blob: 9640942b68b912911d618c9d357418f717b424c3 [file] [log] [blame]
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
Kees Cook5b710f32016-06-23 15:04:01 -070083 select HAVE_ARCH_HARDENED_USERCOPY
Ingo Molnar6471b822015-06-03 10:00:13 +020084 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
85 select HAVE_ARCH_JUMP_LABEL
86 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
87 select HAVE_ARCH_KGDB
88 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080089 select HAVE_ARCH_MMAP_RND_BITS if MMU
90 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select HAVE_ARCH_SECCOMP_FILTER
92 select HAVE_ARCH_SOFT_DIRTY if X86_64
93 select HAVE_ARCH_TRACEHOOK
94 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Kees Cook0f60a8e2016-07-12 16:19:48 -070095 select HAVE_ARCH_WITHIN_STACK_FRAMES
Daniel Borkmann60777762016-05-13 19:08:28 +020096 select HAVE_EBPF_JIT if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020097 select HAVE_CC_STACKPROTECTOR
98 select HAVE_CMPXCHG_DOUBLE
99 select HAVE_CMPXCHG_LOCAL
100 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700101 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200102 select HAVE_C_RECORDMCOUNT
103 select HAVE_DEBUG_KMEMLEAK
104 select HAVE_DEBUG_STACKOVERFLOW
105 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700106 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400107 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900108 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700109 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700110 select HAVE_EXIT_THREAD
Ingo Molnar6471b822015-06-03 10:00:13 +0200111 select HAVE_FENTRY if X86_64
112 select HAVE_FTRACE_MCOUNT_RECORD
113 select HAVE_FUNCTION_GRAPH_FP_TEST
114 select HAVE_FUNCTION_GRAPH_TRACER
115 select HAVE_FUNCTION_TRACER
116 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530117 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200118 select HAVE_IDE
119 select HAVE_IOREMAP_PROT
120 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
121 select HAVE_IRQ_TIME_ACCOUNTING
122 select HAVE_KERNEL_BZIP2
123 select HAVE_KERNEL_GZIP
124 select HAVE_KERNEL_LZ4
125 select HAVE_KERNEL_LZMA
126 select HAVE_KERNEL_LZO
127 select HAVE_KERNEL_XZ
128 select HAVE_KPROBES
129 select HAVE_KPROBES_ON_FTRACE
130 select HAVE_KRETPROBES
131 select HAVE_KVM
132 select HAVE_LIVEPATCH if X86_64
133 select HAVE_MEMBLOCK
134 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200135 select HAVE_MIXED_BREAKPOINTS_REGS
Petr Mladek42a0bb32016-05-20 17:00:33 -0700136 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200137 select HAVE_OPROFILE
138 select HAVE_OPTPROBES
139 select HAVE_PCSPKR_PLATFORM
140 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200141 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200142 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200143 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select HAVE_REGS_AND_STACK_ACCESS_API
145 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400146 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200147 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300148 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100149 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200150 select MODULES_USE_ELF_RELA if X86_64
151 select MODULES_USE_ELF_REL if X86_32
152 select OLD_SIGACTION if X86_32
153 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
154 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500155 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200156 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500157 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200158 select SYSCTL_EXCEPTION_TRACE
159 select USER_STACKTRACE_SUPPORT
160 select VIRT_TO_BUS
161 select X86_DEV_DMA_OPS if X86_64
162 select X86_FEATURE_NAMES if PROC_FS
Josh Poimboeufd4883d52016-02-28 22:22:43 -0600163 select HAVE_STACK_VALIDATION if X86_64
Dave Hansen63c17fb2016-02-12 13:02:08 -0800164 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen66d37572016-02-12 13:02:32 -0800165 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530166
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200167config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100168 def_bool y
169 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200170
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700171config OUTPUT_FORMAT
172 string
173 default "elf32-i386" if X86_32
174 default "elf64-x86-64" if X86_64
175
Sam Ravnborg73531902008-05-25 23:03:18 +0200176config ARCH_DEFCONFIG
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200177 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200178 default "arch/x86/configs/i386_defconfig" if X86_32
179 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bfb2008-04-29 12:48:15 +0200180
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100181config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100182 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100183
184config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100185 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100186
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100187config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100188 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100189
Daniel Cashman9e08f572016-01-14 15:20:06 -0800190config ARCH_MMAP_RND_BITS_MIN
191 default 28 if 64BIT
192 default 8
193
194config ARCH_MMAP_RND_BITS_MAX
195 default 32 if 64BIT
196 default 16
197
198config ARCH_MMAP_RND_COMPAT_BITS_MIN
199 default 8
200
201config ARCH_MMAP_RND_COMPAT_BITS_MAX
202 default 16
203
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100204config SBUS
205 bool
206
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800207config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100208 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400209 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800210
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700211config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700212 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700213
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100214config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100215 def_bool y
216 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100217
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100218config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100219 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100220 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000221 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
222
223config GENERIC_BUG_RELATIVE_POINTERS
224 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100225
226config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100227 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100228
229config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100230 def_bool y
231 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100232
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100233config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100234 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100235
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100236config GENERIC_CALIBRATE_DELAY
237 def_bool y
238
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800239config ARCH_HAS_CPU_RELAX
240 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100241
Pekka Enberg1b27d052008-04-28 02:12:22 -0700242config ARCH_HAS_CACHE_LINE_SIZE
243 def_bool y
244
Mike Travisdd5af902008-01-30 13:33:32 +0100245config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900246 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100247
Tejun Heo08fc4582009-08-14 15:00:49 +0900248config NEED_PER_CPU_EMBED_FIRST_CHUNK
249 def_bool y
250
251config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900252 def_bool y
253
Johannes Berg801e4062007-12-08 02:12:39 +0100254config ARCH_HIBERNATION_POSSIBLE
255 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100256
Johannes Bergf4cb5702007-12-08 02:14:00 +0100257config ARCH_SUSPEND_POSSIBLE
258 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100259
Steve Cappercfe28c52013-04-29 14:29:48 +0100260config ARCH_WANT_HUGE_PMD_SHARE
261 def_bool y
262
Steve Capper53313b22013-04-30 08:03:42 +0100263config ARCH_WANT_GENERAL_HUGETLB
264 def_bool y
265
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100266config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000267 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100268
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100269config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000270 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100271
Ingo Molnar765c68b2008-04-09 11:03:37 +0200272config ARCH_SUPPORTS_OPTIMIZED_INLINING
273 def_bool y
274
Akinobu Mita6a11f752009-03-31 15:23:17 -0700275config ARCH_SUPPORTS_DEBUG_PAGEALLOC
276 def_bool y
277
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300278config KASAN_SHADOW_OFFSET
279 hex
280 depends on KASAN
281 default 0xdffffc0000000000
282
Shane Wang69575d32009-09-01 18:25:07 -0700283config HAVE_INTEL_TXT
284 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700285 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700286
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100287config X86_32_SMP
288 def_bool y
289 depends on X86_32 && SMP
290
291config X86_64_SMP
292 def_bool y
293 depends on X86_64 && SMP
294
Tejun Heoccbeed32009-02-09 22:17:40 +0900295config X86_32_LAZY_GS
296 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900297 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900298
Borislav Petkovd61931d2010-03-05 17:34:46 +0100299config ARCH_HWEIGHT_CFLAGS
300 string
301 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
302 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
303
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530304config ARCH_SUPPORTS_UPROBES
305 def_bool y
306
Rob Herringd20642f2014-04-18 17:19:54 -0500307config FIX_EARLYCON_MEM
308 def_bool y
309
Kees Cook9ccaf772016-02-17 14:41:14 -0800310config DEBUG_RODATA
311 def_bool y
312
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700313config PGTABLE_LEVELS
314 int
315 default 4 if X86_64
316 default 3 if X86_PAE
317 default 2
318
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100319source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700320source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100322menu "Processor type and features"
323
Randy Dunlap5ee71532012-01-16 11:57:18 -0800324config ZONE_DMA
325 bool "DMA memory allocation support" if EXPERT
326 default y
327 help
328 DMA memory allocation support allows devices with less than 32-bit
329 addressing to allocate within the first 16MB of address space.
330 Disable if no such devices will be used.
331
332 If unsure, say Y.
333
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100334config SMP
335 bool "Symmetric multi-processing support"
336 ---help---
337 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800338 a system with only one CPU, say N. If you have a system with more
339 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100340
Robert Graffham4a474152014-01-23 15:55:29 -0800341 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100342 machines, but will use only one CPU of a multiprocessor machine. If
343 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800344 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100345 will run faster if you say N here.
346
347 Note that if you say Y here and choose architecture "586" or
348 "Pentium" under "Processor family", the kernel will not work on 486
349 architectures. Similarly, multiprocessor kernels for the "PPro"
350 architecture may not work on all Pentium based boards.
351
352 People using multiprocessor machines who say Y here should also say
353 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
354 Management" code will be disabled if you say Y here.
355
Paul Bolle395cf962011-08-15 02:02:26 +0200356 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100357 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
358 <http://www.tldp.org/docs.html#howto>.
359
360 If you don't know what to do here, say N.
361
Josh Triplett9def39be2013-10-30 08:09:45 -0700362config X86_FEATURE_NAMES
363 bool "Processor feature human-readable names" if EMBEDDED
364 default y
365 ---help---
366 This option compiles in a table of x86 feature bits and corresponding
367 names. This is required to support /proc/cpuinfo and a few kernel
368 messages. You can disable this to save space, at the expense of
369 making those few kernel messages show numeric feature bits instead.
370
371 If in doubt, say Y.
372
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100373config X86_FAST_FEATURE_TESTS
374 bool "Fast CPU feature tests" if EMBEDDED
375 default y
376 ---help---
377 Some fast-paths in the kernel depend on the capabilities of the CPU.
378 Say Y here for the kernel to patch in the appropriate code at runtime
379 based on the capabilities of the CPU. The infrastructure for patching
380 code at runtime takes up some additional space; space-constrained
381 embedded systems may wish to say N here to produce smaller, slightly
382 slower code.
383
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800384config X86_X2APIC
385 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200386 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800387 ---help---
388 This enables x2apic support on CPUs that have this feature.
389
390 This allows 32-bit apic IDs (so it can support very large systems),
391 and accesses the local apic via MSRs not via mmio.
392
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800393 If you don't know what to do here, say N.
394
Yinghai Lu6695c852008-06-19 12:13:09 -0700395config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700396 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000397 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200398 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100399 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700400 For old smp systems that do not have proper acpi support. Newer systems
401 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700402
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800403config X86_BIGSMP
404 bool "Support for big SMP systems with more than 8 CPUs"
405 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100406 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800407 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100408
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000409config GOLDFISH
410 def_bool y
411 depends on X86_GOLDFISH
412
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800413if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800414config X86_EXTENDED_PLATFORM
415 bool "Support for extended (non-PC) x86 platforms"
416 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100417 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100418 If you disable this option then the kernel will only support
419 standard PC platforms. (which covers the vast majority of
420 systems out there.)
421
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800422 If you enable this option then you'll be able to select support
423 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100424 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800425 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800426 RDC R-321x SoC
427 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200428 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200429 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100430
431 If you have one of these systems, or if you want to build a
432 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800433endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100434
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800435if X86_64
436config X86_EXTENDED_PLATFORM
437 bool "Support for extended (non-PC) x86 platforms"
438 default y
439 ---help---
440 If you disable this option then the kernel will only support
441 standard PC platforms. (which covers the vast majority of
442 systems out there.)
443
444 If you enable this option then you'll be able to select support
445 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800446 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800447 ScaleMP vSMP
448 SGI Ultraviolet
449
450 If you have one of these systems, or if you want to build a
451 generic distribution kernel, say Y here - otherwise say N.
452endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800453# This is an alphabetically sorted list of 64 bit extended platforms
454# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800455config X86_NUMACHIP
456 bool "Numascale NumaChip"
457 depends on X86_64
458 depends on X86_EXTENDED_PLATFORM
459 depends on NUMA
460 depends on SMP
461 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700462 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800463 ---help---
464 Adds support for Numascale NumaChip large-SMP systems. Needed to
465 enable more than ~168 cores.
466 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100467
Ingo Molnar6a485652009-01-27 18:29:13 +0100468config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800469 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100470 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100471 select PARAVIRT
472 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800473 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300474 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100475 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100476 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
477 supposed to run on these EM64T-based machines. Only choose this option
478 if you have one of these machines.
479
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800480config X86_UV
481 bool "SGI Ultraviolet"
482 depends on X86_64
483 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500484 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800485 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700486 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200487 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800488 ---help---
489 This option is needed in order to support SGI Ultraviolet systems.
490 If you don't have one of these, you should say N here.
491
492# Following is an alphabetically sorted list of 32 bit extended platforms
493# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100494
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000495config X86_GOLDFISH
496 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100497 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000498 ---help---
499 Enable support for the Goldfish virtual platform used primarily
500 for Android development. Unless you are building for the Android
501 Goldfish emulator say N here.
502
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800503config X86_INTEL_CE
504 bool "CE4100 TV platform"
505 depends on PCI
506 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800507 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800508 depends on X86_32
509 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800510 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100511 select OF
512 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800513 ---help---
514 Select for the Intel CE media processor (CE4100) SOC.
515 This option compiles in support for the CE4100 SOC for settop
516 boxes and media devices.
517
David Cohen4cb9b002013-12-16 17:37:26 -0800518config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100519 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100520 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800521 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000522 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200523 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000524 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000525 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800526 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000527 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000528 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000529 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000530 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000531 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800532 Select to build a kernel capable of supporting Intel MID (Mobile
533 Internet Device) platform systems which do not have the PCI legacy
534 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000535
David Cohen4cb9b002013-12-16 17:37:26 -0800536 Intel MID platforms are based on an Intel processor and chipset which
537 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100538
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000539config X86_INTEL_QUARK
540 bool "Intel Quark platform support"
541 depends on X86_32
542 depends on X86_EXTENDED_PLATFORM
543 depends on X86_PLATFORM_DEVICES
544 depends on X86_TSC
545 depends on PCI
546 depends on PCI_GOANY
547 depends on X86_IO_APIC
548 select IOSF_MBI
549 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200550 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000551 ---help---
552 Select to include support for Quark X1000 SoC.
553 Say Y here if you have a Quark based system such as the Arduino
554 compatible Intel Galileo.
555
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000556config X86_INTEL_LPSS
557 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100558 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000559 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300560 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100561 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000562 ---help---
563 Select to build support for Intel Low Power Subsystem such as
564 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300565 things like clock tree (common clock framework) and pincontrol
566 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000567
Ken Xue92082a82015-02-06 08:27:51 +0800568config X86_AMD_PLATFORM_DEVICE
569 bool "AMD ACPI2Platform devices support"
570 depends on ACPI
571 select COMMON_CLK
572 select PINCTRL
573 ---help---
574 Select to interpret AMD specific ACPI device to platform device
575 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
576 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
577 implemented under PINCTRL subsystem.
578
David E. Boxced3ce72014-09-17 22:13:50 -0700579config IOSF_MBI
580 tristate "Intel SoC IOSF Sideband support for SoC platforms"
581 depends on PCI
582 ---help---
583 This option enables sideband register access support for Intel SoC
584 platforms. On these platforms the IOSF sideband is used in lieu of
585 MSR's for some register accesses, mostly but not limited to thermal
586 and power. Drivers may query the availability of this device to
587 determine if they need the sideband in order to work on these
588 platforms. The sideband is available on the following SoC products.
589 This list is not meant to be exclusive.
590 - BayTrail
591 - Braswell
592 - Quark
593
594 You should say Y if you are running a kernel on one of these SoC's.
595
David E. Boxed2226b2014-09-17 22:13:51 -0700596config IOSF_MBI_DEBUG
597 bool "Enable IOSF sideband access through debugfs"
598 depends on IOSF_MBI && DEBUG_FS
599 ---help---
600 Select this option to expose the IOSF sideband access registers (MCR,
601 MDR, MCRX) through debugfs to write and read register information from
602 different units on the SoC. This is most useful for obtaining device
603 state information for debug and analysis. As this is a general access
604 mechanism, users of this option would have specific knowledge of the
605 device they want to access.
606
607 If you don't require the option or are in doubt, say N.
608
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800609config X86_RDC321X
610 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100611 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800612 depends on X86_EXTENDED_PLATFORM
613 select M486
614 select X86_REBOOTFIXUPS
615 ---help---
616 This option is needed for RDC R-321x system-on-chip, also known
617 as R-8610-(G).
618 If you don't have one of these chips, you should say N here.
619
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100620config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100621 bool "Support non-standard 32-bit SMP architectures"
622 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800623 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100624 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800625 This option compiles in the bigsmp and STA2X11 default
626 subarchitectures. It is intended for a generic binary
627 kernel. If you select them all, kernel will probe it one by
628 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700629
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800630# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700631
Linus Torvaldsd949f362009-09-26 09:35:07 -0700632config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100633 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700634 # MCE code calls memory_failure():
635 depends on X86_MCE
636 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700637 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
638 depends on X86_64 || !SPARSEMEM
639 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700640
Alessandro Rubini83125a32012-04-04 19:40:21 +0200641config STA2X11
642 bool "STA2X11 Companion Chip Support"
643 depends on X86_32_NON_STANDARD && PCI
644 select X86_DEV_DMA_OPS
645 select X86_DMA_REMAP
646 select SWIOTLB
647 select MFD_STA2X11
648 select ARCH_REQUIRE_GPIOLIB
649 default n
650 ---help---
651 This adds support for boards based on the STA2X11 IO-Hub,
652 a.k.a. "ConneXt". The chip is used in place of the standard
653 PC chipset, so all "standard" peripherals are missing. If this
654 option is selected the kernel will still be able to boot on
655 standard PC machines.
656
Shérab82148d12010-09-25 06:06:57 +0200657config X86_32_IRIS
658 tristate "Eurobraille/Iris poweroff module"
659 depends on X86_32
660 ---help---
661 The Iris machines from EuroBraille do not have APM or ACPI support
662 to shut themselves down properly. A special I/O sequence is
663 needed to do so, which is what this module does at
664 kernel shutdown.
665
666 This is only for Iris machines from EuroBraille.
667
668 If unused, say N.
669
Ingo Molnarae1e9132008-11-11 09:05:16 +0100670config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100671 def_bool y
672 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800673 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100674 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100675 Calculate simpler /proc/<PID>/wchan values. If this option
676 is disabled then wchan values will recurse back to the
677 caller function. This provides more accurate wchan values,
678 at the expense of slightly more scheduling overhead.
679
680 If in doubt, say "Y".
681
Borislav Petkov6276a072013-03-04 21:20:21 +0100682menuconfig HYPERVISOR_GUEST
683 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100684 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100685 Say Y here to enable options for running Linux under various hyper-
686 visors. This option enables basic hypervisor detection and platform
687 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100688
Borislav Petkov6276a072013-03-04 21:20:21 +0100689 If you say N, all options in this submenu will be skipped and
690 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100691
Borislav Petkov6276a072013-03-04 21:20:21 +0100692if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100693
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100694config PARAVIRT
695 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100696 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100697 This changes the kernel so it can modify itself when it is run
698 under a hypervisor, potentially improving performance significantly
699 over full virtualization. However, when run without a hypervisor
700 the kernel is theoretically slower and slightly larger.
701
Borislav Petkov6276a072013-03-04 21:20:21 +0100702config PARAVIRT_DEBUG
703 bool "paravirt-ops debugging"
704 depends on PARAVIRT && DEBUG_KERNEL
705 ---help---
706 Enable to debug paravirt_ops internals. Specifically, BUG if
707 a paravirt_op is missing when it is called.
708
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700709config PARAVIRT_SPINLOCKS
710 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700711 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200712 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700713 ---help---
714 Paravirtualized spinlocks allow a pvops backend to replace the
715 spinlock implementation with something virtualization-friendly
716 (for example, block the virtual CPU rather than spinning).
717
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530718 It has a minimal impact on native kernels and gives a nice performance
719 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700720
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530721 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700722
Waiman Long45e898b2015-11-09 19:09:25 -0500723config QUEUED_LOCK_STAT
724 bool "Paravirt queued spinlock statistics"
725 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
726 ---help---
727 Enable the collection of statistical data on the slowpath
728 behavior of paravirtualized queued spinlocks and report
729 them on debugfs.
730
Borislav Petkov6276a072013-03-04 21:20:21 +0100731source "arch/x86/xen/Kconfig"
732
733config KVM_GUEST
734 bool "KVM Guest support (including kvmclock)"
735 depends on PARAVIRT
736 select PARAVIRT_CLOCK
737 default y
738 ---help---
739 This option enables various optimizations for running under the KVM
740 hypervisor. It includes a paravirtualized clock, so that instead
741 of relying on a PIT (or probably other) emulation by the
742 underlying device model, the host provides the guest with
743 timing infrastructure such as time of day, and system time
744
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530745config KVM_DEBUG_FS
746 bool "Enable debug information for KVM Guests in debugfs"
747 depends on KVM_GUEST && DEBUG_FS
748 default n
749 ---help---
750 This option enables collection of various statistics for KVM guest.
751 Statistics are displayed in debugfs filesystem. Enabling this option
752 may incur significant overhead.
753
Borislav Petkov6276a072013-03-04 21:20:21 +0100754source "arch/x86/lguest/Kconfig"
755
756config PARAVIRT_TIME_ACCOUNTING
757 bool "Paravirtual steal time accounting"
758 depends on PARAVIRT
759 default n
760 ---help---
761 Select this option to enable fine granularity task steal time
762 accounting. Time spent executing other tasks in parallel with
763 the current vCPU is discounted from the vCPU power. To account for
764 that, there can be a small performance impact.
765
766 If in doubt, say N here.
767
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200768config PARAVIRT_CLOCK
769 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200770
Borislav Petkov6276a072013-03-04 21:20:21 +0100771endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400772
Yinghai Lu08677212010-02-10 01:20:20 -0800773config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700774 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800775
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100776source "arch/x86/Kconfig.cpu"
777
778config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100779 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100780 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100781 ---help---
782 Use the IA-PC HPET (High Precision Event Timer) to manage
783 time in preference to the PIT and RTC, if a HPET is
784 present.
785 HPET is the next generation timer replacing legacy 8254s.
786 The HPET provides a stable time base on SMP
787 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200788 as it is off-chip. The interface used is documented
789 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100790
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100791 You can safely choose Y here. However, HPET will only be
792 activated if the platform and the BIOS support this feature.
793 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100794
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100795 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100796
797config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100798 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800799 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100800
Jacob Panbb24c472009-09-02 07:37:17 -0700801config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000802 def_bool y if X86_INTEL_MID
803 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100804 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000805 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700806 help
807 APB timer is the replacement for 8254, HPET on X86 MID platforms.
808 The APBT provides a stable time base on SMP
809 systems, unlike the TSC, but it is more expensive to access,
810 as it is off-chip. APB timers are always running regardless of CPU
811 C states, they are used as per CPU clockevent device when possible.
812
David Rientjes6a108a12011-01-20 14:44:16 -0800813# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100814# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700815config DMI
816 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800817 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800818 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100819 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700820 Enabled scanning of DMI to identify machine quirks. Say Y
821 here unless you have verified that your setup is not
822 affected by entries in the DMI blacklist. Required by PNP
823 BIOS code.
824
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100825config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700826 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100827 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200828 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100829 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200830 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
831 GART based hardware IOMMUs.
832
833 The GART supports full DMA access for devices with 32-bit access
834 limitations, on systems with more than 3 GB. This is usually needed
835 for USB, sound, many IDE/SATA chipsets and some other devices.
836
837 Newer systems typically have a modern AMD IOMMU, supported via
838 the CONFIG_AMD_IOMMU=y config option.
839
840 In normal configurations this driver is only active when needed:
841 there's more than 3 GB of memory and the system contains a
842 32-bit limited device.
843
844 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100845
846config CALGARY_IOMMU
847 bool "IBM Calgary IOMMU support"
848 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700849 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100850 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100851 Support for hardware IOMMUs in IBM's xSeries x366 and x460
852 systems. Needed to run systems with more than 3GB of memory
853 properly with 32-bit PCI devices that do not support DAC
854 (Double Address Cycle). Calgary also supports bus level
855 isolation, where all DMAs pass through the IOMMU. This
856 prevents them from going anywhere except their intended
857 destination. This catches hard-to-find kernel bugs and
858 mis-behaving drivers and devices that do not use the DMA-API
859 properly to set up their DMA buffers. The IOMMU can be
860 turned off at boot time with the iommu=off parameter.
861 Normally the kernel will make the right choice by itself.
862 If unsure, say Y.
863
864config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100865 def_bool y
866 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100867 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100868 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100869 Should Calgary be enabled by default? if you choose 'y', Calgary
870 will be used (if it exists). If you choose 'n', Calgary will not be
871 used even if it exists. If you choose 'n' and would like to use
872 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
873 If unsure, say Y.
874
875# need this always selected by IOMMU for the VIA workaround
876config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100877 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100878 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100879 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700880 which don't have a hardware IOMMU. Using this PCI devices
881 which can only access 32-bits of memory can be used on systems
882 with more than 3 GB of memory.
883 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100884
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700885config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100886 def_bool y
887 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700888
Mike Travis1184dc22008-05-12 21:21:12 +0200889config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200890 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700891 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800892 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100893 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200894 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200895 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100896
897config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800898 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400899 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500900 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500901 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800902 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500903 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800904 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300905 default "8" if SMP && X86_32
906 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100907 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100908 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500909 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300910 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100911 minimum value which makes sense is 2.
912
913 This is purely to save memory - each supported CPU adds
914 approximately eight kilobytes to the kernel image.
915
916config SCHED_SMT
917 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200918 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100919 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100920 SMT scheduler support improves the CPU scheduler's decision making
921 when dealing with Intel Pentium 4 chips with HyperThreading at a
922 cost of slightly increased overhead in some places. If unsure say
923 N here.
924
925config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100926 def_bool y
927 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200928 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100929 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100930 Multi-core scheduler support improves the CPU scheduler's decision
931 making when dealing with multi-core CPU chips at a cost of slightly
932 increased overhead in some places. If unsure say N here.
933
934source "kernel/Kconfig.preempt"
935
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000936config UP_LATE_INIT
937 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100938 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000939
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100940config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000941 bool "Local APIC support on uniprocessors" if !PCI_MSI
942 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000943 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100944 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100945 A local APIC (Advanced Programmable Interrupt Controller) is an
946 integrated interrupt controller in the CPU. If you have a single-CPU
947 system which has a processor with a local APIC, you can say Y here to
948 enable and use it. If you say Y here even though your machine doesn't
949 have a local APIC, then the kernel will still run with no slowdown at
950 all. The local APIC supports CPU-generated self-interrupts (timer,
951 performance counters), and the NMI watchdog which detects hard
952 lockups.
953
954config X86_UP_IOAPIC
955 bool "IO-APIC support on uniprocessors"
956 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100957 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100958 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
959 SMP-capable replacement for PC-style interrupt controllers. Most
960 SMP systems and many recent uniprocessor systems have one.
961
962 If you have a single-CPU system with an IO-APIC, you can say Y here
963 to use it. If you say Y here even though your machine doesn't have
964 an IO-APIC, then the kernel will still run with no slowdown at all.
965
966config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100967 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200968 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800969 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800970 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100971
972config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000973 def_bool y
974 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100975
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200976config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
977 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200978 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100979 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200980 This option enables a workaround that fixes a source of
981 spurious interrupts. This is recommended when threaded
982 interrupt handling is used on systems where the generation of
983 superfluous "boot interrupts" cannot be disabled.
984
985 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
986 entry in the chipset's IO-APIC is masked (as, e.g. the RT
987 kernel does during interrupt handling). On chipsets where this
988 boot IRQ generation cannot be disabled, this workaround keeps
989 the original IRQ line masked so that only the equivalent "boot
990 IRQ" is delivered to the CPUs. The workaround also tells the
991 kernel to set up the IRQ handler on the boot IRQ line. In this
992 way only one interrupt is delivered to the kernel. Otherwise
993 the spurious second interrupt may cause the kernel to bring
994 down (vital) interrupt lines.
995
996 Only affects "broken" chipsets. Interrupt sharing may be
997 increased on these systems.
998
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100999config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001000 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001001 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001002 default y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001003 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001004 Machine Check support allows the processor to notify the
1005 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001006 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001007 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001008
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001009config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001010 def_bool y
1011 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001012 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001013 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001014 Additional support for intel specific MCE features such as
1015 the thermal monitor.
1016
1017config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001018 def_bool y
1019 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001020 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001021 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001022 Additional support for AMD specific MCE features such as
1023 the DRAM Error Threshold.
1024
Andi Kleen4efc0672009-04-28 19:07:31 +02001025config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001026 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001027 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001028 ---help---
1029 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001030 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001031 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001032
Andi Kleenb2762682009-02-12 13:49:31 +01001033config X86_MCE_THRESHOLD
1034 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001035 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001036
Andi Kleenea149b32009-04-29 19:31:00 +02001037config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001038 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001039 tristate "Machine check injector support"
1040 ---help---
1041 Provide support for injecting machine checks for testing purposes.
1042 If you don't know what a machine check is and you don't do kernel
1043 QA it is safe to say n.
1044
Andi Kleen4efc0672009-04-28 19:07:31 +02001045config X86_THERMAL_VECTOR
1046 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001047 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001048
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001049source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001050
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001051config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001052 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001053 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001054 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001055 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001056 This option allows user programs to put the CPU into V8086
1057 mode, which is an 80286-era approximation of 16-bit real mode.
1058
1059 Some very old versions of X and/or vbetool require this option
1060 for user mode setting. Similarly, DOSEMU will use it if
1061 available to accelerate real mode DOS programs. However, any
1062 recent version of DOSEMU, X, or vbetool should be fully
1063 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001064 fall back to software emulation. Nevertheless, if you are using
1065 a 16-bit DOS program where 16-bit performance matters, vm86
1066 mode might be faster than emulation and you might want to
1067 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001068
Ingo Molnar1e642812015-09-05 08:58:10 +02001069 Note that any app that works on a 64-bit kernel is unlikely to
1070 need this option, as 64-bit kernels don't, and can't, support
1071 V8086 mode. This option is also unrelated to 16-bit protected
1072 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001073
Ingo Molnar1e642812015-09-05 08:58:10 +02001074 Enabling this option increases the complexity of the kernel
1075 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001076
Ingo Molnar1e642812015-09-05 08:58:10 +02001077 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001078
1079config VM86
1080 bool
1081 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001082
1083config X86_16BIT
1084 bool "Enable support for 16-bit segments" if EXPERT
1085 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001086 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001087 ---help---
1088 This option is required by programs like Wine to run 16-bit
1089 protected mode legacy code on x86 processors. Disabling
1090 this option saves about 300 bytes on i386, or around 6K text
1091 plus 16K runtime memory on x86-64,
1092
1093config X86_ESPFIX32
1094 def_bool y
1095 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001096
H. Peter Anvin197725d2014-05-04 10:00:49 -07001097config X86_ESPFIX64
1098 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001099 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001100
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001101config X86_VSYSCALL_EMULATION
1102 bool "Enable vsyscall emulation" if EXPERT
1103 default y
1104 depends on X86_64
1105 ---help---
1106 This enables emulation of the legacy vsyscall page. Disabling
1107 it is roughly equivalent to booting with vsyscall=none, except
1108 that it will also disable the helpful warning if a program
1109 tries to use a vsyscall. With this option set to N, offending
1110 programs will just segfault, citing addresses of the form
1111 0xffffffffff600?00.
1112
1113 This option is required by many programs built before 2013, and
1114 care should be used even with newer programs if set to N.
1115
1116 Disabling this option saves about 7K of kernel size and
1117 possibly 4K of additional runtime pagetable memory.
1118
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001119config TOSHIBA
1120 tristate "Toshiba Laptop support"
1121 depends on X86_32
1122 ---help---
1123 This adds a driver to safely access the System Management Mode of
1124 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1125 not work on models with a Phoenix BIOS. The System Management Mode
1126 is used to set the BIOS and power saving options on Toshiba portables.
1127
1128 For information on utilities to make use of this driver see the
1129 Toshiba Linux utilities web site at:
1130 <http://www.buzzard.org.uk/toshiba/>.
1131
1132 Say Y if you intend to run this kernel on a Toshiba portable.
1133 Say N otherwise.
1134
1135config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001136 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001137 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001138 select SENSORS_DELL_SMM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001139 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001140 This option enables legacy /proc/i8k userspace interface in hwmon
1141 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1142 temperature and allows controlling fan speeds of Dell laptops via
1143 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1144 it reports also power and hotkey status. For fan speed control is
1145 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001146
Pali Rohár039ae582015-05-14 13:16:37 +02001147 Say Y if you intend to run this kernel on old Dell laptops or want to
1148 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001149 Say N otherwise.
1150
1151config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001152 bool "Enable X86 board specific fixups for reboot"
1153 depends on X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001154 ---help---
1155 This enables chipset and/or board specific fixups to be done
1156 in order to get reboot to work correctly. This is only needed on
1157 some combinations of hardware and BIOS. The symptom, for which
1158 this config is intended, is when reboot ends with a stalled/hung
1159 system.
1160
1161 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001162 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001163
1164 Say Y if you want to enable the fixup. Currently, it's safe to
1165 enable this option even if you don't need it.
1166 Say N otherwise.
1167
1168config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001169 bool "CPU microcode loading support"
1170 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001171 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001172 select FW_LOADER
1173 ---help---
1174 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001175 Intel and AMD processors. The Intel support is for the IA32 family,
1176 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1177 AMD support is for families 0x10 and later. You will obviously need
1178 the actual microcode binary data itself which is not shipped with
1179 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001180
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001181 The preferred method to load microcode from a detached initrd is described
1182 in Documentation/x86/early-microcode.txt. For that you need to enable
1183 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1184 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001185
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001186 In addition, you can build-in the microcode into the kernel. For that you
1187 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1188 to the CONFIG_EXTRA_FIRMWARE config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001189
Peter Oruba8d86f392008-07-28 18:44:21 +02001190config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001191 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001192 depends on MICROCODE
1193 default MICROCODE
1194 select FW_LOADER
1195 ---help---
1196 This options enables microcode patch loading support for Intel
1197 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001198
Alanb8989db2014-01-20 18:01:56 +00001199 For the current Intel microcode data package go to
1200 <https://downloadcenter.intel.com> and search for
1201 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001202
Peter Oruba80cc9f12008-07-28 18:44:22 +02001203config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001204 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001205 depends on MICROCODE
1206 select FW_LOADER
1207 ---help---
1208 If you select this option, microcode patch loading support for AMD
1209 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001210
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001211config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001212 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001213 depends on MICROCODE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001214
1215config X86_MSR
1216 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001217 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001218 This device gives privileged processes access to the x86
1219 Model-Specific Registers (MSRs). It is a character device with
1220 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1221 MSR accesses are directed to a specific CPU on multi-processor
1222 systems.
1223
1224config X86_CPUID
1225 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001226 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001227 This device gives processes access to the x86 CPUID instruction to
1228 be executed on a specific processor. It is a character device
1229 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1230 /dev/cpu/31/cpuid.
1231
1232choice
1233 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001234 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001235 depends on X86_32
1236
1237config NOHIGHMEM
1238 bool "off"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001239 ---help---
1240 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1241 However, the address space of 32-bit x86 processors is only 4
1242 Gigabytes large. That means that, if you have a large amount of
1243 physical memory, not all of it can be "permanently mapped" by the
1244 kernel. The physical memory that's not permanently mapped is called
1245 "high memory".
1246
1247 If you are compiling a kernel which will never run on a machine with
1248 more than 1 Gigabyte total physical RAM, answer "off" here (default
1249 choice and suitable for most users). This will result in a "3GB/1GB"
1250 split: 3GB are mapped so that each process sees a 3GB virtual memory
1251 space and the remaining part of the 4GB virtual memory space is used
1252 by the kernel to permanently map as much physical memory as
1253 possible.
1254
1255 If the machine has between 1 and 4 Gigabytes physical RAM, then
1256 answer "4GB" here.
1257
1258 If more than 4 Gigabytes is used then answer "64GB" here. This
1259 selection turns Intel PAE (Physical Address Extension) mode on.
1260 PAE implements 3-level paging on IA32 processors. PAE is fully
1261 supported by Linux, PAE mode is implemented on all recent Intel
1262 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1263 then the kernel will not boot on CPUs that don't support PAE!
1264
1265 The actual amount of total physical memory will either be
1266 auto detected or can be forced by using a kernel command line option
1267 such as "mem=256M". (Try "man bootparam" or see the documentation of
1268 your boot loader (lilo or loadlin) about how to pass options to the
1269 kernel at boot time.)
1270
1271 If unsure, say "off".
1272
1273config HIGHMEM4G
1274 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001275 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001276 Select this if you have a 32-bit processor and between 1 and 4
1277 gigabytes of physical RAM.
1278
1279config HIGHMEM64G
1280 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001281 depends on !M486
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001282 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001283 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001284 Select this if you have a 32-bit processor and more than 4
1285 gigabytes of physical RAM.
1286
1287endchoice
1288
1289choice
David Rientjes6a108a12011-01-20 14:44:16 -08001290 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001291 default VMSPLIT_3G
1292 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001293 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001294 Select the desired split between kernel and user memory.
1295
1296 If the address range available to the kernel is less than the
1297 physical memory installed, the remaining memory will be available
1298 as "high memory". Accessing high memory is a little more costly
1299 than low memory, as it needs to be mapped into the kernel first.
1300 Note that increasing the kernel address space limits the range
1301 available to user programs, making the address space there
1302 tighter. Selecting anything other than the default 3G/1G split
1303 will also likely make your kernel incompatible with binary-only
1304 kernel modules.
1305
1306 If you are not absolutely sure what you are doing, leave this
1307 option alone!
1308
1309 config VMSPLIT_3G
1310 bool "3G/1G user/kernel split"
1311 config VMSPLIT_3G_OPT
1312 depends on !X86_PAE
1313 bool "3G/1G user/kernel split (for full 1G low memory)"
1314 config VMSPLIT_2G
1315 bool "2G/2G user/kernel split"
1316 config VMSPLIT_2G_OPT
1317 depends on !X86_PAE
1318 bool "2G/2G user/kernel split (for full 2G low memory)"
1319 config VMSPLIT_1G
1320 bool "1G/3G user/kernel split"
1321endchoice
1322
1323config PAGE_OFFSET
1324 hex
1325 default 0xB0000000 if VMSPLIT_3G_OPT
1326 default 0x80000000 if VMSPLIT_2G
1327 default 0x78000000 if VMSPLIT_2G_OPT
1328 default 0x40000000 if VMSPLIT_1G
1329 default 0xC0000000
1330 depends on X86_32
1331
1332config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001333 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001334 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001335
1336config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001337 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001338 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001339 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001340 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001341 PAE is required for NX support, and furthermore enables
1342 larger swapspace support for non-overcommit purposes. It
1343 has the cost of more pagetable lookup overhead, and also
1344 consumes more pagetable space per process.
1345
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001346config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001347 def_bool y
1348 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001349
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001350config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001351 def_bool y
1352 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001353
Ingo Molnar10971ab2015-03-05 08:18:23 +01001354config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001355 def_bool y
1356 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001357 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001358 Certain kernel features effectively disable kernel
1359 linear 1 GB mappings (even if the CPU otherwise
1360 supports them), so don't confuse the user by printing
1361 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001362
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001363# Common NUMA Features
1364config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001365 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001366 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001367 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1368 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001369 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001370 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001371
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001372 The kernel will try to allocate memory used by a CPU on the
1373 local memory controller of the CPU and add some more
1374 NUMA awareness to the kernel.
1375
Ingo Molnarc280ea52008-11-08 13:29:45 +01001376 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001377 (or later), AMD Opteron, or EM64T NUMA.
1378
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001379 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001380 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001381
1382 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001383
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001384config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001385 def_bool y
1386 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001387 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001388 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001389 Enable AMD NUMA node topology detection. You should say Y here if
1390 you have a multi processor AMD system. This uses an old method to
1391 read the NUMA configuration directly from the builtin Northbridge
1392 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1393 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001394
1395config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001396 def_bool y
1397 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001398 depends on X86_64 && NUMA && ACPI && PCI
1399 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001400 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001401 Enable ACPI SRAT based node topology detection.
1402
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001403# Some NUMA nodes have memory ranges that span
1404# other nodes. Even though a pfn is valid and
1405# between a node's start and end pfns, it may not
1406# reside on that node. See memmap_init_zone()
1407# for details.
1408config NODES_SPAN_OTHER_NODES
1409 def_bool y
1410 depends on X86_64_ACPI_NUMA
1411
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001412config NUMA_EMU
1413 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001414 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001415 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001416 Enable NUMA emulation. A flat machine will be split
1417 into virtual nodes when booted with "numa=fake=N", where N is the
1418 number of nodes. This is only useful for debugging.
1419
1420config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001421 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001422 range 1 10
1423 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001424 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001425 default "3"
1426 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001427 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001428 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001429 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001430
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001431config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001432 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001433 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001434
1435config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001436 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001437 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001438
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001439config ARCH_FLATMEM_ENABLE
1440 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001441 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001442
1443config ARCH_DISCONTIGMEM_ENABLE
1444 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001445 depends on NUMA && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001446
1447config ARCH_DISCONTIGMEM_DEFAULT
1448 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001449 depends on NUMA && X86_32
1450
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001451config ARCH_SPARSEMEM_ENABLE
1452 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001453 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001454 select SPARSEMEM_STATIC if X86_32
1455 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1456
Tejun Heo3b166512011-04-01 11:15:12 +02001457config ARCH_SPARSEMEM_DEFAULT
1458 def_bool y
1459 depends on X86_64
1460
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001461config ARCH_SELECT_MEMORY_MODEL
1462 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001463 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001464
1465config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001466 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001467 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001468 help
1469 This option enables a sysfs memory/probe interface for testing.
1470 See Documentation/memory-hotplug.txt for more information.
1471 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001472
Tejun Heo3b166512011-04-01 11:15:12 +02001473config ARCH_PROC_KCORE_TEXT
1474 def_bool y
1475 depends on X86_64 && PROC_KCORE
1476
Avi Kivitya29815a2010-01-10 16:28:09 +02001477config ILLEGAL_POINTER_VALUE
1478 hex
1479 default 0 if X86_32
1480 default 0xdead000000000000 if X86_64
1481
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001482source "mm/Kconfig"
1483
Dan Williams7a678322015-08-19 00:34:34 -04001484config X86_PMEM_LEGACY_DEVICE
1485 bool
1486
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001487config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001488 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001489 depends on PHYS_ADDR_T_64BIT
1490 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001491 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001492 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001493 help
1494 Treat memory marked using the non-standard e820 type of 12 as used
1495 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1496 The kernel will offer these regions to the 'pmem' driver so
1497 they can be used for persistent storage.
1498
1499 Say Y if unsure.
1500
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001501config HIGHPTE
1502 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001503 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001504 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001505 The VM uses one page table entry for each page of physical memory.
1506 For systems with a lot of RAM, this can be wasteful of precious
1507 low memory. Setting this option will put user-space page table
1508 entries in high memory.
1509
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001510config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001511 bool "Check for low memory corruption"
1512 ---help---
1513 Periodically check for memory corruption in low memory, which
1514 is suspected to be caused by BIOS. Even when enabled in the
1515 configuration, it is disabled at runtime. Enable it by
1516 setting "memory_corruption_check=1" on the kernel command
1517 line. By default it scans the low 64k of memory every 60
1518 seconds; see the memory_corruption_check_size and
1519 memory_corruption_check_period parameters in
1520 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001521
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001522 When enabled with the default parameters, this option has
1523 almost no overhead, as it reserves a relatively small amount
1524 of memory and scans it infrequently. It both detects corruption
1525 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001526
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001527 It is, however, intended as a diagnostic tool; if repeatable
1528 BIOS-originated corruption always affects the same memory,
1529 you can use memmap= to prevent the kernel from using that
1530 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001531
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001532config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001533 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001534 depends on X86_CHECK_BIOS_CORRUPTION
1535 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001536 ---help---
1537 Set whether the default state of memory_corruption_check is
1538 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001539
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001540config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001541 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1542 default 64
1543 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001544 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001545 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001546
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001547 The first page contains BIOS data structures that the kernel
1548 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001549
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001550 By default we reserve the first 64K of physical RAM, as a
1551 number of BIOSes are known to corrupt that memory range
1552 during events such as suspend/resume or monitor cable
1553 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001554
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001555 You can set this to 4 if you are absolutely sure that you
1556 trust the BIOS to get all its memory reservations and usages
1557 right. If you know your BIOS have problems beyond the
1558 default 64K area, you can set this to 640 to avoid using the
1559 entire low memory range.
1560
1561 If you have doubts about the BIOS (e.g. suspend/resume does
1562 not work or there's kernel crashes after certain hardware
1563 hotplug events) then you might want to enable
1564 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1565 typical corruption patterns.
1566
1567 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001568
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001569config MATH_EMULATION
1570 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001571 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001572 prompt "Math emulation" if X86_32
1573 ---help---
1574 Linux can emulate a math coprocessor (used for floating point
1575 operations) if you don't have one. 486DX and Pentium processors have
1576 a math coprocessor built in, 486SX and 386 do not, unless you added
1577 a 487DX or 387, respectively. (The messages during boot time can
1578 give you some hints here ["man dmesg"].) Everyone needs either a
1579 coprocessor or this emulation.
1580
1581 If you don't have a math coprocessor, you need to say Y here; if you
1582 say Y here even though you have a coprocessor, the coprocessor will
1583 be used nevertheless. (This behavior can be changed with the kernel
1584 command line option "no387", which comes handy if your coprocessor
1585 is broken. Try "man bootparam" or see the documentation of your boot
1586 loader (lilo or loadlin) about how to pass options to the kernel at
1587 boot time.) This means that it is a good idea to say Y here if you
1588 intend to use this kernel on different machines.
1589
1590 More information about the internals of the Linux math coprocessor
1591 emulation can be found in <file:arch/x86/math-emu/README>.
1592
1593 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1594 kernel, it won't hurt.
1595
1596config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001597 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001598 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001599 ---help---
1600 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1601 the Memory Type Range Registers (MTRRs) may be used to control
1602 processor access to memory ranges. This is most useful if you have
1603 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1604 allows bus write transfers to be combined into a larger transfer
1605 before bursting over the PCI/AGP bus. This can increase performance
1606 of image write operations 2.5 times or more. Saying Y here creates a
1607 /proc/mtrr file which may be used to manipulate your processor's
1608 MTRRs. Typically the X server should use this.
1609
1610 This code has a reasonably generic interface so that similar
1611 control registers on other processors can be easily supported
1612 as well:
1613
1614 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1615 Registers (ARRs) which provide a similar functionality to MTRRs. For
1616 these, the ARRs are used to emulate the MTRRs.
1617 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1618 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1619 write-combining. All of these processors are supported by this code
1620 and it makes sense to say Y here if you have one of them.
1621
1622 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1623 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1624 can lead to all sorts of problems, so it's good to say Y here.
1625
1626 You can safely say Y even if your machine doesn't have MTRRs, you'll
1627 just add about 9 KB to your kernel.
1628
Randy Dunlap7225e752008-07-26 17:54:22 -07001629 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001630
Yinghai Lu95ffa242008-04-29 03:52:33 -07001631config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001632 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001633 prompt "MTRR cleanup support"
1634 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001635 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001636 Convert MTRR layout from continuous to discrete, so X drivers can
1637 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001638
Thomas Gleixneraba37282008-07-15 14:48:48 +02001639 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001640 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001641 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001642
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001643 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001644
1645config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001646 int "MTRR cleanup enable value (0-1)"
1647 range 0 1
1648 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001649 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001650 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001651 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001652
Yinghai Lu12031a62008-05-02 02:40:22 -07001653config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1654 int "MTRR cleanup spare reg num (0-7)"
1655 range 0 7
1656 default "1"
1657 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001658 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001659 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001660 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001661
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001662config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001663 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001664 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001665 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001666 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001667 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001668
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001669 PATs are the modern equivalents of MTRRs and are much more
1670 flexible than MTRRs.
1671
1672 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001673 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001674
1675 If unsure, say Y.
1676
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001677config ARCH_USES_PG_UNCACHED
1678 def_bool y
1679 depends on X86_PAT
1680
H. Peter Anvin628c6242011-07-31 13:59:29 -07001681config ARCH_RANDOM
1682 def_bool y
1683 prompt "x86 architectural random number generator" if EXPERT
1684 ---help---
1685 Enable the x86 architectural RDRAND instruction
1686 (Intel Bull Mountain technology) to generate random numbers.
1687 If supported, this is a high bandwidth, cryptographically
1688 secure hardware random number generator.
1689
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001690config X86_SMAP
1691 def_bool y
1692 prompt "Supervisor Mode Access Prevention" if EXPERT
1693 ---help---
1694 Supervisor Mode Access Prevention (SMAP) is a security
1695 feature in newer Intel processors. There is a small
1696 performance cost if this enabled and turned on; there is
1697 also a small increase in the kernel size if this is enabled.
1698
1699 If unsure, say Y.
1700
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001701config X86_INTEL_MPX
1702 prompt "Intel MPX (Memory Protection Extensions)"
1703 def_bool n
1704 depends on CPU_SUP_INTEL
1705 ---help---
1706 MPX provides hardware features that can be used in
1707 conjunction with compiler-instrumented code to check
1708 memory references. It is designed to detect buffer
1709 overflow or underflow bugs.
1710
1711 This option enables running applications which are
1712 instrumented or otherwise use MPX. It does not use MPX
1713 itself inside the kernel or to protect the kernel
1714 against bad memory references.
1715
1716 Enabling this option will make the kernel larger:
1717 ~8k of kernel text and 36 bytes of data on a 64-bit
1718 defconfig. It adds a long to the 'mm_struct' which
1719 will increase the kernel memory overhead of each
1720 process and adds some branches to paths used during
1721 exec() and munmap().
1722
1723 For details, see Documentation/x86/intel_mpx.txt
1724
1725 If unsure, say N.
1726
Dave Hansen35e97792016-02-12 13:02:00 -08001727config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001728 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001729 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001730 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001731 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001732 ---help---
1733 Memory Protection Keys provides a mechanism for enforcing
1734 page-based protections, but without requiring modification of the
1735 page tables when an application changes protection domains.
1736
1737 For details, see Documentation/x86/protection-keys.txt
1738
1739 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001740
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001741config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001742 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001743 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001744 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001745 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001746 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001747 This enables the kernel to use EFI runtime services that are
1748 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001749
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001750 This option is only useful on systems that have EFI firmware.
1751 In addition, you should use the latest ELILO loader available
1752 at <http://elilo.sourceforge.net> in order to take advantage
1753 of EFI runtime services. However, even with this option, the
1754 resultant kernel should continue to boot on existing non-EFI
1755 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001756
Matt Fleming291f3632011-12-12 21:27:52 +00001757config EFI_STUB
1758 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001759 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001760 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001761 ---help---
1762 This kernel feature allows a bzImage to be loaded directly
1763 by EFI firmware without the use of a bootloader.
1764
Roy Franz4172fe22013-09-22 15:45:25 -07001765 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001766
Matt Fleming7d453ee2014-01-10 18:52:06 +00001767config EFI_MIXED
1768 bool "EFI mixed-mode support"
1769 depends on EFI_STUB && X86_64
1770 ---help---
1771 Enabling this feature allows a 64-bit kernel to be booted
1772 on a 32-bit firmware, provided that your CPU supports 64-bit
1773 mode.
1774
1775 Note that it is not possible to boot a mixed-mode enabled
1776 kernel via the EFI boot stub - a bootloader that supports
1777 the EFI handover protocol must be used.
1778
1779 If unsure, say N.
1780
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001781config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001782 def_bool y
1783 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001784 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001785 This kernel feature is useful for number crunching applications
1786 that may need to compute untrusted bytecode during their
1787 execution. By using pipes or other transports made available to
1788 the process as file descriptors supporting the read/write
1789 syscalls, it's possible to isolate those applications in
1790 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001791 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001792 and the task is only allowed to execute a few safe syscalls
1793 defined by each seccomp mode.
1794
1795 If unsure, say Y. Only embedded should say N here.
1796
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001797source kernel/Kconfig.hz
1798
1799config KEXEC
1800 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001801 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001802 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001803 kexec is a system call that implements the ability to shutdown your
1804 current kernel, and to start another kernel. It is like a reboot
1805 but it is independent of the system firmware. And like a reboot
1806 you can start any kernel with it, not just Linux.
1807
1808 The name comes from the similarity to the exec system call.
1809
1810 It is an ongoing process to be certain the hardware in a machine
1811 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001812 initially work for you. As of this writing the exact hardware
1813 interface is strongly in flux, so no good recommendation can be
1814 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001815
Vivek Goyal74ca3172014-08-29 15:18:46 -07001816config KEXEC_FILE
1817 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001818 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001819 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001820 depends on X86_64
1821 depends on CRYPTO=y
1822 depends on CRYPTO_SHA256=y
1823 ---help---
1824 This is new version of kexec system call. This system call is
1825 file based and takes file descriptors as system call argument
1826 for kernel and initramfs as opposed to list of segments as
1827 accepted by previous system call.
1828
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001829config KEXEC_VERIFY_SIG
1830 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001831 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001832 ---help---
1833 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001834 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001835
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001836 In addition to that option, you need to enable signature
1837 verification for the corresponding kernel image type being
1838 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001839
1840config KEXEC_BZIMAGE_VERIFY_SIG
1841 bool "Enable bzImage signature verification support"
1842 depends on KEXEC_VERIFY_SIG
1843 depends on SIGNED_PE_FILE_VERIFICATION
1844 select SYSTEM_TRUSTED_KEYRING
1845 ---help---
1846 Enable bzImage signature verification support.
1847
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001848config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001849 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001850 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001851 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001852 Generate crash dump after being started by kexec.
1853 This should be normally only set in special crash dump kernels
1854 which are loaded in the main kernel with kexec-tools into
1855 a specially reserved region and then later executed after
1856 a crash by kdump/kexec. The crash dump kernel must be compiled
1857 to a memory address not used by the main kernel or BIOS using
1858 PHYSICAL_START, or it must be built as a relocatable image
1859 (CONFIG_RELOCATABLE=y).
1860 For more details see Documentation/kdump/kdump.txt
1861
Huang Ying3ab83522008-07-25 19:45:07 -07001862config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001863 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001864 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001865 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001866 Jump between original kernel and kexeced kernel and invoke
1867 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001868
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001869config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001870 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001871 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001872 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001873 This gives the physical address where the kernel is loaded.
1874
1875 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1876 bzImage will decompress itself to above physical address and
1877 run from there. Otherwise, bzImage will run from the address where
1878 it has been loaded by the boot loader and will ignore above physical
1879 address.
1880
1881 In normal kdump cases one does not have to set/change this option
1882 as now bzImage can be compiled as a completely relocatable image
1883 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1884 address. This option is mainly useful for the folks who don't want
1885 to use a bzImage for capturing the crash dump and want to use a
1886 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1887 to be specifically compiled to run from a specific memory area
1888 (normally a reserved region) and this option comes handy.
1889
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001890 So if you are using bzImage for capturing the crash dump,
1891 leave the value here unchanged to 0x1000000 and set
1892 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1893 for capturing the crash dump change this value to start of
1894 the reserved region. In other words, it can be set based on
1895 the "X" value as specified in the "crashkernel=YM@XM"
1896 command line boot parameter passed to the panic-ed
1897 kernel. Please take a look at Documentation/kdump/kdump.txt
1898 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001899
1900 Usage of bzImage for capturing the crash dump is recommended as
1901 one does not have to build two kernels. Same kernel can be used
1902 as production kernel and capture kernel. Above option should have
1903 gone away after relocatable bzImage support is introduced. But it
1904 is present because there are users out there who continue to use
1905 vmlinux for dump capture. This option should go away down the
1906 line.
1907
1908 Don't change this unless you know what you are doing.
1909
1910config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001911 bool "Build a relocatable kernel"
1912 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001913 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001914 This builds a kernel image that retains relocation information
1915 so it can be loaded someplace besides the default 1MB.
1916 The relocations tend to make the kernel binary about 10% larger,
1917 but are discarded at runtime.
1918
1919 One use is for the kexec on panic case where the recovery kernel
1920 must live at a different physical address than the primary
1921 kernel.
1922
1923 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1924 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001925 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001926
Kees Cook8ab38202013-10-10 17:18:14 -07001927config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07001928 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07001929 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001930 default n
1931 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07001932 In support of Kernel Address Space Layout Randomization (KASLR),
1933 this randomizes the physical address at which the kernel image
1934 is decompressed and the virtual address where the kernel
1935 image is mapped, as a security feature that deters exploit
1936 attempts relying on knowledge of the location of kernel
1937 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07001938
Baoquan Hee8581e32016-04-20 13:55:43 -07001939 The kernel physical and virtual address can be randomized
1940 from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
1941 using RANDOMIZE_BASE reduces the memory space available to
1942 kernel modules from 1.5GB to 1GB.)
Kees Cook8ab38202013-10-10 17:18:14 -07001943
Baoquan Hee8581e32016-04-20 13:55:43 -07001944 Entropy is generated using the RDRAND instruction if it is
1945 supported. If RDTSC is supported, its value is mixed into
1946 the entropy pool as well. If neither RDRAND nor RDTSC are
1947 supported, then entropy is read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001948
Baoquan Hee8581e32016-04-20 13:55:43 -07001949 Since the kernel is built using 2GB addressing, and
1950 PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
1951 entropy is theoretically possible. Currently, with the
1952 default value for PHYSICAL_ALIGN and due to page table
1953 layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
Kees Cookda2b6fb2013-12-10 12:27:45 -08001954
Baoquan Hee8581e32016-04-20 13:55:43 -07001955 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1956 time. To enable it, boot with "kaslr" on the kernel command
1957 line (which will also disable hibernation).
Kees Cook6145cfe2013-10-10 17:18:18 -07001958
Baoquan Hee8581e32016-04-20 13:55:43 -07001959 If unsure, say N.
Kees Cook8ab38202013-10-10 17:18:14 -07001960
1961# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001962config X86_NEED_RELOCS
1963 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001964 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001965
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001966config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001967 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001968 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001969 range 0x2000 0x1000000 if X86_32
1970 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001971 ---help---
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001972 This value puts the alignment restrictions on physical address
1973 where kernel is loaded and run from. Kernel is compiled for an
1974 address which meets above alignment restriction.
1975
1976 If bootloader loads the kernel at a non-aligned address and
1977 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1978 address aligned to above value and run from there.
1979
1980 If bootloader loads the kernel at a non-aligned address and
1981 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1982 load address and decompress itself to the address it has been
1983 compiled for and run from there. The address for which kernel is
1984 compiled already meets above alignment restrictions. Hence the
1985 end result is that kernel runs from a physical address meeting
1986 above alignment restrictions.
1987
Kees Cooka0215062013-07-08 09:15:17 -07001988 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1989 this value must be a multiple of 0x200000.
1990
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001991 Don't change this unless you know what you are doing.
1992
1993config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001994 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001995 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001996 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001997 Say Y here to allow turning CPUs off and on. CPUs can be
1998 controlled through /sys/devices/system/cpu.
1999 ( Note: power management support will enable this option
2000 automatically on SMP systems. )
2001 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002002
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002003config BOOTPARAM_HOTPLUG_CPU0
2004 bool "Set default setting of cpu0_hotpluggable"
2005 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002006 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002007 ---help---
2008 Set whether default state of cpu0_hotpluggable is on or off.
2009
2010 Say Y here to enable CPU0 hotplug by default. If this switch
2011 is turned on, there is no need to give cpu0_hotplug kernel
2012 parameter and the CPU0 hotplug feature is enabled by default.
2013
2014 Please note: there are two known CPU0 dependencies if you want
2015 to enable the CPU0 hotplug feature either by this switch or by
2016 cpu0_hotplug kernel parameter.
2017
2018 First, resume from hibernate or suspend always starts from CPU0.
2019 So hibernate and suspend are prevented if CPU0 is offline.
2020
2021 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2022 offline if any interrupt can not migrate out of CPU0. There may
2023 be other CPU0 dependencies.
2024
2025 Please make sure the dependencies are under your control before
2026 you enable this feature.
2027
2028 Say N if you don't want to enable CPU0 hotplug feature by default.
2029 You still can enable the CPU0 hotplug feature at boot by kernel
2030 parameter cpu0_hotplug.
2031
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002032config DEBUG_HOTPLUG_CPU0
2033 def_bool n
2034 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002035 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002036 ---help---
2037 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2038 soon as possible and boots up userspace with CPU0 offlined. User
2039 can online CPU0 back after boot time.
2040
2041 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2042 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2043 compilation or giving cpu0_hotplug kernel parameter at boot.
2044
2045 If unsure, say N.
2046
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002047config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002048 def_bool n
2049 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002050 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002051 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002052 Certain buggy versions of glibc will crash if they are
2053 presented with a 32-bit vDSO that is not mapped at the address
2054 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002055
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002056 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2057 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2058 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2059 the only released version with the bug, but OpenSUSE 9
2060 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002061
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002062 The symptom of the bug is that everything crashes on startup, saying:
2063 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2064
2065 Saying Y here changes the default value of the vdso32 boot
2066 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2067 This works around the glibc bug but hurts performance.
2068
2069 If unsure, say N: if you are compiling your own kernel, you
2070 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002071
Kees Cook3dc33bd2015-08-12 17:55:19 -07002072choice
2073 prompt "vsyscall table for legacy applications"
2074 depends on X86_64
2075 default LEGACY_VSYSCALL_EMULATE
2076 help
2077 Legacy user code that does not know how to find the vDSO expects
2078 to be able to issue three syscalls by calling fixed addresses in
2079 kernel space. Since this location is not randomized with ASLR,
2080 it can be used to assist security vulnerability exploitation.
2081
2082 This setting can be changed at boot time via the kernel command
2083 line parameter vsyscall=[native|emulate|none].
2084
2085 On a system with recent enough glibc (2.14 or newer) and no
2086 static binaries, you can say None without a performance penalty
2087 to improve security.
2088
2089 If unsure, select "Emulate".
2090
2091 config LEGACY_VSYSCALL_NATIVE
2092 bool "Native"
2093 help
2094 Actual executable code is located in the fixed vsyscall
2095 address mapping, implementing time() efficiently. Since
2096 this makes the mapping executable, it can be used during
2097 security vulnerability exploitation (traditionally as
2098 ROP gadgets). This configuration is not recommended.
2099
2100 config LEGACY_VSYSCALL_EMULATE
2101 bool "Emulate"
2102 help
2103 The kernel traps and emulates calls into the fixed
2104 vsyscall address mapping. This makes the mapping
2105 non-executable, but it still contains known contents,
2106 which could be used in certain rare security vulnerability
2107 exploits. This configuration is recommended when userspace
2108 still uses the vsyscall area.
2109
2110 config LEGACY_VSYSCALL_NONE
2111 bool "None"
2112 help
2113 There will be no vsyscall mapping at all. This will
2114 eliminate any risk of ASLR bypass due to the vsyscall
2115 fixed address mapping. Attempts to use the vsyscalls
2116 will be reported to dmesg, so that either old or
2117 malicious userspace programs can be identified.
2118
2119endchoice
2120
Tim Bird516cbf32008-08-12 12:52:36 -07002121config CMDLINE_BOOL
2122 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002123 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002124 Allow for specifying boot arguments to the kernel at
2125 build time. On some systems (e.g. embedded ones), it is
2126 necessary or convenient to provide some or all of the
2127 kernel boot arguments with the kernel itself (that is,
2128 to not rely on the boot loader to provide them.)
2129
2130 To compile command line arguments into the kernel,
2131 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002132 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002133
2134 Systems with fully functional boot loaders (i.e. non-embedded)
2135 should leave this option set to 'N'.
2136
2137config CMDLINE
2138 string "Built-in kernel command string"
2139 depends on CMDLINE_BOOL
2140 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002141 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002142 Enter arguments here that should be compiled into the kernel
2143 image and used at boot time. If the boot loader provides a
2144 command line at boot time, it is appended to this string to
2145 form the full kernel command line, when the system boots.
2146
2147 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2148 change this behavior.
2149
2150 In most cases, the command line (whether built-in or provided
2151 by the boot loader) should specify the device for the root
2152 file system.
2153
2154config CMDLINE_OVERRIDE
2155 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002156 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002157 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002158 Set this option to 'Y' to have the kernel ignore the boot loader
2159 command line, and use ONLY the built-in command line.
2160
2161 This is used to work around broken boot loaders. This should
2162 be set to 'N' under normal conditions.
2163
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002164config MODIFY_LDT_SYSCALL
2165 bool "Enable the LDT (local descriptor table)" if EXPERT
2166 default y
2167 ---help---
2168 Linux can allow user programs to install a per-process x86
2169 Local Descriptor Table (LDT) using the modify_ldt(2) system
2170 call. This is required to run 16-bit or segmented code such as
2171 DOSEMU or some Wine programs. It is also used by some very old
2172 threading libraries.
2173
2174 Enabling this feature adds a small amount of overhead to
2175 context switches and increases the low-level kernel attack
2176 surface. Disabling it removes the modify_ldt(2) system call.
2177
2178 Saying 'N' here may make sense for embedded or server kernels.
2179
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002180source "kernel/livepatch/Kconfig"
2181
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002182endmenu
2183
2184config ARCH_ENABLE_MEMORY_HOTPLUG
2185 def_bool y
2186 depends on X86_64 || (X86_32 && HIGHMEM)
2187
Gary Hade35551052008-10-31 10:52:03 -07002188config ARCH_ENABLE_MEMORY_HOTREMOVE
2189 def_bool y
2190 depends on MEMORY_HOTPLUG
2191
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002192config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002193 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002194 depends on NUMA
2195
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002196config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2197 def_bool y
2198 depends on X86_64 || X86_PAE
2199
Naoya Horiguchic177c812014-06-04 16:05:35 -07002200config ARCH_ENABLE_HUGEPAGE_MIGRATION
2201 def_bool y
2202 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2203
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002204menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002205
2206config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002207 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002208 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002209
2210source "kernel/power/Kconfig"
2211
2212source "drivers/acpi/Kconfig"
2213
Feng Tangefafc8b2009-08-14 15:23:29 -04002214source "drivers/sfi/Kconfig"
2215
Andi Kleena6b68072008-01-30 13:32:49 +01002216config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002217 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002218 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002219
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002220menuconfig APM
2221 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002222 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002223 ---help---
2224 APM is a BIOS specification for saving power using several different
2225 techniques. This is mostly useful for battery powered laptops with
2226 APM compliant BIOSes. If you say Y here, the system time will be
2227 reset after a RESUME operation, the /proc/apm device will provide
2228 battery status information, and user-space programs will receive
2229 notification of APM "events" (e.g. battery status change).
2230
2231 If you select "Y" here, you can disable actual use of the APM
2232 BIOS by passing the "apm=off" option to the kernel at boot time.
2233
2234 Note that the APM support is almost completely disabled for
2235 machines with more than one CPU.
2236
2237 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002238 and more information, read <file:Documentation/power/apm-acpi.txt>
2239 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002240 <http://www.tldp.org/docs.html#howto>.
2241
2242 This driver does not spin down disk drives (see the hdparm(8)
2243 manpage ("man 8 hdparm") for that), and it doesn't turn off
2244 VESA-compliant "green" monitors.
2245
2246 This driver does not support the TI 4000M TravelMate and the ACER
2247 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2248 desktop machines also don't have compliant BIOSes, and this driver
2249 may cause those machines to panic during the boot phase.
2250
2251 Generally, if you don't have a battery in your machine, there isn't
2252 much point in using this driver and you should say N. If you get
2253 random kernel OOPSes or reboots that don't seem to be related to
2254 anything, try disabling/enabling this option (or disabling/enabling
2255 APM in your BIOS).
2256
2257 Some other things you should try when experiencing seemingly random,
2258 "weird" problems:
2259
2260 1) make sure that you have enough swap space and that it is
2261 enabled.
2262 2) pass the "no-hlt" option to the kernel
2263 3) switch on floating point emulation in the kernel and pass
2264 the "no387" option to the kernel
2265 4) pass the "floppy=nodma" option to the kernel
2266 5) pass the "mem=4M" option to the kernel (thereby disabling
2267 all but the first 4 MB of RAM)
2268 6) make sure that the CPU is not over clocked.
2269 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2270 8) disable the cache from your BIOS settings
2271 9) install a fan for the video card or exchange video RAM
2272 10) install a better fan for the CPU
2273 11) exchange RAM chips
2274 12) exchange the motherboard.
2275
2276 To compile this driver as a module, choose M here: the
2277 module will be called apm.
2278
2279if APM
2280
2281config APM_IGNORE_USER_SUSPEND
2282 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002283 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002284 This option will ignore USER SUSPEND requests. On machines with a
2285 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2286 series notebooks, it is necessary to say Y because of a BIOS bug.
2287
2288config APM_DO_ENABLE
2289 bool "Enable PM at boot time"
2290 ---help---
2291 Enable APM features at boot time. From page 36 of the APM BIOS
2292 specification: "When disabled, the APM BIOS does not automatically
2293 power manage devices, enter the Standby State, enter the Suspend
2294 State, or take power saving steps in response to CPU Idle calls."
2295 This driver will make CPU Idle calls when Linux is idle (unless this
2296 feature is turned off -- see "Do CPU IDLE calls", below). This
2297 should always save battery power, but more complicated APM features
2298 will be dependent on your BIOS implementation. You may need to turn
2299 this option off if your computer hangs at boot time when using APM
2300 support, or if it beeps continuously instead of suspending. Turn
2301 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2302 T400CDT. This is off by default since most machines do fine without
2303 this feature.
2304
2305config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002306 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002307 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002308 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002309 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2310 On some machines, this can activate improved power savings, such as
2311 a slowed CPU clock rate, when the machine is idle. These idle calls
2312 are made after the idle loop has run for some length of time (e.g.,
2313 333 mS). On some machines, this will cause a hang at boot time or
2314 whenever the CPU becomes idle. (On machines with more than one CPU,
2315 this option does nothing.)
2316
2317config APM_DISPLAY_BLANK
2318 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002319 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002320 Enable console blanking using the APM. Some laptops can use this to
2321 turn off the LCD backlight when the screen blanker of the Linux
2322 virtual console blanks the screen. Note that this is only used by
2323 the virtual console screen blanker, and won't turn off the backlight
2324 when using the X Window system. This also doesn't have anything to
2325 do with your VESA-compliant power-saving monitor. Further, this
2326 option doesn't work for all laptops -- it might not turn off your
2327 backlight at all, or it might print a lot of errors to the console,
2328 especially if you are using gpm.
2329
2330config APM_ALLOW_INTS
2331 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002332 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002333 Normally we disable external interrupts while we are making calls to
2334 the APM BIOS as a measure to lessen the effects of a badly behaving
2335 BIOS implementation. The BIOS should reenable interrupts if it
2336 needs to. Unfortunately, some BIOSes do not -- especially those in
2337 many of the newer IBM Thinkpads. If you experience hangs when you
2338 suspend, try setting this to Y. Otherwise, say N.
2339
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002340endif # APM
2341
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002342source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002343
2344source "drivers/cpuidle/Kconfig"
2345
Andy Henroid27471fd2008-10-09 11:45:22 -07002346source "drivers/idle/Kconfig"
2347
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002348endmenu
2349
2350
2351menu "Bus options (PCI etc.)"
2352
2353config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002354 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002355 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002356 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002357 Find out whether you have a PCI motherboard. PCI is the name of a
2358 bus system, i.e. the way the CPU talks to the other stuff inside
2359 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2360 VESA. If you have PCI, say Y, otherwise N.
2361
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002362choice
2363 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002364 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002365 default PCI_GOANY
2366 ---help---
2367 On PCI systems, the BIOS can be used to detect the PCI devices and
2368 determine their configuration. However, some old PCI motherboards
2369 have BIOS bugs and may crash if this is done. Also, some embedded
2370 PCI-based systems don't have any BIOS at all. Linux can also try to
2371 detect the PCI hardware directly without using the BIOS.
2372
2373 With this option, you can specify how Linux should detect the
2374 PCI devices. If you choose "BIOS", the BIOS will be used,
2375 if you choose "Direct", the BIOS won't be used, and if you
2376 choose "MMConfig", then PCI Express MMCONFIG will be used.
2377 If you choose "Any", the kernel will try MMCONFIG, then the
2378 direct access method and falls back to the BIOS if that doesn't
2379 work. If unsure, go with the default, which is "Any".
2380
2381config PCI_GOBIOS
2382 bool "BIOS"
2383
2384config PCI_GOMMCONFIG
2385 bool "MMConfig"
2386
2387config PCI_GODIRECT
2388 bool "Direct"
2389
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002390config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002391 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002392 depends on OLPC
2393
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002394config PCI_GOANY
2395 bool "Any"
2396
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002397endchoice
2398
2399config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002400 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002401 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002402
2403# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2404config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002405 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002406 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002407
2408config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002409 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002410 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002411
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002412config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002413 def_bool y
2414 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002415
Alex Nixonb5401a92010-03-18 16:31:34 -04002416config PCI_XEN
2417 def_bool y
2418 depends on PCI && XEN
2419 select SWIOTLB_XEN
2420
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002421config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002422 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002423 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002424
2425config PCI_MMCONFIG
2426 bool "Support mmconfig PCI config space access"
2427 depends on X86_64 && PCI && ACPI
2428
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002429config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002430 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002431 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002432 help
2433 Read the PCI windows out of the CNB20LE host bridge. This allows
2434 PCI hotplug to work on systems with the CNB20LE chipset which do
2435 not have ACPI.
2436
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002437 There's no public spec for this chipset, and this functionality
2438 is known to be incomplete.
2439
2440 You should say N unless you know you need this.
2441
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002442source "drivers/pci/Kconfig"
2443
William Breathitt Gray3a495512016-05-27 18:08:27 -04002444config ISA_BUS
2445 bool "ISA-style bus support on modern systems" if EXPERT
2446 select ISA_BUS_API
2447 help
2448 Enables ISA-style drivers on modern systems. This is necessary to
2449 support PC/104 devices on X86_64 platforms.
2450
2451 If unsure, say N.
2452
David Rientjes1c00f012011-03-22 16:34:59 -07002453# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002454config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002455 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2456 default y
2457 help
2458 Enables ISA-style DMA support for devices requiring such controllers.
2459 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002460
Linus Torvalds51e68d02016-05-21 10:25:19 -07002461if X86_32
2462
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002463config ISA
2464 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002465 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002466 Find out whether you have ISA slots on your motherboard. ISA is the
2467 name of a bus system, i.e. the way the CPU talks to the other stuff
2468 inside your box. Other bus systems are PCI, EISA, MicroChannel
2469 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2470 newer boards don't support it. If you have ISA, say Y, otherwise N.
2471
2472config EISA
2473 bool "EISA support"
2474 depends on ISA
2475 ---help---
2476 The Extended Industry Standard Architecture (EISA) bus was
2477 developed as an open alternative to the IBM MicroChannel bus.
2478
2479 The EISA bus provided some of the features of the IBM MicroChannel
2480 bus while maintaining backward compatibility with cards made for
2481 the older ISA bus. The EISA bus saw limited use between 1988 and
2482 1995 when it was made obsolete by the PCI bus.
2483
2484 Say Y here if you are building a kernel for an EISA-based machine.
2485
2486 Otherwise, say N.
2487
2488source "drivers/eisa/Kconfig"
2489
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002490config SCx200
2491 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002492 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493 This provides basic support for National Semiconductor's
2494 (now AMD's) Geode processors. The driver probes for the
2495 PCI-IDs of several on-chip devices, so its a good dependency
2496 for other scx200_* drivers.
2497
2498 If compiled as a module, the driver is named scx200.
2499
2500config SCx200HR_TIMER
2501 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002502 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002503 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002504 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002505 This driver provides a clocksource built upon the on-chip
2506 27MHz high-resolution timer. Its also a workaround for
2507 NSC Geode SC-1100's buggy TSC, which loses time when the
2508 processor goes idle (as is done by the scheduler). The
2509 other workaround is idle=poll boot option.
2510
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002511config OLPC
2512 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002513 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002514 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002515 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002516 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002517 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002518 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002519 Add support for detecting the unique features of the OLPC
2520 XO hardware.
2521
Daniel Drakea3128582011-06-25 17:34:10 +01002522config OLPC_XO1_PM
2523 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002524 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002525 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002526 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002527 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002528
Daniel Drakecfee9592011-06-25 17:34:17 +01002529config OLPC_XO1_RTC
2530 bool "OLPC XO-1 Real Time Clock"
2531 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2532 ---help---
2533 Add support for the XO-1 real time clock, which can be used as a
2534 programmable wakeup source.
2535
Daniel Drake7feda8e2011-06-25 17:34:12 +01002536config OLPC_XO1_SCI
2537 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002538 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002539 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002540 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002541 select GPIO_CS5535
2542 select MFD_CORE
2543 ---help---
2544 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002545 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002546 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002547 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002548 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002549 - AC adapter status updates
2550 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002551
Daniel Drakea0f30f52011-06-25 17:34:18 +01002552config OLPC_XO15_SCI
2553 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002554 depends on OLPC && ACPI
2555 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002556 ---help---
2557 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2558 - EC-driven system wakeups
2559 - AC adapter status updates
2560 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002561
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002562config ALIX
2563 bool "PCEngines ALIX System Support (LED setup)"
2564 select GPIOLIB
2565 ---help---
2566 This option enables system support for the PCEngines ALIX.
2567 At present this just sets up LEDs for GPIO control on
2568 ALIX2/3/6 boards. However, other system specific setup should
2569 get added here.
2570
2571 Note: You must still enable the drivers for GPIO and LED support
2572 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2573
2574 Note: You have to set alix.force=1 for boards with Award BIOS.
2575
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002576config NET5501
2577 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2578 select GPIOLIB
2579 ---help---
2580 This option enables system support for the Soekris Engineering net5501.
2581
Philip A. Prindeville31970592012-01-14 01:45:39 -07002582config GEOS
2583 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2584 select GPIOLIB
2585 depends on DMI
2586 ---help---
2587 This option enables system support for the Traverse Technologies GEOS.
2588
Vivien Didelot7d029122013-01-04 16:18:14 -05002589config TS5500
2590 bool "Technologic Systems TS-5500 platform support"
2591 depends on MELAN
2592 select CHECK_SIGNATURE
2593 select NEW_LEDS
2594 select LEDS_CLASS
2595 ---help---
2596 This option enables system support for the Technologic Systems TS-5500.
2597
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002598endif # X86_32
2599
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002600config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002601 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002602 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002603
2604source "drivers/pcmcia/Kconfig"
2605
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002606config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002607 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002608 depends on PCI
2609 default n
2610 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002611 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002612 infrastructure code to support RapidIO interconnect devices.
2613
2614source "drivers/rapidio/Kconfig"
2615
David Herrmanne3263ab2013-08-02 14:05:22 +02002616config X86_SYSFB
2617 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2618 help
2619 Firmwares often provide initial graphics framebuffers so the BIOS,
2620 bootloader or kernel can show basic video-output during boot for
2621 user-guidance and debugging. Historically, x86 used the VESA BIOS
2622 Extensions and EFI-framebuffers for this, which are mostly limited
2623 to x86.
2624 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2625 framebuffers so the new generic system-framebuffer drivers can be
2626 used on x86. If the framebuffer is not compatible with the generic
2627 modes, it is adverticed as fallback platform framebuffer so legacy
2628 drivers like efifb, vesafb and uvesafb can pick it up.
2629 If this option is not selected, all system framebuffers are always
2630 marked as fallback platform framebuffers as usual.
2631
2632 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2633 not be able to pick up generic system framebuffers if this option
2634 is selected. You are highly encouraged to enable simplefb as
2635 replacement if you select this option. simplefb can correctly deal
2636 with generic system framebuffers. But you should still keep vesafb
2637 and others enabled as fallback if a system framebuffer is
2638 incompatible with simplefb.
2639
2640 If unsure, say Y.
2641
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002642endmenu
2643
2644
2645menu "Executable file formats / Emulations"
2646
2647source "fs/Kconfig.binfmt"
2648
2649config IA32_EMULATION
2650 bool "IA32 Emulation"
2651 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002652 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002653 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002654 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002655 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002656 Include code to run legacy 32-bit programs under a
2657 64-bit kernel. You should likely turn this on, unless you're
2658 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002659
2660config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002661 tristate "IA32 a.out support"
2662 depends on IA32_EMULATION
2663 ---help---
2664 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002665
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002666config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002667 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002668 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002669 ---help---
2670 Include code to run binaries for the x32 native 32-bit ABI
2671 for 64-bit processors. An x32 process gets access to the
2672 full 64-bit register file and wide data path while leaving
2673 pointers at 32 bits for smaller memory footprint.
2674
2675 You will need a recent binutils (2.22 or later) with
2676 elf32_x86_64 support enabled to compile a kernel with this
2677 option set.
2678
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002679config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002680 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002681 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002682
Jan Beulich3120e252012-09-10 12:41:45 +01002683if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002684config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002685 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002686
2687config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002688 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002689 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002690
David Howellsee009e4a02011-03-07 15:06:20 +00002691config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002692 def_bool y
2693 depends on KEYS
2694endif
David Howellsee009e4a02011-03-07 15:06:20 +00002695
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002696endmenu
2697
2698
Keith Packarde5beae12008-11-03 18:21:45 +01002699config HAVE_ATOMIC_IOMAP
2700 def_bool y
2701 depends on X86_32
2702
Alessandro Rubini4692d772012-04-04 19:39:58 +02002703config X86_DEV_DMA_OPS
2704 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002705 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002706
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002707config X86_DMA_REMAP
2708 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002709 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002710
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002711config PMC_ATOM
2712 def_bool y
2713 depends on PCI
2714
Keith Busch185a3832016-01-12 13:18:10 -07002715config VMD
2716 depends on PCI_MSI
2717 tristate "Volume Management Device Driver"
2718 default N
2719 ---help---
2720 Adds support for the Intel Volume Management Device (VMD). VMD is a
2721 secondary PCI host bridge that allows PCI Express root ports,
2722 and devices attached to them, to be removed from the default
2723 PCI domain and placed within the VMD domain. This provides
2724 more bus resources than are otherwise possible with a
2725 single domain. If you know your system provides one of these and
2726 has devices attached to it, say Y; if you are not sure, say N.
2727
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002728source "net/Kconfig"
2729
2730source "drivers/Kconfig"
2731
2732source "drivers/firmware/Kconfig"
2733
2734source "fs/Kconfig"
2735
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002736source "arch/x86/Kconfig.debug"
2737
2738source "security/Kconfig"
2739
2740source "crypto/Kconfig"
2741
Avi Kivityedf88412007-12-16 11:02:48 +02002742source "arch/x86/kvm/Kconfig"
2743
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002744source "lib/Kconfig"