xref: /openbmc/linux/arch/x86/Kconfig (revision 905e89190bafbc5d11a73e4f333354a47725633a)
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 ARCH_USE_CMPXCHG_LOCKREF
32	select HAVE_ARCH_SOFT_DIRTY
33	select MODULES_USE_ELF_RELA
34	select NEED_DMA_MAP_STATE
35	select SWIOTLB
36	select ARCH_HAS_ELFCORE_COMPAT
37	select ZONE_DMA32
38
39config FORCE_DYNAMIC_FTRACE
40	def_bool y
41	depends on X86_32
42	depends on FUNCTION_TRACER
43	select DYNAMIC_FTRACE
44	help
45	  We keep the static function tracing (!DYNAMIC_FTRACE) around
46	  in order to test the non static function tracing in the
47	  generic code, as other architectures still use it. But we
48	  only need to keep it around for x86_64. No need to keep it
49	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
50#
51# Arch settings
52#
53# ( Note that options that are marked 'if X86_64' could in principle be
54#   ported to 32-bit as well. )
55#
56config X86
57	def_bool y
58	#
59	# Note: keep this list sorted alphabetically
60	#
61	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
62	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
63	select ARCH_32BIT_OFF_T			if X86_32
64	select ARCH_CLOCKSOURCE_INIT
65	select ARCH_CONFIGURES_CPU_MITIGATIONS
66	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
67	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
68	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
69	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
70	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
71	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
72	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
73	select ARCH_HAS_CACHE_LINE_SIZE
74	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
75	select ARCH_HAS_CPU_FINALIZE_INIT
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_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
94	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
95	select ARCH_HAS_COPY_MC			if X86_64
96	select ARCH_HAS_SET_MEMORY
97	select ARCH_HAS_SET_DIRECT_MAP
98	select ARCH_HAS_STRICT_KERNEL_RWX
99	select ARCH_HAS_STRICT_MODULE_RWX
100	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
101	select ARCH_HAS_SYSCALL_WRAPPER
102	select ARCH_HAS_UBSAN_SANITIZE_ALL
103	select ARCH_HAS_DEBUG_WX
104	select ARCH_HAS_ZONE_DMA_SET if EXPERT
105	select ARCH_HAVE_NMI_SAFE_CMPXCHG
106	select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
107	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
108	select ARCH_MIGHT_HAVE_PC_PARPORT
109	select ARCH_MIGHT_HAVE_PC_SERIO
110	select ARCH_STACKWALK
111	select ARCH_SUPPORTS_ACPI
112	select ARCH_SUPPORTS_ATOMIC_RMW
113	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
114	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
115	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
116	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
117	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
118	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
119	select ARCH_SUPPORTS_LTO_CLANG
120	select ARCH_SUPPORTS_LTO_CLANG_THIN
121	select ARCH_USE_BUILTIN_BSWAP
122	select ARCH_USE_MEMTEST
123	select ARCH_USE_QUEUED_RWLOCKS
124	select ARCH_USE_QUEUED_SPINLOCKS
125	select ARCH_USE_SYM_ANNOTATIONS
126	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
127	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
128	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
129	select ARCH_WANTS_NO_INSTR
130	select ARCH_WANT_GENERAL_HUGETLB
131	select ARCH_WANT_HUGE_PMD_SHARE
132	select ARCH_WANT_LD_ORPHAN_WARN
133	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
134	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
135	select ARCH_WANTS_THP_SWAP		if X86_64
136	select ARCH_HAS_PARANOID_L1D_FLUSH
137	select BUILDTIME_TABLE_SORT
138	select CLKEVT_I8253
139	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
140	select CLOCKSOURCE_WATCHDOG
141	# Word-size accesses may read uninitialized data past the trailing \0
142	# in strings and cause false KMSAN reports.
143	select DCACHE_WORD_ACCESS		if !KMSAN
144	select DYNAMIC_SIGFRAME
145	select EDAC_ATOMIC_SCRUB
146	select EDAC_SUPPORT
147	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
148	select GENERIC_CLOCKEVENTS_MIN_ADJUST
149	select GENERIC_CMOS_UPDATE
150	select GENERIC_CPU_AUTOPROBE
151	select GENERIC_CPU_VULNERABILITIES
152	select GENERIC_EARLY_IOREMAP
153	select GENERIC_ENTRY
154	select GENERIC_IOMAP
155	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
156	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
157	select GENERIC_IRQ_MIGRATION		if SMP
158	select GENERIC_IRQ_PROBE
159	select GENERIC_IRQ_RESERVATION_MODE
160	select GENERIC_IRQ_SHOW
161	select GENERIC_PENDING_IRQ		if SMP
162	select GENERIC_PTDUMP
163	select GENERIC_SMP_IDLE_THREAD
164	select GENERIC_TIME_VSYSCALL
165	select GENERIC_GETTIMEOFDAY
166	select GENERIC_VDSO_TIME_NS
167	select GUP_GET_PXX_LOW_HIGH		if X86_PAE
168	select HARDIRQS_SW_RESEND
169	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
170	select HAS_IOPORT
171	select HAVE_ACPI_APEI			if ACPI
172	select HAVE_ACPI_APEI_NMI		if ACPI
173	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
174	select HAVE_ARCH_AUDITSYSCALL
175	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
176	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
177	select HAVE_ARCH_JUMP_LABEL
178	select HAVE_ARCH_JUMP_LABEL_RELATIVE
179	select HAVE_ARCH_KASAN			if X86_64
180	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
181	select HAVE_ARCH_KFENCE
182	select HAVE_ARCH_KMSAN			if X86_64
183	select HAVE_ARCH_KGDB
184	select HAVE_ARCH_MMAP_RND_BITS		if MMU
185	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
186	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
187	select HAVE_ARCH_PREL32_RELOCATIONS
188	select HAVE_ARCH_SECCOMP_FILTER
189	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
190	select HAVE_ARCH_STACKLEAK
191	select HAVE_ARCH_TRACEHOOK
192	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
193	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
194	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
195	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
196	select HAVE_ARCH_VMAP_STACK		if X86_64
197	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
198	select HAVE_ARCH_WITHIN_STACK_FRAMES
199	select HAVE_ASM_MODVERSIONS
200	select HAVE_CMPXCHG_DOUBLE
201	select HAVE_CMPXCHG_LOCAL
202	select HAVE_CONTEXT_TRACKING_USER		if X86_64
203	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
204	select HAVE_C_RECORDMCOUNT
205	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
206	select HAVE_OBJTOOL_NOP_MCOUNT		if HAVE_OBJTOOL_MCOUNT
207	select HAVE_BUILDTIME_MCOUNT_SORT
208	select HAVE_DEBUG_KMEMLEAK
209	select HAVE_DMA_CONTIGUOUS
210	select HAVE_DYNAMIC_FTRACE
211	select HAVE_DYNAMIC_FTRACE_WITH_REGS
212	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
213	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
214	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
215	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
216	select HAVE_EBPF_JIT
217	select HAVE_EFFICIENT_UNALIGNED_ACCESS
218	select HAVE_EISA
219	select HAVE_EXIT_THREAD
220	select HAVE_FAST_GUP
221	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
222	select HAVE_FTRACE_MCOUNT_RECORD
223	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
224	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
225	select HAVE_FUNCTION_TRACER
226	select HAVE_GCC_PLUGINS
227	select HAVE_HW_BREAKPOINT
228	select HAVE_IOREMAP_PROT
229	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
230	select HAVE_IRQ_TIME_ACCOUNTING
231	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
232	select HAVE_KERNEL_BZIP2
233	select HAVE_KERNEL_GZIP
234	select HAVE_KERNEL_LZ4
235	select HAVE_KERNEL_LZMA
236	select HAVE_KERNEL_LZO
237	select HAVE_KERNEL_XZ
238	select HAVE_KERNEL_ZSTD
239	select HAVE_KPROBES
240	select HAVE_KPROBES_ON_FTRACE
241	select HAVE_FUNCTION_ERROR_INJECTION
242	select HAVE_KRETPROBES
243	select HAVE_RETHOOK
244	select HAVE_KVM
245	select HAVE_LIVEPATCH			if X86_64
246	select HAVE_MIXED_BREAKPOINTS_REGS
247	select HAVE_MOD_ARCH_SPECIFIC
248	select HAVE_MOVE_PMD
249	select HAVE_MOVE_PUD
250	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
251	select HAVE_NMI
252	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
253	select HAVE_OBJTOOL			if X86_64
254	select HAVE_OPTPROBES
255	select HAVE_PCSPKR_PLATFORM
256	select HAVE_PERF_EVENTS
257	select HAVE_PERF_EVENTS_NMI
258	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
259	select HAVE_PCI
260	select HAVE_PERF_REGS
261	select HAVE_PERF_USER_STACK_DUMP
262	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
263	select MMU_GATHER_MERGE_VMAS
264	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
265	select HAVE_REGS_AND_STACK_ACCESS_API
266	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
267	select HAVE_FUNCTION_ARG_ACCESS_API
268	select HAVE_SETUP_PER_CPU_AREA
269	select HAVE_SOFTIRQ_ON_OWN_STACK
270	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
271	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
272	select HAVE_STATIC_CALL
273	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
274	select HAVE_PREEMPT_DYNAMIC_CALL
275	select HAVE_RSEQ
276	select HAVE_RUST			if X86_64
277	select HAVE_SYSCALL_TRACEPOINTS
278	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
279	select HAVE_UNSTABLE_SCHED_CLOCK
280	select HAVE_USER_RETURN_NOTIFIER
281	select HAVE_GENERIC_VDSO
282	select HOTPLUG_PARALLEL			if SMP && X86_64
283	select HOTPLUG_SMT			if SMP
284	select HOTPLUG_SPLIT_STARTUP		if SMP && X86_32
285	select IRQ_FORCED_THREADING
286	select LOCK_MM_AND_FIND_VMA
287	select NEED_PER_CPU_EMBED_FIRST_CHUNK
288	select NEED_PER_CPU_PAGE_FIRST_CHUNK
289	select NEED_SG_DMA_LENGTH
290	select PCI_DOMAINS			if PCI
291	select PCI_LOCKLESS_CONFIG		if PCI
292	select PERF_EVENTS
293	select RTC_LIB
294	select RTC_MC146818_LIB
295	select SPARSE_IRQ
296	select SYSCTL_EXCEPTION_TRACE
297	select THREAD_INFO_IN_TASK
298	select TRACE_IRQFLAGS_SUPPORT
299	select TRACE_IRQFLAGS_NMI_SUPPORT
300	select USER_STACKTRACE_SUPPORT
301	select HAVE_ARCH_KCSAN			if X86_64
302	select PROC_PID_ARCH_STATUS		if PROC_FS
303	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
304	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
305	select FUNCTION_ALIGNMENT_4B
306	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
307	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
308
309config INSTRUCTION_DECODER
310	def_bool y
311	depends on KPROBES || PERF_EVENTS || UPROBES
312
313config OUTPUT_FORMAT
314	string
315	default "elf32-i386" if X86_32
316	default "elf64-x86-64" if X86_64
317
318config LOCKDEP_SUPPORT
319	def_bool y
320
321config STACKTRACE_SUPPORT
322	def_bool y
323
324config MMU
325	def_bool y
326
327config ARCH_MMAP_RND_BITS_MIN
328	default 28 if 64BIT
329	default 8
330
331config ARCH_MMAP_RND_BITS_MAX
332	default 32 if 64BIT
333	default 16
334
335config ARCH_MMAP_RND_COMPAT_BITS_MIN
336	default 8
337
338config ARCH_MMAP_RND_COMPAT_BITS_MAX
339	default 16
340
341config SBUS
342	bool
343
344config GENERIC_ISA_DMA
345	def_bool y
346	depends on ISA_DMA_API
347
348config GENERIC_CSUM
349	bool
350	default y if KMSAN || KASAN
351
352config GENERIC_BUG
353	def_bool y
354	depends on BUG
355	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
356
357config GENERIC_BUG_RELATIVE_POINTERS
358	bool
359
360config ARCH_MAY_HAVE_PC_FDC
361	def_bool y
362	depends on ISA_DMA_API
363
364config GENERIC_CALIBRATE_DELAY
365	def_bool y
366
367config ARCH_HAS_CPU_RELAX
368	def_bool y
369
370config ARCH_HIBERNATION_POSSIBLE
371	def_bool y
372
373config ARCH_SUSPEND_POSSIBLE
374	def_bool y
375
376config AUDIT_ARCH
377	def_bool y if X86_64
378
379config KASAN_SHADOW_OFFSET
380	hex
381	depends on KASAN
382	default 0xdffffc0000000000
383
384config HAVE_INTEL_TXT
385	def_bool y
386	depends on INTEL_IOMMU && ACPI
387
388config X86_32_SMP
389	def_bool y
390	depends on X86_32 && SMP
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 GOLDFISH
476	def_bool y
477	depends on X86_GOLDFISH
478
479config X86_CPU_RESCTRL
480	bool "x86 CPU resource control support"
481	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
482	select KERNFS
483	select PROC_CPU_RESCTRL		if PROC_FS
484	help
485	  Enable x86 CPU resource control support.
486
487	  Provide support for the allocation and monitoring of system resources
488	  usage by the CPU.
489
490	  Intel calls this Intel Resource Director Technology
491	  (Intel(R) RDT). More information about RDT can be found in the
492	  Intel x86 Architecture Software Developer Manual.
493
494	  AMD calls this AMD Platform Quality of Service (AMD QoS).
495	  More information about AMD QoS can be found in the AMD64 Technology
496	  Platform Quality of Service Extensions manual.
497
498	  Say N if unsure.
499
500if X86_32
501config X86_BIGSMP
502	bool "Support for big SMP systems with more than 8 CPUs"
503	depends on SMP
504	help
505	  This option is needed for the systems that have more than 8 CPUs.
506
507config X86_EXTENDED_PLATFORM
508	bool "Support for extended (non-PC) x86 platforms"
509	default y
510	help
511	  If you disable this option then the kernel will only support
512	  standard PC platforms. (which covers the vast majority of
513	  systems out there.)
514
515	  If you enable this option then you'll be able to select support
516	  for the following (non-PC) 32 bit x86 platforms:
517		Goldfish (Android emulator)
518		AMD Elan
519		RDC R-321x SoC
520		SGI 320/540 (Visual Workstation)
521		STA2X11-based (e.g. Northville)
522		Moorestown MID devices
523
524	  If you have one of these systems, or if you want to build a
525	  generic distribution kernel, say Y here - otherwise say N.
526endif # X86_32
527
528if X86_64
529config X86_EXTENDED_PLATFORM
530	bool "Support for extended (non-PC) x86 platforms"
531	default y
532	help
533	  If you disable this option then the kernel will only support
534	  standard PC platforms. (which covers the vast majority of
535	  systems out there.)
536
537	  If you enable this option then you'll be able to select support
538	  for the following (non-PC) 64 bit x86 platforms:
539		Numascale NumaChip
540		ScaleMP vSMP
541		SGI Ultraviolet
542
543	  If you have one of these systems, or if you want to build a
544	  generic distribution kernel, say Y here - otherwise say N.
545endif # X86_64
546# This is an alphabetically sorted list of 64 bit extended platforms
547# Please maintain the alphabetic order if and when there are additions
548config X86_NUMACHIP
549	bool "Numascale NumaChip"
550	depends on X86_64
551	depends on X86_EXTENDED_PLATFORM
552	depends on NUMA
553	depends on SMP
554	depends on X86_X2APIC
555	depends on PCI_MMCONFIG
556	help
557	  Adds support for Numascale NumaChip large-SMP systems. Needed to
558	  enable more than ~168 cores.
559	  If you don't have one of these, you should say N here.
560
561config X86_VSMP
562	bool "ScaleMP vSMP"
563	select HYPERVISOR_GUEST
564	select PARAVIRT
565	depends on X86_64 && PCI
566	depends on X86_EXTENDED_PLATFORM
567	depends on SMP
568	help
569	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
570	  supposed to run on these EM64T-based machines.  Only choose this option
571	  if you have one of these machines.
572
573config X86_UV
574	bool "SGI Ultraviolet"
575	depends on X86_64
576	depends on X86_EXTENDED_PLATFORM
577	depends on NUMA
578	depends on EFI
579	depends on KEXEC_CORE
580	depends on X86_X2APIC
581	depends on PCI
582	help
583	  This option is needed in order to support SGI Ultraviolet systems.
584	  If you don't have one of these, you should say N here.
585
586# Following is an alphabetically sorted list of 32 bit extended platforms
587# Please maintain the alphabetic order if and when there are additions
588
589config X86_GOLDFISH
590	bool "Goldfish (Virtual Platform)"
591	depends on X86_EXTENDED_PLATFORM
592	help
593	  Enable support for the Goldfish virtual platform used primarily
594	  for Android development. Unless you are building for the Android
595	  Goldfish emulator say N here.
596
597config X86_INTEL_CE
598	bool "CE4100 TV platform"
599	depends on PCI
600	depends on PCI_GODIRECT
601	depends on X86_IO_APIC
602	depends on X86_32
603	depends on X86_EXTENDED_PLATFORM
604	select X86_REBOOTFIXUPS
605	select OF
606	select OF_EARLY_FLATTREE
607	help
608	  Select for the Intel CE media processor (CE4100) SOC.
609	  This option compiles in support for the CE4100 SOC for settop
610	  boxes and media devices.
611
612config X86_INTEL_MID
613	bool "Intel MID platform support"
614	depends on X86_EXTENDED_PLATFORM
615	depends on X86_PLATFORM_DEVICES
616	depends on PCI
617	depends on X86_64 || (PCI_GOANY && X86_32)
618	depends on X86_IO_APIC
619	select I2C
620	select DW_APB_TIMER
621	select INTEL_SCU_PCI
622	help
623	  Select to build a kernel capable of supporting Intel MID (Mobile
624	  Internet Device) platform systems which do not have the PCI legacy
625	  interfaces. If you are building for a PC class system say N here.
626
627	  Intel MID platforms are based on an Intel processor and chipset which
628	  consume less power than most of the x86 derivatives.
629
630config X86_INTEL_QUARK
631	bool "Intel Quark platform support"
632	depends on X86_32
633	depends on X86_EXTENDED_PLATFORM
634	depends on X86_PLATFORM_DEVICES
635	depends on X86_TSC
636	depends on PCI
637	depends on PCI_GOANY
638	depends on X86_IO_APIC
639	select IOSF_MBI
640	select INTEL_IMR
641	select COMMON_CLK
642	help
643	  Select to include support for Quark X1000 SoC.
644	  Say Y here if you have a Quark based system such as the Arduino
645	  compatible Intel Galileo.
646
647config X86_INTEL_LPSS
648	bool "Intel Low Power Subsystem Support"
649	depends on X86 && ACPI && PCI
650	select COMMON_CLK
651	select PINCTRL
652	select IOSF_MBI
653	help
654	  Select to build support for Intel Low Power Subsystem such as
655	  found on Intel Lynxpoint PCH. Selecting this option enables
656	  things like clock tree (common clock framework) and pincontrol
657	  which are needed by the LPSS peripheral drivers.
658
659config X86_AMD_PLATFORM_DEVICE
660	bool "AMD ACPI2Platform devices support"
661	depends on ACPI
662	select COMMON_CLK
663	select PINCTRL
664	help
665	  Select to interpret AMD specific ACPI device to platform device
666	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
667	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
668	  implemented under PINCTRL subsystem.
669
670config IOSF_MBI
671	tristate "Intel SoC IOSF Sideband support for SoC platforms"
672	depends on PCI
673	help
674	  This option enables sideband register access support for Intel SoC
675	  platforms. On these platforms the IOSF sideband is used in lieu of
676	  MSR's for some register accesses, mostly but not limited to thermal
677	  and power. Drivers may query the availability of this device to
678	  determine if they need the sideband in order to work on these
679	  platforms. The sideband is available on the following SoC products.
680	  This list is not meant to be exclusive.
681	   - BayTrail
682	   - Braswell
683	   - Quark
684
685	  You should say Y if you are running a kernel on one of these SoC's.
686
687config IOSF_MBI_DEBUG
688	bool "Enable IOSF sideband access through debugfs"
689	depends on IOSF_MBI && DEBUG_FS
690	help
691	  Select this option to expose the IOSF sideband access registers (MCR,
692	  MDR, MCRX) through debugfs to write and read register information from
693	  different units on the SoC. This is most useful for obtaining device
694	  state information for debug and analysis. As this is a general access
695	  mechanism, users of this option would have specific knowledge of the
696	  device they want to access.
697
698	  If you don't require the option or are in doubt, say N.
699
700config X86_RDC321X
701	bool "RDC R-321x SoC"
702	depends on X86_32
703	depends on X86_EXTENDED_PLATFORM
704	select M486
705	select X86_REBOOTFIXUPS
706	help
707	  This option is needed for RDC R-321x system-on-chip, also known
708	  as R-8610-(G).
709	  If you don't have one of these chips, you should say N here.
710
711config X86_32_NON_STANDARD
712	bool "Support non-standard 32-bit SMP architectures"
713	depends on X86_32 && SMP
714	depends on X86_EXTENDED_PLATFORM
715	help
716	  This option compiles in the bigsmp and STA2X11 default
717	  subarchitectures.  It is intended for a generic binary
718	  kernel. If you select them all, kernel will probe it one by
719	  one and will fallback to default.
720
721# Alphabetically sorted list of Non standard 32 bit platforms
722
723config X86_SUPPORTS_MEMORY_FAILURE
724	def_bool y
725	# MCE code calls memory_failure():
726	depends on X86_MCE
727	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
728	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
729	depends on X86_64 || !SPARSEMEM
730	select ARCH_SUPPORTS_MEMORY_FAILURE
731
732config STA2X11
733	bool "STA2X11 Companion Chip Support"
734	depends on X86_32_NON_STANDARD && PCI
735	select SWIOTLB
736	select MFD_STA2X11
737	select GPIOLIB
738	help
739	  This adds support for boards based on the STA2X11 IO-Hub,
740	  a.k.a. "ConneXt". The chip is used in place of the standard
741	  PC chipset, so all "standard" peripherals are missing. If this
742	  option is selected the kernel will still be able to boot on
743	  standard PC machines.
744
745config X86_32_IRIS
746	tristate "Eurobraille/Iris poweroff module"
747	depends on X86_32
748	help
749	  The Iris machines from EuroBraille do not have APM or ACPI support
750	  to shut themselves down properly.  A special I/O sequence is
751	  needed to do so, which is what this module does at
752	  kernel shutdown.
753
754	  This is only for Iris machines from EuroBraille.
755
756	  If unused, say N.
757
758config SCHED_OMIT_FRAME_POINTER
759	def_bool y
760	prompt "Single-depth WCHAN output"
761	depends on X86
762	help
763	  Calculate simpler /proc/<PID>/wchan values. If this option
764	  is disabled then wchan values will recurse back to the
765	  caller function. This provides more accurate wchan values,
766	  at the expense of slightly more scheduling overhead.
767
768	  If in doubt, say "Y".
769
770menuconfig HYPERVISOR_GUEST
771	bool "Linux guest support"
772	help
773	  Say Y here to enable options for running Linux under various hyper-
774	  visors. This option enables basic hypervisor detection and platform
775	  setup.
776
777	  If you say N, all options in this submenu will be skipped and
778	  disabled, and Linux guest support won't be built in.
779
780if HYPERVISOR_GUEST
781
782config PARAVIRT
783	bool "Enable paravirtualization code"
784	depends on HAVE_STATIC_CALL
785	help
786	  This changes the kernel so it can modify itself when it is run
787	  under a hypervisor, potentially improving performance significantly
788	  over full virtualization.  However, when run without a hypervisor
789	  the kernel is theoretically slower and slightly larger.
790
791config PARAVIRT_XXL
792	bool
793
794config PARAVIRT_DEBUG
795	bool "paravirt-ops debugging"
796	depends on PARAVIRT && DEBUG_KERNEL
797	help
798	  Enable to debug paravirt_ops internals.  Specifically, BUG if
799	  a paravirt_op is missing when it is called.
800
801config PARAVIRT_SPINLOCKS
802	bool "Paravirtualization layer for spinlocks"
803	depends on PARAVIRT && SMP
804	help
805	  Paravirtualized spinlocks allow a pvops backend to replace the
806	  spinlock implementation with something virtualization-friendly
807	  (for example, block the virtual CPU rather than spinning).
808
809	  It has a minimal impact on native kernels and gives a nice performance
810	  benefit on paravirtualized KVM / Xen kernels.
811
812	  If you are unsure how to answer this question, answer Y.
813
814config X86_HV_CALLBACK_VECTOR
815	def_bool n
816
817source "arch/x86/xen/Kconfig"
818
819config KVM_GUEST
820	bool "KVM Guest support (including kvmclock)"
821	depends on PARAVIRT
822	select PARAVIRT_CLOCK
823	select ARCH_CPUIDLE_HALTPOLL
824	select X86_HV_CALLBACK_VECTOR
825	default y
826	help
827	  This option enables various optimizations for running under the KVM
828	  hypervisor. It includes a paravirtualized clock, so that instead
829	  of relying on a PIT (or probably other) emulation by the
830	  underlying device model, the host provides the guest with
831	  timing infrastructure such as time of day, and system time
832
833config ARCH_CPUIDLE_HALTPOLL
834	def_bool n
835	prompt "Disable host haltpoll when loading haltpoll driver"
836	help
837	  If virtualized under KVM, disable host haltpoll.
838
839config PVH
840	bool "Support for running PVH guests"
841	help
842	  This option enables the PVH entry point for guest virtual machines
843	  as specified in the x86/HVM direct boot ABI.
844
845config PARAVIRT_TIME_ACCOUNTING
846	bool "Paravirtual steal time accounting"
847	depends on PARAVIRT
848	help
849	  Select this option to enable fine granularity task steal time
850	  accounting. Time spent executing other tasks in parallel with
851	  the current vCPU is discounted from the vCPU power. To account for
852	  that, there can be a small performance impact.
853
854	  If in doubt, say N here.
855
856config PARAVIRT_CLOCK
857	bool
858
859config JAILHOUSE_GUEST
860	bool "Jailhouse non-root cell support"
861	depends on X86_64 && PCI
862	select X86_PM_TIMER
863	help
864	  This option allows to run Linux as guest in a Jailhouse non-root
865	  cell. You can leave this option disabled if you only want to start
866	  Jailhouse and run Linux afterwards in the root cell.
867
868config ACRN_GUEST
869	bool "ACRN Guest support"
870	depends on X86_64
871	select X86_HV_CALLBACK_VECTOR
872	help
873	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
874	  a flexible, lightweight reference open-source hypervisor, built with
875	  real-time and safety-criticality in mind. It is built for embedded
876	  IOT with small footprint and real-time features. More details can be
877	  found in https://projectacrn.org/.
878
879config INTEL_TDX_GUEST
880	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
881	depends on X86_64 && CPU_SUP_INTEL
882	depends on X86_X2APIC
883	depends on EFI_STUB
884	select ARCH_HAS_CC_PLATFORM
885	select X86_MEM_ENCRYPT
886	select X86_MCE
887	select UNACCEPTED_MEMORY
888	help
889	  Support running as a guest under Intel TDX.  Without this support,
890	  the guest kernel can not boot or run under TDX.
891	  TDX includes memory encryption and integrity capabilities
892	  which protect the confidentiality and integrity of guest
893	  memory contents and CPU state. TDX guests are protected from
894	  some attacks from the VMM.
895
896endif # HYPERVISOR_GUEST
897
898source "arch/x86/Kconfig.cpu"
899
900config HPET_TIMER
901	def_bool X86_64
902	prompt "HPET Timer Support" if X86_32
903	help
904	  Use the IA-PC HPET (High Precision Event Timer) to manage
905	  time in preference to the PIT and RTC, if a HPET is
906	  present.
907	  HPET is the next generation timer replacing legacy 8254s.
908	  The HPET provides a stable time base on SMP
909	  systems, unlike the TSC, but it is more expensive to access,
910	  as it is off-chip.  The interface used is documented
911	  in the HPET spec, revision 1.
912
913	  You can safely choose Y here.  However, HPET will only be
914	  activated if the platform and the BIOS support this feature.
915	  Otherwise the 8254 will be used for timing services.
916
917	  Choose N to continue using the legacy 8254 timer.
918
919config HPET_EMULATE_RTC
920	def_bool y
921	depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
922
923# Mark as expert because too many people got it wrong.
924# The code disables itself when not needed.
925config DMI
926	default y
927	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
928	bool "Enable DMI scanning" if EXPERT
929	help
930	  Enabled scanning of DMI to identify machine quirks. Say Y
931	  here unless you have verified that your setup is not
932	  affected by entries in the DMI blacklist. Required by PNP
933	  BIOS code.
934
935config GART_IOMMU
936	bool "Old AMD GART IOMMU support"
937	select DMA_OPS
938	select IOMMU_HELPER
939	select SWIOTLB
940	depends on X86_64 && PCI && AMD_NB
941	help
942	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
943	  GART based hardware IOMMUs.
944
945	  The GART supports full DMA access for devices with 32-bit access
946	  limitations, on systems with more than 3 GB. This is usually needed
947	  for USB, sound, many IDE/SATA chipsets and some other devices.
948
949	  Newer systems typically have a modern AMD IOMMU, supported via
950	  the CONFIG_AMD_IOMMU=y config option.
951
952	  In normal configurations this driver is only active when needed:
953	  there's more than 3 GB of memory and the system contains a
954	  32-bit limited device.
955
956	  If unsure, say Y.
957
958config BOOT_VESA_SUPPORT
959	bool
960	help
961	  If true, at least one selected framebuffer driver can take advantage
962	  of VESA video modes set at an early boot stage via the vga= parameter.
963
964config MAXSMP
965	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
966	depends on X86_64 && SMP && DEBUG_KERNEL
967	select CPUMASK_OFFSTACK
968	help
969	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
970	  If unsure, say N.
971
972#
973# The maximum number of CPUs supported:
974#
975# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
976# and which can be configured interactively in the
977# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
978#
979# The ranges are different on 32-bit and 64-bit kernels, depending on
980# hardware capabilities and scalability features of the kernel.
981#
982# ( If MAXSMP is enabled we just use the highest possible value and disable
983#   interactive configuration. )
984#
985
986config NR_CPUS_RANGE_BEGIN
987	int
988	default NR_CPUS_RANGE_END if MAXSMP
989	default    1 if !SMP
990	default    2
991
992config NR_CPUS_RANGE_END
993	int
994	depends on X86_32
995	default   64 if  SMP &&  X86_BIGSMP
996	default    8 if  SMP && !X86_BIGSMP
997	default    1 if !SMP
998
999config NR_CPUS_RANGE_END
1000	int
1001	depends on X86_64
1002	default 8192 if  SMP && CPUMASK_OFFSTACK
1003	default  512 if  SMP && !CPUMASK_OFFSTACK
1004	default    1 if !SMP
1005
1006config NR_CPUS_DEFAULT
1007	int
1008	depends on X86_32
1009	default   32 if  X86_BIGSMP
1010	default    8 if  SMP
1011	default    1 if !SMP
1012
1013config NR_CPUS_DEFAULT
1014	int
1015	depends on X86_64
1016	default 8192 if  MAXSMP
1017	default   64 if  SMP
1018	default    1 if !SMP
1019
1020config NR_CPUS
1021	int "Maximum number of CPUs" if SMP && !MAXSMP
1022	range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1023	default NR_CPUS_DEFAULT
1024	help
1025	  This allows you to specify the maximum number of CPUs which this
1026	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
1027	  supported value is 8192, otherwise the maximum value is 512.  The
1028	  minimum value which makes sense is 2.
1029
1030	  This is purely to save memory: each supported CPU adds about 8KB
1031	  to the kernel image.
1032
1033config SCHED_CLUSTER
1034	bool "Cluster scheduler support"
1035	depends on SMP
1036	default y
1037	help
1038	  Cluster scheduler support improves the CPU scheduler's decision
1039	  making when dealing with machines that have clusters of CPUs.
1040	  Cluster usually means a couple of CPUs which are placed closely
1041	  by sharing mid-level caches, last-level cache tags or internal
1042	  busses.
1043
1044config SCHED_SMT
1045	def_bool y if SMP
1046
1047config SCHED_MC
1048	def_bool y
1049	prompt "Multi-core scheduler support"
1050	depends on SMP
1051	help
1052	  Multi-core scheduler support improves the CPU scheduler's decision
1053	  making when dealing with multi-core CPU chips at a cost of slightly
1054	  increased overhead in some places. If unsure say N here.
1055
1056config SCHED_MC_PRIO
1057	bool "CPU core priorities scheduler support"
1058	depends on SCHED_MC && CPU_SUP_INTEL
1059	select X86_INTEL_PSTATE
1060	select CPU_FREQ
1061	default y
1062	help
1063	  Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1064	  core ordering determined at manufacturing time, which allows
1065	  certain cores to reach higher turbo frequencies (when running
1066	  single threaded workloads) than others.
1067
1068	  Enabling this kernel feature teaches the scheduler about
1069	  the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1070	  scheduler's CPU selection logic accordingly, so that higher
1071	  overall system performance can be achieved.
1072
1073	  This feature will have no effect on CPUs without this feature.
1074
1075	  If unsure say Y here.
1076
1077config UP_LATE_INIT
1078	def_bool y
1079	depends on !SMP && X86_LOCAL_APIC
1080
1081config X86_UP_APIC
1082	bool "Local APIC support on uniprocessors" if !PCI_MSI
1083	default PCI_MSI
1084	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1085	help
1086	  A local APIC (Advanced Programmable Interrupt Controller) is an
1087	  integrated interrupt controller in the CPU. If you have a single-CPU
1088	  system which has a processor with a local APIC, you can say Y here to
1089	  enable and use it. If you say Y here even though your machine doesn't
1090	  have a local APIC, then the kernel will still run with no slowdown at
1091	  all. The local APIC supports CPU-generated self-interrupts (timer,
1092	  performance counters), and the NMI watchdog which detects hard
1093	  lockups.
1094
1095config X86_UP_IOAPIC
1096	bool "IO-APIC support on uniprocessors"
1097	depends on X86_UP_APIC
1098	help
1099	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1100	  SMP-capable replacement for PC-style interrupt controllers. Most
1101	  SMP systems and many recent uniprocessor systems have one.
1102
1103	  If you have a single-CPU system with an IO-APIC, you can say Y here
1104	  to use it. If you say Y here even though your machine doesn't have
1105	  an IO-APIC, then the kernel will still run with no slowdown at all.
1106
1107config X86_LOCAL_APIC
1108	def_bool y
1109	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1110	select IRQ_DOMAIN_HIERARCHY
1111
1112config X86_IO_APIC
1113	def_bool y
1114	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1115
1116config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1117	bool "Reroute for broken boot IRQs"
1118	depends on X86_IO_APIC
1119	help
1120	  This option enables a workaround that fixes a source of
1121	  spurious interrupts. This is recommended when threaded
1122	  interrupt handling is used on systems where the generation of
1123	  superfluous "boot interrupts" cannot be disabled.
1124
1125	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1126	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
1127	  kernel does during interrupt handling). On chipsets where this
1128	  boot IRQ generation cannot be disabled, this workaround keeps
1129	  the original IRQ line masked so that only the equivalent "boot
1130	  IRQ" is delivered to the CPUs. The workaround also tells the
1131	  kernel to set up the IRQ handler on the boot IRQ line. In this
1132	  way only one interrupt is delivered to the kernel. Otherwise
1133	  the spurious second interrupt may cause the kernel to bring
1134	  down (vital) interrupt lines.
1135
1136	  Only affects "broken" chipsets. Interrupt sharing may be
1137	  increased on these systems.
1138
1139config X86_MCE
1140	bool "Machine Check / overheating reporting"
1141	select GENERIC_ALLOCATOR
1142	default y
1143	help
1144	  Machine Check support allows the processor to notify the
1145	  kernel if it detects a problem (e.g. overheating, data corruption).
1146	  The action the kernel takes depends on the severity of the problem,
1147	  ranging from warning messages to halting the machine.
1148
1149config X86_MCELOG_LEGACY
1150	bool "Support for deprecated /dev/mcelog character device"
1151	depends on X86_MCE
1152	help
1153	  Enable support for /dev/mcelog which is needed by the old mcelog
1154	  userspace logging daemon. Consider switching to the new generation
1155	  rasdaemon solution.
1156
1157config X86_MCE_INTEL
1158	def_bool y
1159	prompt "Intel MCE features"
1160	depends on X86_MCE && X86_LOCAL_APIC
1161	help
1162	  Additional support for intel specific MCE features such as
1163	  the thermal monitor.
1164
1165config X86_MCE_AMD
1166	def_bool y
1167	prompt "AMD MCE features"
1168	depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1169	help
1170	  Additional support for AMD specific MCE features such as
1171	  the DRAM Error Threshold.
1172
1173config X86_ANCIENT_MCE
1174	bool "Support for old Pentium 5 / WinChip machine checks"
1175	depends on X86_32 && X86_MCE
1176	help
1177	  Include support for machine check handling on old Pentium 5 or WinChip
1178	  systems. These typically need to be enabled explicitly on the command
1179	  line.
1180
1181config X86_MCE_THRESHOLD
1182	depends on X86_MCE_AMD || X86_MCE_INTEL
1183	def_bool y
1184
1185config X86_MCE_INJECT
1186	depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1187	tristate "Machine check injector support"
1188	help
1189	  Provide support for injecting machine checks for testing purposes.
1190	  If you don't know what a machine check is and you don't do kernel
1191	  QA it is safe to say n.
1192
1193source "arch/x86/events/Kconfig"
1194
1195config X86_LEGACY_VM86
1196	bool "Legacy VM86 support"
1197	depends on X86_32
1198	help
1199	  This option allows user programs to put the CPU into V8086
1200	  mode, which is an 80286-era approximation of 16-bit real mode.
1201
1202	  Some very old versions of X and/or vbetool require this option
1203	  for user mode setting.  Similarly, DOSEMU will use it if
1204	  available to accelerate real mode DOS programs.  However, any
1205	  recent version of DOSEMU, X, or vbetool should be fully
1206	  functional even without kernel VM86 support, as they will all
1207	  fall back to software emulation. Nevertheless, if you are using
1208	  a 16-bit DOS program where 16-bit performance matters, vm86
1209	  mode might be faster than emulation and you might want to
1210	  enable this option.
1211
1212	  Note that any app that works on a 64-bit kernel is unlikely to
1213	  need this option, as 64-bit kernels don't, and can't, support
1214	  V8086 mode. This option is also unrelated to 16-bit protected
1215	  mode and is not needed to run most 16-bit programs under Wine.
1216
1217	  Enabling this option increases the complexity of the kernel
1218	  and slows down exception handling a tiny bit.
1219
1220	  If unsure, say N here.
1221
1222config VM86
1223	bool
1224	default X86_LEGACY_VM86
1225
1226config X86_16BIT
1227	bool "Enable support for 16-bit segments" if EXPERT
1228	default y
1229	depends on MODIFY_LDT_SYSCALL
1230	help
1231	  This option is required by programs like Wine to run 16-bit
1232	  protected mode legacy code on x86 processors.  Disabling
1233	  this option saves about 300 bytes on i386, or around 6K text
1234	  plus 16K runtime memory on x86-64,
1235
1236config X86_ESPFIX32
1237	def_bool y
1238	depends on X86_16BIT && X86_32
1239
1240config X86_ESPFIX64
1241	def_bool y
1242	depends on X86_16BIT && X86_64
1243
1244config X86_VSYSCALL_EMULATION
1245	bool "Enable vsyscall emulation" if EXPERT
1246	default y
1247	depends on X86_64
1248	help
1249	  This enables emulation of the legacy vsyscall page.  Disabling
1250	  it is roughly equivalent to booting with vsyscall=none, except
1251	  that it will also disable the helpful warning if a program
1252	  tries to use a vsyscall.  With this option set to N, offending
1253	  programs will just segfault, citing addresses of the form
1254	  0xffffffffff600?00.
1255
1256	  This option is required by many programs built before 2013, and
1257	  care should be used even with newer programs if set to N.
1258
1259	  Disabling this option saves about 7K of kernel size and
1260	  possibly 4K of additional runtime pagetable memory.
1261
1262config X86_IOPL_IOPERM
1263	bool "IOPERM and IOPL Emulation"
1264	default y
1265	help
1266	  This enables the ioperm() and iopl() syscalls which are necessary
1267	  for legacy applications.
1268
1269	  Legacy IOPL support is an overbroad mechanism which allows user
1270	  space aside of accessing all 65536 I/O ports also to disable
1271	  interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1272	  capabilities and permission from potentially active security
1273	  modules.
1274
1275	  The emulation restricts the functionality of the syscall to
1276	  only allowing the full range I/O port access, but prevents the
1277	  ability to disable interrupts from user space which would be
1278	  granted if the hardware IOPL mechanism would be used.
1279
1280config TOSHIBA
1281	tristate "Toshiba Laptop support"
1282	depends on X86_32
1283	help
1284	  This adds a driver to safely access the System Management Mode of
1285	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1286	  not work on models with a Phoenix BIOS. The System Management Mode
1287	  is used to set the BIOS and power saving options on Toshiba portables.
1288
1289	  For information on utilities to make use of this driver see the
1290	  Toshiba Linux utilities web site at:
1291	  <http://www.buzzard.org.uk/toshiba/>.
1292
1293	  Say Y if you intend to run this kernel on a Toshiba portable.
1294	  Say N otherwise.
1295
1296config X86_REBOOTFIXUPS
1297	bool "Enable X86 board specific fixups for reboot"
1298	depends on X86_32
1299	help
1300	  This enables chipset and/or board specific fixups to be done
1301	  in order to get reboot to work correctly. This is only needed on
1302	  some combinations of hardware and BIOS. The symptom, for which
1303	  this config is intended, is when reboot ends with a stalled/hung
1304	  system.
1305
1306	  Currently, the only fixup is for the Geode machines using
1307	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1308
1309	  Say Y if you want to enable the fixup. Currently, it's safe to
1310	  enable this option even if you don't need it.
1311	  Say N otherwise.
1312
1313config MICROCODE
1314	def_bool y
1315	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1316	select CRYPTO_LIB_SHA256 if CPU_SUP_AMD
1317
1318config MICROCODE_INITRD32
1319	def_bool y
1320	depends on MICROCODE && X86_32 && BLK_DEV_INITRD
1321
1322config MICROCODE_LATE_LOADING
1323	bool "Late microcode loading (DANGEROUS)"
1324	default n
1325	depends on MICROCODE && SMP
1326	help
1327	  Loading microcode late, when the system is up and executing instructions
1328	  is a tricky business and should be avoided if possible. Just the sequence
1329	  of synchronizing all cores and SMT threads is one fragile dance which does
1330	  not guarantee that cores might not softlock after the loading. Therefore,
1331	  use this at your own risk. Late loading taints the kernel unless the
1332	  microcode header indicates that it is safe for late loading via the
1333	  minimal revision check. This minimal revision check can be enforced on
1334	  the kernel command line with "microcode.minrev=Y".
1335
1336config MICROCODE_LATE_FORCE_MINREV
1337	bool "Enforce late microcode loading minimal revision check"
1338	default n
1339	depends on MICROCODE_LATE_LOADING
1340	help
1341	  To prevent that users load microcode late which modifies already
1342	  in use features, newer microcode patches have a minimum revision field
1343	  in the microcode header, which tells the kernel which minimum
1344	  revision must be active in the CPU to safely load that new microcode
1345	  late into the running system. If disabled the check will not
1346	  be enforced but the kernel will be tainted when the minimal
1347	  revision check fails.
1348
1349	  This minimal revision check can also be controlled via the
1350	  "microcode.minrev" parameter on the kernel command line.
1351
1352	  If unsure say Y.
1353
1354config X86_MSR
1355	tristate "/dev/cpu/*/msr - Model-specific register support"
1356	help
1357	  This device gives privileged processes access to the x86
1358	  Model-Specific Registers (MSRs).  It is a character device with
1359	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1360	  MSR accesses are directed to a specific CPU on multi-processor
1361	  systems.
1362
1363config X86_CPUID
1364	tristate "/dev/cpu/*/cpuid - CPU information support"
1365	help
1366	  This device gives processes access to the x86 CPUID instruction to
1367	  be executed on a specific processor.  It is a character device
1368	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1369	  /dev/cpu/31/cpuid.
1370
1371choice
1372	prompt "High Memory Support"
1373	default HIGHMEM4G
1374	depends on X86_32
1375
1376config NOHIGHMEM
1377	bool "off"
1378	help
1379	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1380	  However, the address space of 32-bit x86 processors is only 4
1381	  Gigabytes large. That means that, if you have a large amount of
1382	  physical memory, not all of it can be "permanently mapped" by the
1383	  kernel. The physical memory that's not permanently mapped is called
1384	  "high memory".
1385
1386	  If you are compiling a kernel which will never run on a machine with
1387	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1388	  choice and suitable for most users). This will result in a "3GB/1GB"
1389	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1390	  space and the remaining part of the 4GB virtual memory space is used
1391	  by the kernel to permanently map as much physical memory as
1392	  possible.
1393
1394	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1395	  answer "4GB" here.
1396
1397	  If more than 4 Gigabytes is used then answer "64GB" here. This
1398	  selection turns Intel PAE (Physical Address Extension) mode on.
1399	  PAE implements 3-level paging on IA32 processors. PAE is fully
1400	  supported by Linux, PAE mode is implemented on all recent Intel
1401	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1402	  then the kernel will not boot on CPUs that don't support PAE!
1403
1404	  The actual amount of total physical memory will either be
1405	  auto detected or can be forced by using a kernel command line option
1406	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1407	  your boot loader (lilo or loadlin) about how to pass options to the
1408	  kernel at boot time.)
1409
1410	  If unsure, say "off".
1411
1412config HIGHMEM4G
1413	bool "4GB"
1414	help
1415	  Select this if you have a 32-bit processor and between 1 and 4
1416	  gigabytes of physical RAM.
1417
1418config HIGHMEM64G
1419	bool "64GB"
1420	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1421	select X86_PAE
1422	help
1423	  Select this if you have a 32-bit processor and more than 4
1424	  gigabytes of physical RAM.
1425
1426endchoice
1427
1428choice
1429	prompt "Memory split" if EXPERT
1430	default VMSPLIT_3G
1431	depends on X86_32
1432	help
1433	  Select the desired split between kernel and user memory.
1434
1435	  If the address range available to the kernel is less than the
1436	  physical memory installed, the remaining memory will be available
1437	  as "high memory". Accessing high memory is a little more costly
1438	  than low memory, as it needs to be mapped into the kernel first.
1439	  Note that increasing the kernel address space limits the range
1440	  available to user programs, making the address space there
1441	  tighter.  Selecting anything other than the default 3G/1G split
1442	  will also likely make your kernel incompatible with binary-only
1443	  kernel modules.
1444
1445	  If you are not absolutely sure what you are doing, leave this
1446	  option alone!
1447
1448	config VMSPLIT_3G
1449		bool "3G/1G user/kernel split"
1450	config VMSPLIT_3G_OPT
1451		depends on !X86_PAE
1452		bool "3G/1G user/kernel split (for full 1G low memory)"
1453	config VMSPLIT_2G
1454		bool "2G/2G user/kernel split"
1455	config VMSPLIT_2G_OPT
1456		depends on !X86_PAE
1457		bool "2G/2G user/kernel split (for full 2G low memory)"
1458	config VMSPLIT_1G
1459		bool "1G/3G user/kernel split"
1460endchoice
1461
1462config PAGE_OFFSET
1463	hex
1464	default 0xB0000000 if VMSPLIT_3G_OPT
1465	default 0x80000000 if VMSPLIT_2G
1466	default 0x78000000 if VMSPLIT_2G_OPT
1467	default 0x40000000 if VMSPLIT_1G
1468	default 0xC0000000
1469	depends on X86_32
1470
1471config HIGHMEM
1472	def_bool y
1473	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1474
1475config X86_PAE
1476	bool "PAE (Physical Address Extension) Support"
1477	depends on X86_32 && !HIGHMEM4G
1478	select PHYS_ADDR_T_64BIT
1479	select SWIOTLB
1480	help
1481	  PAE is required for NX support, and furthermore enables
1482	  larger swapspace support for non-overcommit purposes. It
1483	  has the cost of more pagetable lookup overhead, and also
1484	  consumes more pagetable space per process.
1485
1486config X86_5LEVEL
1487	bool "Enable 5-level page tables support"
1488	default y
1489	select DYNAMIC_MEMORY_LAYOUT
1490	select SPARSEMEM_VMEMMAP
1491	depends on X86_64
1492	help
1493	  5-level paging enables access to larger address space:
1494	  up to 128 PiB of virtual address space and 4 PiB of
1495	  physical address space.
1496
1497	  It will be supported by future Intel CPUs.
1498
1499	  A kernel with the option enabled can be booted on machines that
1500	  support 4- or 5-level paging.
1501
1502	  See Documentation/arch/x86/x86_64/5level-paging.rst for more
1503	  information.
1504
1505	  Say N if unsure.
1506
1507config X86_DIRECT_GBPAGES
1508	def_bool y
1509	depends on X86_64
1510	help
1511	  Certain kernel features effectively disable kernel
1512	  linear 1 GB mappings (even if the CPU otherwise
1513	  supports them), so don't confuse the user by printing
1514	  that we have them enabled.
1515
1516config X86_CPA_STATISTICS
1517	bool "Enable statistic for Change Page Attribute"
1518	depends on DEBUG_FS
1519	help
1520	  Expose statistics about the Change Page Attribute mechanism, which
1521	  helps to determine the effectiveness of preserving large and huge
1522	  page mappings when mapping protections are changed.
1523
1524config X86_MEM_ENCRYPT
1525	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1526	select DYNAMIC_PHYSICAL_MASK
1527	def_bool n
1528
1529config AMD_MEM_ENCRYPT
1530	bool "AMD Secure Memory Encryption (SME) support"
1531	depends on X86_64 && CPU_SUP_AMD
1532	depends on EFI_STUB
1533	select DMA_COHERENT_POOL
1534	select ARCH_USE_MEMREMAP_PROT
1535	select INSTRUCTION_DECODER
1536	select ARCH_HAS_CC_PLATFORM
1537	select X86_MEM_ENCRYPT
1538	select UNACCEPTED_MEMORY
1539	help
1540	  Say yes to enable support for the encryption of system memory.
1541	  This requires an AMD processor that supports Secure Memory
1542	  Encryption (SME).
1543
1544# Common NUMA Features
1545config NUMA
1546	bool "NUMA Memory Allocation and Scheduler Support"
1547	depends on SMP
1548	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1549	default y if X86_BIGSMP
1550	select USE_PERCPU_NUMA_NODE_ID
1551	help
1552	  Enable NUMA (Non-Uniform Memory Access) support.
1553
1554	  The kernel will try to allocate memory used by a CPU on the
1555	  local memory controller of the CPU and add some more
1556	  NUMA awareness to the kernel.
1557
1558	  For 64-bit this is recommended if the system is Intel Core i7
1559	  (or later), AMD Opteron, or EM64T NUMA.
1560
1561	  For 32-bit this is only needed if you boot a 32-bit
1562	  kernel on a 64-bit NUMA platform.
1563
1564	  Otherwise, you should say N.
1565
1566config AMD_NUMA
1567	def_bool y
1568	prompt "Old style AMD Opteron NUMA detection"
1569	depends on X86_64 && NUMA && PCI
1570	help
1571	  Enable AMD NUMA node topology detection.  You should say Y here if
1572	  you have a multi processor AMD system. This uses an old method to
1573	  read the NUMA configuration directly from the builtin Northbridge
1574	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1575	  which also takes priority if both are compiled in.
1576
1577config X86_64_ACPI_NUMA
1578	def_bool y
1579	prompt "ACPI NUMA detection"
1580	depends on X86_64 && NUMA && ACPI && PCI
1581	select ACPI_NUMA
1582	help
1583	  Enable ACPI SRAT based node topology detection.
1584
1585config NUMA_EMU
1586	bool "NUMA emulation"
1587	depends on NUMA
1588	help
1589	  Enable NUMA emulation. A flat machine will be split
1590	  into virtual nodes when booted with "numa=fake=N", where N is the
1591	  number of nodes. This is only useful for debugging.
1592
1593config NODES_SHIFT
1594	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1595	range 1 10
1596	default "10" if MAXSMP
1597	default "6" if X86_64
1598	default "3"
1599	depends on NUMA
1600	help
1601	  Specify the maximum number of NUMA Nodes available on the target
1602	  system.  Increases memory reserved to accommodate various tables.
1603
1604config ARCH_FLATMEM_ENABLE
1605	def_bool y
1606	depends on X86_32 && !NUMA
1607
1608config ARCH_SPARSEMEM_ENABLE
1609	def_bool y
1610	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1611	select SPARSEMEM_STATIC if X86_32
1612	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1613
1614config ARCH_SPARSEMEM_DEFAULT
1615	def_bool X86_64 || (NUMA && X86_32)
1616
1617config ARCH_SELECT_MEMORY_MODEL
1618	def_bool y
1619	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1620
1621config ARCH_MEMORY_PROBE
1622	bool "Enable sysfs memory/probe interface"
1623	depends on MEMORY_HOTPLUG
1624	help
1625	  This option enables a sysfs memory/probe interface for testing.
1626	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1627	  If you are unsure how to answer this question, answer N.
1628
1629config ARCH_PROC_KCORE_TEXT
1630	def_bool y
1631	depends on X86_64 && PROC_KCORE
1632
1633config ILLEGAL_POINTER_VALUE
1634	hex
1635	default 0 if X86_32
1636	default 0xdead000000000000 if X86_64
1637
1638config X86_PMEM_LEGACY_DEVICE
1639	bool
1640
1641config X86_PMEM_LEGACY
1642	tristate "Support non-standard NVDIMMs and ADR protected memory"
1643	depends on PHYS_ADDR_T_64BIT
1644	depends on BLK_DEV
1645	select X86_PMEM_LEGACY_DEVICE
1646	select NUMA_KEEP_MEMINFO if NUMA
1647	select LIBNVDIMM
1648	help
1649	  Treat memory marked using the non-standard e820 type of 12 as used
1650	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1651	  The kernel will offer these regions to the 'pmem' driver so
1652	  they can be used for persistent storage.
1653
1654	  Say Y if unsure.
1655
1656config HIGHPTE
1657	bool "Allocate 3rd-level pagetables from highmem"
1658	depends on HIGHMEM
1659	help
1660	  The VM uses one page table entry for each page of physical memory.
1661	  For systems with a lot of RAM, this can be wasteful of precious
1662	  low memory.  Setting this option will put user-space page table
1663	  entries in high memory.
1664
1665config X86_CHECK_BIOS_CORRUPTION
1666	bool "Check for low memory corruption"
1667	help
1668	  Periodically check for memory corruption in low memory, which
1669	  is suspected to be caused by BIOS.  Even when enabled in the
1670	  configuration, it is disabled at runtime.  Enable it by
1671	  setting "memory_corruption_check=1" on the kernel command
1672	  line.  By default it scans the low 64k of memory every 60
1673	  seconds; see the memory_corruption_check_size and
1674	  memory_corruption_check_period parameters in
1675	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1676
1677	  When enabled with the default parameters, this option has
1678	  almost no overhead, as it reserves a relatively small amount
1679	  of memory and scans it infrequently.  It both detects corruption
1680	  and prevents it from affecting the running system.
1681
1682	  It is, however, intended as a diagnostic tool; if repeatable
1683	  BIOS-originated corruption always affects the same memory,
1684	  you can use memmap= to prevent the kernel from using that
1685	  memory.
1686
1687config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1688	bool "Set the default setting of memory_corruption_check"
1689	depends on X86_CHECK_BIOS_CORRUPTION
1690	default y
1691	help
1692	  Set whether the default state of memory_corruption_check is
1693	  on or off.
1694
1695config MATH_EMULATION
1696	bool
1697	depends on MODIFY_LDT_SYSCALL
1698	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1699	help
1700	  Linux can emulate a math coprocessor (used for floating point
1701	  operations) if you don't have one. 486DX and Pentium processors have
1702	  a math coprocessor built in, 486SX and 386 do not, unless you added
1703	  a 487DX or 387, respectively. (The messages during boot time can
1704	  give you some hints here ["man dmesg"].) Everyone needs either a
1705	  coprocessor or this emulation.
1706
1707	  If you don't have a math coprocessor, you need to say Y here; if you
1708	  say Y here even though you have a coprocessor, the coprocessor will
1709	  be used nevertheless. (This behavior can be changed with the kernel
1710	  command line option "no387", which comes handy if your coprocessor
1711	  is broken. Try "man bootparam" or see the documentation of your boot
1712	  loader (lilo or loadlin) about how to pass options to the kernel at
1713	  boot time.) This means that it is a good idea to say Y here if you
1714	  intend to use this kernel on different machines.
1715
1716	  More information about the internals of the Linux math coprocessor
1717	  emulation can be found in <file:arch/x86/math-emu/README>.
1718
1719	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1720	  kernel, it won't hurt.
1721
1722config MTRR
1723	def_bool y
1724	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1725	help
1726	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1727	  the Memory Type Range Registers (MTRRs) may be used to control
1728	  processor access to memory ranges. This is most useful if you have
1729	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1730	  allows bus write transfers to be combined into a larger transfer
1731	  before bursting over the PCI/AGP bus. This can increase performance
1732	  of image write operations 2.5 times or more. Saying Y here creates a
1733	  /proc/mtrr file which may be used to manipulate your processor's
1734	  MTRRs. Typically the X server should use this.
1735
1736	  This code has a reasonably generic interface so that similar
1737	  control registers on other processors can be easily supported
1738	  as well:
1739
1740	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1741	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1742	  these, the ARRs are used to emulate the MTRRs.
1743	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1744	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1745	  write-combining. All of these processors are supported by this code
1746	  and it makes sense to say Y here if you have one of them.
1747
1748	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1749	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1750	  can lead to all sorts of problems, so it's good to say Y here.
1751
1752	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1753	  just add about 9 KB to your kernel.
1754
1755	  See <file:Documentation/arch/x86/mtrr.rst> for more information.
1756
1757config MTRR_SANITIZER
1758	def_bool y
1759	prompt "MTRR cleanup support"
1760	depends on MTRR
1761	help
1762	  Convert MTRR layout from continuous to discrete, so X drivers can
1763	  add writeback entries.
1764
1765	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1766	  The largest mtrr entry size for a continuous block can be set with
1767	  mtrr_chunk_size.
1768
1769	  If unsure, say Y.
1770
1771config MTRR_SANITIZER_ENABLE_DEFAULT
1772	int "MTRR cleanup enable value (0-1)"
1773	range 0 1
1774	default "0"
1775	depends on MTRR_SANITIZER
1776	help
1777	  Enable mtrr cleanup default value
1778
1779config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1780	int "MTRR cleanup spare reg num (0-7)"
1781	range 0 7
1782	default "1"
1783	depends on MTRR_SANITIZER
1784	help
1785	  mtrr cleanup spare entries default, it can be changed via
1786	  mtrr_spare_reg_nr=N on the kernel command line.
1787
1788config X86_PAT
1789	def_bool y
1790	prompt "x86 PAT support" if EXPERT
1791	depends on MTRR
1792	help
1793	  Use PAT attributes to setup page level cache control.
1794
1795	  PATs are the modern equivalents of MTRRs and are much more
1796	  flexible than MTRRs.
1797
1798	  Say N here if you see bootup problems (boot crash, boot hang,
1799	  spontaneous reboots) or a non-working video driver.
1800
1801	  If unsure, say Y.
1802
1803config ARCH_USES_PG_UNCACHED
1804	def_bool y
1805	depends on X86_PAT
1806
1807config X86_UMIP
1808	def_bool y
1809	prompt "User Mode Instruction Prevention" if EXPERT
1810	help
1811	  User Mode Instruction Prevention (UMIP) is a security feature in
1812	  some x86 processors. If enabled, a general protection fault is
1813	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1814	  executed in user mode. These instructions unnecessarily expose
1815	  information about the hardware state.
1816
1817	  The vast majority of applications do not use these instructions.
1818	  For the very few that do, software emulation is provided in
1819	  specific cases in protected and virtual-8086 modes. Emulated
1820	  results are dummy.
1821
1822config CC_HAS_IBT
1823	# GCC >= 9 and binutils >= 2.29
1824	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1825	# Clang/LLVM >= 14
1826	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1827	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1828	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1829		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1830		  $(as-instr,endbr64)
1831
1832config X86_CET
1833	def_bool n
1834	help
1835	  CET features configured (Shadow stack or IBT)
1836
1837config X86_KERNEL_IBT
1838	prompt "Indirect Branch Tracking"
1839	def_bool y
1840	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1841	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1842	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1843	select OBJTOOL
1844	select X86_CET
1845	help
1846	  Build the kernel with support for Indirect Branch Tracking, a
1847	  hardware support course-grain forward-edge Control Flow Integrity
1848	  protection. It enforces that all indirect calls must land on
1849	  an ENDBR instruction, as such, the compiler will instrument the
1850	  code with them to make this happen.
1851
1852	  In addition to building the kernel with IBT, seal all functions that
1853	  are not indirect call targets, avoiding them ever becoming one.
1854
1855	  This requires LTO like objtool runs and will slow down the build. It
1856	  does significantly reduce the number of ENDBR instructions in the
1857	  kernel image.
1858
1859config X86_INTEL_MEMORY_PROTECTION_KEYS
1860	prompt "Memory Protection Keys"
1861	def_bool y
1862	# Note: only available in 64-bit mode
1863	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1864	select ARCH_USES_HIGH_VMA_FLAGS
1865	select ARCH_HAS_PKEYS
1866	help
1867	  Memory Protection Keys provides a mechanism for enforcing
1868	  page-based protections, but without requiring modification of the
1869	  page tables when an application changes protection domains.
1870
1871	  For details, see Documentation/core-api/protection-keys.rst
1872
1873	  If unsure, say y.
1874
1875choice
1876	prompt "TSX enable mode"
1877	depends on CPU_SUP_INTEL
1878	default X86_INTEL_TSX_MODE_OFF
1879	help
1880	  Intel's TSX (Transactional Synchronization Extensions) feature
1881	  allows to optimize locking protocols through lock elision which
1882	  can lead to a noticeable performance boost.
1883
1884	  On the other hand it has been shown that TSX can be exploited
1885	  to form side channel attacks (e.g. TAA) and chances are there
1886	  will be more of those attacks discovered in the future.
1887
1888	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1889	  might override this decision by tsx=on the command line parameter.
1890	  Even with TSX enabled, the kernel will attempt to enable the best
1891	  possible TAA mitigation setting depending on the microcode available
1892	  for the particular machine.
1893
1894	  This option allows to set the default tsx mode between tsx=on, =off
1895	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1896	  details.
1897
1898	  Say off if not sure, auto if TSX is in use but it should be used on safe
1899	  platforms or on if TSX is in use and the security aspect of tsx is not
1900	  relevant.
1901
1902config X86_INTEL_TSX_MODE_OFF
1903	bool "off"
1904	help
1905	  TSX is disabled if possible - equals to tsx=off command line parameter.
1906
1907config X86_INTEL_TSX_MODE_ON
1908	bool "on"
1909	help
1910	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1911	  line parameter.
1912
1913config X86_INTEL_TSX_MODE_AUTO
1914	bool "auto"
1915	help
1916	  TSX is enabled on TSX capable HW that is believed to be safe against
1917	  side channel attacks- equals the tsx=auto command line parameter.
1918endchoice
1919
1920config X86_SGX
1921	bool "Software Guard eXtensions (SGX)"
1922	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1923	depends on CRYPTO=y
1924	depends on CRYPTO_SHA256=y
1925	select MMU_NOTIFIER
1926	select NUMA_KEEP_MEMINFO if NUMA
1927	select XARRAY_MULTI
1928	help
1929	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1930	  that can be used by applications to set aside private regions of code
1931	  and data, referred to as enclaves. An enclave's private memory can
1932	  only be accessed by code running within the enclave. Accesses from
1933	  outside the enclave, including other enclaves, are disallowed by
1934	  hardware.
1935
1936	  If unsure, say N.
1937
1938config X86_USER_SHADOW_STACK
1939	bool "X86 userspace shadow stack"
1940	depends on AS_WRUSS
1941	depends on X86_64
1942	select ARCH_USES_HIGH_VMA_FLAGS
1943	select X86_CET
1944	help
1945	  Shadow stack protection is a hardware feature that detects function
1946	  return address corruption.  This helps mitigate ROP attacks.
1947	  Applications must be enabled to use it, and old userspace does not
1948	  get protection "for free".
1949
1950	  CPUs supporting shadow stacks were first released in 2020.
1951
1952	  See Documentation/arch/x86/shstk.rst for more information.
1953
1954	  If unsure, say N.
1955
1956config EFI
1957	bool "EFI runtime service support"
1958	depends on ACPI
1959	select UCS2_STRING
1960	select EFI_RUNTIME_WRAPPERS
1961	select ARCH_USE_MEMREMAP_PROT
1962	select EFI_RUNTIME_MAP if KEXEC_CORE
1963	help
1964	  This enables the kernel to use EFI runtime services that are
1965	  available (such as the EFI variable services).
1966
1967	  This option is only useful on systems that have EFI firmware.
1968	  In addition, you should use the latest ELILO loader available
1969	  at <http://elilo.sourceforge.net> in order to take advantage
1970	  of EFI runtime services. However, even with this option, the
1971	  resultant kernel should continue to boot on existing non-EFI
1972	  platforms.
1973
1974config EFI_STUB
1975	bool "EFI stub support"
1976	depends on EFI
1977	select RELOCATABLE
1978	help
1979	  This kernel feature allows a bzImage to be loaded directly
1980	  by EFI firmware without the use of a bootloader.
1981
1982	  See Documentation/admin-guide/efi-stub.rst for more information.
1983
1984config EFI_HANDOVER_PROTOCOL
1985	bool "EFI handover protocol (DEPRECATED)"
1986	depends on EFI_STUB
1987	default y
1988	help
1989	  Select this in order to include support for the deprecated EFI
1990	  handover protocol, which defines alternative entry points into the
1991	  EFI stub.  This is a practice that has no basis in the UEFI
1992	  specification, and requires a priori knowledge on the part of the
1993	  bootloader about Linux/x86 specific ways of passing the command line
1994	  and initrd, and where in memory those assets may be loaded.
1995
1996	  If in doubt, say Y. Even though the corresponding support is not
1997	  present in upstream GRUB or other bootloaders, most distros build
1998	  GRUB with numerous downstream patches applied, and may rely on the
1999	  handover protocol as as result.
2000
2001config EFI_MIXED
2002	bool "EFI mixed-mode support"
2003	depends on EFI_STUB && X86_64
2004	help
2005	  Enabling this feature allows a 64-bit kernel to be booted
2006	  on a 32-bit firmware, provided that your CPU supports 64-bit
2007	  mode.
2008
2009	  Note that it is not possible to boot a mixed-mode enabled
2010	  kernel via the EFI boot stub - a bootloader that supports
2011	  the EFI handover protocol must be used.
2012
2013	  If unsure, say N.
2014
2015config EFI_FAKE_MEMMAP
2016	bool "Enable EFI fake memory map"
2017	depends on EFI
2018	help
2019	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2020	  this parameter, you can add arbitrary attribute to specific memory
2021	  range by updating original (firmware provided) EFI memmap.  This is
2022	  useful for debugging of EFI memmap related feature, e.g., Address
2023	  Range Mirroring feature.
2024
2025config EFI_MAX_FAKE_MEM
2026	int "maximum allowable number of ranges in efi_fake_mem boot option"
2027	depends on EFI_FAKE_MEMMAP
2028	range 1 128
2029	default 8
2030	help
2031	  Maximum allowable number of ranges in efi_fake_mem boot option.
2032	  Ranges can be set up to this value using comma-separated list.
2033	  The default value is 8.
2034
2035config EFI_RUNTIME_MAP
2036	bool "Export EFI runtime maps to sysfs" if EXPERT
2037	depends on EFI
2038	help
2039	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2040	  That memory map is required by the 2nd kernel to set up EFI virtual
2041	  mappings after kexec, but can also be used for debugging purposes.
2042
2043	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2044
2045source "kernel/Kconfig.hz"
2046
2047config ARCH_SUPPORTS_KEXEC
2048	def_bool y
2049
2050config ARCH_SUPPORTS_KEXEC_FILE
2051	def_bool X86_64
2052
2053config ARCH_SELECTS_KEXEC_FILE
2054	def_bool y
2055	depends on KEXEC_FILE
2056	select HAVE_IMA_KEXEC if IMA
2057
2058config ARCH_SUPPORTS_KEXEC_PURGATORY
2059	def_bool y
2060
2061config ARCH_SUPPORTS_KEXEC_SIG
2062	def_bool y
2063
2064config ARCH_SUPPORTS_KEXEC_SIG_FORCE
2065	def_bool y
2066
2067config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
2068	def_bool y
2069
2070config ARCH_SUPPORTS_KEXEC_JUMP
2071	def_bool y
2072
2073config ARCH_SUPPORTS_CRASH_DUMP
2074	def_bool X86_64 || (X86_32 && HIGHMEM)
2075
2076config ARCH_SUPPORTS_CRASH_HOTPLUG
2077	def_bool y
2078
2079config PHYSICAL_START
2080	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2081	default "0x1000000"
2082	help
2083	  This gives the physical address where the kernel is loaded.
2084
2085	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2086	  bzImage will decompress itself to above physical address and
2087	  run from there. Otherwise, bzImage will run from the address where
2088	  it has been loaded by the boot loader and will ignore above physical
2089	  address.
2090
2091	  In normal kdump cases one does not have to set/change this option
2092	  as now bzImage can be compiled as a completely relocatable image
2093	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2094	  address. This option is mainly useful for the folks who don't want
2095	  to use a bzImage for capturing the crash dump and want to use a
2096	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2097	  to be specifically compiled to run from a specific memory area
2098	  (normally a reserved region) and this option comes handy.
2099
2100	  So if you are using bzImage for capturing the crash dump,
2101	  leave the value here unchanged to 0x1000000 and set
2102	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2103	  for capturing the crash dump change this value to start of
2104	  the reserved region.  In other words, it can be set based on
2105	  the "X" value as specified in the "crashkernel=YM@XM"
2106	  command line boot parameter passed to the panic-ed
2107	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2108	  for more details about crash dumps.
2109
2110	  Usage of bzImage for capturing the crash dump is recommended as
2111	  one does not have to build two kernels. Same kernel can be used
2112	  as production kernel and capture kernel. Above option should have
2113	  gone away after relocatable bzImage support is introduced. But it
2114	  is present because there are users out there who continue to use
2115	  vmlinux for dump capture. This option should go away down the
2116	  line.
2117
2118	  Don't change this unless you know what you are doing.
2119
2120config RELOCATABLE
2121	bool "Build a relocatable kernel"
2122	default y
2123	help
2124	  This builds a kernel image that retains relocation information
2125	  so it can be loaded someplace besides the default 1MB.
2126	  The relocations tend to make the kernel binary about 10% larger,
2127	  but are discarded at runtime.
2128
2129	  One use is for the kexec on panic case where the recovery kernel
2130	  must live at a different physical address than the primary
2131	  kernel.
2132
2133	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2134	  it has been loaded at and the compile time physical address
2135	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2136
2137config RANDOMIZE_BASE
2138	bool "Randomize the address of the kernel image (KASLR)"
2139	depends on RELOCATABLE
2140	default y
2141	help
2142	  In support of Kernel Address Space Layout Randomization (KASLR),
2143	  this randomizes the physical address at which the kernel image
2144	  is decompressed and the virtual address where the kernel
2145	  image is mapped, as a security feature that deters exploit
2146	  attempts relying on knowledge of the location of kernel
2147	  code internals.
2148
2149	  On 64-bit, the kernel physical and virtual addresses are
2150	  randomized separately. The physical address will be anywhere
2151	  between 16MB and the top of physical memory (up to 64TB). The
2152	  virtual address will be randomized from 16MB up to 1GB (9 bits
2153	  of entropy). Note that this also reduces the memory space
2154	  available to kernel modules from 1.5GB to 1GB.
2155
2156	  On 32-bit, the kernel physical and virtual addresses are
2157	  randomized together. They will be randomized from 16MB up to
2158	  512MB (8 bits of entropy).
2159
2160	  Entropy is generated using the RDRAND instruction if it is
2161	  supported. If RDTSC is supported, its value is mixed into
2162	  the entropy pool as well. If neither RDRAND nor RDTSC are
2163	  supported, then entropy is read from the i8254 timer. The
2164	  usable entropy is limited by the kernel being built using
2165	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2166	  minimum of 2MB. As a result, only 10 bits of entropy are
2167	  theoretically possible, but the implementations are further
2168	  limited due to memory layouts.
2169
2170	  If unsure, say Y.
2171
2172# Relocation on x86 needs some additional build support
2173config X86_NEED_RELOCS
2174	def_bool y
2175	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2176
2177config PHYSICAL_ALIGN
2178	hex "Alignment value to which kernel should be aligned"
2179	default "0x200000"
2180	range 0x2000 0x1000000 if X86_32
2181	range 0x200000 0x1000000 if X86_64
2182	help
2183	  This value puts the alignment restrictions on physical address
2184	  where kernel is loaded and run from. Kernel is compiled for an
2185	  address which meets above alignment restriction.
2186
2187	  If bootloader loads the kernel at a non-aligned address and
2188	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2189	  address aligned to above value and run from there.
2190
2191	  If bootloader loads the kernel at a non-aligned address and
2192	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2193	  load address and decompress itself to the address it has been
2194	  compiled for and run from there. The address for which kernel is
2195	  compiled already meets above alignment restrictions. Hence the
2196	  end result is that kernel runs from a physical address meeting
2197	  above alignment restrictions.
2198
2199	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2200	  this value must be a multiple of 0x200000.
2201
2202	  Don't change this unless you know what you are doing.
2203
2204config DYNAMIC_MEMORY_LAYOUT
2205	bool
2206	help
2207	  This option makes base addresses of vmalloc and vmemmap as well as
2208	  __PAGE_OFFSET movable during boot.
2209
2210config RANDOMIZE_MEMORY
2211	bool "Randomize the kernel memory sections"
2212	depends on X86_64
2213	depends on RANDOMIZE_BASE
2214	select DYNAMIC_MEMORY_LAYOUT
2215	default RANDOMIZE_BASE
2216	help
2217	  Randomizes the base virtual address of kernel memory sections
2218	  (physical memory mapping, vmalloc & vmemmap). This security feature
2219	  makes exploits relying on predictable memory locations less reliable.
2220
2221	  The order of allocations remains unchanged. Entropy is generated in
2222	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2223	  configuration have in average 30,000 different possible virtual
2224	  addresses for each memory section.
2225
2226	  If unsure, say Y.
2227
2228config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2229	hex "Physical memory mapping padding" if EXPERT
2230	depends on RANDOMIZE_MEMORY
2231	default "0xa" if MEMORY_HOTPLUG
2232	default "0x0"
2233	range 0x1 0x40 if MEMORY_HOTPLUG
2234	range 0x0 0x40
2235	help
2236	  Define the padding in terabytes added to the existing physical
2237	  memory size during kernel memory randomization. It is useful
2238	  for memory hotplug support but reduces the entropy available for
2239	  address randomization.
2240
2241	  If unsure, leave at the default value.
2242
2243config ADDRESS_MASKING
2244	bool "Linear Address Masking support"
2245	depends on X86_64
2246	depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS
2247	help
2248	  Linear Address Masking (LAM) modifies the checking that is applied
2249	  to 64-bit linear addresses, allowing software to use of the
2250	  untranslated address bits for metadata.
2251
2252	  The capability can be used for efficient address sanitizers (ASAN)
2253	  implementation and for optimizations in JITs.
2254
2255config HOTPLUG_CPU
2256	def_bool y
2257	depends on SMP
2258
2259config COMPAT_VDSO
2260	def_bool n
2261	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2262	depends on COMPAT_32
2263	help
2264	  Certain buggy versions of glibc will crash if they are
2265	  presented with a 32-bit vDSO that is not mapped at the address
2266	  indicated in its segment table.
2267
2268	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2269	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2270	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2271	  the only released version with the bug, but OpenSUSE 9
2272	  contains a buggy "glibc 2.3.2".
2273
2274	  The symptom of the bug is that everything crashes on startup, saying:
2275	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2276
2277	  Saying Y here changes the default value of the vdso32 boot
2278	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2279	  This works around the glibc bug but hurts performance.
2280
2281	  If unsure, say N: if you are compiling your own kernel, you
2282	  are unlikely to be using a buggy version of glibc.
2283
2284choice
2285	prompt "vsyscall table for legacy applications"
2286	depends on X86_64
2287	default LEGACY_VSYSCALL_XONLY
2288	help
2289	  Legacy user code that does not know how to find the vDSO expects
2290	  to be able to issue three syscalls by calling fixed addresses in
2291	  kernel space. Since this location is not randomized with ASLR,
2292	  it can be used to assist security vulnerability exploitation.
2293
2294	  This setting can be changed at boot time via the kernel command
2295	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2296	  is deprecated and can only be enabled using the kernel command
2297	  line.
2298
2299	  On a system with recent enough glibc (2.14 or newer) and no
2300	  static binaries, you can say None without a performance penalty
2301	  to improve security.
2302
2303	  If unsure, select "Emulate execution only".
2304
2305	config LEGACY_VSYSCALL_XONLY
2306		bool "Emulate execution only"
2307		help
2308		  The kernel traps and emulates calls into the fixed vsyscall
2309		  address mapping and does not allow reads.  This
2310		  configuration is recommended when userspace might use the
2311		  legacy vsyscall area but support for legacy binary
2312		  instrumentation of legacy code is not needed.  It mitigates
2313		  certain uses of the vsyscall area as an ASLR-bypassing
2314		  buffer.
2315
2316	config LEGACY_VSYSCALL_NONE
2317		bool "None"
2318		help
2319		  There will be no vsyscall mapping at all. This will
2320		  eliminate any risk of ASLR bypass due to the vsyscall
2321		  fixed address mapping. Attempts to use the vsyscalls
2322		  will be reported to dmesg, so that either old or
2323		  malicious userspace programs can be identified.
2324
2325endchoice
2326
2327config CMDLINE_BOOL
2328	bool "Built-in kernel command line"
2329	help
2330	  Allow for specifying boot arguments to the kernel at
2331	  build time.  On some systems (e.g. embedded ones), it is
2332	  necessary or convenient to provide some or all of the
2333	  kernel boot arguments with the kernel itself (that is,
2334	  to not rely on the boot loader to provide them.)
2335
2336	  To compile command line arguments into the kernel,
2337	  set this option to 'Y', then fill in the
2338	  boot arguments in CONFIG_CMDLINE.
2339
2340	  Systems with fully functional boot loaders (i.e. non-embedded)
2341	  should leave this option set to 'N'.
2342
2343config CMDLINE
2344	string "Built-in kernel command string"
2345	depends on CMDLINE_BOOL
2346	default ""
2347	help
2348	  Enter arguments here that should be compiled into the kernel
2349	  image and used at boot time.  If the boot loader provides a
2350	  command line at boot time, it is appended to this string to
2351	  form the full kernel command line, when the system boots.
2352
2353	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2354	  change this behavior.
2355
2356	  In most cases, the command line (whether built-in or provided
2357	  by the boot loader) should specify the device for the root
2358	  file system.
2359
2360config CMDLINE_OVERRIDE
2361	bool "Built-in command line overrides boot loader arguments"
2362	depends on CMDLINE_BOOL && CMDLINE != ""
2363	help
2364	  Set this option to 'Y' to have the kernel ignore the boot loader
2365	  command line, and use ONLY the built-in command line.
2366
2367	  This is used to work around broken boot loaders.  This should
2368	  be set to 'N' under normal conditions.
2369
2370config MODIFY_LDT_SYSCALL
2371	bool "Enable the LDT (local descriptor table)" if EXPERT
2372	default y
2373	help
2374	  Linux can allow user programs to install a per-process x86
2375	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2376	  call.  This is required to run 16-bit or segmented code such as
2377	  DOSEMU or some Wine programs.  It is also used by some very old
2378	  threading libraries.
2379
2380	  Enabling this feature adds a small amount of overhead to
2381	  context switches and increases the low-level kernel attack
2382	  surface.  Disabling it removes the modify_ldt(2) system call.
2383
2384	  Saying 'N' here may make sense for embedded or server kernels.
2385
2386config STRICT_SIGALTSTACK_SIZE
2387	bool "Enforce strict size checking for sigaltstack"
2388	depends on DYNAMIC_SIGFRAME
2389	help
2390	  For historical reasons MINSIGSTKSZ is a constant which became
2391	  already too small with AVX512 support. Add a mechanism to
2392	  enforce strict checking of the sigaltstack size against the
2393	  real size of the FPU frame. This option enables the check
2394	  by default. It can also be controlled via the kernel command
2395	  line option 'strict_sas_size' independent of this config
2396	  switch. Enabling it might break existing applications which
2397	  allocate a too small sigaltstack but 'work' because they
2398	  never get a signal delivered.
2399
2400	  Say 'N' unless you want to really enforce this check.
2401
2402source "kernel/livepatch/Kconfig"
2403
2404endmenu
2405
2406config CC_HAS_SLS
2407	def_bool $(cc-option,-mharden-sls=all)
2408
2409config CC_HAS_RETURN_THUNK
2410	def_bool $(cc-option,-mfunction-return=thunk-extern)
2411
2412config CC_HAS_ENTRY_PADDING
2413	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2414
2415config FUNCTION_PADDING_CFI
2416	int
2417	default 59 if FUNCTION_ALIGNMENT_64B
2418	default 27 if FUNCTION_ALIGNMENT_32B
2419	default 11 if FUNCTION_ALIGNMENT_16B
2420	default  3 if FUNCTION_ALIGNMENT_8B
2421	default  0
2422
2423# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2424# except Kconfig can't do arithmetic :/
2425config FUNCTION_PADDING_BYTES
2426	int
2427	default FUNCTION_PADDING_CFI if CFI_CLANG
2428	default FUNCTION_ALIGNMENT
2429
2430config CALL_PADDING
2431	def_bool n
2432	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2433	select FUNCTION_ALIGNMENT_16B
2434
2435config FINEIBT
2436	def_bool y
2437	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2438	select CALL_PADDING
2439
2440config HAVE_CALL_THUNKS
2441	def_bool y
2442	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2443
2444config CALL_THUNKS
2445	def_bool n
2446	select CALL_PADDING
2447
2448config PREFIX_SYMBOLS
2449	def_bool y
2450	depends on CALL_PADDING && !CFI_CLANG
2451
2452menuconfig CPU_MITIGATIONS
2453	bool "Mitigations for CPU vulnerabilities"
2454	default y
2455	help
2456	  Say Y here to enable options which enable mitigations for hardware
2457	  vulnerabilities (usually related to speculative execution).
2458	  Mitigations can be disabled or restricted to SMT systems at runtime
2459	  via the "mitigations" kernel parameter.
2460
2461	  If you say N, all mitigations will be disabled.  This CANNOT be
2462	  overridden at runtime.
2463
2464	  Say 'Y', unless you really know what you are doing.
2465
2466if CPU_MITIGATIONS
2467
2468config PAGE_TABLE_ISOLATION
2469	bool "Remove the kernel mapping in user mode"
2470	default y
2471	depends on (X86_64 || X86_PAE)
2472	help
2473	  This feature reduces the number of hardware side channels by
2474	  ensuring that the majority of kernel addresses are not mapped
2475	  into userspace.
2476
2477	  See Documentation/arch/x86/pti.rst for more details.
2478
2479config RETPOLINE
2480	bool "Avoid speculative indirect branches in kernel"
2481	select OBJTOOL if HAVE_OBJTOOL
2482	default y
2483	help
2484	  Compile kernel with the retpoline compiler options to guard against
2485	  kernel-to-user data leaks by avoiding speculative indirect
2486	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2487	  support for full protection. The kernel may run slower.
2488
2489config RETHUNK
2490	bool "Enable return-thunks"
2491	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2492	select OBJTOOL if HAVE_OBJTOOL
2493	default y if X86_64
2494	help
2495	  Compile the kernel with the return-thunks compiler option to guard
2496	  against kernel-to-user data leaks by avoiding return speculation.
2497	  Requires a compiler with -mfunction-return=thunk-extern
2498	  support for full protection. The kernel may run slower.
2499
2500config CPU_UNRET_ENTRY
2501	bool "Enable UNRET on kernel entry"
2502	depends on CPU_SUP_AMD && RETHUNK && X86_64
2503	default y
2504	help
2505	  Compile the kernel with support for the retbleed=unret mitigation.
2506
2507config CALL_DEPTH_TRACKING
2508	bool "Mitigate RSB underflow with call depth tracking"
2509	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2510	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2511	select CALL_THUNKS
2512	default y
2513	help
2514	  Compile the kernel with call depth tracking to mitigate the Intel
2515	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2516	  mitigation is off by default and needs to be enabled on the
2517	  kernel command line via the retbleed=stuff option. For
2518	  non-affected systems the overhead of this option is marginal as
2519	  the call depth tracking is using run-time generated call thunks
2520	  in a compiler generated padding area and call patching. This
2521	  increases text size by ~5%. For non affected systems this space
2522	  is unused. On affected SKL systems this results in a significant
2523	  performance gain over the IBRS mitigation.
2524
2525config CALL_THUNKS_DEBUG
2526	bool "Enable call thunks and call depth tracking debugging"
2527	depends on CALL_DEPTH_TRACKING
2528	select FUNCTION_ALIGNMENT_32B
2529	default n
2530	help
2531	  Enable call/ret counters for imbalance detection and build in
2532	  a noisy dmesg about callthunks generation and call patching for
2533	  trouble shooting. The debug prints need to be enabled on the
2534	  kernel command line with 'debug-callthunks'.
2535	  Only enable this when you are debugging call thunks as this
2536	  creates a noticeable runtime overhead. If unsure say N.
2537
2538config CPU_IBPB_ENTRY
2539	bool "Enable IBPB on kernel entry"
2540	depends on CPU_SUP_AMD && X86_64
2541	default y
2542	help
2543	  Compile the kernel with support for the retbleed=ibpb and
2544	  spec_rstack_overflow={ibpb,ibpb-vmexit} mitigations.
2545
2546config CPU_IBRS_ENTRY
2547	bool "Enable IBRS on kernel entry"
2548	depends on CPU_SUP_INTEL && X86_64
2549	default y
2550	help
2551	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2552	  This mitigates both spectre_v2 and retbleed at great cost to
2553	  performance.
2554
2555config CPU_SRSO
2556	bool "Mitigate speculative RAS overflow on AMD"
2557	depends on CPU_SUP_AMD && X86_64 && RETHUNK
2558	default y
2559	help
2560	  Enable the SRSO mitigation needed on AMD Zen1-4 machines.
2561
2562config SLS
2563	bool "Mitigate Straight-Line-Speculation"
2564	depends on CC_HAS_SLS && X86_64
2565	select OBJTOOL if HAVE_OBJTOOL
2566	default n
2567	help
2568	  Compile the kernel with straight-line-speculation options to guard
2569	  against straight line speculation. The kernel image might be slightly
2570	  larger.
2571
2572config GDS_FORCE_MITIGATION
2573	bool "Force GDS Mitigation"
2574	depends on CPU_SUP_INTEL
2575	default n
2576	help
2577	  Gather Data Sampling (GDS) is a hardware vulnerability which allows
2578	  unprivileged speculative access to data which was previously stored in
2579	  vector registers.
2580
2581	  This option is equivalent to setting gather_data_sampling=force on the
2582	  command line. The microcode mitigation is used if present, otherwise
2583	  AVX is disabled as a mitigation. On affected systems that are missing
2584	  the microcode any userspace code that unconditionally uses AVX will
2585	  break with this option set.
2586
2587	  Setting this option on systems not vulnerable to GDS has no effect.
2588
2589	  If in doubt, say N.
2590
2591config MITIGATION_RFDS
2592	bool "RFDS Mitigation"
2593	depends on CPU_SUP_INTEL
2594	default y
2595	help
2596	  Enable mitigation for Register File Data Sampling (RFDS) by default.
2597	  RFDS is a hardware vulnerability which affects Intel Atom CPUs. It
2598	  allows unprivileged speculative access to stale data previously
2599	  stored in floating point, vector and integer registers.
2600	  See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst>
2601
2602config MITIGATION_SPECTRE_BHI
2603	bool "Mitigate Spectre-BHB (Branch History Injection)"
2604	depends on CPU_SUP_INTEL
2605	default y
2606	help
2607	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
2608	  where the branch history buffer is poisoned to speculatively steer
2609	  indirect branches.
2610	  See <file:Documentation/admin-guide/hw-vuln/spectre.rst>
2611
2612endif
2613
2614config ARCH_HAS_ADD_PAGES
2615	def_bool y
2616	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2617
2618menu "Power management and ACPI options"
2619
2620config ARCH_HIBERNATION_HEADER
2621	def_bool y
2622	depends on HIBERNATION
2623
2624source "kernel/power/Kconfig"
2625
2626source "drivers/acpi/Kconfig"
2627
2628config X86_APM_BOOT
2629	def_bool y
2630	depends on APM
2631
2632menuconfig APM
2633	tristate "APM (Advanced Power Management) BIOS support"
2634	depends on X86_32 && PM_SLEEP
2635	help
2636	  APM is a BIOS specification for saving power using several different
2637	  techniques. This is mostly useful for battery powered laptops with
2638	  APM compliant BIOSes. If you say Y here, the system time will be
2639	  reset after a RESUME operation, the /proc/apm device will provide
2640	  battery status information, and user-space programs will receive
2641	  notification of APM "events" (e.g. battery status change).
2642
2643	  If you select "Y" here, you can disable actual use of the APM
2644	  BIOS by passing the "apm=off" option to the kernel at boot time.
2645
2646	  Note that the APM support is almost completely disabled for
2647	  machines with more than one CPU.
2648
2649	  In order to use APM, you will need supporting software. For location
2650	  and more information, read <file:Documentation/power/apm-acpi.rst>
2651	  and the Battery Powered Linux mini-HOWTO, available from
2652	  <http://www.tldp.org/docs.html#howto>.
2653
2654	  This driver does not spin down disk drives (see the hdparm(8)
2655	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2656	  VESA-compliant "green" monitors.
2657
2658	  This driver does not support the TI 4000M TravelMate and the ACER
2659	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2660	  desktop machines also don't have compliant BIOSes, and this driver
2661	  may cause those machines to panic during the boot phase.
2662
2663	  Generally, if you don't have a battery in your machine, there isn't
2664	  much point in using this driver and you should say N. If you get
2665	  random kernel OOPSes or reboots that don't seem to be related to
2666	  anything, try disabling/enabling this option (or disabling/enabling
2667	  APM in your BIOS).
2668
2669	  Some other things you should try when experiencing seemingly random,
2670	  "weird" problems:
2671
2672	  1) make sure that you have enough swap space and that it is
2673	  enabled.
2674	  2) pass the "idle=poll" option to the kernel
2675	  3) switch on floating point emulation in the kernel and pass
2676	  the "no387" option to the kernel
2677	  4) pass the "floppy=nodma" option to the kernel
2678	  5) pass the "mem=4M" option to the kernel (thereby disabling
2679	  all but the first 4 MB of RAM)
2680	  6) make sure that the CPU is not over clocked.
2681	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2682	  8) disable the cache from your BIOS settings
2683	  9) install a fan for the video card or exchange video RAM
2684	  10) install a better fan for the CPU
2685	  11) exchange RAM chips
2686	  12) exchange the motherboard.
2687
2688	  To compile this driver as a module, choose M here: the
2689	  module will be called apm.
2690
2691if APM
2692
2693config APM_IGNORE_USER_SUSPEND
2694	bool "Ignore USER SUSPEND"
2695	help
2696	  This option will ignore USER SUSPEND requests. On machines with a
2697	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2698	  series notebooks, it is necessary to say Y because of a BIOS bug.
2699
2700config APM_DO_ENABLE
2701	bool "Enable PM at boot time"
2702	help
2703	  Enable APM features at boot time. From page 36 of the APM BIOS
2704	  specification: "When disabled, the APM BIOS does not automatically
2705	  power manage devices, enter the Standby State, enter the Suspend
2706	  State, or take power saving steps in response to CPU Idle calls."
2707	  This driver will make CPU Idle calls when Linux is idle (unless this
2708	  feature is turned off -- see "Do CPU IDLE calls", below). This
2709	  should always save battery power, but more complicated APM features
2710	  will be dependent on your BIOS implementation. You may need to turn
2711	  this option off if your computer hangs at boot time when using APM
2712	  support, or if it beeps continuously instead of suspending. Turn
2713	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2714	  T400CDT. This is off by default since most machines do fine without
2715	  this feature.
2716
2717config APM_CPU_IDLE
2718	depends on CPU_IDLE
2719	bool "Make CPU Idle calls when idle"
2720	help
2721	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2722	  On some machines, this can activate improved power savings, such as
2723	  a slowed CPU clock rate, when the machine is idle. These idle calls
2724	  are made after the idle loop has run for some length of time (e.g.,
2725	  333 mS). On some machines, this will cause a hang at boot time or
2726	  whenever the CPU becomes idle. (On machines with more than one CPU,
2727	  this option does nothing.)
2728
2729config APM_DISPLAY_BLANK
2730	bool "Enable console blanking using APM"
2731	help
2732	  Enable console blanking using the APM. Some laptops can use this to
2733	  turn off the LCD backlight when the screen blanker of the Linux
2734	  virtual console blanks the screen. Note that this is only used by
2735	  the virtual console screen blanker, and won't turn off the backlight
2736	  when using the X Window system. This also doesn't have anything to
2737	  do with your VESA-compliant power-saving monitor. Further, this
2738	  option doesn't work for all laptops -- it might not turn off your
2739	  backlight at all, or it might print a lot of errors to the console,
2740	  especially if you are using gpm.
2741
2742config APM_ALLOW_INTS
2743	bool "Allow interrupts during APM BIOS calls"
2744	help
2745	  Normally we disable external interrupts while we are making calls to
2746	  the APM BIOS as a measure to lessen the effects of a badly behaving
2747	  BIOS implementation.  The BIOS should reenable interrupts if it
2748	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2749	  many of the newer IBM Thinkpads.  If you experience hangs when you
2750	  suspend, try setting this to Y.  Otherwise, say N.
2751
2752endif # APM
2753
2754source "drivers/cpufreq/Kconfig"
2755
2756source "drivers/cpuidle/Kconfig"
2757
2758source "drivers/idle/Kconfig"
2759
2760endmenu
2761
2762menu "Bus options (PCI etc.)"
2763
2764choice
2765	prompt "PCI access mode"
2766	depends on X86_32 && PCI
2767	default PCI_GOANY
2768	help
2769	  On PCI systems, the BIOS can be used to detect the PCI devices and
2770	  determine their configuration. However, some old PCI motherboards
2771	  have BIOS bugs and may crash if this is done. Also, some embedded
2772	  PCI-based systems don't have any BIOS at all. Linux can also try to
2773	  detect the PCI hardware directly without using the BIOS.
2774
2775	  With this option, you can specify how Linux should detect the
2776	  PCI devices. If you choose "BIOS", the BIOS will be used,
2777	  if you choose "Direct", the BIOS won't be used, and if you
2778	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2779	  If you choose "Any", the kernel will try MMCONFIG, then the
2780	  direct access method and falls back to the BIOS if that doesn't
2781	  work. If unsure, go with the default, which is "Any".
2782
2783config PCI_GOBIOS
2784	bool "BIOS"
2785
2786config PCI_GOMMCONFIG
2787	bool "MMConfig"
2788
2789config PCI_GODIRECT
2790	bool "Direct"
2791
2792config PCI_GOOLPC
2793	bool "OLPC XO-1"
2794	depends on OLPC
2795
2796config PCI_GOANY
2797	bool "Any"
2798
2799endchoice
2800
2801config PCI_BIOS
2802	def_bool y
2803	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2804
2805# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2806config PCI_DIRECT
2807	def_bool y
2808	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2809
2810config PCI_MMCONFIG
2811	bool "Support mmconfig PCI config space access" if X86_64
2812	default y
2813	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2814	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2815
2816config PCI_OLPC
2817	def_bool y
2818	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2819
2820config PCI_XEN
2821	def_bool y
2822	depends on PCI && XEN
2823
2824config MMCONF_FAM10H
2825	def_bool y
2826	depends on X86_64 && PCI_MMCONFIG && ACPI
2827
2828config PCI_CNB20LE_QUIRK
2829	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2830	depends on PCI
2831	help
2832	  Read the PCI windows out of the CNB20LE host bridge. This allows
2833	  PCI hotplug to work on systems with the CNB20LE chipset which do
2834	  not have ACPI.
2835
2836	  There's no public spec for this chipset, and this functionality
2837	  is known to be incomplete.
2838
2839	  You should say N unless you know you need this.
2840
2841config ISA_BUS
2842	bool "ISA bus support on modern systems" if EXPERT
2843	help
2844	  Expose ISA bus device drivers and options available for selection and
2845	  configuration. Enable this option if your target machine has an ISA
2846	  bus. ISA is an older system, displaced by PCI and newer bus
2847	  architectures -- if your target machine is modern, it probably does
2848	  not have an ISA bus.
2849
2850	  If unsure, say N.
2851
2852# x86_64 have no ISA slots, but can have ISA-style DMA.
2853config ISA_DMA_API
2854	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2855	default y
2856	help
2857	  Enables ISA-style DMA support for devices requiring such controllers.
2858	  If unsure, say Y.
2859
2860if X86_32
2861
2862config ISA
2863	bool "ISA support"
2864	help
2865	  Find out whether you have ISA slots on your motherboard.  ISA is the
2866	  name of a bus system, i.e. the way the CPU talks to the other stuff
2867	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2868	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2869	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2870
2871config SCx200
2872	tristate "NatSemi SCx200 support"
2873	help
2874	  This provides basic support for National Semiconductor's
2875	  (now AMD's) Geode processors.  The driver probes for the
2876	  PCI-IDs of several on-chip devices, so its a good dependency
2877	  for other scx200_* drivers.
2878
2879	  If compiled as a module, the driver is named scx200.
2880
2881config SCx200HR_TIMER
2882	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2883	depends on SCx200
2884	default y
2885	help
2886	  This driver provides a clocksource built upon the on-chip
2887	  27MHz high-resolution timer.  Its also a workaround for
2888	  NSC Geode SC-1100's buggy TSC, which loses time when the
2889	  processor goes idle (as is done by the scheduler).  The
2890	  other workaround is idle=poll boot option.
2891
2892config OLPC
2893	bool "One Laptop Per Child support"
2894	depends on !X86_PAE
2895	select GPIOLIB
2896	select OF
2897	select OF_PROMTREE
2898	select IRQ_DOMAIN
2899	select OLPC_EC
2900	help
2901	  Add support for detecting the unique features of the OLPC
2902	  XO hardware.
2903
2904config OLPC_XO1_PM
2905	bool "OLPC XO-1 Power Management"
2906	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2907	help
2908	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2909
2910config OLPC_XO1_RTC
2911	bool "OLPC XO-1 Real Time Clock"
2912	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2913	help
2914	  Add support for the XO-1 real time clock, which can be used as a
2915	  programmable wakeup source.
2916
2917config OLPC_XO1_SCI
2918	bool "OLPC XO-1 SCI extras"
2919	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2920	depends on INPUT=y
2921	select POWER_SUPPLY
2922	help
2923	  Add support for SCI-based features of the OLPC XO-1 laptop:
2924	   - EC-driven system wakeups
2925	   - Power button
2926	   - Ebook switch
2927	   - Lid switch
2928	   - AC adapter status updates
2929	   - Battery status updates
2930
2931config OLPC_XO15_SCI
2932	bool "OLPC XO-1.5 SCI extras"
2933	depends on OLPC && ACPI
2934	select POWER_SUPPLY
2935	help
2936	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2937	   - EC-driven system wakeups
2938	   - AC adapter status updates
2939	   - Battery status updates
2940
2941config ALIX
2942	bool "PCEngines ALIX System Support (LED setup)"
2943	select GPIOLIB
2944	help
2945	  This option enables system support for the PCEngines ALIX.
2946	  At present this just sets up LEDs for GPIO control on
2947	  ALIX2/3/6 boards.  However, other system specific setup should
2948	  get added here.
2949
2950	  Note: You must still enable the drivers for GPIO and LED support
2951	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2952
2953	  Note: You have to set alix.force=1 for boards with Award BIOS.
2954
2955config NET5501
2956	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2957	select GPIOLIB
2958	help
2959	  This option enables system support for the Soekris Engineering net5501.
2960
2961config GEOS
2962	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2963	select GPIOLIB
2964	depends on DMI
2965	help
2966	  This option enables system support for the Traverse Technologies GEOS.
2967
2968config TS5500
2969	bool "Technologic Systems TS-5500 platform support"
2970	depends on MELAN
2971	select CHECK_SIGNATURE
2972	select NEW_LEDS
2973	select LEDS_CLASS
2974	help
2975	  This option enables system support for the Technologic Systems TS-5500.
2976
2977endif # X86_32
2978
2979config AMD_NB
2980	def_bool y
2981	depends on CPU_SUP_AMD && PCI
2982
2983endmenu
2984
2985menu "Binary Emulations"
2986
2987config IA32_EMULATION
2988	bool "IA32 Emulation"
2989	depends on X86_64
2990	select ARCH_WANT_OLD_COMPAT_IPC
2991	select BINFMT_ELF
2992	select COMPAT_OLD_SIGACTION
2993	help
2994	  Include code to run legacy 32-bit programs under a
2995	  64-bit kernel. You should likely turn this on, unless you're
2996	  100% sure that you don't have any 32-bit programs left.
2997
2998config X86_X32_ABI
2999	bool "x32 ABI for 64-bit mode"
3000	depends on X86_64
3001	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3002	# compressed debug sections to x86_x32 properly:
3003	# https://github.com/ClangBuiltLinux/linux/issues/514
3004	# https://github.com/ClangBuiltLinux/linux/issues/1141
3005	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3006	help
3007	  Include code to run binaries for the x32 native 32-bit ABI
3008	  for 64-bit processors.  An x32 process gets access to the
3009	  full 64-bit register file and wide data path while leaving
3010	  pointers at 32 bits for smaller memory footprint.
3011
3012config COMPAT_32
3013	def_bool y
3014	depends on IA32_EMULATION || X86_32
3015	select HAVE_UID16
3016	select OLD_SIGSUSPEND3
3017
3018config COMPAT
3019	def_bool y
3020	depends on IA32_EMULATION || X86_X32_ABI
3021
3022config COMPAT_FOR_U64_ALIGNMENT
3023	def_bool y
3024	depends on COMPAT
3025
3026endmenu
3027
3028config HAVE_ATOMIC_IOMAP
3029	def_bool y
3030	depends on X86_32
3031
3032source "arch/x86/kvm/Kconfig"
3033
3034source "arch/x86/Kconfig.assembler"
3035