Merge branches 'acpi-ec', 'acpi-video', 'acpi-button' and 'acpi-thermal'
[linux-2.6-block.git] / arch / x86 / Kconfig
CommitLineData
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1# Select 32 or 64 bit
2config 64BIT
6840999b 3 bool "64-bit kernel" if ARCH = "x86"
ffee0de4 4 default ARCH != "i386"
8f9ca475 5 ---help---
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6 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
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10 def_bool y
11 depends on !64BIT
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12
13config X86_64
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14 def_bool y
15 depends on 64BIT
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16
17### Arch settings
8d5fffb9 18config X86
3c2362e6 19 def_bool y
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20 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
91dda51a 25 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
6471b825 26 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
446f24d1 27 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
21266be9 28 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 29 select ARCH_HAS_ELF_RANDOMIZE
72d93104 30 select ARCH_HAS_FAST_MULTIPLIER
957e3fac 31 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 32 select ARCH_HAS_KCOV if X86_64
96601adb 33 select ARCH_HAS_PMEM_API if X86_64
67a3e8fe 34 select ARCH_HAS_MMIO_FLUSH
6471b825 35 select ARCH_HAS_SG_CHAIN
c6d30853 36 select ARCH_HAS_UBSAN_SANITIZE_ALL
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37 select ARCH_HAVE_NMI_SAFE_CMPXCHG
38 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 39 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 40 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 41 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 42 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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43 select ARCH_SUPPORTS_INT128 if X86_64
44 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
45 select ARCH_USE_BUILTIN_BSWAP
46 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
47 select ARCH_USE_QUEUED_RWLOCKS
48 select ARCH_USE_QUEUED_SPINLOCKS
72b252ae 49 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
5aaeb5c0 50 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
da4276b8 51 select ARCH_WANT_FRAME_POINTERS
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52 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
53 select ARCH_WANT_OPTIONAL_GPIOLIB
54 select BUILDTIME_EXTABLE_SORT
55 select CLKEVT_I8253
56 select CLKSRC_I8253 if X86_32
57 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
58 select CLOCKSOURCE_WATCHDOG
59 select CLONE_BACKWARDS if X86_32
60 select COMPAT_OLD_SIGACTION if IA32_EMULATION
61 select DCACHE_WORD_ACCESS
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62 select EDAC_ATOMIC_SCRUB
63 select EDAC_SUPPORT
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64 select GENERIC_CLOCKEVENTS
65 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
66 select GENERIC_CLOCKEVENTS_MIN_ADJUST
67 select GENERIC_CMOS_UPDATE
68 select GENERIC_CPU_AUTOPROBE
5b7c73e0 69 select GENERIC_EARLY_IOREMAP
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70 select GENERIC_FIND_FIRST_BIT
71 select GENERIC_IOMAP
72 select GENERIC_IRQ_PROBE
73 select GENERIC_IRQ_SHOW
74 select GENERIC_PENDING_IRQ if SMP
75 select GENERIC_SMP_IDLE_THREAD
76 select GENERIC_STRNCPY_FROM_USER
77 select GENERIC_STRNLEN_USER
78 select GENERIC_TIME_VSYSCALL
79 select HAVE_ACPI_APEI if ACPI
80 select HAVE_ACPI_APEI_NMI if ACPI
81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
82 select HAVE_AOUT if X86_32
83 select HAVE_ARCH_AUDITSYSCALL
84 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
85 select HAVE_ARCH_JUMP_LABEL
86 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
87 select HAVE_ARCH_KGDB
88 select HAVE_ARCH_KMEMCHECK
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89 select HAVE_ARCH_MMAP_RND_BITS if MMU
90 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
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91 select HAVE_ARCH_SECCOMP_FILTER
92 select HAVE_ARCH_SOFT_DIRTY if X86_64
93 select HAVE_ARCH_TRACEHOOK
94 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
6077776b 95 select HAVE_EBPF_JIT if X86_64
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96 select HAVE_CC_STACKPROTECTOR
97 select HAVE_CMPXCHG_DOUBLE
98 select HAVE_CMPXCHG_LOCAL
99 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 100 select HAVE_COPY_THREAD_TLS
cf4db259 101 select HAVE_C_RECORDMCOUNT
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102 select HAVE_DEBUG_KMEMLEAK
103 select HAVE_DEBUG_STACKOVERFLOW
104 select HAVE_DMA_API_DEBUG
6471b825 105 select HAVE_DMA_CONTIGUOUS
677aa9f7 106 select HAVE_DYNAMIC_FTRACE
06aeaaea 107 select HAVE_DYNAMIC_FTRACE_WITH_REGS
58340a07 108 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 109 select HAVE_EXIT_THREAD
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110 select HAVE_FENTRY if X86_64
111 select HAVE_FTRACE_MCOUNT_RECORD
112 select HAVE_FUNCTION_GRAPH_FP_TEST
113 select HAVE_FUNCTION_GRAPH_TRACER
114 select HAVE_FUNCTION_TRACER
115 select HAVE_GENERIC_DMA_COHERENT if X86_32
116 select HAVE_HW_BREAKPOINT
117 select HAVE_IDE
118 select HAVE_IOREMAP_PROT
119 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
120 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 121 select HAVE_KERNEL_BZIP2
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122 select HAVE_KERNEL_GZIP
123 select HAVE_KERNEL_LZ4
2e9f3bdd 124 select HAVE_KERNEL_LZMA
13510997 125 select HAVE_KERNEL_LZO
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126 select HAVE_KERNEL_XZ
127 select HAVE_KPROBES
128 select HAVE_KPROBES_ON_FTRACE
129 select HAVE_KRETPROBES
130 select HAVE_KVM
131 select HAVE_LIVEPATCH if X86_64
132 select HAVE_MEMBLOCK
133 select HAVE_MEMBLOCK_NODE_MAP
0102752e 134 select HAVE_MIXED_BREAKPOINTS_REGS
42a0bb3f 135 select HAVE_NMI
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136 select HAVE_OPROFILE
137 select HAVE_OPTPROBES
138 select HAVE_PCSPKR_PLATFORM
139 select HAVE_PERF_EVENTS
c01d4323 140 select HAVE_PERF_EVENTS_NMI
c5e63197 141 select HAVE_PERF_REGS
c5ebcedb 142 select HAVE_PERF_USER_STACK_DUMP
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143 select HAVE_REGS_AND_STACK_ACCESS_API
144 select HAVE_SYSCALL_TRACEPOINTS
0c3619ea 145 select HAVE_UID16 if X86_32 || IA32_EMULATION
6471b825 146 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 147 select HAVE_USER_RETURN_NOTIFIER
c0185808 148 select IRQ_FORCED_THREADING
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149 select MODULES_USE_ELF_RELA if X86_64
150 select MODULES_USE_ELF_REL if X86_32
151 select OLD_SIGACTION if X86_32
152 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
153 select PERF_EVENTS
3195ef59 154 select RTC_LIB
6471b825 155 select SPARSE_IRQ
83fe27ea 156 select SRCU
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157 select SYSCTL_EXCEPTION_TRACE
158 select USER_STACKTRACE_SUPPORT
159 select VIRT_TO_BUS
160 select X86_DEV_DMA_OPS if X86_64
161 select X86_FEATURE_NAMES if PROC_FS
d4883d5d 162 select HAVE_STACK_VALIDATION if X86_64
63c17fb8 163 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
66d37570 164 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
7d8330a5 165
ba7e4d13 166config INSTRUCTION_DECODER
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167 def_bool y
168 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 169
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170config OUTPUT_FORMAT
171 string
172 default "elf32-i386" if X86_32
173 default "elf64-x86-64" if X86_64
174
73531905 175config ARCH_DEFCONFIG
b9b39bfb 176 string
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177 default "arch/x86/configs/i386_defconfig" if X86_32
178 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 179
8d5fffb9 180config LOCKDEP_SUPPORT
3c2362e6 181 def_bool y
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182
183config STACKTRACE_SUPPORT
3c2362e6 184 def_bool y
8d5fffb9 185
8d5fffb9 186config MMU
3c2362e6 187 def_bool y
8d5fffb9 188
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189config ARCH_MMAP_RND_BITS_MIN
190 default 28 if 64BIT
191 default 8
192
193config ARCH_MMAP_RND_BITS_MAX
194 default 32 if 64BIT
195 default 16
196
197config ARCH_MMAP_RND_COMPAT_BITS_MIN
198 default 8
199
200config ARCH_MMAP_RND_COMPAT_BITS_MAX
201 default 16
202
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203config SBUS
204 bool
205
3bc4e459 206config NEED_DMA_MAP_STATE
3120e25e 207 def_bool y
a6dfa128 208 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 209
18e98307 210config NEED_SG_DMA_LENGTH
4a14d84e 211 def_bool y
18e98307 212
8d5fffb9 213config GENERIC_ISA_DMA
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214 def_bool y
215 depends on ISA_DMA_API
8d5fffb9 216
8d5fffb9 217config GENERIC_BUG
3c2362e6 218 def_bool y
8d5fffb9 219 depends on BUG
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220 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
221
222config GENERIC_BUG_RELATIVE_POINTERS
223 bool
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224
225config GENERIC_HWEIGHT
3c2362e6 226 def_bool y
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227
228config ARCH_MAY_HAVE_PC_FDC
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229 def_bool y
230 depends on ISA_DMA_API
8d5fffb9 231
1032c0ba 232config RWSEM_XCHGADD_ALGORITHM
3120e25e 233 def_bool y
1032c0ba 234
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235config GENERIC_CALIBRATE_DELAY
236 def_bool y
237
9a0b8415 238config ARCH_HAS_CPU_RELAX
239 def_bool y
240
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241config ARCH_HAS_CACHE_LINE_SIZE
242 def_bool y
243
dd5af90a 244config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 245 def_bool y
b32ef636 246
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247config NEED_PER_CPU_EMBED_FIRST_CHUNK
248 def_bool y
249
250config NEED_PER_CPU_PAGE_FIRST_CHUNK
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251 def_bool y
252
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253config ARCH_HIBERNATION_POSSIBLE
254 def_bool y
801e4062 255
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256config ARCH_SUSPEND_POSSIBLE
257 def_bool y
f4cb5700 258
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259config ARCH_WANT_HUGE_PMD_SHARE
260 def_bool y
261
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262config ARCH_WANT_GENERAL_HUGETLB
263 def_bool y
264
8d5fffb9 265config ZONE_DMA32
e0fd24a3 266 def_bool y if X86_64
8d5fffb9 267
8d5fffb9 268config AUDIT_ARCH
e0fd24a3 269 def_bool y if X86_64
8d5fffb9 270
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271config ARCH_SUPPORTS_OPTIMIZED_INLINING
272 def_bool y
273
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274config ARCH_SUPPORTS_DEBUG_PAGEALLOC
275 def_bool y
276
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277config KASAN_SHADOW_OFFSET
278 hex
279 depends on KASAN
280 default 0xdffffc0000000000
281
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282config HAVE_INTEL_TXT
283 def_bool y
6ea30386 284 depends on INTEL_IOMMU && ACPI
69575d38 285
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286config X86_32_SMP
287 def_bool y
288 depends on X86_32 && SMP
289
290config X86_64_SMP
291 def_bool y
292 depends on X86_64 && SMP
293
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294config X86_32_LAZY_GS
295 def_bool y
60a5317f 296 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 297
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298config ARCH_HWEIGHT_CFLAGS
299 string
300 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
301 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
302
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303config ARCH_SUPPORTS_UPROBES
304 def_bool y
305
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306config FIX_EARLYCON_MEM
307 def_bool y
308
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309config DEBUG_RODATA
310 def_bool y
311
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312config PGTABLE_LEVELS
313 int
314 default 4 if X86_64
315 default 3 if X86_PAE
316 default 2
317
506f1d07 318source "init/Kconfig"
dc52ddc0 319source "kernel/Kconfig.freezer"
8d5fffb9 320
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321menu "Processor type and features"
322
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323config ZONE_DMA
324 bool "DMA memory allocation support" if EXPERT
325 default y
326 help
327 DMA memory allocation support allows devices with less than 32-bit
328 addressing to allocate within the first 16MB of address space.
329 Disable if no such devices will be used.
330
331 If unsure, say Y.
332
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333config SMP
334 bool "Symmetric multi-processing support"
335 ---help---
336 This enables support for systems with more than one CPU. If you have
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337 a system with only one CPU, say N. If you have a system with more
338 than one CPU, say Y.
506f1d07 339
4a474157 340 If you say N here, the kernel will run on uni- and multiprocessor
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SR
341 machines, but will use only one CPU of a multiprocessor machine. If
342 you say Y here, the kernel will run on many, but not all,
4a474157 343 uniprocessor machines. On a uniprocessor machine, the kernel
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SR
344 will run faster if you say N here.
345
346 Note that if you say Y here and choose architecture "586" or
347 "Pentium" under "Processor family", the kernel will not work on 486
348 architectures. Similarly, multiprocessor kernels for the "PPro"
349 architecture may not work on all Pentium based boards.
350
351 People using multiprocessor machines who say Y here should also say
352 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
353 Management" code will be disabled if you say Y here.
354
395cf969 355 See also <file:Documentation/x86/i386/IO-APIC.txt>,
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SR
356 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
357 <http://www.tldp.org/docs.html#howto>.
358
359 If you don't know what to do here, say N.
360
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361config X86_FEATURE_NAMES
362 bool "Processor feature human-readable names" if EMBEDDED
363 default y
364 ---help---
365 This option compiles in a table of x86 feature bits and corresponding
366 names. This is required to support /proc/cpuinfo and a few kernel
367 messages. You can disable this to save space, at the expense of
368 making those few kernel messages show numeric feature bits instead.
369
370 If in doubt, say Y.
371
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BP
372config X86_FAST_FEATURE_TESTS
373 bool "Fast CPU feature tests" if EMBEDDED
374 default y
375 ---help---
376 Some fast-paths in the kernel depend on the capabilities of the CPU.
377 Say Y here for the kernel to patch in the appropriate code at runtime
378 based on the capabilities of the CPU. The infrastructure for patching
379 code at runtime takes up some additional space; space-constrained
380 embedded systems may wish to say N here to produce smaller, slightly
381 slower code.
382
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383config X86_X2APIC
384 bool "Support x2apic"
19e3d60d 385 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
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386 ---help---
387 This enables x2apic support on CPUs that have this feature.
388
389 This allows 32-bit apic IDs (so it can support very large systems),
390 and accesses the local apic via MSRs not via mmio.
391
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392 If you don't know what to do here, say N.
393
6695c85b 394config X86_MPPARSE
6e87f9b7 395 bool "Enable MPS table" if ACPI || SFI
7a527688 396 default y
5ab74722 397 depends on X86_LOCAL_APIC
8f9ca475 398 ---help---
6695c85b
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399 For old smp systems that do not have proper acpi support. Newer systems
400 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 401
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402config X86_BIGSMP
403 bool "Support for big SMP systems with more than 8 CPUs"
404 depends on X86_32 && SMP
8f9ca475 405 ---help---
26f7ef14 406 This option is needed for the systems that have more than 8 CPUs
506f1d07 407
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408config GOLDFISH
409 def_bool y
410 depends on X86_GOLDFISH
411
8425091f 412if X86_32
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413config X86_EXTENDED_PLATFORM
414 bool "Support for extended (non-PC) x86 platforms"
415 default y
8f9ca475 416 ---help---
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417 If you disable this option then the kernel will only support
418 standard PC platforms. (which covers the vast majority of
419 systems out there.)
420
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421 If you enable this option then you'll be able to select support
422 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 423 Goldfish (Android emulator)
8425091f 424 AMD Elan
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425 RDC R-321x SoC
426 SGI 320/540 (Visual Workstation)
83125a3a 427 STA2X11-based (e.g. Northville)
3f4110a4 428 Moorestown MID devices
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429
430 If you have one of these systems, or if you want to build a
431 generic distribution kernel, say Y here - otherwise say N.
8425091f 432endif
06ac8346 433
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RT
434if X86_64
435config X86_EXTENDED_PLATFORM
436 bool "Support for extended (non-PC) x86 platforms"
437 default y
438 ---help---
439 If you disable this option then the kernel will only support
440 standard PC platforms. (which covers the vast majority of
441 systems out there.)
442
443 If you enable this option then you'll be able to select support
444 for the following (non-PC) 64 bit x86 platforms:
44b111b5 445 Numascale NumaChip
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446 ScaleMP vSMP
447 SGI Ultraviolet
448
449 If you have one of these systems, or if you want to build a
450 generic distribution kernel, say Y here - otherwise say N.
451endif
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452# This is an alphabetically sorted list of 64 bit extended platforms
453# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
454config X86_NUMACHIP
455 bool "Numascale NumaChip"
456 depends on X86_64
457 depends on X86_EXTENDED_PLATFORM
458 depends on NUMA
459 depends on SMP
460 depends on X86_X2APIC
f9726bfd 461 depends on PCI_MMCONFIG
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SP
462 ---help---
463 Adds support for Numascale NumaChip large-SMP systems. Needed to
464 enable more than ~168 cores.
465 If you don't have one of these, you should say N here.
506f1d07 466
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467config X86_VSMP
468 bool "ScaleMP vSMP"
6276a074 469 select HYPERVISOR_GUEST
c5c606d9
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470 select PARAVIRT
471 depends on X86_64 && PCI
472 depends on X86_EXTENDED_PLATFORM
ead91d4b 473 depends on SMP
8f9ca475 474 ---help---
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475 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
476 supposed to run on these EM64T-based machines. Only choose this option
477 if you have one of these machines.
5e3a77e9 478
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NP
479config X86_UV
480 bool "SGI Ultraviolet"
481 depends on X86_64
c5c606d9 482 depends on X86_EXTENDED_PLATFORM
54c28d29 483 depends on NUMA
1ecb4ae5 484 depends on EFI
9d6c26e7 485 depends on X86_X2APIC
1222e564 486 depends on PCI
8f9ca475 487 ---help---
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488 This option is needed in order to support SGI Ultraviolet systems.
489 If you don't have one of these, you should say N here.
490
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491# Following is an alphabetically sorted list of 32 bit extended platforms
492# Please maintain the alphabetic order if and when there are additions
506f1d07 493
ddd70cf9
JN
494config X86_GOLDFISH
495 bool "Goldfish (Virtual Platform)"
cb7b8023 496 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
497 ---help---
498 Enable support for the Goldfish virtual platform used primarily
499 for Android development. Unless you are building for the Android
500 Goldfish emulator say N here.
501
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TG
502config X86_INTEL_CE
503 bool "CE4100 TV platform"
504 depends on PCI
505 depends on PCI_GODIRECT
6084a6e2 506 depends on X86_IO_APIC
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507 depends on X86_32
508 depends on X86_EXTENDED_PLATFORM
37bc9f50 509 select X86_REBOOTFIXUPS
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510 select OF
511 select OF_EARLY_FLATTREE
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TG
512 ---help---
513 Select for the Intel CE media processor (CE4100) SOC.
514 This option compiles in support for the CE4100 SOC for settop
515 boxes and media devices.
516
4cb9b00f 517config X86_INTEL_MID
43605ef1 518 bool "Intel MID platform support"
43605ef1 519 depends on X86_EXTENDED_PLATFORM
edc6bc78 520 depends on X86_PLATFORM_DEVICES
1ea7c673 521 depends on PCI
3fda5bb4 522 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 523 depends on X86_IO_APIC
7c9c3a1e 524 select SFI
4cb9b00f 525 select I2C
7c9c3a1e 526 select DW_APB_TIMER
1ea7c673 527 select APB_TIMER
1ea7c673 528 select INTEL_SCU_IPC
15a713df 529 select MFD_INTEL_MSIC
1ea7c673 530 ---help---
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DC
531 Select to build a kernel capable of supporting Intel MID (Mobile
532 Internet Device) platform systems which do not have the PCI legacy
533 interfaces. If you are building for a PC class system say N here.
1ea7c673 534
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DC
535 Intel MID platforms are based on an Intel processor and chipset which
536 consume less power than most of the x86 derivatives.
43605ef1 537
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BD
538config X86_INTEL_QUARK
539 bool "Intel Quark platform support"
540 depends on X86_32
541 depends on X86_EXTENDED_PLATFORM
542 depends on X86_PLATFORM_DEVICES
543 depends on X86_TSC
544 depends on PCI
545 depends on PCI_GOANY
546 depends on X86_IO_APIC
547 select IOSF_MBI
548 select INTEL_IMR
9ab6eb51 549 select COMMON_CLK
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BD
550 ---help---
551 Select to include support for Quark X1000 SoC.
552 Say Y here if you have a Quark based system such as the Arduino
553 compatible Intel Galileo.
554
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MW
555config X86_INTEL_LPSS
556 bool "Intel Low Power Subsystem Support"
eebb3e8d 557 depends on X86 && ACPI
3d48aab1 558 select COMMON_CLK
0f531431 559 select PINCTRL
eebb3e8d 560 select IOSF_MBI
3d48aab1
MW
561 ---help---
562 Select to build support for Intel Low Power Subsystem such as
563 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
564 things like clock tree (common clock framework) and pincontrol
565 which are needed by the LPSS peripheral drivers.
3d48aab1 566
92082a88
KX
567config X86_AMD_PLATFORM_DEVICE
568 bool "AMD ACPI2Platform devices support"
569 depends on ACPI
570 select COMMON_CLK
571 select PINCTRL
572 ---help---
573 Select to interpret AMD specific ACPI device to platform device
574 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
575 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
576 implemented under PINCTRL subsystem.
577
ced3ce76
DB
578config IOSF_MBI
579 tristate "Intel SoC IOSF Sideband support for SoC platforms"
580 depends on PCI
581 ---help---
582 This option enables sideband register access support for Intel SoC
583 platforms. On these platforms the IOSF sideband is used in lieu of
584 MSR's for some register accesses, mostly but not limited to thermal
585 and power. Drivers may query the availability of this device to
586 determine if they need the sideband in order to work on these
587 platforms. The sideband is available on the following SoC products.
588 This list is not meant to be exclusive.
589 - BayTrail
590 - Braswell
591 - Quark
592
593 You should say Y if you are running a kernel on one of these SoC's.
594
ed2226bd
DB
595config IOSF_MBI_DEBUG
596 bool "Enable IOSF sideband access through debugfs"
597 depends on IOSF_MBI && DEBUG_FS
598 ---help---
599 Select this option to expose the IOSF sideband access registers (MCR,
600 MDR, MCRX) through debugfs to write and read register information from
601 different units on the SoC. This is most useful for obtaining device
602 state information for debug and analysis. As this is a general access
603 mechanism, users of this option would have specific knowledge of the
604 device they want to access.
605
606 If you don't require the option or are in doubt, say N.
607
c5c606d9
RT
608config X86_RDC321X
609 bool "RDC R-321x SoC"
506f1d07 610 depends on X86_32
c5c606d9
RT
611 depends on X86_EXTENDED_PLATFORM
612 select M486
613 select X86_REBOOTFIXUPS
614 ---help---
615 This option is needed for RDC R-321x system-on-chip, also known
616 as R-8610-(G).
617 If you don't have one of these chips, you should say N here.
618
e0c7ae37 619config X86_32_NON_STANDARD
9c398017
IM
620 bool "Support non-standard 32-bit SMP architectures"
621 depends on X86_32 && SMP
c5c606d9 622 depends on X86_EXTENDED_PLATFORM
8f9ca475 623 ---help---
b5660ba7
PA
624 This option compiles in the bigsmp and STA2X11 default
625 subarchitectures. It is intended for a generic binary
626 kernel. If you select them all, kernel will probe it one by
627 one and will fallback to default.
d49c4288 628
c5c606d9 629# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 630
d949f36f 631config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 632 def_bool y
d949f36f
LT
633 # MCE code calls memory_failure():
634 depends on X86_MCE
635 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
636 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
637 depends on X86_64 || !SPARSEMEM
638 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 639
83125a3a
AR
640config STA2X11
641 bool "STA2X11 Companion Chip Support"
642 depends on X86_32_NON_STANDARD && PCI
643 select X86_DEV_DMA_OPS
644 select X86_DMA_REMAP
645 select SWIOTLB
646 select MFD_STA2X11
647 select ARCH_REQUIRE_GPIOLIB
648 default n
649 ---help---
650 This adds support for boards based on the STA2X11 IO-Hub,
651 a.k.a. "ConneXt". The chip is used in place of the standard
652 PC chipset, so all "standard" peripherals are missing. If this
653 option is selected the kernel will still be able to boot on
654 standard PC machines.
655
82148d1d
S
656config X86_32_IRIS
657 tristate "Eurobraille/Iris poweroff module"
658 depends on X86_32
659 ---help---
660 The Iris machines from EuroBraille do not have APM or ACPI support
661 to shut themselves down properly. A special I/O sequence is
662 needed to do so, which is what this module does at
663 kernel shutdown.
664
665 This is only for Iris machines from EuroBraille.
666
667 If unused, say N.
668
ae1e9130 669config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
670 def_bool y
671 prompt "Single-depth WCHAN output"
a87d0914 672 depends on X86
8f9ca475 673 ---help---
506f1d07
SR
674 Calculate simpler /proc/<PID>/wchan values. If this option
675 is disabled then wchan values will recurse back to the
676 caller function. This provides more accurate wchan values,
677 at the expense of slightly more scheduling overhead.
678
679 If in doubt, say "Y".
680
6276a074
BP
681menuconfig HYPERVISOR_GUEST
682 bool "Linux guest support"
8f9ca475 683 ---help---
6276a074
BP
684 Say Y here to enable options for running Linux under various hyper-
685 visors. This option enables basic hypervisor detection and platform
686 setup.
506f1d07 687
6276a074
BP
688 If you say N, all options in this submenu will be skipped and
689 disabled, and Linux guest support won't be built in.
506f1d07 690
6276a074 691if HYPERVISOR_GUEST
506f1d07 692
e61bd94a
EPH
693config PARAVIRT
694 bool "Enable paravirtualization code"
8f9ca475 695 ---help---
e61bd94a
EPH
696 This changes the kernel so it can modify itself when it is run
697 under a hypervisor, potentially improving performance significantly
698 over full virtualization. However, when run without a hypervisor
699 the kernel is theoretically slower and slightly larger.
700
6276a074
BP
701config PARAVIRT_DEBUG
702 bool "paravirt-ops debugging"
703 depends on PARAVIRT && DEBUG_KERNEL
704 ---help---
705 Enable to debug paravirt_ops internals. Specifically, BUG if
706 a paravirt_op is missing when it is called.
707
b4ecc126
JF
708config PARAVIRT_SPINLOCKS
709 bool "Paravirtualization layer for spinlocks"
6ea30386 710 depends on PARAVIRT && SMP
62c7a1e9 711 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
b4ecc126
JF
712 ---help---
713 Paravirtualized spinlocks allow a pvops backend to replace the
714 spinlock implementation with something virtualization-friendly
715 (for example, block the virtual CPU rather than spinning).
716
4c4e4f61
R
717 It has a minimal impact on native kernels and gives a nice performance
718 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 719
4c4e4f61 720 If you are unsure how to answer this question, answer Y.
b4ecc126 721
45e898b7
WL
722config QUEUED_LOCK_STAT
723 bool "Paravirt queued spinlock statistics"
724 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
725 ---help---
726 Enable the collection of statistical data on the slowpath
727 behavior of paravirtualized queued spinlocks and report
728 them on debugfs.
729
6276a074 730source "arch/x86/xen/Kconfig"
7af192c9 731
6276a074
BP
732config KVM_GUEST
733 bool "KVM Guest support (including kvmclock)"
734 depends on PARAVIRT
735 select PARAVIRT_CLOCK
736 default y
8f9ca475 737 ---help---
6276a074
BP
738 This option enables various optimizations for running under the KVM
739 hypervisor. It includes a paravirtualized clock, so that instead
740 of relying on a PIT (or probably other) emulation by the
741 underlying device model, the host provides the guest with
742 timing infrastructure such as time of day, and system time
506f1d07 743
1e20eb85
SV
744config KVM_DEBUG_FS
745 bool "Enable debug information for KVM Guests in debugfs"
746 depends on KVM_GUEST && DEBUG_FS
747 default n
748 ---help---
749 This option enables collection of various statistics for KVM guest.
750 Statistics are displayed in debugfs filesystem. Enabling this option
751 may incur significant overhead.
752
6276a074
BP
753source "arch/x86/lguest/Kconfig"
754
755config PARAVIRT_TIME_ACCOUNTING
756 bool "Paravirtual steal time accounting"
757 depends on PARAVIRT
758 default n
8f9ca475 759 ---help---
6276a074
BP
760 Select this option to enable fine granularity task steal time
761 accounting. Time spent executing other tasks in parallel with
762 the current vCPU is discounted from the vCPU power. To account for
763 that, there can be a small performance impact.
764
765 If in doubt, say N here.
766
767config PARAVIRT_CLOCK
768 bool
97349135 769
6276a074 770endif #HYPERVISOR_GUEST
97349135 771
08677214 772config NO_BOOTMEM
774ea0bc 773 def_bool y
08677214 774
506f1d07
SR
775source "arch/x86/Kconfig.cpu"
776
777config HPET_TIMER
3c2362e6 778 def_bool X86_64
506f1d07 779 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
780 ---help---
781 Use the IA-PC HPET (High Precision Event Timer) to manage
782 time in preference to the PIT and RTC, if a HPET is
783 present.
784 HPET is the next generation timer replacing legacy 8254s.
785 The HPET provides a stable time base on SMP
786 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
787 as it is off-chip. The interface used is documented
788 in the HPET spec, revision 1.
506f1d07 789
8f9ca475
IM
790 You can safely choose Y here. However, HPET will only be
791 activated if the platform and the BIOS support this feature.
792 Otherwise the 8254 will be used for timing services.
506f1d07 793
8f9ca475 794 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
795
796config HPET_EMULATE_RTC
3c2362e6 797 def_bool y
9d8af78b 798 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 799
bb24c471 800config APB_TIMER
933b9463
AC
801 def_bool y if X86_INTEL_MID
802 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 803 select DW_APB_TIMER
a0c3832a 804 depends on X86_INTEL_MID && SFI
bb24c471
JP
805 help
806 APB timer is the replacement for 8254, HPET on X86 MID platforms.
807 The APBT provides a stable time base on SMP
808 systems, unlike the TSC, but it is more expensive to access,
809 as it is off-chip. APB timers are always running regardless of CPU
810 C states, they are used as per CPU clockevent device when possible.
811
6a108a14 812# Mark as expert because too many people got it wrong.
506f1d07 813# The code disables itself when not needed.
7ae9392c
TP
814config DMI
815 default y
cf074402 816 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 817 bool "Enable DMI scanning" if EXPERT
8f9ca475 818 ---help---
7ae9392c
TP
819 Enabled scanning of DMI to identify machine quirks. Say Y
820 here unless you have verified that your setup is not
821 affected by entries in the DMI blacklist. Required by PNP
822 BIOS code.
823
506f1d07 824config GART_IOMMU
38901f1c 825 bool "Old AMD GART IOMMU support"
506f1d07 826 select SWIOTLB
23ac4ae8 827 depends on X86_64 && PCI && AMD_NB
8f9ca475 828 ---help---
ced3c42c
IM
829 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
830 GART based hardware IOMMUs.
831
832 The GART supports full DMA access for devices with 32-bit access
833 limitations, on systems with more than 3 GB. This is usually needed
834 for USB, sound, many IDE/SATA chipsets and some other devices.
835
836 Newer systems typically have a modern AMD IOMMU, supported via
837 the CONFIG_AMD_IOMMU=y config option.
838
839 In normal configurations this driver is only active when needed:
840 there's more than 3 GB of memory and the system contains a
841 32-bit limited device.
842
843 If unsure, say Y.
506f1d07
SR
844
845config CALGARY_IOMMU
846 bool "IBM Calgary IOMMU support"
847 select SWIOTLB
6ea30386 848 depends on X86_64 && PCI
8f9ca475 849 ---help---
506f1d07
SR
850 Support for hardware IOMMUs in IBM's xSeries x366 and x460
851 systems. Needed to run systems with more than 3GB of memory
852 properly with 32-bit PCI devices that do not support DAC
853 (Double Address Cycle). Calgary also supports bus level
854 isolation, where all DMAs pass through the IOMMU. This
855 prevents them from going anywhere except their intended
856 destination. This catches hard-to-find kernel bugs and
857 mis-behaving drivers and devices that do not use the DMA-API
858 properly to set up their DMA buffers. The IOMMU can be
859 turned off at boot time with the iommu=off parameter.
860 Normally the kernel will make the right choice by itself.
861 If unsure, say Y.
862
863config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
864 def_bool y
865 prompt "Should Calgary be enabled by default?"
506f1d07 866 depends on CALGARY_IOMMU
8f9ca475 867 ---help---
506f1d07
SR
868 Should Calgary be enabled by default? if you choose 'y', Calgary
869 will be used (if it exists). If you choose 'n', Calgary will not be
870 used even if it exists. If you choose 'n' and would like to use
871 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
872 If unsure, say Y.
873
874# need this always selected by IOMMU for the VIA workaround
875config SWIOTLB
a1afd01c 876 def_bool y if X86_64
8f9ca475 877 ---help---
506f1d07 878 Support for software bounce buffers used on x86-64 systems
4454d327
JM
879 which don't have a hardware IOMMU. Using this PCI devices
880 which can only access 32-bits of memory can be used on systems
881 with more than 3 GB of memory.
882 If unsure, say Y.
506f1d07 883
a8522509 884config IOMMU_HELPER
3120e25e
JB
885 def_bool y
886 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 887
1184dc2f 888config MAXSMP
ddb0c5a6 889 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 890 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 891 select CPUMASK_OFFSTACK
8f9ca475 892 ---help---
ddb0c5a6 893 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 894 If unsure, say N.
506f1d07
SR
895
896config NR_CPUS
36f5101a 897 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 898 range 2 8 if SMP && X86_32 && !X86_BIGSMP
bb61ccc7 899 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
b53b5eda 900 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 901 default "1" if !SMP
b53b5eda 902 default "8192" if MAXSMP
b5660ba7 903 default "32" if SMP && X86_BIGSMP
c5c19941
KS
904 default "8" if SMP && X86_32
905 default "64" if SMP
8f9ca475 906 ---help---
506f1d07 907 This allows you to specify the maximum number of CPUs which this
bb61ccc7 908 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 909 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
910 minimum value which makes sense is 2.
911
912 This is purely to save memory - each supported CPU adds
913 approximately eight kilobytes to the kernel image.
914
915config SCHED_SMT
916 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 917 depends on SMP
8f9ca475 918 ---help---
506f1d07
SR
919 SMT scheduler support improves the CPU scheduler's decision making
920 when dealing with Intel Pentium 4 chips with HyperThreading at a
921 cost of slightly increased overhead in some places. If unsure say
922 N here.
923
924config SCHED_MC
3c2362e6
HH
925 def_bool y
926 prompt "Multi-core scheduler support"
c8e56d20 927 depends on SMP
8f9ca475 928 ---help---
506f1d07
SR
929 Multi-core scheduler support improves the CPU scheduler's decision
930 making when dealing with multi-core CPU chips at a cost of slightly
931 increased overhead in some places. If unsure say N here.
932
933source "kernel/Kconfig.preempt"
934
30b8b006
TG
935config UP_LATE_INIT
936 def_bool y
ba360f88 937 depends on !SMP && X86_LOCAL_APIC
30b8b006 938
506f1d07 939config X86_UP_APIC
50849eef
JB
940 bool "Local APIC support on uniprocessors" if !PCI_MSI
941 default PCI_MSI
38a1dfda 942 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 943 ---help---
506f1d07
SR
944 A local APIC (Advanced Programmable Interrupt Controller) is an
945 integrated interrupt controller in the CPU. If you have a single-CPU
946 system which has a processor with a local APIC, you can say Y here to
947 enable and use it. If you say Y here even though your machine doesn't
948 have a local APIC, then the kernel will still run with no slowdown at
949 all. The local APIC supports CPU-generated self-interrupts (timer,
950 performance counters), and the NMI watchdog which detects hard
951 lockups.
952
953config X86_UP_IOAPIC
954 bool "IO-APIC support on uniprocessors"
955 depends on X86_UP_APIC
8f9ca475 956 ---help---
506f1d07
SR
957 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
958 SMP-capable replacement for PC-style interrupt controllers. Most
959 SMP systems and many recent uniprocessor systems have one.
960
961 If you have a single-CPU system with an IO-APIC, you can say Y here
962 to use it. If you say Y here even though your machine doesn't have
963 an IO-APIC, then the kernel will still run with no slowdown at all.
964
965config X86_LOCAL_APIC
3c2362e6 966 def_bool y
0dbc6078 967 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 968 select IRQ_DOMAIN_HIERARCHY
52f518a3 969 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
970
971config X86_IO_APIC
b1da1e71
JB
972 def_bool y
973 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 974
41b9eb26
SA
975config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
976 bool "Reroute for broken boot IRQs"
41b9eb26 977 depends on X86_IO_APIC
8f9ca475 978 ---help---
41b9eb26
SA
979 This option enables a workaround that fixes a source of
980 spurious interrupts. This is recommended when threaded
981 interrupt handling is used on systems where the generation of
982 superfluous "boot interrupts" cannot be disabled.
983
984 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
985 entry in the chipset's IO-APIC is masked (as, e.g. the RT
986 kernel does during interrupt handling). On chipsets where this
987 boot IRQ generation cannot be disabled, this workaround keeps
988 the original IRQ line masked so that only the equivalent "boot
989 IRQ" is delivered to the CPUs. The workaround also tells the
990 kernel to set up the IRQ handler on the boot IRQ line. In this
991 way only one interrupt is delivered to the kernel. Otherwise
992 the spurious second interrupt may cause the kernel to bring
993 down (vital) interrupt lines.
994
995 Only affects "broken" chipsets. Interrupt sharing may be
996 increased on these systems.
997
506f1d07 998config X86_MCE
bab9bc65 999 bool "Machine Check / overheating reporting"
648ed940 1000 select GENERIC_ALLOCATOR
e57dbaf7 1001 default y
506f1d07 1002 ---help---
bab9bc65
AK
1003 Machine Check support allows the processor to notify the
1004 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1005 The action the kernel takes depends on the severity of the problem,
bab9bc65 1006 ranging from warning messages to halting the machine.
4efc0670 1007
506f1d07 1008config X86_MCE_INTEL
3c2362e6
HH
1009 def_bool y
1010 prompt "Intel MCE features"
c1ebf835 1011 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1012 ---help---
506f1d07
SR
1013 Additional support for intel specific MCE features such as
1014 the thermal monitor.
1015
1016config X86_MCE_AMD
3c2362e6
HH
1017 def_bool y
1018 prompt "AMD MCE features"
c1ebf835 1019 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1020 ---help---
506f1d07
SR
1021 Additional support for AMD specific MCE features such as
1022 the DRAM Error Threshold.
1023
4efc0670 1024config X86_ANCIENT_MCE
6fc108a0 1025 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1026 depends on X86_32 && X86_MCE
cd13adcc
HS
1027 ---help---
1028 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1029 systems. These typically need to be enabled explicitly on the command
cd13adcc 1030 line.
4efc0670 1031
b2762686
AK
1032config X86_MCE_THRESHOLD
1033 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1034 def_bool y
b2762686 1035
ea149b36 1036config X86_MCE_INJECT
c1ebf835 1037 depends on X86_MCE
ea149b36
AK
1038 tristate "Machine check injector support"
1039 ---help---
1040 Provide support for injecting machine checks for testing purposes.
1041 If you don't know what a machine check is and you don't do kernel
1042 QA it is safe to say n.
1043
4efc0670
AK
1044config X86_THERMAL_VECTOR
1045 def_bool y
5bb38adc 1046 depends on X86_MCE_INTEL
4efc0670 1047
07dc900e 1048source "arch/x86/events/Kconfig"
e633c65a 1049
5aef51c3 1050config X86_LEGACY_VM86
1e642812 1051 bool "Legacy VM86 support"
5aef51c3 1052 default n
506f1d07 1053 depends on X86_32
8f9ca475 1054 ---help---
5aef51c3
AL
1055 This option allows user programs to put the CPU into V8086
1056 mode, which is an 80286-era approximation of 16-bit real mode.
1057
1058 Some very old versions of X and/or vbetool require this option
1059 for user mode setting. Similarly, DOSEMU will use it if
1060 available to accelerate real mode DOS programs. However, any
1061 recent version of DOSEMU, X, or vbetool should be fully
1062 functional even without kernel VM86 support, as they will all
1e642812
IM
1063 fall back to software emulation. Nevertheless, if you are using
1064 a 16-bit DOS program where 16-bit performance matters, vm86
1065 mode might be faster than emulation and you might want to
1066 enable this option.
5aef51c3 1067
1e642812
IM
1068 Note that any app that works on a 64-bit kernel is unlikely to
1069 need this option, as 64-bit kernels don't, and can't, support
1070 V8086 mode. This option is also unrelated to 16-bit protected
1071 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1072
1e642812
IM
1073 Enabling this option increases the complexity of the kernel
1074 and slows down exception handling a tiny bit.
5aef51c3 1075
1e642812 1076 If unsure, say N here.
5aef51c3
AL
1077
1078config VM86
1079 bool
1080 default X86_LEGACY_VM86
34273f41
PA
1081
1082config X86_16BIT
1083 bool "Enable support for 16-bit segments" if EXPERT
1084 default y
a5b9e5a2 1085 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1086 ---help---
1087 This option is required by programs like Wine to run 16-bit
1088 protected mode legacy code on x86 processors. Disabling
1089 this option saves about 300 bytes on i386, or around 6K text
1090 plus 16K runtime memory on x86-64,
1091
1092config X86_ESPFIX32
1093 def_bool y
1094 depends on X86_16BIT && X86_32
506f1d07 1095
197725de
PA
1096config X86_ESPFIX64
1097 def_bool y
34273f41 1098 depends on X86_16BIT && X86_64
506f1d07 1099
1ad83c85
AL
1100config X86_VSYSCALL_EMULATION
1101 bool "Enable vsyscall emulation" if EXPERT
1102 default y
1103 depends on X86_64
1104 ---help---
1105 This enables emulation of the legacy vsyscall page. Disabling
1106 it is roughly equivalent to booting with vsyscall=none, except
1107 that it will also disable the helpful warning if a program
1108 tries to use a vsyscall. With this option set to N, offending
1109 programs will just segfault, citing addresses of the form
1110 0xffffffffff600?00.
1111
1112 This option is required by many programs built before 2013, and
1113 care should be used even with newer programs if set to N.
1114
1115 Disabling this option saves about 7K of kernel size and
1116 possibly 4K of additional runtime pagetable memory.
1117
506f1d07
SR
1118config TOSHIBA
1119 tristate "Toshiba Laptop support"
1120 depends on X86_32
1121 ---help---
1122 This adds a driver to safely access the System Management Mode of
1123 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1124 not work on models with a Phoenix BIOS. The System Management Mode
1125 is used to set the BIOS and power saving options on Toshiba portables.
1126
1127 For information on utilities to make use of this driver see the
1128 Toshiba Linux utilities web site at:
1129 <http://www.buzzard.org.uk/toshiba/>.
1130
1131 Say Y if you intend to run this kernel on a Toshiba portable.
1132 Say N otherwise.
1133
1134config I8K
039ae585 1135 tristate "Dell i8k legacy laptop support"
949a9d70 1136 select HWMON
039ae585 1137 select SENSORS_DELL_SMM
506f1d07 1138 ---help---
039ae585
PR
1139 This option enables legacy /proc/i8k userspace interface in hwmon
1140 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1141 temperature and allows controlling fan speeds of Dell laptops via
1142 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1143 it reports also power and hotkey status. For fan speed control is
1144 needed userspace package i8kutils.
1145
1146 Say Y if you intend to run this kernel on old Dell laptops or want to
1147 use userspace package i8kutils.
506f1d07
SR
1148 Say N otherwise.
1149
1150config X86_REBOOTFIXUPS
9ba16087
JB
1151 bool "Enable X86 board specific fixups for reboot"
1152 depends on X86_32
506f1d07
SR
1153 ---help---
1154 This enables chipset and/or board specific fixups to be done
1155 in order to get reboot to work correctly. This is only needed on
1156 some combinations of hardware and BIOS. The symptom, for which
1157 this config is intended, is when reboot ends with a stalled/hung
1158 system.
1159
1160 Currently, the only fixup is for the Geode machines using
5e3a77e9 1161 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1162
1163 Say Y if you want to enable the fixup. Currently, it's safe to
1164 enable this option even if you don't need it.
1165 Say N otherwise.
1166
1167config MICROCODE
9a2bc335
BP
1168 bool "CPU microcode loading support"
1169 default y
80030e3d 1170 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1171 select FW_LOADER
1172 ---help---
1173 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1174 Intel and AMD processors. The Intel support is for the IA32 family,
1175 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1176 AMD support is for families 0x10 and later. You will obviously need
1177 the actual microcode binary data itself which is not shipped with
1178 the Linux kernel.
1179
1180 The preferred method to load microcode from a detached initrd is described
1181 in Documentation/x86/early-microcode.txt. For that you need to enable
1182 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1183 initrd for microcode blobs.
1184
1185 In addition, you can build-in the microcode into the kernel. For that you
1186 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1187 to the CONFIG_EXTRA_FIRMWARE config option.
506f1d07 1188
8d86f390 1189config MICROCODE_INTEL
e43f6e67 1190 bool "Intel microcode loading support"
8f9ca475
IM
1191 depends on MICROCODE
1192 default MICROCODE
1193 select FW_LOADER
1194 ---help---
1195 This options enables microcode patch loading support for Intel
1196 processors.
1197
b8989db9
A
1198 For the current Intel microcode data package go to
1199 <https://downloadcenter.intel.com> and search for
1200 'Linux Processor Microcode Data File'.
8d86f390 1201
80cc9f10 1202config MICROCODE_AMD
e43f6e67 1203 bool "AMD microcode loading support"
8f9ca475
IM
1204 depends on MICROCODE
1205 select FW_LOADER
1206 ---help---
1207 If you select this option, microcode patch loading support for AMD
1208 processors will be enabled.
80cc9f10 1209
8f9ca475 1210config MICROCODE_OLD_INTERFACE
3c2362e6 1211 def_bool y
506f1d07 1212 depends on MICROCODE
506f1d07
SR
1213
1214config X86_MSR
1215 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1216 ---help---
506f1d07
SR
1217 This device gives privileged processes access to the x86
1218 Model-Specific Registers (MSRs). It is a character device with
1219 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1220 MSR accesses are directed to a specific CPU on multi-processor
1221 systems.
1222
1223config X86_CPUID
1224 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1225 ---help---
506f1d07
SR
1226 This device gives processes access to the x86 CPUID instruction to
1227 be executed on a specific processor. It is a character device
1228 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1229 /dev/cpu/31/cpuid.
1230
1231choice
1232 prompt "High Memory Support"
6fc108a0 1233 default HIGHMEM4G
506f1d07
SR
1234 depends on X86_32
1235
1236config NOHIGHMEM
1237 bool "off"
506f1d07
SR
1238 ---help---
1239 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1240 However, the address space of 32-bit x86 processors is only 4
1241 Gigabytes large. That means that, if you have a large amount of
1242 physical memory, not all of it can be "permanently mapped" by the
1243 kernel. The physical memory that's not permanently mapped is called
1244 "high memory".
1245
1246 If you are compiling a kernel which will never run on a machine with
1247 more than 1 Gigabyte total physical RAM, answer "off" here (default
1248 choice and suitable for most users). This will result in a "3GB/1GB"
1249 split: 3GB are mapped so that each process sees a 3GB virtual memory
1250 space and the remaining part of the 4GB virtual memory space is used
1251 by the kernel to permanently map as much physical memory as
1252 possible.
1253
1254 If the machine has between 1 and 4 Gigabytes physical RAM, then
1255 answer "4GB" here.
1256
1257 If more than 4 Gigabytes is used then answer "64GB" here. This
1258 selection turns Intel PAE (Physical Address Extension) mode on.
1259 PAE implements 3-level paging on IA32 processors. PAE is fully
1260 supported by Linux, PAE mode is implemented on all recent Intel
1261 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1262 then the kernel will not boot on CPUs that don't support PAE!
1263
1264 The actual amount of total physical memory will either be
1265 auto detected or can be forced by using a kernel command line option
1266 such as "mem=256M". (Try "man bootparam" or see the documentation of
1267 your boot loader (lilo or loadlin) about how to pass options to the
1268 kernel at boot time.)
1269
1270 If unsure, say "off".
1271
1272config HIGHMEM4G
1273 bool "4GB"
8f9ca475 1274 ---help---
506f1d07
SR
1275 Select this if you have a 32-bit processor and between 1 and 4
1276 gigabytes of physical RAM.
1277
1278config HIGHMEM64G
1279 bool "64GB"
eb068e78 1280 depends on !M486
506f1d07 1281 select X86_PAE
8f9ca475 1282 ---help---
506f1d07
SR
1283 Select this if you have a 32-bit processor and more than 4
1284 gigabytes of physical RAM.
1285
1286endchoice
1287
1288choice
6a108a14 1289 prompt "Memory split" if EXPERT
506f1d07
SR
1290 default VMSPLIT_3G
1291 depends on X86_32
8f9ca475 1292 ---help---
506f1d07
SR
1293 Select the desired split between kernel and user memory.
1294
1295 If the address range available to the kernel is less than the
1296 physical memory installed, the remaining memory will be available
1297 as "high memory". Accessing high memory is a little more costly
1298 than low memory, as it needs to be mapped into the kernel first.
1299 Note that increasing the kernel address space limits the range
1300 available to user programs, making the address space there
1301 tighter. Selecting anything other than the default 3G/1G split
1302 will also likely make your kernel incompatible with binary-only
1303 kernel modules.
1304
1305 If you are not absolutely sure what you are doing, leave this
1306 option alone!
1307
1308 config VMSPLIT_3G
1309 bool "3G/1G user/kernel split"
1310 config VMSPLIT_3G_OPT
1311 depends on !X86_PAE
1312 bool "3G/1G user/kernel split (for full 1G low memory)"
1313 config VMSPLIT_2G
1314 bool "2G/2G user/kernel split"
1315 config VMSPLIT_2G_OPT
1316 depends on !X86_PAE
1317 bool "2G/2G user/kernel split (for full 2G low memory)"
1318 config VMSPLIT_1G
1319 bool "1G/3G user/kernel split"
1320endchoice
1321
1322config PAGE_OFFSET
1323 hex
1324 default 0xB0000000 if VMSPLIT_3G_OPT
1325 default 0x80000000 if VMSPLIT_2G
1326 default 0x78000000 if VMSPLIT_2G_OPT
1327 default 0x40000000 if VMSPLIT_1G
1328 default 0xC0000000
1329 depends on X86_32
1330
1331config HIGHMEM
3c2362e6 1332 def_bool y
506f1d07 1333 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1334
1335config X86_PAE
9ba16087 1336 bool "PAE (Physical Address Extension) Support"
506f1d07 1337 depends on X86_32 && !HIGHMEM4G
9d99c712 1338 select SWIOTLB
8f9ca475 1339 ---help---
506f1d07
SR
1340 PAE is required for NX support, and furthermore enables
1341 larger swapspace support for non-overcommit purposes. It
1342 has the cost of more pagetable lookup overhead, and also
1343 consumes more pagetable space per process.
1344
600715dc 1345config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1346 def_bool y
1347 depends on X86_64 || X86_PAE
600715dc 1348
66f2b061 1349config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1350 def_bool y
1351 depends on X86_64 || HIGHMEM64G
66f2b061 1352
10971ab2 1353config X86_DIRECT_GBPAGES
e5008abe
LR
1354 def_bool y
1355 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
8f9ca475 1356 ---help---
10971ab2
IM
1357 Certain kernel features effectively disable kernel
1358 linear 1 GB mappings (even if the CPU otherwise
1359 supports them), so don't confuse the user by printing
1360 that we have them enabled.
9e899816 1361
506f1d07
SR
1362# Common NUMA Features
1363config NUMA
fd51b2d7 1364 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1365 depends on SMP
b5660ba7
PA
1366 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1367 default y if X86_BIGSMP
8f9ca475 1368 ---help---
506f1d07 1369 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1370
506f1d07
SR
1371 The kernel will try to allocate memory used by a CPU on the
1372 local memory controller of the CPU and add some more
1373 NUMA awareness to the kernel.
1374
c280ea5e 1375 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1376 (or later), AMD Opteron, or EM64T NUMA.
1377
b5660ba7 1378 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1379 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1380
1381 Otherwise, you should say N.
506f1d07 1382
eec1d4fa 1383config AMD_NUMA
3c2362e6
HH
1384 def_bool y
1385 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1386 depends on X86_64 && NUMA && PCI
8f9ca475 1387 ---help---
eec1d4fa
HR
1388 Enable AMD NUMA node topology detection. You should say Y here if
1389 you have a multi processor AMD system. This uses an old method to
1390 read the NUMA configuration directly from the builtin Northbridge
1391 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1392 which also takes priority if both are compiled in.
506f1d07
SR
1393
1394config X86_64_ACPI_NUMA
3c2362e6
HH
1395 def_bool y
1396 prompt "ACPI NUMA detection"
506f1d07
SR
1397 depends on X86_64 && NUMA && ACPI && PCI
1398 select ACPI_NUMA
8f9ca475 1399 ---help---
506f1d07
SR
1400 Enable ACPI SRAT based node topology detection.
1401
6ec6e0d9
SS
1402# Some NUMA nodes have memory ranges that span
1403# other nodes. Even though a pfn is valid and
1404# between a node's start and end pfns, it may not
1405# reside on that node. See memmap_init_zone()
1406# for details.
1407config NODES_SPAN_OTHER_NODES
1408 def_bool y
1409 depends on X86_64_ACPI_NUMA
1410
506f1d07
SR
1411config NUMA_EMU
1412 bool "NUMA emulation"
1b7e03ef 1413 depends on NUMA
8f9ca475 1414 ---help---
506f1d07
SR
1415 Enable NUMA emulation. A flat machine will be split
1416 into virtual nodes when booted with "numa=fake=N", where N is the
1417 number of nodes. This is only useful for debugging.
1418
1419config NODES_SHIFT
d25e26b6 1420 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1421 range 1 10
1422 default "10" if MAXSMP
506f1d07 1423 default "6" if X86_64
506f1d07
SR
1424 default "3"
1425 depends on NEED_MULTIPLE_NODES
8f9ca475 1426 ---help---
1184dc2f 1427 Specify the maximum number of NUMA Nodes available on the target
692105b8 1428 system. Increases memory reserved to accommodate various tables.
506f1d07 1429
506f1d07 1430config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1431 def_bool y
506f1d07 1432 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1433
1434config NEED_NODE_MEMMAP_SIZE
3c2362e6 1435 def_bool y
506f1d07 1436 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1437
506f1d07
SR
1438config ARCH_FLATMEM_ENABLE
1439 def_bool y
3b16651f 1440 depends on X86_32 && !NUMA
506f1d07
SR
1441
1442config ARCH_DISCONTIGMEM_ENABLE
1443 def_bool y
b263295d 1444 depends on NUMA && X86_32
506f1d07
SR
1445
1446config ARCH_DISCONTIGMEM_DEFAULT
1447 def_bool y
b263295d
CL
1448 depends on NUMA && X86_32
1449
506f1d07
SR
1450config ARCH_SPARSEMEM_ENABLE
1451 def_bool y
6ea30386 1452 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1453 select SPARSEMEM_STATIC if X86_32
1454 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1455
3b16651f
TH
1456config ARCH_SPARSEMEM_DEFAULT
1457 def_bool y
1458 depends on X86_64
1459
506f1d07
SR
1460config ARCH_SELECT_MEMORY_MODEL
1461 def_bool y
b263295d 1462 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1463
1464config ARCH_MEMORY_PROBE
a0842b70 1465 bool "Enable sysfs memory/probe interface"
3120e25e 1466 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1467 help
1468 This option enables a sysfs memory/probe interface for testing.
1469 See Documentation/memory-hotplug.txt for more information.
1470 If you are unsure how to answer this question, answer N.
506f1d07 1471
3b16651f
TH
1472config ARCH_PROC_KCORE_TEXT
1473 def_bool y
1474 depends on X86_64 && PROC_KCORE
1475
a29815a3
AK
1476config ILLEGAL_POINTER_VALUE
1477 hex
1478 default 0 if X86_32
1479 default 0xdead000000000000 if X86_64
1480
506f1d07
SR
1481source "mm/Kconfig"
1482
7a67832c
DW
1483config X86_PMEM_LEGACY_DEVICE
1484 bool
1485
ec776ef6 1486config X86_PMEM_LEGACY
7a67832c 1487 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1488 depends on PHYS_ADDR_T_64BIT
1489 depends on BLK_DEV
7a67832c 1490 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1491 select LIBNVDIMM
ec776ef6
CH
1492 help
1493 Treat memory marked using the non-standard e820 type of 12 as used
1494 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1495 The kernel will offer these regions to the 'pmem' driver so
1496 they can be used for persistent storage.
1497
1498 Say Y if unsure.
1499
506f1d07
SR
1500config HIGHPTE
1501 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1502 depends on HIGHMEM
8f9ca475 1503 ---help---
506f1d07
SR
1504 The VM uses one page table entry for each page of physical memory.
1505 For systems with a lot of RAM, this can be wasteful of precious
1506 low memory. Setting this option will put user-space page table
1507 entries in high memory.
1508
9f077871 1509config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1510 bool "Check for low memory corruption"
1511 ---help---
1512 Periodically check for memory corruption in low memory, which
1513 is suspected to be caused by BIOS. Even when enabled in the
1514 configuration, it is disabled at runtime. Enable it by
1515 setting "memory_corruption_check=1" on the kernel command
1516 line. By default it scans the low 64k of memory every 60
1517 seconds; see the memory_corruption_check_size and
1518 memory_corruption_check_period parameters in
1519 Documentation/kernel-parameters.txt to adjust this.
1520
1521 When enabled with the default parameters, this option has
1522 almost no overhead, as it reserves a relatively small amount
1523 of memory and scans it infrequently. It both detects corruption
1524 and prevents it from affecting the running system.
1525
1526 It is, however, intended as a diagnostic tool; if repeatable
1527 BIOS-originated corruption always affects the same memory,
1528 you can use memmap= to prevent the kernel from using that
1529 memory.
9f077871 1530
c885df50 1531config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1532 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1533 depends on X86_CHECK_BIOS_CORRUPTION
1534 default y
8f9ca475
IM
1535 ---help---
1536 Set whether the default state of memory_corruption_check is
1537 on or off.
c885df50 1538
9ea77bdb 1539config X86_RESERVE_LOW
d0cd7425
PA
1540 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1541 default 64
1542 range 4 640
8f9ca475 1543 ---help---
d0cd7425
PA
1544 Specify the amount of low memory to reserve for the BIOS.
1545
1546 The first page contains BIOS data structures that the kernel
1547 must not use, so that page must always be reserved.
1548
1549 By default we reserve the first 64K of physical RAM, as a
1550 number of BIOSes are known to corrupt that memory range
1551 during events such as suspend/resume or monitor cable
1552 insertion, so it must not be used by the kernel.
fc381519 1553
d0cd7425
PA
1554 You can set this to 4 if you are absolutely sure that you
1555 trust the BIOS to get all its memory reservations and usages
1556 right. If you know your BIOS have problems beyond the
1557 default 64K area, you can set this to 640 to avoid using the
1558 entire low memory range.
fc381519 1559
d0cd7425
PA
1560 If you have doubts about the BIOS (e.g. suspend/resume does
1561 not work or there's kernel crashes after certain hardware
1562 hotplug events) then you might want to enable
1563 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1564 typical corruption patterns.
fc381519 1565
d0cd7425 1566 Leave this to the default value of 64 if you are unsure.
fc381519 1567
506f1d07
SR
1568config MATH_EMULATION
1569 bool
a5b9e5a2 1570 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1571 prompt "Math emulation" if X86_32
1572 ---help---
1573 Linux can emulate a math coprocessor (used for floating point
1574 operations) if you don't have one. 486DX and Pentium processors have
1575 a math coprocessor built in, 486SX and 386 do not, unless you added
1576 a 487DX or 387, respectively. (The messages during boot time can
1577 give you some hints here ["man dmesg"].) Everyone needs either a
1578 coprocessor or this emulation.
1579
1580 If you don't have a math coprocessor, you need to say Y here; if you
1581 say Y here even though you have a coprocessor, the coprocessor will
1582 be used nevertheless. (This behavior can be changed with the kernel
1583 command line option "no387", which comes handy if your coprocessor
1584 is broken. Try "man bootparam" or see the documentation of your boot
1585 loader (lilo or loadlin) about how to pass options to the kernel at
1586 boot time.) This means that it is a good idea to say Y here if you
1587 intend to use this kernel on different machines.
1588
1589 More information about the internals of the Linux math coprocessor
1590 emulation can be found in <file:arch/x86/math-emu/README>.
1591
1592 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1593 kernel, it won't hurt.
1594
1595config MTRR
6fc108a0 1596 def_bool y
6a108a14 1597 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1598 ---help---
1599 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1600 the Memory Type Range Registers (MTRRs) may be used to control
1601 processor access to memory ranges. This is most useful if you have
1602 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1603 allows bus write transfers to be combined into a larger transfer
1604 before bursting over the PCI/AGP bus. This can increase performance
1605 of image write operations 2.5 times or more. Saying Y here creates a
1606 /proc/mtrr file which may be used to manipulate your processor's
1607 MTRRs. Typically the X server should use this.
1608
1609 This code has a reasonably generic interface so that similar
1610 control registers on other processors can be easily supported
1611 as well:
1612
1613 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1614 Registers (ARRs) which provide a similar functionality to MTRRs. For
1615 these, the ARRs are used to emulate the MTRRs.
1616 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1617 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1618 write-combining. All of these processors are supported by this code
1619 and it makes sense to say Y here if you have one of them.
1620
1621 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1622 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1623 can lead to all sorts of problems, so it's good to say Y here.
1624
1625 You can safely say Y even if your machine doesn't have MTRRs, you'll
1626 just add about 9 KB to your kernel.
1627
7225e751 1628 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1629
95ffa243 1630config MTRR_SANITIZER
2ffb3501 1631 def_bool y
95ffa243
YL
1632 prompt "MTRR cleanup support"
1633 depends on MTRR
8f9ca475 1634 ---help---
aba3728c
TG
1635 Convert MTRR layout from continuous to discrete, so X drivers can
1636 add writeback entries.
95ffa243 1637
aba3728c 1638 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1639 The largest mtrr entry size for a continuous block can be set with
aba3728c 1640 mtrr_chunk_size.
95ffa243 1641
2ffb3501 1642 If unsure, say Y.
95ffa243
YL
1643
1644config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1645 int "MTRR cleanup enable value (0-1)"
1646 range 0 1
1647 default "0"
95ffa243 1648 depends on MTRR_SANITIZER
8f9ca475 1649 ---help---
f5098d62 1650 Enable mtrr cleanup default value
95ffa243 1651
12031a62
YL
1652config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1653 int "MTRR cleanup spare reg num (0-7)"
1654 range 0 7
1655 default "1"
1656 depends on MTRR_SANITIZER
8f9ca475 1657 ---help---
12031a62 1658 mtrr cleanup spare entries default, it can be changed via
aba3728c 1659 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1660
2e5d9c85 1661config X86_PAT
6fc108a0 1662 def_bool y
6a108a14 1663 prompt "x86 PAT support" if EXPERT
2a8a2719 1664 depends on MTRR
8f9ca475 1665 ---help---
2e5d9c85 1666 Use PAT attributes to setup page level cache control.
042b78e4 1667
2e5d9c85 1668 PATs are the modern equivalents of MTRRs and are much more
1669 flexible than MTRRs.
1670
1671 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1672 spontaneous reboots) or a non-working video driver.
2e5d9c85 1673
1674 If unsure, say Y.
1675
46cf98cd
VP
1676config ARCH_USES_PG_UNCACHED
1677 def_bool y
1678 depends on X86_PAT
1679
628c6246
PA
1680config ARCH_RANDOM
1681 def_bool y
1682 prompt "x86 architectural random number generator" if EXPERT
1683 ---help---
1684 Enable the x86 architectural RDRAND instruction
1685 (Intel Bull Mountain technology) to generate random numbers.
1686 If supported, this is a high bandwidth, cryptographically
1687 secure hardware random number generator.
1688
51ae4a2d
PA
1689config X86_SMAP
1690 def_bool y
1691 prompt "Supervisor Mode Access Prevention" if EXPERT
1692 ---help---
1693 Supervisor Mode Access Prevention (SMAP) is a security
1694 feature in newer Intel processors. There is a small
1695 performance cost if this enabled and turned on; there is
1696 also a small increase in the kernel size if this is enabled.
1697
1698 If unsure, say Y.
1699
72e9b5fe
DH
1700config X86_INTEL_MPX
1701 prompt "Intel MPX (Memory Protection Extensions)"
1702 def_bool n
1703 depends on CPU_SUP_INTEL
1704 ---help---
1705 MPX provides hardware features that can be used in
1706 conjunction with compiler-instrumented code to check
1707 memory references. It is designed to detect buffer
1708 overflow or underflow bugs.
1709
1710 This option enables running applications which are
1711 instrumented or otherwise use MPX. It does not use MPX
1712 itself inside the kernel or to protect the kernel
1713 against bad memory references.
1714
1715 Enabling this option will make the kernel larger:
1716 ~8k of kernel text and 36 bytes of data on a 64-bit
1717 defconfig. It adds a long to the 'mm_struct' which
1718 will increase the kernel memory overhead of each
1719 process and adds some branches to paths used during
1720 exec() and munmap().
1721
1722 For details, see Documentation/x86/intel_mpx.txt
1723
1724 If unsure, say N.
1725
35e97790 1726config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1727 prompt "Intel Memory Protection Keys"
35e97790 1728 def_bool y
284244a9 1729 # Note: only available in 64-bit mode
35e97790 1730 depends on CPU_SUP_INTEL && X86_64
284244a9
DH
1731 ---help---
1732 Memory Protection Keys provides a mechanism for enforcing
1733 page-based protections, but without requiring modification of the
1734 page tables when an application changes protection domains.
1735
1736 For details, see Documentation/x86/protection-keys.txt
1737
1738 If unsure, say y.
35e97790 1739
506f1d07 1740config EFI
9ba16087 1741 bool "EFI runtime service support"
5b83683f 1742 depends on ACPI
f6ce5002 1743 select UCS2_STRING
022ee6c5 1744 select EFI_RUNTIME_WRAPPERS
506f1d07 1745 ---help---
8f9ca475
IM
1746 This enables the kernel to use EFI runtime services that are
1747 available (such as the EFI variable services).
506f1d07 1748
8f9ca475
IM
1749 This option is only useful on systems that have EFI firmware.
1750 In addition, you should use the latest ELILO loader available
1751 at <http://elilo.sourceforge.net> in order to take advantage
1752 of EFI runtime services. However, even with this option, the
1753 resultant kernel should continue to boot on existing non-EFI
1754 platforms.
506f1d07 1755
291f3632
MF
1756config EFI_STUB
1757 bool "EFI stub support"
b16d8c23 1758 depends on EFI && !X86_USE_3DNOW
7b2a583a 1759 select RELOCATABLE
291f3632
MF
1760 ---help---
1761 This kernel feature allows a bzImage to be loaded directly
1762 by EFI firmware without the use of a bootloader.
1763
4172fe2f 1764 See Documentation/efi-stub.txt for more information.
0c759662 1765
7d453eee
MF
1766config EFI_MIXED
1767 bool "EFI mixed-mode support"
1768 depends on EFI_STUB && X86_64
1769 ---help---
1770 Enabling this feature allows a 64-bit kernel to be booted
1771 on a 32-bit firmware, provided that your CPU supports 64-bit
1772 mode.
1773
1774 Note that it is not possible to boot a mixed-mode enabled
1775 kernel via the EFI boot stub - a bootloader that supports
1776 the EFI handover protocol must be used.
1777
1778 If unsure, say N.
1779
506f1d07 1780config SECCOMP
3c2362e6
HH
1781 def_bool y
1782 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1783 ---help---
506f1d07
SR
1784 This kernel feature is useful for number crunching applications
1785 that may need to compute untrusted bytecode during their
1786 execution. By using pipes or other transports made available to
1787 the process as file descriptors supporting the read/write
1788 syscalls, it's possible to isolate those applications in
1789 their own address space using seccomp. Once seccomp is
9c0bbee8 1790 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1791 and the task is only allowed to execute a few safe syscalls
1792 defined by each seccomp mode.
1793
1794 If unsure, say Y. Only embedded should say N here.
1795
506f1d07
SR
1796source kernel/Kconfig.hz
1797
1798config KEXEC
1799 bool "kexec system call"
2965faa5 1800 select KEXEC_CORE
8f9ca475 1801 ---help---
506f1d07
SR
1802 kexec is a system call that implements the ability to shutdown your
1803 current kernel, and to start another kernel. It is like a reboot
1804 but it is independent of the system firmware. And like a reboot
1805 you can start any kernel with it, not just Linux.
1806
1807 The name comes from the similarity to the exec system call.
1808
1809 It is an ongoing process to be certain the hardware in a machine
1810 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1811 initially work for you. As of this writing the exact hardware
1812 interface is strongly in flux, so no good recommendation can be
1813 made.
506f1d07 1814
74ca317c
VG
1815config KEXEC_FILE
1816 bool "kexec file based system call"
2965faa5 1817 select KEXEC_CORE
74ca317c 1818 select BUILD_BIN2C
74ca317c
VG
1819 depends on X86_64
1820 depends on CRYPTO=y
1821 depends on CRYPTO_SHA256=y
1822 ---help---
1823 This is new version of kexec system call. This system call is
1824 file based and takes file descriptors as system call argument
1825 for kernel and initramfs as opposed to list of segments as
1826 accepted by previous system call.
1827
8e7d8381
VG
1828config KEXEC_VERIFY_SIG
1829 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1830 depends on KEXEC_FILE
8e7d8381
VG
1831 ---help---
1832 This option makes kernel signature verification mandatory for
d8eb8940
BP
1833 the kexec_file_load() syscall.
1834
1835 In addition to that option, you need to enable signature
1836 verification for the corresponding kernel image type being
1837 loaded in order for this to work.
8e7d8381
VG
1838
1839config KEXEC_BZIMAGE_VERIFY_SIG
1840 bool "Enable bzImage signature verification support"
1841 depends on KEXEC_VERIFY_SIG
1842 depends on SIGNED_PE_FILE_VERIFICATION
1843 select SYSTEM_TRUSTED_KEYRING
1844 ---help---
1845 Enable bzImage signature verification support.
1846
506f1d07 1847config CRASH_DUMP
04b69447 1848 bool "kernel crash dumps"
506f1d07 1849 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1850 ---help---
506f1d07
SR
1851 Generate crash dump after being started by kexec.
1852 This should be normally only set in special crash dump kernels
1853 which are loaded in the main kernel with kexec-tools into
1854 a specially reserved region and then later executed after
1855 a crash by kdump/kexec. The crash dump kernel must be compiled
1856 to a memory address not used by the main kernel or BIOS using
1857 PHYSICAL_START, or it must be built as a relocatable image
1858 (CONFIG_RELOCATABLE=y).
1859 For more details see Documentation/kdump/kdump.txt
1860
3ab83521 1861config KEXEC_JUMP
6ea30386 1862 bool "kexec jump"
fee7b0d8 1863 depends on KEXEC && HIBERNATION
8f9ca475 1864 ---help---
89081d17
HY
1865 Jump between original kernel and kexeced kernel and invoke
1866 code in physical address mode via KEXEC
3ab83521 1867
506f1d07 1868config PHYSICAL_START
6a108a14 1869 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 1870 default "0x1000000"
8f9ca475 1871 ---help---
506f1d07
SR
1872 This gives the physical address where the kernel is loaded.
1873
1874 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1875 bzImage will decompress itself to above physical address and
1876 run from there. Otherwise, bzImage will run from the address where
1877 it has been loaded by the boot loader and will ignore above physical
1878 address.
1879
1880 In normal kdump cases one does not have to set/change this option
1881 as now bzImage can be compiled as a completely relocatable image
1882 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1883 address. This option is mainly useful for the folks who don't want
1884 to use a bzImage for capturing the crash dump and want to use a
1885 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1886 to be specifically compiled to run from a specific memory area
1887 (normally a reserved region) and this option comes handy.
1888
ceefccc9
PA
1889 So if you are using bzImage for capturing the crash dump,
1890 leave the value here unchanged to 0x1000000 and set
1891 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1892 for capturing the crash dump change this value to start of
1893 the reserved region. In other words, it can be set based on
1894 the "X" value as specified in the "crashkernel=YM@XM"
1895 command line boot parameter passed to the panic-ed
1896 kernel. Please take a look at Documentation/kdump/kdump.txt
1897 for more details about crash dumps.
506f1d07
SR
1898
1899 Usage of bzImage for capturing the crash dump is recommended as
1900 one does not have to build two kernels. Same kernel can be used
1901 as production kernel and capture kernel. Above option should have
1902 gone away after relocatable bzImage support is introduced. But it
1903 is present because there are users out there who continue to use
1904 vmlinux for dump capture. This option should go away down the
1905 line.
1906
1907 Don't change this unless you know what you are doing.
1908
1909config RELOCATABLE
26717808
PA
1910 bool "Build a relocatable kernel"
1911 default y
8f9ca475 1912 ---help---
506f1d07
SR
1913 This builds a kernel image that retains relocation information
1914 so it can be loaded someplace besides the default 1MB.
1915 The relocations tend to make the kernel binary about 10% larger,
1916 but are discarded at runtime.
1917
1918 One use is for the kexec on panic case where the recovery kernel
1919 must live at a different physical address than the primary
1920 kernel.
1921
1922 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1923 it has been loaded at and the compile time physical address
8ab3820f 1924 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 1925
8ab3820f 1926config RANDOMIZE_BASE
e8581e3d 1927 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 1928 depends on RELOCATABLE
8ab3820f
KC
1929 default n
1930 ---help---
e8581e3d
BH
1931 In support of Kernel Address Space Layout Randomization (KASLR),
1932 this randomizes the physical address at which the kernel image
1933 is decompressed and the virtual address where the kernel
1934 image is mapped, as a security feature that deters exploit
1935 attempts relying on knowledge of the location of kernel
1936 code internals.
1937
1938 The kernel physical and virtual address can be randomized
1939 from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
1940 using RANDOMIZE_BASE reduces the memory space available to
1941 kernel modules from 1.5GB to 1GB.)
1942
1943 Entropy is generated using the RDRAND instruction if it is
1944 supported. If RDTSC is supported, its value is mixed into
1945 the entropy pool as well. If neither RDRAND nor RDTSC are
1946 supported, then entropy is read from the i8254 timer.
1947
1948 Since the kernel is built using 2GB addressing, and
1949 PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
1950 entropy is theoretically possible. Currently, with the
1951 default value for PHYSICAL_ALIGN and due to page table
1952 layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
1953
1954 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1955 time. To enable it, boot with "kaslr" on the kernel command
1956 line (which will also disable hibernation).
8ab3820f 1957
e8581e3d 1958 If unsure, say N.
8ab3820f
KC
1959
1960# Relocation on x86 needs some additional build support
845adf72
PA
1961config X86_NEED_RELOCS
1962 def_bool y
8ab3820f 1963 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 1964
506f1d07 1965config PHYSICAL_ALIGN
a0215061 1966 hex "Alignment value to which kernel should be aligned"
8ab3820f 1967 default "0x200000"
a0215061
KC
1968 range 0x2000 0x1000000 if X86_32
1969 range 0x200000 0x1000000 if X86_64
8f9ca475 1970 ---help---
506f1d07
SR
1971 This value puts the alignment restrictions on physical address
1972 where kernel is loaded and run from. Kernel is compiled for an
1973 address which meets above alignment restriction.
1974
1975 If bootloader loads the kernel at a non-aligned address and
1976 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1977 address aligned to above value and run from there.
1978
1979 If bootloader loads the kernel at a non-aligned address and
1980 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1981 load address and decompress itself to the address it has been
1982 compiled for and run from there. The address for which kernel is
1983 compiled already meets above alignment restrictions. Hence the
1984 end result is that kernel runs from a physical address meeting
1985 above alignment restrictions.
1986
a0215061
KC
1987 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1988 this value must be a multiple of 0x200000.
1989
506f1d07
SR
1990 Don't change this unless you know what you are doing.
1991
1992config HOTPLUG_CPU
7c13e6a3 1993 bool "Support for hot-pluggable CPUs"
40b31360 1994 depends on SMP
506f1d07 1995 ---help---
7c13e6a3
DS
1996 Say Y here to allow turning CPUs off and on. CPUs can be
1997 controlled through /sys/devices/system/cpu.
1998 ( Note: power management support will enable this option
1999 automatically on SMP systems. )
2000 Say N if you want to disable CPU hotplug.
506f1d07 2001
80aa1dff
FY
2002config BOOTPARAM_HOTPLUG_CPU0
2003 bool "Set default setting of cpu0_hotpluggable"
2004 default n
2c922cd0 2005 depends on HOTPLUG_CPU
80aa1dff
FY
2006 ---help---
2007 Set whether default state of cpu0_hotpluggable is on or off.
2008
2009 Say Y here to enable CPU0 hotplug by default. If this switch
2010 is turned on, there is no need to give cpu0_hotplug kernel
2011 parameter and the CPU0 hotplug feature is enabled by default.
2012
2013 Please note: there are two known CPU0 dependencies if you want
2014 to enable the CPU0 hotplug feature either by this switch or by
2015 cpu0_hotplug kernel parameter.
2016
2017 First, resume from hibernate or suspend always starts from CPU0.
2018 So hibernate and suspend are prevented if CPU0 is offline.
2019
2020 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2021 offline if any interrupt can not migrate out of CPU0. There may
2022 be other CPU0 dependencies.
2023
2024 Please make sure the dependencies are under your control before
2025 you enable this feature.
2026
2027 Say N if you don't want to enable CPU0 hotplug feature by default.
2028 You still can enable the CPU0 hotplug feature at boot by kernel
2029 parameter cpu0_hotplug.
2030
a71c8bc5
FY
2031config DEBUG_HOTPLUG_CPU0
2032 def_bool n
2033 prompt "Debug CPU0 hotplug"
2c922cd0 2034 depends on HOTPLUG_CPU
a71c8bc5
FY
2035 ---help---
2036 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2037 soon as possible and boots up userspace with CPU0 offlined. User
2038 can online CPU0 back after boot time.
2039
2040 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2041 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2042 compilation or giving cpu0_hotplug kernel parameter at boot.
2043
2044 If unsure, say N.
2045
506f1d07 2046config COMPAT_VDSO
b0b49f26
AL
2047 def_bool n
2048 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
af65d648 2049 depends on X86_32 || IA32_EMULATION
8f9ca475 2050 ---help---
b0b49f26
AL
2051 Certain buggy versions of glibc will crash if they are
2052 presented with a 32-bit vDSO that is not mapped at the address
2053 indicated in its segment table.
e84446de 2054
b0b49f26
AL
2055 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2056 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2057 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2058 the only released version with the bug, but OpenSUSE 9
2059 contains a buggy "glibc 2.3.2".
506f1d07 2060
b0b49f26
AL
2061 The symptom of the bug is that everything crashes on startup, saying:
2062 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2063
2064 Saying Y here changes the default value of the vdso32 boot
2065 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2066 This works around the glibc bug but hurts performance.
2067
2068 If unsure, say N: if you are compiling your own kernel, you
2069 are unlikely to be using a buggy version of glibc.
506f1d07 2070
3dc33bd3
KC
2071choice
2072 prompt "vsyscall table for legacy applications"
2073 depends on X86_64
2074 default LEGACY_VSYSCALL_EMULATE
2075 help
2076 Legacy user code that does not know how to find the vDSO expects
2077 to be able to issue three syscalls by calling fixed addresses in
2078 kernel space. Since this location is not randomized with ASLR,
2079 it can be used to assist security vulnerability exploitation.
2080
2081 This setting can be changed at boot time via the kernel command
2082 line parameter vsyscall=[native|emulate|none].
2083
2084 On a system with recent enough glibc (2.14 or newer) and no
2085 static binaries, you can say None without a performance penalty
2086 to improve security.
2087
2088 If unsure, select "Emulate".
2089
2090 config LEGACY_VSYSCALL_NATIVE
2091 bool "Native"
2092 help
2093 Actual executable code is located in the fixed vsyscall
2094 address mapping, implementing time() efficiently. Since
2095 this makes the mapping executable, it can be used during
2096 security vulnerability exploitation (traditionally as
2097 ROP gadgets). This configuration is not recommended.
2098
2099 config LEGACY_VSYSCALL_EMULATE
2100 bool "Emulate"
2101 help
2102 The kernel traps and emulates calls into the fixed
2103 vsyscall address mapping. This makes the mapping
2104 non-executable, but it still contains known contents,
2105 which could be used in certain rare security vulnerability
2106 exploits. This configuration is recommended when userspace
2107 still uses the vsyscall area.
2108
2109 config LEGACY_VSYSCALL_NONE
2110 bool "None"
2111 help
2112 There will be no vsyscall mapping at all. This will
2113 eliminate any risk of ASLR bypass due to the vsyscall
2114 fixed address mapping. Attempts to use the vsyscalls
2115 will be reported to dmesg, so that either old or
2116 malicious userspace programs can be identified.
2117
2118endchoice
2119
516cbf37
TB
2120config CMDLINE_BOOL
2121 bool "Built-in kernel command line"
8f9ca475 2122 ---help---
516cbf37
TB
2123 Allow for specifying boot arguments to the kernel at
2124 build time. On some systems (e.g. embedded ones), it is
2125 necessary or convenient to provide some or all of the
2126 kernel boot arguments with the kernel itself (that is,
2127 to not rely on the boot loader to provide them.)
2128
2129 To compile command line arguments into the kernel,
2130 set this option to 'Y', then fill in the
69711ca1 2131 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2132
2133 Systems with fully functional boot loaders (i.e. non-embedded)
2134 should leave this option set to 'N'.
2135
2136config CMDLINE
2137 string "Built-in kernel command string"
2138 depends on CMDLINE_BOOL
2139 default ""
8f9ca475 2140 ---help---
516cbf37
TB
2141 Enter arguments here that should be compiled into the kernel
2142 image and used at boot time. If the boot loader provides a
2143 command line at boot time, it is appended to this string to
2144 form the full kernel command line, when the system boots.
2145
2146 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2147 change this behavior.
2148
2149 In most cases, the command line (whether built-in or provided
2150 by the boot loader) should specify the device for the root
2151 file system.
2152
2153config CMDLINE_OVERRIDE
2154 bool "Built-in command line overrides boot loader arguments"
516cbf37 2155 depends on CMDLINE_BOOL
8f9ca475 2156 ---help---
516cbf37
TB
2157 Set this option to 'Y' to have the kernel ignore the boot loader
2158 command line, and use ONLY the built-in command line.
2159
2160 This is used to work around broken boot loaders. This should
2161 be set to 'N' under normal conditions.
2162
a5b9e5a2
AL
2163config MODIFY_LDT_SYSCALL
2164 bool "Enable the LDT (local descriptor table)" if EXPERT
2165 default y
2166 ---help---
2167 Linux can allow user programs to install a per-process x86
2168 Local Descriptor Table (LDT) using the modify_ldt(2) system
2169 call. This is required to run 16-bit or segmented code such as
2170 DOSEMU or some Wine programs. It is also used by some very old
2171 threading libraries.
2172
2173 Enabling this feature adds a small amount of overhead to
2174 context switches and increases the low-level kernel attack
2175 surface. Disabling it removes the modify_ldt(2) system call.
2176
2177 Saying 'N' here may make sense for embedded or server kernels.
2178
b700e7f0
SJ
2179source "kernel/livepatch/Kconfig"
2180
506f1d07
SR
2181endmenu
2182
2183config ARCH_ENABLE_MEMORY_HOTPLUG
2184 def_bool y
2185 depends on X86_64 || (X86_32 && HIGHMEM)
2186
35551053
GH
2187config ARCH_ENABLE_MEMORY_HOTREMOVE
2188 def_bool y
2189 depends on MEMORY_HOTPLUG
2190
e534c7c5 2191config USE_PERCPU_NUMA_NODE_ID
645a7919 2192 def_bool y
e534c7c5
LS
2193 depends on NUMA
2194
9491846f
KS
2195config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2196 def_bool y
2197 depends on X86_64 || X86_PAE
2198
c177c81e
NH
2199config ARCH_ENABLE_HUGEPAGE_MIGRATION
2200 def_bool y
2201 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2202
da85f865 2203menu "Power management and ACPI options"
e279b6c1
SR
2204
2205config ARCH_HIBERNATION_HEADER
3c2362e6 2206 def_bool y
e279b6c1 2207 depends on X86_64 && HIBERNATION
e279b6c1
SR
2208
2209source "kernel/power/Kconfig"
2210
2211source "drivers/acpi/Kconfig"
2212
efafc8b2
FT
2213source "drivers/sfi/Kconfig"
2214
a6b68076 2215config X86_APM_BOOT
6fc108a0 2216 def_bool y
282e5aab 2217 depends on APM
a6b68076 2218
e279b6c1
SR
2219menuconfig APM
2220 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2221 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2222 ---help---
2223 APM is a BIOS specification for saving power using several different
2224 techniques. This is mostly useful for battery powered laptops with
2225 APM compliant BIOSes. If you say Y here, the system time will be
2226 reset after a RESUME operation, the /proc/apm device will provide
2227 battery status information, and user-space programs will receive
2228 notification of APM "events" (e.g. battery status change).
2229
2230 If you select "Y" here, you can disable actual use of the APM
2231 BIOS by passing the "apm=off" option to the kernel at boot time.
2232
2233 Note that the APM support is almost completely disabled for
2234 machines with more than one CPU.
2235
2236 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2237 and more information, read <file:Documentation/power/apm-acpi.txt>
2238 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2239 <http://www.tldp.org/docs.html#howto>.
2240
2241 This driver does not spin down disk drives (see the hdparm(8)
2242 manpage ("man 8 hdparm") for that), and it doesn't turn off
2243 VESA-compliant "green" monitors.
2244
2245 This driver does not support the TI 4000M TravelMate and the ACER
2246 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2247 desktop machines also don't have compliant BIOSes, and this driver
2248 may cause those machines to panic during the boot phase.
2249
2250 Generally, if you don't have a battery in your machine, there isn't
2251 much point in using this driver and you should say N. If you get
2252 random kernel OOPSes or reboots that don't seem to be related to
2253 anything, try disabling/enabling this option (or disabling/enabling
2254 APM in your BIOS).
2255
2256 Some other things you should try when experiencing seemingly random,
2257 "weird" problems:
2258
2259 1) make sure that you have enough swap space and that it is
2260 enabled.
2261 2) pass the "no-hlt" option to the kernel
2262 3) switch on floating point emulation in the kernel and pass
2263 the "no387" option to the kernel
2264 4) pass the "floppy=nodma" option to the kernel
2265 5) pass the "mem=4M" option to the kernel (thereby disabling
2266 all but the first 4 MB of RAM)
2267 6) make sure that the CPU is not over clocked.
2268 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2269 8) disable the cache from your BIOS settings
2270 9) install a fan for the video card or exchange video RAM
2271 10) install a better fan for the CPU
2272 11) exchange RAM chips
2273 12) exchange the motherboard.
2274
2275 To compile this driver as a module, choose M here: the
2276 module will be called apm.
2277
2278if APM
2279
2280config APM_IGNORE_USER_SUSPEND
2281 bool "Ignore USER SUSPEND"
8f9ca475 2282 ---help---
e279b6c1
SR
2283 This option will ignore USER SUSPEND requests. On machines with a
2284 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2285 series notebooks, it is necessary to say Y because of a BIOS bug.
2286
2287config APM_DO_ENABLE
2288 bool "Enable PM at boot time"
2289 ---help---
2290 Enable APM features at boot time. From page 36 of the APM BIOS
2291 specification: "When disabled, the APM BIOS does not automatically
2292 power manage devices, enter the Standby State, enter the Suspend
2293 State, or take power saving steps in response to CPU Idle calls."
2294 This driver will make CPU Idle calls when Linux is idle (unless this
2295 feature is turned off -- see "Do CPU IDLE calls", below). This
2296 should always save battery power, but more complicated APM features
2297 will be dependent on your BIOS implementation. You may need to turn
2298 this option off if your computer hangs at boot time when using APM
2299 support, or if it beeps continuously instead of suspending. Turn
2300 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2301 T400CDT. This is off by default since most machines do fine without
2302 this feature.
2303
2304config APM_CPU_IDLE
dd8af076 2305 depends on CPU_IDLE
e279b6c1 2306 bool "Make CPU Idle calls when idle"
8f9ca475 2307 ---help---
e279b6c1
SR
2308 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2309 On some machines, this can activate improved power savings, such as
2310 a slowed CPU clock rate, when the machine is idle. These idle calls
2311 are made after the idle loop has run for some length of time (e.g.,
2312 333 mS). On some machines, this will cause a hang at boot time or
2313 whenever the CPU becomes idle. (On machines with more than one CPU,
2314 this option does nothing.)
2315
2316config APM_DISPLAY_BLANK
2317 bool "Enable console blanking using APM"
8f9ca475 2318 ---help---
e279b6c1
SR
2319 Enable console blanking using the APM. Some laptops can use this to
2320 turn off the LCD backlight when the screen blanker of the Linux
2321 virtual console blanks the screen. Note that this is only used by
2322 the virtual console screen blanker, and won't turn off the backlight
2323 when using the X Window system. This also doesn't have anything to
2324 do with your VESA-compliant power-saving monitor. Further, this
2325 option doesn't work for all laptops -- it might not turn off your
2326 backlight at all, or it might print a lot of errors to the console,
2327 especially if you are using gpm.
2328
2329config APM_ALLOW_INTS
2330 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2331 ---help---
e279b6c1
SR
2332 Normally we disable external interrupts while we are making calls to
2333 the APM BIOS as a measure to lessen the effects of a badly behaving
2334 BIOS implementation. The BIOS should reenable interrupts if it
2335 needs to. Unfortunately, some BIOSes do not -- especially those in
2336 many of the newer IBM Thinkpads. If you experience hangs when you
2337 suspend, try setting this to Y. Otherwise, say N.
2338
e279b6c1
SR
2339endif # APM
2340
bb0a56ec 2341source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2342
2343source "drivers/cpuidle/Kconfig"
2344
27471fdb
AH
2345source "drivers/idle/Kconfig"
2346
e279b6c1
SR
2347endmenu
2348
2349
2350menu "Bus options (PCI etc.)"
2351
2352config PCI
1ac97018 2353 bool "PCI support"
1c858087 2354 default y
8f9ca475 2355 ---help---
e279b6c1
SR
2356 Find out whether you have a PCI motherboard. PCI is the name of a
2357 bus system, i.e. the way the CPU talks to the other stuff inside
2358 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2359 VESA. If you have PCI, say Y, otherwise N.
2360
e279b6c1
SR
2361choice
2362 prompt "PCI access mode"
efefa6f6 2363 depends on X86_32 && PCI
e279b6c1
SR
2364 default PCI_GOANY
2365 ---help---
2366 On PCI systems, the BIOS can be used to detect the PCI devices and
2367 determine their configuration. However, some old PCI motherboards
2368 have BIOS bugs and may crash if this is done. Also, some embedded
2369 PCI-based systems don't have any BIOS at all. Linux can also try to
2370 detect the PCI hardware directly without using the BIOS.
2371
2372 With this option, you can specify how Linux should detect the
2373 PCI devices. If you choose "BIOS", the BIOS will be used,
2374 if you choose "Direct", the BIOS won't be used, and if you
2375 choose "MMConfig", then PCI Express MMCONFIG will be used.
2376 If you choose "Any", the kernel will try MMCONFIG, then the
2377 direct access method and falls back to the BIOS if that doesn't
2378 work. If unsure, go with the default, which is "Any".
2379
2380config PCI_GOBIOS
2381 bool "BIOS"
2382
2383config PCI_GOMMCONFIG
2384 bool "MMConfig"
2385
2386config PCI_GODIRECT
2387 bool "Direct"
2388
3ef0e1f8 2389config PCI_GOOLPC
76fb6570 2390 bool "OLPC XO-1"
3ef0e1f8
AS
2391 depends on OLPC
2392
2bdd1b03
AS
2393config PCI_GOANY
2394 bool "Any"
2395
e279b6c1
SR
2396endchoice
2397
2398config PCI_BIOS
3c2362e6 2399 def_bool y
efefa6f6 2400 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2401
2402# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2403config PCI_DIRECT
3c2362e6 2404 def_bool y
0aba496f 2405 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2406
2407config PCI_MMCONFIG
3c2362e6 2408 def_bool y
5f0db7a2 2409 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2410
3ef0e1f8 2411config PCI_OLPC
2bdd1b03
AS
2412 def_bool y
2413 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2414
b5401a96
AN
2415config PCI_XEN
2416 def_bool y
2417 depends on PCI && XEN
2418 select SWIOTLB_XEN
2419
e279b6c1 2420config PCI_DOMAINS
3c2362e6 2421 def_bool y
e279b6c1 2422 depends on PCI
e279b6c1
SR
2423
2424config PCI_MMCONFIG
2425 bool "Support mmconfig PCI config space access"
2426 depends on X86_64 && PCI && ACPI
2427
3f6ea84a 2428config PCI_CNB20LE_QUIRK
6a108a14 2429 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2430 depends on PCI
3f6ea84a
IS
2431 help
2432 Read the PCI windows out of the CNB20LE host bridge. This allows
2433 PCI hotplug to work on systems with the CNB20LE chipset which do
2434 not have ACPI.
2435
64a5fed6
BH
2436 There's no public spec for this chipset, and this functionality
2437 is known to be incomplete.
2438
2439 You should say N unless you know you need this.
2440
e279b6c1
SR
2441source "drivers/pci/Kconfig"
2442
3a495511
WBG
2443config ISA_BUS
2444 bool "ISA-style bus support on modern systems" if EXPERT
2445 select ISA_BUS_API
2446 help
2447 Enables ISA-style drivers on modern systems. This is necessary to
2448 support PC/104 devices on X86_64 platforms.
2449
2450 If unsure, say N.
2451
1c00f016 2452# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2453config ISA_DMA_API
1c00f016
DR
2454 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2455 default y
2456 help
2457 Enables ISA-style DMA support for devices requiring such controllers.
2458 If unsure, say Y.
e279b6c1 2459
51e68d05
LT
2460if X86_32
2461
e279b6c1
SR
2462config ISA
2463 bool "ISA support"
8f9ca475 2464 ---help---
e279b6c1
SR
2465 Find out whether you have ISA slots on your motherboard. ISA is the
2466 name of a bus system, i.e. the way the CPU talks to the other stuff
2467 inside your box. Other bus systems are PCI, EISA, MicroChannel
2468 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2469 newer boards don't support it. If you have ISA, say Y, otherwise N.
2470
2471config EISA
2472 bool "EISA support"
2473 depends on ISA
2474 ---help---
2475 The Extended Industry Standard Architecture (EISA) bus was
2476 developed as an open alternative to the IBM MicroChannel bus.
2477
2478 The EISA bus provided some of the features of the IBM MicroChannel
2479 bus while maintaining backward compatibility with cards made for
2480 the older ISA bus. The EISA bus saw limited use between 1988 and
2481 1995 when it was made obsolete by the PCI bus.
2482
2483 Say Y here if you are building a kernel for an EISA-based machine.
2484
2485 Otherwise, say N.
2486
2487source "drivers/eisa/Kconfig"
2488
e279b6c1
SR
2489config SCx200
2490 tristate "NatSemi SCx200 support"
8f9ca475 2491 ---help---
e279b6c1
SR
2492 This provides basic support for National Semiconductor's
2493 (now AMD's) Geode processors. The driver probes for the
2494 PCI-IDs of several on-chip devices, so its a good dependency
2495 for other scx200_* drivers.
2496
2497 If compiled as a module, the driver is named scx200.
2498
2499config SCx200HR_TIMER
2500 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2501 depends on SCx200
e279b6c1 2502 default y
8f9ca475 2503 ---help---
e279b6c1
SR
2504 This driver provides a clocksource built upon the on-chip
2505 27MHz high-resolution timer. Its also a workaround for
2506 NSC Geode SC-1100's buggy TSC, which loses time when the
2507 processor goes idle (as is done by the scheduler). The
2508 other workaround is idle=poll boot option.
2509
3ef0e1f8
AS
2510config OLPC
2511 bool "One Laptop Per Child support"
54008979 2512 depends on !X86_PAE
3c554946 2513 select GPIOLIB
dc3119e7 2514 select OF
45bb1674 2515 select OF_PROMTREE
b4e51854 2516 select IRQ_DOMAIN
8f9ca475 2517 ---help---
3ef0e1f8
AS
2518 Add support for detecting the unique features of the OLPC
2519 XO hardware.
2520
a3128588
DD
2521config OLPC_XO1_PM
2522 bool "OLPC XO-1 Power Management"
97c4cb71 2523 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2524 select MFD_CORE
bf1ebf00 2525 ---help---
97c4cb71 2526 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2527
cfee9597
DD
2528config OLPC_XO1_RTC
2529 bool "OLPC XO-1 Real Time Clock"
2530 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2531 ---help---
2532 Add support for the XO-1 real time clock, which can be used as a
2533 programmable wakeup source.
2534
7feda8e9
DD
2535config OLPC_XO1_SCI
2536 bool "OLPC XO-1 SCI extras"
d8d01a63 2537 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2538 depends on INPUT=y
d8d01a63 2539 select POWER_SUPPLY
7feda8e9
DD
2540 select GPIO_CS5535
2541 select MFD_CORE
2542 ---help---
2543 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2544 - EC-driven system wakeups
7feda8e9 2545 - Power button
7bc74b3d 2546 - Ebook switch
2cf2baea 2547 - Lid switch
e1040ac6
DD
2548 - AC adapter status updates
2549 - Battery status updates
7feda8e9 2550
a0f30f59
DD
2551config OLPC_XO15_SCI
2552 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2553 depends on OLPC && ACPI
2554 select POWER_SUPPLY
a0f30f59
DD
2555 ---help---
2556 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2557 - EC-driven system wakeups
2558 - AC adapter status updates
2559 - Battery status updates
bf1ebf00 2560
d4f3e350
EW
2561config ALIX
2562 bool "PCEngines ALIX System Support (LED setup)"
2563 select GPIOLIB
2564 ---help---
2565 This option enables system support for the PCEngines ALIX.
2566 At present this just sets up LEDs for GPIO control on
2567 ALIX2/3/6 boards. However, other system specific setup should
2568 get added here.
2569
2570 Note: You must still enable the drivers for GPIO and LED support
2571 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2572
2573 Note: You have to set alix.force=1 for boards with Award BIOS.
2574
da4e3302
PP
2575config NET5501
2576 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2577 select GPIOLIB
2578 ---help---
2579 This option enables system support for the Soekris Engineering net5501.
2580
3197059a
PP
2581config GEOS
2582 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2583 select GPIOLIB
2584 depends on DMI
2585 ---help---
2586 This option enables system support for the Traverse Technologies GEOS.
2587
7d029125
VD
2588config TS5500
2589 bool "Technologic Systems TS-5500 platform support"
2590 depends on MELAN
2591 select CHECK_SIGNATURE
2592 select NEW_LEDS
2593 select LEDS_CLASS
2594 ---help---
2595 This option enables system support for the Technologic Systems TS-5500.
2596
bc0120fd
SR
2597endif # X86_32
2598
23ac4ae8 2599config AMD_NB
e279b6c1 2600 def_bool y
0e152cd7 2601 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2602
2603source "drivers/pcmcia/Kconfig"
2604
388b78ad 2605config RAPIDIO
fdf90abc 2606 tristate "RapidIO support"
388b78ad
AB
2607 depends on PCI
2608 default n
2609 help
fdf90abc 2610 If enabled this option will include drivers and the core
388b78ad
AB
2611 infrastructure code to support RapidIO interconnect devices.
2612
2613source "drivers/rapidio/Kconfig"
2614
e3263ab3
DH
2615config X86_SYSFB
2616 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2617 help
2618 Firmwares often provide initial graphics framebuffers so the BIOS,
2619 bootloader or kernel can show basic video-output during boot for
2620 user-guidance and debugging. Historically, x86 used the VESA BIOS
2621 Extensions and EFI-framebuffers for this, which are mostly limited
2622 to x86.
2623 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2624 framebuffers so the new generic system-framebuffer drivers can be
2625 used on x86. If the framebuffer is not compatible with the generic
2626 modes, it is adverticed as fallback platform framebuffer so legacy
2627 drivers like efifb, vesafb and uvesafb can pick it up.
2628 If this option is not selected, all system framebuffers are always
2629 marked as fallback platform framebuffers as usual.
2630
2631 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2632 not be able to pick up generic system framebuffers if this option
2633 is selected. You are highly encouraged to enable simplefb as
2634 replacement if you select this option. simplefb can correctly deal
2635 with generic system framebuffers. But you should still keep vesafb
2636 and others enabled as fallback if a system framebuffer is
2637 incompatible with simplefb.
2638
2639 If unsure, say Y.
2640
e279b6c1
SR
2641endmenu
2642
2643
2644menu "Executable file formats / Emulations"
2645
2646source "fs/Kconfig.binfmt"
2647
2648config IA32_EMULATION
2649 bool "IA32 Emulation"
2650 depends on X86_64
d1603990 2651 select BINFMT_ELF
a97f52e6 2652 select COMPAT_BINFMT_ELF
3bead553 2653 select ARCH_WANT_OLD_COMPAT_IPC
8f9ca475 2654 ---help---
5fd92e65
L
2655 Include code to run legacy 32-bit programs under a
2656 64-bit kernel. You should likely turn this on, unless you're
2657 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2658
2659config IA32_AOUT
8f9ca475
IM
2660 tristate "IA32 a.out support"
2661 depends on IA32_EMULATION
2662 ---help---
2663 Support old a.out binaries in the 32bit emulation.
e279b6c1 2664
0bf62763 2665config X86_X32
6ea30386 2666 bool "x32 ABI for 64-bit mode"
9b54050b 2667 depends on X86_64
5fd92e65
L
2668 ---help---
2669 Include code to run binaries for the x32 native 32-bit ABI
2670 for 64-bit processors. An x32 process gets access to the
2671 full 64-bit register file and wide data path while leaving
2672 pointers at 32 bits for smaller memory footprint.
2673
2674 You will need a recent binutils (2.22 or later) with
2675 elf32_x86_64 support enabled to compile a kernel with this
2676 option set.
2677
e279b6c1 2678config COMPAT
3c2362e6 2679 def_bool y
0bf62763 2680 depends on IA32_EMULATION || X86_X32
e279b6c1 2681
3120e25e 2682if COMPAT
e279b6c1 2683config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2684 def_bool y
e279b6c1
SR
2685
2686config SYSVIPC_COMPAT
3c2362e6 2687 def_bool y
3120e25e 2688 depends on SYSVIPC
e279b6c1 2689
ee009e4a 2690config KEYS_COMPAT
3120e25e
JB
2691 def_bool y
2692 depends on KEYS
2693endif
ee009e4a 2694
e279b6c1
SR
2695endmenu
2696
2697
e5beae16
KP
2698config HAVE_ATOMIC_IOMAP
2699 def_bool y
2700 depends on X86_32
2701
4692d77f
AR
2702config X86_DEV_DMA_OPS
2703 bool
83125a3a 2704 depends on X86_64 || STA2X11
4692d77f 2705
f7219a53
AR
2706config X86_DMA_REMAP
2707 bool
83125a3a 2708 depends on STA2X11
f7219a53 2709
93e5eadd
LA
2710config PMC_ATOM
2711 def_bool y
2712 depends on PCI
2713
185a383a
KB
2714config VMD
2715 depends on PCI_MSI
2716 tristate "Volume Management Device Driver"
2717 default N
2718 ---help---
2719 Adds support for the Intel Volume Management Device (VMD). VMD is a
2720 secondary PCI host bridge that allows PCI Express root ports,
2721 and devices attached to them, to be removed from the default
2722 PCI domain and placed within the VMD domain. This provides
2723 more bus resources than are otherwise possible with a
2724 single domain. If you know your system provides one of these and
2725 has devices attached to it, say Y; if you are not sure, say N.
2726
e279b6c1
SR
2727source "net/Kconfig"
2728
2729source "drivers/Kconfig"
2730
2731source "drivers/firmware/Kconfig"
2732
2733source "fs/Kconfig"
2734
e279b6c1
SR
2735source "arch/x86/Kconfig.debug"
2736
2737source "security/Kconfig"
2738
2739source "crypto/Kconfig"
2740
edf88417
AK
2741source "arch/x86/kvm/Kconfig"
2742
e279b6c1 2743source "lib/Kconfig"