Version:  2.0.40 2.2.26 2.4.37 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19

Linux/arch/x86/Kconfig

  1 # Select 32 or 64 bit
  2 config 64BIT
  3         bool "64-bit kernel" if ARCH = "x86"
  4         default ARCH != "i386"
  5         ---help---
  6           Say yes to build a 64-bit kernel - formerly known as x86_64
  7           Say no to build a 32-bit kernel - formerly known as i386
  8 
  9 config X86_32
 10         def_bool y
 11         depends on !64BIT
 12         select CLKSRC_I8253
 13         select HAVE_UID16
 14 
 15 config X86_64
 16         def_bool y
 17         depends on 64BIT
 18         select X86_DEV_DMA_OPS
 19         select ARCH_USE_CMPXCHG_LOCKREF
 20 
 21 ### Arch settings
 22 config X86
 23         def_bool y
 24         select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 25         select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 26         select ARCH_HAS_FAST_MULTIPLIER
 27         select ARCH_HAS_GCOV_PROFILE_ALL
 28         select ARCH_MIGHT_HAVE_PC_PARPORT
 29         select ARCH_MIGHT_HAVE_PC_SERIO
 30         select HAVE_AOUT if X86_32
 31         select HAVE_UNSTABLE_SCHED_CLOCK
 32         select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
 33         select ARCH_SUPPORTS_INT128 if X86_64
 34         select HAVE_IDE
 35         select HAVE_OPROFILE
 36         select HAVE_PCSPKR_PLATFORM
 37         select HAVE_PERF_EVENTS
 38         select HAVE_IOREMAP_PROT
 39         select HAVE_KPROBES
 40         select HAVE_MEMBLOCK
 41         select HAVE_MEMBLOCK_NODE_MAP
 42         select ARCH_DISCARD_MEMBLOCK
 43         select ARCH_WANT_OPTIONAL_GPIOLIB
 44         select ARCH_WANT_FRAME_POINTERS
 45         select HAVE_DMA_ATTRS
 46         select HAVE_DMA_CONTIGUOUS
 47         select HAVE_KRETPROBES
 48         select GENERIC_EARLY_IOREMAP
 49         select HAVE_OPTPROBES
 50         select HAVE_KPROBES_ON_FTRACE
 51         select HAVE_FTRACE_MCOUNT_RECORD
 52         select HAVE_FENTRY if X86_64
 53         select HAVE_C_RECORDMCOUNT
 54         select HAVE_DYNAMIC_FTRACE
 55         select HAVE_DYNAMIC_FTRACE_WITH_REGS
 56         select HAVE_FUNCTION_TRACER
 57         select HAVE_FUNCTION_GRAPH_TRACER
 58         select HAVE_FUNCTION_GRAPH_FP_TEST
 59         select HAVE_SYSCALL_TRACEPOINTS
 60         select SYSCTL_EXCEPTION_TRACE
 61         select HAVE_KVM
 62         select HAVE_ARCH_KGDB
 63         select HAVE_ARCH_TRACEHOOK
 64         select HAVE_GENERIC_DMA_COHERENT if X86_32
 65         select HAVE_EFFICIENT_UNALIGNED_ACCESS
 66         select USER_STACKTRACE_SUPPORT
 67         select HAVE_REGS_AND_STACK_ACCESS_API
 68         select HAVE_DMA_API_DEBUG
 69         select HAVE_KERNEL_GZIP
 70         select HAVE_KERNEL_BZIP2
 71         select HAVE_KERNEL_LZMA
 72         select HAVE_KERNEL_XZ
 73         select HAVE_KERNEL_LZO
 74         select HAVE_KERNEL_LZ4
 75         select HAVE_HW_BREAKPOINT
 76         select HAVE_MIXED_BREAKPOINTS_REGS
 77         select PERF_EVENTS
 78         select HAVE_PERF_EVENTS_NMI
 79         select HAVE_PERF_REGS
 80         select HAVE_PERF_USER_STACK_DUMP
 81         select HAVE_DEBUG_KMEMLEAK
 82         select ANON_INODES
 83         select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 84         select HAVE_CMPXCHG_LOCAL
 85         select HAVE_CMPXCHG_DOUBLE
 86         select HAVE_ARCH_KMEMCHECK
 87         select HAVE_USER_RETURN_NOTIFIER
 88         select ARCH_BINFMT_ELF_RANDOMIZE_PIE
 89         select HAVE_ARCH_JUMP_LABEL
 90         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 91         select SPARSE_IRQ
 92         select GENERIC_FIND_FIRST_BIT
 93         select GENERIC_IRQ_PROBE
 94         select GENERIC_PENDING_IRQ if SMP
 95         select GENERIC_IRQ_SHOW
 96         select GENERIC_CLOCKEVENTS_MIN_ADJUST
 97         select IRQ_FORCED_THREADING
 98         select HAVE_BPF_JIT if X86_64
 99         select HAVE_ARCH_TRANSPARENT_HUGEPAGE
100         select ARCH_HAS_SG_CHAIN
101         select CLKEVT_I8253
102         select ARCH_HAVE_NMI_SAFE_CMPXCHG
103         select GENERIC_IOMAP
104         select DCACHE_WORD_ACCESS
105         select GENERIC_SMP_IDLE_THREAD
106         select ARCH_WANT_IPC_PARSE_VERSION if X86_32
107         select HAVE_ARCH_SECCOMP_FILTER
108         select BUILDTIME_EXTABLE_SORT
109         select GENERIC_CMOS_UPDATE
110         select HAVE_ARCH_SOFT_DIRTY if X86_64
111         select CLOCKSOURCE_WATCHDOG
112         select GENERIC_CLOCKEVENTS
113         select ARCH_CLOCKSOURCE_DATA
114         select CLOCKSOURCE_VALIDATE_LAST_CYCLE
115         select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
116         select GENERIC_TIME_VSYSCALL
117         select GENERIC_STRNCPY_FROM_USER
118         select GENERIC_STRNLEN_USER
119         select HAVE_CONTEXT_TRACKING if X86_64
120         select HAVE_IRQ_TIME_ACCOUNTING
121         select VIRT_TO_BUS
122         select MODULES_USE_ELF_REL if X86_32
123         select MODULES_USE_ELF_RELA if X86_64
124         select CLONE_BACKWARDS if X86_32
125         select ARCH_USE_BUILTIN_BSWAP
126         select ARCH_USE_QUEUE_RWLOCK
127         select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
128         select OLD_SIGACTION if X86_32
129         select COMPAT_OLD_SIGACTION if IA32_EMULATION
130         select RTC_LIB
131         select HAVE_DEBUG_STACKOVERFLOW
132         select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
133         select HAVE_CC_STACKPROTECTOR
134         select GENERIC_CPU_AUTOPROBE
135         select HAVE_ARCH_AUDITSYSCALL
136         select ARCH_SUPPORTS_ATOMIC_RMW
137         select HAVE_ACPI_APEI if ACPI
138         select HAVE_ACPI_APEI_NMI if ACPI
139         select ACPI_LEGACY_TABLES_LOOKUP if ACPI
140         select X86_FEATURE_NAMES if PROC_FS
141 
142 config INSTRUCTION_DECODER
143         def_bool y
144         depends on KPROBES || PERF_EVENTS || UPROBES
145 
146 config PERF_EVENTS_INTEL_UNCORE
147         def_bool y
148         depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
149 
150 config OUTPUT_FORMAT
151         string
152         default "elf32-i386" if X86_32
153         default "elf64-x86-64" if X86_64
154 
155 config ARCH_DEFCONFIG
156         string
157         default "arch/x86/configs/i386_defconfig" if X86_32
158         default "arch/x86/configs/x86_64_defconfig" if X86_64
159 
160 config LOCKDEP_SUPPORT
161         def_bool y
162 
163 config STACKTRACE_SUPPORT
164         def_bool y
165 
166 config HAVE_LATENCYTOP_SUPPORT
167         def_bool y
168 
169 config MMU
170         def_bool y
171 
172 config SBUS
173         bool
174 
175 config NEED_DMA_MAP_STATE
176         def_bool y
177         depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
178 
179 config NEED_SG_DMA_LENGTH
180         def_bool y
181 
182 config GENERIC_ISA_DMA
183         def_bool y
184         depends on ISA_DMA_API
185 
186 config GENERIC_BUG
187         def_bool y
188         depends on BUG
189         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
190 
191 config GENERIC_BUG_RELATIVE_POINTERS
192         bool
193 
194 config GENERIC_HWEIGHT
195         def_bool y
196 
197 config ARCH_MAY_HAVE_PC_FDC
198         def_bool y
199         depends on ISA_DMA_API
200 
201 config RWSEM_XCHGADD_ALGORITHM
202         def_bool y
203 
204 config GENERIC_CALIBRATE_DELAY
205         def_bool y
206 
207 config ARCH_HAS_CPU_RELAX
208         def_bool y
209 
210 config ARCH_HAS_CACHE_LINE_SIZE
211         def_bool y
212 
213 config HAVE_SETUP_PER_CPU_AREA
214         def_bool y
215 
216 config NEED_PER_CPU_EMBED_FIRST_CHUNK
217         def_bool y
218 
219 config NEED_PER_CPU_PAGE_FIRST_CHUNK
220         def_bool y
221 
222 config ARCH_HIBERNATION_POSSIBLE
223         def_bool y
224 
225 config ARCH_SUSPEND_POSSIBLE
226         def_bool y
227 
228 config ARCH_WANT_HUGE_PMD_SHARE
229         def_bool y
230 
231 config ARCH_WANT_GENERAL_HUGETLB
232         def_bool y
233 
234 config ZONE_DMA32
235         bool
236         default X86_64
237 
238 config AUDIT_ARCH
239         bool
240         default X86_64
241 
242 config ARCH_SUPPORTS_OPTIMIZED_INLINING
243         def_bool y
244 
245 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
246         def_bool y
247 
248 config HAVE_INTEL_TXT
249         def_bool y
250         depends on INTEL_IOMMU && ACPI
251 
252 config X86_32_SMP
253         def_bool y
254         depends on X86_32 && SMP
255 
256 config X86_64_SMP
257         def_bool y
258         depends on X86_64 && SMP
259 
260 config X86_HT
261         def_bool y
262         depends on SMP
263 
264 config X86_32_LAZY_GS
265         def_bool y
266         depends on X86_32 && !CC_STACKPROTECTOR
267 
268 config ARCH_HWEIGHT_CFLAGS
269         string
270         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
271         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
272 
273 config ARCH_SUPPORTS_UPROBES
274         def_bool y
275 
276 config FIX_EARLYCON_MEM
277         def_bool y
278 
279 source "init/Kconfig"
280 source "kernel/Kconfig.freezer"
281 
282 menu "Processor type and features"
283 
284 config ZONE_DMA
285         bool "DMA memory allocation support" if EXPERT
286         default y
287         help
288           DMA memory allocation support allows devices with less than 32-bit
289           addressing to allocate within the first 16MB of address space.
290           Disable if no such devices will be used.
291 
292           If unsure, say Y.
293 
294 config SMP
295         bool "Symmetric multi-processing support"
296         ---help---
297           This enables support for systems with more than one CPU. If you have
298           a system with only one CPU, say N. If you have a system with more
299           than one CPU, say Y.
300 
301           If you say N here, the kernel will run on uni- and multiprocessor
302           machines, but will use only one CPU of a multiprocessor machine. If
303           you say Y here, the kernel will run on many, but not all,
304           uniprocessor machines. On a uniprocessor machine, the kernel
305           will run faster if you say N here.
306 
307           Note that if you say Y here and choose architecture "586" or
308           "Pentium" under "Processor family", the kernel will not work on 486
309           architectures. Similarly, multiprocessor kernels for the "PPro"
310           architecture may not work on all Pentium based boards.
311 
312           People using multiprocessor machines who say Y here should also say
313           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
314           Management" code will be disabled if you say Y here.
315 
316           See also <file:Documentation/x86/i386/IO-APIC.txt>,
317           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
318           <http://www.tldp.org/docs.html#howto>.
319 
320           If you don't know what to do here, say N.
321 
322 config X86_FEATURE_NAMES
323         bool "Processor feature human-readable names" if EMBEDDED
324         default y
325         ---help---
326           This option compiles in a table of x86 feature bits and corresponding
327           names.  This is required to support /proc/cpuinfo and a few kernel
328           messages.  You can disable this to save space, at the expense of
329           making those few kernel messages show numeric feature bits instead.
330 
331           If in doubt, say Y.
332 
333 config X86_X2APIC
334         bool "Support x2apic"
335         depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
336         ---help---
337           This enables x2apic support on CPUs that have this feature.
338 
339           This allows 32-bit apic IDs (so it can support very large systems),
340           and accesses the local apic via MSRs not via mmio.
341 
342           If you don't know what to do here, say N.
343 
344 config X86_MPPARSE
345         bool "Enable MPS table" if ACPI || SFI
346         default y
347         depends on X86_LOCAL_APIC
348         ---help---
349           For old smp systems that do not have proper acpi support. Newer systems
350           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
351 
352 config X86_BIGSMP
353         bool "Support for big SMP systems with more than 8 CPUs"
354         depends on X86_32 && SMP
355         ---help---
356           This option is needed for the systems that have more than 8 CPUs
357 
358 config GOLDFISH
359        def_bool y
360        depends on X86_GOLDFISH
361 
362 if X86_32
363 config X86_EXTENDED_PLATFORM
364         bool "Support for extended (non-PC) x86 platforms"
365         default y
366         ---help---
367           If you disable this option then the kernel will only support
368           standard PC platforms. (which covers the vast majority of
369           systems out there.)
370 
371           If you enable this option then you'll be able to select support
372           for the following (non-PC) 32 bit x86 platforms:
373                 Goldfish (Android emulator)
374                 AMD Elan
375                 RDC R-321x SoC
376                 SGI 320/540 (Visual Workstation)
377                 STA2X11-based (e.g. Northville)
378                 Moorestown MID devices
379 
380           If you have one of these systems, or if you want to build a
381           generic distribution kernel, say Y here - otherwise say N.
382 endif
383 
384 if X86_64
385 config X86_EXTENDED_PLATFORM
386         bool "Support for extended (non-PC) x86 platforms"
387         default y
388         ---help---
389           If you disable this option then the kernel will only support
390           standard PC platforms. (which covers the vast majority of
391           systems out there.)
392 
393           If you enable this option then you'll be able to select support
394           for the following (non-PC) 64 bit x86 platforms:
395                 Numascale NumaChip
396                 ScaleMP vSMP
397                 SGI Ultraviolet
398 
399           If you have one of these systems, or if you want to build a
400           generic distribution kernel, say Y here - otherwise say N.
401 endif
402 # This is an alphabetically sorted list of 64 bit extended platforms
403 # Please maintain the alphabetic order if and when there are additions
404 config X86_NUMACHIP
405         bool "Numascale NumaChip"
406         depends on X86_64
407         depends on X86_EXTENDED_PLATFORM
408         depends on NUMA
409         depends on SMP
410         depends on X86_X2APIC
411         depends on PCI_MMCONFIG
412         ---help---
413           Adds support for Numascale NumaChip large-SMP systems. Needed to
414           enable more than ~168 cores.
415           If you don't have one of these, you should say N here.
416 
417 config X86_VSMP
418         bool "ScaleMP vSMP"
419         select HYPERVISOR_GUEST
420         select PARAVIRT
421         depends on X86_64 && PCI
422         depends on X86_EXTENDED_PLATFORM
423         depends on SMP
424         ---help---
425           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
426           supposed to run on these EM64T-based machines.  Only choose this option
427           if you have one of these machines.
428 
429 config X86_UV
430         bool "SGI Ultraviolet"
431         depends on X86_64
432         depends on X86_EXTENDED_PLATFORM
433         depends on NUMA
434         depends on X86_X2APIC
435         ---help---
436           This option is needed in order to support SGI Ultraviolet systems.
437           If you don't have one of these, you should say N here.
438 
439 # Following is an alphabetically sorted list of 32 bit extended platforms
440 # Please maintain the alphabetic order if and when there are additions
441 
442 config X86_GOLDFISH
443        bool "Goldfish (Virtual Platform)"
444        depends on X86_EXTENDED_PLATFORM
445        ---help---
446          Enable support for the Goldfish virtual platform used primarily
447          for Android development. Unless you are building for the Android
448          Goldfish emulator say N here.
449 
450 config X86_INTEL_CE
451         bool "CE4100 TV platform"
452         depends on PCI
453         depends on PCI_GODIRECT
454         depends on X86_IO_APIC
455         depends on X86_32
456         depends on X86_EXTENDED_PLATFORM
457         select X86_REBOOTFIXUPS
458         select OF
459         select OF_EARLY_FLATTREE
460         select IRQ_DOMAIN
461         ---help---
462           Select for the Intel CE media processor (CE4100) SOC.
463           This option compiles in support for the CE4100 SOC for settop
464           boxes and media devices.
465 
466 config X86_INTEL_MID
467         bool "Intel MID platform support"
468         depends on X86_32
469         depends on X86_EXTENDED_PLATFORM
470         depends on X86_PLATFORM_DEVICES
471         depends on PCI
472         depends on PCI_GOANY
473         depends on X86_IO_APIC
474         select SFI
475         select I2C
476         select DW_APB_TIMER
477         select APB_TIMER
478         select INTEL_SCU_IPC
479         select MFD_INTEL_MSIC
480         ---help---
481           Select to build a kernel capable of supporting Intel MID (Mobile
482           Internet Device) platform systems which do not have the PCI legacy
483           interfaces. If you are building for a PC class system say N here.
484 
485           Intel MID platforms are based on an Intel processor and chipset which
486           consume less power than most of the x86 derivatives.
487 
488 config X86_INTEL_LPSS
489         bool "Intel Low Power Subsystem Support"
490         depends on ACPI
491         select COMMON_CLK
492         select PINCTRL
493         ---help---
494           Select to build support for Intel Low Power Subsystem such as
495           found on Intel Lynxpoint PCH. Selecting this option enables
496           things like clock tree (common clock framework) and pincontrol
497           which are needed by the LPSS peripheral drivers.
498 
499 config IOSF_MBI
500         tristate "Intel SoC IOSF Sideband support for SoC platforms"
501         depends on PCI
502         ---help---
503           This option enables sideband register access support for Intel SoC
504           platforms. On these platforms the IOSF sideband is used in lieu of
505           MSR's for some register accesses, mostly but not limited to thermal
506           and power. Drivers may query the availability of this device to
507           determine if they need the sideband in order to work on these
508           platforms. The sideband is available on the following SoC products.
509           This list is not meant to be exclusive.
510            - BayTrail
511            - Braswell
512            - Quark
513 
514           You should say Y if you are running a kernel on one of these SoC's.
515 
516 config IOSF_MBI_DEBUG
517         bool "Enable IOSF sideband access through debugfs"
518         depends on IOSF_MBI && DEBUG_FS
519         ---help---
520           Select this option to expose the IOSF sideband access registers (MCR,
521           MDR, MCRX) through debugfs to write and read register information from
522           different units on the SoC. This is most useful for obtaining device
523           state information for debug and analysis. As this is a general access
524           mechanism, users of this option would have specific knowledge of the
525           device they want to access.
526 
527           If you don't require the option or are in doubt, say N.
528 
529 config X86_RDC321X
530         bool "RDC R-321x SoC"
531         depends on X86_32
532         depends on X86_EXTENDED_PLATFORM
533         select M486
534         select X86_REBOOTFIXUPS
535         ---help---
536           This option is needed for RDC R-321x system-on-chip, also known
537           as R-8610-(G).
538           If you don't have one of these chips, you should say N here.
539 
540 config X86_32_NON_STANDARD
541         bool "Support non-standard 32-bit SMP architectures"
542         depends on X86_32 && SMP
543         depends on X86_EXTENDED_PLATFORM
544         ---help---
545           This option compiles in the bigsmp and STA2X11 default
546           subarchitectures.  It is intended for a generic binary
547           kernel. If you select them all, kernel will probe it one by
548           one and will fallback to default.
549 
550 # Alphabetically sorted list of Non standard 32 bit platforms
551 
552 config X86_SUPPORTS_MEMORY_FAILURE
553         def_bool y
554         # MCE code calls memory_failure():
555         depends on X86_MCE
556         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
557         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
558         depends on X86_64 || !SPARSEMEM
559         select ARCH_SUPPORTS_MEMORY_FAILURE
560 
561 config STA2X11
562         bool "STA2X11 Companion Chip Support"
563         depends on X86_32_NON_STANDARD && PCI
564         select X86_DEV_DMA_OPS
565         select X86_DMA_REMAP
566         select SWIOTLB
567         select MFD_STA2X11
568         select ARCH_REQUIRE_GPIOLIB
569         default n
570         ---help---
571           This adds support for boards based on the STA2X11 IO-Hub,
572           a.k.a. "ConneXt". The chip is used in place of the standard
573           PC chipset, so all "standard" peripherals are missing. If this
574           option is selected the kernel will still be able to boot on
575           standard PC machines.
576 
577 config X86_32_IRIS
578         tristate "Eurobraille/Iris poweroff module"
579         depends on X86_32
580         ---help---
581           The Iris machines from EuroBraille do not have APM or ACPI support
582           to shut themselves down properly.  A special I/O sequence is
583           needed to do so, which is what this module does at
584           kernel shutdown.
585 
586           This is only for Iris machines from EuroBraille.
587 
588           If unused, say N.
589 
590 config SCHED_OMIT_FRAME_POINTER
591         def_bool y
592         prompt "Single-depth WCHAN output"
593         depends on X86
594         ---help---
595           Calculate simpler /proc/<PID>/wchan values. If this option
596           is disabled then wchan values will recurse back to the
597           caller function. This provides more accurate wchan values,
598           at the expense of slightly more scheduling overhead.
599 
600           If in doubt, say "Y".
601 
602 menuconfig HYPERVISOR_GUEST
603         bool "Linux guest support"
604         ---help---
605           Say Y here to enable options for running Linux under various hyper-
606           visors. This option enables basic hypervisor detection and platform
607           setup.
608 
609           If you say N, all options in this submenu will be skipped and
610           disabled, and Linux guest support won't be built in.
611 
612 if HYPERVISOR_GUEST
613 
614 config PARAVIRT
615         bool "Enable paravirtualization code"
616         ---help---
617           This changes the kernel so it can modify itself when it is run
618           under a hypervisor, potentially improving performance significantly
619           over full virtualization.  However, when run without a hypervisor
620           the kernel is theoretically slower and slightly larger.
621 
622 config PARAVIRT_DEBUG
623         bool "paravirt-ops debugging"
624         depends on PARAVIRT && DEBUG_KERNEL
625         ---help---
626           Enable to debug paravirt_ops internals.  Specifically, BUG if
627           a paravirt_op is missing when it is called.
628 
629 config PARAVIRT_SPINLOCKS
630         bool "Paravirtualization layer for spinlocks"
631         depends on PARAVIRT && SMP
632         select UNINLINE_SPIN_UNLOCK
633         ---help---
634           Paravirtualized spinlocks allow a pvops backend to replace the
635           spinlock implementation with something virtualization-friendly
636           (for example, block the virtual CPU rather than spinning).
637 
638           It has a minimal impact on native kernels and gives a nice performance
639           benefit on paravirtualized KVM / Xen kernels.
640 
641           If you are unsure how to answer this question, answer Y.
642 
643 source "arch/x86/xen/Kconfig"
644 
645 config KVM_GUEST
646         bool "KVM Guest support (including kvmclock)"
647         depends on PARAVIRT
648         select PARAVIRT_CLOCK
649         default y
650         ---help---
651           This option enables various optimizations for running under the KVM
652           hypervisor. It includes a paravirtualized clock, so that instead
653           of relying on a PIT (or probably other) emulation by the
654           underlying device model, the host provides the guest with
655           timing infrastructure such as time of day, and system time
656 
657 config KVM_DEBUG_FS
658         bool "Enable debug information for KVM Guests in debugfs"
659         depends on KVM_GUEST && DEBUG_FS
660         default n
661         ---help---
662           This option enables collection of various statistics for KVM guest.
663           Statistics are displayed in debugfs filesystem. Enabling this option
664           may incur significant overhead.
665 
666 source "arch/x86/lguest/Kconfig"
667 
668 config PARAVIRT_TIME_ACCOUNTING
669         bool "Paravirtual steal time accounting"
670         depends on PARAVIRT
671         default n
672         ---help---
673           Select this option to enable fine granularity task steal time
674           accounting. Time spent executing other tasks in parallel with
675           the current vCPU is discounted from the vCPU power. To account for
676           that, there can be a small performance impact.
677 
678           If in doubt, say N here.
679 
680 config PARAVIRT_CLOCK
681         bool
682 
683 endif #HYPERVISOR_GUEST
684 
685 config NO_BOOTMEM
686         def_bool y
687 
688 config MEMTEST
689         bool "Memtest"
690         ---help---
691           This option adds a kernel parameter 'memtest', which allows memtest
692           to be set.
693                 memtest=0, mean disabled; -- default
694                 memtest=1, mean do 1 test pattern;
695                 ...
696                 memtest=4, mean do 4 test patterns.
697           If you are unsure how to answer this question, answer N.
698 
699 source "arch/x86/Kconfig.cpu"
700 
701 config HPET_TIMER
702         def_bool X86_64
703         prompt "HPET Timer Support" if X86_32
704         ---help---
705           Use the IA-PC HPET (High Precision Event Timer) to manage
706           time in preference to the PIT and RTC, if a HPET is
707           present.
708           HPET is the next generation timer replacing legacy 8254s.
709           The HPET provides a stable time base on SMP
710           systems, unlike the TSC, but it is more expensive to access,
711           as it is off-chip.  You can find the HPET spec at
712           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
713 
714           You can safely choose Y here.  However, HPET will only be
715           activated if the platform and the BIOS support this feature.
716           Otherwise the 8254 will be used for timing services.
717 
718           Choose N to continue using the legacy 8254 timer.
719 
720 config HPET_EMULATE_RTC
721         def_bool y
722         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
723 
724 config APB_TIMER
725        def_bool y if X86_INTEL_MID
726        prompt "Intel MID APB Timer Support" if X86_INTEL_MID
727        select DW_APB_TIMER
728        depends on X86_INTEL_MID && SFI
729        help
730          APB timer is the replacement for 8254, HPET on X86 MID platforms.
731          The APBT provides a stable time base on SMP
732          systems, unlike the TSC, but it is more expensive to access,
733          as it is off-chip. APB timers are always running regardless of CPU
734          C states, they are used as per CPU clockevent device when possible.
735 
736 # Mark as expert because too many people got it wrong.
737 # The code disables itself when not needed.
738 config DMI
739         default y
740         select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
741         bool "Enable DMI scanning" if EXPERT
742         ---help---
743           Enabled scanning of DMI to identify machine quirks. Say Y
744           here unless you have verified that your setup is not
745           affected by entries in the DMI blacklist. Required by PNP
746           BIOS code.
747 
748 config GART_IOMMU
749         bool "Old AMD GART IOMMU support"
750         select SWIOTLB
751         depends on X86_64 && PCI && AMD_NB
752         ---help---
753           Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
754           GART based hardware IOMMUs.
755 
756           The GART supports full DMA access for devices with 32-bit access
757           limitations, on systems with more than 3 GB. This is usually needed
758           for USB, sound, many IDE/SATA chipsets and some other devices.
759 
760           Newer systems typically have a modern AMD IOMMU, supported via
761           the CONFIG_AMD_IOMMU=y config option.
762 
763           In normal configurations this driver is only active when needed:
764           there's more than 3 GB of memory and the system contains a
765           32-bit limited device.
766 
767           If unsure, say Y.
768 
769 config CALGARY_IOMMU
770         bool "IBM Calgary IOMMU support"
771         select SWIOTLB
772         depends on X86_64 && PCI
773         ---help---
774           Support for hardware IOMMUs in IBM's xSeries x366 and x460
775           systems. Needed to run systems with more than 3GB of memory
776           properly with 32-bit PCI devices that do not support DAC
777           (Double Address Cycle). Calgary also supports bus level
778           isolation, where all DMAs pass through the IOMMU.  This
779           prevents them from going anywhere except their intended
780           destination. This catches hard-to-find kernel bugs and
781           mis-behaving drivers and devices that do not use the DMA-API
782           properly to set up their DMA buffers.  The IOMMU can be
783           turned off at boot time with the iommu=off parameter.
784           Normally the kernel will make the right choice by itself.
785           If unsure, say Y.
786 
787 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
788         def_bool y
789         prompt "Should Calgary be enabled by default?"
790         depends on CALGARY_IOMMU
791         ---help---
792           Should Calgary be enabled by default? if you choose 'y', Calgary
793           will be used (if it exists). If you choose 'n', Calgary will not be
794           used even if it exists. If you choose 'n' and would like to use
795           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
796           If unsure, say Y.
797 
798 # need this always selected by IOMMU for the VIA workaround
799 config SWIOTLB
800         def_bool y if X86_64
801         ---help---
802           Support for software bounce buffers used on x86-64 systems
803           which don't have a hardware IOMMU. Using this PCI devices
804           which can only access 32-bits of memory can be used on systems
805           with more than 3 GB of memory.
806           If unsure, say Y.
807 
808 config IOMMU_HELPER
809         def_bool y
810         depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
811 
812 config MAXSMP
813         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
814         depends on X86_64 && SMP && DEBUG_KERNEL
815         select CPUMASK_OFFSTACK
816         ---help---
817           Enable maximum number of CPUS and NUMA Nodes for this architecture.
818           If unsure, say N.
819 
820 config NR_CPUS
821         int "Maximum number of CPUs" if SMP && !MAXSMP
822         range 2 8 if SMP && X86_32 && !X86_BIGSMP
823         range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
824         range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
825         default "1" if !SMP
826         default "8192" if MAXSMP
827         default "32" if SMP && X86_BIGSMP
828         default "8" if SMP
829         ---help---
830           This allows you to specify the maximum number of CPUs which this
831           kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
832           supported value is 4096, otherwise the maximum value is 512.  The
833           minimum value which makes sense is 2.
834 
835           This is purely to save memory - each supported CPU adds
836           approximately eight kilobytes to the kernel image.
837 
838 config SCHED_SMT
839         bool "SMT (Hyperthreading) scheduler support"
840         depends on X86_HT
841         ---help---
842           SMT scheduler support improves the CPU scheduler's decision making
843           when dealing with Intel Pentium 4 chips with HyperThreading at a
844           cost of slightly increased overhead in some places. If unsure say
845           N here.
846 
847 config SCHED_MC
848         def_bool y
849         prompt "Multi-core scheduler support"
850         depends on X86_HT
851         ---help---
852           Multi-core scheduler support improves the CPU scheduler's decision
853           making when dealing with multi-core CPU chips at a cost of slightly
854           increased overhead in some places. If unsure say N here.
855 
856 source "kernel/Kconfig.preempt"
857 
858 config X86_UP_APIC
859         bool "Local APIC support on uniprocessors"
860         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
861         ---help---
862           A local APIC (Advanced Programmable Interrupt Controller) is an
863           integrated interrupt controller in the CPU. If you have a single-CPU
864           system which has a processor with a local APIC, you can say Y here to
865           enable and use it. If you say Y here even though your machine doesn't
866           have a local APIC, then the kernel will still run with no slowdown at
867           all. The local APIC supports CPU-generated self-interrupts (timer,
868           performance counters), and the NMI watchdog which detects hard
869           lockups.
870 
871 config X86_UP_APIC_MSI
872         def_bool y
873         select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
874 
875 config X86_UP_IOAPIC
876         bool "IO-APIC support on uniprocessors"
877         depends on X86_UP_APIC
878         ---help---
879           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
880           SMP-capable replacement for PC-style interrupt controllers. Most
881           SMP systems and many recent uniprocessor systems have one.
882 
883           If you have a single-CPU system with an IO-APIC, you can say Y here
884           to use it. If you say Y here even though your machine doesn't have
885           an IO-APIC, then the kernel will still run with no slowdown at all.
886 
887 config X86_LOCAL_APIC
888         def_bool y
889         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
890         select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
891 
892 config X86_IO_APIC
893         def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
894         depends on X86_LOCAL_APIC
895         select IRQ_DOMAIN
896 
897 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
898         bool "Reroute for broken boot IRQs"
899         depends on X86_IO_APIC
900         ---help---
901           This option enables a workaround that fixes a source of
902           spurious interrupts. This is recommended when threaded
903           interrupt handling is used on systems where the generation of
904           superfluous "boot interrupts" cannot be disabled.
905 
906           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
907           entry in the chipset's IO-APIC is masked (as, e.g. the RT
908           kernel does during interrupt handling). On chipsets where this
909           boot IRQ generation cannot be disabled, this workaround keeps
910           the original IRQ line masked so that only the equivalent "boot
911           IRQ" is delivered to the CPUs. The workaround also tells the
912           kernel to set up the IRQ handler on the boot IRQ line. In this
913           way only one interrupt is delivered to the kernel. Otherwise
914           the spurious second interrupt may cause the kernel to bring
915           down (vital) interrupt lines.
916 
917           Only affects "broken" chipsets. Interrupt sharing may be
918           increased on these systems.
919 
920 config X86_MCE
921         bool "Machine Check / overheating reporting"
922         default y
923         ---help---
924           Machine Check support allows the processor to notify the
925           kernel if it detects a problem (e.g. overheating, data corruption).
926           The action the kernel takes depends on the severity of the problem,
927           ranging from warning messages to halting the machine.
928 
929 config X86_MCE_INTEL
930         def_bool y
931         prompt "Intel MCE features"
932         depends on X86_MCE && X86_LOCAL_APIC
933         ---help---
934            Additional support for intel specific MCE features such as
935            the thermal monitor.
936 
937 config X86_MCE_AMD
938         def_bool y
939         prompt "AMD MCE features"
940         depends on X86_MCE && X86_LOCAL_APIC
941         ---help---
942            Additional support for AMD specific MCE features such as
943            the DRAM Error Threshold.
944 
945 config X86_ANCIENT_MCE
946         bool "Support for old Pentium 5 / WinChip machine checks"
947         depends on X86_32 && X86_MCE
948         ---help---
949           Include support for machine check handling on old Pentium 5 or WinChip
950           systems. These typically need to be enabled explicitly on the command
951           line.
952 
953 config X86_MCE_THRESHOLD
954         depends on X86_MCE_AMD || X86_MCE_INTEL
955         def_bool y
956 
957 config X86_MCE_INJECT
958         depends on X86_MCE
959         tristate "Machine check injector support"
960         ---help---
961           Provide support for injecting machine checks for testing purposes.
962           If you don't know what a machine check is and you don't do kernel
963           QA it is safe to say n.
964 
965 config X86_THERMAL_VECTOR
966         def_bool y
967         depends on X86_MCE_INTEL
968 
969 config VM86
970         bool "Enable VM86 support" if EXPERT
971         default y
972         depends on X86_32
973         ---help---
974           This option is required by programs like DOSEMU to run
975           16-bit real mode legacy code on x86 processors. It also may
976           be needed by software like XFree86 to initialize some video
977           cards via BIOS. Disabling this option saves about 6K.
978 
979 config X86_16BIT
980         bool "Enable support for 16-bit segments" if EXPERT
981         default y
982         ---help---
983           This option is required by programs like Wine to run 16-bit
984           protected mode legacy code on x86 processors.  Disabling
985           this option saves about 300 bytes on i386, or around 6K text
986           plus 16K runtime memory on x86-64,
987 
988 config X86_ESPFIX32
989         def_bool y
990         depends on X86_16BIT && X86_32
991 
992 config X86_ESPFIX64
993         def_bool y
994         depends on X86_16BIT && X86_64
995 
996 config X86_VSYSCALL_EMULATION
997        bool "Enable vsyscall emulation" if EXPERT
998        default y
999        depends on X86_64
1000        ---help---
1001          This enables emulation of the legacy vsyscall page.  Disabling
1002          it is roughly equivalent to booting with vsyscall=none, except
1003          that it will also disable the helpful warning if a program
1004          tries to use a vsyscall.  With this option set to N, offending
1005          programs will just segfault, citing addresses of the form
1006          0xffffffffff600?00.
1007 
1008          This option is required by many programs built before 2013, and
1009          care should be used even with newer programs if set to N.
1010 
1011          Disabling this option saves about 7K of kernel size and
1012          possibly 4K of additional runtime pagetable memory.
1013 
1014 config TOSHIBA
1015         tristate "Toshiba Laptop support"
1016         depends on X86_32
1017         ---help---
1018           This adds a driver to safely access the System Management Mode of
1019           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1020           not work on models with a Phoenix BIOS. The System Management Mode
1021           is used to set the BIOS and power saving options on Toshiba portables.
1022 
1023           For information on utilities to make use of this driver see the
1024           Toshiba Linux utilities web site at:
1025           <http://www.buzzard.org.uk/toshiba/>.
1026 
1027           Say Y if you intend to run this kernel on a Toshiba portable.
1028           Say N otherwise.
1029 
1030 config I8K
1031         tristate "Dell laptop support"
1032         select HWMON
1033         ---help---
1034           This adds a driver to safely access the System Management Mode
1035           of the CPU on the Dell Inspiron 8000. The System Management Mode
1036           is used to read cpu temperature and cooling fan status and to
1037           control the fans on the I8K portables.
1038 
1039           This driver has been tested only on the Inspiron 8000 but it may
1040           also work with other Dell laptops. You can force loading on other
1041           models by passing the parameter `force=1' to the module. Use at
1042           your own risk.
1043 
1044           For information on utilities to make use of this driver see the
1045           I8K Linux utilities web site at:
1046           <http://people.debian.org/~dz/i8k/>
1047 
1048           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1049           Say N otherwise.
1050 
1051 config X86_REBOOTFIXUPS
1052         bool "Enable X86 board specific fixups for reboot"
1053         depends on X86_32
1054         ---help---
1055           This enables chipset and/or board specific fixups to be done
1056           in order to get reboot to work correctly. This is only needed on
1057           some combinations of hardware and BIOS. The symptom, for which
1058           this config is intended, is when reboot ends with a stalled/hung
1059           system.
1060 
1061           Currently, the only fixup is for the Geode machines using
1062           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1063 
1064           Say Y if you want to enable the fixup. Currently, it's safe to
1065           enable this option even if you don't need it.
1066           Say N otherwise.
1067 
1068 config MICROCODE
1069         tristate "CPU microcode loading support"
1070         depends on CPU_SUP_AMD || CPU_SUP_INTEL
1071         select FW_LOADER
1072         ---help---
1073 
1074           If you say Y here, you will be able to update the microcode on
1075           certain Intel and AMD processors. The Intel support is for the
1076           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1077           Xeon etc. The AMD support is for families 0x10 and later. You will
1078           obviously need the actual microcode binary data itself which is not
1079           shipped with the Linux kernel.
1080 
1081           This option selects the general module only, you need to select
1082           at least one vendor specific module as well.
1083 
1084           To compile this driver as a module, choose M here: the module
1085           will be called microcode.
1086 
1087 config MICROCODE_INTEL
1088         bool "Intel microcode loading support"
1089         depends on MICROCODE
1090         default MICROCODE
1091         select FW_LOADER
1092         ---help---
1093           This options enables microcode patch loading support for Intel
1094           processors.
1095 
1096           For the current Intel microcode data package go to
1097           <https://downloadcenter.intel.com> and search for
1098           'Linux Processor Microcode Data File'.
1099 
1100 config MICROCODE_AMD
1101         bool "AMD microcode loading support"
1102         depends on MICROCODE
1103         select FW_LOADER
1104         ---help---
1105           If you select this option, microcode patch loading support for AMD
1106           processors will be enabled.
1107 
1108 config MICROCODE_OLD_INTERFACE
1109         def_bool y
1110         depends on MICROCODE
1111 
1112 config MICROCODE_INTEL_EARLY
1113         def_bool n
1114 
1115 config MICROCODE_AMD_EARLY
1116         def_bool n
1117 
1118 config MICROCODE_EARLY
1119         bool "Early load microcode"
1120         depends on MICROCODE=y && BLK_DEV_INITRD
1121         select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1122         select MICROCODE_AMD_EARLY if MICROCODE_AMD
1123         default y
1124         help
1125           This option provides functionality to read additional microcode data
1126           at the beginning of initrd image. The data tells kernel to load
1127           microcode to CPU's as early as possible. No functional change if no
1128           microcode data is glued to the initrd, therefore it's safe to say Y.
1129 
1130 config X86_MSR
1131         tristate "/dev/cpu/*/msr - Model-specific register support"
1132         ---help---
1133           This device gives privileged processes access to the x86
1134           Model-Specific Registers (MSRs).  It is a character device with
1135           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1136           MSR accesses are directed to a specific CPU on multi-processor
1137           systems.
1138 
1139 config X86_CPUID
1140         tristate "/dev/cpu/*/cpuid - CPU information support"
1141         ---help---
1142           This device gives processes access to the x86 CPUID instruction to
1143           be executed on a specific processor.  It is a character device
1144           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1145           /dev/cpu/31/cpuid.
1146 
1147 choice
1148         prompt "High Memory Support"
1149         default HIGHMEM4G
1150         depends on X86_32
1151 
1152 config NOHIGHMEM
1153         bool "off"
1154         ---help---
1155           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1156           However, the address space of 32-bit x86 processors is only 4
1157           Gigabytes large. That means that, if you have a large amount of
1158           physical memory, not all of it can be "permanently mapped" by the
1159           kernel. The physical memory that's not permanently mapped is called
1160           "high memory".
1161 
1162           If you are compiling a kernel which will never run on a machine with
1163           more than 1 Gigabyte total physical RAM, answer "off" here (default
1164           choice and suitable for most users). This will result in a "3GB/1GB"
1165           split: 3GB are mapped so that each process sees a 3GB virtual memory
1166           space and the remaining part of the 4GB virtual memory space is used
1167           by the kernel to permanently map as much physical memory as
1168           possible.
1169 
1170           If the machine has between 1 and 4 Gigabytes physical RAM, then
1171           answer "4GB" here.
1172 
1173           If more than 4 Gigabytes is used then answer "64GB" here. This
1174           selection turns Intel PAE (Physical Address Extension) mode on.
1175           PAE implements 3-level paging on IA32 processors. PAE is fully
1176           supported by Linux, PAE mode is implemented on all recent Intel
1177           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1178           then the kernel will not boot on CPUs that don't support PAE!
1179 
1180           The actual amount of total physical memory will either be
1181           auto detected or can be forced by using a kernel command line option
1182           such as "mem=256M". (Try "man bootparam" or see the documentation of
1183           your boot loader (lilo or loadlin) about how to pass options to the
1184           kernel at boot time.)
1185 
1186           If unsure, say "off".
1187 
1188 config HIGHMEM4G
1189         bool "4GB"
1190         ---help---
1191           Select this if you have a 32-bit processor and between 1 and 4
1192           gigabytes of physical RAM.
1193 
1194 config HIGHMEM64G
1195         bool "64GB"
1196         depends on !M486
1197         select X86_PAE
1198         ---help---
1199           Select this if you have a 32-bit processor and more than 4
1200           gigabytes of physical RAM.
1201 
1202 endchoice
1203 
1204 choice
1205         prompt "Memory split" if EXPERT
1206         default VMSPLIT_3G
1207         depends on X86_32
1208         ---help---
1209           Select the desired split between kernel and user memory.
1210 
1211           If the address range available to the kernel is less than the
1212           physical memory installed, the remaining memory will be available
1213           as "high memory". Accessing high memory is a little more costly
1214           than low memory, as it needs to be mapped into the kernel first.
1215           Note that increasing the kernel address space limits the range
1216           available to user programs, making the address space there
1217           tighter.  Selecting anything other than the default 3G/1G split
1218           will also likely make your kernel incompatible with binary-only
1219           kernel modules.
1220 
1221           If you are not absolutely sure what you are doing, leave this
1222           option alone!
1223 
1224         config VMSPLIT_3G
1225                 bool "3G/1G user/kernel split"
1226         config VMSPLIT_3G_OPT
1227                 depends on !X86_PAE
1228                 bool "3G/1G user/kernel split (for full 1G low memory)"
1229         config VMSPLIT_2G
1230                 bool "2G/2G user/kernel split"
1231         config VMSPLIT_2G_OPT
1232                 depends on !X86_PAE
1233                 bool "2G/2G user/kernel split (for full 2G low memory)"
1234         config VMSPLIT_1G
1235                 bool "1G/3G user/kernel split"
1236 endchoice
1237 
1238 config PAGE_OFFSET
1239         hex
1240         default 0xB0000000 if VMSPLIT_3G_OPT
1241         default 0x80000000 if VMSPLIT_2G
1242         default 0x78000000 if VMSPLIT_2G_OPT
1243         default 0x40000000 if VMSPLIT_1G
1244         default 0xC0000000
1245         depends on X86_32
1246 
1247 config HIGHMEM
1248         def_bool y
1249         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1250 
1251 config X86_PAE
1252         bool "PAE (Physical Address Extension) Support"
1253         depends on X86_32 && !HIGHMEM4G
1254         ---help---
1255           PAE is required for NX support, and furthermore enables
1256           larger swapspace support for non-overcommit purposes. It
1257           has the cost of more pagetable lookup overhead, and also
1258           consumes more pagetable space per process.
1259 
1260 config ARCH_PHYS_ADDR_T_64BIT
1261         def_bool y
1262         depends on X86_64 || X86_PAE
1263 
1264 config ARCH_DMA_ADDR_T_64BIT
1265         def_bool y
1266         depends on X86_64 || HIGHMEM64G
1267 
1268 config DIRECT_GBPAGES
1269         bool "Enable 1GB pages for kernel pagetables" if EXPERT
1270         default y
1271         depends on X86_64
1272         ---help---
1273           Allow the kernel linear mapping to use 1GB pages on CPUs that
1274           support it. This can improve the kernel's performance a tiny bit by
1275           reducing TLB pressure. If in doubt, say "Y".
1276 
1277 # Common NUMA Features
1278 config NUMA
1279         bool "Numa Memory Allocation and Scheduler Support"
1280         depends on SMP
1281         depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1282         default y if X86_BIGSMP
1283         ---help---
1284           Enable NUMA (Non Uniform Memory Access) support.
1285 
1286           The kernel will try to allocate memory used by a CPU on the
1287           local memory controller of the CPU and add some more
1288           NUMA awareness to the kernel.
1289 
1290           For 64-bit this is recommended if the system is Intel Core i7
1291           (or later), AMD Opteron, or EM64T NUMA.
1292 
1293           For 32-bit this is only needed if you boot a 32-bit
1294           kernel on a 64-bit NUMA platform.
1295 
1296           Otherwise, you should say N.
1297 
1298 config AMD_NUMA
1299         def_bool y
1300         prompt "Old style AMD Opteron NUMA detection"
1301         depends on X86_64 && NUMA && PCI
1302         ---help---
1303           Enable AMD NUMA node topology detection.  You should say Y here if
1304           you have a multi processor AMD system. This uses an old method to
1305           read the NUMA configuration directly from the builtin Northbridge
1306           of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1307           which also takes priority if both are compiled in.
1308 
1309 config X86_64_ACPI_NUMA
1310         def_bool y
1311         prompt "ACPI NUMA detection"
1312         depends on X86_64 && NUMA && ACPI && PCI
1313         select ACPI_NUMA
1314         ---help---
1315           Enable ACPI SRAT based node topology detection.
1316 
1317 # Some NUMA nodes have memory ranges that span
1318 # other nodes.  Even though a pfn is valid and
1319 # between a node's start and end pfns, it may not
1320 # reside on that node.  See memmap_init_zone()
1321 # for details.
1322 config NODES_SPAN_OTHER_NODES
1323         def_bool y
1324         depends on X86_64_ACPI_NUMA
1325 
1326 config NUMA_EMU
1327         bool "NUMA emulation"
1328         depends on NUMA
1329         ---help---
1330           Enable NUMA emulation. A flat machine will be split
1331           into virtual nodes when booted with "numa=fake=N", where N is the
1332           number of nodes. This is only useful for debugging.
1333 
1334 config NODES_SHIFT
1335         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1336         range 1 10
1337         default "10" if MAXSMP
1338         default "6" if X86_64
1339         default "3"
1340         depends on NEED_MULTIPLE_NODES
1341         ---help---
1342           Specify the maximum number of NUMA Nodes available on the target
1343           system.  Increases memory reserved to accommodate various tables.
1344 
1345 config ARCH_HAVE_MEMORY_PRESENT
1346         def_bool y
1347         depends on X86_32 && DISCONTIGMEM
1348 
1349 config NEED_NODE_MEMMAP_SIZE
1350         def_bool y
1351         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1352 
1353 config ARCH_FLATMEM_ENABLE
1354         def_bool y
1355         depends on X86_32 && !NUMA
1356 
1357 config ARCH_DISCONTIGMEM_ENABLE
1358         def_bool y
1359         depends on NUMA && X86_32
1360 
1361 config ARCH_DISCONTIGMEM_DEFAULT
1362         def_bool y
1363         depends on NUMA && X86_32
1364 
1365 config ARCH_SPARSEMEM_ENABLE
1366         def_bool y
1367         depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1368         select SPARSEMEM_STATIC if X86_32
1369         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1370 
1371 config ARCH_SPARSEMEM_DEFAULT
1372         def_bool y
1373         depends on X86_64
1374 
1375 config ARCH_SELECT_MEMORY_MODEL
1376         def_bool y
1377         depends on ARCH_SPARSEMEM_ENABLE
1378 
1379 config ARCH_MEMORY_PROBE
1380         bool "Enable sysfs memory/probe interface"
1381         depends on X86_64 && MEMORY_HOTPLUG
1382         help
1383           This option enables a sysfs memory/probe interface for testing.
1384           See Documentation/memory-hotplug.txt for more information.
1385           If you are unsure how to answer this question, answer N.
1386 
1387 config ARCH_PROC_KCORE_TEXT
1388         def_bool y
1389         depends on X86_64 && PROC_KCORE
1390 
1391 config ILLEGAL_POINTER_VALUE
1392        hex
1393        default 0 if X86_32
1394        default 0xdead000000000000 if X86_64
1395 
1396 source "mm/Kconfig"
1397 
1398 config HIGHPTE
1399         bool "Allocate 3rd-level pagetables from highmem"
1400         depends on HIGHMEM
1401         ---help---
1402           The VM uses one page table entry for each page of physical memory.
1403           For systems with a lot of RAM, this can be wasteful of precious
1404           low memory.  Setting this option will put user-space page table
1405           entries in high memory.
1406 
1407 config X86_CHECK_BIOS_CORRUPTION
1408         bool "Check for low memory corruption"
1409         ---help---
1410           Periodically check for memory corruption in low memory, which
1411           is suspected to be caused by BIOS.  Even when enabled in the
1412           configuration, it is disabled at runtime.  Enable it by
1413           setting "memory_corruption_check=1" on the kernel command
1414           line.  By default it scans the low 64k of memory every 60
1415           seconds; see the memory_corruption_check_size and
1416           memory_corruption_check_period parameters in
1417           Documentation/kernel-parameters.txt to adjust this.
1418 
1419           When enabled with the default parameters, this option has
1420           almost no overhead, as it reserves a relatively small amount
1421           of memory and scans it infrequently.  It both detects corruption
1422           and prevents it from affecting the running system.
1423 
1424           It is, however, intended as a diagnostic tool; if repeatable
1425           BIOS-originated corruption always affects the same memory,
1426           you can use memmap= to prevent the kernel from using that
1427           memory.
1428 
1429 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1430         bool "Set the default setting of memory_corruption_check"
1431         depends on X86_CHECK_BIOS_CORRUPTION
1432         default y
1433         ---help---
1434           Set whether the default state of memory_corruption_check is
1435           on or off.
1436 
1437 config X86_RESERVE_LOW
1438         int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1439         default 64
1440         range 4 640
1441         ---help---
1442           Specify the amount of low memory to reserve for the BIOS.
1443 
1444           The first page contains BIOS data structures that the kernel
1445           must not use, so that page must always be reserved.
1446 
1447           By default we reserve the first 64K of physical RAM, as a
1448           number of BIOSes are known to corrupt that memory range
1449           during events such as suspend/resume or monitor cable
1450           insertion, so it must not be used by the kernel.
1451 
1452           You can set this to 4 if you are absolutely sure that you
1453           trust the BIOS to get all its memory reservations and usages
1454           right.  If you know your BIOS have problems beyond the
1455           default 64K area, you can set this to 640 to avoid using the
1456           entire low memory range.
1457 
1458           If you have doubts about the BIOS (e.g. suspend/resume does
1459           not work or there's kernel crashes after certain hardware
1460           hotplug events) then you might want to enable
1461           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1462           typical corruption patterns.
1463 
1464           Leave this to the default value of 64 if you are unsure.
1465 
1466 config MATH_EMULATION
1467         bool
1468         prompt "Math emulation" if X86_32
1469         ---help---
1470           Linux can emulate a math coprocessor (used for floating point
1471           operations) if you don't have one. 486DX and Pentium processors have
1472           a math coprocessor built in, 486SX and 386 do not, unless you added
1473           a 487DX or 387, respectively. (The messages during boot time can
1474           give you some hints here ["man dmesg"].) Everyone needs either a
1475           coprocessor or this emulation.
1476 
1477           If you don't have a math coprocessor, you need to say Y here; if you
1478           say Y here even though you have a coprocessor, the coprocessor will
1479           be used nevertheless. (This behavior can be changed with the kernel
1480           command line option "no387", which comes handy if your coprocessor
1481           is broken. Try "man bootparam" or see the documentation of your boot
1482           loader (lilo or loadlin) about how to pass options to the kernel at
1483           boot time.) This means that it is a good idea to say Y here if you
1484           intend to use this kernel on different machines.
1485 
1486           More information about the internals of the Linux math coprocessor
1487           emulation can be found in <file:arch/x86/math-emu/README>.
1488 
1489           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1490           kernel, it won't hurt.
1491 
1492 config MTRR
1493         def_bool y
1494         prompt "MTRR (Memory Type Range Register) support" if EXPERT
1495         ---help---
1496           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1497           the Memory Type Range Registers (MTRRs) may be used to control
1498           processor access to memory ranges. This is most useful if you have
1499           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1500           allows bus write transfers to be combined into a larger transfer
1501           before bursting over the PCI/AGP bus. This can increase performance
1502           of image write operations 2.5 times or more. Saying Y here creates a
1503           /proc/mtrr file which may be used to manipulate your processor's
1504           MTRRs. Typically the X server should use this.
1505 
1506           This code has a reasonably generic interface so that similar
1507           control registers on other processors can be easily supported
1508           as well:
1509 
1510           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1511           Registers (ARRs) which provide a similar functionality to MTRRs. For
1512           these, the ARRs are used to emulate the MTRRs.
1513           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1514           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1515           write-combining. All of these processors are supported by this code
1516           and it makes sense to say Y here if you have one of them.
1517 
1518           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1519           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1520           can lead to all sorts of problems, so it's good to say Y here.
1521 
1522           You can safely say Y even if your machine doesn't have MTRRs, you'll
1523           just add about 9 KB to your kernel.
1524 
1525           See <file:Documentation/x86/mtrr.txt> for more information.
1526 
1527 config MTRR_SANITIZER
1528         def_bool y
1529         prompt "MTRR cleanup support"
1530         depends on MTRR
1531         ---help---
1532           Convert MTRR layout from continuous to discrete, so X drivers can
1533           add writeback entries.
1534 
1535           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1536           The largest mtrr entry size for a continuous block can be set with
1537           mtrr_chunk_size.
1538 
1539           If unsure, say Y.
1540 
1541 config MTRR_SANITIZER_ENABLE_DEFAULT
1542         int "MTRR cleanup enable value (0-1)"
1543         range 0 1
1544         default "0"
1545         depends on MTRR_SANITIZER
1546         ---help---
1547           Enable mtrr cleanup default value
1548 
1549 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1550         int "MTRR cleanup spare reg num (0-7)"
1551         range 0 7
1552         default "1"
1553         depends on MTRR_SANITIZER
1554         ---help---
1555           mtrr cleanup spare entries default, it can be changed via
1556           mtrr_spare_reg_nr=N on the kernel command line.
1557 
1558 config X86_PAT
1559         def_bool y
1560         prompt "x86 PAT support" if EXPERT
1561         depends on MTRR
1562         ---help---
1563           Use PAT attributes to setup page level cache control.
1564 
1565           PATs are the modern equivalents of MTRRs and are much more
1566           flexible than MTRRs.
1567 
1568           Say N here if you see bootup problems (boot crash, boot hang,
1569           spontaneous reboots) or a non-working video driver.
1570 
1571           If unsure, say Y.
1572 
1573 config ARCH_USES_PG_UNCACHED
1574         def_bool y
1575         depends on X86_PAT
1576 
1577 config ARCH_RANDOM
1578         def_bool y
1579         prompt "x86 architectural random number generator" if EXPERT
1580         ---help---
1581           Enable the x86 architectural RDRAND instruction
1582           (Intel Bull Mountain technology) to generate random numbers.
1583           If supported, this is a high bandwidth, cryptographically
1584           secure hardware random number generator.
1585 
1586 config X86_SMAP
1587         def_bool y
1588         prompt "Supervisor Mode Access Prevention" if EXPERT
1589         ---help---
1590           Supervisor Mode Access Prevention (SMAP) is a security
1591           feature in newer Intel processors.  There is a small
1592           performance cost if this enabled and turned on; there is
1593           also a small increase in the kernel size if this is enabled.
1594 
1595           If unsure, say Y.
1596 
1597 config X86_INTEL_MPX
1598         prompt "Intel MPX (Memory Protection Extensions)"
1599         def_bool n
1600         depends on CPU_SUP_INTEL
1601         ---help---
1602           MPX provides hardware features that can be used in
1603           conjunction with compiler-instrumented code to check
1604           memory references.  It is designed to detect buffer
1605           overflow or underflow bugs.
1606 
1607           This option enables running applications which are
1608           instrumented or otherwise use MPX.  It does not use MPX
1609           itself inside the kernel or to protect the kernel
1610           against bad memory references.
1611 
1612           Enabling this option will make the kernel larger:
1613           ~8k of kernel text and 36 bytes of data on a 64-bit
1614           defconfig.  It adds a long to the 'mm_struct' which
1615           will increase the kernel memory overhead of each
1616           process and adds some branches to paths used during
1617           exec() and munmap().
1618 
1619           For details, see Documentation/x86/intel_mpx.txt
1620 
1621           If unsure, say N.
1622 
1623 config EFI
1624         bool "EFI runtime service support"
1625         depends on ACPI
1626         select UCS2_STRING
1627         select EFI_RUNTIME_WRAPPERS
1628         ---help---
1629           This enables the kernel to use EFI runtime services that are
1630           available (such as the EFI variable services).
1631 
1632           This option is only useful on systems that have EFI firmware.
1633           In addition, you should use the latest ELILO loader available
1634           at <http://elilo.sourceforge.net> in order to take advantage
1635           of EFI runtime services. However, even with this option, the
1636           resultant kernel should continue to boot on existing non-EFI
1637           platforms.
1638 
1639 config EFI_STUB
1640        bool "EFI stub support"
1641        depends on EFI && !X86_USE_3DNOW
1642        select RELOCATABLE
1643        ---help---
1644           This kernel feature allows a bzImage to be loaded directly
1645           by EFI firmware without the use of a bootloader.
1646 
1647           See Documentation/efi-stub.txt for more information.
1648 
1649 config EFI_MIXED
1650         bool "EFI mixed-mode support"
1651         depends on EFI_STUB && X86_64
1652         ---help---
1653            Enabling this feature allows a 64-bit kernel to be booted
1654            on a 32-bit firmware, provided that your CPU supports 64-bit
1655            mode.
1656 
1657            Note that it is not possible to boot a mixed-mode enabled
1658            kernel via the EFI boot stub - a bootloader that supports
1659            the EFI handover protocol must be used.
1660 
1661            If unsure, say N.
1662 
1663 config SECCOMP
1664         def_bool y
1665         prompt "Enable seccomp to safely compute untrusted bytecode"
1666         ---help---
1667           This kernel feature is useful for number crunching applications
1668           that may need to compute untrusted bytecode during their
1669           execution. By using pipes or other transports made available to
1670           the process as file descriptors supporting the read/write
1671           syscalls, it's possible to isolate those applications in
1672           their own address space using seccomp. Once seccomp is
1673           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1674           and the task is only allowed to execute a few safe syscalls
1675           defined by each seccomp mode.
1676 
1677           If unsure, say Y. Only embedded should say N here.
1678 
1679 source kernel/Kconfig.hz
1680 
1681 config KEXEC
1682         bool "kexec system call"
1683         ---help---
1684           kexec is a system call that implements the ability to shutdown your
1685           current kernel, and to start another kernel.  It is like a reboot
1686           but it is independent of the system firmware.   And like a reboot
1687           you can start any kernel with it, not just Linux.
1688 
1689           The name comes from the similarity to the exec system call.
1690 
1691           It is an ongoing process to be certain the hardware in a machine
1692           is properly shutdown, so do not be surprised if this code does not
1693           initially work for you.  As of this writing the exact hardware
1694           interface is strongly in flux, so no good recommendation can be
1695           made.
1696 
1697 config KEXEC_FILE
1698         bool "kexec file based system call"
1699         select BUILD_BIN2C
1700         depends on KEXEC
1701         depends on X86_64
1702         depends on CRYPTO=y
1703         depends on CRYPTO_SHA256=y
1704         ---help---
1705           This is new version of kexec system call. This system call is
1706           file based and takes file descriptors as system call argument
1707           for kernel and initramfs as opposed to list of segments as
1708           accepted by previous system call.
1709 
1710 config KEXEC_VERIFY_SIG
1711         bool "Verify kernel signature during kexec_file_load() syscall"
1712         depends on KEXEC_FILE
1713         ---help---
1714           This option makes kernel signature verification mandatory for
1715           kexec_file_load() syscall. If kernel is signature can not be
1716           verified, kexec_file_load() will fail.
1717 
1718           This option enforces signature verification at generic level.
1719           One needs to enable signature verification for type of kernel
1720           image being loaded to make sure it works. For example, enable
1721           bzImage signature verification option to be able to load and
1722           verify signatures of bzImage. Otherwise kernel loading will fail.
1723 
1724 config KEXEC_BZIMAGE_VERIFY_SIG
1725         bool "Enable bzImage signature verification support"
1726         depends on KEXEC_VERIFY_SIG
1727         depends on SIGNED_PE_FILE_VERIFICATION
1728         select SYSTEM_TRUSTED_KEYRING
1729         ---help---
1730           Enable bzImage signature verification support.
1731 
1732 config CRASH_DUMP
1733         bool "kernel crash dumps"
1734         depends on X86_64 || (X86_32 && HIGHMEM)
1735         ---help---
1736           Generate crash dump after being started by kexec.
1737           This should be normally only set in special crash dump kernels
1738           which are loaded in the main kernel with kexec-tools into
1739           a specially reserved region and then later executed after
1740           a crash by kdump/kexec. The crash dump kernel must be compiled
1741           to a memory address not used by the main kernel or BIOS using
1742           PHYSICAL_START, or it must be built as a relocatable image
1743           (CONFIG_RELOCATABLE=y).
1744           For more details see Documentation/kdump/kdump.txt
1745 
1746 config KEXEC_JUMP
1747         bool "kexec jump"
1748         depends on KEXEC && HIBERNATION
1749         ---help---
1750           Jump between original kernel and kexeced kernel and invoke
1751           code in physical address mode via KEXEC
1752 
1753 config PHYSICAL_START
1754         hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1755         default "0x1000000"
1756         ---help---
1757           This gives the physical address where the kernel is loaded.
1758 
1759           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1760           bzImage will decompress itself to above physical address and
1761           run from there. Otherwise, bzImage will run from the address where
1762           it has been loaded by the boot loader and will ignore above physical
1763           address.
1764 
1765           In normal kdump cases one does not have to set/change this option
1766           as now bzImage can be compiled as a completely relocatable image
1767           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1768           address. This option is mainly useful for the folks who don't want
1769           to use a bzImage for capturing the crash dump and want to use a
1770           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1771           to be specifically compiled to run from a specific memory area
1772           (normally a reserved region) and this option comes handy.
1773 
1774           So if you are using bzImage for capturing the crash dump,
1775           leave the value here unchanged to 0x1000000 and set
1776           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1777           for capturing the crash dump change this value to start of
1778           the reserved region.  In other words, it can be set based on
1779           the "X" value as specified in the "crashkernel=YM@XM"
1780           command line boot parameter passed to the panic-ed
1781           kernel. Please take a look at Documentation/kdump/kdump.txt
1782           for more details about crash dumps.
1783 
1784           Usage of bzImage for capturing the crash dump is recommended as
1785           one does not have to build two kernels. Same kernel can be used
1786           as production kernel and capture kernel. Above option should have
1787           gone away after relocatable bzImage support is introduced. But it
1788           is present because there are users out there who continue to use
1789           vmlinux for dump capture. This option should go away down the
1790           line.
1791 
1792           Don't change this unless you know what you are doing.
1793 
1794 config RELOCATABLE
1795         bool "Build a relocatable kernel"
1796         default y
1797         ---help---
1798           This builds a kernel image that retains relocation information
1799           so it can be loaded someplace besides the default 1MB.
1800           The relocations tend to make the kernel binary about 10% larger,
1801           but are discarded at runtime.
1802 
1803           One use is for the kexec on panic case where the recovery kernel
1804           must live at a different physical address than the primary
1805           kernel.
1806 
1807           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1808           it has been loaded at and the compile time physical address
1809           (CONFIG_PHYSICAL_START) is used as the minimum location.
1810 
1811 config RANDOMIZE_BASE
1812         bool "Randomize the address of the kernel image"
1813         depends on RELOCATABLE
1814         default n
1815         ---help---
1816            Randomizes the physical and virtual address at which the
1817            kernel image is decompressed, as a security feature that
1818            deters exploit attempts relying on knowledge of the location
1819            of kernel internals.
1820 
1821            Entropy is generated using the RDRAND instruction if it is
1822            supported. If RDTSC is supported, it is used as well. If
1823            neither RDRAND nor RDTSC are supported, then randomness is
1824            read from the i8254 timer.
1825 
1826            The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1827            and aligned according to PHYSICAL_ALIGN. Since the kernel is
1828            built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1829            minimum of 2MiB, only 10 bits of entropy is theoretically
1830            possible. At best, due to page table layouts, 64-bit can use
1831            9 bits of entropy and 32-bit uses 8 bits.
1832 
1833            If unsure, say N.
1834 
1835 config RANDOMIZE_BASE_MAX_OFFSET
1836         hex "Maximum kASLR offset allowed" if EXPERT
1837         depends on RANDOMIZE_BASE
1838         range 0x0 0x20000000 if X86_32
1839         default "0x20000000" if X86_32
1840         range 0x0 0x40000000 if X86_64
1841         default "0x40000000" if X86_64
1842         ---help---
1843           The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1844           memory is used to determine the maximal offset in bytes that will
1845           be applied to the kernel when kernel Address Space Layout
1846           Randomization (kASLR) is active. This must be a multiple of
1847           PHYSICAL_ALIGN.
1848 
1849           On 32-bit this is limited to 512MiB by page table layouts. The
1850           default is 512MiB.
1851 
1852           On 64-bit this is limited by how the kernel fixmap page table is
1853           positioned, so this cannot be larger than 1GiB currently. Without
1854           RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1855           and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1856           modules area will shrink to compensate, up to the current maximum
1857           1GiB to 1GiB split. The default is 1GiB.
1858 
1859           If unsure, leave at the default value.
1860 
1861 # Relocation on x86 needs some additional build support
1862 config X86_NEED_RELOCS
1863         def_bool y
1864         depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1865 
1866 config PHYSICAL_ALIGN
1867         hex "Alignment value to which kernel should be aligned"
1868         default "0x200000"
1869         range 0x2000 0x1000000 if X86_32
1870         range 0x200000 0x1000000 if X86_64
1871         ---help---
1872           This value puts the alignment restrictions on physical address
1873           where kernel is loaded and run from. Kernel is compiled for an
1874           address which meets above alignment restriction.
1875 
1876           If bootloader loads the kernel at a non-aligned address and
1877           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1878           address aligned to above value and run from there.
1879 
1880           If bootloader loads the kernel at a non-aligned address and
1881           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1882           load address and decompress itself to the address it has been
1883           compiled for and run from there. The address for which kernel is
1884           compiled already meets above alignment restrictions. Hence the
1885           end result is that kernel runs from a physical address meeting
1886           above alignment restrictions.
1887 
1888           On 32-bit this value must be a multiple of 0x2000. On 64-bit
1889           this value must be a multiple of 0x200000.
1890 
1891           Don't change this unless you know what you are doing.
1892 
1893 config HOTPLUG_CPU
1894         bool "Support for hot-pluggable CPUs"
1895         depends on SMP
1896         ---help---
1897           Say Y here to allow turning CPUs off and on. CPUs can be
1898           controlled through /sys/devices/system/cpu.
1899           ( Note: power management support will enable this option
1900             automatically on SMP systems. )
1901           Say N if you want to disable CPU hotplug.
1902 
1903 config BOOTPARAM_HOTPLUG_CPU0
1904         bool "Set default setting of cpu0_hotpluggable"
1905         default n
1906         depends on HOTPLUG_CPU
1907         ---help---
1908           Set whether default state of cpu0_hotpluggable is on or off.
1909 
1910           Say Y here to enable CPU0 hotplug by default. If this switch
1911           is turned on, there is no need to give cpu0_hotplug kernel
1912           parameter and the CPU0 hotplug feature is enabled by default.
1913 
1914           Please note: there are two known CPU0 dependencies if you want
1915           to enable the CPU0 hotplug feature either by this switch or by
1916           cpu0_hotplug kernel parameter.
1917 
1918           First, resume from hibernate or suspend always starts from CPU0.
1919           So hibernate and suspend are prevented if CPU0 is offline.
1920 
1921           Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1922           offline if any interrupt can not migrate out of CPU0. There may
1923           be other CPU0 dependencies.
1924 
1925           Please make sure the dependencies are under your control before
1926           you enable this feature.
1927 
1928           Say N if you don't want to enable CPU0 hotplug feature by default.
1929           You still can enable the CPU0 hotplug feature at boot by kernel
1930           parameter cpu0_hotplug.
1931 
1932 config DEBUG_HOTPLUG_CPU0
1933         def_bool n
1934         prompt "Debug CPU0 hotplug"
1935         depends on HOTPLUG_CPU
1936         ---help---
1937           Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1938           soon as possible and boots up userspace with CPU0 offlined. User
1939           can online CPU0 back after boot time.
1940 
1941           To debug CPU0 hotplug, you need to enable CPU0 offline/online
1942           feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1943           compilation or giving cpu0_hotplug kernel parameter at boot.
1944 
1945           If unsure, say N.
1946 
1947 config COMPAT_VDSO
1948         def_bool n
1949         prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1950         depends on X86_32 || IA32_EMULATION
1951         ---help---
1952           Certain buggy versions of glibc will crash if they are
1953           presented with a 32-bit vDSO that is not mapped at the address
1954           indicated in its segment table.
1955 
1956           The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1957           and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1958           49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
1959           the only released version with the bug, but OpenSUSE 9
1960           contains a buggy "glibc 2.3.2".
1961 
1962           The symptom of the bug is that everything crashes on startup, saying:
1963           dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1964 
1965           Saying Y here changes the default value of the vdso32 boot
1966           option from 1 to 0, which turns off the 32-bit vDSO entirely.
1967           This works around the glibc bug but hurts performance.
1968 
1969           If unsure, say N: if you are compiling your own kernel, you
1970           are unlikely to be using a buggy version of glibc.
1971 
1972 config CMDLINE_BOOL
1973         bool "Built-in kernel command line"
1974         ---help---
1975           Allow for specifying boot arguments to the kernel at
1976           build time.  On some systems (e.g. embedded ones), it is
1977           necessary or convenient to provide some or all of the
1978           kernel boot arguments with the kernel itself (that is,
1979           to not rely on the boot loader to provide them.)
1980 
1981           To compile command line arguments into the kernel,
1982           set this option to 'Y', then fill in the
1983           the boot arguments in CONFIG_CMDLINE.
1984 
1985           Systems with fully functional boot loaders (i.e. non-embedded)
1986           should leave this option set to 'N'.
1987 
1988 config CMDLINE
1989         string "Built-in kernel command string"
1990         depends on CMDLINE_BOOL
1991         default ""
1992         ---help---
1993           Enter arguments here that should be compiled into the kernel
1994           image and used at boot time.  If the boot loader provides a
1995           command line at boot time, it is appended to this string to
1996           form the full kernel command line, when the system boots.
1997 
1998           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1999           change this behavior.
2000 
2001           In most cases, the command line (whether built-in or provided
2002           by the boot loader) should specify the device for the root
2003           file system.
2004 
2005 config CMDLINE_OVERRIDE
2006         bool "Built-in command line overrides boot loader arguments"
2007         depends on CMDLINE_BOOL
2008         ---help---
2009           Set this option to 'Y' to have the kernel ignore the boot loader
2010           command line, and use ONLY the built-in command line.
2011 
2012           This is used to work around broken boot loaders.  This should
2013           be set to 'N' under normal conditions.
2014 
2015 endmenu
2016 
2017 config ARCH_ENABLE_MEMORY_HOTPLUG
2018         def_bool y
2019         depends on X86_64 || (X86_32 && HIGHMEM)
2020 
2021 config ARCH_ENABLE_MEMORY_HOTREMOVE
2022         def_bool y
2023         depends on MEMORY_HOTPLUG
2024 
2025 config USE_PERCPU_NUMA_NODE_ID
2026         def_bool y
2027         depends on NUMA
2028 
2029 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2030         def_bool y
2031         depends on X86_64 || X86_PAE
2032 
2033 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2034         def_bool y
2035         depends on X86_64 && HUGETLB_PAGE && MIGRATION
2036 
2037 menu "Power management and ACPI options"
2038 
2039 config ARCH_HIBERNATION_HEADER
2040         def_bool y
2041         depends on X86_64 && HIBERNATION
2042 
2043 source "kernel/power/Kconfig"
2044 
2045 source "drivers/acpi/Kconfig"
2046 
2047 source "drivers/sfi/Kconfig"
2048 
2049 config X86_APM_BOOT
2050         def_bool y
2051         depends on APM
2052 
2053 menuconfig APM
2054         tristate "APM (Advanced Power Management) BIOS support"
2055         depends on X86_32 && PM_SLEEP
2056         ---help---
2057           APM is a BIOS specification for saving power using several different
2058           techniques. This is mostly useful for battery powered laptops with
2059           APM compliant BIOSes. If you say Y here, the system time will be
2060           reset after a RESUME operation, the /proc/apm device will provide
2061           battery status information, and user-space programs will receive
2062           notification of APM "events" (e.g. battery status change).
2063 
2064           If you select "Y" here, you can disable actual use of the APM
2065           BIOS by passing the "apm=off" option to the kernel at boot time.
2066 
2067           Note that the APM support is almost completely disabled for
2068           machines with more than one CPU.
2069 
2070           In order to use APM, you will need supporting software. For location
2071           and more information, read <file:Documentation/power/apm-acpi.txt>
2072           and the Battery Powered Linux mini-HOWTO, available from
2073           <http://www.tldp.org/docs.html#howto>.
2074 
2075           This driver does not spin down disk drives (see the hdparm(8)
2076           manpage ("man 8 hdparm") for that), and it doesn't turn off
2077           VESA-compliant "green" monitors.
2078 
2079           This driver does not support the TI 4000M TravelMate and the ACER
2080           486/DX4/75 because they don't have compliant BIOSes. Many "green"
2081           desktop machines also don't have compliant BIOSes, and this driver
2082           may cause those machines to panic during the boot phase.
2083 
2084           Generally, if you don't have a battery in your machine, there isn't
2085           much point in using this driver and you should say N. If you get
2086           random kernel OOPSes or reboots that don't seem to be related to
2087           anything, try disabling/enabling this option (or disabling/enabling
2088           APM in your BIOS).
2089 
2090           Some other things you should try when experiencing seemingly random,
2091           "weird" problems:
2092 
2093           1) make sure that you have enough swap space and that it is
2094           enabled.
2095           2) pass the "no-hlt" option to the kernel
2096           3) switch on floating point emulation in the kernel and pass
2097           the "no387" option to the kernel
2098           4) pass the "floppy=nodma" option to the kernel
2099           5) pass the "mem=4M" option to the kernel (thereby disabling
2100           all but the first 4 MB of RAM)
2101           6) make sure that the CPU is not over clocked.
2102           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2103           8) disable the cache from your BIOS settings
2104           9) install a fan for the video card or exchange video RAM
2105           10) install a better fan for the CPU
2106           11) exchange RAM chips
2107           12) exchange the motherboard.
2108 
2109           To compile this driver as a module, choose M here: the
2110           module will be called apm.
2111 
2112 if APM
2113 
2114 config APM_IGNORE_USER_SUSPEND
2115         bool "Ignore USER SUSPEND"
2116         ---help---
2117           This option will ignore USER SUSPEND requests. On machines with a
2118           compliant APM BIOS, you want to say N. However, on the NEC Versa M
2119           series notebooks, it is necessary to say Y because of a BIOS bug.
2120 
2121 config APM_DO_ENABLE
2122         bool "Enable PM at boot time"
2123         ---help---
2124           Enable APM features at boot time. From page 36 of the APM BIOS
2125           specification: "When disabled, the APM BIOS does not automatically
2126           power manage devices, enter the Standby State, enter the Suspend
2127           State, or take power saving steps in response to CPU Idle calls."
2128           This driver will make CPU Idle calls when Linux is idle (unless this
2129           feature is turned off -- see "Do CPU IDLE calls", below). This
2130           should always save battery power, but more complicated APM features
2131           will be dependent on your BIOS implementation. You may need to turn
2132           this option off if your computer hangs at boot time when using APM
2133           support, or if it beeps continuously instead of suspending. Turn
2134           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2135           T400CDT. This is off by default since most machines do fine without
2136           this feature.
2137 
2138 config APM_CPU_IDLE
2139         depends on CPU_IDLE
2140         bool "Make CPU Idle calls when idle"
2141         ---help---
2142           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2143           On some machines, this can activate improved power savings, such as
2144           a slowed CPU clock rate, when the machine is idle. These idle calls
2145           are made after the idle loop has run for some length of time (e.g.,
2146           333 mS). On some machines, this will cause a hang at boot time or
2147           whenever the CPU becomes idle. (On machines with more than one CPU,
2148           this option does nothing.)
2149 
2150 config APM_DISPLAY_BLANK
2151         bool "Enable console blanking using APM"
2152         ---help---
2153           Enable console blanking using the APM. Some laptops can use this to
2154           turn off the LCD backlight when the screen blanker of the Linux
2155           virtual console blanks the screen. Note that this is only used by
2156           the virtual console screen blanker, and won't turn off the backlight
2157           when using the X Window system. This also doesn't have anything to
2158           do with your VESA-compliant power-saving monitor. Further, this
2159           option doesn't work for all laptops -- it might not turn off your
2160           backlight at all, or it might print a lot of errors to the console,
2161           especially if you are using gpm.
2162 
2163 config APM_ALLOW_INTS
2164         bool "Allow interrupts during APM BIOS calls"
2165         ---help---
2166           Normally we disable external interrupts while we are making calls to
2167           the APM BIOS as a measure to lessen the effects of a badly behaving
2168           BIOS implementation.  The BIOS should reenable interrupts if it
2169           needs to.  Unfortunately, some BIOSes do not -- especially those in
2170           many of the newer IBM Thinkpads.  If you experience hangs when you
2171           suspend, try setting this to Y.  Otherwise, say N.
2172 
2173 endif # APM
2174 
2175 source "drivers/cpufreq/Kconfig"
2176 
2177 source "drivers/cpuidle/Kconfig"
2178 
2179 source "drivers/idle/Kconfig"
2180 
2181 endmenu
2182 
2183 
2184 menu "Bus options (PCI etc.)"
2185 
2186 config PCI
2187         bool "PCI support"
2188         default y
2189         ---help---
2190           Find out whether you have a PCI motherboard. PCI is the name of a
2191           bus system, i.e. the way the CPU talks to the other stuff inside
2192           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2193           VESA. If you have PCI, say Y, otherwise N.
2194 
2195 choice
2196         prompt "PCI access mode"
2197         depends on X86_32 && PCI
2198         default PCI_GOANY
2199         ---help---
2200           On PCI systems, the BIOS can be used to detect the PCI devices and
2201           determine their configuration. However, some old PCI motherboards
2202           have BIOS bugs and may crash if this is done. Also, some embedded
2203           PCI-based systems don't have any BIOS at all. Linux can also try to
2204           detect the PCI hardware directly without using the BIOS.
2205 
2206           With this option, you can specify how Linux should detect the
2207           PCI devices. If you choose "BIOS", the BIOS will be used,
2208           if you choose "Direct", the BIOS won't be used, and if you
2209           choose "MMConfig", then PCI Express MMCONFIG will be used.
2210           If you choose "Any", the kernel will try MMCONFIG, then the
2211           direct access method and falls back to the BIOS if that doesn't
2212           work. If unsure, go with the default, which is "Any".
2213 
2214 config PCI_GOBIOS
2215         bool "BIOS"
2216 
2217 config PCI_GOMMCONFIG
2218         bool "MMConfig"
2219 
2220 config PCI_GODIRECT
2221         bool "Direct"
2222 
2223 config PCI_GOOLPC
2224         bool "OLPC XO-1"
2225         depends on OLPC
2226 
2227 config PCI_GOANY
2228         bool "Any"
2229 
2230 endchoice
2231 
2232 config PCI_BIOS
2233         def_bool y
2234         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2235 
2236 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2237 config PCI_DIRECT
2238         def_bool y
2239         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2240 
2241 config PCI_MMCONFIG
2242         def_bool y
2243         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2244 
2245 config PCI_OLPC
2246         def_bool y
2247         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2248 
2249 config PCI_XEN
2250         def_bool y
2251         depends on PCI && XEN
2252         select SWIOTLB_XEN
2253 
2254 config PCI_DOMAINS
2255         def_bool y
2256         depends on PCI
2257 
2258 config PCI_MMCONFIG
2259         bool "Support mmconfig PCI config space access"
2260         depends on X86_64 && PCI && ACPI
2261 
2262 config PCI_CNB20LE_QUIRK
2263         bool "Read CNB20LE Host Bridge Windows" if EXPERT
2264         depends on PCI
2265         help
2266           Read the PCI windows out of the CNB20LE host bridge. This allows
2267           PCI hotplug to work on systems with the CNB20LE chipset which do
2268           not have ACPI.
2269 
2270           There's no public spec for this chipset, and this functionality
2271           is known to be incomplete.
2272 
2273           You should say N unless you know you need this.
2274 
2275 source "drivers/pci/pcie/Kconfig"
2276 
2277 source "drivers/pci/Kconfig"
2278 
2279 # x86_64 have no ISA slots, but can have ISA-style DMA.
2280 config ISA_DMA_API
2281         bool "ISA-style DMA support" if (X86_64 && EXPERT)
2282         default y
2283         help
2284           Enables ISA-style DMA support for devices requiring such controllers.
2285           If unsure, say Y.
2286 
2287 if X86_32
2288 
2289 config ISA
2290         bool "ISA support"
2291         ---help---
2292           Find out whether you have ISA slots on your motherboard.  ISA is the
2293           name of a bus system, i.e. the way the CPU talks to the other stuff
2294           inside your box.  Other bus systems are PCI, EISA, MicroChannel
2295           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2296           newer boards don't support it.  If you have ISA, say Y, otherwise N.
2297 
2298 config EISA
2299         bool "EISA support"
2300         depends on ISA
2301         ---help---
2302           The Extended Industry Standard Architecture (EISA) bus was
2303           developed as an open alternative to the IBM MicroChannel bus.
2304 
2305           The EISA bus provided some of the features of the IBM MicroChannel
2306           bus while maintaining backward compatibility with cards made for
2307           the older ISA bus.  The EISA bus saw limited use between 1988 and
2308           1995 when it was made obsolete by the PCI bus.
2309 
2310           Say Y here if you are building a kernel for an EISA-based machine.
2311 
2312           Otherwise, say N.
2313 
2314 source "drivers/eisa/Kconfig"
2315 
2316 config SCx200
2317         tristate "NatSemi SCx200 support"
2318         ---help---
2319           This provides basic support for National Semiconductor's
2320           (now AMD's) Geode processors.  The driver probes for the
2321           PCI-IDs of several on-chip devices, so its a good dependency
2322           for other scx200_* drivers.
2323 
2324           If compiled as a module, the driver is named scx200.
2325 
2326 config SCx200HR_TIMER
2327         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2328         depends on SCx200
2329         default y
2330         ---help---
2331           This driver provides a clocksource built upon the on-chip
2332           27MHz high-resolution timer.  Its also a workaround for
2333           NSC Geode SC-1100's buggy TSC, which loses time when the
2334           processor goes idle (as is done by the scheduler).  The
2335           other workaround is idle=poll boot option.
2336 
2337 config OLPC
2338         bool "One Laptop Per Child support"
2339         depends on !X86_PAE
2340         select GPIOLIB
2341         select OF
2342         select OF_PROMTREE
2343         select IRQ_DOMAIN
2344         ---help---
2345           Add support for detecting the unique features of the OLPC
2346           XO hardware.
2347 
2348 config OLPC_XO1_PM
2349         bool "OLPC XO-1 Power Management"
2350         depends on OLPC && MFD_CS5535 && PM_SLEEP
2351         select MFD_CORE
2352         ---help---
2353           Add support for poweroff and suspend of the OLPC XO-1 laptop.
2354 
2355 config OLPC_XO1_RTC
2356         bool "OLPC XO-1 Real Time Clock"
2357         depends on OLPC_XO1_PM && RTC_DRV_CMOS
2358         ---help---
2359           Add support for the XO-1 real time clock, which can be used as a
2360           programmable wakeup source.
2361 
2362 config OLPC_XO1_SCI
2363         bool "OLPC XO-1 SCI extras"
2364         depends on OLPC && OLPC_XO1_PM
2365         depends on INPUT=y
2366         select POWER_SUPPLY
2367         select GPIO_CS5535
2368         select MFD_CORE
2369         ---help---
2370           Add support for SCI-based features of the OLPC XO-1 laptop:
2371            - EC-driven system wakeups
2372            - Power button
2373            - Ebook switch
2374            - Lid switch
2375            - AC adapter status updates
2376            - Battery status updates
2377 
2378 config OLPC_XO15_SCI
2379         bool "OLPC XO-1.5 SCI extras"
2380         depends on OLPC && ACPI
2381         select POWER_SUPPLY
2382         ---help---
2383           Add support for SCI-based features of the OLPC XO-1.5 laptop:
2384            - EC-driven system wakeups
2385            - AC adapter status updates
2386            - Battery status updates
2387 
2388 config ALIX
2389         bool "PCEngines ALIX System Support (LED setup)"
2390         select GPIOLIB
2391         ---help---
2392           This option enables system support for the PCEngines ALIX.
2393           At present this just sets up LEDs for GPIO control on
2394           ALIX2/3/6 boards.  However, other system specific setup should
2395           get added here.
2396 
2397           Note: You must still enable the drivers for GPIO and LED support
2398           (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2399 
2400           Note: You have to set alix.force=1 for boards with Award BIOS.
2401 
2402 config NET5501
2403         bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2404         select GPIOLIB
2405         ---help---
2406           This option enables system support for the Soekris Engineering net5501.
2407 
2408 config GEOS
2409         bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2410         select GPIOLIB
2411         depends on DMI
2412         ---help---
2413           This option enables system support for the Traverse Technologies GEOS.
2414 
2415 config TS5500
2416         bool "Technologic Systems TS-5500 platform support"
2417         depends on MELAN
2418         select CHECK_SIGNATURE
2419         select NEW_LEDS
2420         select LEDS_CLASS
2421         ---help---
2422           This option enables system support for the Technologic Systems TS-5500.
2423 
2424 endif # X86_32
2425 
2426 config AMD_NB
2427         def_bool y
2428         depends on CPU_SUP_AMD && PCI
2429 
2430 source "drivers/pcmcia/Kconfig"
2431 
2432 source "drivers/pci/hotplug/Kconfig"
2433 
2434 config RAPIDIO
2435         tristate "RapidIO support"
2436         depends on PCI
2437         default n
2438         help
2439           If enabled this option will include drivers and the core
2440           infrastructure code to support RapidIO interconnect devices.
2441 
2442 source "drivers/rapidio/Kconfig"
2443 
2444 config X86_SYSFB
2445         bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2446         help
2447           Firmwares often provide initial graphics framebuffers so the BIOS,
2448           bootloader or kernel can show basic video-output during boot for
2449           user-guidance and debugging. Historically, x86 used the VESA BIOS
2450           Extensions and EFI-framebuffers for this, which are mostly limited
2451           to x86.
2452           This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2453           framebuffers so the new generic system-framebuffer drivers can be
2454           used on x86. If the framebuffer is not compatible with the generic
2455           modes, it is adverticed as fallback platform framebuffer so legacy
2456           drivers like efifb, vesafb and uvesafb can pick it up.
2457           If this option is not selected, all system framebuffers are always
2458           marked as fallback platform framebuffers as usual.
2459 
2460           Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2461           not be able to pick up generic system framebuffers if this option
2462           is selected. You are highly encouraged to enable simplefb as
2463           replacement if you select this option. simplefb can correctly deal
2464           with generic system framebuffers. But you should still keep vesafb
2465           and others enabled as fallback if a system framebuffer is
2466           incompatible with simplefb.
2467 
2468           If unsure, say Y.
2469 
2470 endmenu
2471 
2472 
2473 menu "Executable file formats / Emulations"
2474 
2475 source "fs/Kconfig.binfmt"
2476 
2477 config IA32_EMULATION
2478         bool "IA32 Emulation"
2479         depends on X86_64
2480         select BINFMT_ELF
2481         select COMPAT_BINFMT_ELF
2482         select HAVE_UID16
2483         ---help---
2484           Include code to run legacy 32-bit programs under a
2485           64-bit kernel. You should likely turn this on, unless you're
2486           100% sure that you don't have any 32-bit programs left.
2487 
2488 config IA32_AOUT
2489         tristate "IA32 a.out support"
2490         depends on IA32_EMULATION
2491         ---help---
2492           Support old a.out binaries in the 32bit emulation.
2493 
2494 config X86_X32
2495         bool "x32 ABI for 64-bit mode"
2496         depends on X86_64 && IA32_EMULATION
2497         ---help---
2498           Include code to run binaries for the x32 native 32-bit ABI
2499           for 64-bit processors.  An x32 process gets access to the
2500           full 64-bit register file and wide data path while leaving
2501           pointers at 32 bits for smaller memory footprint.
2502 
2503           You will need a recent binutils (2.22 or later) with
2504           elf32_x86_64 support enabled to compile a kernel with this
2505           option set.
2506 
2507 config COMPAT
2508         def_bool y
2509         depends on IA32_EMULATION || X86_X32
2510         select ARCH_WANT_OLD_COMPAT_IPC
2511 
2512 if COMPAT
2513 config COMPAT_FOR_U64_ALIGNMENT
2514         def_bool y
2515 
2516 config SYSVIPC_COMPAT
2517         def_bool y
2518         depends on SYSVIPC
2519 
2520 config KEYS_COMPAT
2521         def_bool y
2522         depends on KEYS
2523 endif
2524 
2525 endmenu
2526 
2527 
2528 config HAVE_ATOMIC_IOMAP
2529         def_bool y
2530         depends on X86_32
2531 
2532 config X86_DEV_DMA_OPS
2533         bool
2534         depends on X86_64 || STA2X11
2535 
2536 config X86_DMA_REMAP
2537         bool
2538         depends on STA2X11
2539 
2540 config PMC_ATOM
2541         def_bool y
2542         depends on PCI
2543 
2544 source "net/Kconfig"
2545 
2546 source "drivers/Kconfig"
2547 
2548 source "drivers/firmware/Kconfig"
2549 
2550 source "fs/Kconfig"
2551 
2552 source "arch/x86/Kconfig.debug"
2553 
2554 source "security/Kconfig"
2555 
2556 source "crypto/Kconfig"
2557 
2558 source "arch/x86/kvm/Kconfig"
2559 
2560 source "lib/Kconfig"

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