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Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01001# Select 32 or 64 bit
2config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01003 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00004 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01005 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01006 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010010 def_bool y
11 depends on !64BIT
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010012
13config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010014 def_bool y
15 depends on 64BIT
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010016
17### Arch settings
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010018config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010019 def_bool y
Ingo Molnar6471b822015-06-03 10:00:13 +020020 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Stephen Boyd446f24d2013-04-30 15:28:42 -070026 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Dan Williams21266be2015-11-19 18:19:29 -080027 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020028 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070029 select ARCH_HAS_FAST_MULTIPLIER
Riku Voipio957e3fa2014-12-12 16:57:44 -080030 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070031 select ARCH_HAS_KCOV if X86_64
Dan Williams96601ad2015-08-24 18:29:38 -040032 select ARCH_HAS_PMEM_API if X86_64
Ross Zwisler67a3e8f2015-08-27 13:14:20 -060033 select ARCH_HAS_MMIO_FLUSH
Ingo Molnar6471b822015-06-03 10:00:13 +020034 select ARCH_HAS_SG_CHAIN
Andrey Ryabininc6d30852016-01-20 15:00:55 -080035 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020036 select ARCH_HAVE_NMI_SAFE_CMPXCHG
37 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040038 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080039 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020040 select ARCH_SUPPORTS_ATOMIC_RMW
Mel Gorman3b242c62015-06-30 14:57:13 -070041 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
Ingo Molnar6471b822015-06-03 10:00:13 +020042 select ARCH_SUPPORTS_INT128 if X86_64
43 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
44 select ARCH_USE_BUILTIN_BSWAP
45 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
46 select ARCH_USE_QUEUED_RWLOCKS
47 select ARCH_USE_QUEUED_SPINLOCKS
Mel Gorman72b252a2015-09-04 15:47:32 -070048 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +020049 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Ingo Molnarda4276b2009-01-07 11:05:10 +010050 select ARCH_WANT_FRAME_POINTERS
Ingo Molnar6471b822015-06-03 10:00:13 +020051 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
52 select ARCH_WANT_OPTIONAL_GPIOLIB
53 select BUILDTIME_EXTABLE_SORT
54 select CLKEVT_I8253
55 select CLKSRC_I8253 if X86_32
56 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
57 select CLOCKSOURCE_WATCHDOG
58 select CLONE_BACKWARDS if X86_32
59 select COMPAT_OLD_SIGACTION if IA32_EMULATION
60 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070061 select EDAC_ATOMIC_SCRUB
62 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020063 select GENERIC_CLOCKEVENTS
64 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
65 select GENERIC_CLOCKEVENTS_MIN_ADJUST
66 select GENERIC_CMOS_UPDATE
67 select GENERIC_CPU_AUTOPROBE
68 select GENERIC_EARLY_IOREMAP
69 select GENERIC_FIND_FIRST_BIT
70 select GENERIC_IOMAP
71 select GENERIC_IRQ_PROBE
72 select GENERIC_IRQ_SHOW
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_SMP_IDLE_THREAD
75 select GENERIC_STRNCPY_FROM_USER
76 select GENERIC_STRNLEN_USER
77 select GENERIC_TIME_VSYSCALL
78 select HAVE_ACPI_APEI if ACPI
79 select HAVE_ACPI_APEI_NMI if ACPI
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_AOUT if X86_32
82 select HAVE_ARCH_AUDITSYSCALL
83 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
84 select HAVE_ARCH_JUMP_LABEL
85 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
86 select HAVE_ARCH_KGDB
87 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080088 select HAVE_ARCH_MMAP_RND_BITS if MMU
89 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020090 select HAVE_ARCH_SECCOMP_FILTER
91 select HAVE_ARCH_SOFT_DIRTY if X86_64
92 select HAVE_ARCH_TRACEHOOK
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
94 select HAVE_BPF_JIT if X86_64
95 select HAVE_CC_STACKPROTECTOR
96 select HAVE_CMPXCHG_DOUBLE
97 select HAVE_CMPXCHG_LOCAL
98 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -070099 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select HAVE_C_RECORDMCOUNT
101 select HAVE_DEBUG_KMEMLEAK
102 select HAVE_DEBUG_STACKOVERFLOW
103 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700104 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400105 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900106 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700107 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Ingo Molnar6471b822015-06-03 10:00:13 +0200108 select HAVE_FENTRY if X86_64
109 select HAVE_FTRACE_MCOUNT_RECORD
110 select HAVE_FUNCTION_GRAPH_FP_TEST
111 select HAVE_FUNCTION_GRAPH_TRACER
112 select HAVE_FUNCTION_TRACER
113 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530114 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200115 select HAVE_IDE
116 select HAVE_IOREMAP_PROT
117 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
118 select HAVE_IRQ_TIME_ACCOUNTING
119 select HAVE_KERNEL_BZIP2
120 select HAVE_KERNEL_GZIP
121 select HAVE_KERNEL_LZ4
122 select HAVE_KERNEL_LZMA
123 select HAVE_KERNEL_LZO
124 select HAVE_KERNEL_XZ
125 select HAVE_KPROBES
126 select HAVE_KPROBES_ON_FTRACE
127 select HAVE_KRETPROBES
128 select HAVE_KVM
129 select HAVE_LIVEPATCH if X86_64
130 select HAVE_MEMBLOCK
131 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200132 select HAVE_MIXED_BREAKPOINTS_REGS
Ingo Molnar6471b822015-06-03 10:00:13 +0200133 select HAVE_OPROFILE
134 select HAVE_OPTPROBES
135 select HAVE_PCSPKR_PLATFORM
136 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200137 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200138 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200139 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200140 select HAVE_REGS_AND_STACK_ACCESS_API
141 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400142 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200143 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300144 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100145 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200146 select MODULES_USE_ELF_RELA if X86_64
147 select MODULES_USE_ELF_REL if X86_32
148 select OLD_SIGACTION if X86_32
149 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
150 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500151 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200152 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500153 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200154 select SYSCTL_EXCEPTION_TRACE
155 select USER_STACKTRACE_SUPPORT
156 select VIRT_TO_BUS
157 select X86_DEV_DMA_OPS if X86_64
158 select X86_FEATURE_NAMES if PROC_FS
Josh Poimboeufd4883d52016-02-28 22:22:43 -0600159 select HAVE_STACK_VALIDATION if X86_64
Dave Hansen63c17fb2016-02-12 13:02:08 -0800160 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen66d37572016-02-12 13:02:32 -0800161 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530162
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200163config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100164 def_bool y
165 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200166
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200167config PERF_EVENTS_INTEL_UNCORE
168 def_bool y
Peter Zijlstra (Intel)ce5686d2014-10-29 11:17:04 +0100169 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +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 Ravnborgb9b39bf2008-04-29 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 Ravnborgb9b39bf2008-04-29 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Persvold44b111b2011-12-06 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 Persvold44b111b2011-12-06 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 Persvold44b111b2011-12-06 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 21:56:54 +0100691
Borislav Petkov6276a072013-03-04 21:20:21 +0100692if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 21:56:54 +0100794
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100795 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 21:56:54 +0100825config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700826 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 21:56:54 +0100867 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100868 ---help---
Sam Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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 Ravnborg506f1d02007-11-09 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
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001049config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001050 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001051 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001052 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001053 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001054 This option allows user programs to put the CPU into V8086
1055 mode, which is an 80286-era approximation of 16-bit real mode.
1056
1057 Some very old versions of X and/or vbetool require this option
1058 for user mode setting. Similarly, DOSEMU will use it if
1059 available to accelerate real mode DOS programs. However, any
1060 recent version of DOSEMU, X, or vbetool should be fully
1061 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001062 fall back to software emulation. Nevertheless, if you are using
1063 a 16-bit DOS program where 16-bit performance matters, vm86
1064 mode might be faster than emulation and you might want to
1065 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001066
Ingo Molnar1e642812015-09-05 08:58:10 +02001067 Note that any app that works on a 64-bit kernel is unlikely to
1068 need this option, as 64-bit kernels don't, and can't, support
1069 V8086 mode. This option is also unrelated to 16-bit protected
1070 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001071
Ingo Molnar1e642812015-09-05 08:58:10 +02001072 Enabling this option increases the complexity of the kernel
1073 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001074
Ingo Molnar1e642812015-09-05 08:58:10 +02001075 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001076
1077config VM86
1078 bool
1079 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001080
1081config X86_16BIT
1082 bool "Enable support for 16-bit segments" if EXPERT
1083 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001084 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001085 ---help---
1086 This option is required by programs like Wine to run 16-bit
1087 protected mode legacy code on x86 processors. Disabling
1088 this option saves about 300 bytes on i386, or around 6K text
1089 plus 16K runtime memory on x86-64,
1090
1091config X86_ESPFIX32
1092 def_bool y
1093 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001094
H. Peter Anvin197725d2014-05-04 10:00:49 -07001095config X86_ESPFIX64
1096 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001097 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001098
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001099config X86_VSYSCALL_EMULATION
1100 bool "Enable vsyscall emulation" if EXPERT
1101 default y
1102 depends on X86_64
1103 ---help---
1104 This enables emulation of the legacy vsyscall page. Disabling
1105 it is roughly equivalent to booting with vsyscall=none, except
1106 that it will also disable the helpful warning if a program
1107 tries to use a vsyscall. With this option set to N, offending
1108 programs will just segfault, citing addresses of the form
1109 0xffffffffff600?00.
1110
1111 This option is required by many programs built before 2013, and
1112 care should be used even with newer programs if set to N.
1113
1114 Disabling this option saves about 7K of kernel size and
1115 possibly 4K of additional runtime pagetable memory.
1116
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001117config TOSHIBA
1118 tristate "Toshiba Laptop support"
1119 depends on X86_32
1120 ---help---
1121 This adds a driver to safely access the System Management Mode of
1122 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1123 not work on models with a Phoenix BIOS. The System Management Mode
1124 is used to set the BIOS and power saving options on Toshiba portables.
1125
1126 For information on utilities to make use of this driver see the
1127 Toshiba Linux utilities web site at:
1128 <http://www.buzzard.org.uk/toshiba/>.
1129
1130 Say Y if you intend to run this kernel on a Toshiba portable.
1131 Say N otherwise.
1132
1133config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001134 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001135 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001136 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001137 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001138 This option enables legacy /proc/i8k userspace interface in hwmon
1139 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1140 temperature and allows controlling fan speeds of Dell laptops via
1141 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1142 it reports also power and hotkey status. For fan speed control is
1143 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001144
Pali Rohár039ae582015-05-14 13:16:37 +02001145 Say Y if you intend to run this kernel on old Dell laptops or want to
1146 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001147 Say N otherwise.
1148
1149config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001150 bool "Enable X86 board specific fixups for reboot"
1151 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001152 ---help---
1153 This enables chipset and/or board specific fixups to be done
1154 in order to get reboot to work correctly. This is only needed on
1155 some combinations of hardware and BIOS. The symptom, for which
1156 this config is intended, is when reboot ends with a stalled/hung
1157 system.
1158
1159 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001160 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001161
1162 Say Y if you want to enable the fixup. Currently, it's safe to
1163 enable this option even if you don't need it.
1164 Say N otherwise.
1165
1166config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001167 bool "CPU microcode loading support"
1168 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001169 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001170 select FW_LOADER
1171 ---help---
1172 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001173 Intel and AMD processors. The Intel support is for the IA32 family,
1174 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1175 AMD support is for families 0x10 and later. You will obviously need
1176 the actual microcode binary data itself which is not shipped with
1177 the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001178
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001179 The preferred method to load microcode from a detached initrd is described
1180 in Documentation/x86/early-microcode.txt. For that you need to enable
1181 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1182 initrd for microcode blobs.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001183
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001184 In addition, you can build-in the microcode into the kernel. For that you
1185 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1186 to the CONFIG_EXTRA_FIRMWARE config option.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001187
Peter Oruba8d86f392008-07-28 18:44:21 +02001188config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001189 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001190 depends on MICROCODE
1191 default MICROCODE
1192 select FW_LOADER
1193 ---help---
1194 This options enables microcode patch loading support for Intel
1195 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001196
Alanb8989db2014-01-20 18:01:56 +00001197 For the current Intel microcode data package go to
1198 <https://downloadcenter.intel.com> and search for
1199 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001200
Peter Oruba80cc9f12008-07-28 18:44:22 +02001201config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001202 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001203 depends on MICROCODE
1204 select FW_LOADER
1205 ---help---
1206 If you select this option, microcode patch loading support for AMD
1207 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001208
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001209config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001210 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001211 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001212
Huang Ruic7ab62b2016-03-09 13:45:06 +08001213config PERF_EVENTS_AMD_POWER
1214 depends on PERF_EVENTS && CPU_SUP_AMD
1215 tristate "AMD Processor Power Reporting Mechanism"
1216 ---help---
1217 Provide power reporting mechanism support for AMD processors.
1218 Currently, it leverages X86_FEATURE_ACC_POWER
1219 (CPUID Fn8000_0007_EDX[12]) interface to calculate the
1220 average power consumption on Family 15h processors.
1221
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001222config X86_MSR
1223 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001224 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001225 This device gives privileged processes access to the x86
1226 Model-Specific Registers (MSRs). It is a character device with
1227 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1228 MSR accesses are directed to a specific CPU on multi-processor
1229 systems.
1230
1231config X86_CPUID
1232 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001233 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001234 This device gives processes access to the x86 CPUID instruction to
1235 be executed on a specific processor. It is a character device
1236 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1237 /dev/cpu/31/cpuid.
1238
1239choice
1240 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001241 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001242 depends on X86_32
1243
1244config NOHIGHMEM
1245 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001246 ---help---
1247 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1248 However, the address space of 32-bit x86 processors is only 4
1249 Gigabytes large. That means that, if you have a large amount of
1250 physical memory, not all of it can be "permanently mapped" by the
1251 kernel. The physical memory that's not permanently mapped is called
1252 "high memory".
1253
1254 If you are compiling a kernel which will never run on a machine with
1255 more than 1 Gigabyte total physical RAM, answer "off" here (default
1256 choice and suitable for most users). This will result in a "3GB/1GB"
1257 split: 3GB are mapped so that each process sees a 3GB virtual memory
1258 space and the remaining part of the 4GB virtual memory space is used
1259 by the kernel to permanently map as much physical memory as
1260 possible.
1261
1262 If the machine has between 1 and 4 Gigabytes physical RAM, then
1263 answer "4GB" here.
1264
1265 If more than 4 Gigabytes is used then answer "64GB" here. This
1266 selection turns Intel PAE (Physical Address Extension) mode on.
1267 PAE implements 3-level paging on IA32 processors. PAE is fully
1268 supported by Linux, PAE mode is implemented on all recent Intel
1269 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1270 then the kernel will not boot on CPUs that don't support PAE!
1271
1272 The actual amount of total physical memory will either be
1273 auto detected or can be forced by using a kernel command line option
1274 such as "mem=256M". (Try "man bootparam" or see the documentation of
1275 your boot loader (lilo or loadlin) about how to pass options to the
1276 kernel at boot time.)
1277
1278 If unsure, say "off".
1279
1280config HIGHMEM4G
1281 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001282 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001283 Select this if you have a 32-bit processor and between 1 and 4
1284 gigabytes of physical RAM.
1285
1286config HIGHMEM64G
1287 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001288 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001289 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001290 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001291 Select this if you have a 32-bit processor and more than 4
1292 gigabytes of physical RAM.
1293
1294endchoice
1295
1296choice
David Rientjes6a108a12011-01-20 14:44:16 -08001297 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001298 default VMSPLIT_3G
1299 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001300 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001301 Select the desired split between kernel and user memory.
1302
1303 If the address range available to the kernel is less than the
1304 physical memory installed, the remaining memory will be available
1305 as "high memory". Accessing high memory is a little more costly
1306 than low memory, as it needs to be mapped into the kernel first.
1307 Note that increasing the kernel address space limits the range
1308 available to user programs, making the address space there
1309 tighter. Selecting anything other than the default 3G/1G split
1310 will also likely make your kernel incompatible with binary-only
1311 kernel modules.
1312
1313 If you are not absolutely sure what you are doing, leave this
1314 option alone!
1315
1316 config VMSPLIT_3G
1317 bool "3G/1G user/kernel split"
1318 config VMSPLIT_3G_OPT
1319 depends on !X86_PAE
1320 bool "3G/1G user/kernel split (for full 1G low memory)"
1321 config VMSPLIT_2G
1322 bool "2G/2G user/kernel split"
1323 config VMSPLIT_2G_OPT
1324 depends on !X86_PAE
1325 bool "2G/2G user/kernel split (for full 2G low memory)"
1326 config VMSPLIT_1G
1327 bool "1G/3G user/kernel split"
1328endchoice
1329
1330config PAGE_OFFSET
1331 hex
1332 default 0xB0000000 if VMSPLIT_3G_OPT
1333 default 0x80000000 if VMSPLIT_2G
1334 default 0x78000000 if VMSPLIT_2G_OPT
1335 default 0x40000000 if VMSPLIT_1G
1336 default 0xC0000000
1337 depends on X86_32
1338
1339config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001340 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001341 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001342
1343config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001344 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001345 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001346 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001347 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001348 PAE is required for NX support, and furthermore enables
1349 larger swapspace support for non-overcommit purposes. It
1350 has the cost of more pagetable lookup overhead, and also
1351 consumes more pagetable space per process.
1352
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001353config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001354 def_bool y
1355 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001356
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001357config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001358 def_bool y
1359 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001360
Ingo Molnar10971ab2015-03-05 08:18:23 +01001361config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001362 def_bool y
1363 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001364 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001365 Certain kernel features effectively disable kernel
1366 linear 1 GB mappings (even if the CPU otherwise
1367 supports them), so don't confuse the user by printing
1368 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001369
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001370# Common NUMA Features
1371config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001372 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001373 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001374 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1375 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001376 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001377 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001378
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001379 The kernel will try to allocate memory used by a CPU on the
1380 local memory controller of the CPU and add some more
1381 NUMA awareness to the kernel.
1382
Ingo Molnarc280ea52008-11-08 13:29:45 +01001383 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001384 (or later), AMD Opteron, or EM64T NUMA.
1385
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001386 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001387 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001388
1389 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001390
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001391config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001392 def_bool y
1393 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001394 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001395 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001396 Enable AMD NUMA node topology detection. You should say Y here if
1397 you have a multi processor AMD system. This uses an old method to
1398 read the NUMA configuration directly from the builtin Northbridge
1399 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1400 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001401
1402config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001403 def_bool y
1404 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001405 depends on X86_64 && NUMA && ACPI && PCI
1406 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001407 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001408 Enable ACPI SRAT based node topology detection.
1409
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001410# Some NUMA nodes have memory ranges that span
1411# other nodes. Even though a pfn is valid and
1412# between a node's start and end pfns, it may not
1413# reside on that node. See memmap_init_zone()
1414# for details.
1415config NODES_SPAN_OTHER_NODES
1416 def_bool y
1417 depends on X86_64_ACPI_NUMA
1418
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001419config NUMA_EMU
1420 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001421 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001422 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001423 Enable NUMA emulation. A flat machine will be split
1424 into virtual nodes when booted with "numa=fake=N", where N is the
1425 number of nodes. This is only useful for debugging.
1426
1427config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001428 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001429 range 1 10
1430 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001431 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001432 default "3"
1433 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001434 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001435 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001436 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001437
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001438config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001439 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001440 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001441
1442config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001443 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001444 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001445
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001446config ARCH_FLATMEM_ENABLE
1447 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001448 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001449
1450config ARCH_DISCONTIGMEM_ENABLE
1451 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001452 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001453
1454config ARCH_DISCONTIGMEM_DEFAULT
1455 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001456 depends on NUMA && X86_32
1457
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001458config ARCH_SPARSEMEM_ENABLE
1459 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001460 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001461 select SPARSEMEM_STATIC if X86_32
1462 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1463
Tejun Heo3b166512011-04-01 11:15:12 +02001464config ARCH_SPARSEMEM_DEFAULT
1465 def_bool y
1466 depends on X86_64
1467
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001468config ARCH_SELECT_MEMORY_MODEL
1469 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001470 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001471
1472config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001473 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001474 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001475 help
1476 This option enables a sysfs memory/probe interface for testing.
1477 See Documentation/memory-hotplug.txt for more information.
1478 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001479
Tejun Heo3b166512011-04-01 11:15:12 +02001480config ARCH_PROC_KCORE_TEXT
1481 def_bool y
1482 depends on X86_64 && PROC_KCORE
1483
Avi Kivitya29815a2010-01-10 16:28:09 +02001484config ILLEGAL_POINTER_VALUE
1485 hex
1486 default 0 if X86_32
1487 default 0xdead000000000000 if X86_64
1488
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001489source "mm/Kconfig"
1490
Dan Williams7a678322015-08-19 00:34:34 -04001491config X86_PMEM_LEGACY_DEVICE
1492 bool
1493
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001494config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001495 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001496 depends on PHYS_ADDR_T_64BIT
1497 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001498 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001499 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001500 help
1501 Treat memory marked using the non-standard e820 type of 12 as used
1502 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1503 The kernel will offer these regions to the 'pmem' driver so
1504 they can be used for persistent storage.
1505
1506 Say Y if unsure.
1507
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001508config HIGHPTE
1509 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001510 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001511 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001512 The VM uses one page table entry for each page of physical memory.
1513 For systems with a lot of RAM, this can be wasteful of precious
1514 low memory. Setting this option will put user-space page table
1515 entries in high memory.
1516
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001517config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001518 bool "Check for low memory corruption"
1519 ---help---
1520 Periodically check for memory corruption in low memory, which
1521 is suspected to be caused by BIOS. Even when enabled in the
1522 configuration, it is disabled at runtime. Enable it by
1523 setting "memory_corruption_check=1" on the kernel command
1524 line. By default it scans the low 64k of memory every 60
1525 seconds; see the memory_corruption_check_size and
1526 memory_corruption_check_period parameters in
1527 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001528
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001529 When enabled with the default parameters, this option has
1530 almost no overhead, as it reserves a relatively small amount
1531 of memory and scans it infrequently. It both detects corruption
1532 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001533
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001534 It is, however, intended as a diagnostic tool; if repeatable
1535 BIOS-originated corruption always affects the same memory,
1536 you can use memmap= to prevent the kernel from using that
1537 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001538
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001539config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001540 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001541 depends on X86_CHECK_BIOS_CORRUPTION
1542 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001543 ---help---
1544 Set whether the default state of memory_corruption_check is
1545 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001546
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001547config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001548 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1549 default 64
1550 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001551 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001552 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001553
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001554 The first page contains BIOS data structures that the kernel
1555 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001556
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001557 By default we reserve the first 64K of physical RAM, as a
1558 number of BIOSes are known to corrupt that memory range
1559 during events such as suspend/resume or monitor cable
1560 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001561
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001562 You can set this to 4 if you are absolutely sure that you
1563 trust the BIOS to get all its memory reservations and usages
1564 right. If you know your BIOS have problems beyond the
1565 default 64K area, you can set this to 640 to avoid using the
1566 entire low memory range.
1567
1568 If you have doubts about the BIOS (e.g. suspend/resume does
1569 not work or there's kernel crashes after certain hardware
1570 hotplug events) then you might want to enable
1571 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1572 typical corruption patterns.
1573
1574 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001575
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001576config MATH_EMULATION
1577 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001578 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001579 prompt "Math emulation" if X86_32
1580 ---help---
1581 Linux can emulate a math coprocessor (used for floating point
1582 operations) if you don't have one. 486DX and Pentium processors have
1583 a math coprocessor built in, 486SX and 386 do not, unless you added
1584 a 487DX or 387, respectively. (The messages during boot time can
1585 give you some hints here ["man dmesg"].) Everyone needs either a
1586 coprocessor or this emulation.
1587
1588 If you don't have a math coprocessor, you need to say Y here; if you
1589 say Y here even though you have a coprocessor, the coprocessor will
1590 be used nevertheless. (This behavior can be changed with the kernel
1591 command line option "no387", which comes handy if your coprocessor
1592 is broken. Try "man bootparam" or see the documentation of your boot
1593 loader (lilo or loadlin) about how to pass options to the kernel at
1594 boot time.) This means that it is a good idea to say Y here if you
1595 intend to use this kernel on different machines.
1596
1597 More information about the internals of the Linux math coprocessor
1598 emulation can be found in <file:arch/x86/math-emu/README>.
1599
1600 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1601 kernel, it won't hurt.
1602
1603config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001604 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001605 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001606 ---help---
1607 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1608 the Memory Type Range Registers (MTRRs) may be used to control
1609 processor access to memory ranges. This is most useful if you have
1610 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1611 allows bus write transfers to be combined into a larger transfer
1612 before bursting over the PCI/AGP bus. This can increase performance
1613 of image write operations 2.5 times or more. Saying Y here creates a
1614 /proc/mtrr file which may be used to manipulate your processor's
1615 MTRRs. Typically the X server should use this.
1616
1617 This code has a reasonably generic interface so that similar
1618 control registers on other processors can be easily supported
1619 as well:
1620
1621 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1622 Registers (ARRs) which provide a similar functionality to MTRRs. For
1623 these, the ARRs are used to emulate the MTRRs.
1624 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1625 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1626 write-combining. All of these processors are supported by this code
1627 and it makes sense to say Y here if you have one of them.
1628
1629 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1630 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1631 can lead to all sorts of problems, so it's good to say Y here.
1632
1633 You can safely say Y even if your machine doesn't have MTRRs, you'll
1634 just add about 9 KB to your kernel.
1635
Randy Dunlap7225e752008-07-26 17:54:22 -07001636 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001637
Yinghai Lu95ffa242008-04-29 03:52:33 -07001638config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001639 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001640 prompt "MTRR cleanup support"
1641 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001642 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001643 Convert MTRR layout from continuous to discrete, so X drivers can
1644 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001645
Thomas Gleixneraba37282008-07-15 14:48:48 +02001646 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001647 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001648 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001649
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001650 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001651
1652config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001653 int "MTRR cleanup enable value (0-1)"
1654 range 0 1
1655 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001656 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001657 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001658 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001659
Yinghai Lu12031a62008-05-02 02:40:22 -07001660config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1661 int "MTRR cleanup spare reg num (0-7)"
1662 range 0 7
1663 default "1"
1664 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001665 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001666 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001667 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001668
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001669config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001670 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001671 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001672 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001673 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001674 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001675
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001676 PATs are the modern equivalents of MTRRs and are much more
1677 flexible than MTRRs.
1678
1679 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001680 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001681
1682 If unsure, say Y.
1683
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001684config ARCH_USES_PG_UNCACHED
1685 def_bool y
1686 depends on X86_PAT
1687
H. Peter Anvin628c6242011-07-31 13:59:29 -07001688config ARCH_RANDOM
1689 def_bool y
1690 prompt "x86 architectural random number generator" if EXPERT
1691 ---help---
1692 Enable the x86 architectural RDRAND instruction
1693 (Intel Bull Mountain technology) to generate random numbers.
1694 If supported, this is a high bandwidth, cryptographically
1695 secure hardware random number generator.
1696
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001697config X86_SMAP
1698 def_bool y
1699 prompt "Supervisor Mode Access Prevention" if EXPERT
1700 ---help---
1701 Supervisor Mode Access Prevention (SMAP) is a security
1702 feature in newer Intel processors. There is a small
1703 performance cost if this enabled and turned on; there is
1704 also a small increase in the kernel size if this is enabled.
1705
1706 If unsure, say Y.
1707
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001708config X86_INTEL_MPX
1709 prompt "Intel MPX (Memory Protection Extensions)"
1710 def_bool n
1711 depends on CPU_SUP_INTEL
1712 ---help---
1713 MPX provides hardware features that can be used in
1714 conjunction with compiler-instrumented code to check
1715 memory references. It is designed to detect buffer
1716 overflow or underflow bugs.
1717
1718 This option enables running applications which are
1719 instrumented or otherwise use MPX. It does not use MPX
1720 itself inside the kernel or to protect the kernel
1721 against bad memory references.
1722
1723 Enabling this option will make the kernel larger:
1724 ~8k of kernel text and 36 bytes of data on a 64-bit
1725 defconfig. It adds a long to the 'mm_struct' which
1726 will increase the kernel memory overhead of each
1727 process and adds some branches to paths used during
1728 exec() and munmap().
1729
1730 For details, see Documentation/x86/intel_mpx.txt
1731
1732 If unsure, say N.
1733
Dave Hansen35e97792016-02-12 13:02:00 -08001734config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001735 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001736 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001737 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001738 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001739 ---help---
1740 Memory Protection Keys provides a mechanism for enforcing
1741 page-based protections, but without requiring modification of the
1742 page tables when an application changes protection domains.
1743
1744 For details, see Documentation/x86/protection-keys.txt
1745
1746 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001747
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001748config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001749 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001750 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001751 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001752 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001753 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001754 This enables the kernel to use EFI runtime services that are
1755 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001756
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001757 This option is only useful on systems that have EFI firmware.
1758 In addition, you should use the latest ELILO loader available
1759 at <http://elilo.sourceforge.net> in order to take advantage
1760 of EFI runtime services. However, even with this option, the
1761 resultant kernel should continue to boot on existing non-EFI
1762 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001763
Matt Fleming291f3632011-12-12 21:27:52 +00001764config EFI_STUB
1765 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001766 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001767 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001768 ---help---
1769 This kernel feature allows a bzImage to be loaded directly
1770 by EFI firmware without the use of a bootloader.
1771
Roy Franz4172fe22013-09-22 15:45:25 -07001772 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001773
Matt Fleming7d453ee2014-01-10 18:52:06 +00001774config EFI_MIXED
1775 bool "EFI mixed-mode support"
1776 depends on EFI_STUB && X86_64
1777 ---help---
1778 Enabling this feature allows a 64-bit kernel to be booted
1779 on a 32-bit firmware, provided that your CPU supports 64-bit
1780 mode.
1781
1782 Note that it is not possible to boot a mixed-mode enabled
1783 kernel via the EFI boot stub - a bootloader that supports
1784 the EFI handover protocol must be used.
1785
1786 If unsure, say N.
1787
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001788config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001789 def_bool y
1790 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001791 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001792 This kernel feature is useful for number crunching applications
1793 that may need to compute untrusted bytecode during their
1794 execution. By using pipes or other transports made available to
1795 the process as file descriptors supporting the read/write
1796 syscalls, it's possible to isolate those applications in
1797 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001798 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001799 and the task is only allowed to execute a few safe syscalls
1800 defined by each seccomp mode.
1801
1802 If unsure, say Y. Only embedded should say N here.
1803
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001804source kernel/Kconfig.hz
1805
1806config KEXEC
1807 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001808 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001809 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001810 kexec is a system call that implements the ability to shutdown your
1811 current kernel, and to start another kernel. It is like a reboot
1812 but it is independent of the system firmware. And like a reboot
1813 you can start any kernel with it, not just Linux.
1814
1815 The name comes from the similarity to the exec system call.
1816
1817 It is an ongoing process to be certain the hardware in a machine
1818 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001819 initially work for you. As of this writing the exact hardware
1820 interface is strongly in flux, so no good recommendation can be
1821 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001822
Vivek Goyal74ca3172014-08-29 15:18:46 -07001823config KEXEC_FILE
1824 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001825 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001826 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001827 depends on X86_64
1828 depends on CRYPTO=y
1829 depends on CRYPTO_SHA256=y
1830 ---help---
1831 This is new version of kexec system call. This system call is
1832 file based and takes file descriptors as system call argument
1833 for kernel and initramfs as opposed to list of segments as
1834 accepted by previous system call.
1835
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001836config KEXEC_VERIFY_SIG
1837 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001838 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001839 ---help---
1840 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001841 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001842
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001843 In addition to that option, you need to enable signature
1844 verification for the corresponding kernel image type being
1845 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001846
1847config KEXEC_BZIMAGE_VERIFY_SIG
1848 bool "Enable bzImage signature verification support"
1849 depends on KEXEC_VERIFY_SIG
1850 depends on SIGNED_PE_FILE_VERIFICATION
1851 select SYSTEM_TRUSTED_KEYRING
1852 ---help---
1853 Enable bzImage signature verification support.
1854
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001855config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001856 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001857 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001858 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001859 Generate crash dump after being started by kexec.
1860 This should be normally only set in special crash dump kernels
1861 which are loaded in the main kernel with kexec-tools into
1862 a specially reserved region and then later executed after
1863 a crash by kdump/kexec. The crash dump kernel must be compiled
1864 to a memory address not used by the main kernel or BIOS using
1865 PHYSICAL_START, or it must be built as a relocatable image
1866 (CONFIG_RELOCATABLE=y).
1867 For more details see Documentation/kdump/kdump.txt
1868
Huang Ying3ab83522008-07-25 19:45:07 -07001869config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001870 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001871 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001872 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001873 Jump between original kernel and kexeced kernel and invoke
1874 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001875
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001876config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001877 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001878 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001879 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001880 This gives the physical address where the kernel is loaded.
1881
1882 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1883 bzImage will decompress itself to above physical address and
1884 run from there. Otherwise, bzImage will run from the address where
1885 it has been loaded by the boot loader and will ignore above physical
1886 address.
1887
1888 In normal kdump cases one does not have to set/change this option
1889 as now bzImage can be compiled as a completely relocatable image
1890 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1891 address. This option is mainly useful for the folks who don't want
1892 to use a bzImage for capturing the crash dump and want to use a
1893 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1894 to be specifically compiled to run from a specific memory area
1895 (normally a reserved region) and this option comes handy.
1896
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001897 So if you are using bzImage for capturing the crash dump,
1898 leave the value here unchanged to 0x1000000 and set
1899 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1900 for capturing the crash dump change this value to start of
1901 the reserved region. In other words, it can be set based on
1902 the "X" value as specified in the "crashkernel=YM@XM"
1903 command line boot parameter passed to the panic-ed
1904 kernel. Please take a look at Documentation/kdump/kdump.txt
1905 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001906
1907 Usage of bzImage for capturing the crash dump is recommended as
1908 one does not have to build two kernels. Same kernel can be used
1909 as production kernel and capture kernel. Above option should have
1910 gone away after relocatable bzImage support is introduced. But it
1911 is present because there are users out there who continue to use
1912 vmlinux for dump capture. This option should go away down the
1913 line.
1914
1915 Don't change this unless you know what you are doing.
1916
1917config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001918 bool "Build a relocatable kernel"
1919 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001920 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001921 This builds a kernel image that retains relocation information
1922 so it can be loaded someplace besides the default 1MB.
1923 The relocations tend to make the kernel binary about 10% larger,
1924 but are discarded at runtime.
1925
1926 One use is for the kexec on panic case where the recovery kernel
1927 must live at a different physical address than the primary
1928 kernel.
1929
1930 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1931 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001932 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001933
Kees Cook8ab38202013-10-10 17:18:14 -07001934config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07001935 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07001936 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001937 default n
1938 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07001939 In support of Kernel Address Space Layout Randomization (KASLR),
1940 this randomizes the physical address at which the kernel image
1941 is decompressed and the virtual address where the kernel
1942 image is mapped, as a security feature that deters exploit
1943 attempts relying on knowledge of the location of kernel
1944 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07001945
Baoquan Hee8581e32016-04-20 13:55:43 -07001946 The kernel physical and virtual address can be randomized
1947 from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
1948 using RANDOMIZE_BASE reduces the memory space available to
1949 kernel modules from 1.5GB to 1GB.)
Kees Cook8ab38202013-10-10 17:18:14 -07001950
Baoquan Hee8581e32016-04-20 13:55:43 -07001951 Entropy is generated using the RDRAND instruction if it is
1952 supported. If RDTSC is supported, its value is mixed into
1953 the entropy pool as well. If neither RDRAND nor RDTSC are
1954 supported, then entropy is read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001955
Baoquan Hee8581e32016-04-20 13:55:43 -07001956 Since the kernel is built using 2GB addressing, and
1957 PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
1958 entropy is theoretically possible. Currently, with the
1959 default value for PHYSICAL_ALIGN and due to page table
1960 layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
Kees Cookda2b6fb2013-12-10 12:27:45 -08001961
Baoquan Hee8581e32016-04-20 13:55:43 -07001962 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1963 time. To enable it, boot with "kaslr" on the kernel command
1964 line (which will also disable hibernation).
Kees Cook6145cfe2013-10-10 17:18:18 -07001965
Baoquan Hee8581e32016-04-20 13:55:43 -07001966 If unsure, say N.
Kees Cook8ab38202013-10-10 17:18:14 -07001967
1968# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001969config X86_NEED_RELOCS
1970 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001971 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001972
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001973config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001974 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001975 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001976 range 0x2000 0x1000000 if X86_32
1977 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001978 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001979 This value puts the alignment restrictions on physical address
1980 where kernel is loaded and run from. Kernel is compiled for an
1981 address which meets above alignment restriction.
1982
1983 If bootloader loads the kernel at a non-aligned address and
1984 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1985 address aligned to above value and run from there.
1986
1987 If bootloader loads the kernel at a non-aligned address and
1988 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1989 load address and decompress itself to the address it has been
1990 compiled for and run from there. The address for which kernel is
1991 compiled already meets above alignment restrictions. Hence the
1992 end result is that kernel runs from a physical address meeting
1993 above alignment restrictions.
1994
Kees Cooka0215062013-07-08 09:15:17 -07001995 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1996 this value must be a multiple of 0x200000.
1997
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001998 Don't change this unless you know what you are doing.
1999
2000config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05002001 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10002002 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002003 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05002004 Say Y here to allow turning CPUs off and on. CPUs can be
2005 controlled through /sys/devices/system/cpu.
2006 ( Note: power management support will enable this option
2007 automatically on SMP systems. )
2008 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002009
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002010config BOOTPARAM_HOTPLUG_CPU0
2011 bool "Set default setting of cpu0_hotpluggable"
2012 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002013 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002014 ---help---
2015 Set whether default state of cpu0_hotpluggable is on or off.
2016
2017 Say Y here to enable CPU0 hotplug by default. If this switch
2018 is turned on, there is no need to give cpu0_hotplug kernel
2019 parameter and the CPU0 hotplug feature is enabled by default.
2020
2021 Please note: there are two known CPU0 dependencies if you want
2022 to enable the CPU0 hotplug feature either by this switch or by
2023 cpu0_hotplug kernel parameter.
2024
2025 First, resume from hibernate or suspend always starts from CPU0.
2026 So hibernate and suspend are prevented if CPU0 is offline.
2027
2028 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2029 offline if any interrupt can not migrate out of CPU0. There may
2030 be other CPU0 dependencies.
2031
2032 Please make sure the dependencies are under your control before
2033 you enable this feature.
2034
2035 Say N if you don't want to enable CPU0 hotplug feature by default.
2036 You still can enable the CPU0 hotplug feature at boot by kernel
2037 parameter cpu0_hotplug.
2038
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002039config DEBUG_HOTPLUG_CPU0
2040 def_bool n
2041 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002042 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002043 ---help---
2044 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2045 soon as possible and boots up userspace with CPU0 offlined. User
2046 can online CPU0 back after boot time.
2047
2048 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2049 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2050 compilation or giving cpu0_hotplug kernel parameter at boot.
2051
2052 If unsure, say N.
2053
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002054config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002055 def_bool n
2056 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002057 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002058 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002059 Certain buggy versions of glibc will crash if they are
2060 presented with a 32-bit vDSO that is not mapped at the address
2061 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002062
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002063 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2064 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2065 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2066 the only released version with the bug, but OpenSUSE 9
2067 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002068
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002069 The symptom of the bug is that everything crashes on startup, saying:
2070 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2071
2072 Saying Y here changes the default value of the vdso32 boot
2073 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2074 This works around the glibc bug but hurts performance.
2075
2076 If unsure, say N: if you are compiling your own kernel, you
2077 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002078
Kees Cook3dc33bd2015-08-12 17:55:19 -07002079choice
2080 prompt "vsyscall table for legacy applications"
2081 depends on X86_64
2082 default LEGACY_VSYSCALL_EMULATE
2083 help
2084 Legacy user code that does not know how to find the vDSO expects
2085 to be able to issue three syscalls by calling fixed addresses in
2086 kernel space. Since this location is not randomized with ASLR,
2087 it can be used to assist security vulnerability exploitation.
2088
2089 This setting can be changed at boot time via the kernel command
2090 line parameter vsyscall=[native|emulate|none].
2091
2092 On a system with recent enough glibc (2.14 or newer) and no
2093 static binaries, you can say None without a performance penalty
2094 to improve security.
2095
2096 If unsure, select "Emulate".
2097
2098 config LEGACY_VSYSCALL_NATIVE
2099 bool "Native"
2100 help
2101 Actual executable code is located in the fixed vsyscall
2102 address mapping, implementing time() efficiently. Since
2103 this makes the mapping executable, it can be used during
2104 security vulnerability exploitation (traditionally as
2105 ROP gadgets). This configuration is not recommended.
2106
2107 config LEGACY_VSYSCALL_EMULATE
2108 bool "Emulate"
2109 help
2110 The kernel traps and emulates calls into the fixed
2111 vsyscall address mapping. This makes the mapping
2112 non-executable, but it still contains known contents,
2113 which could be used in certain rare security vulnerability
2114 exploits. This configuration is recommended when userspace
2115 still uses the vsyscall area.
2116
2117 config LEGACY_VSYSCALL_NONE
2118 bool "None"
2119 help
2120 There will be no vsyscall mapping at all. This will
2121 eliminate any risk of ASLR bypass due to the vsyscall
2122 fixed address mapping. Attempts to use the vsyscalls
2123 will be reported to dmesg, so that either old or
2124 malicious userspace programs can be identified.
2125
2126endchoice
2127
Tim Bird516cbf32008-08-12 12:52:36 -07002128config CMDLINE_BOOL
2129 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002130 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002131 Allow for specifying boot arguments to the kernel at
2132 build time. On some systems (e.g. embedded ones), it is
2133 necessary or convenient to provide some or all of the
2134 kernel boot arguments with the kernel itself (that is,
2135 to not rely on the boot loader to provide them.)
2136
2137 To compile command line arguments into the kernel,
2138 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002139 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002140
2141 Systems with fully functional boot loaders (i.e. non-embedded)
2142 should leave this option set to 'N'.
2143
2144config CMDLINE
2145 string "Built-in kernel command string"
2146 depends on CMDLINE_BOOL
2147 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002148 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002149 Enter arguments here that should be compiled into the kernel
2150 image and used at boot time. If the boot loader provides a
2151 command line at boot time, it is appended to this string to
2152 form the full kernel command line, when the system boots.
2153
2154 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2155 change this behavior.
2156
2157 In most cases, the command line (whether built-in or provided
2158 by the boot loader) should specify the device for the root
2159 file system.
2160
2161config CMDLINE_OVERRIDE
2162 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002163 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002164 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002165 Set this option to 'Y' to have the kernel ignore the boot loader
2166 command line, and use ONLY the built-in command line.
2167
2168 This is used to work around broken boot loaders. This should
2169 be set to 'N' under normal conditions.
2170
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002171config MODIFY_LDT_SYSCALL
2172 bool "Enable the LDT (local descriptor table)" if EXPERT
2173 default y
2174 ---help---
2175 Linux can allow user programs to install a per-process x86
2176 Local Descriptor Table (LDT) using the modify_ldt(2) system
2177 call. This is required to run 16-bit or segmented code such as
2178 DOSEMU or some Wine programs. It is also used by some very old
2179 threading libraries.
2180
2181 Enabling this feature adds a small amount of overhead to
2182 context switches and increases the low-level kernel attack
2183 surface. Disabling it removes the modify_ldt(2) system call.
2184
2185 Saying 'N' here may make sense for embedded or server kernels.
2186
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002187source "kernel/livepatch/Kconfig"
2188
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002189endmenu
2190
2191config ARCH_ENABLE_MEMORY_HOTPLUG
2192 def_bool y
2193 depends on X86_64 || (X86_32 && HIGHMEM)
2194
Gary Hade35551052008-10-31 10:52:03 -07002195config ARCH_ENABLE_MEMORY_HOTREMOVE
2196 def_bool y
2197 depends on MEMORY_HOTPLUG
2198
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002199config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002200 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002201 depends on NUMA
2202
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002203config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2204 def_bool y
2205 depends on X86_64 || X86_PAE
2206
Naoya Horiguchic177c812014-06-04 16:05:35 -07002207config ARCH_ENABLE_HUGEPAGE_MIGRATION
2208 def_bool y
2209 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2210
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002211menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002212
2213config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002214 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002215 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002216
2217source "kernel/power/Kconfig"
2218
2219source "drivers/acpi/Kconfig"
2220
Feng Tangefafc8b2009-08-14 15:23:29 -04002221source "drivers/sfi/Kconfig"
2222
Andi Kleena6b68072008-01-30 13:32:49 +01002223config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002224 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002225 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002226
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002227menuconfig APM
2228 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002229 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002230 ---help---
2231 APM is a BIOS specification for saving power using several different
2232 techniques. This is mostly useful for battery powered laptops with
2233 APM compliant BIOSes. If you say Y here, the system time will be
2234 reset after a RESUME operation, the /proc/apm device will provide
2235 battery status information, and user-space programs will receive
2236 notification of APM "events" (e.g. battery status change).
2237
2238 If you select "Y" here, you can disable actual use of the APM
2239 BIOS by passing the "apm=off" option to the kernel at boot time.
2240
2241 Note that the APM support is almost completely disabled for
2242 machines with more than one CPU.
2243
2244 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002245 and more information, read <file:Documentation/power/apm-acpi.txt>
2246 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002247 <http://www.tldp.org/docs.html#howto>.
2248
2249 This driver does not spin down disk drives (see the hdparm(8)
2250 manpage ("man 8 hdparm") for that), and it doesn't turn off
2251 VESA-compliant "green" monitors.
2252
2253 This driver does not support the TI 4000M TravelMate and the ACER
2254 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2255 desktop machines also don't have compliant BIOSes, and this driver
2256 may cause those machines to panic during the boot phase.
2257
2258 Generally, if you don't have a battery in your machine, there isn't
2259 much point in using this driver and you should say N. If you get
2260 random kernel OOPSes or reboots that don't seem to be related to
2261 anything, try disabling/enabling this option (or disabling/enabling
2262 APM in your BIOS).
2263
2264 Some other things you should try when experiencing seemingly random,
2265 "weird" problems:
2266
2267 1) make sure that you have enough swap space and that it is
2268 enabled.
2269 2) pass the "no-hlt" option to the kernel
2270 3) switch on floating point emulation in the kernel and pass
2271 the "no387" option to the kernel
2272 4) pass the "floppy=nodma" option to the kernel
2273 5) pass the "mem=4M" option to the kernel (thereby disabling
2274 all but the first 4 MB of RAM)
2275 6) make sure that the CPU is not over clocked.
2276 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2277 8) disable the cache from your BIOS settings
2278 9) install a fan for the video card or exchange video RAM
2279 10) install a better fan for the CPU
2280 11) exchange RAM chips
2281 12) exchange the motherboard.
2282
2283 To compile this driver as a module, choose M here: the
2284 module will be called apm.
2285
2286if APM
2287
2288config APM_IGNORE_USER_SUSPEND
2289 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002290 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002291 This option will ignore USER SUSPEND requests. On machines with a
2292 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2293 series notebooks, it is necessary to say Y because of a BIOS bug.
2294
2295config APM_DO_ENABLE
2296 bool "Enable PM at boot time"
2297 ---help---
2298 Enable APM features at boot time. From page 36 of the APM BIOS
2299 specification: "When disabled, the APM BIOS does not automatically
2300 power manage devices, enter the Standby State, enter the Suspend
2301 State, or take power saving steps in response to CPU Idle calls."
2302 This driver will make CPU Idle calls when Linux is idle (unless this
2303 feature is turned off -- see "Do CPU IDLE calls", below). This
2304 should always save battery power, but more complicated APM features
2305 will be dependent on your BIOS implementation. You may need to turn
2306 this option off if your computer hangs at boot time when using APM
2307 support, or if it beeps continuously instead of suspending. Turn
2308 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2309 T400CDT. This is off by default since most machines do fine without
2310 this feature.
2311
2312config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002313 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002314 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002315 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002316 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2317 On some machines, this can activate improved power savings, such as
2318 a slowed CPU clock rate, when the machine is idle. These idle calls
2319 are made after the idle loop has run for some length of time (e.g.,
2320 333 mS). On some machines, this will cause a hang at boot time or
2321 whenever the CPU becomes idle. (On machines with more than one CPU,
2322 this option does nothing.)
2323
2324config APM_DISPLAY_BLANK
2325 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002326 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002327 Enable console blanking using the APM. Some laptops can use this to
2328 turn off the LCD backlight when the screen blanker of the Linux
2329 virtual console blanks the screen. Note that this is only used by
2330 the virtual console screen blanker, and won't turn off the backlight
2331 when using the X Window system. This also doesn't have anything to
2332 do with your VESA-compliant power-saving monitor. Further, this
2333 option doesn't work for all laptops -- it might not turn off your
2334 backlight at all, or it might print a lot of errors to the console,
2335 especially if you are using gpm.
2336
2337config APM_ALLOW_INTS
2338 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002339 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002340 Normally we disable external interrupts while we are making calls to
2341 the APM BIOS as a measure to lessen the effects of a badly behaving
2342 BIOS implementation. The BIOS should reenable interrupts if it
2343 needs to. Unfortunately, some BIOSes do not -- especially those in
2344 many of the newer IBM Thinkpads. If you experience hangs when you
2345 suspend, try setting this to Y. Otherwise, say N.
2346
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002347endif # APM
2348
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002349source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002350
2351source "drivers/cpuidle/Kconfig"
2352
Andy Henroid27471fd2008-10-09 11:45:22 -07002353source "drivers/idle/Kconfig"
2354
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002355endmenu
2356
2357
2358menu "Bus options (PCI etc.)"
2359
2360config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002361 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002362 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002363 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002364 Find out whether you have a PCI motherboard. PCI is the name of a
2365 bus system, i.e. the way the CPU talks to the other stuff inside
2366 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2367 VESA. If you have PCI, say Y, otherwise N.
2368
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002369choice
2370 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002371 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002372 default PCI_GOANY
2373 ---help---
2374 On PCI systems, the BIOS can be used to detect the PCI devices and
2375 determine their configuration. However, some old PCI motherboards
2376 have BIOS bugs and may crash if this is done. Also, some embedded
2377 PCI-based systems don't have any BIOS at all. Linux can also try to
2378 detect the PCI hardware directly without using the BIOS.
2379
2380 With this option, you can specify how Linux should detect the
2381 PCI devices. If you choose "BIOS", the BIOS will be used,
2382 if you choose "Direct", the BIOS won't be used, and if you
2383 choose "MMConfig", then PCI Express MMCONFIG will be used.
2384 If you choose "Any", the kernel will try MMCONFIG, then the
2385 direct access method and falls back to the BIOS if that doesn't
2386 work. If unsure, go with the default, which is "Any".
2387
2388config PCI_GOBIOS
2389 bool "BIOS"
2390
2391config PCI_GOMMCONFIG
2392 bool "MMConfig"
2393
2394config PCI_GODIRECT
2395 bool "Direct"
2396
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002397config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002398 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002399 depends on OLPC
2400
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002401config PCI_GOANY
2402 bool "Any"
2403
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002404endchoice
2405
2406config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002407 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002408 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002409
2410# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2411config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002412 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002413 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002414
2415config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002416 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002417 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002418
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002419config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002420 def_bool y
2421 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002422
Alex Nixonb5401a92010-03-18 16:31:34 -04002423config PCI_XEN
2424 def_bool y
2425 depends on PCI && XEN
2426 select SWIOTLB_XEN
2427
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002428config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002429 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002430 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002431
2432config PCI_MMCONFIG
2433 bool "Support mmconfig PCI config space access"
2434 depends on X86_64 && PCI && ACPI
2435
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002436config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002437 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002438 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002439 help
2440 Read the PCI windows out of the CNB20LE host bridge. This allows
2441 PCI hotplug to work on systems with the CNB20LE chipset which do
2442 not have ACPI.
2443
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002444 There's no public spec for this chipset, and this functionality
2445 is known to be incomplete.
2446
2447 You should say N unless you know you need this.
2448
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002449source "drivers/pci/Kconfig"
2450
David Rientjes1c00f012011-03-22 16:34:59 -07002451# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002452config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002453 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2454 default y
2455 help
2456 Enables ISA-style DMA support for devices requiring such controllers.
2457 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002458
2459if X86_32
2460
2461config ISA
2462 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002463 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002464 Find out whether you have ISA slots on your motherboard. ISA is the
2465 name of a bus system, i.e. the way the CPU talks to the other stuff
2466 inside your box. Other bus systems are PCI, EISA, MicroChannel
2467 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2468 newer boards don't support it. If you have ISA, say Y, otherwise N.
2469
2470config EISA
2471 bool "EISA support"
2472 depends on ISA
2473 ---help---
2474 The Extended Industry Standard Architecture (EISA) bus was
2475 developed as an open alternative to the IBM MicroChannel bus.
2476
2477 The EISA bus provided some of the features of the IBM MicroChannel
2478 bus while maintaining backward compatibility with cards made for
2479 the older ISA bus. The EISA bus saw limited use between 1988 and
2480 1995 when it was made obsolete by the PCI bus.
2481
2482 Say Y here if you are building a kernel for an EISA-based machine.
2483
2484 Otherwise, say N.
2485
2486source "drivers/eisa/Kconfig"
2487
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002488config SCx200
2489 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002490 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002491 This provides basic support for National Semiconductor's
2492 (now AMD's) Geode processors. The driver probes for the
2493 PCI-IDs of several on-chip devices, so its a good dependency
2494 for other scx200_* drivers.
2495
2496 If compiled as a module, the driver is named scx200.
2497
2498config SCx200HR_TIMER
2499 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002500 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002501 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002502 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002503 This driver provides a clocksource built upon the on-chip
2504 27MHz high-resolution timer. Its also a workaround for
2505 NSC Geode SC-1100's buggy TSC, which loses time when the
2506 processor goes idle (as is done by the scheduler). The
2507 other workaround is idle=poll boot option.
2508
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002509config OLPC
2510 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002511 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002512 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002513 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002514 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002515 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002516 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002517 Add support for detecting the unique features of the OLPC
2518 XO hardware.
2519
Daniel Drakea3128582011-06-25 17:34:10 +01002520config OLPC_XO1_PM
2521 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002522 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002523 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002524 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002525 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002526
Daniel Drakecfee9592011-06-25 17:34:17 +01002527config OLPC_XO1_RTC
2528 bool "OLPC XO-1 Real Time Clock"
2529 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2530 ---help---
2531 Add support for the XO-1 real time clock, which can be used as a
2532 programmable wakeup source.
2533
Daniel Drake7feda8e2011-06-25 17:34:12 +01002534config OLPC_XO1_SCI
2535 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002536 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002537 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002538 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002539 select GPIO_CS5535
2540 select MFD_CORE
2541 ---help---
2542 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002543 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002544 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002545 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002546 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002547 - AC adapter status updates
2548 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002549
Daniel Drakea0f30f52011-06-25 17:34:18 +01002550config OLPC_XO15_SCI
2551 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002552 depends on OLPC && ACPI
2553 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002554 ---help---
2555 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2556 - EC-driven system wakeups
2557 - AC adapter status updates
2558 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002559
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002560config ALIX
2561 bool "PCEngines ALIX System Support (LED setup)"
2562 select GPIOLIB
2563 ---help---
2564 This option enables system support for the PCEngines ALIX.
2565 At present this just sets up LEDs for GPIO control on
2566 ALIX2/3/6 boards. However, other system specific setup should
2567 get added here.
2568
2569 Note: You must still enable the drivers for GPIO and LED support
2570 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2571
2572 Note: You have to set alix.force=1 for boards with Award BIOS.
2573
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002574config NET5501
2575 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2576 select GPIOLIB
2577 ---help---
2578 This option enables system support for the Soekris Engineering net5501.
2579
Philip A. Prindeville31970592012-01-14 01:45:39 -07002580config GEOS
2581 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2582 select GPIOLIB
2583 depends on DMI
2584 ---help---
2585 This option enables system support for the Traverse Technologies GEOS.
2586
Vivien Didelot7d029122013-01-04 16:18:14 -05002587config TS5500
2588 bool "Technologic Systems TS-5500 platform support"
2589 depends on MELAN
2590 select CHECK_SIGNATURE
2591 select NEW_LEDS
2592 select LEDS_CLASS
2593 ---help---
2594 This option enables system support for the Technologic Systems TS-5500.
2595
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002596endif # X86_32
2597
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002598config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002599 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002600 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002601
2602source "drivers/pcmcia/Kconfig"
2603
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002604config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002605 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002606 depends on PCI
2607 default n
2608 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002609 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002610 infrastructure code to support RapidIO interconnect devices.
2611
2612source "drivers/rapidio/Kconfig"
2613
David Herrmanne3263ab2013-08-02 14:05:22 +02002614config X86_SYSFB
2615 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2616 help
2617 Firmwares often provide initial graphics framebuffers so the BIOS,
2618 bootloader or kernel can show basic video-output during boot for
2619 user-guidance and debugging. Historically, x86 used the VESA BIOS
2620 Extensions and EFI-framebuffers for this, which are mostly limited
2621 to x86.
2622 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2623 framebuffers so the new generic system-framebuffer drivers can be
2624 used on x86. If the framebuffer is not compatible with the generic
2625 modes, it is adverticed as fallback platform framebuffer so legacy
2626 drivers like efifb, vesafb and uvesafb can pick it up.
2627 If this option is not selected, all system framebuffers are always
2628 marked as fallback platform framebuffers as usual.
2629
2630 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2631 not be able to pick up generic system framebuffers if this option
2632 is selected. You are highly encouraged to enable simplefb as
2633 replacement if you select this option. simplefb can correctly deal
2634 with generic system framebuffers. But you should still keep vesafb
2635 and others enabled as fallback if a system framebuffer is
2636 incompatible with simplefb.
2637
2638 If unsure, say Y.
2639
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002640endmenu
2641
2642
2643menu "Executable file formats / Emulations"
2644
2645source "fs/Kconfig.binfmt"
2646
2647config IA32_EMULATION
2648 bool "IA32 Emulation"
2649 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002650 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002651 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002652 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002653 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002654 Include code to run legacy 32-bit programs under a
2655 64-bit kernel. You should likely turn this on, unless you're
2656 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002657
2658config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002659 tristate "IA32 a.out support"
2660 depends on IA32_EMULATION
2661 ---help---
2662 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002663
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002664config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002665 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002666 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002667 ---help---
2668 Include code to run binaries for the x32 native 32-bit ABI
2669 for 64-bit processors. An x32 process gets access to the
2670 full 64-bit register file and wide data path while leaving
2671 pointers at 32 bits for smaller memory footprint.
2672
2673 You will need a recent binutils (2.22 or later) with
2674 elf32_x86_64 support enabled to compile a kernel with this
2675 option set.
2676
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002677config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002678 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002679 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002680
Jan Beulich3120e252012-09-10 12:41:45 +01002681if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002682config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002683 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002684
2685config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002686 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002687 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002688
David Howellsee009e4a02011-03-07 15:06:20 +00002689config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002690 def_bool y
2691 depends on KEYS
2692endif
David Howellsee009e4a02011-03-07 15:06:20 +00002693
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002694endmenu
2695
2696
Keith Packarde5beae12008-11-03 18:21:45 +01002697config HAVE_ATOMIC_IOMAP
2698 def_bool y
2699 depends on X86_32
2700
Alessandro Rubini4692d772012-04-04 19:39:58 +02002701config X86_DEV_DMA_OPS
2702 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002703 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002704
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002705config X86_DMA_REMAP
2706 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002707 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002708
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002709config PMC_ATOM
2710 def_bool y
2711 depends on PCI
2712
Keith Busch185a3832016-01-12 13:18:10 -07002713config VMD
2714 depends on PCI_MSI
2715 tristate "Volume Management Device Driver"
2716 default N
2717 ---help---
2718 Adds support for the Intel Volume Management Device (VMD). VMD is a
2719 secondary PCI host bridge that allows PCI Express root ports,
2720 and devices attached to them, to be removed from the default
2721 PCI domain and placed within the VMD domain. This provides
2722 more bus resources than are otherwise possible with a
2723 single domain. If you know your system provides one of these and
2724 has devices attached to it, say Y; if you are not sure, say N.
2725
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726source "net/Kconfig"
2727
2728source "drivers/Kconfig"
2729
2730source "drivers/firmware/Kconfig"
2731
2732source "fs/Kconfig"
2733
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002734source "arch/x86/Kconfig.debug"
2735
2736source "security/Kconfig"
2737
2738source "crypto/Kconfig"
2739
Avi Kivityedf88412007-12-16 11:02:48 +02002740source "arch/x86/kvm/Kconfig"
2741
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002742source "lib/Kconfig"