Version:  2.0.40 2.2.26 2.4.37 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 4.0

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         select HAVE_LIVEPATCH
 21 
 22 ### Arch settings
 23 config X86
 24         def_bool y
 25         select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 26         select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 27         select ARCH_HAS_FAST_MULTIPLIER
 28         select ARCH_HAS_GCOV_PROFILE_ALL
 29         select ARCH_MIGHT_HAVE_PC_PARPORT
 30         select ARCH_MIGHT_HAVE_PC_SERIO
 31         select HAVE_AOUT if X86_32
 32         select HAVE_UNSTABLE_SCHED_CLOCK
 33         select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
 34         select ARCH_SUPPORTS_INT128 if X86_64
 35         select HAVE_IDE
 36         select HAVE_OPROFILE
 37         select HAVE_PCSPKR_PLATFORM
 38         select HAVE_PERF_EVENTS
 39         select HAVE_IOREMAP_PROT
 40         select HAVE_KPROBES
 41         select HAVE_MEMBLOCK
 42         select HAVE_MEMBLOCK_NODE_MAP
 43         select ARCH_DISCARD_MEMBLOCK
 44         select ARCH_WANT_OPTIONAL_GPIOLIB
 45         select ARCH_WANT_FRAME_POINTERS
 46         select HAVE_DMA_ATTRS
 47         select HAVE_DMA_CONTIGUOUS
 48         select HAVE_KRETPROBES
 49         select GENERIC_EARLY_IOREMAP
 50         select HAVE_OPTPROBES
 51         select HAVE_KPROBES_ON_FTRACE
 52         select HAVE_FTRACE_MCOUNT_RECORD
 53         select HAVE_FENTRY if X86_64
 54         select HAVE_C_RECORDMCOUNT
 55         select HAVE_DYNAMIC_FTRACE
 56         select HAVE_DYNAMIC_FTRACE_WITH_REGS
 57         select HAVE_FUNCTION_TRACER
 58         select HAVE_FUNCTION_GRAPH_TRACER
 59         select HAVE_FUNCTION_GRAPH_FP_TEST
 60         select HAVE_SYSCALL_TRACEPOINTS
 61         select SYSCTL_EXCEPTION_TRACE
 62         select HAVE_KVM
 63         select HAVE_ARCH_KGDB
 64         select HAVE_ARCH_TRACEHOOK
 65         select HAVE_GENERIC_DMA_COHERENT if X86_32
 66         select HAVE_EFFICIENT_UNALIGNED_ACCESS
 67         select USER_STACKTRACE_SUPPORT
 68         select HAVE_REGS_AND_STACK_ACCESS_API
 69         select HAVE_DMA_API_DEBUG
 70         select HAVE_KERNEL_GZIP
 71         select HAVE_KERNEL_BZIP2
 72         select HAVE_KERNEL_LZMA
 73         select HAVE_KERNEL_XZ
 74         select HAVE_KERNEL_LZO
 75         select HAVE_KERNEL_LZ4
 76         select HAVE_HW_BREAKPOINT
 77         select HAVE_MIXED_BREAKPOINTS_REGS
 78         select PERF_EVENTS
 79         select HAVE_PERF_EVENTS_NMI
 80         select HAVE_PERF_REGS
 81         select HAVE_PERF_USER_STACK_DUMP
 82         select HAVE_DEBUG_KMEMLEAK
 83         select ANON_INODES
 84         select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 85         select HAVE_CMPXCHG_LOCAL
 86         select HAVE_CMPXCHG_DOUBLE
 87         select HAVE_ARCH_KMEMCHECK
 88         select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
 89         select HAVE_USER_RETURN_NOTIFIER
 90         select ARCH_BINFMT_ELF_RANDOMIZE_PIE
 91         select HAVE_ARCH_JUMP_LABEL
 92         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 93         select SPARSE_IRQ
 94         select GENERIC_FIND_FIRST_BIT
 95         select GENERIC_IRQ_PROBE
 96         select GENERIC_PENDING_IRQ if SMP
 97         select GENERIC_IRQ_SHOW
 98         select GENERIC_CLOCKEVENTS_MIN_ADJUST
 99         select IRQ_FORCED_THREADING
100         select HAVE_BPF_JIT if X86_64
101         select HAVE_ARCH_TRANSPARENT_HUGEPAGE
102         select ARCH_HAS_SG_CHAIN
103         select CLKEVT_I8253
104         select ARCH_HAVE_NMI_SAFE_CMPXCHG
105         select GENERIC_IOMAP
106         select DCACHE_WORD_ACCESS
107         select GENERIC_SMP_IDLE_THREAD
108         select ARCH_WANT_IPC_PARSE_VERSION if X86_32
109         select HAVE_ARCH_SECCOMP_FILTER
110         select BUILDTIME_EXTABLE_SORT
111         select GENERIC_CMOS_UPDATE
112         select HAVE_ARCH_SOFT_DIRTY if X86_64
113         select CLOCKSOURCE_WATCHDOG
114         select GENERIC_CLOCKEVENTS
115         select ARCH_CLOCKSOURCE_DATA
116         select CLOCKSOURCE_VALIDATE_LAST_CYCLE
117         select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
118         select GENERIC_TIME_VSYSCALL
119         select GENERIC_STRNCPY_FROM_USER
120         select GENERIC_STRNLEN_USER
121         select HAVE_CONTEXT_TRACKING if X86_64
122         select HAVE_IRQ_TIME_ACCOUNTING
123         select VIRT_TO_BUS
124         select MODULES_USE_ELF_REL if X86_32
125         select MODULES_USE_ELF_RELA if X86_64
126         select CLONE_BACKWARDS if X86_32
127         select ARCH_USE_BUILTIN_BSWAP
128         select ARCH_USE_QUEUE_RWLOCK
129         select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
130         select OLD_SIGACTION if X86_32
131         select COMPAT_OLD_SIGACTION if IA32_EMULATION
132         select RTC_LIB
133         select HAVE_DEBUG_STACKOVERFLOW
134         select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
135         select HAVE_CC_STACKPROTECTOR
136         select GENERIC_CPU_AUTOPROBE
137         select HAVE_ARCH_AUDITSYSCALL
138         select ARCH_SUPPORTS_ATOMIC_RMW
139         select HAVE_ACPI_APEI if ACPI
140         select HAVE_ACPI_APEI_NMI if ACPI
141         select ACPI_LEGACY_TABLES_LOOKUP if ACPI
142         select X86_FEATURE_NAMES if PROC_FS
143         select SRCU
144 
145 config INSTRUCTION_DECODER
146         def_bool y
147         depends on KPROBES || PERF_EVENTS || UPROBES
148 
149 config PERF_EVENTS_INTEL_UNCORE
150         def_bool y
151         depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
152 
153 config OUTPUT_FORMAT
154         string
155         default "elf32-i386" if X86_32
156         default "elf64-x86-64" if X86_64
157 
158 config ARCH_DEFCONFIG
159         string
160         default "arch/x86/configs/i386_defconfig" if X86_32
161         default "arch/x86/configs/x86_64_defconfig" if X86_64
162 
163 config LOCKDEP_SUPPORT
164         def_bool y
165 
166 config STACKTRACE_SUPPORT
167         def_bool y
168 
169 config HAVE_LATENCYTOP_SUPPORT
170         def_bool y
171 
172 config MMU
173         def_bool y
174 
175 config SBUS
176         bool
177 
178 config NEED_DMA_MAP_STATE
179         def_bool y
180         depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
181 
182 config NEED_SG_DMA_LENGTH
183         def_bool y
184 
185 config GENERIC_ISA_DMA
186         def_bool y
187         depends on ISA_DMA_API
188 
189 config GENERIC_BUG
190         def_bool y
191         depends on BUG
192         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
193 
194 config GENERIC_BUG_RELATIVE_POINTERS
195         bool
196 
197 config GENERIC_HWEIGHT
198         def_bool y
199 
200 config ARCH_MAY_HAVE_PC_FDC
201         def_bool y
202         depends on ISA_DMA_API
203 
204 config RWSEM_XCHGADD_ALGORITHM
205         def_bool y
206 
207 config GENERIC_CALIBRATE_DELAY
208         def_bool y
209 
210 config ARCH_HAS_CPU_RELAX
211         def_bool y
212 
213 config ARCH_HAS_CACHE_LINE_SIZE
214         def_bool y
215 
216 config HAVE_SETUP_PER_CPU_AREA
217         def_bool y
218 
219 config NEED_PER_CPU_EMBED_FIRST_CHUNK
220         def_bool y
221 
222 config NEED_PER_CPU_PAGE_FIRST_CHUNK
223         def_bool y
224 
225 config ARCH_HIBERNATION_POSSIBLE
226         def_bool y
227 
228 config ARCH_SUSPEND_POSSIBLE
229         def_bool y
230 
231 config ARCH_WANT_HUGE_PMD_SHARE
232         def_bool y
233 
234 config ARCH_WANT_GENERAL_HUGETLB
235         def_bool y
236 
237 config ZONE_DMA32
238         bool
239         default X86_64
240 
241 config AUDIT_ARCH
242         bool
243         default X86_64
244 
245 config ARCH_SUPPORTS_OPTIMIZED_INLINING
246         def_bool y
247 
248 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
249         def_bool y
250 
251 config HAVE_INTEL_TXT
252         def_bool y
253         depends on INTEL_IOMMU && ACPI
254 
255 config X86_32_SMP
256         def_bool y
257         depends on X86_32 && SMP
258 
259 config X86_64_SMP
260         def_bool y
261         depends on X86_64 && SMP
262 
263 config X86_HT
264         def_bool y
265         depends on SMP
266 
267 config X86_32_LAZY_GS
268         def_bool y
269         depends on X86_32 && !CC_STACKPROTECTOR
270 
271 config ARCH_HWEIGHT_CFLAGS
272         string
273         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
274         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
275 
276 config ARCH_SUPPORTS_UPROBES
277         def_bool y
278 
279 config FIX_EARLYCON_MEM
280         def_bool y
281 
282 source "init/Kconfig"
283 source "kernel/Kconfig.freezer"
284 
285 menu "Processor type and features"
286 
287 config ZONE_DMA
288         bool "DMA memory allocation support" if EXPERT
289         default y
290         help
291           DMA memory allocation support allows devices with less than 32-bit
292           addressing to allocate within the first 16MB of address space.
293           Disable if no such devices will be used.
294 
295           If unsure, say Y.
296 
297 config SMP
298         bool "Symmetric multi-processing support"
299         ---help---
300           This enables support for systems with more than one CPU. If you have
301           a system with only one CPU, say N. If you have a system with more
302           than one CPU, say Y.
303 
304           If you say N here, the kernel will run on uni- and multiprocessor
305           machines, but will use only one CPU of a multiprocessor machine. If
306           you say Y here, the kernel will run on many, but not all,
307           uniprocessor machines. On a uniprocessor machine, the kernel
308           will run faster if you say N here.
309 
310           Note that if you say Y here and choose architecture "586" or
311           "Pentium" under "Processor family", the kernel will not work on 486
312           architectures. Similarly, multiprocessor kernels for the "PPro"
313           architecture may not work on all Pentium based boards.
314 
315           People using multiprocessor machines who say Y here should also say
316           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
317           Management" code will be disabled if you say Y here.
318 
319           See also <file:Documentation/x86/i386/IO-APIC.txt>,
320           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
321           <http://www.tldp.org/docs.html#howto>.
322 
323           If you don't know what to do here, say N.
324 
325 config X86_FEATURE_NAMES
326         bool "Processor feature human-readable names" if EMBEDDED
327         default y
328         ---help---
329           This option compiles in a table of x86 feature bits and corresponding
330           names.  This is required to support /proc/cpuinfo and a few kernel
331           messages.  You can disable this to save space, at the expense of
332           making those few kernel messages show numeric feature bits instead.
333 
334           If in doubt, say Y.
335 
336 config X86_X2APIC
337         bool "Support x2apic"
338         depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
339         ---help---
340           This enables x2apic support on CPUs that have this feature.
341 
342           This allows 32-bit apic IDs (so it can support very large systems),
343           and accesses the local apic via MSRs not via mmio.
344 
345           If you don't know what to do here, say N.
346 
347 config X86_MPPARSE
348         bool "Enable MPS table" if ACPI || SFI
349         default y
350         depends on X86_LOCAL_APIC
351         ---help---
352           For old smp systems that do not have proper acpi support. Newer systems
353           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
354 
355 config X86_BIGSMP
356         bool "Support for big SMP systems with more than 8 CPUs"
357         depends on X86_32 && SMP
358         ---help---
359           This option is needed for the systems that have more than 8 CPUs
360 
361 config GOLDFISH
362        def_bool y
363        depends on X86_GOLDFISH
364 
365 if X86_32
366 config X86_EXTENDED_PLATFORM
367         bool "Support for extended (non-PC) x86 platforms"
368         default y
369         ---help---
370           If you disable this option then the kernel will only support
371           standard PC platforms. (which covers the vast majority of
372           systems out there.)
373 
374           If you enable this option then you'll be able to select support
375           for the following (non-PC) 32 bit x86 platforms:
376                 Goldfish (Android emulator)
377                 AMD Elan
378                 RDC R-321x SoC
379                 SGI 320/540 (Visual Workstation)
380                 STA2X11-based (e.g. Northville)
381                 Moorestown MID devices
382 
383           If you have one of these systems, or if you want to build a
384           generic distribution kernel, say Y here - otherwise say N.
385 endif
386 
387 if X86_64
388 config X86_EXTENDED_PLATFORM
389         bool "Support for extended (non-PC) x86 platforms"
390         default y
391         ---help---
392           If you disable this option then the kernel will only support
393           standard PC platforms. (which covers the vast majority of
394           systems out there.)
395 
396           If you enable this option then you'll be able to select support
397           for the following (non-PC) 64 bit x86 platforms:
398                 Numascale NumaChip
399                 ScaleMP vSMP
400                 SGI Ultraviolet
401 
402           If you have one of these systems, or if you want to build a
403           generic distribution kernel, say Y here - otherwise say N.
404 endif
405 # This is an alphabetically sorted list of 64 bit extended platforms
406 # Please maintain the alphabetic order if and when there are additions
407 config X86_NUMACHIP
408         bool "Numascale NumaChip"
409         depends on X86_64
410         depends on X86_EXTENDED_PLATFORM
411         depends on NUMA
412         depends on SMP
413         depends on X86_X2APIC
414         depends on PCI_MMCONFIG
415         ---help---
416           Adds support for Numascale NumaChip large-SMP systems. Needed to
417           enable more than ~168 cores.
418           If you don't have one of these, you should say N here.
419 
420 config X86_VSMP
421         bool "ScaleMP vSMP"
422         select HYPERVISOR_GUEST
423         select PARAVIRT
424         depends on X86_64 && PCI
425         depends on X86_EXTENDED_PLATFORM
426         depends on SMP
427         ---help---
428           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
429           supposed to run on these EM64T-based machines.  Only choose this option
430           if you have one of these machines.
431 
432 config X86_UV
433         bool "SGI Ultraviolet"
434         depends on X86_64
435         depends on X86_EXTENDED_PLATFORM
436         depends on NUMA
437         depends on X86_X2APIC
438         ---help---
439           This option is needed in order to support SGI Ultraviolet systems.
440           If you don't have one of these, you should say N here.
441 
442 # Following is an alphabetically sorted list of 32 bit extended platforms
443 # Please maintain the alphabetic order if and when there are additions
444 
445 config X86_GOLDFISH
446        bool "Goldfish (Virtual Platform)"
447        depends on X86_EXTENDED_PLATFORM
448        ---help---
449          Enable support for the Goldfish virtual platform used primarily
450          for Android development. Unless you are building for the Android
451          Goldfish emulator say N here.
452 
453 config X86_INTEL_CE
454         bool "CE4100 TV platform"
455         depends on PCI
456         depends on PCI_GODIRECT
457         depends on X86_IO_APIC
458         depends on X86_32
459         depends on X86_EXTENDED_PLATFORM
460         select X86_REBOOTFIXUPS
461         select OF
462         select OF_EARLY_FLATTREE
463         select IRQ_DOMAIN
464         ---help---
465           Select for the Intel CE media processor (CE4100) SOC.
466           This option compiles in support for the CE4100 SOC for settop
467           boxes and media devices.
468 
469 config X86_INTEL_MID
470         bool "Intel MID platform support"
471         depends on X86_32
472         depends on X86_EXTENDED_PLATFORM
473         depends on X86_PLATFORM_DEVICES
474         depends on PCI
475         depends on PCI_GOANY
476         depends on X86_IO_APIC
477         select SFI
478         select I2C
479         select DW_APB_TIMER
480         select APB_TIMER
481         select INTEL_SCU_IPC
482         select MFD_INTEL_MSIC
483         ---help---
484           Select to build a kernel capable of supporting Intel MID (Mobile
485           Internet Device) platform systems which do not have the PCI legacy
486           interfaces. If you are building for a PC class system say N here.
487 
488           Intel MID platforms are based on an Intel processor and chipset which
489           consume less power than most of the x86 derivatives.
490 
491 config X86_INTEL_QUARK
492         bool "Intel Quark platform support"
493         depends on X86_32
494         depends on X86_EXTENDED_PLATFORM
495         depends on X86_PLATFORM_DEVICES
496         depends on X86_TSC
497         depends on PCI
498         depends on PCI_GOANY
499         depends on X86_IO_APIC
500         select IOSF_MBI
501         select INTEL_IMR
502         select COMMON_CLK
503         ---help---
504           Select to include support for Quark X1000 SoC.
505           Say Y here if you have a Quark based system such as the Arduino
506           compatible Intel Galileo.
507 
508 config X86_INTEL_LPSS
509         bool "Intel Low Power Subsystem Support"
510         depends on ACPI
511         select COMMON_CLK
512         select PINCTRL
513         ---help---
514           Select to build support for Intel Low Power Subsystem such as
515           found on Intel Lynxpoint PCH. Selecting this option enables
516           things like clock tree (common clock framework) and pincontrol
517           which are needed by the LPSS peripheral drivers.
518 
519 config X86_AMD_PLATFORM_DEVICE
520         bool "AMD ACPI2Platform devices support"
521         depends on ACPI
522         select COMMON_CLK
523         select PINCTRL
524         ---help---
525           Select to interpret AMD specific ACPI device to platform device
526           such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
527           I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
528           implemented under PINCTRL subsystem.
529 
530 config IOSF_MBI
531         tristate "Intel SoC IOSF Sideband support for SoC platforms"
532         depends on PCI
533         ---help---
534           This option enables sideband register access support for Intel SoC
535           platforms. On these platforms the IOSF sideband is used in lieu of
536           MSR's for some register accesses, mostly but not limited to thermal
537           and power. Drivers may query the availability of this device to
538           determine if they need the sideband in order to work on these
539           platforms. The sideband is available on the following SoC products.
540           This list is not meant to be exclusive.
541            - BayTrail
542            - Braswell
543            - Quark
544 
545           You should say Y if you are running a kernel on one of these SoC's.
546 
547 config IOSF_MBI_DEBUG
548         bool "Enable IOSF sideband access through debugfs"
549         depends on IOSF_MBI && DEBUG_FS
550         ---help---
551           Select this option to expose the IOSF sideband access registers (MCR,
552           MDR, MCRX) through debugfs to write and read register information from
553           different units on the SoC. This is most useful for obtaining device
554           state information for debug and analysis. As this is a general access
555           mechanism, users of this option would have specific knowledge of the
556           device they want to access.
557 
558           If you don't require the option or are in doubt, say N.
559 
560 config X86_RDC321X
561         bool "RDC R-321x SoC"
562         depends on X86_32
563         depends on X86_EXTENDED_PLATFORM
564         select M486
565         select X86_REBOOTFIXUPS
566         ---help---
567           This option is needed for RDC R-321x system-on-chip, also known
568           as R-8610-(G).
569           If you don't have one of these chips, you should say N here.
570 
571 config X86_32_NON_STANDARD
572         bool "Support non-standard 32-bit SMP architectures"
573         depends on X86_32 && SMP
574         depends on X86_EXTENDED_PLATFORM
575         ---help---
576           This option compiles in the bigsmp and STA2X11 default
577           subarchitectures.  It is intended for a generic binary
578           kernel. If you select them all, kernel will probe it one by
579           one and will fallback to default.
580 
581 # Alphabetically sorted list of Non standard 32 bit platforms
582 
583 config X86_SUPPORTS_MEMORY_FAILURE
584         def_bool y
585         # MCE code calls memory_failure():
586         depends on X86_MCE
587         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
588         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
589         depends on X86_64 || !SPARSEMEM
590         select ARCH_SUPPORTS_MEMORY_FAILURE
591 
592 config STA2X11
593         bool "STA2X11 Companion Chip Support"
594         depends on X86_32_NON_STANDARD && PCI
595         select X86_DEV_DMA_OPS
596         select X86_DMA_REMAP
597         select SWIOTLB
598         select MFD_STA2X11
599         select ARCH_REQUIRE_GPIOLIB
600         default n
601         ---help---
602           This adds support for boards based on the STA2X11 IO-Hub,
603           a.k.a. "ConneXt". The chip is used in place of the standard
604           PC chipset, so all "standard" peripherals are missing. If this
605           option is selected the kernel will still be able to boot on
606           standard PC machines.
607 
608 config X86_32_IRIS
609         tristate "Eurobraille/Iris poweroff module"
610         depends on X86_32
611         ---help---
612           The Iris machines from EuroBraille do not have APM or ACPI support
613           to shut themselves down properly.  A special I/O sequence is
614           needed to do so, which is what this module does at
615           kernel shutdown.
616 
617           This is only for Iris machines from EuroBraille.
618 
619           If unused, say N.
620 
621 config SCHED_OMIT_FRAME_POINTER
622         def_bool y
623         prompt "Single-depth WCHAN output"
624         depends on X86
625         ---help---
626           Calculate simpler /proc/<PID>/wchan values. If this option
627           is disabled then wchan values will recurse back to the
628           caller function. This provides more accurate wchan values,
629           at the expense of slightly more scheduling overhead.
630 
631           If in doubt, say "Y".
632 
633 menuconfig HYPERVISOR_GUEST
634         bool "Linux guest support"
635         ---help---
636           Say Y here to enable options for running Linux under various hyper-
637           visors. This option enables basic hypervisor detection and platform
638           setup.
639 
640           If you say N, all options in this submenu will be skipped and
641           disabled, and Linux guest support won't be built in.
642 
643 if HYPERVISOR_GUEST
644 
645 config PARAVIRT
646         bool "Enable paravirtualization code"
647         ---help---
648           This changes the kernel so it can modify itself when it is run
649           under a hypervisor, potentially improving performance significantly
650           over full virtualization.  However, when run without a hypervisor
651           the kernel is theoretically slower and slightly larger.
652 
653 config PARAVIRT_DEBUG
654         bool "paravirt-ops debugging"
655         depends on PARAVIRT && DEBUG_KERNEL
656         ---help---
657           Enable to debug paravirt_ops internals.  Specifically, BUG if
658           a paravirt_op is missing when it is called.
659 
660 config PARAVIRT_SPINLOCKS
661         bool "Paravirtualization layer for spinlocks"
662         depends on PARAVIRT && SMP
663         select UNINLINE_SPIN_UNLOCK
664         ---help---
665           Paravirtualized spinlocks allow a pvops backend to replace the
666           spinlock implementation with something virtualization-friendly
667           (for example, block the virtual CPU rather than spinning).
668 
669           It has a minimal impact on native kernels and gives a nice performance
670           benefit on paravirtualized KVM / Xen kernels.
671 
672           If you are unsure how to answer this question, answer Y.
673 
674 source "arch/x86/xen/Kconfig"
675 
676 config KVM_GUEST
677         bool "KVM Guest support (including kvmclock)"
678         depends on PARAVIRT
679         select PARAVIRT_CLOCK
680         default y
681         ---help---
682           This option enables various optimizations for running under the KVM
683           hypervisor. It includes a paravirtualized clock, so that instead
684           of relying on a PIT (or probably other) emulation by the
685           underlying device model, the host provides the guest with
686           timing infrastructure such as time of day, and system time
687 
688 config KVM_DEBUG_FS
689         bool "Enable debug information for KVM Guests in debugfs"
690         depends on KVM_GUEST && DEBUG_FS
691         default n
692         ---help---
693           This option enables collection of various statistics for KVM guest.
694           Statistics are displayed in debugfs filesystem. Enabling this option
695           may incur significant overhead.
696 
697 source "arch/x86/lguest/Kconfig"
698 
699 config PARAVIRT_TIME_ACCOUNTING
700         bool "Paravirtual steal time accounting"
701         depends on PARAVIRT
702         default n
703         ---help---
704           Select this option to enable fine granularity task steal time
705           accounting. Time spent executing other tasks in parallel with
706           the current vCPU is discounted from the vCPU power. To account for
707           that, there can be a small performance impact.
708 
709           If in doubt, say N here.
710 
711 config PARAVIRT_CLOCK
712         bool
713 
714 endif #HYPERVISOR_GUEST
715 
716 config NO_BOOTMEM
717         def_bool y
718 
719 config MEMTEST
720         bool "Memtest"
721         ---help---
722           This option adds a kernel parameter 'memtest', which allows memtest
723           to be set.
724                 memtest=0, mean disabled; -- default
725                 memtest=1, mean do 1 test pattern;
726                 ...
727                 memtest=4, mean do 4 test patterns.
728           If you are unsure how to answer this question, answer N.
729 
730 source "arch/x86/Kconfig.cpu"
731 
732 config HPET_TIMER
733         def_bool X86_64
734         prompt "HPET Timer Support" if X86_32
735         ---help---
736           Use the IA-PC HPET (High Precision Event Timer) to manage
737           time in preference to the PIT and RTC, if a HPET is
738           present.
739           HPET is the next generation timer replacing legacy 8254s.
740           The HPET provides a stable time base on SMP
741           systems, unlike the TSC, but it is more expensive to access,
742           as it is off-chip.  You can find the HPET spec at
743           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
744 
745           You can safely choose Y here.  However, HPET will only be
746           activated if the platform and the BIOS support this feature.
747           Otherwise the 8254 will be used for timing services.
748 
749           Choose N to continue using the legacy 8254 timer.
750 
751 config HPET_EMULATE_RTC
752         def_bool y
753         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
754 
755 config APB_TIMER
756        def_bool y if X86_INTEL_MID
757        prompt "Intel MID APB Timer Support" if X86_INTEL_MID
758        select DW_APB_TIMER
759        depends on X86_INTEL_MID && SFI
760        help
761          APB timer is the replacement for 8254, HPET on X86 MID platforms.
762          The APBT provides a stable time base on SMP
763          systems, unlike the TSC, but it is more expensive to access,
764          as it is off-chip. APB timers are always running regardless of CPU
765          C states, they are used as per CPU clockevent device when possible.
766 
767 # Mark as expert because too many people got it wrong.
768 # The code disables itself when not needed.
769 config DMI
770         default y
771         select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
772         bool "Enable DMI scanning" if EXPERT
773         ---help---
774           Enabled scanning of DMI to identify machine quirks. Say Y
775           here unless you have verified that your setup is not
776           affected by entries in the DMI blacklist. Required by PNP
777           BIOS code.
778 
779 config GART_IOMMU
780         bool "Old AMD GART IOMMU support"
781         select SWIOTLB
782         depends on X86_64 && PCI && AMD_NB
783         ---help---
784           Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
785           GART based hardware IOMMUs.
786 
787           The GART supports full DMA access for devices with 32-bit access
788           limitations, on systems with more than 3 GB. This is usually needed
789           for USB, sound, many IDE/SATA chipsets and some other devices.
790 
791           Newer systems typically have a modern AMD IOMMU, supported via
792           the CONFIG_AMD_IOMMU=y config option.
793 
794           In normal configurations this driver is only active when needed:
795           there's more than 3 GB of memory and the system contains a
796           32-bit limited device.
797 
798           If unsure, say Y.
799 
800 config CALGARY_IOMMU
801         bool "IBM Calgary IOMMU support"
802         select SWIOTLB
803         depends on X86_64 && PCI
804         ---help---
805           Support for hardware IOMMUs in IBM's xSeries x366 and x460
806           systems. Needed to run systems with more than 3GB of memory
807           properly with 32-bit PCI devices that do not support DAC
808           (Double Address Cycle). Calgary also supports bus level
809           isolation, where all DMAs pass through the IOMMU.  This
810           prevents them from going anywhere except their intended
811           destination. This catches hard-to-find kernel bugs and
812           mis-behaving drivers and devices that do not use the DMA-API
813           properly to set up their DMA buffers.  The IOMMU can be
814           turned off at boot time with the iommu=off parameter.
815           Normally the kernel will make the right choice by itself.
816           If unsure, say Y.
817 
818 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
819         def_bool y
820         prompt "Should Calgary be enabled by default?"
821         depends on CALGARY_IOMMU
822         ---help---
823           Should Calgary be enabled by default? if you choose 'y', Calgary
824           will be used (if it exists). If you choose 'n', Calgary will not be
825           used even if it exists. If you choose 'n' and would like to use
826           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
827           If unsure, say Y.
828 
829 # need this always selected by IOMMU for the VIA workaround
830 config SWIOTLB
831         def_bool y if X86_64
832         ---help---
833           Support for software bounce buffers used on x86-64 systems
834           which don't have a hardware IOMMU. Using this PCI devices
835           which can only access 32-bits of memory can be used on systems
836           with more than 3 GB of memory.
837           If unsure, say Y.
838 
839 config IOMMU_HELPER
840         def_bool y
841         depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
842 
843 config MAXSMP
844         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
845         depends on X86_64 && SMP && DEBUG_KERNEL
846         select CPUMASK_OFFSTACK
847         ---help---
848           Enable maximum number of CPUS and NUMA Nodes for this architecture.
849           If unsure, say N.
850 
851 config NR_CPUS
852         int "Maximum number of CPUs" if SMP && !MAXSMP
853         range 2 8 if SMP && X86_32 && !X86_BIGSMP
854         range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
855         range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
856         default "1" if !SMP
857         default "8192" if MAXSMP
858         default "32" if SMP && X86_BIGSMP
859         default "8" if SMP
860         ---help---
861           This allows you to specify the maximum number of CPUs which this
862           kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
863           supported value is 4096, otherwise the maximum value is 512.  The
864           minimum value which makes sense is 2.
865 
866           This is purely to save memory - each supported CPU adds
867           approximately eight kilobytes to the kernel image.
868 
869 config SCHED_SMT
870         bool "SMT (Hyperthreading) scheduler support"
871         depends on X86_HT
872         ---help---
873           SMT scheduler support improves the CPU scheduler's decision making
874           when dealing with Intel Pentium 4 chips with HyperThreading at a
875           cost of slightly increased overhead in some places. If unsure say
876           N here.
877 
878 config SCHED_MC
879         def_bool y
880         prompt "Multi-core scheduler support"
881         depends on X86_HT
882         ---help---
883           Multi-core scheduler support improves the CPU scheduler's decision
884           making when dealing with multi-core CPU chips at a cost of slightly
885           increased overhead in some places. If unsure say N here.
886 
887 source "kernel/Kconfig.preempt"
888 
889 config UP_LATE_INIT
890        def_bool y
891        depends on !SMP && X86_LOCAL_APIC
892 
893 config X86_UP_APIC
894         bool "Local APIC support on uniprocessors"
895         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
896         ---help---
897           A local APIC (Advanced Programmable Interrupt Controller) is an
898           integrated interrupt controller in the CPU. If you have a single-CPU
899           system which has a processor with a local APIC, you can say Y here to
900           enable and use it. If you say Y here even though your machine doesn't
901           have a local APIC, then the kernel will still run with no slowdown at
902           all. The local APIC supports CPU-generated self-interrupts (timer,
903           performance counters), and the NMI watchdog which detects hard
904           lockups.
905 
906 config X86_UP_APIC_MSI
907         def_bool y
908         select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
909 
910 config X86_UP_IOAPIC
911         bool "IO-APIC support on uniprocessors"
912         depends on X86_UP_APIC
913         ---help---
914           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
915           SMP-capable replacement for PC-style interrupt controllers. Most
916           SMP systems and many recent uniprocessor systems have one.
917 
918           If you have a single-CPU system with an IO-APIC, you can say Y here
919           to use it. If you say Y here even though your machine doesn't have
920           an IO-APIC, then the kernel will still run with no slowdown at all.
921 
922 config X86_LOCAL_APIC
923         def_bool y
924         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
925         select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
926 
927 config X86_IO_APIC
928         def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
929         depends on X86_LOCAL_APIC
930         select IRQ_DOMAIN
931 
932 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
933         bool "Reroute for broken boot IRQs"
934         depends on X86_IO_APIC
935         ---help---
936           This option enables a workaround that fixes a source of
937           spurious interrupts. This is recommended when threaded
938           interrupt handling is used on systems where the generation of
939           superfluous "boot interrupts" cannot be disabled.
940 
941           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
942           entry in the chipset's IO-APIC is masked (as, e.g. the RT
943           kernel does during interrupt handling). On chipsets where this
944           boot IRQ generation cannot be disabled, this workaround keeps
945           the original IRQ line masked so that only the equivalent "boot
946           IRQ" is delivered to the CPUs. The workaround also tells the
947           kernel to set up the IRQ handler on the boot IRQ line. In this
948           way only one interrupt is delivered to the kernel. Otherwise
949           the spurious second interrupt may cause the kernel to bring
950           down (vital) interrupt lines.
951 
952           Only affects "broken" chipsets. Interrupt sharing may be
953           increased on these systems.
954 
955 config X86_MCE
956         bool "Machine Check / overheating reporting"
957         default y
958         ---help---
959           Machine Check support allows the processor to notify the
960           kernel if it detects a problem (e.g. overheating, data corruption).
961           The action the kernel takes depends on the severity of the problem,
962           ranging from warning messages to halting the machine.
963 
964 config X86_MCE_INTEL
965         def_bool y
966         prompt "Intel MCE features"
967         depends on X86_MCE && X86_LOCAL_APIC
968         ---help---
969            Additional support for intel specific MCE features such as
970            the thermal monitor.
971 
972 config X86_MCE_AMD
973         def_bool y
974         prompt "AMD MCE features"
975         depends on X86_MCE && X86_LOCAL_APIC
976         ---help---
977            Additional support for AMD specific MCE features such as
978            the DRAM Error Threshold.
979 
980 config X86_ANCIENT_MCE
981         bool "Support for old Pentium 5 / WinChip machine checks"
982         depends on X86_32 && X86_MCE
983         ---help---
984           Include support for machine check handling on old Pentium 5 or WinChip
985           systems. These typically need to be enabled explicitly on the command
986           line.
987 
988 config X86_MCE_THRESHOLD
989         depends on X86_MCE_AMD || X86_MCE_INTEL
990         def_bool y
991 
992 config X86_MCE_INJECT
993         depends on X86_MCE
994         tristate "Machine check injector support"
995         ---help---
996           Provide support for injecting machine checks for testing purposes.
997           If you don't know what a machine check is and you don't do kernel
998           QA it is safe to say n.
999 
1000 config X86_THERMAL_VECTOR
1001         def_bool y
1002         depends on X86_MCE_INTEL
1003 
1004 config VM86
1005         bool "Enable VM86 support" if EXPERT
1006         default y
1007         depends on X86_32
1008         ---help---
1009           This option is required by programs like DOSEMU to run
1010           16-bit real mode legacy code on x86 processors. It also may
1011           be needed by software like XFree86 to initialize some video
1012           cards via BIOS. Disabling this option saves about 6K.
1013 
1014 config X86_16BIT
1015         bool "Enable support for 16-bit segments" if EXPERT
1016         default y
1017         ---help---
1018           This option is required by programs like Wine to run 16-bit
1019           protected mode legacy code on x86 processors.  Disabling
1020           this option saves about 300 bytes on i386, or around 6K text
1021           plus 16K runtime memory on x86-64,
1022 
1023 config X86_ESPFIX32
1024         def_bool y
1025         depends on X86_16BIT && X86_32
1026 
1027 config X86_ESPFIX64
1028         def_bool y
1029         depends on X86_16BIT && X86_64
1030 
1031 config X86_VSYSCALL_EMULATION
1032        bool "Enable vsyscall emulation" if EXPERT
1033        default y
1034        depends on X86_64
1035        ---help---
1036          This enables emulation of the legacy vsyscall page.  Disabling
1037          it is roughly equivalent to booting with vsyscall=none, except
1038          that it will also disable the helpful warning if a program
1039          tries to use a vsyscall.  With this option set to N, offending
1040          programs will just segfault, citing addresses of the form
1041          0xffffffffff600?00.
1042 
1043          This option is required by many programs built before 2013, and
1044          care should be used even with newer programs if set to N.
1045 
1046          Disabling this option saves about 7K of kernel size and
1047          possibly 4K of additional runtime pagetable memory.
1048 
1049 config TOSHIBA
1050         tristate "Toshiba Laptop support"
1051         depends on X86_32
1052         ---help---
1053           This adds a driver to safely access the System Management Mode of
1054           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1055           not work on models with a Phoenix BIOS. The System Management Mode
1056           is used to set the BIOS and power saving options on Toshiba portables.
1057 
1058           For information on utilities to make use of this driver see the
1059           Toshiba Linux utilities web site at:
1060           <http://www.buzzard.org.uk/toshiba/>.
1061 
1062           Say Y if you intend to run this kernel on a Toshiba portable.
1063           Say N otherwise.
1064 
1065 config I8K
1066         tristate "Dell laptop support"
1067         select HWMON
1068         ---help---
1069           This adds a driver to safely access the System Management Mode
1070           of the CPU on the Dell Inspiron 8000. The System Management Mode
1071           is used to read cpu temperature and cooling fan status and to
1072           control the fans on the I8K portables.
1073 
1074           This driver has been tested only on the Inspiron 8000 but it may
1075           also work with other Dell laptops. You can force loading on other
1076           models by passing the parameter `force=1' to the module. Use at
1077           your own risk.
1078 
1079           For information on utilities to make use of this driver see the
1080           I8K Linux utilities web site at:
1081           <http://people.debian.org/~dz/i8k/>
1082 
1083           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1084           Say N otherwise.
1085 
1086 config X86_REBOOTFIXUPS
1087         bool "Enable X86 board specific fixups for reboot"
1088         depends on X86_32
1089         ---help---
1090           This enables chipset and/or board specific fixups to be done
1091           in order to get reboot to work correctly. This is only needed on
1092           some combinations of hardware and BIOS. The symptom, for which
1093           this config is intended, is when reboot ends with a stalled/hung
1094           system.
1095 
1096           Currently, the only fixup is for the Geode machines using
1097           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1098 
1099           Say Y if you want to enable the fixup. Currently, it's safe to
1100           enable this option even if you don't need it.
1101           Say N otherwise.
1102 
1103 config MICROCODE
1104         tristate "CPU microcode loading support"
1105         depends on CPU_SUP_AMD || CPU_SUP_INTEL
1106         select FW_LOADER
1107         ---help---
1108 
1109           If you say Y here, you will be able to update the microcode on
1110           certain Intel and AMD processors. The Intel support is for the
1111           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1112           Xeon etc. The AMD support is for families 0x10 and later. You will
1113           obviously need the actual microcode binary data itself which is not
1114           shipped with the Linux kernel.
1115 
1116           This option selects the general module only, you need to select
1117           at least one vendor specific module as well.
1118 
1119           To compile this driver as a module, choose M here: the module
1120           will be called microcode.
1121 
1122 config MICROCODE_INTEL
1123         bool "Intel microcode loading support"
1124         depends on MICROCODE
1125         default MICROCODE
1126         select FW_LOADER
1127         ---help---
1128           This options enables microcode patch loading support for Intel
1129           processors.
1130 
1131           For the current Intel microcode data package go to
1132           <https://downloadcenter.intel.com> and search for
1133           'Linux Processor Microcode Data File'.
1134 
1135 config MICROCODE_AMD
1136         bool "AMD microcode loading support"
1137         depends on MICROCODE
1138         select FW_LOADER
1139         ---help---
1140           If you select this option, microcode patch loading support for AMD
1141           processors will be enabled.
1142 
1143 config MICROCODE_OLD_INTERFACE
1144         def_bool y
1145         depends on MICROCODE
1146 
1147 config MICROCODE_INTEL_EARLY
1148         def_bool n
1149 
1150 config MICROCODE_AMD_EARLY
1151         def_bool n
1152 
1153 config MICROCODE_EARLY
1154         bool "Early load microcode"
1155         depends on MICROCODE=y && BLK_DEV_INITRD
1156         select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1157         select MICROCODE_AMD_EARLY if MICROCODE_AMD
1158         default y
1159         help
1160           This option provides functionality to read additional microcode data
1161           at the beginning of initrd image. The data tells kernel to load
1162           microcode to CPU's as early as possible. No functional change if no
1163           microcode data is glued to the initrd, therefore it's safe to say Y.
1164 
1165 config X86_MSR
1166         tristate "/dev/cpu/*/msr - Model-specific register support"
1167         ---help---
1168           This device gives privileged processes access to the x86
1169           Model-Specific Registers (MSRs).  It is a character device with
1170           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1171           MSR accesses are directed to a specific CPU on multi-processor
1172           systems.
1173 
1174 config X86_CPUID
1175         tristate "/dev/cpu/*/cpuid - CPU information support"
1176         ---help---
1177           This device gives processes access to the x86 CPUID instruction to
1178           be executed on a specific processor.  It is a character device
1179           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1180           /dev/cpu/31/cpuid.
1181 
1182 choice
1183         prompt "High Memory Support"
1184         default HIGHMEM4G
1185         depends on X86_32
1186 
1187 config NOHIGHMEM
1188         bool "off"
1189         ---help---
1190           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1191           However, the address space of 32-bit x86 processors is only 4
1192           Gigabytes large. That means that, if you have a large amount of
1193           physical memory, not all of it can be "permanently mapped" by the
1194           kernel. The physical memory that's not permanently mapped is called
1195           "high memory".
1196 
1197           If you are compiling a kernel which will never run on a machine with
1198           more than 1 Gigabyte total physical RAM, answer "off" here (default
1199           choice and suitable for most users). This will result in a "3GB/1GB"
1200           split: 3GB are mapped so that each process sees a 3GB virtual memory
1201           space and the remaining part of the 4GB virtual memory space is used
1202           by the kernel to permanently map as much physical memory as
1203           possible.
1204 
1205           If the machine has between 1 and 4 Gigabytes physical RAM, then
1206           answer "4GB" here.
1207 
1208           If more than 4 Gigabytes is used then answer "64GB" here. This
1209           selection turns Intel PAE (Physical Address Extension) mode on.
1210           PAE implements 3-level paging on IA32 processors. PAE is fully
1211           supported by Linux, PAE mode is implemented on all recent Intel
1212           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1213           then the kernel will not boot on CPUs that don't support PAE!
1214 
1215           The actual amount of total physical memory will either be
1216           auto detected or can be forced by using a kernel command line option
1217           such as "mem=256M". (Try "man bootparam" or see the documentation of
1218           your boot loader (lilo or loadlin) about how to pass options to the
1219           kernel at boot time.)
1220 
1221           If unsure, say "off".
1222 
1223 config HIGHMEM4G
1224         bool "4GB"
1225         ---help---
1226           Select this if you have a 32-bit processor and between 1 and 4
1227           gigabytes of physical RAM.
1228 
1229 config HIGHMEM64G
1230         bool "64GB"
1231         depends on !M486
1232         select X86_PAE
1233         ---help---
1234           Select this if you have a 32-bit processor and more than 4
1235           gigabytes of physical RAM.
1236 
1237 endchoice
1238 
1239 choice
1240         prompt "Memory split" if EXPERT
1241         default VMSPLIT_3G
1242         depends on X86_32
1243         ---help---
1244           Select the desired split between kernel and user memory.
1245 
1246           If the address range available to the kernel is less than the
1247           physical memory installed, the remaining memory will be available
1248           as "high memory". Accessing high memory is a little more costly
1249           than low memory, as it needs to be mapped into the kernel first.
1250           Note that increasing the kernel address space limits the range
1251           available to user programs, making the address space there
1252           tighter.  Selecting anything other than the default 3G/1G split
1253           will also likely make your kernel incompatible with binary-only
1254           kernel modules.
1255 
1256           If you are not absolutely sure what you are doing, leave this
1257           option alone!
1258 
1259         config VMSPLIT_3G
1260                 bool "3G/1G user/kernel split"
1261         config VMSPLIT_3G_OPT
1262                 depends on !X86_PAE
1263                 bool "3G/1G user/kernel split (for full 1G low memory)"
1264         config VMSPLIT_2G
1265                 bool "2G/2G user/kernel split"
1266         config VMSPLIT_2G_OPT
1267                 depends on !X86_PAE
1268                 bool "2G/2G user/kernel split (for full 2G low memory)"
1269         config VMSPLIT_1G
1270                 bool "1G/3G user/kernel split"
1271 endchoice
1272 
1273 config PAGE_OFFSET
1274         hex
1275         default 0xB0000000 if VMSPLIT_3G_OPT
1276         default 0x80000000 if VMSPLIT_2G
1277         default 0x78000000 if VMSPLIT_2G_OPT
1278         default 0x40000000 if VMSPLIT_1G
1279         default 0xC0000000
1280         depends on X86_32
1281 
1282 config HIGHMEM
1283         def_bool y
1284         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1285 
1286 config X86_PAE
1287         bool "PAE (Physical Address Extension) Support"
1288         depends on X86_32 && !HIGHMEM4G
1289         ---help---
1290           PAE is required for NX support, and furthermore enables
1291           larger swapspace support for non-overcommit purposes. It
1292           has the cost of more pagetable lookup overhead, and also
1293           consumes more pagetable space per process.
1294 
1295 config ARCH_PHYS_ADDR_T_64BIT
1296         def_bool y
1297         depends on X86_64 || X86_PAE
1298 
1299 config ARCH_DMA_ADDR_T_64BIT
1300         def_bool y
1301         depends on X86_64 || HIGHMEM64G
1302 
1303 config DIRECT_GBPAGES
1304         bool "Enable 1GB pages for kernel pagetables" if EXPERT
1305         default y
1306         depends on X86_64
1307         ---help---
1308           Allow the kernel linear mapping to use 1GB pages on CPUs that
1309           support it. This can improve the kernel's performance a tiny bit by
1310           reducing TLB pressure. If in doubt, say "Y".
1311 
1312 # Common NUMA Features
1313 config NUMA
1314         bool "Numa Memory Allocation and Scheduler Support"
1315         depends on SMP
1316         depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1317         default y if X86_BIGSMP
1318         ---help---
1319           Enable NUMA (Non Uniform Memory Access) support.
1320 
1321           The kernel will try to allocate memory used by a CPU on the
1322           local memory controller of the CPU and add some more
1323           NUMA awareness to the kernel.
1324 
1325           For 64-bit this is recommended if the system is Intel Core i7
1326           (or later), AMD Opteron, or EM64T NUMA.
1327 
1328           For 32-bit this is only needed if you boot a 32-bit
1329           kernel on a 64-bit NUMA platform.
1330 
1331           Otherwise, you should say N.
1332 
1333 config AMD_NUMA
1334         def_bool y
1335         prompt "Old style AMD Opteron NUMA detection"
1336         depends on X86_64 && NUMA && PCI
1337         ---help---
1338           Enable AMD NUMA node topology detection.  You should say Y here if
1339           you have a multi processor AMD system. This uses an old method to
1340           read the NUMA configuration directly from the builtin Northbridge
1341           of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1342           which also takes priority if both are compiled in.
1343 
1344 config X86_64_ACPI_NUMA
1345         def_bool y
1346         prompt "ACPI NUMA detection"
1347         depends on X86_64 && NUMA && ACPI && PCI
1348         select ACPI_NUMA
1349         ---help---
1350           Enable ACPI SRAT based node topology detection.
1351 
1352 # Some NUMA nodes have memory ranges that span
1353 # other nodes.  Even though a pfn is valid and
1354 # between a node's start and end pfns, it may not
1355 # reside on that node.  See memmap_init_zone()
1356 # for details.
1357 config NODES_SPAN_OTHER_NODES
1358         def_bool y
1359         depends on X86_64_ACPI_NUMA
1360 
1361 config NUMA_EMU
1362         bool "NUMA emulation"
1363         depends on NUMA
1364         ---help---
1365           Enable NUMA emulation. A flat machine will be split
1366           into virtual nodes when booted with "numa=fake=N", where N is the
1367           number of nodes. This is only useful for debugging.
1368 
1369 config NODES_SHIFT
1370         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1371         range 1 10
1372         default "10" if MAXSMP
1373         default "6" if X86_64
1374         default "3"
1375         depends on NEED_MULTIPLE_NODES
1376         ---help---
1377           Specify the maximum number of NUMA Nodes available on the target
1378           system.  Increases memory reserved to accommodate various tables.
1379 
1380 config ARCH_HAVE_MEMORY_PRESENT
1381         def_bool y
1382         depends on X86_32 && DISCONTIGMEM
1383 
1384 config NEED_NODE_MEMMAP_SIZE
1385         def_bool y
1386         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1387 
1388 config ARCH_FLATMEM_ENABLE
1389         def_bool y
1390         depends on X86_32 && !NUMA
1391 
1392 config ARCH_DISCONTIGMEM_ENABLE
1393         def_bool y
1394         depends on NUMA && X86_32
1395 
1396 config ARCH_DISCONTIGMEM_DEFAULT
1397         def_bool y
1398         depends on NUMA && X86_32
1399 
1400 config ARCH_SPARSEMEM_ENABLE
1401         def_bool y
1402         depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1403         select SPARSEMEM_STATIC if X86_32
1404         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1405 
1406 config ARCH_SPARSEMEM_DEFAULT
1407         def_bool y
1408         depends on X86_64
1409 
1410 config ARCH_SELECT_MEMORY_MODEL
1411         def_bool y
1412         depends on ARCH_SPARSEMEM_ENABLE
1413 
1414 config ARCH_MEMORY_PROBE
1415         bool "Enable sysfs memory/probe interface"
1416         depends on X86_64 && MEMORY_HOTPLUG
1417         help
1418           This option enables a sysfs memory/probe interface for testing.
1419           See Documentation/memory-hotplug.txt for more information.
1420           If you are unsure how to answer this question, answer N.
1421 
1422 config ARCH_PROC_KCORE_TEXT
1423         def_bool y
1424         depends on X86_64 && PROC_KCORE
1425 
1426 config ILLEGAL_POINTER_VALUE
1427        hex
1428        default 0 if X86_32
1429        default 0xdead000000000000 if X86_64
1430 
1431 source "mm/Kconfig"
1432 
1433 config HIGHPTE
1434         bool "Allocate 3rd-level pagetables from highmem"
1435         depends on HIGHMEM
1436         ---help---
1437           The VM uses one page table entry for each page of physical memory.
1438           For systems with a lot of RAM, this can be wasteful of precious
1439           low memory.  Setting this option will put user-space page table
1440           entries in high memory.
1441 
1442 config X86_CHECK_BIOS_CORRUPTION
1443         bool "Check for low memory corruption"
1444         ---help---
1445           Periodically check for memory corruption in low memory, which
1446           is suspected to be caused by BIOS.  Even when enabled in the
1447           configuration, it is disabled at runtime.  Enable it by
1448           setting "memory_corruption_check=1" on the kernel command
1449           line.  By default it scans the low 64k of memory every 60
1450           seconds; see the memory_corruption_check_size and
1451           memory_corruption_check_period parameters in
1452           Documentation/kernel-parameters.txt to adjust this.
1453 
1454           When enabled with the default parameters, this option has
1455           almost no overhead, as it reserves a relatively small amount
1456           of memory and scans it infrequently.  It both detects corruption
1457           and prevents it from affecting the running system.
1458 
1459           It is, however, intended as a diagnostic tool; if repeatable
1460           BIOS-originated corruption always affects the same memory,
1461           you can use memmap= to prevent the kernel from using that
1462           memory.
1463 
1464 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1465         bool "Set the default setting of memory_corruption_check"
1466         depends on X86_CHECK_BIOS_CORRUPTION
1467         default y
1468         ---help---
1469           Set whether the default state of memory_corruption_check is
1470           on or off.
1471 
1472 config X86_RESERVE_LOW
1473         int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1474         default 64
1475         range 4 640
1476         ---help---
1477           Specify the amount of low memory to reserve for the BIOS.
1478 
1479           The first page contains BIOS data structures that the kernel
1480           must not use, so that page must always be reserved.
1481 
1482           By default we reserve the first 64K of physical RAM, as a
1483           number of BIOSes are known to corrupt that memory range
1484           during events such as suspend/resume or monitor cable
1485           insertion, so it must not be used by the kernel.
1486 
1487           You can set this to 4 if you are absolutely sure that you
1488           trust the BIOS to get all its memory reservations and usages
1489           right.  If you know your BIOS have problems beyond the
1490           default 64K area, you can set this to 640 to avoid using the
1491           entire low memory range.
1492 
1493           If you have doubts about the BIOS (e.g. suspend/resume does
1494           not work or there's kernel crashes after certain hardware
1495           hotplug events) then you might want to enable
1496           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1497           typical corruption patterns.
1498 
1499           Leave this to the default value of 64 if you are unsure.
1500 
1501 config MATH_EMULATION
1502         bool
1503         prompt "Math emulation" if X86_32
1504         ---help---
1505           Linux can emulate a math coprocessor (used for floating point
1506           operations) if you don't have one. 486DX and Pentium processors have
1507           a math coprocessor built in, 486SX and 386 do not, unless you added
1508           a 487DX or 387, respectively. (The messages during boot time can
1509           give you some hints here ["man dmesg"].) Everyone needs either a
1510           coprocessor or this emulation.
1511 
1512           If you don't have a math coprocessor, you need to say Y here; if you
1513           say Y here even though you have a coprocessor, the coprocessor will
1514           be used nevertheless. (This behavior can be changed with the kernel
1515           command line option "no387", which comes handy if your coprocessor
1516           is broken. Try "man bootparam" or see the documentation of your boot
1517           loader (lilo or loadlin) about how to pass options to the kernel at
1518           boot time.) This means that it is a good idea to say Y here if you
1519           intend to use this kernel on different machines.
1520 
1521           More information about the internals of the Linux math coprocessor
1522           emulation can be found in <file:arch/x86/math-emu/README>.
1523 
1524           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1525           kernel, it won't hurt.
1526 
1527 config MTRR
1528         def_bool y
1529         prompt "MTRR (Memory Type Range Register) support" if EXPERT
1530         ---help---
1531           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1532           the Memory Type Range Registers (MTRRs) may be used to control
1533           processor access to memory ranges. This is most useful if you have
1534           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1535           allows bus write transfers to be combined into a larger transfer
1536           before bursting over the PCI/AGP bus. This can increase performance
1537           of image write operations 2.5 times or more. Saying Y here creates a
1538           /proc/mtrr file which may be used to manipulate your processor's
1539           MTRRs. Typically the X server should use this.
1540 
1541           This code has a reasonably generic interface so that similar
1542           control registers on other processors can be easily supported
1543           as well:
1544 
1545           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1546           Registers (ARRs) which provide a similar functionality to MTRRs. For
1547           these, the ARRs are used to emulate the MTRRs.
1548           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1549           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1550           write-combining. All of these processors are supported by this code
1551           and it makes sense to say Y here if you have one of them.
1552 
1553           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1554           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1555           can lead to all sorts of problems, so it's good to say Y here.
1556 
1557           You can safely say Y even if your machine doesn't have MTRRs, you'll
1558           just add about 9 KB to your kernel.
1559 
1560           See <file:Documentation/x86/mtrr.txt> for more information.
1561 
1562 config MTRR_SANITIZER
1563         def_bool y
1564         prompt "MTRR cleanup support"
1565         depends on MTRR
1566         ---help---
1567           Convert MTRR layout from continuous to discrete, so X drivers can
1568           add writeback entries.
1569 
1570           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1571           The largest mtrr entry size for a continuous block can be set with
1572           mtrr_chunk_size.
1573 
1574           If unsure, say Y.
1575 
1576 config MTRR_SANITIZER_ENABLE_DEFAULT
1577         int "MTRR cleanup enable value (0-1)"
1578         range 0 1
1579         default "0"
1580         depends on MTRR_SANITIZER
1581         ---help---
1582           Enable mtrr cleanup default value
1583 
1584 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1585         int "MTRR cleanup spare reg num (0-7)"
1586         range 0 7
1587         default "1"
1588         depends on MTRR_SANITIZER
1589         ---help---
1590           mtrr cleanup spare entries default, it can be changed via
1591           mtrr_spare_reg_nr=N on the kernel command line.
1592 
1593 config X86_PAT
1594         def_bool y
1595         prompt "x86 PAT support" if EXPERT
1596         depends on MTRR
1597         ---help---
1598           Use PAT attributes to setup page level cache control.
1599 
1600           PATs are the modern equivalents of MTRRs and are much more
1601           flexible than MTRRs.
1602 
1603           Say N here if you see bootup problems (boot crash, boot hang,
1604           spontaneous reboots) or a non-working video driver.
1605 
1606           If unsure, say Y.
1607 
1608 config ARCH_USES_PG_UNCACHED
1609         def_bool y
1610         depends on X86_PAT
1611 
1612 config ARCH_RANDOM
1613         def_bool y
1614         prompt "x86 architectural random number generator" if EXPERT
1615         ---help---
1616           Enable the x86 architectural RDRAND instruction
1617           (Intel Bull Mountain technology) to generate random numbers.
1618           If supported, this is a high bandwidth, cryptographically
1619           secure hardware random number generator.
1620 
1621 config X86_SMAP
1622         def_bool y
1623         prompt "Supervisor Mode Access Prevention" if EXPERT
1624         ---help---
1625           Supervisor Mode Access Prevention (SMAP) is a security
1626           feature in newer Intel processors.  There is a small
1627           performance cost if this enabled and turned on; there is
1628           also a small increase in the kernel size if this is enabled.
1629 
1630           If unsure, say Y.
1631 
1632 config X86_INTEL_MPX
1633         prompt "Intel MPX (Memory Protection Extensions)"
1634         def_bool n
1635         depends on CPU_SUP_INTEL
1636         ---help---
1637           MPX provides hardware features that can be used in
1638           conjunction with compiler-instrumented code to check
1639           memory references.  It is designed to detect buffer
1640           overflow or underflow bugs.
1641 
1642           This option enables running applications which are
1643           instrumented or otherwise use MPX.  It does not use MPX
1644           itself inside the kernel or to protect the kernel
1645           against bad memory references.
1646 
1647           Enabling this option will make the kernel larger:
1648           ~8k of kernel text and 36 bytes of data on a 64-bit
1649           defconfig.  It adds a long to the 'mm_struct' which
1650           will increase the kernel memory overhead of each
1651           process and adds some branches to paths used during
1652           exec() and munmap().
1653 
1654           For details, see Documentation/x86/intel_mpx.txt
1655 
1656           If unsure, say N.
1657 
1658 config EFI
1659         bool "EFI runtime service support"
1660         depends on ACPI
1661         select UCS2_STRING
1662         select EFI_RUNTIME_WRAPPERS
1663         ---help---
1664           This enables the kernel to use EFI runtime services that are
1665           available (such as the EFI variable services).
1666 
1667           This option is only useful on systems that have EFI firmware.
1668           In addition, you should use the latest ELILO loader available
1669           at <http://elilo.sourceforge.net> in order to take advantage
1670           of EFI runtime services. However, even with this option, the
1671           resultant kernel should continue to boot on existing non-EFI
1672           platforms.
1673 
1674 config EFI_STUB
1675        bool "EFI stub support"
1676        depends on EFI && !X86_USE_3DNOW
1677        select RELOCATABLE
1678        ---help---
1679           This kernel feature allows a bzImage to be loaded directly
1680           by EFI firmware without the use of a bootloader.
1681 
1682           See Documentation/efi-stub.txt for more information.
1683 
1684 config EFI_MIXED
1685         bool "EFI mixed-mode support"
1686         depends on EFI_STUB && X86_64
1687         ---help---
1688            Enabling this feature allows a 64-bit kernel to be booted
1689            on a 32-bit firmware, provided that your CPU supports 64-bit
1690            mode.
1691 
1692            Note that it is not possible to boot a mixed-mode enabled
1693            kernel via the EFI boot stub - a bootloader that supports
1694            the EFI handover protocol must be used.
1695 
1696            If unsure, say N.
1697 
1698 config SECCOMP
1699         def_bool y
1700         prompt "Enable seccomp to safely compute untrusted bytecode"
1701         ---help---
1702           This kernel feature is useful for number crunching applications
1703           that may need to compute untrusted bytecode during their
1704           execution. By using pipes or other transports made available to
1705           the process as file descriptors supporting the read/write
1706           syscalls, it's possible to isolate those applications in
1707           their own address space using seccomp. Once seccomp is
1708           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1709           and the task is only allowed to execute a few safe syscalls
1710           defined by each seccomp mode.
1711 
1712           If unsure, say Y. Only embedded should say N here.
1713 
1714 source kernel/Kconfig.hz
1715 
1716 config KEXEC
1717         bool "kexec system call"
1718         ---help---
1719           kexec is a system call that implements the ability to shutdown your
1720           current kernel, and to start another kernel.  It is like a reboot
1721           but it is independent of the system firmware.   And like a reboot
1722           you can start any kernel with it, not just Linux.
1723 
1724           The name comes from the similarity to the exec system call.
1725 
1726           It is an ongoing process to be certain the hardware in a machine
1727           is properly shutdown, so do not be surprised if this code does not
1728           initially work for you.  As of this writing the exact hardware
1729           interface is strongly in flux, so no good recommendation can be
1730           made.
1731 
1732 config KEXEC_FILE
1733         bool "kexec file based system call"
1734         select BUILD_BIN2C
1735         depends on KEXEC
1736         depends on X86_64
1737         depends on CRYPTO=y
1738         depends on CRYPTO_SHA256=y
1739         ---help---
1740           This is new version of kexec system call. This system call is
1741           file based and takes file descriptors as system call argument
1742           for kernel and initramfs as opposed to list of segments as
1743           accepted by previous system call.
1744 
1745 config KEXEC_VERIFY_SIG
1746         bool "Verify kernel signature during kexec_file_load() syscall"
1747         depends on KEXEC_FILE
1748         ---help---
1749           This option makes kernel signature verification mandatory for
1750           kexec_file_load() syscall. If kernel is signature can not be
1751           verified, kexec_file_load() will fail.
1752 
1753           This option enforces signature verification at generic level.
1754           One needs to enable signature verification for type of kernel
1755           image being loaded to make sure it works. For example, enable
1756           bzImage signature verification option to be able to load and
1757           verify signatures of bzImage. Otherwise kernel loading will fail.
1758 
1759 config KEXEC_BZIMAGE_VERIFY_SIG
1760         bool "Enable bzImage signature verification support"
1761         depends on KEXEC_VERIFY_SIG
1762         depends on SIGNED_PE_FILE_VERIFICATION
1763         select SYSTEM_TRUSTED_KEYRING
1764         ---help---
1765           Enable bzImage signature verification support.
1766 
1767 config CRASH_DUMP
1768         bool "kernel crash dumps"
1769         depends on X86_64 || (X86_32 && HIGHMEM)
1770         ---help---
1771           Generate crash dump after being started by kexec.
1772           This should be normally only set in special crash dump kernels
1773           which are loaded in the main kernel with kexec-tools into
1774           a specially reserved region and then later executed after
1775           a crash by kdump/kexec. The crash dump kernel must be compiled
1776           to a memory address not used by the main kernel or BIOS using
1777           PHYSICAL_START, or it must be built as a relocatable image
1778           (CONFIG_RELOCATABLE=y).
1779           For more details see Documentation/kdump/kdump.txt
1780 
1781 config KEXEC_JUMP
1782         bool "kexec jump"
1783         depends on KEXEC && HIBERNATION
1784         ---help---
1785           Jump between original kernel and kexeced kernel and invoke
1786           code in physical address mode via KEXEC
1787 
1788 config PHYSICAL_START
1789         hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1790         default "0x1000000"
1791         ---help---
1792           This gives the physical address where the kernel is loaded.
1793 
1794           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1795           bzImage will decompress itself to above physical address and
1796           run from there. Otherwise, bzImage will run from the address where
1797           it has been loaded by the boot loader and will ignore above physical
1798           address.
1799 
1800           In normal kdump cases one does not have to set/change this option
1801           as now bzImage can be compiled as a completely relocatable image
1802           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1803           address. This option is mainly useful for the folks who don't want
1804           to use a bzImage for capturing the crash dump and want to use a
1805           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1806           to be specifically compiled to run from a specific memory area
1807           (normally a reserved region) and this option comes handy.
1808 
1809           So if you are using bzImage for capturing the crash dump,
1810           leave the value here unchanged to 0x1000000 and set
1811           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1812           for capturing the crash dump change this value to start of
1813           the reserved region.  In other words, it can be set based on
1814           the "X" value as specified in the "crashkernel=YM@XM"
1815           command line boot parameter passed to the panic-ed
1816           kernel. Please take a look at Documentation/kdump/kdump.txt
1817           for more details about crash dumps.
1818 
1819           Usage of bzImage for capturing the crash dump is recommended as
1820           one does not have to build two kernels. Same kernel can be used
1821           as production kernel and capture kernel. Above option should have
1822           gone away after relocatable bzImage support is introduced. But it
1823           is present because there are users out there who continue to use
1824           vmlinux for dump capture. This option should go away down the
1825           line.
1826 
1827           Don't change this unless you know what you are doing.
1828 
1829 config RELOCATABLE
1830         bool "Build a relocatable kernel"
1831         default y
1832         ---help---
1833           This builds a kernel image that retains relocation information
1834           so it can be loaded someplace besides the default 1MB.
1835           The relocations tend to make the kernel binary about 10% larger,
1836           but are discarded at runtime.
1837 
1838           One use is for the kexec on panic case where the recovery kernel
1839           must live at a different physical address than the primary
1840           kernel.
1841 
1842           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1843           it has been loaded at and the compile time physical address
1844           (CONFIG_PHYSICAL_START) is used as the minimum location.
1845 
1846 config RANDOMIZE_BASE
1847         bool "Randomize the address of the kernel image"
1848         depends on RELOCATABLE
1849         default n
1850         ---help---
1851            Randomizes the physical and virtual address at which the
1852            kernel image is decompressed, as a security feature that
1853            deters exploit attempts relying on knowledge of the location
1854            of kernel internals.
1855 
1856            Entropy is generated using the RDRAND instruction if it is
1857            supported. If RDTSC is supported, it is used as well. If
1858            neither RDRAND nor RDTSC are supported, then randomness is
1859            read from the i8254 timer.
1860 
1861            The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1862            and aligned according to PHYSICAL_ALIGN. Since the kernel is
1863            built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1864            minimum of 2MiB, only 10 bits of entropy is theoretically
1865            possible. At best, due to page table layouts, 64-bit can use
1866            9 bits of entropy and 32-bit uses 8 bits.
1867 
1868            If unsure, say N.
1869 
1870 config RANDOMIZE_BASE_MAX_OFFSET
1871         hex "Maximum kASLR offset allowed" if EXPERT
1872         depends on RANDOMIZE_BASE
1873         range 0x0 0x20000000 if X86_32
1874         default "0x20000000" if X86_32
1875         range 0x0 0x40000000 if X86_64
1876         default "0x40000000" if X86_64
1877         ---help---
1878           The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1879           memory is used to determine the maximal offset in bytes that will
1880           be applied to the kernel when kernel Address Space Layout
1881           Randomization (kASLR) is active. This must be a multiple of
1882           PHYSICAL_ALIGN.
1883 
1884           On 32-bit this is limited to 512MiB by page table layouts. The
1885           default is 512MiB.
1886 
1887           On 64-bit this is limited by how the kernel fixmap page table is
1888           positioned, so this cannot be larger than 1GiB currently. Without
1889           RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1890           and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1891           modules area will shrink to compensate, up to the current maximum
1892           1GiB to 1GiB split. The default is 1GiB.
1893 
1894           If unsure, leave at the default value.
1895 
1896 # Relocation on x86 needs some additional build support
1897 config X86_NEED_RELOCS
1898         def_bool y
1899         depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1900 
1901 config PHYSICAL_ALIGN
1902         hex "Alignment value to which kernel should be aligned"
1903         default "0x200000"
1904         range 0x2000 0x1000000 if X86_32
1905         range 0x200000 0x1000000 if X86_64
1906         ---help---
1907           This value puts the alignment restrictions on physical address
1908           where kernel is loaded and run from. Kernel is compiled for an
1909           address which meets above alignment restriction.
1910 
1911           If bootloader loads the kernel at a non-aligned address and
1912           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1913           address aligned to above value and run from there.
1914 
1915           If bootloader loads the kernel at a non-aligned address and
1916           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1917           load address and decompress itself to the address it has been
1918           compiled for and run from there. The address for which kernel is
1919           compiled already meets above alignment restrictions. Hence the
1920           end result is that kernel runs from a physical address meeting
1921           above alignment restrictions.
1922 
1923           On 32-bit this value must be a multiple of 0x2000. On 64-bit
1924           this value must be a multiple of 0x200000.
1925 
1926           Don't change this unless you know what you are doing.
1927 
1928 config HOTPLUG_CPU
1929         bool "Support for hot-pluggable CPUs"
1930         depends on SMP
1931         ---help---
1932           Say Y here to allow turning CPUs off and on. CPUs can be
1933           controlled through /sys/devices/system/cpu.
1934           ( Note: power management support will enable this option
1935             automatically on SMP systems. )
1936           Say N if you want to disable CPU hotplug.
1937 
1938 config BOOTPARAM_HOTPLUG_CPU0
1939         bool "Set default setting of cpu0_hotpluggable"
1940         default n
1941         depends on HOTPLUG_CPU
1942         ---help---
1943           Set whether default state of cpu0_hotpluggable is on or off.
1944 
1945           Say Y here to enable CPU0 hotplug by default. If this switch
1946           is turned on, there is no need to give cpu0_hotplug kernel
1947           parameter and the CPU0 hotplug feature is enabled by default.
1948 
1949           Please note: there are two known CPU0 dependencies if you want
1950           to enable the CPU0 hotplug feature either by this switch or by
1951           cpu0_hotplug kernel parameter.
1952 
1953           First, resume from hibernate or suspend always starts from CPU0.
1954           So hibernate and suspend are prevented if CPU0 is offline.
1955 
1956           Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1957           offline if any interrupt can not migrate out of CPU0. There may
1958           be other CPU0 dependencies.
1959 
1960           Please make sure the dependencies are under your control before
1961           you enable this feature.
1962 
1963           Say N if you don't want to enable CPU0 hotplug feature by default.
1964           You still can enable the CPU0 hotplug feature at boot by kernel
1965           parameter cpu0_hotplug.
1966 
1967 config DEBUG_HOTPLUG_CPU0
1968         def_bool n
1969         prompt "Debug CPU0 hotplug"
1970         depends on HOTPLUG_CPU
1971         ---help---
1972           Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1973           soon as possible and boots up userspace with CPU0 offlined. User
1974           can online CPU0 back after boot time.
1975 
1976           To debug CPU0 hotplug, you need to enable CPU0 offline/online
1977           feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1978           compilation or giving cpu0_hotplug kernel parameter at boot.
1979 
1980           If unsure, say N.
1981 
1982 config COMPAT_VDSO
1983         def_bool n
1984         prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1985         depends on X86_32 || IA32_EMULATION
1986         ---help---
1987           Certain buggy versions of glibc will crash if they are
1988           presented with a 32-bit vDSO that is not mapped at the address
1989           indicated in its segment table.
1990 
1991           The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1992           and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1993           49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
1994           the only released version with the bug, but OpenSUSE 9
1995           contains a buggy "glibc 2.3.2".
1996 
1997           The symptom of the bug is that everything crashes on startup, saying:
1998           dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1999 
2000           Saying Y here changes the default value of the vdso32 boot
2001           option from 1 to 0, which turns off the 32-bit vDSO entirely.
2002           This works around the glibc bug but hurts performance.
2003 
2004           If unsure, say N: if you are compiling your own kernel, you
2005           are unlikely to be using a buggy version of glibc.
2006 
2007 config CMDLINE_BOOL
2008         bool "Built-in kernel command line"
2009         ---help---
2010           Allow for specifying boot arguments to the kernel at
2011           build time.  On some systems (e.g. embedded ones), it is
2012           necessary or convenient to provide some or all of the
2013           kernel boot arguments with the kernel itself (that is,
2014           to not rely on the boot loader to provide them.)
2015 
2016           To compile command line arguments into the kernel,
2017           set this option to 'Y', then fill in the
2018           the boot arguments in CONFIG_CMDLINE.
2019 
2020           Systems with fully functional boot loaders (i.e. non-embedded)
2021           should leave this option set to 'N'.
2022 
2023 config CMDLINE
2024         string "Built-in kernel command string"
2025         depends on CMDLINE_BOOL
2026         default ""
2027         ---help---
2028           Enter arguments here that should be compiled into the kernel
2029           image and used at boot time.  If the boot loader provides a
2030           command line at boot time, it is appended to this string to
2031           form the full kernel command line, when the system boots.
2032 
2033           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2034           change this behavior.
2035 
2036           In most cases, the command line (whether built-in or provided
2037           by the boot loader) should specify the device for the root
2038           file system.
2039 
2040 config CMDLINE_OVERRIDE
2041         bool "Built-in command line overrides boot loader arguments"
2042         depends on CMDLINE_BOOL
2043         ---help---
2044           Set this option to 'Y' to have the kernel ignore the boot loader
2045           command line, and use ONLY the built-in command line.
2046 
2047           This is used to work around broken boot loaders.  This should
2048           be set to 'N' under normal conditions.
2049 
2050 source "kernel/livepatch/Kconfig"
2051 
2052 endmenu
2053 
2054 config ARCH_ENABLE_MEMORY_HOTPLUG
2055         def_bool y
2056         depends on X86_64 || (X86_32 && HIGHMEM)
2057 
2058 config ARCH_ENABLE_MEMORY_HOTREMOVE
2059         def_bool y
2060         depends on MEMORY_HOTPLUG
2061 
2062 config USE_PERCPU_NUMA_NODE_ID
2063         def_bool y
2064         depends on NUMA
2065 
2066 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2067         def_bool y
2068         depends on X86_64 || X86_PAE
2069 
2070 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2071         def_bool y
2072         depends on X86_64 && HUGETLB_PAGE && MIGRATION
2073 
2074 menu "Power management and ACPI options"
2075 
2076 config ARCH_HIBERNATION_HEADER
2077         def_bool y
2078         depends on X86_64 && HIBERNATION
2079 
2080 source "kernel/power/Kconfig"
2081 
2082 source "drivers/acpi/Kconfig"
2083 
2084 source "drivers/sfi/Kconfig"
2085 
2086 config X86_APM_BOOT
2087         def_bool y
2088         depends on APM
2089 
2090 menuconfig APM
2091         tristate "APM (Advanced Power Management) BIOS support"
2092         depends on X86_32 && PM_SLEEP
2093         ---help---
2094           APM is a BIOS specification for saving power using several different
2095           techniques. This is mostly useful for battery powered laptops with
2096           APM compliant BIOSes. If you say Y here, the system time will be
2097           reset after a RESUME operation, the /proc/apm device will provide
2098           battery status information, and user-space programs will receive
2099           notification of APM "events" (e.g. battery status change).
2100 
2101           If you select "Y" here, you can disable actual use of the APM
2102           BIOS by passing the "apm=off" option to the kernel at boot time.
2103 
2104           Note that the APM support is almost completely disabled for
2105           machines with more than one CPU.
2106 
2107           In order to use APM, you will need supporting software. For location
2108           and more information, read <file:Documentation/power/apm-acpi.txt>
2109           and the Battery Powered Linux mini-HOWTO, available from
2110           <http://www.tldp.org/docs.html#howto>.
2111 
2112           This driver does not spin down disk drives (see the hdparm(8)
2113           manpage ("man 8 hdparm") for that), and it doesn't turn off
2114           VESA-compliant "green" monitors.
2115 
2116           This driver does not support the TI 4000M TravelMate and the ACER
2117           486/DX4/75 because they don't have compliant BIOSes. Many "green"
2118           desktop machines also don't have compliant BIOSes, and this driver
2119           may cause those machines to panic during the boot phase.
2120 
2121           Generally, if you don't have a battery in your machine, there isn't
2122           much point in using this driver and you should say N. If you get
2123           random kernel OOPSes or reboots that don't seem to be related to
2124           anything, try disabling/enabling this option (or disabling/enabling
2125           APM in your BIOS).
2126 
2127           Some other things you should try when experiencing seemingly random,
2128           "weird" problems:
2129 
2130           1) make sure that you have enough swap space and that it is
2131           enabled.
2132           2) pass the "no-hlt" option to the kernel
2133           3) switch on floating point emulation in the kernel and pass
2134           the "no387" option to the kernel
2135           4) pass the "floppy=nodma" option to the kernel
2136           5) pass the "mem=4M" option to the kernel (thereby disabling
2137           all but the first 4 MB of RAM)
2138           6) make sure that the CPU is not over clocked.
2139           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2140           8) disable the cache from your BIOS settings
2141           9) install a fan for the video card or exchange video RAM
2142           10) install a better fan for the CPU
2143           11) exchange RAM chips
2144           12) exchange the motherboard.
2145 
2146           To compile this driver as a module, choose M here: the
2147           module will be called apm.
2148 
2149 if APM
2150 
2151 config APM_IGNORE_USER_SUSPEND
2152         bool "Ignore USER SUSPEND"
2153         ---help---
2154           This option will ignore USER SUSPEND requests. On machines with a
2155           compliant APM BIOS, you want to say N. However, on the NEC Versa M
2156           series notebooks, it is necessary to say Y because of a BIOS bug.
2157 
2158 config APM_DO_ENABLE
2159         bool "Enable PM at boot time"
2160         ---help---
2161           Enable APM features at boot time. From page 36 of the APM BIOS
2162           specification: "When disabled, the APM BIOS does not automatically
2163           power manage devices, enter the Standby State, enter the Suspend
2164           State, or take power saving steps in response to CPU Idle calls."
2165           This driver will make CPU Idle calls when Linux is idle (unless this
2166           feature is turned off -- see "Do CPU IDLE calls", below). This
2167           should always save battery power, but more complicated APM features
2168           will be dependent on your BIOS implementation. You may need to turn
2169           this option off if your computer hangs at boot time when using APM
2170           support, or if it beeps continuously instead of suspending. Turn
2171           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2172           T400CDT. This is off by default since most machines do fine without
2173           this feature.
2174 
2175 config APM_CPU_IDLE
2176         depends on CPU_IDLE
2177         bool "Make CPU Idle calls when idle"
2178         ---help---
2179           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2180           On some machines, this can activate improved power savings, such as
2181           a slowed CPU clock rate, when the machine is idle. These idle calls
2182           are made after the idle loop has run for some length of time (e.g.,
2183           333 mS). On some machines, this will cause a hang at boot time or
2184           whenever the CPU becomes idle. (On machines with more than one CPU,
2185           this option does nothing.)
2186 
2187 config APM_DISPLAY_BLANK
2188         bool "Enable console blanking using APM"
2189         ---help---
2190           Enable console blanking using the APM. Some laptops can use this to
2191           turn off the LCD backlight when the screen blanker of the Linux
2192           virtual console blanks the screen. Note that this is only used by
2193           the virtual console screen blanker, and won't turn off the backlight
2194           when using the X Window system. This also doesn't have anything to
2195           do with your VESA-compliant power-saving monitor. Further, this
2196           option doesn't work for all laptops -- it might not turn off your
2197           backlight at all, or it might print a lot of errors to the console,
2198           especially if you are using gpm.
2199 
2200 config APM_ALLOW_INTS
2201         bool "Allow interrupts during APM BIOS calls"
2202         ---help---
2203           Normally we disable external interrupts while we are making calls to
2204           the APM BIOS as a measure to lessen the effects of a badly behaving
2205           BIOS implementation.  The BIOS should reenable interrupts if it
2206           needs to.  Unfortunately, some BIOSes do not -- especially those in
2207           many of the newer IBM Thinkpads.  If you experience hangs when you
2208           suspend, try setting this to Y.  Otherwise, say N.
2209 
2210 endif # APM
2211 
2212 source "drivers/cpufreq/Kconfig"
2213 
2214 source "drivers/cpuidle/Kconfig"
2215 
2216 source "drivers/idle/Kconfig"
2217 
2218 endmenu
2219 
2220 
2221 menu "Bus options (PCI etc.)"
2222 
2223 config PCI
2224         bool "PCI support"
2225         default y
2226         ---help---
2227           Find out whether you have a PCI motherboard. PCI is the name of a
2228           bus system, i.e. the way the CPU talks to the other stuff inside
2229           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2230           VESA. If you have PCI, say Y, otherwise N.
2231 
2232 choice
2233         prompt "PCI access mode"
2234         depends on X86_32 && PCI
2235         default PCI_GOANY
2236         ---help---
2237           On PCI systems, the BIOS can be used to detect the PCI devices and
2238           determine their configuration. However, some old PCI motherboards
2239           have BIOS bugs and may crash if this is done. Also, some embedded
2240           PCI-based systems don't have any BIOS at all. Linux can also try to
2241           detect the PCI hardware directly without using the BIOS.
2242 
2243           With this option, you can specify how Linux should detect the
2244           PCI devices. If you choose "BIOS", the BIOS will be used,
2245           if you choose "Direct", the BIOS won't be used, and if you
2246           choose "MMConfig", then PCI Express MMCONFIG will be used.
2247           If you choose "Any", the kernel will try MMCONFIG, then the
2248           direct access method and falls back to the BIOS if that doesn't
2249           work. If unsure, go with the default, which is "Any".
2250 
2251 config PCI_GOBIOS
2252         bool "BIOS"
2253 
2254 config PCI_GOMMCONFIG
2255         bool "MMConfig"
2256 
2257 config PCI_GODIRECT
2258         bool "Direct"
2259 
2260 config PCI_GOOLPC
2261         bool "OLPC XO-1"
2262         depends on OLPC
2263 
2264 config PCI_GOANY
2265         bool "Any"
2266 
2267 endchoice
2268 
2269 config PCI_BIOS
2270         def_bool y
2271         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2272 
2273 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2274 config PCI_DIRECT
2275         def_bool y
2276         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2277 
2278 config PCI_MMCONFIG
2279         def_bool y
2280         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2281 
2282 config PCI_OLPC
2283         def_bool y
2284         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2285 
2286 config PCI_XEN
2287         def_bool y
2288         depends on PCI && XEN
2289         select SWIOTLB_XEN
2290 
2291 config PCI_DOMAINS
2292         def_bool y
2293         depends on PCI
2294 
2295 config PCI_MMCONFIG
2296         bool "Support mmconfig PCI config space access"
2297         depends on X86_64 && PCI && ACPI
2298 
2299 config PCI_CNB20LE_QUIRK
2300         bool "Read CNB20LE Host Bridge Windows" if EXPERT
2301         depends on PCI
2302         help
2303           Read the PCI windows out of the CNB20LE host bridge. This allows
2304           PCI hotplug to work on systems with the CNB20LE chipset which do
2305           not have ACPI.
2306 
2307           There's no public spec for this chipset, and this functionality
2308           is known to be incomplete.
2309 
2310           You should say N unless you know you need this.
2311 
2312 source "drivers/pci/pcie/Kconfig"
2313 
2314 source "drivers/pci/Kconfig"
2315 
2316 # x86_64 have no ISA slots, but can have ISA-style DMA.
2317 config ISA_DMA_API
2318         bool "ISA-style DMA support" if (X86_64 && EXPERT)
2319         default y
2320         help
2321           Enables ISA-style DMA support for devices requiring such controllers.
2322           If unsure, say Y.
2323 
2324 if X86_32
2325 
2326 config ISA
2327         bool "ISA support"
2328         ---help---
2329           Find out whether you have ISA slots on your motherboard.  ISA is the
2330           name of a bus system, i.e. the way the CPU talks to the other stuff
2331           inside your box.  Other bus systems are PCI, EISA, MicroChannel
2332           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2333           newer boards don't support it.  If you have ISA, say Y, otherwise N.
2334 
2335 config EISA
2336         bool "EISA support"
2337         depends on ISA
2338         ---help---
2339           The Extended Industry Standard Architecture (EISA) bus was
2340           developed as an open alternative to the IBM MicroChannel bus.
2341 
2342           The EISA bus provided some of the features of the IBM MicroChannel
2343           bus while maintaining backward compatibility with cards made for
2344           the older ISA bus.  The EISA bus saw limited use between 1988 and
2345           1995 when it was made obsolete by the PCI bus.
2346 
2347           Say Y here if you are building a kernel for an EISA-based machine.
2348 
2349           Otherwise, say N.
2350 
2351 source "drivers/eisa/Kconfig"
2352 
2353 config SCx200
2354         tristate "NatSemi SCx200 support"
2355         ---help---
2356           This provides basic support for National Semiconductor's
2357           (now AMD's) Geode processors.  The driver probes for the
2358           PCI-IDs of several on-chip devices, so its a good dependency
2359           for other scx200_* drivers.
2360 
2361           If compiled as a module, the driver is named scx200.
2362 
2363 config SCx200HR_TIMER
2364         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2365         depends on SCx200
2366         default y
2367         ---help---
2368           This driver provides a clocksource built upon the on-chip
2369           27MHz high-resolution timer.  Its also a workaround for
2370           NSC Geode SC-1100's buggy TSC, which loses time when the
2371           processor goes idle (as is done by the scheduler).  The
2372           other workaround is idle=poll boot option.
2373 
2374 config OLPC
2375         bool "One Laptop Per Child support"
2376         depends on !X86_PAE
2377         select GPIOLIB
2378         select OF
2379         select OF_PROMTREE
2380         select IRQ_DOMAIN
2381         ---help---
2382           Add support for detecting the unique features of the OLPC
2383           XO hardware.
2384 
2385 config OLPC_XO1_PM
2386         bool "OLPC XO-1 Power Management"
2387         depends on OLPC && MFD_CS5535 && PM_SLEEP
2388         select MFD_CORE
2389         ---help---
2390           Add support for poweroff and suspend of the OLPC XO-1 laptop.
2391 
2392 config OLPC_XO1_RTC
2393         bool "OLPC XO-1 Real Time Clock"
2394         depends on OLPC_XO1_PM && RTC_DRV_CMOS
2395         ---help---
2396           Add support for the XO-1 real time clock, which can be used as a
2397           programmable wakeup source.
2398 
2399 config OLPC_XO1_SCI
2400         bool "OLPC XO-1 SCI extras"
2401         depends on OLPC && OLPC_XO1_PM
2402         depends on INPUT=y
2403         select POWER_SUPPLY
2404         select GPIO_CS5535
2405         select MFD_CORE
2406         ---help---
2407           Add support for SCI-based features of the OLPC XO-1 laptop:
2408            - EC-driven system wakeups
2409            - Power button
2410            - Ebook switch
2411            - Lid switch
2412            - AC adapter status updates
2413            - Battery status updates
2414 
2415 config OLPC_XO15_SCI
2416         bool "OLPC XO-1.5 SCI extras"
2417         depends on OLPC && ACPI
2418         select POWER_SUPPLY
2419         ---help---
2420           Add support for SCI-based features of the OLPC XO-1.5 laptop:
2421            - EC-driven system wakeups
2422            - AC adapter status updates
2423            - Battery status updates
2424 
2425 config ALIX
2426         bool "PCEngines ALIX System Support (LED setup)"
2427         select GPIOLIB
2428         ---help---
2429           This option enables system support for the PCEngines ALIX.
2430           At present this just sets up LEDs for GPIO control on
2431           ALIX2/3/6 boards.  However, other system specific setup should
2432           get added here.
2433 
2434           Note: You must still enable the drivers for GPIO and LED support
2435           (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2436 
2437           Note: You have to set alix.force=1 for boards with Award BIOS.
2438 
2439 config NET5501
2440         bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2441         select GPIOLIB
2442         ---help---
2443           This option enables system support for the Soekris Engineering net5501.
2444 
2445 config GEOS
2446         bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2447         select GPIOLIB
2448         depends on DMI
2449         ---help---
2450           This option enables system support for the Traverse Technologies GEOS.
2451 
2452 config TS5500
2453         bool "Technologic Systems TS-5500 platform support"
2454         depends on MELAN
2455         select CHECK_SIGNATURE
2456         select NEW_LEDS
2457         select LEDS_CLASS
2458         ---help---
2459           This option enables system support for the Technologic Systems TS-5500.
2460 
2461 endif # X86_32
2462 
2463 config AMD_NB
2464         def_bool y
2465         depends on CPU_SUP_AMD && PCI
2466 
2467 source "drivers/pcmcia/Kconfig"
2468 
2469 source "drivers/pci/hotplug/Kconfig"
2470 
2471 config RAPIDIO
2472         tristate "RapidIO support"
2473         depends on PCI
2474         default n
2475         help
2476           If enabled this option will include drivers and the core
2477           infrastructure code to support RapidIO interconnect devices.
2478 
2479 source "drivers/rapidio/Kconfig"
2480 
2481 config X86_SYSFB
2482         bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2483         help
2484           Firmwares often provide initial graphics framebuffers so the BIOS,
2485           bootloader or kernel can show basic video-output during boot for
2486           user-guidance and debugging. Historically, x86 used the VESA BIOS
2487           Extensions and EFI-framebuffers for this, which are mostly limited
2488           to x86.
2489           This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2490           framebuffers so the new generic system-framebuffer drivers can be
2491           used on x86. If the framebuffer is not compatible with the generic
2492           modes, it is adverticed as fallback platform framebuffer so legacy
2493           drivers like efifb, vesafb and uvesafb can pick it up.
2494           If this option is not selected, all system framebuffers are always
2495           marked as fallback platform framebuffers as usual.
2496 
2497           Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2498           not be able to pick up generic system framebuffers if this option
2499           is selected. You are highly encouraged to enable simplefb as
2500           replacement if you select this option. simplefb can correctly deal
2501           with generic system framebuffers. But you should still keep vesafb
2502           and others enabled as fallback if a system framebuffer is
2503           incompatible with simplefb.
2504 
2505           If unsure, say Y.
2506 
2507 endmenu
2508 
2509 
2510 menu "Executable file formats / Emulations"
2511 
2512 source "fs/Kconfig.binfmt"
2513 
2514 config IA32_EMULATION
2515         bool "IA32 Emulation"
2516         depends on X86_64
2517         select BINFMT_ELF
2518         select COMPAT_BINFMT_ELF
2519         select HAVE_UID16
2520         ---help---
2521           Include code to run legacy 32-bit programs under a
2522           64-bit kernel. You should likely turn this on, unless you're
2523           100% sure that you don't have any 32-bit programs left.
2524 
2525 config IA32_AOUT
2526         tristate "IA32 a.out support"
2527         depends on IA32_EMULATION
2528         ---help---
2529           Support old a.out binaries in the 32bit emulation.
2530 
2531 config X86_X32
2532         bool "x32 ABI for 64-bit mode"
2533         depends on X86_64 && IA32_EMULATION
2534         ---help---
2535           Include code to run binaries for the x32 native 32-bit ABI
2536           for 64-bit processors.  An x32 process gets access to the
2537           full 64-bit register file and wide data path while leaving
2538           pointers at 32 bits for smaller memory footprint.
2539 
2540           You will need a recent binutils (2.22 or later) with
2541           elf32_x86_64 support enabled to compile a kernel with this
2542           option set.
2543 
2544 config COMPAT
2545         def_bool y
2546         depends on IA32_EMULATION || X86_X32
2547         select ARCH_WANT_OLD_COMPAT_IPC
2548 
2549 if COMPAT
2550 config COMPAT_FOR_U64_ALIGNMENT
2551         def_bool y
2552 
2553 config SYSVIPC_COMPAT
2554         def_bool y
2555         depends on SYSVIPC
2556 
2557 config KEYS_COMPAT
2558         def_bool y
2559         depends on KEYS
2560 endif
2561 
2562 endmenu
2563 
2564 
2565 config HAVE_ATOMIC_IOMAP
2566         def_bool y
2567         depends on X86_32
2568 
2569 config X86_DEV_DMA_OPS
2570         bool
2571         depends on X86_64 || STA2X11
2572 
2573 config X86_DMA_REMAP
2574         bool
2575         depends on STA2X11
2576 
2577 config PMC_ATOM
2578         def_bool y
2579         depends on PCI
2580 
2581 source "net/Kconfig"
2582 
2583 source "drivers/Kconfig"
2584 
2585 source "drivers/firmware/Kconfig"
2586 
2587 source "fs/Kconfig"
2588 
2589 source "arch/x86/Kconfig.debug"
2590 
2591 source "security/Kconfig"
2592 
2593 source "crypto/Kconfig"
2594 
2595 source "arch/x86/kvm/Kconfig"
2596 
2597 source "lib/Kconfig"

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