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Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01001# Select 32 or 64 bit
2config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01003 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00004 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01005 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01006 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
Jan Beulich3120e252012-09-10 12:41:45 +010010 def_bool y
11 depends on !64BIT
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010012
13config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010014 def_bool y
15 depends on 64BIT
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010016
17### Arch settings
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010018config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010019 def_bool y
Ingo Molnar6471b822015-06-03 10:00:13 +020020 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Stephen Boyd446f24d2013-04-30 15:28:42 -070026 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Dan Williams21266be2015-11-19 18:19:29 -080027 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020028 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070029 select ARCH_HAS_FAST_MULTIPLIER
Riku Voipio957e3fa2014-12-12 16:57:44 -080030 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070031 select ARCH_HAS_KCOV if X86_64
Dan Williams96601ad2015-08-24 18:29:38 -040032 select ARCH_HAS_PMEM_API if X86_64
Ross Zwisler67a3e8f2015-08-27 13:14:20 -060033 select ARCH_HAS_MMIO_FLUSH
Ingo Molnar6471b822015-06-03 10:00:13 +020034 select ARCH_HAS_SG_CHAIN
Andrey Ryabininc6d30852016-01-20 15:00:55 -080035 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020036 select ARCH_HAVE_NMI_SAFE_CMPXCHG
37 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040038 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080039 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020040 select ARCH_SUPPORTS_ATOMIC_RMW
Mel Gorman3b242c62015-06-30 14:57:13 -070041 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
Ingo Molnar6471b822015-06-03 10:00:13 +020042 select ARCH_SUPPORTS_INT128 if X86_64
43 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
44 select ARCH_USE_BUILTIN_BSWAP
45 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
46 select ARCH_USE_QUEUED_RWLOCKS
47 select ARCH_USE_QUEUED_SPINLOCKS
Mel Gorman72b252a2015-09-04 15:47:32 -070048 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +020049 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Ingo Molnarda4276b2009-01-07 11:05:10 +010050 select ARCH_WANT_FRAME_POINTERS
Ingo Molnar6471b822015-06-03 10:00:13 +020051 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
52 select ARCH_WANT_OPTIONAL_GPIOLIB
53 select BUILDTIME_EXTABLE_SORT
54 select CLKEVT_I8253
55 select CLKSRC_I8253 if X86_32
56 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
57 select CLOCKSOURCE_WATCHDOG
58 select CLONE_BACKWARDS if X86_32
59 select COMPAT_OLD_SIGACTION if IA32_EMULATION
60 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070061 select EDAC_ATOMIC_SCRUB
62 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020063 select GENERIC_CLOCKEVENTS
64 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
65 select GENERIC_CLOCKEVENTS_MIN_ADJUST
66 select GENERIC_CMOS_UPDATE
67 select GENERIC_CPU_AUTOPROBE
68 select GENERIC_EARLY_IOREMAP
69 select GENERIC_FIND_FIRST_BIT
70 select GENERIC_IOMAP
71 select GENERIC_IRQ_PROBE
72 select GENERIC_IRQ_SHOW
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_SMP_IDLE_THREAD
75 select GENERIC_STRNCPY_FROM_USER
76 select GENERIC_STRNLEN_USER
77 select GENERIC_TIME_VSYSCALL
78 select HAVE_ACPI_APEI if ACPI
79 select HAVE_ACPI_APEI_NMI if ACPI
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_AOUT if X86_32
82 select HAVE_ARCH_AUDITSYSCALL
83 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
84 select HAVE_ARCH_JUMP_LABEL
85 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
86 select HAVE_ARCH_KGDB
87 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080088 select HAVE_ARCH_MMAP_RND_BITS if MMU
89 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020090 select HAVE_ARCH_SECCOMP_FILTER
91 select HAVE_ARCH_SOFT_DIRTY if X86_64
92 select HAVE_ARCH_TRACEHOOK
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Daniel Borkmann60777762016-05-13 19:08:28 +020094 select HAVE_EBPF_JIT if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020095 select HAVE_CC_STACKPROTECTOR
96 select HAVE_CMPXCHG_DOUBLE
97 select HAVE_CMPXCHG_LOCAL
98 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -070099 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select HAVE_C_RECORDMCOUNT
101 select HAVE_DEBUG_KMEMLEAK
102 select HAVE_DEBUG_STACKOVERFLOW
103 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700104 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400105 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900106 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700107 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700108 select HAVE_EXIT_THREAD
Ingo Molnar6471b822015-06-03 10:00:13 +0200109 select HAVE_FENTRY if X86_64
110 select HAVE_FTRACE_MCOUNT_RECORD
111 select HAVE_FUNCTION_GRAPH_FP_TEST
112 select HAVE_FUNCTION_GRAPH_TRACER
113 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200114 select HAVE_GCC_PLUGINS
Ingo Molnar6471b822015-06-03 10:00:13 +0200115 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530116 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200117 select HAVE_IDE
118 select HAVE_IOREMAP_PROT
119 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
120 select HAVE_IRQ_TIME_ACCOUNTING
121 select HAVE_KERNEL_BZIP2
122 select HAVE_KERNEL_GZIP
123 select HAVE_KERNEL_LZ4
124 select HAVE_KERNEL_LZMA
125 select HAVE_KERNEL_LZO
126 select HAVE_KERNEL_XZ
127 select HAVE_KPROBES
128 select HAVE_KPROBES_ON_FTRACE
129 select HAVE_KRETPROBES
130 select HAVE_KVM
131 select HAVE_LIVEPATCH if X86_64
132 select HAVE_MEMBLOCK
133 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200134 select HAVE_MIXED_BREAKPOINTS_REGS
Petr Mladek42a0bb32016-05-20 17:00:33 -0700135 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200136 select HAVE_OPROFILE
137 select HAVE_OPTPROBES
138 select HAVE_PCSPKR_PLATFORM
139 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200140 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200141 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200142 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200143 select HAVE_REGS_AND_STACK_ACCESS_API
144 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400145 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300147 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100148 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200149 select MODULES_USE_ELF_RELA if X86_64
150 select MODULES_USE_ELF_REL if X86_32
151 select OLD_SIGACTION if X86_32
152 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
153 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500154 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200155 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500156 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200157 select SYSCTL_EXCEPTION_TRACE
158 select USER_STACKTRACE_SUPPORT
159 select VIRT_TO_BUS
160 select X86_DEV_DMA_OPS if X86_64
161 select X86_FEATURE_NAMES if PROC_FS
Josh Poimboeufd4883d52016-02-28 22:22:43 -0600162 select HAVE_STACK_VALIDATION if X86_64
Dave Hansen63c17fb2016-02-12 13:02:08 -0800163 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen66d37572016-02-12 13:02:32 -0800164 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530165
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200166config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100167 def_bool y
168 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200169
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700170config OUTPUT_FORMAT
171 string
172 default "elf32-i386" if X86_32
173 default "elf64-x86-64" if X86_64
174
Sam Ravnborg73531902008-05-25 23:03:18 +0200175config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200176 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200177 default "arch/x86/configs/i386_defconfig" if X86_32
178 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200179
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100180config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100181 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100182
183config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100184 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100185
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100186config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100187 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100188
Daniel Cashman9e08f572016-01-14 15:20:06 -0800189config ARCH_MMAP_RND_BITS_MIN
190 default 28 if 64BIT
191 default 8
192
193config ARCH_MMAP_RND_BITS_MAX
194 default 32 if 64BIT
195 default 16
196
197config ARCH_MMAP_RND_COMPAT_BITS_MIN
198 default 8
199
200config ARCH_MMAP_RND_COMPAT_BITS_MAX
201 default 16
202
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100203config SBUS
204 bool
205
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800206config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100207 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400208 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800209
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700210config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700211 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700212
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100213config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100214 def_bool y
215 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100216
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100217config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100218 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100219 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000220 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
221
222config GENERIC_BUG_RELATIVE_POINTERS
223 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100224
225config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100226 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100227
228config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100229 def_bool y
230 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100231
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100232config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100233 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100234
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100235config GENERIC_CALIBRATE_DELAY
236 def_bool y
237
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800238config ARCH_HAS_CPU_RELAX
239 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100240
Pekka Enberg1b27d052008-04-28 02:12:22 -0700241config ARCH_HAS_CACHE_LINE_SIZE
242 def_bool y
243
Mike Travisdd5af902008-01-30 13:33:32 +0100244config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900245 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100246
Tejun Heo08fc4582009-08-14 15:00:49 +0900247config NEED_PER_CPU_EMBED_FIRST_CHUNK
248 def_bool y
249
250config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900251 def_bool y
252
Johannes Berg801e4062007-12-08 02:12:39 +0100253config ARCH_HIBERNATION_POSSIBLE
254 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100255
Johannes Bergf4cb5702007-12-08 02:14:00 +0100256config ARCH_SUSPEND_POSSIBLE
257 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100258
Steve Cappercfe28c52013-04-29 14:29:48 +0100259config ARCH_WANT_HUGE_PMD_SHARE
260 def_bool y
261
Steve Capper53313b22013-04-30 08:03:42 +0100262config ARCH_WANT_GENERAL_HUGETLB
263 def_bool y
264
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100265config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000266 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100267
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100268config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000269 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100270
Ingo Molnar765c68b2008-04-09 11:03:37 +0200271config ARCH_SUPPORTS_OPTIMIZED_INLINING
272 def_bool y
273
Akinobu Mita6a11f752009-03-31 15:23:17 -0700274config ARCH_SUPPORTS_DEBUG_PAGEALLOC
275 def_bool y
276
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300277config KASAN_SHADOW_OFFSET
278 hex
279 depends on KASAN
280 default 0xdffffc0000000000
281
Shane Wang69575d32009-09-01 18:25:07 -0700282config HAVE_INTEL_TXT
283 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700284 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700285
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100286config X86_32_SMP
287 def_bool y
288 depends on X86_32 && SMP
289
290config X86_64_SMP
291 def_bool y
292 depends on X86_64 && SMP
293
Tejun Heoccbeed32009-02-09 22:17:40 +0900294config X86_32_LAZY_GS
295 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900296 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900297
Borislav Petkovd61931d2010-03-05 17:34:46 +0100298config ARCH_HWEIGHT_CFLAGS
299 string
300 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
301 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
302
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530303config ARCH_SUPPORTS_UPROBES
304 def_bool y
305
Rob Herringd20642f2014-04-18 17:19:54 -0500306config FIX_EARLYCON_MEM
307 def_bool y
308
Kees Cook9ccaf772016-02-17 14:41:14 -0800309config DEBUG_RODATA
310 def_bool y
311
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700312config PGTABLE_LEVELS
313 int
314 default 4 if X86_64
315 default 3 if X86_PAE
316 default 2
317
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100318source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700319source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100320
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100321menu "Processor type and features"
322
Randy Dunlap5ee71532012-01-16 11:57:18 -0800323config ZONE_DMA
324 bool "DMA memory allocation support" if EXPERT
325 default y
326 help
327 DMA memory allocation support allows devices with less than 32-bit
328 addressing to allocate within the first 16MB of address space.
329 Disable if no such devices will be used.
330
331 If unsure, say Y.
332
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100333config SMP
334 bool "Symmetric multi-processing support"
335 ---help---
336 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800337 a system with only one CPU, say N. If you have a system with more
338 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100339
Robert Graffham4a474152014-01-23 15:55:29 -0800340 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100341 machines, but will use only one CPU of a multiprocessor machine. If
342 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800343 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100344 will run faster if you say N here.
345
346 Note that if you say Y here and choose architecture "586" or
347 "Pentium" under "Processor family", the kernel will not work on 486
348 architectures. Similarly, multiprocessor kernels for the "PPro"
349 architecture may not work on all Pentium based boards.
350
351 People using multiprocessor machines who say Y here should also say
352 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
353 Management" code will be disabled if you say Y here.
354
Paul Bolle395cf962011-08-15 02:02:26 +0200355 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100356 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
357 <http://www.tldp.org/docs.html#howto>.
358
359 If you don't know what to do here, say N.
360
Josh Triplett9def39be2013-10-30 08:09:45 -0700361config X86_FEATURE_NAMES
362 bool "Processor feature human-readable names" if EMBEDDED
363 default y
364 ---help---
365 This option compiles in a table of x86 feature bits and corresponding
366 names. This is required to support /proc/cpuinfo and a few kernel
367 messages. You can disable this to save space, at the expense of
368 making those few kernel messages show numeric feature bits instead.
369
370 If in doubt, say Y.
371
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100372config X86_FAST_FEATURE_TESTS
373 bool "Fast CPU feature tests" if EMBEDDED
374 default y
375 ---help---
376 Some fast-paths in the kernel depend on the capabilities of the CPU.
377 Say Y here for the kernel to patch in the appropriate code at runtime
378 based on the capabilities of the CPU. The infrastructure for patching
379 code at runtime takes up some additional space; space-constrained
380 embedded systems may wish to say N here to produce smaller, slightly
381 slower code.
382
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800383config X86_X2APIC
384 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200385 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800386 ---help---
387 This enables x2apic support on CPUs that have this feature.
388
389 This allows 32-bit apic IDs (so it can support very large systems),
390 and accesses the local apic via MSRs not via mmio.
391
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800392 If you don't know what to do here, say N.
393
Yinghai Lu6695c852008-06-19 12:13:09 -0700394config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700395 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000396 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200397 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100398 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700399 For old smp systems that do not have proper acpi support. Newer systems
400 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700401
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800402config X86_BIGSMP
403 bool "Support for big SMP systems with more than 8 CPUs"
404 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100405 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800406 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100407
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000408config GOLDFISH
409 def_bool y
410 depends on X86_GOLDFISH
411
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800412if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800413config X86_EXTENDED_PLATFORM
414 bool "Support for extended (non-PC) x86 platforms"
415 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100416 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100417 If you disable this option then the kernel will only support
418 standard PC platforms. (which covers the vast majority of
419 systems out there.)
420
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800421 If you enable this option then you'll be able to select support
422 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100423 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800424 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800425 RDC R-321x SoC
426 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200427 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200428 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100429
430 If you have one of these systems, or if you want to build a
431 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800432endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100433
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800434if X86_64
435config X86_EXTENDED_PLATFORM
436 bool "Support for extended (non-PC) x86 platforms"
437 default y
438 ---help---
439 If you disable this option then the kernel will only support
440 standard PC platforms. (which covers the vast majority of
441 systems out there.)
442
443 If you enable this option then you'll be able to select support
444 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800445 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800446 ScaleMP vSMP
447 SGI Ultraviolet
448
449 If you have one of these systems, or if you want to build a
450 generic distribution kernel, say Y here - otherwise say N.
451endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800452# This is an alphabetically sorted list of 64 bit extended platforms
453# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800454config X86_NUMACHIP
455 bool "Numascale NumaChip"
456 depends on X86_64
457 depends on X86_EXTENDED_PLATFORM
458 depends on NUMA
459 depends on SMP
460 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700461 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800462 ---help---
463 Adds support for Numascale NumaChip large-SMP systems. Needed to
464 enable more than ~168 cores.
465 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100466
Ingo Molnar6a485652009-01-27 18:29:13 +0100467config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800468 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100469 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100470 select PARAVIRT
471 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800472 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300473 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100474 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100475 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
476 supposed to run on these EM64T-based machines. Only choose this option
477 if you have one of these machines.
478
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800479config X86_UV
480 bool "SGI Ultraviolet"
481 depends on X86_64
482 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500483 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800484 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700485 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200486 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800487 ---help---
488 This option is needed in order to support SGI Ultraviolet systems.
489 If you don't have one of these, you should say N here.
490
491# Following is an alphabetically sorted list of 32 bit extended platforms
492# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100493
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000494config X86_GOLDFISH
495 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100496 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000497 ---help---
498 Enable support for the Goldfish virtual platform used primarily
499 for Android development. Unless you are building for the Android
500 Goldfish emulator say N here.
501
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800502config X86_INTEL_CE
503 bool "CE4100 TV platform"
504 depends on PCI
505 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800506 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800507 depends on X86_32
508 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800509 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100510 select OF
511 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800512 ---help---
513 Select for the Intel CE media processor (CE4100) SOC.
514 This option compiles in support for the CE4100 SOC for settop
515 boxes and media devices.
516
David Cohen4cb9b002013-12-16 17:37:26 -0800517config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100518 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100519 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800520 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000521 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200522 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000523 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000524 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800525 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000526 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000527 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000528 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000529 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000530 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800531 Select to build a kernel capable of supporting Intel MID (Mobile
532 Internet Device) platform systems which do not have the PCI legacy
533 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000534
David Cohen4cb9b002013-12-16 17:37:26 -0800535 Intel MID platforms are based on an Intel processor and chipset which
536 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100537
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000538config X86_INTEL_QUARK
539 bool "Intel Quark platform support"
540 depends on X86_32
541 depends on X86_EXTENDED_PLATFORM
542 depends on X86_PLATFORM_DEVICES
543 depends on X86_TSC
544 depends on PCI
545 depends on PCI_GOANY
546 depends on X86_IO_APIC
547 select IOSF_MBI
548 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200549 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000550 ---help---
551 Select to include support for Quark X1000 SoC.
552 Say Y here if you have a Quark based system such as the Arduino
553 compatible Intel Galileo.
554
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000555config X86_INTEL_LPSS
556 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100557 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000558 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300559 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100560 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000561 ---help---
562 Select to build support for Intel Low Power Subsystem such as
563 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300564 things like clock tree (common clock framework) and pincontrol
565 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000566
Ken Xue92082a82015-02-06 08:27:51 +0800567config X86_AMD_PLATFORM_DEVICE
568 bool "AMD ACPI2Platform devices support"
569 depends on ACPI
570 select COMMON_CLK
571 select PINCTRL
572 ---help---
573 Select to interpret AMD specific ACPI device to platform device
574 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
575 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
576 implemented under PINCTRL subsystem.
577
David E. Boxced3ce72014-09-17 22:13:50 -0700578config IOSF_MBI
579 tristate "Intel SoC IOSF Sideband support for SoC platforms"
580 depends on PCI
581 ---help---
582 This option enables sideband register access support for Intel SoC
583 platforms. On these platforms the IOSF sideband is used in lieu of
584 MSR's for some register accesses, mostly but not limited to thermal
585 and power. Drivers may query the availability of this device to
586 determine if they need the sideband in order to work on these
587 platforms. The sideband is available on the following SoC products.
588 This list is not meant to be exclusive.
589 - BayTrail
590 - Braswell
591 - Quark
592
593 You should say Y if you are running a kernel on one of these SoC's.
594
David E. Boxed2226b2014-09-17 22:13:51 -0700595config IOSF_MBI_DEBUG
596 bool "Enable IOSF sideband access through debugfs"
597 depends on IOSF_MBI && DEBUG_FS
598 ---help---
599 Select this option to expose the IOSF sideband access registers (MCR,
600 MDR, MCRX) through debugfs to write and read register information from
601 different units on the SoC. This is most useful for obtaining device
602 state information for debug and analysis. As this is a general access
603 mechanism, users of this option would have specific knowledge of the
604 device they want to access.
605
606 If you don't require the option or are in doubt, say N.
607
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800608config X86_RDC321X
609 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100610 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800611 depends on X86_EXTENDED_PLATFORM
612 select M486
613 select X86_REBOOTFIXUPS
614 ---help---
615 This option is needed for RDC R-321x system-on-chip, also known
616 as R-8610-(G).
617 If you don't have one of these chips, you should say N here.
618
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100619config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100620 bool "Support non-standard 32-bit SMP architectures"
621 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800622 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100623 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800624 This option compiles in the bigsmp and STA2X11 default
625 subarchitectures. It is intended for a generic binary
626 kernel. If you select them all, kernel will probe it one by
627 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700628
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800629# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700630
Linus Torvaldsd949f362009-09-26 09:35:07 -0700631config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100632 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700633 # MCE code calls memory_failure():
634 depends on X86_MCE
635 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700636 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
637 depends on X86_64 || !SPARSEMEM
638 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700639
Alessandro Rubini83125a32012-04-04 19:40:21 +0200640config STA2X11
641 bool "STA2X11 Companion Chip Support"
642 depends on X86_32_NON_STANDARD && PCI
643 select X86_DEV_DMA_OPS
644 select X86_DMA_REMAP
645 select SWIOTLB
646 select MFD_STA2X11
647 select ARCH_REQUIRE_GPIOLIB
648 default n
649 ---help---
650 This adds support for boards based on the STA2X11 IO-Hub,
651 a.k.a. "ConneXt". The chip is used in place of the standard
652 PC chipset, so all "standard" peripherals are missing. If this
653 option is selected the kernel will still be able to boot on
654 standard PC machines.
655
Shérab82148d12010-09-25 06:06:57 +0200656config X86_32_IRIS
657 tristate "Eurobraille/Iris poweroff module"
658 depends on X86_32
659 ---help---
660 The Iris machines from EuroBraille do not have APM or ACPI support
661 to shut themselves down properly. A special I/O sequence is
662 needed to do so, which is what this module does at
663 kernel shutdown.
664
665 This is only for Iris machines from EuroBraille.
666
667 If unused, say N.
668
Ingo Molnarae1e9132008-11-11 09:05:16 +0100669config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100670 def_bool y
671 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800672 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100673 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100674 Calculate simpler /proc/<PID>/wchan values. If this option
675 is disabled then wchan values will recurse back to the
676 caller function. This provides more accurate wchan values,
677 at the expense of slightly more scheduling overhead.
678
679 If in doubt, say "Y".
680
Borislav Petkov6276a072013-03-04 21:20:21 +0100681menuconfig HYPERVISOR_GUEST
682 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100683 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100684 Say Y here to enable options for running Linux under various hyper-
685 visors. This option enables basic hypervisor detection and platform
686 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100687
Borislav Petkov6276a072013-03-04 21:20:21 +0100688 If you say N, all options in this submenu will be skipped and
689 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100690
Borislav Petkov6276a072013-03-04 21:20:21 +0100691if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100692
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100693config PARAVIRT
694 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100695 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100696 This changes the kernel so it can modify itself when it is run
697 under a hypervisor, potentially improving performance significantly
698 over full virtualization. However, when run without a hypervisor
699 the kernel is theoretically slower and slightly larger.
700
Borislav Petkov6276a072013-03-04 21:20:21 +0100701config PARAVIRT_DEBUG
702 bool "paravirt-ops debugging"
703 depends on PARAVIRT && DEBUG_KERNEL
704 ---help---
705 Enable to debug paravirt_ops internals. Specifically, BUG if
706 a paravirt_op is missing when it is called.
707
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700708config PARAVIRT_SPINLOCKS
709 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700710 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200711 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700712 ---help---
713 Paravirtualized spinlocks allow a pvops backend to replace the
714 spinlock implementation with something virtualization-friendly
715 (for example, block the virtual CPU rather than spinning).
716
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530717 It has a minimal impact on native kernels and gives a nice performance
718 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700719
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530720 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700721
Waiman Long45e898b2015-11-09 19:09:25 -0500722config QUEUED_LOCK_STAT
723 bool "Paravirt queued spinlock statistics"
724 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
725 ---help---
726 Enable the collection of statistical data on the slowpath
727 behavior of paravirtualized queued spinlocks and report
728 them on debugfs.
729
Borislav Petkov6276a072013-03-04 21:20:21 +0100730source "arch/x86/xen/Kconfig"
731
732config KVM_GUEST
733 bool "KVM Guest support (including kvmclock)"
734 depends on PARAVIRT
735 select PARAVIRT_CLOCK
736 default y
737 ---help---
738 This option enables various optimizations for running under the KVM
739 hypervisor. It includes a paravirtualized clock, so that instead
740 of relying on a PIT (or probably other) emulation by the
741 underlying device model, the host provides the guest with
742 timing infrastructure such as time of day, and system time
743
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530744config KVM_DEBUG_FS
745 bool "Enable debug information for KVM Guests in debugfs"
746 depends on KVM_GUEST && DEBUG_FS
747 default n
748 ---help---
749 This option enables collection of various statistics for KVM guest.
750 Statistics are displayed in debugfs filesystem. Enabling this option
751 may incur significant overhead.
752
Borislav Petkov6276a072013-03-04 21:20:21 +0100753source "arch/x86/lguest/Kconfig"
754
755config PARAVIRT_TIME_ACCOUNTING
756 bool "Paravirtual steal time accounting"
757 depends on PARAVIRT
758 default n
759 ---help---
760 Select this option to enable fine granularity task steal time
761 accounting. Time spent executing other tasks in parallel with
762 the current vCPU is discounted from the vCPU power. To account for
763 that, there can be a small performance impact.
764
765 If in doubt, say N here.
766
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200767config PARAVIRT_CLOCK
768 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200769
Borislav Petkov6276a072013-03-04 21:20:21 +0100770endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400771
Yinghai Lu08677212010-02-10 01:20:20 -0800772config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700773 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800774
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100775source "arch/x86/Kconfig.cpu"
776
777config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100778 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100779 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100780 ---help---
781 Use the IA-PC HPET (High Precision Event Timer) to manage
782 time in preference to the PIT and RTC, if a HPET is
783 present.
784 HPET is the next generation timer replacing legacy 8254s.
785 The HPET provides a stable time base on SMP
786 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200787 as it is off-chip. The interface used is documented
788 in the HPET spec, revision 1.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100789
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100790 You can safely choose Y here. However, HPET will only be
791 activated if the platform and the BIOS support this feature.
792 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100793
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100794 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100795
796config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100797 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800798 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100799
Jacob Panbb24c472009-09-02 07:37:17 -0700800config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000801 def_bool y if X86_INTEL_MID
802 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100803 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000804 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700805 help
806 APB timer is the replacement for 8254, HPET on X86 MID platforms.
807 The APBT provides a stable time base on SMP
808 systems, unlike the TSC, but it is more expensive to access,
809 as it is off-chip. APB timers are always running regardless of CPU
810 C states, they are used as per CPU clockevent device when possible.
811
David Rientjes6a108a12011-01-20 14:44:16 -0800812# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100813# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700814config DMI
815 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800816 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800817 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100818 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700819 Enabled scanning of DMI to identify machine quirks. Say Y
820 here unless you have verified that your setup is not
821 affected by entries in the DMI blacklist. Required by PNP
822 BIOS code.
823
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100824config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700825 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100826 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200827 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100828 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200829 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
830 GART based hardware IOMMUs.
831
832 The GART supports full DMA access for devices with 32-bit access
833 limitations, on systems with more than 3 GB. This is usually needed
834 for USB, sound, many IDE/SATA chipsets and some other devices.
835
836 Newer systems typically have a modern AMD IOMMU, supported via
837 the CONFIG_AMD_IOMMU=y config option.
838
839 In normal configurations this driver is only active when needed:
840 there's more than 3 GB of memory and the system contains a
841 32-bit limited device.
842
843 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100844
845config CALGARY_IOMMU
846 bool "IBM Calgary IOMMU support"
847 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700848 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100849 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100850 Support for hardware IOMMUs in IBM's xSeries x366 and x460
851 systems. Needed to run systems with more than 3GB of memory
852 properly with 32-bit PCI devices that do not support DAC
853 (Double Address Cycle). Calgary also supports bus level
854 isolation, where all DMAs pass through the IOMMU. This
855 prevents them from going anywhere except their intended
856 destination. This catches hard-to-find kernel bugs and
857 mis-behaving drivers and devices that do not use the DMA-API
858 properly to set up their DMA buffers. The IOMMU can be
859 turned off at boot time with the iommu=off parameter.
860 Normally the kernel will make the right choice by itself.
861 If unsure, say Y.
862
863config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100864 def_bool y
865 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100866 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100867 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100868 Should Calgary be enabled by default? if you choose 'y', Calgary
869 will be used (if it exists). If you choose 'n', Calgary will not be
870 used even if it exists. If you choose 'n' and would like to use
871 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
872 If unsure, say Y.
873
874# need this always selected by IOMMU for the VIA workaround
875config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100876 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100877 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100878 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700879 which don't have a hardware IOMMU. Using this PCI devices
880 which can only access 32-bits of memory can be used on systems
881 with more than 3 GB of memory.
882 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100883
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700884config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100885 def_bool y
886 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700887
Mike Travis1184dc22008-05-12 21:21:12 +0200888config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200889 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700890 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800891 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100892 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200893 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200894 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100895
896config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800897 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400898 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500899 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500900 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800901 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500902 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800903 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300904 default "8" if SMP && X86_32
905 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100906 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100907 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500908 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300909 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100910 minimum value which makes sense is 2.
911
912 This is purely to save memory - each supported CPU adds
913 approximately eight kilobytes to the kernel image.
914
915config SCHED_SMT
916 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200917 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100918 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100919 SMT scheduler support improves the CPU scheduler's decision making
920 when dealing with Intel Pentium 4 chips with HyperThreading at a
921 cost of slightly increased overhead in some places. If unsure say
922 N here.
923
924config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100925 def_bool y
926 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200927 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100928 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100929 Multi-core scheduler support improves the CPU scheduler's decision
930 making when dealing with multi-core CPU chips at a cost of slightly
931 increased overhead in some places. If unsure say N here.
932
933source "kernel/Kconfig.preempt"
934
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000935config UP_LATE_INIT
936 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100937 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000938
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100939config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000940 bool "Local APIC support on uniprocessors" if !PCI_MSI
941 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000942 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100943 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100944 A local APIC (Advanced Programmable Interrupt Controller) is an
945 integrated interrupt controller in the CPU. If you have a single-CPU
946 system which has a processor with a local APIC, you can say Y here to
947 enable and use it. If you say Y here even though your machine doesn't
948 have a local APIC, then the kernel will still run with no slowdown at
949 all. The local APIC supports CPU-generated self-interrupts (timer,
950 performance counters), and the NMI watchdog which detects hard
951 lockups.
952
953config X86_UP_IOAPIC
954 bool "IO-APIC support on uniprocessors"
955 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100956 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100957 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
958 SMP-capable replacement for PC-style interrupt controllers. Most
959 SMP systems and many recent uniprocessor systems have one.
960
961 If you have a single-CPU system with an IO-APIC, you can say Y here
962 to use it. If you say Y here even though your machine doesn't have
963 an IO-APIC, then the kernel will still run with no slowdown at all.
964
965config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100966 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200967 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800968 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800969 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100970
971config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000972 def_bool y
973 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100974
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200975config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
976 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200977 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100978 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200979 This option enables a workaround that fixes a source of
980 spurious interrupts. This is recommended when threaded
981 interrupt handling is used on systems where the generation of
982 superfluous "boot interrupts" cannot be disabled.
983
984 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
985 entry in the chipset's IO-APIC is masked (as, e.g. the RT
986 kernel does during interrupt handling). On chipsets where this
987 boot IRQ generation cannot be disabled, this workaround keeps
988 the original IRQ line masked so that only the equivalent "boot
989 IRQ" is delivered to the CPUs. The workaround also tells the
990 kernel to set up the IRQ handler on the boot IRQ line. In this
991 way only one interrupt is delivered to the kernel. Otherwise
992 the spurious second interrupt may cause the kernel to bring
993 down (vital) interrupt lines.
994
995 Only affects "broken" chipsets. Interrupt sharing may be
996 increased on these systems.
997
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100998config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +0200999 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001000 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001001 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001002 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001003 Machine Check support allows the processor to notify the
1004 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001005 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001006 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001007
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001008config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001009 def_bool y
1010 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001011 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001012 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001013 Additional support for intel specific MCE features such as
1014 the thermal monitor.
1015
1016config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001017 def_bool y
1018 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001019 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001020 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001021 Additional support for AMD specific MCE features such as
1022 the DRAM Error Threshold.
1023
Andi Kleen4efc0672009-04-28 19:07:31 +02001024config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001025 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001026 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001027 ---help---
1028 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001029 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001030 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001031
Andi Kleenb2762682009-02-12 13:49:31 +01001032config X86_MCE_THRESHOLD
1033 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001034 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001035
Andi Kleenea149b32009-04-29 19:31:00 +02001036config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001037 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001038 tristate "Machine check injector support"
1039 ---help---
1040 Provide support for injecting machine checks for testing purposes.
1041 If you don't know what a machine check is and you don't do kernel
1042 QA it is safe to say n.
1043
Andi Kleen4efc0672009-04-28 19:07:31 +02001044config X86_THERMAL_VECTOR
1045 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001046 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001047
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001048source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001049
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001050config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001051 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001052 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001053 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001054 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001055 This option allows user programs to put the CPU into V8086
1056 mode, which is an 80286-era approximation of 16-bit real mode.
1057
1058 Some very old versions of X and/or vbetool require this option
1059 for user mode setting. Similarly, DOSEMU will use it if
1060 available to accelerate real mode DOS programs. However, any
1061 recent version of DOSEMU, X, or vbetool should be fully
1062 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001063 fall back to software emulation. Nevertheless, if you are using
1064 a 16-bit DOS program where 16-bit performance matters, vm86
1065 mode might be faster than emulation and you might want to
1066 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001067
Ingo Molnar1e642812015-09-05 08:58:10 +02001068 Note that any app that works on a 64-bit kernel is unlikely to
1069 need this option, as 64-bit kernels don't, and can't, support
1070 V8086 mode. This option is also unrelated to 16-bit protected
1071 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001072
Ingo Molnar1e642812015-09-05 08:58:10 +02001073 Enabling this option increases the complexity of the kernel
1074 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001075
Ingo Molnar1e642812015-09-05 08:58:10 +02001076 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001077
1078config VM86
1079 bool
1080 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001081
1082config X86_16BIT
1083 bool "Enable support for 16-bit segments" if EXPERT
1084 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001085 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001086 ---help---
1087 This option is required by programs like Wine to run 16-bit
1088 protected mode legacy code on x86 processors. Disabling
1089 this option saves about 300 bytes on i386, or around 6K text
1090 plus 16K runtime memory on x86-64,
1091
1092config X86_ESPFIX32
1093 def_bool y
1094 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001095
H. Peter Anvin197725d2014-05-04 10:00:49 -07001096config X86_ESPFIX64
1097 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001098 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001099
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001100config X86_VSYSCALL_EMULATION
1101 bool "Enable vsyscall emulation" if EXPERT
1102 default y
1103 depends on X86_64
1104 ---help---
1105 This enables emulation of the legacy vsyscall page. Disabling
1106 it is roughly equivalent to booting with vsyscall=none, except
1107 that it will also disable the helpful warning if a program
1108 tries to use a vsyscall. With this option set to N, offending
1109 programs will just segfault, citing addresses of the form
1110 0xffffffffff600?00.
1111
1112 This option is required by many programs built before 2013, and
1113 care should be used even with newer programs if set to N.
1114
1115 Disabling this option saves about 7K of kernel size and
1116 possibly 4K of additional runtime pagetable memory.
1117
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001118config TOSHIBA
1119 tristate "Toshiba Laptop support"
1120 depends on X86_32
1121 ---help---
1122 This adds a driver to safely access the System Management Mode of
1123 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1124 not work on models with a Phoenix BIOS. The System Management Mode
1125 is used to set the BIOS and power saving options on Toshiba portables.
1126
1127 For information on utilities to make use of this driver see the
1128 Toshiba Linux utilities web site at:
1129 <http://www.buzzard.org.uk/toshiba/>.
1130
1131 Say Y if you intend to run this kernel on a Toshiba portable.
1132 Say N otherwise.
1133
1134config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001135 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001136 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001137 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001138 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001139 This option enables legacy /proc/i8k userspace interface in hwmon
1140 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1141 temperature and allows controlling fan speeds of Dell laptops via
1142 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1143 it reports also power and hotkey status. For fan speed control is
1144 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001145
Pali Rohár039ae582015-05-14 13:16:37 +02001146 Say Y if you intend to run this kernel on old Dell laptops or want to
1147 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001148 Say N otherwise.
1149
1150config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001151 bool "Enable X86 board specific fixups for reboot"
1152 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001153 ---help---
1154 This enables chipset and/or board specific fixups to be done
1155 in order to get reboot to work correctly. This is only needed on
1156 some combinations of hardware and BIOS. The symptom, for which
1157 this config is intended, is when reboot ends with a stalled/hung
1158 system.
1159
1160 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001161 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001162
1163 Say Y if you want to enable the fixup. Currently, it's safe to
1164 enable this option even if you don't need it.
1165 Say N otherwise.
1166
1167config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001168 bool "CPU microcode loading support"
1169 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001170 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001171 select FW_LOADER
1172 ---help---
1173 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001174 Intel and AMD processors. The Intel support is for the IA32 family,
1175 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1176 AMD support is for families 0x10 and later. You will obviously need
1177 the actual microcode binary data itself which is not shipped with
1178 the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001179
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001180 The preferred method to load microcode from a detached initrd is described
1181 in Documentation/x86/early-microcode.txt. For that you need to enable
1182 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1183 initrd for microcode blobs.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001184
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001185 In addition, you can build-in the microcode into the kernel. For that you
1186 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1187 to the CONFIG_EXTRA_FIRMWARE config option.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001188
Peter Oruba8d86f392008-07-28 18:44:21 +02001189config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001190 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001191 depends on MICROCODE
1192 default MICROCODE
1193 select FW_LOADER
1194 ---help---
1195 This options enables microcode patch loading support for Intel
1196 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001197
Alanb8989db2014-01-20 18:01:56 +00001198 For the current Intel microcode data package go to
1199 <https://downloadcenter.intel.com> and search for
1200 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001201
Peter Oruba80cc9f12008-07-28 18:44:22 +02001202config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001203 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001204 depends on MICROCODE
1205 select FW_LOADER
1206 ---help---
1207 If you select this option, microcode patch loading support for AMD
1208 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001209
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001210config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001211 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001212 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001213
1214config X86_MSR
1215 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001216 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001217 This device gives privileged processes access to the x86
1218 Model-Specific Registers (MSRs). It is a character device with
1219 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1220 MSR accesses are directed to a specific CPU on multi-processor
1221 systems.
1222
1223config X86_CPUID
1224 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001225 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001226 This device gives processes access to the x86 CPUID instruction to
1227 be executed on a specific processor. It is a character device
1228 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1229 /dev/cpu/31/cpuid.
1230
1231choice
1232 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001233 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001234 depends on X86_32
1235
1236config NOHIGHMEM
1237 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001238 ---help---
1239 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1240 However, the address space of 32-bit x86 processors is only 4
1241 Gigabytes large. That means that, if you have a large amount of
1242 physical memory, not all of it can be "permanently mapped" by the
1243 kernel. The physical memory that's not permanently mapped is called
1244 "high memory".
1245
1246 If you are compiling a kernel which will never run on a machine with
1247 more than 1 Gigabyte total physical RAM, answer "off" here (default
1248 choice and suitable for most users). This will result in a "3GB/1GB"
1249 split: 3GB are mapped so that each process sees a 3GB virtual memory
1250 space and the remaining part of the 4GB virtual memory space is used
1251 by the kernel to permanently map as much physical memory as
1252 possible.
1253
1254 If the machine has between 1 and 4 Gigabytes physical RAM, then
1255 answer "4GB" here.
1256
1257 If more than 4 Gigabytes is used then answer "64GB" here. This
1258 selection turns Intel PAE (Physical Address Extension) mode on.
1259 PAE implements 3-level paging on IA32 processors. PAE is fully
1260 supported by Linux, PAE mode is implemented on all recent Intel
1261 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1262 then the kernel will not boot on CPUs that don't support PAE!
1263
1264 The actual amount of total physical memory will either be
1265 auto detected or can be forced by using a kernel command line option
1266 such as "mem=256M". (Try "man bootparam" or see the documentation of
1267 your boot loader (lilo or loadlin) about how to pass options to the
1268 kernel at boot time.)
1269
1270 If unsure, say "off".
1271
1272config HIGHMEM4G
1273 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001274 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001275 Select this if you have a 32-bit processor and between 1 and 4
1276 gigabytes of physical RAM.
1277
1278config HIGHMEM64G
1279 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001280 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001281 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001282 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001283 Select this if you have a 32-bit processor and more than 4
1284 gigabytes of physical RAM.
1285
1286endchoice
1287
1288choice
David Rientjes6a108a12011-01-20 14:44:16 -08001289 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001290 default VMSPLIT_3G
1291 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001292 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001293 Select the desired split between kernel and user memory.
1294
1295 If the address range available to the kernel is less than the
1296 physical memory installed, the remaining memory will be available
1297 as "high memory". Accessing high memory is a little more costly
1298 than low memory, as it needs to be mapped into the kernel first.
1299 Note that increasing the kernel address space limits the range
1300 available to user programs, making the address space there
1301 tighter. Selecting anything other than the default 3G/1G split
1302 will also likely make your kernel incompatible with binary-only
1303 kernel modules.
1304
1305 If you are not absolutely sure what you are doing, leave this
1306 option alone!
1307
1308 config VMSPLIT_3G
1309 bool "3G/1G user/kernel split"
1310 config VMSPLIT_3G_OPT
1311 depends on !X86_PAE
1312 bool "3G/1G user/kernel split (for full 1G low memory)"
1313 config VMSPLIT_2G
1314 bool "2G/2G user/kernel split"
1315 config VMSPLIT_2G_OPT
1316 depends on !X86_PAE
1317 bool "2G/2G user/kernel split (for full 2G low memory)"
1318 config VMSPLIT_1G
1319 bool "1G/3G user/kernel split"
1320endchoice
1321
1322config PAGE_OFFSET
1323 hex
1324 default 0xB0000000 if VMSPLIT_3G_OPT
1325 default 0x80000000 if VMSPLIT_2G
1326 default 0x78000000 if VMSPLIT_2G_OPT
1327 default 0x40000000 if VMSPLIT_1G
1328 default 0xC0000000
1329 depends on X86_32
1330
1331config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001332 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001333 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001334
1335config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001336 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001337 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001338 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001339 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001340 PAE is required for NX support, and furthermore enables
1341 larger swapspace support for non-overcommit purposes. It
1342 has the cost of more pagetable lookup overhead, and also
1343 consumes more pagetable space per process.
1344
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001345config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001346 def_bool y
1347 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001348
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001349config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001350 def_bool y
1351 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001352
Ingo Molnar10971ab2015-03-05 08:18:23 +01001353config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001354 def_bool y
1355 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001356 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001357 Certain kernel features effectively disable kernel
1358 linear 1 GB mappings (even if the CPU otherwise
1359 supports them), so don't confuse the user by printing
1360 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001361
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001362# Common NUMA Features
1363config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001364 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001365 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001366 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1367 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001368 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001369 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001370
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001371 The kernel will try to allocate memory used by a CPU on the
1372 local memory controller of the CPU and add some more
1373 NUMA awareness to the kernel.
1374
Ingo Molnarc280ea52008-11-08 13:29:45 +01001375 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001376 (or later), AMD Opteron, or EM64T NUMA.
1377
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001378 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001379 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001380
1381 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001382
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001383config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001384 def_bool y
1385 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001386 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001387 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001388 Enable AMD NUMA node topology detection. You should say Y here if
1389 you have a multi processor AMD system. This uses an old method to
1390 read the NUMA configuration directly from the builtin Northbridge
1391 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1392 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001393
1394config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001395 def_bool y
1396 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001397 depends on X86_64 && NUMA && ACPI && PCI
1398 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001399 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001400 Enable ACPI SRAT based node topology detection.
1401
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001402# Some NUMA nodes have memory ranges that span
1403# other nodes. Even though a pfn is valid and
1404# between a node's start and end pfns, it may not
1405# reside on that node. See memmap_init_zone()
1406# for details.
1407config NODES_SPAN_OTHER_NODES
1408 def_bool y
1409 depends on X86_64_ACPI_NUMA
1410
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001411config NUMA_EMU
1412 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001413 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001414 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001415 Enable NUMA emulation. A flat machine will be split
1416 into virtual nodes when booted with "numa=fake=N", where N is the
1417 number of nodes. This is only useful for debugging.
1418
1419config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001420 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001421 range 1 10
1422 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001423 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001424 default "3"
1425 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001426 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001427 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001428 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001429
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001430config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001431 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001432 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001433
1434config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001435 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001436 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001437
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001438config ARCH_FLATMEM_ENABLE
1439 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001440 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001441
1442config ARCH_DISCONTIGMEM_ENABLE
1443 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001444 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001445
1446config ARCH_DISCONTIGMEM_DEFAULT
1447 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001448 depends on NUMA && X86_32
1449
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001450config ARCH_SPARSEMEM_ENABLE
1451 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001452 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001453 select SPARSEMEM_STATIC if X86_32
1454 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1455
Tejun Heo3b166512011-04-01 11:15:12 +02001456config ARCH_SPARSEMEM_DEFAULT
1457 def_bool y
1458 depends on X86_64
1459
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001460config ARCH_SELECT_MEMORY_MODEL
1461 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001462 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001463
1464config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001465 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001466 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001467 help
1468 This option enables a sysfs memory/probe interface for testing.
1469 See Documentation/memory-hotplug.txt for more information.
1470 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001471
Tejun Heo3b166512011-04-01 11:15:12 +02001472config ARCH_PROC_KCORE_TEXT
1473 def_bool y
1474 depends on X86_64 && PROC_KCORE
1475
Avi Kivitya29815a2010-01-10 16:28:09 +02001476config ILLEGAL_POINTER_VALUE
1477 hex
1478 default 0 if X86_32
1479 default 0xdead000000000000 if X86_64
1480
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001481source "mm/Kconfig"
1482
Dan Williams7a678322015-08-19 00:34:34 -04001483config X86_PMEM_LEGACY_DEVICE
1484 bool
1485
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001486config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001487 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001488 depends on PHYS_ADDR_T_64BIT
1489 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001490 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001491 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001492 help
1493 Treat memory marked using the non-standard e820 type of 12 as used
1494 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1495 The kernel will offer these regions to the 'pmem' driver so
1496 they can be used for persistent storage.
1497
1498 Say Y if unsure.
1499
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001500config HIGHPTE
1501 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001502 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001503 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001504 The VM uses one page table entry for each page of physical memory.
1505 For systems with a lot of RAM, this can be wasteful of precious
1506 low memory. Setting this option will put user-space page table
1507 entries in high memory.
1508
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001509config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001510 bool "Check for low memory corruption"
1511 ---help---
1512 Periodically check for memory corruption in low memory, which
1513 is suspected to be caused by BIOS. Even when enabled in the
1514 configuration, it is disabled at runtime. Enable it by
1515 setting "memory_corruption_check=1" on the kernel command
1516 line. By default it scans the low 64k of memory every 60
1517 seconds; see the memory_corruption_check_size and
1518 memory_corruption_check_period parameters in
1519 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001520
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001521 When enabled with the default parameters, this option has
1522 almost no overhead, as it reserves a relatively small amount
1523 of memory and scans it infrequently. It both detects corruption
1524 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001525
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001526 It is, however, intended as a diagnostic tool; if repeatable
1527 BIOS-originated corruption always affects the same memory,
1528 you can use memmap= to prevent the kernel from using that
1529 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001530
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001531config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001532 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001533 depends on X86_CHECK_BIOS_CORRUPTION
1534 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001535 ---help---
1536 Set whether the default state of memory_corruption_check is
1537 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001538
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001539config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001540 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1541 default 64
1542 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001543 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001544 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001545
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001546 The first page contains BIOS data structures that the kernel
1547 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001548
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001549 By default we reserve the first 64K of physical RAM, as a
1550 number of BIOSes are known to corrupt that memory range
1551 during events such as suspend/resume or monitor cable
1552 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001553
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001554 You can set this to 4 if you are absolutely sure that you
1555 trust the BIOS to get all its memory reservations and usages
1556 right. If you know your BIOS have problems beyond the
1557 default 64K area, you can set this to 640 to avoid using the
1558 entire low memory range.
1559
1560 If you have doubts about the BIOS (e.g. suspend/resume does
1561 not work or there's kernel crashes after certain hardware
1562 hotplug events) then you might want to enable
1563 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1564 typical corruption patterns.
1565
1566 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001567
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001568config MATH_EMULATION
1569 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001570 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001571 prompt "Math emulation" if X86_32
1572 ---help---
1573 Linux can emulate a math coprocessor (used for floating point
1574 operations) if you don't have one. 486DX and Pentium processors have
1575 a math coprocessor built in, 486SX and 386 do not, unless you added
1576 a 487DX or 387, respectively. (The messages during boot time can
1577 give you some hints here ["man dmesg"].) Everyone needs either a
1578 coprocessor or this emulation.
1579
1580 If you don't have a math coprocessor, you need to say Y here; if you
1581 say Y here even though you have a coprocessor, the coprocessor will
1582 be used nevertheless. (This behavior can be changed with the kernel
1583 command line option "no387", which comes handy if your coprocessor
1584 is broken. Try "man bootparam" or see the documentation of your boot
1585 loader (lilo or loadlin) about how to pass options to the kernel at
1586 boot time.) This means that it is a good idea to say Y here if you
1587 intend to use this kernel on different machines.
1588
1589 More information about the internals of the Linux math coprocessor
1590 emulation can be found in <file:arch/x86/math-emu/README>.
1591
1592 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1593 kernel, it won't hurt.
1594
1595config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001596 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001597 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001598 ---help---
1599 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1600 the Memory Type Range Registers (MTRRs) may be used to control
1601 processor access to memory ranges. This is most useful if you have
1602 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1603 allows bus write transfers to be combined into a larger transfer
1604 before bursting over the PCI/AGP bus. This can increase performance
1605 of image write operations 2.5 times or more. Saying Y here creates a
1606 /proc/mtrr file which may be used to manipulate your processor's
1607 MTRRs. Typically the X server should use this.
1608
1609 This code has a reasonably generic interface so that similar
1610 control registers on other processors can be easily supported
1611 as well:
1612
1613 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1614 Registers (ARRs) which provide a similar functionality to MTRRs. For
1615 these, the ARRs are used to emulate the MTRRs.
1616 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1617 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1618 write-combining. All of these processors are supported by this code
1619 and it makes sense to say Y here if you have one of them.
1620
1621 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1622 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1623 can lead to all sorts of problems, so it's good to say Y here.
1624
1625 You can safely say Y even if your machine doesn't have MTRRs, you'll
1626 just add about 9 KB to your kernel.
1627
Randy Dunlap7225e752008-07-26 17:54:22 -07001628 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001629
Yinghai Lu95ffa242008-04-29 03:52:33 -07001630config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001631 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001632 prompt "MTRR cleanup support"
1633 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001634 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001635 Convert MTRR layout from continuous to discrete, so X drivers can
1636 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001637
Thomas Gleixneraba37282008-07-15 14:48:48 +02001638 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001639 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001640 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001641
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001642 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001643
1644config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001645 int "MTRR cleanup enable value (0-1)"
1646 range 0 1
1647 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001648 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001649 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001650 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001651
Yinghai Lu12031a62008-05-02 02:40:22 -07001652config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1653 int "MTRR cleanup spare reg num (0-7)"
1654 range 0 7
1655 default "1"
1656 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001657 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001658 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001659 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001660
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001661config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001662 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001663 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001664 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001665 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001666 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001667
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001668 PATs are the modern equivalents of MTRRs and are much more
1669 flexible than MTRRs.
1670
1671 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001672 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001673
1674 If unsure, say Y.
1675
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001676config ARCH_USES_PG_UNCACHED
1677 def_bool y
1678 depends on X86_PAT
1679
H. Peter Anvin628c6242011-07-31 13:59:29 -07001680config ARCH_RANDOM
1681 def_bool y
1682 prompt "x86 architectural random number generator" if EXPERT
1683 ---help---
1684 Enable the x86 architectural RDRAND instruction
1685 (Intel Bull Mountain technology) to generate random numbers.
1686 If supported, this is a high bandwidth, cryptographically
1687 secure hardware random number generator.
1688
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001689config X86_SMAP
1690 def_bool y
1691 prompt "Supervisor Mode Access Prevention" if EXPERT
1692 ---help---
1693 Supervisor Mode Access Prevention (SMAP) is a security
1694 feature in newer Intel processors. There is a small
1695 performance cost if this enabled and turned on; there is
1696 also a small increase in the kernel size if this is enabled.
1697
1698 If unsure, say Y.
1699
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001700config X86_INTEL_MPX
1701 prompt "Intel MPX (Memory Protection Extensions)"
1702 def_bool n
1703 depends on CPU_SUP_INTEL
1704 ---help---
1705 MPX provides hardware features that can be used in
1706 conjunction with compiler-instrumented code to check
1707 memory references. It is designed to detect buffer
1708 overflow or underflow bugs.
1709
1710 This option enables running applications which are
1711 instrumented or otherwise use MPX. It does not use MPX
1712 itself inside the kernel or to protect the kernel
1713 against bad memory references.
1714
1715 Enabling this option will make the kernel larger:
1716 ~8k of kernel text and 36 bytes of data on a 64-bit
1717 defconfig. It adds a long to the 'mm_struct' which
1718 will increase the kernel memory overhead of each
1719 process and adds some branches to paths used during
1720 exec() and munmap().
1721
1722 For details, see Documentation/x86/intel_mpx.txt
1723
1724 If unsure, say N.
1725
Dave Hansen35e97792016-02-12 13:02:00 -08001726config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001727 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001728 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001729 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001730 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001731 ---help---
1732 Memory Protection Keys provides a mechanism for enforcing
1733 page-based protections, but without requiring modification of the
1734 page tables when an application changes protection domains.
1735
1736 For details, see Documentation/x86/protection-keys.txt
1737
1738 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001739
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001740config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001741 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001742 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001743 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001744 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001745 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001746 This enables the kernel to use EFI runtime services that are
1747 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001748
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001749 This option is only useful on systems that have EFI firmware.
1750 In addition, you should use the latest ELILO loader available
1751 at <http://elilo.sourceforge.net> in order to take advantage
1752 of EFI runtime services. However, even with this option, the
1753 resultant kernel should continue to boot on existing non-EFI
1754 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001755
Matt Fleming291f3632011-12-12 21:27:52 +00001756config EFI_STUB
1757 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001758 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001759 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001760 ---help---
1761 This kernel feature allows a bzImage to be loaded directly
1762 by EFI firmware without the use of a bootloader.
1763
Roy Franz4172fe22013-09-22 15:45:25 -07001764 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001765
Matt Fleming7d453ee2014-01-10 18:52:06 +00001766config EFI_MIXED
1767 bool "EFI mixed-mode support"
1768 depends on EFI_STUB && X86_64
1769 ---help---
1770 Enabling this feature allows a 64-bit kernel to be booted
1771 on a 32-bit firmware, provided that your CPU supports 64-bit
1772 mode.
1773
1774 Note that it is not possible to boot a mixed-mode enabled
1775 kernel via the EFI boot stub - a bootloader that supports
1776 the EFI handover protocol must be used.
1777
1778 If unsure, say N.
1779
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001780config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001781 def_bool y
1782 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001783 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001784 This kernel feature is useful for number crunching applications
1785 that may need to compute untrusted bytecode during their
1786 execution. By using pipes or other transports made available to
1787 the process as file descriptors supporting the read/write
1788 syscalls, it's possible to isolate those applications in
1789 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001790 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001791 and the task is only allowed to execute a few safe syscalls
1792 defined by each seccomp mode.
1793
1794 If unsure, say Y. Only embedded should say N here.
1795
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001796source kernel/Kconfig.hz
1797
1798config KEXEC
1799 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001800 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001801 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001802 kexec is a system call that implements the ability to shutdown your
1803 current kernel, and to start another kernel. It is like a reboot
1804 but it is independent of the system firmware. And like a reboot
1805 you can start any kernel with it, not just Linux.
1806
1807 The name comes from the similarity to the exec system call.
1808
1809 It is an ongoing process to be certain the hardware in a machine
1810 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001811 initially work for you. As of this writing the exact hardware
1812 interface is strongly in flux, so no good recommendation can be
1813 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001814
Vivek Goyal74ca3172014-08-29 15:18:46 -07001815config KEXEC_FILE
1816 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001817 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001818 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001819 depends on X86_64
1820 depends on CRYPTO=y
1821 depends on CRYPTO_SHA256=y
1822 ---help---
1823 This is new version of kexec system call. This system call is
1824 file based and takes file descriptors as system call argument
1825 for kernel and initramfs as opposed to list of segments as
1826 accepted by previous system call.
1827
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001828config KEXEC_VERIFY_SIG
1829 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001830 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001831 ---help---
1832 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001833 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001834
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001835 In addition to that option, you need to enable signature
1836 verification for the corresponding kernel image type being
1837 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001838
1839config KEXEC_BZIMAGE_VERIFY_SIG
1840 bool "Enable bzImage signature verification support"
1841 depends on KEXEC_VERIFY_SIG
1842 depends on SIGNED_PE_FILE_VERIFICATION
1843 select SYSTEM_TRUSTED_KEYRING
1844 ---help---
1845 Enable bzImage signature verification support.
1846
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001847config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001848 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001849 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001850 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001851 Generate crash dump after being started by kexec.
1852 This should be normally only set in special crash dump kernels
1853 which are loaded in the main kernel with kexec-tools into
1854 a specially reserved region and then later executed after
1855 a crash by kdump/kexec. The crash dump kernel must be compiled
1856 to a memory address not used by the main kernel or BIOS using
1857 PHYSICAL_START, or it must be built as a relocatable image
1858 (CONFIG_RELOCATABLE=y).
1859 For more details see Documentation/kdump/kdump.txt
1860
Huang Ying3ab83522008-07-25 19:45:07 -07001861config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001862 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001863 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001864 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001865 Jump between original kernel and kexeced kernel and invoke
1866 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001867
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001868config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001869 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001870 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001871 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001872 This gives the physical address where the kernel is loaded.
1873
1874 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1875 bzImage will decompress itself to above physical address and
1876 run from there. Otherwise, bzImage will run from the address where
1877 it has been loaded by the boot loader and will ignore above physical
1878 address.
1879
1880 In normal kdump cases one does not have to set/change this option
1881 as now bzImage can be compiled as a completely relocatable image
1882 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1883 address. This option is mainly useful for the folks who don't want
1884 to use a bzImage for capturing the crash dump and want to use a
1885 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1886 to be specifically compiled to run from a specific memory area
1887 (normally a reserved region) and this option comes handy.
1888
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001889 So if you are using bzImage for capturing the crash dump,
1890 leave the value here unchanged to 0x1000000 and set
1891 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1892 for capturing the crash dump change this value to start of
1893 the reserved region. In other words, it can be set based on
1894 the "X" value as specified in the "crashkernel=YM@XM"
1895 command line boot parameter passed to the panic-ed
1896 kernel. Please take a look at Documentation/kdump/kdump.txt
1897 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001898
1899 Usage of bzImage for capturing the crash dump is recommended as
1900 one does not have to build two kernels. Same kernel can be used
1901 as production kernel and capture kernel. Above option should have
1902 gone away after relocatable bzImage support is introduced. But it
1903 is present because there are users out there who continue to use
1904 vmlinux for dump capture. This option should go away down the
1905 line.
1906
1907 Don't change this unless you know what you are doing.
1908
1909config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001910 bool "Build a relocatable kernel"
1911 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001912 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001913 This builds a kernel image that retains relocation information
1914 so it can be loaded someplace besides the default 1MB.
1915 The relocations tend to make the kernel binary about 10% larger,
1916 but are discarded at runtime.
1917
1918 One use is for the kexec on panic case where the recovery kernel
1919 must live at a different physical address than the primary
1920 kernel.
1921
1922 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1923 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001924 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001925
Kees Cook8ab38202013-10-10 17:18:14 -07001926config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07001927 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07001928 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001929 default n
1930 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07001931 In support of Kernel Address Space Layout Randomization (KASLR),
1932 this randomizes the physical address at which the kernel image
1933 is decompressed and the virtual address where the kernel
1934 image is mapped, as a security feature that deters exploit
1935 attempts relying on knowledge of the location of kernel
1936 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07001937
Baoquan Hee8581e32016-04-20 13:55:43 -07001938 The kernel physical and virtual address can be randomized
1939 from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
1940 using RANDOMIZE_BASE reduces the memory space available to
1941 kernel modules from 1.5GB to 1GB.)
Kees Cook8ab38202013-10-10 17:18:14 -07001942
Baoquan Hee8581e32016-04-20 13:55:43 -07001943 Entropy is generated using the RDRAND instruction if it is
1944 supported. If RDTSC is supported, its value is mixed into
1945 the entropy pool as well. If neither RDRAND nor RDTSC are
1946 supported, then entropy is read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001947
Baoquan Hee8581e32016-04-20 13:55:43 -07001948 Since the kernel is built using 2GB addressing, and
1949 PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
1950 entropy is theoretically possible. Currently, with the
1951 default value for PHYSICAL_ALIGN and due to page table
1952 layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
Kees Cookda2b6fb2013-12-10 12:27:45 -08001953
Baoquan Hee8581e32016-04-20 13:55:43 -07001954 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1955 time. To enable it, boot with "kaslr" on the kernel command
1956 line (which will also disable hibernation).
Kees Cook6145cfe2013-10-10 17:18:18 -07001957
Baoquan Hee8581e32016-04-20 13:55:43 -07001958 If unsure, say N.
Kees Cook8ab38202013-10-10 17:18:14 -07001959
1960# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001961config X86_NEED_RELOCS
1962 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001963 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001964
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001965config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001966 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001967 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001968 range 0x2000 0x1000000 if X86_32
1969 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001970 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001971 This value puts the alignment restrictions on physical address
1972 where kernel is loaded and run from. Kernel is compiled for an
1973 address which meets above alignment restriction.
1974
1975 If bootloader loads the kernel at a non-aligned address and
1976 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1977 address aligned to above value and run from there.
1978
1979 If bootloader loads the kernel at a non-aligned address and
1980 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1981 load address and decompress itself to the address it has been
1982 compiled for and run from there. The address for which kernel is
1983 compiled already meets above alignment restrictions. Hence the
1984 end result is that kernel runs from a physical address meeting
1985 above alignment restrictions.
1986
Kees Cooka0215062013-07-08 09:15:17 -07001987 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1988 this value must be a multiple of 0x200000.
1989
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001990 Don't change this unless you know what you are doing.
1991
1992config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001993 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001994 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001995 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001996 Say Y here to allow turning CPUs off and on. CPUs can be
1997 controlled through /sys/devices/system/cpu.
1998 ( Note: power management support will enable this option
1999 automatically on SMP systems. )
2000 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002001
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002002config BOOTPARAM_HOTPLUG_CPU0
2003 bool "Set default setting of cpu0_hotpluggable"
2004 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002005 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002006 ---help---
2007 Set whether default state of cpu0_hotpluggable is on or off.
2008
2009 Say Y here to enable CPU0 hotplug by default. If this switch
2010 is turned on, there is no need to give cpu0_hotplug kernel
2011 parameter and the CPU0 hotplug feature is enabled by default.
2012
2013 Please note: there are two known CPU0 dependencies if you want
2014 to enable the CPU0 hotplug feature either by this switch or by
2015 cpu0_hotplug kernel parameter.
2016
2017 First, resume from hibernate or suspend always starts from CPU0.
2018 So hibernate and suspend are prevented if CPU0 is offline.
2019
2020 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2021 offline if any interrupt can not migrate out of CPU0. There may
2022 be other CPU0 dependencies.
2023
2024 Please make sure the dependencies are under your control before
2025 you enable this feature.
2026
2027 Say N if you don't want to enable CPU0 hotplug feature by default.
2028 You still can enable the CPU0 hotplug feature at boot by kernel
2029 parameter cpu0_hotplug.
2030
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002031config DEBUG_HOTPLUG_CPU0
2032 def_bool n
2033 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002034 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002035 ---help---
2036 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2037 soon as possible and boots up userspace with CPU0 offlined. User
2038 can online CPU0 back after boot time.
2039
2040 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2041 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2042 compilation or giving cpu0_hotplug kernel parameter at boot.
2043
2044 If unsure, say N.
2045
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002046config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002047 def_bool n
2048 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002049 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002050 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002051 Certain buggy versions of glibc will crash if they are
2052 presented with a 32-bit vDSO that is not mapped at the address
2053 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002054
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002055 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2056 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2057 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2058 the only released version with the bug, but OpenSUSE 9
2059 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002060
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002061 The symptom of the bug is that everything crashes on startup, saying:
2062 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2063
2064 Saying Y here changes the default value of the vdso32 boot
2065 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2066 This works around the glibc bug but hurts performance.
2067
2068 If unsure, say N: if you are compiling your own kernel, you
2069 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002070
Kees Cook3dc33bd2015-08-12 17:55:19 -07002071choice
2072 prompt "vsyscall table for legacy applications"
2073 depends on X86_64
2074 default LEGACY_VSYSCALL_EMULATE
2075 help
2076 Legacy user code that does not know how to find the vDSO expects
2077 to be able to issue three syscalls by calling fixed addresses in
2078 kernel space. Since this location is not randomized with ASLR,
2079 it can be used to assist security vulnerability exploitation.
2080
2081 This setting can be changed at boot time via the kernel command
2082 line parameter vsyscall=[native|emulate|none].
2083
2084 On a system with recent enough glibc (2.14 or newer) and no
2085 static binaries, you can say None without a performance penalty
2086 to improve security.
2087
2088 If unsure, select "Emulate".
2089
2090 config LEGACY_VSYSCALL_NATIVE
2091 bool "Native"
2092 help
2093 Actual executable code is located in the fixed vsyscall
2094 address mapping, implementing time() efficiently. Since
2095 this makes the mapping executable, it can be used during
2096 security vulnerability exploitation (traditionally as
2097 ROP gadgets). This configuration is not recommended.
2098
2099 config LEGACY_VSYSCALL_EMULATE
2100 bool "Emulate"
2101 help
2102 The kernel traps and emulates calls into the fixed
2103 vsyscall address mapping. This makes the mapping
2104 non-executable, but it still contains known contents,
2105 which could be used in certain rare security vulnerability
2106 exploits. This configuration is recommended when userspace
2107 still uses the vsyscall area.
2108
2109 config LEGACY_VSYSCALL_NONE
2110 bool "None"
2111 help
2112 There will be no vsyscall mapping at all. This will
2113 eliminate any risk of ASLR bypass due to the vsyscall
2114 fixed address mapping. Attempts to use the vsyscalls
2115 will be reported to dmesg, so that either old or
2116 malicious userspace programs can be identified.
2117
2118endchoice
2119
Tim Bird516cbf32008-08-12 12:52:36 -07002120config CMDLINE_BOOL
2121 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002122 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002123 Allow for specifying boot arguments to the kernel at
2124 build time. On some systems (e.g. embedded ones), it is
2125 necessary or convenient to provide some or all of the
2126 kernel boot arguments with the kernel itself (that is,
2127 to not rely on the boot loader to provide them.)
2128
2129 To compile command line arguments into the kernel,
2130 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002131 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002132
2133 Systems with fully functional boot loaders (i.e. non-embedded)
2134 should leave this option set to 'N'.
2135
2136config CMDLINE
2137 string "Built-in kernel command string"
2138 depends on CMDLINE_BOOL
2139 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002140 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002141 Enter arguments here that should be compiled into the kernel
2142 image and used at boot time. If the boot loader provides a
2143 command line at boot time, it is appended to this string to
2144 form the full kernel command line, when the system boots.
2145
2146 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2147 change this behavior.
2148
2149 In most cases, the command line (whether built-in or provided
2150 by the boot loader) should specify the device for the root
2151 file system.
2152
2153config CMDLINE_OVERRIDE
2154 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002155 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002156 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002157 Set this option to 'Y' to have the kernel ignore the boot loader
2158 command line, and use ONLY the built-in command line.
2159
2160 This is used to work around broken boot loaders. This should
2161 be set to 'N' under normal conditions.
2162
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002163config MODIFY_LDT_SYSCALL
2164 bool "Enable the LDT (local descriptor table)" if EXPERT
2165 default y
2166 ---help---
2167 Linux can allow user programs to install a per-process x86
2168 Local Descriptor Table (LDT) using the modify_ldt(2) system
2169 call. This is required to run 16-bit or segmented code such as
2170 DOSEMU or some Wine programs. It is also used by some very old
2171 threading libraries.
2172
2173 Enabling this feature adds a small amount of overhead to
2174 context switches and increases the low-level kernel attack
2175 surface. Disabling it removes the modify_ldt(2) system call.
2176
2177 Saying 'N' here may make sense for embedded or server kernels.
2178
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002179source "kernel/livepatch/Kconfig"
2180
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002181endmenu
2182
2183config ARCH_ENABLE_MEMORY_HOTPLUG
2184 def_bool y
2185 depends on X86_64 || (X86_32 && HIGHMEM)
2186
Gary Hade35551052008-10-31 10:52:03 -07002187config ARCH_ENABLE_MEMORY_HOTREMOVE
2188 def_bool y
2189 depends on MEMORY_HOTPLUG
2190
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002191config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002192 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002193 depends on NUMA
2194
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002195config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2196 def_bool y
2197 depends on X86_64 || X86_PAE
2198
Naoya Horiguchic177c812014-06-04 16:05:35 -07002199config ARCH_ENABLE_HUGEPAGE_MIGRATION
2200 def_bool y
2201 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2202
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002203menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002204
2205config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002206 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002207 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002208
2209source "kernel/power/Kconfig"
2210
2211source "drivers/acpi/Kconfig"
2212
Feng Tangefafc8b2009-08-14 15:23:29 -04002213source "drivers/sfi/Kconfig"
2214
Andi Kleena6b68072008-01-30 13:32:49 +01002215config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002216 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002217 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002218
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002219menuconfig APM
2220 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002221 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002222 ---help---
2223 APM is a BIOS specification for saving power using several different
2224 techniques. This is mostly useful for battery powered laptops with
2225 APM compliant BIOSes. If you say Y here, the system time will be
2226 reset after a RESUME operation, the /proc/apm device will provide
2227 battery status information, and user-space programs will receive
2228 notification of APM "events" (e.g. battery status change).
2229
2230 If you select "Y" here, you can disable actual use of the APM
2231 BIOS by passing the "apm=off" option to the kernel at boot time.
2232
2233 Note that the APM support is almost completely disabled for
2234 machines with more than one CPU.
2235
2236 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002237 and more information, read <file:Documentation/power/apm-acpi.txt>
2238 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002239 <http://www.tldp.org/docs.html#howto>.
2240
2241 This driver does not spin down disk drives (see the hdparm(8)
2242 manpage ("man 8 hdparm") for that), and it doesn't turn off
2243 VESA-compliant "green" monitors.
2244
2245 This driver does not support the TI 4000M TravelMate and the ACER
2246 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2247 desktop machines also don't have compliant BIOSes, and this driver
2248 may cause those machines to panic during the boot phase.
2249
2250 Generally, if you don't have a battery in your machine, there isn't
2251 much point in using this driver and you should say N. If you get
2252 random kernel OOPSes or reboots that don't seem to be related to
2253 anything, try disabling/enabling this option (or disabling/enabling
2254 APM in your BIOS).
2255
2256 Some other things you should try when experiencing seemingly random,
2257 "weird" problems:
2258
2259 1) make sure that you have enough swap space and that it is
2260 enabled.
2261 2) pass the "no-hlt" option to the kernel
2262 3) switch on floating point emulation in the kernel and pass
2263 the "no387" option to the kernel
2264 4) pass the "floppy=nodma" option to the kernel
2265 5) pass the "mem=4M" option to the kernel (thereby disabling
2266 all but the first 4 MB of RAM)
2267 6) make sure that the CPU is not over clocked.
2268 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2269 8) disable the cache from your BIOS settings
2270 9) install a fan for the video card or exchange video RAM
2271 10) install a better fan for the CPU
2272 11) exchange RAM chips
2273 12) exchange the motherboard.
2274
2275 To compile this driver as a module, choose M here: the
2276 module will be called apm.
2277
2278if APM
2279
2280config APM_IGNORE_USER_SUSPEND
2281 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002282 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002283 This option will ignore USER SUSPEND requests. On machines with a
2284 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2285 series notebooks, it is necessary to say Y because of a BIOS bug.
2286
2287config APM_DO_ENABLE
2288 bool "Enable PM at boot time"
2289 ---help---
2290 Enable APM features at boot time. From page 36 of the APM BIOS
2291 specification: "When disabled, the APM BIOS does not automatically
2292 power manage devices, enter the Standby State, enter the Suspend
2293 State, or take power saving steps in response to CPU Idle calls."
2294 This driver will make CPU Idle calls when Linux is idle (unless this
2295 feature is turned off -- see "Do CPU IDLE calls", below). This
2296 should always save battery power, but more complicated APM features
2297 will be dependent on your BIOS implementation. You may need to turn
2298 this option off if your computer hangs at boot time when using APM
2299 support, or if it beeps continuously instead of suspending. Turn
2300 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2301 T400CDT. This is off by default since most machines do fine without
2302 this feature.
2303
2304config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002305 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002306 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002307 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002308 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2309 On some machines, this can activate improved power savings, such as
2310 a slowed CPU clock rate, when the machine is idle. These idle calls
2311 are made after the idle loop has run for some length of time (e.g.,
2312 333 mS). On some machines, this will cause a hang at boot time or
2313 whenever the CPU becomes idle. (On machines with more than one CPU,
2314 this option does nothing.)
2315
2316config APM_DISPLAY_BLANK
2317 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002318 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002319 Enable console blanking using the APM. Some laptops can use this to
2320 turn off the LCD backlight when the screen blanker of the Linux
2321 virtual console blanks the screen. Note that this is only used by
2322 the virtual console screen blanker, and won't turn off the backlight
2323 when using the X Window system. This also doesn't have anything to
2324 do with your VESA-compliant power-saving monitor. Further, this
2325 option doesn't work for all laptops -- it might not turn off your
2326 backlight at all, or it might print a lot of errors to the console,
2327 especially if you are using gpm.
2328
2329config APM_ALLOW_INTS
2330 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002331 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002332 Normally we disable external interrupts while we are making calls to
2333 the APM BIOS as a measure to lessen the effects of a badly behaving
2334 BIOS implementation. The BIOS should reenable interrupts if it
2335 needs to. Unfortunately, some BIOSes do not -- especially those in
2336 many of the newer IBM Thinkpads. If you experience hangs when you
2337 suspend, try setting this to Y. Otherwise, say N.
2338
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002339endif # APM
2340
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002341source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002342
2343source "drivers/cpuidle/Kconfig"
2344
Andy Henroid27471fd2008-10-09 11:45:22 -07002345source "drivers/idle/Kconfig"
2346
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002347endmenu
2348
2349
2350menu "Bus options (PCI etc.)"
2351
2352config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002353 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002354 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002355 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002356 Find out whether you have a PCI motherboard. PCI is the name of a
2357 bus system, i.e. the way the CPU talks to the other stuff inside
2358 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2359 VESA. If you have PCI, say Y, otherwise N.
2360
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002361choice
2362 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002363 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002364 default PCI_GOANY
2365 ---help---
2366 On PCI systems, the BIOS can be used to detect the PCI devices and
2367 determine their configuration. However, some old PCI motherboards
2368 have BIOS bugs and may crash if this is done. Also, some embedded
2369 PCI-based systems don't have any BIOS at all. Linux can also try to
2370 detect the PCI hardware directly without using the BIOS.
2371
2372 With this option, you can specify how Linux should detect the
2373 PCI devices. If you choose "BIOS", the BIOS will be used,
2374 if you choose "Direct", the BIOS won't be used, and if you
2375 choose "MMConfig", then PCI Express MMCONFIG will be used.
2376 If you choose "Any", the kernel will try MMCONFIG, then the
2377 direct access method and falls back to the BIOS if that doesn't
2378 work. If unsure, go with the default, which is "Any".
2379
2380config PCI_GOBIOS
2381 bool "BIOS"
2382
2383config PCI_GOMMCONFIG
2384 bool "MMConfig"
2385
2386config PCI_GODIRECT
2387 bool "Direct"
2388
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002389config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002390 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002391 depends on OLPC
2392
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002393config PCI_GOANY
2394 bool "Any"
2395
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002396endchoice
2397
2398config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002399 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002400 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002401
2402# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2403config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002404 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002405 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002406
2407config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002408 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002409 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002410
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002411config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002412 def_bool y
2413 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002414
Alex Nixonb5401a92010-03-18 16:31:34 -04002415config PCI_XEN
2416 def_bool y
2417 depends on PCI && XEN
2418 select SWIOTLB_XEN
2419
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002420config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002421 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002422 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002423
2424config PCI_MMCONFIG
2425 bool "Support mmconfig PCI config space access"
2426 depends on X86_64 && PCI && ACPI
2427
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002428config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002429 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002430 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002431 help
2432 Read the PCI windows out of the CNB20LE host bridge. This allows
2433 PCI hotplug to work on systems with the CNB20LE chipset which do
2434 not have ACPI.
2435
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002436 There's no public spec for this chipset, and this functionality
2437 is known to be incomplete.
2438
2439 You should say N unless you know you need this.
2440
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002441source "drivers/pci/Kconfig"
2442
David Rientjes1c00f012011-03-22 16:34:59 -07002443# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002444config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002445 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2446 default y
2447 help
2448 Enables ISA-style DMA support for devices requiring such controllers.
2449 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002450
Linus Torvalds51e68d02016-05-21 10:25:19 -07002451if X86_32
2452
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002453config ISA
2454 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002455 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002456 Find out whether you have ISA slots on your motherboard. ISA is the
2457 name of a bus system, i.e. the way the CPU talks to the other stuff
2458 inside your box. Other bus systems are PCI, EISA, MicroChannel
2459 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2460 newer boards don't support it. If you have ISA, say Y, otherwise N.
2461
2462config EISA
2463 bool "EISA support"
2464 depends on ISA
2465 ---help---
2466 The Extended Industry Standard Architecture (EISA) bus was
2467 developed as an open alternative to the IBM MicroChannel bus.
2468
2469 The EISA bus provided some of the features of the IBM MicroChannel
2470 bus while maintaining backward compatibility with cards made for
2471 the older ISA bus. The EISA bus saw limited use between 1988 and
2472 1995 when it was made obsolete by the PCI bus.
2473
2474 Say Y here if you are building a kernel for an EISA-based machine.
2475
2476 Otherwise, say N.
2477
2478source "drivers/eisa/Kconfig"
2479
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002480config SCx200
2481 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002482 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002483 This provides basic support for National Semiconductor's
2484 (now AMD's) Geode processors. The driver probes for the
2485 PCI-IDs of several on-chip devices, so its a good dependency
2486 for other scx200_* drivers.
2487
2488 If compiled as a module, the driver is named scx200.
2489
2490config SCx200HR_TIMER
2491 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002492 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002494 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002495 This driver provides a clocksource built upon the on-chip
2496 27MHz high-resolution timer. Its also a workaround for
2497 NSC Geode SC-1100's buggy TSC, which loses time when the
2498 processor goes idle (as is done by the scheduler). The
2499 other workaround is idle=poll boot option.
2500
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002501config OLPC
2502 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002503 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002504 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002505 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002506 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002507 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002508 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002509 Add support for detecting the unique features of the OLPC
2510 XO hardware.
2511
Daniel Drakea3128582011-06-25 17:34:10 +01002512config OLPC_XO1_PM
2513 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002514 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002515 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002516 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002517 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002518
Daniel Drakecfee9592011-06-25 17:34:17 +01002519config OLPC_XO1_RTC
2520 bool "OLPC XO-1 Real Time Clock"
2521 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2522 ---help---
2523 Add support for the XO-1 real time clock, which can be used as a
2524 programmable wakeup source.
2525
Daniel Drake7feda8e2011-06-25 17:34:12 +01002526config OLPC_XO1_SCI
2527 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002528 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002529 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002530 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002531 select GPIO_CS5535
2532 select MFD_CORE
2533 ---help---
2534 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002535 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002536 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002537 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002538 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002539 - AC adapter status updates
2540 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002541
Daniel Drakea0f30f52011-06-25 17:34:18 +01002542config OLPC_XO15_SCI
2543 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002544 depends on OLPC && ACPI
2545 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002546 ---help---
2547 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2548 - EC-driven system wakeups
2549 - AC adapter status updates
2550 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002551
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002552config ALIX
2553 bool "PCEngines ALIX System Support (LED setup)"
2554 select GPIOLIB
2555 ---help---
2556 This option enables system support for the PCEngines ALIX.
2557 At present this just sets up LEDs for GPIO control on
2558 ALIX2/3/6 boards. However, other system specific setup should
2559 get added here.
2560
2561 Note: You must still enable the drivers for GPIO and LED support
2562 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2563
2564 Note: You have to set alix.force=1 for boards with Award BIOS.
2565
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002566config NET5501
2567 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2568 select GPIOLIB
2569 ---help---
2570 This option enables system support for the Soekris Engineering net5501.
2571
Philip A. Prindeville31970592012-01-14 01:45:39 -07002572config GEOS
2573 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2574 select GPIOLIB
2575 depends on DMI
2576 ---help---
2577 This option enables system support for the Traverse Technologies GEOS.
2578
Vivien Didelot7d029122013-01-04 16:18:14 -05002579config TS5500
2580 bool "Technologic Systems TS-5500 platform support"
2581 depends on MELAN
2582 select CHECK_SIGNATURE
2583 select NEW_LEDS
2584 select LEDS_CLASS
2585 ---help---
2586 This option enables system support for the Technologic Systems TS-5500.
2587
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002588endif # X86_32
2589
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002590config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002591 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002592 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002593
2594source "drivers/pcmcia/Kconfig"
2595
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002596config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002597 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002598 depends on PCI
2599 default n
2600 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002601 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002602 infrastructure code to support RapidIO interconnect devices.
2603
2604source "drivers/rapidio/Kconfig"
2605
David Herrmanne3263ab2013-08-02 14:05:22 +02002606config X86_SYSFB
2607 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2608 help
2609 Firmwares often provide initial graphics framebuffers so the BIOS,
2610 bootloader or kernel can show basic video-output during boot for
2611 user-guidance and debugging. Historically, x86 used the VESA BIOS
2612 Extensions and EFI-framebuffers for this, which are mostly limited
2613 to x86.
2614 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2615 framebuffers so the new generic system-framebuffer drivers can be
2616 used on x86. If the framebuffer is not compatible with the generic
2617 modes, it is adverticed as fallback platform framebuffer so legacy
2618 drivers like efifb, vesafb and uvesafb can pick it up.
2619 If this option is not selected, all system framebuffers are always
2620 marked as fallback platform framebuffers as usual.
2621
2622 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2623 not be able to pick up generic system framebuffers if this option
2624 is selected. You are highly encouraged to enable simplefb as
2625 replacement if you select this option. simplefb can correctly deal
2626 with generic system framebuffers. But you should still keep vesafb
2627 and others enabled as fallback if a system framebuffer is
2628 incompatible with simplefb.
2629
2630 If unsure, say Y.
2631
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002632endmenu
2633
2634
2635menu "Executable file formats / Emulations"
2636
2637source "fs/Kconfig.binfmt"
2638
2639config IA32_EMULATION
2640 bool "IA32 Emulation"
2641 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002642 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002643 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002644 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002645 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002646 Include code to run legacy 32-bit programs under a
2647 64-bit kernel. You should likely turn this on, unless you're
2648 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002649
2650config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002651 tristate "IA32 a.out support"
2652 depends on IA32_EMULATION
2653 ---help---
2654 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002655
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002656config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002657 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002658 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002659 ---help---
2660 Include code to run binaries for the x32 native 32-bit ABI
2661 for 64-bit processors. An x32 process gets access to the
2662 full 64-bit register file and wide data path while leaving
2663 pointers at 32 bits for smaller memory footprint.
2664
2665 You will need a recent binutils (2.22 or later) with
2666 elf32_x86_64 support enabled to compile a kernel with this
2667 option set.
2668
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002669config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002670 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002671 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002672
Jan Beulich3120e252012-09-10 12:41:45 +01002673if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002674config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002675 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002676
2677config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002678 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002679 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002680
David Howellsee009e4a02011-03-07 15:06:20 +00002681config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002682 def_bool y
2683 depends on KEYS
2684endif
David Howellsee009e4a02011-03-07 15:06:20 +00002685
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002686endmenu
2687
2688
Keith Packarde5beae12008-11-03 18:21:45 +01002689config HAVE_ATOMIC_IOMAP
2690 def_bool y
2691 depends on X86_32
2692
Alessandro Rubini4692d772012-04-04 19:39:58 +02002693config X86_DEV_DMA_OPS
2694 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002695 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002696
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002697config X86_DMA_REMAP
2698 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002699 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002700
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002701config PMC_ATOM
2702 def_bool y
2703 depends on PCI
2704
Keith Busch185a3832016-01-12 13:18:10 -07002705config VMD
2706 depends on PCI_MSI
2707 tristate "Volume Management Device Driver"
2708 default N
2709 ---help---
2710 Adds support for the Intel Volume Management Device (VMD). VMD is a
2711 secondary PCI host bridge that allows PCI Express root ports,
2712 and devices attached to them, to be removed from the default
2713 PCI domain and placed within the VMD domain. This provides
2714 more bus resources than are otherwise possible with a
2715 single domain. If you know your system provides one of these and
2716 has devices attached to it, say Y; if you are not sure, say N.
2717
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002718source "net/Kconfig"
2719
2720source "drivers/Kconfig"
2721
2722source "drivers/firmware/Kconfig"
2723
2724source "fs/Kconfig"
2725
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726source "arch/x86/Kconfig.debug"
2727
2728source "security/Kconfig"
2729
2730source "crypto/Kconfig"
2731
Avi Kivityedf88412007-12-16 11:02:48 +02002732source "arch/x86/kvm/Kconfig"
2733
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002734source "lib/Kconfig"