xref: /linux/arch/x86/Kconfig (revision 2277ab4a1df50e05bc732fe9488d4e902bb8399a)
1# x86 configuration
2mainmenu "Linux Kernel Configuration for x86"
3
4# Select 32 or 64 bit
5config 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
12config X86_32
13	def_bool !64BIT
14
15config X86_64
16	def_bool 64BIT
17
18### Arch settings
19config X86
20	def_bool y
21	select HAVE_AOUT if X86_32
22	select HAVE_READQ
23	select HAVE_WRITEQ
24	select HAVE_UNSTABLE_SCHED_CLOCK
25	select HAVE_IDE
26	select HAVE_OPROFILE
27	select HAVE_IOREMAP_PROT
28	select HAVE_KPROBES
29	select ARCH_WANT_OPTIONAL_GPIOLIB
30	select ARCH_WANT_FRAME_POINTERS
31	select HAVE_DMA_ATTRS
32	select HAVE_KRETPROBES
33	select HAVE_FTRACE_MCOUNT_RECORD
34	select HAVE_DYNAMIC_FTRACE
35	select HAVE_FUNCTION_TRACER
36	select HAVE_FUNCTION_GRAPH_TRACER
37	select HAVE_FUNCTION_GRAPH_FP_TEST
38	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
39	select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
40	select HAVE_FTRACE_SYSCALLS
41	select HAVE_KVM
42	select HAVE_ARCH_KGDB
43	select HAVE_ARCH_TRACEHOOK
44	select HAVE_GENERIC_DMA_COHERENT if X86_32
45	select HAVE_EFFICIENT_UNALIGNED_ACCESS
46	select USER_STACKTRACE_SUPPORT
47	select HAVE_DMA_API_DEBUG
48	select HAVE_KERNEL_GZIP
49	select HAVE_KERNEL_BZIP2
50	select HAVE_KERNEL_LZMA
51	select HAVE_ARCH_KMEMCHECK
52
53config OUTPUT_FORMAT
54	string
55	default "elf32-i386" if X86_32
56	default "elf64-x86-64" if X86_64
57
58config ARCH_DEFCONFIG
59	string
60	default "arch/x86/configs/i386_defconfig" if X86_32
61	default "arch/x86/configs/x86_64_defconfig" if X86_64
62
63config GENERIC_TIME
64	def_bool y
65
66config GENERIC_CMOS_UPDATE
67	def_bool y
68
69config CLOCKSOURCE_WATCHDOG
70	def_bool y
71
72config GENERIC_CLOCKEVENTS
73	def_bool y
74
75config GENERIC_CLOCKEVENTS_BROADCAST
76	def_bool y
77	depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
78
79config LOCKDEP_SUPPORT
80	def_bool y
81
82config STACKTRACE_SUPPORT
83	def_bool y
84
85config HAVE_LATENCYTOP_SUPPORT
86	def_bool y
87
88config FAST_CMPXCHG_LOCAL
89	bool
90	default y
91
92config MMU
93	def_bool y
94
95config ZONE_DMA
96	def_bool y
97
98config SBUS
99	bool
100
101config GENERIC_ISA_DMA
102	def_bool y
103
104config GENERIC_IOMAP
105	def_bool y
106
107config GENERIC_BUG
108	def_bool y
109	depends on BUG
110	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
111
112config GENERIC_BUG_RELATIVE_POINTERS
113	bool
114
115config GENERIC_HWEIGHT
116	def_bool y
117
118config GENERIC_GPIO
119	bool
120
121config ARCH_MAY_HAVE_PC_FDC
122	def_bool y
123
124config RWSEM_GENERIC_SPINLOCK
125	def_bool !X86_XADD
126
127config RWSEM_XCHGADD_ALGORITHM
128	def_bool X86_XADD
129
130config ARCH_HAS_CPU_IDLE_WAIT
131	def_bool y
132
133config GENERIC_CALIBRATE_DELAY
134	def_bool y
135
136config GENERIC_TIME_VSYSCALL
137	bool
138	default X86_64
139
140config ARCH_HAS_CPU_RELAX
141	def_bool y
142
143config ARCH_HAS_DEFAULT_IDLE
144	def_bool y
145
146config ARCH_HAS_CACHE_LINE_SIZE
147	def_bool y
148
149config HAVE_SETUP_PER_CPU_AREA
150	def_bool y
151
152config HAVE_DYNAMIC_PER_CPU_AREA
153	def_bool y
154
155config HAVE_CPUMASK_OF_CPU_MAP
156	def_bool X86_64_SMP
157
158config ARCH_HIBERNATION_POSSIBLE
159	def_bool y
160
161config ARCH_SUSPEND_POSSIBLE
162	def_bool y
163
164config ZONE_DMA32
165	bool
166	default X86_64
167
168config ARCH_POPULATES_NODE_MAP
169	def_bool y
170
171config AUDIT_ARCH
172	bool
173	default X86_64
174
175config ARCH_SUPPORTS_OPTIMIZED_INLINING
176	def_bool y
177
178config ARCH_SUPPORTS_DEBUG_PAGEALLOC
179	def_bool y
180
181# Use the generic interrupt handling code in kernel/irq/:
182config GENERIC_HARDIRQS
183	bool
184	default y
185
186config GENERIC_HARDIRQS_NO__DO_IRQ
187       def_bool y
188
189config GENERIC_IRQ_PROBE
190	bool
191	default y
192
193config GENERIC_PENDING_IRQ
194	bool
195	depends on GENERIC_HARDIRQS && SMP
196	default y
197
198config USE_GENERIC_SMP_HELPERS
199	def_bool y
200	depends on SMP
201
202config X86_32_SMP
203	def_bool y
204	depends on X86_32 && SMP
205
206config X86_64_SMP
207	def_bool y
208	depends on X86_64 && SMP
209
210config X86_HT
211	bool
212	depends on SMP
213	default y
214
215config X86_TRAMPOLINE
216	bool
217	depends on SMP || (64BIT && ACPI_SLEEP)
218	default y
219
220config X86_32_LAZY_GS
221	def_bool y
222	depends on X86_32 && !CC_STACKPROTECTOR
223
224config KTIME_SCALAR
225	def_bool X86_32
226source "init/Kconfig"
227source "kernel/Kconfig.freezer"
228
229menu "Processor type and features"
230
231source "kernel/time/Kconfig"
232
233config SMP
234	bool "Symmetric multi-processing support"
235	---help---
236	  This enables support for systems with more than one CPU. If you have
237	  a system with only one CPU, like most personal computers, say N. If
238	  you have a system with more than one CPU, say Y.
239
240	  If you say N here, the kernel will run on single and multiprocessor
241	  machines, but will use only one CPU of a multiprocessor machine. If
242	  you say Y here, the kernel will run on many, but not all,
243	  singleprocessor machines. On a singleprocessor machine, the kernel
244	  will run faster if you say N here.
245
246	  Note that if you say Y here and choose architecture "586" or
247	  "Pentium" under "Processor family", the kernel will not work on 486
248	  architectures. Similarly, multiprocessor kernels for the "PPro"
249	  architecture may not work on all Pentium based boards.
250
251	  People using multiprocessor machines who say Y here should also say
252	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
253	  Management" code will be disabled if you say Y here.
254
255	  See also <file:Documentation/i386/IO-APIC.txt>,
256	  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
257	  <http://www.tldp.org/docs.html#howto>.
258
259	  If you don't know what to do here, say N.
260
261config X86_X2APIC
262	bool "Support x2apic"
263	depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
264	---help---
265	  This enables x2apic support on CPUs that have this feature.
266
267	  This allows 32-bit apic IDs (so it can support very large systems),
268	  and accesses the local apic via MSRs not via mmio.
269
270	  If you don't know what to do here, say N.
271
272config SPARSE_IRQ
273	bool "Support sparse irq numbering"
274	depends on PCI_MSI || HT_IRQ
275	---help---
276	  This enables support for sparse irqs. This is useful for distro
277	  kernels that want to define a high CONFIG_NR_CPUS value but still
278	  want to have low kernel memory footprint on smaller machines.
279
280	  ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
281	    out the irq_desc[] array in a more NUMA-friendly way. )
282
283	  If you don't know what to do here, say N.
284
285config NUMA_IRQ_DESC
286	def_bool y
287	depends on SPARSE_IRQ && NUMA
288
289config X86_MPPARSE
290	bool "Enable MPS table" if ACPI
291	default y
292	depends on X86_LOCAL_APIC
293	---help---
294	  For old smp systems that do not have proper acpi support. Newer systems
295	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
296
297config X86_BIGSMP
298	bool "Support for big SMP systems with more than 8 CPUs"
299	depends on X86_32 && SMP
300	---help---
301	  This option is needed for the systems that have more than 8 CPUs
302
303if X86_32
304config X86_EXTENDED_PLATFORM
305	bool "Support for extended (non-PC) x86 platforms"
306	default y
307	---help---
308	  If you disable this option then the kernel will only support
309	  standard PC platforms. (which covers the vast majority of
310	  systems out there.)
311
312	  If you enable this option then you'll be able to select support
313	  for the following (non-PC) 32 bit x86 platforms:
314		AMD Elan
315		NUMAQ (IBM/Sequent)
316		RDC R-321x SoC
317		SGI 320/540 (Visual Workstation)
318		Summit/EXA (IBM x440)
319		Unisys ES7000 IA32 series
320
321	  If you have one of these systems, or if you want to build a
322	  generic distribution kernel, say Y here - otherwise say N.
323endif
324
325if X86_64
326config X86_EXTENDED_PLATFORM
327	bool "Support for extended (non-PC) x86 platforms"
328	default y
329	---help---
330	  If you disable this option then the kernel will only support
331	  standard PC platforms. (which covers the vast majority of
332	  systems out there.)
333
334	  If you enable this option then you'll be able to select support
335	  for the following (non-PC) 64 bit x86 platforms:
336		ScaleMP vSMP
337		SGI Ultraviolet
338
339	  If you have one of these systems, or if you want to build a
340	  generic distribution kernel, say Y here - otherwise say N.
341endif
342# This is an alphabetically sorted list of 64 bit extended platforms
343# Please maintain the alphabetic order if and when there are additions
344
345config X86_VSMP
346	bool "ScaleMP vSMP"
347	select PARAVIRT
348	depends on X86_64 && PCI
349	depends on X86_EXTENDED_PLATFORM
350	---help---
351	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
352	  supposed to run on these EM64T-based machines.  Only choose this option
353	  if you have one of these machines.
354
355config X86_UV
356	bool "SGI Ultraviolet"
357	depends on X86_64
358	depends on X86_EXTENDED_PLATFORM
359	depends on NUMA
360	depends on X86_X2APIC
361	---help---
362	  This option is needed in order to support SGI Ultraviolet systems.
363	  If you don't have one of these, you should say N here.
364
365# Following is an alphabetically sorted list of 32 bit extended platforms
366# Please maintain the alphabetic order if and when there are additions
367
368config X86_ELAN
369	bool "AMD Elan"
370	depends on X86_32
371	depends on X86_EXTENDED_PLATFORM
372	---help---
373	  Select this for an AMD Elan processor.
374
375	  Do not use this option for K6/Athlon/Opteron processors!
376
377	  If unsure, choose "PC-compatible" instead.
378
379config X86_RDC321X
380	bool "RDC R-321x SoC"
381	depends on X86_32
382	depends on X86_EXTENDED_PLATFORM
383	select M486
384	select X86_REBOOTFIXUPS
385	---help---
386	  This option is needed for RDC R-321x system-on-chip, also known
387	  as R-8610-(G).
388	  If you don't have one of these chips, you should say N here.
389
390config X86_32_NON_STANDARD
391	bool "Support non-standard 32-bit SMP architectures"
392	depends on X86_32 && SMP
393	depends on X86_EXTENDED_PLATFORM
394	---help---
395	  This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
396	  subarchitectures.  It is intended for a generic binary kernel.
397	  if you select them all, kernel will probe it one by one. and will
398	  fallback to default.
399
400# Alphabetically sorted list of Non standard 32 bit platforms
401
402config X86_NUMAQ
403	bool "NUMAQ (IBM/Sequent)"
404	depends on X86_32_NON_STANDARD
405	select NUMA
406	select X86_MPPARSE
407	---help---
408	  This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
409	  NUMA multiquad box. This changes the way that processors are
410	  bootstrapped, and uses Clustered Logical APIC addressing mode instead
411	  of Flat Logical.  You will need a new lynxer.elf file to flash your
412	  firmware with - send email to <Martin.Bligh@us.ibm.com>.
413
414config X86_VISWS
415	bool "SGI 320/540 (Visual Workstation)"
416	depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
417	depends on X86_32_NON_STANDARD
418	---help---
419	  The SGI Visual Workstation series is an IA32-based workstation
420	  based on SGI systems chips with some legacy PC hardware attached.
421
422	  Say Y here to create a kernel to run on the SGI 320 or 540.
423
424	  A kernel compiled for the Visual Workstation will run on general
425	  PCs as well. See <file:Documentation/sgi-visws.txt> for details.
426
427config X86_SUMMIT
428	bool "Summit/EXA (IBM x440)"
429	depends on X86_32_NON_STANDARD
430	---help---
431	  This option is needed for IBM systems that use the Summit/EXA chipset.
432	  In particular, it is needed for the x440.
433
434config X86_ES7000
435	bool "Unisys ES7000 IA32 series"
436	depends on X86_32_NON_STANDARD && X86_BIGSMP
437	---help---
438	  Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
439	  supposed to run on an IA32-based Unisys ES7000 system.
440
441config SCHED_OMIT_FRAME_POINTER
442	def_bool y
443	prompt "Single-depth WCHAN output"
444	depends on X86
445	---help---
446	  Calculate simpler /proc/<PID>/wchan values. If this option
447	  is disabled then wchan values will recurse back to the
448	  caller function. This provides more accurate wchan values,
449	  at the expense of slightly more scheduling overhead.
450
451	  If in doubt, say "Y".
452
453menuconfig PARAVIRT_GUEST
454	bool "Paravirtualized guest support"
455	---help---
456	  Say Y here to get to see options related to running Linux under
457	  various hypervisors.  This option alone does not add any kernel code.
458
459	  If you say N, all options in this submenu will be skipped and disabled.
460
461if PARAVIRT_GUEST
462
463source "arch/x86/xen/Kconfig"
464
465config VMI
466	bool "VMI Guest support"
467	select PARAVIRT
468	depends on X86_32
469	---help---
470	  VMI provides a paravirtualized interface to the VMware ESX server
471	  (it could be used by other hypervisors in theory too, but is not
472	  at the moment), by linking the kernel to a GPL-ed ROM module
473	  provided by the hypervisor.
474
475config KVM_CLOCK
476	bool "KVM paravirtualized clock"
477	select PARAVIRT
478	select PARAVIRT_CLOCK
479	---help---
480	  Turning on this option will allow you to run a paravirtualized clock
481	  when running over the KVM hypervisor. Instead of relying on a PIT
482	  (or probably other) emulation by the underlying device model, the host
483	  provides the guest with timing infrastructure such as time of day, and
484	  system time
485
486config KVM_GUEST
487	bool "KVM Guest support"
488	select PARAVIRT
489	---help---
490	  This option enables various optimizations for running under the KVM
491	  hypervisor.
492
493source "arch/x86/lguest/Kconfig"
494
495config PARAVIRT
496	bool "Enable paravirtualization code"
497	---help---
498	  This changes the kernel so it can modify itself when it is run
499	  under a hypervisor, potentially improving performance significantly
500	  over full virtualization.  However, when run without a hypervisor
501	  the kernel is theoretically slower and slightly larger.
502
503config PARAVIRT_SPINLOCKS
504	bool "Paravirtualization layer for spinlocks"
505	depends on PARAVIRT && SMP && EXPERIMENTAL
506	---help---
507	  Paravirtualized spinlocks allow a pvops backend to replace the
508	  spinlock implementation with something virtualization-friendly
509	  (for example, block the virtual CPU rather than spinning).
510
511	  Unfortunately the downside is an up to 5% performance hit on
512	  native kernels, with various workloads.
513
514	  If you are unsure how to answer this question, answer N.
515
516config PARAVIRT_CLOCK
517	bool
518	default n
519
520endif
521
522config PARAVIRT_DEBUG
523	bool "paravirt-ops debugging"
524	depends on PARAVIRT && DEBUG_KERNEL
525	---help---
526	  Enable to debug paravirt_ops internals.  Specifically, BUG if
527	  a paravirt_op is missing when it is called.
528
529config MEMTEST
530	bool "Memtest"
531	---help---
532	  This option adds a kernel parameter 'memtest', which allows memtest
533	  to be set.
534	        memtest=0, mean disabled; -- default
535	        memtest=1, mean do 1 test pattern;
536	        ...
537	        memtest=4, mean do 4 test patterns.
538	  If you are unsure how to answer this question, answer N.
539
540config X86_SUMMIT_NUMA
541	def_bool y
542	depends on X86_32 && NUMA && X86_32_NON_STANDARD
543
544config X86_CYCLONE_TIMER
545	def_bool y
546	depends on X86_32_NON_STANDARD
547
548source "arch/x86/Kconfig.cpu"
549
550config HPET_TIMER
551	def_bool X86_64
552	prompt "HPET Timer Support" if X86_32
553	---help---
554	  Use the IA-PC HPET (High Precision Event Timer) to manage
555	  time in preference to the PIT and RTC, if a HPET is
556	  present.
557	  HPET is the next generation timer replacing legacy 8254s.
558	  The HPET provides a stable time base on SMP
559	  systems, unlike the TSC, but it is more expensive to access,
560	  as it is off-chip.  You can find the HPET spec at
561	  <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
562
563	  You can safely choose Y here.  However, HPET will only be
564	  activated if the platform and the BIOS support this feature.
565	  Otherwise the 8254 will be used for timing services.
566
567	  Choose N to continue using the legacy 8254 timer.
568
569config HPET_EMULATE_RTC
570	def_bool y
571	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
572
573# Mark as embedded because too many people got it wrong.
574# The code disables itself when not needed.
575config DMI
576	default y
577	bool "Enable DMI scanning" if EMBEDDED
578	---help---
579	  Enabled scanning of DMI to identify machine quirks. Say Y
580	  here unless you have verified that your setup is not
581	  affected by entries in the DMI blacklist. Required by PNP
582	  BIOS code.
583
584config GART_IOMMU
585	bool "GART IOMMU support" if EMBEDDED
586	default y
587	select SWIOTLB
588	select AGP
589	depends on X86_64 && PCI
590	---help---
591	  Support for full DMA access of devices with 32bit memory access only
592	  on systems with more than 3GB. This is usually needed for USB,
593	  sound, many IDE/SATA chipsets and some other devices.
594	  Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
595	  based hardware IOMMU and a software bounce buffer based IOMMU used
596	  on Intel systems and as fallback.
597	  The code is only active when needed (enough memory and limited
598	  device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
599	  too.
600
601config CALGARY_IOMMU
602	bool "IBM Calgary IOMMU support"
603	select SWIOTLB
604	depends on X86_64 && PCI && EXPERIMENTAL
605	---help---
606	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
607	  systems. Needed to run systems with more than 3GB of memory
608	  properly with 32-bit PCI devices that do not support DAC
609	  (Double Address Cycle). Calgary also supports bus level
610	  isolation, where all DMAs pass through the IOMMU.  This
611	  prevents them from going anywhere except their intended
612	  destination. This catches hard-to-find kernel bugs and
613	  mis-behaving drivers and devices that do not use the DMA-API
614	  properly to set up their DMA buffers.  The IOMMU can be
615	  turned off at boot time with the iommu=off parameter.
616	  Normally the kernel will make the right choice by itself.
617	  If unsure, say Y.
618
619config CALGARY_IOMMU_ENABLED_BY_DEFAULT
620	def_bool y
621	prompt "Should Calgary be enabled by default?"
622	depends on CALGARY_IOMMU
623	---help---
624	  Should Calgary be enabled by default? if you choose 'y', Calgary
625	  will be used (if it exists). If you choose 'n', Calgary will not be
626	  used even if it exists. If you choose 'n' and would like to use
627	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
628	  If unsure, say Y.
629
630config AMD_IOMMU
631	bool "AMD IOMMU support"
632	select SWIOTLB
633	select PCI_MSI
634	depends on X86_64 && PCI && ACPI
635	---help---
636	  With this option you can enable support for AMD IOMMU hardware in
637	  your system. An IOMMU is a hardware component which provides
638	  remapping of DMA memory accesses from devices. With an AMD IOMMU you
639	  can isolate the the DMA memory of different devices and protect the
640	  system from misbehaving device drivers or hardware.
641
642	  You can find out if your system has an AMD IOMMU if you look into
643	  your BIOS for an option to enable it or if you have an IVRS ACPI
644	  table.
645
646config AMD_IOMMU_STATS
647	bool "Export AMD IOMMU statistics to debugfs"
648	depends on AMD_IOMMU
649	select DEBUG_FS
650	---help---
651	  This option enables code in the AMD IOMMU driver to collect various
652	  statistics about whats happening in the driver and exports that
653	  information to userspace via debugfs.
654	  If unsure, say N.
655
656# need this always selected by IOMMU for the VIA workaround
657config SWIOTLB
658	def_bool y if X86_64
659	---help---
660	  Support for software bounce buffers used on x86-64 systems
661	  which don't have a hardware IOMMU (e.g. the current generation
662	  of Intel's x86-64 CPUs). Using this PCI devices which can only
663	  access 32-bits of memory can be used on systems with more than
664	  3 GB of memory. If unsure, say Y.
665
666config IOMMU_HELPER
667	def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
668
669config IOMMU_API
670	def_bool (AMD_IOMMU || DMAR)
671
672config MAXSMP
673	bool "Configure Maximum number of SMP Processors and NUMA Nodes"
674	depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
675	select CPUMASK_OFFSTACK
676	default n
677	---help---
678	  Configure maximum number of CPUS and NUMA Nodes for this architecture.
679	  If unsure, say N.
680
681config NR_CPUS
682	int "Maximum number of CPUs" if SMP && !MAXSMP
683	range 2 8 if SMP && X86_32 && !X86_BIGSMP
684	range 2 512 if SMP && !MAXSMP
685	default "1" if !SMP
686	default "4096" if MAXSMP
687	default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
688	default "8" if SMP
689	---help---
690	  This allows you to specify the maximum number of CPUs which this
691	  kernel will support.  The maximum supported value is 512 and the
692	  minimum value which makes sense is 2.
693
694	  This is purely to save memory - each supported CPU adds
695	  approximately eight kilobytes to the kernel image.
696
697config SCHED_SMT
698	bool "SMT (Hyperthreading) scheduler support"
699	depends on X86_HT
700	---help---
701	  SMT scheduler support improves the CPU scheduler's decision making
702	  when dealing with Intel Pentium 4 chips with HyperThreading at a
703	  cost of slightly increased overhead in some places. If unsure say
704	  N here.
705
706config SCHED_MC
707	def_bool y
708	prompt "Multi-core scheduler support"
709	depends on X86_HT
710	---help---
711	  Multi-core scheduler support improves the CPU scheduler's decision
712	  making when dealing with multi-core CPU chips at a cost of slightly
713	  increased overhead in some places. If unsure say N here.
714
715source "kernel/Kconfig.preempt"
716
717config X86_UP_APIC
718	bool "Local APIC support on uniprocessors"
719	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
720	---help---
721	  A local APIC (Advanced Programmable Interrupt Controller) is an
722	  integrated interrupt controller in the CPU. If you have a single-CPU
723	  system which has a processor with a local APIC, you can say Y here to
724	  enable and use it. If you say Y here even though your machine doesn't
725	  have a local APIC, then the kernel will still run with no slowdown at
726	  all. The local APIC supports CPU-generated self-interrupts (timer,
727	  performance counters), and the NMI watchdog which detects hard
728	  lockups.
729
730config X86_UP_IOAPIC
731	bool "IO-APIC support on uniprocessors"
732	depends on X86_UP_APIC
733	---help---
734	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
735	  SMP-capable replacement for PC-style interrupt controllers. Most
736	  SMP systems and many recent uniprocessor systems have one.
737
738	  If you have a single-CPU system with an IO-APIC, you can say Y here
739	  to use it. If you say Y here even though your machine doesn't have
740	  an IO-APIC, then the kernel will still run with no slowdown at all.
741
742config X86_LOCAL_APIC
743	def_bool y
744	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
745	select HAVE_PERF_COUNTERS if (!M386 && !M486)
746
747config X86_IO_APIC
748	def_bool y
749	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
750
751config X86_VISWS_APIC
752	def_bool y
753	depends on X86_32 && X86_VISWS
754
755config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
756	bool "Reroute for broken boot IRQs"
757	default n
758	depends on X86_IO_APIC
759	---help---
760	  This option enables a workaround that fixes a source of
761	  spurious interrupts. This is recommended when threaded
762	  interrupt handling is used on systems where the generation of
763	  superfluous "boot interrupts" cannot be disabled.
764
765	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
766	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
767	  kernel does during interrupt handling). On chipsets where this
768	  boot IRQ generation cannot be disabled, this workaround keeps
769	  the original IRQ line masked so that only the equivalent "boot
770	  IRQ" is delivered to the CPUs. The workaround also tells the
771	  kernel to set up the IRQ handler on the boot IRQ line. In this
772	  way only one interrupt is delivered to the kernel. Otherwise
773	  the spurious second interrupt may cause the kernel to bring
774	  down (vital) interrupt lines.
775
776	  Only affects "broken" chipsets. Interrupt sharing may be
777	  increased on these systems.
778
779config X86_MCE
780	bool "Machine Check Exception"
781	---help---
782	  Machine Check Exception support allows the processor to notify the
783	  kernel if it detects a problem (e.g. overheating, component failure).
784	  The action the kernel takes depends on the severity of the problem,
785	  ranging from a warning message on the console, to halting the machine.
786	  Your processor must be a Pentium or newer to support this - check the
787	  flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
788	  have a design flaw which leads to false MCE events - hence MCE is
789	  disabled on all P5 processors, unless explicitly enabled with "mce"
790	  as a boot argument.  Similarly, if MCE is built in and creates a
791	  problem on some new non-standard machine, you can boot with "nomce"
792	  to disable it.  MCE support simply ignores non-MCE processors like
793	  the 386 and 486, so nearly everyone can say Y here.
794
795config X86_OLD_MCE
796	depends on X86_32 && X86_MCE
797	bool "Use legacy machine check code (will go away)"
798	default n
799	select X86_ANCIENT_MCE
800	---help---
801	  Use the old i386 machine check code. This is merely intended for
802	  testing in a transition period. Try this if you run into any machine
803	  check related software problems, but report the problem to
804	  linux-kernel.  When in doubt say no.
805
806config X86_NEW_MCE
807	depends on X86_MCE
808	bool
809	default y if (!X86_OLD_MCE && X86_32) || X86_64
810
811config X86_MCE_INTEL
812	def_bool y
813	prompt "Intel MCE features"
814	depends on X86_NEW_MCE && X86_LOCAL_APIC
815	---help---
816	   Additional support for intel specific MCE features such as
817	   the thermal monitor.
818
819config X86_MCE_AMD
820	def_bool y
821	prompt "AMD MCE features"
822	depends on X86_NEW_MCE && X86_LOCAL_APIC
823	---help---
824	   Additional support for AMD specific MCE features such as
825	   the DRAM Error Threshold.
826
827config X86_ANCIENT_MCE
828	def_bool n
829	depends on X86_32
830	prompt "Support for old Pentium 5 / WinChip machine checks"
831	---help---
832	  Include support for machine check handling on old Pentium 5 or WinChip
833	  systems. These typically need to be enabled explicitely on the command
834	  line.
835
836config X86_MCE_THRESHOLD
837	depends on X86_MCE_AMD || X86_MCE_INTEL
838	bool
839	default y
840
841config X86_MCE_INJECT
842	depends on X86_NEW_MCE
843	tristate "Machine check injector support"
844	---help---
845	  Provide support for injecting machine checks for testing purposes.
846	  If you don't know what a machine check is and you don't do kernel
847	  QA it is safe to say n.
848
849config X86_MCE_NONFATAL
850	tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
851	depends on X86_OLD_MCE
852	---help---
853	  Enabling this feature starts a timer that triggers every 5 seconds which
854	  will look at the machine check registers to see if anything happened.
855	  Non-fatal problems automatically get corrected (but still logged).
856	  Disable this if you don't want to see these messages.
857	  Seeing the messages this option prints out may be indicative of dying
858	  or out-of-spec (ie, overclocked) hardware.
859	  This option only does something on certain CPUs.
860	  (AMD Athlon/Duron and Intel Pentium 4)
861
862config X86_MCE_P4THERMAL
863	bool "check for P4 thermal throttling interrupt."
864	depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
865	---help---
866	  Enabling this feature will cause a message to be printed when the P4
867	  enters thermal throttling.
868
869config X86_THERMAL_VECTOR
870	def_bool y
871	depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
872
873config VM86
874	bool "Enable VM86 support" if EMBEDDED
875	default y
876	depends on X86_32
877	---help---
878	  This option is required by programs like DOSEMU to run 16-bit legacy
879	  code on X86 processors. It also may be needed by software like
880	  XFree86 to initialize some video cards via BIOS. Disabling this
881	  option saves about 6k.
882
883config TOSHIBA
884	tristate "Toshiba Laptop support"
885	depends on X86_32
886	---help---
887	  This adds a driver to safely access the System Management Mode of
888	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
889	  not work on models with a Phoenix BIOS. The System Management Mode
890	  is used to set the BIOS and power saving options on Toshiba portables.
891
892	  For information on utilities to make use of this driver see the
893	  Toshiba Linux utilities web site at:
894	  <http://www.buzzard.org.uk/toshiba/>.
895
896	  Say Y if you intend to run this kernel on a Toshiba portable.
897	  Say N otherwise.
898
899config I8K
900	tristate "Dell laptop support"
901	---help---
902	  This adds a driver to safely access the System Management Mode
903	  of the CPU on the Dell Inspiron 8000. The System Management Mode
904	  is used to read cpu temperature and cooling fan status and to
905	  control the fans on the I8K portables.
906
907	  This driver has been tested only on the Inspiron 8000 but it may
908	  also work with other Dell laptops. You can force loading on other
909	  models by passing the parameter `force=1' to the module. Use at
910	  your own risk.
911
912	  For information on utilities to make use of this driver see the
913	  I8K Linux utilities web site at:
914	  <http://people.debian.org/~dz/i8k/>
915
916	  Say Y if you intend to run this kernel on a Dell Inspiron 8000.
917	  Say N otherwise.
918
919config X86_REBOOTFIXUPS
920	bool "Enable X86 board specific fixups for reboot"
921	depends on X86_32
922	---help---
923	  This enables chipset and/or board specific fixups to be done
924	  in order to get reboot to work correctly. This is only needed on
925	  some combinations of hardware and BIOS. The symptom, for which
926	  this config is intended, is when reboot ends with a stalled/hung
927	  system.
928
929	  Currently, the only fixup is for the Geode machines using
930	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
931
932	  Say Y if you want to enable the fixup. Currently, it's safe to
933	  enable this option even if you don't need it.
934	  Say N otherwise.
935
936config MICROCODE
937	tristate "/dev/cpu/microcode - microcode support"
938	select FW_LOADER
939	---help---
940	  If you say Y here, you will be able to update the microcode on
941	  certain Intel and AMD processors. The Intel support is for the
942	  IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
943	  Pentium 4, Xeon etc. The AMD support is for family 0x10 and
944	  0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
945	  You will obviously need the actual microcode binary data itself
946	  which is not shipped with the Linux kernel.
947
948	  This option selects the general module only, you need to select
949	  at least one vendor specific module as well.
950
951	  To compile this driver as a module, choose M here: the
952	  module will be called microcode.
953
954config MICROCODE_INTEL
955	bool "Intel microcode patch loading support"
956	depends on MICROCODE
957	default MICROCODE
958	select FW_LOADER
959	---help---
960	  This options enables microcode patch loading support for Intel
961	  processors.
962
963	  For latest news and information on obtaining all the required
964	  Intel ingredients for this driver, check:
965	  <http://www.urbanmyth.org/microcode/>.
966
967config MICROCODE_AMD
968	bool "AMD microcode patch loading support"
969	depends on MICROCODE
970	select FW_LOADER
971	---help---
972	  If you select this option, microcode patch loading support for AMD
973	  processors will be enabled.
974
975config MICROCODE_OLD_INTERFACE
976	def_bool y
977	depends on MICROCODE
978
979config X86_MSR
980	tristate "/dev/cpu/*/msr - Model-specific register support"
981	---help---
982	  This device gives privileged processes access to the x86
983	  Model-Specific Registers (MSRs).  It is a character device with
984	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
985	  MSR accesses are directed to a specific CPU on multi-processor
986	  systems.
987
988config X86_CPUID
989	tristate "/dev/cpu/*/cpuid - CPU information support"
990	---help---
991	  This device gives processes access to the x86 CPUID instruction to
992	  be executed on a specific processor.  It is a character device
993	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
994	  /dev/cpu/31/cpuid.
995
996config X86_CPU_DEBUG
997	tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
998	---help---
999	  If you select this option, this will provide various x86 CPUs
1000	  information through debugfs.
1001
1002choice
1003	prompt "High Memory Support"
1004	default HIGHMEM4G if !X86_NUMAQ
1005	default HIGHMEM64G if X86_NUMAQ
1006	depends on X86_32
1007
1008config NOHIGHMEM
1009	bool "off"
1010	depends on !X86_NUMAQ
1011	---help---
1012	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1013	  However, the address space of 32-bit x86 processors is only 4
1014	  Gigabytes large. That means that, if you have a large amount of
1015	  physical memory, not all of it can be "permanently mapped" by the
1016	  kernel. The physical memory that's not permanently mapped is called
1017	  "high memory".
1018
1019	  If you are compiling a kernel which will never run on a machine with
1020	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1021	  choice and suitable for most users). This will result in a "3GB/1GB"
1022	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1023	  space and the remaining part of the 4GB virtual memory space is used
1024	  by the kernel to permanently map as much physical memory as
1025	  possible.
1026
1027	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1028	  answer "4GB" here.
1029
1030	  If more than 4 Gigabytes is used then answer "64GB" here. This
1031	  selection turns Intel PAE (Physical Address Extension) mode on.
1032	  PAE implements 3-level paging on IA32 processors. PAE is fully
1033	  supported by Linux, PAE mode is implemented on all recent Intel
1034	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1035	  then the kernel will not boot on CPUs that don't support PAE!
1036
1037	  The actual amount of total physical memory will either be
1038	  auto detected or can be forced by using a kernel command line option
1039	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1040	  your boot loader (lilo or loadlin) about how to pass options to the
1041	  kernel at boot time.)
1042
1043	  If unsure, say "off".
1044
1045config HIGHMEM4G
1046	bool "4GB"
1047	depends on !X86_NUMAQ
1048	---help---
1049	  Select this if you have a 32-bit processor and between 1 and 4
1050	  gigabytes of physical RAM.
1051
1052config HIGHMEM64G
1053	bool "64GB"
1054	depends on !M386 && !M486
1055	select X86_PAE
1056	---help---
1057	  Select this if you have a 32-bit processor and more than 4
1058	  gigabytes of physical RAM.
1059
1060endchoice
1061
1062choice
1063	depends on EXPERIMENTAL
1064	prompt "Memory split" if EMBEDDED
1065	default VMSPLIT_3G
1066	depends on X86_32
1067	---help---
1068	  Select the desired split between kernel and user memory.
1069
1070	  If the address range available to the kernel is less than the
1071	  physical memory installed, the remaining memory will be available
1072	  as "high memory". Accessing high memory is a little more costly
1073	  than low memory, as it needs to be mapped into the kernel first.
1074	  Note that increasing the kernel address space limits the range
1075	  available to user programs, making the address space there
1076	  tighter.  Selecting anything other than the default 3G/1G split
1077	  will also likely make your kernel incompatible with binary-only
1078	  kernel modules.
1079
1080	  If you are not absolutely sure what you are doing, leave this
1081	  option alone!
1082
1083	config VMSPLIT_3G
1084		bool "3G/1G user/kernel split"
1085	config VMSPLIT_3G_OPT
1086		depends on !X86_PAE
1087		bool "3G/1G user/kernel split (for full 1G low memory)"
1088	config VMSPLIT_2G
1089		bool "2G/2G user/kernel split"
1090	config VMSPLIT_2G_OPT
1091		depends on !X86_PAE
1092		bool "2G/2G user/kernel split (for full 2G low memory)"
1093	config VMSPLIT_1G
1094		bool "1G/3G user/kernel split"
1095endchoice
1096
1097config PAGE_OFFSET
1098	hex
1099	default 0xB0000000 if VMSPLIT_3G_OPT
1100	default 0x80000000 if VMSPLIT_2G
1101	default 0x78000000 if VMSPLIT_2G_OPT
1102	default 0x40000000 if VMSPLIT_1G
1103	default 0xC0000000
1104	depends on X86_32
1105
1106config HIGHMEM
1107	def_bool y
1108	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1109
1110config X86_PAE
1111	bool "PAE (Physical Address Extension) Support"
1112	depends on X86_32 && !HIGHMEM4G
1113	---help---
1114	  PAE is required for NX support, and furthermore enables
1115	  larger swapspace support for non-overcommit purposes. It
1116	  has the cost of more pagetable lookup overhead, and also
1117	  consumes more pagetable space per process.
1118
1119config ARCH_PHYS_ADDR_T_64BIT
1120	def_bool X86_64 || X86_PAE
1121
1122config DIRECT_GBPAGES
1123	bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1124	default y
1125	depends on X86_64
1126	---help---
1127	  Allow the kernel linear mapping to use 1GB pages on CPUs that
1128	  support it. This can improve the kernel's performance a tiny bit by
1129	  reducing TLB pressure. If in doubt, say "Y".
1130
1131# Common NUMA Features
1132config NUMA
1133	bool "Numa Memory Allocation and Scheduler Support"
1134	depends on SMP
1135	depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1136	default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1137	---help---
1138	  Enable NUMA (Non Uniform Memory Access) support.
1139
1140	  The kernel will try to allocate memory used by a CPU on the
1141	  local memory controller of the CPU and add some more
1142	  NUMA awareness to the kernel.
1143
1144	  For 64-bit this is recommended if the system is Intel Core i7
1145	  (or later), AMD Opteron, or EM64T NUMA.
1146
1147	  For 32-bit this is only needed on (rare) 32-bit-only platforms
1148	  that support NUMA topologies, such as NUMAQ / Summit, or if you
1149	  boot a 32-bit kernel on a 64-bit NUMA platform.
1150
1151	  Otherwise, you should say N.
1152
1153comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1154	depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1155
1156config K8_NUMA
1157	def_bool y
1158	prompt "Old style AMD Opteron NUMA detection"
1159	depends on X86_64 && NUMA && PCI
1160	---help---
1161	  Enable K8 NUMA node topology detection.  You should say Y here if
1162	  you have a multi processor AMD K8 system. This uses an old
1163	  method to read the NUMA configuration directly from the builtin
1164	  Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1165	  instead, which also takes priority if both are compiled in.
1166
1167config X86_64_ACPI_NUMA
1168	def_bool y
1169	prompt "ACPI NUMA detection"
1170	depends on X86_64 && NUMA && ACPI && PCI
1171	select ACPI_NUMA
1172	---help---
1173	  Enable ACPI SRAT based node topology detection.
1174
1175# Some NUMA nodes have memory ranges that span
1176# other nodes.  Even though a pfn is valid and
1177# between a node's start and end pfns, it may not
1178# reside on that node.  See memmap_init_zone()
1179# for details.
1180config NODES_SPAN_OTHER_NODES
1181	def_bool y
1182	depends on X86_64_ACPI_NUMA
1183
1184config NUMA_EMU
1185	bool "NUMA emulation"
1186	depends on X86_64 && NUMA
1187	---help---
1188	  Enable NUMA emulation. A flat machine will be split
1189	  into virtual nodes when booted with "numa=fake=N", where N is the
1190	  number of nodes. This is only useful for debugging.
1191
1192config NODES_SHIFT
1193	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1194	range 1 9
1195	default "9" if MAXSMP
1196	default "6" if X86_64
1197	default "4" if X86_NUMAQ
1198	default "3"
1199	depends on NEED_MULTIPLE_NODES
1200	---help---
1201	  Specify the maximum number of NUMA Nodes available on the target
1202	  system.  Increases memory reserved to accommodate various tables.
1203
1204config HAVE_ARCH_BOOTMEM
1205	def_bool y
1206	depends on X86_32 && NUMA
1207
1208config ARCH_HAVE_MEMORY_PRESENT
1209	def_bool y
1210	depends on X86_32 && DISCONTIGMEM
1211
1212config NEED_NODE_MEMMAP_SIZE
1213	def_bool y
1214	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1215
1216config HAVE_ARCH_ALLOC_REMAP
1217	def_bool y
1218	depends on X86_32 && NUMA
1219
1220config ARCH_FLATMEM_ENABLE
1221	def_bool y
1222	depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1223
1224config ARCH_DISCONTIGMEM_ENABLE
1225	def_bool y
1226	depends on NUMA && X86_32
1227
1228config ARCH_DISCONTIGMEM_DEFAULT
1229	def_bool y
1230	depends on NUMA && X86_32
1231
1232config ARCH_SPARSEMEM_DEFAULT
1233	def_bool y
1234	depends on X86_64
1235
1236config ARCH_SPARSEMEM_ENABLE
1237	def_bool y
1238	depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1239	select SPARSEMEM_STATIC if X86_32
1240	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1241
1242config ARCH_SELECT_MEMORY_MODEL
1243	def_bool y
1244	depends on ARCH_SPARSEMEM_ENABLE
1245
1246config ARCH_MEMORY_PROBE
1247	def_bool X86_64
1248	depends on MEMORY_HOTPLUG
1249
1250source "mm/Kconfig"
1251
1252config HIGHPTE
1253	bool "Allocate 3rd-level pagetables from highmem"
1254	depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1255	---help---
1256	  The VM uses one page table entry for each page of physical memory.
1257	  For systems with a lot of RAM, this can be wasteful of precious
1258	  low memory.  Setting this option will put user-space page table
1259	  entries in high memory.
1260
1261config X86_CHECK_BIOS_CORRUPTION
1262	bool "Check for low memory corruption"
1263	---help---
1264	  Periodically check for memory corruption in low memory, which
1265	  is suspected to be caused by BIOS.  Even when enabled in the
1266	  configuration, it is disabled at runtime.  Enable it by
1267	  setting "memory_corruption_check=1" on the kernel command
1268	  line.  By default it scans the low 64k of memory every 60
1269	  seconds; see the memory_corruption_check_size and
1270	  memory_corruption_check_period parameters in
1271	  Documentation/kernel-parameters.txt to adjust this.
1272
1273	  When enabled with the default parameters, this option has
1274	  almost no overhead, as it reserves a relatively small amount
1275	  of memory and scans it infrequently.  It both detects corruption
1276	  and prevents it from affecting the running system.
1277
1278	  It is, however, intended as a diagnostic tool; if repeatable
1279	  BIOS-originated corruption always affects the same memory,
1280	  you can use memmap= to prevent the kernel from using that
1281	  memory.
1282
1283config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1284	bool "Set the default setting of memory_corruption_check"
1285	depends on X86_CHECK_BIOS_CORRUPTION
1286	default y
1287	---help---
1288	  Set whether the default state of memory_corruption_check is
1289	  on or off.
1290
1291config X86_RESERVE_LOW_64K
1292	bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1293	default y
1294	---help---
1295	  Reserve the first 64K of physical RAM on BIOSes that are known
1296	  to potentially corrupt that memory range. A numbers of BIOSes are
1297	  known to utilize this area during suspend/resume, so it must not
1298	  be used by the kernel.
1299
1300	  Set this to N if you are absolutely sure that you trust the BIOS
1301	  to get all its memory reservations and usages right.
1302
1303	  If you have doubts about the BIOS (e.g. suspend/resume does not
1304	  work or there's kernel crashes after certain hardware hotplug
1305	  events) and it's not AMI or Phoenix, then you might want to enable
1306	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1307	  corruption patterns.
1308
1309	  Say Y if unsure.
1310
1311config MATH_EMULATION
1312	bool
1313	prompt "Math emulation" if X86_32
1314	---help---
1315	  Linux can emulate a math coprocessor (used for floating point
1316	  operations) if you don't have one. 486DX and Pentium processors have
1317	  a math coprocessor built in, 486SX and 386 do not, unless you added
1318	  a 487DX or 387, respectively. (The messages during boot time can
1319	  give you some hints here ["man dmesg"].) Everyone needs either a
1320	  coprocessor or this emulation.
1321
1322	  If you don't have a math coprocessor, you need to say Y here; if you
1323	  say Y here even though you have a coprocessor, the coprocessor will
1324	  be used nevertheless. (This behavior can be changed with the kernel
1325	  command line option "no387", which comes handy if your coprocessor
1326	  is broken. Try "man bootparam" or see the documentation of your boot
1327	  loader (lilo or loadlin) about how to pass options to the kernel at
1328	  boot time.) This means that it is a good idea to say Y here if you
1329	  intend to use this kernel on different machines.
1330
1331	  More information about the internals of the Linux math coprocessor
1332	  emulation can be found in <file:arch/x86/math-emu/README>.
1333
1334	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1335	  kernel, it won't hurt.
1336
1337config MTRR
1338	bool "MTRR (Memory Type Range Register) support"
1339	---help---
1340	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1341	  the Memory Type Range Registers (MTRRs) may be used to control
1342	  processor access to memory ranges. This is most useful if you have
1343	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1344	  allows bus write transfers to be combined into a larger transfer
1345	  before bursting over the PCI/AGP bus. This can increase performance
1346	  of image write operations 2.5 times or more. Saying Y here creates a
1347	  /proc/mtrr file which may be used to manipulate your processor's
1348	  MTRRs. Typically the X server should use this.
1349
1350	  This code has a reasonably generic interface so that similar
1351	  control registers on other processors can be easily supported
1352	  as well:
1353
1354	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1355	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1356	  these, the ARRs are used to emulate the MTRRs.
1357	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1358	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1359	  write-combining. All of these processors are supported by this code
1360	  and it makes sense to say Y here if you have one of them.
1361
1362	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1363	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1364	  can lead to all sorts of problems, so it's good to say Y here.
1365
1366	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1367	  just add about 9 KB to your kernel.
1368
1369	  See <file:Documentation/x86/mtrr.txt> for more information.
1370
1371config MTRR_SANITIZER
1372	def_bool y
1373	prompt "MTRR cleanup support"
1374	depends on MTRR
1375	---help---
1376	  Convert MTRR layout from continuous to discrete, so X drivers can
1377	  add writeback entries.
1378
1379	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1380	  The largest mtrr entry size for a continuous block can be set with
1381	  mtrr_chunk_size.
1382
1383	  If unsure, say Y.
1384
1385config MTRR_SANITIZER_ENABLE_DEFAULT
1386	int "MTRR cleanup enable value (0-1)"
1387	range 0 1
1388	default "0"
1389	depends on MTRR_SANITIZER
1390	---help---
1391	  Enable mtrr cleanup default value
1392
1393config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1394	int "MTRR cleanup spare reg num (0-7)"
1395	range 0 7
1396	default "1"
1397	depends on MTRR_SANITIZER
1398	---help---
1399	  mtrr cleanup spare entries default, it can be changed via
1400	  mtrr_spare_reg_nr=N on the kernel command line.
1401
1402config X86_PAT
1403	bool
1404	prompt "x86 PAT support"
1405	depends on MTRR
1406	---help---
1407	  Use PAT attributes to setup page level cache control.
1408
1409	  PATs are the modern equivalents of MTRRs and are much more
1410	  flexible than MTRRs.
1411
1412	  Say N here if you see bootup problems (boot crash, boot hang,
1413	  spontaneous reboots) or a non-working video driver.
1414
1415	  If unsure, say Y.
1416
1417config EFI
1418	bool "EFI runtime service support"
1419	depends on ACPI
1420	---help---
1421	  This enables the kernel to use EFI runtime services that are
1422	  available (such as the EFI variable services).
1423
1424	  This option is only useful on systems that have EFI firmware.
1425	  In addition, you should use the latest ELILO loader available
1426	  at <http://elilo.sourceforge.net> in order to take advantage
1427	  of EFI runtime services. However, even with this option, the
1428	  resultant kernel should continue to boot on existing non-EFI
1429	  platforms.
1430
1431config SECCOMP
1432	def_bool y
1433	prompt "Enable seccomp to safely compute untrusted bytecode"
1434	---help---
1435	  This kernel feature is useful for number crunching applications
1436	  that may need to compute untrusted bytecode during their
1437	  execution. By using pipes or other transports made available to
1438	  the process as file descriptors supporting the read/write
1439	  syscalls, it's possible to isolate those applications in
1440	  their own address space using seccomp. Once seccomp is
1441	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1442	  and the task is only allowed to execute a few safe syscalls
1443	  defined by each seccomp mode.
1444
1445	  If unsure, say Y. Only embedded should say N here.
1446
1447config CC_STACKPROTECTOR_ALL
1448	bool
1449
1450config CC_STACKPROTECTOR
1451	bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1452	select CC_STACKPROTECTOR_ALL
1453	---help---
1454	  This option turns on the -fstack-protector GCC feature. This
1455	  feature puts, at the beginning of functions, a canary value on
1456	  the stack just before the return address, and validates
1457	  the value just before actually returning.  Stack based buffer
1458	  overflows (that need to overwrite this return address) now also
1459	  overwrite the canary, which gets detected and the attack is then
1460	  neutralized via a kernel panic.
1461
1462	  This feature requires gcc version 4.2 or above, or a distribution
1463	  gcc with the feature backported. Older versions are automatically
1464	  detected and for those versions, this configuration option is
1465	  ignored. (and a warning is printed during bootup)
1466
1467source kernel/Kconfig.hz
1468
1469config KEXEC
1470	bool "kexec system call"
1471	---help---
1472	  kexec is a system call that implements the ability to shutdown your
1473	  current kernel, and to start another kernel.  It is like a reboot
1474	  but it is independent of the system firmware.   And like a reboot
1475	  you can start any kernel with it, not just Linux.
1476
1477	  The name comes from the similarity to the exec system call.
1478
1479	  It is an ongoing process to be certain the hardware in a machine
1480	  is properly shutdown, so do not be surprised if this code does not
1481	  initially work for you.  It may help to enable device hotplugging
1482	  support.  As of this writing the exact hardware interface is
1483	  strongly in flux, so no good recommendation can be made.
1484
1485config CRASH_DUMP
1486	bool "kernel crash dumps"
1487	depends on X86_64 || (X86_32 && HIGHMEM)
1488	---help---
1489	  Generate crash dump after being started by kexec.
1490	  This should be normally only set in special crash dump kernels
1491	  which are loaded in the main kernel with kexec-tools into
1492	  a specially reserved region and then later executed after
1493	  a crash by kdump/kexec. The crash dump kernel must be compiled
1494	  to a memory address not used by the main kernel or BIOS using
1495	  PHYSICAL_START, or it must be built as a relocatable image
1496	  (CONFIG_RELOCATABLE=y).
1497	  For more details see Documentation/kdump/kdump.txt
1498
1499config KEXEC_JUMP
1500	bool "kexec jump (EXPERIMENTAL)"
1501	depends on EXPERIMENTAL
1502	depends on KEXEC && HIBERNATION
1503	---help---
1504	  Jump between original kernel and kexeced kernel and invoke
1505	  code in physical address mode via KEXEC
1506
1507config PHYSICAL_START
1508	hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1509	default "0x1000000"
1510	---help---
1511	  This gives the physical address where the kernel is loaded.
1512
1513	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1514	  bzImage will decompress itself to above physical address and
1515	  run from there. Otherwise, bzImage will run from the address where
1516	  it has been loaded by the boot loader and will ignore above physical
1517	  address.
1518
1519	  In normal kdump cases one does not have to set/change this option
1520	  as now bzImage can be compiled as a completely relocatable image
1521	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1522	  address. This option is mainly useful for the folks who don't want
1523	  to use a bzImage for capturing the crash dump and want to use a
1524	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
1525	  to be specifically compiled to run from a specific memory area
1526	  (normally a reserved region) and this option comes handy.
1527
1528	  So if you are using bzImage for capturing the crash dump,
1529	  leave the value here unchanged to 0x1000000 and set
1530	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1531	  for capturing the crash dump change this value to start of
1532	  the reserved region.  In other words, it can be set based on
1533	  the "X" value as specified in the "crashkernel=YM@XM"
1534	  command line boot parameter passed to the panic-ed
1535	  kernel. Please take a look at Documentation/kdump/kdump.txt
1536	  for more details about crash dumps.
1537
1538	  Usage of bzImage for capturing the crash dump is recommended as
1539	  one does not have to build two kernels. Same kernel can be used
1540	  as production kernel and capture kernel. Above option should have
1541	  gone away after relocatable bzImage support is introduced. But it
1542	  is present because there are users out there who continue to use
1543	  vmlinux for dump capture. This option should go away down the
1544	  line.
1545
1546	  Don't change this unless you know what you are doing.
1547
1548config RELOCATABLE
1549	bool "Build a relocatable kernel"
1550	default y
1551	---help---
1552	  This builds a kernel image that retains relocation information
1553	  so it can be loaded someplace besides the default 1MB.
1554	  The relocations tend to make the kernel binary about 10% larger,
1555	  but are discarded at runtime.
1556
1557	  One use is for the kexec on panic case where the recovery kernel
1558	  must live at a different physical address than the primary
1559	  kernel.
1560
1561	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1562	  it has been loaded at and the compile time physical address
1563	  (CONFIG_PHYSICAL_START) is ignored.
1564
1565# Relocation on x86-32 needs some additional build support
1566config X86_NEED_RELOCS
1567	def_bool y
1568	depends on X86_32 && RELOCATABLE
1569
1570config PHYSICAL_ALIGN
1571	hex
1572	prompt "Alignment value to which kernel should be aligned" if X86_32
1573	default "0x1000000"
1574	range 0x2000 0x1000000
1575	---help---
1576	  This value puts the alignment restrictions on physical address
1577	  where kernel is loaded and run from. Kernel is compiled for an
1578	  address which meets above alignment restriction.
1579
1580	  If bootloader loads the kernel at a non-aligned address and
1581	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1582	  address aligned to above value and run from there.
1583
1584	  If bootloader loads the kernel at a non-aligned address and
1585	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1586	  load address and decompress itself to the address it has been
1587	  compiled for and run from there. The address for which kernel is
1588	  compiled already meets above alignment restrictions. Hence the
1589	  end result is that kernel runs from a physical address meeting
1590	  above alignment restrictions.
1591
1592	  Don't change this unless you know what you are doing.
1593
1594config HOTPLUG_CPU
1595	bool "Support for hot-pluggable CPUs"
1596	depends on SMP && HOTPLUG
1597	---help---
1598	  Say Y here to allow turning CPUs off and on. CPUs can be
1599	  controlled through /sys/devices/system/cpu.
1600	  ( Note: power management support will enable this option
1601	    automatically on SMP systems. )
1602	  Say N if you want to disable CPU hotplug.
1603
1604config COMPAT_VDSO
1605	def_bool y
1606	prompt "Compat VDSO support"
1607	depends on X86_32 || IA32_EMULATION
1608	---help---
1609	  Map the 32-bit VDSO to the predictable old-style address too.
1610	---help---
1611	  Say N here if you are running a sufficiently recent glibc
1612	  version (2.3.3 or later), to remove the high-mapped
1613	  VDSO mapping and to exclusively use the randomized VDSO.
1614
1615	  If unsure, say Y.
1616
1617config CMDLINE_BOOL
1618	bool "Built-in kernel command line"
1619	default n
1620	---help---
1621	  Allow for specifying boot arguments to the kernel at
1622	  build time.  On some systems (e.g. embedded ones), it is
1623	  necessary or convenient to provide some or all of the
1624	  kernel boot arguments with the kernel itself (that is,
1625	  to not rely on the boot loader to provide them.)
1626
1627	  To compile command line arguments into the kernel,
1628	  set this option to 'Y', then fill in the
1629	  the boot arguments in CONFIG_CMDLINE.
1630
1631	  Systems with fully functional boot loaders (i.e. non-embedded)
1632	  should leave this option set to 'N'.
1633
1634config CMDLINE
1635	string "Built-in kernel command string"
1636	depends on CMDLINE_BOOL
1637	default ""
1638	---help---
1639	  Enter arguments here that should be compiled into the kernel
1640	  image and used at boot time.  If the boot loader provides a
1641	  command line at boot time, it is appended to this string to
1642	  form the full kernel command line, when the system boots.
1643
1644	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1645	  change this behavior.
1646
1647	  In most cases, the command line (whether built-in or provided
1648	  by the boot loader) should specify the device for the root
1649	  file system.
1650
1651config CMDLINE_OVERRIDE
1652	bool "Built-in command line overrides boot loader arguments"
1653	default n
1654	depends on CMDLINE_BOOL
1655	---help---
1656	  Set this option to 'Y' to have the kernel ignore the boot loader
1657	  command line, and use ONLY the built-in command line.
1658
1659	  This is used to work around broken boot loaders.  This should
1660	  be set to 'N' under normal conditions.
1661
1662endmenu
1663
1664config ARCH_ENABLE_MEMORY_HOTPLUG
1665	def_bool y
1666	depends on X86_64 || (X86_32 && HIGHMEM)
1667
1668config ARCH_ENABLE_MEMORY_HOTREMOVE
1669	def_bool y
1670	depends on MEMORY_HOTPLUG
1671
1672config HAVE_ARCH_EARLY_PFN_TO_NID
1673	def_bool X86_64
1674	depends on NUMA
1675
1676menu "Power management and ACPI options"
1677
1678config ARCH_HIBERNATION_HEADER
1679	def_bool y
1680	depends on X86_64 && HIBERNATION
1681
1682source "kernel/power/Kconfig"
1683
1684source "drivers/acpi/Kconfig"
1685
1686config X86_APM_BOOT
1687	bool
1688	default y
1689	depends on APM || APM_MODULE
1690
1691menuconfig APM
1692	tristate "APM (Advanced Power Management) BIOS support"
1693	depends on X86_32 && PM_SLEEP
1694	---help---
1695	  APM is a BIOS specification for saving power using several different
1696	  techniques. This is mostly useful for battery powered laptops with
1697	  APM compliant BIOSes. If you say Y here, the system time will be
1698	  reset after a RESUME operation, the /proc/apm device will provide
1699	  battery status information, and user-space programs will receive
1700	  notification of APM "events" (e.g. battery status change).
1701
1702	  If you select "Y" here, you can disable actual use of the APM
1703	  BIOS by passing the "apm=off" option to the kernel at boot time.
1704
1705	  Note that the APM support is almost completely disabled for
1706	  machines with more than one CPU.
1707
1708	  In order to use APM, you will need supporting software. For location
1709	  and more information, read <file:Documentation/power/pm.txt> and the
1710	  Battery Powered Linux mini-HOWTO, available from
1711	  <http://www.tldp.org/docs.html#howto>.
1712
1713	  This driver does not spin down disk drives (see the hdparm(8)
1714	  manpage ("man 8 hdparm") for that), and it doesn't turn off
1715	  VESA-compliant "green" monitors.
1716
1717	  This driver does not support the TI 4000M TravelMate and the ACER
1718	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
1719	  desktop machines also don't have compliant BIOSes, and this driver
1720	  may cause those machines to panic during the boot phase.
1721
1722	  Generally, if you don't have a battery in your machine, there isn't
1723	  much point in using this driver and you should say N. If you get
1724	  random kernel OOPSes or reboots that don't seem to be related to
1725	  anything, try disabling/enabling this option (or disabling/enabling
1726	  APM in your BIOS).
1727
1728	  Some other things you should try when experiencing seemingly random,
1729	  "weird" problems:
1730
1731	  1) make sure that you have enough swap space and that it is
1732	  enabled.
1733	  2) pass the "no-hlt" option to the kernel
1734	  3) switch on floating point emulation in the kernel and pass
1735	  the "no387" option to the kernel
1736	  4) pass the "floppy=nodma" option to the kernel
1737	  5) pass the "mem=4M" option to the kernel (thereby disabling
1738	  all but the first 4 MB of RAM)
1739	  6) make sure that the CPU is not over clocked.
1740	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1741	  8) disable the cache from your BIOS settings
1742	  9) install a fan for the video card or exchange video RAM
1743	  10) install a better fan for the CPU
1744	  11) exchange RAM chips
1745	  12) exchange the motherboard.
1746
1747	  To compile this driver as a module, choose M here: the
1748	  module will be called apm.
1749
1750if APM
1751
1752config APM_IGNORE_USER_SUSPEND
1753	bool "Ignore USER SUSPEND"
1754	---help---
1755	  This option will ignore USER SUSPEND requests. On machines with a
1756	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
1757	  series notebooks, it is necessary to say Y because of a BIOS bug.
1758
1759config APM_DO_ENABLE
1760	bool "Enable PM at boot time"
1761	---help---
1762	  Enable APM features at boot time. From page 36 of the APM BIOS
1763	  specification: "When disabled, the APM BIOS does not automatically
1764	  power manage devices, enter the Standby State, enter the Suspend
1765	  State, or take power saving steps in response to CPU Idle calls."
1766	  This driver will make CPU Idle calls when Linux is idle (unless this
1767	  feature is turned off -- see "Do CPU IDLE calls", below). This
1768	  should always save battery power, but more complicated APM features
1769	  will be dependent on your BIOS implementation. You may need to turn
1770	  this option off if your computer hangs at boot time when using APM
1771	  support, or if it beeps continuously instead of suspending. Turn
1772	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1773	  T400CDT. This is off by default since most machines do fine without
1774	  this feature.
1775
1776config APM_CPU_IDLE
1777	bool "Make CPU Idle calls when idle"
1778	---help---
1779	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1780	  On some machines, this can activate improved power savings, such as
1781	  a slowed CPU clock rate, when the machine is idle. These idle calls
1782	  are made after the idle loop has run for some length of time (e.g.,
1783	  333 mS). On some machines, this will cause a hang at boot time or
1784	  whenever the CPU becomes idle. (On machines with more than one CPU,
1785	  this option does nothing.)
1786
1787config APM_DISPLAY_BLANK
1788	bool "Enable console blanking using APM"
1789	---help---
1790	  Enable console blanking using the APM. Some laptops can use this to
1791	  turn off the LCD backlight when the screen blanker of the Linux
1792	  virtual console blanks the screen. Note that this is only used by
1793	  the virtual console screen blanker, and won't turn off the backlight
1794	  when using the X Window system. This also doesn't have anything to
1795	  do with your VESA-compliant power-saving monitor. Further, this
1796	  option doesn't work for all laptops -- it might not turn off your
1797	  backlight at all, or it might print a lot of errors to the console,
1798	  especially if you are using gpm.
1799
1800config APM_ALLOW_INTS
1801	bool "Allow interrupts during APM BIOS calls"
1802	---help---
1803	  Normally we disable external interrupts while we are making calls to
1804	  the APM BIOS as a measure to lessen the effects of a badly behaving
1805	  BIOS implementation.  The BIOS should reenable interrupts if it
1806	  needs to.  Unfortunately, some BIOSes do not -- especially those in
1807	  many of the newer IBM Thinkpads.  If you experience hangs when you
1808	  suspend, try setting this to Y.  Otherwise, say N.
1809
1810endif # APM
1811
1812source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1813
1814source "drivers/cpuidle/Kconfig"
1815
1816source "drivers/idle/Kconfig"
1817
1818endmenu
1819
1820
1821menu "Bus options (PCI etc.)"
1822
1823config PCI
1824	bool "PCI support"
1825	default y
1826	select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1827	---help---
1828	  Find out whether you have a PCI motherboard. PCI is the name of a
1829	  bus system, i.e. the way the CPU talks to the other stuff inside
1830	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1831	  VESA. If you have PCI, say Y, otherwise N.
1832
1833choice
1834	prompt "PCI access mode"
1835	depends on X86_32 && PCI
1836	default PCI_GOANY
1837	---help---
1838	  On PCI systems, the BIOS can be used to detect the PCI devices and
1839	  determine their configuration. However, some old PCI motherboards
1840	  have BIOS bugs and may crash if this is done. Also, some embedded
1841	  PCI-based systems don't have any BIOS at all. Linux can also try to
1842	  detect the PCI hardware directly without using the BIOS.
1843
1844	  With this option, you can specify how Linux should detect the
1845	  PCI devices. If you choose "BIOS", the BIOS will be used,
1846	  if you choose "Direct", the BIOS won't be used, and if you
1847	  choose "MMConfig", then PCI Express MMCONFIG will be used.
1848	  If you choose "Any", the kernel will try MMCONFIG, then the
1849	  direct access method and falls back to the BIOS if that doesn't
1850	  work. If unsure, go with the default, which is "Any".
1851
1852config PCI_GOBIOS
1853	bool "BIOS"
1854
1855config PCI_GOMMCONFIG
1856	bool "MMConfig"
1857
1858config PCI_GODIRECT
1859	bool "Direct"
1860
1861config PCI_GOOLPC
1862	bool "OLPC"
1863	depends on OLPC
1864
1865config PCI_GOANY
1866	bool "Any"
1867
1868endchoice
1869
1870config PCI_BIOS
1871	def_bool y
1872	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1873
1874# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1875config PCI_DIRECT
1876	def_bool y
1877	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1878
1879config PCI_MMCONFIG
1880	def_bool y
1881	depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1882
1883config PCI_OLPC
1884	def_bool y
1885	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1886
1887config PCI_DOMAINS
1888	def_bool y
1889	depends on PCI
1890
1891config PCI_MMCONFIG
1892	bool "Support mmconfig PCI config space access"
1893	depends on X86_64 && PCI && ACPI
1894
1895config DMAR
1896	bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1897	depends on PCI_MSI && ACPI && EXPERIMENTAL
1898	help
1899	  DMA remapping (DMAR) devices support enables independent address
1900	  translations for Direct Memory Access (DMA) from devices.
1901	  These DMA remapping devices are reported via ACPI tables
1902	  and include PCI device scope covered by these DMA
1903	  remapping devices.
1904
1905config DMAR_DEFAULT_ON
1906	def_bool y
1907	prompt "Enable DMA Remapping Devices by default"
1908	depends on DMAR
1909	help
1910	  Selecting this option will enable a DMAR device at boot time if
1911	  one is found. If this option is not selected, DMAR support can
1912	  be enabled by passing intel_iommu=on to the kernel. It is
1913	  recommended you say N here while the DMAR code remains
1914	  experimental.
1915
1916config DMAR_BROKEN_GFX_WA
1917	def_bool n
1918	prompt "Workaround broken graphics drivers (going away soon)"
1919	depends on DMAR
1920	---help---
1921	  Current Graphics drivers tend to use physical address
1922	  for DMA and avoid using DMA APIs. Setting this config
1923	  option permits the IOMMU driver to set a unity map for
1924	  all the OS-visible memory. Hence the driver can continue
1925	  to use physical addresses for DMA, at least until this
1926	  option is removed in the 2.6.32 kernel.
1927
1928config DMAR_FLOPPY_WA
1929	def_bool y
1930	depends on DMAR
1931	---help---
1932	  Floppy disk drivers are known to bypass DMA API calls
1933	  thereby failing to work when IOMMU is enabled. This
1934	  workaround will setup a 1:1 mapping for the first
1935	  16MiB to make floppy (an ISA device) work.
1936
1937config INTR_REMAP
1938	bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1939	depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1940	---help---
1941	  Supports Interrupt remapping for IO-APIC and MSI devices.
1942	  To use x2apic mode in the CPU's which support x2APIC enhancements or
1943	  to support platforms with CPU's having > 8 bit APIC ID, say Y.
1944
1945source "drivers/pci/pcie/Kconfig"
1946
1947source "drivers/pci/Kconfig"
1948
1949# x86_64 have no ISA slots, but do have ISA-style DMA.
1950config ISA_DMA_API
1951	def_bool y
1952
1953if X86_32
1954
1955config ISA
1956	bool "ISA support"
1957	---help---
1958	  Find out whether you have ISA slots on your motherboard.  ISA is the
1959	  name of a bus system, i.e. the way the CPU talks to the other stuff
1960	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
1961	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1962	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
1963
1964config EISA
1965	bool "EISA support"
1966	depends on ISA
1967	---help---
1968	  The Extended Industry Standard Architecture (EISA) bus was
1969	  developed as an open alternative to the IBM MicroChannel bus.
1970
1971	  The EISA bus provided some of the features of the IBM MicroChannel
1972	  bus while maintaining backward compatibility with cards made for
1973	  the older ISA bus.  The EISA bus saw limited use between 1988 and
1974	  1995 when it was made obsolete by the PCI bus.
1975
1976	  Say Y here if you are building a kernel for an EISA-based machine.
1977
1978	  Otherwise, say N.
1979
1980source "drivers/eisa/Kconfig"
1981
1982config MCA
1983	bool "MCA support"
1984	---help---
1985	  MicroChannel Architecture is found in some IBM PS/2 machines and
1986	  laptops.  It is a bus system similar to PCI or ISA. See
1987	  <file:Documentation/mca.txt> (and especially the web page given
1988	  there) before attempting to build an MCA bus kernel.
1989
1990source "drivers/mca/Kconfig"
1991
1992config SCx200
1993	tristate "NatSemi SCx200 support"
1994	---help---
1995	  This provides basic support for National Semiconductor's
1996	  (now AMD's) Geode processors.  The driver probes for the
1997	  PCI-IDs of several on-chip devices, so its a good dependency
1998	  for other scx200_* drivers.
1999
2000	  If compiled as a module, the driver is named scx200.
2001
2002config SCx200HR_TIMER
2003	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2004	depends on SCx200 && GENERIC_TIME
2005	default y
2006	---help---
2007	  This driver provides a clocksource built upon the on-chip
2008	  27MHz high-resolution timer.  Its also a workaround for
2009	  NSC Geode SC-1100's buggy TSC, which loses time when the
2010	  processor goes idle (as is done by the scheduler).  The
2011	  other workaround is idle=poll boot option.
2012
2013config GEODE_MFGPT_TIMER
2014	def_bool y
2015	prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2016	depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2017	---help---
2018	  This driver provides a clock event source based on the MFGPT
2019	  timer(s) in the CS5535 and CS5536 companion chip for the geode.
2020	  MFGPTs have a better resolution and max interval than the
2021	  generic PIT, and are suitable for use as high-res timers.
2022
2023config OLPC
2024	bool "One Laptop Per Child support"
2025	default n
2026	---help---
2027	  Add support for detecting the unique features of the OLPC
2028	  XO hardware.
2029
2030endif # X86_32
2031
2032config K8_NB
2033	def_bool y
2034	depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2035
2036source "drivers/pcmcia/Kconfig"
2037
2038source "drivers/pci/hotplug/Kconfig"
2039
2040endmenu
2041
2042
2043menu "Executable file formats / Emulations"
2044
2045source "fs/Kconfig.binfmt"
2046
2047config IA32_EMULATION
2048	bool "IA32 Emulation"
2049	depends on X86_64
2050	select COMPAT_BINFMT_ELF
2051	---help---
2052	  Include code to run 32-bit programs under a 64-bit kernel. You should
2053	  likely turn this on, unless you're 100% sure that you don't have any
2054	  32-bit programs left.
2055
2056config IA32_AOUT
2057	tristate "IA32 a.out support"
2058	depends on IA32_EMULATION
2059	---help---
2060	  Support old a.out binaries in the 32bit emulation.
2061
2062config COMPAT
2063	def_bool y
2064	depends on IA32_EMULATION
2065
2066config COMPAT_FOR_U64_ALIGNMENT
2067	def_bool COMPAT
2068	depends on X86_64
2069
2070config SYSVIPC_COMPAT
2071	def_bool y
2072	depends on COMPAT && SYSVIPC
2073
2074endmenu
2075
2076
2077config HAVE_ATOMIC_IOMAP
2078	def_bool y
2079	depends on X86_32
2080
2081source "net/Kconfig"
2082
2083source "drivers/Kconfig"
2084
2085source "drivers/firmware/Kconfig"
2086
2087source "fs/Kconfig"
2088
2089source "arch/x86/Kconfig.debug"
2090
2091source "security/Kconfig"
2092
2093source "crypto/Kconfig"
2094
2095source "arch/x86/kvm/Kconfig"
2096
2097source "lib/Kconfig"
2098