xref: /openbmc/linux/arch/x86/Kconfig (revision 4f3db074)
1# Select 32 or 64 bit
2config 64BIT
3	bool "64-bit kernel" if ARCH = "x86"
4	default ARCH != "i386"
5	---help---
6	  Say yes to build a 64-bit kernel - formerly known as x86_64
7	  Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
10	def_bool y
11	depends on !64BIT
12	select CLKSRC_I8253
13	select HAVE_UID16
14
15config X86_64
16	def_bool y
17	depends on 64BIT
18	select X86_DEV_DMA_OPS
19	select ARCH_USE_CMPXCHG_LOCKREF
20	select HAVE_LIVEPATCH
21
22### Arch settings
23config X86
24	def_bool y
25	select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
26	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
27	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
28	select ARCH_HAS_FAST_MULTIPLIER
29	select ARCH_HAS_GCOV_PROFILE_ALL
30	select ARCH_MIGHT_HAVE_PC_PARPORT
31	select ARCH_MIGHT_HAVE_PC_SERIO
32	select HAVE_AOUT if X86_32
33	select HAVE_UNSTABLE_SCHED_CLOCK
34	select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
35	select ARCH_SUPPORTS_INT128 if X86_64
36	select HAVE_IDE
37	select HAVE_OPROFILE
38	select HAVE_PCSPKR_PLATFORM
39	select HAVE_PERF_EVENTS
40	select HAVE_IOREMAP_PROT
41	select HAVE_KPROBES
42	select HAVE_MEMBLOCK
43	select HAVE_MEMBLOCK_NODE_MAP
44	select ARCH_DISCARD_MEMBLOCK
45	select ARCH_WANT_OPTIONAL_GPIOLIB
46	select ARCH_WANT_FRAME_POINTERS
47	select HAVE_DMA_ATTRS
48	select HAVE_DMA_CONTIGUOUS
49	select HAVE_KRETPROBES
50	select GENERIC_EARLY_IOREMAP
51	select HAVE_OPTPROBES
52	select HAVE_KPROBES_ON_FTRACE
53	select HAVE_FTRACE_MCOUNT_RECORD
54	select HAVE_FENTRY if X86_64
55	select HAVE_C_RECORDMCOUNT
56	select HAVE_DYNAMIC_FTRACE
57	select HAVE_DYNAMIC_FTRACE_WITH_REGS
58	select HAVE_FUNCTION_TRACER
59	select HAVE_FUNCTION_GRAPH_TRACER
60	select HAVE_FUNCTION_GRAPH_FP_TEST
61	select HAVE_SYSCALL_TRACEPOINTS
62	select SYSCTL_EXCEPTION_TRACE
63	select HAVE_KVM
64	select HAVE_ARCH_KGDB
65	select HAVE_ARCH_TRACEHOOK
66	select HAVE_GENERIC_DMA_COHERENT if X86_32
67	select HAVE_EFFICIENT_UNALIGNED_ACCESS
68	select USER_STACKTRACE_SUPPORT
69	select HAVE_REGS_AND_STACK_ACCESS_API
70	select HAVE_DMA_API_DEBUG
71	select HAVE_KERNEL_GZIP
72	select HAVE_KERNEL_BZIP2
73	select HAVE_KERNEL_LZMA
74	select HAVE_KERNEL_XZ
75	select HAVE_KERNEL_LZO
76	select HAVE_KERNEL_LZ4
77	select HAVE_HW_BREAKPOINT
78	select HAVE_MIXED_BREAKPOINTS_REGS
79	select PERF_EVENTS
80	select HAVE_PERF_EVENTS_NMI
81	select HAVE_PERF_REGS
82	select HAVE_PERF_USER_STACK_DUMP
83	select HAVE_DEBUG_KMEMLEAK
84	select ANON_INODES
85	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
86	select HAVE_CMPXCHG_LOCAL
87	select HAVE_CMPXCHG_DOUBLE
88	select HAVE_ARCH_KMEMCHECK
89	select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
90	select HAVE_USER_RETURN_NOTIFIER
91	select ARCH_HAS_ELF_RANDOMIZE
92	select HAVE_ARCH_JUMP_LABEL
93	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
94	select SPARSE_IRQ
95	select GENERIC_FIND_FIRST_BIT
96	select GENERIC_IRQ_PROBE
97	select GENERIC_PENDING_IRQ if SMP
98	select GENERIC_IRQ_SHOW
99	select GENERIC_CLOCKEVENTS_MIN_ADJUST
100	select IRQ_FORCED_THREADING
101	select HAVE_BPF_JIT if X86_64
102	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
103	select HAVE_ARCH_HUGE_VMAP if X86_64 || (X86_32 && X86_PAE)
104	select ARCH_HAS_SG_CHAIN
105	select CLKEVT_I8253
106	select ARCH_HAVE_NMI_SAFE_CMPXCHG
107	select GENERIC_IOMAP
108	select DCACHE_WORD_ACCESS
109	select GENERIC_SMP_IDLE_THREAD
110	select ARCH_WANT_IPC_PARSE_VERSION if X86_32
111	select HAVE_ARCH_SECCOMP_FILTER
112	select BUILDTIME_EXTABLE_SORT
113	select GENERIC_CMOS_UPDATE
114	select HAVE_ARCH_SOFT_DIRTY if X86_64
115	select CLOCKSOURCE_WATCHDOG
116	select GENERIC_CLOCKEVENTS
117	select ARCH_CLOCKSOURCE_DATA
118	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
119	select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
120	select GENERIC_TIME_VSYSCALL
121	select GENERIC_STRNCPY_FROM_USER
122	select GENERIC_STRNLEN_USER
123	select HAVE_CONTEXT_TRACKING if X86_64
124	select HAVE_IRQ_TIME_ACCOUNTING
125	select VIRT_TO_BUS
126	select MODULES_USE_ELF_REL if X86_32
127	select MODULES_USE_ELF_RELA if X86_64
128	select CLONE_BACKWARDS if X86_32
129	select ARCH_USE_BUILTIN_BSWAP
130	select ARCH_USE_QUEUE_RWLOCK
131	select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
132	select OLD_SIGACTION if X86_32
133	select COMPAT_OLD_SIGACTION if IA32_EMULATION
134	select RTC_LIB
135	select HAVE_DEBUG_STACKOVERFLOW
136	select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
137	select HAVE_CC_STACKPROTECTOR
138	select GENERIC_CPU_AUTOPROBE
139	select HAVE_ARCH_AUDITSYSCALL
140	select ARCH_SUPPORTS_ATOMIC_RMW
141	select HAVE_ACPI_APEI if ACPI
142	select HAVE_ACPI_APEI_NMI if ACPI
143	select ACPI_LEGACY_TABLES_LOOKUP if ACPI
144	select X86_FEATURE_NAMES if PROC_FS
145	select SRCU
146
147config INSTRUCTION_DECODER
148	def_bool y
149	depends on KPROBES || PERF_EVENTS || UPROBES
150
151config PERF_EVENTS_INTEL_UNCORE
152	def_bool y
153	depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
154
155config OUTPUT_FORMAT
156	string
157	default "elf32-i386" if X86_32
158	default "elf64-x86-64" if X86_64
159
160config ARCH_DEFCONFIG
161	string
162	default "arch/x86/configs/i386_defconfig" if X86_32
163	default "arch/x86/configs/x86_64_defconfig" if X86_64
164
165config LOCKDEP_SUPPORT
166	def_bool y
167
168config STACKTRACE_SUPPORT
169	def_bool y
170
171config HAVE_LATENCYTOP_SUPPORT
172	def_bool y
173
174config MMU
175	def_bool y
176
177config SBUS
178	bool
179
180config NEED_DMA_MAP_STATE
181	def_bool y
182	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
183
184config NEED_SG_DMA_LENGTH
185	def_bool y
186
187config GENERIC_ISA_DMA
188	def_bool y
189	depends on ISA_DMA_API
190
191config GENERIC_BUG
192	def_bool y
193	depends on BUG
194	select GENERIC_BUG_RELATIVE_POINTERS if X86_64
195
196config GENERIC_BUG_RELATIVE_POINTERS
197	bool
198
199config GENERIC_HWEIGHT
200	def_bool y
201
202config ARCH_MAY_HAVE_PC_FDC
203	def_bool y
204	depends on ISA_DMA_API
205
206config RWSEM_XCHGADD_ALGORITHM
207	def_bool y
208
209config GENERIC_CALIBRATE_DELAY
210	def_bool y
211
212config ARCH_HAS_CPU_RELAX
213	def_bool y
214
215config ARCH_HAS_CACHE_LINE_SIZE
216	def_bool y
217
218config HAVE_SETUP_PER_CPU_AREA
219	def_bool y
220
221config NEED_PER_CPU_EMBED_FIRST_CHUNK
222	def_bool y
223
224config NEED_PER_CPU_PAGE_FIRST_CHUNK
225	def_bool y
226
227config ARCH_HIBERNATION_POSSIBLE
228	def_bool y
229
230config ARCH_SUSPEND_POSSIBLE
231	def_bool y
232
233config ARCH_WANT_HUGE_PMD_SHARE
234	def_bool y
235
236config ARCH_WANT_GENERAL_HUGETLB
237	def_bool y
238
239config ZONE_DMA32
240	def_bool y if X86_64
241
242config AUDIT_ARCH
243	def_bool y if X86_64
244
245config ARCH_SUPPORTS_OPTIMIZED_INLINING
246	def_bool y
247
248config ARCH_SUPPORTS_DEBUG_PAGEALLOC
249	def_bool y
250
251config HAVE_INTEL_TXT
252	def_bool y
253	depends on INTEL_IOMMU && ACPI
254
255config X86_32_SMP
256	def_bool y
257	depends on X86_32 && SMP
258
259config X86_64_SMP
260	def_bool y
261	depends on X86_64 && SMP
262
263config X86_HT
264	def_bool y
265	depends on SMP
266
267config X86_32_LAZY_GS
268	def_bool y
269	depends on X86_32 && !CC_STACKPROTECTOR
270
271config ARCH_HWEIGHT_CFLAGS
272	string
273	default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
274	default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
275
276config ARCH_SUPPORTS_UPROBES
277	def_bool y
278
279config FIX_EARLYCON_MEM
280	def_bool y
281
282config PGTABLE_LEVELS
283	int
284	default 4 if X86_64
285	default 3 if X86_PAE
286	default 2
287
288source "init/Kconfig"
289source "kernel/Kconfig.freezer"
290
291menu "Processor type and features"
292
293config ZONE_DMA
294	bool "DMA memory allocation support" if EXPERT
295	default y
296	help
297	  DMA memory allocation support allows devices with less than 32-bit
298	  addressing to allocate within the first 16MB of address space.
299	  Disable if no such devices will be used.
300
301	  If unsure, say Y.
302
303config SMP
304	bool "Symmetric multi-processing support"
305	---help---
306	  This enables support for systems with more than one CPU. If you have
307	  a system with only one CPU, say N. If you have a system with more
308	  than one CPU, say Y.
309
310	  If you say N here, the kernel will run on uni- and multiprocessor
311	  machines, but will use only one CPU of a multiprocessor machine. If
312	  you say Y here, the kernel will run on many, but not all,
313	  uniprocessor machines. On a uniprocessor machine, the kernel
314	  will run faster if you say N here.
315
316	  Note that if you say Y here and choose architecture "586" or
317	  "Pentium" under "Processor family", the kernel will not work on 486
318	  architectures. Similarly, multiprocessor kernels for the "PPro"
319	  architecture may not work on all Pentium based boards.
320
321	  People using multiprocessor machines who say Y here should also say
322	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
323	  Management" code will be disabled if you say Y here.
324
325	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
326	  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
327	  <http://www.tldp.org/docs.html#howto>.
328
329	  If you don't know what to do here, say N.
330
331config X86_FEATURE_NAMES
332	bool "Processor feature human-readable names" if EMBEDDED
333	default y
334	---help---
335	  This option compiles in a table of x86 feature bits and corresponding
336	  names.  This is required to support /proc/cpuinfo and a few kernel
337	  messages.  You can disable this to save space, at the expense of
338	  making those few kernel messages show numeric feature bits instead.
339
340	  If in doubt, say Y.
341
342config X86_X2APIC
343	bool "Support x2apic"
344	depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
345	---help---
346	  This enables x2apic support on CPUs that have this feature.
347
348	  This allows 32-bit apic IDs (so it can support very large systems),
349	  and accesses the local apic via MSRs not via mmio.
350
351	  If you don't know what to do here, say N.
352
353config X86_MPPARSE
354	bool "Enable MPS table" if ACPI || SFI
355	default y
356	depends on X86_LOCAL_APIC
357	---help---
358	  For old smp systems that do not have proper acpi support. Newer systems
359	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
360
361config X86_BIGSMP
362	bool "Support for big SMP systems with more than 8 CPUs"
363	depends on X86_32 && SMP
364	---help---
365	  This option is needed for the systems that have more than 8 CPUs
366
367config GOLDFISH
368       def_bool y
369       depends on X86_GOLDFISH
370
371if X86_32
372config X86_EXTENDED_PLATFORM
373	bool "Support for extended (non-PC) x86 platforms"
374	default y
375	---help---
376	  If you disable this option then the kernel will only support
377	  standard PC platforms. (which covers the vast majority of
378	  systems out there.)
379
380	  If you enable this option then you'll be able to select support
381	  for the following (non-PC) 32 bit x86 platforms:
382		Goldfish (Android emulator)
383		AMD Elan
384		RDC R-321x SoC
385		SGI 320/540 (Visual Workstation)
386		STA2X11-based (e.g. Northville)
387		Moorestown MID devices
388
389	  If you have one of these systems, or if you want to build a
390	  generic distribution kernel, say Y here - otherwise say N.
391endif
392
393if X86_64
394config X86_EXTENDED_PLATFORM
395	bool "Support for extended (non-PC) x86 platforms"
396	default y
397	---help---
398	  If you disable this option then the kernel will only support
399	  standard PC platforms. (which covers the vast majority of
400	  systems out there.)
401
402	  If you enable this option then you'll be able to select support
403	  for the following (non-PC) 64 bit x86 platforms:
404		Numascale NumaChip
405		ScaleMP vSMP
406		SGI Ultraviolet
407
408	  If you have one of these systems, or if you want to build a
409	  generic distribution kernel, say Y here - otherwise say N.
410endif
411# This is an alphabetically sorted list of 64 bit extended platforms
412# Please maintain the alphabetic order if and when there are additions
413config X86_NUMACHIP
414	bool "Numascale NumaChip"
415	depends on X86_64
416	depends on X86_EXTENDED_PLATFORM
417	depends on NUMA
418	depends on SMP
419	depends on X86_X2APIC
420	depends on PCI_MMCONFIG
421	---help---
422	  Adds support for Numascale NumaChip large-SMP systems. Needed to
423	  enable more than ~168 cores.
424	  If you don't have one of these, you should say N here.
425
426config X86_VSMP
427	bool "ScaleMP vSMP"
428	select HYPERVISOR_GUEST
429	select PARAVIRT
430	depends on X86_64 && PCI
431	depends on X86_EXTENDED_PLATFORM
432	depends on SMP
433	---help---
434	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
435	  supposed to run on these EM64T-based machines.  Only choose this option
436	  if you have one of these machines.
437
438config X86_UV
439	bool "SGI Ultraviolet"
440	depends on X86_64
441	depends on X86_EXTENDED_PLATFORM
442	depends on NUMA
443	depends on X86_X2APIC
444	---help---
445	  This option is needed in order to support SGI Ultraviolet systems.
446	  If you don't have one of these, you should say N here.
447
448# Following is an alphabetically sorted list of 32 bit extended platforms
449# Please maintain the alphabetic order if and when there are additions
450
451config X86_GOLDFISH
452       bool "Goldfish (Virtual Platform)"
453       depends on X86_EXTENDED_PLATFORM
454       ---help---
455	 Enable support for the Goldfish virtual platform used primarily
456	 for Android development. Unless you are building for the Android
457	 Goldfish emulator say N here.
458
459config X86_INTEL_CE
460	bool "CE4100 TV platform"
461	depends on PCI
462	depends on PCI_GODIRECT
463	depends on X86_IO_APIC
464	depends on X86_32
465	depends on X86_EXTENDED_PLATFORM
466	select X86_REBOOTFIXUPS
467	select OF
468	select OF_EARLY_FLATTREE
469	select IRQ_DOMAIN
470	---help---
471	  Select for the Intel CE media processor (CE4100) SOC.
472	  This option compiles in support for the CE4100 SOC for settop
473	  boxes and media devices.
474
475config X86_INTEL_MID
476	bool "Intel MID platform support"
477	depends on X86_32
478	depends on X86_EXTENDED_PLATFORM
479	depends on X86_PLATFORM_DEVICES
480	depends on PCI
481	depends on PCI_GOANY
482	depends on X86_IO_APIC
483	select SFI
484	select I2C
485	select DW_APB_TIMER
486	select APB_TIMER
487	select INTEL_SCU_IPC
488	select MFD_INTEL_MSIC
489	---help---
490	  Select to build a kernel capable of supporting Intel MID (Mobile
491	  Internet Device) platform systems which do not have the PCI legacy
492	  interfaces. If you are building for a PC class system say N here.
493
494	  Intel MID platforms are based on an Intel processor and chipset which
495	  consume less power than most of the x86 derivatives.
496
497config X86_INTEL_QUARK
498	bool "Intel Quark platform support"
499	depends on X86_32
500	depends on X86_EXTENDED_PLATFORM
501	depends on X86_PLATFORM_DEVICES
502	depends on X86_TSC
503	depends on PCI
504	depends on PCI_GOANY
505	depends on X86_IO_APIC
506	select IOSF_MBI
507	select INTEL_IMR
508	select COMMON_CLK
509	---help---
510	  Select to include support for Quark X1000 SoC.
511	  Say Y here if you have a Quark based system such as the Arduino
512	  compatible Intel Galileo.
513
514config X86_INTEL_LPSS
515	bool "Intel Low Power Subsystem Support"
516	depends on ACPI
517	select COMMON_CLK
518	select PINCTRL
519	---help---
520	  Select to build support for Intel Low Power Subsystem such as
521	  found on Intel Lynxpoint PCH. Selecting this option enables
522	  things like clock tree (common clock framework) and pincontrol
523	  which are needed by the LPSS peripheral drivers.
524
525config X86_AMD_PLATFORM_DEVICE
526	bool "AMD ACPI2Platform devices support"
527	depends on ACPI
528	select COMMON_CLK
529	select PINCTRL
530	---help---
531	  Select to interpret AMD specific ACPI device to platform device
532	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
533	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
534	  implemented under PINCTRL subsystem.
535
536config IOSF_MBI
537	tristate "Intel SoC IOSF Sideband support for SoC platforms"
538	depends on PCI
539	---help---
540	  This option enables sideband register access support for Intel SoC
541	  platforms. On these platforms the IOSF sideband is used in lieu of
542	  MSR's for some register accesses, mostly but not limited to thermal
543	  and power. Drivers may query the availability of this device to
544	  determine if they need the sideband in order to work on these
545	  platforms. The sideband is available on the following SoC products.
546	  This list is not meant to be exclusive.
547	   - BayTrail
548	   - Braswell
549	   - Quark
550
551	  You should say Y if you are running a kernel on one of these SoC's.
552
553config IOSF_MBI_DEBUG
554	bool "Enable IOSF sideband access through debugfs"
555	depends on IOSF_MBI && DEBUG_FS
556	---help---
557	  Select this option to expose the IOSF sideband access registers (MCR,
558	  MDR, MCRX) through debugfs to write and read register information from
559	  different units on the SoC. This is most useful for obtaining device
560	  state information for debug and analysis. As this is a general access
561	  mechanism, users of this option would have specific knowledge of the
562	  device they want to access.
563
564	  If you don't require the option or are in doubt, say N.
565
566config X86_RDC321X
567	bool "RDC R-321x SoC"
568	depends on X86_32
569	depends on X86_EXTENDED_PLATFORM
570	select M486
571	select X86_REBOOTFIXUPS
572	---help---
573	  This option is needed for RDC R-321x system-on-chip, also known
574	  as R-8610-(G).
575	  If you don't have one of these chips, you should say N here.
576
577config X86_32_NON_STANDARD
578	bool "Support non-standard 32-bit SMP architectures"
579	depends on X86_32 && SMP
580	depends on X86_EXTENDED_PLATFORM
581	---help---
582	  This option compiles in the bigsmp and STA2X11 default
583	  subarchitectures.  It is intended for a generic binary
584	  kernel. If you select them all, kernel will probe it one by
585	  one and will fallback to default.
586
587# Alphabetically sorted list of Non standard 32 bit platforms
588
589config X86_SUPPORTS_MEMORY_FAILURE
590	def_bool y
591	# MCE code calls memory_failure():
592	depends on X86_MCE
593	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
594	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
595	depends on X86_64 || !SPARSEMEM
596	select ARCH_SUPPORTS_MEMORY_FAILURE
597
598config STA2X11
599	bool "STA2X11 Companion Chip Support"
600	depends on X86_32_NON_STANDARD && PCI
601	select X86_DEV_DMA_OPS
602	select X86_DMA_REMAP
603	select SWIOTLB
604	select MFD_STA2X11
605	select ARCH_REQUIRE_GPIOLIB
606	default n
607	---help---
608	  This adds support for boards based on the STA2X11 IO-Hub,
609	  a.k.a. "ConneXt". The chip is used in place of the standard
610	  PC chipset, so all "standard" peripherals are missing. If this
611	  option is selected the kernel will still be able to boot on
612	  standard PC machines.
613
614config X86_32_IRIS
615	tristate "Eurobraille/Iris poweroff module"
616	depends on X86_32
617	---help---
618	  The Iris machines from EuroBraille do not have APM or ACPI support
619	  to shut themselves down properly.  A special I/O sequence is
620	  needed to do so, which is what this module does at
621	  kernel shutdown.
622
623	  This is only for Iris machines from EuroBraille.
624
625	  If unused, say N.
626
627config SCHED_OMIT_FRAME_POINTER
628	def_bool y
629	prompt "Single-depth WCHAN output"
630	depends on X86
631	---help---
632	  Calculate simpler /proc/<PID>/wchan values. If this option
633	  is disabled then wchan values will recurse back to the
634	  caller function. This provides more accurate wchan values,
635	  at the expense of slightly more scheduling overhead.
636
637	  If in doubt, say "Y".
638
639menuconfig HYPERVISOR_GUEST
640	bool "Linux guest support"
641	---help---
642	  Say Y here to enable options for running Linux under various hyper-
643	  visors. This option enables basic hypervisor detection and platform
644	  setup.
645
646	  If you say N, all options in this submenu will be skipped and
647	  disabled, and Linux guest support won't be built in.
648
649if HYPERVISOR_GUEST
650
651config PARAVIRT
652	bool "Enable paravirtualization code"
653	---help---
654	  This changes the kernel so it can modify itself when it is run
655	  under a hypervisor, potentially improving performance significantly
656	  over full virtualization.  However, when run without a hypervisor
657	  the kernel is theoretically slower and slightly larger.
658
659config PARAVIRT_DEBUG
660	bool "paravirt-ops debugging"
661	depends on PARAVIRT && DEBUG_KERNEL
662	---help---
663	  Enable to debug paravirt_ops internals.  Specifically, BUG if
664	  a paravirt_op is missing when it is called.
665
666config PARAVIRT_SPINLOCKS
667	bool "Paravirtualization layer for spinlocks"
668	depends on PARAVIRT && SMP
669	select UNINLINE_SPIN_UNLOCK
670	---help---
671	  Paravirtualized spinlocks allow a pvops backend to replace the
672	  spinlock implementation with something virtualization-friendly
673	  (for example, block the virtual CPU rather than spinning).
674
675	  It has a minimal impact on native kernels and gives a nice performance
676	  benefit on paravirtualized KVM / Xen kernels.
677
678	  If you are unsure how to answer this question, answer Y.
679
680source "arch/x86/xen/Kconfig"
681
682config KVM_GUEST
683	bool "KVM Guest support (including kvmclock)"
684	depends on PARAVIRT
685	select PARAVIRT_CLOCK
686	default y
687	---help---
688	  This option enables various optimizations for running under the KVM
689	  hypervisor. It includes a paravirtualized clock, so that instead
690	  of relying on a PIT (or probably other) emulation by the
691	  underlying device model, the host provides the guest with
692	  timing infrastructure such as time of day, and system time
693
694config KVM_DEBUG_FS
695	bool "Enable debug information for KVM Guests in debugfs"
696	depends on KVM_GUEST && DEBUG_FS
697	default n
698	---help---
699	  This option enables collection of various statistics for KVM guest.
700	  Statistics are displayed in debugfs filesystem. Enabling this option
701	  may incur significant overhead.
702
703source "arch/x86/lguest/Kconfig"
704
705config PARAVIRT_TIME_ACCOUNTING
706	bool "Paravirtual steal time accounting"
707	depends on PARAVIRT
708	default n
709	---help---
710	  Select this option to enable fine granularity task steal time
711	  accounting. Time spent executing other tasks in parallel with
712	  the current vCPU is discounted from the vCPU power. To account for
713	  that, there can be a small performance impact.
714
715	  If in doubt, say N here.
716
717config PARAVIRT_CLOCK
718	bool
719
720endif #HYPERVISOR_GUEST
721
722config NO_BOOTMEM
723	def_bool y
724
725source "arch/x86/Kconfig.cpu"
726
727config HPET_TIMER
728	def_bool X86_64
729	prompt "HPET Timer Support" if X86_32
730	---help---
731	  Use the IA-PC HPET (High Precision Event Timer) to manage
732	  time in preference to the PIT and RTC, if a HPET is
733	  present.
734	  HPET is the next generation timer replacing legacy 8254s.
735	  The HPET provides a stable time base on SMP
736	  systems, unlike the TSC, but it is more expensive to access,
737	  as it is off-chip.  You can find the HPET spec at
738	  <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
739
740	  You can safely choose Y here.  However, HPET will only be
741	  activated if the platform and the BIOS support this feature.
742	  Otherwise the 8254 will be used for timing services.
743
744	  Choose N to continue using the legacy 8254 timer.
745
746config HPET_EMULATE_RTC
747	def_bool y
748	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
749
750config APB_TIMER
751       def_bool y if X86_INTEL_MID
752       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
753       select DW_APB_TIMER
754       depends on X86_INTEL_MID && SFI
755       help
756         APB timer is the replacement for 8254, HPET on X86 MID platforms.
757         The APBT provides a stable time base on SMP
758         systems, unlike the TSC, but it is more expensive to access,
759         as it is off-chip. APB timers are always running regardless of CPU
760         C states, they are used as per CPU clockevent device when possible.
761
762# Mark as expert because too many people got it wrong.
763# The code disables itself when not needed.
764config DMI
765	default y
766	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
767	bool "Enable DMI scanning" if EXPERT
768	---help---
769	  Enabled scanning of DMI to identify machine quirks. Say Y
770	  here unless you have verified that your setup is not
771	  affected by entries in the DMI blacklist. Required by PNP
772	  BIOS code.
773
774config GART_IOMMU
775	bool "Old AMD GART IOMMU support"
776	select SWIOTLB
777	depends on X86_64 && PCI && AMD_NB
778	---help---
779	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
780	  GART based hardware IOMMUs.
781
782	  The GART supports full DMA access for devices with 32-bit access
783	  limitations, on systems with more than 3 GB. This is usually needed
784	  for USB, sound, many IDE/SATA chipsets and some other devices.
785
786	  Newer systems typically have a modern AMD IOMMU, supported via
787	  the CONFIG_AMD_IOMMU=y config option.
788
789	  In normal configurations this driver is only active when needed:
790	  there's more than 3 GB of memory and the system contains a
791	  32-bit limited device.
792
793	  If unsure, say Y.
794
795config CALGARY_IOMMU
796	bool "IBM Calgary IOMMU support"
797	select SWIOTLB
798	depends on X86_64 && PCI
799	---help---
800	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
801	  systems. Needed to run systems with more than 3GB of memory
802	  properly with 32-bit PCI devices that do not support DAC
803	  (Double Address Cycle). Calgary also supports bus level
804	  isolation, where all DMAs pass through the IOMMU.  This
805	  prevents them from going anywhere except their intended
806	  destination. This catches hard-to-find kernel bugs and
807	  mis-behaving drivers and devices that do not use the DMA-API
808	  properly to set up their DMA buffers.  The IOMMU can be
809	  turned off at boot time with the iommu=off parameter.
810	  Normally the kernel will make the right choice by itself.
811	  If unsure, say Y.
812
813config CALGARY_IOMMU_ENABLED_BY_DEFAULT
814	def_bool y
815	prompt "Should Calgary be enabled by default?"
816	depends on CALGARY_IOMMU
817	---help---
818	  Should Calgary be enabled by default? if you choose 'y', Calgary
819	  will be used (if it exists). If you choose 'n', Calgary will not be
820	  used even if it exists. If you choose 'n' and would like to use
821	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
822	  If unsure, say Y.
823
824# need this always selected by IOMMU for the VIA workaround
825config SWIOTLB
826	def_bool y if X86_64
827	---help---
828	  Support for software bounce buffers used on x86-64 systems
829	  which don't have a hardware IOMMU. Using this PCI devices
830	  which can only access 32-bits of memory can be used on systems
831	  with more than 3 GB of memory.
832	  If unsure, say Y.
833
834config IOMMU_HELPER
835	def_bool y
836	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
837
838config MAXSMP
839	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
840	depends on X86_64 && SMP && DEBUG_KERNEL
841	select CPUMASK_OFFSTACK
842	---help---
843	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
844	  If unsure, say N.
845
846config NR_CPUS
847	int "Maximum number of CPUs" if SMP && !MAXSMP
848	range 2 8 if SMP && X86_32 && !X86_BIGSMP
849	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
850	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
851	default "1" if !SMP
852	default "8192" if MAXSMP
853	default "32" if SMP && X86_BIGSMP
854	default "8" if SMP
855	---help---
856	  This allows you to specify the maximum number of CPUs which this
857	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
858	  supported value is 4096, otherwise the maximum value is 512.  The
859	  minimum value which makes sense is 2.
860
861	  This is purely to save memory - each supported CPU adds
862	  approximately eight kilobytes to the kernel image.
863
864config SCHED_SMT
865	bool "SMT (Hyperthreading) scheduler support"
866	depends on X86_HT
867	---help---
868	  SMT scheduler support improves the CPU scheduler's decision making
869	  when dealing with Intel Pentium 4 chips with HyperThreading at a
870	  cost of slightly increased overhead in some places. If unsure say
871	  N here.
872
873config SCHED_MC
874	def_bool y
875	prompt "Multi-core scheduler support"
876	depends on X86_HT
877	---help---
878	  Multi-core scheduler support improves the CPU scheduler's decision
879	  making when dealing with multi-core CPU chips at a cost of slightly
880	  increased overhead in some places. If unsure say N here.
881
882source "kernel/Kconfig.preempt"
883
884config UP_LATE_INIT
885       def_bool y
886       depends on !SMP && X86_LOCAL_APIC
887
888config X86_UP_APIC
889	bool "Local APIC support on uniprocessors" if !PCI_MSI
890	default PCI_MSI
891	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
892	---help---
893	  A local APIC (Advanced Programmable Interrupt Controller) is an
894	  integrated interrupt controller in the CPU. If you have a single-CPU
895	  system which has a processor with a local APIC, you can say Y here to
896	  enable and use it. If you say Y here even though your machine doesn't
897	  have a local APIC, then the kernel will still run with no slowdown at
898	  all. The local APIC supports CPU-generated self-interrupts (timer,
899	  performance counters), and the NMI watchdog which detects hard
900	  lockups.
901
902config X86_UP_IOAPIC
903	bool "IO-APIC support on uniprocessors"
904	depends on X86_UP_APIC
905	---help---
906	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
907	  SMP-capable replacement for PC-style interrupt controllers. Most
908	  SMP systems and many recent uniprocessor systems have one.
909
910	  If you have a single-CPU system with an IO-APIC, you can say Y here
911	  to use it. If you say Y here even though your machine doesn't have
912	  an IO-APIC, then the kernel will still run with no slowdown at all.
913
914config X86_LOCAL_APIC
915	def_bool y
916	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
917	select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
918
919config X86_IO_APIC
920	def_bool y
921	depends on X86_LOCAL_APIC || X86_UP_IOAPIC
922	select IRQ_DOMAIN
923
924config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
925	bool "Reroute for broken boot IRQs"
926	depends on X86_IO_APIC
927	---help---
928	  This option enables a workaround that fixes a source of
929	  spurious interrupts. This is recommended when threaded
930	  interrupt handling is used on systems where the generation of
931	  superfluous "boot interrupts" cannot be disabled.
932
933	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
934	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
935	  kernel does during interrupt handling). On chipsets where this
936	  boot IRQ generation cannot be disabled, this workaround keeps
937	  the original IRQ line masked so that only the equivalent "boot
938	  IRQ" is delivered to the CPUs. The workaround also tells the
939	  kernel to set up the IRQ handler on the boot IRQ line. In this
940	  way only one interrupt is delivered to the kernel. Otherwise
941	  the spurious second interrupt may cause the kernel to bring
942	  down (vital) interrupt lines.
943
944	  Only affects "broken" chipsets. Interrupt sharing may be
945	  increased on these systems.
946
947config X86_MCE
948	bool "Machine Check / overheating reporting"
949	default y
950	---help---
951	  Machine Check support allows the processor to notify the
952	  kernel if it detects a problem (e.g. overheating, data corruption).
953	  The action the kernel takes depends on the severity of the problem,
954	  ranging from warning messages to halting the machine.
955
956config X86_MCE_INTEL
957	def_bool y
958	prompt "Intel MCE features"
959	depends on X86_MCE && X86_LOCAL_APIC
960	---help---
961	   Additional support for intel specific MCE features such as
962	   the thermal monitor.
963
964config X86_MCE_AMD
965	def_bool y
966	prompt "AMD MCE features"
967	depends on X86_MCE && X86_LOCAL_APIC
968	---help---
969	   Additional support for AMD specific MCE features such as
970	   the DRAM Error Threshold.
971
972config X86_ANCIENT_MCE
973	bool "Support for old Pentium 5 / WinChip machine checks"
974	depends on X86_32 && X86_MCE
975	---help---
976	  Include support for machine check handling on old Pentium 5 or WinChip
977	  systems. These typically need to be enabled explicitly on the command
978	  line.
979
980config X86_MCE_THRESHOLD
981	depends on X86_MCE_AMD || X86_MCE_INTEL
982	def_bool y
983
984config X86_MCE_INJECT
985	depends on X86_MCE
986	tristate "Machine check injector support"
987	---help---
988	  Provide support for injecting machine checks for testing purposes.
989	  If you don't know what a machine check is and you don't do kernel
990	  QA it is safe to say n.
991
992config X86_THERMAL_VECTOR
993	def_bool y
994	depends on X86_MCE_INTEL
995
996config VM86
997	bool "Enable VM86 support" if EXPERT
998	default y
999	depends on X86_32
1000	---help---
1001	  This option is required by programs like DOSEMU to run
1002	  16-bit real mode legacy code on x86 processors. It also may
1003	  be needed by software like XFree86 to initialize some video
1004	  cards via BIOS. Disabling this option saves about 6K.
1005
1006config X86_16BIT
1007	bool "Enable support for 16-bit segments" if EXPERT
1008	default y
1009	---help---
1010	  This option is required by programs like Wine to run 16-bit
1011	  protected mode legacy code on x86 processors.  Disabling
1012	  this option saves about 300 bytes on i386, or around 6K text
1013	  plus 16K runtime memory on x86-64,
1014
1015config X86_ESPFIX32
1016	def_bool y
1017	depends on X86_16BIT && X86_32
1018
1019config X86_ESPFIX64
1020	def_bool y
1021	depends on X86_16BIT && X86_64
1022
1023config X86_VSYSCALL_EMULATION
1024       bool "Enable vsyscall emulation" if EXPERT
1025       default y
1026       depends on X86_64
1027       ---help---
1028	 This enables emulation of the legacy vsyscall page.  Disabling
1029	 it is roughly equivalent to booting with vsyscall=none, except
1030	 that it will also disable the helpful warning if a program
1031	 tries to use a vsyscall.  With this option set to N, offending
1032	 programs will just segfault, citing addresses of the form
1033	 0xffffffffff600?00.
1034
1035	 This option is required by many programs built before 2013, and
1036	 care should be used even with newer programs if set to N.
1037
1038	 Disabling this option saves about 7K of kernel size and
1039	 possibly 4K of additional runtime pagetable memory.
1040
1041config TOSHIBA
1042	tristate "Toshiba Laptop support"
1043	depends on X86_32
1044	---help---
1045	  This adds a driver to safely access the System Management Mode of
1046	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1047	  not work on models with a Phoenix BIOS. The System Management Mode
1048	  is used to set the BIOS and power saving options on Toshiba portables.
1049
1050	  For information on utilities to make use of this driver see the
1051	  Toshiba Linux utilities web site at:
1052	  <http://www.buzzard.org.uk/toshiba/>.
1053
1054	  Say Y if you intend to run this kernel on a Toshiba portable.
1055	  Say N otherwise.
1056
1057config I8K
1058	tristate "Dell laptop support"
1059	select HWMON
1060	---help---
1061	  This adds a driver to safely access the System Management Mode
1062	  of the CPU on the Dell Inspiron 8000. The System Management Mode
1063	  is used to read cpu temperature and cooling fan status and to
1064	  control the fans on the I8K portables.
1065
1066	  This driver has been tested only on the Inspiron 8000 but it may
1067	  also work with other Dell laptops. You can force loading on other
1068	  models by passing the parameter `force=1' to the module. Use at
1069	  your own risk.
1070
1071	  For information on utilities to make use of this driver see the
1072	  I8K Linux utilities web site at:
1073	  <http://people.debian.org/~dz/i8k/>
1074
1075	  Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1076	  Say N otherwise.
1077
1078config X86_REBOOTFIXUPS
1079	bool "Enable X86 board specific fixups for reboot"
1080	depends on X86_32
1081	---help---
1082	  This enables chipset and/or board specific fixups to be done
1083	  in order to get reboot to work correctly. This is only needed on
1084	  some combinations of hardware and BIOS. The symptom, for which
1085	  this config is intended, is when reboot ends with a stalled/hung
1086	  system.
1087
1088	  Currently, the only fixup is for the Geode machines using
1089	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1090
1091	  Say Y if you want to enable the fixup. Currently, it's safe to
1092	  enable this option even if you don't need it.
1093	  Say N otherwise.
1094
1095config MICROCODE
1096	tristate "CPU microcode loading support"
1097	depends on CPU_SUP_AMD || CPU_SUP_INTEL
1098	select FW_LOADER
1099	---help---
1100
1101	  If you say Y here, you will be able to update the microcode on
1102	  certain Intel and AMD processors. The Intel support is for the
1103	  IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1104	  Xeon etc. The AMD support is for families 0x10 and later. You will
1105	  obviously need the actual microcode binary data itself which is not
1106	  shipped with the Linux kernel.
1107
1108	  This option selects the general module only, you need to select
1109	  at least one vendor specific module as well.
1110
1111	  To compile this driver as a module, choose M here: the module
1112	  will be called microcode.
1113
1114config MICROCODE_INTEL
1115	bool "Intel microcode loading support"
1116	depends on MICROCODE
1117	default MICROCODE
1118	select FW_LOADER
1119	---help---
1120	  This options enables microcode patch loading support for Intel
1121	  processors.
1122
1123	  For the current Intel microcode data package go to
1124	  <https://downloadcenter.intel.com> and search for
1125	  'Linux Processor Microcode Data File'.
1126
1127config MICROCODE_AMD
1128	bool "AMD microcode loading support"
1129	depends on MICROCODE
1130	select FW_LOADER
1131	---help---
1132	  If you select this option, microcode patch loading support for AMD
1133	  processors will be enabled.
1134
1135config MICROCODE_OLD_INTERFACE
1136	def_bool y
1137	depends on MICROCODE
1138
1139config MICROCODE_INTEL_EARLY
1140	bool
1141
1142config MICROCODE_AMD_EARLY
1143	bool
1144
1145config MICROCODE_EARLY
1146	bool "Early load microcode"
1147	depends on MICROCODE=y && BLK_DEV_INITRD
1148	select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1149	select MICROCODE_AMD_EARLY if MICROCODE_AMD
1150	default y
1151	help
1152	  This option provides functionality to read additional microcode data
1153	  at the beginning of initrd image. The data tells kernel to load
1154	  microcode to CPU's as early as possible. No functional change if no
1155	  microcode data is glued to the initrd, therefore it's safe to say Y.
1156
1157config X86_MSR
1158	tristate "/dev/cpu/*/msr - Model-specific register support"
1159	---help---
1160	  This device gives privileged processes access to the x86
1161	  Model-Specific Registers (MSRs).  It is a character device with
1162	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1163	  MSR accesses are directed to a specific CPU on multi-processor
1164	  systems.
1165
1166config X86_CPUID
1167	tristate "/dev/cpu/*/cpuid - CPU information support"
1168	---help---
1169	  This device gives processes access to the x86 CPUID instruction to
1170	  be executed on a specific processor.  It is a character device
1171	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1172	  /dev/cpu/31/cpuid.
1173
1174choice
1175	prompt "High Memory Support"
1176	default HIGHMEM4G
1177	depends on X86_32
1178
1179config NOHIGHMEM
1180	bool "off"
1181	---help---
1182	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1183	  However, the address space of 32-bit x86 processors is only 4
1184	  Gigabytes large. That means that, if you have a large amount of
1185	  physical memory, not all of it can be "permanently mapped" by the
1186	  kernel. The physical memory that's not permanently mapped is called
1187	  "high memory".
1188
1189	  If you are compiling a kernel which will never run on a machine with
1190	  more than 1 Gigabyte total physical RAM, answer "off" here (default
1191	  choice and suitable for most users). This will result in a "3GB/1GB"
1192	  split: 3GB are mapped so that each process sees a 3GB virtual memory
1193	  space and the remaining part of the 4GB virtual memory space is used
1194	  by the kernel to permanently map as much physical memory as
1195	  possible.
1196
1197	  If the machine has between 1 and 4 Gigabytes physical RAM, then
1198	  answer "4GB" here.
1199
1200	  If more than 4 Gigabytes is used then answer "64GB" here. This
1201	  selection turns Intel PAE (Physical Address Extension) mode on.
1202	  PAE implements 3-level paging on IA32 processors. PAE is fully
1203	  supported by Linux, PAE mode is implemented on all recent Intel
1204	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1205	  then the kernel will not boot on CPUs that don't support PAE!
1206
1207	  The actual amount of total physical memory will either be
1208	  auto detected or can be forced by using a kernel command line option
1209	  such as "mem=256M". (Try "man bootparam" or see the documentation of
1210	  your boot loader (lilo or loadlin) about how to pass options to the
1211	  kernel at boot time.)
1212
1213	  If unsure, say "off".
1214
1215config HIGHMEM4G
1216	bool "4GB"
1217	---help---
1218	  Select this if you have a 32-bit processor and between 1 and 4
1219	  gigabytes of physical RAM.
1220
1221config HIGHMEM64G
1222	bool "64GB"
1223	depends on !M486
1224	select X86_PAE
1225	---help---
1226	  Select this if you have a 32-bit processor and more than 4
1227	  gigabytes of physical RAM.
1228
1229endchoice
1230
1231choice
1232	prompt "Memory split" if EXPERT
1233	default VMSPLIT_3G
1234	depends on X86_32
1235	---help---
1236	  Select the desired split between kernel and user memory.
1237
1238	  If the address range available to the kernel is less than the
1239	  physical memory installed, the remaining memory will be available
1240	  as "high memory". Accessing high memory is a little more costly
1241	  than low memory, as it needs to be mapped into the kernel first.
1242	  Note that increasing the kernel address space limits the range
1243	  available to user programs, making the address space there
1244	  tighter.  Selecting anything other than the default 3G/1G split
1245	  will also likely make your kernel incompatible with binary-only
1246	  kernel modules.
1247
1248	  If you are not absolutely sure what you are doing, leave this
1249	  option alone!
1250
1251	config VMSPLIT_3G
1252		bool "3G/1G user/kernel split"
1253	config VMSPLIT_3G_OPT
1254		depends on !X86_PAE
1255		bool "3G/1G user/kernel split (for full 1G low memory)"
1256	config VMSPLIT_2G
1257		bool "2G/2G user/kernel split"
1258	config VMSPLIT_2G_OPT
1259		depends on !X86_PAE
1260		bool "2G/2G user/kernel split (for full 2G low memory)"
1261	config VMSPLIT_1G
1262		bool "1G/3G user/kernel split"
1263endchoice
1264
1265config PAGE_OFFSET
1266	hex
1267	default 0xB0000000 if VMSPLIT_3G_OPT
1268	default 0x80000000 if VMSPLIT_2G
1269	default 0x78000000 if VMSPLIT_2G_OPT
1270	default 0x40000000 if VMSPLIT_1G
1271	default 0xC0000000
1272	depends on X86_32
1273
1274config HIGHMEM
1275	def_bool y
1276	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1277
1278config X86_PAE
1279	bool "PAE (Physical Address Extension) Support"
1280	depends on X86_32 && !HIGHMEM4G
1281	---help---
1282	  PAE is required for NX support, and furthermore enables
1283	  larger swapspace support for non-overcommit purposes. It
1284	  has the cost of more pagetable lookup overhead, and also
1285	  consumes more pagetable space per process.
1286
1287config ARCH_PHYS_ADDR_T_64BIT
1288	def_bool y
1289	depends on X86_64 || X86_PAE
1290
1291config ARCH_DMA_ADDR_T_64BIT
1292	def_bool y
1293	depends on X86_64 || HIGHMEM64G
1294
1295config X86_DIRECT_GBPAGES
1296	def_bool y
1297	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1298	---help---
1299	  Certain kernel features effectively disable kernel
1300	  linear 1 GB mappings (even if the CPU otherwise
1301	  supports them), so don't confuse the user by printing
1302	  that we have them enabled.
1303
1304# Common NUMA Features
1305config NUMA
1306	bool "Numa Memory Allocation and Scheduler Support"
1307	depends on SMP
1308	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1309	default y if X86_BIGSMP
1310	---help---
1311	  Enable NUMA (Non Uniform Memory Access) support.
1312
1313	  The kernel will try to allocate memory used by a CPU on the
1314	  local memory controller of the CPU and add some more
1315	  NUMA awareness to the kernel.
1316
1317	  For 64-bit this is recommended if the system is Intel Core i7
1318	  (or later), AMD Opteron, or EM64T NUMA.
1319
1320	  For 32-bit this is only needed if you boot a 32-bit
1321	  kernel on a 64-bit NUMA platform.
1322
1323	  Otherwise, you should say N.
1324
1325config AMD_NUMA
1326	def_bool y
1327	prompt "Old style AMD Opteron NUMA detection"
1328	depends on X86_64 && NUMA && PCI
1329	---help---
1330	  Enable AMD NUMA node topology detection.  You should say Y here if
1331	  you have a multi processor AMD system. This uses an old method to
1332	  read the NUMA configuration directly from the builtin Northbridge
1333	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1334	  which also takes priority if both are compiled in.
1335
1336config X86_64_ACPI_NUMA
1337	def_bool y
1338	prompt "ACPI NUMA detection"
1339	depends on X86_64 && NUMA && ACPI && PCI
1340	select ACPI_NUMA
1341	---help---
1342	  Enable ACPI SRAT based node topology detection.
1343
1344# Some NUMA nodes have memory ranges that span
1345# other nodes.  Even though a pfn is valid and
1346# between a node's start and end pfns, it may not
1347# reside on that node.  See memmap_init_zone()
1348# for details.
1349config NODES_SPAN_OTHER_NODES
1350	def_bool y
1351	depends on X86_64_ACPI_NUMA
1352
1353config NUMA_EMU
1354	bool "NUMA emulation"
1355	depends on NUMA
1356	---help---
1357	  Enable NUMA emulation. A flat machine will be split
1358	  into virtual nodes when booted with "numa=fake=N", where N is the
1359	  number of nodes. This is only useful for debugging.
1360
1361config NODES_SHIFT
1362	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1363	range 1 10
1364	default "10" if MAXSMP
1365	default "6" if X86_64
1366	default "3"
1367	depends on NEED_MULTIPLE_NODES
1368	---help---
1369	  Specify the maximum number of NUMA Nodes available on the target
1370	  system.  Increases memory reserved to accommodate various tables.
1371
1372config ARCH_HAVE_MEMORY_PRESENT
1373	def_bool y
1374	depends on X86_32 && DISCONTIGMEM
1375
1376config NEED_NODE_MEMMAP_SIZE
1377	def_bool y
1378	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1379
1380config ARCH_FLATMEM_ENABLE
1381	def_bool y
1382	depends on X86_32 && !NUMA
1383
1384config ARCH_DISCONTIGMEM_ENABLE
1385	def_bool y
1386	depends on NUMA && X86_32
1387
1388config ARCH_DISCONTIGMEM_DEFAULT
1389	def_bool y
1390	depends on NUMA && X86_32
1391
1392config ARCH_SPARSEMEM_ENABLE
1393	def_bool y
1394	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1395	select SPARSEMEM_STATIC if X86_32
1396	select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1397
1398config ARCH_SPARSEMEM_DEFAULT
1399	def_bool y
1400	depends on X86_64
1401
1402config ARCH_SELECT_MEMORY_MODEL
1403	def_bool y
1404	depends on ARCH_SPARSEMEM_ENABLE
1405
1406config ARCH_MEMORY_PROBE
1407	bool "Enable sysfs memory/probe interface"
1408	depends on X86_64 && MEMORY_HOTPLUG
1409	help
1410	  This option enables a sysfs memory/probe interface for testing.
1411	  See Documentation/memory-hotplug.txt for more information.
1412	  If you are unsure how to answer this question, answer N.
1413
1414config ARCH_PROC_KCORE_TEXT
1415	def_bool y
1416	depends on X86_64 && PROC_KCORE
1417
1418config ILLEGAL_POINTER_VALUE
1419       hex
1420       default 0 if X86_32
1421       default 0xdead000000000000 if X86_64
1422
1423source "mm/Kconfig"
1424
1425config X86_PMEM_LEGACY
1426	bool "Support non-standard NVDIMMs and ADR protected memory"
1427	help
1428	  Treat memory marked using the non-standard e820 type of 12 as used
1429	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1430	  The kernel will offer these regions to the 'pmem' driver so
1431	  they can be used for persistent storage.
1432
1433	  Say Y if unsure.
1434
1435config HIGHPTE
1436	bool "Allocate 3rd-level pagetables from highmem"
1437	depends on HIGHMEM
1438	---help---
1439	  The VM uses one page table entry for each page of physical memory.
1440	  For systems with a lot of RAM, this can be wasteful of precious
1441	  low memory.  Setting this option will put user-space page table
1442	  entries in high memory.
1443
1444config X86_CHECK_BIOS_CORRUPTION
1445	bool "Check for low memory corruption"
1446	---help---
1447	  Periodically check for memory corruption in low memory, which
1448	  is suspected to be caused by BIOS.  Even when enabled in the
1449	  configuration, it is disabled at runtime.  Enable it by
1450	  setting "memory_corruption_check=1" on the kernel command
1451	  line.  By default it scans the low 64k of memory every 60
1452	  seconds; see the memory_corruption_check_size and
1453	  memory_corruption_check_period parameters in
1454	  Documentation/kernel-parameters.txt to adjust this.
1455
1456	  When enabled with the default parameters, this option has
1457	  almost no overhead, as it reserves a relatively small amount
1458	  of memory and scans it infrequently.  It both detects corruption
1459	  and prevents it from affecting the running system.
1460
1461	  It is, however, intended as a diagnostic tool; if repeatable
1462	  BIOS-originated corruption always affects the same memory,
1463	  you can use memmap= to prevent the kernel from using that
1464	  memory.
1465
1466config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1467	bool "Set the default setting of memory_corruption_check"
1468	depends on X86_CHECK_BIOS_CORRUPTION
1469	default y
1470	---help---
1471	  Set whether the default state of memory_corruption_check is
1472	  on or off.
1473
1474config X86_RESERVE_LOW
1475	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1476	default 64
1477	range 4 640
1478	---help---
1479	  Specify the amount of low memory to reserve for the BIOS.
1480
1481	  The first page contains BIOS data structures that the kernel
1482	  must not use, so that page must always be reserved.
1483
1484	  By default we reserve the first 64K of physical RAM, as a
1485	  number of BIOSes are known to corrupt that memory range
1486	  during events such as suspend/resume or monitor cable
1487	  insertion, so it must not be used by the kernel.
1488
1489	  You can set this to 4 if you are absolutely sure that you
1490	  trust the BIOS to get all its memory reservations and usages
1491	  right.  If you know your BIOS have problems beyond the
1492	  default 64K area, you can set this to 640 to avoid using the
1493	  entire low memory range.
1494
1495	  If you have doubts about the BIOS (e.g. suspend/resume does
1496	  not work or there's kernel crashes after certain hardware
1497	  hotplug events) then you might want to enable
1498	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1499	  typical corruption patterns.
1500
1501	  Leave this to the default value of 64 if you are unsure.
1502
1503config MATH_EMULATION
1504	bool
1505	prompt "Math emulation" if X86_32
1506	---help---
1507	  Linux can emulate a math coprocessor (used for floating point
1508	  operations) if you don't have one. 486DX and Pentium processors have
1509	  a math coprocessor built in, 486SX and 386 do not, unless you added
1510	  a 487DX or 387, respectively. (The messages during boot time can
1511	  give you some hints here ["man dmesg"].) Everyone needs either a
1512	  coprocessor or this emulation.
1513
1514	  If you don't have a math coprocessor, you need to say Y here; if you
1515	  say Y here even though you have a coprocessor, the coprocessor will
1516	  be used nevertheless. (This behavior can be changed with the kernel
1517	  command line option "no387", which comes handy if your coprocessor
1518	  is broken. Try "man bootparam" or see the documentation of your boot
1519	  loader (lilo or loadlin) about how to pass options to the kernel at
1520	  boot time.) This means that it is a good idea to say Y here if you
1521	  intend to use this kernel on different machines.
1522
1523	  More information about the internals of the Linux math coprocessor
1524	  emulation can be found in <file:arch/x86/math-emu/README>.
1525
1526	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
1527	  kernel, it won't hurt.
1528
1529config MTRR
1530	def_bool y
1531	prompt "MTRR (Memory Type Range Register) support" if EXPERT
1532	---help---
1533	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
1534	  the Memory Type Range Registers (MTRRs) may be used to control
1535	  processor access to memory ranges. This is most useful if you have
1536	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1537	  allows bus write transfers to be combined into a larger transfer
1538	  before bursting over the PCI/AGP bus. This can increase performance
1539	  of image write operations 2.5 times or more. Saying Y here creates a
1540	  /proc/mtrr file which may be used to manipulate your processor's
1541	  MTRRs. Typically the X server should use this.
1542
1543	  This code has a reasonably generic interface so that similar
1544	  control registers on other processors can be easily supported
1545	  as well:
1546
1547	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
1548	  Registers (ARRs) which provide a similar functionality to MTRRs. For
1549	  these, the ARRs are used to emulate the MTRRs.
1550	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1551	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1552	  write-combining. All of these processors are supported by this code
1553	  and it makes sense to say Y here if you have one of them.
1554
1555	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
1556	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
1557	  can lead to all sorts of problems, so it's good to say Y here.
1558
1559	  You can safely say Y even if your machine doesn't have MTRRs, you'll
1560	  just add about 9 KB to your kernel.
1561
1562	  See <file:Documentation/x86/mtrr.txt> for more information.
1563
1564config MTRR_SANITIZER
1565	def_bool y
1566	prompt "MTRR cleanup support"
1567	depends on MTRR
1568	---help---
1569	  Convert MTRR layout from continuous to discrete, so X drivers can
1570	  add writeback entries.
1571
1572	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
1573	  The largest mtrr entry size for a continuous block can be set with
1574	  mtrr_chunk_size.
1575
1576	  If unsure, say Y.
1577
1578config MTRR_SANITIZER_ENABLE_DEFAULT
1579	int "MTRR cleanup enable value (0-1)"
1580	range 0 1
1581	default "0"
1582	depends on MTRR_SANITIZER
1583	---help---
1584	  Enable mtrr cleanup default value
1585
1586config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1587	int "MTRR cleanup spare reg num (0-7)"
1588	range 0 7
1589	default "1"
1590	depends on MTRR_SANITIZER
1591	---help---
1592	  mtrr cleanup spare entries default, it can be changed via
1593	  mtrr_spare_reg_nr=N on the kernel command line.
1594
1595config X86_PAT
1596	def_bool y
1597	prompt "x86 PAT support" if EXPERT
1598	depends on MTRR
1599	---help---
1600	  Use PAT attributes to setup page level cache control.
1601
1602	  PATs are the modern equivalents of MTRRs and are much more
1603	  flexible than MTRRs.
1604
1605	  Say N here if you see bootup problems (boot crash, boot hang,
1606	  spontaneous reboots) or a non-working video driver.
1607
1608	  If unsure, say Y.
1609
1610config ARCH_USES_PG_UNCACHED
1611	def_bool y
1612	depends on X86_PAT
1613
1614config ARCH_RANDOM
1615	def_bool y
1616	prompt "x86 architectural random number generator" if EXPERT
1617	---help---
1618	  Enable the x86 architectural RDRAND instruction
1619	  (Intel Bull Mountain technology) to generate random numbers.
1620	  If supported, this is a high bandwidth, cryptographically
1621	  secure hardware random number generator.
1622
1623config X86_SMAP
1624	def_bool y
1625	prompt "Supervisor Mode Access Prevention" if EXPERT
1626	---help---
1627	  Supervisor Mode Access Prevention (SMAP) is a security
1628	  feature in newer Intel processors.  There is a small
1629	  performance cost if this enabled and turned on; there is
1630	  also a small increase in the kernel size if this is enabled.
1631
1632	  If unsure, say Y.
1633
1634config X86_INTEL_MPX
1635	prompt "Intel MPX (Memory Protection Extensions)"
1636	def_bool n
1637	depends on CPU_SUP_INTEL
1638	---help---
1639	  MPX provides hardware features that can be used in
1640	  conjunction with compiler-instrumented code to check
1641	  memory references.  It is designed to detect buffer
1642	  overflow or underflow bugs.
1643
1644	  This option enables running applications which are
1645	  instrumented or otherwise use MPX.  It does not use MPX
1646	  itself inside the kernel or to protect the kernel
1647	  against bad memory references.
1648
1649	  Enabling this option will make the kernel larger:
1650	  ~8k of kernel text and 36 bytes of data on a 64-bit
1651	  defconfig.  It adds a long to the 'mm_struct' which
1652	  will increase the kernel memory overhead of each
1653	  process and adds some branches to paths used during
1654	  exec() and munmap().
1655
1656	  For details, see Documentation/x86/intel_mpx.txt
1657
1658	  If unsure, say N.
1659
1660config EFI
1661	bool "EFI runtime service support"
1662	depends on ACPI
1663	select UCS2_STRING
1664	select EFI_RUNTIME_WRAPPERS
1665	---help---
1666	  This enables the kernel to use EFI runtime services that are
1667	  available (such as the EFI variable services).
1668
1669	  This option is only useful on systems that have EFI firmware.
1670	  In addition, you should use the latest ELILO loader available
1671	  at <http://elilo.sourceforge.net> in order to take advantage
1672	  of EFI runtime services. However, even with this option, the
1673	  resultant kernel should continue to boot on existing non-EFI
1674	  platforms.
1675
1676config EFI_STUB
1677       bool "EFI stub support"
1678       depends on EFI && !X86_USE_3DNOW
1679       select RELOCATABLE
1680       ---help---
1681          This kernel feature allows a bzImage to be loaded directly
1682	  by EFI firmware without the use of a bootloader.
1683
1684	  See Documentation/efi-stub.txt for more information.
1685
1686config EFI_MIXED
1687	bool "EFI mixed-mode support"
1688	depends on EFI_STUB && X86_64
1689	---help---
1690	   Enabling this feature allows a 64-bit kernel to be booted
1691	   on a 32-bit firmware, provided that your CPU supports 64-bit
1692	   mode.
1693
1694	   Note that it is not possible to boot a mixed-mode enabled
1695	   kernel via the EFI boot stub - a bootloader that supports
1696	   the EFI handover protocol must be used.
1697
1698	   If unsure, say N.
1699
1700config SECCOMP
1701	def_bool y
1702	prompt "Enable seccomp to safely compute untrusted bytecode"
1703	---help---
1704	  This kernel feature is useful for number crunching applications
1705	  that may need to compute untrusted bytecode during their
1706	  execution. By using pipes or other transports made available to
1707	  the process as file descriptors supporting the read/write
1708	  syscalls, it's possible to isolate those applications in
1709	  their own address space using seccomp. Once seccomp is
1710	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1711	  and the task is only allowed to execute a few safe syscalls
1712	  defined by each seccomp mode.
1713
1714	  If unsure, say Y. Only embedded should say N here.
1715
1716source kernel/Kconfig.hz
1717
1718config KEXEC
1719	bool "kexec system call"
1720	---help---
1721	  kexec is a system call that implements the ability to shutdown your
1722	  current kernel, and to start another kernel.  It is like a reboot
1723	  but it is independent of the system firmware.   And like a reboot
1724	  you can start any kernel with it, not just Linux.
1725
1726	  The name comes from the similarity to the exec system call.
1727
1728	  It is an ongoing process to be certain the hardware in a machine
1729	  is properly shutdown, so do not be surprised if this code does not
1730	  initially work for you.  As of this writing the exact hardware
1731	  interface is strongly in flux, so no good recommendation can be
1732	  made.
1733
1734config KEXEC_FILE
1735	bool "kexec file based system call"
1736	select BUILD_BIN2C
1737	depends on KEXEC
1738	depends on X86_64
1739	depends on CRYPTO=y
1740	depends on CRYPTO_SHA256=y
1741	---help---
1742	  This is new version of kexec system call. This system call is
1743	  file based and takes file descriptors as system call argument
1744	  for kernel and initramfs as opposed to list of segments as
1745	  accepted by previous system call.
1746
1747config KEXEC_VERIFY_SIG
1748	bool "Verify kernel signature during kexec_file_load() syscall"
1749	depends on KEXEC_FILE
1750	---help---
1751	  This option makes kernel signature verification mandatory for
1752	  the kexec_file_load() syscall.
1753
1754	  In addition to that option, you need to enable signature
1755	  verification for the corresponding kernel image type being
1756	  loaded in order for this to work.
1757
1758config KEXEC_BZIMAGE_VERIFY_SIG
1759	bool "Enable bzImage signature verification support"
1760	depends on KEXEC_VERIFY_SIG
1761	depends on SIGNED_PE_FILE_VERIFICATION
1762	select SYSTEM_TRUSTED_KEYRING
1763	---help---
1764	  Enable bzImage signature verification support.
1765
1766config CRASH_DUMP
1767	bool "kernel crash dumps"
1768	depends on X86_64 || (X86_32 && HIGHMEM)
1769	---help---
1770	  Generate crash dump after being started by kexec.
1771	  This should be normally only set in special crash dump kernels
1772	  which are loaded in the main kernel with kexec-tools into
1773	  a specially reserved region and then later executed after
1774	  a crash by kdump/kexec. The crash dump kernel must be compiled
1775	  to a memory address not used by the main kernel or BIOS using
1776	  PHYSICAL_START, or it must be built as a relocatable image
1777	  (CONFIG_RELOCATABLE=y).
1778	  For more details see Documentation/kdump/kdump.txt
1779
1780config KEXEC_JUMP
1781	bool "kexec jump"
1782	depends on KEXEC && HIBERNATION
1783	---help---
1784	  Jump between original kernel and kexeced kernel and invoke
1785	  code in physical address mode via KEXEC
1786
1787config PHYSICAL_START
1788	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1789	default "0x1000000"
1790	---help---
1791	  This gives the physical address where the kernel is loaded.
1792
1793	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1794	  bzImage will decompress itself to above physical address and
1795	  run from there. Otherwise, bzImage will run from the address where
1796	  it has been loaded by the boot loader and will ignore above physical
1797	  address.
1798
1799	  In normal kdump cases one does not have to set/change this option
1800	  as now bzImage can be compiled as a completely relocatable image
1801	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1802	  address. This option is mainly useful for the folks who don't want
1803	  to use a bzImage for capturing the crash dump and want to use a
1804	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
1805	  to be specifically compiled to run from a specific memory area
1806	  (normally a reserved region) and this option comes handy.
1807
1808	  So if you are using bzImage for capturing the crash dump,
1809	  leave the value here unchanged to 0x1000000 and set
1810	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1811	  for capturing the crash dump change this value to start of
1812	  the reserved region.  In other words, it can be set based on
1813	  the "X" value as specified in the "crashkernel=YM@XM"
1814	  command line boot parameter passed to the panic-ed
1815	  kernel. Please take a look at Documentation/kdump/kdump.txt
1816	  for more details about crash dumps.
1817
1818	  Usage of bzImage for capturing the crash dump is recommended as
1819	  one does not have to build two kernels. Same kernel can be used
1820	  as production kernel and capture kernel. Above option should have
1821	  gone away after relocatable bzImage support is introduced. But it
1822	  is present because there are users out there who continue to use
1823	  vmlinux for dump capture. This option should go away down the
1824	  line.
1825
1826	  Don't change this unless you know what you are doing.
1827
1828config RELOCATABLE
1829	bool "Build a relocatable kernel"
1830	default y
1831	---help---
1832	  This builds a kernel image that retains relocation information
1833	  so it can be loaded someplace besides the default 1MB.
1834	  The relocations tend to make the kernel binary about 10% larger,
1835	  but are discarded at runtime.
1836
1837	  One use is for the kexec on panic case where the recovery kernel
1838	  must live at a different physical address than the primary
1839	  kernel.
1840
1841	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1842	  it has been loaded at and the compile time physical address
1843	  (CONFIG_PHYSICAL_START) is used as the minimum location.
1844
1845config RANDOMIZE_BASE
1846	bool "Randomize the address of the kernel image"
1847	depends on RELOCATABLE
1848	default n
1849	---help---
1850	   Randomizes the physical and virtual address at which the
1851	   kernel image is decompressed, as a security feature that
1852	   deters exploit attempts relying on knowledge of the location
1853	   of kernel internals.
1854
1855	   Entropy is generated using the RDRAND instruction if it is
1856	   supported. If RDTSC is supported, it is used as well. If
1857	   neither RDRAND nor RDTSC are supported, then randomness is
1858	   read from the i8254 timer.
1859
1860	   The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1861	   and aligned according to PHYSICAL_ALIGN. Since the kernel is
1862	   built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1863	   minimum of 2MiB, only 10 bits of entropy is theoretically
1864	   possible. At best, due to page table layouts, 64-bit can use
1865	   9 bits of entropy and 32-bit uses 8 bits.
1866
1867	   If unsure, say N.
1868
1869config RANDOMIZE_BASE_MAX_OFFSET
1870	hex "Maximum kASLR offset allowed" if EXPERT
1871	depends on RANDOMIZE_BASE
1872	range 0x0 0x20000000 if X86_32
1873	default "0x20000000" if X86_32
1874	range 0x0 0x40000000 if X86_64
1875	default "0x40000000" if X86_64
1876	---help---
1877	  The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1878	  memory is used to determine the maximal offset in bytes that will
1879	  be applied to the kernel when kernel Address Space Layout
1880	  Randomization (kASLR) is active. This must be a multiple of
1881	  PHYSICAL_ALIGN.
1882
1883	  On 32-bit this is limited to 512MiB by page table layouts. The
1884	  default is 512MiB.
1885
1886	  On 64-bit this is limited by how the kernel fixmap page table is
1887	  positioned, so this cannot be larger than 1GiB currently. Without
1888	  RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1889	  and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1890	  modules area will shrink to compensate, up to the current maximum
1891	  1GiB to 1GiB split. The default is 1GiB.
1892
1893	  If unsure, leave at the default value.
1894
1895# Relocation on x86 needs some additional build support
1896config X86_NEED_RELOCS
1897	def_bool y
1898	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1899
1900config PHYSICAL_ALIGN
1901	hex "Alignment value to which kernel should be aligned"
1902	default "0x200000"
1903	range 0x2000 0x1000000 if X86_32
1904	range 0x200000 0x1000000 if X86_64
1905	---help---
1906	  This value puts the alignment restrictions on physical address
1907	  where kernel is loaded and run from. Kernel is compiled for an
1908	  address which meets above alignment restriction.
1909
1910	  If bootloader loads the kernel at a non-aligned address and
1911	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1912	  address aligned to above value and run from there.
1913
1914	  If bootloader loads the kernel at a non-aligned address and
1915	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1916	  load address and decompress itself to the address it has been
1917	  compiled for and run from there. The address for which kernel is
1918	  compiled already meets above alignment restrictions. Hence the
1919	  end result is that kernel runs from a physical address meeting
1920	  above alignment restrictions.
1921
1922	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
1923	  this value must be a multiple of 0x200000.
1924
1925	  Don't change this unless you know what you are doing.
1926
1927config HOTPLUG_CPU
1928	bool "Support for hot-pluggable CPUs"
1929	depends on SMP
1930	---help---
1931	  Say Y here to allow turning CPUs off and on. CPUs can be
1932	  controlled through /sys/devices/system/cpu.
1933	  ( Note: power management support will enable this option
1934	    automatically on SMP systems. )
1935	  Say N if you want to disable CPU hotplug.
1936
1937config BOOTPARAM_HOTPLUG_CPU0
1938	bool "Set default setting of cpu0_hotpluggable"
1939	default n
1940	depends on HOTPLUG_CPU
1941	---help---
1942	  Set whether default state of cpu0_hotpluggable is on or off.
1943
1944	  Say Y here to enable CPU0 hotplug by default. If this switch
1945	  is turned on, there is no need to give cpu0_hotplug kernel
1946	  parameter and the CPU0 hotplug feature is enabled by default.
1947
1948	  Please note: there are two known CPU0 dependencies if you want
1949	  to enable the CPU0 hotplug feature either by this switch or by
1950	  cpu0_hotplug kernel parameter.
1951
1952	  First, resume from hibernate or suspend always starts from CPU0.
1953	  So hibernate and suspend are prevented if CPU0 is offline.
1954
1955	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1956	  offline if any interrupt can not migrate out of CPU0. There may
1957	  be other CPU0 dependencies.
1958
1959	  Please make sure the dependencies are under your control before
1960	  you enable this feature.
1961
1962	  Say N if you don't want to enable CPU0 hotplug feature by default.
1963	  You still can enable the CPU0 hotplug feature at boot by kernel
1964	  parameter cpu0_hotplug.
1965
1966config DEBUG_HOTPLUG_CPU0
1967	def_bool n
1968	prompt "Debug CPU0 hotplug"
1969	depends on HOTPLUG_CPU
1970	---help---
1971	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1972	  soon as possible and boots up userspace with CPU0 offlined. User
1973	  can online CPU0 back after boot time.
1974
1975	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
1976	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1977	  compilation or giving cpu0_hotplug kernel parameter at boot.
1978
1979	  If unsure, say N.
1980
1981config COMPAT_VDSO
1982	def_bool n
1983	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1984	depends on X86_32 || IA32_EMULATION
1985	---help---
1986	  Certain buggy versions of glibc will crash if they are
1987	  presented with a 32-bit vDSO that is not mapped at the address
1988	  indicated in its segment table.
1989
1990	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1991	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1992	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
1993	  the only released version with the bug, but OpenSUSE 9
1994	  contains a buggy "glibc 2.3.2".
1995
1996	  The symptom of the bug is that everything crashes on startup, saying:
1997	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1998
1999	  Saying Y here changes the default value of the vdso32 boot
2000	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
2001	  This works around the glibc bug but hurts performance.
2002
2003	  If unsure, say N: if you are compiling your own kernel, you
2004	  are unlikely to be using a buggy version of glibc.
2005
2006config CMDLINE_BOOL
2007	bool "Built-in kernel command line"
2008	---help---
2009	  Allow for specifying boot arguments to the kernel at
2010	  build time.  On some systems (e.g. embedded ones), it is
2011	  necessary or convenient to provide some or all of the
2012	  kernel boot arguments with the kernel itself (that is,
2013	  to not rely on the boot loader to provide them.)
2014
2015	  To compile command line arguments into the kernel,
2016	  set this option to 'Y', then fill in the
2017	  the boot arguments in CONFIG_CMDLINE.
2018
2019	  Systems with fully functional boot loaders (i.e. non-embedded)
2020	  should leave this option set to 'N'.
2021
2022config CMDLINE
2023	string "Built-in kernel command string"
2024	depends on CMDLINE_BOOL
2025	default ""
2026	---help---
2027	  Enter arguments here that should be compiled into the kernel
2028	  image and used at boot time.  If the boot loader provides a
2029	  command line at boot time, it is appended to this string to
2030	  form the full kernel command line, when the system boots.
2031
2032	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2033	  change this behavior.
2034
2035	  In most cases, the command line (whether built-in or provided
2036	  by the boot loader) should specify the device for the root
2037	  file system.
2038
2039config CMDLINE_OVERRIDE
2040	bool "Built-in command line overrides boot loader arguments"
2041	depends on CMDLINE_BOOL
2042	---help---
2043	  Set this option to 'Y' to have the kernel ignore the boot loader
2044	  command line, and use ONLY the built-in command line.
2045
2046	  This is used to work around broken boot loaders.  This should
2047	  be set to 'N' under normal conditions.
2048
2049source "kernel/livepatch/Kconfig"
2050
2051endmenu
2052
2053config ARCH_ENABLE_MEMORY_HOTPLUG
2054	def_bool y
2055	depends on X86_64 || (X86_32 && HIGHMEM)
2056
2057config ARCH_ENABLE_MEMORY_HOTREMOVE
2058	def_bool y
2059	depends on MEMORY_HOTPLUG
2060
2061config USE_PERCPU_NUMA_NODE_ID
2062	def_bool y
2063	depends on NUMA
2064
2065config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2066	def_bool y
2067	depends on X86_64 || X86_PAE
2068
2069config ARCH_ENABLE_HUGEPAGE_MIGRATION
2070	def_bool y
2071	depends on X86_64 && HUGETLB_PAGE && MIGRATION
2072
2073menu "Power management and ACPI options"
2074
2075config ARCH_HIBERNATION_HEADER
2076	def_bool y
2077	depends on X86_64 && HIBERNATION
2078
2079source "kernel/power/Kconfig"
2080
2081source "drivers/acpi/Kconfig"
2082
2083source "drivers/sfi/Kconfig"
2084
2085config X86_APM_BOOT
2086	def_bool y
2087	depends on APM
2088
2089menuconfig APM
2090	tristate "APM (Advanced Power Management) BIOS support"
2091	depends on X86_32 && PM_SLEEP
2092	---help---
2093	  APM is a BIOS specification for saving power using several different
2094	  techniques. This is mostly useful for battery powered laptops with
2095	  APM compliant BIOSes. If you say Y here, the system time will be
2096	  reset after a RESUME operation, the /proc/apm device will provide
2097	  battery status information, and user-space programs will receive
2098	  notification of APM "events" (e.g. battery status change).
2099
2100	  If you select "Y" here, you can disable actual use of the APM
2101	  BIOS by passing the "apm=off" option to the kernel at boot time.
2102
2103	  Note that the APM support is almost completely disabled for
2104	  machines with more than one CPU.
2105
2106	  In order to use APM, you will need supporting software. For location
2107	  and more information, read <file:Documentation/power/apm-acpi.txt>
2108	  and the Battery Powered Linux mini-HOWTO, available from
2109	  <http://www.tldp.org/docs.html#howto>.
2110
2111	  This driver does not spin down disk drives (see the hdparm(8)
2112	  manpage ("man 8 hdparm") for that), and it doesn't turn off
2113	  VESA-compliant "green" monitors.
2114
2115	  This driver does not support the TI 4000M TravelMate and the ACER
2116	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
2117	  desktop machines also don't have compliant BIOSes, and this driver
2118	  may cause those machines to panic during the boot phase.
2119
2120	  Generally, if you don't have a battery in your machine, there isn't
2121	  much point in using this driver and you should say N. If you get
2122	  random kernel OOPSes or reboots that don't seem to be related to
2123	  anything, try disabling/enabling this option (or disabling/enabling
2124	  APM in your BIOS).
2125
2126	  Some other things you should try when experiencing seemingly random,
2127	  "weird" problems:
2128
2129	  1) make sure that you have enough swap space and that it is
2130	  enabled.
2131	  2) pass the "no-hlt" option to the kernel
2132	  3) switch on floating point emulation in the kernel and pass
2133	  the "no387" option to the kernel
2134	  4) pass the "floppy=nodma" option to the kernel
2135	  5) pass the "mem=4M" option to the kernel (thereby disabling
2136	  all but the first 4 MB of RAM)
2137	  6) make sure that the CPU is not over clocked.
2138	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2139	  8) disable the cache from your BIOS settings
2140	  9) install a fan for the video card or exchange video RAM
2141	  10) install a better fan for the CPU
2142	  11) exchange RAM chips
2143	  12) exchange the motherboard.
2144
2145	  To compile this driver as a module, choose M here: the
2146	  module will be called apm.
2147
2148if APM
2149
2150config APM_IGNORE_USER_SUSPEND
2151	bool "Ignore USER SUSPEND"
2152	---help---
2153	  This option will ignore USER SUSPEND requests. On machines with a
2154	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
2155	  series notebooks, it is necessary to say Y because of a BIOS bug.
2156
2157config APM_DO_ENABLE
2158	bool "Enable PM at boot time"
2159	---help---
2160	  Enable APM features at boot time. From page 36 of the APM BIOS
2161	  specification: "When disabled, the APM BIOS does not automatically
2162	  power manage devices, enter the Standby State, enter the Suspend
2163	  State, or take power saving steps in response to CPU Idle calls."
2164	  This driver will make CPU Idle calls when Linux is idle (unless this
2165	  feature is turned off -- see "Do CPU IDLE calls", below). This
2166	  should always save battery power, but more complicated APM features
2167	  will be dependent on your BIOS implementation. You may need to turn
2168	  this option off if your computer hangs at boot time when using APM
2169	  support, or if it beeps continuously instead of suspending. Turn
2170	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2171	  T400CDT. This is off by default since most machines do fine without
2172	  this feature.
2173
2174config APM_CPU_IDLE
2175	depends on CPU_IDLE
2176	bool "Make CPU Idle calls when idle"
2177	---help---
2178	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2179	  On some machines, this can activate improved power savings, such as
2180	  a slowed CPU clock rate, when the machine is idle. These idle calls
2181	  are made after the idle loop has run for some length of time (e.g.,
2182	  333 mS). On some machines, this will cause a hang at boot time or
2183	  whenever the CPU becomes idle. (On machines with more than one CPU,
2184	  this option does nothing.)
2185
2186config APM_DISPLAY_BLANK
2187	bool "Enable console blanking using APM"
2188	---help---
2189	  Enable console blanking using the APM. Some laptops can use this to
2190	  turn off the LCD backlight when the screen blanker of the Linux
2191	  virtual console blanks the screen. Note that this is only used by
2192	  the virtual console screen blanker, and won't turn off the backlight
2193	  when using the X Window system. This also doesn't have anything to
2194	  do with your VESA-compliant power-saving monitor. Further, this
2195	  option doesn't work for all laptops -- it might not turn off your
2196	  backlight at all, or it might print a lot of errors to the console,
2197	  especially if you are using gpm.
2198
2199config APM_ALLOW_INTS
2200	bool "Allow interrupts during APM BIOS calls"
2201	---help---
2202	  Normally we disable external interrupts while we are making calls to
2203	  the APM BIOS as a measure to lessen the effects of a badly behaving
2204	  BIOS implementation.  The BIOS should reenable interrupts if it
2205	  needs to.  Unfortunately, some BIOSes do not -- especially those in
2206	  many of the newer IBM Thinkpads.  If you experience hangs when you
2207	  suspend, try setting this to Y.  Otherwise, say N.
2208
2209endif # APM
2210
2211source "drivers/cpufreq/Kconfig"
2212
2213source "drivers/cpuidle/Kconfig"
2214
2215source "drivers/idle/Kconfig"
2216
2217endmenu
2218
2219
2220menu "Bus options (PCI etc.)"
2221
2222config PCI
2223	bool "PCI support"
2224	default y
2225	---help---
2226	  Find out whether you have a PCI motherboard. PCI is the name of a
2227	  bus system, i.e. the way the CPU talks to the other stuff inside
2228	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2229	  VESA. If you have PCI, say Y, otherwise N.
2230
2231choice
2232	prompt "PCI access mode"
2233	depends on X86_32 && PCI
2234	default PCI_GOANY
2235	---help---
2236	  On PCI systems, the BIOS can be used to detect the PCI devices and
2237	  determine their configuration. However, some old PCI motherboards
2238	  have BIOS bugs and may crash if this is done. Also, some embedded
2239	  PCI-based systems don't have any BIOS at all. Linux can also try to
2240	  detect the PCI hardware directly without using the BIOS.
2241
2242	  With this option, you can specify how Linux should detect the
2243	  PCI devices. If you choose "BIOS", the BIOS will be used,
2244	  if you choose "Direct", the BIOS won't be used, and if you
2245	  choose "MMConfig", then PCI Express MMCONFIG will be used.
2246	  If you choose "Any", the kernel will try MMCONFIG, then the
2247	  direct access method and falls back to the BIOS if that doesn't
2248	  work. If unsure, go with the default, which is "Any".
2249
2250config PCI_GOBIOS
2251	bool "BIOS"
2252
2253config PCI_GOMMCONFIG
2254	bool "MMConfig"
2255
2256config PCI_GODIRECT
2257	bool "Direct"
2258
2259config PCI_GOOLPC
2260	bool "OLPC XO-1"
2261	depends on OLPC
2262
2263config PCI_GOANY
2264	bool "Any"
2265
2266endchoice
2267
2268config PCI_BIOS
2269	def_bool y
2270	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2271
2272# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2273config PCI_DIRECT
2274	def_bool y
2275	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2276
2277config PCI_MMCONFIG
2278	def_bool y
2279	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2280
2281config PCI_OLPC
2282	def_bool y
2283	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2284
2285config PCI_XEN
2286	def_bool y
2287	depends on PCI && XEN
2288	select SWIOTLB_XEN
2289
2290config PCI_DOMAINS
2291	def_bool y
2292	depends on PCI
2293
2294config PCI_MMCONFIG
2295	bool "Support mmconfig PCI config space access"
2296	depends on X86_64 && PCI && ACPI
2297
2298config PCI_CNB20LE_QUIRK
2299	bool "Read CNB20LE Host Bridge Windows" if EXPERT
2300	depends on PCI
2301	help
2302	  Read the PCI windows out of the CNB20LE host bridge. This allows
2303	  PCI hotplug to work on systems with the CNB20LE chipset which do
2304	  not have ACPI.
2305
2306	  There's no public spec for this chipset, and this functionality
2307	  is known to be incomplete.
2308
2309	  You should say N unless you know you need this.
2310
2311source "drivers/pci/pcie/Kconfig"
2312
2313source "drivers/pci/Kconfig"
2314
2315# x86_64 have no ISA slots, but can have ISA-style DMA.
2316config ISA_DMA_API
2317	bool "ISA-style DMA support" if (X86_64 && EXPERT)
2318	default y
2319	help
2320	  Enables ISA-style DMA support for devices requiring such controllers.
2321	  If unsure, say Y.
2322
2323if X86_32
2324
2325config ISA
2326	bool "ISA support"
2327	---help---
2328	  Find out whether you have ISA slots on your motherboard.  ISA is the
2329	  name of a bus system, i.e. the way the CPU talks to the other stuff
2330	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
2331	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2332	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
2333
2334config EISA
2335	bool "EISA support"
2336	depends on ISA
2337	---help---
2338	  The Extended Industry Standard Architecture (EISA) bus was
2339	  developed as an open alternative to the IBM MicroChannel bus.
2340
2341	  The EISA bus provided some of the features of the IBM MicroChannel
2342	  bus while maintaining backward compatibility with cards made for
2343	  the older ISA bus.  The EISA bus saw limited use between 1988 and
2344	  1995 when it was made obsolete by the PCI bus.
2345
2346	  Say Y here if you are building a kernel for an EISA-based machine.
2347
2348	  Otherwise, say N.
2349
2350source "drivers/eisa/Kconfig"
2351
2352config SCx200
2353	tristate "NatSemi SCx200 support"
2354	---help---
2355	  This provides basic support for National Semiconductor's
2356	  (now AMD's) Geode processors.  The driver probes for the
2357	  PCI-IDs of several on-chip devices, so its a good dependency
2358	  for other scx200_* drivers.
2359
2360	  If compiled as a module, the driver is named scx200.
2361
2362config SCx200HR_TIMER
2363	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2364	depends on SCx200
2365	default y
2366	---help---
2367	  This driver provides a clocksource built upon the on-chip
2368	  27MHz high-resolution timer.  Its also a workaround for
2369	  NSC Geode SC-1100's buggy TSC, which loses time when the
2370	  processor goes idle (as is done by the scheduler).  The
2371	  other workaround is idle=poll boot option.
2372
2373config OLPC
2374	bool "One Laptop Per Child support"
2375	depends on !X86_PAE
2376	select GPIOLIB
2377	select OF
2378	select OF_PROMTREE
2379	select IRQ_DOMAIN
2380	---help---
2381	  Add support for detecting the unique features of the OLPC
2382	  XO hardware.
2383
2384config OLPC_XO1_PM
2385	bool "OLPC XO-1 Power Management"
2386	depends on OLPC && MFD_CS5535 && PM_SLEEP
2387	select MFD_CORE
2388	---help---
2389	  Add support for poweroff and suspend of the OLPC XO-1 laptop.
2390
2391config OLPC_XO1_RTC
2392	bool "OLPC XO-1 Real Time Clock"
2393	depends on OLPC_XO1_PM && RTC_DRV_CMOS
2394	---help---
2395	  Add support for the XO-1 real time clock, which can be used as a
2396	  programmable wakeup source.
2397
2398config OLPC_XO1_SCI
2399	bool "OLPC XO-1 SCI extras"
2400	depends on OLPC && OLPC_XO1_PM
2401	depends on INPUT=y
2402	select POWER_SUPPLY
2403	select GPIO_CS5535
2404	select MFD_CORE
2405	---help---
2406	  Add support for SCI-based features of the OLPC XO-1 laptop:
2407	   - EC-driven system wakeups
2408	   - Power button
2409	   - Ebook switch
2410	   - Lid switch
2411	   - AC adapter status updates
2412	   - Battery status updates
2413
2414config OLPC_XO15_SCI
2415	bool "OLPC XO-1.5 SCI extras"
2416	depends on OLPC && ACPI
2417	select POWER_SUPPLY
2418	---help---
2419	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
2420	   - EC-driven system wakeups
2421	   - AC adapter status updates
2422	   - Battery status updates
2423
2424config ALIX
2425	bool "PCEngines ALIX System Support (LED setup)"
2426	select GPIOLIB
2427	---help---
2428	  This option enables system support for the PCEngines ALIX.
2429	  At present this just sets up LEDs for GPIO control on
2430	  ALIX2/3/6 boards.  However, other system specific setup should
2431	  get added here.
2432
2433	  Note: You must still enable the drivers for GPIO and LED support
2434	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2435
2436	  Note: You have to set alix.force=1 for boards with Award BIOS.
2437
2438config NET5501
2439	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2440	select GPIOLIB
2441	---help---
2442	  This option enables system support for the Soekris Engineering net5501.
2443
2444config GEOS
2445	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2446	select GPIOLIB
2447	depends on DMI
2448	---help---
2449	  This option enables system support for the Traverse Technologies GEOS.
2450
2451config TS5500
2452	bool "Technologic Systems TS-5500 platform support"
2453	depends on MELAN
2454	select CHECK_SIGNATURE
2455	select NEW_LEDS
2456	select LEDS_CLASS
2457	---help---
2458	  This option enables system support for the Technologic Systems TS-5500.
2459
2460endif # X86_32
2461
2462config AMD_NB
2463	def_bool y
2464	depends on CPU_SUP_AMD && PCI
2465
2466source "drivers/pcmcia/Kconfig"
2467
2468source "drivers/pci/hotplug/Kconfig"
2469
2470config RAPIDIO
2471	tristate "RapidIO support"
2472	depends on PCI
2473	default n
2474	help
2475	  If enabled this option will include drivers and the core
2476	  infrastructure code to support RapidIO interconnect devices.
2477
2478source "drivers/rapidio/Kconfig"
2479
2480config X86_SYSFB
2481	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2482	help
2483	  Firmwares often provide initial graphics framebuffers so the BIOS,
2484	  bootloader or kernel can show basic video-output during boot for
2485	  user-guidance and debugging. Historically, x86 used the VESA BIOS
2486	  Extensions and EFI-framebuffers for this, which are mostly limited
2487	  to x86.
2488	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2489	  framebuffers so the new generic system-framebuffer drivers can be
2490	  used on x86. If the framebuffer is not compatible with the generic
2491	  modes, it is adverticed as fallback platform framebuffer so legacy
2492	  drivers like efifb, vesafb and uvesafb can pick it up.
2493	  If this option is not selected, all system framebuffers are always
2494	  marked as fallback platform framebuffers as usual.
2495
2496	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2497	  not be able to pick up generic system framebuffers if this option
2498	  is selected. You are highly encouraged to enable simplefb as
2499	  replacement if you select this option. simplefb can correctly deal
2500	  with generic system framebuffers. But you should still keep vesafb
2501	  and others enabled as fallback if a system framebuffer is
2502	  incompatible with simplefb.
2503
2504	  If unsure, say Y.
2505
2506endmenu
2507
2508
2509menu "Executable file formats / Emulations"
2510
2511source "fs/Kconfig.binfmt"
2512
2513config IA32_EMULATION
2514	bool "IA32 Emulation"
2515	depends on X86_64
2516	select BINFMT_ELF
2517	select COMPAT_BINFMT_ELF
2518	select HAVE_UID16
2519	---help---
2520	  Include code to run legacy 32-bit programs under a
2521	  64-bit kernel. You should likely turn this on, unless you're
2522	  100% sure that you don't have any 32-bit programs left.
2523
2524config IA32_AOUT
2525	tristate "IA32 a.out support"
2526	depends on IA32_EMULATION
2527	---help---
2528	  Support old a.out binaries in the 32bit emulation.
2529
2530config X86_X32
2531	bool "x32 ABI for 64-bit mode"
2532	depends on X86_64 && IA32_EMULATION
2533	---help---
2534	  Include code to run binaries for the x32 native 32-bit ABI
2535	  for 64-bit processors.  An x32 process gets access to the
2536	  full 64-bit register file and wide data path while leaving
2537	  pointers at 32 bits for smaller memory footprint.
2538
2539	  You will need a recent binutils (2.22 or later) with
2540	  elf32_x86_64 support enabled to compile a kernel with this
2541	  option set.
2542
2543config COMPAT
2544	def_bool y
2545	depends on IA32_EMULATION || X86_X32
2546	select ARCH_WANT_OLD_COMPAT_IPC
2547
2548if COMPAT
2549config COMPAT_FOR_U64_ALIGNMENT
2550	def_bool y
2551
2552config SYSVIPC_COMPAT
2553	def_bool y
2554	depends on SYSVIPC
2555
2556config KEYS_COMPAT
2557	def_bool y
2558	depends on KEYS
2559endif
2560
2561endmenu
2562
2563
2564config HAVE_ATOMIC_IOMAP
2565	def_bool y
2566	depends on X86_32
2567
2568config X86_DEV_DMA_OPS
2569	bool
2570	depends on X86_64 || STA2X11
2571
2572config X86_DMA_REMAP
2573	bool
2574	depends on STA2X11
2575
2576config PMC_ATOM
2577	def_bool y
2578        depends on PCI
2579
2580source "net/Kconfig"
2581
2582source "drivers/Kconfig"
2583
2584source "drivers/firmware/Kconfig"
2585
2586source "fs/Kconfig"
2587
2588source "arch/x86/Kconfig.debug"
2589
2590source "security/Kconfig"
2591
2592source "crypto/Kconfig"
2593
2594source "arch/x86/kvm/Kconfig"
2595
2596source "lib/Kconfig"
2597