xref: /linux/arch/x86/Kconfig (revision 37cb8e1f8e10c6e9bd2a1b95cdda0620a21b0551)
1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if ARCH = "x86"
5	default ARCH != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_AOUT
18	select HAVE_GENERIC_DMA_COHERENT
19	select MODULES_USE_ELF_REL
20	select OLD_SIGACTION
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select X86_DEV_DMA_OPS
32
33#
34# Arch settings
35#
36# ( Note that options that are marked 'if X86_64' could in principle be
37#   ported to 32-bit as well. )
38#
39config X86
40	def_bool y
41	#
42	# Note: keep this list sorted alphabetically
43	#
44	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
45	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
46	select ANON_INODES
47	select ARCH_CLOCKSOURCE_DATA
48	select ARCH_DISCARD_MEMBLOCK
49	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
50	select ARCH_HAS_DEBUG_VIRTUAL
51	select ARCH_HAS_DEVMEM_IS_ALLOWED
52	select ARCH_HAS_ELF_RANDOMIZE
53	select ARCH_HAS_FAST_MULTIPLIER
54	select ARCH_HAS_FORTIFY_SOURCE
55	select ARCH_HAS_GCOV_PROFILE_ALL
56	select ARCH_HAS_KCOV			if X86_64
57	select ARCH_HAS_PMEM_API		if X86_64
58	# Causing hangs/crashes, see the commit that added this change for details.
59	select ARCH_HAS_REFCOUNT
60	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
61	select ARCH_HAS_SET_MEMORY
62	select ARCH_HAS_SG_CHAIN
63	select ARCH_HAS_STRICT_KERNEL_RWX
64	select ARCH_HAS_STRICT_MODULE_RWX
65	select ARCH_HAS_UBSAN_SANITIZE_ALL
66	select ARCH_HAS_ZONE_DEVICE		if X86_64
67	select ARCH_HAVE_NMI_SAFE_CMPXCHG
68	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
69	select ARCH_MIGHT_HAVE_PC_PARPORT
70	select ARCH_MIGHT_HAVE_PC_SERIO
71	select ARCH_SUPPORTS_ATOMIC_RMW
72	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
73	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
74	select ARCH_USE_BUILTIN_BSWAP
75	select ARCH_USE_QUEUED_RWLOCKS
76	select ARCH_USE_QUEUED_SPINLOCKS
77	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
78	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
79	select ARCH_WANTS_THP_SWAP		if X86_64
80	select BUILDTIME_EXTABLE_SORT
81	select CLKEVT_I8253
82	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
83	select CLOCKSOURCE_WATCHDOG
84	select DCACHE_WORD_ACCESS
85	select EDAC_ATOMIC_SCRUB
86	select EDAC_SUPPORT
87	select GENERIC_CLOCKEVENTS
88	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
89	select GENERIC_CLOCKEVENTS_MIN_ADJUST
90	select GENERIC_CMOS_UPDATE
91	select GENERIC_CPU_AUTOPROBE
92	select GENERIC_EARLY_IOREMAP
93	select GENERIC_FIND_FIRST_BIT
94	select GENERIC_IOMAP
95	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
96	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
97	select GENERIC_IRQ_MIGRATION		if SMP
98	select GENERIC_IRQ_PROBE
99	select GENERIC_IRQ_RESERVATION_MODE
100	select GENERIC_IRQ_SHOW
101	select GENERIC_PENDING_IRQ		if SMP
102	select GENERIC_SMP_IDLE_THREAD
103	select GENERIC_STRNCPY_FROM_USER
104	select GENERIC_STRNLEN_USER
105	select GENERIC_TIME_VSYSCALL
106	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
107	select HAVE_ACPI_APEI			if ACPI
108	select HAVE_ACPI_APEI_NMI		if ACPI
109	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
110	select HAVE_ARCH_AUDITSYSCALL
111	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
112	select HAVE_ARCH_JUMP_LABEL
113	select HAVE_ARCH_KASAN			if X86_64 && SPARSEMEM_VMEMMAP
114	select HAVE_ARCH_KGDB
115	select HAVE_ARCH_KMEMCHECK
116	select HAVE_ARCH_MMAP_RND_BITS		if MMU
117	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
118	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
119	select HAVE_ARCH_SECCOMP_FILTER
120	select HAVE_ARCH_TRACEHOOK
121	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
122	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
123	select HAVE_ARCH_VMAP_STACK		if X86_64
124	select HAVE_ARCH_WITHIN_STACK_FRAMES
125	select HAVE_CC_STACKPROTECTOR
126	select HAVE_CMPXCHG_DOUBLE
127	select HAVE_CMPXCHG_LOCAL
128	select HAVE_CONTEXT_TRACKING		if X86_64
129	select HAVE_COPY_THREAD_TLS
130	select HAVE_C_RECORDMCOUNT
131	select HAVE_DEBUG_KMEMLEAK
132	select HAVE_DEBUG_STACKOVERFLOW
133	select HAVE_DMA_API_DEBUG
134	select HAVE_DMA_CONTIGUOUS
135	select HAVE_DYNAMIC_FTRACE
136	select HAVE_DYNAMIC_FTRACE_WITH_REGS
137	select HAVE_EBPF_JIT			if X86_64
138	select HAVE_EFFICIENT_UNALIGNED_ACCESS
139	select HAVE_EXIT_THREAD
140	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
141	select HAVE_FTRACE_MCOUNT_RECORD
142	select HAVE_FUNCTION_GRAPH_TRACER
143	select HAVE_FUNCTION_TRACER
144	select HAVE_GCC_PLUGINS
145	select HAVE_HW_BREAKPOINT
146	select HAVE_IDE
147	select HAVE_IOREMAP_PROT
148	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
149	select HAVE_IRQ_TIME_ACCOUNTING
150	select HAVE_KERNEL_BZIP2
151	select HAVE_KERNEL_GZIP
152	select HAVE_KERNEL_LZ4
153	select HAVE_KERNEL_LZMA
154	select HAVE_KERNEL_LZO
155	select HAVE_KERNEL_XZ
156	select HAVE_KPROBES
157	select HAVE_KPROBES_ON_FTRACE
158	select HAVE_KRETPROBES
159	select HAVE_KVM
160	select HAVE_LIVEPATCH			if X86_64
161	select HAVE_MEMBLOCK
162	select HAVE_MEMBLOCK_NODE_MAP
163	select HAVE_MIXED_BREAKPOINTS_REGS
164	select HAVE_MOD_ARCH_SPECIFIC
165	select HAVE_NMI
166	select HAVE_OPROFILE
167	select HAVE_OPTPROBES
168	select HAVE_PCSPKR_PLATFORM
169	select HAVE_PERF_EVENTS
170	select HAVE_PERF_EVENTS_NMI
171	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
172	select HAVE_PERF_REGS
173	select HAVE_PERF_USER_STACK_DUMP
174	select HAVE_RCU_TABLE_FREE
175	select HAVE_REGS_AND_STACK_ACCESS_API
176	select HAVE_RELIABLE_STACKTRACE		if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
177	select HAVE_STACK_VALIDATION		if X86_64
178	select HAVE_SYSCALL_TRACEPOINTS
179	select HAVE_UNSTABLE_SCHED_CLOCK
180	select HAVE_USER_RETURN_NOTIFIER
181	select IRQ_FORCED_THREADING
182	select PCI_LOCKLESS_CONFIG
183	select PERF_EVENTS
184	select RTC_LIB
185	select RTC_MC146818_LIB
186	select SPARSE_IRQ
187	select SRCU
188	select SYSCTL_EXCEPTION_TRACE
189	select THREAD_INFO_IN_TASK
190	select USER_STACKTRACE_SUPPORT
191	select VIRT_TO_BUS
192	select X86_FEATURE_NAMES		if PROC_FS
193
194config INSTRUCTION_DECODER
195	def_bool y
196	depends on KPROBES || PERF_EVENTS || UPROBES
197
198config OUTPUT_FORMAT
199	string
200	default "elf32-i386" if X86_32
201	default "elf64-x86-64" if X86_64
202
203config ARCH_DEFCONFIG
204	string
205	default "arch/x86/configs/i386_defconfig" if X86_32
206	default "arch/x86/configs/x86_64_defconfig" if X86_64
207
208config LOCKDEP_SUPPORT
209	def_bool y
210
211config STACKTRACE_SUPPORT
212	def_bool y
213
214config MMU
215	def_bool y
216
217config ARCH_MMAP_RND_BITS_MIN
218	default 28 if 64BIT
219	default 8
220
221config ARCH_MMAP_RND_BITS_MAX
222	default 32 if 64BIT
223	default 16
224
225config ARCH_MMAP_RND_COMPAT_BITS_MIN
226	default 8
227
228config ARCH_MMAP_RND_COMPAT_BITS_MAX
229	default 16
230
231config SBUS
232	bool
233
234config NEED_DMA_MAP_STATE
235	def_bool y
236	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
237
238config NEED_SG_DMA_LENGTH
239	def_bool y
240
241config GENERIC_ISA_DMA
242	def_bool y
243	depends on ISA_DMA_API
244
245config GENERIC_BUG
246	def_bool y
247	depends on BUG
248	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
249
250config GENERIC_BUG_RELATIVE_POINTERS
251	bool
252
253config GENERIC_HWEIGHT
254	def_bool y
255
256config ARCH_MAY_HAVE_PC_FDC
257	def_bool y
258	depends on ISA_DMA_API
259
260config RWSEM_XCHGADD_ALGORITHM
261	def_bool y
262
263config GENERIC_CALIBRATE_DELAY
264	def_bool y
265
266config ARCH_HAS_CPU_RELAX
267	def_bool y
268
269config ARCH_HAS_CACHE_LINE_SIZE
270	def_bool y
271
272config HAVE_SETUP_PER_CPU_AREA
273	def_bool y
274
275config NEED_PER_CPU_EMBED_FIRST_CHUNK
276	def_bool y
277
278config NEED_PER_CPU_PAGE_FIRST_CHUNK
279	def_bool y
280
281config ARCH_HIBERNATION_POSSIBLE
282	def_bool y
283
284config ARCH_SUSPEND_POSSIBLE
285	def_bool y
286
287config ARCH_WANT_HUGE_PMD_SHARE
288	def_bool y
289
290config ARCH_WANT_GENERAL_HUGETLB
291	def_bool y
292
293config ZONE_DMA32
294	def_bool y if X86_64
295
296config AUDIT_ARCH
297	def_bool y if X86_64
298
299config ARCH_SUPPORTS_OPTIMIZED_INLINING
300	def_bool y
301
302config ARCH_SUPPORTS_DEBUG_PAGEALLOC
303	def_bool y
304
305config KASAN_SHADOW_OFFSET
306	hex
307	depends on KASAN
308	default 0xdffffc0000000000
309
310config HAVE_INTEL_TXT
311	def_bool y
312	depends on INTEL_IOMMU && ACPI
313
314config X86_32_SMP
315	def_bool y
316	depends on X86_32 && SMP
317
318config X86_64_SMP
319	def_bool y
320	depends on X86_64 && SMP
321
322config X86_32_LAZY_GS
323	def_bool y
324	depends on X86_32 && !CC_STACKPROTECTOR
325
326config ARCH_SUPPORTS_UPROBES
327	def_bool y
328
329config FIX_EARLYCON_MEM
330	def_bool y
331
332config PGTABLE_LEVELS
333	int
334	default 5 if X86_5LEVEL
335	default 4 if X86_64
336	default 3 if X86_PAE
337	default 2
338
339source "init/Kconfig"
340source "kernel/Kconfig.freezer"
341
342menu "Processor type and features"
343
344config ZONE_DMA
345	bool "DMA memory allocation support" if EXPERT
346	default y
347	help
348	  DMA memory allocation support allows devices with less than 32-bit
349	  addressing to allocate within the first 16MB of address space.
350	  Disable if no such devices will be used.
351
352	  If unsure, say Y.
353
354config SMP
355	bool "Symmetric multi-processing support"
356	---help---
357	  This enables support for systems with more than one CPU. If you have
358	  a system with only one CPU, say N. If you have a system with more
359	  than one CPU, say Y.
360
361	  If you say N here, the kernel will run on uni- and multiprocessor
362	  machines, but will use only one CPU of a multiprocessor machine. If
363	  you say Y here, the kernel will run on many, but not all,
364	  uniprocessor machines. On a uniprocessor machine, the kernel
365	  will run faster if you say N here.
366
367	  Note that if you say Y here and choose architecture "586" or
368	  "Pentium" under "Processor family", the kernel will not work on 486
369	  architectures. Similarly, multiprocessor kernels for the "PPro"
370	  architecture may not work on all Pentium based boards.
371
372	  People using multiprocessor machines who say Y here should also say
373	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
374	  Management" code will be disabled if you say Y here.
375
376	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
377	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
378	  <http://www.tldp.org/docs.html#howto>.
379
380	  If you don't know what to do here, say N.
381
382config X86_FEATURE_NAMES
383	bool "Processor feature human-readable names" if EMBEDDED
384	default y
385	---help---
386	  This option compiles in a table of x86 feature bits and corresponding
387	  names.  This is required to support /proc/cpuinfo and a few kernel
388	  messages.  You can disable this to save space, at the expense of
389	  making those few kernel messages show numeric feature bits instead.
390
391	  If in doubt, say Y.
392
393config X86_FAST_FEATURE_TESTS
394	bool "Fast CPU feature tests" if EMBEDDED
395	default y
396	---help---
397	  Some fast-paths in the kernel depend on the capabilities of the CPU.
398	  Say Y here for the kernel to patch in the appropriate code at runtime
399	  based on the capabilities of the CPU. The infrastructure for patching
400	  code at runtime takes up some additional space; space-constrained
401	  embedded systems may wish to say N here to produce smaller, slightly
402	  slower code.
403
404config X86_X2APIC
405	bool "Support x2apic"
406	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
407	---help---
408	  This enables x2apic support on CPUs that have this feature.
409
410	  This allows 32-bit apic IDs (so it can support very large systems),
411	  and accesses the local apic via MSRs not via mmio.
412
413	  If you don't know what to do here, say N.
414
415config X86_MPPARSE
416	bool "Enable MPS table" if ACPI || SFI
417	default y
418	depends on X86_LOCAL_APIC
419	---help---
420	  For old smp systems that do not have proper acpi support. Newer systems
421	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
422
423config X86_BIGSMP
424	bool "Support for big SMP systems with more than 8 CPUs"
425	depends on X86_32 && SMP
426	---help---
427	  This option is needed for the systems that have more than 8 CPUs
428
429config GOLDFISH
430       def_bool y
431       depends on X86_GOLDFISH
432
433config INTEL_RDT
434	bool "Intel Resource Director Technology support"
435	default n
436	depends on X86 && CPU_SUP_INTEL
437	select KERNFS
438	help
439	  Select to enable resource allocation and monitoring which are
440	  sub-features of Intel Resource Director Technology(RDT). More
441	  information about RDT can be found in the Intel x86
442	  Architecture Software Developer Manual.
443
444	  Say N if unsure.
445
446if X86_32
447config X86_EXTENDED_PLATFORM
448	bool "Support for extended (non-PC) x86 platforms"
449	default y
450	---help---
451	  If you disable this option then the kernel will only support
452	  standard PC platforms. (which covers the vast majority of
453	  systems out there.)
454
455	  If you enable this option then you'll be able to select support
456	  for the following (non-PC) 32 bit x86 platforms:
457		Goldfish (Android emulator)
458		AMD Elan
459		RDC R-321x SoC
460		SGI 320/540 (Visual Workstation)
461		STA2X11-based (e.g. Northville)
462		Moorestown MID devices
463
464	  If you have one of these systems, or if you want to build a
465	  generic distribution kernel, say Y here - otherwise say N.
466endif
467
468if X86_64
469config X86_EXTENDED_PLATFORM
470	bool "Support for extended (non-PC) x86 platforms"
471	default y
472	---help---
473	  If you disable this option then the kernel will only support
474	  standard PC platforms. (which covers the vast majority of
475	  systems out there.)
476
477	  If you enable this option then you'll be able to select support
478	  for the following (non-PC) 64 bit x86 platforms:
479		Numascale NumaChip
480		ScaleMP vSMP
481		SGI Ultraviolet
482
483	  If you have one of these systems, or if you want to build a
484	  generic distribution kernel, say Y here - otherwise say N.
485endif
486# This is an alphabetically sorted list of 64 bit extended platforms
487# Please maintain the alphabetic order if and when there are additions
488config X86_NUMACHIP
489	bool "Numascale NumaChip"
490	depends on X86_64
491	depends on X86_EXTENDED_PLATFORM
492	depends on NUMA
493	depends on SMP
494	depends on X86_X2APIC
495	depends on PCI_MMCONFIG
496	---help---
497	  Adds support for Numascale NumaChip large-SMP systems. Needed to
498	  enable more than ~168 cores.
499	  If you don't have one of these, you should say N here.
500
501config X86_VSMP
502	bool "ScaleMP vSMP"
503	select HYPERVISOR_GUEST
504	select PARAVIRT
505	depends on X86_64 && PCI
506	depends on X86_EXTENDED_PLATFORM
507	depends on SMP
508	---help---
509	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
510	  supposed to run on these EM64T-based machines.  Only choose this option
511	  if you have one of these machines.
512
513config X86_UV
514	bool "SGI Ultraviolet"
515	depends on X86_64
516	depends on X86_EXTENDED_PLATFORM
517	depends on NUMA
518	depends on EFI
519	depends on X86_X2APIC
520	depends on PCI
521	---help---
522	  This option is needed in order to support SGI Ultraviolet systems.
523	  If you don't have one of these, you should say N here.
524
525# Following is an alphabetically sorted list of 32 bit extended platforms
526# Please maintain the alphabetic order if and when there are additions
527
528config X86_GOLDFISH
529       bool "Goldfish (Virtual Platform)"
530       depends on X86_EXTENDED_PLATFORM
531       ---help---
532	 Enable support for the Goldfish virtual platform used primarily
533	 for Android development. Unless you are building for the Android
534	 Goldfish emulator say N here.
535
536config X86_INTEL_CE
537	bool "CE4100 TV platform"
538	depends on PCI
539	depends on PCI_GODIRECT
540	depends on X86_IO_APIC
541	depends on X86_32
542	depends on X86_EXTENDED_PLATFORM
543	select X86_REBOOTFIXUPS
544	select OF
545	select OF_EARLY_FLATTREE
546	---help---
547	  Select for the Intel CE media processor (CE4100) SOC.
548	  This option compiles in support for the CE4100 SOC for settop
549	  boxes and media devices.
550
551config X86_INTEL_MID
552	bool "Intel MID platform support"
553	depends on X86_EXTENDED_PLATFORM
554	depends on X86_PLATFORM_DEVICES
555	depends on PCI
556	depends on X86_64 || (PCI_GOANY && X86_32)
557	depends on X86_IO_APIC
558	select SFI
559	select I2C
560	select DW_APB_TIMER
561	select APB_TIMER
562	select INTEL_SCU_IPC
563	select MFD_INTEL_MSIC
564	---help---
565	  Select to build a kernel capable of supporting Intel MID (Mobile
566	  Internet Device) platform systems which do not have the PCI legacy
567	  interfaces. If you are building for a PC class system say N here.
568
569	  Intel MID platforms are based on an Intel processor and chipset which
570	  consume less power than most of the x86 derivatives.
571
572config X86_INTEL_QUARK
573	bool "Intel Quark platform support"
574	depends on X86_32
575	depends on X86_EXTENDED_PLATFORM
576	depends on X86_PLATFORM_DEVICES
577	depends on X86_TSC
578	depends on PCI
579	depends on PCI_GOANY
580	depends on X86_IO_APIC
581	select IOSF_MBI
582	select INTEL_IMR
583	select COMMON_CLK
584	---help---
585	  Select to include support for Quark X1000 SoC.
586	  Say Y here if you have a Quark based system such as the Arduino
587	  compatible Intel Galileo.
588
589config X86_INTEL_LPSS
590	bool "Intel Low Power Subsystem Support"
591	depends on X86 && ACPI
592	select COMMON_CLK
593	select PINCTRL
594	select IOSF_MBI
595	---help---
596	  Select to build support for Intel Low Power Subsystem such as
597	  found on Intel Lynxpoint PCH. Selecting this option enables
598	  things like clock tree (common clock framework) and pincontrol
599	  which are needed by the LPSS peripheral drivers.
600
601config X86_AMD_PLATFORM_DEVICE
602	bool "AMD ACPI2Platform devices support"
603	depends on ACPI
604	select COMMON_CLK
605	select PINCTRL
606	---help---
607	  Select to interpret AMD specific ACPI device to platform device
608	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
609	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
610	  implemented under PINCTRL subsystem.
611
612config IOSF_MBI
613	tristate "Intel SoC IOSF Sideband support for SoC platforms"
614	depends on PCI
615	---help---
616	  This option enables sideband register access support for Intel SoC
617	  platforms. On these platforms the IOSF sideband is used in lieu of
618	  MSR's for some register accesses, mostly but not limited to thermal
619	  and power. Drivers may query the availability of this device to
620	  determine if they need the sideband in order to work on these
621	  platforms. The sideband is available on the following SoC products.
622	  This list is not meant to be exclusive.
623	   - BayTrail
624	   - Braswell
625	   - Quark
626
627	  You should say Y if you are running a kernel on one of these SoC's.
628
629config IOSF_MBI_DEBUG
630	bool "Enable IOSF sideband access through debugfs"
631	depends on IOSF_MBI && DEBUG_FS
632	---help---
633	  Select this option to expose the IOSF sideband access registers (MCR,
634	  MDR, MCRX) through debugfs to write and read register information from
635	  different units on the SoC. This is most useful for obtaining device
636	  state information for debug and analysis. As this is a general access
637	  mechanism, users of this option would have specific knowledge of the
638	  device they want to access.
639
640	  If you don't require the option or are in doubt, say N.
641
642config X86_RDC321X
643	bool "RDC R-321x SoC"
644	depends on X86_32
645	depends on X86_EXTENDED_PLATFORM
646	select M486
647	select X86_REBOOTFIXUPS
648	---help---
649	  This option is needed for RDC R-321x system-on-chip, also known
650	  as R-8610-(G).
651	  If you don't have one of these chips, you should say N here.
652
653config X86_32_NON_STANDARD
654	bool "Support non-standard 32-bit SMP architectures"
655	depends on X86_32 && SMP
656	depends on X86_EXTENDED_PLATFORM
657	---help---
658	  This option compiles in the bigsmp and STA2X11 default
659	  subarchitectures.  It is intended for a generic binary
660	  kernel. If you select them all, kernel will probe it one by
661	  one and will fallback to default.
662
663# Alphabetically sorted list of Non standard 32 bit platforms
664
665config X86_SUPPORTS_MEMORY_FAILURE
666	def_bool y
667	# MCE code calls memory_failure():
668	depends on X86_MCE
669	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
670	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
671	depends on X86_64 || !SPARSEMEM
672	select ARCH_SUPPORTS_MEMORY_FAILURE
673
674config STA2X11
675	bool "STA2X11 Companion Chip Support"
676	depends on X86_32_NON_STANDARD && PCI
677	select X86_DEV_DMA_OPS
678	select X86_DMA_REMAP
679	select SWIOTLB
680	select MFD_STA2X11
681	select GPIOLIB
682	default n
683	---help---
684	  This adds support for boards based on the STA2X11 IO-Hub,
685	  a.k.a. "ConneXt". The chip is used in place of the standard
686	  PC chipset, so all "standard" peripherals are missing. If this
687	  option is selected the kernel will still be able to boot on
688	  standard PC machines.
689
690config X86_32_IRIS
691	tristate "Eurobraille/Iris poweroff module"
692	depends on X86_32
693	---help---
694	  The Iris machines from EuroBraille do not have APM or ACPI support
695	  to shut themselves down properly.  A special I/O sequence is
696	  needed to do so, which is what this module does at
697	  kernel shutdown.
698
699	  This is only for Iris machines from EuroBraille.
700
701	  If unused, say N.
702
703config SCHED_OMIT_FRAME_POINTER
704	def_bool y
705	prompt "Single-depth WCHAN output"
706	depends on X86
707	---help---
708	  Calculate simpler /proc/<PID>/wchan values. If this option
709	  is disabled then wchan values will recurse back to the
710	  caller function. This provides more accurate wchan values,
711	  at the expense of slightly more scheduling overhead.
712
713	  If in doubt, say "Y".
714
715menuconfig HYPERVISOR_GUEST
716	bool "Linux guest support"
717	---help---
718	  Say Y here to enable options for running Linux under various hyper-
719	  visors. This option enables basic hypervisor detection and platform
720	  setup.
721
722	  If you say N, all options in this submenu will be skipped and
723	  disabled, and Linux guest support won't be built in.
724
725if HYPERVISOR_GUEST
726
727config PARAVIRT
728	bool "Enable paravirtualization code"
729	---help---
730	  This changes the kernel so it can modify itself when it is run
731	  under a hypervisor, potentially improving performance significantly
732	  over full virtualization.  However, when run without a hypervisor
733	  the kernel is theoretically slower and slightly larger.
734
735config PARAVIRT_DEBUG
736	bool "paravirt-ops debugging"
737	depends on PARAVIRT && DEBUG_KERNEL
738	---help---
739	  Enable to debug paravirt_ops internals.  Specifically, BUG if
740	  a paravirt_op is missing when it is called.
741
742config PARAVIRT_SPINLOCKS
743	bool "Paravirtualization layer for spinlocks"
744	depends on PARAVIRT && SMP
745	---help---
746	  Paravirtualized spinlocks allow a pvops backend to replace the
747	  spinlock implementation with something virtualization-friendly
748	  (for example, block the virtual CPU rather than spinning).
749
750	  It has a minimal impact on native kernels and gives a nice performance
751	  benefit on paravirtualized KVM / Xen kernels.
752
753	  If you are unsure how to answer this question, answer Y.
754
755config QUEUED_LOCK_STAT
756	bool "Paravirt queued spinlock statistics"
757	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
758	---help---
759	  Enable the collection of statistical data on the slowpath
760	  behavior of paravirtualized queued spinlocks and report
761	  them on debugfs.
762
763source "arch/x86/xen/Kconfig"
764
765config KVM_GUEST
766	bool "KVM Guest support (including kvmclock)"
767	depends on PARAVIRT
768	select PARAVIRT_CLOCK
769	default y
770	---help---
771	  This option enables various optimizations for running under the KVM
772	  hypervisor. It includes a paravirtualized clock, so that instead
773	  of relying on a PIT (or probably other) emulation by the
774	  underlying device model, the host provides the guest with
775	  timing infrastructure such as time of day, and system time
776
777config KVM_DEBUG_FS
778	bool "Enable debug information for KVM Guests in debugfs"
779	depends on KVM_GUEST && DEBUG_FS
780	default n
781	---help---
782	  This option enables collection of various statistics for KVM guest.
783	  Statistics are displayed in debugfs filesystem. Enabling this option
784	  may incur significant overhead.
785
786config PARAVIRT_TIME_ACCOUNTING
787	bool "Paravirtual steal time accounting"
788	depends on PARAVIRT
789	default n
790	---help---
791	  Select this option to enable fine granularity task steal time
792	  accounting. Time spent executing other tasks in parallel with
793	  the current vCPU is discounted from the vCPU power. To account for
794	  that, there can be a small performance impact.
795
796	  If in doubt, say N here.
797
798config PARAVIRT_CLOCK
799	bool
800
801endif #HYPERVISOR_GUEST
802
803config NO_BOOTMEM
804	def_bool y
805
806source "arch/x86/Kconfig.cpu"
807
808config HPET_TIMER
809	def_bool X86_64
810	prompt "HPET Timer Support" if X86_32
811	---help---
812	  Use the IA-PC HPET (High Precision Event Timer) to manage
813	  time in preference to the PIT and RTC, if a HPET is
814	  present.
815	  HPET is the next generation timer replacing legacy 8254s.
816	  The HPET provides a stable time base on SMP
817	  systems, unlike the TSC, but it is more expensive to access,
818	  as it is off-chip.  The interface used is documented
819	  in the HPET spec, revision 1.
820
821	  You can safely choose Y here.  However, HPET will only be
822	  activated if the platform and the BIOS support this feature.
823	  Otherwise the 8254 will be used for timing services.
824
825	  Choose N to continue using the legacy 8254 timer.
826
827config HPET_EMULATE_RTC
828	def_bool y
829	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
830
831config APB_TIMER
832       def_bool y if X86_INTEL_MID
833       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
834       select DW_APB_TIMER
835       depends on X86_INTEL_MID && SFI
836       help
837         APB timer is the replacement for 8254, HPET on X86 MID platforms.
838         The APBT provides a stable time base on SMP
839         systems, unlike the TSC, but it is more expensive to access,
840         as it is off-chip. APB timers are always running regardless of CPU
841         C states, they are used as per CPU clockevent device when possible.
842
843# Mark as expert because too many people got it wrong.
844# The code disables itself when not needed.
845config DMI
846	default y
847	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
848	bool "Enable DMI scanning" if EXPERT
849	---help---
850	  Enabled scanning of DMI to identify machine quirks. Say Y
851	  here unless you have verified that your setup is not
852	  affected by entries in the DMI blacklist. Required by PNP
853	  BIOS code.
854
855config GART_IOMMU
856	bool "Old AMD GART IOMMU support"
857	select SWIOTLB
858	depends on X86_64 && PCI && AMD_NB
859	---help---
860	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
861	  GART based hardware IOMMUs.
862
863	  The GART supports full DMA access for devices with 32-bit access
864	  limitations, on systems with more than 3 GB. This is usually needed
865	  for USB, sound, many IDE/SATA chipsets and some other devices.
866
867	  Newer systems typically have a modern AMD IOMMU, supported via
868	  the CONFIG_AMD_IOMMU=y config option.
869
870	  In normal configurations this driver is only active when needed:
871	  there's more than 3 GB of memory and the system contains a
872	  32-bit limited device.
873
874	  If unsure, say Y.
875
876config CALGARY_IOMMU
877	bool "IBM Calgary IOMMU support"
878	select SWIOTLB
879	depends on X86_64 && PCI
880	---help---
881	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
882	  systems. Needed to run systems with more than 3GB of memory
883	  properly with 32-bit PCI devices that do not support DAC
884	  (Double Address Cycle). Calgary also supports bus level
885	  isolation, where all DMAs pass through the IOMMU.  This
886	  prevents them from going anywhere except their intended
887	  destination. This catches hard-to-find kernel bugs and
888	  mis-behaving drivers and devices that do not use the DMA-API
889	  properly to set up their DMA buffers.  The IOMMU can be
890	  turned off at boot time with the iommu=off parameter.
891	  Normally the kernel will make the right choice by itself.
892	  If unsure, say Y.
893
894config CALGARY_IOMMU_ENABLED_BY_DEFAULT
895	def_bool y
896	prompt "Should Calgary be enabled by default?"
897	depends on CALGARY_IOMMU
898	---help---
899	  Should Calgary be enabled by default? if you choose 'y', Calgary
900	  will be used (if it exists). If you choose 'n', Calgary will not be
901	  used even if it exists. If you choose 'n' and would like to use
902	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
903	  If unsure, say Y.
904
905# need this always selected by IOMMU for the VIA workaround
906config SWIOTLB
907	def_bool y if X86_64
908	---help---
909	  Support for software bounce buffers used on x86-64 systems
910	  which don't have a hardware IOMMU. Using this PCI devices
911	  which can only access 32-bits of memory can be used on systems
912	  with more than 3 GB of memory.
913	  If unsure, say Y.
914
915config IOMMU_HELPER
916	def_bool y
917	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
918
919config MAXSMP
920	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
921	depends on X86_64 && SMP && DEBUG_KERNEL
922	select CPUMASK_OFFSTACK
923	---help---
924	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
925	  If unsure, say N.
926
927config NR_CPUS
928	int "Maximum number of CPUs" if SMP && !MAXSMP
929	range 2 8 if SMP && X86_32 && !X86_BIGSMP
930	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
931	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
932	default "1" if !SMP
933	default "8192" if MAXSMP
934	default "32" if SMP && X86_BIGSMP
935	default "8" if SMP && X86_32
936	default "64" if SMP
937	---help---
938	  This allows you to specify the maximum number of CPUs which this
939	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
940	  supported value is 8192, otherwise the maximum value is 512.  The
941	  minimum value which makes sense is 2.
942
943	  This is purely to save memory - each supported CPU adds
944	  approximately eight kilobytes to the kernel image.
945
946config SCHED_SMT
947	bool "SMT (Hyperthreading) scheduler support"
948	depends on SMP
949	---help---
950	  SMT scheduler support improves the CPU scheduler's decision making
951	  when dealing with Intel Pentium 4 chips with HyperThreading at a
952	  cost of slightly increased overhead in some places. If unsure say
953	  N here.
954
955config SCHED_MC
956	def_bool y
957	prompt "Multi-core scheduler support"
958	depends on SMP
959	---help---
960	  Multi-core scheduler support improves the CPU scheduler's decision
961	  making when dealing with multi-core CPU chips at a cost of slightly
962	  increased overhead in some places. If unsure say N here.
963
964config SCHED_MC_PRIO
965	bool "CPU core priorities scheduler support"
966	depends on SCHED_MC && CPU_SUP_INTEL
967	select X86_INTEL_PSTATE
968	select CPU_FREQ
969	default y
970	---help---
971	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
972	  core ordering determined at manufacturing time, which allows
973	  certain cores to reach higher turbo frequencies (when running
974	  single threaded workloads) than others.
975
976	  Enabling this kernel feature teaches the scheduler about
977	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
978	  scheduler's CPU selection logic accordingly, so that higher
979	  overall system performance can be achieved.
980
981	  This feature will have no effect on CPUs without this feature.
982
983	  If unsure say Y here.
984
985source "kernel/Kconfig.preempt"
986
987config UP_LATE_INIT
988       def_bool y
989       depends on !SMP && X86_LOCAL_APIC
990
991config X86_UP_APIC
992	bool "Local APIC support on uniprocessors" if !PCI_MSI
993	default PCI_MSI
994	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
995	---help---
996	  A local APIC (Advanced Programmable Interrupt Controller) is an
997	  integrated interrupt controller in the CPU. If you have a single-CPU
998	  system which has a processor with a local APIC, you can say Y here to
999	  enable and use it. If you say Y here even though your machine doesn't
1000	  have a local APIC, then the kernel will still run with no slowdown at
1001	  all. The local APIC supports CPU-generated self-interrupts (timer,
1002	  performance counters), and the NMI watchdog which detects hard
1003	  lockups.
1004
1005config X86_UP_IOAPIC
1006	bool "IO-APIC support on uniprocessors"
1007	depends on X86_UP_APIC
1008	---help---
1009	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1010	  SMP-capable replacement for PC-style interrupt controllers. Most
1011	  SMP systems and many recent uniprocessor systems have one.
1012
1013	  If you have a single-CPU system with an IO-APIC, you can say Y here
1014	  to use it. If you say Y here even though your machine doesn't have
1015	  an IO-APIC, then the kernel will still run with no slowdown at all.
1016
1017config X86_LOCAL_APIC
1018	def_bool y
1019	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1020	select IRQ_DOMAIN_HIERARCHY
1021	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1022
1023config X86_IO_APIC
1024	def_bool y
1025	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1026
1027config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1028	bool "Reroute for broken boot IRQs"
1029	depends on X86_IO_APIC
1030	---help---
1031	  This option enables a workaround that fixes a source of
1032	  spurious interrupts. This is recommended when threaded
1033	  interrupt handling is used on systems where the generation of
1034	  superfluous "boot interrupts" cannot be disabled.
1035
1036	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1037	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1038	  kernel does during interrupt handling). On chipsets where this
1039	  boot IRQ generation cannot be disabled, this workaround keeps
1040	  the original IRQ line masked so that only the equivalent "boot
1041	  IRQ" is delivered to the CPUs. The workaround also tells the
1042	  kernel to set up the IRQ handler on the boot IRQ line. In this
1043	  way only one interrupt is delivered to the kernel. Otherwise
1044	  the spurious second interrupt may cause the kernel to bring
1045	  down (vital) interrupt lines.
1046
1047	  Only affects "broken" chipsets. Interrupt sharing may be
1048	  increased on these systems.
1049
1050config X86_MCE
1051	bool "Machine Check / overheating reporting"
1052	select GENERIC_ALLOCATOR
1053	default y
1054	---help---
1055	  Machine Check support allows the processor to notify the
1056	  kernel if it detects a problem (e.g. overheating, data corruption).
1057	  The action the kernel takes depends on the severity of the problem,
1058	  ranging from warning messages to halting the machine.
1059
1060config X86_MCELOG_LEGACY
1061	bool "Support for deprecated /dev/mcelog character device"
1062	depends on X86_MCE
1063	---help---
1064	  Enable support for /dev/mcelog which is needed by the old mcelog
1065	  userspace logging daemon. Consider switching to the new generation
1066	  rasdaemon solution.
1067
1068config X86_MCE_INTEL
1069	def_bool y
1070	prompt "Intel MCE features"
1071	depends on X86_MCE && X86_LOCAL_APIC
1072	---help---
1073	   Additional support for intel specific MCE features such as
1074	   the thermal monitor.
1075
1076config X86_MCE_AMD
1077	def_bool y
1078	prompt "AMD MCE features"
1079	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1080	---help---
1081	   Additional support for AMD specific MCE features such as
1082	   the DRAM Error Threshold.
1083
1084config X86_ANCIENT_MCE
1085	bool "Support for old Pentium 5 / WinChip machine checks"
1086	depends on X86_32 && X86_MCE
1087	---help---
1088	  Include support for machine check handling on old Pentium 5 or WinChip
1089	  systems. These typically need to be enabled explicitly on the command
1090	  line.
1091
1092config X86_MCE_THRESHOLD
1093	depends on X86_MCE_AMD || X86_MCE_INTEL
1094	def_bool y
1095
1096config X86_MCE_INJECT
1097	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1098	tristate "Machine check injector support"
1099	---help---
1100	  Provide support for injecting machine checks for testing purposes.
1101	  If you don't know what a machine check is and you don't do kernel
1102	  QA it is safe to say n.
1103
1104config X86_THERMAL_VECTOR
1105	def_bool y
1106	depends on X86_MCE_INTEL
1107
1108source "arch/x86/events/Kconfig"
1109
1110config X86_LEGACY_VM86
1111	bool "Legacy VM86 support"
1112	default n
1113	depends on X86_32
1114	---help---
1115	  This option allows user programs to put the CPU into V8086
1116	  mode, which is an 80286-era approximation of 16-bit real mode.
1117
1118	  Some very old versions of X and/or vbetool require this option
1119	  for user mode setting.  Similarly, DOSEMU will use it if
1120	  available to accelerate real mode DOS programs.  However, any
1121	  recent version of DOSEMU, X, or vbetool should be fully
1122	  functional even without kernel VM86 support, as they will all
1123	  fall back to software emulation. Nevertheless, if you are using
1124	  a 16-bit DOS program where 16-bit performance matters, vm86
1125	  mode might be faster than emulation and you might want to
1126	  enable this option.
1127
1128	  Note that any app that works on a 64-bit kernel is unlikely to
1129	  need this option, as 64-bit kernels don't, and can't, support
1130	  V8086 mode. This option is also unrelated to 16-bit protected
1131	  mode and is not needed to run most 16-bit programs under Wine.
1132
1133	  Enabling this option increases the complexity of the kernel
1134	  and slows down exception handling a tiny bit.
1135
1136	  If unsure, say N here.
1137
1138config VM86
1139       bool
1140       default X86_LEGACY_VM86
1141
1142config X86_16BIT
1143	bool "Enable support for 16-bit segments" if EXPERT
1144	default y
1145	depends on MODIFY_LDT_SYSCALL
1146	---help---
1147	  This option is required by programs like Wine to run 16-bit
1148	  protected mode legacy code on x86 processors.  Disabling
1149	  this option saves about 300 bytes on i386, or around 6K text
1150	  plus 16K runtime memory on x86-64,
1151
1152config X86_ESPFIX32
1153	def_bool y
1154	depends on X86_16BIT && X86_32
1155
1156config X86_ESPFIX64
1157	def_bool y
1158	depends on X86_16BIT && X86_64
1159
1160config X86_VSYSCALL_EMULATION
1161       bool "Enable vsyscall emulation" if EXPERT
1162       default y
1163       depends on X86_64
1164       ---help---
1165	 This enables emulation of the legacy vsyscall page.  Disabling
1166	 it is roughly equivalent to booting with vsyscall=none, except
1167	 that it will also disable the helpful warning if a program
1168	 tries to use a vsyscall.  With this option set to N, offending
1169	 programs will just segfault, citing addresses of the form
1170	 0xffffffffff600?00.
1171
1172	 This option is required by many programs built before 2013, and
1173	 care should be used even with newer programs if set to N.
1174
1175	 Disabling this option saves about 7K of kernel size and
1176	 possibly 4K of additional runtime pagetable memory.
1177
1178config TOSHIBA
1179	tristate "Toshiba Laptop support"
1180	depends on X86_32
1181	---help---
1182	  This adds a driver to safely access the System Management Mode of
1183	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1184	  not work on models with a Phoenix BIOS. The System Management Mode
1185	  is used to set the BIOS and power saving options on Toshiba portables.
1186
1187	  For information on utilities to make use of this driver see the
1188	  Toshiba Linux utilities web site at:
1189	  <http://www.buzzard.org.uk/toshiba/>.
1190
1191	  Say Y if you intend to run this kernel on a Toshiba portable.
1192	  Say N otherwise.
1193
1194config I8K
1195	tristate "Dell i8k legacy laptop support"
1196	select HWMON
1197	select SENSORS_DELL_SMM
1198	---help---
1199	  This option enables legacy /proc/i8k userspace interface in hwmon
1200	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1201	  temperature and allows controlling fan speeds of Dell laptops via
1202	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1203	  it reports also power and hotkey status. For fan speed control is
1204	  needed userspace package i8kutils.
1205
1206	  Say Y if you intend to run this kernel on old Dell laptops or want to
1207	  use userspace package i8kutils.
1208	  Say N otherwise.
1209
1210config X86_REBOOTFIXUPS
1211	bool "Enable X86 board specific fixups for reboot"
1212	depends on X86_32
1213	---help---
1214	  This enables chipset and/or board specific fixups to be done
1215	  in order to get reboot to work correctly. This is only needed on
1216	  some combinations of hardware and BIOS. The symptom, for which
1217	  this config is intended, is when reboot ends with a stalled/hung
1218	  system.
1219
1220	  Currently, the only fixup is for the Geode machines using
1221	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1222
1223	  Say Y if you want to enable the fixup. Currently, it's safe to
1224	  enable this option even if you don't need it.
1225	  Say N otherwise.
1226
1227config MICROCODE
1228	bool "CPU microcode loading support"
1229	default y
1230	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1231	select FW_LOADER
1232	---help---
1233	  If you say Y here, you will be able to update the microcode on
1234	  Intel and AMD processors. The Intel support is for the IA32 family,
1235	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1236	  AMD support is for families 0x10 and later. You will obviously need
1237	  the actual microcode binary data itself which is not shipped with
1238	  the Linux kernel.
1239
1240	  The preferred method to load microcode from a detached initrd is described
1241	  in Documentation/x86/early-microcode.txt. For that you need to enable
1242	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1243	  initrd for microcode blobs.
1244
1245	  In addition, you can build-in the microcode into the kernel. For that you
1246	  need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1247	  to the CONFIG_EXTRA_FIRMWARE config option.
1248
1249config MICROCODE_INTEL
1250	bool "Intel microcode loading support"
1251	depends on MICROCODE
1252	default MICROCODE
1253	select FW_LOADER
1254	---help---
1255	  This options enables microcode patch loading support for Intel
1256	  processors.
1257
1258	  For the current Intel microcode data package go to
1259	  <https://downloadcenter.intel.com> and search for
1260	  'Linux Processor Microcode Data File'.
1261
1262config MICROCODE_AMD
1263	bool "AMD microcode loading support"
1264	depends on MICROCODE
1265	select FW_LOADER
1266	---help---
1267	  If you select this option, microcode patch loading support for AMD
1268	  processors will be enabled.
1269
1270config MICROCODE_OLD_INTERFACE
1271	def_bool y
1272	depends on MICROCODE
1273
1274config X86_MSR
1275	tristate "/dev/cpu/*/msr - Model-specific register support"
1276	---help---
1277	  This device gives privileged processes access to the x86
1278	  Model-Specific Registers (MSRs).  It is a character device with
1279	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1280	  MSR accesses are directed to a specific CPU on multi-processor
1281	  systems.
1282
1283config X86_CPUID
1284	tristate "/dev/cpu/*/cpuid - CPU information support"
1285	---help---
1286	  This device gives processes access to the x86 CPUID instruction to
1287	  be executed on a specific processor.  It is a character device
1288	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1289	  /dev/cpu/31/cpuid.
1290
1291choice
1292	prompt "High Memory Support"
1293	default HIGHMEM4G
1294	depends on X86_32
1295
1296config NOHIGHMEM
1297	bool "off"
1298	---help---
1299	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1300	  However, the address space of 32-bit x86 processors is only 4
1301	  Gigabytes large. That means that, if you have a large amount of
1302	  physical memory, not all of it can be "permanently mapped" by the
1303	  kernel. The physical memory that's not permanently mapped is called
1304	  "high memory".
1305
1306	  If you are compiling a kernel which will never run on a machine with
1307	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1308	  choice and suitable for most users). This will result in a "3GB/1GB"
1309	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1310	  space and the remaining part of the 4GB virtual memory space is used
1311	  by the kernel to permanently map as much physical memory as
1312	  possible.
1313
1314	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1315	  answer "4GB" here.
1316
1317	  If more than 4 Gigabytes is used then answer "64GB" here. This
1318	  selection turns Intel PAE (Physical Address Extension) mode on.
1319	  PAE implements 3-level paging on IA32 processors. PAE is fully
1320	  supported by Linux, PAE mode is implemented on all recent Intel
1321	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1322	  then the kernel will not boot on CPUs that don't support PAE!
1323
1324	  The actual amount of total physical memory will either be
1325	  auto detected or can be forced by using a kernel command line option
1326	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1327	  your boot loader (lilo or loadlin) about how to pass options to the
1328	  kernel at boot time.)
1329
1330	  If unsure, say "off".
1331
1332config HIGHMEM4G
1333	bool "4GB"
1334	---help---
1335	  Select this if you have a 32-bit processor and between 1 and 4
1336	  gigabytes of physical RAM.
1337
1338config HIGHMEM64G
1339	bool "64GB"
1340	depends on !M486
1341	select X86_PAE
1342	---help---
1343	  Select this if you have a 32-bit processor and more than 4
1344	  gigabytes of physical RAM.
1345
1346endchoice
1347
1348choice
1349	prompt "Memory split" if EXPERT
1350	default VMSPLIT_3G
1351	depends on X86_32
1352	---help---
1353	  Select the desired split between kernel and user memory.
1354
1355	  If the address range available to the kernel is less than the
1356	  physical memory installed, the remaining memory will be available
1357	  as "high memory". Accessing high memory is a little more costly
1358	  than low memory, as it needs to be mapped into the kernel first.
1359	  Note that increasing the kernel address space limits the range
1360	  available to user programs, making the address space there
1361	  tighter.  Selecting anything other than the default 3G/1G split
1362	  will also likely make your kernel incompatible with binary-only
1363	  kernel modules.
1364
1365	  If you are not absolutely sure what you are doing, leave this
1366	  option alone!
1367
1368	config VMSPLIT_3G
1369		bool "3G/1G user/kernel split"
1370	config VMSPLIT_3G_OPT
1371		depends on !X86_PAE
1372		bool "3G/1G user/kernel split (for full 1G low memory)"
1373	config VMSPLIT_2G
1374		bool "2G/2G user/kernel split"
1375	config VMSPLIT_2G_OPT
1376		depends on !X86_PAE
1377		bool "2G/2G user/kernel split (for full 2G low memory)"
1378	config VMSPLIT_1G
1379		bool "1G/3G user/kernel split"
1380endchoice
1381
1382config PAGE_OFFSET
1383	hex
1384	default 0xB0000000 if VMSPLIT_3G_OPT
1385	default 0x80000000 if VMSPLIT_2G
1386	default 0x78000000 if VMSPLIT_2G_OPT
1387	default 0x40000000 if VMSPLIT_1G
1388	default 0xC0000000
1389	depends on X86_32
1390
1391config HIGHMEM
1392	def_bool y
1393	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1394
1395config X86_PAE
1396	bool "PAE (Physical Address Extension) Support"
1397	depends on X86_32 && !HIGHMEM4G
1398	select SWIOTLB
1399	---help---
1400	  PAE is required for NX support, and furthermore enables
1401	  larger swapspace support for non-overcommit purposes. It
1402	  has the cost of more pagetable lookup overhead, and also
1403	  consumes more pagetable space per process.
1404
1405config X86_5LEVEL
1406	bool "Enable 5-level page tables support"
1407	depends on X86_64
1408	---help---
1409	  5-level paging enables access to larger address space:
1410	  upto 128 PiB of virtual address space and 4 PiB of
1411	  physical address space.
1412
1413	  It will be supported by future Intel CPUs.
1414
1415	  Note: a kernel with this option enabled can only be booted
1416	  on machines that support the feature.
1417
1418	  See Documentation/x86/x86_64/5level-paging.txt for more
1419	  information.
1420
1421	  Say N if unsure.
1422
1423config ARCH_PHYS_ADDR_T_64BIT
1424	def_bool y
1425	depends on X86_64 || X86_PAE
1426
1427config ARCH_DMA_ADDR_T_64BIT
1428	def_bool y
1429	depends on X86_64 || HIGHMEM64G
1430
1431config X86_DIRECT_GBPAGES
1432	def_bool y
1433	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1434	---help---
1435	  Certain kernel features effectively disable kernel
1436	  linear 1 GB mappings (even if the CPU otherwise
1437	  supports them), so don't confuse the user by printing
1438	  that we have them enabled.
1439
1440config ARCH_HAS_MEM_ENCRYPT
1441	def_bool y
1442
1443config AMD_MEM_ENCRYPT
1444	bool "AMD Secure Memory Encryption (SME) support"
1445	depends on X86_64 && CPU_SUP_AMD
1446	---help---
1447	  Say yes to enable support for the encryption of system memory.
1448	  This requires an AMD processor that supports Secure Memory
1449	  Encryption (SME).
1450
1451config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1452	bool "Activate AMD Secure Memory Encryption (SME) by default"
1453	default y
1454	depends on AMD_MEM_ENCRYPT
1455	---help---
1456	  Say yes to have system memory encrypted by default if running on
1457	  an AMD processor that supports Secure Memory Encryption (SME).
1458
1459	  If set to Y, then the encryption of system memory can be
1460	  deactivated with the mem_encrypt=off command line option.
1461
1462	  If set to N, then the encryption of system memory can be
1463	  activated with the mem_encrypt=on command line option.
1464
1465config ARCH_USE_MEMREMAP_PROT
1466	def_bool y
1467	depends on AMD_MEM_ENCRYPT
1468
1469# Common NUMA Features
1470config NUMA
1471	bool "Numa Memory Allocation and Scheduler Support"
1472	depends on SMP
1473	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1474	default y if X86_BIGSMP
1475	---help---
1476	  Enable NUMA (Non Uniform Memory Access) support.
1477
1478	  The kernel will try to allocate memory used by a CPU on the
1479	  local memory controller of the CPU and add some more
1480	  NUMA awareness to the kernel.
1481
1482	  For 64-bit this is recommended if the system is Intel Core i7
1483	  (or later), AMD Opteron, or EM64T NUMA.
1484
1485	  For 32-bit this is only needed if you boot a 32-bit
1486	  kernel on a 64-bit NUMA platform.
1487
1488	  Otherwise, you should say N.
1489
1490config AMD_NUMA
1491	def_bool y
1492	prompt "Old style AMD Opteron NUMA detection"
1493	depends on X86_64 && NUMA && PCI
1494	---help---
1495	  Enable AMD NUMA node topology detection.  You should say Y here if
1496	  you have a multi processor AMD system. This uses an old method to
1497	  read the NUMA configuration directly from the builtin Northbridge
1498	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1499	  which also takes priority if both are compiled in.
1500
1501config X86_64_ACPI_NUMA
1502	def_bool y
1503	prompt "ACPI NUMA detection"
1504	depends on X86_64 && NUMA && ACPI && PCI
1505	select ACPI_NUMA
1506	---help---
1507	  Enable ACPI SRAT based node topology detection.
1508
1509# Some NUMA nodes have memory ranges that span
1510# other nodes.  Even though a pfn is valid and
1511# between a node's start and end pfns, it may not
1512# reside on that node.  See memmap_init_zone()
1513# for details.
1514config NODES_SPAN_OTHER_NODES
1515	def_bool y
1516	depends on X86_64_ACPI_NUMA
1517
1518config NUMA_EMU
1519	bool "NUMA emulation"
1520	depends on NUMA
1521	---help---
1522	  Enable NUMA emulation. A flat machine will be split
1523	  into virtual nodes when booted with "numa=fake=N", where N is the
1524	  number of nodes. This is only useful for debugging.
1525
1526config NODES_SHIFT
1527	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1528	range 1 10
1529	default "10" if MAXSMP
1530	default "6" if X86_64
1531	default "3"
1532	depends on NEED_MULTIPLE_NODES
1533	---help---
1534	  Specify the maximum number of NUMA Nodes available on the target
1535	  system.  Increases memory reserved to accommodate various tables.
1536
1537config ARCH_HAVE_MEMORY_PRESENT
1538	def_bool y
1539	depends on X86_32 && DISCONTIGMEM
1540
1541config NEED_NODE_MEMMAP_SIZE
1542	def_bool y
1543	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1544
1545config ARCH_FLATMEM_ENABLE
1546	def_bool y
1547	depends on X86_32 && !NUMA
1548
1549config ARCH_DISCONTIGMEM_ENABLE
1550	def_bool y
1551	depends on NUMA && X86_32
1552
1553config ARCH_DISCONTIGMEM_DEFAULT
1554	def_bool y
1555	depends on NUMA && X86_32
1556
1557config ARCH_SPARSEMEM_ENABLE
1558	def_bool y
1559	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1560	select SPARSEMEM_STATIC if X86_32
1561	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1562
1563config ARCH_SPARSEMEM_DEFAULT
1564	def_bool y
1565	depends on X86_64
1566
1567config ARCH_SELECT_MEMORY_MODEL
1568	def_bool y
1569	depends on ARCH_SPARSEMEM_ENABLE
1570
1571config ARCH_MEMORY_PROBE
1572	bool "Enable sysfs memory/probe interface"
1573	depends on X86_64 && MEMORY_HOTPLUG
1574	help
1575	  This option enables a sysfs memory/probe interface for testing.
1576	  See Documentation/memory-hotplug.txt for more information.
1577	  If you are unsure how to answer this question, answer N.
1578
1579config ARCH_PROC_KCORE_TEXT
1580	def_bool y
1581	depends on X86_64 && PROC_KCORE
1582
1583config ILLEGAL_POINTER_VALUE
1584       hex
1585       default 0 if X86_32
1586       default 0xdead000000000000 if X86_64
1587
1588source "mm/Kconfig"
1589
1590config X86_PMEM_LEGACY_DEVICE
1591	bool
1592
1593config X86_PMEM_LEGACY
1594	tristate "Support non-standard NVDIMMs and ADR protected memory"
1595	depends on PHYS_ADDR_T_64BIT
1596	depends on BLK_DEV
1597	select X86_PMEM_LEGACY_DEVICE
1598	select LIBNVDIMM
1599	help
1600	  Treat memory marked using the non-standard e820 type of 12 as used
1601	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1602	  The kernel will offer these regions to the 'pmem' driver so
1603	  they can be used for persistent storage.
1604
1605	  Say Y if unsure.
1606
1607config HIGHPTE
1608	bool "Allocate 3rd-level pagetables from highmem"
1609	depends on HIGHMEM
1610	---help---
1611	  The VM uses one page table entry for each page of physical memory.
1612	  For systems with a lot of RAM, this can be wasteful of precious
1613	  low memory.  Setting this option will put user-space page table
1614	  entries in high memory.
1615
1616config X86_CHECK_BIOS_CORRUPTION
1617	bool "Check for low memory corruption"
1618	---help---
1619	  Periodically check for memory corruption in low memory, which
1620	  is suspected to be caused by BIOS.  Even when enabled in the
1621	  configuration, it is disabled at runtime.  Enable it by
1622	  setting "memory_corruption_check=1" on the kernel command
1623	  line.  By default it scans the low 64k of memory every 60
1624	  seconds; see the memory_corruption_check_size and
1625	  memory_corruption_check_period parameters in
1626	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1627
1628	  When enabled with the default parameters, this option has
1629	  almost no overhead, as it reserves a relatively small amount
1630	  of memory and scans it infrequently.  It both detects corruption
1631	  and prevents it from affecting the running system.
1632
1633	  It is, however, intended as a diagnostic tool; if repeatable
1634	  BIOS-originated corruption always affects the same memory,
1635	  you can use memmap= to prevent the kernel from using that
1636	  memory.
1637
1638config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1639	bool "Set the default setting of memory_corruption_check"
1640	depends on X86_CHECK_BIOS_CORRUPTION
1641	default y
1642	---help---
1643	  Set whether the default state of memory_corruption_check is
1644	  on or off.
1645
1646config X86_RESERVE_LOW
1647	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1648	default 64
1649	range 4 640
1650	---help---
1651	  Specify the amount of low memory to reserve for the BIOS.
1652
1653	  The first page contains BIOS data structures that the kernel
1654	  must not use, so that page must always be reserved.
1655
1656	  By default we reserve the first 64K of physical RAM, as a
1657	  number of BIOSes are known to corrupt that memory range
1658	  during events such as suspend/resume or monitor cable
1659	  insertion, so it must not be used by the kernel.
1660
1661	  You can set this to 4 if you are absolutely sure that you
1662	  trust the BIOS to get all its memory reservations and usages
1663	  right.  If you know your BIOS have problems beyond the
1664	  default 64K area, you can set this to 640 to avoid using the
1665	  entire low memory range.
1666
1667	  If you have doubts about the BIOS (e.g. suspend/resume does
1668	  not work or there's kernel crashes after certain hardware
1669	  hotplug events) then you might want to enable
1670	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1671	  typical corruption patterns.
1672
1673	  Leave this to the default value of 64 if you are unsure.
1674
1675config MATH_EMULATION
1676	bool
1677	depends on MODIFY_LDT_SYSCALL
1678	prompt "Math emulation" if X86_32
1679	---help---
1680	  Linux can emulate a math coprocessor (used for floating point
1681	  operations) if you don't have one. 486DX and Pentium processors have
1682	  a math coprocessor built in, 486SX and 386 do not, unless you added
1683	  a 487DX or 387, respectively. (The messages during boot time can
1684	  give you some hints here ["man dmesg"].) Everyone needs either a
1685	  coprocessor or this emulation.
1686
1687	  If you don't have a math coprocessor, you need to say Y here; if you
1688	  say Y here even though you have a coprocessor, the coprocessor will
1689	  be used nevertheless. (This behavior can be changed with the kernel
1690	  command line option "no387", which comes handy if your coprocessor
1691	  is broken. Try "man bootparam" or see the documentation of your boot
1692	  loader (lilo or loadlin) about how to pass options to the kernel at
1693	  boot time.) This means that it is a good idea to say Y here if you
1694	  intend to use this kernel on different machines.
1695
1696	  More information about the internals of the Linux math coprocessor
1697	  emulation can be found in <file:arch/x86/math-emu/README>.
1698
1699	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1700	  kernel, it won't hurt.
1701
1702config MTRR
1703	def_bool y
1704	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1705	---help---
1706	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1707	  the Memory Type Range Registers (MTRRs) may be used to control
1708	  processor access to memory ranges. This is most useful if you have
1709	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1710	  allows bus write transfers to be combined into a larger transfer
1711	  before bursting over the PCI/AGP bus. This can increase performance
1712	  of image write operations 2.5 times or more. Saying Y here creates a
1713	  /proc/mtrr file which may be used to manipulate your processor's
1714	  MTRRs. Typically the X server should use this.
1715
1716	  This code has a reasonably generic interface so that similar
1717	  control registers on other processors can be easily supported
1718	  as well:
1719
1720	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1721	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1722	  these, the ARRs are used to emulate the MTRRs.
1723	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1724	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1725	  write-combining. All of these processors are supported by this code
1726	  and it makes sense to say Y here if you have one of them.
1727
1728	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1729	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1730	  can lead to all sorts of problems, so it's good to say Y here.
1731
1732	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1733	  just add about 9 KB to your kernel.
1734
1735	  See <file:Documentation/x86/mtrr.txt> for more information.
1736
1737config MTRR_SANITIZER
1738	def_bool y
1739	prompt "MTRR cleanup support"
1740	depends on MTRR
1741	---help---
1742	  Convert MTRR layout from continuous to discrete, so X drivers can
1743	  add writeback entries.
1744
1745	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1746	  The largest mtrr entry size for a continuous block can be set with
1747	  mtrr_chunk_size.
1748
1749	  If unsure, say Y.
1750
1751config MTRR_SANITIZER_ENABLE_DEFAULT
1752	int "MTRR cleanup enable value (0-1)"
1753	range 0 1
1754	default "0"
1755	depends on MTRR_SANITIZER
1756	---help---
1757	  Enable mtrr cleanup default value
1758
1759config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1760	int "MTRR cleanup spare reg num (0-7)"
1761	range 0 7
1762	default "1"
1763	depends on MTRR_SANITIZER
1764	---help---
1765	  mtrr cleanup spare entries default, it can be changed via
1766	  mtrr_spare_reg_nr=N on the kernel command line.
1767
1768config X86_PAT
1769	def_bool y
1770	prompt "x86 PAT support" if EXPERT
1771	depends on MTRR
1772	---help---
1773	  Use PAT attributes to setup page level cache control.
1774
1775	  PATs are the modern equivalents of MTRRs and are much more
1776	  flexible than MTRRs.
1777
1778	  Say N here if you see bootup problems (boot crash, boot hang,
1779	  spontaneous reboots) or a non-working video driver.
1780
1781	  If unsure, say Y.
1782
1783config ARCH_USES_PG_UNCACHED
1784	def_bool y
1785	depends on X86_PAT
1786
1787config ARCH_RANDOM
1788	def_bool y
1789	prompt "x86 architectural random number generator" if EXPERT
1790	---help---
1791	  Enable the x86 architectural RDRAND instruction
1792	  (Intel Bull Mountain technology) to generate random numbers.
1793	  If supported, this is a high bandwidth, cryptographically
1794	  secure hardware random number generator.
1795
1796config X86_SMAP
1797	def_bool y
1798	prompt "Supervisor Mode Access Prevention" if EXPERT
1799	---help---
1800	  Supervisor Mode Access Prevention (SMAP) is a security
1801	  feature in newer Intel processors.  There is a small
1802	  performance cost if this enabled and turned on; there is
1803	  also a small increase in the kernel size if this is enabled.
1804
1805	  If unsure, say Y.
1806
1807config X86_INTEL_UMIP
1808	def_bool n
1809	depends on CPU_SUP_INTEL
1810	prompt "Intel User Mode Instruction Prevention" if EXPERT
1811	---help---
1812	  The User Mode Instruction Prevention (UMIP) is a security
1813	  feature in newer Intel processors. If enabled, a general
1814	  protection fault is issued if the instructions SGDT, SLDT,
1815	  SIDT, SMSW and STR are executed in user mode.
1816
1817config X86_INTEL_MPX
1818	prompt "Intel MPX (Memory Protection Extensions)"
1819	def_bool n
1820	# Note: only available in 64-bit mode due to VMA flags shortage
1821	depends on CPU_SUP_INTEL && X86_64
1822	select ARCH_USES_HIGH_VMA_FLAGS
1823	---help---
1824	  MPX provides hardware features that can be used in
1825	  conjunction with compiler-instrumented code to check
1826	  memory references.  It is designed to detect buffer
1827	  overflow or underflow bugs.
1828
1829	  This option enables running applications which are
1830	  instrumented or otherwise use MPX.  It does not use MPX
1831	  itself inside the kernel or to protect the kernel
1832	  against bad memory references.
1833
1834	  Enabling this option will make the kernel larger:
1835	  ~8k of kernel text and 36 bytes of data on a 64-bit
1836	  defconfig.  It adds a long to the 'mm_struct' which
1837	  will increase the kernel memory overhead of each
1838	  process and adds some branches to paths used during
1839	  exec() and munmap().
1840
1841	  For details, see Documentation/x86/intel_mpx.txt
1842
1843	  If unsure, say N.
1844
1845config X86_INTEL_MEMORY_PROTECTION_KEYS
1846	prompt "Intel Memory Protection Keys"
1847	def_bool y
1848	# Note: only available in 64-bit mode
1849	depends on CPU_SUP_INTEL && X86_64
1850	select ARCH_USES_HIGH_VMA_FLAGS
1851	select ARCH_HAS_PKEYS
1852	---help---
1853	  Memory Protection Keys provides a mechanism for enforcing
1854	  page-based protections, but without requiring modification of the
1855	  page tables when an application changes protection domains.
1856
1857	  For details, see Documentation/x86/protection-keys.txt
1858
1859	  If unsure, say y.
1860
1861config EFI
1862	bool "EFI runtime service support"
1863	depends on ACPI
1864	select UCS2_STRING
1865	select EFI_RUNTIME_WRAPPERS
1866	---help---
1867	  This enables the kernel to use EFI runtime services that are
1868	  available (such as the EFI variable services).
1869
1870	  This option is only useful on systems that have EFI firmware.
1871	  In addition, you should use the latest ELILO loader available
1872	  at <http://elilo.sourceforge.net> in order to take advantage
1873	  of EFI runtime services. However, even with this option, the
1874	  resultant kernel should continue to boot on existing non-EFI
1875	  platforms.
1876
1877config EFI_STUB
1878       bool "EFI stub support"
1879       depends on EFI && !X86_USE_3DNOW
1880       select RELOCATABLE
1881       ---help---
1882          This kernel feature allows a bzImage to be loaded directly
1883	  by EFI firmware without the use of a bootloader.
1884
1885	  See Documentation/efi-stub.txt for more information.
1886
1887config EFI_MIXED
1888	bool "EFI mixed-mode support"
1889	depends on EFI_STUB && X86_64
1890	---help---
1891	   Enabling this feature allows a 64-bit kernel to be booted
1892	   on a 32-bit firmware, provided that your CPU supports 64-bit
1893	   mode.
1894
1895	   Note that it is not possible to boot a mixed-mode enabled
1896	   kernel via the EFI boot stub - a bootloader that supports
1897	   the EFI handover protocol must be used.
1898
1899	   If unsure, say N.
1900
1901config SECCOMP
1902	def_bool y
1903	prompt "Enable seccomp to safely compute untrusted bytecode"
1904	---help---
1905	  This kernel feature is useful for number crunching applications
1906	  that may need to compute untrusted bytecode during their
1907	  execution. By using pipes or other transports made available to
1908	  the process as file descriptors supporting the read/write
1909	  syscalls, it's possible to isolate those applications in
1910	  their own address space using seccomp. Once seccomp is
1911	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1912	  and the task is only allowed to execute a few safe syscalls
1913	  defined by each seccomp mode.
1914
1915	  If unsure, say Y. Only embedded should say N here.
1916
1917source kernel/Kconfig.hz
1918
1919config KEXEC
1920	bool "kexec system call"
1921	select KEXEC_CORE
1922	---help---
1923	  kexec is a system call that implements the ability to shutdown your
1924	  current kernel, and to start another kernel.  It is like a reboot
1925	  but it is independent of the system firmware.   And like a reboot
1926	  you can start any kernel with it, not just Linux.
1927
1928	  The name comes from the similarity to the exec system call.
1929
1930	  It is an ongoing process to be certain the hardware in a machine
1931	  is properly shutdown, so do not be surprised if this code does not
1932	  initially work for you.  As of this writing the exact hardware
1933	  interface is strongly in flux, so no good recommendation can be
1934	  made.
1935
1936config KEXEC_FILE
1937	bool "kexec file based system call"
1938	select KEXEC_CORE
1939	select BUILD_BIN2C
1940	depends on X86_64
1941	depends on CRYPTO=y
1942	depends on CRYPTO_SHA256=y
1943	---help---
1944	  This is new version of kexec system call. This system call is
1945	  file based and takes file descriptors as system call argument
1946	  for kernel and initramfs as opposed to list of segments as
1947	  accepted by previous system call.
1948
1949config KEXEC_VERIFY_SIG
1950	bool "Verify kernel signature during kexec_file_load() syscall"
1951	depends on KEXEC_FILE
1952	---help---
1953	  This option makes kernel signature verification mandatory for
1954	  the kexec_file_load() syscall.
1955
1956	  In addition to that option, you need to enable signature
1957	  verification for the corresponding kernel image type being
1958	  loaded in order for this to work.
1959
1960config KEXEC_BZIMAGE_VERIFY_SIG
1961	bool "Enable bzImage signature verification support"
1962	depends on KEXEC_VERIFY_SIG
1963	depends on SIGNED_PE_FILE_VERIFICATION
1964	select SYSTEM_TRUSTED_KEYRING
1965	---help---
1966	  Enable bzImage signature verification support.
1967
1968config CRASH_DUMP
1969	bool "kernel crash dumps"
1970	depends on X86_64 || (X86_32 && HIGHMEM)
1971	---help---
1972	  Generate crash dump after being started by kexec.
1973	  This should be normally only set in special crash dump kernels
1974	  which are loaded in the main kernel with kexec-tools into
1975	  a specially reserved region and then later executed after
1976	  a crash by kdump/kexec. The crash dump kernel must be compiled
1977	  to a memory address not used by the main kernel or BIOS using
1978	  PHYSICAL_START, or it must be built as a relocatable image
1979	  (CONFIG_RELOCATABLE=y).
1980	  For more details see Documentation/kdump/kdump.txt
1981
1982config KEXEC_JUMP
1983	bool "kexec jump"
1984	depends on KEXEC && HIBERNATION
1985	---help---
1986	  Jump between original kernel and kexeced kernel and invoke
1987	  code in physical address mode via KEXEC
1988
1989config PHYSICAL_START
1990	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1991	default "0x1000000"
1992	---help---
1993	  This gives the physical address where the kernel is loaded.
1994
1995	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1996	  bzImage will decompress itself to above physical address and
1997	  run from there. Otherwise, bzImage will run from the address where
1998	  it has been loaded by the boot loader and will ignore above physical
1999	  address.
2000
2001	  In normal kdump cases one does not have to set/change this option
2002	  as now bzImage can be compiled as a completely relocatable image
2003	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2004	  address. This option is mainly useful for the folks who don't want
2005	  to use a bzImage for capturing the crash dump and want to use a
2006	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2007	  to be specifically compiled to run from a specific memory area
2008	  (normally a reserved region) and this option comes handy.
2009
2010	  So if you are using bzImage for capturing the crash dump,
2011	  leave the value here unchanged to 0x1000000 and set
2012	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2013	  for capturing the crash dump change this value to start of
2014	  the reserved region.  In other words, it can be set based on
2015	  the "X" value as specified in the "crashkernel=YM@XM"
2016	  command line boot parameter passed to the panic-ed
2017	  kernel. Please take a look at Documentation/kdump/kdump.txt
2018	  for more details about crash dumps.
2019
2020	  Usage of bzImage for capturing the crash dump is recommended as
2021	  one does not have to build two kernels. Same kernel can be used
2022	  as production kernel and capture kernel. Above option should have
2023	  gone away after relocatable bzImage support is introduced. But it
2024	  is present because there are users out there who continue to use
2025	  vmlinux for dump capture. This option should go away down the
2026	  line.
2027
2028	  Don't change this unless you know what you are doing.
2029
2030config RELOCATABLE
2031	bool "Build a relocatable kernel"
2032	default y
2033	---help---
2034	  This builds a kernel image that retains relocation information
2035	  so it can be loaded someplace besides the default 1MB.
2036	  The relocations tend to make the kernel binary about 10% larger,
2037	  but are discarded at runtime.
2038
2039	  One use is for the kexec on panic case where the recovery kernel
2040	  must live at a different physical address than the primary
2041	  kernel.
2042
2043	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2044	  it has been loaded at and the compile time physical address
2045	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2046
2047config RANDOMIZE_BASE
2048	bool "Randomize the address of the kernel image (KASLR)"
2049	depends on RELOCATABLE
2050	default y
2051	---help---
2052	  In support of Kernel Address Space Layout Randomization (KASLR),
2053	  this randomizes the physical address at which the kernel image
2054	  is decompressed and the virtual address where the kernel
2055	  image is mapped, as a security feature that deters exploit
2056	  attempts relying on knowledge of the location of kernel
2057	  code internals.
2058
2059	  On 64-bit, the kernel physical and virtual addresses are
2060	  randomized separately. The physical address will be anywhere
2061	  between 16MB and the top of physical memory (up to 64TB). The
2062	  virtual address will be randomized from 16MB up to 1GB (9 bits
2063	  of entropy). Note that this also reduces the memory space
2064	  available to kernel modules from 1.5GB to 1GB.
2065
2066	  On 32-bit, the kernel physical and virtual addresses are
2067	  randomized together. They will be randomized from 16MB up to
2068	  512MB (8 bits of entropy).
2069
2070	  Entropy is generated using the RDRAND instruction if it is
2071	  supported. If RDTSC is supported, its value is mixed into
2072	  the entropy pool as well. If neither RDRAND nor RDTSC are
2073	  supported, then entropy is read from the i8254 timer. The
2074	  usable entropy is limited by the kernel being built using
2075	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2076	  minimum of 2MB. As a result, only 10 bits of entropy are
2077	  theoretically possible, but the implementations are further
2078	  limited due to memory layouts.
2079
2080	  If unsure, say Y.
2081
2082# Relocation on x86 needs some additional build support
2083config X86_NEED_RELOCS
2084	def_bool y
2085	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2086
2087config PHYSICAL_ALIGN
2088	hex "Alignment value to which kernel should be aligned"
2089	default "0x200000"
2090	range 0x2000 0x1000000 if X86_32
2091	range 0x200000 0x1000000 if X86_64
2092	---help---
2093	  This value puts the alignment restrictions on physical address
2094	  where kernel is loaded and run from. Kernel is compiled for an
2095	  address which meets above alignment restriction.
2096
2097	  If bootloader loads the kernel at a non-aligned address and
2098	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2099	  address aligned to above value and run from there.
2100
2101	  If bootloader loads the kernel at a non-aligned address and
2102	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2103	  load address and decompress itself to the address it has been
2104	  compiled for and run from there. The address for which kernel is
2105	  compiled already meets above alignment restrictions. Hence the
2106	  end result is that kernel runs from a physical address meeting
2107	  above alignment restrictions.
2108
2109	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2110	  this value must be a multiple of 0x200000.
2111
2112	  Don't change this unless you know what you are doing.
2113
2114config RANDOMIZE_MEMORY
2115	bool "Randomize the kernel memory sections"
2116	depends on X86_64
2117	depends on RANDOMIZE_BASE
2118	default RANDOMIZE_BASE
2119	---help---
2120	   Randomizes the base virtual address of kernel memory sections
2121	   (physical memory mapping, vmalloc & vmemmap). This security feature
2122	   makes exploits relying on predictable memory locations less reliable.
2123
2124	   The order of allocations remains unchanged. Entropy is generated in
2125	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2126	   configuration have in average 30,000 different possible virtual
2127	   addresses for each memory section.
2128
2129	   If unsure, say Y.
2130
2131config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2132	hex "Physical memory mapping padding" if EXPERT
2133	depends on RANDOMIZE_MEMORY
2134	default "0xa" if MEMORY_HOTPLUG
2135	default "0x0"
2136	range 0x1 0x40 if MEMORY_HOTPLUG
2137	range 0x0 0x40
2138	---help---
2139	   Define the padding in terabytes added to the existing physical
2140	   memory size during kernel memory randomization. It is useful
2141	   for memory hotplug support but reduces the entropy available for
2142	   address randomization.
2143
2144	   If unsure, leave at the default value.
2145
2146config HOTPLUG_CPU
2147	bool "Support for hot-pluggable CPUs"
2148	depends on SMP
2149	---help---
2150	  Say Y here to allow turning CPUs off and on. CPUs can be
2151	  controlled through /sys/devices/system/cpu.
2152	  ( Note: power management support will enable this option
2153	    automatically on SMP systems. )
2154	  Say N if you want to disable CPU hotplug.
2155
2156config BOOTPARAM_HOTPLUG_CPU0
2157	bool "Set default setting of cpu0_hotpluggable"
2158	default n
2159	depends on HOTPLUG_CPU
2160	---help---
2161	  Set whether default state of cpu0_hotpluggable is on or off.
2162
2163	  Say Y here to enable CPU0 hotplug by default. If this switch
2164	  is turned on, there is no need to give cpu0_hotplug kernel
2165	  parameter and the CPU0 hotplug feature is enabled by default.
2166
2167	  Please note: there are two known CPU0 dependencies if you want
2168	  to enable the CPU0 hotplug feature either by this switch or by
2169	  cpu0_hotplug kernel parameter.
2170
2171	  First, resume from hibernate or suspend always starts from CPU0.
2172	  So hibernate and suspend are prevented if CPU0 is offline.
2173
2174	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2175	  offline if any interrupt can not migrate out of CPU0. There may
2176	  be other CPU0 dependencies.
2177
2178	  Please make sure the dependencies are under your control before
2179	  you enable this feature.
2180
2181	  Say N if you don't want to enable CPU0 hotplug feature by default.
2182	  You still can enable the CPU0 hotplug feature at boot by kernel
2183	  parameter cpu0_hotplug.
2184
2185config DEBUG_HOTPLUG_CPU0
2186	def_bool n
2187	prompt "Debug CPU0 hotplug"
2188	depends on HOTPLUG_CPU
2189	---help---
2190	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2191	  soon as possible and boots up userspace with CPU0 offlined. User
2192	  can online CPU0 back after boot time.
2193
2194	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2195	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2196	  compilation or giving cpu0_hotplug kernel parameter at boot.
2197
2198	  If unsure, say N.
2199
2200config COMPAT_VDSO
2201	def_bool n
2202	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2203	depends on COMPAT_32
2204	---help---
2205	  Certain buggy versions of glibc will crash if they are
2206	  presented with a 32-bit vDSO that is not mapped at the address
2207	  indicated in its segment table.
2208
2209	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2210	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2211	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2212	  the only released version with the bug, but OpenSUSE 9
2213	  contains a buggy "glibc 2.3.2".
2214
2215	  The symptom of the bug is that everything crashes on startup, saying:
2216	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2217
2218	  Saying Y here changes the default value of the vdso32 boot
2219	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2220	  This works around the glibc bug but hurts performance.
2221
2222	  If unsure, say N: if you are compiling your own kernel, you
2223	  are unlikely to be using a buggy version of glibc.
2224
2225choice
2226	prompt "vsyscall table for legacy applications"
2227	depends on X86_64
2228	default LEGACY_VSYSCALL_EMULATE
2229	help
2230	  Legacy user code that does not know how to find the vDSO expects
2231	  to be able to issue three syscalls by calling fixed addresses in
2232	  kernel space. Since this location is not randomized with ASLR,
2233	  it can be used to assist security vulnerability exploitation.
2234
2235	  This setting can be changed at boot time via the kernel command
2236	  line parameter vsyscall=[native|emulate|none].
2237
2238	  On a system with recent enough glibc (2.14 or newer) and no
2239	  static binaries, you can say None without a performance penalty
2240	  to improve security.
2241
2242	  If unsure, select "Emulate".
2243
2244	config LEGACY_VSYSCALL_NATIVE
2245		bool "Native"
2246		help
2247		  Actual executable code is located in the fixed vsyscall
2248		  address mapping, implementing time() efficiently. Since
2249		  this makes the mapping executable, it can be used during
2250		  security vulnerability exploitation (traditionally as
2251		  ROP gadgets). This configuration is not recommended.
2252
2253	config LEGACY_VSYSCALL_EMULATE
2254		bool "Emulate"
2255		help
2256		  The kernel traps and emulates calls into the fixed
2257		  vsyscall address mapping. This makes the mapping
2258		  non-executable, but it still contains known contents,
2259		  which could be used in certain rare security vulnerability
2260		  exploits. This configuration is recommended when userspace
2261		  still uses the vsyscall area.
2262
2263	config LEGACY_VSYSCALL_NONE
2264		bool "None"
2265		help
2266		  There will be no vsyscall mapping at all. This will
2267		  eliminate any risk of ASLR bypass due to the vsyscall
2268		  fixed address mapping. Attempts to use the vsyscalls
2269		  will be reported to dmesg, so that either old or
2270		  malicious userspace programs can be identified.
2271
2272endchoice
2273
2274config CMDLINE_BOOL
2275	bool "Built-in kernel command line"
2276	---help---
2277	  Allow for specifying boot arguments to the kernel at
2278	  build time.  On some systems (e.g. embedded ones), it is
2279	  necessary or convenient to provide some or all of the
2280	  kernel boot arguments with the kernel itself (that is,
2281	  to not rely on the boot loader to provide them.)
2282
2283	  To compile command line arguments into the kernel,
2284	  set this option to 'Y', then fill in the
2285	  boot arguments in CONFIG_CMDLINE.
2286
2287	  Systems with fully functional boot loaders (i.e. non-embedded)
2288	  should leave this option set to 'N'.
2289
2290config CMDLINE
2291	string "Built-in kernel command string"
2292	depends on CMDLINE_BOOL
2293	default ""
2294	---help---
2295	  Enter arguments here that should be compiled into the kernel
2296	  image and used at boot time.  If the boot loader provides a
2297	  command line at boot time, it is appended to this string to
2298	  form the full kernel command line, when the system boots.
2299
2300	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2301	  change this behavior.
2302
2303	  In most cases, the command line (whether built-in or provided
2304	  by the boot loader) should specify the device for the root
2305	  file system.
2306
2307config CMDLINE_OVERRIDE
2308	bool "Built-in command line overrides boot loader arguments"
2309	depends on CMDLINE_BOOL
2310	---help---
2311	  Set this option to 'Y' to have the kernel ignore the boot loader
2312	  command line, and use ONLY the built-in command line.
2313
2314	  This is used to work around broken boot loaders.  This should
2315	  be set to 'N' under normal conditions.
2316
2317config MODIFY_LDT_SYSCALL
2318	bool "Enable the LDT (local descriptor table)" if EXPERT
2319	default y
2320	---help---
2321	  Linux can allow user programs to install a per-process x86
2322	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2323	  call.  This is required to run 16-bit or segmented code such as
2324	  DOSEMU or some Wine programs.  It is also used by some very old
2325	  threading libraries.
2326
2327	  Enabling this feature adds a small amount of overhead to
2328	  context switches and increases the low-level kernel attack
2329	  surface.  Disabling it removes the modify_ldt(2) system call.
2330
2331	  Saying 'N' here may make sense for embedded or server kernels.
2332
2333source "kernel/livepatch/Kconfig"
2334
2335endmenu
2336
2337config ARCH_HAS_ADD_PAGES
2338	def_bool y
2339	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2340
2341config ARCH_ENABLE_MEMORY_HOTPLUG
2342	def_bool y
2343	depends on X86_64 || (X86_32 && HIGHMEM)
2344
2345config ARCH_ENABLE_MEMORY_HOTREMOVE
2346	def_bool y
2347	depends on MEMORY_HOTPLUG
2348
2349config USE_PERCPU_NUMA_NODE_ID
2350	def_bool y
2351	depends on NUMA
2352
2353config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2354	def_bool y
2355	depends on X86_64 || X86_PAE
2356
2357config ARCH_ENABLE_HUGEPAGE_MIGRATION
2358	def_bool y
2359	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2360
2361config ARCH_ENABLE_THP_MIGRATION
2362	def_bool y
2363	depends on X86_64 && TRANSPARENT_HUGEPAGE
2364
2365menu "Power management and ACPI options"
2366
2367config ARCH_HIBERNATION_HEADER
2368	def_bool y
2369	depends on X86_64 && HIBERNATION
2370
2371source "kernel/power/Kconfig"
2372
2373source "drivers/acpi/Kconfig"
2374
2375source "drivers/sfi/Kconfig"
2376
2377config X86_APM_BOOT
2378	def_bool y
2379	depends on APM
2380
2381menuconfig APM
2382	tristate "APM (Advanced Power Management) BIOS support"
2383	depends on X86_32 && PM_SLEEP
2384	---help---
2385	  APM is a BIOS specification for saving power using several different
2386	  techniques. This is mostly useful for battery powered laptops with
2387	  APM compliant BIOSes. If you say Y here, the system time will be
2388	  reset after a RESUME operation, the /proc/apm device will provide
2389	  battery status information, and user-space programs will receive
2390	  notification of APM "events" (e.g. battery status change).
2391
2392	  If you select "Y" here, you can disable actual use of the APM
2393	  BIOS by passing the "apm=off" option to the kernel at boot time.
2394
2395	  Note that the APM support is almost completely disabled for
2396	  machines with more than one CPU.
2397
2398	  In order to use APM, you will need supporting software. For location
2399	  and more information, read <file:Documentation/power/apm-acpi.txt>
2400	  and the Battery Powered Linux mini-HOWTO, available from
2401	  <http://www.tldp.org/docs.html#howto>.
2402
2403	  This driver does not spin down disk drives (see the hdparm(8)
2404	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2405	  VESA-compliant "green" monitors.
2406
2407	  This driver does not support the TI 4000M TravelMate and the ACER
2408	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2409	  desktop machines also don't have compliant BIOSes, and this driver
2410	  may cause those machines to panic during the boot phase.
2411
2412	  Generally, if you don't have a battery in your machine, there isn't
2413	  much point in using this driver and you should say N. If you get
2414	  random kernel OOPSes or reboots that don't seem to be related to
2415	  anything, try disabling/enabling this option (or disabling/enabling
2416	  APM in your BIOS).
2417
2418	  Some other things you should try when experiencing seemingly random,
2419	  "weird" problems:
2420
2421	  1) make sure that you have enough swap space and that it is
2422	  enabled.
2423	  2) pass the "no-hlt" option to the kernel
2424	  3) switch on floating point emulation in the kernel and pass
2425	  the "no387" option to the kernel
2426	  4) pass the "floppy=nodma" option to the kernel
2427	  5) pass the "mem=4M" option to the kernel (thereby disabling
2428	  all but the first 4 MB of RAM)
2429	  6) make sure that the CPU is not over clocked.
2430	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2431	  8) disable the cache from your BIOS settings
2432	  9) install a fan for the video card or exchange video RAM
2433	  10) install a better fan for the CPU
2434	  11) exchange RAM chips
2435	  12) exchange the motherboard.
2436
2437	  To compile this driver as a module, choose M here: the
2438	  module will be called apm.
2439
2440if APM
2441
2442config APM_IGNORE_USER_SUSPEND
2443	bool "Ignore USER SUSPEND"
2444	---help---
2445	  This option will ignore USER SUSPEND requests. On machines with a
2446	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2447	  series notebooks, it is necessary to say Y because of a BIOS bug.
2448
2449config APM_DO_ENABLE
2450	bool "Enable PM at boot time"
2451	---help---
2452	  Enable APM features at boot time. From page 36 of the APM BIOS
2453	  specification: "When disabled, the APM BIOS does not automatically
2454	  power manage devices, enter the Standby State, enter the Suspend
2455	  State, or take power saving steps in response to CPU Idle calls."
2456	  This driver will make CPU Idle calls when Linux is idle (unless this
2457	  feature is turned off -- see "Do CPU IDLE calls", below). This
2458	  should always save battery power, but more complicated APM features
2459	  will be dependent on your BIOS implementation. You may need to turn
2460	  this option off if your computer hangs at boot time when using APM
2461	  support, or if it beeps continuously instead of suspending. Turn
2462	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2463	  T400CDT. This is off by default since most machines do fine without
2464	  this feature.
2465
2466config APM_CPU_IDLE
2467	depends on CPU_IDLE
2468	bool "Make CPU Idle calls when idle"
2469	---help---
2470	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2471	  On some machines, this can activate improved power savings, such as
2472	  a slowed CPU clock rate, when the machine is idle. These idle calls
2473	  are made after the idle loop has run for some length of time (e.g.,
2474	  333 mS). On some machines, this will cause a hang at boot time or
2475	  whenever the CPU becomes idle. (On machines with more than one CPU,
2476	  this option does nothing.)
2477
2478config APM_DISPLAY_BLANK
2479	bool "Enable console blanking using APM"
2480	---help---
2481	  Enable console blanking using the APM. Some laptops can use this to
2482	  turn off the LCD backlight when the screen blanker of the Linux
2483	  virtual console blanks the screen. Note that this is only used by
2484	  the virtual console screen blanker, and won't turn off the backlight
2485	  when using the X Window system. This also doesn't have anything to
2486	  do with your VESA-compliant power-saving monitor. Further, this
2487	  option doesn't work for all laptops -- it might not turn off your
2488	  backlight at all, or it might print a lot of errors to the console,
2489	  especially if you are using gpm.
2490
2491config APM_ALLOW_INTS
2492	bool "Allow interrupts during APM BIOS calls"
2493	---help---
2494	  Normally we disable external interrupts while we are making calls to
2495	  the APM BIOS as a measure to lessen the effects of a badly behaving
2496	  BIOS implementation.  The BIOS should reenable interrupts if it
2497	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2498	  many of the newer IBM Thinkpads.  If you experience hangs when you
2499	  suspend, try setting this to Y.  Otherwise, say N.
2500
2501endif # APM
2502
2503source "drivers/cpufreq/Kconfig"
2504
2505source "drivers/cpuidle/Kconfig"
2506
2507source "drivers/idle/Kconfig"
2508
2509endmenu
2510
2511
2512menu "Bus options (PCI etc.)"
2513
2514config PCI
2515	bool "PCI support"
2516	default y
2517	---help---
2518	  Find out whether you have a PCI motherboard. PCI is the name of a
2519	  bus system, i.e. the way the CPU talks to the other stuff inside
2520	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2521	  VESA. If you have PCI, say Y, otherwise N.
2522
2523choice
2524	prompt "PCI access mode"
2525	depends on X86_32 && PCI
2526	default PCI_GOANY
2527	---help---
2528	  On PCI systems, the BIOS can be used to detect the PCI devices and
2529	  determine their configuration. However, some old PCI motherboards
2530	  have BIOS bugs and may crash if this is done. Also, some embedded
2531	  PCI-based systems don't have any BIOS at all. Linux can also try to
2532	  detect the PCI hardware directly without using the BIOS.
2533
2534	  With this option, you can specify how Linux should detect the
2535	  PCI devices. If you choose "BIOS", the BIOS will be used,
2536	  if you choose "Direct", the BIOS won't be used, and if you
2537	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2538	  If you choose "Any", the kernel will try MMCONFIG, then the
2539	  direct access method and falls back to the BIOS if that doesn't
2540	  work. If unsure, go with the default, which is "Any".
2541
2542config PCI_GOBIOS
2543	bool "BIOS"
2544
2545config PCI_GOMMCONFIG
2546	bool "MMConfig"
2547
2548config PCI_GODIRECT
2549	bool "Direct"
2550
2551config PCI_GOOLPC
2552	bool "OLPC XO-1"
2553	depends on OLPC
2554
2555config PCI_GOANY
2556	bool "Any"
2557
2558endchoice
2559
2560config PCI_BIOS
2561	def_bool y
2562	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2563
2564# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2565config PCI_DIRECT
2566	def_bool y
2567	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2568
2569config PCI_MMCONFIG
2570	def_bool y
2571	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2572
2573config PCI_OLPC
2574	def_bool y
2575	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2576
2577config PCI_XEN
2578	def_bool y
2579	depends on PCI && XEN
2580	select SWIOTLB_XEN
2581
2582config PCI_DOMAINS
2583	def_bool y
2584	depends on PCI
2585
2586config PCI_MMCONFIG
2587	bool "Support mmconfig PCI config space access"
2588	depends on X86_64 && PCI && ACPI
2589
2590config PCI_CNB20LE_QUIRK
2591	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2592	depends on PCI
2593	help
2594	  Read the PCI windows out of the CNB20LE host bridge. This allows
2595	  PCI hotplug to work on systems with the CNB20LE chipset which do
2596	  not have ACPI.
2597
2598	  There's no public spec for this chipset, and this functionality
2599	  is known to be incomplete.
2600
2601	  You should say N unless you know you need this.
2602
2603source "drivers/pci/Kconfig"
2604
2605config ISA_BUS
2606	bool "ISA-style bus support on modern systems" if EXPERT
2607	select ISA_BUS_API
2608	help
2609	  Enables ISA-style drivers on modern systems. This is necessary to
2610	  support PC/104 devices on X86_64 platforms.
2611
2612	  If unsure, say N.
2613
2614# x86_64 have no ISA slots, but can have ISA-style DMA.
2615config ISA_DMA_API
2616	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2617	default y
2618	help
2619	  Enables ISA-style DMA support for devices requiring such controllers.
2620	  If unsure, say Y.
2621
2622if X86_32
2623
2624config ISA
2625	bool "ISA support"
2626	---help---
2627	  Find out whether you have ISA slots on your motherboard.  ISA is the
2628	  name of a bus system, i.e. the way the CPU talks to the other stuff
2629	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2630	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2631	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2632
2633config EISA
2634	bool "EISA support"
2635	depends on ISA
2636	---help---
2637	  The Extended Industry Standard Architecture (EISA) bus was
2638	  developed as an open alternative to the IBM MicroChannel bus.
2639
2640	  The EISA bus provided some of the features of the IBM MicroChannel
2641	  bus while maintaining backward compatibility with cards made for
2642	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2643	  1995 when it was made obsolete by the PCI bus.
2644
2645	  Say Y here if you are building a kernel for an EISA-based machine.
2646
2647	  Otherwise, say N.
2648
2649source "drivers/eisa/Kconfig"
2650
2651config SCx200
2652	tristate "NatSemi SCx200 support"
2653	---help---
2654	  This provides basic support for National Semiconductor's
2655	  (now AMD's) Geode processors.  The driver probes for the
2656	  PCI-IDs of several on-chip devices, so its a good dependency
2657	  for other scx200_* drivers.
2658
2659	  If compiled as a module, the driver is named scx200.
2660
2661config SCx200HR_TIMER
2662	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2663	depends on SCx200
2664	default y
2665	---help---
2666	  This driver provides a clocksource built upon the on-chip
2667	  27MHz high-resolution timer.  Its also a workaround for
2668	  NSC Geode SC-1100's buggy TSC, which loses time when the
2669	  processor goes idle (as is done by the scheduler).  The
2670	  other workaround is idle=poll boot option.
2671
2672config OLPC
2673	bool "One Laptop Per Child support"
2674	depends on !X86_PAE
2675	select GPIOLIB
2676	select OF
2677	select OF_PROMTREE
2678	select IRQ_DOMAIN
2679	---help---
2680	  Add support for detecting the unique features of the OLPC
2681	  XO hardware.
2682
2683config OLPC_XO1_PM
2684	bool "OLPC XO-1 Power Management"
2685	depends on OLPC && MFD_CS5535 && PM_SLEEP
2686	select MFD_CORE
2687	---help---
2688	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2689
2690config OLPC_XO1_RTC
2691	bool "OLPC XO-1 Real Time Clock"
2692	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2693	---help---
2694	  Add support for the XO-1 real time clock, which can be used as a
2695	  programmable wakeup source.
2696
2697config OLPC_XO1_SCI
2698	bool "OLPC XO-1 SCI extras"
2699	depends on OLPC && OLPC_XO1_PM
2700	depends on INPUT=y
2701	select POWER_SUPPLY
2702	select GPIO_CS5535
2703	select MFD_CORE
2704	---help---
2705	  Add support for SCI-based features of the OLPC XO-1 laptop:
2706	   - EC-driven system wakeups
2707	   - Power button
2708	   - Ebook switch
2709	   - Lid switch
2710	   - AC adapter status updates
2711	   - Battery status updates
2712
2713config OLPC_XO15_SCI
2714	bool "OLPC XO-1.5 SCI extras"
2715	depends on OLPC && ACPI
2716	select POWER_SUPPLY
2717	---help---
2718	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2719	   - EC-driven system wakeups
2720	   - AC adapter status updates
2721	   - Battery status updates
2722
2723config ALIX
2724	bool "PCEngines ALIX System Support (LED setup)"
2725	select GPIOLIB
2726	---help---
2727	  This option enables system support for the PCEngines ALIX.
2728	  At present this just sets up LEDs for GPIO control on
2729	  ALIX2/3/6 boards.  However, other system specific setup should
2730	  get added here.
2731
2732	  Note: You must still enable the drivers for GPIO and LED support
2733	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2734
2735	  Note: You have to set alix.force=1 for boards with Award BIOS.
2736
2737config NET5501
2738	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2739	select GPIOLIB
2740	---help---
2741	  This option enables system support for the Soekris Engineering net5501.
2742
2743config GEOS
2744	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2745	select GPIOLIB
2746	depends on DMI
2747	---help---
2748	  This option enables system support for the Traverse Technologies GEOS.
2749
2750config TS5500
2751	bool "Technologic Systems TS-5500 platform support"
2752	depends on MELAN
2753	select CHECK_SIGNATURE
2754	select NEW_LEDS
2755	select LEDS_CLASS
2756	---help---
2757	  This option enables system support for the Technologic Systems TS-5500.
2758
2759endif # X86_32
2760
2761config AMD_NB
2762	def_bool y
2763	depends on CPU_SUP_AMD && PCI
2764
2765source "drivers/pcmcia/Kconfig"
2766
2767config RAPIDIO
2768	tristate "RapidIO support"
2769	depends on PCI
2770	default n
2771	help
2772	  If enabled this option will include drivers and the core
2773	  infrastructure code to support RapidIO interconnect devices.
2774
2775source "drivers/rapidio/Kconfig"
2776
2777config X86_SYSFB
2778	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2779	help
2780	  Firmwares often provide initial graphics framebuffers so the BIOS,
2781	  bootloader or kernel can show basic video-output during boot for
2782	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2783	  Extensions and EFI-framebuffers for this, which are mostly limited
2784	  to x86.
2785	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2786	  framebuffers so the new generic system-framebuffer drivers can be
2787	  used on x86. If the framebuffer is not compatible with the generic
2788	  modes, it is adverticed as fallback platform framebuffer so legacy
2789	  drivers like efifb, vesafb and uvesafb can pick it up.
2790	  If this option is not selected, all system framebuffers are always
2791	  marked as fallback platform framebuffers as usual.
2792
2793	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2794	  not be able to pick up generic system framebuffers if this option
2795	  is selected. You are highly encouraged to enable simplefb as
2796	  replacement if you select this option. simplefb can correctly deal
2797	  with generic system framebuffers. But you should still keep vesafb
2798	  and others enabled as fallback if a system framebuffer is
2799	  incompatible with simplefb.
2800
2801	  If unsure, say Y.
2802
2803endmenu
2804
2805
2806menu "Executable file formats / Emulations"
2807
2808source "fs/Kconfig.binfmt"
2809
2810config IA32_EMULATION
2811	bool "IA32 Emulation"
2812	depends on X86_64
2813	select ARCH_WANT_OLD_COMPAT_IPC
2814	select BINFMT_ELF
2815	select COMPAT_BINFMT_ELF
2816	select COMPAT_OLD_SIGACTION
2817	---help---
2818	  Include code to run legacy 32-bit programs under a
2819	  64-bit kernel. You should likely turn this on, unless you're
2820	  100% sure that you don't have any 32-bit programs left.
2821
2822config IA32_AOUT
2823	tristate "IA32 a.out support"
2824	depends on IA32_EMULATION
2825	---help---
2826	  Support old a.out binaries in the 32bit emulation.
2827
2828config X86_X32
2829	bool "x32 ABI for 64-bit mode"
2830	depends on X86_64
2831	---help---
2832	  Include code to run binaries for the x32 native 32-bit ABI
2833	  for 64-bit processors.  An x32 process gets access to the
2834	  full 64-bit register file and wide data path while leaving
2835	  pointers at 32 bits for smaller memory footprint.
2836
2837	  You will need a recent binutils (2.22 or later) with
2838	  elf32_x86_64 support enabled to compile a kernel with this
2839	  option set.
2840
2841config COMPAT_32
2842	def_bool y
2843	depends on IA32_EMULATION || X86_32
2844	select HAVE_UID16
2845	select OLD_SIGSUSPEND3
2846
2847config COMPAT
2848	def_bool y
2849	depends on IA32_EMULATION || X86_X32
2850
2851if COMPAT
2852config COMPAT_FOR_U64_ALIGNMENT
2853	def_bool y
2854
2855config SYSVIPC_COMPAT
2856	def_bool y
2857	depends on SYSVIPC
2858endif
2859
2860endmenu
2861
2862
2863config HAVE_ATOMIC_IOMAP
2864	def_bool y
2865	depends on X86_32
2866
2867config X86_DEV_DMA_OPS
2868	bool
2869	depends on X86_64 || STA2X11
2870
2871config X86_DMA_REMAP
2872	bool
2873	depends on STA2X11
2874
2875config HAVE_GENERIC_GUP
2876	def_bool y
2877
2878source "net/Kconfig"
2879
2880source "drivers/Kconfig"
2881
2882source "drivers/firmware/Kconfig"
2883
2884source "fs/Kconfig"
2885
2886source "arch/x86/Kconfig.debug"
2887
2888source "security/Kconfig"
2889
2890source "crypto/Kconfig"
2891
2892source "arch/x86/kvm/Kconfig"
2893
2894source "lib/Kconfig"
2895