Root/arch/x86/Kconfig

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_PERF_EVENTS if (!M386 && !M486)
28    select HAVE_IOREMAP_PROT
29    select HAVE_KPROBES
30    select ARCH_WANT_OPTIONAL_GPIOLIB
31    select ARCH_WANT_FRAME_POINTERS
32    select HAVE_DMA_ATTRS
33    select HAVE_KRETPROBES
34    select HAVE_OPTPROBES
35    select HAVE_FTRACE_MCOUNT_RECORD
36    select HAVE_DYNAMIC_FTRACE
37    select HAVE_FUNCTION_TRACER
38    select HAVE_FUNCTION_GRAPH_TRACER
39    select HAVE_FUNCTION_GRAPH_FP_TEST
40    select HAVE_FUNCTION_TRACE_MCOUNT_TEST
41    select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
42    select HAVE_SYSCALL_TRACEPOINTS
43    select HAVE_KVM
44    select HAVE_ARCH_KGDB
45    select HAVE_ARCH_TRACEHOOK
46    select HAVE_GENERIC_DMA_COHERENT if X86_32
47    select HAVE_EFFICIENT_UNALIGNED_ACCESS
48    select USER_STACKTRACE_SUPPORT
49    select HAVE_REGS_AND_STACK_ACCESS_API
50    select HAVE_DMA_API_DEBUG
51    select HAVE_KERNEL_GZIP
52    select HAVE_KERNEL_BZIP2
53    select HAVE_KERNEL_LZMA
54    select HAVE_KERNEL_LZO
55    select HAVE_HW_BREAKPOINT
56    select HAVE_MIXED_BREAKPOINTS_REGS
57    select PERF_EVENTS
58    select HAVE_PERF_EVENTS_NMI
59    select ANON_INODES
60    select HAVE_ARCH_KMEMCHECK
61    select HAVE_USER_RETURN_NOTIFIER
62
63config INSTRUCTION_DECODER
64    def_bool (KPROBES || PERF_EVENTS)
65
66config OUTPUT_FORMAT
67    string
68    default "elf32-i386" if X86_32
69    default "elf64-x86-64" if X86_64
70
71config ARCH_DEFCONFIG
72    string
73    default "arch/x86/configs/i386_defconfig" if X86_32
74    default "arch/x86/configs/x86_64_defconfig" if X86_64
75
76config GENERIC_CMOS_UPDATE
77    def_bool y
78
79config CLOCKSOURCE_WATCHDOG
80    def_bool y
81
82config GENERIC_CLOCKEVENTS
83    def_bool y
84
85config GENERIC_CLOCKEVENTS_BROADCAST
86    def_bool y
87    depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
88
89config LOCKDEP_SUPPORT
90    def_bool y
91
92config STACKTRACE_SUPPORT
93    def_bool y
94
95config HAVE_LATENCYTOP_SUPPORT
96    def_bool y
97
98config MMU
99    def_bool y
100
101config ZONE_DMA
102    def_bool y
103
104config SBUS
105    bool
106
107config NEED_DMA_MAP_STATE
108       def_bool (X86_64 || DMAR || DMA_API_DEBUG)
109
110config NEED_SG_DMA_LENGTH
111    def_bool y
112
113config GENERIC_ISA_DMA
114    def_bool y
115
116config GENERIC_IOMAP
117    def_bool y
118
119config GENERIC_BUG
120    def_bool y
121    depends on BUG
122    select GENERIC_BUG_RELATIVE_POINTERS if X86_64
123
124config GENERIC_BUG_RELATIVE_POINTERS
125    bool
126
127config GENERIC_HWEIGHT
128    def_bool y
129
130config GENERIC_GPIO
131    bool
132
133config ARCH_MAY_HAVE_PC_FDC
134    def_bool y
135
136config RWSEM_GENERIC_SPINLOCK
137    def_bool !X86_XADD
138
139config RWSEM_XCHGADD_ALGORITHM
140    def_bool X86_XADD
141
142config ARCH_HAS_CPU_IDLE_WAIT
143    def_bool y
144
145config GENERIC_CALIBRATE_DELAY
146    def_bool y
147
148config GENERIC_TIME_VSYSCALL
149    bool
150    default X86_64
151
152config ARCH_HAS_CPU_RELAX
153    def_bool y
154
155config ARCH_HAS_DEFAULT_IDLE
156    def_bool y
157
158config ARCH_HAS_CACHE_LINE_SIZE
159    def_bool y
160
161config HAVE_SETUP_PER_CPU_AREA
162    def_bool y
163
164config NEED_PER_CPU_EMBED_FIRST_CHUNK
165    def_bool y
166
167config NEED_PER_CPU_PAGE_FIRST_CHUNK
168    def_bool y
169
170config HAVE_CPUMASK_OF_CPU_MAP
171    def_bool X86_64_SMP
172
173config ARCH_HIBERNATION_POSSIBLE
174    def_bool y
175
176config ARCH_SUSPEND_POSSIBLE
177    def_bool y
178
179config ZONE_DMA32
180    bool
181    default X86_64
182
183config ARCH_POPULATES_NODE_MAP
184    def_bool y
185
186config AUDIT_ARCH
187    bool
188    default X86_64
189
190config ARCH_SUPPORTS_OPTIMIZED_INLINING
191    def_bool y
192
193config ARCH_SUPPORTS_DEBUG_PAGEALLOC
194    def_bool y
195
196config HAVE_EARLY_RES
197    def_bool y
198
199config HAVE_INTEL_TXT
200    def_bool y
201    depends on EXPERIMENTAL && DMAR && ACPI
202
203# Use the generic interrupt handling code in kernel/irq/:
204config GENERIC_HARDIRQS
205    def_bool y
206
207config GENERIC_HARDIRQS_NO__DO_IRQ
208       def_bool y
209
210config GENERIC_IRQ_PROBE
211    def_bool y
212
213config GENERIC_PENDING_IRQ
214    def_bool y
215    depends on GENERIC_HARDIRQS && SMP
216
217config USE_GENERIC_SMP_HELPERS
218    def_bool y
219    depends on SMP
220
221config X86_32_SMP
222    def_bool y
223    depends on X86_32 && SMP
224
225config X86_64_SMP
226    def_bool y
227    depends on X86_64 && SMP
228
229config X86_HT
230    def_bool y
231    depends on SMP
232
233config X86_TRAMPOLINE
234    def_bool y
235    depends on SMP || (64BIT && ACPI_SLEEP)
236
237config X86_32_LAZY_GS
238    def_bool y
239    depends on X86_32 && !CC_STACKPROTECTOR
240
241config ARCH_HWEIGHT_CFLAGS
242    string
243    default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
244    default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
245
246config KTIME_SCALAR
247    def_bool X86_32
248
249config ARCH_CPU_PROBE_RELEASE
250    def_bool y
251    depends on HOTPLUG_CPU
252
253source "init/Kconfig"
254source "kernel/Kconfig.freezer"
255
256menu "Processor type and features"
257
258source "kernel/time/Kconfig"
259
260config SMP
261    bool "Symmetric multi-processing support"
262    ---help---
263      This enables support for systems with more than one CPU. If you have
264      a system with only one CPU, like most personal computers, say N. If
265      you have a system with more than one CPU, say Y.
266
267      If you say N here, the kernel will run on single and multiprocessor
268      machines, but will use only one CPU of a multiprocessor machine. If
269      you say Y here, the kernel will run on many, but not all,
270      singleprocessor machines. On a singleprocessor machine, the kernel
271      will run faster if you say N here.
272
273      Note that if you say Y here and choose architecture "586" or
274      "Pentium" under "Processor family", the kernel will not work on 486
275      architectures. Similarly, multiprocessor kernels for the "PPro"
276      architecture may not work on all Pentium based boards.
277
278      People using multiprocessor machines who say Y here should also say
279      Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
280      Management" code will be disabled if you say Y here.
281
282      See also <file:Documentation/i386/IO-APIC.txt>,
283      <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
284      <http://www.tldp.org/docs.html#howto>.
285
286      If you don't know what to do here, say N.
287
288config X86_X2APIC
289    bool "Support x2apic"
290    depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
291    ---help---
292      This enables x2apic support on CPUs that have this feature.
293
294      This allows 32-bit apic IDs (so it can support very large systems),
295      and accesses the local apic via MSRs not via mmio.
296
297      If you don't know what to do here, say N.
298
299config SPARSE_IRQ
300    bool "Support sparse irq numbering"
301    depends on PCI_MSI || HT_IRQ
302    ---help---
303      This enables support for sparse irqs. This is useful for distro
304      kernels that want to define a high CONFIG_NR_CPUS value but still
305      want to have low kernel memory footprint on smaller machines.
306
307      ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
308        out the irq_desc[] array in a more NUMA-friendly way. )
309
310      If you don't know what to do here, say N.
311
312config NUMA_IRQ_DESC
313    def_bool y
314    depends on SPARSE_IRQ && NUMA
315
316config X86_MPPARSE
317    bool "Enable MPS table" if ACPI
318    default y
319    depends on X86_LOCAL_APIC
320    ---help---
321      For old smp systems that do not have proper acpi support. Newer systems
322      (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
323
324config X86_BIGSMP
325    bool "Support for big SMP systems with more than 8 CPUs"
326    depends on X86_32 && SMP
327    ---help---
328      This option is needed for the systems that have more than 8 CPUs
329
330if X86_32
331config X86_EXTENDED_PLATFORM
332    bool "Support for extended (non-PC) x86 platforms"
333    default y
334    ---help---
335      If you disable this option then the kernel will only support
336      standard PC platforms. (which covers the vast majority of
337      systems out there.)
338
339      If you enable this option then you'll be able to select support
340      for the following (non-PC) 32 bit x86 platforms:
341        AMD Elan
342        NUMAQ (IBM/Sequent)
343        RDC R-321x SoC
344        SGI 320/540 (Visual Workstation)
345        Summit/EXA (IBM x440)
346        Unisys ES7000 IA32 series
347        Moorestown MID devices
348
349      If you have one of these systems, or if you want to build a
350      generic distribution kernel, say Y here - otherwise say N.
351endif
352
353if X86_64
354config X86_EXTENDED_PLATFORM
355    bool "Support for extended (non-PC) x86 platforms"
356    default y
357    ---help---
358      If you disable this option then the kernel will only support
359      standard PC platforms. (which covers the vast majority of
360      systems out there.)
361
362      If you enable this option then you'll be able to select support
363      for the following (non-PC) 64 bit x86 platforms:
364        ScaleMP vSMP
365        SGI Ultraviolet
366
367      If you have one of these systems, or if you want to build a
368      generic distribution kernel, say Y here - otherwise say N.
369endif
370# This is an alphabetically sorted list of 64 bit extended platforms
371# Please maintain the alphabetic order if and when there are additions
372
373config X86_VSMP
374    bool "ScaleMP vSMP"
375    select PARAVIRT
376    depends on X86_64 && PCI
377    depends on X86_EXTENDED_PLATFORM
378    ---help---
379      Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
380      supposed to run on these EM64T-based machines. Only choose this option
381      if you have one of these machines.
382
383config X86_UV
384    bool "SGI Ultraviolet"
385    depends on X86_64
386    depends on X86_EXTENDED_PLATFORM
387    depends on NUMA
388    depends on X86_X2APIC
389    ---help---
390      This option is needed in order to support SGI Ultraviolet systems.
391      If you don't have one of these, you should say N here.
392
393# Following is an alphabetically sorted list of 32 bit extended platforms
394# Please maintain the alphabetic order if and when there are additions
395
396config X86_ELAN
397    bool "AMD Elan"
398    depends on X86_32
399    depends on X86_EXTENDED_PLATFORM
400    ---help---
401      Select this for an AMD Elan processor.
402
403      Do not use this option for K6/Athlon/Opteron processors!
404
405      If unsure, choose "PC-compatible" instead.
406
407config X86_MRST
408       bool "Moorestown MID platform"
409    depends on PCI
410    depends on PCI_GOANY
411    depends on X86_32
412    depends on X86_EXTENDED_PLATFORM
413    depends on X86_IO_APIC
414    select APB_TIMER
415    ---help---
416      Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
417      Internet Device(MID) platform. Moorestown consists of two chips:
418      Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
419      Unlike standard x86 PCs, Moorestown does not have many legacy devices
420      nor standard legacy replacement devices/features. e.g. Moorestown does
421      not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
422
423config X86_RDC321X
424    bool "RDC R-321x SoC"
425    depends on X86_32
426    depends on X86_EXTENDED_PLATFORM
427    select M486
428    select X86_REBOOTFIXUPS
429    ---help---
430      This option is needed for RDC R-321x system-on-chip, also known
431      as R-8610-(G).
432      If you don't have one of these chips, you should say N here.
433
434config X86_32_NON_STANDARD
435    bool "Support non-standard 32-bit SMP architectures"
436    depends on X86_32 && SMP
437    depends on X86_EXTENDED_PLATFORM
438    ---help---
439      This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
440      subarchitectures. It is intended for a generic binary kernel.
441      if you select them all, kernel will probe it one by one. and will
442      fallback to default.
443
444# Alphabetically sorted list of Non standard 32 bit platforms
445
446config X86_NUMAQ
447    bool "NUMAQ (IBM/Sequent)"
448    depends on X86_32_NON_STANDARD
449    depends on PCI
450    select NUMA
451    select X86_MPPARSE
452    ---help---
453      This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
454      NUMA multiquad box. This changes the way that processors are
455      bootstrapped, and uses Clustered Logical APIC addressing mode instead
456      of Flat Logical. You will need a new lynxer.elf file to flash your
457      firmware with - send email to <Martin.Bligh@us.ibm.com>.
458
459config X86_SUPPORTS_MEMORY_FAILURE
460    def_bool y
461    # MCE code calls memory_failure():
462    depends on X86_MCE
463    # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
464    depends on !X86_NUMAQ
465    # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
466    depends on X86_64 || !SPARSEMEM
467    select ARCH_SUPPORTS_MEMORY_FAILURE
468
469config X86_VISWS
470    bool "SGI 320/540 (Visual Workstation)"
471    depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
472    depends on X86_32_NON_STANDARD
473    ---help---
474      The SGI Visual Workstation series is an IA32-based workstation
475      based on SGI systems chips with some legacy PC hardware attached.
476
477      Say Y here to create a kernel to run on the SGI 320 or 540.
478
479      A kernel compiled for the Visual Workstation will run on general
480      PCs as well. See <file:Documentation/sgi-visws.txt> for details.
481
482config X86_SUMMIT
483    bool "Summit/EXA (IBM x440)"
484    depends on X86_32_NON_STANDARD
485    ---help---
486      This option is needed for IBM systems that use the Summit/EXA chipset.
487      In particular, it is needed for the x440.
488
489config X86_ES7000
490    bool "Unisys ES7000 IA32 series"
491    depends on X86_32_NON_STANDARD && X86_BIGSMP
492    ---help---
493      Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
494      supposed to run on an IA32-based Unisys ES7000 system.
495
496config SCHED_OMIT_FRAME_POINTER
497    def_bool y
498    prompt "Single-depth WCHAN output"
499    depends on X86
500    ---help---
501      Calculate simpler /proc/<PID>/wchan values. If this option
502      is disabled then wchan values will recurse back to the
503      caller function. This provides more accurate wchan values,
504      at the expense of slightly more scheduling overhead.
505
506      If in doubt, say "Y".
507
508menuconfig PARAVIRT_GUEST
509    bool "Paravirtualized guest support"
510    ---help---
511      Say Y here to get to see options related to running Linux under
512      various hypervisors. This option alone does not add any kernel code.
513
514      If you say N, all options in this submenu will be skipped and disabled.
515
516if PARAVIRT_GUEST
517
518source "arch/x86/xen/Kconfig"
519
520config VMI
521    bool "VMI Guest support (DEPRECATED)"
522    select PARAVIRT
523    depends on X86_32
524    ---help---
525      VMI provides a paravirtualized interface to the VMware ESX server
526      (it could be used by other hypervisors in theory too, but is not
527      at the moment), by linking the kernel to a GPL-ed ROM module
528      provided by the hypervisor.
529
530      As of September 2009, VMware has started a phased retirement
531      of this feature from VMware's products. Please see
532      feature-removal-schedule.txt for details. If you are
533      planning to enable this option, please note that you cannot
534      live migrate a VMI enabled VM to a future VMware product,
535      which doesn't support VMI. So if you expect your kernel to
536      seamlessly migrate to newer VMware products, keep this
537      disabled.
538
539config KVM_CLOCK
540    bool "KVM paravirtualized clock"
541    select PARAVIRT
542    select PARAVIRT_CLOCK
543    ---help---
544      Turning on this option will allow you to run a paravirtualized clock
545      when running over the KVM hypervisor. Instead of relying on a PIT
546      (or probably other) emulation by the underlying device model, the host
547      provides the guest with timing infrastructure such as time of day, and
548      system time
549
550config KVM_GUEST
551    bool "KVM Guest support"
552    select PARAVIRT
553    ---help---
554      This option enables various optimizations for running under the KVM
555      hypervisor.
556
557source "arch/x86/lguest/Kconfig"
558
559config PARAVIRT
560    bool "Enable paravirtualization code"
561    ---help---
562      This changes the kernel so it can modify itself when it is run
563      under a hypervisor, potentially improving performance significantly
564      over full virtualization. However, when run without a hypervisor
565      the kernel is theoretically slower and slightly larger.
566
567config PARAVIRT_SPINLOCKS
568    bool "Paravirtualization layer for spinlocks"
569    depends on PARAVIRT && SMP && EXPERIMENTAL
570    ---help---
571      Paravirtualized spinlocks allow a pvops backend to replace the
572      spinlock implementation with something virtualization-friendly
573      (for example, block the virtual CPU rather than spinning).
574
575      Unfortunately the downside is an up to 5% performance hit on
576      native kernels, with various workloads.
577
578      If you are unsure how to answer this question, answer N.
579
580config PARAVIRT_CLOCK
581    bool
582
583endif
584
585config PARAVIRT_DEBUG
586    bool "paravirt-ops debugging"
587    depends on PARAVIRT && DEBUG_KERNEL
588    ---help---
589      Enable to debug paravirt_ops internals. Specifically, BUG if
590      a paravirt_op is missing when it is called.
591
592config NO_BOOTMEM
593    default y
594    bool "Disable Bootmem code"
595    ---help---
596      Use early_res directly instead of bootmem before slab is ready.
597        - allocator (buddy) [generic]
598        - early allocator (bootmem) [generic]
599        - very early allocator (reserve_early*()) [x86]
600        - very very early allocator (early brk model) [x86]
601      So reduce one layer between early allocator to final allocator
602
603
604config MEMTEST
605    bool "Memtest"
606    ---help---
607      This option adds a kernel parameter 'memtest', which allows memtest
608      to be set.
609            memtest=0, mean disabled; -- default
610            memtest=1, mean do 1 test pattern;
611            ...
612            memtest=4, mean do 4 test patterns.
613      If you are unsure how to answer this question, answer N.
614
615config X86_SUMMIT_NUMA
616    def_bool y
617    depends on X86_32 && NUMA && X86_32_NON_STANDARD
618
619config X86_CYCLONE_TIMER
620    def_bool y
621    depends on X86_32_NON_STANDARD
622
623source "arch/x86/Kconfig.cpu"
624
625config HPET_TIMER
626    def_bool X86_64
627    prompt "HPET Timer Support" if X86_32
628    ---help---
629      Use the IA-PC HPET (High Precision Event Timer) to manage
630      time in preference to the PIT and RTC, if a HPET is
631      present.
632      HPET is the next generation timer replacing legacy 8254s.
633      The HPET provides a stable time base on SMP
634      systems, unlike the TSC, but it is more expensive to access,
635      as it is off-chip. You can find the HPET spec at
636      <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
637
638      You can safely choose Y here. However, HPET will only be
639      activated if the platform and the BIOS support this feature.
640      Otherwise the 8254 will be used for timing services.
641
642      Choose N to continue using the legacy 8254 timer.
643
644config HPET_EMULATE_RTC
645    def_bool y
646    depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
647
648config APB_TIMER
649       def_bool y if MRST
650       prompt "Langwell APB Timer Support" if X86_MRST
651       help
652         APB timer is the replacement for 8254, HPET on X86 MID platforms.
653         The APBT provides a stable time base on SMP
654         systems, unlike the TSC, but it is more expensive to access,
655         as it is off-chip. APB timers are always running regardless of CPU
656         C states, they are used as per CPU clockevent device when possible.
657
658# Mark as embedded because too many people got it wrong.
659# The code disables itself when not needed.
660config DMI
661    default y
662    bool "Enable DMI scanning" if EMBEDDED
663    ---help---
664      Enabled scanning of DMI to identify machine quirks. Say Y
665      here unless you have verified that your setup is not
666      affected by entries in the DMI blacklist. Required by PNP
667      BIOS code.
668
669config GART_IOMMU
670    bool "GART IOMMU support" if EMBEDDED
671    default y
672    select SWIOTLB
673    depends on X86_64 && PCI && K8_NB
674    ---help---
675      Support for full DMA access of devices with 32bit memory access only
676      on systems with more than 3GB. This is usually needed for USB,
677      sound, many IDE/SATA chipsets and some other devices.
678      Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
679      based hardware IOMMU and a software bounce buffer based IOMMU used
680      on Intel systems and as fallback.
681      The code is only active when needed (enough memory and limited
682      device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
683      too.
684
685config CALGARY_IOMMU
686    bool "IBM Calgary IOMMU support"
687    select SWIOTLB
688    depends on X86_64 && PCI && EXPERIMENTAL
689    ---help---
690      Support for hardware IOMMUs in IBM's xSeries x366 and x460
691      systems. Needed to run systems with more than 3GB of memory
692      properly with 32-bit PCI devices that do not support DAC
693      (Double Address Cycle). Calgary also supports bus level
694      isolation, where all DMAs pass through the IOMMU. This
695      prevents them from going anywhere except their intended
696      destination. This catches hard-to-find kernel bugs and
697      mis-behaving drivers and devices that do not use the DMA-API
698      properly to set up their DMA buffers. The IOMMU can be
699      turned off at boot time with the iommu=off parameter.
700      Normally the kernel will make the right choice by itself.
701      If unsure, say Y.
702
703config CALGARY_IOMMU_ENABLED_BY_DEFAULT
704    def_bool y
705    prompt "Should Calgary be enabled by default?"
706    depends on CALGARY_IOMMU
707    ---help---
708      Should Calgary be enabled by default? if you choose 'y', Calgary
709      will be used (if it exists). If you choose 'n', Calgary will not be
710      used even if it exists. If you choose 'n' and would like to use
711      Calgary anyway, pass 'iommu=calgary' on the kernel command line.
712      If unsure, say Y.
713
714config AMD_IOMMU
715    bool "AMD IOMMU support"
716    select SWIOTLB
717    select PCI_MSI
718    depends on X86_64 && PCI && ACPI
719    ---help---
720      With this option you can enable support for AMD IOMMU hardware in
721      your system. An IOMMU is a hardware component which provides
722      remapping of DMA memory accesses from devices. With an AMD IOMMU you
723      can isolate the the DMA memory of different devices and protect the
724      system from misbehaving device drivers or hardware.
725
726      You can find out if your system has an AMD IOMMU if you look into
727      your BIOS for an option to enable it or if you have an IVRS ACPI
728      table.
729
730config AMD_IOMMU_STATS
731    bool "Export AMD IOMMU statistics to debugfs"
732    depends on AMD_IOMMU
733    select DEBUG_FS
734    ---help---
735      This option enables code in the AMD IOMMU driver to collect various
736      statistics about whats happening in the driver and exports that
737      information to userspace via debugfs.
738      If unsure, say N.
739
740# need this always selected by IOMMU for the VIA workaround
741config SWIOTLB
742    def_bool y if X86_64
743    ---help---
744      Support for software bounce buffers used on x86-64 systems
745      which don't have a hardware IOMMU (e.g. the current generation
746      of Intel's x86-64 CPUs). Using this PCI devices which can only
747      access 32-bits of memory can be used on systems with more than
748      3 GB of memory. If unsure, say Y.
749
750config IOMMU_HELPER
751    def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
752
753config IOMMU_API
754    def_bool (AMD_IOMMU || DMAR)
755
756config MAXSMP
757    bool "Enable Maximum number of SMP Processors and NUMA Nodes"
758    depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
759    select CPUMASK_OFFSTACK
760    ---help---
761      Enable maximum number of CPUS and NUMA Nodes for this architecture.
762      If unsure, say N.
763
764config NR_CPUS
765    int "Maximum number of CPUs" if SMP && !MAXSMP
766    range 2 8 if SMP && X86_32 && !X86_BIGSMP
767    range 2 512 if SMP && !MAXSMP
768    default "1" if !SMP
769    default "4096" if MAXSMP
770    default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
771    default "8" if SMP
772    ---help---
773      This allows you to specify the maximum number of CPUs which this
774      kernel will support. The maximum supported value is 512 and the
775      minimum value which makes sense is 2.
776
777      This is purely to save memory - each supported CPU adds
778      approximately eight kilobytes to the kernel image.
779
780config SCHED_SMT
781    bool "SMT (Hyperthreading) scheduler support"
782    depends on X86_HT
783    ---help---
784      SMT scheduler support improves the CPU scheduler's decision making
785      when dealing with Intel Pentium 4 chips with HyperThreading at a
786      cost of slightly increased overhead in some places. If unsure say
787      N here.
788
789config SCHED_MC
790    def_bool y
791    prompt "Multi-core scheduler support"
792    depends on X86_HT
793    ---help---
794      Multi-core scheduler support improves the CPU scheduler's decision
795      making when dealing with multi-core CPU chips at a cost of slightly
796      increased overhead in some places. If unsure say N here.
797
798source "kernel/Kconfig.preempt"
799
800config X86_UP_APIC
801    bool "Local APIC support on uniprocessors"
802    depends on X86_32 && !SMP && !X86_32_NON_STANDARD
803    ---help---
804      A local APIC (Advanced Programmable Interrupt Controller) is an
805      integrated interrupt controller in the CPU. If you have a single-CPU
806      system which has a processor with a local APIC, you can say Y here to
807      enable and use it. If you say Y here even though your machine doesn't
808      have a local APIC, then the kernel will still run with no slowdown at
809      all. The local APIC supports CPU-generated self-interrupts (timer,
810      performance counters), and the NMI watchdog which detects hard
811      lockups.
812
813config X86_UP_IOAPIC
814    bool "IO-APIC support on uniprocessors"
815    depends on X86_UP_APIC
816    ---help---
817      An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
818      SMP-capable replacement for PC-style interrupt controllers. Most
819      SMP systems and many recent uniprocessor systems have one.
820
821      If you have a single-CPU system with an IO-APIC, you can say Y here
822      to use it. If you say Y here even though your machine doesn't have
823      an IO-APIC, then the kernel will still run with no slowdown at all.
824
825config X86_LOCAL_APIC
826    def_bool y
827    depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
828
829config X86_IO_APIC
830    def_bool y
831    depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
832
833config X86_VISWS_APIC
834    def_bool y
835    depends on X86_32 && X86_VISWS
836
837config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
838    bool "Reroute for broken boot IRQs"
839    depends on X86_IO_APIC
840    ---help---
841      This option enables a workaround that fixes a source of
842      spurious interrupts. This is recommended when threaded
843      interrupt handling is used on systems where the generation of
844      superfluous "boot interrupts" cannot be disabled.
845
846      Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
847      entry in the chipset's IO-APIC is masked (as, e.g. the RT
848      kernel does during interrupt handling). On chipsets where this
849      boot IRQ generation cannot be disabled, this workaround keeps
850      the original IRQ line masked so that only the equivalent "boot
851      IRQ" is delivered to the CPUs. The workaround also tells the
852      kernel to set up the IRQ handler on the boot IRQ line. In this
853      way only one interrupt is delivered to the kernel. Otherwise
854      the spurious second interrupt may cause the kernel to bring
855      down (vital) interrupt lines.
856
857      Only affects "broken" chipsets. Interrupt sharing may be
858      increased on these systems.
859
860config X86_MCE
861    bool "Machine Check / overheating reporting"
862    ---help---
863      Machine Check support allows the processor to notify the
864      kernel if it detects a problem (e.g. overheating, data corruption).
865      The action the kernel takes depends on the severity of the problem,
866      ranging from warning messages to halting the machine.
867
868config X86_MCE_INTEL
869    def_bool y
870    prompt "Intel MCE features"
871    depends on X86_MCE && X86_LOCAL_APIC
872    ---help---
873       Additional support for intel specific MCE features such as
874       the thermal monitor.
875
876config X86_MCE_AMD
877    def_bool y
878    prompt "AMD MCE features"
879    depends on X86_MCE && X86_LOCAL_APIC
880    ---help---
881       Additional support for AMD specific MCE features such as
882       the DRAM Error Threshold.
883
884config X86_ANCIENT_MCE
885    bool "Support for old Pentium 5 / WinChip machine checks"
886    depends on X86_32 && X86_MCE
887    ---help---
888      Include support for machine check handling on old Pentium 5 or WinChip
889      systems. These typically need to be enabled explicitely on the command
890      line.
891
892config X86_MCE_THRESHOLD
893    depends on X86_MCE_AMD || X86_MCE_INTEL
894    def_bool y
895
896config X86_MCE_INJECT
897    depends on X86_MCE
898    tristate "Machine check injector support"
899    ---help---
900      Provide support for injecting machine checks for testing purposes.
901      If you don't know what a machine check is and you don't do kernel
902      QA it is safe to say n.
903
904config X86_THERMAL_VECTOR
905    def_bool y
906    depends on X86_MCE_INTEL
907
908config VM86
909    bool "Enable VM86 support" if EMBEDDED
910    default y
911    depends on X86_32
912    ---help---
913      This option is required by programs like DOSEMU to run 16-bit legacy
914      code on X86 processors. It also may be needed by software like
915      XFree86 to initialize some video cards via BIOS. Disabling this
916      option saves about 6k.
917
918config TOSHIBA
919    tristate "Toshiba Laptop support"
920    depends on X86_32
921    ---help---
922      This adds a driver to safely access the System Management Mode of
923      the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
924      not work on models with a Phoenix BIOS. The System Management Mode
925      is used to set the BIOS and power saving options on Toshiba portables.
926
927      For information on utilities to make use of this driver see the
928      Toshiba Linux utilities web site at:
929      <http://www.buzzard.org.uk/toshiba/>.
930
931      Say Y if you intend to run this kernel on a Toshiba portable.
932      Say N otherwise.
933
934config I8K
935    tristate "Dell laptop support"
936    ---help---
937      This adds a driver to safely access the System Management Mode
938      of the CPU on the Dell Inspiron 8000. The System Management Mode
939      is used to read cpu temperature and cooling fan status and to
940      control the fans on the I8K portables.
941
942      This driver has been tested only on the Inspiron 8000 but it may
943      also work with other Dell laptops. You can force loading on other
944      models by passing the parameter `force=1' to the module. Use at
945      your own risk.
946
947      For information on utilities to make use of this driver see the
948      I8K Linux utilities web site at:
949      <http://people.debian.org/~dz/i8k/>
950
951      Say Y if you intend to run this kernel on a Dell Inspiron 8000.
952      Say N otherwise.
953
954config X86_REBOOTFIXUPS
955    bool "Enable X86 board specific fixups for reboot"
956    depends on X86_32
957    ---help---
958      This enables chipset and/or board specific fixups to be done
959      in order to get reboot to work correctly. This is only needed on
960      some combinations of hardware and BIOS. The symptom, for which
961      this config is intended, is when reboot ends with a stalled/hung
962      system.
963
964      Currently, the only fixup is for the Geode machines using
965      CS5530A and CS5536 chipsets and the RDC R-321x SoC.
966
967      Say Y if you want to enable the fixup. Currently, it's safe to
968      enable this option even if you don't need it.
969      Say N otherwise.
970
971config MICROCODE
972    tristate "/dev/cpu/microcode - microcode support"
973    select FW_LOADER
974    ---help---
975      If you say Y here, you will be able to update the microcode on
976      certain Intel and AMD processors. The Intel support is for the
977      IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
978      Pentium 4, Xeon etc. The AMD support is for family 0x10 and
979      0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
980      You will obviously need the actual microcode binary data itself
981      which is not shipped with the Linux kernel.
982
983      This option selects the general module only, you need to select
984      at least one vendor specific module as well.
985
986      To compile this driver as a module, choose M here: the
987      module will be called microcode.
988
989config MICROCODE_INTEL
990    bool "Intel microcode patch loading support"
991    depends on MICROCODE
992    default MICROCODE
993    select FW_LOADER
994    ---help---
995      This options enables microcode patch loading support for Intel
996      processors.
997
998      For latest news and information on obtaining all the required
999      Intel ingredients for this driver, check:
1000      <http://www.urbanmyth.org/microcode/>.
1001
1002config MICROCODE_AMD
1003    bool "AMD microcode patch loading support"
1004    depends on MICROCODE
1005    select FW_LOADER
1006    ---help---
1007      If you select this option, microcode patch loading support for AMD
1008      processors will be enabled.
1009
1010config MICROCODE_OLD_INTERFACE
1011    def_bool y
1012    depends on MICROCODE
1013
1014config X86_MSR
1015    tristate "/dev/cpu/*/msr - Model-specific register support"
1016    ---help---
1017      This device gives privileged processes access to the x86
1018      Model-Specific Registers (MSRs). It is a character device with
1019      major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1020      MSR accesses are directed to a specific CPU on multi-processor
1021      systems.
1022
1023config X86_CPUID
1024    tristate "/dev/cpu/*/cpuid - CPU information support"
1025    ---help---
1026      This device gives processes access to the x86 CPUID instruction to
1027      be executed on a specific processor. It is a character device
1028      with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1029      /dev/cpu/31/cpuid.
1030
1031choice
1032    prompt "High Memory Support"
1033    default HIGHMEM64G if X86_NUMAQ
1034    default HIGHMEM4G
1035    depends on X86_32
1036
1037config NOHIGHMEM
1038    bool "off"
1039    depends on !X86_NUMAQ
1040    ---help---
1041      Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1042      However, the address space of 32-bit x86 processors is only 4
1043      Gigabytes large. That means that, if you have a large amount of
1044      physical memory, not all of it can be "permanently mapped" by the
1045      kernel. The physical memory that's not permanently mapped is called
1046      "high memory".
1047
1048      If you are compiling a kernel which will never run on a machine with
1049      more than 1 Gigabyte total physical RAM, answer "off" here (default
1050      choice and suitable for most users). This will result in a "3GB/1GB"
1051      split: 3GB are mapped so that each process sees a 3GB virtual memory
1052      space and the remaining part of the 4GB virtual memory space is used
1053      by the kernel to permanently map as much physical memory as
1054      possible.
1055
1056      If the machine has between 1 and 4 Gigabytes physical RAM, then
1057      answer "4GB" here.
1058
1059      If more than 4 Gigabytes is used then answer "64GB" here. This
1060      selection turns Intel PAE (Physical Address Extension) mode on.
1061      PAE implements 3-level paging on IA32 processors. PAE is fully
1062      supported by Linux, PAE mode is implemented on all recent Intel
1063      processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1064      then the kernel will not boot on CPUs that don't support PAE!
1065
1066      The actual amount of total physical memory will either be
1067      auto detected or can be forced by using a kernel command line option
1068      such as "mem=256M". (Try "man bootparam" or see the documentation of
1069      your boot loader (lilo or loadlin) about how to pass options to the
1070      kernel at boot time.)
1071
1072      If unsure, say "off".
1073
1074config HIGHMEM4G
1075    bool "4GB"
1076    depends on !X86_NUMAQ
1077    ---help---
1078      Select this if you have a 32-bit processor and between 1 and 4
1079      gigabytes of physical RAM.
1080
1081config HIGHMEM64G
1082    bool "64GB"
1083    depends on !M386 && !M486
1084    select X86_PAE
1085    ---help---
1086      Select this if you have a 32-bit processor and more than 4
1087      gigabytes of physical RAM.
1088
1089endchoice
1090
1091choice
1092    depends on EXPERIMENTAL
1093    prompt "Memory split" if EMBEDDED
1094    default VMSPLIT_3G
1095    depends on X86_32
1096    ---help---
1097      Select the desired split between kernel and user memory.
1098
1099      If the address range available to the kernel is less than the
1100      physical memory installed, the remaining memory will be available
1101      as "high memory". Accessing high memory is a little more costly
1102      than low memory, as it needs to be mapped into the kernel first.
1103      Note that increasing the kernel address space limits the range
1104      available to user programs, making the address space there
1105      tighter. Selecting anything other than the default 3G/1G split
1106      will also likely make your kernel incompatible with binary-only
1107      kernel modules.
1108
1109      If you are not absolutely sure what you are doing, leave this
1110      option alone!
1111
1112    config VMSPLIT_3G
1113        bool "3G/1G user/kernel split"
1114    config VMSPLIT_3G_OPT
1115        depends on !X86_PAE
1116        bool "3G/1G user/kernel split (for full 1G low memory)"
1117    config VMSPLIT_2G
1118        bool "2G/2G user/kernel split"
1119    config VMSPLIT_2G_OPT
1120        depends on !X86_PAE
1121        bool "2G/2G user/kernel split (for full 2G low memory)"
1122    config VMSPLIT_1G
1123        bool "1G/3G user/kernel split"
1124endchoice
1125
1126config PAGE_OFFSET
1127    hex
1128    default 0xB0000000 if VMSPLIT_3G_OPT
1129    default 0x80000000 if VMSPLIT_2G
1130    default 0x78000000 if VMSPLIT_2G_OPT
1131    default 0x40000000 if VMSPLIT_1G
1132    default 0xC0000000
1133    depends on X86_32
1134
1135config HIGHMEM
1136    def_bool y
1137    depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1138
1139config X86_PAE
1140    bool "PAE (Physical Address Extension) Support"
1141    depends on X86_32 && !HIGHMEM4G
1142    ---help---
1143      PAE is required for NX support, and furthermore enables
1144      larger swapspace support for non-overcommit purposes. It
1145      has the cost of more pagetable lookup overhead, and also
1146      consumes more pagetable space per process.
1147
1148config ARCH_PHYS_ADDR_T_64BIT
1149    def_bool X86_64 || X86_PAE
1150
1151config DIRECT_GBPAGES
1152    bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1153    default y
1154    depends on X86_64
1155    ---help---
1156      Allow the kernel linear mapping to use 1GB pages on CPUs that
1157      support it. This can improve the kernel's performance a tiny bit by
1158      reducing TLB pressure. If in doubt, say "Y".
1159
1160# Common NUMA Features
1161config NUMA
1162    bool "Numa Memory Allocation and Scheduler Support"
1163    depends on SMP
1164    depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1165    default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1166    ---help---
1167      Enable NUMA (Non Uniform Memory Access) support.
1168
1169      The kernel will try to allocate memory used by a CPU on the
1170      local memory controller of the CPU and add some more
1171      NUMA awareness to the kernel.
1172
1173      For 64-bit this is recommended if the system is Intel Core i7
1174      (or later), AMD Opteron, or EM64T NUMA.
1175
1176      For 32-bit this is only needed on (rare) 32-bit-only platforms
1177      that support NUMA topologies, such as NUMAQ / Summit, or if you
1178      boot a 32-bit kernel on a 64-bit NUMA platform.
1179
1180      Otherwise, you should say N.
1181
1182comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1183    depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1184
1185config K8_NUMA
1186    def_bool y
1187    prompt "Old style AMD Opteron NUMA detection"
1188    depends on X86_64 && NUMA && PCI
1189    ---help---
1190      Enable K8 NUMA node topology detection. You should say Y here if
1191      you have a multi processor AMD K8 system. This uses an old
1192      method to read the NUMA configuration directly from the builtin
1193      Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1194      instead, which also takes priority if both are compiled in.
1195
1196config X86_64_ACPI_NUMA
1197    def_bool y
1198    prompt "ACPI NUMA detection"
1199    depends on X86_64 && NUMA && ACPI && PCI
1200    select ACPI_NUMA
1201    ---help---
1202      Enable ACPI SRAT based node topology detection.
1203
1204# Some NUMA nodes have memory ranges that span
1205# other nodes. Even though a pfn is valid and
1206# between a node's start and end pfns, it may not
1207# reside on that node. See memmap_init_zone()
1208# for details.
1209config NODES_SPAN_OTHER_NODES
1210    def_bool y
1211    depends on X86_64_ACPI_NUMA
1212
1213config NUMA_EMU
1214    bool "NUMA emulation"
1215    depends on X86_64 && NUMA
1216    ---help---
1217      Enable NUMA emulation. A flat machine will be split
1218      into virtual nodes when booted with "numa=fake=N", where N is the
1219      number of nodes. This is only useful for debugging.
1220
1221config NODES_SHIFT
1222    int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1223    range 1 10
1224    default "10" if MAXSMP
1225    default "6" if X86_64
1226    default "4" if X86_NUMAQ
1227    default "3"
1228    depends on NEED_MULTIPLE_NODES
1229    ---help---
1230      Specify the maximum number of NUMA Nodes available on the target
1231      system. Increases memory reserved to accommodate various tables.
1232
1233config HAVE_ARCH_BOOTMEM
1234    def_bool y
1235    depends on X86_32 && NUMA
1236
1237config ARCH_HAVE_MEMORY_PRESENT
1238    def_bool y
1239    depends on X86_32 && DISCONTIGMEM
1240
1241config NEED_NODE_MEMMAP_SIZE
1242    def_bool y
1243    depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1244
1245config HAVE_ARCH_ALLOC_REMAP
1246    def_bool y
1247    depends on X86_32 && NUMA
1248
1249config ARCH_FLATMEM_ENABLE
1250    def_bool y
1251    depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1252
1253config ARCH_DISCONTIGMEM_ENABLE
1254    def_bool y
1255    depends on NUMA && X86_32
1256
1257config ARCH_DISCONTIGMEM_DEFAULT
1258    def_bool y
1259    depends on NUMA && X86_32
1260
1261config ARCH_PROC_KCORE_TEXT
1262    def_bool y
1263    depends on X86_64 && PROC_KCORE
1264
1265config ARCH_SPARSEMEM_DEFAULT
1266    def_bool y
1267    depends on X86_64
1268
1269config ARCH_SPARSEMEM_ENABLE
1270    def_bool y
1271    depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1272    select SPARSEMEM_STATIC if X86_32
1273    select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1274
1275config ARCH_SELECT_MEMORY_MODEL
1276    def_bool y
1277    depends on ARCH_SPARSEMEM_ENABLE
1278
1279config ARCH_MEMORY_PROBE
1280    def_bool X86_64
1281    depends on MEMORY_HOTPLUG
1282
1283config ILLEGAL_POINTER_VALUE
1284       hex
1285       default 0 if X86_32
1286       default 0xdead000000000000 if X86_64
1287
1288source "mm/Kconfig"
1289
1290config HIGHPTE
1291    bool "Allocate 3rd-level pagetables from highmem"
1292    depends on HIGHMEM
1293    ---help---
1294      The VM uses one page table entry for each page of physical memory.
1295      For systems with a lot of RAM, this can be wasteful of precious
1296      low memory. Setting this option will put user-space page table
1297      entries in high memory.
1298
1299config X86_CHECK_BIOS_CORRUPTION
1300    bool "Check for low memory corruption"
1301    ---help---
1302      Periodically check for memory corruption in low memory, which
1303      is suspected to be caused by BIOS. Even when enabled in the
1304      configuration, it is disabled at runtime. Enable it by
1305      setting "memory_corruption_check=1" on the kernel command
1306      line. By default it scans the low 64k of memory every 60
1307      seconds; see the memory_corruption_check_size and
1308      memory_corruption_check_period parameters in
1309      Documentation/kernel-parameters.txt to adjust this.
1310
1311      When enabled with the default parameters, this option has
1312      almost no overhead, as it reserves a relatively small amount
1313      of memory and scans it infrequently. It both detects corruption
1314      and prevents it from affecting the running system.
1315
1316      It is, however, intended as a diagnostic tool; if repeatable
1317      BIOS-originated corruption always affects the same memory,
1318      you can use memmap= to prevent the kernel from using that
1319      memory.
1320
1321config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1322    bool "Set the default setting of memory_corruption_check"
1323    depends on X86_CHECK_BIOS_CORRUPTION
1324    default y
1325    ---help---
1326      Set whether the default state of memory_corruption_check is
1327      on or off.
1328
1329config X86_RESERVE_LOW_64K
1330    bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1331    default y
1332    ---help---
1333      Reserve the first 64K of physical RAM on BIOSes that are known
1334      to potentially corrupt that memory range. A numbers of BIOSes are
1335      known to utilize this area during suspend/resume, so it must not
1336      be used by the kernel.
1337
1338      Set this to N if you are absolutely sure that you trust the BIOS
1339      to get all its memory reservations and usages right.
1340
1341      If you have doubts about the BIOS (e.g. suspend/resume does not
1342      work or there's kernel crashes after certain hardware hotplug
1343      events) and it's not AMI or Phoenix, then you might want to enable
1344      X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1345      corruption patterns.
1346
1347      Say Y if unsure.
1348
1349config MATH_EMULATION
1350    bool
1351    prompt "Math emulation" if X86_32
1352    ---help---
1353      Linux can emulate a math coprocessor (used for floating point
1354      operations) if you don't have one. 486DX and Pentium processors have
1355      a math coprocessor built in, 486SX and 386 do not, unless you added
1356      a 487DX or 387, respectively. (The messages during boot time can
1357      give you some hints here ["man dmesg"].) Everyone needs either a
1358      coprocessor or this emulation.
1359
1360      If you don't have a math coprocessor, you need to say Y here; if you
1361      say Y here even though you have a coprocessor, the coprocessor will
1362      be used nevertheless. (This behavior can be changed with the kernel
1363      command line option "no387", which comes handy if your coprocessor
1364      is broken. Try "man bootparam" or see the documentation of your boot
1365      loader (lilo or loadlin) about how to pass options to the kernel at
1366      boot time.) This means that it is a good idea to say Y here if you
1367      intend to use this kernel on different machines.
1368
1369      More information about the internals of the Linux math coprocessor
1370      emulation can be found in <file:arch/x86/math-emu/README>.
1371
1372      If you are not sure, say Y; apart from resulting in a 66 KB bigger
1373      kernel, it won't hurt.
1374
1375config MTRR
1376    def_bool y
1377    prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1378    ---help---
1379      On Intel P6 family processors (Pentium Pro, Pentium II and later)
1380      the Memory Type Range Registers (MTRRs) may be used to control
1381      processor access to memory ranges. This is most useful if you have
1382      a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1383      allows bus write transfers to be combined into a larger transfer
1384      before bursting over the PCI/AGP bus. This can increase performance
1385      of image write operations 2.5 times or more. Saying Y here creates a
1386      /proc/mtrr file which may be used to manipulate your processor's
1387      MTRRs. Typically the X server should use this.
1388
1389      This code has a reasonably generic interface so that similar
1390      control registers on other processors can be easily supported
1391      as well:
1392
1393      The Cyrix 6x86, 6x86MX and M II processors have Address Range
1394      Registers (ARRs) which provide a similar functionality to MTRRs. For
1395      these, the ARRs are used to emulate the MTRRs.
1396      The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1397      MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1398      write-combining. All of these processors are supported by this code
1399      and it makes sense to say Y here if you have one of them.
1400
1401      Saying Y here also fixes a problem with buggy SMP BIOSes which only
1402      set the MTRRs for the boot CPU and not for the secondary CPUs. This
1403      can lead to all sorts of problems, so it's good to say Y here.
1404
1405      You can safely say Y even if your machine doesn't have MTRRs, you'll
1406      just add about 9 KB to your kernel.
1407
1408      See <file:Documentation/x86/mtrr.txt> for more information.
1409
1410config MTRR_SANITIZER
1411    def_bool y
1412    prompt "MTRR cleanup support"
1413    depends on MTRR
1414    ---help---
1415      Convert MTRR layout from continuous to discrete, so X drivers can
1416      add writeback entries.
1417
1418      Can be disabled with disable_mtrr_cleanup on the kernel command line.
1419      The largest mtrr entry size for a continuous block can be set with
1420      mtrr_chunk_size.
1421
1422      If unsure, say Y.
1423
1424config MTRR_SANITIZER_ENABLE_DEFAULT
1425    int "MTRR cleanup enable value (0-1)"
1426    range 0 1
1427    default "0"
1428    depends on MTRR_SANITIZER
1429    ---help---
1430      Enable mtrr cleanup default value
1431
1432config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1433    int "MTRR cleanup spare reg num (0-7)"
1434    range 0 7
1435    default "1"
1436    depends on MTRR_SANITIZER
1437    ---help---
1438      mtrr cleanup spare entries default, it can be changed via
1439      mtrr_spare_reg_nr=N on the kernel command line.
1440
1441config X86_PAT
1442    def_bool y
1443    prompt "x86 PAT support" if EMBEDDED
1444    depends on MTRR
1445    ---help---
1446      Use PAT attributes to setup page level cache control.
1447
1448      PATs are the modern equivalents of MTRRs and are much more
1449      flexible than MTRRs.
1450
1451      Say N here if you see bootup problems (boot crash, boot hang,
1452      spontaneous reboots) or a non-working video driver.
1453
1454      If unsure, say Y.
1455
1456config ARCH_USES_PG_UNCACHED
1457    def_bool y
1458    depends on X86_PAT
1459
1460config EFI
1461    bool "EFI runtime service support"
1462    depends on ACPI
1463    ---help---
1464      This enables the kernel to use EFI runtime services that are
1465      available (such as the EFI variable services).
1466
1467      This option is only useful on systems that have EFI firmware.
1468      In addition, you should use the latest ELILO loader available
1469      at <http://elilo.sourceforge.net> in order to take advantage
1470      of EFI runtime services. However, even with this option, the
1471      resultant kernel should continue to boot on existing non-EFI
1472      platforms.
1473
1474config SECCOMP
1475    def_bool y
1476    prompt "Enable seccomp to safely compute untrusted bytecode"
1477    ---help---
1478      This kernel feature is useful for number crunching applications
1479      that may need to compute untrusted bytecode during their
1480      execution. By using pipes or other transports made available to
1481      the process as file descriptors supporting the read/write
1482      syscalls, it's possible to isolate those applications in
1483      their own address space using seccomp. Once seccomp is
1484      enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1485      and the task is only allowed to execute a few safe syscalls
1486      defined by each seccomp mode.
1487
1488      If unsure, say Y. Only embedded should say N here.
1489
1490config CC_STACKPROTECTOR
1491    bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1492    ---help---
1493      This option turns on the -fstack-protector GCC feature. This
1494      feature puts, at the beginning of functions, a canary value on
1495      the stack just before the return address, and validates
1496      the value just before actually returning. Stack based buffer
1497      overflows (that need to overwrite this return address) now also
1498      overwrite the canary, which gets detected and the attack is then
1499      neutralized via a kernel panic.
1500
1501      This feature requires gcc version 4.2 or above, or a distribution
1502      gcc with the feature backported. Older versions are automatically
1503      detected and for those versions, this configuration option is
1504      ignored. (and a warning is printed during bootup)
1505
1506source kernel/Kconfig.hz
1507
1508config KEXEC
1509    bool "kexec system call"
1510    ---help---
1511      kexec is a system call that implements the ability to shutdown your
1512      current kernel, and to start another kernel. It is like a reboot
1513      but it is independent of the system firmware. And like a reboot
1514      you can start any kernel with it, not just Linux.
1515
1516      The name comes from the similarity to the exec system call.
1517
1518      It is an ongoing process to be certain the hardware in a machine
1519      is properly shutdown, so do not be surprised if this code does not
1520      initially work for you. It may help to enable device hotplugging
1521      support. As of this writing the exact hardware interface is
1522      strongly in flux, so no good recommendation can be made.
1523
1524config CRASH_DUMP
1525    bool "kernel crash dumps"
1526    depends on X86_64 || (X86_32 && HIGHMEM)
1527    ---help---
1528      Generate crash dump after being started by kexec.
1529      This should be normally only set in special crash dump kernels
1530      which are loaded in the main kernel with kexec-tools into
1531      a specially reserved region and then later executed after
1532      a crash by kdump/kexec. The crash dump kernel must be compiled
1533      to a memory address not used by the main kernel or BIOS using
1534      PHYSICAL_START, or it must be built as a relocatable image
1535      (CONFIG_RELOCATABLE=y).
1536      For more details see Documentation/kdump/kdump.txt
1537
1538config KEXEC_JUMP
1539    bool "kexec jump (EXPERIMENTAL)"
1540    depends on EXPERIMENTAL
1541    depends on KEXEC && HIBERNATION
1542    ---help---
1543      Jump between original kernel and kexeced kernel and invoke
1544      code in physical address mode via KEXEC
1545
1546config PHYSICAL_START
1547    hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1548    default "0x1000000"
1549    ---help---
1550      This gives the physical address where the kernel is loaded.
1551
1552      If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1553      bzImage will decompress itself to above physical address and
1554      run from there. Otherwise, bzImage will run from the address where
1555      it has been loaded by the boot loader and will ignore above physical
1556      address.
1557
1558      In normal kdump cases one does not have to set/change this option
1559      as now bzImage can be compiled as a completely relocatable image
1560      (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1561      address. This option is mainly useful for the folks who don't want
1562      to use a bzImage for capturing the crash dump and want to use a
1563      vmlinux instead. vmlinux is not relocatable hence a kernel needs
1564      to be specifically compiled to run from a specific memory area
1565      (normally a reserved region) and this option comes handy.
1566
1567      So if you are using bzImage for capturing the crash dump,
1568      leave the value here unchanged to 0x1000000 and set
1569      CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1570      for capturing the crash dump change this value to start of
1571      the reserved region. In other words, it can be set based on
1572      the "X" value as specified in the "crashkernel=YM@XM"
1573      command line boot parameter passed to the panic-ed
1574      kernel. Please take a look at Documentation/kdump/kdump.txt
1575      for more details about crash dumps.
1576
1577      Usage of bzImage for capturing the crash dump is recommended as
1578      one does not have to build two kernels. Same kernel can be used
1579      as production kernel and capture kernel. Above option should have
1580      gone away after relocatable bzImage support is introduced. But it
1581      is present because there are users out there who continue to use
1582      vmlinux for dump capture. This option should go away down the
1583      line.
1584
1585      Don't change this unless you know what you are doing.
1586
1587config RELOCATABLE
1588    bool "Build a relocatable kernel"
1589    default y
1590    ---help---
1591      This builds a kernel image that retains relocation information
1592      so it can be loaded someplace besides the default 1MB.
1593      The relocations tend to make the kernel binary about 10% larger,
1594      but are discarded at runtime.
1595
1596      One use is for the kexec on panic case where the recovery kernel
1597      must live at a different physical address than the primary
1598      kernel.
1599
1600      Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1601      it has been loaded at and the compile time physical address
1602      (CONFIG_PHYSICAL_START) is ignored.
1603
1604# Relocation on x86-32 needs some additional build support
1605config X86_NEED_RELOCS
1606    def_bool y
1607    depends on X86_32 && RELOCATABLE
1608
1609config PHYSICAL_ALIGN
1610    hex "Alignment value to which kernel should be aligned" if X86_32
1611    default "0x1000000"
1612    range 0x2000 0x1000000
1613    ---help---
1614      This value puts the alignment restrictions on physical address
1615      where kernel is loaded and run from. Kernel is compiled for an
1616      address which meets above alignment restriction.
1617
1618      If bootloader loads the kernel at a non-aligned address and
1619      CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1620      address aligned to above value and run from there.
1621
1622      If bootloader loads the kernel at a non-aligned address and
1623      CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1624      load address and decompress itself to the address it has been
1625      compiled for and run from there. The address for which kernel is
1626      compiled already meets above alignment restrictions. Hence the
1627      end result is that kernel runs from a physical address meeting
1628      above alignment restrictions.
1629
1630      Don't change this unless you know what you are doing.
1631
1632config HOTPLUG_CPU
1633    bool "Support for hot-pluggable CPUs"
1634    depends on SMP && HOTPLUG
1635    ---help---
1636      Say Y here to allow turning CPUs off and on. CPUs can be
1637      controlled through /sys/devices/system/cpu.
1638      ( Note: power management support will enable this option
1639        automatically on SMP systems. )
1640      Say N if you want to disable CPU hotplug.
1641
1642config COMPAT_VDSO
1643    def_bool y
1644    prompt "Compat VDSO support"
1645    depends on X86_32 || IA32_EMULATION
1646    ---help---
1647      Map the 32-bit VDSO to the predictable old-style address too.
1648
1649      Say N here if you are running a sufficiently recent glibc
1650      version (2.3.3 or later), to remove the high-mapped
1651      VDSO mapping and to exclusively use the randomized VDSO.
1652
1653      If unsure, say Y.
1654
1655config CMDLINE_BOOL
1656    bool "Built-in kernel command line"
1657    ---help---
1658      Allow for specifying boot arguments to the kernel at
1659      build time. On some systems (e.g. embedded ones), it is
1660      necessary or convenient to provide some or all of the
1661      kernel boot arguments with the kernel itself (that is,
1662      to not rely on the boot loader to provide them.)
1663
1664      To compile command line arguments into the kernel,
1665      set this option to 'Y', then fill in the
1666      the boot arguments in CONFIG_CMDLINE.
1667
1668      Systems with fully functional boot loaders (i.e. non-embedded)
1669      should leave this option set to 'N'.
1670
1671config CMDLINE
1672    string "Built-in kernel command string"
1673    depends on CMDLINE_BOOL
1674    default ""
1675    ---help---
1676      Enter arguments here that should be compiled into the kernel
1677      image and used at boot time. If the boot loader provides a
1678      command line at boot time, it is appended to this string to
1679      form the full kernel command line, when the system boots.
1680
1681      However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1682      change this behavior.
1683
1684      In most cases, the command line (whether built-in or provided
1685      by the boot loader) should specify the device for the root
1686      file system.
1687
1688config CMDLINE_OVERRIDE
1689    bool "Built-in command line overrides boot loader arguments"
1690    depends on CMDLINE_BOOL
1691    ---help---
1692      Set this option to 'Y' to have the kernel ignore the boot loader
1693      command line, and use ONLY the built-in command line.
1694
1695      This is used to work around broken boot loaders. This should
1696      be set to 'N' under normal conditions.
1697
1698endmenu
1699
1700config ARCH_ENABLE_MEMORY_HOTPLUG
1701    def_bool y
1702    depends on X86_64 || (X86_32 && HIGHMEM)
1703
1704config ARCH_ENABLE_MEMORY_HOTREMOVE
1705    def_bool y
1706    depends on MEMORY_HOTPLUG
1707
1708config HAVE_ARCH_EARLY_PFN_TO_NID
1709    def_bool X86_64
1710    depends on NUMA
1711
1712config USE_PERCPU_NUMA_NODE_ID
1713    def_bool X86_64
1714    depends on NUMA
1715
1716menu "Power management and ACPI options"
1717
1718config ARCH_HIBERNATION_HEADER
1719    def_bool y
1720    depends on X86_64 && HIBERNATION
1721
1722source "kernel/power/Kconfig"
1723
1724source "drivers/acpi/Kconfig"
1725
1726source "drivers/sfi/Kconfig"
1727
1728config X86_APM_BOOT
1729    def_bool y
1730    depends on APM || APM_MODULE
1731
1732menuconfig APM
1733    tristate "APM (Advanced Power Management) BIOS support"
1734    depends on X86_32 && PM_SLEEP
1735    ---help---
1736      APM is a BIOS specification for saving power using several different
1737      techniques. This is mostly useful for battery powered laptops with
1738      APM compliant BIOSes. If you say Y here, the system time will be
1739      reset after a RESUME operation, the /proc/apm device will provide
1740      battery status information, and user-space programs will receive
1741      notification of APM "events" (e.g. battery status change).
1742
1743      If you select "Y" here, you can disable actual use of the APM
1744      BIOS by passing the "apm=off" option to the kernel at boot time.
1745
1746      Note that the APM support is almost completely disabled for
1747      machines with more than one CPU.
1748
1749      In order to use APM, you will need supporting software. For location
1750      and more information, read <file:Documentation/power/pm.txt> and the
1751      Battery Powered Linux mini-HOWTO, available from
1752      <http://www.tldp.org/docs.html#howto>.
1753
1754      This driver does not spin down disk drives (see the hdparm(8)
1755      manpage ("man 8 hdparm") for that), and it doesn't turn off
1756      VESA-compliant "green" monitors.
1757
1758      This driver does not support the TI 4000M TravelMate and the ACER
1759      486/DX4/75 because they don't have compliant BIOSes. Many "green"
1760      desktop machines also don't have compliant BIOSes, and this driver
1761      may cause those machines to panic during the boot phase.
1762
1763      Generally, if you don't have a battery in your machine, there isn't
1764      much point in using this driver and you should say N. If you get
1765      random kernel OOPSes or reboots that don't seem to be related to
1766      anything, try disabling/enabling this option (or disabling/enabling
1767      APM in your BIOS).
1768
1769      Some other things you should try when experiencing seemingly random,
1770      "weird" problems:
1771
1772      1) make sure that you have enough swap space and that it is
1773      enabled.
1774      2) pass the "no-hlt" option to the kernel
1775      3) switch on floating point emulation in the kernel and pass
1776      the "no387" option to the kernel
1777      4) pass the "floppy=nodma" option to the kernel
1778      5) pass the "mem=4M" option to the kernel (thereby disabling
1779      all but the first 4 MB of RAM)
1780      6) make sure that the CPU is not over clocked.
1781      7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1782      8) disable the cache from your BIOS settings
1783      9) install a fan for the video card or exchange video RAM
1784      10) install a better fan for the CPU
1785      11) exchange RAM chips
1786      12) exchange the motherboard.
1787
1788      To compile this driver as a module, choose M here: the
1789      module will be called apm.
1790
1791if APM
1792
1793config APM_IGNORE_USER_SUSPEND
1794    bool "Ignore USER SUSPEND"
1795    ---help---
1796      This option will ignore USER SUSPEND requests. On machines with a
1797      compliant APM BIOS, you want to say N. However, on the NEC Versa M
1798      series notebooks, it is necessary to say Y because of a BIOS bug.
1799
1800config APM_DO_ENABLE
1801    bool "Enable PM at boot time"
1802    ---help---
1803      Enable APM features at boot time. From page 36 of the APM BIOS
1804      specification: "When disabled, the APM BIOS does not automatically
1805      power manage devices, enter the Standby State, enter the Suspend
1806      State, or take power saving steps in response to CPU Idle calls."
1807      This driver will make CPU Idle calls when Linux is idle (unless this
1808      feature is turned off -- see "Do CPU IDLE calls", below). This
1809      should always save battery power, but more complicated APM features
1810      will be dependent on your BIOS implementation. You may need to turn
1811      this option off if your computer hangs at boot time when using APM
1812      support, or if it beeps continuously instead of suspending. Turn
1813      this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1814      T400CDT. This is off by default since most machines do fine without
1815      this feature.
1816
1817config APM_CPU_IDLE
1818    bool "Make CPU Idle calls when idle"
1819    ---help---
1820      Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1821      On some machines, this can activate improved power savings, such as
1822      a slowed CPU clock rate, when the machine is idle. These idle calls
1823      are made after the idle loop has run for some length of time (e.g.,
1824      333 mS). On some machines, this will cause a hang at boot time or
1825      whenever the CPU becomes idle. (On machines with more than one CPU,
1826      this option does nothing.)
1827
1828config APM_DISPLAY_BLANK
1829    bool "Enable console blanking using APM"
1830    ---help---
1831      Enable console blanking using the APM. Some laptops can use this to
1832      turn off the LCD backlight when the screen blanker of the Linux
1833      virtual console blanks the screen. Note that this is only used by
1834      the virtual console screen blanker, and won't turn off the backlight
1835      when using the X Window system. This also doesn't have anything to
1836      do with your VESA-compliant power-saving monitor. Further, this
1837      option doesn't work for all laptops -- it might not turn off your
1838      backlight at all, or it might print a lot of errors to the console,
1839      especially if you are using gpm.
1840
1841config APM_ALLOW_INTS
1842    bool "Allow interrupts during APM BIOS calls"
1843    ---help---
1844      Normally we disable external interrupts while we are making calls to
1845      the APM BIOS as a measure to lessen the effects of a badly behaving
1846      BIOS implementation. The BIOS should reenable interrupts if it
1847      needs to. Unfortunately, some BIOSes do not -- especially those in
1848      many of the newer IBM Thinkpads. If you experience hangs when you
1849      suspend, try setting this to Y. Otherwise, say N.
1850
1851endif # APM
1852
1853source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1854
1855source "drivers/cpuidle/Kconfig"
1856
1857source "drivers/idle/Kconfig"
1858
1859endmenu
1860
1861
1862menu "Bus options (PCI etc.)"
1863
1864config PCI
1865    bool "PCI support"
1866    default y
1867    select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1868    ---help---
1869      Find out whether you have a PCI motherboard. PCI is the name of a
1870      bus system, i.e. the way the CPU talks to the other stuff inside
1871      your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1872      VESA. If you have PCI, say Y, otherwise N.
1873
1874choice
1875    prompt "PCI access mode"
1876    depends on X86_32 && PCI
1877    default PCI_GOANY
1878    ---help---
1879      On PCI systems, the BIOS can be used to detect the PCI devices and
1880      determine their configuration. However, some old PCI motherboards
1881      have BIOS bugs and may crash if this is done. Also, some embedded
1882      PCI-based systems don't have any BIOS at all. Linux can also try to
1883      detect the PCI hardware directly without using the BIOS.
1884
1885      With this option, you can specify how Linux should detect the
1886      PCI devices. If you choose "BIOS", the BIOS will be used,
1887      if you choose "Direct", the BIOS won't be used, and if you
1888      choose "MMConfig", then PCI Express MMCONFIG will be used.
1889      If you choose "Any", the kernel will try MMCONFIG, then the
1890      direct access method and falls back to the BIOS if that doesn't
1891      work. If unsure, go with the default, which is "Any".
1892
1893config PCI_GOBIOS
1894    bool "BIOS"
1895
1896config PCI_GOMMCONFIG
1897    bool "MMConfig"
1898
1899config PCI_GODIRECT
1900    bool "Direct"
1901
1902config PCI_GOOLPC
1903    bool "OLPC"
1904    depends on OLPC
1905
1906config PCI_GOANY
1907    bool "Any"
1908
1909endchoice
1910
1911config PCI_BIOS
1912    def_bool y
1913    depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1914
1915# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1916config PCI_DIRECT
1917    def_bool y
1918    depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1919
1920config PCI_MMCONFIG
1921    def_bool y
1922    depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1923
1924config PCI_OLPC
1925    def_bool y
1926    depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1927
1928config PCI_DOMAINS
1929    def_bool y
1930    depends on PCI
1931
1932config PCI_MMCONFIG
1933    bool "Support mmconfig PCI config space access"
1934    depends on X86_64 && PCI && ACPI
1935
1936config PCI_CNB20LE_QUIRK
1937    bool "Read CNB20LE Host Bridge Windows"
1938    depends on PCI
1939    help
1940      Read the PCI windows out of the CNB20LE host bridge. This allows
1941      PCI hotplug to work on systems with the CNB20LE chipset which do
1942      not have ACPI.
1943
1944config DMAR
1945    bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1946    depends on PCI_MSI && ACPI && EXPERIMENTAL
1947    help
1948      DMA remapping (DMAR) devices support enables independent address
1949      translations for Direct Memory Access (DMA) from devices.
1950      These DMA remapping devices are reported via ACPI tables
1951      and include PCI device scope covered by these DMA
1952      remapping devices.
1953
1954config DMAR_DEFAULT_ON
1955    def_bool y
1956    prompt "Enable DMA Remapping Devices by default"
1957    depends on DMAR
1958    help
1959      Selecting this option will enable a DMAR device at boot time if
1960      one is found. If this option is not selected, DMAR support can
1961      be enabled by passing intel_iommu=on to the kernel. It is
1962      recommended you say N here while the DMAR code remains
1963      experimental.
1964
1965config DMAR_BROKEN_GFX_WA
1966    bool "Workaround broken graphics drivers (going away soon)"
1967    depends on DMAR && BROKEN
1968    ---help---
1969      Current Graphics drivers tend to use physical address
1970      for DMA and avoid using DMA APIs. Setting this config
1971      option permits the IOMMU driver to set a unity map for
1972      all the OS-visible memory. Hence the driver can continue
1973      to use physical addresses for DMA, at least until this
1974      option is removed in the 2.6.32 kernel.
1975
1976config DMAR_FLOPPY_WA
1977    def_bool y
1978    depends on DMAR
1979    ---help---
1980      Floppy disk drivers are known to bypass DMA API calls
1981      thereby failing to work when IOMMU is enabled. This
1982      workaround will setup a 1:1 mapping for the first
1983      16MiB to make floppy (an ISA device) work.
1984
1985config INTR_REMAP
1986    bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1987    depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1988    ---help---
1989      Supports Interrupt remapping for IO-APIC and MSI devices.
1990      To use x2apic mode in the CPU's which support x2APIC enhancements or
1991      to support platforms with CPU's having > 8 bit APIC ID, say Y.
1992
1993source "drivers/pci/pcie/Kconfig"
1994
1995source "drivers/pci/Kconfig"
1996
1997# x86_64 have no ISA slots, but do have ISA-style DMA.
1998config ISA_DMA_API
1999    def_bool y
2000
2001if X86_32
2002
2003config ISA
2004    bool "ISA support"
2005    ---help---
2006      Find out whether you have ISA slots on your motherboard. ISA is the
2007      name of a bus system, i.e. the way the CPU talks to the other stuff
2008      inside your box. Other bus systems are PCI, EISA, MicroChannel
2009      (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2010      newer boards don't support it. If you have ISA, say Y, otherwise N.
2011
2012config EISA
2013    bool "EISA support"
2014    depends on ISA
2015    ---help---
2016      The Extended Industry Standard Architecture (EISA) bus was
2017      developed as an open alternative to the IBM MicroChannel bus.
2018
2019      The EISA bus provided some of the features of the IBM MicroChannel
2020      bus while maintaining backward compatibility with cards made for
2021      the older ISA bus. The EISA bus saw limited use between 1988 and
2022      1995 when it was made obsolete by the PCI bus.
2023
2024      Say Y here if you are building a kernel for an EISA-based machine.
2025
2026      Otherwise, say N.
2027
2028source "drivers/eisa/Kconfig"
2029
2030config MCA
2031    bool "MCA support"
2032    ---help---
2033      MicroChannel Architecture is found in some IBM PS/2 machines and
2034      laptops. It is a bus system similar to PCI or ISA. See
2035      <file:Documentation/mca.txt> (and especially the web page given
2036      there) before attempting to build an MCA bus kernel.
2037
2038source "drivers/mca/Kconfig"
2039
2040config SCx200
2041    tristate "NatSemi SCx200 support"
2042    ---help---
2043      This provides basic support for National Semiconductor's
2044      (now AMD's) Geode processors. The driver probes for the
2045      PCI-IDs of several on-chip devices, so its a good dependency
2046      for other scx200_* drivers.
2047
2048      If compiled as a module, the driver is named scx200.
2049
2050config SCx200HR_TIMER
2051    tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2052    depends on SCx200
2053    default y
2054    ---help---
2055      This driver provides a clocksource built upon the on-chip
2056      27MHz high-resolution timer. Its also a workaround for
2057      NSC Geode SC-1100's buggy TSC, which loses time when the
2058      processor goes idle (as is done by the scheduler). The
2059      other workaround is idle=poll boot option.
2060
2061config OLPC
2062    bool "One Laptop Per Child support"
2063    select GPIOLIB
2064    ---help---
2065      Add support for detecting the unique features of the OLPC
2066      XO hardware.
2067
2068config OLPC_OPENFIRMWARE
2069    bool "Support for OLPC's Open Firmware"
2070    depends on !X86_64 && !X86_PAE
2071    default y if OLPC
2072    help
2073      This option adds support for the implementation of Open Firmware
2074      that is used on the OLPC XO-1 Children's Machine.
2075      If unsure, say N here.
2076
2077endif # X86_32
2078
2079config K8_NB
2080    def_bool y
2081    depends on CPU_SUP_AMD && PCI
2082
2083source "drivers/pcmcia/Kconfig"
2084
2085source "drivers/pci/hotplug/Kconfig"
2086
2087endmenu
2088
2089
2090menu "Executable file formats / Emulations"
2091
2092source "fs/Kconfig.binfmt"
2093
2094config IA32_EMULATION
2095    bool "IA32 Emulation"
2096    depends on X86_64
2097    select COMPAT_BINFMT_ELF
2098    ---help---
2099      Include code to run 32-bit programs under a 64-bit kernel. You should
2100      likely turn this on, unless you're 100% sure that you don't have any
2101      32-bit programs left.
2102
2103config IA32_AOUT
2104    tristate "IA32 a.out support"
2105    depends on IA32_EMULATION
2106    ---help---
2107      Support old a.out binaries in the 32bit emulation.
2108
2109config COMPAT
2110    def_bool y
2111    depends on IA32_EMULATION
2112
2113config COMPAT_FOR_U64_ALIGNMENT
2114    def_bool COMPAT
2115    depends on X86_64
2116
2117config SYSVIPC_COMPAT
2118    def_bool y
2119    depends on COMPAT && SYSVIPC
2120
2121endmenu
2122
2123
2124config HAVE_ATOMIC_IOMAP
2125    def_bool y
2126    depends on X86_32
2127
2128source "net/Kconfig"
2129
2130source "drivers/Kconfig"
2131
2132source "drivers/firmware/Kconfig"
2133
2134source "fs/Kconfig"
2135
2136source "arch/x86/Kconfig.debug"
2137
2138source "security/Kconfig"
2139
2140source "crypto/Kconfig"
2141
2142source "arch/x86/kvm/Kconfig"
2143
2144source "lib/Kconfig"
2145

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