xref: /linux/arch/x86/Kconfig (revision 009bd55dfcc857d8b00a5bbb17a8db060317af6f)
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 GENERIC_VDSO_32
18	select HAVE_DEBUG_STACKOVERFLOW
19	select KMAP_LOCAL
20	select MODULES_USE_ELF_REL
21	select OLD_SIGACTION
22
23config X86_64
24	def_bool y
25	depends on 64BIT
26	# Options that are inherently 64-bit kernel only:
27	select ARCH_HAS_GIGANTIC_PAGE
28	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
29	select ARCH_USE_CMPXCHG_LOCKREF
30	select HAVE_ARCH_SOFT_DIRTY
31	select MODULES_USE_ELF_RELA
32	select NEED_DMA_MAP_STATE
33	select SWIOTLB
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_INIT
61	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
62	select ARCH_HAS_DEBUG_VIRTUAL
63	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
64	select ARCH_HAS_DEVMEM_IS_ALLOWED
65	select ARCH_HAS_EARLY_DEBUG		if KGDB
66	select ARCH_HAS_ELF_RANDOMIZE
67	select ARCH_HAS_FAST_MULTIPLIER
68	select ARCH_HAS_FILTER_PGPROT
69	select ARCH_HAS_FORTIFY_SOURCE
70	select ARCH_HAS_GCOV_PROFILE_ALL
71	select ARCH_HAS_KCOV			if X86_64 && STACK_VALIDATION
72	select ARCH_HAS_MEM_ENCRYPT
73	select ARCH_HAS_MEMBARRIER_SYNC_CORE
74	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
75	select ARCH_HAS_PMEM_API		if X86_64
76	select ARCH_HAS_PTE_DEVMAP		if X86_64
77	select ARCH_HAS_PTE_SPECIAL
78	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
79	select ARCH_HAS_COPY_MC			if X86_64
80	select ARCH_HAS_SET_MEMORY
81	select ARCH_HAS_SET_DIRECT_MAP
82	select ARCH_HAS_STRICT_KERNEL_RWX
83	select ARCH_HAS_STRICT_MODULE_RWX
84	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
85	select ARCH_HAS_SYSCALL_WRAPPER
86	select ARCH_HAS_UBSAN_SANITIZE_ALL
87	select ARCH_HAS_DEBUG_WX
88	select ARCH_HAVE_NMI_SAFE_CMPXCHG
89	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
90	select ARCH_MIGHT_HAVE_PC_PARPORT
91	select ARCH_MIGHT_HAVE_PC_SERIO
92	select ARCH_STACKWALK
93	select ARCH_SUPPORTS_ACPI
94	select ARCH_SUPPORTS_ATOMIC_RMW
95	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
96	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
97	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
98	select ARCH_USE_BUILTIN_BSWAP
99	select ARCH_USE_QUEUED_RWLOCKS
100	select ARCH_USE_QUEUED_SPINLOCKS
101	select ARCH_USE_SYM_ANNOTATIONS
102	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
103	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
104	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
105	select ARCH_WANT_HUGE_PMD_SHARE
106	select ARCH_WANT_LD_ORPHAN_WARN
107	select ARCH_WANTS_THP_SWAP		if X86_64
108	select BUILDTIME_TABLE_SORT
109	select CLKEVT_I8253
110	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
111	select CLOCKSOURCE_WATCHDOG
112	select DCACHE_WORD_ACCESS
113	select EDAC_ATOMIC_SCRUB
114	select EDAC_SUPPORT
115	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
116	select GENERIC_CLOCKEVENTS_MIN_ADJUST
117	select GENERIC_CMOS_UPDATE
118	select GENERIC_CPU_AUTOPROBE
119	select GENERIC_CPU_VULNERABILITIES
120	select GENERIC_EARLY_IOREMAP
121	select GENERIC_ENTRY
122	select GENERIC_FIND_FIRST_BIT
123	select GENERIC_IOMAP
124	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
125	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
126	select GENERIC_IRQ_MIGRATION		if SMP
127	select GENERIC_IRQ_PROBE
128	select GENERIC_IRQ_RESERVATION_MODE
129	select GENERIC_IRQ_SHOW
130	select GENERIC_PENDING_IRQ		if SMP
131	select GENERIC_PTDUMP
132	select GENERIC_SMP_IDLE_THREAD
133	select GENERIC_STRNCPY_FROM_USER
134	select GENERIC_STRNLEN_USER
135	select GENERIC_TIME_VSYSCALL
136	select GENERIC_GETTIMEOFDAY
137	select GENERIC_VDSO_TIME_NS
138	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
139	select HARDIRQS_SW_RESEND
140	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
141	select HAVE_ACPI_APEI			if ACPI
142	select HAVE_ACPI_APEI_NMI		if ACPI
143	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
144	select HAVE_ARCH_AUDITSYSCALL
145	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
146	select HAVE_ARCH_JUMP_LABEL
147	select HAVE_ARCH_JUMP_LABEL_RELATIVE
148	select HAVE_ARCH_KASAN			if X86_64
149	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
150	select HAVE_ARCH_KGDB
151	select HAVE_ARCH_MMAP_RND_BITS		if MMU
152	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
153	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
154	select HAVE_ARCH_PREL32_RELOCATIONS
155	select HAVE_ARCH_SECCOMP_FILTER
156	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
157	select HAVE_ARCH_STACKLEAK
158	select HAVE_ARCH_TRACEHOOK
159	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
160	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
161	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
162	select HAVE_ARCH_VMAP_STACK		if X86_64
163	select HAVE_ARCH_WITHIN_STACK_FRAMES
164	select HAVE_ASM_MODVERSIONS
165	select HAVE_CMPXCHG_DOUBLE
166	select HAVE_CMPXCHG_LOCAL
167	select HAVE_CONTEXT_TRACKING		if X86_64
168	select HAVE_CONTEXT_TRACKING_OFFSTACK	if HAVE_CONTEXT_TRACKING
169	select HAVE_C_RECORDMCOUNT
170	select HAVE_DEBUG_KMEMLEAK
171	select HAVE_DMA_CONTIGUOUS
172	select HAVE_DYNAMIC_FTRACE
173	select HAVE_DYNAMIC_FTRACE_WITH_REGS
174	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
175	select HAVE_EBPF_JIT
176	select HAVE_EFFICIENT_UNALIGNED_ACCESS
177	select HAVE_EISA
178	select HAVE_EXIT_THREAD
179	select HAVE_FAST_GUP
180	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
181	select HAVE_FTRACE_MCOUNT_RECORD
182	select HAVE_FUNCTION_GRAPH_TRACER
183	select HAVE_FUNCTION_TRACER
184	select HAVE_GCC_PLUGINS
185	select HAVE_HW_BREAKPOINT
186	select HAVE_IDE
187	select HAVE_IOREMAP_PROT
188	select HAVE_IRQ_TIME_ACCOUNTING
189	select HAVE_KERNEL_BZIP2
190	select HAVE_KERNEL_GZIP
191	select HAVE_KERNEL_LZ4
192	select HAVE_KERNEL_LZMA
193	select HAVE_KERNEL_LZO
194	select HAVE_KERNEL_XZ
195	select HAVE_KERNEL_ZSTD
196	select HAVE_KPROBES
197	select HAVE_KPROBES_ON_FTRACE
198	select HAVE_FUNCTION_ERROR_INJECTION
199	select HAVE_KRETPROBES
200	select HAVE_KVM
201	select HAVE_LIVEPATCH			if X86_64
202	select HAVE_MIXED_BREAKPOINTS_REGS
203	select HAVE_MOD_ARCH_SPECIFIC
204	select HAVE_MOVE_PMD
205	select HAVE_MOVE_PUD
206	select HAVE_NMI
207	select HAVE_OPROFILE
208	select HAVE_OPTPROBES
209	select HAVE_PCSPKR_PLATFORM
210	select HAVE_PERF_EVENTS
211	select HAVE_PERF_EVENTS_NMI
212	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
213	select HAVE_PCI
214	select HAVE_PERF_REGS
215	select HAVE_PERF_USER_STACK_DUMP
216	select MMU_GATHER_RCU_TABLE_FREE		if PARAVIRT
217	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
218	select HAVE_REGS_AND_STACK_ACCESS_API
219	select HAVE_RELIABLE_STACKTRACE		if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
220	select HAVE_FUNCTION_ARG_ACCESS_API
221	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
222	select HAVE_STACK_VALIDATION		if X86_64
223	select HAVE_STATIC_CALL
224	select HAVE_STATIC_CALL_INLINE		if HAVE_STACK_VALIDATION
225	select HAVE_RSEQ
226	select HAVE_SYSCALL_TRACEPOINTS
227	select HAVE_UNSTABLE_SCHED_CLOCK
228	select HAVE_USER_RETURN_NOTIFIER
229	select HAVE_GENERIC_VDSO
230	select HOTPLUG_SMT			if SMP
231	select IRQ_FORCED_THREADING
232	select NEED_SG_DMA_LENGTH
233	select PCI_DOMAINS			if PCI
234	select PCI_LOCKLESS_CONFIG		if PCI
235	select PERF_EVENTS
236	select RTC_LIB
237	select RTC_MC146818_LIB
238	select SPARSE_IRQ
239	select SRCU
240	select STACK_VALIDATION			if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
241	select SYSCTL_EXCEPTION_TRACE
242	select THREAD_INFO_IN_TASK
243	select USER_STACKTRACE_SUPPORT
244	select VIRT_TO_BUS
245	select HAVE_ARCH_KCSAN			if X86_64
246	select X86_FEATURE_NAMES		if PROC_FS
247	select PROC_PID_ARCH_STATUS		if PROC_FS
248	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
249
250config INSTRUCTION_DECODER
251	def_bool y
252	depends on KPROBES || PERF_EVENTS || UPROBES
253
254config OUTPUT_FORMAT
255	string
256	default "elf32-i386" if X86_32
257	default "elf64-x86-64" if X86_64
258
259config LOCKDEP_SUPPORT
260	def_bool y
261
262config STACKTRACE_SUPPORT
263	def_bool y
264
265config MMU
266	def_bool y
267
268config ARCH_MMAP_RND_BITS_MIN
269	default 28 if 64BIT
270	default 8
271
272config ARCH_MMAP_RND_BITS_MAX
273	default 32 if 64BIT
274	default 16
275
276config ARCH_MMAP_RND_COMPAT_BITS_MIN
277	default 8
278
279config ARCH_MMAP_RND_COMPAT_BITS_MAX
280	default 16
281
282config SBUS
283	bool
284
285config GENERIC_ISA_DMA
286	def_bool y
287	depends on ISA_DMA_API
288
289config GENERIC_BUG
290	def_bool y
291	depends on BUG
292	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
293
294config GENERIC_BUG_RELATIVE_POINTERS
295	bool
296
297config ARCH_MAY_HAVE_PC_FDC
298	def_bool y
299	depends on ISA_DMA_API
300
301config GENERIC_CALIBRATE_DELAY
302	def_bool y
303
304config ARCH_HAS_CPU_RELAX
305	def_bool y
306
307config ARCH_HAS_CACHE_LINE_SIZE
308	def_bool y
309
310config ARCH_HAS_FILTER_PGPROT
311	def_bool y
312
313config HAVE_SETUP_PER_CPU_AREA
314	def_bool y
315
316config NEED_PER_CPU_EMBED_FIRST_CHUNK
317	def_bool y
318
319config NEED_PER_CPU_PAGE_FIRST_CHUNK
320	def_bool y
321
322config ARCH_HIBERNATION_POSSIBLE
323	def_bool y
324
325config ARCH_SUSPEND_POSSIBLE
326	def_bool y
327
328config ARCH_WANT_GENERAL_HUGETLB
329	def_bool y
330
331config ZONE_DMA32
332	def_bool y if X86_64
333
334config AUDIT_ARCH
335	def_bool y if X86_64
336
337config KASAN_SHADOW_OFFSET
338	hex
339	depends on KASAN
340	default 0xdffffc0000000000
341
342config HAVE_INTEL_TXT
343	def_bool y
344	depends on INTEL_IOMMU && ACPI
345
346config X86_32_SMP
347	def_bool y
348	depends on X86_32 && SMP
349
350config X86_64_SMP
351	def_bool y
352	depends on X86_64 && SMP
353
354config X86_32_LAZY_GS
355	def_bool y
356	depends on X86_32 && !STACKPROTECTOR
357
358config ARCH_SUPPORTS_UPROBES
359	def_bool y
360
361config FIX_EARLYCON_MEM
362	def_bool y
363
364config DYNAMIC_PHYSICAL_MASK
365	bool
366
367config PGTABLE_LEVELS
368	int
369	default 5 if X86_5LEVEL
370	default 4 if X86_64
371	default 3 if X86_PAE
372	default 2
373
374config CC_HAS_SANE_STACKPROTECTOR
375	bool
376	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
377	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
378	help
379	   We have to make sure stack protector is unconditionally disabled if
380	   the compiler produces broken code.
381
382menu "Processor type and features"
383
384config ZONE_DMA
385	bool "DMA memory allocation support" if EXPERT
386	default y
387	help
388	  DMA memory allocation support allows devices with less than 32-bit
389	  addressing to allocate within the first 16MB of address space.
390	  Disable if no such devices will be used.
391
392	  If unsure, say Y.
393
394config SMP
395	bool "Symmetric multi-processing support"
396	help
397	  This enables support for systems with more than one CPU. If you have
398	  a system with only one CPU, say N. If you have a system with more
399	  than one CPU, say Y.
400
401	  If you say N here, the kernel will run on uni- and multiprocessor
402	  machines, but will use only one CPU of a multiprocessor machine. If
403	  you say Y here, the kernel will run on many, but not all,
404	  uniprocessor machines. On a uniprocessor machine, the kernel
405	  will run faster if you say N here.
406
407	  Note that if you say Y here and choose architecture "586" or
408	  "Pentium" under "Processor family", the kernel will not work on 486
409	  architectures. Similarly, multiprocessor kernels for the "PPro"
410	  architecture may not work on all Pentium based boards.
411
412	  People using multiprocessor machines who say Y here should also say
413	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
414	  Management" code will be disabled if you say Y here.
415
416	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
417	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
418	  <http://www.tldp.org/docs.html#howto>.
419
420	  If you don't know what to do here, say N.
421
422config X86_FEATURE_NAMES
423	bool "Processor feature human-readable names" if EMBEDDED
424	default y
425	help
426	  This option compiles in a table of x86 feature bits and corresponding
427	  names.  This is required to support /proc/cpuinfo and a few kernel
428	  messages.  You can disable this to save space, at the expense of
429	  making those few kernel messages show numeric feature bits instead.
430
431	  If in doubt, say Y.
432
433config X86_X2APIC
434	bool "Support x2apic"
435	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
436	help
437	  This enables x2apic support on CPUs that have this feature.
438
439	  This allows 32-bit apic IDs (so it can support very large systems),
440	  and accesses the local apic via MSRs not via mmio.
441
442	  If you don't know what to do here, say N.
443
444config X86_MPPARSE
445	bool "Enable MPS table" if ACPI || SFI
446	default y
447	depends on X86_LOCAL_APIC
448	help
449	  For old smp systems that do not have proper acpi support. Newer systems
450	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
451
452config GOLDFISH
453	def_bool y
454	depends on X86_GOLDFISH
455
456config RETPOLINE
457	bool "Avoid speculative indirect branches in kernel"
458	default y
459	help
460	  Compile kernel with the retpoline compiler options to guard against
461	  kernel-to-user data leaks by avoiding speculative indirect
462	  branches. Requires a compiler with -mindirect-branch=thunk-extern
463	  support for full protection. The kernel may run slower.
464
465config X86_CPU_RESCTRL
466	bool "x86 CPU resource control support"
467	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
468	select KERNFS
469	select PROC_CPU_RESCTRL		if PROC_FS
470	help
471	  Enable x86 CPU resource control support.
472
473	  Provide support for the allocation and monitoring of system resources
474	  usage by the CPU.
475
476	  Intel calls this Intel Resource Director Technology
477	  (Intel(R) RDT). More information about RDT can be found in the
478	  Intel x86 Architecture Software Developer Manual.
479
480	  AMD calls this AMD Platform Quality of Service (AMD QoS).
481	  More information about AMD QoS can be found in the AMD64 Technology
482	  Platform Quality of Service Extensions manual.
483
484	  Say N if unsure.
485
486if X86_32
487config X86_BIGSMP
488	bool "Support for big SMP systems with more than 8 CPUs"
489	depends on SMP
490	help
491	  This option is needed for the systems that have more than 8 CPUs.
492
493config X86_EXTENDED_PLATFORM
494	bool "Support for extended (non-PC) x86 platforms"
495	default y
496	help
497	  If you disable this option then the kernel will only support
498	  standard PC platforms. (which covers the vast majority of
499	  systems out there.)
500
501	  If you enable this option then you'll be able to select support
502	  for the following (non-PC) 32 bit x86 platforms:
503		Goldfish (Android emulator)
504		AMD Elan
505		RDC R-321x SoC
506		SGI 320/540 (Visual Workstation)
507		STA2X11-based (e.g. Northville)
508		Moorestown MID devices
509
510	  If you have one of these systems, or if you want to build a
511	  generic distribution kernel, say Y here - otherwise say N.
512endif
513
514if X86_64
515config X86_EXTENDED_PLATFORM
516	bool "Support for extended (non-PC) x86 platforms"
517	default y
518	help
519	  If you disable this option then the kernel will only support
520	  standard PC platforms. (which covers the vast majority of
521	  systems out there.)
522
523	  If you enable this option then you'll be able to select support
524	  for the following (non-PC) 64 bit x86 platforms:
525		Numascale NumaChip
526		ScaleMP vSMP
527		SGI Ultraviolet
528
529	  If you have one of these systems, or if you want to build a
530	  generic distribution kernel, say Y here - otherwise say N.
531endif
532# This is an alphabetically sorted list of 64 bit extended platforms
533# Please maintain the alphabetic order if and when there are additions
534config X86_NUMACHIP
535	bool "Numascale NumaChip"
536	depends on X86_64
537	depends on X86_EXTENDED_PLATFORM
538	depends on NUMA
539	depends on SMP
540	depends on X86_X2APIC
541	depends on PCI_MMCONFIG
542	help
543	  Adds support for Numascale NumaChip large-SMP systems. Needed to
544	  enable more than ~168 cores.
545	  If you don't have one of these, you should say N here.
546
547config X86_VSMP
548	bool "ScaleMP vSMP"
549	select HYPERVISOR_GUEST
550	select PARAVIRT
551	depends on X86_64 && PCI
552	depends on X86_EXTENDED_PLATFORM
553	depends on SMP
554	help
555	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
556	  supposed to run on these EM64T-based machines.  Only choose this option
557	  if you have one of these machines.
558
559config X86_UV
560	bool "SGI Ultraviolet"
561	depends on X86_64
562	depends on X86_EXTENDED_PLATFORM
563	depends on NUMA
564	depends on EFI
565	depends on X86_X2APIC
566	depends on PCI
567	help
568	  This option is needed in order to support SGI Ultraviolet systems.
569	  If you don't have one of these, you should say N here.
570
571# Following is an alphabetically sorted list of 32 bit extended platforms
572# Please maintain the alphabetic order if and when there are additions
573
574config X86_GOLDFISH
575	bool "Goldfish (Virtual Platform)"
576	depends on X86_EXTENDED_PLATFORM
577	help
578	 Enable support for the Goldfish virtual platform used primarily
579	 for Android development. Unless you are building for the Android
580	 Goldfish emulator say N here.
581
582config X86_INTEL_CE
583	bool "CE4100 TV platform"
584	depends on PCI
585	depends on PCI_GODIRECT
586	depends on X86_IO_APIC
587	depends on X86_32
588	depends on X86_EXTENDED_PLATFORM
589	select X86_REBOOTFIXUPS
590	select OF
591	select OF_EARLY_FLATTREE
592	help
593	  Select for the Intel CE media processor (CE4100) SOC.
594	  This option compiles in support for the CE4100 SOC for settop
595	  boxes and media devices.
596
597config X86_INTEL_MID
598	bool "Intel MID platform support"
599	depends on X86_EXTENDED_PLATFORM
600	depends on X86_PLATFORM_DEVICES
601	depends on PCI
602	depends on X86_64 || (PCI_GOANY && X86_32)
603	depends on X86_IO_APIC
604	select SFI
605	select I2C
606	select DW_APB_TIMER
607	select APB_TIMER
608	select INTEL_SCU_PCI
609	select MFD_INTEL_MSIC
610	help
611	  Select to build a kernel capable of supporting Intel MID (Mobile
612	  Internet Device) platform systems which do not have the PCI legacy
613	  interfaces. If you are building for a PC class system say N here.
614
615	  Intel MID platforms are based on an Intel processor and chipset which
616	  consume less power than most of the x86 derivatives.
617
618config X86_INTEL_QUARK
619	bool "Intel Quark platform support"
620	depends on X86_32
621	depends on X86_EXTENDED_PLATFORM
622	depends on X86_PLATFORM_DEVICES
623	depends on X86_TSC
624	depends on PCI
625	depends on PCI_GOANY
626	depends on X86_IO_APIC
627	select IOSF_MBI
628	select INTEL_IMR
629	select COMMON_CLK
630	help
631	  Select to include support for Quark X1000 SoC.
632	  Say Y here if you have a Quark based system such as the Arduino
633	  compatible Intel Galileo.
634
635config X86_INTEL_LPSS
636	bool "Intel Low Power Subsystem Support"
637	depends on X86 && ACPI && PCI
638	select COMMON_CLK
639	select PINCTRL
640	select IOSF_MBI
641	help
642	  Select to build support for Intel Low Power Subsystem such as
643	  found on Intel Lynxpoint PCH. Selecting this option enables
644	  things like clock tree (common clock framework) and pincontrol
645	  which are needed by the LPSS peripheral drivers.
646
647config X86_AMD_PLATFORM_DEVICE
648	bool "AMD ACPI2Platform devices support"
649	depends on ACPI
650	select COMMON_CLK
651	select PINCTRL
652	help
653	  Select to interpret AMD specific ACPI device to platform device
654	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
655	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
656	  implemented under PINCTRL subsystem.
657
658config IOSF_MBI
659	tristate "Intel SoC IOSF Sideband support for SoC platforms"
660	depends on PCI
661	help
662	  This option enables sideband register access support for Intel SoC
663	  platforms. On these platforms the IOSF sideband is used in lieu of
664	  MSR's for some register accesses, mostly but not limited to thermal
665	  and power. Drivers may query the availability of this device to
666	  determine if they need the sideband in order to work on these
667	  platforms. The sideband is available on the following SoC products.
668	  This list is not meant to be exclusive.
669	   - BayTrail
670	   - Braswell
671	   - Quark
672
673	  You should say Y if you are running a kernel on one of these SoC's.
674
675config IOSF_MBI_DEBUG
676	bool "Enable IOSF sideband access through debugfs"
677	depends on IOSF_MBI && DEBUG_FS
678	help
679	  Select this option to expose the IOSF sideband access registers (MCR,
680	  MDR, MCRX) through debugfs to write and read register information from
681	  different units on the SoC. This is most useful for obtaining device
682	  state information for debug and analysis. As this is a general access
683	  mechanism, users of this option would have specific knowledge of the
684	  device they want to access.
685
686	  If you don't require the option or are in doubt, say N.
687
688config X86_RDC321X
689	bool "RDC R-321x SoC"
690	depends on X86_32
691	depends on X86_EXTENDED_PLATFORM
692	select M486
693	select X86_REBOOTFIXUPS
694	help
695	  This option is needed for RDC R-321x system-on-chip, also known
696	  as R-8610-(G).
697	  If you don't have one of these chips, you should say N here.
698
699config X86_32_NON_STANDARD
700	bool "Support non-standard 32-bit SMP architectures"
701	depends on X86_32 && SMP
702	depends on X86_EXTENDED_PLATFORM
703	help
704	  This option compiles in the bigsmp and STA2X11 default
705	  subarchitectures.  It is intended for a generic binary
706	  kernel. If you select them all, kernel will probe it one by
707	  one and will fallback to default.
708
709# Alphabetically sorted list of Non standard 32 bit platforms
710
711config X86_SUPPORTS_MEMORY_FAILURE
712	def_bool y
713	# MCE code calls memory_failure():
714	depends on X86_MCE
715	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
716	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
717	depends on X86_64 || !SPARSEMEM
718	select ARCH_SUPPORTS_MEMORY_FAILURE
719
720config STA2X11
721	bool "STA2X11 Companion Chip Support"
722	depends on X86_32_NON_STANDARD && PCI
723	select SWIOTLB
724	select MFD_STA2X11
725	select GPIOLIB
726	help
727	  This adds support for boards based on the STA2X11 IO-Hub,
728	  a.k.a. "ConneXt". The chip is used in place of the standard
729	  PC chipset, so all "standard" peripherals are missing. If this
730	  option is selected the kernel will still be able to boot on
731	  standard PC machines.
732
733config X86_32_IRIS
734	tristate "Eurobraille/Iris poweroff module"
735	depends on X86_32
736	help
737	  The Iris machines from EuroBraille do not have APM or ACPI support
738	  to shut themselves down properly.  A special I/O sequence is
739	  needed to do so, which is what this module does at
740	  kernel shutdown.
741
742	  This is only for Iris machines from EuroBraille.
743
744	  If unused, say N.
745
746config SCHED_OMIT_FRAME_POINTER
747	def_bool y
748	prompt "Single-depth WCHAN output"
749	depends on X86
750	help
751	  Calculate simpler /proc/<PID>/wchan values. If this option
752	  is disabled then wchan values will recurse back to the
753	  caller function. This provides more accurate wchan values,
754	  at the expense of slightly more scheduling overhead.
755
756	  If in doubt, say "Y".
757
758menuconfig HYPERVISOR_GUEST
759	bool "Linux guest support"
760	help
761	  Say Y here to enable options for running Linux under various hyper-
762	  visors. This option enables basic hypervisor detection and platform
763	  setup.
764
765	  If you say N, all options in this submenu will be skipped and
766	  disabled, and Linux guest support won't be built in.
767
768if HYPERVISOR_GUEST
769
770config PARAVIRT
771	bool "Enable paravirtualization code"
772	help
773	  This changes the kernel so it can modify itself when it is run
774	  under a hypervisor, potentially improving performance significantly
775	  over full virtualization.  However, when run without a hypervisor
776	  the kernel is theoretically slower and slightly larger.
777
778config PARAVIRT_XXL
779	bool
780
781config PARAVIRT_DEBUG
782	bool "paravirt-ops debugging"
783	depends on PARAVIRT && DEBUG_KERNEL
784	help
785	  Enable to debug paravirt_ops internals.  Specifically, BUG if
786	  a paravirt_op is missing when it is called.
787
788config PARAVIRT_SPINLOCKS
789	bool "Paravirtualization layer for spinlocks"
790	depends on PARAVIRT && SMP
791	help
792	  Paravirtualized spinlocks allow a pvops backend to replace the
793	  spinlock implementation with something virtualization-friendly
794	  (for example, block the virtual CPU rather than spinning).
795
796	  It has a minimal impact on native kernels and gives a nice performance
797	  benefit on paravirtualized KVM / Xen kernels.
798
799	  If you are unsure how to answer this question, answer Y.
800
801config X86_HV_CALLBACK_VECTOR
802	def_bool n
803
804source "arch/x86/xen/Kconfig"
805
806config KVM_GUEST
807	bool "KVM Guest support (including kvmclock)"
808	depends on PARAVIRT
809	select PARAVIRT_CLOCK
810	select ARCH_CPUIDLE_HALTPOLL
811	select X86_HV_CALLBACK_VECTOR
812	default y
813	help
814	  This option enables various optimizations for running under the KVM
815	  hypervisor. It includes a paravirtualized clock, so that instead
816	  of relying on a PIT (or probably other) emulation by the
817	  underlying device model, the host provides the guest with
818	  timing infrastructure such as time of day, and system time
819
820config ARCH_CPUIDLE_HALTPOLL
821	def_bool n
822	prompt "Disable host haltpoll when loading haltpoll driver"
823	help
824	  If virtualized under KVM, disable host haltpoll.
825
826config PVH
827	bool "Support for running PVH guests"
828	help
829	  This option enables the PVH entry point for guest virtual machines
830	  as specified in the x86/HVM direct boot ABI.
831
832config PARAVIRT_TIME_ACCOUNTING
833	bool "Paravirtual steal time accounting"
834	depends on PARAVIRT
835	help
836	  Select this option to enable fine granularity task steal time
837	  accounting. Time spent executing other tasks in parallel with
838	  the current vCPU is discounted from the vCPU power. To account for
839	  that, there can be a small performance impact.
840
841	  If in doubt, say N here.
842
843config PARAVIRT_CLOCK
844	bool
845
846config JAILHOUSE_GUEST
847	bool "Jailhouse non-root cell support"
848	depends on X86_64 && PCI
849	select X86_PM_TIMER
850	help
851	  This option allows to run Linux as guest in a Jailhouse non-root
852	  cell. You can leave this option disabled if you only want to start
853	  Jailhouse and run Linux afterwards in the root cell.
854
855config ACRN_GUEST
856	bool "ACRN Guest support"
857	depends on X86_64
858	select X86_HV_CALLBACK_VECTOR
859	help
860	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
861	  a flexible, lightweight reference open-source hypervisor, built with
862	  real-time and safety-criticality in mind. It is built for embedded
863	  IOT with small footprint and real-time features. More details can be
864	  found in https://projectacrn.org/.
865
866endif #HYPERVISOR_GUEST
867
868source "arch/x86/Kconfig.cpu"
869
870config HPET_TIMER
871	def_bool X86_64
872	prompt "HPET Timer Support" if X86_32
873	help
874	  Use the IA-PC HPET (High Precision Event Timer) to manage
875	  time in preference to the PIT and RTC, if a HPET is
876	  present.
877	  HPET is the next generation timer replacing legacy 8254s.
878	  The HPET provides a stable time base on SMP
879	  systems, unlike the TSC, but it is more expensive to access,
880	  as it is off-chip.  The interface used is documented
881	  in the HPET spec, revision 1.
882
883	  You can safely choose Y here.  However, HPET will only be
884	  activated if the platform and the BIOS support this feature.
885	  Otherwise the 8254 will be used for timing services.
886
887	  Choose N to continue using the legacy 8254 timer.
888
889config HPET_EMULATE_RTC
890	def_bool y
891	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
892
893config APB_TIMER
894	def_bool y if X86_INTEL_MID
895	prompt "Intel MID APB Timer Support" if X86_INTEL_MID
896	select DW_APB_TIMER
897	depends on X86_INTEL_MID && SFI
898	help
899	 APB timer is the replacement for 8254, HPET on X86 MID platforms.
900	 The APBT provides a stable time base on SMP
901	 systems, unlike the TSC, but it is more expensive to access,
902	 as it is off-chip. APB timers are always running regardless of CPU
903	 C states, they are used as per CPU clockevent device when possible.
904
905# Mark as expert because too many people got it wrong.
906# The code disables itself when not needed.
907config DMI
908	default y
909	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
910	bool "Enable DMI scanning" if EXPERT
911	help
912	  Enabled scanning of DMI to identify machine quirks. Say Y
913	  here unless you have verified that your setup is not
914	  affected by entries in the DMI blacklist. Required by PNP
915	  BIOS code.
916
917config GART_IOMMU
918	bool "Old AMD GART IOMMU support"
919	select DMA_OPS
920	select IOMMU_HELPER
921	select SWIOTLB
922	depends on X86_64 && PCI && AMD_NB
923	help
924	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
925	  GART based hardware IOMMUs.
926
927	  The GART supports full DMA access for devices with 32-bit access
928	  limitations, on systems with more than 3 GB. This is usually needed
929	  for USB, sound, many IDE/SATA chipsets and some other devices.
930
931	  Newer systems typically have a modern AMD IOMMU, supported via
932	  the CONFIG_AMD_IOMMU=y config option.
933
934	  In normal configurations this driver is only active when needed:
935	  there's more than 3 GB of memory and the system contains a
936	  32-bit limited device.
937
938	  If unsure, say Y.
939
940config MAXSMP
941	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
942	depends on X86_64 && SMP && DEBUG_KERNEL
943	select CPUMASK_OFFSTACK
944	help
945	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
946	  If unsure, say N.
947
948#
949# The maximum number of CPUs supported:
950#
951# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
952# and which can be configured interactively in the
953# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
954#
955# The ranges are different on 32-bit and 64-bit kernels, depending on
956# hardware capabilities and scalability features of the kernel.
957#
958# ( If MAXSMP is enabled we just use the highest possible value and disable
959#   interactive configuration. )
960#
961
962config NR_CPUS_RANGE_BEGIN
963	int
964	default NR_CPUS_RANGE_END if MAXSMP
965	default    1 if !SMP
966	default    2
967
968config NR_CPUS_RANGE_END
969	int
970	depends on X86_32
971	default   64 if  SMP &&  X86_BIGSMP
972	default    8 if  SMP && !X86_BIGSMP
973	default    1 if !SMP
974
975config NR_CPUS_RANGE_END
976	int
977	depends on X86_64
978	default 8192 if  SMP && CPUMASK_OFFSTACK
979	default  512 if  SMP && !CPUMASK_OFFSTACK
980	default    1 if !SMP
981
982config NR_CPUS_DEFAULT
983	int
984	depends on X86_32
985	default   32 if  X86_BIGSMP
986	default    8 if  SMP
987	default    1 if !SMP
988
989config NR_CPUS_DEFAULT
990	int
991	depends on X86_64
992	default 8192 if  MAXSMP
993	default   64 if  SMP
994	default    1 if !SMP
995
996config NR_CPUS
997	int "Maximum number of CPUs" if SMP && !MAXSMP
998	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
999	default NR_CPUS_DEFAULT
1000	help
1001	  This allows you to specify the maximum number of CPUs which this
1002	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1003	  supported value is 8192, otherwise the maximum value is 512.  The
1004	  minimum value which makes sense is 2.
1005
1006	  This is purely to save memory: each supported CPU adds about 8KB
1007	  to the kernel image.
1008
1009config SCHED_SMT
1010	def_bool y if SMP
1011
1012config SCHED_MC
1013	def_bool y
1014	prompt "Multi-core scheduler support"
1015	depends on SMP
1016	help
1017	  Multi-core scheduler support improves the CPU scheduler's decision
1018	  making when dealing with multi-core CPU chips at a cost of slightly
1019	  increased overhead in some places. If unsure say N here.
1020
1021config SCHED_MC_PRIO
1022	bool "CPU core priorities scheduler support"
1023	depends on SCHED_MC && CPU_SUP_INTEL
1024	select X86_INTEL_PSTATE
1025	select CPU_FREQ
1026	default y
1027	help
1028	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1029	  core ordering determined at manufacturing time, which allows
1030	  certain cores to reach higher turbo frequencies (when running
1031	  single threaded workloads) than others.
1032
1033	  Enabling this kernel feature teaches the scheduler about
1034	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1035	  scheduler's CPU selection logic accordingly, so that higher
1036	  overall system performance can be achieved.
1037
1038	  This feature will have no effect on CPUs without this feature.
1039
1040	  If unsure say Y here.
1041
1042config UP_LATE_INIT
1043	def_bool y
1044	depends on !SMP && X86_LOCAL_APIC
1045
1046config X86_UP_APIC
1047	bool "Local APIC support on uniprocessors" if !PCI_MSI
1048	default PCI_MSI
1049	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1050	help
1051	  A local APIC (Advanced Programmable Interrupt Controller) is an
1052	  integrated interrupt controller in the CPU. If you have a single-CPU
1053	  system which has a processor with a local APIC, you can say Y here to
1054	  enable and use it. If you say Y here even though your machine doesn't
1055	  have a local APIC, then the kernel will still run with no slowdown at
1056	  all. The local APIC supports CPU-generated self-interrupts (timer,
1057	  performance counters), and the NMI watchdog which detects hard
1058	  lockups.
1059
1060config X86_UP_IOAPIC
1061	bool "IO-APIC support on uniprocessors"
1062	depends on X86_UP_APIC
1063	help
1064	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1065	  SMP-capable replacement for PC-style interrupt controllers. Most
1066	  SMP systems and many recent uniprocessor systems have one.
1067
1068	  If you have a single-CPU system with an IO-APIC, you can say Y here
1069	  to use it. If you say Y here even though your machine doesn't have
1070	  an IO-APIC, then the kernel will still run with no slowdown at all.
1071
1072config X86_LOCAL_APIC
1073	def_bool y
1074	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1075	select IRQ_DOMAIN_HIERARCHY
1076	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1077
1078config X86_IO_APIC
1079	def_bool y
1080	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1081
1082config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1083	bool "Reroute for broken boot IRQs"
1084	depends on X86_IO_APIC
1085	help
1086	  This option enables a workaround that fixes a source of
1087	  spurious interrupts. This is recommended when threaded
1088	  interrupt handling is used on systems where the generation of
1089	  superfluous "boot interrupts" cannot be disabled.
1090
1091	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1092	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1093	  kernel does during interrupt handling). On chipsets where this
1094	  boot IRQ generation cannot be disabled, this workaround keeps
1095	  the original IRQ line masked so that only the equivalent "boot
1096	  IRQ" is delivered to the CPUs. The workaround also tells the
1097	  kernel to set up the IRQ handler on the boot IRQ line. In this
1098	  way only one interrupt is delivered to the kernel. Otherwise
1099	  the spurious second interrupt may cause the kernel to bring
1100	  down (vital) interrupt lines.
1101
1102	  Only affects "broken" chipsets. Interrupt sharing may be
1103	  increased on these systems.
1104
1105config X86_MCE
1106	bool "Machine Check / overheating reporting"
1107	select GENERIC_ALLOCATOR
1108	default y
1109	help
1110	  Machine Check support allows the processor to notify the
1111	  kernel if it detects a problem (e.g. overheating, data corruption).
1112	  The action the kernel takes depends on the severity of the problem,
1113	  ranging from warning messages to halting the machine.
1114
1115config X86_MCELOG_LEGACY
1116	bool "Support for deprecated /dev/mcelog character device"
1117	depends on X86_MCE
1118	help
1119	  Enable support for /dev/mcelog which is needed by the old mcelog
1120	  userspace logging daemon. Consider switching to the new generation
1121	  rasdaemon solution.
1122
1123config X86_MCE_INTEL
1124	def_bool y
1125	prompt "Intel MCE features"
1126	depends on X86_MCE && X86_LOCAL_APIC
1127	help
1128	   Additional support for intel specific MCE features such as
1129	   the thermal monitor.
1130
1131config X86_MCE_AMD
1132	def_bool y
1133	prompt "AMD MCE features"
1134	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1135	help
1136	   Additional support for AMD specific MCE features such as
1137	   the DRAM Error Threshold.
1138
1139config X86_ANCIENT_MCE
1140	bool "Support for old Pentium 5 / WinChip machine checks"
1141	depends on X86_32 && X86_MCE
1142	help
1143	  Include support for machine check handling on old Pentium 5 or WinChip
1144	  systems. These typically need to be enabled explicitly on the command
1145	  line.
1146
1147config X86_MCE_THRESHOLD
1148	depends on X86_MCE_AMD || X86_MCE_INTEL
1149	def_bool y
1150
1151config X86_MCE_INJECT
1152	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1153	tristate "Machine check injector support"
1154	help
1155	  Provide support for injecting machine checks for testing purposes.
1156	  If you don't know what a machine check is and you don't do kernel
1157	  QA it is safe to say n.
1158
1159config X86_THERMAL_VECTOR
1160	def_bool y
1161	depends on X86_MCE_INTEL
1162
1163source "arch/x86/events/Kconfig"
1164
1165config X86_LEGACY_VM86
1166	bool "Legacy VM86 support"
1167	depends on X86_32
1168	help
1169	  This option allows user programs to put the CPU into V8086
1170	  mode, which is an 80286-era approximation of 16-bit real mode.
1171
1172	  Some very old versions of X and/or vbetool require this option
1173	  for user mode setting.  Similarly, DOSEMU will use it if
1174	  available to accelerate real mode DOS programs.  However, any
1175	  recent version of DOSEMU, X, or vbetool should be fully
1176	  functional even without kernel VM86 support, as they will all
1177	  fall back to software emulation. Nevertheless, if you are using
1178	  a 16-bit DOS program where 16-bit performance matters, vm86
1179	  mode might be faster than emulation and you might want to
1180	  enable this option.
1181
1182	  Note that any app that works on a 64-bit kernel is unlikely to
1183	  need this option, as 64-bit kernels don't, and can't, support
1184	  V8086 mode. This option is also unrelated to 16-bit protected
1185	  mode and is not needed to run most 16-bit programs under Wine.
1186
1187	  Enabling this option increases the complexity of the kernel
1188	  and slows down exception handling a tiny bit.
1189
1190	  If unsure, say N here.
1191
1192config VM86
1193	bool
1194	default X86_LEGACY_VM86
1195
1196config X86_16BIT
1197	bool "Enable support for 16-bit segments" if EXPERT
1198	default y
1199	depends on MODIFY_LDT_SYSCALL
1200	help
1201	  This option is required by programs like Wine to run 16-bit
1202	  protected mode legacy code on x86 processors.  Disabling
1203	  this option saves about 300 bytes on i386, or around 6K text
1204	  plus 16K runtime memory on x86-64,
1205
1206config X86_ESPFIX32
1207	def_bool y
1208	depends on X86_16BIT && X86_32
1209
1210config X86_ESPFIX64
1211	def_bool y
1212	depends on X86_16BIT && X86_64
1213
1214config X86_VSYSCALL_EMULATION
1215	bool "Enable vsyscall emulation" if EXPERT
1216	default y
1217	depends on X86_64
1218	help
1219	 This enables emulation of the legacy vsyscall page.  Disabling
1220	 it is roughly equivalent to booting with vsyscall=none, except
1221	 that it will also disable the helpful warning if a program
1222	 tries to use a vsyscall.  With this option set to N, offending
1223	 programs will just segfault, citing addresses of the form
1224	 0xffffffffff600?00.
1225
1226	 This option is required by many programs built before 2013, and
1227	 care should be used even with newer programs if set to N.
1228
1229	 Disabling this option saves about 7K of kernel size and
1230	 possibly 4K of additional runtime pagetable memory.
1231
1232config X86_IOPL_IOPERM
1233	bool "IOPERM and IOPL Emulation"
1234	default y
1235	help
1236	  This enables the ioperm() and iopl() syscalls which are necessary
1237	  for legacy applications.
1238
1239	  Legacy IOPL support is an overbroad mechanism which allows user
1240	  space aside of accessing all 65536 I/O ports also to disable
1241	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1242	  capabilities and permission from potentially active security
1243	  modules.
1244
1245	  The emulation restricts the functionality of the syscall to
1246	  only allowing the full range I/O port access, but prevents the
1247	  ability to disable interrupts from user space which would be
1248	  granted if the hardware IOPL mechanism would be used.
1249
1250config TOSHIBA
1251	tristate "Toshiba Laptop support"
1252	depends on X86_32
1253	help
1254	  This adds a driver to safely access the System Management Mode of
1255	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1256	  not work on models with a Phoenix BIOS. The System Management Mode
1257	  is used to set the BIOS and power saving options on Toshiba portables.
1258
1259	  For information on utilities to make use of this driver see the
1260	  Toshiba Linux utilities web site at:
1261	  <http://www.buzzard.org.uk/toshiba/>.
1262
1263	  Say Y if you intend to run this kernel on a Toshiba portable.
1264	  Say N otherwise.
1265
1266config I8K
1267	tristate "Dell i8k legacy laptop support"
1268	select HWMON
1269	select SENSORS_DELL_SMM
1270	help
1271	  This option enables legacy /proc/i8k userspace interface in hwmon
1272	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1273	  temperature and allows controlling fan speeds of Dell laptops via
1274	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1275	  it reports also power and hotkey status. For fan speed control is
1276	  needed userspace package i8kutils.
1277
1278	  Say Y if you intend to run this kernel on old Dell laptops or want to
1279	  use userspace package i8kutils.
1280	  Say N otherwise.
1281
1282config X86_REBOOTFIXUPS
1283	bool "Enable X86 board specific fixups for reboot"
1284	depends on X86_32
1285	help
1286	  This enables chipset and/or board specific fixups to be done
1287	  in order to get reboot to work correctly. This is only needed on
1288	  some combinations of hardware and BIOS. The symptom, for which
1289	  this config is intended, is when reboot ends with a stalled/hung
1290	  system.
1291
1292	  Currently, the only fixup is for the Geode machines using
1293	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1294
1295	  Say Y if you want to enable the fixup. Currently, it's safe to
1296	  enable this option even if you don't need it.
1297	  Say N otherwise.
1298
1299config MICROCODE
1300	bool "CPU microcode loading support"
1301	default y
1302	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1303	help
1304	  If you say Y here, you will be able to update the microcode on
1305	  Intel and AMD processors. The Intel support is for the IA32 family,
1306	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1307	  AMD support is for families 0x10 and later. You will obviously need
1308	  the actual microcode binary data itself which is not shipped with
1309	  the Linux kernel.
1310
1311	  The preferred method to load microcode from a detached initrd is described
1312	  in Documentation/x86/microcode.rst. For that you need to enable
1313	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1314	  initrd for microcode blobs.
1315
1316	  In addition, you can build the microcode into the kernel. For that you
1317	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1318	  config option.
1319
1320config MICROCODE_INTEL
1321	bool "Intel microcode loading support"
1322	depends on MICROCODE
1323	default MICROCODE
1324	help
1325	  This options enables microcode patch loading support for Intel
1326	  processors.
1327
1328	  For the current Intel microcode data package go to
1329	  <https://downloadcenter.intel.com> and search for
1330	  'Linux Processor Microcode Data File'.
1331
1332config MICROCODE_AMD
1333	bool "AMD microcode loading support"
1334	depends on MICROCODE
1335	help
1336	  If you select this option, microcode patch loading support for AMD
1337	  processors will be enabled.
1338
1339config MICROCODE_OLD_INTERFACE
1340	bool "Ancient loading interface (DEPRECATED)"
1341	default n
1342	depends on MICROCODE
1343	help
1344	  DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1345	  which was used by userspace tools like iucode_tool and microcode.ctl.
1346	  It is inadequate because it runs too late to be able to properly
1347	  load microcode on a machine and it needs special tools. Instead, you
1348	  should've switched to the early loading method with the initrd or
1349	  builtin microcode by now: Documentation/x86/microcode.rst
1350
1351config X86_MSR
1352	tristate "/dev/cpu/*/msr - Model-specific register support"
1353	help
1354	  This device gives privileged processes access to the x86
1355	  Model-Specific Registers (MSRs).  It is a character device with
1356	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1357	  MSR accesses are directed to a specific CPU on multi-processor
1358	  systems.
1359
1360config X86_CPUID
1361	tristate "/dev/cpu/*/cpuid - CPU information support"
1362	help
1363	  This device gives processes access to the x86 CPUID instruction to
1364	  be executed on a specific processor.  It is a character device
1365	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1366	  /dev/cpu/31/cpuid.
1367
1368choice
1369	prompt "High Memory Support"
1370	default HIGHMEM4G
1371	depends on X86_32
1372
1373config NOHIGHMEM
1374	bool "off"
1375	help
1376	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1377	  However, the address space of 32-bit x86 processors is only 4
1378	  Gigabytes large. That means that, if you have a large amount of
1379	  physical memory, not all of it can be "permanently mapped" by the
1380	  kernel. The physical memory that's not permanently mapped is called
1381	  "high memory".
1382
1383	  If you are compiling a kernel which will never run on a machine with
1384	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1385	  choice and suitable for most users). This will result in a "3GB/1GB"
1386	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1387	  space and the remaining part of the 4GB virtual memory space is used
1388	  by the kernel to permanently map as much physical memory as
1389	  possible.
1390
1391	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1392	  answer "4GB" here.
1393
1394	  If more than 4 Gigabytes is used then answer "64GB" here. This
1395	  selection turns Intel PAE (Physical Address Extension) mode on.
1396	  PAE implements 3-level paging on IA32 processors. PAE is fully
1397	  supported by Linux, PAE mode is implemented on all recent Intel
1398	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1399	  then the kernel will not boot on CPUs that don't support PAE!
1400
1401	  The actual amount of total physical memory will either be
1402	  auto detected or can be forced by using a kernel command line option
1403	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1404	  your boot loader (lilo or loadlin) about how to pass options to the
1405	  kernel at boot time.)
1406
1407	  If unsure, say "off".
1408
1409config HIGHMEM4G
1410	bool "4GB"
1411	help
1412	  Select this if you have a 32-bit processor and between 1 and 4
1413	  gigabytes of physical RAM.
1414
1415config HIGHMEM64G
1416	bool "64GB"
1417	depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1418	select X86_PAE
1419	help
1420	  Select this if you have a 32-bit processor and more than 4
1421	  gigabytes of physical RAM.
1422
1423endchoice
1424
1425choice
1426	prompt "Memory split" if EXPERT
1427	default VMSPLIT_3G
1428	depends on X86_32
1429	help
1430	  Select the desired split between kernel and user memory.
1431
1432	  If the address range available to the kernel is less than the
1433	  physical memory installed, the remaining memory will be available
1434	  as "high memory". Accessing high memory is a little more costly
1435	  than low memory, as it needs to be mapped into the kernel first.
1436	  Note that increasing the kernel address space limits the range
1437	  available to user programs, making the address space there
1438	  tighter.  Selecting anything other than the default 3G/1G split
1439	  will also likely make your kernel incompatible with binary-only
1440	  kernel modules.
1441
1442	  If you are not absolutely sure what you are doing, leave this
1443	  option alone!
1444
1445	config VMSPLIT_3G
1446		bool "3G/1G user/kernel split"
1447	config VMSPLIT_3G_OPT
1448		depends on !X86_PAE
1449		bool "3G/1G user/kernel split (for full 1G low memory)"
1450	config VMSPLIT_2G
1451		bool "2G/2G user/kernel split"
1452	config VMSPLIT_2G_OPT
1453		depends on !X86_PAE
1454		bool "2G/2G user/kernel split (for full 2G low memory)"
1455	config VMSPLIT_1G
1456		bool "1G/3G user/kernel split"
1457endchoice
1458
1459config PAGE_OFFSET
1460	hex
1461	default 0xB0000000 if VMSPLIT_3G_OPT
1462	default 0x80000000 if VMSPLIT_2G
1463	default 0x78000000 if VMSPLIT_2G_OPT
1464	default 0x40000000 if VMSPLIT_1G
1465	default 0xC0000000
1466	depends on X86_32
1467
1468config HIGHMEM
1469	def_bool y
1470	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1471
1472config X86_PAE
1473	bool "PAE (Physical Address Extension) Support"
1474	depends on X86_32 && !HIGHMEM4G
1475	select PHYS_ADDR_T_64BIT
1476	select SWIOTLB
1477	help
1478	  PAE is required for NX support, and furthermore enables
1479	  larger swapspace support for non-overcommit purposes. It
1480	  has the cost of more pagetable lookup overhead, and also
1481	  consumes more pagetable space per process.
1482
1483config X86_5LEVEL
1484	bool "Enable 5-level page tables support"
1485	default y
1486	select DYNAMIC_MEMORY_LAYOUT
1487	select SPARSEMEM_VMEMMAP
1488	depends on X86_64
1489	help
1490	  5-level paging enables access to larger address space:
1491	  upto 128 PiB of virtual address space and 4 PiB of
1492	  physical address space.
1493
1494	  It will be supported by future Intel CPUs.
1495
1496	  A kernel with the option enabled can be booted on machines that
1497	  support 4- or 5-level paging.
1498
1499	  See Documentation/x86/x86_64/5level-paging.rst for more
1500	  information.
1501
1502	  Say N if unsure.
1503
1504config X86_DIRECT_GBPAGES
1505	def_bool y
1506	depends on X86_64
1507	help
1508	  Certain kernel features effectively disable kernel
1509	  linear 1 GB mappings (even if the CPU otherwise
1510	  supports them), so don't confuse the user by printing
1511	  that we have them enabled.
1512
1513config X86_CPA_STATISTICS
1514	bool "Enable statistic for Change Page Attribute"
1515	depends on DEBUG_FS
1516	help
1517	  Expose statistics about the Change Page Attribute mechanism, which
1518	  helps to determine the effectiveness of preserving large and huge
1519	  page mappings when mapping protections are changed.
1520
1521config AMD_MEM_ENCRYPT
1522	bool "AMD Secure Memory Encryption (SME) support"
1523	depends on X86_64 && CPU_SUP_AMD
1524	select DMA_COHERENT_POOL
1525	select DYNAMIC_PHYSICAL_MASK
1526	select ARCH_USE_MEMREMAP_PROT
1527	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1528	select INSTRUCTION_DECODER
1529	help
1530	  Say yes to enable support for the encryption of system memory.
1531	  This requires an AMD processor that supports Secure Memory
1532	  Encryption (SME).
1533
1534config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1535	bool "Activate AMD Secure Memory Encryption (SME) by default"
1536	default y
1537	depends on AMD_MEM_ENCRYPT
1538	help
1539	  Say yes to have system memory encrypted by default if running on
1540	  an AMD processor that supports Secure Memory Encryption (SME).
1541
1542	  If set to Y, then the encryption of system memory can be
1543	  deactivated with the mem_encrypt=off command line option.
1544
1545	  If set to N, then the encryption of system memory can be
1546	  activated with the mem_encrypt=on command line option.
1547
1548# Common NUMA Features
1549config NUMA
1550	bool "NUMA Memory Allocation and Scheduler Support"
1551	depends on SMP
1552	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1553	default y if X86_BIGSMP
1554	help
1555	  Enable NUMA (Non-Uniform Memory Access) support.
1556
1557	  The kernel will try to allocate memory used by a CPU on the
1558	  local memory controller of the CPU and add some more
1559	  NUMA awareness to the kernel.
1560
1561	  For 64-bit this is recommended if the system is Intel Core i7
1562	  (or later), AMD Opteron, or EM64T NUMA.
1563
1564	  For 32-bit this is only needed if you boot a 32-bit
1565	  kernel on a 64-bit NUMA platform.
1566
1567	  Otherwise, you should say N.
1568
1569config AMD_NUMA
1570	def_bool y
1571	prompt "Old style AMD Opteron NUMA detection"
1572	depends on X86_64 && NUMA && PCI
1573	help
1574	  Enable AMD NUMA node topology detection.  You should say Y here if
1575	  you have a multi processor AMD system. This uses an old method to
1576	  read the NUMA configuration directly from the builtin Northbridge
1577	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1578	  which also takes priority if both are compiled in.
1579
1580config X86_64_ACPI_NUMA
1581	def_bool y
1582	prompt "ACPI NUMA detection"
1583	depends on X86_64 && NUMA && ACPI && PCI
1584	select ACPI_NUMA
1585	help
1586	  Enable ACPI SRAT based node topology detection.
1587
1588config NUMA_EMU
1589	bool "NUMA emulation"
1590	depends on NUMA
1591	help
1592	  Enable NUMA emulation. A flat machine will be split
1593	  into virtual nodes when booted with "numa=fake=N", where N is the
1594	  number of nodes. This is only useful for debugging.
1595
1596config NODES_SHIFT
1597	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1598	range 1 10
1599	default "10" if MAXSMP
1600	default "6" if X86_64
1601	default "3"
1602	depends on NEED_MULTIPLE_NODES
1603	help
1604	  Specify the maximum number of NUMA Nodes available on the target
1605	  system.  Increases memory reserved to accommodate various tables.
1606
1607config ARCH_FLATMEM_ENABLE
1608	def_bool y
1609	depends on X86_32 && !NUMA
1610
1611config ARCH_SPARSEMEM_ENABLE
1612	def_bool y
1613	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1614	select SPARSEMEM_STATIC if X86_32
1615	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1616
1617config ARCH_SPARSEMEM_DEFAULT
1618	def_bool X86_64 || (NUMA && X86_32)
1619
1620config ARCH_SELECT_MEMORY_MODEL
1621	def_bool y
1622	depends on ARCH_SPARSEMEM_ENABLE
1623
1624config ARCH_MEMORY_PROBE
1625	bool "Enable sysfs memory/probe interface"
1626	depends on X86_64 && MEMORY_HOTPLUG
1627	help
1628	  This option enables a sysfs memory/probe interface for testing.
1629	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1630	  If you are unsure how to answer this question, answer N.
1631
1632config ARCH_PROC_KCORE_TEXT
1633	def_bool y
1634	depends on X86_64 && PROC_KCORE
1635
1636config ILLEGAL_POINTER_VALUE
1637	hex
1638	default 0 if X86_32
1639	default 0xdead000000000000 if X86_64
1640
1641config X86_PMEM_LEGACY_DEVICE
1642	bool
1643
1644config X86_PMEM_LEGACY
1645	tristate "Support non-standard NVDIMMs and ADR protected memory"
1646	depends on PHYS_ADDR_T_64BIT
1647	depends on BLK_DEV
1648	select X86_PMEM_LEGACY_DEVICE
1649	select NUMA_KEEP_MEMINFO if NUMA
1650	select LIBNVDIMM
1651	help
1652	  Treat memory marked using the non-standard e820 type of 12 as used
1653	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1654	  The kernel will offer these regions to the 'pmem' driver so
1655	  they can be used for persistent storage.
1656
1657	  Say Y if unsure.
1658
1659config HIGHPTE
1660	bool "Allocate 3rd-level pagetables from highmem"
1661	depends on HIGHMEM
1662	help
1663	  The VM uses one page table entry for each page of physical memory.
1664	  For systems with a lot of RAM, this can be wasteful of precious
1665	  low memory.  Setting this option will put user-space page table
1666	  entries in high memory.
1667
1668config X86_CHECK_BIOS_CORRUPTION
1669	bool "Check for low memory corruption"
1670	help
1671	  Periodically check for memory corruption in low memory, which
1672	  is suspected to be caused by BIOS.  Even when enabled in the
1673	  configuration, it is disabled at runtime.  Enable it by
1674	  setting "memory_corruption_check=1" on the kernel command
1675	  line.  By default it scans the low 64k of memory every 60
1676	  seconds; see the memory_corruption_check_size and
1677	  memory_corruption_check_period parameters in
1678	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1679
1680	  When enabled with the default parameters, this option has
1681	  almost no overhead, as it reserves a relatively small amount
1682	  of memory and scans it infrequently.  It both detects corruption
1683	  and prevents it from affecting the running system.
1684
1685	  It is, however, intended as a diagnostic tool; if repeatable
1686	  BIOS-originated corruption always affects the same memory,
1687	  you can use memmap= to prevent the kernel from using that
1688	  memory.
1689
1690config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1691	bool "Set the default setting of memory_corruption_check"
1692	depends on X86_CHECK_BIOS_CORRUPTION
1693	default y
1694	help
1695	  Set whether the default state of memory_corruption_check is
1696	  on or off.
1697
1698config X86_RESERVE_LOW
1699	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1700	default 64
1701	range 4 640
1702	help
1703	  Specify the amount of low memory to reserve for the BIOS.
1704
1705	  The first page contains BIOS data structures that the kernel
1706	  must not use, so that page must always be reserved.
1707
1708	  By default we reserve the first 64K of physical RAM, as a
1709	  number of BIOSes are known to corrupt that memory range
1710	  during events such as suspend/resume or monitor cable
1711	  insertion, so it must not be used by the kernel.
1712
1713	  You can set this to 4 if you are absolutely sure that you
1714	  trust the BIOS to get all its memory reservations and usages
1715	  right.  If you know your BIOS have problems beyond the
1716	  default 64K area, you can set this to 640 to avoid using the
1717	  entire low memory range.
1718
1719	  If you have doubts about the BIOS (e.g. suspend/resume does
1720	  not work or there's kernel crashes after certain hardware
1721	  hotplug events) then you might want to enable
1722	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1723	  typical corruption patterns.
1724
1725	  Leave this to the default value of 64 if you are unsure.
1726
1727config MATH_EMULATION
1728	bool
1729	depends on MODIFY_LDT_SYSCALL
1730	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1731	help
1732	  Linux can emulate a math coprocessor (used for floating point
1733	  operations) if you don't have one. 486DX and Pentium processors have
1734	  a math coprocessor built in, 486SX and 386 do not, unless you added
1735	  a 487DX or 387, respectively. (The messages during boot time can
1736	  give you some hints here ["man dmesg"].) Everyone needs either a
1737	  coprocessor or this emulation.
1738
1739	  If you don't have a math coprocessor, you need to say Y here; if you
1740	  say Y here even though you have a coprocessor, the coprocessor will
1741	  be used nevertheless. (This behavior can be changed with the kernel
1742	  command line option "no387", which comes handy if your coprocessor
1743	  is broken. Try "man bootparam" or see the documentation of your boot
1744	  loader (lilo or loadlin) about how to pass options to the kernel at
1745	  boot time.) This means that it is a good idea to say Y here if you
1746	  intend to use this kernel on different machines.
1747
1748	  More information about the internals of the Linux math coprocessor
1749	  emulation can be found in <file:arch/x86/math-emu/README>.
1750
1751	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1752	  kernel, it won't hurt.
1753
1754config MTRR
1755	def_bool y
1756	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1757	help
1758	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1759	  the Memory Type Range Registers (MTRRs) may be used to control
1760	  processor access to memory ranges. This is most useful if you have
1761	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1762	  allows bus write transfers to be combined into a larger transfer
1763	  before bursting over the PCI/AGP bus. This can increase performance
1764	  of image write operations 2.5 times or more. Saying Y here creates a
1765	  /proc/mtrr file which may be used to manipulate your processor's
1766	  MTRRs. Typically the X server should use this.
1767
1768	  This code has a reasonably generic interface so that similar
1769	  control registers on other processors can be easily supported
1770	  as well:
1771
1772	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1773	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1774	  these, the ARRs are used to emulate the MTRRs.
1775	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1776	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1777	  write-combining. All of these processors are supported by this code
1778	  and it makes sense to say Y here if you have one of them.
1779
1780	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1781	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1782	  can lead to all sorts of problems, so it's good to say Y here.
1783
1784	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1785	  just add about 9 KB to your kernel.
1786
1787	  See <file:Documentation/x86/mtrr.rst> for more information.
1788
1789config MTRR_SANITIZER
1790	def_bool y
1791	prompt "MTRR cleanup support"
1792	depends on MTRR
1793	help
1794	  Convert MTRR layout from continuous to discrete, so X drivers can
1795	  add writeback entries.
1796
1797	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1798	  The largest mtrr entry size for a continuous block can be set with
1799	  mtrr_chunk_size.
1800
1801	  If unsure, say Y.
1802
1803config MTRR_SANITIZER_ENABLE_DEFAULT
1804	int "MTRR cleanup enable value (0-1)"
1805	range 0 1
1806	default "0"
1807	depends on MTRR_SANITIZER
1808	help
1809	  Enable mtrr cleanup default value
1810
1811config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1812	int "MTRR cleanup spare reg num (0-7)"
1813	range 0 7
1814	default "1"
1815	depends on MTRR_SANITIZER
1816	help
1817	  mtrr cleanup spare entries default, it can be changed via
1818	  mtrr_spare_reg_nr=N on the kernel command line.
1819
1820config X86_PAT
1821	def_bool y
1822	prompt "x86 PAT support" if EXPERT
1823	depends on MTRR
1824	help
1825	  Use PAT attributes to setup page level cache control.
1826
1827	  PATs are the modern equivalents of MTRRs and are much more
1828	  flexible than MTRRs.
1829
1830	  Say N here if you see bootup problems (boot crash, boot hang,
1831	  spontaneous reboots) or a non-working video driver.
1832
1833	  If unsure, say Y.
1834
1835config ARCH_USES_PG_UNCACHED
1836	def_bool y
1837	depends on X86_PAT
1838
1839config ARCH_RANDOM
1840	def_bool y
1841	prompt "x86 architectural random number generator" if EXPERT
1842	help
1843	  Enable the x86 architectural RDRAND instruction
1844	  (Intel Bull Mountain technology) to generate random numbers.
1845	  If supported, this is a high bandwidth, cryptographically
1846	  secure hardware random number generator.
1847
1848config X86_SMAP
1849	def_bool y
1850	prompt "Supervisor Mode Access Prevention" if EXPERT
1851	help
1852	  Supervisor Mode Access Prevention (SMAP) is a security
1853	  feature in newer Intel processors.  There is a small
1854	  performance cost if this enabled and turned on; there is
1855	  also a small increase in the kernel size if this is enabled.
1856
1857	  If unsure, say Y.
1858
1859config X86_UMIP
1860	def_bool y
1861	prompt "User Mode Instruction Prevention" if EXPERT
1862	help
1863	  User Mode Instruction Prevention (UMIP) is a security feature in
1864	  some x86 processors. If enabled, a general protection fault is
1865	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1866	  executed in user mode. These instructions unnecessarily expose
1867	  information about the hardware state.
1868
1869	  The vast majority of applications do not use these instructions.
1870	  For the very few that do, software emulation is provided in
1871	  specific cases in protected and virtual-8086 modes. Emulated
1872	  results are dummy.
1873
1874config X86_INTEL_MEMORY_PROTECTION_KEYS
1875	prompt "Memory Protection Keys"
1876	def_bool y
1877	# Note: only available in 64-bit mode
1878	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1879	select ARCH_USES_HIGH_VMA_FLAGS
1880	select ARCH_HAS_PKEYS
1881	help
1882	  Memory Protection Keys provides a mechanism for enforcing
1883	  page-based protections, but without requiring modification of the
1884	  page tables when an application changes protection domains.
1885
1886	  For details, see Documentation/core-api/protection-keys.rst
1887
1888	  If unsure, say y.
1889
1890choice
1891	prompt "TSX enable mode"
1892	depends on CPU_SUP_INTEL
1893	default X86_INTEL_TSX_MODE_OFF
1894	help
1895	  Intel's TSX (Transactional Synchronization Extensions) feature
1896	  allows to optimize locking protocols through lock elision which
1897	  can lead to a noticeable performance boost.
1898
1899	  On the other hand it has been shown that TSX can be exploited
1900	  to form side channel attacks (e.g. TAA) and chances are there
1901	  will be more of those attacks discovered in the future.
1902
1903	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1904	  might override this decision by tsx=on the command line parameter.
1905	  Even with TSX enabled, the kernel will attempt to enable the best
1906	  possible TAA mitigation setting depending on the microcode available
1907	  for the particular machine.
1908
1909	  This option allows to set the default tsx mode between tsx=on, =off
1910	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1911	  details.
1912
1913	  Say off if not sure, auto if TSX is in use but it should be used on safe
1914	  platforms or on if TSX is in use and the security aspect of tsx is not
1915	  relevant.
1916
1917config X86_INTEL_TSX_MODE_OFF
1918	bool "off"
1919	help
1920	  TSX is disabled if possible - equals to tsx=off command line parameter.
1921
1922config X86_INTEL_TSX_MODE_ON
1923	bool "on"
1924	help
1925	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1926	  line parameter.
1927
1928config X86_INTEL_TSX_MODE_AUTO
1929	bool "auto"
1930	help
1931	  TSX is enabled on TSX capable HW that is believed to be safe against
1932	  side channel attacks- equals the tsx=auto command line parameter.
1933endchoice
1934
1935config X86_SGX
1936	bool "Software Guard eXtensions (SGX)"
1937	depends on X86_64 && CPU_SUP_INTEL
1938	depends on CRYPTO=y
1939	depends on CRYPTO_SHA256=y
1940	select SRCU
1941	select MMU_NOTIFIER
1942	help
1943	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1944	  that can be used by applications to set aside private regions of code
1945	  and data, referred to as enclaves. An enclave's private memory can
1946	  only be accessed by code running within the enclave. Accesses from
1947	  outside the enclave, including other enclaves, are disallowed by
1948	  hardware.
1949
1950	  If unsure, say N.
1951
1952config EFI
1953	bool "EFI runtime service support"
1954	depends on ACPI
1955	select UCS2_STRING
1956	select EFI_RUNTIME_WRAPPERS
1957	help
1958	  This enables the kernel to use EFI runtime services that are
1959	  available (such as the EFI variable services).
1960
1961	  This option is only useful on systems that have EFI firmware.
1962	  In addition, you should use the latest ELILO loader available
1963	  at <http://elilo.sourceforge.net> in order to take advantage
1964	  of EFI runtime services. However, even with this option, the
1965	  resultant kernel should continue to boot on existing non-EFI
1966	  platforms.
1967
1968config EFI_STUB
1969	bool "EFI stub support"
1970	depends on EFI && !X86_USE_3DNOW
1971	depends on $(cc-option,-mabi=ms) || X86_32
1972	select RELOCATABLE
1973	help
1974	  This kernel feature allows a bzImage to be loaded directly
1975	  by EFI firmware without the use of a bootloader.
1976
1977	  See Documentation/admin-guide/efi-stub.rst for more information.
1978
1979config EFI_MIXED
1980	bool "EFI mixed-mode support"
1981	depends on EFI_STUB && X86_64
1982	help
1983	   Enabling this feature allows a 64-bit kernel to be booted
1984	   on a 32-bit firmware, provided that your CPU supports 64-bit
1985	   mode.
1986
1987	   Note that it is not possible to boot a mixed-mode enabled
1988	   kernel via the EFI boot stub - a bootloader that supports
1989	   the EFI handover protocol must be used.
1990
1991	   If unsure, say N.
1992
1993source "kernel/Kconfig.hz"
1994
1995config KEXEC
1996	bool "kexec system call"
1997	select KEXEC_CORE
1998	help
1999	  kexec is a system call that implements the ability to shutdown your
2000	  current kernel, and to start another kernel.  It is like a reboot
2001	  but it is independent of the system firmware.   And like a reboot
2002	  you can start any kernel with it, not just Linux.
2003
2004	  The name comes from the similarity to the exec system call.
2005
2006	  It is an ongoing process to be certain the hardware in a machine
2007	  is properly shutdown, so do not be surprised if this code does not
2008	  initially work for you.  As of this writing the exact hardware
2009	  interface is strongly in flux, so no good recommendation can be
2010	  made.
2011
2012config KEXEC_FILE
2013	bool "kexec file based system call"
2014	select KEXEC_CORE
2015	select BUILD_BIN2C
2016	depends on X86_64
2017	depends on CRYPTO=y
2018	depends on CRYPTO_SHA256=y
2019	help
2020	  This is new version of kexec system call. This system call is
2021	  file based and takes file descriptors as system call argument
2022	  for kernel and initramfs as opposed to list of segments as
2023	  accepted by previous system call.
2024
2025config ARCH_HAS_KEXEC_PURGATORY
2026	def_bool KEXEC_FILE
2027
2028config KEXEC_SIG
2029	bool "Verify kernel signature during kexec_file_load() syscall"
2030	depends on KEXEC_FILE
2031	help
2032
2033	  This option makes the kexec_file_load() syscall check for a valid
2034	  signature of the kernel image.  The image can still be loaded without
2035	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2036	  there's a signature that we can check, then it must be valid.
2037
2038	  In addition to this option, you need to enable signature
2039	  verification for the corresponding kernel image type being
2040	  loaded in order for this to work.
2041
2042config KEXEC_SIG_FORCE
2043	bool "Require a valid signature in kexec_file_load() syscall"
2044	depends on KEXEC_SIG
2045	help
2046	  This option makes kernel signature verification mandatory for
2047	  the kexec_file_load() syscall.
2048
2049config KEXEC_BZIMAGE_VERIFY_SIG
2050	bool "Enable bzImage signature verification support"
2051	depends on KEXEC_SIG
2052	depends on SIGNED_PE_FILE_VERIFICATION
2053	select SYSTEM_TRUSTED_KEYRING
2054	help
2055	  Enable bzImage signature verification support.
2056
2057config CRASH_DUMP
2058	bool "kernel crash dumps"
2059	depends on X86_64 || (X86_32 && HIGHMEM)
2060	help
2061	  Generate crash dump after being started by kexec.
2062	  This should be normally only set in special crash dump kernels
2063	  which are loaded in the main kernel with kexec-tools into
2064	  a specially reserved region and then later executed after
2065	  a crash by kdump/kexec. The crash dump kernel must be compiled
2066	  to a memory address not used by the main kernel or BIOS using
2067	  PHYSICAL_START, or it must be built as a relocatable image
2068	  (CONFIG_RELOCATABLE=y).
2069	  For more details see Documentation/admin-guide/kdump/kdump.rst
2070
2071config KEXEC_JUMP
2072	bool "kexec jump"
2073	depends on KEXEC && HIBERNATION
2074	help
2075	  Jump between original kernel and kexeced kernel and invoke
2076	  code in physical address mode via KEXEC
2077
2078config PHYSICAL_START
2079	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2080	default "0x1000000"
2081	help
2082	  This gives the physical address where the kernel is loaded.
2083
2084	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2085	  bzImage will decompress itself to above physical address and
2086	  run from there. Otherwise, bzImage will run from the address where
2087	  it has been loaded by the boot loader and will ignore above physical
2088	  address.
2089
2090	  In normal kdump cases one does not have to set/change this option
2091	  as now bzImage can be compiled as a completely relocatable image
2092	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2093	  address. This option is mainly useful for the folks who don't want
2094	  to use a bzImage for capturing the crash dump and want to use a
2095	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2096	  to be specifically compiled to run from a specific memory area
2097	  (normally a reserved region) and this option comes handy.
2098
2099	  So if you are using bzImage for capturing the crash dump,
2100	  leave the value here unchanged to 0x1000000 and set
2101	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2102	  for capturing the crash dump change this value to start of
2103	  the reserved region.  In other words, it can be set based on
2104	  the "X" value as specified in the "crashkernel=YM@XM"
2105	  command line boot parameter passed to the panic-ed
2106	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2107	  for more details about crash dumps.
2108
2109	  Usage of bzImage for capturing the crash dump is recommended as
2110	  one does not have to build two kernels. Same kernel can be used
2111	  as production kernel and capture kernel. Above option should have
2112	  gone away after relocatable bzImage support is introduced. But it
2113	  is present because there are users out there who continue to use
2114	  vmlinux for dump capture. This option should go away down the
2115	  line.
2116
2117	  Don't change this unless you know what you are doing.
2118
2119config RELOCATABLE
2120	bool "Build a relocatable kernel"
2121	default y
2122	help
2123	  This builds a kernel image that retains relocation information
2124	  so it can be loaded someplace besides the default 1MB.
2125	  The relocations tend to make the kernel binary about 10% larger,
2126	  but are discarded at runtime.
2127
2128	  One use is for the kexec on panic case where the recovery kernel
2129	  must live at a different physical address than the primary
2130	  kernel.
2131
2132	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2133	  it has been loaded at and the compile time physical address
2134	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2135
2136config RANDOMIZE_BASE
2137	bool "Randomize the address of the kernel image (KASLR)"
2138	depends on RELOCATABLE
2139	default y
2140	help
2141	  In support of Kernel Address Space Layout Randomization (KASLR),
2142	  this randomizes the physical address at which the kernel image
2143	  is decompressed and the virtual address where the kernel
2144	  image is mapped, as a security feature that deters exploit
2145	  attempts relying on knowledge of the location of kernel
2146	  code internals.
2147
2148	  On 64-bit, the kernel physical and virtual addresses are
2149	  randomized separately. The physical address will be anywhere
2150	  between 16MB and the top of physical memory (up to 64TB). The
2151	  virtual address will be randomized from 16MB up to 1GB (9 bits
2152	  of entropy). Note that this also reduces the memory space
2153	  available to kernel modules from 1.5GB to 1GB.
2154
2155	  On 32-bit, the kernel physical and virtual addresses are
2156	  randomized together. They will be randomized from 16MB up to
2157	  512MB (8 bits of entropy).
2158
2159	  Entropy is generated using the RDRAND instruction if it is
2160	  supported. If RDTSC is supported, its value is mixed into
2161	  the entropy pool as well. If neither RDRAND nor RDTSC are
2162	  supported, then entropy is read from the i8254 timer. The
2163	  usable entropy is limited by the kernel being built using
2164	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2165	  minimum of 2MB. As a result, only 10 bits of entropy are
2166	  theoretically possible, but the implementations are further
2167	  limited due to memory layouts.
2168
2169	  If unsure, say Y.
2170
2171# Relocation on x86 needs some additional build support
2172config X86_NEED_RELOCS
2173	def_bool y
2174	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2175
2176config PHYSICAL_ALIGN
2177	hex "Alignment value to which kernel should be aligned"
2178	default "0x200000"
2179	range 0x2000 0x1000000 if X86_32
2180	range 0x200000 0x1000000 if X86_64
2181	help
2182	  This value puts the alignment restrictions on physical address
2183	  where kernel is loaded and run from. Kernel is compiled for an
2184	  address which meets above alignment restriction.
2185
2186	  If bootloader loads the kernel at a non-aligned address and
2187	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2188	  address aligned to above value and run from there.
2189
2190	  If bootloader loads the kernel at a non-aligned address and
2191	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2192	  load address and decompress itself to the address it has been
2193	  compiled for and run from there. The address for which kernel is
2194	  compiled already meets above alignment restrictions. Hence the
2195	  end result is that kernel runs from a physical address meeting
2196	  above alignment restrictions.
2197
2198	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2199	  this value must be a multiple of 0x200000.
2200
2201	  Don't change this unless you know what you are doing.
2202
2203config DYNAMIC_MEMORY_LAYOUT
2204	bool
2205	help
2206	  This option makes base addresses of vmalloc and vmemmap as well as
2207	  __PAGE_OFFSET movable during boot.
2208
2209config RANDOMIZE_MEMORY
2210	bool "Randomize the kernel memory sections"
2211	depends on X86_64
2212	depends on RANDOMIZE_BASE
2213	select DYNAMIC_MEMORY_LAYOUT
2214	default RANDOMIZE_BASE
2215	help
2216	   Randomizes the base virtual address of kernel memory sections
2217	   (physical memory mapping, vmalloc & vmemmap). This security feature
2218	   makes exploits relying on predictable memory locations less reliable.
2219
2220	   The order of allocations remains unchanged. Entropy is generated in
2221	   the same way as RANDOMIZE_BASE. Current implementation in the optimal
2222	   configuration have in average 30,000 different possible virtual
2223	   addresses for each memory section.
2224
2225	   If unsure, say Y.
2226
2227config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2228	hex "Physical memory mapping padding" if EXPERT
2229	depends on RANDOMIZE_MEMORY
2230	default "0xa" if MEMORY_HOTPLUG
2231	default "0x0"
2232	range 0x1 0x40 if MEMORY_HOTPLUG
2233	range 0x0 0x40
2234	help
2235	   Define the padding in terabytes added to the existing physical
2236	   memory size during kernel memory randomization. It is useful
2237	   for memory hotplug support but reduces the entropy available for
2238	   address randomization.
2239
2240	   If unsure, leave at the default value.
2241
2242config HOTPLUG_CPU
2243	def_bool y
2244	depends on SMP
2245
2246config BOOTPARAM_HOTPLUG_CPU0
2247	bool "Set default setting of cpu0_hotpluggable"
2248	depends on HOTPLUG_CPU
2249	help
2250	  Set whether default state of cpu0_hotpluggable is on or off.
2251
2252	  Say Y here to enable CPU0 hotplug by default. If this switch
2253	  is turned on, there is no need to give cpu0_hotplug kernel
2254	  parameter and the CPU0 hotplug feature is enabled by default.
2255
2256	  Please note: there are two known CPU0 dependencies if you want
2257	  to enable the CPU0 hotplug feature either by this switch or by
2258	  cpu0_hotplug kernel parameter.
2259
2260	  First, resume from hibernate or suspend always starts from CPU0.
2261	  So hibernate and suspend are prevented if CPU0 is offline.
2262
2263	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2264	  offline if any interrupt can not migrate out of CPU0. There may
2265	  be other CPU0 dependencies.
2266
2267	  Please make sure the dependencies are under your control before
2268	  you enable this feature.
2269
2270	  Say N if you don't want to enable CPU0 hotplug feature by default.
2271	  You still can enable the CPU0 hotplug feature at boot by kernel
2272	  parameter cpu0_hotplug.
2273
2274config DEBUG_HOTPLUG_CPU0
2275	def_bool n
2276	prompt "Debug CPU0 hotplug"
2277	depends on HOTPLUG_CPU
2278	help
2279	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2280	  soon as possible and boots up userspace with CPU0 offlined. User
2281	  can online CPU0 back after boot time.
2282
2283	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2284	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2285	  compilation or giving cpu0_hotplug kernel parameter at boot.
2286
2287	  If unsure, say N.
2288
2289config COMPAT_VDSO
2290	def_bool n
2291	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2292	depends on COMPAT_32
2293	help
2294	  Certain buggy versions of glibc will crash if they are
2295	  presented with a 32-bit vDSO that is not mapped at the address
2296	  indicated in its segment table.
2297
2298	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2299	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2300	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2301	  the only released version with the bug, but OpenSUSE 9
2302	  contains a buggy "glibc 2.3.2".
2303
2304	  The symptom of the bug is that everything crashes on startup, saying:
2305	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2306
2307	  Saying Y here changes the default value of the vdso32 boot
2308	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2309	  This works around the glibc bug but hurts performance.
2310
2311	  If unsure, say N: if you are compiling your own kernel, you
2312	  are unlikely to be using a buggy version of glibc.
2313
2314choice
2315	prompt "vsyscall table for legacy applications"
2316	depends on X86_64
2317	default LEGACY_VSYSCALL_XONLY
2318	help
2319	  Legacy user code that does not know how to find the vDSO expects
2320	  to be able to issue three syscalls by calling fixed addresses in
2321	  kernel space. Since this location is not randomized with ASLR,
2322	  it can be used to assist security vulnerability exploitation.
2323
2324	  This setting can be changed at boot time via the kernel command
2325	  line parameter vsyscall=[emulate|xonly|none].
2326
2327	  On a system with recent enough glibc (2.14 or newer) and no
2328	  static binaries, you can say None without a performance penalty
2329	  to improve security.
2330
2331	  If unsure, select "Emulate execution only".
2332
2333	config LEGACY_VSYSCALL_EMULATE
2334		bool "Full emulation"
2335		help
2336		  The kernel traps and emulates calls into the fixed vsyscall
2337		  address mapping. This makes the mapping non-executable, but
2338		  it still contains readable known contents, which could be
2339		  used in certain rare security vulnerability exploits. This
2340		  configuration is recommended when using legacy userspace
2341		  that still uses vsyscalls along with legacy binary
2342		  instrumentation tools that require code to be readable.
2343
2344		  An example of this type of legacy userspace is running
2345		  Pin on an old binary that still uses vsyscalls.
2346
2347	config LEGACY_VSYSCALL_XONLY
2348		bool "Emulate execution only"
2349		help
2350		  The kernel traps and emulates calls into the fixed vsyscall
2351		  address mapping and does not allow reads.  This
2352		  configuration is recommended when userspace might use the
2353		  legacy vsyscall area but support for legacy binary
2354		  instrumentation of legacy code is not needed.  It mitigates
2355		  certain uses of the vsyscall area as an ASLR-bypassing
2356		  buffer.
2357
2358	config LEGACY_VSYSCALL_NONE
2359		bool "None"
2360		help
2361		  There will be no vsyscall mapping at all. This will
2362		  eliminate any risk of ASLR bypass due to the vsyscall
2363		  fixed address mapping. Attempts to use the vsyscalls
2364		  will be reported to dmesg, so that either old or
2365		  malicious userspace programs can be identified.
2366
2367endchoice
2368
2369config CMDLINE_BOOL
2370	bool "Built-in kernel command line"
2371	help
2372	  Allow for specifying boot arguments to the kernel at
2373	  build time.  On some systems (e.g. embedded ones), it is
2374	  necessary or convenient to provide some or all of the
2375	  kernel boot arguments with the kernel itself (that is,
2376	  to not rely on the boot loader to provide them.)
2377
2378	  To compile command line arguments into the kernel,
2379	  set this option to 'Y', then fill in the
2380	  boot arguments in CONFIG_CMDLINE.
2381
2382	  Systems with fully functional boot loaders (i.e. non-embedded)
2383	  should leave this option set to 'N'.
2384
2385config CMDLINE
2386	string "Built-in kernel command string"
2387	depends on CMDLINE_BOOL
2388	default ""
2389	help
2390	  Enter arguments here that should be compiled into the kernel
2391	  image and used at boot time.  If the boot loader provides a
2392	  command line at boot time, it is appended to this string to
2393	  form the full kernel command line, when the system boots.
2394
2395	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2396	  change this behavior.
2397
2398	  In most cases, the command line (whether built-in or provided
2399	  by the boot loader) should specify the device for the root
2400	  file system.
2401
2402config CMDLINE_OVERRIDE
2403	bool "Built-in command line overrides boot loader arguments"
2404	depends on CMDLINE_BOOL && CMDLINE != ""
2405	help
2406	  Set this option to 'Y' to have the kernel ignore the boot loader
2407	  command line, and use ONLY the built-in command line.
2408
2409	  This is used to work around broken boot loaders.  This should
2410	  be set to 'N' under normal conditions.
2411
2412config MODIFY_LDT_SYSCALL
2413	bool "Enable the LDT (local descriptor table)" if EXPERT
2414	default y
2415	help
2416	  Linux can allow user programs to install a per-process x86
2417	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2418	  call.  This is required to run 16-bit or segmented code such as
2419	  DOSEMU or some Wine programs.  It is also used by some very old
2420	  threading libraries.
2421
2422	  Enabling this feature adds a small amount of overhead to
2423	  context switches and increases the low-level kernel attack
2424	  surface.  Disabling it removes the modify_ldt(2) system call.
2425
2426	  Saying 'N' here may make sense for embedded or server kernels.
2427
2428source "kernel/livepatch/Kconfig"
2429
2430endmenu
2431
2432config ARCH_HAS_ADD_PAGES
2433	def_bool y
2434	depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2435
2436config ARCH_ENABLE_MEMORY_HOTPLUG
2437	def_bool y
2438	depends on X86_64 || (X86_32 && HIGHMEM)
2439
2440config ARCH_ENABLE_MEMORY_HOTREMOVE
2441	def_bool y
2442	depends on MEMORY_HOTPLUG
2443
2444config USE_PERCPU_NUMA_NODE_ID
2445	def_bool y
2446	depends on NUMA
2447
2448config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2449	def_bool y
2450	depends on X86_64 || X86_PAE
2451
2452config ARCH_ENABLE_HUGEPAGE_MIGRATION
2453	def_bool y
2454	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2455
2456config ARCH_ENABLE_THP_MIGRATION
2457	def_bool y
2458	depends on X86_64 && TRANSPARENT_HUGEPAGE
2459
2460menu "Power management and ACPI options"
2461
2462config ARCH_HIBERNATION_HEADER
2463	def_bool y
2464	depends on HIBERNATION
2465
2466source "kernel/power/Kconfig"
2467
2468source "drivers/acpi/Kconfig"
2469
2470source "drivers/sfi/Kconfig"
2471
2472config X86_APM_BOOT
2473	def_bool y
2474	depends on APM
2475
2476menuconfig APM
2477	tristate "APM (Advanced Power Management) BIOS support"
2478	depends on X86_32 && PM_SLEEP
2479	help
2480	  APM is a BIOS specification for saving power using several different
2481	  techniques. This is mostly useful for battery powered laptops with
2482	  APM compliant BIOSes. If you say Y here, the system time will be
2483	  reset after a RESUME operation, the /proc/apm device will provide
2484	  battery status information, and user-space programs will receive
2485	  notification of APM "events" (e.g. battery status change).
2486
2487	  If you select "Y" here, you can disable actual use of the APM
2488	  BIOS by passing the "apm=off" option to the kernel at boot time.
2489
2490	  Note that the APM support is almost completely disabled for
2491	  machines with more than one CPU.
2492
2493	  In order to use APM, you will need supporting software. For location
2494	  and more information, read <file:Documentation/power/apm-acpi.rst>
2495	  and the Battery Powered Linux mini-HOWTO, available from
2496	  <http://www.tldp.org/docs.html#howto>.
2497
2498	  This driver does not spin down disk drives (see the hdparm(8)
2499	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2500	  VESA-compliant "green" monitors.
2501
2502	  This driver does not support the TI 4000M TravelMate and the ACER
2503	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2504	  desktop machines also don't have compliant BIOSes, and this driver
2505	  may cause those machines to panic during the boot phase.
2506
2507	  Generally, if you don't have a battery in your machine, there isn't
2508	  much point in using this driver and you should say N. If you get
2509	  random kernel OOPSes or reboots that don't seem to be related to
2510	  anything, try disabling/enabling this option (or disabling/enabling
2511	  APM in your BIOS).
2512
2513	  Some other things you should try when experiencing seemingly random,
2514	  "weird" problems:
2515
2516	  1) make sure that you have enough swap space and that it is
2517	  enabled.
2518	  2) pass the "no-hlt" option to the kernel
2519	  3) switch on floating point emulation in the kernel and pass
2520	  the "no387" option to the kernel
2521	  4) pass the "floppy=nodma" option to the kernel
2522	  5) pass the "mem=4M" option to the kernel (thereby disabling
2523	  all but the first 4 MB of RAM)
2524	  6) make sure that the CPU is not over clocked.
2525	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2526	  8) disable the cache from your BIOS settings
2527	  9) install a fan for the video card or exchange video RAM
2528	  10) install a better fan for the CPU
2529	  11) exchange RAM chips
2530	  12) exchange the motherboard.
2531
2532	  To compile this driver as a module, choose M here: the
2533	  module will be called apm.
2534
2535if APM
2536
2537config APM_IGNORE_USER_SUSPEND
2538	bool "Ignore USER SUSPEND"
2539	help
2540	  This option will ignore USER SUSPEND requests. On machines with a
2541	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2542	  series notebooks, it is necessary to say Y because of a BIOS bug.
2543
2544config APM_DO_ENABLE
2545	bool "Enable PM at boot time"
2546	help
2547	  Enable APM features at boot time. From page 36 of the APM BIOS
2548	  specification: "When disabled, the APM BIOS does not automatically
2549	  power manage devices, enter the Standby State, enter the Suspend
2550	  State, or take power saving steps in response to CPU Idle calls."
2551	  This driver will make CPU Idle calls when Linux is idle (unless this
2552	  feature is turned off -- see "Do CPU IDLE calls", below). This
2553	  should always save battery power, but more complicated APM features
2554	  will be dependent on your BIOS implementation. You may need to turn
2555	  this option off if your computer hangs at boot time when using APM
2556	  support, or if it beeps continuously instead of suspending. Turn
2557	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2558	  T400CDT. This is off by default since most machines do fine without
2559	  this feature.
2560
2561config APM_CPU_IDLE
2562	depends on CPU_IDLE
2563	bool "Make CPU Idle calls when idle"
2564	help
2565	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2566	  On some machines, this can activate improved power savings, such as
2567	  a slowed CPU clock rate, when the machine is idle. These idle calls
2568	  are made after the idle loop has run for some length of time (e.g.,
2569	  333 mS). On some machines, this will cause a hang at boot time or
2570	  whenever the CPU becomes idle. (On machines with more than one CPU,
2571	  this option does nothing.)
2572
2573config APM_DISPLAY_BLANK
2574	bool "Enable console blanking using APM"
2575	help
2576	  Enable console blanking using the APM. Some laptops can use this to
2577	  turn off the LCD backlight when the screen blanker of the Linux
2578	  virtual console blanks the screen. Note that this is only used by
2579	  the virtual console screen blanker, and won't turn off the backlight
2580	  when using the X Window system. This also doesn't have anything to
2581	  do with your VESA-compliant power-saving monitor. Further, this
2582	  option doesn't work for all laptops -- it might not turn off your
2583	  backlight at all, or it might print a lot of errors to the console,
2584	  especially if you are using gpm.
2585
2586config APM_ALLOW_INTS
2587	bool "Allow interrupts during APM BIOS calls"
2588	help
2589	  Normally we disable external interrupts while we are making calls to
2590	  the APM BIOS as a measure to lessen the effects of a badly behaving
2591	  BIOS implementation.  The BIOS should reenable interrupts if it
2592	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2593	  many of the newer IBM Thinkpads.  If you experience hangs when you
2594	  suspend, try setting this to Y.  Otherwise, say N.
2595
2596endif # APM
2597
2598source "drivers/cpufreq/Kconfig"
2599
2600source "drivers/cpuidle/Kconfig"
2601
2602source "drivers/idle/Kconfig"
2603
2604endmenu
2605
2606
2607menu "Bus options (PCI etc.)"
2608
2609choice
2610	prompt "PCI access mode"
2611	depends on X86_32 && PCI
2612	default PCI_GOANY
2613	help
2614	  On PCI systems, the BIOS can be used to detect the PCI devices and
2615	  determine their configuration. However, some old PCI motherboards
2616	  have BIOS bugs and may crash if this is done. Also, some embedded
2617	  PCI-based systems don't have any BIOS at all. Linux can also try to
2618	  detect the PCI hardware directly without using the BIOS.
2619
2620	  With this option, you can specify how Linux should detect the
2621	  PCI devices. If you choose "BIOS", the BIOS will be used,
2622	  if you choose "Direct", the BIOS won't be used, and if you
2623	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2624	  If you choose "Any", the kernel will try MMCONFIG, then the
2625	  direct access method and falls back to the BIOS if that doesn't
2626	  work. If unsure, go with the default, which is "Any".
2627
2628config PCI_GOBIOS
2629	bool "BIOS"
2630
2631config PCI_GOMMCONFIG
2632	bool "MMConfig"
2633
2634config PCI_GODIRECT
2635	bool "Direct"
2636
2637config PCI_GOOLPC
2638	bool "OLPC XO-1"
2639	depends on OLPC
2640
2641config PCI_GOANY
2642	bool "Any"
2643
2644endchoice
2645
2646config PCI_BIOS
2647	def_bool y
2648	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2649
2650# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2651config PCI_DIRECT
2652	def_bool y
2653	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2654
2655config PCI_MMCONFIG
2656	bool "Support mmconfig PCI config space access" if X86_64
2657	default y
2658	depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2659	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2660
2661config PCI_OLPC
2662	def_bool y
2663	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2664
2665config PCI_XEN
2666	def_bool y
2667	depends on PCI && XEN
2668	select SWIOTLB_XEN
2669
2670config MMCONF_FAM10H
2671	def_bool y
2672	depends on X86_64 && PCI_MMCONFIG && ACPI
2673
2674config PCI_CNB20LE_QUIRK
2675	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2676	depends on PCI
2677	help
2678	  Read the PCI windows out of the CNB20LE host bridge. This allows
2679	  PCI hotplug to work on systems with the CNB20LE chipset which do
2680	  not have ACPI.
2681
2682	  There's no public spec for this chipset, and this functionality
2683	  is known to be incomplete.
2684
2685	  You should say N unless you know you need this.
2686
2687config ISA_BUS
2688	bool "ISA bus support on modern systems" if EXPERT
2689	help
2690	  Expose ISA bus device drivers and options available for selection and
2691	  configuration. Enable this option if your target machine has an ISA
2692	  bus. ISA is an older system, displaced by PCI and newer bus
2693	  architectures -- if your target machine is modern, it probably does
2694	  not have an ISA bus.
2695
2696	  If unsure, say N.
2697
2698# x86_64 have no ISA slots, but can have ISA-style DMA.
2699config ISA_DMA_API
2700	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2701	default y
2702	help
2703	  Enables ISA-style DMA support for devices requiring such controllers.
2704	  If unsure, say Y.
2705
2706if X86_32
2707
2708config ISA
2709	bool "ISA support"
2710	help
2711	  Find out whether you have ISA slots on your motherboard.  ISA is the
2712	  name of a bus system, i.e. the way the CPU talks to the other stuff
2713	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2714	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2715	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2716
2717config SCx200
2718	tristate "NatSemi SCx200 support"
2719	help
2720	  This provides basic support for National Semiconductor's
2721	  (now AMD's) Geode processors.  The driver probes for the
2722	  PCI-IDs of several on-chip devices, so its a good dependency
2723	  for other scx200_* drivers.
2724
2725	  If compiled as a module, the driver is named scx200.
2726
2727config SCx200HR_TIMER
2728	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2729	depends on SCx200
2730	default y
2731	help
2732	  This driver provides a clocksource built upon the on-chip
2733	  27MHz high-resolution timer.  Its also a workaround for
2734	  NSC Geode SC-1100's buggy TSC, which loses time when the
2735	  processor goes idle (as is done by the scheduler).  The
2736	  other workaround is idle=poll boot option.
2737
2738config OLPC
2739	bool "One Laptop Per Child support"
2740	depends on !X86_PAE
2741	select GPIOLIB
2742	select OF
2743	select OF_PROMTREE
2744	select IRQ_DOMAIN
2745	select OLPC_EC
2746	help
2747	  Add support for detecting the unique features of the OLPC
2748	  XO hardware.
2749
2750config OLPC_XO1_PM
2751	bool "OLPC XO-1 Power Management"
2752	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2753	help
2754	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2755
2756config OLPC_XO1_RTC
2757	bool "OLPC XO-1 Real Time Clock"
2758	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2759	help
2760	  Add support for the XO-1 real time clock, which can be used as a
2761	  programmable wakeup source.
2762
2763config OLPC_XO1_SCI
2764	bool "OLPC XO-1 SCI extras"
2765	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2766	depends on INPUT=y
2767	select POWER_SUPPLY
2768	help
2769	  Add support for SCI-based features of the OLPC XO-1 laptop:
2770	   - EC-driven system wakeups
2771	   - Power button
2772	   - Ebook switch
2773	   - Lid switch
2774	   - AC adapter status updates
2775	   - Battery status updates
2776
2777config OLPC_XO15_SCI
2778	bool "OLPC XO-1.5 SCI extras"
2779	depends on OLPC && ACPI
2780	select POWER_SUPPLY
2781	help
2782	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2783	   - EC-driven system wakeups
2784	   - AC adapter status updates
2785	   - Battery status updates
2786
2787config ALIX
2788	bool "PCEngines ALIX System Support (LED setup)"
2789	select GPIOLIB
2790	help
2791	  This option enables system support for the PCEngines ALIX.
2792	  At present this just sets up LEDs for GPIO control on
2793	  ALIX2/3/6 boards.  However, other system specific setup should
2794	  get added here.
2795
2796	  Note: You must still enable the drivers for GPIO and LED support
2797	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2798
2799	  Note: You have to set alix.force=1 for boards with Award BIOS.
2800
2801config NET5501
2802	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2803	select GPIOLIB
2804	help
2805	  This option enables system support for the Soekris Engineering net5501.
2806
2807config GEOS
2808	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2809	select GPIOLIB
2810	depends on DMI
2811	help
2812	  This option enables system support for the Traverse Technologies GEOS.
2813
2814config TS5500
2815	bool "Technologic Systems TS-5500 platform support"
2816	depends on MELAN
2817	select CHECK_SIGNATURE
2818	select NEW_LEDS
2819	select LEDS_CLASS
2820	help
2821	  This option enables system support for the Technologic Systems TS-5500.
2822
2823endif # X86_32
2824
2825config AMD_NB
2826	def_bool y
2827	depends on CPU_SUP_AMD && PCI
2828
2829config X86_SYSFB
2830	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2831	help
2832	  Firmwares often provide initial graphics framebuffers so the BIOS,
2833	  bootloader or kernel can show basic video-output during boot for
2834	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2835	  Extensions and EFI-framebuffers for this, which are mostly limited
2836	  to x86.
2837	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2838	  framebuffers so the new generic system-framebuffer drivers can be
2839	  used on x86. If the framebuffer is not compatible with the generic
2840	  modes, it is advertised as fallback platform framebuffer so legacy
2841	  drivers like efifb, vesafb and uvesafb can pick it up.
2842	  If this option is not selected, all system framebuffers are always
2843	  marked as fallback platform framebuffers as usual.
2844
2845	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2846	  not be able to pick up generic system framebuffers if this option
2847	  is selected. You are highly encouraged to enable simplefb as
2848	  replacement if you select this option. simplefb can correctly deal
2849	  with generic system framebuffers. But you should still keep vesafb
2850	  and others enabled as fallback if a system framebuffer is
2851	  incompatible with simplefb.
2852
2853	  If unsure, say Y.
2854
2855endmenu
2856
2857
2858menu "Binary Emulations"
2859
2860config IA32_EMULATION
2861	bool "IA32 Emulation"
2862	depends on X86_64
2863	select ARCH_WANT_OLD_COMPAT_IPC
2864	select BINFMT_ELF
2865	select COMPAT_BINFMT_ELF
2866	select COMPAT_OLD_SIGACTION
2867	help
2868	  Include code to run legacy 32-bit programs under a
2869	  64-bit kernel. You should likely turn this on, unless you're
2870	  100% sure that you don't have any 32-bit programs left.
2871
2872config IA32_AOUT
2873	tristate "IA32 a.out support"
2874	depends on IA32_EMULATION
2875	depends on BROKEN
2876	help
2877	  Support old a.out binaries in the 32bit emulation.
2878
2879config X86_X32
2880	bool "x32 ABI for 64-bit mode"
2881	depends on X86_64
2882	help
2883	  Include code to run binaries for the x32 native 32-bit ABI
2884	  for 64-bit processors.  An x32 process gets access to the
2885	  full 64-bit register file and wide data path while leaving
2886	  pointers at 32 bits for smaller memory footprint.
2887
2888	  You will need a recent binutils (2.22 or later) with
2889	  elf32_x86_64 support enabled to compile a kernel with this
2890	  option set.
2891
2892config COMPAT_32
2893	def_bool y
2894	depends on IA32_EMULATION || X86_32
2895	select HAVE_UID16
2896	select OLD_SIGSUSPEND3
2897
2898config COMPAT
2899	def_bool y
2900	depends on IA32_EMULATION || X86_X32
2901
2902if COMPAT
2903config COMPAT_FOR_U64_ALIGNMENT
2904	def_bool y
2905
2906config SYSVIPC_COMPAT
2907	def_bool y
2908	depends on SYSVIPC
2909endif
2910
2911endmenu
2912
2913
2914config HAVE_ATOMIC_IOMAP
2915	def_bool y
2916	depends on X86_32
2917
2918source "drivers/firmware/Kconfig"
2919
2920source "arch/x86/kvm/Kconfig"
2921
2922source "arch/x86/Kconfig.assembler"
2923