1a69b68ff6cc6b1bec389523bb47bf924a776245
[deliverable/linux.git] / arch / x86 / Kconfig
1 # x86 configuration
2 mainmenu "Linux Kernel Configuration for x86"
3
4 # Select 32 or 64 bit
5 config 64BIT
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8 help
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
11
12 config X86_32
13 def_bool !64BIT
14
15 config X86_64
16 def_bool 64BIT
17
18 ### Arch settings
19 config X86
20 def_bool y
21 select HAVE_IDE
22 select HAVE_OPROFILE
23 select HAVE_KPROBES
24 select HAVE_KRETPROBES
25 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
26 select HAVE_ARCH_KGDB if !X86_VOYAGER
27
28
29 config GENERIC_LOCKBREAK
30 def_bool n
31
32 config GENERIC_TIME
33 def_bool y
34
35 config GENERIC_CMOS_UPDATE
36 def_bool y
37
38 config CLOCKSOURCE_WATCHDOG
39 def_bool y
40
41 config GENERIC_CLOCKEVENTS
42 def_bool y
43
44 config GENERIC_CLOCKEVENTS_BROADCAST
45 def_bool y
46 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
47
48 config LOCKDEP_SUPPORT
49 def_bool y
50
51 config STACKTRACE_SUPPORT
52 def_bool y
53
54 config HAVE_LATENCYTOP_SUPPORT
55 def_bool y
56
57 config FAST_CMPXCHG_LOCAL
58 bool
59 default y
60
61 config MMU
62 def_bool y
63
64 config ZONE_DMA
65 def_bool y
66
67 config SBUS
68 bool
69
70 config GENERIC_ISA_DMA
71 def_bool y
72
73 config GENERIC_IOMAP
74 def_bool y
75
76 config GENERIC_BUG
77 def_bool y
78 depends on BUG
79
80 config GENERIC_FIND_FIRST_BIT
81 def_bool X86_32
82
83 config GENERIC_FIND_NEXT_BIT
84 def_bool y
85
86 config GENERIC_HWEIGHT
87 def_bool y
88
89 config GENERIC_GPIO
90 def_bool n
91
92 config ARCH_MAY_HAVE_PC_FDC
93 def_bool y
94
95 config DMI
96 def_bool y
97
98 config RWSEM_GENERIC_SPINLOCK
99 def_bool !X86_XADD
100
101 config RWSEM_XCHGADD_ALGORITHM
102 def_bool X86_XADD
103
104 config ARCH_HAS_ILOG2_U32
105 def_bool n
106
107 config ARCH_HAS_ILOG2_U64
108 def_bool n
109
110 config ARCH_HAS_CPU_IDLE_WAIT
111 def_bool y
112
113 config GENERIC_CALIBRATE_DELAY
114 def_bool y
115
116 config GENERIC_TIME_VSYSCALL
117 bool
118 default X86_64
119
120 config ARCH_HAS_CPU_RELAX
121 def_bool y
122
123 config HAVE_SETUP_PER_CPU_AREA
124 def_bool X86_64 || (X86_SMP && !X86_VOYAGER)
125
126 config HAVE_CPUMASK_OF_CPU_MAP
127 def_bool X86_64_SMP
128
129 config ARCH_HIBERNATION_POSSIBLE
130 def_bool y
131 depends on !SMP || !X86_VOYAGER
132
133 config ARCH_SUSPEND_POSSIBLE
134 def_bool y
135 depends on !X86_VOYAGER
136
137 config ZONE_DMA32
138 bool
139 default X86_64
140
141 config ARCH_POPULATES_NODE_MAP
142 def_bool y
143
144 config AUDIT_ARCH
145 bool
146 default X86_64
147
148 config ARCH_SUPPORTS_AOUT
149 def_bool y
150
151 config ARCH_SUPPORTS_OPTIMIZED_INLINING
152 def_bool y
153
154 # Use the generic interrupt handling code in kernel/irq/:
155 config GENERIC_HARDIRQS
156 bool
157 default y
158
159 config GENERIC_IRQ_PROBE
160 bool
161 default y
162
163 config GENERIC_PENDING_IRQ
164 bool
165 depends on GENERIC_HARDIRQS && SMP
166 default y
167
168 config X86_SMP
169 bool
170 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
171 default y
172
173 config X86_32_SMP
174 def_bool y
175 depends on X86_32 && SMP
176
177 config X86_64_SMP
178 def_bool y
179 depends on X86_64 && SMP
180
181 config X86_HT
182 bool
183 depends on SMP
184 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || X86_64
185 default y
186
187 config X86_BIOS_REBOOT
188 bool
189 depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
190 default y
191
192 config X86_TRAMPOLINE
193 bool
194 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
195 default y
196
197 config KTIME_SCALAR
198 def_bool X86_32
199 source "init/Kconfig"
200
201 menu "Processor type and features"
202
203 source "kernel/time/Kconfig"
204
205 config SMP
206 bool "Symmetric multi-processing support"
207 ---help---
208 This enables support for systems with more than one CPU. If you have
209 a system with only one CPU, like most personal computers, say N. If
210 you have a system with more than one CPU, say Y.
211
212 If you say N here, the kernel will run on single and multiprocessor
213 machines, but will use only one CPU of a multiprocessor machine. If
214 you say Y here, the kernel will run on many, but not all,
215 singleprocessor machines. On a singleprocessor machine, the kernel
216 will run faster if you say N here.
217
218 Note that if you say Y here and choose architecture "586" or
219 "Pentium" under "Processor family", the kernel will not work on 486
220 architectures. Similarly, multiprocessor kernels for the "PPro"
221 architecture may not work on all Pentium based boards.
222
223 People using multiprocessor machines who say Y here should also say
224 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
225 Management" code will be disabled if you say Y here.
226
227 See also <file:Documentation/i386/IO-APIC.txt>,
228 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
229 <http://www.tldp.org/docs.html#howto>.
230
231 If you don't know what to do here, say N.
232
233 choice
234 prompt "Subarchitecture Type"
235 default X86_PC
236
237 config X86_PC
238 bool "PC-compatible"
239 help
240 Choose this option if your computer is a standard PC or compatible.
241
242 config X86_ELAN
243 bool "AMD Elan"
244 depends on X86_32
245 help
246 Select this for an AMD Elan processor.
247
248 Do not use this option for K6/Athlon/Opteron processors!
249
250 If unsure, choose "PC-compatible" instead.
251
252 config X86_VOYAGER
253 bool "Voyager (NCR)"
254 depends on X86_32 && (SMP || BROKEN)
255 help
256 Voyager is an MCA-based 32-way capable SMP architecture proprietary
257 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
258
259 *** WARNING ***
260
261 If you do not specifically know you have a Voyager based machine,
262 say N here, otherwise the kernel you build will not be bootable.
263
264 config X86_NUMAQ
265 bool "NUMAQ (IBM/Sequent)"
266 depends on SMP && X86_32
267 select NUMA
268 help
269 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
270 multiquad box. This changes the way that processors are bootstrapped,
271 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
272 You will need a new lynxer.elf file to flash your firmware with - send
273 email to <Martin.Bligh@us.ibm.com>.
274
275 config X86_SUMMIT
276 bool "Summit/EXA (IBM x440)"
277 depends on X86_32 && SMP
278 help
279 This option is needed for IBM systems that use the Summit/EXA chipset.
280 In particular, it is needed for the x440.
281
282 If you don't have one of these computers, you should say N here.
283 If you want to build a NUMA kernel, you must select ACPI.
284
285 config X86_BIGSMP
286 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
287 depends on X86_32 && SMP
288 help
289 This option is needed for the systems that have more than 8 CPUs
290 and if the system is not of any sub-arch type above.
291
292 If you don't have such a system, you should say N here.
293
294 config X86_VISWS
295 bool "SGI 320/540 (Visual Workstation)"
296 depends on X86_32
297 help
298 The SGI Visual Workstation series is an IA32-based workstation
299 based on SGI systems chips with some legacy PC hardware attached.
300
301 Say Y here to create a kernel to run on the SGI 320 or 540.
302
303 A kernel compiled for the Visual Workstation will not run on PCs
304 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
305
306 config X86_GENERICARCH
307 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
308 depends on X86_32
309 help
310 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
311 It is intended for a generic binary kernel.
312 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
313
314 config X86_ES7000
315 bool "Support for Unisys ES7000 IA32 series"
316 depends on X86_32 && SMP
317 help
318 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
319 supposed to run on an IA32-based Unisys ES7000 system.
320 Only choose this option if you have such a system, otherwise you
321 should say N here.
322
323 config X86_RDC321X
324 bool "RDC R-321x SoC"
325 depends on X86_32
326 select M486
327 select X86_REBOOTFIXUPS
328 select GENERIC_GPIO
329 select LEDS_CLASS
330 select LEDS_GPIO
331 help
332 This option is needed for RDC R-321x system-on-chip, also known
333 as R-8610-(G).
334 If you don't have one of these chips, you should say N here.
335
336 config X86_VSMP
337 bool "Support for ScaleMP vSMP"
338 select PARAVIRT
339 depends on X86_64
340 help
341 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
342 supposed to run on these EM64T-based machines. Only choose this option
343 if you have one of these machines.
344
345 endchoice
346
347 config SCHED_NO_NO_OMIT_FRAME_POINTER
348 def_bool y
349 prompt "Single-depth WCHAN output"
350 depends on X86_32
351 help
352 Calculate simpler /proc/<PID>/wchan values. If this option
353 is disabled then wchan values will recurse back to the
354 caller function. This provides more accurate wchan values,
355 at the expense of slightly more scheduling overhead.
356
357 If in doubt, say "Y".
358
359 menuconfig PARAVIRT_GUEST
360 bool "Paravirtualized guest support"
361 help
362 Say Y here to get to see options related to running Linux under
363 various hypervisors. This option alone does not add any kernel code.
364
365 If you say N, all options in this submenu will be skipped and disabled.
366
367 if PARAVIRT_GUEST
368
369 source "arch/x86/xen/Kconfig"
370
371 config VMI
372 bool "VMI Guest support"
373 select PARAVIRT
374 depends on X86_32
375 depends on !(X86_VISWS || X86_VOYAGER)
376 help
377 VMI provides a paravirtualized interface to the VMware ESX server
378 (it could be used by other hypervisors in theory too, but is not
379 at the moment), by linking the kernel to a GPL-ed ROM module
380 provided by the hypervisor.
381
382 source "arch/x86/lguest/Kconfig"
383
384 config PARAVIRT
385 bool "Enable paravirtualization code"
386 depends on !(X86_VISWS || X86_VOYAGER)
387 help
388 This changes the kernel so it can modify itself when it is run
389 under a hypervisor, potentially improving performance significantly
390 over full virtualization. However, when run without a hypervisor
391 the kernel is theoretically slower and slightly larger.
392
393 endif
394
395 config MEMTEST_BOOTPARAM
396 bool "Memtest boot parameter"
397 depends on X86_64
398 default y
399 help
400 This option adds a kernel parameter 'memtest', which allows memtest
401 to be disabled at boot. If this option is selected, memtest
402 functionality can be disabled with memtest=0 on the kernel
403 command line. The purpose of this option is to allow a single
404 kernel image to be distributed with memtest built in, but not
405 necessarily enabled.
406
407 If you are unsure how to answer this question, answer Y.
408
409 config MEMTEST_BOOTPARAM_VALUE
410 int "Memtest boot parameter default value (0-4)"
411 depends on MEMTEST_BOOTPARAM
412 range 0 4
413 default 0
414 help
415 This option sets the default value for the kernel parameter
416 'memtest', which allows memtest to be disabled at boot. If this
417 option is set to 0 (zero), the memtest kernel parameter will
418 default to 0, disabling memtest at bootup. If this option is
419 set to 4, the memtest kernel parameter will default to 4,
420 enabling memtest at bootup, and use that as pattern number.
421
422 If you are unsure how to answer this question, answer 0.
423
424 config ACPI_SRAT
425 def_bool y
426 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
427 select ACPI_NUMA
428
429 config HAVE_ARCH_PARSE_SRAT
430 def_bool y
431 depends on ACPI_SRAT
432
433 config X86_SUMMIT_NUMA
434 def_bool y
435 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
436
437 config X86_CYCLONE_TIMER
438 def_bool y
439 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
440
441 config ES7000_CLUSTERED_APIC
442 def_bool y
443 depends on SMP && X86_ES7000 && MPENTIUMIII
444
445 source "arch/x86/Kconfig.cpu"
446
447 config HPET_TIMER
448 def_bool X86_64
449 prompt "HPET Timer Support" if X86_32
450 help
451 Use the IA-PC HPET (High Precision Event Timer) to manage
452 time in preference to the PIT and RTC, if a HPET is
453 present.
454 HPET is the next generation timer replacing legacy 8254s.
455 The HPET provides a stable time base on SMP
456 systems, unlike the TSC, but it is more expensive to access,
457 as it is off-chip. You can find the HPET spec at
458 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
459
460 You can safely choose Y here. However, HPET will only be
461 activated if the platform and the BIOS support this feature.
462 Otherwise the 8254 will be used for timing services.
463
464 Choose N to continue using the legacy 8254 timer.
465
466 config HPET_EMULATE_RTC
467 def_bool y
468 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
469
470 # Mark as embedded because too many people got it wrong.
471 # The code disables itself when not needed.
472 config GART_IOMMU
473 bool "GART IOMMU support" if EMBEDDED
474 default y
475 select SWIOTLB
476 select AGP
477 depends on X86_64 && PCI
478 help
479 Support for full DMA access of devices with 32bit memory access only
480 on systems with more than 3GB. This is usually needed for USB,
481 sound, many IDE/SATA chipsets and some other devices.
482 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
483 based hardware IOMMU and a software bounce buffer based IOMMU used
484 on Intel systems and as fallback.
485 The code is only active when needed (enough memory and limited
486 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
487 too.
488
489 config CALGARY_IOMMU
490 bool "IBM Calgary IOMMU support"
491 select SWIOTLB
492 depends on X86_64 && PCI && EXPERIMENTAL
493 help
494 Support for hardware IOMMUs in IBM's xSeries x366 and x460
495 systems. Needed to run systems with more than 3GB of memory
496 properly with 32-bit PCI devices that do not support DAC
497 (Double Address Cycle). Calgary also supports bus level
498 isolation, where all DMAs pass through the IOMMU. This
499 prevents them from going anywhere except their intended
500 destination. This catches hard-to-find kernel bugs and
501 mis-behaving drivers and devices that do not use the DMA-API
502 properly to set up their DMA buffers. The IOMMU can be
503 turned off at boot time with the iommu=off parameter.
504 Normally the kernel will make the right choice by itself.
505 If unsure, say Y.
506
507 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
508 def_bool y
509 prompt "Should Calgary be enabled by default?"
510 depends on CALGARY_IOMMU
511 help
512 Should Calgary be enabled by default? if you choose 'y', Calgary
513 will be used (if it exists). If you choose 'n', Calgary will not be
514 used even if it exists. If you choose 'n' and would like to use
515 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
516 If unsure, say Y.
517
518 config IOMMU_HELPER
519 def_bool (CALGARY_IOMMU || GART_IOMMU)
520
521 # need this always selected by IOMMU for the VIA workaround
522 config SWIOTLB
523 bool
524 help
525 Support for software bounce buffers used on x86-64 systems
526 which don't have a hardware IOMMU (e.g. the current generation
527 of Intel's x86-64 CPUs). Using this PCI devices which can only
528 access 32-bits of memory can be used on systems with more than
529 3 GB of memory. If unsure, say Y.
530
531
532 config NR_CPUS
533 int "Maximum number of CPUs (2-255)"
534 range 2 255
535 depends on SMP
536 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
537 default "8"
538 help
539 This allows you to specify the maximum number of CPUs which this
540 kernel will support. The maximum supported value is 255 and the
541 minimum value which makes sense is 2.
542
543 This is purely to save memory - each supported CPU adds
544 approximately eight kilobytes to the kernel image.
545
546 config SCHED_SMT
547 bool "SMT (Hyperthreading) scheduler support"
548 depends on X86_HT
549 help
550 SMT scheduler support improves the CPU scheduler's decision making
551 when dealing with Intel Pentium 4 chips with HyperThreading at a
552 cost of slightly increased overhead in some places. If unsure say
553 N here.
554
555 config SCHED_MC
556 def_bool y
557 prompt "Multi-core scheduler support"
558 depends on X86_HT
559 help
560 Multi-core scheduler support improves the CPU scheduler's decision
561 making when dealing with multi-core CPU chips at a cost of slightly
562 increased overhead in some places. If unsure say N here.
563
564 source "kernel/Kconfig.preempt"
565
566 config X86_UP_APIC
567 bool "Local APIC support on uniprocessors"
568 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
569 help
570 A local APIC (Advanced Programmable Interrupt Controller) is an
571 integrated interrupt controller in the CPU. If you have a single-CPU
572 system which has a processor with a local APIC, you can say Y here to
573 enable and use it. If you say Y here even though your machine doesn't
574 have a local APIC, then the kernel will still run with no slowdown at
575 all. The local APIC supports CPU-generated self-interrupts (timer,
576 performance counters), and the NMI watchdog which detects hard
577 lockups.
578
579 config X86_UP_IOAPIC
580 bool "IO-APIC support on uniprocessors"
581 depends on X86_UP_APIC
582 help
583 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
584 SMP-capable replacement for PC-style interrupt controllers. Most
585 SMP systems and many recent uniprocessor systems have one.
586
587 If you have a single-CPU system with an IO-APIC, you can say Y here
588 to use it. If you say Y here even though your machine doesn't have
589 an IO-APIC, then the kernel will still run with no slowdown at all.
590
591 config X86_LOCAL_APIC
592 def_bool y
593 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
594
595 config X86_IO_APIC
596 def_bool y
597 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
598
599 config X86_VISWS_APIC
600 def_bool y
601 depends on X86_32 && X86_VISWS
602
603 config X86_MCE
604 bool "Machine Check Exception"
605 depends on !X86_VOYAGER
606 ---help---
607 Machine Check Exception support allows the processor to notify the
608 kernel if it detects a problem (e.g. overheating, component failure).
609 The action the kernel takes depends on the severity of the problem,
610 ranging from a warning message on the console, to halting the machine.
611 Your processor must be a Pentium or newer to support this - check the
612 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
613 have a design flaw which leads to false MCE events - hence MCE is
614 disabled on all P5 processors, unless explicitly enabled with "mce"
615 as a boot argument. Similarly, if MCE is built in and creates a
616 problem on some new non-standard machine, you can boot with "nomce"
617 to disable it. MCE support simply ignores non-MCE processors like
618 the 386 and 486, so nearly everyone can say Y here.
619
620 config X86_MCE_INTEL
621 def_bool y
622 prompt "Intel MCE features"
623 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
624 help
625 Additional support for intel specific MCE features such as
626 the thermal monitor.
627
628 config X86_MCE_AMD
629 def_bool y
630 prompt "AMD MCE features"
631 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
632 help
633 Additional support for AMD specific MCE features such as
634 the DRAM Error Threshold.
635
636 config X86_MCE_NONFATAL
637 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
638 depends on X86_32 && X86_MCE
639 help
640 Enabling this feature starts a timer that triggers every 5 seconds which
641 will look at the machine check registers to see if anything happened.
642 Non-fatal problems automatically get corrected (but still logged).
643 Disable this if you don't want to see these messages.
644 Seeing the messages this option prints out may be indicative of dying
645 or out-of-spec (ie, overclocked) hardware.
646 This option only does something on certain CPUs.
647 (AMD Athlon/Duron and Intel Pentium 4)
648
649 config X86_MCE_P4THERMAL
650 bool "check for P4 thermal throttling interrupt."
651 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
652 help
653 Enabling this feature will cause a message to be printed when the P4
654 enters thermal throttling.
655
656 config VM86
657 bool "Enable VM86 support" if EMBEDDED
658 default y
659 depends on X86_32
660 help
661 This option is required by programs like DOSEMU to run 16-bit legacy
662 code on X86 processors. It also may be needed by software like
663 XFree86 to initialize some video cards via BIOS. Disabling this
664 option saves about 6k.
665
666 config TOSHIBA
667 tristate "Toshiba Laptop support"
668 depends on X86_32
669 ---help---
670 This adds a driver to safely access the System Management Mode of
671 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
672 not work on models with a Phoenix BIOS. The System Management Mode
673 is used to set the BIOS and power saving options on Toshiba portables.
674
675 For information on utilities to make use of this driver see the
676 Toshiba Linux utilities web site at:
677 <http://www.buzzard.org.uk/toshiba/>.
678
679 Say Y if you intend to run this kernel on a Toshiba portable.
680 Say N otherwise.
681
682 config I8K
683 tristate "Dell laptop support"
684 ---help---
685 This adds a driver to safely access the System Management Mode
686 of the CPU on the Dell Inspiron 8000. The System Management Mode
687 is used to read cpu temperature and cooling fan status and to
688 control the fans on the I8K portables.
689
690 This driver has been tested only on the Inspiron 8000 but it may
691 also work with other Dell laptops. You can force loading on other
692 models by passing the parameter `force=1' to the module. Use at
693 your own risk.
694
695 For information on utilities to make use of this driver see the
696 I8K Linux utilities web site at:
697 <http://people.debian.org/~dz/i8k/>
698
699 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
700 Say N otherwise.
701
702 config X86_REBOOTFIXUPS
703 def_bool n
704 prompt "Enable X86 board specific fixups for reboot"
705 depends on X86_32 && X86
706 ---help---
707 This enables chipset and/or board specific fixups to be done
708 in order to get reboot to work correctly. This is only needed on
709 some combinations of hardware and BIOS. The symptom, for which
710 this config is intended, is when reboot ends with a stalled/hung
711 system.
712
713 Currently, the only fixup is for the Geode machines using
714 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
715
716 Say Y if you want to enable the fixup. Currently, it's safe to
717 enable this option even if you don't need it.
718 Say N otherwise.
719
720 config MICROCODE
721 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
722 select FW_LOADER
723 ---help---
724 If you say Y here, you will be able to update the microcode on
725 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
726 Pentium III, Pentium 4, Xeon etc. You will obviously need the
727 actual microcode binary data itself which is not shipped with the
728 Linux kernel.
729
730 For latest news and information on obtaining all the required
731 ingredients for this driver, check:
732 <http://www.urbanmyth.org/microcode/>.
733
734 To compile this driver as a module, choose M here: the
735 module will be called microcode.
736
737 config MICROCODE_OLD_INTERFACE
738 def_bool y
739 depends on MICROCODE
740
741 config X86_MSR
742 tristate "/dev/cpu/*/msr - Model-specific register support"
743 help
744 This device gives privileged processes access to the x86
745 Model-Specific Registers (MSRs). It is a character device with
746 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
747 MSR accesses are directed to a specific CPU on multi-processor
748 systems.
749
750 config X86_CPUID
751 tristate "/dev/cpu/*/cpuid - CPU information support"
752 help
753 This device gives processes access to the x86 CPUID instruction to
754 be executed on a specific processor. It is a character device
755 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
756 /dev/cpu/31/cpuid.
757
758 choice
759 prompt "High Memory Support"
760 default HIGHMEM4G if !X86_NUMAQ
761 default HIGHMEM64G if X86_NUMAQ
762 depends on X86_32
763
764 config NOHIGHMEM
765 bool "off"
766 depends on !X86_NUMAQ
767 ---help---
768 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
769 However, the address space of 32-bit x86 processors is only 4
770 Gigabytes large. That means that, if you have a large amount of
771 physical memory, not all of it can be "permanently mapped" by the
772 kernel. The physical memory that's not permanently mapped is called
773 "high memory".
774
775 If you are compiling a kernel which will never run on a machine with
776 more than 1 Gigabyte total physical RAM, answer "off" here (default
777 choice and suitable for most users). This will result in a "3GB/1GB"
778 split: 3GB are mapped so that each process sees a 3GB virtual memory
779 space and the remaining part of the 4GB virtual memory space is used
780 by the kernel to permanently map as much physical memory as
781 possible.
782
783 If the machine has between 1 and 4 Gigabytes physical RAM, then
784 answer "4GB" here.
785
786 If more than 4 Gigabytes is used then answer "64GB" here. This
787 selection turns Intel PAE (Physical Address Extension) mode on.
788 PAE implements 3-level paging on IA32 processors. PAE is fully
789 supported by Linux, PAE mode is implemented on all recent Intel
790 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
791 then the kernel will not boot on CPUs that don't support PAE!
792
793 The actual amount of total physical memory will either be
794 auto detected or can be forced by using a kernel command line option
795 such as "mem=256M". (Try "man bootparam" or see the documentation of
796 your boot loader (lilo or loadlin) about how to pass options to the
797 kernel at boot time.)
798
799 If unsure, say "off".
800
801 config HIGHMEM4G
802 bool "4GB"
803 depends on !X86_NUMAQ
804 help
805 Select this if you have a 32-bit processor and between 1 and 4
806 gigabytes of physical RAM.
807
808 config HIGHMEM64G
809 bool "64GB"
810 depends on !M386 && !M486
811 select X86_PAE
812 help
813 Select this if you have a 32-bit processor and more than 4
814 gigabytes of physical RAM.
815
816 endchoice
817
818 choice
819 depends on EXPERIMENTAL
820 prompt "Memory split" if EMBEDDED
821 default VMSPLIT_3G
822 depends on X86_32
823 help
824 Select the desired split between kernel and user memory.
825
826 If the address range available to the kernel is less than the
827 physical memory installed, the remaining memory will be available
828 as "high memory". Accessing high memory is a little more costly
829 than low memory, as it needs to be mapped into the kernel first.
830 Note that increasing the kernel address space limits the range
831 available to user programs, making the address space there
832 tighter. Selecting anything other than the default 3G/1G split
833 will also likely make your kernel incompatible with binary-only
834 kernel modules.
835
836 If you are not absolutely sure what you are doing, leave this
837 option alone!
838
839 config VMSPLIT_3G
840 bool "3G/1G user/kernel split"
841 config VMSPLIT_3G_OPT
842 depends on !X86_PAE
843 bool "3G/1G user/kernel split (for full 1G low memory)"
844 config VMSPLIT_2G
845 bool "2G/2G user/kernel split"
846 config VMSPLIT_2G_OPT
847 depends on !X86_PAE
848 bool "2G/2G user/kernel split (for full 2G low memory)"
849 config VMSPLIT_1G
850 bool "1G/3G user/kernel split"
851 endchoice
852
853 config PAGE_OFFSET
854 hex
855 default 0xB0000000 if VMSPLIT_3G_OPT
856 default 0x80000000 if VMSPLIT_2G
857 default 0x78000000 if VMSPLIT_2G_OPT
858 default 0x40000000 if VMSPLIT_1G
859 default 0xC0000000
860 depends on X86_32
861
862 config HIGHMEM
863 def_bool y
864 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
865
866 config X86_PAE
867 def_bool n
868 prompt "PAE (Physical Address Extension) Support"
869 depends on X86_32 && !HIGHMEM4G
870 select RESOURCES_64BIT
871 help
872 PAE is required for NX support, and furthermore enables
873 larger swapspace support for non-overcommit purposes. It
874 has the cost of more pagetable lookup overhead, and also
875 consumes more pagetable space per process.
876
877 # Common NUMA Features
878 config NUMA
879 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
880 depends on SMP
881 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
882 default n if X86_PC
883 default y if (X86_NUMAQ || X86_SUMMIT)
884 help
885 Enable NUMA (Non Uniform Memory Access) support.
886 The kernel will try to allocate memory used by a CPU on the
887 local memory controller of the CPU and add some more
888 NUMA awareness to the kernel.
889
890 For i386 this is currently highly experimental and should be only
891 used for kernel development. It might also cause boot failures.
892 For x86_64 this is recommended on all multiprocessor Opteron systems.
893 If the system is EM64T, you should say N unless your system is
894 EM64T NUMA.
895
896 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
897 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
898
899 config K8_NUMA
900 def_bool y
901 prompt "Old style AMD Opteron NUMA detection"
902 depends on X86_64 && NUMA && PCI
903 help
904 Enable K8 NUMA node topology detection. You should say Y here if
905 you have a multi processor AMD K8 system. This uses an old
906 method to read the NUMA configuration directly from the builtin
907 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
908 instead, which also takes priority if both are compiled in.
909
910 config X86_64_ACPI_NUMA
911 def_bool y
912 prompt "ACPI NUMA detection"
913 depends on X86_64 && NUMA && ACPI && PCI
914 select ACPI_NUMA
915 help
916 Enable ACPI SRAT based node topology detection.
917
918 # Some NUMA nodes have memory ranges that span
919 # other nodes. Even though a pfn is valid and
920 # between a node's start and end pfns, it may not
921 # reside on that node. See memmap_init_zone()
922 # for details.
923 config NODES_SPAN_OTHER_NODES
924 def_bool y
925 depends on X86_64_ACPI_NUMA
926
927 config NUMA_EMU
928 bool "NUMA emulation"
929 depends on X86_64 && NUMA
930 help
931 Enable NUMA emulation. A flat machine will be split
932 into virtual nodes when booted with "numa=fake=N", where N is the
933 number of nodes. This is only useful for debugging.
934
935 config NODES_SHIFT
936 int "Max num nodes shift(1-15)"
937 range 1 15 if X86_64
938 default "6" if X86_64
939 default "4" if X86_NUMAQ
940 default "3"
941 depends on NEED_MULTIPLE_NODES
942
943 config HAVE_ARCH_BOOTMEM_NODE
944 def_bool y
945 depends on X86_32 && NUMA
946
947 config ARCH_HAVE_MEMORY_PRESENT
948 def_bool y
949 depends on X86_32 && DISCONTIGMEM
950
951 config NEED_NODE_MEMMAP_SIZE
952 def_bool y
953 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
954
955 config HAVE_ARCH_ALLOC_REMAP
956 def_bool y
957 depends on X86_32 && NUMA
958
959 config ARCH_FLATMEM_ENABLE
960 def_bool y
961 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
962
963 config ARCH_DISCONTIGMEM_ENABLE
964 def_bool y
965 depends on NUMA && X86_32
966
967 config ARCH_DISCONTIGMEM_DEFAULT
968 def_bool y
969 depends on NUMA && X86_32
970
971 config ARCH_SPARSEMEM_DEFAULT
972 def_bool y
973 depends on X86_64
974
975 config ARCH_SPARSEMEM_ENABLE
976 def_bool y
977 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
978 select SPARSEMEM_STATIC if X86_32
979 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
980
981 config ARCH_SELECT_MEMORY_MODEL
982 def_bool y
983 depends on ARCH_SPARSEMEM_ENABLE
984
985 config ARCH_MEMORY_PROBE
986 def_bool X86_64
987 depends on MEMORY_HOTPLUG
988
989 source "mm/Kconfig"
990
991 config HIGHPTE
992 bool "Allocate 3rd-level pagetables from highmem"
993 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
994 help
995 The VM uses one page table entry for each page of physical memory.
996 For systems with a lot of RAM, this can be wasteful of precious
997 low memory. Setting this option will put user-space page table
998 entries in high memory.
999
1000 config MATH_EMULATION
1001 bool
1002 prompt "Math emulation" if X86_32
1003 ---help---
1004 Linux can emulate a math coprocessor (used for floating point
1005 operations) if you don't have one. 486DX and Pentium processors have
1006 a math coprocessor built in, 486SX and 386 do not, unless you added
1007 a 487DX or 387, respectively. (The messages during boot time can
1008 give you some hints here ["man dmesg"].) Everyone needs either a
1009 coprocessor or this emulation.
1010
1011 If you don't have a math coprocessor, you need to say Y here; if you
1012 say Y here even though you have a coprocessor, the coprocessor will
1013 be used nevertheless. (This behavior can be changed with the kernel
1014 command line option "no387", which comes handy if your coprocessor
1015 is broken. Try "man bootparam" or see the documentation of your boot
1016 loader (lilo or loadlin) about how to pass options to the kernel at
1017 boot time.) This means that it is a good idea to say Y here if you
1018 intend to use this kernel on different machines.
1019
1020 More information about the internals of the Linux math coprocessor
1021 emulation can be found in <file:arch/x86/math-emu/README>.
1022
1023 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1024 kernel, it won't hurt.
1025
1026 config MTRR
1027 bool "MTRR (Memory Type Range Register) support"
1028 ---help---
1029 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1030 the Memory Type Range Registers (MTRRs) may be used to control
1031 processor access to memory ranges. This is most useful if you have
1032 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1033 allows bus write transfers to be combined into a larger transfer
1034 before bursting over the PCI/AGP bus. This can increase performance
1035 of image write operations 2.5 times or more. Saying Y here creates a
1036 /proc/mtrr file which may be used to manipulate your processor's
1037 MTRRs. Typically the X server should use this.
1038
1039 This code has a reasonably generic interface so that similar
1040 control registers on other processors can be easily supported
1041 as well:
1042
1043 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1044 Registers (ARRs) which provide a similar functionality to MTRRs. For
1045 these, the ARRs are used to emulate the MTRRs.
1046 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1047 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1048 write-combining. All of these processors are supported by this code
1049 and it makes sense to say Y here if you have one of them.
1050
1051 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1052 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1053 can lead to all sorts of problems, so it's good to say Y here.
1054
1055 You can safely say Y even if your machine doesn't have MTRRs, you'll
1056 just add about 9 KB to your kernel.
1057
1058 See <file:Documentation/mtrr.txt> for more information.
1059
1060 config X86_PAT
1061 bool
1062 prompt "x86 PAT support"
1063 depends on MTRR
1064 help
1065 Use PAT attributes to setup page level cache control.
1066
1067 PATs are the modern equivalents of MTRRs and are much more
1068 flexible than MTRRs.
1069
1070 Say N here if you see bootup problems (boot crash, boot hang,
1071 spontaneous reboots) or a non-working video driver.
1072
1073 If unsure, say Y.
1074
1075 config EFI
1076 def_bool n
1077 prompt "EFI runtime service support"
1078 depends on ACPI
1079 ---help---
1080 This enables the kernel to use EFI runtime services that are
1081 available (such as the EFI variable services).
1082
1083 This option is only useful on systems that have EFI firmware.
1084 In addition, you should use the latest ELILO loader available
1085 at <http://elilo.sourceforge.net> in order to take advantage
1086 of EFI runtime services. However, even with this option, the
1087 resultant kernel should continue to boot on existing non-EFI
1088 platforms.
1089
1090 config IRQBALANCE
1091 def_bool y
1092 prompt "Enable kernel irq balancing"
1093 depends on X86_32 && SMP && X86_IO_APIC
1094 help
1095 The default yes will allow the kernel to do irq load balancing.
1096 Saying no will keep the kernel from doing irq load balancing.
1097
1098 config SECCOMP
1099 def_bool y
1100 prompt "Enable seccomp to safely compute untrusted bytecode"
1101 depends on PROC_FS
1102 help
1103 This kernel feature is useful for number crunching applications
1104 that may need to compute untrusted bytecode during their
1105 execution. By using pipes or other transports made available to
1106 the process as file descriptors supporting the read/write
1107 syscalls, it's possible to isolate those applications in
1108 their own address space using seccomp. Once seccomp is
1109 enabled via /proc/<pid>/seccomp, it cannot be disabled
1110 and the task is only allowed to execute a few safe syscalls
1111 defined by each seccomp mode.
1112
1113 If unsure, say Y. Only embedded should say N here.
1114
1115 config CC_STACKPROTECTOR
1116 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1117 depends on X86_64 && EXPERIMENTAL && BROKEN
1118 help
1119 This option turns on the -fstack-protector GCC feature. This
1120 feature puts, at the beginning of critical functions, a canary
1121 value on the stack just before the return address, and validates
1122 the value just before actually returning. Stack based buffer
1123 overflows (that need to overwrite this return address) now also
1124 overwrite the canary, which gets detected and the attack is then
1125 neutralized via a kernel panic.
1126
1127 This feature requires gcc version 4.2 or above, or a distribution
1128 gcc with the feature backported. Older versions are automatically
1129 detected and for those versions, this configuration option is ignored.
1130
1131 config CC_STACKPROTECTOR_ALL
1132 bool "Use stack-protector for all functions"
1133 depends on CC_STACKPROTECTOR
1134 help
1135 Normally, GCC only inserts the canary value protection for
1136 functions that use large-ish on-stack buffers. By enabling
1137 this option, GCC will be asked to do this for ALL functions.
1138
1139 source kernel/Kconfig.hz
1140
1141 config KEXEC
1142 bool "kexec system call"
1143 depends on X86_64 || X86_BIOS_REBOOT
1144 help
1145 kexec is a system call that implements the ability to shutdown your
1146 current kernel, and to start another kernel. It is like a reboot
1147 but it is independent of the system firmware. And like a reboot
1148 you can start any kernel with it, not just Linux.
1149
1150 The name comes from the similarity to the exec system call.
1151
1152 It is an ongoing process to be certain the hardware in a machine
1153 is properly shutdown, so do not be surprised if this code does not
1154 initially work for you. It may help to enable device hotplugging
1155 support. As of this writing the exact hardware interface is
1156 strongly in flux, so no good recommendation can be made.
1157
1158 config CRASH_DUMP
1159 bool "kernel crash dumps (EXPERIMENTAL)"
1160 depends on EXPERIMENTAL
1161 depends on X86_64 || (X86_32 && HIGHMEM)
1162 help
1163 Generate crash dump after being started by kexec.
1164 This should be normally only set in special crash dump kernels
1165 which are loaded in the main kernel with kexec-tools into
1166 a specially reserved region and then later executed after
1167 a crash by kdump/kexec. The crash dump kernel must be compiled
1168 to a memory address not used by the main kernel or BIOS using
1169 PHYSICAL_START, or it must be built as a relocatable image
1170 (CONFIG_RELOCATABLE=y).
1171 For more details see Documentation/kdump/kdump.txt
1172
1173 config PHYSICAL_START
1174 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1175 default "0x1000000" if X86_NUMAQ
1176 default "0x200000" if X86_64
1177 default "0x100000"
1178 help
1179 This gives the physical address where the kernel is loaded.
1180
1181 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1182 bzImage will decompress itself to above physical address and
1183 run from there. Otherwise, bzImage will run from the address where
1184 it has been loaded by the boot loader and will ignore above physical
1185 address.
1186
1187 In normal kdump cases one does not have to set/change this option
1188 as now bzImage can be compiled as a completely relocatable image
1189 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1190 address. This option is mainly useful for the folks who don't want
1191 to use a bzImage for capturing the crash dump and want to use a
1192 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1193 to be specifically compiled to run from a specific memory area
1194 (normally a reserved region) and this option comes handy.
1195
1196 So if you are using bzImage for capturing the crash dump, leave
1197 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1198 Otherwise if you plan to use vmlinux for capturing the crash dump
1199 change this value to start of the reserved region (Typically 16MB
1200 0x1000000). In other words, it can be set based on the "X" value as
1201 specified in the "crashkernel=YM@XM" command line boot parameter
1202 passed to the panic-ed kernel. Typically this parameter is set as
1203 crashkernel=64M@16M. Please take a look at
1204 Documentation/kdump/kdump.txt for more details about crash dumps.
1205
1206 Usage of bzImage for capturing the crash dump is recommended as
1207 one does not have to build two kernels. Same kernel can be used
1208 as production kernel and capture kernel. Above option should have
1209 gone away after relocatable bzImage support is introduced. But it
1210 is present because there are users out there who continue to use
1211 vmlinux for dump capture. This option should go away down the
1212 line.
1213
1214 Don't change this unless you know what you are doing.
1215
1216 config RELOCATABLE
1217 bool "Build a relocatable kernel (EXPERIMENTAL)"
1218 depends on EXPERIMENTAL
1219 help
1220 This builds a kernel image that retains relocation information
1221 so it can be loaded someplace besides the default 1MB.
1222 The relocations tend to make the kernel binary about 10% larger,
1223 but are discarded at runtime.
1224
1225 One use is for the kexec on panic case where the recovery kernel
1226 must live at a different physical address than the primary
1227 kernel.
1228
1229 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1230 it has been loaded at and the compile time physical address
1231 (CONFIG_PHYSICAL_START) is ignored.
1232
1233 config PHYSICAL_ALIGN
1234 hex
1235 prompt "Alignment value to which kernel should be aligned" if X86_32
1236 default "0x100000" if X86_32
1237 default "0x200000" if X86_64
1238 range 0x2000 0x400000
1239 help
1240 This value puts the alignment restrictions on physical address
1241 where kernel is loaded and run from. Kernel is compiled for an
1242 address which meets above alignment restriction.
1243
1244 If bootloader loads the kernel at a non-aligned address and
1245 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1246 address aligned to above value and run from there.
1247
1248 If bootloader loads the kernel at a non-aligned address and
1249 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1250 load address and decompress itself to the address it has been
1251 compiled for and run from there. The address for which kernel is
1252 compiled already meets above alignment restrictions. Hence the
1253 end result is that kernel runs from a physical address meeting
1254 above alignment restrictions.
1255
1256 Don't change this unless you know what you are doing.
1257
1258 config HOTPLUG_CPU
1259 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1260 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1261 ---help---
1262 Say Y here to experiment with turning CPUs off and on, and to
1263 enable suspend on SMP systems. CPUs can be controlled through
1264 /sys/devices/system/cpu.
1265 Say N if you want to disable CPU hotplug and don't need to
1266 suspend.
1267
1268 config COMPAT_VDSO
1269 def_bool y
1270 prompt "Compat VDSO support"
1271 depends on X86_32 || IA32_EMULATION
1272 help
1273 Map the 32-bit VDSO to the predictable old-style address too.
1274 ---help---
1275 Say N here if you are running a sufficiently recent glibc
1276 version (2.3.3 or later), to remove the high-mapped
1277 VDSO mapping and to exclusively use the randomized VDSO.
1278
1279 If unsure, say Y.
1280
1281 endmenu
1282
1283 config ARCH_ENABLE_MEMORY_HOTPLUG
1284 def_bool y
1285 depends on X86_64 || (X86_32 && HIGHMEM)
1286
1287 config HAVE_ARCH_EARLY_PFN_TO_NID
1288 def_bool X86_64
1289 depends on NUMA
1290
1291 menu "Power management options"
1292 depends on !X86_VOYAGER
1293
1294 config ARCH_HIBERNATION_HEADER
1295 def_bool y
1296 depends on X86_64 && HIBERNATION
1297
1298 source "kernel/power/Kconfig"
1299
1300 source "drivers/acpi/Kconfig"
1301
1302 config X86_APM_BOOT
1303 bool
1304 default y
1305 depends on APM || APM_MODULE
1306
1307 menuconfig APM
1308 tristate "APM (Advanced Power Management) BIOS support"
1309 depends on X86_32 && PM_SLEEP && !X86_VISWS
1310 ---help---
1311 APM is a BIOS specification for saving power using several different
1312 techniques. This is mostly useful for battery powered laptops with
1313 APM compliant BIOSes. If you say Y here, the system time will be
1314 reset after a RESUME operation, the /proc/apm device will provide
1315 battery status information, and user-space programs will receive
1316 notification of APM "events" (e.g. battery status change).
1317
1318 If you select "Y" here, you can disable actual use of the APM
1319 BIOS by passing the "apm=off" option to the kernel at boot time.
1320
1321 Note that the APM support is almost completely disabled for
1322 machines with more than one CPU.
1323
1324 In order to use APM, you will need supporting software. For location
1325 and more information, read <file:Documentation/power/pm.txt> and the
1326 Battery Powered Linux mini-HOWTO, available from
1327 <http://www.tldp.org/docs.html#howto>.
1328
1329 This driver does not spin down disk drives (see the hdparm(8)
1330 manpage ("man 8 hdparm") for that), and it doesn't turn off
1331 VESA-compliant "green" monitors.
1332
1333 This driver does not support the TI 4000M TravelMate and the ACER
1334 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1335 desktop machines also don't have compliant BIOSes, and this driver
1336 may cause those machines to panic during the boot phase.
1337
1338 Generally, if you don't have a battery in your machine, there isn't
1339 much point in using this driver and you should say N. If you get
1340 random kernel OOPSes or reboots that don't seem to be related to
1341 anything, try disabling/enabling this option (or disabling/enabling
1342 APM in your BIOS).
1343
1344 Some other things you should try when experiencing seemingly random,
1345 "weird" problems:
1346
1347 1) make sure that you have enough swap space and that it is
1348 enabled.
1349 2) pass the "no-hlt" option to the kernel
1350 3) switch on floating point emulation in the kernel and pass
1351 the "no387" option to the kernel
1352 4) pass the "floppy=nodma" option to the kernel
1353 5) pass the "mem=4M" option to the kernel (thereby disabling
1354 all but the first 4 MB of RAM)
1355 6) make sure that the CPU is not over clocked.
1356 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1357 8) disable the cache from your BIOS settings
1358 9) install a fan for the video card or exchange video RAM
1359 10) install a better fan for the CPU
1360 11) exchange RAM chips
1361 12) exchange the motherboard.
1362
1363 To compile this driver as a module, choose M here: the
1364 module will be called apm.
1365
1366 if APM
1367
1368 config APM_IGNORE_USER_SUSPEND
1369 bool "Ignore USER SUSPEND"
1370 help
1371 This option will ignore USER SUSPEND requests. On machines with a
1372 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1373 series notebooks, it is necessary to say Y because of a BIOS bug.
1374
1375 config APM_DO_ENABLE
1376 bool "Enable PM at boot time"
1377 ---help---
1378 Enable APM features at boot time. From page 36 of the APM BIOS
1379 specification: "When disabled, the APM BIOS does not automatically
1380 power manage devices, enter the Standby State, enter the Suspend
1381 State, or take power saving steps in response to CPU Idle calls."
1382 This driver will make CPU Idle calls when Linux is idle (unless this
1383 feature is turned off -- see "Do CPU IDLE calls", below). This
1384 should always save battery power, but more complicated APM features
1385 will be dependent on your BIOS implementation. You may need to turn
1386 this option off if your computer hangs at boot time when using APM
1387 support, or if it beeps continuously instead of suspending. Turn
1388 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1389 T400CDT. This is off by default since most machines do fine without
1390 this feature.
1391
1392 config APM_CPU_IDLE
1393 bool "Make CPU Idle calls when idle"
1394 help
1395 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1396 On some machines, this can activate improved power savings, such as
1397 a slowed CPU clock rate, when the machine is idle. These idle calls
1398 are made after the idle loop has run for some length of time (e.g.,
1399 333 mS). On some machines, this will cause a hang at boot time or
1400 whenever the CPU becomes idle. (On machines with more than one CPU,
1401 this option does nothing.)
1402
1403 config APM_DISPLAY_BLANK
1404 bool "Enable console blanking using APM"
1405 help
1406 Enable console blanking using the APM. Some laptops can use this to
1407 turn off the LCD backlight when the screen blanker of the Linux
1408 virtual console blanks the screen. Note that this is only used by
1409 the virtual console screen blanker, and won't turn off the backlight
1410 when using the X Window system. This also doesn't have anything to
1411 do with your VESA-compliant power-saving monitor. Further, this
1412 option doesn't work for all laptops -- it might not turn off your
1413 backlight at all, or it might print a lot of errors to the console,
1414 especially if you are using gpm.
1415
1416 config APM_ALLOW_INTS
1417 bool "Allow interrupts during APM BIOS calls"
1418 help
1419 Normally we disable external interrupts while we are making calls to
1420 the APM BIOS as a measure to lessen the effects of a badly behaving
1421 BIOS implementation. The BIOS should reenable interrupts if it
1422 needs to. Unfortunately, some BIOSes do not -- especially those in
1423 many of the newer IBM Thinkpads. If you experience hangs when you
1424 suspend, try setting this to Y. Otherwise, say N.
1425
1426 config APM_REAL_MODE_POWER_OFF
1427 bool "Use real mode APM BIOS call to power off"
1428 help
1429 Use real mode APM BIOS calls to switch off the computer. This is
1430 a work-around for a number of buggy BIOSes. Switch this option on if
1431 your computer crashes instead of powering off properly.
1432
1433 endif # APM
1434
1435 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1436
1437 source "drivers/cpuidle/Kconfig"
1438
1439 endmenu
1440
1441
1442 menu "Bus options (PCI etc.)"
1443
1444 config PCI
1445 bool "PCI support" if !X86_VISWS && !X86_VSMP
1446 depends on !X86_VOYAGER
1447 default y
1448 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1449 help
1450 Find out whether you have a PCI motherboard. PCI is the name of a
1451 bus system, i.e. the way the CPU talks to the other stuff inside
1452 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1453 VESA. If you have PCI, say Y, otherwise N.
1454
1455 choice
1456 prompt "PCI access mode"
1457 depends on X86_32 && PCI && !X86_VISWS
1458 default PCI_GOANY
1459 ---help---
1460 On PCI systems, the BIOS can be used to detect the PCI devices and
1461 determine their configuration. However, some old PCI motherboards
1462 have BIOS bugs and may crash if this is done. Also, some embedded
1463 PCI-based systems don't have any BIOS at all. Linux can also try to
1464 detect the PCI hardware directly without using the BIOS.
1465
1466 With this option, you can specify how Linux should detect the
1467 PCI devices. If you choose "BIOS", the BIOS will be used,
1468 if you choose "Direct", the BIOS won't be used, and if you
1469 choose "MMConfig", then PCI Express MMCONFIG will be used.
1470 If you choose "Any", the kernel will try MMCONFIG, then the
1471 direct access method and falls back to the BIOS if that doesn't
1472 work. If unsure, go with the default, which is "Any".
1473
1474 config PCI_GOBIOS
1475 bool "BIOS"
1476
1477 config PCI_GOMMCONFIG
1478 bool "MMConfig"
1479
1480 config PCI_GODIRECT
1481 bool "Direct"
1482
1483 config PCI_GOANY
1484 bool "Any"
1485
1486 endchoice
1487
1488 config PCI_BIOS
1489 def_bool y
1490 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1491
1492 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1493 config PCI_DIRECT
1494 def_bool y
1495 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1496
1497 config PCI_MMCONFIG
1498 def_bool y
1499 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1500
1501 config PCI_DOMAINS
1502 def_bool y
1503 depends on PCI
1504
1505 config PCI_MMCONFIG
1506 bool "Support mmconfig PCI config space access"
1507 depends on X86_64 && PCI && ACPI
1508
1509 config DMAR
1510 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1511 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1512 help
1513 DMA remapping (DMAR) devices support enables independent address
1514 translations for Direct Memory Access (DMA) from devices.
1515 These DMA remapping devices are reported via ACPI tables
1516 and include PCI device scope covered by these DMA
1517 remapping devices.
1518
1519 config DMAR_GFX_WA
1520 def_bool y
1521 prompt "Support for Graphics workaround"
1522 depends on DMAR
1523 help
1524 Current Graphics drivers tend to use physical address
1525 for DMA and avoid using DMA APIs. Setting this config
1526 option permits the IOMMU driver to set a unity map for
1527 all the OS-visible memory. Hence the driver can continue
1528 to use physical addresses for DMA.
1529
1530 config DMAR_FLOPPY_WA
1531 def_bool y
1532 depends on DMAR
1533 help
1534 Floppy disk drivers are know to bypass DMA API calls
1535 thereby failing to work when IOMMU is enabled. This
1536 workaround will setup a 1:1 mapping for the first
1537 16M to make floppy (an ISA device) work.
1538
1539 source "drivers/pci/pcie/Kconfig"
1540
1541 source "drivers/pci/Kconfig"
1542
1543 # x86_64 have no ISA slots, but do have ISA-style DMA.
1544 config ISA_DMA_API
1545 def_bool y
1546
1547 if X86_32
1548
1549 config ISA
1550 bool "ISA support"
1551 depends on !(X86_VOYAGER || X86_VISWS)
1552 help
1553 Find out whether you have ISA slots on your motherboard. ISA is the
1554 name of a bus system, i.e. the way the CPU talks to the other stuff
1555 inside your box. Other bus systems are PCI, EISA, MicroChannel
1556 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1557 newer boards don't support it. If you have ISA, say Y, otherwise N.
1558
1559 config EISA
1560 bool "EISA support"
1561 depends on ISA
1562 ---help---
1563 The Extended Industry Standard Architecture (EISA) bus was
1564 developed as an open alternative to the IBM MicroChannel bus.
1565
1566 The EISA bus provided some of the features of the IBM MicroChannel
1567 bus while maintaining backward compatibility with cards made for
1568 the older ISA bus. The EISA bus saw limited use between 1988 and
1569 1995 when it was made obsolete by the PCI bus.
1570
1571 Say Y here if you are building a kernel for an EISA-based machine.
1572
1573 Otherwise, say N.
1574
1575 source "drivers/eisa/Kconfig"
1576
1577 config MCA
1578 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1579 default y if X86_VOYAGER
1580 help
1581 MicroChannel Architecture is found in some IBM PS/2 machines and
1582 laptops. It is a bus system similar to PCI or ISA. See
1583 <file:Documentation/mca.txt> (and especially the web page given
1584 there) before attempting to build an MCA bus kernel.
1585
1586 source "drivers/mca/Kconfig"
1587
1588 config SCx200
1589 tristate "NatSemi SCx200 support"
1590 depends on !X86_VOYAGER
1591 help
1592 This provides basic support for National Semiconductor's
1593 (now AMD's) Geode processors. The driver probes for the
1594 PCI-IDs of several on-chip devices, so its a good dependency
1595 for other scx200_* drivers.
1596
1597 If compiled as a module, the driver is named scx200.
1598
1599 config SCx200HR_TIMER
1600 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1601 depends on SCx200 && GENERIC_TIME
1602 default y
1603 help
1604 This driver provides a clocksource built upon the on-chip
1605 27MHz high-resolution timer. Its also a workaround for
1606 NSC Geode SC-1100's buggy TSC, which loses time when the
1607 processor goes idle (as is done by the scheduler). The
1608 other workaround is idle=poll boot option.
1609
1610 config GEODE_MFGPT_TIMER
1611 def_bool y
1612 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1613 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1614 help
1615 This driver provides a clock event source based on the MFGPT
1616 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1617 MFGPTs have a better resolution and max interval than the
1618 generic PIT, and are suitable for use as high-res timers.
1619
1620 endif # X86_32
1621
1622 config K8_NB
1623 def_bool y
1624 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1625
1626 source "drivers/pcmcia/Kconfig"
1627
1628 source "drivers/pci/hotplug/Kconfig"
1629
1630 endmenu
1631
1632
1633 menu "Executable file formats / Emulations"
1634
1635 source "fs/Kconfig.binfmt"
1636
1637 config IA32_EMULATION
1638 bool "IA32 Emulation"
1639 depends on X86_64
1640 select COMPAT_BINFMT_ELF
1641 help
1642 Include code to run 32-bit programs under a 64-bit kernel. You should
1643 likely turn this on, unless you're 100% sure that you don't have any
1644 32-bit programs left.
1645
1646 config IA32_AOUT
1647 tristate "IA32 a.out support"
1648 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1649 help
1650 Support old a.out binaries in the 32bit emulation.
1651
1652 config COMPAT
1653 def_bool y
1654 depends on IA32_EMULATION
1655
1656 config COMPAT_FOR_U64_ALIGNMENT
1657 def_bool COMPAT
1658 depends on X86_64
1659
1660 config SYSVIPC_COMPAT
1661 def_bool y
1662 depends on X86_64 && COMPAT && SYSVIPC
1663
1664 endmenu
1665
1666
1667 source "net/Kconfig"
1668
1669 source "drivers/Kconfig"
1670
1671 source "drivers/firmware/Kconfig"
1672
1673 source "fs/Kconfig"
1674
1675 source "arch/x86/Kconfig.debug"
1676
1677 source "security/Kconfig"
1678
1679 source "crypto/Kconfig"
1680
1681 source "arch/x86/kvm/Kconfig"
1682
1683 source "lib/Kconfig"
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