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	select ARCH_SPLIT_ARG64
23
24config X86_64
25	def_bool y
26	depends on 64BIT
27	# Options that are inherently 64-bit kernel only:
28	select ARCH_HAS_GIGANTIC_PAGE
29	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
30	select ARCH_SUPPORTS_PER_VMA_LOCK
31	select HAVE_ARCH_SOFT_DIRTY
32	select MODULES_USE_ELF_RELA
33	select NEED_DMA_MAP_STATE
34	select SWIOTLB
35	select ARCH_HAS_ELFCORE_COMPAT
36	select ZONE_DMA32
37
38config FORCE_DYNAMIC_FTRACE
39	def_bool y
40	depends on X86_32
41	depends on FUNCTION_TRACER
42	select DYNAMIC_FTRACE
43	help
44	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45	  in order to test the non static function tracing in the
46	  generic code, as other architectures still use it. But we
47	  only need to keep it around for x86_64. No need to keep it
48	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49#
50# Arch settings
51#
52# ( Note that options that are marked 'if X86_64' could in principle be
53#   ported to 32-bit as well. )
54#
55config X86
56	def_bool y
57	#
58	# Note: keep this list sorted alphabetically
59	#
60	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
61	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62	select ACPI_HOTPLUG_CPU			if ACPI_PROCESSOR && HOTPLUG_CPU
63	select ARCH_32BIT_OFF_T			if X86_32
64	select ARCH_CLOCKSOURCE_INIT
65	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
66	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
67	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
68	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
69	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
70	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
71	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
72	select ARCH_HAS_CACHE_LINE_SIZE
73	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
74	select ARCH_HAS_CPU_FINALIZE_INIT
75	select ARCH_HAS_CPU_PASID		if IOMMU_SVA
76	select ARCH_HAS_CURRENT_STACK_POINTER
77	select ARCH_HAS_DEBUG_VIRTUAL
78	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
79	select ARCH_HAS_DEVMEM_IS_ALLOWED
80	select ARCH_HAS_EARLY_DEBUG		if KGDB
81	select ARCH_HAS_ELF_RANDOMIZE
82	select ARCH_HAS_FAST_MULTIPLIER
83	select ARCH_HAS_FORTIFY_SOURCE
84	select ARCH_HAS_GCOV_PROFILE_ALL
85	select ARCH_HAS_KCOV			if X86_64
86	select ARCH_HAS_MEM_ENCRYPT
87	select ARCH_HAS_MEMBARRIER_SYNC_CORE
88	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
89	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
90	select ARCH_HAS_PMEM_API		if X86_64
91	select ARCH_HAS_PTE_DEVMAP		if X86_64
92	select ARCH_HAS_PTE_SPECIAL
93	select ARCH_HAS_HW_PTE_YOUNG
94	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
95	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
96	select ARCH_HAS_COPY_MC			if X86_64
97	select ARCH_HAS_SET_MEMORY
98	select ARCH_HAS_SET_DIRECT_MAP
99	select ARCH_HAS_STRICT_KERNEL_RWX
100	select ARCH_HAS_STRICT_MODULE_RWX
101	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
102	select ARCH_HAS_SYSCALL_WRAPPER
103	select ARCH_HAS_UBSAN
104	select ARCH_HAS_DEBUG_WX
105	select ARCH_HAS_ZONE_DMA_SET if EXPERT
106	select ARCH_HAVE_NMI_SAFE_CMPXCHG
107	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
108	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
109	select ARCH_MIGHT_HAVE_PC_PARPORT
110	select ARCH_MIGHT_HAVE_PC_SERIO
111	select ARCH_STACKWALK
112	select ARCH_SUPPORTS_ACPI
113	select ARCH_SUPPORTS_ATOMIC_RMW
114	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
115	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
116	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
117	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
118	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
119	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
120	select ARCH_SUPPORTS_LTO_CLANG
121	select ARCH_SUPPORTS_LTO_CLANG_THIN
122	select ARCH_USE_BUILTIN_BSWAP
123	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CMPXCHG64
124	select ARCH_USE_MEMTEST
125	select ARCH_USE_QUEUED_RWLOCKS
126	select ARCH_USE_QUEUED_SPINLOCKS
127	select ARCH_USE_SYM_ANNOTATIONS
128	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
129	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
130	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
131	select ARCH_WANTS_NO_INSTR
132	select ARCH_WANT_GENERAL_HUGETLB
133	select ARCH_WANT_HUGE_PMD_SHARE
134	select ARCH_WANT_LD_ORPHAN_WARN
135	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
136	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
137	select ARCH_WANTS_THP_SWAP		if X86_64
138	select ARCH_HAS_PARANOID_L1D_FLUSH
139	select BUILDTIME_TABLE_SORT
140	select CLKEVT_I8253
141	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
142	select CLOCKSOURCE_WATCHDOG
143	# Word-size accesses may read uninitialized data past the trailing \0
144	# in strings and cause false KMSAN reports.
145	select DCACHE_WORD_ACCESS		if !KMSAN
146	select DYNAMIC_SIGFRAME
147	select EDAC_ATOMIC_SCRUB
148	select EDAC_SUPPORT
149	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
150	select GENERIC_CLOCKEVENTS_BROADCAST_IDLE	if GENERIC_CLOCKEVENTS_BROADCAST
151	select GENERIC_CLOCKEVENTS_MIN_ADJUST
152	select GENERIC_CMOS_UPDATE
153	select GENERIC_CPU_AUTOPROBE
154	select GENERIC_CPU_DEVICES
155	select GENERIC_CPU_VULNERABILITIES
156	select GENERIC_EARLY_IOREMAP
157	select GENERIC_ENTRY
158	select GENERIC_IOMAP
159	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
160	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
161	select GENERIC_IRQ_MIGRATION		if SMP
162	select GENERIC_IRQ_PROBE
163	select GENERIC_IRQ_RESERVATION_MODE
164	select GENERIC_IRQ_SHOW
165	select GENERIC_PENDING_IRQ		if SMP
166	select GENERIC_PTDUMP
167	select GENERIC_SMP_IDLE_THREAD
168	select GENERIC_TIME_VSYSCALL
169	select GENERIC_GETTIMEOFDAY
170	select GENERIC_VDSO_TIME_NS
171	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
172	select HARDIRQS_SW_RESEND
173	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
174	select HAS_IOPORT
175	select HAVE_ACPI_APEI			if ACPI
176	select HAVE_ACPI_APEI_NMI		if ACPI
177	select HAVE_ALIGNED_STRUCT_PAGE
178	select HAVE_ARCH_AUDITSYSCALL
179	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
180	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
181	select HAVE_ARCH_JUMP_LABEL
182	select HAVE_ARCH_JUMP_LABEL_RELATIVE
183	select HAVE_ARCH_KASAN			if X86_64
184	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
185	select HAVE_ARCH_KFENCE
186	select HAVE_ARCH_KMSAN			if X86_64
187	select HAVE_ARCH_KGDB
188	select HAVE_ARCH_MMAP_RND_BITS		if MMU
189	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
190	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
191	select HAVE_ARCH_PREL32_RELOCATIONS
192	select HAVE_ARCH_SECCOMP_FILTER
193	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
194	select HAVE_ARCH_STACKLEAK
195	select HAVE_ARCH_TRACEHOOK
196	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
197	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
198	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
199	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
200	select HAVE_ARCH_VMAP_STACK		if X86_64
201	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
202	select HAVE_ARCH_WITHIN_STACK_FRAMES
203	select HAVE_ASM_MODVERSIONS
204	select HAVE_CMPXCHG_DOUBLE
205	select HAVE_CMPXCHG_LOCAL
206	select HAVE_CONTEXT_TRACKING_USER		if X86_64
207	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
208	select HAVE_C_RECORDMCOUNT
209	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
210	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
211	select HAVE_BUILDTIME_MCOUNT_SORT
212	select HAVE_DEBUG_KMEMLEAK
213	select HAVE_DMA_CONTIGUOUS
214	select HAVE_DYNAMIC_FTRACE
215	select HAVE_DYNAMIC_FTRACE_WITH_REGS
216	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
217	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
218	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
219	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
220	select HAVE_EBPF_JIT
221	select HAVE_EFFICIENT_UNALIGNED_ACCESS
222	select HAVE_EISA
223	select HAVE_EXIT_THREAD
224	select HAVE_FAST_GUP
225	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
226	select HAVE_FTRACE_MCOUNT_RECORD
227	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
228	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
229	select HAVE_FUNCTION_TRACER
230	select HAVE_GCC_PLUGINS
231	select HAVE_HW_BREAKPOINT
232	select HAVE_IOREMAP_PROT
233	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
234	select HAVE_IRQ_TIME_ACCOUNTING
235	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
236	select HAVE_KERNEL_BZIP2
237	select HAVE_KERNEL_GZIP
238	select HAVE_KERNEL_LZ4
239	select HAVE_KERNEL_LZMA
240	select HAVE_KERNEL_LZO
241	select HAVE_KERNEL_XZ
242	select HAVE_KERNEL_ZSTD
243	select HAVE_KPROBES
244	select HAVE_KPROBES_ON_FTRACE
245	select HAVE_FUNCTION_ERROR_INJECTION
246	select HAVE_KRETPROBES
247	select HAVE_RETHOOK
248	select HAVE_LIVEPATCH			if X86_64
249	select HAVE_MIXED_BREAKPOINTS_REGS
250	select HAVE_MOD_ARCH_SPECIFIC
251	select HAVE_MOVE_PMD
252	select HAVE_MOVE_PUD
253	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
254	select HAVE_NMI
255	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
256	select HAVE_OBJTOOL			if X86_64
257	select HAVE_OPTPROBES
258	select HAVE_PAGE_SIZE_4KB
259	select HAVE_PCSPKR_PLATFORM
260	select HAVE_PERF_EVENTS
261	select HAVE_PERF_EVENTS_NMI
262	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
263	select HAVE_PCI
264	select HAVE_PERF_REGS
265	select HAVE_PERF_USER_STACK_DUMP
266	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
267	select MMU_GATHER_MERGE_VMAS
268	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
269	select HAVE_REGS_AND_STACK_ACCESS_API
270	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
271	select HAVE_FUNCTION_ARG_ACCESS_API
272	select HAVE_SETUP_PER_CPU_AREA
273	select HAVE_SOFTIRQ_ON_OWN_STACK
274	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
275	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
276	select HAVE_STATIC_CALL
277	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
278	select HAVE_PREEMPT_DYNAMIC_CALL
279	select HAVE_RSEQ
280	select HAVE_RUST			if X86_64
281	select HAVE_SYSCALL_TRACEPOINTS
282	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
283	select HAVE_UNSTABLE_SCHED_CLOCK
284	select HAVE_USER_RETURN_NOTIFIER
285	select HAVE_GENERIC_VDSO
286	select HOTPLUG_PARALLEL			if SMP && X86_64
287	select HOTPLUG_SMT			if SMP
288	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
289	select IRQ_FORCED_THREADING
290	select LOCK_MM_AND_FIND_VMA
291	select NEED_PER_CPU_EMBED_FIRST_CHUNK
292	select NEED_PER_CPU_PAGE_FIRST_CHUNK
293	select NEED_SG_DMA_LENGTH
294	select PCI_DOMAINS			if PCI
295	select PCI_LOCKLESS_CONFIG		if PCI
296	select PERF_EVENTS
297	select RTC_LIB
298	select RTC_MC146818_LIB
299	select SPARSE_IRQ
300	select SYSCTL_EXCEPTION_TRACE
301	select THREAD_INFO_IN_TASK
302	select TRACE_IRQFLAGS_SUPPORT
303	select TRACE_IRQFLAGS_NMI_SUPPORT
304	select USER_STACKTRACE_SUPPORT
305	select HAVE_ARCH_KCSAN			if X86_64
306	select PROC_PID_ARCH_STATUS		if PROC_FS
307	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
308	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
309	select FUNCTION_ALIGNMENT_4B
310	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
311	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
312
313config INSTRUCTION_DECODER
314	def_bool y
315	depends on KPROBES || PERF_EVENTS || UPROBES
316
317config OUTPUT_FORMAT
318	string
319	default "elf32-i386" if X86_32
320	default "elf64-x86-64" if X86_64
321
322config LOCKDEP_SUPPORT
323	def_bool y
324
325config STACKTRACE_SUPPORT
326	def_bool y
327
328config MMU
329	def_bool y
330
331config ARCH_MMAP_RND_BITS_MIN
332	default 28 if 64BIT
333	default 8
334
335config ARCH_MMAP_RND_BITS_MAX
336	default 32 if 64BIT
337	default 16
338
339config ARCH_MMAP_RND_COMPAT_BITS_MIN
340	default 8
341
342config ARCH_MMAP_RND_COMPAT_BITS_MAX
343	default 16
344
345config SBUS
346	bool
347
348config GENERIC_ISA_DMA
349	def_bool y
350	depends on ISA_DMA_API
351
352config GENERIC_CSUM
353	bool
354	default y if KMSAN || KASAN
355
356config GENERIC_BUG
357	def_bool y
358	depends on BUG
359	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
360
361config GENERIC_BUG_RELATIVE_POINTERS
362	bool
363
364config ARCH_MAY_HAVE_PC_FDC
365	def_bool y
366	depends on ISA_DMA_API
367
368config GENERIC_CALIBRATE_DELAY
369	def_bool y
370
371config ARCH_HAS_CPU_RELAX
372	def_bool y
373
374config ARCH_HIBERNATION_POSSIBLE
375	def_bool y
376
377config ARCH_SUSPEND_POSSIBLE
378	def_bool y
379
380config AUDIT_ARCH
381	def_bool y if X86_64
382
383config KASAN_SHADOW_OFFSET
384	hex
385	depends on KASAN
386	default 0xdffffc0000000000
387
388config HAVE_INTEL_TXT
389	def_bool y
390	depends on INTEL_IOMMU && ACPI
391
392config X86_64_SMP
393	def_bool y
394	depends on X86_64 && SMP
395
396config ARCH_SUPPORTS_UPROBES
397	def_bool y
398
399config FIX_EARLYCON_MEM
400	def_bool y
401
402config DYNAMIC_PHYSICAL_MASK
403	bool
404
405config PGTABLE_LEVELS
406	int
407	default 5 if X86_5LEVEL
408	default 4 if X86_64
409	default 3 if X86_PAE
410	default 2
411
412config CC_HAS_SANE_STACKPROTECTOR
413	bool
414	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
415	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
416	help
417	  We have to make sure stack protector is unconditionally disabled if
418	  the compiler produces broken code or if it does not let us control
419	  the segment on 32-bit kernels.
420
421menu "Processor type and features"
422
423config SMP
424	bool "Symmetric multi-processing support"
425	help
426	  This enables support for systems with more than one CPU. If you have
427	  a system with only one CPU, say N. If you have a system with more
428	  than one CPU, say Y.
429
430	  If you say N here, the kernel will run on uni- and multiprocessor
431	  machines, but will use only one CPU of a multiprocessor machine. If
432	  you say Y here, the kernel will run on many, but not all,
433	  uniprocessor machines. On a uniprocessor machine, the kernel
434	  will run faster if you say N here.
435
436	  Note that if you say Y here and choose architecture "586" or
437	  "Pentium" under "Processor family", the kernel will not work on 486
438	  architectures. Similarly, multiprocessor kernels for the "PPro"
439	  architecture may not work on all Pentium based boards.
440
441	  People using multiprocessor machines who say Y here should also say
442	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
443	  Management" code will be disabled if you say Y here.
444
445	  See also <file:Documentation/arch/x86/i386/IO-APIC.rst>,
446	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
447	  <http://www.tldp.org/docs.html#howto>.
448
449	  If you don't know what to do here, say N.
450
451config X86_X2APIC
452	bool "Support x2apic"
453	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
454	help
455	  This enables x2apic support on CPUs that have this feature.
456
457	  This allows 32-bit apic IDs (so it can support very large systems),
458	  and accesses the local apic via MSRs not via mmio.
459
460	  Some Intel systems circa 2022 and later are locked into x2APIC mode
461	  and can not fall back to the legacy APIC modes if SGX or TDX are
462	  enabled in the BIOS. They will boot with very reduced functionality
463	  without enabling this option.
464
465	  If you don't know what to do here, say N.
466
467config X86_MPPARSE
468	bool "Enable MPS table" if ACPI
469	default y
470	depends on X86_LOCAL_APIC
471	help
472	  For old smp systems that do not have proper acpi support. Newer systems
473	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
474
475config X86_CPU_RESCTRL
476	bool "x86 CPU resource control support"
477	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
478	select KERNFS
479	select PROC_CPU_RESCTRL		if PROC_FS
480	help
481	  Enable x86 CPU resource control support.
482
483	  Provide support for the allocation and monitoring of system resources
484	  usage by the CPU.
485
486	  Intel calls this Intel Resource Director Technology
487	  (Intel(R) RDT). More information about RDT can be found in the
488	  Intel x86 Architecture Software Developer Manual.
489
490	  AMD calls this AMD Platform Quality of Service (AMD QoS).
491	  More information about AMD QoS can be found in the AMD64 Technology
492	  Platform Quality of Service Extensions manual.
493
494	  Say N if unsure.
495
496config X86_FRED
497	bool "Flexible Return and Event Delivery"
498	depends on X86_64
499	help
500	  When enabled, try to use Flexible Return and Event Delivery
501	  instead of the legacy SYSCALL/SYSENTER/IDT architecture for
502	  ring transitions and exception/interrupt handling if the
503	  system supports.
504
505if X86_32
506config X86_BIGSMP
507	bool "Support for big SMP systems with more than 8 CPUs"
508	depends on SMP
509	help
510	  This option is needed for the systems that have more than 8 CPUs.
511
512config X86_EXTENDED_PLATFORM
513	bool "Support for extended (non-PC) x86 platforms"
514	default y
515	help
516	  If you disable this option then the kernel will only support
517	  standard PC platforms. (which covers the vast majority of
518	  systems out there.)
519
520	  If you enable this option then you'll be able to select support
521	  for the following (non-PC) 32 bit x86 platforms:
522		Goldfish (Android emulator)
523		AMD Elan
524		RDC R-321x SoC
525		SGI 320/540 (Visual Workstation)
526		STA2X11-based (e.g. Northville)
527		Moorestown MID devices
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 # X86_32
532
533if X86_64
534config X86_EXTENDED_PLATFORM
535	bool "Support for extended (non-PC) x86 platforms"
536	default y
537	help
538	  If you disable this option then the kernel will only support
539	  standard PC platforms. (which covers the vast majority of
540	  systems out there.)
541
542	  If you enable this option then you'll be able to select support
543	  for the following (non-PC) 64 bit x86 platforms:
544		Numascale NumaChip
545		ScaleMP vSMP
546		SGI Ultraviolet
547
548	  If you have one of these systems, or if you want to build a
549	  generic distribution kernel, say Y here - otherwise say N.
550endif # X86_64
551# This is an alphabetically sorted list of 64 bit extended platforms
552# Please maintain the alphabetic order if and when there are additions
553config X86_NUMACHIP
554	bool "Numascale NumaChip"
555	depends on X86_64
556	depends on X86_EXTENDED_PLATFORM
557	depends on NUMA
558	depends on SMP
559	depends on X86_X2APIC
560	depends on PCI_MMCONFIG
561	help
562	  Adds support for Numascale NumaChip large-SMP systems. Needed to
563	  enable more than ~168 cores.
564	  If you don't have one of these, you should say N here.
565
566config X86_VSMP
567	bool "ScaleMP vSMP"
568	select HYPERVISOR_GUEST
569	select PARAVIRT
570	depends on X86_64 && PCI
571	depends on X86_EXTENDED_PLATFORM
572	depends on SMP
573	help
574	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
575	  supposed to run on these EM64T-based machines.  Only choose this option
576	  if you have one of these machines.
577
578config X86_UV
579	bool "SGI Ultraviolet"
580	depends on X86_64
581	depends on X86_EXTENDED_PLATFORM
582	depends on NUMA
583	depends on EFI
584	depends on KEXEC_CORE
585	depends on X86_X2APIC
586	depends on PCI
587	help
588	  This option is needed in order to support SGI Ultraviolet systems.
589	  If you don't have one of these, you should say N here.
590
591# Following is an alphabetically sorted list of 32 bit extended platforms
592# Please maintain the alphabetic order if and when there are additions
593
594config X86_GOLDFISH
595	bool "Goldfish (Virtual Platform)"
596	depends on X86_EXTENDED_PLATFORM
597	help
598	  Enable support for the Goldfish virtual platform used primarily
599	  for Android development. Unless you are building for the Android
600	  Goldfish emulator say N here.
601
602config X86_INTEL_CE
603	bool "CE4100 TV platform"
604	depends on PCI
605	depends on PCI_GODIRECT
606	depends on X86_IO_APIC
607	depends on X86_32
608	depends on X86_EXTENDED_PLATFORM
609	select X86_REBOOTFIXUPS
610	select OF
611	select OF_EARLY_FLATTREE
612	help
613	  Select for the Intel CE media processor (CE4100) SOC.
614	  This option compiles in support for the CE4100 SOC for settop
615	  boxes and media devices.
616
617config X86_INTEL_MID
618	bool "Intel MID platform support"
619	depends on X86_EXTENDED_PLATFORM
620	depends on X86_PLATFORM_DEVICES
621	depends on PCI
622	depends on X86_64 || (PCI_GOANY && X86_32)
623	depends on X86_IO_APIC
624	select I2C
625	select DW_APB_TIMER
626	select INTEL_SCU_PCI
627	help
628	  Select to build a kernel capable of supporting Intel MID (Mobile
629	  Internet Device) platform systems which do not have the PCI legacy
630	  interfaces. If you are building for a PC class system say N here.
631
632	  Intel MID platforms are based on an Intel processor and chipset which
633	  consume less power than most of the x86 derivatives.
634
635config X86_INTEL_QUARK
636	bool "Intel Quark platform support"
637	depends on X86_32
638	depends on X86_EXTENDED_PLATFORM
639	depends on X86_PLATFORM_DEVICES
640	depends on X86_TSC
641	depends on PCI
642	depends on PCI_GOANY
643	depends on X86_IO_APIC
644	select IOSF_MBI
645	select INTEL_IMR
646	select COMMON_CLK
647	help
648	  Select to include support for Quark X1000 SoC.
649	  Say Y here if you have a Quark based system such as the Arduino
650	  compatible Intel Galileo.
651
652config X86_INTEL_LPSS
653	bool "Intel Low Power Subsystem Support"
654	depends on X86 && ACPI && PCI
655	select COMMON_CLK
656	select PINCTRL
657	select IOSF_MBI
658	help
659	  Select to build support for Intel Low Power Subsystem such as
660	  found on Intel Lynxpoint PCH. Selecting this option enables
661	  things like clock tree (common clock framework) and pincontrol
662	  which are needed by the LPSS peripheral drivers.
663
664config X86_AMD_PLATFORM_DEVICE
665	bool "AMD ACPI2Platform devices support"
666	depends on ACPI
667	select COMMON_CLK
668	select PINCTRL
669	help
670	  Select to interpret AMD specific ACPI device to platform device
671	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
672	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
673	  implemented under PINCTRL subsystem.
674
675config IOSF_MBI
676	tristate "Intel SoC IOSF Sideband support for SoC platforms"
677	depends on PCI
678	help
679	  This option enables sideband register access support for Intel SoC
680	  platforms. On these platforms the IOSF sideband is used in lieu of
681	  MSR's for some register accesses, mostly but not limited to thermal
682	  and power. Drivers may query the availability of this device to
683	  determine if they need the sideband in order to work on these
684	  platforms. The sideband is available on the following SoC products.
685	  This list is not meant to be exclusive.
686	   - BayTrail
687	   - Braswell
688	   - Quark
689
690	  You should say Y if you are running a kernel on one of these SoC's.
691
692config IOSF_MBI_DEBUG
693	bool "Enable IOSF sideband access through debugfs"
694	depends on IOSF_MBI && DEBUG_FS
695	help
696	  Select this option to expose the IOSF sideband access registers (MCR,
697	  MDR, MCRX) through debugfs to write and read register information from
698	  different units on the SoC. This is most useful for obtaining device
699	  state information for debug and analysis. As this is a general access
700	  mechanism, users of this option would have specific knowledge of the
701	  device they want to access.
702
703	  If you don't require the option or are in doubt, say N.
704
705config X86_RDC321X
706	bool "RDC R-321x SoC"
707	depends on X86_32
708	depends on X86_EXTENDED_PLATFORM
709	select M486
710	select X86_REBOOTFIXUPS
711	help
712	  This option is needed for RDC R-321x system-on-chip, also known
713	  as R-8610-(G).
714	  If you don't have one of these chips, you should say N here.
715
716config X86_32_NON_STANDARD
717	bool "Support non-standard 32-bit SMP architectures"
718	depends on X86_32 && SMP
719	depends on X86_EXTENDED_PLATFORM
720	help
721	  This option compiles in the bigsmp and STA2X11 default
722	  subarchitectures.  It is intended for a generic binary
723	  kernel. If you select them all, kernel will probe it one by
724	  one and will fallback to default.
725
726# Alphabetically sorted list of Non standard 32 bit platforms
727
728config X86_SUPPORTS_MEMORY_FAILURE
729	def_bool y
730	# MCE code calls memory_failure():
731	depends on X86_MCE
732	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
733	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
734	depends on X86_64 || !SPARSEMEM
735	select ARCH_SUPPORTS_MEMORY_FAILURE
736
737config STA2X11
738	bool "STA2X11 Companion Chip Support"
739	depends on X86_32_NON_STANDARD && PCI
740	select SWIOTLB
741	select MFD_STA2X11
742	select GPIOLIB
743	help
744	  This adds support for boards based on the STA2X11 IO-Hub,
745	  a.k.a. "ConneXt". The chip is used in place of the standard
746	  PC chipset, so all "standard" peripherals are missing. If this
747	  option is selected the kernel will still be able to boot on
748	  standard PC machines.
749
750config X86_32_IRIS
751	tristate "Eurobraille/Iris poweroff module"
752	depends on X86_32
753	help
754	  The Iris machines from EuroBraille do not have APM or ACPI support
755	  to shut themselves down properly.  A special I/O sequence is
756	  needed to do so, which is what this module does at
757	  kernel shutdown.
758
759	  This is only for Iris machines from EuroBraille.
760
761	  If unused, say N.
762
763config SCHED_OMIT_FRAME_POINTER
764	def_bool y
765	prompt "Single-depth WCHAN output"
766	depends on X86
767	help
768	  Calculate simpler /proc/<PID>/wchan values. If this option
769	  is disabled then wchan values will recurse back to the
770	  caller function. This provides more accurate wchan values,
771	  at the expense of slightly more scheduling overhead.
772
773	  If in doubt, say "Y".
774
775menuconfig HYPERVISOR_GUEST
776	bool "Linux guest support"
777	help
778	  Say Y here to enable options for running Linux under various hyper-
779	  visors. This option enables basic hypervisor detection and platform
780	  setup.
781
782	  If you say N, all options in this submenu will be skipped and
783	  disabled, and Linux guest support won't be built in.
784
785if HYPERVISOR_GUEST
786
787config PARAVIRT
788	bool "Enable paravirtualization code"
789	depends on HAVE_STATIC_CALL
790	help
791	  This changes the kernel so it can modify itself when it is run
792	  under a hypervisor, potentially improving performance significantly
793	  over full virtualization.  However, when run without a hypervisor
794	  the kernel is theoretically slower and slightly larger.
795
796config PARAVIRT_XXL
797	bool
798
799config PARAVIRT_DEBUG
800	bool "paravirt-ops debugging"
801	depends on PARAVIRT && DEBUG_KERNEL
802	help
803	  Enable to debug paravirt_ops internals.  Specifically, BUG if
804	  a paravirt_op is missing when it is called.
805
806config PARAVIRT_SPINLOCKS
807	bool "Paravirtualization layer for spinlocks"
808	depends on PARAVIRT && SMP
809	help
810	  Paravirtualized spinlocks allow a pvops backend to replace the
811	  spinlock implementation with something virtualization-friendly
812	  (for example, block the virtual CPU rather than spinning).
813
814	  It has a minimal impact on native kernels and gives a nice performance
815	  benefit on paravirtualized KVM / Xen kernels.
816
817	  If you are unsure how to answer this question, answer Y.
818
819config X86_HV_CALLBACK_VECTOR
820	def_bool n
821
822source "arch/x86/xen/Kconfig"
823
824config KVM_GUEST
825	bool "KVM Guest support (including kvmclock)"
826	depends on PARAVIRT
827	select PARAVIRT_CLOCK
828	select ARCH_CPUIDLE_HALTPOLL
829	select X86_HV_CALLBACK_VECTOR
830	default y
831	help
832	  This option enables various optimizations for running under the KVM
833	  hypervisor. It includes a paravirtualized clock, so that instead
834	  of relying on a PIT (or probably other) emulation by the
835	  underlying device model, the host provides the guest with
836	  timing infrastructure such as time of day, and system time
837
838config ARCH_CPUIDLE_HALTPOLL
839	def_bool n
840	prompt "Disable host haltpoll when loading haltpoll driver"
841	help
842	  If virtualized under KVM, disable host haltpoll.
843
844config PVH
845	bool "Support for running PVH guests"
846	help
847	  This option enables the PVH entry point for guest virtual machines
848	  as specified in the x86/HVM direct boot ABI.
849
850config PARAVIRT_TIME_ACCOUNTING
851	bool "Paravirtual steal time accounting"
852	depends on PARAVIRT
853	help
854	  Select this option to enable fine granularity task steal time
855	  accounting. Time spent executing other tasks in parallel with
856	  the current vCPU is discounted from the vCPU power. To account for
857	  that, there can be a small performance impact.
858
859	  If in doubt, say N here.
860
861config PARAVIRT_CLOCK
862	bool
863
864config JAILHOUSE_GUEST
865	bool "Jailhouse non-root cell support"
866	depends on X86_64 && PCI
867	select X86_PM_TIMER
868	help
869	  This option allows to run Linux as guest in a Jailhouse non-root
870	  cell. You can leave this option disabled if you only want to start
871	  Jailhouse and run Linux afterwards in the root cell.
872
873config ACRN_GUEST
874	bool "ACRN Guest support"
875	depends on X86_64
876	select X86_HV_CALLBACK_VECTOR
877	help
878	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
879	  a flexible, lightweight reference open-source hypervisor, built with
880	  real-time and safety-criticality in mind. It is built for embedded
881	  IOT with small footprint and real-time features. More details can be
882	  found in https://projectacrn.org/.
883
884config INTEL_TDX_GUEST
885	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
886	depends on X86_64 && CPU_SUP_INTEL
887	depends on X86_X2APIC
888	depends on EFI_STUB
889	select ARCH_HAS_CC_PLATFORM
890	select X86_MEM_ENCRYPT
891	select X86_MCE
892	select UNACCEPTED_MEMORY
893	help
894	  Support running as a guest under Intel TDX.  Without this support,
895	  the guest kernel can not boot or run under TDX.
896	  TDX includes memory encryption and integrity capabilities
897	  which protect the confidentiality and integrity of guest
898	  memory contents and CPU state. TDX guests are protected from
899	  some attacks from the VMM.
900
901endif # HYPERVISOR_GUEST
902
903source "arch/x86/Kconfig.cpu"
904
905config HPET_TIMER
906	def_bool X86_64
907	prompt "HPET Timer Support" if X86_32
908	help
909	  Use the IA-PC HPET (High Precision Event Timer) to manage
910	  time in preference to the PIT and RTC, if a HPET is
911	  present.
912	  HPET is the next generation timer replacing legacy 8254s.
913	  The HPET provides a stable time base on SMP
914	  systems, unlike the TSC, but it is more expensive to access,
915	  as it is off-chip.  The interface used is documented
916	  in the HPET spec, revision 1.
917
918	  You can safely choose Y here.  However, HPET will only be
919	  activated if the platform and the BIOS support this feature.
920	  Otherwise the 8254 will be used for timing services.
921
922	  Choose N to continue using the legacy 8254 timer.
923
924config HPET_EMULATE_RTC
925	def_bool y
926	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
927
928# Mark as expert because too many people got it wrong.
929# The code disables itself when not needed.
930config DMI
931	default y
932	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
933	bool "Enable DMI scanning" if EXPERT
934	help
935	  Enabled scanning of DMI to identify machine quirks. Say Y
936	  here unless you have verified that your setup is not
937	  affected by entries in the DMI blacklist. Required by PNP
938	  BIOS code.
939
940config GART_IOMMU
941	bool "Old AMD GART IOMMU support"
942	select DMA_OPS
943	select IOMMU_HELPER
944	select SWIOTLB
945	depends on X86_64 && PCI && AMD_NB
946	help
947	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
948	  GART based hardware IOMMUs.
949
950	  The GART supports full DMA access for devices with 32-bit access
951	  limitations, on systems with more than 3 GB. This is usually needed
952	  for USB, sound, many IDE/SATA chipsets and some other devices.
953
954	  Newer systems typically have a modern AMD IOMMU, supported via
955	  the CONFIG_AMD_IOMMU=y config option.
956
957	  In normal configurations this driver is only active when needed:
958	  there's more than 3 GB of memory and the system contains a
959	  32-bit limited device.
960
961	  If unsure, say Y.
962
963config BOOT_VESA_SUPPORT
964	bool
965	help
966	  If true, at least one selected framebuffer driver can take advantage
967	  of VESA video modes set at an early boot stage via the vga= parameter.
968
969config MAXSMP
970	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
971	depends on X86_64 && SMP && DEBUG_KERNEL
972	select CPUMASK_OFFSTACK
973	help
974	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
975	  If unsure, say N.
976
977#
978# The maximum number of CPUs supported:
979#
980# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
981# and which can be configured interactively in the
982# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
983#
984# The ranges are different on 32-bit and 64-bit kernels, depending on
985# hardware capabilities and scalability features of the kernel.
986#
987# ( If MAXSMP is enabled we just use the highest possible value and disable
988#   interactive configuration. )
989#
990
991config NR_CPUS_RANGE_BEGIN
992	int
993	default NR_CPUS_RANGE_END if MAXSMP
994	default    1 if !SMP
995	default    2
996
997config NR_CPUS_RANGE_END
998	int
999	depends on X86_32
1000	default   64 if  SMP &&  X86_BIGSMP
1001	default    8 if  SMP && !X86_BIGSMP
1002	default    1 if !SMP
1003
1004config NR_CPUS_RANGE_END
1005	int
1006	depends on X86_64
1007	default 8192 if  SMP && CPUMASK_OFFSTACK
1008	default  512 if  SMP && !CPUMASK_OFFSTACK
1009	default    1 if !SMP
1010
1011config NR_CPUS_DEFAULT
1012	int
1013	depends on X86_32
1014	default   32 if  X86_BIGSMP
1015	default    8 if  SMP
1016	default    1 if !SMP
1017
1018config NR_CPUS_DEFAULT
1019	int
1020	depends on X86_64
1021	default 8192 if  MAXSMP
1022	default   64 if  SMP
1023	default    1 if !SMP
1024
1025config NR_CPUS
1026	int "Maximum number of CPUs" if SMP && !MAXSMP
1027	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1028	default NR_CPUS_DEFAULT
1029	help
1030	  This allows you to specify the maximum number of CPUs which this
1031	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1032	  supported value is 8192, otherwise the maximum value is 512.  The
1033	  minimum value which makes sense is 2.
1034
1035	  This is purely to save memory: each supported CPU adds about 8KB
1036	  to the kernel image.
1037
1038config SCHED_CLUSTER
1039	bool "Cluster scheduler support"
1040	depends on SMP
1041	default y
1042	help
1043	  Cluster scheduler support improves the CPU scheduler's decision
1044	  making when dealing with machines that have clusters of CPUs.
1045	  Cluster usually means a couple of CPUs which are placed closely
1046	  by sharing mid-level caches, last-level cache tags or internal
1047	  busses.
1048
1049config SCHED_SMT
1050	def_bool y if SMP
1051
1052config SCHED_MC
1053	def_bool y
1054	prompt "Multi-core scheduler support"
1055	depends on SMP
1056	help
1057	  Multi-core scheduler support improves the CPU scheduler's decision
1058	  making when dealing with multi-core CPU chips at a cost of slightly
1059	  increased overhead in some places. If unsure say N here.
1060
1061config SCHED_MC_PRIO
1062	bool "CPU core priorities scheduler support"
1063	depends on SCHED_MC
1064	select X86_INTEL_PSTATE if CPU_SUP_INTEL
1065	select X86_AMD_PSTATE if CPU_SUP_AMD && ACPI
1066	select CPU_FREQ
1067	default y
1068	help
1069	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1070	  core ordering determined at manufacturing time, which allows
1071	  certain cores to reach higher turbo frequencies (when running
1072	  single threaded workloads) than others.
1073
1074	  Enabling this kernel feature teaches the scheduler about
1075	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1076	  scheduler's CPU selection logic accordingly, so that higher
1077	  overall system performance can be achieved.
1078
1079	  This feature will have no effect on CPUs without this feature.
1080
1081	  If unsure say Y here.
1082
1083config UP_LATE_INIT
1084	def_bool y
1085	depends on !SMP && X86_LOCAL_APIC
1086
1087config X86_UP_APIC
1088	bool "Local APIC support on uniprocessors" if !PCI_MSI
1089	default PCI_MSI
1090	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1091	help
1092	  A local APIC (Advanced Programmable Interrupt Controller) is an
1093	  integrated interrupt controller in the CPU. If you have a single-CPU
1094	  system which has a processor with a local APIC, you can say Y here to
1095	  enable and use it. If you say Y here even though your machine doesn't
1096	  have a local APIC, then the kernel will still run with no slowdown at
1097	  all. The local APIC supports CPU-generated self-interrupts (timer,
1098	  performance counters), and the NMI watchdog which detects hard
1099	  lockups.
1100
1101config X86_UP_IOAPIC
1102	bool "IO-APIC support on uniprocessors"
1103	depends on X86_UP_APIC
1104	help
1105	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1106	  SMP-capable replacement for PC-style interrupt controllers. Most
1107	  SMP systems and many recent uniprocessor systems have one.
1108
1109	  If you have a single-CPU system with an IO-APIC, you can say Y here
1110	  to use it. If you say Y here even though your machine doesn't have
1111	  an IO-APIC, then the kernel will still run with no slowdown at all.
1112
1113config X86_LOCAL_APIC
1114	def_bool y
1115	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1116	select IRQ_DOMAIN_HIERARCHY
1117
1118config X86_IO_APIC
1119	def_bool y
1120	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1121
1122config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1123	bool "Reroute for broken boot IRQs"
1124	depends on X86_IO_APIC
1125	help
1126	  This option enables a workaround that fixes a source of
1127	  spurious interrupts. This is recommended when threaded
1128	  interrupt handling is used on systems where the generation of
1129	  superfluous "boot interrupts" cannot be disabled.
1130
1131	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1132	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1133	  kernel does during interrupt handling). On chipsets where this
1134	  boot IRQ generation cannot be disabled, this workaround keeps
1135	  the original IRQ line masked so that only the equivalent "boot
1136	  IRQ" is delivered to the CPUs. The workaround also tells the
1137	  kernel to set up the IRQ handler on the boot IRQ line. In this
1138	  way only one interrupt is delivered to the kernel. Otherwise
1139	  the spurious second interrupt may cause the kernel to bring
1140	  down (vital) interrupt lines.
1141
1142	  Only affects "broken" chipsets. Interrupt sharing may be
1143	  increased on these systems.
1144
1145config X86_MCE
1146	bool "Machine Check / overheating reporting"
1147	select GENERIC_ALLOCATOR
1148	default y
1149	help
1150	  Machine Check support allows the processor to notify the
1151	  kernel if it detects a problem (e.g. overheating, data corruption).
1152	  The action the kernel takes depends on the severity of the problem,
1153	  ranging from warning messages to halting the machine.
1154
1155config X86_MCELOG_LEGACY
1156	bool "Support for deprecated /dev/mcelog character device"
1157	depends on X86_MCE
1158	help
1159	  Enable support for /dev/mcelog which is needed by the old mcelog
1160	  userspace logging daemon. Consider switching to the new generation
1161	  rasdaemon solution.
1162
1163config X86_MCE_INTEL
1164	def_bool y
1165	prompt "Intel MCE features"
1166	depends on X86_MCE && X86_LOCAL_APIC
1167	help
1168	  Additional support for intel specific MCE features such as
1169	  the thermal monitor.
1170
1171config X86_MCE_AMD
1172	def_bool y
1173	prompt "AMD MCE features"
1174	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1175	help
1176	  Additional support for AMD specific MCE features such as
1177	  the DRAM Error Threshold.
1178
1179config X86_ANCIENT_MCE
1180	bool "Support for old Pentium 5 / WinChip machine checks"
1181	depends on X86_32 && X86_MCE
1182	help
1183	  Include support for machine check handling on old Pentium 5 or WinChip
1184	  systems. These typically need to be enabled explicitly on the command
1185	  line.
1186
1187config X86_MCE_THRESHOLD
1188	depends on X86_MCE_AMD || X86_MCE_INTEL
1189	def_bool y
1190
1191config X86_MCE_INJECT
1192	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1193	tristate "Machine check injector support"
1194	help
1195	  Provide support for injecting machine checks for testing purposes.
1196	  If you don't know what a machine check is and you don't do kernel
1197	  QA it is safe to say n.
1198
1199source "arch/x86/events/Kconfig"
1200
1201config X86_LEGACY_VM86
1202	bool "Legacy VM86 support"
1203	depends on X86_32
1204	help
1205	  This option allows user programs to put the CPU into V8086
1206	  mode, which is an 80286-era approximation of 16-bit real mode.
1207
1208	  Some very old versions of X and/or vbetool require this option
1209	  for user mode setting.  Similarly, DOSEMU will use it if
1210	  available to accelerate real mode DOS programs.  However, any
1211	  recent version of DOSEMU, X, or vbetool should be fully
1212	  functional even without kernel VM86 support, as they will all
1213	  fall back to software emulation. Nevertheless, if you are using
1214	  a 16-bit DOS program where 16-bit performance matters, vm86
1215	  mode might be faster than emulation and you might want to
1216	  enable this option.
1217
1218	  Note that any app that works on a 64-bit kernel is unlikely to
1219	  need this option, as 64-bit kernels don't, and can't, support
1220	  V8086 mode. This option is also unrelated to 16-bit protected
1221	  mode and is not needed to run most 16-bit programs under Wine.
1222
1223	  Enabling this option increases the complexity of the kernel
1224	  and slows down exception handling a tiny bit.
1225
1226	  If unsure, say N here.
1227
1228config VM86
1229	bool
1230	default X86_LEGACY_VM86
1231
1232config X86_16BIT
1233	bool "Enable support for 16-bit segments" if EXPERT
1234	default y
1235	depends on MODIFY_LDT_SYSCALL
1236	help
1237	  This option is required by programs like Wine to run 16-bit
1238	  protected mode legacy code on x86 processors.  Disabling
1239	  this option saves about 300 bytes on i386, or around 6K text
1240	  plus 16K runtime memory on x86-64,
1241
1242config X86_ESPFIX32
1243	def_bool y
1244	depends on X86_16BIT && X86_32
1245
1246config X86_ESPFIX64
1247	def_bool y
1248	depends on X86_16BIT && X86_64
1249
1250config X86_VSYSCALL_EMULATION
1251	bool "Enable vsyscall emulation" if EXPERT
1252	default y
1253	depends on X86_64
1254	help
1255	  This enables emulation of the legacy vsyscall page.  Disabling
1256	  it is roughly equivalent to booting with vsyscall=none, except
1257	  that it will also disable the helpful warning if a program
1258	  tries to use a vsyscall.  With this option set to N, offending
1259	  programs will just segfault, citing addresses of the form
1260	  0xffffffffff600?00.
1261
1262	  This option is required by many programs built before 2013, and
1263	  care should be used even with newer programs if set to N.
1264
1265	  Disabling this option saves about 7K of kernel size and
1266	  possibly 4K of additional runtime pagetable memory.
1267
1268config X86_IOPL_IOPERM
1269	bool "IOPERM and IOPL Emulation"
1270	default y
1271	help
1272	  This enables the ioperm() and iopl() syscalls which are necessary
1273	  for legacy applications.
1274
1275	  Legacy IOPL support is an overbroad mechanism which allows user
1276	  space aside of accessing all 65536 I/O ports also to disable
1277	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1278	  capabilities and permission from potentially active security
1279	  modules.
1280
1281	  The emulation restricts the functionality of the syscall to
1282	  only allowing the full range I/O port access, but prevents the
1283	  ability to disable interrupts from user space which would be
1284	  granted if the hardware IOPL mechanism would be used.
1285
1286config TOSHIBA
1287	tristate "Toshiba Laptop support"
1288	depends on X86_32
1289	help
1290	  This adds a driver to safely access the System Management Mode of
1291	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1292	  not work on models with a Phoenix BIOS. The System Management Mode
1293	  is used to set the BIOS and power saving options on Toshiba portables.
1294
1295	  For information on utilities to make use of this driver see the
1296	  Toshiba Linux utilities web site at:
1297	  <http://www.buzzard.org.uk/toshiba/>.
1298
1299	  Say Y if you intend to run this kernel on a Toshiba portable.
1300	  Say N otherwise.
1301
1302config X86_REBOOTFIXUPS
1303	bool "Enable X86 board specific fixups for reboot"
1304	depends on X86_32
1305	help
1306	  This enables chipset and/or board specific fixups to be done
1307	  in order to get reboot to work correctly. This is only needed on
1308	  some combinations of hardware and BIOS. The symptom, for which
1309	  this config is intended, is when reboot ends with a stalled/hung
1310	  system.
1311
1312	  Currently, the only fixup is for the Geode machines using
1313	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1314
1315	  Say Y if you want to enable the fixup. Currently, it's safe to
1316	  enable this option even if you don't need it.
1317	  Say N otherwise.
1318
1319config MICROCODE
1320	def_bool y
1321	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1322
1323config MICROCODE_INITRD32
1324	def_bool y
1325	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1326
1327config MICROCODE_LATE_LOADING
1328	bool "Late microcode loading (DANGEROUS)"
1329	default n
1330	depends on MICROCODE && SMP
1331	help
1332	  Loading microcode late, when the system is up and executing instructions
1333	  is a tricky business and should be avoided if possible. Just the sequence
1334	  of synchronizing all cores and SMT threads is one fragile dance which does
1335	  not guarantee that cores might not softlock after the loading. Therefore,
1336	  use this at your own risk. Late loading taints the kernel unless the
1337	  microcode header indicates that it is safe for late loading via the
1338	  minimal revision check. This minimal revision check can be enforced on
1339	  the kernel command line with "microcode.minrev=Y".
1340
1341config MICROCODE_LATE_FORCE_MINREV
1342	bool "Enforce late microcode loading minimal revision check"
1343	default n
1344	depends on MICROCODE_LATE_LOADING
1345	help
1346	  To prevent that users load microcode late which modifies already
1347	  in use features, newer microcode patches have a minimum revision field
1348	  in the microcode header, which tells the kernel which minimum
1349	  revision must be active in the CPU to safely load that new microcode
1350	  late into the running system. If disabled the check will not
1351	  be enforced but the kernel will be tainted when the minimal
1352	  revision check fails.
1353
1354	  This minimal revision check can also be controlled via the
1355	  "microcode.minrev" parameter on the kernel command line.
1356
1357	  If unsure say Y.
1358
1359config X86_MSR
1360	tristate "/dev/cpu/*/msr - Model-specific register support"
1361	help
1362	  This device gives privileged processes access to the x86
1363	  Model-Specific Registers (MSRs).  It is a character device with
1364	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1365	  MSR accesses are directed to a specific CPU on multi-processor
1366	  systems.
1367
1368config X86_CPUID
1369	tristate "/dev/cpu/*/cpuid - CPU information support"
1370	help
1371	  This device gives processes access to the x86 CPUID instruction to
1372	  be executed on a specific processor.  It is a character device
1373	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1374	  /dev/cpu/31/cpuid.
1375
1376choice
1377	prompt "High Memory Support"
1378	default HIGHMEM4G
1379	depends on X86_32
1380
1381config NOHIGHMEM
1382	bool "off"
1383	help
1384	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1385	  However, the address space of 32-bit x86 processors is only 4
1386	  Gigabytes large. That means that, if you have a large amount of
1387	  physical memory, not all of it can be "permanently mapped" by the
1388	  kernel. The physical memory that's not permanently mapped is called
1389	  "high memory".
1390
1391	  If you are compiling a kernel which will never run on a machine with
1392	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1393	  choice and suitable for most users). This will result in a "3GB/1GB"
1394	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1395	  space and the remaining part of the 4GB virtual memory space is used
1396	  by the kernel to permanently map as much physical memory as
1397	  possible.
1398
1399	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1400	  answer "4GB" here.
1401
1402	  If more than 4 Gigabytes is used then answer "64GB" here. This
1403	  selection turns Intel PAE (Physical Address Extension) mode on.
1404	  PAE implements 3-level paging on IA32 processors. PAE is fully
1405	  supported by Linux, PAE mode is implemented on all recent Intel
1406	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1407	  then the kernel will not boot on CPUs that don't support PAE!
1408
1409	  The actual amount of total physical memory will either be
1410	  auto detected or can be forced by using a kernel command line option
1411	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1412	  your boot loader (lilo or loadlin) about how to pass options to the
1413	  kernel at boot time.)
1414
1415	  If unsure, say "off".
1416
1417config HIGHMEM4G
1418	bool "4GB"
1419	help
1420	  Select this if you have a 32-bit processor and between 1 and 4
1421	  gigabytes of physical RAM.
1422
1423config HIGHMEM64G
1424	bool "64GB"
1425	depends on X86_HAVE_PAE
1426	select X86_PAE
1427	help
1428	  Select this if you have a 32-bit processor and more than 4
1429	  gigabytes of physical RAM.
1430
1431endchoice
1432
1433choice
1434	prompt "Memory split" if EXPERT
1435	default VMSPLIT_3G
1436	depends on X86_32
1437	help
1438	  Select the desired split between kernel and user memory.
1439
1440	  If the address range available to the kernel is less than the
1441	  physical memory installed, the remaining memory will be available
1442	  as "high memory". Accessing high memory is a little more costly
1443	  than low memory, as it needs to be mapped into the kernel first.
1444	  Note that increasing the kernel address space limits the range
1445	  available to user programs, making the address space there
1446	  tighter.  Selecting anything other than the default 3G/1G split
1447	  will also likely make your kernel incompatible with binary-only
1448	  kernel modules.
1449
1450	  If you are not absolutely sure what you are doing, leave this
1451	  option alone!
1452
1453	config VMSPLIT_3G
1454		bool "3G/1G user/kernel split"
1455	config VMSPLIT_3G_OPT
1456		depends on !X86_PAE
1457		bool "3G/1G user/kernel split (for full 1G low memory)"
1458	config VMSPLIT_2G
1459		bool "2G/2G user/kernel split"
1460	config VMSPLIT_2G_OPT
1461		depends on !X86_PAE
1462		bool "2G/2G user/kernel split (for full 2G low memory)"
1463	config VMSPLIT_1G
1464		bool "1G/3G user/kernel split"
1465endchoice
1466
1467config PAGE_OFFSET
1468	hex
1469	default 0xB0000000 if VMSPLIT_3G_OPT
1470	default 0x80000000 if VMSPLIT_2G
1471	default 0x78000000 if VMSPLIT_2G_OPT
1472	default 0x40000000 if VMSPLIT_1G
1473	default 0xC0000000
1474	depends on X86_32
1475
1476config HIGHMEM
1477	def_bool y
1478	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1479
1480config X86_PAE
1481	bool "PAE (Physical Address Extension) Support"
1482	depends on X86_32 && X86_HAVE_PAE
1483	select PHYS_ADDR_T_64BIT
1484	select SWIOTLB
1485	help
1486	  PAE is required for NX support, and furthermore enables
1487	  larger swapspace support for non-overcommit purposes. It
1488	  has the cost of more pagetable lookup overhead, and also
1489	  consumes more pagetable space per process.
1490
1491config X86_5LEVEL
1492	bool "Enable 5-level page tables support"
1493	default y
1494	select DYNAMIC_MEMORY_LAYOUT
1495	select SPARSEMEM_VMEMMAP
1496	depends on X86_64
1497	help
1498	  5-level paging enables access to larger address space:
1499	  up to 128 PiB of virtual address space and 4 PiB of
1500	  physical address space.
1501
1502	  It will be supported by future Intel CPUs.
1503
1504	  A kernel with the option enabled can be booted on machines that
1505	  support 4- or 5-level paging.
1506
1507	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1508	  information.
1509
1510	  Say N if unsure.
1511
1512config X86_DIRECT_GBPAGES
1513	def_bool y
1514	depends on X86_64
1515	help
1516	  Certain kernel features effectively disable kernel
1517	  linear 1 GB mappings (even if the CPU otherwise
1518	  supports them), so don't confuse the user by printing
1519	  that we have them enabled.
1520
1521config X86_CPA_STATISTICS
1522	bool "Enable statistic for Change Page Attribute"
1523	depends on DEBUG_FS
1524	help
1525	  Expose statistics about the Change Page Attribute mechanism, which
1526	  helps to determine the effectiveness of preserving large and huge
1527	  page mappings when mapping protections are changed.
1528
1529config X86_MEM_ENCRYPT
1530	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1531	select DYNAMIC_PHYSICAL_MASK
1532	def_bool n
1533
1534config AMD_MEM_ENCRYPT
1535	bool "AMD Secure Memory Encryption (SME) support"
1536	depends on X86_64 && CPU_SUP_AMD
1537	depends on EFI_STUB
1538	select DMA_COHERENT_POOL
1539	select ARCH_USE_MEMREMAP_PROT
1540	select INSTRUCTION_DECODER
1541	select ARCH_HAS_CC_PLATFORM
1542	select X86_MEM_ENCRYPT
1543	select UNACCEPTED_MEMORY
1544	help
1545	  Say yes to enable support for the encryption of system memory.
1546	  This requires an AMD processor that supports Secure Memory
1547	  Encryption (SME).
1548
1549# Common NUMA Features
1550config NUMA
1551	bool "NUMA Memory Allocation and Scheduler Support"
1552	depends on SMP
1553	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1554	default y if X86_BIGSMP
1555	select USE_PERCPU_NUMA_NODE_ID
1556	select OF_NUMA if OF
1557	help
1558	  Enable NUMA (Non-Uniform Memory Access) support.
1559
1560	  The kernel will try to allocate memory used by a CPU on the
1561	  local memory controller of the CPU and add some more
1562	  NUMA awareness to the kernel.
1563
1564	  For 64-bit this is recommended if the system is Intel Core i7
1565	  (or later), AMD Opteron, or EM64T NUMA.
1566
1567	  For 32-bit this is only needed if you boot a 32-bit
1568	  kernel on a 64-bit NUMA platform.
1569
1570	  Otherwise, you should say N.
1571
1572config AMD_NUMA
1573	def_bool y
1574	prompt "Old style AMD Opteron NUMA detection"
1575	depends on X86_64 && NUMA && PCI
1576	help
1577	  Enable AMD NUMA node topology detection.  You should say Y here if
1578	  you have a multi processor AMD system. This uses an old method to
1579	  read the NUMA configuration directly from the builtin Northbridge
1580	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1581	  which also takes priority if both are compiled in.
1582
1583config X86_64_ACPI_NUMA
1584	def_bool y
1585	prompt "ACPI NUMA detection"
1586	depends on X86_64 && NUMA && ACPI && PCI
1587	select ACPI_NUMA
1588	help
1589	  Enable ACPI SRAT based node topology detection.
1590
1591config NUMA_EMU
1592	bool "NUMA emulation"
1593	depends on NUMA
1594	help
1595	  Enable NUMA emulation. A flat machine will be split
1596	  into virtual nodes when booted with "numa=fake=N", where N is the
1597	  number of nodes. This is only useful for debugging.
1598
1599config NODES_SHIFT
1600	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1601	range 1 10
1602	default "10" if MAXSMP
1603	default "6" if X86_64
1604	default "3"
1605	depends on NUMA
1606	help
1607	  Specify the maximum number of NUMA Nodes available on the target
1608	  system.  Increases memory reserved to accommodate various tables.
1609
1610config ARCH_FLATMEM_ENABLE
1611	def_bool y
1612	depends on X86_32 && !NUMA
1613
1614config ARCH_SPARSEMEM_ENABLE
1615	def_bool y
1616	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1617	select SPARSEMEM_STATIC if X86_32
1618	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1619
1620config ARCH_SPARSEMEM_DEFAULT
1621	def_bool X86_64 || (NUMA && X86_32)
1622
1623config ARCH_SELECT_MEMORY_MODEL
1624	def_bool y
1625	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1626
1627config ARCH_MEMORY_PROBE
1628	bool "Enable sysfs memory/probe interface"
1629	depends on MEMORY_HOTPLUG
1630	help
1631	  This option enables a sysfs memory/probe interface for testing.
1632	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1633	  If you are unsure how to answer this question, answer N.
1634
1635config ARCH_PROC_KCORE_TEXT
1636	def_bool y
1637	depends on X86_64 && PROC_KCORE
1638
1639config ILLEGAL_POINTER_VALUE
1640	hex
1641	default 0 if X86_32
1642	default 0xdead000000000000 if X86_64
1643
1644config X86_PMEM_LEGACY_DEVICE
1645	bool
1646
1647config X86_PMEM_LEGACY
1648	tristate "Support non-standard NVDIMMs and ADR protected memory"
1649	depends on PHYS_ADDR_T_64BIT
1650	depends on BLK_DEV
1651	select X86_PMEM_LEGACY_DEVICE
1652	select NUMA_KEEP_MEMINFO if NUMA
1653	select LIBNVDIMM
1654	help
1655	  Treat memory marked using the non-standard e820 type of 12 as used
1656	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1657	  The kernel will offer these regions to the 'pmem' driver so
1658	  they can be used for persistent storage.
1659
1660	  Say Y if unsure.
1661
1662config HIGHPTE
1663	bool "Allocate 3rd-level pagetables from highmem"
1664	depends on HIGHMEM
1665	help
1666	  The VM uses one page table entry for each page of physical memory.
1667	  For systems with a lot of RAM, this can be wasteful of precious
1668	  low memory.  Setting this option will put user-space page table
1669	  entries in high memory.
1670
1671config X86_CHECK_BIOS_CORRUPTION
1672	bool "Check for low memory corruption"
1673	help
1674	  Periodically check for memory corruption in low memory, which
1675	  is suspected to be caused by BIOS.  Even when enabled in the
1676	  configuration, it is disabled at runtime.  Enable it by
1677	  setting "memory_corruption_check=1" on the kernel command
1678	  line.  By default it scans the low 64k of memory every 60
1679	  seconds; see the memory_corruption_check_size and
1680	  memory_corruption_check_period parameters in
1681	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1682
1683	  When enabled with the default parameters, this option has
1684	  almost no overhead, as it reserves a relatively small amount
1685	  of memory and scans it infrequently.  It both detects corruption
1686	  and prevents it from affecting the running system.
1687
1688	  It is, however, intended as a diagnostic tool; if repeatable
1689	  BIOS-originated corruption always affects the same memory,
1690	  you can use memmap= to prevent the kernel from using that
1691	  memory.
1692
1693config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1694	bool "Set the default setting of memory_corruption_check"
1695	depends on X86_CHECK_BIOS_CORRUPTION
1696	default y
1697	help
1698	  Set whether the default state of memory_corruption_check is
1699	  on or off.
1700
1701config MATH_EMULATION
1702	bool
1703	depends on MODIFY_LDT_SYSCALL
1704	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1705	help
1706	  Linux can emulate a math coprocessor (used for floating point
1707	  operations) if you don't have one. 486DX and Pentium processors have
1708	  a math coprocessor built in, 486SX and 386 do not, unless you added
1709	  a 487DX or 387, respectively. (The messages during boot time can
1710	  give you some hints here ["man dmesg"].) Everyone needs either a
1711	  coprocessor or this emulation.
1712
1713	  If you don't have a math coprocessor, you need to say Y here; if you
1714	  say Y here even though you have a coprocessor, the coprocessor will
1715	  be used nevertheless. (This behavior can be changed with the kernel
1716	  command line option "no387", which comes handy if your coprocessor
1717	  is broken. Try "man bootparam" or see the documentation of your boot
1718	  loader (lilo or loadlin) about how to pass options to the kernel at
1719	  boot time.) This means that it is a good idea to say Y here if you
1720	  intend to use this kernel on different machines.
1721
1722	  More information about the internals of the Linux math coprocessor
1723	  emulation can be found in <file:arch/x86/math-emu/README>.
1724
1725	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1726	  kernel, it won't hurt.
1727
1728config MTRR
1729	def_bool y
1730	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1731	help
1732	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1733	  the Memory Type Range Registers (MTRRs) may be used to control
1734	  processor access to memory ranges. This is most useful if you have
1735	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1736	  allows bus write transfers to be combined into a larger transfer
1737	  before bursting over the PCI/AGP bus. This can increase performance
1738	  of image write operations 2.5 times or more. Saying Y here creates a
1739	  /proc/mtrr file which may be used to manipulate your processor's
1740	  MTRRs. Typically the X server should use this.
1741
1742	  This code has a reasonably generic interface so that similar
1743	  control registers on other processors can be easily supported
1744	  as well:
1745
1746	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1747	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1748	  these, the ARRs are used to emulate the MTRRs.
1749	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1750	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1751	  write-combining. All of these processors are supported by this code
1752	  and it makes sense to say Y here if you have one of them.
1753
1754	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1755	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1756	  can lead to all sorts of problems, so it's good to say Y here.
1757
1758	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1759	  just add about 9 KB to your kernel.
1760
1761	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1762
1763config MTRR_SANITIZER
1764	def_bool y
1765	prompt "MTRR cleanup support"
1766	depends on MTRR
1767	help
1768	  Convert MTRR layout from continuous to discrete, so X drivers can
1769	  add writeback entries.
1770
1771	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1772	  The largest mtrr entry size for a continuous block can be set with
1773	  mtrr_chunk_size.
1774
1775	  If unsure, say Y.
1776
1777config MTRR_SANITIZER_ENABLE_DEFAULT
1778	int "MTRR cleanup enable value (0-1)"
1779	range 0 1
1780	default "0"
1781	depends on MTRR_SANITIZER
1782	help
1783	  Enable mtrr cleanup default value
1784
1785config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1786	int "MTRR cleanup spare reg num (0-7)"
1787	range 0 7
1788	default "1"
1789	depends on MTRR_SANITIZER
1790	help
1791	  mtrr cleanup spare entries default, it can be changed via
1792	  mtrr_spare_reg_nr=N on the kernel command line.
1793
1794config X86_PAT
1795	def_bool y
1796	prompt "x86 PAT support" if EXPERT
1797	depends on MTRR
1798	help
1799	  Use PAT attributes to setup page level cache control.
1800
1801	  PATs are the modern equivalents of MTRRs and are much more
1802	  flexible than MTRRs.
1803
1804	  Say N here if you see bootup problems (boot crash, boot hang,
1805	  spontaneous reboots) or a non-working video driver.
1806
1807	  If unsure, say Y.
1808
1809config ARCH_USES_PG_UNCACHED
1810	def_bool y
1811	depends on X86_PAT
1812
1813config X86_UMIP
1814	def_bool y
1815	prompt "User Mode Instruction Prevention" if EXPERT
1816	help
1817	  User Mode Instruction Prevention (UMIP) is a security feature in
1818	  some x86 processors. If enabled, a general protection fault is
1819	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1820	  executed in user mode. These instructions unnecessarily expose
1821	  information about the hardware state.
1822
1823	  The vast majority of applications do not use these instructions.
1824	  For the very few that do, software emulation is provided in
1825	  specific cases in protected and virtual-8086 modes. Emulated
1826	  results are dummy.
1827
1828config CC_HAS_IBT
1829	# GCC >= 9 and binutils >= 2.29
1830	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1831	# Clang/LLVM >= 14
1832	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1833	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1834	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1835		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1836		  $(as-instr,endbr64)
1837
1838config X86_CET
1839	def_bool n
1840	help
1841	  CET features configured (Shadow stack or IBT)
1842
1843config X86_KERNEL_IBT
1844	prompt "Indirect Branch Tracking"
1845	def_bool y
1846	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1847	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1848	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1849	select OBJTOOL
1850	select X86_CET
1851	help
1852	  Build the kernel with support for Indirect Branch Tracking, a
1853	  hardware support course-grain forward-edge Control Flow Integrity
1854	  protection. It enforces that all indirect calls must land on
1855	  an ENDBR instruction, as such, the compiler will instrument the
1856	  code with them to make this happen.
1857
1858	  In addition to building the kernel with IBT, seal all functions that
1859	  are not indirect call targets, avoiding them ever becoming one.
1860
1861	  This requires LTO like objtool runs and will slow down the build. It
1862	  does significantly reduce the number of ENDBR instructions in the
1863	  kernel image.
1864
1865config X86_INTEL_MEMORY_PROTECTION_KEYS
1866	prompt "Memory Protection Keys"
1867	def_bool y
1868	# Note: only available in 64-bit mode
1869	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1870	select ARCH_USES_HIGH_VMA_FLAGS
1871	select ARCH_HAS_PKEYS
1872	help
1873	  Memory Protection Keys provides a mechanism for enforcing
1874	  page-based protections, but without requiring modification of the
1875	  page tables when an application changes protection domains.
1876
1877	  For details, see Documentation/core-api/protection-keys.rst
1878
1879	  If unsure, say y.
1880
1881choice
1882	prompt "TSX enable mode"
1883	depends on CPU_SUP_INTEL
1884	default X86_INTEL_TSX_MODE_OFF
1885	help
1886	  Intel's TSX (Transactional Synchronization Extensions) feature
1887	  allows to optimize locking protocols through lock elision which
1888	  can lead to a noticeable performance boost.
1889
1890	  On the other hand it has been shown that TSX can be exploited
1891	  to form side channel attacks (e.g. TAA) and chances are there
1892	  will be more of those attacks discovered in the future.
1893
1894	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1895	  might override this decision by tsx=on the command line parameter.
1896	  Even with TSX enabled, the kernel will attempt to enable the best
1897	  possible TAA mitigation setting depending on the microcode available
1898	  for the particular machine.
1899
1900	  This option allows to set the default tsx mode between tsx=on, =off
1901	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1902	  details.
1903
1904	  Say off if not sure, auto if TSX is in use but it should be used on safe
1905	  platforms or on if TSX is in use and the security aspect of tsx is not
1906	  relevant.
1907
1908config X86_INTEL_TSX_MODE_OFF
1909	bool "off"
1910	help
1911	  TSX is disabled if possible - equals to tsx=off command line parameter.
1912
1913config X86_INTEL_TSX_MODE_ON
1914	bool "on"
1915	help
1916	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1917	  line parameter.
1918
1919config X86_INTEL_TSX_MODE_AUTO
1920	bool "auto"
1921	help
1922	  TSX is enabled on TSX capable HW that is believed to be safe against
1923	  side channel attacks- equals the tsx=auto command line parameter.
1924endchoice
1925
1926config X86_SGX
1927	bool "Software Guard eXtensions (SGX)"
1928	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1929	depends on CRYPTO=y
1930	depends on CRYPTO_SHA256=y
1931	select MMU_NOTIFIER
1932	select NUMA_KEEP_MEMINFO if NUMA
1933	select XARRAY_MULTI
1934	help
1935	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1936	  that can be used by applications to set aside private regions of code
1937	  and data, referred to as enclaves. An enclave's private memory can
1938	  only be accessed by code running within the enclave. Accesses from
1939	  outside the enclave, including other enclaves, are disallowed by
1940	  hardware.
1941
1942	  If unsure, say N.
1943
1944config X86_USER_SHADOW_STACK
1945	bool "X86 userspace shadow stack"
1946	depends on AS_WRUSS
1947	depends on X86_64
1948	select ARCH_USES_HIGH_VMA_FLAGS
1949	select X86_CET
1950	help
1951	  Shadow stack protection is a hardware feature that detects function
1952	  return address corruption.  This helps mitigate ROP attacks.
1953	  Applications must be enabled to use it, and old userspace does not
1954	  get protection "for free".
1955
1956	  CPUs supporting shadow stacks were first released in 2020.
1957
1958	  See Documentation/arch/x86/shstk.rst for more information.
1959
1960	  If unsure, say N.
1961
1962config INTEL_TDX_HOST
1963	bool "Intel Trust Domain Extensions (TDX) host support"
1964	depends on CPU_SUP_INTEL
1965	depends on X86_64
1966	depends on KVM_INTEL
1967	depends on X86_X2APIC
1968	select ARCH_KEEP_MEMBLOCK
1969	depends on CONTIG_ALLOC
1970	depends on !KEXEC_CORE
1971	depends on X86_MCE
1972	help
1973	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
1974	  host and certain physical attacks.  This option enables necessary TDX
1975	  support in the host kernel to run confidential VMs.
1976
1977	  If unsure, say N.
1978
1979config EFI
1980	bool "EFI runtime service support"
1981	depends on ACPI
1982	select UCS2_STRING
1983	select EFI_RUNTIME_WRAPPERS
1984	select ARCH_USE_MEMREMAP_PROT
1985	select EFI_RUNTIME_MAP if KEXEC_CORE
1986	help
1987	  This enables the kernel to use EFI runtime services that are
1988	  available (such as the EFI variable services).
1989
1990	  This option is only useful on systems that have EFI firmware.
1991	  In addition, you should use the latest ELILO loader available
1992	  at <http://elilo.sourceforge.net> in order to take advantage
1993	  of EFI runtime services. However, even with this option, the
1994	  resultant kernel should continue to boot on existing non-EFI
1995	  platforms.
1996
1997config EFI_STUB
1998	bool "EFI stub support"
1999	depends on EFI
2000	select RELOCATABLE
2001	help
2002	  This kernel feature allows a bzImage to be loaded directly
2003	  by EFI firmware without the use of a bootloader.
2004
2005	  See Documentation/admin-guide/efi-stub.rst for more information.
2006
2007config EFI_HANDOVER_PROTOCOL
2008	bool "EFI handover protocol (DEPRECATED)"
2009	depends on EFI_STUB
2010	default y
2011	help
2012	  Select this in order to include support for the deprecated EFI
2013	  handover protocol, which defines alternative entry points into the
2014	  EFI stub.  This is a practice that has no basis in the UEFI
2015	  specification, and requires a priori knowledge on the part of the
2016	  bootloader about Linux/x86 specific ways of passing the command line
2017	  and initrd, and where in memory those assets may be loaded.
2018
2019	  If in doubt, say Y. Even though the corresponding support is not
2020	  present in upstream GRUB or other bootloaders, most distros build
2021	  GRUB with numerous downstream patches applied, and may rely on the
2022	  handover protocol as as result.
2023
2024config EFI_MIXED
2025	bool "EFI mixed-mode support"
2026	depends on EFI_STUB && X86_64
2027	help
2028	  Enabling this feature allows a 64-bit kernel to be booted
2029	  on a 32-bit firmware, provided that your CPU supports 64-bit
2030	  mode.
2031
2032	  Note that it is not possible to boot a mixed-mode enabled
2033	  kernel via the EFI boot stub - a bootloader that supports
2034	  the EFI handover protocol must be used.
2035
2036	  If unsure, say N.
2037
2038config EFI_FAKE_MEMMAP
2039	bool "Enable EFI fake memory map"
2040	depends on EFI
2041	help
2042	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2043	  this parameter, you can add arbitrary attribute to specific memory
2044	  range by updating original (firmware provided) EFI memmap.  This is
2045	  useful for debugging of EFI memmap related feature, e.g., Address
2046	  Range Mirroring feature.
2047
2048config EFI_MAX_FAKE_MEM
2049	int "maximum allowable number of ranges in efi_fake_mem boot option"
2050	depends on EFI_FAKE_MEMMAP
2051	range 1 128
2052	default 8
2053	help
2054	  Maximum allowable number of ranges in efi_fake_mem boot option.
2055	  Ranges can be set up to this value using comma-separated list.
2056	  The default value is 8.
2057
2058config EFI_RUNTIME_MAP
2059	bool "Export EFI runtime maps to sysfs" if EXPERT
2060	depends on EFI
2061	help
2062	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2063	  That memory map is required by the 2nd kernel to set up EFI virtual
2064	  mappings after kexec, but can also be used for debugging purposes.
2065
2066	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2067
2068source "kernel/Kconfig.hz"
2069
2070config ARCH_SUPPORTS_KEXEC
2071	def_bool y
2072
2073config ARCH_SUPPORTS_KEXEC_FILE
2074	def_bool X86_64
2075
2076config ARCH_SELECTS_KEXEC_FILE
2077	def_bool y
2078	depends on KEXEC_FILE
2079	select HAVE_IMA_KEXEC if IMA
2080
2081config ARCH_SUPPORTS_KEXEC_PURGATORY
2082	def_bool y
2083
2084config ARCH_SUPPORTS_KEXEC_SIG
2085	def_bool y
2086
2087config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2088	def_bool y
2089
2090config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2091	def_bool y
2092
2093config ARCH_SUPPORTS_KEXEC_JUMP
2094	def_bool y
2095
2096config ARCH_SUPPORTS_CRASH_DUMP
2097	def_bool X86_64 || (X86_32 && HIGHMEM)
2098
2099config ARCH_SUPPORTS_CRASH_HOTPLUG
2100	def_bool y
2101
2102config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
2103	def_bool CRASH_RESERVE
2104
2105config PHYSICAL_START
2106	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2107	default "0x1000000"
2108	help
2109	  This gives the physical address where the kernel is loaded.
2110
2111	  If the kernel is not relocatable (CONFIG_RELOCATABLE=n) then bzImage
2112	  will decompress itself to above physical address and run from there.
2113	  Otherwise, bzImage will run from the address where it has been loaded
2114	  by the boot loader. The only exception is if it is loaded below the
2115	  above physical address, in which case it will relocate itself there.
2116
2117	  In normal kdump cases one does not have to set/change this option
2118	  as now bzImage can be compiled as a completely relocatable image
2119	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2120	  address. This option is mainly useful for the folks who don't want
2121	  to use a bzImage for capturing the crash dump and want to use a
2122	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2123	  to be specifically compiled to run from a specific memory area
2124	  (normally a reserved region) and this option comes handy.
2125
2126	  So if you are using bzImage for capturing the crash dump,
2127	  leave the value here unchanged to 0x1000000 and set
2128	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2129	  for capturing the crash dump change this value to start of
2130	  the reserved region.  In other words, it can be set based on
2131	  the "X" value as specified in the "crashkernel=YM@XM"
2132	  command line boot parameter passed to the panic-ed
2133	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2134	  for more details about crash dumps.
2135
2136	  Usage of bzImage for capturing the crash dump is recommended as
2137	  one does not have to build two kernels. Same kernel can be used
2138	  as production kernel and capture kernel. Above option should have
2139	  gone away after relocatable bzImage support is introduced. But it
2140	  is present because there are users out there who continue to use
2141	  vmlinux for dump capture. This option should go away down the
2142	  line.
2143
2144	  Don't change this unless you know what you are doing.
2145
2146config RELOCATABLE
2147	bool "Build a relocatable kernel"
2148	default y
2149	help
2150	  This builds a kernel image that retains relocation information
2151	  so it can be loaded someplace besides the default 1MB.
2152	  The relocations tend to make the kernel binary about 10% larger,
2153	  but are discarded at runtime.
2154
2155	  One use is for the kexec on panic case where the recovery kernel
2156	  must live at a different physical address than the primary
2157	  kernel.
2158
2159	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2160	  it has been loaded at and the compile time physical address
2161	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2162
2163config RANDOMIZE_BASE
2164	bool "Randomize the address of the kernel image (KASLR)"
2165	depends on RELOCATABLE
2166	default y
2167	help
2168	  In support of Kernel Address Space Layout Randomization (KASLR),
2169	  this randomizes the physical address at which the kernel image
2170	  is decompressed and the virtual address where the kernel
2171	  image is mapped, as a security feature that deters exploit
2172	  attempts relying on knowledge of the location of kernel
2173	  code internals.
2174
2175	  On 64-bit, the kernel physical and virtual addresses are
2176	  randomized separately. The physical address will be anywhere
2177	  between 16MB and the top of physical memory (up to 64TB). The
2178	  virtual address will be randomized from 16MB up to 1GB (9 bits
2179	  of entropy). Note that this also reduces the memory space
2180	  available to kernel modules from 1.5GB to 1GB.
2181
2182	  On 32-bit, the kernel physical and virtual addresses are
2183	  randomized together. They will be randomized from 16MB up to
2184	  512MB (8 bits of entropy).
2185
2186	  Entropy is generated using the RDRAND instruction if it is
2187	  supported. If RDTSC is supported, its value is mixed into
2188	  the entropy pool as well. If neither RDRAND nor RDTSC are
2189	  supported, then entropy is read from the i8254 timer. The
2190	  usable entropy is limited by the kernel being built using
2191	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2192	  minimum of 2MB. As a result, only 10 bits of entropy are
2193	  theoretically possible, but the implementations are further
2194	  limited due to memory layouts.
2195
2196	  If unsure, say Y.
2197
2198# Relocation on x86 needs some additional build support
2199config X86_NEED_RELOCS
2200	def_bool y
2201	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2202
2203config PHYSICAL_ALIGN
2204	hex "Alignment value to which kernel should be aligned"
2205	default "0x200000"
2206	range 0x2000 0x1000000 if X86_32
2207	range 0x200000 0x1000000 if X86_64
2208	help
2209	  This value puts the alignment restrictions on physical address
2210	  where kernel is loaded and run from. Kernel is compiled for an
2211	  address which meets above alignment restriction.
2212
2213	  If bootloader loads the kernel at a non-aligned address and
2214	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2215	  address aligned to above value and run from there.
2216
2217	  If bootloader loads the kernel at a non-aligned address and
2218	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2219	  load address and decompress itself to the address it has been
2220	  compiled for and run from there. The address for which kernel is
2221	  compiled already meets above alignment restrictions. Hence the
2222	  end result is that kernel runs from a physical address meeting
2223	  above alignment restrictions.
2224
2225	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2226	  this value must be a multiple of 0x200000.
2227
2228	  Don't change this unless you know what you are doing.
2229
2230config DYNAMIC_MEMORY_LAYOUT
2231	bool
2232	help
2233	  This option makes base addresses of vmalloc and vmemmap as well as
2234	  __PAGE_OFFSET movable during boot.
2235
2236config RANDOMIZE_MEMORY
2237	bool "Randomize the kernel memory sections"
2238	depends on X86_64
2239	depends on RANDOMIZE_BASE
2240	select DYNAMIC_MEMORY_LAYOUT
2241	default RANDOMIZE_BASE
2242	help
2243	  Randomizes the base virtual address of kernel memory sections
2244	  (physical memory mapping, vmalloc & vmemmap). This security feature
2245	  makes exploits relying on predictable memory locations less reliable.
2246
2247	  The order of allocations remains unchanged. Entropy is generated in
2248	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2249	  configuration have in average 30,000 different possible virtual
2250	  addresses for each memory section.
2251
2252	  If unsure, say Y.
2253
2254config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2255	hex "Physical memory mapping padding" if EXPERT
2256	depends on RANDOMIZE_MEMORY
2257	default "0xa" if MEMORY_HOTPLUG
2258	default "0x0"
2259	range 0x1 0x40 if MEMORY_HOTPLUG
2260	range 0x0 0x40
2261	help
2262	  Define the padding in terabytes added to the existing physical
2263	  memory size during kernel memory randomization. It is useful
2264	  for memory hotplug support but reduces the entropy available for
2265	  address randomization.
2266
2267	  If unsure, leave at the default value.
2268
2269config ADDRESS_MASKING
2270	bool "Linear Address Masking support"
2271	depends on X86_64
2272	help
2273	  Linear Address Masking (LAM) modifies the checking that is applied
2274	  to 64-bit linear addresses, allowing software to use of the
2275	  untranslated address bits for metadata.
2276
2277	  The capability can be used for efficient address sanitizers (ASAN)
2278	  implementation and for optimizations in JITs.
2279
2280config HOTPLUG_CPU
2281	def_bool y
2282	depends on SMP
2283
2284config COMPAT_VDSO
2285	def_bool n
2286	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2287	depends on COMPAT_32
2288	help
2289	  Certain buggy versions of glibc will crash if they are
2290	  presented with a 32-bit vDSO that is not mapped at the address
2291	  indicated in its segment table.
2292
2293	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2294	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2295	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2296	  the only released version with the bug, but OpenSUSE 9
2297	  contains a buggy "glibc 2.3.2".
2298
2299	  The symptom of the bug is that everything crashes on startup, saying:
2300	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2301
2302	  Saying Y here changes the default value of the vdso32 boot
2303	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2304	  This works around the glibc bug but hurts performance.
2305
2306	  If unsure, say N: if you are compiling your own kernel, you
2307	  are unlikely to be using a buggy version of glibc.
2308
2309choice
2310	prompt "vsyscall table for legacy applications"
2311	depends on X86_64
2312	default LEGACY_VSYSCALL_XONLY
2313	help
2314	  Legacy user code that does not know how to find the vDSO expects
2315	  to be able to issue three syscalls by calling fixed addresses in
2316	  kernel space. Since this location is not randomized with ASLR,
2317	  it can be used to assist security vulnerability exploitation.
2318
2319	  This setting can be changed at boot time via the kernel command
2320	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2321	  is deprecated and can only be enabled using the kernel command
2322	  line.
2323
2324	  On a system with recent enough glibc (2.14 or newer) and no
2325	  static binaries, you can say None without a performance penalty
2326	  to improve security.
2327
2328	  If unsure, select "Emulate execution only".
2329
2330	config LEGACY_VSYSCALL_XONLY
2331		bool "Emulate execution only"
2332		help
2333		  The kernel traps and emulates calls into the fixed vsyscall
2334		  address mapping and does not allow reads.  This
2335		  configuration is recommended when userspace might use the
2336		  legacy vsyscall area but support for legacy binary
2337		  instrumentation of legacy code is not needed.  It mitigates
2338		  certain uses of the vsyscall area as an ASLR-bypassing
2339		  buffer.
2340
2341	config LEGACY_VSYSCALL_NONE
2342		bool "None"
2343		help
2344		  There will be no vsyscall mapping at all. This will
2345		  eliminate any risk of ASLR bypass due to the vsyscall
2346		  fixed address mapping. Attempts to use the vsyscalls
2347		  will be reported to dmesg, so that either old or
2348		  malicious userspace programs can be identified.
2349
2350endchoice
2351
2352config CMDLINE_BOOL
2353	bool "Built-in kernel command line"
2354	help
2355	  Allow for specifying boot arguments to the kernel at
2356	  build time.  On some systems (e.g. embedded ones), it is
2357	  necessary or convenient to provide some or all of the
2358	  kernel boot arguments with the kernel itself (that is,
2359	  to not rely on the boot loader to provide them.)
2360
2361	  To compile command line arguments into the kernel,
2362	  set this option to 'Y', then fill in the
2363	  boot arguments in CONFIG_CMDLINE.
2364
2365	  Systems with fully functional boot loaders (i.e. non-embedded)
2366	  should leave this option set to 'N'.
2367
2368config CMDLINE
2369	string "Built-in kernel command string"
2370	depends on CMDLINE_BOOL
2371	default ""
2372	help
2373	  Enter arguments here that should be compiled into the kernel
2374	  image and used at boot time.  If the boot loader provides a
2375	  command line at boot time, it is appended to this string to
2376	  form the full kernel command line, when the system boots.
2377
2378	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2379	  change this behavior.
2380
2381	  In most cases, the command line (whether built-in or provided
2382	  by the boot loader) should specify the device for the root
2383	  file system.
2384
2385config CMDLINE_OVERRIDE
2386	bool "Built-in command line overrides boot loader arguments"
2387	depends on CMDLINE_BOOL && CMDLINE != ""
2388	help
2389	  Set this option to 'Y' to have the kernel ignore the boot loader
2390	  command line, and use ONLY the built-in command line.
2391
2392	  This is used to work around broken boot loaders.  This should
2393	  be set to 'N' under normal conditions.
2394
2395config MODIFY_LDT_SYSCALL
2396	bool "Enable the LDT (local descriptor table)" if EXPERT
2397	default y
2398	help
2399	  Linux can allow user programs to install a per-process x86
2400	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2401	  call.  This is required to run 16-bit or segmented code such as
2402	  DOSEMU or some Wine programs.  It is also used by some very old
2403	  threading libraries.
2404
2405	  Enabling this feature adds a small amount of overhead to
2406	  context switches and increases the low-level kernel attack
2407	  surface.  Disabling it removes the modify_ldt(2) system call.
2408
2409	  Saying 'N' here may make sense for embedded or server kernels.
2410
2411config STRICT_SIGALTSTACK_SIZE
2412	bool "Enforce strict size checking for sigaltstack"
2413	depends on DYNAMIC_SIGFRAME
2414	help
2415	  For historical reasons MINSIGSTKSZ is a constant which became
2416	  already too small with AVX512 support. Add a mechanism to
2417	  enforce strict checking of the sigaltstack size against the
2418	  real size of the FPU frame. This option enables the check
2419	  by default. It can also be controlled via the kernel command
2420	  line option 'strict_sas_size' independent of this config
2421	  switch. Enabling it might break existing applications which
2422	  allocate a too small sigaltstack but 'work' because they
2423	  never get a signal delivered.
2424
2425	  Say 'N' unless you want to really enforce this check.
2426
2427source "kernel/livepatch/Kconfig"
2428
2429endmenu
2430
2431config CC_HAS_NAMED_AS
2432	def_bool CC_IS_GCC && GCC_VERSION >= 120100
2433
2434config USE_X86_SEG_SUPPORT
2435	def_bool y
2436	depends on CC_HAS_NAMED_AS
2437	#
2438	# -fsanitize=kernel-address (KASAN) is at the moment incompatible
2439	# with named address spaces - see GCC PR sanitizer/111736.
2440	#
2441	depends on !KASAN
2442	# -fsanitize=thread (KCSAN) is also incompatible.
2443	depends on !KCSAN
2444
2445config CC_HAS_SLS
2446	def_bool $(cc-option,-mharden-sls=all)
2447
2448config CC_HAS_RETURN_THUNK
2449	def_bool $(cc-option,-mfunction-return=thunk-extern)
2450
2451config CC_HAS_ENTRY_PADDING
2452	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2453
2454config FUNCTION_PADDING_CFI
2455	int
2456	default 59 if FUNCTION_ALIGNMENT_64B
2457	default 27 if FUNCTION_ALIGNMENT_32B
2458	default 11 if FUNCTION_ALIGNMENT_16B
2459	default  3 if FUNCTION_ALIGNMENT_8B
2460	default  0
2461
2462# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2463# except Kconfig can't do arithmetic :/
2464config FUNCTION_PADDING_BYTES
2465	int
2466	default FUNCTION_PADDING_CFI if CFI_CLANG
2467	default FUNCTION_ALIGNMENT
2468
2469config CALL_PADDING
2470	def_bool n
2471	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2472	select FUNCTION_ALIGNMENT_16B
2473
2474config FINEIBT
2475	def_bool y
2476	depends on X86_KERNEL_IBT && CFI_CLANG && MITIGATION_RETPOLINE
2477	select CALL_PADDING
2478
2479config HAVE_CALL_THUNKS
2480	def_bool y
2481	depends on CC_HAS_ENTRY_PADDING && MITIGATION_RETHUNK && OBJTOOL
2482
2483config CALL_THUNKS
2484	def_bool n
2485	select CALL_PADDING
2486
2487config PREFIX_SYMBOLS
2488	def_bool y
2489	depends on CALL_PADDING && !CFI_CLANG
2490
2491menuconfig SPECULATION_MITIGATIONS
2492	bool "Mitigations for speculative execution vulnerabilities"
2493	default y
2494	help
2495	  Say Y here to enable options which enable mitigations for
2496	  speculative execution hardware vulnerabilities.
2497
2498	  If you say N, all mitigations will be disabled. You really
2499	  should know what you are doing to say so.
2500
2501if SPECULATION_MITIGATIONS
2502
2503config MITIGATION_PAGE_TABLE_ISOLATION
2504	bool "Remove the kernel mapping in user mode"
2505	default y
2506	depends on (X86_64 || X86_PAE)
2507	help
2508	  This feature reduces the number of hardware side channels by
2509	  ensuring that the majority of kernel addresses are not mapped
2510	  into userspace.
2511
2512	  See Documentation/arch/x86/pti.rst for more details.
2513
2514config MITIGATION_RETPOLINE
2515	bool "Avoid speculative indirect branches in kernel"
2516	select OBJTOOL if HAVE_OBJTOOL
2517	default y
2518	help
2519	  Compile kernel with the retpoline compiler options to guard against
2520	  kernel-to-user data leaks by avoiding speculative indirect
2521	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2522	  support for full protection. The kernel may run slower.
2523
2524config MITIGATION_RETHUNK
2525	bool "Enable return-thunks"
2526	depends on MITIGATION_RETPOLINE && CC_HAS_RETURN_THUNK
2527	select OBJTOOL if HAVE_OBJTOOL
2528	default y if X86_64
2529	help
2530	  Compile the kernel with the return-thunks compiler option to guard
2531	  against kernel-to-user data leaks by avoiding return speculation.
2532	  Requires a compiler with -mfunction-return=thunk-extern
2533	  support for full protection. The kernel may run slower.
2534
2535config MITIGATION_UNRET_ENTRY
2536	bool "Enable UNRET on kernel entry"
2537	depends on CPU_SUP_AMD && MITIGATION_RETHUNK && X86_64
2538	default y
2539	help
2540	  Compile the kernel with support for the retbleed=unret mitigation.
2541
2542config MITIGATION_CALL_DEPTH_TRACKING
2543	bool "Mitigate RSB underflow with call depth tracking"
2544	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2545	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2546	select CALL_THUNKS
2547	default y
2548	help
2549	  Compile the kernel with call depth tracking to mitigate the Intel
2550	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2551	  mitigation is off by default and needs to be enabled on the
2552	  kernel command line via the retbleed=stuff option. For
2553	  non-affected systems the overhead of this option is marginal as
2554	  the call depth tracking is using run-time generated call thunks
2555	  in a compiler generated padding area and call patching. This
2556	  increases text size by ~5%. For non affected systems this space
2557	  is unused. On affected SKL systems this results in a significant
2558	  performance gain over the IBRS mitigation.
2559
2560config CALL_THUNKS_DEBUG
2561	bool "Enable call thunks and call depth tracking debugging"
2562	depends on MITIGATION_CALL_DEPTH_TRACKING
2563	select FUNCTION_ALIGNMENT_32B
2564	default n
2565	help
2566	  Enable call/ret counters for imbalance detection and build in
2567	  a noisy dmesg about callthunks generation and call patching for
2568	  trouble shooting. The debug prints need to be enabled on the
2569	  kernel command line with 'debug-callthunks'.
2570	  Only enable this when you are debugging call thunks as this
2571	  creates a noticeable runtime overhead. If unsure say N.
2572
2573config MITIGATION_IBPB_ENTRY
2574	bool "Enable IBPB on kernel entry"
2575	depends on CPU_SUP_AMD && X86_64
2576	default y
2577	help
2578	  Compile the kernel with support for the retbleed=ibpb mitigation.
2579
2580config MITIGATION_IBRS_ENTRY
2581	bool "Enable IBRS on kernel entry"
2582	depends on CPU_SUP_INTEL && X86_64
2583	default y
2584	help
2585	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2586	  This mitigates both spectre_v2 and retbleed at great cost to
2587	  performance.
2588
2589config MITIGATION_SRSO
2590	bool "Mitigate speculative RAS overflow on AMD"
2591	depends on CPU_SUP_AMD && X86_64 && MITIGATION_RETHUNK
2592	default y
2593	help
2594	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2595
2596config MITIGATION_SLS
2597	bool "Mitigate Straight-Line-Speculation"
2598	depends on CC_HAS_SLS && X86_64
2599	select OBJTOOL if HAVE_OBJTOOL
2600	default n
2601	help
2602	  Compile the kernel with straight-line-speculation options to guard
2603	  against straight line speculation. The kernel image might be slightly
2604	  larger.
2605
2606config MITIGATION_GDS_FORCE
2607	bool "Force GDS Mitigation"
2608	depends on CPU_SUP_INTEL
2609	default n
2610	help
2611	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2612	  unprivileged speculative access to data which was previously stored in
2613	  vector registers.
2614
2615	  This option is equivalent to setting gather_data_sampling=force on the
2616	  command line. The microcode mitigation is used if present, otherwise
2617	  AVX is disabled as a mitigation. On affected systems that are missing
2618	  the microcode any userspace code that unconditionally uses AVX will
2619	  break with this option set.
2620
2621	  Setting this option on systems not vulnerable to GDS has no effect.
2622
2623	  If in doubt, say N.
2624
2625config MITIGATION_RFDS
2626	bool "RFDS Mitigation"
2627	depends on CPU_SUP_INTEL
2628	default y
2629	help
2630	  Enable mitigation for Register File Data Sampling (RFDS) by default.
2631	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
2632	  allows unprivileged speculative access to stale data previously
2633	  stored in floating point, vector and integer registers.
2634	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
2635
2636config MITIGATION_SPECTRE_BHI
2637	bool "Mitigate Spectre-BHB (Branch History Injection)"
2638	depends on CPU_SUP_INTEL
2639	default y
2640	help
2641	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2642	  where the branch history buffer is poisoned to speculatively steer
2643	  indirect branches.
2644	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2645
2646endif
2647
2648config ARCH_HAS_ADD_PAGES
2649	def_bool y
2650	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2651
2652menu "Power management and ACPI options"
2653
2654config ARCH_HIBERNATION_HEADER
2655	def_bool y
2656	depends on HIBERNATION
2657
2658source "kernel/power/Kconfig"
2659
2660source "drivers/acpi/Kconfig"
2661
2662config X86_APM_BOOT
2663	def_bool y
2664	depends on APM
2665
2666menuconfig APM
2667	tristate "APM (Advanced Power Management) BIOS support"
2668	depends on X86_32 && PM_SLEEP
2669	help
2670	  APM is a BIOS specification for saving power using several different
2671	  techniques. This is mostly useful for battery powered laptops with
2672	  APM compliant BIOSes. If you say Y here, the system time will be
2673	  reset after a RESUME operation, the /proc/apm device will provide
2674	  battery status information, and user-space programs will receive
2675	  notification of APM "events" (e.g. battery status change).
2676
2677	  If you select "Y" here, you can disable actual use of the APM
2678	  BIOS by passing the "apm=off" option to the kernel at boot time.
2679
2680	  Note that the APM support is almost completely disabled for
2681	  machines with more than one CPU.
2682
2683	  In order to use APM, you will need supporting software. For location
2684	  and more information, read <file:Documentation/power/apm-acpi.rst>
2685	  and the Battery Powered Linux mini-HOWTO, available from
2686	  <http://www.tldp.org/docs.html#howto>.
2687
2688	  This driver does not spin down disk drives (see the hdparm(8)
2689	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2690	  VESA-compliant "green" monitors.
2691
2692	  This driver does not support the TI 4000M TravelMate and the ACER
2693	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2694	  desktop machines also don't have compliant BIOSes, and this driver
2695	  may cause those machines to panic during the boot phase.
2696
2697	  Generally, if you don't have a battery in your machine, there isn't
2698	  much point in using this driver and you should say N. If you get
2699	  random kernel OOPSes or reboots that don't seem to be related to
2700	  anything, try disabling/enabling this option (or disabling/enabling
2701	  APM in your BIOS).
2702
2703	  Some other things you should try when experiencing seemingly random,
2704	  "weird" problems:
2705
2706	  1) make sure that you have enough swap space and that it is
2707	  enabled.
2708	  2) pass the "idle=poll" option to the kernel
2709	  3) switch on floating point emulation in the kernel and pass
2710	  the "no387" option to the kernel
2711	  4) pass the "floppy=nodma" option to the kernel
2712	  5) pass the "mem=4M" option to the kernel (thereby disabling
2713	  all but the first 4 MB of RAM)
2714	  6) make sure that the CPU is not over clocked.
2715	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2716	  8) disable the cache from your BIOS settings
2717	  9) install a fan for the video card or exchange video RAM
2718	  10) install a better fan for the CPU
2719	  11) exchange RAM chips
2720	  12) exchange the motherboard.
2721
2722	  To compile this driver as a module, choose M here: the
2723	  module will be called apm.
2724
2725if APM
2726
2727config APM_IGNORE_USER_SUSPEND
2728	bool "Ignore USER SUSPEND"
2729	help
2730	  This option will ignore USER SUSPEND requests. On machines with a
2731	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2732	  series notebooks, it is necessary to say Y because of a BIOS bug.
2733
2734config APM_DO_ENABLE
2735	bool "Enable PM at boot time"
2736	help
2737	  Enable APM features at boot time. From page 36 of the APM BIOS
2738	  specification: "When disabled, the APM BIOS does not automatically
2739	  power manage devices, enter the Standby State, enter the Suspend
2740	  State, or take power saving steps in response to CPU Idle calls."
2741	  This driver will make CPU Idle calls when Linux is idle (unless this
2742	  feature is turned off -- see "Do CPU IDLE calls", below). This
2743	  should always save battery power, but more complicated APM features
2744	  will be dependent on your BIOS implementation. You may need to turn
2745	  this option off if your computer hangs at boot time when using APM
2746	  support, or if it beeps continuously instead of suspending. Turn
2747	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2748	  T400CDT. This is off by default since most machines do fine without
2749	  this feature.
2750
2751config APM_CPU_IDLE
2752	depends on CPU_IDLE
2753	bool "Make CPU Idle calls when idle"
2754	help
2755	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2756	  On some machines, this can activate improved power savings, such as
2757	  a slowed CPU clock rate, when the machine is idle. These idle calls
2758	  are made after the idle loop has run for some length of time (e.g.,
2759	  333 mS). On some machines, this will cause a hang at boot time or
2760	  whenever the CPU becomes idle. (On machines with more than one CPU,
2761	  this option does nothing.)
2762
2763config APM_DISPLAY_BLANK
2764	bool "Enable console blanking using APM"
2765	help
2766	  Enable console blanking using the APM. Some laptops can use this to
2767	  turn off the LCD backlight when the screen blanker of the Linux
2768	  virtual console blanks the screen. Note that this is only used by
2769	  the virtual console screen blanker, and won't turn off the backlight
2770	  when using the X Window system. This also doesn't have anything to
2771	  do with your VESA-compliant power-saving monitor. Further, this
2772	  option doesn't work for all laptops -- it might not turn off your
2773	  backlight at all, or it might print a lot of errors to the console,
2774	  especially if you are using gpm.
2775
2776config APM_ALLOW_INTS
2777	bool "Allow interrupts during APM BIOS calls"
2778	help
2779	  Normally we disable external interrupts while we are making calls to
2780	  the APM BIOS as a measure to lessen the effects of a badly behaving
2781	  BIOS implementation.  The BIOS should reenable interrupts if it
2782	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2783	  many of the newer IBM Thinkpads.  If you experience hangs when you
2784	  suspend, try setting this to Y.  Otherwise, say N.
2785
2786endif # APM
2787
2788source "drivers/cpufreq/Kconfig"
2789
2790source "drivers/cpuidle/Kconfig"
2791
2792source "drivers/idle/Kconfig"
2793
2794endmenu
2795
2796menu "Bus options (PCI etc.)"
2797
2798choice
2799	prompt "PCI access mode"
2800	depends on X86_32 && PCI
2801	default PCI_GOANY
2802	help
2803	  On PCI systems, the BIOS can be used to detect the PCI devices and
2804	  determine their configuration. However, some old PCI motherboards
2805	  have BIOS bugs and may crash if this is done. Also, some embedded
2806	  PCI-based systems don't have any BIOS at all. Linux can also try to
2807	  detect the PCI hardware directly without using the BIOS.
2808
2809	  With this option, you can specify how Linux should detect the
2810	  PCI devices. If you choose "BIOS", the BIOS will be used,
2811	  if you choose "Direct", the BIOS won't be used, and if you
2812	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2813	  If you choose "Any", the kernel will try MMCONFIG, then the
2814	  direct access method and falls back to the BIOS if that doesn't
2815	  work. If unsure, go with the default, which is "Any".
2816
2817config PCI_GOBIOS
2818	bool "BIOS"
2819
2820config PCI_GOMMCONFIG
2821	bool "MMConfig"
2822
2823config PCI_GODIRECT
2824	bool "Direct"
2825
2826config PCI_GOOLPC
2827	bool "OLPC XO-1"
2828	depends on OLPC
2829
2830config PCI_GOANY
2831	bool "Any"
2832
2833endchoice
2834
2835config PCI_BIOS
2836	def_bool y
2837	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2838
2839# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2840config PCI_DIRECT
2841	def_bool y
2842	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2843
2844config PCI_MMCONFIG
2845	bool "Support mmconfig PCI config space access" if X86_64
2846	default y
2847	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2848	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2849
2850config PCI_OLPC
2851	def_bool y
2852	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2853
2854config PCI_XEN
2855	def_bool y
2856	depends on PCI && XEN
2857
2858config MMCONF_FAM10H
2859	def_bool y
2860	depends on X86_64 && PCI_MMCONFIG && ACPI
2861
2862config PCI_CNB20LE_QUIRK
2863	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2864	depends on PCI
2865	help
2866	  Read the PCI windows out of the CNB20LE host bridge. This allows
2867	  PCI hotplug to work on systems with the CNB20LE chipset which do
2868	  not have ACPI.
2869
2870	  There's no public spec for this chipset, and this functionality
2871	  is known to be incomplete.
2872
2873	  You should say N unless you know you need this.
2874
2875config ISA_BUS
2876	bool "ISA bus support on modern systems" if EXPERT
2877	help
2878	  Expose ISA bus device drivers and options available for selection and
2879	  configuration. Enable this option if your target machine has an ISA
2880	  bus. ISA is an older system, displaced by PCI and newer bus
2881	  architectures -- if your target machine is modern, it probably does
2882	  not have an ISA bus.
2883
2884	  If unsure, say N.
2885
2886# x86_64 have no ISA slots, but can have ISA-style DMA.
2887config ISA_DMA_API
2888	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2889	default y
2890	help
2891	  Enables ISA-style DMA support for devices requiring such controllers.
2892	  If unsure, say Y.
2893
2894if X86_32
2895
2896config ISA
2897	bool "ISA support"
2898	help
2899	  Find out whether you have ISA slots on your motherboard.  ISA is the
2900	  name of a bus system, i.e. the way the CPU talks to the other stuff
2901	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2902	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2903	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2904
2905config SCx200
2906	tristate "NatSemi SCx200 support"
2907	help
2908	  This provides basic support for National Semiconductor's
2909	  (now AMD's) Geode processors.  The driver probes for the
2910	  PCI-IDs of several on-chip devices, so its a good dependency
2911	  for other scx200_* drivers.
2912
2913	  If compiled as a module, the driver is named scx200.
2914
2915config SCx200HR_TIMER
2916	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2917	depends on SCx200
2918	default y
2919	help
2920	  This driver provides a clocksource built upon the on-chip
2921	  27MHz high-resolution timer.  Its also a workaround for
2922	  NSC Geode SC-1100's buggy TSC, which loses time when the
2923	  processor goes idle (as is done by the scheduler).  The
2924	  other workaround is idle=poll boot option.
2925
2926config OLPC
2927	bool "One Laptop Per Child support"
2928	depends on !X86_PAE
2929	select GPIOLIB
2930	select OF
2931	select OF_PROMTREE
2932	select IRQ_DOMAIN
2933	select OLPC_EC
2934	help
2935	  Add support for detecting the unique features of the OLPC
2936	  XO hardware.
2937
2938config OLPC_XO1_PM
2939	bool "OLPC XO-1 Power Management"
2940	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2941	help
2942	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2943
2944config OLPC_XO1_RTC
2945	bool "OLPC XO-1 Real Time Clock"
2946	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2947	help
2948	  Add support for the XO-1 real time clock, which can be used as a
2949	  programmable wakeup source.
2950
2951config OLPC_XO1_SCI
2952	bool "OLPC XO-1 SCI extras"
2953	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2954	depends on INPUT=y
2955	select POWER_SUPPLY
2956	help
2957	  Add support for SCI-based features of the OLPC XO-1 laptop:
2958	   - EC-driven system wakeups
2959	   - Power button
2960	   - Ebook switch
2961	   - Lid switch
2962	   - AC adapter status updates
2963	   - Battery status updates
2964
2965config OLPC_XO15_SCI
2966	bool "OLPC XO-1.5 SCI extras"
2967	depends on OLPC && ACPI
2968	select POWER_SUPPLY
2969	help
2970	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2971	   - EC-driven system wakeups
2972	   - AC adapter status updates
2973	   - Battery status updates
2974
2975config ALIX
2976	bool "PCEngines ALIX System Support (LED setup)"
2977	select GPIOLIB
2978	help
2979	  This option enables system support for the PCEngines ALIX.
2980	  At present this just sets up LEDs for GPIO control on
2981	  ALIX2/3/6 boards.  However, other system specific setup should
2982	  get added here.
2983
2984	  Note: You must still enable the drivers for GPIO and LED support
2985	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2986
2987	  Note: You have to set alix.force=1 for boards with Award BIOS.
2988
2989config NET5501
2990	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2991	select GPIOLIB
2992	help
2993	  This option enables system support for the Soekris Engineering net5501.
2994
2995config GEOS
2996	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2997	select GPIOLIB
2998	depends on DMI
2999	help
3000	  This option enables system support for the Traverse Technologies GEOS.
3001
3002config TS5500
3003	bool "Technologic Systems TS-5500 platform support"
3004	depends on MELAN
3005	select CHECK_SIGNATURE
3006	select NEW_LEDS
3007	select LEDS_CLASS
3008	help
3009	  This option enables system support for the Technologic Systems TS-5500.
3010
3011endif # X86_32
3012
3013config AMD_NB
3014	def_bool y
3015	depends on CPU_SUP_AMD && PCI
3016
3017endmenu
3018
3019menu "Binary Emulations"
3020
3021config IA32_EMULATION
3022	bool "IA32 Emulation"
3023	depends on X86_64
3024	select ARCH_WANT_OLD_COMPAT_IPC
3025	select BINFMT_ELF
3026	select COMPAT_OLD_SIGACTION
3027	help
3028	  Include code to run legacy 32-bit programs under a
3029	  64-bit kernel. You should likely turn this on, unless you're
3030	  100% sure that you don't have any 32-bit programs left.
3031
3032config IA32_EMULATION_DEFAULT_DISABLED
3033	bool "IA32 emulation disabled by default"
3034	default n
3035	depends on IA32_EMULATION
3036	help
3037	  Make IA32 emulation disabled by default. This prevents loading 32-bit
3038	  processes and access to 32-bit syscalls. If unsure, leave it to its
3039	  default value.
3040
3041config X86_X32_ABI
3042	bool "x32 ABI for 64-bit mode"
3043	depends on X86_64
3044	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3045	# compressed debug sections to x86_x32 properly:
3046	# https://github.com/ClangBuiltLinux/linux/issues/514
3047	# https://github.com/ClangBuiltLinux/linux/issues/1141
3048	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3049	help
3050	  Include code to run binaries for the x32 native 32-bit ABI
3051	  for 64-bit processors.  An x32 process gets access to the
3052	  full 64-bit register file and wide data path while leaving
3053	  pointers at 32 bits for smaller memory footprint.
3054
3055config COMPAT_32
3056	def_bool y
3057	depends on IA32_EMULATION || X86_32
3058	select HAVE_UID16
3059	select OLD_SIGSUSPEND3
3060
3061config COMPAT
3062	def_bool y
3063	depends on IA32_EMULATION || X86_X32_ABI
3064
3065config COMPAT_FOR_U64_ALIGNMENT
3066	def_bool y
3067	depends on COMPAT
3068
3069endmenu
3070
3071config HAVE_ATOMIC_IOMAP
3072	def_bool y
3073	depends on X86_32
3074
3075source "arch/x86/kvm/Kconfig"
3076
3077source "arch/x86/Kconfig.assembler"
3078