blob: 07459a6b417d0ccbbc69e664dc6ea091fd1bd9c1 [file] [log] [blame]
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01001# Select 32 or 64 bit
2config 64BIT
Sam Ravnborg68409992007-11-17 15:37:31 +01003 bool "64-bit kernel" if ARCH = "x86"
David Woodhouseffee0de2012-12-20 21:51:55 +00004 default ARCH != "i386"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01005 ---help---
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01006 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010010 def_bool y
11 depends on !64BIT
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010012
13config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010014 def_bool y
15 depends on 64BIT
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010016
17### Arch settings
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010018config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010019 def_bool y
Ingo Molnar6471b822015-06-03 10:00:13 +020020 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Stephen Boyd446f24d2013-04-30 15:28:42 -070026 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
Ingo Molnar6471b822015-06-03 10:00:13 +020027 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070028 select ARCH_HAS_FAST_MULTIPLIER
Riku Voipio957e3fa2014-12-12 16:57:44 -080029 select ARCH_HAS_GCOV_PROFILE_ALL
Dan Williams96601ad2015-08-24 18:29:38 -040030 select ARCH_HAS_PMEM_API if X86_64
Ross Zwisler67a3e8f2015-08-27 13:14:20 -060031 select ARCH_HAS_MMIO_FLUSH
Ingo Molnar6471b822015-06-03 10:00:13 +020032 select ARCH_HAS_SG_CHAIN
33 select ARCH_HAVE_NMI_SAFE_CMPXCHG
34 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040035 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080036 select ARCH_MIGHT_HAVE_PC_SERIO
Ingo Molnar6471b822015-06-03 10:00:13 +020037 select ARCH_SUPPORTS_ATOMIC_RMW
Mel Gorman3b242c62015-06-30 14:57:13 -070038 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
Ingo Molnar6471b822015-06-03 10:00:13 +020039 select ARCH_SUPPORTS_INT128 if X86_64
40 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
41 select ARCH_USE_BUILTIN_BSWAP
42 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_USE_QUEUED_SPINLOCKS
Mel Gorman72b252a2015-09-04 15:47:32 -070045 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +020046 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Ingo Molnarda4276b2009-01-07 11:05:10 +010047 select ARCH_WANT_FRAME_POINTERS
Ingo Molnar6471b822015-06-03 10:00:13 +020048 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
49 select ARCH_WANT_OPTIONAL_GPIOLIB
50 select BUILDTIME_EXTABLE_SORT
51 select CLKEVT_I8253
52 select CLKSRC_I8253 if X86_32
53 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
54 select CLOCKSOURCE_WATCHDOG
55 select CLONE_BACKWARDS if X86_32
56 select COMPAT_OLD_SIGACTION if IA32_EMULATION
57 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -070058 select EDAC_ATOMIC_SCRUB
59 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +020060 select GENERIC_CLOCKEVENTS
61 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
62 select GENERIC_CLOCKEVENTS_MIN_ADJUST
63 select GENERIC_CMOS_UPDATE
64 select GENERIC_CPU_AUTOPROBE
65 select GENERIC_EARLY_IOREMAP
66 select GENERIC_FIND_FIRST_BIT
67 select GENERIC_IOMAP
68 select GENERIC_IRQ_PROBE
69 select GENERIC_IRQ_SHOW
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_SMP_IDLE_THREAD
72 select GENERIC_STRNCPY_FROM_USER
73 select GENERIC_STRNLEN_USER
74 select GENERIC_TIME_VSYSCALL
75 select HAVE_ACPI_APEI if ACPI
76 select HAVE_ACPI_APEI_NMI if ACPI
77 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
78 select HAVE_AOUT if X86_32
79 select HAVE_ARCH_AUDITSYSCALL
80 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
81 select HAVE_ARCH_JUMP_LABEL
82 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
83 select HAVE_ARCH_KGDB
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_ARCH_SECCOMP_FILTER
86 select HAVE_ARCH_SOFT_DIRTY if X86_64
87 select HAVE_ARCH_TRACEHOOK
88 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
89 select HAVE_BPF_JIT if X86_64
90 select HAVE_CC_STACKPROTECTOR
91 select HAVE_CMPXCHG_DOUBLE
92 select HAVE_CMPXCHG_LOCAL
93 select HAVE_CONTEXT_TRACKING if X86_64
Josh Triplettc1bd55f2015-06-30 15:00:00 -070094 select HAVE_COPY_THREAD_TLS
Ingo Molnar6471b822015-06-03 10:00:13 +020095 select HAVE_C_RECORDMCOUNT
96 select HAVE_DEBUG_KMEMLEAK
97 select HAVE_DEBUG_STACKOVERFLOW
98 select HAVE_DMA_API_DEBUG
FUJITA Tomonori7c095e42009-06-17 16:28:12 -070099 select HAVE_DMA_ATTRS
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700100 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400101 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900102 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Johannes Berg58340a02008-07-25 01:45:33 -0700103 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select HAVE_FENTRY if X86_64
105 select HAVE_FTRACE_MCOUNT_RECORD
106 select HAVE_FUNCTION_GRAPH_FP_TEST
107 select HAVE_FUNCTION_GRAPH_TRACER
108 select HAVE_FUNCTION_TRACER
109 select HAVE_GENERIC_DMA_COHERENT if X86_32
K.Prasad0067f122009-06-01 23:43:57 +0530110 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200111 select HAVE_IDE
112 select HAVE_IOREMAP_PROT
113 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
114 select HAVE_IRQ_TIME_ACCOUNTING
115 select HAVE_KERNEL_BZIP2
116 select HAVE_KERNEL_GZIP
117 select HAVE_KERNEL_LZ4
118 select HAVE_KERNEL_LZMA
119 select HAVE_KERNEL_LZO
120 select HAVE_KERNEL_XZ
121 select HAVE_KPROBES
122 select HAVE_KPROBES_ON_FTRACE
123 select HAVE_KRETPROBES
124 select HAVE_KVM
125 select HAVE_LIVEPATCH if X86_64
126 select HAVE_MEMBLOCK
127 select HAVE_MEMBLOCK_NODE_MAP
Frederic Weisbecker01027522010-04-11 18:55:56 +0200128 select HAVE_MIXED_BREAKPOINTS_REGS
Ingo Molnar6471b822015-06-03 10:00:13 +0200129 select HAVE_OPROFILE
130 select HAVE_OPTPROBES
131 select HAVE_PCSPKR_PLATFORM
132 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200133 select HAVE_PERF_EVENTS_NMI
Jiri Olsac5e63192012-08-07 15:20:36 +0200134 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200135 select HAVE_PERF_USER_STACK_DUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200136 select HAVE_REGS_AND_STACK_ACCESS_API
137 select HAVE_SYSCALL_TRACEPOINTS
Brian Gerst0c3619e2015-06-22 07:55:20 -0400138 select HAVE_UID16 if X86_32 || IA32_EMULATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200139 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300140 select HAVE_USER_RETURN_NOTIFIER
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100141 select IRQ_FORCED_THREADING
Ingo Molnar6471b822015-06-03 10:00:13 +0200142 select MODULES_USE_ELF_RELA if X86_64
143 select MODULES_USE_ELF_REL if X86_32
144 select OLD_SIGACTION if X86_32
145 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
146 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500147 select RTC_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200148 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500149 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200150 select SYSCTL_EXCEPTION_TRACE
151 select USER_STACKTRACE_SUPPORT
152 select VIRT_TO_BUS
153 select X86_DEV_DMA_OPS if X86_64
154 select X86_FEATURE_NAMES if PROC_FS
Balbir Singh7d8330a2008-02-10 12:46:28 +0530155
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200156config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100157 def_bool y
158 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200159
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200160config PERF_EVENTS_INTEL_UNCORE
161 def_bool y
Peter Zijlstra (Intel)ce5686d2014-10-29 11:17:04 +0100162 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
Peter Zijlstra7fb0f1d2014-10-24 09:12:35 +0200163
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700164config OUTPUT_FORMAT
165 string
166 default "elf32-i386" if X86_32
167 default "elf64-x86-64" if X86_64
168
Sam Ravnborg73531902008-05-25 23:03:18 +0200169config ARCH_DEFCONFIG
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200170 string
Sam Ravnborg73531902008-05-25 23:03:18 +0200171 default "arch/x86/configs/i386_defconfig" if X86_32
172 default "arch/x86/configs/x86_64_defconfig" if X86_64
Sam Ravnborgb9b39bf2008-04-29 12:48:15 +0200173
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100174config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100175 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100176
177config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100178 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100179
Heiko Carstensaa7d9352008-02-01 17:45:14 +0100180config HAVE_LATENCYTOP_SUPPORT
181 def_bool y
182
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100183config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100184 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100185
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100186config SBUS
187 bool
188
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800189config NEED_DMA_MAP_STATE
Jan Beulich3120e252012-09-10 12:41:45 +0100190 def_bool y
Konrad Rzeszutek Wilka6dfa122015-04-17 15:04:48 -0400191 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
FUJITA Tomonori3bc4e452010-03-10 15:23:22 -0800192
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700193config NEED_SG_DMA_LENGTH
Andrew Morton4a14d842010-05-26 14:44:33 -0700194 def_bool y
FUJITA Tomonori18e98302010-05-26 14:44:32 -0700195
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100196config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100197 def_bool y
198 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100199
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100200config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100201 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100202 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000203 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
204
205config GENERIC_BUG_RELATIVE_POINTERS
206 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100207
208config GENERIC_HWEIGHT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100209 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100210
211config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100212 def_bool y
213 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100214
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100215config RWSEM_XCHGADD_ALGORITHM
Jan Beulich3120e252012-09-10 12:41:45 +0100216 def_bool y
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100217
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100218config GENERIC_CALIBRATE_DELAY
219 def_bool y
220
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800221config ARCH_HAS_CPU_RELAX
222 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100223
Pekka Enberg1b27d052008-04-28 02:12:22 -0700224config ARCH_HAS_CACHE_LINE_SIZE
225 def_bool y
226
Mike Travisdd5af902008-01-30 13:33:32 +0100227config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900228 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100229
Tejun Heo08fc4582009-08-14 15:00:49 +0900230config NEED_PER_CPU_EMBED_FIRST_CHUNK
231 def_bool y
232
233config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900234 def_bool y
235
Johannes Berg801e4062007-12-08 02:12:39 +0100236config ARCH_HIBERNATION_POSSIBLE
237 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100238
Johannes Bergf4cb5702007-12-08 02:14:00 +0100239config ARCH_SUSPEND_POSSIBLE
240 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100241
Steve Cappercfe28c52013-04-29 14:29:48 +0100242config ARCH_WANT_HUGE_PMD_SHARE
243 def_bool y
244
Steve Capper53313b22013-04-30 08:03:42 +0100245config ARCH_WANT_GENERAL_HUGETLB
246 def_bool y
247
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100248config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000249 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100250
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100251config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000252 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100253
Ingo Molnar765c68b2008-04-09 11:03:37 +0200254config ARCH_SUPPORTS_OPTIMIZED_INLINING
255 def_bool y
256
Akinobu Mita6a11f752009-03-31 15:23:17 -0700257config ARCH_SUPPORTS_DEBUG_PAGEALLOC
258 def_bool y
259
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300260config KASAN_SHADOW_OFFSET
261 hex
262 depends on KASAN
263 default 0xdffffc0000000000
264
Shane Wang69575d32009-09-01 18:25:07 -0700265config HAVE_INTEL_TXT
266 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700267 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700268
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100269config X86_32_SMP
270 def_bool y
271 depends on X86_32 && SMP
272
273config X86_64_SMP
274 def_bool y
275 depends on X86_64 && SMP
276
Tejun Heoccbeed32009-02-09 22:17:40 +0900277config X86_32_LAZY_GS
278 def_bool y
Tejun Heo60a53172009-02-09 22:17:40 +0900279 depends on X86_32 && !CC_STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900280
Borislav Petkovd61931d2010-03-05 17:34:46 +0100281config ARCH_HWEIGHT_CFLAGS
282 string
283 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
284 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
285
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530286config ARCH_SUPPORTS_UPROBES
287 def_bool y
288
Rob Herringd20642f2014-04-18 17:19:54 -0500289config FIX_EARLYCON_MEM
290 def_bool y
291
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700292config PGTABLE_LEVELS
293 int
294 default 4 if X86_64
295 default 3 if X86_PAE
296 default 2
297
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100298source "init/Kconfig"
Matt Helsleydc52ddc2008-10-18 20:27:21 -0700299source "kernel/Kconfig.freezer"
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100300
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100301menu "Processor type and features"
302
Randy Dunlap5ee71532012-01-16 11:57:18 -0800303config ZONE_DMA
304 bool "DMA memory allocation support" if EXPERT
305 default y
306 help
307 DMA memory allocation support allows devices with less than 32-bit
308 addressing to allocate within the first 16MB of address space.
309 Disable if no such devices will be used.
310
311 If unsure, say Y.
312
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100313config SMP
314 bool "Symmetric multi-processing support"
315 ---help---
316 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800317 a system with only one CPU, say N. If you have a system with more
318 than one CPU, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100319
Robert Graffham4a474152014-01-23 15:55:29 -0800320 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100321 machines, but will use only one CPU of a multiprocessor machine. If
322 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800323 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100324 will run faster if you say N here.
325
326 Note that if you say Y here and choose architecture "586" or
327 "Pentium" under "Processor family", the kernel will not work on 486
328 architectures. Similarly, multiprocessor kernels for the "PPro"
329 architecture may not work on all Pentium based boards.
330
331 People using multiprocessor machines who say Y here should also say
332 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
333 Management" code will be disabled if you say Y here.
334
Paul Bolle395cf962011-08-15 02:02:26 +0200335 See also <file:Documentation/x86/i386/IO-APIC.txt>,
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100336 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
337 <http://www.tldp.org/docs.html#howto>.
338
339 If you don't know what to do here, say N.
340
Josh Triplett9def39be2013-10-30 08:09:45 -0700341config X86_FEATURE_NAMES
342 bool "Processor feature human-readable names" if EMBEDDED
343 default y
344 ---help---
345 This option compiles in a table of x86 feature bits and corresponding
346 names. This is required to support /proc/cpuinfo and a few kernel
347 messages. You can disable this to save space, at the expense of
348 making those few kernel messages show numeric feature bits instead.
349
350 If in doubt, say Y.
351
Borislav Petkov6e1315f2015-12-07 10:39:42 +0100352config X86_FAST_FEATURE_TESTS
353 bool "Fast CPU feature tests" if EMBEDDED
354 default y
355 ---help---
356 Some fast-paths in the kernel depend on the capabilities of the CPU.
357 Say Y here for the kernel to patch in the appropriate code at runtime
358 based on the capabilities of the CPU. The infrastructure for patching
359 code at runtime takes up some additional space; space-constrained
360 embedded systems may wish to say N here to produce smaller, slightly
361 slower code.
362
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800363config X86_X2APIC
364 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200365 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800366 ---help---
367 This enables x2apic support on CPUs that have this feature.
368
369 This allows 32-bit apic IDs (so it can support very large systems),
370 and accesses the local apic via MSRs not via mmio.
371
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800372 If you don't know what to do here, say N.
373
Yinghai Lu6695c852008-06-19 12:13:09 -0700374config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700375 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000376 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200377 depends on X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100378 ---help---
Yinghai Lu6695c852008-06-19 12:13:09 -0700379 For old smp systems that do not have proper acpi support. Newer systems
380 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700381
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800382config X86_BIGSMP
383 bool "Support for big SMP systems with more than 8 CPUs"
384 depends on X86_32 && SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100385 ---help---
Yinghai Lu26f7ef12009-01-29 14:19:22 -0800386 This option is needed for the systems that have more than 8 CPUs
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100387
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000388config GOLDFISH
389 def_bool y
390 depends on X86_GOLDFISH
391
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800392if X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800393config X86_EXTENDED_PLATFORM
394 bool "Support for extended (non-PC) x86 platforms"
395 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100396 ---help---
Ingo Molnar06ac8342009-01-27 18:11:43 +0100397 If you disable this option then the kernel will only support
398 standard PC platforms. (which covers the vast majority of
399 systems out there.)
400
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800401 If you enable this option then you'll be able to select support
402 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100403 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800404 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800405 RDC R-321x SoC
406 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200407 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200408 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100409
410 If you have one of these systems, or if you want to build a
411 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800412endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100413
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800414if X86_64
415config X86_EXTENDED_PLATFORM
416 bool "Support for extended (non-PC) x86 platforms"
417 default y
418 ---help---
419 If you disable this option then the kernel will only support
420 standard PC platforms. (which covers the vast majority of
421 systems out there.)
422
423 If you enable this option then you'll be able to select support
424 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b2011-12-06 00:07:26 +0800425 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800426 ScaleMP vSMP
427 SGI Ultraviolet
428
429 If you have one of these systems, or if you want to build a
430 generic distribution kernel, say Y here - otherwise say N.
431endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800432# This is an alphabetically sorted list of 64 bit extended platforms
433# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b2011-12-06 00:07:26 +0800434config X86_NUMACHIP
435 bool "Numascale NumaChip"
436 depends on X86_64
437 depends on X86_EXTENDED_PLATFORM
438 depends on NUMA
439 depends on SMP
440 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700441 depends on PCI_MMCONFIG
Steffen Persvold44b111b2011-12-06 00:07:26 +0800442 ---help---
443 Adds support for Numascale NumaChip large-SMP systems. Needed to
444 enable more than ~168 cores.
445 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100446
Ingo Molnar6a485652009-01-27 18:29:13 +0100447config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800448 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100449 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100450 select PARAVIRT
451 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800452 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300453 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100454 ---help---
Ingo Molnar6a485652009-01-27 18:29:13 +0100455 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
456 supposed to run on these EM64T-based machines. Only choose this option
457 if you have one of these machines.
458
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800459config X86_UV
460 bool "SGI Ultraviolet"
461 depends on X86_64
462 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500463 depends on NUMA
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700464 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200465 depends on PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800466 ---help---
467 This option is needed in order to support SGI Ultraviolet systems.
468 If you don't have one of these, you should say N here.
469
470# Following is an alphabetically sorted list of 32 bit extended platforms
471# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100472
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000473config X86_GOLDFISH
474 bool "Goldfish (Virtual Platform)"
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100475 depends on X86_EXTENDED_PLATFORM
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000476 ---help---
477 Enable support for the Goldfish virtual platform used primarily
478 for Android development. Unless you are building for the Android
479 Goldfish emulator say N here.
480
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800481config X86_INTEL_CE
482 bool "CE4100 TV platform"
483 depends on PCI
484 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800485 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800486 depends on X86_32
487 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800488 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100489 select OF
490 select OF_EARLY_FLATTREE
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800491 ---help---
492 Select for the Intel CE media processor (CE4100) SOC.
493 This option compiles in support for the CE4100 SOC for settop
494 boxes and media devices.
495
David Cohen4cb9b002013-12-16 17:37:26 -0800496config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100497 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100498 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800499 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000500 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200501 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000502 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000503 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800504 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000505 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000506 select APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000507 select INTEL_SCU_IPC
Mika Westerberg15a713d2012-01-26 17:35:05 +0000508 select MFD_INTEL_MSIC
Alan Cox1ea7c672011-11-10 13:29:14 +0000509 ---help---
David Cohen4cb9b002013-12-16 17:37:26 -0800510 Select to build a kernel capable of supporting Intel MID (Mobile
511 Internet Device) platform systems which do not have the PCI legacy
512 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000513
David Cohen4cb9b002013-12-16 17:37:26 -0800514 Intel MID platforms are based on an Intel processor and chipset which
515 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100516
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000517config X86_INTEL_QUARK
518 bool "Intel Quark platform support"
519 depends on X86_32
520 depends on X86_EXTENDED_PLATFORM
521 depends on X86_PLATFORM_DEVICES
522 depends on X86_TSC
523 depends on PCI
524 depends on PCI_GOANY
525 depends on X86_IO_APIC
526 select IOSF_MBI
527 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200528 select COMMON_CLK
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000529 ---help---
530 Select to include support for Quark X1000 SoC.
531 Say Y here if you have a Quark based system such as the Arduino
532 compatible Intel Galileo.
533
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000534config X86_INTEL_LPSS
535 bool "Intel Low Power Subsystem Support"
536 depends on ACPI
537 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300538 select PINCTRL
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000539 ---help---
540 Select to build support for Intel Low Power Subsystem such as
541 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300542 things like clock tree (common clock framework) and pincontrol
543 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000544
Ken Xue92082a82015-02-06 08:27:51 +0800545config X86_AMD_PLATFORM_DEVICE
546 bool "AMD ACPI2Platform devices support"
547 depends on ACPI
548 select COMMON_CLK
549 select PINCTRL
550 ---help---
551 Select to interpret AMD specific ACPI device to platform device
552 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
553 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
554 implemented under PINCTRL subsystem.
555
David E. Boxced3ce72014-09-17 22:13:50 -0700556config IOSF_MBI
557 tristate "Intel SoC IOSF Sideband support for SoC platforms"
558 depends on PCI
559 ---help---
560 This option enables sideband register access support for Intel SoC
561 platforms. On these platforms the IOSF sideband is used in lieu of
562 MSR's for some register accesses, mostly but not limited to thermal
563 and power. Drivers may query the availability of this device to
564 determine if they need the sideband in order to work on these
565 platforms. The sideband is available on the following SoC products.
566 This list is not meant to be exclusive.
567 - BayTrail
568 - Braswell
569 - Quark
570
571 You should say Y if you are running a kernel on one of these SoC's.
572
David E. Boxed2226b2014-09-17 22:13:51 -0700573config IOSF_MBI_DEBUG
574 bool "Enable IOSF sideband access through debugfs"
575 depends on IOSF_MBI && DEBUG_FS
576 ---help---
577 Select this option to expose the IOSF sideband access registers (MCR,
578 MDR, MCRX) through debugfs to write and read register information from
579 different units on the SoC. This is most useful for obtaining device
580 state information for debug and analysis. As this is a general access
581 mechanism, users of this option would have specific knowledge of the
582 device they want to access.
583
584 If you don't require the option or are in doubt, say N.
585
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800586config X86_RDC321X
587 bool "RDC R-321x SoC"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100588 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800589 depends on X86_EXTENDED_PLATFORM
590 select M486
591 select X86_REBOOTFIXUPS
592 ---help---
593 This option is needed for RDC R-321x system-on-chip, also known
594 as R-8610-(G).
595 If you don't have one of these chips, you should say N here.
596
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100597config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100598 bool "Support non-standard 32-bit SMP architectures"
599 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800600 depends on X86_EXTENDED_PLATFORM
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100601 ---help---
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800602 This option compiles in the bigsmp and STA2X11 default
603 subarchitectures. It is intended for a generic binary
604 kernel. If you select them all, kernel will probe it one by
605 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700606
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800607# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700608
Linus Torvaldsd949f362009-09-26 09:35:07 -0700609config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100610 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700611 # MCE code calls memory_failure():
612 depends on X86_MCE
613 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700614 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
615 depends on X86_64 || !SPARSEMEM
616 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700617
Alessandro Rubini83125a32012-04-04 19:40:21 +0200618config STA2X11
619 bool "STA2X11 Companion Chip Support"
620 depends on X86_32_NON_STANDARD && PCI
621 select X86_DEV_DMA_OPS
622 select X86_DMA_REMAP
623 select SWIOTLB
624 select MFD_STA2X11
625 select ARCH_REQUIRE_GPIOLIB
626 default n
627 ---help---
628 This adds support for boards based on the STA2X11 IO-Hub,
629 a.k.a. "ConneXt". The chip is used in place of the standard
630 PC chipset, so all "standard" peripherals are missing. If this
631 option is selected the kernel will still be able to boot on
632 standard PC machines.
633
Shérab82148d12010-09-25 06:06:57 +0200634config X86_32_IRIS
635 tristate "Eurobraille/Iris poweroff module"
636 depends on X86_32
637 ---help---
638 The Iris machines from EuroBraille do not have APM or ACPI support
639 to shut themselves down properly. A special I/O sequence is
640 needed to do so, which is what this module does at
641 kernel shutdown.
642
643 This is only for Iris machines from EuroBraille.
644
645 If unused, say N.
646
Ingo Molnarae1e9132008-11-11 09:05:16 +0100647config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100648 def_bool y
649 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800650 depends on X86
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100651 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100652 Calculate simpler /proc/<PID>/wchan values. If this option
653 is disabled then wchan values will recurse back to the
654 caller function. This provides more accurate wchan values,
655 at the expense of slightly more scheduling overhead.
656
657 If in doubt, say "Y".
658
Borislav Petkov6276a072013-03-04 21:20:21 +0100659menuconfig HYPERVISOR_GUEST
660 bool "Linux guest support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100661 ---help---
Borislav Petkov6276a072013-03-04 21:20:21 +0100662 Say Y here to enable options for running Linux under various hyper-
663 visors. This option enables basic hypervisor detection and platform
664 setup.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100665
Borislav Petkov6276a072013-03-04 21:20:21 +0100666 If you say N, all options in this submenu will be skipped and
667 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100668
Borislav Petkov6276a072013-03-04 21:20:21 +0100669if HYPERVISOR_GUEST
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100670
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100671config PARAVIRT
672 bool "Enable paravirtualization code"
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100673 ---help---
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100674 This changes the kernel so it can modify itself when it is run
675 under a hypervisor, potentially improving performance significantly
676 over full virtualization. However, when run without a hypervisor
677 the kernel is theoretically slower and slightly larger.
678
Borislav Petkov6276a072013-03-04 21:20:21 +0100679config PARAVIRT_DEBUG
680 bool "paravirt-ops debugging"
681 depends on PARAVIRT && DEBUG_KERNEL
682 ---help---
683 Enable to debug paravirt_ops internals. Specifically, BUG if
684 a paravirt_op is missing when it is called.
685
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700686config PARAVIRT_SPINLOCKS
687 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700688 depends on PARAVIRT && SMP
Ingo Molnar62c7a1e2015-05-11 09:47:23 +0200689 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700690 ---help---
691 Paravirtualized spinlocks allow a pvops backend to replace the
692 spinlock implementation with something virtualization-friendly
693 (for example, block the virtual CPU rather than spinning).
694
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530695 It has a minimal impact on native kernels and gives a nice performance
696 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700697
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530698 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700699
Waiman Long45e898b2015-11-09 19:09:25 -0500700config QUEUED_LOCK_STAT
701 bool "Paravirt queued spinlock statistics"
702 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
703 ---help---
704 Enable the collection of statistical data on the slowpath
705 behavior of paravirtualized queued spinlocks and report
706 them on debugfs.
707
Borislav Petkov6276a072013-03-04 21:20:21 +0100708source "arch/x86/xen/Kconfig"
709
710config KVM_GUEST
711 bool "KVM Guest support (including kvmclock)"
712 depends on PARAVIRT
713 select PARAVIRT_CLOCK
714 default y
715 ---help---
716 This option enables various optimizations for running under the KVM
717 hypervisor. It includes a paravirtualized clock, so that instead
718 of relying on a PIT (or probably other) emulation by the
719 underlying device model, the host provides the guest with
720 timing infrastructure such as time of day, and system time
721
Srivatsa Vaddagiri1e20eb82013-08-09 19:52:01 +0530722config KVM_DEBUG_FS
723 bool "Enable debug information for KVM Guests in debugfs"
724 depends on KVM_GUEST && DEBUG_FS
725 default n
726 ---help---
727 This option enables collection of various statistics for KVM guest.
728 Statistics are displayed in debugfs filesystem. Enabling this option
729 may incur significant overhead.
730
Borislav Petkov6276a072013-03-04 21:20:21 +0100731source "arch/x86/lguest/Kconfig"
732
733config PARAVIRT_TIME_ACCOUNTING
734 bool "Paravirtual steal time accounting"
735 depends on PARAVIRT
736 default n
737 ---help---
738 Select this option to enable fine granularity task steal time
739 accounting. Time spent executing other tasks in parallel with
740 the current vCPU is discounted from the vCPU power. To account for
741 that, there can be a small performance impact.
742
743 If in doubt, say N here.
744
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200745config PARAVIRT_CLOCK
746 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200747
Borislav Petkov6276a072013-03-04 21:20:21 +0100748endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400749
Yinghai Lu08677212010-02-10 01:20:20 -0800750config NO_BOOTMEM
Yinghai Lu774ea0b2010-08-25 13:39:18 -0700751 def_bool y
Yinghai Lu08677212010-02-10 01:20:20 -0800752
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100753source "arch/x86/Kconfig.cpu"
754
755config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100756 def_bool X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100757 prompt "HPET Timer Support" if X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100758 ---help---
759 Use the IA-PC HPET (High Precision Event Timer) to manage
760 time in preference to the PIT and RTC, if a HPET is
761 present.
762 HPET is the next generation timer replacing legacy 8254s.
763 The HPET provides a stable time base on SMP
764 systems, unlike the TSC, but it is more expensive to access,
765 as it is off-chip. You can find the HPET spec at
766 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100767
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100768 You can safely choose Y here. However, HPET will only be
769 activated if the platform and the BIOS support this feature.
770 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100771
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100772 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100773
774config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100775 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800776 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100777
Jacob Panbb24c472009-09-02 07:37:17 -0700778config APB_TIMER
Alan Cox933b9462011-12-17 17:43:40 +0000779 def_bool y if X86_INTEL_MID
780 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
Jamie Iles06c3df42011-06-06 12:43:07 +0100781 select DW_APB_TIMER
Alan Coxa0c38322011-12-17 21:57:25 +0000782 depends on X86_INTEL_MID && SFI
Jacob Panbb24c472009-09-02 07:37:17 -0700783 help
784 APB timer is the replacement for 8254, HPET on X86 MID platforms.
785 The APBT provides a stable time base on SMP
786 systems, unlike the TSC, but it is more expensive to access,
787 as it is off-chip. APB timers are always running regardless of CPU
788 C states, they are used as per CPU clockevent device when possible.
789
David Rientjes6a108a12011-01-20 14:44:16 -0800790# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100791# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700792config DMI
793 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800794 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800795 bool "Enable DMI scanning" if EXPERT
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100796 ---help---
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700797 Enabled scanning of DMI to identify machine quirks. Say Y
798 here unless you have verified that your setup is not
799 affected by entries in the DMI blacklist. Required by PNP
800 BIOS code.
801
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100802config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700803 bool "Old AMD GART IOMMU support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100804 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200805 depends on X86_64 && PCI && AMD_NB
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100806 ---help---
Ingo Molnarced3c422013-10-06 11:45:20 +0200807 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
808 GART based hardware IOMMUs.
809
810 The GART supports full DMA access for devices with 32-bit access
811 limitations, on systems with more than 3 GB. This is usually needed
812 for USB, sound, many IDE/SATA chipsets and some other devices.
813
814 Newer systems typically have a modern AMD IOMMU, supported via
815 the CONFIG_AMD_IOMMU=y config option.
816
817 In normal configurations this driver is only active when needed:
818 there's more than 3 GB of memory and the system contains a
819 32-bit limited device.
820
821 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100822
823config CALGARY_IOMMU
824 bool "IBM Calgary IOMMU support"
825 select SWIOTLB
Kees Cook6ea30382012-10-02 11:16:47 -0700826 depends on X86_64 && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100827 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100828 Support for hardware IOMMUs in IBM's xSeries x366 and x460
829 systems. Needed to run systems with more than 3GB of memory
830 properly with 32-bit PCI devices that do not support DAC
831 (Double Address Cycle). Calgary also supports bus level
832 isolation, where all DMAs pass through the IOMMU. This
833 prevents them from going anywhere except their intended
834 destination. This catches hard-to-find kernel bugs and
835 mis-behaving drivers and devices that do not use the DMA-API
836 properly to set up their DMA buffers. The IOMMU can be
837 turned off at boot time with the iommu=off parameter.
838 Normally the kernel will make the right choice by itself.
839 If unsure, say Y.
840
841config CALGARY_IOMMU_ENABLED_BY_DEFAULT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100842 def_bool y
843 prompt "Should Calgary be enabled by default?"
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100844 depends on CALGARY_IOMMU
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100845 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100846 Should Calgary be enabled by default? if you choose 'y', Calgary
847 will be used (if it exists). If you choose 'n', Calgary will not be
848 used even if it exists. If you choose 'n' and would like to use
849 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
850 If unsure, say Y.
851
852# need this always selected by IOMMU for the VIA workaround
853config SWIOTLB
Joerg Roedela1afd012008-11-18 12:44:21 +0100854 def_bool y if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100855 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100856 Support for software bounce buffers used on x86-64 systems
Joe Millenbach4454d322012-09-02 17:38:20 -0700857 which don't have a hardware IOMMU. Using this PCI devices
858 which can only access 32-bits of memory can be used on systems
859 with more than 3 GB of memory.
860 If unsure, say Y.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100861
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700862config IOMMU_HELPER
Jan Beulich3120e252012-09-10 12:41:45 +0100863 def_bool y
864 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
Linus Torvaldsd25e26b2008-08-25 14:15:38 -0700865
Mike Travis1184dc22008-05-12 21:21:12 +0200866config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200867 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700868 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800869 select CPUMASK_OFFSTACK
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100870 ---help---
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200871 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200872 If unsure, say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100873
874config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800875 int "Maximum number of CPUs" if SMP && !MAXSMP
Michael K. Johnson2a3313f2009-04-21 21:44:48 -0400876 range 2 8 if SMP && X86_32 && !X86_BIGSMP
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500877 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500878 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
Mike Travis78637a972008-12-16 17:34:00 -0800879 default "1" if !SMP
Josh Boyerb53b5ed2013-11-05 09:38:16 -0500880 default "8192" if MAXSMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800881 default "32" if SMP && X86_BIGSMP
Kirill A. Shutemovc5c19942015-05-08 13:25:45 +0300882 default "8" if SMP && X86_32
883 default "64" if SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100884 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100885 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500886 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300887 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100888 minimum value which makes sense is 2.
889
890 This is purely to save memory - each supported CPU adds
891 approximately eight kilobytes to the kernel image.
892
893config SCHED_SMT
894 bool "SMT (Hyperthreading) scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200895 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100896 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100897 SMT scheduler support improves the CPU scheduler's decision making
898 when dealing with Intel Pentium 4 chips with HyperThreading at a
899 cost of slightly increased overhead in some places. If unsure say
900 N here.
901
902config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100903 def_bool y
904 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +0200905 depends on SMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100906 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100907 Multi-core scheduler support improves the CPU scheduler's decision
908 making when dealing with multi-core CPU chips at a cost of slightly
909 increased overhead in some places. If unsure say N here.
910
911source "kernel/Kconfig.preempt"
912
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000913config UP_LATE_INIT
914 def_bool y
Thomas Gleixnerba360f8872015-01-24 10:34:46 +0100915 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +0000916
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100917config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +0000918 bool "Local APIC support on uniprocessors" if !PCI_MSI
919 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +0000920 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100921 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100922 A local APIC (Advanced Programmable Interrupt Controller) is an
923 integrated interrupt controller in the CPU. If you have a single-CPU
924 system which has a processor with a local APIC, you can say Y here to
925 enable and use it. If you say Y here even though your machine doesn't
926 have a local APIC, then the kernel will still run with no slowdown at
927 all. The local APIC supports CPU-generated self-interrupts (timer,
928 performance counters), and the NMI watchdog which detects hard
929 lockups.
930
931config X86_UP_IOAPIC
932 bool "IO-APIC support on uniprocessors"
933 depends on X86_UP_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100934 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100935 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
936 SMP-capable replacement for PC-style interrupt controllers. Most
937 SMP systems and many recent uniprocessor systems have one.
938
939 If you have a single-CPU system with an IO-APIC, you can say Y here
940 to use it. If you say Y here even though your machine doesn't have
941 an IO-APIC, then the kernel will still run with no slowdown at all.
942
943config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100944 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +0200945 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +0800946 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +0800947 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100948
949config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +0000950 def_bool y
951 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100952
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200953config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
954 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200955 depends on X86_IO_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100956 ---help---
Stefan Assmann41b9eb22008-07-15 13:48:55 +0200957 This option enables a workaround that fixes a source of
958 spurious interrupts. This is recommended when threaded
959 interrupt handling is used on systems where the generation of
960 superfluous "boot interrupts" cannot be disabled.
961
962 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
963 entry in the chipset's IO-APIC is masked (as, e.g. the RT
964 kernel does during interrupt handling). On chipsets where this
965 boot IRQ generation cannot be disabled, this workaround keeps
966 the original IRQ line masked so that only the equivalent "boot
967 IRQ" is delivered to the CPUs. The workaround also tells the
968 kernel to set up the IRQ handler on the boot IRQ line. In this
969 way only one interrupt is delivered to the kernel. Otherwise
970 the spurious second interrupt may cause the kernel to bring
971 down (vital) interrupt lines.
972
973 Only affects "broken" chipsets. Interrupt sharing may be
974 increased on these systems.
975
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100976config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +0200977 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +0200978 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +0200979 default y
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100980 ---help---
Andi Kleenbab9bc62009-07-09 00:31:38 +0200981 Machine Check support allows the processor to notify the
982 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100983 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +0200984 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +0200985
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100986config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100987 def_bool y
988 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +0200989 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100990 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100991 Additional support for intel specific MCE features such as
992 the thermal monitor.
993
994config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100995 def_bool y
996 prompt "AMD MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +0200997 depends on X86_MCE && X86_LOCAL_APIC
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100998 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +0100999 Additional support for AMD specific MCE features such as
1000 the DRAM Error Threshold.
1001
Andi Kleen4efc0672009-04-28 19:07:31 +02001002config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001003 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001004 depends on X86_32 && X86_MCE
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001005 ---help---
1006 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001007 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001008 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001009
Andi Kleenb2762682009-02-12 13:49:31 +01001010config X86_MCE_THRESHOLD
1011 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001012 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001013
Andi Kleenea149b32009-04-29 19:31:00 +02001014config X86_MCE_INJECT
Andi Kleenc1ebf832009-07-09 00:31:41 +02001015 depends on X86_MCE
Andi Kleenea149b32009-04-29 19:31:00 +02001016 tristate "Machine check injector support"
1017 ---help---
1018 Provide support for injecting machine checks for testing purposes.
1019 If you don't know what a machine check is and you don't do kernel
1020 QA it is safe to say n.
1021
Andi Kleen4efc0672009-04-28 19:07:31 +02001022config X86_THERMAL_VECTOR
1023 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001024 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001025
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001026config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001027 bool "Legacy VM86 support"
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001028 default n
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001029 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001030 ---help---
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001031 This option allows user programs to put the CPU into V8086
1032 mode, which is an 80286-era approximation of 16-bit real mode.
1033
1034 Some very old versions of X and/or vbetool require this option
1035 for user mode setting. Similarly, DOSEMU will use it if
1036 available to accelerate real mode DOS programs. However, any
1037 recent version of DOSEMU, X, or vbetool should be fully
1038 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001039 fall back to software emulation. Nevertheless, if you are using
1040 a 16-bit DOS program where 16-bit performance matters, vm86
1041 mode might be faster than emulation and you might want to
1042 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001043
Ingo Molnar1e642812015-09-05 08:58:10 +02001044 Note that any app that works on a 64-bit kernel is unlikely to
1045 need this option, as 64-bit kernels don't, and can't, support
1046 V8086 mode. This option is also unrelated to 16-bit protected
1047 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001048
Ingo Molnar1e642812015-09-05 08:58:10 +02001049 Enabling this option increases the complexity of the kernel
1050 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001051
Ingo Molnar1e642812015-09-05 08:58:10 +02001052 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001053
1054config VM86
1055 bool
1056 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001057
1058config X86_16BIT
1059 bool "Enable support for 16-bit segments" if EXPERT
1060 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001061 depends on MODIFY_LDT_SYSCALL
H. Peter Anvin34273f42014-05-04 10:36:22 -07001062 ---help---
1063 This option is required by programs like Wine to run 16-bit
1064 protected mode legacy code on x86 processors. Disabling
1065 this option saves about 300 bytes on i386, or around 6K text
1066 plus 16K runtime memory on x86-64,
1067
1068config X86_ESPFIX32
1069 def_bool y
1070 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001071
H. Peter Anvin197725d2014-05-04 10:00:49 -07001072config X86_ESPFIX64
1073 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001074 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001075
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001076config X86_VSYSCALL_EMULATION
1077 bool "Enable vsyscall emulation" if EXPERT
1078 default y
1079 depends on X86_64
1080 ---help---
1081 This enables emulation of the legacy vsyscall page. Disabling
1082 it is roughly equivalent to booting with vsyscall=none, except
1083 that it will also disable the helpful warning if a program
1084 tries to use a vsyscall. With this option set to N, offending
1085 programs will just segfault, citing addresses of the form
1086 0xffffffffff600?00.
1087
1088 This option is required by many programs built before 2013, and
1089 care should be used even with newer programs if set to N.
1090
1091 Disabling this option saves about 7K of kernel size and
1092 possibly 4K of additional runtime pagetable memory.
1093
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001094config TOSHIBA
1095 tristate "Toshiba Laptop support"
1096 depends on X86_32
1097 ---help---
1098 This adds a driver to safely access the System Management Mode of
1099 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1100 not work on models with a Phoenix BIOS. The System Management Mode
1101 is used to set the BIOS and power saving options on Toshiba portables.
1102
1103 For information on utilities to make use of this driver see the
1104 Toshiba Linux utilities web site at:
1105 <http://www.buzzard.org.uk/toshiba/>.
1106
1107 Say Y if you intend to run this kernel on a Toshiba portable.
1108 Say N otherwise.
1109
1110config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001111 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001112 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001113 select SENSORS_DELL_SMM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001114 ---help---
Pali Rohár039ae582015-05-14 13:16:37 +02001115 This option enables legacy /proc/i8k userspace interface in hwmon
1116 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1117 temperature and allows controlling fan speeds of Dell laptops via
1118 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1119 it reports also power and hotkey status. For fan speed control is
1120 needed userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001121
Pali Rohár039ae582015-05-14 13:16:37 +02001122 Say Y if you intend to run this kernel on old Dell laptops or want to
1123 use userspace package i8kutils.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001124 Say N otherwise.
1125
1126config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001127 bool "Enable X86 board specific fixups for reboot"
1128 depends on X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001129 ---help---
1130 This enables chipset and/or board specific fixups to be done
1131 in order to get reboot to work correctly. This is only needed on
1132 some combinations of hardware and BIOS. The symptom, for which
1133 this config is intended, is when reboot ends with a stalled/hung
1134 system.
1135
1136 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001137 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001138
1139 Say Y if you want to enable the fixup. Currently, it's safe to
1140 enable this option even if you don't need it.
1141 Say N otherwise.
1142
1143config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001144 bool "CPU microcode loading support"
1145 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001146 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Borislav Petkovfe055892015-10-20 11:54:45 +02001147 depends on BLK_DEV_INITRD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001148 select FW_LOADER
1149 ---help---
Borislav Petkove43f6e62012-08-01 19:17:01 +02001150
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001151 If you say Y here, you will be able to update the microcode on
Peter Oruba80cc9f12008-07-28 18:44:22 +02001152 certain Intel and AMD processors. The Intel support is for the
Borislav Petkove43f6e62012-08-01 19:17:01 +02001153 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1154 Xeon etc. The AMD support is for families 0x10 and later. You will
1155 obviously need the actual microcode binary data itself which is not
1156 shipped with the Linux kernel.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001157
Peter Oruba8d86f392008-07-28 18:44:21 +02001158 This option selects the general module only, you need to select
1159 at least one vendor specific module as well.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001160
Borislav Petkove43f6e62012-08-01 19:17:01 +02001161 To compile this driver as a module, choose M here: the module
1162 will be called microcode.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001163
Peter Oruba8d86f392008-07-28 18:44:21 +02001164config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001165 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001166 depends on MICROCODE
1167 default MICROCODE
1168 select FW_LOADER
1169 ---help---
1170 This options enables microcode patch loading support for Intel
1171 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001172
Alanb8989db2014-01-20 18:01:56 +00001173 For the current Intel microcode data package go to
1174 <https://downloadcenter.intel.com> and search for
1175 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001176
Peter Oruba80cc9f12008-07-28 18:44:22 +02001177config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001178 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001179 depends on MICROCODE
1180 select FW_LOADER
1181 ---help---
1182 If you select this option, microcode patch loading support for AMD
1183 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001184
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001185config MICROCODE_OLD_INTERFACE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001186 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001187 depends on MICROCODE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001188
1189config X86_MSR
1190 tristate "/dev/cpu/*/msr - Model-specific register support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001191 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001192 This device gives privileged processes access to the x86
1193 Model-Specific Registers (MSRs). It is a character device with
1194 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1195 MSR accesses are directed to a specific CPU on multi-processor
1196 systems.
1197
1198config X86_CPUID
1199 tristate "/dev/cpu/*/cpuid - CPU information support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001200 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001201 This device gives processes access to the x86 CPUID instruction to
1202 be executed on a specific processor. It is a character device
1203 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1204 /dev/cpu/31/cpuid.
1205
1206choice
1207 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001208 default HIGHMEM4G
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001209 depends on X86_32
1210
1211config NOHIGHMEM
1212 bool "off"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001213 ---help---
1214 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1215 However, the address space of 32-bit x86 processors is only 4
1216 Gigabytes large. That means that, if you have a large amount of
1217 physical memory, not all of it can be "permanently mapped" by the
1218 kernel. The physical memory that's not permanently mapped is called
1219 "high memory".
1220
1221 If you are compiling a kernel which will never run on a machine with
1222 more than 1 Gigabyte total physical RAM, answer "off" here (default
1223 choice and suitable for most users). This will result in a "3GB/1GB"
1224 split: 3GB are mapped so that each process sees a 3GB virtual memory
1225 space and the remaining part of the 4GB virtual memory space is used
1226 by the kernel to permanently map as much physical memory as
1227 possible.
1228
1229 If the machine has between 1 and 4 Gigabytes physical RAM, then
1230 answer "4GB" here.
1231
1232 If more than 4 Gigabytes is used then answer "64GB" here. This
1233 selection turns Intel PAE (Physical Address Extension) mode on.
1234 PAE implements 3-level paging on IA32 processors. PAE is fully
1235 supported by Linux, PAE mode is implemented on all recent Intel
1236 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1237 then the kernel will not boot on CPUs that don't support PAE!
1238
1239 The actual amount of total physical memory will either be
1240 auto detected or can be forced by using a kernel command line option
1241 such as "mem=256M". (Try "man bootparam" or see the documentation of
1242 your boot loader (lilo or loadlin) about how to pass options to the
1243 kernel at boot time.)
1244
1245 If unsure, say "off".
1246
1247config HIGHMEM4G
1248 bool "4GB"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001249 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001250 Select this if you have a 32-bit processor and between 1 and 4
1251 gigabytes of physical RAM.
1252
1253config HIGHMEM64G
1254 bool "64GB"
H. Peter Anvineb068e72012-11-28 11:50:23 -08001255 depends on !M486
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001256 select X86_PAE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001257 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001258 Select this if you have a 32-bit processor and more than 4
1259 gigabytes of physical RAM.
1260
1261endchoice
1262
1263choice
David Rientjes6a108a12011-01-20 14:44:16 -08001264 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001265 default VMSPLIT_3G
1266 depends on X86_32
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001267 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001268 Select the desired split between kernel and user memory.
1269
1270 If the address range available to the kernel is less than the
1271 physical memory installed, the remaining memory will be available
1272 as "high memory". Accessing high memory is a little more costly
1273 than low memory, as it needs to be mapped into the kernel first.
1274 Note that increasing the kernel address space limits the range
1275 available to user programs, making the address space there
1276 tighter. Selecting anything other than the default 3G/1G split
1277 will also likely make your kernel incompatible with binary-only
1278 kernel modules.
1279
1280 If you are not absolutely sure what you are doing, leave this
1281 option alone!
1282
1283 config VMSPLIT_3G
1284 bool "3G/1G user/kernel split"
1285 config VMSPLIT_3G_OPT
1286 depends on !X86_PAE
1287 bool "3G/1G user/kernel split (for full 1G low memory)"
1288 config VMSPLIT_2G
1289 bool "2G/2G user/kernel split"
1290 config VMSPLIT_2G_OPT
1291 depends on !X86_PAE
1292 bool "2G/2G user/kernel split (for full 2G low memory)"
1293 config VMSPLIT_1G
1294 bool "1G/3G user/kernel split"
1295endchoice
1296
1297config PAGE_OFFSET
1298 hex
1299 default 0xB0000000 if VMSPLIT_3G_OPT
1300 default 0x80000000 if VMSPLIT_2G
1301 default 0x78000000 if VMSPLIT_2G_OPT
1302 default 0x40000000 if VMSPLIT_1G
1303 default 0xC0000000
1304 depends on X86_32
1305
1306config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001307 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001308 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001309
1310config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001311 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001312 depends on X86_32 && !HIGHMEM4G
Christian Melki9d99c712015-10-05 17:31:33 +02001313 select SWIOTLB
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001314 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001315 PAE is required for NX support, and furthermore enables
1316 larger swapspace support for non-overcommit purposes. It
1317 has the cost of more pagetable lookup overhead, and also
1318 consumes more pagetable space per process.
1319
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001320config ARCH_PHYS_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001321 def_bool y
1322 depends on X86_64 || X86_PAE
Jeremy Fitzhardinge600715d2008-09-11 01:31:45 -07001323
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001324config ARCH_DMA_ADDR_T_64BIT
Jan Beulich3120e252012-09-10 12:41:45 +01001325 def_bool y
1326 depends on X86_64 || HIGHMEM64G
FUJITA Tomonori66f2b062010-10-20 15:55:35 -07001327
Ingo Molnar10971ab2015-03-05 08:18:23 +01001328config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001329 def_bool y
1330 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001331 ---help---
Ingo Molnar10971ab2015-03-05 08:18:23 +01001332 Certain kernel features effectively disable kernel
1333 linear 1 GB mappings (even if the CPU otherwise
1334 supports them), so don't confuse the user by printing
1335 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001336
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001337# Common NUMA Features
1338config NUMA
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001339 bool "Numa Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001340 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001341 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1342 default y if X86_BIGSMP
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001343 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001344 Enable NUMA (Non Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001345
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001346 The kernel will try to allocate memory used by a CPU on the
1347 local memory controller of the CPU and add some more
1348 NUMA awareness to the kernel.
1349
Ingo Molnarc280ea52008-11-08 13:29:45 +01001350 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001351 (or later), AMD Opteron, or EM64T NUMA.
1352
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001353 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001354 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001355
1356 Otherwise, you should say N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001357
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001358config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001359 def_bool y
1360 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001361 depends on X86_64 && NUMA && PCI
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001362 ---help---
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001363 Enable AMD NUMA node topology detection. You should say Y here if
1364 you have a multi processor AMD system. This uses an old method to
1365 read the NUMA configuration directly from the builtin Northbridge
1366 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1367 which also takes priority if both are compiled in.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001368
1369config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001370 def_bool y
1371 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001372 depends on X86_64 && NUMA && ACPI && PCI
1373 select ACPI_NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001374 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001375 Enable ACPI SRAT based node topology detection.
1376
Suresh Siddha6ec6e0d2008-03-25 10:14:35 -07001377# Some NUMA nodes have memory ranges that span
1378# other nodes. Even though a pfn is valid and
1379# between a node's start and end pfns, it may not
1380# reside on that node. See memmap_init_zone()
1381# for details.
1382config NODES_SPAN_OTHER_NODES
1383 def_bool y
1384 depends on X86_64_ACPI_NUMA
1385
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001386config NUMA_EMU
1387 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001388 depends on NUMA
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001389 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001390 Enable NUMA emulation. A flat machine will be split
1391 into virtual nodes when booted with "numa=fake=N", where N is the
1392 number of nodes. This is only useful for debugging.
1393
1394config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001395 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001396 range 1 10
1397 default "10" if MAXSMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001398 default "6" if X86_64
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001399 default "3"
1400 depends on NEED_MULTIPLE_NODES
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001401 ---help---
Mike Travis1184dc22008-05-12 21:21:12 +02001402 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001403 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001404
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001405config ARCH_HAVE_MEMORY_PRESENT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001406 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001407 depends on X86_32 && DISCONTIGMEM
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001408
1409config NEED_NODE_MEMMAP_SIZE
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001410 def_bool y
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001411 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001412
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001413config ARCH_FLATMEM_ENABLE
1414 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001415 depends on X86_32 && !NUMA
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001416
1417config ARCH_DISCONTIGMEM_ENABLE
1418 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001419 depends on NUMA && X86_32
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001420
1421config ARCH_DISCONTIGMEM_DEFAULT
1422 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001423 depends on NUMA && X86_32
1424
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001425config ARCH_SPARSEMEM_ENABLE
1426 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001427 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001428 select SPARSEMEM_STATIC if X86_32
1429 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1430
Tejun Heo3b166512011-04-01 11:15:12 +02001431config ARCH_SPARSEMEM_DEFAULT
1432 def_bool y
1433 depends on X86_64
1434
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001435config ARCH_SELECT_MEMORY_MODEL
1436 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001437 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001438
1439config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001440 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001441 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001442 help
1443 This option enables a sysfs memory/probe interface for testing.
1444 See Documentation/memory-hotplug.txt for more information.
1445 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001446
Tejun Heo3b166512011-04-01 11:15:12 +02001447config ARCH_PROC_KCORE_TEXT
1448 def_bool y
1449 depends on X86_64 && PROC_KCORE
1450
Avi Kivitya29815a2010-01-10 16:28:09 +02001451config ILLEGAL_POINTER_VALUE
1452 hex
1453 default 0 if X86_32
1454 default 0xdead000000000000 if X86_64
1455
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001456source "mm/Kconfig"
1457
Dan Williams7a678322015-08-19 00:34:34 -04001458config X86_PMEM_LEGACY_DEVICE
1459 bool
1460
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001461config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001462 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001463 depends on PHYS_ADDR_T_64BIT
1464 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001465 select X86_PMEM_LEGACY_DEVICE
Dan Williams9f53f9f2015-06-09 15:33:45 -04001466 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001467 help
1468 Treat memory marked using the non-standard e820 type of 12 as used
1469 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1470 The kernel will offer these regions to the 'pmem' driver so
1471 they can be used for persistent storage.
1472
1473 Say Y if unsure.
1474
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001475config HIGHPTE
1476 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001477 depends on HIGHMEM
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001478 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001479 The VM uses one page table entry for each page of physical memory.
1480 For systems with a lot of RAM, this can be wasteful of precious
1481 low memory. Setting this option will put user-space page table
1482 entries in high memory.
1483
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001484config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001485 bool "Check for low memory corruption"
1486 ---help---
1487 Periodically check for memory corruption in low memory, which
1488 is suspected to be caused by BIOS. Even when enabled in the
1489 configuration, it is disabled at runtime. Enable it by
1490 setting "memory_corruption_check=1" on the kernel command
1491 line. By default it scans the low 64k of memory every 60
1492 seconds; see the memory_corruption_check_size and
1493 memory_corruption_check_period parameters in
1494 Documentation/kernel-parameters.txt to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001495
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001496 When enabled with the default parameters, this option has
1497 almost no overhead, as it reserves a relatively small amount
1498 of memory and scans it infrequently. It both detects corruption
1499 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001500
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001501 It is, however, intended as a diagnostic tool; if repeatable
1502 BIOS-originated corruption always affects the same memory,
1503 you can use memmap= to prevent the kernel from using that
1504 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001505
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001506config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001507 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001508 depends on X86_CHECK_BIOS_CORRUPTION
1509 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001510 ---help---
1511 Set whether the default state of memory_corruption_check is
1512 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001513
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001514config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001515 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1516 default 64
1517 range 4 640
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001518 ---help---
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001519 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001520
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001521 The first page contains BIOS data structures that the kernel
1522 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001523
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001524 By default we reserve the first 64K of physical RAM, as a
1525 number of BIOSes are known to corrupt that memory range
1526 during events such as suspend/resume or monitor cable
1527 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001528
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001529 You can set this to 4 if you are absolutely sure that you
1530 trust the BIOS to get all its memory reservations and usages
1531 right. If you know your BIOS have problems beyond the
1532 default 64K area, you can set this to 640 to avoid using the
1533 entire low memory range.
1534
1535 If you have doubts about the BIOS (e.g. suspend/resume does
1536 not work or there's kernel crashes after certain hardware
1537 hotplug events) then you might want to enable
1538 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1539 typical corruption patterns.
1540
1541 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001542
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001543config MATH_EMULATION
1544 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001545 depends on MODIFY_LDT_SYSCALL
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001546 prompt "Math emulation" if X86_32
1547 ---help---
1548 Linux can emulate a math coprocessor (used for floating point
1549 operations) if you don't have one. 486DX and Pentium processors have
1550 a math coprocessor built in, 486SX and 386 do not, unless you added
1551 a 487DX or 387, respectively. (The messages during boot time can
1552 give you some hints here ["man dmesg"].) Everyone needs either a
1553 coprocessor or this emulation.
1554
1555 If you don't have a math coprocessor, you need to say Y here; if you
1556 say Y here even though you have a coprocessor, the coprocessor will
1557 be used nevertheless. (This behavior can be changed with the kernel
1558 command line option "no387", which comes handy if your coprocessor
1559 is broken. Try "man bootparam" or see the documentation of your boot
1560 loader (lilo or loadlin) about how to pass options to the kernel at
1561 boot time.) This means that it is a good idea to say Y here if you
1562 intend to use this kernel on different machines.
1563
1564 More information about the internals of the Linux math coprocessor
1565 emulation can be found in <file:arch/x86/math-emu/README>.
1566
1567 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1568 kernel, it won't hurt.
1569
1570config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001571 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001572 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001573 ---help---
1574 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1575 the Memory Type Range Registers (MTRRs) may be used to control
1576 processor access to memory ranges. This is most useful if you have
1577 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1578 allows bus write transfers to be combined into a larger transfer
1579 before bursting over the PCI/AGP bus. This can increase performance
1580 of image write operations 2.5 times or more. Saying Y here creates a
1581 /proc/mtrr file which may be used to manipulate your processor's
1582 MTRRs. Typically the X server should use this.
1583
1584 This code has a reasonably generic interface so that similar
1585 control registers on other processors can be easily supported
1586 as well:
1587
1588 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1589 Registers (ARRs) which provide a similar functionality to MTRRs. For
1590 these, the ARRs are used to emulate the MTRRs.
1591 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1592 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1593 write-combining. All of these processors are supported by this code
1594 and it makes sense to say Y here if you have one of them.
1595
1596 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1597 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1598 can lead to all sorts of problems, so it's good to say Y here.
1599
1600 You can safely say Y even if your machine doesn't have MTRRs, you'll
1601 just add about 9 KB to your kernel.
1602
Randy Dunlap7225e752008-07-26 17:54:22 -07001603 See <file:Documentation/x86/mtrr.txt> for more information.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001604
Yinghai Lu95ffa242008-04-29 03:52:33 -07001605config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001606 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001607 prompt "MTRR cleanup support"
1608 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001609 ---help---
Thomas Gleixneraba37282008-07-15 14:48:48 +02001610 Convert MTRR layout from continuous to discrete, so X drivers can
1611 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001612
Thomas Gleixneraba37282008-07-15 14:48:48 +02001613 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001614 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001615 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001616
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001617 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001618
1619config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001620 int "MTRR cleanup enable value (0-1)"
1621 range 0 1
1622 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001623 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001624 ---help---
Yinghai Luf5098d62008-04-29 20:25:58 -07001625 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001626
Yinghai Lu12031a62008-05-02 02:40:22 -07001627config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1628 int "MTRR cleanup spare reg num (0-7)"
1629 range 0 7
1630 default "1"
1631 depends on MTRR_SANITIZER
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001632 ---help---
Yinghai Lu12031a62008-05-02 02:40:22 -07001633 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001634 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001635
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001636config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001637 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001638 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001639 depends on MTRR
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001640 ---help---
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001641 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001642
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001643 PATs are the modern equivalents of MTRRs and are much more
1644 flexible than MTRRs.
1645
1646 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001647 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001648
1649 If unsure, say Y.
1650
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001651config ARCH_USES_PG_UNCACHED
1652 def_bool y
1653 depends on X86_PAT
1654
H. Peter Anvin628c6242011-07-31 13:59:29 -07001655config ARCH_RANDOM
1656 def_bool y
1657 prompt "x86 architectural random number generator" if EXPERT
1658 ---help---
1659 Enable the x86 architectural RDRAND instruction
1660 (Intel Bull Mountain technology) to generate random numbers.
1661 If supported, this is a high bandwidth, cryptographically
1662 secure hardware random number generator.
1663
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001664config X86_SMAP
1665 def_bool y
1666 prompt "Supervisor Mode Access Prevention" if EXPERT
1667 ---help---
1668 Supervisor Mode Access Prevention (SMAP) is a security
1669 feature in newer Intel processors. There is a small
1670 performance cost if this enabled and turned on; there is
1671 also a small increase in the kernel size if this is enabled.
1672
1673 If unsure, say Y.
1674
Dave Hansen72e9b5f2014-12-12 10:38:36 -08001675config X86_INTEL_MPX
1676 prompt "Intel MPX (Memory Protection Extensions)"
1677 def_bool n
1678 depends on CPU_SUP_INTEL
1679 ---help---
1680 MPX provides hardware features that can be used in
1681 conjunction with compiler-instrumented code to check
1682 memory references. It is designed to detect buffer
1683 overflow or underflow bugs.
1684
1685 This option enables running applications which are
1686 instrumented or otherwise use MPX. It does not use MPX
1687 itself inside the kernel or to protect the kernel
1688 against bad memory references.
1689
1690 Enabling this option will make the kernel larger:
1691 ~8k of kernel text and 36 bytes of data on a 64-bit
1692 defconfig. It adds a long to the 'mm_struct' which
1693 will increase the kernel memory overhead of each
1694 process and adds some branches to paths used during
1695 exec() and munmap().
1696
1697 For details, see Documentation/x86/intel_mpx.txt
1698
1699 If unsure, say N.
1700
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001701config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001702 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001703 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001704 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001705 select EFI_RUNTIME_WRAPPERS
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001706 ---help---
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001707 This enables the kernel to use EFI runtime services that are
1708 available (such as the EFI variable services).
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001709
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001710 This option is only useful on systems that have EFI firmware.
1711 In addition, you should use the latest ELILO loader available
1712 at <http://elilo.sourceforge.net> in order to take advantage
1713 of EFI runtime services. However, even with this option, the
1714 resultant kernel should continue to boot on existing non-EFI
1715 platforms.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001716
Matt Fleming291f3632011-12-12 21:27:52 +00001717config EFI_STUB
1718 bool "EFI stub support"
Matt Flemingb16d8c22014-08-05 00:12:19 +01001719 depends on EFI && !X86_USE_3DNOW
Matt Fleming7b2a5832014-07-11 08:45:25 +01001720 select RELOCATABLE
Matt Fleming291f3632011-12-12 21:27:52 +00001721 ---help---
1722 This kernel feature allows a bzImage to be loaded directly
1723 by EFI firmware without the use of a bootloader.
1724
Roy Franz4172fe22013-09-22 15:45:25 -07001725 See Documentation/efi-stub.txt for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001726
Matt Fleming7d453ee2014-01-10 18:52:06 +00001727config EFI_MIXED
1728 bool "EFI mixed-mode support"
1729 depends on EFI_STUB && X86_64
1730 ---help---
1731 Enabling this feature allows a 64-bit kernel to be booted
1732 on a 32-bit firmware, provided that your CPU supports 64-bit
1733 mode.
1734
1735 Note that it is not possible to boot a mixed-mode enabled
1736 kernel via the EFI boot stub - a bootloader that supports
1737 the EFI handover protocol must be used.
1738
1739 If unsure, say N.
1740
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001741config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001742 def_bool y
1743 prompt "Enable seccomp to safely compute untrusted bytecode"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001744 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001745 This kernel feature is useful for number crunching applications
1746 that may need to compute untrusted bytecode during their
1747 execution. By using pipes or other transports made available to
1748 the process as file descriptors supporting the read/write
1749 syscalls, it's possible to isolate those applications in
1750 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001751 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001752 and the task is only allowed to execute a few safe syscalls
1753 defined by each seccomp mode.
1754
1755 If unsure, say Y. Only embedded should say N here.
1756
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001757source kernel/Kconfig.hz
1758
1759config KEXEC
1760 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001761 select KEXEC_CORE
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001762 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001763 kexec is a system call that implements the ability to shutdown your
1764 current kernel, and to start another kernel. It is like a reboot
1765 but it is independent of the system firmware. And like a reboot
1766 you can start any kernel with it, not just Linux.
1767
1768 The name comes from the similarity to the exec system call.
1769
1770 It is an ongoing process to be certain the hardware in a machine
1771 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001772 initially work for you. As of this writing the exact hardware
1773 interface is strongly in flux, so no good recommendation can be
1774 made.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001775
Vivek Goyal74ca3172014-08-29 15:18:46 -07001776config KEXEC_FILE
1777 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001778 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001779 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001780 depends on X86_64
1781 depends on CRYPTO=y
1782 depends on CRYPTO_SHA256=y
1783 ---help---
1784 This is new version of kexec system call. This system call is
1785 file based and takes file descriptors as system call argument
1786 for kernel and initramfs as opposed to list of segments as
1787 accepted by previous system call.
1788
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001789config KEXEC_VERIFY_SIG
1790 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001791 depends on KEXEC_FILE
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001792 ---help---
1793 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001794 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001795
Borislav Petkovd8eb8942015-03-13 14:04:37 +01001796 In addition to that option, you need to enable signature
1797 verification for the corresponding kernel image type being
1798 loaded in order for this to work.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001799
1800config KEXEC_BZIMAGE_VERIFY_SIG
1801 bool "Enable bzImage signature verification support"
1802 depends on KEXEC_VERIFY_SIG
1803 depends on SIGNED_PE_FILE_VERIFICATION
1804 select SYSTEM_TRUSTED_KEYRING
1805 ---help---
1806 Enable bzImage signature verification support.
1807
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001808config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02001809 bool "kernel crash dumps"
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001810 depends on X86_64 || (X86_32 && HIGHMEM)
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001811 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001812 Generate crash dump after being started by kexec.
1813 This should be normally only set in special crash dump kernels
1814 which are loaded in the main kernel with kexec-tools into
1815 a specially reserved region and then later executed after
1816 a crash by kdump/kexec. The crash dump kernel must be compiled
1817 to a memory address not used by the main kernel or BIOS using
1818 PHYSICAL_START, or it must be built as a relocatable image
1819 (CONFIG_RELOCATABLE=y).
1820 For more details see Documentation/kdump/kdump.txt
1821
Huang Ying3ab83522008-07-25 19:45:07 -07001822config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07001823 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08001824 depends on KEXEC && HIBERNATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001825 ---help---
Huang Ying89081d12008-07-25 19:45:10 -07001826 Jump between original kernel and kexeced kernel and invoke
1827 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07001828
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001829config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08001830 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001831 default "0x1000000"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001832 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001833 This gives the physical address where the kernel is loaded.
1834
1835 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1836 bzImage will decompress itself to above physical address and
1837 run from there. Otherwise, bzImage will run from the address where
1838 it has been loaded by the boot loader and will ignore above physical
1839 address.
1840
1841 In normal kdump cases one does not have to set/change this option
1842 as now bzImage can be compiled as a completely relocatable image
1843 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1844 address. This option is mainly useful for the folks who don't want
1845 to use a bzImage for capturing the crash dump and want to use a
1846 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1847 to be specifically compiled to run from a specific memory area
1848 (normally a reserved region) and this option comes handy.
1849
H. Peter Anvinceefccc2009-05-11 16:12:16 -07001850 So if you are using bzImage for capturing the crash dump,
1851 leave the value here unchanged to 0x1000000 and set
1852 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1853 for capturing the crash dump change this value to start of
1854 the reserved region. In other words, it can be set based on
1855 the "X" value as specified in the "crashkernel=YM@XM"
1856 command line boot parameter passed to the panic-ed
1857 kernel. Please take a look at Documentation/kdump/kdump.txt
1858 for more details about crash dumps.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001859
1860 Usage of bzImage for capturing the crash dump is recommended as
1861 one does not have to build two kernels. Same kernel can be used
1862 as production kernel and capture kernel. Above option should have
1863 gone away after relocatable bzImage support is introduced. But it
1864 is present because there are users out there who continue to use
1865 vmlinux for dump capture. This option should go away down the
1866 line.
1867
1868 Don't change this unless you know what you are doing.
1869
1870config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07001871 bool "Build a relocatable kernel"
1872 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001873 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001874 This builds a kernel image that retains relocation information
1875 so it can be loaded someplace besides the default 1MB.
1876 The relocations tend to make the kernel binary about 10% larger,
1877 but are discarded at runtime.
1878
1879 One use is for the kexec on panic case where the recovery kernel
1880 must live at a different physical address than the primary
1881 kernel.
1882
1883 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1884 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07001885 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001886
Kees Cook8ab38202013-10-10 17:18:14 -07001887config RANDOMIZE_BASE
1888 bool "Randomize the address of the kernel image"
1889 depends on RELOCATABLE
Kees Cook8ab38202013-10-10 17:18:14 -07001890 default n
1891 ---help---
1892 Randomizes the physical and virtual address at which the
1893 kernel image is decompressed, as a security feature that
1894 deters exploit attempts relying on knowledge of the location
1895 of kernel internals.
1896
Kees Cooka653f352013-11-11 14:28:39 -08001897 Entropy is generated using the RDRAND instruction if it is
1898 supported. If RDTSC is supported, it is used as well. If
1899 neither RDRAND nor RDTSC are supported, then randomness is
1900 read from the i8254 timer.
Kees Cook8ab38202013-10-10 17:18:14 -07001901
1902 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
Kees Cooka653f352013-11-11 14:28:39 -08001903 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1904 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1905 minimum of 2MiB, only 10 bits of entropy is theoretically
1906 possible. At best, due to page table layouts, 64-bit can use
1907 9 bits of entropy and 32-bit uses 8 bits.
Kees Cook8ab38202013-10-10 17:18:14 -07001908
Kees Cookda2b6fb2013-12-10 12:27:45 -08001909 If unsure, say N.
1910
Kees Cook8ab38202013-10-10 17:18:14 -07001911config RANDOMIZE_BASE_MAX_OFFSET
Kees Cookda2b6fb2013-12-10 12:27:45 -08001912 hex "Maximum kASLR offset allowed" if EXPERT
Kees Cook8ab38202013-10-10 17:18:14 -07001913 depends on RANDOMIZE_BASE
Kees Cook6145cfe2013-10-10 17:18:18 -07001914 range 0x0 0x20000000 if X86_32
1915 default "0x20000000" if X86_32
1916 range 0x0 0x40000000 if X86_64
1917 default "0x40000000" if X86_64
Kees Cook8ab38202013-10-10 17:18:14 -07001918 ---help---
Kees Cookda2b6fb2013-12-10 12:27:45 -08001919 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1920 memory is used to determine the maximal offset in bytes that will
1921 be applied to the kernel when kernel Address Space Layout
1922 Randomization (kASLR) is active. This must be a multiple of
1923 PHYSICAL_ALIGN.
Kees Cook6145cfe2013-10-10 17:18:18 -07001924
Kees Cookda2b6fb2013-12-10 12:27:45 -08001925 On 32-bit this is limited to 512MiB by page table layouts. The
1926 default is 512MiB.
Kees Cook6145cfe2013-10-10 17:18:18 -07001927
Kees Cookda2b6fb2013-12-10 12:27:45 -08001928 On 64-bit this is limited by how the kernel fixmap page table is
1929 positioned, so this cannot be larger than 1GiB currently. Without
1930 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1931 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1932 modules area will shrink to compensate, up to the current maximum
1933 1GiB to 1GiB split. The default is 1GiB.
1934
1935 If unsure, leave at the default value.
Kees Cook8ab38202013-10-10 17:18:14 -07001936
1937# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07001938config X86_NEED_RELOCS
1939 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07001940 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07001941
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001942config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07001943 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07001944 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07001945 range 0x2000 0x1000000 if X86_32
1946 range 0x200000 0x1000000 if X86_64
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001947 ---help---
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001948 This value puts the alignment restrictions on physical address
1949 where kernel is loaded and run from. Kernel is compiled for an
1950 address which meets above alignment restriction.
1951
1952 If bootloader loads the kernel at a non-aligned address and
1953 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1954 address aligned to above value and run from there.
1955
1956 If bootloader loads the kernel at a non-aligned address and
1957 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1958 load address and decompress itself to the address it has been
1959 compiled for and run from there. The address for which kernel is
1960 compiled already meets above alignment restrictions. Hence the
1961 end result is that kernel runs from a physical address meeting
1962 above alignment restrictions.
1963
Kees Cooka0215062013-07-08 09:15:17 -07001964 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1965 this value must be a multiple of 0x200000.
1966
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001967 Don't change this unless you know what you are doing.
1968
1969config HOTPLUG_CPU
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001970 bool "Support for hot-pluggable CPUs"
Stephen Rothwell40b31362013-05-21 13:49:35 +10001971 depends on SMP
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001972 ---help---
Dimitri Sivanich7c13e6a2008-08-11 10:46:46 -05001973 Say Y here to allow turning CPUs off and on. CPUs can be
1974 controlled through /sys/devices/system/cpu.
1975 ( Note: power management support will enable this option
1976 automatically on SMP systems. )
1977 Say N if you want to disable CPU hotplug.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01001978
Fenghua Yu80aa1df2012-11-13 11:32:39 -08001979config BOOTPARAM_HOTPLUG_CPU0
1980 bool "Set default setting of cpu0_hotpluggable"
1981 default n
Kees Cook2c922cd2013-01-22 13:01:19 -08001982 depends on HOTPLUG_CPU
Fenghua Yu80aa1df2012-11-13 11:32:39 -08001983 ---help---
1984 Set whether default state of cpu0_hotpluggable is on or off.
1985
1986 Say Y here to enable CPU0 hotplug by default. If this switch
1987 is turned on, there is no need to give cpu0_hotplug kernel
1988 parameter and the CPU0 hotplug feature is enabled by default.
1989
1990 Please note: there are two known CPU0 dependencies if you want
1991 to enable the CPU0 hotplug feature either by this switch or by
1992 cpu0_hotplug kernel parameter.
1993
1994 First, resume from hibernate or suspend always starts from CPU0.
1995 So hibernate and suspend are prevented if CPU0 is offline.
1996
1997 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1998 offline if any interrupt can not migrate out of CPU0. There may
1999 be other CPU0 dependencies.
2000
2001 Please make sure the dependencies are under your control before
2002 you enable this feature.
2003
2004 Say N if you don't want to enable CPU0 hotplug feature by default.
2005 You still can enable the CPU0 hotplug feature at boot by kernel
2006 parameter cpu0_hotplug.
2007
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002008config DEBUG_HOTPLUG_CPU0
2009 def_bool n
2010 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002011 depends on HOTPLUG_CPU
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002012 ---help---
2013 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2014 soon as possible and boots up userspace with CPU0 offlined. User
2015 can online CPU0 back after boot time.
2016
2017 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2018 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2019 compilation or giving cpu0_hotplug kernel parameter at boot.
2020
2021 If unsure, say N.
2022
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002023config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002024 def_bool n
2025 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Roland McGrathaf65d642008-01-30 13:30:43 +01002026 depends on X86_32 || IA32_EMULATION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002027 ---help---
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002028 Certain buggy versions of glibc will crash if they are
2029 presented with a 32-bit vDSO that is not mapped at the address
2030 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002031
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002032 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2033 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2034 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2035 the only released version with the bug, but OpenSUSE 9
2036 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002037
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002038 The symptom of the bug is that everything crashes on startup, saying:
2039 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2040
2041 Saying Y here changes the default value of the vdso32 boot
2042 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2043 This works around the glibc bug but hurts performance.
2044
2045 If unsure, say N: if you are compiling your own kernel, you
2046 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002047
Kees Cook3dc33bd2015-08-12 17:55:19 -07002048choice
2049 prompt "vsyscall table for legacy applications"
2050 depends on X86_64
2051 default LEGACY_VSYSCALL_EMULATE
2052 help
2053 Legacy user code that does not know how to find the vDSO expects
2054 to be able to issue three syscalls by calling fixed addresses in
2055 kernel space. Since this location is not randomized with ASLR,
2056 it can be used to assist security vulnerability exploitation.
2057
2058 This setting can be changed at boot time via the kernel command
2059 line parameter vsyscall=[native|emulate|none].
2060
2061 On a system with recent enough glibc (2.14 or newer) and no
2062 static binaries, you can say None without a performance penalty
2063 to improve security.
2064
2065 If unsure, select "Emulate".
2066
2067 config LEGACY_VSYSCALL_NATIVE
2068 bool "Native"
2069 help
2070 Actual executable code is located in the fixed vsyscall
2071 address mapping, implementing time() efficiently. Since
2072 this makes the mapping executable, it can be used during
2073 security vulnerability exploitation (traditionally as
2074 ROP gadgets). This configuration is not recommended.
2075
2076 config LEGACY_VSYSCALL_EMULATE
2077 bool "Emulate"
2078 help
2079 The kernel traps and emulates calls into the fixed
2080 vsyscall address mapping. This makes the mapping
2081 non-executable, but it still contains known contents,
2082 which could be used in certain rare security vulnerability
2083 exploits. This configuration is recommended when userspace
2084 still uses the vsyscall area.
2085
2086 config LEGACY_VSYSCALL_NONE
2087 bool "None"
2088 help
2089 There will be no vsyscall mapping at all. This will
2090 eliminate any risk of ASLR bypass due to the vsyscall
2091 fixed address mapping. Attempts to use the vsyscalls
2092 will be reported to dmesg, so that either old or
2093 malicious userspace programs can be identified.
2094
2095endchoice
2096
Tim Bird516cbf32008-08-12 12:52:36 -07002097config CMDLINE_BOOL
2098 bool "Built-in kernel command line"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002099 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002100 Allow for specifying boot arguments to the kernel at
2101 build time. On some systems (e.g. embedded ones), it is
2102 necessary or convenient to provide some or all of the
2103 kernel boot arguments with the kernel itself (that is,
2104 to not rely on the boot loader to provide them.)
2105
2106 To compile command line arguments into the kernel,
2107 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002108 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002109
2110 Systems with fully functional boot loaders (i.e. non-embedded)
2111 should leave this option set to 'N'.
2112
2113config CMDLINE
2114 string "Built-in kernel command string"
2115 depends on CMDLINE_BOOL
2116 default ""
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002117 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002118 Enter arguments here that should be compiled into the kernel
2119 image and used at boot time. If the boot loader provides a
2120 command line at boot time, it is appended to this string to
2121 form the full kernel command line, when the system boots.
2122
2123 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2124 change this behavior.
2125
2126 In most cases, the command line (whether built-in or provided
2127 by the boot loader) should specify the device for the root
2128 file system.
2129
2130config CMDLINE_OVERRIDE
2131 bool "Built-in command line overrides boot loader arguments"
Tim Bird516cbf32008-08-12 12:52:36 -07002132 depends on CMDLINE_BOOL
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002133 ---help---
Tim Bird516cbf32008-08-12 12:52:36 -07002134 Set this option to 'Y' to have the kernel ignore the boot loader
2135 command line, and use ONLY the built-in command line.
2136
2137 This is used to work around broken boot loaders. This should
2138 be set to 'N' under normal conditions.
2139
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002140config MODIFY_LDT_SYSCALL
2141 bool "Enable the LDT (local descriptor table)" if EXPERT
2142 default y
2143 ---help---
2144 Linux can allow user programs to install a per-process x86
2145 Local Descriptor Table (LDT) using the modify_ldt(2) system
2146 call. This is required to run 16-bit or segmented code such as
2147 DOSEMU or some Wine programs. It is also used by some very old
2148 threading libraries.
2149
2150 Enabling this feature adds a small amount of overhead to
2151 context switches and increases the low-level kernel attack
2152 surface. Disabling it removes the modify_ldt(2) system call.
2153
2154 Saying 'N' here may make sense for embedded or server kernels.
2155
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002156source "kernel/livepatch/Kconfig"
2157
Sam Ravnborg506f1d02007-11-09 21:56:54 +01002158endmenu
2159
2160config ARCH_ENABLE_MEMORY_HOTPLUG
2161 def_bool y
2162 depends on X86_64 || (X86_32 && HIGHMEM)
2163
Gary Hade35551052008-10-31 10:52:03 -07002164config ARCH_ENABLE_MEMORY_HOTREMOVE
2165 def_bool y
2166 depends on MEMORY_HOTPLUG
2167
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002168config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002169 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002170 depends on NUMA
2171
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002172config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2173 def_bool y
2174 depends on X86_64 || X86_PAE
2175
Naoya Horiguchic177c812014-06-04 16:05:35 -07002176config ARCH_ENABLE_HUGEPAGE_MIGRATION
2177 def_bool y
2178 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2179
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002180menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002181
2182config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002183 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002184 depends on X86_64 && HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002185
2186source "kernel/power/Kconfig"
2187
2188source "drivers/acpi/Kconfig"
2189
Feng Tangefafc8b2009-08-14 15:23:29 -04002190source "drivers/sfi/Kconfig"
2191
Andi Kleena6b68072008-01-30 13:32:49 +01002192config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002193 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002194 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002195
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002196menuconfig APM
2197 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002198 depends on X86_32 && PM_SLEEP
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002199 ---help---
2200 APM is a BIOS specification for saving power using several different
2201 techniques. This is mostly useful for battery powered laptops with
2202 APM compliant BIOSes. If you say Y here, the system time will be
2203 reset after a RESUME operation, the /proc/apm device will provide
2204 battery status information, and user-space programs will receive
2205 notification of APM "events" (e.g. battery status change).
2206
2207 If you select "Y" here, you can disable actual use of the APM
2208 BIOS by passing the "apm=off" option to the kernel at boot time.
2209
2210 Note that the APM support is almost completely disabled for
2211 machines with more than one CPU.
2212
2213 In order to use APM, you will need supporting software. For location
Michael Witten2dc98fd2011-07-08 21:11:16 +00002214 and more information, read <file:Documentation/power/apm-acpi.txt>
2215 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002216 <http://www.tldp.org/docs.html#howto>.
2217
2218 This driver does not spin down disk drives (see the hdparm(8)
2219 manpage ("man 8 hdparm") for that), and it doesn't turn off
2220 VESA-compliant "green" monitors.
2221
2222 This driver does not support the TI 4000M TravelMate and the ACER
2223 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2224 desktop machines also don't have compliant BIOSes, and this driver
2225 may cause those machines to panic during the boot phase.
2226
2227 Generally, if you don't have a battery in your machine, there isn't
2228 much point in using this driver and you should say N. If you get
2229 random kernel OOPSes or reboots that don't seem to be related to
2230 anything, try disabling/enabling this option (or disabling/enabling
2231 APM in your BIOS).
2232
2233 Some other things you should try when experiencing seemingly random,
2234 "weird" problems:
2235
2236 1) make sure that you have enough swap space and that it is
2237 enabled.
2238 2) pass the "no-hlt" option to the kernel
2239 3) switch on floating point emulation in the kernel and pass
2240 the "no387" option to the kernel
2241 4) pass the "floppy=nodma" option to the kernel
2242 5) pass the "mem=4M" option to the kernel (thereby disabling
2243 all but the first 4 MB of RAM)
2244 6) make sure that the CPU is not over clocked.
2245 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2246 8) disable the cache from your BIOS settings
2247 9) install a fan for the video card or exchange video RAM
2248 10) install a better fan for the CPU
2249 11) exchange RAM chips
2250 12) exchange the motherboard.
2251
2252 To compile this driver as a module, choose M here: the
2253 module will be called apm.
2254
2255if APM
2256
2257config APM_IGNORE_USER_SUSPEND
2258 bool "Ignore USER SUSPEND"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002259 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002260 This option will ignore USER SUSPEND requests. On machines with a
2261 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2262 series notebooks, it is necessary to say Y because of a BIOS bug.
2263
2264config APM_DO_ENABLE
2265 bool "Enable PM at boot time"
2266 ---help---
2267 Enable APM features at boot time. From page 36 of the APM BIOS
2268 specification: "When disabled, the APM BIOS does not automatically
2269 power manage devices, enter the Standby State, enter the Suspend
2270 State, or take power saving steps in response to CPU Idle calls."
2271 This driver will make CPU Idle calls when Linux is idle (unless this
2272 feature is turned off -- see "Do CPU IDLE calls", below). This
2273 should always save battery power, but more complicated APM features
2274 will be dependent on your BIOS implementation. You may need to turn
2275 this option off if your computer hangs at boot time when using APM
2276 support, or if it beeps continuously instead of suspending. Turn
2277 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2278 T400CDT. This is off by default since most machines do fine without
2279 this feature.
2280
2281config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002282 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002283 bool "Make CPU Idle calls when idle"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002284 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002285 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2286 On some machines, this can activate improved power savings, such as
2287 a slowed CPU clock rate, when the machine is idle. These idle calls
2288 are made after the idle loop has run for some length of time (e.g.,
2289 333 mS). On some machines, this will cause a hang at boot time or
2290 whenever the CPU becomes idle. (On machines with more than one CPU,
2291 this option does nothing.)
2292
2293config APM_DISPLAY_BLANK
2294 bool "Enable console blanking using APM"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002295 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002296 Enable console blanking using the APM. Some laptops can use this to
2297 turn off the LCD backlight when the screen blanker of the Linux
2298 virtual console blanks the screen. Note that this is only used by
2299 the virtual console screen blanker, and won't turn off the backlight
2300 when using the X Window system. This also doesn't have anything to
2301 do with your VESA-compliant power-saving monitor. Further, this
2302 option doesn't work for all laptops -- it might not turn off your
2303 backlight at all, or it might print a lot of errors to the console,
2304 especially if you are using gpm.
2305
2306config APM_ALLOW_INTS
2307 bool "Allow interrupts during APM BIOS calls"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002308 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002309 Normally we disable external interrupts while we are making calls to
2310 the APM BIOS as a measure to lessen the effects of a badly behaving
2311 BIOS implementation. The BIOS should reenable interrupts if it
2312 needs to. Unfortunately, some BIOSes do not -- especially those in
2313 many of the newer IBM Thinkpads. If you experience hangs when you
2314 suspend, try setting this to Y. Otherwise, say N.
2315
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002316endif # APM
2317
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002318source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002319
2320source "drivers/cpuidle/Kconfig"
2321
Andy Henroid27471fd2008-10-09 11:45:22 -07002322source "drivers/idle/Kconfig"
2323
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002324endmenu
2325
2326
2327menu "Bus options (PCI etc.)"
2328
2329config PCI
Ingo Molnar1ac97012008-05-19 14:10:14 +02002330 bool "PCI support"
Adrian Bunk1c858082008-01-30 13:32:32 +01002331 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002332 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002333 Find out whether you have a PCI motherboard. PCI is the name of a
2334 bus system, i.e. the way the CPU talks to the other stuff inside
2335 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2336 VESA. If you have PCI, say Y, otherwise N.
2337
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002338choice
2339 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002340 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002341 default PCI_GOANY
2342 ---help---
2343 On PCI systems, the BIOS can be used to detect the PCI devices and
2344 determine their configuration. However, some old PCI motherboards
2345 have BIOS bugs and may crash if this is done. Also, some embedded
2346 PCI-based systems don't have any BIOS at all. Linux can also try to
2347 detect the PCI hardware directly without using the BIOS.
2348
2349 With this option, you can specify how Linux should detect the
2350 PCI devices. If you choose "BIOS", the BIOS will be used,
2351 if you choose "Direct", the BIOS won't be used, and if you
2352 choose "MMConfig", then PCI Express MMCONFIG will be used.
2353 If you choose "Any", the kernel will try MMCONFIG, then the
2354 direct access method and falls back to the BIOS if that doesn't
2355 work. If unsure, go with the default, which is "Any".
2356
2357config PCI_GOBIOS
2358 bool "BIOS"
2359
2360config PCI_GOMMCONFIG
2361 bool "MMConfig"
2362
2363config PCI_GODIRECT
2364 bool "Direct"
2365
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002366config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002367 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002368 depends on OLPC
2369
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002370config PCI_GOANY
2371 bool "Any"
2372
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002373endchoice
2374
2375config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002376 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002377 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002378
2379# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2380config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002381 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002382 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002383
2384config PCI_MMCONFIG
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002385 def_bool y
Feng Tang5f0db7a2009-08-14 15:37:50 -04002386 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002387
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002388config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002389 def_bool y
2390 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002391
Alex Nixonb5401a92010-03-18 16:31:34 -04002392config PCI_XEN
2393 def_bool y
2394 depends on PCI && XEN
2395 select SWIOTLB_XEN
2396
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002397config PCI_DOMAINS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002398 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002399 depends on PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002400
2401config PCI_MMCONFIG
2402 bool "Support mmconfig PCI config space access"
2403 depends on X86_64 && PCI && ACPI
2404
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002405config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002406 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002407 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002408 help
2409 Read the PCI windows out of the CNB20LE host bridge. This allows
2410 PCI hotplug to work on systems with the CNB20LE chipset which do
2411 not have ACPI.
2412
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002413 There's no public spec for this chipset, and this functionality
2414 is known to be incomplete.
2415
2416 You should say N unless you know you need this.
2417
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002418source "drivers/pci/pcie/Kconfig"
2419
2420source "drivers/pci/Kconfig"
2421
David Rientjes1c00f012011-03-22 16:34:59 -07002422# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002423config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002424 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2425 default y
2426 help
2427 Enables ISA-style DMA support for devices requiring such controllers.
2428 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002429
2430if X86_32
2431
2432config ISA
2433 bool "ISA support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002434 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002435 Find out whether you have ISA slots on your motherboard. ISA is the
2436 name of a bus system, i.e. the way the CPU talks to the other stuff
2437 inside your box. Other bus systems are PCI, EISA, MicroChannel
2438 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2439 newer boards don't support it. If you have ISA, say Y, otherwise N.
2440
2441config EISA
2442 bool "EISA support"
2443 depends on ISA
2444 ---help---
2445 The Extended Industry Standard Architecture (EISA) bus was
2446 developed as an open alternative to the IBM MicroChannel bus.
2447
2448 The EISA bus provided some of the features of the IBM MicroChannel
2449 bus while maintaining backward compatibility with cards made for
2450 the older ISA bus. The EISA bus saw limited use between 1988 and
2451 1995 when it was made obsolete by the PCI bus.
2452
2453 Say Y here if you are building a kernel for an EISA-based machine.
2454
2455 Otherwise, say N.
2456
2457source "drivers/eisa/Kconfig"
2458
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002459config SCx200
2460 tristate "NatSemi SCx200 support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002461 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002462 This provides basic support for National Semiconductor's
2463 (now AMD's) Geode processors. The driver probes for the
2464 PCI-IDs of several on-chip devices, so its a good dependency
2465 for other scx200_* drivers.
2466
2467 If compiled as a module, the driver is named scx200.
2468
2469config SCx200HR_TIMER
2470 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002471 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002472 default y
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002473 ---help---
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002474 This driver provides a clocksource built upon the on-chip
2475 27MHz high-resolution timer. Its also a workaround for
2476 NSC Geode SC-1100's buggy TSC, which loses time when the
2477 processor goes idle (as is done by the scheduler). The
2478 other workaround is idle=poll boot option.
2479
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002480config OLPC
2481 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002482 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002483 select GPIOLIB
Thomas Gleixnerdc3119e72011-02-23 10:08:31 +01002484 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002485 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002486 select IRQ_DOMAIN
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002487 ---help---
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002488 Add support for detecting the unique features of the OLPC
2489 XO hardware.
2490
Daniel Drakea3128582011-06-25 17:34:10 +01002491config OLPC_XO1_PM
2492 bool "OLPC XO-1 Power Management"
Daniel Drake97c4cb72011-06-25 17:34:11 +01002493 depends on OLPC && MFD_CS5535 && PM_SLEEP
Daniel Drakea3128582011-06-25 17:34:10 +01002494 select MFD_CORE
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002495 ---help---
Daniel Drake97c4cb72011-06-25 17:34:11 +01002496 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002497
Daniel Drakecfee9592011-06-25 17:34:17 +01002498config OLPC_XO1_RTC
2499 bool "OLPC XO-1 Real Time Clock"
2500 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2501 ---help---
2502 Add support for the XO-1 real time clock, which can be used as a
2503 programmable wakeup source.
2504
Daniel Drake7feda8e2011-06-25 17:34:12 +01002505config OLPC_XO1_SCI
2506 bool "OLPC XO-1 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002507 depends on OLPC && OLPC_XO1_PM
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002508 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002509 select POWER_SUPPLY
Daniel Drake7feda8e2011-06-25 17:34:12 +01002510 select GPIO_CS5535
2511 select MFD_CORE
2512 ---help---
2513 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002514 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002515 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002516 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002517 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002518 - AC adapter status updates
2519 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002520
Daniel Drakea0f30f52011-06-25 17:34:18 +01002521config OLPC_XO15_SCI
2522 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002523 depends on OLPC && ACPI
2524 select POWER_SUPPLY
Daniel Drakea0f30f52011-06-25 17:34:18 +01002525 ---help---
2526 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2527 - EC-driven system wakeups
2528 - AC adapter status updates
2529 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002530
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002531config ALIX
2532 bool "PCEngines ALIX System Support (LED setup)"
2533 select GPIOLIB
2534 ---help---
2535 This option enables system support for the PCEngines ALIX.
2536 At present this just sets up LEDs for GPIO control on
2537 ALIX2/3/6 boards. However, other system specific setup should
2538 get added here.
2539
2540 Note: You must still enable the drivers for GPIO and LED support
2541 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2542
2543 Note: You have to set alix.force=1 for boards with Award BIOS.
2544
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002545config NET5501
2546 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2547 select GPIOLIB
2548 ---help---
2549 This option enables system support for the Soekris Engineering net5501.
2550
Philip A. Prindeville31970592012-01-14 01:45:39 -07002551config GEOS
2552 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2553 select GPIOLIB
2554 depends on DMI
2555 ---help---
2556 This option enables system support for the Traverse Technologies GEOS.
2557
Vivien Didelot7d029122013-01-04 16:18:14 -05002558config TS5500
2559 bool "Technologic Systems TS-5500 platform support"
2560 depends on MELAN
2561 select CHECK_SIGNATURE
2562 select NEW_LEDS
2563 select LEDS_CLASS
2564 ---help---
2565 This option enables system support for the Technologic Systems TS-5500.
2566
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002567endif # X86_32
2568
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002569config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002570 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002571 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002572
2573source "drivers/pcmcia/Kconfig"
2574
2575source "drivers/pci/hotplug/Kconfig"
2576
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002577config RAPIDIO
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002578 tristate "RapidIO support"
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002579 depends on PCI
2580 default n
2581 help
Alexandre Bouninefdf90ab2013-07-03 15:08:56 -07002582 If enabled this option will include drivers and the core
Alexandre Bounine388b78a2011-03-23 16:43:03 -07002583 infrastructure code to support RapidIO interconnect devices.
2584
2585source "drivers/rapidio/Kconfig"
2586
David Herrmanne3263ab2013-08-02 14:05:22 +02002587config X86_SYSFB
2588 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2589 help
2590 Firmwares often provide initial graphics framebuffers so the BIOS,
2591 bootloader or kernel can show basic video-output during boot for
2592 user-guidance and debugging. Historically, x86 used the VESA BIOS
2593 Extensions and EFI-framebuffers for this, which are mostly limited
2594 to x86.
2595 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2596 framebuffers so the new generic system-framebuffer drivers can be
2597 used on x86. If the framebuffer is not compatible with the generic
2598 modes, it is adverticed as fallback platform framebuffer so legacy
2599 drivers like efifb, vesafb and uvesafb can pick it up.
2600 If this option is not selected, all system framebuffers are always
2601 marked as fallback platform framebuffers as usual.
2602
2603 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2604 not be able to pick up generic system framebuffers if this option
2605 is selected. You are highly encouraged to enable simplefb as
2606 replacement if you select this option. simplefb can correctly deal
2607 with generic system framebuffers. But you should still keep vesafb
2608 and others enabled as fallback if a system framebuffer is
2609 incompatible with simplefb.
2610
2611 If unsure, say Y.
2612
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002613endmenu
2614
2615
2616menu "Executable file formats / Emulations"
2617
2618source "fs/Kconfig.binfmt"
2619
2620config IA32_EMULATION
2621 bool "IA32 Emulation"
2622 depends on X86_64
Randy Dunlapd1603992013-06-18 12:33:40 -07002623 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002624 select COMPAT_BINFMT_ELF
Brian Gerst3bead552015-06-22 07:55:19 -04002625 select ARCH_WANT_OLD_COMPAT_IPC
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002626 ---help---
H. J. Lu5fd92e62012-02-19 10:40:03 -08002627 Include code to run legacy 32-bit programs under a
2628 64-bit kernel. You should likely turn this on, unless you're
2629 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002630
2631config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002632 tristate "IA32 a.out support"
2633 depends on IA32_EMULATION
2634 ---help---
2635 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002636
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002637config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002638 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002639 depends on X86_64
H. J. Lu5fd92e62012-02-19 10:40:03 -08002640 ---help---
2641 Include code to run binaries for the x32 native 32-bit ABI
2642 for 64-bit processors. An x32 process gets access to the
2643 full 64-bit register file and wide data path while leaving
2644 pointers at 32 bits for smaller memory footprint.
2645
2646 You will need a recent binutils (2.22 or later) with
2647 elf32_x86_64 support enabled to compile a kernel with this
2648 option set.
2649
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002650config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002651 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002652 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002653
Jan Beulich3120e252012-09-10 12:41:45 +01002654if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002655config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002656 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002657
2658config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002659 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002660 depends on SYSVIPC
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002661
David Howellsee009e4a02011-03-07 15:06:20 +00002662config KEYS_COMPAT
Jan Beulich3120e252012-09-10 12:41:45 +01002663 def_bool y
2664 depends on KEYS
2665endif
David Howellsee009e4a02011-03-07 15:06:20 +00002666
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002667endmenu
2668
2669
Keith Packarde5beae12008-11-03 18:21:45 +01002670config HAVE_ATOMIC_IOMAP
2671 def_bool y
2672 depends on X86_32
2673
Alessandro Rubini4692d772012-04-04 19:39:58 +02002674config X86_DEV_DMA_OPS
2675 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002676 depends on X86_64 || STA2X11
Alessandro Rubini4692d772012-04-04 19:39:58 +02002677
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002678config X86_DMA_REMAP
2679 bool
Alessandro Rubini83125a32012-04-04 19:40:21 +02002680 depends on STA2X11
Alessandro Rubinif7219a52012-04-04 19:40:10 +02002681
Li, Aubrey93e5ead2014-06-30 14:08:42 +08002682config PMC_ATOM
2683 def_bool y
2684 depends on PCI
2685
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002686source "net/Kconfig"
2687
2688source "drivers/Kconfig"
2689
2690source "drivers/firmware/Kconfig"
2691
2692source "fs/Kconfig"
2693
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002694source "arch/x86/Kconfig.debug"
2695
2696source "security/Kconfig"
2697
2698source "crypto/Kconfig"
2699
Avi Kivityedf88412007-12-16 11:02:48 +02002700source "arch/x86/kvm/Kconfig"
2701
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002702source "lib/Kconfig"