Kconfig 61.2 KB
Newer Older
1
# x86 configuration
Sam Ravnborg's avatar
Sam Ravnborg committed
2
3
4
5
mainmenu "Linux Kernel Configuration for x86"

# Select 32 or 64 bit
config 64BIT
6
7
	bool "64-bit kernel" if ARCH = "x86"
	default ARCH = "x86_64"
Sam Ravnborg's avatar
Sam Ravnborg committed
8
9
10
11
12
13
14
15
16
	help
	  Say yes to build a 64-bit kernel - formerly known as x86_64
	  Say no to build a 32-bit kernel - formerly known as i386

config X86_32
	def_bool !64BIT

config X86_64
	def_bool 64BIT
17
18

### Arch settings
19
config X86
20
	def_bool y
21
	select HAVE_AOUT if X86_32
22
	select HAVE_UNSTABLE_SCHED_CLOCK
Sam Ravnborg's avatar
Sam Ravnborg committed
23
	select HAVE_IDE
Mathieu Desnoyers's avatar
Mathieu Desnoyers committed
24
	select HAVE_OPROFILE
25
	select HAVE_IOREMAP_PROT
Mathieu Desnoyers's avatar
Mathieu Desnoyers committed
26
	select HAVE_KPROBES
27
	select ARCH_WANT_OPTIONAL_GPIOLIB
28
	select HAVE_KRETPROBES
29
	select HAVE_FTRACE_MCOUNT_RECORD
30
	select HAVE_DYNAMIC_FTRACE
31
	select HAVE_FUNCTION_TRACER
32
	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
Ingo Molnar's avatar
Ingo Molnar committed
33
	select HAVE_ARCH_KGDB if !X86_VOYAGER
34
	select HAVE_ARCH_TRACEHOOK
35
	select HAVE_GENERIC_DMA_COHERENT if X86_32
36
	select HAVE_EFFICIENT_UNALIGNED_ACCESS
37

38
config ARCH_DEFCONFIG
39
	string
40
41
	default "arch/x86/configs/i386_defconfig" if X86_32
	default "arch/x86/configs/x86_64_defconfig" if X86_64
42

43
config GENERIC_TIME
44
	def_bool y
45
46

config GENERIC_CMOS_UPDATE
47
	def_bool y
48
49

config CLOCKSOURCE_WATCHDOG
50
	def_bool y
51
52

config GENERIC_CLOCKEVENTS
53
	def_bool y
54
55

config GENERIC_CLOCKEVENTS_BROADCAST
56
	def_bool y
57
58
59
	depends on X86_64 || (X86_32 && X86_LOCAL_APIC)

config LOCKDEP_SUPPORT
60
	def_bool y
61
62

config STACKTRACE_SUPPORT
63
	def_bool y
64

65
66
67
config HAVE_LATENCYTOP_SUPPORT
	def_bool y

68
69
70
71
config FAST_CMPXCHG_LOCAL
	bool
	default y

72
config MMU
73
	def_bool y
74
75

config ZONE_DMA
76
	def_bool y
77
78
79
80
81

config SBUS
	bool

config GENERIC_ISA_DMA
82
	def_bool y
83
84

config GENERIC_IOMAP
85
	def_bool y
86
87

config GENERIC_BUG
88
	def_bool y
89
90
91
	depends on BUG

config GENERIC_HWEIGHT
92
	def_bool y
93

94
config GENERIC_GPIO
95
	bool
96

97
config ARCH_MAY_HAVE_PC_FDC
98
	def_bool y
99

100
101
102
103
104
105
config RWSEM_GENERIC_SPINLOCK
	def_bool !X86_XADD

config RWSEM_XCHGADD_ALGORITHM
	def_bool X86_XADD

106
107
108
config ARCH_HAS_CPU_IDLE_WAIT
	def_bool y

109
110
111
config GENERIC_CALIBRATE_DELAY
	def_bool y

112
113
114
115
config GENERIC_TIME_VSYSCALL
	bool
	default X86_64

116
117
118
config ARCH_HAS_CPU_RELAX
	def_bool y

119
120
121
config ARCH_HAS_CACHE_LINE_SIZE
	def_bool y

122
config HAVE_SETUP_PER_CPU_AREA
123
	def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
124

125
126
127
config HAVE_CPUMASK_OF_CPU_MAP
	def_bool X86_64_SMP

128
129
130
131
config ARCH_HIBERNATION_POSSIBLE
	def_bool y
	depends on !SMP || !X86_VOYAGER

Johannes Berg's avatar
Johannes Berg committed
132
133
134
135
config ARCH_SUSPEND_POSSIBLE
	def_bool y
	depends on !X86_VOYAGER

136
137
138
139
140
141
142
143
144
145
146
config ZONE_DMA32
	bool
	default X86_64

config ARCH_POPULATES_NODE_MAP
	def_bool y

config AUDIT_ARCH
	bool
	default X86_64

147
148
149
config ARCH_SUPPORTS_OPTIMIZED_INLINING
	def_bool y

150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
# Use the generic interrupt handling code in kernel/irq/:
config GENERIC_HARDIRQS
	bool
	default y

config GENERIC_IRQ_PROBE
	bool
	default y

config GENERIC_PENDING_IRQ
	bool
	depends on GENERIC_HARDIRQS && SMP
	default y

config X86_SMP
	bool
166
	depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
167
	select USE_GENERIC_SMP_HELPERS
168
169
	default y

170
171
172
173
174
175
176
177
config X86_32_SMP
	def_bool y
	depends on X86_32 && SMP

config X86_64_SMP
	def_bool y
	depends on X86_64 && SMP

178
179
config X86_HT
	bool
180
	depends on SMP
181
	depends on (X86_32 && !X86_VOYAGER) || X86_64
182
183
184
185
	default y

config X86_BIOS_REBOOT
	bool
186
	depends on !X86_VOYAGER
187
188
189
190
	default y

config X86_TRAMPOLINE
	bool
191
	depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
192
193
194
195
	default y

config KTIME_SCALAR
	def_bool X86_32
196
source "init/Kconfig"
197

198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
menu "Processor type and features"

source "kernel/time/Kconfig"

config SMP
	bool "Symmetric multi-processing support"
	---help---
	  This enables support for systems with more than one CPU. If you have
	  a system with only one CPU, like most personal computers, say N. If
	  you have a system with more than one CPU, say Y.

	  If you say N here, the kernel will run on single and multiprocessor
	  machines, but will use only one CPU of a multiprocessor machine. If
	  you say Y here, the kernel will run on many, but not all,
	  singleprocessor machines. On a singleprocessor machine, the kernel
	  will run faster if you say N here.

	  Note that if you say Y here and choose architecture "586" or
	  "Pentium" under "Processor family", the kernel will not work on 486
	  architectures. Similarly, multiprocessor kernels for the "PPro"
	  architecture may not work on all Pentium based boards.

	  People using multiprocessor machines who say Y here should also say
	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
	  Management" code will be disabled if you say Y here.

Adrian Bunk's avatar
Adrian Bunk committed
224
	  See also <file:Documentation/i386/IO-APIC.txt>,
225
226
227
228
229
	  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
	  <http://www.tldp.org/docs.html#howto>.

	  If you don't know what to do here, say N.

230
231
config X86_FIND_SMP_CONFIG
	def_bool y
232
	depends on X86_MPPARSE || X86_VOYAGER
233
234
235
236
237

if ACPI
config X86_MPPARSE
	def_bool y
	bool "Enable MPS table"
238
	depends on X86_LOCAL_APIC
239
240
241
242
243
244
245
246
	help
	  For old smp systems that do not have proper acpi support. Newer systems
	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
endif

if !ACPI
config X86_MPPARSE
	def_bool y
247
	depends on X86_LOCAL_APIC
248
249
endif

250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
choice
	prompt "Subarchitecture Type"
	default X86_PC

config X86_PC
	bool "PC-compatible"
	help
	  Choose this option if your computer is a standard PC or compatible.

config X86_ELAN
	bool "AMD Elan"
	depends on X86_32
	help
	  Select this for an AMD Elan processor.

	  Do not use this option for K6/Athlon/Opteron processors!

	  If unsure, choose "PC-compatible" instead.

config X86_VOYAGER
	bool "Voyager (NCR)"
Ingo Molnar's avatar
Ingo Molnar committed
271
	depends on X86_32 && (SMP || BROKEN) && !PCI
272
273
274
275
276
277
278
279
280
281
	help
	  Voyager is an MCA-based 32-way capable SMP architecture proprietary
	  to NCR Corp.  Machine classes 345x/35xx/4100/51xx are Voyager-based.

	  *** WARNING ***

	  If you do not specifically know you have a Voyager based machine,
	  say N here, otherwise the kernel you build will not be bootable.

config X86_GENERICARCH
282
       bool "Generic architecture"
283
284
	depends on X86_32
       help
285
286
287
288
289
290
291
292
293
          This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
	  subarchitectures.  It is intended for a generic binary kernel.
	  if you select them all, kernel will probe it one by one. and will
	  fallback to default.

if X86_GENERICARCH

config X86_NUMAQ
	bool "NUMAQ (IBM/Sequent)"
294
	depends on SMP && X86_32 && PCI && X86_MPPARSE
295
296
297
298
299
300
301
302
303
304
305
306
307
308
	select NUMA
	help
	  This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
	  NUMA multiquad box. This changes the way that processors are
	  bootstrapped, and uses Clustered Logical APIC addressing mode instead
	  of Flat Logical.  You will need a new lynxer.elf file to flash your
	  firmware with - send email to <Martin.Bligh@us.ibm.com>.

config X86_SUMMIT
	bool "Summit/EXA (IBM x440)"
	depends on X86_32 && SMP
	help
	  This option is needed for IBM systems that use the Summit/EXA chipset.
	  In particular, it is needed for the x440.
309
310
311
312
313
314
315

config X86_ES7000
	bool "Support for Unisys ES7000 IA32 series"
	depends on X86_32 && SMP
	help
	  Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
	  supposed to run on an IA32-based Unisys ES7000 system.
316
317
318
319
320
321
322
323
324

config X86_BIGSMP
	bool "Support for big SMP systems with more than 8 CPUs"
	depends on X86_32 && SMP
	help
	  This option is needed for the systems that have more than 8 CPUs
	  and if the system is not of any sub-arch type above.

endif
325
326
327

config X86_VSMP
	bool "Support for ScaleMP vSMP"
328
	select PARAVIRT
Ingo Molnar's avatar
Ingo Molnar committed
329
	depends on X86_64 && PCI
330
	help
331
332
333
334
335
336
	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
	  supposed to run on these EM64T-based machines.  Only choose this option
	  if you have one of these machines.

endchoice

337
338
config X86_VISWS
	bool "SGI 320/540 (Visual Workstation)"
339
	depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
340
341
342
343
344
345
346
347
348
	help
	  The SGI Visual Workstation series is an IA32-based workstation
	  based on SGI systems chips with some legacy PC hardware attached.

	  Say Y here to create a kernel to run on the SGI 320 or 540.

	  A kernel compiled for the Visual Workstation will run on general
	  PCs as well. See <file:Documentation/sgi-visws.txt> for details.

349
350
351
352
353
354
355
356
357
358
config X86_RDC321X
	bool "RDC R-321x SoC"
	depends on X86_32
	select M486
	select X86_REBOOTFIXUPS
	help
	  This option is needed for RDC R-321x system-on-chip, also known
	  as R-8610-(G).
	  If you don't have one of these chips, you should say N here.

359
config SCHED_NO_NO_OMIT_FRAME_POINTER
360
361
	def_bool y
	prompt "Single-depth WCHAN output"
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
	depends on X86_32
	help
	  Calculate simpler /proc/<PID>/wchan values. If this option
	  is disabled then wchan values will recurse back to the
	  caller function. This provides more accurate wchan values,
	  at the expense of slightly more scheduling overhead.

	  If in doubt, say "Y".

menuconfig PARAVIRT_GUEST
	bool "Paravirtualized guest support"
	help
	  Say Y here to get to see options related to running Linux under
	  various hypervisors.  This option alone does not add any kernel code.

	  If you say N, all options in this submenu will be skipped and disabled.

if PARAVIRT_GUEST

source "arch/x86/xen/Kconfig"

config VMI
	bool "VMI Guest support"
	select PARAVIRT
386
	depends on X86_32
387
	depends on !X86_VOYAGER
388
389
390
391
392
393
	help
	  VMI provides a paravirtualized interface to the VMware ESX server
	  (it could be used by other hypervisors in theory too, but is not
	  at the moment), by linking the kernel to a GPL-ed ROM module
	  provided by the hypervisor.

394
395
396
config KVM_CLOCK
	bool "KVM paravirtualized clock"
	select PARAVIRT
397
	select PARAVIRT_CLOCK
398
	depends on !X86_VOYAGER
399
400
401
402
403
404
405
	help
	  Turning on this option will allow you to run a paravirtualized clock
	  when running over the KVM hypervisor. Instead of relying on a PIT
	  (or probably other) emulation by the underlying device model, the host
	  provides the guest with timing infrastructure such as time of day, and
	  system time

406
407
408
config KVM_GUEST
	bool "KVM Guest support"
	select PARAVIRT
409
	depends on !X86_VOYAGER
410
411
412
413
	help
	 This option enables various optimizations for running under the KVM
	 hypervisor.

414
415
source "arch/x86/lguest/Kconfig"

416
417
config PARAVIRT
	bool "Enable paravirtualization code"
418
	depends on !X86_VOYAGER
419
420
421
422
423
424
	help
	  This changes the kernel so it can modify itself when it is run
	  under a hypervisor, potentially improving performance significantly
	  over full virtualization.  However, when run without a hypervisor
	  the kernel is theoretically slower and slightly larger.

425
426
427
428
config PARAVIRT_CLOCK
	bool
	default n

429
430
endif

431
432
433
434
435
436
437
config PARAVIRT_DEBUG
       bool "paravirt-ops debugging"
       depends on PARAVIRT && DEBUG_KERNEL
       help
         Enable to debug paravirt_ops internals.  Specifically, BUG if
	 a paravirt_op is missing when it is called.

438
439
config MEMTEST
	bool "Memtest"
Yinghai Lu's avatar
Yinghai Lu committed
440
441
	help
	  This option adds a kernel parameter 'memtest', which allows memtest
442
443
444
445
446
	  to be set.
		memtest=0, mean disabled; -- default
		memtest=1, mean do 1 test pattern;
		...
		memtest=4, mean do 4 test patterns.
Thomas Gleixner's avatar
Thomas Gleixner committed
447
	  If you are unsure how to answer this question, answer N.
Yinghai Lu's avatar
Yinghai Lu committed
448

449
config X86_SUMMIT_NUMA
450
	def_bool y
451
	depends on X86_32 && NUMA && X86_GENERICARCH
452
453

config X86_CYCLONE_TIMER
454
	def_bool y
455
	depends on X86_GENERICARCH
456
457

config ES7000_CLUSTERED_APIC
458
	def_bool y
459
460
461
462
463
	depends on SMP && X86_ES7000 && MPENTIUMIII

source "arch/x86/Kconfig.cpu"

config HPET_TIMER
464
	def_bool X86_64
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
	prompt "HPET Timer Support" if X86_32
	help
         Use the IA-PC HPET (High Precision Event Timer) to manage
         time in preference to the PIT and RTC, if a HPET is
         present.
         HPET is the next generation timer replacing legacy 8254s.
         The HPET provides a stable time base on SMP
         systems, unlike the TSC, but it is more expensive to access,
         as it is off-chip.  You can find the HPET spec at
         <http://www.intel.com/hardwaredesign/hpetspec.htm>.

         You can safely choose Y here.  However, HPET will only be
         activated if the platform and the BIOS support this feature.
         Otherwise the 8254 will be used for timing services.

         Choose N to continue using the legacy 8254 timer.

config HPET_EMULATE_RTC
483
	def_bool y
484
	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
485
486
487

# Mark as embedded because too many people got it wrong.
# The code disables itself when not needed.
488
489
490
491
492
493
494
495
496
config DMI
	default y
	bool "Enable DMI scanning" if EMBEDDED
	help
	  Enabled scanning of DMI to identify machine quirks. Say Y
	  here unless you have verified that your setup is not
	  affected by entries in the DMI blacklist. Required by PNP
	  BIOS code.

497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
config GART_IOMMU
	bool "GART IOMMU support" if EMBEDDED
	default y
	select SWIOTLB
	select AGP
	depends on X86_64 && PCI
	help
	  Support for full DMA access of devices with 32bit memory access only
	  on systems with more than 3GB. This is usually needed for USB,
	  sound, many IDE/SATA chipsets and some other devices.
	  Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
	  based hardware IOMMU and a software bounce buffer based IOMMU used
	  on Intel systems and as fallback.
	  The code is only active when needed (enough memory and limited
	  device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
	  too.

config CALGARY_IOMMU
	bool "IBM Calgary IOMMU support"
	select SWIOTLB
	depends on X86_64 && PCI && EXPERIMENTAL
	help
	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
	  systems. Needed to run systems with more than 3GB of memory
	  properly with 32-bit PCI devices that do not support DAC
	  (Double Address Cycle). Calgary also supports bus level
	  isolation, where all DMAs pass through the IOMMU.  This
	  prevents them from going anywhere except their intended
	  destination. This catches hard-to-find kernel bugs and
	  mis-behaving drivers and devices that do not use the DMA-API
	  properly to set up their DMA buffers.  The IOMMU can be
	  turned off at boot time with the iommu=off parameter.
	  Normally the kernel will make the right choice by itself.
	  If unsure, say Y.

config CALGARY_IOMMU_ENABLED_BY_DEFAULT
533
534
	def_bool y
	prompt "Should Calgary be enabled by default?"
535
536
537
538
539
540
541
542
	depends on CALGARY_IOMMU
	help
	  Should Calgary be enabled by default? if you choose 'y', Calgary
	  will be used (if it exists). If you choose 'n', Calgary will not be
	  used even if it exists. If you choose 'n' and would like to use
	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
	  If unsure, say Y.

543
544
config AMD_IOMMU
	bool "AMD IOMMU support"
Ingo Molnar's avatar
Ingo Molnar committed
545
	select SWIOTLB
546
	select PCI_MSI
Ingo Molnar's avatar
Ingo Molnar committed
547
	depends on X86_64 && PCI && ACPI
548
	help
549
550
551
552
553
554
555
556
557
	  With this option you can enable support for AMD IOMMU hardware in
	  your system. An IOMMU is a hardware component which provides
	  remapping of DMA memory accesses from devices. With an AMD IOMMU you
	  can isolate the the DMA memory of different devices and protect the
	  system from misbehaving device drivers or hardware.

	  You can find out if your system has an AMD IOMMU if you look into
	  your BIOS for an option to enable it or if you have an IVRS ACPI
	  table.
558

559
560
561
562
563
564
565
566
567
568
# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
	bool
	help
	  Support for software bounce buffers used on x86-64 systems
	  which don't have a hardware IOMMU (e.g. the current generation
	  of Intel's x86-64 CPUs). Using this PCI devices which can only
	  access 32-bits of memory can be used on systems with more than
	  3 GB of memory. If unsure, say Y.

569
config IOMMU_HELPER
570
	def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
571

572
573
config MAXSMP
	bool "Configure Maximum number of SMP Processors and NUMA Nodes"
574
	depends on X86_64 && SMP && BROKEN
575
576
577
578
	default n
	help
	  Configure maximum number of CPUS and NUMA Nodes for this architecture.
	  If unsure, say N.
579
580

config NR_CPUS
581
582
	int "Maximum number of CPUs (2-512)" if !MAXSMP
	range 2 512
583
	depends on SMP
584
	default "4096" if MAXSMP
585
586
587
588
	default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
	default "8"
	help
	  This allows you to specify the maximum number of CPUs which this
589
	  kernel will support.  The maximum supported value is 512 and the
590
591
592
593
594
595
596
	  minimum value which makes sense is 2.

	  This is purely to save memory - each supported CPU adds
	  approximately eight kilobytes to the kernel image.

config SCHED_SMT
	bool "SMT (Hyperthreading) scheduler support"
597
	depends on X86_HT
598
599
600
601
602
603
604
	help
	  SMT scheduler support improves the CPU scheduler's decision making
	  when dealing with Intel Pentium 4 chips with HyperThreading at a
	  cost of slightly increased overhead in some places. If unsure say
	  N here.

config SCHED_MC
605
606
	def_bool y
	prompt "Multi-core scheduler support"
607
	depends on X86_HT
608
609
610
611
612
613
614
615
616
	help
	  Multi-core scheduler support improves the CPU scheduler's decision
	  making when dealing with multi-core CPU chips at a cost of slightly
	  increased overhead in some places. If unsure say N here.

source "kernel/Kconfig.preempt"

config X86_UP_APIC
	bool "Local APIC support on uniprocessors"
617
	depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
	help
	  A local APIC (Advanced Programmable Interrupt Controller) is an
	  integrated interrupt controller in the CPU. If you have a single-CPU
	  system which has a processor with a local APIC, you can say Y here to
	  enable and use it. If you say Y here even though your machine doesn't
	  have a local APIC, then the kernel will still run with no slowdown at
	  all. The local APIC supports CPU-generated self-interrupts (timer,
	  performance counters), and the NMI watchdog which detects hard
	  lockups.

config X86_UP_IOAPIC
	bool "IO-APIC support on uniprocessors"
	depends on X86_UP_APIC
	help
	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
	  SMP-capable replacement for PC-style interrupt controllers. Most
	  SMP systems and many recent uniprocessor systems have one.

	  If you have a single-CPU system with an IO-APIC, you can say Y here
	  to use it. If you say Y here even though your machine doesn't have
	  an IO-APIC, then the kernel will still run with no slowdown at all.

config X86_LOCAL_APIC
641
	def_bool y
642
	depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
643
644

config X86_IO_APIC
645
	def_bool y
646
	depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
647
648

config X86_VISWS_APIC
649
	def_bool y
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
	depends on X86_32 && X86_VISWS

config X86_MCE
	bool "Machine Check Exception"
	depends on !X86_VOYAGER
	---help---
	  Machine Check Exception support allows the processor to notify the
	  kernel if it detects a problem (e.g. overheating, component failure).
	  The action the kernel takes depends on the severity of the problem,
	  ranging from a warning message on the console, to halting the machine.
	  Your processor must be a Pentium or newer to support this - check the
	  flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
	  have a design flaw which leads to false MCE events - hence MCE is
	  disabled on all P5 processors, unless explicitly enabled with "mce"
	  as a boot argument.  Similarly, if MCE is built in and creates a
	  problem on some new non-standard machine, you can boot with "nomce"
	  to disable it.  MCE support simply ignores non-MCE processors like
	  the 386 and 486, so nearly everyone can say Y here.

config X86_MCE_INTEL
670
671
	def_bool y
	prompt "Intel MCE features"
672
673
674
675
676
677
	depends on X86_64 && X86_MCE && X86_LOCAL_APIC
	help
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config X86_MCE_AMD
678
679
	def_bool y
	prompt "AMD MCE features"
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
	depends on X86_64 && X86_MCE && X86_LOCAL_APIC
	help
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

config X86_MCE_NONFATAL
	tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
	depends on X86_32 && X86_MCE
	help
	  Enabling this feature starts a timer that triggers every 5 seconds which
	  will look at the machine check registers to see if anything happened.
	  Non-fatal problems automatically get corrected (but still logged).
	  Disable this if you don't want to see these messages.
	  Seeing the messages this option prints out may be indicative of dying
	  or out-of-spec (ie, overclocked) hardware.
	  This option only does something on certain CPUs.
	  (AMD Athlon/Duron and Intel Pentium 4)

config X86_MCE_P4THERMAL
	bool "check for P4 thermal throttling interrupt."
700
	depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
	help
	  Enabling this feature will cause a message to be printed when the P4
	  enters thermal throttling.

config VM86
	bool "Enable VM86 support" if EMBEDDED
	default y
	depends on X86_32
	help
          This option is required by programs like DOSEMU to run 16-bit legacy
	  code on X86 processors. It also may be needed by software like
          XFree86 to initialize some video cards via BIOS. Disabling this
          option saves about 6k.

config TOSHIBA
	tristate "Toshiba Laptop support"
	depends on X86_32
	---help---
	  This adds a driver to safely access the System Management Mode of
	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
	  not work on models with a Phoenix BIOS. The System Management Mode
	  is used to set the BIOS and power saving options on Toshiba portables.

	  For information on utilities to make use of this driver see the
	  Toshiba Linux utilities web site at:
	  <http://www.buzzard.org.uk/toshiba/>.

	  Say Y if you intend to run this kernel on a Toshiba portable.
	  Say N otherwise.

config I8K
	tristate "Dell laptop support"
	---help---
	  This adds a driver to safely access the System Management Mode
	  of the CPU on the Dell Inspiron 8000. The System Management Mode
	  is used to read cpu temperature and cooling fan status and to
	  control the fans on the I8K portables.

	  This driver has been tested only on the Inspiron 8000 but it may
	  also work with other Dell laptops. You can force loading on other
	  models by passing the parameter `force=1' to the module. Use at
	  your own risk.

	  For information on utilities to make use of this driver see the
	  I8K Linux utilities web site at:
	  <http://people.debian.org/~dz/i8k/>

	  Say Y if you intend to run this kernel on a Dell Inspiron 8000.
	  Say N otherwise.

config X86_REBOOTFIXUPS
752
753
	bool "Enable X86 board specific fixups for reboot"
	depends on X86_32
754
755
756
757
758
759
760
761
	---help---
	  This enables chipset and/or board specific fixups to be done
	  in order to get reboot to work correctly. This is only needed on
	  some combinations of hardware and BIOS. The symptom, for which
	  this config is intended, is when reboot ends with a stalled/hung
	  system.

	  Currently, the only fixup is for the Geode machines using
762
	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
763
764
765
766
767
768

	  Say Y if you want to enable the fixup. Currently, it's safe to
	  enable this option even if you don't need it.
	  Say N otherwise.

config MICROCODE
Peter Oruba's avatar
Peter Oruba committed
769
	tristate "/dev/cpu/microcode - microcode support"
770
771
772
	select FW_LOADER
	---help---
	  If you say Y here, you will be able to update the microcode on
773
774
775
776
777
778
	  certain Intel and AMD processors. The Intel support is for the
	  IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
	  Pentium 4, Xeon etc. The AMD support is for family 0x10 and
	  0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
	  You will obviously need the actual microcode binary data itself
	  which is not shipped with the Linux kernel.
779

Peter Oruba's avatar
Peter Oruba committed
780
781
	  This option selects the general module only, you need to select
	  at least one vendor specific module as well.
782
783
784
785

	  To compile this driver as a module, choose M here: the
	  module will be called microcode.

Peter Oruba's avatar
Peter Oruba committed
786
config MICROCODE_INTEL
787
       bool "Intel microcode patch loading support"
Peter Oruba's avatar
Peter Oruba committed
788
789
790
791
792
793
794
795
796
797
798
       depends on MICROCODE
       default MICROCODE
       select FW_LOADER
       --help---
         This options enables microcode patch loading support for Intel
         processors.

         For latest news and information on obtaining all the required
         Intel ingredients for this driver, check:
         <http://www.urbanmyth.org/microcode/>.

799
config MICROCODE_AMD
800
       bool "AMD microcode patch loading support"
801
802
803
804
805
806
       depends on MICROCODE
       select FW_LOADER
       --help---
         If you select this option, microcode patch loading support for AMD
	 processors will be enabled.

Peter Oruba's avatar
Peter Oruba committed
807
   config MICROCODE_OLD_INTERFACE
808
	def_bool y
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
	depends on MICROCODE

config X86_MSR
	tristate "/dev/cpu/*/msr - Model-specific register support"
	help
	  This device gives privileged processes access to the x86
	  Model-Specific Registers (MSRs).  It is a character device with
	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
	  MSR accesses are directed to a specific CPU on multi-processor
	  systems.

config X86_CPUID
	tristate "/dev/cpu/*/cpuid - CPU information support"
	help
	  This device gives processes access to the x86 CPUID instruction to
	  be executed on a specific processor.  It is a character device
	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
	  /dev/cpu/31/cpuid.

choice
	prompt "High Memory Support"
	default HIGHMEM4G if !X86_NUMAQ
	default HIGHMEM64G if X86_NUMAQ
	depends on X86_32

config NOHIGHMEM
	bool "off"
	depends on !X86_NUMAQ
	---help---
	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
	  However, the address space of 32-bit x86 processors is only 4
	  Gigabytes large. That means that, if you have a large amount of
	  physical memory, not all of it can be "permanently mapped" by the
	  kernel. The physical memory that's not permanently mapped is called
	  "high memory".

	  If you are compiling a kernel which will never run on a machine with
	  more than 1 Gigabyte total physical RAM, answer "off" here (default
	  choice and suitable for most users). This will result in a "3GB/1GB"
	  split: 3GB are mapped so that each process sees a 3GB virtual memory
	  space and the remaining part of the 4GB virtual memory space is used
	  by the kernel to permanently map as much physical memory as
	  possible.

	  If the machine has between 1 and 4 Gigabytes physical RAM, then
	  answer "4GB" here.

	  If more than 4 Gigabytes is used then answer "64GB" here. This
	  selection turns Intel PAE (Physical Address Extension) mode on.
	  PAE implements 3-level paging on IA32 processors. PAE is fully
	  supported by Linux, PAE mode is implemented on all recent Intel
	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
	  then the kernel will not boot on CPUs that don't support PAE!

	  The actual amount of total physical memory will either be
	  auto detected or can be forced by using a kernel command line option
	  such as "mem=256M". (Try "man bootparam" or see the documentation of
	  your boot loader (lilo or loadlin) about how to pass options to the
	  kernel at boot time.)

	  If unsure, say "off".

config HIGHMEM4G
	bool "4GB"
	depends on !X86_NUMAQ
	help
	  Select this if you have a 32-bit processor and between 1 and 4
	  gigabytes of physical RAM.

config HIGHMEM64G
	bool "64GB"
	depends on !M386 && !M486
	select X86_PAE
	help
	  Select this if you have a 32-bit processor and more than 4
	  gigabytes of physical RAM.

endchoice

choice
	depends on EXPERIMENTAL
	prompt "Memory split" if EMBEDDED
	default VMSPLIT_3G
	depends on X86_32
	help
	  Select the desired split between kernel and user memory.

	  If the address range available to the kernel is less than the
	  physical memory installed, the remaining memory will be available
	  as "high memory". Accessing high memory is a little more costly
	  than low memory, as it needs to be mapped into the kernel first.
	  Note that increasing the kernel address space limits the range
	  available to user programs, making the address space there
	  tighter.  Selecting anything other than the default 3G/1G split
	  will also likely make your kernel incompatible with binary-only
	  kernel modules.

	  If you are not absolutely sure what you are doing, leave this
	  option alone!

	config VMSPLIT_3G
		bool "3G/1G user/kernel split"
	config VMSPLIT_3G_OPT
		depends on !X86_PAE
		bool "3G/1G user/kernel split (for full 1G low memory)"
	config VMSPLIT_2G
		bool "2G/2G user/kernel split"
	config VMSPLIT_2G_OPT
		depends on !X86_PAE
		bool "2G/2G user/kernel split (for full 2G low memory)"
	config VMSPLIT_1G
		bool "1G/3G user/kernel split"
endchoice

config PAGE_OFFSET
	hex
	default 0xB0000000 if VMSPLIT_3G_OPT
	default 0x80000000 if VMSPLIT_2G
	default 0x78000000 if VMSPLIT_2G_OPT
	default 0x40000000 if VMSPLIT_1G
	default 0xC0000000
	depends on X86_32

config HIGHMEM
933
	def_bool y
934
935
936
	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)

config X86_PAE
937
	bool "PAE (Physical Address Extension) Support"
938
939
940
941
942
943
944
	depends on X86_32 && !HIGHMEM4G
	help
	  PAE is required for NX support, and furthermore enables
	  larger swapspace support for non-overcommit purposes. It
	  has the cost of more pagetable lookup overhead, and also
	  consumes more pagetable space per process.

945
946
947
config ARCH_PHYS_ADDR_T_64BIT
       def_bool X86_64 || X86_PAE

948
949
950
951
# Common NUMA Features
config NUMA
	bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
	depends on SMP
952
	depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
953
	default n if X86_PC
954
	default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
955
956
957
958
959
960
	help
	  Enable NUMA (Non Uniform Memory Access) support.
	  The kernel will try to allocate memory used by a CPU on the
	  local memory controller of the CPU and add some more
	  NUMA awareness to the kernel.

961
	  For 32-bit this is currently highly experimental and should be only
962
	  used for kernel development. It might also cause boot failures.
963
	  For 64-bit this is recommended on all multiprocessor Opteron systems.
964
965
966
967
968
969
970
	  If the system is EM64T, you should say N unless your system is
	  EM64T NUMA.

comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
	depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)

config K8_NUMA
971
972
973
974
	def_bool y
	prompt "Old style AMD Opteron NUMA detection"
	depends on X86_64 && NUMA && PCI
	help
975
976
977
978
979
980
981
	 Enable K8 NUMA node topology detection.  You should say Y here if
	 you have a multi processor AMD K8 system. This uses an old
	 method to read the NUMA configuration directly from the builtin
	 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
	 instead, which also takes priority if both are compiled in.

config X86_64_ACPI_NUMA
982
983
	def_bool y
	prompt "ACPI NUMA detection"
984
985
986
987
988
	depends on X86_64 && NUMA && ACPI && PCI
	select ACPI_NUMA
	help
	  Enable ACPI SRAT based node topology detection.

989
990
991
992
993
994
995
996
997
# Some NUMA nodes have memory ranges that span
# other nodes.  Even though a pfn is valid and
# between a node's start and end pfns, it may not
# reside on that node.  See memmap_init_zone()
# for details.
config NODES_SPAN_OTHER_NODES
	def_bool y
	depends on X86_64_ACPI_NUMA

998
999
1000
1001
1002
1003
1004
1005
config NUMA_EMU
	bool "NUMA emulation"
	depends on X86_64 && NUMA
	help
	  Enable NUMA emulation. A flat machine will be split
	  into virtual nodes when booted with "numa=fake=N", where N is the
	  number of nodes. This is only useful for debugging.

1006
config NODES_SHIFT
1007
	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1008
	range 1 9   if X86_64
1009
	default "9" if MAXSMP
1010
1011
1012
1013
	default "6" if X86_64
	default "4" if X86_NUMAQ
	default "3"
	depends on NEED_MULTIPLE_NODES
1014
1015
1016
	help
	  Specify the maximum number of NUMA Nodes available on the target
	  system.  Increases memory reserved to accomodate various tables.
1017
1018

config HAVE_ARCH_BOOTMEM_NODE
1019
	def_bool y
1020
1021
1022
	depends on X86_32 && NUMA

config ARCH_HAVE_MEMORY_PRESENT
1023
	def_bool y
1024
1025
1026
	depends on X86_32 && DISCONTIGMEM

config NEED_NODE_MEMMAP_SIZE
1027
	def_bool y
1028
1029
1030
	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)

config HAVE_ARCH_ALLOC_REMAP
1031
	def_bool y
1032
1033
1034
1035
	depends on X86_32 && NUMA

config ARCH_FLATMEM_ENABLE
	def_bool y
Jeff Chua's avatar
Jeff Chua committed
1036
	depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1037
1038
1039

config ARCH_DISCONTIGMEM_ENABLE
	def_bool y
1040
	depends on NUMA && X86_32
1041
1042
1043

config ARCH_DISCONTIGMEM_DEFAULT
	def_bool y
1044
1045
1046
1047
1048
	depends on NUMA && X86_32

config ARCH_SPARSEMEM_DEFAULT
	def_bool y
	depends on X86_64
1049
1050
1051

config ARCH_SPARSEMEM_ENABLE
	def_bool y
Jeff Chua's avatar
Jeff Chua committed
1052
	depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1053
1054
1055
1056
1057
	select SPARSEMEM_STATIC if X86_32
	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

config ARCH_SELECT_MEMORY_MODEL
	def_bool y
1058
	depends on ARCH_SPARSEMEM_ENABLE
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074

config ARCH_MEMORY_PROBE
	def_bool X86_64
	depends on MEMORY_HOTPLUG

source "mm/Kconfig"

config HIGHPTE
	bool "Allocate 3rd-level pagetables from highmem"
	depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
	help
	  The VM uses one page table entry for each page of physical memory.
	  For systems with a lot of RAM, this can be wasteful of precious
	  low memory.  Setting this option will put user-space page table
	  entries in high memory.

1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
config X86_CHECK_BIOS_CORRUPTION
        bool "Check for low memory corruption"
	help
	 Periodically check for memory corruption in low memory, which
	 is suspected to be caused by BIOS.  Even when enabled in the
	 configuration, it is disabled at runtime.  Enable it by
	 setting "memory_corruption_check=1" on the kernel command
	 line.  By default it scans the low 64k of memory every 60
	 seconds; see the memory_corruption_check_size and
	 memory_corruption_check_period parameters in
	 Documentation/kernel-parameters.txt to adjust this.

	 When enabled with the default parameters, this option has
	 almost no overhead, as it reserves a relatively small amount
	 of memory and scans it infrequently.  It both detects corruption
	 and prevents it from affecting the running system.

	 It is, however, intended as a diagnostic tool; if repeatable
	 BIOS-originated corruption always affects the same memory,
	 you can use memmap= to prevent the kernel from using that
	 memory.

1097
1098
1099
1100
1101
1102
1103
1104
config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
        bool "Set the default setting of memory_corruption_check"
	depends on X86_CHECK_BIOS_CORRUPTION
	default y
	help
	 Set whether the default state of memory_corruption_check is
	 on or off.

Ingo Molnar's avatar
Ingo Molnar committed
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
config X86_RESERVE_LOW_64K
        bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
	default y
	help
	 Reserve the first 64K of physical RAM on BIOSes that are known
	 to potentially corrupt that memory range. A numbers of BIOSes are
	 known to utilize this area during suspend/resume, so it must not
	 be used by the kernel.

	 Set this to N if you are absolutely sure that you trust the BIOS
	 to get all its memory reservations and usages right.

	 If you have doubts about the BIOS (e.g. suspend/resume does not
	 work or there's kernel crashes after certain hardware hotplug
	 events) and it's not AMI or Phoenix, then you might want to enable
	 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
	 corruption patterns.

	 Say Y if unsure.

1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
config MATH_EMULATION
	bool
	prompt "Math emulation" if X86_32
	---help---
	  Linux can emulate a math coprocessor (used for floating point
	  operations) if you don't have one. 486DX and Pentium processors have
	  a math coprocessor built in, 486SX and 386 do not, unless you added
	  a 487DX or 387, respectively. (The messages during boot time can
	  give you some hints here ["man dmesg"].) Everyone needs either a
	  coprocessor or this emulation.

	  If you don't have a math coprocessor, you need to say Y here; if you
	  say Y here even though you have a coprocessor, the coprocessor will
	  be used nevertheless. (This behavior can be changed with the kernel
	  command line option "no387", which comes handy if your coprocessor
	  is broken. Try "man bootparam" or see the documentation of your boot
	  loader (lilo or loadlin) about how to pass options to the kernel at
	  boot time.) This means that it is a good idea to say Y here if you
	  intend to use this kernel on different machines.

	  More information about the internals of the Linux math coprocessor
	  emulation can be found in <file:arch/x86/math-emu/README>.

	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
	  kernel, it won't hurt.

config MTRR
	bool "MTRR (Memory Type Range Register) support"
	---help---
	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
	  the Memory Type Range Registers (MTRRs) may be used to control
	  processor access to memory ranges. This is most useful if you have
	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
	  allows bus write transfers to be combined into a larger transfer
	  before bursting over the PCI/AGP bus. This can increase performance
	  of image write operations 2.5 times or more. Saying Y here creates a
	  /proc/mtrr file which may be used to manipulate your processor's
	  MTRRs. Typically the X server should use this.

	  This code has a reasonably generic interface so that similar
	  control registers on other processors can be easily supported
	  as well:

	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
	  Registers (ARRs) which provide a similar functionality to MTRRs. For
	  these, the ARRs are used to emulate the MTRRs.
	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
	  write-combining. All of these processors are supported by this code
	  and it makes sense to say Y here if you have one of them.

	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
	  can lead to all sorts of problems, so it's good to say Y here.

	  You can safely say Y even if your machine doesn't have MTRRs, you'll
	  just add about 9 KB to your kernel.

1183
	  See <file:Documentation/x86/mtrr.txt> for more information.
1184

1185
config MTRR_SANITIZER
1186
	def_bool y
1187
1188
1189
	prompt "MTRR cleanup support"
	depends on MTRR
	help
Thomas Gleixner's avatar
Thomas Gleixner committed
1190
1191
	  Convert MTRR layout from continuous to discrete, so X drivers can
	  add writeback entries.
1192

Thomas Gleixner's avatar
Thomas Gleixner committed
1193
1194
1195
	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
	  The largest mtrr entry size for a continous block can be set with
	  mtrr_chunk_size.
1196

1197
	  If unsure, say Y.
1198
1199

config MTRR_SANITIZER_ENABLE_DEFAULT
1200
1201
1202
	int "MTRR cleanup enable value (0-1)"
	range 0 1
	default "0"
1203
1204
	depends on MTRR_SANITIZER
	help
1205
	  Enable mtrr cleanup default value
1206

1207
1208
1209
1210
1211
1212
1213
config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
	int "MTRR cleanup spare reg num (0-7)"
	range 0 7
	default "1"
	depends on MTRR_SANITIZER
	help
	  mtrr cleanup spare entries default, it can be changed via
Thomas Gleixner's avatar
Thomas Gleixner committed
1214
	  mtrr_spare_reg_nr=N on the kernel command line.
1215

1216
config X86_PAT
1217
	bool
1218
	prompt "x86 PAT support"
1219
	depends on MTRR
1220
1221
	help
	  Use PAT attributes to setup page level cache control.
1222

1223
1224
1225
1226
	  PATs are the modern equivalents of MTRRs and are much more
	  flexible than MTRRs.

	  Say N here if you see bootup problems (boot crash, boot hang,
1227
	  spontaneous reboots) or a non-working video driver.
1228
1229
1230

	  If unsure, say Y.

1231
config EFI
1232
	bool "EFI runtime service support"
Huang, Ying's avatar
Huang, Ying committed
1233
	depends on ACPI
1234
	---help---
1235
	This enables the kernel to use EFI runtime services that are
1236
1237
	available (such as the EFI variable services).

1238
1239
1240
1241
1242
1243
	This option is only useful on systems that have EFI firmware.
  	In addition, you should use the latest ELILO loader available
  	at <http://elilo.sourceforge.net> in order to take advantage
  	of EFI runtime services. However, even with this option, the
  	resultant kernel should continue to boot on existing non-EFI
  	platforms.
1244
1245

config IRQBALANCE
1246
1247
	def_bool y
	prompt "Enable kernel irq balancing"
1248
1249
1250
1251
1252
1253
	depends on X86_32 && SMP && X86_IO_APIC
	help
	  The default yes will allow the kernel to do irq load balancing.
	  Saying no will keep the kernel from doing irq load balancing.

config SECCOMP
1254
1255
	def_bool y
	prompt "Enable seccomp to safely compute untrusted bytecode"
1256
1257
1258
1259
1260
1261
1262
	help
	  This kernel feature is useful for number crunching applications
	  that may need to compute untrusted bytecode during their
	  execution. By using pipes or other transports made available to
	  the process as file descriptors supporting the read/write
	  syscalls, it's possible to isolate those applications in
	  their own address space using seccomp. Once seccomp is
1263
	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1264
1265
1266
1267
1268
1269
1270
	  and the task is only allowed to execute a few safe syscalls
	  defined by each seccomp mode.

	  If unsure, say Y. Only embedded should say N here.

config CC_STACKPROTECTOR
	bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1271
	depends on X86_64 && EXPERIMENTAL && BROKEN
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
	help
         This option turns on the -fstack-protector GCC feature. This
	  feature puts, at the beginning of critical functions, a canary
	  value on the stack just before the return address, and validates
	  the value just before actually returning.  Stack based buffer
	  overflows (that need to overwrite this return address) now also
	  overwrite the canary, which gets detected and the attack is then
	  neutralized via a kernel panic.

	  This feature requires gcc version 4.2 or above, or a distribution
	  gcc with the feature backported. Older versions are automatically
	  detected and for those versions, this configuration option is ignored.

config CC_STACKPROTECTOR_ALL
	bool "Use stack-protector for all functions"
	depends on CC_STACKPROTECTOR
	help
	  Normally, GCC only inserts the canary value protection for
	  functions that use large-ish on-stack buffers. By enabling
	  this option, GCC will be asked to do this for ALL functions.

source kernel/Kconfig.hz

config KEXEC
	bool "kexec system call"
Ingo Molnar's avatar
Ingo Molnar committed
1297
	depends on X86_BIOS_REBOOT
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
	help
	  kexec is a system call that implements the ability to shutdown your
	  current kernel, and to start another kernel.  It is like a reboot
	  but it is independent of the system firmware.   And like a reboot
	  you can start any kernel with it, not just Linux.

	  The name comes from the similarity to the exec system call.

	  It is an ongoing process to be certain the hardware in a machine
	  is properly shutdown, so do not be surprised if this code does not
	  initially work for you.  It may help to enable device hotplugging
	  support.  As of this writing the exact hardware interface is
	  strongly in flux, so no good recommendation can be made.

config CRASH_DUMP
1313
	bool "kernel crash dumps"
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
	depends on X86_64 || (X86_32 && HIGHMEM)
	help
	  Generate crash dump after being started by kexec.
	  This should be normally only set in special crash dump kernels
	  which are loaded in the main kernel with kexec-tools into
	  a specially reserved region and then later executed after
	  a crash by kdump/kexec. The crash dump kernel must be compiled
	  to a memory address not used by the main kernel or BIOS using
	  PHYSICAL_START, or it must be built as a relocatable image
	  (CONFIG_RELOCATABLE=y).
	  For more details see Documentation/kdump/kdump.txt

Huang Ying's avatar
Huang Ying committed
1326
1327
1328
config KEXEC_JUMP
	bool "kexec jump (EXPERIMENTAL)"
	depends on EXPERIMENTAL
1329
	depends on KEXEC && HIBERNATION && X86_32
Huang Ying's avatar
Huang Ying committed
1330
	help
1331
1332
	  Jump between original kernel and kexeced kernel and invoke
	  code in physical address mode via KEXEC
Huang Ying's avatar
Huang Ying committed
1333

1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
config PHYSICAL_START
	hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
	default "0x1000000" if X86_NUMAQ
	default "0x200000" if X86_64
	default "0x100000"
	help
	  This gives the physical address where the kernel is loaded.

	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
	  bzImage will decompress itself to above physical address and
	  run from there. Otherwise, bzImage will run from the address where
	  it has been loaded by the boot loader and will ignore above physical
	  address.

	  In normal kdump cases one does not have to set/change this option
	  as now bzImage can be compiled as a completely relocatable image
	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
	  address. This option is mainly useful for the folks who don't want
	  to use a bzImage for capturing the crash dump and want to use a
	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
	  to be specifically compiled to run from a specific memory area
	  (normally a reserved region) and this option comes handy.

	  So if you are using bzImage for capturing the crash dump, leave
	  the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
	  Otherwise if you plan to use vmlinux for capturing the crash dump
	  change this value to start of the reserved region (Typically 16MB
	  0x1000000). In other words, it can be set based on the "X" value as
	  specified in the "crashkernel=YM@XM" command line boot parameter
	  passed to the panic-ed kernel. Typically this parameter is set as
	  crashkernel=64M@16M. Please take a look at
	  Documentation/kdump/kdump.txt for more details about crash dumps.

	  Usage of bzImage for capturing the crash dump is recommended as
	  one does not have to build two kernels. Same kernel can be used
	  as production kernel and capture kernel. Above option should have
	  gone away after relocatable bzImage support is introduced. But it
	  is present because there are users out there who continue to use
	  vmlinux for dump capture. This option should go away down the
	  line.

	  Don't change this unless you know what you are doing.

config RELOCATABLE
	bool "Build a relocatable kernel (EXPERIMENTAL)"
	depends on EXPERIMENTAL
	help
	  This builds a kernel image that retains relocation information
	  so it can be loaded someplace besides the default 1MB.
	  The relocations tend to make the kernel binary about 10% larger,
	  but are discarded at runtime.

	  One use is for the kexec on panic case where the recovery kernel
	  must live at a different physical address than the primary
	  kernel.

	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
	  it has been loaded at and the compile time physical address
	  (CONFIG_PHYSICAL_START) is ignored.

config PHYSICAL_ALIGN
	hex
	prompt "Alignment value to which kernel should be aligned" if X86_32
	default "0x100000" if X86_32
	default "0x200000" if X86_64
	range 0x2000 0x400000
	help
	  This value puts the alignment restrictions on physical address
	  where kernel is loaded and run from. Kernel is compiled for an
	  address which meets above alignment restriction.

	  If bootloader loads the kernel at a non-aligned address and
	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
	  address aligned to above value and run from there.

	  If bootloader loads the kernel at a non-aligned address and
	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
	  load address and decompress itself to the address it has been
	  compiled for and run from there. The address for which kernel is
	  compiled already meets above alignment restrictions. Hence the
	  end result is that kernel runs from a physical address meeting
	  above alignment restrictions.

	  Don't change this unless you know what you are doing.

config HOTPLUG_CPU
1420
1421
	bool "Support for hot-pluggable CPUs"
	depends on SMP && HOTPLUG && !X86_VOYAGER
1422
	---help---
1423
1424
1425
1426
1427
	  Say Y here to allow turning CPUs off and on. CPUs can be
	  controlled through /sys/devices/system/cpu.
	  ( Note: power management support will enable this option
	    automatically on SMP systems. )
	  Say N if you want to disable CPU hotplug.
1428
1429

config COMPAT_VDSO
1430
1431
	def_bool y
	prompt "Compat VDSO support"
Roland McGrath's avatar
Roland McGrath committed
1432
	depends on X86_32 || IA32_EMULATION
1433
	help
Roland McGrath's avatar
Roland McGrath committed
1434
	  Map the 32-bit VDSO to the predictable old-style address too.
1435
1436
1437
1438
1439
1440
1441
	---help---
	  Say N here if you are running a sufficiently recent glibc
	  version (2.3.3 or later), to remove the high-mapped
	  VDSO mapping and to exclusively use the randomized VDSO.

	  If unsure, say Y.

1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
config CMDLINE_BOOL
	bool "Built-in kernel command line"
	default n
	help
	  Allow for specifying boot arguments to the kernel at
	  build time.  On some systems (e.g. embedded ones), it is
	  necessary or convenient to provide some or all of the
	  kernel boot arguments with the kernel itself (that is,
	  to not rely on the boot loader to provide them.)

	  To compile command line arguments into the kernel,
	  set this option to 'Y', then fill in the
	  the boot arguments in CONFIG_CMDLINE.

	  Systems with fully functional boot loaders (i.e. non-embedded)
	  should leave this option set to 'N'.

config CMDLINE
	string "Built-in kernel command string"
	depends on CMDLINE_BOOL
	default ""
	help
	  Enter arguments here that should be compiled into the kernel
	  image and used at boot time.  If the boot loader provides a
	  command line at boot time, it is appended to this string to
	  form the full kernel command line, when the system boots.

	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
	  change this behavior.

	  In most cases, the command line (whether built-in or provided
	  by the boot loader) should specify the device for the root
	  file system.

config CMDLINE_OVERRIDE
	bool "Built-in command line overrides boot loader arguments"
	default n
	depends on CMDLINE_BOOL
	help
	  Set this option to 'Y' to have the kernel ignore the boot loader
	  command line, and use ONLY the built-in command line.

	  This is used to work around broken boot loaders.  This should
	  be set to 'N' under normal conditions.

1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
endmenu

config ARCH_ENABLE_MEMORY_HOTPLUG
	def_bool y
	depends on X86_64 || (X86_32 && HIGHMEM)

config HAVE_ARCH_EARLY_PFN_TO_NID
	def_bool X86_64
	depends on NUMA

1497
1498
1499
1500
menu "Power management options"
	depends on !X86_VOYAGER

config ARCH_HIBERNATION_HEADER
1501
	def_bool y
1502
1503
1504
1505
1506
1507
	depends on X86_64 && HIBERNATION

source "kernel/power/Kconfig"

source "drivers/acpi/Kconfig"

1508
1509
1510
1511
1512
config X86_APM_BOOT
	bool
	default y
	depends on APM || APM_MODULE

1513
1514
menuconfig APM
	tristate "APM (Advanced Power Management) BIOS support"
1515
	depends on X86_32 && PM_SLEEP
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
	---help---
	  APM is a BIOS specification for saving power using several different
	  techniques. This is mostly useful for battery powered laptops with
	  APM compliant BIOSes. If you say Y here, the system time will be
	  reset after a RESUME operation, the /proc/apm device will provide
	  battery status information, and user-space programs will receive
	  notification of APM "events" (e.g. battery status change).

	  If you select "Y" here, you can disable actual use of the APM
	  BIOS by passing the "apm=off" option to the kernel at boot time.

	  Note that the APM support is almost completely disabled for
	  machines with more than one CPU.

	  In order to use APM, you will need supporting software. For location
1531
	  and more information, read <file:Documentation/power/pm.txt> and the
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
	  Battery Powered Linux mini-HOWTO, available from
	  <http://www.tldp.org/docs.html#howto>.

	  This driver does not spin down disk drives (see the hdparm(8)
	  manpage ("man 8 hdparm") for that), and it doesn't turn off
	  VESA-compliant "green" monitors.

	  This driver does not support the TI 4000M TravelMate and the ACER
	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
	  desktop machines also don't have compliant BIOSes, and this driver
	  may cause those machines to panic during the boot phase.

	  Generally, if you don't have a battery in your machine, there isn't
	  much point in using this driver and you should say N. If you get
	  random kernel OOPSes or reboots that don't seem to be related to
	  anything, try disabling/enabling this option (or disabling/enabling
	  APM in your BIOS).

	  Some other things you should try when experiencing seemingly random,
	  "weird" problems:

	  1) make sure that you have enough swap space and that it is
	  enabled.
	  2) pass the "no-hlt" option to the kernel
	  3) switch on floating point emulation in the kernel and pass
	  the "no387" option to the kernel
	  4) pass the "floppy=nodma" option to the kernel
	  5) pass the "mem=4M" option to the kernel (thereby disabling
	  all but the first 4 MB of RAM)
	  6) make sure that the CPU is not over clocked.
	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
	  8) disable the cache from your BIOS settings
	  9) install a fan for the video card or exchange video RAM
	  10) install a better fan for the CPU
	  11) exchange RAM chips
	  12) exchange the motherboard.

	  To compile this driver as a module, choose M here: the
	  module will be called apm.

if APM

config APM_IGNORE_USER_SUSPEND
	bool "Ignore USER SUSPEND"
	help
	  This option will ignore USER SUSPEND requests. On machines with a
	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
	  series notebooks, it is necessary to say Y because of a BIOS bug.

config APM_DO_ENABLE
	bool "Enable PM at boot time"
	---help---
	  Enable APM features at boot time. From page 36 of the APM BIOS
	  specification: "When disabled, the APM BIOS does not automatically
	  power manage devices, enter the Standby State, enter the Suspend
	  State, or take power saving steps in response to CPU Idle calls."
	  This driver will make CPU Idle calls when Linux is idle (unless this
	  feature is turned off -- see "Do CPU IDLE calls", below). This
	  should always save battery power, but more complicated APM features
	  will be dependent on your BIOS implementation. You may need to turn
	  this option off if your computer hangs at boot time when using APM
	  support, or if it beeps continuously instead of suspending. Turn
	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
	  T400CDT. This is off by default since most machines do fine without
	  this feature.

config APM_CPU_IDLE
	bool "Make CPU Idle calls when idle"
	help
	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
	  On some machines, this can activate improved power savings, such as
	  a slowed CPU clock rate, when the machine is idle. These idle calls
	  are made after the idle loop has run for some length of time (e.g.,
	  333 mS). On some machines, this will cause a hang at boot time or
	  whenever the CPU becomes idle. (On machines with more than one CPU,
	  this option does nothing.)

config APM_DISPLAY_BLANK
	bool "Enable console blanking using APM"
	help
	  Enable console blanking using the APM. Some laptops can use this to
	  turn off the LCD backlight when the screen blanker of the Linux
	  virtual console blanks the screen. Note that this is only used by
	  the virtual console screen blanker, and won't turn off the backlight
	  when using the X Window system. This also doesn't have anything to
	  do with your VESA-compliant power-saving monitor. Further, this
	  option doesn't work for all laptops -- it might not turn off your
	  backlight at all, or it might print a lot of errors to the console,
	  especially if you are using gpm.

config APM_ALLOW_INTS
	bool "Allow interrupts during APM BIOS calls"
	help
	  Normally we disable external interrupts while we are making calls to
	  the APM BIOS as a measure to lessen the effects of a badly behaving
	  BIOS implementation.  The BIOS should reenable interrupts if it
	  needs to.  Unfortunately, some BIOSes do not -- especially those in
	  many of the newer IBM Thinkpads.  If you experience hangs when you
	  suspend, try setting this to Y.  Otherwise, say N.

config APM_REAL_MODE_POWER_OFF
	bool "Use real mode APM BIOS call to power off"
	help
	  Use real mode APM BIOS calls to switch off the computer. This is
	  a work-around for a number of buggy BIOSes. Switch this option on if
	  your computer crashes instead of powering off properly.

endif # APM

source "arch/x86/kernel/cpu/cpufreq/Kconfig"

source "drivers/cpuidle/Kconfig"

endmenu


menu "Bus options (PCI etc.)"

config PCI
Ingo Molnar's avatar
Ingo Molnar committed
1651
	bool "PCI support"
Adrian Bunk's avatar
Adrian Bunk committed
1652
	default y
1653
1654
1655
1656
1657
1658
1659
1660
1661
	select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
	help
	  Find out whether you have a PCI motherboard. PCI is the name of a
	  bus system, i.e. the way the CPU talks to the other stuff inside
	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
	  VESA. If you have PCI, say Y, otherwise N.

choice
	prompt "PCI access mode"
1662
	depends on X86_32 && PCI
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
	default PCI_GOANY
	---help---
	  On PCI systems, the BIOS can be used to detect the PCI devices and
	  determine their configuration. However, some old PCI motherboards
	  have BIOS bugs and may crash if this is done. Also, some embedded
	  PCI-based systems don't have any BIOS at all. Linux can also try to
	  detect the PCI hardware directly without using the BIOS.

	  With this option, you can specify how Linux should detect the
	  PCI devices. If you choose "BIOS", the BIOS will be used,
	  if you choose "Direct", the BIOS won't be used, and if you
	  choose "MMConfig", then PCI Express MMCONFIG will be used.
	  If you choose "Any", the kernel will try MMCONFIG, then the
	  direct access method and falls back to the BIOS if that doesn't
	  work. If unsure, go with the default, which is "Any".

config PCI_GOBIOS
	bool "BIOS"

config PCI_GOMMCONFIG
	bool "MMConfig"

config PCI_GODIRECT
	bool "Direct"

1688
1689
1690
1691
config PCI_GOOLPC
	bool "OLPC"
	depends on OLPC

1692
1693
1694
config PCI_GOANY
	bool "Any"

1695
1696
1697
endchoice

config PCI_BIOS
1698
	def_bool y
1699
	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1700
1701
1702

# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
1703
	def_bool y
1704
	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1705
1706

config PCI_MMCONFIG
1707
	def_bool y
1708
1709
	depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)

1710
config PCI_OLPC
1711
1712
	def_bool y
	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1713

1714
config PCI_DOMAINS
1715
	def_bool y
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
	depends on PCI

config PCI_MMCONFIG
	bool "Support mmconfig PCI config space access"
	depends on X86_64 && PCI && ACPI

config DMAR
	bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
	depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
	help
	  DMA remapping (DMAR) devices support enables independent address
	  translations for Direct Memory Access (DMA) from devices.
	  These DMA remapping devices are reported via ACPI tables
	  and include PCI device scope covered by these DMA
	  remapping devices.

config DMAR_GFX_WA
1733
1734
	def_bool y
	prompt "Support for Graphics workaround"
1735
1736
1737
1738
1739
1740
1741
1742
1743
	depends on DMAR
	help
	 Current Graphics drivers tend to use physical address
	 for DMA and avoid using DMA APIs. Setting this config
	 option permits the IOMMU driver to set a unity map for
	 all the OS-visible memory. Hence the driver can continue
	 to use physical addresses for DMA.

config DMAR_FLOPPY_WA
1744
	def_bool y
1745
1746
1747
1748
1749
1750
1751
	depends on DMAR
	help
	 Floppy disk drivers are know to bypass DMA API calls
	 thereby failing to work when IOMMU is enabled. This
	 workaround will setup a 1:1 mapping for the first
	 16M to make floppy (an ISA device) work.

1752
1753
1754
1755
1756
1757
1758
1759
config INTR_REMAP
	bool "Support for Interrupt Remapping (EXPERIMENTAL)"
	depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
	help
	 Supports Interrupt remapping for IO-APIC and MSI devices.
	 To use x2apic mode in the CPU's which support x2APIC enhancements or
	 to support platforms with CPU's having > 8 bit APIC ID, say Y.

1760
1761
1762
1763