xref: /linux/arch/x86/Kconfig (revision 7744ccdbc16f0ac4adae21b3678af93775b3a386)
1# Select 32 or 64 bit
2config 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
9config X86_32
10	def_bool y
11	depends on !64BIT
12	# Options that are inherently 32-bit kernel only:
13	select ARCH_WANT_IPC_PARSE_VERSION
14	select CLKSRC_I8253
15	select CLONE_BACKWARDS
16	select HAVE_AOUT
17	select HAVE_GENERIC_DMA_COHERENT
18	select MODULES_USE_ELF_REL
19	select OLD_SIGACTION
20
21config X86_64
22	def_bool y
23	depends on 64BIT
24	# Options that are inherently 64-bit kernel only:
25	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
26	select ARCH_SUPPORTS_INT128
27	select ARCH_USE_CMPXCHG_LOCKREF
28	select HAVE_ARCH_SOFT_DIRTY
29	select MODULES_USE_ELF_RELA
30	select X86_DEV_DMA_OPS
31
32#
33# Arch settings
34#
35# ( Note that options that are marked 'if X86_64' could in principle be
36#   ported to 32-bit as well. )
37#
38config X86
39	def_bool y
40	#
41	# Note: keep this list sorted alphabetically
42	#
43	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
44	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
45	select ANON_INODES
46	select ARCH_CLOCKSOURCE_DATA
47	select ARCH_DISCARD_MEMBLOCK
48	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
49	select ARCH_HAS_DEBUG_VIRTUAL
50	select ARCH_HAS_DEVMEM_IS_ALLOWED
51	select ARCH_HAS_ELF_RANDOMIZE
52	select ARCH_HAS_FAST_MULTIPLIER
53	select ARCH_HAS_FORTIFY_SOURCE
54	select ARCH_HAS_GCOV_PROFILE_ALL
55	select ARCH_HAS_KCOV			if X86_64
56	select ARCH_HAS_MMIO_FLUSH
57	select ARCH_HAS_PMEM_API		if X86_64
58	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
59	select ARCH_HAS_SET_MEMORY
60	select ARCH_HAS_SG_CHAIN
61	select ARCH_HAS_STRICT_KERNEL_RWX
62	select ARCH_HAS_STRICT_MODULE_RWX
63	select ARCH_HAS_UBSAN_SANITIZE_ALL
64	select ARCH_HAS_ZONE_DEVICE		if X86_64
65	select ARCH_HAVE_NMI_SAFE_CMPXCHG
66	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
67	select ARCH_MIGHT_HAVE_PC_PARPORT
68	select ARCH_MIGHT_HAVE_PC_SERIO
69	select ARCH_SUPPORTS_ATOMIC_RMW
70	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
71	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
72	select ARCH_USE_BUILTIN_BSWAP
73	select ARCH_USE_QUEUED_RWLOCKS
74	select ARCH_USE_QUEUED_SPINLOCKS
75	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
76	select ARCH_WANT_FRAME_POINTERS
77	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
78	select ARCH_WANTS_THP_SWAP		if X86_64
79	select BUILDTIME_EXTABLE_SORT
80	select CLKEVT_I8253
81	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
82	select CLOCKSOURCE_WATCHDOG
83	select DCACHE_WORD_ACCESS
84	select EDAC_ATOMIC_SCRUB
85	select EDAC_SUPPORT
86	select GENERIC_CLOCKEVENTS
87	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
88	select GENERIC_CLOCKEVENTS_MIN_ADJUST
89	select GENERIC_CMOS_UPDATE
90	select GENERIC_CPU_AUTOPROBE
91	select GENERIC_EARLY_IOREMAP
92	select GENERIC_FIND_FIRST_BIT
93	select GENERIC_IOMAP
94	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
95	select GENERIC_IRQ_MIGRATION		if SMP
96	select GENERIC_IRQ_PROBE
97	select GENERIC_IRQ_SHOW
98	select GENERIC_PENDING_IRQ		if SMP
99	select GENERIC_SMP_IDLE_THREAD
100	select GENERIC_STRNCPY_FROM_USER
101	select GENERIC_STRNLEN_USER
102	select GENERIC_TIME_VSYSCALL
103	select HAVE_ACPI_APEI			if ACPI
104	select HAVE_ACPI_APEI_NMI		if ACPI
105	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
106	select HAVE_ARCH_AUDITSYSCALL
107	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
108	select HAVE_ARCH_JUMP_LABEL
109	select HAVE_ARCH_KASAN			if X86_64 && SPARSEMEM_VMEMMAP
110	select HAVE_ARCH_KGDB
111	select HAVE_ARCH_KMEMCHECK
112	select HAVE_ARCH_MMAP_RND_BITS		if MMU
113	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
114	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
115	select HAVE_ARCH_SECCOMP_FILTER
116	select HAVE_ARCH_TRACEHOOK
117	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
118	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
119	select HAVE_ARCH_VMAP_STACK		if X86_64
120	select HAVE_ARCH_WITHIN_STACK_FRAMES
121	select HAVE_CC_STACKPROTECTOR
122	select HAVE_CMPXCHG_DOUBLE
123	select HAVE_CMPXCHG_LOCAL
124	select HAVE_CONTEXT_TRACKING		if X86_64
125	select HAVE_COPY_THREAD_TLS
126	select HAVE_C_RECORDMCOUNT
127	select HAVE_DEBUG_KMEMLEAK
128	select HAVE_DEBUG_STACKOVERFLOW
129	select HAVE_DMA_API_DEBUG
130	select HAVE_DMA_CONTIGUOUS
131	select HAVE_DYNAMIC_FTRACE
132	select HAVE_DYNAMIC_FTRACE_WITH_REGS
133	select HAVE_EBPF_JIT			if X86_64
134	select HAVE_EFFICIENT_UNALIGNED_ACCESS
135	select HAVE_EXIT_THREAD
136	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
137	select HAVE_FTRACE_MCOUNT_RECORD
138	select HAVE_FUNCTION_GRAPH_TRACER
139	select HAVE_FUNCTION_TRACER
140	select HAVE_GCC_PLUGINS
141	select HAVE_HW_BREAKPOINT
142	select HAVE_IDE
143	select HAVE_IOREMAP_PROT
144	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
145	select HAVE_IRQ_TIME_ACCOUNTING
146	select HAVE_KERNEL_BZIP2
147	select HAVE_KERNEL_GZIP
148	select HAVE_KERNEL_LZ4
149	select HAVE_KERNEL_LZMA
150	select HAVE_KERNEL_LZO
151	select HAVE_KERNEL_XZ
152	select HAVE_KPROBES
153	select HAVE_KPROBES_ON_FTRACE
154	select HAVE_KRETPROBES
155	select HAVE_KVM
156	select HAVE_LIVEPATCH			if X86_64
157	select HAVE_MEMBLOCK
158	select HAVE_MEMBLOCK_NODE_MAP
159	select HAVE_MIXED_BREAKPOINTS_REGS
160	select HAVE_NMI
161	select HAVE_OPROFILE
162	select HAVE_OPTPROBES
163	select HAVE_PCSPKR_PLATFORM
164	select HAVE_PERF_EVENTS
165	select HAVE_PERF_EVENTS_NMI
166	select HAVE_HARDLOCKUP_DETECTOR_PERF	if HAVE_PERF_EVENTS_NMI
167	select HAVE_PERF_REGS
168	select HAVE_PERF_USER_STACK_DUMP
169	select HAVE_REGS_AND_STACK_ACCESS_API
170	select HAVE_RELIABLE_STACKTRACE		if X86_64 && FRAME_POINTER && STACK_VALIDATION
171	select HAVE_STACK_VALIDATION		if X86_64
172	select HAVE_SYSCALL_TRACEPOINTS
173	select HAVE_UNSTABLE_SCHED_CLOCK
174	select HAVE_USER_RETURN_NOTIFIER
175	select IRQ_FORCED_THREADING
176	select PCI_LOCKLESS_CONFIG
177	select PERF_EVENTS
178	select RTC_LIB
179	select RTC_MC146818_LIB
180	select SPARSE_IRQ
181	select SRCU
182	select SYSCTL_EXCEPTION_TRACE
183	select THREAD_INFO_IN_TASK
184	select USER_STACKTRACE_SUPPORT
185	select VIRT_TO_BUS
186	select X86_FEATURE_NAMES		if PROC_FS
187
188config INSTRUCTION_DECODER
189	def_bool y
190	depends on KPROBES || PERF_EVENTS || UPROBES
191
192config OUTPUT_FORMAT
193	string
194	default "elf32-i386" if X86_32
195	default "elf64-x86-64" if X86_64
196
197config ARCH_DEFCONFIG
198	string
199	default "arch/x86/configs/i386_defconfig" if X86_32
200	default "arch/x86/configs/x86_64_defconfig" if X86_64
201
202config LOCKDEP_SUPPORT
203	def_bool y
204
205config STACKTRACE_SUPPORT
206	def_bool y
207
208config MMU
209	def_bool y
210
211config ARCH_MMAP_RND_BITS_MIN
212	default 28 if 64BIT
213	default 8
214
215config ARCH_MMAP_RND_BITS_MAX
216	default 32 if 64BIT
217	default 16
218
219config ARCH_MMAP_RND_COMPAT_BITS_MIN
220	default 8
221
222config ARCH_MMAP_RND_COMPAT_BITS_MAX
223	default 16
224
225config SBUS
226	bool
227
228config NEED_DMA_MAP_STATE
229	def_bool y
230	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
231
232config NEED_SG_DMA_LENGTH
233	def_bool y
234
235config GENERIC_ISA_DMA
236	def_bool y
237	depends on ISA_DMA_API
238
239config GENERIC_BUG
240	def_bool y
241	depends on BUG
242	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
243
244config GENERIC_BUG_RELATIVE_POINTERS
245	bool
246
247config GENERIC_HWEIGHT
248	def_bool y
249
250config ARCH_MAY_HAVE_PC_FDC
251	def_bool y
252	depends on ISA_DMA_API
253
254config RWSEM_XCHGADD_ALGORITHM
255	def_bool y
256
257config GENERIC_CALIBRATE_DELAY
258	def_bool y
259
260config ARCH_HAS_CPU_RELAX
261	def_bool y
262
263config ARCH_HAS_CACHE_LINE_SIZE
264	def_bool y
265
266config HAVE_SETUP_PER_CPU_AREA
267	def_bool y
268
269config NEED_PER_CPU_EMBED_FIRST_CHUNK
270	def_bool y
271
272config NEED_PER_CPU_PAGE_FIRST_CHUNK
273	def_bool y
274
275config ARCH_HIBERNATION_POSSIBLE
276	def_bool y
277
278config ARCH_SUSPEND_POSSIBLE
279	def_bool y
280
281config ARCH_WANT_HUGE_PMD_SHARE
282	def_bool y
283
284config ARCH_WANT_GENERAL_HUGETLB
285	def_bool y
286
287config ZONE_DMA32
288	def_bool y if X86_64
289
290config AUDIT_ARCH
291	def_bool y if X86_64
292
293config ARCH_SUPPORTS_OPTIMIZED_INLINING
294	def_bool y
295
296config ARCH_SUPPORTS_DEBUG_PAGEALLOC
297	def_bool y
298
299config KASAN_SHADOW_OFFSET
300	hex
301	depends on KASAN
302	default 0xdff8000000000000 if X86_5LEVEL
303	default 0xdffffc0000000000
304
305config HAVE_INTEL_TXT
306	def_bool y
307	depends on INTEL_IOMMU && ACPI
308
309config X86_32_SMP
310	def_bool y
311	depends on X86_32 && SMP
312
313config X86_64_SMP
314	def_bool y
315	depends on X86_64 && SMP
316
317config X86_32_LAZY_GS
318	def_bool y
319	depends on X86_32 && !CC_STACKPROTECTOR
320
321config ARCH_SUPPORTS_UPROBES
322	def_bool y
323
324config FIX_EARLYCON_MEM
325	def_bool y
326
327config PGTABLE_LEVELS
328	int
329	default 4 if X86_64
330	default 3 if X86_PAE
331	default 2
332
333source "init/Kconfig"
334source "kernel/Kconfig.freezer"
335
336menu "Processor type and features"
337
338config ZONE_DMA
339	bool "DMA memory allocation support" if EXPERT
340	default y
341	help
342	  DMA memory allocation support allows devices with less than 32-bit
343	  addressing to allocate within the first 16MB of address space.
344	  Disable if no such devices will be used.
345
346	  If unsure, say Y.
347
348config SMP
349	bool "Symmetric multi-processing support"
350	---help---
351	  This enables support for systems with more than one CPU. If you have
352	  a system with only one CPU, say N. If you have a system with more
353	  than one CPU, say Y.
354
355	  If you say N here, the kernel will run on uni- and multiprocessor
356	  machines, but will use only one CPU of a multiprocessor machine. If
357	  you say Y here, the kernel will run on many, but not all,
358	  uniprocessor machines. On a uniprocessor machine, the kernel
359	  will run faster if you say N here.
360
361	  Note that if you say Y here and choose architecture "586" or
362	  "Pentium" under "Processor family", the kernel will not work on 486
363	  architectures. Similarly, multiprocessor kernels for the "PPro"
364	  architecture may not work on all Pentium based boards.
365
366	  People using multiprocessor machines who say Y here should also say
367	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
368	  Management" code will be disabled if you say Y here.
369
370	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
371	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
372	  <http://www.tldp.org/docs.html#howto>.
373
374	  If you don't know what to do here, say N.
375
376config X86_FEATURE_NAMES
377	bool "Processor feature human-readable names" if EMBEDDED
378	default y
379	---help---
380	  This option compiles in a table of x86 feature bits and corresponding
381	  names.  This is required to support /proc/cpuinfo and a few kernel
382	  messages.  You can disable this to save space, at the expense of
383	  making those few kernel messages show numeric feature bits instead.
384
385	  If in doubt, say Y.
386
387config X86_FAST_FEATURE_TESTS
388	bool "Fast CPU feature tests" if EMBEDDED
389	default y
390	---help---
391	  Some fast-paths in the kernel depend on the capabilities of the CPU.
392	  Say Y here for the kernel to patch in the appropriate code at runtime
393	  based on the capabilities of the CPU. The infrastructure for patching
394	  code at runtime takes up some additional space; space-constrained
395	  embedded systems may wish to say N here to produce smaller, slightly
396	  slower code.
397
398config X86_X2APIC
399	bool "Support x2apic"
400	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
401	---help---
402	  This enables x2apic support on CPUs that have this feature.
403
404	  This allows 32-bit apic IDs (so it can support very large systems),
405	  and accesses the local apic via MSRs not via mmio.
406
407	  If you don't know what to do here, say N.
408
409config X86_MPPARSE
410	bool "Enable MPS table" if ACPI || SFI
411	default y
412	depends on X86_LOCAL_APIC
413	---help---
414	  For old smp systems that do not have proper acpi support. Newer systems
415	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
416
417config X86_BIGSMP
418	bool "Support for big SMP systems with more than 8 CPUs"
419	depends on X86_32 && SMP
420	---help---
421	  This option is needed for the systems that have more than 8 CPUs
422
423config GOLDFISH
424       def_bool y
425       depends on X86_GOLDFISH
426
427config INTEL_RDT_A
428	bool "Intel Resource Director Technology Allocation support"
429	default n
430	depends on X86 && CPU_SUP_INTEL
431	select KERNFS
432	help
433	  Select to enable resource allocation which is a sub-feature of
434	  Intel Resource Director Technology(RDT). More information about
435	  RDT can be found in the Intel x86 Architecture Software
436	  Developer Manual.
437
438	  Say N if unsure.
439
440if X86_32
441config X86_EXTENDED_PLATFORM
442	bool "Support for extended (non-PC) x86 platforms"
443	default y
444	---help---
445	  If you disable this option then the kernel will only support
446	  standard PC platforms. (which covers the vast majority of
447	  systems out there.)
448
449	  If you enable this option then you'll be able to select support
450	  for the following (non-PC) 32 bit x86 platforms:
451		Goldfish (Android emulator)
452		AMD Elan
453		RDC R-321x SoC
454		SGI 320/540 (Visual Workstation)
455		STA2X11-based (e.g. Northville)
456		Moorestown MID devices
457
458	  If you have one of these systems, or if you want to build a
459	  generic distribution kernel, say Y here - otherwise say N.
460endif
461
462if X86_64
463config X86_EXTENDED_PLATFORM
464	bool "Support for extended (non-PC) x86 platforms"
465	default y
466	---help---
467	  If you disable this option then the kernel will only support
468	  standard PC platforms. (which covers the vast majority of
469	  systems out there.)
470
471	  If you enable this option then you'll be able to select support
472	  for the following (non-PC) 64 bit x86 platforms:
473		Numascale NumaChip
474		ScaleMP vSMP
475		SGI Ultraviolet
476
477	  If you have one of these systems, or if you want to build a
478	  generic distribution kernel, say Y here - otherwise say N.
479endif
480# This is an alphabetically sorted list of 64 bit extended platforms
481# Please maintain the alphabetic order if and when there are additions
482config X86_NUMACHIP
483	bool "Numascale NumaChip"
484	depends on X86_64
485	depends on X86_EXTENDED_PLATFORM
486	depends on NUMA
487	depends on SMP
488	depends on X86_X2APIC
489	depends on PCI_MMCONFIG
490	---help---
491	  Adds support for Numascale NumaChip large-SMP systems. Needed to
492	  enable more than ~168 cores.
493	  If you don't have one of these, you should say N here.
494
495config X86_VSMP
496	bool "ScaleMP vSMP"
497	select HYPERVISOR_GUEST
498	select PARAVIRT
499	depends on X86_64 && PCI
500	depends on X86_EXTENDED_PLATFORM
501	depends on SMP
502	---help---
503	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
504	  supposed to run on these EM64T-based machines.  Only choose this option
505	  if you have one of these machines.
506
507config X86_UV
508	bool "SGI Ultraviolet"
509	depends on X86_64
510	depends on X86_EXTENDED_PLATFORM
511	depends on NUMA
512	depends on EFI
513	depends on X86_X2APIC
514	depends on PCI
515	---help---
516	  This option is needed in order to support SGI Ultraviolet systems.
517	  If you don't have one of these, you should say N here.
518
519# Following is an alphabetically sorted list of 32 bit extended platforms
520# Please maintain the alphabetic order if and when there are additions
521
522config X86_GOLDFISH
523       bool "Goldfish (Virtual Platform)"
524       depends on X86_EXTENDED_PLATFORM
525       ---help---
526	 Enable support for the Goldfish virtual platform used primarily
527	 for Android development. Unless you are building for the Android
528	 Goldfish emulator say N here.
529
530config X86_INTEL_CE
531	bool "CE4100 TV platform"
532	depends on PCI
533	depends on PCI_GODIRECT
534	depends on X86_IO_APIC
535	depends on X86_32
536	depends on X86_EXTENDED_PLATFORM
537	select X86_REBOOTFIXUPS
538	select OF
539	select OF_EARLY_FLATTREE
540	---help---
541	  Select for the Intel CE media processor (CE4100) SOC.
542	  This option compiles in support for the CE4100 SOC for settop
543	  boxes and media devices.
544
545config X86_INTEL_MID
546	bool "Intel MID platform support"
547	depends on X86_EXTENDED_PLATFORM
548	depends on X86_PLATFORM_DEVICES
549	depends on PCI
550	depends on X86_64 || (PCI_GOANY && X86_32)
551	depends on X86_IO_APIC
552	select SFI
553	select I2C
554	select DW_APB_TIMER
555	select APB_TIMER
556	select INTEL_SCU_IPC
557	select MFD_INTEL_MSIC
558	---help---
559	  Select to build a kernel capable of supporting Intel MID (Mobile
560	  Internet Device) platform systems which do not have the PCI legacy
561	  interfaces. If you are building for a PC class system say N here.
562
563	  Intel MID platforms are based on an Intel processor and chipset which
564	  consume less power than most of the x86 derivatives.
565
566config X86_INTEL_QUARK
567	bool "Intel Quark platform support"
568	depends on X86_32
569	depends on X86_EXTENDED_PLATFORM
570	depends on X86_PLATFORM_DEVICES
571	depends on X86_TSC
572	depends on PCI
573	depends on PCI_GOANY
574	depends on X86_IO_APIC
575	select IOSF_MBI
576	select INTEL_IMR
577	select COMMON_CLK
578	---help---
579	  Select to include support for Quark X1000 SoC.
580	  Say Y here if you have a Quark based system such as the Arduino
581	  compatible Intel Galileo.
582
583config X86_INTEL_LPSS
584	bool "Intel Low Power Subsystem Support"
585	depends on X86 && ACPI
586	select COMMON_CLK
587	select PINCTRL
588	select IOSF_MBI
589	---help---
590	  Select to build support for Intel Low Power Subsystem such as
591	  found on Intel Lynxpoint PCH. Selecting this option enables
592	  things like clock tree (common clock framework) and pincontrol
593	  which are needed by the LPSS peripheral drivers.
594
595config X86_AMD_PLATFORM_DEVICE
596	bool "AMD ACPI2Platform devices support"
597	depends on ACPI
598	select COMMON_CLK
599	select PINCTRL
600	---help---
601	  Select to interpret AMD specific ACPI device to platform device
602	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
603	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
604	  implemented under PINCTRL subsystem.
605
606config IOSF_MBI
607	tristate "Intel SoC IOSF Sideband support for SoC platforms"
608	depends on PCI
609	---help---
610	  This option enables sideband register access support for Intel SoC
611	  platforms. On these platforms the IOSF sideband is used in lieu of
612	  MSR's for some register accesses, mostly but not limited to thermal
613	  and power. Drivers may query the availability of this device to
614	  determine if they need the sideband in order to work on these
615	  platforms. The sideband is available on the following SoC products.
616	  This list is not meant to be exclusive.
617	   - BayTrail
618	   - Braswell
619	   - Quark
620
621	  You should say Y if you are running a kernel on one of these SoC's.
622
623config IOSF_MBI_DEBUG
624	bool "Enable IOSF sideband access through debugfs"
625	depends on IOSF_MBI && DEBUG_FS
626	---help---
627	  Select this option to expose the IOSF sideband access registers (MCR,
628	  MDR, MCRX) through debugfs to write and read register information from
629	  different units on the SoC. This is most useful for obtaining device
630	  state information for debug and analysis. As this is a general access
631	  mechanism, users of this option would have specific knowledge of the
632	  device they want to access.
633
634	  If you don't require the option or are in doubt, say N.
635
636config X86_RDC321X
637	bool "RDC R-321x SoC"
638	depends on X86_32
639	depends on X86_EXTENDED_PLATFORM
640	select M486
641	select X86_REBOOTFIXUPS
642	---help---
643	  This option is needed for RDC R-321x system-on-chip, also known
644	  as R-8610-(G).
645	  If you don't have one of these chips, you should say N here.
646
647config X86_32_NON_STANDARD
648	bool "Support non-standard 32-bit SMP architectures"
649	depends on X86_32 && SMP
650	depends on X86_EXTENDED_PLATFORM
651	---help---
652	  This option compiles in the bigsmp and STA2X11 default
653	  subarchitectures.  It is intended for a generic binary
654	  kernel. If you select them all, kernel will probe it one by
655	  one and will fallback to default.
656
657# Alphabetically sorted list of Non standard 32 bit platforms
658
659config X86_SUPPORTS_MEMORY_FAILURE
660	def_bool y
661	# MCE code calls memory_failure():
662	depends on X86_MCE
663	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
664	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
665	depends on X86_64 || !SPARSEMEM
666	select ARCH_SUPPORTS_MEMORY_FAILURE
667
668config STA2X11
669	bool "STA2X11 Companion Chip Support"
670	depends on X86_32_NON_STANDARD && PCI
671	select X86_DEV_DMA_OPS
672	select X86_DMA_REMAP
673	select SWIOTLB
674	select MFD_STA2X11
675	select GPIOLIB
676	default n
677	---help---
678	  This adds support for boards based on the STA2X11 IO-Hub,
679	  a.k.a. "ConneXt". The chip is used in place of the standard
680	  PC chipset, so all "standard" peripherals are missing. If this
681	  option is selected the kernel will still be able to boot on
682	  standard PC machines.
683
684config X86_32_IRIS
685	tristate "Eurobraille/Iris poweroff module"
686	depends on X86_32
687	---help---
688	  The Iris machines from EuroBraille do not have APM or ACPI support
689	  to shut themselves down properly.  A special I/O sequence is
690	  needed to do so, which is what this module does at
691	  kernel shutdown.
692
693	  This is only for Iris machines from EuroBraille.
694
695	  If unused, say N.
696
697config SCHED_OMIT_FRAME_POINTER
698	def_bool y
699	prompt "Single-depth WCHAN output"
700	depends on X86
701	---help---
702	  Calculate simpler /proc/<PID>/wchan values. If this option
703	  is disabled then wchan values will recurse back to the
704	  caller function. This provides more accurate wchan values,
705	  at the expense of slightly more scheduling overhead.
706
707	  If in doubt, say "Y".
708
709menuconfig HYPERVISOR_GUEST
710	bool "Linux guest support"
711	---help---
712	  Say Y here to enable options for running Linux under various hyper-
713	  visors. This option enables basic hypervisor detection and platform
714	  setup.
715
716	  If you say N, all options in this submenu will be skipped and
717	  disabled, and Linux guest support won't be built in.
718
719if HYPERVISOR_GUEST
720
721config PARAVIRT
722	bool "Enable paravirtualization code"
723	---help---
724	  This changes the kernel so it can modify itself when it is run
725	  under a hypervisor, potentially improving performance significantly
726	  over full virtualization.  However, when run without a hypervisor
727	  the kernel is theoretically slower and slightly larger.
728
729config PARAVIRT_DEBUG
730	bool "paravirt-ops debugging"
731	depends on PARAVIRT && DEBUG_KERNEL
732	---help---
733	  Enable to debug paravirt_ops internals.  Specifically, BUG if
734	  a paravirt_op is missing when it is called.
735
736config PARAVIRT_SPINLOCKS
737	bool "Paravirtualization layer for spinlocks"
738	depends on PARAVIRT && SMP
739	---help---
740	  Paravirtualized spinlocks allow a pvops backend to replace the
741	  spinlock implementation with something virtualization-friendly
742	  (for example, block the virtual CPU rather than spinning).
743
744	  It has a minimal impact on native kernels and gives a nice performance
745	  benefit on paravirtualized KVM / Xen kernels.
746
747	  If you are unsure how to answer this question, answer Y.
748
749config QUEUED_LOCK_STAT
750	bool "Paravirt queued spinlock statistics"
751	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
752	---help---
753	  Enable the collection of statistical data on the slowpath
754	  behavior of paravirtualized queued spinlocks and report
755	  them on debugfs.
756
757source "arch/x86/xen/Kconfig"
758
759config KVM_GUEST
760	bool "KVM Guest support (including kvmclock)"
761	depends on PARAVIRT
762	select PARAVIRT_CLOCK
763	default y
764	---help---
765	  This option enables various optimizations for running under the KVM
766	  hypervisor. It includes a paravirtualized clock, so that instead
767	  of relying on a PIT (or probably other) emulation by the
768	  underlying device model, the host provides the guest with
769	  timing infrastructure such as time of day, and system time
770
771config KVM_DEBUG_FS
772	bool "Enable debug information for KVM Guests in debugfs"
773	depends on KVM_GUEST && DEBUG_FS
774	default n
775	---help---
776	  This option enables collection of various statistics for KVM guest.
777	  Statistics are displayed in debugfs filesystem. Enabling this option
778	  may incur significant overhead.
779
780source "arch/x86/lguest/Kconfig"
781
782config PARAVIRT_TIME_ACCOUNTING
783	bool "Paravirtual steal time accounting"
784	depends on PARAVIRT
785	default n
786	---help---
787	  Select this option to enable fine granularity task steal time
788	  accounting. Time spent executing other tasks in parallel with
789	  the current vCPU is discounted from the vCPU power. To account for
790	  that, there can be a small performance impact.
791
792	  If in doubt, say N here.
793
794config PARAVIRT_CLOCK
795	bool
796
797endif #HYPERVISOR_GUEST
798
799config NO_BOOTMEM
800	def_bool y
801
802source "arch/x86/Kconfig.cpu"
803
804config HPET_TIMER
805	def_bool X86_64
806	prompt "HPET Timer Support" if X86_32
807	---help---
808	  Use the IA-PC HPET (High Precision Event Timer) to manage
809	  time in preference to the PIT and RTC, if a HPET is
810	  present.
811	  HPET is the next generation timer replacing legacy 8254s.
812	  The HPET provides a stable time base on SMP
813	  systems, unlike the TSC, but it is more expensive to access,
814	  as it is off-chip.  The interface used is documented
815	  in the HPET spec, revision 1.
816
817	  You can safely choose Y here.  However, HPET will only be
818	  activated if the platform and the BIOS support this feature.
819	  Otherwise the 8254 will be used for timing services.
820
821	  Choose N to continue using the legacy 8254 timer.
822
823config HPET_EMULATE_RTC
824	def_bool y
825	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
826
827config APB_TIMER
828       def_bool y if X86_INTEL_MID
829       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
830       select DW_APB_TIMER
831       depends on X86_INTEL_MID && SFI
832       help
833         APB timer is the replacement for 8254, HPET on X86 MID platforms.
834         The APBT provides a stable time base on SMP
835         systems, unlike the TSC, but it is more expensive to access,
836         as it is off-chip. APB timers are always running regardless of CPU
837         C states, they are used as per CPU clockevent device when possible.
838
839# Mark as expert because too many people got it wrong.
840# The code disables itself when not needed.
841config DMI
842	default y
843	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
844	bool "Enable DMI scanning" if EXPERT
845	---help---
846	  Enabled scanning of DMI to identify machine quirks. Say Y
847	  here unless you have verified that your setup is not
848	  affected by entries in the DMI blacklist. Required by PNP
849	  BIOS code.
850
851config GART_IOMMU
852	bool "Old AMD GART IOMMU support"
853	select SWIOTLB
854	depends on X86_64 && PCI && AMD_NB
855	---help---
856	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
857	  GART based hardware IOMMUs.
858
859	  The GART supports full DMA access for devices with 32-bit access
860	  limitations, on systems with more than 3 GB. This is usually needed
861	  for USB, sound, many IDE/SATA chipsets and some other devices.
862
863	  Newer systems typically have a modern AMD IOMMU, supported via
864	  the CONFIG_AMD_IOMMU=y config option.
865
866	  In normal configurations this driver is only active when needed:
867	  there's more than 3 GB of memory and the system contains a
868	  32-bit limited device.
869
870	  If unsure, say Y.
871
872config CALGARY_IOMMU
873	bool "IBM Calgary IOMMU support"
874	select SWIOTLB
875	depends on X86_64 && PCI
876	---help---
877	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
878	  systems. Needed to run systems with more than 3GB of memory
879	  properly with 32-bit PCI devices that do not support DAC
880	  (Double Address Cycle). Calgary also supports bus level
881	  isolation, where all DMAs pass through the IOMMU.  This
882	  prevents them from going anywhere except their intended
883	  destination. This catches hard-to-find kernel bugs and
884	  mis-behaving drivers and devices that do not use the DMA-API
885	  properly to set up their DMA buffers.  The IOMMU can be
886	  turned off at boot time with the iommu=off parameter.
887	  Normally the kernel will make the right choice by itself.
888	  If unsure, say Y.
889
890config CALGARY_IOMMU_ENABLED_BY_DEFAULT
891	def_bool y
892	prompt "Should Calgary be enabled by default?"
893	depends on CALGARY_IOMMU
894	---help---
895	  Should Calgary be enabled by default? if you choose 'y', Calgary
896	  will be used (if it exists). If you choose 'n', Calgary will not be
897	  used even if it exists. If you choose 'n' and would like to use
898	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
899	  If unsure, say Y.
900
901# need this always selected by IOMMU for the VIA workaround
902config SWIOTLB
903	def_bool y if X86_64
904	---help---
905	  Support for software bounce buffers used on x86-64 systems
906	  which don't have a hardware IOMMU. Using this PCI devices
907	  which can only access 32-bits of memory can be used on systems
908	  with more than 3 GB of memory.
909	  If unsure, say Y.
910
911config IOMMU_HELPER
912	def_bool y
913	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
914
915config MAXSMP
916	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
917	depends on X86_64 && SMP && DEBUG_KERNEL
918	select CPUMASK_OFFSTACK
919	---help---
920	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
921	  If unsure, say N.
922
923config NR_CPUS
924	int "Maximum number of CPUs" if SMP && !MAXSMP
925	range 2 8 if SMP && X86_32 && !X86_BIGSMP
926	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
927	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
928	default "1" if !SMP
929	default "8192" if MAXSMP
930	default "32" if SMP && X86_BIGSMP
931	default "8" if SMP && X86_32
932	default "64" if SMP
933	---help---
934	  This allows you to specify the maximum number of CPUs which this
935	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
936	  supported value is 8192, otherwise the maximum value is 512.  The
937	  minimum value which makes sense is 2.
938
939	  This is purely to save memory - each supported CPU adds
940	  approximately eight kilobytes to the kernel image.
941
942config SCHED_SMT
943	bool "SMT (Hyperthreading) scheduler support"
944	depends on SMP
945	---help---
946	  SMT scheduler support improves the CPU scheduler's decision making
947	  when dealing with Intel Pentium 4 chips with HyperThreading at a
948	  cost of slightly increased overhead in some places. If unsure say
949	  N here.
950
951config SCHED_MC
952	def_bool y
953	prompt "Multi-core scheduler support"
954	depends on SMP
955	---help---
956	  Multi-core scheduler support improves the CPU scheduler's decision
957	  making when dealing with multi-core CPU chips at a cost of slightly
958	  increased overhead in some places. If unsure say N here.
959
960config SCHED_MC_PRIO
961	bool "CPU core priorities scheduler support"
962	depends on SCHED_MC && CPU_SUP_INTEL
963	select X86_INTEL_PSTATE
964	select CPU_FREQ
965	default y
966	---help---
967	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
968	  core ordering determined at manufacturing time, which allows
969	  certain cores to reach higher turbo frequencies (when running
970	  single threaded workloads) than others.
971
972	  Enabling this kernel feature teaches the scheduler about
973	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
974	  scheduler's CPU selection logic accordingly, so that higher
975	  overall system performance can be achieved.
976
977	  This feature will have no effect on CPUs without this feature.
978
979	  If unsure say Y here.
980
981source "kernel/Kconfig.preempt"
982
983config UP_LATE_INIT
984       def_bool y
985       depends on !SMP && X86_LOCAL_APIC
986
987config X86_UP_APIC
988	bool "Local APIC support on uniprocessors" if !PCI_MSI
989	default PCI_MSI
990	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
991	---help---
992	  A local APIC (Advanced Programmable Interrupt Controller) is an
993	  integrated interrupt controller in the CPU. If you have a single-CPU
994	  system which has a processor with a local APIC, you can say Y here to
995	  enable and use it. If you say Y here even though your machine doesn't
996	  have a local APIC, then the kernel will still run with no slowdown at
997	  all. The local APIC supports CPU-generated self-interrupts (timer,
998	  performance counters), and the NMI watchdog which detects hard
999	  lockups.
1000
1001config X86_UP_IOAPIC
1002	bool "IO-APIC support on uniprocessors"
1003	depends on X86_UP_APIC
1004	---help---
1005	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1006	  SMP-capable replacement for PC-style interrupt controllers. Most
1007	  SMP systems and many recent uniprocessor systems have one.
1008
1009	  If you have a single-CPU system with an IO-APIC, you can say Y here
1010	  to use it. If you say Y here even though your machine doesn't have
1011	  an IO-APIC, then the kernel will still run with no slowdown at all.
1012
1013config X86_LOCAL_APIC
1014	def_bool y
1015	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1016	select IRQ_DOMAIN_HIERARCHY
1017	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1018
1019config X86_IO_APIC
1020	def_bool y
1021	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1022
1023config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1024	bool "Reroute for broken boot IRQs"
1025	depends on X86_IO_APIC
1026	---help---
1027	  This option enables a workaround that fixes a source of
1028	  spurious interrupts. This is recommended when threaded
1029	  interrupt handling is used on systems where the generation of
1030	  superfluous "boot interrupts" cannot be disabled.
1031
1032	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1033	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1034	  kernel does during interrupt handling). On chipsets where this
1035	  boot IRQ generation cannot be disabled, this workaround keeps
1036	  the original IRQ line masked so that only the equivalent "boot
1037	  IRQ" is delivered to the CPUs. The workaround also tells the
1038	  kernel to set up the IRQ handler on the boot IRQ line. In this
1039	  way only one interrupt is delivered to the kernel. Otherwise
1040	  the spurious second interrupt may cause the kernel to bring
1041	  down (vital) interrupt lines.
1042
1043	  Only affects "broken" chipsets. Interrupt sharing may be
1044	  increased on these systems.
1045
1046config X86_MCE
1047	bool "Machine Check / overheating reporting"
1048	select GENERIC_ALLOCATOR
1049	default y
1050	---help---
1051	  Machine Check support allows the processor to notify the
1052	  kernel if it detects a problem (e.g. overheating, data corruption).
1053	  The action the kernel takes depends on the severity of the problem,
1054	  ranging from warning messages to halting the machine.
1055
1056config X86_MCELOG_LEGACY
1057	bool "Support for deprecated /dev/mcelog character device"
1058	depends on X86_MCE
1059	---help---
1060	  Enable support for /dev/mcelog which is needed by the old mcelog
1061	  userspace logging daemon. Consider switching to the new generation
1062	  rasdaemon solution.
1063
1064config X86_MCE_INTEL
1065	def_bool y
1066	prompt "Intel MCE features"
1067	depends on X86_MCE && X86_LOCAL_APIC
1068	---help---
1069	   Additional support for intel specific MCE features such as
1070	   the thermal monitor.
1071
1072config X86_MCE_AMD
1073	def_bool y
1074	prompt "AMD MCE features"
1075	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1076	---help---
1077	   Additional support for AMD specific MCE features such as
1078	   the DRAM Error Threshold.
1079
1080config X86_ANCIENT_MCE
1081	bool "Support for old Pentium 5 / WinChip machine checks"
1082	depends on X86_32 && X86_MCE
1083	---help---
1084	  Include support for machine check handling on old Pentium 5 or WinChip
1085	  systems. These typically need to be enabled explicitly on the command
1086	  line.
1087
1088config X86_MCE_THRESHOLD
1089	depends on X86_MCE_AMD || X86_MCE_INTEL
1090	def_bool y
1091
1092config X86_MCE_INJECT
1093	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1094	tristate "Machine check injector support"
1095	---help---
1096	  Provide support for injecting machine checks for testing purposes.
1097	  If you don't know what a machine check is and you don't do kernel
1098	  QA it is safe to say n.
1099
1100config X86_THERMAL_VECTOR
1101	def_bool y
1102	depends on X86_MCE_INTEL
1103
1104source "arch/x86/events/Kconfig"
1105
1106config X86_LEGACY_VM86
1107	bool "Legacy VM86 support"
1108	default n
1109	depends on X86_32
1110	---help---
1111	  This option allows user programs to put the CPU into V8086
1112	  mode, which is an 80286-era approximation of 16-bit real mode.
1113
1114	  Some very old versions of X and/or vbetool require this option
1115	  for user mode setting.  Similarly, DOSEMU will use it if
1116	  available to accelerate real mode DOS programs.  However, any
1117	  recent version of DOSEMU, X, or vbetool should be fully
1118	  functional even without kernel VM86 support, as they will all
1119	  fall back to software emulation. Nevertheless, if you are using
1120	  a 16-bit DOS program where 16-bit performance matters, vm86
1121	  mode might be faster than emulation and you might want to
1122	  enable this option.
1123
1124	  Note that any app that works on a 64-bit kernel is unlikely to
1125	  need this option, as 64-bit kernels don't, and can't, support
1126	  V8086 mode. This option is also unrelated to 16-bit protected
1127	  mode and is not needed to run most 16-bit programs under Wine.
1128
1129	  Enabling this option increases the complexity of the kernel
1130	  and slows down exception handling a tiny bit.
1131
1132	  If unsure, say N here.
1133
1134config VM86
1135       bool
1136       default X86_LEGACY_VM86
1137
1138config X86_16BIT
1139	bool "Enable support for 16-bit segments" if EXPERT
1140	default y
1141	depends on MODIFY_LDT_SYSCALL
1142	---help---
1143	  This option is required by programs like Wine to run 16-bit
1144	  protected mode legacy code on x86 processors.  Disabling
1145	  this option saves about 300 bytes on i386, or around 6K text
1146	  plus 16K runtime memory on x86-64,
1147
1148config X86_ESPFIX32
1149	def_bool y
1150	depends on X86_16BIT && X86_32
1151
1152config X86_ESPFIX64
1153	def_bool y
1154	depends on X86_16BIT && X86_64
1155
1156config X86_VSYSCALL_EMULATION
1157       bool "Enable vsyscall emulation" if EXPERT
1158       default y
1159       depends on X86_64
1160       ---help---
1161	 This enables emulation of the legacy vsyscall page.  Disabling
1162	 it is roughly equivalent to booting with vsyscall=none, except
1163	 that it will also disable the helpful warning if a program
1164	 tries to use a vsyscall.  With this option set to N, offending
1165	 programs will just segfault, citing addresses of the form
1166	 0xffffffffff600?00.
1167
1168	 This option is required by many programs built before 2013, and
1169	 care should be used even with newer programs if set to N.
1170
1171	 Disabling this option saves about 7K of kernel size and
1172	 possibly 4K of additional runtime pagetable memory.
1173
1174config TOSHIBA
1175	tristate "Toshiba Laptop support"
1176	depends on X86_32
1177	---help---
1178	  This adds a driver to safely access the System Management Mode of
1179	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1180	  not work on models with a Phoenix BIOS. The System Management Mode
1181	  is used to set the BIOS and power saving options on Toshiba portables.
1182
1183	  For information on utilities to make use of this driver see the
1184	  Toshiba Linux utilities web site at:
1185	  <http://www.buzzard.org.uk/toshiba/>.
1186
1187	  Say Y if you intend to run this kernel on a Toshiba portable.
1188	  Say N otherwise.
1189
1190config I8K
1191	tristate "Dell i8k legacy laptop support"
1192	select HWMON
1193	select SENSORS_DELL_SMM
1194	---help---
1195	  This option enables legacy /proc/i8k userspace interface in hwmon
1196	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1197	  temperature and allows controlling fan speeds of Dell laptops via
1198	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1199	  it reports also power and hotkey status. For fan speed control is
1200	  needed userspace package i8kutils.
1201
1202	  Say Y if you intend to run this kernel on old Dell laptops or want to
1203	  use userspace package i8kutils.
1204	  Say N otherwise.
1205
1206config X86_REBOOTFIXUPS
1207	bool "Enable X86 board specific fixups for reboot"
1208	depends on X86_32
1209	---help---
1210	  This enables chipset and/or board specific fixups to be done
1211	  in order to get reboot to work correctly. This is only needed on
1212	  some combinations of hardware and BIOS. The symptom, for which
1213	  this config is intended, is when reboot ends with a stalled/hung
1214	  system.
1215
1216	  Currently, the only fixup is for the Geode machines using
1217	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1218
1219	  Say Y if you want to enable the fixup. Currently, it's safe to
1220	  enable this option even if you don't need it.
1221	  Say N otherwise.
1222
1223config MICROCODE
1224	bool "CPU microcode loading support"
1225	default y
1226	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1227	select FW_LOADER
1228	---help---
1229	  If you say Y here, you will be able to update the microcode on
1230	  Intel and AMD processors. The Intel support is for the IA32 family,
1231	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1232	  AMD support is for families 0x10 and later. You will obviously need
1233	  the actual microcode binary data itself which is not shipped with
1234	  the Linux kernel.
1235
1236	  The preferred method to load microcode from a detached initrd is described
1237	  in Documentation/x86/early-microcode.txt. For that you need to enable
1238	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1239	  initrd for microcode blobs.
1240
1241	  In addition, you can build-in the microcode into the kernel. For that you
1242	  need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1243	  to the CONFIG_EXTRA_FIRMWARE config option.
1244
1245config MICROCODE_INTEL
1246	bool "Intel microcode loading support"
1247	depends on MICROCODE
1248	default MICROCODE
1249	select FW_LOADER
1250	---help---
1251	  This options enables microcode patch loading support for Intel
1252	  processors.
1253
1254	  For the current Intel microcode data package go to
1255	  <https://downloadcenter.intel.com> and search for
1256	  'Linux Processor Microcode Data File'.
1257
1258config MICROCODE_AMD
1259	bool "AMD microcode loading support"
1260	depends on MICROCODE
1261	select FW_LOADER
1262	---help---
1263	  If you select this option, microcode patch loading support for AMD
1264	  processors will be enabled.
1265
1266config MICROCODE_OLD_INTERFACE
1267	def_bool y
1268	depends on MICROCODE
1269
1270config X86_MSR
1271	tristate "/dev/cpu/*/msr - Model-specific register support"
1272	---help---
1273	  This device gives privileged processes access to the x86
1274	  Model-Specific Registers (MSRs).  It is a character device with
1275	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1276	  MSR accesses are directed to a specific CPU on multi-processor
1277	  systems.
1278
1279config X86_CPUID
1280	tristate "/dev/cpu/*/cpuid - CPU information support"
1281	---help---
1282	  This device gives processes access to the x86 CPUID instruction to
1283	  be executed on a specific processor.  It is a character device
1284	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1285	  /dev/cpu/31/cpuid.
1286
1287choice
1288	prompt "High Memory Support"
1289	default HIGHMEM4G
1290	depends on X86_32
1291
1292config NOHIGHMEM
1293	bool "off"
1294	---help---
1295	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1296	  However, the address space of 32-bit x86 processors is only 4
1297	  Gigabytes large. That means that, if you have a large amount of
1298	  physical memory, not all of it can be "permanently mapped" by the
1299	  kernel. The physical memory that's not permanently mapped is called
1300	  "high memory".
1301
1302	  If you are compiling a kernel which will never run on a machine with
1303	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1304	  choice and suitable for most users). This will result in a "3GB/1GB"
1305	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1306	  space and the remaining part of the 4GB virtual memory space is used
1307	  by the kernel to permanently map as much physical memory as
1308	  possible.
1309
1310	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1311	  answer "4GB" here.
1312
1313	  If more than 4 Gigabytes is used then answer "64GB" here. This
1314	  selection turns Intel PAE (Physical Address Extension) mode on.
1315	  PAE implements 3-level paging on IA32 processors. PAE is fully
1316	  supported by Linux, PAE mode is implemented on all recent Intel
1317	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1318	  then the kernel will not boot on CPUs that don't support PAE!
1319
1320	  The actual amount of total physical memory will either be
1321	  auto detected or can be forced by using a kernel command line option
1322	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1323	  your boot loader (lilo or loadlin) about how to pass options to the
1324	  kernel at boot time.)
1325
1326	  If unsure, say "off".
1327
1328config HIGHMEM4G
1329	bool "4GB"
1330	---help---
1331	  Select this if you have a 32-bit processor and between 1 and 4
1332	  gigabytes of physical RAM.
1333
1334config HIGHMEM64G
1335	bool "64GB"
1336	depends on !M486
1337	select X86_PAE
1338	---help---
1339	  Select this if you have a 32-bit processor and more than 4
1340	  gigabytes of physical RAM.
1341
1342endchoice
1343
1344choice
1345	prompt "Memory split" if EXPERT
1346	default VMSPLIT_3G
1347	depends on X86_32
1348	---help---
1349	  Select the desired split between kernel and user memory.
1350
1351	  If the address range available to the kernel is less than the
1352	  physical memory installed, the remaining memory will be available
1353	  as "high memory". Accessing high memory is a little more costly
1354	  than low memory, as it needs to be mapped into the kernel first.
1355	  Note that increasing the kernel address space limits the range
1356	  available to user programs, making the address space there
1357	  tighter.  Selecting anything other than the default 3G/1G split
1358	  will also likely make your kernel incompatible with binary-only
1359	  kernel modules.
1360
1361	  If you are not absolutely sure what you are doing, leave this
1362	  option alone!
1363
1364	config VMSPLIT_3G
1365		bool "3G/1G user/kernel split"
1366	config VMSPLIT_3G_OPT
1367		depends on !X86_PAE
1368		bool "3G/1G user/kernel split (for full 1G low memory)"
1369	config VMSPLIT_2G
1370		bool "2G/2G user/kernel split"
1371	config VMSPLIT_2G_OPT
1372		depends on !X86_PAE
1373		bool "2G/2G user/kernel split (for full 2G low memory)"
1374	config VMSPLIT_1G
1375		bool "1G/3G user/kernel split"
1376endchoice
1377
1378config PAGE_OFFSET
1379	hex
1380	default 0xB0000000 if VMSPLIT_3G_OPT
1381	default 0x80000000 if VMSPLIT_2G
1382	default 0x78000000 if VMSPLIT_2G_OPT
1383	default 0x40000000 if VMSPLIT_1G
1384	default 0xC0000000
1385	depends on X86_32
1386
1387config HIGHMEM
1388	def_bool y
1389	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1390
1391config X86_PAE
1392	bool "PAE (Physical Address Extension) Support"
1393	depends on X86_32 && !HIGHMEM4G
1394	select SWIOTLB
1395	---help---
1396	  PAE is required for NX support, and furthermore enables
1397	  larger swapspace support for non-overcommit purposes. It
1398	  has the cost of more pagetable lookup overhead, and also
1399	  consumes more pagetable space per process.
1400
1401config ARCH_PHYS_ADDR_T_64BIT
1402	def_bool y
1403	depends on X86_64 || X86_PAE
1404
1405config ARCH_DMA_ADDR_T_64BIT
1406	def_bool y
1407	depends on X86_64 || HIGHMEM64G
1408
1409config X86_DIRECT_GBPAGES
1410	def_bool y
1411	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1412	---help---
1413	  Certain kernel features effectively disable kernel
1414	  linear 1 GB mappings (even if the CPU otherwise
1415	  supports them), so don't confuse the user by printing
1416	  that we have them enabled.
1417
1418config ARCH_HAS_MEM_ENCRYPT
1419	def_bool y
1420
1421config AMD_MEM_ENCRYPT
1422	bool "AMD Secure Memory Encryption (SME) support"
1423	depends on X86_64 && CPU_SUP_AMD
1424	---help---
1425	  Say yes to enable support for the encryption of system memory.
1426	  This requires an AMD processor that supports Secure Memory
1427	  Encryption (SME).
1428
1429config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1430	bool "Activate AMD Secure Memory Encryption (SME) by default"
1431	default y
1432	depends on AMD_MEM_ENCRYPT
1433	---help---
1434	  Say yes to have system memory encrypted by default if running on
1435	  an AMD processor that supports Secure Memory Encryption (SME).
1436
1437	  If set to Y, then the encryption of system memory can be
1438	  deactivated with the mem_encrypt=off command line option.
1439
1440	  If set to N, then the encryption of system memory can be
1441	  activated with the mem_encrypt=on command line option.
1442
1443# Common NUMA Features
1444config NUMA
1445	bool "Numa Memory Allocation and Scheduler Support"
1446	depends on SMP
1447	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1448	default y if X86_BIGSMP
1449	---help---
1450	  Enable NUMA (Non Uniform Memory Access) support.
1451
1452	  The kernel will try to allocate memory used by a CPU on the
1453	  local memory controller of the CPU and add some more
1454	  NUMA awareness to the kernel.
1455
1456	  For 64-bit this is recommended if the system is Intel Core i7
1457	  (or later), AMD Opteron, or EM64T NUMA.
1458
1459	  For 32-bit this is only needed if you boot a 32-bit
1460	  kernel on a 64-bit NUMA platform.
1461
1462	  Otherwise, you should say N.
1463
1464config AMD_NUMA
1465	def_bool y
1466	prompt "Old style AMD Opteron NUMA detection"
1467	depends on X86_64 && NUMA && PCI
1468	---help---
1469	  Enable AMD NUMA node topology detection.  You should say Y here if
1470	  you have a multi processor AMD system. This uses an old method to
1471	  read the NUMA configuration directly from the builtin Northbridge
1472	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1473	  which also takes priority if both are compiled in.
1474
1475config X86_64_ACPI_NUMA
1476	def_bool y
1477	prompt "ACPI NUMA detection"
1478	depends on X86_64 && NUMA && ACPI && PCI
1479	select ACPI_NUMA
1480	---help---
1481	  Enable ACPI SRAT based node topology detection.
1482
1483# Some NUMA nodes have memory ranges that span
1484# other nodes.  Even though a pfn is valid and
1485# between a node's start and end pfns, it may not
1486# reside on that node.  See memmap_init_zone()
1487# for details.
1488config NODES_SPAN_OTHER_NODES
1489	def_bool y
1490	depends on X86_64_ACPI_NUMA
1491
1492config NUMA_EMU
1493	bool "NUMA emulation"
1494	depends on NUMA
1495	---help---
1496	  Enable NUMA emulation. A flat machine will be split
1497	  into virtual nodes when booted with "numa=fake=N", where N is the
1498	  number of nodes. This is only useful for debugging.
1499
1500config NODES_SHIFT
1501	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1502	range 1 10
1503	default "10" if MAXSMP
1504	default "6" if X86_64
1505	default "3"
1506	depends on NEED_MULTIPLE_NODES
1507	---help---
1508	  Specify the maximum number of NUMA Nodes available on the target
1509	  system.  Increases memory reserved to accommodate various tables.
1510
1511config ARCH_HAVE_MEMORY_PRESENT
1512	def_bool y
1513	depends on X86_32 && DISCONTIGMEM
1514
1515config NEED_NODE_MEMMAP_SIZE
1516	def_bool y
1517	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1518
1519config ARCH_FLATMEM_ENABLE
1520	def_bool y
1521	depends on X86_32 && !NUMA
1522
1523config ARCH_DISCONTIGMEM_ENABLE
1524	def_bool y
1525	depends on NUMA && X86_32
1526
1527config ARCH_DISCONTIGMEM_DEFAULT
1528	def_bool y
1529	depends on NUMA && X86_32
1530
1531config ARCH_SPARSEMEM_ENABLE
1532	def_bool y
1533	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1534	select SPARSEMEM_STATIC if X86_32
1535	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1536
1537config ARCH_SPARSEMEM_DEFAULT
1538	def_bool y
1539	depends on X86_64
1540
1541config ARCH_SELECT_MEMORY_MODEL
1542	def_bool y
1543	depends on ARCH_SPARSEMEM_ENABLE
1544
1545config ARCH_MEMORY_PROBE
1546	bool "Enable sysfs memory/probe interface"
1547	depends on X86_64 && MEMORY_HOTPLUG
1548	help
1549	  This option enables a sysfs memory/probe interface for testing.
1550	  See Documentation/memory-hotplug.txt for more information.
1551	  If you are unsure how to answer this question, answer N.
1552
1553config ARCH_PROC_KCORE_TEXT
1554	def_bool y
1555	depends on X86_64 && PROC_KCORE
1556
1557config ILLEGAL_POINTER_VALUE
1558       hex
1559       default 0 if X86_32
1560       default 0xdead000000000000 if X86_64
1561
1562source "mm/Kconfig"
1563
1564config X86_PMEM_LEGACY_DEVICE
1565	bool
1566
1567config X86_PMEM_LEGACY
1568	tristate "Support non-standard NVDIMMs and ADR protected memory"
1569	depends on PHYS_ADDR_T_64BIT
1570	depends on BLK_DEV
1571	select X86_PMEM_LEGACY_DEVICE
1572	select LIBNVDIMM
1573	help
1574	  Treat memory marked using the non-standard e820 type of 12 as used
1575	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1576	  The kernel will offer these regions to the 'pmem' driver so
1577	  they can be used for persistent storage.
1578
1579	  Say Y if unsure.
1580
1581config HIGHPTE
1582	bool "Allocate 3rd-level pagetables from highmem"
1583	depends on HIGHMEM
1584	---help---
1585	  The VM uses one page table entry for each page of physical memory.
1586	  For systems with a lot of RAM, this can be wasteful of precious
1587	  low memory.  Setting this option will put user-space page table
1588	  entries in high memory.
1589
1590config X86_CHECK_BIOS_CORRUPTION
1591	bool "Check for low memory corruption"
1592	---help---
1593	  Periodically check for memory corruption in low memory, which
1594	  is suspected to be caused by BIOS.  Even when enabled in the
1595	  configuration, it is disabled at runtime.  Enable it by
1596	  setting "memory_corruption_check=1" on the kernel command
1597	  line.  By default it scans the low 64k of memory every 60
1598	  seconds; see the memory_corruption_check_size and
1599	  memory_corruption_check_period parameters in
1600	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1601
1602	  When enabled with the default parameters, this option has
1603	  almost no overhead, as it reserves a relatively small amount
1604	  of memory and scans it infrequently.  It both detects corruption
1605	  and prevents it from affecting the running system.
1606
1607	  It is, however, intended as a diagnostic tool; if repeatable
1608	  BIOS-originated corruption always affects the same memory,
1609	  you can use memmap= to prevent the kernel from using that
1610	  memory.
1611
1612config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1613	bool "Set the default setting of memory_corruption_check"
1614	depends on X86_CHECK_BIOS_CORRUPTION
1615	default y
1616	---help---
1617	  Set whether the default state of memory_corruption_check is
1618	  on or off.
1619
1620config X86_RESERVE_LOW
1621	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1622	default 64
1623	range 4 640
1624	---help---
1625	  Specify the amount of low memory to reserve for the BIOS.
1626
1627	  The first page contains BIOS data structures that the kernel
1628	  must not use, so that page must always be reserved.
1629
1630	  By default we reserve the first 64K of physical RAM, as a
1631	  number of BIOSes are known to corrupt that memory range
1632	  during events such as suspend/resume or monitor cable
1633	  insertion, so it must not be used by the kernel.
1634
1635	  You can set this to 4 if you are absolutely sure that you
1636	  trust the BIOS to get all its memory reservations and usages
1637	  right.  If you know your BIOS have problems beyond the
1638	  default 64K area, you can set this to 640 to avoid using the
1639	  entire low memory range.
1640
1641	  If you have doubts about the BIOS (e.g. suspend/resume does
1642	  not work or there's kernel crashes after certain hardware
1643	  hotplug events) then you might want to enable
1644	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1645	  typical corruption patterns.
1646
1647	  Leave this to the default value of 64 if you are unsure.
1648
1649config MATH_EMULATION
1650	bool
1651	depends on MODIFY_LDT_SYSCALL
1652	prompt "Math emulation" if X86_32
1653	---help---
1654	  Linux can emulate a math coprocessor (used for floating point
1655	  operations) if you don't have one. 486DX and Pentium processors have
1656	  a math coprocessor built in, 486SX and 386 do not, unless you added
1657	  a 487DX or 387, respectively. (The messages during boot time can
1658	  give you some hints here ["man dmesg"].) Everyone needs either a
1659	  coprocessor or this emulation.
1660
1661	  If you don't have a math coprocessor, you need to say Y here; if you
1662	  say Y here even though you have a coprocessor, the coprocessor will
1663	  be used nevertheless. (This behavior can be changed with the kernel
1664	  command line option "no387", which comes handy if your coprocessor
1665	  is broken. Try "man bootparam" or see the documentation of your boot
1666	  loader (lilo or loadlin) about how to pass options to the kernel at
1667	  boot time.) This means that it is a good idea to say Y here if you
1668	  intend to use this kernel on different machines.
1669
1670	  More information about the internals of the Linux math coprocessor
1671	  emulation can be found in <file:arch/x86/math-emu/README>.
1672
1673	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1674	  kernel, it won't hurt.
1675
1676config MTRR
1677	def_bool y
1678	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1679	---help---
1680	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1681	  the Memory Type Range Registers (MTRRs) may be used to control
1682	  processor access to memory ranges. This is most useful if you have
1683	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1684	  allows bus write transfers to be combined into a larger transfer
1685	  before bursting over the PCI/AGP bus. This can increase performance
1686	  of image write operations 2.5 times or more. Saying Y here creates a
1687	  /proc/mtrr file which may be used to manipulate your processor's
1688	  MTRRs. Typically the X server should use this.
1689
1690	  This code has a reasonably generic interface so that similar
1691	  control registers on other processors can be easily supported
1692	  as well:
1693
1694	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1695	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1696	  these, the ARRs are used to emulate the MTRRs.
1697	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1698	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1699	  write-combining. All of these processors are supported by this code
1700	  and it makes sense to say Y here if you have one of them.
1701
1702	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1703	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1704	  can lead to all sorts of problems, so it's good to say Y here.
1705
1706	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1707	  just add about 9 KB to your kernel.
1708
1709	  See <file:Documentation/x86/mtrr.txt> for more information.
1710
1711config MTRR_SANITIZER
1712	def_bool y
1713	prompt "MTRR cleanup support"
1714	depends on MTRR
1715	---help---
1716	  Convert MTRR layout from continuous to discrete, so X drivers can
1717	  add writeback entries.
1718
1719	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1720	  The largest mtrr entry size for a continuous block can be set with
1721	  mtrr_chunk_size.
1722
1723	  If unsure, say Y.
1724
1725config MTRR_SANITIZER_ENABLE_DEFAULT
1726	int "MTRR cleanup enable value (0-1)"
1727	range 0 1
1728	default "0"
1729	depends on MTRR_SANITIZER
1730	---help---
1731	  Enable mtrr cleanup default value
1732
1733config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1734	int "MTRR cleanup spare reg num (0-7)"
1735	range 0 7
1736	default "1"
1737	depends on MTRR_SANITIZER
1738	---help---
1739	  mtrr cleanup spare entries default, it can be changed via
1740	  mtrr_spare_reg_nr=N on the kernel command line.
1741
1742config X86_PAT
1743	def_bool y
1744	prompt "x86 PAT support" if EXPERT
1745	depends on MTRR
1746	---help---
1747	  Use PAT attributes to setup page level cache control.
1748
1749	  PATs are the modern equivalents of MTRRs and are much more
1750	  flexible than MTRRs.
1751
1752	  Say N here if you see bootup problems (boot crash, boot hang,
1753	  spontaneous reboots) or a non-working video driver.
1754
1755	  If unsure, say Y.
1756
1757config ARCH_USES_PG_UNCACHED
1758	def_bool y
1759	depends on X86_PAT
1760
1761config ARCH_RANDOM
1762	def_bool y
1763	prompt "x86 architectural random number generator" if EXPERT
1764	---help---
1765	  Enable the x86 architectural RDRAND instruction
1766	  (Intel Bull Mountain technology) to generate random numbers.
1767	  If supported, this is a high bandwidth, cryptographically
1768	  secure hardware random number generator.
1769
1770config X86_SMAP
1771	def_bool y
1772	prompt "Supervisor Mode Access Prevention" if EXPERT
1773	---help---
1774	  Supervisor Mode Access Prevention (SMAP) is a security
1775	  feature in newer Intel processors.  There is a small
1776	  performance cost if this enabled and turned on; there is
1777	  also a small increase in the kernel size if this is enabled.
1778
1779	  If unsure, say Y.
1780
1781config X86_INTEL_MPX
1782	prompt "Intel MPX (Memory Protection Extensions)"
1783	def_bool n
1784	depends on CPU_SUP_INTEL
1785	---help---
1786	  MPX provides hardware features that can be used in
1787	  conjunction with compiler-instrumented code to check
1788	  memory references.  It is designed to detect buffer
1789	  overflow or underflow bugs.
1790
1791	  This option enables running applications which are
1792	  instrumented or otherwise use MPX.  It does not use MPX
1793	  itself inside the kernel or to protect the kernel
1794	  against bad memory references.
1795
1796	  Enabling this option will make the kernel larger:
1797	  ~8k of kernel text and 36 bytes of data on a 64-bit
1798	  defconfig.  It adds a long to the 'mm_struct' which
1799	  will increase the kernel memory overhead of each
1800	  process and adds some branches to paths used during
1801	  exec() and munmap().
1802
1803	  For details, see Documentation/x86/intel_mpx.txt
1804
1805	  If unsure, say N.
1806
1807config X86_INTEL_MEMORY_PROTECTION_KEYS
1808	prompt "Intel Memory Protection Keys"
1809	def_bool y
1810	# Note: only available in 64-bit mode
1811	depends on CPU_SUP_INTEL && X86_64
1812	select ARCH_USES_HIGH_VMA_FLAGS
1813	select ARCH_HAS_PKEYS
1814	---help---
1815	  Memory Protection Keys provides a mechanism for enforcing
1816	  page-based protections, but without requiring modification of the
1817	  page tables when an application changes protection domains.
1818
1819	  For details, see Documentation/x86/protection-keys.txt
1820
1821	  If unsure, say y.
1822
1823config EFI
1824	bool "EFI runtime service support"
1825	depends on ACPI
1826	select UCS2_STRING
1827	select EFI_RUNTIME_WRAPPERS
1828	---help---
1829	  This enables the kernel to use EFI runtime services that are
1830	  available (such as the EFI variable services).
1831
1832	  This option is only useful on systems that have EFI firmware.
1833	  In addition, you should use the latest ELILO loader available
1834	  at <http://elilo.sourceforge.net> in order to take advantage
1835	  of EFI runtime services. However, even with this option, the
1836	  resultant kernel should continue to boot on existing non-EFI
1837	  platforms.
1838
1839config EFI_STUB
1840       bool "EFI stub support"
1841       depends on EFI && !X86_USE_3DNOW
1842       select RELOCATABLE
1843       ---help---
1844          This kernel feature allows a bzImage to be loaded directly
1845	  by EFI firmware without the use of a bootloader.
1846
1847	  See Documentation/efi-stub.txt for more information.
1848
1849config EFI_MIXED
1850	bool "EFI mixed-mode support"
1851	depends on EFI_STUB && X86_64
1852	---help---
1853	   Enabling this feature allows a 64-bit kernel to be booted
1854	   on a 32-bit firmware, provided that your CPU supports 64-bit
1855	   mode.
1856
1857	   Note that it is not possible to boot a mixed-mode enabled
1858	   kernel via the EFI boot stub - a bootloader that supports
1859	   the EFI handover protocol must be used.
1860
1861	   If unsure, say N.
1862
1863config SECCOMP
1864	def_bool y
1865	prompt "Enable seccomp to safely compute untrusted bytecode"
1866	---help---
1867	  This kernel feature is useful for number crunching applications
1868	  that may need to compute untrusted bytecode during their
1869	  execution. By using pipes or other transports made available to
1870	  the process as file descriptors supporting the read/write
1871	  syscalls, it's possible to isolate those applications in
1872	  their own address space using seccomp. Once seccomp is
1873	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1874	  and the task is only allowed to execute a few safe syscalls
1875	  defined by each seccomp mode.
1876
1877	  If unsure, say Y. Only embedded should say N here.
1878
1879source kernel/Kconfig.hz
1880
1881config KEXEC
1882	bool "kexec system call"
1883	select KEXEC_CORE
1884	---help---
1885	  kexec is a system call that implements the ability to shutdown your
1886	  current kernel, and to start another kernel.  It is like a reboot
1887	  but it is independent of the system firmware.   And like a reboot
1888	  you can start any kernel with it, not just Linux.
1889
1890	  The name comes from the similarity to the exec system call.
1891
1892	  It is an ongoing process to be certain the hardware in a machine
1893	  is properly shutdown, so do not be surprised if this code does not
1894	  initially work for you.  As of this writing the exact hardware
1895	  interface is strongly in flux, so no good recommendation can be
1896	  made.
1897
1898config KEXEC_FILE
1899	bool "kexec file based system call"
1900	select KEXEC_CORE
1901	select BUILD_BIN2C
1902	depends on X86_64
1903	depends on CRYPTO=y
1904	depends on CRYPTO_SHA256=y
1905	---help---
1906	  This is new version of kexec system call. This system call is
1907	  file based and takes file descriptors as system call argument
1908	  for kernel and initramfs as opposed to list of segments as
1909	  accepted by previous system call.
1910
1911config KEXEC_VERIFY_SIG
1912	bool "Verify kernel signature during kexec_file_load() syscall"
1913	depends on KEXEC_FILE
1914	---help---
1915	  This option makes kernel signature verification mandatory for
1916	  the kexec_file_load() syscall.
1917
1918	  In addition to that option, you need to enable signature
1919	  verification for the corresponding kernel image type being
1920	  loaded in order for this to work.
1921
1922config KEXEC_BZIMAGE_VERIFY_SIG
1923	bool "Enable bzImage signature verification support"
1924	depends on KEXEC_VERIFY_SIG
1925	depends on SIGNED_PE_FILE_VERIFICATION
1926	select SYSTEM_TRUSTED_KEYRING
1927	---help---
1928	  Enable bzImage signature verification support.
1929
1930config CRASH_DUMP
1931	bool "kernel crash dumps"
1932	depends on X86_64 || (X86_32 && HIGHMEM)
1933	---help---
1934	  Generate crash dump after being started by kexec.
1935	  This should be normally only set in special crash dump kernels
1936	  which are loaded in the main kernel with kexec-tools into
1937	  a specially reserved region and then later executed after
1938	  a crash by kdump/kexec. The crash dump kernel must be compiled
1939	  to a memory address not used by the main kernel or BIOS using
1940	  PHYSICAL_START, or it must be built as a relocatable image
1941	  (CONFIG_RELOCATABLE=y).
1942	  For more details see Documentation/kdump/kdump.txt
1943
1944config KEXEC_JUMP
1945	bool "kexec jump"
1946	depends on KEXEC && HIBERNATION
1947	---help---
1948	  Jump between original kernel and kexeced kernel and invoke
1949	  code in physical address mode via KEXEC
1950
1951config PHYSICAL_START
1952	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1953	default "0x1000000"
1954	---help---
1955	  This gives the physical address where the kernel is loaded.
1956
1957	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1958	  bzImage will decompress itself to above physical address and
1959	  run from there. Otherwise, bzImage will run from the address where
1960	  it has been loaded by the boot loader and will ignore above physical
1961	  address.
1962
1963	  In normal kdump cases one does not have to set/change this option
1964	  as now bzImage can be compiled as a completely relocatable image
1965	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1966	  address. This option is mainly useful for the folks who don't want
1967	  to use a bzImage for capturing the crash dump and want to use a
1968	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
1969	  to be specifically compiled to run from a specific memory area
1970	  (normally a reserved region) and this option comes handy.
1971
1972	  So if you are using bzImage for capturing the crash dump,
1973	  leave the value here unchanged to 0x1000000 and set
1974	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1975	  for capturing the crash dump change this value to start of
1976	  the reserved region.  In other words, it can be set based on
1977	  the "X" value as specified in the "crashkernel=YM@XM"
1978	  command line boot parameter passed to the panic-ed
1979	  kernel. Please take a look at Documentation/kdump/kdump.txt
1980	  for more details about crash dumps.
1981
1982	  Usage of bzImage for capturing the crash dump is recommended as
1983	  one does not have to build two kernels. Same kernel can be used
1984	  as production kernel and capture kernel. Above option should have
1985	  gone away after relocatable bzImage support is introduced. But it
1986	  is present because there are users out there who continue to use
1987	  vmlinux for dump capture. This option should go away down the
1988	  line.
1989
1990	  Don't change this unless you know what you are doing.
1991
1992config RELOCATABLE
1993	bool "Build a relocatable kernel"
1994	default y
1995	---help---
1996	  This builds a kernel image that retains relocation information
1997	  so it can be loaded someplace besides the default 1MB.
1998	  The relocations tend to make the kernel binary about 10% larger,
1999	  but are discarded at runtime.
2000
2001	  One use is for the kexec on panic case where the recovery kernel
2002	  must live at a different physical address than the primary
2003	  kernel.
2004
2005	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2006	  it has been loaded at and the compile time physical address
2007	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2008
2009config RANDOMIZE_BASE
2010	bool "Randomize the address of the kernel image (KASLR)"
2011	depends on RELOCATABLE
2012	default y
2013	---help---
2014	  In support of Kernel Address Space Layout Randomization (KASLR),
2015	  this randomizes the physical address at which the kernel image
2016	  is decompressed and the virtual address where the kernel
2017	  image is mapped, as a security feature that deters exploit
2018	  attempts relying on knowledge of the location of kernel
2019	  code internals.
2020
2021	  On 64-bit, the kernel physical and virtual addresses are
2022	  randomized separately. The physical address will be anywhere
2023	  between 16MB and the top of physical memory (up to 64TB). The
2024	  virtual address will be randomized from 16MB up to 1GB (9 bits
2025	  of entropy). Note that this also reduces the memory space
2026	  available to kernel modules from 1.5GB to 1GB.
2027
2028	  On 32-bit, the kernel physical and virtual addresses are
2029	  randomized together. They will be randomized from 16MB up to
2030	  512MB (8 bits of entropy).
2031
2032	  Entropy is generated using the RDRAND instruction if it is
2033	  supported. If RDTSC is supported, its value is mixed into
2034	  the entropy pool as well. If neither RDRAND nor RDTSC are
2035	  supported, then entropy is read from the i8254 timer. The
2036	  usable entropy is limited by the kernel being built using
2037	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2038	  minimum of 2MB. As a result, only 10 bits of entropy are
2039	  theoretically possible, but the implementations are further
2040	  limited due to memory layouts.
2041
2042	  If unsure, say Y.
2043
2044# Relocation on x86 needs some additional build support
2045config X86_NEED_RELOCS
2046	def_bool y
2047	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2048
2049config PHYSICAL_ALIGN
2050	hex "Alignment value to which kernel should be aligned"
2051	default "0x200000"
2052	range 0x2000 0x1000000 if X86_32
2053	range 0x200000 0x1000000 if X86_64
2054	---help---
2055	  This value puts the alignment restrictions on physical address
2056	  where kernel is loaded and run from. Kernel is compiled for an
2057	  address which meets above alignment restriction.
2058
2059	  If bootloader loads the kernel at a non-aligned address and
2060	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2061	  address aligned to above value and run from there.
2062
2063	  If bootloader loads the kernel at a non-aligned address and
2064	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2065	  load address and decompress itself to the address it has been
2066	  compiled for and run from there. The address for which kernel is
2067	  compiled already meets above alignment restrictions. Hence the
2068	  end result is that kernel runs from a physical address meeting
2069	  above alignment restrictions.
2070
2071	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2072	  this value must be a multiple of 0x200000.
2073
2074	  Don't change this unless you know what you are doing.
2075
2076config RANDOMIZE_MEMORY
2077	bool "Randomize the kernel memory sections"
2078	depends on X86_64
2079	depends on RANDOMIZE_BASE
2080	default RANDOMIZE_BASE
2081	---help---
2082	   Randomizes the base virtual address of kernel memory sections
2083	   (physical memory mapping, vmalloc & vmemmap). This security feature
2084	   makes exploits relying on predictable memory locations less reliable.
2085
2086	   The order of allocations remains unchanged. Entropy is generated in
2087	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2088	   configuration have in average 30,000 different possible virtual
2089	   addresses for each memory section.
2090
2091	   If unsure, say Y.
2092
2093config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2094	hex "Physical memory mapping padding" if EXPERT
2095	depends on RANDOMIZE_MEMORY
2096	default "0xa" if MEMORY_HOTPLUG
2097	default "0x0"
2098	range 0x1 0x40 if MEMORY_HOTPLUG
2099	range 0x0 0x40
2100	---help---
2101	   Define the padding in terabytes added to the existing physical
2102	   memory size during kernel memory randomization. It is useful
2103	   for memory hotplug support but reduces the entropy available for
2104	   address randomization.
2105
2106	   If unsure, leave at the default value.
2107
2108config HOTPLUG_CPU
2109	bool "Support for hot-pluggable CPUs"
2110	depends on SMP
2111	---help---
2112	  Say Y here to allow turning CPUs off and on. CPUs can be
2113	  controlled through /sys/devices/system/cpu.
2114	  ( Note: power management support will enable this option
2115	    automatically on SMP systems. )
2116	  Say N if you want to disable CPU hotplug.
2117
2118config BOOTPARAM_HOTPLUG_CPU0
2119	bool "Set default setting of cpu0_hotpluggable"
2120	default n
2121	depends on HOTPLUG_CPU
2122	---help---
2123	  Set whether default state of cpu0_hotpluggable is on or off.
2124
2125	  Say Y here to enable CPU0 hotplug by default. If this switch
2126	  is turned on, there is no need to give cpu0_hotplug kernel
2127	  parameter and the CPU0 hotplug feature is enabled by default.
2128
2129	  Please note: there are two known CPU0 dependencies if you want
2130	  to enable the CPU0 hotplug feature either by this switch or by
2131	  cpu0_hotplug kernel parameter.
2132
2133	  First, resume from hibernate or suspend always starts from CPU0.
2134	  So hibernate and suspend are prevented if CPU0 is offline.
2135
2136	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2137	  offline if any interrupt can not migrate out of CPU0. There may
2138	  be other CPU0 dependencies.
2139
2140	  Please make sure the dependencies are under your control before
2141	  you enable this feature.
2142
2143	  Say N if you don't want to enable CPU0 hotplug feature by default.
2144	  You still can enable the CPU0 hotplug feature at boot by kernel
2145	  parameter cpu0_hotplug.
2146
2147config DEBUG_HOTPLUG_CPU0
2148	def_bool n
2149	prompt "Debug CPU0 hotplug"
2150	depends on HOTPLUG_CPU
2151	---help---
2152	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2153	  soon as possible and boots up userspace with CPU0 offlined. User
2154	  can online CPU0 back after boot time.
2155
2156	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2157	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2158	  compilation or giving cpu0_hotplug kernel parameter at boot.
2159
2160	  If unsure, say N.
2161
2162config COMPAT_VDSO
2163	def_bool n
2164	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2165	depends on COMPAT_32
2166	---help---
2167	  Certain buggy versions of glibc will crash if they are
2168	  presented with a 32-bit vDSO that is not mapped at the address
2169	  indicated in its segment table.
2170
2171	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2172	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2173	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2174	  the only released version with the bug, but OpenSUSE 9
2175	  contains a buggy "glibc 2.3.2".
2176
2177	  The symptom of the bug is that everything crashes on startup, saying:
2178	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2179
2180	  Saying Y here changes the default value of the vdso32 boot
2181	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2182	  This works around the glibc bug but hurts performance.
2183
2184	  If unsure, say N: if you are compiling your own kernel, you
2185	  are unlikely to be using a buggy version of glibc.
2186
2187choice
2188	prompt "vsyscall table for legacy applications"
2189	depends on X86_64
2190	default LEGACY_VSYSCALL_EMULATE
2191	help
2192	  Legacy user code that does not know how to find the vDSO expects
2193	  to be able to issue three syscalls by calling fixed addresses in
2194	  kernel space. Since this location is not randomized with ASLR,
2195	  it can be used to assist security vulnerability exploitation.
2196
2197	  This setting can be changed at boot time via the kernel command
2198	  line parameter vsyscall=[native|emulate|none].
2199
2200	  On a system with recent enough glibc (2.14 or newer) and no
2201	  static binaries, you can say None without a performance penalty
2202	  to improve security.
2203
2204	  If unsure, select "Emulate".
2205
2206	config LEGACY_VSYSCALL_NATIVE
2207		bool "Native"
2208		help
2209		  Actual executable code is located in the fixed vsyscall
2210		  address mapping, implementing time() efficiently. Since
2211		  this makes the mapping executable, it can be used during
2212		  security vulnerability exploitation (traditionally as
2213		  ROP gadgets). This configuration is not recommended.
2214
2215	config LEGACY_VSYSCALL_EMULATE
2216		bool "Emulate"
2217		help
2218		  The kernel traps and emulates calls into the fixed
2219		  vsyscall address mapping. This makes the mapping
2220		  non-executable, but it still contains known contents,
2221		  which could be used in certain rare security vulnerability
2222		  exploits. This configuration is recommended when userspace
2223		  still uses the vsyscall area.
2224
2225	config LEGACY_VSYSCALL_NONE
2226		bool "None"
2227		help
2228		  There will be no vsyscall mapping at all. This will
2229		  eliminate any risk of ASLR bypass due to the vsyscall
2230		  fixed address mapping. Attempts to use the vsyscalls
2231		  will be reported to dmesg, so that either old or
2232		  malicious userspace programs can be identified.
2233
2234endchoice
2235
2236config CMDLINE_BOOL
2237	bool "Built-in kernel command line"
2238	---help---
2239	  Allow for specifying boot arguments to the kernel at
2240	  build time.  On some systems (e.g. embedded ones), it is
2241	  necessary or convenient to provide some or all of the
2242	  kernel boot arguments with the kernel itself (that is,
2243	  to not rely on the boot loader to provide them.)
2244
2245	  To compile command line arguments into the kernel,
2246	  set this option to 'Y', then fill in the
2247	  boot arguments in CONFIG_CMDLINE.
2248
2249	  Systems with fully functional boot loaders (i.e. non-embedded)
2250	  should leave this option set to 'N'.
2251
2252config CMDLINE
2253	string "Built-in kernel command string"
2254	depends on CMDLINE_BOOL
2255	default ""
2256	---help---
2257	  Enter arguments here that should be compiled into the kernel
2258	  image and used at boot time.  If the boot loader provides a
2259	  command line at boot time, it is appended to this string to
2260	  form the full kernel command line, when the system boots.
2261
2262	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2263	  change this behavior.
2264
2265	  In most cases, the command line (whether built-in or provided
2266	  by the boot loader) should specify the device for the root
2267	  file system.
2268
2269config CMDLINE_OVERRIDE
2270	bool "Built-in command line overrides boot loader arguments"
2271	depends on CMDLINE_BOOL
2272	---help---
2273	  Set this option to 'Y' to have the kernel ignore the boot loader
2274	  command line, and use ONLY the built-in command line.
2275
2276	  This is used to work around broken boot loaders.  This should
2277	  be set to 'N' under normal conditions.
2278
2279config MODIFY_LDT_SYSCALL
2280	bool "Enable the LDT (local descriptor table)" if EXPERT
2281	default y
2282	---help---
2283	  Linux can allow user programs to install a per-process x86
2284	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2285	  call.  This is required to run 16-bit or segmented code such as
2286	  DOSEMU or some Wine programs.  It is also used by some very old
2287	  threading libraries.
2288
2289	  Enabling this feature adds a small amount of overhead to
2290	  context switches and increases the low-level kernel attack
2291	  surface.  Disabling it removes the modify_ldt(2) system call.
2292
2293	  Saying 'N' here may make sense for embedded or server kernels.
2294
2295source "kernel/livepatch/Kconfig"
2296
2297endmenu
2298
2299config ARCH_ENABLE_MEMORY_HOTPLUG
2300	def_bool y
2301	depends on X86_64 || (X86_32 && HIGHMEM)
2302
2303config ARCH_ENABLE_MEMORY_HOTREMOVE
2304	def_bool y
2305	depends on MEMORY_HOTPLUG
2306
2307config USE_PERCPU_NUMA_NODE_ID
2308	def_bool y
2309	depends on NUMA
2310
2311config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2312	def_bool y
2313	depends on X86_64 || X86_PAE
2314
2315config ARCH_ENABLE_HUGEPAGE_MIGRATION
2316	def_bool y
2317	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2318
2319menu "Power management and ACPI options"
2320
2321config ARCH_HIBERNATION_HEADER
2322	def_bool y
2323	depends on X86_64 && HIBERNATION
2324
2325source "kernel/power/Kconfig"
2326
2327source "drivers/acpi/Kconfig"
2328
2329source "drivers/sfi/Kconfig"
2330
2331config X86_APM_BOOT
2332	def_bool y
2333	depends on APM
2334
2335menuconfig APM
2336	tristate "APM (Advanced Power Management) BIOS support"
2337	depends on X86_32 && PM_SLEEP
2338	---help---
2339	  APM is a BIOS specification for saving power using several different
2340	  techniques. This is mostly useful for battery powered laptops with
2341	  APM compliant BIOSes. If you say Y here, the system time will be
2342	  reset after a RESUME operation, the /proc/apm device will provide
2343	  battery status information, and user-space programs will receive
2344	  notification of APM "events" (e.g. battery status change).
2345
2346	  If you select "Y" here, you can disable actual use of the APM
2347	  BIOS by passing the "apm=off" option to the kernel at boot time.
2348
2349	  Note that the APM support is almost completely disabled for
2350	  machines with more than one CPU.
2351
2352	  In order to use APM, you will need supporting software. For location
2353	  and more information, read <file:Documentation/power/apm-acpi.txt>
2354	  and the Battery Powered Linux mini-HOWTO, available from
2355	  <http://www.tldp.org/docs.html#howto>.
2356
2357	  This driver does not spin down disk drives (see the hdparm(8)
2358	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2359	  VESA-compliant "green" monitors.
2360
2361	  This driver does not support the TI 4000M TravelMate and the ACER
2362	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2363	  desktop machines also don't have compliant BIOSes, and this driver
2364	  may cause those machines to panic during the boot phase.
2365
2366	  Generally, if you don't have a battery in your machine, there isn't
2367	  much point in using this driver and you should say N. If you get
2368	  random kernel OOPSes or reboots that don't seem to be related to
2369	  anything, try disabling/enabling this option (or disabling/enabling
2370	  APM in your BIOS).
2371
2372	  Some other things you should try when experiencing seemingly random,
2373	  "weird" problems:
2374
2375	  1) make sure that you have enough swap space and that it is
2376	  enabled.
2377	  2) pass the "no-hlt" option to the kernel
2378	  3) switch on floating point emulation in the kernel and pass
2379	  the "no387" option to the kernel
2380	  4) pass the "floppy=nodma" option to the kernel
2381	  5) pass the "mem=4M" option to the kernel (thereby disabling
2382	  all but the first 4 MB of RAM)
2383	  6) make sure that the CPU is not over clocked.
2384	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2385	  8) disable the cache from your BIOS settings
2386	  9) install a fan for the video card or exchange video RAM
2387	  10) install a better fan for the CPU
2388	  11) exchange RAM chips
2389	  12) exchange the motherboard.
2390
2391	  To compile this driver as a module, choose M here: the
2392	  module will be called apm.
2393
2394if APM
2395
2396config APM_IGNORE_USER_SUSPEND
2397	bool "Ignore USER SUSPEND"
2398	---help---
2399	  This option will ignore USER SUSPEND requests. On machines with a
2400	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2401	  series notebooks, it is necessary to say Y because of a BIOS bug.
2402
2403config APM_DO_ENABLE
2404	bool "Enable PM at boot time"
2405	---help---
2406	  Enable APM features at boot time. From page 36 of the APM BIOS
2407	  specification: "When disabled, the APM BIOS does not automatically
2408	  power manage devices, enter the Standby State, enter the Suspend
2409	  State, or take power saving steps in response to CPU Idle calls."
2410	  This driver will make CPU Idle calls when Linux is idle (unless this
2411	  feature is turned off -- see "Do CPU IDLE calls", below). This
2412	  should always save battery power, but more complicated APM features
2413	  will be dependent on your BIOS implementation. You may need to turn
2414	  this option off if your computer hangs at boot time when using APM
2415	  support, or if it beeps continuously instead of suspending. Turn
2416	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2417	  T400CDT. This is off by default since most machines do fine without
2418	  this feature.
2419
2420config APM_CPU_IDLE
2421	depends on CPU_IDLE
2422	bool "Make CPU Idle calls when idle"
2423	---help---
2424	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2425	  On some machines, this can activate improved power savings, such as
2426	  a slowed CPU clock rate, when the machine is idle. These idle calls
2427	  are made after the idle loop has run for some length of time (e.g.,
2428	  333 mS). On some machines, this will cause a hang at boot time or
2429	  whenever the CPU becomes idle. (On machines with more than one CPU,
2430	  this option does nothing.)
2431
2432config APM_DISPLAY_BLANK
2433	bool "Enable console blanking using APM"
2434	---help---
2435	  Enable console blanking using the APM. Some laptops can use this to
2436	  turn off the LCD backlight when the screen blanker of the Linux
2437	  virtual console blanks the screen. Note that this is only used by
2438	  the virtual console screen blanker, and won't turn off the backlight
2439	  when using the X Window system. This also doesn't have anything to
2440	  do with your VESA-compliant power-saving monitor. Further, this
2441	  option doesn't work for all laptops -- it might not turn off your
2442	  backlight at all, or it might print a lot of errors to the console,
2443	  especially if you are using gpm.
2444
2445config APM_ALLOW_INTS
2446	bool "Allow interrupts during APM BIOS calls"
2447	---help---
2448	  Normally we disable external interrupts while we are making calls to
2449	  the APM BIOS as a measure to lessen the effects of a badly behaving
2450	  BIOS implementation.  The BIOS should reenable interrupts if it
2451	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2452	  many of the newer IBM Thinkpads.  If you experience hangs when you
2453	  suspend, try setting this to Y.  Otherwise, say N.
2454
2455endif # APM
2456
2457source "drivers/cpufreq/Kconfig"
2458
2459source "drivers/cpuidle/Kconfig"
2460
2461source "drivers/idle/Kconfig"
2462
2463endmenu
2464
2465
2466menu "Bus options (PCI etc.)"
2467
2468config PCI
2469	bool "PCI support"
2470	default y
2471	---help---
2472	  Find out whether you have a PCI motherboard. PCI is the name of a
2473	  bus system, i.e. the way the CPU talks to the other stuff inside
2474	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2475	  VESA. If you have PCI, say Y, otherwise N.
2476
2477choice
2478	prompt "PCI access mode"
2479	depends on X86_32 && PCI
2480	default PCI_GOANY
2481	---help---
2482	  On PCI systems, the BIOS can be used to detect the PCI devices and
2483	  determine their configuration. However, some old PCI motherboards
2484	  have BIOS bugs and may crash if this is done. Also, some embedded
2485	  PCI-based systems don't have any BIOS at all. Linux can also try to
2486	  detect the PCI hardware directly without using the BIOS.
2487
2488	  With this option, you can specify how Linux should detect the
2489	  PCI devices. If you choose "BIOS", the BIOS will be used,
2490	  if you choose "Direct", the BIOS won't be used, and if you
2491	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2492	  If you choose "Any", the kernel will try MMCONFIG, then the
2493	  direct access method and falls back to the BIOS if that doesn't
2494	  work. If unsure, go with the default, which is "Any".
2495
2496config PCI_GOBIOS
2497	bool "BIOS"
2498
2499config PCI_GOMMCONFIG
2500	bool "MMConfig"
2501
2502config PCI_GODIRECT
2503	bool "Direct"
2504
2505config PCI_GOOLPC
2506	bool "OLPC XO-1"
2507	depends on OLPC
2508
2509config PCI_GOANY
2510	bool "Any"
2511
2512endchoice
2513
2514config PCI_BIOS
2515	def_bool y
2516	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2517
2518# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2519config PCI_DIRECT
2520	def_bool y
2521	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2522
2523config PCI_MMCONFIG
2524	def_bool y
2525	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2526
2527config PCI_OLPC
2528	def_bool y
2529	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2530
2531config PCI_XEN
2532	def_bool y
2533	depends on PCI && XEN
2534	select SWIOTLB_XEN
2535
2536config PCI_DOMAINS
2537	def_bool y
2538	depends on PCI
2539
2540config PCI_MMCONFIG
2541	bool "Support mmconfig PCI config space access"
2542	depends on X86_64 && PCI && ACPI
2543
2544config PCI_CNB20LE_QUIRK
2545	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2546	depends on PCI
2547	help
2548	  Read the PCI windows out of the CNB20LE host bridge. This allows
2549	  PCI hotplug to work on systems with the CNB20LE chipset which do
2550	  not have ACPI.
2551
2552	  There's no public spec for this chipset, and this functionality
2553	  is known to be incomplete.
2554
2555	  You should say N unless you know you need this.
2556
2557source "drivers/pci/Kconfig"
2558
2559config ISA_BUS
2560	bool "ISA-style bus support on modern systems" if EXPERT
2561	select ISA_BUS_API
2562	help
2563	  Enables ISA-style drivers on modern systems. This is necessary to
2564	  support PC/104 devices on X86_64 platforms.
2565
2566	  If unsure, say N.
2567
2568# x86_64 have no ISA slots, but can have ISA-style DMA.
2569config ISA_DMA_API
2570	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2571	default y
2572	help
2573	  Enables ISA-style DMA support for devices requiring such controllers.
2574	  If unsure, say Y.
2575
2576if X86_32
2577
2578config ISA
2579	bool "ISA support"
2580	---help---
2581	  Find out whether you have ISA slots on your motherboard.  ISA is the
2582	  name of a bus system, i.e. the way the CPU talks to the other stuff
2583	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2584	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2585	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2586
2587config EISA
2588	bool "EISA support"
2589	depends on ISA
2590	---help---
2591	  The Extended Industry Standard Architecture (EISA) bus was
2592	  developed as an open alternative to the IBM MicroChannel bus.
2593
2594	  The EISA bus provided some of the features of the IBM MicroChannel
2595	  bus while maintaining backward compatibility with cards made for
2596	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2597	  1995 when it was made obsolete by the PCI bus.
2598
2599	  Say Y here if you are building a kernel for an EISA-based machine.
2600
2601	  Otherwise, say N.
2602
2603source "drivers/eisa/Kconfig"
2604
2605config SCx200
2606	tristate "NatSemi SCx200 support"
2607	---help---
2608	  This provides basic support for National Semiconductor's
2609	  (now AMD's) Geode processors.  The driver probes for the
2610	  PCI-IDs of several on-chip devices, so its a good dependency
2611	  for other scx200_* drivers.
2612
2613	  If compiled as a module, the driver is named scx200.
2614
2615config SCx200HR_TIMER
2616	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2617	depends on SCx200
2618	default y
2619	---help---
2620	  This driver provides a clocksource built upon the on-chip
2621	  27MHz high-resolution timer.  Its also a workaround for
2622	  NSC Geode SC-1100's buggy TSC, which loses time when the
2623	  processor goes idle (as is done by the scheduler).  The
2624	  other workaround is idle=poll boot option.
2625
2626config OLPC
2627	bool "One Laptop Per Child support"
2628	depends on !X86_PAE
2629	select GPIOLIB
2630	select OF
2631	select OF_PROMTREE
2632	select IRQ_DOMAIN
2633	---help---
2634	  Add support for detecting the unique features of the OLPC
2635	  XO hardware.
2636
2637config OLPC_XO1_PM
2638	bool "OLPC XO-1 Power Management"
2639	depends on OLPC && MFD_CS5535 && PM_SLEEP
2640	select MFD_CORE
2641	---help---
2642	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2643
2644config OLPC_XO1_RTC
2645	bool "OLPC XO-1 Real Time Clock"
2646	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2647	---help---
2648	  Add support for the XO-1 real time clock, which can be used as a
2649	  programmable wakeup source.
2650
2651config OLPC_XO1_SCI
2652	bool "OLPC XO-1 SCI extras"
2653	depends on OLPC && OLPC_XO1_PM
2654	depends on INPUT=y
2655	select POWER_SUPPLY
2656	select GPIO_CS5535
2657	select MFD_CORE
2658	---help---
2659	  Add support for SCI-based features of the OLPC XO-1 laptop:
2660	   - EC-driven system wakeups
2661	   - Power button
2662	   - Ebook switch
2663	   - Lid switch
2664	   - AC adapter status updates
2665	   - Battery status updates
2666
2667config OLPC_XO15_SCI
2668	bool "OLPC XO-1.5 SCI extras"
2669	depends on OLPC && ACPI
2670	select POWER_SUPPLY
2671	---help---
2672	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2673	   - EC-driven system wakeups
2674	   - AC adapter status updates
2675	   - Battery status updates
2676
2677config ALIX
2678	bool "PCEngines ALIX System Support (LED setup)"
2679	select GPIOLIB
2680	---help---
2681	  This option enables system support for the PCEngines ALIX.
2682	  At present this just sets up LEDs for GPIO control on
2683	  ALIX2/3/6 boards.  However, other system specific setup should
2684	  get added here.
2685
2686	  Note: You must still enable the drivers for GPIO and LED support
2687	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2688
2689	  Note: You have to set alix.force=1 for boards with Award BIOS.
2690
2691config NET5501
2692	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2693	select GPIOLIB
2694	---help---
2695	  This option enables system support for the Soekris Engineering net5501.
2696
2697config GEOS
2698	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2699	select GPIOLIB
2700	depends on DMI
2701	---help---
2702	  This option enables system support for the Traverse Technologies GEOS.
2703
2704config TS5500
2705	bool "Technologic Systems TS-5500 platform support"
2706	depends on MELAN
2707	select CHECK_SIGNATURE
2708	select NEW_LEDS
2709	select LEDS_CLASS
2710	---help---
2711	  This option enables system support for the Technologic Systems TS-5500.
2712
2713endif # X86_32
2714
2715config AMD_NB
2716	def_bool y
2717	depends on CPU_SUP_AMD && PCI
2718
2719source "drivers/pcmcia/Kconfig"
2720
2721config RAPIDIO
2722	tristate "RapidIO support"
2723	depends on PCI
2724	default n
2725	help
2726	  If enabled this option will include drivers and the core
2727	  infrastructure code to support RapidIO interconnect devices.
2728
2729source "drivers/rapidio/Kconfig"
2730
2731config X86_SYSFB
2732	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2733	help
2734	  Firmwares often provide initial graphics framebuffers so the BIOS,
2735	  bootloader or kernel can show basic video-output during boot for
2736	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2737	  Extensions and EFI-framebuffers for this, which are mostly limited
2738	  to x86.
2739	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2740	  framebuffers so the new generic system-framebuffer drivers can be
2741	  used on x86. If the framebuffer is not compatible with the generic
2742	  modes, it is adverticed as fallback platform framebuffer so legacy
2743	  drivers like efifb, vesafb and uvesafb can pick it up.
2744	  If this option is not selected, all system framebuffers are always
2745	  marked as fallback platform framebuffers as usual.
2746
2747	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2748	  not be able to pick up generic system framebuffers if this option
2749	  is selected. You are highly encouraged to enable simplefb as
2750	  replacement if you select this option. simplefb can correctly deal
2751	  with generic system framebuffers. But you should still keep vesafb
2752	  and others enabled as fallback if a system framebuffer is
2753	  incompatible with simplefb.
2754
2755	  If unsure, say Y.
2756
2757endmenu
2758
2759
2760menu "Executable file formats / Emulations"
2761
2762source "fs/Kconfig.binfmt"
2763
2764config IA32_EMULATION
2765	bool "IA32 Emulation"
2766	depends on X86_64
2767	select ARCH_WANT_OLD_COMPAT_IPC
2768	select BINFMT_ELF
2769	select COMPAT_BINFMT_ELF
2770	select COMPAT_OLD_SIGACTION
2771	---help---
2772	  Include code to run legacy 32-bit programs under a
2773	  64-bit kernel. You should likely turn this on, unless you're
2774	  100% sure that you don't have any 32-bit programs left.
2775
2776config IA32_AOUT
2777	tristate "IA32 a.out support"
2778	depends on IA32_EMULATION
2779	---help---
2780	  Support old a.out binaries in the 32bit emulation.
2781
2782config X86_X32
2783	bool "x32 ABI for 64-bit mode"
2784	depends on X86_64
2785	---help---
2786	  Include code to run binaries for the x32 native 32-bit ABI
2787	  for 64-bit processors.  An x32 process gets access to the
2788	  full 64-bit register file and wide data path while leaving
2789	  pointers at 32 bits for smaller memory footprint.
2790
2791	  You will need a recent binutils (2.22 or later) with
2792	  elf32_x86_64 support enabled to compile a kernel with this
2793	  option set.
2794
2795config COMPAT_32
2796	def_bool y
2797	depends on IA32_EMULATION || X86_32
2798	select HAVE_UID16
2799	select OLD_SIGSUSPEND3
2800
2801config COMPAT
2802	def_bool y
2803	depends on IA32_EMULATION || X86_X32
2804
2805if COMPAT
2806config COMPAT_FOR_U64_ALIGNMENT
2807	def_bool y
2808
2809config SYSVIPC_COMPAT
2810	def_bool y
2811	depends on SYSVIPC
2812endif
2813
2814endmenu
2815
2816
2817config HAVE_ATOMIC_IOMAP
2818	def_bool y
2819	depends on X86_32
2820
2821config X86_DEV_DMA_OPS
2822	bool
2823	depends on X86_64 || STA2X11
2824
2825config X86_DMA_REMAP
2826	bool
2827	depends on STA2X11
2828
2829config HAVE_GENERIC_GUP
2830	def_bool y
2831
2832source "net/Kconfig"
2833
2834source "drivers/Kconfig"
2835
2836source "drivers/firmware/Kconfig"
2837
2838source "fs/Kconfig"
2839
2840source "arch/x86/Kconfig.debug"
2841
2842source "security/Kconfig"
2843
2844source "crypto/Kconfig"
2845
2846source "arch/x86/kvm/Kconfig"
2847
2848source "lib/Kconfig"
2849