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1# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4	bool "64-bit kernel" if "$(ARCH)" = "x86"
5	default "$(ARCH)" != "i386"
6	---help---
7	  Say yes to build a 64-bit kernel - formerly known as x86_64
8	  Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
11	def_bool y
12	depends on !64BIT
13	# Options that are inherently 32-bit kernel only:
14	select ARCH_WANT_IPC_PARSE_VERSION
15	select CLKSRC_I8253
16	select CLONE_BACKWARDS
17	select HAVE_DEBUG_STACKOVERFLOW
18	select MODULES_USE_ELF_REL
19	select OLD_SIGACTION
20	select GENERIC_VDSO_32
21
22config X86_64
23	def_bool y
24	depends on 64BIT
25	# Options that are inherently 64-bit kernel only:
26	select ARCH_HAS_GIGANTIC_PAGE
27	select ARCH_SUPPORTS_INT128
28	select ARCH_USE_CMPXCHG_LOCKREF
29	select HAVE_ARCH_SOFT_DIRTY
30	select MODULES_USE_ELF_RELA
31	select NEED_DMA_MAP_STATE
32	select SWIOTLB
33	select ARCH_HAS_SYSCALL_WRAPPER
34
35config FORCE_DYNAMIC_FTRACE
36	def_bool y
37	depends on X86_32
38	depends on FUNCTION_TRACER
39	select DYNAMIC_FTRACE
40	help
41	 We keep the static function tracing (!DYNAMIC_FTRACE) around
42	 in order to test the non static function tracing in the
43	 generic code, as other architectures still use it. But we
44	 only need to keep it around for x86_64. No need to keep it
45	 for x86_32. For x86_32, force DYNAMIC_FTRACE.
46#
47# Arch settings
48#
49# ( Note that options that are marked 'if X86_64' could in principle be
50#   ported to 32-bit as well. )
51#
52config X86
53	def_bool y
54	#
55	# Note: keep this list sorted alphabetically
56	#
57	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
58	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
59	select ARCH_32BIT_OFF_T			if X86_32
60	select ARCH_CLOCKSOURCE_DATA
61	select ARCH_CLOCKSOURCE_INIT
62	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
63	select ARCH_HAS_DEBUG_VIRTUAL
64	select ARCH_HAS_DEVMEM_IS_ALLOWED
65	select ARCH_HAS_ELF_RANDOMIZE
66	select ARCH_HAS_FAST_MULTIPLIER
67	select ARCH_HAS_FILTER_PGPROT
68	select ARCH_HAS_FORTIFY_SOURCE
69	select ARCH_HAS_GCOV_PROFILE_ALL
70	select ARCH_HAS_KCOV			if X86_64
71	select ARCH_HAS_MEM_ENCRYPT
72	select ARCH_HAS_MEMBARRIER_SYNC_CORE
73	select ARCH_HAS_PMEM_API		if X86_64
74	select ARCH_HAS_PTE_DEVMAP		if X86_64
75	select ARCH_HAS_PTE_SPECIAL
76	select ARCH_HAS_REFCOUNT
77	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
78	select ARCH_HAS_UACCESS_MCSAFE		if X86_64 && X86_MCE
79	select ARCH_HAS_SET_MEMORY
80	select ARCH_HAS_SET_DIRECT_MAP
81	select ARCH_HAS_STRICT_KERNEL_RWX
82	select ARCH_HAS_STRICT_MODULE_RWX
83	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
84	select ARCH_HAS_UBSAN_SANITIZE_ALL
85	select ARCH_HAVE_NMI_SAFE_CMPXCHG
86	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
87	select ARCH_MIGHT_HAVE_PC_PARPORT
88	select ARCH_MIGHT_HAVE_PC_SERIO
89	select ARCH_STACKWALK
90	select ARCH_SUPPORTS_ACPI
91	select ARCH_SUPPORTS_ATOMIC_RMW
92	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
93	select ARCH_SUPPORTS_LTO_CLANG		if X86_64
94	select ARCH_SUPPORTS_THINLTO		if X86_64
95	select ARCH_USE_BUILTIN_BSWAP
96	select ARCH_USE_QUEUED_RWLOCKS
97	select ARCH_USE_QUEUED_SPINLOCKS
98	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
99	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
100	select ARCH_WANT_HUGE_PMD_SHARE
101	select ARCH_WANTS_THP_SWAP		if X86_64
102	select BUILDTIME_EXTABLE_SORT
103	select CLKEVT_I8253
104	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
105	select CLOCKSOURCE_WATCHDOG
106	select DCACHE_WORD_ACCESS
107	select EDAC_ATOMIC_SCRUB
108	select EDAC_SUPPORT
109	select GENERIC_CLOCKEVENTS
110	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
111	select GENERIC_CLOCKEVENTS_MIN_ADJUST
112	select GENERIC_CMOS_UPDATE
113	select GENERIC_CPU_AUTOPROBE
114	select GENERIC_CPU_VULNERABILITIES
115	select GENERIC_EARLY_IOREMAP
116	select GENERIC_FIND_FIRST_BIT
117	select GENERIC_IOMAP
118	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
119	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
120	select GENERIC_IRQ_MIGRATION		if SMP
121	select GENERIC_IRQ_PROBE
122	select GENERIC_IRQ_RESERVATION_MODE
123	select GENERIC_IRQ_SHOW
124	select GENERIC_PENDING_IRQ		if SMP
125	select GENERIC_SMP_IDLE_THREAD
126	select GENERIC_STRNCPY_FROM_USER
127	select GENERIC_STRNLEN_USER
128	select GENERIC_TIME_VSYSCALL
129	select GENERIC_GETTIMEOFDAY
130	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
131	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
132	select HAVE_ACPI_APEI			if ACPI
133	select HAVE_ACPI_APEI_NMI		if ACPI
134	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
135	select HAVE_ARCH_AUDITSYSCALL
136	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
137	select HAVE_ARCH_JUMP_LABEL
138	select HAVE_ARCH_JUMP_LABEL_RELATIVE
139	select HAVE_ARCH_KASAN			if X86_64
140	select HAVE_ARCH_KGDB
141	select HAVE_ARCH_MMAP_RND_BITS		if MMU
142	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
143	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
144	select HAVE_ARCH_PREL32_RELOCATIONS	if !LTO_CLANG
145	select HAVE_ARCH_SECCOMP_FILTER
146	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
147	select HAVE_ARCH_STACKLEAK
148	select HAVE_ARCH_TRACEHOOK
149	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
150	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
151	select HAVE_ARCH_VMAP_STACK		if X86_64
152	select HAVE_ARCH_WITHIN_STACK_FRAMES
153	select HAVE_ASM_MODVERSIONS
154	select HAVE_CMPXCHG_DOUBLE
155	select HAVE_CMPXCHG_LOCAL
156	select HAVE_CONTEXT_TRACKING		if X86_64
157	select HAVE_COPY_THREAD_TLS
158	select HAVE_C_RECORDMCOUNT
159	select HAVE_DEBUG_KMEMLEAK
160	select HAVE_DMA_CONTIGUOUS
161	select HAVE_DYNAMIC_FTRACE
162	select HAVE_DYNAMIC_FTRACE_WITH_REGS
163	select HAVE_EBPF_JIT
164	select HAVE_EFFICIENT_UNALIGNED_ACCESS
165	select HAVE_EISA
166	select HAVE_EXIT_THREAD
167	select HAVE_FAST_GUP
168	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
169	select HAVE_FTRACE_MCOUNT_RECORD
170	select HAVE_FUNCTION_GRAPH_TRACER
171	select HAVE_FUNCTION_TRACER
172	select HAVE_GCC_PLUGINS
173	select HAVE_HW_BREAKPOINT
174	select HAVE_IDE
175	select HAVE_IOREMAP_PROT
176	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
177	select HAVE_IRQ_TIME_ACCOUNTING
178	select HAVE_KERNEL_BZIP2
179	select HAVE_KERNEL_GZIP
180	select HAVE_KERNEL_LZ4
181	select HAVE_KERNEL_LZMA
182	select HAVE_KERNEL_LZO
183	select HAVE_KERNEL_XZ
184	select HAVE_KPROBES
185	select HAVE_KPROBES_ON_FTRACE
186	select HAVE_FUNCTION_ERROR_INJECTION
187	select HAVE_KRETPROBES
188	select HAVE_KVM
189	select HAVE_LIVEPATCH			if X86_64
190	select HAVE_MEMBLOCK_NODE_MAP
191	select HAVE_MIXED_BREAKPOINTS_REGS
192	select HAVE_MOD_ARCH_SPECIFIC
193	select HAVE_MOVE_PMD
194	select HAVE_NMI
195	select HAVE_OPROFILE
196	select HAVE_OPTPROBES
197	select HAVE_PCSPKR_PLATFORM
198	select HAVE_PERF_EVENTS
199	select HAVE_PERF_EVENTS_NMI
200	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
201	select HAVE_PCI
202	select HAVE_PERF_REGS
203	select HAVE_PERF_USER_STACK_DUMP
204	select HAVE_RCU_TABLE_FREE		if PARAVIRT
205	select HAVE_REGS_AND_STACK_ACCESS_API
206	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
207	select HAVE_FUNCTION_ARG_ACCESS_API
208	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
209	select HAVE_STACK_VALIDATION		if X86_64 && !LTO_CLANG
210	select HAVE_RSEQ
211	select HAVE_SYSCALL_TRACEPOINTS
212	select HAVE_UNSTABLE_SCHED_CLOCK
213	select HAVE_USER_RETURN_NOTIFIER
214	select HAVE_GENERIC_VDSO
215	select HOTPLUG_SMT			if SMP
216	select IRQ_FORCED_THREADING
217	select NEED_SG_DMA_LENGTH
218	select PCI_DOMAINS			if PCI
219	select PCI_LOCKLESS_CONFIG		if PCI
220	select PERF_EVENTS
221	select RTC_LIB
222	select RTC_MC146818_LIB
223	select SPARSE_IRQ
224	select SRCU
225	select SYSCTL_EXCEPTION_TRACE
226	select THREAD_INFO_IN_TASK
227	select USER_STACKTRACE_SUPPORT
228	select VIRT_TO_BUS
229	select X86_FEATURE_NAMES		if PROC_FS
230	select PROC_PID_ARCH_STATUS		if PROC_FS
231
232config INSTRUCTION_DECODER
233	def_bool y
234	depends on KPROBES || PERF_EVENTS || UPROBES
235
236config OUTPUT_FORMAT
237	string
238	default "elf32-i386" if X86_32
239	default "elf64-x86-64" if X86_64
240
241config ARCH_DEFCONFIG
242	string
243	default "arch/x86/configs/i386_defconfig" if X86_32
244	default "arch/x86/configs/x86_64_defconfig" if X86_64
245
246config LOCKDEP_SUPPORT
247	def_bool y
248
249config STACKTRACE_SUPPORT
250	def_bool y
251
252config MMU
253	def_bool y
254
255config ARCH_MMAP_RND_BITS_MIN
256	default 28 if 64BIT
257	default 8
258
259config ARCH_MMAP_RND_BITS_MAX
260	default 32 if 64BIT
261	default 16
262
263config ARCH_MMAP_RND_COMPAT_BITS_MIN
264	default 8
265
266config ARCH_MMAP_RND_COMPAT_BITS_MAX
267	default 16
268
269config SBUS
270	bool
271
272config GENERIC_ISA_DMA
273	def_bool y
274	depends on ISA_DMA_API
275
276config GENERIC_BUG
277	def_bool y
278	depends on BUG
279	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
280
281config GENERIC_BUG_RELATIVE_POINTERS
282	bool
283
284config ARCH_MAY_HAVE_PC_FDC
285	def_bool y
286	depends on ISA_DMA_API
287
288config GENERIC_CALIBRATE_DELAY
289	def_bool y
290
291config ARCH_HAS_CPU_RELAX
292	def_bool y
293
294config ARCH_HAS_CACHE_LINE_SIZE
295	def_bool y
296
297config ARCH_HAS_FILTER_PGPROT
298	def_bool y
299
300config HAVE_SETUP_PER_CPU_AREA
301	def_bool y
302
303config NEED_PER_CPU_EMBED_FIRST_CHUNK
304	def_bool y
305
306config NEED_PER_CPU_PAGE_FIRST_CHUNK
307	def_bool y
308
309config ARCH_HIBERNATION_POSSIBLE
310	def_bool y
311
312config ARCH_SUSPEND_POSSIBLE
313	def_bool y
314
315config ARCH_WANT_GENERAL_HUGETLB
316	def_bool y
317
318config ZONE_DMA32
319	def_bool y if X86_64
320
321config AUDIT_ARCH
322	def_bool y if X86_64
323
324config ARCH_SUPPORTS_DEBUG_PAGEALLOC
325	def_bool y
326
327config KASAN_SHADOW_OFFSET
328	hex
329	depends on KASAN
330	default 0xdffffc0000000000
331
332config HAVE_INTEL_TXT
333	def_bool y
334	depends on INTEL_IOMMU && ACPI
335
336config X86_32_SMP
337	def_bool y
338	depends on X86_32 && SMP
339
340config X86_64_SMP
341	def_bool y
342	depends on X86_64 && SMP
343
344config X86_32_LAZY_GS
345	def_bool y
346	depends on X86_32 && !STACKPROTECTOR
347
348config ARCH_SUPPORTS_UPROBES
349	def_bool y
350
351config FIX_EARLYCON_MEM
352	def_bool y
353
354config DYNAMIC_PHYSICAL_MASK
355	bool
356
357config PGTABLE_LEVELS
358	int
359	default 5 if X86_5LEVEL
360	default 4 if X86_64
361	default 3 if X86_PAE
362	default 2
363
364config CC_HAS_SANE_STACKPROTECTOR
365	bool
366	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
367	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
368	help
369	   We have to make sure stack protector is unconditionally disabled if
370	   the compiler produces broken code.
371
372menu "Processor type and features"
373
374config ZONE_DMA
375	bool "DMA memory allocation support" if EXPERT
376	default y
377	help
378	  DMA memory allocation support allows devices with less than 32-bit
379	  addressing to allocate within the first 16MB of address space.
380	  Disable if no such devices will be used.
381
382	  If unsure, say Y.
383
384config SMP
385	bool "Symmetric multi-processing support"
386	---help---
387	  This enables support for systems with more than one CPU. If you have
388	  a system with only one CPU, say N. If you have a system with more
389	  than one CPU, say Y.
390
391	  If you say N here, the kernel will run on uni- and multiprocessor
392	  machines, but will use only one CPU of a multiprocessor machine. If
393	  you say Y here, the kernel will run on many, but not all,
394	  uniprocessor machines. On a uniprocessor machine, the kernel
395	  will run faster if you say N here.
396
397	  Note that if you say Y here and choose architecture "586" or
398	  "Pentium" under "Processor family", the kernel will not work on 486
399	  architectures. Similarly, multiprocessor kernels for the "PPro"
400	  architecture may not work on all Pentium based boards.
401
402	  People using multiprocessor machines who say Y here should also say
403	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
404	  Management" code will be disabled if you say Y here.
405
406	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
407	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
408	  <http://www.tldp.org/docs.html#howto>.
409
410	  If you don't know what to do here, say N.
411
412config X86_FEATURE_NAMES
413	bool "Processor feature human-readable names" if EMBEDDED
414	default y
415	---help---
416	  This option compiles in a table of x86 feature bits and corresponding
417	  names.  This is required to support /proc/cpuinfo and a few kernel
418	  messages.  You can disable this to save space, at the expense of
419	  making those few kernel messages show numeric feature bits instead.
420
421	  If in doubt, say Y.
422
423config X86_X2APIC
424	bool "Support x2apic"
425	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
426	---help---
427	  This enables x2apic support on CPUs that have this feature.
428
429	  This allows 32-bit apic IDs (so it can support very large systems),
430	  and accesses the local apic via MSRs not via mmio.
431
432	  If you don't know what to do here, say N.
433
434config X86_MPPARSE
435	bool "Enable MPS table" if ACPI || SFI
436	default y
437	depends on X86_LOCAL_APIC
438	---help---
439	  For old smp systems that do not have proper acpi support. Newer systems
440	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
441
442config GOLDFISH
443       def_bool y
444       depends on X86_GOLDFISH
445
446config RETPOLINE
447	bool "Avoid speculative indirect branches in kernel"
448	default y
449	select STACK_VALIDATION if HAVE_STACK_VALIDATION
450	help
451	  Compile kernel with the retpoline compiler options to guard against
452	  kernel-to-user data leaks by avoiding speculative indirect
453	  branches. Requires a compiler with -mindirect-branch=thunk-extern
454	  support for full protection. The kernel may run slower.
455
456config X86_CPU_RESCTRL
457	bool "x86 CPU resource control support"
458	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
459	select KERNFS
460	help
461	  Enable x86 CPU resource control support.
462
463	  Provide support for the allocation and monitoring of system resources
464	  usage by the CPU.
465
466	  Intel calls this Intel Resource Director Technology
467	  (Intel(R) RDT). More information about RDT can be found in the
468	  Intel x86 Architecture Software Developer Manual.
469
470	  AMD calls this AMD Platform Quality of Service (AMD QoS).
471	  More information about AMD QoS can be found in the AMD64 Technology
472	  Platform Quality of Service Extensions manual.
473
474	  Say N if unsure.
475
476if X86_32
477config X86_BIGSMP
478	bool "Support for big SMP systems with more than 8 CPUs"
479	depends on SMP
480	---help---
481	  This option is needed for the systems that have more than 8 CPUs
482
483config X86_EXTENDED_PLATFORM
484	bool "Support for extended (non-PC) x86 platforms"
485	default y
486	---help---
487	  If you disable this option then the kernel will only support
488	  standard PC platforms. (which covers the vast majority of
489	  systems out there.)
490
491	  If you enable this option then you'll be able to select support
492	  for the following (non-PC) 32 bit x86 platforms:
493		Goldfish (Android emulator)
494		AMD Elan
495		RDC R-321x SoC
496		SGI 320/540 (Visual Workstation)
497		STA2X11-based (e.g. Northville)
498		Moorestown MID devices
499
500	  If you have one of these systems, or if you want to build a
501	  generic distribution kernel, say Y here - otherwise say N.
502endif
503
504if X86_64
505config X86_EXTENDED_PLATFORM
506	bool "Support for extended (non-PC) x86 platforms"
507	default y
508	---help---
509	  If you disable this option then the kernel will only support
510	  standard PC platforms. (which covers the vast majority of
511	  systems out there.)
512
513	  If you enable this option then you'll be able to select support
514	  for the following (non-PC) 64 bit x86 platforms:
515		Numascale NumaChip
516		ScaleMP vSMP
517		SGI Ultraviolet
518
519	  If you have one of these systems, or if you want to build a
520	  generic distribution kernel, say Y here - otherwise say N.
521endif
522# This is an alphabetically sorted list of 64 bit extended platforms
523# Please maintain the alphabetic order if and when there are additions
524config X86_NUMACHIP
525	bool "Numascale NumaChip"
526	depends on X86_64
527	depends on X86_EXTENDED_PLATFORM
528	depends on NUMA
529	depends on SMP
530	depends on X86_X2APIC
531	depends on PCI_MMCONFIG
532	---help---
533	  Adds support for Numascale NumaChip large-SMP systems. Needed to
534	  enable more than ~168 cores.
535	  If you don't have one of these, you should say N here.
536
537config X86_VSMP
538	bool "ScaleMP vSMP"
539	select HYPERVISOR_GUEST
540	select PARAVIRT
541	depends on X86_64 && PCI
542	depends on X86_EXTENDED_PLATFORM
543	depends on SMP
544	---help---
545	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
546	  supposed to run on these EM64T-based machines.  Only choose this option
547	  if you have one of these machines.
548
549config X86_UV
550	bool "SGI Ultraviolet"
551	depends on X86_64
552	depends on X86_EXTENDED_PLATFORM
553	depends on NUMA
554	depends on EFI
555	depends on X86_X2APIC
556	depends on PCI
557	---help---
558	  This option is needed in order to support SGI Ultraviolet systems.
559	  If you don't have one of these, you should say N here.
560
561# Following is an alphabetically sorted list of 32 bit extended platforms
562# Please maintain the alphabetic order if and when there are additions
563
564config X86_GOLDFISH
565       bool "Goldfish (Virtual Platform)"
566       depends on X86_EXTENDED_PLATFORM
567       ---help---
568	 Enable support for the Goldfish virtual platform used primarily
569	 for Android development. Unless you are building for the Android
570	 Goldfish emulator say N here.
571
572config X86_INTEL_CE
573	bool "CE4100 TV platform"
574	depends on PCI
575	depends on PCI_GODIRECT
576	depends on X86_IO_APIC
577	depends on X86_32
578	depends on X86_EXTENDED_PLATFORM
579	select X86_REBOOTFIXUPS
580	select OF
581	select OF_EARLY_FLATTREE
582	---help---
583	  Select for the Intel CE media processor (CE4100) SOC.
584	  This option compiles in support for the CE4100 SOC for settop
585	  boxes and media devices.
586
587config X86_INTEL_MID
588	bool "Intel MID platform support"
589	depends on X86_EXTENDED_PLATFORM
590	depends on X86_PLATFORM_DEVICES
591	depends on PCI
592	depends on X86_64 || (PCI_GOANY && X86_32)
593	depends on X86_IO_APIC
594	select SFI
595	select I2C
596	select DW_APB_TIMER
597	select APB_TIMER
598	select INTEL_SCU_IPC
599	select MFD_INTEL_MSIC
600	---help---
601	  Select to build a kernel capable of supporting Intel MID (Mobile
602	  Internet Device) platform systems which do not have the PCI legacy
603	  interfaces. If you are building for a PC class system say N here.
604
605	  Intel MID platforms are based on an Intel processor and chipset which
606	  consume less power than most of the x86 derivatives.
607
608config X86_INTEL_QUARK
609	bool "Intel Quark platform support"
610	depends on X86_32
611	depends on X86_EXTENDED_PLATFORM
612	depends on X86_PLATFORM_DEVICES
613	depends on X86_TSC
614	depends on PCI
615	depends on PCI_GOANY
616	depends on X86_IO_APIC
617	select IOSF_MBI
618	select INTEL_IMR
619	select COMMON_CLK
620	---help---
621	  Select to include support for Quark X1000 SoC.
622	  Say Y here if you have a Quark based system such as the Arduino
623	  compatible Intel Galileo.
624
625config X86_INTEL_LPSS
626	bool "Intel Low Power Subsystem Support"
627	depends on X86 && ACPI && PCI
628	select COMMON_CLK
629	select PINCTRL
630	select IOSF_MBI
631	---help---
632	  Select to build support for Intel Low Power Subsystem such as
633	  found on Intel Lynxpoint PCH. Selecting this option enables
634	  things like clock tree (common clock framework) and pincontrol
635	  which are needed by the LPSS peripheral drivers.
636
637config X86_AMD_PLATFORM_DEVICE
638	bool "AMD ACPI2Platform devices support"
639	depends on ACPI
640	select COMMON_CLK
641	select PINCTRL
642	---help---
643	  Select to interpret AMD specific ACPI device to platform device
644	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
645	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
646	  implemented under PINCTRL subsystem.
647
648config IOSF_MBI
649	tristate "Intel SoC IOSF Sideband support for SoC platforms"
650	depends on PCI
651	---help---
652	  This option enables sideband register access support for Intel SoC
653	  platforms. On these platforms the IOSF sideband is used in lieu of
654	  MSR's for some register accesses, mostly but not limited to thermal
655	  and power. Drivers may query the availability of this device to
656	  determine if they need the sideband in order to work on these
657	  platforms. The sideband is available on the following SoC products.
658	  This list is not meant to be exclusive.
659	   - BayTrail
660	   - Braswell
661	   - Quark
662
663	  You should say Y if you are running a kernel on one of these SoC's.
664
665config IOSF_MBI_DEBUG
666	bool "Enable IOSF sideband access through debugfs"
667	depends on IOSF_MBI && DEBUG_FS
668	---help---
669	  Select this option to expose the IOSF sideband access registers (MCR,
670	  MDR, MCRX) through debugfs to write and read register information from
671	  different units on the SoC. This is most useful for obtaining device
672	  state information for debug and analysis. As this is a general access
673	  mechanism, users of this option would have specific knowledge of the
674	  device they want to access.
675
676	  If you don't require the option or are in doubt, say N.
677
678config X86_RDC321X
679	bool "RDC R-321x SoC"
680	depends on X86_32
681	depends on X86_EXTENDED_PLATFORM
682	select M486
683	select X86_REBOOTFIXUPS
684	---help---
685	  This option is needed for RDC R-321x system-on-chip, also known
686	  as R-8610-(G).
687	  If you don't have one of these chips, you should say N here.
688
689config X86_32_NON_STANDARD
690	bool "Support non-standard 32-bit SMP architectures"
691	depends on X86_32 && SMP
692	depends on X86_EXTENDED_PLATFORM
693	---help---
694	  This option compiles in the bigsmp and STA2X11 default
695	  subarchitectures.  It is intended for a generic binary
696	  kernel. If you select them all, kernel will probe it one by
697	  one and will fallback to default.
698
699# Alphabetically sorted list of Non standard 32 bit platforms
700
701config X86_SUPPORTS_MEMORY_FAILURE
702	def_bool y
703	# MCE code calls memory_failure():
704	depends on X86_MCE
705	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
706	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
707	depends on X86_64 || !SPARSEMEM
708	select ARCH_SUPPORTS_MEMORY_FAILURE
709
710config STA2X11
711	bool "STA2X11 Companion Chip Support"
712	depends on X86_32_NON_STANDARD && PCI
713	select ARCH_HAS_PHYS_TO_DMA
714	select SWIOTLB
715	select MFD_STA2X11
716	select GPIOLIB
717	---help---
718	  This adds support for boards based on the STA2X11 IO-Hub,
719	  a.k.a. "ConneXt". The chip is used in place of the standard
720	  PC chipset, so all "standard" peripherals are missing. If this
721	  option is selected the kernel will still be able to boot on
722	  standard PC machines.
723
724config X86_32_IRIS
725	tristate "Eurobraille/Iris poweroff module"
726	depends on X86_32
727	---help---
728	  The Iris machines from EuroBraille do not have APM or ACPI support
729	  to shut themselves down properly.  A special I/O sequence is
730	  needed to do so, which is what this module does at
731	  kernel shutdown.
732
733	  This is only for Iris machines from EuroBraille.
734
735	  If unused, say N.
736
737config SCHED_OMIT_FRAME_POINTER
738	def_bool y
739	prompt "Single-depth WCHAN output"
740	depends on X86
741	---help---
742	  Calculate simpler /proc/<PID>/wchan values. If this option
743	  is disabled then wchan values will recurse back to the
744	  caller function. This provides more accurate wchan values,
745	  at the expense of slightly more scheduling overhead.
746
747	  If in doubt, say "Y".
748
749menuconfig HYPERVISOR_GUEST
750	bool "Linux guest support"
751	---help---
752	  Say Y here to enable options for running Linux under various hyper-
753	  visors. This option enables basic hypervisor detection and platform
754	  setup.
755
756	  If you say N, all options in this submenu will be skipped and
757	  disabled, and Linux guest support won't be built in.
758
759if HYPERVISOR_GUEST
760
761config PARAVIRT
762	bool "Enable paravirtualization code"
763	---help---
764	  This changes the kernel so it can modify itself when it is run
765	  under a hypervisor, potentially improving performance significantly
766	  over full virtualization.  However, when run without a hypervisor
767	  the kernel is theoretically slower and slightly larger.
768
769config PARAVIRT_XXL
770	bool
771
772config PARAVIRT_DEBUG
773	bool "paravirt-ops debugging"
774	depends on PARAVIRT && DEBUG_KERNEL
775	---help---
776	  Enable to debug paravirt_ops internals.  Specifically, BUG if
777	  a paravirt_op is missing when it is called.
778
779config PARAVIRT_SPINLOCKS
780	bool "Paravirtualization layer for spinlocks"
781	depends on PARAVIRT && SMP
782	---help---
783	  Paravirtualized spinlocks allow a pvops backend to replace the
784	  spinlock implementation with something virtualization-friendly
785	  (for example, block the virtual CPU rather than spinning).
786
787	  It has a minimal impact on native kernels and gives a nice performance
788	  benefit on paravirtualized KVM / Xen kernels.
789
790	  If you are unsure how to answer this question, answer Y.
791
792config X86_HV_CALLBACK_VECTOR
793	def_bool n
794
795source "arch/x86/xen/Kconfig"
796
797config KVM_GUEST
798	bool "KVM Guest support (including kvmclock)"
799	depends on PARAVIRT
800	select PARAVIRT_CLOCK
801	select ARCH_CPUIDLE_HALTPOLL
802	default y
803	---help---
804	  This option enables various optimizations for running under the KVM
805	  hypervisor. It includes a paravirtualized clock, so that instead
806	  of relying on a PIT (or probably other) emulation by the
807	  underlying device model, the host provides the guest with
808	  timing infrastructure such as time of day, and system time
809
810config ARCH_CPUIDLE_HALTPOLL
811        def_bool n
812        prompt "Disable host haltpoll when loading haltpoll driver"
813        help
814	  If virtualized under KVM, disable host haltpoll.
815
816config PVH
817	bool "Support for running PVH guests"
818	---help---
819	  This option enables the PVH entry point for guest virtual machines
820	  as specified in the x86/HVM direct boot ABI.
821
822config KVM_DEBUG_FS
823	bool "Enable debug information for KVM Guests in debugfs"
824	depends on KVM_GUEST && DEBUG_FS
825	---help---
826	  This option enables collection of various statistics for KVM guest.
827	  Statistics are displayed in debugfs filesystem. Enabling this option
828	  may incur significant overhead.
829
830config PARAVIRT_TIME_ACCOUNTING
831	bool "Paravirtual steal time accounting"
832	depends on PARAVIRT
833	---help---
834	  Select this option to enable fine granularity task steal time
835	  accounting. Time spent executing other tasks in parallel with
836	  the current vCPU is discounted from the vCPU power. To account for
837	  that, there can be a small performance impact.
838
839	  If in doubt, say N here.
840
841config PARAVIRT_CLOCK
842	bool
843
844config JAILHOUSE_GUEST
845	bool "Jailhouse non-root cell support"
846	depends on X86_64 && PCI
847	select X86_PM_TIMER
848	---help---
849	  This option allows to run Linux as guest in a Jailhouse non-root
850	  cell. You can leave this option disabled if you only want to start
851	  Jailhouse and run Linux afterwards in the root cell.
852
853config ACRN_GUEST
854	bool "ACRN Guest support"
855	depends on X86_64
856	select X86_HV_CALLBACK_VECTOR
857	help
858	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
859	  a flexible, lightweight reference open-source hypervisor, built with
860	  real-time and safety-criticality in mind. It is built for embedded
861	  IOT with small footprint and real-time features. More details can be
862	  found in https://projectacrn.org/.
863
864endif #HYPERVISOR_GUEST
865
866source "arch/x86/Kconfig.cpu"
867
868config HPET_TIMER
869	def_bool X86_64
870	prompt "HPET Timer Support" if X86_32
871	---help---
872	  Use the IA-PC HPET (High Precision Event Timer) to manage
873	  time in preference to the PIT and RTC, if a HPET is
874	  present.
875	  HPET is the next generation timer replacing legacy 8254s.
876	  The HPET provides a stable time base on SMP
877	  systems, unlike the TSC, but it is more expensive to access,
878	  as it is off-chip.  The interface used is documented
879	  in the HPET spec, revision 1.
880
881	  You can safely choose Y here.  However, HPET will only be
882	  activated if the platform and the BIOS support this feature.
883	  Otherwise the 8254 will be used for timing services.
884
885	  Choose N to continue using the legacy 8254 timer.
886
887config HPET_EMULATE_RTC
888	def_bool y
889	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
890
891config APB_TIMER
892       def_bool y if X86_INTEL_MID
893       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
894       select DW_APB_TIMER
895       depends on X86_INTEL_MID && SFI
896       help
897         APB timer is the replacement for 8254, HPET on X86 MID platforms.
898         The APBT provides a stable time base on SMP
899         systems, unlike the TSC, but it is more expensive to access,
900         as it is off-chip. APB timers are always running regardless of CPU
901         C states, they are used as per CPU clockevent device when possible.
902
903# Mark as expert because too many people got it wrong.
904# The code disables itself when not needed.
905config DMI
906	default y
907	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
908	bool "Enable DMI scanning" if EXPERT
909	---help---
910	  Enabled scanning of DMI to identify machine quirks. Say Y
911	  here unless you have verified that your setup is not
912	  affected by entries in the DMI blacklist. Required by PNP
913	  BIOS code.
914
915config GART_IOMMU
916	bool "Old AMD GART IOMMU support"
917	select IOMMU_HELPER
918	select SWIOTLB
919	depends on X86_64 && PCI && AMD_NB
920	---help---
921	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
922	  GART based hardware IOMMUs.
923
924	  The GART supports full DMA access for devices with 32-bit access
925	  limitations, on systems with more than 3 GB. This is usually needed
926	  for USB, sound, many IDE/SATA chipsets and some other devices.
927
928	  Newer systems typically have a modern AMD IOMMU, supported via
929	  the CONFIG_AMD_IOMMU=y config option.
930
931	  In normal configurations this driver is only active when needed:
932	  there's more than 3 GB of memory and the system contains a
933	  32-bit limited device.
934
935	  If unsure, say Y.
936
937config CALGARY_IOMMU
938	bool "IBM Calgary IOMMU support"
939	select IOMMU_HELPER
940	select SWIOTLB
941	depends on X86_64 && PCI
942	---help---
943	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
944	  systems. Needed to run systems with more than 3GB of memory
945	  properly with 32-bit PCI devices that do not support DAC
946	  (Double Address Cycle). Calgary also supports bus level
947	  isolation, where all DMAs pass through the IOMMU.  This
948	  prevents them from going anywhere except their intended
949	  destination. This catches hard-to-find kernel bugs and
950	  mis-behaving drivers and devices that do not use the DMA-API
951	  properly to set up their DMA buffers.  The IOMMU can be
952	  turned off at boot time with the iommu=off parameter.
953	  Normally the kernel will make the right choice by itself.
954	  If unsure, say Y.
955
956config CALGARY_IOMMU_ENABLED_BY_DEFAULT
957	def_bool y
958	prompt "Should Calgary be enabled by default?"
959	depends on CALGARY_IOMMU
960	---help---
961	  Should Calgary be enabled by default? if you choose 'y', Calgary
962	  will be used (if it exists). If you choose 'n', Calgary will not be
963	  used even if it exists. If you choose 'n' and would like to use
964	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
965	  If unsure, say Y.
966
967config MAXSMP
968	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
969	depends on X86_64 && SMP && DEBUG_KERNEL
970	select CPUMASK_OFFSTACK
971	---help---
972	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
973	  If unsure, say N.
974
975#
976# The maximum number of CPUs supported:
977#
978# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
979# and which can be configured interactively in the
980# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
981#
982# The ranges are different on 32-bit and 64-bit kernels, depending on
983# hardware capabilities and scalability features of the kernel.
984#
985# ( If MAXSMP is enabled we just use the highest possible value and disable
986#   interactive configuration. )
987#
988
989config NR_CPUS_RANGE_BEGIN
990	int
991	default NR_CPUS_RANGE_END if MAXSMP
992	default    1 if !SMP
993	default    2
994
995config NR_CPUS_RANGE_END
996	int
997	depends on X86_32
998	default   64 if  SMP &&  X86_BIGSMP
999	default    8 if  SMP && !X86_BIGSMP
1000	default    1 if !SMP
1001
1002config NR_CPUS_RANGE_END
1003	int
1004	depends on X86_64
1005	default 8192 if  SMP && ( MAXSMP ||  CPUMASK_OFFSTACK)
1006	default  512 if  SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
1007	default    1 if !SMP
1008
1009config NR_CPUS_DEFAULT
1010	int
1011	depends on X86_32
1012	default   32 if  X86_BIGSMP
1013	default    8 if  SMP
1014	default    1 if !SMP
1015
1016config NR_CPUS_DEFAULT
1017	int
1018	depends on X86_64
1019	default 8192 if  MAXSMP
1020	default   64 if  SMP
1021	default    1 if !SMP
1022
1023config NR_CPUS
1024	int "Maximum number of CPUs" if SMP && !MAXSMP
1025	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1026	default NR_CPUS_DEFAULT
1027	---help---
1028	  This allows you to specify the maximum number of CPUs which this
1029	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1030	  supported value is 8192, otherwise the maximum value is 512.  The
1031	  minimum value which makes sense is 2.
1032
1033	  This is purely to save memory: each supported CPU adds about 8KB
1034	  to the kernel image.
1035
1036config SCHED_SMT
1037	def_bool y if SMP
1038
1039config SCHED_MC
1040	def_bool y
1041	prompt "Multi-core scheduler support"
1042	depends on SMP
1043	---help---
1044	  Multi-core scheduler support improves the CPU scheduler's decision
1045	  making when dealing with multi-core CPU chips at a cost of slightly
1046	  increased overhead in some places. If unsure say N here.
1047
1048config SCHED_MC_PRIO
1049	bool "CPU core priorities scheduler support"
1050	depends on SCHED_MC && CPU_SUP_INTEL
1051	select X86_INTEL_PSTATE
1052	select CPU_FREQ
1053	default y
1054	---help---
1055	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1056	  core ordering determined at manufacturing time, which allows
1057	  certain cores to reach higher turbo frequencies (when running
1058	  single threaded workloads) than others.
1059
1060	  Enabling this kernel feature teaches the scheduler about
1061	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1062	  scheduler's CPU selection logic accordingly, so that higher
1063	  overall system performance can be achieved.
1064
1065	  This feature will have no effect on CPUs without this feature.
1066
1067	  If unsure say Y here.
1068
1069config UP_LATE_INIT
1070       def_bool y
1071       depends on !SMP && X86_LOCAL_APIC
1072
1073config X86_UP_APIC
1074	bool "Local APIC support on uniprocessors" if !PCI_MSI
1075	default PCI_MSI
1076	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1077	---help---
1078	  A local APIC (Advanced Programmable Interrupt Controller) is an
1079	  integrated interrupt controller in the CPU. If you have a single-CPU
1080	  system which has a processor with a local APIC, you can say Y here to
1081	  enable and use it. If you say Y here even though your machine doesn't
1082	  have a local APIC, then the kernel will still run with no slowdown at
1083	  all. The local APIC supports CPU-generated self-interrupts (timer,
1084	  performance counters), and the NMI watchdog which detects hard
1085	  lockups.
1086
1087config X86_UP_IOAPIC
1088	bool "IO-APIC support on uniprocessors"
1089	depends on X86_UP_APIC
1090	---help---
1091	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1092	  SMP-capable replacement for PC-style interrupt controllers. Most
1093	  SMP systems and many recent uniprocessor systems have one.
1094
1095	  If you have a single-CPU system with an IO-APIC, you can say Y here
1096	  to use it. If you say Y here even though your machine doesn't have
1097	  an IO-APIC, then the kernel will still run with no slowdown at all.
1098
1099config X86_LOCAL_APIC
1100	def_bool y
1101	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1102	select IRQ_DOMAIN_HIERARCHY
1103	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1104
1105config X86_IO_APIC
1106	def_bool y
1107	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1108
1109config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1110	bool "Reroute for broken boot IRQs"
1111	depends on X86_IO_APIC
1112	---help---
1113	  This option enables a workaround that fixes a source of
1114	  spurious interrupts. This is recommended when threaded
1115	  interrupt handling is used on systems where the generation of
1116	  superfluous "boot interrupts" cannot be disabled.
1117
1118	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1119	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1120	  kernel does during interrupt handling). On chipsets where this
1121	  boot IRQ generation cannot be disabled, this workaround keeps
1122	  the original IRQ line masked so that only the equivalent "boot
1123	  IRQ" is delivered to the CPUs. The workaround also tells the
1124	  kernel to set up the IRQ handler on the boot IRQ line. In this
1125	  way only one interrupt is delivered to the kernel. Otherwise
1126	  the spurious second interrupt may cause the kernel to bring
1127	  down (vital) interrupt lines.
1128
1129	  Only affects "broken" chipsets. Interrupt sharing may be
1130	  increased on these systems.
1131
1132config X86_MCE
1133	bool "Machine Check / overheating reporting"
1134	select GENERIC_ALLOCATOR
1135	default y
1136	---help---
1137	  Machine Check support allows the processor to notify the
1138	  kernel if it detects a problem (e.g. overheating, data corruption).
1139	  The action the kernel takes depends on the severity of the problem,
1140	  ranging from warning messages to halting the machine.
1141
1142config X86_MCELOG_LEGACY
1143	bool "Support for deprecated /dev/mcelog character device"
1144	depends on X86_MCE
1145	---help---
1146	  Enable support for /dev/mcelog which is needed by the old mcelog
1147	  userspace logging daemon. Consider switching to the new generation
1148	  rasdaemon solution.
1149
1150config X86_MCE_INTEL
1151	def_bool y
1152	prompt "Intel MCE features"
1153	depends on X86_MCE && X86_LOCAL_APIC
1154	---help---
1155	   Additional support for intel specific MCE features such as
1156	   the thermal monitor.
1157
1158config X86_MCE_AMD
1159	def_bool y
1160	prompt "AMD MCE features"
1161	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1162	---help---
1163	   Additional support for AMD specific MCE features such as
1164	   the DRAM Error Threshold.
1165
1166config X86_ANCIENT_MCE
1167	bool "Support for old Pentium 5 / WinChip machine checks"
1168	depends on X86_32 && X86_MCE
1169	---help---
1170	  Include support for machine check handling on old Pentium 5 or WinChip
1171	  systems. These typically need to be enabled explicitly on the command
1172	  line.
1173
1174config X86_MCE_THRESHOLD
1175	depends on X86_MCE_AMD || X86_MCE_INTEL
1176	def_bool y
1177
1178config X86_MCE_INJECT
1179	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1180	tristate "Machine check injector support"
1181	---help---
1182	  Provide support for injecting machine checks for testing purposes.
1183	  If you don't know what a machine check is and you don't do kernel
1184	  QA it is safe to say n.
1185
1186config X86_THERMAL_VECTOR
1187	def_bool y
1188	depends on X86_MCE_INTEL
1189
1190source "arch/x86/events/Kconfig"
1191
1192config X86_LEGACY_VM86
1193	bool "Legacy VM86 support"
1194	depends on X86_32
1195	---help---
1196	  This option allows user programs to put the CPU into V8086
1197	  mode, which is an 80286-era approximation of 16-bit real mode.
1198
1199	  Some very old versions of X and/or vbetool require this option
1200	  for user mode setting.  Similarly, DOSEMU will use it if
1201	  available to accelerate real mode DOS programs.  However, any
1202	  recent version of DOSEMU, X, or vbetool should be fully
1203	  functional even without kernel VM86 support, as they will all
1204	  fall back to software emulation. Nevertheless, if you are using
1205	  a 16-bit DOS program where 16-bit performance matters, vm86
1206	  mode might be faster than emulation and you might want to
1207	  enable this option.
1208
1209	  Note that any app that works on a 64-bit kernel is unlikely to
1210	  need this option, as 64-bit kernels don't, and can't, support
1211	  V8086 mode. This option is also unrelated to 16-bit protected
1212	  mode and is not needed to run most 16-bit programs under Wine.
1213
1214	  Enabling this option increases the complexity of the kernel
1215	  and slows down exception handling a tiny bit.
1216
1217	  If unsure, say N here.
1218
1219config VM86
1220       bool
1221       default X86_LEGACY_VM86
1222
1223config X86_16BIT
1224	bool "Enable support for 16-bit segments" if EXPERT
1225	default y
1226	depends on MODIFY_LDT_SYSCALL
1227	---help---
1228	  This option is required by programs like Wine to run 16-bit
1229	  protected mode legacy code on x86 processors.  Disabling
1230	  this option saves about 300 bytes on i386, or around 6K text
1231	  plus 16K runtime memory on x86-64,
1232
1233config X86_ESPFIX32
1234	def_bool y
1235	depends on X86_16BIT && X86_32
1236
1237config X86_ESPFIX64
1238	def_bool y
1239	depends on X86_16BIT && X86_64
1240
1241config X86_VSYSCALL_EMULATION
1242       bool "Enable vsyscall emulation" if EXPERT
1243       default y
1244       depends on X86_64
1245       ---help---
1246	 This enables emulation of the legacy vsyscall page.  Disabling
1247	 it is roughly equivalent to booting with vsyscall=none, except
1248	 that it will also disable the helpful warning if a program
1249	 tries to use a vsyscall.  With this option set to N, offending
1250	 programs will just segfault, citing addresses of the form
1251	 0xffffffffff600?00.
1252
1253	 This option is required by many programs built before 2013, and
1254	 care should be used even with newer programs if set to N.
1255
1256	 Disabling this option saves about 7K of kernel size and
1257	 possibly 4K of additional runtime pagetable memory.
1258
1259config TOSHIBA
1260	tristate "Toshiba Laptop support"
1261	depends on X86_32
1262	---help---
1263	  This adds a driver to safely access the System Management Mode of
1264	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1265	  not work on models with a Phoenix BIOS. The System Management Mode
1266	  is used to set the BIOS and power saving options on Toshiba portables.
1267
1268	  For information on utilities to make use of this driver see the
1269	  Toshiba Linux utilities web site at:
1270	  <http://www.buzzard.org.uk/toshiba/>.
1271
1272	  Say Y if you intend to run this kernel on a Toshiba portable.
1273	  Say N otherwise.
1274
1275config I8K
1276	tristate "Dell i8k legacy laptop support"
1277	select HWMON
1278	select SENSORS_DELL_SMM
1279	---help---
1280	  This option enables legacy /proc/i8k userspace interface in hwmon
1281	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1282	  temperature and allows controlling fan speeds of Dell laptops via
1283	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1284	  it reports also power and hotkey status. For fan speed control is
1285	  needed userspace package i8kutils.
1286
1287	  Say Y if you intend to run this kernel on old Dell laptops or want to
1288	  use userspace package i8kutils.
1289	  Say N otherwise.
1290
1291config X86_REBOOTFIXUPS
1292	bool "Enable X86 board specific fixups for reboot"
1293	depends on X86_32
1294	---help---
1295	  This enables chipset and/or board specific fixups to be done
1296	  in order to get reboot to work correctly. This is only needed on
1297	  some combinations of hardware and BIOS. The symptom, for which
1298	  this config is intended, is when reboot ends with a stalled/hung
1299	  system.
1300
1301	  Currently, the only fixup is for the Geode machines using
1302	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1303
1304	  Say Y if you want to enable the fixup. Currently, it's safe to
1305	  enable this option even if you don't need it.
1306	  Say N otherwise.
1307
1308config MICROCODE
1309	bool "CPU microcode loading support"
1310	default y
1311	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1312	select FW_LOADER
1313	---help---
1314	  If you say Y here, you will be able to update the microcode on
1315	  Intel and AMD processors. The Intel support is for the IA32 family,
1316	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1317	  AMD support is for families 0x10 and later. You will obviously need
1318	  the actual microcode binary data itself which is not shipped with
1319	  the Linux kernel.
1320
1321	  The preferred method to load microcode from a detached initrd is described
1322	  in Documentation/x86/microcode.rst. For that you need to enable
1323	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1324	  initrd for microcode blobs.
1325
1326	  In addition, you can build the microcode into the kernel. For that you
1327	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1328	  config option.
1329
1330config MICROCODE_INTEL
1331	bool "Intel microcode loading support"
1332	depends on MICROCODE
1333	default MICROCODE
1334	select FW_LOADER
1335	---help---
1336	  This options enables microcode patch loading support for Intel
1337	  processors.
1338
1339	  For the current Intel microcode data package go to
1340	  <https://downloadcenter.intel.com> and search for
1341	  'Linux Processor Microcode Data File'.
1342
1343config MICROCODE_AMD
1344	bool "AMD microcode loading support"
1345	depends on MICROCODE
1346	select FW_LOADER
1347	---help---
1348	  If you select this option, microcode patch loading support for AMD
1349	  processors will be enabled.
1350
1351config MICROCODE_OLD_INTERFACE
1352	bool "Ancient loading interface (DEPRECATED)"
1353	default n
1354	depends on MICROCODE
1355	---help---
1356	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1357	  which was used by userspace tools like iucode_tool and microcode.ctl.
1358	  It is inadequate because it runs too late to be able to properly
1359	  load microcode on a machine and it needs special tools. Instead, you
1360	  should've switched to the early loading method with the initrd or
1361	  builtin microcode by now: Documentation/x86/microcode.rst
1362
1363config X86_MSR
1364	tristate "/dev/cpu/*/msr - Model-specific register support"
1365	---help---
1366	  This device gives privileged processes access to the x86
1367	  Model-Specific Registers (MSRs).  It is a character device with
1368	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1369	  MSR accesses are directed to a specific CPU on multi-processor
1370	  systems.
1371
1372config X86_CPUID
1373	tristate "/dev/cpu/*/cpuid - CPU information support"
1374	---help---
1375	  This device gives processes access to the x86 CPUID instruction to
1376	  be executed on a specific processor.  It is a character device
1377	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1378	  /dev/cpu/31/cpuid.
1379
1380choice
1381	prompt "High Memory Support"
1382	default HIGHMEM4G
1383	depends on X86_32
1384
1385config NOHIGHMEM
1386	bool "off"
1387	---help---
1388	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1389	  However, the address space of 32-bit x86 processors is only 4
1390	  Gigabytes large. That means that, if you have a large amount of
1391	  physical memory, not all of it can be "permanently mapped" by the
1392	  kernel. The physical memory that's not permanently mapped is called
1393	  "high memory".
1394
1395	  If you are compiling a kernel which will never run on a machine with
1396	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1397	  choice and suitable for most users). This will result in a "3GB/1GB"
1398	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1399	  space and the remaining part of the 4GB virtual memory space is used
1400	  by the kernel to permanently map as much physical memory as
1401	  possible.
1402
1403	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1404	  answer "4GB" here.
1405
1406	  If more than 4 Gigabytes is used then answer "64GB" here. This
1407	  selection turns Intel PAE (Physical Address Extension) mode on.
1408	  PAE implements 3-level paging on IA32 processors. PAE is fully
1409	  supported by Linux, PAE mode is implemented on all recent Intel
1410	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1411	  then the kernel will not boot on CPUs that don't support PAE!
1412
1413	  The actual amount of total physical memory will either be
1414	  auto detected or can be forced by using a kernel command line option
1415	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1416	  your boot loader (lilo or loadlin) about how to pass options to the
1417	  kernel at boot time.)
1418
1419	  If unsure, say "off".
1420
1421config HIGHMEM4G
1422	bool "4GB"
1423	---help---
1424	  Select this if you have a 32-bit processor and between 1 and 4
1425	  gigabytes of physical RAM.
1426
1427config HIGHMEM64G
1428	bool "64GB"
1429	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1430	select X86_PAE
1431	---help---
1432	  Select this if you have a 32-bit processor and more than 4
1433	  gigabytes of physical RAM.
1434
1435endchoice
1436
1437choice
1438	prompt "Memory split" if EXPERT
1439	default VMSPLIT_3G
1440	depends on X86_32
1441	---help---
1442	  Select the desired split between kernel and user memory.
1443
1444	  If the address range available to the kernel is less than the
1445	  physical memory installed, the remaining memory will be available
1446	  as "high memory". Accessing high memory is a little more costly
1447	  than low memory, as it needs to be mapped into the kernel first.
1448	  Note that increasing the kernel address space limits the range
1449	  available to user programs, making the address space there
1450	  tighter.  Selecting anything other than the default 3G/1G split
1451	  will also likely make your kernel incompatible with binary-only
1452	  kernel modules.
1453
1454	  If you are not absolutely sure what you are doing, leave this
1455	  option alone!
1456
1457	config VMSPLIT_3G
1458		bool "3G/1G user/kernel split"
1459	config VMSPLIT_3G_OPT
1460		depends on !X86_PAE
1461		bool "3G/1G user/kernel split (for full 1G low memory)"
1462	config VMSPLIT_2G
1463		bool "2G/2G user/kernel split"
1464	config VMSPLIT_2G_OPT
1465		depends on !X86_PAE
1466		bool "2G/2G user/kernel split (for full 2G low memory)"
1467	config VMSPLIT_1G
1468		bool "1G/3G user/kernel split"
1469endchoice
1470
1471config PAGE_OFFSET
1472	hex
1473	default 0xB0000000 if VMSPLIT_3G_OPT
1474	default 0x80000000 if VMSPLIT_2G
1475	default 0x78000000 if VMSPLIT_2G_OPT
1476	default 0x40000000 if VMSPLIT_1G
1477	default 0xC0000000
1478	depends on X86_32
1479
1480config HIGHMEM
1481	def_bool y
1482	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1483
1484config X86_PAE
1485	bool "PAE (Physical Address Extension) Support"
1486	depends on X86_32 && !HIGHMEM4G
1487	select PHYS_ADDR_T_64BIT
1488	select SWIOTLB
1489	---help---
1490	  PAE is required for NX support, and furthermore enables
1491	  larger swapspace support for non-overcommit purposes. It
1492	  has the cost of more pagetable lookup overhead, and also
1493	  consumes more pagetable space per process.
1494
1495config X86_5LEVEL
1496	bool "Enable 5-level page tables support"
1497	select DYNAMIC_MEMORY_LAYOUT
1498	select SPARSEMEM_VMEMMAP
1499	depends on X86_64
1500	---help---
1501	  5-level paging enables access to larger address space:
1502	  upto 128 PiB of virtual address space and 4 PiB of
1503	  physical address space.
1504
1505	  It will be supported by future Intel CPUs.
1506
1507	  A kernel with the option enabled can be booted on machines that
1508	  support 4- or 5-level paging.
1509
1510	  See Documentation/x86/x86_64/5level-paging.rst for more
1511	  information.
1512
1513	  Say N if unsure.
1514
1515config X86_DIRECT_GBPAGES
1516	def_bool y
1517	depends on X86_64
1518	---help---
1519	  Certain kernel features effectively disable kernel
1520	  linear 1 GB mappings (even if the CPU otherwise
1521	  supports them), so don't confuse the user by printing
1522	  that we have them enabled.
1523
1524config X86_CPA_STATISTICS
1525	bool "Enable statistic for Change Page Attribute"
1526	depends on DEBUG_FS
1527	---help---
1528	  Expose statistics about the Change Page Attribute mechanims, which
1529	  helps to determine the effectiveness of preserving large and huge
1530	  page mappings when mapping protections are changed.
1531
1532config AMD_MEM_ENCRYPT
1533	bool "AMD Secure Memory Encryption (SME) support"
1534	depends on X86_64 && CPU_SUP_AMD
1535	select DYNAMIC_PHYSICAL_MASK
1536	select ARCH_USE_MEMREMAP_PROT
1537	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1538	---help---
1539	  Say yes to enable support for the encryption of system memory.
1540	  This requires an AMD processor that supports Secure Memory
1541	  Encryption (SME).
1542
1543config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1544	bool "Activate AMD Secure Memory Encryption (SME) by default"
1545	default y
1546	depends on AMD_MEM_ENCRYPT
1547	---help---
1548	  Say yes to have system memory encrypted by default if running on
1549	  an AMD processor that supports Secure Memory Encryption (SME).
1550
1551	  If set to Y, then the encryption of system memory can be
1552	  deactivated with the mem_encrypt=off command line option.
1553
1554	  If set to N, then the encryption of system memory can be
1555	  activated with the mem_encrypt=on command line option.
1556
1557# Common NUMA Features
1558config NUMA
1559	bool "Numa Memory Allocation and Scheduler Support"
1560	depends on SMP
1561	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1562	default y if X86_BIGSMP
1563	---help---
1564	  Enable NUMA (Non Uniform Memory Access) support.
1565
1566	  The kernel will try to allocate memory used by a CPU on the
1567	  local memory controller of the CPU and add some more
1568	  NUMA awareness to the kernel.
1569
1570	  For 64-bit this is recommended if the system is Intel Core i7
1571	  (or later), AMD Opteron, or EM64T NUMA.
1572
1573	  For 32-bit this is only needed if you boot a 32-bit
1574	  kernel on a 64-bit NUMA platform.
1575
1576	  Otherwise, you should say N.
1577
1578config AMD_NUMA
1579	def_bool y
1580	prompt "Old style AMD Opteron NUMA detection"
1581	depends on X86_64 && NUMA && PCI
1582	---help---
1583	  Enable AMD NUMA node topology detection.  You should say Y here if
1584	  you have a multi processor AMD system. This uses an old method to
1585	  read the NUMA configuration directly from the builtin Northbridge
1586	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1587	  which also takes priority if both are compiled in.
1588
1589config X86_64_ACPI_NUMA
1590	def_bool y
1591	prompt "ACPI NUMA detection"
1592	depends on X86_64 && NUMA && ACPI && PCI
1593	select ACPI_NUMA
1594	---help---
1595	  Enable ACPI SRAT based node topology detection.
1596
1597# Some NUMA nodes have memory ranges that span
1598# other nodes.  Even though a pfn is valid and
1599# between a node's start and end pfns, it may not
1600# reside on that node.  See memmap_init_zone()
1601# for details.
1602config NODES_SPAN_OTHER_NODES
1603	def_bool y
1604	depends on X86_64_ACPI_NUMA
1605
1606config NUMA_EMU
1607	bool "NUMA emulation"
1608	depends on NUMA
1609	---help---
1610	  Enable NUMA emulation. A flat machine will be split
1611	  into virtual nodes when booted with "numa=fake=N", where N is the
1612	  number of nodes. This is only useful for debugging.
1613
1614config NODES_SHIFT
1615	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1616	range 1 10
1617	default "10" if MAXSMP
1618	default "6" if X86_64
1619	default "3"
1620	depends on NEED_MULTIPLE_NODES
1621	---help---
1622	  Specify the maximum number of NUMA Nodes available on the target
1623	  system.  Increases memory reserved to accommodate various tables.
1624
1625config ARCH_HAVE_MEMORY_PRESENT
1626	def_bool y
1627	depends on X86_32 && DISCONTIGMEM
1628
1629config ARCH_FLATMEM_ENABLE
1630	def_bool y
1631	depends on X86_32 && !NUMA
1632
1633config ARCH_DISCONTIGMEM_ENABLE
1634	def_bool n
1635	depends on NUMA && X86_32
1636	depends on BROKEN
1637
1638config ARCH_SPARSEMEM_ENABLE
1639	def_bool y
1640	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1641	select SPARSEMEM_STATIC if X86_32
1642	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1643
1644config ARCH_SPARSEMEM_DEFAULT
1645	def_bool X86_64 || (NUMA && X86_32)
1646
1647config ARCH_SELECT_MEMORY_MODEL
1648	def_bool y
1649	depends on ARCH_SPARSEMEM_ENABLE
1650
1651config ARCH_MEMORY_PROBE
1652	bool "Enable sysfs memory/probe interface"
1653	depends on X86_64 && MEMORY_HOTPLUG
1654	help
1655	  This option enables a sysfs memory/probe interface for testing.
1656	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1657	  If you are unsure how to answer this question, answer N.
1658
1659config ARCH_PROC_KCORE_TEXT
1660	def_bool y
1661	depends on X86_64 && PROC_KCORE
1662
1663config ILLEGAL_POINTER_VALUE
1664       hex
1665       default 0 if X86_32
1666       default 0xdead000000000000 if X86_64
1667
1668config X86_PMEM_LEGACY_DEVICE
1669	bool
1670
1671config X86_PMEM_LEGACY
1672	tristate "Support non-standard NVDIMMs and ADR protected memory"
1673	depends on PHYS_ADDR_T_64BIT
1674	depends on BLK_DEV
1675	select X86_PMEM_LEGACY_DEVICE
1676	select LIBNVDIMM
1677	help
1678	  Treat memory marked using the non-standard e820 type of 12 as used
1679	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1680	  The kernel will offer these regions to the 'pmem' driver so
1681	  they can be used for persistent storage.
1682
1683	  Say Y if unsure.
1684
1685config HIGHPTE
1686	bool "Allocate 3rd-level pagetables from highmem"
1687	depends on HIGHMEM
1688	---help---
1689	  The VM uses one page table entry for each page of physical memory.
1690	  For systems with a lot of RAM, this can be wasteful of precious
1691	  low memory.  Setting this option will put user-space page table
1692	  entries in high memory.
1693
1694config X86_CHECK_BIOS_CORRUPTION
1695	bool "Check for low memory corruption"
1696	---help---
1697	  Periodically check for memory corruption in low memory, which
1698	  is suspected to be caused by BIOS.  Even when enabled in the
1699	  configuration, it is disabled at runtime.  Enable it by
1700	  setting "memory_corruption_check=1" on the kernel command
1701	  line.  By default it scans the low 64k of memory every 60
1702	  seconds; see the memory_corruption_check_size and
1703	  memory_corruption_check_period parameters in
1704	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1705
1706	  When enabled with the default parameters, this option has
1707	  almost no overhead, as it reserves a relatively small amount
1708	  of memory and scans it infrequently.  It both detects corruption
1709	  and prevents it from affecting the running system.
1710
1711	  It is, however, intended as a diagnostic tool; if repeatable
1712	  BIOS-originated corruption always affects the same memory,
1713	  you can use memmap= to prevent the kernel from using that
1714	  memory.
1715
1716config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1717	bool "Set the default setting of memory_corruption_check"
1718	depends on X86_CHECK_BIOS_CORRUPTION
1719	default y
1720	---help---
1721	  Set whether the default state of memory_corruption_check is
1722	  on or off.
1723
1724config X86_RESERVE_LOW
1725	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1726	default 64
1727	range 4 640
1728	---help---
1729	  Specify the amount of low memory to reserve for the BIOS.
1730
1731	  The first page contains BIOS data structures that the kernel
1732	  must not use, so that page must always be reserved.
1733
1734	  By default we reserve the first 64K of physical RAM, as a
1735	  number of BIOSes are known to corrupt that memory range
1736	  during events such as suspend/resume or monitor cable
1737	  insertion, so it must not be used by the kernel.
1738
1739	  You can set this to 4 if you are absolutely sure that you
1740	  trust the BIOS to get all its memory reservations and usages
1741	  right.  If you know your BIOS have problems beyond the
1742	  default 64K area, you can set this to 640 to avoid using the
1743	  entire low memory range.
1744
1745	  If you have doubts about the BIOS (e.g. suspend/resume does
1746	  not work or there's kernel crashes after certain hardware
1747	  hotplug events) then you might want to enable
1748	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1749	  typical corruption patterns.
1750
1751	  Leave this to the default value of 64 if you are unsure.
1752
1753config MATH_EMULATION
1754	bool
1755	depends on MODIFY_LDT_SYSCALL
1756	prompt "Math emulation" if X86_32
1757	---help---
1758	  Linux can emulate a math coprocessor (used for floating point
1759	  operations) if you don't have one. 486DX and Pentium processors have
1760	  a math coprocessor built in, 486SX and 386 do not, unless you added
1761	  a 487DX or 387, respectively. (The messages during boot time can
1762	  give you some hints here ["man dmesg"].) Everyone needs either a
1763	  coprocessor or this emulation.
1764
1765	  If you don't have a math coprocessor, you need to say Y here; if you
1766	  say Y here even though you have a coprocessor, the coprocessor will
1767	  be used nevertheless. (This behavior can be changed with the kernel
1768	  command line option "no387", which comes handy if your coprocessor
1769	  is broken. Try "man bootparam" or see the documentation of your boot
1770	  loader (lilo or loadlin) about how to pass options to the kernel at
1771	  boot time.) This means that it is a good idea to say Y here if you
1772	  intend to use this kernel on different machines.
1773
1774	  More information about the internals of the Linux math coprocessor
1775	  emulation can be found in <file:arch/x86/math-emu/README>.
1776
1777	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1778	  kernel, it won't hurt.
1779
1780config MTRR
1781	def_bool y
1782	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1783	---help---
1784	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1785	  the Memory Type Range Registers (MTRRs) may be used to control
1786	  processor access to memory ranges. This is most useful if you have
1787	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1788	  allows bus write transfers to be combined into a larger transfer
1789	  before bursting over the PCI/AGP bus. This can increase performance
1790	  of image write operations 2.5 times or more. Saying Y here creates a
1791	  /proc/mtrr file which may be used to manipulate your processor's
1792	  MTRRs. Typically the X server should use this.
1793
1794	  This code has a reasonably generic interface so that similar
1795	  control registers on other processors can be easily supported
1796	  as well:
1797
1798	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1799	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1800	  these, the ARRs are used to emulate the MTRRs.
1801	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1802	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1803	  write-combining. All of these processors are supported by this code
1804	  and it makes sense to say Y here if you have one of them.
1805
1806	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1807	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1808	  can lead to all sorts of problems, so it's good to say Y here.
1809
1810	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1811	  just add about 9 KB to your kernel.
1812
1813	  See <file:Documentation/x86/mtrr.rst> for more information.
1814
1815config MTRR_SANITIZER
1816	def_bool y
1817	prompt "MTRR cleanup support"
1818	depends on MTRR
1819	---help---
1820	  Convert MTRR layout from continuous to discrete, so X drivers can
1821	  add writeback entries.
1822
1823	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1824	  The largest mtrr entry size for a continuous block can be set with
1825	  mtrr_chunk_size.
1826
1827	  If unsure, say Y.
1828
1829config MTRR_SANITIZER_ENABLE_DEFAULT
1830	int "MTRR cleanup enable value (0-1)"
1831	range 0 1
1832	default "0"
1833	depends on MTRR_SANITIZER
1834	---help---
1835	  Enable mtrr cleanup default value
1836
1837config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1838	int "MTRR cleanup spare reg num (0-7)"
1839	range 0 7
1840	default "1"
1841	depends on MTRR_SANITIZER
1842	---help---
1843	  mtrr cleanup spare entries default, it can be changed via
1844	  mtrr_spare_reg_nr=N on the kernel command line.
1845
1846config X86_PAT
1847	def_bool y
1848	prompt "x86 PAT support" if EXPERT
1849	depends on MTRR
1850	---help---
1851	  Use PAT attributes to setup page level cache control.
1852
1853	  PATs are the modern equivalents of MTRRs and are much more
1854	  flexible than MTRRs.
1855
1856	  Say N here if you see bootup problems (boot crash, boot hang,
1857	  spontaneous reboots) or a non-working video driver.
1858
1859	  If unsure, say Y.
1860
1861config ARCH_USES_PG_UNCACHED
1862	def_bool y
1863	depends on X86_PAT
1864
1865config ARCH_RANDOM
1866	def_bool y
1867	prompt "x86 architectural random number generator" if EXPERT
1868	---help---
1869	  Enable the x86 architectural RDRAND instruction
1870	  (Intel Bull Mountain technology) to generate random numbers.
1871	  If supported, this is a high bandwidth, cryptographically
1872	  secure hardware random number generator.
1873
1874config X86_SMAP
1875	def_bool y
1876	prompt "Supervisor Mode Access Prevention" if EXPERT
1877	---help---
1878	  Supervisor Mode Access Prevention (SMAP) is a security
1879	  feature in newer Intel processors.  There is a small
1880	  performance cost if this enabled and turned on; there is
1881	  also a small increase in the kernel size if this is enabled.
1882
1883	  If unsure, say Y.
1884
1885config X86_INTEL_UMIP
1886	def_bool y
1887	depends on CPU_SUP_INTEL
1888	prompt "Intel User Mode Instruction Prevention" if EXPERT
1889	---help---
1890	  The User Mode Instruction Prevention (UMIP) is a security
1891	  feature in newer Intel processors. If enabled, a general
1892	  protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1893	  or STR instructions are executed in user mode. These instructions
1894	  unnecessarily expose information about the hardware state.
1895
1896	  The vast majority of applications do not use these instructions.
1897	  For the very few that do, software emulation is provided in
1898	  specific cases in protected and virtual-8086 modes. Emulated
1899	  results are dummy.
1900
1901config X86_INTEL_MPX
1902	prompt "Intel MPX (Memory Protection Extensions)"
1903	def_bool n
1904	# Note: only available in 64-bit mode due to VMA flags shortage
1905	depends on CPU_SUP_INTEL && X86_64
1906	select ARCH_USES_HIGH_VMA_FLAGS
1907	---help---
1908	  MPX provides hardware features that can be used in
1909	  conjunction with compiler-instrumented code to check
1910	  memory references.  It is designed to detect buffer
1911	  overflow or underflow bugs.
1912
1913	  This option enables running applications which are
1914	  instrumented or otherwise use MPX.  It does not use MPX
1915	  itself inside the kernel or to protect the kernel
1916	  against bad memory references.
1917
1918	  Enabling this option will make the kernel larger:
1919	  ~8k of kernel text and 36 bytes of data on a 64-bit
1920	  defconfig.  It adds a long to the 'mm_struct' which
1921	  will increase the kernel memory overhead of each
1922	  process and adds some branches to paths used during
1923	  exec() and munmap().
1924
1925	  For details, see Documentation/x86/intel_mpx.rst
1926
1927	  If unsure, say N.
1928
1929config X86_INTEL_MEMORY_PROTECTION_KEYS
1930	prompt "Intel Memory Protection Keys"
1931	def_bool y
1932	# Note: only available in 64-bit mode
1933	depends on CPU_SUP_INTEL && X86_64
1934	select ARCH_USES_HIGH_VMA_FLAGS
1935	select ARCH_HAS_PKEYS
1936	---help---
1937	  Memory Protection Keys provides a mechanism for enforcing
1938	  page-based protections, but without requiring modification of the
1939	  page tables when an application changes protection domains.
1940
1941	  For details, see Documentation/core-api/protection-keys.rst
1942
1943	  If unsure, say y.
1944
1945choice
1946	prompt "TSX enable mode"
1947	depends on CPU_SUP_INTEL
1948	default X86_INTEL_TSX_MODE_OFF
1949	help
1950	  Intel's TSX (Transactional Synchronization Extensions) feature
1951	  allows to optimize locking protocols through lock elision which
1952	  can lead to a noticeable performance boost.
1953
1954	  On the other hand it has been shown that TSX can be exploited
1955	  to form side channel attacks (e.g. TAA) and chances are there
1956	  will be more of those attacks discovered in the future.
1957
1958	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1959	  might override this decision by tsx=on the command line parameter.
1960	  Even with TSX enabled, the kernel will attempt to enable the best
1961	  possible TAA mitigation setting depending on the microcode available
1962	  for the particular machine.
1963
1964	  This option allows to set the default tsx mode between tsx=on, =off
1965	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1966	  details.
1967
1968	  Say off if not sure, auto if TSX is in use but it should be used on safe
1969	  platforms or on if TSX is in use and the security aspect of tsx is not
1970	  relevant.
1971
1972config X86_INTEL_TSX_MODE_OFF
1973	bool "off"
1974	help
1975	  TSX is disabled if possible - equals to tsx=off command line parameter.
1976
1977config X86_INTEL_TSX_MODE_ON
1978	bool "on"
1979	help
1980	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1981	  line parameter.
1982
1983config X86_INTEL_TSX_MODE_AUTO
1984	bool "auto"
1985	help
1986	  TSX is enabled on TSX capable HW that is believed to be safe against
1987	  side channel attacks- equals the tsx=auto command line parameter.
1988endchoice
1989
1990config EFI
1991	bool "EFI runtime service support"
1992	depends on ACPI
1993	select UCS2_STRING
1994	select EFI_RUNTIME_WRAPPERS
1995	---help---
1996	  This enables the kernel to use EFI runtime services that are
1997	  available (such as the EFI variable services).
1998
1999	  This option is only useful on systems that have EFI firmware.
2000	  In addition, you should use the latest ELILO loader available
2001	  at <http://elilo.sourceforge.net> in order to take advantage
2002	  of EFI runtime services. However, even with this option, the
2003	  resultant kernel should continue to boot on existing non-EFI
2004	  platforms.
2005
2006config EFI_STUB
2007       bool "EFI stub support"
2008       depends on EFI && !X86_USE_3DNOW
2009       select RELOCATABLE
2010       ---help---
2011          This kernel feature allows a bzImage to be loaded directly
2012	  by EFI firmware without the use of a bootloader.
2013
2014	  See Documentation/admin-guide/efi-stub.rst for more information.
2015
2016config EFI_MIXED
2017	bool "EFI mixed-mode support"
2018	depends on EFI_STUB && X86_64
2019	---help---
2020	   Enabling this feature allows a 64-bit kernel to be booted
2021	   on a 32-bit firmware, provided that your CPU supports 64-bit
2022	   mode.
2023
2024	   Note that it is not possible to boot a mixed-mode enabled
2025	   kernel via the EFI boot stub - a bootloader that supports
2026	   the EFI handover protocol must be used.
2027
2028	   If unsure, say N.
2029
2030config SECCOMP
2031	def_bool y
2032	prompt "Enable seccomp to safely compute untrusted bytecode"
2033	---help---
2034	  This kernel feature is useful for number crunching applications
2035	  that may need to compute untrusted bytecode during their
2036	  execution. By using pipes or other transports made available to
2037	  the process as file descriptors supporting the read/write
2038	  syscalls, it's possible to isolate those applications in
2039	  their own address space using seccomp. Once seccomp is
2040	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
2041	  and the task is only allowed to execute a few safe syscalls
2042	  defined by each seccomp mode.
2043
2044	  If unsure, say Y. Only embedded should say N here.
2045
2046source "kernel/Kconfig.hz"
2047
2048config KEXEC
2049	bool "kexec system call"
2050	select KEXEC_CORE
2051	---help---
2052	  kexec is a system call that implements the ability to shutdown your
2053	  current kernel, and to start another kernel.  It is like a reboot
2054	  but it is independent of the system firmware.   And like a reboot
2055	  you can start any kernel with it, not just Linux.
2056
2057	  The name comes from the similarity to the exec system call.
2058
2059	  It is an ongoing process to be certain the hardware in a machine
2060	  is properly shutdown, so do not be surprised if this code does not
2061	  initially work for you.  As of this writing the exact hardware
2062	  interface is strongly in flux, so no good recommendation can be
2063	  made.
2064
2065config KEXEC_FILE
2066	bool "kexec file based system call"
2067	select KEXEC_CORE
2068	select BUILD_BIN2C
2069	depends on X86_64
2070	depends on CRYPTO=y
2071	depends on CRYPTO_SHA256=y
2072	---help---
2073	  This is new version of kexec system call. This system call is
2074	  file based and takes file descriptors as system call argument
2075	  for kernel and initramfs as opposed to list of segments as
2076	  accepted by previous system call.
2077
2078config ARCH_HAS_KEXEC_PURGATORY
2079	def_bool KEXEC_FILE
2080
2081config KEXEC_SIG
2082	bool "Verify kernel signature during kexec_file_load() syscall"
2083	depends on KEXEC_FILE
2084	---help---
2085
2086	  This option makes the kexec_file_load() syscall check for a valid
2087	  signature of the kernel image.  The image can still be loaded without
2088	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2089	  there's a signature that we can check, then it must be valid.
2090
2091	  In addition to this option, you need to enable signature
2092	  verification for the corresponding kernel image type being
2093	  loaded in order for this to work.
2094
2095config KEXEC_SIG_FORCE
2096	bool "Require a valid signature in kexec_file_load() syscall"
2097	depends on KEXEC_SIG
2098	---help---
2099	  This option makes kernel signature verification mandatory for
2100	  the kexec_file_load() syscall.
2101
2102config KEXEC_BZIMAGE_VERIFY_SIG
2103	bool "Enable bzImage signature verification support"
2104	depends on KEXEC_SIG
2105	depends on SIGNED_PE_FILE_VERIFICATION
2106	select SYSTEM_TRUSTED_KEYRING
2107	---help---
2108	  Enable bzImage signature verification support.
2109
2110config CRASH_DUMP
2111	bool "kernel crash dumps"
2112	depends on X86_64 || (X86_32 && HIGHMEM)
2113	---help---
2114	  Generate crash dump after being started by kexec.
2115	  This should be normally only set in special crash dump kernels
2116	  which are loaded in the main kernel with kexec-tools into
2117	  a specially reserved region and then later executed after
2118	  a crash by kdump/kexec. The crash dump kernel must be compiled
2119	  to a memory address not used by the main kernel or BIOS using
2120	  PHYSICAL_START, or it must be built as a relocatable image
2121	  (CONFIG_RELOCATABLE=y).
2122	  For more details see Documentation/admin-guide/kdump/kdump.rst
2123
2124config KEXEC_JUMP
2125	bool "kexec jump"
2126	depends on KEXEC && HIBERNATION
2127	---help---
2128	  Jump between original kernel and kexeced kernel and invoke
2129	  code in physical address mode via KEXEC
2130
2131config PHYSICAL_START
2132	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2133	default "0x1000000"
2134	---help---
2135	  This gives the physical address where the kernel is loaded.
2136
2137	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2138	  bzImage will decompress itself to above physical address and
2139	  run from there. Otherwise, bzImage will run from the address where
2140	  it has been loaded by the boot loader and will ignore above physical
2141	  address.
2142
2143	  In normal kdump cases one does not have to set/change this option
2144	  as now bzImage can be compiled as a completely relocatable image
2145	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2146	  address. This option is mainly useful for the folks who don't want
2147	  to use a bzImage for capturing the crash dump and want to use a
2148	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2149	  to be specifically compiled to run from a specific memory area
2150	  (normally a reserved region) and this option comes handy.
2151
2152	  So if you are using bzImage for capturing the crash dump,
2153	  leave the value here unchanged to 0x1000000 and set
2154	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2155	  for capturing the crash dump change this value to start of
2156	  the reserved region.  In other words, it can be set based on
2157	  the "X" value as specified in the "crashkernel=YM@XM"
2158	  command line boot parameter passed to the panic-ed
2159	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2160	  for more details about crash dumps.
2161
2162	  Usage of bzImage for capturing the crash dump is recommended as
2163	  one does not have to build two kernels. Same kernel can be used
2164	  as production kernel and capture kernel. Above option should have
2165	  gone away after relocatable bzImage support is introduced. But it
2166	  is present because there are users out there who continue to use
2167	  vmlinux for dump capture. This option should go away down the
2168	  line.
2169
2170	  Don't change this unless you know what you are doing.
2171
2172config RELOCATABLE
2173	bool "Build a relocatable kernel"
2174	default y
2175	---help---
2176	  This builds a kernel image that retains relocation information
2177	  so it can be loaded someplace besides the default 1MB.
2178	  The relocations tend to make the kernel binary about 10% larger,
2179	  but are discarded at runtime.
2180
2181	  One use is for the kexec on panic case where the recovery kernel
2182	  must live at a different physical address than the primary
2183	  kernel.
2184
2185	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2186	  it has been loaded at and the compile time physical address
2187	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2188
2189config RANDOMIZE_BASE
2190	bool "Randomize the address of the kernel image (KASLR)"
2191	depends on RELOCATABLE
2192	default y
2193	---help---
2194	  In support of Kernel Address Space Layout Randomization (KASLR),
2195	  this randomizes the physical address at which the kernel image
2196	  is decompressed and the virtual address where the kernel
2197	  image is mapped, as a security feature that deters exploit
2198	  attempts relying on knowledge of the location of kernel
2199	  code internals.
2200
2201	  On 64-bit, the kernel physical and virtual addresses are
2202	  randomized separately. The physical address will be anywhere
2203	  between 16MB and the top of physical memory (up to 64TB). The
2204	  virtual address will be randomized from 16MB up to 1GB (9 bits
2205	  of entropy). Note that this also reduces the memory space
2206	  available to kernel modules from 1.5GB to 1GB.
2207
2208	  On 32-bit, the kernel physical and virtual addresses are
2209	  randomized together. They will be randomized from 16MB up to
2210	  512MB (8 bits of entropy).
2211
2212	  Entropy is generated using the RDRAND instruction if it is
2213	  supported. If RDTSC is supported, its value is mixed into
2214	  the entropy pool as well. If neither RDRAND nor RDTSC are
2215	  supported, then entropy is read from the i8254 timer. The
2216	  usable entropy is limited by the kernel being built using
2217	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2218	  minimum of 2MB. As a result, only 10 bits of entropy are
2219	  theoretically possible, but the implementations are further
2220	  limited due to memory layouts.
2221
2222	  If unsure, say Y.
2223
2224# Relocation on x86 needs some additional build support
2225config X86_NEED_RELOCS
2226	def_bool y
2227	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2228
2229config PHYSICAL_ALIGN
2230	hex "Alignment value to which kernel should be aligned"
2231	default "0x200000"
2232	range 0x2000 0x1000000 if X86_32
2233	range 0x200000 0x1000000 if X86_64
2234	---help---
2235	  This value puts the alignment restrictions on physical address
2236	  where kernel is loaded and run from. Kernel is compiled for an
2237	  address which meets above alignment restriction.
2238
2239	  If bootloader loads the kernel at a non-aligned address and
2240	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2241	  address aligned to above value and run from there.
2242
2243	  If bootloader loads the kernel at a non-aligned address and
2244	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2245	  load address and decompress itself to the address it has been
2246	  compiled for and run from there. The address for which kernel is
2247	  compiled already meets above alignment restrictions. Hence the
2248	  end result is that kernel runs from a physical address meeting
2249	  above alignment restrictions.
2250
2251	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2252	  this value must be a multiple of 0x200000.
2253
2254	  Don't change this unless you know what you are doing.
2255
2256config DYNAMIC_MEMORY_LAYOUT
2257	bool
2258	---help---
2259	  This option makes base addresses of vmalloc and vmemmap as well as
2260	  __PAGE_OFFSET movable during boot.
2261
2262config RANDOMIZE_MEMORY
2263	bool "Randomize the kernel memory sections"
2264	depends on X86_64
2265	depends on RANDOMIZE_BASE
2266	select DYNAMIC_MEMORY_LAYOUT
2267	default RANDOMIZE_BASE
2268	---help---
2269	   Randomizes the base virtual address of kernel memory sections
2270	   (physical memory mapping, vmalloc & vmemmap). This security feature
2271	   makes exploits relying on predictable memory locations less reliable.
2272
2273	   The order of allocations remains unchanged. Entropy is generated in
2274	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2275	   configuration have in average 30,000 different possible virtual
2276	   addresses for each memory section.
2277
2278	   If unsure, say Y.
2279
2280config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2281	hex "Physical memory mapping padding" if EXPERT
2282	depends on RANDOMIZE_MEMORY
2283	default "0xa" if MEMORY_HOTPLUG
2284	default "0x0"
2285	range 0x1 0x40 if MEMORY_HOTPLUG
2286	range 0x0 0x40
2287	---help---
2288	   Define the padding in terabytes added to the existing physical
2289	   memory size during kernel memory randomization. It is useful
2290	   for memory hotplug support but reduces the entropy available for
2291	   address randomization.
2292
2293	   If unsure, leave at the default value.
2294
2295config HOTPLUG_CPU
2296	def_bool y
2297	depends on SMP
2298
2299config BOOTPARAM_HOTPLUG_CPU0
2300	bool "Set default setting of cpu0_hotpluggable"
2301	depends on HOTPLUG_CPU
2302	---help---
2303	  Set whether default state of cpu0_hotpluggable is on or off.
2304
2305	  Say Y here to enable CPU0 hotplug by default. If this switch
2306	  is turned on, there is no need to give cpu0_hotplug kernel
2307	  parameter and the CPU0 hotplug feature is enabled by default.
2308
2309	  Please note: there are two known CPU0 dependencies if you want
2310	  to enable the CPU0 hotplug feature either by this switch or by
2311	  cpu0_hotplug kernel parameter.
2312
2313	  First, resume from hibernate or suspend always starts from CPU0.
2314	  So hibernate and suspend are prevented if CPU0 is offline.
2315
2316	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2317	  offline if any interrupt can not migrate out of CPU0. There may
2318	  be other CPU0 dependencies.
2319
2320	  Please make sure the dependencies are under your control before
2321	  you enable this feature.
2322
2323	  Say N if you don't want to enable CPU0 hotplug feature by default.
2324	  You still can enable the CPU0 hotplug feature at boot by kernel
2325	  parameter cpu0_hotplug.
2326
2327config DEBUG_HOTPLUG_CPU0
2328	def_bool n
2329	prompt "Debug CPU0 hotplug"
2330	depends on HOTPLUG_CPU
2331	---help---
2332	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2333	  soon as possible and boots up userspace with CPU0 offlined. User
2334	  can online CPU0 back after boot time.
2335
2336	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2337	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2338	  compilation or giving cpu0_hotplug kernel parameter at boot.
2339
2340	  If unsure, say N.
2341
2342config COMPAT_VDSO
2343	def_bool n
2344	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2345	depends on COMPAT_32
2346	---help---
2347	  Certain buggy versions of glibc will crash if they are
2348	  presented with a 32-bit vDSO that is not mapped at the address
2349	  indicated in its segment table.
2350
2351	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2352	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2353	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2354	  the only released version with the bug, but OpenSUSE 9
2355	  contains a buggy "glibc 2.3.2".
2356
2357	  The symptom of the bug is that everything crashes on startup, saying:
2358	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2359
2360	  Saying Y here changes the default value of the vdso32 boot
2361	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2362	  This works around the glibc bug but hurts performance.
2363
2364	  If unsure, say N: if you are compiling your own kernel, you
2365	  are unlikely to be using a buggy version of glibc.
2366
2367choice
2368	prompt "vsyscall table for legacy applications"
2369	depends on X86_64
2370	default LEGACY_VSYSCALL_XONLY
2371	help
2372	  Legacy user code that does not know how to find the vDSO expects
2373	  to be able to issue three syscalls by calling fixed addresses in
2374	  kernel space. Since this location is not randomized with ASLR,
2375	  it can be used to assist security vulnerability exploitation.
2376
2377	  This setting can be changed at boot time via the kernel command
2378	  line parameter vsyscall=[emulate|xonly|none].
2379
2380	  On a system with recent enough glibc (2.14 or newer) and no
2381	  static binaries, you can say None without a performance penalty
2382	  to improve security.
2383
2384	  If unsure, select "Emulate execution only".
2385
2386	config LEGACY_VSYSCALL_EMULATE
2387		bool "Full emulation"
2388		help
2389		  The kernel traps and emulates calls into the fixed vsyscall
2390		  address mapping. This makes the mapping non-executable, but
2391		  it still contains readable known contents, which could be
2392		  used in certain rare security vulnerability exploits. This
2393		  configuration is recommended when using legacy userspace
2394		  that still uses vsyscalls along with legacy binary
2395		  instrumentation tools that require code to be readable.
2396
2397		  An example of this type of legacy userspace is running
2398		  Pin on an old binary that still uses vsyscalls.
2399
2400	config LEGACY_VSYSCALL_XONLY
2401		bool "Emulate execution only"
2402		help
2403		  The kernel traps and emulates calls into the fixed vsyscall
2404		  address mapping and does not allow reads.  This
2405		  configuration is recommended when userspace might use the
2406		  legacy vsyscall area but support for legacy binary
2407		  instrumentation of legacy code is not needed.  It mitigates
2408		  certain uses of the vsyscall area as an ASLR-bypassing
2409		  buffer.
2410
2411	config LEGACY_VSYSCALL_NONE
2412		bool "None"
2413		help
2414		  There will be no vsyscall mapping at all. This will
2415		  eliminate any risk of ASLR bypass due to the vsyscall
2416		  fixed address mapping. Attempts to use the vsyscalls
2417		  will be reported to dmesg, so that either old or
2418		  malicious userspace programs can be identified.
2419
2420endchoice
2421
2422config CMDLINE_BOOL
2423	bool "Built-in kernel command line"
2424	---help---
2425	  Allow for specifying boot arguments to the kernel at
2426	  build time.  On some systems (e.g. embedded ones), it is
2427	  necessary or convenient to provide some or all of the
2428	  kernel boot arguments with the kernel itself (that is,
2429	  to not rely on the boot loader to provide them.)
2430
2431	  To compile command line arguments into the kernel,
2432	  set this option to 'Y', then fill in the
2433	  boot arguments in CONFIG_CMDLINE.
2434
2435	  Systems with fully functional boot loaders (i.e. non-embedded)
2436	  should leave this option set to 'N'.
2437
2438config CMDLINE
2439	string "Built-in kernel command string"
2440	depends on CMDLINE_BOOL
2441	default ""
2442	---help---
2443	  Enter arguments here that should be compiled into the kernel
2444	  image and used at boot time.  If the boot loader provides a
2445	  command line at boot time, it is appended to this string to
2446	  form the full kernel command line, when the system boots.
2447
2448	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2449	  change this behavior.
2450
2451	  In most cases, the command line (whether built-in or provided
2452	  by the boot loader) should specify the device for the root
2453	  file system.
2454
2455config CMDLINE_OVERRIDE
2456	bool "Built-in command line overrides boot loader arguments"
2457	depends on CMDLINE_BOOL
2458	---help---
2459	  Set this option to 'Y' to have the kernel ignore the boot loader
2460	  command line, and use ONLY the built-in command line.
2461
2462	  This is used to work around broken boot loaders.  This should
2463	  be set to 'N' under normal conditions.
2464
2465config MODIFY_LDT_SYSCALL
2466	bool "Enable the LDT (local descriptor table)" if EXPERT
2467	default y
2468	---help---
2469	  Linux can allow user programs to install a per-process x86
2470	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2471	  call.  This is required to run 16-bit or segmented code such as
2472	  DOSEMU or some Wine programs.  It is also used by some very old
2473	  threading libraries.
2474
2475	  Enabling this feature adds a small amount of overhead to
2476	  context switches and increases the low-level kernel attack
2477	  surface.  Disabling it removes the modify_ldt(2) system call.
2478
2479	  Saying 'N' here may make sense for embedded or server kernels.
2480
2481source "kernel/livepatch/Kconfig"
2482
2483endmenu
2484
2485config ARCH_HAS_ADD_PAGES
2486	def_bool y
2487	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2488
2489config ARCH_ENABLE_MEMORY_HOTPLUG
2490	def_bool y
2491	depends on X86_64 || (X86_32 && HIGHMEM)
2492
2493config ARCH_ENABLE_MEMORY_HOTREMOVE
2494	def_bool y
2495	depends on MEMORY_HOTPLUG
2496
2497config USE_PERCPU_NUMA_NODE_ID
2498	def_bool y
2499	depends on NUMA
2500
2501config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2502	def_bool y
2503	depends on X86_64 || X86_PAE
2504
2505config ARCH_ENABLE_HUGEPAGE_MIGRATION
2506	def_bool y
2507	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2508
2509config ARCH_ENABLE_THP_MIGRATION
2510	def_bool y
2511	depends on X86_64 && TRANSPARENT_HUGEPAGE
2512
2513menu "Power management and ACPI options"
2514
2515config ARCH_HIBERNATION_HEADER
2516	def_bool y
2517	depends on HIBERNATION
2518
2519source "kernel/power/Kconfig"
2520
2521source "drivers/acpi/Kconfig"
2522
2523source "drivers/sfi/Kconfig"
2524
2525config X86_APM_BOOT
2526	def_bool y
2527	depends on APM
2528
2529menuconfig APM
2530	tristate "APM (Advanced Power Management) BIOS support"
2531	depends on X86_32 && PM_SLEEP
2532	---help---
2533	  APM is a BIOS specification for saving power using several different
2534	  techniques. This is mostly useful for battery powered laptops with
2535	  APM compliant BIOSes. If you say Y here, the system time will be
2536	  reset after a RESUME operation, the /proc/apm device will provide
2537	  battery status information, and user-space programs will receive
2538	  notification of APM "events" (e.g. battery status change).
2539
2540	  If you select "Y" here, you can disable actual use of the APM
2541	  BIOS by passing the "apm=off" option to the kernel at boot time.
2542
2543	  Note that the APM support is almost completely disabled for
2544	  machines with more than one CPU.
2545
2546	  In order to use APM, you will need supporting software. For location
2547	  and more information, read <file:Documentation/power/apm-acpi.rst>
2548	  and the Battery Powered Linux mini-HOWTO, available from
2549	  <http://www.tldp.org/docs.html#howto>.
2550
2551	  This driver does not spin down disk drives (see the hdparm(8)
2552	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2553	  VESA-compliant "green" monitors.
2554
2555	  This driver does not support the TI 4000M TravelMate and the ACER
2556	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2557	  desktop machines also don't have compliant BIOSes, and this driver
2558	  may cause those machines to panic during the boot phase.
2559
2560	  Generally, if you don't have a battery in your machine, there isn't
2561	  much point in using this driver and you should say N. If you get
2562	  random kernel OOPSes or reboots that don't seem to be related to
2563	  anything, try disabling/enabling this option (or disabling/enabling
2564	  APM in your BIOS).
2565
2566	  Some other things you should try when experiencing seemingly random,
2567	  "weird" problems:
2568
2569	  1) make sure that you have enough swap space and that it is
2570	  enabled.
2571	  2) pass the "no-hlt" option to the kernel
2572	  3) switch on floating point emulation in the kernel and pass
2573	  the "no387" option to the kernel
2574	  4) pass the "floppy=nodma" option to the kernel
2575	  5) pass the "mem=4M" option to the kernel (thereby disabling
2576	  all but the first 4 MB of RAM)
2577	  6) make sure that the CPU is not over clocked.
2578	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2579	  8) disable the cache from your BIOS settings
2580	  9) install a fan for the video card or exchange video RAM
2581	  10) install a better fan for the CPU
2582	  11) exchange RAM chips
2583	  12) exchange the motherboard.
2584
2585	  To compile this driver as a module, choose M here: the
2586	  module will be called apm.
2587
2588if APM
2589
2590config APM_IGNORE_USER_SUSPEND
2591	bool "Ignore USER SUSPEND"
2592	---help---
2593	  This option will ignore USER SUSPEND requests. On machines with a
2594	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2595	  series notebooks, it is necessary to say Y because of a BIOS bug.
2596
2597config APM_DO_ENABLE
2598	bool "Enable PM at boot time"
2599	---help---
2600	  Enable APM features at boot time. From page 36 of the APM BIOS
2601	  specification: "When disabled, the APM BIOS does not automatically
2602	  power manage devices, enter the Standby State, enter the Suspend
2603	  State, or take power saving steps in response to CPU Idle calls."
2604	  This driver will make CPU Idle calls when Linux is idle (unless this
2605	  feature is turned off -- see "Do CPU IDLE calls", below). This
2606	  should always save battery power, but more complicated APM features
2607	  will be dependent on your BIOS implementation. You may need to turn
2608	  this option off if your computer hangs at boot time when using APM
2609	  support, or if it beeps continuously instead of suspending. Turn
2610	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2611	  T400CDT. This is off by default since most machines do fine without
2612	  this feature.
2613
2614config APM_CPU_IDLE
2615	depends on CPU_IDLE
2616	bool "Make CPU Idle calls when idle"
2617	---help---
2618	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2619	  On some machines, this can activate improved power savings, such as
2620	  a slowed CPU clock rate, when the machine is idle. These idle calls
2621	  are made after the idle loop has run for some length of time (e.g.,
2622	  333 mS). On some machines, this will cause a hang at boot time or
2623	  whenever the CPU becomes idle. (On machines with more than one CPU,
2624	  this option does nothing.)
2625
2626config APM_DISPLAY_BLANK
2627	bool "Enable console blanking using APM"
2628	---help---
2629	  Enable console blanking using the APM. Some laptops can use this to
2630	  turn off the LCD backlight when the screen blanker of the Linux
2631	  virtual console blanks the screen. Note that this is only used by
2632	  the virtual console screen blanker, and won't turn off the backlight
2633	  when using the X Window system. This also doesn't have anything to
2634	  do with your VESA-compliant power-saving monitor. Further, this
2635	  option doesn't work for all laptops -- it might not turn off your
2636	  backlight at all, or it might print a lot of errors to the console,
2637	  especially if you are using gpm.
2638
2639config APM_ALLOW_INTS
2640	bool "Allow interrupts during APM BIOS calls"
2641	---help---
2642	  Normally we disable external interrupts while we are making calls to
2643	  the APM BIOS as a measure to lessen the effects of a badly behaving
2644	  BIOS implementation.  The BIOS should reenable interrupts if it
2645	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2646	  many of the newer IBM Thinkpads.  If you experience hangs when you
2647	  suspend, try setting this to Y.  Otherwise, say N.
2648
2649endif # APM
2650
2651source "drivers/cpufreq/Kconfig"
2652
2653source "drivers/cpuidle/Kconfig"
2654
2655source "drivers/idle/Kconfig"
2656
2657endmenu
2658
2659
2660menu "Bus options (PCI etc.)"
2661
2662choice
2663	prompt "PCI access mode"
2664	depends on X86_32 && PCI
2665	default PCI_GOANY
2666	---help---
2667	  On PCI systems, the BIOS can be used to detect the PCI devices and
2668	  determine their configuration. However, some old PCI motherboards
2669	  have BIOS bugs and may crash if this is done. Also, some embedded
2670	  PCI-based systems don't have any BIOS at all. Linux can also try to
2671	  detect the PCI hardware directly without using the BIOS.
2672
2673	  With this option, you can specify how Linux should detect the
2674	  PCI devices. If you choose "BIOS", the BIOS will be used,
2675	  if you choose "Direct", the BIOS won't be used, and if you
2676	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2677	  If you choose "Any", the kernel will try MMCONFIG, then the
2678	  direct access method and falls back to the BIOS if that doesn't
2679	  work. If unsure, go with the default, which is "Any".
2680
2681config PCI_GOBIOS
2682	bool "BIOS"
2683
2684config PCI_GOMMCONFIG
2685	bool "MMConfig"
2686
2687config PCI_GODIRECT
2688	bool "Direct"
2689
2690config PCI_GOOLPC
2691	bool "OLPC XO-1"
2692	depends on OLPC
2693
2694config PCI_GOANY
2695	bool "Any"
2696
2697endchoice
2698
2699config PCI_BIOS
2700	def_bool y
2701	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2702
2703# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2704config PCI_DIRECT
2705	def_bool y
2706	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2707
2708config PCI_MMCONFIG
2709	bool "Support mmconfig PCI config space access" if X86_64
2710	default y
2711	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2712	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2713
2714config PCI_OLPC
2715	def_bool y
2716	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2717
2718config PCI_XEN
2719	def_bool y
2720	depends on PCI && XEN
2721	select SWIOTLB_XEN
2722
2723config MMCONF_FAM10H
2724	def_bool y
2725	depends on X86_64 && PCI_MMCONFIG && ACPI
2726
2727config PCI_CNB20LE_QUIRK
2728	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2729	depends on PCI
2730	help
2731	  Read the PCI windows out of the CNB20LE host bridge. This allows
2732	  PCI hotplug to work on systems with the CNB20LE chipset which do
2733	  not have ACPI.
2734
2735	  There's no public spec for this chipset, and this functionality
2736	  is known to be incomplete.
2737
2738	  You should say N unless you know you need this.
2739
2740config ISA_BUS
2741	bool "ISA bus support on modern systems" if EXPERT
2742	help
2743	  Expose ISA bus device drivers and options available for selection and
2744	  configuration. Enable this option if your target machine has an ISA
2745	  bus. ISA is an older system, displaced by PCI and newer bus
2746	  architectures -- if your target machine is modern, it probably does
2747	  not have an ISA bus.
2748
2749	  If unsure, say N.
2750
2751# x86_64 have no ISA slots, but can have ISA-style DMA.
2752config ISA_DMA_API
2753	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2754	default y
2755	help
2756	  Enables ISA-style DMA support for devices requiring such controllers.
2757	  If unsure, say Y.
2758
2759if X86_32
2760
2761config ISA
2762	bool "ISA support"
2763	---help---
2764	  Find out whether you have ISA slots on your motherboard.  ISA is the
2765	  name of a bus system, i.e. the way the CPU talks to the other stuff
2766	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2767	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2768	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2769
2770config SCx200
2771	tristate "NatSemi SCx200 support"
2772	---help---
2773	  This provides basic support for National Semiconductor's
2774	  (now AMD's) Geode processors.  The driver probes for the
2775	  PCI-IDs of several on-chip devices, so its a good dependency
2776	  for other scx200_* drivers.
2777
2778	  If compiled as a module, the driver is named scx200.
2779
2780config SCx200HR_TIMER
2781	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2782	depends on SCx200
2783	default y
2784	---help---
2785	  This driver provides a clocksource built upon the on-chip
2786	  27MHz high-resolution timer.  Its also a workaround for
2787	  NSC Geode SC-1100's buggy TSC, which loses time when the
2788	  processor goes idle (as is done by the scheduler).  The
2789	  other workaround is idle=poll boot option.
2790
2791config OLPC
2792	bool "One Laptop Per Child support"
2793	depends on !X86_PAE
2794	select GPIOLIB
2795	select OF
2796	select OF_PROMTREE
2797	select IRQ_DOMAIN
2798	select OLPC_EC
2799	---help---
2800	  Add support for detecting the unique features of the OLPC
2801	  XO hardware.
2802
2803config OLPC_XO1_PM
2804	bool "OLPC XO-1 Power Management"
2805	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2806	---help---
2807	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2808
2809config OLPC_XO1_RTC
2810	bool "OLPC XO-1 Real Time Clock"
2811	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2812	---help---
2813	  Add support for the XO-1 real time clock, which can be used as a
2814	  programmable wakeup source.
2815
2816config OLPC_XO1_SCI
2817	bool "OLPC XO-1 SCI extras"
2818	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2819	depends on INPUT=y
2820	select POWER_SUPPLY
2821	---help---
2822	  Add support for SCI-based features of the OLPC XO-1 laptop:
2823	   - EC-driven system wakeups
2824	   - Power button
2825	   - Ebook switch
2826	   - Lid switch
2827	   - AC adapter status updates
2828	   - Battery status updates
2829
2830config OLPC_XO15_SCI
2831	bool "OLPC XO-1.5 SCI extras"
2832	depends on OLPC && ACPI
2833	select POWER_SUPPLY
2834	---help---
2835	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2836	   - EC-driven system wakeups
2837	   - AC adapter status updates
2838	   - Battery status updates
2839
2840config ALIX
2841	bool "PCEngines ALIX System Support (LED setup)"
2842	select GPIOLIB
2843	---help---
2844	  This option enables system support for the PCEngines ALIX.
2845	  At present this just sets up LEDs for GPIO control on
2846	  ALIX2/3/6 boards.  However, other system specific setup should
2847	  get added here.
2848
2849	  Note: You must still enable the drivers for GPIO and LED support
2850	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2851
2852	  Note: You have to set alix.force=1 for boards with Award BIOS.
2853
2854config NET5501
2855	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2856	select GPIOLIB
2857	---help---
2858	  This option enables system support for the Soekris Engineering net5501.
2859
2860config GEOS
2861	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2862	select GPIOLIB
2863	depends on DMI
2864	---help---
2865	  This option enables system support for the Traverse Technologies GEOS.
2866
2867config TS5500
2868	bool "Technologic Systems TS-5500 platform support"
2869	depends on MELAN
2870	select CHECK_SIGNATURE
2871	select NEW_LEDS
2872	select LEDS_CLASS
2873	---help---
2874	  This option enables system support for the Technologic Systems TS-5500.
2875
2876endif # X86_32
2877
2878config AMD_NB
2879	def_bool y
2880	depends on CPU_SUP_AMD && PCI
2881
2882config X86_SYSFB
2883	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2884	help
2885	  Firmwares often provide initial graphics framebuffers so the BIOS,
2886	  bootloader or kernel can show basic video-output during boot for
2887	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2888	  Extensions and EFI-framebuffers for this, which are mostly limited
2889	  to x86.
2890	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2891	  framebuffers so the new generic system-framebuffer drivers can be
2892	  used on x86. If the framebuffer is not compatible with the generic
2893	  modes, it is advertised as fallback platform framebuffer so legacy
2894	  drivers like efifb, vesafb and uvesafb can pick it up.
2895	  If this option is not selected, all system framebuffers are always
2896	  marked as fallback platform framebuffers as usual.
2897
2898	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2899	  not be able to pick up generic system framebuffers if this option
2900	  is selected. You are highly encouraged to enable simplefb as
2901	  replacement if you select this option. simplefb can correctly deal
2902	  with generic system framebuffers. But you should still keep vesafb
2903	  and others enabled as fallback if a system framebuffer is
2904	  incompatible with simplefb.
2905
2906	  If unsure, say Y.
2907
2908endmenu
2909
2910
2911menu "Binary Emulations"
2912
2913config IA32_EMULATION
2914	bool "IA32 Emulation"
2915	depends on X86_64
2916	select ARCH_WANT_OLD_COMPAT_IPC
2917	select BINFMT_ELF
2918	select COMPAT_BINFMT_ELF
2919	select COMPAT_OLD_SIGACTION
2920	---help---
2921	  Include code to run legacy 32-bit programs under a
2922	  64-bit kernel. You should likely turn this on, unless you're
2923	  100% sure that you don't have any 32-bit programs left.
2924
2925config IA32_AOUT
2926	tristate "IA32 a.out support"
2927	depends on IA32_EMULATION
2928	depends on BROKEN
2929	---help---
2930	  Support old a.out binaries in the 32bit emulation.
2931
2932config X86_X32
2933	bool "x32 ABI for 64-bit mode"
2934	depends on X86_64
2935	---help---
2936	  Include code to run binaries for the x32 native 32-bit ABI
2937	  for 64-bit processors.  An x32 process gets access to the
2938	  full 64-bit register file and wide data path while leaving
2939	  pointers at 32 bits for smaller memory footprint.
2940
2941	  You will need a recent binutils (2.22 or later) with
2942	  elf32_x86_64 support enabled to compile a kernel with this
2943	  option set.
2944
2945config COMPAT_32
2946	def_bool y
2947	depends on IA32_EMULATION || X86_32
2948	select HAVE_UID16
2949	select OLD_SIGSUSPEND3
2950
2951config COMPAT
2952	def_bool y
2953	depends on IA32_EMULATION || X86_X32
2954
2955if COMPAT
2956config COMPAT_FOR_U64_ALIGNMENT
2957	def_bool y
2958
2959config SYSVIPC_COMPAT
2960	def_bool y
2961	depends on SYSVIPC
2962endif
2963
2964endmenu
2965
2966
2967config HAVE_ATOMIC_IOMAP
2968	def_bool y
2969	depends on X86_32
2970
2971config X86_DEV_DMA_OPS
2972	bool
2973
2974source "drivers/firmware/Kconfig"
2975
2976source "arch/x86/kvm/Kconfig"
2977