xref: /openbmc/linux/arch/x86/Kconfig (revision 84e85359)
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_USE_CMPXCHG_LOCKREF
31	select HAVE_ARCH_SOFT_DIRTY
32	select MODULES_USE_ELF_RELA
33	select NEED_DMA_MAP_STATE
34	select SWIOTLB
35	select ARCH_HAS_ELFCORE_COMPAT
36	select ZONE_DMA32
37
38config FORCE_DYNAMIC_FTRACE
39	def_bool y
40	depends on X86_32
41	depends on FUNCTION_TRACER
42	select DYNAMIC_FTRACE
43	help
44	  We keep the static function tracing (!DYNAMIC_FTRACE) around
45	  in order to test the non static function tracing in the
46	  generic code, as other architectures still use it. But we
47	  only need to keep it around for x86_64. No need to keep it
48	  for x86_32. For x86_32, force DYNAMIC_FTRACE.
49#
50# Arch settings
51#
52# ( Note that options that are marked 'if X86_64' could in principle be
53#   ported to 32-bit as well. )
54#
55config X86
56	def_bool y
57	#
58	# Note: keep this list sorted alphabetically
59	#
60	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
61	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
62	select ARCH_32BIT_OFF_T			if X86_32
63	select ARCH_CLOCKSOURCE_INIT
64	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
65	select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
66	select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64
67	select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
68	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
69	select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
70	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
71	select ARCH_HAS_CACHE_LINE_SIZE
72	select ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
73	select ARCH_HAS_CURRENT_STACK_POINTER
74	select ARCH_HAS_DEBUG_VIRTUAL
75	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
76	select ARCH_HAS_DEVMEM_IS_ALLOWED
77	select ARCH_HAS_EARLY_DEBUG		if KGDB
78	select ARCH_HAS_ELF_RANDOMIZE
79	select ARCH_HAS_FAST_MULTIPLIER
80	select ARCH_HAS_FORTIFY_SOURCE
81	select ARCH_HAS_GCOV_PROFILE_ALL
82	select ARCH_HAS_KCOV			if X86_64
83	select ARCH_HAS_MEM_ENCRYPT
84	select ARCH_HAS_MEMBARRIER_SYNC_CORE
85	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
86	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
87	select ARCH_HAS_PMEM_API		if X86_64
88	select ARCH_HAS_PTE_DEVMAP		if X86_64
89	select ARCH_HAS_PTE_SPECIAL
90	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
91	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
92	select ARCH_HAS_COPY_MC			if X86_64
93	select ARCH_HAS_SET_MEMORY
94	select ARCH_HAS_SET_DIRECT_MAP
95	select ARCH_HAS_STRICT_KERNEL_RWX
96	select ARCH_HAS_STRICT_MODULE_RWX
97	select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
98	select ARCH_HAS_SYSCALL_WRAPPER
99	select ARCH_HAS_UBSAN_SANITIZE_ALL
100	select ARCH_HAS_DEBUG_WX
101	select ARCH_HAS_ZONE_DMA_SET if EXPERT
102	select ARCH_HAVE_NMI_SAFE_CMPXCHG
103	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
104	select ARCH_MIGHT_HAVE_PC_PARPORT
105	select ARCH_MIGHT_HAVE_PC_SERIO
106	select ARCH_STACKWALK
107	select ARCH_SUPPORTS_ACPI
108	select ARCH_SUPPORTS_ATOMIC_RMW
109	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
110	select ARCH_SUPPORTS_PAGE_TABLE_CHECK	if X86_64
111	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
112	select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP	if NR_CPUS <= 4096
113	select ARCH_SUPPORTS_CFI_CLANG		if X86_64
114	select ARCH_USES_CFI_TRAPS		if X86_64 && CFI_CLANG
115	select ARCH_SUPPORTS_LTO_CLANG
116	select ARCH_SUPPORTS_LTO_CLANG_THIN
117	select ARCH_USE_BUILTIN_BSWAP
118	select ARCH_USE_MEMTEST
119	select ARCH_USE_QUEUED_RWLOCKS
120	select ARCH_USE_QUEUED_SPINLOCKS
121	select ARCH_USE_SYM_ANNOTATIONS
122	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
123	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
124	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
125	select ARCH_WANTS_NO_INSTR
126	select ARCH_WANT_GENERAL_HUGETLB
127	select ARCH_WANT_HUGE_PMD_SHARE
128	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP	if X86_64
129	select ARCH_WANT_LD_ORPHAN_WARN
130	select ARCH_WANTS_THP_SWAP		if X86_64
131	select ARCH_HAS_PARANOID_L1D_FLUSH
132	select BUILDTIME_TABLE_SORT
133	select CLKEVT_I8253
134	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
135	select CLOCKSOURCE_WATCHDOG
136	# Word-size accesses may read uninitialized data past the trailing \0
137	# in strings and cause false KMSAN reports.
138	select DCACHE_WORD_ACCESS		if !KMSAN
139	select DYNAMIC_SIGFRAME
140	select EDAC_ATOMIC_SCRUB
141	select EDAC_SUPPORT
142	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
143	select GENERIC_CLOCKEVENTS_MIN_ADJUST
144	select GENERIC_CMOS_UPDATE
145	select GENERIC_CPU_AUTOPROBE
146	select GENERIC_CPU_VULNERABILITIES
147	select GENERIC_EARLY_IOREMAP
148	select GENERIC_ENTRY
149	select GENERIC_IOMAP
150	select GENERIC_IRQ_EFFECTIVE_AFF_MASK	if SMP
151	select GENERIC_IRQ_MATRIX_ALLOCATOR	if X86_LOCAL_APIC
152	select GENERIC_IRQ_MIGRATION		if SMP
153	select GENERIC_IRQ_PROBE
154	select GENERIC_IRQ_RESERVATION_MODE
155	select GENERIC_IRQ_SHOW
156	select GENERIC_PENDING_IRQ		if SMP
157	select GENERIC_PTDUMP
158	select GENERIC_SMP_IDLE_THREAD
159	select GENERIC_TIME_VSYSCALL
160	select GENERIC_GETTIMEOFDAY
161	select GENERIC_VDSO_TIME_NS
162	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
163	select HARDIRQS_SW_RESEND
164	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
165	select HAVE_ACPI_APEI			if ACPI
166	select HAVE_ACPI_APEI_NMI		if ACPI
167	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
168	select HAVE_ARCH_AUDITSYSCALL
169	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
170	select HAVE_ARCH_HUGE_VMALLOC		if X86_64
171	select HAVE_ARCH_JUMP_LABEL
172	select HAVE_ARCH_JUMP_LABEL_RELATIVE
173	select HAVE_ARCH_KASAN			if X86_64
174	select HAVE_ARCH_KASAN_VMALLOC		if X86_64
175	select HAVE_ARCH_KFENCE
176	select HAVE_ARCH_KMSAN			if X86_64
177	select HAVE_ARCH_KGDB
178	select HAVE_ARCH_MMAP_RND_BITS		if MMU
179	select HAVE_ARCH_MMAP_RND_COMPAT_BITS	if MMU && COMPAT
180	select HAVE_ARCH_COMPAT_MMAP_BASES	if MMU && COMPAT
181	select HAVE_ARCH_PREL32_RELOCATIONS
182	select HAVE_ARCH_SECCOMP_FILTER
183	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
184	select HAVE_ARCH_STACKLEAK
185	select HAVE_ARCH_TRACEHOOK
186	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
187	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
188	select HAVE_ARCH_USERFAULTFD_WP         if X86_64 && USERFAULTFD
189	select HAVE_ARCH_USERFAULTFD_MINOR	if X86_64 && USERFAULTFD
190	select HAVE_ARCH_VMAP_STACK		if X86_64
191	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
192	select HAVE_ARCH_WITHIN_STACK_FRAMES
193	select HAVE_ASM_MODVERSIONS
194	select HAVE_CMPXCHG_DOUBLE
195	select HAVE_CMPXCHG_LOCAL
196	select HAVE_CONTEXT_TRACKING_USER		if X86_64
197	select HAVE_CONTEXT_TRACKING_USER_OFFSTACK	if HAVE_CONTEXT_TRACKING_USER
198	select HAVE_C_RECORDMCOUNT
199	select HAVE_OBJTOOL_MCOUNT		if HAVE_OBJTOOL
200	select HAVE_BUILDTIME_MCOUNT_SORT
201	select HAVE_DEBUG_KMEMLEAK
202	select HAVE_DMA_CONTIGUOUS
203	select HAVE_DYNAMIC_FTRACE
204	select HAVE_DYNAMIC_FTRACE_WITH_REGS
205	select HAVE_DYNAMIC_FTRACE_WITH_ARGS	if X86_64
206	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
207	select HAVE_SAMPLE_FTRACE_DIRECT	if X86_64
208	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI	if X86_64
209	select HAVE_EBPF_JIT
210	select HAVE_EFFICIENT_UNALIGNED_ACCESS
211	select HAVE_EISA
212	select HAVE_EXIT_THREAD
213	select HAVE_FAST_GUP
214	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
215	select HAVE_FTRACE_MCOUNT_RECORD
216	select HAVE_FUNCTION_GRAPH_TRACER	if X86_32 || (X86_64 && DYNAMIC_FTRACE)
217	select HAVE_FUNCTION_TRACER
218	select HAVE_GCC_PLUGINS
219	select HAVE_HW_BREAKPOINT
220	select HAVE_IOREMAP_PROT
221	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
222	select HAVE_IRQ_TIME_ACCOUNTING
223	select HAVE_JUMP_LABEL_HACK		if HAVE_OBJTOOL
224	select HAVE_KERNEL_BZIP2
225	select HAVE_KERNEL_GZIP
226	select HAVE_KERNEL_LZ4
227	select HAVE_KERNEL_LZMA
228	select HAVE_KERNEL_LZO
229	select HAVE_KERNEL_XZ
230	select HAVE_KERNEL_ZSTD
231	select HAVE_KPROBES
232	select HAVE_KPROBES_ON_FTRACE
233	select HAVE_FUNCTION_ERROR_INJECTION
234	select HAVE_KRETPROBES
235	select HAVE_RETHOOK
236	select HAVE_KVM
237	select HAVE_LIVEPATCH			if X86_64
238	select HAVE_MIXED_BREAKPOINTS_REGS
239	select HAVE_MOD_ARCH_SPECIFIC
240	select HAVE_MOVE_PMD
241	select HAVE_MOVE_PUD
242	select HAVE_NOINSTR_HACK		if HAVE_OBJTOOL
243	select HAVE_NMI
244	select HAVE_NOINSTR_VALIDATION		if HAVE_OBJTOOL
245	select HAVE_OBJTOOL			if X86_64
246	select HAVE_OPTPROBES
247	select HAVE_PCSPKR_PLATFORM
248	select HAVE_PERF_EVENTS
249	select HAVE_PERF_EVENTS_NMI
250	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
251	select HAVE_PCI
252	select HAVE_PERF_REGS
253	select HAVE_PERF_USER_STACK_DUMP
254	select MMU_GATHER_RCU_TABLE_FREE	if PARAVIRT
255	select MMU_GATHER_MERGE_VMAS
256	select HAVE_POSIX_CPU_TIMERS_TASK_WORK
257	select HAVE_REGS_AND_STACK_ACCESS_API
258	select HAVE_RELIABLE_STACKTRACE		if UNWINDER_ORC || STACK_VALIDATION
259	select HAVE_FUNCTION_ARG_ACCESS_API
260	select HAVE_SETUP_PER_CPU_AREA
261	select HAVE_SOFTIRQ_ON_OWN_STACK
262	select HAVE_STACKPROTECTOR		if CC_HAS_SANE_STACKPROTECTOR
263	select HAVE_STACK_VALIDATION		if HAVE_OBJTOOL
264	select HAVE_STATIC_CALL
265	select HAVE_STATIC_CALL_INLINE		if HAVE_OBJTOOL
266	select HAVE_PREEMPT_DYNAMIC_CALL
267	select HAVE_RSEQ
268	select HAVE_RUST			if X86_64
269	select HAVE_SYSCALL_TRACEPOINTS
270	select HAVE_UACCESS_VALIDATION		if HAVE_OBJTOOL
271	select HAVE_UNSTABLE_SCHED_CLOCK
272	select HAVE_USER_RETURN_NOTIFIER
273	select HAVE_GENERIC_VDSO
274	select HOTPLUG_SMT			if SMP
275	select IRQ_FORCED_THREADING
276	select NEED_PER_CPU_EMBED_FIRST_CHUNK
277	select NEED_PER_CPU_PAGE_FIRST_CHUNK
278	select NEED_SG_DMA_LENGTH
279	select PCI_DOMAINS			if PCI
280	select PCI_LOCKLESS_CONFIG		if PCI
281	select PERF_EVENTS
282	select RTC_LIB
283	select RTC_MC146818_LIB
284	select SPARSE_IRQ
285	select SRCU
286	select SYSCTL_EXCEPTION_TRACE
287	select THREAD_INFO_IN_TASK
288	select TRACE_IRQFLAGS_SUPPORT
289	select TRACE_IRQFLAGS_NMI_SUPPORT
290	select USER_STACKTRACE_SUPPORT
291	select HAVE_ARCH_KCSAN			if X86_64
292	select X86_FEATURE_NAMES		if PROC_FS
293	select PROC_PID_ARCH_STATUS		if PROC_FS
294	select HAVE_ARCH_NODE_DEV_GROUP		if X86_SGX
295	select FUNCTION_ALIGNMENT_16B		if X86_64 || X86_ALIGNMENT_16
296	select FUNCTION_ALIGNMENT_4B
297	imply IMA_SECURE_AND_OR_TRUSTED_BOOT    if EFI
298	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
299
300config INSTRUCTION_DECODER
301	def_bool y
302	depends on KPROBES || PERF_EVENTS || UPROBES
303
304config OUTPUT_FORMAT
305	string
306	default "elf32-i386" if X86_32
307	default "elf64-x86-64" if X86_64
308
309config LOCKDEP_SUPPORT
310	def_bool y
311
312config STACKTRACE_SUPPORT
313	def_bool y
314
315config MMU
316	def_bool y
317
318config ARCH_MMAP_RND_BITS_MIN
319	default 28 if 64BIT
320	default 8
321
322config ARCH_MMAP_RND_BITS_MAX
323	default 32 if 64BIT
324	default 16
325
326config ARCH_MMAP_RND_COMPAT_BITS_MIN
327	default 8
328
329config ARCH_MMAP_RND_COMPAT_BITS_MAX
330	default 16
331
332config SBUS
333	bool
334
335config GENERIC_ISA_DMA
336	def_bool y
337	depends on ISA_DMA_API
338
339config GENERIC_CSUM
340	bool
341	default y if KMSAN || KASAN
342
343config GENERIC_BUG
344	def_bool y
345	depends on BUG
346	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
347
348config GENERIC_BUG_RELATIVE_POINTERS
349	bool
350
351config ARCH_MAY_HAVE_PC_FDC
352	def_bool y
353	depends on ISA_DMA_API
354
355config GENERIC_CALIBRATE_DELAY
356	def_bool y
357
358config ARCH_HAS_CPU_RELAX
359	def_bool y
360
361config ARCH_HIBERNATION_POSSIBLE
362	def_bool y
363
364config ARCH_SUSPEND_POSSIBLE
365	def_bool y
366
367config AUDIT_ARCH
368	def_bool y if X86_64
369
370config KASAN_SHADOW_OFFSET
371	hex
372	depends on KASAN
373	default 0xdffffc0000000000
374
375config HAVE_INTEL_TXT
376	def_bool y
377	depends on INTEL_IOMMU && ACPI
378
379config X86_32_SMP
380	def_bool y
381	depends on X86_32 && SMP
382
383config X86_64_SMP
384	def_bool y
385	depends on X86_64 && SMP
386
387config ARCH_SUPPORTS_UPROBES
388	def_bool y
389
390config FIX_EARLYCON_MEM
391	def_bool y
392
393config DYNAMIC_PHYSICAL_MASK
394	bool
395
396config PGTABLE_LEVELS
397	int
398	default 5 if X86_5LEVEL
399	default 4 if X86_64
400	default 3 if X86_PAE
401	default 2
402
403config CC_HAS_SANE_STACKPROTECTOR
404	bool
405	default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT
406	default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS))
407	help
408	  We have to make sure stack protector is unconditionally disabled if
409	  the compiler produces broken code or if it does not let us control
410	  the segment on 32-bit kernels.
411
412menu "Processor type and features"
413
414config SMP
415	bool "Symmetric multi-processing support"
416	help
417	  This enables support for systems with more than one CPU. If you have
418	  a system with only one CPU, say N. If you have a system with more
419	  than one CPU, say Y.
420
421	  If you say N here, the kernel will run on uni- and multiprocessor
422	  machines, but will use only one CPU of a multiprocessor machine. If
423	  you say Y here, the kernel will run on many, but not all,
424	  uniprocessor machines. On a uniprocessor machine, the kernel
425	  will run faster if you say N here.
426
427	  Note that if you say Y here and choose architecture "586" or
428	  "Pentium" under "Processor family", the kernel will not work on 486
429	  architectures. Similarly, multiprocessor kernels for the "PPro"
430	  architecture may not work on all Pentium based boards.
431
432	  People using multiprocessor machines who say Y here should also say
433	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
434	  Management" code will be disabled if you say Y here.
435
436	  See also <file:Documentation/x86/i386/IO-APIC.rst>,
437	  <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
438	  <http://www.tldp.org/docs.html#howto>.
439
440	  If you don't know what to do here, say N.
441
442config X86_FEATURE_NAMES
443	bool "Processor feature human-readable names" if EMBEDDED
444	default y
445	help
446	  This option compiles in a table of x86 feature bits and corresponding
447	  names.  This is required to support /proc/cpuinfo and a few kernel
448	  messages.  You can disable this to save space, at the expense of
449	  making those few kernel messages show numeric feature bits instead.
450
451	  If in doubt, say Y.
452
453config X86_X2APIC
454	bool "Support x2apic"
455	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
456	help
457	  This enables x2apic support on CPUs that have this feature.
458
459	  This allows 32-bit apic IDs (so it can support very large systems),
460	  and accesses the local apic via MSRs not via mmio.
461
462	  Some Intel systems circa 2022 and later are locked into x2APIC mode
463	  and can not fall back to the legacy APIC modes if SGX or TDX are
464	  enabled in the BIOS. They will boot with very reduced functionality
465	  without enabling this option.
466
467	  If you don't know what to do here, say N.
468
469config X86_MPPARSE
470	bool "Enable MPS table" if ACPI
471	default y
472	depends on X86_LOCAL_APIC
473	help
474	  For old smp systems that do not have proper acpi support. Newer systems
475	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
476
477config GOLDFISH
478	def_bool y
479	depends on X86_GOLDFISH
480
481config X86_CPU_RESCTRL
482	bool "x86 CPU resource control support"
483	depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
484	select KERNFS
485	select PROC_CPU_RESCTRL		if PROC_FS
486	help
487	  Enable x86 CPU resource control support.
488
489	  Provide support for the allocation and monitoring of system resources
490	  usage by the CPU.
491
492	  Intel calls this Intel Resource Director Technology
493	  (Intel(R) RDT). More information about RDT can be found in the
494	  Intel x86 Architecture Software Developer Manual.
495
496	  AMD calls this AMD Platform Quality of Service (AMD QoS).
497	  More information about AMD QoS can be found in the AMD64 Technology
498	  Platform Quality of Service Extensions manual.
499
500	  Say N if unsure.
501
502if X86_32
503config X86_BIGSMP
504	bool "Support for big SMP systems with more than 8 CPUs"
505	depends on SMP
506	help
507	  This option is needed for the systems that have more than 8 CPUs.
508
509config X86_EXTENDED_PLATFORM
510	bool "Support for extended (non-PC) x86 platforms"
511	default y
512	help
513	  If you disable this option then the kernel will only support
514	  standard PC platforms. (which covers the vast majority of
515	  systems out there.)
516
517	  If you enable this option then you'll be able to select support
518	  for the following (non-PC) 32 bit x86 platforms:
519		Goldfish (Android emulator)
520		AMD Elan
521		RDC R-321x SoC
522		SGI 320/540 (Visual Workstation)
523		STA2X11-based (e.g. Northville)
524		Moorestown MID devices
525
526	  If you have one of these systems, or if you want to build a
527	  generic distribution kernel, say Y here - otherwise say N.
528endif # X86_32
529
530if X86_64
531config X86_EXTENDED_PLATFORM
532	bool "Support for extended (non-PC) x86 platforms"
533	default y
534	help
535	  If you disable this option then the kernel will only support
536	  standard PC platforms. (which covers the vast majority of
537	  systems out there.)
538
539	  If you enable this option then you'll be able to select support
540	  for the following (non-PC) 64 bit x86 platforms:
541		Numascale NumaChip
542		ScaleMP vSMP
543		SGI Ultraviolet
544
545	  If you have one of these systems, or if you want to build a
546	  generic distribution kernel, say Y here - otherwise say N.
547endif # X86_64
548# This is an alphabetically sorted list of 64 bit extended platforms
549# Please maintain the alphabetic order if and when there are additions
550config X86_NUMACHIP
551	bool "Numascale NumaChip"
552	depends on X86_64
553	depends on X86_EXTENDED_PLATFORM
554	depends on NUMA
555	depends on SMP
556	depends on X86_X2APIC
557	depends on PCI_MMCONFIG
558	help
559	  Adds support for Numascale NumaChip large-SMP systems. Needed to
560	  enable more than ~168 cores.
561	  If you don't have one of these, you should say N here.
562
563config X86_VSMP
564	bool "ScaleMP vSMP"
565	select HYPERVISOR_GUEST
566	select PARAVIRT
567	depends on X86_64 && PCI
568	depends on X86_EXTENDED_PLATFORM
569	depends on SMP
570	help
571	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
572	  supposed to run on these EM64T-based machines.  Only choose this option
573	  if you have one of these machines.
574
575config X86_UV
576	bool "SGI Ultraviolet"
577	depends on X86_64
578	depends on X86_EXTENDED_PLATFORM
579	depends on NUMA
580	depends on EFI
581	depends on KEXEC_CORE
582	depends on X86_X2APIC
583	depends on PCI
584	help
585	  This option is needed in order to support SGI Ultraviolet systems.
586	  If you don't have one of these, you should say N here.
587
588# Following is an alphabetically sorted list of 32 bit extended platforms
589# Please maintain the alphabetic order if and when there are additions
590
591config X86_GOLDFISH
592	bool "Goldfish (Virtual Platform)"
593	depends on X86_EXTENDED_PLATFORM
594	help
595	  Enable support for the Goldfish virtual platform used primarily
596	  for Android development. Unless you are building for the Android
597	  Goldfish emulator say N here.
598
599config X86_INTEL_CE
600	bool "CE4100 TV platform"
601	depends on PCI
602	depends on PCI_GODIRECT
603	depends on X86_IO_APIC
604	depends on X86_32
605	depends on X86_EXTENDED_PLATFORM
606	select X86_REBOOTFIXUPS
607	select OF
608	select OF_EARLY_FLATTREE
609	help
610	  Select for the Intel CE media processor (CE4100) SOC.
611	  This option compiles in support for the CE4100 SOC for settop
612	  boxes and media devices.
613
614config X86_INTEL_MID
615	bool "Intel MID platform support"
616	depends on X86_EXTENDED_PLATFORM
617	depends on X86_PLATFORM_DEVICES
618	depends on PCI
619	depends on X86_64 || (PCI_GOANY && X86_32)
620	depends on X86_IO_APIC
621	select I2C
622	select DW_APB_TIMER
623	select INTEL_SCU_PCI
624	help
625	  Select to build a kernel capable of supporting Intel MID (Mobile
626	  Internet Device) platform systems which do not have the PCI legacy
627	  interfaces. If you are building for a PC class system say N here.
628
629	  Intel MID platforms are based on an Intel processor and chipset which
630	  consume less power than most of the x86 derivatives.
631
632config X86_INTEL_QUARK
633	bool "Intel Quark platform support"
634	depends on X86_32
635	depends on X86_EXTENDED_PLATFORM
636	depends on X86_PLATFORM_DEVICES
637	depends on X86_TSC
638	depends on PCI
639	depends on PCI_GOANY
640	depends on X86_IO_APIC
641	select IOSF_MBI
642	select INTEL_IMR
643	select COMMON_CLK
644	help
645	  Select to include support for Quark X1000 SoC.
646	  Say Y here if you have a Quark based system such as the Arduino
647	  compatible Intel Galileo.
648
649config X86_INTEL_LPSS
650	bool "Intel Low Power Subsystem Support"
651	depends on X86 && ACPI && PCI
652	select COMMON_CLK
653	select PINCTRL
654	select IOSF_MBI
655	help
656	  Select to build support for Intel Low Power Subsystem such as
657	  found on Intel Lynxpoint PCH. Selecting this option enables
658	  things like clock tree (common clock framework) and pincontrol
659	  which are needed by the LPSS peripheral drivers.
660
661config X86_AMD_PLATFORM_DEVICE
662	bool "AMD ACPI2Platform devices support"
663	depends on ACPI
664	select COMMON_CLK
665	select PINCTRL
666	help
667	  Select to interpret AMD specific ACPI device to platform device
668	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
669	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
670	  implemented under PINCTRL subsystem.
671
672config IOSF_MBI
673	tristate "Intel SoC IOSF Sideband support for SoC platforms"
674	depends on PCI
675	help
676	  This option enables sideband register access support for Intel SoC
677	  platforms. On these platforms the IOSF sideband is used in lieu of
678	  MSR's for some register accesses, mostly but not limited to thermal
679	  and power. Drivers may query the availability of this device to
680	  determine if they need the sideband in order to work on these
681	  platforms. The sideband is available on the following SoC products.
682	  This list is not meant to be exclusive.
683	   - BayTrail
684	   - Braswell
685	   - Quark
686
687	  You should say Y if you are running a kernel on one of these SoC's.
688
689config IOSF_MBI_DEBUG
690	bool "Enable IOSF sideband access through debugfs"
691	depends on IOSF_MBI && DEBUG_FS
692	help
693	  Select this option to expose the IOSF sideband access registers (MCR,
694	  MDR, MCRX) through debugfs to write and read register information from
695	  different units on the SoC. This is most useful for obtaining device
696	  state information for debug and analysis. As this is a general access
697	  mechanism, users of this option would have specific knowledge of the
698	  device they want to access.
699
700	  If you don't require the option or are in doubt, say N.
701
702config X86_RDC321X
703	bool "RDC R-321x SoC"
704	depends on X86_32
705	depends on X86_EXTENDED_PLATFORM
706	select M486
707	select X86_REBOOTFIXUPS
708	help
709	  This option is needed for RDC R-321x system-on-chip, also known
710	  as R-8610-(G).
711	  If you don't have one of these chips, you should say N here.
712
713config X86_32_NON_STANDARD
714	bool "Support non-standard 32-bit SMP architectures"
715	depends on X86_32 && SMP
716	depends on X86_EXTENDED_PLATFORM
717	help
718	  This option compiles in the bigsmp and STA2X11 default
719	  subarchitectures.  It is intended for a generic binary
720	  kernel. If you select them all, kernel will probe it one by
721	  one and will fallback to default.
722
723# Alphabetically sorted list of Non standard 32 bit platforms
724
725config X86_SUPPORTS_MEMORY_FAILURE
726	def_bool y
727	# MCE code calls memory_failure():
728	depends on X86_MCE
729	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
730	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
731	depends on X86_64 || !SPARSEMEM
732	select ARCH_SUPPORTS_MEMORY_FAILURE
733
734config STA2X11
735	bool "STA2X11 Companion Chip Support"
736	depends on X86_32_NON_STANDARD && PCI
737	select SWIOTLB
738	select MFD_STA2X11
739	select GPIOLIB
740	help
741	  This adds support for boards based on the STA2X11 IO-Hub,
742	  a.k.a. "ConneXt". The chip is used in place of the standard
743	  PC chipset, so all "standard" peripherals are missing. If this
744	  option is selected the kernel will still be able to boot on
745	  standard PC machines.
746
747config X86_32_IRIS
748	tristate "Eurobraille/Iris poweroff module"
749	depends on X86_32
750	help
751	  The Iris machines from EuroBraille do not have APM or ACPI support
752	  to shut themselves down properly.  A special I/O sequence is
753	  needed to do so, which is what this module does at
754	  kernel shutdown.
755
756	  This is only for Iris machines from EuroBraille.
757
758	  If unused, say N.
759
760config SCHED_OMIT_FRAME_POINTER
761	def_bool y
762	prompt "Single-depth WCHAN output"
763	depends on X86
764	help
765	  Calculate simpler /proc/<PID>/wchan values. If this option
766	  is disabled then wchan values will recurse back to the
767	  caller function. This provides more accurate wchan values,
768	  at the expense of slightly more scheduling overhead.
769
770	  If in doubt, say "Y".
771
772menuconfig HYPERVISOR_GUEST
773	bool "Linux guest support"
774	help
775	  Say Y here to enable options for running Linux under various hyper-
776	  visors. This option enables basic hypervisor detection and platform
777	  setup.
778
779	  If you say N, all options in this submenu will be skipped and
780	  disabled, and Linux guest support won't be built in.
781
782if HYPERVISOR_GUEST
783
784config PARAVIRT
785	bool "Enable paravirtualization code"
786	depends on HAVE_STATIC_CALL
787	help
788	  This changes the kernel so it can modify itself when it is run
789	  under a hypervisor, potentially improving performance significantly
790	  over full virtualization.  However, when run without a hypervisor
791	  the kernel is theoretically slower and slightly larger.
792
793config PARAVIRT_XXL
794	bool
795
796config PARAVIRT_DEBUG
797	bool "paravirt-ops debugging"
798	depends on PARAVIRT && DEBUG_KERNEL
799	help
800	  Enable to debug paravirt_ops internals.  Specifically, BUG if
801	  a paravirt_op is missing when it is called.
802
803config PARAVIRT_SPINLOCKS
804	bool "Paravirtualization layer for spinlocks"
805	depends on PARAVIRT && SMP
806	help
807	  Paravirtualized spinlocks allow a pvops backend to replace the
808	  spinlock implementation with something virtualization-friendly
809	  (for example, block the virtual CPU rather than spinning).
810
811	  It has a minimal impact on native kernels and gives a nice performance
812	  benefit on paravirtualized KVM / Xen kernels.
813
814	  If you are unsure how to answer this question, answer Y.
815
816config X86_HV_CALLBACK_VECTOR
817	def_bool n
818
819source "arch/x86/xen/Kconfig"
820
821config KVM_GUEST
822	bool "KVM Guest support (including kvmclock)"
823	depends on PARAVIRT
824	select PARAVIRT_CLOCK
825	select ARCH_CPUIDLE_HALTPOLL
826	select X86_HV_CALLBACK_VECTOR
827	default y
828	help
829	  This option enables various optimizations for running under the KVM
830	  hypervisor. It includes a paravirtualized clock, so that instead
831	  of relying on a PIT (or probably other) emulation by the
832	  underlying device model, the host provides the guest with
833	  timing infrastructure such as time of day, and system time
834
835config ARCH_CPUIDLE_HALTPOLL
836	def_bool n
837	prompt "Disable host haltpoll when loading haltpoll driver"
838	help
839	  If virtualized under KVM, disable host haltpoll.
840
841config PVH
842	bool "Support for running PVH guests"
843	help
844	  This option enables the PVH entry point for guest virtual machines
845	  as specified in the x86/HVM direct boot ABI.
846
847config PARAVIRT_TIME_ACCOUNTING
848	bool "Paravirtual steal time accounting"
849	depends on PARAVIRT
850	help
851	  Select this option to enable fine granularity task steal time
852	  accounting. Time spent executing other tasks in parallel with
853	  the current vCPU is discounted from the vCPU power. To account for
854	  that, there can be a small performance impact.
855
856	  If in doubt, say N here.
857
858config PARAVIRT_CLOCK
859	bool
860
861config JAILHOUSE_GUEST
862	bool "Jailhouse non-root cell support"
863	depends on X86_64 && PCI
864	select X86_PM_TIMER
865	help
866	  This option allows to run Linux as guest in a Jailhouse non-root
867	  cell. You can leave this option disabled if you only want to start
868	  Jailhouse and run Linux afterwards in the root cell.
869
870config ACRN_GUEST
871	bool "ACRN Guest support"
872	depends on X86_64
873	select X86_HV_CALLBACK_VECTOR
874	help
875	  This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
876	  a flexible, lightweight reference open-source hypervisor, built with
877	  real-time and safety-criticality in mind. It is built for embedded
878	  IOT with small footprint and real-time features. More details can be
879	  found in https://projectacrn.org/.
880
881config INTEL_TDX_GUEST
882	bool "Intel TDX (Trust Domain Extensions) - Guest Support"
883	depends on X86_64 && CPU_SUP_INTEL
884	depends on X86_X2APIC
885	select ARCH_HAS_CC_PLATFORM
886	select X86_MEM_ENCRYPT
887	select X86_MCE
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	bool "CPU microcode loading support"
1315	default y
1316	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1317	help
1318	  If you say Y here, you will be able to update the microcode on
1319	  Intel and AMD processors. The Intel support is for the IA32 family,
1320	  e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1321	  AMD support is for families 0x10 and later. You will obviously need
1322	  the actual microcode binary data itself which is not shipped with
1323	  the Linux kernel.
1324
1325	  The preferred method to load microcode from a detached initrd is described
1326	  in Documentation/x86/microcode.rst. For that you need to enable
1327	  CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1328	  initrd for microcode blobs.
1329
1330	  In addition, you can build the microcode into the kernel. For that you
1331	  need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1332	  config option.
1333
1334config MICROCODE_INTEL
1335	bool "Intel microcode loading support"
1336	depends on CPU_SUP_INTEL && MICROCODE
1337	default MICROCODE
1338	help
1339	  This options enables microcode patch loading support for Intel
1340	  processors.
1341
1342	  For the current Intel microcode data package go to
1343	  <https://downloadcenter.intel.com> and search for
1344	  'Linux Processor Microcode Data File'.
1345
1346config MICROCODE_AMD
1347	bool "AMD microcode loading support"
1348	depends on CPU_SUP_AMD && MICROCODE
1349	help
1350	  If you select this option, microcode patch loading support for AMD
1351	  processors will be enabled.
1352
1353config MICROCODE_LATE_LOADING
1354	bool "Late microcode loading (DANGEROUS)"
1355	default n
1356	depends on MICROCODE
1357	help
1358	  Loading microcode late, when the system is up and executing instructions
1359	  is a tricky business and should be avoided if possible. Just the sequence
1360	  of synchronizing all cores and SMT threads is one fragile dance which does
1361	  not guarantee that cores might not softlock after the loading. Therefore,
1362	  use this at your own risk. Late loading taints the kernel too.
1363
1364config X86_MSR
1365	tristate "/dev/cpu/*/msr - Model-specific register support"
1366	help
1367	  This device gives privileged processes access to the x86
1368	  Model-Specific Registers (MSRs).  It is a character device with
1369	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1370	  MSR accesses are directed to a specific CPU on multi-processor
1371	  systems.
1372
1373config X86_CPUID
1374	tristate "/dev/cpu/*/cpuid - CPU information support"
1375	help
1376	  This device gives processes access to the x86 CPUID instruction to
1377	  be executed on a specific processor.  It is a character device
1378	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1379	  /dev/cpu/31/cpuid.
1380
1381choice
1382	prompt "High Memory Support"
1383	default HIGHMEM4G
1384	depends on X86_32
1385
1386config NOHIGHMEM
1387	bool "off"
1388	help
1389	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1390	  However, the address space of 32-bit x86 processors is only 4
1391	  Gigabytes large. That means that, if you have a large amount of
1392	  physical memory, not all of it can be "permanently mapped" by the
1393	  kernel. The physical memory that's not permanently mapped is called
1394	  "high memory".
1395
1396	  If you are compiling a kernel which will never run on a machine with
1397	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1398	  choice and suitable for most users). This will result in a "3GB/1GB"
1399	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1400	  space and the remaining part of the 4GB virtual memory space is used
1401	  by the kernel to permanently map as much physical memory as
1402	  possible.
1403
1404	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1405	  answer "4GB" here.
1406
1407	  If more than 4 Gigabytes is used then answer "64GB" here. This
1408	  selection turns Intel PAE (Physical Address Extension) mode on.
1409	  PAE implements 3-level paging on IA32 processors. PAE is fully
1410	  supported by Linux, PAE mode is implemented on all recent Intel
1411	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1412	  then the kernel will not boot on CPUs that don't support PAE!
1413
1414	  The actual amount of total physical memory will either be
1415	  auto detected or can be forced by using a kernel command line option
1416	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1417	  your boot loader (lilo or loadlin) about how to pass options to the
1418	  kernel at boot time.)
1419
1420	  If unsure, say "off".
1421
1422config HIGHMEM4G
1423	bool "4GB"
1424	help
1425	  Select this if you have a 32-bit processor and between 1 and 4
1426	  gigabytes of physical RAM.
1427
1428config HIGHMEM64G
1429	bool "64GB"
1430	depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
1431	select X86_PAE
1432	help
1433	  Select this if you have a 32-bit processor and more than 4
1434	  gigabytes of physical RAM.
1435
1436endchoice
1437
1438choice
1439	prompt "Memory split" if EXPERT
1440	default VMSPLIT_3G
1441	depends on X86_32
1442	help
1443	  Select the desired split between kernel and user memory.
1444
1445	  If the address range available to the kernel is less than the
1446	  physical memory installed, the remaining memory will be available
1447	  as "high memory". Accessing high memory is a little more costly
1448	  than low memory, as it needs to be mapped into the kernel first.
1449	  Note that increasing the kernel address space limits the range
1450	  available to user programs, making the address space there
1451	  tighter.  Selecting anything other than the default 3G/1G split
1452	  will also likely make your kernel incompatible with binary-only
1453	  kernel modules.
1454
1455	  If you are not absolutely sure what you are doing, leave this
1456	  option alone!
1457
1458	config VMSPLIT_3G
1459		bool "3G/1G user/kernel split"
1460	config VMSPLIT_3G_OPT
1461		depends on !X86_PAE
1462		bool "3G/1G user/kernel split (for full 1G low memory)"
1463	config VMSPLIT_2G
1464		bool "2G/2G user/kernel split"
1465	config VMSPLIT_2G_OPT
1466		depends on !X86_PAE
1467		bool "2G/2G user/kernel split (for full 2G low memory)"
1468	config VMSPLIT_1G
1469		bool "1G/3G user/kernel split"
1470endchoice
1471
1472config PAGE_OFFSET
1473	hex
1474	default 0xB0000000 if VMSPLIT_3G_OPT
1475	default 0x80000000 if VMSPLIT_2G
1476	default 0x78000000 if VMSPLIT_2G_OPT
1477	default 0x40000000 if VMSPLIT_1G
1478	default 0xC0000000
1479	depends on X86_32
1480
1481config HIGHMEM
1482	def_bool y
1483	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1484
1485config X86_PAE
1486	bool "PAE (Physical Address Extension) Support"
1487	depends on X86_32 && !HIGHMEM4G
1488	select PHYS_ADDR_T_64BIT
1489	select SWIOTLB
1490	help
1491	  PAE is required for NX support, and furthermore enables
1492	  larger swapspace support for non-overcommit purposes. It
1493	  has the cost of more pagetable lookup overhead, and also
1494	  consumes more pagetable space per process.
1495
1496config X86_5LEVEL
1497	bool "Enable 5-level page tables support"
1498	default y
1499	select DYNAMIC_MEMORY_LAYOUT
1500	select SPARSEMEM_VMEMMAP
1501	depends on X86_64
1502	help
1503	  5-level paging enables access to larger address space:
1504	  upto 128 PiB of virtual address space and 4 PiB of
1505	  physical address space.
1506
1507	  It will be supported by future Intel CPUs.
1508
1509	  A kernel with the option enabled can be booted on machines that
1510	  support 4- or 5-level paging.
1511
1512	  See Documentation/x86/x86_64/5level-paging.rst for more
1513	  information.
1514
1515	  Say N if unsure.
1516
1517config X86_DIRECT_GBPAGES
1518	def_bool y
1519	depends on X86_64
1520	help
1521	  Certain kernel features effectively disable kernel
1522	  linear 1 GB mappings (even if the CPU otherwise
1523	  supports them), so don't confuse the user by printing
1524	  that we have them enabled.
1525
1526config X86_CPA_STATISTICS
1527	bool "Enable statistic for Change Page Attribute"
1528	depends on DEBUG_FS
1529	help
1530	  Expose statistics about the Change Page Attribute mechanism, which
1531	  helps to determine the effectiveness of preserving large and huge
1532	  page mappings when mapping protections are changed.
1533
1534config X86_MEM_ENCRYPT
1535	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
1536	select DYNAMIC_PHYSICAL_MASK
1537	def_bool n
1538
1539config AMD_MEM_ENCRYPT
1540	bool "AMD Secure Memory Encryption (SME) support"
1541	depends on X86_64 && CPU_SUP_AMD
1542	select DMA_COHERENT_POOL
1543	select ARCH_USE_MEMREMAP_PROT
1544	select INSTRUCTION_DECODER
1545	select ARCH_HAS_CC_PLATFORM
1546	select X86_MEM_ENCRYPT
1547	help
1548	  Say yes to enable support for the encryption of system memory.
1549	  This requires an AMD processor that supports Secure Memory
1550	  Encryption (SME).
1551
1552config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1553	bool "Activate AMD Secure Memory Encryption (SME) by default"
1554	depends on AMD_MEM_ENCRYPT
1555	help
1556	  Say yes to have system memory encrypted by default if running on
1557	  an AMD processor that supports Secure Memory Encryption (SME).
1558
1559	  If set to Y, then the encryption of system memory can be
1560	  deactivated with the mem_encrypt=off command line option.
1561
1562	  If set to N, then the encryption of system memory can be
1563	  activated with the mem_encrypt=on command line option.
1564
1565# Common NUMA Features
1566config NUMA
1567	bool "NUMA Memory Allocation and Scheduler Support"
1568	depends on SMP
1569	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1570	default y if X86_BIGSMP
1571	select USE_PERCPU_NUMA_NODE_ID
1572	help
1573	  Enable NUMA (Non-Uniform Memory Access) support.
1574
1575	  The kernel will try to allocate memory used by a CPU on the
1576	  local memory controller of the CPU and add some more
1577	  NUMA awareness to the kernel.
1578
1579	  For 64-bit this is recommended if the system is Intel Core i7
1580	  (or later), AMD Opteron, or EM64T NUMA.
1581
1582	  For 32-bit this is only needed if you boot a 32-bit
1583	  kernel on a 64-bit NUMA platform.
1584
1585	  Otherwise, you should say N.
1586
1587config AMD_NUMA
1588	def_bool y
1589	prompt "Old style AMD Opteron NUMA detection"
1590	depends on X86_64 && NUMA && PCI
1591	help
1592	  Enable AMD NUMA node topology detection.  You should say Y here if
1593	  you have a multi processor AMD system. This uses an old method to
1594	  read the NUMA configuration directly from the builtin Northbridge
1595	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1596	  which also takes priority if both are compiled in.
1597
1598config X86_64_ACPI_NUMA
1599	def_bool y
1600	prompt "ACPI NUMA detection"
1601	depends on X86_64 && NUMA && ACPI && PCI
1602	select ACPI_NUMA
1603	help
1604	  Enable ACPI SRAT based node topology detection.
1605
1606config NUMA_EMU
1607	bool "NUMA emulation"
1608	depends on NUMA
1609	help
1610	  Enable NUMA emulation. A flat machine will be split
1611	  into virtual nodes when booted with "numa=fake=N", where N is the
1612	  number of nodes. This is only useful for debugging.
1613
1614config NODES_SHIFT
1615	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1616	range 1 10
1617	default "10" if MAXSMP
1618	default "6" if X86_64
1619	default "3"
1620	depends on NUMA
1621	help
1622	  Specify the maximum number of NUMA Nodes available on the target
1623	  system.  Increases memory reserved to accommodate various tables.
1624
1625config ARCH_FLATMEM_ENABLE
1626	def_bool y
1627	depends on X86_32 && !NUMA
1628
1629config ARCH_SPARSEMEM_ENABLE
1630	def_bool y
1631	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1632	select SPARSEMEM_STATIC if X86_32
1633	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1634
1635config ARCH_SPARSEMEM_DEFAULT
1636	def_bool X86_64 || (NUMA && X86_32)
1637
1638config ARCH_SELECT_MEMORY_MODEL
1639	def_bool y
1640	depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE
1641
1642config ARCH_MEMORY_PROBE
1643	bool "Enable sysfs memory/probe interface"
1644	depends on MEMORY_HOTPLUG
1645	help
1646	  This option enables a sysfs memory/probe interface for testing.
1647	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
1648	  If you are unsure how to answer this question, answer N.
1649
1650config ARCH_PROC_KCORE_TEXT
1651	def_bool y
1652	depends on X86_64 && PROC_KCORE
1653
1654config ILLEGAL_POINTER_VALUE
1655	hex
1656	default 0 if X86_32
1657	default 0xdead000000000000 if X86_64
1658
1659config X86_PMEM_LEGACY_DEVICE
1660	bool
1661
1662config X86_PMEM_LEGACY
1663	tristate "Support non-standard NVDIMMs and ADR protected memory"
1664	depends on PHYS_ADDR_T_64BIT
1665	depends on BLK_DEV
1666	select X86_PMEM_LEGACY_DEVICE
1667	select NUMA_KEEP_MEMINFO if NUMA
1668	select LIBNVDIMM
1669	help
1670	  Treat memory marked using the non-standard e820 type of 12 as used
1671	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1672	  The kernel will offer these regions to the 'pmem' driver so
1673	  they can be used for persistent storage.
1674
1675	  Say Y if unsure.
1676
1677config HIGHPTE
1678	bool "Allocate 3rd-level pagetables from highmem"
1679	depends on HIGHMEM
1680	help
1681	  The VM uses one page table entry for each page of physical memory.
1682	  For systems with a lot of RAM, this can be wasteful of precious
1683	  low memory.  Setting this option will put user-space page table
1684	  entries in high memory.
1685
1686config X86_CHECK_BIOS_CORRUPTION
1687	bool "Check for low memory corruption"
1688	help
1689	  Periodically check for memory corruption in low memory, which
1690	  is suspected to be caused by BIOS.  Even when enabled in the
1691	  configuration, it is disabled at runtime.  Enable it by
1692	  setting "memory_corruption_check=1" on the kernel command
1693	  line.  By default it scans the low 64k of memory every 60
1694	  seconds; see the memory_corruption_check_size and
1695	  memory_corruption_check_period parameters in
1696	  Documentation/admin-guide/kernel-parameters.rst to adjust this.
1697
1698	  When enabled with the default parameters, this option has
1699	  almost no overhead, as it reserves a relatively small amount
1700	  of memory and scans it infrequently.  It both detects corruption
1701	  and prevents it from affecting the running system.
1702
1703	  It is, however, intended as a diagnostic tool; if repeatable
1704	  BIOS-originated corruption always affects the same memory,
1705	  you can use memmap= to prevent the kernel from using that
1706	  memory.
1707
1708config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1709	bool "Set the default setting of memory_corruption_check"
1710	depends on X86_CHECK_BIOS_CORRUPTION
1711	default y
1712	help
1713	  Set whether the default state of memory_corruption_check is
1714	  on or off.
1715
1716config MATH_EMULATION
1717	bool
1718	depends on MODIFY_LDT_SYSCALL
1719	prompt "Math emulation" if X86_32 && (M486SX || MELAN)
1720	help
1721	  Linux can emulate a math coprocessor (used for floating point
1722	  operations) if you don't have one. 486DX and Pentium processors have
1723	  a math coprocessor built in, 486SX and 386 do not, unless you added
1724	  a 487DX or 387, respectively. (The messages during boot time can
1725	  give you some hints here ["man dmesg"].) Everyone needs either a
1726	  coprocessor or this emulation.
1727
1728	  If you don't have a math coprocessor, you need to say Y here; if you
1729	  say Y here even though you have a coprocessor, the coprocessor will
1730	  be used nevertheless. (This behavior can be changed with the kernel
1731	  command line option "no387", which comes handy if your coprocessor
1732	  is broken. Try "man bootparam" or see the documentation of your boot
1733	  loader (lilo or loadlin) about how to pass options to the kernel at
1734	  boot time.) This means that it is a good idea to say Y here if you
1735	  intend to use this kernel on different machines.
1736
1737	  More information about the internals of the Linux math coprocessor
1738	  emulation can be found in <file:arch/x86/math-emu/README>.
1739
1740	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1741	  kernel, it won't hurt.
1742
1743config MTRR
1744	def_bool y
1745	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1746	help
1747	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1748	  the Memory Type Range Registers (MTRRs) may be used to control
1749	  processor access to memory ranges. This is most useful if you have
1750	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1751	  allows bus write transfers to be combined into a larger transfer
1752	  before bursting over the PCI/AGP bus. This can increase performance
1753	  of image write operations 2.5 times or more. Saying Y here creates a
1754	  /proc/mtrr file which may be used to manipulate your processor's
1755	  MTRRs. Typically the X server should use this.
1756
1757	  This code has a reasonably generic interface so that similar
1758	  control registers on other processors can be easily supported
1759	  as well:
1760
1761	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1762	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1763	  these, the ARRs are used to emulate the MTRRs.
1764	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1765	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1766	  write-combining. All of these processors are supported by this code
1767	  and it makes sense to say Y here if you have one of them.
1768
1769	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1770	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1771	  can lead to all sorts of problems, so it's good to say Y here.
1772
1773	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1774	  just add about 9 KB to your kernel.
1775
1776	  See <file:Documentation/x86/mtrr.rst> for more information.
1777
1778config MTRR_SANITIZER
1779	def_bool y
1780	prompt "MTRR cleanup support"
1781	depends on MTRR
1782	help
1783	  Convert MTRR layout from continuous to discrete, so X drivers can
1784	  add writeback entries.
1785
1786	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1787	  The largest mtrr entry size for a continuous block can be set with
1788	  mtrr_chunk_size.
1789
1790	  If unsure, say Y.
1791
1792config MTRR_SANITIZER_ENABLE_DEFAULT
1793	int "MTRR cleanup enable value (0-1)"
1794	range 0 1
1795	default "0"
1796	depends on MTRR_SANITIZER
1797	help
1798	  Enable mtrr cleanup default value
1799
1800config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1801	int "MTRR cleanup spare reg num (0-7)"
1802	range 0 7
1803	default "1"
1804	depends on MTRR_SANITIZER
1805	help
1806	  mtrr cleanup spare entries default, it can be changed via
1807	  mtrr_spare_reg_nr=N on the kernel command line.
1808
1809config X86_PAT
1810	def_bool y
1811	prompt "x86 PAT support" if EXPERT
1812	depends on MTRR
1813	help
1814	  Use PAT attributes to setup page level cache control.
1815
1816	  PATs are the modern equivalents of MTRRs and are much more
1817	  flexible than MTRRs.
1818
1819	  Say N here if you see bootup problems (boot crash, boot hang,
1820	  spontaneous reboots) or a non-working video driver.
1821
1822	  If unsure, say Y.
1823
1824config ARCH_USES_PG_UNCACHED
1825	def_bool y
1826	depends on X86_PAT
1827
1828config X86_UMIP
1829	def_bool y
1830	prompt "User Mode Instruction Prevention" if EXPERT
1831	help
1832	  User Mode Instruction Prevention (UMIP) is a security feature in
1833	  some x86 processors. If enabled, a general protection fault is
1834	  issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1835	  executed in user mode. These instructions unnecessarily expose
1836	  information about the hardware state.
1837
1838	  The vast majority of applications do not use these instructions.
1839	  For the very few that do, software emulation is provided in
1840	  specific cases in protected and virtual-8086 modes. Emulated
1841	  results are dummy.
1842
1843config CC_HAS_IBT
1844	# GCC >= 9 and binutils >= 2.29
1845	# Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654
1846	# Clang/LLVM >= 14
1847	# https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f
1848	# https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332
1849	def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \
1850		  (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \
1851		  $(as-instr,endbr64)
1852
1853config X86_KERNEL_IBT
1854	prompt "Indirect Branch Tracking"
1855	def_bool y
1856	depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL
1857	# https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f
1858	depends on !LD_IS_LLD || LLD_VERSION >= 140000
1859	select OBJTOOL
1860	help
1861	  Build the kernel with support for Indirect Branch Tracking, a
1862	  hardware support course-grain forward-edge Control Flow Integrity
1863	  protection. It enforces that all indirect calls must land on
1864	  an ENDBR instruction, as such, the compiler will instrument the
1865	  code with them to make this happen.
1866
1867	  In addition to building the kernel with IBT, seal all functions that
1868	  are not indirect call targets, avoiding them ever becoming one.
1869
1870	  This requires LTO like objtool runs and will slow down the build. It
1871	  does significantly reduce the number of ENDBR instructions in the
1872	  kernel image.
1873
1874config X86_INTEL_MEMORY_PROTECTION_KEYS
1875	prompt "Memory Protection Keys"
1876	def_bool y
1877	# Note: only available in 64-bit mode
1878	depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
1879	select ARCH_USES_HIGH_VMA_FLAGS
1880	select ARCH_HAS_PKEYS
1881	help
1882	  Memory Protection Keys provides a mechanism for enforcing
1883	  page-based protections, but without requiring modification of the
1884	  page tables when an application changes protection domains.
1885
1886	  For details, see Documentation/core-api/protection-keys.rst
1887
1888	  If unsure, say y.
1889
1890choice
1891	prompt "TSX enable mode"
1892	depends on CPU_SUP_INTEL
1893	default X86_INTEL_TSX_MODE_OFF
1894	help
1895	  Intel's TSX (Transactional Synchronization Extensions) feature
1896	  allows to optimize locking protocols through lock elision which
1897	  can lead to a noticeable performance boost.
1898
1899	  On the other hand it has been shown that TSX can be exploited
1900	  to form side channel attacks (e.g. TAA) and chances are there
1901	  will be more of those attacks discovered in the future.
1902
1903	  Therefore TSX is not enabled by default (aka tsx=off). An admin
1904	  might override this decision by tsx=on the command line parameter.
1905	  Even with TSX enabled, the kernel will attempt to enable the best
1906	  possible TAA mitigation setting depending on the microcode available
1907	  for the particular machine.
1908
1909	  This option allows to set the default tsx mode between tsx=on, =off
1910	  and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1911	  details.
1912
1913	  Say off if not sure, auto if TSX is in use but it should be used on safe
1914	  platforms or on if TSX is in use and the security aspect of tsx is not
1915	  relevant.
1916
1917config X86_INTEL_TSX_MODE_OFF
1918	bool "off"
1919	help
1920	  TSX is disabled if possible - equals to tsx=off command line parameter.
1921
1922config X86_INTEL_TSX_MODE_ON
1923	bool "on"
1924	help
1925	  TSX is always enabled on TSX capable HW - equals the tsx=on command
1926	  line parameter.
1927
1928config X86_INTEL_TSX_MODE_AUTO
1929	bool "auto"
1930	help
1931	  TSX is enabled on TSX capable HW that is believed to be safe against
1932	  side channel attacks- equals the tsx=auto command line parameter.
1933endchoice
1934
1935config X86_SGX
1936	bool "Software Guard eXtensions (SGX)"
1937	depends on X86_64 && CPU_SUP_INTEL && X86_X2APIC
1938	depends on CRYPTO=y
1939	depends on CRYPTO_SHA256=y
1940	select SRCU
1941	select MMU_NOTIFIER
1942	select NUMA_KEEP_MEMINFO if NUMA
1943	select XARRAY_MULTI
1944	help
1945	  Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1946	  that can be used by applications to set aside private regions of code
1947	  and data, referred to as enclaves. An enclave's private memory can
1948	  only be accessed by code running within the enclave. Accesses from
1949	  outside the enclave, including other enclaves, are disallowed by
1950	  hardware.
1951
1952	  If unsure, say N.
1953
1954config EFI
1955	bool "EFI runtime service support"
1956	depends on ACPI
1957	select UCS2_STRING
1958	select EFI_RUNTIME_WRAPPERS
1959	select ARCH_USE_MEMREMAP_PROT
1960	help
1961	  This enables the kernel to use EFI runtime services that are
1962	  available (such as the EFI variable services).
1963
1964	  This option is only useful on systems that have EFI firmware.
1965	  In addition, you should use the latest ELILO loader available
1966	  at <http://elilo.sourceforge.net> in order to take advantage
1967	  of EFI runtime services. However, even with this option, the
1968	  resultant kernel should continue to boot on existing non-EFI
1969	  platforms.
1970
1971config EFI_STUB
1972	bool "EFI stub support"
1973	depends on EFI
1974	select RELOCATABLE
1975	help
1976	  This kernel feature allows a bzImage to be loaded directly
1977	  by EFI firmware without the use of a bootloader.
1978
1979	  See Documentation/admin-guide/efi-stub.rst for more information.
1980
1981config EFI_HANDOVER_PROTOCOL
1982	bool "EFI handover protocol (DEPRECATED)"
1983	depends on EFI_STUB
1984	default y
1985	help
1986	  Select this in order to include support for the deprecated EFI
1987	  handover protocol, which defines alternative entry points into the
1988	  EFI stub.  This is a practice that has no basis in the UEFI
1989	  specification, and requires a priori knowledge on the part of the
1990	  bootloader about Linux/x86 specific ways of passing the command line
1991	  and initrd, and where in memory those assets may be loaded.
1992
1993	  If in doubt, say Y. Even though the corresponding support is not
1994	  present in upstream GRUB or other bootloaders, most distros build
1995	  GRUB with numerous downstream patches applied, and may rely on the
1996	  handover protocol as as result.
1997
1998config EFI_MIXED
1999	bool "EFI mixed-mode support"
2000	depends on EFI_STUB && X86_64
2001	help
2002	  Enabling this feature allows a 64-bit kernel to be booted
2003	  on a 32-bit firmware, provided that your CPU supports 64-bit
2004	  mode.
2005
2006	  Note that it is not possible to boot a mixed-mode enabled
2007	  kernel via the EFI boot stub - a bootloader that supports
2008	  the EFI handover protocol must be used.
2009
2010	  If unsure, say N.
2011
2012config EFI_FAKE_MEMMAP
2013	bool "Enable EFI fake memory map"
2014	depends on EFI
2015	help
2016	  Saying Y here will enable "efi_fake_mem" boot option.  By specifying
2017	  this parameter, you can add arbitrary attribute to specific memory
2018	  range by updating original (firmware provided) EFI memmap.  This is
2019	  useful for debugging of EFI memmap related feature, e.g., Address
2020	  Range Mirroring feature.
2021
2022config EFI_MAX_FAKE_MEM
2023	int "maximum allowable number of ranges in efi_fake_mem boot option"
2024	depends on EFI_FAKE_MEMMAP
2025	range 1 128
2026	default 8
2027	help
2028	  Maximum allowable number of ranges in efi_fake_mem boot option.
2029	  Ranges can be set up to this value using comma-separated list.
2030	  The default value is 8.
2031
2032config EFI_RUNTIME_MAP
2033	bool "Export EFI runtime maps to sysfs" if EXPERT
2034	depends on EFI
2035	default KEXEC_CORE
2036	help
2037	  Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
2038	  That memory map is required by the 2nd kernel to set up EFI virtual
2039	  mappings after kexec, but can also be used for debugging purposes.
2040
2041	  See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map.
2042
2043source "kernel/Kconfig.hz"
2044
2045config KEXEC
2046	bool "kexec system call"
2047	select KEXEC_CORE
2048	help
2049	  kexec is a system call that implements the ability to shutdown your
2050	  current kernel, and to start another kernel.  It is like a reboot
2051	  but it is independent of the system firmware.   And like a reboot
2052	  you can start any kernel with it, not just Linux.
2053
2054	  The name comes from the similarity to the exec system call.
2055
2056	  It is an ongoing process to be certain the hardware in a machine
2057	  is properly shutdown, so do not be surprised if this code does not
2058	  initially work for you.  As of this writing the exact hardware
2059	  interface is strongly in flux, so no good recommendation can be
2060	  made.
2061
2062config KEXEC_FILE
2063	bool "kexec file based system call"
2064	select KEXEC_CORE
2065	select HAVE_IMA_KEXEC if IMA
2066	depends on X86_64
2067	depends on CRYPTO=y
2068	depends on CRYPTO_SHA256=y
2069	help
2070	  This is new version of kexec system call. This system call is
2071	  file based and takes file descriptors as system call argument
2072	  for kernel and initramfs as opposed to list of segments as
2073	  accepted by previous system call.
2074
2075config ARCH_HAS_KEXEC_PURGATORY
2076	def_bool KEXEC_FILE
2077
2078config KEXEC_SIG
2079	bool "Verify kernel signature during kexec_file_load() syscall"
2080	depends on KEXEC_FILE
2081	help
2082
2083	  This option makes the kexec_file_load() syscall check for a valid
2084	  signature of the kernel image.  The image can still be loaded without
2085	  a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2086	  there's a signature that we can check, then it must be valid.
2087
2088	  In addition to this option, you need to enable signature
2089	  verification for the corresponding kernel image type being
2090	  loaded in order for this to work.
2091
2092config KEXEC_SIG_FORCE
2093	bool "Require a valid signature in kexec_file_load() syscall"
2094	depends on KEXEC_SIG
2095	help
2096	  This option makes kernel signature verification mandatory for
2097	  the kexec_file_load() syscall.
2098
2099config KEXEC_BZIMAGE_VERIFY_SIG
2100	bool "Enable bzImage signature verification support"
2101	depends on KEXEC_SIG
2102	depends on SIGNED_PE_FILE_VERIFICATION
2103	select SYSTEM_TRUSTED_KEYRING
2104	help
2105	  Enable bzImage signature verification support.
2106
2107config CRASH_DUMP
2108	bool "kernel crash dumps"
2109	depends on X86_64 || (X86_32 && HIGHMEM)
2110	help
2111	  Generate crash dump after being started by kexec.
2112	  This should be normally only set in special crash dump kernels
2113	  which are loaded in the main kernel with kexec-tools into
2114	  a specially reserved region and then later executed after
2115	  a crash by kdump/kexec. The crash dump kernel must be compiled
2116	  to a memory address not used by the main kernel or BIOS using
2117	  PHYSICAL_START, or it must be built as a relocatable image
2118	  (CONFIG_RELOCATABLE=y).
2119	  For more details see Documentation/admin-guide/kdump/kdump.rst
2120
2121config KEXEC_JUMP
2122	bool "kexec jump"
2123	depends on KEXEC && HIBERNATION
2124	help
2125	  Jump between original kernel and kexeced kernel and invoke
2126	  code in physical address mode via KEXEC
2127
2128config PHYSICAL_START
2129	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2130	default "0x1000000"
2131	help
2132	  This gives the physical address where the kernel is loaded.
2133
2134	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2135	  bzImage will decompress itself to above physical address and
2136	  run from there. Otherwise, bzImage will run from the address where
2137	  it has been loaded by the boot loader and will ignore above physical
2138	  address.
2139
2140	  In normal kdump cases one does not have to set/change this option
2141	  as now bzImage can be compiled as a completely relocatable image
2142	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2143	  address. This option is mainly useful for the folks who don't want
2144	  to use a bzImage for capturing the crash dump and want to use a
2145	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
2146	  to be specifically compiled to run from a specific memory area
2147	  (normally a reserved region) and this option comes handy.
2148
2149	  So if you are using bzImage for capturing the crash dump,
2150	  leave the value here unchanged to 0x1000000 and set
2151	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
2152	  for capturing the crash dump change this value to start of
2153	  the reserved region.  In other words, it can be set based on
2154	  the "X" value as specified in the "crashkernel=YM@XM"
2155	  command line boot parameter passed to the panic-ed
2156	  kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
2157	  for more details about crash dumps.
2158
2159	  Usage of bzImage for capturing the crash dump is recommended as
2160	  one does not have to build two kernels. Same kernel can be used
2161	  as production kernel and capture kernel. Above option should have
2162	  gone away after relocatable bzImage support is introduced. But it
2163	  is present because there are users out there who continue to use
2164	  vmlinux for dump capture. This option should go away down the
2165	  line.
2166
2167	  Don't change this unless you know what you are doing.
2168
2169config RELOCATABLE
2170	bool "Build a relocatable kernel"
2171	default y
2172	help
2173	  This builds a kernel image that retains relocation information
2174	  so it can be loaded someplace besides the default 1MB.
2175	  The relocations tend to make the kernel binary about 10% larger,
2176	  but are discarded at runtime.
2177
2178	  One use is for the kexec on panic case where the recovery kernel
2179	  must live at a different physical address than the primary
2180	  kernel.
2181
2182	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2183	  it has been loaded at and the compile time physical address
2184	  (CONFIG_PHYSICAL_START) is used as the minimum location.
2185
2186config RANDOMIZE_BASE
2187	bool "Randomize the address of the kernel image (KASLR)"
2188	depends on RELOCATABLE
2189	default y
2190	help
2191	  In support of Kernel Address Space Layout Randomization (KASLR),
2192	  this randomizes the physical address at which the kernel image
2193	  is decompressed and the virtual address where the kernel
2194	  image is mapped, as a security feature that deters exploit
2195	  attempts relying on knowledge of the location of kernel
2196	  code internals.
2197
2198	  On 64-bit, the kernel physical and virtual addresses are
2199	  randomized separately. The physical address will be anywhere
2200	  between 16MB and the top of physical memory (up to 64TB). The
2201	  virtual address will be randomized from 16MB up to 1GB (9 bits
2202	  of entropy). Note that this also reduces the memory space
2203	  available to kernel modules from 1.5GB to 1GB.
2204
2205	  On 32-bit, the kernel physical and virtual addresses are
2206	  randomized together. They will be randomized from 16MB up to
2207	  512MB (8 bits of entropy).
2208
2209	  Entropy is generated using the RDRAND instruction if it is
2210	  supported. If RDTSC is supported, its value is mixed into
2211	  the entropy pool as well. If neither RDRAND nor RDTSC are
2212	  supported, then entropy is read from the i8254 timer. The
2213	  usable entropy is limited by the kernel being built using
2214	  2GB addressing, and that PHYSICAL_ALIGN must be at a
2215	  minimum of 2MB. As a result, only 10 bits of entropy are
2216	  theoretically possible, but the implementations are further
2217	  limited due to memory layouts.
2218
2219	  If unsure, say Y.
2220
2221# Relocation on x86 needs some additional build support
2222config X86_NEED_RELOCS
2223	def_bool y
2224	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2225
2226config PHYSICAL_ALIGN
2227	hex "Alignment value to which kernel should be aligned"
2228	default "0x200000"
2229	range 0x2000 0x1000000 if X86_32
2230	range 0x200000 0x1000000 if X86_64
2231	help
2232	  This value puts the alignment restrictions on physical address
2233	  where kernel is loaded and run from. Kernel is compiled for an
2234	  address which meets above alignment restriction.
2235
2236	  If bootloader loads the kernel at a non-aligned address and
2237	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2238	  address aligned to above value and run from there.
2239
2240	  If bootloader loads the kernel at a non-aligned address and
2241	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2242	  load address and decompress itself to the address it has been
2243	  compiled for and run from there. The address for which kernel is
2244	  compiled already meets above alignment restrictions. Hence the
2245	  end result is that kernel runs from a physical address meeting
2246	  above alignment restrictions.
2247
2248	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
2249	  this value must be a multiple of 0x200000.
2250
2251	  Don't change this unless you know what you are doing.
2252
2253config DYNAMIC_MEMORY_LAYOUT
2254	bool
2255	help
2256	  This option makes base addresses of vmalloc and vmemmap as well as
2257	  __PAGE_OFFSET movable during boot.
2258
2259config RANDOMIZE_MEMORY
2260	bool "Randomize the kernel memory sections"
2261	depends on X86_64
2262	depends on RANDOMIZE_BASE
2263	select DYNAMIC_MEMORY_LAYOUT
2264	default RANDOMIZE_BASE
2265	help
2266	  Randomizes the base virtual address of kernel memory sections
2267	  (physical memory mapping, vmalloc & vmemmap). This security feature
2268	  makes exploits relying on predictable memory locations less reliable.
2269
2270	  The order of allocations remains unchanged. Entropy is generated in
2271	  the same way as RANDOMIZE_BASE. Current implementation in the optimal
2272	  configuration have in average 30,000 different possible virtual
2273	  addresses for each memory section.
2274
2275	  If unsure, say Y.
2276
2277config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2278	hex "Physical memory mapping padding" if EXPERT
2279	depends on RANDOMIZE_MEMORY
2280	default "0xa" if MEMORY_HOTPLUG
2281	default "0x0"
2282	range 0x1 0x40 if MEMORY_HOTPLUG
2283	range 0x0 0x40
2284	help
2285	  Define the padding in terabytes added to the existing physical
2286	  memory size during kernel memory randomization. It is useful
2287	  for memory hotplug support but reduces the entropy available for
2288	  address randomization.
2289
2290	  If unsure, leave at the default value.
2291
2292config HOTPLUG_CPU
2293	def_bool y
2294	depends on SMP
2295
2296config BOOTPARAM_HOTPLUG_CPU0
2297	bool "Set default setting of cpu0_hotpluggable"
2298	depends on HOTPLUG_CPU
2299	help
2300	  Set whether default state of cpu0_hotpluggable is on or off.
2301
2302	  Say Y here to enable CPU0 hotplug by default. If this switch
2303	  is turned on, there is no need to give cpu0_hotplug kernel
2304	  parameter and the CPU0 hotplug feature is enabled by default.
2305
2306	  Please note: there are two known CPU0 dependencies if you want
2307	  to enable the CPU0 hotplug feature either by this switch or by
2308	  cpu0_hotplug kernel parameter.
2309
2310	  First, resume from hibernate or suspend always starts from CPU0.
2311	  So hibernate and suspend are prevented if CPU0 is offline.
2312
2313	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2314	  offline if any interrupt can not migrate out of CPU0. There may
2315	  be other CPU0 dependencies.
2316
2317	  Please make sure the dependencies are under your control before
2318	  you enable this feature.
2319
2320	  Say N if you don't want to enable CPU0 hotplug feature by default.
2321	  You still can enable the CPU0 hotplug feature at boot by kernel
2322	  parameter cpu0_hotplug.
2323
2324config DEBUG_HOTPLUG_CPU0
2325	def_bool n
2326	prompt "Debug CPU0 hotplug"
2327	depends on HOTPLUG_CPU
2328	help
2329	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2330	  soon as possible and boots up userspace with CPU0 offlined. User
2331	  can online CPU0 back after boot time.
2332
2333	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
2334	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2335	  compilation or giving cpu0_hotplug kernel parameter at boot.
2336
2337	  If unsure, say N.
2338
2339config COMPAT_VDSO
2340	def_bool n
2341	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2342	depends on COMPAT_32
2343	help
2344	  Certain buggy versions of glibc will crash if they are
2345	  presented with a 32-bit vDSO that is not mapped at the address
2346	  indicated in its segment table.
2347
2348	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2349	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2350	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
2351	  the only released version with the bug, but OpenSUSE 9
2352	  contains a buggy "glibc 2.3.2".
2353
2354	  The symptom of the bug is that everything crashes on startup, saying:
2355	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2356
2357	  Saying Y here changes the default value of the vdso32 boot
2358	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2359	  This works around the glibc bug but hurts performance.
2360
2361	  If unsure, say N: if you are compiling your own kernel, you
2362	  are unlikely to be using a buggy version of glibc.
2363
2364choice
2365	prompt "vsyscall table for legacy applications"
2366	depends on X86_64
2367	default LEGACY_VSYSCALL_XONLY
2368	help
2369	  Legacy user code that does not know how to find the vDSO expects
2370	  to be able to issue three syscalls by calling fixed addresses in
2371	  kernel space. Since this location is not randomized with ASLR,
2372	  it can be used to assist security vulnerability exploitation.
2373
2374	  This setting can be changed at boot time via the kernel command
2375	  line parameter vsyscall=[emulate|xonly|none].  Emulate mode
2376	  is deprecated and can only be enabled using the kernel command
2377	  line.
2378
2379	  On a system with recent enough glibc (2.14 or newer) and no
2380	  static binaries, you can say None without a performance penalty
2381	  to improve security.
2382
2383	  If unsure, select "Emulate execution only".
2384
2385	config LEGACY_VSYSCALL_XONLY
2386		bool "Emulate execution only"
2387		help
2388		  The kernel traps and emulates calls into the fixed vsyscall
2389		  address mapping and does not allow reads.  This
2390		  configuration is recommended when userspace might use the
2391		  legacy vsyscall area but support for legacy binary
2392		  instrumentation of legacy code is not needed.  It mitigates
2393		  certain uses of the vsyscall area as an ASLR-bypassing
2394		  buffer.
2395
2396	config LEGACY_VSYSCALL_NONE
2397		bool "None"
2398		help
2399		  There will be no vsyscall mapping at all. This will
2400		  eliminate any risk of ASLR bypass due to the vsyscall
2401		  fixed address mapping. Attempts to use the vsyscalls
2402		  will be reported to dmesg, so that either old or
2403		  malicious userspace programs can be identified.
2404
2405endchoice
2406
2407config CMDLINE_BOOL
2408	bool "Built-in kernel command line"
2409	help
2410	  Allow for specifying boot arguments to the kernel at
2411	  build time.  On some systems (e.g. embedded ones), it is
2412	  necessary or convenient to provide some or all of the
2413	  kernel boot arguments with the kernel itself (that is,
2414	  to not rely on the boot loader to provide them.)
2415
2416	  To compile command line arguments into the kernel,
2417	  set this option to 'Y', then fill in the
2418	  boot arguments in CONFIG_CMDLINE.
2419
2420	  Systems with fully functional boot loaders (i.e. non-embedded)
2421	  should leave this option set to 'N'.
2422
2423config CMDLINE
2424	string "Built-in kernel command string"
2425	depends on CMDLINE_BOOL
2426	default ""
2427	help
2428	  Enter arguments here that should be compiled into the kernel
2429	  image and used at boot time.  If the boot loader provides a
2430	  command line at boot time, it is appended to this string to
2431	  form the full kernel command line, when the system boots.
2432
2433	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2434	  change this behavior.
2435
2436	  In most cases, the command line (whether built-in or provided
2437	  by the boot loader) should specify the device for the root
2438	  file system.
2439
2440config CMDLINE_OVERRIDE
2441	bool "Built-in command line overrides boot loader arguments"
2442	depends on CMDLINE_BOOL && CMDLINE != ""
2443	help
2444	  Set this option to 'Y' to have the kernel ignore the boot loader
2445	  command line, and use ONLY the built-in command line.
2446
2447	  This is used to work around broken boot loaders.  This should
2448	  be set to 'N' under normal conditions.
2449
2450config MODIFY_LDT_SYSCALL
2451	bool "Enable the LDT (local descriptor table)" if EXPERT
2452	default y
2453	help
2454	  Linux can allow user programs to install a per-process x86
2455	  Local Descriptor Table (LDT) using the modify_ldt(2) system
2456	  call.  This is required to run 16-bit or segmented code such as
2457	  DOSEMU or some Wine programs.  It is also used by some very old
2458	  threading libraries.
2459
2460	  Enabling this feature adds a small amount of overhead to
2461	  context switches and increases the low-level kernel attack
2462	  surface.  Disabling it removes the modify_ldt(2) system call.
2463
2464	  Saying 'N' here may make sense for embedded or server kernels.
2465
2466config STRICT_SIGALTSTACK_SIZE
2467	bool "Enforce strict size checking for sigaltstack"
2468	depends on DYNAMIC_SIGFRAME
2469	help
2470	  For historical reasons MINSIGSTKSZ is a constant which became
2471	  already too small with AVX512 support. Add a mechanism to
2472	  enforce strict checking of the sigaltstack size against the
2473	  real size of the FPU frame. This option enables the check
2474	  by default. It can also be controlled via the kernel command
2475	  line option 'strict_sas_size' independent of this config
2476	  switch. Enabling it might break existing applications which
2477	  allocate a too small sigaltstack but 'work' because they
2478	  never get a signal delivered.
2479
2480	  Say 'N' unless you want to really enforce this check.
2481
2482source "kernel/livepatch/Kconfig"
2483
2484endmenu
2485
2486config CC_HAS_SLS
2487	def_bool $(cc-option,-mharden-sls=all)
2488
2489config CC_HAS_RETURN_THUNK
2490	def_bool $(cc-option,-mfunction-return=thunk-extern)
2491
2492config CC_HAS_ENTRY_PADDING
2493	def_bool $(cc-option,-fpatchable-function-entry=16,16)
2494
2495config FUNCTION_PADDING_CFI
2496	int
2497	default 59 if FUNCTION_ALIGNMENT_64B
2498	default 27 if FUNCTION_ALIGNMENT_32B
2499	default 11 if FUNCTION_ALIGNMENT_16B
2500	default  3 if FUNCTION_ALIGNMENT_8B
2501	default  0
2502
2503# Basically: FUNCTION_ALIGNMENT - 5*CFI_CLANG
2504# except Kconfig can't do arithmetic :/
2505config FUNCTION_PADDING_BYTES
2506	int
2507	default FUNCTION_PADDING_CFI if CFI_CLANG
2508	default FUNCTION_ALIGNMENT
2509
2510config CALL_PADDING
2511	def_bool n
2512	depends on CC_HAS_ENTRY_PADDING && OBJTOOL
2513	select FUNCTION_ALIGNMENT_16B
2514
2515config FINEIBT
2516	def_bool y
2517	depends on X86_KERNEL_IBT && CFI_CLANG && RETPOLINE
2518	select CALL_PADDING
2519
2520config HAVE_CALL_THUNKS
2521	def_bool y
2522	depends on CC_HAS_ENTRY_PADDING && RETHUNK && OBJTOOL
2523
2524config CALL_THUNKS
2525	def_bool n
2526	select CALL_PADDING
2527
2528config PREFIX_SYMBOLS
2529	def_bool y
2530	depends on CALL_PADDING && !CFI_CLANG
2531
2532menuconfig SPECULATION_MITIGATIONS
2533	bool "Mitigations for speculative execution vulnerabilities"
2534	default y
2535	help
2536	  Say Y here to enable options which enable mitigations for
2537	  speculative execution hardware vulnerabilities.
2538
2539	  If you say N, all mitigations will be disabled. You really
2540	  should know what you are doing to say so.
2541
2542if SPECULATION_MITIGATIONS
2543
2544config PAGE_TABLE_ISOLATION
2545	bool "Remove the kernel mapping in user mode"
2546	default y
2547	depends on (X86_64 || X86_PAE)
2548	help
2549	  This feature reduces the number of hardware side channels by
2550	  ensuring that the majority of kernel addresses are not mapped
2551	  into userspace.
2552
2553	  See Documentation/x86/pti.rst for more details.
2554
2555config RETPOLINE
2556	bool "Avoid speculative indirect branches in kernel"
2557	select OBJTOOL if HAVE_OBJTOOL
2558	default y
2559	help
2560	  Compile kernel with the retpoline compiler options to guard against
2561	  kernel-to-user data leaks by avoiding speculative indirect
2562	  branches. Requires a compiler with -mindirect-branch=thunk-extern
2563	  support for full protection. The kernel may run slower.
2564
2565config RETHUNK
2566	bool "Enable return-thunks"
2567	depends on RETPOLINE && CC_HAS_RETURN_THUNK
2568	select OBJTOOL if HAVE_OBJTOOL
2569	default y if X86_64
2570	help
2571	  Compile the kernel with the return-thunks compiler option to guard
2572	  against kernel-to-user data leaks by avoiding return speculation.
2573	  Requires a compiler with -mfunction-return=thunk-extern
2574	  support for full protection. The kernel may run slower.
2575
2576config CPU_UNRET_ENTRY
2577	bool "Enable UNRET on kernel entry"
2578	depends on CPU_SUP_AMD && RETHUNK && X86_64
2579	default y
2580	help
2581	  Compile the kernel with support for the retbleed=unret mitigation.
2582
2583config CALL_DEPTH_TRACKING
2584	bool "Mitigate RSB underflow with call depth tracking"
2585	depends on CPU_SUP_INTEL && HAVE_CALL_THUNKS
2586	select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
2587	select CALL_THUNKS
2588	default y
2589	help
2590	  Compile the kernel with call depth tracking to mitigate the Intel
2591	  SKL Return-Speculation-Buffer (RSB) underflow issue. The
2592	  mitigation is off by default and needs to be enabled on the
2593	  kernel command line via the retbleed=stuff option. For
2594	  non-affected systems the overhead of this option is marginal as
2595	  the call depth tracking is using run-time generated call thunks
2596	  in a compiler generated padding area and call patching. This
2597	  increases text size by ~5%. For non affected systems this space
2598	  is unused. On affected SKL systems this results in a significant
2599	  performance gain over the IBRS mitigation.
2600
2601config CALL_THUNKS_DEBUG
2602	bool "Enable call thunks and call depth tracking debugging"
2603	depends on CALL_DEPTH_TRACKING
2604	select FUNCTION_ALIGNMENT_32B
2605	default n
2606	help
2607	  Enable call/ret counters for imbalance detection and build in
2608	  a noisy dmesg about callthunks generation and call patching for
2609	  trouble shooting. The debug prints need to be enabled on the
2610	  kernel command line with 'debug-callthunks'.
2611	  Only enable this, when you are debugging call thunks as this
2612	  creates a noticable runtime overhead. If unsure say N.
2613
2614config CPU_IBPB_ENTRY
2615	bool "Enable IBPB on kernel entry"
2616	depends on CPU_SUP_AMD && X86_64
2617	default y
2618	help
2619	  Compile the kernel with support for the retbleed=ibpb mitigation.
2620
2621config CPU_IBRS_ENTRY
2622	bool "Enable IBRS on kernel entry"
2623	depends on CPU_SUP_INTEL && X86_64
2624	default y
2625	help
2626	  Compile the kernel with support for the spectre_v2=ibrs mitigation.
2627	  This mitigates both spectre_v2 and retbleed at great cost to
2628	  performance.
2629
2630config SLS
2631	bool "Mitigate Straight-Line-Speculation"
2632	depends on CC_HAS_SLS && X86_64
2633	select OBJTOOL if HAVE_OBJTOOL
2634	default n
2635	help
2636	  Compile the kernel with straight-line-speculation options to guard
2637	  against straight line speculation. The kernel image might be slightly
2638	  larger.
2639
2640endif
2641
2642config ARCH_HAS_ADD_PAGES
2643	def_bool y
2644	depends on ARCH_ENABLE_MEMORY_HOTPLUG
2645
2646config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2647	def_bool y
2648
2649menu "Power management and ACPI options"
2650
2651config ARCH_HIBERNATION_HEADER
2652	def_bool y
2653	depends on HIBERNATION
2654
2655source "kernel/power/Kconfig"
2656
2657source "drivers/acpi/Kconfig"
2658
2659config X86_APM_BOOT
2660	def_bool y
2661	depends on APM
2662
2663menuconfig APM
2664	tristate "APM (Advanced Power Management) BIOS support"
2665	depends on X86_32 && PM_SLEEP
2666	help
2667	  APM is a BIOS specification for saving power using several different
2668	  techniques. This is mostly useful for battery powered laptops with
2669	  APM compliant BIOSes. If you say Y here, the system time will be
2670	  reset after a RESUME operation, the /proc/apm device will provide
2671	  battery status information, and user-space programs will receive
2672	  notification of APM "events" (e.g. battery status change).
2673
2674	  If you select "Y" here, you can disable actual use of the APM
2675	  BIOS by passing the "apm=off" option to the kernel at boot time.
2676
2677	  Note that the APM support is almost completely disabled for
2678	  machines with more than one CPU.
2679
2680	  In order to use APM, you will need supporting software. For location
2681	  and more information, read <file:Documentation/power/apm-acpi.rst>
2682	  and the Battery Powered Linux mini-HOWTO, available from
2683	  <http://www.tldp.org/docs.html#howto>.
2684
2685	  This driver does not spin down disk drives (see the hdparm(8)
2686	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2687	  VESA-compliant "green" monitors.
2688
2689	  This driver does not support the TI 4000M TravelMate and the ACER
2690	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2691	  desktop machines also don't have compliant BIOSes, and this driver
2692	  may cause those machines to panic during the boot phase.
2693
2694	  Generally, if you don't have a battery in your machine, there isn't
2695	  much point in using this driver and you should say N. If you get
2696	  random kernel OOPSes or reboots that don't seem to be related to
2697	  anything, try disabling/enabling this option (or disabling/enabling
2698	  APM in your BIOS).
2699
2700	  Some other things you should try when experiencing seemingly random,
2701	  "weird" problems:
2702
2703	  1) make sure that you have enough swap space and that it is
2704	  enabled.
2705	  2) pass the "idle=poll" option to the kernel
2706	  3) switch on floating point emulation in the kernel and pass
2707	  the "no387" option to the kernel
2708	  4) pass the "floppy=nodma" option to the kernel
2709	  5) pass the "mem=4M" option to the kernel (thereby disabling
2710	  all but the first 4 MB of RAM)
2711	  6) make sure that the CPU is not over clocked.
2712	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2713	  8) disable the cache from your BIOS settings
2714	  9) install a fan for the video card or exchange video RAM
2715	  10) install a better fan for the CPU
2716	  11) exchange RAM chips
2717	  12) exchange the motherboard.
2718
2719	  To compile this driver as a module, choose M here: the
2720	  module will be called apm.
2721
2722if APM
2723
2724config APM_IGNORE_USER_SUSPEND
2725	bool "Ignore USER SUSPEND"
2726	help
2727	  This option will ignore USER SUSPEND requests. On machines with a
2728	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2729	  series notebooks, it is necessary to say Y because of a BIOS bug.
2730
2731config APM_DO_ENABLE
2732	bool "Enable PM at boot time"
2733	help
2734	  Enable APM features at boot time. From page 36 of the APM BIOS
2735	  specification: "When disabled, the APM BIOS does not automatically
2736	  power manage devices, enter the Standby State, enter the Suspend
2737	  State, or take power saving steps in response to CPU Idle calls."
2738	  This driver will make CPU Idle calls when Linux is idle (unless this
2739	  feature is turned off -- see "Do CPU IDLE calls", below). This
2740	  should always save battery power, but more complicated APM features
2741	  will be dependent on your BIOS implementation. You may need to turn
2742	  this option off if your computer hangs at boot time when using APM
2743	  support, or if it beeps continuously instead of suspending. Turn
2744	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2745	  T400CDT. This is off by default since most machines do fine without
2746	  this feature.
2747
2748config APM_CPU_IDLE
2749	depends on CPU_IDLE
2750	bool "Make CPU Idle calls when idle"
2751	help
2752	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2753	  On some machines, this can activate improved power savings, such as
2754	  a slowed CPU clock rate, when the machine is idle. These idle calls
2755	  are made after the idle loop has run for some length of time (e.g.,
2756	  333 mS). On some machines, this will cause a hang at boot time or
2757	  whenever the CPU becomes idle. (On machines with more than one CPU,
2758	  this option does nothing.)
2759
2760config APM_DISPLAY_BLANK
2761	bool "Enable console blanking using APM"
2762	help
2763	  Enable console blanking using the APM. Some laptops can use this to
2764	  turn off the LCD backlight when the screen blanker of the Linux
2765	  virtual console blanks the screen. Note that this is only used by
2766	  the virtual console screen blanker, and won't turn off the backlight
2767	  when using the X Window system. This also doesn't have anything to
2768	  do with your VESA-compliant power-saving monitor. Further, this
2769	  option doesn't work for all laptops -- it might not turn off your
2770	  backlight at all, or it might print a lot of errors to the console,
2771	  especially if you are using gpm.
2772
2773config APM_ALLOW_INTS
2774	bool "Allow interrupts during APM BIOS calls"
2775	help
2776	  Normally we disable external interrupts while we are making calls to
2777	  the APM BIOS as a measure to lessen the effects of a badly behaving
2778	  BIOS implementation.  The BIOS should reenable interrupts if it
2779	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2780	  many of the newer IBM Thinkpads.  If you experience hangs when you
2781	  suspend, try setting this to Y.  Otherwise, say N.
2782
2783endif # APM
2784
2785source "drivers/cpufreq/Kconfig"
2786
2787source "drivers/cpuidle/Kconfig"
2788
2789source "drivers/idle/Kconfig"
2790
2791endmenu
2792
2793menu "Bus options (PCI etc.)"
2794
2795choice
2796	prompt "PCI access mode"
2797	depends on X86_32 && PCI
2798	default PCI_GOANY
2799	help
2800	  On PCI systems, the BIOS can be used to detect the PCI devices and
2801	  determine their configuration. However, some old PCI motherboards
2802	  have BIOS bugs and may crash if this is done. Also, some embedded
2803	  PCI-based systems don't have any BIOS at all. Linux can also try to
2804	  detect the PCI hardware directly without using the BIOS.
2805
2806	  With this option, you can specify how Linux should detect the
2807	  PCI devices. If you choose "BIOS", the BIOS will be used,
2808	  if you choose "Direct", the BIOS won't be used, and if you
2809	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2810	  If you choose "Any", the kernel will try MMCONFIG, then the
2811	  direct access method and falls back to the BIOS if that doesn't
2812	  work. If unsure, go with the default, which is "Any".
2813
2814config PCI_GOBIOS
2815	bool "BIOS"
2816
2817config PCI_GOMMCONFIG
2818	bool "MMConfig"
2819
2820config PCI_GODIRECT
2821	bool "Direct"
2822
2823config PCI_GOOLPC
2824	bool "OLPC XO-1"
2825	depends on OLPC
2826
2827config PCI_GOANY
2828	bool "Any"
2829
2830endchoice
2831
2832config PCI_BIOS
2833	def_bool y
2834	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2835
2836# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2837config PCI_DIRECT
2838	def_bool y
2839	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2840
2841config PCI_MMCONFIG
2842	bool "Support mmconfig PCI config space access" if X86_64
2843	default y
2844	depends on PCI && (ACPI || JAILHOUSE_GUEST)
2845	depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2846
2847config PCI_OLPC
2848	def_bool y
2849	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2850
2851config PCI_XEN
2852	def_bool y
2853	depends on PCI && XEN
2854
2855config MMCONF_FAM10H
2856	def_bool y
2857	depends on X86_64 && PCI_MMCONFIG && ACPI
2858
2859config PCI_CNB20LE_QUIRK
2860	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2861	depends on PCI
2862	help
2863	  Read the PCI windows out of the CNB20LE host bridge. This allows
2864	  PCI hotplug to work on systems with the CNB20LE chipset which do
2865	  not have ACPI.
2866
2867	  There's no public spec for this chipset, and this functionality
2868	  is known to be incomplete.
2869
2870	  You should say N unless you know you need this.
2871
2872config ISA_BUS
2873	bool "ISA bus support on modern systems" if EXPERT
2874	help
2875	  Expose ISA bus device drivers and options available for selection and
2876	  configuration. Enable this option if your target machine has an ISA
2877	  bus. ISA is an older system, displaced by PCI and newer bus
2878	  architectures -- if your target machine is modern, it probably does
2879	  not have an ISA bus.
2880
2881	  If unsure, say N.
2882
2883# x86_64 have no ISA slots, but can have ISA-style DMA.
2884config ISA_DMA_API
2885	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2886	default y
2887	help
2888	  Enables ISA-style DMA support for devices requiring such controllers.
2889	  If unsure, say Y.
2890
2891if X86_32
2892
2893config ISA
2894	bool "ISA support"
2895	help
2896	  Find out whether you have ISA slots on your motherboard.  ISA is the
2897	  name of a bus system, i.e. the way the CPU talks to the other stuff
2898	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2899	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2900	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2901
2902config SCx200
2903	tristate "NatSemi SCx200 support"
2904	help
2905	  This provides basic support for National Semiconductor's
2906	  (now AMD's) Geode processors.  The driver probes for the
2907	  PCI-IDs of several on-chip devices, so its a good dependency
2908	  for other scx200_* drivers.
2909
2910	  If compiled as a module, the driver is named scx200.
2911
2912config SCx200HR_TIMER
2913	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2914	depends on SCx200
2915	default y
2916	help
2917	  This driver provides a clocksource built upon the on-chip
2918	  27MHz high-resolution timer.  Its also a workaround for
2919	  NSC Geode SC-1100's buggy TSC, which loses time when the
2920	  processor goes idle (as is done by the scheduler).  The
2921	  other workaround is idle=poll boot option.
2922
2923config OLPC
2924	bool "One Laptop Per Child support"
2925	depends on !X86_PAE
2926	select GPIOLIB
2927	select OF
2928	select OF_PROMTREE
2929	select IRQ_DOMAIN
2930	select OLPC_EC
2931	help
2932	  Add support for detecting the unique features of the OLPC
2933	  XO hardware.
2934
2935config OLPC_XO1_PM
2936	bool "OLPC XO-1 Power Management"
2937	depends on OLPC && MFD_CS5535=y && PM_SLEEP
2938	help
2939	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2940
2941config OLPC_XO1_RTC
2942	bool "OLPC XO-1 Real Time Clock"
2943	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2944	help
2945	  Add support for the XO-1 real time clock, which can be used as a
2946	  programmable wakeup source.
2947
2948config OLPC_XO1_SCI
2949	bool "OLPC XO-1 SCI extras"
2950	depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2951	depends on INPUT=y
2952	select POWER_SUPPLY
2953	help
2954	  Add support for SCI-based features of the OLPC XO-1 laptop:
2955	   - EC-driven system wakeups
2956	   - Power button
2957	   - Ebook switch
2958	   - Lid switch
2959	   - AC adapter status updates
2960	   - Battery status updates
2961
2962config OLPC_XO15_SCI
2963	bool "OLPC XO-1.5 SCI extras"
2964	depends on OLPC && ACPI
2965	select POWER_SUPPLY
2966	help
2967	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2968	   - EC-driven system wakeups
2969	   - AC adapter status updates
2970	   - Battery status updates
2971
2972config ALIX
2973	bool "PCEngines ALIX System Support (LED setup)"
2974	select GPIOLIB
2975	help
2976	  This option enables system support for the PCEngines ALIX.
2977	  At present this just sets up LEDs for GPIO control on
2978	  ALIX2/3/6 boards.  However, other system specific setup should
2979	  get added here.
2980
2981	  Note: You must still enable the drivers for GPIO and LED support
2982	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2983
2984	  Note: You have to set alix.force=1 for boards with Award BIOS.
2985
2986config NET5501
2987	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2988	select GPIOLIB
2989	help
2990	  This option enables system support for the Soekris Engineering net5501.
2991
2992config GEOS
2993	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2994	select GPIOLIB
2995	depends on DMI
2996	help
2997	  This option enables system support for the Traverse Technologies GEOS.
2998
2999config TS5500
3000	bool "Technologic Systems TS-5500 platform support"
3001	depends on MELAN
3002	select CHECK_SIGNATURE
3003	select NEW_LEDS
3004	select LEDS_CLASS
3005	help
3006	  This option enables system support for the Technologic Systems TS-5500.
3007
3008endif # X86_32
3009
3010config AMD_NB
3011	def_bool y
3012	depends on CPU_SUP_AMD && PCI
3013
3014endmenu
3015
3016menu "Binary Emulations"
3017
3018config IA32_EMULATION
3019	bool "IA32 Emulation"
3020	depends on X86_64
3021	select ARCH_WANT_OLD_COMPAT_IPC
3022	select BINFMT_ELF
3023	select COMPAT_OLD_SIGACTION
3024	help
3025	  Include code to run legacy 32-bit programs under a
3026	  64-bit kernel. You should likely turn this on, unless you're
3027	  100% sure that you don't have any 32-bit programs left.
3028
3029config X86_X32_ABI
3030	bool "x32 ABI for 64-bit mode"
3031	depends on X86_64
3032	# llvm-objcopy does not convert x86_64 .note.gnu.property or
3033	# compressed debug sections to x86_x32 properly:
3034	# https://github.com/ClangBuiltLinux/linux/issues/514
3035	# https://github.com/ClangBuiltLinux/linux/issues/1141
3036	depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm)
3037	help
3038	  Include code to run binaries for the x32 native 32-bit ABI
3039	  for 64-bit processors.  An x32 process gets access to the
3040	  full 64-bit register file and wide data path while leaving
3041	  pointers at 32 bits for smaller memory footprint.
3042
3043config COMPAT_32
3044	def_bool y
3045	depends on IA32_EMULATION || X86_32
3046	select HAVE_UID16
3047	select OLD_SIGSUSPEND3
3048
3049config COMPAT
3050	def_bool y
3051	depends on IA32_EMULATION || X86_X32_ABI
3052
3053config COMPAT_FOR_U64_ALIGNMENT
3054	def_bool y
3055	depends on COMPAT
3056
3057endmenu
3058
3059config HAVE_ATOMIC_IOMAP
3060	def_bool y
3061	depends on X86_32
3062
3063source "arch/x86/kvm/Kconfig"
3064
3065source "arch/x86/Kconfig.assembler"
3066