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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
1213config X86_MSR
1214 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001215 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001216 This device gives privileged processes access to the x86
1217 Model-Specific Registers (MSRs). It is a character device with
1218 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1219 MSR accesses are directed to a specific CPU on multi-processor
1220 systems.
1221
1222config X86_CPUID
1223 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001224 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001225 This device gives processes access to the x86 CPUID instruction to
1226 be executed on a specific processor. It is a character device
1227 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1228 /dev/cpu/31/cpuid.
1229
1230choice
1231 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001232 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001233 depends on X86_32
1234
1235config NOHIGHMEM
1236 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001237 ---help---
1238 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1239 However, the address space of 32-bit x86 processors is only 4
1240 Gigabytes large. That means that, if you have a large amount of
1241 physical memory, not all of it can be "permanently mapped" by the
1242 kernel. The physical memory that's not permanently mapped is called
1243 "high memory".
1244
1245 If you are compiling a kernel which will never run on a machine with
1246 more than 1 Gigabyte total physical RAM, answer "off" here (default
1247 choice and suitable for most users). This will result in a "3GB/1GB"
1248 split: 3GB are mapped so that each process sees a 3GB virtual memory
1249 space and the remaining part of the 4GB virtual memory space is used
1250 by the kernel to permanently map as much physical memory as
1251 possible.
1252
1253 If the machine has between 1 and 4 Gigabytes physical RAM, then
1254 answer "4GB" here.
1255
1256 If more than 4 Gigabytes is used then answer "64GB" here. This
1257 selection turns Intel PAE (Physical Address Extension) mode on.
1258 PAE implements 3-level paging on IA32 processors. PAE is fully
1259 supported by Linux, PAE mode is implemented on all recent Intel
1260 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1261 then the kernel will not boot on CPUs that don't support PAE!
1262
1263 The actual amount of total physical memory will either be
1264 auto detected or can be forced by using a kernel command line option
1265 such as "mem=256M". (Try "man bootparam" or see the documentation of
1266 your boot loader (lilo or loadlin) about how to pass options to the
1267 kernel at boot time.)
1268
1269 If unsure, say "off".
1270
1271config HIGHMEM4G
1272 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001273 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001274 Select this if you have a 32-bit processor and between 1 and 4
1275 gigabytes of physical RAM.
1276
1277config HIGHMEM64G
1278 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001279 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001280 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001281 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001282 Select this if you have a 32-bit processor and more than 4
1283 gigabytes of physical RAM.
1284
1285endchoice
1286
1287choice
David Rientjes6a108a12011-01-20 14:44:16 -08001288 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001289 default VMSPLIT_3G
1290 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001291 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001292 Select the desired split between kernel and user memory.
1293
1294 If the address range available to the kernel is less than the
1295 physical memory installed, the remaining memory will be available
1296 as "high memory". Accessing high memory is a little more costly
1297 than low memory, as it needs to be mapped into the kernel first.
1298 Note that increasing the kernel address space limits the range
1299 available to user programs, making the address space there
1300 tighter. Selecting anything other than the default 3G/1G split
1301 will also likely make your kernel incompatible with binary-only
1302 kernel modules.
1303
1304 If you are not absolutely sure what you are doing, leave this
1305 option alone!
1306
1307 config VMSPLIT_3G
1308 bool "3G/1G user/kernel split"
1309 config VMSPLIT_3G_OPT
1310 depends on !X86_PAE
1311 bool "3G/1G user/kernel split (for full 1G low memory)"
1312 config VMSPLIT_2G
1313 bool "2G/2G user/kernel split"
1314 config VMSPLIT_2G_OPT
1315 depends on !X86_PAE
1316 bool "2G/2G user/kernel split (for full 2G low memory)"
1317 config VMSPLIT_1G
1318 bool "1G/3G user/kernel split"
1319endchoice
1320
1321config PAGE_OFFSET
1322 hex
1323 default 0xB0000000 if VMSPLIT_3G_OPT
1324 default 0x80000000 if VMSPLIT_2G
1325 default 0x78000000 if VMSPLIT_2G_OPT
1326 default 0x40000000 if VMSPLIT_1G
1327 default 0xC0000000
1328 depends on X86_32
1329
1330config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001331 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001332 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001333
1334config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001335 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001336 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001337 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001338 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001339 PAE is required for NX support, and furthermore enables
1340 larger swapspace support for non-overcommit purposes. It
1341 has the cost of more pagetable lookup overhead, and also
1342 consumes more pagetable space per process.
1343
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001344config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001345 def_bool y
1346 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001347
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001348config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001349 def_bool y
1350 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001351
Ingo Molnar10971ab2015-03-05 08:18:23 +01001352config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001353 def_bool y
1354 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001355 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001356 Certain kernel features effectively disable kernel
1357 linear 1 GB mappings (even if the CPU otherwise
1358 supports them), so don't confuse the user by printing
1359 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001360
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001361# Common NUMA Features
1362config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001363 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001364 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001365 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1366 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001367 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001368 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001369
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001370 The kernel will try to allocate memory used by a CPU on the
1371 local memory controller of the CPU and add some more
1372 NUMA awareness to the kernel.
1373
Ingo Molnarc280ea52008-11-08 13:29:45 +01001374 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001375 (or later), AMD Opteron, or EM64T NUMA.
1376
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001377 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001378 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001379
1380 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001381
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001382config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001383 def_bool y
1384 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001385 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001386 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001387 Enable AMD NUMA node topology detection. You should say Y here if
1388 you have a multi processor AMD system. This uses an old method to
1389 read the NUMA configuration directly from the builtin Northbridge
1390 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1391 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001392
1393config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001394 def_bool y
1395 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001396 depends on X86_64 && NUMA && ACPI && PCI
1397 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001398 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001399 Enable ACPI SRAT based node topology detection.
1400
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001401# Some NUMA nodes have memory ranges that span
1402# other nodes. Even though a pfn is valid and
1403# between a node's start and end pfns, it may not
1404# reside on that node. See memmap_init_zone()
1405# for details.
1406config NODES_SPAN_OTHER_NODES
1407 def_bool y
1408 depends on X86_64_ACPI_NUMA
1409
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001410config NUMA_EMU
1411 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001412 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001413 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001414 Enable NUMA emulation. A flat machine will be split
1415 into virtual nodes when booted with "numa=fake=N", where N is the
1416 number of nodes. This is only useful for debugging.
1417
1418config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001419 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001420 range 1 10
1421 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001422 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001423 default "3"
1424 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001425 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001426 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001427 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001428
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001429config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001430 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001431 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001432
1433config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001434 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001435 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001436
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001437config ARCH_FLATMEM_ENABLE
1438 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001439 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001440
1441config ARCH_DISCONTIGMEM_ENABLE
1442 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001443 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001444
1445config ARCH_DISCONTIGMEM_DEFAULT
1446 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001447 depends on NUMA && X86_32
1448
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001449config ARCH_SPARSEMEM_ENABLE
1450 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001451 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001452 select SPARSEMEM_STATIC if X86_32
1453 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1454
Tejun Heo3b166512011-04-01 11:15:12 +02001455config ARCH_SPARSEMEM_DEFAULT
1456 def_bool y
1457 depends on X86_64
1458
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001459config ARCH_SELECT_MEMORY_MODEL
1460 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001461 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001462
1463config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001464 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001465 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001466 help
1467 This option enables a sysfs memory/probe interface for testing.
1468 See Documentation/memory-hotplug.txt for more information.
1469 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001470
Tejun Heo3b166512011-04-01 11:15:12 +02001471config ARCH_PROC_KCORE_TEXT
1472 def_bool y
1473 depends on X86_64 && PROC_KCORE
1474
Avi Kivitya29815a2010-01-10 16:28:09 +02001475config ILLEGAL_POINTER_VALUE
1476 hex
1477 default 0 if X86_32
1478 default 0xdead000000000000 if X86_64
1479
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001480source "mm/Kconfig"
1481
Dan Williams7a678322015-08-19 00:34:34 -04001482config X86_PMEM_LEGACY_DEVICE
1483 bool
1484
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001485config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001486 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001487 depends on PHYS_ADDR_T_64BIT
1488 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001489 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001490 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001491 help
1492 Treat memory marked using the non-standard e820 type of 12 as used
1493 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1494 The kernel will offer these regions to the 'pmem' driver so
1495 they can be used for persistent storage.
1496
1497 Say Y if unsure.
1498
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001499config HIGHPTE
1500 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001501 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001502 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001503 The VM uses one page table entry for each page of physical memory.
1504 For systems with a lot of RAM, this can be wasteful of precious
1505 low memory. Setting this option will put user-space page table
1506 entries in high memory.
1507
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001508config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001509 bool "Check for low memory corruption"
1510 ---help---
1511 Periodically check for memory corruption in low memory, which
1512 is suspected to be caused by BIOS. Even when enabled in the
1513 configuration, it is disabled at runtime. Enable it by
1514 setting "memory_corruption_check=1" on the kernel command
1515 line. By default it scans the low 64k of memory every 60
1516 seconds; see the memory_corruption_check_size and
1517 memory_corruption_check_period parameters in
1518 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001519
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001520 When enabled with the default parameters, this option has
1521 almost no overhead, as it reserves a relatively small amount
1522 of memory and scans it infrequently. It both detects corruption
1523 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001524
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001525 It is, however, intended as a diagnostic tool; if repeatable
1526 BIOS-originated corruption always affects the same memory,
1527 you can use memmap= to prevent the kernel from using that
1528 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001529
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001530config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001531 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001532 depends on X86_CHECK_BIOS_CORRUPTION
1533 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001534 ---help---
1535 Set whether the default state of memory_corruption_check is
1536 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001537
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001538config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001539 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1540 default 64
1541 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001542 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001543 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001544
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001545 The first page contains BIOS data structures that the kernel
1546 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001547
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001548 By default we reserve the first 64K of physical RAM, as a
1549 number of BIOSes are known to corrupt that memory range
1550 during events such as suspend/resume or monitor cable
1551 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001552
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001553 You can set this to 4 if you are absolutely sure that you
1554 trust the BIOS to get all its memory reservations and usages
1555 right. If you know your BIOS have problems beyond the
1556 default 64K area, you can set this to 640 to avoid using the
1557 entire low memory range.
1558
1559 If you have doubts about the BIOS (e.g. suspend/resume does
1560 not work or there's kernel crashes after certain hardware
1561 hotplug events) then you might want to enable
1562 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1563 typical corruption patterns.
1564
1565 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001566
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001567config MATH_EMULATION
1568 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001569 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001570 prompt "Math emulation" if X86_32
1571 ---help---
1572 Linux can emulate a math coprocessor (used for floating point
1573 operations) if you don't have one. 486DX and Pentium processors have
1574 a math coprocessor built in, 486SX and 386 do not, unless you added
1575 a 487DX or 387, respectively. (The messages during boot time can
1576 give you some hints here ["man dmesg"].) Everyone needs either a
1577 coprocessor or this emulation.
1578
1579 If you don't have a math coprocessor, you need to say Y here; if you
1580 say Y here even though you have a coprocessor, the coprocessor will
1581 be used nevertheless. (This behavior can be changed with the kernel
1582 command line option "no387", which comes handy if your coprocessor
1583 is broken. Try "man bootparam" or see the documentation of your boot
1584 loader (lilo or loadlin) about how to pass options to the kernel at
1585 boot time.) This means that it is a good idea to say Y here if you
1586 intend to use this kernel on different machines.
1587
1588 More information about the internals of the Linux math coprocessor
1589 emulation can be found in <file:arch/x86/math-emu/README>.
1590
1591 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1592 kernel, it won't hurt.
1593
1594config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001595 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001596 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001597 ---help---
1598 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1599 the Memory Type Range Registers (MTRRs) may be used to control
1600 processor access to memory ranges. This is most useful if you have
1601 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1602 allows bus write transfers to be combined into a larger transfer
1603 before bursting over the PCI/AGP bus. This can increase performance
1604 of image write operations 2.5 times or more. Saying Y here creates a
1605 /proc/mtrr file which may be used to manipulate your processor's
1606 MTRRs. Typically the X server should use this.
1607
1608 This code has a reasonably generic interface so that similar
1609 control registers on other processors can be easily supported
1610 as well:
1611
1612 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1613 Registers (ARRs) which provide a similar functionality to MTRRs. For
1614 these, the ARRs are used to emulate the MTRRs.
1615 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1616 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1617 write-combining. All of these processors are supported by this code
1618 and it makes sense to say Y here if you have one of them.
1619
1620 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1621 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1622 can lead to all sorts of problems, so it's good to say Y here.
1623
1624 You can safely say Y even if your machine doesn't have MTRRs, you'll
1625 just add about 9 KB to your kernel.
1626
Randy Dunlap7225e752008-07-26 17:54:22 -07001627 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001628
Yinghai Lu95ffa242008-04-29 03:52:33 -07001629config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001630 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001631 prompt "MTRR cleanup support"
1632 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001633 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001634 Convert MTRR layout from continuous to discrete, so X drivers can
1635 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001636
Thomas Gleixneraba37282008-07-15 14:48:48 +02001637 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001638 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001639 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001640
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001641 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001642
1643config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001644 int "MTRR cleanup enable value (0-1)"
1645 range 0 1
1646 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001647 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001648 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001649 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001650
Yinghai Lu12031a62008-05-02 02:40:22 -07001651config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1652 int "MTRR cleanup spare reg num (0-7)"
1653 range 0 7
1654 default "1"
1655 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001656 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001657 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001658 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001659
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001660config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001661 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001662 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001663 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001664 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001665 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001666
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001667 PATs are the modern equivalents of MTRRs and are much more
1668 flexible than MTRRs.
1669
1670 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001671 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001672
1673 If unsure, say Y.
1674
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001675config ARCH_USES_PG_UNCACHED
1676 def_bool y
1677 depends on X86_PAT
1678
H. Peter Anvin628c6242011-07-31 13:59:29 -07001679config ARCH_RANDOM
1680 def_bool y
1681 prompt "x86 architectural random number generator" if EXPERT
1682 ---help---
1683 Enable the x86 architectural RDRAND instruction
1684 (Intel Bull Mountain technology) to generate random numbers.
1685 If supported, this is a high bandwidth, cryptographically
1686 secure hardware random number generator.
1687
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001688config X86_SMAP
1689 def_bool y
1690 prompt "Supervisor Mode Access Prevention" if EXPERT
1691 ---help---
1692 Supervisor Mode Access Prevention (SMAP) is a security
1693 feature in newer Intel processors. There is a small
1694 performance cost if this enabled and turned on; there is
1695 also a small increase in the kernel size if this is enabled.
1696
1697 If unsure, say Y.
1698
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001699config X86_INTEL_MPX
1700 prompt "Intel MPX (Memory Protection Extensions)"
1701 def_bool n
1702 depends on CPU_SUP_INTEL
1703 ---help---
1704 MPX provides hardware features that can be used in
1705 conjunction with compiler-instrumented code to check
1706 memory references. It is designed to detect buffer
1707 overflow or underflow bugs.
1708
1709 This option enables running applications which are
1710 instrumented or otherwise use MPX. It does not use MPX
1711 itself inside the kernel or to protect the kernel
1712 against bad memory references.
1713
1714 Enabling this option will make the kernel larger:
1715 ~8k of kernel text and 36 bytes of data on a 64-bit
1716 defconfig. It adds a long to the 'mm_struct' which
1717 will increase the kernel memory overhead of each
1718 process and adds some branches to paths used during
1719 exec() and munmap().
1720
1721 For details, see Documentation/x86/intel_mpx.txt
1722
1723 If unsure, say N.
1724
Dave Hansen35e97792016-02-12 13:02:00 -08001725config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001726 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001727 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001728 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001729 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001730 ---help---
1731 Memory Protection Keys provides a mechanism for enforcing
1732 page-based protections, but without requiring modification of the
1733 page tables when an application changes protection domains.
1734
1735 For details, see Documentation/x86/protection-keys.txt
1736
1737 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001738
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001739config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001740 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001741 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001742 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001743 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001744 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001745 This enables the kernel to use EFI runtime services that are
1746 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001747
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001748 This option is only useful on systems that have EFI firmware.
1749 In addition, you should use the latest ELILO loader available
1750 at <http://elilo.sourceforge.net> in order to take advantage
1751 of EFI runtime services. However, even with this option, the
1752 resultant kernel should continue to boot on existing non-EFI
1753 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001754
Matt Fleming291f3632011-12-12 21:27:52 +00001755config EFI_STUB
1756 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001757 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001758 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001759 ---help---
1760 This kernel feature allows a bzImage to be loaded directly
1761 by EFI firmware without the use of a bootloader.
1762
Roy Franz4172fe22013-09-22 15:45:25 -07001763 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001764
Matt Fleming7d453ee2014-01-10 18:52:06 +00001765config EFI_MIXED
1766 bool "EFI mixed-mode support"
1767 depends on EFI_STUB && X86_64
1768 ---help---
1769 Enabling this feature allows a 64-bit kernel to be booted
1770 on a 32-bit firmware, provided that your CPU supports 64-bit
1771 mode.
1772
1773 Note that it is not possible to boot a mixed-mode enabled
1774 kernel via the EFI boot stub - a bootloader that supports
1775 the EFI handover protocol must be used.
1776
1777 If unsure, say N.
1778
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001779config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001780 def_bool y
1781 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001782 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001783 This kernel feature is useful for number crunching applications
1784 that may need to compute untrusted bytecode during their
1785 execution. By using pipes or other transports made available to
1786 the process as file descriptors supporting the read/write
1787 syscalls, it's possible to isolate those applications in
1788 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001789 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001790 and the task is only allowed to execute a few safe syscalls
1791 defined by each seccomp mode.
1792
1793 If unsure, say Y. Only embedded should say N here.
1794
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001795source kernel/Kconfig.hz
1796
1797config KEXEC
1798 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001799 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001800 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001801 kexec is a system call that implements the ability to shutdown your
1802 current kernel, and to start another kernel. It is like a reboot
1803 but it is independent of the system firmware. And like a reboot
1804 you can start any kernel with it, not just Linux.
1805
1806 The name comes from the similarity to the exec system call.
1807
1808 It is an ongoing process to be certain the hardware in a machine
1809 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001810 initially work for you. As of this writing the exact hardware
1811 interface is strongly in flux, so no good recommendation can be
1812 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001813
Vivek Goyal74ca3172014-08-29 15:18:46 -07001814config KEXEC_FILE
1815 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001816 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001817 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001818 depends on X86_64
1819 depends on CRYPTO=y
1820 depends on CRYPTO_SHA256=y
1821 ---help---
1822 This is new version of kexec system call. This system call is
1823 file based and takes file descriptors as system call argument
1824 for kernel and initramfs as opposed to list of segments as
1825 accepted by previous system call.
1826
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001827config KEXEC_VERIFY_SIG
1828 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001829 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001830 ---help---
1831 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001832 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001833
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001834 In addition to that option, you need to enable signature
1835 verification for the corresponding kernel image type being
1836 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001837
1838config KEXEC_BZIMAGE_VERIFY_SIG
1839 bool "Enable bzImage signature verification support"
1840 depends on KEXEC_VERIFY_SIG
1841 depends on SIGNED_PE_FILE_VERIFICATION
1842 select SYSTEM_TRUSTED_KEYRING
1843 ---help---
1844 Enable bzImage signature verification support.
1845
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001846config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001847 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001848 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001849 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001850 Generate crash dump after being started by kexec.
1851 This should be normally only set in special crash dump kernels
1852 which are loaded in the main kernel with kexec-tools into
1853 a specially reserved region and then later executed after
1854 a crash by kdump/kexec. The crash dump kernel must be compiled
1855 to a memory address not used by the main kernel or BIOS using
1856 PHYSICAL_START, or it must be built as a relocatable image
1857 (CONFIG_RELOCATABLE=y).
1858 For more details see Documentation/kdump/kdump.txt
1859
Huang Ying3ab83522008-07-25 19:45:07 -07001860config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001861 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001862 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001863 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001864 Jump between original kernel and kexeced kernel and invoke
1865 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001866
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001867config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001868 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001869 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001870 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001871 This gives the physical address where the kernel is loaded.
1872
1873 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1874 bzImage will decompress itself to above physical address and
1875 run from there. Otherwise, bzImage will run from the address where
1876 it has been loaded by the boot loader and will ignore above physical
1877 address.
1878
1879 In normal kdump cases one does not have to set/change this option
1880 as now bzImage can be compiled as a completely relocatable image
1881 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1882 address. This option is mainly useful for the folks who don't want
1883 to use a bzImage for capturing the crash dump and want to use a
1884 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1885 to be specifically compiled to run from a specific memory area
1886 (normally a reserved region) and this option comes handy.
1887
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001888 So if you are using bzImage for capturing the crash dump,
1889 leave the value here unchanged to 0x1000000 and set
1890 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1891 for capturing the crash dump change this value to start of
1892 the reserved region. In other words, it can be set based on
1893 the "X" value as specified in the "crashkernel=YM@XM"
1894 command line boot parameter passed to the panic-ed
1895 kernel. Please take a look at Documentation/kdump/kdump.txt
1896 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001897
1898 Usage of bzImage for capturing the crash dump is recommended as
1899 one does not have to build two kernels. Same kernel can be used
1900 as production kernel and capture kernel. Above option should have
1901 gone away after relocatable bzImage support is introduced. But it
1902 is present because there are users out there who continue to use
1903 vmlinux for dump capture. This option should go away down the
1904 line.
1905
1906 Don't change this unless you know what you are doing.
1907
1908config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001909 bool "Build a relocatable kernel"
1910 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001911 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001912 This builds a kernel image that retains relocation information
1913 so it can be loaded someplace besides the default 1MB.
1914 The relocations tend to make the kernel binary about 10% larger,
1915 but are discarded at runtime.
1916
1917 One use is for the kexec on panic case where the recovery kernel
1918 must live at a different physical address than the primary
1919 kernel.
1920
1921 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1922 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001923 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001924
Kees Cook8ab38202013-10-10 17:18:14 -07001925config RANDOMIZE_BASE
1926 bool "Randomize the address of the kernel image"
1927 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001928 default n
1929 ---help---
1930 Randomizes the physical and virtual address at which the
1931 kernel image is decompressed, as a security feature that
1932 deters exploit attempts relying on knowledge of the location
1933 of kernel internals.
1934
Kees Cooka653f352013-11-11 14:28:39 -08001935 Entropy is generated using the RDRAND instruction if it is
1936 supported. If RDTSC is supported, it is used as well. If
1937 neither RDRAND nor RDTSC are supported, then randomness is
1938 read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001939
1940 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
Kees Cooka653f352013-11-11 14:28:39 -08001941 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1942 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1943 minimum of 2MiB, only 10 bits of entropy is theoretically
1944 possible. At best, due to page table layouts, 64-bit can use
1945 9 bits of entropy and 32-bit uses 8 bits.
Kees Cook8ab38202013-10-10 17:18:14 -07001946
Kees Cookda2b6fb2013-12-10 12:27:45 -08001947 If unsure, say N.
1948
Kees Cook8ab38202013-10-10 17:18:14 -07001949config RANDOMIZE_BASE_MAX_OFFSET
Kees Cookda2b6fb2013-12-10 12:27:45 -08001950 hex "Maximum kASLR offset allowed" if EXPERT
Kees Cook8ab38202013-10-10 17:18:14 -07001951 depends on RANDOMIZE_BASE
Kees Cook6145cfe2013-10-10 17:18:18 -07001952 range 0x0 0x20000000 if X86_32
1953 default "0x20000000" if X86_32
1954 range 0x0 0x40000000 if X86_64
1955 default "0x40000000" if X86_64
Kees Cook8ab38202013-10-10 17:18:14 -07001956 ---help---
Kees Cookda2b6fb2013-12-10 12:27:45 -08001957 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1958 memory is used to determine the maximal offset in bytes that will
1959 be applied to the kernel when kernel Address Space Layout
1960 Randomization (kASLR) is active. This must be a multiple of
1961 PHYSICAL_ALIGN.
Kees Cook6145cfe2013-10-10 17:18:18 -07001962
Kees Cookda2b6fb2013-12-10 12:27:45 -08001963 On 32-bit this is limited to 512MiB by page table layouts. The
1964 default is 512MiB.
Kees Cook6145cfe2013-10-10 17:18:18 -07001965
Kees Cookda2b6fb2013-12-10 12:27:45 -08001966 On 64-bit this is limited by how the kernel fixmap page table is
1967 positioned, so this cannot be larger than 1GiB currently. Without
1968 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1969 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1970 modules area will shrink to compensate, up to the current maximum
1971 1GiB to 1GiB split. The default is 1GiB.
1972
1973 If unsure, leave at the default value.
Kees Cook8ab38202013-10-10 17:18:14 -07001974
1975# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001976config X86_NEED_RELOCS
1977 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001978 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001979
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001980config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001981 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001982 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001983 range 0x2000 0x1000000 if X86_32
1984 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001985 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001986 This value puts the alignment restrictions on physical address
1987 where kernel is loaded and run from. Kernel is compiled for an
1988 address which meets above alignment restriction.
1989
1990 If bootloader loads the kernel at a non-aligned address and
1991 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1992 address aligned to above value and run from there.
1993
1994 If bootloader loads the kernel at a non-aligned address and
1995 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1996 load address and decompress itself to the address it has been
1997 compiled for and run from there. The address for which kernel is
1998 compiled already meets above alignment restrictions. Hence the
1999 end result is that kernel runs from a physical address meeting
2000 above alignment restrictions.
2001
Kees Cooka0215062013-07-08 09:15:17 -07002002 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2003 this value must be a multiple of 0x200000.
2004
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002005 Don't change this unless you know what you are doing.
2006
2007config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05002008 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10002009 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002010 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05002011 Say Y here to allow turning CPUs off and on. CPUs can be
2012 controlled through /sys/devices/system/cpu.
2013 ( Note: power management support will enable this option
2014 automatically on SMP systems. )
2015 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002016
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002017config BOOTPARAM_HOTPLUG_CPU0
2018 bool "Set default setting of cpu0_hotpluggable"
2019 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002020 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002021 ---help---
2022 Set whether default state of cpu0_hotpluggable is on or off.
2023
2024 Say Y here to enable CPU0 hotplug by default. If this switch
2025 is turned on, there is no need to give cpu0_hotplug kernel
2026 parameter and the CPU0 hotplug feature is enabled by default.
2027
2028 Please note: there are two known CPU0 dependencies if you want
2029 to enable the CPU0 hotplug feature either by this switch or by
2030 cpu0_hotplug kernel parameter.
2031
2032 First, resume from hibernate or suspend always starts from CPU0.
2033 So hibernate and suspend are prevented if CPU0 is offline.
2034
2035 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2036 offline if any interrupt can not migrate out of CPU0. There may
2037 be other CPU0 dependencies.
2038
2039 Please make sure the dependencies are under your control before
2040 you enable this feature.
2041
2042 Say N if you don't want to enable CPU0 hotplug feature by default.
2043 You still can enable the CPU0 hotplug feature at boot by kernel
2044 parameter cpu0_hotplug.
2045
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002046config DEBUG_HOTPLUG_CPU0
2047 def_bool n
2048 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002049 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002050 ---help---
2051 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2052 soon as possible and boots up userspace with CPU0 offlined. User
2053 can online CPU0 back after boot time.
2054
2055 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2056 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2057 compilation or giving cpu0_hotplug kernel parameter at boot.
2058
2059 If unsure, say N.
2060
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002061config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002062 def_bool n
2063 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002064 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002065 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002066 Certain buggy versions of glibc will crash if they are
2067 presented with a 32-bit vDSO that is not mapped at the address
2068 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002069
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002070 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2071 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2072 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2073 the only released version with the bug, but OpenSUSE 9
2074 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002075
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002076 The symptom of the bug is that everything crashes on startup, saying:
2077 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2078
2079 Saying Y here changes the default value of the vdso32 boot
2080 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2081 This works around the glibc bug but hurts performance.
2082
2083 If unsure, say N: if you are compiling your own kernel, you
2084 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002085
Kees Cook3dc33bd2015-08-12 17:55:19 -07002086choice
2087 prompt "vsyscall table for legacy applications"
2088 depends on X86_64
2089 default LEGACY_VSYSCALL_EMULATE
2090 help
2091 Legacy user code that does not know how to find the vDSO expects
2092 to be able to issue three syscalls by calling fixed addresses in
2093 kernel space. Since this location is not randomized with ASLR,
2094 it can be used to assist security vulnerability exploitation.
2095
2096 This setting can be changed at boot time via the kernel command
2097 line parameter vsyscall=[native|emulate|none].
2098
2099 On a system with recent enough glibc (2.14 or newer) and no
2100 static binaries, you can say None without a performance penalty
2101 to improve security.
2102
2103 If unsure, select "Emulate".
2104
2105 config LEGACY_VSYSCALL_NATIVE
2106 bool "Native"
2107 help
2108 Actual executable code is located in the fixed vsyscall
2109 address mapping, implementing time() efficiently. Since
2110 this makes the mapping executable, it can be used during
2111 security vulnerability exploitation (traditionally as
2112 ROP gadgets). This configuration is not recommended.
2113
2114 config LEGACY_VSYSCALL_EMULATE
2115 bool "Emulate"
2116 help
2117 The kernel traps and emulates calls into the fixed
2118 vsyscall address mapping. This makes the mapping
2119 non-executable, but it still contains known contents,
2120 which could be used in certain rare security vulnerability
2121 exploits. This configuration is recommended when userspace
2122 still uses the vsyscall area.
2123
2124 config LEGACY_VSYSCALL_NONE
2125 bool "None"
2126 help
2127 There will be no vsyscall mapping at all. This will
2128 eliminate any risk of ASLR bypass due to the vsyscall
2129 fixed address mapping. Attempts to use the vsyscalls
2130 will be reported to dmesg, so that either old or
2131 malicious userspace programs can be identified.
2132
2133endchoice
2134
Tim Bird516cbf32008-08-12 12:52:36 -07002135config CMDLINE_BOOL
2136 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002137 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002138 Allow for specifying boot arguments to the kernel at
2139 build time. On some systems (e.g. embedded ones), it is
2140 necessary or convenient to provide some or all of the
2141 kernel boot arguments with the kernel itself (that is,
2142 to not rely on the boot loader to provide them.)
2143
2144 To compile command line arguments into the kernel,
2145 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002146 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002147
2148 Systems with fully functional boot loaders (i.e. non-embedded)
2149 should leave this option set to 'N'.
2150
2151config CMDLINE
2152 string "Built-in kernel command string"
2153 depends on CMDLINE_BOOL
2154 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002155 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002156 Enter arguments here that should be compiled into the kernel
2157 image and used at boot time. If the boot loader provides a
2158 command line at boot time, it is appended to this string to
2159 form the full kernel command line, when the system boots.
2160
2161 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2162 change this behavior.
2163
2164 In most cases, the command line (whether built-in or provided
2165 by the boot loader) should specify the device for the root
2166 file system.
2167
2168config CMDLINE_OVERRIDE
2169 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002170 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002171 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002172 Set this option to 'Y' to have the kernel ignore the boot loader
2173 command line, and use ONLY the built-in command line.
2174
2175 This is used to work around broken boot loaders. This should
2176 be set to 'N' under normal conditions.
2177
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002178config MODIFY_LDT_SYSCALL
2179 bool "Enable the LDT (local descriptor table)" if EXPERT
2180 default y
2181 ---help---
2182 Linux can allow user programs to install a per-process x86
2183 Local Descriptor Table (LDT) using the modify_ldt(2) system
2184 call. This is required to run 16-bit or segmented code such as
2185 DOSEMU or some Wine programs. It is also used by some very old
2186 threading libraries.
2187
2188 Enabling this feature adds a small amount of overhead to
2189 context switches and increases the low-level kernel attack
2190 surface. Disabling it removes the modify_ldt(2) system call.
2191
2192 Saying 'N' here may make sense for embedded or server kernels.
2193
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002194source "kernel/livepatch/Kconfig"
2195
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002196endmenu
2197
2198config ARCH_ENABLE_MEMORY_HOTPLUG
2199 def_bool y
2200 depends on X86_64 || (X86_32 && HIGHMEM)
2201
Gary Hade35551052008-10-31 10:52:03 -07002202config ARCH_ENABLE_MEMORY_HOTREMOVE
2203 def_bool y
2204 depends on MEMORY_HOTPLUG
2205
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002206config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002207 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002208 depends on NUMA
2209
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002210config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2211 def_bool y
2212 depends on X86_64 || X86_PAE
2213
Naoya Horiguchic177c812014-06-04 16:05:35 -07002214config ARCH_ENABLE_HUGEPAGE_MIGRATION
2215 def_bool y
2216 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2217
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002218menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002219
2220config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002221 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002222 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002223
2224source "kernel/power/Kconfig"
2225
2226source "drivers/acpi/Kconfig"
2227
Feng Tangefafc8b2009-08-14 15:23:29 -04002228source "drivers/sfi/Kconfig"
2229
Andi Kleena6b68072008-01-30 13:32:49 +01002230config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002231 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002232 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002233
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002234menuconfig APM
2235 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002236 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002237 ---help---
2238 APM is a BIOS specification for saving power using several different
2239 techniques. This is mostly useful for battery powered laptops with
2240 APM compliant BIOSes. If you say Y here, the system time will be
2241 reset after a RESUME operation, the /proc/apm device will provide
2242 battery status information, and user-space programs will receive
2243 notification of APM "events" (e.g. battery status change).
2244
2245 If you select "Y" here, you can disable actual use of the APM
2246 BIOS by passing the "apm=off" option to the kernel at boot time.
2247
2248 Note that the APM support is almost completely disabled for
2249 machines with more than one CPU.
2250
2251 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002252 and more information, read <file:Documentation/power/apm-acpi.txt>
2253 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002254 <http://www.tldp.org/docs.html#howto>.
2255
2256 This driver does not spin down disk drives (see the hdparm(8)
2257 manpage ("man 8 hdparm") for that), and it doesn't turn off
2258 VESA-compliant "green" monitors.
2259
2260 This driver does not support the TI 4000M TravelMate and the ACER
2261 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2262 desktop machines also don't have compliant BIOSes, and this driver
2263 may cause those machines to panic during the boot phase.
2264
2265 Generally, if you don't have a battery in your machine, there isn't
2266 much point in using this driver and you should say N. If you get
2267 random kernel OOPSes or reboots that don't seem to be related to
2268 anything, try disabling/enabling this option (or disabling/enabling
2269 APM in your BIOS).
2270
2271 Some other things you should try when experiencing seemingly random,
2272 "weird" problems:
2273
2274 1) make sure that you have enough swap space and that it is
2275 enabled.
2276 2) pass the "no-hlt" option to the kernel
2277 3) switch on floating point emulation in the kernel and pass
2278 the "no387" option to the kernel
2279 4) pass the "floppy=nodma" option to the kernel
2280 5) pass the "mem=4M" option to the kernel (thereby disabling
2281 all but the first 4 MB of RAM)
2282 6) make sure that the CPU is not over clocked.
2283 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2284 8) disable the cache from your BIOS settings
2285 9) install a fan for the video card or exchange video RAM
2286 10) install a better fan for the CPU
2287 11) exchange RAM chips
2288 12) exchange the motherboard.
2289
2290 To compile this driver as a module, choose M here: the
2291 module will be called apm.
2292
2293if APM
2294
2295config APM_IGNORE_USER_SUSPEND
2296 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002297 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002298 This option will ignore USER SUSPEND requests. On machines with a
2299 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2300 series notebooks, it is necessary to say Y because of a BIOS bug.
2301
2302config APM_DO_ENABLE
2303 bool "Enable PM at boot time"
2304 ---help---
2305 Enable APM features at boot time. From page 36 of the APM BIOS
2306 specification: "When disabled, the APM BIOS does not automatically
2307 power manage devices, enter the Standby State, enter the Suspend
2308 State, or take power saving steps in response to CPU Idle calls."
2309 This driver will make CPU Idle calls when Linux is idle (unless this
2310 feature is turned off -- see "Do CPU IDLE calls", below). This
2311 should always save battery power, but more complicated APM features
2312 will be dependent on your BIOS implementation. You may need to turn
2313 this option off if your computer hangs at boot time when using APM
2314 support, or if it beeps continuously instead of suspending. Turn
2315 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2316 T400CDT. This is off by default since most machines do fine without
2317 this feature.
2318
2319config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002320 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002321 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002322 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002323 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2324 On some machines, this can activate improved power savings, such as
2325 a slowed CPU clock rate, when the machine is idle. These idle calls
2326 are made after the idle loop has run for some length of time (e.g.,
2327 333 mS). On some machines, this will cause a hang at boot time or
2328 whenever the CPU becomes idle. (On machines with more than one CPU,
2329 this option does nothing.)
2330
2331config APM_DISPLAY_BLANK
2332 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002333 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002334 Enable console blanking using the APM. Some laptops can use this to
2335 turn off the LCD backlight when the screen blanker of the Linux
2336 virtual console blanks the screen. Note that this is only used by
2337 the virtual console screen blanker, and won't turn off the backlight
2338 when using the X Window system. This also doesn't have anything to
2339 do with your VESA-compliant power-saving monitor. Further, this
2340 option doesn't work for all laptops -- it might not turn off your
2341 backlight at all, or it might print a lot of errors to the console,
2342 especially if you are using gpm.
2343
2344config APM_ALLOW_INTS
2345 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002346 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002347 Normally we disable external interrupts while we are making calls to
2348 the APM BIOS as a measure to lessen the effects of a badly behaving
2349 BIOS implementation. The BIOS should reenable interrupts if it
2350 needs to. Unfortunately, some BIOSes do not -- especially those in
2351 many of the newer IBM Thinkpads. If you experience hangs when you
2352 suspend, try setting this to Y. Otherwise, say N.
2353
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002354endif # APM
2355
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002356source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002357
2358source "drivers/cpuidle/Kconfig"
2359
Andy Henroid27471fd2008-10-09 11:45:22 -07002360source "drivers/idle/Kconfig"
2361
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002362endmenu
2363
2364
2365menu "Bus options (PCI etc.)"
2366
2367config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002368 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002369 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002370 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002371 Find out whether you have a PCI motherboard. PCI is the name of a
2372 bus system, i.e. the way the CPU talks to the other stuff inside
2373 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2374 VESA. If you have PCI, say Y, otherwise N.
2375
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002376choice
2377 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002378 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002379 default PCI_GOANY
2380 ---help---
2381 On PCI systems, the BIOS can be used to detect the PCI devices and
2382 determine their configuration. However, some old PCI motherboards
2383 have BIOS bugs and may crash if this is done. Also, some embedded
2384 PCI-based systems don't have any BIOS at all. Linux can also try to
2385 detect the PCI hardware directly without using the BIOS.
2386
2387 With this option, you can specify how Linux should detect the
2388 PCI devices. If you choose "BIOS", the BIOS will be used,
2389 if you choose "Direct", the BIOS won't be used, and if you
2390 choose "MMConfig", then PCI Express MMCONFIG will be used.
2391 If you choose "Any", the kernel will try MMCONFIG, then the
2392 direct access method and falls back to the BIOS if that doesn't
2393 work. If unsure, go with the default, which is "Any".
2394
2395config PCI_GOBIOS
2396 bool "BIOS"
2397
2398config PCI_GOMMCONFIG
2399 bool "MMConfig"
2400
2401config PCI_GODIRECT
2402 bool "Direct"
2403
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002404config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002405 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002406 depends on OLPC
2407
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002408config PCI_GOANY
2409 bool "Any"
2410
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002411endchoice
2412
2413config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002414 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002415 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002416
2417# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2418config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002419 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002420 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002421
2422config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002423 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002424 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002425
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002426config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002427 def_bool y
2428 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002429
Alex Nixonb5401a92010-03-18 16:31:34 -04002430config PCI_XEN
2431 def_bool y
2432 depends on PCI && XEN
2433 select SWIOTLB_XEN
2434
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002435config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002436 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002437 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002438
2439config PCI_MMCONFIG
2440 bool "Support mmconfig PCI config space access"
2441 depends on X86_64 && PCI && ACPI
2442
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002443config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002444 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002445 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002446 help
2447 Read the PCI windows out of the CNB20LE host bridge. This allows
2448 PCI hotplug to work on systems with the CNB20LE chipset which do
2449 not have ACPI.
2450
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002451 There's no public spec for this chipset, and this functionality
2452 is known to be incomplete.
2453
2454 You should say N unless you know you need this.
2455
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002456source "drivers/pci/Kconfig"
2457
David Rientjes1c00f012011-03-22 16:34:59 -07002458# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002459config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002460 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2461 default y
2462 help
2463 Enables ISA-style DMA support for devices requiring such controllers.
2464 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002465
2466if X86_32
2467
2468config ISA
2469 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002470 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002471 Find out whether you have ISA slots on your motherboard. ISA is the
2472 name of a bus system, i.e. the way the CPU talks to the other stuff
2473 inside your box. Other bus systems are PCI, EISA, MicroChannel
2474 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2475 newer boards don't support it. If you have ISA, say Y, otherwise N.
2476
2477config EISA
2478 bool "EISA support"
2479 depends on ISA
2480 ---help---
2481 The Extended Industry Standard Architecture (EISA) bus was
2482 developed as an open alternative to the IBM MicroChannel bus.
2483
2484 The EISA bus provided some of the features of the IBM MicroChannel
2485 bus while maintaining backward compatibility with cards made for
2486 the older ISA bus. The EISA bus saw limited use between 1988 and
2487 1995 when it was made obsolete by the PCI bus.
2488
2489 Say Y here if you are building a kernel for an EISA-based machine.
2490
2491 Otherwise, say N.
2492
2493source "drivers/eisa/Kconfig"
2494
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002495config SCx200
2496 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002497 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002498 This provides basic support for National Semiconductor's
2499 (now AMD's) Geode processors. The driver probes for the
2500 PCI-IDs of several on-chip devices, so its a good dependency
2501 for other scx200_* drivers.
2502
2503 If compiled as a module, the driver is named scx200.
2504
2505config SCx200HR_TIMER
2506 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002507 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002508 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002509 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002510 This driver provides a clocksource built upon the on-chip
2511 27MHz high-resolution timer. Its also a workaround for
2512 NSC Geode SC-1100's buggy TSC, which loses time when the
2513 processor goes idle (as is done by the scheduler). The
2514 other workaround is idle=poll boot option.
2515
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002516config OLPC
2517 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002518 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002519 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002520 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002521 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002522 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002523 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002524 Add support for detecting the unique features of the OLPC
2525 XO hardware.
2526
Daniel Drakea3128582011-06-25 17:34:10 +01002527config OLPC_XO1_PM
2528 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002529 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002530 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002531 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002532 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002533
Daniel Drakecfee9592011-06-25 17:34:17 +01002534config OLPC_XO1_RTC
2535 bool "OLPC XO-1 Real Time Clock"
2536 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2537 ---help---
2538 Add support for the XO-1 real time clock, which can be used as a
2539 programmable wakeup source.
2540
Daniel Drake7feda8e2011-06-25 17:34:12 +01002541config OLPC_XO1_SCI
2542 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002543 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002544 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002545 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002546 select GPIO_CS5535
2547 select MFD_CORE
2548 ---help---
2549 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002550 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002551 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002552 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002553 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002554 - AC adapter status updates
2555 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002556
Daniel Drakea0f30f52011-06-25 17:34:18 +01002557config OLPC_XO15_SCI
2558 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002559 depends on OLPC && ACPI
2560 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002561 ---help---
2562 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2563 - EC-driven system wakeups
2564 - AC adapter status updates
2565 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002566
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002567config ALIX
2568 bool "PCEngines ALIX System Support (LED setup)"
2569 select GPIOLIB
2570 ---help---
2571 This option enables system support for the PCEngines ALIX.
2572 At present this just sets up LEDs for GPIO control on
2573 ALIX2/3/6 boards. However, other system specific setup should
2574 get added here.
2575
2576 Note: You must still enable the drivers for GPIO and LED support
2577 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2578
2579 Note: You have to set alix.force=1 for boards with Award BIOS.
2580
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002581config NET5501
2582 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2583 select GPIOLIB
2584 ---help---
2585 This option enables system support for the Soekris Engineering net5501.
2586
Philip A. Prindeville31970592012-01-14 01:45:39 -07002587config GEOS
2588 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2589 select GPIOLIB
2590 depends on DMI
2591 ---help---
2592 This option enables system support for the Traverse Technologies GEOS.
2593
Vivien Didelot7d029122013-01-04 16:18:14 -05002594config TS5500
2595 bool "Technologic Systems TS-5500 platform support"
2596 depends on MELAN
2597 select CHECK_SIGNATURE
2598 select NEW_LEDS
2599 select LEDS_CLASS
2600 ---help---
2601 This option enables system support for the Technologic Systems TS-5500.
2602
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002603endif # X86_32
2604
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002605config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002606 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002607 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002608
2609source "drivers/pcmcia/Kconfig"
2610
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002611config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002612 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002613 depends on PCI
2614 default n
2615 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002616 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002617 infrastructure code to support RapidIO interconnect devices.
2618
2619source "drivers/rapidio/Kconfig"
2620
David Herrmanne3263ab2013-08-02 14:05:22 +02002621config X86_SYSFB
2622 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2623 help
2624 Firmwares often provide initial graphics framebuffers so the BIOS,
2625 bootloader or kernel can show basic video-output during boot for
2626 user-guidance and debugging. Historically, x86 used the VESA BIOS
2627 Extensions and EFI-framebuffers for this, which are mostly limited
2628 to x86.
2629 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2630 framebuffers so the new generic system-framebuffer drivers can be
2631 used on x86. If the framebuffer is not compatible with the generic
2632 modes, it is adverticed as fallback platform framebuffer so legacy
2633 drivers like efifb, vesafb and uvesafb can pick it up.
2634 If this option is not selected, all system framebuffers are always
2635 marked as fallback platform framebuffers as usual.
2636
2637 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2638 not be able to pick up generic system framebuffers if this option
2639 is selected. You are highly encouraged to enable simplefb as
2640 replacement if you select this option. simplefb can correctly deal
2641 with generic system framebuffers. But you should still keep vesafb
2642 and others enabled as fallback if a system framebuffer is
2643 incompatible with simplefb.
2644
2645 If unsure, say Y.
2646
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002647endmenu
2648
2649
2650menu "Executable file formats / Emulations"
2651
2652source "fs/Kconfig.binfmt"
2653
2654config IA32_EMULATION
2655 bool "IA32 Emulation"
2656 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002657 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002658 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002659 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002660 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002661 Include code to run legacy 32-bit programs under a
2662 64-bit kernel. You should likely turn this on, unless you're
2663 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002664
2665config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002666 tristate "IA32 a.out support"
2667 depends on IA32_EMULATION
2668 ---help---
2669 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002670
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002671config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002672 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002673 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002674 ---help---
2675 Include code to run binaries for the x32 native 32-bit ABI
2676 for 64-bit processors. An x32 process gets access to the
2677 full 64-bit register file and wide data path while leaving
2678 pointers at 32 bits for smaller memory footprint.
2679
2680 You will need a recent binutils (2.22 or later) with
2681 elf32_x86_64 support enabled to compile a kernel with this
2682 option set.
2683
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002684config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002685 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002686 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002687
Jan Beulich3120e252012-09-10 12:41:45 +01002688if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002689config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002690 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002691
2692config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002693 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002694 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002695
David Howellsee009e4a02011-03-07 15:06:20 +00002696config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002697 def_bool y
2698 depends on KEYS
2699endif
David Howellsee009e4a02011-03-07 15:06:20 +00002700
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002701endmenu
2702
2703
Keith Packarde5beae12008-11-03 18:21:45 +01002704config HAVE_ATOMIC_IOMAP
2705 def_bool y
2706 depends on X86_32
2707
Alessandro Rubini4692d772012-04-04 19:39:58 +02002708config X86_DEV_DMA_OPS
2709 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002710 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002711
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002712config X86_DMA_REMAP
2713 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002714 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002715
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002716config PMC_ATOM
2717 def_bool y
2718 depends on PCI
2719
Keith Busch185a3832016-01-12 13:18:10 -07002720config VMD
2721 depends on PCI_MSI
2722 tristate "Volume Management Device Driver"
2723 default N
2724 ---help---
2725 Adds support for the Intel Volume Management Device (VMD). VMD is a
2726 secondary PCI host bridge that allows PCI Express root ports,
2727 and devices attached to them, to be removed from the default
2728 PCI domain and placed within the VMD domain. This provides
2729 more bus resources than are otherwise possible with a
2730 single domain. If you know your system provides one of these and
2731 has devices attached to it, say Y; if you are not sure, say N.
2732
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002733source "net/Kconfig"
2734
2735source "drivers/Kconfig"
2736
2737source "drivers/firmware/Kconfig"
2738
2739source "fs/Kconfig"
2740
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002741source "arch/x86/Kconfig.debug"
2742
2743source "security/Kconfig"
2744
2745source "crypto/Kconfig"
2746
Avi Kivityedf88412007-12-16 11:02:48 +02002747source "arch/x86/kvm/Kconfig"
2748
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002749source "lib/Kconfig"