Merge branch 'linus' into x86/tracehook
[GitHub/mt8127/android_kernel_alcatel_ttab.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_UNSTABLE_SCHED_CLOCK
22 select HAVE_IDE
23 select HAVE_OPROFILE
24 select HAVE_IOREMAP_PROT
25 select HAVE_KPROBES
26 select ARCH_WANT_OPTIONAL_GPIOLIB
27 select HAVE_KRETPROBES
28 select HAVE_DYNAMIC_FTRACE
29 select HAVE_FTRACE
30 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
31 select HAVE_ARCH_KGDB if !X86_VOYAGER
32 select HAVE_ARCH_TRACEHOOK
33 select HAVE_GENERIC_DMA_COHERENT if X86_32
34 select HAVE_EFFICIENT_UNALIGNED_ACCESS
35
36 config ARCH_DEFCONFIG
37 string
38 default "arch/x86/configs/i386_defconfig" if X86_32
39 default "arch/x86/configs/x86_64_defconfig" if X86_64
40
41
42 config GENERIC_LOCKBREAK
43 def_bool n
44
45 config GENERIC_TIME
46 def_bool y
47
48 config GENERIC_CMOS_UPDATE
49 def_bool y
50
51 config CLOCKSOURCE_WATCHDOG
52 def_bool y
53
54 config GENERIC_CLOCKEVENTS
55 def_bool y
56
57 config GENERIC_CLOCKEVENTS_BROADCAST
58 def_bool y
59 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
60
61 config LOCKDEP_SUPPORT
62 def_bool y
63
64 config STACKTRACE_SUPPORT
65 def_bool y
66
67 config HAVE_LATENCYTOP_SUPPORT
68 def_bool y
69
70 config FAST_CMPXCHG_LOCAL
71 bool
72 default y
73
74 config MMU
75 def_bool y
76
77 config ZONE_DMA
78 def_bool y
79
80 config SBUS
81 bool
82
83 config GENERIC_ISA_DMA
84 def_bool y
85
86 config GENERIC_IOMAP
87 def_bool y
88
89 config GENERIC_BUG
90 def_bool y
91 depends on BUG
92
93 config GENERIC_HWEIGHT
94 def_bool y
95
96 config GENERIC_GPIO
97 def_bool n
98
99 config ARCH_MAY_HAVE_PC_FDC
100 def_bool y
101
102 config RWSEM_GENERIC_SPINLOCK
103 def_bool !X86_XADD
104
105 config RWSEM_XCHGADD_ALGORITHM
106 def_bool X86_XADD
107
108 config ARCH_HAS_ILOG2_U32
109 def_bool n
110
111 config ARCH_HAS_ILOG2_U64
112 def_bool n
113
114 config ARCH_HAS_CPU_IDLE_WAIT
115 def_bool y
116
117 config GENERIC_CALIBRATE_DELAY
118 def_bool y
119
120 config GENERIC_TIME_VSYSCALL
121 bool
122 default X86_64
123
124 config ARCH_HAS_CPU_RELAX
125 def_bool y
126
127 config ARCH_HAS_CACHE_LINE_SIZE
128 def_bool y
129
130 config HAVE_SETUP_PER_CPU_AREA
131 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
132
133 config HAVE_CPUMASK_OF_CPU_MAP
134 def_bool X86_64_SMP
135
136 config ARCH_HIBERNATION_POSSIBLE
137 def_bool y
138 depends on !SMP || !X86_VOYAGER
139
140 config ARCH_SUSPEND_POSSIBLE
141 def_bool y
142 depends on !X86_VOYAGER
143
144 config ZONE_DMA32
145 bool
146 default X86_64
147
148 config ARCH_POPULATES_NODE_MAP
149 def_bool y
150
151 config AUDIT_ARCH
152 bool
153 default X86_64
154
155 config ARCH_SUPPORTS_AOUT
156 def_bool y
157
158 config ARCH_SUPPORTS_OPTIMIZED_INLINING
159 def_bool y
160
161 # Use the generic interrupt handling code in kernel/irq/:
162 config GENERIC_HARDIRQS
163 bool
164 default y
165
166 config GENERIC_IRQ_PROBE
167 bool
168 default y
169
170 config GENERIC_PENDING_IRQ
171 bool
172 depends on GENERIC_HARDIRQS && SMP
173 default y
174
175 config X86_SMP
176 bool
177 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
178 select USE_GENERIC_SMP_HELPERS
179 default y
180
181 config X86_32_SMP
182 def_bool y
183 depends on X86_32 && SMP
184
185 config X86_64_SMP
186 def_bool y
187 depends on X86_64 && SMP
188
189 config X86_HT
190 bool
191 depends on SMP
192 depends on (X86_32 && !X86_VOYAGER) || X86_64
193 default y
194
195 config X86_BIOS_REBOOT
196 bool
197 depends on !X86_VOYAGER
198 default y
199
200 config X86_TRAMPOLINE
201 bool
202 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
203 default y
204
205 config KTIME_SCALAR
206 def_bool X86_32
207 source "init/Kconfig"
208
209 menu "Processor type and features"
210
211 source "kernel/time/Kconfig"
212
213 config SMP
214 bool "Symmetric multi-processing support"
215 ---help---
216 This enables support for systems with more than one CPU. If you have
217 a system with only one CPU, like most personal computers, say N. If
218 you have a system with more than one CPU, say Y.
219
220 If you say N here, the kernel will run on single and multiprocessor
221 machines, but will use only one CPU of a multiprocessor machine. If
222 you say Y here, the kernel will run on many, but not all,
223 singleprocessor machines. On a singleprocessor machine, the kernel
224 will run faster if you say N here.
225
226 Note that if you say Y here and choose architecture "586" or
227 "Pentium" under "Processor family", the kernel will not work on 486
228 architectures. Similarly, multiprocessor kernels for the "PPro"
229 architecture may not work on all Pentium based boards.
230
231 People using multiprocessor machines who say Y here should also say
232 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
233 Management" code will be disabled if you say Y here.
234
235 See also <file:Documentation/i386/IO-APIC.txt>,
236 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
237 <http://www.tldp.org/docs.html#howto>.
238
239 If you don't know what to do here, say N.
240
241 config X86_FIND_SMP_CONFIG
242 def_bool y
243 depends on X86_MPPARSE || X86_VOYAGER
244
245 if ACPI
246 config X86_MPPARSE
247 def_bool y
248 bool "Enable MPS table"
249 depends on X86_LOCAL_APIC
250 help
251 For old smp systems that do not have proper acpi support. Newer systems
252 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
253 endif
254
255 if !ACPI
256 config X86_MPPARSE
257 def_bool y
258 depends on X86_LOCAL_APIC
259 endif
260
261 choice
262 prompt "Subarchitecture Type"
263 default X86_PC
264
265 config X86_PC
266 bool "PC-compatible"
267 help
268 Choose this option if your computer is a standard PC or compatible.
269
270 config X86_ELAN
271 bool "AMD Elan"
272 depends on X86_32
273 help
274 Select this for an AMD Elan processor.
275
276 Do not use this option for K6/Athlon/Opteron processors!
277
278 If unsure, choose "PC-compatible" instead.
279
280 config X86_VOYAGER
281 bool "Voyager (NCR)"
282 depends on X86_32 && (SMP || BROKEN) && !PCI
283 help
284 Voyager is an MCA-based 32-way capable SMP architecture proprietary
285 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
286
287 *** WARNING ***
288
289 If you do not specifically know you have a Voyager based machine,
290 say N here, otherwise the kernel you build will not be bootable.
291
292 config X86_GENERICARCH
293 bool "Generic architecture"
294 depends on X86_32
295 help
296 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
297 subarchitectures. It is intended for a generic binary kernel.
298 if you select them all, kernel will probe it one by one. and will
299 fallback to default.
300
301 if X86_GENERICARCH
302
303 config X86_NUMAQ
304 bool "NUMAQ (IBM/Sequent)"
305 depends on SMP && X86_32 && PCI && X86_MPPARSE
306 select NUMA
307 help
308 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
309 NUMA multiquad box. This changes the way that processors are
310 bootstrapped, and uses Clustered Logical APIC addressing mode instead
311 of Flat Logical. You will need a new lynxer.elf file to flash your
312 firmware with - send email to <Martin.Bligh@us.ibm.com>.
313
314 config X86_SUMMIT
315 bool "Summit/EXA (IBM x440)"
316 depends on X86_32 && SMP
317 help
318 This option is needed for IBM systems that use the Summit/EXA chipset.
319 In particular, it is needed for the x440.
320
321 config X86_ES7000
322 bool "Support for Unisys ES7000 IA32 series"
323 depends on X86_32 && SMP
324 help
325 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
326 supposed to run on an IA32-based Unisys ES7000 system.
327
328 config X86_BIGSMP
329 bool "Support for big SMP systems with more than 8 CPUs"
330 depends on X86_32 && SMP
331 help
332 This option is needed for the systems that have more than 8 CPUs
333 and if the system is not of any sub-arch type above.
334
335 endif
336
337 config X86_VSMP
338 bool "Support for ScaleMP vSMP"
339 select PARAVIRT
340 depends on X86_64 && PCI
341 help
342 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
343 supposed to run on these EM64T-based machines. Only choose this option
344 if you have one of these machines.
345
346 endchoice
347
348 config X86_VISWS
349 bool "SGI 320/540 (Visual Workstation)"
350 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
351 help
352 The SGI Visual Workstation series is an IA32-based workstation
353 based on SGI systems chips with some legacy PC hardware attached.
354
355 Say Y here to create a kernel to run on the SGI 320 or 540.
356
357 A kernel compiled for the Visual Workstation will run on general
358 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
359
360 config X86_RDC321X
361 bool "RDC R-321x SoC"
362 depends on X86_32
363 select M486
364 select X86_REBOOTFIXUPS
365 help
366 This option is needed for RDC R-321x system-on-chip, also known
367 as R-8610-(G).
368 If you don't have one of these chips, you should say N here.
369
370 config SCHED_NO_NO_OMIT_FRAME_POINTER
371 def_bool y
372 prompt "Single-depth WCHAN output"
373 depends on X86_32
374 help
375 Calculate simpler /proc/<PID>/wchan values. If this option
376 is disabled then wchan values will recurse back to the
377 caller function. This provides more accurate wchan values,
378 at the expense of slightly more scheduling overhead.
379
380 If in doubt, say "Y".
381
382 menuconfig PARAVIRT_GUEST
383 bool "Paravirtualized guest support"
384 help
385 Say Y here to get to see options related to running Linux under
386 various hypervisors. This option alone does not add any kernel code.
387
388 If you say N, all options in this submenu will be skipped and disabled.
389
390 if PARAVIRT_GUEST
391
392 source "arch/x86/xen/Kconfig"
393
394 config VMI
395 bool "VMI Guest support"
396 select PARAVIRT
397 depends on X86_32
398 depends on !X86_VOYAGER
399 help
400 VMI provides a paravirtualized interface to the VMware ESX server
401 (it could be used by other hypervisors in theory too, but is not
402 at the moment), by linking the kernel to a GPL-ed ROM module
403 provided by the hypervisor.
404
405 config KVM_CLOCK
406 bool "KVM paravirtualized clock"
407 select PARAVIRT
408 select PARAVIRT_CLOCK
409 depends on !X86_VOYAGER
410 help
411 Turning on this option will allow you to run a paravirtualized clock
412 when running over the KVM hypervisor. Instead of relying on a PIT
413 (or probably other) emulation by the underlying device model, the host
414 provides the guest with timing infrastructure such as time of day, and
415 system time
416
417 config KVM_GUEST
418 bool "KVM Guest support"
419 select PARAVIRT
420 depends on !X86_VOYAGER
421 help
422 This option enables various optimizations for running under the KVM
423 hypervisor.
424
425 source "arch/x86/lguest/Kconfig"
426
427 config PARAVIRT
428 bool "Enable paravirtualization code"
429 depends on !X86_VOYAGER
430 help
431 This changes the kernel so it can modify itself when it is run
432 under a hypervisor, potentially improving performance significantly
433 over full virtualization. However, when run without a hypervisor
434 the kernel is theoretically slower and slightly larger.
435
436 config PARAVIRT_CLOCK
437 bool
438 default n
439
440 endif
441
442 config PARAVIRT_DEBUG
443 bool "paravirt-ops debugging"
444 depends on PARAVIRT && DEBUG_KERNEL
445 help
446 Enable to debug paravirt_ops internals. Specifically, BUG if
447 a paravirt_op is missing when it is called.
448
449 config MEMTEST
450 bool "Memtest"
451 help
452 This option adds a kernel parameter 'memtest', which allows memtest
453 to be set.
454 memtest=0, mean disabled; -- default
455 memtest=1, mean do 1 test pattern;
456 ...
457 memtest=4, mean do 4 test patterns.
458 If you are unsure how to answer this question, answer N.
459
460 config X86_SUMMIT_NUMA
461 def_bool y
462 depends on X86_32 && NUMA && X86_GENERICARCH
463
464 config X86_CYCLONE_TIMER
465 def_bool y
466 depends on X86_GENERICARCH
467
468 config ES7000_CLUSTERED_APIC
469 def_bool y
470 depends on SMP && X86_ES7000 && MPENTIUMIII
471
472 source "arch/x86/Kconfig.cpu"
473
474 config HPET_TIMER
475 def_bool X86_64
476 prompt "HPET Timer Support" if X86_32
477 help
478 Use the IA-PC HPET (High Precision Event Timer) to manage
479 time in preference to the PIT and RTC, if a HPET is
480 present.
481 HPET is the next generation timer replacing legacy 8254s.
482 The HPET provides a stable time base on SMP
483 systems, unlike the TSC, but it is more expensive to access,
484 as it is off-chip. You can find the HPET spec at
485 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
486
487 You can safely choose Y here. However, HPET will only be
488 activated if the platform and the BIOS support this feature.
489 Otherwise the 8254 will be used for timing services.
490
491 Choose N to continue using the legacy 8254 timer.
492
493 config HPET_EMULATE_RTC
494 def_bool y
495 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
496
497 # Mark as embedded because too many people got it wrong.
498 # The code disables itself when not needed.
499 config DMI
500 default y
501 bool "Enable DMI scanning" if EMBEDDED
502 help
503 Enabled scanning of DMI to identify machine quirks. Say Y
504 here unless you have verified that your setup is not
505 affected by entries in the DMI blacklist. Required by PNP
506 BIOS code.
507
508 config GART_IOMMU
509 bool "GART IOMMU support" if EMBEDDED
510 default y
511 select SWIOTLB
512 select AGP
513 depends on X86_64 && PCI
514 help
515 Support for full DMA access of devices with 32bit memory access only
516 on systems with more than 3GB. This is usually needed for USB,
517 sound, many IDE/SATA chipsets and some other devices.
518 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
519 based hardware IOMMU and a software bounce buffer based IOMMU used
520 on Intel systems and as fallback.
521 The code is only active when needed (enough memory and limited
522 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
523 too.
524
525 config CALGARY_IOMMU
526 bool "IBM Calgary IOMMU support"
527 select SWIOTLB
528 depends on X86_64 && PCI && EXPERIMENTAL
529 help
530 Support for hardware IOMMUs in IBM's xSeries x366 and x460
531 systems. Needed to run systems with more than 3GB of memory
532 properly with 32-bit PCI devices that do not support DAC
533 (Double Address Cycle). Calgary also supports bus level
534 isolation, where all DMAs pass through the IOMMU. This
535 prevents them from going anywhere except their intended
536 destination. This catches hard-to-find kernel bugs and
537 mis-behaving drivers and devices that do not use the DMA-API
538 properly to set up their DMA buffers. The IOMMU can be
539 turned off at boot time with the iommu=off parameter.
540 Normally the kernel will make the right choice by itself.
541 If unsure, say Y.
542
543 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
544 def_bool y
545 prompt "Should Calgary be enabled by default?"
546 depends on CALGARY_IOMMU
547 help
548 Should Calgary be enabled by default? if you choose 'y', Calgary
549 will be used (if it exists). If you choose 'n', Calgary will not be
550 used even if it exists. If you choose 'n' and would like to use
551 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
552 If unsure, say Y.
553
554 config AMD_IOMMU
555 bool "AMD IOMMU support"
556 select SWIOTLB
557 depends on X86_64 && PCI && ACPI
558 help
559 With this option you can enable support for AMD IOMMU hardware in
560 your system. An IOMMU is a hardware component which provides
561 remapping of DMA memory accesses from devices. With an AMD IOMMU you
562 can isolate the the DMA memory of different devices and protect the
563 system from misbehaving device drivers or hardware.
564
565 You can find out if your system has an AMD IOMMU if you look into
566 your BIOS for an option to enable it or if you have an IVRS ACPI
567 table.
568
569 # need this always selected by IOMMU for the VIA workaround
570 config SWIOTLB
571 bool
572 help
573 Support for software bounce buffers used on x86-64 systems
574 which don't have a hardware IOMMU (e.g. the current generation
575 of Intel's x86-64 CPUs). Using this PCI devices which can only
576 access 32-bits of memory can be used on systems with more than
577 3 GB of memory. If unsure, say Y.
578
579 config IOMMU_HELPER
580 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
581
582 config MAXSMP
583 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
584 depends on X86_64 && SMP && BROKEN
585 default n
586 help
587 Configure maximum number of CPUS and NUMA Nodes for this architecture.
588 If unsure, say N.
589
590 config NR_CPUS
591 int "Maximum number of CPUs (2-512)" if !MAXSMP
592 range 2 512
593 depends on SMP
594 default "4096" if MAXSMP
595 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
596 default "8"
597 help
598 This allows you to specify the maximum number of CPUs which this
599 kernel will support. The maximum supported value is 512 and the
600 minimum value which makes sense is 2.
601
602 This is purely to save memory - each supported CPU adds
603 approximately eight kilobytes to the kernel image.
604
605 config SCHED_SMT
606 bool "SMT (Hyperthreading) scheduler support"
607 depends on X86_HT
608 help
609 SMT scheduler support improves the CPU scheduler's decision making
610 when dealing with Intel Pentium 4 chips with HyperThreading at a
611 cost of slightly increased overhead in some places. If unsure say
612 N here.
613
614 config SCHED_MC
615 def_bool y
616 prompt "Multi-core scheduler support"
617 depends on X86_HT
618 help
619 Multi-core scheduler support improves the CPU scheduler's decision
620 making when dealing with multi-core CPU chips at a cost of slightly
621 increased overhead in some places. If unsure say N here.
622
623 source "kernel/Kconfig.preempt"
624
625 config X86_UP_APIC
626 bool "Local APIC support on uniprocessors"
627 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
628 help
629 A local APIC (Advanced Programmable Interrupt Controller) is an
630 integrated interrupt controller in the CPU. If you have a single-CPU
631 system which has a processor with a local APIC, you can say Y here to
632 enable and use it. If you say Y here even though your machine doesn't
633 have a local APIC, then the kernel will still run with no slowdown at
634 all. The local APIC supports CPU-generated self-interrupts (timer,
635 performance counters), and the NMI watchdog which detects hard
636 lockups.
637
638 config X86_UP_IOAPIC
639 bool "IO-APIC support on uniprocessors"
640 depends on X86_UP_APIC
641 help
642 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
643 SMP-capable replacement for PC-style interrupt controllers. Most
644 SMP systems and many recent uniprocessor systems have one.
645
646 If you have a single-CPU system with an IO-APIC, you can say Y here
647 to use it. If you say Y here even though your machine doesn't have
648 an IO-APIC, then the kernel will still run with no slowdown at all.
649
650 config X86_LOCAL_APIC
651 def_bool y
652 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
653
654 config X86_IO_APIC
655 def_bool y
656 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
657
658 config X86_VISWS_APIC
659 def_bool y
660 depends on X86_32 && X86_VISWS
661
662 config X86_MCE
663 bool "Machine Check Exception"
664 depends on !X86_VOYAGER
665 ---help---
666 Machine Check Exception support allows the processor to notify the
667 kernel if it detects a problem (e.g. overheating, component failure).
668 The action the kernel takes depends on the severity of the problem,
669 ranging from a warning message on the console, to halting the machine.
670 Your processor must be a Pentium or newer to support this - check the
671 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
672 have a design flaw which leads to false MCE events - hence MCE is
673 disabled on all P5 processors, unless explicitly enabled with "mce"
674 as a boot argument. Similarly, if MCE is built in and creates a
675 problem on some new non-standard machine, you can boot with "nomce"
676 to disable it. MCE support simply ignores non-MCE processors like
677 the 386 and 486, so nearly everyone can say Y here.
678
679 config X86_MCE_INTEL
680 def_bool y
681 prompt "Intel MCE features"
682 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
683 help
684 Additional support for intel specific MCE features such as
685 the thermal monitor.
686
687 config X86_MCE_AMD
688 def_bool y
689 prompt "AMD MCE features"
690 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
691 help
692 Additional support for AMD specific MCE features such as
693 the DRAM Error Threshold.
694
695 config X86_MCE_NONFATAL
696 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
697 depends on X86_32 && X86_MCE
698 help
699 Enabling this feature starts a timer that triggers every 5 seconds which
700 will look at the machine check registers to see if anything happened.
701 Non-fatal problems automatically get corrected (but still logged).
702 Disable this if you don't want to see these messages.
703 Seeing the messages this option prints out may be indicative of dying
704 or out-of-spec (ie, overclocked) hardware.
705 This option only does something on certain CPUs.
706 (AMD Athlon/Duron and Intel Pentium 4)
707
708 config X86_MCE_P4THERMAL
709 bool "check for P4 thermal throttling interrupt."
710 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
711 help
712 Enabling this feature will cause a message to be printed when the P4
713 enters thermal throttling.
714
715 config VM86
716 bool "Enable VM86 support" if EMBEDDED
717 default y
718 depends on X86_32
719 help
720 This option is required by programs like DOSEMU to run 16-bit legacy
721 code on X86 processors. It also may be needed by software like
722 XFree86 to initialize some video cards via BIOS. Disabling this
723 option saves about 6k.
724
725 config TOSHIBA
726 tristate "Toshiba Laptop support"
727 depends on X86_32
728 ---help---
729 This adds a driver to safely access the System Management Mode of
730 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
731 not work on models with a Phoenix BIOS. The System Management Mode
732 is used to set the BIOS and power saving options on Toshiba portables.
733
734 For information on utilities to make use of this driver see the
735 Toshiba Linux utilities web site at:
736 <http://www.buzzard.org.uk/toshiba/>.
737
738 Say Y if you intend to run this kernel on a Toshiba portable.
739 Say N otherwise.
740
741 config I8K
742 tristate "Dell laptop support"
743 ---help---
744 This adds a driver to safely access the System Management Mode
745 of the CPU on the Dell Inspiron 8000. The System Management Mode
746 is used to read cpu temperature and cooling fan status and to
747 control the fans on the I8K portables.
748
749 This driver has been tested only on the Inspiron 8000 but it may
750 also work with other Dell laptops. You can force loading on other
751 models by passing the parameter `force=1' to the module. Use at
752 your own risk.
753
754 For information on utilities to make use of this driver see the
755 I8K Linux utilities web site at:
756 <http://people.debian.org/~dz/i8k/>
757
758 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
759 Say N otherwise.
760
761 config X86_REBOOTFIXUPS
762 def_bool n
763 prompt "Enable X86 board specific fixups for reboot"
764 depends on X86_32 && X86
765 ---help---
766 This enables chipset and/or board specific fixups to be done
767 in order to get reboot to work correctly. This is only needed on
768 some combinations of hardware and BIOS. The symptom, for which
769 this config is intended, is when reboot ends with a stalled/hung
770 system.
771
772 Currently, the only fixup is for the Geode machines using
773 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
774
775 Say Y if you want to enable the fixup. Currently, it's safe to
776 enable this option even if you don't need it.
777 Say N otherwise.
778
779 config MICROCODE
780 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
781 select FW_LOADER
782 ---help---
783 If you say Y here, you will be able to update the microcode on
784 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
785 Pentium III, Pentium 4, Xeon etc. You will obviously need the
786 actual microcode binary data itself which is not shipped with the
787 Linux kernel.
788
789 For latest news and information on obtaining all the required
790 ingredients for this driver, check:
791 <http://www.urbanmyth.org/microcode/>.
792
793 To compile this driver as a module, choose M here: the
794 module will be called microcode.
795
796 config MICROCODE_OLD_INTERFACE
797 def_bool y
798 depends on MICROCODE
799
800 config X86_MSR
801 tristate "/dev/cpu/*/msr - Model-specific register support"
802 help
803 This device gives privileged processes access to the x86
804 Model-Specific Registers (MSRs). It is a character device with
805 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
806 MSR accesses are directed to a specific CPU on multi-processor
807 systems.
808
809 config X86_CPUID
810 tristate "/dev/cpu/*/cpuid - CPU information support"
811 help
812 This device gives processes access to the x86 CPUID instruction to
813 be executed on a specific processor. It is a character device
814 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
815 /dev/cpu/31/cpuid.
816
817 choice
818 prompt "High Memory Support"
819 default HIGHMEM4G if !X86_NUMAQ
820 default HIGHMEM64G if X86_NUMAQ
821 depends on X86_32
822
823 config NOHIGHMEM
824 bool "off"
825 depends on !X86_NUMAQ
826 ---help---
827 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
828 However, the address space of 32-bit x86 processors is only 4
829 Gigabytes large. That means that, if you have a large amount of
830 physical memory, not all of it can be "permanently mapped" by the
831 kernel. The physical memory that's not permanently mapped is called
832 "high memory".
833
834 If you are compiling a kernel which will never run on a machine with
835 more than 1 Gigabyte total physical RAM, answer "off" here (default
836 choice and suitable for most users). This will result in a "3GB/1GB"
837 split: 3GB are mapped so that each process sees a 3GB virtual memory
838 space and the remaining part of the 4GB virtual memory space is used
839 by the kernel to permanently map as much physical memory as
840 possible.
841
842 If the machine has between 1 and 4 Gigabytes physical RAM, then
843 answer "4GB" here.
844
845 If more than 4 Gigabytes is used then answer "64GB" here. This
846 selection turns Intel PAE (Physical Address Extension) mode on.
847 PAE implements 3-level paging on IA32 processors. PAE is fully
848 supported by Linux, PAE mode is implemented on all recent Intel
849 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
850 then the kernel will not boot on CPUs that don't support PAE!
851
852 The actual amount of total physical memory will either be
853 auto detected or can be forced by using a kernel command line option
854 such as "mem=256M". (Try "man bootparam" or see the documentation of
855 your boot loader (lilo or loadlin) about how to pass options to the
856 kernel at boot time.)
857
858 If unsure, say "off".
859
860 config HIGHMEM4G
861 bool "4GB"
862 depends on !X86_NUMAQ
863 help
864 Select this if you have a 32-bit processor and between 1 and 4
865 gigabytes of physical RAM.
866
867 config HIGHMEM64G
868 bool "64GB"
869 depends on !M386 && !M486
870 select X86_PAE
871 help
872 Select this if you have a 32-bit processor and more than 4
873 gigabytes of physical RAM.
874
875 endchoice
876
877 choice
878 depends on EXPERIMENTAL
879 prompt "Memory split" if EMBEDDED
880 default VMSPLIT_3G
881 depends on X86_32
882 help
883 Select the desired split between kernel and user memory.
884
885 If the address range available to the kernel is less than the
886 physical memory installed, the remaining memory will be available
887 as "high memory". Accessing high memory is a little more costly
888 than low memory, as it needs to be mapped into the kernel first.
889 Note that increasing the kernel address space limits the range
890 available to user programs, making the address space there
891 tighter. Selecting anything other than the default 3G/1G split
892 will also likely make your kernel incompatible with binary-only
893 kernel modules.
894
895 If you are not absolutely sure what you are doing, leave this
896 option alone!
897
898 config VMSPLIT_3G
899 bool "3G/1G user/kernel split"
900 config VMSPLIT_3G_OPT
901 depends on !X86_PAE
902 bool "3G/1G user/kernel split (for full 1G low memory)"
903 config VMSPLIT_2G
904 bool "2G/2G user/kernel split"
905 config VMSPLIT_2G_OPT
906 depends on !X86_PAE
907 bool "2G/2G user/kernel split (for full 2G low memory)"
908 config VMSPLIT_1G
909 bool "1G/3G user/kernel split"
910 endchoice
911
912 config PAGE_OFFSET
913 hex
914 default 0xB0000000 if VMSPLIT_3G_OPT
915 default 0x80000000 if VMSPLIT_2G
916 default 0x78000000 if VMSPLIT_2G_OPT
917 default 0x40000000 if VMSPLIT_1G
918 default 0xC0000000
919 depends on X86_32
920
921 config HIGHMEM
922 def_bool y
923 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
924
925 config X86_PAE
926 def_bool n
927 prompt "PAE (Physical Address Extension) Support"
928 depends on X86_32 && !HIGHMEM4G
929 select RESOURCES_64BIT
930 help
931 PAE is required for NX support, and furthermore enables
932 larger swapspace support for non-overcommit purposes. It
933 has the cost of more pagetable lookup overhead, and also
934 consumes more pagetable space per process.
935
936 # Common NUMA Features
937 config NUMA
938 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
939 depends on SMP
940 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
941 default n if X86_PC
942 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
943 help
944 Enable NUMA (Non Uniform Memory Access) support.
945 The kernel will try to allocate memory used by a CPU on the
946 local memory controller of the CPU and add some more
947 NUMA awareness to the kernel.
948
949 For 32-bit this is currently highly experimental and should be only
950 used for kernel development. It might also cause boot failures.
951 For 64-bit this is recommended on all multiprocessor Opteron systems.
952 If the system is EM64T, you should say N unless your system is
953 EM64T NUMA.
954
955 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
956 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
957
958 config K8_NUMA
959 def_bool y
960 prompt "Old style AMD Opteron NUMA detection"
961 depends on X86_64 && NUMA && PCI
962 help
963 Enable K8 NUMA node topology detection. You should say Y here if
964 you have a multi processor AMD K8 system. This uses an old
965 method to read the NUMA configuration directly from the builtin
966 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
967 instead, which also takes priority if both are compiled in.
968
969 config X86_64_ACPI_NUMA
970 def_bool y
971 prompt "ACPI NUMA detection"
972 depends on X86_64 && NUMA && ACPI && PCI
973 select ACPI_NUMA
974 help
975 Enable ACPI SRAT based node topology detection.
976
977 # Some NUMA nodes have memory ranges that span
978 # other nodes. Even though a pfn is valid and
979 # between a node's start and end pfns, it may not
980 # reside on that node. See memmap_init_zone()
981 # for details.
982 config NODES_SPAN_OTHER_NODES
983 def_bool y
984 depends on X86_64_ACPI_NUMA
985
986 config NUMA_EMU
987 bool "NUMA emulation"
988 depends on X86_64 && NUMA
989 help
990 Enable NUMA emulation. A flat machine will be split
991 into virtual nodes when booted with "numa=fake=N", where N is the
992 number of nodes. This is only useful for debugging.
993
994 config NODES_SHIFT
995 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
996 range 1 9 if X86_64
997 default "9" if MAXSMP
998 default "6" if X86_64
999 default "4" if X86_NUMAQ
1000 default "3"
1001 depends on NEED_MULTIPLE_NODES
1002 help
1003 Specify the maximum number of NUMA Nodes available on the target
1004 system. Increases memory reserved to accomodate various tables.
1005
1006 config HAVE_ARCH_BOOTMEM_NODE
1007 def_bool y
1008 depends on X86_32 && NUMA
1009
1010 config ARCH_HAVE_MEMORY_PRESENT
1011 def_bool y
1012 depends on X86_32 && DISCONTIGMEM
1013
1014 config NEED_NODE_MEMMAP_SIZE
1015 def_bool y
1016 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1017
1018 config HAVE_ARCH_ALLOC_REMAP
1019 def_bool y
1020 depends on X86_32 && NUMA
1021
1022 config ARCH_FLATMEM_ENABLE
1023 def_bool y
1024 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
1025
1026 config ARCH_DISCONTIGMEM_ENABLE
1027 def_bool y
1028 depends on NUMA && X86_32
1029
1030 config ARCH_DISCONTIGMEM_DEFAULT
1031 def_bool y
1032 depends on NUMA && X86_32
1033
1034 config ARCH_SPARSEMEM_DEFAULT
1035 def_bool y
1036 depends on X86_64
1037
1038 config ARCH_SPARSEMEM_ENABLE
1039 def_bool y
1040 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
1041 select SPARSEMEM_STATIC if X86_32
1042 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1043
1044 config ARCH_SELECT_MEMORY_MODEL
1045 def_bool y
1046 depends on ARCH_SPARSEMEM_ENABLE
1047
1048 config ARCH_MEMORY_PROBE
1049 def_bool X86_64
1050 depends on MEMORY_HOTPLUG
1051
1052 source "mm/Kconfig"
1053
1054 config HIGHPTE
1055 bool "Allocate 3rd-level pagetables from highmem"
1056 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1057 help
1058 The VM uses one page table entry for each page of physical memory.
1059 For systems with a lot of RAM, this can be wasteful of precious
1060 low memory. Setting this option will put user-space page table
1061 entries in high memory.
1062
1063 config MATH_EMULATION
1064 bool
1065 prompt "Math emulation" if X86_32
1066 ---help---
1067 Linux can emulate a math coprocessor (used for floating point
1068 operations) if you don't have one. 486DX and Pentium processors have
1069 a math coprocessor built in, 486SX and 386 do not, unless you added
1070 a 487DX or 387, respectively. (The messages during boot time can
1071 give you some hints here ["man dmesg"].) Everyone needs either a
1072 coprocessor or this emulation.
1073
1074 If you don't have a math coprocessor, you need to say Y here; if you
1075 say Y here even though you have a coprocessor, the coprocessor will
1076 be used nevertheless. (This behavior can be changed with the kernel
1077 command line option "no387", which comes handy if your coprocessor
1078 is broken. Try "man bootparam" or see the documentation of your boot
1079 loader (lilo or loadlin) about how to pass options to the kernel at
1080 boot time.) This means that it is a good idea to say Y here if you
1081 intend to use this kernel on different machines.
1082
1083 More information about the internals of the Linux math coprocessor
1084 emulation can be found in <file:arch/x86/math-emu/README>.
1085
1086 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1087 kernel, it won't hurt.
1088
1089 config MTRR
1090 bool "MTRR (Memory Type Range Register) support"
1091 ---help---
1092 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1093 the Memory Type Range Registers (MTRRs) may be used to control
1094 processor access to memory ranges. This is most useful if you have
1095 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1096 allows bus write transfers to be combined into a larger transfer
1097 before bursting over the PCI/AGP bus. This can increase performance
1098 of image write operations 2.5 times or more. Saying Y here creates a
1099 /proc/mtrr file which may be used to manipulate your processor's
1100 MTRRs. Typically the X server should use this.
1101
1102 This code has a reasonably generic interface so that similar
1103 control registers on other processors can be easily supported
1104 as well:
1105
1106 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1107 Registers (ARRs) which provide a similar functionality to MTRRs. For
1108 these, the ARRs are used to emulate the MTRRs.
1109 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1110 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1111 write-combining. All of these processors are supported by this code
1112 and it makes sense to say Y here if you have one of them.
1113
1114 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1115 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1116 can lead to all sorts of problems, so it's good to say Y here.
1117
1118 You can safely say Y even if your machine doesn't have MTRRs, you'll
1119 just add about 9 KB to your kernel.
1120
1121 See <file:Documentation/mtrr.txt> for more information.
1122
1123 config MTRR_SANITIZER
1124 bool
1125 prompt "MTRR cleanup support"
1126 depends on MTRR
1127 help
1128 Convert MTRR layout from continuous to discrete, so X drivers can
1129 add writeback entries.
1130
1131 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1132 The largest mtrr entry size for a continous block can be set with
1133 mtrr_chunk_size.
1134
1135 If unsure, say N.
1136
1137 config MTRR_SANITIZER_ENABLE_DEFAULT
1138 int "MTRR cleanup enable value (0-1)"
1139 range 0 1
1140 default "0"
1141 depends on MTRR_SANITIZER
1142 help
1143 Enable mtrr cleanup default value
1144
1145 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1146 int "MTRR cleanup spare reg num (0-7)"
1147 range 0 7
1148 default "1"
1149 depends on MTRR_SANITIZER
1150 help
1151 mtrr cleanup spare entries default, it can be changed via
1152 mtrr_spare_reg_nr=N on the kernel command line.
1153
1154 config X86_PAT
1155 bool
1156 prompt "x86 PAT support"
1157 depends on MTRR
1158 help
1159 Use PAT attributes to setup page level cache control.
1160
1161 PATs are the modern equivalents of MTRRs and are much more
1162 flexible than MTRRs.
1163
1164 Say N here if you see bootup problems (boot crash, boot hang,
1165 spontaneous reboots) or a non-working video driver.
1166
1167 If unsure, say Y.
1168
1169 config EFI
1170 def_bool n
1171 prompt "EFI runtime service support"
1172 depends on ACPI
1173 ---help---
1174 This enables the kernel to use EFI runtime services that are
1175 available (such as the EFI variable services).
1176
1177 This option is only useful on systems that have EFI firmware.
1178 In addition, you should use the latest ELILO loader available
1179 at <http://elilo.sourceforge.net> in order to take advantage
1180 of EFI runtime services. However, even with this option, the
1181 resultant kernel should continue to boot on existing non-EFI
1182 platforms.
1183
1184 config IRQBALANCE
1185 def_bool y
1186 prompt "Enable kernel irq balancing"
1187 depends on X86_32 && SMP && X86_IO_APIC
1188 help
1189 The default yes will allow the kernel to do irq load balancing.
1190 Saying no will keep the kernel from doing irq load balancing.
1191
1192 config SECCOMP
1193 def_bool y
1194 prompt "Enable seccomp to safely compute untrusted bytecode"
1195 depends on PROC_FS
1196 help
1197 This kernel feature is useful for number crunching applications
1198 that may need to compute untrusted bytecode during their
1199 execution. By using pipes or other transports made available to
1200 the process as file descriptors supporting the read/write
1201 syscalls, it's possible to isolate those applications in
1202 their own address space using seccomp. Once seccomp is
1203 enabled via /proc/<pid>/seccomp, it cannot be disabled
1204 and the task is only allowed to execute a few safe syscalls
1205 defined by each seccomp mode.
1206
1207 If unsure, say Y. Only embedded should say N here.
1208
1209 config CC_STACKPROTECTOR
1210 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1211 depends on X86_64 && EXPERIMENTAL && BROKEN
1212 help
1213 This option turns on the -fstack-protector GCC feature. This
1214 feature puts, at the beginning of critical functions, a canary
1215 value on the stack just before the return address, and validates
1216 the value just before actually returning. Stack based buffer
1217 overflows (that need to overwrite this return address) now also
1218 overwrite the canary, which gets detected and the attack is then
1219 neutralized via a kernel panic.
1220
1221 This feature requires gcc version 4.2 or above, or a distribution
1222 gcc with the feature backported. Older versions are automatically
1223 detected and for those versions, this configuration option is ignored.
1224
1225 config CC_STACKPROTECTOR_ALL
1226 bool "Use stack-protector for all functions"
1227 depends on CC_STACKPROTECTOR
1228 help
1229 Normally, GCC only inserts the canary value protection for
1230 functions that use large-ish on-stack buffers. By enabling
1231 this option, GCC will be asked to do this for ALL functions.
1232
1233 source kernel/Kconfig.hz
1234
1235 config KEXEC
1236 bool "kexec system call"
1237 depends on X86_BIOS_REBOOT
1238 help
1239 kexec is a system call that implements the ability to shutdown your
1240 current kernel, and to start another kernel. It is like a reboot
1241 but it is independent of the system firmware. And like a reboot
1242 you can start any kernel with it, not just Linux.
1243
1244 The name comes from the similarity to the exec system call.
1245
1246 It is an ongoing process to be certain the hardware in a machine
1247 is properly shutdown, so do not be surprised if this code does not
1248 initially work for you. It may help to enable device hotplugging
1249 support. As of this writing the exact hardware interface is
1250 strongly in flux, so no good recommendation can be made.
1251
1252 config CRASH_DUMP
1253 bool "kernel crash dumps"
1254 depends on X86_64 || (X86_32 && HIGHMEM)
1255 help
1256 Generate crash dump after being started by kexec.
1257 This should be normally only set in special crash dump kernels
1258 which are loaded in the main kernel with kexec-tools into
1259 a specially reserved region and then later executed after
1260 a crash by kdump/kexec. The crash dump kernel must be compiled
1261 to a memory address not used by the main kernel or BIOS using
1262 PHYSICAL_START, or it must be built as a relocatable image
1263 (CONFIG_RELOCATABLE=y).
1264 For more details see Documentation/kdump/kdump.txt
1265
1266 config KEXEC_JUMP
1267 bool "kexec jump (EXPERIMENTAL)"
1268 depends on EXPERIMENTAL
1269 depends on KEXEC && HIBERNATION && X86_32
1270 help
1271 Jump between original kernel and kexeced kernel and invoke
1272 code in physical address mode via KEXEC
1273
1274 config PHYSICAL_START
1275 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1276 default "0x1000000" if X86_NUMAQ
1277 default "0x200000" if X86_64
1278 default "0x100000"
1279 help
1280 This gives the physical address where the kernel is loaded.
1281
1282 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1283 bzImage will decompress itself to above physical address and
1284 run from there. Otherwise, bzImage will run from the address where
1285 it has been loaded by the boot loader and will ignore above physical
1286 address.
1287
1288 In normal kdump cases one does not have to set/change this option
1289 as now bzImage can be compiled as a completely relocatable image
1290 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1291 address. This option is mainly useful for the folks who don't want
1292 to use a bzImage for capturing the crash dump and want to use a
1293 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1294 to be specifically compiled to run from a specific memory area
1295 (normally a reserved region) and this option comes handy.
1296
1297 So if you are using bzImage for capturing the crash dump, leave
1298 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1299 Otherwise if you plan to use vmlinux for capturing the crash dump
1300 change this value to start of the reserved region (Typically 16MB
1301 0x1000000). In other words, it can be set based on the "X" value as
1302 specified in the "crashkernel=YM@XM" command line boot parameter
1303 passed to the panic-ed kernel. Typically this parameter is set as
1304 crashkernel=64M@16M. Please take a look at
1305 Documentation/kdump/kdump.txt for more details about crash dumps.
1306
1307 Usage of bzImage for capturing the crash dump is recommended as
1308 one does not have to build two kernels. Same kernel can be used
1309 as production kernel and capture kernel. Above option should have
1310 gone away after relocatable bzImage support is introduced. But it
1311 is present because there are users out there who continue to use
1312 vmlinux for dump capture. This option should go away down the
1313 line.
1314
1315 Don't change this unless you know what you are doing.
1316
1317 config RELOCATABLE
1318 bool "Build a relocatable kernel (EXPERIMENTAL)"
1319 depends on EXPERIMENTAL
1320 help
1321 This builds a kernel image that retains relocation information
1322 so it can be loaded someplace besides the default 1MB.
1323 The relocations tend to make the kernel binary about 10% larger,
1324 but are discarded at runtime.
1325
1326 One use is for the kexec on panic case where the recovery kernel
1327 must live at a different physical address than the primary
1328 kernel.
1329
1330 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1331 it has been loaded at and the compile time physical address
1332 (CONFIG_PHYSICAL_START) is ignored.
1333
1334 config PHYSICAL_ALIGN
1335 hex
1336 prompt "Alignment value to which kernel should be aligned" if X86_32
1337 default "0x100000" if X86_32
1338 default "0x200000" if X86_64
1339 range 0x2000 0x400000
1340 help
1341 This value puts the alignment restrictions on physical address
1342 where kernel is loaded and run from. Kernel is compiled for an
1343 address which meets above alignment restriction.
1344
1345 If bootloader loads the kernel at a non-aligned address and
1346 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1347 address aligned to above value and run from there.
1348
1349 If bootloader loads the kernel at a non-aligned address and
1350 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1351 load address and decompress itself to the address it has been
1352 compiled for and run from there. The address for which kernel is
1353 compiled already meets above alignment restrictions. Hence the
1354 end result is that kernel runs from a physical address meeting
1355 above alignment restrictions.
1356
1357 Don't change this unless you know what you are doing.
1358
1359 config HOTPLUG_CPU
1360 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1361 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1362 ---help---
1363 Say Y here to experiment with turning CPUs off and on, and to
1364 enable suspend on SMP systems. CPUs can be controlled through
1365 /sys/devices/system/cpu.
1366 Say N if you want to disable CPU hotplug and don't need to
1367 suspend.
1368
1369 config COMPAT_VDSO
1370 def_bool y
1371 prompt "Compat VDSO support"
1372 depends on X86_32 || IA32_EMULATION
1373 help
1374 Map the 32-bit VDSO to the predictable old-style address too.
1375 ---help---
1376 Say N here if you are running a sufficiently recent glibc
1377 version (2.3.3 or later), to remove the high-mapped
1378 VDSO mapping and to exclusively use the randomized VDSO.
1379
1380 If unsure, say Y.
1381
1382 endmenu
1383
1384 config ARCH_ENABLE_MEMORY_HOTPLUG
1385 def_bool y
1386 depends on X86_64 || (X86_32 && HIGHMEM)
1387
1388 config HAVE_ARCH_EARLY_PFN_TO_NID
1389 def_bool X86_64
1390 depends on NUMA
1391
1392 menu "Power management options"
1393 depends on !X86_VOYAGER
1394
1395 config ARCH_HIBERNATION_HEADER
1396 def_bool y
1397 depends on X86_64 && HIBERNATION
1398
1399 source "kernel/power/Kconfig"
1400
1401 source "drivers/acpi/Kconfig"
1402
1403 config X86_APM_BOOT
1404 bool
1405 default y
1406 depends on APM || APM_MODULE
1407
1408 menuconfig APM
1409 tristate "APM (Advanced Power Management) BIOS support"
1410 depends on X86_32 && PM_SLEEP
1411 ---help---
1412 APM is a BIOS specification for saving power using several different
1413 techniques. This is mostly useful for battery powered laptops with
1414 APM compliant BIOSes. If you say Y here, the system time will be
1415 reset after a RESUME operation, the /proc/apm device will provide
1416 battery status information, and user-space programs will receive
1417 notification of APM "events" (e.g. battery status change).
1418
1419 If you select "Y" here, you can disable actual use of the APM
1420 BIOS by passing the "apm=off" option to the kernel at boot time.
1421
1422 Note that the APM support is almost completely disabled for
1423 machines with more than one CPU.
1424
1425 In order to use APM, you will need supporting software. For location
1426 and more information, read <file:Documentation/power/pm.txt> and the
1427 Battery Powered Linux mini-HOWTO, available from
1428 <http://www.tldp.org/docs.html#howto>.
1429
1430 This driver does not spin down disk drives (see the hdparm(8)
1431 manpage ("man 8 hdparm") for that), and it doesn't turn off
1432 VESA-compliant "green" monitors.
1433
1434 This driver does not support the TI 4000M TravelMate and the ACER
1435 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1436 desktop machines also don't have compliant BIOSes, and this driver
1437 may cause those machines to panic during the boot phase.
1438
1439 Generally, if you don't have a battery in your machine, there isn't
1440 much point in using this driver and you should say N. If you get
1441 random kernel OOPSes or reboots that don't seem to be related to
1442 anything, try disabling/enabling this option (or disabling/enabling
1443 APM in your BIOS).
1444
1445 Some other things you should try when experiencing seemingly random,
1446 "weird" problems:
1447
1448 1) make sure that you have enough swap space and that it is
1449 enabled.
1450 2) pass the "no-hlt" option to the kernel
1451 3) switch on floating point emulation in the kernel and pass
1452 the "no387" option to the kernel
1453 4) pass the "floppy=nodma" option to the kernel
1454 5) pass the "mem=4M" option to the kernel (thereby disabling
1455 all but the first 4 MB of RAM)
1456 6) make sure that the CPU is not over clocked.
1457 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1458 8) disable the cache from your BIOS settings
1459 9) install a fan for the video card or exchange video RAM
1460 10) install a better fan for the CPU
1461 11) exchange RAM chips
1462 12) exchange the motherboard.
1463
1464 To compile this driver as a module, choose M here: the
1465 module will be called apm.
1466
1467 if APM
1468
1469 config APM_IGNORE_USER_SUSPEND
1470 bool "Ignore USER SUSPEND"
1471 help
1472 This option will ignore USER SUSPEND requests. On machines with a
1473 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1474 series notebooks, it is necessary to say Y because of a BIOS bug.
1475
1476 config APM_DO_ENABLE
1477 bool "Enable PM at boot time"
1478 ---help---
1479 Enable APM features at boot time. From page 36 of the APM BIOS
1480 specification: "When disabled, the APM BIOS does not automatically
1481 power manage devices, enter the Standby State, enter the Suspend
1482 State, or take power saving steps in response to CPU Idle calls."
1483 This driver will make CPU Idle calls when Linux is idle (unless this
1484 feature is turned off -- see "Do CPU IDLE calls", below). This
1485 should always save battery power, but more complicated APM features
1486 will be dependent on your BIOS implementation. You may need to turn
1487 this option off if your computer hangs at boot time when using APM
1488 support, or if it beeps continuously instead of suspending. Turn
1489 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1490 T400CDT. This is off by default since most machines do fine without
1491 this feature.
1492
1493 config APM_CPU_IDLE
1494 bool "Make CPU Idle calls when idle"
1495 help
1496 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1497 On some machines, this can activate improved power savings, such as
1498 a slowed CPU clock rate, when the machine is idle. These idle calls
1499 are made after the idle loop has run for some length of time (e.g.,
1500 333 mS). On some machines, this will cause a hang at boot time or
1501 whenever the CPU becomes idle. (On machines with more than one CPU,
1502 this option does nothing.)
1503
1504 config APM_DISPLAY_BLANK
1505 bool "Enable console blanking using APM"
1506 help
1507 Enable console blanking using the APM. Some laptops can use this to
1508 turn off the LCD backlight when the screen blanker of the Linux
1509 virtual console blanks the screen. Note that this is only used by
1510 the virtual console screen blanker, and won't turn off the backlight
1511 when using the X Window system. This also doesn't have anything to
1512 do with your VESA-compliant power-saving monitor. Further, this
1513 option doesn't work for all laptops -- it might not turn off your
1514 backlight at all, or it might print a lot of errors to the console,
1515 especially if you are using gpm.
1516
1517 config APM_ALLOW_INTS
1518 bool "Allow interrupts during APM BIOS calls"
1519 help
1520 Normally we disable external interrupts while we are making calls to
1521 the APM BIOS as a measure to lessen the effects of a badly behaving
1522 BIOS implementation. The BIOS should reenable interrupts if it
1523 needs to. Unfortunately, some BIOSes do not -- especially those in
1524 many of the newer IBM Thinkpads. If you experience hangs when you
1525 suspend, try setting this to Y. Otherwise, say N.
1526
1527 config APM_REAL_MODE_POWER_OFF
1528 bool "Use real mode APM BIOS call to power off"
1529 help
1530 Use real mode APM BIOS calls to switch off the computer. This is
1531 a work-around for a number of buggy BIOSes. Switch this option on if
1532 your computer crashes instead of powering off properly.
1533
1534 endif # APM
1535
1536 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1537
1538 source "drivers/cpuidle/Kconfig"
1539
1540 endmenu
1541
1542
1543 menu "Bus options (PCI etc.)"
1544
1545 config PCI
1546 bool "PCI support"
1547 default y
1548 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1549 help
1550 Find out whether you have a PCI motherboard. PCI is the name of a
1551 bus system, i.e. the way the CPU talks to the other stuff inside
1552 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1553 VESA. If you have PCI, say Y, otherwise N.
1554
1555 choice
1556 prompt "PCI access mode"
1557 depends on X86_32 && PCI
1558 default PCI_GOANY
1559 ---help---
1560 On PCI systems, the BIOS can be used to detect the PCI devices and
1561 determine their configuration. However, some old PCI motherboards
1562 have BIOS bugs and may crash if this is done. Also, some embedded
1563 PCI-based systems don't have any BIOS at all. Linux can also try to
1564 detect the PCI hardware directly without using the BIOS.
1565
1566 With this option, you can specify how Linux should detect the
1567 PCI devices. If you choose "BIOS", the BIOS will be used,
1568 if you choose "Direct", the BIOS won't be used, and if you
1569 choose "MMConfig", then PCI Express MMCONFIG will be used.
1570 If you choose "Any", the kernel will try MMCONFIG, then the
1571 direct access method and falls back to the BIOS if that doesn't
1572 work. If unsure, go with the default, which is "Any".
1573
1574 config PCI_GOBIOS
1575 bool "BIOS"
1576
1577 config PCI_GOMMCONFIG
1578 bool "MMConfig"
1579
1580 config PCI_GODIRECT
1581 bool "Direct"
1582
1583 config PCI_GOOLPC
1584 bool "OLPC"
1585 depends on OLPC
1586
1587 config PCI_GOANY
1588 bool "Any"
1589
1590 endchoice
1591
1592 config PCI_BIOS
1593 def_bool y
1594 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1595
1596 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1597 config PCI_DIRECT
1598 def_bool y
1599 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1600
1601 config PCI_MMCONFIG
1602 def_bool y
1603 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1604
1605 config PCI_OLPC
1606 def_bool y
1607 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1608
1609 config PCI_DOMAINS
1610 def_bool y
1611 depends on PCI
1612
1613 config PCI_MMCONFIG
1614 bool "Support mmconfig PCI config space access"
1615 depends on X86_64 && PCI && ACPI
1616
1617 config DMAR
1618 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1619 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1620 help
1621 DMA remapping (DMAR) devices support enables independent address
1622 translations for Direct Memory Access (DMA) from devices.
1623 These DMA remapping devices are reported via ACPI tables
1624 and include PCI device scope covered by these DMA
1625 remapping devices.
1626
1627 config DMAR_GFX_WA
1628 def_bool y
1629 prompt "Support for Graphics workaround"
1630 depends on DMAR
1631 help
1632 Current Graphics drivers tend to use physical address
1633 for DMA and avoid using DMA APIs. Setting this config
1634 option permits the IOMMU driver to set a unity map for
1635 all the OS-visible memory. Hence the driver can continue
1636 to use physical addresses for DMA.
1637
1638 config DMAR_FLOPPY_WA
1639 def_bool y
1640 depends on DMAR
1641 help
1642 Floppy disk drivers are know to bypass DMA API calls
1643 thereby failing to work when IOMMU is enabled. This
1644 workaround will setup a 1:1 mapping for the first
1645 16M to make floppy (an ISA device) work.
1646
1647 source "drivers/pci/pcie/Kconfig"
1648
1649 source "drivers/pci/Kconfig"
1650
1651 # x86_64 have no ISA slots, but do have ISA-style DMA.
1652 config ISA_DMA_API
1653 def_bool y
1654
1655 if X86_32
1656
1657 config ISA
1658 bool "ISA support"
1659 depends on !X86_VOYAGER
1660 help
1661 Find out whether you have ISA slots on your motherboard. ISA is the
1662 name of a bus system, i.e. the way the CPU talks to the other stuff
1663 inside your box. Other bus systems are PCI, EISA, MicroChannel
1664 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1665 newer boards don't support it. If you have ISA, say Y, otherwise N.
1666
1667 config EISA
1668 bool "EISA support"
1669 depends on ISA
1670 ---help---
1671 The Extended Industry Standard Architecture (EISA) bus was
1672 developed as an open alternative to the IBM MicroChannel bus.
1673
1674 The EISA bus provided some of the features of the IBM MicroChannel
1675 bus while maintaining backward compatibility with cards made for
1676 the older ISA bus. The EISA bus saw limited use between 1988 and
1677 1995 when it was made obsolete by the PCI bus.
1678
1679 Say Y here if you are building a kernel for an EISA-based machine.
1680
1681 Otherwise, say N.
1682
1683 source "drivers/eisa/Kconfig"
1684
1685 config MCA
1686 bool "MCA support" if !X86_VOYAGER
1687 default y if X86_VOYAGER
1688 help
1689 MicroChannel Architecture is found in some IBM PS/2 machines and
1690 laptops. It is a bus system similar to PCI or ISA. See
1691 <file:Documentation/mca.txt> (and especially the web page given
1692 there) before attempting to build an MCA bus kernel.
1693
1694 source "drivers/mca/Kconfig"
1695
1696 config SCx200
1697 tristate "NatSemi SCx200 support"
1698 depends on !X86_VOYAGER
1699 help
1700 This provides basic support for National Semiconductor's
1701 (now AMD's) Geode processors. The driver probes for the
1702 PCI-IDs of several on-chip devices, so its a good dependency
1703 for other scx200_* drivers.
1704
1705 If compiled as a module, the driver is named scx200.
1706
1707 config SCx200HR_TIMER
1708 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1709 depends on SCx200 && GENERIC_TIME
1710 default y
1711 help
1712 This driver provides a clocksource built upon the on-chip
1713 27MHz high-resolution timer. Its also a workaround for
1714 NSC Geode SC-1100's buggy TSC, which loses time when the
1715 processor goes idle (as is done by the scheduler). The
1716 other workaround is idle=poll boot option.
1717
1718 config GEODE_MFGPT_TIMER
1719 def_bool y
1720 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1721 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1722 help
1723 This driver provides a clock event source based on the MFGPT
1724 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1725 MFGPTs have a better resolution and max interval than the
1726 generic PIT, and are suitable for use as high-res timers.
1727
1728 config OLPC
1729 bool "One Laptop Per Child support"
1730 default n
1731 help
1732 Add support for detecting the unique features of the OLPC
1733 XO hardware.
1734
1735 endif # X86_32
1736
1737 config K8_NB
1738 def_bool y
1739 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1740
1741 source "drivers/pcmcia/Kconfig"
1742
1743 source "drivers/pci/hotplug/Kconfig"
1744
1745 endmenu
1746
1747
1748 menu "Executable file formats / Emulations"
1749
1750 source "fs/Kconfig.binfmt"
1751
1752 config IA32_EMULATION
1753 bool "IA32 Emulation"
1754 depends on X86_64
1755 select COMPAT_BINFMT_ELF
1756 help
1757 Include code to run 32-bit programs under a 64-bit kernel. You should
1758 likely turn this on, unless you're 100% sure that you don't have any
1759 32-bit programs left.
1760
1761 config IA32_AOUT
1762 tristate "IA32 a.out support"
1763 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1764 help
1765 Support old a.out binaries in the 32bit emulation.
1766
1767 config COMPAT
1768 def_bool y
1769 depends on IA32_EMULATION
1770
1771 config COMPAT_FOR_U64_ALIGNMENT
1772 def_bool COMPAT
1773 depends on X86_64
1774
1775 config SYSVIPC_COMPAT
1776 def_bool y
1777 depends on X86_64 && COMPAT && SYSVIPC
1778
1779 endmenu
1780
1781
1782 source "net/Kconfig"
1783
1784 source "drivers/Kconfig"
1785
1786 source "drivers/firmware/Kconfig"
1787
1788 source "fs/Kconfig"
1789
1790 source "arch/x86/Kconfig.debug"
1791
1792 source "security/Kconfig"
1793
1794 source "crypto/Kconfig"
1795
1796 source "arch/x86/kvm/Kconfig"
1797
1798 source "lib/Kconfig"