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Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01001# Select 32 or 64 bit
2config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01003 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00004 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01005 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01006 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010010 def_bool y
11 depends on !64BIT
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010012
13config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010014 def_bool y
15 depends on 64BIT
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010016
17### Arch settings
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010018config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010019 def_bool y
Ingo Molnar6471b822015-06-03 10:00:13 +020020 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Stephen Boyd446f24d2013-04-30 15:28:42 -070026 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Dan Williams21266be2015-11-19 18:19:29 -080027 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020028 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070029 select ARCH_HAS_FAST_MULTIPLIER
Riku Voipio957e3fa2014-12-12 16:57:44 -080030 select ARCH_HAS_GCOV_PROFILE_ALL
Dmitry Vyukov5c9a8752016-03-22 14:27:30 -070031 select ARCH_HAS_KCOV if X86_64
Dan Williams96601ad2015-08-24 18:29:38 -040032 select ARCH_HAS_PMEM_API if X86_64
Ross Zwisler67a3e8f2015-08-27 13:14:20 -060033 select ARCH_HAS_MMIO_FLUSH
Ingo Molnar6471b822015-06-03 10:00:13 +020034 select ARCH_HAS_SG_CHAIN
Andrey Ryabininc6d30852016-01-20 15:00:55 -080035 select ARCH_HAS_UBSAN_SANITIZE_ALL
Ingo Molnar6471b822015-06-03 10:00:13 +020036 select ARCH_HAVE_NMI_SAFE_CMPXCHG
37 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040038 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080039 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020040 select ARCH_SUPPORTS_ATOMIC_RMW
Mel Gorman3b242c62015-06-30 14:57:13 -070041 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
Ingo Molnar6471b822015-06-03 10:00:13 +020042 select ARCH_SUPPORTS_INT128 if X86_64
43 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
44 select ARCH_USE_BUILTIN_BSWAP
45 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
46 select ARCH_USE_QUEUED_RWLOCKS
47 select ARCH_USE_QUEUED_SPINLOCKS
Mel Gorman72b252a2015-09-04 15:47:32 -070048 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +020049 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Ingo Molnarda4276b2009-01-07 11:05:10 +010050 select ARCH_WANT_FRAME_POINTERS
Ingo Molnar6471b822015-06-03 10:00:13 +020051 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
52 select ARCH_WANT_OPTIONAL_GPIOLIB
53 select BUILDTIME_EXTABLE_SORT
54 select CLKEVT_I8253
55 select CLKSRC_I8253 if X86_32
56 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
57 select CLOCKSOURCE_WATCHDOG
58 select CLONE_BACKWARDS if X86_32
59 select COMPAT_OLD_SIGACTION if IA32_EMULATION
60 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070061 select EDAC_ATOMIC_SCRUB
62 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020063 select GENERIC_CLOCKEVENTS
64 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
65 select GENERIC_CLOCKEVENTS_MIN_ADJUST
66 select GENERIC_CMOS_UPDATE
67 select GENERIC_CPU_AUTOPROBE
68 select GENERIC_EARLY_IOREMAP
69 select GENERIC_FIND_FIRST_BIT
70 select GENERIC_IOMAP
71 select GENERIC_IRQ_PROBE
72 select GENERIC_IRQ_SHOW
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_SMP_IDLE_THREAD
75 select GENERIC_STRNCPY_FROM_USER
76 select GENERIC_STRNLEN_USER
77 select GENERIC_TIME_VSYSCALL
78 select HAVE_ACPI_APEI if ACPI
79 select HAVE_ACPI_APEI_NMI if ACPI
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_AOUT if X86_32
82 select HAVE_ARCH_AUDITSYSCALL
83 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
84 select HAVE_ARCH_JUMP_LABEL
85 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
86 select HAVE_ARCH_KGDB
87 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080088 select HAVE_ARCH_MMAP_RND_BITS if MMU
89 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020090 select HAVE_ARCH_SECCOMP_FILTER
91 select HAVE_ARCH_SOFT_DIRTY if X86_64
92 select HAVE_ARCH_TRACEHOOK
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Daniel Borkmann60777762016-05-13 19:08:28 +020094 select HAVE_EBPF_JIT if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020095 select HAVE_CC_STACKPROTECTOR
96 select HAVE_CMPXCHG_DOUBLE
97 select HAVE_CMPXCHG_LOCAL
98 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -070099 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200100 select HAVE_C_RECORDMCOUNT
101 select HAVE_DEBUG_KMEMLEAK
102 select HAVE_DEBUG_STACKOVERFLOW
103 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700104 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400105 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900106 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700107 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700108 select HAVE_EXIT_THREAD
Ingo Molnar6471b822015-06-03 10:00:13 +0200109 select HAVE_FENTRY if X86_64
110 select HAVE_FTRACE_MCOUNT_RECORD
111 select HAVE_FUNCTION_GRAPH_FP_TEST
112 select HAVE_FUNCTION_GRAPH_TRACER
113 select HAVE_FUNCTION_TRACER
114 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530115 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200116 select HAVE_IDE
117 select HAVE_IOREMAP_PROT
118 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
119 select HAVE_IRQ_TIME_ACCOUNTING
120 select HAVE_KERNEL_BZIP2
121 select HAVE_KERNEL_GZIP
122 select HAVE_KERNEL_LZ4
123 select HAVE_KERNEL_LZMA
124 select HAVE_KERNEL_LZO
125 select HAVE_KERNEL_XZ
126 select HAVE_KPROBES
127 select HAVE_KPROBES_ON_FTRACE
128 select HAVE_KRETPROBES
129 select HAVE_KVM
130 select HAVE_LIVEPATCH if X86_64
131 select HAVE_MEMBLOCK
132 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200133 select HAVE_MIXED_BREAKPOINTS_REGS
Ingo Molnar6471b822015-06-03 10:00:13 +0200134 select HAVE_OPROFILE
135 select HAVE_OPTPROBES
136 select HAVE_PCSPKR_PLATFORM
137 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200138 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200139 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200140 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200141 select HAVE_REGS_AND_STACK_ACCESS_API
142 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400143 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300145 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100146 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200147 select MODULES_USE_ELF_RELA if X86_64
148 select MODULES_USE_ELF_REL if X86_32
149 select OLD_SIGACTION if X86_32
150 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
151 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500152 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200153 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500154 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200155 select SYSCTL_EXCEPTION_TRACE
156 select USER_STACKTRACE_SUPPORT
157 select VIRT_TO_BUS
158 select X86_DEV_DMA_OPS if X86_64
159 select X86_FEATURE_NAMES if PROC_FS
Josh Poimboeufd4883d52016-02-28 22:22:43 -0600160 select HAVE_STACK_VALIDATION if X86_64
Dave Hansen63c17fb2016-02-12 13:02:08 -0800161 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen66d37572016-02-12 13:02:32 -0800162 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530163
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200164config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100165 def_bool y
166 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200167
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700168config OUTPUT_FORMAT
169 string
170 default "elf32-i386" if X86_32
171 default "elf64-x86-64" if X86_64
172
Sam Ravnborg73531902008-05-25 23:03:18 +0200173config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200174 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200175 default "arch/x86/configs/i386_defconfig" if X86_32
176 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200177
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100178config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100179 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100180
181config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100182 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100183
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100184config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100185 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100186
Daniel Cashman9e08f572016-01-14 15:20:06 -0800187config ARCH_MMAP_RND_BITS_MIN
188 default 28 if 64BIT
189 default 8
190
191config ARCH_MMAP_RND_BITS_MAX
192 default 32 if 64BIT
193 default 16
194
195config ARCH_MMAP_RND_COMPAT_BITS_MIN
196 default 8
197
198config ARCH_MMAP_RND_COMPAT_BITS_MAX
199 default 16
200
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100201config SBUS
202 bool
203
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800204config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100205 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400206 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800207
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700208config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700209 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700210
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100211config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100212 def_bool y
213 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100214
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100215config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100216 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100217 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000218 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
219
220config GENERIC_BUG_RELATIVE_POINTERS
221 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100222
223config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100224 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100225
226config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100227 def_bool y
228 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100229
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100230config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100231 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100232
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100233config GENERIC_CALIBRATE_DELAY
234 def_bool y
235
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800236config ARCH_HAS_CPU_RELAX
237 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100238
Pekka Enberg1b27d052008-04-28 02:12:22 -0700239config ARCH_HAS_CACHE_LINE_SIZE
240 def_bool y
241
Mike Travisdd5af902008-01-30 13:33:32 +0100242config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900243 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100244
Tejun Heo08fc4582009-08-14 15:00:49 +0900245config NEED_PER_CPU_EMBED_FIRST_CHUNK
246 def_bool y
247
248config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900249 def_bool y
250
Johannes Berg801e4062007-12-08 02:12:39 +0100251config ARCH_HIBERNATION_POSSIBLE
252 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100253
Johannes Bergf4cb5702007-12-08 02:14:00 +0100254config ARCH_SUSPEND_POSSIBLE
255 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100256
Steve Cappercfe28c52013-04-29 14:29:48 +0100257config ARCH_WANT_HUGE_PMD_SHARE
258 def_bool y
259
Steve Capper53313b22013-04-30 08:03:42 +0100260config ARCH_WANT_GENERAL_HUGETLB
261 def_bool y
262
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100263config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000264 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100265
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100266config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000267 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100268
Ingo Molnar765c68b2008-04-09 11:03:37 +0200269config ARCH_SUPPORTS_OPTIMIZED_INLINING
270 def_bool y
271
Akinobu Mita6a11f752009-03-31 15:23:17 -0700272config ARCH_SUPPORTS_DEBUG_PAGEALLOC
273 def_bool y
274
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300275config KASAN_SHADOW_OFFSET
276 hex
277 depends on KASAN
278 default 0xdffffc0000000000
279
Shane Wang69575d32009-09-01 18:25:07 -0700280config HAVE_INTEL_TXT
281 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700282 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700283
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100284config X86_32_SMP
285 def_bool y
286 depends on X86_32 && SMP
287
288config X86_64_SMP
289 def_bool y
290 depends on X86_64 && SMP
291
Tejun Heoccbeed32009-02-09 22:17:40 +0900292config X86_32_LAZY_GS
293 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900294 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900295
Borislav Petkovd61931d2010-03-05 17:34:46 +0100296config ARCH_HWEIGHT_CFLAGS
297 string
298 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
299 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
300
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530301config ARCH_SUPPORTS_UPROBES
302 def_bool y
303
Rob Herringd20642f2014-04-18 17:19:54 -0500304config FIX_EARLYCON_MEM
305 def_bool y
306
Kees Cook9ccaf772016-02-17 14:41:14 -0800307config DEBUG_RODATA
308 def_bool y
309
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700310config PGTABLE_LEVELS
311 int
312 default 4 if X86_64
313 default 3 if X86_PAE
314 default 2
315
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100316source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700317source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100318
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100319menu "Processor type and features"
320
Randy Dunlap5ee71532012-01-16 11:57:18 -0800321config ZONE_DMA
322 bool "DMA memory allocation support" if EXPERT
323 default y
324 help
325 DMA memory allocation support allows devices with less than 32-bit
326 addressing to allocate within the first 16MB of address space.
327 Disable if no such devices will be used.
328
329 If unsure, say Y.
330
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100331config SMP
332 bool "Symmetric multi-processing support"
333 ---help---
334 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800335 a system with only one CPU, say N. If you have a system with more
336 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100337
Robert Graffham4a474152014-01-23 15:55:29 -0800338 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100339 machines, but will use only one CPU of a multiprocessor machine. If
340 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800341 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100342 will run faster if you say N here.
343
344 Note that if you say Y here and choose architecture "586" or
345 "Pentium" under "Processor family", the kernel will not work on 486
346 architectures. Similarly, multiprocessor kernels for the "PPro"
347 architecture may not work on all Pentium based boards.
348
349 People using multiprocessor machines who say Y here should also say
350 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
351 Management" code will be disabled if you say Y here.
352
Paul Bolle395cf962011-08-15 02:02:26 +0200353 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100354 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
355 <http://www.tldp.org/docs.html#howto>.
356
357 If you don't know what to do here, say N.
358
Josh Triplett9def39be2013-10-30 08:09:45 -0700359config X86_FEATURE_NAMES
360 bool "Processor feature human-readable names" if EMBEDDED
361 default y
362 ---help---
363 This option compiles in a table of x86 feature bits and corresponding
364 names. This is required to support /proc/cpuinfo and a few kernel
365 messages. You can disable this to save space, at the expense of
366 making those few kernel messages show numeric feature bits instead.
367
368 If in doubt, say Y.
369
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100370config X86_FAST_FEATURE_TESTS
371 bool "Fast CPU feature tests" if EMBEDDED
372 default y
373 ---help---
374 Some fast-paths in the kernel depend on the capabilities of the CPU.
375 Say Y here for the kernel to patch in the appropriate code at runtime
376 based on the capabilities of the CPU. The infrastructure for patching
377 code at runtime takes up some additional space; space-constrained
378 embedded systems may wish to say N here to produce smaller, slightly
379 slower code.
380
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800381config X86_X2APIC
382 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200383 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800384 ---help---
385 This enables x2apic support on CPUs that have this feature.
386
387 This allows 32-bit apic IDs (so it can support very large systems),
388 and accesses the local apic via MSRs not via mmio.
389
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800390 If you don't know what to do here, say N.
391
Yinghai Lu6695c852008-06-19 12:13:09 -0700392config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700393 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000394 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200395 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100396 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700397 For old smp systems that do not have proper acpi support. Newer systems
398 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700399
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800400config X86_BIGSMP
401 bool "Support for big SMP systems with more than 8 CPUs"
402 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100403 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800404 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100405
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000406config GOLDFISH
407 def_bool y
408 depends on X86_GOLDFISH
409
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800410if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800411config X86_EXTENDED_PLATFORM
412 bool "Support for extended (non-PC) x86 platforms"
413 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100414 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100415 If you disable this option then the kernel will only support
416 standard PC platforms. (which covers the vast majority of
417 systems out there.)
418
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800419 If you enable this option then you'll be able to select support
420 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100421 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800422 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800423 RDC R-321x SoC
424 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200425 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200426 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100427
428 If you have one of these systems, or if you want to build a
429 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800430endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100431
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800432if X86_64
433config X86_EXTENDED_PLATFORM
434 bool "Support for extended (non-PC) x86 platforms"
435 default y
436 ---help---
437 If you disable this option then the kernel will only support
438 standard PC platforms. (which covers the vast majority of
439 systems out there.)
440
441 If you enable this option then you'll be able to select support
442 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800443 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800444 ScaleMP vSMP
445 SGI Ultraviolet
446
447 If you have one of these systems, or if you want to build a
448 generic distribution kernel, say Y here - otherwise say N.
449endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800450# This is an alphabetically sorted list of 64 bit extended platforms
451# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800452config X86_NUMACHIP
453 bool "Numascale NumaChip"
454 depends on X86_64
455 depends on X86_EXTENDED_PLATFORM
456 depends on NUMA
457 depends on SMP
458 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700459 depends on PCI_MMCONFIG
Steffen Persvold44b111b52011-12-06 00:07:26 +0800460 ---help---
461 Adds support for Numascale NumaChip large-SMP systems. Needed to
462 enable more than ~168 cores.
463 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100464
Ingo Molnar6a485652009-01-27 18:29:13 +0100465config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800466 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100467 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100468 select PARAVIRT
469 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800470 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300471 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100472 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100473 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
474 supposed to run on these EM64T-based machines. Only choose this option
475 if you have one of these machines.
476
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800477config X86_UV
478 bool "SGI Ultraviolet"
479 depends on X86_64
480 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500481 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800482 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700483 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200484 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800485 ---help---
486 This option is needed in order to support SGI Ultraviolet systems.
487 If you don't have one of these, you should say N here.
488
489# Following is an alphabetically sorted list of 32 bit extended platforms
490# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100491
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000492config X86_GOLDFISH
493 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100494 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000495 ---help---
496 Enable support for the Goldfish virtual platform used primarily
497 for Android development. Unless you are building for the Android
498 Goldfish emulator say N here.
499
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800500config X86_INTEL_CE
501 bool "CE4100 TV platform"
502 depends on PCI
503 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800504 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800505 depends on X86_32
506 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800507 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100508 select OF
509 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800510 ---help---
511 Select for the Intel CE media processor (CE4100) SOC.
512 This option compiles in support for the CE4100 SOC for settop
513 boxes and media devices.
514
David Cohen4cb9b002013-12-16 17:37:26 -0800515config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100516 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100517 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800518 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000519 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200520 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000521 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000522 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800523 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000524 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000525 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000526 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000527 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000528 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800529 Select to build a kernel capable of supporting Intel MID (Mobile
530 Internet Device) platform systems which do not have the PCI legacy
531 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000532
David Cohen4cb9b002013-12-16 17:37:26 -0800533 Intel MID platforms are based on an Intel processor and chipset which
534 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100535
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000536config X86_INTEL_QUARK
537 bool "Intel Quark platform support"
538 depends on X86_32
539 depends on X86_EXTENDED_PLATFORM
540 depends on X86_PLATFORM_DEVICES
541 depends on X86_TSC
542 depends on PCI
543 depends on PCI_GOANY
544 depends on X86_IO_APIC
545 select IOSF_MBI
546 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200547 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000548 ---help---
549 Select to include support for Quark X1000 SoC.
550 Say Y here if you have a Quark based system such as the Arduino
551 compatible Intel Galileo.
552
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000553config X86_INTEL_LPSS
554 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100555 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000556 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300557 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100558 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000559 ---help---
560 Select to build support for Intel Low Power Subsystem such as
561 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300562 things like clock tree (common clock framework) and pincontrol
563 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000564
Ken Xue92082a82015-02-06 08:27:51 +0800565config X86_AMD_PLATFORM_DEVICE
566 bool "AMD ACPI2Platform devices support"
567 depends on ACPI
568 select COMMON_CLK
569 select PINCTRL
570 ---help---
571 Select to interpret AMD specific ACPI device to platform device
572 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
573 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
574 implemented under PINCTRL subsystem.
575
David E. Boxced3ce72014-09-17 22:13:50 -0700576config IOSF_MBI
577 tristate "Intel SoC IOSF Sideband support for SoC platforms"
578 depends on PCI
579 ---help---
580 This option enables sideband register access support for Intel SoC
581 platforms. On these platforms the IOSF sideband is used in lieu of
582 MSR's for some register accesses, mostly but not limited to thermal
583 and power. Drivers may query the availability of this device to
584 determine if they need the sideband in order to work on these
585 platforms. The sideband is available on the following SoC products.
586 This list is not meant to be exclusive.
587 - BayTrail
588 - Braswell
589 - Quark
590
591 You should say Y if you are running a kernel on one of these SoC's.
592
David E. Boxed2226b2014-09-17 22:13:51 -0700593config IOSF_MBI_DEBUG
594 bool "Enable IOSF sideband access through debugfs"
595 depends on IOSF_MBI && DEBUG_FS
596 ---help---
597 Select this option to expose the IOSF sideband access registers (MCR,
598 MDR, MCRX) through debugfs to write and read register information from
599 different units on the SoC. This is most useful for obtaining device
600 state information for debug and analysis. As this is a general access
601 mechanism, users of this option would have specific knowledge of the
602 device they want to access.
603
604 If you don't require the option or are in doubt, say N.
605
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800606config X86_RDC321X
607 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100608 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800609 depends on X86_EXTENDED_PLATFORM
610 select M486
611 select X86_REBOOTFIXUPS
612 ---help---
613 This option is needed for RDC R-321x system-on-chip, also known
614 as R-8610-(G).
615 If you don't have one of these chips, you should say N here.
616
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100617config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100618 bool "Support non-standard 32-bit SMP architectures"
619 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800620 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100621 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800622 This option compiles in the bigsmp and STA2X11 default
623 subarchitectures. It is intended for a generic binary
624 kernel. If you select them all, kernel will probe it one by
625 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700626
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800627# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700628
Linus Torvaldsd949f362009-09-26 09:35:07 -0700629config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100630 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700631 # MCE code calls memory_failure():
632 depends on X86_MCE
633 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700634 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
635 depends on X86_64 || !SPARSEMEM
636 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700637
Alessandro Rubini83125a32012-04-04 19:40:21 +0200638config STA2X11
639 bool "STA2X11 Companion Chip Support"
640 depends on X86_32_NON_STANDARD && PCI
641 select X86_DEV_DMA_OPS
642 select X86_DMA_REMAP
643 select SWIOTLB
644 select MFD_STA2X11
645 select ARCH_REQUIRE_GPIOLIB
646 default n
647 ---help---
648 This adds support for boards based on the STA2X11 IO-Hub,
649 a.k.a. "ConneXt". The chip is used in place of the standard
650 PC chipset, so all "standard" peripherals are missing. If this
651 option is selected the kernel will still be able to boot on
652 standard PC machines.
653
Shérab82148d12010-09-25 06:06:57 +0200654config X86_32_IRIS
655 tristate "Eurobraille/Iris poweroff module"
656 depends on X86_32
657 ---help---
658 The Iris machines from EuroBraille do not have APM or ACPI support
659 to shut themselves down properly. A special I/O sequence is
660 needed to do so, which is what this module does at
661 kernel shutdown.
662
663 This is only for Iris machines from EuroBraille.
664
665 If unused, say N.
666
Ingo Molnarae1e9132008-11-11 09:05:16 +0100667config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100668 def_bool y
669 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800670 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100671 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100672 Calculate simpler /proc/<PID>/wchan values. If this option
673 is disabled then wchan values will recurse back to the
674 caller function. This provides more accurate wchan values,
675 at the expense of slightly more scheduling overhead.
676
677 If in doubt, say "Y".
678
Borislav Petkov6276a072013-03-04 21:20:21 +0100679menuconfig HYPERVISOR_GUEST
680 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100681 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100682 Say Y here to enable options for running Linux under various hyper-
683 visors. This option enables basic hypervisor detection and platform
684 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100685
Borislav Petkov6276a072013-03-04 21:20:21 +0100686 If you say N, all options in this submenu will be skipped and
687 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100688
Borislav Petkov6276a072013-03-04 21:20:21 +0100689if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100690
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100691config PARAVIRT
692 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100693 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100694 This changes the kernel so it can modify itself when it is run
695 under a hypervisor, potentially improving performance significantly
696 over full virtualization. However, when run without a hypervisor
697 the kernel is theoretically slower and slightly larger.
698
Borislav Petkov6276a072013-03-04 21:20:21 +0100699config PARAVIRT_DEBUG
700 bool "paravirt-ops debugging"
701 depends on PARAVIRT && DEBUG_KERNEL
702 ---help---
703 Enable to debug paravirt_ops internals. Specifically, BUG if
704 a paravirt_op is missing when it is called.
705
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700706config PARAVIRT_SPINLOCKS
707 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700708 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200709 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700710 ---help---
711 Paravirtualized spinlocks allow a pvops backend to replace the
712 spinlock implementation with something virtualization-friendly
713 (for example, block the virtual CPU rather than spinning).
714
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530715 It has a minimal impact on native kernels and gives a nice performance
716 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700717
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530718 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700719
Waiman Long45e898b2015-11-09 19:09:25 -0500720config QUEUED_LOCK_STAT
721 bool "Paravirt queued spinlock statistics"
722 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
723 ---help---
724 Enable the collection of statistical data on the slowpath
725 behavior of paravirtualized queued spinlocks and report
726 them on debugfs.
727
Borislav Petkov6276a072013-03-04 21:20:21 +0100728source "arch/x86/xen/Kconfig"
729
730config KVM_GUEST
731 bool "KVM Guest support (including kvmclock)"
732 depends on PARAVIRT
733 select PARAVIRT_CLOCK
734 default y
735 ---help---
736 This option enables various optimizations for running under the KVM
737 hypervisor. It includes a paravirtualized clock, so that instead
738 of relying on a PIT (or probably other) emulation by the
739 underlying device model, the host provides the guest with
740 timing infrastructure such as time of day, and system time
741
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530742config KVM_DEBUG_FS
743 bool "Enable debug information for KVM Guests in debugfs"
744 depends on KVM_GUEST && DEBUG_FS
745 default n
746 ---help---
747 This option enables collection of various statistics for KVM guest.
748 Statistics are displayed in debugfs filesystem. Enabling this option
749 may incur significant overhead.
750
Borislav Petkov6276a072013-03-04 21:20:21 +0100751source "arch/x86/lguest/Kconfig"
752
753config PARAVIRT_TIME_ACCOUNTING
754 bool "Paravirtual steal time accounting"
755 depends on PARAVIRT
756 default n
757 ---help---
758 Select this option to enable fine granularity task steal time
759 accounting. Time spent executing other tasks in parallel with
760 the current vCPU is discounted from the vCPU power. To account for
761 that, there can be a small performance impact.
762
763 If in doubt, say N here.
764
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200765config PARAVIRT_CLOCK
766 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200767
Borislav Petkov6276a072013-03-04 21:20:21 +0100768endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400769
Yinghai Lu08677212010-02-10 01:20:20 -0800770config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700771 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800772
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100773source "arch/x86/Kconfig.cpu"
774
775config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100776 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100777 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100778 ---help---
779 Use the IA-PC HPET (High Precision Event Timer) to manage
780 time in preference to the PIT and RTC, if a HPET is
781 present.
782 HPET is the next generation timer replacing legacy 8254s.
783 The HPET provides a stable time base on SMP
784 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200785 as it is off-chip. The interface used is documented
786 in the HPET spec, revision 1.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100787
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100788 You can safely choose Y here. However, HPET will only be
789 activated if the platform and the BIOS support this feature.
790 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100791
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100792 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100793
794config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100795 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800796 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100797
Jacob Panbb24c472009-09-02 07:37:17 -0700798config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000799 def_bool y if X86_INTEL_MID
800 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100801 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000802 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700803 help
804 APB timer is the replacement for 8254, HPET on X86 MID platforms.
805 The APBT provides a stable time base on SMP
806 systems, unlike the TSC, but it is more expensive to access,
807 as it is off-chip. APB timers are always running regardless of CPU
808 C states, they are used as per CPU clockevent device when possible.
809
David Rientjes6a108a12011-01-20 14:44:16 -0800810# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100811# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700812config DMI
813 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800814 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800815 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100816 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700817 Enabled scanning of DMI to identify machine quirks. Say Y
818 here unless you have verified that your setup is not
819 affected by entries in the DMI blacklist. Required by PNP
820 BIOS code.
821
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100822config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700823 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100824 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200825 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100826 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200827 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
828 GART based hardware IOMMUs.
829
830 The GART supports full DMA access for devices with 32-bit access
831 limitations, on systems with more than 3 GB. This is usually needed
832 for USB, sound, many IDE/SATA chipsets and some other devices.
833
834 Newer systems typically have a modern AMD IOMMU, supported via
835 the CONFIG_AMD_IOMMU=y config option.
836
837 In normal configurations this driver is only active when needed:
838 there's more than 3 GB of memory and the system contains a
839 32-bit limited device.
840
841 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100842
843config CALGARY_IOMMU
844 bool "IBM Calgary IOMMU support"
845 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700846 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100847 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100848 Support for hardware IOMMUs in IBM's xSeries x366 and x460
849 systems. Needed to run systems with more than 3GB of memory
850 properly with 32-bit PCI devices that do not support DAC
851 (Double Address Cycle). Calgary also supports bus level
852 isolation, where all DMAs pass through the IOMMU. This
853 prevents them from going anywhere except their intended
854 destination. This catches hard-to-find kernel bugs and
855 mis-behaving drivers and devices that do not use the DMA-API
856 properly to set up their DMA buffers. The IOMMU can be
857 turned off at boot time with the iommu=off parameter.
858 Normally the kernel will make the right choice by itself.
859 If unsure, say Y.
860
861config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100862 def_bool y
863 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100864 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100865 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100866 Should Calgary be enabled by default? if you choose 'y', Calgary
867 will be used (if it exists). If you choose 'n', Calgary will not be
868 used even if it exists. If you choose 'n' and would like to use
869 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
870 If unsure, say Y.
871
872# need this always selected by IOMMU for the VIA workaround
873config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100874 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100875 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100876 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700877 which don't have a hardware IOMMU. Using this PCI devices
878 which can only access 32-bits of memory can be used on systems
879 with more than 3 GB of memory.
880 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100881
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700882config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100883 def_bool y
884 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700885
Mike Travis1184dc22008-05-12 21:21:12 +0200886config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200887 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700888 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800889 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100890 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200891 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200892 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100893
894config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800895 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400896 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500897 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500898 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800899 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500900 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800901 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300902 default "8" if SMP && X86_32
903 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100904 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100905 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500906 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300907 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100908 minimum value which makes sense is 2.
909
910 This is purely to save memory - each supported CPU adds
911 approximately eight kilobytes to the kernel image.
912
913config SCHED_SMT
914 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200915 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100916 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100917 SMT scheduler support improves the CPU scheduler's decision making
918 when dealing with Intel Pentium 4 chips with HyperThreading at a
919 cost of slightly increased overhead in some places. If unsure say
920 N here.
921
922config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100923 def_bool y
924 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200925 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100926 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100927 Multi-core scheduler support improves the CPU scheduler's decision
928 making when dealing with multi-core CPU chips at a cost of slightly
929 increased overhead in some places. If unsure say N here.
930
931source "kernel/Kconfig.preempt"
932
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000933config UP_LATE_INIT
934 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100935 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000936
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100937config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000938 bool "Local APIC support on uniprocessors" if !PCI_MSI
939 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000940 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100941 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100942 A local APIC (Advanced Programmable Interrupt Controller) is an
943 integrated interrupt controller in the CPU. If you have a single-CPU
944 system which has a processor with a local APIC, you can say Y here to
945 enable and use it. If you say Y here even though your machine doesn't
946 have a local APIC, then the kernel will still run with no slowdown at
947 all. The local APIC supports CPU-generated self-interrupts (timer,
948 performance counters), and the NMI watchdog which detects hard
949 lockups.
950
951config X86_UP_IOAPIC
952 bool "IO-APIC support on uniprocessors"
953 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100954 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100955 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
956 SMP-capable replacement for PC-style interrupt controllers. Most
957 SMP systems and many recent uniprocessor systems have one.
958
959 If you have a single-CPU system with an IO-APIC, you can say Y here
960 to use it. If you say Y here even though your machine doesn't have
961 an IO-APIC, then the kernel will still run with no slowdown at all.
962
963config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100964 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200965 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800966 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800967 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100968
969config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000970 def_bool y
971 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100972
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200973config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
974 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200975 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100976 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200977 This option enables a workaround that fixes a source of
978 spurious interrupts. This is recommended when threaded
979 interrupt handling is used on systems where the generation of
980 superfluous "boot interrupts" cannot be disabled.
981
982 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
983 entry in the chipset's IO-APIC is masked (as, e.g. the RT
984 kernel does during interrupt handling). On chipsets where this
985 boot IRQ generation cannot be disabled, this workaround keeps
986 the original IRQ line masked so that only the equivalent "boot
987 IRQ" is delivered to the CPUs. The workaround also tells the
988 kernel to set up the IRQ handler on the boot IRQ line. In this
989 way only one interrupt is delivered to the kernel. Otherwise
990 the spurious second interrupt may cause the kernel to bring
991 down (vital) interrupt lines.
992
993 Only affects "broken" chipsets. Interrupt sharing may be
994 increased on these systems.
995
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100996config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +0200997 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +0200998 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +0200999 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001000 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001001 Machine Check support allows the processor to notify the
1002 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001003 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001004 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001005
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001006config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001007 def_bool y
1008 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001009 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001010 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001011 Additional support for intel specific MCE features such as
1012 the thermal monitor.
1013
1014config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001015 def_bool y
1016 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001017 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001018 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001019 Additional support for AMD specific MCE features such as
1020 the DRAM Error Threshold.
1021
Andi Kleen4efc0672009-04-28 19:07:31 +02001022config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001023 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001024 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001025 ---help---
1026 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001027 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001028 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001029
Andi Kleenb2762682009-02-12 13:49:31 +01001030config X86_MCE_THRESHOLD
1031 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001032 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001033
Andi Kleenea149b32009-04-29 19:31:00 +02001034config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001035 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001036 tristate "Machine check injector support"
1037 ---help---
1038 Provide support for injecting machine checks for testing purposes.
1039 If you don't know what a machine check is and you don't do kernel
1040 QA it is safe to say n.
1041
Andi Kleen4efc0672009-04-28 19:07:31 +02001042config X86_THERMAL_VECTOR
1043 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001044 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001045
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001046source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001047
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001048config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001049 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001050 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001051 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001052 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001053 This option allows user programs to put the CPU into V8086
1054 mode, which is an 80286-era approximation of 16-bit real mode.
1055
1056 Some very old versions of X and/or vbetool require this option
1057 for user mode setting. Similarly, DOSEMU will use it if
1058 available to accelerate real mode DOS programs. However, any
1059 recent version of DOSEMU, X, or vbetool should be fully
1060 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001061 fall back to software emulation. Nevertheless, if you are using
1062 a 16-bit DOS program where 16-bit performance matters, vm86
1063 mode might be faster than emulation and you might want to
1064 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001065
Ingo Molnar1e642812015-09-05 08:58:10 +02001066 Note that any app that works on a 64-bit kernel is unlikely to
1067 need this option, as 64-bit kernels don't, and can't, support
1068 V8086 mode. This option is also unrelated to 16-bit protected
1069 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001070
Ingo Molnar1e642812015-09-05 08:58:10 +02001071 Enabling this option increases the complexity of the kernel
1072 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001073
Ingo Molnar1e642812015-09-05 08:58:10 +02001074 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001075
1076config VM86
1077 bool
1078 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001079
1080config X86_16BIT
1081 bool "Enable support for 16-bit segments" if EXPERT
1082 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001083 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001084 ---help---
1085 This option is required by programs like Wine to run 16-bit
1086 protected mode legacy code on x86 processors. Disabling
1087 this option saves about 300 bytes on i386, or around 6K text
1088 plus 16K runtime memory on x86-64,
1089
1090config X86_ESPFIX32
1091 def_bool y
1092 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001093
H. Peter Anvin197725d2014-05-04 10:00:49 -07001094config X86_ESPFIX64
1095 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001096 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001097
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001098config X86_VSYSCALL_EMULATION
1099 bool "Enable vsyscall emulation" if EXPERT
1100 default y
1101 depends on X86_64
1102 ---help---
1103 This enables emulation of the legacy vsyscall page. Disabling
1104 it is roughly equivalent to booting with vsyscall=none, except
1105 that it will also disable the helpful warning if a program
1106 tries to use a vsyscall. With this option set to N, offending
1107 programs will just segfault, citing addresses of the form
1108 0xffffffffff600?00.
1109
1110 This option is required by many programs built before 2013, and
1111 care should be used even with newer programs if set to N.
1112
1113 Disabling this option saves about 7K of kernel size and
1114 possibly 4K of additional runtime pagetable memory.
1115
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001116config TOSHIBA
1117 tristate "Toshiba Laptop support"
1118 depends on X86_32
1119 ---help---
1120 This adds a driver to safely access the System Management Mode of
1121 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1122 not work on models with a Phoenix BIOS. The System Management Mode
1123 is used to set the BIOS and power saving options on Toshiba portables.
1124
1125 For information on utilities to make use of this driver see the
1126 Toshiba Linux utilities web site at:
1127 <http://www.buzzard.org.uk/toshiba/>.
1128
1129 Say Y if you intend to run this kernel on a Toshiba portable.
1130 Say N otherwise.
1131
1132config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001133 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001134 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001135 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001136 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001137 This option enables legacy /proc/i8k userspace interface in hwmon
1138 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1139 temperature and allows controlling fan speeds of Dell laptops via
1140 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1141 it reports also power and hotkey status. For fan speed control is
1142 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001143
Pali Rohár039ae582015-05-14 13:16:37 +02001144 Say Y if you intend to run this kernel on old Dell laptops or want to
1145 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001146 Say N otherwise.
1147
1148config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001149 bool "Enable X86 board specific fixups for reboot"
1150 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001151 ---help---
1152 This enables chipset and/or board specific fixups to be done
1153 in order to get reboot to work correctly. This is only needed on
1154 some combinations of hardware and BIOS. The symptom, for which
1155 this config is intended, is when reboot ends with a stalled/hung
1156 system.
1157
1158 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001159 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001160
1161 Say Y if you want to enable the fixup. Currently, it's safe to
1162 enable this option even if you don't need it.
1163 Say N otherwise.
1164
1165config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001166 bool "CPU microcode loading support"
1167 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001168 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001169 select FW_LOADER
1170 ---help---
1171 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001172 Intel and AMD processors. The Intel support is for the IA32 family,
1173 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1174 AMD support is for families 0x10 and later. You will obviously need
1175 the actual microcode binary data itself which is not shipped with
1176 the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001177
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001178 The preferred method to load microcode from a detached initrd is described
1179 in Documentation/x86/early-microcode.txt. For that you need to enable
1180 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1181 initrd for microcode blobs.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001182
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001183 In addition, you can build-in the microcode into the kernel. For that you
1184 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1185 to the CONFIG_EXTRA_FIRMWARE config option.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001186
Peter Oruba8d86f392008-07-28 18:44:21 +02001187config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001188 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001189 depends on MICROCODE
1190 default MICROCODE
1191 select FW_LOADER
1192 ---help---
1193 This options enables microcode patch loading support for Intel
1194 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001195
Alanb8989db2014-01-20 18:01:56 +00001196 For the current Intel microcode data package go to
1197 <https://downloadcenter.intel.com> and search for
1198 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001199
Peter Oruba80cc9f12008-07-28 18:44:22 +02001200config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001201 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001202 depends on MICROCODE
1203 select FW_LOADER
1204 ---help---
1205 If you select this option, microcode patch loading support for AMD
1206 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001207
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001208config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001209 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001210 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001211
1212config X86_MSR
1213 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001214 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001215 This device gives privileged processes access to the x86
1216 Model-Specific Registers (MSRs). It is a character device with
1217 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1218 MSR accesses are directed to a specific CPU on multi-processor
1219 systems.
1220
1221config X86_CPUID
1222 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001223 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001224 This device gives processes access to the x86 CPUID instruction to
1225 be executed on a specific processor. It is a character device
1226 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1227 /dev/cpu/31/cpuid.
1228
1229choice
1230 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001231 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001232 depends on X86_32
1233
1234config NOHIGHMEM
1235 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001236 ---help---
1237 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1238 However, the address space of 32-bit x86 processors is only 4
1239 Gigabytes large. That means that, if you have a large amount of
1240 physical memory, not all of it can be "permanently mapped" by the
1241 kernel. The physical memory that's not permanently mapped is called
1242 "high memory".
1243
1244 If you are compiling a kernel which will never run on a machine with
1245 more than 1 Gigabyte total physical RAM, answer "off" here (default
1246 choice and suitable for most users). This will result in a "3GB/1GB"
1247 split: 3GB are mapped so that each process sees a 3GB virtual memory
1248 space and the remaining part of the 4GB virtual memory space is used
1249 by the kernel to permanently map as much physical memory as
1250 possible.
1251
1252 If the machine has between 1 and 4 Gigabytes physical RAM, then
1253 answer "4GB" here.
1254
1255 If more than 4 Gigabytes is used then answer "64GB" here. This
1256 selection turns Intel PAE (Physical Address Extension) mode on.
1257 PAE implements 3-level paging on IA32 processors. PAE is fully
1258 supported by Linux, PAE mode is implemented on all recent Intel
1259 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1260 then the kernel will not boot on CPUs that don't support PAE!
1261
1262 The actual amount of total physical memory will either be
1263 auto detected or can be forced by using a kernel command line option
1264 such as "mem=256M". (Try "man bootparam" or see the documentation of
1265 your boot loader (lilo or loadlin) about how to pass options to the
1266 kernel at boot time.)
1267
1268 If unsure, say "off".
1269
1270config HIGHMEM4G
1271 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001272 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001273 Select this if you have a 32-bit processor and between 1 and 4
1274 gigabytes of physical RAM.
1275
1276config HIGHMEM64G
1277 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001278 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001279 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001280 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001281 Select this if you have a 32-bit processor and more than 4
1282 gigabytes of physical RAM.
1283
1284endchoice
1285
1286choice
David Rientjes6a108a12011-01-20 14:44:16 -08001287 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001288 default VMSPLIT_3G
1289 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001290 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001291 Select the desired split between kernel and user memory.
1292
1293 If the address range available to the kernel is less than the
1294 physical memory installed, the remaining memory will be available
1295 as "high memory". Accessing high memory is a little more costly
1296 than low memory, as it needs to be mapped into the kernel first.
1297 Note that increasing the kernel address space limits the range
1298 available to user programs, making the address space there
1299 tighter. Selecting anything other than the default 3G/1G split
1300 will also likely make your kernel incompatible with binary-only
1301 kernel modules.
1302
1303 If you are not absolutely sure what you are doing, leave this
1304 option alone!
1305
1306 config VMSPLIT_3G
1307 bool "3G/1G user/kernel split"
1308 config VMSPLIT_3G_OPT
1309 depends on !X86_PAE
1310 bool "3G/1G user/kernel split (for full 1G low memory)"
1311 config VMSPLIT_2G
1312 bool "2G/2G user/kernel split"
1313 config VMSPLIT_2G_OPT
1314 depends on !X86_PAE
1315 bool "2G/2G user/kernel split (for full 2G low memory)"
1316 config VMSPLIT_1G
1317 bool "1G/3G user/kernel split"
1318endchoice
1319
1320config PAGE_OFFSET
1321 hex
1322 default 0xB0000000 if VMSPLIT_3G_OPT
1323 default 0x80000000 if VMSPLIT_2G
1324 default 0x78000000 if VMSPLIT_2G_OPT
1325 default 0x40000000 if VMSPLIT_1G
1326 default 0xC0000000
1327 depends on X86_32
1328
1329config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001330 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001331 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001332
1333config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001334 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001335 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001336 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001337 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001338 PAE is required for NX support, and furthermore enables
1339 larger swapspace support for non-overcommit purposes. It
1340 has the cost of more pagetable lookup overhead, and also
1341 consumes more pagetable space per process.
1342
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001343config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001344 def_bool y
1345 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001346
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001347config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001348 def_bool y
1349 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001350
Ingo Molnar10971ab2015-03-05 08:18:23 +01001351config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001352 def_bool y
1353 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001354 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001355 Certain kernel features effectively disable kernel
1356 linear 1 GB mappings (even if the CPU otherwise
1357 supports them), so don't confuse the user by printing
1358 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001359
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001360# Common NUMA Features
1361config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001362 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001363 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001364 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1365 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001366 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001367 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001368
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001369 The kernel will try to allocate memory used by a CPU on the
1370 local memory controller of the CPU and add some more
1371 NUMA awareness to the kernel.
1372
Ingo Molnarc280ea52008-11-08 13:29:45 +01001373 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001374 (or later), AMD Opteron, or EM64T NUMA.
1375
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001376 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001377 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001378
1379 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001380
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001381config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001382 def_bool y
1383 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001384 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001385 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001386 Enable AMD NUMA node topology detection. You should say Y here if
1387 you have a multi processor AMD system. This uses an old method to
1388 read the NUMA configuration directly from the builtin Northbridge
1389 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1390 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001391
1392config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001393 def_bool y
1394 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001395 depends on X86_64 && NUMA && ACPI && PCI
1396 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001397 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001398 Enable ACPI SRAT based node topology detection.
1399
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001400# Some NUMA nodes have memory ranges that span
1401# other nodes. Even though a pfn is valid and
1402# between a node's start and end pfns, it may not
1403# reside on that node. See memmap_init_zone()
1404# for details.
1405config NODES_SPAN_OTHER_NODES
1406 def_bool y
1407 depends on X86_64_ACPI_NUMA
1408
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001409config NUMA_EMU
1410 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001411 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001412 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001413 Enable NUMA emulation. A flat machine will be split
1414 into virtual nodes when booted with "numa=fake=N", where N is the
1415 number of nodes. This is only useful for debugging.
1416
1417config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001418 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001419 range 1 10
1420 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001421 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001422 default "3"
1423 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001424 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001425 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001426 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001427
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001428config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001429 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001430 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001431
1432config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001433 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001434 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001435
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001436config ARCH_FLATMEM_ENABLE
1437 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001438 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001439
1440config ARCH_DISCONTIGMEM_ENABLE
1441 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001442 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001443
1444config ARCH_DISCONTIGMEM_DEFAULT
1445 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001446 depends on NUMA && X86_32
1447
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001448config ARCH_SPARSEMEM_ENABLE
1449 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001450 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001451 select SPARSEMEM_STATIC if X86_32
1452 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1453
Tejun Heo3b166512011-04-01 11:15:12 +02001454config ARCH_SPARSEMEM_DEFAULT
1455 def_bool y
1456 depends on X86_64
1457
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001458config ARCH_SELECT_MEMORY_MODEL
1459 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001460 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001461
1462config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001463 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001464 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001465 help
1466 This option enables a sysfs memory/probe interface for testing.
1467 See Documentation/memory-hotplug.txt for more information.
1468 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001469
Tejun Heo3b166512011-04-01 11:15:12 +02001470config ARCH_PROC_KCORE_TEXT
1471 def_bool y
1472 depends on X86_64 && PROC_KCORE
1473
Avi Kivitya29815a2010-01-10 16:28:09 +02001474config ILLEGAL_POINTER_VALUE
1475 hex
1476 default 0 if X86_32
1477 default 0xdead000000000000 if X86_64
1478
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001479source "mm/Kconfig"
1480
Dan Williams7a678322015-08-19 00:34:34 -04001481config X86_PMEM_LEGACY_DEVICE
1482 bool
1483
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001484config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001485 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001486 depends on PHYS_ADDR_T_64BIT
1487 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001488 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001489 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001490 help
1491 Treat memory marked using the non-standard e820 type of 12 as used
1492 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1493 The kernel will offer these regions to the 'pmem' driver so
1494 they can be used for persistent storage.
1495
1496 Say Y if unsure.
1497
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001498config HIGHPTE
1499 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001500 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001501 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001502 The VM uses one page table entry for each page of physical memory.
1503 For systems with a lot of RAM, this can be wasteful of precious
1504 low memory. Setting this option will put user-space page table
1505 entries in high memory.
1506
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001507config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001508 bool "Check for low memory corruption"
1509 ---help---
1510 Periodically check for memory corruption in low memory, which
1511 is suspected to be caused by BIOS. Even when enabled in the
1512 configuration, it is disabled at runtime. Enable it by
1513 setting "memory_corruption_check=1" on the kernel command
1514 line. By default it scans the low 64k of memory every 60
1515 seconds; see the memory_corruption_check_size and
1516 memory_corruption_check_period parameters in
1517 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001518
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001519 When enabled with the default parameters, this option has
1520 almost no overhead, as it reserves a relatively small amount
1521 of memory and scans it infrequently. It both detects corruption
1522 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001523
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001524 It is, however, intended as a diagnostic tool; if repeatable
1525 BIOS-originated corruption always affects the same memory,
1526 you can use memmap= to prevent the kernel from using that
1527 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001528
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001529config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001530 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001531 depends on X86_CHECK_BIOS_CORRUPTION
1532 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001533 ---help---
1534 Set whether the default state of memory_corruption_check is
1535 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001536
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001537config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001538 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1539 default 64
1540 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001541 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001542 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001543
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001544 The first page contains BIOS data structures that the kernel
1545 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001546
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001547 By default we reserve the first 64K of physical RAM, as a
1548 number of BIOSes are known to corrupt that memory range
1549 during events such as suspend/resume or monitor cable
1550 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001551
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001552 You can set this to 4 if you are absolutely sure that you
1553 trust the BIOS to get all its memory reservations and usages
1554 right. If you know your BIOS have problems beyond the
1555 default 64K area, you can set this to 640 to avoid using the
1556 entire low memory range.
1557
1558 If you have doubts about the BIOS (e.g. suspend/resume does
1559 not work or there's kernel crashes after certain hardware
1560 hotplug events) then you might want to enable
1561 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1562 typical corruption patterns.
1563
1564 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001565
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001566config MATH_EMULATION
1567 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001568 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001569 prompt "Math emulation" if X86_32
1570 ---help---
1571 Linux can emulate a math coprocessor (used for floating point
1572 operations) if you don't have one. 486DX and Pentium processors have
1573 a math coprocessor built in, 486SX and 386 do not, unless you added
1574 a 487DX or 387, respectively. (The messages during boot time can
1575 give you some hints here ["man dmesg"].) Everyone needs either a
1576 coprocessor or this emulation.
1577
1578 If you don't have a math coprocessor, you need to say Y here; if you
1579 say Y here even though you have a coprocessor, the coprocessor will
1580 be used nevertheless. (This behavior can be changed with the kernel
1581 command line option "no387", which comes handy if your coprocessor
1582 is broken. Try "man bootparam" or see the documentation of your boot
1583 loader (lilo or loadlin) about how to pass options to the kernel at
1584 boot time.) This means that it is a good idea to say Y here if you
1585 intend to use this kernel on different machines.
1586
1587 More information about the internals of the Linux math coprocessor
1588 emulation can be found in <file:arch/x86/math-emu/README>.
1589
1590 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1591 kernel, it won't hurt.
1592
1593config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001594 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001595 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001596 ---help---
1597 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1598 the Memory Type Range Registers (MTRRs) may be used to control
1599 processor access to memory ranges. This is most useful if you have
1600 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1601 allows bus write transfers to be combined into a larger transfer
1602 before bursting over the PCI/AGP bus. This can increase performance
1603 of image write operations 2.5 times or more. Saying Y here creates a
1604 /proc/mtrr file which may be used to manipulate your processor's
1605 MTRRs. Typically the X server should use this.
1606
1607 This code has a reasonably generic interface so that similar
1608 control registers on other processors can be easily supported
1609 as well:
1610
1611 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1612 Registers (ARRs) which provide a similar functionality to MTRRs. For
1613 these, the ARRs are used to emulate the MTRRs.
1614 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1615 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1616 write-combining. All of these processors are supported by this code
1617 and it makes sense to say Y here if you have one of them.
1618
1619 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1620 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1621 can lead to all sorts of problems, so it's good to say Y here.
1622
1623 You can safely say Y even if your machine doesn't have MTRRs, you'll
1624 just add about 9 KB to your kernel.
1625
Randy Dunlap7225e752008-07-26 17:54:22 -07001626 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001627
Yinghai Lu95ffa242008-04-29 03:52:33 -07001628config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001629 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001630 prompt "MTRR cleanup support"
1631 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001632 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001633 Convert MTRR layout from continuous to discrete, so X drivers can
1634 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001635
Thomas Gleixneraba37282008-07-15 14:48:48 +02001636 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001637 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001638 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001639
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001640 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001641
1642config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001643 int "MTRR cleanup enable value (0-1)"
1644 range 0 1
1645 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001646 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001647 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001648 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001649
Yinghai Lu12031a62008-05-02 02:40:22 -07001650config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1651 int "MTRR cleanup spare reg num (0-7)"
1652 range 0 7
1653 default "1"
1654 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001655 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001656 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001657 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001658
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001659config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001660 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001661 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001662 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001663 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001664 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001665
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001666 PATs are the modern equivalents of MTRRs and are much more
1667 flexible than MTRRs.
1668
1669 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001670 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001671
1672 If unsure, say Y.
1673
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001674config ARCH_USES_PG_UNCACHED
1675 def_bool y
1676 depends on X86_PAT
1677
H. Peter Anvin628c6242011-07-31 13:59:29 -07001678config ARCH_RANDOM
1679 def_bool y
1680 prompt "x86 architectural random number generator" if EXPERT
1681 ---help---
1682 Enable the x86 architectural RDRAND instruction
1683 (Intel Bull Mountain technology) to generate random numbers.
1684 If supported, this is a high bandwidth, cryptographically
1685 secure hardware random number generator.
1686
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001687config X86_SMAP
1688 def_bool y
1689 prompt "Supervisor Mode Access Prevention" if EXPERT
1690 ---help---
1691 Supervisor Mode Access Prevention (SMAP) is a security
1692 feature in newer Intel processors. There is a small
1693 performance cost if this enabled and turned on; there is
1694 also a small increase in the kernel size if this is enabled.
1695
1696 If unsure, say Y.
1697
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001698config X86_INTEL_MPX
1699 prompt "Intel MPX (Memory Protection Extensions)"
1700 def_bool n
1701 depends on CPU_SUP_INTEL
1702 ---help---
1703 MPX provides hardware features that can be used in
1704 conjunction with compiler-instrumented code to check
1705 memory references. It is designed to detect buffer
1706 overflow or underflow bugs.
1707
1708 This option enables running applications which are
1709 instrumented or otherwise use MPX. It does not use MPX
1710 itself inside the kernel or to protect the kernel
1711 against bad memory references.
1712
1713 Enabling this option will make the kernel larger:
1714 ~8k of kernel text and 36 bytes of data on a 64-bit
1715 defconfig. It adds a long to the 'mm_struct' which
1716 will increase the kernel memory overhead of each
1717 process and adds some branches to paths used during
1718 exec() and munmap().
1719
1720 For details, see Documentation/x86/intel_mpx.txt
1721
1722 If unsure, say N.
1723
Dave Hansen35e97792016-02-12 13:02:00 -08001724config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001725 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001726 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001727 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001728 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001729 ---help---
1730 Memory Protection Keys provides a mechanism for enforcing
1731 page-based protections, but without requiring modification of the
1732 page tables when an application changes protection domains.
1733
1734 For details, see Documentation/x86/protection-keys.txt
1735
1736 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001737
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001738config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001739 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001740 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001741 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001742 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001743 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001744 This enables the kernel to use EFI runtime services that are
1745 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001746
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001747 This option is only useful on systems that have EFI firmware.
1748 In addition, you should use the latest ELILO loader available
1749 at <http://elilo.sourceforge.net> in order to take advantage
1750 of EFI runtime services. However, even with this option, the
1751 resultant kernel should continue to boot on existing non-EFI
1752 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001753
Matt Fleming291f3632011-12-12 21:27:52 +00001754config EFI_STUB
1755 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001756 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001757 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001758 ---help---
1759 This kernel feature allows a bzImage to be loaded directly
1760 by EFI firmware without the use of a bootloader.
1761
Roy Franz4172fe22013-09-22 15:45:25 -07001762 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001763
Matt Fleming7d453ee2014-01-10 18:52:06 +00001764config EFI_MIXED
1765 bool "EFI mixed-mode support"
1766 depends on EFI_STUB && X86_64
1767 ---help---
1768 Enabling this feature allows a 64-bit kernel to be booted
1769 on a 32-bit firmware, provided that your CPU supports 64-bit
1770 mode.
1771
1772 Note that it is not possible to boot a mixed-mode enabled
1773 kernel via the EFI boot stub - a bootloader that supports
1774 the EFI handover protocol must be used.
1775
1776 If unsure, say N.
1777
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001778config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001779 def_bool y
1780 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001781 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001782 This kernel feature is useful for number crunching applications
1783 that may need to compute untrusted bytecode during their
1784 execution. By using pipes or other transports made available to
1785 the process as file descriptors supporting the read/write
1786 syscalls, it's possible to isolate those applications in
1787 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001788 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001789 and the task is only allowed to execute a few safe syscalls
1790 defined by each seccomp mode.
1791
1792 If unsure, say Y. Only embedded should say N here.
1793
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001794source kernel/Kconfig.hz
1795
1796config KEXEC
1797 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001798 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001799 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001800 kexec is a system call that implements the ability to shutdown your
1801 current kernel, and to start another kernel. It is like a reboot
1802 but it is independent of the system firmware. And like a reboot
1803 you can start any kernel with it, not just Linux.
1804
1805 The name comes from the similarity to the exec system call.
1806
1807 It is an ongoing process to be certain the hardware in a machine
1808 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001809 initially work for you. As of this writing the exact hardware
1810 interface is strongly in flux, so no good recommendation can be
1811 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001812
Vivek Goyal74ca3172014-08-29 15:18:46 -07001813config KEXEC_FILE
1814 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001815 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001816 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001817 depends on X86_64
1818 depends on CRYPTO=y
1819 depends on CRYPTO_SHA256=y
1820 ---help---
1821 This is new version of kexec system call. This system call is
1822 file based and takes file descriptors as system call argument
1823 for kernel and initramfs as opposed to list of segments as
1824 accepted by previous system call.
1825
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001826config KEXEC_VERIFY_SIG
1827 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001828 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001829 ---help---
1830 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001831 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001832
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001833 In addition to that option, you need to enable signature
1834 verification for the corresponding kernel image type being
1835 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001836
1837config KEXEC_BZIMAGE_VERIFY_SIG
1838 bool "Enable bzImage signature verification support"
1839 depends on KEXEC_VERIFY_SIG
1840 depends on SIGNED_PE_FILE_VERIFICATION
1841 select SYSTEM_TRUSTED_KEYRING
1842 ---help---
1843 Enable bzImage signature verification support.
1844
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001845config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001846 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001847 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001848 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001849 Generate crash dump after being started by kexec.
1850 This should be normally only set in special crash dump kernels
1851 which are loaded in the main kernel with kexec-tools into
1852 a specially reserved region and then later executed after
1853 a crash by kdump/kexec. The crash dump kernel must be compiled
1854 to a memory address not used by the main kernel or BIOS using
1855 PHYSICAL_START, or it must be built as a relocatable image
1856 (CONFIG_RELOCATABLE=y).
1857 For more details see Documentation/kdump/kdump.txt
1858
Huang Ying3ab83522008-07-25 19:45:07 -07001859config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001860 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001861 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001862 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001863 Jump between original kernel and kexeced kernel and invoke
1864 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001865
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001866config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001867 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001868 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001869 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001870 This gives the physical address where the kernel is loaded.
1871
1872 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1873 bzImage will decompress itself to above physical address and
1874 run from there. Otherwise, bzImage will run from the address where
1875 it has been loaded by the boot loader and will ignore above physical
1876 address.
1877
1878 In normal kdump cases one does not have to set/change this option
1879 as now bzImage can be compiled as a completely relocatable image
1880 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1881 address. This option is mainly useful for the folks who don't want
1882 to use a bzImage for capturing the crash dump and want to use a
1883 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1884 to be specifically compiled to run from a specific memory area
1885 (normally a reserved region) and this option comes handy.
1886
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001887 So if you are using bzImage for capturing the crash dump,
1888 leave the value here unchanged to 0x1000000 and set
1889 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1890 for capturing the crash dump change this value to start of
1891 the reserved region. In other words, it can be set based on
1892 the "X" value as specified in the "crashkernel=YM@XM"
1893 command line boot parameter passed to the panic-ed
1894 kernel. Please take a look at Documentation/kdump/kdump.txt
1895 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001896
1897 Usage of bzImage for capturing the crash dump is recommended as
1898 one does not have to build two kernels. Same kernel can be used
1899 as production kernel and capture kernel. Above option should have
1900 gone away after relocatable bzImage support is introduced. But it
1901 is present because there are users out there who continue to use
1902 vmlinux for dump capture. This option should go away down the
1903 line.
1904
1905 Don't change this unless you know what you are doing.
1906
1907config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001908 bool "Build a relocatable kernel"
1909 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001910 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001911 This builds a kernel image that retains relocation information
1912 so it can be loaded someplace besides the default 1MB.
1913 The relocations tend to make the kernel binary about 10% larger,
1914 but are discarded at runtime.
1915
1916 One use is for the kexec on panic case where the recovery kernel
1917 must live at a different physical address than the primary
1918 kernel.
1919
1920 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1921 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001922 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001923
Kees Cook8ab38202013-10-10 17:18:14 -07001924config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07001925 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07001926 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001927 default n
1928 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07001929 In support of Kernel Address Space Layout Randomization (KASLR),
1930 this randomizes the physical address at which the kernel image
1931 is decompressed and the virtual address where the kernel
1932 image is mapped, as a security feature that deters exploit
1933 attempts relying on knowledge of the location of kernel
1934 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07001935
Baoquan Hee8581e32016-04-20 13:55:43 -07001936 The kernel physical and virtual address can be randomized
1937 from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
1938 using RANDOMIZE_BASE reduces the memory space available to
1939 kernel modules from 1.5GB to 1GB.)
Kees Cook8ab38202013-10-10 17:18:14 -07001940
Baoquan Hee8581e32016-04-20 13:55:43 -07001941 Entropy is generated using the RDRAND instruction if it is
1942 supported. If RDTSC is supported, its value is mixed into
1943 the entropy pool as well. If neither RDRAND nor RDTSC are
1944 supported, then entropy is read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001945
Baoquan Hee8581e32016-04-20 13:55:43 -07001946 Since the kernel is built using 2GB addressing, and
1947 PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
1948 entropy is theoretically possible. Currently, with the
1949 default value for PHYSICAL_ALIGN and due to page table
1950 layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
Kees Cookda2b6fb2013-12-10 12:27:45 -08001951
Baoquan Hee8581e32016-04-20 13:55:43 -07001952 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1953 time. To enable it, boot with "kaslr" on the kernel command
1954 line (which will also disable hibernation).
Kees Cook6145cfe2013-10-10 17:18:18 -07001955
Baoquan Hee8581e32016-04-20 13:55:43 -07001956 If unsure, say N.
Kees Cook8ab38202013-10-10 17:18:14 -07001957
1958# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001959config X86_NEED_RELOCS
1960 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001961 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001962
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001963config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001964 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001965 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001966 range 0x2000 0x1000000 if X86_32
1967 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001968 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001969 This value puts the alignment restrictions on physical address
1970 where kernel is loaded and run from. Kernel is compiled for an
1971 address which meets above alignment restriction.
1972
1973 If bootloader loads the kernel at a non-aligned address and
1974 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1975 address aligned to above value and run from there.
1976
1977 If bootloader loads the kernel at a non-aligned address and
1978 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1979 load address and decompress itself to the address it has been
1980 compiled for and run from there. The address for which kernel is
1981 compiled already meets above alignment restrictions. Hence the
1982 end result is that kernel runs from a physical address meeting
1983 above alignment restrictions.
1984
Kees Cooka0215062013-07-08 09:15:17 -07001985 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1986 this value must be a multiple of 0x200000.
1987
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001988 Don't change this unless you know what you are doing.
1989
1990config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001991 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001992 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001993 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001994 Say Y here to allow turning CPUs off and on. CPUs can be
1995 controlled through /sys/devices/system/cpu.
1996 ( Note: power management support will enable this option
1997 automatically on SMP systems. )
1998 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001999
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002000config BOOTPARAM_HOTPLUG_CPU0
2001 bool "Set default setting of cpu0_hotpluggable"
2002 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002003 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002004 ---help---
2005 Set whether default state of cpu0_hotpluggable is on or off.
2006
2007 Say Y here to enable CPU0 hotplug by default. If this switch
2008 is turned on, there is no need to give cpu0_hotplug kernel
2009 parameter and the CPU0 hotplug feature is enabled by default.
2010
2011 Please note: there are two known CPU0 dependencies if you want
2012 to enable the CPU0 hotplug feature either by this switch or by
2013 cpu0_hotplug kernel parameter.
2014
2015 First, resume from hibernate or suspend always starts from CPU0.
2016 So hibernate and suspend are prevented if CPU0 is offline.
2017
2018 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2019 offline if any interrupt can not migrate out of CPU0. There may
2020 be other CPU0 dependencies.
2021
2022 Please make sure the dependencies are under your control before
2023 you enable this feature.
2024
2025 Say N if you don't want to enable CPU0 hotplug feature by default.
2026 You still can enable the CPU0 hotplug feature at boot by kernel
2027 parameter cpu0_hotplug.
2028
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002029config DEBUG_HOTPLUG_CPU0
2030 def_bool n
2031 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002032 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002033 ---help---
2034 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2035 soon as possible and boots up userspace with CPU0 offlined. User
2036 can online CPU0 back after boot time.
2037
2038 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2039 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2040 compilation or giving cpu0_hotplug kernel parameter at boot.
2041
2042 If unsure, say N.
2043
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002044config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002045 def_bool n
2046 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002047 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002048 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002049 Certain buggy versions of glibc will crash if they are
2050 presented with a 32-bit vDSO that is not mapped at the address
2051 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002052
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002053 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2054 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2055 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2056 the only released version with the bug, but OpenSUSE 9
2057 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002058
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002059 The symptom of the bug is that everything crashes on startup, saying:
2060 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2061
2062 Saying Y here changes the default value of the vdso32 boot
2063 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2064 This works around the glibc bug but hurts performance.
2065
2066 If unsure, say N: if you are compiling your own kernel, you
2067 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002068
Kees Cook3dc33bd2015-08-12 17:55:19 -07002069choice
2070 prompt "vsyscall table for legacy applications"
2071 depends on X86_64
2072 default LEGACY_VSYSCALL_EMULATE
2073 help
2074 Legacy user code that does not know how to find the vDSO expects
2075 to be able to issue three syscalls by calling fixed addresses in
2076 kernel space. Since this location is not randomized with ASLR,
2077 it can be used to assist security vulnerability exploitation.
2078
2079 This setting can be changed at boot time via the kernel command
2080 line parameter vsyscall=[native|emulate|none].
2081
2082 On a system with recent enough glibc (2.14 or newer) and no
2083 static binaries, you can say None without a performance penalty
2084 to improve security.
2085
2086 If unsure, select "Emulate".
2087
2088 config LEGACY_VSYSCALL_NATIVE
2089 bool "Native"
2090 help
2091 Actual executable code is located in the fixed vsyscall
2092 address mapping, implementing time() efficiently. Since
2093 this makes the mapping executable, it can be used during
2094 security vulnerability exploitation (traditionally as
2095 ROP gadgets). This configuration is not recommended.
2096
2097 config LEGACY_VSYSCALL_EMULATE
2098 bool "Emulate"
2099 help
2100 The kernel traps and emulates calls into the fixed
2101 vsyscall address mapping. This makes the mapping
2102 non-executable, but it still contains known contents,
2103 which could be used in certain rare security vulnerability
2104 exploits. This configuration is recommended when userspace
2105 still uses the vsyscall area.
2106
2107 config LEGACY_VSYSCALL_NONE
2108 bool "None"
2109 help
2110 There will be no vsyscall mapping at all. This will
2111 eliminate any risk of ASLR bypass due to the vsyscall
2112 fixed address mapping. Attempts to use the vsyscalls
2113 will be reported to dmesg, so that either old or
2114 malicious userspace programs can be identified.
2115
2116endchoice
2117
Tim Bird516cbf32008-08-12 12:52:36 -07002118config CMDLINE_BOOL
2119 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002120 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002121 Allow for specifying boot arguments to the kernel at
2122 build time. On some systems (e.g. embedded ones), it is
2123 necessary or convenient to provide some or all of the
2124 kernel boot arguments with the kernel itself (that is,
2125 to not rely on the boot loader to provide them.)
2126
2127 To compile command line arguments into the kernel,
2128 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002129 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002130
2131 Systems with fully functional boot loaders (i.e. non-embedded)
2132 should leave this option set to 'N'.
2133
2134config CMDLINE
2135 string "Built-in kernel command string"
2136 depends on CMDLINE_BOOL
2137 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002138 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002139 Enter arguments here that should be compiled into the kernel
2140 image and used at boot time. If the boot loader provides a
2141 command line at boot time, it is appended to this string to
2142 form the full kernel command line, when the system boots.
2143
2144 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2145 change this behavior.
2146
2147 In most cases, the command line (whether built-in or provided
2148 by the boot loader) should specify the device for the root
2149 file system.
2150
2151config CMDLINE_OVERRIDE
2152 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002153 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002154 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002155 Set this option to 'Y' to have the kernel ignore the boot loader
2156 command line, and use ONLY the built-in command line.
2157
2158 This is used to work around broken boot loaders. This should
2159 be set to 'N' under normal conditions.
2160
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002161config MODIFY_LDT_SYSCALL
2162 bool "Enable the LDT (local descriptor table)" if EXPERT
2163 default y
2164 ---help---
2165 Linux can allow user programs to install a per-process x86
2166 Local Descriptor Table (LDT) using the modify_ldt(2) system
2167 call. This is required to run 16-bit or segmented code such as
2168 DOSEMU or some Wine programs. It is also used by some very old
2169 threading libraries.
2170
2171 Enabling this feature adds a small amount of overhead to
2172 context switches and increases the low-level kernel attack
2173 surface. Disabling it removes the modify_ldt(2) system call.
2174
2175 Saying 'N' here may make sense for embedded or server kernels.
2176
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002177source "kernel/livepatch/Kconfig"
2178
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002179endmenu
2180
2181config ARCH_ENABLE_MEMORY_HOTPLUG
2182 def_bool y
2183 depends on X86_64 || (X86_32 && HIGHMEM)
2184
Gary Hade35551052008-10-31 10:52:03 -07002185config ARCH_ENABLE_MEMORY_HOTREMOVE
2186 def_bool y
2187 depends on MEMORY_HOTPLUG
2188
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002189config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002190 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002191 depends on NUMA
2192
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002193config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2194 def_bool y
2195 depends on X86_64 || X86_PAE
2196
Naoya Horiguchic177c812014-06-04 16:05:35 -07002197config ARCH_ENABLE_HUGEPAGE_MIGRATION
2198 def_bool y
2199 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2200
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002201menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002202
2203config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002204 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002205 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002206
2207source "kernel/power/Kconfig"
2208
2209source "drivers/acpi/Kconfig"
2210
Feng Tangefafc8b2009-08-14 15:23:29 -04002211source "drivers/sfi/Kconfig"
2212
Andi Kleena6b68072008-01-30 13:32:49 +01002213config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002214 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002215 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002216
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002217menuconfig APM
2218 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002219 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002220 ---help---
2221 APM is a BIOS specification for saving power using several different
2222 techniques. This is mostly useful for battery powered laptops with
2223 APM compliant BIOSes. If you say Y here, the system time will be
2224 reset after a RESUME operation, the /proc/apm device will provide
2225 battery status information, and user-space programs will receive
2226 notification of APM "events" (e.g. battery status change).
2227
2228 If you select "Y" here, you can disable actual use of the APM
2229 BIOS by passing the "apm=off" option to the kernel at boot time.
2230
2231 Note that the APM support is almost completely disabled for
2232 machines with more than one CPU.
2233
2234 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002235 and more information, read <file:Documentation/power/apm-acpi.txt>
2236 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002237 <http://www.tldp.org/docs.html#howto>.
2238
2239 This driver does not spin down disk drives (see the hdparm(8)
2240 manpage ("man 8 hdparm") for that), and it doesn't turn off
2241 VESA-compliant "green" monitors.
2242
2243 This driver does not support the TI 4000M TravelMate and the ACER
2244 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2245 desktop machines also don't have compliant BIOSes, and this driver
2246 may cause those machines to panic during the boot phase.
2247
2248 Generally, if you don't have a battery in your machine, there isn't
2249 much point in using this driver and you should say N. If you get
2250 random kernel OOPSes or reboots that don't seem to be related to
2251 anything, try disabling/enabling this option (or disabling/enabling
2252 APM in your BIOS).
2253
2254 Some other things you should try when experiencing seemingly random,
2255 "weird" problems:
2256
2257 1) make sure that you have enough swap space and that it is
2258 enabled.
2259 2) pass the "no-hlt" option to the kernel
2260 3) switch on floating point emulation in the kernel and pass
2261 the "no387" option to the kernel
2262 4) pass the "floppy=nodma" option to the kernel
2263 5) pass the "mem=4M" option to the kernel (thereby disabling
2264 all but the first 4 MB of RAM)
2265 6) make sure that the CPU is not over clocked.
2266 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2267 8) disable the cache from your BIOS settings
2268 9) install a fan for the video card or exchange video RAM
2269 10) install a better fan for the CPU
2270 11) exchange RAM chips
2271 12) exchange the motherboard.
2272
2273 To compile this driver as a module, choose M here: the
2274 module will be called apm.
2275
2276if APM
2277
2278config APM_IGNORE_USER_SUSPEND
2279 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002280 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002281 This option will ignore USER SUSPEND requests. On machines with a
2282 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2283 series notebooks, it is necessary to say Y because of a BIOS bug.
2284
2285config APM_DO_ENABLE
2286 bool "Enable PM at boot time"
2287 ---help---
2288 Enable APM features at boot time. From page 36 of the APM BIOS
2289 specification: "When disabled, the APM BIOS does not automatically
2290 power manage devices, enter the Standby State, enter the Suspend
2291 State, or take power saving steps in response to CPU Idle calls."
2292 This driver will make CPU Idle calls when Linux is idle (unless this
2293 feature is turned off -- see "Do CPU IDLE calls", below). This
2294 should always save battery power, but more complicated APM features
2295 will be dependent on your BIOS implementation. You may need to turn
2296 this option off if your computer hangs at boot time when using APM
2297 support, or if it beeps continuously instead of suspending. Turn
2298 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2299 T400CDT. This is off by default since most machines do fine without
2300 this feature.
2301
2302config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002303 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002304 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002305 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002306 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2307 On some machines, this can activate improved power savings, such as
2308 a slowed CPU clock rate, when the machine is idle. These idle calls
2309 are made after the idle loop has run for some length of time (e.g.,
2310 333 mS). On some machines, this will cause a hang at boot time or
2311 whenever the CPU becomes idle. (On machines with more than one CPU,
2312 this option does nothing.)
2313
2314config APM_DISPLAY_BLANK
2315 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002316 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002317 Enable console blanking using the APM. Some laptops can use this to
2318 turn off the LCD backlight when the screen blanker of the Linux
2319 virtual console blanks the screen. Note that this is only used by
2320 the virtual console screen blanker, and won't turn off the backlight
2321 when using the X Window system. This also doesn't have anything to
2322 do with your VESA-compliant power-saving monitor. Further, this
2323 option doesn't work for all laptops -- it might not turn off your
2324 backlight at all, or it might print a lot of errors to the console,
2325 especially if you are using gpm.
2326
2327config APM_ALLOW_INTS
2328 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002329 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002330 Normally we disable external interrupts while we are making calls to
2331 the APM BIOS as a measure to lessen the effects of a badly behaving
2332 BIOS implementation. The BIOS should reenable interrupts if it
2333 needs to. Unfortunately, some BIOSes do not -- especially those in
2334 many of the newer IBM Thinkpads. If you experience hangs when you
2335 suspend, try setting this to Y. Otherwise, say N.
2336
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002337endif # APM
2338
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002339source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002340
2341source "drivers/cpuidle/Kconfig"
2342
Andy Henroid27471fd2008-10-09 11:45:22 -07002343source "drivers/idle/Kconfig"
2344
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002345endmenu
2346
2347
2348menu "Bus options (PCI etc.)"
2349
2350config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002351 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002352 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002353 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002354 Find out whether you have a PCI motherboard. PCI is the name of a
2355 bus system, i.e. the way the CPU talks to the other stuff inside
2356 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2357 VESA. If you have PCI, say Y, otherwise N.
2358
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002359choice
2360 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002361 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002362 default PCI_GOANY
2363 ---help---
2364 On PCI systems, the BIOS can be used to detect the PCI devices and
2365 determine their configuration. However, some old PCI motherboards
2366 have BIOS bugs and may crash if this is done. Also, some embedded
2367 PCI-based systems don't have any BIOS at all. Linux can also try to
2368 detect the PCI hardware directly without using the BIOS.
2369
2370 With this option, you can specify how Linux should detect the
2371 PCI devices. If you choose "BIOS", the BIOS will be used,
2372 if you choose "Direct", the BIOS won't be used, and if you
2373 choose "MMConfig", then PCI Express MMCONFIG will be used.
2374 If you choose "Any", the kernel will try MMCONFIG, then the
2375 direct access method and falls back to the BIOS if that doesn't
2376 work. If unsure, go with the default, which is "Any".
2377
2378config PCI_GOBIOS
2379 bool "BIOS"
2380
2381config PCI_GOMMCONFIG
2382 bool "MMConfig"
2383
2384config PCI_GODIRECT
2385 bool "Direct"
2386
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002387config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002388 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002389 depends on OLPC
2390
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002391config PCI_GOANY
2392 bool "Any"
2393
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002394endchoice
2395
2396config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002397 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002398 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002399
2400# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2401config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002402 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002403 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002404
2405config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002406 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002407 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002408
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002409config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002410 def_bool y
2411 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002412
Alex Nixonb5401a92010-03-18 16:31:34 -04002413config PCI_XEN
2414 def_bool y
2415 depends on PCI && XEN
2416 select SWIOTLB_XEN
2417
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002418config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002419 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002420 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002421
2422config PCI_MMCONFIG
2423 bool "Support mmconfig PCI config space access"
2424 depends on X86_64 && PCI && ACPI
2425
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002426config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002427 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002428 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002429 help
2430 Read the PCI windows out of the CNB20LE host bridge. This allows
2431 PCI hotplug to work on systems with the CNB20LE chipset which do
2432 not have ACPI.
2433
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002434 There's no public spec for this chipset, and this functionality
2435 is known to be incomplete.
2436
2437 You should say N unless you know you need this.
2438
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002439source "drivers/pci/Kconfig"
2440
David Rientjes1c00f012011-03-22 16:34:59 -07002441# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002442config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002443 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2444 default y
2445 help
2446 Enables ISA-style DMA support for devices requiring such controllers.
2447 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002448
2449if X86_32
2450
2451config ISA
2452 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002453 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002454 Find out whether you have ISA slots on your motherboard. ISA is the
2455 name of a bus system, i.e. the way the CPU talks to the other stuff
2456 inside your box. Other bus systems are PCI, EISA, MicroChannel
2457 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2458 newer boards don't support it. If you have ISA, say Y, otherwise N.
2459
2460config EISA
2461 bool "EISA support"
2462 depends on ISA
2463 ---help---
2464 The Extended Industry Standard Architecture (EISA) bus was
2465 developed as an open alternative to the IBM MicroChannel bus.
2466
2467 The EISA bus provided some of the features of the IBM MicroChannel
2468 bus while maintaining backward compatibility with cards made for
2469 the older ISA bus. The EISA bus saw limited use between 1988 and
2470 1995 when it was made obsolete by the PCI bus.
2471
2472 Say Y here if you are building a kernel for an EISA-based machine.
2473
2474 Otherwise, say N.
2475
2476source "drivers/eisa/Kconfig"
2477
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002478config SCx200
2479 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002480 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002481 This provides basic support for National Semiconductor's
2482 (now AMD's) Geode processors. The driver probes for the
2483 PCI-IDs of several on-chip devices, so its a good dependency
2484 for other scx200_* drivers.
2485
2486 If compiled as a module, the driver is named scx200.
2487
2488config SCx200HR_TIMER
2489 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002490 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002491 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002492 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493 This driver provides a clocksource built upon the on-chip
2494 27MHz high-resolution timer. Its also a workaround for
2495 NSC Geode SC-1100's buggy TSC, which loses time when the
2496 processor goes idle (as is done by the scheduler). The
2497 other workaround is idle=poll boot option.
2498
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002499config OLPC
2500 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002501 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002502 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002503 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002504 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002505 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002506 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002507 Add support for detecting the unique features of the OLPC
2508 XO hardware.
2509
Daniel Drakea3128582011-06-25 17:34:10 +01002510config OLPC_XO1_PM
2511 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002512 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002513 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002514 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002515 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002516
Daniel Drakecfee9592011-06-25 17:34:17 +01002517config OLPC_XO1_RTC
2518 bool "OLPC XO-1 Real Time Clock"
2519 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2520 ---help---
2521 Add support for the XO-1 real time clock, which can be used as a
2522 programmable wakeup source.
2523
Daniel Drake7feda8e2011-06-25 17:34:12 +01002524config OLPC_XO1_SCI
2525 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002526 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002527 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002528 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002529 select GPIO_CS5535
2530 select MFD_CORE
2531 ---help---
2532 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002533 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002534 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002535 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002536 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002537 - AC adapter status updates
2538 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002539
Daniel Drakea0f30f52011-06-25 17:34:18 +01002540config OLPC_XO15_SCI
2541 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002542 depends on OLPC && ACPI
2543 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002544 ---help---
2545 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2546 - EC-driven system wakeups
2547 - AC adapter status updates
2548 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002549
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002550config ALIX
2551 bool "PCEngines ALIX System Support (LED setup)"
2552 select GPIOLIB
2553 ---help---
2554 This option enables system support for the PCEngines ALIX.
2555 At present this just sets up LEDs for GPIO control on
2556 ALIX2/3/6 boards. However, other system specific setup should
2557 get added here.
2558
2559 Note: You must still enable the drivers for GPIO and LED support
2560 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2561
2562 Note: You have to set alix.force=1 for boards with Award BIOS.
2563
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002564config NET5501
2565 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2566 select GPIOLIB
2567 ---help---
2568 This option enables system support for the Soekris Engineering net5501.
2569
Philip A. Prindeville31970592012-01-14 01:45:39 -07002570config GEOS
2571 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2572 select GPIOLIB
2573 depends on DMI
2574 ---help---
2575 This option enables system support for the Traverse Technologies GEOS.
2576
Vivien Didelot7d029122013-01-04 16:18:14 -05002577config TS5500
2578 bool "Technologic Systems TS-5500 platform support"
2579 depends on MELAN
2580 select CHECK_SIGNATURE
2581 select NEW_LEDS
2582 select LEDS_CLASS
2583 ---help---
2584 This option enables system support for the Technologic Systems TS-5500.
2585
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002586endif # X86_32
2587
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002588config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002589 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002590 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002591
2592source "drivers/pcmcia/Kconfig"
2593
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002594config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002595 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002596 depends on PCI
2597 default n
2598 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002599 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002600 infrastructure code to support RapidIO interconnect devices.
2601
2602source "drivers/rapidio/Kconfig"
2603
David Herrmanne3263ab2013-08-02 14:05:22 +02002604config X86_SYSFB
2605 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2606 help
2607 Firmwares often provide initial graphics framebuffers so the BIOS,
2608 bootloader or kernel can show basic video-output during boot for
2609 user-guidance and debugging. Historically, x86 used the VESA BIOS
2610 Extensions and EFI-framebuffers for this, which are mostly limited
2611 to x86.
2612 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2613 framebuffers so the new generic system-framebuffer drivers can be
2614 used on x86. If the framebuffer is not compatible with the generic
2615 modes, it is adverticed as fallback platform framebuffer so legacy
2616 drivers like efifb, vesafb and uvesafb can pick it up.
2617 If this option is not selected, all system framebuffers are always
2618 marked as fallback platform framebuffers as usual.
2619
2620 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2621 not be able to pick up generic system framebuffers if this option
2622 is selected. You are highly encouraged to enable simplefb as
2623 replacement if you select this option. simplefb can correctly deal
2624 with generic system framebuffers. But you should still keep vesafb
2625 and others enabled as fallback if a system framebuffer is
2626 incompatible with simplefb.
2627
2628 If unsure, say Y.
2629
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002630endmenu
2631
2632
2633menu "Executable file formats / Emulations"
2634
2635source "fs/Kconfig.binfmt"
2636
2637config IA32_EMULATION
2638 bool "IA32 Emulation"
2639 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002640 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002641 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002642 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002643 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002644 Include code to run legacy 32-bit programs under a
2645 64-bit kernel. You should likely turn this on, unless you're
2646 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002647
2648config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002649 tristate "IA32 a.out support"
2650 depends on IA32_EMULATION
2651 ---help---
2652 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002653
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002654config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002655 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002656 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002657 ---help---
2658 Include code to run binaries for the x32 native 32-bit ABI
2659 for 64-bit processors. An x32 process gets access to the
2660 full 64-bit register file and wide data path while leaving
2661 pointers at 32 bits for smaller memory footprint.
2662
2663 You will need a recent binutils (2.22 or later) with
2664 elf32_x86_64 support enabled to compile a kernel with this
2665 option set.
2666
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002667config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002668 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002669 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002670
Jan Beulich3120e252012-09-10 12:41:45 +01002671if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002672config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002673 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002674
2675config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002676 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002677 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002678
David Howellsee009e4a02011-03-07 15:06:20 +00002679config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002680 def_bool y
2681 depends on KEYS
2682endif
David Howellsee009e4a02011-03-07 15:06:20 +00002683
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002684endmenu
2685
2686
Keith Packarde5beae12008-11-03 18:21:45 +01002687config HAVE_ATOMIC_IOMAP
2688 def_bool y
2689 depends on X86_32
2690
Alessandro Rubini4692d772012-04-04 19:39:58 +02002691config X86_DEV_DMA_OPS
2692 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002693 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002694
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002695config X86_DMA_REMAP
2696 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002697 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002698
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002699config PMC_ATOM
2700 def_bool y
2701 depends on PCI
2702
Keith Busch185a3832016-01-12 13:18:10 -07002703config VMD
2704 depends on PCI_MSI
2705 tristate "Volume Management Device Driver"
2706 default N
2707 ---help---
2708 Adds support for the Intel Volume Management Device (VMD). VMD is a
2709 secondary PCI host bridge that allows PCI Express root ports,
2710 and devices attached to them, to be removed from the default
2711 PCI domain and placed within the VMD domain. This provides
2712 more bus resources than are otherwise possible with a
2713 single domain. If you know your system provides one of these and
2714 has devices attached to it, say Y; if you are not sure, say N.
2715
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002716source "net/Kconfig"
2717
2718source "drivers/Kconfig"
2719
2720source "drivers/firmware/Kconfig"
2721
2722source "fs/Kconfig"
2723
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002724source "arch/x86/Kconfig.debug"
2725
2726source "security/Kconfig"
2727
2728source "crypto/Kconfig"
2729
Avi Kivityedf88412007-12-16 11:02:48 +02002730source "arch/x86/kvm/Kconfig"
2731
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002732source "lib/Kconfig"