCONFIG, then the
1121 direct access method and falls back to the BIOS if that doesn't
1122 work. If unsure, go with the default, which is "Any".
1123
1124config PCI_GOBIOS
1125 bool "BIOS"
1126
1127config PCI_GOMMCONFIG
1128 bool "MMConfig"
1129
1130config PCI_GODIRECT
1131 bool "Direct"
1132
1133config PCI_GOANY
1134 bool "Any"
1135
1136endchoice
1137
1138config PCI_BIOS
1139 bool
1140 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1141 default y
1142
1143config PCI_DIRECT
1144 bool
1145 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1146 default y
1147
1148config PCI_MMCONFIG
1149 bool
1150 depends on PCI && (PCI_GOMMCONFIG || (PCI_GOANY && ACPI))
1151 select ACPI_BOOT
1152 default y
1153
1154source "drivers/pci/pcie/Kconfig"
1155
1156source "drivers/pci/Kconfig"
1157
1158config ISA
1159 bool "ISA support"
1160 depends on !(X86_VOYAGER || X86_VISWS)
1161 help
1162 Find out whether you have ISA slots on your motherboard. ISA is the
1163 name of a bus system, i.e. the way the CPU talks to the other stuff
1164 inside your box. Other bus systems are PCI, EISA, MicroChannel
1165 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1166 newer boards don't support it. If you have ISA, say Y, otherwise N.
1167
1168config EISA
1169 bool "EISA support"
1170 depends on ISA
1171 ---help---
1172 The Extended Industry Standard Architecture (EISA) bus was
1173 developed as an open alternative to the IBM MicroChannel bus.
1174
1175 The EISA bus provided some of the features of the IBM MicroChannel
1176 bus while maintaining backward compatibility with cards made for
1177 the older ISA bus. The EISA bus saw limited use between 1988 and
1178 1995 when it was made obsolete by the PCI bus.
1179
1180 Say Y here if you are building a kernel for an EISA-based machine.
1181
1182 Otherwise, say N.
1183
1184source "drivers/eisa/Kconfig"
1185
1186config MCA
1187 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1188 default y if X86_VOYAGER
1189 help
1190 MicroChannel Architecture is found in some IBM PS/2 machines and
1191 laptops. It is a bus system similar to PCI or ISA. See
1192 <file:Documentation/mca.txt> (and especially the web page given
1193 there) before attempting to build an MCA bus kernel.
1194
1195source "drivers/mca/Kconfig"
1196
1197config SCx200
1198 tristate "NatSemi SCx200 support"
1199 depends on !X86_VOYAGER
1200 help
1201 This provides basic support for the National Semiconductor SCx200
1202 processor. Right now this is just a driver for the GPIO pins.
1203
1204 If you don't know what to do here, say N.
1205
1206 This support is also available as a module. If compiled as a
1207 module, it will be called scx200.
1208
1209source "drivers/pcmcia/Kconfig"
1210
1211source "drivers/pci/hotplug/Kconfig"
1212
1213endmenu
1214
1215menu "Executable file formats"
1216
1217source "fs/Kconfig.binfmt"
1218
1219endmenu
1220
1221source "drivers/Kconfig"
1222
1223source "fs/Kconfig"
1224
1225source "arch/i386/oprofile/Kconfig"
1226
1227source "arch/i386/Kconfig.debug"
1228
1229source "security/Kconfig"
1230
1231source "crypto/Kconfig"
1232
1233source "lib/Kconfig"
1234
1235#
1236# Use the generic interrupt handling code in kernel/irq/:
1237#
1238config GENERIC_HARDIRQS
1239 bool
1240 default y
1241
1242config GENERIC_IRQ_PROBE
1243 bool
1244 default y
1245
1246config X86_SMP
1247 bool
1248 depends on SMP && !X86_VOYAGER
1249 default y
1250
1251config X86_HT
1252 bool
1253 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1254 default y
1255
1256config X86_BIOS_REBOOT
1257 bool
1258 depends on !(X86_VISWS || X86_VOYAGER)
1259 default y
1260
1261config X86_TRAMPOLINE
1262 bool
1263 depends on X86_SMP || (X86_VOYAGER && SMP)
1264 default y
1265
1266config PC
1267 bool
1268 depends on X86 && !EMBEDDED
1269 default y