xref: /openbmc/linux/arch/x86/Kconfig (revision 9dae47aba0a055f761176d9297371d5bb24289ec)
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
114	select HAVE_ARCH_KGDB
115	select HAVE_ARCH_MMAP_RND_BITS		if MMU
116	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
117	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
118	select HAVE_ARCH_SECCOMP_FILTER
119	select HAVE_ARCH_TRACEHOOK
120	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
121	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
122	select HAVE_ARCH_VMAP_STACK		if X86_64
123	select HAVE_ARCH_WITHIN_STACK_FRAMES
124	select HAVE_CC_STACKPROTECTOR
125	select HAVE_CMPXCHG_DOUBLE
126	select HAVE_CMPXCHG_LOCAL
127	select HAVE_CONTEXT_TRACKING		if X86_64
128	select HAVE_COPY_THREAD_TLS
129	select HAVE_C_RECORDMCOUNT
130	select HAVE_DEBUG_KMEMLEAK
131	select HAVE_DEBUG_STACKOVERFLOW
132	select HAVE_DMA_API_DEBUG
133	select HAVE_DMA_CONTIGUOUS
134	select HAVE_DYNAMIC_FTRACE
135	select HAVE_DYNAMIC_FTRACE_WITH_REGS
136	select HAVE_EBPF_JIT			if X86_64
137	select HAVE_EFFICIENT_UNALIGNED_ACCESS
138	select HAVE_EXIT_THREAD
139	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
140	select HAVE_FTRACE_MCOUNT_RECORD
141	select HAVE_FUNCTION_GRAPH_TRACER
142	select HAVE_FUNCTION_TRACER
143	select HAVE_GCC_PLUGINS
144	select HAVE_HW_BREAKPOINT
145	select HAVE_IDE
146	select HAVE_IOREMAP_PROT
147	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
148	select HAVE_IRQ_TIME_ACCOUNTING
149	select HAVE_KERNEL_BZIP2
150	select HAVE_KERNEL_GZIP
151	select HAVE_KERNEL_LZ4
152	select HAVE_KERNEL_LZMA
153	select HAVE_KERNEL_LZO
154	select HAVE_KERNEL_XZ
155	select HAVE_KPROBES
156	select HAVE_KPROBES_ON_FTRACE
157	select HAVE_KPROBE_OVERRIDE
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 64 if SMP && X86_32 && X86_BIGSMP
931	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
932	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
933	default "1" if !SMP
934	default "8192" if MAXSMP
935	default "32" if SMP && X86_BIGSMP
936	default "8" if SMP && X86_32
937	default "64" if SMP
938	---help---
939	  This allows you to specify the maximum number of CPUs which this
940	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
941	  supported value is 8192, otherwise the maximum value is 512.  The
942	  minimum value which makes sense is 2.
943
944	  This is purely to save memory - each supported CPU adds
945	  approximately eight kilobytes to the kernel image.
946
947config SCHED_SMT
948	bool "SMT (Hyperthreading) scheduler support"
949	depends on SMP
950	---help---
951	  SMT scheduler support improves the CPU scheduler's decision making
952	  when dealing with Intel Pentium 4 chips with HyperThreading at a
953	  cost of slightly increased overhead in some places. If unsure say
954	  N here.
955
956config SCHED_MC
957	def_bool y
958	prompt "Multi-core scheduler support"
959	depends on SMP
960	---help---
961	  Multi-core scheduler support improves the CPU scheduler's decision
962	  making when dealing with multi-core CPU chips at a cost of slightly
963	  increased overhead in some places. If unsure say N here.
964
965config SCHED_MC_PRIO
966	bool "CPU core priorities scheduler support"
967	depends on SCHED_MC && CPU_SUP_INTEL
968	select X86_INTEL_PSTATE
969	select CPU_FREQ
970	default y
971	---help---
972	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
973	  core ordering determined at manufacturing time, which allows
974	  certain cores to reach higher turbo frequencies (when running
975	  single threaded workloads) than others.
976
977	  Enabling this kernel feature teaches the scheduler about
978	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
979	  scheduler's CPU selection logic accordingly, so that higher
980	  overall system performance can be achieved.
981
982	  This feature will have no effect on CPUs without this feature.
983
984	  If unsure say Y here.
985
986source "kernel/Kconfig.preempt"
987
988config UP_LATE_INIT
989       def_bool y
990       depends on !SMP && X86_LOCAL_APIC
991
992config X86_UP_APIC
993	bool "Local APIC support on uniprocessors" if !PCI_MSI
994	default PCI_MSI
995	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
996	---help---
997	  A local APIC (Advanced Programmable Interrupt Controller) is an
998	  integrated interrupt controller in the CPU. If you have a single-CPU
999	  system which has a processor with a local APIC, you can say Y here to
1000	  enable and use it. If you say Y here even though your machine doesn't
1001	  have a local APIC, then the kernel will still run with no slowdown at
1002	  all. The local APIC supports CPU-generated self-interrupts (timer,
1003	  performance counters), and the NMI watchdog which detects hard
1004	  lockups.
1005
1006config X86_UP_IOAPIC
1007	bool "IO-APIC support on uniprocessors"
1008	depends on X86_UP_APIC
1009	---help---
1010	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1011	  SMP-capable replacement for PC-style interrupt controllers. Most
1012	  SMP systems and many recent uniprocessor systems have one.
1013
1014	  If you have a single-CPU system with an IO-APIC, you can say Y here
1015	  to use it. If you say Y here even though your machine doesn't have
1016	  an IO-APIC, then the kernel will still run with no slowdown at all.
1017
1018config X86_LOCAL_APIC
1019	def_bool y
1020	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1021	select IRQ_DOMAIN_HIERARCHY
1022	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1023
1024config X86_IO_APIC
1025	def_bool y
1026	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1027
1028config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1029	bool "Reroute for broken boot IRQs"
1030	depends on X86_IO_APIC
1031	---help---
1032	  This option enables a workaround that fixes a source of
1033	  spurious interrupts. This is recommended when threaded
1034	  interrupt handling is used on systems where the generation of
1035	  superfluous "boot interrupts" cannot be disabled.
1036
1037	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1038	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1039	  kernel does during interrupt handling). On chipsets where this
1040	  boot IRQ generation cannot be disabled, this workaround keeps
1041	  the original IRQ line masked so that only the equivalent "boot
1042	  IRQ" is delivered to the CPUs. The workaround also tells the
1043	  kernel to set up the IRQ handler on the boot IRQ line. In this
1044	  way only one interrupt is delivered to the kernel. Otherwise
1045	  the spurious second interrupt may cause the kernel to bring
1046	  down (vital) interrupt lines.
1047
1048	  Only affects "broken" chipsets. Interrupt sharing may be
1049	  increased on these systems.
1050
1051config X86_MCE
1052	bool "Machine Check / overheating reporting"
1053	select GENERIC_ALLOCATOR
1054	default y
1055	---help---
1056	  Machine Check support allows the processor to notify the
1057	  kernel if it detects a problem (e.g. overheating, data corruption).
1058	  The action the kernel takes depends on the severity of the problem,
1059	  ranging from warning messages to halting the machine.
1060
1061config X86_MCELOG_LEGACY
1062	bool "Support for deprecated /dev/mcelog character device"
1063	depends on X86_MCE
1064	---help---
1065	  Enable support for /dev/mcelog which is needed by the old mcelog
1066	  userspace logging daemon. Consider switching to the new generation
1067	  rasdaemon solution.
1068
1069config X86_MCE_INTEL
1070	def_bool y
1071	prompt "Intel MCE features"
1072	depends on X86_MCE && X86_LOCAL_APIC
1073	---help---
1074	   Additional support for intel specific MCE features such as
1075	   the thermal monitor.
1076
1077config X86_MCE_AMD
1078	def_bool y
1079	prompt "AMD MCE features"
1080	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1081	---help---
1082	   Additional support for AMD specific MCE features such as
1083	   the DRAM Error Threshold.
1084
1085config X86_ANCIENT_MCE
1086	bool "Support for old Pentium 5 / WinChip machine checks"
1087	depends on X86_32 && X86_MCE
1088	---help---
1089	  Include support for machine check handling on old Pentium 5 or WinChip
1090	  systems. These typically need to be enabled explicitly on the command
1091	  line.
1092
1093config X86_MCE_THRESHOLD
1094	depends on X86_MCE_AMD || X86_MCE_INTEL
1095	def_bool y
1096
1097config X86_MCE_INJECT
1098	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1099	tristate "Machine check injector support"
1100	---help---
1101	  Provide support for injecting machine checks for testing purposes.
1102	  If you don't know what a machine check is and you don't do kernel
1103	  QA it is safe to say n.
1104
1105config X86_THERMAL_VECTOR
1106	def_bool y
1107	depends on X86_MCE_INTEL
1108
1109source "arch/x86/events/Kconfig"
1110
1111config X86_LEGACY_VM86
1112	bool "Legacy VM86 support"
1113	default n
1114	depends on X86_32
1115	---help---
1116	  This option allows user programs to put the CPU into V8086
1117	  mode, which is an 80286-era approximation of 16-bit real mode.
1118
1119	  Some very old versions of X and/or vbetool require this option
1120	  for user mode setting.  Similarly, DOSEMU will use it if
1121	  available to accelerate real mode DOS programs.  However, any
1122	  recent version of DOSEMU, X, or vbetool should be fully
1123	  functional even without kernel VM86 support, as they will all
1124	  fall back to software emulation. Nevertheless, if you are using
1125	  a 16-bit DOS program where 16-bit performance matters, vm86
1126	  mode might be faster than emulation and you might want to
1127	  enable this option.
1128
1129	  Note that any app that works on a 64-bit kernel is unlikely to
1130	  need this option, as 64-bit kernels don't, and can't, support
1131	  V8086 mode. This option is also unrelated to 16-bit protected
1132	  mode and is not needed to run most 16-bit programs under Wine.
1133
1134	  Enabling this option increases the complexity of the kernel
1135	  and slows down exception handling a tiny bit.
1136
1137	  If unsure, say N here.
1138
1139config VM86
1140       bool
1141       default X86_LEGACY_VM86
1142
1143config X86_16BIT
1144	bool "Enable support for 16-bit segments" if EXPERT
1145	default y
1146	depends on MODIFY_LDT_SYSCALL
1147	---help---
1148	  This option is required by programs like Wine to run 16-bit
1149	  protected mode legacy code on x86 processors.  Disabling
1150	  this option saves about 300 bytes on i386, or around 6K text
1151	  plus 16K runtime memory on x86-64,
1152
1153config X86_ESPFIX32
1154	def_bool y
1155	depends on X86_16BIT && X86_32
1156
1157config X86_ESPFIX64
1158	def_bool y
1159	depends on X86_16BIT && X86_64
1160
1161config X86_VSYSCALL_EMULATION
1162       bool "Enable vsyscall emulation" if EXPERT
1163       default y
1164       depends on X86_64
1165       ---help---
1166	 This enables emulation of the legacy vsyscall page.  Disabling
1167	 it is roughly equivalent to booting with vsyscall=none, except
1168	 that it will also disable the helpful warning if a program
1169	 tries to use a vsyscall.  With this option set to N, offending
1170	 programs will just segfault, citing addresses of the form
1171	 0xffffffffff600?00.
1172
1173	 This option is required by many programs built before 2013, and
1174	 care should be used even with newer programs if set to N.
1175
1176	 Disabling this option saves about 7K of kernel size and
1177	 possibly 4K of additional runtime pagetable memory.
1178
1179config TOSHIBA
1180	tristate "Toshiba Laptop support"
1181	depends on X86_32
1182	---help---
1183	  This adds a driver to safely access the System Management Mode of
1184	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1185	  not work on models with a Phoenix BIOS. The System Management Mode
1186	  is used to set the BIOS and power saving options on Toshiba portables.
1187
1188	  For information on utilities to make use of this driver see the
1189	  Toshiba Linux utilities web site at:
1190	  <http://www.buzzard.org.uk/toshiba/>.
1191
1192	  Say Y if you intend to run this kernel on a Toshiba portable.
1193	  Say N otherwise.
1194
1195config I8K
1196	tristate "Dell i8k legacy laptop support"
1197	select HWMON
1198	select SENSORS_DELL_SMM
1199	---help---
1200	  This option enables legacy /proc/i8k userspace interface in hwmon
1201	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1202	  temperature and allows controlling fan speeds of Dell laptops via
1203	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1204	  it reports also power and hotkey status. For fan speed control is
1205	  needed userspace package i8kutils.
1206
1207	  Say Y if you intend to run this kernel on old Dell laptops or want to
1208	  use userspace package i8kutils.
1209	  Say N otherwise.
1210
1211config X86_REBOOTFIXUPS
1212	bool "Enable X86 board specific fixups for reboot"
1213	depends on X86_32
1214	---help---
1215	  This enables chipset and/or board specific fixups to be done
1216	  in order to get reboot to work correctly. This is only needed on
1217	  some combinations of hardware and BIOS. The symptom, for which
1218	  this config is intended, is when reboot ends with a stalled/hung
1219	  system.
1220
1221	  Currently, the only fixup is for the Geode machines using
1222	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1223
1224	  Say Y if you want to enable the fixup. Currently, it's safe to
1225	  enable this option even if you don't need it.
1226	  Say N otherwise.
1227
1228config MICROCODE
1229	bool "CPU microcode loading support"
1230	default y
1231	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1232	select FW_LOADER
1233	---help---
1234	  If you say Y here, you will be able to update the microcode on
1235	  Intel and AMD processors. The Intel support is for the IA32 family,
1236	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1237	  AMD support is for families 0x10 and later. You will obviously need
1238	  the actual microcode binary data itself which is not shipped with
1239	  the Linux kernel.
1240
1241	  The preferred method to load microcode from a detached initrd is described
1242	  in Documentation/x86/early-microcode.txt. For that you need to enable
1243	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1244	  initrd for microcode blobs.
1245
1246	  In addition, you can build-in the microcode into the kernel. For that you
1247	  need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1248	  to the CONFIG_EXTRA_FIRMWARE config option.
1249
1250config MICROCODE_INTEL
1251	bool "Intel microcode loading support"
1252	depends on MICROCODE
1253	default MICROCODE
1254	select FW_LOADER
1255	---help---
1256	  This options enables microcode patch loading support for Intel
1257	  processors.
1258
1259	  For the current Intel microcode data package go to
1260	  <https://downloadcenter.intel.com> and search for
1261	  'Linux Processor Microcode Data File'.
1262
1263config MICROCODE_AMD
1264	bool "AMD microcode loading support"
1265	depends on MICROCODE
1266	select FW_LOADER
1267	---help---
1268	  If you select this option, microcode patch loading support for AMD
1269	  processors will be enabled.
1270
1271config MICROCODE_OLD_INTERFACE
1272	def_bool y
1273	depends on MICROCODE
1274
1275config X86_MSR
1276	tristate "/dev/cpu/*/msr - Model-specific register support"
1277	---help---
1278	  This device gives privileged processes access to the x86
1279	  Model-Specific Registers (MSRs).  It is a character device with
1280	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1281	  MSR accesses are directed to a specific CPU on multi-processor
1282	  systems.
1283
1284config X86_CPUID
1285	tristate "/dev/cpu/*/cpuid - CPU information support"
1286	---help---
1287	  This device gives processes access to the x86 CPUID instruction to
1288	  be executed on a specific processor.  It is a character device
1289	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1290	  /dev/cpu/31/cpuid.
1291
1292choice
1293	prompt "High Memory Support"
1294	default HIGHMEM4G
1295	depends on X86_32
1296
1297config NOHIGHMEM
1298	bool "off"
1299	---help---
1300	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1301	  However, the address space of 32-bit x86 processors is only 4
1302	  Gigabytes large. That means that, if you have a large amount of
1303	  physical memory, not all of it can be "permanently mapped" by the
1304	  kernel. The physical memory that's not permanently mapped is called
1305	  "high memory".
1306
1307	  If you are compiling a kernel which will never run on a machine with
1308	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1309	  choice and suitable for most users). This will result in a "3GB/1GB"
1310	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1311	  space and the remaining part of the 4GB virtual memory space is used
1312	  by the kernel to permanently map as much physical memory as
1313	  possible.
1314
1315	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1316	  answer "4GB" here.
1317
1318	  If more than 4 Gigabytes is used then answer "64GB" here. This
1319	  selection turns Intel PAE (Physical Address Extension) mode on.
1320	  PAE implements 3-level paging on IA32 processors. PAE is fully
1321	  supported by Linux, PAE mode is implemented on all recent Intel
1322	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1323	  then the kernel will not boot on CPUs that don't support PAE!
1324
1325	  The actual amount of total physical memory will either be
1326	  auto detected or can be forced by using a kernel command line option
1327	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1328	  your boot loader (lilo or loadlin) about how to pass options to the
1329	  kernel at boot time.)
1330
1331	  If unsure, say "off".
1332
1333config HIGHMEM4G
1334	bool "4GB"
1335	---help---
1336	  Select this if you have a 32-bit processor and between 1 and 4
1337	  gigabytes of physical RAM.
1338
1339config HIGHMEM64G
1340	bool "64GB"
1341	depends on !M486
1342	select X86_PAE
1343	---help---
1344	  Select this if you have a 32-bit processor and more than 4
1345	  gigabytes of physical RAM.
1346
1347endchoice
1348
1349choice
1350	prompt "Memory split" if EXPERT
1351	default VMSPLIT_3G
1352	depends on X86_32
1353	---help---
1354	  Select the desired split between kernel and user memory.
1355
1356	  If the address range available to the kernel is less than the
1357	  physical memory installed, the remaining memory will be available
1358	  as "high memory". Accessing high memory is a little more costly
1359	  than low memory, as it needs to be mapped into the kernel first.
1360	  Note that increasing the kernel address space limits the range
1361	  available to user programs, making the address space there
1362	  tighter.  Selecting anything other than the default 3G/1G split
1363	  will also likely make your kernel incompatible with binary-only
1364	  kernel modules.
1365
1366	  If you are not absolutely sure what you are doing, leave this
1367	  option alone!
1368
1369	config VMSPLIT_3G
1370		bool "3G/1G user/kernel split"
1371	config VMSPLIT_3G_OPT
1372		depends on !X86_PAE
1373		bool "3G/1G user/kernel split (for full 1G low memory)"
1374	config VMSPLIT_2G
1375		bool "2G/2G user/kernel split"
1376	config VMSPLIT_2G_OPT
1377		depends on !X86_PAE
1378		bool "2G/2G user/kernel split (for full 2G low memory)"
1379	config VMSPLIT_1G
1380		bool "1G/3G user/kernel split"
1381endchoice
1382
1383config PAGE_OFFSET
1384	hex
1385	default 0xB0000000 if VMSPLIT_3G_OPT
1386	default 0x80000000 if VMSPLIT_2G
1387	default 0x78000000 if VMSPLIT_2G_OPT
1388	default 0x40000000 if VMSPLIT_1G
1389	default 0xC0000000
1390	depends on X86_32
1391
1392config HIGHMEM
1393	def_bool y
1394	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1395
1396config X86_PAE
1397	bool "PAE (Physical Address Extension) Support"
1398	depends on X86_32 && !HIGHMEM4G
1399	select SWIOTLB
1400	---help---
1401	  PAE is required for NX support, and furthermore enables
1402	  larger swapspace support for non-overcommit purposes. It
1403	  has the cost of more pagetable lookup overhead, and also
1404	  consumes more pagetable space per process.
1405
1406config X86_5LEVEL
1407	bool "Enable 5-level page tables support"
1408	depends on X86_64
1409	---help---
1410	  5-level paging enables access to larger address space:
1411	  upto 128 PiB of virtual address space and 4 PiB of
1412	  physical address space.
1413
1414	  It will be supported by future Intel CPUs.
1415
1416	  Note: a kernel with this option enabled can only be booted
1417	  on machines that support the feature.
1418
1419	  See Documentation/x86/x86_64/5level-paging.txt for more
1420	  information.
1421
1422	  Say N if unsure.
1423
1424config ARCH_PHYS_ADDR_T_64BIT
1425	def_bool y
1426	depends on X86_64 || X86_PAE
1427
1428config ARCH_DMA_ADDR_T_64BIT
1429	def_bool y
1430	depends on X86_64 || HIGHMEM64G
1431
1432config X86_DIRECT_GBPAGES
1433	def_bool y
1434	depends on X86_64 && !DEBUG_PAGEALLOC
1435	---help---
1436	  Certain kernel features effectively disable kernel
1437	  linear 1 GB mappings (even if the CPU otherwise
1438	  supports them), so don't confuse the user by printing
1439	  that we have them enabled.
1440
1441config ARCH_HAS_MEM_ENCRYPT
1442	def_bool y
1443
1444config AMD_MEM_ENCRYPT
1445	bool "AMD Secure Memory Encryption (SME) support"
1446	depends on X86_64 && CPU_SUP_AMD
1447	---help---
1448	  Say yes to enable support for the encryption of system memory.
1449	  This requires an AMD processor that supports Secure Memory
1450	  Encryption (SME).
1451
1452config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1453	bool "Activate AMD Secure Memory Encryption (SME) by default"
1454	default y
1455	depends on AMD_MEM_ENCRYPT
1456	---help---
1457	  Say yes to have system memory encrypted by default if running on
1458	  an AMD processor that supports Secure Memory Encryption (SME).
1459
1460	  If set to Y, then the encryption of system memory can be
1461	  deactivated with the mem_encrypt=off command line option.
1462
1463	  If set to N, then the encryption of system memory can be
1464	  activated with the mem_encrypt=on command line option.
1465
1466config ARCH_USE_MEMREMAP_PROT
1467	def_bool y
1468	depends on AMD_MEM_ENCRYPT
1469
1470# Common NUMA Features
1471config NUMA
1472	bool "Numa Memory Allocation and Scheduler Support"
1473	depends on SMP
1474	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1475	default y if X86_BIGSMP
1476	---help---
1477	  Enable NUMA (Non Uniform Memory Access) support.
1478
1479	  The kernel will try to allocate memory used by a CPU on the
1480	  local memory controller of the CPU and add some more
1481	  NUMA awareness to the kernel.
1482
1483	  For 64-bit this is recommended if the system is Intel Core i7
1484	  (or later), AMD Opteron, or EM64T NUMA.
1485
1486	  For 32-bit this is only needed if you boot a 32-bit
1487	  kernel on a 64-bit NUMA platform.
1488
1489	  Otherwise, you should say N.
1490
1491config AMD_NUMA
1492	def_bool y
1493	prompt "Old style AMD Opteron NUMA detection"
1494	depends on X86_64 && NUMA && PCI
1495	---help---
1496	  Enable AMD NUMA node topology detection.  You should say Y here if
1497	  you have a multi processor AMD system. This uses an old method to
1498	  read the NUMA configuration directly from the builtin Northbridge
1499	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1500	  which also takes priority if both are compiled in.
1501
1502config X86_64_ACPI_NUMA
1503	def_bool y
1504	prompt "ACPI NUMA detection"
1505	depends on X86_64 && NUMA && ACPI && PCI
1506	select ACPI_NUMA
1507	---help---
1508	  Enable ACPI SRAT based node topology detection.
1509
1510# Some NUMA nodes have memory ranges that span
1511# other nodes.  Even though a pfn is valid and
1512# between a node's start and end pfns, it may not
1513# reside on that node.  See memmap_init_zone()
1514# for details.
1515config NODES_SPAN_OTHER_NODES
1516	def_bool y
1517	depends on X86_64_ACPI_NUMA
1518
1519config NUMA_EMU
1520	bool "NUMA emulation"
1521	depends on NUMA
1522	---help---
1523	  Enable NUMA emulation. A flat machine will be split
1524	  into virtual nodes when booted with "numa=fake=N", where N is the
1525	  number of nodes. This is only useful for debugging.
1526
1527config NODES_SHIFT
1528	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1529	range 1 10
1530	default "10" if MAXSMP
1531	default "6" if X86_64
1532	default "3"
1533	depends on NEED_MULTIPLE_NODES
1534	---help---
1535	  Specify the maximum number of NUMA Nodes available on the target
1536	  system.  Increases memory reserved to accommodate various tables.
1537
1538config ARCH_HAVE_MEMORY_PRESENT
1539	def_bool y
1540	depends on X86_32 && DISCONTIGMEM
1541
1542config NEED_NODE_MEMMAP_SIZE
1543	def_bool y
1544	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1545
1546config ARCH_FLATMEM_ENABLE
1547	def_bool y
1548	depends on X86_32 && !NUMA
1549
1550config ARCH_DISCONTIGMEM_ENABLE
1551	def_bool y
1552	depends on NUMA && X86_32
1553
1554config ARCH_DISCONTIGMEM_DEFAULT
1555	def_bool y
1556	depends on NUMA && X86_32
1557
1558config ARCH_SPARSEMEM_ENABLE
1559	def_bool y
1560	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1561	select SPARSEMEM_STATIC if X86_32
1562	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1563
1564config ARCH_SPARSEMEM_DEFAULT
1565	def_bool y
1566	depends on X86_64
1567
1568config ARCH_SELECT_MEMORY_MODEL
1569	def_bool y
1570	depends on ARCH_SPARSEMEM_ENABLE
1571
1572config ARCH_MEMORY_PROBE
1573	bool "Enable sysfs memory/probe interface"
1574	depends on X86_64 && MEMORY_HOTPLUG
1575	help
1576	  This option enables a sysfs memory/probe interface for testing.
1577	  See Documentation/memory-hotplug.txt for more information.
1578	  If you are unsure how to answer this question, answer N.
1579
1580config ARCH_PROC_KCORE_TEXT
1581	def_bool y
1582	depends on X86_64 && PROC_KCORE
1583
1584config ILLEGAL_POINTER_VALUE
1585       hex
1586       default 0 if X86_32
1587       default 0xdead000000000000 if X86_64
1588
1589source "mm/Kconfig"
1590
1591config X86_PMEM_LEGACY_DEVICE
1592	bool
1593
1594config X86_PMEM_LEGACY
1595	tristate "Support non-standard NVDIMMs and ADR protected memory"
1596	depends on PHYS_ADDR_T_64BIT
1597	depends on BLK_DEV
1598	select X86_PMEM_LEGACY_DEVICE
1599	select LIBNVDIMM
1600	help
1601	  Treat memory marked using the non-standard e820 type of 12 as used
1602	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1603	  The kernel will offer these regions to the 'pmem' driver so
1604	  they can be used for persistent storage.
1605
1606	  Say Y if unsure.
1607
1608config HIGHPTE
1609	bool "Allocate 3rd-level pagetables from highmem"
1610	depends on HIGHMEM
1611	---help---
1612	  The VM uses one page table entry for each page of physical memory.
1613	  For systems with a lot of RAM, this can be wasteful of precious
1614	  low memory.  Setting this option will put user-space page table
1615	  entries in high memory.
1616
1617config X86_CHECK_BIOS_CORRUPTION
1618	bool "Check for low memory corruption"
1619	---help---
1620	  Periodically check for memory corruption in low memory, which
1621	  is suspected to be caused by BIOS.  Even when enabled in the
1622	  configuration, it is disabled at runtime.  Enable it by
1623	  setting "memory_corruption_check=1" on the kernel command
1624	  line.  By default it scans the low 64k of memory every 60
1625	  seconds; see the memory_corruption_check_size and
1626	  memory_corruption_check_period parameters in
1627	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1628
1629	  When enabled with the default parameters, this option has
1630	  almost no overhead, as it reserves a relatively small amount
1631	  of memory and scans it infrequently.  It both detects corruption
1632	  and prevents it from affecting the running system.
1633
1634	  It is, however, intended as a diagnostic tool; if repeatable
1635	  BIOS-originated corruption always affects the same memory,
1636	  you can use memmap= to prevent the kernel from using that
1637	  memory.
1638
1639config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1640	bool "Set the default setting of memory_corruption_check"
1641	depends on X86_CHECK_BIOS_CORRUPTION
1642	default y
1643	---help---
1644	  Set whether the default state of memory_corruption_check is
1645	  on or off.
1646
1647config X86_RESERVE_LOW
1648	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1649	default 64
1650	range 4 640
1651	---help---
1652	  Specify the amount of low memory to reserve for the BIOS.
1653
1654	  The first page contains BIOS data structures that the kernel
1655	  must not use, so that page must always be reserved.
1656
1657	  By default we reserve the first 64K of physical RAM, as a
1658	  number of BIOSes are known to corrupt that memory range
1659	  during events such as suspend/resume or monitor cable
1660	  insertion, so it must not be used by the kernel.
1661
1662	  You can set this to 4 if you are absolutely sure that you
1663	  trust the BIOS to get all its memory reservations and usages
1664	  right.  If you know your BIOS have problems beyond the
1665	  default 64K area, you can set this to 640 to avoid using the
1666	  entire low memory range.
1667
1668	  If you have doubts about the BIOS (e.g. suspend/resume does
1669	  not work or there's kernel crashes after certain hardware
1670	  hotplug events) then you might want to enable
1671	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1672	  typical corruption patterns.
1673
1674	  Leave this to the default value of 64 if you are unsure.
1675
1676config MATH_EMULATION
1677	bool
1678	depends on MODIFY_LDT_SYSCALL
1679	prompt "Math emulation" if X86_32
1680	---help---
1681	  Linux can emulate a math coprocessor (used for floating point
1682	  operations) if you don't have one. 486DX and Pentium processors have
1683	  a math coprocessor built in, 486SX and 386 do not, unless you added
1684	  a 487DX or 387, respectively. (The messages during boot time can
1685	  give you some hints here ["man dmesg"].) Everyone needs either a
1686	  coprocessor or this emulation.
1687
1688	  If you don't have a math coprocessor, you need to say Y here; if you
1689	  say Y here even though you have a coprocessor, the coprocessor will
1690	  be used nevertheless. (This behavior can be changed with the kernel
1691	  command line option "no387", which comes handy if your coprocessor
1692	  is broken. Try "man bootparam" or see the documentation of your boot
1693	  loader (lilo or loadlin) about how to pass options to the kernel at
1694	  boot time.) This means that it is a good idea to say Y here if you
1695	  intend to use this kernel on different machines.
1696
1697	  More information about the internals of the Linux math coprocessor
1698	  emulation can be found in <file:arch/x86/math-emu/README>.
1699
1700	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1701	  kernel, it won't hurt.
1702
1703config MTRR
1704	def_bool y
1705	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1706	---help---
1707	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1708	  the Memory Type Range Registers (MTRRs) may be used to control
1709	  processor access to memory ranges. This is most useful if you have
1710	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1711	  allows bus write transfers to be combined into a larger transfer
1712	  before bursting over the PCI/AGP bus. This can increase performance
1713	  of image write operations 2.5 times or more. Saying Y here creates a
1714	  /proc/mtrr file which may be used to manipulate your processor's
1715	  MTRRs. Typically the X server should use this.
1716
1717	  This code has a reasonably generic interface so that similar
1718	  control registers on other processors can be easily supported
1719	  as well:
1720
1721	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1722	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1723	  these, the ARRs are used to emulate the MTRRs.
1724	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1725	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1726	  write-combining. All of these processors are supported by this code
1727	  and it makes sense to say Y here if you have one of them.
1728
1729	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1730	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1731	  can lead to all sorts of problems, so it's good to say Y here.
1732
1733	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1734	  just add about 9 KB to your kernel.
1735
1736	  See <file:Documentation/x86/mtrr.txt> for more information.
1737
1738config MTRR_SANITIZER
1739	def_bool y
1740	prompt "MTRR cleanup support"
1741	depends on MTRR
1742	---help---
1743	  Convert MTRR layout from continuous to discrete, so X drivers can
1744	  add writeback entries.
1745
1746	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1747	  The largest mtrr entry size for a continuous block can be set with
1748	  mtrr_chunk_size.
1749
1750	  If unsure, say Y.
1751
1752config MTRR_SANITIZER_ENABLE_DEFAULT
1753	int "MTRR cleanup enable value (0-1)"
1754	range 0 1
1755	default "0"
1756	depends on MTRR_SANITIZER
1757	---help---
1758	  Enable mtrr cleanup default value
1759
1760config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1761	int "MTRR cleanup spare reg num (0-7)"
1762	range 0 7
1763	default "1"
1764	depends on MTRR_SANITIZER
1765	---help---
1766	  mtrr cleanup spare entries default, it can be changed via
1767	  mtrr_spare_reg_nr=N on the kernel command line.
1768
1769config X86_PAT
1770	def_bool y
1771	prompt "x86 PAT support" if EXPERT
1772	depends on MTRR
1773	---help---
1774	  Use PAT attributes to setup page level cache control.
1775
1776	  PATs are the modern equivalents of MTRRs and are much more
1777	  flexible than MTRRs.
1778
1779	  Say N here if you see bootup problems (boot crash, boot hang,
1780	  spontaneous reboots) or a non-working video driver.
1781
1782	  If unsure, say Y.
1783
1784config ARCH_USES_PG_UNCACHED
1785	def_bool y
1786	depends on X86_PAT
1787
1788config ARCH_RANDOM
1789	def_bool y
1790	prompt "x86 architectural random number generator" if EXPERT
1791	---help---
1792	  Enable the x86 architectural RDRAND instruction
1793	  (Intel Bull Mountain technology) to generate random numbers.
1794	  If supported, this is a high bandwidth, cryptographically
1795	  secure hardware random number generator.
1796
1797config X86_SMAP
1798	def_bool y
1799	prompt "Supervisor Mode Access Prevention" if EXPERT
1800	---help---
1801	  Supervisor Mode Access Prevention (SMAP) is a security
1802	  feature in newer Intel processors.  There is a small
1803	  performance cost if this enabled and turned on; there is
1804	  also a small increase in the kernel size if this is enabled.
1805
1806	  If unsure, say Y.
1807
1808config X86_INTEL_UMIP
1809	def_bool y
1810	depends on CPU_SUP_INTEL
1811	prompt "Intel User Mode Instruction Prevention" if EXPERT
1812	---help---
1813	  The User Mode Instruction Prevention (UMIP) is a security
1814	  feature in newer Intel processors. If enabled, a general
1815	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1816	  or STR instructions are executed in user mode. These instructions
1817	  unnecessarily expose information about the hardware state.
1818
1819	  The vast majority of applications do not use these instructions.
1820	  For the very few that do, software emulation is provided in
1821	  specific cases in protected and virtual-8086 modes. Emulated
1822	  results are dummy.
1823
1824config X86_INTEL_MPX
1825	prompt "Intel MPX (Memory Protection Extensions)"
1826	def_bool n
1827	# Note: only available in 64-bit mode due to VMA flags shortage
1828	depends on CPU_SUP_INTEL && X86_64
1829	select ARCH_USES_HIGH_VMA_FLAGS
1830	---help---
1831	  MPX provides hardware features that can be used in
1832	  conjunction with compiler-instrumented code to check
1833	  memory references.  It is designed to detect buffer
1834	  overflow or underflow bugs.
1835
1836	  This option enables running applications which are
1837	  instrumented or otherwise use MPX.  It does not use MPX
1838	  itself inside the kernel or to protect the kernel
1839	  against bad memory references.
1840
1841	  Enabling this option will make the kernel larger:
1842	  ~8k of kernel text and 36 bytes of data on a 64-bit
1843	  defconfig.  It adds a long to the 'mm_struct' which
1844	  will increase the kernel memory overhead of each
1845	  process and adds some branches to paths used during
1846	  exec() and munmap().
1847
1848	  For details, see Documentation/x86/intel_mpx.txt
1849
1850	  If unsure, say N.
1851
1852config X86_INTEL_MEMORY_PROTECTION_KEYS
1853	prompt "Intel Memory Protection Keys"
1854	def_bool y
1855	# Note: only available in 64-bit mode
1856	depends on CPU_SUP_INTEL && X86_64
1857	select ARCH_USES_HIGH_VMA_FLAGS
1858	select ARCH_HAS_PKEYS
1859	---help---
1860	  Memory Protection Keys provides a mechanism for enforcing
1861	  page-based protections, but without requiring modification of the
1862	  page tables when an application changes protection domains.
1863
1864	  For details, see Documentation/x86/protection-keys.txt
1865
1866	  If unsure, say y.
1867
1868config EFI
1869	bool "EFI runtime service support"
1870	depends on ACPI
1871	select UCS2_STRING
1872	select EFI_RUNTIME_WRAPPERS
1873	---help---
1874	  This enables the kernel to use EFI runtime services that are
1875	  available (such as the EFI variable services).
1876
1877	  This option is only useful on systems that have EFI firmware.
1878	  In addition, you should use the latest ELILO loader available
1879	  at <http://elilo.sourceforge.net> in order to take advantage
1880	  of EFI runtime services. However, even with this option, the
1881	  resultant kernel should continue to boot on existing non-EFI
1882	  platforms.
1883
1884config EFI_STUB
1885       bool "EFI stub support"
1886       depends on EFI && !X86_USE_3DNOW
1887       select RELOCATABLE
1888       ---help---
1889          This kernel feature allows a bzImage to be loaded directly
1890	  by EFI firmware without the use of a bootloader.
1891
1892	  See Documentation/efi-stub.txt for more information.
1893
1894config EFI_MIXED
1895	bool "EFI mixed-mode support"
1896	depends on EFI_STUB && X86_64
1897	---help---
1898	   Enabling this feature allows a 64-bit kernel to be booted
1899	   on a 32-bit firmware, provided that your CPU supports 64-bit
1900	   mode.
1901
1902	   Note that it is not possible to boot a mixed-mode enabled
1903	   kernel via the EFI boot stub - a bootloader that supports
1904	   the EFI handover protocol must be used.
1905
1906	   If unsure, say N.
1907
1908config SECCOMP
1909	def_bool y
1910	prompt "Enable seccomp to safely compute untrusted bytecode"
1911	---help---
1912	  This kernel feature is useful for number crunching applications
1913	  that may need to compute untrusted bytecode during their
1914	  execution. By using pipes or other transports made available to
1915	  the process as file descriptors supporting the read/write
1916	  syscalls, it's possible to isolate those applications in
1917	  their own address space using seccomp. Once seccomp is
1918	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1919	  and the task is only allowed to execute a few safe syscalls
1920	  defined by each seccomp mode.
1921
1922	  If unsure, say Y. Only embedded should say N here.
1923
1924source kernel/Kconfig.hz
1925
1926config KEXEC
1927	bool "kexec system call"
1928	select KEXEC_CORE
1929	---help---
1930	  kexec is a system call that implements the ability to shutdown your
1931	  current kernel, and to start another kernel.  It is like a reboot
1932	  but it is independent of the system firmware.   And like a reboot
1933	  you can start any kernel with it, not just Linux.
1934
1935	  The name comes from the similarity to the exec system call.
1936
1937	  It is an ongoing process to be certain the hardware in a machine
1938	  is properly shutdown, so do not be surprised if this code does not
1939	  initially work for you.  As of this writing the exact hardware
1940	  interface is strongly in flux, so no good recommendation can be
1941	  made.
1942
1943config KEXEC_FILE
1944	bool "kexec file based system call"
1945	select KEXEC_CORE
1946	select BUILD_BIN2C
1947	depends on X86_64
1948	depends on CRYPTO=y
1949	depends on CRYPTO_SHA256=y
1950	---help---
1951	  This is new version of kexec system call. This system call is
1952	  file based and takes file descriptors as system call argument
1953	  for kernel and initramfs as opposed to list of segments as
1954	  accepted by previous system call.
1955
1956config KEXEC_VERIFY_SIG
1957	bool "Verify kernel signature during kexec_file_load() syscall"
1958	depends on KEXEC_FILE
1959	---help---
1960	  This option makes kernel signature verification mandatory for
1961	  the kexec_file_load() syscall.
1962
1963	  In addition to that option, you need to enable signature
1964	  verification for the corresponding kernel image type being
1965	  loaded in order for this to work.
1966
1967config KEXEC_BZIMAGE_VERIFY_SIG
1968	bool "Enable bzImage signature verification support"
1969	depends on KEXEC_VERIFY_SIG
1970	depends on SIGNED_PE_FILE_VERIFICATION
1971	select SYSTEM_TRUSTED_KEYRING
1972	---help---
1973	  Enable bzImage signature verification support.
1974
1975config CRASH_DUMP
1976	bool "kernel crash dumps"
1977	depends on X86_64 || (X86_32 && HIGHMEM)
1978	---help---
1979	  Generate crash dump after being started by kexec.
1980	  This should be normally only set in special crash dump kernels
1981	  which are loaded in the main kernel with kexec-tools into
1982	  a specially reserved region and then later executed after
1983	  a crash by kdump/kexec. The crash dump kernel must be compiled
1984	  to a memory address not used by the main kernel or BIOS using
1985	  PHYSICAL_START, or it must be built as a relocatable image
1986	  (CONFIG_RELOCATABLE=y).
1987	  For more details see Documentation/kdump/kdump.txt
1988
1989config KEXEC_JUMP
1990	bool "kexec jump"
1991	depends on KEXEC && HIBERNATION
1992	---help---
1993	  Jump between original kernel and kexeced kernel and invoke
1994	  code in physical address mode via KEXEC
1995
1996config PHYSICAL_START
1997	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1998	default "0x1000000"
1999	---help---
2000	  This gives the physical address where the kernel is loaded.
2001
2002	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2003	  bzImage will decompress itself to above physical address and
2004	  run from there. Otherwise, bzImage will run from the address where
2005	  it has been loaded by the boot loader and will ignore above physical
2006	  address.
2007
2008	  In normal kdump cases one does not have to set/change this option
2009	  as now bzImage can be compiled as a completely relocatable image
2010	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2011	  address. This option is mainly useful for the folks who don't want
2012	  to use a bzImage for capturing the crash dump and want to use a
2013	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2014	  to be specifically compiled to run from a specific memory area
2015	  (normally a reserved region) and this option comes handy.
2016
2017	  So if you are using bzImage for capturing the crash dump,
2018	  leave the value here unchanged to 0x1000000 and set
2019	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2020	  for capturing the crash dump change this value to start of
2021	  the reserved region.  In other words, it can be set based on
2022	  the "X" value as specified in the "crashkernel=YM@XM"
2023	  command line boot parameter passed to the panic-ed
2024	  kernel. Please take a look at Documentation/kdump/kdump.txt
2025	  for more details about crash dumps.
2026
2027	  Usage of bzImage for capturing the crash dump is recommended as
2028	  one does not have to build two kernels. Same kernel can be used
2029	  as production kernel and capture kernel. Above option should have
2030	  gone away after relocatable bzImage support is introduced. But it
2031	  is present because there are users out there who continue to use
2032	  vmlinux for dump capture. This option should go away down the
2033	  line.
2034
2035	  Don't change this unless you know what you are doing.
2036
2037config RELOCATABLE
2038	bool "Build a relocatable kernel"
2039	default y
2040	---help---
2041	  This builds a kernel image that retains relocation information
2042	  so it can be loaded someplace besides the default 1MB.
2043	  The relocations tend to make the kernel binary about 10% larger,
2044	  but are discarded at runtime.
2045
2046	  One use is for the kexec on panic case where the recovery kernel
2047	  must live at a different physical address than the primary
2048	  kernel.
2049
2050	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2051	  it has been loaded at and the compile time physical address
2052	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2053
2054config RANDOMIZE_BASE
2055	bool "Randomize the address of the kernel image (KASLR)"
2056	depends on RELOCATABLE
2057	default y
2058	---help---
2059	  In support of Kernel Address Space Layout Randomization (KASLR),
2060	  this randomizes the physical address at which the kernel image
2061	  is decompressed and the virtual address where the kernel
2062	  image is mapped, as a security feature that deters exploit
2063	  attempts relying on knowledge of the location of kernel
2064	  code internals.
2065
2066	  On 64-bit, the kernel physical and virtual addresses are
2067	  randomized separately. The physical address will be anywhere
2068	  between 16MB and the top of physical memory (up to 64TB). The
2069	  virtual address will be randomized from 16MB up to 1GB (9 bits
2070	  of entropy). Note that this also reduces the memory space
2071	  available to kernel modules from 1.5GB to 1GB.
2072
2073	  On 32-bit, the kernel physical and virtual addresses are
2074	  randomized together. They will be randomized from 16MB up to
2075	  512MB (8 bits of entropy).
2076
2077	  Entropy is generated using the RDRAND instruction if it is
2078	  supported. If RDTSC is supported, its value is mixed into
2079	  the entropy pool as well. If neither RDRAND nor RDTSC are
2080	  supported, then entropy is read from the i8254 timer. The
2081	  usable entropy is limited by the kernel being built using
2082	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2083	  minimum of 2MB. As a result, only 10 bits of entropy are
2084	  theoretically possible, but the implementations are further
2085	  limited due to memory layouts.
2086
2087	  If unsure, say Y.
2088
2089# Relocation on x86 needs some additional build support
2090config X86_NEED_RELOCS
2091	def_bool y
2092	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2093
2094config PHYSICAL_ALIGN
2095	hex "Alignment value to which kernel should be aligned"
2096	default "0x200000"
2097	range 0x2000 0x1000000 if X86_32
2098	range 0x200000 0x1000000 if X86_64
2099	---help---
2100	  This value puts the alignment restrictions on physical address
2101	  where kernel is loaded and run from. Kernel is compiled for an
2102	  address which meets above alignment restriction.
2103
2104	  If bootloader loads the kernel at a non-aligned address and
2105	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2106	  address aligned to above value and run from there.
2107
2108	  If bootloader loads the kernel at a non-aligned address and
2109	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2110	  load address and decompress itself to the address it has been
2111	  compiled for and run from there. The address for which kernel is
2112	  compiled already meets above alignment restrictions. Hence the
2113	  end result is that kernel runs from a physical address meeting
2114	  above alignment restrictions.
2115
2116	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2117	  this value must be a multiple of 0x200000.
2118
2119	  Don't change this unless you know what you are doing.
2120
2121config RANDOMIZE_MEMORY
2122	bool "Randomize the kernel memory sections"
2123	depends on X86_64
2124	depends on RANDOMIZE_BASE
2125	default RANDOMIZE_BASE
2126	---help---
2127	   Randomizes the base virtual address of kernel memory sections
2128	   (physical memory mapping, vmalloc & vmemmap). This security feature
2129	   makes exploits relying on predictable memory locations less reliable.
2130
2131	   The order of allocations remains unchanged. Entropy is generated in
2132	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2133	   configuration have in average 30,000 different possible virtual
2134	   addresses for each memory section.
2135
2136	   If unsure, say Y.
2137
2138config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2139	hex "Physical memory mapping padding" if EXPERT
2140	depends on RANDOMIZE_MEMORY
2141	default "0xa" if MEMORY_HOTPLUG
2142	default "0x0"
2143	range 0x1 0x40 if MEMORY_HOTPLUG
2144	range 0x0 0x40
2145	---help---
2146	   Define the padding in terabytes added to the existing physical
2147	   memory size during kernel memory randomization. It is useful
2148	   for memory hotplug support but reduces the entropy available for
2149	   address randomization.
2150
2151	   If unsure, leave at the default value.
2152
2153config HOTPLUG_CPU
2154	bool "Support for hot-pluggable CPUs"
2155	depends on SMP
2156	---help---
2157	  Say Y here to allow turning CPUs off and on. CPUs can be
2158	  controlled through /sys/devices/system/cpu.
2159	  ( Note: power management support will enable this option
2160	    automatically on SMP systems. )
2161	  Say N if you want to disable CPU hotplug.
2162
2163config BOOTPARAM_HOTPLUG_CPU0
2164	bool "Set default setting of cpu0_hotpluggable"
2165	default n
2166	depends on HOTPLUG_CPU
2167	---help---
2168	  Set whether default state of cpu0_hotpluggable is on or off.
2169
2170	  Say Y here to enable CPU0 hotplug by default. If this switch
2171	  is turned on, there is no need to give cpu0_hotplug kernel
2172	  parameter and the CPU0 hotplug feature is enabled by default.
2173
2174	  Please note: there are two known CPU0 dependencies if you want
2175	  to enable the CPU0 hotplug feature either by this switch or by
2176	  cpu0_hotplug kernel parameter.
2177
2178	  First, resume from hibernate or suspend always starts from CPU0.
2179	  So hibernate and suspend are prevented if CPU0 is offline.
2180
2181	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2182	  offline if any interrupt can not migrate out of CPU0. There may
2183	  be other CPU0 dependencies.
2184
2185	  Please make sure the dependencies are under your control before
2186	  you enable this feature.
2187
2188	  Say N if you don't want to enable CPU0 hotplug feature by default.
2189	  You still can enable the CPU0 hotplug feature at boot by kernel
2190	  parameter cpu0_hotplug.
2191
2192config DEBUG_HOTPLUG_CPU0
2193	def_bool n
2194	prompt "Debug CPU0 hotplug"
2195	depends on HOTPLUG_CPU
2196	---help---
2197	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2198	  soon as possible and boots up userspace with CPU0 offlined. User
2199	  can online CPU0 back after boot time.
2200
2201	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2202	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2203	  compilation or giving cpu0_hotplug kernel parameter at boot.
2204
2205	  If unsure, say N.
2206
2207config COMPAT_VDSO
2208	def_bool n
2209	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2210	depends on COMPAT_32
2211	---help---
2212	  Certain buggy versions of glibc will crash if they are
2213	  presented with a 32-bit vDSO that is not mapped at the address
2214	  indicated in its segment table.
2215
2216	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2217	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2218	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2219	  the only released version with the bug, but OpenSUSE 9
2220	  contains a buggy "glibc 2.3.2".
2221
2222	  The symptom of the bug is that everything crashes on startup, saying:
2223	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2224
2225	  Saying Y here changes the default value of the vdso32 boot
2226	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2227	  This works around the glibc bug but hurts performance.
2228
2229	  If unsure, say N: if you are compiling your own kernel, you
2230	  are unlikely to be using a buggy version of glibc.
2231
2232choice
2233	prompt "vsyscall table for legacy applications"
2234	depends on X86_64
2235	default LEGACY_VSYSCALL_EMULATE
2236	help
2237	  Legacy user code that does not know how to find the vDSO expects
2238	  to be able to issue three syscalls by calling fixed addresses in
2239	  kernel space. Since this location is not randomized with ASLR,
2240	  it can be used to assist security vulnerability exploitation.
2241
2242	  This setting can be changed at boot time via the kernel command
2243	  line parameter vsyscall=[native|emulate|none].
2244
2245	  On a system with recent enough glibc (2.14 or newer) and no
2246	  static binaries, you can say None without a performance penalty
2247	  to improve security.
2248
2249	  If unsure, select "Emulate".
2250
2251	config LEGACY_VSYSCALL_NATIVE
2252		bool "Native"
2253		help
2254		  Actual executable code is located in the fixed vsyscall
2255		  address mapping, implementing time() efficiently. Since
2256		  this makes the mapping executable, it can be used during
2257		  security vulnerability exploitation (traditionally as
2258		  ROP gadgets). This configuration is not recommended.
2259
2260	config LEGACY_VSYSCALL_EMULATE
2261		bool "Emulate"
2262		help
2263		  The kernel traps and emulates calls into the fixed
2264		  vsyscall address mapping. This makes the mapping
2265		  non-executable, but it still contains known contents,
2266		  which could be used in certain rare security vulnerability
2267		  exploits. This configuration is recommended when userspace
2268		  still uses the vsyscall area.
2269
2270	config LEGACY_VSYSCALL_NONE
2271		bool "None"
2272		help
2273		  There will be no vsyscall mapping at all. This will
2274		  eliminate any risk of ASLR bypass due to the vsyscall
2275		  fixed address mapping. Attempts to use the vsyscalls
2276		  will be reported to dmesg, so that either old or
2277		  malicious userspace programs can be identified.
2278
2279endchoice
2280
2281config CMDLINE_BOOL
2282	bool "Built-in kernel command line"
2283	---help---
2284	  Allow for specifying boot arguments to the kernel at
2285	  build time.  On some systems (e.g. embedded ones), it is
2286	  necessary or convenient to provide some or all of the
2287	  kernel boot arguments with the kernel itself (that is,
2288	  to not rely on the boot loader to provide them.)
2289
2290	  To compile command line arguments into the kernel,
2291	  set this option to 'Y', then fill in the
2292	  boot arguments in CONFIG_CMDLINE.
2293
2294	  Systems with fully functional boot loaders (i.e. non-embedded)
2295	  should leave this option set to 'N'.
2296
2297config CMDLINE
2298	string "Built-in kernel command string"
2299	depends on CMDLINE_BOOL
2300	default ""
2301	---help---
2302	  Enter arguments here that should be compiled into the kernel
2303	  image and used at boot time.  If the boot loader provides a
2304	  command line at boot time, it is appended to this string to
2305	  form the full kernel command line, when the system boots.
2306
2307	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2308	  change this behavior.
2309
2310	  In most cases, the command line (whether built-in or provided
2311	  by the boot loader) should specify the device for the root
2312	  file system.
2313
2314config CMDLINE_OVERRIDE
2315	bool "Built-in command line overrides boot loader arguments"
2316	depends on CMDLINE_BOOL
2317	---help---
2318	  Set this option to 'Y' to have the kernel ignore the boot loader
2319	  command line, and use ONLY the built-in command line.
2320
2321	  This is used to work around broken boot loaders.  This should
2322	  be set to 'N' under normal conditions.
2323
2324config MODIFY_LDT_SYSCALL
2325	bool "Enable the LDT (local descriptor table)" if EXPERT
2326	default y
2327	---help---
2328	  Linux can allow user programs to install a per-process x86
2329	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2330	  call.  This is required to run 16-bit or segmented code such as
2331	  DOSEMU or some Wine programs.  It is also used by some very old
2332	  threading libraries.
2333
2334	  Enabling this feature adds a small amount of overhead to
2335	  context switches and increases the low-level kernel attack
2336	  surface.  Disabling it removes the modify_ldt(2) system call.
2337
2338	  Saying 'N' here may make sense for embedded or server kernels.
2339
2340source "kernel/livepatch/Kconfig"
2341
2342endmenu
2343
2344config ARCH_HAS_ADD_PAGES
2345	def_bool y
2346	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2347
2348config ARCH_ENABLE_MEMORY_HOTPLUG
2349	def_bool y
2350	depends on X86_64 || (X86_32 && HIGHMEM)
2351
2352config ARCH_ENABLE_MEMORY_HOTREMOVE
2353	def_bool y
2354	depends on MEMORY_HOTPLUG
2355
2356config USE_PERCPU_NUMA_NODE_ID
2357	def_bool y
2358	depends on NUMA
2359
2360config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2361	def_bool y
2362	depends on X86_64 || X86_PAE
2363
2364config ARCH_ENABLE_HUGEPAGE_MIGRATION
2365	def_bool y
2366	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2367
2368config ARCH_ENABLE_THP_MIGRATION
2369	def_bool y
2370	depends on X86_64 && TRANSPARENT_HUGEPAGE
2371
2372menu "Power management and ACPI options"
2373
2374config ARCH_HIBERNATION_HEADER
2375	def_bool y
2376	depends on X86_64 && HIBERNATION
2377
2378source "kernel/power/Kconfig"
2379
2380source "drivers/acpi/Kconfig"
2381
2382source "drivers/sfi/Kconfig"
2383
2384config X86_APM_BOOT
2385	def_bool y
2386	depends on APM
2387
2388menuconfig APM
2389	tristate "APM (Advanced Power Management) BIOS support"
2390	depends on X86_32 && PM_SLEEP
2391	---help---
2392	  APM is a BIOS specification for saving power using several different
2393	  techniques. This is mostly useful for battery powered laptops with
2394	  APM compliant BIOSes. If you say Y here, the system time will be
2395	  reset after a RESUME operation, the /proc/apm device will provide
2396	  battery status information, and user-space programs will receive
2397	  notification of APM "events" (e.g. battery status change).
2398
2399	  If you select "Y" here, you can disable actual use of the APM
2400	  BIOS by passing the "apm=off" option to the kernel at boot time.
2401
2402	  Note that the APM support is almost completely disabled for
2403	  machines with more than one CPU.
2404
2405	  In order to use APM, you will need supporting software. For location
2406	  and more information, read <file:Documentation/power/apm-acpi.txt>
2407	  and the Battery Powered Linux mini-HOWTO, available from
2408	  <http://www.tldp.org/docs.html#howto>.
2409
2410	  This driver does not spin down disk drives (see the hdparm(8)
2411	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2412	  VESA-compliant "green" monitors.
2413
2414	  This driver does not support the TI 4000M TravelMate and the ACER
2415	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2416	  desktop machines also don't have compliant BIOSes, and this driver
2417	  may cause those machines to panic during the boot phase.
2418
2419	  Generally, if you don't have a battery in your machine, there isn't
2420	  much point in using this driver and you should say N. If you get
2421	  random kernel OOPSes or reboots that don't seem to be related to
2422	  anything, try disabling/enabling this option (or disabling/enabling
2423	  APM in your BIOS).
2424
2425	  Some other things you should try when experiencing seemingly random,
2426	  "weird" problems:
2427
2428	  1) make sure that you have enough swap space and that it is
2429	  enabled.
2430	  2) pass the "no-hlt" option to the kernel
2431	  3) switch on floating point emulation in the kernel and pass
2432	  the "no387" option to the kernel
2433	  4) pass the "floppy=nodma" option to the kernel
2434	  5) pass the "mem=4M" option to the kernel (thereby disabling
2435	  all but the first 4 MB of RAM)
2436	  6) make sure that the CPU is not over clocked.
2437	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2438	  8) disable the cache from your BIOS settings
2439	  9) install a fan for the video card or exchange video RAM
2440	  10) install a better fan for the CPU
2441	  11) exchange RAM chips
2442	  12) exchange the motherboard.
2443
2444	  To compile this driver as a module, choose M here: the
2445	  module will be called apm.
2446
2447if APM
2448
2449config APM_IGNORE_USER_SUSPEND
2450	bool "Ignore USER SUSPEND"
2451	---help---
2452	  This option will ignore USER SUSPEND requests. On machines with a
2453	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2454	  series notebooks, it is necessary to say Y because of a BIOS bug.
2455
2456config APM_DO_ENABLE
2457	bool "Enable PM at boot time"
2458	---help---
2459	  Enable APM features at boot time. From page 36 of the APM BIOS
2460	  specification: "When disabled, the APM BIOS does not automatically
2461	  power manage devices, enter the Standby State, enter the Suspend
2462	  State, or take power saving steps in response to CPU Idle calls."
2463	  This driver will make CPU Idle calls when Linux is idle (unless this
2464	  feature is turned off -- see "Do CPU IDLE calls", below). This
2465	  should always save battery power, but more complicated APM features
2466	  will be dependent on your BIOS implementation. You may need to turn
2467	  this option off if your computer hangs at boot time when using APM
2468	  support, or if it beeps continuously instead of suspending. Turn
2469	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2470	  T400CDT. This is off by default since most machines do fine without
2471	  this feature.
2472
2473config APM_CPU_IDLE
2474	depends on CPU_IDLE
2475	bool "Make CPU Idle calls when idle"
2476	---help---
2477	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2478	  On some machines, this can activate improved power savings, such as
2479	  a slowed CPU clock rate, when the machine is idle. These idle calls
2480	  are made after the idle loop has run for some length of time (e.g.,
2481	  333 mS). On some machines, this will cause a hang at boot time or
2482	  whenever the CPU becomes idle. (On machines with more than one CPU,
2483	  this option does nothing.)
2484
2485config APM_DISPLAY_BLANK
2486	bool "Enable console blanking using APM"
2487	---help---
2488	  Enable console blanking using the APM. Some laptops can use this to
2489	  turn off the LCD backlight when the screen blanker of the Linux
2490	  virtual console blanks the screen. Note that this is only used by
2491	  the virtual console screen blanker, and won't turn off the backlight
2492	  when using the X Window system. This also doesn't have anything to
2493	  do with your VESA-compliant power-saving monitor. Further, this
2494	  option doesn't work for all laptops -- it might not turn off your
2495	  backlight at all, or it might print a lot of errors to the console,
2496	  especially if you are using gpm.
2497
2498config APM_ALLOW_INTS
2499	bool "Allow interrupts during APM BIOS calls"
2500	---help---
2501	  Normally we disable external interrupts while we are making calls to
2502	  the APM BIOS as a measure to lessen the effects of a badly behaving
2503	  BIOS implementation.  The BIOS should reenable interrupts if it
2504	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2505	  many of the newer IBM Thinkpads.  If you experience hangs when you
2506	  suspend, try setting this to Y.  Otherwise, say N.
2507
2508endif # APM
2509
2510source "drivers/cpufreq/Kconfig"
2511
2512source "drivers/cpuidle/Kconfig"
2513
2514source "drivers/idle/Kconfig"
2515
2516endmenu
2517
2518
2519menu "Bus options (PCI etc.)"
2520
2521config PCI
2522	bool "PCI support"
2523	default y
2524	---help---
2525	  Find out whether you have a PCI motherboard. PCI is the name of a
2526	  bus system, i.e. the way the CPU talks to the other stuff inside
2527	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2528	  VESA. If you have PCI, say Y, otherwise N.
2529
2530choice
2531	prompt "PCI access mode"
2532	depends on X86_32 && PCI
2533	default PCI_GOANY
2534	---help---
2535	  On PCI systems, the BIOS can be used to detect the PCI devices and
2536	  determine their configuration. However, some old PCI motherboards
2537	  have BIOS bugs and may crash if this is done. Also, some embedded
2538	  PCI-based systems don't have any BIOS at all. Linux can also try to
2539	  detect the PCI hardware directly without using the BIOS.
2540
2541	  With this option, you can specify how Linux should detect the
2542	  PCI devices. If you choose "BIOS", the BIOS will be used,
2543	  if you choose "Direct", the BIOS won't be used, and if you
2544	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2545	  If you choose "Any", the kernel will try MMCONFIG, then the
2546	  direct access method and falls back to the BIOS if that doesn't
2547	  work. If unsure, go with the default, which is "Any".
2548
2549config PCI_GOBIOS
2550	bool "BIOS"
2551
2552config PCI_GOMMCONFIG
2553	bool "MMConfig"
2554
2555config PCI_GODIRECT
2556	bool "Direct"
2557
2558config PCI_GOOLPC
2559	bool "OLPC XO-1"
2560	depends on OLPC
2561
2562config PCI_GOANY
2563	bool "Any"
2564
2565endchoice
2566
2567config PCI_BIOS
2568	def_bool y
2569	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2570
2571# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2572config PCI_DIRECT
2573	def_bool y
2574	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2575
2576config PCI_MMCONFIG
2577	def_bool y
2578	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2579
2580config PCI_OLPC
2581	def_bool y
2582	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2583
2584config PCI_XEN
2585	def_bool y
2586	depends on PCI && XEN
2587	select SWIOTLB_XEN
2588
2589config PCI_DOMAINS
2590	def_bool y
2591	depends on PCI
2592
2593config PCI_MMCONFIG
2594	bool "Support mmconfig PCI config space access"
2595	depends on X86_64 && PCI && ACPI
2596
2597config PCI_CNB20LE_QUIRK
2598	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2599	depends on PCI
2600	help
2601	  Read the PCI windows out of the CNB20LE host bridge. This allows
2602	  PCI hotplug to work on systems with the CNB20LE chipset which do
2603	  not have ACPI.
2604
2605	  There's no public spec for this chipset, and this functionality
2606	  is known to be incomplete.
2607
2608	  You should say N unless you know you need this.
2609
2610source "drivers/pci/Kconfig"
2611
2612config ISA_BUS
2613	bool "ISA-style bus support on modern systems" if EXPERT
2614	select ISA_BUS_API
2615	help
2616	  Enables ISA-style drivers on modern systems. This is necessary to
2617	  support PC/104 devices on X86_64 platforms.
2618
2619	  If unsure, say N.
2620
2621# x86_64 have no ISA slots, but can have ISA-style DMA.
2622config ISA_DMA_API
2623	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2624	default y
2625	help
2626	  Enables ISA-style DMA support for devices requiring such controllers.
2627	  If unsure, say Y.
2628
2629if X86_32
2630
2631config ISA
2632	bool "ISA support"
2633	---help---
2634	  Find out whether you have ISA slots on your motherboard.  ISA is the
2635	  name of a bus system, i.e. the way the CPU talks to the other stuff
2636	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2637	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2638	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2639
2640config EISA
2641	bool "EISA support"
2642	depends on ISA
2643	---help---
2644	  The Extended Industry Standard Architecture (EISA) bus was
2645	  developed as an open alternative to the IBM MicroChannel bus.
2646
2647	  The EISA bus provided some of the features of the IBM MicroChannel
2648	  bus while maintaining backward compatibility with cards made for
2649	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2650	  1995 when it was made obsolete by the PCI bus.
2651
2652	  Say Y here if you are building a kernel for an EISA-based machine.
2653
2654	  Otherwise, say N.
2655
2656source "drivers/eisa/Kconfig"
2657
2658config SCx200
2659	tristate "NatSemi SCx200 support"
2660	---help---
2661	  This provides basic support for National Semiconductor's
2662	  (now AMD's) Geode processors.  The driver probes for the
2663	  PCI-IDs of several on-chip devices, so its a good dependency
2664	  for other scx200_* drivers.
2665
2666	  If compiled as a module, the driver is named scx200.
2667
2668config SCx200HR_TIMER
2669	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2670	depends on SCx200
2671	default y
2672	---help---
2673	  This driver provides a clocksource built upon the on-chip
2674	  27MHz high-resolution timer.  Its also a workaround for
2675	  NSC Geode SC-1100's buggy TSC, which loses time when the
2676	  processor goes idle (as is done by the scheduler).  The
2677	  other workaround is idle=poll boot option.
2678
2679config OLPC
2680	bool "One Laptop Per Child support"
2681	depends on !X86_PAE
2682	select GPIOLIB
2683	select OF
2684	select OF_PROMTREE
2685	select IRQ_DOMAIN
2686	---help---
2687	  Add support for detecting the unique features of the OLPC
2688	  XO hardware.
2689
2690config OLPC_XO1_PM
2691	bool "OLPC XO-1 Power Management"
2692	depends on OLPC && MFD_CS5535 && PM_SLEEP
2693	select MFD_CORE
2694	---help---
2695	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2696
2697config OLPC_XO1_RTC
2698	bool "OLPC XO-1 Real Time Clock"
2699	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2700	---help---
2701	  Add support for the XO-1 real time clock, which can be used as a
2702	  programmable wakeup source.
2703
2704config OLPC_XO1_SCI
2705	bool "OLPC XO-1 SCI extras"
2706	depends on OLPC && OLPC_XO1_PM
2707	depends on INPUT=y
2708	select POWER_SUPPLY
2709	select GPIO_CS5535
2710	select MFD_CORE
2711	---help---
2712	  Add support for SCI-based features of the OLPC XO-1 laptop:
2713	   - EC-driven system wakeups
2714	   - Power button
2715	   - Ebook switch
2716	   - Lid switch
2717	   - AC adapter status updates
2718	   - Battery status updates
2719
2720config OLPC_XO15_SCI
2721	bool "OLPC XO-1.5 SCI extras"
2722	depends on OLPC && ACPI
2723	select POWER_SUPPLY
2724	---help---
2725	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2726	   - EC-driven system wakeups
2727	   - AC adapter status updates
2728	   - Battery status updates
2729
2730config ALIX
2731	bool "PCEngines ALIX System Support (LED setup)"
2732	select GPIOLIB
2733	---help---
2734	  This option enables system support for the PCEngines ALIX.
2735	  At present this just sets up LEDs for GPIO control on
2736	  ALIX2/3/6 boards.  However, other system specific setup should
2737	  get added here.
2738
2739	  Note: You must still enable the drivers for GPIO and LED support
2740	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2741
2742	  Note: You have to set alix.force=1 for boards with Award BIOS.
2743
2744config NET5501
2745	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2746	select GPIOLIB
2747	---help---
2748	  This option enables system support for the Soekris Engineering net5501.
2749
2750config GEOS
2751	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2752	select GPIOLIB
2753	depends on DMI
2754	---help---
2755	  This option enables system support for the Traverse Technologies GEOS.
2756
2757config TS5500
2758	bool "Technologic Systems TS-5500 platform support"
2759	depends on MELAN
2760	select CHECK_SIGNATURE
2761	select NEW_LEDS
2762	select LEDS_CLASS
2763	---help---
2764	  This option enables system support for the Technologic Systems TS-5500.
2765
2766endif # X86_32
2767
2768config AMD_NB
2769	def_bool y
2770	depends on CPU_SUP_AMD && PCI
2771
2772source "drivers/pcmcia/Kconfig"
2773
2774config RAPIDIO
2775	tristate "RapidIO support"
2776	depends on PCI
2777	default n
2778	help
2779	  If enabled this option will include drivers and the core
2780	  infrastructure code to support RapidIO interconnect devices.
2781
2782source "drivers/rapidio/Kconfig"
2783
2784config X86_SYSFB
2785	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2786	help
2787	  Firmwares often provide initial graphics framebuffers so the BIOS,
2788	  bootloader or kernel can show basic video-output during boot for
2789	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2790	  Extensions and EFI-framebuffers for this, which are mostly limited
2791	  to x86.
2792	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2793	  framebuffers so the new generic system-framebuffer drivers can be
2794	  used on x86. If the framebuffer is not compatible with the generic
2795	  modes, it is adverticed as fallback platform framebuffer so legacy
2796	  drivers like efifb, vesafb and uvesafb can pick it up.
2797	  If this option is not selected, all system framebuffers are always
2798	  marked as fallback platform framebuffers as usual.
2799
2800	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2801	  not be able to pick up generic system framebuffers if this option
2802	  is selected. You are highly encouraged to enable simplefb as
2803	  replacement if you select this option. simplefb can correctly deal
2804	  with generic system framebuffers. But you should still keep vesafb
2805	  and others enabled as fallback if a system framebuffer is
2806	  incompatible with simplefb.
2807
2808	  If unsure, say Y.
2809
2810endmenu
2811
2812
2813menu "Executable file formats / Emulations"
2814
2815source "fs/Kconfig.binfmt"
2816
2817config IA32_EMULATION
2818	bool "IA32 Emulation"
2819	depends on X86_64
2820	select ARCH_WANT_OLD_COMPAT_IPC
2821	select BINFMT_ELF
2822	select COMPAT_BINFMT_ELF
2823	select COMPAT_OLD_SIGACTION
2824	---help---
2825	  Include code to run legacy 32-bit programs under a
2826	  64-bit kernel. You should likely turn this on, unless you're
2827	  100% sure that you don't have any 32-bit programs left.
2828
2829config IA32_AOUT
2830	tristate "IA32 a.out support"
2831	depends on IA32_EMULATION
2832	---help---
2833	  Support old a.out binaries in the 32bit emulation.
2834
2835config X86_X32
2836	bool "x32 ABI for 64-bit mode"
2837	depends on X86_64
2838	---help---
2839	  Include code to run binaries for the x32 native 32-bit ABI
2840	  for 64-bit processors.  An x32 process gets access to the
2841	  full 64-bit register file and wide data path while leaving
2842	  pointers at 32 bits for smaller memory footprint.
2843
2844	  You will need a recent binutils (2.22 or later) with
2845	  elf32_x86_64 support enabled to compile a kernel with this
2846	  option set.
2847
2848config COMPAT_32
2849	def_bool y
2850	depends on IA32_EMULATION || X86_32
2851	select HAVE_UID16
2852	select OLD_SIGSUSPEND3
2853
2854config COMPAT
2855	def_bool y
2856	depends on IA32_EMULATION || X86_X32
2857
2858if COMPAT
2859config COMPAT_FOR_U64_ALIGNMENT
2860	def_bool y
2861
2862config SYSVIPC_COMPAT
2863	def_bool y
2864	depends on SYSVIPC
2865endif
2866
2867endmenu
2868
2869
2870config HAVE_ATOMIC_IOMAP
2871	def_bool y
2872	depends on X86_32
2873
2874config X86_DEV_DMA_OPS
2875	bool
2876	depends on X86_64 || STA2X11
2877
2878config X86_DMA_REMAP
2879	bool
2880	depends on STA2X11
2881
2882config HAVE_GENERIC_GUP
2883	def_bool y
2884
2885source "net/Kconfig"
2886
2887source "drivers/Kconfig"
2888
2889source "drivers/firmware/Kconfig"
2890
2891source "fs/Kconfig"
2892
2893source "arch/x86/Kconfig.debug"
2894
2895source "security/Kconfig"
2896
2897source "crypto/Kconfig"
2898
2899source "arch/x86/kvm/Kconfig"
2900
2901source "lib/Kconfig"
2902