xref: /openbmc/linux/arch/x86/Kconfig (revision ef833eab)
1# Select 32 or 64 bit
2config 64BIT
3	bool "64-bit kernel" if ARCH = "x86"
4	default ARCH != "i386"
5	---help---
6	  Say yes to build a 64-bit kernel - formerly known as x86_64
7	  Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
10	def_bool y
11	depends on !64BIT
12	# Options that are inherently 32-bit kernel only:
13	select ARCH_WANT_IPC_PARSE_VERSION
14	select CLKSRC_I8253
15	select CLONE_BACKWARDS
16	select HAVE_AOUT
17	select HAVE_GENERIC_DMA_COHERENT
18	select MODULES_USE_ELF_REL
19	select OLD_SIGACTION
20
21config X86_64
22	def_bool y
23	depends on 64BIT
24	# Options that are inherently 64-bit kernel only:
25	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
26	select ARCH_SUPPORTS_INT128
27	select ARCH_USE_CMPXCHG_LOCKREF
28	select HAVE_ARCH_SOFT_DIRTY
29	select MODULES_USE_ELF_RELA
30	select X86_DEV_DMA_OPS
31
32#
33# Arch settings
34#
35# ( Note that options that are marked 'if X86_64' could in principle be
36#   ported to 32-bit as well. )
37#
38config X86
39	def_bool y
40	#
41	# Note: keep this list sorted alphabetically
42	#
43	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
44	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
45	select ANON_INODES
46	select ARCH_CLOCKSOURCE_DATA
47	select ARCH_DISCARD_MEMBLOCK
48	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
49	select ARCH_HAS_DEBUG_VIRTUAL
50	select ARCH_HAS_DEVMEM_IS_ALLOWED
51	select ARCH_HAS_ELF_RANDOMIZE
52	select ARCH_HAS_FAST_MULTIPLIER
53	select ARCH_HAS_FORTIFY_SOURCE
54	select ARCH_HAS_GCOV_PROFILE_ALL
55	select ARCH_HAS_KCOV			if X86_64
56	select ARCH_HAS_PMEM_API		if X86_64
57	# Causing hangs/crashes, see the commit that added this change for details.
58	select ARCH_HAS_REFCOUNT		if BROKEN
59	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
60	select ARCH_HAS_SET_MEMORY
61	select ARCH_HAS_SG_CHAIN
62	select ARCH_HAS_STRICT_KERNEL_RWX
63	select ARCH_HAS_STRICT_MODULE_RWX
64	select ARCH_HAS_UBSAN_SANITIZE_ALL
65	select ARCH_HAS_ZONE_DEVICE		if X86_64
66	select ARCH_HAVE_NMI_SAFE_CMPXCHG
67	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
68	select ARCH_MIGHT_HAVE_PC_PARPORT
69	select ARCH_MIGHT_HAVE_PC_SERIO
70	select ARCH_SUPPORTS_ATOMIC_RMW
71	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
72	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
73	select ARCH_USE_BUILTIN_BSWAP
74	select ARCH_USE_QUEUED_RWLOCKS
75	select ARCH_USE_QUEUED_SPINLOCKS
76	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
77	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
78	select ARCH_WANTS_THP_SWAP		if X86_64
79	select BUILDTIME_EXTABLE_SORT
80	select CLKEVT_I8253
81	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
82	select CLOCKSOURCE_WATCHDOG
83	select DCACHE_WORD_ACCESS
84	select EDAC_ATOMIC_SCRUB
85	select EDAC_SUPPORT
86	select GENERIC_CLOCKEVENTS
87	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
88	select GENERIC_CLOCKEVENTS_MIN_ADJUST
89	select GENERIC_CMOS_UPDATE
90	select GENERIC_CPU_AUTOPROBE
91	select GENERIC_EARLY_IOREMAP
92	select GENERIC_FIND_FIRST_BIT
93	select GENERIC_IOMAP
94	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
95	select GENERIC_IRQ_MIGRATION		if SMP
96	select GENERIC_IRQ_PROBE
97	select GENERIC_IRQ_SHOW
98	select GENERIC_PENDING_IRQ		if SMP
99	select GENERIC_SMP_IDLE_THREAD
100	select GENERIC_STRNCPY_FROM_USER
101	select GENERIC_STRNLEN_USER
102	select GENERIC_TIME_VSYSCALL
103	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
104	select HAVE_ACPI_APEI			if ACPI
105	select HAVE_ACPI_APEI_NMI		if ACPI
106	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
107	select HAVE_ARCH_AUDITSYSCALL
108	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
109	select HAVE_ARCH_JUMP_LABEL
110	select HAVE_ARCH_KASAN			if X86_64 && SPARSEMEM_VMEMMAP
111	select HAVE_ARCH_KGDB
112	select HAVE_ARCH_KMEMCHECK
113	select HAVE_ARCH_MMAP_RND_BITS		if MMU
114	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
115	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
116	select HAVE_ARCH_SECCOMP_FILTER
117	select HAVE_ARCH_TRACEHOOK
118	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
119	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
120	select HAVE_ARCH_VMAP_STACK		if X86_64
121	select HAVE_ARCH_WITHIN_STACK_FRAMES
122	select HAVE_CC_STACKPROTECTOR
123	select HAVE_CMPXCHG_DOUBLE
124	select HAVE_CMPXCHG_LOCAL
125	select HAVE_CONTEXT_TRACKING		if X86_64
126	select HAVE_COPY_THREAD_TLS
127	select HAVE_C_RECORDMCOUNT
128	select HAVE_DEBUG_KMEMLEAK
129	select HAVE_DEBUG_STACKOVERFLOW
130	select HAVE_DMA_API_DEBUG
131	select HAVE_DMA_CONTIGUOUS
132	select HAVE_DYNAMIC_FTRACE
133	select HAVE_DYNAMIC_FTRACE_WITH_REGS
134	select HAVE_EBPF_JIT			if X86_64
135	select HAVE_EFFICIENT_UNALIGNED_ACCESS
136	select HAVE_EXIT_THREAD
137	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
138	select HAVE_FTRACE_MCOUNT_RECORD
139	select HAVE_FUNCTION_GRAPH_TRACER
140	select HAVE_FUNCTION_TRACER
141	select HAVE_GCC_PLUGINS
142	select HAVE_HW_BREAKPOINT
143	select HAVE_IDE
144	select HAVE_IOREMAP_PROT
145	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
146	select HAVE_IRQ_TIME_ACCOUNTING
147	select HAVE_KERNEL_BZIP2
148	select HAVE_KERNEL_GZIP
149	select HAVE_KERNEL_LZ4
150	select HAVE_KERNEL_LZMA
151	select HAVE_KERNEL_LZO
152	select HAVE_KERNEL_XZ
153	select HAVE_KPROBES
154	select HAVE_KPROBES_ON_FTRACE
155	select HAVE_KRETPROBES
156	select HAVE_KVM
157	select HAVE_LIVEPATCH			if X86_64
158	select HAVE_MEMBLOCK
159	select HAVE_MEMBLOCK_NODE_MAP
160	select HAVE_MIXED_BREAKPOINTS_REGS
161	select HAVE_MOD_ARCH_SPECIFIC
162	select HAVE_NMI
163	select HAVE_OPROFILE
164	select HAVE_OPTPROBES
165	select HAVE_PCSPKR_PLATFORM
166	select HAVE_PERF_EVENTS
167	select HAVE_PERF_EVENTS_NMI
168	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
169	select HAVE_PERF_REGS
170	select HAVE_PERF_USER_STACK_DUMP
171	select HAVE_RCU_TABLE_FREE
172	select HAVE_REGS_AND_STACK_ACCESS_API
173	select HAVE_RELIABLE_STACKTRACE		if X86_64 && FRAME_POINTER_UNWINDER && STACK_VALIDATION
174	select HAVE_STACK_VALIDATION		if X86_64
175	select HAVE_SYSCALL_TRACEPOINTS
176	select HAVE_UNSTABLE_SCHED_CLOCK
177	select HAVE_USER_RETURN_NOTIFIER
178	select IRQ_FORCED_THREADING
179	select PCI_LOCKLESS_CONFIG
180	select PERF_EVENTS
181	select RTC_LIB
182	select RTC_MC146818_LIB
183	select SPARSE_IRQ
184	select SRCU
185	select SYSCTL_EXCEPTION_TRACE
186	select THREAD_INFO_IN_TASK
187	select USER_STACKTRACE_SUPPORT
188	select VIRT_TO_BUS
189	select X86_FEATURE_NAMES		if PROC_FS
190
191config INSTRUCTION_DECODER
192	def_bool y
193	depends on KPROBES || PERF_EVENTS || UPROBES
194
195config OUTPUT_FORMAT
196	string
197	default "elf32-i386" if X86_32
198	default "elf64-x86-64" if X86_64
199
200config ARCH_DEFCONFIG
201	string
202	default "arch/x86/configs/i386_defconfig" if X86_32
203	default "arch/x86/configs/x86_64_defconfig" if X86_64
204
205config LOCKDEP_SUPPORT
206	def_bool y
207
208config STACKTRACE_SUPPORT
209	def_bool y
210
211config MMU
212	def_bool y
213
214config ARCH_MMAP_RND_BITS_MIN
215	default 28 if 64BIT
216	default 8
217
218config ARCH_MMAP_RND_BITS_MAX
219	default 32 if 64BIT
220	default 16
221
222config ARCH_MMAP_RND_COMPAT_BITS_MIN
223	default 8
224
225config ARCH_MMAP_RND_COMPAT_BITS_MAX
226	default 16
227
228config SBUS
229	bool
230
231config NEED_DMA_MAP_STATE
232	def_bool y
233	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
234
235config NEED_SG_DMA_LENGTH
236	def_bool y
237
238config GENERIC_ISA_DMA
239	def_bool y
240	depends on ISA_DMA_API
241
242config GENERIC_BUG
243	def_bool y
244	depends on BUG
245	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
246
247config GENERIC_BUG_RELATIVE_POINTERS
248	bool
249
250config GENERIC_HWEIGHT
251	def_bool y
252
253config ARCH_MAY_HAVE_PC_FDC
254	def_bool y
255	depends on ISA_DMA_API
256
257config RWSEM_XCHGADD_ALGORITHM
258	def_bool y
259
260config GENERIC_CALIBRATE_DELAY
261	def_bool y
262
263config ARCH_HAS_CPU_RELAX
264	def_bool y
265
266config ARCH_HAS_CACHE_LINE_SIZE
267	def_bool y
268
269config HAVE_SETUP_PER_CPU_AREA
270	def_bool y
271
272config NEED_PER_CPU_EMBED_FIRST_CHUNK
273	def_bool y
274
275config NEED_PER_CPU_PAGE_FIRST_CHUNK
276	def_bool y
277
278config ARCH_HIBERNATION_POSSIBLE
279	def_bool y
280
281config ARCH_SUSPEND_POSSIBLE
282	def_bool y
283
284config ARCH_WANT_HUGE_PMD_SHARE
285	def_bool y
286
287config ARCH_WANT_GENERAL_HUGETLB
288	def_bool y
289
290config ZONE_DMA32
291	def_bool y if X86_64
292
293config AUDIT_ARCH
294	def_bool y if X86_64
295
296config ARCH_SUPPORTS_OPTIMIZED_INLINING
297	def_bool y
298
299config ARCH_SUPPORTS_DEBUG_PAGEALLOC
300	def_bool y
301
302config KASAN_SHADOW_OFFSET
303	hex
304	depends on KASAN
305	default 0xdff8000000000000 if X86_5LEVEL
306	default 0xdffffc0000000000
307
308config HAVE_INTEL_TXT
309	def_bool y
310	depends on INTEL_IOMMU && ACPI
311
312config X86_32_SMP
313	def_bool y
314	depends on X86_32 && SMP
315
316config X86_64_SMP
317	def_bool y
318	depends on X86_64 && SMP
319
320config X86_32_LAZY_GS
321	def_bool y
322	depends on X86_32 && !CC_STACKPROTECTOR
323
324config ARCH_SUPPORTS_UPROBES
325	def_bool y
326
327config FIX_EARLYCON_MEM
328	def_bool y
329
330config PGTABLE_LEVELS
331	int
332	default 5 if X86_5LEVEL
333	default 4 if X86_64
334	default 3 if X86_PAE
335	default 2
336
337source "init/Kconfig"
338source "kernel/Kconfig.freezer"
339
340menu "Processor type and features"
341
342config ZONE_DMA
343	bool "DMA memory allocation support" if EXPERT
344	default y
345	help
346	  DMA memory allocation support allows devices with less than 32-bit
347	  addressing to allocate within the first 16MB of address space.
348	  Disable if no such devices will be used.
349
350	  If unsure, say Y.
351
352config SMP
353	bool "Symmetric multi-processing support"
354	---help---
355	  This enables support for systems with more than one CPU. If you have
356	  a system with only one CPU, say N. If you have a system with more
357	  than one CPU, say Y.
358
359	  If you say N here, the kernel will run on uni- and multiprocessor
360	  machines, but will use only one CPU of a multiprocessor machine. If
361	  you say Y here, the kernel will run on many, but not all,
362	  uniprocessor machines. On a uniprocessor machine, the kernel
363	  will run faster if you say N here.
364
365	  Note that if you say Y here and choose architecture "586" or
366	  "Pentium" under "Processor family", the kernel will not work on 486
367	  architectures. Similarly, multiprocessor kernels for the "PPro"
368	  architecture may not work on all Pentium based boards.
369
370	  People using multiprocessor machines who say Y here should also say
371	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
372	  Management" code will be disabled if you say Y here.
373
374	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
375	  <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
376	  <http://www.tldp.org/docs.html#howto>.
377
378	  If you don't know what to do here, say N.
379
380config X86_FEATURE_NAMES
381	bool "Processor feature human-readable names" if EMBEDDED
382	default y
383	---help---
384	  This option compiles in a table of x86 feature bits and corresponding
385	  names.  This is required to support /proc/cpuinfo and a few kernel
386	  messages.  You can disable this to save space, at the expense of
387	  making those few kernel messages show numeric feature bits instead.
388
389	  If in doubt, say Y.
390
391config X86_FAST_FEATURE_TESTS
392	bool "Fast CPU feature tests" if EMBEDDED
393	default y
394	---help---
395	  Some fast-paths in the kernel depend on the capabilities of the CPU.
396	  Say Y here for the kernel to patch in the appropriate code at runtime
397	  based on the capabilities of the CPU. The infrastructure for patching
398	  code at runtime takes up some additional space; space-constrained
399	  embedded systems may wish to say N here to produce smaller, slightly
400	  slower code.
401
402config X86_X2APIC
403	bool "Support x2apic"
404	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
405	---help---
406	  This enables x2apic support on CPUs that have this feature.
407
408	  This allows 32-bit apic IDs (so it can support very large systems),
409	  and accesses the local apic via MSRs not via mmio.
410
411	  If you don't know what to do here, say N.
412
413config X86_MPPARSE
414	bool "Enable MPS table" if ACPI || SFI
415	default y
416	depends on X86_LOCAL_APIC
417	---help---
418	  For old smp systems that do not have proper acpi support. Newer systems
419	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
420
421config X86_BIGSMP
422	bool "Support for big SMP systems with more than 8 CPUs"
423	depends on X86_32 && SMP
424	---help---
425	  This option is needed for the systems that have more than 8 CPUs
426
427config GOLDFISH
428       def_bool y
429       depends on X86_GOLDFISH
430
431config INTEL_RDT
432	bool "Intel Resource Director Technology support"
433	default n
434	depends on X86 && CPU_SUP_INTEL
435	select KERNFS
436	help
437	  Select to enable resource allocation and monitoring which are
438	  sub-features of Intel Resource Director Technology(RDT). More
439	  information about RDT can be found in the Intel x86
440	  Architecture Software Developer Manual.
441
442	  Say N if unsure.
443
444if X86_32
445config X86_EXTENDED_PLATFORM
446	bool "Support for extended (non-PC) x86 platforms"
447	default y
448	---help---
449	  If you disable this option then the kernel will only support
450	  standard PC platforms. (which covers the vast majority of
451	  systems out there.)
452
453	  If you enable this option then you'll be able to select support
454	  for the following (non-PC) 32 bit x86 platforms:
455		Goldfish (Android emulator)
456		AMD Elan
457		RDC R-321x SoC
458		SGI 320/540 (Visual Workstation)
459		STA2X11-based (e.g. Northville)
460		Moorestown MID devices
461
462	  If you have one of these systems, or if you want to build a
463	  generic distribution kernel, say Y here - otherwise say N.
464endif
465
466if X86_64
467config X86_EXTENDED_PLATFORM
468	bool "Support for extended (non-PC) x86 platforms"
469	default y
470	---help---
471	  If you disable this option then the kernel will only support
472	  standard PC platforms. (which covers the vast majority of
473	  systems out there.)
474
475	  If you enable this option then you'll be able to select support
476	  for the following (non-PC) 64 bit x86 platforms:
477		Numascale NumaChip
478		ScaleMP vSMP
479		SGI Ultraviolet
480
481	  If you have one of these systems, or if you want to build a
482	  generic distribution kernel, say Y here - otherwise say N.
483endif
484# This is an alphabetically sorted list of 64 bit extended platforms
485# Please maintain the alphabetic order if and when there are additions
486config X86_NUMACHIP
487	bool "Numascale NumaChip"
488	depends on X86_64
489	depends on X86_EXTENDED_PLATFORM
490	depends on NUMA
491	depends on SMP
492	depends on X86_X2APIC
493	depends on PCI_MMCONFIG
494	---help---
495	  Adds support for Numascale NumaChip large-SMP systems. Needed to
496	  enable more than ~168 cores.
497	  If you don't have one of these, you should say N here.
498
499config X86_VSMP
500	bool "ScaleMP vSMP"
501	select HYPERVISOR_GUEST
502	select PARAVIRT
503	depends on X86_64 && PCI
504	depends on X86_EXTENDED_PLATFORM
505	depends on SMP
506	---help---
507	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
508	  supposed to run on these EM64T-based machines.  Only choose this option
509	  if you have one of these machines.
510
511config X86_UV
512	bool "SGI Ultraviolet"
513	depends on X86_64
514	depends on X86_EXTENDED_PLATFORM
515	depends on NUMA
516	depends on EFI
517	depends on X86_X2APIC
518	depends on PCI
519	---help---
520	  This option is needed in order to support SGI Ultraviolet systems.
521	  If you don't have one of these, you should say N here.
522
523# Following is an alphabetically sorted list of 32 bit extended platforms
524# Please maintain the alphabetic order if and when there are additions
525
526config X86_GOLDFISH
527       bool "Goldfish (Virtual Platform)"
528       depends on X86_EXTENDED_PLATFORM
529       ---help---
530	 Enable support for the Goldfish virtual platform used primarily
531	 for Android development. Unless you are building for the Android
532	 Goldfish emulator say N here.
533
534config X86_INTEL_CE
535	bool "CE4100 TV platform"
536	depends on PCI
537	depends on PCI_GODIRECT
538	depends on X86_IO_APIC
539	depends on X86_32
540	depends on X86_EXTENDED_PLATFORM
541	select X86_REBOOTFIXUPS
542	select OF
543	select OF_EARLY_FLATTREE
544	---help---
545	  Select for the Intel CE media processor (CE4100) SOC.
546	  This option compiles in support for the CE4100 SOC for settop
547	  boxes and media devices.
548
549config X86_INTEL_MID
550	bool "Intel MID platform support"
551	depends on X86_EXTENDED_PLATFORM
552	depends on X86_PLATFORM_DEVICES
553	depends on PCI
554	depends on X86_64 || (PCI_GOANY && X86_32)
555	depends on X86_IO_APIC
556	select SFI
557	select I2C
558	select DW_APB_TIMER
559	select APB_TIMER
560	select INTEL_SCU_IPC
561	select MFD_INTEL_MSIC
562	---help---
563	  Select to build a kernel capable of supporting Intel MID (Mobile
564	  Internet Device) platform systems which do not have the PCI legacy
565	  interfaces. If you are building for a PC class system say N here.
566
567	  Intel MID platforms are based on an Intel processor and chipset which
568	  consume less power than most of the x86 derivatives.
569
570config X86_INTEL_QUARK
571	bool "Intel Quark platform support"
572	depends on X86_32
573	depends on X86_EXTENDED_PLATFORM
574	depends on X86_PLATFORM_DEVICES
575	depends on X86_TSC
576	depends on PCI
577	depends on PCI_GOANY
578	depends on X86_IO_APIC
579	select IOSF_MBI
580	select INTEL_IMR
581	select COMMON_CLK
582	---help---
583	  Select to include support for Quark X1000 SoC.
584	  Say Y here if you have a Quark based system such as the Arduino
585	  compatible Intel Galileo.
586
587config X86_INTEL_LPSS
588	bool "Intel Low Power Subsystem Support"
589	depends on X86 && ACPI
590	select COMMON_CLK
591	select PINCTRL
592	select IOSF_MBI
593	---help---
594	  Select to build support for Intel Low Power Subsystem such as
595	  found on Intel Lynxpoint PCH. Selecting this option enables
596	  things like clock tree (common clock framework) and pincontrol
597	  which are needed by the LPSS peripheral drivers.
598
599config X86_AMD_PLATFORM_DEVICE
600	bool "AMD ACPI2Platform devices support"
601	depends on ACPI
602	select COMMON_CLK
603	select PINCTRL
604	---help---
605	  Select to interpret AMD specific ACPI device to platform device
606	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
607	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
608	  implemented under PINCTRL subsystem.
609
610config IOSF_MBI
611	tristate "Intel SoC IOSF Sideband support for SoC platforms"
612	depends on PCI
613	---help---
614	  This option enables sideband register access support for Intel SoC
615	  platforms. On these platforms the IOSF sideband is used in lieu of
616	  MSR's for some register accesses, mostly but not limited to thermal
617	  and power. Drivers may query the availability of this device to
618	  determine if they need the sideband in order to work on these
619	  platforms. The sideband is available on the following SoC products.
620	  This list is not meant to be exclusive.
621	   - BayTrail
622	   - Braswell
623	   - Quark
624
625	  You should say Y if you are running a kernel on one of these SoC's.
626
627config IOSF_MBI_DEBUG
628	bool "Enable IOSF sideband access through debugfs"
629	depends on IOSF_MBI && DEBUG_FS
630	---help---
631	  Select this option to expose the IOSF sideband access registers (MCR,
632	  MDR, MCRX) through debugfs to write and read register information from
633	  different units on the SoC. This is most useful for obtaining device
634	  state information for debug and analysis. As this is a general access
635	  mechanism, users of this option would have specific knowledge of the
636	  device they want to access.
637
638	  If you don't require the option or are in doubt, say N.
639
640config X86_RDC321X
641	bool "RDC R-321x SoC"
642	depends on X86_32
643	depends on X86_EXTENDED_PLATFORM
644	select M486
645	select X86_REBOOTFIXUPS
646	---help---
647	  This option is needed for RDC R-321x system-on-chip, also known
648	  as R-8610-(G).
649	  If you don't have one of these chips, you should say N here.
650
651config X86_32_NON_STANDARD
652	bool "Support non-standard 32-bit SMP architectures"
653	depends on X86_32 && SMP
654	depends on X86_EXTENDED_PLATFORM
655	---help---
656	  This option compiles in the bigsmp and STA2X11 default
657	  subarchitectures.  It is intended for a generic binary
658	  kernel. If you select them all, kernel will probe it one by
659	  one and will fallback to default.
660
661# Alphabetically sorted list of Non standard 32 bit platforms
662
663config X86_SUPPORTS_MEMORY_FAILURE
664	def_bool y
665	# MCE code calls memory_failure():
666	depends on X86_MCE
667	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
668	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
669	depends on X86_64 || !SPARSEMEM
670	select ARCH_SUPPORTS_MEMORY_FAILURE
671
672config STA2X11
673	bool "STA2X11 Companion Chip Support"
674	depends on X86_32_NON_STANDARD && PCI
675	select X86_DEV_DMA_OPS
676	select X86_DMA_REMAP
677	select SWIOTLB
678	select MFD_STA2X11
679	select GPIOLIB
680	default n
681	---help---
682	  This adds support for boards based on the STA2X11 IO-Hub,
683	  a.k.a. "ConneXt". The chip is used in place of the standard
684	  PC chipset, so all "standard" peripherals are missing. If this
685	  option is selected the kernel will still be able to boot on
686	  standard PC machines.
687
688config X86_32_IRIS
689	tristate "Eurobraille/Iris poweroff module"
690	depends on X86_32
691	---help---
692	  The Iris machines from EuroBraille do not have APM or ACPI support
693	  to shut themselves down properly.  A special I/O sequence is
694	  needed to do so, which is what this module does at
695	  kernel shutdown.
696
697	  This is only for Iris machines from EuroBraille.
698
699	  If unused, say N.
700
701config SCHED_OMIT_FRAME_POINTER
702	def_bool y
703	prompt "Single-depth WCHAN output"
704	depends on X86
705	---help---
706	  Calculate simpler /proc/<PID>/wchan values. If this option
707	  is disabled then wchan values will recurse back to the
708	  caller function. This provides more accurate wchan values,
709	  at the expense of slightly more scheduling overhead.
710
711	  If in doubt, say "Y".
712
713menuconfig HYPERVISOR_GUEST
714	bool "Linux guest support"
715	---help---
716	  Say Y here to enable options for running Linux under various hyper-
717	  visors. This option enables basic hypervisor detection and platform
718	  setup.
719
720	  If you say N, all options in this submenu will be skipped and
721	  disabled, and Linux guest support won't be built in.
722
723if HYPERVISOR_GUEST
724
725config PARAVIRT
726	bool "Enable paravirtualization code"
727	---help---
728	  This changes the kernel so it can modify itself when it is run
729	  under a hypervisor, potentially improving performance significantly
730	  over full virtualization.  However, when run without a hypervisor
731	  the kernel is theoretically slower and slightly larger.
732
733config PARAVIRT_DEBUG
734	bool "paravirt-ops debugging"
735	depends on PARAVIRT && DEBUG_KERNEL
736	---help---
737	  Enable to debug paravirt_ops internals.  Specifically, BUG if
738	  a paravirt_op is missing when it is called.
739
740config PARAVIRT_SPINLOCKS
741	bool "Paravirtualization layer for spinlocks"
742	depends on PARAVIRT && SMP
743	---help---
744	  Paravirtualized spinlocks allow a pvops backend to replace the
745	  spinlock implementation with something virtualization-friendly
746	  (for example, block the virtual CPU rather than spinning).
747
748	  It has a minimal impact on native kernels and gives a nice performance
749	  benefit on paravirtualized KVM / Xen kernels.
750
751	  If you are unsure how to answer this question, answer Y.
752
753config QUEUED_LOCK_STAT
754	bool "Paravirt queued spinlock statistics"
755	depends on PARAVIRT_SPINLOCKS && DEBUG_FS
756	---help---
757	  Enable the collection of statistical data on the slowpath
758	  behavior of paravirtualized queued spinlocks and report
759	  them on debugfs.
760
761source "arch/x86/xen/Kconfig"
762
763config KVM_GUEST
764	bool "KVM Guest support (including kvmclock)"
765	depends on PARAVIRT
766	select PARAVIRT_CLOCK
767	default y
768	---help---
769	  This option enables various optimizations for running under the KVM
770	  hypervisor. It includes a paravirtualized clock, so that instead
771	  of relying on a PIT (or probably other) emulation by the
772	  underlying device model, the host provides the guest with
773	  timing infrastructure such as time of day, and system time
774
775config KVM_DEBUG_FS
776	bool "Enable debug information for KVM Guests in debugfs"
777	depends on KVM_GUEST && DEBUG_FS
778	default n
779	---help---
780	  This option enables collection of various statistics for KVM guest.
781	  Statistics are displayed in debugfs filesystem. Enabling this option
782	  may incur significant overhead.
783
784config PARAVIRT_TIME_ACCOUNTING
785	bool "Paravirtual steal time accounting"
786	depends on PARAVIRT
787	default n
788	---help---
789	  Select this option to enable fine granularity task steal time
790	  accounting. Time spent executing other tasks in parallel with
791	  the current vCPU is discounted from the vCPU power. To account for
792	  that, there can be a small performance impact.
793
794	  If in doubt, say N here.
795
796config PARAVIRT_CLOCK
797	bool
798
799endif #HYPERVISOR_GUEST
800
801config NO_BOOTMEM
802	def_bool y
803
804source "arch/x86/Kconfig.cpu"
805
806config HPET_TIMER
807	def_bool X86_64
808	prompt "HPET Timer Support" if X86_32
809	---help---
810	  Use the IA-PC HPET (High Precision Event Timer) to manage
811	  time in preference to the PIT and RTC, if a HPET is
812	  present.
813	  HPET is the next generation timer replacing legacy 8254s.
814	  The HPET provides a stable time base on SMP
815	  systems, unlike the TSC, but it is more expensive to access,
816	  as it is off-chip.  The interface used is documented
817	  in the HPET spec, revision 1.
818
819	  You can safely choose Y here.  However, HPET will only be
820	  activated if the platform and the BIOS support this feature.
821	  Otherwise the 8254 will be used for timing services.
822
823	  Choose N to continue using the legacy 8254 timer.
824
825config HPET_EMULATE_RTC
826	def_bool y
827	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
828
829config APB_TIMER
830       def_bool y if X86_INTEL_MID
831       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
832       select DW_APB_TIMER
833       depends on X86_INTEL_MID && SFI
834       help
835         APB timer is the replacement for 8254, HPET on X86 MID platforms.
836         The APBT provides a stable time base on SMP
837         systems, unlike the TSC, but it is more expensive to access,
838         as it is off-chip. APB timers are always running regardless of CPU
839         C states, they are used as per CPU clockevent device when possible.
840
841# Mark as expert because too many people got it wrong.
842# The code disables itself when not needed.
843config DMI
844	default y
845	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
846	bool "Enable DMI scanning" if EXPERT
847	---help---
848	  Enabled scanning of DMI to identify machine quirks. Say Y
849	  here unless you have verified that your setup is not
850	  affected by entries in the DMI blacklist. Required by PNP
851	  BIOS code.
852
853config GART_IOMMU
854	bool "Old AMD GART IOMMU support"
855	select SWIOTLB
856	depends on X86_64 && PCI && AMD_NB
857	---help---
858	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
859	  GART based hardware IOMMUs.
860
861	  The GART supports full DMA access for devices with 32-bit access
862	  limitations, on systems with more than 3 GB. This is usually needed
863	  for USB, sound, many IDE/SATA chipsets and some other devices.
864
865	  Newer systems typically have a modern AMD IOMMU, supported via
866	  the CONFIG_AMD_IOMMU=y config option.
867
868	  In normal configurations this driver is only active when needed:
869	  there's more than 3 GB of memory and the system contains a
870	  32-bit limited device.
871
872	  If unsure, say Y.
873
874config CALGARY_IOMMU
875	bool "IBM Calgary IOMMU support"
876	select SWIOTLB
877	depends on X86_64 && PCI
878	---help---
879	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
880	  systems. Needed to run systems with more than 3GB of memory
881	  properly with 32-bit PCI devices that do not support DAC
882	  (Double Address Cycle). Calgary also supports bus level
883	  isolation, where all DMAs pass through the IOMMU.  This
884	  prevents them from going anywhere except their intended
885	  destination. This catches hard-to-find kernel bugs and
886	  mis-behaving drivers and devices that do not use the DMA-API
887	  properly to set up their DMA buffers.  The IOMMU can be
888	  turned off at boot time with the iommu=off parameter.
889	  Normally the kernel will make the right choice by itself.
890	  If unsure, say Y.
891
892config CALGARY_IOMMU_ENABLED_BY_DEFAULT
893	def_bool y
894	prompt "Should Calgary be enabled by default?"
895	depends on CALGARY_IOMMU
896	---help---
897	  Should Calgary be enabled by default? if you choose 'y', Calgary
898	  will be used (if it exists). If you choose 'n', Calgary will not be
899	  used even if it exists. If you choose 'n' and would like to use
900	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
901	  If unsure, say Y.
902
903# need this always selected by IOMMU for the VIA workaround
904config SWIOTLB
905	def_bool y if X86_64
906	---help---
907	  Support for software bounce buffers used on x86-64 systems
908	  which don't have a hardware IOMMU. Using this PCI devices
909	  which can only access 32-bits of memory can be used on systems
910	  with more than 3 GB of memory.
911	  If unsure, say Y.
912
913config IOMMU_HELPER
914	def_bool y
915	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
916
917config MAXSMP
918	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
919	depends on X86_64 && SMP && DEBUG_KERNEL
920	select CPUMASK_OFFSTACK
921	---help---
922	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
923	  If unsure, say N.
924
925config NR_CPUS
926	int "Maximum number of CPUs" if SMP && !MAXSMP
927	range 2 8 if SMP && X86_32 && !X86_BIGSMP
928	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
929	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
930	default "1" if !SMP
931	default "8192" if MAXSMP
932	default "32" if SMP && X86_BIGSMP
933	default "8" if SMP && X86_32
934	default "64" if SMP
935	---help---
936	  This allows you to specify the maximum number of CPUs which this
937	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
938	  supported value is 8192, otherwise the maximum value is 512.  The
939	  minimum value which makes sense is 2.
940
941	  This is purely to save memory - each supported CPU adds
942	  approximately eight kilobytes to the kernel image.
943
944config SCHED_SMT
945	bool "SMT (Hyperthreading) scheduler support"
946	depends on SMP
947	---help---
948	  SMT scheduler support improves the CPU scheduler's decision making
949	  when dealing with Intel Pentium 4 chips with HyperThreading at a
950	  cost of slightly increased overhead in some places. If unsure say
951	  N here.
952
953config SCHED_MC
954	def_bool y
955	prompt "Multi-core scheduler support"
956	depends on SMP
957	---help---
958	  Multi-core scheduler support improves the CPU scheduler's decision
959	  making when dealing with multi-core CPU chips at a cost of slightly
960	  increased overhead in some places. If unsure say N here.
961
962config SCHED_MC_PRIO
963	bool "CPU core priorities scheduler support"
964	depends on SCHED_MC && CPU_SUP_INTEL
965	select X86_INTEL_PSTATE
966	select CPU_FREQ
967	default y
968	---help---
969	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
970	  core ordering determined at manufacturing time, which allows
971	  certain cores to reach higher turbo frequencies (when running
972	  single threaded workloads) than others.
973
974	  Enabling this kernel feature teaches the scheduler about
975	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
976	  scheduler's CPU selection logic accordingly, so that higher
977	  overall system performance can be achieved.
978
979	  This feature will have no effect on CPUs without this feature.
980
981	  If unsure say Y here.
982
983source "kernel/Kconfig.preempt"
984
985config UP_LATE_INIT
986       def_bool y
987       depends on !SMP && X86_LOCAL_APIC
988
989config X86_UP_APIC
990	bool "Local APIC support on uniprocessors" if !PCI_MSI
991	default PCI_MSI
992	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
993	---help---
994	  A local APIC (Advanced Programmable Interrupt Controller) is an
995	  integrated interrupt controller in the CPU. If you have a single-CPU
996	  system which has a processor with a local APIC, you can say Y here to
997	  enable and use it. If you say Y here even though your machine doesn't
998	  have a local APIC, then the kernel will still run with no slowdown at
999	  all. The local APIC supports CPU-generated self-interrupts (timer,
1000	  performance counters), and the NMI watchdog which detects hard
1001	  lockups.
1002
1003config X86_UP_IOAPIC
1004	bool "IO-APIC support on uniprocessors"
1005	depends on X86_UP_APIC
1006	---help---
1007	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1008	  SMP-capable replacement for PC-style interrupt controllers. Most
1009	  SMP systems and many recent uniprocessor systems have one.
1010
1011	  If you have a single-CPU system with an IO-APIC, you can say Y here
1012	  to use it. If you say Y here even though your machine doesn't have
1013	  an IO-APIC, then the kernel will still run with no slowdown at all.
1014
1015config X86_LOCAL_APIC
1016	def_bool y
1017	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1018	select IRQ_DOMAIN_HIERARCHY
1019	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1020
1021config X86_IO_APIC
1022	def_bool y
1023	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1024
1025config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1026	bool "Reroute for broken boot IRQs"
1027	depends on X86_IO_APIC
1028	---help---
1029	  This option enables a workaround that fixes a source of
1030	  spurious interrupts. This is recommended when threaded
1031	  interrupt handling is used on systems where the generation of
1032	  superfluous "boot interrupts" cannot be disabled.
1033
1034	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1035	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1036	  kernel does during interrupt handling). On chipsets where this
1037	  boot IRQ generation cannot be disabled, this workaround keeps
1038	  the original IRQ line masked so that only the equivalent "boot
1039	  IRQ" is delivered to the CPUs. The workaround also tells the
1040	  kernel to set up the IRQ handler on the boot IRQ line. In this
1041	  way only one interrupt is delivered to the kernel. Otherwise
1042	  the spurious second interrupt may cause the kernel to bring
1043	  down (vital) interrupt lines.
1044
1045	  Only affects "broken" chipsets. Interrupt sharing may be
1046	  increased on these systems.
1047
1048config X86_MCE
1049	bool "Machine Check / overheating reporting"
1050	select GENERIC_ALLOCATOR
1051	default y
1052	---help---
1053	  Machine Check support allows the processor to notify the
1054	  kernel if it detects a problem (e.g. overheating, data corruption).
1055	  The action the kernel takes depends on the severity of the problem,
1056	  ranging from warning messages to halting the machine.
1057
1058config X86_MCELOG_LEGACY
1059	bool "Support for deprecated /dev/mcelog character device"
1060	depends on X86_MCE
1061	---help---
1062	  Enable support for /dev/mcelog which is needed by the old mcelog
1063	  userspace logging daemon. Consider switching to the new generation
1064	  rasdaemon solution.
1065
1066config X86_MCE_INTEL
1067	def_bool y
1068	prompt "Intel MCE features"
1069	depends on X86_MCE && X86_LOCAL_APIC
1070	---help---
1071	   Additional support for intel specific MCE features such as
1072	   the thermal monitor.
1073
1074config X86_MCE_AMD
1075	def_bool y
1076	prompt "AMD MCE features"
1077	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1078	---help---
1079	   Additional support for AMD specific MCE features such as
1080	   the DRAM Error Threshold.
1081
1082config X86_ANCIENT_MCE
1083	bool "Support for old Pentium 5 / WinChip machine checks"
1084	depends on X86_32 && X86_MCE
1085	---help---
1086	  Include support for machine check handling on old Pentium 5 or WinChip
1087	  systems. These typically need to be enabled explicitly on the command
1088	  line.
1089
1090config X86_MCE_THRESHOLD
1091	depends on X86_MCE_AMD || X86_MCE_INTEL
1092	def_bool y
1093
1094config X86_MCE_INJECT
1095	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1096	tristate "Machine check injector support"
1097	---help---
1098	  Provide support for injecting machine checks for testing purposes.
1099	  If you don't know what a machine check is and you don't do kernel
1100	  QA it is safe to say n.
1101
1102config X86_THERMAL_VECTOR
1103	def_bool y
1104	depends on X86_MCE_INTEL
1105
1106source "arch/x86/events/Kconfig"
1107
1108config X86_LEGACY_VM86
1109	bool "Legacy VM86 support"
1110	default n
1111	depends on X86_32
1112	---help---
1113	  This option allows user programs to put the CPU into V8086
1114	  mode, which is an 80286-era approximation of 16-bit real mode.
1115
1116	  Some very old versions of X and/or vbetool require this option
1117	  for user mode setting.  Similarly, DOSEMU will use it if
1118	  available to accelerate real mode DOS programs.  However, any
1119	  recent version of DOSEMU, X, or vbetool should be fully
1120	  functional even without kernel VM86 support, as they will all
1121	  fall back to software emulation. Nevertheless, if you are using
1122	  a 16-bit DOS program where 16-bit performance matters, vm86
1123	  mode might be faster than emulation and you might want to
1124	  enable this option.
1125
1126	  Note that any app that works on a 64-bit kernel is unlikely to
1127	  need this option, as 64-bit kernels don't, and can't, support
1128	  V8086 mode. This option is also unrelated to 16-bit protected
1129	  mode and is not needed to run most 16-bit programs under Wine.
1130
1131	  Enabling this option increases the complexity of the kernel
1132	  and slows down exception handling a tiny bit.
1133
1134	  If unsure, say N here.
1135
1136config VM86
1137       bool
1138       default X86_LEGACY_VM86
1139
1140config X86_16BIT
1141	bool "Enable support for 16-bit segments" if EXPERT
1142	default y
1143	depends on MODIFY_LDT_SYSCALL
1144	---help---
1145	  This option is required by programs like Wine to run 16-bit
1146	  protected mode legacy code on x86 processors.  Disabling
1147	  this option saves about 300 bytes on i386, or around 6K text
1148	  plus 16K runtime memory on x86-64,
1149
1150config X86_ESPFIX32
1151	def_bool y
1152	depends on X86_16BIT && X86_32
1153
1154config X86_ESPFIX64
1155	def_bool y
1156	depends on X86_16BIT && X86_64
1157
1158config X86_VSYSCALL_EMULATION
1159       bool "Enable vsyscall emulation" if EXPERT
1160       default y
1161       depends on X86_64
1162       ---help---
1163	 This enables emulation of the legacy vsyscall page.  Disabling
1164	 it is roughly equivalent to booting with vsyscall=none, except
1165	 that it will also disable the helpful warning if a program
1166	 tries to use a vsyscall.  With this option set to N, offending
1167	 programs will just segfault, citing addresses of the form
1168	 0xffffffffff600?00.
1169
1170	 This option is required by many programs built before 2013, and
1171	 care should be used even with newer programs if set to N.
1172
1173	 Disabling this option saves about 7K of kernel size and
1174	 possibly 4K of additional runtime pagetable memory.
1175
1176config TOSHIBA
1177	tristate "Toshiba Laptop support"
1178	depends on X86_32
1179	---help---
1180	  This adds a driver to safely access the System Management Mode of
1181	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1182	  not work on models with a Phoenix BIOS. The System Management Mode
1183	  is used to set the BIOS and power saving options on Toshiba portables.
1184
1185	  For information on utilities to make use of this driver see the
1186	  Toshiba Linux utilities web site at:
1187	  <http://www.buzzard.org.uk/toshiba/>.
1188
1189	  Say Y if you intend to run this kernel on a Toshiba portable.
1190	  Say N otherwise.
1191
1192config I8K
1193	tristate "Dell i8k legacy laptop support"
1194	select HWMON
1195	select SENSORS_DELL_SMM
1196	---help---
1197	  This option enables legacy /proc/i8k userspace interface in hwmon
1198	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1199	  temperature and allows controlling fan speeds of Dell laptops via
1200	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1201	  it reports also power and hotkey status. For fan speed control is
1202	  needed userspace package i8kutils.
1203
1204	  Say Y if you intend to run this kernel on old Dell laptops or want to
1205	  use userspace package i8kutils.
1206	  Say N otherwise.
1207
1208config X86_REBOOTFIXUPS
1209	bool "Enable X86 board specific fixups for reboot"
1210	depends on X86_32
1211	---help---
1212	  This enables chipset and/or board specific fixups to be done
1213	  in order to get reboot to work correctly. This is only needed on
1214	  some combinations of hardware and BIOS. The symptom, for which
1215	  this config is intended, is when reboot ends with a stalled/hung
1216	  system.
1217
1218	  Currently, the only fixup is for the Geode machines using
1219	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1220
1221	  Say Y if you want to enable the fixup. Currently, it's safe to
1222	  enable this option even if you don't need it.
1223	  Say N otherwise.
1224
1225config MICROCODE
1226	bool "CPU microcode loading support"
1227	default y
1228	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1229	select FW_LOADER
1230	---help---
1231	  If you say Y here, you will be able to update the microcode on
1232	  Intel and AMD processors. The Intel support is for the IA32 family,
1233	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1234	  AMD support is for families 0x10 and later. You will obviously need
1235	  the actual microcode binary data itself which is not shipped with
1236	  the Linux kernel.
1237
1238	  The preferred method to load microcode from a detached initrd is described
1239	  in Documentation/x86/early-microcode.txt. For that you need to enable
1240	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1241	  initrd for microcode blobs.
1242
1243	  In addition, you can build-in the microcode into the kernel. For that you
1244	  need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1245	  to the CONFIG_EXTRA_FIRMWARE config option.
1246
1247config MICROCODE_INTEL
1248	bool "Intel microcode loading support"
1249	depends on MICROCODE
1250	default MICROCODE
1251	select FW_LOADER
1252	---help---
1253	  This options enables microcode patch loading support for Intel
1254	  processors.
1255
1256	  For the current Intel microcode data package go to
1257	  <https://downloadcenter.intel.com> and search for
1258	  'Linux Processor Microcode Data File'.
1259
1260config MICROCODE_AMD
1261	bool "AMD microcode loading support"
1262	depends on MICROCODE
1263	select FW_LOADER
1264	---help---
1265	  If you select this option, microcode patch loading support for AMD
1266	  processors will be enabled.
1267
1268config MICROCODE_OLD_INTERFACE
1269	def_bool y
1270	depends on MICROCODE
1271
1272config X86_MSR
1273	tristate "/dev/cpu/*/msr - Model-specific register support"
1274	---help---
1275	  This device gives privileged processes access to the x86
1276	  Model-Specific Registers (MSRs).  It is a character device with
1277	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1278	  MSR accesses are directed to a specific CPU on multi-processor
1279	  systems.
1280
1281config X86_CPUID
1282	tristate "/dev/cpu/*/cpuid - CPU information support"
1283	---help---
1284	  This device gives processes access to the x86 CPUID instruction to
1285	  be executed on a specific processor.  It is a character device
1286	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1287	  /dev/cpu/31/cpuid.
1288
1289choice
1290	prompt "High Memory Support"
1291	default HIGHMEM4G
1292	depends on X86_32
1293
1294config NOHIGHMEM
1295	bool "off"
1296	---help---
1297	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1298	  However, the address space of 32-bit x86 processors is only 4
1299	  Gigabytes large. That means that, if you have a large amount of
1300	  physical memory, not all of it can be "permanently mapped" by the
1301	  kernel. The physical memory that's not permanently mapped is called
1302	  "high memory".
1303
1304	  If you are compiling a kernel which will never run on a machine with
1305	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1306	  choice and suitable for most users). This will result in a "3GB/1GB"
1307	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1308	  space and the remaining part of the 4GB virtual memory space is used
1309	  by the kernel to permanently map as much physical memory as
1310	  possible.
1311
1312	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1313	  answer "4GB" here.
1314
1315	  If more than 4 Gigabytes is used then answer "64GB" here. This
1316	  selection turns Intel PAE (Physical Address Extension) mode on.
1317	  PAE implements 3-level paging on IA32 processors. PAE is fully
1318	  supported by Linux, PAE mode is implemented on all recent Intel
1319	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1320	  then the kernel will not boot on CPUs that don't support PAE!
1321
1322	  The actual amount of total physical memory will either be
1323	  auto detected or can be forced by using a kernel command line option
1324	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1325	  your boot loader (lilo or loadlin) about how to pass options to the
1326	  kernel at boot time.)
1327
1328	  If unsure, say "off".
1329
1330config HIGHMEM4G
1331	bool "4GB"
1332	---help---
1333	  Select this if you have a 32-bit processor and between 1 and 4
1334	  gigabytes of physical RAM.
1335
1336config HIGHMEM64G
1337	bool "64GB"
1338	depends on !M486
1339	select X86_PAE
1340	---help---
1341	  Select this if you have a 32-bit processor and more than 4
1342	  gigabytes of physical RAM.
1343
1344endchoice
1345
1346choice
1347	prompt "Memory split" if EXPERT
1348	default VMSPLIT_3G
1349	depends on X86_32
1350	---help---
1351	  Select the desired split between kernel and user memory.
1352
1353	  If the address range available to the kernel is less than the
1354	  physical memory installed, the remaining memory will be available
1355	  as "high memory". Accessing high memory is a little more costly
1356	  than low memory, as it needs to be mapped into the kernel first.
1357	  Note that increasing the kernel address space limits the range
1358	  available to user programs, making the address space there
1359	  tighter.  Selecting anything other than the default 3G/1G split
1360	  will also likely make your kernel incompatible with binary-only
1361	  kernel modules.
1362
1363	  If you are not absolutely sure what you are doing, leave this
1364	  option alone!
1365
1366	config VMSPLIT_3G
1367		bool "3G/1G user/kernel split"
1368	config VMSPLIT_3G_OPT
1369		depends on !X86_PAE
1370		bool "3G/1G user/kernel split (for full 1G low memory)"
1371	config VMSPLIT_2G
1372		bool "2G/2G user/kernel split"
1373	config VMSPLIT_2G_OPT
1374		depends on !X86_PAE
1375		bool "2G/2G user/kernel split (for full 2G low memory)"
1376	config VMSPLIT_1G
1377		bool "1G/3G user/kernel split"
1378endchoice
1379
1380config PAGE_OFFSET
1381	hex
1382	default 0xB0000000 if VMSPLIT_3G_OPT
1383	default 0x80000000 if VMSPLIT_2G
1384	default 0x78000000 if VMSPLIT_2G_OPT
1385	default 0x40000000 if VMSPLIT_1G
1386	default 0xC0000000
1387	depends on X86_32
1388
1389config HIGHMEM
1390	def_bool y
1391	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1392
1393config X86_PAE
1394	bool "PAE (Physical Address Extension) Support"
1395	depends on X86_32 && !HIGHMEM4G
1396	select SWIOTLB
1397	---help---
1398	  PAE is required for NX support, and furthermore enables
1399	  larger swapspace support for non-overcommit purposes. It
1400	  has the cost of more pagetable lookup overhead, and also
1401	  consumes more pagetable space per process.
1402
1403config X86_5LEVEL
1404	bool "Enable 5-level page tables support"
1405	depends on X86_64
1406	---help---
1407	  5-level paging enables access to larger address space:
1408	  upto 128 PiB of virtual address space and 4 PiB of
1409	  physical address space.
1410
1411	  It will be supported by future Intel CPUs.
1412
1413	  Note: a kernel with this option enabled can only be booted
1414	  on machines that support the feature.
1415
1416	  See Documentation/x86/x86_64/5level-paging.txt for more
1417	  information.
1418
1419	  Say N if unsure.
1420
1421config ARCH_PHYS_ADDR_T_64BIT
1422	def_bool y
1423	depends on X86_64 || X86_PAE
1424
1425config ARCH_DMA_ADDR_T_64BIT
1426	def_bool y
1427	depends on X86_64 || HIGHMEM64G
1428
1429config X86_DIRECT_GBPAGES
1430	def_bool y
1431	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1432	---help---
1433	  Certain kernel features effectively disable kernel
1434	  linear 1 GB mappings (even if the CPU otherwise
1435	  supports them), so don't confuse the user by printing
1436	  that we have them enabled.
1437
1438config ARCH_HAS_MEM_ENCRYPT
1439	def_bool y
1440
1441config AMD_MEM_ENCRYPT
1442	bool "AMD Secure Memory Encryption (SME) support"
1443	depends on X86_64 && CPU_SUP_AMD
1444	---help---
1445	  Say yes to enable support for the encryption of system memory.
1446	  This requires an AMD processor that supports Secure Memory
1447	  Encryption (SME).
1448
1449config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1450	bool "Activate AMD Secure Memory Encryption (SME) by default"
1451	default y
1452	depends on AMD_MEM_ENCRYPT
1453	---help---
1454	  Say yes to have system memory encrypted by default if running on
1455	  an AMD processor that supports Secure Memory Encryption (SME).
1456
1457	  If set to Y, then the encryption of system memory can be
1458	  deactivated with the mem_encrypt=off command line option.
1459
1460	  If set to N, then the encryption of system memory can be
1461	  activated with the mem_encrypt=on command line option.
1462
1463config ARCH_USE_MEMREMAP_PROT
1464	def_bool y
1465	depends on AMD_MEM_ENCRYPT
1466
1467# Common NUMA Features
1468config NUMA
1469	bool "Numa Memory Allocation and Scheduler Support"
1470	depends on SMP
1471	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1472	default y if X86_BIGSMP
1473	---help---
1474	  Enable NUMA (Non Uniform Memory Access) support.
1475
1476	  The kernel will try to allocate memory used by a CPU on the
1477	  local memory controller of the CPU and add some more
1478	  NUMA awareness to the kernel.
1479
1480	  For 64-bit this is recommended if the system is Intel Core i7
1481	  (or later), AMD Opteron, or EM64T NUMA.
1482
1483	  For 32-bit this is only needed if you boot a 32-bit
1484	  kernel on a 64-bit NUMA platform.
1485
1486	  Otherwise, you should say N.
1487
1488config AMD_NUMA
1489	def_bool y
1490	prompt "Old style AMD Opteron NUMA detection"
1491	depends on X86_64 && NUMA && PCI
1492	---help---
1493	  Enable AMD NUMA node topology detection.  You should say Y here if
1494	  you have a multi processor AMD system. This uses an old method to
1495	  read the NUMA configuration directly from the builtin Northbridge
1496	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1497	  which also takes priority if both are compiled in.
1498
1499config X86_64_ACPI_NUMA
1500	def_bool y
1501	prompt "ACPI NUMA detection"
1502	depends on X86_64 && NUMA && ACPI && PCI
1503	select ACPI_NUMA
1504	---help---
1505	  Enable ACPI SRAT based node topology detection.
1506
1507# Some NUMA nodes have memory ranges that span
1508# other nodes.  Even though a pfn is valid and
1509# between a node's start and end pfns, it may not
1510# reside on that node.  See memmap_init_zone()
1511# for details.
1512config NODES_SPAN_OTHER_NODES
1513	def_bool y
1514	depends on X86_64_ACPI_NUMA
1515
1516config NUMA_EMU
1517	bool "NUMA emulation"
1518	depends on NUMA
1519	---help---
1520	  Enable NUMA emulation. A flat machine will be split
1521	  into virtual nodes when booted with "numa=fake=N", where N is the
1522	  number of nodes. This is only useful for debugging.
1523
1524config NODES_SHIFT
1525	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1526	range 1 10
1527	default "10" if MAXSMP
1528	default "6" if X86_64
1529	default "3"
1530	depends on NEED_MULTIPLE_NODES
1531	---help---
1532	  Specify the maximum number of NUMA Nodes available on the target
1533	  system.  Increases memory reserved to accommodate various tables.
1534
1535config ARCH_HAVE_MEMORY_PRESENT
1536	def_bool y
1537	depends on X86_32 && DISCONTIGMEM
1538
1539config NEED_NODE_MEMMAP_SIZE
1540	def_bool y
1541	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1542
1543config ARCH_FLATMEM_ENABLE
1544	def_bool y
1545	depends on X86_32 && !NUMA
1546
1547config ARCH_DISCONTIGMEM_ENABLE
1548	def_bool y
1549	depends on NUMA && X86_32
1550
1551config ARCH_DISCONTIGMEM_DEFAULT
1552	def_bool y
1553	depends on NUMA && X86_32
1554
1555config ARCH_SPARSEMEM_ENABLE
1556	def_bool y
1557	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1558	select SPARSEMEM_STATIC if X86_32
1559	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1560
1561config ARCH_SPARSEMEM_DEFAULT
1562	def_bool y
1563	depends on X86_64
1564
1565config ARCH_SELECT_MEMORY_MODEL
1566	def_bool y
1567	depends on ARCH_SPARSEMEM_ENABLE
1568
1569config ARCH_MEMORY_PROBE
1570	bool "Enable sysfs memory/probe interface"
1571	depends on X86_64 && MEMORY_HOTPLUG
1572	help
1573	  This option enables a sysfs memory/probe interface for testing.
1574	  See Documentation/memory-hotplug.txt for more information.
1575	  If you are unsure how to answer this question, answer N.
1576
1577config ARCH_PROC_KCORE_TEXT
1578	def_bool y
1579	depends on X86_64 && PROC_KCORE
1580
1581config ILLEGAL_POINTER_VALUE
1582       hex
1583       default 0 if X86_32
1584       default 0xdead000000000000 if X86_64
1585
1586source "mm/Kconfig"
1587
1588config X86_PMEM_LEGACY_DEVICE
1589	bool
1590
1591config X86_PMEM_LEGACY
1592	tristate "Support non-standard NVDIMMs and ADR protected memory"
1593	depends on PHYS_ADDR_T_64BIT
1594	depends on BLK_DEV
1595	select X86_PMEM_LEGACY_DEVICE
1596	select LIBNVDIMM
1597	help
1598	  Treat memory marked using the non-standard e820 type of 12 as used
1599	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1600	  The kernel will offer these regions to the 'pmem' driver so
1601	  they can be used for persistent storage.
1602
1603	  Say Y if unsure.
1604
1605config HIGHPTE
1606	bool "Allocate 3rd-level pagetables from highmem"
1607	depends on HIGHMEM
1608	---help---
1609	  The VM uses one page table entry for each page of physical memory.
1610	  For systems with a lot of RAM, this can be wasteful of precious
1611	  low memory.  Setting this option will put user-space page table
1612	  entries in high memory.
1613
1614config X86_CHECK_BIOS_CORRUPTION
1615	bool "Check for low memory corruption"
1616	---help---
1617	  Periodically check for memory corruption in low memory, which
1618	  is suspected to be caused by BIOS.  Even when enabled in the
1619	  configuration, it is disabled at runtime.  Enable it by
1620	  setting "memory_corruption_check=1" on the kernel command
1621	  line.  By default it scans the low 64k of memory every 60
1622	  seconds; see the memory_corruption_check_size and
1623	  memory_corruption_check_period parameters in
1624	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1625
1626	  When enabled with the default parameters, this option has
1627	  almost no overhead, as it reserves a relatively small amount
1628	  of memory and scans it infrequently.  It both detects corruption
1629	  and prevents it from affecting the running system.
1630
1631	  It is, however, intended as a diagnostic tool; if repeatable
1632	  BIOS-originated corruption always affects the same memory,
1633	  you can use memmap= to prevent the kernel from using that
1634	  memory.
1635
1636config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1637	bool "Set the default setting of memory_corruption_check"
1638	depends on X86_CHECK_BIOS_CORRUPTION
1639	default y
1640	---help---
1641	  Set whether the default state of memory_corruption_check is
1642	  on or off.
1643
1644config X86_RESERVE_LOW
1645	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1646	default 64
1647	range 4 640
1648	---help---
1649	  Specify the amount of low memory to reserve for the BIOS.
1650
1651	  The first page contains BIOS data structures that the kernel
1652	  must not use, so that page must always be reserved.
1653
1654	  By default we reserve the first 64K of physical RAM, as a
1655	  number of BIOSes are known to corrupt that memory range
1656	  during events such as suspend/resume or monitor cable
1657	  insertion, so it must not be used by the kernel.
1658
1659	  You can set this to 4 if you are absolutely sure that you
1660	  trust the BIOS to get all its memory reservations and usages
1661	  right.  If you know your BIOS have problems beyond the
1662	  default 64K area, you can set this to 640 to avoid using the
1663	  entire low memory range.
1664
1665	  If you have doubts about the BIOS (e.g. suspend/resume does
1666	  not work or there's kernel crashes after certain hardware
1667	  hotplug events) then you might want to enable
1668	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1669	  typical corruption patterns.
1670
1671	  Leave this to the default value of 64 if you are unsure.
1672
1673config MATH_EMULATION
1674	bool
1675	depends on MODIFY_LDT_SYSCALL
1676	prompt "Math emulation" if X86_32
1677	---help---
1678	  Linux can emulate a math coprocessor (used for floating point
1679	  operations) if you don't have one. 486DX and Pentium processors have
1680	  a math coprocessor built in, 486SX and 386 do not, unless you added
1681	  a 487DX or 387, respectively. (The messages during boot time can
1682	  give you some hints here ["man dmesg"].) Everyone needs either a
1683	  coprocessor or this emulation.
1684
1685	  If you don't have a math coprocessor, you need to say Y here; if you
1686	  say Y here even though you have a coprocessor, the coprocessor will
1687	  be used nevertheless. (This behavior can be changed with the kernel
1688	  command line option "no387", which comes handy if your coprocessor
1689	  is broken. Try "man bootparam" or see the documentation of your boot
1690	  loader (lilo or loadlin) about how to pass options to the kernel at
1691	  boot time.) This means that it is a good idea to say Y here if you
1692	  intend to use this kernel on different machines.
1693
1694	  More information about the internals of the Linux math coprocessor
1695	  emulation can be found in <file:arch/x86/math-emu/README>.
1696
1697	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1698	  kernel, it won't hurt.
1699
1700config MTRR
1701	def_bool y
1702	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1703	---help---
1704	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1705	  the Memory Type Range Registers (MTRRs) may be used to control
1706	  processor access to memory ranges. This is most useful if you have
1707	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1708	  allows bus write transfers to be combined into a larger transfer
1709	  before bursting over the PCI/AGP bus. This can increase performance
1710	  of image write operations 2.5 times or more. Saying Y here creates a
1711	  /proc/mtrr file which may be used to manipulate your processor's
1712	  MTRRs. Typically the X server should use this.
1713
1714	  This code has a reasonably generic interface so that similar
1715	  control registers on other processors can be easily supported
1716	  as well:
1717
1718	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1719	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1720	  these, the ARRs are used to emulate the MTRRs.
1721	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1722	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1723	  write-combining. All of these processors are supported by this code
1724	  and it makes sense to say Y here if you have one of them.
1725
1726	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1727	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1728	  can lead to all sorts of problems, so it's good to say Y here.
1729
1730	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1731	  just add about 9 KB to your kernel.
1732
1733	  See <file:Documentation/x86/mtrr.txt> for more information.
1734
1735config MTRR_SANITIZER
1736	def_bool y
1737	prompt "MTRR cleanup support"
1738	depends on MTRR
1739	---help---
1740	  Convert MTRR layout from continuous to discrete, so X drivers can
1741	  add writeback entries.
1742
1743	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1744	  The largest mtrr entry size for a continuous block can be set with
1745	  mtrr_chunk_size.
1746
1747	  If unsure, say Y.
1748
1749config MTRR_SANITIZER_ENABLE_DEFAULT
1750	int "MTRR cleanup enable value (0-1)"
1751	range 0 1
1752	default "0"
1753	depends on MTRR_SANITIZER
1754	---help---
1755	  Enable mtrr cleanup default value
1756
1757config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1758	int "MTRR cleanup spare reg num (0-7)"
1759	range 0 7
1760	default "1"
1761	depends on MTRR_SANITIZER
1762	---help---
1763	  mtrr cleanup spare entries default, it can be changed via
1764	  mtrr_spare_reg_nr=N on the kernel command line.
1765
1766config X86_PAT
1767	def_bool y
1768	prompt "x86 PAT support" if EXPERT
1769	depends on MTRR
1770	---help---
1771	  Use PAT attributes to setup page level cache control.
1772
1773	  PATs are the modern equivalents of MTRRs and are much more
1774	  flexible than MTRRs.
1775
1776	  Say N here if you see bootup problems (boot crash, boot hang,
1777	  spontaneous reboots) or a non-working video driver.
1778
1779	  If unsure, say Y.
1780
1781config ARCH_USES_PG_UNCACHED
1782	def_bool y
1783	depends on X86_PAT
1784
1785config ARCH_RANDOM
1786	def_bool y
1787	prompt "x86 architectural random number generator" if EXPERT
1788	---help---
1789	  Enable the x86 architectural RDRAND instruction
1790	  (Intel Bull Mountain technology) to generate random numbers.
1791	  If supported, this is a high bandwidth, cryptographically
1792	  secure hardware random number generator.
1793
1794config X86_SMAP
1795	def_bool y
1796	prompt "Supervisor Mode Access Prevention" if EXPERT
1797	---help---
1798	  Supervisor Mode Access Prevention (SMAP) is a security
1799	  feature in newer Intel processors.  There is a small
1800	  performance cost if this enabled and turned on; there is
1801	  also a small increase in the kernel size if this is enabled.
1802
1803	  If unsure, say Y.
1804
1805config X86_INTEL_MPX
1806	prompt "Intel MPX (Memory Protection Extensions)"
1807	def_bool n
1808	# Note: only available in 64-bit mode due to VMA flags shortage
1809	depends on CPU_SUP_INTEL && X86_64
1810	select ARCH_USES_HIGH_VMA_FLAGS
1811	---help---
1812	  MPX provides hardware features that can be used in
1813	  conjunction with compiler-instrumented code to check
1814	  memory references.  It is designed to detect buffer
1815	  overflow or underflow bugs.
1816
1817	  This option enables running applications which are
1818	  instrumented or otherwise use MPX.  It does not use MPX
1819	  itself inside the kernel or to protect the kernel
1820	  against bad memory references.
1821
1822	  Enabling this option will make the kernel larger:
1823	  ~8k of kernel text and 36 bytes of data on a 64-bit
1824	  defconfig.  It adds a long to the 'mm_struct' which
1825	  will increase the kernel memory overhead of each
1826	  process and adds some branches to paths used during
1827	  exec() and munmap().
1828
1829	  For details, see Documentation/x86/intel_mpx.txt
1830
1831	  If unsure, say N.
1832
1833config X86_INTEL_MEMORY_PROTECTION_KEYS
1834	prompt "Intel Memory Protection Keys"
1835	def_bool y
1836	# Note: only available in 64-bit mode
1837	depends on CPU_SUP_INTEL && X86_64
1838	select ARCH_USES_HIGH_VMA_FLAGS
1839	select ARCH_HAS_PKEYS
1840	---help---
1841	  Memory Protection Keys provides a mechanism for enforcing
1842	  page-based protections, but without requiring modification of the
1843	  page tables when an application changes protection domains.
1844
1845	  For details, see Documentation/x86/protection-keys.txt
1846
1847	  If unsure, say y.
1848
1849config EFI
1850	bool "EFI runtime service support"
1851	depends on ACPI
1852	select UCS2_STRING
1853	select EFI_RUNTIME_WRAPPERS
1854	---help---
1855	  This enables the kernel to use EFI runtime services that are
1856	  available (such as the EFI variable services).
1857
1858	  This option is only useful on systems that have EFI firmware.
1859	  In addition, you should use the latest ELILO loader available
1860	  at <http://elilo.sourceforge.net> in order to take advantage
1861	  of EFI runtime services. However, even with this option, the
1862	  resultant kernel should continue to boot on existing non-EFI
1863	  platforms.
1864
1865config EFI_STUB
1866       bool "EFI stub support"
1867       depends on EFI && !X86_USE_3DNOW
1868       select RELOCATABLE
1869       ---help---
1870          This kernel feature allows a bzImage to be loaded directly
1871	  by EFI firmware without the use of a bootloader.
1872
1873	  See Documentation/efi-stub.txt for more information.
1874
1875config EFI_MIXED
1876	bool "EFI mixed-mode support"
1877	depends on EFI_STUB && X86_64
1878	---help---
1879	   Enabling this feature allows a 64-bit kernel to be booted
1880	   on a 32-bit firmware, provided that your CPU supports 64-bit
1881	   mode.
1882
1883	   Note that it is not possible to boot a mixed-mode enabled
1884	   kernel via the EFI boot stub - a bootloader that supports
1885	   the EFI handover protocol must be used.
1886
1887	   If unsure, say N.
1888
1889config SECCOMP
1890	def_bool y
1891	prompt "Enable seccomp to safely compute untrusted bytecode"
1892	---help---
1893	  This kernel feature is useful for number crunching applications
1894	  that may need to compute untrusted bytecode during their
1895	  execution. By using pipes or other transports made available to
1896	  the process as file descriptors supporting the read/write
1897	  syscalls, it's possible to isolate those applications in
1898	  their own address space using seccomp. Once seccomp is
1899	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1900	  and the task is only allowed to execute a few safe syscalls
1901	  defined by each seccomp mode.
1902
1903	  If unsure, say Y. Only embedded should say N here.
1904
1905source kernel/Kconfig.hz
1906
1907config KEXEC
1908	bool "kexec system call"
1909	select KEXEC_CORE
1910	---help---
1911	  kexec is a system call that implements the ability to shutdown your
1912	  current kernel, and to start another kernel.  It is like a reboot
1913	  but it is independent of the system firmware.   And like a reboot
1914	  you can start any kernel with it, not just Linux.
1915
1916	  The name comes from the similarity to the exec system call.
1917
1918	  It is an ongoing process to be certain the hardware in a machine
1919	  is properly shutdown, so do not be surprised if this code does not
1920	  initially work for you.  As of this writing the exact hardware
1921	  interface is strongly in flux, so no good recommendation can be
1922	  made.
1923
1924config KEXEC_FILE
1925	bool "kexec file based system call"
1926	select KEXEC_CORE
1927	select BUILD_BIN2C
1928	depends on X86_64
1929	depends on CRYPTO=y
1930	depends on CRYPTO_SHA256=y
1931	---help---
1932	  This is new version of kexec system call. This system call is
1933	  file based and takes file descriptors as system call argument
1934	  for kernel and initramfs as opposed to list of segments as
1935	  accepted by previous system call.
1936
1937config KEXEC_VERIFY_SIG
1938	bool "Verify kernel signature during kexec_file_load() syscall"
1939	depends on KEXEC_FILE
1940	---help---
1941	  This option makes kernel signature verification mandatory for
1942	  the kexec_file_load() syscall.
1943
1944	  In addition to that option, you need to enable signature
1945	  verification for the corresponding kernel image type being
1946	  loaded in order for this to work.
1947
1948config KEXEC_BZIMAGE_VERIFY_SIG
1949	bool "Enable bzImage signature verification support"
1950	depends on KEXEC_VERIFY_SIG
1951	depends on SIGNED_PE_FILE_VERIFICATION
1952	select SYSTEM_TRUSTED_KEYRING
1953	---help---
1954	  Enable bzImage signature verification support.
1955
1956config CRASH_DUMP
1957	bool "kernel crash dumps"
1958	depends on X86_64 || (X86_32 && HIGHMEM)
1959	---help---
1960	  Generate crash dump after being started by kexec.
1961	  This should be normally only set in special crash dump kernels
1962	  which are loaded in the main kernel with kexec-tools into
1963	  a specially reserved region and then later executed after
1964	  a crash by kdump/kexec. The crash dump kernel must be compiled
1965	  to a memory address not used by the main kernel or BIOS using
1966	  PHYSICAL_START, or it must be built as a relocatable image
1967	  (CONFIG_RELOCATABLE=y).
1968	  For more details see Documentation/kdump/kdump.txt
1969
1970config KEXEC_JUMP
1971	bool "kexec jump"
1972	depends on KEXEC && HIBERNATION
1973	---help---
1974	  Jump between original kernel and kexeced kernel and invoke
1975	  code in physical address mode via KEXEC
1976
1977config PHYSICAL_START
1978	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1979	default "0x1000000"
1980	---help---
1981	  This gives the physical address where the kernel is loaded.
1982
1983	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1984	  bzImage will decompress itself to above physical address and
1985	  run from there. Otherwise, bzImage will run from the address where
1986	  it has been loaded by the boot loader and will ignore above physical
1987	  address.
1988
1989	  In normal kdump cases one does not have to set/change this option
1990	  as now bzImage can be compiled as a completely relocatable image
1991	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1992	  address. This option is mainly useful for the folks who don't want
1993	  to use a bzImage for capturing the crash dump and want to use a
1994	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
1995	  to be specifically compiled to run from a specific memory area
1996	  (normally a reserved region) and this option comes handy.
1997
1998	  So if you are using bzImage for capturing the crash dump,
1999	  leave the value here unchanged to 0x1000000 and set
2000	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2001	  for capturing the crash dump change this value to start of
2002	  the reserved region.  In other words, it can be set based on
2003	  the "X" value as specified in the "crashkernel=YM@XM"
2004	  command line boot parameter passed to the panic-ed
2005	  kernel. Please take a look at Documentation/kdump/kdump.txt
2006	  for more details about crash dumps.
2007
2008	  Usage of bzImage for capturing the crash dump is recommended as
2009	  one does not have to build two kernels. Same kernel can be used
2010	  as production kernel and capture kernel. Above option should have
2011	  gone away after relocatable bzImage support is introduced. But it
2012	  is present because there are users out there who continue to use
2013	  vmlinux for dump capture. This option should go away down the
2014	  line.
2015
2016	  Don't change this unless you know what you are doing.
2017
2018config RELOCATABLE
2019	bool "Build a relocatable kernel"
2020	default y
2021	---help---
2022	  This builds a kernel image that retains relocation information
2023	  so it can be loaded someplace besides the default 1MB.
2024	  The relocations tend to make the kernel binary about 10% larger,
2025	  but are discarded at runtime.
2026
2027	  One use is for the kexec on panic case where the recovery kernel
2028	  must live at a different physical address than the primary
2029	  kernel.
2030
2031	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2032	  it has been loaded at and the compile time physical address
2033	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2034
2035config RANDOMIZE_BASE
2036	bool "Randomize the address of the kernel image (KASLR)"
2037	depends on RELOCATABLE
2038	default y
2039	---help---
2040	  In support of Kernel Address Space Layout Randomization (KASLR),
2041	  this randomizes the physical address at which the kernel image
2042	  is decompressed and the virtual address where the kernel
2043	  image is mapped, as a security feature that deters exploit
2044	  attempts relying on knowledge of the location of kernel
2045	  code internals.
2046
2047	  On 64-bit, the kernel physical and virtual addresses are
2048	  randomized separately. The physical address will be anywhere
2049	  between 16MB and the top of physical memory (up to 64TB). The
2050	  virtual address will be randomized from 16MB up to 1GB (9 bits
2051	  of entropy). Note that this also reduces the memory space
2052	  available to kernel modules from 1.5GB to 1GB.
2053
2054	  On 32-bit, the kernel physical and virtual addresses are
2055	  randomized together. They will be randomized from 16MB up to
2056	  512MB (8 bits of entropy).
2057
2058	  Entropy is generated using the RDRAND instruction if it is
2059	  supported. If RDTSC is supported, its value is mixed into
2060	  the entropy pool as well. If neither RDRAND nor RDTSC are
2061	  supported, then entropy is read from the i8254 timer. The
2062	  usable entropy is limited by the kernel being built using
2063	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2064	  minimum of 2MB. As a result, only 10 bits of entropy are
2065	  theoretically possible, but the implementations are further
2066	  limited due to memory layouts.
2067
2068	  If unsure, say Y.
2069
2070# Relocation on x86 needs some additional build support
2071config X86_NEED_RELOCS
2072	def_bool y
2073	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2074
2075config PHYSICAL_ALIGN
2076	hex "Alignment value to which kernel should be aligned"
2077	default "0x200000"
2078	range 0x2000 0x1000000 if X86_32
2079	range 0x200000 0x1000000 if X86_64
2080	---help---
2081	  This value puts the alignment restrictions on physical address
2082	  where kernel is loaded and run from. Kernel is compiled for an
2083	  address which meets above alignment restriction.
2084
2085	  If bootloader loads the kernel at a non-aligned address and
2086	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2087	  address aligned to above value and run from there.
2088
2089	  If bootloader loads the kernel at a non-aligned address and
2090	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2091	  load address and decompress itself to the address it has been
2092	  compiled for and run from there. The address for which kernel is
2093	  compiled already meets above alignment restrictions. Hence the
2094	  end result is that kernel runs from a physical address meeting
2095	  above alignment restrictions.
2096
2097	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2098	  this value must be a multiple of 0x200000.
2099
2100	  Don't change this unless you know what you are doing.
2101
2102config RANDOMIZE_MEMORY
2103	bool "Randomize the kernel memory sections"
2104	depends on X86_64
2105	depends on RANDOMIZE_BASE
2106	default RANDOMIZE_BASE
2107	---help---
2108	   Randomizes the base virtual address of kernel memory sections
2109	   (physical memory mapping, vmalloc & vmemmap). This security feature
2110	   makes exploits relying on predictable memory locations less reliable.
2111
2112	   The order of allocations remains unchanged. Entropy is generated in
2113	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2114	   configuration have in average 30,000 different possible virtual
2115	   addresses for each memory section.
2116
2117	   If unsure, say Y.
2118
2119config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2120	hex "Physical memory mapping padding" if EXPERT
2121	depends on RANDOMIZE_MEMORY
2122	default "0xa" if MEMORY_HOTPLUG
2123	default "0x0"
2124	range 0x1 0x40 if MEMORY_HOTPLUG
2125	range 0x0 0x40
2126	---help---
2127	   Define the padding in terabytes added to the existing physical
2128	   memory size during kernel memory randomization. It is useful
2129	   for memory hotplug support but reduces the entropy available for
2130	   address randomization.
2131
2132	   If unsure, leave at the default value.
2133
2134config HOTPLUG_CPU
2135	bool "Support for hot-pluggable CPUs"
2136	depends on SMP
2137	---help---
2138	  Say Y here to allow turning CPUs off and on. CPUs can be
2139	  controlled through /sys/devices/system/cpu.
2140	  ( Note: power management support will enable this option
2141	    automatically on SMP systems. )
2142	  Say N if you want to disable CPU hotplug.
2143
2144config BOOTPARAM_HOTPLUG_CPU0
2145	bool "Set default setting of cpu0_hotpluggable"
2146	default n
2147	depends on HOTPLUG_CPU
2148	---help---
2149	  Set whether default state of cpu0_hotpluggable is on or off.
2150
2151	  Say Y here to enable CPU0 hotplug by default. If this switch
2152	  is turned on, there is no need to give cpu0_hotplug kernel
2153	  parameter and the CPU0 hotplug feature is enabled by default.
2154
2155	  Please note: there are two known CPU0 dependencies if you want
2156	  to enable the CPU0 hotplug feature either by this switch or by
2157	  cpu0_hotplug kernel parameter.
2158
2159	  First, resume from hibernate or suspend always starts from CPU0.
2160	  So hibernate and suspend are prevented if CPU0 is offline.
2161
2162	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2163	  offline if any interrupt can not migrate out of CPU0. There may
2164	  be other CPU0 dependencies.
2165
2166	  Please make sure the dependencies are under your control before
2167	  you enable this feature.
2168
2169	  Say N if you don't want to enable CPU0 hotplug feature by default.
2170	  You still can enable the CPU0 hotplug feature at boot by kernel
2171	  parameter cpu0_hotplug.
2172
2173config DEBUG_HOTPLUG_CPU0
2174	def_bool n
2175	prompt "Debug CPU0 hotplug"
2176	depends on HOTPLUG_CPU
2177	---help---
2178	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2179	  soon as possible and boots up userspace with CPU0 offlined. User
2180	  can online CPU0 back after boot time.
2181
2182	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2183	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2184	  compilation or giving cpu0_hotplug kernel parameter at boot.
2185
2186	  If unsure, say N.
2187
2188config COMPAT_VDSO
2189	def_bool n
2190	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2191	depends on COMPAT_32
2192	---help---
2193	  Certain buggy versions of glibc will crash if they are
2194	  presented with a 32-bit vDSO that is not mapped at the address
2195	  indicated in its segment table.
2196
2197	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2198	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2199	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2200	  the only released version with the bug, but OpenSUSE 9
2201	  contains a buggy "glibc 2.3.2".
2202
2203	  The symptom of the bug is that everything crashes on startup, saying:
2204	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2205
2206	  Saying Y here changes the default value of the vdso32 boot
2207	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2208	  This works around the glibc bug but hurts performance.
2209
2210	  If unsure, say N: if you are compiling your own kernel, you
2211	  are unlikely to be using a buggy version of glibc.
2212
2213choice
2214	prompt "vsyscall table for legacy applications"
2215	depends on X86_64
2216	default LEGACY_VSYSCALL_EMULATE
2217	help
2218	  Legacy user code that does not know how to find the vDSO expects
2219	  to be able to issue three syscalls by calling fixed addresses in
2220	  kernel space. Since this location is not randomized with ASLR,
2221	  it can be used to assist security vulnerability exploitation.
2222
2223	  This setting can be changed at boot time via the kernel command
2224	  line parameter vsyscall=[native|emulate|none].
2225
2226	  On a system with recent enough glibc (2.14 or newer) and no
2227	  static binaries, you can say None without a performance penalty
2228	  to improve security.
2229
2230	  If unsure, select "Emulate".
2231
2232	config LEGACY_VSYSCALL_NATIVE
2233		bool "Native"
2234		help
2235		  Actual executable code is located in the fixed vsyscall
2236		  address mapping, implementing time() efficiently. Since
2237		  this makes the mapping executable, it can be used during
2238		  security vulnerability exploitation (traditionally as
2239		  ROP gadgets). This configuration is not recommended.
2240
2241	config LEGACY_VSYSCALL_EMULATE
2242		bool "Emulate"
2243		help
2244		  The kernel traps and emulates calls into the fixed
2245		  vsyscall address mapping. This makes the mapping
2246		  non-executable, but it still contains known contents,
2247		  which could be used in certain rare security vulnerability
2248		  exploits. This configuration is recommended when userspace
2249		  still uses the vsyscall area.
2250
2251	config LEGACY_VSYSCALL_NONE
2252		bool "None"
2253		help
2254		  There will be no vsyscall mapping at all. This will
2255		  eliminate any risk of ASLR bypass due to the vsyscall
2256		  fixed address mapping. Attempts to use the vsyscalls
2257		  will be reported to dmesg, so that either old or
2258		  malicious userspace programs can be identified.
2259
2260endchoice
2261
2262config CMDLINE_BOOL
2263	bool "Built-in kernel command line"
2264	---help---
2265	  Allow for specifying boot arguments to the kernel at
2266	  build time.  On some systems (e.g. embedded ones), it is
2267	  necessary or convenient to provide some or all of the
2268	  kernel boot arguments with the kernel itself (that is,
2269	  to not rely on the boot loader to provide them.)
2270
2271	  To compile command line arguments into the kernel,
2272	  set this option to 'Y', then fill in the
2273	  boot arguments in CONFIG_CMDLINE.
2274
2275	  Systems with fully functional boot loaders (i.e. non-embedded)
2276	  should leave this option set to 'N'.
2277
2278config CMDLINE
2279	string "Built-in kernel command string"
2280	depends on CMDLINE_BOOL
2281	default ""
2282	---help---
2283	  Enter arguments here that should be compiled into the kernel
2284	  image and used at boot time.  If the boot loader provides a
2285	  command line at boot time, it is appended to this string to
2286	  form the full kernel command line, when the system boots.
2287
2288	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2289	  change this behavior.
2290
2291	  In most cases, the command line (whether built-in or provided
2292	  by the boot loader) should specify the device for the root
2293	  file system.
2294
2295config CMDLINE_OVERRIDE
2296	bool "Built-in command line overrides boot loader arguments"
2297	depends on CMDLINE_BOOL
2298	---help---
2299	  Set this option to 'Y' to have the kernel ignore the boot loader
2300	  command line, and use ONLY the built-in command line.
2301
2302	  This is used to work around broken boot loaders.  This should
2303	  be set to 'N' under normal conditions.
2304
2305config MODIFY_LDT_SYSCALL
2306	bool "Enable the LDT (local descriptor table)" if EXPERT
2307	default y
2308	---help---
2309	  Linux can allow user programs to install a per-process x86
2310	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2311	  call.  This is required to run 16-bit or segmented code such as
2312	  DOSEMU or some Wine programs.  It is also used by some very old
2313	  threading libraries.
2314
2315	  Enabling this feature adds a small amount of overhead to
2316	  context switches and increases the low-level kernel attack
2317	  surface.  Disabling it removes the modify_ldt(2) system call.
2318
2319	  Saying 'N' here may make sense for embedded or server kernels.
2320
2321source "kernel/livepatch/Kconfig"
2322
2323endmenu
2324
2325config ARCH_HAS_ADD_PAGES
2326	def_bool y
2327	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2328
2329config ARCH_ENABLE_MEMORY_HOTPLUG
2330	def_bool y
2331	depends on X86_64 || (X86_32 && HIGHMEM)
2332
2333config ARCH_ENABLE_MEMORY_HOTREMOVE
2334	def_bool y
2335	depends on MEMORY_HOTPLUG
2336
2337config USE_PERCPU_NUMA_NODE_ID
2338	def_bool y
2339	depends on NUMA
2340
2341config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2342	def_bool y
2343	depends on X86_64 || X86_PAE
2344
2345config ARCH_ENABLE_HUGEPAGE_MIGRATION
2346	def_bool y
2347	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2348
2349config ARCH_ENABLE_THP_MIGRATION
2350	def_bool y
2351	depends on X86_64 && TRANSPARENT_HUGEPAGE
2352
2353menu "Power management and ACPI options"
2354
2355config ARCH_HIBERNATION_HEADER
2356	def_bool y
2357	depends on X86_64 && HIBERNATION
2358
2359source "kernel/power/Kconfig"
2360
2361source "drivers/acpi/Kconfig"
2362
2363source "drivers/sfi/Kconfig"
2364
2365config X86_APM_BOOT
2366	def_bool y
2367	depends on APM
2368
2369menuconfig APM
2370	tristate "APM (Advanced Power Management) BIOS support"
2371	depends on X86_32 && PM_SLEEP
2372	---help---
2373	  APM is a BIOS specification for saving power using several different
2374	  techniques. This is mostly useful for battery powered laptops with
2375	  APM compliant BIOSes. If you say Y here, the system time will be
2376	  reset after a RESUME operation, the /proc/apm device will provide
2377	  battery status information, and user-space programs will receive
2378	  notification of APM "events" (e.g. battery status change).
2379
2380	  If you select "Y" here, you can disable actual use of the APM
2381	  BIOS by passing the "apm=off" option to the kernel at boot time.
2382
2383	  Note that the APM support is almost completely disabled for
2384	  machines with more than one CPU.
2385
2386	  In order to use APM, you will need supporting software. For location
2387	  and more information, read <file:Documentation/power/apm-acpi.txt>
2388	  and the Battery Powered Linux mini-HOWTO, available from
2389	  <http://www.tldp.org/docs.html#howto>.
2390
2391	  This driver does not spin down disk drives (see the hdparm(8)
2392	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2393	  VESA-compliant "green" monitors.
2394
2395	  This driver does not support the TI 4000M TravelMate and the ACER
2396	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2397	  desktop machines also don't have compliant BIOSes, and this driver
2398	  may cause those machines to panic during the boot phase.
2399
2400	  Generally, if you don't have a battery in your machine, there isn't
2401	  much point in using this driver and you should say N. If you get
2402	  random kernel OOPSes or reboots that don't seem to be related to
2403	  anything, try disabling/enabling this option (or disabling/enabling
2404	  APM in your BIOS).
2405
2406	  Some other things you should try when experiencing seemingly random,
2407	  "weird" problems:
2408
2409	  1) make sure that you have enough swap space and that it is
2410	  enabled.
2411	  2) pass the "no-hlt" option to the kernel
2412	  3) switch on floating point emulation in the kernel and pass
2413	  the "no387" option to the kernel
2414	  4) pass the "floppy=nodma" option to the kernel
2415	  5) pass the "mem=4M" option to the kernel (thereby disabling
2416	  all but the first 4 MB of RAM)
2417	  6) make sure that the CPU is not over clocked.
2418	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2419	  8) disable the cache from your BIOS settings
2420	  9) install a fan for the video card or exchange video RAM
2421	  10) install a better fan for the CPU
2422	  11) exchange RAM chips
2423	  12) exchange the motherboard.
2424
2425	  To compile this driver as a module, choose M here: the
2426	  module will be called apm.
2427
2428if APM
2429
2430config APM_IGNORE_USER_SUSPEND
2431	bool "Ignore USER SUSPEND"
2432	---help---
2433	  This option will ignore USER SUSPEND requests. On machines with a
2434	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2435	  series notebooks, it is necessary to say Y because of a BIOS bug.
2436
2437config APM_DO_ENABLE
2438	bool "Enable PM at boot time"
2439	---help---
2440	  Enable APM features at boot time. From page 36 of the APM BIOS
2441	  specification: "When disabled, the APM BIOS does not automatically
2442	  power manage devices, enter the Standby State, enter the Suspend
2443	  State, or take power saving steps in response to CPU Idle calls."
2444	  This driver will make CPU Idle calls when Linux is idle (unless this
2445	  feature is turned off -- see "Do CPU IDLE calls", below). This
2446	  should always save battery power, but more complicated APM features
2447	  will be dependent on your BIOS implementation. You may need to turn
2448	  this option off if your computer hangs at boot time when using APM
2449	  support, or if it beeps continuously instead of suspending. Turn
2450	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2451	  T400CDT. This is off by default since most machines do fine without
2452	  this feature.
2453
2454config APM_CPU_IDLE
2455	depends on CPU_IDLE
2456	bool "Make CPU Idle calls when idle"
2457	---help---
2458	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2459	  On some machines, this can activate improved power savings, such as
2460	  a slowed CPU clock rate, when the machine is idle. These idle calls
2461	  are made after the idle loop has run for some length of time (e.g.,
2462	  333 mS). On some machines, this will cause a hang at boot time or
2463	  whenever the CPU becomes idle. (On machines with more than one CPU,
2464	  this option does nothing.)
2465
2466config APM_DISPLAY_BLANK
2467	bool "Enable console blanking using APM"
2468	---help---
2469	  Enable console blanking using the APM. Some laptops can use this to
2470	  turn off the LCD backlight when the screen blanker of the Linux
2471	  virtual console blanks the screen. Note that this is only used by
2472	  the virtual console screen blanker, and won't turn off the backlight
2473	  when using the X Window system. This also doesn't have anything to
2474	  do with your VESA-compliant power-saving monitor. Further, this
2475	  option doesn't work for all laptops -- it might not turn off your
2476	  backlight at all, or it might print a lot of errors to the console,
2477	  especially if you are using gpm.
2478
2479config APM_ALLOW_INTS
2480	bool "Allow interrupts during APM BIOS calls"
2481	---help---
2482	  Normally we disable external interrupts while we are making calls to
2483	  the APM BIOS as a measure to lessen the effects of a badly behaving
2484	  BIOS implementation.  The BIOS should reenable interrupts if it
2485	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2486	  many of the newer IBM Thinkpads.  If you experience hangs when you
2487	  suspend, try setting this to Y.  Otherwise, say N.
2488
2489endif # APM
2490
2491source "drivers/cpufreq/Kconfig"
2492
2493source "drivers/cpuidle/Kconfig"
2494
2495source "drivers/idle/Kconfig"
2496
2497endmenu
2498
2499
2500menu "Bus options (PCI etc.)"
2501
2502config PCI
2503	bool "PCI support"
2504	default y
2505	---help---
2506	  Find out whether you have a PCI motherboard. PCI is the name of a
2507	  bus system, i.e. the way the CPU talks to the other stuff inside
2508	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2509	  VESA. If you have PCI, say Y, otherwise N.
2510
2511choice
2512	prompt "PCI access mode"
2513	depends on X86_32 && PCI
2514	default PCI_GOANY
2515	---help---
2516	  On PCI systems, the BIOS can be used to detect the PCI devices and
2517	  determine their configuration. However, some old PCI motherboards
2518	  have BIOS bugs and may crash if this is done. Also, some embedded
2519	  PCI-based systems don't have any BIOS at all. Linux can also try to
2520	  detect the PCI hardware directly without using the BIOS.
2521
2522	  With this option, you can specify how Linux should detect the
2523	  PCI devices. If you choose "BIOS", the BIOS will be used,
2524	  if you choose "Direct", the BIOS won't be used, and if you
2525	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2526	  If you choose "Any", the kernel will try MMCONFIG, then the
2527	  direct access method and falls back to the BIOS if that doesn't
2528	  work. If unsure, go with the default, which is "Any".
2529
2530config PCI_GOBIOS
2531	bool "BIOS"
2532
2533config PCI_GOMMCONFIG
2534	bool "MMConfig"
2535
2536config PCI_GODIRECT
2537	bool "Direct"
2538
2539config PCI_GOOLPC
2540	bool "OLPC XO-1"
2541	depends on OLPC
2542
2543config PCI_GOANY
2544	bool "Any"
2545
2546endchoice
2547
2548config PCI_BIOS
2549	def_bool y
2550	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2551
2552# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2553config PCI_DIRECT
2554	def_bool y
2555	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2556
2557config PCI_MMCONFIG
2558	def_bool y
2559	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2560
2561config PCI_OLPC
2562	def_bool y
2563	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2564
2565config PCI_XEN
2566	def_bool y
2567	depends on PCI && XEN
2568	select SWIOTLB_XEN
2569
2570config PCI_DOMAINS
2571	def_bool y
2572	depends on PCI
2573
2574config PCI_MMCONFIG
2575	bool "Support mmconfig PCI config space access"
2576	depends on X86_64 && PCI && ACPI
2577
2578config PCI_CNB20LE_QUIRK
2579	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2580	depends on PCI
2581	help
2582	  Read the PCI windows out of the CNB20LE host bridge. This allows
2583	  PCI hotplug to work on systems with the CNB20LE chipset which do
2584	  not have ACPI.
2585
2586	  There's no public spec for this chipset, and this functionality
2587	  is known to be incomplete.
2588
2589	  You should say N unless you know you need this.
2590
2591source "drivers/pci/Kconfig"
2592
2593config ISA_BUS
2594	bool "ISA-style bus support on modern systems" if EXPERT
2595	select ISA_BUS_API
2596	help
2597	  Enables ISA-style drivers on modern systems. This is necessary to
2598	  support PC/104 devices on X86_64 platforms.
2599
2600	  If unsure, say N.
2601
2602# x86_64 have no ISA slots, but can have ISA-style DMA.
2603config ISA_DMA_API
2604	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2605	default y
2606	help
2607	  Enables ISA-style DMA support for devices requiring such controllers.
2608	  If unsure, say Y.
2609
2610if X86_32
2611
2612config ISA
2613	bool "ISA support"
2614	---help---
2615	  Find out whether you have ISA slots on your motherboard.  ISA is the
2616	  name of a bus system, i.e. the way the CPU talks to the other stuff
2617	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2618	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2619	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2620
2621config EISA
2622	bool "EISA support"
2623	depends on ISA
2624	---help---
2625	  The Extended Industry Standard Architecture (EISA) bus was
2626	  developed as an open alternative to the IBM MicroChannel bus.
2627
2628	  The EISA bus provided some of the features of the IBM MicroChannel
2629	  bus while maintaining backward compatibility with cards made for
2630	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2631	  1995 when it was made obsolete by the PCI bus.
2632
2633	  Say Y here if you are building a kernel for an EISA-based machine.
2634
2635	  Otherwise, say N.
2636
2637source "drivers/eisa/Kconfig"
2638
2639config SCx200
2640	tristate "NatSemi SCx200 support"
2641	---help---
2642	  This provides basic support for National Semiconductor's
2643	  (now AMD's) Geode processors.  The driver probes for the
2644	  PCI-IDs of several on-chip devices, so its a good dependency
2645	  for other scx200_* drivers.
2646
2647	  If compiled as a module, the driver is named scx200.
2648
2649config SCx200HR_TIMER
2650	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2651	depends on SCx200
2652	default y
2653	---help---
2654	  This driver provides a clocksource built upon the on-chip
2655	  27MHz high-resolution timer.  Its also a workaround for
2656	  NSC Geode SC-1100's buggy TSC, which loses time when the
2657	  processor goes idle (as is done by the scheduler).  The
2658	  other workaround is idle=poll boot option.
2659
2660config OLPC
2661	bool "One Laptop Per Child support"
2662	depends on !X86_PAE
2663	select GPIOLIB
2664	select OF
2665	select OF_PROMTREE
2666	select IRQ_DOMAIN
2667	---help---
2668	  Add support for detecting the unique features of the OLPC
2669	  XO hardware.
2670
2671config OLPC_XO1_PM
2672	bool "OLPC XO-1 Power Management"
2673	depends on OLPC && MFD_CS5535 && PM_SLEEP
2674	select MFD_CORE
2675	---help---
2676	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2677
2678config OLPC_XO1_RTC
2679	bool "OLPC XO-1 Real Time Clock"
2680	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2681	---help---
2682	  Add support for the XO-1 real time clock, which can be used as a
2683	  programmable wakeup source.
2684
2685config OLPC_XO1_SCI
2686	bool "OLPC XO-1 SCI extras"
2687	depends on OLPC && OLPC_XO1_PM
2688	depends on INPUT=y
2689	select POWER_SUPPLY
2690	select GPIO_CS5535
2691	select MFD_CORE
2692	---help---
2693	  Add support for SCI-based features of the OLPC XO-1 laptop:
2694	   - EC-driven system wakeups
2695	   - Power button
2696	   - Ebook switch
2697	   - Lid switch
2698	   - AC adapter status updates
2699	   - Battery status updates
2700
2701config OLPC_XO15_SCI
2702	bool "OLPC XO-1.5 SCI extras"
2703	depends on OLPC && ACPI
2704	select POWER_SUPPLY
2705	---help---
2706	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2707	   - EC-driven system wakeups
2708	   - AC adapter status updates
2709	   - Battery status updates
2710
2711config ALIX
2712	bool "PCEngines ALIX System Support (LED setup)"
2713	select GPIOLIB
2714	---help---
2715	  This option enables system support for the PCEngines ALIX.
2716	  At present this just sets up LEDs for GPIO control on
2717	  ALIX2/3/6 boards.  However, other system specific setup should
2718	  get added here.
2719
2720	  Note: You must still enable the drivers for GPIO and LED support
2721	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2722
2723	  Note: You have to set alix.force=1 for boards with Award BIOS.
2724
2725config NET5501
2726	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2727	select GPIOLIB
2728	---help---
2729	  This option enables system support for the Soekris Engineering net5501.
2730
2731config GEOS
2732	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2733	select GPIOLIB
2734	depends on DMI
2735	---help---
2736	  This option enables system support for the Traverse Technologies GEOS.
2737
2738config TS5500
2739	bool "Technologic Systems TS-5500 platform support"
2740	depends on MELAN
2741	select CHECK_SIGNATURE
2742	select NEW_LEDS
2743	select LEDS_CLASS
2744	---help---
2745	  This option enables system support for the Technologic Systems TS-5500.
2746
2747endif # X86_32
2748
2749config AMD_NB
2750	def_bool y
2751	depends on CPU_SUP_AMD && PCI
2752
2753source "drivers/pcmcia/Kconfig"
2754
2755config RAPIDIO
2756	tristate "RapidIO support"
2757	depends on PCI
2758	default n
2759	help
2760	  If enabled this option will include drivers and the core
2761	  infrastructure code to support RapidIO interconnect devices.
2762
2763source "drivers/rapidio/Kconfig"
2764
2765config X86_SYSFB
2766	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2767	help
2768	  Firmwares often provide initial graphics framebuffers so the BIOS,
2769	  bootloader or kernel can show basic video-output during boot for
2770	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2771	  Extensions and EFI-framebuffers for this, which are mostly limited
2772	  to x86.
2773	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2774	  framebuffers so the new generic system-framebuffer drivers can be
2775	  used on x86. If the framebuffer is not compatible with the generic
2776	  modes, it is adverticed as fallback platform framebuffer so legacy
2777	  drivers like efifb, vesafb and uvesafb can pick it up.
2778	  If this option is not selected, all system framebuffers are always
2779	  marked as fallback platform framebuffers as usual.
2780
2781	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2782	  not be able to pick up generic system framebuffers if this option
2783	  is selected. You are highly encouraged to enable simplefb as
2784	  replacement if you select this option. simplefb can correctly deal
2785	  with generic system framebuffers. But you should still keep vesafb
2786	  and others enabled as fallback if a system framebuffer is
2787	  incompatible with simplefb.
2788
2789	  If unsure, say Y.
2790
2791endmenu
2792
2793
2794menu "Executable file formats / Emulations"
2795
2796source "fs/Kconfig.binfmt"
2797
2798config IA32_EMULATION
2799	bool "IA32 Emulation"
2800	depends on X86_64
2801	select ARCH_WANT_OLD_COMPAT_IPC
2802	select BINFMT_ELF
2803	select COMPAT_BINFMT_ELF
2804	select COMPAT_OLD_SIGACTION
2805	---help---
2806	  Include code to run legacy 32-bit programs under a
2807	  64-bit kernel. You should likely turn this on, unless you're
2808	  100% sure that you don't have any 32-bit programs left.
2809
2810config IA32_AOUT
2811	tristate "IA32 a.out support"
2812	depends on IA32_EMULATION
2813	---help---
2814	  Support old a.out binaries in the 32bit emulation.
2815
2816config X86_X32
2817	bool "x32 ABI for 64-bit mode"
2818	depends on X86_64
2819	---help---
2820	  Include code to run binaries for the x32 native 32-bit ABI
2821	  for 64-bit processors.  An x32 process gets access to the
2822	  full 64-bit register file and wide data path while leaving
2823	  pointers at 32 bits for smaller memory footprint.
2824
2825	  You will need a recent binutils (2.22 or later) with
2826	  elf32_x86_64 support enabled to compile a kernel with this
2827	  option set.
2828
2829config COMPAT_32
2830	def_bool y
2831	depends on IA32_EMULATION || X86_32
2832	select HAVE_UID16
2833	select OLD_SIGSUSPEND3
2834
2835config COMPAT
2836	def_bool y
2837	depends on IA32_EMULATION || X86_X32
2838
2839if COMPAT
2840config COMPAT_FOR_U64_ALIGNMENT
2841	def_bool y
2842
2843config SYSVIPC_COMPAT
2844	def_bool y
2845	depends on SYSVIPC
2846endif
2847
2848endmenu
2849
2850
2851config HAVE_ATOMIC_IOMAP
2852	def_bool y
2853	depends on X86_32
2854
2855config X86_DEV_DMA_OPS
2856	bool
2857	depends on X86_64 || STA2X11
2858
2859config X86_DMA_REMAP
2860	bool
2861	depends on STA2X11
2862
2863config HAVE_GENERIC_GUP
2864	def_bool y
2865
2866source "net/Kconfig"
2867
2868source "drivers/Kconfig"
2869
2870source "drivers/firmware/Kconfig"
2871
2872source "fs/Kconfig"
2873
2874source "arch/x86/Kconfig.debug"
2875
2876source "security/Kconfig"
2877
2878source "crypto/Kconfig"
2879
2880source "arch/x86/kvm/Kconfig"
2881
2882source "lib/Kconfig"
2883