Version:  2.0.40 2.2.26 2.4.37 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6

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 
 13 config X86_64
 14         def_bool y
 15         depends on 64BIT
 16 
 17 ### Arch settings
 18 config X86
 19         def_bool y
 20         select ACPI_LEGACY_TABLES_LOOKUP        if ACPI
 21         select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
 22         select ANON_INODES
 23         select ARCH_CLOCKSOURCE_DATA
 24         select ARCH_DISCARD_MEMBLOCK
 25         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 26         select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 27         select ARCH_HAS_DEVMEM_IS_ALLOWED
 28         select ARCH_HAS_ELF_RANDOMIZE
 29         select ARCH_HAS_FAST_MULTIPLIER
 30         select ARCH_HAS_GCOV_PROFILE_ALL
 31         select ARCH_HAS_KCOV                    if X86_64
 32         select ARCH_HAS_PMEM_API                if X86_64
 33         select ARCH_HAS_MMIO_FLUSH
 34         select ARCH_HAS_SG_CHAIN
 35         select ARCH_HAS_UBSAN_SANITIZE_ALL
 36         select ARCH_HAVE_NMI_SAFE_CMPXCHG
 37         select ARCH_MIGHT_HAVE_ACPI_PDC         if ACPI
 38         select ARCH_MIGHT_HAVE_PC_PARPORT
 39         select ARCH_MIGHT_HAVE_PC_SERIO
 40         select ARCH_SUPPORTS_ATOMIC_RMW
 41         select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
 42         select ARCH_SUPPORTS_INT128             if X86_64
 43         select ARCH_SUPPORTS_NUMA_BALANCING     if X86_64
 44         select ARCH_USE_BUILTIN_BSWAP
 45         select ARCH_USE_CMPXCHG_LOCKREF         if X86_64
 46         select ARCH_USE_QUEUED_RWLOCKS
 47         select ARCH_USE_QUEUED_SPINLOCKS
 48         select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
 49         select ARCH_WANTS_DYNAMIC_TASK_STRUCT
 50         select ARCH_WANT_FRAME_POINTERS
 51         select ARCH_WANT_IPC_PARSE_VERSION      if X86_32
 52         select ARCH_WANT_OPTIONAL_GPIOLIB
 53         select BUILDTIME_EXTABLE_SORT
 54         select CLKEVT_I8253
 55         select CLKSRC_I8253                     if X86_32
 56         select CLOCKSOURCE_VALIDATE_LAST_CYCLE
 57         select CLOCKSOURCE_WATCHDOG
 58         select CLONE_BACKWARDS                  if X86_32
 59         select COMPAT_OLD_SIGACTION             if IA32_EMULATION
 60         select DCACHE_WORD_ACCESS
 61         select EDAC_ATOMIC_SCRUB
 62         select EDAC_SUPPORT
 63         select GENERIC_CLOCKEVENTS
 64         select GENERIC_CLOCKEVENTS_BROADCAST    if X86_64 || (X86_32 && X86_LOCAL_APIC)
 65         select GENERIC_CLOCKEVENTS_MIN_ADJUST
 66         select GENERIC_CMOS_UPDATE
 67         select GENERIC_CPU_AUTOPROBE
 68         select GENERIC_EARLY_IOREMAP
 69         select GENERIC_FIND_FIRST_BIT
 70         select GENERIC_IOMAP
 71         select GENERIC_IRQ_PROBE
 72         select GENERIC_IRQ_SHOW
 73         select GENERIC_PENDING_IRQ              if SMP
 74         select GENERIC_SMP_IDLE_THREAD
 75         select GENERIC_STRNCPY_FROM_USER
 76         select GENERIC_STRNLEN_USER
 77         select GENERIC_TIME_VSYSCALL
 78         select HAVE_ACPI_APEI                   if ACPI
 79         select HAVE_ACPI_APEI_NMI               if ACPI
 80         select HAVE_ALIGNED_STRUCT_PAGE         if SLUB
 81         select HAVE_AOUT                        if X86_32
 82         select HAVE_ARCH_AUDITSYSCALL
 83         select HAVE_ARCH_HUGE_VMAP              if X86_64 || X86_PAE
 84         select HAVE_ARCH_JUMP_LABEL
 85         select HAVE_ARCH_KASAN                  if X86_64 && SPARSEMEM_VMEMMAP
 86         select HAVE_ARCH_KGDB
 87         select HAVE_ARCH_KMEMCHECK
 88         select HAVE_ARCH_MMAP_RND_BITS          if MMU
 89         select HAVE_ARCH_MMAP_RND_COMPAT_BITS   if MMU && COMPAT
 90         select HAVE_ARCH_SECCOMP_FILTER
 91         select HAVE_ARCH_SOFT_DIRTY             if X86_64
 92         select HAVE_ARCH_TRACEHOOK
 93         select HAVE_ARCH_TRANSPARENT_HUGEPAGE
 94         select HAVE_BPF_JIT                     if X86_64
 95         select HAVE_CC_STACKPROTECTOR
 96         select HAVE_CMPXCHG_DOUBLE
 97         select HAVE_CMPXCHG_LOCAL
 98         select HAVE_CONTEXT_TRACKING            if X86_64
 99         select HAVE_COPY_THREAD_TLS
100         select HAVE_C_RECORDMCOUNT
101         select HAVE_DEBUG_KMEMLEAK
102         select HAVE_DEBUG_STACKOVERFLOW
103         select HAVE_DMA_API_DEBUG
104         select HAVE_DMA_CONTIGUOUS
105         select HAVE_DYNAMIC_FTRACE
106         select HAVE_DYNAMIC_FTRACE_WITH_REGS
107         select HAVE_EFFICIENT_UNALIGNED_ACCESS
108         select HAVE_FENTRY                      if X86_64
109         select HAVE_FTRACE_MCOUNT_RECORD
110         select HAVE_FUNCTION_GRAPH_FP_TEST
111         select HAVE_FUNCTION_GRAPH_TRACER
112         select HAVE_FUNCTION_TRACER
113         select HAVE_GENERIC_DMA_COHERENT        if X86_32
114         select HAVE_HW_BREAKPOINT
115         select HAVE_IDE
116         select HAVE_IOREMAP_PROT
117         select HAVE_IRQ_EXIT_ON_IRQ_STACK       if X86_64
118         select HAVE_IRQ_TIME_ACCOUNTING
119         select HAVE_KERNEL_BZIP2
120         select HAVE_KERNEL_GZIP
121         select HAVE_KERNEL_LZ4
122         select HAVE_KERNEL_LZMA
123         select HAVE_KERNEL_LZO
124         select HAVE_KERNEL_XZ
125         select HAVE_KPROBES
126         select HAVE_KPROBES_ON_FTRACE
127         select HAVE_KRETPROBES
128         select HAVE_KVM
129         select HAVE_LIVEPATCH                   if X86_64
130         select HAVE_MEMBLOCK
131         select HAVE_MEMBLOCK_NODE_MAP
132         select HAVE_MIXED_BREAKPOINTS_REGS
133         select HAVE_OPROFILE
134         select HAVE_OPTPROBES
135         select HAVE_PCSPKR_PLATFORM
136         select HAVE_PERF_EVENTS
137         select HAVE_PERF_EVENTS_NMI
138         select HAVE_PERF_REGS
139         select HAVE_PERF_USER_STACK_DUMP
140         select HAVE_REGS_AND_STACK_ACCESS_API
141         select HAVE_SYSCALL_TRACEPOINTS
142         select HAVE_UID16                       if X86_32 || IA32_EMULATION
143         select HAVE_UNSTABLE_SCHED_CLOCK
144         select HAVE_USER_RETURN_NOTIFIER
145         select IRQ_FORCED_THREADING
146         select MODULES_USE_ELF_RELA             if X86_64
147         select MODULES_USE_ELF_REL              if X86_32
148         select OLD_SIGACTION                    if X86_32
149         select OLD_SIGSUSPEND3                  if X86_32 || IA32_EMULATION
150         select PERF_EVENTS
151         select RTC_LIB
152         select SPARSE_IRQ
153         select SRCU
154         select SYSCTL_EXCEPTION_TRACE
155         select USER_STACKTRACE_SUPPORT
156         select VIRT_TO_BUS
157         select X86_DEV_DMA_OPS                  if X86_64
158         select X86_FEATURE_NAMES                if PROC_FS
159         select HAVE_STACK_VALIDATION            if X86_64
160         select ARCH_USES_HIGH_VMA_FLAGS         if X86_INTEL_MEMORY_PROTECTION_KEYS
161         select ARCH_HAS_PKEYS                   if X86_INTEL_MEMORY_PROTECTION_KEYS
162 
163 config INSTRUCTION_DECODER
164         def_bool y
165         depends on KPROBES || PERF_EVENTS || UPROBES
166 
167 config PERF_EVENTS_INTEL_UNCORE
168         def_bool y
169         depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
170 
171 config OUTPUT_FORMAT
172         string
173         default "elf32-i386" if X86_32
174         default "elf64-x86-64" if X86_64
175 
176 config ARCH_DEFCONFIG
177         string
178         default "arch/x86/configs/i386_defconfig" if X86_32
179         default "arch/x86/configs/x86_64_defconfig" if X86_64
180 
181 config LOCKDEP_SUPPORT
182         def_bool y
183 
184 config STACKTRACE_SUPPORT
185         def_bool y
186 
187 config MMU
188         def_bool y
189 
190 config ARCH_MMAP_RND_BITS_MIN
191         default 28 if 64BIT
192         default 8
193 
194 config ARCH_MMAP_RND_BITS_MAX
195         default 32 if 64BIT
196         default 16
197 
198 config ARCH_MMAP_RND_COMPAT_BITS_MIN
199         default 8
200 
201 config ARCH_MMAP_RND_COMPAT_BITS_MAX
202         default 16
203 
204 config SBUS
205         bool
206 
207 config NEED_DMA_MAP_STATE
208         def_bool y
209         depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
210 
211 config NEED_SG_DMA_LENGTH
212         def_bool y
213 
214 config GENERIC_ISA_DMA
215         def_bool y
216         depends on ISA_DMA_API
217 
218 config GENERIC_BUG
219         def_bool y
220         depends on BUG
221         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
222 
223 config GENERIC_BUG_RELATIVE_POINTERS
224         bool
225 
226 config GENERIC_HWEIGHT
227         def_bool y
228 
229 config ARCH_MAY_HAVE_PC_FDC
230         def_bool y
231         depends on ISA_DMA_API
232 
233 config RWSEM_XCHGADD_ALGORITHM
234         def_bool y
235 
236 config GENERIC_CALIBRATE_DELAY
237         def_bool y
238 
239 config ARCH_HAS_CPU_RELAX
240         def_bool y
241 
242 config ARCH_HAS_CACHE_LINE_SIZE
243         def_bool y
244 
245 config HAVE_SETUP_PER_CPU_AREA
246         def_bool y
247 
248 config NEED_PER_CPU_EMBED_FIRST_CHUNK
249         def_bool y
250 
251 config NEED_PER_CPU_PAGE_FIRST_CHUNK
252         def_bool y
253 
254 config ARCH_HIBERNATION_POSSIBLE
255         def_bool y
256 
257 config ARCH_SUSPEND_POSSIBLE
258         def_bool y
259 
260 config ARCH_WANT_HUGE_PMD_SHARE
261         def_bool y
262 
263 config ARCH_WANT_GENERAL_HUGETLB
264         def_bool y
265 
266 config ZONE_DMA32
267         def_bool y if X86_64
268 
269 config AUDIT_ARCH
270         def_bool y if X86_64
271 
272 config ARCH_SUPPORTS_OPTIMIZED_INLINING
273         def_bool y
274 
275 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
276         def_bool y
277 
278 config KASAN_SHADOW_OFFSET
279         hex
280         depends on KASAN
281         default 0xdffffc0000000000
282 
283 config HAVE_INTEL_TXT
284         def_bool y
285         depends on INTEL_IOMMU && ACPI
286 
287 config X86_32_SMP
288         def_bool y
289         depends on X86_32 && SMP
290 
291 config X86_64_SMP
292         def_bool y
293         depends on X86_64 && SMP
294 
295 config X86_32_LAZY_GS
296         def_bool y
297         depends on X86_32 && !CC_STACKPROTECTOR
298 
299 config ARCH_HWEIGHT_CFLAGS
300         string
301         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
302         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
303 
304 config ARCH_SUPPORTS_UPROBES
305         def_bool y
306 
307 config FIX_EARLYCON_MEM
308         def_bool y
309 
310 config DEBUG_RODATA
311         def_bool y
312 
313 config PGTABLE_LEVELS
314         int
315         default 4 if X86_64
316         default 3 if X86_PAE
317         default 2
318 
319 source "init/Kconfig"
320 source "kernel/Kconfig.freezer"
321 
322 menu "Processor type and features"
323 
324 config ZONE_DMA
325         bool "DMA memory allocation support" if EXPERT
326         default y
327         help
328           DMA memory allocation support allows devices with less than 32-bit
329           addressing to allocate within the first 16MB of address space.
330           Disable if no such devices will be used.
331 
332           If unsure, say Y.
333 
334 config SMP
335         bool "Symmetric multi-processing support"
336         ---help---
337           This enables support for systems with more than one CPU. If you have
338           a system with only one CPU, say N. If you have a system with more
339           than one CPU, say Y.
340 
341           If you say N here, the kernel will run on uni- and multiprocessor
342           machines, but will use only one CPU of a multiprocessor machine. If
343           you say Y here, the kernel will run on many, but not all,
344           uniprocessor machines. On a uniprocessor machine, the kernel
345           will run faster if you say N here.
346 
347           Note that if you say Y here and choose architecture "586" or
348           "Pentium" under "Processor family", the kernel will not work on 486
349           architectures. Similarly, multiprocessor kernels for the "PPro"
350           architecture may not work on all Pentium based boards.
351 
352           People using multiprocessor machines who say Y here should also say
353           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
354           Management" code will be disabled if you say Y here.
355 
356           See also <file:Documentation/x86/i386/IO-APIC.txt>,
357           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
358           <http://www.tldp.org/docs.html#howto>.
359 
360           If you don't know what to do here, say N.
361 
362 config X86_FEATURE_NAMES
363         bool "Processor feature human-readable names" if EMBEDDED
364         default y
365         ---help---
366           This option compiles in a table of x86 feature bits and corresponding
367           names.  This is required to support /proc/cpuinfo and a few kernel
368           messages.  You can disable this to save space, at the expense of
369           making those few kernel messages show numeric feature bits instead.
370 
371           If in doubt, say Y.
372 
373 config X86_FAST_FEATURE_TESTS
374         bool "Fast CPU feature tests" if EMBEDDED
375         default y
376         ---help---
377           Some fast-paths in the kernel depend on the capabilities of the CPU.
378           Say Y here for the kernel to patch in the appropriate code at runtime
379           based on the capabilities of the CPU. The infrastructure for patching
380           code at runtime takes up some additional space; space-constrained
381           embedded systems may wish to say N here to produce smaller, slightly
382           slower code.
383 
384 config X86_X2APIC
385         bool "Support x2apic"
386         depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
387         ---help---
388           This enables x2apic support on CPUs that have this feature.
389 
390           This allows 32-bit apic IDs (so it can support very large systems),
391           and accesses the local apic via MSRs not via mmio.
392 
393           If you don't know what to do here, say N.
394 
395 config X86_MPPARSE
396         bool "Enable MPS table" if ACPI || SFI
397         default y
398         depends on X86_LOCAL_APIC
399         ---help---
400           For old smp systems that do not have proper acpi support. Newer systems
401           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
402 
403 config X86_BIGSMP
404         bool "Support for big SMP systems with more than 8 CPUs"
405         depends on X86_32 && SMP
406         ---help---
407           This option is needed for the systems that have more than 8 CPUs
408 
409 config GOLDFISH
410        def_bool y
411        depends on X86_GOLDFISH
412 
413 if X86_32
414 config X86_EXTENDED_PLATFORM
415         bool "Support for extended (non-PC) x86 platforms"
416         default y
417         ---help---
418           If you disable this option then the kernel will only support
419           standard PC platforms. (which covers the vast majority of
420           systems out there.)
421 
422           If you enable this option then you'll be able to select support
423           for the following (non-PC) 32 bit x86 platforms:
424                 Goldfish (Android emulator)
425                 AMD Elan
426                 RDC R-321x SoC
427                 SGI 320/540 (Visual Workstation)
428                 STA2X11-based (e.g. Northville)
429                 Moorestown MID devices
430 
431           If you have one of these systems, or if you want to build a
432           generic distribution kernel, say Y here - otherwise say N.
433 endif
434 
435 if X86_64
436 config X86_EXTENDED_PLATFORM
437         bool "Support for extended (non-PC) x86 platforms"
438         default y
439         ---help---
440           If you disable this option then the kernel will only support
441           standard PC platforms. (which covers the vast majority of
442           systems out there.)
443 
444           If you enable this option then you'll be able to select support
445           for the following (non-PC) 64 bit x86 platforms:
446                 Numascale NumaChip
447                 ScaleMP vSMP
448                 SGI Ultraviolet
449 
450           If you have one of these systems, or if you want to build a
451           generic distribution kernel, say Y here - otherwise say N.
452 endif
453 # This is an alphabetically sorted list of 64 bit extended platforms
454 # Please maintain the alphabetic order if and when there are additions
455 config X86_NUMACHIP
456         bool "Numascale NumaChip"
457         depends on X86_64
458         depends on X86_EXTENDED_PLATFORM
459         depends on NUMA
460         depends on SMP
461         depends on X86_X2APIC
462         depends on PCI_MMCONFIG
463         ---help---
464           Adds support for Numascale NumaChip large-SMP systems. Needed to
465           enable more than ~168 cores.
466           If you don't have one of these, you should say N here.
467 
468 config X86_VSMP
469         bool "ScaleMP vSMP"
470         select HYPERVISOR_GUEST
471         select PARAVIRT
472         depends on X86_64 && PCI
473         depends on X86_EXTENDED_PLATFORM
474         depends on SMP
475         ---help---
476           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
477           supposed to run on these EM64T-based machines.  Only choose this option
478           if you have one of these machines.
479 
480 config X86_UV
481         bool "SGI Ultraviolet"
482         depends on X86_64
483         depends on X86_EXTENDED_PLATFORM
484         depends on NUMA
485         depends on EFI
486         depends on X86_X2APIC
487         depends on PCI
488         ---help---
489           This option is needed in order to support SGI Ultraviolet systems.
490           If you don't have one of these, you should say N here.
491 
492 # Following is an alphabetically sorted list of 32 bit extended platforms
493 # Please maintain the alphabetic order if and when there are additions
494 
495 config X86_GOLDFISH
496        bool "Goldfish (Virtual Platform)"
497        depends on X86_EXTENDED_PLATFORM
498        ---help---
499          Enable support for the Goldfish virtual platform used primarily
500          for Android development. Unless you are building for the Android
501          Goldfish emulator say N here.
502 
503 config X86_INTEL_CE
504         bool "CE4100 TV platform"
505         depends on PCI
506         depends on PCI_GODIRECT
507         depends on X86_IO_APIC
508         depends on X86_32
509         depends on X86_EXTENDED_PLATFORM
510         select X86_REBOOTFIXUPS
511         select OF
512         select OF_EARLY_FLATTREE
513         ---help---
514           Select for the Intel CE media processor (CE4100) SOC.
515           This option compiles in support for the CE4100 SOC for settop
516           boxes and media devices.
517 
518 config X86_INTEL_MID
519         bool "Intel MID platform support"
520         depends on X86_EXTENDED_PLATFORM
521         depends on X86_PLATFORM_DEVICES
522         depends on PCI
523         depends on X86_64 || (PCI_GOANY && X86_32)
524         depends on X86_IO_APIC
525         select SFI
526         select I2C
527         select DW_APB_TIMER
528         select APB_TIMER
529         select INTEL_SCU_IPC
530         select MFD_INTEL_MSIC
531         ---help---
532           Select to build a kernel capable of supporting Intel MID (Mobile
533           Internet Device) platform systems which do not have the PCI legacy
534           interfaces. If you are building for a PC class system say N here.
535 
536           Intel MID platforms are based on an Intel processor and chipset which
537           consume less power than most of the x86 derivatives.
538 
539 config X86_INTEL_QUARK
540         bool "Intel Quark platform support"
541         depends on X86_32
542         depends on X86_EXTENDED_PLATFORM
543         depends on X86_PLATFORM_DEVICES
544         depends on X86_TSC
545         depends on PCI
546         depends on PCI_GOANY
547         depends on X86_IO_APIC
548         select IOSF_MBI
549         select INTEL_IMR
550         select COMMON_CLK
551         ---help---
552           Select to include support for Quark X1000 SoC.
553           Say Y here if you have a Quark based system such as the Arduino
554           compatible Intel Galileo.
555 
556 config X86_INTEL_LPSS
557         bool "Intel Low Power Subsystem Support"
558         depends on X86 && ACPI
559         select COMMON_CLK
560         select PINCTRL
561         select IOSF_MBI
562         ---help---
563           Select to build support for Intel Low Power Subsystem such as
564           found on Intel Lynxpoint PCH. Selecting this option enables
565           things like clock tree (common clock framework) and pincontrol
566           which are needed by the LPSS peripheral drivers.
567 
568 config X86_AMD_PLATFORM_DEVICE
569         bool "AMD ACPI2Platform devices support"
570         depends on ACPI
571         select COMMON_CLK
572         select PINCTRL
573         ---help---
574           Select to interpret AMD specific ACPI device to platform device
575           such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
576           I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
577           implemented under PINCTRL subsystem.
578 
579 config IOSF_MBI
580         tristate "Intel SoC IOSF Sideband support for SoC platforms"
581         depends on PCI
582         ---help---
583           This option enables sideband register access support for Intel SoC
584           platforms. On these platforms the IOSF sideband is used in lieu of
585           MSR's for some register accesses, mostly but not limited to thermal
586           and power. Drivers may query the availability of this device to
587           determine if they need the sideband in order to work on these
588           platforms. The sideband is available on the following SoC products.
589           This list is not meant to be exclusive.
590            - BayTrail
591            - Braswell
592            - Quark
593 
594           You should say Y if you are running a kernel on one of these SoC's.
595 
596 config IOSF_MBI_DEBUG
597         bool "Enable IOSF sideband access through debugfs"
598         depends on IOSF_MBI && DEBUG_FS
599         ---help---
600           Select this option to expose the IOSF sideband access registers (MCR,
601           MDR, MCRX) through debugfs to write and read register information from
602           different units on the SoC. This is most useful for obtaining device
603           state information for debug and analysis. As this is a general access
604           mechanism, users of this option would have specific knowledge of the
605           device they want to access.
606 
607           If you don't require the option or are in doubt, say N.
608 
609 config X86_RDC321X
610         bool "RDC R-321x SoC"
611         depends on X86_32
612         depends on X86_EXTENDED_PLATFORM
613         select M486
614         select X86_REBOOTFIXUPS
615         ---help---
616           This option is needed for RDC R-321x system-on-chip, also known
617           as R-8610-(G).
618           If you don't have one of these chips, you should say N here.
619 
620 config X86_32_NON_STANDARD
621         bool "Support non-standard 32-bit SMP architectures"
622         depends on X86_32 && SMP
623         depends on X86_EXTENDED_PLATFORM
624         ---help---
625           This option compiles in the bigsmp and STA2X11 default
626           subarchitectures.  It is intended for a generic binary
627           kernel. If you select them all, kernel will probe it one by
628           one and will fallback to default.
629 
630 # Alphabetically sorted list of Non standard 32 bit platforms
631 
632 config X86_SUPPORTS_MEMORY_FAILURE
633         def_bool y
634         # MCE code calls memory_failure():
635         depends on X86_MCE
636         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
637         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
638         depends on X86_64 || !SPARSEMEM
639         select ARCH_SUPPORTS_MEMORY_FAILURE
640 
641 config STA2X11
642         bool "STA2X11 Companion Chip Support"
643         depends on X86_32_NON_STANDARD && PCI
644         select X86_DEV_DMA_OPS
645         select X86_DMA_REMAP
646         select SWIOTLB
647         select MFD_STA2X11
648         select ARCH_REQUIRE_GPIOLIB
649         default n
650         ---help---
651           This adds support for boards based on the STA2X11 IO-Hub,
652           a.k.a. "ConneXt". The chip is used in place of the standard
653           PC chipset, so all "standard" peripherals are missing. If this
654           option is selected the kernel will still be able to boot on
655           standard PC machines.
656 
657 config X86_32_IRIS
658         tristate "Eurobraille/Iris poweroff module"
659         depends on X86_32
660         ---help---
661           The Iris machines from EuroBraille do not have APM or ACPI support
662           to shut themselves down properly.  A special I/O sequence is
663           needed to do so, which is what this module does at
664           kernel shutdown.
665 
666           This is only for Iris machines from EuroBraille.
667 
668           If unused, say N.
669 
670 config SCHED_OMIT_FRAME_POINTER
671         def_bool y
672         prompt "Single-depth WCHAN output"
673         depends on X86
674         ---help---
675           Calculate simpler /proc/<PID>/wchan values. If this option
676           is disabled then wchan values will recurse back to the
677           caller function. This provides more accurate wchan values,
678           at the expense of slightly more scheduling overhead.
679 
680           If in doubt, say "Y".
681 
682 menuconfig HYPERVISOR_GUEST
683         bool "Linux guest support"
684         ---help---
685           Say Y here to enable options for running Linux under various hyper-
686           visors. This option enables basic hypervisor detection and platform
687           setup.
688 
689           If you say N, all options in this submenu will be skipped and
690           disabled, and Linux guest support won't be built in.
691 
692 if HYPERVISOR_GUEST
693 
694 config PARAVIRT
695         bool "Enable paravirtualization code"
696         ---help---
697           This changes the kernel so it can modify itself when it is run
698           under a hypervisor, potentially improving performance significantly
699           over full virtualization.  However, when run without a hypervisor
700           the kernel is theoretically slower and slightly larger.
701 
702 config PARAVIRT_DEBUG
703         bool "paravirt-ops debugging"
704         depends on PARAVIRT && DEBUG_KERNEL
705         ---help---
706           Enable to debug paravirt_ops internals.  Specifically, BUG if
707           a paravirt_op is missing when it is called.
708 
709 config PARAVIRT_SPINLOCKS
710         bool "Paravirtualization layer for spinlocks"
711         depends on PARAVIRT && SMP
712         select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
713         ---help---
714           Paravirtualized spinlocks allow a pvops backend to replace the
715           spinlock implementation with something virtualization-friendly
716           (for example, block the virtual CPU rather than spinning).
717 
718           It has a minimal impact on native kernels and gives a nice performance
719           benefit on paravirtualized KVM / Xen kernels.
720 
721           If you are unsure how to answer this question, answer Y.
722 
723 config QUEUED_LOCK_STAT
724         bool "Paravirt queued spinlock statistics"
725         depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
726         ---help---
727           Enable the collection of statistical data on the slowpath
728           behavior of paravirtualized queued spinlocks and report
729           them on debugfs.
730 
731 source "arch/x86/xen/Kconfig"
732 
733 config KVM_GUEST
734         bool "KVM Guest support (including kvmclock)"
735         depends on PARAVIRT
736         select PARAVIRT_CLOCK
737         default y
738         ---help---
739           This option enables various optimizations for running under the KVM
740           hypervisor. It includes a paravirtualized clock, so that instead
741           of relying on a PIT (or probably other) emulation by the
742           underlying device model, the host provides the guest with
743           timing infrastructure such as time of day, and system time
744 
745 config KVM_DEBUG_FS
746         bool "Enable debug information for KVM Guests in debugfs"
747         depends on KVM_GUEST && DEBUG_FS
748         default n
749         ---help---
750           This option enables collection of various statistics for KVM guest.
751           Statistics are displayed in debugfs filesystem. Enabling this option
752           may incur significant overhead.
753 
754 source "arch/x86/lguest/Kconfig"
755 
756 config PARAVIRT_TIME_ACCOUNTING
757         bool "Paravirtual steal time accounting"
758         depends on PARAVIRT
759         default n
760         ---help---
761           Select this option to enable fine granularity task steal time
762           accounting. Time spent executing other tasks in parallel with
763           the current vCPU is discounted from the vCPU power. To account for
764           that, there can be a small performance impact.
765 
766           If in doubt, say N here.
767 
768 config PARAVIRT_CLOCK
769         bool
770 
771 endif #HYPERVISOR_GUEST
772 
773 config NO_BOOTMEM
774         def_bool y
775 
776 source "arch/x86/Kconfig.cpu"
777 
778 config HPET_TIMER
779         def_bool X86_64
780         prompt "HPET Timer Support" if X86_32
781         ---help---
782           Use the IA-PC HPET (High Precision Event Timer) to manage
783           time in preference to the PIT and RTC, if a HPET is
784           present.
785           HPET is the next generation timer replacing legacy 8254s.
786           The HPET provides a stable time base on SMP
787           systems, unlike the TSC, but it is more expensive to access,
788           as it is off-chip.  The interface used is documented
789           in the HPET spec, revision 1.
790 
791           You can safely choose Y here.  However, HPET will only be
792           activated if the platform and the BIOS support this feature.
793           Otherwise the 8254 will be used for timing services.
794 
795           Choose N to continue using the legacy 8254 timer.
796 
797 config HPET_EMULATE_RTC
798         def_bool y
799         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
800 
801 config APB_TIMER
802        def_bool y if X86_INTEL_MID
803        prompt "Intel MID APB Timer Support" if X86_INTEL_MID
804        select DW_APB_TIMER
805        depends on X86_INTEL_MID && SFI
806        help
807          APB timer is the replacement for 8254, HPET on X86 MID platforms.
808          The APBT provides a stable time base on SMP
809          systems, unlike the TSC, but it is more expensive to access,
810          as it is off-chip. APB timers are always running regardless of CPU
811          C states, they are used as per CPU clockevent device when possible.
812 
813 # Mark as expert because too many people got it wrong.
814 # The code disables itself when not needed.
815 config DMI
816         default y
817         select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
818         bool "Enable DMI scanning" if EXPERT
819         ---help---
820           Enabled scanning of DMI to identify machine quirks. Say Y
821           here unless you have verified that your setup is not
822           affected by entries in the DMI blacklist. Required by PNP
823           BIOS code.
824 
825 config GART_IOMMU
826         bool "Old AMD GART IOMMU support"
827         select SWIOTLB
828         depends on X86_64 && PCI && AMD_NB
829         ---help---
830           Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
831           GART based hardware IOMMUs.
832 
833           The GART supports full DMA access for devices with 32-bit access
834           limitations, on systems with more than 3 GB. This is usually needed
835           for USB, sound, many IDE/SATA chipsets and some other devices.
836 
837           Newer systems typically have a modern AMD IOMMU, supported via
838           the CONFIG_AMD_IOMMU=y config option.
839 
840           In normal configurations this driver is only active when needed:
841           there's more than 3 GB of memory and the system contains a
842           32-bit limited device.
843 
844           If unsure, say Y.
845 
846 config CALGARY_IOMMU
847         bool "IBM Calgary IOMMU support"
848         select SWIOTLB
849         depends on X86_64 && PCI
850         ---help---
851           Support for hardware IOMMUs in IBM's xSeries x366 and x460
852           systems. Needed to run systems with more than 3GB of memory
853           properly with 32-bit PCI devices that do not support DAC
854           (Double Address Cycle). Calgary also supports bus level
855           isolation, where all DMAs pass through the IOMMU.  This
856           prevents them from going anywhere except their intended
857           destination. This catches hard-to-find kernel bugs and
858           mis-behaving drivers and devices that do not use the DMA-API
859           properly to set up their DMA buffers.  The IOMMU can be
860           turned off at boot time with the iommu=off parameter.
861           Normally the kernel will make the right choice by itself.
862           If unsure, say Y.
863 
864 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
865         def_bool y
866         prompt "Should Calgary be enabled by default?"
867         depends on CALGARY_IOMMU
868         ---help---
869           Should Calgary be enabled by default? if you choose 'y', Calgary
870           will be used (if it exists). If you choose 'n', Calgary will not be
871           used even if it exists. If you choose 'n' and would like to use
872           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
873           If unsure, say Y.
874 
875 # need this always selected by IOMMU for the VIA workaround
876 config SWIOTLB
877         def_bool y if X86_64
878         ---help---
879           Support for software bounce buffers used on x86-64 systems
880           which don't have a hardware IOMMU. Using this PCI devices
881           which can only access 32-bits of memory can be used on systems
882           with more than 3 GB of memory.
883           If unsure, say Y.
884 
885 config IOMMU_HELPER
886         def_bool y
887         depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
888 
889 config MAXSMP
890         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
891         depends on X86_64 && SMP && DEBUG_KERNEL
892         select CPUMASK_OFFSTACK
893         ---help---
894           Enable maximum number of CPUS and NUMA Nodes for this architecture.
895           If unsure, say N.
896 
897 config NR_CPUS
898         int "Maximum number of CPUs" if SMP && !MAXSMP
899         range 2 8 if SMP && X86_32 && !X86_BIGSMP
900         range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
901         range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
902         default "1" if !SMP
903         default "8192" if MAXSMP
904         default "32" if SMP && X86_BIGSMP
905         default "8" if SMP && X86_32
906         default "64" if SMP
907         ---help---
908           This allows you to specify the maximum number of CPUs which this
909           kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
910           supported value is 8192, otherwise the maximum value is 512.  The
911           minimum value which makes sense is 2.
912 
913           This is purely to save memory - each supported CPU adds
914           approximately eight kilobytes to the kernel image.
915 
916 config SCHED_SMT
917         bool "SMT (Hyperthreading) scheduler support"
918         depends on SMP
919         ---help---
920           SMT scheduler support improves the CPU scheduler's decision making
921           when dealing with Intel Pentium 4 chips with HyperThreading at a
922           cost of slightly increased overhead in some places. If unsure say
923           N here.
924 
925 config SCHED_MC
926         def_bool y
927         prompt "Multi-core scheduler support"
928         depends on SMP
929         ---help---
930           Multi-core scheduler support improves the CPU scheduler's decision
931           making when dealing with multi-core CPU chips at a cost of slightly
932           increased overhead in some places. If unsure say N here.
933 
934 source "kernel/Kconfig.preempt"
935 
936 config UP_LATE_INIT
937        def_bool y
938        depends on !SMP && X86_LOCAL_APIC
939 
940 config X86_UP_APIC
941         bool "Local APIC support on uniprocessors" if !PCI_MSI
942         default PCI_MSI
943         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
944         ---help---
945           A local APIC (Advanced Programmable Interrupt Controller) is an
946           integrated interrupt controller in the CPU. If you have a single-CPU
947           system which has a processor with a local APIC, you can say Y here to
948           enable and use it. If you say Y here even though your machine doesn't
949           have a local APIC, then the kernel will still run with no slowdown at
950           all. The local APIC supports CPU-generated self-interrupts (timer,
951           performance counters), and the NMI watchdog which detects hard
952           lockups.
953 
954 config X86_UP_IOAPIC
955         bool "IO-APIC support on uniprocessors"
956         depends on X86_UP_APIC
957         ---help---
958           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
959           SMP-capable replacement for PC-style interrupt controllers. Most
960           SMP systems and many recent uniprocessor systems have one.
961 
962           If you have a single-CPU system with an IO-APIC, you can say Y here
963           to use it. If you say Y here even though your machine doesn't have
964           an IO-APIC, then the kernel will still run with no slowdown at all.
965 
966 config X86_LOCAL_APIC
967         def_bool y
968         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
969         select IRQ_DOMAIN_HIERARCHY
970         select PCI_MSI_IRQ_DOMAIN if PCI_MSI
971 
972 config X86_IO_APIC
973         def_bool y
974         depends on X86_LOCAL_APIC || X86_UP_IOAPIC
975 
976 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
977         bool "Reroute for broken boot IRQs"
978         depends on X86_IO_APIC
979         ---help---
980           This option enables a workaround that fixes a source of
981           spurious interrupts. This is recommended when threaded
982           interrupt handling is used on systems where the generation of
983           superfluous "boot interrupts" cannot be disabled.
984 
985           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
986           entry in the chipset's IO-APIC is masked (as, e.g. the RT
987           kernel does during interrupt handling). On chipsets where this
988           boot IRQ generation cannot be disabled, this workaround keeps
989           the original IRQ line masked so that only the equivalent "boot
990           IRQ" is delivered to the CPUs. The workaround also tells the
991           kernel to set up the IRQ handler on the boot IRQ line. In this
992           way only one interrupt is delivered to the kernel. Otherwise
993           the spurious second interrupt may cause the kernel to bring
994           down (vital) interrupt lines.
995 
996           Only affects "broken" chipsets. Interrupt sharing may be
997           increased on these systems.
998 
999 config X86_MCE
1000         bool "Machine Check / overheating reporting"
1001         select GENERIC_ALLOCATOR
1002         default y
1003         ---help---
1004           Machine Check support allows the processor to notify the
1005           kernel if it detects a problem (e.g. overheating, data corruption).
1006           The action the kernel takes depends on the severity of the problem,
1007           ranging from warning messages to halting the machine.
1008 
1009 config X86_MCE_INTEL
1010         def_bool y
1011         prompt "Intel MCE features"
1012         depends on X86_MCE && X86_LOCAL_APIC
1013         ---help---
1014            Additional support for intel specific MCE features such as
1015            the thermal monitor.
1016 
1017 config X86_MCE_AMD
1018         def_bool y
1019         prompt "AMD MCE features"
1020         depends on X86_MCE && X86_LOCAL_APIC
1021         ---help---
1022            Additional support for AMD specific MCE features such as
1023            the DRAM Error Threshold.
1024 
1025 config X86_ANCIENT_MCE
1026         bool "Support for old Pentium 5 / WinChip machine checks"
1027         depends on X86_32 && X86_MCE
1028         ---help---
1029           Include support for machine check handling on old Pentium 5 or WinChip
1030           systems. These typically need to be enabled explicitly on the command
1031           line.
1032 
1033 config X86_MCE_THRESHOLD
1034         depends on X86_MCE_AMD || X86_MCE_INTEL
1035         def_bool y
1036 
1037 config X86_MCE_INJECT
1038         depends on X86_MCE
1039         tristate "Machine check injector support"
1040         ---help---
1041           Provide support for injecting machine checks for testing purposes.
1042           If you don't know what a machine check is and you don't do kernel
1043           QA it is safe to say n.
1044 
1045 config X86_THERMAL_VECTOR
1046         def_bool y
1047         depends on X86_MCE_INTEL
1048 
1049 config X86_LEGACY_VM86
1050         bool "Legacy VM86 support"
1051         default n
1052         depends on X86_32
1053         ---help---
1054           This option allows user programs to put the CPU into V8086
1055           mode, which is an 80286-era approximation of 16-bit real mode.
1056 
1057           Some very old versions of X and/or vbetool require this option
1058           for user mode setting.  Similarly, DOSEMU will use it if
1059           available to accelerate real mode DOS programs.  However, any
1060           recent version of DOSEMU, X, or vbetool should be fully
1061           functional even without kernel VM86 support, as they will all
1062           fall back to software emulation. Nevertheless, if you are using
1063           a 16-bit DOS program where 16-bit performance matters, vm86
1064           mode might be faster than emulation and you might want to
1065           enable this option.
1066 
1067           Note that any app that works on a 64-bit kernel is unlikely to
1068           need this option, as 64-bit kernels don't, and can't, support
1069           V8086 mode. This option is also unrelated to 16-bit protected
1070           mode and is not needed to run most 16-bit programs under Wine.
1071 
1072           Enabling this option increases the complexity of the kernel
1073           and slows down exception handling a tiny bit.
1074 
1075           If unsure, say N here.
1076 
1077 config VM86
1078        bool
1079        default X86_LEGACY_VM86
1080 
1081 config X86_16BIT
1082         bool "Enable support for 16-bit segments" if EXPERT
1083         default y
1084         depends on MODIFY_LDT_SYSCALL
1085         ---help---
1086           This option is required by programs like Wine to run 16-bit
1087           protected mode legacy code on x86 processors.  Disabling
1088           this option saves about 300 bytes on i386, or around 6K text
1089           plus 16K runtime memory on x86-64,
1090 
1091 config X86_ESPFIX32
1092         def_bool y
1093         depends on X86_16BIT && X86_32
1094 
1095 config X86_ESPFIX64
1096         def_bool y
1097         depends on X86_16BIT && X86_64
1098 
1099 config X86_VSYSCALL_EMULATION
1100        bool "Enable vsyscall emulation" if EXPERT
1101        default y
1102        depends on X86_64
1103        ---help---
1104          This enables emulation of the legacy vsyscall page.  Disabling
1105          it is roughly equivalent to booting with vsyscall=none, except
1106          that it will also disable the helpful warning if a program
1107          tries to use a vsyscall.  With this option set to N, offending
1108          programs will just segfault, citing addresses of the form
1109          0xffffffffff600?00.
1110 
1111          This option is required by many programs built before 2013, and
1112          care should be used even with newer programs if set to N.
1113 
1114          Disabling this option saves about 7K of kernel size and
1115          possibly 4K of additional runtime pagetable memory.
1116 
1117 config TOSHIBA
1118         tristate "Toshiba Laptop support"
1119         depends on X86_32
1120         ---help---
1121           This adds a driver to safely access the System Management Mode of
1122           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1123           not work on models with a Phoenix BIOS. The System Management Mode
1124           is used to set the BIOS and power saving options on Toshiba portables.
1125 
1126           For information on utilities to make use of this driver see the
1127           Toshiba Linux utilities web site at:
1128           <http://www.buzzard.org.uk/toshiba/>.
1129 
1130           Say Y if you intend to run this kernel on a Toshiba portable.
1131           Say N otherwise.
1132 
1133 config I8K
1134         tristate "Dell i8k legacy laptop support"
1135         select HWMON
1136         select SENSORS_DELL_SMM
1137         ---help---
1138           This option enables legacy /proc/i8k userspace interface in hwmon
1139           dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1140           temperature and allows controlling fan speeds of Dell laptops via
1141           System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1142           it reports also power and hotkey status. For fan speed control is
1143           needed userspace package i8kutils.
1144 
1145           Say Y if you intend to run this kernel on old Dell laptops or want to
1146           use userspace package i8kutils.
1147           Say N otherwise.
1148 
1149 config X86_REBOOTFIXUPS
1150         bool "Enable X86 board specific fixups for reboot"
1151         depends on X86_32
1152         ---help---
1153           This enables chipset and/or board specific fixups to be done
1154           in order to get reboot to work correctly. This is only needed on
1155           some combinations of hardware and BIOS. The symptom, for which
1156           this config is intended, is when reboot ends with a stalled/hung
1157           system.
1158 
1159           Currently, the only fixup is for the Geode machines using
1160           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1161 
1162           Say Y if you want to enable the fixup. Currently, it's safe to
1163           enable this option even if you don't need it.
1164           Say N otherwise.
1165 
1166 config MICROCODE
1167         bool "CPU microcode loading support"
1168         default y
1169         depends on CPU_SUP_AMD || CPU_SUP_INTEL
1170         select FW_LOADER
1171         ---help---
1172           If you say Y here, you will be able to update the microcode on
1173           Intel and AMD processors. The Intel support is for the IA32 family,
1174           e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1175           AMD support is for families 0x10 and later. You will obviously need
1176           the actual microcode binary data itself which is not shipped with
1177           the Linux kernel.
1178 
1179           The preferred method to load microcode from a detached initrd is described
1180           in Documentation/x86/early-microcode.txt. For that you need to enable
1181           CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1182           initrd for microcode blobs.
1183 
1184           In addition, you can build-in the microcode into the kernel. For that you
1185           need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1186           to the CONFIG_EXTRA_FIRMWARE config option.
1187 
1188 config MICROCODE_INTEL
1189         bool "Intel microcode loading support"
1190         depends on MICROCODE
1191         default MICROCODE
1192         select FW_LOADER
1193         ---help---
1194           This options enables microcode patch loading support for Intel
1195           processors.
1196 
1197           For the current Intel microcode data package go to
1198           <https://downloadcenter.intel.com> and search for
1199           'Linux Processor Microcode Data File'.
1200 
1201 config MICROCODE_AMD
1202         bool "AMD microcode loading support"
1203         depends on MICROCODE
1204         select FW_LOADER
1205         ---help---
1206           If you select this option, microcode patch loading support for AMD
1207           processors will be enabled.
1208 
1209 config MICROCODE_OLD_INTERFACE
1210         def_bool y
1211         depends on MICROCODE
1212 
1213 config PERF_EVENTS_AMD_POWER
1214         depends on PERF_EVENTS && CPU_SUP_AMD
1215         tristate "AMD Processor Power Reporting Mechanism"
1216         ---help---
1217           Provide power reporting mechanism support for AMD processors.
1218           Currently, it leverages X86_FEATURE_ACC_POWER
1219           (CPUID Fn8000_0007_EDX[12]) interface to calculate the
1220           average power consumption on Family 15h processors.
1221 
1222 config X86_MSR
1223         tristate "/dev/cpu/*/msr - Model-specific register support"
1224         ---help---
1225           This device gives privileged processes access to the x86
1226           Model-Specific Registers (MSRs).  It is a character device with
1227           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1228           MSR accesses are directed to a specific CPU on multi-processor
1229           systems.
1230 
1231 config X86_CPUID
1232         tristate "/dev/cpu/*/cpuid - CPU information support"
1233         ---help---
1234           This device gives processes access to the x86 CPUID instruction to
1235           be executed on a specific processor.  It is a character device
1236           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1237           /dev/cpu/31/cpuid.
1238 
1239 choice
1240         prompt "High Memory Support"
1241         default HIGHMEM4G
1242         depends on X86_32
1243 
1244 config NOHIGHMEM
1245         bool "off"
1246         ---help---
1247           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1248           However, the address space of 32-bit x86 processors is only 4
1249           Gigabytes large. That means that, if you have a large amount of
1250           physical memory, not all of it can be "permanently mapped" by the
1251           kernel. The physical memory that's not permanently mapped is called
1252           "high memory".
1253 
1254           If you are compiling a kernel which will never run on a machine with
1255           more than 1 Gigabyte total physical RAM, answer "off" here (default
1256           choice and suitable for most users). This will result in a "3GB/1GB"
1257           split: 3GB are mapped so that each process sees a 3GB virtual memory
1258           space and the remaining part of the 4GB virtual memory space is used
1259           by the kernel to permanently map as much physical memory as
1260           possible.
1261 
1262           If the machine has between 1 and 4 Gigabytes physical RAM, then
1263           answer "4GB" here.
1264 
1265           If more than 4 Gigabytes is used then answer "64GB" here. This
1266           selection turns Intel PAE (Physical Address Extension) mode on.
1267           PAE implements 3-level paging on IA32 processors. PAE is fully
1268           supported by Linux, PAE mode is implemented on all recent Intel
1269           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1270           then the kernel will not boot on CPUs that don't support PAE!
1271 
1272           The actual amount of total physical memory will either be
1273           auto detected or can be forced by using a kernel command line option
1274           such as "mem=256M". (Try "man bootparam" or see the documentation of
1275           your boot loader (lilo or loadlin) about how to pass options to the
1276           kernel at boot time.)
1277 
1278           If unsure, say "off".
1279 
1280 config HIGHMEM4G
1281         bool "4GB"
1282         ---help---
1283           Select this if you have a 32-bit processor and between 1 and 4
1284           gigabytes of physical RAM.
1285 
1286 config HIGHMEM64G
1287         bool "64GB"
1288         depends on !M486
1289         select X86_PAE
1290         ---help---
1291           Select this if you have a 32-bit processor and more than 4
1292           gigabytes of physical RAM.
1293 
1294 endchoice
1295 
1296 choice
1297         prompt "Memory split" if EXPERT
1298         default VMSPLIT_3G
1299         depends on X86_32
1300         ---help---
1301           Select the desired split between kernel and user memory.
1302 
1303           If the address range available to the kernel is less than the
1304           physical memory installed, the remaining memory will be available
1305           as "high memory". Accessing high memory is a little more costly
1306           than low memory, as it needs to be mapped into the kernel first.
1307           Note that increasing the kernel address space limits the range
1308           available to user programs, making the address space there
1309           tighter.  Selecting anything other than the default 3G/1G split
1310           will also likely make your kernel incompatible with binary-only
1311           kernel modules.
1312 
1313           If you are not absolutely sure what you are doing, leave this
1314           option alone!
1315 
1316         config VMSPLIT_3G
1317                 bool "3G/1G user/kernel split"
1318         config VMSPLIT_3G_OPT
1319                 depends on !X86_PAE
1320                 bool "3G/1G user/kernel split (for full 1G low memory)"
1321         config VMSPLIT_2G
1322                 bool "2G/2G user/kernel split"
1323         config VMSPLIT_2G_OPT
1324                 depends on !X86_PAE
1325                 bool "2G/2G user/kernel split (for full 2G low memory)"
1326         config VMSPLIT_1G
1327                 bool "1G/3G user/kernel split"
1328 endchoice
1329 
1330 config PAGE_OFFSET
1331         hex
1332         default 0xB0000000 if VMSPLIT_3G_OPT
1333         default 0x80000000 if VMSPLIT_2G
1334         default 0x78000000 if VMSPLIT_2G_OPT
1335         default 0x40000000 if VMSPLIT_1G
1336         default 0xC0000000
1337         depends on X86_32
1338 
1339 config HIGHMEM
1340         def_bool y
1341         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1342 
1343 config X86_PAE
1344         bool "PAE (Physical Address Extension) Support"
1345         depends on X86_32 && !HIGHMEM4G
1346         select SWIOTLB
1347         ---help---
1348           PAE is required for NX support, and furthermore enables
1349           larger swapspace support for non-overcommit purposes. It
1350           has the cost of more pagetable lookup overhead, and also
1351           consumes more pagetable space per process.
1352 
1353 config ARCH_PHYS_ADDR_T_64BIT
1354         def_bool y
1355         depends on X86_64 || X86_PAE
1356 
1357 config ARCH_DMA_ADDR_T_64BIT
1358         def_bool y
1359         depends on X86_64 || HIGHMEM64G
1360 
1361 config X86_DIRECT_GBPAGES
1362         def_bool y
1363         depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1364         ---help---
1365           Certain kernel features effectively disable kernel
1366           linear 1 GB mappings (even if the CPU otherwise
1367           supports them), so don't confuse the user by printing
1368           that we have them enabled.
1369 
1370 # Common NUMA Features
1371 config NUMA
1372         bool "Numa Memory Allocation and Scheduler Support"
1373         depends on SMP
1374         depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1375         default y if X86_BIGSMP
1376         ---help---
1377           Enable NUMA (Non Uniform Memory Access) support.
1378 
1379           The kernel will try to allocate memory used by a CPU on the
1380           local memory controller of the CPU and add some more
1381           NUMA awareness to the kernel.
1382 
1383           For 64-bit this is recommended if the system is Intel Core i7
1384           (or later), AMD Opteron, or EM64T NUMA.
1385 
1386           For 32-bit this is only needed if you boot a 32-bit
1387           kernel on a 64-bit NUMA platform.
1388 
1389           Otherwise, you should say N.
1390 
1391 config AMD_NUMA
1392         def_bool y
1393         prompt "Old style AMD Opteron NUMA detection"
1394         depends on X86_64 && NUMA && PCI
1395         ---help---
1396           Enable AMD NUMA node topology detection.  You should say Y here if
1397           you have a multi processor AMD system. This uses an old method to
1398           read the NUMA configuration directly from the builtin Northbridge
1399           of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1400           which also takes priority if both are compiled in.
1401 
1402 config X86_64_ACPI_NUMA
1403         def_bool y
1404         prompt "ACPI NUMA detection"
1405         depends on X86_64 && NUMA && ACPI && PCI
1406         select ACPI_NUMA
1407         ---help---
1408           Enable ACPI SRAT based node topology detection.
1409 
1410 # Some NUMA nodes have memory ranges that span
1411 # other nodes.  Even though a pfn is valid and
1412 # between a node's start and end pfns, it may not
1413 # reside on that node.  See memmap_init_zone()
1414 # for details.
1415 config NODES_SPAN_OTHER_NODES
1416         def_bool y
1417         depends on X86_64_ACPI_NUMA
1418 
1419 config NUMA_EMU
1420         bool "NUMA emulation"
1421         depends on NUMA
1422         ---help---
1423           Enable NUMA emulation. A flat machine will be split
1424           into virtual nodes when booted with "numa=fake=N", where N is the
1425           number of nodes. This is only useful for debugging.
1426 
1427 config NODES_SHIFT
1428         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1429         range 1 10
1430         default "10" if MAXSMP
1431         default "6" if X86_64
1432         default "3"
1433         depends on NEED_MULTIPLE_NODES
1434         ---help---
1435           Specify the maximum number of NUMA Nodes available on the target
1436           system.  Increases memory reserved to accommodate various tables.
1437 
1438 config ARCH_HAVE_MEMORY_PRESENT
1439         def_bool y
1440         depends on X86_32 && DISCONTIGMEM
1441 
1442 config NEED_NODE_MEMMAP_SIZE
1443         def_bool y
1444         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1445 
1446 config ARCH_FLATMEM_ENABLE
1447         def_bool y
1448         depends on X86_32 && !NUMA
1449 
1450 config ARCH_DISCONTIGMEM_ENABLE
1451         def_bool y
1452         depends on NUMA && X86_32
1453 
1454 config ARCH_DISCONTIGMEM_DEFAULT
1455         def_bool y
1456         depends on NUMA && X86_32
1457 
1458 config ARCH_SPARSEMEM_ENABLE
1459         def_bool y
1460         depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1461         select SPARSEMEM_STATIC if X86_32
1462         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1463 
1464 config ARCH_SPARSEMEM_DEFAULT
1465         def_bool y
1466         depends on X86_64
1467 
1468 config ARCH_SELECT_MEMORY_MODEL
1469         def_bool y
1470         depends on ARCH_SPARSEMEM_ENABLE
1471 
1472 config ARCH_MEMORY_PROBE
1473         bool "Enable sysfs memory/probe interface"
1474         depends on X86_64 && MEMORY_HOTPLUG
1475         help
1476           This option enables a sysfs memory/probe interface for testing.
1477           See Documentation/memory-hotplug.txt for more information.
1478           If you are unsure how to answer this question, answer N.
1479 
1480 config ARCH_PROC_KCORE_TEXT
1481         def_bool y
1482         depends on X86_64 && PROC_KCORE
1483 
1484 config ILLEGAL_POINTER_VALUE
1485        hex
1486        default 0 if X86_32
1487        default 0xdead000000000000 if X86_64
1488 
1489 source "mm/Kconfig"
1490 
1491 config X86_PMEM_LEGACY_DEVICE
1492         bool
1493 
1494 config X86_PMEM_LEGACY
1495         tristate "Support non-standard NVDIMMs and ADR protected memory"
1496         depends on PHYS_ADDR_T_64BIT
1497         depends on BLK_DEV
1498         select X86_PMEM_LEGACY_DEVICE
1499         select LIBNVDIMM
1500         help
1501           Treat memory marked using the non-standard e820 type of 12 as used
1502           by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1503           The kernel will offer these regions to the 'pmem' driver so
1504           they can be used for persistent storage.
1505 
1506           Say Y if unsure.
1507 
1508 config HIGHPTE
1509         bool "Allocate 3rd-level pagetables from highmem"
1510         depends on HIGHMEM
1511         ---help---
1512           The VM uses one page table entry for each page of physical memory.
1513           For systems with a lot of RAM, this can be wasteful of precious
1514           low memory.  Setting this option will put user-space page table
1515           entries in high memory.
1516 
1517 config X86_CHECK_BIOS_CORRUPTION
1518         bool "Check for low memory corruption"
1519         ---help---
1520           Periodically check for memory corruption in low memory, which
1521           is suspected to be caused by BIOS.  Even when enabled in the
1522           configuration, it is disabled at runtime.  Enable it by
1523           setting "memory_corruption_check=1" on the kernel command
1524           line.  By default it scans the low 64k of memory every 60
1525           seconds; see the memory_corruption_check_size and
1526           memory_corruption_check_period parameters in
1527           Documentation/kernel-parameters.txt to adjust this.
1528 
1529           When enabled with the default parameters, this option has
1530           almost no overhead, as it reserves a relatively small amount
1531           of memory and scans it infrequently.  It both detects corruption
1532           and prevents it from affecting the running system.
1533 
1534           It is, however, intended as a diagnostic tool; if repeatable
1535           BIOS-originated corruption always affects the same memory,
1536           you can use memmap= to prevent the kernel from using that
1537           memory.
1538 
1539 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1540         bool "Set the default setting of memory_corruption_check"
1541         depends on X86_CHECK_BIOS_CORRUPTION
1542         default y
1543         ---help---
1544           Set whether the default state of memory_corruption_check is
1545           on or off.
1546 
1547 config X86_RESERVE_LOW
1548         int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1549         default 64
1550         range 4 640
1551         ---help---
1552           Specify the amount of low memory to reserve for the BIOS.
1553 
1554           The first page contains BIOS data structures that the kernel
1555           must not use, so that page must always be reserved.
1556 
1557           By default we reserve the first 64K of physical RAM, as a
1558           number of BIOSes are known to corrupt that memory range
1559           during events such as suspend/resume or monitor cable
1560           insertion, so it must not be used by the kernel.
1561 
1562           You can set this to 4 if you are absolutely sure that you
1563           trust the BIOS to get all its memory reservations and usages
1564           right.  If you know your BIOS have problems beyond the
1565           default 64K area, you can set this to 640 to avoid using the
1566           entire low memory range.
1567 
1568           If you have doubts about the BIOS (e.g. suspend/resume does
1569           not work or there's kernel crashes after certain hardware
1570           hotplug events) then you might want to enable
1571           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1572           typical corruption patterns.
1573 
1574           Leave this to the default value of 64 if you are unsure.
1575 
1576 config MATH_EMULATION
1577         bool
1578         depends on MODIFY_LDT_SYSCALL
1579         prompt "Math emulation" if X86_32
1580         ---help---
1581           Linux can emulate a math coprocessor (used for floating point
1582           operations) if you don't have one. 486DX and Pentium processors have
1583           a math coprocessor built in, 486SX and 386 do not, unless you added
1584           a 487DX or 387, respectively. (The messages during boot time can
1585           give you some hints here ["man dmesg"].) Everyone needs either a
1586           coprocessor or this emulation.
1587 
1588           If you don't have a math coprocessor, you need to say Y here; if you
1589           say Y here even though you have a coprocessor, the coprocessor will
1590           be used nevertheless. (This behavior can be changed with the kernel
1591           command line option "no387", which comes handy if your coprocessor
1592           is broken. Try "man bootparam" or see the documentation of your boot
1593           loader (lilo or loadlin) about how to pass options to the kernel at
1594           boot time.) This means that it is a good idea to say Y here if you
1595           intend to use this kernel on different machines.
1596 
1597           More information about the internals of the Linux math coprocessor
1598           emulation can be found in <file:arch/x86/math-emu/README>.
1599 
1600           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1601           kernel, it won't hurt.
1602 
1603 config MTRR
1604         def_bool y
1605         prompt "MTRR (Memory Type Range Register) support" if EXPERT
1606         ---help---
1607           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1608           the Memory Type Range Registers (MTRRs) may be used to control
1609           processor access to memory ranges. This is most useful if you have
1610           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1611           allows bus write transfers to be combined into a larger transfer
1612           before bursting over the PCI/AGP bus. This can increase performance
1613           of image write operations 2.5 times or more. Saying Y here creates a
1614           /proc/mtrr file which may be used to manipulate your processor's
1615           MTRRs. Typically the X server should use this.
1616 
1617           This code has a reasonably generic interface so that similar
1618           control registers on other processors can be easily supported
1619           as well:
1620 
1621           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1622           Registers (ARRs) which provide a similar functionality to MTRRs. For
1623           these, the ARRs are used to emulate the MTRRs.
1624           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1625           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1626           write-combining. All of these processors are supported by this code
1627           and it makes sense to say Y here if you have one of them.
1628 
1629           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1630           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1631           can lead to all sorts of problems, so it's good to say Y here.
1632 
1633           You can safely say Y even if your machine doesn't have MTRRs, you'll
1634           just add about 9 KB to your kernel.
1635 
1636           See <file:Documentation/x86/mtrr.txt> for more information.
1637 
1638 config MTRR_SANITIZER
1639         def_bool y
1640         prompt "MTRR cleanup support"
1641         depends on MTRR
1642         ---help---
1643           Convert MTRR layout from continuous to discrete, so X drivers can
1644           add writeback entries.
1645 
1646           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1647           The largest mtrr entry size for a continuous block can be set with
1648           mtrr_chunk_size.
1649 
1650           If unsure, say Y.
1651 
1652 config MTRR_SANITIZER_ENABLE_DEFAULT
1653         int "MTRR cleanup enable value (0-1)"
1654         range 0 1
1655         default "0"
1656         depends on MTRR_SANITIZER
1657         ---help---
1658           Enable mtrr cleanup default value
1659 
1660 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1661         int "MTRR cleanup spare reg num (0-7)"
1662         range 0 7
1663         default "1"
1664         depends on MTRR_SANITIZER
1665         ---help---
1666           mtrr cleanup spare entries default, it can be changed via
1667           mtrr_spare_reg_nr=N on the kernel command line.
1668 
1669 config X86_PAT
1670         def_bool y
1671         prompt "x86 PAT support" if EXPERT
1672         depends on MTRR
1673         ---help---
1674           Use PAT attributes to setup page level cache control.
1675 
1676           PATs are the modern equivalents of MTRRs and are much more
1677           flexible than MTRRs.
1678 
1679           Say N here if you see bootup problems (boot crash, boot hang,
1680           spontaneous reboots) or a non-working video driver.
1681 
1682           If unsure, say Y.
1683 
1684 config ARCH_USES_PG_UNCACHED
1685         def_bool y
1686         depends on X86_PAT
1687 
1688 config ARCH_RANDOM
1689         def_bool y
1690         prompt "x86 architectural random number generator" if EXPERT
1691         ---help---
1692           Enable the x86 architectural RDRAND instruction
1693           (Intel Bull Mountain technology) to generate random numbers.
1694           If supported, this is a high bandwidth, cryptographically
1695           secure hardware random number generator.
1696 
1697 config X86_SMAP
1698         def_bool y
1699         prompt "Supervisor Mode Access Prevention" if EXPERT
1700         ---help---
1701           Supervisor Mode Access Prevention (SMAP) is a security
1702           feature in newer Intel processors.  There is a small
1703           performance cost if this enabled and turned on; there is
1704           also a small increase in the kernel size if this is enabled.
1705 
1706           If unsure, say Y.
1707 
1708 config X86_INTEL_MPX
1709         prompt "Intel MPX (Memory Protection Extensions)"
1710         def_bool n
1711         depends on CPU_SUP_INTEL
1712         ---help---
1713           MPX provides hardware features that can be used in
1714           conjunction with compiler-instrumented code to check
1715           memory references.  It is designed to detect buffer
1716           overflow or underflow bugs.
1717 
1718           This option enables running applications which are
1719           instrumented or otherwise use MPX.  It does not use MPX
1720           itself inside the kernel or to protect the kernel
1721           against bad memory references.
1722 
1723           Enabling this option will make the kernel larger:
1724           ~8k of kernel text and 36 bytes of data on a 64-bit
1725           defconfig.  It adds a long to the 'mm_struct' which
1726           will increase the kernel memory overhead of each
1727           process and adds some branches to paths used during
1728           exec() and munmap().
1729 
1730           For details, see Documentation/x86/intel_mpx.txt
1731 
1732           If unsure, say N.
1733 
1734 config X86_INTEL_MEMORY_PROTECTION_KEYS
1735         prompt "Intel Memory Protection Keys"
1736         def_bool y
1737         # Note: only available in 64-bit mode
1738         depends on CPU_SUP_INTEL && X86_64
1739         ---help---
1740           Memory Protection Keys provides a mechanism for enforcing
1741           page-based protections, but without requiring modification of the
1742           page tables when an application changes protection domains.
1743 
1744           For details, see Documentation/x86/protection-keys.txt
1745 
1746           If unsure, say y.
1747 
1748 config EFI
1749         bool "EFI runtime service support"
1750         depends on ACPI
1751         select UCS2_STRING
1752         select EFI_RUNTIME_WRAPPERS
1753         ---help---
1754           This enables the kernel to use EFI runtime services that are
1755           available (such as the EFI variable services).
1756 
1757           This option is only useful on systems that have EFI firmware.
1758           In addition, you should use the latest ELILO loader available
1759           at <http://elilo.sourceforge.net> in order to take advantage
1760           of EFI runtime services. However, even with this option, the
1761           resultant kernel should continue to boot on existing non-EFI
1762           platforms.
1763 
1764 config EFI_STUB
1765        bool "EFI stub support"
1766        depends on EFI && !X86_USE_3DNOW
1767        select RELOCATABLE
1768        ---help---
1769           This kernel feature allows a bzImage to be loaded directly
1770           by EFI firmware without the use of a bootloader.
1771 
1772           See Documentation/efi-stub.txt for more information.
1773 
1774 config EFI_MIXED
1775         bool "EFI mixed-mode support"
1776         depends on EFI_STUB && X86_64
1777         ---help---
1778            Enabling this feature allows a 64-bit kernel to be booted
1779            on a 32-bit firmware, provided that your CPU supports 64-bit
1780            mode.
1781 
1782            Note that it is not possible to boot a mixed-mode enabled
1783            kernel via the EFI boot stub - a bootloader that supports
1784            the EFI handover protocol must be used.
1785 
1786            If unsure, say N.
1787 
1788 config SECCOMP
1789         def_bool y
1790         prompt "Enable seccomp to safely compute untrusted bytecode"
1791         ---help---
1792           This kernel feature is useful for number crunching applications
1793           that may need to compute untrusted bytecode during their
1794           execution. By using pipes or other transports made available to
1795           the process as file descriptors supporting the read/write
1796           syscalls, it's possible to isolate those applications in
1797           their own address space using seccomp. Once seccomp is
1798           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1799           and the task is only allowed to execute a few safe syscalls
1800           defined by each seccomp mode.
1801 
1802           If unsure, say Y. Only embedded should say N here.
1803 
1804 source kernel/Kconfig.hz
1805 
1806 config KEXEC
1807         bool "kexec system call"
1808         select KEXEC_CORE
1809         ---help---
1810           kexec is a system call that implements the ability to shutdown your
1811           current kernel, and to start another kernel.  It is like a reboot
1812           but it is independent of the system firmware.   And like a reboot
1813           you can start any kernel with it, not just Linux.
1814 
1815           The name comes from the similarity to the exec system call.
1816 
1817           It is an ongoing process to be certain the hardware in a machine
1818           is properly shutdown, so do not be surprised if this code does not
1819           initially work for you.  As of this writing the exact hardware
1820           interface is strongly in flux, so no good recommendation can be
1821           made.
1822 
1823 config KEXEC_FILE
1824         bool "kexec file based system call"
1825         select KEXEC_CORE
1826         select BUILD_BIN2C
1827         depends on X86_64
1828         depends on CRYPTO=y
1829         depends on CRYPTO_SHA256=y
1830         ---help---
1831           This is new version of kexec system call. This system call is
1832           file based and takes file descriptors as system call argument
1833           for kernel and initramfs as opposed to list of segments as
1834           accepted by previous system call.
1835 
1836 config KEXEC_VERIFY_SIG
1837         bool "Verify kernel signature during kexec_file_load() syscall"
1838         depends on KEXEC_FILE
1839         ---help---
1840           This option makes kernel signature verification mandatory for
1841           the kexec_file_load() syscall.
1842 
1843           In addition to that option, you need to enable signature
1844           verification for the corresponding kernel image type being
1845           loaded in order for this to work.
1846 
1847 config KEXEC_BZIMAGE_VERIFY_SIG
1848         bool "Enable bzImage signature verification support"
1849         depends on KEXEC_VERIFY_SIG
1850         depends on SIGNED_PE_FILE_VERIFICATION
1851         select SYSTEM_TRUSTED_KEYRING
1852         ---help---
1853           Enable bzImage signature verification support.
1854 
1855 config CRASH_DUMP
1856         bool "kernel crash dumps"
1857         depends on X86_64 || (X86_32 && HIGHMEM)
1858         ---help---
1859           Generate crash dump after being started by kexec.
1860           This should be normally only set in special crash dump kernels
1861           which are loaded in the main kernel with kexec-tools into
1862           a specially reserved region and then later executed after
1863           a crash by kdump/kexec. The crash dump kernel must be compiled
1864           to a memory address not used by the main kernel or BIOS using
1865           PHYSICAL_START, or it must be built as a relocatable image
1866           (CONFIG_RELOCATABLE=y).
1867           For more details see Documentation/kdump/kdump.txt
1868 
1869 config KEXEC_JUMP
1870         bool "kexec jump"
1871         depends on KEXEC && HIBERNATION
1872         ---help---
1873           Jump between original kernel and kexeced kernel and invoke
1874           code in physical address mode via KEXEC
1875 
1876 config PHYSICAL_START
1877         hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1878         default "0x1000000"
1879         ---help---
1880           This gives the physical address where the kernel is loaded.
1881 
1882           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1883           bzImage will decompress itself to above physical address and
1884           run from there. Otherwise, bzImage will run from the address where
1885           it has been loaded by the boot loader and will ignore above physical
1886           address.
1887 
1888           In normal kdump cases one does not have to set/change this option
1889           as now bzImage can be compiled as a completely relocatable image
1890           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1891           address. This option is mainly useful for the folks who don't want
1892           to use a bzImage for capturing the crash dump and want to use a
1893           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1894           to be specifically compiled to run from a specific memory area
1895           (normally a reserved region) and this option comes handy.
1896 
1897           So if you are using bzImage for capturing the crash dump,
1898           leave the value here unchanged to 0x1000000 and set
1899           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1900           for capturing the crash dump change this value to start of
1901           the reserved region.  In other words, it can be set based on
1902           the "X" value as specified in the "crashkernel=YM@XM"
1903           command line boot parameter passed to the panic-ed
1904           kernel. Please take a look at Documentation/kdump/kdump.txt
1905           for more details about crash dumps.
1906 
1907           Usage of bzImage for capturing the crash dump is recommended as
1908           one does not have to build two kernels. Same kernel can be used
1909           as production kernel and capture kernel. Above option should have
1910           gone away after relocatable bzImage support is introduced. But it
1911           is present because there are users out there who continue to use
1912           vmlinux for dump capture. This option should go away down the
1913           line.
1914 
1915           Don't change this unless you know what you are doing.
1916 
1917 config RELOCATABLE
1918         bool "Build a relocatable kernel"
1919         default y
1920         ---help---
1921           This builds a kernel image that retains relocation information
1922           so it can be loaded someplace besides the default 1MB.
1923           The relocations tend to make the kernel binary about 10% larger,
1924           but are discarded at runtime.
1925 
1926           One use is for the kexec on panic case where the recovery kernel
1927           must live at a different physical address than the primary
1928           kernel.
1929 
1930           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1931           it has been loaded at and the compile time physical address
1932           (CONFIG_PHYSICAL_START) is used as the minimum location.
1933 
1934 config RANDOMIZE_BASE
1935         bool "Randomize the address of the kernel image"
1936         depends on RELOCATABLE
1937         default n
1938         ---help---
1939            Randomizes the physical and virtual address at which the
1940            kernel image is decompressed, as a security feature that
1941            deters exploit attempts relying on knowledge of the location
1942            of kernel internals.
1943 
1944            Entropy is generated using the RDRAND instruction if it is
1945            supported. If RDTSC is supported, it is used as well. If
1946            neither RDRAND nor RDTSC are supported, then randomness is
1947            read from the i8254 timer.
1948 
1949            The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1950            and aligned according to PHYSICAL_ALIGN. Since the kernel is
1951            built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1952            minimum of 2MiB, only 10 bits of entropy is theoretically
1953            possible. At best, due to page table layouts, 64-bit can use
1954            9 bits of entropy and 32-bit uses 8 bits.
1955 
1956            If unsure, say N.
1957 
1958 config RANDOMIZE_BASE_MAX_OFFSET
1959         hex "Maximum kASLR offset allowed" if EXPERT
1960         depends on RANDOMIZE_BASE
1961         range 0x0 0x20000000 if X86_32
1962         default "0x20000000" if X86_32
1963         range 0x0 0x40000000 if X86_64
1964         default "0x40000000" if X86_64
1965         ---help---
1966           The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1967           memory is used to determine the maximal offset in bytes that will
1968           be applied to the kernel when kernel Address Space Layout
1969           Randomization (kASLR) is active. This must be a multiple of
1970           PHYSICAL_ALIGN.
1971 
1972           On 32-bit this is limited to 512MiB by page table layouts. The
1973           default is 512MiB.
1974 
1975           On 64-bit this is limited by how the kernel fixmap page table is
1976           positioned, so this cannot be larger than 1GiB currently. Without
1977           RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1978           and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1979           modules area will shrink to compensate, up to the current maximum
1980           1GiB to 1GiB split. The default is 1GiB.
1981 
1982           If unsure, leave at the default value.
1983 
1984 # Relocation on x86 needs some additional build support
1985 config X86_NEED_RELOCS
1986         def_bool y
1987         depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1988 
1989 config PHYSICAL_ALIGN
1990         hex "Alignment value to which kernel should be aligned"
1991         default "0x200000"
1992         range 0x2000 0x1000000 if X86_32
1993         range 0x200000 0x1000000 if X86_64
1994         ---help---
1995           This value puts the alignment restrictions on physical address
1996           where kernel is loaded and run from. Kernel is compiled for an
1997           address which meets above alignment restriction.
1998 
1999           If bootloader loads the kernel at a non-aligned address and
2000           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2001           address aligned to above value and run from there.
2002 
2003           If bootloader loads the kernel at a non-aligned address and
2004           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2005           load address and decompress itself to the address it has been
2006           compiled for and run from there. The address for which kernel is
2007           compiled already meets above alignment restrictions. Hence the
2008           end result is that kernel runs from a physical address meeting
2009           above alignment restrictions.
2010 
2011           On 32-bit this value must be a multiple of 0x2000. On 64-bit
2012           this value must be a multiple of 0x200000.
2013 
2014           Don't change this unless you know what you are doing.
2015 
2016 config HOTPLUG_CPU
2017         bool "Support for hot-pluggable CPUs"
2018         depends on SMP
2019         ---help---
2020           Say Y here to allow turning CPUs off and on. CPUs can be
2021           controlled through /sys/devices/system/cpu.
2022           ( Note: power management support will enable this option
2023             automatically on SMP systems. )
2024           Say N if you want to disable CPU hotplug.
2025 
2026 config BOOTPARAM_HOTPLUG_CPU0
2027         bool "Set default setting of cpu0_hotpluggable"
2028         default n
2029         depends on HOTPLUG_CPU
2030         ---help---
2031           Set whether default state of cpu0_hotpluggable is on or off.
2032 
2033           Say Y here to enable CPU0 hotplug by default. If this switch
2034           is turned on, there is no need to give cpu0_hotplug kernel
2035           parameter and the CPU0 hotplug feature is enabled by default.
2036 
2037           Please note: there are two known CPU0 dependencies if you want
2038           to enable the CPU0 hotplug feature either by this switch or by
2039           cpu0_hotplug kernel parameter.
2040 
2041           First, resume from hibernate or suspend always starts from CPU0.
2042           So hibernate and suspend are prevented if CPU0 is offline.
2043 
2044           Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2045           offline if any interrupt can not migrate out of CPU0. There may
2046           be other CPU0 dependencies.
2047 
2048           Please make sure the dependencies are under your control before
2049           you enable this feature.
2050 
2051           Say N if you don't want to enable CPU0 hotplug feature by default.
2052           You still can enable the CPU0 hotplug feature at boot by kernel
2053           parameter cpu0_hotplug.
2054 
2055 config DEBUG_HOTPLUG_CPU0
2056         def_bool n
2057         prompt "Debug CPU0 hotplug"
2058         depends on HOTPLUG_CPU
2059         ---help---
2060           Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2061           soon as possible and boots up userspace with CPU0 offlined. User
2062           can online CPU0 back after boot time.
2063 
2064           To debug CPU0 hotplug, you need to enable CPU0 offline/online
2065           feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2066           compilation or giving cpu0_hotplug kernel parameter at boot.
2067 
2068           If unsure, say N.
2069 
2070 config COMPAT_VDSO
2071         def_bool n
2072         prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2073         depends on X86_32 || IA32_EMULATION
2074         ---help---
2075           Certain buggy versions of glibc will crash if they are
2076           presented with a 32-bit vDSO that is not mapped at the address
2077           indicated in its segment table.
2078 
2079           The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2080           and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2081           49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2082           the only released version with the bug, but OpenSUSE 9
2083           contains a buggy "glibc 2.3.2".
2084 
2085           The symptom of the bug is that everything crashes on startup, saying:
2086           dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2087 
2088           Saying Y here changes the default value of the vdso32 boot
2089           option from 1 to 0, which turns off the 32-bit vDSO entirely.
2090           This works around the glibc bug but hurts performance.
2091 
2092           If unsure, say N: if you are compiling your own kernel, you
2093           are unlikely to be using a buggy version of glibc.
2094 
2095 choice
2096         prompt "vsyscall table for legacy applications"
2097         depends on X86_64
2098         default LEGACY_VSYSCALL_EMULATE
2099         help
2100           Legacy user code that does not know how to find the vDSO expects
2101           to be able to issue three syscalls by calling fixed addresses in
2102           kernel space. Since this location is not randomized with ASLR,
2103           it can be used to assist security vulnerability exploitation.
2104 
2105           This setting can be changed at boot time via the kernel command
2106           line parameter vsyscall=[native|emulate|none].
2107 
2108           On a system with recent enough glibc (2.14 or newer) and no
2109           static binaries, you can say None without a performance penalty
2110           to improve security.
2111 
2112           If unsure, select "Emulate".
2113 
2114         config LEGACY_VSYSCALL_NATIVE
2115                 bool "Native"
2116                 help
2117                   Actual executable code is located in the fixed vsyscall
2118                   address mapping, implementing time() efficiently. Since
2119                   this makes the mapping executable, it can be used during
2120                   security vulnerability exploitation (traditionally as
2121                   ROP gadgets). This configuration is not recommended.
2122 
2123         config LEGACY_VSYSCALL_EMULATE
2124                 bool "Emulate"
2125                 help
2126                   The kernel traps and emulates calls into the fixed
2127                   vsyscall address mapping. This makes the mapping
2128                   non-executable, but it still contains known contents,
2129                   which could be used in certain rare security vulnerability
2130                   exploits. This configuration is recommended when userspace
2131                   still uses the vsyscall area.
2132 
2133         config LEGACY_VSYSCALL_NONE
2134                 bool "None"
2135                 help
2136                   There will be no vsyscall mapping at all. This will
2137                   eliminate any risk of ASLR bypass due to the vsyscall
2138                   fixed address mapping. Attempts to use the vsyscalls
2139                   will be reported to dmesg, so that either old or
2140                   malicious userspace programs can be identified.
2141 
2142 endchoice
2143 
2144 config CMDLINE_BOOL
2145         bool "Built-in kernel command line"
2146         ---help---
2147           Allow for specifying boot arguments to the kernel at
2148           build time.  On some systems (e.g. embedded ones), it is
2149           necessary or convenient to provide some or all of the
2150           kernel boot arguments with the kernel itself (that is,
2151           to not rely on the boot loader to provide them.)
2152 
2153           To compile command line arguments into the kernel,
2154           set this option to 'Y', then fill in the
2155           boot arguments in CONFIG_CMDLINE.
2156 
2157           Systems with fully functional boot loaders (i.e. non-embedded)
2158           should leave this option set to 'N'.
2159 
2160 config CMDLINE
2161         string "Built-in kernel command string"
2162         depends on CMDLINE_BOOL
2163         default ""
2164         ---help---
2165           Enter arguments here that should be compiled into the kernel
2166           image and used at boot time.  If the boot loader provides a
2167           command line at boot time, it is appended to this string to
2168           form the full kernel command line, when the system boots.
2169 
2170           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2171           change this behavior.
2172 
2173           In most cases, the command line (whether built-in or provided
2174           by the boot loader) should specify the device for the root
2175           file system.
2176 
2177 config CMDLINE_OVERRIDE
2178         bool "Built-in command line overrides boot loader arguments"
2179         depends on CMDLINE_BOOL
2180         ---help---
2181           Set this option to 'Y' to have the kernel ignore the boot loader
2182           command line, and use ONLY the built-in command line.
2183 
2184           This is used to work around broken boot loaders.  This should
2185           be set to 'N' under normal conditions.
2186 
2187 config MODIFY_LDT_SYSCALL
2188         bool "Enable the LDT (local descriptor table)" if EXPERT
2189         default y
2190         ---help---
2191           Linux can allow user programs to install a per-process x86
2192           Local Descriptor Table (LDT) using the modify_ldt(2) system
2193           call.  This is required to run 16-bit or segmented code such as
2194           DOSEMU or some Wine programs.  It is also used by some very old
2195           threading libraries.
2196 
2197           Enabling this feature adds a small amount of overhead to
2198           context switches and increases the low-level kernel attack
2199           surface.  Disabling it removes the modify_ldt(2) system call.
2200 
2201           Saying 'N' here may make sense for embedded or server kernels.
2202 
2203 source "kernel/livepatch/Kconfig"
2204 
2205 endmenu
2206 
2207 config ARCH_ENABLE_MEMORY_HOTPLUG
2208         def_bool y
2209         depends on X86_64 || (X86_32 && HIGHMEM)
2210 
2211 config ARCH_ENABLE_MEMORY_HOTREMOVE
2212         def_bool y
2213         depends on MEMORY_HOTPLUG
2214 
2215 config USE_PERCPU_NUMA_NODE_ID
2216         def_bool y
2217         depends on NUMA
2218 
2219 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2220         def_bool y
2221         depends on X86_64 || X86_PAE
2222 
2223 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2224         def_bool y
2225         depends on X86_64 && HUGETLB_PAGE && MIGRATION
2226 
2227 menu "Power management and ACPI options"
2228 
2229 config ARCH_HIBERNATION_HEADER
2230         def_bool y
2231         depends on X86_64 && HIBERNATION
2232 
2233 source "kernel/power/Kconfig"
2234 
2235 source "drivers/acpi/Kconfig"
2236 
2237 source "drivers/sfi/Kconfig"
2238 
2239 config X86_APM_BOOT
2240         def_bool y
2241         depends on APM
2242 
2243 menuconfig APM
2244         tristate "APM (Advanced Power Management) BIOS support"
2245         depends on X86_32 && PM_SLEEP
2246         ---help---
2247           APM is a BIOS specification for saving power using several different
2248           techniques. This is mostly useful for battery powered laptops with
2249           APM compliant BIOSes. If you say Y here, the system time will be
2250           reset after a RESUME operation, the /proc/apm device will provide
2251           battery status information, and user-space programs will receive
2252           notification of APM "events" (e.g. battery status change).
2253 
2254           If you select "Y" here, you can disable actual use of the APM
2255           BIOS by passing the "apm=off" option to the kernel at boot time.
2256 
2257           Note that the APM support is almost completely disabled for
2258           machines with more than one CPU.
2259 
2260           In order to use APM, you will need supporting software. For location
2261           and more information, read <file:Documentation/power/apm-acpi.txt>
2262           and the Battery Powered Linux mini-HOWTO, available from
2263           <http://www.tldp.org/docs.html#howto>.
2264 
2265           This driver does not spin down disk drives (see the hdparm(8)
2266           manpage ("man 8 hdparm") for that), and it doesn't turn off
2267           VESA-compliant "green" monitors.
2268 
2269           This driver does not support the TI 4000M TravelMate and the ACER
2270           486/DX4/75 because they don't have compliant BIOSes. Many "green"
2271           desktop machines also don't have compliant BIOSes, and this driver
2272           may cause those machines to panic during the boot phase.
2273 
2274           Generally, if you don't have a battery in your machine, there isn't
2275           much point in using this driver and you should say N. If you get
2276           random kernel OOPSes or reboots that don't seem to be related to
2277           anything, try disabling/enabling this option (or disabling/enabling
2278           APM in your BIOS).
2279 
2280           Some other things you should try when experiencing seemingly random,
2281           "weird" problems:
2282 
2283           1) make sure that you have enough swap space and that it is
2284           enabled.
2285           2) pass the "no-hlt" option to the kernel
2286           3) switch on floating point emulation in the kernel and pass
2287           the "no387" option to the kernel
2288           4) pass the "floppy=nodma" option to the kernel
2289           5) pass the "mem=4M" option to the kernel (thereby disabling
2290           all but the first 4 MB of RAM)
2291           6) make sure that the CPU is not over clocked.
2292           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2293           8) disable the cache from your BIOS settings
2294           9) install a fan for the video card or exchange video RAM
2295           10) install a better fan for the CPU
2296           11) exchange RAM chips
2297           12) exchange the motherboard.
2298 
2299           To compile this driver as a module, choose M here: the
2300           module will be called apm.
2301 
2302 if APM
2303 
2304 config APM_IGNORE_USER_SUSPEND
2305         bool "Ignore USER SUSPEND"
2306         ---help---
2307           This option will ignore USER SUSPEND requests. On machines with a
2308           compliant APM BIOS, you want to say N. However, on the NEC Versa M
2309           series notebooks, it is necessary to say Y because of a BIOS bug.
2310 
2311 config APM_DO_ENABLE
2312         bool "Enable PM at boot time"
2313         ---help---
2314           Enable APM features at boot time. From page 36 of the APM BIOS
2315           specification: "When disabled, the APM BIOS does not automatically
2316           power manage devices, enter the Standby State, enter the Suspend
2317           State, or take power saving steps in response to CPU Idle calls."
2318           This driver will make CPU Idle calls when Linux is idle (unless this
2319           feature is turned off -- see "Do CPU IDLE calls", below). This
2320           should always save battery power, but more complicated APM features
2321           will be dependent on your BIOS implementation. You may need to turn
2322           this option off if your computer hangs at boot time when using APM
2323           support, or if it beeps continuously instead of suspending. Turn
2324           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2325           T400CDT. This is off by default since most machines do fine without
2326           this feature.
2327 
2328 config APM_CPU_IDLE
2329         depends on CPU_IDLE
2330         bool "Make CPU Idle calls when idle"
2331         ---help---
2332           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2333           On some machines, this can activate improved power savings, such as
2334           a slowed CPU clock rate, when the machine is idle. These idle calls
2335           are made after the idle loop has run for some length of time (e.g.,
2336           333 mS). On some machines, this will cause a hang at boot time or
2337           whenever the CPU becomes idle. (On machines with more than one CPU,
2338           this option does nothing.)
2339 
2340 config APM_DISPLAY_BLANK
2341         bool "Enable console blanking using APM"
2342         ---help---
2343           Enable console blanking using the APM. Some laptops can use this to
2344           turn off the LCD backlight when the screen blanker of the Linux
2345           virtual console blanks the screen. Note that this is only used by
2346           the virtual console screen blanker, and won't turn off the backlight
2347           when using the X Window system. This also doesn't have anything to
2348           do with your VESA-compliant power-saving monitor. Further, this
2349           option doesn't work for all laptops -- it might not turn off your
2350           backlight at all, or it might print a lot of errors to the console,
2351           especially if you are using gpm.
2352 
2353 config APM_ALLOW_INTS
2354         bool "Allow interrupts during APM BIOS calls"
2355         ---help---
2356           Normally we disable external interrupts while we are making calls to
2357           the APM BIOS as a measure to lessen the effects of a badly behaving
2358           BIOS implementation.  The BIOS should reenable interrupts if it
2359           needs to.  Unfortunately, some BIOSes do not -- especially those in
2360           many of the newer IBM Thinkpads.  If you experience hangs when you
2361           suspend, try setting this to Y.  Otherwise, say N.
2362 
2363 endif # APM
2364 
2365 source "drivers/cpufreq/Kconfig"
2366 
2367 source "drivers/cpuidle/Kconfig"
2368 
2369 source "drivers/idle/Kconfig"
2370 
2371 endmenu
2372 
2373 
2374 menu "Bus options (PCI etc.)"
2375 
2376 config PCI
2377         bool "PCI support"
2378         default y
2379         ---help---
2380           Find out whether you have a PCI motherboard. PCI is the name of a
2381           bus system, i.e. the way the CPU talks to the other stuff inside
2382           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2383           VESA. If you have PCI, say Y, otherwise N.
2384 
2385 choice
2386         prompt "PCI access mode"
2387         depends on X86_32 && PCI
2388         default PCI_GOANY
2389         ---help---
2390           On PCI systems, the BIOS can be used to detect the PCI devices and
2391           determine their configuration. However, some old PCI motherboards
2392           have BIOS bugs and may crash if this is done. Also, some embedded
2393           PCI-based systems don't have any BIOS at all. Linux can also try to
2394           detect the PCI hardware directly without using the BIOS.
2395 
2396           With this option, you can specify how Linux should detect the
2397           PCI devices. If you choose "BIOS", the BIOS will be used,
2398           if you choose "Direct", the BIOS won't be used, and if you
2399           choose "MMConfig", then PCI Express MMCONFIG will be used.
2400           If you choose "Any", the kernel will try MMCONFIG, then the
2401           direct access method and falls back to the BIOS if that doesn't
2402           work. If unsure, go with the default, which is "Any".
2403 
2404 config PCI_GOBIOS
2405         bool "BIOS"
2406 
2407 config PCI_GOMMCONFIG
2408         bool "MMConfig"
2409 
2410 config PCI_GODIRECT
2411         bool "Direct"
2412 
2413 config PCI_GOOLPC
2414         bool "OLPC XO-1"
2415         depends on OLPC
2416 
2417 config PCI_GOANY
2418         bool "Any"
2419 
2420 endchoice
2421 
2422 config PCI_BIOS
2423         def_bool y
2424         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2425 
2426 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2427 config PCI_DIRECT
2428         def_bool y
2429         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2430 
2431 config PCI_MMCONFIG
2432         def_bool y
2433         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2434 
2435 config PCI_OLPC
2436         def_bool y
2437         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2438 
2439 config PCI_XEN
2440         def_bool y
2441         depends on PCI && XEN
2442         select SWIOTLB_XEN
2443 
2444 config PCI_DOMAINS
2445         def_bool y
2446         depends on PCI
2447 
2448 config PCI_MMCONFIG
2449         bool "Support mmconfig PCI config space access"
2450         depends on X86_64 && PCI && ACPI
2451 
2452 config PCI_CNB20LE_QUIRK
2453         bool "Read CNB20LE Host Bridge Windows" if EXPERT
2454         depends on PCI
2455         help
2456           Read the PCI windows out of the CNB20LE host bridge. This allows
2457           PCI hotplug to work on systems with the CNB20LE chipset which do
2458           not have ACPI.
2459 
2460           There's no public spec for this chipset, and this functionality
2461           is known to be incomplete.
2462 
2463           You should say N unless you know you need this.
2464 
2465 source "drivers/pci/Kconfig"
2466 
2467 # x86_64 have no ISA slots, but can have ISA-style DMA.
2468 config ISA_DMA_API
2469         bool "ISA-style DMA support" if (X86_64 && EXPERT)
2470         default y
2471         help
2472           Enables ISA-style DMA support for devices requiring such controllers.
2473           If unsure, say Y.
2474 
2475 if X86_32
2476 
2477 config ISA
2478         bool "ISA support"
2479         ---help---
2480           Find out whether you have ISA slots on your motherboard.  ISA is the
2481           name of a bus system, i.e. the way the CPU talks to the other stuff
2482           inside your box.  Other bus systems are PCI, EISA, MicroChannel
2483           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2484           newer boards don't support it.  If you have ISA, say Y, otherwise N.
2485 
2486 config EISA
2487         bool "EISA support"
2488         depends on ISA
2489         ---help---
2490           The Extended Industry Standard Architecture (EISA) bus was
2491           developed as an open alternative to the IBM MicroChannel bus.
2492 
2493           The EISA bus provided some of the features of the IBM MicroChannel
2494           bus while maintaining backward compatibility with cards made for
2495           the older ISA bus.  The EISA bus saw limited use between 1988 and
2496           1995 when it was made obsolete by the PCI bus.
2497 
2498           Say Y here if you are building a kernel for an EISA-based machine.
2499 
2500           Otherwise, say N.
2501 
2502 source "drivers/eisa/Kconfig"
2503 
2504 config SCx200
2505         tristate "NatSemi SCx200 support"
2506         ---help---
2507           This provides basic support for National Semiconductor's
2508           (now AMD's) Geode processors.  The driver probes for the
2509           PCI-IDs of several on-chip devices, so its a good dependency
2510           for other scx200_* drivers.
2511 
2512           If compiled as a module, the driver is named scx200.
2513 
2514 config SCx200HR_TIMER
2515         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2516         depends on SCx200
2517         default y
2518         ---help---
2519           This driver provides a clocksource built upon the on-chip
2520           27MHz high-resolution timer.  Its also a workaround for
2521           NSC Geode SC-1100's buggy TSC, which loses time when the
2522           processor goes idle (as is done by the scheduler).  The
2523           other workaround is idle=poll boot option.
2524 
2525 config OLPC
2526         bool "One Laptop Per Child support"
2527         depends on !X86_PAE
2528         select GPIOLIB
2529         select OF
2530         select OF_PROMTREE
2531         select IRQ_DOMAIN
2532         ---help---
2533           Add support for detecting the unique features of the OLPC
2534           XO hardware.
2535 
2536 config OLPC_XO1_PM
2537         bool "OLPC XO-1 Power Management"
2538         depends on OLPC && MFD_CS5535 && PM_SLEEP
2539         select MFD_CORE
2540         ---help---
2541           Add support for poweroff and suspend of the OLPC XO-1 laptop.
2542 
2543 config OLPC_XO1_RTC
2544         bool "OLPC XO-1 Real Time Clock"
2545         depends on OLPC_XO1_PM && RTC_DRV_CMOS
2546         ---help---
2547           Add support for the XO-1 real time clock, which can be used as a
2548           programmable wakeup source.
2549 
2550 config OLPC_XO1_SCI
2551         bool "OLPC XO-1 SCI extras"
2552         depends on OLPC && OLPC_XO1_PM
2553         depends on INPUT=y
2554         select POWER_SUPPLY
2555         select GPIO_CS5535
2556         select MFD_CORE
2557         ---help---
2558           Add support for SCI-based features of the OLPC XO-1 laptop:
2559            - EC-driven system wakeups
2560            - Power button
2561            - Ebook switch
2562            - Lid switch
2563            - AC adapter status updates
2564            - Battery status updates
2565 
2566 config OLPC_XO15_SCI
2567         bool "OLPC XO-1.5 SCI extras"
2568         depends on OLPC && ACPI
2569         select POWER_SUPPLY
2570         ---help---
2571           Add support for SCI-based features of the OLPC XO-1.5 laptop:
2572            - EC-driven system wakeups
2573            - AC adapter status updates
2574            - Battery status updates
2575 
2576 config ALIX
2577         bool "PCEngines ALIX System Support (LED setup)"
2578         select GPIOLIB
2579         ---help---
2580           This option enables system support for the PCEngines ALIX.
2581           At present this just sets up LEDs for GPIO control on
2582           ALIX2/3/6 boards.  However, other system specific setup should
2583           get added here.
2584 
2585           Note: You must still enable the drivers for GPIO and LED support
2586           (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2587 
2588           Note: You have to set alix.force=1 for boards with Award BIOS.
2589 
2590 config NET5501
2591         bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2592         select GPIOLIB
2593         ---help---
2594           This option enables system support for the Soekris Engineering net5501.
2595 
2596 config GEOS
2597         bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2598         select GPIOLIB
2599         depends on DMI
2600         ---help---
2601           This option enables system support for the Traverse Technologies GEOS.
2602 
2603 config TS5500
2604         bool "Technologic Systems TS-5500 platform support"
2605         depends on MELAN
2606         select CHECK_SIGNATURE
2607         select NEW_LEDS
2608         select LEDS_CLASS
2609         ---help---
2610           This option enables system support for the Technologic Systems TS-5500.
2611 
2612 endif # X86_32
2613 
2614 config AMD_NB
2615         def_bool y
2616         depends on CPU_SUP_AMD && PCI
2617 
2618 source "drivers/pcmcia/Kconfig"
2619 
2620 config RAPIDIO
2621         tristate "RapidIO support"
2622         depends on PCI
2623         default n
2624         help
2625           If enabled this option will include drivers and the core
2626           infrastructure code to support RapidIO interconnect devices.
2627 
2628 source "drivers/rapidio/Kconfig"
2629 
2630 config X86_SYSFB
2631         bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2632         help
2633           Firmwares often provide initial graphics framebuffers so the BIOS,
2634           bootloader or kernel can show basic video-output during boot for
2635           user-guidance and debugging. Historically, x86 used the VESA BIOS
2636           Extensions and EFI-framebuffers for this, which are mostly limited
2637           to x86.
2638           This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2639           framebuffers so the new generic system-framebuffer drivers can be
2640           used on x86. If the framebuffer is not compatible with the generic
2641           modes, it is adverticed as fallback platform framebuffer so legacy
2642           drivers like efifb, vesafb and uvesafb can pick it up.
2643           If this option is not selected, all system framebuffers are always
2644           marked as fallback platform framebuffers as usual.
2645 
2646           Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2647           not be able to pick up generic system framebuffers if this option
2648           is selected. You are highly encouraged to enable simplefb as
2649           replacement if you select this option. simplefb can correctly deal
2650           with generic system framebuffers. But you should still keep vesafb
2651           and others enabled as fallback if a system framebuffer is
2652           incompatible with simplefb.
2653 
2654           If unsure, say Y.
2655 
2656 endmenu
2657 
2658 
2659 menu "Executable file formats / Emulations"
2660 
2661 source "fs/Kconfig.binfmt"
2662 
2663 config IA32_EMULATION
2664         bool "IA32 Emulation"
2665         depends on X86_64
2666         select BINFMT_ELF
2667         select COMPAT_BINFMT_ELF
2668         select ARCH_WANT_OLD_COMPAT_IPC
2669         ---help---
2670           Include code to run legacy 32-bit programs under a
2671           64-bit kernel. You should likely turn this on, unless you're
2672           100% sure that you don't have any 32-bit programs left.
2673 
2674 config IA32_AOUT
2675         tristate "IA32 a.out support"
2676         depends on IA32_EMULATION
2677         ---help---
2678           Support old a.out binaries in the 32bit emulation.
2679 
2680 config X86_X32
2681         bool "x32 ABI for 64-bit mode"
2682         depends on X86_64
2683         ---help---
2684           Include code to run binaries for the x32 native 32-bit ABI
2685           for 64-bit processors.  An x32 process gets access to the
2686           full 64-bit register file and wide data path while leaving
2687           pointers at 32 bits for smaller memory footprint.
2688 
2689           You will need a recent binutils (2.22 or later) with
2690           elf32_x86_64 support enabled to compile a kernel with this
2691           option set.
2692 
2693 config COMPAT
2694         def_bool y
2695         depends on IA32_EMULATION || X86_X32
2696 
2697 if COMPAT
2698 config COMPAT_FOR_U64_ALIGNMENT
2699         def_bool y
2700 
2701 config SYSVIPC_COMPAT
2702         def_bool y
2703         depends on SYSVIPC
2704 
2705 config KEYS_COMPAT
2706         def_bool y
2707         depends on KEYS
2708 endif
2709 
2710 endmenu
2711 
2712 
2713 config HAVE_ATOMIC_IOMAP
2714         def_bool y
2715         depends on X86_32
2716 
2717 config X86_DEV_DMA_OPS
2718         bool
2719         depends on X86_64 || STA2X11
2720 
2721 config X86_DMA_REMAP
2722         bool
2723         depends on STA2X11
2724 
2725 config PMC_ATOM
2726         def_bool y
2727         depends on PCI
2728 
2729 config VMD
2730         depends on PCI_MSI
2731         tristate "Volume Management Device Driver"
2732         default N
2733         ---help---
2734           Adds support for the Intel Volume Management Device (VMD). VMD is a
2735           secondary PCI host bridge that allows PCI Express root ports,
2736           and devices attached to them, to be removed from the default
2737           PCI domain and placed within the VMD domain. This provides
2738           more bus resources than are otherwise possible with a
2739           single domain. If you know your system provides one of these and
2740           has devices attached to it, say Y; if you are not sure, say N.
2741 
2742 source "net/Kconfig"
2743 
2744 source "drivers/Kconfig"
2745 
2746 source "drivers/firmware/Kconfig"
2747 
2748 source "fs/Kconfig"
2749 
2750 source "arch/x86/Kconfig.debug"
2751 
2752 source "security/Kconfig"
2753 
2754 source "crypto/Kconfig"
2755 
2756 source "arch/x86/kvm/Kconfig"
2757 
2758 source "lib/Kconfig"

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us