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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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SR
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
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
446f24d1 26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
21266be9 27 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 28 select ARCH_HAS_ELF_RANDOMIZE
72d93104 29 select ARCH_HAS_FAST_MULTIPLIER
957e3fac 30 select ARCH_HAS_GCOV_PROFILE_ALL
96601adb 31 select ARCH_HAS_PMEM_API if X86_64
67a3e8fe 32 select ARCH_HAS_MMIO_FLUSH
6471b825 33 select ARCH_HAS_SG_CHAIN
c6d30853 34 select ARCH_HAS_UBSAN_SANITIZE_ALL
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IM
35 select ARCH_HAVE_NMI_SAFE_CMPXCHG
36 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 37 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 38 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 39 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 40 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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IM
41 select ARCH_SUPPORTS_INT128 if X86_64
42 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
43 select ARCH_USE_BUILTIN_BSWAP
44 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
45 select ARCH_USE_QUEUED_RWLOCKS
46 select ARCH_USE_QUEUED_SPINLOCKS
72b252ae 47 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
5aaeb5c0 48 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
da4276b8 49 select ARCH_WANT_FRAME_POINTERS
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50 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
51 select ARCH_WANT_OPTIONAL_GPIOLIB
52 select BUILDTIME_EXTABLE_SORT
53 select CLKEVT_I8253
54 select CLKSRC_I8253 if X86_32
55 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
56 select CLOCKSOURCE_WATCHDOG
57 select CLONE_BACKWARDS if X86_32
58 select COMPAT_OLD_SIGACTION if IA32_EMULATION
59 select DCACHE_WORD_ACCESS
45471cd9
LT
60 select EDAC_ATOMIC_SCRUB
61 select EDAC_SUPPORT
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62 select GENERIC_CLOCKEVENTS
63 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
64 select GENERIC_CLOCKEVENTS_MIN_ADJUST
65 select GENERIC_CMOS_UPDATE
66 select GENERIC_CPU_AUTOPROBE
5b7c73e0 67 select GENERIC_EARLY_IOREMAP
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68 select GENERIC_FIND_FIRST_BIT
69 select GENERIC_IOMAP
70 select GENERIC_IRQ_PROBE
71 select GENERIC_IRQ_SHOW
72 select GENERIC_PENDING_IRQ if SMP
73 select GENERIC_SMP_IDLE_THREAD
74 select GENERIC_STRNCPY_FROM_USER
75 select GENERIC_STRNLEN_USER
76 select GENERIC_TIME_VSYSCALL
77 select HAVE_ACPI_APEI if ACPI
78 select HAVE_ACPI_APEI_NMI if ACPI
79 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
80 select HAVE_AOUT if X86_32
81 select HAVE_ARCH_AUDITSYSCALL
82 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
83 select HAVE_ARCH_JUMP_LABEL
84 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
85 select HAVE_ARCH_KGDB
86 select HAVE_ARCH_KMEMCHECK
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87 select HAVE_ARCH_MMAP_RND_BITS if MMU
88 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
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89 select HAVE_ARCH_SECCOMP_FILTER
90 select HAVE_ARCH_SOFT_DIRTY if X86_64
91 select HAVE_ARCH_TRACEHOOK
92 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
93 select HAVE_BPF_JIT if X86_64
94 select HAVE_CC_STACKPROTECTOR
95 select HAVE_CMPXCHG_DOUBLE
96 select HAVE_CMPXCHG_LOCAL
97 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 98 select HAVE_COPY_THREAD_TLS
cf4db259 99 select HAVE_C_RECORDMCOUNT
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100 select HAVE_DEBUG_KMEMLEAK
101 select HAVE_DEBUG_STACKOVERFLOW
102 select HAVE_DMA_API_DEBUG
6471b825 103 select HAVE_DMA_CONTIGUOUS
677aa9f7 104 select HAVE_DYNAMIC_FTRACE
06aeaaea 105 select HAVE_DYNAMIC_FTRACE_WITH_REGS
58340a07 106 select HAVE_EFFICIENT_UNALIGNED_ACCESS
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107 select HAVE_FENTRY if X86_64
108 select HAVE_FTRACE_MCOUNT_RECORD
109 select HAVE_FUNCTION_GRAPH_FP_TEST
110 select HAVE_FUNCTION_GRAPH_TRACER
111 select HAVE_FUNCTION_TRACER
112 select HAVE_GENERIC_DMA_COHERENT if X86_32
113 select HAVE_HW_BREAKPOINT
114 select HAVE_IDE
115 select HAVE_IOREMAP_PROT
116 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
117 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 118 select HAVE_KERNEL_BZIP2
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119 select HAVE_KERNEL_GZIP
120 select HAVE_KERNEL_LZ4
2e9f3bdd 121 select HAVE_KERNEL_LZMA
13510997 122 select HAVE_KERNEL_LZO
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123 select HAVE_KERNEL_XZ
124 select HAVE_KPROBES
125 select HAVE_KPROBES_ON_FTRACE
126 select HAVE_KRETPROBES
127 select HAVE_KVM
128 select HAVE_LIVEPATCH if X86_64
129 select HAVE_MEMBLOCK
130 select HAVE_MEMBLOCK_NODE_MAP
0102752e 131 select HAVE_MIXED_BREAKPOINTS_REGS
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132 select HAVE_OPROFILE
133 select HAVE_OPTPROBES
134 select HAVE_PCSPKR_PLATFORM
135 select HAVE_PERF_EVENTS
c01d4323 136 select HAVE_PERF_EVENTS_NMI
c5e63197 137 select HAVE_PERF_REGS
c5ebcedb 138 select HAVE_PERF_USER_STACK_DUMP
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139 select HAVE_REGS_AND_STACK_ACCESS_API
140 select HAVE_SYSCALL_TRACEPOINTS
0c3619ea 141 select HAVE_UID16 if X86_32 || IA32_EMULATION
6471b825 142 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 143 select HAVE_USER_RETURN_NOTIFIER
c0185808 144 select IRQ_FORCED_THREADING
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145 select MODULES_USE_ELF_RELA if X86_64
146 select MODULES_USE_ELF_REL if X86_32
147 select OLD_SIGACTION if X86_32
148 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
149 select PERF_EVENTS
3195ef59 150 select RTC_LIB
6471b825 151 select SPARSE_IRQ
83fe27ea 152 select SRCU
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IM
153 select SYSCTL_EXCEPTION_TRACE
154 select USER_STACKTRACE_SUPPORT
155 select VIRT_TO_BUS
156 select X86_DEV_DMA_OPS if X86_64
157 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 158
ba7e4d13 159config INSTRUCTION_DECODER
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160 def_bool y
161 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 162
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LT
163config OUTPUT_FORMAT
164 string
165 default "elf32-i386" if X86_32
166 default "elf64-x86-64" if X86_64
167
73531905 168config ARCH_DEFCONFIG
b9b39bfb 169 string
73531905
SR
170 default "arch/x86/configs/i386_defconfig" if X86_32
171 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 172
8d5fffb9 173config LOCKDEP_SUPPORT
3c2362e6 174 def_bool y
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SR
175
176config STACKTRACE_SUPPORT
3c2362e6 177 def_bool y
8d5fffb9 178
8d5fffb9 179config MMU
3c2362e6 180 def_bool y
8d5fffb9 181
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DC
182config ARCH_MMAP_RND_BITS_MIN
183 default 28 if 64BIT
184 default 8
185
186config ARCH_MMAP_RND_BITS_MAX
187 default 32 if 64BIT
188 default 16
189
190config ARCH_MMAP_RND_COMPAT_BITS_MIN
191 default 8
192
193config ARCH_MMAP_RND_COMPAT_BITS_MAX
194 default 16
195
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196config SBUS
197 bool
198
3bc4e459 199config NEED_DMA_MAP_STATE
3120e25e 200 def_bool y
a6dfa128 201 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 202
18e98307 203config NEED_SG_DMA_LENGTH
4a14d84e 204 def_bool y
18e98307 205
8d5fffb9 206config GENERIC_ISA_DMA
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207 def_bool y
208 depends on ISA_DMA_API
8d5fffb9 209
8d5fffb9 210config GENERIC_BUG
3c2362e6 211 def_bool y
8d5fffb9 212 depends on BUG
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213 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
214
215config GENERIC_BUG_RELATIVE_POINTERS
216 bool
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217
218config GENERIC_HWEIGHT
3c2362e6 219 def_bool y
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220
221config ARCH_MAY_HAVE_PC_FDC
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222 def_bool y
223 depends on ISA_DMA_API
8d5fffb9 224
1032c0ba 225config RWSEM_XCHGADD_ALGORITHM
3120e25e 226 def_bool y
1032c0ba 227
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SR
228config GENERIC_CALIBRATE_DELAY
229 def_bool y
230
9a0b8415 231config ARCH_HAS_CPU_RELAX
232 def_bool y
233
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PE
234config ARCH_HAS_CACHE_LINE_SIZE
235 def_bool y
236
dd5af90a 237config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 238 def_bool y
b32ef636 239
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TH
240config NEED_PER_CPU_EMBED_FIRST_CHUNK
241 def_bool y
242
243config NEED_PER_CPU_PAGE_FIRST_CHUNK
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TH
244 def_bool y
245
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246config ARCH_HIBERNATION_POSSIBLE
247 def_bool y
801e4062 248
f4cb5700
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249config ARCH_SUSPEND_POSSIBLE
250 def_bool y
f4cb5700 251
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SC
252config ARCH_WANT_HUGE_PMD_SHARE
253 def_bool y
254
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SC
255config ARCH_WANT_GENERAL_HUGETLB
256 def_bool y
257
8d5fffb9 258config ZONE_DMA32
e0fd24a3 259 def_bool y if X86_64
8d5fffb9 260
8d5fffb9 261config AUDIT_ARCH
e0fd24a3 262 def_bool y if X86_64
8d5fffb9 263
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264config ARCH_SUPPORTS_OPTIMIZED_INLINING
265 def_bool y
266
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AM
267config ARCH_SUPPORTS_DEBUG_PAGEALLOC
268 def_bool y
269
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AR
270config KASAN_SHADOW_OFFSET
271 hex
272 depends on KASAN
273 default 0xdffffc0000000000
274
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SW
275config HAVE_INTEL_TXT
276 def_bool y
6ea30386 277 depends on INTEL_IOMMU && ACPI
69575d38 278
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SR
279config X86_32_SMP
280 def_bool y
281 depends on X86_32 && SMP
282
283config X86_64_SMP
284 def_bool y
285 depends on X86_64 && SMP
286
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287config X86_32_LAZY_GS
288 def_bool y
60a5317f 289 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 290
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BP
291config ARCH_HWEIGHT_CFLAGS
292 string
293 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
294 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
295
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SD
296config ARCH_SUPPORTS_UPROBES
297 def_bool y
298
d20642f0
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299config FIX_EARLYCON_MEM
300 def_bool y
301
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302config DEBUG_RODATA
303 def_bool y
304
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305config PGTABLE_LEVELS
306 int
307 default 4 if X86_64
308 default 3 if X86_PAE
309 default 2
310
506f1d07 311source "init/Kconfig"
dc52ddc0 312source "kernel/Kconfig.freezer"
8d5fffb9 313
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SR
314menu "Processor type and features"
315
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RD
316config ZONE_DMA
317 bool "DMA memory allocation support" if EXPERT
318 default y
319 help
320 DMA memory allocation support allows devices with less than 32-bit
321 addressing to allocate within the first 16MB of address space.
322 Disable if no such devices will be used.
323
324 If unsure, say Y.
325
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SR
326config SMP
327 bool "Symmetric multi-processing support"
328 ---help---
329 This enables support for systems with more than one CPU. If you have
4a474157
RG
330 a system with only one CPU, say N. If you have a system with more
331 than one CPU, say Y.
506f1d07 332
4a474157 333 If you say N here, the kernel will run on uni- and multiprocessor
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SR
334 machines, but will use only one CPU of a multiprocessor machine. If
335 you say Y here, the kernel will run on many, but not all,
4a474157 336 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
337 will run faster if you say N here.
338
339 Note that if you say Y here and choose architecture "586" or
340 "Pentium" under "Processor family", the kernel will not work on 486
341 architectures. Similarly, multiprocessor kernels for the "PPro"
342 architecture may not work on all Pentium based boards.
343
344 People using multiprocessor machines who say Y here should also say
345 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
346 Management" code will be disabled if you say Y here.
347
395cf969 348 See also <file:Documentation/x86/i386/IO-APIC.txt>,
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SR
349 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
350 <http://www.tldp.org/docs.html#howto>.
351
352 If you don't know what to do here, say N.
353
9def39be
JT
354config X86_FEATURE_NAMES
355 bool "Processor feature human-readable names" if EMBEDDED
356 default y
357 ---help---
358 This option compiles in a table of x86 feature bits and corresponding
359 names. This is required to support /proc/cpuinfo and a few kernel
360 messages. You can disable this to save space, at the expense of
361 making those few kernel messages show numeric feature bits instead.
362
363 If in doubt, say Y.
364
6e1315fe
BP
365config X86_FAST_FEATURE_TESTS
366 bool "Fast CPU feature tests" if EMBEDDED
367 default y
368 ---help---
369 Some fast-paths in the kernel depend on the capabilities of the CPU.
370 Say Y here for the kernel to patch in the appropriate code at runtime
371 based on the capabilities of the CPU. The infrastructure for patching
372 code at runtime takes up some additional space; space-constrained
373 embedded systems may wish to say N here to produce smaller, slightly
374 slower code.
375
06cd9a7d
YL
376config X86_X2APIC
377 bool "Support x2apic"
19e3d60d 378 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
379 ---help---
380 This enables x2apic support on CPUs that have this feature.
381
382 This allows 32-bit apic IDs (so it can support very large systems),
383 and accesses the local apic via MSRs not via mmio.
384
06cd9a7d
YL
385 If you don't know what to do here, say N.
386
6695c85b 387config X86_MPPARSE
6e87f9b7 388 bool "Enable MPS table" if ACPI || SFI
7a527688 389 default y
5ab74722 390 depends on X86_LOCAL_APIC
8f9ca475 391 ---help---
6695c85b
YL
392 For old smp systems that do not have proper acpi support. Newer systems
393 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 394
26f7ef14
YL
395config X86_BIGSMP
396 bool "Support for big SMP systems with more than 8 CPUs"
397 depends on X86_32 && SMP
8f9ca475 398 ---help---
26f7ef14 399 This option is needed for the systems that have more than 8 CPUs
506f1d07 400
ddd70cf9
JN
401config GOLDFISH
402 def_bool y
403 depends on X86_GOLDFISH
404
8425091f 405if X86_32
c5c606d9
RT
406config X86_EXTENDED_PLATFORM
407 bool "Support for extended (non-PC) x86 platforms"
408 default y
8f9ca475 409 ---help---
06ac8346
IM
410 If you disable this option then the kernel will only support
411 standard PC platforms. (which covers the vast majority of
412 systems out there.)
413
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RT
414 If you enable this option then you'll be able to select support
415 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 416 Goldfish (Android emulator)
8425091f 417 AMD Elan
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RT
418 RDC R-321x SoC
419 SGI 320/540 (Visual Workstation)
83125a3a 420 STA2X11-based (e.g. Northville)
3f4110a4 421 Moorestown MID devices
06ac8346
IM
422
423 If you have one of these systems, or if you want to build a
424 generic distribution kernel, say Y here - otherwise say N.
8425091f 425endif
06ac8346 426
8425091f
RT
427if X86_64
428config X86_EXTENDED_PLATFORM
429 bool "Support for extended (non-PC) x86 platforms"
430 default y
431 ---help---
432 If you disable this option then the kernel will only support
433 standard PC platforms. (which covers the vast majority of
434 systems out there.)
435
436 If you enable this option then you'll be able to select support
437 for the following (non-PC) 64 bit x86 platforms:
44b111b5 438 Numascale NumaChip
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RT
439 ScaleMP vSMP
440 SGI Ultraviolet
441
442 If you have one of these systems, or if you want to build a
443 generic distribution kernel, say Y here - otherwise say N.
444endif
c5c606d9
RT
445# This is an alphabetically sorted list of 64 bit extended platforms
446# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
447config X86_NUMACHIP
448 bool "Numascale NumaChip"
449 depends on X86_64
450 depends on X86_EXTENDED_PLATFORM
451 depends on NUMA
452 depends on SMP
453 depends on X86_X2APIC
f9726bfd 454 depends on PCI_MMCONFIG
44b111b5
SP
455 ---help---
456 Adds support for Numascale NumaChip large-SMP systems. Needed to
457 enable more than ~168 cores.
458 If you don't have one of these, you should say N here.
506f1d07 459
c5c606d9
RT
460config X86_VSMP
461 bool "ScaleMP vSMP"
6276a074 462 select HYPERVISOR_GUEST
c5c606d9
RT
463 select PARAVIRT
464 depends on X86_64 && PCI
465 depends on X86_EXTENDED_PLATFORM
ead91d4b 466 depends on SMP
8f9ca475 467 ---help---
c5c606d9
RT
468 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
469 supposed to run on these EM64T-based machines. Only choose this option
470 if you have one of these machines.
5e3a77e9 471
03b48632
NP
472config X86_UV
473 bool "SGI Ultraviolet"
474 depends on X86_64
c5c606d9 475 depends on X86_EXTENDED_PLATFORM
54c28d29 476 depends on NUMA
1ecb4ae5 477 depends on EFI
9d6c26e7 478 depends on X86_X2APIC
1222e564 479 depends on PCI
8f9ca475 480 ---help---
03b48632
NP
481 This option is needed in order to support SGI Ultraviolet systems.
482 If you don't have one of these, you should say N here.
483
c5c606d9
RT
484# Following is an alphabetically sorted list of 32 bit extended platforms
485# Please maintain the alphabetic order if and when there are additions
506f1d07 486
ddd70cf9
JN
487config X86_GOLDFISH
488 bool "Goldfish (Virtual Platform)"
cb7b8023 489 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
490 ---help---
491 Enable support for the Goldfish virtual platform used primarily
492 for Android development. Unless you are building for the Android
493 Goldfish emulator say N here.
494
c751e17b
TG
495config X86_INTEL_CE
496 bool "CE4100 TV platform"
497 depends on PCI
498 depends on PCI_GODIRECT
6084a6e2 499 depends on X86_IO_APIC
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TG
500 depends on X86_32
501 depends on X86_EXTENDED_PLATFORM
37bc9f50 502 select X86_REBOOTFIXUPS
da6b737b
SAS
503 select OF
504 select OF_EARLY_FLATTREE
c751e17b
TG
505 ---help---
506 Select for the Intel CE media processor (CE4100) SOC.
507 This option compiles in support for the CE4100 SOC for settop
508 boxes and media devices.
509
4cb9b00f 510config X86_INTEL_MID
43605ef1 511 bool "Intel MID platform support"
43605ef1 512 depends on X86_EXTENDED_PLATFORM
edc6bc78 513 depends on X86_PLATFORM_DEVICES
1ea7c673 514 depends on PCI
3fda5bb4 515 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 516 depends on X86_IO_APIC
7c9c3a1e 517 select SFI
4cb9b00f 518 select I2C
7c9c3a1e 519 select DW_APB_TIMER
1ea7c673 520 select APB_TIMER
1ea7c673 521 select INTEL_SCU_IPC
15a713df 522 select MFD_INTEL_MSIC
1ea7c673 523 ---help---
4cb9b00f
DC
524 Select to build a kernel capable of supporting Intel MID (Mobile
525 Internet Device) platform systems which do not have the PCI legacy
526 interfaces. If you are building for a PC class system say N here.
1ea7c673 527
4cb9b00f
DC
528 Intel MID platforms are based on an Intel processor and chipset which
529 consume less power than most of the x86 derivatives.
43605ef1 530
8bbc2a13
BD
531config X86_INTEL_QUARK
532 bool "Intel Quark platform support"
533 depends on X86_32
534 depends on X86_EXTENDED_PLATFORM
535 depends on X86_PLATFORM_DEVICES
536 depends on X86_TSC
537 depends on PCI
538 depends on PCI_GOANY
539 depends on X86_IO_APIC
540 select IOSF_MBI
541 select INTEL_IMR
9ab6eb51 542 select COMMON_CLK
8bbc2a13
BD
543 ---help---
544 Select to include support for Quark X1000 SoC.
545 Say Y here if you have a Quark based system such as the Arduino
546 compatible Intel Galileo.
547
3d48aab1
MW
548config X86_INTEL_LPSS
549 bool "Intel Low Power Subsystem Support"
eebb3e8d 550 depends on X86 && ACPI
3d48aab1 551 select COMMON_CLK
0f531431 552 select PINCTRL
eebb3e8d 553 select IOSF_MBI
3d48aab1
MW
554 ---help---
555 Select to build support for Intel Low Power Subsystem such as
556 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
557 things like clock tree (common clock framework) and pincontrol
558 which are needed by the LPSS peripheral drivers.
3d48aab1 559
92082a88
KX
560config X86_AMD_PLATFORM_DEVICE
561 bool "AMD ACPI2Platform devices support"
562 depends on ACPI
563 select COMMON_CLK
564 select PINCTRL
565 ---help---
566 Select to interpret AMD specific ACPI device to platform device
567 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
568 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
569 implemented under PINCTRL subsystem.
570
ced3ce76
DB
571config IOSF_MBI
572 tristate "Intel SoC IOSF Sideband support for SoC platforms"
573 depends on PCI
574 ---help---
575 This option enables sideband register access support for Intel SoC
576 platforms. On these platforms the IOSF sideband is used in lieu of
577 MSR's for some register accesses, mostly but not limited to thermal
578 and power. Drivers may query the availability of this device to
579 determine if they need the sideband in order to work on these
580 platforms. The sideband is available on the following SoC products.
581 This list is not meant to be exclusive.
582 - BayTrail
583 - Braswell
584 - Quark
585
586 You should say Y if you are running a kernel on one of these SoC's.
587
ed2226bd
DB
588config IOSF_MBI_DEBUG
589 bool "Enable IOSF sideband access through debugfs"
590 depends on IOSF_MBI && DEBUG_FS
591 ---help---
592 Select this option to expose the IOSF sideband access registers (MCR,
593 MDR, MCRX) through debugfs to write and read register information from
594 different units on the SoC. This is most useful for obtaining device
595 state information for debug and analysis. As this is a general access
596 mechanism, users of this option would have specific knowledge of the
597 device they want to access.
598
599 If you don't require the option or are in doubt, say N.
600
c5c606d9
RT
601config X86_RDC321X
602 bool "RDC R-321x SoC"
506f1d07 603 depends on X86_32
c5c606d9
RT
604 depends on X86_EXTENDED_PLATFORM
605 select M486
606 select X86_REBOOTFIXUPS
607 ---help---
608 This option is needed for RDC R-321x system-on-chip, also known
609 as R-8610-(G).
610 If you don't have one of these chips, you should say N here.
611
e0c7ae37 612config X86_32_NON_STANDARD
9c398017
IM
613 bool "Support non-standard 32-bit SMP architectures"
614 depends on X86_32 && SMP
c5c606d9 615 depends on X86_EXTENDED_PLATFORM
8f9ca475 616 ---help---
b5660ba7
PA
617 This option compiles in the bigsmp and STA2X11 default
618 subarchitectures. It is intended for a generic binary
619 kernel. If you select them all, kernel will probe it one by
620 one and will fallback to default.
d49c4288 621
c5c606d9 622# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 623
d949f36f 624config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 625 def_bool y
d949f36f
LT
626 # MCE code calls memory_failure():
627 depends on X86_MCE
628 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
629 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
630 depends on X86_64 || !SPARSEMEM
631 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 632
83125a3a
AR
633config STA2X11
634 bool "STA2X11 Companion Chip Support"
635 depends on X86_32_NON_STANDARD && PCI
636 select X86_DEV_DMA_OPS
637 select X86_DMA_REMAP
638 select SWIOTLB
639 select MFD_STA2X11
640 select ARCH_REQUIRE_GPIOLIB
641 default n
642 ---help---
643 This adds support for boards based on the STA2X11 IO-Hub,
644 a.k.a. "ConneXt". The chip is used in place of the standard
645 PC chipset, so all "standard" peripherals are missing. If this
646 option is selected the kernel will still be able to boot on
647 standard PC machines.
648
82148d1d
S
649config X86_32_IRIS
650 tristate "Eurobraille/Iris poweroff module"
651 depends on X86_32
652 ---help---
653 The Iris machines from EuroBraille do not have APM or ACPI support
654 to shut themselves down properly. A special I/O sequence is
655 needed to do so, which is what this module does at
656 kernel shutdown.
657
658 This is only for Iris machines from EuroBraille.
659
660 If unused, say N.
661
ae1e9130 662config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
663 def_bool y
664 prompt "Single-depth WCHAN output"
a87d0914 665 depends on X86
8f9ca475 666 ---help---
506f1d07
SR
667 Calculate simpler /proc/<PID>/wchan values. If this option
668 is disabled then wchan values will recurse back to the
669 caller function. This provides more accurate wchan values,
670 at the expense of slightly more scheduling overhead.
671
672 If in doubt, say "Y".
673
6276a074
BP
674menuconfig HYPERVISOR_GUEST
675 bool "Linux guest support"
8f9ca475 676 ---help---
6276a074
BP
677 Say Y here to enable options for running Linux under various hyper-
678 visors. This option enables basic hypervisor detection and platform
679 setup.
506f1d07 680
6276a074
BP
681 If you say N, all options in this submenu will be skipped and
682 disabled, and Linux guest support won't be built in.
506f1d07 683
6276a074 684if HYPERVISOR_GUEST
506f1d07 685
e61bd94a
EPH
686config PARAVIRT
687 bool "Enable paravirtualization code"
8f9ca475 688 ---help---
e61bd94a
EPH
689 This changes the kernel so it can modify itself when it is run
690 under a hypervisor, potentially improving performance significantly
691 over full virtualization. However, when run without a hypervisor
692 the kernel is theoretically slower and slightly larger.
693
6276a074
BP
694config PARAVIRT_DEBUG
695 bool "paravirt-ops debugging"
696 depends on PARAVIRT && DEBUG_KERNEL
697 ---help---
698 Enable to debug paravirt_ops internals. Specifically, BUG if
699 a paravirt_op is missing when it is called.
700
b4ecc126
JF
701config PARAVIRT_SPINLOCKS
702 bool "Paravirtualization layer for spinlocks"
6ea30386 703 depends on PARAVIRT && SMP
62c7a1e9 704 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
b4ecc126
JF
705 ---help---
706 Paravirtualized spinlocks allow a pvops backend to replace the
707 spinlock implementation with something virtualization-friendly
708 (for example, block the virtual CPU rather than spinning).
709
4c4e4f61
R
710 It has a minimal impact on native kernels and gives a nice performance
711 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 712
4c4e4f61 713 If you are unsure how to answer this question, answer Y.
b4ecc126 714
45e898b7
WL
715config QUEUED_LOCK_STAT
716 bool "Paravirt queued spinlock statistics"
717 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
718 ---help---
719 Enable the collection of statistical data on the slowpath
720 behavior of paravirtualized queued spinlocks and report
721 them on debugfs.
722
6276a074 723source "arch/x86/xen/Kconfig"
7af192c9 724
6276a074
BP
725config KVM_GUEST
726 bool "KVM Guest support (including kvmclock)"
727 depends on PARAVIRT
728 select PARAVIRT_CLOCK
729 default y
8f9ca475 730 ---help---
6276a074
BP
731 This option enables various optimizations for running under the KVM
732 hypervisor. It includes a paravirtualized clock, so that instead
733 of relying on a PIT (or probably other) emulation by the
734 underlying device model, the host provides the guest with
735 timing infrastructure such as time of day, and system time
506f1d07 736
1e20eb85
SV
737config KVM_DEBUG_FS
738 bool "Enable debug information for KVM Guests in debugfs"
739 depends on KVM_GUEST && DEBUG_FS
740 default n
741 ---help---
742 This option enables collection of various statistics for KVM guest.
743 Statistics are displayed in debugfs filesystem. Enabling this option
744 may incur significant overhead.
745
6276a074
BP
746source "arch/x86/lguest/Kconfig"
747
748config PARAVIRT_TIME_ACCOUNTING
749 bool "Paravirtual steal time accounting"
750 depends on PARAVIRT
751 default n
8f9ca475 752 ---help---
6276a074
BP
753 Select this option to enable fine granularity task steal time
754 accounting. Time spent executing other tasks in parallel with
755 the current vCPU is discounted from the vCPU power. To account for
756 that, there can be a small performance impact.
757
758 If in doubt, say N here.
759
760config PARAVIRT_CLOCK
761 bool
97349135 762
6276a074 763endif #HYPERVISOR_GUEST
97349135 764
08677214 765config NO_BOOTMEM
774ea0bc 766 def_bool y
08677214 767
506f1d07
SR
768source "arch/x86/Kconfig.cpu"
769
770config HPET_TIMER
3c2362e6 771 def_bool X86_64
506f1d07 772 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
773 ---help---
774 Use the IA-PC HPET (High Precision Event Timer) to manage
775 time in preference to the PIT and RTC, if a HPET is
776 present.
777 HPET is the next generation timer replacing legacy 8254s.
778 The HPET provides a stable time base on SMP
779 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
780 as it is off-chip. The interface used is documented
781 in the HPET spec, revision 1.
506f1d07 782
8f9ca475
IM
783 You can safely choose Y here. However, HPET will only be
784 activated if the platform and the BIOS support this feature.
785 Otherwise the 8254 will be used for timing services.
506f1d07 786
8f9ca475 787 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
788
789config HPET_EMULATE_RTC
3c2362e6 790 def_bool y
9d8af78b 791 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 792
bb24c471 793config APB_TIMER
933b9463
AC
794 def_bool y if X86_INTEL_MID
795 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 796 select DW_APB_TIMER
a0c3832a 797 depends on X86_INTEL_MID && SFI
bb24c471
JP
798 help
799 APB timer is the replacement for 8254, HPET on X86 MID platforms.
800 The APBT provides a stable time base on SMP
801 systems, unlike the TSC, but it is more expensive to access,
802 as it is off-chip. APB timers are always running regardless of CPU
803 C states, they are used as per CPU clockevent device when possible.
804
6a108a14 805# Mark as expert because too many people got it wrong.
506f1d07 806# The code disables itself when not needed.
7ae9392c
TP
807config DMI
808 default y
cf074402 809 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 810 bool "Enable DMI scanning" if EXPERT
8f9ca475 811 ---help---
7ae9392c
TP
812 Enabled scanning of DMI to identify machine quirks. Say Y
813 here unless you have verified that your setup is not
814 affected by entries in the DMI blacklist. Required by PNP
815 BIOS code.
816
506f1d07 817config GART_IOMMU
38901f1c 818 bool "Old AMD GART IOMMU support"
506f1d07 819 select SWIOTLB
23ac4ae8 820 depends on X86_64 && PCI && AMD_NB
8f9ca475 821 ---help---
ced3c42c
IM
822 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
823 GART based hardware IOMMUs.
824
825 The GART supports full DMA access for devices with 32-bit access
826 limitations, on systems with more than 3 GB. This is usually needed
827 for USB, sound, many IDE/SATA chipsets and some other devices.
828
829 Newer systems typically have a modern AMD IOMMU, supported via
830 the CONFIG_AMD_IOMMU=y config option.
831
832 In normal configurations this driver is only active when needed:
833 there's more than 3 GB of memory and the system contains a
834 32-bit limited device.
835
836 If unsure, say Y.
506f1d07
SR
837
838config CALGARY_IOMMU
839 bool "IBM Calgary IOMMU support"
840 select SWIOTLB
6ea30386 841 depends on X86_64 && PCI
8f9ca475 842 ---help---
506f1d07
SR
843 Support for hardware IOMMUs in IBM's xSeries x366 and x460
844 systems. Needed to run systems with more than 3GB of memory
845 properly with 32-bit PCI devices that do not support DAC
846 (Double Address Cycle). Calgary also supports bus level
847 isolation, where all DMAs pass through the IOMMU. This
848 prevents them from going anywhere except their intended
849 destination. This catches hard-to-find kernel bugs and
850 mis-behaving drivers and devices that do not use the DMA-API
851 properly to set up their DMA buffers. The IOMMU can be
852 turned off at boot time with the iommu=off parameter.
853 Normally the kernel will make the right choice by itself.
854 If unsure, say Y.
855
856config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
857 def_bool y
858 prompt "Should Calgary be enabled by default?"
506f1d07 859 depends on CALGARY_IOMMU
8f9ca475 860 ---help---
506f1d07
SR
861 Should Calgary be enabled by default? if you choose 'y', Calgary
862 will be used (if it exists). If you choose 'n', Calgary will not be
863 used even if it exists. If you choose 'n' and would like to use
864 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
865 If unsure, say Y.
866
867# need this always selected by IOMMU for the VIA workaround
868config SWIOTLB
a1afd01c 869 def_bool y if X86_64
8f9ca475 870 ---help---
506f1d07 871 Support for software bounce buffers used on x86-64 systems
4454d327
JM
872 which don't have a hardware IOMMU. Using this PCI devices
873 which can only access 32-bits of memory can be used on systems
874 with more than 3 GB of memory.
875 If unsure, say Y.
506f1d07 876
a8522509 877config IOMMU_HELPER
3120e25e
JB
878 def_bool y
879 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 880
1184dc2f 881config MAXSMP
ddb0c5a6 882 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 883 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 884 select CPUMASK_OFFSTACK
8f9ca475 885 ---help---
ddb0c5a6 886 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 887 If unsure, say N.
506f1d07
SR
888
889config NR_CPUS
36f5101a 890 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 891 range 2 8 if SMP && X86_32 && !X86_BIGSMP
bb61ccc7 892 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
b53b5eda 893 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 894 default "1" if !SMP
b53b5eda 895 default "8192" if MAXSMP
b5660ba7 896 default "32" if SMP && X86_BIGSMP
c5c19941
KS
897 default "8" if SMP && X86_32
898 default "64" if SMP
8f9ca475 899 ---help---
506f1d07 900 This allows you to specify the maximum number of CPUs which this
bb61ccc7 901 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 902 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
903 minimum value which makes sense is 2.
904
905 This is purely to save memory - each supported CPU adds
906 approximately eight kilobytes to the kernel image.
907
908config SCHED_SMT
909 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 910 depends on SMP
8f9ca475 911 ---help---
506f1d07
SR
912 SMT scheduler support improves the CPU scheduler's decision making
913 when dealing with Intel Pentium 4 chips with HyperThreading at a
914 cost of slightly increased overhead in some places. If unsure say
915 N here.
916
917config SCHED_MC
3c2362e6
HH
918 def_bool y
919 prompt "Multi-core scheduler support"
c8e56d20 920 depends on SMP
8f9ca475 921 ---help---
506f1d07
SR
922 Multi-core scheduler support improves the CPU scheduler's decision
923 making when dealing with multi-core CPU chips at a cost of slightly
924 increased overhead in some places. If unsure say N here.
925
926source "kernel/Kconfig.preempt"
927
30b8b006
TG
928config UP_LATE_INIT
929 def_bool y
ba360f88 930 depends on !SMP && X86_LOCAL_APIC
30b8b006 931
506f1d07 932config X86_UP_APIC
50849eef
JB
933 bool "Local APIC support on uniprocessors" if !PCI_MSI
934 default PCI_MSI
38a1dfda 935 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 936 ---help---
506f1d07
SR
937 A local APIC (Advanced Programmable Interrupt Controller) is an
938 integrated interrupt controller in the CPU. If you have a single-CPU
939 system which has a processor with a local APIC, you can say Y here to
940 enable and use it. If you say Y here even though your machine doesn't
941 have a local APIC, then the kernel will still run with no slowdown at
942 all. The local APIC supports CPU-generated self-interrupts (timer,
943 performance counters), and the NMI watchdog which detects hard
944 lockups.
945
946config X86_UP_IOAPIC
947 bool "IO-APIC support on uniprocessors"
948 depends on X86_UP_APIC
8f9ca475 949 ---help---
506f1d07
SR
950 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
951 SMP-capable replacement for PC-style interrupt controllers. Most
952 SMP systems and many recent uniprocessor systems have one.
953
954 If you have a single-CPU system with an IO-APIC, you can say Y here
955 to use it. If you say Y here even though your machine doesn't have
956 an IO-APIC, then the kernel will still run with no slowdown at all.
957
958config X86_LOCAL_APIC
3c2362e6 959 def_bool y
0dbc6078 960 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 961 select IRQ_DOMAIN_HIERARCHY
52f518a3 962 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
963
964config X86_IO_APIC
b1da1e71
JB
965 def_bool y
966 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 967
41b9eb26
SA
968config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
969 bool "Reroute for broken boot IRQs"
41b9eb26 970 depends on X86_IO_APIC
8f9ca475 971 ---help---
41b9eb26
SA
972 This option enables a workaround that fixes a source of
973 spurious interrupts. This is recommended when threaded
974 interrupt handling is used on systems where the generation of
975 superfluous "boot interrupts" cannot be disabled.
976
977 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
978 entry in the chipset's IO-APIC is masked (as, e.g. the RT
979 kernel does during interrupt handling). On chipsets where this
980 boot IRQ generation cannot be disabled, this workaround keeps
981 the original IRQ line masked so that only the equivalent "boot
982 IRQ" is delivered to the CPUs. The workaround also tells the
983 kernel to set up the IRQ handler on the boot IRQ line. In this
984 way only one interrupt is delivered to the kernel. Otherwise
985 the spurious second interrupt may cause the kernel to bring
986 down (vital) interrupt lines.
987
988 Only affects "broken" chipsets. Interrupt sharing may be
989 increased on these systems.
990
506f1d07 991config X86_MCE
bab9bc65 992 bool "Machine Check / overheating reporting"
648ed940 993 select GENERIC_ALLOCATOR
e57dbaf7 994 default y
506f1d07 995 ---help---
bab9bc65
AK
996 Machine Check support allows the processor to notify the
997 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 998 The action the kernel takes depends on the severity of the problem,
bab9bc65 999 ranging from warning messages to halting the machine.
4efc0670 1000
506f1d07 1001config X86_MCE_INTEL
3c2362e6
HH
1002 def_bool y
1003 prompt "Intel MCE features"
c1ebf835 1004 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1005 ---help---
506f1d07
SR
1006 Additional support for intel specific MCE features such as
1007 the thermal monitor.
1008
1009config X86_MCE_AMD
3c2362e6
HH
1010 def_bool y
1011 prompt "AMD MCE features"
c1ebf835 1012 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1013 ---help---
506f1d07
SR
1014 Additional support for AMD specific MCE features such as
1015 the DRAM Error Threshold.
1016
4efc0670 1017config X86_ANCIENT_MCE
6fc108a0 1018 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1019 depends on X86_32 && X86_MCE
cd13adcc
HS
1020 ---help---
1021 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1022 systems. These typically need to be enabled explicitly on the command
cd13adcc 1023 line.
4efc0670 1024
b2762686
AK
1025config X86_MCE_THRESHOLD
1026 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1027 def_bool y
b2762686 1028
ea149b36 1029config X86_MCE_INJECT
c1ebf835 1030 depends on X86_MCE
ea149b36
AK
1031 tristate "Machine check injector support"
1032 ---help---
1033 Provide support for injecting machine checks for testing purposes.
1034 If you don't know what a machine check is and you don't do kernel
1035 QA it is safe to say n.
1036
4efc0670
AK
1037config X86_THERMAL_VECTOR
1038 def_bool y
5bb38adc 1039 depends on X86_MCE_INTEL
4efc0670 1040
e633c65a
KL
1041source "arch/x86/Kconfig.perf"
1042
5aef51c3 1043config X86_LEGACY_VM86
1e642812 1044 bool "Legacy VM86 support"
5aef51c3 1045 default n
506f1d07 1046 depends on X86_32
8f9ca475 1047 ---help---
5aef51c3
AL
1048 This option allows user programs to put the CPU into V8086
1049 mode, which is an 80286-era approximation of 16-bit real mode.
1050
1051 Some very old versions of X and/or vbetool require this option
1052 for user mode setting. Similarly, DOSEMU will use it if
1053 available to accelerate real mode DOS programs. However, any
1054 recent version of DOSEMU, X, or vbetool should be fully
1055 functional even without kernel VM86 support, as they will all
1e642812
IM
1056 fall back to software emulation. Nevertheless, if you are using
1057 a 16-bit DOS program where 16-bit performance matters, vm86
1058 mode might be faster than emulation and you might want to
1059 enable this option.
5aef51c3 1060
1e642812
IM
1061 Note that any app that works on a 64-bit kernel is unlikely to
1062 need this option, as 64-bit kernels don't, and can't, support
1063 V8086 mode. This option is also unrelated to 16-bit protected
1064 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1065
1e642812
IM
1066 Enabling this option increases the complexity of the kernel
1067 and slows down exception handling a tiny bit.
5aef51c3 1068
1e642812 1069 If unsure, say N here.
5aef51c3
AL
1070
1071config VM86
1072 bool
1073 default X86_LEGACY_VM86
34273f41
PA
1074
1075config X86_16BIT
1076 bool "Enable support for 16-bit segments" if EXPERT
1077 default y
a5b9e5a2 1078 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1079 ---help---
1080 This option is required by programs like Wine to run 16-bit
1081 protected mode legacy code on x86 processors. Disabling
1082 this option saves about 300 bytes on i386, or around 6K text
1083 plus 16K runtime memory on x86-64,
1084
1085config X86_ESPFIX32
1086 def_bool y
1087 depends on X86_16BIT && X86_32
506f1d07 1088
197725de
PA
1089config X86_ESPFIX64
1090 def_bool y
34273f41 1091 depends on X86_16BIT && X86_64
506f1d07 1092
1ad83c85
AL
1093config X86_VSYSCALL_EMULATION
1094 bool "Enable vsyscall emulation" if EXPERT
1095 default y
1096 depends on X86_64
1097 ---help---
1098 This enables emulation of the legacy vsyscall page. Disabling
1099 it is roughly equivalent to booting with vsyscall=none, except
1100 that it will also disable the helpful warning if a program
1101 tries to use a vsyscall. With this option set to N, offending
1102 programs will just segfault, citing addresses of the form
1103 0xffffffffff600?00.
1104
1105 This option is required by many programs built before 2013, and
1106 care should be used even with newer programs if set to N.
1107
1108 Disabling this option saves about 7K of kernel size and
1109 possibly 4K of additional runtime pagetable memory.
1110
506f1d07
SR
1111config TOSHIBA
1112 tristate "Toshiba Laptop support"
1113 depends on X86_32
1114 ---help---
1115 This adds a driver to safely access the System Management Mode of
1116 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1117 not work on models with a Phoenix BIOS. The System Management Mode
1118 is used to set the BIOS and power saving options on Toshiba portables.
1119
1120 For information on utilities to make use of this driver see the
1121 Toshiba Linux utilities web site at:
1122 <http://www.buzzard.org.uk/toshiba/>.
1123
1124 Say Y if you intend to run this kernel on a Toshiba portable.
1125 Say N otherwise.
1126
1127config I8K
039ae585 1128 tristate "Dell i8k legacy laptop support"
949a9d70 1129 select HWMON
039ae585 1130 select SENSORS_DELL_SMM
506f1d07 1131 ---help---
039ae585
PR
1132 This option enables legacy /proc/i8k userspace interface in hwmon
1133 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1134 temperature and allows controlling fan speeds of Dell laptops via
1135 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1136 it reports also power and hotkey status. For fan speed control is
1137 needed userspace package i8kutils.
1138
1139 Say Y if you intend to run this kernel on old Dell laptops or want to
1140 use userspace package i8kutils.
506f1d07
SR
1141 Say N otherwise.
1142
1143config X86_REBOOTFIXUPS
9ba16087
JB
1144 bool "Enable X86 board specific fixups for reboot"
1145 depends on X86_32
506f1d07
SR
1146 ---help---
1147 This enables chipset and/or board specific fixups to be done
1148 in order to get reboot to work correctly. This is only needed on
1149 some combinations of hardware and BIOS. The symptom, for which
1150 this config is intended, is when reboot ends with a stalled/hung
1151 system.
1152
1153 Currently, the only fixup is for the Geode machines using
5e3a77e9 1154 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1155
1156 Say Y if you want to enable the fixup. Currently, it's safe to
1157 enable this option even if you don't need it.
1158 Say N otherwise.
1159
1160config MICROCODE
9a2bc335
BP
1161 bool "CPU microcode loading support"
1162 default y
80030e3d 1163 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1164 select FW_LOADER
1165 ---help---
1166 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1167 Intel and AMD processors. The Intel support is for the IA32 family,
1168 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1169 AMD support is for families 0x10 and later. You will obviously need
1170 the actual microcode binary data itself which is not shipped with
1171 the Linux kernel.
1172
1173 The preferred method to load microcode from a detached initrd is described
1174 in Documentation/x86/early-microcode.txt. For that you need to enable
1175 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1176 initrd for microcode blobs.
1177
1178 In addition, you can build-in the microcode into the kernel. For that you
1179 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1180 to the CONFIG_EXTRA_FIRMWARE config option.
506f1d07 1181
8d86f390 1182config MICROCODE_INTEL
e43f6e67 1183 bool "Intel microcode loading support"
8f9ca475
IM
1184 depends on MICROCODE
1185 default MICROCODE
1186 select FW_LOADER
1187 ---help---
1188 This options enables microcode patch loading support for Intel
1189 processors.
1190
b8989db9
A
1191 For the current Intel microcode data package go to
1192 <https://downloadcenter.intel.com> and search for
1193 'Linux Processor Microcode Data File'.
8d86f390 1194
80cc9f10 1195config MICROCODE_AMD
e43f6e67 1196 bool "AMD microcode loading support"
8f9ca475
IM
1197 depends on MICROCODE
1198 select FW_LOADER
1199 ---help---
1200 If you select this option, microcode patch loading support for AMD
1201 processors will be enabled.
80cc9f10 1202
8f9ca475 1203config MICROCODE_OLD_INTERFACE
3c2362e6 1204 def_bool y
506f1d07 1205 depends on MICROCODE
506f1d07 1206
c7ab62bf
HR
1207config PERF_EVENTS_AMD_POWER
1208 depends on PERF_EVENTS && CPU_SUP_AMD
1209 tristate "AMD Processor Power Reporting Mechanism"
1210 ---help---
1211 Provide power reporting mechanism support for AMD processors.
1212 Currently, it leverages X86_FEATURE_ACC_POWER
1213 (CPUID Fn8000_0007_EDX[12]) interface to calculate the
1214 average power consumption on Family 15h processors.
1215
506f1d07
SR
1216config X86_MSR
1217 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1218 ---help---
506f1d07
SR
1219 This device gives privileged processes access to the x86
1220 Model-Specific Registers (MSRs). It is a character device with
1221 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1222 MSR accesses are directed to a specific CPU on multi-processor
1223 systems.
1224
1225config X86_CPUID
1226 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1227 ---help---
506f1d07
SR
1228 This device gives processes access to the x86 CPUID instruction to
1229 be executed on a specific processor. It is a character device
1230 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1231 /dev/cpu/31/cpuid.
1232
1233choice
1234 prompt "High Memory Support"
6fc108a0 1235 default HIGHMEM4G
506f1d07
SR
1236 depends on X86_32
1237
1238config NOHIGHMEM
1239 bool "off"
506f1d07
SR
1240 ---help---
1241 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1242 However, the address space of 32-bit x86 processors is only 4
1243 Gigabytes large. That means that, if you have a large amount of
1244 physical memory, not all of it can be "permanently mapped" by the
1245 kernel. The physical memory that's not permanently mapped is called
1246 "high memory".
1247
1248 If you are compiling a kernel which will never run on a machine with
1249 more than 1 Gigabyte total physical RAM, answer "off" here (default
1250 choice and suitable for most users). This will result in a "3GB/1GB"
1251 split: 3GB are mapped so that each process sees a 3GB virtual memory
1252 space and the remaining part of the 4GB virtual memory space is used
1253 by the kernel to permanently map as much physical memory as
1254 possible.
1255
1256 If the machine has between 1 and 4 Gigabytes physical RAM, then
1257 answer "4GB" here.
1258
1259 If more than 4 Gigabytes is used then answer "64GB" here. This
1260 selection turns Intel PAE (Physical Address Extension) mode on.
1261 PAE implements 3-level paging on IA32 processors. PAE is fully
1262 supported by Linux, PAE mode is implemented on all recent Intel
1263 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1264 then the kernel will not boot on CPUs that don't support PAE!
1265
1266 The actual amount of total physical memory will either be
1267 auto detected or can be forced by using a kernel command line option
1268 such as "mem=256M". (Try "man bootparam" or see the documentation of
1269 your boot loader (lilo or loadlin) about how to pass options to the
1270 kernel at boot time.)
1271
1272 If unsure, say "off".
1273
1274config HIGHMEM4G
1275 bool "4GB"
8f9ca475 1276 ---help---
506f1d07
SR
1277 Select this if you have a 32-bit processor and between 1 and 4
1278 gigabytes of physical RAM.
1279
1280config HIGHMEM64G
1281 bool "64GB"
eb068e78 1282 depends on !M486
506f1d07 1283 select X86_PAE
8f9ca475 1284 ---help---
506f1d07
SR
1285 Select this if you have a 32-bit processor and more than 4
1286 gigabytes of physical RAM.
1287
1288endchoice
1289
1290choice
6a108a14 1291 prompt "Memory split" if EXPERT
506f1d07
SR
1292 default VMSPLIT_3G
1293 depends on X86_32
8f9ca475 1294 ---help---
506f1d07
SR
1295 Select the desired split between kernel and user memory.
1296
1297 If the address range available to the kernel is less than the
1298 physical memory installed, the remaining memory will be available
1299 as "high memory". Accessing high memory is a little more costly
1300 than low memory, as it needs to be mapped into the kernel first.
1301 Note that increasing the kernel address space limits the range
1302 available to user programs, making the address space there
1303 tighter. Selecting anything other than the default 3G/1G split
1304 will also likely make your kernel incompatible with binary-only
1305 kernel modules.
1306
1307 If you are not absolutely sure what you are doing, leave this
1308 option alone!
1309
1310 config VMSPLIT_3G
1311 bool "3G/1G user/kernel split"
1312 config VMSPLIT_3G_OPT
1313 depends on !X86_PAE
1314 bool "3G/1G user/kernel split (for full 1G low memory)"
1315 config VMSPLIT_2G
1316 bool "2G/2G user/kernel split"
1317 config VMSPLIT_2G_OPT
1318 depends on !X86_PAE
1319 bool "2G/2G user/kernel split (for full 2G low memory)"
1320 config VMSPLIT_1G
1321 bool "1G/3G user/kernel split"
1322endchoice
1323
1324config PAGE_OFFSET
1325 hex
1326 default 0xB0000000 if VMSPLIT_3G_OPT
1327 default 0x80000000 if VMSPLIT_2G
1328 default 0x78000000 if VMSPLIT_2G_OPT
1329 default 0x40000000 if VMSPLIT_1G
1330 default 0xC0000000
1331 depends on X86_32
1332
1333config HIGHMEM
3c2362e6 1334 def_bool y
506f1d07 1335 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1336
1337config X86_PAE
9ba16087 1338 bool "PAE (Physical Address Extension) Support"
506f1d07 1339 depends on X86_32 && !HIGHMEM4G
9d99c712 1340 select SWIOTLB
8f9ca475 1341 ---help---
506f1d07
SR
1342 PAE is required for NX support, and furthermore enables
1343 larger swapspace support for non-overcommit purposes. It
1344 has the cost of more pagetable lookup overhead, and also
1345 consumes more pagetable space per process.
1346
600715dc 1347config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1348 def_bool y
1349 depends on X86_64 || X86_PAE
600715dc 1350
66f2b061 1351config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1352 def_bool y
1353 depends on X86_64 || HIGHMEM64G
66f2b061 1354
10971ab2 1355config X86_DIRECT_GBPAGES
e5008abe
LR
1356 def_bool y
1357 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
8f9ca475 1358 ---help---
10971ab2
IM
1359 Certain kernel features effectively disable kernel
1360 linear 1 GB mappings (even if the CPU otherwise
1361 supports them), so don't confuse the user by printing
1362 that we have them enabled.
9e899816 1363
506f1d07
SR
1364# Common NUMA Features
1365config NUMA
fd51b2d7 1366 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1367 depends on SMP
b5660ba7
PA
1368 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1369 default y if X86_BIGSMP
8f9ca475 1370 ---help---
506f1d07 1371 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1372
506f1d07
SR
1373 The kernel will try to allocate memory used by a CPU on the
1374 local memory controller of the CPU and add some more
1375 NUMA awareness to the kernel.
1376
c280ea5e 1377 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1378 (or later), AMD Opteron, or EM64T NUMA.
1379
b5660ba7 1380 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1381 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1382
1383 Otherwise, you should say N.
506f1d07 1384
eec1d4fa 1385config AMD_NUMA
3c2362e6
HH
1386 def_bool y
1387 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1388 depends on X86_64 && NUMA && PCI
8f9ca475 1389 ---help---
eec1d4fa
HR
1390 Enable AMD NUMA node topology detection. You should say Y here if
1391 you have a multi processor AMD system. This uses an old method to
1392 read the NUMA configuration directly from the builtin Northbridge
1393 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1394 which also takes priority if both are compiled in.
506f1d07
SR
1395
1396config X86_64_ACPI_NUMA
3c2362e6
HH
1397 def_bool y
1398 prompt "ACPI NUMA detection"
506f1d07
SR
1399 depends on X86_64 && NUMA && ACPI && PCI
1400 select ACPI_NUMA
8f9ca475 1401 ---help---
506f1d07
SR
1402 Enable ACPI SRAT based node topology detection.
1403
6ec6e0d9
SS
1404# Some NUMA nodes have memory ranges that span
1405# other nodes. Even though a pfn is valid and
1406# between a node's start and end pfns, it may not
1407# reside on that node. See memmap_init_zone()
1408# for details.
1409config NODES_SPAN_OTHER_NODES
1410 def_bool y
1411 depends on X86_64_ACPI_NUMA
1412
506f1d07
SR
1413config NUMA_EMU
1414 bool "NUMA emulation"
1b7e03ef 1415 depends on NUMA
8f9ca475 1416 ---help---
506f1d07
SR
1417 Enable NUMA emulation. A flat machine will be split
1418 into virtual nodes when booted with "numa=fake=N", where N is the
1419 number of nodes. This is only useful for debugging.
1420
1421config NODES_SHIFT
d25e26b6 1422 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1423 range 1 10
1424 default "10" if MAXSMP
506f1d07 1425 default "6" if X86_64
506f1d07
SR
1426 default "3"
1427 depends on NEED_MULTIPLE_NODES
8f9ca475 1428 ---help---
1184dc2f 1429 Specify the maximum number of NUMA Nodes available on the target
692105b8 1430 system. Increases memory reserved to accommodate various tables.
506f1d07 1431
506f1d07 1432config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1433 def_bool y
506f1d07 1434 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1435
1436config NEED_NODE_MEMMAP_SIZE
3c2362e6 1437 def_bool y
506f1d07 1438 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1439
506f1d07
SR
1440config ARCH_FLATMEM_ENABLE
1441 def_bool y
3b16651f 1442 depends on X86_32 && !NUMA
506f1d07
SR
1443
1444config ARCH_DISCONTIGMEM_ENABLE
1445 def_bool y
b263295d 1446 depends on NUMA && X86_32
506f1d07
SR
1447
1448config ARCH_DISCONTIGMEM_DEFAULT
1449 def_bool y
b263295d
CL
1450 depends on NUMA && X86_32
1451
506f1d07
SR
1452config ARCH_SPARSEMEM_ENABLE
1453 def_bool y
6ea30386 1454 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1455 select SPARSEMEM_STATIC if X86_32
1456 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1457
3b16651f
TH
1458config ARCH_SPARSEMEM_DEFAULT
1459 def_bool y
1460 depends on X86_64
1461
506f1d07
SR
1462config ARCH_SELECT_MEMORY_MODEL
1463 def_bool y
b263295d 1464 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1465
1466config ARCH_MEMORY_PROBE
a0842b70 1467 bool "Enable sysfs memory/probe interface"
3120e25e 1468 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1469 help
1470 This option enables a sysfs memory/probe interface for testing.
1471 See Documentation/memory-hotplug.txt for more information.
1472 If you are unsure how to answer this question, answer N.
506f1d07 1473
3b16651f
TH
1474config ARCH_PROC_KCORE_TEXT
1475 def_bool y
1476 depends on X86_64 && PROC_KCORE
1477
a29815a3
AK
1478config ILLEGAL_POINTER_VALUE
1479 hex
1480 default 0 if X86_32
1481 default 0xdead000000000000 if X86_64
1482
506f1d07
SR
1483source "mm/Kconfig"
1484
7a67832c
DW
1485config X86_PMEM_LEGACY_DEVICE
1486 bool
1487
ec776ef6 1488config X86_PMEM_LEGACY
7a67832c 1489 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1490 depends on PHYS_ADDR_T_64BIT
1491 depends on BLK_DEV
7a67832c 1492 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1493 select LIBNVDIMM
ec776ef6
CH
1494 help
1495 Treat memory marked using the non-standard e820 type of 12 as used
1496 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1497 The kernel will offer these regions to the 'pmem' driver so
1498 they can be used for persistent storage.
1499
1500 Say Y if unsure.
1501
506f1d07
SR
1502config HIGHPTE
1503 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1504 depends on HIGHMEM
8f9ca475 1505 ---help---
506f1d07
SR
1506 The VM uses one page table entry for each page of physical memory.
1507 For systems with a lot of RAM, this can be wasteful of precious
1508 low memory. Setting this option will put user-space page table
1509 entries in high memory.
1510
9f077871 1511config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1512 bool "Check for low memory corruption"
1513 ---help---
1514 Periodically check for memory corruption in low memory, which
1515 is suspected to be caused by BIOS. Even when enabled in the
1516 configuration, it is disabled at runtime. Enable it by
1517 setting "memory_corruption_check=1" on the kernel command
1518 line. By default it scans the low 64k of memory every 60
1519 seconds; see the memory_corruption_check_size and
1520 memory_corruption_check_period parameters in
1521 Documentation/kernel-parameters.txt to adjust this.
1522
1523 When enabled with the default parameters, this option has
1524 almost no overhead, as it reserves a relatively small amount
1525 of memory and scans it infrequently. It both detects corruption
1526 and prevents it from affecting the running system.
1527
1528 It is, however, intended as a diagnostic tool; if repeatable
1529 BIOS-originated corruption always affects the same memory,
1530 you can use memmap= to prevent the kernel from using that
1531 memory.
9f077871 1532
c885df50 1533config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1534 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1535 depends on X86_CHECK_BIOS_CORRUPTION
1536 default y
8f9ca475
IM
1537 ---help---
1538 Set whether the default state of memory_corruption_check is
1539 on or off.
c885df50 1540
9ea77bdb 1541config X86_RESERVE_LOW
d0cd7425
PA
1542 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1543 default 64
1544 range 4 640
8f9ca475 1545 ---help---
d0cd7425
PA
1546 Specify the amount of low memory to reserve for the BIOS.
1547
1548 The first page contains BIOS data structures that the kernel
1549 must not use, so that page must always be reserved.
1550
1551 By default we reserve the first 64K of physical RAM, as a
1552 number of BIOSes are known to corrupt that memory range
1553 during events such as suspend/resume or monitor cable
1554 insertion, so it must not be used by the kernel.
fc381519 1555
d0cd7425
PA
1556 You can set this to 4 if you are absolutely sure that you
1557 trust the BIOS to get all its memory reservations and usages
1558 right. If you know your BIOS have problems beyond the
1559 default 64K area, you can set this to 640 to avoid using the
1560 entire low memory range.
fc381519 1561
d0cd7425
PA
1562 If you have doubts about the BIOS (e.g. suspend/resume does
1563 not work or there's kernel crashes after certain hardware
1564 hotplug events) then you might want to enable
1565 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1566 typical corruption patterns.
fc381519 1567
d0cd7425 1568 Leave this to the default value of 64 if you are unsure.
fc381519 1569
506f1d07
SR
1570config MATH_EMULATION
1571 bool
a5b9e5a2 1572 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1573 prompt "Math emulation" if X86_32
1574 ---help---
1575 Linux can emulate a math coprocessor (used for floating point
1576 operations) if you don't have one. 486DX and Pentium processors have
1577 a math coprocessor built in, 486SX and 386 do not, unless you added
1578 a 487DX or 387, respectively. (The messages during boot time can
1579 give you some hints here ["man dmesg"].) Everyone needs either a
1580 coprocessor or this emulation.
1581
1582 If you don't have a math coprocessor, you need to say Y here; if you
1583 say Y here even though you have a coprocessor, the coprocessor will
1584 be used nevertheless. (This behavior can be changed with the kernel
1585 command line option "no387", which comes handy if your coprocessor
1586 is broken. Try "man bootparam" or see the documentation of your boot
1587 loader (lilo or loadlin) about how to pass options to the kernel at
1588 boot time.) This means that it is a good idea to say Y here if you
1589 intend to use this kernel on different machines.
1590
1591 More information about the internals of the Linux math coprocessor
1592 emulation can be found in <file:arch/x86/math-emu/README>.
1593
1594 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1595 kernel, it won't hurt.
1596
1597config MTRR
6fc108a0 1598 def_bool y
6a108a14 1599 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1600 ---help---
1601 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1602 the Memory Type Range Registers (MTRRs) may be used to control
1603 processor access to memory ranges. This is most useful if you have
1604 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1605 allows bus write transfers to be combined into a larger transfer
1606 before bursting over the PCI/AGP bus. This can increase performance
1607 of image write operations 2.5 times or more. Saying Y here creates a
1608 /proc/mtrr file which may be used to manipulate your processor's
1609 MTRRs. Typically the X server should use this.
1610
1611 This code has a reasonably generic interface so that similar
1612 control registers on other processors can be easily supported
1613 as well:
1614
1615 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1616 Registers (ARRs) which provide a similar functionality to MTRRs. For
1617 these, the ARRs are used to emulate the MTRRs.
1618 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1619 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1620 write-combining. All of these processors are supported by this code
1621 and it makes sense to say Y here if you have one of them.
1622
1623 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1624 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1625 can lead to all sorts of problems, so it's good to say Y here.
1626
1627 You can safely say Y even if your machine doesn't have MTRRs, you'll
1628 just add about 9 KB to your kernel.
1629
7225e751 1630 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1631
95ffa243 1632config MTRR_SANITIZER
2ffb3501 1633 def_bool y
95ffa243
YL
1634 prompt "MTRR cleanup support"
1635 depends on MTRR
8f9ca475 1636 ---help---
aba3728c
TG
1637 Convert MTRR layout from continuous to discrete, so X drivers can
1638 add writeback entries.
95ffa243 1639
aba3728c 1640 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1641 The largest mtrr entry size for a continuous block can be set with
aba3728c 1642 mtrr_chunk_size.
95ffa243 1643
2ffb3501 1644 If unsure, say Y.
95ffa243
YL
1645
1646config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1647 int "MTRR cleanup enable value (0-1)"
1648 range 0 1
1649 default "0"
95ffa243 1650 depends on MTRR_SANITIZER
8f9ca475 1651 ---help---
f5098d62 1652 Enable mtrr cleanup default value
95ffa243 1653
12031a62
YL
1654config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1655 int "MTRR cleanup spare reg num (0-7)"
1656 range 0 7
1657 default "1"
1658 depends on MTRR_SANITIZER
8f9ca475 1659 ---help---
12031a62 1660 mtrr cleanup spare entries default, it can be changed via
aba3728c 1661 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1662
2e5d9c85 1663config X86_PAT
6fc108a0 1664 def_bool y
6a108a14 1665 prompt "x86 PAT support" if EXPERT
2a8a2719 1666 depends on MTRR
8f9ca475 1667 ---help---
2e5d9c85 1668 Use PAT attributes to setup page level cache control.
042b78e4 1669
2e5d9c85 1670 PATs are the modern equivalents of MTRRs and are much more
1671 flexible than MTRRs.
1672
1673 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1674 spontaneous reboots) or a non-working video driver.
2e5d9c85 1675
1676 If unsure, say Y.
1677
46cf98cd
VP
1678config ARCH_USES_PG_UNCACHED
1679 def_bool y
1680 depends on X86_PAT
1681
628c6246
PA
1682config ARCH_RANDOM
1683 def_bool y
1684 prompt "x86 architectural random number generator" if EXPERT
1685 ---help---
1686 Enable the x86 architectural RDRAND instruction
1687 (Intel Bull Mountain technology) to generate random numbers.
1688 If supported, this is a high bandwidth, cryptographically
1689 secure hardware random number generator.
1690
51ae4a2d
PA
1691config X86_SMAP
1692 def_bool y
1693 prompt "Supervisor Mode Access Prevention" if EXPERT
1694 ---help---
1695 Supervisor Mode Access Prevention (SMAP) is a security
1696 feature in newer Intel processors. There is a small
1697 performance cost if this enabled and turned on; there is
1698 also a small increase in the kernel size if this is enabled.
1699
1700 If unsure, say Y.
1701
72e9b5fe
DH
1702config X86_INTEL_MPX
1703 prompt "Intel MPX (Memory Protection Extensions)"
1704 def_bool n
1705 depends on CPU_SUP_INTEL
1706 ---help---
1707 MPX provides hardware features that can be used in
1708 conjunction with compiler-instrumented code to check
1709 memory references. It is designed to detect buffer
1710 overflow or underflow bugs.
1711
1712 This option enables running applications which are
1713 instrumented or otherwise use MPX. It does not use MPX
1714 itself inside the kernel or to protect the kernel
1715 against bad memory references.
1716
1717 Enabling this option will make the kernel larger:
1718 ~8k of kernel text and 36 bytes of data on a 64-bit
1719 defconfig. It adds a long to the 'mm_struct' which
1720 will increase the kernel memory overhead of each
1721 process and adds some branches to paths used during
1722 exec() and munmap().
1723
1724 For details, see Documentation/x86/intel_mpx.txt
1725
1726 If unsure, say N.
1727
506f1d07 1728config EFI
9ba16087 1729 bool "EFI runtime service support"
5b83683f 1730 depends on ACPI
f6ce5002 1731 select UCS2_STRING
022ee6c5 1732 select EFI_RUNTIME_WRAPPERS
506f1d07 1733 ---help---
8f9ca475
IM
1734 This enables the kernel to use EFI runtime services that are
1735 available (such as the EFI variable services).
506f1d07 1736
8f9ca475
IM
1737 This option is only useful on systems that have EFI firmware.
1738 In addition, you should use the latest ELILO loader available
1739 at <http://elilo.sourceforge.net> in order to take advantage
1740 of EFI runtime services. However, even with this option, the
1741 resultant kernel should continue to boot on existing non-EFI
1742 platforms.
506f1d07 1743
291f3632
MF
1744config EFI_STUB
1745 bool "EFI stub support"
b16d8c23 1746 depends on EFI && !X86_USE_3DNOW
7b2a583a 1747 select RELOCATABLE
291f3632
MF
1748 ---help---
1749 This kernel feature allows a bzImage to be loaded directly
1750 by EFI firmware without the use of a bootloader.
1751
4172fe2f 1752 See Documentation/efi-stub.txt for more information.
0c759662 1753
7d453eee
MF
1754config EFI_MIXED
1755 bool "EFI mixed-mode support"
1756 depends on EFI_STUB && X86_64
1757 ---help---
1758 Enabling this feature allows a 64-bit kernel to be booted
1759 on a 32-bit firmware, provided that your CPU supports 64-bit
1760 mode.
1761
1762 Note that it is not possible to boot a mixed-mode enabled
1763 kernel via the EFI boot stub - a bootloader that supports
1764 the EFI handover protocol must be used.
1765
1766 If unsure, say N.
1767
506f1d07 1768config SECCOMP
3c2362e6
HH
1769 def_bool y
1770 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1771 ---help---
506f1d07
SR
1772 This kernel feature is useful for number crunching applications
1773 that may need to compute untrusted bytecode during their
1774 execution. By using pipes or other transports made available to
1775 the process as file descriptors supporting the read/write
1776 syscalls, it's possible to isolate those applications in
1777 their own address space using seccomp. Once seccomp is
9c0bbee8 1778 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1779 and the task is only allowed to execute a few safe syscalls
1780 defined by each seccomp mode.
1781
1782 If unsure, say Y. Only embedded should say N here.
1783
506f1d07
SR
1784source kernel/Kconfig.hz
1785
1786config KEXEC
1787 bool "kexec system call"
2965faa5 1788 select KEXEC_CORE
8f9ca475 1789 ---help---
506f1d07
SR
1790 kexec is a system call that implements the ability to shutdown your
1791 current kernel, and to start another kernel. It is like a reboot
1792 but it is independent of the system firmware. And like a reboot
1793 you can start any kernel with it, not just Linux.
1794
1795 The name comes from the similarity to the exec system call.
1796
1797 It is an ongoing process to be certain the hardware in a machine
1798 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1799 initially work for you. As of this writing the exact hardware
1800 interface is strongly in flux, so no good recommendation can be
1801 made.
506f1d07 1802
74ca317c
VG
1803config KEXEC_FILE
1804 bool "kexec file based system call"
2965faa5 1805 select KEXEC_CORE
74ca317c 1806 select BUILD_BIN2C
74ca317c
VG
1807 depends on X86_64
1808 depends on CRYPTO=y
1809 depends on CRYPTO_SHA256=y
1810 ---help---
1811 This is new version of kexec system call. This system call is
1812 file based and takes file descriptors as system call argument
1813 for kernel and initramfs as opposed to list of segments as
1814 accepted by previous system call.
1815
8e7d8381
VG
1816config KEXEC_VERIFY_SIG
1817 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1818 depends on KEXEC_FILE
8e7d8381
VG
1819 ---help---
1820 This option makes kernel signature verification mandatory for
d8eb8940
BP
1821 the kexec_file_load() syscall.
1822
1823 In addition to that option, you need to enable signature
1824 verification for the corresponding kernel image type being
1825 loaded in order for this to work.
8e7d8381
VG
1826
1827config KEXEC_BZIMAGE_VERIFY_SIG
1828 bool "Enable bzImage signature verification support"
1829 depends on KEXEC_VERIFY_SIG
1830 depends on SIGNED_PE_FILE_VERIFICATION
1831 select SYSTEM_TRUSTED_KEYRING
1832 ---help---
1833 Enable bzImage signature verification support.
1834
506f1d07 1835config CRASH_DUMP
04b69447 1836 bool "kernel crash dumps"
506f1d07 1837 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1838 ---help---
506f1d07
SR
1839 Generate crash dump after being started by kexec.
1840 This should be normally only set in special crash dump kernels
1841 which are loaded in the main kernel with kexec-tools into
1842 a specially reserved region and then later executed after
1843 a crash by kdump/kexec. The crash dump kernel must be compiled
1844 to a memory address not used by the main kernel or BIOS using
1845 PHYSICAL_START, or it must be built as a relocatable image
1846 (CONFIG_RELOCATABLE=y).
1847 For more details see Documentation/kdump/kdump.txt
1848
3ab83521 1849config KEXEC_JUMP
6ea30386 1850 bool "kexec jump"
fee7b0d8 1851 depends on KEXEC && HIBERNATION
8f9ca475 1852 ---help---
89081d17
HY
1853 Jump between original kernel and kexeced kernel and invoke
1854 code in physical address mode via KEXEC
3ab83521 1855
506f1d07 1856config PHYSICAL_START
6a108a14 1857 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 1858 default "0x1000000"
8f9ca475 1859 ---help---
506f1d07
SR
1860 This gives the physical address where the kernel is loaded.
1861
1862 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1863 bzImage will decompress itself to above physical address and
1864 run from there. Otherwise, bzImage will run from the address where
1865 it has been loaded by the boot loader and will ignore above physical
1866 address.
1867
1868 In normal kdump cases one does not have to set/change this option
1869 as now bzImage can be compiled as a completely relocatable image
1870 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1871 address. This option is mainly useful for the folks who don't want
1872 to use a bzImage for capturing the crash dump and want to use a
1873 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1874 to be specifically compiled to run from a specific memory area
1875 (normally a reserved region) and this option comes handy.
1876
ceefccc9
PA
1877 So if you are using bzImage for capturing the crash dump,
1878 leave the value here unchanged to 0x1000000 and set
1879 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1880 for capturing the crash dump change this value to start of
1881 the reserved region. In other words, it can be set based on
1882 the "X" value as specified in the "crashkernel=YM@XM"
1883 command line boot parameter passed to the panic-ed
1884 kernel. Please take a look at Documentation/kdump/kdump.txt
1885 for more details about crash dumps.
506f1d07
SR
1886
1887 Usage of bzImage for capturing the crash dump is recommended as
1888 one does not have to build two kernels. Same kernel can be used
1889 as production kernel and capture kernel. Above option should have
1890 gone away after relocatable bzImage support is introduced. But it
1891 is present because there are users out there who continue to use
1892 vmlinux for dump capture. This option should go away down the
1893 line.
1894
1895 Don't change this unless you know what you are doing.
1896
1897config RELOCATABLE
26717808
PA
1898 bool "Build a relocatable kernel"
1899 default y
8f9ca475 1900 ---help---
506f1d07
SR
1901 This builds a kernel image that retains relocation information
1902 so it can be loaded someplace besides the default 1MB.
1903 The relocations tend to make the kernel binary about 10% larger,
1904 but are discarded at runtime.
1905
1906 One use is for the kexec on panic case where the recovery kernel
1907 must live at a different physical address than the primary
1908 kernel.
1909
1910 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1911 it has been loaded at and the compile time physical address
8ab3820f 1912 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 1913
8ab3820f
KC
1914config RANDOMIZE_BASE
1915 bool "Randomize the address of the kernel image"
1916 depends on RELOCATABLE
8ab3820f
KC
1917 default n
1918 ---help---
1919 Randomizes the physical and virtual address at which the
1920 kernel image is decompressed, as a security feature that
1921 deters exploit attempts relying on knowledge of the location
1922 of kernel internals.
1923
a653f356
KC
1924 Entropy is generated using the RDRAND instruction if it is
1925 supported. If RDTSC is supported, it is used as well. If
1926 neither RDRAND nor RDTSC are supported, then randomness is
1927 read from the i8254 timer.
8ab3820f
KC
1928
1929 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
a653f356
KC
1930 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1931 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1932 minimum of 2MiB, only 10 bits of entropy is theoretically
1933 possible. At best, due to page table layouts, 64-bit can use
1934 9 bits of entropy and 32-bit uses 8 bits.
8ab3820f 1935
da2b6fb9
KC
1936 If unsure, say N.
1937
8ab3820f 1938config RANDOMIZE_BASE_MAX_OFFSET
da2b6fb9 1939 hex "Maximum kASLR offset allowed" if EXPERT
8ab3820f 1940 depends on RANDOMIZE_BASE
6145cfe3
KC
1941 range 0x0 0x20000000 if X86_32
1942 default "0x20000000" if X86_32
1943 range 0x0 0x40000000 if X86_64
1944 default "0x40000000" if X86_64
8ab3820f 1945 ---help---
da2b6fb9
KC
1946 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1947 memory is used to determine the maximal offset in bytes that will
1948 be applied to the kernel when kernel Address Space Layout
1949 Randomization (kASLR) is active. This must be a multiple of
1950 PHYSICAL_ALIGN.
1951
1952 On 32-bit this is limited to 512MiB by page table layouts. The
1953 default is 512MiB.
6145cfe3 1954
da2b6fb9
KC
1955 On 64-bit this is limited by how the kernel fixmap page table is
1956 positioned, so this cannot be larger than 1GiB currently. Without
1957 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1958 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1959 modules area will shrink to compensate, up to the current maximum
1960 1GiB to 1GiB split. The default is 1GiB.
6145cfe3 1961
da2b6fb9 1962 If unsure, leave at the default value.
8ab3820f
KC
1963
1964# Relocation on x86 needs some additional build support
845adf72
PA
1965config X86_NEED_RELOCS
1966 def_bool y
8ab3820f 1967 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 1968
506f1d07 1969config PHYSICAL_ALIGN
a0215061 1970 hex "Alignment value to which kernel should be aligned"
8ab3820f 1971 default "0x200000"
a0215061
KC
1972 range 0x2000 0x1000000 if X86_32
1973 range 0x200000 0x1000000 if X86_64
8f9ca475 1974 ---help---
506f1d07
SR
1975 This value puts the alignment restrictions on physical address
1976 where kernel is loaded and run from. Kernel is compiled for an
1977 address which meets above alignment restriction.
1978
1979 If bootloader loads the kernel at a non-aligned address and
1980 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1981 address aligned to above value and run from there.
1982
1983 If bootloader loads the kernel at a non-aligned address and
1984 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1985 load address and decompress itself to the address it has been
1986 compiled for and run from there. The address for which kernel is
1987 compiled already meets above alignment restrictions. Hence the
1988 end result is that kernel runs from a physical address meeting
1989 above alignment restrictions.
1990
a0215061
KC
1991 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1992 this value must be a multiple of 0x200000.
1993
506f1d07
SR
1994 Don't change this unless you know what you are doing.
1995
1996config HOTPLUG_CPU
7c13e6a3 1997 bool "Support for hot-pluggable CPUs"
40b31360 1998 depends on SMP
506f1d07 1999 ---help---
7c13e6a3
DS
2000 Say Y here to allow turning CPUs off and on. CPUs can be
2001 controlled through /sys/devices/system/cpu.
2002 ( Note: power management support will enable this option
2003 automatically on SMP systems. )
2004 Say N if you want to disable CPU hotplug.
506f1d07 2005
80aa1dff
FY
2006config BOOTPARAM_HOTPLUG_CPU0
2007 bool "Set default setting of cpu0_hotpluggable"
2008 default n
2c922cd0 2009 depends on HOTPLUG_CPU
80aa1dff
FY
2010 ---help---
2011 Set whether default state of cpu0_hotpluggable is on or off.
2012
2013 Say Y here to enable CPU0 hotplug by default. If this switch
2014 is turned on, there is no need to give cpu0_hotplug kernel
2015 parameter and the CPU0 hotplug feature is enabled by default.
2016
2017 Please note: there are two known CPU0 dependencies if you want
2018 to enable the CPU0 hotplug feature either by this switch or by
2019 cpu0_hotplug kernel parameter.
2020
2021 First, resume from hibernate or suspend always starts from CPU0.
2022 So hibernate and suspend are prevented if CPU0 is offline.
2023
2024 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2025 offline if any interrupt can not migrate out of CPU0. There may
2026 be other CPU0 dependencies.
2027
2028 Please make sure the dependencies are under your control before
2029 you enable this feature.
2030
2031 Say N if you don't want to enable CPU0 hotplug feature by default.
2032 You still can enable the CPU0 hotplug feature at boot by kernel
2033 parameter cpu0_hotplug.
2034
a71c8bc5
FY
2035config DEBUG_HOTPLUG_CPU0
2036 def_bool n
2037 prompt "Debug CPU0 hotplug"
2c922cd0 2038 depends on HOTPLUG_CPU
a71c8bc5
FY
2039 ---help---
2040 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2041 soon as possible and boots up userspace with CPU0 offlined. User
2042 can online CPU0 back after boot time.
2043
2044 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2045 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2046 compilation or giving cpu0_hotplug kernel parameter at boot.
2047
2048 If unsure, say N.
2049
506f1d07 2050config COMPAT_VDSO
b0b49f26
AL
2051 def_bool n
2052 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
af65d648 2053 depends on X86_32 || IA32_EMULATION
8f9ca475 2054 ---help---
b0b49f26
AL
2055 Certain buggy versions of glibc will crash if they are
2056 presented with a 32-bit vDSO that is not mapped at the address
2057 indicated in its segment table.
e84446de 2058
b0b49f26
AL
2059 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2060 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2061 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2062 the only released version with the bug, but OpenSUSE 9
2063 contains a buggy "glibc 2.3.2".
506f1d07 2064
b0b49f26
AL
2065 The symptom of the bug is that everything crashes on startup, saying:
2066 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2067
2068 Saying Y here changes the default value of the vdso32 boot
2069 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2070 This works around the glibc bug but hurts performance.
2071
2072 If unsure, say N: if you are compiling your own kernel, you
2073 are unlikely to be using a buggy version of glibc.
506f1d07 2074
3dc33bd3
KC
2075choice
2076 prompt "vsyscall table for legacy applications"
2077 depends on X86_64
2078 default LEGACY_VSYSCALL_EMULATE
2079 help
2080 Legacy user code that does not know how to find the vDSO expects
2081 to be able to issue three syscalls by calling fixed addresses in
2082 kernel space. Since this location is not randomized with ASLR,
2083 it can be used to assist security vulnerability exploitation.
2084
2085 This setting can be changed at boot time via the kernel command
2086 line parameter vsyscall=[native|emulate|none].
2087
2088 On a system with recent enough glibc (2.14 or newer) and no
2089 static binaries, you can say None without a performance penalty
2090 to improve security.
2091
2092 If unsure, select "Emulate".
2093
2094 config LEGACY_VSYSCALL_NATIVE
2095 bool "Native"
2096 help
2097 Actual executable code is located in the fixed vsyscall
2098 address mapping, implementing time() efficiently. Since
2099 this makes the mapping executable, it can be used during
2100 security vulnerability exploitation (traditionally as
2101 ROP gadgets). This configuration is not recommended.
2102
2103 config LEGACY_VSYSCALL_EMULATE
2104 bool "Emulate"
2105 help
2106 The kernel traps and emulates calls into the fixed
2107 vsyscall address mapping. This makes the mapping
2108 non-executable, but it still contains known contents,
2109 which could be used in certain rare security vulnerability
2110 exploits. This configuration is recommended when userspace
2111 still uses the vsyscall area.
2112
2113 config LEGACY_VSYSCALL_NONE
2114 bool "None"
2115 help
2116 There will be no vsyscall mapping at all. This will
2117 eliminate any risk of ASLR bypass due to the vsyscall
2118 fixed address mapping. Attempts to use the vsyscalls
2119 will be reported to dmesg, so that either old or
2120 malicious userspace programs can be identified.
2121
2122endchoice
2123
516cbf37
TB
2124config CMDLINE_BOOL
2125 bool "Built-in kernel command line"
8f9ca475 2126 ---help---
516cbf37
TB
2127 Allow for specifying boot arguments to the kernel at
2128 build time. On some systems (e.g. embedded ones), it is
2129 necessary or convenient to provide some or all of the
2130 kernel boot arguments with the kernel itself (that is,
2131 to not rely on the boot loader to provide them.)
2132
2133 To compile command line arguments into the kernel,
2134 set this option to 'Y', then fill in the
69711ca1 2135 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2136
2137 Systems with fully functional boot loaders (i.e. non-embedded)
2138 should leave this option set to 'N'.
2139
2140config CMDLINE
2141 string "Built-in kernel command string"
2142 depends on CMDLINE_BOOL
2143 default ""
8f9ca475 2144 ---help---
516cbf37
TB
2145 Enter arguments here that should be compiled into the kernel
2146 image and used at boot time. If the boot loader provides a
2147 command line at boot time, it is appended to this string to
2148 form the full kernel command line, when the system boots.
2149
2150 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2151 change this behavior.
2152
2153 In most cases, the command line (whether built-in or provided
2154 by the boot loader) should specify the device for the root
2155 file system.
2156
2157config CMDLINE_OVERRIDE
2158 bool "Built-in command line overrides boot loader arguments"
516cbf37 2159 depends on CMDLINE_BOOL
8f9ca475 2160 ---help---
516cbf37
TB
2161 Set this option to 'Y' to have the kernel ignore the boot loader
2162 command line, and use ONLY the built-in command line.
2163
2164 This is used to work around broken boot loaders. This should
2165 be set to 'N' under normal conditions.
2166
a5b9e5a2
AL
2167config MODIFY_LDT_SYSCALL
2168 bool "Enable the LDT (local descriptor table)" if EXPERT
2169 default y
2170 ---help---
2171 Linux can allow user programs to install a per-process x86
2172 Local Descriptor Table (LDT) using the modify_ldt(2) system
2173 call. This is required to run 16-bit or segmented code such as
2174 DOSEMU or some Wine programs. It is also used by some very old
2175 threading libraries.
2176
2177 Enabling this feature adds a small amount of overhead to
2178 context switches and increases the low-level kernel attack
2179 surface. Disabling it removes the modify_ldt(2) system call.
2180
2181 Saying 'N' here may make sense for embedded or server kernels.
2182
b700e7f0
SJ
2183source "kernel/livepatch/Kconfig"
2184
506f1d07
SR
2185endmenu
2186
2187config ARCH_ENABLE_MEMORY_HOTPLUG
2188 def_bool y
2189 depends on X86_64 || (X86_32 && HIGHMEM)
2190
35551053
GH
2191config ARCH_ENABLE_MEMORY_HOTREMOVE
2192 def_bool y
2193 depends on MEMORY_HOTPLUG
2194
e534c7c5 2195config USE_PERCPU_NUMA_NODE_ID
645a7919 2196 def_bool y
e534c7c5
LS
2197 depends on NUMA
2198
9491846f
KS
2199config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2200 def_bool y
2201 depends on X86_64 || X86_PAE
2202
c177c81e
NH
2203config ARCH_ENABLE_HUGEPAGE_MIGRATION
2204 def_bool y
2205 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2206
da85f865 2207menu "Power management and ACPI options"
e279b6c1
SR
2208
2209config ARCH_HIBERNATION_HEADER
3c2362e6 2210 def_bool y
e279b6c1 2211 depends on X86_64 && HIBERNATION
e279b6c1
SR
2212
2213source "kernel/power/Kconfig"
2214
2215source "drivers/acpi/Kconfig"
2216
efafc8b2
FT
2217source "drivers/sfi/Kconfig"
2218
a6b68076 2219config X86_APM_BOOT
6fc108a0 2220 def_bool y
282e5aab 2221 depends on APM
a6b68076 2222
e279b6c1
SR
2223menuconfig APM
2224 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2225 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2226 ---help---
2227 APM is a BIOS specification for saving power using several different
2228 techniques. This is mostly useful for battery powered laptops with
2229 APM compliant BIOSes. If you say Y here, the system time will be
2230 reset after a RESUME operation, the /proc/apm device will provide
2231 battery status information, and user-space programs will receive
2232 notification of APM "events" (e.g. battery status change).
2233
2234 If you select "Y" here, you can disable actual use of the APM
2235 BIOS by passing the "apm=off" option to the kernel at boot time.
2236
2237 Note that the APM support is almost completely disabled for
2238 machines with more than one CPU.
2239
2240 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2241 and more information, read <file:Documentation/power/apm-acpi.txt>
2242 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2243 <http://www.tldp.org/docs.html#howto>.
2244
2245 This driver does not spin down disk drives (see the hdparm(8)
2246 manpage ("man 8 hdparm") for that), and it doesn't turn off
2247 VESA-compliant "green" monitors.
2248
2249 This driver does not support the TI 4000M TravelMate and the ACER
2250 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2251 desktop machines also don't have compliant BIOSes, and this driver
2252 may cause those machines to panic during the boot phase.
2253
2254 Generally, if you don't have a battery in your machine, there isn't
2255 much point in using this driver and you should say N. If you get
2256 random kernel OOPSes or reboots that don't seem to be related to
2257 anything, try disabling/enabling this option (or disabling/enabling
2258 APM in your BIOS).
2259
2260 Some other things you should try when experiencing seemingly random,
2261 "weird" problems:
2262
2263 1) make sure that you have enough swap space and that it is
2264 enabled.
2265 2) pass the "no-hlt" option to the kernel
2266 3) switch on floating point emulation in the kernel and pass
2267 the "no387" option to the kernel
2268 4) pass the "floppy=nodma" option to the kernel
2269 5) pass the "mem=4M" option to the kernel (thereby disabling
2270 all but the first 4 MB of RAM)
2271 6) make sure that the CPU is not over clocked.
2272 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2273 8) disable the cache from your BIOS settings
2274 9) install a fan for the video card or exchange video RAM
2275 10) install a better fan for the CPU
2276 11) exchange RAM chips
2277 12) exchange the motherboard.
2278
2279 To compile this driver as a module, choose M here: the
2280 module will be called apm.
2281
2282if APM
2283
2284config APM_IGNORE_USER_SUSPEND
2285 bool "Ignore USER SUSPEND"
8f9ca475 2286 ---help---
e279b6c1
SR
2287 This option will ignore USER SUSPEND requests. On machines with a
2288 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2289 series notebooks, it is necessary to say Y because of a BIOS bug.
2290
2291config APM_DO_ENABLE
2292 bool "Enable PM at boot time"
2293 ---help---
2294 Enable APM features at boot time. From page 36 of the APM BIOS
2295 specification: "When disabled, the APM BIOS does not automatically
2296 power manage devices, enter the Standby State, enter the Suspend
2297 State, or take power saving steps in response to CPU Idle calls."
2298 This driver will make CPU Idle calls when Linux is idle (unless this
2299 feature is turned off -- see "Do CPU IDLE calls", below). This
2300 should always save battery power, but more complicated APM features
2301 will be dependent on your BIOS implementation. You may need to turn
2302 this option off if your computer hangs at boot time when using APM
2303 support, or if it beeps continuously instead of suspending. Turn
2304 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2305 T400CDT. This is off by default since most machines do fine without
2306 this feature.
2307
2308config APM_CPU_IDLE
dd8af076 2309 depends on CPU_IDLE
e279b6c1 2310 bool "Make CPU Idle calls when idle"
8f9ca475 2311 ---help---
e279b6c1
SR
2312 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2313 On some machines, this can activate improved power savings, such as
2314 a slowed CPU clock rate, when the machine is idle. These idle calls
2315 are made after the idle loop has run for some length of time (e.g.,
2316 333 mS). On some machines, this will cause a hang at boot time or
2317 whenever the CPU becomes idle. (On machines with more than one CPU,
2318 this option does nothing.)
2319
2320config APM_DISPLAY_BLANK
2321 bool "Enable console blanking using APM"
8f9ca475 2322 ---help---
e279b6c1
SR
2323 Enable console blanking using the APM. Some laptops can use this to
2324 turn off the LCD backlight when the screen blanker of the Linux
2325 virtual console blanks the screen. Note that this is only used by
2326 the virtual console screen blanker, and won't turn off the backlight
2327 when using the X Window system. This also doesn't have anything to
2328 do with your VESA-compliant power-saving monitor. Further, this
2329 option doesn't work for all laptops -- it might not turn off your
2330 backlight at all, or it might print a lot of errors to the console,
2331 especially if you are using gpm.
2332
2333config APM_ALLOW_INTS
2334 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2335 ---help---
e279b6c1
SR
2336 Normally we disable external interrupts while we are making calls to
2337 the APM BIOS as a measure to lessen the effects of a badly behaving
2338 BIOS implementation. The BIOS should reenable interrupts if it
2339 needs to. Unfortunately, some BIOSes do not -- especially those in
2340 many of the newer IBM Thinkpads. If you experience hangs when you
2341 suspend, try setting this to Y. Otherwise, say N.
2342
e279b6c1
SR
2343endif # APM
2344
bb0a56ec 2345source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2346
2347source "drivers/cpuidle/Kconfig"
2348
27471fdb
AH
2349source "drivers/idle/Kconfig"
2350
e279b6c1
SR
2351endmenu
2352
2353
2354menu "Bus options (PCI etc.)"
2355
2356config PCI
1ac97018 2357 bool "PCI support"
1c858087 2358 default y
8f9ca475 2359 ---help---
e279b6c1
SR
2360 Find out whether you have a PCI motherboard. PCI is the name of a
2361 bus system, i.e. the way the CPU talks to the other stuff inside
2362 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2363 VESA. If you have PCI, say Y, otherwise N.
2364
e279b6c1
SR
2365choice
2366 prompt "PCI access mode"
efefa6f6 2367 depends on X86_32 && PCI
e279b6c1
SR
2368 default PCI_GOANY
2369 ---help---
2370 On PCI systems, the BIOS can be used to detect the PCI devices and
2371 determine their configuration. However, some old PCI motherboards
2372 have BIOS bugs and may crash if this is done. Also, some embedded
2373 PCI-based systems don't have any BIOS at all. Linux can also try to
2374 detect the PCI hardware directly without using the BIOS.
2375
2376 With this option, you can specify how Linux should detect the
2377 PCI devices. If you choose "BIOS", the BIOS will be used,
2378 if you choose "Direct", the BIOS won't be used, and if you
2379 choose "MMConfig", then PCI Express MMCONFIG will be used.
2380 If you choose "Any", the kernel will try MMCONFIG, then the
2381 direct access method and falls back to the BIOS if that doesn't
2382 work. If unsure, go with the default, which is "Any".
2383
2384config PCI_GOBIOS
2385 bool "BIOS"
2386
2387config PCI_GOMMCONFIG
2388 bool "MMConfig"
2389
2390config PCI_GODIRECT
2391 bool "Direct"
2392
3ef0e1f8 2393config PCI_GOOLPC
76fb6570 2394 bool "OLPC XO-1"
3ef0e1f8
AS
2395 depends on OLPC
2396
2bdd1b03
AS
2397config PCI_GOANY
2398 bool "Any"
2399
e279b6c1
SR
2400endchoice
2401
2402config PCI_BIOS
3c2362e6 2403 def_bool y
efefa6f6 2404 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2405
2406# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2407config PCI_DIRECT
3c2362e6 2408 def_bool y
0aba496f 2409 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2410
2411config PCI_MMCONFIG
3c2362e6 2412 def_bool y
5f0db7a2 2413 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2414
3ef0e1f8 2415config PCI_OLPC
2bdd1b03
AS
2416 def_bool y
2417 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2418
b5401a96
AN
2419config PCI_XEN
2420 def_bool y
2421 depends on PCI && XEN
2422 select SWIOTLB_XEN
2423
e279b6c1 2424config PCI_DOMAINS
3c2362e6 2425 def_bool y
e279b6c1 2426 depends on PCI
e279b6c1
SR
2427
2428config PCI_MMCONFIG
2429 bool "Support mmconfig PCI config space access"
2430 depends on X86_64 && PCI && ACPI
2431
3f6ea84a 2432config PCI_CNB20LE_QUIRK
6a108a14 2433 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2434 depends on PCI
3f6ea84a
IS
2435 help
2436 Read the PCI windows out of the CNB20LE host bridge. This allows
2437 PCI hotplug to work on systems with the CNB20LE chipset which do
2438 not have ACPI.
2439
64a5fed6
BH
2440 There's no public spec for this chipset, and this functionality
2441 is known to be incomplete.
2442
2443 You should say N unless you know you need this.
2444
e279b6c1
SR
2445source "drivers/pci/pcie/Kconfig"
2446
2447source "drivers/pci/Kconfig"
2448
1c00f016 2449# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2450config ISA_DMA_API
1c00f016
DR
2451 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2452 default y
2453 help
2454 Enables ISA-style DMA support for devices requiring such controllers.
2455 If unsure, say Y.
e279b6c1
SR
2456
2457if X86_32
2458
2459config ISA
2460 bool "ISA support"
8f9ca475 2461 ---help---
e279b6c1
SR
2462 Find out whether you have ISA slots on your motherboard. ISA is the
2463 name of a bus system, i.e. the way the CPU talks to the other stuff
2464 inside your box. Other bus systems are PCI, EISA, MicroChannel
2465 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2466 newer boards don't support it. If you have ISA, say Y, otherwise N.
2467
2468config EISA
2469 bool "EISA support"
2470 depends on ISA
2471 ---help---
2472 The Extended Industry Standard Architecture (EISA) bus was
2473 developed as an open alternative to the IBM MicroChannel bus.
2474
2475 The EISA bus provided some of the features of the IBM MicroChannel
2476 bus while maintaining backward compatibility with cards made for
2477 the older ISA bus. The EISA bus saw limited use between 1988 and
2478 1995 when it was made obsolete by the PCI bus.
2479
2480 Say Y here if you are building a kernel for an EISA-based machine.
2481
2482 Otherwise, say N.
2483
2484source "drivers/eisa/Kconfig"
2485
e279b6c1
SR
2486config SCx200
2487 tristate "NatSemi SCx200 support"
8f9ca475 2488 ---help---
e279b6c1
SR
2489 This provides basic support for National Semiconductor's
2490 (now AMD's) Geode processors. The driver probes for the
2491 PCI-IDs of several on-chip devices, so its a good dependency
2492 for other scx200_* drivers.
2493
2494 If compiled as a module, the driver is named scx200.
2495
2496config SCx200HR_TIMER
2497 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2498 depends on SCx200
e279b6c1 2499 default y
8f9ca475 2500 ---help---
e279b6c1
SR
2501 This driver provides a clocksource built upon the on-chip
2502 27MHz high-resolution timer. Its also a workaround for
2503 NSC Geode SC-1100's buggy TSC, which loses time when the
2504 processor goes idle (as is done by the scheduler). The
2505 other workaround is idle=poll boot option.
2506
3ef0e1f8
AS
2507config OLPC
2508 bool "One Laptop Per Child support"
54008979 2509 depends on !X86_PAE
3c554946 2510 select GPIOLIB
dc3119e7 2511 select OF
45bb1674 2512 select OF_PROMTREE
b4e51854 2513 select IRQ_DOMAIN
8f9ca475 2514 ---help---
3ef0e1f8
AS
2515 Add support for detecting the unique features of the OLPC
2516 XO hardware.
2517
a3128588
DD
2518config OLPC_XO1_PM
2519 bool "OLPC XO-1 Power Management"
97c4cb71 2520 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2521 select MFD_CORE
bf1ebf00 2522 ---help---
97c4cb71 2523 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2524
cfee9597
DD
2525config OLPC_XO1_RTC
2526 bool "OLPC XO-1 Real Time Clock"
2527 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2528 ---help---
2529 Add support for the XO-1 real time clock, which can be used as a
2530 programmable wakeup source.
2531
7feda8e9
DD
2532config OLPC_XO1_SCI
2533 bool "OLPC XO-1 SCI extras"
d8d01a63 2534 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2535 depends on INPUT=y
d8d01a63 2536 select POWER_SUPPLY
7feda8e9
DD
2537 select GPIO_CS5535
2538 select MFD_CORE
2539 ---help---
2540 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2541 - EC-driven system wakeups
7feda8e9 2542 - Power button
7bc74b3d 2543 - Ebook switch
2cf2baea 2544 - Lid switch
e1040ac6
DD
2545 - AC adapter status updates
2546 - Battery status updates
7feda8e9 2547
a0f30f59
DD
2548config OLPC_XO15_SCI
2549 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2550 depends on OLPC && ACPI
2551 select POWER_SUPPLY
a0f30f59
DD
2552 ---help---
2553 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2554 - EC-driven system wakeups
2555 - AC adapter status updates
2556 - Battery status updates
bf1ebf00 2557
d4f3e350
EW
2558config ALIX
2559 bool "PCEngines ALIX System Support (LED setup)"
2560 select GPIOLIB
2561 ---help---
2562 This option enables system support for the PCEngines ALIX.
2563 At present this just sets up LEDs for GPIO control on
2564 ALIX2/3/6 boards. However, other system specific setup should
2565 get added here.
2566
2567 Note: You must still enable the drivers for GPIO and LED support
2568 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2569
2570 Note: You have to set alix.force=1 for boards with Award BIOS.
2571
da4e3302
PP
2572config NET5501
2573 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2574 select GPIOLIB
2575 ---help---
2576 This option enables system support for the Soekris Engineering net5501.
2577
3197059a
PP
2578config GEOS
2579 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2580 select GPIOLIB
2581 depends on DMI
2582 ---help---
2583 This option enables system support for the Traverse Technologies GEOS.
2584
7d029125
VD
2585config TS5500
2586 bool "Technologic Systems TS-5500 platform support"
2587 depends on MELAN
2588 select CHECK_SIGNATURE
2589 select NEW_LEDS
2590 select LEDS_CLASS
2591 ---help---
2592 This option enables system support for the Technologic Systems TS-5500.
2593
bc0120fd
SR
2594endif # X86_32
2595
23ac4ae8 2596config AMD_NB
e279b6c1 2597 def_bool y
0e152cd7 2598 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2599
2600source "drivers/pcmcia/Kconfig"
2601
2602source "drivers/pci/hotplug/Kconfig"
2603
388b78ad 2604config RAPIDIO
fdf90abc 2605 tristate "RapidIO support"
388b78ad
AB
2606 depends on PCI
2607 default n
2608 help
fdf90abc 2609 If enabled this option will include drivers and the core
388b78ad
AB
2610 infrastructure code to support RapidIO interconnect devices.
2611
2612source "drivers/rapidio/Kconfig"
2613
e3263ab3
DR
2614config X86_SYSFB
2615 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2616 help
2617 Firmwares often provide initial graphics framebuffers so the BIOS,
2618 bootloader or kernel can show basic video-output during boot for
2619 user-guidance and debugging. Historically, x86 used the VESA BIOS
2620 Extensions and EFI-framebuffers for this, which are mostly limited
2621 to x86.
2622 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2623 framebuffers so the new generic system-framebuffer drivers can be
2624 used on x86. If the framebuffer is not compatible with the generic
2625 modes, it is adverticed as fallback platform framebuffer so legacy
2626 drivers like efifb, vesafb and uvesafb can pick it up.
2627 If this option is not selected, all system framebuffers are always
2628 marked as fallback platform framebuffers as usual.
2629
2630 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2631 not be able to pick up generic system framebuffers if this option
2632 is selected. You are highly encouraged to enable simplefb as
2633 replacement if you select this option. simplefb can correctly deal
2634 with generic system framebuffers. But you should still keep vesafb
2635 and others enabled as fallback if a system framebuffer is
2636 incompatible with simplefb.
2637
2638 If unsure, say Y.
2639
e279b6c1
SR
2640endmenu
2641
2642
2643menu "Executable file formats / Emulations"
2644
2645source "fs/Kconfig.binfmt"
2646
2647config IA32_EMULATION
2648 bool "IA32 Emulation"
2649 depends on X86_64
d1603990 2650 select BINFMT_ELF
a97f52e6 2651 select COMPAT_BINFMT_ELF
3bead553 2652 select ARCH_WANT_OLD_COMPAT_IPC
8f9ca475 2653 ---help---
5fd92e65
L
2654 Include code to run legacy 32-bit programs under a
2655 64-bit kernel. You should likely turn this on, unless you're
2656 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2657
2658config IA32_AOUT
8f9ca475
IM
2659 tristate "IA32 a.out support"
2660 depends on IA32_EMULATION
2661 ---help---
2662 Support old a.out binaries in the 32bit emulation.
e279b6c1 2663
0bf62763 2664config X86_X32
6ea30386 2665 bool "x32 ABI for 64-bit mode"
9b54050b 2666 depends on X86_64
5fd92e65
L
2667 ---help---
2668 Include code to run binaries for the x32 native 32-bit ABI
2669 for 64-bit processors. An x32 process gets access to the
2670 full 64-bit register file and wide data path while leaving
2671 pointers at 32 bits for smaller memory footprint.
2672
2673 You will need a recent binutils (2.22 or later) with
2674 elf32_x86_64 support enabled to compile a kernel with this
2675 option set.
2676
e279b6c1 2677config COMPAT
3c2362e6 2678 def_bool y
0bf62763 2679 depends on IA32_EMULATION || X86_X32
e279b6c1 2680
3120e25e 2681if COMPAT
e279b6c1 2682config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2683 def_bool y
e279b6c1
SR
2684
2685config SYSVIPC_COMPAT
3c2362e6 2686 def_bool y
3120e25e 2687 depends on SYSVIPC
e279b6c1 2688
ee009e4a 2689config KEYS_COMPAT
3120e25e
JB
2690 def_bool y
2691 depends on KEYS
2692endif
ee009e4a 2693
e279b6c1
SR
2694endmenu
2695
2696
e5beae16
KP
2697config HAVE_ATOMIC_IOMAP
2698 def_bool y
2699 depends on X86_32
2700
4692d77f
AR
2701config X86_DEV_DMA_OPS
2702 bool
83125a3a 2703 depends on X86_64 || STA2X11
4692d77f 2704
f7219a53
AR
2705config X86_DMA_REMAP
2706 bool
83125a3a 2707 depends on STA2X11
f7219a53 2708
93e5eadd
LA
2709config PMC_ATOM
2710 def_bool y
2711 depends on PCI
2712
185a383a
KB
2713config VMD
2714 depends on PCI_MSI
2715 tristate "Volume Management Device Driver"
2716 default N
2717 ---help---
2718 Adds support for the Intel Volume Management Device (VMD). VMD is a
2719 secondary PCI host bridge that allows PCI Express root ports,
2720 and devices attached to them, to be removed from the default
2721 PCI domain and placed within the VMD domain. This provides
2722 more bus resources than are otherwise possible with a
2723 single domain. If you know your system provides one of these and
2724 has devices attached to it, say Y; if you are not sure, say N.
2725
e279b6c1
SR
2726source "net/Kconfig"
2727
2728source "drivers/Kconfig"
2729
2730source "drivers/firmware/Kconfig"
2731
2732source "fs/Kconfig"
2733
e279b6c1
SR
2734source "arch/x86/Kconfig.debug"
2735
2736source "security/Kconfig"
2737
2738source "crypto/Kconfig"
2739
edf88417
AK
2740source "arch/x86/kvm/Kconfig"
2741
e279b6c1 2742source "lib/Kconfig"