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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
Ingo Molnar6471b822015-06-03 10:00:13 +020022 select ARCH_CLOCKSOURCE_DATA
23 select ARCH_DISCARD_MEMBLOCK
Aleksey Makarov91dda512016-06-20 13:56:12 +030024 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Dan Williams21266be2015-11-19 18:19:29 -080025 select ARCH_HAS_DEVMEM_IS_ALLOWED
Ingo Molnar6471b822015-06-03 10:00:13 +020026 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070027 select ARCH_HAS_FAST_MULTIPLIER
Daniel Micay0f513102017-07-12 14:36:10 -070028 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080029 select ARCH_HAS_GCOV_PROFILE_ALL
Yisheng Xie461a7182016-10-07 17:01:46 -070030 select ARCH_HAS_GIGANTIC_PAGE if X86_64
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
Andy Lutomirski3e5daac2017-05-28 10:00:14 -070048 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
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
Ingo Molnar6471b822015-06-03 10:00:13 +020052 select BUILDTIME_EXTABLE_SORT
53 select CLKEVT_I8253
54 select CLKSRC_I8253 if X86_32
55 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
56 select CLOCKSOURCE_WATCHDOG
57 select CLONE_BACKWARDS if X86_32
58 select COMPAT_OLD_SIGACTION if IA32_EMULATION
59 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070060 select EDAC_ATOMIC_SCRUB
61 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020062 select GENERIC_CLOCKEVENTS
63 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
64 select GENERIC_CLOCKEVENTS_MIN_ADJUST
65 select GENERIC_CMOS_UPDATE
66 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner45a98822018-01-07 22:48:01 +010067 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +020068 select GENERIC_EARLY_IOREMAP
69 select GENERIC_FIND_FIRST_BIT
70 select GENERIC_IOMAP
71 select GENERIC_IRQ_PROBE
72 select GENERIC_IRQ_SHOW
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_SMP_IDLE_THREAD
75 select GENERIC_STRNCPY_FROM_USER
76 select GENERIC_STRNLEN_USER
77 select GENERIC_TIME_VSYSCALL
78 select HAVE_ACPI_APEI if ACPI
79 select HAVE_ACPI_APEI_NMI if ACPI
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_AOUT if X86_32
82 select HAVE_ARCH_AUDITSYSCALL
Kees Cook5b710f32016-06-23 15:04:01 -070083 select HAVE_ARCH_HARDENED_USERCOPY
Ingo Molnar6471b822015-06-03 10:00:13 +020084 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
85 select HAVE_ARCH_JUMP_LABEL
86 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
87 select HAVE_ARCH_KGDB
88 select HAVE_ARCH_KMEMCHECK
Daniel Cashman9e08f572016-01-14 15:20:06 -080089 select HAVE_ARCH_MMAP_RND_BITS if MMU
90 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Ingo Molnar6471b822015-06-03 10:00:13 +020091 select HAVE_ARCH_SECCOMP_FILTER
92 select HAVE_ARCH_SOFT_DIRTY if X86_64
93 select HAVE_ARCH_TRACEHOOK
94 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Kees Cook0f60a8e2016-07-12 16:19:48 -070095 select HAVE_ARCH_WITHIN_STACK_FRAMES
Daniel Borkmann60777762016-05-13 19:08:28 +020096 select HAVE_EBPF_JIT if X86_64
Andy Lutomirskie37e43a2016-08-11 02:35:23 -070097 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +020098 select HAVE_CC_STACKPROTECTOR
99 select HAVE_CMPXCHG_DOUBLE
100 select HAVE_CMPXCHG_LOCAL
101 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -0700102 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +0200103 select HAVE_C_RECORDMCOUNT
104 select HAVE_DEBUG_KMEMLEAK
105 select HAVE_DEBUG_STACKOVERFLOW
106 select HAVE_DMA_API_DEBUG
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700107 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400108 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900109 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700110 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700111 select HAVE_EXIT_THREAD
Ingo Molnar6471b822015-06-03 10:00:13 +0200112 select HAVE_FENTRY if X86_64
113 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200114 select HAVE_FUNCTION_GRAPH_TRACER
115 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200116 select HAVE_GCC_PLUGINS
Ingo Molnar6471b822015-06-03 10:00:13 +0200117 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530118 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200119 select HAVE_IDE
120 select HAVE_IOREMAP_PROT
121 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
122 select HAVE_IRQ_TIME_ACCOUNTING
123 select HAVE_KERNEL_BZIP2
124 select HAVE_KERNEL_GZIP
125 select HAVE_KERNEL_LZ4
126 select HAVE_KERNEL_LZMA
127 select HAVE_KERNEL_LZO
128 select HAVE_KERNEL_XZ
129 select HAVE_KPROBES
130 select HAVE_KPROBES_ON_FTRACE
131 select HAVE_KRETPROBES
132 select HAVE_KVM
133 select HAVE_LIVEPATCH if X86_64
134 select HAVE_MEMBLOCK
135 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200136 select HAVE_MIXED_BREAKPOINTS_REGS
Petr Mladek42a0bb32016-05-20 17:00:33 -0700137 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200138 select HAVE_OPROFILE
139 select HAVE_OPTPROBES
140 select HAVE_PCSPKR_PLATFORM
141 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200142 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200143 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200144 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200145 select HAVE_REGS_AND_STACK_ACCESS_API
146 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400147 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200148 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300149 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerf37486c2018-05-29 17:48:27 +0200150 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100151 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200152 select MODULES_USE_ELF_RELA if X86_64
153 select MODULES_USE_ELF_REL if X86_32
154 select OLD_SIGACTION if X86_32
155 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
156 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500157 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200158 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200159 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500160 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200161 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700162 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200163 select USER_STACKTRACE_SUPPORT
164 select VIRT_TO_BUS
165 select X86_DEV_DMA_OPS if X86_64
166 select X86_FEATURE_NAMES if PROC_FS
Josh Poimboeufd4883d52016-02-28 22:22:43 -0600167 select HAVE_STACK_VALIDATION if X86_64
Dave Hansen63c17fb2016-02-12 13:02:08 -0800168 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen66d37572016-02-12 13:02:32 -0800169 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530170
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200171config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100172 def_bool y
173 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200174
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700175config OUTPUT_FORMAT
176 string
177 default "elf32-i386" if X86_32
178 default "elf64-x86-64" if X86_64
179
Sam Ravnborg73531902008-05-25 23:03:18 +0200180config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200181 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200182 default "arch/x86/configs/i386_defconfig" if X86_32
183 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200184
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100185config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100186 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100187
188config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100189 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100190
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100191config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100192 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100193
Daniel Cashman9e08f572016-01-14 15:20:06 -0800194config ARCH_MMAP_RND_BITS_MIN
195 default 28 if 64BIT
196 default 8
197
198config ARCH_MMAP_RND_BITS_MAX
199 default 32 if 64BIT
200 default 16
201
202config ARCH_MMAP_RND_COMPAT_BITS_MIN
203 default 8
204
205config ARCH_MMAP_RND_COMPAT_BITS_MAX
206 default 16
207
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100208config SBUS
209 bool
210
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800211config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100212 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400213 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800214
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700215config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700216 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700217
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100218config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100219 def_bool y
220 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100221
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100222config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100223 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100224 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000225 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
226
227config GENERIC_BUG_RELATIVE_POINTERS
228 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100229
230config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100231 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100232
233config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100234 def_bool y
235 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100236
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100237config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100238 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100239
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100240config GENERIC_CALIBRATE_DELAY
241 def_bool y
242
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800243config ARCH_HAS_CPU_RELAX
244 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100245
Pekka Enberg1b27d052008-04-28 02:12:22 -0700246config ARCH_HAS_CACHE_LINE_SIZE
247 def_bool y
248
Mike Travisdd5af902008-01-30 13:33:32 +0100249config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900250 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100251
Tejun Heo08fc4582009-08-14 15:00:49 +0900252config NEED_PER_CPU_EMBED_FIRST_CHUNK
253 def_bool y
254
255config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900256 def_bool y
257
Johannes Berg801e4062007-12-08 02:12:39 +0100258config ARCH_HIBERNATION_POSSIBLE
259 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100260
Johannes Bergf4cb5702007-12-08 02:14:00 +0100261config ARCH_SUSPEND_POSSIBLE
262 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100263
Steve Cappercfe28c52013-04-29 14:29:48 +0100264config ARCH_WANT_HUGE_PMD_SHARE
265 def_bool y
266
Steve Capper53313b22013-04-30 08:03:42 +0100267config ARCH_WANT_GENERAL_HUGETLB
268 def_bool y
269
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100270config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000271 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100272
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100273config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000274 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100275
Ingo Molnar765c68b2008-04-09 11:03:37 +0200276config ARCH_SUPPORTS_OPTIMIZED_INLINING
277 def_bool y
278
Akinobu Mita6a11f752009-03-31 15:23:17 -0700279config ARCH_SUPPORTS_DEBUG_PAGEALLOC
280 def_bool y
281
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300282config KASAN_SHADOW_OFFSET
283 hex
284 depends on KASAN
285 default 0xdffffc0000000000
286
Shane Wang69575d32009-09-01 18:25:07 -0700287config HAVE_INTEL_TXT
288 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700289 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700290
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100291config X86_32_SMP
292 def_bool y
293 depends on X86_32 && SMP
294
295config X86_64_SMP
296 def_bool y
297 depends on X86_64 && SMP
298
Tejun Heoccbeed32009-02-09 22:17:40 +0900299config X86_32_LAZY_GS
300 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900301 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900302
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530303config ARCH_SUPPORTS_UPROBES
304 def_bool y
305
Rob Herringd20642f2014-04-18 17:19:54 -0500306config FIX_EARLYCON_MEM
307 def_bool y
308
Kees Cook9ccaf772016-02-17 14:41:14 -0800309config DEBUG_RODATA
310 def_bool y
311
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700312config PGTABLE_LEVELS
313 int
314 default 4 if X86_64
315 default 3 if X86_PAE
316 default 2
317
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100318source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700319source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100320
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100321menu "Processor type and features"
322
Randy Dunlap5ee71532012-01-16 11:57:18 -0800323config ZONE_DMA
324 bool "DMA memory allocation support" if EXPERT
325 default y
326 help
327 DMA memory allocation support allows devices with less than 32-bit
328 addressing to allocate within the first 16MB of address space.
329 Disable if no such devices will be used.
330
331 If unsure, say Y.
332
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100333config SMP
334 bool "Symmetric multi-processing support"
335 ---help---
336 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800337 a system with only one CPU, say N. If you have a system with more
338 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100339
Robert Graffham4a474152014-01-23 15:55:29 -0800340 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100341 machines, but will use only one CPU of a multiprocessor machine. If
342 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800343 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100344 will run faster if you say N here.
345
346 Note that if you say Y here and choose architecture "586" or
347 "Pentium" under "Processor family", the kernel will not work on 486
348 architectures. Similarly, multiprocessor kernels for the "PPro"
349 architecture may not work on all Pentium based boards.
350
351 People using multiprocessor machines who say Y here should also say
352 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
353 Management" code will be disabled if you say Y here.
354
Paul Bolle395cf962011-08-15 02:02:26 +0200355 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100356 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
357 <http://www.tldp.org/docs.html#howto>.
358
359 If you don't know what to do here, say N.
360
Josh Triplett9def39be2013-10-30 08:09:45 -0700361config X86_FEATURE_NAMES
362 bool "Processor feature human-readable names" if EMBEDDED
363 default y
364 ---help---
365 This option compiles in a table of x86 feature bits and corresponding
366 names. This is required to support /proc/cpuinfo and a few kernel
367 messages. You can disable this to save space, at the expense of
368 making those few kernel messages show numeric feature bits instead.
369
370 If in doubt, say Y.
371
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100372config X86_FAST_FEATURE_TESTS
373 bool "Fast CPU feature tests" if EMBEDDED
374 default y
375 ---help---
376 Some fast-paths in the kernel depend on the capabilities of the CPU.
377 Say Y here for the kernel to patch in the appropriate code at runtime
378 based on the capabilities of the CPU. The infrastructure for patching
379 code at runtime takes up some additional space; space-constrained
380 embedded systems may wish to say N here to produce smaller, slightly
381 slower code.
382
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800383config X86_X2APIC
384 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200385 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800386 ---help---
387 This enables x2apic support on CPUs that have this feature.
388
389 This allows 32-bit apic IDs (so it can support very large systems),
390 and accesses the local apic via MSRs not via mmio.
391
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800392 If you don't know what to do here, say N.
393
Yinghai Lu6695c852008-06-19 12:13:09 -0700394config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700395 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000396 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200397 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100398 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700399 For old smp systems that do not have proper acpi support. Newer systems
400 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700401
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800402config X86_BIGSMP
403 bool "Support for big SMP systems with more than 8 CPUs"
404 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100405 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800406 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100407
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000408config GOLDFISH
409 def_bool y
410 depends on X86_GOLDFISH
411
David Woodhouse2bb5de42018-01-11 21:46:25 +0000412config RETPOLINE
413 bool "Avoid speculative indirect branches in kernel"
414 default y
415 ---help---
416 Compile kernel with the retpoline compiler options to guard against
417 kernel-to-user data leaks by avoiding speculative indirect
418 branches. Requires a compiler with -mindirect-branch=thunk-extern
419 support for full protection. The kernel may run slower.
420
421 Without compiler support, at least indirect branches in assembler
422 code are eliminated. Since this includes the syscall entry path,
423 it is not entirely pointless.
424
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800425if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800426config X86_EXTENDED_PLATFORM
427 bool "Support for extended (non-PC) x86 platforms"
428 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100429 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100430 If you disable this option then the kernel will only support
431 standard PC platforms. (which covers the vast majority of
432 systems out there.)
433
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800434 If you enable this option then you'll be able to select support
435 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100436 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800437 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800438 RDC R-321x SoC
439 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200440 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200441 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100442
443 If you have one of these systems, or if you want to build a
444 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800445endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100446
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800447if X86_64
448config X86_EXTENDED_PLATFORM
449 bool "Support for extended (non-PC) x86 platforms"
450 default y
451 ---help---
452 If you disable this option then the kernel will only support
453 standard PC platforms. (which covers the vast majority of
454 systems out there.)
455
456 If you enable this option then you'll be able to select support
457 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b2011-12-06 00:07:26 +0800458 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800459 ScaleMP vSMP
460 SGI Ultraviolet
461
462 If you have one of these systems, or if you want to build a
463 generic distribution kernel, say Y here - otherwise say N.
464endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800465# This is an alphabetically sorted list of 64 bit extended platforms
466# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b2011-12-06 00:07:26 +0800467config X86_NUMACHIP
468 bool "Numascale NumaChip"
469 depends on X86_64
470 depends on X86_EXTENDED_PLATFORM
471 depends on NUMA
472 depends on SMP
473 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700474 depends on PCI_MMCONFIG
Steffen Persvold44b111b2011-12-06 00:07:26 +0800475 ---help---
476 Adds support for Numascale NumaChip large-SMP systems. Needed to
477 enable more than ~168 cores.
478 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100479
Ingo Molnar6a485652009-01-27 18:29:13 +0100480config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800481 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100482 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100483 select PARAVIRT
484 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800485 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300486 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100487 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100488 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
489 supposed to run on these EM64T-based machines. Only choose this option
490 if you have one of these machines.
491
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800492config X86_UV
493 bool "SGI Ultraviolet"
494 depends on X86_64
495 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500496 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800497 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700498 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200499 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800500 ---help---
501 This option is needed in order to support SGI Ultraviolet systems.
502 If you don't have one of these, you should say N here.
503
504# Following is an alphabetically sorted list of 32 bit extended platforms
505# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100506
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000507config X86_GOLDFISH
508 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100509 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000510 ---help---
511 Enable support for the Goldfish virtual platform used primarily
512 for Android development. Unless you are building for the Android
513 Goldfish emulator say N here.
514
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800515config X86_INTEL_CE
516 bool "CE4100 TV platform"
517 depends on PCI
518 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800519 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800520 depends on X86_32
521 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800522 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100523 select OF
524 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800525 ---help---
526 Select for the Intel CE media processor (CE4100) SOC.
527 This option compiles in support for the CE4100 SOC for settop
528 boxes and media devices.
529
David Cohen4cb9b002013-12-16 17:37:26 -0800530config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100531 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100532 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800533 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000534 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200535 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000536 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000537 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800538 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000539 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000540 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000541 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000542 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000543 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800544 Select to build a kernel capable of supporting Intel MID (Mobile
545 Internet Device) platform systems which do not have the PCI legacy
546 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000547
David Cohen4cb9b002013-12-16 17:37:26 -0800548 Intel MID platforms are based on an Intel processor and chipset which
549 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100550
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000551config X86_INTEL_QUARK
552 bool "Intel Quark platform support"
553 depends on X86_32
554 depends on X86_EXTENDED_PLATFORM
555 depends on X86_PLATFORM_DEVICES
556 depends on X86_TSC
557 depends on PCI
558 depends on PCI_GOANY
559 depends on X86_IO_APIC
560 select IOSF_MBI
561 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200562 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000563 ---help---
564 Select to include support for Quark X1000 SoC.
565 Say Y here if you have a Quark based system such as the Arduino
566 compatible Intel Galileo.
567
Vadim Pasternak58cbbee2016-09-22 21:13:42 +0000568config MLX_PLATFORM
569 tristate "Mellanox Technologies platform support"
570 depends on X86_64
571 depends on X86_EXTENDED_PLATFORM
572 ---help---
573 This option enables system support for the Mellanox Technologies
574 platform.
575
576 Say Y here if you are building a kernel for Mellanox system.
577
578 Otherwise, say N.
579
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000580config X86_INTEL_LPSS
581 bool "Intel Low Power Subsystem Support"
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100582 depends on X86 && ACPI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000583 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300584 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100585 select IOSF_MBI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000586 ---help---
587 Select to build support for Intel Low Power Subsystem such as
588 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300589 things like clock tree (common clock framework) and pincontrol
590 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000591
Ken Xue92082a82015-02-06 08:27:51 +0800592config X86_AMD_PLATFORM_DEVICE
593 bool "AMD ACPI2Platform devices support"
594 depends on ACPI
595 select COMMON_CLK
596 select PINCTRL
597 ---help---
598 Select to interpret AMD specific ACPI device to platform device
599 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
600 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
601 implemented under PINCTRL subsystem.
602
David E. Boxced3ce72014-09-17 22:13:50 -0700603config IOSF_MBI
604 tristate "Intel SoC IOSF Sideband support for SoC platforms"
605 depends on PCI
606 ---help---
607 This option enables sideband register access support for Intel SoC
608 platforms. On these platforms the IOSF sideband is used in lieu of
609 MSR's for some register accesses, mostly but not limited to thermal
610 and power. Drivers may query the availability of this device to
611 determine if they need the sideband in order to work on these
612 platforms. The sideband is available on the following SoC products.
613 This list is not meant to be exclusive.
614 - BayTrail
615 - Braswell
616 - Quark
617
618 You should say Y if you are running a kernel on one of these SoC's.
619
David E. Boxed2226b2014-09-17 22:13:51 -0700620config IOSF_MBI_DEBUG
621 bool "Enable IOSF sideband access through debugfs"
622 depends on IOSF_MBI && DEBUG_FS
623 ---help---
624 Select this option to expose the IOSF sideband access registers (MCR,
625 MDR, MCRX) through debugfs to write and read register information from
626 different units on the SoC. This is most useful for obtaining device
627 state information for debug and analysis. As this is a general access
628 mechanism, users of this option would have specific knowledge of the
629 device they want to access.
630
631 If you don't require the option or are in doubt, say N.
632
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800633config X86_RDC321X
634 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100635 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800636 depends on X86_EXTENDED_PLATFORM
637 select M486
638 select X86_REBOOTFIXUPS
639 ---help---
640 This option is needed for RDC R-321x system-on-chip, also known
641 as R-8610-(G).
642 If you don't have one of these chips, you should say N here.
643
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100644config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100645 bool "Support non-standard 32-bit SMP architectures"
646 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800647 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100648 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800649 This option compiles in the bigsmp and STA2X11 default
650 subarchitectures. It is intended for a generic binary
651 kernel. If you select them all, kernel will probe it one by
652 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700653
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800654# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700655
Linus Torvaldsd949f362009-09-26 09:35:07 -0700656config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100657 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700658 # MCE code calls memory_failure():
659 depends on X86_MCE
660 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700661 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
662 depends on X86_64 || !SPARSEMEM
663 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700664
Alessandro Rubini83125a32012-04-04 19:40:21 +0200665config STA2X11
666 bool "STA2X11 Companion Chip Support"
667 depends on X86_32_NON_STANDARD && PCI
668 select X86_DEV_DMA_OPS
669 select X86_DMA_REMAP
670 select SWIOTLB
671 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200672 select GPIOLIB
Alessandro Rubini83125a32012-04-04 19:40:21 +0200673 default n
674 ---help---
675 This adds support for boards based on the STA2X11 IO-Hub,
676 a.k.a. "ConneXt". The chip is used in place of the standard
677 PC chipset, so all "standard" peripherals are missing. If this
678 option is selected the kernel will still be able to boot on
679 standard PC machines.
680
Shérab82148d12010-09-25 06:06:57 +0200681config X86_32_IRIS
682 tristate "Eurobraille/Iris poweroff module"
683 depends on X86_32
684 ---help---
685 The Iris machines from EuroBraille do not have APM or ACPI support
686 to shut themselves down properly. A special I/O sequence is
687 needed to do so, which is what this module does at
688 kernel shutdown.
689
690 This is only for Iris machines from EuroBraille.
691
692 If unused, say N.
693
Ingo Molnarae1e9132008-11-11 09:05:16 +0100694config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100695 def_bool y
696 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800697 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100698 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100699 Calculate simpler /proc/<PID>/wchan values. If this option
700 is disabled then wchan values will recurse back to the
701 caller function. This provides more accurate wchan values,
702 at the expense of slightly more scheduling overhead.
703
704 If in doubt, say "Y".
705
Borislav Petkov6276a072013-03-04 21:20:21 +0100706menuconfig HYPERVISOR_GUEST
707 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100708 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100709 Say Y here to enable options for running Linux under various hyper-
710 visors. This option enables basic hypervisor detection and platform
711 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100712
Borislav Petkov6276a072013-03-04 21:20:21 +0100713 If you say N, all options in this submenu will be skipped and
714 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100715
Borislav Petkov6276a072013-03-04 21:20:21 +0100716if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100717
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100718config PARAVIRT
719 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100720 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100721 This changes the kernel so it can modify itself when it is run
722 under a hypervisor, potentially improving performance significantly
723 over full virtualization. However, when run without a hypervisor
724 the kernel is theoretically slower and slightly larger.
725
Borislav Petkov6276a072013-03-04 21:20:21 +0100726config PARAVIRT_DEBUG
727 bool "paravirt-ops debugging"
728 depends on PARAVIRT && DEBUG_KERNEL
729 ---help---
730 Enable to debug paravirt_ops internals. Specifically, BUG if
731 a paravirt_op is missing when it is called.
732
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700733config PARAVIRT_SPINLOCKS
734 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700735 depends on PARAVIRT && SMP
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700736 ---help---
737 Paravirtualized spinlocks allow a pvops backend to replace the
738 spinlock implementation with something virtualization-friendly
739 (for example, block the virtual CPU rather than spinning).
740
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530741 It has a minimal impact on native kernels and gives a nice performance
742 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700743
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530744 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700745
Waiman Long45e898b2015-11-09 19:09:25 -0500746config QUEUED_LOCK_STAT
747 bool "Paravirt queued spinlock statistics"
Peter Zijlstracfd89832016-05-18 20:43:02 +0200748 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
Waiman Long45e898b2015-11-09 19:09:25 -0500749 ---help---
750 Enable the collection of statistical data on the slowpath
751 behavior of paravirtualized queued spinlocks and report
752 them on debugfs.
753
Borislav Petkov6276a072013-03-04 21:20:21 +0100754source "arch/x86/xen/Kconfig"
755
756config KVM_GUEST
757 bool "KVM Guest support (including kvmclock)"
758 depends on PARAVIRT
759 select PARAVIRT_CLOCK
760 default y
761 ---help---
762 This option enables various optimizations for running under the KVM
763 hypervisor. It includes a paravirtualized clock, so that instead
764 of relying on a PIT (or probably other) emulation by the
765 underlying device model, the host provides the guest with
766 timing infrastructure such as time of day, and system time
767
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530768config KVM_DEBUG_FS
769 bool "Enable debug information for KVM Guests in debugfs"
770 depends on KVM_GUEST && DEBUG_FS
771 default n
772 ---help---
773 This option enables collection of various statistics for KVM guest.
774 Statistics are displayed in debugfs filesystem. Enabling this option
775 may incur significant overhead.
776
Borislav Petkov6276a072013-03-04 21:20:21 +0100777source "arch/x86/lguest/Kconfig"
778
779config PARAVIRT_TIME_ACCOUNTING
780 bool "Paravirtual steal time accounting"
781 depends on PARAVIRT
782 default n
783 ---help---
784 Select this option to enable fine granularity task steal time
785 accounting. Time spent executing other tasks in parallel with
786 the current vCPU is discounted from the vCPU power. To account for
787 that, there can be a small performance impact.
788
789 If in doubt, say N here.
790
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200791config PARAVIRT_CLOCK
792 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200793
Borislav Petkov6276a072013-03-04 21:20:21 +0100794endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400795
Yinghai Lu08677212010-02-10 01:20:20 -0800796config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700797 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800798
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100799source "arch/x86/Kconfig.cpu"
800
801config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100802 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100803 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100804 ---help---
805 Use the IA-PC HPET (High Precision Event Timer) to manage
806 time in preference to the PIT and RTC, if a HPET is
807 present.
808 HPET is the next generation timer replacing legacy 8254s.
809 The HPET provides a stable time base on SMP
810 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200811 as it is off-chip. The interface used is documented
812 in the HPET spec, revision 1.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100813
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100814 You can safely choose Y here. However, HPET will only be
815 activated if the platform and the BIOS support this feature.
816 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100817
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100818 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100819
820config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100821 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800822 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100823
Jacob Panbb24c472009-09-02 07:37:17 -0700824config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000825 def_bool y if X86_INTEL_MID
826 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100827 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000828 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700829 help
830 APB timer is the replacement for 8254, HPET on X86 MID platforms.
831 The APBT provides a stable time base on SMP
832 systems, unlike the TSC, but it is more expensive to access,
833 as it is off-chip. APB timers are always running regardless of CPU
834 C states, they are used as per CPU clockevent device when possible.
835
David Rientjes6a108a12011-01-20 14:44:16 -0800836# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100837# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700838config DMI
839 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800840 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800841 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100842 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700843 Enabled scanning of DMI to identify machine quirks. Say Y
844 here unless you have verified that your setup is not
845 affected by entries in the DMI blacklist. Required by PNP
846 BIOS code.
847
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100848config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700849 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100850 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200851 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100852 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200853 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
854 GART based hardware IOMMUs.
855
856 The GART supports full DMA access for devices with 32-bit access
857 limitations, on systems with more than 3 GB. This is usually needed
858 for USB, sound, many IDE/SATA chipsets and some other devices.
859
860 Newer systems typically have a modern AMD IOMMU, supported via
861 the CONFIG_AMD_IOMMU=y config option.
862
863 In normal configurations this driver is only active when needed:
864 there's more than 3 GB of memory and the system contains a
865 32-bit limited device.
866
867 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100868
869config CALGARY_IOMMU
870 bool "IBM Calgary IOMMU support"
871 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700872 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100873 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100874 Support for hardware IOMMUs in IBM's xSeries x366 and x460
875 systems. Needed to run systems with more than 3GB of memory
876 properly with 32-bit PCI devices that do not support DAC
877 (Double Address Cycle). Calgary also supports bus level
878 isolation, where all DMAs pass through the IOMMU. This
879 prevents them from going anywhere except their intended
880 destination. This catches hard-to-find kernel bugs and
881 mis-behaving drivers and devices that do not use the DMA-API
882 properly to set up their DMA buffers. The IOMMU can be
883 turned off at boot time with the iommu=off parameter.
884 Normally the kernel will make the right choice by itself.
885 If unsure, say Y.
886
887config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100888 def_bool y
889 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100890 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100891 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100892 Should Calgary be enabled by default? if you choose 'y', Calgary
893 will be used (if it exists). If you choose 'n', Calgary will not be
894 used even if it exists. If you choose 'n' and would like to use
895 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
896 If unsure, say Y.
897
898# need this always selected by IOMMU for the VIA workaround
899config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100900 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100901 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100902 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700903 which don't have a hardware IOMMU. Using this PCI devices
904 which can only access 32-bits of memory can be used on systems
905 with more than 3 GB of memory.
906 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100907
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700908config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100909 def_bool y
910 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700911
Mike Travis1184dc22008-05-12 21:21:12 +0200912config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200913 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700914 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800915 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100916 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200917 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200918 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100919
920config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800921 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400922 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500923 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500924 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800925 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500926 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800927 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300928 default "8" if SMP && X86_32
929 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100930 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100931 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500932 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300933 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100934 minimum value which makes sense is 2.
935
936 This is purely to save memory - each supported CPU adds
937 approximately eight kilobytes to the kernel image.
938
939config SCHED_SMT
Thomas Gleixner4cc15492018-11-25 19:33:37 +0100940 def_bool y if SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100941
942config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100943 def_bool y
944 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200945 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100946 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100947 Multi-core scheduler support improves the CPU scheduler's decision
948 making when dealing with multi-core CPU chips at a cost of slightly
949 increased overhead in some places. If unsure say N here.
950
951source "kernel/Kconfig.preempt"
952
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000953config UP_LATE_INIT
954 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100955 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000956
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100957config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000958 bool "Local APIC support on uniprocessors" if !PCI_MSI
959 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000960 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100961 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100962 A local APIC (Advanced Programmable Interrupt Controller) is an
963 integrated interrupt controller in the CPU. If you have a single-CPU
964 system which has a processor with a local APIC, you can say Y here to
965 enable and use it. If you say Y here even though your machine doesn't
966 have a local APIC, then the kernel will still run with no slowdown at
967 all. The local APIC supports CPU-generated self-interrupts (timer,
968 performance counters), and the NMI watchdog which detects hard
969 lockups.
970
971config X86_UP_IOAPIC
972 bool "IO-APIC support on uniprocessors"
973 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100974 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100975 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
976 SMP-capable replacement for PC-style interrupt controllers. Most
977 SMP systems and many recent uniprocessor systems have one.
978
979 If you have a single-CPU system with an IO-APIC, you can say Y here
980 to use it. If you say Y here even though your machine doesn't have
981 an IO-APIC, then the kernel will still run with no slowdown at all.
982
983config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100984 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200985 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800986 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800987 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100988
989config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000990 def_bool y
991 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100992
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200993config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
994 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200995 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100996 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200997 This option enables a workaround that fixes a source of
998 spurious interrupts. This is recommended when threaded
999 interrupt handling is used on systems where the generation of
1000 superfluous "boot interrupts" cannot be disabled.
1001
1002 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1003 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1004 kernel does during interrupt handling). On chipsets where this
1005 boot IRQ generation cannot be disabled, this workaround keeps
1006 the original IRQ line masked so that only the equivalent "boot
1007 IRQ" is delivered to the CPUs. The workaround also tells the
1008 kernel to set up the IRQ handler on the boot IRQ line. In this
1009 way only one interrupt is delivered to the kernel. Otherwise
1010 the spurious second interrupt may cause the kernel to bring
1011 down (vital) interrupt lines.
1012
1013 Only affects "broken" chipsets. Interrupt sharing may be
1014 increased on these systems.
1015
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001016config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001017 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001018 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001019 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001020 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +02001021 Machine Check support allows the processor to notify the
1022 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001023 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001024 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001025
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001026config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001027 def_bool y
1028 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001029 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001030 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001031 Additional support for intel specific MCE features such as
1032 the thermal monitor.
1033
1034config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001035 def_bool y
1036 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001037 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001038 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001039 Additional support for AMD specific MCE features such as
1040 the DRAM Error Threshold.
1041
Andi Kleen4efc0672009-04-28 19:07:31 +02001042config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001043 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001044 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001045 ---help---
1046 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001047 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001048 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001049
Andi Kleenb2762682009-02-12 13:49:31 +01001050config X86_MCE_THRESHOLD
1051 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001052 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001053
Andi Kleenea149b32009-04-29 19:31:00 +02001054config X86_MCE_INJECT
Borislav Petkov10170a92017-01-23 19:35:06 +01001055 depends on X86_MCE && X86_LOCAL_APIC
Andi Kleenea149b32009-04-29 19:31:00 +02001056 tristate "Machine check injector support"
1057 ---help---
1058 Provide support for injecting machine checks for testing purposes.
1059 If you don't know what a machine check is and you don't do kernel
1060 QA it is safe to say n.
1061
Andi Kleen4efc0672009-04-28 19:07:31 +02001062config X86_THERMAL_VECTOR
1063 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001064 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001065
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001066source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001067
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001068config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001069 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001070 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001071 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001072 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001073 This option allows user programs to put the CPU into V8086
1074 mode, which is an 80286-era approximation of 16-bit real mode.
1075
1076 Some very old versions of X and/or vbetool require this option
1077 for user mode setting. Similarly, DOSEMU will use it if
1078 available to accelerate real mode DOS programs. However, any
1079 recent version of DOSEMU, X, or vbetool should be fully
1080 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001081 fall back to software emulation. Nevertheless, if you are using
1082 a 16-bit DOS program where 16-bit performance matters, vm86
1083 mode might be faster than emulation and you might want to
1084 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001085
Ingo Molnar1e642812015-09-05 08:58:10 +02001086 Note that any app that works on a 64-bit kernel is unlikely to
1087 need this option, as 64-bit kernels don't, and can't, support
1088 V8086 mode. This option is also unrelated to 16-bit protected
1089 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001090
Ingo Molnar1e642812015-09-05 08:58:10 +02001091 Enabling this option increases the complexity of the kernel
1092 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001093
Ingo Molnar1e642812015-09-05 08:58:10 +02001094 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001095
1096config VM86
1097 bool
1098 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001099
1100config X86_16BIT
1101 bool "Enable support for 16-bit segments" if EXPERT
1102 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001103 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001104 ---help---
1105 This option is required by programs like Wine to run 16-bit
1106 protected mode legacy code on x86 processors. Disabling
1107 this option saves about 300 bytes on i386, or around 6K text
1108 plus 16K runtime memory on x86-64,
1109
1110config X86_ESPFIX32
1111 def_bool y
1112 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001113
H. Peter Anvin197725d2014-05-04 10:00:49 -07001114config X86_ESPFIX64
1115 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001116 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001117
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001118config X86_VSYSCALL_EMULATION
1119 bool "Enable vsyscall emulation" if EXPERT
1120 default y
1121 depends on X86_64
1122 ---help---
1123 This enables emulation of the legacy vsyscall page. Disabling
1124 it is roughly equivalent to booting with vsyscall=none, except
1125 that it will also disable the helpful warning if a program
1126 tries to use a vsyscall. With this option set to N, offending
1127 programs will just segfault, citing addresses of the form
1128 0xffffffffff600?00.
1129
1130 This option is required by many programs built before 2013, and
1131 care should be used even with newer programs if set to N.
1132
1133 Disabling this option saves about 7K of kernel size and
1134 possibly 4K of additional runtime pagetable memory.
1135
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001136config TOSHIBA
1137 tristate "Toshiba Laptop support"
1138 depends on X86_32
1139 ---help---
1140 This adds a driver to safely access the System Management Mode of
1141 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1142 not work on models with a Phoenix BIOS. The System Management Mode
1143 is used to set the BIOS and power saving options on Toshiba portables.
1144
1145 For information on utilities to make use of this driver see the
1146 Toshiba Linux utilities web site at:
1147 <http://www.buzzard.org.uk/toshiba/>.
1148
1149 Say Y if you intend to run this kernel on a Toshiba portable.
1150 Say N otherwise.
1151
1152config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001153 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001154 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001155 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001156 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001157 This option enables legacy /proc/i8k userspace interface in hwmon
1158 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1159 temperature and allows controlling fan speeds of Dell laptops via
1160 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1161 it reports also power and hotkey status. For fan speed control is
1162 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001163
Pali Rohár039ae582015-05-14 13:16:37 +02001164 Say Y if you intend to run this kernel on old Dell laptops or want to
1165 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001166 Say N otherwise.
1167
1168config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001169 bool "Enable X86 board specific fixups for reboot"
1170 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001171 ---help---
1172 This enables chipset and/or board specific fixups to be done
1173 in order to get reboot to work correctly. This is only needed on
1174 some combinations of hardware and BIOS. The symptom, for which
1175 this config is intended, is when reboot ends with a stalled/hung
1176 system.
1177
1178 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001179 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001180
1181 Say Y if you want to enable the fixup. Currently, it's safe to
1182 enable this option even if you don't need it.
1183 Say N otherwise.
1184
1185config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001186 bool "CPU microcode loading support"
1187 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001188 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001189 select FW_LOADER
1190 ---help---
1191 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001192 Intel and AMD processors. The Intel support is for the IA32 family,
1193 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1194 AMD support is for families 0x10 and later. You will obviously need
1195 the actual microcode binary data itself which is not shipped with
1196 the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001197
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001198 The preferred method to load microcode from a detached initrd is described
1199 in Documentation/x86/early-microcode.txt. For that you need to enable
1200 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1201 initrd for microcode blobs.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001202
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001203 In addition, you can build-in the microcode into the kernel. For that you
1204 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1205 to the CONFIG_EXTRA_FIRMWARE config option.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001206
Peter Oruba8d86f392008-07-28 18:44:21 +02001207config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001208 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001209 depends on MICROCODE
1210 default MICROCODE
1211 select FW_LOADER
1212 ---help---
1213 This options enables microcode patch loading support for Intel
1214 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001215
Alanb8989db2014-01-20 18:01:56 +00001216 For the current Intel microcode data package go to
1217 <https://downloadcenter.intel.com> and search for
1218 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001219
Peter Oruba80cc9f12008-07-28 18:44:22 +02001220config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001221 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001222 depends on MICROCODE
1223 select FW_LOADER
1224 ---help---
1225 If you select this option, microcode patch loading support for AMD
1226 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001227
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001228config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001229 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001230 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001231
1232config X86_MSR
1233 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001234 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001235 This device gives privileged processes access to the x86
1236 Model-Specific Registers (MSRs). It is a character device with
1237 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1238 MSR accesses are directed to a specific CPU on multi-processor
1239 systems.
1240
1241config X86_CPUID
1242 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001243 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001244 This device gives processes access to the x86 CPUID instruction to
1245 be executed on a specific processor. It is a character device
1246 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1247 /dev/cpu/31/cpuid.
1248
1249choice
1250 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001251 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001252 depends on X86_32
1253
1254config NOHIGHMEM
1255 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001256 ---help---
1257 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1258 However, the address space of 32-bit x86 processors is only 4
1259 Gigabytes large. That means that, if you have a large amount of
1260 physical memory, not all of it can be "permanently mapped" by the
1261 kernel. The physical memory that's not permanently mapped is called
1262 "high memory".
1263
1264 If you are compiling a kernel which will never run on a machine with
1265 more than 1 Gigabyte total physical RAM, answer "off" here (default
1266 choice and suitable for most users). This will result in a "3GB/1GB"
1267 split: 3GB are mapped so that each process sees a 3GB virtual memory
1268 space and the remaining part of the 4GB virtual memory space is used
1269 by the kernel to permanently map as much physical memory as
1270 possible.
1271
1272 If the machine has between 1 and 4 Gigabytes physical RAM, then
1273 answer "4GB" here.
1274
1275 If more than 4 Gigabytes is used then answer "64GB" here. This
1276 selection turns Intel PAE (Physical Address Extension) mode on.
1277 PAE implements 3-level paging on IA32 processors. PAE is fully
1278 supported by Linux, PAE mode is implemented on all recent Intel
1279 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1280 then the kernel will not boot on CPUs that don't support PAE!
1281
1282 The actual amount of total physical memory will either be
1283 auto detected or can be forced by using a kernel command line option
1284 such as "mem=256M". (Try "man bootparam" or see the documentation of
1285 your boot loader (lilo or loadlin) about how to pass options to the
1286 kernel at boot time.)
1287
1288 If unsure, say "off".
1289
1290config HIGHMEM4G
1291 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001292 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001293 Select this if you have a 32-bit processor and between 1 and 4
1294 gigabytes of physical RAM.
1295
1296config HIGHMEM64G
1297 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001298 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001299 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001300 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001301 Select this if you have a 32-bit processor and more than 4
1302 gigabytes of physical RAM.
1303
1304endchoice
1305
1306choice
David Rientjes6a108a12011-01-20 14:44:16 -08001307 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001308 default VMSPLIT_3G
1309 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001310 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001311 Select the desired split between kernel and user memory.
1312
1313 If the address range available to the kernel is less than the
1314 physical memory installed, the remaining memory will be available
1315 as "high memory". Accessing high memory is a little more costly
1316 than low memory, as it needs to be mapped into the kernel first.
1317 Note that increasing the kernel address space limits the range
1318 available to user programs, making the address space there
1319 tighter. Selecting anything other than the default 3G/1G split
1320 will also likely make your kernel incompatible with binary-only
1321 kernel modules.
1322
1323 If you are not absolutely sure what you are doing, leave this
1324 option alone!
1325
1326 config VMSPLIT_3G
1327 bool "3G/1G user/kernel split"
1328 config VMSPLIT_3G_OPT
1329 depends on !X86_PAE
1330 bool "3G/1G user/kernel split (for full 1G low memory)"
1331 config VMSPLIT_2G
1332 bool "2G/2G user/kernel split"
1333 config VMSPLIT_2G_OPT
1334 depends on !X86_PAE
1335 bool "2G/2G user/kernel split (for full 2G low memory)"
1336 config VMSPLIT_1G
1337 bool "1G/3G user/kernel split"
1338endchoice
1339
1340config PAGE_OFFSET
1341 hex
1342 default 0xB0000000 if VMSPLIT_3G_OPT
1343 default 0x80000000 if VMSPLIT_2G
1344 default 0x78000000 if VMSPLIT_2G_OPT
1345 default 0x40000000 if VMSPLIT_1G
1346 default 0xC0000000
1347 depends on X86_32
1348
1349config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001350 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001351 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001352
1353config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001354 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001355 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001356 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001357 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001358 PAE is required for NX support, and furthermore enables
1359 larger swapspace support for non-overcommit purposes. It
1360 has the cost of more pagetable lookup overhead, and also
1361 consumes more pagetable space per process.
1362
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001363config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001364 def_bool y
1365 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001366
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001367config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001368 def_bool y
1369 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001370
Ingo Molnar10971ab2015-03-05 08:18:23 +01001371config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001372 def_bool y
1373 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001374 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001375 Certain kernel features effectively disable kernel
1376 linear 1 GB mappings (even if the CPU otherwise
1377 supports them), so don't confuse the user by printing
1378 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001379
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001380# Common NUMA Features
1381config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001382 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001383 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001384 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1385 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001386 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001387 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001388
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001389 The kernel will try to allocate memory used by a CPU on the
1390 local memory controller of the CPU and add some more
1391 NUMA awareness to the kernel.
1392
Ingo Molnarc280ea52008-11-08 13:29:45 +01001393 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001394 (or later), AMD Opteron, or EM64T NUMA.
1395
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001396 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001397 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001398
1399 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001400
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001401config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001402 def_bool y
1403 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001404 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001405 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001406 Enable AMD NUMA node topology detection. You should say Y here if
1407 you have a multi processor AMD system. This uses an old method to
1408 read the NUMA configuration directly from the builtin Northbridge
1409 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1410 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001411
1412config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001413 def_bool y
1414 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001415 depends on X86_64 && NUMA && ACPI && PCI
1416 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001417 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001418 Enable ACPI SRAT based node topology detection.
1419
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001420# Some NUMA nodes have memory ranges that span
1421# other nodes. Even though a pfn is valid and
1422# between a node's start and end pfns, it may not
1423# reside on that node. See memmap_init_zone()
1424# for details.
1425config NODES_SPAN_OTHER_NODES
1426 def_bool y
1427 depends on X86_64_ACPI_NUMA
1428
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001429config NUMA_EMU
1430 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001431 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001432 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001433 Enable NUMA emulation. A flat machine will be split
1434 into virtual nodes when booted with "numa=fake=N", where N is the
1435 number of nodes. This is only useful for debugging.
1436
1437config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001438 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001439 range 1 10
1440 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001441 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001442 default "3"
1443 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001444 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001445 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001446 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001447
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001448config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001449 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001450 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001451
1452config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001453 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001454 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001455
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001456config ARCH_FLATMEM_ENABLE
1457 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001458 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001459
1460config ARCH_DISCONTIGMEM_ENABLE
1461 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001462 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001463
1464config ARCH_DISCONTIGMEM_DEFAULT
1465 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001466 depends on NUMA && X86_32
1467
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001468config ARCH_SPARSEMEM_ENABLE
1469 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001470 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001471 select SPARSEMEM_STATIC if X86_32
1472 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1473
Tejun Heo3b166512011-04-01 11:15:12 +02001474config ARCH_SPARSEMEM_DEFAULT
1475 def_bool y
1476 depends on X86_64
1477
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001478config ARCH_SELECT_MEMORY_MODEL
1479 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001480 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001481
1482config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001483 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001484 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001485 help
1486 This option enables a sysfs memory/probe interface for testing.
1487 See Documentation/memory-hotplug.txt for more information.
1488 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001489
Tejun Heo3b166512011-04-01 11:15:12 +02001490config ARCH_PROC_KCORE_TEXT
1491 def_bool y
1492 depends on X86_64 && PROC_KCORE
1493
Avi Kivitya29815a2010-01-10 16:28:09 +02001494config ILLEGAL_POINTER_VALUE
1495 hex
1496 default 0 if X86_32
1497 default 0xdead000000000000 if X86_64
1498
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001499source "mm/Kconfig"
1500
Dan Williams7a678322015-08-19 00:34:34 -04001501config X86_PMEM_LEGACY_DEVICE
1502 bool
1503
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001504config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001505 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001506 depends on PHYS_ADDR_T_64BIT
1507 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001508 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001509 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001510 help
1511 Treat memory marked using the non-standard e820 type of 12 as used
1512 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1513 The kernel will offer these regions to the 'pmem' driver so
1514 they can be used for persistent storage.
1515
1516 Say Y if unsure.
1517
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001518config HIGHPTE
1519 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001520 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001521 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001522 The VM uses one page table entry for each page of physical memory.
1523 For systems with a lot of RAM, this can be wasteful of precious
1524 low memory. Setting this option will put user-space page table
1525 entries in high memory.
1526
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001527config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001528 bool "Check for low memory corruption"
1529 ---help---
1530 Periodically check for memory corruption in low memory, which
1531 is suspected to be caused by BIOS. Even when enabled in the
1532 configuration, it is disabled at runtime. Enable it by
1533 setting "memory_corruption_check=1" on the kernel command
1534 line. By default it scans the low 64k of memory every 60
1535 seconds; see the memory_corruption_check_size and
1536 memory_corruption_check_period parameters in
1537 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001538
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001539 When enabled with the default parameters, this option has
1540 almost no overhead, as it reserves a relatively small amount
1541 of memory and scans it infrequently. It both detects corruption
1542 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001543
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001544 It is, however, intended as a diagnostic tool; if repeatable
1545 BIOS-originated corruption always affects the same memory,
1546 you can use memmap= to prevent the kernel from using that
1547 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001548
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001549config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001550 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001551 depends on X86_CHECK_BIOS_CORRUPTION
1552 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001553 ---help---
1554 Set whether the default state of memory_corruption_check is
1555 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001556
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001557config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001558 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1559 default 64
1560 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001561 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001562 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001563
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001564 The first page contains BIOS data structures that the kernel
1565 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001566
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001567 By default we reserve the first 64K of physical RAM, as a
1568 number of BIOSes are known to corrupt that memory range
1569 during events such as suspend/resume or monitor cable
1570 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001571
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001572 You can set this to 4 if you are absolutely sure that you
1573 trust the BIOS to get all its memory reservations and usages
1574 right. If you know your BIOS have problems beyond the
1575 default 64K area, you can set this to 640 to avoid using the
1576 entire low memory range.
1577
1578 If you have doubts about the BIOS (e.g. suspend/resume does
1579 not work or there's kernel crashes after certain hardware
1580 hotplug events) then you might want to enable
1581 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1582 typical corruption patterns.
1583
1584 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001585
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001586config MATH_EMULATION
1587 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001588 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001589 prompt "Math emulation" if X86_32
1590 ---help---
1591 Linux can emulate a math coprocessor (used for floating point
1592 operations) if you don't have one. 486DX and Pentium processors have
1593 a math coprocessor built in, 486SX and 386 do not, unless you added
1594 a 487DX or 387, respectively. (The messages during boot time can
1595 give you some hints here ["man dmesg"].) Everyone needs either a
1596 coprocessor or this emulation.
1597
1598 If you don't have a math coprocessor, you need to say Y here; if you
1599 say Y here even though you have a coprocessor, the coprocessor will
1600 be used nevertheless. (This behavior can be changed with the kernel
1601 command line option "no387", which comes handy if your coprocessor
1602 is broken. Try "man bootparam" or see the documentation of your boot
1603 loader (lilo or loadlin) about how to pass options to the kernel at
1604 boot time.) This means that it is a good idea to say Y here if you
1605 intend to use this kernel on different machines.
1606
1607 More information about the internals of the Linux math coprocessor
1608 emulation can be found in <file:arch/x86/math-emu/README>.
1609
1610 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1611 kernel, it won't hurt.
1612
1613config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001614 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001615 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001616 ---help---
1617 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1618 the Memory Type Range Registers (MTRRs) may be used to control
1619 processor access to memory ranges. This is most useful if you have
1620 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1621 allows bus write transfers to be combined into a larger transfer
1622 before bursting over the PCI/AGP bus. This can increase performance
1623 of image write operations 2.5 times or more. Saying Y here creates a
1624 /proc/mtrr file which may be used to manipulate your processor's
1625 MTRRs. Typically the X server should use this.
1626
1627 This code has a reasonably generic interface so that similar
1628 control registers on other processors can be easily supported
1629 as well:
1630
1631 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1632 Registers (ARRs) which provide a similar functionality to MTRRs. For
1633 these, the ARRs are used to emulate the MTRRs.
1634 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1635 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1636 write-combining. All of these processors are supported by this code
1637 and it makes sense to say Y here if you have one of them.
1638
1639 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1640 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1641 can lead to all sorts of problems, so it's good to say Y here.
1642
1643 You can safely say Y even if your machine doesn't have MTRRs, you'll
1644 just add about 9 KB to your kernel.
1645
Randy Dunlap7225e752008-07-26 17:54:22 -07001646 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001647
Yinghai Lu95ffa242008-04-29 03:52:33 -07001648config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001649 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001650 prompt "MTRR cleanup support"
1651 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001652 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001653 Convert MTRR layout from continuous to discrete, so X drivers can
1654 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001655
Thomas Gleixneraba37282008-07-15 14:48:48 +02001656 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001657 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001658 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001659
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001660 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001661
1662config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001663 int "MTRR cleanup enable value (0-1)"
1664 range 0 1
1665 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001666 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001667 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001668 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001669
Yinghai Lu12031a62008-05-02 02:40:22 -07001670config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1671 int "MTRR cleanup spare reg num (0-7)"
1672 range 0 7
1673 default "1"
1674 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001675 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001676 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001677 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001678
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001679config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001680 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001681 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001682 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001683 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001684 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001685
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001686 PATs are the modern equivalents of MTRRs and are much more
1687 flexible than MTRRs.
1688
1689 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001690 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001691
1692 If unsure, say Y.
1693
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001694config ARCH_USES_PG_UNCACHED
1695 def_bool y
1696 depends on X86_PAT
1697
H. Peter Anvin628c6242011-07-31 13:59:29 -07001698config ARCH_RANDOM
1699 def_bool y
1700 prompt "x86 architectural random number generator" if EXPERT
1701 ---help---
1702 Enable the x86 architectural RDRAND instruction
1703 (Intel Bull Mountain technology) to generate random numbers.
1704 If supported, this is a high bandwidth, cryptographically
1705 secure hardware random number generator.
1706
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001707config X86_SMAP
1708 def_bool y
1709 prompt "Supervisor Mode Access Prevention" if EXPERT
1710 ---help---
1711 Supervisor Mode Access Prevention (SMAP) is a security
1712 feature in newer Intel processors. There is a small
1713 performance cost if this enabled and turned on; there is
1714 also a small increase in the kernel size if this is enabled.
1715
1716 If unsure, say Y.
1717
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001718config X86_INTEL_MPX
1719 prompt "Intel MPX (Memory Protection Extensions)"
1720 def_bool n
1721 depends on CPU_SUP_INTEL
1722 ---help---
1723 MPX provides hardware features that can be used in
1724 conjunction with compiler-instrumented code to check
1725 memory references. It is designed to detect buffer
1726 overflow or underflow bugs.
1727
1728 This option enables running applications which are
1729 instrumented or otherwise use MPX. It does not use MPX
1730 itself inside the kernel or to protect the kernel
1731 against bad memory references.
1732
1733 Enabling this option will make the kernel larger:
1734 ~8k of kernel text and 36 bytes of data on a 64-bit
1735 defconfig. It adds a long to the 'mm_struct' which
1736 will increase the kernel memory overhead of each
1737 process and adds some branches to paths used during
1738 exec() and munmap().
1739
1740 For details, see Documentation/x86/intel_mpx.txt
1741
1742 If unsure, say N.
1743
Dave Hansen35e97792016-02-12 13:02:00 -08001744config X86_INTEL_MEMORY_PROTECTION_KEYS
Dave Hansen284244a2016-02-12 13:02:28 -08001745 prompt "Intel Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001746 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001747 # Note: only available in 64-bit mode
Dave Hansen35e97792016-02-12 13:02:00 -08001748 depends on CPU_SUP_INTEL && X86_64
Dave Hansen284244a2016-02-12 13:02:28 -08001749 ---help---
1750 Memory Protection Keys provides a mechanism for enforcing
1751 page-based protections, but without requiring modification of the
1752 page tables when an application changes protection domains.
1753
1754 For details, see Documentation/x86/protection-keys.txt
1755
1756 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001757
Michal Hocko0fbf0802019-10-23 12:35:50 +02001758choice
1759 prompt "TSX enable mode"
1760 depends on CPU_SUP_INTEL
1761 default X86_INTEL_TSX_MODE_OFF
1762 help
1763 Intel's TSX (Transactional Synchronization Extensions) feature
1764 allows to optimize locking protocols through lock elision which
1765 can lead to a noticeable performance boost.
1766
1767 On the other hand it has been shown that TSX can be exploited
1768 to form side channel attacks (e.g. TAA) and chances are there
1769 will be more of those attacks discovered in the future.
1770
1771 Therefore TSX is not enabled by default (aka tsx=off). An admin
1772 might override this decision by tsx=on the command line parameter.
1773 Even with TSX enabled, the kernel will attempt to enable the best
1774 possible TAA mitigation setting depending on the microcode available
1775 for the particular machine.
1776
1777 This option allows to set the default tsx mode between tsx=on, =off
1778 and =auto. See Documentation/kernel-parameters.txt for more
1779 details.
1780
1781 Say off if not sure, auto if TSX is in use but it should be used on safe
1782 platforms or on if TSX is in use and the security aspect of tsx is not
1783 relevant.
1784
1785config X86_INTEL_TSX_MODE_OFF
1786 bool "off"
1787 help
1788 TSX is disabled if possible - equals to tsx=off command line parameter.
1789
1790config X86_INTEL_TSX_MODE_ON
1791 bool "on"
1792 help
1793 TSX is always enabled on TSX capable HW - equals the tsx=on command
1794 line parameter.
1795
1796config X86_INTEL_TSX_MODE_AUTO
1797 bool "auto"
1798 help
1799 TSX is enabled on TSX capable HW that is believed to be safe against
1800 side channel attacks- equals the tsx=auto command line parameter.
1801endchoice
1802
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001803config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001804 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001805 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001806 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001807 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001808 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001809 This enables the kernel to use EFI runtime services that are
1810 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001811
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001812 This option is only useful on systems that have EFI firmware.
1813 In addition, you should use the latest ELILO loader available
1814 at <http://elilo.sourceforge.net> in order to take advantage
1815 of EFI runtime services. However, even with this option, the
1816 resultant kernel should continue to boot on existing non-EFI
1817 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001818
Matt Fleming291f3632011-12-12 21:27:52 +00001819config EFI_STUB
1820 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001821 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001822 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001823 ---help---
1824 This kernel feature allows a bzImage to be loaded directly
1825 by EFI firmware without the use of a bootloader.
1826
Roy Franz4172fe22013-09-22 15:45:25 -07001827 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001828
Matt Fleming7d453ee2014-01-10 18:52:06 +00001829config EFI_MIXED
1830 bool "EFI mixed-mode support"
1831 depends on EFI_STUB && X86_64
1832 ---help---
1833 Enabling this feature allows a 64-bit kernel to be booted
1834 on a 32-bit firmware, provided that your CPU supports 64-bit
1835 mode.
1836
1837 Note that it is not possible to boot a mixed-mode enabled
1838 kernel via the EFI boot stub - a bootloader that supports
1839 the EFI handover protocol must be used.
1840
1841 If unsure, say N.
1842
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001843config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001844 def_bool y
1845 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001846 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001847 This kernel feature is useful for number crunching applications
1848 that may need to compute untrusted bytecode during their
1849 execution. By using pipes or other transports made available to
1850 the process as file descriptors supporting the read/write
1851 syscalls, it's possible to isolate those applications in
1852 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001853 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001854 and the task is only allowed to execute a few safe syscalls
1855 defined by each seccomp mode.
1856
1857 If unsure, say Y. Only embedded should say N here.
1858
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001859source kernel/Kconfig.hz
1860
1861config KEXEC
1862 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001863 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001864 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001865 kexec is a system call that implements the ability to shutdown your
1866 current kernel, and to start another kernel. It is like a reboot
1867 but it is independent of the system firmware. And like a reboot
1868 you can start any kernel with it, not just Linux.
1869
1870 The name comes from the similarity to the exec system call.
1871
1872 It is an ongoing process to be certain the hardware in a machine
1873 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001874 initially work for you. As of this writing the exact hardware
1875 interface is strongly in flux, so no good recommendation can be
1876 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001877
Vivek Goyal74ca3172014-08-29 15:18:46 -07001878config KEXEC_FILE
1879 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001880 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001881 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001882 depends on X86_64
1883 depends on CRYPTO=y
1884 depends on CRYPTO_SHA256=y
1885 ---help---
1886 This is new version of kexec system call. This system call is
1887 file based and takes file descriptors as system call argument
1888 for kernel and initramfs as opposed to list of segments as
1889 accepted by previous system call.
1890
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001891config KEXEC_VERIFY_SIG
1892 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001893 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001894 ---help---
1895 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001896 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001897
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001898 In addition to that option, you need to enable signature
1899 verification for the corresponding kernel image type being
1900 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001901
1902config KEXEC_BZIMAGE_VERIFY_SIG
1903 bool "Enable bzImage signature verification support"
1904 depends on KEXEC_VERIFY_SIG
1905 depends on SIGNED_PE_FILE_VERIFICATION
1906 select SYSTEM_TRUSTED_KEYRING
1907 ---help---
1908 Enable bzImage signature verification support.
1909
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001910config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001911 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001912 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001913 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001914 Generate crash dump after being started by kexec.
1915 This should be normally only set in special crash dump kernels
1916 which are loaded in the main kernel with kexec-tools into
1917 a specially reserved region and then later executed after
1918 a crash by kdump/kexec. The crash dump kernel must be compiled
1919 to a memory address not used by the main kernel or BIOS using
1920 PHYSICAL_START, or it must be built as a relocatable image
1921 (CONFIG_RELOCATABLE=y).
1922 For more details see Documentation/kdump/kdump.txt
1923
Huang Ying3ab83522008-07-25 19:45:07 -07001924config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001925 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001926 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001927 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001928 Jump between original kernel and kexeced kernel and invoke
1929 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001930
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001931config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001932 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001933 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001934 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001935 This gives the physical address where the kernel is loaded.
1936
1937 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1938 bzImage will decompress itself to above physical address and
1939 run from there. Otherwise, bzImage will run from the address where
1940 it has been loaded by the boot loader and will ignore above physical
1941 address.
1942
1943 In normal kdump cases one does not have to set/change this option
1944 as now bzImage can be compiled as a completely relocatable image
1945 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1946 address. This option is mainly useful for the folks who don't want
1947 to use a bzImage for capturing the crash dump and want to use a
1948 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1949 to be specifically compiled to run from a specific memory area
1950 (normally a reserved region) and this option comes handy.
1951
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001952 So if you are using bzImage for capturing the crash dump,
1953 leave the value here unchanged to 0x1000000 and set
1954 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1955 for capturing the crash dump change this value to start of
1956 the reserved region. In other words, it can be set based on
1957 the "X" value as specified in the "crashkernel=YM@XM"
1958 command line boot parameter passed to the panic-ed
1959 kernel. Please take a look at Documentation/kdump/kdump.txt
1960 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001961
1962 Usage of bzImage for capturing the crash dump is recommended as
1963 one does not have to build two kernels. Same kernel can be used
1964 as production kernel and capture kernel. Above option should have
1965 gone away after relocatable bzImage support is introduced. But it
1966 is present because there are users out there who continue to use
1967 vmlinux for dump capture. This option should go away down the
1968 line.
1969
1970 Don't change this unless you know what you are doing.
1971
1972config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001973 bool "Build a relocatable kernel"
1974 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001975 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001976 This builds a kernel image that retains relocation information
1977 so it can be loaded someplace besides the default 1MB.
1978 The relocations tend to make the kernel binary about 10% larger,
1979 but are discarded at runtime.
1980
1981 One use is for the kexec on panic case where the recovery kernel
1982 must live at a different physical address than the primary
1983 kernel.
1984
1985 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1986 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001987 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001988
Kees Cook8ab38202013-10-10 17:18:14 -07001989config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07001990 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07001991 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001992 default n
1993 ---help---
Baoquan Hee8581e32016-04-20 13:55:43 -07001994 In support of Kernel Address Space Layout Randomization (KASLR),
1995 this randomizes the physical address at which the kernel image
1996 is decompressed and the virtual address where the kernel
1997 image is mapped, as a security feature that deters exploit
1998 attempts relying on knowledge of the location of kernel
1999 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002000
Kees Cooked9f0072016-05-25 15:45:33 -07002001 On 64-bit, the kernel physical and virtual addresses are
2002 randomized separately. The physical address will be anywhere
2003 between 16MB and the top of physical memory (up to 64TB). The
2004 virtual address will be randomized from 16MB up to 1GB (9 bits
2005 of entropy). Note that this also reduces the memory space
2006 available to kernel modules from 1.5GB to 1GB.
2007
2008 On 32-bit, the kernel physical and virtual addresses are
2009 randomized together. They will be randomized from 16MB up to
2010 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002011
Baoquan Hee8581e32016-04-20 13:55:43 -07002012 Entropy is generated using the RDRAND instruction if it is
2013 supported. If RDTSC is supported, its value is mixed into
2014 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002015 supported, then entropy is read from the i8254 timer. The
2016 usable entropy is limited by the kernel being built using
2017 2GB addressing, and that PHYSICAL_ALIGN must be at a
2018 minimum of 2MB. As a result, only 10 bits of entropy are
2019 theoretically possible, but the implementations are further
2020 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002021
Baoquan Hee8581e32016-04-20 13:55:43 -07002022 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
2023 time. To enable it, boot with "kaslr" on the kernel command
2024 line (which will also disable hibernation).
Kees Cook6145cfe2013-10-10 17:18:18 -07002025
Baoquan Hee8581e32016-04-20 13:55:43 -07002026 If unsure, say N.
Kees Cook8ab38202013-10-10 17:18:14 -07002027
2028# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002029config X86_NEED_RELOCS
2030 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002031 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002032
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002033config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002034 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002035 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002036 range 0x2000 0x1000000 if X86_32
2037 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002038 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002039 This value puts the alignment restrictions on physical address
2040 where kernel is loaded and run from. Kernel is compiled for an
2041 address which meets above alignment restriction.
2042
2043 If bootloader loads the kernel at a non-aligned address and
2044 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2045 address aligned to above value and run from there.
2046
2047 If bootloader loads the kernel at a non-aligned address and
2048 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2049 load address and decompress itself to the address it has been
2050 compiled for and run from there. The address for which kernel is
2051 compiled already meets above alignment restrictions. Hence the
2052 end result is that kernel runs from a physical address meeting
2053 above alignment restrictions.
2054
Kees Cooka0215062013-07-08 09:15:17 -07002055 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2056 this value must be a multiple of 0x200000.
2057
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002058 Don't change this unless you know what you are doing.
2059
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002060config RANDOMIZE_MEMORY
2061 bool "Randomize the kernel memory sections"
2062 depends on X86_64
2063 depends on RANDOMIZE_BASE
2064 default RANDOMIZE_BASE
2065 ---help---
2066 Randomizes the base virtual address of kernel memory sections
2067 (physical memory mapping, vmalloc & vmemmap). This security feature
2068 makes exploits relying on predictable memory locations less reliable.
2069
2070 The order of allocations remains unchanged. Entropy is generated in
2071 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2072 configuration have in average 30,000 different possible virtual
2073 addresses for each memory section.
2074
2075 If unsure, say N.
2076
Thomas Garnier90397a42016-06-21 17:47:06 -07002077config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2078 hex "Physical memory mapping padding" if EXPERT
2079 depends on RANDOMIZE_MEMORY
2080 default "0xa" if MEMORY_HOTPLUG
2081 default "0x0"
2082 range 0x1 0x40 if MEMORY_HOTPLUG
2083 range 0x0 0x40
2084 ---help---
2085 Define the padding in terabytes added to the existing physical
2086 memory size during kernel memory randomization. It is useful
2087 for memory hotplug support but reduces the entropy available for
2088 address randomization.
2089
2090 If unsure, leave at the default value.
2091
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002092config HOTPLUG_CPU
Thomas Gleixner6e9a7142019-03-26 17:36:06 +01002093 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002094 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002095
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002096config BOOTPARAM_HOTPLUG_CPU0
2097 bool "Set default setting of cpu0_hotpluggable"
2098 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08002099 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002100 ---help---
2101 Set whether default state of cpu0_hotpluggable is on or off.
2102
2103 Say Y here to enable CPU0 hotplug by default. If this switch
2104 is turned on, there is no need to give cpu0_hotplug kernel
2105 parameter and the CPU0 hotplug feature is enabled by default.
2106
2107 Please note: there are two known CPU0 dependencies if you want
2108 to enable the CPU0 hotplug feature either by this switch or by
2109 cpu0_hotplug kernel parameter.
2110
2111 First, resume from hibernate or suspend always starts from CPU0.
2112 So hibernate and suspend are prevented if CPU0 is offline.
2113
2114 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2115 offline if any interrupt can not migrate out of CPU0. There may
2116 be other CPU0 dependencies.
2117
2118 Please make sure the dependencies are under your control before
2119 you enable this feature.
2120
2121 Say N if you don't want to enable CPU0 hotplug feature by default.
2122 You still can enable the CPU0 hotplug feature at boot by kernel
2123 parameter cpu0_hotplug.
2124
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002125config DEBUG_HOTPLUG_CPU0
2126 def_bool n
2127 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002128 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002129 ---help---
2130 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2131 soon as possible and boots up userspace with CPU0 offlined. User
2132 can online CPU0 back after boot time.
2133
2134 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2135 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2136 compilation or giving cpu0_hotplug kernel parameter at boot.
2137
2138 If unsure, say N.
2139
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002140config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002141 def_bool n
2142 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002143 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002144 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002145 Certain buggy versions of glibc will crash if they are
2146 presented with a 32-bit vDSO that is not mapped at the address
2147 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002148
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002149 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2150 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2151 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2152 the only released version with the bug, but OpenSUSE 9
2153 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002154
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002155 The symptom of the bug is that everything crashes on startup, saying:
2156 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2157
2158 Saying Y here changes the default value of the vdso32 boot
2159 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2160 This works around the glibc bug but hurts performance.
2161
2162 If unsure, say N: if you are compiling your own kernel, you
2163 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002164
Kees Cook3dc33bd2015-08-12 17:55:19 -07002165choice
2166 prompt "vsyscall table for legacy applications"
2167 depends on X86_64
2168 default LEGACY_VSYSCALL_EMULATE
2169 help
2170 Legacy user code that does not know how to find the vDSO expects
2171 to be able to issue three syscalls by calling fixed addresses in
2172 kernel space. Since this location is not randomized with ASLR,
2173 it can be used to assist security vulnerability exploitation.
2174
2175 This setting can be changed at boot time via the kernel command
2176 line parameter vsyscall=[native|emulate|none].
2177
2178 On a system with recent enough glibc (2.14 or newer) and no
2179 static binaries, you can say None without a performance penalty
2180 to improve security.
2181
2182 If unsure, select "Emulate".
2183
2184 config LEGACY_VSYSCALL_NATIVE
2185 bool "Native"
2186 help
2187 Actual executable code is located in the fixed vsyscall
2188 address mapping, implementing time() efficiently. Since
2189 this makes the mapping executable, it can be used during
2190 security vulnerability exploitation (traditionally as
2191 ROP gadgets). This configuration is not recommended.
2192
2193 config LEGACY_VSYSCALL_EMULATE
2194 bool "Emulate"
2195 help
2196 The kernel traps and emulates calls into the fixed
2197 vsyscall address mapping. This makes the mapping
2198 non-executable, but it still contains known contents,
2199 which could be used in certain rare security vulnerability
2200 exploits. This configuration is recommended when userspace
2201 still uses the vsyscall area.
2202
2203 config LEGACY_VSYSCALL_NONE
2204 bool "None"
2205 help
2206 There will be no vsyscall mapping at all. This will
2207 eliminate any risk of ASLR bypass due to the vsyscall
2208 fixed address mapping. Attempts to use the vsyscalls
2209 will be reported to dmesg, so that either old or
2210 malicious userspace programs can be identified.
2211
2212endchoice
2213
Tim Bird516cbf32008-08-12 12:52:36 -07002214config CMDLINE_BOOL
2215 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002216 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002217 Allow for specifying boot arguments to the kernel at
2218 build time. On some systems (e.g. embedded ones), it is
2219 necessary or convenient to provide some or all of the
2220 kernel boot arguments with the kernel itself (that is,
2221 to not rely on the boot loader to provide them.)
2222
2223 To compile command line arguments into the kernel,
2224 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002225 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002226
2227 Systems with fully functional boot loaders (i.e. non-embedded)
2228 should leave this option set to 'N'.
2229
2230config CMDLINE
2231 string "Built-in kernel command string"
2232 depends on CMDLINE_BOOL
2233 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002234 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002235 Enter arguments here that should be compiled into the kernel
2236 image and used at boot time. If the boot loader provides a
2237 command line at boot time, it is appended to this string to
2238 form the full kernel command line, when the system boots.
2239
2240 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2241 change this behavior.
2242
2243 In most cases, the command line (whether built-in or provided
2244 by the boot loader) should specify the device for the root
2245 file system.
2246
2247config CMDLINE_OVERRIDE
2248 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002249 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002250 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002251 Set this option to 'Y' to have the kernel ignore the boot loader
2252 command line, and use ONLY the built-in command line.
2253
2254 This is used to work around broken boot loaders. This should
2255 be set to 'N' under normal conditions.
2256
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002257config MODIFY_LDT_SYSCALL
2258 bool "Enable the LDT (local descriptor table)" if EXPERT
2259 default y
2260 ---help---
2261 Linux can allow user programs to install a per-process x86
2262 Local Descriptor Table (LDT) using the modify_ldt(2) system
2263 call. This is required to run 16-bit or segmented code such as
2264 DOSEMU or some Wine programs. It is also used by some very old
2265 threading libraries.
2266
2267 Enabling this feature adds a small amount of overhead to
2268 context switches and increases the low-level kernel attack
2269 surface. Disabling it removes the modify_ldt(2) system call.
2270
2271 Saying 'N' here may make sense for embedded or server kernels.
2272
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002273source "kernel/livepatch/Kconfig"
2274
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002275endmenu
2276
2277config ARCH_ENABLE_MEMORY_HOTPLUG
2278 def_bool y
2279 depends on X86_64 || (X86_32 && HIGHMEM)
2280
Gary Hade35551052008-10-31 10:52:03 -07002281config ARCH_ENABLE_MEMORY_HOTREMOVE
2282 def_bool y
2283 depends on MEMORY_HOTPLUG
2284
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002285config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002286 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002287 depends on NUMA
2288
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002289config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2290 def_bool y
2291 depends on X86_64 || X86_PAE
2292
Naoya Horiguchic177c812014-06-04 16:05:35 -07002293config ARCH_ENABLE_HUGEPAGE_MIGRATION
2294 def_bool y
2295 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2296
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002297menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002298
2299config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002300 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002301 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002302
2303source "kernel/power/Kconfig"
2304
2305source "drivers/acpi/Kconfig"
2306
Feng Tangefafc8b2009-08-14 15:23:29 -04002307source "drivers/sfi/Kconfig"
2308
Andi Kleena6b68072008-01-30 13:32:49 +01002309config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002310 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002311 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002312
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002313menuconfig APM
2314 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002315 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002316 ---help---
2317 APM is a BIOS specification for saving power using several different
2318 techniques. This is mostly useful for battery powered laptops with
2319 APM compliant BIOSes. If you say Y here, the system time will be
2320 reset after a RESUME operation, the /proc/apm device will provide
2321 battery status information, and user-space programs will receive
2322 notification of APM "events" (e.g. battery status change).
2323
2324 If you select "Y" here, you can disable actual use of the APM
2325 BIOS by passing the "apm=off" option to the kernel at boot time.
2326
2327 Note that the APM support is almost completely disabled for
2328 machines with more than one CPU.
2329
2330 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002331 and more information, read <file:Documentation/power/apm-acpi.txt>
2332 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002333 <http://www.tldp.org/docs.html#howto>.
2334
2335 This driver does not spin down disk drives (see the hdparm(8)
2336 manpage ("man 8 hdparm") for that), and it doesn't turn off
2337 VESA-compliant "green" monitors.
2338
2339 This driver does not support the TI 4000M TravelMate and the ACER
2340 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2341 desktop machines also don't have compliant BIOSes, and this driver
2342 may cause those machines to panic during the boot phase.
2343
2344 Generally, if you don't have a battery in your machine, there isn't
2345 much point in using this driver and you should say N. If you get
2346 random kernel OOPSes or reboots that don't seem to be related to
2347 anything, try disabling/enabling this option (or disabling/enabling
2348 APM in your BIOS).
2349
2350 Some other things you should try when experiencing seemingly random,
2351 "weird" problems:
2352
2353 1) make sure that you have enough swap space and that it is
2354 enabled.
2355 2) pass the "no-hlt" option to the kernel
2356 3) switch on floating point emulation in the kernel and pass
2357 the "no387" option to the kernel
2358 4) pass the "floppy=nodma" option to the kernel
2359 5) pass the "mem=4M" option to the kernel (thereby disabling
2360 all but the first 4 MB of RAM)
2361 6) make sure that the CPU is not over clocked.
2362 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2363 8) disable the cache from your BIOS settings
2364 9) install a fan for the video card or exchange video RAM
2365 10) install a better fan for the CPU
2366 11) exchange RAM chips
2367 12) exchange the motherboard.
2368
2369 To compile this driver as a module, choose M here: the
2370 module will be called apm.
2371
2372if APM
2373
2374config APM_IGNORE_USER_SUSPEND
2375 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002376 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002377 This option will ignore USER SUSPEND requests. On machines with a
2378 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2379 series notebooks, it is necessary to say Y because of a BIOS bug.
2380
2381config APM_DO_ENABLE
2382 bool "Enable PM at boot time"
2383 ---help---
2384 Enable APM features at boot time. From page 36 of the APM BIOS
2385 specification: "When disabled, the APM BIOS does not automatically
2386 power manage devices, enter the Standby State, enter the Suspend
2387 State, or take power saving steps in response to CPU Idle calls."
2388 This driver will make CPU Idle calls when Linux is idle (unless this
2389 feature is turned off -- see "Do CPU IDLE calls", below). This
2390 should always save battery power, but more complicated APM features
2391 will be dependent on your BIOS implementation. You may need to turn
2392 this option off if your computer hangs at boot time when using APM
2393 support, or if it beeps continuously instead of suspending. Turn
2394 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2395 T400CDT. This is off by default since most machines do fine without
2396 this feature.
2397
2398config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002399 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002400 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002401 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002402 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2403 On some machines, this can activate improved power savings, such as
2404 a slowed CPU clock rate, when the machine is idle. These idle calls
2405 are made after the idle loop has run for some length of time (e.g.,
2406 333 mS). On some machines, this will cause a hang at boot time or
2407 whenever the CPU becomes idle. (On machines with more than one CPU,
2408 this option does nothing.)
2409
2410config APM_DISPLAY_BLANK
2411 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002412 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002413 Enable console blanking using the APM. Some laptops can use this to
2414 turn off the LCD backlight when the screen blanker of the Linux
2415 virtual console blanks the screen. Note that this is only used by
2416 the virtual console screen blanker, and won't turn off the backlight
2417 when using the X Window system. This also doesn't have anything to
2418 do with your VESA-compliant power-saving monitor. Further, this
2419 option doesn't work for all laptops -- it might not turn off your
2420 backlight at all, or it might print a lot of errors to the console,
2421 especially if you are using gpm.
2422
2423config APM_ALLOW_INTS
2424 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002425 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002426 Normally we disable external interrupts while we are making calls to
2427 the APM BIOS as a measure to lessen the effects of a badly behaving
2428 BIOS implementation. The BIOS should reenable interrupts if it
2429 needs to. Unfortunately, some BIOSes do not -- especially those in
2430 many of the newer IBM Thinkpads. If you experience hangs when you
2431 suspend, try setting this to Y. Otherwise, say N.
2432
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002433endif # APM
2434
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002435source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002436
2437source "drivers/cpuidle/Kconfig"
2438
Andy Henroid27471fd2008-10-09 11:45:22 -07002439source "drivers/idle/Kconfig"
2440
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002441endmenu
2442
2443
2444menu "Bus options (PCI etc.)"
2445
2446config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002447 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002448 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002449 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002450 Find out whether you have a PCI motherboard. PCI is the name of a
2451 bus system, i.e. the way the CPU talks to the other stuff inside
2452 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2453 VESA. If you have PCI, say Y, otherwise N.
2454
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002455choice
2456 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002457 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002458 default PCI_GOANY
2459 ---help---
2460 On PCI systems, the BIOS can be used to detect the PCI devices and
2461 determine their configuration. However, some old PCI motherboards
2462 have BIOS bugs and may crash if this is done. Also, some embedded
2463 PCI-based systems don't have any BIOS at all. Linux can also try to
2464 detect the PCI hardware directly without using the BIOS.
2465
2466 With this option, you can specify how Linux should detect the
2467 PCI devices. If you choose "BIOS", the BIOS will be used,
2468 if you choose "Direct", the BIOS won't be used, and if you
2469 choose "MMConfig", then PCI Express MMCONFIG will be used.
2470 If you choose "Any", the kernel will try MMCONFIG, then the
2471 direct access method and falls back to the BIOS if that doesn't
2472 work. If unsure, go with the default, which is "Any".
2473
2474config PCI_GOBIOS
2475 bool "BIOS"
2476
2477config PCI_GOMMCONFIG
2478 bool "MMConfig"
2479
2480config PCI_GODIRECT
2481 bool "Direct"
2482
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002483config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002484 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002485 depends on OLPC
2486
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002487config PCI_GOANY
2488 bool "Any"
2489
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002490endchoice
2491
2492config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002493 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002494 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002495
2496# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2497config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002498 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002499 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002500
2501config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002502 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002503 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002504
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002505config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002506 def_bool y
2507 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002508
Alex Nixonb5401a92010-03-18 16:31:34 -04002509config PCI_XEN
2510 def_bool y
2511 depends on PCI && XEN
2512 select SWIOTLB_XEN
2513
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002514config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002515 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002516 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002517
2518config PCI_MMCONFIG
2519 bool "Support mmconfig PCI config space access"
2520 depends on X86_64 && PCI && ACPI
2521
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002522config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002523 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002524 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002525 help
2526 Read the PCI windows out of the CNB20LE host bridge. This allows
2527 PCI hotplug to work on systems with the CNB20LE chipset which do
2528 not have ACPI.
2529
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002530 There's no public spec for this chipset, and this functionality
2531 is known to be incomplete.
2532
2533 You should say N unless you know you need this.
2534
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002535source "drivers/pci/Kconfig"
2536
William Breathitt Gray3a495512016-05-27 18:08:27 -04002537config ISA_BUS
2538 bool "ISA-style bus support on modern systems" if EXPERT
2539 select ISA_BUS_API
2540 help
2541 Enables ISA-style drivers on modern systems. This is necessary to
2542 support PC/104 devices on X86_64 platforms.
2543
2544 If unsure, say N.
2545
David Rientjes1c00f012011-03-22 16:34:59 -07002546# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002547config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002548 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2549 default y
2550 help
2551 Enables ISA-style DMA support for devices requiring such controllers.
2552 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002553
Linus Torvalds51e68d02016-05-21 10:25:19 -07002554if X86_32
2555
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002556config ISA
2557 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002558 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002559 Find out whether you have ISA slots on your motherboard. ISA is the
2560 name of a bus system, i.e. the way the CPU talks to the other stuff
2561 inside your box. Other bus systems are PCI, EISA, MicroChannel
2562 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2563 newer boards don't support it. If you have ISA, say Y, otherwise N.
2564
2565config EISA
2566 bool "EISA support"
2567 depends on ISA
2568 ---help---
2569 The Extended Industry Standard Architecture (EISA) bus was
2570 developed as an open alternative to the IBM MicroChannel bus.
2571
2572 The EISA bus provided some of the features of the IBM MicroChannel
2573 bus while maintaining backward compatibility with cards made for
2574 the older ISA bus. The EISA bus saw limited use between 1988 and
2575 1995 when it was made obsolete by the PCI bus.
2576
2577 Say Y here if you are building a kernel for an EISA-based machine.
2578
2579 Otherwise, say N.
2580
2581source "drivers/eisa/Kconfig"
2582
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002583config SCx200
2584 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002585 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002586 This provides basic support for National Semiconductor's
2587 (now AMD's) Geode processors. The driver probes for the
2588 PCI-IDs of several on-chip devices, so its a good dependency
2589 for other scx200_* drivers.
2590
2591 If compiled as a module, the driver is named scx200.
2592
2593config SCx200HR_TIMER
2594 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002595 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002596 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002597 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002598 This driver provides a clocksource built upon the on-chip
2599 27MHz high-resolution timer. Its also a workaround for
2600 NSC Geode SC-1100's buggy TSC, which loses time when the
2601 processor goes idle (as is done by the scheduler). The
2602 other workaround is idle=poll boot option.
2603
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002604config OLPC
2605 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002606 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002607 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002608 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002609 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002610 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002611 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002612 Add support for detecting the unique features of the OLPC
2613 XO hardware.
2614
Daniel Drakea3128582011-06-25 17:34:10 +01002615config OLPC_XO1_PM
2616 bool "OLPC XO-1 Power Management"
Borislav Petkov70172bc2018-10-05 15:13:07 +02002617 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002618 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002619 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002620
Daniel Drakecfee9592011-06-25 17:34:17 +01002621config OLPC_XO1_RTC
2622 bool "OLPC XO-1 Real Time Clock"
2623 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2624 ---help---
2625 Add support for the XO-1 real time clock, which can be used as a
2626 programmable wakeup source.
2627
Daniel Drake7feda8e2011-06-25 17:34:12 +01002628config OLPC_XO1_SCI
2629 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002630 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002631 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002632 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002633 select GPIO_CS5535
2634 select MFD_CORE
2635 ---help---
2636 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002637 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002638 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002639 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002640 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002641 - AC adapter status updates
2642 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002643
Daniel Drakea0f30f52011-06-25 17:34:18 +01002644config OLPC_XO15_SCI
2645 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002646 depends on OLPC && ACPI
2647 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002648 ---help---
2649 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2650 - EC-driven system wakeups
2651 - AC adapter status updates
2652 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002653
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002654config ALIX
2655 bool "PCEngines ALIX System Support (LED setup)"
2656 select GPIOLIB
2657 ---help---
2658 This option enables system support for the PCEngines ALIX.
2659 At present this just sets up LEDs for GPIO control on
2660 ALIX2/3/6 boards. However, other system specific setup should
2661 get added here.
2662
2663 Note: You must still enable the drivers for GPIO and LED support
2664 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2665
2666 Note: You have to set alix.force=1 for boards with Award BIOS.
2667
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002668config NET5501
2669 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2670 select GPIOLIB
2671 ---help---
2672 This option enables system support for the Soekris Engineering net5501.
2673
Philip A. Prindeville31970592012-01-14 01:45:39 -07002674config GEOS
2675 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2676 select GPIOLIB
2677 depends on DMI
2678 ---help---
2679 This option enables system support for the Traverse Technologies GEOS.
2680
Vivien Didelot7d029122013-01-04 16:18:14 -05002681config TS5500
2682 bool "Technologic Systems TS-5500 platform support"
2683 depends on MELAN
2684 select CHECK_SIGNATURE
2685 select NEW_LEDS
2686 select LEDS_CLASS
2687 ---help---
2688 This option enables system support for the Technologic Systems TS-5500.
2689
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002690endif # X86_32
2691
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002692config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002693 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002694 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002695
2696source "drivers/pcmcia/Kconfig"
2697
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002698config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002699 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002700 depends on PCI
2701 default n
2702 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002703 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002704 infrastructure code to support RapidIO interconnect devices.
2705
2706source "drivers/rapidio/Kconfig"
2707
David Herrmanne3263ab2013-08-02 14:05:22 +02002708config X86_SYSFB
2709 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2710 help
2711 Firmwares often provide initial graphics framebuffers so the BIOS,
2712 bootloader or kernel can show basic video-output during boot for
2713 user-guidance and debugging. Historically, x86 used the VESA BIOS
2714 Extensions and EFI-framebuffers for this, which are mostly limited
2715 to x86.
2716 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2717 framebuffers so the new generic system-framebuffer drivers can be
2718 used on x86. If the framebuffer is not compatible with the generic
2719 modes, it is adverticed as fallback platform framebuffer so legacy
2720 drivers like efifb, vesafb and uvesafb can pick it up.
2721 If this option is not selected, all system framebuffers are always
2722 marked as fallback platform framebuffers as usual.
2723
2724 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2725 not be able to pick up generic system framebuffers if this option
2726 is selected. You are highly encouraged to enable simplefb as
2727 replacement if you select this option. simplefb can correctly deal
2728 with generic system framebuffers. But you should still keep vesafb
2729 and others enabled as fallback if a system framebuffer is
2730 incompatible with simplefb.
2731
2732 If unsure, say Y.
2733
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002734endmenu
2735
2736
2737menu "Executable file formats / Emulations"
2738
2739source "fs/Kconfig.binfmt"
2740
2741config IA32_EMULATION
2742 bool "IA32 Emulation"
2743 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002744 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002745 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002746 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002747 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002748 Include code to run legacy 32-bit programs under a
2749 64-bit kernel. You should likely turn this on, unless you're
2750 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002751
2752config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002753 tristate "IA32 a.out support"
2754 depends on IA32_EMULATION
2755 ---help---
2756 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002757
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002758config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002759 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002760 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002761 ---help---
2762 Include code to run binaries for the x32 native 32-bit ABI
2763 for 64-bit processors. An x32 process gets access to the
2764 full 64-bit register file and wide data path while leaving
2765 pointers at 32 bits for smaller memory footprint.
2766
2767 You will need a recent binutils (2.22 or later) with
2768 elf32_x86_64 support enabled to compile a kernel with this
2769 option set.
2770
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002771config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002772 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002773 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002774
Jan Beulich3120e252012-09-10 12:41:45 +01002775if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002776config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002777 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002778
2779config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002780 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002781 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002782endif
David Howellsee009e4a02011-03-07 15:06:20 +00002783
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002784endmenu
2785
2786
Keith Packarde5beae12008-11-03 18:21:45 +01002787config HAVE_ATOMIC_IOMAP
2788 def_bool y
2789 depends on X86_32
2790
Alessandro Rubini4692d772012-04-04 19:39:58 +02002791config X86_DEV_DMA_OPS
2792 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002793 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002794
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002795config X86_DMA_REMAP
2796 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002797 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002798
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002799config PMC_ATOM
2800 def_bool y
2801 depends on PCI
2802
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002803source "net/Kconfig"
2804
2805source "drivers/Kconfig"
2806
2807source "drivers/firmware/Kconfig"
2808
2809source "fs/Kconfig"
2810
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002811source "arch/x86/Kconfig.debug"
2812
2813source "security/Kconfig"
2814
2815source "crypto/Kconfig"
2816
Avi Kivityedf88412007-12-16 11:02:48 +02002817source "arch/x86/kvm/Kconfig"
2818
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002819source "lib/Kconfig"